1c50d8ae3SPaolo Bonzini // SPDX-License-Identifier: GPL-2.0-only 2c50d8ae3SPaolo Bonzini /* 3c50d8ae3SPaolo Bonzini * Kernel-based Virtual Machine driver for Linux 4c50d8ae3SPaolo Bonzini * 5c50d8ae3SPaolo Bonzini * This module enables machines with Intel VT-x extensions to run virtual 6c50d8ae3SPaolo Bonzini * machines without emulation or binary translation. 7c50d8ae3SPaolo Bonzini * 8c50d8ae3SPaolo Bonzini * MMU support 9c50d8ae3SPaolo Bonzini * 10c50d8ae3SPaolo Bonzini * Copyright (C) 2006 Qumranet, Inc. 11c50d8ae3SPaolo Bonzini * Copyright 2010 Red Hat, Inc. and/or its affiliates. 12c50d8ae3SPaolo Bonzini * 13c50d8ae3SPaolo Bonzini * Authors: 14c50d8ae3SPaolo Bonzini * Yaniv Kamay <yaniv@qumranet.com> 15c50d8ae3SPaolo Bonzini * Avi Kivity <avi@qumranet.com> 16c50d8ae3SPaolo Bonzini */ 178d20bd63SSean Christopherson #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18c50d8ae3SPaolo Bonzini 19c50d8ae3SPaolo Bonzini #include "irq.h" 2088197e6aS彭浩(Richard) #include "ioapic.h" 21c50d8ae3SPaolo Bonzini #include "mmu.h" 226ca9a6f3SSean Christopherson #include "mmu_internal.h" 23fe5db27dSBen Gardon #include "tdp_mmu.h" 24c50d8ae3SPaolo Bonzini #include "x86.h" 25c50d8ae3SPaolo Bonzini #include "kvm_cache_regs.h" 26b0b42197SPaolo Bonzini #include "smm.h" 272f728d66SSean Christopherson #include "kvm_emulate.h" 2858ea7cf7SSean Christopherson #include "page_track.h" 29c50d8ae3SPaolo Bonzini #include "cpuid.h" 305a9624afSPaolo Bonzini #include "spte.h" 31c50d8ae3SPaolo Bonzini 32c50d8ae3SPaolo Bonzini #include <linux/kvm_host.h> 33c50d8ae3SPaolo Bonzini #include <linux/types.h> 34c50d8ae3SPaolo Bonzini #include <linux/string.h> 35c50d8ae3SPaolo Bonzini #include <linux/mm.h> 36c50d8ae3SPaolo Bonzini #include <linux/highmem.h> 37c50d8ae3SPaolo Bonzini #include <linux/moduleparam.h> 38c50d8ae3SPaolo Bonzini #include <linux/export.h> 39c50d8ae3SPaolo Bonzini #include <linux/swap.h> 40c50d8ae3SPaolo Bonzini #include <linux/hugetlb.h> 41c50d8ae3SPaolo Bonzini #include <linux/compiler.h> 42c50d8ae3SPaolo Bonzini #include <linux/srcu.h> 43c50d8ae3SPaolo Bonzini #include <linux/slab.h> 44c50d8ae3SPaolo Bonzini #include <linux/sched/signal.h> 45c50d8ae3SPaolo Bonzini #include <linux/uaccess.h> 46c50d8ae3SPaolo Bonzini #include <linux/hash.h> 47c50d8ae3SPaolo Bonzini #include <linux/kern_levels.h> 4811b36fe7SChristophe JAILLET #include <linux/kstrtox.h> 49c50d8ae3SPaolo Bonzini #include <linux/kthread.h> 5066a5c40fSTanzir Hasan #include <linux/wordpart.h> 51c50d8ae3SPaolo Bonzini 52c50d8ae3SPaolo Bonzini #include <asm/page.h> 53eb243d1dSIngo Molnar #include <asm/memtype.h> 54c50d8ae3SPaolo Bonzini #include <asm/cmpxchg.h> 55c50d8ae3SPaolo Bonzini #include <asm/io.h> 564a98623dSSean Christopherson #include <asm/set_memory.h> 5765efc4dcSThomas Gleixner #include <asm/spec-ctrl.h> 58c50d8ae3SPaolo Bonzini #include <asm/vmx.h> 5958ea7cf7SSean Christopherson 60c50d8ae3SPaolo Bonzini #include "trace.h" 61c50d8ae3SPaolo Bonzini 620b210fafSSean Christopherson static bool nx_hugepage_mitigation_hard_disabled; 630b210fafSSean Christopherson 64a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 654dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 66c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 67c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 68c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 69c50d8ae3SPaolo Bonzini #else 70c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 71c50d8ae3SPaolo Bonzini #endif 72c50d8ae3SPaolo Bonzini 730b210fafSSean Christopherson static int get_nx_huge_pages(char *buffer, const struct kernel_param *kp); 74c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 754dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 76c50d8ae3SPaolo Bonzini 77d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 78c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 790b210fafSSean Christopherson .get = get_nx_huge_pages, 80c50d8ae3SPaolo Bonzini }; 81c50d8ae3SPaolo Bonzini 824dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 834dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 84c50d8ae3SPaolo Bonzini .get = param_get_uint, 85c50d8ae3SPaolo Bonzini }; 86c50d8ae3SPaolo Bonzini 87c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 88c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 894dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 90c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 91c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 924dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 934dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 944dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 95c50d8ae3SPaolo Bonzini 9671fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9771fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9871fe7013SSean Christopherson 99c50d8ae3SPaolo Bonzini /* 100c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 101c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 102c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 103c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 104c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 105c50d8ae3SPaolo Bonzini */ 106c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 107c50d8ae3SPaolo Bonzini 1087f604e92SDavid Matlack static bool __ro_after_init tdp_mmu_allowed; 1091f98f2bdSDavid Matlack 1101f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 1111f98f2bdSDavid Matlack bool __read_mostly tdp_mmu_enabled = true; 1121f98f2bdSDavid Matlack module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0444); 1131f98f2bdSDavid Matlack #endif 1141f98f2bdSDavid Matlack 1151d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 116746700d2SWei Huang static int tdp_root_level __read_mostly; 11783013059SSean Christopherson static int max_tdp_level __read_mostly; 118703c335dSSean Christopherson 119c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 120c50d8ae3SPaolo Bonzini 121c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 122c50d8ae3SPaolo Bonzini 123dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 12413236e25SPeter Xu #define PTE_LIST_EXT 14 125c50d8ae3SPaolo Bonzini 12613236e25SPeter Xu /* 127141705b7SLai Jiangshan * struct pte_list_desc is the core data structure used to implement a custom 128141705b7SLai Jiangshan * list for tracking a set of related SPTEs, e.g. all the SPTEs that map a 129141705b7SLai Jiangshan * given GFN when used in the context of rmaps. Using a custom list allows KVM 130141705b7SLai Jiangshan * to optimize for the common case where many GFNs will have at most a handful 131141705b7SLai Jiangshan * of SPTEs pointing at them, i.e. allows packing multiple SPTEs into a small 132141705b7SLai Jiangshan * memory footprint, which in turn improves runtime performance by exploiting 133141705b7SLai Jiangshan * cache locality. 134141705b7SLai Jiangshan * 135141705b7SLai Jiangshan * A list is comprised of one or more pte_list_desc objects (descriptors). 136141705b7SLai Jiangshan * Each individual descriptor stores up to PTE_LIST_EXT SPTEs. If a descriptor 137141705b7SLai Jiangshan * is full and a new SPTEs needs to be added, a new descriptor is allocated and 138141705b7SLai Jiangshan * becomes the head of the list. This means that by definitions, all tail 139141705b7SLai Jiangshan * descriptors are full. 140141705b7SLai Jiangshan * 141141705b7SLai Jiangshan * Note, the meta data fields are deliberately placed at the start of the 142141705b7SLai Jiangshan * structure to optimize the cacheline layout; accessing the descriptor will 143141705b7SLai Jiangshan * touch only a single cacheline so long as @spte_count<=6 (or if only the 144141705b7SLai Jiangshan * descriptors metadata is accessed). 14513236e25SPeter Xu */ 146c50d8ae3SPaolo Bonzini struct pte_list_desc { 147c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 148141705b7SLai Jiangshan /* The number of PTEs stored in _this_ descriptor. */ 149141705b7SLai Jiangshan u32 spte_count; 150141705b7SLai Jiangshan /* The number of PTEs stored in all tails of this descriptor. */ 151141705b7SLai Jiangshan u32 tail_count; 15213236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 153c50d8ae3SPaolo Bonzini }; 154c50d8ae3SPaolo Bonzini 155c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 156c50d8ae3SPaolo Bonzini u64 addr; 157c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 158c50d8ae3SPaolo Bonzini u64 *sptep; 159c50d8ae3SPaolo Bonzini int level; 160c50d8ae3SPaolo Bonzini unsigned index; 161c50d8ae3SPaolo Bonzini }; 162c50d8ae3SPaolo Bonzini 163c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 164c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 165c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 166c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 167c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 168c50d8ae3SPaolo Bonzini 169c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 170c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 171c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 172c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 173c50d8ae3SPaolo Bonzini 174c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 175c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 176c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 177c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 178c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 179c50d8ae3SPaolo Bonzini 180c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 18102c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 182c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 183c50d8ae3SPaolo Bonzini 184c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 185c50d8ae3SPaolo Bonzini 186594e91a1SSean Christopherson struct kvm_mmu_role_regs { 187594e91a1SSean Christopherson const unsigned long cr0; 188594e91a1SSean Christopherson const unsigned long cr4; 189594e91a1SSean Christopherson const u64 efer; 190594e91a1SSean Christopherson }; 191594e91a1SSean Christopherson 192c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 193c50d8ae3SPaolo Bonzini #include "mmutrace.h" 194c50d8ae3SPaolo Bonzini 195594e91a1SSean Christopherson /* 196594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1977a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 198594e91a1SSean Christopherson * the single source of truth for the MMU's state. 199594e91a1SSean Christopherson */ 200594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 20182ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 20282ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 203594e91a1SSean Christopherson { \ 204594e91a1SSean Christopherson return !!(regs->reg & flag); \ 205594e91a1SSean Christopherson } 206594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 207594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 208594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 209594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 210594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 211594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 212594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 213594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 214594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 215594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 216594e91a1SSean Christopherson 21760667724SSean Christopherson /* 21860667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 21960667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 22060667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 22160667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 22260667724SSean Christopherson */ 22360667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2244ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 22560667724SSean Christopherson { \ 226e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 22760667724SSean Christopherson } 22860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 22960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 23060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 23160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 23260667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 23360667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 23460667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 23556b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 23660667724SSean Christopherson 237faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 238faf72962SPaolo Bonzini { 239faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 240faf72962SPaolo Bonzini } 241faf72962SPaolo Bonzini 242faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 243faf72962SPaolo Bonzini { 244faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 245faf72962SPaolo Bonzini } 246faf72962SPaolo Bonzini 247594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 248594e91a1SSean Christopherson { 249594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 250594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 251594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 252594e91a1SSean Christopherson .efer = vcpu->arch.efer, 253594e91a1SSean Christopherson }; 254594e91a1SSean Christopherson 255594e91a1SSean Christopherson return regs; 256594e91a1SSean Christopherson } 257c50d8ae3SPaolo Bonzini 2582fdcc1b3SPaolo Bonzini static unsigned long get_guest_cr3(struct kvm_vcpu *vcpu) 259c50d8ae3SPaolo Bonzini { 2602fdcc1b3SPaolo Bonzini return kvm_read_cr3(vcpu); 261c50d8ae3SPaolo Bonzini } 262c50d8ae3SPaolo Bonzini 2632fdcc1b3SPaolo Bonzini static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu, 2642fdcc1b3SPaolo Bonzini struct kvm_mmu *mmu) 265c50d8ae3SPaolo Bonzini { 266aefb2f2eSBreno Leitao if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && mmu->get_guest_pgd == get_guest_cr3) 2672fdcc1b3SPaolo Bonzini return kvm_read_cr3(vcpu); 268c50d8ae3SPaolo Bonzini 2692fdcc1b3SPaolo Bonzini return mmu->get_guest_pgd(vcpu); 2702fdcc1b3SPaolo Bonzini } 271c50d8ae3SPaolo Bonzini 2728a1300ffSSean Christopherson static inline bool kvm_available_flush_remote_tlbs_range(void) 273c50d8ae3SPaolo Bonzini { 2740277022aSSean Christopherson #if IS_ENABLED(CONFIG_HYPERV) 2758a1300ffSSean Christopherson return kvm_x86_ops.flush_remote_tlbs_range; 2760277022aSSean Christopherson #else 2770277022aSSean Christopherson return false; 2780277022aSSean Christopherson #endif 279c50d8ae3SPaolo Bonzini } 280c50d8ae3SPaolo Bonzini 2811b2dc736SHou Wenlong static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index); 2821b2dc736SHou Wenlong 2831b2dc736SHou Wenlong /* Flush the range of guest memory mapped by the given SPTE. */ 2841b2dc736SHou Wenlong static void kvm_flush_remote_tlbs_sptep(struct kvm *kvm, u64 *sptep) 2851b2dc736SHou Wenlong { 2861b2dc736SHou Wenlong struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2871b2dc736SHou Wenlong gfn_t gfn = kvm_mmu_page_get_gfn(sp, spte_index(sptep)); 2881b2dc736SHou Wenlong 2891b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 2901b2dc736SHou Wenlong } 2911b2dc736SHou Wenlong 2928f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2938f79b064SBen Gardon unsigned int access) 2948f79b064SBen Gardon { 295c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2968f79b064SBen Gardon 297c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 298c236d962SSean Christopherson mmu_spte_set(sptep, spte); 299c50d8ae3SPaolo Bonzini } 300c50d8ae3SPaolo Bonzini 301c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 302c50d8ae3SPaolo Bonzini { 303c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 304c50d8ae3SPaolo Bonzini 3058a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 306c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 307c50d8ae3SPaolo Bonzini 308c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 309c50d8ae3SPaolo Bonzini } 310c50d8ae3SPaolo Bonzini 311c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 312c50d8ae3SPaolo Bonzini { 313c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 314c50d8ae3SPaolo Bonzini } 315c50d8ae3SPaolo Bonzini 316c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 317c50d8ae3SPaolo Bonzini { 318c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 319c50d8ae3SPaolo Bonzini 320c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 321c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 322c50d8ae3SPaolo Bonzini return false; 323c50d8ae3SPaolo Bonzini 324c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 325c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 326c50d8ae3SPaolo Bonzini 327c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 328c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 329c50d8ae3SPaolo Bonzini } 330c50d8ae3SPaolo Bonzini 331c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 332c50d8ae3SPaolo Bonzini { 333c50d8ae3SPaolo Bonzini return 1; 334c50d8ae3SPaolo Bonzini } 335c50d8ae3SPaolo Bonzini 336c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 337c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 338c50d8ae3SPaolo Bonzini { 339c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 340c50d8ae3SPaolo Bonzini } 341c50d8ae3SPaolo Bonzini 342c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 343c50d8ae3SPaolo Bonzini { 344c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 345c50d8ae3SPaolo Bonzini } 346c50d8ae3SPaolo Bonzini 347c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 348c50d8ae3SPaolo Bonzini { 349c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 350c50d8ae3SPaolo Bonzini } 351c50d8ae3SPaolo Bonzini 352c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 353c50d8ae3SPaolo Bonzini { 354c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 355c50d8ae3SPaolo Bonzini } 356c50d8ae3SPaolo Bonzini #else 357c50d8ae3SPaolo Bonzini union split_spte { 358c50d8ae3SPaolo Bonzini struct { 359c50d8ae3SPaolo Bonzini u32 spte_low; 360c50d8ae3SPaolo Bonzini u32 spte_high; 361c50d8ae3SPaolo Bonzini }; 362c50d8ae3SPaolo Bonzini u64 spte; 363c50d8ae3SPaolo Bonzini }; 364c50d8ae3SPaolo Bonzini 365c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 366c50d8ae3SPaolo Bonzini { 36757354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 368c50d8ae3SPaolo Bonzini 369c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 370c50d8ae3SPaolo Bonzini return; 371c50d8ae3SPaolo Bonzini 372c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 373c50d8ae3SPaolo Bonzini smp_wmb(); 374c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 375c50d8ae3SPaolo Bonzini } 376c50d8ae3SPaolo Bonzini 377c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 378c50d8ae3SPaolo Bonzini { 379c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 380c50d8ae3SPaolo Bonzini 381c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 382c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 383c50d8ae3SPaolo Bonzini 384c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 385c50d8ae3SPaolo Bonzini 386c50d8ae3SPaolo Bonzini /* 387c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 388c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 389c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 390c50d8ae3SPaolo Bonzini */ 391c50d8ae3SPaolo Bonzini smp_wmb(); 392c50d8ae3SPaolo Bonzini 393c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 394c50d8ae3SPaolo Bonzini } 395c50d8ae3SPaolo Bonzini 396c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 397c50d8ae3SPaolo Bonzini { 398c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 399c50d8ae3SPaolo Bonzini 400c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 401c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 402c50d8ae3SPaolo Bonzini 403c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 404c50d8ae3SPaolo Bonzini 405c50d8ae3SPaolo Bonzini /* 406c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 407c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 408c50d8ae3SPaolo Bonzini */ 409c50d8ae3SPaolo Bonzini smp_wmb(); 410c50d8ae3SPaolo Bonzini 411c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 412c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 413c50d8ae3SPaolo Bonzini } 414c50d8ae3SPaolo Bonzini 415c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 416c50d8ae3SPaolo Bonzini { 417c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 418c50d8ae3SPaolo Bonzini 419c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 420c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 421c50d8ae3SPaolo Bonzini 422c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 423c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 424c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 425c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 426c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 427c50d8ae3SPaolo Bonzini 428c50d8ae3SPaolo Bonzini return orig.spte; 429c50d8ae3SPaolo Bonzini } 430c50d8ae3SPaolo Bonzini 431c50d8ae3SPaolo Bonzini /* 432c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 433c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 434c50d8ae3SPaolo Bonzini * 435f3b65bbaSPaolo Bonzini * An spte tlb flush may be pending, because they are coalesced and 436f3b65bbaSPaolo Bonzini * we are running out of the MMU lock. Therefore 437c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 438c50d8ae3SPaolo Bonzini * 439c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 440c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 441c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 442c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 443c50d8ae3SPaolo Bonzini * 444c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 445c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 446c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 447c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 448c50d8ae3SPaolo Bonzini */ 449c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 450c50d8ae3SPaolo Bonzini { 45157354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 452c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 453c50d8ae3SPaolo Bonzini int count; 454c50d8ae3SPaolo Bonzini 455c50d8ae3SPaolo Bonzini retry: 456c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 457c50d8ae3SPaolo Bonzini smp_rmb(); 458c50d8ae3SPaolo Bonzini 459c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 460c50d8ae3SPaolo Bonzini smp_rmb(); 461c50d8ae3SPaolo Bonzini 462c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 463c50d8ae3SPaolo Bonzini smp_rmb(); 464c50d8ae3SPaolo Bonzini 465c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 466c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 467c50d8ae3SPaolo Bonzini goto retry; 468c50d8ae3SPaolo Bonzini 469c50d8ae3SPaolo Bonzini return spte.spte; 470c50d8ae3SPaolo Bonzini } 471c50d8ae3SPaolo Bonzini #endif 472c50d8ae3SPaolo Bonzini 473c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 474c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 475c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 476c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 477c50d8ae3SPaolo Bonzini * the spte. 478c50d8ae3SPaolo Bonzini */ 479c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 480c50d8ae3SPaolo Bonzini { 48120ba462dSSean Christopherson WARN_ON_ONCE(is_shadow_present_pte(*sptep)); 482c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 483c50d8ae3SPaolo Bonzini } 484c50d8ae3SPaolo Bonzini 485c50d8ae3SPaolo Bonzini /* 486c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 487c50d8ae3SPaolo Bonzini * accessed/dirty status. 488c50d8ae3SPaolo Bonzini */ 489c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 490c50d8ae3SPaolo Bonzini { 491c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 492c50d8ae3SPaolo Bonzini 49320ba462dSSean Christopherson WARN_ON_ONCE(!is_shadow_present_pte(new_spte)); 494115111efSDavid Matlack check_spte_writable_invariants(new_spte); 495c50d8ae3SPaolo Bonzini 496c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 497c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 498c50d8ae3SPaolo Bonzini return old_spte; 499c50d8ae3SPaolo Bonzini } 500c50d8ae3SPaolo Bonzini 501c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 502c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 503c50d8ae3SPaolo Bonzini else 504c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 505c50d8ae3SPaolo Bonzini 50620ba462dSSean Christopherson WARN_ON_ONCE(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 507c50d8ae3SPaolo Bonzini 508c50d8ae3SPaolo Bonzini return old_spte; 509c50d8ae3SPaolo Bonzini } 510c50d8ae3SPaolo Bonzini 511c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 512c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 513c50d8ae3SPaolo Bonzini * 51402844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 51502844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 51602844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 517c50d8ae3SPaolo Bonzini * 518c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 519c50d8ae3SPaolo Bonzini */ 520c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 521c50d8ae3SPaolo Bonzini { 522c50d8ae3SPaolo Bonzini bool flush = false; 523c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 524c50d8ae3SPaolo Bonzini 525c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 526c50d8ae3SPaolo Bonzini return false; 527c50d8ae3SPaolo Bonzini 528c50d8ae3SPaolo Bonzini /* 529c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 530c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 531c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 532c50d8ae3SPaolo Bonzini */ 533706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 534c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 535c50d8ae3SPaolo Bonzini flush = true; 536c50d8ae3SPaolo Bonzini 537c50d8ae3SPaolo Bonzini /* 538c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 539c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 540c50d8ae3SPaolo Bonzini */ 541c50d8ae3SPaolo Bonzini 542c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 543c50d8ae3SPaolo Bonzini flush = true; 544c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 545c50d8ae3SPaolo Bonzini } 546c50d8ae3SPaolo Bonzini 547c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 548c50d8ae3SPaolo Bonzini flush = true; 549c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 550c50d8ae3SPaolo Bonzini } 551c50d8ae3SPaolo Bonzini 552c50d8ae3SPaolo Bonzini return flush; 553c50d8ae3SPaolo Bonzini } 554c50d8ae3SPaolo Bonzini 555c50d8ae3SPaolo Bonzini /* 556c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 557c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 558c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5597fa2a347SSean Christopherson * Returns the old PTE. 560c50d8ae3SPaolo Bonzini */ 56135d539c3SSean Christopherson static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 562c50d8ae3SPaolo Bonzini { 563c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 564c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 56571f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 566b14b2690SSean Christopherson struct page *page; 567c50d8ae3SPaolo Bonzini 56854eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 56954eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 570c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 571c50d8ae3SPaolo Bonzini else 572c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 573c50d8ae3SPaolo Bonzini 574c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5757fa2a347SSean Christopherson return old_spte; 576c50d8ae3SPaolo Bonzini 57771f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 57871f51d2cSMingwei Zhang 579c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 580c50d8ae3SPaolo Bonzini 581c50d8ae3SPaolo Bonzini /* 582b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 583b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 584b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 585b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 586c50d8ae3SPaolo Bonzini */ 587b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 58820ba462dSSean Christopherson WARN_ON_ONCE(page && !page_count(page)); 589c50d8ae3SPaolo Bonzini 590c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 591c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 592c50d8ae3SPaolo Bonzini 593c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 594c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 595c50d8ae3SPaolo Bonzini 5967fa2a347SSean Christopherson return old_spte; 597c50d8ae3SPaolo Bonzini } 598c50d8ae3SPaolo Bonzini 599c50d8ae3SPaolo Bonzini /* 600c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 601c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 602c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 603c50d8ae3SPaolo Bonzini */ 604c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 605c50d8ae3SPaolo Bonzini { 606c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 607c50d8ae3SPaolo Bonzini } 608c50d8ae3SPaolo Bonzini 609c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 610c50d8ae3SPaolo Bonzini { 611c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 612c50d8ae3SPaolo Bonzini } 613c50d8ae3SPaolo Bonzini 614c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 615c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 616c50d8ae3SPaolo Bonzini { 617c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 618c50d8ae3SPaolo Bonzini 619c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 620c50d8ae3SPaolo Bonzini return false; 621c50d8ae3SPaolo Bonzini 622c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 623c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 624c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 625c50d8ae3SPaolo Bonzini } else { 626c50d8ae3SPaolo Bonzini /* 627c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 628c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 629c50d8ae3SPaolo Bonzini */ 630c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 631c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 632c50d8ae3SPaolo Bonzini 633c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 634c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 635c50d8ae3SPaolo Bonzini } 636c50d8ae3SPaolo Bonzini 637c50d8ae3SPaolo Bonzini return true; 638c50d8ae3SPaolo Bonzini } 639c50d8ae3SPaolo Bonzini 64078fdd2f0SSean Christopherson static inline bool is_tdp_mmu_active(struct kvm_vcpu *vcpu) 64178fdd2f0SSean Christopherson { 64278fdd2f0SSean Christopherson return tdp_mmu_enabled && vcpu->arch.mmu->root_role.direct; 64378fdd2f0SSean Christopherson } 64478fdd2f0SSean Christopherson 645c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 646c50d8ae3SPaolo Bonzini { 64778fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 648c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 649c5c8c7c5SDavid Matlack } else { 650c50d8ae3SPaolo Bonzini /* 651c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 652c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 653c50d8ae3SPaolo Bonzini */ 654c50d8ae3SPaolo Bonzini local_irq_disable(); 655c50d8ae3SPaolo Bonzini 656c50d8ae3SPaolo Bonzini /* 657c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 658c50d8ae3SPaolo Bonzini * to vcpu->mode. 659c50d8ae3SPaolo Bonzini */ 660c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 661c50d8ae3SPaolo Bonzini } 662c5c8c7c5SDavid Matlack } 663c50d8ae3SPaolo Bonzini 664c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 665c50d8ae3SPaolo Bonzini { 66678fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 667c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 668c5c8c7c5SDavid Matlack } else { 669c50d8ae3SPaolo Bonzini /* 670c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 671c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 672c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 673c50d8ae3SPaolo Bonzini */ 674c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 675c50d8ae3SPaolo Bonzini local_irq_enable(); 676c50d8ae3SPaolo Bonzini } 677c5c8c7c5SDavid Matlack } 678c50d8ae3SPaolo Bonzini 679378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 680c50d8ae3SPaolo Bonzini { 681c50d8ae3SPaolo Bonzini int r; 682c50d8ae3SPaolo Bonzini 683531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 68494ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 685531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 686c50d8ae3SPaolo Bonzini if (r) 687c50d8ae3SPaolo Bonzini return r; 68894ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 689171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 690171a90d7SSean Christopherson if (r) 691171a90d7SSean Christopherson return r; 692378f5cd6SSean Christopherson if (maybe_indirect) { 6936a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 694171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 695c50d8ae3SPaolo Bonzini if (r) 696c50d8ae3SPaolo Bonzini return r; 697378f5cd6SSean Christopherson } 69894ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 699531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 700c50d8ae3SPaolo Bonzini } 701c50d8ae3SPaolo Bonzini 702c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 703c50d8ae3SPaolo Bonzini { 70494ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 70594ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 7066a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 70794ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 708c50d8ae3SPaolo Bonzini } 709c50d8ae3SPaolo Bonzini 710c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 711c50d8ae3SPaolo Bonzini { 712c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 713c50d8ae3SPaolo Bonzini } 714c50d8ae3SPaolo Bonzini 7156a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 7166a97575dSDavid Matlack 717c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 718c50d8ae3SPaolo Bonzini { 71984e5ffd0SLai Jiangshan if (sp->role.passthrough) 72084e5ffd0SLai Jiangshan return sp->gfn; 72184e5ffd0SLai Jiangshan 722c50d8ae3SPaolo Bonzini if (!sp->role.direct) 7236a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 724c50d8ae3SPaolo Bonzini 7252ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 726c50d8ae3SPaolo Bonzini } 727c50d8ae3SPaolo Bonzini 7286a97575dSDavid Matlack /* 7296a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 7306a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 7316a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 7326a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 7336a97575dSDavid Matlack */ 7346a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 735c50d8ae3SPaolo Bonzini { 7366a97575dSDavid Matlack if (sp_has_gptes(sp)) 7376a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7386a97575dSDavid Matlack 7396a97575dSDavid Matlack /* 7406a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7416a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7426a97575dSDavid Matlack * permissions" are just ACC_ALL. 7436a97575dSDavid Matlack * 7446a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7456a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7466a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7476a97575dSDavid Matlack * page. 7486a97575dSDavid Matlack * 7496a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7506a97575dSDavid Matlack */ 7516a97575dSDavid Matlack return sp->role.access; 7526a97575dSDavid Matlack } 7536a97575dSDavid Matlack 75472ae5822SSean Christopherson static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, 75572ae5822SSean Christopherson gfn_t gfn, unsigned int access) 7566a97575dSDavid Matlack { 7576a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7586a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 75984e5ffd0SLai Jiangshan return; 76084e5ffd0SLai Jiangshan } 76184e5ffd0SLai Jiangshan 7626a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7636a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7646a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7656a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7666a97575dSDavid Matlack 7676a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7686a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7696a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7706a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 771c50d8ae3SPaolo Bonzini } 772c50d8ae3SPaolo Bonzini 77372ae5822SSean Christopherson static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, 77472ae5822SSean Christopherson unsigned int access) 7756a97575dSDavid Matlack { 7766a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7776a97575dSDavid Matlack 7786a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 779c50d8ae3SPaolo Bonzini } 780c50d8ae3SPaolo Bonzini 781c50d8ae3SPaolo Bonzini /* 782c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 783c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 784c50d8ae3SPaolo Bonzini */ 785c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7868ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 787c50d8ae3SPaolo Bonzini { 788c50d8ae3SPaolo Bonzini unsigned long idx; 789c50d8ae3SPaolo Bonzini 790c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 791c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 792c50d8ae3SPaolo Bonzini } 793c50d8ae3SPaolo Bonzini 79490b4fe17SChao Peng /* 79590b4fe17SChao Peng * The most significant bit in disallow_lpage tracks whether or not memory 79690b4fe17SChao Peng * attributes are mixed, i.e. not identical for all gfns at the current level. 79790b4fe17SChao Peng * The lower order bits are used to refcount other cases where a hugepage is 79890b4fe17SChao Peng * disallowed, e.g. if KVM has shadow a page table at the gfn. 79990b4fe17SChao Peng */ 80090b4fe17SChao Peng #define KVM_LPAGE_MIXED_FLAG BIT(31) 80190b4fe17SChao Peng 802269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 803c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 804c50d8ae3SPaolo Bonzini { 805c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 80690b4fe17SChao Peng int old, i; 807c50d8ae3SPaolo Bonzini 8083bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 809c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 81090b4fe17SChao Peng 81190b4fe17SChao Peng old = linfo->disallow_lpage; 812c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 81390b4fe17SChao Peng WARN_ON_ONCE((old ^ linfo->disallow_lpage) & KVM_LPAGE_MIXED_FLAG); 814c50d8ae3SPaolo Bonzini } 815c50d8ae3SPaolo Bonzini } 816c50d8ae3SPaolo Bonzini 817269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 818c50d8ae3SPaolo Bonzini { 819c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 820c50d8ae3SPaolo Bonzini } 821c50d8ae3SPaolo Bonzini 822269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 823c50d8ae3SPaolo Bonzini { 824c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 825c50d8ae3SPaolo Bonzini } 826c50d8ae3SPaolo Bonzini 827c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 828c50d8ae3SPaolo Bonzini { 829c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 830c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 831c50d8ae3SPaolo Bonzini gfn_t gfn; 832c50d8ae3SPaolo Bonzini 833c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 834c50d8ae3SPaolo Bonzini gfn = sp->gfn; 835c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 836c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 837c50d8ae3SPaolo Bonzini 838c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8393bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 84096316a06SSean Christopherson return __kvm_write_track_add_gfn(kvm, slot, gfn); 841c50d8ae3SPaolo Bonzini 842c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 843be911771SDavid Matlack 844be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 8454ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, PG_LEVEL_4K); 846c50d8ae3SPaolo Bonzini } 847c50d8ae3SPaolo Bonzini 84861f94478SSean Christopherson void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 849c50d8ae3SPaolo Bonzini { 850428e9216SSean Christopherson /* 851428e9216SSean Christopherson * If it's possible to replace the shadow page with an NX huge page, 852428e9216SSean Christopherson * i.e. if the shadow page is the only thing currently preventing KVM 853428e9216SSean Christopherson * from using a huge page, add the shadow page to the list of "to be 854428e9216SSean Christopherson * zapped for NX recovery" pages. Note, the shadow page can already be 855428e9216SSean Christopherson * on the list if KVM is reusing an existing shadow page, i.e. if KVM 856428e9216SSean Christopherson * links a shadow page at multiple points. 857428e9216SSean Christopherson */ 85861f94478SSean Christopherson if (!list_empty(&sp->possible_nx_huge_page_link)) 859c50d8ae3SPaolo Bonzini return; 860c50d8ae3SPaolo Bonzini 861c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 86255c510e2SSean Christopherson list_add_tail(&sp->possible_nx_huge_page_link, 86355c510e2SSean Christopherson &kvm->arch.possible_nx_huge_pages); 864c50d8ae3SPaolo Bonzini } 865c50d8ae3SPaolo Bonzini 86661f94478SSean Christopherson static void account_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp, 86761f94478SSean Christopherson bool nx_huge_page_possible) 86861f94478SSean Christopherson { 86961f94478SSean Christopherson sp->nx_huge_page_disallowed = true; 87061f94478SSean Christopherson 87161f94478SSean Christopherson if (nx_huge_page_possible) 87261f94478SSean Christopherson track_possible_nx_huge_page(kvm, sp); 873c50d8ae3SPaolo Bonzini } 874c50d8ae3SPaolo Bonzini 875c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 876c50d8ae3SPaolo Bonzini { 877c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 878c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 879c50d8ae3SPaolo Bonzini gfn_t gfn; 880c50d8ae3SPaolo Bonzini 881c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 882c50d8ae3SPaolo Bonzini gfn = sp->gfn; 883c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 884c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8853bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 88696316a06SSean Christopherson return __kvm_write_track_remove_gfn(kvm, slot, gfn); 887c50d8ae3SPaolo Bonzini 888c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 889c50d8ae3SPaolo Bonzini } 890c50d8ae3SPaolo Bonzini 89161f94478SSean Christopherson void untrack_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 892c50d8ae3SPaolo Bonzini { 89355c510e2SSean Christopherson if (list_empty(&sp->possible_nx_huge_page_link)) 894428e9216SSean Christopherson return; 895428e9216SSean Christopherson 896c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 89755c510e2SSean Christopherson list_del_init(&sp->possible_nx_huge_page_link); 898c50d8ae3SPaolo Bonzini } 899c50d8ae3SPaolo Bonzini 90061f94478SSean Christopherson static void unaccount_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 90161f94478SSean Christopherson { 90261f94478SSean Christopherson sp->nx_huge_page_disallowed = false; 90361f94478SSean Christopherson 90461f94478SSean Christopherson untrack_possible_nx_huge_page(kvm, sp); 905c50d8ae3SPaolo Bonzini } 906c50d8ae3SPaolo Bonzini 907f3d90f90SSean Christopherson static struct kvm_memory_slot *gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, 908f3d90f90SSean Christopherson gfn_t gfn, 909c50d8ae3SPaolo Bonzini bool no_dirty_log) 910c50d8ae3SPaolo Bonzini { 911c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 912c50d8ae3SPaolo Bonzini 913c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 91491b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 91591b0d268SPaolo Bonzini return NULL; 916044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 91791b0d268SPaolo Bonzini return NULL; 918c50d8ae3SPaolo Bonzini 919c50d8ae3SPaolo Bonzini return slot; 920c50d8ae3SPaolo Bonzini } 921c50d8ae3SPaolo Bonzini 922c50d8ae3SPaolo Bonzini /* 923c50d8ae3SPaolo Bonzini * About rmap_head encoding: 924c50d8ae3SPaolo Bonzini * 925c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 926c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 927c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 928c50d8ae3SPaolo Bonzini */ 929c50d8ae3SPaolo Bonzini 930c50d8ae3SPaolo Bonzini /* 931c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 932c50d8ae3SPaolo Bonzini */ 9332ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 934c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 935c50d8ae3SPaolo Bonzini { 936c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 93713236e25SPeter Xu int count = 0; 938c50d8ae3SPaolo Bonzini 939c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 940c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 941c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 9422ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 943c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 944c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 94513236e25SPeter Xu desc->spte_count = 2; 946141705b7SLai Jiangshan desc->tail_count = 0; 947c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 948c50d8ae3SPaolo Bonzini ++count; 949c50d8ae3SPaolo Bonzini } else { 950c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 951141705b7SLai Jiangshan count = desc->tail_count + desc->spte_count; 952141705b7SLai Jiangshan 953141705b7SLai Jiangshan /* 954141705b7SLai Jiangshan * If the previous head is full, allocate a new head descriptor 955141705b7SLai Jiangshan * as tail descriptors are always kept full. 956141705b7SLai Jiangshan */ 957141705b7SLai Jiangshan if (desc->spte_count == PTE_LIST_EXT) { 958141705b7SLai Jiangshan desc = kvm_mmu_memory_cache_alloc(cache); 959141705b7SLai Jiangshan desc->more = (struct pte_list_desc *)(rmap_head->val & ~1ul); 96013236e25SPeter Xu desc->spte_count = 0; 961141705b7SLai Jiangshan desc->tail_count = count; 962141705b7SLai Jiangshan rmap_head->val = (unsigned long)desc | 1; 963c6c4f961SLi RongQing } 96413236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 965c50d8ae3SPaolo Bonzini } 966c50d8ae3SPaolo Bonzini return count; 967c50d8ae3SPaolo Bonzini } 968c50d8ae3SPaolo Bonzini 969069f30c6SMingwei Zhang static void pte_list_desc_remove_entry(struct kvm *kvm, 970069f30c6SMingwei Zhang struct kvm_rmap_head *rmap_head, 971141705b7SLai Jiangshan struct pte_list_desc *desc, int i) 972c50d8ae3SPaolo Bonzini { 973141705b7SLai Jiangshan struct pte_list_desc *head_desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 974141705b7SLai Jiangshan int j = head_desc->spte_count - 1; 975c50d8ae3SPaolo Bonzini 976141705b7SLai Jiangshan /* 977141705b7SLai Jiangshan * The head descriptor should never be empty. A new head is added only 978141705b7SLai Jiangshan * when adding an entry and the previous head is full, and heads are 979141705b7SLai Jiangshan * removed (this flow) when they become empty. 980141705b7SLai Jiangshan */ 98152e322edSSean Christopherson KVM_BUG_ON_DATA_CORRUPTION(j < 0, kvm); 982141705b7SLai Jiangshan 983141705b7SLai Jiangshan /* 984141705b7SLai Jiangshan * Replace the to-be-freed SPTE with the last valid entry from the head 985141705b7SLai Jiangshan * descriptor to ensure that tail descriptors are full at all times. 986141705b7SLai Jiangshan * Note, this also means that tail_count is stable for each descriptor. 987141705b7SLai Jiangshan */ 988141705b7SLai Jiangshan desc->sptes[i] = head_desc->sptes[j]; 989141705b7SLai Jiangshan head_desc->sptes[j] = NULL; 990141705b7SLai Jiangshan head_desc->spte_count--; 991141705b7SLai Jiangshan if (head_desc->spte_count) 992c50d8ae3SPaolo Bonzini return; 993141705b7SLai Jiangshan 994141705b7SLai Jiangshan /* 995141705b7SLai Jiangshan * The head descriptor is empty. If there are no tail descriptors, 99654aa699eSBjorn Helgaas * nullify the rmap head to mark the list as empty, else point the rmap 997141705b7SLai Jiangshan * head at the next descriptor, i.e. the new head. 998141705b7SLai Jiangshan */ 999141705b7SLai Jiangshan if (!head_desc->more) 1000fe3c2b4cSMiaohe Lin rmap_head->val = 0; 1001c50d8ae3SPaolo Bonzini else 1002141705b7SLai Jiangshan rmap_head->val = (unsigned long)head_desc->more | 1; 1003141705b7SLai Jiangshan mmu_free_pte_list_desc(head_desc); 1004c50d8ae3SPaolo Bonzini } 1005c50d8ae3SPaolo Bonzini 1006069f30c6SMingwei Zhang static void pte_list_remove(struct kvm *kvm, u64 *spte, 1007069f30c6SMingwei Zhang struct kvm_rmap_head *rmap_head) 1008c50d8ae3SPaolo Bonzini { 1009c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 1010c50d8ae3SPaolo Bonzini int i; 1011c50d8ae3SPaolo Bonzini 101252e322edSSean Christopherson if (KVM_BUG_ON_DATA_CORRUPTION(!rmap_head->val, kvm)) 101352e322edSSean Christopherson return; 101452e322edSSean Christopherson 101552e322edSSean Christopherson if (!(rmap_head->val & 1)) { 101652e322edSSean Christopherson if (KVM_BUG_ON_DATA_CORRUPTION((u64 *)rmap_head->val != spte, kvm)) 101752e322edSSean Christopherson return; 101852e322edSSean Christopherson 1019c50d8ae3SPaolo Bonzini rmap_head->val = 0; 1020c50d8ae3SPaolo Bonzini } else { 1021c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1022c50d8ae3SPaolo Bonzini while (desc) { 102313236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 1024c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 1025069f30c6SMingwei Zhang pte_list_desc_remove_entry(kvm, rmap_head, 1026069f30c6SMingwei Zhang desc, i); 1027c50d8ae3SPaolo Bonzini return; 1028c50d8ae3SPaolo Bonzini } 1029c50d8ae3SPaolo Bonzini } 1030c50d8ae3SPaolo Bonzini desc = desc->more; 1031c50d8ae3SPaolo Bonzini } 103252e322edSSean Christopherson 103352e322edSSean Christopherson KVM_BUG_ON_DATA_CORRUPTION(true, kvm); 1034c50d8ae3SPaolo Bonzini } 1035c50d8ae3SPaolo Bonzini } 1036c50d8ae3SPaolo Bonzini 10379202aee8SSean Christopherson static void kvm_zap_one_rmap_spte(struct kvm *kvm, 10389202aee8SSean Christopherson struct kvm_rmap_head *rmap_head, u64 *sptep) 1039c50d8ae3SPaolo Bonzini { 104071f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1041069f30c6SMingwei Zhang pte_list_remove(kvm, sptep, rmap_head); 1042c50d8ae3SPaolo Bonzini } 1043c50d8ae3SPaolo Bonzini 10449202aee8SSean Christopherson /* Return true if at least one SPTE was zapped, false otherwise */ 10459202aee8SSean Christopherson static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 10469202aee8SSean Christopherson struct kvm_rmap_head *rmap_head) 1047a75b5404SPeter Xu { 1048a75b5404SPeter Xu struct pte_list_desc *desc, *next; 1049a75b5404SPeter Xu int i; 1050a75b5404SPeter Xu 1051a75b5404SPeter Xu if (!rmap_head->val) 1052a75b5404SPeter Xu return false; 1053a75b5404SPeter Xu 1054a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 105571f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 1056a75b5404SPeter Xu goto out; 1057a75b5404SPeter Xu } 1058a75b5404SPeter Xu 1059a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1060a75b5404SPeter Xu 1061a75b5404SPeter Xu for (; desc; desc = next) { 1062a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 106371f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 1064a75b5404SPeter Xu next = desc->more; 1065a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 1066a75b5404SPeter Xu } 1067a75b5404SPeter Xu out: 1068a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 1069a75b5404SPeter Xu rmap_head->val = 0; 1070a75b5404SPeter Xu return true; 1071a75b5404SPeter Xu } 1072a75b5404SPeter Xu 10733bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10743bcd0662SPeter Xu { 10753bcd0662SPeter Xu struct pte_list_desc *desc; 10763bcd0662SPeter Xu 10773bcd0662SPeter Xu if (!rmap_head->val) 10783bcd0662SPeter Xu return 0; 10793bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10803bcd0662SPeter Xu return 1; 10813bcd0662SPeter Xu 10823bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1083141705b7SLai Jiangshan return desc->tail_count + desc->spte_count; 10843bcd0662SPeter Xu } 10853bcd0662SPeter Xu 108693e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1087269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1088c50d8ae3SPaolo Bonzini { 1089c50d8ae3SPaolo Bonzini unsigned long idx; 1090c50d8ae3SPaolo Bonzini 1091c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10923bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1093c50d8ae3SPaolo Bonzini } 1094c50d8ae3SPaolo Bonzini 1095c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1096c50d8ae3SPaolo Bonzini { 1097601f8af0SDavid Matlack struct kvm_memslots *slots; 1098601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1099c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1100c50d8ae3SPaolo Bonzini gfn_t gfn; 1101c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1102c50d8ae3SPaolo Bonzini 110357354682SSean Christopherson sp = sptep_to_sp(spte); 110479e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(spte)); 1105601f8af0SDavid Matlack 1106601f8af0SDavid Matlack /* 110768be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 110868be1306SDavid Matlack * so we have to determine which memslots to use based on context 110968be1306SDavid Matlack * information in sp->role. 1110601f8af0SDavid Matlack */ 1111601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1112601f8af0SDavid Matlack 1113601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 111493e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1115601f8af0SDavid Matlack 1116069f30c6SMingwei Zhang pte_list_remove(kvm, spte, rmap_head); 1117c50d8ae3SPaolo Bonzini } 1118c50d8ae3SPaolo Bonzini 1119c50d8ae3SPaolo Bonzini /* 1120c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1121c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1122c50d8ae3SPaolo Bonzini */ 1123c50d8ae3SPaolo Bonzini struct rmap_iterator { 1124c50d8ae3SPaolo Bonzini /* private fields */ 1125c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1126c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1127c50d8ae3SPaolo Bonzini }; 1128c50d8ae3SPaolo Bonzini 1129c50d8ae3SPaolo Bonzini /* 1130c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1131c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 11320a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1133c50d8ae3SPaolo Bonzini * 1134c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1135c50d8ae3SPaolo Bonzini */ 1136c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1137c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1138c50d8ae3SPaolo Bonzini { 1139c50d8ae3SPaolo Bonzini u64 *sptep; 1140c50d8ae3SPaolo Bonzini 1141c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1142c50d8ae3SPaolo Bonzini return NULL; 1143c50d8ae3SPaolo Bonzini 1144c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1145c50d8ae3SPaolo Bonzini iter->desc = NULL; 1146c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1147c50d8ae3SPaolo Bonzini goto out; 1148c50d8ae3SPaolo Bonzini } 1149c50d8ae3SPaolo Bonzini 1150c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1151c50d8ae3SPaolo Bonzini iter->pos = 0; 1152c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1153c50d8ae3SPaolo Bonzini out: 1154c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1155c50d8ae3SPaolo Bonzini return sptep; 1156c50d8ae3SPaolo Bonzini } 1157c50d8ae3SPaolo Bonzini 1158c50d8ae3SPaolo Bonzini /* 1159c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1160c50d8ae3SPaolo Bonzini * 1161c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1162c50d8ae3SPaolo Bonzini */ 1163c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1164c50d8ae3SPaolo Bonzini { 1165c50d8ae3SPaolo Bonzini u64 *sptep; 1166c50d8ae3SPaolo Bonzini 1167c50d8ae3SPaolo Bonzini if (iter->desc) { 1168c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1169c50d8ae3SPaolo Bonzini ++iter->pos; 1170c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1171c50d8ae3SPaolo Bonzini if (sptep) 1172c50d8ae3SPaolo Bonzini goto out; 1173c50d8ae3SPaolo Bonzini } 1174c50d8ae3SPaolo Bonzini 1175c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1176c50d8ae3SPaolo Bonzini 1177c50d8ae3SPaolo Bonzini if (iter->desc) { 1178c50d8ae3SPaolo Bonzini iter->pos = 0; 1179c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1180c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1181c50d8ae3SPaolo Bonzini goto out; 1182c50d8ae3SPaolo Bonzini } 1183c50d8ae3SPaolo Bonzini } 1184c50d8ae3SPaolo Bonzini 1185c50d8ae3SPaolo Bonzini return NULL; 1186c50d8ae3SPaolo Bonzini out: 1187c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1188c50d8ae3SPaolo Bonzini return sptep; 1189c50d8ae3SPaolo Bonzini } 1190c50d8ae3SPaolo Bonzini 1191c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1192c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1193c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1194c50d8ae3SPaolo Bonzini 1195c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1196c50d8ae3SPaolo Bonzini { 119771f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11987fa2a347SSean Christopherson 11997fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1200c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1201c50d8ae3SPaolo Bonzini } 1202c50d8ae3SPaolo Bonzini 120303787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1204c50d8ae3SPaolo Bonzini { 12050cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 12060cd8dc73SPaolo Bonzini 12070cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 120820ba462dSSean Christopherson WARN_ON_ONCE(sp->role.level == PG_LEVEL_4K); 12090cd8dc73SPaolo Bonzini 1210c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 121103787394SPaolo Bonzini 121203787394SPaolo Bonzini if (flush) 12131b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 1214c50d8ae3SPaolo Bonzini } 1215c50d8ae3SPaolo Bonzini 1216c50d8ae3SPaolo Bonzini /* 1217c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1218c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1219c50d8ae3SPaolo Bonzini * 1220c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1221c50d8ae3SPaolo Bonzini * protection: 1222c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1223c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1224c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1225c50d8ae3SPaolo Bonzini * shadow page. 1226c50d8ae3SPaolo Bonzini * 1227c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1228c50d8ae3SPaolo Bonzini */ 1229c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1230c50d8ae3SPaolo Bonzini { 1231c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1232c50d8ae3SPaolo Bonzini 1233c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1234706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1235c50d8ae3SPaolo Bonzini return false; 1236c50d8ae3SPaolo Bonzini 1237c50d8ae3SPaolo Bonzini if (pt_protect) 12385fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1239c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1240c50d8ae3SPaolo Bonzini 1241c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1242c50d8ae3SPaolo Bonzini } 1243c50d8ae3SPaolo Bonzini 12441346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1245c50d8ae3SPaolo Bonzini bool pt_protect) 1246c50d8ae3SPaolo Bonzini { 1247c50d8ae3SPaolo Bonzini u64 *sptep; 1248c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1249c50d8ae3SPaolo Bonzini bool flush = false; 1250c50d8ae3SPaolo Bonzini 1251c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1252c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1253c50d8ae3SPaolo Bonzini 1254c50d8ae3SPaolo Bonzini return flush; 1255c50d8ae3SPaolo Bonzini } 1256c50d8ae3SPaolo Bonzini 1257c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1258c50d8ae3SPaolo Bonzini { 1259c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1260c50d8ae3SPaolo Bonzini 12610fe6370eSSean Christopherson KVM_MMU_WARN_ON(!spte_ad_enabled(spte)); 1262c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1263c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1264c50d8ae3SPaolo Bonzini } 1265c50d8ae3SPaolo Bonzini 1266c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1267c50d8ae3SPaolo Bonzini { 1268c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1269c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1270c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1271c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1272c50d8ae3SPaolo Bonzini 1273c50d8ae3SPaolo Bonzini return was_writable; 1274c50d8ae3SPaolo Bonzini } 1275c50d8ae3SPaolo Bonzini 1276c50d8ae3SPaolo Bonzini /* 1277c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1278c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1279c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1280c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1281c50d8ae3SPaolo Bonzini */ 12820a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1283269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1284c50d8ae3SPaolo Bonzini { 1285c50d8ae3SPaolo Bonzini u64 *sptep; 1286c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1287c50d8ae3SPaolo Bonzini bool flush = false; 1288c50d8ae3SPaolo Bonzini 1289c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1290c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1291c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1292c50d8ae3SPaolo Bonzini else 1293c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1294c50d8ae3SPaolo Bonzini 1295c50d8ae3SPaolo Bonzini return flush; 1296c50d8ae3SPaolo Bonzini } 1297c50d8ae3SPaolo Bonzini 1298c50d8ae3SPaolo Bonzini /** 1299c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1300c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1301c50d8ae3SPaolo Bonzini * @slot: slot to protect 1302c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1303c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1304c50d8ae3SPaolo Bonzini * 130589212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1306c50d8ae3SPaolo Bonzini */ 1307c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1308c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1309c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1310c50d8ae3SPaolo Bonzini { 1311c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1312c50d8ae3SPaolo Bonzini 13131f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1314a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1315a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1316e2209710SBen Gardon 1317e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1318e2209710SBen Gardon return; 1319e2209710SBen Gardon 1320c50d8ae3SPaolo Bonzini while (mask) { 132193e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13223bae0459SSean Christopherson PG_LEVEL_4K, slot); 13231346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1324c50d8ae3SPaolo Bonzini 1325c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1326c50d8ae3SPaolo Bonzini mask &= mask - 1; 1327c50d8ae3SPaolo Bonzini } 1328c50d8ae3SPaolo Bonzini } 1329c50d8ae3SPaolo Bonzini 1330c50d8ae3SPaolo Bonzini /** 1331c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1332c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1333c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1334c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1335c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1336c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1337c50d8ae3SPaolo Bonzini * 1338c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1339c50d8ae3SPaolo Bonzini */ 1340a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1341c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1342c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1343c50d8ae3SPaolo Bonzini { 1344c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1345c50d8ae3SPaolo Bonzini 13461f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1347a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1348a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1349e2209710SBen Gardon 1350e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1351e2209710SBen Gardon return; 1352e2209710SBen Gardon 1353c50d8ae3SPaolo Bonzini while (mask) { 135493e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13553bae0459SSean Christopherson PG_LEVEL_4K, slot); 13560a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1357c50d8ae3SPaolo Bonzini 1358c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1359c50d8ae3SPaolo Bonzini mask &= mask - 1; 1360c50d8ae3SPaolo Bonzini } 1361c50d8ae3SPaolo Bonzini } 1362c50d8ae3SPaolo Bonzini 1363c50d8ae3SPaolo Bonzini /** 1364c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1365c50d8ae3SPaolo Bonzini * PT level pages. 1366c50d8ae3SPaolo Bonzini * 1367c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1368c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1369c50d8ae3SPaolo Bonzini * 137089212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 137189212919SKeqian Zhu * have such mappings. 1372c50d8ae3SPaolo Bonzini */ 1373c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1374c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1375c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1376c50d8ae3SPaolo Bonzini { 137789212919SKeqian Zhu /* 137889212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 137989212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 138089212919SKeqian Zhu * are split to 4K on the first write. 138189212919SKeqian Zhu * 138289212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 138389212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 138489212919SKeqian Zhu * pages. 138589212919SKeqian Zhu */ 138689212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 138789212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 138889212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 138989212919SKeqian Zhu 1390cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 13911aa4bb91SDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end + 1, PG_LEVEL_4K); 1392cb00a70bSDavid Matlack 139389212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 139489212919SKeqian Zhu 139589212919SKeqian Zhu /* Cross two large pages? */ 139689212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 139789212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 139889212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 139989212919SKeqian Zhu PG_LEVEL_2M); 140089212919SKeqian Zhu } 140189212919SKeqian Zhu 140289212919SKeqian Zhu /* Now handle 4K PTEs. */ 1403a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1404a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1405c50d8ae3SPaolo Bonzini else 1406c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1407c50d8ae3SPaolo Bonzini } 1408c50d8ae3SPaolo Bonzini 1409fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1410fb04a1edSPeter Xu { 14116dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1412fb04a1edSPeter Xu } 1413fb04a1edSPeter Xu 1414c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 14153ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 14163ad93562SKeqian Zhu int min_level) 1417c50d8ae3SPaolo Bonzini { 1418c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1419c50d8ae3SPaolo Bonzini int i; 1420c50d8ae3SPaolo Bonzini bool write_protected = false; 1421c50d8ae3SPaolo Bonzini 1422e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 14233ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 142493e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 14251346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1426c50d8ae3SPaolo Bonzini } 1427e2209710SBen Gardon } 1428c50d8ae3SPaolo Bonzini 14291f98f2bdSDavid Matlack if (tdp_mmu_enabled) 143046044f72SBen Gardon write_protected |= 14313ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 143246044f72SBen Gardon 1433c50d8ae3SPaolo Bonzini return write_protected; 1434c50d8ae3SPaolo Bonzini } 1435c50d8ae3SPaolo Bonzini 1436cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1437c50d8ae3SPaolo Bonzini { 1438c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1439c50d8ae3SPaolo Bonzini 1440c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 14413ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1442c50d8ae3SPaolo Bonzini } 1443c50d8ae3SPaolo Bonzini 1444f8480721SSean Christopherson static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1445269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1446c50d8ae3SPaolo Bonzini { 14479202aee8SSean Christopherson return kvm_zap_all_rmap_sptes(kvm, rmap_head); 1448c50d8ae3SPaolo Bonzini } 1449c50d8ae3SPaolo Bonzini 1450f8480721SSean Christopherson static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1451f3b65bbaSPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level) 1452c50d8ae3SPaolo Bonzini { 1453f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1454c50d8ae3SPaolo Bonzini } 1455c50d8ae3SPaolo Bonzini 1456c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1457c50d8ae3SPaolo Bonzini /* input fields. */ 1458269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1459c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1460c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1461c50d8ae3SPaolo Bonzini int start_level; 1462c50d8ae3SPaolo Bonzini int end_level; 1463c50d8ae3SPaolo Bonzini 1464c50d8ae3SPaolo Bonzini /* output fields. */ 1465c50d8ae3SPaolo Bonzini gfn_t gfn; 1466c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1467c50d8ae3SPaolo Bonzini int level; 1468c50d8ae3SPaolo Bonzini 1469c50d8ae3SPaolo Bonzini /* private field. */ 1470c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1471c50d8ae3SPaolo Bonzini }; 1472c50d8ae3SPaolo Bonzini 1473f3d90f90SSean Christopherson static void rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, 1474f3d90f90SSean Christopherson int level) 1475c50d8ae3SPaolo Bonzini { 1476c50d8ae3SPaolo Bonzini iterator->level = level; 1477c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 147893e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 147993e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1480c50d8ae3SPaolo Bonzini } 1481c50d8ae3SPaolo Bonzini 1482f3d90f90SSean Christopherson static void slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1483f3d90f90SSean Christopherson const struct kvm_memory_slot *slot, 1484f3d90f90SSean Christopherson int start_level, int end_level, 1485f3d90f90SSean Christopherson gfn_t start_gfn, gfn_t end_gfn) 1486c50d8ae3SPaolo Bonzini { 1487c50d8ae3SPaolo Bonzini iterator->slot = slot; 1488c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1489c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1490c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1491c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1492c50d8ae3SPaolo Bonzini 1493c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1494c50d8ae3SPaolo Bonzini } 1495c50d8ae3SPaolo Bonzini 1496c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1497c50d8ae3SPaolo Bonzini { 1498c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1499c50d8ae3SPaolo Bonzini } 1500c50d8ae3SPaolo Bonzini 1501c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1502c50d8ae3SPaolo Bonzini { 15036ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1504c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 15056ba1e04fSVipin Sharma 15066ba1e04fSVipin Sharma if (iterator->rmap->val) 1507c50d8ae3SPaolo Bonzini return; 1508c50d8ae3SPaolo Bonzini } 1509c50d8ae3SPaolo Bonzini 1510c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1511c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1512c50d8ae3SPaolo Bonzini return; 1513c50d8ae3SPaolo Bonzini } 1514c50d8ae3SPaolo Bonzini 1515c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1516c50d8ae3SPaolo Bonzini } 1517c50d8ae3SPaolo Bonzini 1518c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1519c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1520c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1521c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1522c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1523c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1524c50d8ae3SPaolo Bonzini 15253039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1526c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 1527f3b65bbaSPaolo Bonzini int level); 1528c1b91493SSean Christopherson 15293039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15303039bcc7SSean Christopherson struct kvm_gfn_range *range, 1531c1b91493SSean Christopherson rmap_handler_t handler) 1532c50d8ae3SPaolo Bonzini { 1533c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15343039bcc7SSean Christopherson bool ret = false; 1535c50d8ae3SPaolo Bonzini 15363039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15373039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15383039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 1539f3b65bbaSPaolo Bonzini iterator.level); 1540c50d8ae3SPaolo Bonzini 1541c50d8ae3SPaolo Bonzini return ret; 1542c50d8ae3SPaolo Bonzini } 1543c50d8ae3SPaolo Bonzini 15443039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1545c50d8ae3SPaolo Bonzini { 1546e2209710SBen Gardon bool flush = false; 1547c50d8ae3SPaolo Bonzini 1548e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1549f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1550063afacdSBen Gardon 15511f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1552c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1553063afacdSBen Gardon 15540a3869e1SSean Christopherson if (kvm_x86_ops.set_apic_access_page_addr && 15550a3869e1SSean Christopherson range->slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT) 15560a8a5f2cSSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); 15570a8a5f2cSSean Christopherson 15583039bcc7SSean Christopherson return flush; 1559c50d8ae3SPaolo Bonzini } 1560c50d8ae3SPaolo Bonzini 1561aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1562f3b65bbaSPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level) 1563c50d8ae3SPaolo Bonzini { 1564c50d8ae3SPaolo Bonzini u64 *sptep; 15653f649ab7SKees Cook struct rmap_iterator iter; 1566c50d8ae3SPaolo Bonzini int young = 0; 1567c50d8ae3SPaolo Bonzini 1568c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1569c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1570c50d8ae3SPaolo Bonzini 1571c50d8ae3SPaolo Bonzini return young; 1572c50d8ae3SPaolo Bonzini } 1573c50d8ae3SPaolo Bonzini 1574aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1575f3b65bbaSPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level) 1576c50d8ae3SPaolo Bonzini { 1577c50d8ae3SPaolo Bonzini u64 *sptep; 1578c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1579c50d8ae3SPaolo Bonzini 1580c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1581c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 158298a26b69SVihas Mak return true; 158398a26b69SVihas Mak return false; 1584c50d8ae3SPaolo Bonzini } 1585c50d8ae3SPaolo Bonzini 1586c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1587c50d8ae3SPaolo Bonzini 15882ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 15892ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 15902ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 159172ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1592c50d8ae3SPaolo Bonzini { 1593c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 159468be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 159568be1306SDavid Matlack int rmap_count; 1596c50d8ae3SPaolo Bonzini 159757354682SSean Christopherson sp = sptep_to_sp(spte); 159879e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 159981cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 160081cb4657SDavid Matlack 160193e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 16022ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1603c50d8ae3SPaolo Bonzini 1604604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1605604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 160668be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16079202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 16081b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 160968be1306SDavid Matlack } 1610c50d8ae3SPaolo Bonzini } 1611c50d8ae3SPaolo Bonzini 16122ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 161372ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16142ff9039aSDavid Matlack { 16152ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16162ff9039aSDavid Matlack 16176a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16182ff9039aSDavid Matlack } 16192ff9039aSDavid Matlack 16203039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1621c50d8ae3SPaolo Bonzini { 1622e2209710SBen Gardon bool young = false; 1623f8e14497SBen Gardon 1624e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1625aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16263039bcc7SSean Christopherson 16271f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16283039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1629f8e14497SBen Gardon 1630f8e14497SBen Gardon return young; 1631c50d8ae3SPaolo Bonzini } 1632c50d8ae3SPaolo Bonzini 16333039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1634c50d8ae3SPaolo Bonzini { 1635e2209710SBen Gardon bool young = false; 1636f8e14497SBen Gardon 1637e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1638aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 16393039bcc7SSean Christopherson 16401f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16413039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1642f8e14497SBen Gardon 1643f8e14497SBen Gardon return young; 1644c50d8ae3SPaolo Bonzini } 1645c50d8ae3SPaolo Bonzini 164658da926cSSean Christopherson static void kvm_mmu_check_sptes_at_free(struct kvm_mmu_page *sp) 1647c50d8ae3SPaolo Bonzini { 1648870d4d4eSSean Christopherson #ifdef CONFIG_KVM_PROVE_MMU 1649242a6dd8SSean Christopherson int i; 1650c50d8ae3SPaolo Bonzini 1651242a6dd8SSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 16520fe6370eSSean Christopherson if (KVM_MMU_WARN_ON(is_shadow_present_pte(sp->spt[i]))) 165358da926cSSean Christopherson pr_err_ratelimited("SPTE %llx (@ %p) for gfn %llx shadow-present at free", 165458da926cSSean Christopherson sp->spt[i], &sp->spt[i], 165558da926cSSean Christopherson kvm_mmu_page_get_gfn(sp, i)); 1656c50d8ae3SPaolo Bonzini } 1657c50d8ae3SPaolo Bonzini #endif 165858da926cSSean Christopherson } 1659c50d8ae3SPaolo Bonzini 1660c50d8ae3SPaolo Bonzini /* 1661c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1662c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1663c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1664c50d8ae3SPaolo Bonzini * faster 1665c50d8ae3SPaolo Bonzini */ 1666d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1667c50d8ae3SPaolo Bonzini { 1668c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1669c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1670c50d8ae3SPaolo Bonzini } 1671c50d8ae3SPaolo Bonzini 167243a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 167343a063caSYosry Ahmed { 167443a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 167543a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 167643a063caSYosry Ahmed } 167743a063caSYosry Ahmed 167843a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 167943a063caSYosry Ahmed { 168043a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 168143a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 168243a063caSYosry Ahmed } 168343a063caSYosry Ahmed 168487654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1685c50d8ae3SPaolo Bonzini { 168658da926cSSean Christopherson kvm_mmu_check_sptes_at_free(sp); 168758da926cSSean Christopherson 1688c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1689c50d8ae3SPaolo Bonzini list_del(&sp->link); 1690c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1691c50d8ae3SPaolo Bonzini if (!sp->role.direct) 16926a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1693c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1694c50d8ae3SPaolo Bonzini } 1695c50d8ae3SPaolo Bonzini 1696c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1697c50d8ae3SPaolo Bonzini { 1698c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1699c50d8ae3SPaolo Bonzini } 1700c50d8ae3SPaolo Bonzini 17012ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1702c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1703c50d8ae3SPaolo Bonzini { 1704c50d8ae3SPaolo Bonzini if (!parent_pte) 1705c50d8ae3SPaolo Bonzini return; 1706c50d8ae3SPaolo Bonzini 17072ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1708c50d8ae3SPaolo Bonzini } 1709c50d8ae3SPaolo Bonzini 1710069f30c6SMingwei Zhang static void mmu_page_remove_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 1711c50d8ae3SPaolo Bonzini u64 *parent_pte) 1712c50d8ae3SPaolo Bonzini { 1713069f30c6SMingwei Zhang pte_list_remove(kvm, parent_pte, &sp->parent_ptes); 1714c50d8ae3SPaolo Bonzini } 1715c50d8ae3SPaolo Bonzini 1716069f30c6SMingwei Zhang static void drop_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 1717c50d8ae3SPaolo Bonzini u64 *parent_pte) 1718c50d8ae3SPaolo Bonzini { 1719069f30c6SMingwei Zhang mmu_page_remove_parent_pte(kvm, sp, parent_pte); 1720c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1721c50d8ae3SPaolo Bonzini } 1722c50d8ae3SPaolo Bonzini 1723c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1724c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1725c50d8ae3SPaolo Bonzini { 1726c50d8ae3SPaolo Bonzini u64 *sptep; 1727c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1728c50d8ae3SPaolo Bonzini 1729c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1730c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1731c50d8ae3SPaolo Bonzini } 1732c50d8ae3SPaolo Bonzini } 1733c50d8ae3SPaolo Bonzini 1734c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1735c50d8ae3SPaolo Bonzini { 1736c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1737c50d8ae3SPaolo Bonzini 173857354682SSean Christopherson sp = sptep_to_sp(spte); 173979e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1740c50d8ae3SPaolo Bonzini return; 1741c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1742c50d8ae3SPaolo Bonzini return; 1743c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1744c50d8ae3SPaolo Bonzini } 1745c50d8ae3SPaolo Bonzini 1746c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1747c50d8ae3SPaolo Bonzini 1748c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1749c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1750c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1751c50d8ae3SPaolo Bonzini unsigned int idx; 1752c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1753c50d8ae3SPaolo Bonzini unsigned int nr; 1754c50d8ae3SPaolo Bonzini }; 1755c50d8ae3SPaolo Bonzini 1756c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1757c50d8ae3SPaolo Bonzini int idx) 1758c50d8ae3SPaolo Bonzini { 1759c50d8ae3SPaolo Bonzini int i; 1760c50d8ae3SPaolo Bonzini 1761c50d8ae3SPaolo Bonzini if (sp->unsync) 1762c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1763c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1764c50d8ae3SPaolo Bonzini return 0; 1765c50d8ae3SPaolo Bonzini 1766c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1767c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1768c50d8ae3SPaolo Bonzini pvec->nr++; 1769c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1770c50d8ae3SPaolo Bonzini } 1771c50d8ae3SPaolo Bonzini 1772c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1773c50d8ae3SPaolo Bonzini { 1774c50d8ae3SPaolo Bonzini --sp->unsync_children; 177520ba462dSSean Christopherson WARN_ON_ONCE((int)sp->unsync_children < 0); 1776c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1777c50d8ae3SPaolo Bonzini } 1778c50d8ae3SPaolo Bonzini 1779c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1780c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1781c50d8ae3SPaolo Bonzini { 1782c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1783c50d8ae3SPaolo Bonzini 1784c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1785c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1786c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1787c50d8ae3SPaolo Bonzini 1788c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1789c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1790c50d8ae3SPaolo Bonzini continue; 1791c50d8ae3SPaolo Bonzini } 1792c50d8ae3SPaolo Bonzini 17935e3edd7eSSean Christopherson child = spte_to_child_sp(ent); 1794c50d8ae3SPaolo Bonzini 1795c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1796c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1797c50d8ae3SPaolo Bonzini return -ENOSPC; 1798c50d8ae3SPaolo Bonzini 1799c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1800c50d8ae3SPaolo Bonzini if (!ret) { 1801c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1802c50d8ae3SPaolo Bonzini continue; 1803c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1804c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1805c50d8ae3SPaolo Bonzini } else 1806c50d8ae3SPaolo Bonzini return ret; 1807c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1808c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1809c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1810c50d8ae3SPaolo Bonzini return -ENOSPC; 1811c50d8ae3SPaolo Bonzini } else 1812c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1813c50d8ae3SPaolo Bonzini } 1814c50d8ae3SPaolo Bonzini 1815c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1816c50d8ae3SPaolo Bonzini } 1817c50d8ae3SPaolo Bonzini 1818c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1819c50d8ae3SPaolo Bonzini 1820c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1821c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1822c50d8ae3SPaolo Bonzini { 1823c50d8ae3SPaolo Bonzini pvec->nr = 0; 1824c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1825c50d8ae3SPaolo Bonzini return 0; 1826c50d8ae3SPaolo Bonzini 1827c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1828c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1829c50d8ae3SPaolo Bonzini } 1830c50d8ae3SPaolo Bonzini 1831c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1832c50d8ae3SPaolo Bonzini { 183320ba462dSSean Christopherson WARN_ON_ONCE(!sp->unsync); 1834c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1835c50d8ae3SPaolo Bonzini sp->unsync = 0; 1836c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1837c50d8ae3SPaolo Bonzini } 1838c50d8ae3SPaolo Bonzini 1839c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1840c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1841c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1842c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1843c50d8ae3SPaolo Bonzini 1844767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1845767d8d8dSLai Jiangshan { 1846767d8d8dSLai Jiangshan if (sp->role.direct) 1847767d8d8dSLai Jiangshan return false; 1848767d8d8dSLai Jiangshan 184984e5ffd0SLai Jiangshan if (sp->role.passthrough) 185084e5ffd0SLai Jiangshan return false; 185184e5ffd0SLai Jiangshan 1852767d8d8dSLai Jiangshan return true; 1853767d8d8dSLai Jiangshan } 1854767d8d8dSLai Jiangshan 1855ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1856ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1857c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1858c50d8ae3SPaolo Bonzini } else 1859c50d8ae3SPaolo Bonzini 1860767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1861ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1862ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1863767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1864c50d8ae3SPaolo Bonzini 186590e44470SLai Jiangshan static bool kvm_sync_page_check(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 186690e44470SLai Jiangshan { 186790e44470SLai Jiangshan union kvm_mmu_page_role root_role = vcpu->arch.mmu->root_role; 186890e44470SLai Jiangshan 186990e44470SLai Jiangshan /* 187090e44470SLai Jiangshan * Ignore various flags when verifying that it's safe to sync a shadow 187190e44470SLai Jiangshan * page using the current MMU context. 187290e44470SLai Jiangshan * 187390e44470SLai Jiangshan * - level: not part of the overall MMU role and will never match as the MMU's 187490e44470SLai Jiangshan * level tracks the root level 187590e44470SLai Jiangshan * - access: updated based on the new guest PTE 187690e44470SLai Jiangshan * - quadrant: not part of the overall MMU role (similar to level) 187790e44470SLai Jiangshan */ 187890e44470SLai Jiangshan const union kvm_mmu_page_role sync_role_ign = { 187990e44470SLai Jiangshan .level = 0xf, 188090e44470SLai Jiangshan .access = 0x7, 188190e44470SLai Jiangshan .quadrant = 0x3, 188290e44470SLai Jiangshan .passthrough = 0x1, 188390e44470SLai Jiangshan }; 188490e44470SLai Jiangshan 188590e44470SLai Jiangshan /* 188690e44470SLai Jiangshan * Direct pages can never be unsync, and KVM should never attempt to 188790e44470SLai Jiangshan * sync a shadow page for a different MMU context, e.g. if the role 188890e44470SLai Jiangshan * differs then the memslot lookup (SMM vs. non-SMM) will be bogus, the 188990e44470SLai Jiangshan * reserved bits checks will be wrong, etc... 189090e44470SLai Jiangshan */ 1891c3c6c9fcSLai Jiangshan if (WARN_ON_ONCE(sp->role.direct || !vcpu->arch.mmu->sync_spte || 189290e44470SLai Jiangshan (sp->role.word ^ root_role.word) & ~sync_role_ign.word)) 189390e44470SLai Jiangshan return false; 189490e44470SLai Jiangshan 189590e44470SLai Jiangshan return true; 189690e44470SLai Jiangshan } 189790e44470SLai Jiangshan 189819ace7d6SLai Jiangshan static int kvm_sync_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int i) 189919ace7d6SLai Jiangshan { 190019ace7d6SLai Jiangshan if (!sp->spt[i]) 190119ace7d6SLai Jiangshan return 0; 190219ace7d6SLai Jiangshan 190319ace7d6SLai Jiangshan return vcpu->arch.mmu->sync_spte(vcpu, sp, i); 190419ace7d6SLai Jiangshan } 190519ace7d6SLai Jiangshan 190690e44470SLai Jiangshan static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 190790e44470SLai Jiangshan { 1908c3c6c9fcSLai Jiangshan int flush = 0; 1909c3c6c9fcSLai Jiangshan int i; 1910c3c6c9fcSLai Jiangshan 191190e44470SLai Jiangshan if (!kvm_sync_page_check(vcpu, sp)) 191290e44470SLai Jiangshan return -1; 191390e44470SLai Jiangshan 1914c3c6c9fcSLai Jiangshan for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 191519ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, i); 1916c3c6c9fcSLai Jiangshan 1917c3c6c9fcSLai Jiangshan if (ret < -1) 1918c3c6c9fcSLai Jiangshan return -1; 1919c3c6c9fcSLai Jiangshan flush |= ret; 1920c3c6c9fcSLai Jiangshan } 1921c3c6c9fcSLai Jiangshan 1922c3c6c9fcSLai Jiangshan /* 1923c3c6c9fcSLai Jiangshan * Note, any flush is purely for KVM's correctness, e.g. when dropping 1924c3c6c9fcSLai Jiangshan * an existing SPTE or clearing W/A/D bits to ensure an mmu_notifier 1925c3c6c9fcSLai Jiangshan * unmap or dirty logging event doesn't fail to flush. The guest is 1926c3c6c9fcSLai Jiangshan * responsible for flushing the TLB to ensure any changes in protection 1927c3c6c9fcSLai Jiangshan * bits are recognized, i.e. until the guest flushes or page faults on 1928c3c6c9fcSLai Jiangshan * a relevant address, KVM is architecturally allowed to let vCPUs use 1929c3c6c9fcSLai Jiangshan * cached translations with the old protection bits. 1930c3c6c9fcSLai Jiangshan */ 1931c3c6c9fcSLai Jiangshan return flush; 193290e44470SLai Jiangshan } 193390e44470SLai Jiangshan 19348d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1935c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1936c50d8ae3SPaolo Bonzini { 193790e44470SLai Jiangshan int ret = __kvm_sync_page(vcpu, sp); 1938c3e5e415SLai Jiangshan 19398d5678a7SHou Wenlong if (ret < 0) 1940c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 19418d5678a7SHou Wenlong return ret; 1942c50d8ae3SPaolo Bonzini } 1943c50d8ae3SPaolo Bonzini 1944c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1945c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1946c50d8ae3SPaolo Bonzini bool remote_flush) 1947c50d8ae3SPaolo Bonzini { 1948c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1949c50d8ae3SPaolo Bonzini return false; 1950c50d8ae3SPaolo Bonzini 1951c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1952c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1953c50d8ae3SPaolo Bonzini else 1954c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1955c50d8ae3SPaolo Bonzini return true; 1956c50d8ae3SPaolo Bonzini } 1957c50d8ae3SPaolo Bonzini 1958c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1959c50d8ae3SPaolo Bonzini { 1960a955cad8SSean Christopherson if (sp->role.invalid) 1961a955cad8SSean Christopherson return true; 1962a955cad8SSean Christopherson 1963fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 1964de0322f5SSean Christopherson return !is_tdp_mmu_page(sp) && 1965c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1966c50d8ae3SPaolo Bonzini } 1967c50d8ae3SPaolo Bonzini 1968c50d8ae3SPaolo Bonzini struct mmu_page_path { 1969c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1970c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1971c50d8ae3SPaolo Bonzini }; 1972c50d8ae3SPaolo Bonzini 1973c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1974c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1975c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1976c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1977c50d8ae3SPaolo Bonzini 1978c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1979c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1980c50d8ae3SPaolo Bonzini int i) 1981c50d8ae3SPaolo Bonzini { 1982c50d8ae3SPaolo Bonzini int n; 1983c50d8ae3SPaolo Bonzini 1984c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1985c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1986c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1987c50d8ae3SPaolo Bonzini int level = sp->role.level; 1988c50d8ae3SPaolo Bonzini 1989c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19903bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1991c50d8ae3SPaolo Bonzini break; 1992c50d8ae3SPaolo Bonzini 1993c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1994c50d8ae3SPaolo Bonzini } 1995c50d8ae3SPaolo Bonzini 1996c50d8ae3SPaolo Bonzini return n; 1997c50d8ae3SPaolo Bonzini } 1998c50d8ae3SPaolo Bonzini 1999c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 2000c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 2001c50d8ae3SPaolo Bonzini { 2002c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2003c50d8ae3SPaolo Bonzini int level; 2004c50d8ae3SPaolo Bonzini 2005c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 2006c50d8ae3SPaolo Bonzini return 0; 2007c50d8ae3SPaolo Bonzini 200820ba462dSSean Christopherson WARN_ON_ONCE(pvec->page[0].idx != INVALID_INDEX); 2009c50d8ae3SPaolo Bonzini 2010c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 2011c50d8ae3SPaolo Bonzini level = sp->role.level; 201220ba462dSSean Christopherson WARN_ON_ONCE(level == PG_LEVEL_4K); 2013c50d8ae3SPaolo Bonzini 2014c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2015c50d8ae3SPaolo Bonzini 2016c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 2017c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 2018c50d8ae3SPaolo Bonzini */ 2019c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 2020c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 2021c50d8ae3SPaolo Bonzini } 2022c50d8ae3SPaolo Bonzini 2023c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 2024c50d8ae3SPaolo Bonzini { 2025c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2026c50d8ae3SPaolo Bonzini unsigned int level = 0; 2027c50d8ae3SPaolo Bonzini 2028c50d8ae3SPaolo Bonzini do { 2029c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 2030c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 2031c50d8ae3SPaolo Bonzini if (!sp) 2032c50d8ae3SPaolo Bonzini return; 2033c50d8ae3SPaolo Bonzini 203420ba462dSSean Christopherson WARN_ON_ONCE(idx == INVALID_INDEX); 2035c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 2036c50d8ae3SPaolo Bonzini level++; 2037c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 2038c50d8ae3SPaolo Bonzini } 2039c50d8ae3SPaolo Bonzini 204065855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 204165855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 2042c50d8ae3SPaolo Bonzini { 2043c50d8ae3SPaolo Bonzini int i; 2044c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2045c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2046c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2047c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2048c50d8ae3SPaolo Bonzini bool flush = false; 2049c50d8ae3SPaolo Bonzini 2050c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2051c50d8ae3SPaolo Bonzini bool protected = false; 2052c50d8ae3SPaolo Bonzini 2053c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 2054cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 2055c50d8ae3SPaolo Bonzini 2056c50d8ae3SPaolo Bonzini if (protected) { 20575591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 2058c50d8ae3SPaolo Bonzini flush = false; 2059c50d8ae3SPaolo Bonzini } 2060c50d8ae3SPaolo Bonzini 2061c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2062479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 20638d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 2064c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2065c50d8ae3SPaolo Bonzini } 2066531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2067c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 206865855ed8SLai Jiangshan if (!can_yield) { 206965855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 207065855ed8SLai Jiangshan return -EINTR; 207165855ed8SLai Jiangshan } 207265855ed8SLai Jiangshan 2073531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2074c50d8ae3SPaolo Bonzini flush = false; 2075c50d8ae3SPaolo Bonzini } 2076c50d8ae3SPaolo Bonzini } 2077c50d8ae3SPaolo Bonzini 2078c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 207965855ed8SLai Jiangshan return 0; 2080c50d8ae3SPaolo Bonzini } 2081c50d8ae3SPaolo Bonzini 2082c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2083c50d8ae3SPaolo Bonzini { 2084c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2085c50d8ae3SPaolo Bonzini } 2086c50d8ae3SPaolo Bonzini 2087c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2088c50d8ae3SPaolo Bonzini { 208957354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2090c50d8ae3SPaolo Bonzini } 2091c50d8ae3SPaolo Bonzini 2092cbd858b1SDavid Matlack /* 2093cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2094cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2095cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2096cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2097cbd858b1SDavid Matlack */ 20983cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 20993cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 210094c81364SDavid Matlack gfn_t gfn, 210194c81364SDavid Matlack struct hlist_head *sp_list, 21022e65e842SDavid Matlack union kvm_mmu_page_role role) 2103c50d8ae3SPaolo Bonzini { 2104c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 21058d5678a7SHou Wenlong int ret; 2106c50d8ae3SPaolo Bonzini int collisions = 0; 2107c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2108c50d8ae3SPaolo Bonzini 21093cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2110c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2111c50d8ae3SPaolo Bonzini collisions++; 2112c50d8ae3SPaolo Bonzini continue; 2113c50d8ae3SPaolo Bonzini } 2114c50d8ae3SPaolo Bonzini 2115ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2116ddc16abbSSean Christopherson /* 2117ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2118ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2119ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2120ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2121ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2122ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2123ddc16abbSSean Christopherson * upper-level page will be write-protected. 2124ddc16abbSSean Christopherson */ 21252e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 21263cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2127ddc16abbSSean Christopherson &invalid_list); 2128c50d8ae3SPaolo Bonzini continue; 2129ddc16abbSSean Christopherson } 2130c50d8ae3SPaolo Bonzini 2131bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2132bb924ca6SDavid Matlack if (sp->role.direct) 213394c81364SDavid Matlack goto out; 2134fb58a9c3SSean Christopherson 2135c50d8ae3SPaolo Bonzini if (sp->unsync) { 2136cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2137cbd858b1SDavid Matlack break; 2138cbd858b1SDavid Matlack 213907dc4f35SSean Christopherson /* 2140479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 214107dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 214207dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 214307dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 214407dc4f35SSean Christopherson * overhead of write protection is not incurred until the 214507dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 214607dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 214707dc4f35SSean Christopherson * 214807dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 214907dc4f35SSean Christopherson * in order to rebuild it. 2150c50d8ae3SPaolo Bonzini */ 21518d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 21528d5678a7SHou Wenlong if (ret < 0) 2153c50d8ae3SPaolo Bonzini break; 2154c50d8ae3SPaolo Bonzini 215520ba462dSSean Christopherson WARN_ON_ONCE(!list_empty(&invalid_list)); 21568d5678a7SHou Wenlong if (ret > 0) 21573cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2158c50d8ae3SPaolo Bonzini } 2159c50d8ae3SPaolo Bonzini 2160c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2161fb58a9c3SSean Christopherson 2162c50d8ae3SPaolo Bonzini goto out; 2163c50d8ae3SPaolo Bonzini } 2164c50d8ae3SPaolo Bonzini 216594c81364SDavid Matlack sp = NULL; 21663cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2167c50d8ae3SPaolo Bonzini 216894c81364SDavid Matlack out: 21693cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 217094c81364SDavid Matlack 21713cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 21723cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 217394c81364SDavid Matlack return sp; 217494c81364SDavid Matlack } 217594c81364SDavid Matlack 21762f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 21772f8b1b53SDavid Matlack struct shadow_page_caches { 21782f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 21792f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 21806a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 21812f8b1b53SDavid Matlack }; 21822f8b1b53SDavid Matlack 2183336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 21842f8b1b53SDavid Matlack struct shadow_page_caches *caches, 218594c81364SDavid Matlack gfn_t gfn, 218694c81364SDavid Matlack struct hlist_head *sp_list, 218794c81364SDavid Matlack union kvm_mmu_page_role role) 218894c81364SDavid Matlack { 2189c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2190c306aec8SDavid Matlack 21912f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 21922f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2193c306aec8SDavid Matlack if (!role.direct) 21946a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2195c306aec8SDavid Matlack 2196c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2197c306aec8SDavid Matlack 219855c510e2SSean Christopherson INIT_LIST_HEAD(&sp->possible_nx_huge_page_link); 2199428e9216SSean Christopherson 2200c306aec8SDavid Matlack /* 2201c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2202c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2203c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2204c306aec8SDavid Matlack */ 2205336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2206336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 220743a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2208c50d8ae3SPaolo Bonzini 2209c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2210c50d8ae3SPaolo Bonzini sp->role = role; 2211ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2212be911771SDavid Matlack if (sp_has_gptes(sp)) 2213336081fbSDavid Matlack account_shadowed(kvm, sp); 2214ddc16abbSSean Christopherson 221594c81364SDavid Matlack return sp; 221694c81364SDavid Matlack } 221794c81364SDavid Matlack 2218cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 22193cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 22203cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 22212f8b1b53SDavid Matlack struct shadow_page_caches *caches, 222287654643SDavid Matlack gfn_t gfn, 222394c81364SDavid Matlack union kvm_mmu_page_role role) 222494c81364SDavid Matlack { 222594c81364SDavid Matlack struct hlist_head *sp_list; 222694c81364SDavid Matlack struct kvm_mmu_page *sp; 222794c81364SDavid Matlack bool created = false; 222894c81364SDavid Matlack 22293cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 223094c81364SDavid Matlack 22313cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 223294c81364SDavid Matlack if (!sp) { 223394c81364SDavid Matlack created = true; 22343cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 223594c81364SDavid Matlack } 223694c81364SDavid Matlack 223794c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2238c50d8ae3SPaolo Bonzini return sp; 2239c50d8ae3SPaolo Bonzini } 2240c50d8ae3SPaolo Bonzini 22412f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 22422f8b1b53SDavid Matlack gfn_t gfn, 22432f8b1b53SDavid Matlack union kvm_mmu_page_role role) 22442f8b1b53SDavid Matlack { 22452f8b1b53SDavid Matlack struct shadow_page_caches caches = { 22462f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 22472f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 22486a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 22492f8b1b53SDavid Matlack }; 22502f8b1b53SDavid Matlack 22513cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 22522f8b1b53SDavid Matlack } 22532f8b1b53SDavid Matlack 225439944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 225539944ab9SSean Christopherson unsigned int access) 22562e65e842SDavid Matlack { 22572e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 22582e65e842SDavid Matlack union kvm_mmu_page_role role; 22592e65e842SDavid Matlack 22602e65e842SDavid Matlack role = parent_sp->role; 22612e65e842SDavid Matlack role.level--; 22622e65e842SDavid Matlack role.access = access; 22632e65e842SDavid Matlack role.direct = direct; 22642e65e842SDavid Matlack role.passthrough = 0; 22652e65e842SDavid Matlack 22662e65e842SDavid Matlack /* 22672e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 22682e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 22692e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 22702e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 22712e65e842SDavid Matlack * requires extra bookkeeping in the role. 22722e65e842SDavid Matlack * 22732e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 22742e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 22752e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 22762e65e842SDavid Matlack * the address space each maps. 22772e65e842SDavid Matlack * 22782e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 22792e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 22802e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 22812e65e842SDavid Matlack * 228239944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 228339944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 228439944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 228539944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 228639944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 228739944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 228839944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 228939944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 229039944ab9SSean Christopherson * _least_ significant bit of the PDE index. 22912e65e842SDavid Matlack */ 22922e65e842SDavid Matlack if (role.has_4_byte_gpte) { 22932e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 229479e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 22952e65e842SDavid Matlack } 22962e65e842SDavid Matlack 22972e65e842SDavid Matlack return role; 22982e65e842SDavid Matlack } 22992e65e842SDavid Matlack 23002e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 23012e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 23022e65e842SDavid Matlack bool direct, unsigned int access) 23032e65e842SDavid Matlack { 23042e65e842SDavid Matlack union kvm_mmu_page_role role; 23052e65e842SDavid Matlack 23060cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 23070cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 23080cd8dc73SPaolo Bonzini 23092e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 231087654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 23112e65e842SDavid Matlack } 23122e65e842SDavid Matlack 2313c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2314c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2315c50d8ae3SPaolo Bonzini u64 addr) 2316c50d8ae3SPaolo Bonzini { 2317c50d8ae3SPaolo Bonzini iterator->addr = addr; 2318c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2319a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2320c50d8ae3SPaolo Bonzini 232112ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 23224d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2323347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 232412ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2325c50d8ae3SPaolo Bonzini 2326c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2327c50d8ae3SPaolo Bonzini /* 2328c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2329c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2330c50d8ae3SPaolo Bonzini */ 2331b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2332c50d8ae3SPaolo Bonzini 2333c50d8ae3SPaolo Bonzini iterator->shadow_addr 2334c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 23352ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2336c50d8ae3SPaolo Bonzini --iterator->level; 2337c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2338c50d8ae3SPaolo Bonzini iterator->level = 0; 2339c50d8ae3SPaolo Bonzini } 2340c50d8ae3SPaolo Bonzini } 2341c50d8ae3SPaolo Bonzini 2342c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2343c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2344c50d8ae3SPaolo Bonzini { 2345b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2346c50d8ae3SPaolo Bonzini addr); 2347c50d8ae3SPaolo Bonzini } 2348c50d8ae3SPaolo Bonzini 2349c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2350c50d8ae3SPaolo Bonzini { 23513bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2352c50d8ae3SPaolo Bonzini return false; 2353c50d8ae3SPaolo Bonzini 23542ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2355c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2356c50d8ae3SPaolo Bonzini return true; 2357c50d8ae3SPaolo Bonzini } 2358c50d8ae3SPaolo Bonzini 2359c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2360c50d8ae3SPaolo Bonzini u64 spte) 2361c50d8ae3SPaolo Bonzini { 23623e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2363c50d8ae3SPaolo Bonzini iterator->level = 0; 2364c50d8ae3SPaolo Bonzini return; 2365c50d8ae3SPaolo Bonzini } 2366c50d8ae3SPaolo Bonzini 23672ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2368c50d8ae3SPaolo Bonzini --iterator->level; 2369c50d8ae3SPaolo Bonzini } 2370c50d8ae3SPaolo Bonzini 2371c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2372c50d8ae3SPaolo Bonzini { 2373c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2374c50d8ae3SPaolo Bonzini } 2375c50d8ae3SPaolo Bonzini 23760cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 23770cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 237803787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2379c50d8ae3SPaolo Bonzini { 2380c50d8ae3SPaolo Bonzini u64 spte; 2381c50d8ae3SPaolo Bonzini 2382c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2383c50d8ae3SPaolo Bonzini 23840cd8dc73SPaolo Bonzini /* 23850cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 238603787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 238703787394SPaolo Bonzini * installing sp. 23880cd8dc73SPaolo Bonzini */ 23890cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 239003787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 23910cd8dc73SPaolo Bonzini 2392cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2393c50d8ae3SPaolo Bonzini 2394c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2395c50d8ae3SPaolo Bonzini 23962ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2397c50d8ae3SPaolo Bonzini 2398c4a48868SLai Jiangshan /* 2399c4a48868SLai Jiangshan * The non-direct sub-pagetable must be updated before linking. For 2400c4a48868SLai Jiangshan * L1 sp, the pagetable is updated via kvm_sync_page() in 2401c4a48868SLai Jiangshan * kvm_mmu_find_shadow_page() without write-protecting the gfn, 2402c4a48868SLai Jiangshan * so sp->unsync can be true or false. For higher level non-direct 2403c4a48868SLai Jiangshan * sp, the pagetable is updated/synced via mmu_sync_children() in 2404c4a48868SLai Jiangshan * FNAME(fetch)(), so sp->unsync_children can only be false. 2405c4a48868SLai Jiangshan * WARN_ON_ONCE() if anything happens unexpectedly. 2406c4a48868SLai Jiangshan */ 2407c4a48868SLai Jiangshan if (WARN_ON_ONCE(sp->unsync_children) || sp->unsync) 2408c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2409c50d8ae3SPaolo Bonzini } 2410c50d8ae3SPaolo Bonzini 24112ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 24122ff9039aSDavid Matlack struct kvm_mmu_page *sp) 24132ff9039aSDavid Matlack { 241403787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 24152ff9039aSDavid Matlack } 24162ff9039aSDavid Matlack 2417c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2418c50d8ae3SPaolo Bonzini unsigned direct_access) 2419c50d8ae3SPaolo Bonzini { 2420c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2421c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2422c50d8ae3SPaolo Bonzini 2423c50d8ae3SPaolo Bonzini /* 2424c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2425c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2426c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2427c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2428c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2429c50d8ae3SPaolo Bonzini */ 24305e3edd7eSSean Christopherson child = spte_to_child_sp(*sptep); 2431c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2432c50d8ae3SPaolo Bonzini return; 2433c50d8ae3SPaolo Bonzini 2434069f30c6SMingwei Zhang drop_parent_pte(vcpu->kvm, child, sptep); 24353cdf9374SHou Wenlong kvm_flush_remote_tlbs_sptep(vcpu->kvm, sptep); 2436c50d8ae3SPaolo Bonzini } 2437c50d8ae3SPaolo Bonzini } 2438c50d8ae3SPaolo Bonzini 24392de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 24402de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 24412de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2442c50d8ae3SPaolo Bonzini { 2443c50d8ae3SPaolo Bonzini u64 pte; 2444c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2445c50d8ae3SPaolo Bonzini 2446c50d8ae3SPaolo Bonzini pte = *spte; 2447c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2448c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2449c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2450c50d8ae3SPaolo Bonzini } else { 24515e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2452069f30c6SMingwei Zhang drop_parent_pte(kvm, child, spte); 24532de4085cSBen Gardon 24542de4085cSBen Gardon /* 24552de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 24562de4085cSBen Gardon * unlikely to be used again in the near future. This 24572de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 24582de4085cSBen Gardon */ 24592de4085cSBen Gardon if (tdp_enabled && invalid_list && 24602de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 24612de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 24622de4085cSBen Gardon invalid_list); 2463c50d8ae3SPaolo Bonzini } 2464ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2465c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2466ace569e0SSean Christopherson } 24672de4085cSBen Gardon return 0; 2468c50d8ae3SPaolo Bonzini } 2469c50d8ae3SPaolo Bonzini 24702de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 24712de4085cSBen Gardon struct kvm_mmu_page *sp, 24722de4085cSBen Gardon struct list_head *invalid_list) 2473c50d8ae3SPaolo Bonzini { 24742de4085cSBen Gardon int zapped = 0; 2475c50d8ae3SPaolo Bonzini unsigned i; 2476c50d8ae3SPaolo Bonzini 24772ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 24782de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 24792de4085cSBen Gardon 24802de4085cSBen Gardon return zapped; 2481c50d8ae3SPaolo Bonzini } 2482c50d8ae3SPaolo Bonzini 2483069f30c6SMingwei Zhang static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) 2484c50d8ae3SPaolo Bonzini { 2485c50d8ae3SPaolo Bonzini u64 *sptep; 2486c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2487c50d8ae3SPaolo Bonzini 2488c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2489069f30c6SMingwei Zhang drop_parent_pte(kvm, sp, sptep); 2490c50d8ae3SPaolo Bonzini } 2491c50d8ae3SPaolo Bonzini 2492c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2493c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2494c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2495c50d8ae3SPaolo Bonzini { 2496c50d8ae3SPaolo Bonzini int i, zapped = 0; 2497c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2498c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2499c50d8ae3SPaolo Bonzini 25003bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2501c50d8ae3SPaolo Bonzini return 0; 2502c50d8ae3SPaolo Bonzini 2503c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2504c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2505c50d8ae3SPaolo Bonzini 2506c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2507c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2508c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2509c50d8ae3SPaolo Bonzini zapped++; 2510c50d8ae3SPaolo Bonzini } 2511c50d8ae3SPaolo Bonzini } 2512c50d8ae3SPaolo Bonzini 2513c50d8ae3SPaolo Bonzini return zapped; 2514c50d8ae3SPaolo Bonzini } 2515c50d8ae3SPaolo Bonzini 2516c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2517c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2518c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2519c50d8ae3SPaolo Bonzini int *nr_zapped) 2520c50d8ae3SPaolo Bonzini { 2521527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2522c50d8ae3SPaolo Bonzini 252347b0c2e4SKazuki Takiguchi lockdep_assert_held_write(&kvm->mmu_lock); 2524c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2525c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2526c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 25272de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 2528069f30c6SMingwei Zhang kvm_mmu_unlink_parents(kvm, sp); 2529c50d8ae3SPaolo Bonzini 2530c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2531c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2532c50d8ae3SPaolo Bonzini 2533767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2534c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2535c50d8ae3SPaolo Bonzini 2536c50d8ae3SPaolo Bonzini if (sp->unsync) 2537c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2538c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2539c50d8ae3SPaolo Bonzini /* Count self */ 2540c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2541f95eec9bSSean Christopherson 2542f95eec9bSSean Christopherson /* 2543f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2544f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2545f95eec9bSSean Christopherson * !sp->root_count. 2546f95eec9bSSean Christopherson */ 2547f95eec9bSSean Christopherson if (sp->role.invalid) 2548f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2549f95eec9bSSean Christopherson else 2550c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 255143a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2552c50d8ae3SPaolo Bonzini } else { 2553f95eec9bSSean Christopherson /* 2554f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2555f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2556f95eec9bSSean Christopherson */ 2557f95eec9bSSean Christopherson list_del(&sp->link); 2558c50d8ae3SPaolo Bonzini 2559c50d8ae3SPaolo Bonzini /* 2560c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2561c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2562c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2563c50d8ae3SPaolo Bonzini */ 2564527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2565c50d8ae3SPaolo Bonzini } 2566c50d8ae3SPaolo Bonzini 256755c510e2SSean Christopherson if (sp->nx_huge_page_disallowed) 256855c510e2SSean Christopherson unaccount_nx_huge_page(kvm, sp); 2569c50d8ae3SPaolo Bonzini 2570c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2571527d5cd7SSean Christopherson 2572527d5cd7SSean Christopherson /* 2573527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2574527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2575527d5cd7SSean Christopherson */ 2576527d5cd7SSean Christopherson if (zapped_root) 2577527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2578c50d8ae3SPaolo Bonzini return list_unstable; 2579c50d8ae3SPaolo Bonzini } 2580c50d8ae3SPaolo Bonzini 2581c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2582c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2583c50d8ae3SPaolo Bonzini { 2584c50d8ae3SPaolo Bonzini int nr_zapped; 2585c50d8ae3SPaolo Bonzini 2586c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2587c50d8ae3SPaolo Bonzini return nr_zapped; 2588c50d8ae3SPaolo Bonzini } 2589c50d8ae3SPaolo Bonzini 2590c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2591c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2592c50d8ae3SPaolo Bonzini { 2593c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2594c50d8ae3SPaolo Bonzini 2595c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2596c50d8ae3SPaolo Bonzini return; 2597c50d8ae3SPaolo Bonzini 2598c50d8ae3SPaolo Bonzini /* 2599c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2600c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2601c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2602c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2603c50d8ae3SPaolo Bonzini * 2604c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2605c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2606c50d8ae3SPaolo Bonzini */ 2607c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2608c50d8ae3SPaolo Bonzini 2609c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 261020ba462dSSean Christopherson WARN_ON_ONCE(!sp->role.invalid || sp->root_count); 261187654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2612c50d8ae3SPaolo Bonzini } 2613c50d8ae3SPaolo Bonzini } 2614c50d8ae3SPaolo Bonzini 26156b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 26166b82ef2cSSean Christopherson unsigned long nr_to_zap) 2617c50d8ae3SPaolo Bonzini { 26186b82ef2cSSean Christopherson unsigned long total_zapped = 0; 26196b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2620ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 26216b82ef2cSSean Christopherson bool unstable; 26226b82ef2cSSean Christopherson int nr_zapped; 2623c50d8ae3SPaolo Bonzini 2624c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2625ba7888ddSSean Christopherson return 0; 2626c50d8ae3SPaolo Bonzini 26276b82ef2cSSean Christopherson restart: 26288fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 26296b82ef2cSSean Christopherson /* 26306b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 26316b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 26326b82ef2cSSean Christopherson */ 26336b82ef2cSSean Christopherson if (sp->root_count) 26346b82ef2cSSean Christopherson continue; 26356b82ef2cSSean Christopherson 26366b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 26376b82ef2cSSean Christopherson &nr_zapped); 26386b82ef2cSSean Christopherson total_zapped += nr_zapped; 26396b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2640ba7888ddSSean Christopherson break; 2641ba7888ddSSean Christopherson 26426b82ef2cSSean Christopherson if (unstable) 26436b82ef2cSSean Christopherson goto restart; 2644ba7888ddSSean Christopherson } 26456b82ef2cSSean Christopherson 26466b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 26476b82ef2cSSean Christopherson 26486b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 26496b82ef2cSSean Christopherson return total_zapped; 26506b82ef2cSSean Christopherson } 26516b82ef2cSSean Christopherson 2652afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2653afe8d7e6SSean Christopherson { 2654afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2655afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2656afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2657afe8d7e6SSean Christopherson 2658afe8d7e6SSean Christopherson return 0; 2659c50d8ae3SPaolo Bonzini } 2660c50d8ae3SPaolo Bonzini 2661ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2662ba7888ddSSean Christopherson { 26636b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2664ba7888ddSSean Christopherson 26656b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2666ba7888ddSSean Christopherson return 0; 2667ba7888ddSSean Christopherson 26686b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2669ba7888ddSSean Christopherson 26706e6ec584SSean Christopherson /* 26716e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 26726e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 26736e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 26746e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2675c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 26766e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 26776e6ec584SSean Christopherson * page fault paths. 26786e6ec584SSean Christopherson */ 2679ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2680ba7888ddSSean Christopherson return -ENOSPC; 2681ba7888ddSSean Christopherson return 0; 2682ba7888ddSSean Christopherson } 2683ba7888ddSSean Christopherson 2684c50d8ae3SPaolo Bonzini /* 2685c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2686c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2687c50d8ae3SPaolo Bonzini */ 2688c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2689c50d8ae3SPaolo Bonzini { 2690531810caSBen Gardon write_lock(&kvm->mmu_lock); 2691c50d8ae3SPaolo Bonzini 2692c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 26936b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 26946b82ef2cSSean Christopherson goal_nr_mmu_pages); 2695c50d8ae3SPaolo Bonzini 2696c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2697c50d8ae3SPaolo Bonzini } 2698c50d8ae3SPaolo Bonzini 2699c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2700c50d8ae3SPaolo Bonzini 2701531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2702c50d8ae3SPaolo Bonzini } 2703c50d8ae3SPaolo Bonzini 2704c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2705c50d8ae3SPaolo Bonzini { 2706c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2707c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2708c50d8ae3SPaolo Bonzini int r; 2709c50d8ae3SPaolo Bonzini 2710c50d8ae3SPaolo Bonzini r = 0; 2711531810caSBen Gardon write_lock(&kvm->mmu_lock); 2712767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2713c50d8ae3SPaolo Bonzini r = 1; 2714c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2715c50d8ae3SPaolo Bonzini } 2716c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2717531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2718c50d8ae3SPaolo Bonzini 2719c50d8ae3SPaolo Bonzini return r; 2720c50d8ae3SPaolo Bonzini } 272196ad91aeSSean Christopherson 272296ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 272396ad91aeSSean Christopherson { 272496ad91aeSSean Christopherson gpa_t gpa; 272596ad91aeSSean Christopherson int r; 272696ad91aeSSean Christopherson 2727347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 272896ad91aeSSean Christopherson return 0; 272996ad91aeSSean Christopherson 273096ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 273196ad91aeSSean Christopherson 273296ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 273396ad91aeSSean Christopherson 273496ad91aeSSean Christopherson return r; 273596ad91aeSSean Christopherson } 2736c50d8ae3SPaolo Bonzini 27374d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2738c50d8ae3SPaolo Bonzini { 2739c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 27404d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2741c50d8ae3SPaolo Bonzini sp->unsync = 1; 2742c50d8ae3SPaolo Bonzini 2743c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2744c50d8ae3SPaolo Bonzini } 2745c50d8ae3SPaolo Bonzini 27460337f585SSean Christopherson /* 27470337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 27480337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 27490337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 27500337f585SSean Christopherson * be write-protected. 27510337f585SSean Christopherson */ 27528283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 27532839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2754c50d8ae3SPaolo Bonzini { 2755c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2756ce25681dSSean Christopherson bool locked = false; 2757c50d8ae3SPaolo Bonzini 27580337f585SSean Christopherson /* 27590337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 27600337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 27610337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 27620337f585SSean Christopherson */ 27637b574863SSean Christopherson if (kvm_gfn_is_write_tracked(kvm, slot, gfn)) 27640337f585SSean Christopherson return -EPERM; 2765c50d8ae3SPaolo Bonzini 27660337f585SSean Christopherson /* 27670337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 27680337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 27690337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 27700337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 27710337f585SSean Christopherson */ 2772767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2773c50d8ae3SPaolo Bonzini if (!can_unsync) 27740337f585SSean Christopherson return -EPERM; 2775c50d8ae3SPaolo Bonzini 2776c50d8ae3SPaolo Bonzini if (sp->unsync) 2777c50d8ae3SPaolo Bonzini continue; 2778c50d8ae3SPaolo Bonzini 27792839180cSPaolo Bonzini if (prefetch) 2780f1c4a88cSLai Jiangshan return -EEXIST; 2781f1c4a88cSLai Jiangshan 2782ce25681dSSean Christopherson /* 2783ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2784ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2785ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2786ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2787ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2788ce25681dSSean Christopherson */ 2789ce25681dSSean Christopherson if (!locked) { 2790ce25681dSSean Christopherson locked = true; 27914d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2792ce25681dSSean Christopherson 2793ce25681dSSean Christopherson /* 2794ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2795ce25681dSSean Christopherson * may have since marked the page unsync. A false 2796e59f75deSPaolo Bonzini * negative on the unprotected check above is not 2797ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2798e59f75deSPaolo Bonzini * for write, i.e. unsync cannot transition from 1->0 2799ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2800ce25681dSSean Christopherson */ 2801ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2802ce25681dSSean Christopherson continue; 2803ce25681dSSean Christopherson } 2804ce25681dSSean Christopherson 280520ba462dSSean Christopherson WARN_ON_ONCE(sp->role.level != PG_LEVEL_4K); 28064d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2807c50d8ae3SPaolo Bonzini } 2808ce25681dSSean Christopherson if (locked) 28094d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2810c50d8ae3SPaolo Bonzini 2811c50d8ae3SPaolo Bonzini /* 2812c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2813c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2814c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2815c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2816c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2817c50d8ae3SPaolo Bonzini * following could happen: 2818c50d8ae3SPaolo Bonzini * 2819c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2820c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2821c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2822c50d8ae3SPaolo Bonzini * to be writable 2823c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2824c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2825c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2826c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2827c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2828c50d8ae3SPaolo Bonzini * fault. 2829c50d8ae3SPaolo Bonzini * 2830c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2831c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2832c50d8ae3SPaolo Bonzini * 28330337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 28340337f585SSean Christopherson * false and skips the page. 2835c50d8ae3SPaolo Bonzini * 2836c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2837c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2838c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2839c50d8ae3SPaolo Bonzini * gets used. 2840c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2841c50d8ae3SPaolo Bonzini * as unsync 2842c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2843c50d8ae3SPaolo Bonzini * 2844c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2845264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2846264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2847c50d8ae3SPaolo Bonzini */ 2848c50d8ae3SPaolo Bonzini smp_wmb(); 2849c50d8ae3SPaolo Bonzini 28500337f585SSean Christopherson return 0; 2851c50d8ae3SPaolo Bonzini } 2852c50d8ae3SPaolo Bonzini 28538a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 28548a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2855a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2856799a4190SBen Gardon { 2857d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2858eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2859c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2860c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2861c50d8ae3SPaolo Bonzini bool flush = false; 2862ad67e480SPaolo Bonzini bool wrprot; 2863d786c778SPaolo Bonzini u64 spte; 2864c50d8ae3SPaolo Bonzini 2865a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2866a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 28672839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2868a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2869c50d8ae3SPaolo Bonzini 2870a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 28711075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2872a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2873a54aa15cSSean Christopherson return RET_PF_EMULATE; 2874a54aa15cSSean Christopherson } 2875a54aa15cSSean Christopherson 2876c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2877c50d8ae3SPaolo Bonzini /* 2878c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2879c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2880c50d8ae3SPaolo Bonzini */ 28813bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2882c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2883c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2884c50d8ae3SPaolo Bonzini 28855e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2886069f30c6SMingwei Zhang drop_parent_pte(vcpu->kvm, child, sptep); 2887c50d8ae3SPaolo Bonzini flush = true; 2888c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2889c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2890c50d8ae3SPaolo Bonzini flush = true; 2891c50d8ae3SPaolo Bonzini } else 2892c50d8ae3SPaolo Bonzini was_rmapped = 1; 2893c50d8ae3SPaolo Bonzini } 2894c50d8ae3SPaolo Bonzini 28952839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 28967158bee4SPaolo Bonzini true, host_writable, &spte); 2897d786c778SPaolo Bonzini 2898d786c778SPaolo Bonzini if (*sptep == spte) { 2899d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2900d786c778SPaolo Bonzini } else { 2901d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 29025959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2903c50d8ae3SPaolo Bonzini } 2904c50d8ae3SPaolo Bonzini 2905ad67e480SPaolo Bonzini if (wrprot) { 2906c50d8ae3SPaolo Bonzini if (write_fault) 2907c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2908c50d8ae3SPaolo Bonzini } 2909c50d8ae3SPaolo Bonzini 2910d786c778SPaolo Bonzini if (flush) 29114ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(vcpu->kvm, gfn, level); 2912c50d8ae3SPaolo Bonzini 2913c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2914d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 29156a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 29166a97575dSDavid Matlack } else { 29176a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 291879e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2919c50d8ae3SPaolo Bonzini } 2920c50d8ae3SPaolo Bonzini 2921c50d8ae3SPaolo Bonzini return ret; 2922c50d8ae3SPaolo Bonzini } 2923c50d8ae3SPaolo Bonzini 2924c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2925c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2926c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2927c50d8ae3SPaolo Bonzini { 2928c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2929c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 29300a2b64c5SBen Gardon unsigned int access = sp->role.access; 2931c50d8ae3SPaolo Bonzini int i, ret; 2932c50d8ae3SPaolo Bonzini gfn_t gfn; 2933c50d8ae3SPaolo Bonzini 293479e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 2935c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2936c50d8ae3SPaolo Bonzini if (!slot) 2937c50d8ae3SPaolo Bonzini return -1; 2938c50d8ae3SPaolo Bonzini 2939c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2940c50d8ae3SPaolo Bonzini if (ret <= 0) 2941c50d8ae3SPaolo Bonzini return -1; 2942c50d8ae3SPaolo Bonzini 2943c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 29448a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2945a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2946c50d8ae3SPaolo Bonzini put_page(pages[i]); 2947c50d8ae3SPaolo Bonzini } 2948c50d8ae3SPaolo Bonzini 2949c50d8ae3SPaolo Bonzini return 0; 2950c50d8ae3SPaolo Bonzini } 2951c50d8ae3SPaolo Bonzini 2952c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2953c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2954c50d8ae3SPaolo Bonzini { 2955c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2956c50d8ae3SPaolo Bonzini int i; 2957c50d8ae3SPaolo Bonzini 295820ba462dSSean Christopherson WARN_ON_ONCE(!sp->role.direct); 2959c50d8ae3SPaolo Bonzini 296079e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 2961c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2962c50d8ae3SPaolo Bonzini 2963c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2964c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2965c50d8ae3SPaolo Bonzini if (!start) 2966c50d8ae3SPaolo Bonzini continue; 2967c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2968c6cecc4bSSean Christopherson return; 2969c50d8ae3SPaolo Bonzini start = NULL; 2970c50d8ae3SPaolo Bonzini } else if (!start) 2971c50d8ae3SPaolo Bonzini start = spte; 2972c50d8ae3SPaolo Bonzini } 2973c6cecc4bSSean Christopherson if (start) 2974c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2975c50d8ae3SPaolo Bonzini } 2976c50d8ae3SPaolo Bonzini 2977c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2978c50d8ae3SPaolo Bonzini { 2979c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2980c50d8ae3SPaolo Bonzini 298157354682SSean Christopherson sp = sptep_to_sp(sptep); 2982c50d8ae3SPaolo Bonzini 2983c50d8ae3SPaolo Bonzini /* 2984c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2985c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2986c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2987c50d8ae3SPaolo Bonzini */ 2988c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2989c50d8ae3SPaolo Bonzini return; 2990c50d8ae3SPaolo Bonzini 29913bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2992c50d8ae3SPaolo Bonzini return; 2993c50d8ae3SPaolo Bonzini 29944a42d848SDavid Stevens /* 29954a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 29964a42d848SDavid Stevens * accidentally prefetching those addresses. 29974a42d848SDavid Stevens */ 299820ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 29994a42d848SDavid Stevens return; 30004a42d848SDavid Stevens 3001c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 3002c50d8ae3SPaolo Bonzini } 3003c50d8ae3SPaolo Bonzini 300465e3b446SSean Christopherson /* 300565e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 300665e3b446SSean Christopherson * 300765e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 300865e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 300965e3b446SSean Christopherson * 301065e3b446SSean Christopherson * There are several ways to safely use this helper: 301165e3b446SSean Christopherson * 30128569992dSChao Peng * - Check mmu_invalidate_retry_gfn() after grabbing the mapping level, before 301365e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 301465e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 301565e3b446SSean Christopherson * 301665e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 301765e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 301865e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 301965e3b446SSean Christopherson * 302065e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 302165e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 302265e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 302365e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 302465e3b446SSean Christopherson * 302565e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 302665e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 302765e3b446SSean Christopherson * race with the primary MMU occurs. 302865e3b446SSean Christopherson */ 3029a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 30308ca6f063SBen Gardon const struct kvm_memory_slot *slot) 3031db543216SSean Christopherson { 3032284dc493SSean Christopherson int level = PG_LEVEL_4K; 3033db543216SSean Christopherson unsigned long hva; 303444187235SMingwei Zhang unsigned long flags; 303544187235SMingwei Zhang pgd_t pgd; 303644187235SMingwei Zhang p4d_t p4d; 303744187235SMingwei Zhang pud_t pud; 303844187235SMingwei Zhang pmd_t pmd; 3039db543216SSean Christopherson 30405d49f08cSSean Christopherson /* 3041293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 3042293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 3043293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 3044293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 3045293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 3046293e306eSSean Christopherson * read-only memslot. 3047293e306eSSean Christopherson */ 3048db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 3049db543216SSean Christopherson 305044187235SMingwei Zhang /* 305165e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 305265e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 305365e3b446SSean Christopherson * the original page table. 305444187235SMingwei Zhang */ 305544187235SMingwei Zhang local_irq_save(flags); 3056db543216SSean Christopherson 305765e3b446SSean Christopherson /* 305865e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 305965e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 3060e72c7c2bSPeter Xu * walk into the weeks, e.g. p*d_leaf() returns false (sees the old 306165e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 306265e3b446SSean Christopherson * of the old page table (sees the new value). 306365e3b446SSean Christopherson */ 306444187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 306544187235SMingwei Zhang if (pgd_none(pgd)) 306644187235SMingwei Zhang goto out; 306744187235SMingwei Zhang 306844187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 306944187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 307044187235SMingwei Zhang goto out; 307144187235SMingwei Zhang 307244187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 307344187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 307444187235SMingwei Zhang goto out; 307544187235SMingwei Zhang 30760a845e0fSPeter Xu if (pud_leaf(pud)) { 307744187235SMingwei Zhang level = PG_LEVEL_1G; 307844187235SMingwei Zhang goto out; 307944187235SMingwei Zhang } 308044187235SMingwei Zhang 308144187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 308244187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 308344187235SMingwei Zhang goto out; 308444187235SMingwei Zhang 30852f709f7bSPeter Xu if (pmd_leaf(pmd)) 308644187235SMingwei Zhang level = PG_LEVEL_2M; 308744187235SMingwei Zhang 308844187235SMingwei Zhang out: 308944187235SMingwei Zhang local_irq_restore(flags); 3090db543216SSean Christopherson return level; 3091db543216SSean Christopherson } 3092db543216SSean Christopherson 30938dd2eee9SChao Peng static int __kvm_mmu_max_mapping_level(struct kvm *kvm, 30948dd2eee9SChao Peng const struct kvm_memory_slot *slot, 30958dd2eee9SChao Peng gfn_t gfn, int max_level, bool is_private) 30961b6d9d9eSSean Christopherson { 30971b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3098ec607a56SPaolo Bonzini int host_level; 30991b6d9d9eSSean Christopherson 31001b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 31011b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 31021b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 31031b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 31041b6d9d9eSSean Christopherson break; 31051b6d9d9eSSean Christopherson } 31061b6d9d9eSSean Christopherson 31078dd2eee9SChao Peng if (is_private) 31088dd2eee9SChao Peng return max_level; 31098dd2eee9SChao Peng 31101b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 31111b6d9d9eSSean Christopherson return PG_LEVEL_4K; 31121b6d9d9eSSean Christopherson 3113a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3114ec607a56SPaolo Bonzini return min(host_level, max_level); 31151b6d9d9eSSean Christopherson } 31161b6d9d9eSSean Christopherson 31178dd2eee9SChao Peng int kvm_mmu_max_mapping_level(struct kvm *kvm, 31188dd2eee9SChao Peng const struct kvm_memory_slot *slot, gfn_t gfn, 31198dd2eee9SChao Peng int max_level) 31208dd2eee9SChao Peng { 31218dd2eee9SChao Peng bool is_private = kvm_slot_can_be_private(slot) && 31228dd2eee9SChao Peng kvm_mem_is_private(kvm, gfn); 31238dd2eee9SChao Peng 31248dd2eee9SChao Peng return __kvm_mmu_max_mapping_level(kvm, slot, gfn, max_level, is_private); 31258dd2eee9SChao Peng } 31268dd2eee9SChao Peng 312773a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 31280885904dSSean Christopherson { 3129e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 313017eff019SSean Christopherson kvm_pfn_t mask; 31310885904dSSean Christopherson 313273a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 31333cf06612SSean Christopherson 313473a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 313573a3c659SPaolo Bonzini return; 313617eff019SSean Christopherson 31375d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 313873a3c659SPaolo Bonzini return; 313917eff019SSean Christopherson 3140e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 314173a3c659SPaolo Bonzini return; 3142293e306eSSean Christopherson 31433cf06612SSean Christopherson /* 31443cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 31453cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 31463cf06612SSean Christopherson */ 31478dd2eee9SChao Peng fault->req_level = __kvm_mmu_max_mapping_level(vcpu->kvm, slot, 31488dd2eee9SChao Peng fault->gfn, fault->max_level, 31498dd2eee9SChao Peng fault->is_private); 315073a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 315173a3c659SPaolo Bonzini return; 31524cd071d1SSean Christopherson 31530885904dSSean Christopherson /* 315420ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 31554cd071d1SSean Christopherson * the pmd can't be split from under us. 31560885904dSSean Christopherson */ 315773a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 315873a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 315973a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 316073a3c659SPaolo Bonzini fault->pfn &= ~mask; 31610885904dSSean Christopherson } 31620885904dSSean Christopherson 3163536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3164c50d8ae3SPaolo Bonzini { 3165536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3166536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3167c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 316876901e56SMingwei Zhang !is_large_pte(spte) && 316976901e56SMingwei Zhang spte_to_child_sp(spte)->nx_huge_page_disallowed) { 3170c50d8ae3SPaolo Bonzini /* 31716c882ef4SDavid Matlack * A small SPTE exists for this pfn, but FNAME(fetch), 31726c882ef4SDavid Matlack * direct_map(), or kvm_tdp_mmu_map() would like to create a 31736c882ef4SDavid Matlack * large PTE instead: just force them to go down another level, 31746c882ef4SDavid Matlack * patching back for them into pfn the next 9 bits of the 31756c882ef4SDavid Matlack * address. 3176c50d8ae3SPaolo Bonzini */ 3177536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3178536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3179536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3180536f0e6aSPaolo Bonzini fault->goal_level--; 3181c50d8ae3SPaolo Bonzini } 3182c50d8ae3SPaolo Bonzini } 3183c50d8ae3SPaolo Bonzini 31846c882ef4SDavid Matlack static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3185c50d8ae3SPaolo Bonzini { 3186c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3187c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 318873a3c659SPaolo Bonzini int ret; 318943b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3190c50d8ae3SPaolo Bonzini 319173a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 31924cd071d1SSean Christopherson 3193f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 319443b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3195c50d8ae3SPaolo Bonzini /* 3196c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3197c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3198c50d8ae3SPaolo Bonzini */ 319973a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3200536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3201c50d8ae3SPaolo Bonzini 3202c667a3baSHou Wenlong base_gfn = gfn_round_for_level(fault->gfn, it.level); 320373a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3204c50d8ae3SPaolo Bonzini break; 3205c50d8ae3SPaolo Bonzini 32062e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 32070cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 32080cd8dc73SPaolo Bonzini continue; 3209c50d8ae3SPaolo Bonzini 3210c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 3211b5b0977fSSean Christopherson if (fault->huge_page_disallowed) 321255c510e2SSean Christopherson account_nx_huge_page(vcpu->kvm, sp, 3213428e9216SSean Christopherson fault->req_level >= it.level); 3214c50d8ae3SPaolo Bonzini } 3215c50d8ae3SPaolo Bonzini 3216b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3217b1a429fbSSean Christopherson return -EFAULT; 3218b1a429fbSSean Christopherson 32198a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3220a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 322112703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 322212703759SSean Christopherson return ret; 322312703759SSean Christopherson 3224c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3225c50d8ae3SPaolo Bonzini return ret; 3226c50d8ae3SPaolo Bonzini } 3227c50d8ae3SPaolo Bonzini 3228cd08d178SDavid Matlack static void kvm_send_hwpoison_signal(struct kvm_memory_slot *slot, gfn_t gfn) 3229c50d8ae3SPaolo Bonzini { 3230cd08d178SDavid Matlack unsigned long hva = gfn_to_hva_memslot(slot, gfn); 3231cd08d178SDavid Matlack 3232cd08d178SDavid Matlack send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); 3233c50d8ae3SPaolo Bonzini } 3234c50d8ae3SPaolo Bonzini 3235cd08d178SDavid Matlack static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3236c50d8ae3SPaolo Bonzini { 3237cd08d178SDavid Matlack if (is_sigpending_pfn(fault->pfn)) { 323876657687SPeter Xu kvm_handle_signal_exit(vcpu); 323976657687SPeter Xu return -EINTR; 324076657687SPeter Xu } 324176657687SPeter Xu 3242c50d8ae3SPaolo Bonzini /* 3243c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3244c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3245c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3246c50d8ae3SPaolo Bonzini */ 3247cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_RO_FAULT) 3248c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3249c50d8ae3SPaolo Bonzini 3250cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_HWPOISON) { 3251cd08d178SDavid Matlack kvm_send_hwpoison_signal(fault->slot, fault->gfn); 3252c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3253c50d8ae3SPaolo Bonzini } 3254c50d8ae3SPaolo Bonzini 3255c50d8ae3SPaolo Bonzini return -EFAULT; 3256c50d8ae3SPaolo Bonzini } 3257c50d8ae3SPaolo Bonzini 3258354c908cSDavid Matlack static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu, 3259354c908cSDavid Matlack struct kvm_page_fault *fault, 32605276c616SSean Christopherson unsigned int access) 3261c50d8ae3SPaolo Bonzini { 32623a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 32633a13f4feSPaolo Bonzini 3264bde9f9d2SSean Christopherson if (fault->is_private) { 3265bde9f9d2SSean Christopherson kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 3266bde9f9d2SSean Christopherson return -EFAULT; 3267bde9f9d2SSean Christopherson } 3268bde9f9d2SSean Christopherson 32693a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3270c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 3271354c908cSDavid Matlack 3272f6adeae8SSean Christopherson fault->slot = NULL; 3273f6adeae8SSean Christopherson fault->pfn = KVM_PFN_NOSLOT; 3274f6adeae8SSean Christopherson fault->map_writable = false; 327536d44927SSean Christopherson fault->hva = KVM_HVA_ERR_BAD; 3276f6adeae8SSean Christopherson 327730ab5901SSean Christopherson /* 327830ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 327930ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 3280354c908cSDavid Matlack * MMIO SPTE will just be an expensive nop. 328130ab5901SSean Christopherson */ 3282354c908cSDavid Matlack if (unlikely(!enable_mmio_caching)) 32835276c616SSean Christopherson return RET_PF_EMULATE; 3284354c908cSDavid Matlack 3285354c908cSDavid Matlack /* 3286354c908cSDavid Matlack * Do not create an MMIO SPTE for a gfn greater than host.MAXPHYADDR, 3287354c908cSDavid Matlack * any guest that generates such gfns is running nested and is being 3288354c908cSDavid Matlack * tricked by L0 userspace (you can observe gfn > L1.MAXPHYADDR if and 3289354c908cSDavid Matlack * only if L1's MAXPHYADDR is inaccurate with respect to the 3290354c908cSDavid Matlack * hardware's). 3291354c908cSDavid Matlack */ 3292354c908cSDavid Matlack if (unlikely(fault->gfn > kvm_mmu_max_gfn())) 3293354c908cSDavid Matlack return RET_PF_EMULATE; 3294c50d8ae3SPaolo Bonzini 32955276c616SSean Christopherson return RET_PF_CONTINUE; 3296c50d8ae3SPaolo Bonzini } 3297c50d8ae3SPaolo Bonzini 32983c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3299c50d8ae3SPaolo Bonzini { 3300c50d8ae3SPaolo Bonzini /* 33015c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 33025c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 33035c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 33045c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3305c50d8ae3SPaolo Bonzini */ 33063c8ad5a6SPaolo Bonzini if (fault->rsvd) 3307c50d8ae3SPaolo Bonzini return false; 3308c50d8ae3SPaolo Bonzini 3309c50d8ae3SPaolo Bonzini /* 3310c50d8ae3SPaolo Bonzini * #PF can be fast if: 3311c50d8ae3SPaolo Bonzini * 331254275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 331354275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 331454275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 331554275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 331654275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 331754275f74SSean Christopherson * mechanism only supports direct MMUs. 331854275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 331954275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 332054275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 332154275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 332254275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3323c50d8ae3SPaolo Bonzini */ 33245c64aba5SSean Christopherson if (!fault->present) 33255c64aba5SSean Christopherson return !kvm_ad_enabled(); 33265c64aba5SSean Christopherson 33275c64aba5SSean Christopherson /* 33285c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 33295c64aba5SSean Christopherson * the "exec" flag. 33305c64aba5SSean Christopherson */ 33315c64aba5SSean Christopherson return fault->write; 3332c50d8ae3SPaolo Bonzini } 3333c50d8ae3SPaolo Bonzini 3334c50d8ae3SPaolo Bonzini /* 3335c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3336c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3337c50d8ae3SPaolo Bonzini */ 3338f3d90f90SSean Christopherson static bool fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, 3339f3d90f90SSean Christopherson struct kvm_page_fault *fault, 3340c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3341c50d8ae3SPaolo Bonzini { 3342c50d8ae3SPaolo Bonzini /* 3343c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3344c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3345c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3346c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3347c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3348c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3349c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3350c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3351c50d8ae3SPaolo Bonzini * 3352c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3353c50d8ae3SPaolo Bonzini */ 33542db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3355c50d8ae3SPaolo Bonzini return false; 3356c50d8ae3SPaolo Bonzini 3357e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3358e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3359c50d8ae3SPaolo Bonzini 3360c50d8ae3SPaolo Bonzini return true; 3361c50d8ae3SPaolo Bonzini } 3362c50d8ae3SPaolo Bonzini 33633c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3364c50d8ae3SPaolo Bonzini { 33653c8ad5a6SPaolo Bonzini if (fault->exec) 3366c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3367c50d8ae3SPaolo Bonzini 33683c8ad5a6SPaolo Bonzini if (fault->write) 3369c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3370c50d8ae3SPaolo Bonzini 3371c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3372c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3373c50d8ae3SPaolo Bonzini } 3374c50d8ae3SPaolo Bonzini 3375c50d8ae3SPaolo Bonzini /* 33766e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 33776e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 33786e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 33796e8eb206SDavid Matlack * 33806e8eb206SDavid Matlack * Contract: 33816e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 33826e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 33836e8eb206SDavid Matlack */ 33846e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 33856e8eb206SDavid Matlack { 33866e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 33876e8eb206SDavid Matlack u64 old_spte; 33886e8eb206SDavid Matlack u64 *sptep = NULL; 33896e8eb206SDavid Matlack 33906e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 33916e8eb206SDavid Matlack sptep = iterator.sptep; 33926e8eb206SDavid Matlack *spte = old_spte; 33936e8eb206SDavid Matlack } 33946e8eb206SDavid Matlack 33956e8eb206SDavid Matlack return sptep; 33966e8eb206SDavid Matlack } 33976e8eb206SDavid Matlack 33986e8eb206SDavid Matlack /* 3399c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3400c50d8ae3SPaolo Bonzini */ 34013c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3402c50d8ae3SPaolo Bonzini { 3403c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3404c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 34051de9992fSLi zeming u64 spte; 34061de9992fSLi zeming u64 *sptep; 3407c50d8ae3SPaolo Bonzini uint retry_count = 0; 3408c50d8ae3SPaolo Bonzini 34093c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3410c4371c2aSSean Christopherson return ret; 3411c50d8ae3SPaolo Bonzini 3412c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3413c50d8ae3SPaolo Bonzini 3414c50d8ae3SPaolo Bonzini do { 3415c50d8ae3SPaolo Bonzini u64 new_spte; 3416c50d8ae3SPaolo Bonzini 3417dfe0ecc6SSean Christopherson if (tdp_mmu_enabled) 34183c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 34196e8eb206SDavid Matlack else 34203c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3421c50d8ae3SPaolo Bonzini 34221de9992fSLi zeming /* 34231de9992fSLi zeming * It's entirely possible for the mapping to have been zapped 34241de9992fSLi zeming * by a different task, but the root page should always be 34251de9992fSLi zeming * available as the vCPU holds a reference to its root(s). 34261de9992fSLi zeming */ 34271de9992fSLi zeming if (WARN_ON_ONCE(!sptep)) 34281de9992fSLi zeming spte = REMOVED_SPTE; 34291de9992fSLi zeming 3430ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3431ec89e643SSean Christopherson break; 3432ec89e643SSean Christopherson 34336e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3434c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3435c50d8ae3SPaolo Bonzini break; 3436c50d8ae3SPaolo Bonzini 3437c50d8ae3SPaolo Bonzini /* 3438c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3439c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3440c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3441c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3442c50d8ae3SPaolo Bonzini * current CPU took the fault. 3443c50d8ae3SPaolo Bonzini * 3444c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3445c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3446c50d8ae3SPaolo Bonzini */ 34473c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3448c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3449c50d8ae3SPaolo Bonzini break; 3450c50d8ae3SPaolo Bonzini } 3451c50d8ae3SPaolo Bonzini 3452c50d8ae3SPaolo Bonzini new_spte = spte; 3453c50d8ae3SPaolo Bonzini 345454275f74SSean Christopherson /* 345554275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 345654275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 345754275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 345854275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 345954275f74SSean Christopherson */ 346054275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3461c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3462c50d8ae3SPaolo Bonzini 3463c50d8ae3SPaolo Bonzini /* 346454275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 346554275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 346654275f74SSean Christopherson * that were write-protected for dirty-logging or access 346754275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 346854275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 346954275f74SSean Christopherson * The is_access_allowed() check above handles the common case 347054275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 347154275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 347254275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3473c50d8ae3SPaolo Bonzini */ 3474706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3475c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3476c50d8ae3SPaolo Bonzini 3477c50d8ae3SPaolo Bonzini /* 347810c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 347910c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 348010c30de0SJunaid Shahid * first page into the dirty-bitmap in 3481c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3482c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3483c50d8ae3SPaolo Bonzini * 3484c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3485c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3486c50d8ae3SPaolo Bonzini */ 348710c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 348810c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3489c50d8ae3SPaolo Bonzini break; 3490c50d8ae3SPaolo Bonzini } 3491c50d8ae3SPaolo Bonzini 3492c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3493c50d8ae3SPaolo Bonzini if (new_spte == spte || 34943c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3495c50d8ae3SPaolo Bonzini break; 3496c50d8ae3SPaolo Bonzini 3497c50d8ae3SPaolo Bonzini /* 3498c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3499c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 35003ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3501c50d8ae3SPaolo Bonzini */ 3502e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3503c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3504c50d8ae3SPaolo Bonzini break; 3505c4371c2aSSean Christopherson } 3506c50d8ae3SPaolo Bonzini 3507c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 35088d20bd63SSean Christopherson pr_warn_once("Fast #PF retrying more than 4 times.\n"); 3509c50d8ae3SPaolo Bonzini break; 3510c50d8ae3SPaolo Bonzini } 3511c50d8ae3SPaolo Bonzini 3512c50d8ae3SPaolo Bonzini } while (true); 3513c50d8ae3SPaolo Bonzini 3514f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3515c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3516c50d8ae3SPaolo Bonzini 35171075d41eSSean Christopherson if (ret != RET_PF_INVALID) 35181075d41eSSean Christopherson vcpu->stat.pf_fast++; 35191075d41eSSean Christopherson 3520c4371c2aSSean Christopherson return ret; 3521c50d8ae3SPaolo Bonzini } 3522c50d8ae3SPaolo Bonzini 3523c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3524c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3525c50d8ae3SPaolo Bonzini { 3526c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3527c50d8ae3SPaolo Bonzini 3528c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3529c50d8ae3SPaolo Bonzini return; 3530c50d8ae3SPaolo Bonzini 3531c5f2d564SSean Christopherson sp = root_to_sp(*root_hpa); 353220ba462dSSean Christopherson if (WARN_ON_ONCE(!sp)) 35339191b8f0SPaolo Bonzini return; 353402c00b3aSBen Gardon 3535576a15deSSean Christopherson if (is_tdp_mmu_page(sp)) { 3536576a15deSSean Christopherson lockdep_assert_held_read(&kvm->mmu_lock); 35375f3c8c91SPaolo Bonzini kvm_tdp_mmu_put_root(kvm, sp); 3538576a15deSSean Christopherson } else { 3539576a15deSSean Christopherson lockdep_assert_held_write(&kvm->mmu_lock); 3540576a15deSSean Christopherson if (!--sp->root_count && sp->role.invalid) 3541c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3542576a15deSSean Christopherson } 3543c50d8ae3SPaolo Bonzini 3544c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3545c50d8ae3SPaolo Bonzini } 3546c50d8ae3SPaolo Bonzini 3547c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 35480c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3549c50d8ae3SPaolo Bonzini ulong roots_to_free) 3550c50d8ae3SPaolo Bonzini { 3551576a15deSSean Christopherson bool is_tdp_mmu = tdp_mmu_enabled && mmu->root_role.direct; 3552c50d8ae3SPaolo Bonzini int i; 3553c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3554594bef79SPaolo Bonzini bool free_active_root; 3555c50d8ae3SPaolo Bonzini 3556f94db0c8SSean Christopherson WARN_ON_ONCE(roots_to_free & ~KVM_MMU_ROOTS_ALL); 3557f94db0c8SSean Christopherson 3558c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3559c50d8ae3SPaolo Bonzini 3560c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3561594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3562594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3563594bef79SPaolo Bonzini 3564594bef79SPaolo Bonzini if (!free_active_root) { 3565c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3566c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3567c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3568c50d8ae3SPaolo Bonzini break; 3569c50d8ae3SPaolo Bonzini 3570c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3571c50d8ae3SPaolo Bonzini return; 3572c50d8ae3SPaolo Bonzini } 3573c50d8ae3SPaolo Bonzini 3574576a15deSSean Christopherson if (is_tdp_mmu) 3575576a15deSSean Christopherson read_lock(&kvm->mmu_lock); 3576576a15deSSean Christopherson else 3577531810caSBen Gardon write_lock(&kvm->mmu_lock); 3578c50d8ae3SPaolo Bonzini 3579c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3580c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 35814d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3582c50d8ae3SPaolo Bonzini &invalid_list); 3583c50d8ae3SPaolo Bonzini 3584c50d8ae3SPaolo Bonzini if (free_active_root) { 35850e3223d8SSean Christopherson if (kvm_mmu_is_dummy_root(mmu->root.hpa)) { 35860e3223d8SSean Christopherson /* Nothing to cleanup for dummy roots. */ 35870e3223d8SSean Christopherson } else if (root_to_sp(mmu->root.hpa)) { 3588b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 358904d45551SSean Christopherson } else if (mmu->pae_root) { 3590c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3591c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3592c834e5e4SSean Christopherson continue; 3593c834e5e4SSean Christopherson 3594c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3595c50d8ae3SPaolo Bonzini &invalid_list); 3596c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3597c50d8ae3SPaolo Bonzini } 3598c50d8ae3SPaolo Bonzini } 3599b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3600b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3601c50d8ae3SPaolo Bonzini } 3602c50d8ae3SPaolo Bonzini 3603576a15deSSean Christopherson if (is_tdp_mmu) { 3604576a15deSSean Christopherson read_unlock(&kvm->mmu_lock); 3605576a15deSSean Christopherson WARN_ON_ONCE(!list_empty(&invalid_list)); 3606576a15deSSean Christopherson } else { 36074d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3608531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3609c50d8ae3SPaolo Bonzini } 3610576a15deSSean Christopherson } 3611c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3612c50d8ae3SPaolo Bonzini 36130c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 361425b62c62SSean Christopherson { 361525b62c62SSean Christopherson unsigned long roots_to_free = 0; 3616c5f2d564SSean Christopherson struct kvm_mmu_page *sp; 361725b62c62SSean Christopherson hpa_t root_hpa; 361825b62c62SSean Christopherson int i; 361925b62c62SSean Christopherson 362025b62c62SSean Christopherson /* 362125b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 362225b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 362325b62c62SSean Christopherson */ 36247a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 362525b62c62SSean Christopherson 362625b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 362725b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 362825b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 362925b62c62SSean Christopherson continue; 363025b62c62SSean Christopherson 3631c5f2d564SSean Christopherson sp = root_to_sp(root_hpa); 3632c5f2d564SSean Christopherson if (!sp || sp->role.guest_mode) 363325b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 363425b62c62SSean Christopherson } 363525b62c62SSean Christopherson 36360c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 363725b62c62SSean Christopherson } 363825b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 363925b62c62SSean Christopherson 36402e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 364186938ab6SDavid Matlack u8 level) 3642c50d8ae3SPaolo Bonzini { 36432e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3644c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 36458123f265SSean Christopherson 36462e65e842SDavid Matlack role.level = level; 36472e65e842SDavid Matlack role.quadrant = quadrant; 36482e65e842SDavid Matlack 36497f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 36507f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 36517f497775SDavid Matlack 365287654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 36538123f265SSean Christopherson ++sp->root_count; 36548123f265SSean Christopherson 36558123f265SSean Christopherson return __pa(sp->spt); 36568123f265SSean Christopherson } 36578123f265SSean Christopherson 36588123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 36598123f265SSean Christopherson { 3660b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3661a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 36628123f265SSean Christopherson hpa_t root; 3663c50d8ae3SPaolo Bonzini unsigned i; 36644a38162eSPaolo Bonzini int r; 36654a38162eSPaolo Bonzini 3666f5238c2aSSean Christopherson if (tdp_mmu_enabled) 3667f5238c2aSSean Christopherson return kvm_tdp_mmu_alloc_root(vcpu); 3668f5238c2aSSean Christopherson 36694a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36704a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36714a38162eSPaolo Bonzini if (r < 0) 36724a38162eSPaolo Bonzini goto out_unlock; 3673c50d8ae3SPaolo Bonzini 3674f5238c2aSSean Christopherson if (shadow_root_level >= PT64_ROOT_4LEVEL) { 367586938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3676b9e5603cSPaolo Bonzini mmu->root.hpa = root; 36778123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 36784a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 36794a38162eSPaolo Bonzini r = -EIO; 36804a38162eSPaolo Bonzini goto out_unlock; 36814a38162eSPaolo Bonzini } 368273ad1606SSean Christopherson 3683c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3684c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3685c50d8ae3SPaolo Bonzini 36867f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 36872e65e842SDavid Matlack PT32_ROOT_LEVEL); 368817e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3689d2263de1SYuan Yao shadow_me_value; 3690c50d8ae3SPaolo Bonzini } 3691b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 369273ad1606SSean Christopherson } else { 369373ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 36944a38162eSPaolo Bonzini r = -EIO; 36954a38162eSPaolo Bonzini goto out_unlock; 369673ad1606SSean Christopherson } 36973651c7fcSSean Christopherson 3698b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3699b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 37004a38162eSPaolo Bonzini out_unlock: 37014a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 37024a38162eSPaolo Bonzini return r; 3703c50d8ae3SPaolo Bonzini } 3704c50d8ae3SPaolo Bonzini 37051e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 37061e76a3ceSDavid Stevens { 37071e76a3ceSDavid Stevens struct kvm_memslots *slots; 37081e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3709a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 37101e76a3ceSDavid Stevens 37111e76a3ceSDavid Stevens /* 37121e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 37131e76a3ceSDavid Stevens * taking the lock. 37141e76a3ceSDavid Stevens */ 37151e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37161e76a3ceSDavid Stevens return 0; 37171e76a3ceSDavid Stevens 37181e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 37191e76a3ceSDavid Stevens 37201e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 37211e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37221e76a3ceSDavid Stevens goto out_unlock; 37231e76a3ceSDavid Stevens 37241e76a3ceSDavid Stevens /* 37251e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 37261e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 37271e76a3ceSDavid Stevens */ 37281e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 37291e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 37301e76a3ceSDavid Stevens goto out_success; 37311e76a3ceSDavid Stevens 3732eed52e43SSean Christopherson for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { 37331e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3734a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 37351e76a3ceSDavid Stevens /* 37361e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 37371e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 37381e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 37391e76a3ceSDavid Stevens * failure to avoid having to track which allocations 37401e76a3ceSDavid Stevens * were made now versus when the memslot was created. 37411e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 37421e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 37431e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 37441e76a3ceSDavid Stevens */ 37451e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 37461e76a3ceSDavid Stevens if (r) 37471e76a3ceSDavid Stevens goto out_unlock; 37481e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 37491e76a3ceSDavid Stevens if (r) 37501e76a3ceSDavid Stevens goto out_unlock; 37511e76a3ceSDavid Stevens } 37521e76a3ceSDavid Stevens } 37531e76a3ceSDavid Stevens 37541e76a3ceSDavid Stevens /* 37551e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 37561e76a3ceSDavid Stevens * all the related pointers are set. 37571e76a3ceSDavid Stevens */ 37581e76a3ceSDavid Stevens out_success: 37591e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 37601e76a3ceSDavid Stevens 37611e76a3ceSDavid Stevens out_unlock: 37621e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 37631e76a3ceSDavid Stevens return r; 37641e76a3ceSDavid Stevens } 37651e76a3ceSDavid Stevens 3766c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3767c50d8ae3SPaolo Bonzini { 3768b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 37696e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3770be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 37717f497775SDavid Matlack int quadrant, i, r; 37728123f265SSean Christopherson hpa_t root; 3773c50d8ae3SPaolo Bonzini 37742fdcc1b3SPaolo Bonzini root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu); 3775a130066fSBinbin Wu root_gfn = (root_pgd & __PT_BASE_ADDR_MASK) >> PAGE_SHIFT; 3776c50d8ae3SPaolo Bonzini 37770e3223d8SSean Christopherson if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 37780e3223d8SSean Christopherson mmu->root.hpa = kvm_mmu_get_dummy_root(); 37790e3223d8SSean Christopherson return 0; 37800e3223d8SSean Christopherson } 3781c50d8ae3SPaolo Bonzini 3782c50d8ae3SPaolo Bonzini /* 37834a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 37844a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 37854a38162eSPaolo Bonzini */ 37864d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 37876e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 37886e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 37896e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 37906e0918aeSSean Christopherson continue; 37916e0918aeSSean Christopherson 37920e3223d8SSean Christopherson if (!kvm_vcpu_is_visible_gfn(vcpu, pdptrs[i] >> PAGE_SHIFT)) 37930e3223d8SSean Christopherson pdptrs[i] = 0; 37946e0918aeSSean Christopherson } 37956e0918aeSSean Christopherson } 37966e0918aeSSean Christopherson 37971e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3798d501f747SBen Gardon if (r) 3799d501f747SBen Gardon return r; 3800d501f747SBen Gardon 38014a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 38024a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 38034a38162eSPaolo Bonzini if (r < 0) 38044a38162eSPaolo Bonzini goto out_unlock; 38054a38162eSPaolo Bonzini 3806c50d8ae3SPaolo Bonzini /* 3807c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3808c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3809c50d8ae3SPaolo Bonzini */ 38104d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 38118123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 381286938ab6SDavid Matlack mmu->root_role.level); 3813b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3814be01e8e2SSean Christopherson goto set_root_pgd; 3815c50d8ae3SPaolo Bonzini } 3816c50d8ae3SPaolo Bonzini 38174a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 38184a38162eSPaolo Bonzini r = -EIO; 38194a38162eSPaolo Bonzini goto out_unlock; 38204a38162eSPaolo Bonzini } 382173ad1606SSean Christopherson 3822c50d8ae3SPaolo Bonzini /* 3823c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3824c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3825c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3826c50d8ae3SPaolo Bonzini */ 3827e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3828a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3829c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3830c50d8ae3SPaolo Bonzini 383103ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 38324a38162eSPaolo Bonzini r = -EIO; 38334a38162eSPaolo Bonzini goto out_unlock; 38344a38162eSPaolo Bonzini } 383503ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3836cb0f722aSWei Huang 3837a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3838cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3839cb0f722aSWei Huang r = -EIO; 3840cb0f722aSWei Huang goto out_unlock; 3841cb0f722aSWei Huang } 3842cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3843cb0f722aSWei Huang } 384404d45551SSean Christopherson } 384504d45551SSean Christopherson 3846c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3847c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 38486e6ec584SSean Christopherson 38494d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38506e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3851c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3852c50d8ae3SPaolo Bonzini continue; 3853c50d8ae3SPaolo Bonzini } 38546e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3855c50d8ae3SPaolo Bonzini } 3856c50d8ae3SPaolo Bonzini 38577f497775SDavid Matlack /* 38587f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 38597f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 38607f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 38617f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 38627f497775SDavid Matlack */ 38637f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 38647f497775SDavid Matlack 38657f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3866b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3867c50d8ae3SPaolo Bonzini } 3868c50d8ae3SPaolo Bonzini 3869a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3870b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3871a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3872b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3873ba0a194fSSean Christopherson else 3874b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3875c50d8ae3SPaolo Bonzini 3876be01e8e2SSean Christopherson set_root_pgd: 3877b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 38784a38162eSPaolo Bonzini out_unlock: 38794a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3880c50d8ae3SPaolo Bonzini 3881c6c937d6SLike Xu return r; 3882c50d8ae3SPaolo Bonzini } 3883c50d8ae3SPaolo Bonzini 3884748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3885c50d8ae3SPaolo Bonzini { 3886748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3887a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3888cb0f722aSWei Huang u64 *pml5_root = NULL; 3889cb0f722aSWei Huang u64 *pml4_root = NULL; 3890cb0f722aSWei Huang u64 *pae_root; 3891748e52b9SSean Christopherson 3892748e52b9SSean Christopherson /* 3893748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3894748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3895748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3896748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3897748e52b9SSean Christopherson */ 3898347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3899347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3900a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3901748e52b9SSean Christopherson return 0; 3902748e52b9SSean Christopherson 3903a717a780SSean Christopherson /* 3904a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3905a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3906a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3907a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3908a717a780SSean Christopherson * prior MMU would also have required pml5. 3909a717a780SSean Christopherson */ 3910a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3911748e52b9SSean Christopherson return 0; 3912748e52b9SSean Christopherson 3913748e52b9SSean Christopherson /* 3914748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3915748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3916748e52b9SSean Christopherson */ 3917cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3918a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3919748e52b9SSean Christopherson return -EIO; 3920748e52b9SSean Christopherson 39214a98623dSSean Christopherson /* 39224a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 39234a98623dSSean Christopherson * doesn't need to be decrypted. 39244a98623dSSean Christopherson */ 3925748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3926748e52b9SSean Christopherson if (!pae_root) 3927748e52b9SSean Christopherson return -ENOMEM; 3928748e52b9SSean Christopherson 3929cb0f722aSWei Huang #ifdef CONFIG_X86_64 393003ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3931cb0f722aSWei Huang if (!pml4_root) 3932cb0f722aSWei Huang goto err_pml4; 3933cb0f722aSWei Huang 3934a717a780SSean Christopherson if (need_pml5) { 3935cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3936cb0f722aSWei Huang if (!pml5_root) 3937cb0f722aSWei Huang goto err_pml5; 3938748e52b9SSean Christopherson } 3939cb0f722aSWei Huang #endif 3940748e52b9SSean Christopherson 3941748e52b9SSean Christopherson mmu->pae_root = pae_root; 394203ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3943cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3944748e52b9SSean Christopherson 3945748e52b9SSean Christopherson return 0; 3946cb0f722aSWei Huang 3947cb0f722aSWei Huang #ifdef CONFIG_X86_64 3948cb0f722aSWei Huang err_pml5: 3949cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3950cb0f722aSWei Huang err_pml4: 3951cb0f722aSWei Huang free_page((unsigned long)pae_root); 3952cb0f722aSWei Huang return -ENOMEM; 3953cb0f722aSWei Huang #endif 3954c50d8ae3SPaolo Bonzini } 3955c50d8ae3SPaolo Bonzini 3956264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3957264d3dc1SLai Jiangshan { 3958264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3959264d3dc1SLai Jiangshan 39600e3223d8SSean Christopherson if (!VALID_PAGE(root) || kvm_mmu_is_dummy_root(root)) 396161b05a9fSLai Jiangshan return false; 396261b05a9fSLai Jiangshan 3963264d3dc1SLai Jiangshan /* 3964264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3965264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3966264d3dc1SLai Jiangshan * 3967264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3968264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3969264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3970264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3971264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3972264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3973264d3dc1SLai Jiangshan * requirement isn't satisfied. 3974264d3dc1SLai Jiangshan */ 3975264d3dc1SLai Jiangshan smp_rmb(); 3976c5f2d564SSean Christopherson sp = root_to_sp(root); 39775d6a3221SSean Christopherson 39785d6a3221SSean Christopherson /* 39795d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 39805d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 39815d6a3221SSean Christopherson */ 39825d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 39835d6a3221SSean Christopherson return false; 39845d6a3221SSean Christopherson 3985264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3986264d3dc1SLai Jiangshan return true; 3987264d3dc1SLai Jiangshan 3988264d3dc1SLai Jiangshan return false; 3989264d3dc1SLai Jiangshan } 3990264d3dc1SLai Jiangshan 3991c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3992c50d8ae3SPaolo Bonzini { 3993c50d8ae3SPaolo Bonzini int i; 3994c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3995c50d8ae3SPaolo Bonzini 3996347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3997c50d8ae3SPaolo Bonzini return; 3998c50d8ae3SPaolo Bonzini 3999b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 4000c50d8ae3SPaolo Bonzini return; 4001c50d8ae3SPaolo Bonzini 4002c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4003c50d8ae3SPaolo Bonzini 40044d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 4005b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 4006c50d8ae3SPaolo Bonzini 4007264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 4008c50d8ae3SPaolo Bonzini return; 4009c50d8ae3SPaolo Bonzini 4010c5f2d564SSean Christopherson sp = root_to_sp(root); 4011c5f2d564SSean Christopherson 4012531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 401365855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4014531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4015c50d8ae3SPaolo Bonzini return; 4016c50d8ae3SPaolo Bonzini } 4017c50d8ae3SPaolo Bonzini 4018531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4019c50d8ae3SPaolo Bonzini 4020c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 4021c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 4022c50d8ae3SPaolo Bonzini 4023c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 40245e3edd7eSSean Christopherson sp = spte_to_child_sp(root); 402565855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4026c50d8ae3SPaolo Bonzini } 4027c50d8ae3SPaolo Bonzini } 4028c50d8ae3SPaolo Bonzini 4029531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4030c50d8ae3SPaolo Bonzini } 4031c50d8ae3SPaolo Bonzini 403261b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 403361b05a9fSLai Jiangshan { 403461b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 403561b05a9fSLai Jiangshan int i; 403661b05a9fSLai Jiangshan 403761b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 403861b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 403961b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 404061b05a9fSLai Jiangshan 404161b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 40420c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 404361b05a9fSLai Jiangshan } 404461b05a9fSLai Jiangshan 40451f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 40465b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 4047c50d8ae3SPaolo Bonzini struct x86_exception *exception) 4048c50d8ae3SPaolo Bonzini { 4049c50d8ae3SPaolo Bonzini if (exception) 4050c50d8ae3SPaolo Bonzini exception->error_code = 0; 4051c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 4052c50d8ae3SPaolo Bonzini } 4053c50d8ae3SPaolo Bonzini 4054c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4055c50d8ae3SPaolo Bonzini { 4056c50d8ae3SPaolo Bonzini /* 4057c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 4058c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 4059c50d8ae3SPaolo Bonzini */ 4060c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 4061c50d8ae3SPaolo Bonzini return false; 4062c50d8ae3SPaolo Bonzini 4063c50d8ae3SPaolo Bonzini if (direct) 4064c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 4065c50d8ae3SPaolo Bonzini 4066c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 4067c50d8ae3SPaolo Bonzini } 4068c50d8ae3SPaolo Bonzini 406995fb5b02SBen Gardon /* 407095fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 407195fb5b02SBen Gardon * That SPTE may be non-present. 4072c5c8c7c5SDavid Matlack * 4073c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 407495fb5b02SBen Gardon */ 407539b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 4076c50d8ae3SPaolo Bonzini { 4077c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 40782aa07893SSean Christopherson int leaf = -1; 407995fb5b02SBen Gardon u64 spte; 4080c50d8ae3SPaolo Bonzini 408139b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 408239b4d43eSSean Christopherson *root_level = iterator.level; 4083c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 4084c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 408595fb5b02SBen Gardon leaf = iterator.level; 4086c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 4087c50d8ae3SPaolo Bonzini 4088dde81f94SSean Christopherson sptes[leaf] = spte; 408995fb5b02SBen Gardon } 409095fb5b02SBen Gardon 409195fb5b02SBen Gardon return leaf; 409295fb5b02SBen Gardon } 409395fb5b02SBen Gardon 40949aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 409595fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 409695fb5b02SBen Gardon { 4097dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 409895fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 409939b4d43eSSean Christopherson int root, leaf, level; 410095fb5b02SBen Gardon bool reserved = false; 410195fb5b02SBen Gardon 4102c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 4103c5c8c7c5SDavid Matlack 410478fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) 410539b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 410695fb5b02SBen Gardon else 410739b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 410895fb5b02SBen Gardon 4109c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 4110c5c8c7c5SDavid Matlack 41112aa07893SSean Christopherson if (unlikely(leaf < 0)) { 41122aa07893SSean Christopherson *sptep = 0ull; 41132aa07893SSean Christopherson return reserved; 41142aa07893SSean Christopherson } 41152aa07893SSean Christopherson 41169aa41879SSean Christopherson *sptep = sptes[leaf]; 41179aa41879SSean Christopherson 41189aa41879SSean Christopherson /* 41199aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 41209aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 41219aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 41229aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 41239aa41879SSean Christopherson */ 41249aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 41259aa41879SSean Christopherson leaf++; 412695fb5b02SBen Gardon 412795fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 412895fb5b02SBen Gardon 41299aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4130961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4131c50d8ae3SPaolo Bonzini 4132c50d8ae3SPaolo Bonzini if (reserved) { 4133bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4134c50d8ae3SPaolo Bonzini __func__, addr); 413595fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4136bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4137bb4cdf3aSSean Christopherson sptes[level], level, 4138961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4139c50d8ae3SPaolo Bonzini } 4140ddce6208SSean Christopherson 4141c50d8ae3SPaolo Bonzini return reserved; 4142c50d8ae3SPaolo Bonzini } 4143c50d8ae3SPaolo Bonzini 4144c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4145c50d8ae3SPaolo Bonzini { 4146c50d8ae3SPaolo Bonzini u64 spte; 4147c50d8ae3SPaolo Bonzini bool reserved; 4148c50d8ae3SPaolo Bonzini 4149c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4150c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4151c50d8ae3SPaolo Bonzini 415295fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 415320ba462dSSean Christopherson if (WARN_ON_ONCE(reserved)) 4154c50d8ae3SPaolo Bonzini return -EINVAL; 4155c50d8ae3SPaolo Bonzini 4156c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4157c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 41580a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4159c50d8ae3SPaolo Bonzini 4160c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4161c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4162c50d8ae3SPaolo Bonzini 4163c50d8ae3SPaolo Bonzini if (direct) 4164c50d8ae3SPaolo Bonzini addr = 0; 4165c50d8ae3SPaolo Bonzini 4166c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4167c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4168c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4169c50d8ae3SPaolo Bonzini } 4170c50d8ae3SPaolo Bonzini 4171c50d8ae3SPaolo Bonzini /* 4172c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4173c50d8ae3SPaolo Bonzini * the address. 4174c50d8ae3SPaolo Bonzini */ 4175c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4176c50d8ae3SPaolo Bonzini } 4177c50d8ae3SPaolo Bonzini 4178c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4179b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4180c50d8ae3SPaolo Bonzini { 4181b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4182c50d8ae3SPaolo Bonzini return false; 4183c50d8ae3SPaolo Bonzini 4184b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4185c50d8ae3SPaolo Bonzini return false; 4186c50d8ae3SPaolo Bonzini 4187c50d8ae3SPaolo Bonzini /* 4188c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4189c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4190c50d8ae3SPaolo Bonzini */ 41917b574863SSean Christopherson if (kvm_gfn_is_write_tracked(vcpu->kvm, fault->slot, fault->gfn)) 4192c50d8ae3SPaolo Bonzini return true; 4193c50d8ae3SPaolo Bonzini 4194c50d8ae3SPaolo Bonzini return false; 4195c50d8ae3SPaolo Bonzini } 4196c50d8ae3SPaolo Bonzini 4197c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4198c50d8ae3SPaolo Bonzini { 4199c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4200c50d8ae3SPaolo Bonzini u64 spte; 4201c50d8ae3SPaolo Bonzini 4202c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 42033e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4204c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4205c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4206c50d8ae3SPaolo Bonzini } 4207c50d8ae3SPaolo Bonzini 42086f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 42096f3c1fc5SLiang Zhang { 42106f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 42116f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 42126f3c1fc5SLiang Zhang 42136f3c1fc5SLiang Zhang if (id << 12 == 0) 42146f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 42156f3c1fc5SLiang Zhang 42166f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 42176f3c1fc5SLiang Zhang } 42186f3c1fc5SLiang Zhang 4219cd389f50SPaolo Bonzini static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, 4220cd389f50SPaolo Bonzini struct kvm_page_fault *fault) 4221c50d8ae3SPaolo Bonzini { 4222c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4223c50d8ae3SPaolo Bonzini 42246f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4225cd389f50SPaolo Bonzini arch.gfn = fault->gfn; 4226cd389f50SPaolo Bonzini arch.error_code = fault->error_code; 4227347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 42282fdcc1b3SPaolo Bonzini arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu); 4229c50d8ae3SPaolo Bonzini 4230cd389f50SPaolo Bonzini return kvm_setup_async_pf(vcpu, fault->addr, 4231cd389f50SPaolo Bonzini kvm_vcpu_gfn_to_hva(vcpu, fault->gfn), &arch); 4232c50d8ae3SPaolo Bonzini } 4233c50d8ae3SPaolo Bonzini 42348a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 42358a009d5bSSean Christopherson { 42368a009d5bSSean Christopherson int r; 42378a009d5bSSean Christopherson 4238cd389f50SPaolo Bonzini if (WARN_ON_ONCE(work->arch.error_code & PFERR_PRIVATE_ACCESS)) 4239cd389f50SPaolo Bonzini return; 4240cd389f50SPaolo Bonzini 42418a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 42428a009d5bSSean Christopherson work->wakeup_all) 42438a009d5bSSean Christopherson return; 42448a009d5bSSean Christopherson 42458a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 42468a009d5bSSean Christopherson if (unlikely(r)) 42478a009d5bSSean Christopherson return; 42488a009d5bSSean Christopherson 42498a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 42502fdcc1b3SPaolo Bonzini work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu)) 42518a009d5bSSean Christopherson return; 42528a009d5bSSean Christopherson 4253cd389f50SPaolo Bonzini kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, work->arch.error_code, true, NULL); 42548a009d5bSSean Christopherson } 42558a009d5bSSean Christopherson 42568dd2eee9SChao Peng static inline u8 kvm_max_level_for_order(int order) 42578dd2eee9SChao Peng { 42588dd2eee9SChao Peng BUILD_BUG_ON(KVM_MAX_HUGEPAGE_LEVEL > PG_LEVEL_1G); 42598dd2eee9SChao Peng 42608dd2eee9SChao Peng KVM_MMU_WARN_ON(order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_1G) && 42618dd2eee9SChao Peng order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_2M) && 42628dd2eee9SChao Peng order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_4K)); 42638dd2eee9SChao Peng 42648dd2eee9SChao Peng if (order >= KVM_HPAGE_GFN_SHIFT(PG_LEVEL_1G)) 42658dd2eee9SChao Peng return PG_LEVEL_1G; 42668dd2eee9SChao Peng 42678dd2eee9SChao Peng if (order >= KVM_HPAGE_GFN_SHIFT(PG_LEVEL_2M)) 42688dd2eee9SChao Peng return PG_LEVEL_2M; 42698dd2eee9SChao Peng 42708dd2eee9SChao Peng return PG_LEVEL_4K; 42718dd2eee9SChao Peng } 42728dd2eee9SChao Peng 42738dd2eee9SChao Peng static int kvm_faultin_pfn_private(struct kvm_vcpu *vcpu, 42748dd2eee9SChao Peng struct kvm_page_fault *fault) 42758dd2eee9SChao Peng { 42768dd2eee9SChao Peng int max_order, r; 42778dd2eee9SChao Peng 42788dd2eee9SChao Peng if (!kvm_slot_can_be_private(fault->slot)) { 42798dd2eee9SChao Peng kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 42808dd2eee9SChao Peng return -EFAULT; 42818dd2eee9SChao Peng } 42828dd2eee9SChao Peng 42838dd2eee9SChao Peng r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn, 42848dd2eee9SChao Peng &max_order); 42858dd2eee9SChao Peng if (r) { 42868dd2eee9SChao Peng kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 42878dd2eee9SChao Peng return r; 42888dd2eee9SChao Peng } 42898dd2eee9SChao Peng 42908dd2eee9SChao Peng fault->max_level = min(kvm_max_level_for_order(max_order), 42918dd2eee9SChao Peng fault->max_level); 42928dd2eee9SChao Peng fault->map_writable = !(fault->slot->flags & KVM_MEM_READONLY); 42938dd2eee9SChao Peng 42948dd2eee9SChao Peng return RET_PF_CONTINUE; 42958dd2eee9SChao Peng } 42968dd2eee9SChao Peng 4297ba6e3fe2SDavid Matlack static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4298c50d8ae3SPaolo Bonzini { 4299c50d8ae3SPaolo Bonzini bool async; 4300c50d8ae3SPaolo Bonzini 4301cd272fc4SSean Christopherson if (fault->is_private) 4302cd272fc4SSean Christopherson return kvm_faultin_pfn_private(vcpu, fault); 4303cd272fc4SSean Christopherson 4304cd272fc4SSean Christopherson async = false; 4305cd272fc4SSean Christopherson fault->pfn = __gfn_to_pfn_memslot(fault->slot, fault->gfn, false, false, 4306cd272fc4SSean Christopherson &async, fault->write, 4307cd272fc4SSean Christopherson &fault->map_writable, &fault->hva); 4308cd272fc4SSean Christopherson if (!async) 4309cd272fc4SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4310cd272fc4SSean Christopherson 4311cd272fc4SSean Christopherson if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 4312cd272fc4SSean Christopherson trace_kvm_try_async_get_page(fault->addr, fault->gfn); 4313cd272fc4SSean Christopherson if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 4314cd272fc4SSean Christopherson trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4315cd272fc4SSean Christopherson kvm_make_request(KVM_REQ_APF_HALT, vcpu); 4316cd272fc4SSean Christopherson return RET_PF_RETRY; 4317cd272fc4SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault)) { 4318cd272fc4SSean Christopherson return RET_PF_RETRY; 4319cd272fc4SSean Christopherson } 4320cd272fc4SSean Christopherson } 4321cd272fc4SSean Christopherson 4322cd272fc4SSean Christopherson /* 4323cd272fc4SSean Christopherson * Allow gup to bail on pending non-fatal signals when it's also allowed 4324cd272fc4SSean Christopherson * to wait for IO. Note, gup always bails if it is unable to quickly 4325cd272fc4SSean Christopherson * get a page and a fatal signal, i.e. SIGKILL, is pending. 4326cd272fc4SSean Christopherson */ 4327cd272fc4SSean Christopherson fault->pfn = __gfn_to_pfn_memslot(fault->slot, fault->gfn, false, true, 4328cd272fc4SSean Christopherson NULL, fault->write, 4329cd272fc4SSean Christopherson &fault->map_writable, &fault->hva); 4330cd272fc4SSean Christopherson return RET_PF_CONTINUE; 4331cd272fc4SSean Christopherson } 4332cd272fc4SSean Christopherson 4333cd272fc4SSean Christopherson static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 4334cd272fc4SSean Christopherson unsigned int access) 4335cd272fc4SSean Christopherson { 4336cd272fc4SSean Christopherson struct kvm_memory_slot *slot = fault->slot; 4337cd272fc4SSean Christopherson int ret; 4338cd272fc4SSean Christopherson 4339cd272fc4SSean Christopherson /* 4340cd272fc4SSean Christopherson * Note that the mmu_invalidate_seq also serves to detect a concurrent 4341cd272fc4SSean Christopherson * change in attributes. is_page_fault_stale() will detect an 4342cd272fc4SSean Christopherson * invalidation relate to fault->fn and resume the guest without 4343cd272fc4SSean Christopherson * installing a mapping in the page tables. 4344cd272fc4SSean Christopherson */ 4345cd272fc4SSean Christopherson fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4346cd272fc4SSean Christopherson smp_rmb(); 4347cd272fc4SSean Christopherson 4348cd272fc4SSean Christopherson /* 4349cd272fc4SSean Christopherson * Now that we have a snapshot of mmu_invalidate_seq we can check for a 4350cd272fc4SSean Christopherson * private vs. shared mismatch. 4351cd272fc4SSean Christopherson */ 4352cd272fc4SSean Christopherson if (fault->is_private != kvm_mem_is_private(vcpu->kvm, fault->gfn)) { 4353cd272fc4SSean Christopherson kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 4354cd272fc4SSean Christopherson return -EFAULT; 4355cd272fc4SSean Christopherson } 4356cd272fc4SSean Christopherson 4357f6adeae8SSean Christopherson if (unlikely(!slot)) 4358f6adeae8SSean Christopherson return kvm_handle_noslot_fault(vcpu, fault, access); 4359f6adeae8SSean Christopherson 4360e0c37868SSean Christopherson /* 4361e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4362e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4363e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4364e0c37868SSean Christopherson */ 4365f6adeae8SSean Christopherson if (slot->flags & KVM_MEMSLOT_INVALID) 43665276c616SSean Christopherson return RET_PF_RETRY; 4367e0c37868SSean Christopherson 4368f6adeae8SSean Christopherson if (slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT) { 43695bd74f6eSSean Christopherson /* 43705bd74f6eSSean Christopherson * Don't map L1's APIC access page into L2, KVM doesn't support 43715bd74f6eSSean Christopherson * using APICv/AVIC to accelerate L2 accesses to L1's APIC, 43725bd74f6eSSean Christopherson * i.e. the access needs to be emulated. Emulating access to 43735bd74f6eSSean Christopherson * L1's APIC is also correct if L1 is accelerating L2's own 43745bd74f6eSSean Christopherson * virtual APIC, but for some reason L1 also maps _L1's_ APIC 43755bd74f6eSSean Christopherson * into L2. Note, vcpu_is_mmio_gpa() always treats access to 43765bd74f6eSSean Christopherson * the APIC as MMIO. Allow an MMIO SPTE to be created, as KVM 43775bd74f6eSSean Christopherson * uses different roots for L1 vs. L2, i.e. there is no danger 43785bd74f6eSSean Christopherson * of breaking APICv/AVIC for L1. 43795bd74f6eSSean Christopherson */ 4380f6adeae8SSean Christopherson if (is_guest_mode(vcpu)) 4381f6adeae8SSean Christopherson return kvm_handle_noslot_fault(vcpu, fault, access); 4382f6adeae8SSean Christopherson 43839cc13d60SMaxim Levitsky /* 43849cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 43859cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 43869cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 43879cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 43889cc13d60SMaxim Levitsky */ 43895bd74f6eSSean Christopherson if (!kvm_apicv_activated(vcpu->kvm)) 43905276c616SSean Christopherson return RET_PF_EMULATE; 43919cc13d60SMaxim Levitsky } 4392c50d8ae3SPaolo Bonzini 4393f6adeae8SSean Christopherson fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4394f6adeae8SSean Christopherson smp_rmb(); 4395f6adeae8SSean Christopherson 439644f42ef3SSean Christopherson /* 4397d02c357eSSean Christopherson * Check for a relevant mmu_notifier invalidation event before getting 4398d02c357eSSean Christopherson * the pfn from the primary MMU, and before acquiring mmu_lock. 4399d02c357eSSean Christopherson * 4400d02c357eSSean Christopherson * For mmu_lock, if there is an in-progress invalidation and the kernel 4401d02c357eSSean Christopherson * allows preemption, the invalidation task may drop mmu_lock and yield 4402d02c357eSSean Christopherson * in response to mmu_lock being contended, which is *very* counter- 4403d02c357eSSean Christopherson * productive as this vCPU can't actually make forward progress until 4404d02c357eSSean Christopherson * the invalidation completes. 4405d02c357eSSean Christopherson * 4406d02c357eSSean Christopherson * Retrying now can also avoid unnessary lock contention in the primary 4407d02c357eSSean Christopherson * MMU, as the primary MMU doesn't necessarily hold a single lock for 4408d02c357eSSean Christopherson * the duration of the invalidation, i.e. faulting in a conflicting pfn 4409d02c357eSSean Christopherson * can cause the invalidation to take longer by holding locks that are 4410d02c357eSSean Christopherson * needed to complete the invalidation. 4411d02c357eSSean Christopherson * 4412d02c357eSSean Christopherson * Do the pre-check even for non-preemtible kernels, i.e. even if KVM 4413d02c357eSSean Christopherson * will never yield mmu_lock in response to contention, as this vCPU is 4414d02c357eSSean Christopherson * *guaranteed* to need to retry, i.e. waiting until mmu_lock is held 4415d02c357eSSean Christopherson * to detect retry guarantees the worst case latency for the vCPU. 4416d02c357eSSean Christopherson */ 4417f6adeae8SSean Christopherson if (mmu_invalidate_retry_gfn_unsafe(vcpu->kvm, fault->mmu_seq, fault->gfn)) 4418d02c357eSSean Christopherson return RET_PF_RETRY; 4419d02c357eSSean Christopherson 442056c3a4e4SDavid Matlack ret = __kvm_faultin_pfn(vcpu, fault); 442156c3a4e4SDavid Matlack if (ret != RET_PF_CONTINUE) 442256c3a4e4SDavid Matlack return ret; 442356c3a4e4SDavid Matlack 442456c3a4e4SDavid Matlack if (unlikely(is_error_pfn(fault->pfn))) 4425cd08d178SDavid Matlack return kvm_handle_error_pfn(vcpu, fault); 442656c3a4e4SDavid Matlack 4427*2b1f4355SSean Christopherson if (WARN_ON_ONCE(!fault->slot || is_noslot_pfn(fault->pfn))) 4428354c908cSDavid Matlack return kvm_handle_noslot_fault(vcpu, fault, access); 4429354c908cSDavid Matlack 4430d02c357eSSean Christopherson /* 4431d02c357eSSean Christopherson * Check again for a relevant mmu_notifier invalidation event purely to 4432d02c357eSSean Christopherson * avoid contending mmu_lock. Most invalidations will be detected by 4433d02c357eSSean Christopherson * the previous check, but checking is extremely cheap relative to the 4434d02c357eSSean Christopherson * overall cost of failing to detect the invalidation until after 4435d02c357eSSean Christopherson * mmu_lock is acquired. 4436d02c357eSSean Christopherson */ 4437d02c357eSSean Christopherson if (mmu_invalidate_retry_gfn_unsafe(vcpu->kvm, fault->mmu_seq, fault->gfn)) { 4438d02c357eSSean Christopherson kvm_release_pfn_clean(fault->pfn); 4439d02c357eSSean Christopherson return RET_PF_RETRY; 4440d02c357eSSean Christopherson } 4441d02c357eSSean Christopherson 444256c3a4e4SDavid Matlack return RET_PF_CONTINUE; 4443ba6e3fe2SDavid Matlack } 4444ba6e3fe2SDavid Matlack 4445a955cad8SSean Christopherson /* 4446a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4447a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4448a955cad8SSean Christopherson */ 4449a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4450ba6e3fe2SDavid Matlack struct kvm_page_fault *fault) 4451a955cad8SSean Christopherson { 4452c5f2d564SSean Christopherson struct kvm_mmu_page *sp = root_to_sp(vcpu->arch.mmu->root.hpa); 445318c841e1SSean Christopherson 445418c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 445518c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 445618c841e1SSean Christopherson return true; 445718c841e1SSean Christopherson 445818c841e1SSean Christopherson /* 445918c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 446018c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 446118c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 446218c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 446318c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 446418c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 446518c841e1SSean Christopherson */ 4466527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4467a955cad8SSean Christopherson return true; 4468a955cad8SSean Christopherson 4469d02c357eSSean Christopherson /* 4470d02c357eSSean Christopherson * Check for a relevant mmu_notifier invalidation event one last time 4471d02c357eSSean Christopherson * now that mmu_lock is held, as the "unsafe" checks performed without 4472d02c357eSSean Christopherson * holding mmu_lock can get false negatives. 4473d02c357eSSean Christopherson */ 4474a955cad8SSean Christopherson return fault->slot && 44758569992dSChao Peng mmu_invalidate_retry_gfn(vcpu->kvm, fault->mmu_seq, fault->gfn); 4476a955cad8SSean Christopherson } 4477a955cad8SSean Christopherson 44784326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4479c50d8ae3SPaolo Bonzini { 448083f06fa7SSean Christopherson int r; 4481c50d8ae3SPaolo Bonzini 44820e3223d8SSean Christopherson /* Dummy roots are used only for shadowing bad guest roots. */ 44830e3223d8SSean Christopherson if (WARN_ON_ONCE(kvm_mmu_is_dummy_root(vcpu->arch.mmu->root.hpa))) 44840e3223d8SSean Christopherson return RET_PF_RETRY; 44850e3223d8SSean Christopherson 4486b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4487c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4488c50d8ae3SPaolo Bonzini 44893c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4490c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4491c4371c2aSSean Christopherson return r; 449283291445SSean Christopherson 4493378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4494c50d8ae3SPaolo Bonzini if (r) 4495c50d8ae3SPaolo Bonzini return r; 4496c50d8ae3SPaolo Bonzini 4497354c908cSDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 44985276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4499367fd790SSean Christopherson return r; 4500367fd790SSean Christopherson 4501367fd790SSean Christopherson r = RET_PF_RETRY; 4502531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4503a2855afcSBen Gardon 4504ba6e3fe2SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 4505367fd790SSean Christopherson goto out_unlock; 4506a955cad8SSean Christopherson 45077bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 45087bd7ded6SSean Christopherson if (r) 4509367fd790SSean Christopherson goto out_unlock; 4510bb18842eSBen Gardon 45116c882ef4SDavid Matlack r = direct_map(vcpu, fault); 45120f90e1c1SSean Christopherson 4513367fd790SSean Christopherson out_unlock: 4514531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 45153647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4516367fd790SSean Christopherson return r; 4517c50d8ae3SPaolo Bonzini } 4518c50d8ae3SPaolo Bonzini 4519c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4520c501040aSPaolo Bonzini struct kvm_page_fault *fault) 45210f90e1c1SSean Christopherson { 45220f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 45234326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 45244326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 45250f90e1c1SSean Christopherson } 45260f90e1c1SSean Christopherson 4527c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4528c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4529c50d8ae3SPaolo Bonzini { 4530c50d8ae3SPaolo Bonzini int r = 1; 45319ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4532c50d8ae3SPaolo Bonzini 4533736c291cSSean Christopherson #ifndef CONFIG_X86_64 4534736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4535736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4536736c291cSSean Christopherson return -EFAULT; 4537736c291cSSean Christopherson #endif 45387bdbb820SSean Christopherson /* 45397bdbb820SSean Christopherson * Legacy #PF exception only have a 32-bit error code. Simply drop the 45407bdbb820SSean Christopherson * upper bits as KVM doesn't use them for #PF (because they are never 45417bdbb820SSean Christopherson * set), and to ensure there are no collisions with KVM-defined bits. 45427bdbb820SSean Christopherson */ 45437bdbb820SSean Christopherson if (WARN_ON_ONCE(error_code >> 32)) 45447bdbb820SSean Christopherson error_code = lower_32_bits(error_code); 4545736c291cSSean Christopherson 4546dee281e4SSean Christopherson /* Ensure the above sanity check also covers KVM-defined flags. */ 4547dee281e4SSean Christopherson BUILD_BUG_ON(lower_32_bits(PFERR_SYNTHETIC_MASK)); 4548dee281e4SSean Christopherson 4549c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 45509ce372b3SVitaly Kuznetsov if (!flags) { 4551faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4552c50d8ae3SPaolo Bonzini 4553c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4554c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4555c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4556c50d8ae3SPaolo Bonzini insn_len); 45579ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 455868fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4559c50d8ae3SPaolo Bonzini local_irq_disable(); 45606bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4561c50d8ae3SPaolo Bonzini local_irq_enable(); 45629ce372b3SVitaly Kuznetsov } else { 45639ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4564c50d8ae3SPaolo Bonzini } 45659ce372b3SVitaly Kuznetsov 4566c50d8ae3SPaolo Bonzini return r; 4567c50d8ae3SPaolo Bonzini } 4568c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4569c50d8ae3SPaolo Bonzini 45709aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 45719aa8ab43SDavid Matlack static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, 45729aa8ab43SDavid Matlack struct kvm_page_fault *fault) 45739aa8ab43SDavid Matlack { 45749aa8ab43SDavid Matlack int r; 45759aa8ab43SDavid Matlack 45769aa8ab43SDavid Matlack if (page_fault_handle_page_track(vcpu, fault)) 45779aa8ab43SDavid Matlack return RET_PF_EMULATE; 45789aa8ab43SDavid Matlack 45799aa8ab43SDavid Matlack r = fast_page_fault(vcpu, fault); 45809aa8ab43SDavid Matlack if (r != RET_PF_INVALID) 45819aa8ab43SDavid Matlack return r; 45829aa8ab43SDavid Matlack 45839aa8ab43SDavid Matlack r = mmu_topup_memory_caches(vcpu, false); 45849aa8ab43SDavid Matlack if (r) 45859aa8ab43SDavid Matlack return r; 45869aa8ab43SDavid Matlack 45879aa8ab43SDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 45889aa8ab43SDavid Matlack if (r != RET_PF_CONTINUE) 45899aa8ab43SDavid Matlack return r; 45909aa8ab43SDavid Matlack 45919aa8ab43SDavid Matlack r = RET_PF_RETRY; 45929aa8ab43SDavid Matlack read_lock(&vcpu->kvm->mmu_lock); 45939aa8ab43SDavid Matlack 45949aa8ab43SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 45959aa8ab43SDavid Matlack goto out_unlock; 45969aa8ab43SDavid Matlack 45979aa8ab43SDavid Matlack r = kvm_tdp_mmu_map(vcpu, fault); 45989aa8ab43SDavid Matlack 45999aa8ab43SDavid Matlack out_unlock: 46009aa8ab43SDavid Matlack read_unlock(&vcpu->kvm->mmu_lock); 46019aa8ab43SDavid Matlack kvm_release_pfn_clean(fault->pfn); 46029aa8ab43SDavid Matlack return r; 46039aa8ab43SDavid Matlack } 46049aa8ab43SDavid Matlack #endif 46059aa8ab43SDavid Matlack 46061affe455SYan Zhao bool __kvm_mmu_honors_guest_mtrrs(bool vm_has_noncoherent_dma) 46071affe455SYan Zhao { 46081affe455SYan Zhao /* 46091affe455SYan Zhao * If host MTRRs are ignored (shadow_memtype_mask is non-zero), and the 46101affe455SYan Zhao * VM has non-coherent DMA (DMA doesn't snoop CPU caches), KVM's ABI is 46111affe455SYan Zhao * to honor the memtype from the guest's MTRRs so that guest accesses 46121affe455SYan Zhao * to memory that is DMA'd aren't cached against the guest's wishes. 46131affe455SYan Zhao * 46141affe455SYan Zhao * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 46151affe455SYan Zhao * e.g. KVM will force UC memtype for host MMIO. 46161affe455SYan Zhao */ 46171affe455SYan Zhao return vm_has_noncoherent_dma && shadow_memtype_mask; 46181affe455SYan Zhao } 46191affe455SYan Zhao 4620c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4621c50d8ae3SPaolo Bonzini { 4622d5e90a69SSean Christopherson /* 4623d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4624d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 46251affe455SYan Zhao * across the entire mapping. 4626d5e90a69SSean Christopherson */ 46271affe455SYan Zhao if (kvm_mmu_honors_guest_mtrrs(vcpu->kvm)) { 4628d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 46294326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 4630c667a3baSHou Wenlong gfn_t base = gfn_round_for_level(fault->gfn, 4631c667a3baSHou Wenlong fault->max_level); 4632c50d8ae3SPaolo Bonzini 4633cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4634cb9b88c6SSean Christopherson break; 4635d5e90a69SSean Christopherson } 4636c50d8ae3SPaolo Bonzini } 4637c50d8ae3SPaolo Bonzini 46389aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 46399aa8ab43SDavid Matlack if (tdp_mmu_enabled) 46409aa8ab43SDavid Matlack return kvm_tdp_mmu_page_fault(vcpu, fault); 46419aa8ab43SDavid Matlack #endif 46429aa8ab43SDavid Matlack 46434326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4644c50d8ae3SPaolo Bonzini } 4645c50d8ae3SPaolo Bonzini 464684a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4647c50d8ae3SPaolo Bonzini { 4648c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4649c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4650c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 4651c50d8ae3SPaolo Bonzini } 4652c50d8ae3SPaolo Bonzini 4653be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 46540be44352SSean Christopherson union kvm_mmu_page_role role) 46550be44352SSean Christopherson { 4656c30e000eSSean Christopherson struct kvm_mmu_page *sp; 4657c30e000eSSean Christopherson 4658c30e000eSSean Christopherson if (!VALID_PAGE(root->hpa)) 4659c30e000eSSean Christopherson return false; 4660c30e000eSSean Christopherson 4661c30e000eSSean Christopherson if (!role.direct && pgd != root->pgd) 4662c30e000eSSean Christopherson return false; 4663c30e000eSSean Christopherson 4664c30e000eSSean Christopherson sp = root_to_sp(root->hpa); 4665c30e000eSSean Christopherson if (WARN_ON_ONCE(!sp)) 4666c30e000eSSean Christopherson return false; 4667c30e000eSSean Christopherson 4668c30e000eSSean Christopherson return role.word == sp->role.word; 46690be44352SSean Christopherson } 46700be44352SSean Christopherson 4671c50d8ae3SPaolo Bonzini /* 46725499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 46735499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 46745499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 46755499ea73SPaolo Bonzini * true is returned. 46765499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 46775499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4678c50d8ae3SPaolo Bonzini */ 46795499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 46805499ea73SPaolo Bonzini gpa_t new_pgd, 4681c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4682c50d8ae3SPaolo Bonzini { 4683c50d8ae3SPaolo Bonzini uint i; 4684c50d8ae3SPaolo Bonzini 4685b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 46860be44352SSean Christopherson return true; 46870be44352SSean Christopherson 4688c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 46895499ea73SPaolo Bonzini /* 46905499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 46915499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 46925499ea73SPaolo Bonzini * 0 C 1 2 3 46935499ea73SPaolo Bonzini * 1 C 0 2 3 46945499ea73SPaolo Bonzini * 2 C 0 1 3 46955499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 46965499ea73SPaolo Bonzini */ 4697b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4698b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 46995499ea73SPaolo Bonzini return true; 4700c50d8ae3SPaolo Bonzini } 4701c50d8ae3SPaolo Bonzini 47025499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 47035499ea73SPaolo Bonzini return false; 4704c50d8ae3SPaolo Bonzini } 4705c50d8ae3SPaolo Bonzini 4706c50d8ae3SPaolo Bonzini /* 47075499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 47085499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 47095499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 47105499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 47115499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 47125499ea73SPaolo Bonzini */ 47135499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 47145499ea73SPaolo Bonzini gpa_t new_pgd, 47155499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 47165499ea73SPaolo Bonzini { 47175499ea73SPaolo Bonzini uint i; 47185499ea73SPaolo Bonzini 47195499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 47205499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 47215499ea73SPaolo Bonzini goto hit; 47225499ea73SPaolo Bonzini 47235499ea73SPaolo Bonzini return false; 47245499ea73SPaolo Bonzini 47255499ea73SPaolo Bonzini hit: 47265499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 47275499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 47285499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 47295499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 47305499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 47315499ea73SPaolo Bonzini return true; 47325499ea73SPaolo Bonzini } 47335499ea73SPaolo Bonzini 47345499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 47355499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 47365499ea73SPaolo Bonzini { 47375499ea73SPaolo Bonzini /* 47380e3223d8SSean Christopherson * Limit reuse to 64-bit hosts+VMs without "special" roots in order to 47390e3223d8SSean Christopherson * avoid having to deal with PDPTEs and other complexities. 4740c50d8ae3SPaolo Bonzini */ 4741c5f2d564SSean Christopherson if (VALID_PAGE(mmu->root.hpa) && !root_to_sp(mmu->root.hpa)) 47425499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4743c50d8ae3SPaolo Bonzini 47445499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 47455499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 47465499ea73SPaolo Bonzini else 47475499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4748c50d8ae3SPaolo Bonzini } 4749c50d8ae3SPaolo Bonzini 4750d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4751c50d8ae3SPaolo Bonzini { 47520c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 47537a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 47540c1c92f1SPaolo Bonzini 4755a7e48ef7SWei Liu /* 4756a7e48ef7SWei Liu * Return immediately if no usable root was found, kvm_mmu_reload() 4757a7e48ef7SWei Liu * will establish a valid root prior to the next VM-Enter. 4758a7e48ef7SWei Liu */ 4759a7e48ef7SWei Liu if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) 4760b869855bSSean Christopherson return; 4761c50d8ae3SPaolo Bonzini 4762c50d8ae3SPaolo Bonzini /* 4763b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4764b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4765527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4766527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4767b869855bSSean Christopherson */ 4768b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4769b869855bSSean Christopherson 4770b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4771b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4772b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4773b5129100SSean Christopherson } 4774b869855bSSean Christopherson 4775b869855bSSean Christopherson /* 4776b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4777b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4778b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4779b869855bSSean Christopherson * the shadow page tables. 4780c50d8ae3SPaolo Bonzini */ 4781c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4782c50d8ae3SPaolo Bonzini 4783daa5b6c1SBen Gardon /* 4784daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4785daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4786daa5b6c1SBen Gardon */ 4787c30e000eSSean Christopherson if (!new_role.direct) { 4788c30e000eSSean Christopherson struct kvm_mmu_page *sp = root_to_sp(vcpu->arch.mmu->root.hpa); 4789c30e000eSSean Christopherson 4790c30e000eSSean Christopherson if (!WARN_ON_ONCE(!sp)) 4791c30e000eSSean Christopherson __clear_sp_write_flooding_count(sp); 4792c30e000eSSean Christopherson } 4793c50d8ae3SPaolo Bonzini } 4794be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4795c50d8ae3SPaolo Bonzini 4796c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4797c3e5e415SLai Jiangshan unsigned int access) 4798c50d8ae3SPaolo Bonzini { 4799c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4800c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4801c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4802c50d8ae3SPaolo Bonzini return true; 4803c50d8ae3SPaolo Bonzini } 4804c50d8ae3SPaolo Bonzini 4805c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4806c50d8ae3SPaolo Bonzini return true; 4807c50d8ae3SPaolo Bonzini } 4808c50d8ae3SPaolo Bonzini 4809c50d8ae3SPaolo Bonzini return false; 4810c50d8ae3SPaolo Bonzini } 4811c50d8ae3SPaolo Bonzini 4812c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4813c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4814c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4815c50d8ae3SPaolo Bonzini #undef PTTYPE 4816c50d8ae3SPaolo Bonzini 4817c50d8ae3SPaolo Bonzini #define PTTYPE 64 4818c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4819c50d8ae3SPaolo Bonzini #undef PTTYPE 4820c50d8ae3SPaolo Bonzini 4821c50d8ae3SPaolo Bonzini #define PTTYPE 32 4822c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4823c50d8ae3SPaolo Bonzini #undef PTTYPE 4824c50d8ae3SPaolo Bonzini 4825f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 4826f3d90f90SSean Christopherson u64 pa_bits_rsvd, int level, bool nx, 4827f3d90f90SSean Christopherson bool gbpages, bool pse, bool amd) 4828c50d8ae3SPaolo Bonzini { 4829c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4830c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 48315b7f575cSSean Christopherson u64 high_bits_rsvd; 4832c50d8ae3SPaolo Bonzini 4833c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4834c50d8ae3SPaolo Bonzini 4835c50d8ae3SPaolo Bonzini if (!gbpages) 4836c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4837c50d8ae3SPaolo Bonzini 48385b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 48395b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 48405b7f575cSSean Christopherson else 48415b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 48425b7f575cSSean Christopherson 48435b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 48445b7f575cSSean Christopherson if (!nx) 48455b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 48465b7f575cSSean Christopherson 4847c50d8ae3SPaolo Bonzini /* 4848c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4849c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4850c50d8ae3SPaolo Bonzini */ 4851c50d8ae3SPaolo Bonzini if (amd) 4852c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4853c50d8ae3SPaolo Bonzini 4854c50d8ae3SPaolo Bonzini switch (level) { 4855c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4856c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4857c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4858c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4859c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4860c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4861c50d8ae3SPaolo Bonzini 4862c50d8ae3SPaolo Bonzini if (!pse) { 4863c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4864c50d8ae3SPaolo Bonzini break; 4865c50d8ae3SPaolo Bonzini } 4866c50d8ae3SPaolo Bonzini 4867c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4868c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4869c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4870c50d8ae3SPaolo Bonzini else 4871c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4872c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4873c50d8ae3SPaolo Bonzini break; 4874c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 48755b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 48765b7f575cSSean Christopherson high_bits_rsvd | 48775b7f575cSSean Christopherson rsvd_bits(5, 8) | 48785b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 48795b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 48805b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 48815b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4882c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4883c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4884c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4885c50d8ae3SPaolo Bonzini break; 4886c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 48875b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 48885b7f575cSSean Christopherson nonleaf_bit8_rsvd | 48895b7f575cSSean Christopherson rsvd_bits(7, 7); 4890c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4891c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4892df561f66SGustavo A. R. Silva fallthrough; 4893c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 48945b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 48955b7f575cSSean Christopherson nonleaf_bit8_rsvd | 48965b7f575cSSean Christopherson rsvd_bits(7, 7); 48975b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 48985b7f575cSSean Christopherson gbpages_bit_rsvd; 48995b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 49005b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4901c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4902c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 49035b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 49045b7f575cSSean Christopherson gbpages_bit_rsvd | 4905c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 49065b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4907c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4908c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4909c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4910c50d8ae3SPaolo Bonzini break; 4911c50d8ae3SPaolo Bonzini } 4912c50d8ae3SPaolo Bonzini } 4913c50d8ae3SPaolo Bonzini 4914c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4915c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4916c50d8ae3SPaolo Bonzini { 4917b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 49185b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 49194d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 4920ccf31d6eSSean Christopherson guest_can_use(vcpu, X86_FEATURE_GBPAGES), 49214e9c0d80SSean Christopherson is_cr4_pse(context), 492223493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4923c50d8ae3SPaolo Bonzini } 4924c50d8ae3SPaolo Bonzini 4925f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 4926f3d90f90SSean Christopherson u64 pa_bits_rsvd, bool execonly, 4927f3d90f90SSean Christopherson int huge_page_level) 4928c50d8ae3SPaolo Bonzini { 49295b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 493084ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4931c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4932c50d8ae3SPaolo Bonzini 493384ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 493484ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 493584ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 493684ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 493784ea5c09SLai Jiangshan 49385b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 49395b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 494084ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 494184ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 49425b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4943c50d8ae3SPaolo Bonzini 4944c50d8ae3SPaolo Bonzini /* large page */ 4945c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4946c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 494784ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 494884ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4949c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4950c50d8ae3SPaolo Bonzini 4951c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4952c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4953c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4954c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4955c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4956c50d8ae3SPaolo Bonzini if (!execonly) { 4957c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4958c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4959c50d8ae3SPaolo Bonzini } 4960c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4961c50d8ae3SPaolo Bonzini } 4962c50d8ae3SPaolo Bonzini 4963c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 496484ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4965c50d8ae3SPaolo Bonzini { 4966c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 496784ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 496884ea5c09SLai Jiangshan huge_page_level); 4969c50d8ae3SPaolo Bonzini } 4970c50d8ae3SPaolo Bonzini 49716f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 49726f8e65a6SSean Christopherson { 49736f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 49746f8e65a6SSean Christopherson } 49756f8e65a6SSean Christopherson 4976c50d8ae3SPaolo Bonzini /* 4977c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4978c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4979c50d8ae3SPaolo Bonzini * follow the features in guest. 4980c50d8ae3SPaolo Bonzini */ 498116be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 498216be1d12SSean Christopherson struct kvm_mmu *context) 4983c50d8ae3SPaolo Bonzini { 49848c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 49858c985b2dSSean Christopherson bool is_amd = true; 49868c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 49878c985b2dSSean Christopherson bool is_pse = false; 4988c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4989c50d8ae3SPaolo Bonzini int i; 4990c50d8ae3SPaolo Bonzini 4991a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 49928c985b2dSSean Christopherson 4993c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4994b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4995a972e29cSPaolo Bonzini context->root_role.level, 49967a458f0eSPaolo Bonzini context->root_role.efer_nx, 4997ccf31d6eSSean Christopherson guest_can_use(vcpu, X86_FEATURE_GBPAGES), 4998ccf31d6eSSean Christopherson is_pse, is_amd); 4999c50d8ae3SPaolo Bonzini 5000c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 5001c50d8ae3SPaolo Bonzini return; 5002c50d8ae3SPaolo Bonzini 5003a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 5004e54f1ff2SKai Huang /* 5005e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 5006e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 5007e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 5008e54f1ff2SKai Huang * not allowed to be set. 5009e54f1ff2SKai Huang */ 5010e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 5011e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 5012e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 5013e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 5014c50d8ae3SPaolo Bonzini } 5015c50d8ae3SPaolo Bonzini 5016c50d8ae3SPaolo Bonzini } 5017c50d8ae3SPaolo Bonzini 5018c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 5019c50d8ae3SPaolo Bonzini { 5020c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 5021c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 5022c50d8ae3SPaolo Bonzini } 5023c50d8ae3SPaolo Bonzini 5024c50d8ae3SPaolo Bonzini /* 5025c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 5026c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 5027c50d8ae3SPaolo Bonzini */ 5028f3d90f90SSean Christopherson static void reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 5029c50d8ae3SPaolo Bonzini { 5030c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 5031c50d8ae3SPaolo Bonzini int i; 5032c50d8ae3SPaolo Bonzini 5033c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 5034c50d8ae3SPaolo Bonzini 5035c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 5036b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 50376c6ab524SSean Christopherson context->root_role.level, true, 5038c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 50398c985b2dSSean Christopherson false, true); 5040c50d8ae3SPaolo Bonzini else 5041c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 504284ea5c09SLai Jiangshan reserved_hpa_bits(), false, 504384ea5c09SLai Jiangshan max_huge_page_level); 5044c50d8ae3SPaolo Bonzini 5045c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 5046c50d8ae3SPaolo Bonzini return; 5047c50d8ae3SPaolo Bonzini 5048a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 5049c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 5050c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 5051c50d8ae3SPaolo Bonzini } 5052c50d8ae3SPaolo Bonzini } 5053c50d8ae3SPaolo Bonzini 5054c50d8ae3SPaolo Bonzini /* 5055c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 5056c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 5057c50d8ae3SPaolo Bonzini */ 5058c50d8ae3SPaolo Bonzini static void 5059e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 5060c50d8ae3SPaolo Bonzini { 5061c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 506284ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 506384ea5c09SLai Jiangshan max_huge_page_level); 5064c50d8ae3SPaolo Bonzini } 5065c50d8ae3SPaolo Bonzini 5066c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 5067c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 5068c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 5069c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 5070c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 5071c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 5072c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 5073c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 5074c50d8ae3SPaolo Bonzini 5075c50d8ae3SPaolo Bonzini 5076c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 5077c50d8ae3SPaolo Bonzini { 5078c50d8ae3SPaolo Bonzini unsigned byte; 5079c50d8ae3SPaolo Bonzini 5080c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 5081c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 5082c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 5083c50d8ae3SPaolo Bonzini 5084c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 5085c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 5086c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 508790599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 5088c50d8ae3SPaolo Bonzini 5089c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 5090c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 5091c50d8ae3SPaolo Bonzini 5092c50d8ae3SPaolo Bonzini /* 5093c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 5094c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 5095c50d8ae3SPaolo Bonzini */ 5096c50d8ae3SPaolo Bonzini 5097c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 5098c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 5099c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 5100c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 5101c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 5102c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 5103c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 5104c50d8ae3SPaolo Bonzini u8 smepf = 0; 5105c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 5106c50d8ae3SPaolo Bonzini u8 smapf = 0; 5107c50d8ae3SPaolo Bonzini 5108c50d8ae3SPaolo Bonzini if (!ept) { 5109c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 5110c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 5111c50d8ae3SPaolo Bonzini 5112c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 511390599c28SSean Christopherson if (!efer_nx) 5114c50d8ae3SPaolo Bonzini ff = 0; 5115c50d8ae3SPaolo Bonzini 5116c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 5117c50d8ae3SPaolo Bonzini if (!cr0_wp) 5118c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 5119c50d8ae3SPaolo Bonzini 5120c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 5121c50d8ae3SPaolo Bonzini if (cr4_smep) 5122c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 5123c50d8ae3SPaolo Bonzini 5124c50d8ae3SPaolo Bonzini /* 5125c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 5126c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 5127c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 5128c50d8ae3SPaolo Bonzini * conditions are true: 5129c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 5130c50d8ae3SPaolo Bonzini * - A user page is accessed 5131c50d8ae3SPaolo Bonzini * - The access is not a fetch 51324f4aa80eSLai Jiangshan * - The access is supervisor mode 51334f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 5134c50d8ae3SPaolo Bonzini * 513594b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 513694b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 5137c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 5138c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 5139c50d8ae3SPaolo Bonzini */ 5140c50d8ae3SPaolo Bonzini if (cr4_smap) 5141c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 5142c50d8ae3SPaolo Bonzini } 5143c50d8ae3SPaolo Bonzini 5144c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 5145c50d8ae3SPaolo Bonzini } 5146c50d8ae3SPaolo Bonzini } 5147c50d8ae3SPaolo Bonzini 5148c50d8ae3SPaolo Bonzini /* 5149c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 5150c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 5151c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 5152c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 5153c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 5154c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 5155c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 5156c50d8ae3SPaolo Bonzini * 5157c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 5158c50d8ae3SPaolo Bonzini * page tables and the machine state: 5159c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 5160c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 5161c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 5162c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 5163c50d8ae3SPaolo Bonzini * 5164c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 5165c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 5166c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 5167c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 5168c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 5169c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 5170c50d8ae3SPaolo Bonzini * only will be masked away. 5171c50d8ae3SPaolo Bonzini */ 51722e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 5173c50d8ae3SPaolo Bonzini { 5174c50d8ae3SPaolo Bonzini unsigned bit; 5175c50d8ae3SPaolo Bonzini bool wp; 5176c50d8ae3SPaolo Bonzini 5177c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 5178a3ca5281SChenyi Qiang 5179a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 5180c50d8ae3SPaolo Bonzini return; 5181c50d8ae3SPaolo Bonzini 51822e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 5183c50d8ae3SPaolo Bonzini 5184c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 5185c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 5186c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 5187c50d8ae3SPaolo Bonzini 5188c50d8ae3SPaolo Bonzini pfec = bit << 1; 5189c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 5190c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 5191c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 5192c50d8ae3SPaolo Bonzini 5193c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 5194c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 5195c50d8ae3SPaolo Bonzini 5196c50d8ae3SPaolo Bonzini /* 5197c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 5198c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 5199c50d8ae3SPaolo Bonzini */ 5200c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 5201c50d8ae3SPaolo Bonzini /* 5202c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 5203c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 5204c50d8ae3SPaolo Bonzini */ 5205c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 5206c50d8ae3SPaolo Bonzini 5207c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 5208c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 5209c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 5210c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 5211c50d8ae3SPaolo Bonzini 5212c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 5213c50d8ae3SPaolo Bonzini } 5214c50d8ae3SPaolo Bonzini } 5215c50d8ae3SPaolo Bonzini 5216533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 5217533f9a4bSSean Christopherson struct kvm_mmu *mmu) 5218c50d8ae3SPaolo Bonzini { 5219533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 5220533f9a4bSSean Christopherson return; 5221c50d8ae3SPaolo Bonzini 5222c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 5223533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 5224533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 5225c50d8ae3SPaolo Bonzini } 5226c50d8ae3SPaolo Bonzini 5227fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 5228c50d8ae3SPaolo Bonzini { 5229c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 5230c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5231c3c6c9fcSLai Jiangshan context->sync_spte = paging64_sync_spte; 5232c50d8ae3SPaolo Bonzini } 5233c50d8ae3SPaolo Bonzini 523484a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 5235c50d8ae3SPaolo Bonzini { 5236c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 5237c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5238c3c6c9fcSLai Jiangshan context->sync_spte = paging32_sync_spte; 5239c50d8ae3SPaolo Bonzini } 5240c50d8ae3SPaolo Bonzini 5241f3d90f90SSean Christopherson static union kvm_cpu_role kvm_calc_cpu_role(struct kvm_vcpu *vcpu, 5242f3d90f90SSean Christopherson const struct kvm_mmu_role_regs *regs) 5243e5ed0fb0SPaolo Bonzini { 52447a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5245e5ed0fb0SPaolo Bonzini 5246e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 5247e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 5248e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 5249e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 5250e5ed0fb0SPaolo Bonzini 5251e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 5252e5ed0fb0SPaolo Bonzini role.base.direct = 1; 5253e5ed0fb0SPaolo Bonzini return role; 5254e5ed0fb0SPaolo Bonzini } 5255e5ed0fb0SPaolo Bonzini 5256e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 5257e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 5258e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 5259e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 5260e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 526160f3cb60SPaolo Bonzini 526260f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 526360f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 526460f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 526560f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 526660f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 526760f3cb60SPaolo Bonzini else 526860f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 5269e5ed0fb0SPaolo Bonzini 5270e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 5271e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 5272e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 5273e5ed0fb0SPaolo Bonzini 5274e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 5275e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 5276e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 5277e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 5278e5ed0fb0SPaolo Bonzini return role; 5279e5ed0fb0SPaolo Bonzini } 5280e5ed0fb0SPaolo Bonzini 5281cf9f4c0eSSean Christopherson void __kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu, 5282cf9f4c0eSSean Christopherson struct kvm_mmu *mmu) 5283cf9f4c0eSSean Christopherson { 5284cf9f4c0eSSean Christopherson const bool cr0_wp = kvm_is_cr0_bit_set(vcpu, X86_CR0_WP); 5285cf9f4c0eSSean Christopherson 5286cf9f4c0eSSean Christopherson BUILD_BUG_ON((KVM_MMU_CR0_ROLE_BITS & KVM_POSSIBLE_CR0_GUEST_BITS) != X86_CR0_WP); 5287cf9f4c0eSSean Christopherson BUILD_BUG_ON((KVM_MMU_CR4_ROLE_BITS & KVM_POSSIBLE_CR4_GUEST_BITS)); 5288cf9f4c0eSSean Christopherson 5289cf9f4c0eSSean Christopherson if (is_cr0_wp(mmu) == cr0_wp) 5290cf9f4c0eSSean Christopherson return; 5291cf9f4c0eSSean Christopherson 5292cf9f4c0eSSean Christopherson mmu->cpu_role.base.cr0_wp = cr0_wp; 5293cf9f4c0eSSean Christopherson reset_guest_paging_metadata(vcpu, mmu); 5294cf9f4c0eSSean Christopherson } 5295cf9f4c0eSSean Christopherson 5296d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 5297d468d94bSSean Christopherson { 5298746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5299746700d2SWei Huang if (tdp_root_level) 5300746700d2SWei Huang return tdp_root_level; 5301746700d2SWei Huang 5302d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 530383013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5304d468d94bSSean Christopherson return 4; 5305d468d94bSSean Christopherson 530683013059SSean Christopherson return max_tdp_level; 5307d468d94bSSean Christopherson } 5308d468d94bSSean Christopherson 53097a458f0eSPaolo Bonzini static union kvm_mmu_page_role 53108626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 53117a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5312c50d8ae3SPaolo Bonzini { 53137a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5314c50d8ae3SPaolo Bonzini 53157a458f0eSPaolo Bonzini role.access = ACC_ALL; 53167a458f0eSPaolo Bonzini role.cr0_wp = true; 53177a458f0eSPaolo Bonzini role.efer_nx = true; 53187a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 53197a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 532054275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 53217a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 53227a458f0eSPaolo Bonzini role.direct = true; 53237a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5324c50d8ae3SPaolo Bonzini 5325c50d8ae3SPaolo Bonzini return role; 5326c50d8ae3SPaolo Bonzini } 5327c50d8ae3SPaolo Bonzini 532839e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5329a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5330c50d8ae3SPaolo Bonzini { 53318c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 53327a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5333c50d8ae3SPaolo Bonzini 5334e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 53357a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5336c50d8ae3SPaolo Bonzini return; 5337c50d8ae3SPaolo Bonzini 5338e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 53397a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 53407a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5341c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 53422fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5343c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5344c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5345c50d8ae3SPaolo Bonzini 534636f26787SSean Christopherson if (!is_cr0_pg(context)) 5347c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 534836f26787SSean Christopherson else if (is_cr4_pae(context)) 5349c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5350f4bd6f73SSean Christopherson else 5351c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5352c50d8ae3SPaolo Bonzini 5353533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5354e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5355c50d8ae3SPaolo Bonzini } 5356c50d8ae3SPaolo Bonzini 53578c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 53587a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 53597a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5360c50d8ae3SPaolo Bonzini { 5361e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 53627a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 536318db1b17SSean Christopherson return; 5364c50d8ae3SPaolo Bonzini 5365e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 53667a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 536718db1b17SSean Christopherson 536836f26787SSean Christopherson if (!is_cr0_pg(context)) 536984a16226SSean Christopherson nonpaging_init_context(context); 537036f26787SSean Christopherson else if (is_cr4_pae(context)) 5371fe660f72SSean Christopherson paging64_init_context(context); 5372c50d8ae3SPaolo Bonzini else 537384a16226SSean Christopherson paging32_init_context(context); 5374c50d8ae3SPaolo Bonzini 5375533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5376c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5377c50d8ae3SPaolo Bonzini } 53780f04a2acSVitaly Kuznetsov 5379594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5380a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 53810f04a2acSVitaly Kuznetsov { 53828c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 538356b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 538456b321f9SPaolo Bonzini 538556b321f9SPaolo Bonzini root_role = cpu_role.base; 538656b321f9SPaolo Bonzini 538756b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 538856b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 538956b321f9SPaolo Bonzini 539056b321f9SPaolo Bonzini /* 539156b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 539256b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 539356b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 539456b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 539556b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 539656b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 539756b321f9SPaolo Bonzini * MMU contexts. 539856b321f9SPaolo Bonzini */ 539956b321f9SPaolo Bonzini root_role.efer_nx = true; 54000f04a2acSVitaly Kuznetsov 54017a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 54020f04a2acSVitaly Kuznetsov } 54030f04a2acSVitaly Kuznetsov 5404dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5405dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 54060f04a2acSVitaly Kuznetsov { 54078c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5408594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5409594e91a1SSean Christopherson .cr0 = cr0, 541028f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5411594e91a1SSean Christopherson .efer = efer, 5412594e91a1SSean Christopherson }; 54137a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 541456b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 541556b321f9SPaolo Bonzini 541656b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 541756b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 541856b321f9SPaolo Bonzini 541956b321f9SPaolo Bonzini root_role = cpu_role.base; 542056b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 542184e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 542284e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 542384e5ffd0SLai Jiangshan root_role.passthrough = 1; 54240f04a2acSVitaly Kuznetsov 54257a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5426d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 54270f04a2acSVitaly Kuznetsov } 54280f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5429c50d8ae3SPaolo Bonzini 54307a7ae829SPaolo Bonzini static union kvm_cpu_role 5431c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5432bb1fcc70SSean Christopherson bool execonly, u8 level) 5433c50d8ae3SPaolo Bonzini { 54347a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5435c50d8ae3SPaolo Bonzini 5436daed87b8SPaolo Bonzini /* 5437daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5438daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5439daed87b8SPaolo Bonzini */ 5440daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5441bb1fcc70SSean Christopherson role.base.level = level; 5442bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5443c50d8ae3SPaolo Bonzini role.base.direct = false; 5444c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5445c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5446c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5447c50d8ae3SPaolo Bonzini 5448cd6767c3SSean Christopherson role.ext.word = 0; 5449c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5450cd6767c3SSean Christopherson role.ext.valid = 1; 5451c50d8ae3SPaolo Bonzini 5452c50d8ae3SPaolo Bonzini return role; 5453c50d8ae3SPaolo Bonzini } 5454c50d8ae3SPaolo Bonzini 5455c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5456cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5457cc022ae1SLai Jiangshan gpa_t new_eptp) 5458c50d8ae3SPaolo Bonzini { 54598c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5460bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 54617a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5462c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5463bb1fcc70SSean Christopherson execonly, level); 5464c50d8ae3SPaolo Bonzini 5465e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5466e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5467e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 54687a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 546918db1b17SSean Christopherson 5470c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5471c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5472c3c6c9fcSLai Jiangshan context->sync_spte = ept_sync_spte; 5473347a0d0dSPaolo Bonzini 5474c596f147SSean Christopherson update_permission_bitmask(context, true); 547528f091bcSPaolo Bonzini context->pkru_mask = 0; 5476cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5477e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5478c50d8ae3SPaolo Bonzini } 54793cffc89dSPaolo Bonzini 5480d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 54813cffc89dSPaolo Bonzini } 5482c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5483c50d8ae3SPaolo Bonzini 548439e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5485a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5486c50d8ae3SPaolo Bonzini { 54878c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5488c50d8ae3SPaolo Bonzini 5489a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5490929d1cfaSPaolo Bonzini 54912fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5492c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5493c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5494c50d8ae3SPaolo Bonzini } 5495c50d8ae3SPaolo Bonzini 549639e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5497a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5498c50d8ae3SPaolo Bonzini { 5499c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5500c50d8ae3SPaolo Bonzini 5501e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5502c50d8ae3SPaolo Bonzini return; 5503c50d8ae3SPaolo Bonzini 5504e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 55052fdcc1b3SPaolo Bonzini g_context->get_guest_pgd = get_guest_cr3; 5506c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5507c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5508c50d8ae3SPaolo Bonzini 5509c50d8ae3SPaolo Bonzini /* 55105efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 55115efac074SPaolo Bonzini * SPTEs. 55125efac074SPaolo Bonzini */ 55139fd4a4e3SLai Jiangshan g_context->sync_spte = NULL; 55145efac074SPaolo Bonzini 55155efac074SPaolo Bonzini /* 5516c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5517c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5518c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5519c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5520c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5521c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5522c50d8ae3SPaolo Bonzini */ 5523fa4b5588SSean Christopherson if (!is_paging(vcpu)) 55241f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5525fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 55261f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5527fa4b5588SSean Christopherson else if (is_pae(vcpu)) 55281f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5529fa4b5588SSean Christopherson else 55301f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5531fa4b5588SSean Christopherson 5532533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5533c50d8ae3SPaolo Bonzini } 5534c50d8ae3SPaolo Bonzini 5535c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5536c50d8ae3SPaolo Bonzini { 553739e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5538a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 553939e7e2bfSPaolo Bonzini 5540c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5541a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5542c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5543a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5544c50d8ae3SPaolo Bonzini else 5545a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5546c50d8ae3SPaolo Bonzini } 5547c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5548c50d8ae3SPaolo Bonzini 554949c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 555049c6f875SSean Christopherson { 555149c6f875SSean Christopherson /* 555249c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 555349c6f875SSean Christopherson * information is factored into reserved bit calculations. 5554feb627e8SVitaly Kuznetsov * 5555feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5556feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5557feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5558feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5559338068b5SSean Christopherson * gfn_write_track (see struct kvm_mmu_page_role comments). For now 5560338068b5SSean Christopherson * that problem is swept under the rug; KVM's CPUID API is horrific and 5561feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 556249c6f875SSean Christopherson */ 55637a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 55647a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 55657a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5566e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5567e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5568e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 556949c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 557063f5a190SSean Christopherson 557163f5a190SSean Christopherson /* 5572feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5573feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 557463f5a190SSean Christopherson */ 5575fb3146b4SSean Christopherson KVM_BUG_ON(kvm_vcpu_has_run(vcpu), vcpu->kvm); 557649c6f875SSean Christopherson } 557749c6f875SSean Christopherson 5578c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5579c50d8ae3SPaolo Bonzini { 5580c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5581c9060662SSean Christopherson kvm_init_mmu(vcpu); 5582c50d8ae3SPaolo Bonzini } 5583c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5584c50d8ae3SPaolo Bonzini 5585c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5586c50d8ae3SPaolo Bonzini { 5587c50d8ae3SPaolo Bonzini int r; 5588c50d8ae3SPaolo Bonzini 5589347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5590c50d8ae3SPaolo Bonzini if (r) 5591c50d8ae3SPaolo Bonzini goto out; 5592748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5593c50d8ae3SPaolo Bonzini if (r) 5594c50d8ae3SPaolo Bonzini goto out; 5595347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 55966e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 55976e6ec584SSean Christopherson else 55986e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5599c50d8ae3SPaolo Bonzini if (r) 5600c50d8ae3SPaolo Bonzini goto out; 5601a91f387bSSean Christopherson 5602a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5603a91f387bSSean Christopherson 5604727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5605db01416bSSean Christopherson 5606db01416bSSean Christopherson /* 5607db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5608db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5609db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5610db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5611db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5612db01416bSSean Christopherson */ 5613e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5614c50d8ae3SPaolo Bonzini out: 5615c50d8ae3SPaolo Bonzini return r; 5616c50d8ae3SPaolo Bonzini } 5617c50d8ae3SPaolo Bonzini 5618c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5619c50d8ae3SPaolo Bonzini { 56200c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 56210c1c92f1SPaolo Bonzini 56220c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 562320ba462dSSean Christopherson WARN_ON_ONCE(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 56240c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 562520ba462dSSean Christopherson WARN_ON_ONCE(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 56266d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5627c50d8ae3SPaolo Bonzini } 5628c50d8ae3SPaolo Bonzini 5629527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5630527d5cd7SSean Christopherson { 5631527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5632527d5cd7SSean Christopherson 5633527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5634527d5cd7SSean Christopherson return false; 5635527d5cd7SSean Christopherson 5636527d5cd7SSean Christopherson /* 5637527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 56380e3223d8SSean Christopherson * have an associated shadow page, as it's impossible to determine if 56390e3223d8SSean Christopherson * such roots are fresh or stale. This does mean KVM will get false 5640527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5641527d5cd7SSean Christopherson * such false positives are relatively rare: 5642527d5cd7SSean Christopherson * 56430e3223d8SSean Christopherson * (a) only PAE paging and nested NPT have roots without shadow pages 56440e3223d8SSean Christopherson * (or any shadow paging flavor with a dummy root, see note below) 5645527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5646527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5647527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 56480e3223d8SSean Christopherson * 56490e3223d8SSean Christopherson * Note! Dummy roots are unique in that they are obsoleted by memslot 56500e3223d8SSean Christopherson * _creation_! See also FNAME(fetch). 5651527d5cd7SSean Christopherson */ 5652c5f2d564SSean Christopherson sp = root_to_sp(root_hpa); 5653527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5654527d5cd7SSean Christopherson } 5655527d5cd7SSean Christopherson 5656527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5657527d5cd7SSean Christopherson { 5658527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5659527d5cd7SSean Christopherson int i; 5660527d5cd7SSean Christopherson 5661527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5662527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5663527d5cd7SSean Christopherson 5664527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5665cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5666527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5667527d5cd7SSean Christopherson } 5668527d5cd7SSean Christopherson 5669527d5cd7SSean Christopherson if (roots_to_free) 5670527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5671527d5cd7SSean Christopherson } 5672527d5cd7SSean Christopherson 5673527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5674527d5cd7SSean Christopherson { 5675527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5676527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5677527d5cd7SSean Christopherson } 5678527d5cd7SSean Christopherson 5679c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5680c50d8ae3SPaolo Bonzini int *bytes) 5681c50d8ae3SPaolo Bonzini { 5682c50d8ae3SPaolo Bonzini u64 gentry = 0; 5683c50d8ae3SPaolo Bonzini int r; 5684c50d8ae3SPaolo Bonzini 5685c50d8ae3SPaolo Bonzini /* 5686c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5687c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5688c50d8ae3SPaolo Bonzini * when they have the same mode. 5689c50d8ae3SPaolo Bonzini */ 5690c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5691c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5692c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5693c50d8ae3SPaolo Bonzini *bytes = 8; 5694c50d8ae3SPaolo Bonzini } 5695c50d8ae3SPaolo Bonzini 5696c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5697c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5698c50d8ae3SPaolo Bonzini if (r) 5699c50d8ae3SPaolo Bonzini gentry = 0; 5700c50d8ae3SPaolo Bonzini } 5701c50d8ae3SPaolo Bonzini 5702c50d8ae3SPaolo Bonzini return gentry; 5703c50d8ae3SPaolo Bonzini } 5704c50d8ae3SPaolo Bonzini 5705c50d8ae3SPaolo Bonzini /* 5706c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5707c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5708c50d8ae3SPaolo Bonzini */ 5709c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5710c50d8ae3SPaolo Bonzini { 5711c50d8ae3SPaolo Bonzini /* 5712c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5713c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5714c50d8ae3SPaolo Bonzini */ 57153bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5716c50d8ae3SPaolo Bonzini return false; 5717c50d8ae3SPaolo Bonzini 5718c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5719c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5720c50d8ae3SPaolo Bonzini } 5721c50d8ae3SPaolo Bonzini 5722c50d8ae3SPaolo Bonzini /* 5723c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5724c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5725c50d8ae3SPaolo Bonzini */ 5726c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5727c50d8ae3SPaolo Bonzini int bytes) 5728c50d8ae3SPaolo Bonzini { 5729c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5730c50d8ae3SPaolo Bonzini 5731c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5732bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5733c50d8ae3SPaolo Bonzini 5734c50d8ae3SPaolo Bonzini /* 5735c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5736c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5737c50d8ae3SPaolo Bonzini */ 5738c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5739c50d8ae3SPaolo Bonzini return false; 5740c50d8ae3SPaolo Bonzini 5741c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5742c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5743c50d8ae3SPaolo Bonzini 5744c50d8ae3SPaolo Bonzini return misaligned; 5745c50d8ae3SPaolo Bonzini } 5746c50d8ae3SPaolo Bonzini 5747c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5748c50d8ae3SPaolo Bonzini { 5749c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5750c50d8ae3SPaolo Bonzini u64 *spte; 5751c50d8ae3SPaolo Bonzini int level; 5752c50d8ae3SPaolo Bonzini 5753c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5754c50d8ae3SPaolo Bonzini level = sp->role.level; 5755c50d8ae3SPaolo Bonzini *nspte = 1; 5756bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5757c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5758c50d8ae3SPaolo Bonzini /* 5759c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5760c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5761c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5762c50d8ae3SPaolo Bonzini */ 5763c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5764c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5765c50d8ae3SPaolo Bonzini page_offset <<= 1; 5766c50d8ae3SPaolo Bonzini *nspte = 2; 5767c50d8ae3SPaolo Bonzini } 5768c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5769c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5770c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5771c50d8ae3SPaolo Bonzini return NULL; 5772c50d8ae3SPaolo Bonzini } 5773c50d8ae3SPaolo Bonzini 5774c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5775c50d8ae3SPaolo Bonzini return spte; 5776c50d8ae3SPaolo Bonzini } 5777c50d8ae3SPaolo Bonzini 577893284446SSean Christopherson void kvm_mmu_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, 577993284446SSean Christopherson int bytes) 5780c50d8ae3SPaolo Bonzini { 5781c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5782c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5783c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5784c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5785c50d8ae3SPaolo Bonzini int npte; 578606152b2dSLai Jiangshan bool flush = false; 5787c50d8ae3SPaolo Bonzini 5788c50d8ae3SPaolo Bonzini /* 5789c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5790c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5791c50d8ae3SPaolo Bonzini */ 5792c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5793c50d8ae3SPaolo Bonzini return; 5794c50d8ae3SPaolo Bonzini 5795531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5796c50d8ae3SPaolo Bonzini 5797c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5798c50d8ae3SPaolo Bonzini 5799c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5800c50d8ae3SPaolo Bonzini 5801767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5802c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5803c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5804c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5805c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5806c50d8ae3SPaolo Bonzini continue; 5807c50d8ae3SPaolo Bonzini } 5808c50d8ae3SPaolo Bonzini 5809c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5810c50d8ae3SPaolo Bonzini if (!spte) 5811c50d8ae3SPaolo Bonzini continue; 5812c50d8ae3SPaolo Bonzini 5813c50d8ae3SPaolo Bonzini while (npte--) { 5814c50d8ae3SPaolo Bonzini entry = *spte; 58152de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5816c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5817c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 58181441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 581906152b2dSLai Jiangshan flush = true; 5820c50d8ae3SPaolo Bonzini ++spte; 5821c50d8ae3SPaolo Bonzini } 5822c50d8ae3SPaolo Bonzini } 582306152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5824531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5825c50d8ae3SPaolo Bonzini } 5826c50d8ae3SPaolo Bonzini 58271075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5828c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5829c50d8ae3SPaolo Bonzini { 583092daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5831347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5832c50d8ae3SPaolo Bonzini 583320ba462dSSean Christopherson if (WARN_ON_ONCE(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5834ddce6208SSean Christopherson return RET_PF_RETRY; 5835ddce6208SSean Christopherson 5836b3d5dc62SSean Christopherson /* 5837b3d5dc62SSean Christopherson * Except for reserved faults (emulated MMIO is shared-only), set the 5838b3d5dc62SSean Christopherson * PFERR_PRIVATE_ACCESS flag for software-protected VMs based on the gfn's 5839b3d5dc62SSean Christopherson * current attributes, which are the source of truth for such VMs. Note, 5840b3d5dc62SSean Christopherson * this wrong for nested MMUs as the GPA is an L2 GPA, but KVM doesn't 5841b3d5dc62SSean Christopherson * currently supported nested virtualization (among many other things) 5842b3d5dc62SSean Christopherson * for software-protected VMs. 5843b3d5dc62SSean Christopherson */ 5844b3d5dc62SSean Christopherson if (IS_ENABLED(CONFIG_KVM_SW_PROTECTED_VM) && 5845b3d5dc62SSean Christopherson !(error_code & PFERR_RSVD_MASK) && 5846b3d5dc62SSean Christopherson vcpu->kvm->arch.vm_type == KVM_X86_SW_PROTECTED_VM && 5847b3d5dc62SSean Christopherson kvm_mem_is_private(vcpu->kvm, gpa_to_gfn(cr2_or_gpa))) 5848b3d5dc62SSean Christopherson error_code |= PFERR_PRIVATE_ACCESS; 5849b3d5dc62SSean Christopherson 5850c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5851c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 585207702e5aSSean Christopherson if (WARN_ON_ONCE(error_code & PFERR_PRIVATE_ACCESS)) 585307702e5aSSean Christopherson return -EFAULT; 585407702e5aSSean Christopherson 5855736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5856c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5857c50d8ae3SPaolo Bonzini goto emulate; 5858c50d8ae3SPaolo Bonzini } 5859c50d8ae3SPaolo Bonzini 5860c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 5861c9710130SIsaku Yamahata r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, error_code, false, 5862258d985fSSean Christopherson &emulation_type); 586319025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 58647b367bc9SSean Christopherson return -EIO; 5865c50d8ae3SPaolo Bonzini } 5866c50d8ae3SPaolo Bonzini 5867c50d8ae3SPaolo Bonzini if (r < 0) 5868c50d8ae3SPaolo Bonzini return r; 586983a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 587083a2ba4cSSean Christopherson return 1; 5871c50d8ae3SPaolo Bonzini 5872c50d8ae3SPaolo Bonzini /* 5873c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5874c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5875c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5876c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5877c50d8ae3SPaolo Bonzini * and resume the guest. 5878c50d8ae3SPaolo Bonzini */ 5879347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5880c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5881736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5882c50d8ae3SPaolo Bonzini return 1; 5883c50d8ae3SPaolo Bonzini } 5884c50d8ae3SPaolo Bonzini 5885c50d8ae3SPaolo Bonzini /* 5886c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5887c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5888c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5889c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5890c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5891c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5892c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5893c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5894c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5895c50d8ae3SPaolo Bonzini */ 5896736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 589792daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5898c50d8ae3SPaolo Bonzini emulate: 5899736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5900c50d8ae3SPaolo Bonzini insn_len); 5901c50d8ae3SPaolo Bonzini } 5902c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5903c50d8ae3SPaolo Bonzini 59049fd4a4e3SLai Jiangshan static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 59059fd4a4e3SLai Jiangshan u64 addr, hpa_t root_hpa) 59069fd4a4e3SLai Jiangshan { 59079fd4a4e3SLai Jiangshan struct kvm_shadow_walk_iterator iterator; 59089fd4a4e3SLai Jiangshan 59099fd4a4e3SLai Jiangshan vcpu_clear_mmio_info(vcpu, addr); 59109fd4a4e3SLai Jiangshan 5911762b33ebSLike Xu /* 5912762b33ebSLike Xu * Walking and synchronizing SPTEs both assume they are operating in 5913762b33ebSLike Xu * the context of the current MMU, and would need to be reworked if 5914762b33ebSLike Xu * this is ever used to sync the guest_mmu, e.g. to emulate INVEPT. 5915762b33ebSLike Xu */ 5916762b33ebSLike Xu if (WARN_ON_ONCE(mmu != vcpu->arch.mmu)) 5917762b33ebSLike Xu return; 5918762b33ebSLike Xu 59199fd4a4e3SLai Jiangshan if (!VALID_PAGE(root_hpa)) 59209fd4a4e3SLai Jiangshan return; 59219fd4a4e3SLai Jiangshan 59229fd4a4e3SLai Jiangshan write_lock(&vcpu->kvm->mmu_lock); 59239fd4a4e3SLai Jiangshan for_each_shadow_entry_using_root(vcpu, root_hpa, addr, iterator) { 59249fd4a4e3SLai Jiangshan struct kvm_mmu_page *sp = sptep_to_sp(iterator.sptep); 59259fd4a4e3SLai Jiangshan 59269fd4a4e3SLai Jiangshan if (sp->unsync) { 592719ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, iterator.index); 59289fd4a4e3SLai Jiangshan 59299fd4a4e3SLai Jiangshan if (ret < 0) 59309fd4a4e3SLai Jiangshan mmu_page_zap_pte(vcpu->kvm, sp, iterator.sptep, NULL); 59319fd4a4e3SLai Jiangshan if (ret) 59329fd4a4e3SLai Jiangshan kvm_flush_remote_tlbs_sptep(vcpu->kvm, iterator.sptep); 59339fd4a4e3SLai Jiangshan } 59349fd4a4e3SLai Jiangshan 59359fd4a4e3SLai Jiangshan if (!sp->unsync_children) 59369fd4a4e3SLai Jiangshan break; 59379fd4a4e3SLai Jiangshan } 59389fd4a4e3SLai Jiangshan write_unlock(&vcpu->kvm->mmu_lock); 59399fd4a4e3SLai Jiangshan } 59409fd4a4e3SLai Jiangshan 5941753b43c9SLai Jiangshan void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 5942cd42853eSLai Jiangshan u64 addr, unsigned long roots) 5943c50d8ae3SPaolo Bonzini { 5944c50d8ae3SPaolo Bonzini int i; 5945c50d8ae3SPaolo Bonzini 5946cd42853eSLai Jiangshan WARN_ON_ONCE(roots & ~KVM_MMU_ROOTS_ALL); 5947cd42853eSLai Jiangshan 59485efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 59495efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 59505efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5951753b43c9SLai Jiangshan if (is_noncanonical_address(addr, vcpu)) 5952c50d8ae3SPaolo Bonzini return; 5953c50d8ae3SPaolo Bonzini 5954753b43c9SLai Jiangshan static_call(kvm_x86_flush_tlb_gva)(vcpu, addr); 59555efac074SPaolo Bonzini } 59565efac074SPaolo Bonzini 59579fd4a4e3SLai Jiangshan if (!mmu->sync_spte) 59585efac074SPaolo Bonzini return; 59595efac074SPaolo Bonzini 5960cd42853eSLai Jiangshan if (roots & KVM_MMU_ROOT_CURRENT) 59619fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->root.hpa); 5962c50d8ae3SPaolo Bonzini 5963cd42853eSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5964ed335278SLai Jiangshan if (roots & KVM_MMU_ROOT_PREVIOUS(i)) 59659fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->prev_roots[i].hpa); 59665efac074SPaolo Bonzini } 59675efac074SPaolo Bonzini } 59682c86c444SLai Jiangshan EXPORT_SYMBOL_GPL(kvm_mmu_invalidate_addr); 5969c50d8ae3SPaolo Bonzini 59705efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 59715efac074SPaolo Bonzini { 5972cd42853eSLai Jiangshan /* 5973cd42853eSLai Jiangshan * INVLPG is required to invalidate any global mappings for the VA, 5974cd42853eSLai Jiangshan * irrespective of PCID. Blindly sync all roots as it would take 5975cd42853eSLai Jiangshan * roughly the same amount of work/time to determine whether any of the 5976cd42853eSLai Jiangshan * previous roots have a global mapping. 5977cd42853eSLai Jiangshan * 5978cd42853eSLai Jiangshan * Mappings not reachable via the current or previous cached roots will 5979cd42853eSLai Jiangshan * be synced when switching to that new cr3, so nothing needs to be 5980cd42853eSLai Jiangshan * done here for them. 5981cd42853eSLai Jiangshan */ 5982cd42853eSLai Jiangshan kvm_mmu_invalidate_addr(vcpu, vcpu->arch.walk_mmu, gva, KVM_MMU_ROOTS_ALL); 5983c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5984c50d8ae3SPaolo Bonzini } 5985c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5986c50d8ae3SPaolo Bonzini 59875efac074SPaolo Bonzini 5988c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5989c50d8ae3SPaolo Bonzini { 5990c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 59919ebc3f51SLai Jiangshan unsigned long roots = 0; 5992c50d8ae3SPaolo Bonzini uint i; 5993c50d8ae3SPaolo Bonzini 59949ebc3f51SLai Jiangshan if (pcid == kvm_get_active_pcid(vcpu)) 59959ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_CURRENT; 5996c50d8ae3SPaolo Bonzini 5997c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5998c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 59999ebc3f51SLai Jiangshan pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) 60009ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_PREVIOUS(i); 6001c50d8ae3SPaolo Bonzini } 6002c50d8ae3SPaolo Bonzini 60039ebc3f51SLai Jiangshan if (roots) 60049ebc3f51SLai Jiangshan kvm_mmu_invalidate_addr(vcpu, mmu, gva, roots); 6005c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 6006c50d8ae3SPaolo Bonzini 6007c50d8ae3SPaolo Bonzini /* 6008c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 6009c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 6010c50d8ae3SPaolo Bonzini * for them. 6011c50d8ae3SPaolo Bonzini */ 6012c50d8ae3SPaolo Bonzini } 6013c50d8ae3SPaolo Bonzini 6014746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 6015746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 6016c50d8ae3SPaolo Bonzini { 6017bde77235SSean Christopherson tdp_enabled = enable_tdp; 6018746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 601983013059SSean Christopherson max_tdp_level = tdp_max_root_level; 6020703c335dSSean Christopherson 60211f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 60221f98f2bdSDavid Matlack tdp_mmu_enabled = tdp_mmu_allowed && tdp_enabled; 60231f98f2bdSDavid Matlack #endif 6024703c335dSSean Christopherson /* 60251d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 6026703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 6027703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 6028703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 6029703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 6030703c335dSSean Christopherson */ 6031703c335dSSean Christopherson if (tdp_enabled) 60321d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 6033703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 60341d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 6035703c335dSSean Christopherson else 60361d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 6037c50d8ae3SPaolo Bonzini } 6038bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 6039c50d8ae3SPaolo Bonzini 6040c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 6041727ae377SSean Christopherson typedef bool (*slot_rmaps_handler) (struct kvm *kvm, 6042269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 6043269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 6044c50d8ae3SPaolo Bonzini 6045727ae377SSean Christopherson static __always_inline bool __walk_slot_rmaps(struct kvm *kvm, 6046727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6047727ae377SSean Christopherson slot_rmaps_handler fn, 6048727ae377SSean Christopherson int start_level, int end_level, 6049727ae377SSean Christopherson gfn_t start_gfn, gfn_t end_gfn, 6050727ae377SSean Christopherson bool flush_on_yield, bool flush) 6051c50d8ae3SPaolo Bonzini { 6052c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 6053c50d8ae3SPaolo Bonzini 6054eddd9e83SSean Christopherson lockdep_assert_held_write(&kvm->mmu_lock); 6055eddd9e83SSean Christopherson 6056727ae377SSean Christopherson for_each_slot_rmap_range(slot, start_level, end_level, start_gfn, 6057c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 6058c50d8ae3SPaolo Bonzini if (iterator.rmap) 6059727ae377SSean Christopherson flush |= fn(kvm, iterator.rmap, slot); 6060c50d8ae3SPaolo Bonzini 6061531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6062302695a5SSean Christopherson if (flush && flush_on_yield) { 60638c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, start_gfn, 6064c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 6065c50d8ae3SPaolo Bonzini flush = false; 6066c50d8ae3SPaolo Bonzini } 6067531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6068c50d8ae3SPaolo Bonzini } 6069c50d8ae3SPaolo Bonzini } 6070c50d8ae3SPaolo Bonzini 6071c50d8ae3SPaolo Bonzini return flush; 6072c50d8ae3SPaolo Bonzini } 6073c50d8ae3SPaolo Bonzini 6074727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps(struct kvm *kvm, 6075727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6076727ae377SSean Christopherson slot_rmaps_handler fn, 6077727ae377SSean Christopherson int start_level, int end_level, 6078302695a5SSean Christopherson bool flush_on_yield) 6079c50d8ae3SPaolo Bonzini { 6080727ae377SSean Christopherson return __walk_slot_rmaps(kvm, slot, fn, start_level, end_level, 6081727ae377SSean Christopherson slot->base_gfn, slot->base_gfn + slot->npages - 1, 60821a61b7dbSSean Christopherson flush_on_yield, false); 6083c50d8ae3SPaolo Bonzini } 6084c50d8ae3SPaolo Bonzini 6085727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps_4k(struct kvm *kvm, 6086727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6087727ae377SSean Christopherson slot_rmaps_handler fn, 6088727ae377SSean Christopherson bool flush_on_yield) 6089c50d8ae3SPaolo Bonzini { 6090727ae377SSean Christopherson return walk_slot_rmaps(kvm, slot, fn, PG_LEVEL_4K, PG_LEVEL_4K, flush_on_yield); 6091c50d8ae3SPaolo Bonzini } 6092c50d8ae3SPaolo Bonzini 6093c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 6094c50d8ae3SPaolo Bonzini { 60954a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 60964a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 6097c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 609803ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 6099cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 6100c50d8ae3SPaolo Bonzini } 6101c50d8ae3SPaolo Bonzini 610204d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 6103c50d8ae3SPaolo Bonzini { 6104c50d8ae3SPaolo Bonzini struct page *page; 6105c50d8ae3SPaolo Bonzini int i; 6106c50d8ae3SPaolo Bonzini 6107b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 6108b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 610904d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 611004d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 611104d28e37SSean Christopherson 611227f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 611327f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 611427f4fca2SLai Jiangshan return 0; 611527f4fca2SLai Jiangshan 6116c50d8ae3SPaolo Bonzini /* 6117c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 6118c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 6119c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 6120c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 612104d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 612204d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 612304d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 612404d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 612584432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 6126c50d8ae3SPaolo Bonzini */ 6127d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 6128c50d8ae3SPaolo Bonzini return 0; 6129c50d8ae3SPaolo Bonzini 6130c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 6131c50d8ae3SPaolo Bonzini if (!page) 6132c50d8ae3SPaolo Bonzini return -ENOMEM; 6133c50d8ae3SPaolo Bonzini 6134c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 61354a98623dSSean Christopherson 61364a98623dSSean Christopherson /* 61374a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 61384a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 61394a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 61404a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 61414a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 61424a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 61434a98623dSSean Christopherson */ 61444a98623dSSean Christopherson if (!tdp_enabled) 61454a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 61464a98623dSSean Christopherson else 6147e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 61484a98623dSSean Christopherson 6149c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 6150c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 6151c50d8ae3SPaolo Bonzini 6152c50d8ae3SPaolo Bonzini return 0; 6153c50d8ae3SPaolo Bonzini } 6154c50d8ae3SPaolo Bonzini 6155c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 6156c50d8ae3SPaolo Bonzini { 6157c50d8ae3SPaolo Bonzini int ret; 6158c50d8ae3SPaolo Bonzini 61595962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 61605f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 61615f6078f9SSean Christopherson 61625962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 61635f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 61645962bfb7SSean Christopherson 616596880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 616696880883SSean Christopherson 6167c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 6168c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 6169c50d8ae3SPaolo Bonzini 617004d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 6171c50d8ae3SPaolo Bonzini if (ret) 6172c50d8ae3SPaolo Bonzini return ret; 6173c50d8ae3SPaolo Bonzini 617404d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 6175c50d8ae3SPaolo Bonzini if (ret) 6176c50d8ae3SPaolo Bonzini goto fail_allocate_root; 6177c50d8ae3SPaolo Bonzini 6178c50d8ae3SPaolo Bonzini return ret; 6179c50d8ae3SPaolo Bonzini fail_allocate_root: 6180c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6181c50d8ae3SPaolo Bonzini return ret; 6182c50d8ae3SPaolo Bonzini } 6183c50d8ae3SPaolo Bonzini 6184c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 6185c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 6186c50d8ae3SPaolo Bonzini { 6187c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6188c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 6189b28cb0cdSSean Christopherson bool unstable; 6190c50d8ae3SPaolo Bonzini 6191c50d8ae3SPaolo Bonzini restart: 6192c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 6193c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 6194c50d8ae3SPaolo Bonzini /* 6195c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 6196c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 6197c50d8ae3SPaolo Bonzini */ 6198c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 6199c50d8ae3SPaolo Bonzini break; 6200c50d8ae3SPaolo Bonzini 6201c50d8ae3SPaolo Bonzini /* 6202f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 6203f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 6204f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 6205c50d8ae3SPaolo Bonzini */ 620620ba462dSSean Christopherson if (WARN_ON_ONCE(sp->role.invalid)) 6207c50d8ae3SPaolo Bonzini continue; 6208c50d8ae3SPaolo Bonzini 6209c50d8ae3SPaolo Bonzini /* 6210c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 6211c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 6212c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 6213c50d8ae3SPaolo Bonzini * be in active use by the guest. 6214c50d8ae3SPaolo Bonzini */ 6215c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 6216531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 6217c50d8ae3SPaolo Bonzini batch = 0; 6218c50d8ae3SPaolo Bonzini goto restart; 6219c50d8ae3SPaolo Bonzini } 6220c50d8ae3SPaolo Bonzini 6221b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 6222b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 6223c50d8ae3SPaolo Bonzini batch += nr_zapped; 6224b28cb0cdSSean Christopherson 6225b28cb0cdSSean Christopherson if (unstable) 6226c50d8ae3SPaolo Bonzini goto restart; 6227c50d8ae3SPaolo Bonzini } 6228c50d8ae3SPaolo Bonzini 6229c50d8ae3SPaolo Bonzini /* 62307ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 62317ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 62327ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 62337ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 62347ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 62357ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 62367ae5840eSSean Christopherson * running with an obsolete MMU. 6237c50d8ae3SPaolo Bonzini */ 6238c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 6239c50d8ae3SPaolo Bonzini } 6240c50d8ae3SPaolo Bonzini 6241c50d8ae3SPaolo Bonzini /* 6242c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 6243c50d8ae3SPaolo Bonzini * to zap obsolete pages. 6244c50d8ae3SPaolo Bonzini * 6245c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 6246c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 6247c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 6248c50d8ae3SPaolo Bonzini * after calling the function. 6249c50d8ae3SPaolo Bonzini */ 6250c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 6251c50d8ae3SPaolo Bonzini { 6252c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 6253c50d8ae3SPaolo Bonzini 6254531810caSBen Gardon write_lock(&kvm->mmu_lock); 6255c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 6256c50d8ae3SPaolo Bonzini 6257c50d8ae3SPaolo Bonzini /* 6258c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 6259c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 6260c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 6261c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 6262c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 6263c50d8ae3SPaolo Bonzini */ 6264c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 6265c50d8ae3SPaolo Bonzini 62662f6f66ccSSean Christopherson /* 62672f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 62682f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 62692f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 62702f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 6271b7cccd39SBen Gardon */ 62721f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6273b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 6274b7cccd39SBen Gardon 6275c50d8ae3SPaolo Bonzini /* 6276c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 6277c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 6278c50d8ae3SPaolo Bonzini * mmu_valid_gen. 6279c50d8ae3SPaolo Bonzini * 6280c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 6281c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 6282c50d8ae3SPaolo Bonzini */ 6283527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 6284c50d8ae3SPaolo Bonzini 6285c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 6286faaf05b0SBen Gardon 6287531810caSBen Gardon write_unlock(&kvm->mmu_lock); 62884c6654bdSBen Gardon 6289f28e9c7fSSean Christopherson /* 6290f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 6291f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 6292f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 6293f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 6294f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 6295f28e9c7fSSean Christopherson * lead to use-after-free. 6296f28e9c7fSSean Christopherson */ 62971f98f2bdSDavid Matlack if (tdp_mmu_enabled) 62984c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 6299c50d8ae3SPaolo Bonzini } 6300c50d8ae3SPaolo Bonzini 6301c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 6302c50d8ae3SPaolo Bonzini { 6303c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 6304c50d8ae3SPaolo Bonzini } 6305c50d8ae3SPaolo Bonzini 63060df9dab8SSean Christopherson void kvm_mmu_init_vm(struct kvm *kvm) 6307c50d8ae3SPaolo Bonzini { 6308a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 6309a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 631055c510e2SSean Christopherson INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages); 6311ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 6312ce25681dSSean Christopherson 63130df9dab8SSean Christopherson if (tdp_mmu_enabled) 63140df9dab8SSean Christopherson kvm_mmu_init_tdp_mmu(kvm); 6315fe5db27dSBen Gardon 6316ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 6317ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 6318ada51a9dSDavid Matlack 6319ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 6320ada51a9dSDavid Matlack 6321ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 6322ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 6323c50d8ae3SPaolo Bonzini } 6324c50d8ae3SPaolo Bonzini 6325ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 6326ada51a9dSDavid Matlack { 6327ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 6328ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6329ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6330ada51a9dSDavid Matlack } 6331ada51a9dSDavid Matlack 6332c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6333c50d8ae3SPaolo Bonzini { 633409732d2bSDavid Matlack if (tdp_mmu_enabled) 6335fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6336ada51a9dSDavid Matlack 6337ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6338c50d8ae3SPaolo Bonzini } 6339c50d8ae3SPaolo Bonzini 63402833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 634121fa3246SSean Christopherson { 634221fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 634321fa3246SSean Christopherson struct kvm_memslots *slots; 6344f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 634521fa3246SSean Christopherson bool flush = false; 634621fa3246SSean Christopherson gfn_t start, end; 6347f4209439SMaciej S. Szmigiero int i; 634821fa3246SSean Christopherson 634921fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 635021fa3246SSean Christopherson return flush; 635121fa3246SSean Christopherson 6352eed52e43SSean Christopherson for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { 635321fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6354f4209439SMaciej S. Szmigiero 6355f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6356f4209439SMaciej S. Szmigiero memslot = iter.slot; 635721fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 635821fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6359f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 636021fa3246SSean Christopherson continue; 636121fa3246SSean Christopherson 6362727ae377SSean Christopherson flush = __walk_slot_rmaps(kvm, memslot, __kvm_zap_rmap, 636321fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 636421fa3246SSean Christopherson start, end - 1, true, flush); 636521fa3246SSean Christopherson } 636621fa3246SSean Christopherson } 636721fa3246SSean Christopherson 636821fa3246SSean Christopherson return flush; 636921fa3246SSean Christopherson } 637021fa3246SSean Christopherson 637188f58535SMaxim Levitsky /* 637288f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 637388f58535SMaxim Levitsky * (not including it) 637488f58535SMaxim Levitsky */ 6375c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6376c50d8ae3SPaolo Bonzini { 637721fa3246SSean Christopherson bool flush; 6378c50d8ae3SPaolo Bonzini 6379f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6380f4209439SMaciej S. Szmigiero return; 6381f4209439SMaciej S. Szmigiero 6382531810caSBen Gardon write_lock(&kvm->mmu_lock); 63835a324c24SSean Christopherson 63848569992dSChao Peng kvm_mmu_invalidate_begin(kvm); 63858569992dSChao Peng 63868569992dSChao Peng kvm_mmu_invalidate_range_add(kvm, gfn_start, gfn_end); 6387edb298c6SMaxim Levitsky 63882833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 63896103bc07SBen Gardon 6390441a5dfcSPaolo Bonzini if (tdp_mmu_enabled) 6391441a5dfcSPaolo Bonzini flush = kvm_tdp_mmu_zap_leafs(kvm, gfn_start, gfn_end, flush); 63925a324c24SSean Christopherson 63935a324c24SSean Christopherson if (flush) 63948c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, gfn_start, gfn_end - gfn_start); 63955a324c24SSean Christopherson 63968569992dSChao Peng kvm_mmu_invalidate_end(kvm); 6397edb298c6SMaxim Levitsky 63985a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6399c50d8ae3SPaolo Bonzini } 6400c50d8ae3SPaolo Bonzini 6401c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 64020a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6403269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6404c50d8ae3SPaolo Bonzini { 64051346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6406c50d8ae3SPaolo Bonzini } 6407c50d8ae3SPaolo Bonzini 6408c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6409269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 64103c9bd400SJay Zhou int start_level) 6411c50d8ae3SPaolo Bonzini { 6412e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6413531810caSBen Gardon write_lock(&kvm->mmu_lock); 6414727ae377SSean Christopherson walk_slot_rmaps(kvm, memslot, slot_rmap_write_protect, 6415b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6416531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6417e2209710SBen Gardon } 6418c50d8ae3SPaolo Bonzini 64191f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 642024ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6421b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 642224ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 642324ae4cfaSBen Gardon } 6424c50d8ae3SPaolo Bonzini } 6425c50d8ae3SPaolo Bonzini 6426ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6427ada51a9dSDavid Matlack { 6428ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6429ada51a9dSDavid Matlack } 6430ada51a9dSDavid Matlack 6431ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6432ada51a9dSDavid Matlack { 6433ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6434ada51a9dSDavid Matlack return true; 6435ada51a9dSDavid Matlack 6436ada51a9dSDavid Matlack /* 6437ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6438ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6439ada51a9dSDavid Matlack * is possible but not worth the complexity. 6440ada51a9dSDavid Matlack */ 6441ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6442ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6443ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6444ada51a9dSDavid Matlack } 6445ada51a9dSDavid Matlack 6446ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6447ada51a9dSDavid Matlack { 6448b9b71f43SSean Christopherson /* 6449b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6450dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6451b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6452dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6453dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6454dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6455dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6456dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6457dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6458dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6459b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6460b9b71f43SSean Christopherson */ 6461b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6462b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6463ada51a9dSDavid Matlack int r; 6464ada51a9dSDavid Matlack 6465ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6466ada51a9dSDavid Matlack 6467b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6468ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6469ada51a9dSDavid Matlack if (r) 6470ada51a9dSDavid Matlack return r; 6471ada51a9dSDavid Matlack 6472ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6473ada51a9dSDavid Matlack if (r) 6474ada51a9dSDavid Matlack return r; 6475ada51a9dSDavid Matlack 6476ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6477ada51a9dSDavid Matlack } 6478ada51a9dSDavid Matlack 6479ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6480ada51a9dSDavid Matlack { 6481ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6482ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6483ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6484ada51a9dSDavid Matlack unsigned int access; 6485ada51a9dSDavid Matlack gfn_t gfn; 6486ada51a9dSDavid Matlack 648779e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 648879e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6489ada51a9dSDavid Matlack 6490ada51a9dSDavid Matlack /* 6491ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6492ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6493ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6494ada51a9dSDavid Matlack * mapped with smaller pages. 6495ada51a9dSDavid Matlack */ 6496ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6497ada51a9dSDavid Matlack 6498ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6499ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6500ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6501ada51a9dSDavid Matlack 6502ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6503ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6504ada51a9dSDavid Matlack } 6505ada51a9dSDavid Matlack 6506ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6507ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6508ada51a9dSDavid Matlack u64 *huge_sptep) 6509ada51a9dSDavid Matlack 6510ada51a9dSDavid Matlack { 6511ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6512ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6513ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 651403787394SPaolo Bonzini bool flush = false; 6515ada51a9dSDavid Matlack u64 *sptep, spte; 6516ada51a9dSDavid Matlack gfn_t gfn; 6517ada51a9dSDavid Matlack int index; 6518ada51a9dSDavid Matlack 6519ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6520ada51a9dSDavid Matlack 6521ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6522ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6523ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6524ada51a9dSDavid Matlack 6525ada51a9dSDavid Matlack /* 6526ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6527ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6528ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6529ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6530ada51a9dSDavid Matlack * modify them. 6531ada51a9dSDavid Matlack * 653203787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 653303787394SPaolo Bonzini * that lower level page table may only be partially populated. 653403787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 653503787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 653603787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 653703787394SPaolo Bonzini * fail to detect the need to flush. 6538ada51a9dSDavid Matlack */ 653903787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 654003787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6541ada51a9dSDavid Matlack continue; 654203787394SPaolo Bonzini } 6543ada51a9dSDavid Matlack 6544ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6545ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6546ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6547ada51a9dSDavid Matlack } 6548ada51a9dSDavid Matlack 654903787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6550ada51a9dSDavid Matlack } 6551ada51a9dSDavid Matlack 6552ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6553ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6554ada51a9dSDavid Matlack u64 *huge_sptep) 6555ada51a9dSDavid Matlack { 6556ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6557ada51a9dSDavid Matlack int level, r = 0; 6558ada51a9dSDavid Matlack gfn_t gfn; 6559ada51a9dSDavid Matlack u64 spte; 6560ada51a9dSDavid Matlack 6561ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 656279e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6563ada51a9dSDavid Matlack level = huge_sp->role.level; 6564ada51a9dSDavid Matlack spte = *huge_sptep; 6565ada51a9dSDavid Matlack 6566ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6567ada51a9dSDavid Matlack r = -ENOSPC; 6568ada51a9dSDavid Matlack goto out; 6569ada51a9dSDavid Matlack } 6570ada51a9dSDavid Matlack 6571ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6572ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6573ada51a9dSDavid Matlack cond_resched(); 6574ada51a9dSDavid Matlack /* 6575ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6576ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6577ada51a9dSDavid Matlack * dropped. 6578ada51a9dSDavid Matlack */ 6579ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6580ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6581ada51a9dSDavid Matlack goto out; 6582ada51a9dSDavid Matlack } 6583ada51a9dSDavid Matlack 6584ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6585ada51a9dSDavid Matlack 6586ada51a9dSDavid Matlack out: 6587ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6588ada51a9dSDavid Matlack return r; 6589ada51a9dSDavid Matlack } 6590ada51a9dSDavid Matlack 6591ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6592ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6593ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6594ada51a9dSDavid Matlack { 6595ada51a9dSDavid Matlack struct rmap_iterator iter; 6596ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6597ada51a9dSDavid Matlack u64 *huge_sptep; 6598ada51a9dSDavid Matlack int r; 6599ada51a9dSDavid Matlack 6600ada51a9dSDavid Matlack restart: 6601ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6602ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6603ada51a9dSDavid Matlack 6604ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6605ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6606ada51a9dSDavid Matlack continue; 6607ada51a9dSDavid Matlack 6608ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6609ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6610ada51a9dSDavid Matlack continue; 6611ada51a9dSDavid Matlack 6612ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6613ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6614ada51a9dSDavid Matlack continue; 6615ada51a9dSDavid Matlack 6616ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6617ada51a9dSDavid Matlack if (sp->role.invalid) 6618ada51a9dSDavid Matlack continue; 6619ada51a9dSDavid Matlack 6620ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6621ada51a9dSDavid Matlack 6622ada51a9dSDavid Matlack /* 6623ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6624ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6625ada51a9dSDavid Matlack * back into a consistent state. 6626ada51a9dSDavid Matlack */ 6627ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6628ada51a9dSDavid Matlack goto restart; 6629ada51a9dSDavid Matlack 6630ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6631ada51a9dSDavid Matlack break; 6632ada51a9dSDavid Matlack } 6633ada51a9dSDavid Matlack 6634ada51a9dSDavid Matlack return false; 6635ada51a9dSDavid Matlack } 6636ada51a9dSDavid Matlack 6637ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6638ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6639ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6640ada51a9dSDavid Matlack int target_level) 6641ada51a9dSDavid Matlack { 6642ada51a9dSDavid Matlack int level; 6643ada51a9dSDavid Matlack 6644ada51a9dSDavid Matlack /* 6645ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6646ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6647ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6648ada51a9dSDavid Matlack * already at the target level. 6649ada51a9dSDavid Matlack */ 6650727ae377SSean Christopherson for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) 6651727ae377SSean Christopherson __walk_slot_rmaps(kvm, slot, shadow_mmu_try_split_huge_pages, 6652ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6653ada51a9dSDavid Matlack } 6654ada51a9dSDavid Matlack 6655cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6656cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6657cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6658cb00a70bSDavid Matlack u64 start, u64 end, 6659cb00a70bSDavid Matlack int target_level) 6660cb00a70bSDavid Matlack { 66611f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6662ada51a9dSDavid Matlack return; 6663ada51a9dSDavid Matlack 6664ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6665ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6666ada51a9dSDavid Matlack 6667ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6668cb00a70bSDavid Matlack 6669cb00a70bSDavid Matlack /* 667054aa699eSBjorn Helgaas * A TLB flush is unnecessary at this point for the same reasons as in 6671cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6672cb00a70bSDavid Matlack */ 6673cb00a70bSDavid Matlack } 6674cb00a70bSDavid Matlack 6675a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6676a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6677a3fe5dbdSDavid Matlack int target_level) 6678a3fe5dbdSDavid Matlack { 6679a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6680a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6681a3fe5dbdSDavid Matlack 66821f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6683ada51a9dSDavid Matlack return; 6684ada51a9dSDavid Matlack 6685ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6686ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6687ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6688ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6689ada51a9dSDavid Matlack } 6690ada51a9dSDavid Matlack 6691a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6692cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6693a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6694a3fe5dbdSDavid Matlack 6695a3fe5dbdSDavid Matlack /* 6696a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6697a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6698a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6699a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6700a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6701a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6702a3fe5dbdSDavid Matlack * SPTEs. 6703a3fe5dbdSDavid Matlack */ 6704a3fe5dbdSDavid Matlack } 6705a3fe5dbdSDavid Matlack 6706c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 67070a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6708269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6709c50d8ae3SPaolo Bonzini { 6710c50d8ae3SPaolo Bonzini u64 *sptep; 6711c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6712c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6713c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6714c50d8ae3SPaolo Bonzini 6715c50d8ae3SPaolo Bonzini restart: 6716c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 671757354682SSean Christopherson sp = sptep_to_sp(sptep); 6718c50d8ae3SPaolo Bonzini 6719c50d8ae3SPaolo Bonzini /* 6720c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6721c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6722c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6723c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6724c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6725c50d8ae3SPaolo Bonzini */ 67265d49f08cSSean Christopherson if (sp->role.direct && 67279eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6728a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 67299202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6730c50d8ae3SPaolo Bonzini 67318a1300ffSSean Christopherson if (kvm_available_flush_remote_tlbs_range()) 67321b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 6733c50d8ae3SPaolo Bonzini else 6734c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6735c50d8ae3SPaolo Bonzini 6736c50d8ae3SPaolo Bonzini goto restart; 6737c50d8ae3SPaolo Bonzini } 6738c50d8ae3SPaolo Bonzini } 6739c50d8ae3SPaolo Bonzini 6740c50d8ae3SPaolo Bonzini return need_tlb_flush; 6741c50d8ae3SPaolo Bonzini } 6742c50d8ae3SPaolo Bonzini 674320d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 674420d49186SDavid Matlack const struct kvm_memory_slot *slot) 674520d49186SDavid Matlack { 674620d49186SDavid Matlack /* 674720d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 674820d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 674920d49186SDavid Matlack */ 6750727ae377SSean Christopherson if (walk_slot_rmaps(kvm, slot, kvm_mmu_zap_collapsible_spte, 675120d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 6752619b5072SDavid Matlack kvm_flush_remote_tlbs_memslot(kvm, slot); 675320d49186SDavid Matlack } 675420d49186SDavid Matlack 6755c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6756269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6757c50d8ae3SPaolo Bonzini { 6758e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6759531810caSBen Gardon write_lock(&kvm->mmu_lock); 676020d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6761531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6762e2209710SBen Gardon } 67632db6f772SBen Gardon 67641f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 67652db6f772SBen Gardon read_lock(&kvm->mmu_lock); 67664b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 67672db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 67682db6f772SBen Gardon } 6769c50d8ae3SPaolo Bonzini } 6770c50d8ae3SPaolo Bonzini 6771c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6772269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6773c50d8ae3SPaolo Bonzini { 6774e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6775531810caSBen Gardon write_lock(&kvm->mmu_lock); 6776610265eaSDavid Matlack /* 6777610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6778610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6779610265eaSDavid Matlack */ 6780727ae377SSean Christopherson walk_slot_rmaps_4k(kvm, memslot, __rmap_clear_dirty, false); 6781531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6782e2209710SBen Gardon } 6783c50d8ae3SPaolo Bonzini 67841f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 678524ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6786b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 678724ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 678824ae4cfaSBen Gardon } 678924ae4cfaSBen Gardon 6790c50d8ae3SPaolo Bonzini /* 6791b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6792b64d740eSJunaid Shahid * 6793c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6794c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6795c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6796c50d8ae3SPaolo Bonzini * dirty_bitmap. 6797c50d8ae3SPaolo Bonzini */ 6798c50d8ae3SPaolo Bonzini } 6799c50d8ae3SPaolo Bonzini 6800db0d70e6SSean Christopherson static void kvm_mmu_zap_all(struct kvm *kvm) 6801c50d8ae3SPaolo Bonzini { 6802c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6803c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6804c50d8ae3SPaolo Bonzini int ign; 6805c50d8ae3SPaolo Bonzini 6806531810caSBen Gardon write_lock(&kvm->mmu_lock); 6807c50d8ae3SPaolo Bonzini restart: 6808c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 680920ba462dSSean Christopherson if (WARN_ON_ONCE(sp->role.invalid)) 6810c50d8ae3SPaolo Bonzini continue; 6811c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6812c50d8ae3SPaolo Bonzini goto restart; 6813531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6814c50d8ae3SPaolo Bonzini goto restart; 6815c50d8ae3SPaolo Bonzini } 6816c50d8ae3SPaolo Bonzini 6817c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6818faaf05b0SBen Gardon 68191f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6820faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6821faaf05b0SBen Gardon 6822531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6823c50d8ae3SPaolo Bonzini } 6824c50d8ae3SPaolo Bonzini 6825db0d70e6SSean Christopherson void kvm_arch_flush_shadow_all(struct kvm *kvm) 6826db0d70e6SSean Christopherson { 6827db0d70e6SSean Christopherson kvm_mmu_zap_all(kvm); 6828db0d70e6SSean Christopherson } 6829db0d70e6SSean Christopherson 6830db0d70e6SSean Christopherson void kvm_arch_flush_shadow_memslot(struct kvm *kvm, 6831db0d70e6SSean Christopherson struct kvm_memory_slot *slot) 6832db0d70e6SSean Christopherson { 6833eeb87272SSean Christopherson kvm_mmu_zap_all_fast(kvm); 6834db0d70e6SSean Christopherson } 6835db0d70e6SSean Christopherson 6836c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6837c50d8ae3SPaolo Bonzini { 683820ba462dSSean Christopherson WARN_ON_ONCE(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6839c50d8ae3SPaolo Bonzini 6840c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6841c50d8ae3SPaolo Bonzini 6842c50d8ae3SPaolo Bonzini /* 6843c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6844c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6845c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6846c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6847c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6848c50d8ae3SPaolo Bonzini */ 6849eed52e43SSean Christopherson gen &= ~((u64)kvm_arch_nr_memslot_as_ids(kvm) - 1); 6850c50d8ae3SPaolo Bonzini 6851c50d8ae3SPaolo Bonzini /* 6852c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6853c50d8ae3SPaolo Bonzini * zap all shadow pages. 6854c50d8ae3SPaolo Bonzini */ 6855c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 68568d20bd63SSean Christopherson kvm_debug_ratelimited("zapping shadow pages for mmio generation wraparound\n"); 6857c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6858c50d8ae3SPaolo Bonzini } 6859c50d8ae3SPaolo Bonzini } 6860c50d8ae3SPaolo Bonzini 6861f3d90f90SSean Christopherson static unsigned long mmu_shrink_scan(struct shrinker *shrink, 6862f3d90f90SSean Christopherson struct shrink_control *sc) 6863c50d8ae3SPaolo Bonzini { 6864c50d8ae3SPaolo Bonzini struct kvm *kvm; 6865c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6866c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6867c50d8ae3SPaolo Bonzini 6868c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6869c50d8ae3SPaolo Bonzini 6870c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6871c50d8ae3SPaolo Bonzini int idx; 6872c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6873c50d8ae3SPaolo Bonzini 6874c50d8ae3SPaolo Bonzini /* 6875c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6876c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6877c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6878c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6879c50d8ae3SPaolo Bonzini */ 6880c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6881c50d8ae3SPaolo Bonzini break; 6882c50d8ae3SPaolo Bonzini /* 6883c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6884c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6885c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6886c50d8ae3SPaolo Bonzini * anyway. 6887c50d8ae3SPaolo Bonzini */ 6888c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6889c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6890c50d8ae3SPaolo Bonzini continue; 6891c50d8ae3SPaolo Bonzini 6892c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6893531810caSBen Gardon write_lock(&kvm->mmu_lock); 6894c50d8ae3SPaolo Bonzini 6895c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6896c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6897c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6898c50d8ae3SPaolo Bonzini goto unlock; 6899c50d8ae3SPaolo Bonzini } 6900c50d8ae3SPaolo Bonzini 6901ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6902c50d8ae3SPaolo Bonzini 6903c50d8ae3SPaolo Bonzini unlock: 6904531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6905c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6906c50d8ae3SPaolo Bonzini 6907c50d8ae3SPaolo Bonzini /* 6908c50d8ae3SPaolo Bonzini * unfair on small ones 6909c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6910c50d8ae3SPaolo Bonzini * sadness comes quickly 6911c50d8ae3SPaolo Bonzini */ 6912c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6913c50d8ae3SPaolo Bonzini break; 6914c50d8ae3SPaolo Bonzini } 6915c50d8ae3SPaolo Bonzini 6916c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6917c50d8ae3SPaolo Bonzini return freed; 6918c50d8ae3SPaolo Bonzini } 6919c50d8ae3SPaolo Bonzini 6920f3d90f90SSean Christopherson static unsigned long mmu_shrink_count(struct shrinker *shrink, 6921f3d90f90SSean Christopherson struct shrink_control *sc) 6922c50d8ae3SPaolo Bonzini { 6923c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6924c50d8ae3SPaolo Bonzini } 6925c50d8ae3SPaolo Bonzini 6926e5985c40SQi Zheng static struct shrinker *mmu_shrinker; 6927c50d8ae3SPaolo Bonzini 6928c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6929c50d8ae3SPaolo Bonzini { 6930c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6931c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6932c50d8ae3SPaolo Bonzini } 6933c50d8ae3SPaolo Bonzini 69340b210fafSSean Christopherson static int get_nx_huge_pages(char *buffer, const struct kernel_param *kp) 69350b210fafSSean Christopherson { 69360b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 69371d6664faSLike Xu return sysfs_emit(buffer, "never\n"); 69380b210fafSSean Christopherson 69390b210fafSSean Christopherson return param_get_bool(buffer, kp); 69400b210fafSSean Christopherson } 69410b210fafSSean Christopherson 6942c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6943c50d8ae3SPaolo Bonzini { 6944c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6945c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6946c50d8ae3SPaolo Bonzini } 6947c50d8ae3SPaolo Bonzini 6948c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6949c50d8ae3SPaolo Bonzini { 6950c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6951c50d8ae3SPaolo Bonzini } 6952c50d8ae3SPaolo Bonzini 6953c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6954c50d8ae3SPaolo Bonzini { 6955c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6956c50d8ae3SPaolo Bonzini bool new_val; 6957c50d8ae3SPaolo Bonzini 69580b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 69590b210fafSSean Christopherson return -EPERM; 69600b210fafSSean Christopherson 6961c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 69620b210fafSSean Christopherson if (sysfs_streq(val, "off")) { 6963c50d8ae3SPaolo Bonzini new_val = 0; 69640b210fafSSean Christopherson } else if (sysfs_streq(val, "force")) { 6965c50d8ae3SPaolo Bonzini new_val = 1; 69660b210fafSSean Christopherson } else if (sysfs_streq(val, "auto")) { 6967c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 69680b210fafSSean Christopherson } else if (sysfs_streq(val, "never")) { 69690b210fafSSean Christopherson new_val = 0; 69700b210fafSSean Christopherson 69710b210fafSSean Christopherson mutex_lock(&kvm_lock); 69720b210fafSSean Christopherson if (!list_empty(&vm_list)) { 69730b210fafSSean Christopherson mutex_unlock(&kvm_lock); 69740b210fafSSean Christopherson return -EBUSY; 69750b210fafSSean Christopherson } 69760b210fafSSean Christopherson nx_hugepage_mitigation_hard_disabled = true; 69770b210fafSSean Christopherson mutex_unlock(&kvm_lock); 69780b210fafSSean Christopherson } else if (kstrtobool(val, &new_val) < 0) { 6979c50d8ae3SPaolo Bonzini return -EINVAL; 69800b210fafSSean Christopherson } 6981c50d8ae3SPaolo Bonzini 6982c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6983c50d8ae3SPaolo Bonzini 6984c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6985c50d8ae3SPaolo Bonzini struct kvm *kvm; 6986c50d8ae3SPaolo Bonzini 6987c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6988c50d8ae3SPaolo Bonzini 6989c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6990c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6991c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6992c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6993c50d8ae3SPaolo Bonzini 699455c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 6995c50d8ae3SPaolo Bonzini } 6996c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6997c50d8ae3SPaolo Bonzini } 6998c50d8ae3SPaolo Bonzini 6999c50d8ae3SPaolo Bonzini return 0; 7000c50d8ae3SPaolo Bonzini } 7001c50d8ae3SPaolo Bonzini 70021d0e8480SSean Christopherson /* 70031d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 70041d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 7005c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 7006c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 70071d0e8480SSean Christopherson */ 7008982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 7009c50d8ae3SPaolo Bonzini { 7010c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 7011c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 7012c3e0c8c2SSean Christopherson 70131f98f2bdSDavid Matlack /* 70141f98f2bdSDavid Matlack * Snapshot userspace's desire to enable the TDP MMU. Whether or not the 70151f98f2bdSDavid Matlack * TDP MMU is actually enabled is determined in kvm_configure_mmu() 70161f98f2bdSDavid Matlack * when the vendor module is loaded. 70171f98f2bdSDavid Matlack */ 70181f98f2bdSDavid Matlack tdp_mmu_allowed = tdp_mmu_enabled; 70191f98f2bdSDavid Matlack 7020c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 70211d0e8480SSean Christopherson } 70221d0e8480SSean Christopherson 70231d0e8480SSean Christopherson /* 70241d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 70251d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 70261d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 70271d0e8480SSean Christopherson */ 70281d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 70291d0e8480SSean Christopherson { 70301d0e8480SSean Christopherson int ret = -ENOMEM; 7031c50d8ae3SPaolo Bonzini 7032c50d8ae3SPaolo Bonzini /* 7033c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 7034c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 7035c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 7036c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 7037c50d8ae3SPaolo Bonzini */ 7038c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 7039c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 70407a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 7041c50d8ae3SPaolo Bonzini 7042c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 7043c50d8ae3SPaolo Bonzini 70440dbd0546SKunwu Chan pte_list_desc_cache = KMEM_CACHE(pte_list_desc, SLAB_ACCOUNT); 7045c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 7046c50d8ae3SPaolo Bonzini goto out; 7047c50d8ae3SPaolo Bonzini 7048c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 7049c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 7050c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 7051c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 7052c50d8ae3SPaolo Bonzini goto out; 7053c50d8ae3SPaolo Bonzini 7054c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 7055c50d8ae3SPaolo Bonzini goto out; 7056c50d8ae3SPaolo Bonzini 7057e5985c40SQi Zheng mmu_shrinker = shrinker_alloc(0, "x86-mmu"); 7058e5985c40SQi Zheng if (!mmu_shrinker) 7059d7c9bfb9SMiaohe Lin goto out_shrinker; 7060c50d8ae3SPaolo Bonzini 7061e5985c40SQi Zheng mmu_shrinker->count_objects = mmu_shrink_count; 7062e5985c40SQi Zheng mmu_shrinker->scan_objects = mmu_shrink_scan; 7063e5985c40SQi Zheng mmu_shrinker->seeks = DEFAULT_SEEKS * 10; 7064e5985c40SQi Zheng 7065e5985c40SQi Zheng shrinker_register(mmu_shrinker); 7066e5985c40SQi Zheng 7067c50d8ae3SPaolo Bonzini return 0; 7068c50d8ae3SPaolo Bonzini 7069d7c9bfb9SMiaohe Lin out_shrinker: 7070d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 7071c50d8ae3SPaolo Bonzini out: 7072c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 7073c50d8ae3SPaolo Bonzini return ret; 7074c50d8ae3SPaolo Bonzini } 7075c50d8ae3SPaolo Bonzini 7076c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 7077c50d8ae3SPaolo Bonzini { 7078c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 7079c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 7080c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 7081c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 7082c50d8ae3SPaolo Bonzini } 7083c50d8ae3SPaolo Bonzini 70841d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 7085c50d8ae3SPaolo Bonzini { 7086c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 7087c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 7088e5985c40SQi Zheng shrinker_free(mmu_shrinker); 7089c50d8ae3SPaolo Bonzini } 7090c50d8ae3SPaolo Bonzini 7091f47491d7SSean Christopherson /* 7092f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 7093f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 7094f47491d7SSean Christopherson */ 7095f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 7096f47491d7SSean Christopherson { 7097f47491d7SSean Christopherson /* 7098f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 7099f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 7100f47491d7SSean Christopherson */ 7101f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 7102f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 7103f47491d7SSean Christopherson 7104f47491d7SSean Christopherson if (!enabled || !ratio) 7105f47491d7SSean Christopherson return false; 7106f47491d7SSean Christopherson 7107f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 7108f47491d7SSean Christopherson if (!*period) { 7109f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 7110f47491d7SSean Christopherson ratio = min(ratio, 3600u); 7111f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 7112f47491d7SSean Christopherson } 7113f47491d7SSean Christopherson return true; 7114f47491d7SSean Christopherson } 7115f47491d7SSean Christopherson 71164dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 7117c50d8ae3SPaolo Bonzini { 71184dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 71194dfe4f40SJunaid Shahid uint old_period, new_period; 7120c50d8ae3SPaolo Bonzini int err; 7121c50d8ae3SPaolo Bonzini 71220b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 71230b210fafSSean Christopherson return -EPERM; 71240b210fafSSean Christopherson 7125f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 71264dfe4f40SJunaid Shahid 7127c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 7128c50d8ae3SPaolo Bonzini if (err) 7129c50d8ae3SPaolo Bonzini return err; 7130c50d8ae3SPaolo Bonzini 7131f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 71324dfe4f40SJunaid Shahid 7133f47491d7SSean Christopherson if (is_recovery_enabled && 71344dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 7135c50d8ae3SPaolo Bonzini struct kvm *kvm; 7136c50d8ae3SPaolo Bonzini 7137c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 7138c50d8ae3SPaolo Bonzini 7139c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 714055c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 7141c50d8ae3SPaolo Bonzini 7142c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 7143c50d8ae3SPaolo Bonzini } 7144c50d8ae3SPaolo Bonzini 7145c50d8ae3SPaolo Bonzini return err; 7146c50d8ae3SPaolo Bonzini } 7147c50d8ae3SPaolo Bonzini 714855c510e2SSean Christopherson static void kvm_recover_nx_huge_pages(struct kvm *kvm) 7149c50d8ae3SPaolo Bonzini { 7150ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 7151eb298605SDavid Matlack struct kvm_memory_slot *slot; 7152c50d8ae3SPaolo Bonzini int rcu_idx; 7153c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 7154c50d8ae3SPaolo Bonzini unsigned int ratio; 7155c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 7156048f4980SSean Christopherson bool flush = false; 7157c50d8ae3SPaolo Bonzini ulong to_zap; 7158c50d8ae3SPaolo Bonzini 7159c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 7160531810caSBen Gardon write_lock(&kvm->mmu_lock); 7161c50d8ae3SPaolo Bonzini 7162bb95dfb9SSean Christopherson /* 7163bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 7164bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 7165bb95dfb9SSean Christopherson * callback. 7166bb95dfb9SSean Christopherson */ 7167bb95dfb9SSean Christopherson rcu_read_lock(); 7168bb95dfb9SSean Christopherson 7169c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 7170ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 71717d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 717255c510e2SSean Christopherson if (list_empty(&kvm->arch.possible_nx_huge_pages)) 71737d919c7aSSean Christopherson break; 71747d919c7aSSean Christopherson 7175c50d8ae3SPaolo Bonzini /* 7176c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 717755c510e2SSean Christopherson * because the number of shadow pages that be replaced with an 717855c510e2SSean Christopherson * NX huge page is expected to be relatively small compared to 717955c510e2SSean Christopherson * the total number of shadow pages. And because the TDP MMU 718055c510e2SSean Christopherson * doesn't use active_mmu_pages. 7181c50d8ae3SPaolo Bonzini */ 718255c510e2SSean Christopherson sp = list_first_entry(&kvm->arch.possible_nx_huge_pages, 7183c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 718455c510e2SSean Christopherson possible_nx_huge_page_link); 718555c510e2SSean Christopherson WARN_ON_ONCE(!sp->nx_huge_page_disallowed); 7186eb298605SDavid Matlack WARN_ON_ONCE(!sp->role.direct); 7187eb298605SDavid Matlack 7188eb298605SDavid Matlack /* 7189eb298605SDavid Matlack * Unaccount and do not attempt to recover any NX Huge Pages 7190eb298605SDavid Matlack * that are being dirty tracked, as they would just be faulted 7191eb298605SDavid Matlack * back in as 4KiB pages. The NX Huge Pages in this slot will be 7192eb298605SDavid Matlack * recovered, along with all the other huge pages in the slot, 7193eb298605SDavid Matlack * when dirty logging is disabled. 71946c7b2202SPaolo Bonzini * 71956c7b2202SPaolo Bonzini * Since gfn_to_memslot() is relatively expensive, it helps to 71966c7b2202SPaolo Bonzini * skip it if it the test cannot possibly return true. On the 71976c7b2202SPaolo Bonzini * other hand, if any memslot has logging enabled, chances are 71986c7b2202SPaolo Bonzini * good that all of them do, in which case unaccount_nx_huge_page() 71996c7b2202SPaolo Bonzini * is much cheaper than zapping the page. 72006c7b2202SPaolo Bonzini * 72016c7b2202SPaolo Bonzini * If a memslot update is in progress, reading an incorrect value 72026c7b2202SPaolo Bonzini * of kvm->nr_memslots_dirty_logging is not a problem: if it is 72036c7b2202SPaolo Bonzini * becoming zero, gfn_to_memslot() will be done unnecessarily; if 72046c7b2202SPaolo Bonzini * it is becoming nonzero, the page will be zapped unnecessarily. 72056c7b2202SPaolo Bonzini * Either way, this only affects efficiency in racy situations, 72066c7b2202SPaolo Bonzini * and not correctness. 7207eb298605SDavid Matlack */ 72086c7b2202SPaolo Bonzini slot = NULL; 72096c7b2202SPaolo Bonzini if (atomic_read(&kvm->nr_memslots_dirty_logging)) { 7210817fa998SSean Christopherson struct kvm_memslots *slots; 7211817fa998SSean Christopherson 7212817fa998SSean Christopherson slots = kvm_memslots_for_spte_role(kvm, sp->role); 7213817fa998SSean Christopherson slot = __gfn_to_memslot(slots, sp->gfn); 72146c7b2202SPaolo Bonzini WARN_ON_ONCE(!slot); 721529cf0f50SBen Gardon } 7216c50d8ae3SPaolo Bonzini 7217eb298605SDavid Matlack if (slot && kvm_slot_dirty_track_enabled(slot)) 7218eb298605SDavid Matlack unaccount_nx_huge_page(kvm, sp); 7219eb298605SDavid Matlack else if (is_tdp_mmu_page(sp)) 7220c50d8ae3SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 72213a056757SSean Christopherson else 7222c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 722355c510e2SSean Christopherson WARN_ON_ONCE(sp->nx_huge_page_disallowed); 7224c50d8ae3SPaolo Bonzini 7225531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 7226048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7227bb95dfb9SSean Christopherson rcu_read_unlock(); 7228bb95dfb9SSean Christopherson 7229531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 7230048f4980SSean Christopherson flush = false; 7231bb95dfb9SSean Christopherson 7232bb95dfb9SSean Christopherson rcu_read_lock(); 7233c50d8ae3SPaolo Bonzini } 7234c50d8ae3SPaolo Bonzini } 7235048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7236c50d8ae3SPaolo Bonzini 7237bb95dfb9SSean Christopherson rcu_read_unlock(); 7238bb95dfb9SSean Christopherson 7239531810caSBen Gardon write_unlock(&kvm->mmu_lock); 7240c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 7241c50d8ae3SPaolo Bonzini } 7242c50d8ae3SPaolo Bonzini 724355c510e2SSean Christopherson static long get_nx_huge_page_recovery_timeout(u64 start_time) 7244c50d8ae3SPaolo Bonzini { 7245f47491d7SSean Christopherson bool enabled; 7246f47491d7SSean Christopherson uint period; 72474dfe4f40SJunaid Shahid 7248f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 72494dfe4f40SJunaid Shahid 7250f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 7251c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 7252c50d8ae3SPaolo Bonzini } 7253c50d8ae3SPaolo Bonzini 725455c510e2SSean Christopherson static int kvm_nx_huge_page_recovery_worker(struct kvm *kvm, uintptr_t data) 7255c50d8ae3SPaolo Bonzini { 7256c50d8ae3SPaolo Bonzini u64 start_time; 7257c50d8ae3SPaolo Bonzini long remaining_time; 7258c50d8ae3SPaolo Bonzini 7259c50d8ae3SPaolo Bonzini while (true) { 7260c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 726155c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7262c50d8ae3SPaolo Bonzini 7263c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7264c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 7265c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 726655c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7267c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7268c50d8ae3SPaolo Bonzini } 7269c50d8ae3SPaolo Bonzini 7270c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 7271c50d8ae3SPaolo Bonzini 7272c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 7273c50d8ae3SPaolo Bonzini return 0; 7274c50d8ae3SPaolo Bonzini 727555c510e2SSean Christopherson kvm_recover_nx_huge_pages(kvm); 7276c50d8ae3SPaolo Bonzini } 7277c50d8ae3SPaolo Bonzini } 7278c50d8ae3SPaolo Bonzini 7279c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 7280c50d8ae3SPaolo Bonzini { 7281c50d8ae3SPaolo Bonzini int err; 7282c50d8ae3SPaolo Bonzini 72830b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 72840b210fafSSean Christopherson return 0; 72850b210fafSSean Christopherson 728655c510e2SSean Christopherson err = kvm_vm_create_worker_thread(kvm, kvm_nx_huge_page_recovery_worker, 0, 7287c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 728855c510e2SSean Christopherson &kvm->arch.nx_huge_page_recovery_thread); 7289c50d8ae3SPaolo Bonzini if (!err) 729055c510e2SSean Christopherson kthread_unpark(kvm->arch.nx_huge_page_recovery_thread); 7291c50d8ae3SPaolo Bonzini 7292c50d8ae3SPaolo Bonzini return err; 7293c50d8ae3SPaolo Bonzini } 7294c50d8ae3SPaolo Bonzini 7295c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 7296c50d8ae3SPaolo Bonzini { 729755c510e2SSean Christopherson if (kvm->arch.nx_huge_page_recovery_thread) 729855c510e2SSean Christopherson kthread_stop(kvm->arch.nx_huge_page_recovery_thread); 7299c50d8ae3SPaolo Bonzini } 730090b4fe17SChao Peng 730190b4fe17SChao Peng #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES 73028dd2eee9SChao Peng bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm, 73038dd2eee9SChao Peng struct kvm_gfn_range *range) 73048dd2eee9SChao Peng { 73058dd2eee9SChao Peng /* 73068dd2eee9SChao Peng * Zap SPTEs even if the slot can't be mapped PRIVATE. KVM x86 only 73078dd2eee9SChao Peng * supports KVM_MEMORY_ATTRIBUTE_PRIVATE, and so it *seems* like KVM 73088dd2eee9SChao Peng * can simply ignore such slots. But if userspace is making memory 73098dd2eee9SChao Peng * PRIVATE, then KVM must prevent the guest from accessing the memory 73108dd2eee9SChao Peng * as shared. And if userspace is making memory SHARED and this point 73118dd2eee9SChao Peng * is reached, then at least one page within the range was previously 73128dd2eee9SChao Peng * PRIVATE, i.e. the slot's possible hugepage ranges are changing. 73138dd2eee9SChao Peng * Zapping SPTEs in this case ensures KVM will reassess whether or not 73148dd2eee9SChao Peng * a hugepage can be used for affected ranges. 73158dd2eee9SChao Peng */ 73168dd2eee9SChao Peng if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm))) 73178dd2eee9SChao Peng return false; 73188dd2eee9SChao Peng 73198dd2eee9SChao Peng return kvm_unmap_gfn_range(kvm, range); 73208dd2eee9SChao Peng } 73218dd2eee9SChao Peng 732290b4fe17SChao Peng static bool hugepage_test_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 732390b4fe17SChao Peng int level) 732490b4fe17SChao Peng { 732590b4fe17SChao Peng return lpage_info_slot(gfn, slot, level)->disallow_lpage & KVM_LPAGE_MIXED_FLAG; 732690b4fe17SChao Peng } 732790b4fe17SChao Peng 732890b4fe17SChao Peng static void hugepage_clear_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 732990b4fe17SChao Peng int level) 733090b4fe17SChao Peng { 733190b4fe17SChao Peng lpage_info_slot(gfn, slot, level)->disallow_lpage &= ~KVM_LPAGE_MIXED_FLAG; 733290b4fe17SChao Peng } 733390b4fe17SChao Peng 733490b4fe17SChao Peng static void hugepage_set_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 733590b4fe17SChao Peng int level) 733690b4fe17SChao Peng { 733790b4fe17SChao Peng lpage_info_slot(gfn, slot, level)->disallow_lpage |= KVM_LPAGE_MIXED_FLAG; 733890b4fe17SChao Peng } 733990b4fe17SChao Peng 734090b4fe17SChao Peng static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot, 734190b4fe17SChao Peng gfn_t gfn, int level, unsigned long attrs) 734290b4fe17SChao Peng { 734390b4fe17SChao Peng const unsigned long start = gfn; 734490b4fe17SChao Peng const unsigned long end = start + KVM_PAGES_PER_HPAGE(level); 734590b4fe17SChao Peng 734690b4fe17SChao Peng if (level == PG_LEVEL_2M) 734790b4fe17SChao Peng return kvm_range_has_memory_attributes(kvm, start, end, attrs); 734890b4fe17SChao Peng 734990b4fe17SChao Peng for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) { 735090b4fe17SChao Peng if (hugepage_test_mixed(slot, gfn, level - 1) || 735190b4fe17SChao Peng attrs != kvm_get_memory_attributes(kvm, gfn)) 735290b4fe17SChao Peng return false; 735390b4fe17SChao Peng } 735490b4fe17SChao Peng return true; 735590b4fe17SChao Peng } 735690b4fe17SChao Peng 735790b4fe17SChao Peng bool kvm_arch_post_set_memory_attributes(struct kvm *kvm, 735890b4fe17SChao Peng struct kvm_gfn_range *range) 735990b4fe17SChao Peng { 736090b4fe17SChao Peng unsigned long attrs = range->arg.attributes; 736190b4fe17SChao Peng struct kvm_memory_slot *slot = range->slot; 736290b4fe17SChao Peng int level; 736390b4fe17SChao Peng 736490b4fe17SChao Peng lockdep_assert_held_write(&kvm->mmu_lock); 736590b4fe17SChao Peng lockdep_assert_held(&kvm->slots_lock); 736690b4fe17SChao Peng 736790b4fe17SChao Peng /* 736890b4fe17SChao Peng * Calculate which ranges can be mapped with hugepages even if the slot 736990b4fe17SChao Peng * can't map memory PRIVATE. KVM mustn't create a SHARED hugepage over 737090b4fe17SChao Peng * a range that has PRIVATE GFNs, and conversely converting a range to 737190b4fe17SChao Peng * SHARED may now allow hugepages. 737290b4fe17SChao Peng */ 737390b4fe17SChao Peng if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm))) 737490b4fe17SChao Peng return false; 737590b4fe17SChao Peng 737690b4fe17SChao Peng /* 737790b4fe17SChao Peng * The sequence matters here: upper levels consume the result of lower 737890b4fe17SChao Peng * level's scanning. 737990b4fe17SChao Peng */ 738090b4fe17SChao Peng for (level = PG_LEVEL_2M; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) { 738190b4fe17SChao Peng gfn_t nr_pages = KVM_PAGES_PER_HPAGE(level); 738290b4fe17SChao Peng gfn_t gfn = gfn_round_for_level(range->start, level); 738390b4fe17SChao Peng 738490b4fe17SChao Peng /* Process the head page if it straddles the range. */ 738590b4fe17SChao Peng if (gfn != range->start || gfn + nr_pages > range->end) { 738690b4fe17SChao Peng /* 738790b4fe17SChao Peng * Skip mixed tracking if the aligned gfn isn't covered 738890b4fe17SChao Peng * by the memslot, KVM can't use a hugepage due to the 738990b4fe17SChao Peng * misaligned address regardless of memory attributes. 739090b4fe17SChao Peng */ 739190b4fe17SChao Peng if (gfn >= slot->base_gfn) { 739290b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 739390b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 739490b4fe17SChao Peng else 739590b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 739690b4fe17SChao Peng } 739790b4fe17SChao Peng gfn += nr_pages; 739890b4fe17SChao Peng } 739990b4fe17SChao Peng 740090b4fe17SChao Peng /* 740190b4fe17SChao Peng * Pages entirely covered by the range are guaranteed to have 740290b4fe17SChao Peng * only the attributes which were just set. 740390b4fe17SChao Peng */ 740490b4fe17SChao Peng for ( ; gfn + nr_pages <= range->end; gfn += nr_pages) 740590b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 740690b4fe17SChao Peng 740790b4fe17SChao Peng /* 740890b4fe17SChao Peng * Process the last tail page if it straddles the range and is 740990b4fe17SChao Peng * contained by the memslot. Like the head page, KVM can't 741090b4fe17SChao Peng * create a hugepage if the slot size is misaligned. 741190b4fe17SChao Peng */ 741290b4fe17SChao Peng if (gfn < range->end && 741390b4fe17SChao Peng (gfn + nr_pages) <= (slot->base_gfn + slot->npages)) { 741490b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 741590b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 741690b4fe17SChao Peng else 741790b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 741890b4fe17SChao Peng } 741990b4fe17SChao Peng } 742090b4fe17SChao Peng return false; 742190b4fe17SChao Peng } 742290b4fe17SChao Peng 742390b4fe17SChao Peng void kvm_mmu_init_memslot_memory_attributes(struct kvm *kvm, 742490b4fe17SChao Peng struct kvm_memory_slot *slot) 742590b4fe17SChao Peng { 742690b4fe17SChao Peng int level; 742790b4fe17SChao Peng 742890b4fe17SChao Peng if (!kvm_arch_has_private_mem(kvm)) 742990b4fe17SChao Peng return; 743090b4fe17SChao Peng 743190b4fe17SChao Peng for (level = PG_LEVEL_2M; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) { 743290b4fe17SChao Peng /* 743390b4fe17SChao Peng * Don't bother tracking mixed attributes for pages that can't 743490b4fe17SChao Peng * be huge due to alignment, i.e. process only pages that are 743590b4fe17SChao Peng * entirely contained by the memslot. 743690b4fe17SChao Peng */ 743790b4fe17SChao Peng gfn_t end = gfn_round_for_level(slot->base_gfn + slot->npages, level); 743890b4fe17SChao Peng gfn_t start = gfn_round_for_level(slot->base_gfn, level); 743990b4fe17SChao Peng gfn_t nr_pages = KVM_PAGES_PER_HPAGE(level); 744090b4fe17SChao Peng gfn_t gfn; 744190b4fe17SChao Peng 744290b4fe17SChao Peng if (start < slot->base_gfn) 744390b4fe17SChao Peng start += nr_pages; 744490b4fe17SChao Peng 744590b4fe17SChao Peng /* 744690b4fe17SChao Peng * Unlike setting attributes, every potential hugepage needs to 744790b4fe17SChao Peng * be manually checked as the attributes may already be mixed. 744890b4fe17SChao Peng */ 744990b4fe17SChao Peng for (gfn = start; gfn < end; gfn += nr_pages) { 745090b4fe17SChao Peng unsigned long attrs = kvm_get_memory_attributes(kvm, gfn); 745190b4fe17SChao Peng 745290b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 745390b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 745490b4fe17SChao Peng else 745590b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 745690b4fe17SChao Peng } 745790b4fe17SChao Peng } 745890b4fe17SChao Peng } 745990b4fe17SChao Peng #endif 7460