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 * 435aed02fe3SSean Christopherson * An spte tlb flush may be pending, because kvm_set_pte_rmap 436c50d8ae3SPaolo Bonzini * coalesces them and 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, 1451c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14523039bcc7SSean Christopherson pte_t unused) 1453c50d8ae3SPaolo Bonzini { 1454f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1455c50d8ae3SPaolo Bonzini } 1456c50d8ae3SPaolo Bonzini 1457aed02fe3SSean Christopherson static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1458c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14593039bcc7SSean Christopherson pte_t pte) 1460c50d8ae3SPaolo Bonzini { 1461c50d8ae3SPaolo Bonzini u64 *sptep; 1462c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 146398a26b69SVihas Mak bool need_flush = false; 1464c50d8ae3SPaolo Bonzini u64 new_spte; 1465c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1466c50d8ae3SPaolo Bonzini 146720ba462dSSean Christopherson WARN_ON_ONCE(pte_huge(pte)); 14683039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1469c50d8ae3SPaolo Bonzini 1470c50d8ae3SPaolo Bonzini restart: 1471c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 147298a26b69SVihas Mak need_flush = true; 1473c50d8ae3SPaolo Bonzini 14743039bcc7SSean Christopherson if (pte_write(pte)) { 14759202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 1476c50d8ae3SPaolo Bonzini goto restart; 1477c50d8ae3SPaolo Bonzini } else { 1478cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1479cb3eedabSPaolo Bonzini *sptep, new_pfn); 1480c50d8ae3SPaolo Bonzini 148171f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1482c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1483c50d8ae3SPaolo Bonzini } 1484c50d8ae3SPaolo Bonzini } 1485c50d8ae3SPaolo Bonzini 14868a1300ffSSean Christopherson if (need_flush && kvm_available_flush_remote_tlbs_range()) { 14879ffe9265SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, level); 148898a26b69SVihas Mak return false; 1489c50d8ae3SPaolo Bonzini } 1490c50d8ae3SPaolo Bonzini 1491c50d8ae3SPaolo Bonzini return need_flush; 1492c50d8ae3SPaolo Bonzini } 1493c50d8ae3SPaolo Bonzini 1494c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1495c50d8ae3SPaolo Bonzini /* input fields. */ 1496269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1497c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1498c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1499c50d8ae3SPaolo Bonzini int start_level; 1500c50d8ae3SPaolo Bonzini int end_level; 1501c50d8ae3SPaolo Bonzini 1502c50d8ae3SPaolo Bonzini /* output fields. */ 1503c50d8ae3SPaolo Bonzini gfn_t gfn; 1504c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1505c50d8ae3SPaolo Bonzini int level; 1506c50d8ae3SPaolo Bonzini 1507c50d8ae3SPaolo Bonzini /* private field. */ 1508c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1509c50d8ae3SPaolo Bonzini }; 1510c50d8ae3SPaolo Bonzini 1511f3d90f90SSean Christopherson static void rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, 1512f3d90f90SSean Christopherson int level) 1513c50d8ae3SPaolo Bonzini { 1514c50d8ae3SPaolo Bonzini iterator->level = level; 1515c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 151693e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 151793e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1518c50d8ae3SPaolo Bonzini } 1519c50d8ae3SPaolo Bonzini 1520f3d90f90SSean Christopherson static void slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1521f3d90f90SSean Christopherson const struct kvm_memory_slot *slot, 1522f3d90f90SSean Christopherson int start_level, int end_level, 1523f3d90f90SSean Christopherson gfn_t start_gfn, gfn_t end_gfn) 1524c50d8ae3SPaolo Bonzini { 1525c50d8ae3SPaolo Bonzini iterator->slot = slot; 1526c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1527c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1528c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1529c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1530c50d8ae3SPaolo Bonzini 1531c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1532c50d8ae3SPaolo Bonzini } 1533c50d8ae3SPaolo Bonzini 1534c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1535c50d8ae3SPaolo Bonzini { 1536c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1537c50d8ae3SPaolo Bonzini } 1538c50d8ae3SPaolo Bonzini 1539c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1540c50d8ae3SPaolo Bonzini { 15416ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1542c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 15436ba1e04fSVipin Sharma 15446ba1e04fSVipin Sharma if (iterator->rmap->val) 1545c50d8ae3SPaolo Bonzini return; 1546c50d8ae3SPaolo Bonzini } 1547c50d8ae3SPaolo Bonzini 1548c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1549c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1550c50d8ae3SPaolo Bonzini return; 1551c50d8ae3SPaolo Bonzini } 1552c50d8ae3SPaolo Bonzini 1553c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1554c50d8ae3SPaolo Bonzini } 1555c50d8ae3SPaolo Bonzini 1556c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1557c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1558c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1559c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1560c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1561c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1562c50d8ae3SPaolo Bonzini 15633039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1564c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15653039bcc7SSean Christopherson int level, pte_t pte); 1566c1b91493SSean Christopherson 15673039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15683039bcc7SSean Christopherson struct kvm_gfn_range *range, 1569c1b91493SSean Christopherson rmap_handler_t handler) 1570c50d8ae3SPaolo Bonzini { 1571c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15723039bcc7SSean Christopherson bool ret = false; 1573c50d8ae3SPaolo Bonzini 15743039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15753039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15763039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15773e1efe2bSSean Christopherson iterator.level, range->arg.pte); 1578c50d8ae3SPaolo Bonzini 1579c50d8ae3SPaolo Bonzini return ret; 1580c50d8ae3SPaolo Bonzini } 1581c50d8ae3SPaolo Bonzini 15823039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1583c50d8ae3SPaolo Bonzini { 1584e2209710SBen Gardon bool flush = false; 1585c50d8ae3SPaolo Bonzini 1586e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1587f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1588063afacdSBen Gardon 15891f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1590c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1591063afacdSBen Gardon 15920a3869e1SSean Christopherson if (kvm_x86_ops.set_apic_access_page_addr && 15930a3869e1SSean Christopherson range->slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT) 15940a8a5f2cSSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); 15950a8a5f2cSSean Christopherson 15963039bcc7SSean Christopherson return flush; 1597c50d8ae3SPaolo Bonzini } 1598c50d8ae3SPaolo Bonzini 15993039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1600c50d8ae3SPaolo Bonzini { 1601e2209710SBen Gardon bool flush = false; 16021d8dd6b3SBen Gardon 1603e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1604aed02fe3SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); 16051d8dd6b3SBen Gardon 16061f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16073039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 16081d8dd6b3SBen Gardon 16093039bcc7SSean Christopherson return flush; 1610c50d8ae3SPaolo Bonzini } 1611c50d8ae3SPaolo Bonzini 1612aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1613c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 16143039bcc7SSean Christopherson pte_t unused) 1615c50d8ae3SPaolo Bonzini { 1616c50d8ae3SPaolo Bonzini u64 *sptep; 16173f649ab7SKees Cook struct rmap_iterator iter; 1618c50d8ae3SPaolo Bonzini int young = 0; 1619c50d8ae3SPaolo Bonzini 1620c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1621c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1622c50d8ae3SPaolo Bonzini 1623c50d8ae3SPaolo Bonzini return young; 1624c50d8ae3SPaolo Bonzini } 1625c50d8ae3SPaolo Bonzini 1626aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1627c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 16283039bcc7SSean Christopherson int level, pte_t unused) 1629c50d8ae3SPaolo Bonzini { 1630c50d8ae3SPaolo Bonzini u64 *sptep; 1631c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1632c50d8ae3SPaolo Bonzini 1633c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1634c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 163598a26b69SVihas Mak return true; 163698a26b69SVihas Mak return false; 1637c50d8ae3SPaolo Bonzini } 1638c50d8ae3SPaolo Bonzini 1639c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1640c50d8ae3SPaolo Bonzini 16412ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 16422ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 16432ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 164472ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1645c50d8ae3SPaolo Bonzini { 1646c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 164768be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 164868be1306SDavid Matlack int rmap_count; 1649c50d8ae3SPaolo Bonzini 165057354682SSean Christopherson sp = sptep_to_sp(spte); 165179e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 165281cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 165381cb4657SDavid Matlack 165493e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 16552ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1656c50d8ae3SPaolo Bonzini 1657604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1658604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 165968be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16609202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 16611b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 166268be1306SDavid Matlack } 1663c50d8ae3SPaolo Bonzini } 1664c50d8ae3SPaolo Bonzini 16652ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 166672ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16672ff9039aSDavid Matlack { 16682ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16692ff9039aSDavid Matlack 16706a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16712ff9039aSDavid Matlack } 16722ff9039aSDavid Matlack 16733039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1674c50d8ae3SPaolo Bonzini { 1675e2209710SBen Gardon bool young = false; 1676f8e14497SBen Gardon 1677e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1678aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16793039bcc7SSean Christopherson 16801f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16813039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1682f8e14497SBen Gardon 1683f8e14497SBen Gardon return young; 1684c50d8ae3SPaolo Bonzini } 1685c50d8ae3SPaolo Bonzini 16863039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1687c50d8ae3SPaolo Bonzini { 1688e2209710SBen Gardon bool young = false; 1689f8e14497SBen Gardon 1690e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1691aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 16923039bcc7SSean Christopherson 16931f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16943039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1695f8e14497SBen Gardon 1696f8e14497SBen Gardon return young; 1697c50d8ae3SPaolo Bonzini } 1698c50d8ae3SPaolo Bonzini 169958da926cSSean Christopherson static void kvm_mmu_check_sptes_at_free(struct kvm_mmu_page *sp) 1700c50d8ae3SPaolo Bonzini { 1701870d4d4eSSean Christopherson #ifdef CONFIG_KVM_PROVE_MMU 1702242a6dd8SSean Christopherson int i; 1703c50d8ae3SPaolo Bonzini 1704242a6dd8SSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 17050fe6370eSSean Christopherson if (KVM_MMU_WARN_ON(is_shadow_present_pte(sp->spt[i]))) 170658da926cSSean Christopherson pr_err_ratelimited("SPTE %llx (@ %p) for gfn %llx shadow-present at free", 170758da926cSSean Christopherson sp->spt[i], &sp->spt[i], 170858da926cSSean Christopherson kvm_mmu_page_get_gfn(sp, i)); 1709c50d8ae3SPaolo Bonzini } 1710c50d8ae3SPaolo Bonzini #endif 171158da926cSSean Christopherson } 1712c50d8ae3SPaolo Bonzini 1713c50d8ae3SPaolo Bonzini /* 1714c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1715c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1716c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1717c50d8ae3SPaolo Bonzini * faster 1718c50d8ae3SPaolo Bonzini */ 1719d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1720c50d8ae3SPaolo Bonzini { 1721c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1722c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1723c50d8ae3SPaolo Bonzini } 1724c50d8ae3SPaolo Bonzini 172543a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 172643a063caSYosry Ahmed { 172743a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 172843a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 172943a063caSYosry Ahmed } 173043a063caSYosry Ahmed 173143a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 173243a063caSYosry Ahmed { 173343a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 173443a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 173543a063caSYosry Ahmed } 173643a063caSYosry Ahmed 173787654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1738c50d8ae3SPaolo Bonzini { 173958da926cSSean Christopherson kvm_mmu_check_sptes_at_free(sp); 174058da926cSSean Christopherson 1741c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1742c50d8ae3SPaolo Bonzini list_del(&sp->link); 1743c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1744c50d8ae3SPaolo Bonzini if (!sp->role.direct) 17456a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1746c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1747c50d8ae3SPaolo Bonzini } 1748c50d8ae3SPaolo Bonzini 1749c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1750c50d8ae3SPaolo Bonzini { 1751c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1752c50d8ae3SPaolo Bonzini } 1753c50d8ae3SPaolo Bonzini 17542ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1755c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1756c50d8ae3SPaolo Bonzini { 1757c50d8ae3SPaolo Bonzini if (!parent_pte) 1758c50d8ae3SPaolo Bonzini return; 1759c50d8ae3SPaolo Bonzini 17602ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1761c50d8ae3SPaolo Bonzini } 1762c50d8ae3SPaolo Bonzini 1763069f30c6SMingwei Zhang static void mmu_page_remove_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 1764c50d8ae3SPaolo Bonzini u64 *parent_pte) 1765c50d8ae3SPaolo Bonzini { 1766069f30c6SMingwei Zhang pte_list_remove(kvm, parent_pte, &sp->parent_ptes); 1767c50d8ae3SPaolo Bonzini } 1768c50d8ae3SPaolo Bonzini 1769069f30c6SMingwei Zhang static void drop_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 1770c50d8ae3SPaolo Bonzini u64 *parent_pte) 1771c50d8ae3SPaolo Bonzini { 1772069f30c6SMingwei Zhang mmu_page_remove_parent_pte(kvm, sp, parent_pte); 1773c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1774c50d8ae3SPaolo Bonzini } 1775c50d8ae3SPaolo Bonzini 1776c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1777c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1778c50d8ae3SPaolo Bonzini { 1779c50d8ae3SPaolo Bonzini u64 *sptep; 1780c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1781c50d8ae3SPaolo Bonzini 1782c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1783c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1784c50d8ae3SPaolo Bonzini } 1785c50d8ae3SPaolo Bonzini } 1786c50d8ae3SPaolo Bonzini 1787c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1788c50d8ae3SPaolo Bonzini { 1789c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1790c50d8ae3SPaolo Bonzini 179157354682SSean Christopherson sp = sptep_to_sp(spte); 179279e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1793c50d8ae3SPaolo Bonzini return; 1794c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1795c50d8ae3SPaolo Bonzini return; 1796c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1797c50d8ae3SPaolo Bonzini } 1798c50d8ae3SPaolo Bonzini 1799c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1800c50d8ae3SPaolo Bonzini 1801c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1802c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1803c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1804c50d8ae3SPaolo Bonzini unsigned int idx; 1805c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1806c50d8ae3SPaolo Bonzini unsigned int nr; 1807c50d8ae3SPaolo Bonzini }; 1808c50d8ae3SPaolo Bonzini 1809c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1810c50d8ae3SPaolo Bonzini int idx) 1811c50d8ae3SPaolo Bonzini { 1812c50d8ae3SPaolo Bonzini int i; 1813c50d8ae3SPaolo Bonzini 1814c50d8ae3SPaolo Bonzini if (sp->unsync) 1815c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1816c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1817c50d8ae3SPaolo Bonzini return 0; 1818c50d8ae3SPaolo Bonzini 1819c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1820c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1821c50d8ae3SPaolo Bonzini pvec->nr++; 1822c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1823c50d8ae3SPaolo Bonzini } 1824c50d8ae3SPaolo Bonzini 1825c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1826c50d8ae3SPaolo Bonzini { 1827c50d8ae3SPaolo Bonzini --sp->unsync_children; 182820ba462dSSean Christopherson WARN_ON_ONCE((int)sp->unsync_children < 0); 1829c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1830c50d8ae3SPaolo Bonzini } 1831c50d8ae3SPaolo Bonzini 1832c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1833c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1834c50d8ae3SPaolo Bonzini { 1835c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1836c50d8ae3SPaolo Bonzini 1837c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1838c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1839c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1840c50d8ae3SPaolo Bonzini 1841c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1842c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1843c50d8ae3SPaolo Bonzini continue; 1844c50d8ae3SPaolo Bonzini } 1845c50d8ae3SPaolo Bonzini 18465e3edd7eSSean Christopherson child = spte_to_child_sp(ent); 1847c50d8ae3SPaolo Bonzini 1848c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1849c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1850c50d8ae3SPaolo Bonzini return -ENOSPC; 1851c50d8ae3SPaolo Bonzini 1852c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1853c50d8ae3SPaolo Bonzini if (!ret) { 1854c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1855c50d8ae3SPaolo Bonzini continue; 1856c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1857c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1858c50d8ae3SPaolo Bonzini } else 1859c50d8ae3SPaolo Bonzini return ret; 1860c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1861c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1862c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1863c50d8ae3SPaolo Bonzini return -ENOSPC; 1864c50d8ae3SPaolo Bonzini } else 1865c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1866c50d8ae3SPaolo Bonzini } 1867c50d8ae3SPaolo Bonzini 1868c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1869c50d8ae3SPaolo Bonzini } 1870c50d8ae3SPaolo Bonzini 1871c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1872c50d8ae3SPaolo Bonzini 1873c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1874c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1875c50d8ae3SPaolo Bonzini { 1876c50d8ae3SPaolo Bonzini pvec->nr = 0; 1877c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1878c50d8ae3SPaolo Bonzini return 0; 1879c50d8ae3SPaolo Bonzini 1880c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1881c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1882c50d8ae3SPaolo Bonzini } 1883c50d8ae3SPaolo Bonzini 1884c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1885c50d8ae3SPaolo Bonzini { 188620ba462dSSean Christopherson WARN_ON_ONCE(!sp->unsync); 1887c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1888c50d8ae3SPaolo Bonzini sp->unsync = 0; 1889c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1890c50d8ae3SPaolo Bonzini } 1891c50d8ae3SPaolo Bonzini 1892c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1893c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1894c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1895c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1896c50d8ae3SPaolo Bonzini 1897767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1898767d8d8dSLai Jiangshan { 1899767d8d8dSLai Jiangshan if (sp->role.direct) 1900767d8d8dSLai Jiangshan return false; 1901767d8d8dSLai Jiangshan 190284e5ffd0SLai Jiangshan if (sp->role.passthrough) 190384e5ffd0SLai Jiangshan return false; 190484e5ffd0SLai Jiangshan 1905767d8d8dSLai Jiangshan return true; 1906767d8d8dSLai Jiangshan } 1907767d8d8dSLai Jiangshan 1908ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1909ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1910c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1911c50d8ae3SPaolo Bonzini } else 1912c50d8ae3SPaolo Bonzini 1913767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1914ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1915ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1916767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1917c50d8ae3SPaolo Bonzini 191890e44470SLai Jiangshan static bool kvm_sync_page_check(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 191990e44470SLai Jiangshan { 192090e44470SLai Jiangshan union kvm_mmu_page_role root_role = vcpu->arch.mmu->root_role; 192190e44470SLai Jiangshan 192290e44470SLai Jiangshan /* 192390e44470SLai Jiangshan * Ignore various flags when verifying that it's safe to sync a shadow 192490e44470SLai Jiangshan * page using the current MMU context. 192590e44470SLai Jiangshan * 192690e44470SLai Jiangshan * - level: not part of the overall MMU role and will never match as the MMU's 192790e44470SLai Jiangshan * level tracks the root level 192890e44470SLai Jiangshan * - access: updated based on the new guest PTE 192990e44470SLai Jiangshan * - quadrant: not part of the overall MMU role (similar to level) 193090e44470SLai Jiangshan */ 193190e44470SLai Jiangshan const union kvm_mmu_page_role sync_role_ign = { 193290e44470SLai Jiangshan .level = 0xf, 193390e44470SLai Jiangshan .access = 0x7, 193490e44470SLai Jiangshan .quadrant = 0x3, 193590e44470SLai Jiangshan .passthrough = 0x1, 193690e44470SLai Jiangshan }; 193790e44470SLai Jiangshan 193890e44470SLai Jiangshan /* 193990e44470SLai Jiangshan * Direct pages can never be unsync, and KVM should never attempt to 194090e44470SLai Jiangshan * sync a shadow page for a different MMU context, e.g. if the role 194190e44470SLai Jiangshan * differs then the memslot lookup (SMM vs. non-SMM) will be bogus, the 194290e44470SLai Jiangshan * reserved bits checks will be wrong, etc... 194390e44470SLai Jiangshan */ 1944c3c6c9fcSLai Jiangshan if (WARN_ON_ONCE(sp->role.direct || !vcpu->arch.mmu->sync_spte || 194590e44470SLai Jiangshan (sp->role.word ^ root_role.word) & ~sync_role_ign.word)) 194690e44470SLai Jiangshan return false; 194790e44470SLai Jiangshan 194890e44470SLai Jiangshan return true; 194990e44470SLai Jiangshan } 195090e44470SLai Jiangshan 195119ace7d6SLai Jiangshan static int kvm_sync_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int i) 195219ace7d6SLai Jiangshan { 195319ace7d6SLai Jiangshan if (!sp->spt[i]) 195419ace7d6SLai Jiangshan return 0; 195519ace7d6SLai Jiangshan 195619ace7d6SLai Jiangshan return vcpu->arch.mmu->sync_spte(vcpu, sp, i); 195719ace7d6SLai Jiangshan } 195819ace7d6SLai Jiangshan 195990e44470SLai Jiangshan static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 196090e44470SLai Jiangshan { 1961c3c6c9fcSLai Jiangshan int flush = 0; 1962c3c6c9fcSLai Jiangshan int i; 1963c3c6c9fcSLai Jiangshan 196490e44470SLai Jiangshan if (!kvm_sync_page_check(vcpu, sp)) 196590e44470SLai Jiangshan return -1; 196690e44470SLai Jiangshan 1967c3c6c9fcSLai Jiangshan for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 196819ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, i); 1969c3c6c9fcSLai Jiangshan 1970c3c6c9fcSLai Jiangshan if (ret < -1) 1971c3c6c9fcSLai Jiangshan return -1; 1972c3c6c9fcSLai Jiangshan flush |= ret; 1973c3c6c9fcSLai Jiangshan } 1974c3c6c9fcSLai Jiangshan 1975c3c6c9fcSLai Jiangshan /* 1976c3c6c9fcSLai Jiangshan * Note, any flush is purely for KVM's correctness, e.g. when dropping 1977c3c6c9fcSLai Jiangshan * an existing SPTE or clearing W/A/D bits to ensure an mmu_notifier 1978c3c6c9fcSLai Jiangshan * unmap or dirty logging event doesn't fail to flush. The guest is 1979c3c6c9fcSLai Jiangshan * responsible for flushing the TLB to ensure any changes in protection 1980c3c6c9fcSLai Jiangshan * bits are recognized, i.e. until the guest flushes or page faults on 1981c3c6c9fcSLai Jiangshan * a relevant address, KVM is architecturally allowed to let vCPUs use 1982c3c6c9fcSLai Jiangshan * cached translations with the old protection bits. 1983c3c6c9fcSLai Jiangshan */ 1984c3c6c9fcSLai Jiangshan return flush; 198590e44470SLai Jiangshan } 198690e44470SLai Jiangshan 19878d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1988c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1989c50d8ae3SPaolo Bonzini { 199090e44470SLai Jiangshan int ret = __kvm_sync_page(vcpu, sp); 1991c3e5e415SLai Jiangshan 19928d5678a7SHou Wenlong if (ret < 0) 1993c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 19948d5678a7SHou Wenlong return ret; 1995c50d8ae3SPaolo Bonzini } 1996c50d8ae3SPaolo Bonzini 1997c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1998c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1999c50d8ae3SPaolo Bonzini bool remote_flush) 2000c50d8ae3SPaolo Bonzini { 2001c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 2002c50d8ae3SPaolo Bonzini return false; 2003c50d8ae3SPaolo Bonzini 2004c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 2005c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 2006c50d8ae3SPaolo Bonzini else 2007c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2008c50d8ae3SPaolo Bonzini return true; 2009c50d8ae3SPaolo Bonzini } 2010c50d8ae3SPaolo Bonzini 2011c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 2012c50d8ae3SPaolo Bonzini { 2013a955cad8SSean Christopherson if (sp->role.invalid) 2014a955cad8SSean Christopherson return true; 2015a955cad8SSean Christopherson 2016fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 2017de0322f5SSean Christopherson return !is_tdp_mmu_page(sp) && 2018c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 2019c50d8ae3SPaolo Bonzini } 2020c50d8ae3SPaolo Bonzini 2021c50d8ae3SPaolo Bonzini struct mmu_page_path { 2022c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 2023c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 2024c50d8ae3SPaolo Bonzini }; 2025c50d8ae3SPaolo Bonzini 2026c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 2027c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 2028c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 2029c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 2030c50d8ae3SPaolo Bonzini 2031c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 2032c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 2033c50d8ae3SPaolo Bonzini int i) 2034c50d8ae3SPaolo Bonzini { 2035c50d8ae3SPaolo Bonzini int n; 2036c50d8ae3SPaolo Bonzini 2037c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 2038c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 2039c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 2040c50d8ae3SPaolo Bonzini int level = sp->role.level; 2041c50d8ae3SPaolo Bonzini 2042c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 20433bae0459SSean Christopherson if (level == PG_LEVEL_4K) 2044c50d8ae3SPaolo Bonzini break; 2045c50d8ae3SPaolo Bonzini 2046c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2047c50d8ae3SPaolo Bonzini } 2048c50d8ae3SPaolo Bonzini 2049c50d8ae3SPaolo Bonzini return n; 2050c50d8ae3SPaolo Bonzini } 2051c50d8ae3SPaolo Bonzini 2052c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 2053c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 2054c50d8ae3SPaolo Bonzini { 2055c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2056c50d8ae3SPaolo Bonzini int level; 2057c50d8ae3SPaolo Bonzini 2058c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 2059c50d8ae3SPaolo Bonzini return 0; 2060c50d8ae3SPaolo Bonzini 206120ba462dSSean Christopherson WARN_ON_ONCE(pvec->page[0].idx != INVALID_INDEX); 2062c50d8ae3SPaolo Bonzini 2063c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 2064c50d8ae3SPaolo Bonzini level = sp->role.level; 206520ba462dSSean Christopherson WARN_ON_ONCE(level == PG_LEVEL_4K); 2066c50d8ae3SPaolo Bonzini 2067c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2068c50d8ae3SPaolo Bonzini 2069c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 2070c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 2071c50d8ae3SPaolo Bonzini */ 2072c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 2073c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 2074c50d8ae3SPaolo Bonzini } 2075c50d8ae3SPaolo Bonzini 2076c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 2077c50d8ae3SPaolo Bonzini { 2078c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2079c50d8ae3SPaolo Bonzini unsigned int level = 0; 2080c50d8ae3SPaolo Bonzini 2081c50d8ae3SPaolo Bonzini do { 2082c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 2083c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 2084c50d8ae3SPaolo Bonzini if (!sp) 2085c50d8ae3SPaolo Bonzini return; 2086c50d8ae3SPaolo Bonzini 208720ba462dSSean Christopherson WARN_ON_ONCE(idx == INVALID_INDEX); 2088c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 2089c50d8ae3SPaolo Bonzini level++; 2090c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 2091c50d8ae3SPaolo Bonzini } 2092c50d8ae3SPaolo Bonzini 209365855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 209465855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 2095c50d8ae3SPaolo Bonzini { 2096c50d8ae3SPaolo Bonzini int i; 2097c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2098c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2099c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2100c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2101c50d8ae3SPaolo Bonzini bool flush = false; 2102c50d8ae3SPaolo Bonzini 2103c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2104c50d8ae3SPaolo Bonzini bool protected = false; 2105c50d8ae3SPaolo Bonzini 2106c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 2107cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 2108c50d8ae3SPaolo Bonzini 2109c50d8ae3SPaolo Bonzini if (protected) { 21105591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 2111c50d8ae3SPaolo Bonzini flush = false; 2112c50d8ae3SPaolo Bonzini } 2113c50d8ae3SPaolo Bonzini 2114c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2115479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 21168d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 2117c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2118c50d8ae3SPaolo Bonzini } 2119531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2120c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 212165855ed8SLai Jiangshan if (!can_yield) { 212265855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 212365855ed8SLai Jiangshan return -EINTR; 212465855ed8SLai Jiangshan } 212565855ed8SLai Jiangshan 2126531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2127c50d8ae3SPaolo Bonzini flush = false; 2128c50d8ae3SPaolo Bonzini } 2129c50d8ae3SPaolo Bonzini } 2130c50d8ae3SPaolo Bonzini 2131c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 213265855ed8SLai Jiangshan return 0; 2133c50d8ae3SPaolo Bonzini } 2134c50d8ae3SPaolo Bonzini 2135c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2136c50d8ae3SPaolo Bonzini { 2137c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2138c50d8ae3SPaolo Bonzini } 2139c50d8ae3SPaolo Bonzini 2140c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2141c50d8ae3SPaolo Bonzini { 214257354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2143c50d8ae3SPaolo Bonzini } 2144c50d8ae3SPaolo Bonzini 2145cbd858b1SDavid Matlack /* 2146cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2147cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2148cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2149cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2150cbd858b1SDavid Matlack */ 21513cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 21523cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 215394c81364SDavid Matlack gfn_t gfn, 215494c81364SDavid Matlack struct hlist_head *sp_list, 21552e65e842SDavid Matlack union kvm_mmu_page_role role) 2156c50d8ae3SPaolo Bonzini { 2157c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 21588d5678a7SHou Wenlong int ret; 2159c50d8ae3SPaolo Bonzini int collisions = 0; 2160c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2161c50d8ae3SPaolo Bonzini 21623cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2163c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2164c50d8ae3SPaolo Bonzini collisions++; 2165c50d8ae3SPaolo Bonzini continue; 2166c50d8ae3SPaolo Bonzini } 2167c50d8ae3SPaolo Bonzini 2168ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2169ddc16abbSSean Christopherson /* 2170ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2171ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2172ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2173ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2174ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2175ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2176ddc16abbSSean Christopherson * upper-level page will be write-protected. 2177ddc16abbSSean Christopherson */ 21782e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 21793cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2180ddc16abbSSean Christopherson &invalid_list); 2181c50d8ae3SPaolo Bonzini continue; 2182ddc16abbSSean Christopherson } 2183c50d8ae3SPaolo Bonzini 2184bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2185bb924ca6SDavid Matlack if (sp->role.direct) 218694c81364SDavid Matlack goto out; 2187fb58a9c3SSean Christopherson 2188c50d8ae3SPaolo Bonzini if (sp->unsync) { 2189cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2190cbd858b1SDavid Matlack break; 2191cbd858b1SDavid Matlack 219207dc4f35SSean Christopherson /* 2193479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 219407dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 219507dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 219607dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 219707dc4f35SSean Christopherson * overhead of write protection is not incurred until the 219807dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 219907dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 220007dc4f35SSean Christopherson * 220107dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 220207dc4f35SSean Christopherson * in order to rebuild it. 2203c50d8ae3SPaolo Bonzini */ 22048d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 22058d5678a7SHou Wenlong if (ret < 0) 2206c50d8ae3SPaolo Bonzini break; 2207c50d8ae3SPaolo Bonzini 220820ba462dSSean Christopherson WARN_ON_ONCE(!list_empty(&invalid_list)); 22098d5678a7SHou Wenlong if (ret > 0) 22103cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2211c50d8ae3SPaolo Bonzini } 2212c50d8ae3SPaolo Bonzini 2213c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2214fb58a9c3SSean Christopherson 2215c50d8ae3SPaolo Bonzini goto out; 2216c50d8ae3SPaolo Bonzini } 2217c50d8ae3SPaolo Bonzini 221894c81364SDavid Matlack sp = NULL; 22193cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2220c50d8ae3SPaolo Bonzini 222194c81364SDavid Matlack out: 22223cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 222394c81364SDavid Matlack 22243cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 22253cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 222694c81364SDavid Matlack return sp; 222794c81364SDavid Matlack } 222894c81364SDavid Matlack 22292f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 22302f8b1b53SDavid Matlack struct shadow_page_caches { 22312f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 22322f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 22336a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 22342f8b1b53SDavid Matlack }; 22352f8b1b53SDavid Matlack 2236336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 22372f8b1b53SDavid Matlack struct shadow_page_caches *caches, 223894c81364SDavid Matlack gfn_t gfn, 223994c81364SDavid Matlack struct hlist_head *sp_list, 224094c81364SDavid Matlack union kvm_mmu_page_role role) 224194c81364SDavid Matlack { 2242c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2243c306aec8SDavid Matlack 22442f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 22452f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2246c306aec8SDavid Matlack if (!role.direct) 22476a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2248c306aec8SDavid Matlack 2249c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2250c306aec8SDavid Matlack 225155c510e2SSean Christopherson INIT_LIST_HEAD(&sp->possible_nx_huge_page_link); 2252428e9216SSean Christopherson 2253c306aec8SDavid Matlack /* 2254c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2255c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2256c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2257c306aec8SDavid Matlack */ 2258336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2259336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 226043a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2261c50d8ae3SPaolo Bonzini 2262c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2263c50d8ae3SPaolo Bonzini sp->role = role; 2264ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2265be911771SDavid Matlack if (sp_has_gptes(sp)) 2266336081fbSDavid Matlack account_shadowed(kvm, sp); 2267ddc16abbSSean Christopherson 226894c81364SDavid Matlack return sp; 226994c81364SDavid Matlack } 227094c81364SDavid Matlack 2271cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 22723cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 22733cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 22742f8b1b53SDavid Matlack struct shadow_page_caches *caches, 227587654643SDavid Matlack gfn_t gfn, 227694c81364SDavid Matlack union kvm_mmu_page_role role) 227794c81364SDavid Matlack { 227894c81364SDavid Matlack struct hlist_head *sp_list; 227994c81364SDavid Matlack struct kvm_mmu_page *sp; 228094c81364SDavid Matlack bool created = false; 228194c81364SDavid Matlack 22823cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 228394c81364SDavid Matlack 22843cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 228594c81364SDavid Matlack if (!sp) { 228694c81364SDavid Matlack created = true; 22873cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 228894c81364SDavid Matlack } 228994c81364SDavid Matlack 229094c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2291c50d8ae3SPaolo Bonzini return sp; 2292c50d8ae3SPaolo Bonzini } 2293c50d8ae3SPaolo Bonzini 22942f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 22952f8b1b53SDavid Matlack gfn_t gfn, 22962f8b1b53SDavid Matlack union kvm_mmu_page_role role) 22972f8b1b53SDavid Matlack { 22982f8b1b53SDavid Matlack struct shadow_page_caches caches = { 22992f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 23002f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 23016a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 23022f8b1b53SDavid Matlack }; 23032f8b1b53SDavid Matlack 23043cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 23052f8b1b53SDavid Matlack } 23062f8b1b53SDavid Matlack 230739944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 230839944ab9SSean Christopherson unsigned int access) 23092e65e842SDavid Matlack { 23102e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 23112e65e842SDavid Matlack union kvm_mmu_page_role role; 23122e65e842SDavid Matlack 23132e65e842SDavid Matlack role = parent_sp->role; 23142e65e842SDavid Matlack role.level--; 23152e65e842SDavid Matlack role.access = access; 23162e65e842SDavid Matlack role.direct = direct; 23172e65e842SDavid Matlack role.passthrough = 0; 23182e65e842SDavid Matlack 23192e65e842SDavid Matlack /* 23202e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 23212e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 23222e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 23232e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 23242e65e842SDavid Matlack * requires extra bookkeeping in the role. 23252e65e842SDavid Matlack * 23262e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 23272e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 23282e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 23292e65e842SDavid Matlack * the address space each maps. 23302e65e842SDavid Matlack * 23312e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 23322e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 23332e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 23342e65e842SDavid Matlack * 233539944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 233639944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 233739944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 233839944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 233939944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 234039944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 234139944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 234239944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 234339944ab9SSean Christopherson * _least_ significant bit of the PDE index. 23442e65e842SDavid Matlack */ 23452e65e842SDavid Matlack if (role.has_4_byte_gpte) { 23462e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 234779e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 23482e65e842SDavid Matlack } 23492e65e842SDavid Matlack 23502e65e842SDavid Matlack return role; 23512e65e842SDavid Matlack } 23522e65e842SDavid Matlack 23532e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 23542e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 23552e65e842SDavid Matlack bool direct, unsigned int access) 23562e65e842SDavid Matlack { 23572e65e842SDavid Matlack union kvm_mmu_page_role role; 23582e65e842SDavid Matlack 23590cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 23600cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 23610cd8dc73SPaolo Bonzini 23622e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 236387654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 23642e65e842SDavid Matlack } 23652e65e842SDavid Matlack 2366c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2367c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2368c50d8ae3SPaolo Bonzini u64 addr) 2369c50d8ae3SPaolo Bonzini { 2370c50d8ae3SPaolo Bonzini iterator->addr = addr; 2371c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2372a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2373c50d8ae3SPaolo Bonzini 237412ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 23754d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2376347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 237712ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2378c50d8ae3SPaolo Bonzini 2379c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2380c50d8ae3SPaolo Bonzini /* 2381c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2382c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2383c50d8ae3SPaolo Bonzini */ 2384b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2385c50d8ae3SPaolo Bonzini 2386c50d8ae3SPaolo Bonzini iterator->shadow_addr 2387c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 23882ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2389c50d8ae3SPaolo Bonzini --iterator->level; 2390c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2391c50d8ae3SPaolo Bonzini iterator->level = 0; 2392c50d8ae3SPaolo Bonzini } 2393c50d8ae3SPaolo Bonzini } 2394c50d8ae3SPaolo Bonzini 2395c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2396c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2397c50d8ae3SPaolo Bonzini { 2398b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2399c50d8ae3SPaolo Bonzini addr); 2400c50d8ae3SPaolo Bonzini } 2401c50d8ae3SPaolo Bonzini 2402c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2403c50d8ae3SPaolo Bonzini { 24043bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2405c50d8ae3SPaolo Bonzini return false; 2406c50d8ae3SPaolo Bonzini 24072ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2408c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2409c50d8ae3SPaolo Bonzini return true; 2410c50d8ae3SPaolo Bonzini } 2411c50d8ae3SPaolo Bonzini 2412c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2413c50d8ae3SPaolo Bonzini u64 spte) 2414c50d8ae3SPaolo Bonzini { 24153e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2416c50d8ae3SPaolo Bonzini iterator->level = 0; 2417c50d8ae3SPaolo Bonzini return; 2418c50d8ae3SPaolo Bonzini } 2419c50d8ae3SPaolo Bonzini 24202ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2421c50d8ae3SPaolo Bonzini --iterator->level; 2422c50d8ae3SPaolo Bonzini } 2423c50d8ae3SPaolo Bonzini 2424c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2425c50d8ae3SPaolo Bonzini { 2426c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2427c50d8ae3SPaolo Bonzini } 2428c50d8ae3SPaolo Bonzini 24290cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 24300cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 243103787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2432c50d8ae3SPaolo Bonzini { 2433c50d8ae3SPaolo Bonzini u64 spte; 2434c50d8ae3SPaolo Bonzini 2435c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2436c50d8ae3SPaolo Bonzini 24370cd8dc73SPaolo Bonzini /* 24380cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 243903787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 244003787394SPaolo Bonzini * installing sp. 24410cd8dc73SPaolo Bonzini */ 24420cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 244303787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 24440cd8dc73SPaolo Bonzini 2445cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2446c50d8ae3SPaolo Bonzini 2447c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2448c50d8ae3SPaolo Bonzini 24492ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2450c50d8ae3SPaolo Bonzini 2451c4a48868SLai Jiangshan /* 2452c4a48868SLai Jiangshan * The non-direct sub-pagetable must be updated before linking. For 2453c4a48868SLai Jiangshan * L1 sp, the pagetable is updated via kvm_sync_page() in 2454c4a48868SLai Jiangshan * kvm_mmu_find_shadow_page() without write-protecting the gfn, 2455c4a48868SLai Jiangshan * so sp->unsync can be true or false. For higher level non-direct 2456c4a48868SLai Jiangshan * sp, the pagetable is updated/synced via mmu_sync_children() in 2457c4a48868SLai Jiangshan * FNAME(fetch)(), so sp->unsync_children can only be false. 2458c4a48868SLai Jiangshan * WARN_ON_ONCE() if anything happens unexpectedly. 2459c4a48868SLai Jiangshan */ 2460c4a48868SLai Jiangshan if (WARN_ON_ONCE(sp->unsync_children) || sp->unsync) 2461c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2462c50d8ae3SPaolo Bonzini } 2463c50d8ae3SPaolo Bonzini 24642ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 24652ff9039aSDavid Matlack struct kvm_mmu_page *sp) 24662ff9039aSDavid Matlack { 246703787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 24682ff9039aSDavid Matlack } 24692ff9039aSDavid Matlack 2470c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2471c50d8ae3SPaolo Bonzini unsigned direct_access) 2472c50d8ae3SPaolo Bonzini { 2473c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2474c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2475c50d8ae3SPaolo Bonzini 2476c50d8ae3SPaolo Bonzini /* 2477c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2478c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2479c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2480c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2481c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2482c50d8ae3SPaolo Bonzini */ 24835e3edd7eSSean Christopherson child = spte_to_child_sp(*sptep); 2484c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2485c50d8ae3SPaolo Bonzini return; 2486c50d8ae3SPaolo Bonzini 2487069f30c6SMingwei Zhang drop_parent_pte(vcpu->kvm, child, sptep); 24883cdf9374SHou Wenlong kvm_flush_remote_tlbs_sptep(vcpu->kvm, sptep); 2489c50d8ae3SPaolo Bonzini } 2490c50d8ae3SPaolo Bonzini } 2491c50d8ae3SPaolo Bonzini 24922de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 24932de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 24942de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2495c50d8ae3SPaolo Bonzini { 2496c50d8ae3SPaolo Bonzini u64 pte; 2497c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2498c50d8ae3SPaolo Bonzini 2499c50d8ae3SPaolo Bonzini pte = *spte; 2500c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2501c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2502c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2503c50d8ae3SPaolo Bonzini } else { 25045e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2505069f30c6SMingwei Zhang drop_parent_pte(kvm, child, spte); 25062de4085cSBen Gardon 25072de4085cSBen Gardon /* 25082de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 25092de4085cSBen Gardon * unlikely to be used again in the near future. This 25102de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 25112de4085cSBen Gardon */ 25122de4085cSBen Gardon if (tdp_enabled && invalid_list && 25132de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 25142de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 25152de4085cSBen Gardon invalid_list); 2516c50d8ae3SPaolo Bonzini } 2517ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2518c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2519ace569e0SSean Christopherson } 25202de4085cSBen Gardon return 0; 2521c50d8ae3SPaolo Bonzini } 2522c50d8ae3SPaolo Bonzini 25232de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 25242de4085cSBen Gardon struct kvm_mmu_page *sp, 25252de4085cSBen Gardon struct list_head *invalid_list) 2526c50d8ae3SPaolo Bonzini { 25272de4085cSBen Gardon int zapped = 0; 2528c50d8ae3SPaolo Bonzini unsigned i; 2529c50d8ae3SPaolo Bonzini 25302ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 25312de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 25322de4085cSBen Gardon 25332de4085cSBen Gardon return zapped; 2534c50d8ae3SPaolo Bonzini } 2535c50d8ae3SPaolo Bonzini 2536069f30c6SMingwei Zhang static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) 2537c50d8ae3SPaolo Bonzini { 2538c50d8ae3SPaolo Bonzini u64 *sptep; 2539c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2540c50d8ae3SPaolo Bonzini 2541c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2542069f30c6SMingwei Zhang drop_parent_pte(kvm, sp, sptep); 2543c50d8ae3SPaolo Bonzini } 2544c50d8ae3SPaolo Bonzini 2545c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2546c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2547c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2548c50d8ae3SPaolo Bonzini { 2549c50d8ae3SPaolo Bonzini int i, zapped = 0; 2550c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2551c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2552c50d8ae3SPaolo Bonzini 25533bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2554c50d8ae3SPaolo Bonzini return 0; 2555c50d8ae3SPaolo Bonzini 2556c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2557c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2558c50d8ae3SPaolo Bonzini 2559c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2560c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2561c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2562c50d8ae3SPaolo Bonzini zapped++; 2563c50d8ae3SPaolo Bonzini } 2564c50d8ae3SPaolo Bonzini } 2565c50d8ae3SPaolo Bonzini 2566c50d8ae3SPaolo Bonzini return zapped; 2567c50d8ae3SPaolo Bonzini } 2568c50d8ae3SPaolo Bonzini 2569c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2570c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2571c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2572c50d8ae3SPaolo Bonzini int *nr_zapped) 2573c50d8ae3SPaolo Bonzini { 2574527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2575c50d8ae3SPaolo Bonzini 257647b0c2e4SKazuki Takiguchi lockdep_assert_held_write(&kvm->mmu_lock); 2577c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2578c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2579c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 25802de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 2581069f30c6SMingwei Zhang kvm_mmu_unlink_parents(kvm, sp); 2582c50d8ae3SPaolo Bonzini 2583c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2584c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2585c50d8ae3SPaolo Bonzini 2586767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2587c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2588c50d8ae3SPaolo Bonzini 2589c50d8ae3SPaolo Bonzini if (sp->unsync) 2590c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2591c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2592c50d8ae3SPaolo Bonzini /* Count self */ 2593c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2594f95eec9bSSean Christopherson 2595f95eec9bSSean Christopherson /* 2596f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2597f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2598f95eec9bSSean Christopherson * !sp->root_count. 2599f95eec9bSSean Christopherson */ 2600f95eec9bSSean Christopherson if (sp->role.invalid) 2601f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2602f95eec9bSSean Christopherson else 2603c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 260443a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2605c50d8ae3SPaolo Bonzini } else { 2606f95eec9bSSean Christopherson /* 2607f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2608f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2609f95eec9bSSean Christopherson */ 2610f95eec9bSSean Christopherson list_del(&sp->link); 2611c50d8ae3SPaolo Bonzini 2612c50d8ae3SPaolo Bonzini /* 2613c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2614c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2615c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2616c50d8ae3SPaolo Bonzini */ 2617527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2618c50d8ae3SPaolo Bonzini } 2619c50d8ae3SPaolo Bonzini 262055c510e2SSean Christopherson if (sp->nx_huge_page_disallowed) 262155c510e2SSean Christopherson unaccount_nx_huge_page(kvm, sp); 2622c50d8ae3SPaolo Bonzini 2623c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2624527d5cd7SSean Christopherson 2625527d5cd7SSean Christopherson /* 2626527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2627527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2628527d5cd7SSean Christopherson */ 2629527d5cd7SSean Christopherson if (zapped_root) 2630527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2631c50d8ae3SPaolo Bonzini return list_unstable; 2632c50d8ae3SPaolo Bonzini } 2633c50d8ae3SPaolo Bonzini 2634c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2635c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2636c50d8ae3SPaolo Bonzini { 2637c50d8ae3SPaolo Bonzini int nr_zapped; 2638c50d8ae3SPaolo Bonzini 2639c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2640c50d8ae3SPaolo Bonzini return nr_zapped; 2641c50d8ae3SPaolo Bonzini } 2642c50d8ae3SPaolo Bonzini 2643c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2644c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2645c50d8ae3SPaolo Bonzini { 2646c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2647c50d8ae3SPaolo Bonzini 2648c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2649c50d8ae3SPaolo Bonzini return; 2650c50d8ae3SPaolo Bonzini 2651c50d8ae3SPaolo Bonzini /* 2652c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2653c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2654c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2655c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2656c50d8ae3SPaolo Bonzini * 2657c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2658c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2659c50d8ae3SPaolo Bonzini */ 2660c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2661c50d8ae3SPaolo Bonzini 2662c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 266320ba462dSSean Christopherson WARN_ON_ONCE(!sp->role.invalid || sp->root_count); 266487654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2665c50d8ae3SPaolo Bonzini } 2666c50d8ae3SPaolo Bonzini } 2667c50d8ae3SPaolo Bonzini 26686b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 26696b82ef2cSSean Christopherson unsigned long nr_to_zap) 2670c50d8ae3SPaolo Bonzini { 26716b82ef2cSSean Christopherson unsigned long total_zapped = 0; 26726b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2673ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 26746b82ef2cSSean Christopherson bool unstable; 26756b82ef2cSSean Christopherson int nr_zapped; 2676c50d8ae3SPaolo Bonzini 2677c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2678ba7888ddSSean Christopherson return 0; 2679c50d8ae3SPaolo Bonzini 26806b82ef2cSSean Christopherson restart: 26818fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 26826b82ef2cSSean Christopherson /* 26836b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 26846b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 26856b82ef2cSSean Christopherson */ 26866b82ef2cSSean Christopherson if (sp->root_count) 26876b82ef2cSSean Christopherson continue; 26886b82ef2cSSean Christopherson 26896b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 26906b82ef2cSSean Christopherson &nr_zapped); 26916b82ef2cSSean Christopherson total_zapped += nr_zapped; 26926b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2693ba7888ddSSean Christopherson break; 2694ba7888ddSSean Christopherson 26956b82ef2cSSean Christopherson if (unstable) 26966b82ef2cSSean Christopherson goto restart; 2697ba7888ddSSean Christopherson } 26986b82ef2cSSean Christopherson 26996b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 27006b82ef2cSSean Christopherson 27016b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 27026b82ef2cSSean Christopherson return total_zapped; 27036b82ef2cSSean Christopherson } 27046b82ef2cSSean Christopherson 2705afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2706afe8d7e6SSean Christopherson { 2707afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2708afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2709afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2710afe8d7e6SSean Christopherson 2711afe8d7e6SSean Christopherson return 0; 2712c50d8ae3SPaolo Bonzini } 2713c50d8ae3SPaolo Bonzini 2714ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2715ba7888ddSSean Christopherson { 27166b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2717ba7888ddSSean Christopherson 27186b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2719ba7888ddSSean Christopherson return 0; 2720ba7888ddSSean Christopherson 27216b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2722ba7888ddSSean Christopherson 27236e6ec584SSean Christopherson /* 27246e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 27256e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 27266e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 27276e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2728c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 27296e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 27306e6ec584SSean Christopherson * page fault paths. 27316e6ec584SSean Christopherson */ 2732ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2733ba7888ddSSean Christopherson return -ENOSPC; 2734ba7888ddSSean Christopherson return 0; 2735ba7888ddSSean Christopherson } 2736ba7888ddSSean Christopherson 2737c50d8ae3SPaolo Bonzini /* 2738c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2739c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2740c50d8ae3SPaolo Bonzini */ 2741c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2742c50d8ae3SPaolo Bonzini { 2743531810caSBen Gardon write_lock(&kvm->mmu_lock); 2744c50d8ae3SPaolo Bonzini 2745c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 27466b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 27476b82ef2cSSean Christopherson goal_nr_mmu_pages); 2748c50d8ae3SPaolo Bonzini 2749c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2750c50d8ae3SPaolo Bonzini } 2751c50d8ae3SPaolo Bonzini 2752c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2753c50d8ae3SPaolo Bonzini 2754531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2755c50d8ae3SPaolo Bonzini } 2756c50d8ae3SPaolo Bonzini 2757c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2758c50d8ae3SPaolo Bonzini { 2759c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2760c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2761c50d8ae3SPaolo Bonzini int r; 2762c50d8ae3SPaolo Bonzini 2763c50d8ae3SPaolo Bonzini r = 0; 2764531810caSBen Gardon write_lock(&kvm->mmu_lock); 2765767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2766c50d8ae3SPaolo Bonzini r = 1; 2767c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2768c50d8ae3SPaolo Bonzini } 2769c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2770531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2771c50d8ae3SPaolo Bonzini 2772c50d8ae3SPaolo Bonzini return r; 2773c50d8ae3SPaolo Bonzini } 277496ad91aeSSean Christopherson 277596ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 277696ad91aeSSean Christopherson { 277796ad91aeSSean Christopherson gpa_t gpa; 277896ad91aeSSean Christopherson int r; 277996ad91aeSSean Christopherson 2780347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 278196ad91aeSSean Christopherson return 0; 278296ad91aeSSean Christopherson 278396ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 278496ad91aeSSean Christopherson 278596ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 278696ad91aeSSean Christopherson 278796ad91aeSSean Christopherson return r; 278896ad91aeSSean Christopherson } 2789c50d8ae3SPaolo Bonzini 27904d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2791c50d8ae3SPaolo Bonzini { 2792c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 27934d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2794c50d8ae3SPaolo Bonzini sp->unsync = 1; 2795c50d8ae3SPaolo Bonzini 2796c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2797c50d8ae3SPaolo Bonzini } 2798c50d8ae3SPaolo Bonzini 27990337f585SSean Christopherson /* 28000337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 28010337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 28020337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 28030337f585SSean Christopherson * be write-protected. 28040337f585SSean Christopherson */ 28058283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 28062839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2807c50d8ae3SPaolo Bonzini { 2808c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2809ce25681dSSean Christopherson bool locked = false; 2810c50d8ae3SPaolo Bonzini 28110337f585SSean Christopherson /* 28120337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 28130337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 28140337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 28150337f585SSean Christopherson */ 28167b574863SSean Christopherson if (kvm_gfn_is_write_tracked(kvm, slot, gfn)) 28170337f585SSean Christopherson return -EPERM; 2818c50d8ae3SPaolo Bonzini 28190337f585SSean Christopherson /* 28200337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 28210337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 28220337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 28230337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 28240337f585SSean Christopherson */ 2825767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2826c50d8ae3SPaolo Bonzini if (!can_unsync) 28270337f585SSean Christopherson return -EPERM; 2828c50d8ae3SPaolo Bonzini 2829c50d8ae3SPaolo Bonzini if (sp->unsync) 2830c50d8ae3SPaolo Bonzini continue; 2831c50d8ae3SPaolo Bonzini 28322839180cSPaolo Bonzini if (prefetch) 2833f1c4a88cSLai Jiangshan return -EEXIST; 2834f1c4a88cSLai Jiangshan 2835ce25681dSSean Christopherson /* 2836ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2837ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2838ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2839ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2840ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2841ce25681dSSean Christopherson */ 2842ce25681dSSean Christopherson if (!locked) { 2843ce25681dSSean Christopherson locked = true; 28444d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2845ce25681dSSean Christopherson 2846ce25681dSSean Christopherson /* 2847ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2848ce25681dSSean Christopherson * may have since marked the page unsync. A false 2849e59f75deSPaolo Bonzini * negative on the unprotected check above is not 2850ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2851e59f75deSPaolo Bonzini * for write, i.e. unsync cannot transition from 1->0 2852ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2853ce25681dSSean Christopherson */ 2854ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2855ce25681dSSean Christopherson continue; 2856ce25681dSSean Christopherson } 2857ce25681dSSean Christopherson 285820ba462dSSean Christopherson WARN_ON_ONCE(sp->role.level != PG_LEVEL_4K); 28594d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2860c50d8ae3SPaolo Bonzini } 2861ce25681dSSean Christopherson if (locked) 28624d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2863c50d8ae3SPaolo Bonzini 2864c50d8ae3SPaolo Bonzini /* 2865c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2866c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2867c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2868c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2869c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2870c50d8ae3SPaolo Bonzini * following could happen: 2871c50d8ae3SPaolo Bonzini * 2872c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2873c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2874c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2875c50d8ae3SPaolo Bonzini * to be writable 2876c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2877c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2878c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2879c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2880c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2881c50d8ae3SPaolo Bonzini * fault. 2882c50d8ae3SPaolo Bonzini * 2883c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2884c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2885c50d8ae3SPaolo Bonzini * 28860337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 28870337f585SSean Christopherson * false and skips the page. 2888c50d8ae3SPaolo Bonzini * 2889c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2890c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2891c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2892c50d8ae3SPaolo Bonzini * gets used. 2893c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2894c50d8ae3SPaolo Bonzini * as unsync 2895c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2896c50d8ae3SPaolo Bonzini * 2897c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2898264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2899264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2900c50d8ae3SPaolo Bonzini */ 2901c50d8ae3SPaolo Bonzini smp_wmb(); 2902c50d8ae3SPaolo Bonzini 29030337f585SSean Christopherson return 0; 2904c50d8ae3SPaolo Bonzini } 2905c50d8ae3SPaolo Bonzini 29068a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 29078a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2908a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2909799a4190SBen Gardon { 2910d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2911eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2912c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2913c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2914c50d8ae3SPaolo Bonzini bool flush = false; 2915ad67e480SPaolo Bonzini bool wrprot; 2916d786c778SPaolo Bonzini u64 spte; 2917c50d8ae3SPaolo Bonzini 2918a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2919a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 29202839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2921a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2922c50d8ae3SPaolo Bonzini 2923a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 29241075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2925a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2926a54aa15cSSean Christopherson return RET_PF_EMULATE; 2927a54aa15cSSean Christopherson } 2928a54aa15cSSean Christopherson 2929c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2930c50d8ae3SPaolo Bonzini /* 2931c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2932c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2933c50d8ae3SPaolo Bonzini */ 29343bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2935c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2936c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2937c50d8ae3SPaolo Bonzini 29385e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2939069f30c6SMingwei Zhang drop_parent_pte(vcpu->kvm, child, sptep); 2940c50d8ae3SPaolo Bonzini flush = true; 2941c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2942c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2943c50d8ae3SPaolo Bonzini flush = true; 2944c50d8ae3SPaolo Bonzini } else 2945c50d8ae3SPaolo Bonzini was_rmapped = 1; 2946c50d8ae3SPaolo Bonzini } 2947c50d8ae3SPaolo Bonzini 29482839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 29497158bee4SPaolo Bonzini true, host_writable, &spte); 2950d786c778SPaolo Bonzini 2951d786c778SPaolo Bonzini if (*sptep == spte) { 2952d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2953d786c778SPaolo Bonzini } else { 2954d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 29555959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2956c50d8ae3SPaolo Bonzini } 2957c50d8ae3SPaolo Bonzini 2958ad67e480SPaolo Bonzini if (wrprot) { 2959c50d8ae3SPaolo Bonzini if (write_fault) 2960c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2961c50d8ae3SPaolo Bonzini } 2962c50d8ae3SPaolo Bonzini 2963d786c778SPaolo Bonzini if (flush) 29644ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(vcpu->kvm, gfn, level); 2965c50d8ae3SPaolo Bonzini 2966c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2967d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 29686a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 29696a97575dSDavid Matlack } else { 29706a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 297179e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2972c50d8ae3SPaolo Bonzini } 2973c50d8ae3SPaolo Bonzini 2974c50d8ae3SPaolo Bonzini return ret; 2975c50d8ae3SPaolo Bonzini } 2976c50d8ae3SPaolo Bonzini 2977c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2978c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2979c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2980c50d8ae3SPaolo Bonzini { 2981c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2982c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 29830a2b64c5SBen Gardon unsigned int access = sp->role.access; 2984c50d8ae3SPaolo Bonzini int i, ret; 2985c50d8ae3SPaolo Bonzini gfn_t gfn; 2986c50d8ae3SPaolo Bonzini 298779e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 2988c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2989c50d8ae3SPaolo Bonzini if (!slot) 2990c50d8ae3SPaolo Bonzini return -1; 2991c50d8ae3SPaolo Bonzini 2992c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2993c50d8ae3SPaolo Bonzini if (ret <= 0) 2994c50d8ae3SPaolo Bonzini return -1; 2995c50d8ae3SPaolo Bonzini 2996c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 29978a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2998a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2999c50d8ae3SPaolo Bonzini put_page(pages[i]); 3000c50d8ae3SPaolo Bonzini } 3001c50d8ae3SPaolo Bonzini 3002c50d8ae3SPaolo Bonzini return 0; 3003c50d8ae3SPaolo Bonzini } 3004c50d8ae3SPaolo Bonzini 3005c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 3006c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 3007c50d8ae3SPaolo Bonzini { 3008c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 3009c50d8ae3SPaolo Bonzini int i; 3010c50d8ae3SPaolo Bonzini 301120ba462dSSean Christopherson WARN_ON_ONCE(!sp->role.direct); 3012c50d8ae3SPaolo Bonzini 301379e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 3014c50d8ae3SPaolo Bonzini spte = sp->spt + i; 3015c50d8ae3SPaolo Bonzini 3016c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 3017c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 3018c50d8ae3SPaolo Bonzini if (!start) 3019c50d8ae3SPaolo Bonzini continue; 3020c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 3021c6cecc4bSSean Christopherson return; 3022c50d8ae3SPaolo Bonzini start = NULL; 3023c50d8ae3SPaolo Bonzini } else if (!start) 3024c50d8ae3SPaolo Bonzini start = spte; 3025c50d8ae3SPaolo Bonzini } 3026c6cecc4bSSean Christopherson if (start) 3027c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 3028c50d8ae3SPaolo Bonzini } 3029c50d8ae3SPaolo Bonzini 3030c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 3031c50d8ae3SPaolo Bonzini { 3032c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3033c50d8ae3SPaolo Bonzini 303457354682SSean Christopherson sp = sptep_to_sp(sptep); 3035c50d8ae3SPaolo Bonzini 3036c50d8ae3SPaolo Bonzini /* 3037c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 3038c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 3039c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 3040c50d8ae3SPaolo Bonzini */ 3041c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 3042c50d8ae3SPaolo Bonzini return; 3043c50d8ae3SPaolo Bonzini 30443bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 3045c50d8ae3SPaolo Bonzini return; 3046c50d8ae3SPaolo Bonzini 30474a42d848SDavid Stevens /* 30484a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 30494a42d848SDavid Stevens * accidentally prefetching those addresses. 30504a42d848SDavid Stevens */ 305120ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 30524a42d848SDavid Stevens return; 30534a42d848SDavid Stevens 3054c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 3055c50d8ae3SPaolo Bonzini } 3056c50d8ae3SPaolo Bonzini 305765e3b446SSean Christopherson /* 305865e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 305965e3b446SSean Christopherson * 306065e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 306165e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 306265e3b446SSean Christopherson * 306365e3b446SSean Christopherson * There are several ways to safely use this helper: 306465e3b446SSean Christopherson * 30658569992dSChao Peng * - Check mmu_invalidate_retry_gfn() after grabbing the mapping level, before 306665e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 306765e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 306865e3b446SSean Christopherson * 306965e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 307065e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 307165e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 307265e3b446SSean Christopherson * 307365e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 307465e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 307565e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 307665e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 307765e3b446SSean Christopherson * 307865e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 307965e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 308065e3b446SSean Christopherson * race with the primary MMU occurs. 308165e3b446SSean Christopherson */ 3082a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 30838ca6f063SBen Gardon const struct kvm_memory_slot *slot) 3084db543216SSean Christopherson { 3085284dc493SSean Christopherson int level = PG_LEVEL_4K; 3086db543216SSean Christopherson unsigned long hva; 308744187235SMingwei Zhang unsigned long flags; 308844187235SMingwei Zhang pgd_t pgd; 308944187235SMingwei Zhang p4d_t p4d; 309044187235SMingwei Zhang pud_t pud; 309144187235SMingwei Zhang pmd_t pmd; 3092db543216SSean Christopherson 30935d49f08cSSean Christopherson /* 3094293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 3095293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 3096293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 3097293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 3098293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 3099293e306eSSean Christopherson * read-only memslot. 3100293e306eSSean Christopherson */ 3101db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 3102db543216SSean Christopherson 310344187235SMingwei Zhang /* 310465e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 310565e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 310665e3b446SSean Christopherson * the original page table. 310744187235SMingwei Zhang */ 310844187235SMingwei Zhang local_irq_save(flags); 3109db543216SSean Christopherson 311065e3b446SSean Christopherson /* 311165e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 311265e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 3113e72c7c2bSPeter Xu * walk into the weeks, e.g. p*d_leaf() returns false (sees the old 311465e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 311565e3b446SSean Christopherson * of the old page table (sees the new value). 311665e3b446SSean Christopherson */ 311744187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 311844187235SMingwei Zhang if (pgd_none(pgd)) 311944187235SMingwei Zhang goto out; 312044187235SMingwei Zhang 312144187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 312244187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 312344187235SMingwei Zhang goto out; 312444187235SMingwei Zhang 312544187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 312644187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 312744187235SMingwei Zhang goto out; 312844187235SMingwei Zhang 31290a845e0fSPeter Xu if (pud_leaf(pud)) { 313044187235SMingwei Zhang level = PG_LEVEL_1G; 313144187235SMingwei Zhang goto out; 313244187235SMingwei Zhang } 313344187235SMingwei Zhang 313444187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 313544187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 313644187235SMingwei Zhang goto out; 313744187235SMingwei Zhang 31382f709f7bSPeter Xu if (pmd_leaf(pmd)) 313944187235SMingwei Zhang level = PG_LEVEL_2M; 314044187235SMingwei Zhang 314144187235SMingwei Zhang out: 314244187235SMingwei Zhang local_irq_restore(flags); 3143db543216SSean Christopherson return level; 3144db543216SSean Christopherson } 3145db543216SSean Christopherson 31468dd2eee9SChao Peng static int __kvm_mmu_max_mapping_level(struct kvm *kvm, 31478dd2eee9SChao Peng const struct kvm_memory_slot *slot, 31488dd2eee9SChao Peng gfn_t gfn, int max_level, bool is_private) 31491b6d9d9eSSean Christopherson { 31501b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3151ec607a56SPaolo Bonzini int host_level; 31521b6d9d9eSSean Christopherson 31531b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 31541b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 31551b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 31561b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 31571b6d9d9eSSean Christopherson break; 31581b6d9d9eSSean Christopherson } 31591b6d9d9eSSean Christopherson 31608dd2eee9SChao Peng if (is_private) 31618dd2eee9SChao Peng return max_level; 31628dd2eee9SChao Peng 31631b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 31641b6d9d9eSSean Christopherson return PG_LEVEL_4K; 31651b6d9d9eSSean Christopherson 3166a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3167ec607a56SPaolo Bonzini return min(host_level, max_level); 31681b6d9d9eSSean Christopherson } 31691b6d9d9eSSean Christopherson 31708dd2eee9SChao Peng int kvm_mmu_max_mapping_level(struct kvm *kvm, 31718dd2eee9SChao Peng const struct kvm_memory_slot *slot, gfn_t gfn, 31728dd2eee9SChao Peng int max_level) 31738dd2eee9SChao Peng { 31748dd2eee9SChao Peng bool is_private = kvm_slot_can_be_private(slot) && 31758dd2eee9SChao Peng kvm_mem_is_private(kvm, gfn); 31768dd2eee9SChao Peng 31778dd2eee9SChao Peng return __kvm_mmu_max_mapping_level(kvm, slot, gfn, max_level, is_private); 31788dd2eee9SChao Peng } 31798dd2eee9SChao Peng 318073a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 31810885904dSSean Christopherson { 3182e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 318317eff019SSean Christopherson kvm_pfn_t mask; 31840885904dSSean Christopherson 318573a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 31863cf06612SSean Christopherson 318773a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 318873a3c659SPaolo Bonzini return; 318917eff019SSean Christopherson 31905d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 319173a3c659SPaolo Bonzini return; 319217eff019SSean Christopherson 3193e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 319473a3c659SPaolo Bonzini return; 3195293e306eSSean Christopherson 31963cf06612SSean Christopherson /* 31973cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 31983cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 31993cf06612SSean Christopherson */ 32008dd2eee9SChao Peng fault->req_level = __kvm_mmu_max_mapping_level(vcpu->kvm, slot, 32018dd2eee9SChao Peng fault->gfn, fault->max_level, 32028dd2eee9SChao Peng fault->is_private); 320373a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 320473a3c659SPaolo Bonzini return; 32054cd071d1SSean Christopherson 32060885904dSSean Christopherson /* 320720ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 32084cd071d1SSean Christopherson * the pmd can't be split from under us. 32090885904dSSean Christopherson */ 321073a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 321173a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 321273a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 321373a3c659SPaolo Bonzini fault->pfn &= ~mask; 32140885904dSSean Christopherson } 32150885904dSSean Christopherson 3216536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3217c50d8ae3SPaolo Bonzini { 3218536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3219536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3220c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 322176901e56SMingwei Zhang !is_large_pte(spte) && 322276901e56SMingwei Zhang spte_to_child_sp(spte)->nx_huge_page_disallowed) { 3223c50d8ae3SPaolo Bonzini /* 32246c882ef4SDavid Matlack * A small SPTE exists for this pfn, but FNAME(fetch), 32256c882ef4SDavid Matlack * direct_map(), or kvm_tdp_mmu_map() would like to create a 32266c882ef4SDavid Matlack * large PTE instead: just force them to go down another level, 32276c882ef4SDavid Matlack * patching back for them into pfn the next 9 bits of the 32286c882ef4SDavid Matlack * address. 3229c50d8ae3SPaolo Bonzini */ 3230536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3231536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3232536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3233536f0e6aSPaolo Bonzini fault->goal_level--; 3234c50d8ae3SPaolo Bonzini } 3235c50d8ae3SPaolo Bonzini } 3236c50d8ae3SPaolo Bonzini 32376c882ef4SDavid Matlack static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3238c50d8ae3SPaolo Bonzini { 3239c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3240c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 324173a3c659SPaolo Bonzini int ret; 324243b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3243c50d8ae3SPaolo Bonzini 324473a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 32454cd071d1SSean Christopherson 3246f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 324743b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3248c50d8ae3SPaolo Bonzini /* 3249c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3250c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3251c50d8ae3SPaolo Bonzini */ 325273a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3253536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3254c50d8ae3SPaolo Bonzini 3255c667a3baSHou Wenlong base_gfn = gfn_round_for_level(fault->gfn, it.level); 325673a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3257c50d8ae3SPaolo Bonzini break; 3258c50d8ae3SPaolo Bonzini 32592e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 32600cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 32610cd8dc73SPaolo Bonzini continue; 3262c50d8ae3SPaolo Bonzini 3263c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 3264b5b0977fSSean Christopherson if (fault->huge_page_disallowed) 326555c510e2SSean Christopherson account_nx_huge_page(vcpu->kvm, sp, 3266428e9216SSean Christopherson fault->req_level >= it.level); 3267c50d8ae3SPaolo Bonzini } 3268c50d8ae3SPaolo Bonzini 3269b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3270b1a429fbSSean Christopherson return -EFAULT; 3271b1a429fbSSean Christopherson 32728a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3273a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 327412703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 327512703759SSean Christopherson return ret; 327612703759SSean Christopherson 3277c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3278c50d8ae3SPaolo Bonzini return ret; 3279c50d8ae3SPaolo Bonzini } 3280c50d8ae3SPaolo Bonzini 3281cd08d178SDavid Matlack static void kvm_send_hwpoison_signal(struct kvm_memory_slot *slot, gfn_t gfn) 3282c50d8ae3SPaolo Bonzini { 3283cd08d178SDavid Matlack unsigned long hva = gfn_to_hva_memslot(slot, gfn); 3284cd08d178SDavid Matlack 3285cd08d178SDavid Matlack send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); 3286c50d8ae3SPaolo Bonzini } 3287c50d8ae3SPaolo Bonzini 3288cd08d178SDavid Matlack static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3289c50d8ae3SPaolo Bonzini { 3290cd08d178SDavid Matlack if (is_sigpending_pfn(fault->pfn)) { 329176657687SPeter Xu kvm_handle_signal_exit(vcpu); 329276657687SPeter Xu return -EINTR; 329376657687SPeter Xu } 329476657687SPeter Xu 3295c50d8ae3SPaolo Bonzini /* 3296c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3297c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3298c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3299c50d8ae3SPaolo Bonzini */ 3300cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_RO_FAULT) 3301c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3302c50d8ae3SPaolo Bonzini 3303cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_HWPOISON) { 3304cd08d178SDavid Matlack kvm_send_hwpoison_signal(fault->slot, fault->gfn); 3305c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3306c50d8ae3SPaolo Bonzini } 3307c50d8ae3SPaolo Bonzini 3308c50d8ae3SPaolo Bonzini return -EFAULT; 3309c50d8ae3SPaolo Bonzini } 3310c50d8ae3SPaolo Bonzini 3311354c908cSDavid Matlack static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu, 3312354c908cSDavid Matlack struct kvm_page_fault *fault, 33135276c616SSean Christopherson unsigned int access) 3314c50d8ae3SPaolo Bonzini { 33153a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 33163a13f4feSPaolo Bonzini 33173a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3318c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 3319354c908cSDavid Matlack 332030ab5901SSean Christopherson /* 332130ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 332230ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 3323354c908cSDavid Matlack * MMIO SPTE will just be an expensive nop. 332430ab5901SSean Christopherson */ 3325354c908cSDavid Matlack if (unlikely(!enable_mmio_caching)) 33265276c616SSean Christopherson return RET_PF_EMULATE; 3327354c908cSDavid Matlack 3328354c908cSDavid Matlack /* 3329354c908cSDavid Matlack * Do not create an MMIO SPTE for a gfn greater than host.MAXPHYADDR, 3330354c908cSDavid Matlack * any guest that generates such gfns is running nested and is being 3331354c908cSDavid Matlack * tricked by L0 userspace (you can observe gfn > L1.MAXPHYADDR if and 3332354c908cSDavid Matlack * only if L1's MAXPHYADDR is inaccurate with respect to the 3333354c908cSDavid Matlack * hardware's). 3334354c908cSDavid Matlack */ 3335354c908cSDavid Matlack if (unlikely(fault->gfn > kvm_mmu_max_gfn())) 3336354c908cSDavid Matlack return RET_PF_EMULATE; 3337c50d8ae3SPaolo Bonzini 33385276c616SSean Christopherson return RET_PF_CONTINUE; 3339c50d8ae3SPaolo Bonzini } 3340c50d8ae3SPaolo Bonzini 33413c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3342c50d8ae3SPaolo Bonzini { 3343c50d8ae3SPaolo Bonzini /* 33445c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 33455c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 33465c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 33475c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3348c50d8ae3SPaolo Bonzini */ 33493c8ad5a6SPaolo Bonzini if (fault->rsvd) 3350c50d8ae3SPaolo Bonzini return false; 3351c50d8ae3SPaolo Bonzini 3352c50d8ae3SPaolo Bonzini /* 3353c50d8ae3SPaolo Bonzini * #PF can be fast if: 3354c50d8ae3SPaolo Bonzini * 335554275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 335654275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 335754275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 335854275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 335954275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 336054275f74SSean Christopherson * mechanism only supports direct MMUs. 336154275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 336254275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 336354275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 336454275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 336554275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3366c50d8ae3SPaolo Bonzini */ 33675c64aba5SSean Christopherson if (!fault->present) 33685c64aba5SSean Christopherson return !kvm_ad_enabled(); 33695c64aba5SSean Christopherson 33705c64aba5SSean Christopherson /* 33715c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 33725c64aba5SSean Christopherson * the "exec" flag. 33735c64aba5SSean Christopherson */ 33745c64aba5SSean Christopherson return fault->write; 3375c50d8ae3SPaolo Bonzini } 3376c50d8ae3SPaolo Bonzini 3377c50d8ae3SPaolo Bonzini /* 3378c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3379c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3380c50d8ae3SPaolo Bonzini */ 3381f3d90f90SSean Christopherson static bool fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, 3382f3d90f90SSean Christopherson struct kvm_page_fault *fault, 3383c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3384c50d8ae3SPaolo Bonzini { 3385c50d8ae3SPaolo Bonzini /* 3386c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3387c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3388c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3389c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3390c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3391c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3392c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3393c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3394c50d8ae3SPaolo Bonzini * 3395c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3396c50d8ae3SPaolo Bonzini */ 33972db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3398c50d8ae3SPaolo Bonzini return false; 3399c50d8ae3SPaolo Bonzini 3400e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3401e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3402c50d8ae3SPaolo Bonzini 3403c50d8ae3SPaolo Bonzini return true; 3404c50d8ae3SPaolo Bonzini } 3405c50d8ae3SPaolo Bonzini 34063c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3407c50d8ae3SPaolo Bonzini { 34083c8ad5a6SPaolo Bonzini if (fault->exec) 3409c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3410c50d8ae3SPaolo Bonzini 34113c8ad5a6SPaolo Bonzini if (fault->write) 3412c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3413c50d8ae3SPaolo Bonzini 3414c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3415c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3416c50d8ae3SPaolo Bonzini } 3417c50d8ae3SPaolo Bonzini 3418c50d8ae3SPaolo Bonzini /* 34196e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 34206e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 34216e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 34226e8eb206SDavid Matlack * 34236e8eb206SDavid Matlack * Contract: 34246e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 34256e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 34266e8eb206SDavid Matlack */ 34276e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 34286e8eb206SDavid Matlack { 34296e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 34306e8eb206SDavid Matlack u64 old_spte; 34316e8eb206SDavid Matlack u64 *sptep = NULL; 34326e8eb206SDavid Matlack 34336e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 34346e8eb206SDavid Matlack sptep = iterator.sptep; 34356e8eb206SDavid Matlack *spte = old_spte; 34366e8eb206SDavid Matlack } 34376e8eb206SDavid Matlack 34386e8eb206SDavid Matlack return sptep; 34396e8eb206SDavid Matlack } 34406e8eb206SDavid Matlack 34416e8eb206SDavid Matlack /* 3442c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3443c50d8ae3SPaolo Bonzini */ 34443c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3445c50d8ae3SPaolo Bonzini { 3446c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3447c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 34481de9992fSLi zeming u64 spte; 34491de9992fSLi zeming u64 *sptep; 3450c50d8ae3SPaolo Bonzini uint retry_count = 0; 3451c50d8ae3SPaolo Bonzini 34523c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3453c4371c2aSSean Christopherson return ret; 3454c50d8ae3SPaolo Bonzini 3455c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3456c50d8ae3SPaolo Bonzini 3457c50d8ae3SPaolo Bonzini do { 3458c50d8ae3SPaolo Bonzini u64 new_spte; 3459c50d8ae3SPaolo Bonzini 3460dfe0ecc6SSean Christopherson if (tdp_mmu_enabled) 34613c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 34626e8eb206SDavid Matlack else 34633c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3464c50d8ae3SPaolo Bonzini 34651de9992fSLi zeming /* 34661de9992fSLi zeming * It's entirely possible for the mapping to have been zapped 34671de9992fSLi zeming * by a different task, but the root page should always be 34681de9992fSLi zeming * available as the vCPU holds a reference to its root(s). 34691de9992fSLi zeming */ 34701de9992fSLi zeming if (WARN_ON_ONCE(!sptep)) 34711de9992fSLi zeming spte = REMOVED_SPTE; 34721de9992fSLi zeming 3473ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3474ec89e643SSean Christopherson break; 3475ec89e643SSean Christopherson 34766e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3477c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3478c50d8ae3SPaolo Bonzini break; 3479c50d8ae3SPaolo Bonzini 3480c50d8ae3SPaolo Bonzini /* 3481c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3482c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3483c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3484c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3485c50d8ae3SPaolo Bonzini * current CPU took the fault. 3486c50d8ae3SPaolo Bonzini * 3487c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3488c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3489c50d8ae3SPaolo Bonzini */ 34903c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3491c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3492c50d8ae3SPaolo Bonzini break; 3493c50d8ae3SPaolo Bonzini } 3494c50d8ae3SPaolo Bonzini 3495c50d8ae3SPaolo Bonzini new_spte = spte; 3496c50d8ae3SPaolo Bonzini 349754275f74SSean Christopherson /* 349854275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 349954275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 350054275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 350154275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 350254275f74SSean Christopherson */ 350354275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3504c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3505c50d8ae3SPaolo Bonzini 3506c50d8ae3SPaolo Bonzini /* 350754275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 350854275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 350954275f74SSean Christopherson * that were write-protected for dirty-logging or access 351054275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 351154275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 351254275f74SSean Christopherson * The is_access_allowed() check above handles the common case 351354275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 351454275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 351554275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3516c50d8ae3SPaolo Bonzini */ 3517706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3518c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3519c50d8ae3SPaolo Bonzini 3520c50d8ae3SPaolo Bonzini /* 352110c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 352210c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 352310c30de0SJunaid Shahid * first page into the dirty-bitmap in 3524c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3525c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3526c50d8ae3SPaolo Bonzini * 3527c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3528c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3529c50d8ae3SPaolo Bonzini */ 353010c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 353110c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3532c50d8ae3SPaolo Bonzini break; 3533c50d8ae3SPaolo Bonzini } 3534c50d8ae3SPaolo Bonzini 3535c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3536c50d8ae3SPaolo Bonzini if (new_spte == spte || 35373c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3538c50d8ae3SPaolo Bonzini break; 3539c50d8ae3SPaolo Bonzini 3540c50d8ae3SPaolo Bonzini /* 3541c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3542c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 35433ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3544c50d8ae3SPaolo Bonzini */ 3545e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3546c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3547c50d8ae3SPaolo Bonzini break; 3548c4371c2aSSean Christopherson } 3549c50d8ae3SPaolo Bonzini 3550c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 35518d20bd63SSean Christopherson pr_warn_once("Fast #PF retrying more than 4 times.\n"); 3552c50d8ae3SPaolo Bonzini break; 3553c50d8ae3SPaolo Bonzini } 3554c50d8ae3SPaolo Bonzini 3555c50d8ae3SPaolo Bonzini } while (true); 3556c50d8ae3SPaolo Bonzini 3557f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3558c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3559c50d8ae3SPaolo Bonzini 35601075d41eSSean Christopherson if (ret != RET_PF_INVALID) 35611075d41eSSean Christopherson vcpu->stat.pf_fast++; 35621075d41eSSean Christopherson 3563c4371c2aSSean Christopherson return ret; 3564c50d8ae3SPaolo Bonzini } 3565c50d8ae3SPaolo Bonzini 3566c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3567c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3568c50d8ae3SPaolo Bonzini { 3569c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3570c50d8ae3SPaolo Bonzini 3571c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3572c50d8ae3SPaolo Bonzini return; 3573c50d8ae3SPaolo Bonzini 3574c5f2d564SSean Christopherson sp = root_to_sp(*root_hpa); 357520ba462dSSean Christopherson if (WARN_ON_ONCE(!sp)) 35769191b8f0SPaolo Bonzini return; 357702c00b3aSBen Gardon 3578576a15deSSean Christopherson if (is_tdp_mmu_page(sp)) { 3579576a15deSSean Christopherson lockdep_assert_held_read(&kvm->mmu_lock); 35805f3c8c91SPaolo Bonzini kvm_tdp_mmu_put_root(kvm, sp); 3581576a15deSSean Christopherson } else { 3582576a15deSSean Christopherson lockdep_assert_held_write(&kvm->mmu_lock); 3583576a15deSSean Christopherson if (!--sp->root_count && sp->role.invalid) 3584c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3585576a15deSSean Christopherson } 3586c50d8ae3SPaolo Bonzini 3587c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3588c50d8ae3SPaolo Bonzini } 3589c50d8ae3SPaolo Bonzini 3590c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 35910c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3592c50d8ae3SPaolo Bonzini ulong roots_to_free) 3593c50d8ae3SPaolo Bonzini { 3594576a15deSSean Christopherson bool is_tdp_mmu = tdp_mmu_enabled && mmu->root_role.direct; 3595c50d8ae3SPaolo Bonzini int i; 3596c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3597594bef79SPaolo Bonzini bool free_active_root; 3598c50d8ae3SPaolo Bonzini 3599f94db0c8SSean Christopherson WARN_ON_ONCE(roots_to_free & ~KVM_MMU_ROOTS_ALL); 3600f94db0c8SSean Christopherson 3601c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3602c50d8ae3SPaolo Bonzini 3603c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3604594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3605594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3606594bef79SPaolo Bonzini 3607594bef79SPaolo Bonzini if (!free_active_root) { 3608c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3609c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3610c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3611c50d8ae3SPaolo Bonzini break; 3612c50d8ae3SPaolo Bonzini 3613c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3614c50d8ae3SPaolo Bonzini return; 3615c50d8ae3SPaolo Bonzini } 3616c50d8ae3SPaolo Bonzini 3617576a15deSSean Christopherson if (is_tdp_mmu) 3618576a15deSSean Christopherson read_lock(&kvm->mmu_lock); 3619576a15deSSean Christopherson else 3620531810caSBen Gardon write_lock(&kvm->mmu_lock); 3621c50d8ae3SPaolo Bonzini 3622c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3623c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 36244d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3625c50d8ae3SPaolo Bonzini &invalid_list); 3626c50d8ae3SPaolo Bonzini 3627c50d8ae3SPaolo Bonzini if (free_active_root) { 36280e3223d8SSean Christopherson if (kvm_mmu_is_dummy_root(mmu->root.hpa)) { 36290e3223d8SSean Christopherson /* Nothing to cleanup for dummy roots. */ 36300e3223d8SSean Christopherson } else if (root_to_sp(mmu->root.hpa)) { 3631b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 363204d45551SSean Christopherson } else if (mmu->pae_root) { 3633c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3634c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3635c834e5e4SSean Christopherson continue; 3636c834e5e4SSean Christopherson 3637c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3638c50d8ae3SPaolo Bonzini &invalid_list); 3639c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3640c50d8ae3SPaolo Bonzini } 3641c50d8ae3SPaolo Bonzini } 3642b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3643b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3644c50d8ae3SPaolo Bonzini } 3645c50d8ae3SPaolo Bonzini 3646576a15deSSean Christopherson if (is_tdp_mmu) { 3647576a15deSSean Christopherson read_unlock(&kvm->mmu_lock); 3648576a15deSSean Christopherson WARN_ON_ONCE(!list_empty(&invalid_list)); 3649576a15deSSean Christopherson } else { 36504d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3651531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3652c50d8ae3SPaolo Bonzini } 3653576a15deSSean Christopherson } 3654c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3655c50d8ae3SPaolo Bonzini 36560c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 365725b62c62SSean Christopherson { 365825b62c62SSean Christopherson unsigned long roots_to_free = 0; 3659c5f2d564SSean Christopherson struct kvm_mmu_page *sp; 366025b62c62SSean Christopherson hpa_t root_hpa; 366125b62c62SSean Christopherson int i; 366225b62c62SSean Christopherson 366325b62c62SSean Christopherson /* 366425b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 366525b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 366625b62c62SSean Christopherson */ 36677a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 366825b62c62SSean Christopherson 366925b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 367025b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 367125b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 367225b62c62SSean Christopherson continue; 367325b62c62SSean Christopherson 3674c5f2d564SSean Christopherson sp = root_to_sp(root_hpa); 3675c5f2d564SSean Christopherson if (!sp || sp->role.guest_mode) 367625b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 367725b62c62SSean Christopherson } 367825b62c62SSean Christopherson 36790c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 368025b62c62SSean Christopherson } 368125b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 368225b62c62SSean Christopherson 36832e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 368486938ab6SDavid Matlack u8 level) 3685c50d8ae3SPaolo Bonzini { 36862e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3687c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 36888123f265SSean Christopherson 36892e65e842SDavid Matlack role.level = level; 36902e65e842SDavid Matlack role.quadrant = quadrant; 36912e65e842SDavid Matlack 36927f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 36937f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 36947f497775SDavid Matlack 369587654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 36968123f265SSean Christopherson ++sp->root_count; 36978123f265SSean Christopherson 36988123f265SSean Christopherson return __pa(sp->spt); 36998123f265SSean Christopherson } 37008123f265SSean Christopherson 37018123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 37028123f265SSean Christopherson { 3703b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3704a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 37058123f265SSean Christopherson hpa_t root; 3706c50d8ae3SPaolo Bonzini unsigned i; 37074a38162eSPaolo Bonzini int r; 37084a38162eSPaolo Bonzini 3709f5238c2aSSean Christopherson if (tdp_mmu_enabled) 3710f5238c2aSSean Christopherson return kvm_tdp_mmu_alloc_root(vcpu); 3711f5238c2aSSean Christopherson 37124a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 37134a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 37144a38162eSPaolo Bonzini if (r < 0) 37154a38162eSPaolo Bonzini goto out_unlock; 3716c50d8ae3SPaolo Bonzini 3717f5238c2aSSean Christopherson if (shadow_root_level >= PT64_ROOT_4LEVEL) { 371886938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3719b9e5603cSPaolo Bonzini mmu->root.hpa = root; 37208123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 37214a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 37224a38162eSPaolo Bonzini r = -EIO; 37234a38162eSPaolo Bonzini goto out_unlock; 37244a38162eSPaolo Bonzini } 372573ad1606SSean Christopherson 3726c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3727c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3728c50d8ae3SPaolo Bonzini 37297f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 37302e65e842SDavid Matlack PT32_ROOT_LEVEL); 373117e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3732d2263de1SYuan Yao shadow_me_value; 3733c50d8ae3SPaolo Bonzini } 3734b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 373573ad1606SSean Christopherson } else { 373673ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 37374a38162eSPaolo Bonzini r = -EIO; 37384a38162eSPaolo Bonzini goto out_unlock; 373973ad1606SSean Christopherson } 37403651c7fcSSean Christopherson 3741b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3742b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 37434a38162eSPaolo Bonzini out_unlock: 37444a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 37454a38162eSPaolo Bonzini return r; 3746c50d8ae3SPaolo Bonzini } 3747c50d8ae3SPaolo Bonzini 37481e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 37491e76a3ceSDavid Stevens { 37501e76a3ceSDavid Stevens struct kvm_memslots *slots; 37511e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3752a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 37531e76a3ceSDavid Stevens 37541e76a3ceSDavid Stevens /* 37551e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 37561e76a3ceSDavid Stevens * taking the lock. 37571e76a3ceSDavid Stevens */ 37581e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37591e76a3ceSDavid Stevens return 0; 37601e76a3ceSDavid Stevens 37611e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 37621e76a3ceSDavid Stevens 37631e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 37641e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37651e76a3ceSDavid Stevens goto out_unlock; 37661e76a3ceSDavid Stevens 37671e76a3ceSDavid Stevens /* 37681e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 37691e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 37701e76a3ceSDavid Stevens */ 37711e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 37721e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 37731e76a3ceSDavid Stevens goto out_success; 37741e76a3ceSDavid Stevens 3775eed52e43SSean Christopherson for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { 37761e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3777a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 37781e76a3ceSDavid Stevens /* 37791e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 37801e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 37811e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 37821e76a3ceSDavid Stevens * failure to avoid having to track which allocations 37831e76a3ceSDavid Stevens * were made now versus when the memslot was created. 37841e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 37851e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 37861e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 37871e76a3ceSDavid Stevens */ 37881e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 37891e76a3ceSDavid Stevens if (r) 37901e76a3ceSDavid Stevens goto out_unlock; 37911e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 37921e76a3ceSDavid Stevens if (r) 37931e76a3ceSDavid Stevens goto out_unlock; 37941e76a3ceSDavid Stevens } 37951e76a3ceSDavid Stevens } 37961e76a3ceSDavid Stevens 37971e76a3ceSDavid Stevens /* 37981e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 37991e76a3ceSDavid Stevens * all the related pointers are set. 38001e76a3ceSDavid Stevens */ 38011e76a3ceSDavid Stevens out_success: 38021e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 38031e76a3ceSDavid Stevens 38041e76a3ceSDavid Stevens out_unlock: 38051e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 38061e76a3ceSDavid Stevens return r; 38071e76a3ceSDavid Stevens } 38081e76a3ceSDavid Stevens 3809c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3810c50d8ae3SPaolo Bonzini { 3811b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 38126e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3813be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 38147f497775SDavid Matlack int quadrant, i, r; 38158123f265SSean Christopherson hpa_t root; 3816c50d8ae3SPaolo Bonzini 38172fdcc1b3SPaolo Bonzini root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu); 3818a130066fSBinbin Wu root_gfn = (root_pgd & __PT_BASE_ADDR_MASK) >> PAGE_SHIFT; 3819c50d8ae3SPaolo Bonzini 38200e3223d8SSean Christopherson if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 38210e3223d8SSean Christopherson mmu->root.hpa = kvm_mmu_get_dummy_root(); 38220e3223d8SSean Christopherson return 0; 38230e3223d8SSean Christopherson } 3824c50d8ae3SPaolo Bonzini 3825c50d8ae3SPaolo Bonzini /* 38264a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 38274a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 38284a38162eSPaolo Bonzini */ 38294d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38306e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 38316e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 38326e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 38336e0918aeSSean Christopherson continue; 38346e0918aeSSean Christopherson 38350e3223d8SSean Christopherson if (!kvm_vcpu_is_visible_gfn(vcpu, pdptrs[i] >> PAGE_SHIFT)) 38360e3223d8SSean Christopherson pdptrs[i] = 0; 38376e0918aeSSean Christopherson } 38386e0918aeSSean Christopherson } 38396e0918aeSSean Christopherson 38401e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3841d501f747SBen Gardon if (r) 3842d501f747SBen Gardon return r; 3843d501f747SBen Gardon 38444a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 38454a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 38464a38162eSPaolo Bonzini if (r < 0) 38474a38162eSPaolo Bonzini goto out_unlock; 38484a38162eSPaolo Bonzini 3849c50d8ae3SPaolo Bonzini /* 3850c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3851c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3852c50d8ae3SPaolo Bonzini */ 38534d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 38548123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 385586938ab6SDavid Matlack mmu->root_role.level); 3856b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3857be01e8e2SSean Christopherson goto set_root_pgd; 3858c50d8ae3SPaolo Bonzini } 3859c50d8ae3SPaolo Bonzini 38604a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 38614a38162eSPaolo Bonzini r = -EIO; 38624a38162eSPaolo Bonzini goto out_unlock; 38634a38162eSPaolo Bonzini } 386473ad1606SSean Christopherson 3865c50d8ae3SPaolo Bonzini /* 3866c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3867c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3868c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3869c50d8ae3SPaolo Bonzini */ 3870e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3871a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3872c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3873c50d8ae3SPaolo Bonzini 387403ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 38754a38162eSPaolo Bonzini r = -EIO; 38764a38162eSPaolo Bonzini goto out_unlock; 38774a38162eSPaolo Bonzini } 387803ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3879cb0f722aSWei Huang 3880a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3881cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3882cb0f722aSWei Huang r = -EIO; 3883cb0f722aSWei Huang goto out_unlock; 3884cb0f722aSWei Huang } 3885cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3886cb0f722aSWei Huang } 388704d45551SSean Christopherson } 388804d45551SSean Christopherson 3889c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3890c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 38916e6ec584SSean Christopherson 38924d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38936e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3894c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3895c50d8ae3SPaolo Bonzini continue; 3896c50d8ae3SPaolo Bonzini } 38976e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3898c50d8ae3SPaolo Bonzini } 3899c50d8ae3SPaolo Bonzini 39007f497775SDavid Matlack /* 39017f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 39027f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 39037f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 39047f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 39057f497775SDavid Matlack */ 39067f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 39077f497775SDavid Matlack 39087f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3909b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3910c50d8ae3SPaolo Bonzini } 3911c50d8ae3SPaolo Bonzini 3912a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3913b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3914a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3915b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3916ba0a194fSSean Christopherson else 3917b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3918c50d8ae3SPaolo Bonzini 3919be01e8e2SSean Christopherson set_root_pgd: 3920b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 39214a38162eSPaolo Bonzini out_unlock: 39224a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3923c50d8ae3SPaolo Bonzini 3924c6c937d6SLike Xu return r; 3925c50d8ae3SPaolo Bonzini } 3926c50d8ae3SPaolo Bonzini 3927748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3928c50d8ae3SPaolo Bonzini { 3929748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3930a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3931cb0f722aSWei Huang u64 *pml5_root = NULL; 3932cb0f722aSWei Huang u64 *pml4_root = NULL; 3933cb0f722aSWei Huang u64 *pae_root; 3934748e52b9SSean Christopherson 3935748e52b9SSean Christopherson /* 3936748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3937748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3938748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3939748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3940748e52b9SSean Christopherson */ 3941347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3942347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3943a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3944748e52b9SSean Christopherson return 0; 3945748e52b9SSean Christopherson 3946a717a780SSean Christopherson /* 3947a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3948a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3949a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3950a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3951a717a780SSean Christopherson * prior MMU would also have required pml5. 3952a717a780SSean Christopherson */ 3953a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3954748e52b9SSean Christopherson return 0; 3955748e52b9SSean Christopherson 3956748e52b9SSean Christopherson /* 3957748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3958748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3959748e52b9SSean Christopherson */ 3960cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3961a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3962748e52b9SSean Christopherson return -EIO; 3963748e52b9SSean Christopherson 39644a98623dSSean Christopherson /* 39654a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 39664a98623dSSean Christopherson * doesn't need to be decrypted. 39674a98623dSSean Christopherson */ 3968748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3969748e52b9SSean Christopherson if (!pae_root) 3970748e52b9SSean Christopherson return -ENOMEM; 3971748e52b9SSean Christopherson 3972cb0f722aSWei Huang #ifdef CONFIG_X86_64 397303ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3974cb0f722aSWei Huang if (!pml4_root) 3975cb0f722aSWei Huang goto err_pml4; 3976cb0f722aSWei Huang 3977a717a780SSean Christopherson if (need_pml5) { 3978cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3979cb0f722aSWei Huang if (!pml5_root) 3980cb0f722aSWei Huang goto err_pml5; 3981748e52b9SSean Christopherson } 3982cb0f722aSWei Huang #endif 3983748e52b9SSean Christopherson 3984748e52b9SSean Christopherson mmu->pae_root = pae_root; 398503ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3986cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3987748e52b9SSean Christopherson 3988748e52b9SSean Christopherson return 0; 3989cb0f722aSWei Huang 3990cb0f722aSWei Huang #ifdef CONFIG_X86_64 3991cb0f722aSWei Huang err_pml5: 3992cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3993cb0f722aSWei Huang err_pml4: 3994cb0f722aSWei Huang free_page((unsigned long)pae_root); 3995cb0f722aSWei Huang return -ENOMEM; 3996cb0f722aSWei Huang #endif 3997c50d8ae3SPaolo Bonzini } 3998c50d8ae3SPaolo Bonzini 3999264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 4000264d3dc1SLai Jiangshan { 4001264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 4002264d3dc1SLai Jiangshan 40030e3223d8SSean Christopherson if (!VALID_PAGE(root) || kvm_mmu_is_dummy_root(root)) 400461b05a9fSLai Jiangshan return false; 400561b05a9fSLai Jiangshan 4006264d3dc1SLai Jiangshan /* 4007264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 4008264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 4009264d3dc1SLai Jiangshan * 4010264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 4011264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 4012264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 4013264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 4014264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 4015264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 4016264d3dc1SLai Jiangshan * requirement isn't satisfied. 4017264d3dc1SLai Jiangshan */ 4018264d3dc1SLai Jiangshan smp_rmb(); 4019c5f2d564SSean Christopherson sp = root_to_sp(root); 40205d6a3221SSean Christopherson 40215d6a3221SSean Christopherson /* 40225d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 40235d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 40245d6a3221SSean Christopherson */ 40255d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 40265d6a3221SSean Christopherson return false; 40275d6a3221SSean Christopherson 4028264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 4029264d3dc1SLai Jiangshan return true; 4030264d3dc1SLai Jiangshan 4031264d3dc1SLai Jiangshan return false; 4032264d3dc1SLai Jiangshan } 4033264d3dc1SLai Jiangshan 4034c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 4035c50d8ae3SPaolo Bonzini { 4036c50d8ae3SPaolo Bonzini int i; 4037c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 4038c50d8ae3SPaolo Bonzini 4039347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 4040c50d8ae3SPaolo Bonzini return; 4041c50d8ae3SPaolo Bonzini 4042b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 4043c50d8ae3SPaolo Bonzini return; 4044c50d8ae3SPaolo Bonzini 4045c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4046c50d8ae3SPaolo Bonzini 40474d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 4048b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 4049c50d8ae3SPaolo Bonzini 4050264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 4051c50d8ae3SPaolo Bonzini return; 4052c50d8ae3SPaolo Bonzini 4053c5f2d564SSean Christopherson sp = root_to_sp(root); 4054c5f2d564SSean Christopherson 4055531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 405665855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4057531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4058c50d8ae3SPaolo Bonzini return; 4059c50d8ae3SPaolo Bonzini } 4060c50d8ae3SPaolo Bonzini 4061531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4062c50d8ae3SPaolo Bonzini 4063c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 4064c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 4065c50d8ae3SPaolo Bonzini 4066c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 40675e3edd7eSSean Christopherson sp = spte_to_child_sp(root); 406865855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4069c50d8ae3SPaolo Bonzini } 4070c50d8ae3SPaolo Bonzini } 4071c50d8ae3SPaolo Bonzini 4072531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4073c50d8ae3SPaolo Bonzini } 4074c50d8ae3SPaolo Bonzini 407561b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 407661b05a9fSLai Jiangshan { 407761b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 407861b05a9fSLai Jiangshan int i; 407961b05a9fSLai Jiangshan 408061b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 408161b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 408261b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 408361b05a9fSLai Jiangshan 408461b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 40850c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 408661b05a9fSLai Jiangshan } 408761b05a9fSLai Jiangshan 40881f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 40895b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 4090c50d8ae3SPaolo Bonzini struct x86_exception *exception) 4091c50d8ae3SPaolo Bonzini { 4092c50d8ae3SPaolo Bonzini if (exception) 4093c50d8ae3SPaolo Bonzini exception->error_code = 0; 4094c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 4095c50d8ae3SPaolo Bonzini } 4096c50d8ae3SPaolo Bonzini 4097c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4098c50d8ae3SPaolo Bonzini { 4099c50d8ae3SPaolo Bonzini /* 4100c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 4101c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 4102c50d8ae3SPaolo Bonzini */ 4103c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 4104c50d8ae3SPaolo Bonzini return false; 4105c50d8ae3SPaolo Bonzini 4106c50d8ae3SPaolo Bonzini if (direct) 4107c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 4108c50d8ae3SPaolo Bonzini 4109c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 4110c50d8ae3SPaolo Bonzini } 4111c50d8ae3SPaolo Bonzini 411295fb5b02SBen Gardon /* 411395fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 411495fb5b02SBen Gardon * That SPTE may be non-present. 4115c5c8c7c5SDavid Matlack * 4116c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 411795fb5b02SBen Gardon */ 411839b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 4119c50d8ae3SPaolo Bonzini { 4120c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 41212aa07893SSean Christopherson int leaf = -1; 412295fb5b02SBen Gardon u64 spte; 4123c50d8ae3SPaolo Bonzini 412439b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 412539b4d43eSSean Christopherson *root_level = iterator.level; 4126c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 4127c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 412895fb5b02SBen Gardon leaf = iterator.level; 4129c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 4130c50d8ae3SPaolo Bonzini 4131dde81f94SSean Christopherson sptes[leaf] = spte; 413295fb5b02SBen Gardon } 413395fb5b02SBen Gardon 413495fb5b02SBen Gardon return leaf; 413595fb5b02SBen Gardon } 413695fb5b02SBen Gardon 41379aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 413895fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 413995fb5b02SBen Gardon { 4140dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 414195fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 414239b4d43eSSean Christopherson int root, leaf, level; 414395fb5b02SBen Gardon bool reserved = false; 414495fb5b02SBen Gardon 4145c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 4146c5c8c7c5SDavid Matlack 414778fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) 414839b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 414995fb5b02SBen Gardon else 415039b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 415195fb5b02SBen Gardon 4152c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 4153c5c8c7c5SDavid Matlack 41542aa07893SSean Christopherson if (unlikely(leaf < 0)) { 41552aa07893SSean Christopherson *sptep = 0ull; 41562aa07893SSean Christopherson return reserved; 41572aa07893SSean Christopherson } 41582aa07893SSean Christopherson 41599aa41879SSean Christopherson *sptep = sptes[leaf]; 41609aa41879SSean Christopherson 41619aa41879SSean Christopherson /* 41629aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 41639aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 41649aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 41659aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 41669aa41879SSean Christopherson */ 41679aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 41689aa41879SSean Christopherson leaf++; 416995fb5b02SBen Gardon 417095fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 417195fb5b02SBen Gardon 41729aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4173961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4174c50d8ae3SPaolo Bonzini 4175c50d8ae3SPaolo Bonzini if (reserved) { 4176bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4177c50d8ae3SPaolo Bonzini __func__, addr); 417895fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4179bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4180bb4cdf3aSSean Christopherson sptes[level], level, 4181961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4182c50d8ae3SPaolo Bonzini } 4183ddce6208SSean Christopherson 4184c50d8ae3SPaolo Bonzini return reserved; 4185c50d8ae3SPaolo Bonzini } 4186c50d8ae3SPaolo Bonzini 4187c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4188c50d8ae3SPaolo Bonzini { 4189c50d8ae3SPaolo Bonzini u64 spte; 4190c50d8ae3SPaolo Bonzini bool reserved; 4191c50d8ae3SPaolo Bonzini 4192c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4193c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4194c50d8ae3SPaolo Bonzini 419595fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 419620ba462dSSean Christopherson if (WARN_ON_ONCE(reserved)) 4197c50d8ae3SPaolo Bonzini return -EINVAL; 4198c50d8ae3SPaolo Bonzini 4199c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4200c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 42010a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4202c50d8ae3SPaolo Bonzini 4203c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4204c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4205c50d8ae3SPaolo Bonzini 4206c50d8ae3SPaolo Bonzini if (direct) 4207c50d8ae3SPaolo Bonzini addr = 0; 4208c50d8ae3SPaolo Bonzini 4209c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4210c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4211c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4212c50d8ae3SPaolo Bonzini } 4213c50d8ae3SPaolo Bonzini 4214c50d8ae3SPaolo Bonzini /* 4215c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4216c50d8ae3SPaolo Bonzini * the address. 4217c50d8ae3SPaolo Bonzini */ 4218c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4219c50d8ae3SPaolo Bonzini } 4220c50d8ae3SPaolo Bonzini 4221c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4222b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4223c50d8ae3SPaolo Bonzini { 4224b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4225c50d8ae3SPaolo Bonzini return false; 4226c50d8ae3SPaolo Bonzini 4227b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4228c50d8ae3SPaolo Bonzini return false; 4229c50d8ae3SPaolo Bonzini 4230c50d8ae3SPaolo Bonzini /* 4231c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4232c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4233c50d8ae3SPaolo Bonzini */ 42347b574863SSean Christopherson if (kvm_gfn_is_write_tracked(vcpu->kvm, fault->slot, fault->gfn)) 4235c50d8ae3SPaolo Bonzini return true; 4236c50d8ae3SPaolo Bonzini 4237c50d8ae3SPaolo Bonzini return false; 4238c50d8ae3SPaolo Bonzini } 4239c50d8ae3SPaolo Bonzini 4240c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4241c50d8ae3SPaolo Bonzini { 4242c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4243c50d8ae3SPaolo Bonzini u64 spte; 4244c50d8ae3SPaolo Bonzini 4245c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 42463e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4247c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4248c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4249c50d8ae3SPaolo Bonzini } 4250c50d8ae3SPaolo Bonzini 42516f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 42526f3c1fc5SLiang Zhang { 42536f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 42546f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 42556f3c1fc5SLiang Zhang 42566f3c1fc5SLiang Zhang if (id << 12 == 0) 42576f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 42586f3c1fc5SLiang Zhang 42596f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 42606f3c1fc5SLiang Zhang } 42616f3c1fc5SLiang Zhang 4262e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 42639f1a8526SSean Christopherson gfn_t gfn) 4264c50d8ae3SPaolo Bonzini { 4265c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4266c50d8ae3SPaolo Bonzini 42676f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4268c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4269347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 42702fdcc1b3SPaolo Bonzini arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu); 4271c50d8ae3SPaolo Bonzini 42729f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 42739f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4274c50d8ae3SPaolo Bonzini } 4275c50d8ae3SPaolo Bonzini 42768a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 42778a009d5bSSean Christopherson { 42788a009d5bSSean Christopherson int r; 42798a009d5bSSean Christopherson 42808a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 42818a009d5bSSean Christopherson work->wakeup_all) 42828a009d5bSSean Christopherson return; 42838a009d5bSSean Christopherson 42848a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 42858a009d5bSSean Christopherson if (unlikely(r)) 42868a009d5bSSean Christopherson return; 42878a009d5bSSean Christopherson 42888a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 42892fdcc1b3SPaolo Bonzini work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu)) 42908a009d5bSSean Christopherson return; 42918a009d5bSSean Christopherson 4292258d985fSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true, NULL); 42938a009d5bSSean Christopherson } 42948a009d5bSSean Christopherson 42958dd2eee9SChao Peng static inline u8 kvm_max_level_for_order(int order) 42968dd2eee9SChao Peng { 42978dd2eee9SChao Peng BUILD_BUG_ON(KVM_MAX_HUGEPAGE_LEVEL > PG_LEVEL_1G); 42988dd2eee9SChao Peng 42998dd2eee9SChao Peng KVM_MMU_WARN_ON(order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_1G) && 43008dd2eee9SChao Peng order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_2M) && 43018dd2eee9SChao Peng order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_4K)); 43028dd2eee9SChao Peng 43038dd2eee9SChao Peng if (order >= KVM_HPAGE_GFN_SHIFT(PG_LEVEL_1G)) 43048dd2eee9SChao Peng return PG_LEVEL_1G; 43058dd2eee9SChao Peng 43068dd2eee9SChao Peng if (order >= KVM_HPAGE_GFN_SHIFT(PG_LEVEL_2M)) 43078dd2eee9SChao Peng return PG_LEVEL_2M; 43088dd2eee9SChao Peng 43098dd2eee9SChao Peng return PG_LEVEL_4K; 43108dd2eee9SChao Peng } 43118dd2eee9SChao Peng 43128dd2eee9SChao Peng static void kvm_mmu_prepare_memory_fault_exit(struct kvm_vcpu *vcpu, 43138dd2eee9SChao Peng struct kvm_page_fault *fault) 43148dd2eee9SChao Peng { 43158dd2eee9SChao Peng kvm_prepare_memory_fault_exit(vcpu, fault->gfn << PAGE_SHIFT, 43168dd2eee9SChao Peng PAGE_SIZE, fault->write, fault->exec, 43178dd2eee9SChao Peng fault->is_private); 43188dd2eee9SChao Peng } 43198dd2eee9SChao Peng 43208dd2eee9SChao Peng static int kvm_faultin_pfn_private(struct kvm_vcpu *vcpu, 43218dd2eee9SChao Peng struct kvm_page_fault *fault) 43228dd2eee9SChao Peng { 43238dd2eee9SChao Peng int max_order, r; 43248dd2eee9SChao Peng 43258dd2eee9SChao Peng if (!kvm_slot_can_be_private(fault->slot)) { 43268dd2eee9SChao Peng kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 43278dd2eee9SChao Peng return -EFAULT; 43288dd2eee9SChao Peng } 43298dd2eee9SChao Peng 43308dd2eee9SChao Peng r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn, 43318dd2eee9SChao Peng &max_order); 43328dd2eee9SChao Peng if (r) { 43338dd2eee9SChao Peng kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 43348dd2eee9SChao Peng return r; 43358dd2eee9SChao Peng } 43368dd2eee9SChao Peng 43378dd2eee9SChao Peng fault->max_level = min(kvm_max_level_for_order(max_order), 43388dd2eee9SChao Peng fault->max_level); 43398dd2eee9SChao Peng fault->map_writable = !(fault->slot->flags & KVM_MEM_READONLY); 43408dd2eee9SChao Peng 43418dd2eee9SChao Peng return RET_PF_CONTINUE; 43428dd2eee9SChao Peng } 43438dd2eee9SChao Peng 4344ba6e3fe2SDavid Matlack static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4345c50d8ae3SPaolo Bonzini { 4346e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4347c50d8ae3SPaolo Bonzini bool async; 4348c50d8ae3SPaolo Bonzini 4349e0c37868SSean Christopherson /* 4350e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4351e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4352e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4353e0c37868SSean Christopherson */ 4354e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 43555276c616SSean Christopherson return RET_PF_RETRY; 4356e0c37868SSean Christopherson 43579cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4358c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 43599cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4360e710c5f6SDavid Matlack fault->slot = NULL; 43613647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 43623647cd04SPaolo Bonzini fault->map_writable = false; 43635276c616SSean Christopherson return RET_PF_CONTINUE; 4364c50d8ae3SPaolo Bonzini } 43659cc13d60SMaxim Levitsky /* 43669cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 43679cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 43689cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 43699cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 43709cc13d60SMaxim Levitsky */ 43719cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 43725276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 43735276c616SSean Christopherson return RET_PF_EMULATE; 43749cc13d60SMaxim Levitsky } 4375c50d8ae3SPaolo Bonzini 43768dd2eee9SChao Peng if (fault->is_private != kvm_mem_is_private(vcpu->kvm, fault->gfn)) { 43778dd2eee9SChao Peng kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 43788dd2eee9SChao Peng return -EFAULT; 43798dd2eee9SChao Peng } 43808dd2eee9SChao Peng 43818dd2eee9SChao Peng if (fault->is_private) 43828dd2eee9SChao Peng return kvm_faultin_pfn_private(vcpu, fault); 43838dd2eee9SChao Peng 4384c50d8ae3SPaolo Bonzini async = false; 4385c8b88b33SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, 43863647cd04SPaolo Bonzini fault->write, &fault->map_writable, 43873647cd04SPaolo Bonzini &fault->hva); 4388c50d8ae3SPaolo Bonzini if (!async) 43895276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4390c50d8ae3SPaolo Bonzini 43912839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 43923647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 43933647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 43941685c0f3SMingwei Zhang trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4395c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 43965276c616SSean Christopherson return RET_PF_RETRY; 43975276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 43985276c616SSean Christopherson return RET_PF_RETRY; 43995276c616SSean Christopherson } 4400c50d8ae3SPaolo Bonzini } 4401c50d8ae3SPaolo Bonzini 440276657687SPeter Xu /* 440376657687SPeter Xu * Allow gup to bail on pending non-fatal signals when it's also allowed 440476657687SPeter Xu * to wait for IO. Note, gup always bails if it is unable to quickly 440576657687SPeter Xu * get a page and a fatal signal, i.e. SIGKILL, is pending. 440676657687SPeter Xu */ 440776657687SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, 44083647cd04SPaolo Bonzini fault->write, &fault->map_writable, 44093647cd04SPaolo Bonzini &fault->hva); 44105276c616SSean Christopherson return RET_PF_CONTINUE; 4411c50d8ae3SPaolo Bonzini } 4412c50d8ae3SPaolo Bonzini 4413354c908cSDavid Matlack static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 4414354c908cSDavid Matlack unsigned int access) 4415ba6e3fe2SDavid Matlack { 441656c3a4e4SDavid Matlack int ret; 441756c3a4e4SDavid Matlack 4418ba6e3fe2SDavid Matlack fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4419ba6e3fe2SDavid Matlack smp_rmb(); 4420ba6e3fe2SDavid Matlack 4421d02c357eSSean Christopherson /* 4422d02c357eSSean Christopherson * Check for a relevant mmu_notifier invalidation event before getting 4423d02c357eSSean Christopherson * the pfn from the primary MMU, and before acquiring mmu_lock. 4424d02c357eSSean Christopherson * 4425d02c357eSSean Christopherson * For mmu_lock, if there is an in-progress invalidation and the kernel 4426d02c357eSSean Christopherson * allows preemption, the invalidation task may drop mmu_lock and yield 4427d02c357eSSean Christopherson * in response to mmu_lock being contended, which is *very* counter- 4428d02c357eSSean Christopherson * productive as this vCPU can't actually make forward progress until 4429d02c357eSSean Christopherson * the invalidation completes. 4430d02c357eSSean Christopherson * 4431d02c357eSSean Christopherson * Retrying now can also avoid unnessary lock contention in the primary 4432d02c357eSSean Christopherson * MMU, as the primary MMU doesn't necessarily hold a single lock for 4433d02c357eSSean Christopherson * the duration of the invalidation, i.e. faulting in a conflicting pfn 4434d02c357eSSean Christopherson * can cause the invalidation to take longer by holding locks that are 4435d02c357eSSean Christopherson * needed to complete the invalidation. 4436d02c357eSSean Christopherson * 4437d02c357eSSean Christopherson * Do the pre-check even for non-preemtible kernels, i.e. even if KVM 4438d02c357eSSean Christopherson * will never yield mmu_lock in response to contention, as this vCPU is 4439d02c357eSSean Christopherson * *guaranteed* to need to retry, i.e. waiting until mmu_lock is held 4440d02c357eSSean Christopherson * to detect retry guarantees the worst case latency for the vCPU. 4441d02c357eSSean Christopherson */ 4442d02c357eSSean Christopherson if (fault->slot && 4443d02c357eSSean Christopherson mmu_invalidate_retry_gfn_unsafe(vcpu->kvm, fault->mmu_seq, fault->gfn)) 4444d02c357eSSean Christopherson return RET_PF_RETRY; 4445d02c357eSSean Christopherson 444656c3a4e4SDavid Matlack ret = __kvm_faultin_pfn(vcpu, fault); 444756c3a4e4SDavid Matlack if (ret != RET_PF_CONTINUE) 444856c3a4e4SDavid Matlack return ret; 444956c3a4e4SDavid Matlack 445056c3a4e4SDavid Matlack if (unlikely(is_error_pfn(fault->pfn))) 4451cd08d178SDavid Matlack return kvm_handle_error_pfn(vcpu, fault); 445256c3a4e4SDavid Matlack 4453354c908cSDavid Matlack if (unlikely(!fault->slot)) 4454354c908cSDavid Matlack return kvm_handle_noslot_fault(vcpu, fault, access); 4455354c908cSDavid Matlack 4456d02c357eSSean Christopherson /* 4457d02c357eSSean Christopherson * Check again for a relevant mmu_notifier invalidation event purely to 4458d02c357eSSean Christopherson * avoid contending mmu_lock. Most invalidations will be detected by 4459d02c357eSSean Christopherson * the previous check, but checking is extremely cheap relative to the 4460d02c357eSSean Christopherson * overall cost of failing to detect the invalidation until after 4461d02c357eSSean Christopherson * mmu_lock is acquired. 4462d02c357eSSean Christopherson */ 4463d02c357eSSean Christopherson if (mmu_invalidate_retry_gfn_unsafe(vcpu->kvm, fault->mmu_seq, fault->gfn)) { 4464d02c357eSSean Christopherson kvm_release_pfn_clean(fault->pfn); 4465d02c357eSSean Christopherson return RET_PF_RETRY; 4466d02c357eSSean Christopherson } 4467d02c357eSSean Christopherson 446856c3a4e4SDavid Matlack return RET_PF_CONTINUE; 4469ba6e3fe2SDavid Matlack } 4470ba6e3fe2SDavid Matlack 4471a955cad8SSean Christopherson /* 4472a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4473a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4474a955cad8SSean Christopherson */ 4475a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4476ba6e3fe2SDavid Matlack struct kvm_page_fault *fault) 4477a955cad8SSean Christopherson { 4478c5f2d564SSean Christopherson struct kvm_mmu_page *sp = root_to_sp(vcpu->arch.mmu->root.hpa); 447918c841e1SSean Christopherson 448018c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 448118c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 448218c841e1SSean Christopherson return true; 448318c841e1SSean Christopherson 448418c841e1SSean Christopherson /* 448518c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 448618c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 448718c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 448818c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 448918c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 449018c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 449118c841e1SSean Christopherson */ 4492527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4493a955cad8SSean Christopherson return true; 4494a955cad8SSean Christopherson 4495d02c357eSSean Christopherson /* 4496d02c357eSSean Christopherson * Check for a relevant mmu_notifier invalidation event one last time 4497d02c357eSSean Christopherson * now that mmu_lock is held, as the "unsafe" checks performed without 4498d02c357eSSean Christopherson * holding mmu_lock can get false negatives. 4499d02c357eSSean Christopherson */ 4500a955cad8SSean Christopherson return fault->slot && 45018569992dSChao Peng mmu_invalidate_retry_gfn(vcpu->kvm, fault->mmu_seq, fault->gfn); 4502a955cad8SSean Christopherson } 4503a955cad8SSean Christopherson 45044326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4505c50d8ae3SPaolo Bonzini { 450683f06fa7SSean Christopherson int r; 4507c50d8ae3SPaolo Bonzini 45080e3223d8SSean Christopherson /* Dummy roots are used only for shadowing bad guest roots. */ 45090e3223d8SSean Christopherson if (WARN_ON_ONCE(kvm_mmu_is_dummy_root(vcpu->arch.mmu->root.hpa))) 45100e3223d8SSean Christopherson return RET_PF_RETRY; 45110e3223d8SSean Christopherson 4512b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4513c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4514c50d8ae3SPaolo Bonzini 45153c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4516c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4517c4371c2aSSean Christopherson return r; 451883291445SSean Christopherson 4519378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4520c50d8ae3SPaolo Bonzini if (r) 4521c50d8ae3SPaolo Bonzini return r; 4522c50d8ae3SPaolo Bonzini 4523354c908cSDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 45245276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4525367fd790SSean Christopherson return r; 4526367fd790SSean Christopherson 4527367fd790SSean Christopherson r = RET_PF_RETRY; 4528531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4529a2855afcSBen Gardon 4530ba6e3fe2SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 4531367fd790SSean Christopherson goto out_unlock; 4532a955cad8SSean Christopherson 45337bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 45347bd7ded6SSean Christopherson if (r) 4535367fd790SSean Christopherson goto out_unlock; 4536bb18842eSBen Gardon 45376c882ef4SDavid Matlack r = direct_map(vcpu, fault); 45380f90e1c1SSean Christopherson 4539367fd790SSean Christopherson out_unlock: 4540531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 45413647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4542367fd790SSean Christopherson return r; 4543c50d8ae3SPaolo Bonzini } 4544c50d8ae3SPaolo Bonzini 4545c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4546c501040aSPaolo Bonzini struct kvm_page_fault *fault) 45470f90e1c1SSean Christopherson { 45480f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 45494326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 45504326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 45510f90e1c1SSean Christopherson } 45520f90e1c1SSean Christopherson 4553c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4554c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4555c50d8ae3SPaolo Bonzini { 4556c50d8ae3SPaolo Bonzini int r = 1; 45579ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4558c50d8ae3SPaolo Bonzini 4559736c291cSSean Christopherson #ifndef CONFIG_X86_64 4560736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4561736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4562736c291cSSean Christopherson return -EFAULT; 4563736c291cSSean Christopherson #endif 4564736c291cSSean Christopherson 4565c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 45669ce372b3SVitaly Kuznetsov if (!flags) { 4567faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4568c50d8ae3SPaolo Bonzini 4569c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4570c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4571c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4572c50d8ae3SPaolo Bonzini insn_len); 45739ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 457468fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4575c50d8ae3SPaolo Bonzini local_irq_disable(); 45766bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4577c50d8ae3SPaolo Bonzini local_irq_enable(); 45789ce372b3SVitaly Kuznetsov } else { 45799ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4580c50d8ae3SPaolo Bonzini } 45819ce372b3SVitaly Kuznetsov 4582c50d8ae3SPaolo Bonzini return r; 4583c50d8ae3SPaolo Bonzini } 4584c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4585c50d8ae3SPaolo Bonzini 45869aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 45879aa8ab43SDavid Matlack static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, 45889aa8ab43SDavid Matlack struct kvm_page_fault *fault) 45899aa8ab43SDavid Matlack { 45909aa8ab43SDavid Matlack int r; 45919aa8ab43SDavid Matlack 45929aa8ab43SDavid Matlack if (page_fault_handle_page_track(vcpu, fault)) 45939aa8ab43SDavid Matlack return RET_PF_EMULATE; 45949aa8ab43SDavid Matlack 45959aa8ab43SDavid Matlack r = fast_page_fault(vcpu, fault); 45969aa8ab43SDavid Matlack if (r != RET_PF_INVALID) 45979aa8ab43SDavid Matlack return r; 45989aa8ab43SDavid Matlack 45999aa8ab43SDavid Matlack r = mmu_topup_memory_caches(vcpu, false); 46009aa8ab43SDavid Matlack if (r) 46019aa8ab43SDavid Matlack return r; 46029aa8ab43SDavid Matlack 46039aa8ab43SDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 46049aa8ab43SDavid Matlack if (r != RET_PF_CONTINUE) 46059aa8ab43SDavid Matlack return r; 46069aa8ab43SDavid Matlack 46079aa8ab43SDavid Matlack r = RET_PF_RETRY; 46089aa8ab43SDavid Matlack read_lock(&vcpu->kvm->mmu_lock); 46099aa8ab43SDavid Matlack 46109aa8ab43SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 46119aa8ab43SDavid Matlack goto out_unlock; 46129aa8ab43SDavid Matlack 46139aa8ab43SDavid Matlack r = kvm_tdp_mmu_map(vcpu, fault); 46149aa8ab43SDavid Matlack 46159aa8ab43SDavid Matlack out_unlock: 46169aa8ab43SDavid Matlack read_unlock(&vcpu->kvm->mmu_lock); 46179aa8ab43SDavid Matlack kvm_release_pfn_clean(fault->pfn); 46189aa8ab43SDavid Matlack return r; 46199aa8ab43SDavid Matlack } 46209aa8ab43SDavid Matlack #endif 46219aa8ab43SDavid Matlack 46221affe455SYan Zhao bool __kvm_mmu_honors_guest_mtrrs(bool vm_has_noncoherent_dma) 46231affe455SYan Zhao { 46241affe455SYan Zhao /* 46251affe455SYan Zhao * If host MTRRs are ignored (shadow_memtype_mask is non-zero), and the 46261affe455SYan Zhao * VM has non-coherent DMA (DMA doesn't snoop CPU caches), KVM's ABI is 46271affe455SYan Zhao * to honor the memtype from the guest's MTRRs so that guest accesses 46281affe455SYan Zhao * to memory that is DMA'd aren't cached against the guest's wishes. 46291affe455SYan Zhao * 46301affe455SYan Zhao * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 46311affe455SYan Zhao * e.g. KVM will force UC memtype for host MMIO. 46321affe455SYan Zhao */ 46331affe455SYan Zhao return vm_has_noncoherent_dma && shadow_memtype_mask; 46341affe455SYan Zhao } 46351affe455SYan Zhao 4636c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4637c50d8ae3SPaolo Bonzini { 4638d5e90a69SSean Christopherson /* 4639d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4640d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 46411affe455SYan Zhao * across the entire mapping. 4642d5e90a69SSean Christopherson */ 46431affe455SYan Zhao if (kvm_mmu_honors_guest_mtrrs(vcpu->kvm)) { 4644d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 46454326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 4646c667a3baSHou Wenlong gfn_t base = gfn_round_for_level(fault->gfn, 4647c667a3baSHou Wenlong fault->max_level); 4648c50d8ae3SPaolo Bonzini 4649cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4650cb9b88c6SSean Christopherson break; 4651d5e90a69SSean Christopherson } 4652c50d8ae3SPaolo Bonzini } 4653c50d8ae3SPaolo Bonzini 46549aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 46559aa8ab43SDavid Matlack if (tdp_mmu_enabled) 46569aa8ab43SDavid Matlack return kvm_tdp_mmu_page_fault(vcpu, fault); 46579aa8ab43SDavid Matlack #endif 46589aa8ab43SDavid Matlack 46594326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4660c50d8ae3SPaolo Bonzini } 4661c50d8ae3SPaolo Bonzini 466284a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4663c50d8ae3SPaolo Bonzini { 4664c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4665c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4666c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 4667c50d8ae3SPaolo Bonzini } 4668c50d8ae3SPaolo Bonzini 4669be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 46700be44352SSean Christopherson union kvm_mmu_page_role role) 46710be44352SSean Christopherson { 4672c30e000eSSean Christopherson struct kvm_mmu_page *sp; 4673c30e000eSSean Christopherson 4674c30e000eSSean Christopherson if (!VALID_PAGE(root->hpa)) 4675c30e000eSSean Christopherson return false; 4676c30e000eSSean Christopherson 4677c30e000eSSean Christopherson if (!role.direct && pgd != root->pgd) 4678c30e000eSSean Christopherson return false; 4679c30e000eSSean Christopherson 4680c30e000eSSean Christopherson sp = root_to_sp(root->hpa); 4681c30e000eSSean Christopherson if (WARN_ON_ONCE(!sp)) 4682c30e000eSSean Christopherson return false; 4683c30e000eSSean Christopherson 4684c30e000eSSean Christopherson return role.word == sp->role.word; 46850be44352SSean Christopherson } 46860be44352SSean Christopherson 4687c50d8ae3SPaolo Bonzini /* 46885499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 46895499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 46905499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 46915499ea73SPaolo Bonzini * true is returned. 46925499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 46935499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4694c50d8ae3SPaolo Bonzini */ 46955499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 46965499ea73SPaolo Bonzini gpa_t new_pgd, 4697c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4698c50d8ae3SPaolo Bonzini { 4699c50d8ae3SPaolo Bonzini uint i; 4700c50d8ae3SPaolo Bonzini 4701b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 47020be44352SSean Christopherson return true; 47030be44352SSean Christopherson 4704c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 47055499ea73SPaolo Bonzini /* 47065499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 47075499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 47085499ea73SPaolo Bonzini * 0 C 1 2 3 47095499ea73SPaolo Bonzini * 1 C 0 2 3 47105499ea73SPaolo Bonzini * 2 C 0 1 3 47115499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 47125499ea73SPaolo Bonzini */ 4713b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4714b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 47155499ea73SPaolo Bonzini return true; 4716c50d8ae3SPaolo Bonzini } 4717c50d8ae3SPaolo Bonzini 47185499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 47195499ea73SPaolo Bonzini return false; 4720c50d8ae3SPaolo Bonzini } 4721c50d8ae3SPaolo Bonzini 4722c50d8ae3SPaolo Bonzini /* 47235499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 47245499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 47255499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 47265499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 47275499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 47285499ea73SPaolo Bonzini */ 47295499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 47305499ea73SPaolo Bonzini gpa_t new_pgd, 47315499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 47325499ea73SPaolo Bonzini { 47335499ea73SPaolo Bonzini uint i; 47345499ea73SPaolo Bonzini 47355499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 47365499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 47375499ea73SPaolo Bonzini goto hit; 47385499ea73SPaolo Bonzini 47395499ea73SPaolo Bonzini return false; 47405499ea73SPaolo Bonzini 47415499ea73SPaolo Bonzini hit: 47425499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 47435499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 47445499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 47455499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 47465499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 47475499ea73SPaolo Bonzini return true; 47485499ea73SPaolo Bonzini } 47495499ea73SPaolo Bonzini 47505499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 47515499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 47525499ea73SPaolo Bonzini { 47535499ea73SPaolo Bonzini /* 47540e3223d8SSean Christopherson * Limit reuse to 64-bit hosts+VMs without "special" roots in order to 47550e3223d8SSean Christopherson * avoid having to deal with PDPTEs and other complexities. 4756c50d8ae3SPaolo Bonzini */ 4757c5f2d564SSean Christopherson if (VALID_PAGE(mmu->root.hpa) && !root_to_sp(mmu->root.hpa)) 47585499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4759c50d8ae3SPaolo Bonzini 47605499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 47615499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 47625499ea73SPaolo Bonzini else 47635499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4764c50d8ae3SPaolo Bonzini } 4765c50d8ae3SPaolo Bonzini 4766d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4767c50d8ae3SPaolo Bonzini { 47680c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 47697a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 47700c1c92f1SPaolo Bonzini 4771a7e48ef7SWei Liu /* 4772a7e48ef7SWei Liu * Return immediately if no usable root was found, kvm_mmu_reload() 4773a7e48ef7SWei Liu * will establish a valid root prior to the next VM-Enter. 4774a7e48ef7SWei Liu */ 4775a7e48ef7SWei Liu if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) 4776b869855bSSean Christopherson return; 4777c50d8ae3SPaolo Bonzini 4778c50d8ae3SPaolo Bonzini /* 4779b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4780b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4781527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4782527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4783b869855bSSean Christopherson */ 4784b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4785b869855bSSean Christopherson 4786b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4787b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4788b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4789b5129100SSean Christopherson } 4790b869855bSSean Christopherson 4791b869855bSSean Christopherson /* 4792b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4793b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4794b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4795b869855bSSean Christopherson * the shadow page tables. 4796c50d8ae3SPaolo Bonzini */ 4797c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4798c50d8ae3SPaolo Bonzini 4799daa5b6c1SBen Gardon /* 4800daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4801daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4802daa5b6c1SBen Gardon */ 4803c30e000eSSean Christopherson if (!new_role.direct) { 4804c30e000eSSean Christopherson struct kvm_mmu_page *sp = root_to_sp(vcpu->arch.mmu->root.hpa); 4805c30e000eSSean Christopherson 4806c30e000eSSean Christopherson if (!WARN_ON_ONCE(!sp)) 4807c30e000eSSean Christopherson __clear_sp_write_flooding_count(sp); 4808c30e000eSSean Christopherson } 4809c50d8ae3SPaolo Bonzini } 4810be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4811c50d8ae3SPaolo Bonzini 4812c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4813c3e5e415SLai Jiangshan unsigned int access) 4814c50d8ae3SPaolo Bonzini { 4815c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4816c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4817c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4818c50d8ae3SPaolo Bonzini return true; 4819c50d8ae3SPaolo Bonzini } 4820c50d8ae3SPaolo Bonzini 4821c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4822c50d8ae3SPaolo Bonzini return true; 4823c50d8ae3SPaolo Bonzini } 4824c50d8ae3SPaolo Bonzini 4825c50d8ae3SPaolo Bonzini return false; 4826c50d8ae3SPaolo Bonzini } 4827c50d8ae3SPaolo Bonzini 4828c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4829c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4830c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4831c50d8ae3SPaolo Bonzini #undef PTTYPE 4832c50d8ae3SPaolo Bonzini 4833c50d8ae3SPaolo Bonzini #define PTTYPE 64 4834c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4835c50d8ae3SPaolo Bonzini #undef PTTYPE 4836c50d8ae3SPaolo Bonzini 4837c50d8ae3SPaolo Bonzini #define PTTYPE 32 4838c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4839c50d8ae3SPaolo Bonzini #undef PTTYPE 4840c50d8ae3SPaolo Bonzini 4841f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 4842f3d90f90SSean Christopherson u64 pa_bits_rsvd, int level, bool nx, 4843f3d90f90SSean Christopherson bool gbpages, bool pse, bool amd) 4844c50d8ae3SPaolo Bonzini { 4845c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4846c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 48475b7f575cSSean Christopherson u64 high_bits_rsvd; 4848c50d8ae3SPaolo Bonzini 4849c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4850c50d8ae3SPaolo Bonzini 4851c50d8ae3SPaolo Bonzini if (!gbpages) 4852c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4853c50d8ae3SPaolo Bonzini 48545b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 48555b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 48565b7f575cSSean Christopherson else 48575b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 48585b7f575cSSean Christopherson 48595b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 48605b7f575cSSean Christopherson if (!nx) 48615b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 48625b7f575cSSean Christopherson 4863c50d8ae3SPaolo Bonzini /* 4864c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4865c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4866c50d8ae3SPaolo Bonzini */ 4867c50d8ae3SPaolo Bonzini if (amd) 4868c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4869c50d8ae3SPaolo Bonzini 4870c50d8ae3SPaolo Bonzini switch (level) { 4871c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4872c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4873c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4874c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4875c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4876c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4877c50d8ae3SPaolo Bonzini 4878c50d8ae3SPaolo Bonzini if (!pse) { 4879c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4880c50d8ae3SPaolo Bonzini break; 4881c50d8ae3SPaolo Bonzini } 4882c50d8ae3SPaolo Bonzini 4883c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4884c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4885c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4886c50d8ae3SPaolo Bonzini else 4887c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4888c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4889c50d8ae3SPaolo Bonzini break; 4890c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 48915b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 48925b7f575cSSean Christopherson high_bits_rsvd | 48935b7f575cSSean Christopherson rsvd_bits(5, 8) | 48945b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 48955b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 48965b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 48975b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4898c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4899c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4900c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4901c50d8ae3SPaolo Bonzini break; 4902c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 49035b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 49045b7f575cSSean Christopherson nonleaf_bit8_rsvd | 49055b7f575cSSean Christopherson rsvd_bits(7, 7); 4906c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4907c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4908df561f66SGustavo A. R. Silva fallthrough; 4909c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 49105b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 49115b7f575cSSean Christopherson nonleaf_bit8_rsvd | 49125b7f575cSSean Christopherson rsvd_bits(7, 7); 49135b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 49145b7f575cSSean Christopherson gbpages_bit_rsvd; 49155b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 49165b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4917c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4918c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 49195b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 49205b7f575cSSean Christopherson gbpages_bit_rsvd | 4921c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 49225b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4923c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4924c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4925c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4926c50d8ae3SPaolo Bonzini break; 4927c50d8ae3SPaolo Bonzini } 4928c50d8ae3SPaolo Bonzini } 4929c50d8ae3SPaolo Bonzini 4930c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4931c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4932c50d8ae3SPaolo Bonzini { 4933b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 49345b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 49354d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 4936ccf31d6eSSean Christopherson guest_can_use(vcpu, X86_FEATURE_GBPAGES), 49374e9c0d80SSean Christopherson is_cr4_pse(context), 493823493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4939c50d8ae3SPaolo Bonzini } 4940c50d8ae3SPaolo Bonzini 4941f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 4942f3d90f90SSean Christopherson u64 pa_bits_rsvd, bool execonly, 4943f3d90f90SSean Christopherson int huge_page_level) 4944c50d8ae3SPaolo Bonzini { 49455b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 494684ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4947c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4948c50d8ae3SPaolo Bonzini 494984ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 495084ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 495184ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 495284ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 495384ea5c09SLai Jiangshan 49545b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 49555b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 495684ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 495784ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 49585b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4959c50d8ae3SPaolo Bonzini 4960c50d8ae3SPaolo Bonzini /* large page */ 4961c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4962c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 496384ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 496484ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4965c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4966c50d8ae3SPaolo Bonzini 4967c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4968c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4969c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4970c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4971c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4972c50d8ae3SPaolo Bonzini if (!execonly) { 4973c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4974c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4975c50d8ae3SPaolo Bonzini } 4976c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4977c50d8ae3SPaolo Bonzini } 4978c50d8ae3SPaolo Bonzini 4979c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 498084ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4981c50d8ae3SPaolo Bonzini { 4982c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 498384ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 498484ea5c09SLai Jiangshan huge_page_level); 4985c50d8ae3SPaolo Bonzini } 4986c50d8ae3SPaolo Bonzini 49876f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 49886f8e65a6SSean Christopherson { 49896f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 49906f8e65a6SSean Christopherson } 49916f8e65a6SSean Christopherson 4992c50d8ae3SPaolo Bonzini /* 4993c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4994c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4995c50d8ae3SPaolo Bonzini * follow the features in guest. 4996c50d8ae3SPaolo Bonzini */ 499716be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 499816be1d12SSean Christopherson struct kvm_mmu *context) 4999c50d8ae3SPaolo Bonzini { 50008c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 50018c985b2dSSean Christopherson bool is_amd = true; 50028c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 50038c985b2dSSean Christopherson bool is_pse = false; 5004c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 5005c50d8ae3SPaolo Bonzini int i; 5006c50d8ae3SPaolo Bonzini 5007a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 50088c985b2dSSean Christopherson 5009c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 5010b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 5011a972e29cSPaolo Bonzini context->root_role.level, 50127a458f0eSPaolo Bonzini context->root_role.efer_nx, 5013ccf31d6eSSean Christopherson guest_can_use(vcpu, X86_FEATURE_GBPAGES), 5014ccf31d6eSSean Christopherson is_pse, is_amd); 5015c50d8ae3SPaolo Bonzini 5016c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 5017c50d8ae3SPaolo Bonzini return; 5018c50d8ae3SPaolo Bonzini 5019a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 5020e54f1ff2SKai Huang /* 5021e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 5022e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 5023e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 5024e54f1ff2SKai Huang * not allowed to be set. 5025e54f1ff2SKai Huang */ 5026e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 5027e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 5028e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 5029e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 5030c50d8ae3SPaolo Bonzini } 5031c50d8ae3SPaolo Bonzini 5032c50d8ae3SPaolo Bonzini } 5033c50d8ae3SPaolo Bonzini 5034c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 5035c50d8ae3SPaolo Bonzini { 5036c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 5037c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 5038c50d8ae3SPaolo Bonzini } 5039c50d8ae3SPaolo Bonzini 5040c50d8ae3SPaolo Bonzini /* 5041c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 5042c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 5043c50d8ae3SPaolo Bonzini */ 5044f3d90f90SSean Christopherson static void reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 5045c50d8ae3SPaolo Bonzini { 5046c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 5047c50d8ae3SPaolo Bonzini int i; 5048c50d8ae3SPaolo Bonzini 5049c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 5050c50d8ae3SPaolo Bonzini 5051c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 5052b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 50536c6ab524SSean Christopherson context->root_role.level, true, 5054c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 50558c985b2dSSean Christopherson false, true); 5056c50d8ae3SPaolo Bonzini else 5057c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 505884ea5c09SLai Jiangshan reserved_hpa_bits(), false, 505984ea5c09SLai Jiangshan max_huge_page_level); 5060c50d8ae3SPaolo Bonzini 5061c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 5062c50d8ae3SPaolo Bonzini return; 5063c50d8ae3SPaolo Bonzini 5064a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 5065c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 5066c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 5067c50d8ae3SPaolo Bonzini } 5068c50d8ae3SPaolo Bonzini } 5069c50d8ae3SPaolo Bonzini 5070c50d8ae3SPaolo Bonzini /* 5071c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 5072c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 5073c50d8ae3SPaolo Bonzini */ 5074c50d8ae3SPaolo Bonzini static void 5075e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 5076c50d8ae3SPaolo Bonzini { 5077c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 507884ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 507984ea5c09SLai Jiangshan max_huge_page_level); 5080c50d8ae3SPaolo Bonzini } 5081c50d8ae3SPaolo Bonzini 5082c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 5083c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 5084c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 5085c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 5086c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 5087c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 5088c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 5089c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 5090c50d8ae3SPaolo Bonzini 5091c50d8ae3SPaolo Bonzini 5092c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 5093c50d8ae3SPaolo Bonzini { 5094c50d8ae3SPaolo Bonzini unsigned byte; 5095c50d8ae3SPaolo Bonzini 5096c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 5097c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 5098c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 5099c50d8ae3SPaolo Bonzini 5100c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 5101c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 5102c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 510390599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 5104c50d8ae3SPaolo Bonzini 5105c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 5106c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 5107c50d8ae3SPaolo Bonzini 5108c50d8ae3SPaolo Bonzini /* 5109c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 5110c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 5111c50d8ae3SPaolo Bonzini */ 5112c50d8ae3SPaolo Bonzini 5113c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 5114c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 5115c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 5116c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 5117c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 5118c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 5119c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 5120c50d8ae3SPaolo Bonzini u8 smepf = 0; 5121c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 5122c50d8ae3SPaolo Bonzini u8 smapf = 0; 5123c50d8ae3SPaolo Bonzini 5124c50d8ae3SPaolo Bonzini if (!ept) { 5125c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 5126c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 5127c50d8ae3SPaolo Bonzini 5128c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 512990599c28SSean Christopherson if (!efer_nx) 5130c50d8ae3SPaolo Bonzini ff = 0; 5131c50d8ae3SPaolo Bonzini 5132c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 5133c50d8ae3SPaolo Bonzini if (!cr0_wp) 5134c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 5135c50d8ae3SPaolo Bonzini 5136c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 5137c50d8ae3SPaolo Bonzini if (cr4_smep) 5138c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 5139c50d8ae3SPaolo Bonzini 5140c50d8ae3SPaolo Bonzini /* 5141c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 5142c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 5143c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 5144c50d8ae3SPaolo Bonzini * conditions are true: 5145c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 5146c50d8ae3SPaolo Bonzini * - A user page is accessed 5147c50d8ae3SPaolo Bonzini * - The access is not a fetch 51484f4aa80eSLai Jiangshan * - The access is supervisor mode 51494f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 5150c50d8ae3SPaolo Bonzini * 515194b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 515294b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 5153c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 5154c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 5155c50d8ae3SPaolo Bonzini */ 5156c50d8ae3SPaolo Bonzini if (cr4_smap) 5157c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 5158c50d8ae3SPaolo Bonzini } 5159c50d8ae3SPaolo Bonzini 5160c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 5161c50d8ae3SPaolo Bonzini } 5162c50d8ae3SPaolo Bonzini } 5163c50d8ae3SPaolo Bonzini 5164c50d8ae3SPaolo Bonzini /* 5165c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 5166c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 5167c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 5168c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 5169c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 5170c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 5171c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 5172c50d8ae3SPaolo Bonzini * 5173c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 5174c50d8ae3SPaolo Bonzini * page tables and the machine state: 5175c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 5176c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 5177c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 5178c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 5179c50d8ae3SPaolo Bonzini * 5180c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 5181c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 5182c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 5183c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 5184c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 5185c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 5186c50d8ae3SPaolo Bonzini * only will be masked away. 5187c50d8ae3SPaolo Bonzini */ 51882e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 5189c50d8ae3SPaolo Bonzini { 5190c50d8ae3SPaolo Bonzini unsigned bit; 5191c50d8ae3SPaolo Bonzini bool wp; 5192c50d8ae3SPaolo Bonzini 5193c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 5194a3ca5281SChenyi Qiang 5195a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 5196c50d8ae3SPaolo Bonzini return; 5197c50d8ae3SPaolo Bonzini 51982e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 5199c50d8ae3SPaolo Bonzini 5200c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 5201c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 5202c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 5203c50d8ae3SPaolo Bonzini 5204c50d8ae3SPaolo Bonzini pfec = bit << 1; 5205c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 5206c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 5207c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 5208c50d8ae3SPaolo Bonzini 5209c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 5210c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 5211c50d8ae3SPaolo Bonzini 5212c50d8ae3SPaolo Bonzini /* 5213c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 5214c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 5215c50d8ae3SPaolo Bonzini */ 5216c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 5217c50d8ae3SPaolo Bonzini /* 5218c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 5219c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 5220c50d8ae3SPaolo Bonzini */ 5221c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 5222c50d8ae3SPaolo Bonzini 5223c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 5224c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 5225c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 5226c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 5227c50d8ae3SPaolo Bonzini 5228c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 5229c50d8ae3SPaolo Bonzini } 5230c50d8ae3SPaolo Bonzini } 5231c50d8ae3SPaolo Bonzini 5232533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 5233533f9a4bSSean Christopherson struct kvm_mmu *mmu) 5234c50d8ae3SPaolo Bonzini { 5235533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 5236533f9a4bSSean Christopherson return; 5237c50d8ae3SPaolo Bonzini 5238c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 5239533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 5240533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 5241c50d8ae3SPaolo Bonzini } 5242c50d8ae3SPaolo Bonzini 5243fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 5244c50d8ae3SPaolo Bonzini { 5245c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 5246c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5247c3c6c9fcSLai Jiangshan context->sync_spte = paging64_sync_spte; 5248c50d8ae3SPaolo Bonzini } 5249c50d8ae3SPaolo Bonzini 525084a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 5251c50d8ae3SPaolo Bonzini { 5252c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 5253c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5254c3c6c9fcSLai Jiangshan context->sync_spte = paging32_sync_spte; 5255c50d8ae3SPaolo Bonzini } 5256c50d8ae3SPaolo Bonzini 5257f3d90f90SSean Christopherson static union kvm_cpu_role kvm_calc_cpu_role(struct kvm_vcpu *vcpu, 5258f3d90f90SSean Christopherson const struct kvm_mmu_role_regs *regs) 5259e5ed0fb0SPaolo Bonzini { 52607a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5261e5ed0fb0SPaolo Bonzini 5262e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 5263e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 5264e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 5265e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 5266e5ed0fb0SPaolo Bonzini 5267e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 5268e5ed0fb0SPaolo Bonzini role.base.direct = 1; 5269e5ed0fb0SPaolo Bonzini return role; 5270e5ed0fb0SPaolo Bonzini } 5271e5ed0fb0SPaolo Bonzini 5272e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 5273e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 5274e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 5275e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 5276e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 527760f3cb60SPaolo Bonzini 527860f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 527960f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 528060f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 528160f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 528260f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 528360f3cb60SPaolo Bonzini else 528460f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 5285e5ed0fb0SPaolo Bonzini 5286e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 5287e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 5288e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 5289e5ed0fb0SPaolo Bonzini 5290e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 5291e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 5292e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 5293e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 5294e5ed0fb0SPaolo Bonzini return role; 5295e5ed0fb0SPaolo Bonzini } 5296e5ed0fb0SPaolo Bonzini 5297cf9f4c0eSSean Christopherson void __kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu, 5298cf9f4c0eSSean Christopherson struct kvm_mmu *mmu) 5299cf9f4c0eSSean Christopherson { 5300cf9f4c0eSSean Christopherson const bool cr0_wp = kvm_is_cr0_bit_set(vcpu, X86_CR0_WP); 5301cf9f4c0eSSean Christopherson 5302cf9f4c0eSSean Christopherson BUILD_BUG_ON((KVM_MMU_CR0_ROLE_BITS & KVM_POSSIBLE_CR0_GUEST_BITS) != X86_CR0_WP); 5303cf9f4c0eSSean Christopherson BUILD_BUG_ON((KVM_MMU_CR4_ROLE_BITS & KVM_POSSIBLE_CR4_GUEST_BITS)); 5304cf9f4c0eSSean Christopherson 5305cf9f4c0eSSean Christopherson if (is_cr0_wp(mmu) == cr0_wp) 5306cf9f4c0eSSean Christopherson return; 5307cf9f4c0eSSean Christopherson 5308cf9f4c0eSSean Christopherson mmu->cpu_role.base.cr0_wp = cr0_wp; 5309cf9f4c0eSSean Christopherson reset_guest_paging_metadata(vcpu, mmu); 5310cf9f4c0eSSean Christopherson } 5311cf9f4c0eSSean Christopherson 5312d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 5313d468d94bSSean Christopherson { 5314746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5315746700d2SWei Huang if (tdp_root_level) 5316746700d2SWei Huang return tdp_root_level; 5317746700d2SWei Huang 5318d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 531983013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5320d468d94bSSean Christopherson return 4; 5321d468d94bSSean Christopherson 532283013059SSean Christopherson return max_tdp_level; 5323d468d94bSSean Christopherson } 5324d468d94bSSean Christopherson 5325*b628cb52SGerd Hoffmann u8 kvm_mmu_get_max_tdp_level(void) 5326*b628cb52SGerd Hoffmann { 5327*b628cb52SGerd Hoffmann return tdp_root_level ? tdp_root_level : max_tdp_level; 5328*b628cb52SGerd Hoffmann } 5329*b628cb52SGerd Hoffmann 53307a458f0eSPaolo Bonzini static union kvm_mmu_page_role 53318626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 53327a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5333c50d8ae3SPaolo Bonzini { 53347a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5335c50d8ae3SPaolo Bonzini 53367a458f0eSPaolo Bonzini role.access = ACC_ALL; 53377a458f0eSPaolo Bonzini role.cr0_wp = true; 53387a458f0eSPaolo Bonzini role.efer_nx = true; 53397a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 53407a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 534154275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 53427a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 53437a458f0eSPaolo Bonzini role.direct = true; 53447a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5345c50d8ae3SPaolo Bonzini 5346c50d8ae3SPaolo Bonzini return role; 5347c50d8ae3SPaolo Bonzini } 5348c50d8ae3SPaolo Bonzini 534939e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5350a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5351c50d8ae3SPaolo Bonzini { 53528c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 53537a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5354c50d8ae3SPaolo Bonzini 5355e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 53567a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5357c50d8ae3SPaolo Bonzini return; 5358c50d8ae3SPaolo Bonzini 5359e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 53607a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 53617a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5362c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 53632fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5364c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5365c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5366c50d8ae3SPaolo Bonzini 536736f26787SSean Christopherson if (!is_cr0_pg(context)) 5368c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 536936f26787SSean Christopherson else if (is_cr4_pae(context)) 5370c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5371f4bd6f73SSean Christopherson else 5372c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5373c50d8ae3SPaolo Bonzini 5374533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5375e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5376c50d8ae3SPaolo Bonzini } 5377c50d8ae3SPaolo Bonzini 53788c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 53797a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 53807a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5381c50d8ae3SPaolo Bonzini { 5382e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 53837a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 538418db1b17SSean Christopherson return; 5385c50d8ae3SPaolo Bonzini 5386e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 53877a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 538818db1b17SSean Christopherson 538936f26787SSean Christopherson if (!is_cr0_pg(context)) 539084a16226SSean Christopherson nonpaging_init_context(context); 539136f26787SSean Christopherson else if (is_cr4_pae(context)) 5392fe660f72SSean Christopherson paging64_init_context(context); 5393c50d8ae3SPaolo Bonzini else 539484a16226SSean Christopherson paging32_init_context(context); 5395c50d8ae3SPaolo Bonzini 5396533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5397c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5398c50d8ae3SPaolo Bonzini } 53990f04a2acSVitaly Kuznetsov 5400594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5401a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 54020f04a2acSVitaly Kuznetsov { 54038c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 540456b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 540556b321f9SPaolo Bonzini 540656b321f9SPaolo Bonzini root_role = cpu_role.base; 540756b321f9SPaolo Bonzini 540856b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 540956b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 541056b321f9SPaolo Bonzini 541156b321f9SPaolo Bonzini /* 541256b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 541356b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 541456b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 541556b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 541656b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 541756b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 541856b321f9SPaolo Bonzini * MMU contexts. 541956b321f9SPaolo Bonzini */ 542056b321f9SPaolo Bonzini root_role.efer_nx = true; 54210f04a2acSVitaly Kuznetsov 54227a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 54230f04a2acSVitaly Kuznetsov } 54240f04a2acSVitaly Kuznetsov 5425dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5426dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 54270f04a2acSVitaly Kuznetsov { 54288c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5429594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5430594e91a1SSean Christopherson .cr0 = cr0, 543128f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5432594e91a1SSean Christopherson .efer = efer, 5433594e91a1SSean Christopherson }; 54347a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 543556b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 543656b321f9SPaolo Bonzini 543756b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 543856b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 543956b321f9SPaolo Bonzini 544056b321f9SPaolo Bonzini root_role = cpu_role.base; 544156b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 544284e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 544384e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 544484e5ffd0SLai Jiangshan root_role.passthrough = 1; 54450f04a2acSVitaly Kuznetsov 54467a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5447d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 54480f04a2acSVitaly Kuznetsov } 54490f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5450c50d8ae3SPaolo Bonzini 54517a7ae829SPaolo Bonzini static union kvm_cpu_role 5452c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5453bb1fcc70SSean Christopherson bool execonly, u8 level) 5454c50d8ae3SPaolo Bonzini { 54557a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5456c50d8ae3SPaolo Bonzini 5457daed87b8SPaolo Bonzini /* 5458daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5459daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5460daed87b8SPaolo Bonzini */ 5461daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5462bb1fcc70SSean Christopherson role.base.level = level; 5463bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5464c50d8ae3SPaolo Bonzini role.base.direct = false; 5465c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5466c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5467c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5468c50d8ae3SPaolo Bonzini 5469cd6767c3SSean Christopherson role.ext.word = 0; 5470c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5471cd6767c3SSean Christopherson role.ext.valid = 1; 5472c50d8ae3SPaolo Bonzini 5473c50d8ae3SPaolo Bonzini return role; 5474c50d8ae3SPaolo Bonzini } 5475c50d8ae3SPaolo Bonzini 5476c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5477cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5478cc022ae1SLai Jiangshan gpa_t new_eptp) 5479c50d8ae3SPaolo Bonzini { 54808c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5481bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 54827a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5483c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5484bb1fcc70SSean Christopherson execonly, level); 5485c50d8ae3SPaolo Bonzini 5486e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5487e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5488e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 54897a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 549018db1b17SSean Christopherson 5491c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5492c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5493c3c6c9fcSLai Jiangshan context->sync_spte = ept_sync_spte; 5494347a0d0dSPaolo Bonzini 5495c596f147SSean Christopherson update_permission_bitmask(context, true); 549628f091bcSPaolo Bonzini context->pkru_mask = 0; 5497cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5498e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5499c50d8ae3SPaolo Bonzini } 55003cffc89dSPaolo Bonzini 5501d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 55023cffc89dSPaolo Bonzini } 5503c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5504c50d8ae3SPaolo Bonzini 550539e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5506a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5507c50d8ae3SPaolo Bonzini { 55088c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5509c50d8ae3SPaolo Bonzini 5510a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5511929d1cfaSPaolo Bonzini 55122fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5513c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5514c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5515c50d8ae3SPaolo Bonzini } 5516c50d8ae3SPaolo Bonzini 551739e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5518a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5519c50d8ae3SPaolo Bonzini { 5520c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5521c50d8ae3SPaolo Bonzini 5522e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5523c50d8ae3SPaolo Bonzini return; 5524c50d8ae3SPaolo Bonzini 5525e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 55262fdcc1b3SPaolo Bonzini g_context->get_guest_pgd = get_guest_cr3; 5527c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5528c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5529c50d8ae3SPaolo Bonzini 5530c50d8ae3SPaolo Bonzini /* 55315efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 55325efac074SPaolo Bonzini * SPTEs. 55335efac074SPaolo Bonzini */ 55349fd4a4e3SLai Jiangshan g_context->sync_spte = NULL; 55355efac074SPaolo Bonzini 55365efac074SPaolo Bonzini /* 5537c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5538c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5539c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5540c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5541c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5542c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5543c50d8ae3SPaolo Bonzini */ 5544fa4b5588SSean Christopherson if (!is_paging(vcpu)) 55451f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5546fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 55471f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5548fa4b5588SSean Christopherson else if (is_pae(vcpu)) 55491f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5550fa4b5588SSean Christopherson else 55511f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5552fa4b5588SSean Christopherson 5553533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5554c50d8ae3SPaolo Bonzini } 5555c50d8ae3SPaolo Bonzini 5556c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5557c50d8ae3SPaolo Bonzini { 555839e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5559a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 556039e7e2bfSPaolo Bonzini 5561c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5562a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5563c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5564a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5565c50d8ae3SPaolo Bonzini else 5566a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5567c50d8ae3SPaolo Bonzini } 5568c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5569c50d8ae3SPaolo Bonzini 557049c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 557149c6f875SSean Christopherson { 557249c6f875SSean Christopherson /* 557349c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 557449c6f875SSean Christopherson * information is factored into reserved bit calculations. 5575feb627e8SVitaly Kuznetsov * 5576feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5577feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5578feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5579feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5580338068b5SSean Christopherson * gfn_write_track (see struct kvm_mmu_page_role comments). For now 5581338068b5SSean Christopherson * that problem is swept under the rug; KVM's CPUID API is horrific and 5582feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 558349c6f875SSean Christopherson */ 55847a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 55857a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 55867a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5587e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5588e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5589e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 559049c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 559163f5a190SSean Christopherson 559263f5a190SSean Christopherson /* 5593feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5594feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 559563f5a190SSean Christopherson */ 5596fb3146b4SSean Christopherson KVM_BUG_ON(kvm_vcpu_has_run(vcpu), vcpu->kvm); 559749c6f875SSean Christopherson } 559849c6f875SSean Christopherson 5599c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5600c50d8ae3SPaolo Bonzini { 5601c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5602c9060662SSean Christopherson kvm_init_mmu(vcpu); 5603c50d8ae3SPaolo Bonzini } 5604c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5605c50d8ae3SPaolo Bonzini 5606c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5607c50d8ae3SPaolo Bonzini { 5608c50d8ae3SPaolo Bonzini int r; 5609c50d8ae3SPaolo Bonzini 5610347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5611c50d8ae3SPaolo Bonzini if (r) 5612c50d8ae3SPaolo Bonzini goto out; 5613748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5614c50d8ae3SPaolo Bonzini if (r) 5615c50d8ae3SPaolo Bonzini goto out; 5616347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 56176e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 56186e6ec584SSean Christopherson else 56196e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5620c50d8ae3SPaolo Bonzini if (r) 5621c50d8ae3SPaolo Bonzini goto out; 5622a91f387bSSean Christopherson 5623a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5624a91f387bSSean Christopherson 5625727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5626db01416bSSean Christopherson 5627db01416bSSean Christopherson /* 5628db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5629db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5630db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5631db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5632db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5633db01416bSSean Christopherson */ 5634e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5635c50d8ae3SPaolo Bonzini out: 5636c50d8ae3SPaolo Bonzini return r; 5637c50d8ae3SPaolo Bonzini } 5638c50d8ae3SPaolo Bonzini 5639c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5640c50d8ae3SPaolo Bonzini { 56410c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 56420c1c92f1SPaolo Bonzini 56430c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 564420ba462dSSean Christopherson WARN_ON_ONCE(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 56450c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 564620ba462dSSean Christopherson WARN_ON_ONCE(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 56476d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5648c50d8ae3SPaolo Bonzini } 5649c50d8ae3SPaolo Bonzini 5650527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5651527d5cd7SSean Christopherson { 5652527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5653527d5cd7SSean Christopherson 5654527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5655527d5cd7SSean Christopherson return false; 5656527d5cd7SSean Christopherson 5657527d5cd7SSean Christopherson /* 5658527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 56590e3223d8SSean Christopherson * have an associated shadow page, as it's impossible to determine if 56600e3223d8SSean Christopherson * such roots are fresh or stale. This does mean KVM will get false 5661527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5662527d5cd7SSean Christopherson * such false positives are relatively rare: 5663527d5cd7SSean Christopherson * 56640e3223d8SSean Christopherson * (a) only PAE paging and nested NPT have roots without shadow pages 56650e3223d8SSean Christopherson * (or any shadow paging flavor with a dummy root, see note below) 5666527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5667527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5668527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 56690e3223d8SSean Christopherson * 56700e3223d8SSean Christopherson * Note! Dummy roots are unique in that they are obsoleted by memslot 56710e3223d8SSean Christopherson * _creation_! See also FNAME(fetch). 5672527d5cd7SSean Christopherson */ 5673c5f2d564SSean Christopherson sp = root_to_sp(root_hpa); 5674527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5675527d5cd7SSean Christopherson } 5676527d5cd7SSean Christopherson 5677527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5678527d5cd7SSean Christopherson { 5679527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5680527d5cd7SSean Christopherson int i; 5681527d5cd7SSean Christopherson 5682527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5683527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5684527d5cd7SSean Christopherson 5685527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5686cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5687527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5688527d5cd7SSean Christopherson } 5689527d5cd7SSean Christopherson 5690527d5cd7SSean Christopherson if (roots_to_free) 5691527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5692527d5cd7SSean Christopherson } 5693527d5cd7SSean Christopherson 5694527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5695527d5cd7SSean Christopherson { 5696527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5697527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5698527d5cd7SSean Christopherson } 5699527d5cd7SSean Christopherson 5700c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5701c50d8ae3SPaolo Bonzini int *bytes) 5702c50d8ae3SPaolo Bonzini { 5703c50d8ae3SPaolo Bonzini u64 gentry = 0; 5704c50d8ae3SPaolo Bonzini int r; 5705c50d8ae3SPaolo Bonzini 5706c50d8ae3SPaolo Bonzini /* 5707c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5708c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5709c50d8ae3SPaolo Bonzini * when they have the same mode. 5710c50d8ae3SPaolo Bonzini */ 5711c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5712c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5713c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5714c50d8ae3SPaolo Bonzini *bytes = 8; 5715c50d8ae3SPaolo Bonzini } 5716c50d8ae3SPaolo Bonzini 5717c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5718c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5719c50d8ae3SPaolo Bonzini if (r) 5720c50d8ae3SPaolo Bonzini gentry = 0; 5721c50d8ae3SPaolo Bonzini } 5722c50d8ae3SPaolo Bonzini 5723c50d8ae3SPaolo Bonzini return gentry; 5724c50d8ae3SPaolo Bonzini } 5725c50d8ae3SPaolo Bonzini 5726c50d8ae3SPaolo Bonzini /* 5727c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5728c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5729c50d8ae3SPaolo Bonzini */ 5730c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5731c50d8ae3SPaolo Bonzini { 5732c50d8ae3SPaolo Bonzini /* 5733c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5734c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5735c50d8ae3SPaolo Bonzini */ 57363bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5737c50d8ae3SPaolo Bonzini return false; 5738c50d8ae3SPaolo Bonzini 5739c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5740c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5741c50d8ae3SPaolo Bonzini } 5742c50d8ae3SPaolo Bonzini 5743c50d8ae3SPaolo Bonzini /* 5744c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5745c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5746c50d8ae3SPaolo Bonzini */ 5747c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5748c50d8ae3SPaolo Bonzini int bytes) 5749c50d8ae3SPaolo Bonzini { 5750c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5751c50d8ae3SPaolo Bonzini 5752c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5753bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5754c50d8ae3SPaolo Bonzini 5755c50d8ae3SPaolo Bonzini /* 5756c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5757c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5758c50d8ae3SPaolo Bonzini */ 5759c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5760c50d8ae3SPaolo Bonzini return false; 5761c50d8ae3SPaolo Bonzini 5762c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5763c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5764c50d8ae3SPaolo Bonzini 5765c50d8ae3SPaolo Bonzini return misaligned; 5766c50d8ae3SPaolo Bonzini } 5767c50d8ae3SPaolo Bonzini 5768c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5769c50d8ae3SPaolo Bonzini { 5770c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5771c50d8ae3SPaolo Bonzini u64 *spte; 5772c50d8ae3SPaolo Bonzini int level; 5773c50d8ae3SPaolo Bonzini 5774c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5775c50d8ae3SPaolo Bonzini level = sp->role.level; 5776c50d8ae3SPaolo Bonzini *nspte = 1; 5777bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5778c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5779c50d8ae3SPaolo Bonzini /* 5780c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5781c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5782c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5783c50d8ae3SPaolo Bonzini */ 5784c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5785c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5786c50d8ae3SPaolo Bonzini page_offset <<= 1; 5787c50d8ae3SPaolo Bonzini *nspte = 2; 5788c50d8ae3SPaolo Bonzini } 5789c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5790c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5791c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5792c50d8ae3SPaolo Bonzini return NULL; 5793c50d8ae3SPaolo Bonzini } 5794c50d8ae3SPaolo Bonzini 5795c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5796c50d8ae3SPaolo Bonzini return spte; 5797c50d8ae3SPaolo Bonzini } 5798c50d8ae3SPaolo Bonzini 579993284446SSean Christopherson void kvm_mmu_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, 580093284446SSean Christopherson int bytes) 5801c50d8ae3SPaolo Bonzini { 5802c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5803c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5804c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5805c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5806c50d8ae3SPaolo Bonzini int npte; 580706152b2dSLai Jiangshan bool flush = false; 5808c50d8ae3SPaolo Bonzini 5809c50d8ae3SPaolo Bonzini /* 5810c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5811c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5812c50d8ae3SPaolo Bonzini */ 5813c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5814c50d8ae3SPaolo Bonzini return; 5815c50d8ae3SPaolo Bonzini 5816531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5817c50d8ae3SPaolo Bonzini 5818c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5819c50d8ae3SPaolo Bonzini 5820c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5821c50d8ae3SPaolo Bonzini 5822767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5823c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5824c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5825c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5826c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5827c50d8ae3SPaolo Bonzini continue; 5828c50d8ae3SPaolo Bonzini } 5829c50d8ae3SPaolo Bonzini 5830c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5831c50d8ae3SPaolo Bonzini if (!spte) 5832c50d8ae3SPaolo Bonzini continue; 5833c50d8ae3SPaolo Bonzini 5834c50d8ae3SPaolo Bonzini while (npte--) { 5835c50d8ae3SPaolo Bonzini entry = *spte; 58362de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5837c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5838c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 58391441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 584006152b2dSLai Jiangshan flush = true; 5841c50d8ae3SPaolo Bonzini ++spte; 5842c50d8ae3SPaolo Bonzini } 5843c50d8ae3SPaolo Bonzini } 584406152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5845531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5846c50d8ae3SPaolo Bonzini } 5847c50d8ae3SPaolo Bonzini 58481075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5849c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5850c50d8ae3SPaolo Bonzini { 585192daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5852347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5853c50d8ae3SPaolo Bonzini 5854d09f7112SSean Christopherson /* 5855d09f7112SSean Christopherson * IMPLICIT_ACCESS is a KVM-defined flag used to correctly perform SMAP 5856d09f7112SSean Christopherson * checks when emulating instructions that triggers implicit access. 5857d09f7112SSean Christopherson * WARN if hardware generates a fault with an error code that collides 5858d09f7112SSean Christopherson * with the KVM-defined value. Clear the flag and continue on, i.e. 5859d09f7112SSean Christopherson * don't terminate the VM, as KVM can't possibly be relying on a flag 5860d09f7112SSean Christopherson * that KVM doesn't know about. 5861d09f7112SSean Christopherson */ 5862d09f7112SSean Christopherson if (WARN_ON_ONCE(error_code & PFERR_IMPLICIT_ACCESS)) 5863d09f7112SSean Christopherson error_code &= ~PFERR_IMPLICIT_ACCESS; 5864d09f7112SSean Christopherson 586520ba462dSSean Christopherson if (WARN_ON_ONCE(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5866ddce6208SSean Christopherson return RET_PF_RETRY; 5867ddce6208SSean Christopherson 5868c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5869c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5870736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5871c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5872c50d8ae3SPaolo Bonzini goto emulate; 5873c50d8ae3SPaolo Bonzini } 5874c50d8ae3SPaolo Bonzini 5875c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 58767a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 5877258d985fSSean Christopherson lower_32_bits(error_code), false, 5878258d985fSSean Christopherson &emulation_type); 587919025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 58807b367bc9SSean Christopherson return -EIO; 5881c50d8ae3SPaolo Bonzini } 5882c50d8ae3SPaolo Bonzini 5883c50d8ae3SPaolo Bonzini if (r < 0) 5884c50d8ae3SPaolo Bonzini return r; 588583a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 588683a2ba4cSSean Christopherson return 1; 5887c50d8ae3SPaolo Bonzini 5888c50d8ae3SPaolo Bonzini /* 5889c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5890c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5891c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5892c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5893c50d8ae3SPaolo Bonzini * and resume the guest. 5894c50d8ae3SPaolo Bonzini */ 5895347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5896c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5897736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5898c50d8ae3SPaolo Bonzini return 1; 5899c50d8ae3SPaolo Bonzini } 5900c50d8ae3SPaolo Bonzini 5901c50d8ae3SPaolo Bonzini /* 5902c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5903c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5904c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5905c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5906c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5907c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5908c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5909c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5910c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5911c50d8ae3SPaolo Bonzini */ 5912736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 591392daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5914c50d8ae3SPaolo Bonzini emulate: 5915736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5916c50d8ae3SPaolo Bonzini insn_len); 5917c50d8ae3SPaolo Bonzini } 5918c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5919c50d8ae3SPaolo Bonzini 59209fd4a4e3SLai Jiangshan static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 59219fd4a4e3SLai Jiangshan u64 addr, hpa_t root_hpa) 59229fd4a4e3SLai Jiangshan { 59239fd4a4e3SLai Jiangshan struct kvm_shadow_walk_iterator iterator; 59249fd4a4e3SLai Jiangshan 59259fd4a4e3SLai Jiangshan vcpu_clear_mmio_info(vcpu, addr); 59269fd4a4e3SLai Jiangshan 5927762b33ebSLike Xu /* 5928762b33ebSLike Xu * Walking and synchronizing SPTEs both assume they are operating in 5929762b33ebSLike Xu * the context of the current MMU, and would need to be reworked if 5930762b33ebSLike Xu * this is ever used to sync the guest_mmu, e.g. to emulate INVEPT. 5931762b33ebSLike Xu */ 5932762b33ebSLike Xu if (WARN_ON_ONCE(mmu != vcpu->arch.mmu)) 5933762b33ebSLike Xu return; 5934762b33ebSLike Xu 59359fd4a4e3SLai Jiangshan if (!VALID_PAGE(root_hpa)) 59369fd4a4e3SLai Jiangshan return; 59379fd4a4e3SLai Jiangshan 59389fd4a4e3SLai Jiangshan write_lock(&vcpu->kvm->mmu_lock); 59399fd4a4e3SLai Jiangshan for_each_shadow_entry_using_root(vcpu, root_hpa, addr, iterator) { 59409fd4a4e3SLai Jiangshan struct kvm_mmu_page *sp = sptep_to_sp(iterator.sptep); 59419fd4a4e3SLai Jiangshan 59429fd4a4e3SLai Jiangshan if (sp->unsync) { 594319ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, iterator.index); 59449fd4a4e3SLai Jiangshan 59459fd4a4e3SLai Jiangshan if (ret < 0) 59469fd4a4e3SLai Jiangshan mmu_page_zap_pte(vcpu->kvm, sp, iterator.sptep, NULL); 59479fd4a4e3SLai Jiangshan if (ret) 59489fd4a4e3SLai Jiangshan kvm_flush_remote_tlbs_sptep(vcpu->kvm, iterator.sptep); 59499fd4a4e3SLai Jiangshan } 59509fd4a4e3SLai Jiangshan 59519fd4a4e3SLai Jiangshan if (!sp->unsync_children) 59529fd4a4e3SLai Jiangshan break; 59539fd4a4e3SLai Jiangshan } 59549fd4a4e3SLai Jiangshan write_unlock(&vcpu->kvm->mmu_lock); 59559fd4a4e3SLai Jiangshan } 59569fd4a4e3SLai Jiangshan 5957753b43c9SLai Jiangshan void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 5958cd42853eSLai Jiangshan u64 addr, unsigned long roots) 5959c50d8ae3SPaolo Bonzini { 5960c50d8ae3SPaolo Bonzini int i; 5961c50d8ae3SPaolo Bonzini 5962cd42853eSLai Jiangshan WARN_ON_ONCE(roots & ~KVM_MMU_ROOTS_ALL); 5963cd42853eSLai Jiangshan 59645efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 59655efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 59665efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5967753b43c9SLai Jiangshan if (is_noncanonical_address(addr, vcpu)) 5968c50d8ae3SPaolo Bonzini return; 5969c50d8ae3SPaolo Bonzini 5970753b43c9SLai Jiangshan static_call(kvm_x86_flush_tlb_gva)(vcpu, addr); 59715efac074SPaolo Bonzini } 59725efac074SPaolo Bonzini 59739fd4a4e3SLai Jiangshan if (!mmu->sync_spte) 59745efac074SPaolo Bonzini return; 59755efac074SPaolo Bonzini 5976cd42853eSLai Jiangshan if (roots & KVM_MMU_ROOT_CURRENT) 59779fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->root.hpa); 5978c50d8ae3SPaolo Bonzini 5979cd42853eSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5980ed335278SLai Jiangshan if (roots & KVM_MMU_ROOT_PREVIOUS(i)) 59819fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->prev_roots[i].hpa); 59825efac074SPaolo Bonzini } 59835efac074SPaolo Bonzini } 59842c86c444SLai Jiangshan EXPORT_SYMBOL_GPL(kvm_mmu_invalidate_addr); 5985c50d8ae3SPaolo Bonzini 59865efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 59875efac074SPaolo Bonzini { 5988cd42853eSLai Jiangshan /* 5989cd42853eSLai Jiangshan * INVLPG is required to invalidate any global mappings for the VA, 5990cd42853eSLai Jiangshan * irrespective of PCID. Blindly sync all roots as it would take 5991cd42853eSLai Jiangshan * roughly the same amount of work/time to determine whether any of the 5992cd42853eSLai Jiangshan * previous roots have a global mapping. 5993cd42853eSLai Jiangshan * 5994cd42853eSLai Jiangshan * Mappings not reachable via the current or previous cached roots will 5995cd42853eSLai Jiangshan * be synced when switching to that new cr3, so nothing needs to be 5996cd42853eSLai Jiangshan * done here for them. 5997cd42853eSLai Jiangshan */ 5998cd42853eSLai Jiangshan kvm_mmu_invalidate_addr(vcpu, vcpu->arch.walk_mmu, gva, KVM_MMU_ROOTS_ALL); 5999c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 6000c50d8ae3SPaolo Bonzini } 6001c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 6002c50d8ae3SPaolo Bonzini 60035efac074SPaolo Bonzini 6004c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 6005c50d8ae3SPaolo Bonzini { 6006c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 60079ebc3f51SLai Jiangshan unsigned long roots = 0; 6008c50d8ae3SPaolo Bonzini uint i; 6009c50d8ae3SPaolo Bonzini 60109ebc3f51SLai Jiangshan if (pcid == kvm_get_active_pcid(vcpu)) 60119ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_CURRENT; 6012c50d8ae3SPaolo Bonzini 6013c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 6014c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 60159ebc3f51SLai Jiangshan pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) 60169ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_PREVIOUS(i); 6017c50d8ae3SPaolo Bonzini } 6018c50d8ae3SPaolo Bonzini 60199ebc3f51SLai Jiangshan if (roots) 60209ebc3f51SLai Jiangshan kvm_mmu_invalidate_addr(vcpu, mmu, gva, roots); 6021c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 6022c50d8ae3SPaolo Bonzini 6023c50d8ae3SPaolo Bonzini /* 6024c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 6025c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 6026c50d8ae3SPaolo Bonzini * for them. 6027c50d8ae3SPaolo Bonzini */ 6028c50d8ae3SPaolo Bonzini } 6029c50d8ae3SPaolo Bonzini 6030746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 6031746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 6032c50d8ae3SPaolo Bonzini { 6033bde77235SSean Christopherson tdp_enabled = enable_tdp; 6034746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 603583013059SSean Christopherson max_tdp_level = tdp_max_root_level; 6036703c335dSSean Christopherson 60371f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 60381f98f2bdSDavid Matlack tdp_mmu_enabled = tdp_mmu_allowed && tdp_enabled; 60391f98f2bdSDavid Matlack #endif 6040703c335dSSean Christopherson /* 60411d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 6042703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 6043703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 6044703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 6045703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 6046703c335dSSean Christopherson */ 6047703c335dSSean Christopherson if (tdp_enabled) 60481d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 6049703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 60501d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 6051703c335dSSean Christopherson else 60521d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 6053c50d8ae3SPaolo Bonzini } 6054bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 6055c50d8ae3SPaolo Bonzini 6056c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 6057727ae377SSean Christopherson typedef bool (*slot_rmaps_handler) (struct kvm *kvm, 6058269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 6059269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 6060c50d8ae3SPaolo Bonzini 6061727ae377SSean Christopherson static __always_inline bool __walk_slot_rmaps(struct kvm *kvm, 6062727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6063727ae377SSean Christopherson slot_rmaps_handler fn, 6064727ae377SSean Christopherson int start_level, int end_level, 6065727ae377SSean Christopherson gfn_t start_gfn, gfn_t end_gfn, 6066727ae377SSean Christopherson bool flush_on_yield, bool flush) 6067c50d8ae3SPaolo Bonzini { 6068c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 6069c50d8ae3SPaolo Bonzini 6070eddd9e83SSean Christopherson lockdep_assert_held_write(&kvm->mmu_lock); 6071eddd9e83SSean Christopherson 6072727ae377SSean Christopherson for_each_slot_rmap_range(slot, start_level, end_level, start_gfn, 6073c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 6074c50d8ae3SPaolo Bonzini if (iterator.rmap) 6075727ae377SSean Christopherson flush |= fn(kvm, iterator.rmap, slot); 6076c50d8ae3SPaolo Bonzini 6077531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6078302695a5SSean Christopherson if (flush && flush_on_yield) { 60798c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, start_gfn, 6080c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 6081c50d8ae3SPaolo Bonzini flush = false; 6082c50d8ae3SPaolo Bonzini } 6083531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6084c50d8ae3SPaolo Bonzini } 6085c50d8ae3SPaolo Bonzini } 6086c50d8ae3SPaolo Bonzini 6087c50d8ae3SPaolo Bonzini return flush; 6088c50d8ae3SPaolo Bonzini } 6089c50d8ae3SPaolo Bonzini 6090727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps(struct kvm *kvm, 6091727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6092727ae377SSean Christopherson slot_rmaps_handler fn, 6093727ae377SSean Christopherson int start_level, int end_level, 6094302695a5SSean Christopherson bool flush_on_yield) 6095c50d8ae3SPaolo Bonzini { 6096727ae377SSean Christopherson return __walk_slot_rmaps(kvm, slot, fn, start_level, end_level, 6097727ae377SSean Christopherson slot->base_gfn, slot->base_gfn + slot->npages - 1, 60981a61b7dbSSean Christopherson flush_on_yield, false); 6099c50d8ae3SPaolo Bonzini } 6100c50d8ae3SPaolo Bonzini 6101727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps_4k(struct kvm *kvm, 6102727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6103727ae377SSean Christopherson slot_rmaps_handler fn, 6104727ae377SSean Christopherson bool flush_on_yield) 6105c50d8ae3SPaolo Bonzini { 6106727ae377SSean Christopherson return walk_slot_rmaps(kvm, slot, fn, PG_LEVEL_4K, PG_LEVEL_4K, flush_on_yield); 6107c50d8ae3SPaolo Bonzini } 6108c50d8ae3SPaolo Bonzini 6109c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 6110c50d8ae3SPaolo Bonzini { 61114a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 61124a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 6113c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 611403ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 6115cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 6116c50d8ae3SPaolo Bonzini } 6117c50d8ae3SPaolo Bonzini 611804d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 6119c50d8ae3SPaolo Bonzini { 6120c50d8ae3SPaolo Bonzini struct page *page; 6121c50d8ae3SPaolo Bonzini int i; 6122c50d8ae3SPaolo Bonzini 6123b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 6124b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 612504d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 612604d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 612704d28e37SSean Christopherson 612827f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 612927f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 613027f4fca2SLai Jiangshan return 0; 613127f4fca2SLai Jiangshan 6132c50d8ae3SPaolo Bonzini /* 6133c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 6134c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 6135c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 6136c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 613704d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 613804d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 613904d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 614004d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 614184432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 6142c50d8ae3SPaolo Bonzini */ 6143d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 6144c50d8ae3SPaolo Bonzini return 0; 6145c50d8ae3SPaolo Bonzini 6146c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 6147c50d8ae3SPaolo Bonzini if (!page) 6148c50d8ae3SPaolo Bonzini return -ENOMEM; 6149c50d8ae3SPaolo Bonzini 6150c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 61514a98623dSSean Christopherson 61524a98623dSSean Christopherson /* 61534a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 61544a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 61554a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 61564a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 61574a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 61584a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 61594a98623dSSean Christopherson */ 61604a98623dSSean Christopherson if (!tdp_enabled) 61614a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 61624a98623dSSean Christopherson else 6163e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 61644a98623dSSean Christopherson 6165c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 6166c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 6167c50d8ae3SPaolo Bonzini 6168c50d8ae3SPaolo Bonzini return 0; 6169c50d8ae3SPaolo Bonzini } 6170c50d8ae3SPaolo Bonzini 6171c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 6172c50d8ae3SPaolo Bonzini { 6173c50d8ae3SPaolo Bonzini int ret; 6174c50d8ae3SPaolo Bonzini 61755962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 61765f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 61775f6078f9SSean Christopherson 61785962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 61795f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 61805962bfb7SSean Christopherson 618196880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 618296880883SSean Christopherson 6183c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 6184c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 6185c50d8ae3SPaolo Bonzini 618604d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 6187c50d8ae3SPaolo Bonzini if (ret) 6188c50d8ae3SPaolo Bonzini return ret; 6189c50d8ae3SPaolo Bonzini 619004d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 6191c50d8ae3SPaolo Bonzini if (ret) 6192c50d8ae3SPaolo Bonzini goto fail_allocate_root; 6193c50d8ae3SPaolo Bonzini 6194c50d8ae3SPaolo Bonzini return ret; 6195c50d8ae3SPaolo Bonzini fail_allocate_root: 6196c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6197c50d8ae3SPaolo Bonzini return ret; 6198c50d8ae3SPaolo Bonzini } 6199c50d8ae3SPaolo Bonzini 6200c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 6201c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 6202c50d8ae3SPaolo Bonzini { 6203c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6204c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 6205b28cb0cdSSean Christopherson bool unstable; 6206c50d8ae3SPaolo Bonzini 6207c50d8ae3SPaolo Bonzini restart: 6208c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 6209c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 6210c50d8ae3SPaolo Bonzini /* 6211c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 6212c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 6213c50d8ae3SPaolo Bonzini */ 6214c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 6215c50d8ae3SPaolo Bonzini break; 6216c50d8ae3SPaolo Bonzini 6217c50d8ae3SPaolo Bonzini /* 6218f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 6219f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 6220f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 6221c50d8ae3SPaolo Bonzini */ 622220ba462dSSean Christopherson if (WARN_ON_ONCE(sp->role.invalid)) 6223c50d8ae3SPaolo Bonzini continue; 6224c50d8ae3SPaolo Bonzini 6225c50d8ae3SPaolo Bonzini /* 6226c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 6227c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 6228c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 6229c50d8ae3SPaolo Bonzini * be in active use by the guest. 6230c50d8ae3SPaolo Bonzini */ 6231c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 6232531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 6233c50d8ae3SPaolo Bonzini batch = 0; 6234c50d8ae3SPaolo Bonzini goto restart; 6235c50d8ae3SPaolo Bonzini } 6236c50d8ae3SPaolo Bonzini 6237b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 6238b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 6239c50d8ae3SPaolo Bonzini batch += nr_zapped; 6240b28cb0cdSSean Christopherson 6241b28cb0cdSSean Christopherson if (unstable) 6242c50d8ae3SPaolo Bonzini goto restart; 6243c50d8ae3SPaolo Bonzini } 6244c50d8ae3SPaolo Bonzini 6245c50d8ae3SPaolo Bonzini /* 62467ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 62477ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 62487ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 62497ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 62507ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 62517ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 62527ae5840eSSean Christopherson * running with an obsolete MMU. 6253c50d8ae3SPaolo Bonzini */ 6254c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 6255c50d8ae3SPaolo Bonzini } 6256c50d8ae3SPaolo Bonzini 6257c50d8ae3SPaolo Bonzini /* 6258c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 6259c50d8ae3SPaolo Bonzini * to zap obsolete pages. 6260c50d8ae3SPaolo Bonzini * 6261c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 6262c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 6263c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 6264c50d8ae3SPaolo Bonzini * after calling the function. 6265c50d8ae3SPaolo Bonzini */ 6266c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 6267c50d8ae3SPaolo Bonzini { 6268c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 6269c50d8ae3SPaolo Bonzini 6270531810caSBen Gardon write_lock(&kvm->mmu_lock); 6271c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 6272c50d8ae3SPaolo Bonzini 6273c50d8ae3SPaolo Bonzini /* 6274c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 6275c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 6276c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 6277c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 6278c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 6279c50d8ae3SPaolo Bonzini */ 6280c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 6281c50d8ae3SPaolo Bonzini 62822f6f66ccSSean Christopherson /* 62832f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 62842f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 62852f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 62862f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 6287b7cccd39SBen Gardon */ 62881f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6289b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 6290b7cccd39SBen Gardon 6291c50d8ae3SPaolo Bonzini /* 6292c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 6293c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 6294c50d8ae3SPaolo Bonzini * mmu_valid_gen. 6295c50d8ae3SPaolo Bonzini * 6296c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 6297c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 6298c50d8ae3SPaolo Bonzini */ 6299527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 6300c50d8ae3SPaolo Bonzini 6301c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 6302faaf05b0SBen Gardon 6303531810caSBen Gardon write_unlock(&kvm->mmu_lock); 63044c6654bdSBen Gardon 6305f28e9c7fSSean Christopherson /* 6306f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 6307f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 6308f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 6309f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 6310f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 6311f28e9c7fSSean Christopherson * lead to use-after-free. 6312f28e9c7fSSean Christopherson */ 63131f98f2bdSDavid Matlack if (tdp_mmu_enabled) 63144c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 6315c50d8ae3SPaolo Bonzini } 6316c50d8ae3SPaolo Bonzini 6317c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 6318c50d8ae3SPaolo Bonzini { 6319c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 6320c50d8ae3SPaolo Bonzini } 6321c50d8ae3SPaolo Bonzini 63220df9dab8SSean Christopherson void kvm_mmu_init_vm(struct kvm *kvm) 6323c50d8ae3SPaolo Bonzini { 6324a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 6325a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 632655c510e2SSean Christopherson INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages); 6327ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 6328ce25681dSSean Christopherson 63290df9dab8SSean Christopherson if (tdp_mmu_enabled) 63300df9dab8SSean Christopherson kvm_mmu_init_tdp_mmu(kvm); 6331fe5db27dSBen Gardon 6332ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 6333ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 6334ada51a9dSDavid Matlack 6335ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 6336ada51a9dSDavid Matlack 6337ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 6338ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 6339c50d8ae3SPaolo Bonzini } 6340c50d8ae3SPaolo Bonzini 6341ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 6342ada51a9dSDavid Matlack { 6343ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 6344ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6345ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6346ada51a9dSDavid Matlack } 6347ada51a9dSDavid Matlack 6348c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6349c50d8ae3SPaolo Bonzini { 635009732d2bSDavid Matlack if (tdp_mmu_enabled) 6351fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6352ada51a9dSDavid Matlack 6353ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6354c50d8ae3SPaolo Bonzini } 6355c50d8ae3SPaolo Bonzini 63562833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 635721fa3246SSean Christopherson { 635821fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 635921fa3246SSean Christopherson struct kvm_memslots *slots; 6360f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 636121fa3246SSean Christopherson bool flush = false; 636221fa3246SSean Christopherson gfn_t start, end; 6363f4209439SMaciej S. Szmigiero int i; 636421fa3246SSean Christopherson 636521fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 636621fa3246SSean Christopherson return flush; 636721fa3246SSean Christopherson 6368eed52e43SSean Christopherson for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { 636921fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6370f4209439SMaciej S. Szmigiero 6371f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6372f4209439SMaciej S. Szmigiero memslot = iter.slot; 637321fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 637421fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6375f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 637621fa3246SSean Christopherson continue; 637721fa3246SSean Christopherson 6378727ae377SSean Christopherson flush = __walk_slot_rmaps(kvm, memslot, __kvm_zap_rmap, 637921fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 638021fa3246SSean Christopherson start, end - 1, true, flush); 638121fa3246SSean Christopherson } 638221fa3246SSean Christopherson } 638321fa3246SSean Christopherson 638421fa3246SSean Christopherson return flush; 638521fa3246SSean Christopherson } 638621fa3246SSean Christopherson 638788f58535SMaxim Levitsky /* 638888f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 638988f58535SMaxim Levitsky * (not including it) 639088f58535SMaxim Levitsky */ 6391c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6392c50d8ae3SPaolo Bonzini { 639321fa3246SSean Christopherson bool flush; 6394c50d8ae3SPaolo Bonzini 6395f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6396f4209439SMaciej S. Szmigiero return; 6397f4209439SMaciej S. Szmigiero 6398531810caSBen Gardon write_lock(&kvm->mmu_lock); 63995a324c24SSean Christopherson 64008569992dSChao Peng kvm_mmu_invalidate_begin(kvm); 64018569992dSChao Peng 64028569992dSChao Peng kvm_mmu_invalidate_range_add(kvm, gfn_start, gfn_end); 6403edb298c6SMaxim Levitsky 64042833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 64056103bc07SBen Gardon 6406441a5dfcSPaolo Bonzini if (tdp_mmu_enabled) 6407441a5dfcSPaolo Bonzini flush = kvm_tdp_mmu_zap_leafs(kvm, gfn_start, gfn_end, flush); 64085a324c24SSean Christopherson 64095a324c24SSean Christopherson if (flush) 64108c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, gfn_start, gfn_end - gfn_start); 64115a324c24SSean Christopherson 64128569992dSChao Peng kvm_mmu_invalidate_end(kvm); 6413edb298c6SMaxim Levitsky 64145a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6415c50d8ae3SPaolo Bonzini } 6416c50d8ae3SPaolo Bonzini 6417c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 64180a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6419269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6420c50d8ae3SPaolo Bonzini { 64211346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6422c50d8ae3SPaolo Bonzini } 6423c50d8ae3SPaolo Bonzini 6424c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6425269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 64263c9bd400SJay Zhou int start_level) 6427c50d8ae3SPaolo Bonzini { 6428e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6429531810caSBen Gardon write_lock(&kvm->mmu_lock); 6430727ae377SSean Christopherson walk_slot_rmaps(kvm, memslot, slot_rmap_write_protect, 6431b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6432531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6433e2209710SBen Gardon } 6434c50d8ae3SPaolo Bonzini 64351f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 643624ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6437b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 643824ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 643924ae4cfaSBen Gardon } 6440c50d8ae3SPaolo Bonzini } 6441c50d8ae3SPaolo Bonzini 6442ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6443ada51a9dSDavid Matlack { 6444ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6445ada51a9dSDavid Matlack } 6446ada51a9dSDavid Matlack 6447ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6448ada51a9dSDavid Matlack { 6449ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6450ada51a9dSDavid Matlack return true; 6451ada51a9dSDavid Matlack 6452ada51a9dSDavid Matlack /* 6453ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6454ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6455ada51a9dSDavid Matlack * is possible but not worth the complexity. 6456ada51a9dSDavid Matlack */ 6457ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6458ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6459ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6460ada51a9dSDavid Matlack } 6461ada51a9dSDavid Matlack 6462ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6463ada51a9dSDavid Matlack { 6464b9b71f43SSean Christopherson /* 6465b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6466dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6467b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6468dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6469dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6470dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6471dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6472dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6473dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6474dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6475b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6476b9b71f43SSean Christopherson */ 6477b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6478b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6479ada51a9dSDavid Matlack int r; 6480ada51a9dSDavid Matlack 6481ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6482ada51a9dSDavid Matlack 6483b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6484ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6485ada51a9dSDavid Matlack if (r) 6486ada51a9dSDavid Matlack return r; 6487ada51a9dSDavid Matlack 6488ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6489ada51a9dSDavid Matlack if (r) 6490ada51a9dSDavid Matlack return r; 6491ada51a9dSDavid Matlack 6492ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6493ada51a9dSDavid Matlack } 6494ada51a9dSDavid Matlack 6495ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6496ada51a9dSDavid Matlack { 6497ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6498ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6499ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6500ada51a9dSDavid Matlack unsigned int access; 6501ada51a9dSDavid Matlack gfn_t gfn; 6502ada51a9dSDavid Matlack 650379e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 650479e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6505ada51a9dSDavid Matlack 6506ada51a9dSDavid Matlack /* 6507ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6508ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6509ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6510ada51a9dSDavid Matlack * mapped with smaller pages. 6511ada51a9dSDavid Matlack */ 6512ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6513ada51a9dSDavid Matlack 6514ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6515ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6516ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6517ada51a9dSDavid Matlack 6518ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6519ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6520ada51a9dSDavid Matlack } 6521ada51a9dSDavid Matlack 6522ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6523ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6524ada51a9dSDavid Matlack u64 *huge_sptep) 6525ada51a9dSDavid Matlack 6526ada51a9dSDavid Matlack { 6527ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6528ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6529ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 653003787394SPaolo Bonzini bool flush = false; 6531ada51a9dSDavid Matlack u64 *sptep, spte; 6532ada51a9dSDavid Matlack gfn_t gfn; 6533ada51a9dSDavid Matlack int index; 6534ada51a9dSDavid Matlack 6535ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6536ada51a9dSDavid Matlack 6537ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6538ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6539ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6540ada51a9dSDavid Matlack 6541ada51a9dSDavid Matlack /* 6542ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6543ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6544ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6545ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6546ada51a9dSDavid Matlack * modify them. 6547ada51a9dSDavid Matlack * 654803787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 654903787394SPaolo Bonzini * that lower level page table may only be partially populated. 655003787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 655103787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 655203787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 655303787394SPaolo Bonzini * fail to detect the need to flush. 6554ada51a9dSDavid Matlack */ 655503787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 655603787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6557ada51a9dSDavid Matlack continue; 655803787394SPaolo Bonzini } 6559ada51a9dSDavid Matlack 6560ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6561ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6562ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6563ada51a9dSDavid Matlack } 6564ada51a9dSDavid Matlack 656503787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6566ada51a9dSDavid Matlack } 6567ada51a9dSDavid Matlack 6568ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6569ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6570ada51a9dSDavid Matlack u64 *huge_sptep) 6571ada51a9dSDavid Matlack { 6572ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6573ada51a9dSDavid Matlack int level, r = 0; 6574ada51a9dSDavid Matlack gfn_t gfn; 6575ada51a9dSDavid Matlack u64 spte; 6576ada51a9dSDavid Matlack 6577ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 657879e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6579ada51a9dSDavid Matlack level = huge_sp->role.level; 6580ada51a9dSDavid Matlack spte = *huge_sptep; 6581ada51a9dSDavid Matlack 6582ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6583ada51a9dSDavid Matlack r = -ENOSPC; 6584ada51a9dSDavid Matlack goto out; 6585ada51a9dSDavid Matlack } 6586ada51a9dSDavid Matlack 6587ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6588ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6589ada51a9dSDavid Matlack cond_resched(); 6590ada51a9dSDavid Matlack /* 6591ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6592ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6593ada51a9dSDavid Matlack * dropped. 6594ada51a9dSDavid Matlack */ 6595ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6596ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6597ada51a9dSDavid Matlack goto out; 6598ada51a9dSDavid Matlack } 6599ada51a9dSDavid Matlack 6600ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6601ada51a9dSDavid Matlack 6602ada51a9dSDavid Matlack out: 6603ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6604ada51a9dSDavid Matlack return r; 6605ada51a9dSDavid Matlack } 6606ada51a9dSDavid Matlack 6607ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6608ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6609ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6610ada51a9dSDavid Matlack { 6611ada51a9dSDavid Matlack struct rmap_iterator iter; 6612ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6613ada51a9dSDavid Matlack u64 *huge_sptep; 6614ada51a9dSDavid Matlack int r; 6615ada51a9dSDavid Matlack 6616ada51a9dSDavid Matlack restart: 6617ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6618ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6619ada51a9dSDavid Matlack 6620ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6621ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6622ada51a9dSDavid Matlack continue; 6623ada51a9dSDavid Matlack 6624ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6625ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6626ada51a9dSDavid Matlack continue; 6627ada51a9dSDavid Matlack 6628ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6629ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6630ada51a9dSDavid Matlack continue; 6631ada51a9dSDavid Matlack 6632ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6633ada51a9dSDavid Matlack if (sp->role.invalid) 6634ada51a9dSDavid Matlack continue; 6635ada51a9dSDavid Matlack 6636ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6637ada51a9dSDavid Matlack 6638ada51a9dSDavid Matlack /* 6639ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6640ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6641ada51a9dSDavid Matlack * back into a consistent state. 6642ada51a9dSDavid Matlack */ 6643ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6644ada51a9dSDavid Matlack goto restart; 6645ada51a9dSDavid Matlack 6646ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6647ada51a9dSDavid Matlack break; 6648ada51a9dSDavid Matlack } 6649ada51a9dSDavid Matlack 6650ada51a9dSDavid Matlack return false; 6651ada51a9dSDavid Matlack } 6652ada51a9dSDavid Matlack 6653ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6654ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6655ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6656ada51a9dSDavid Matlack int target_level) 6657ada51a9dSDavid Matlack { 6658ada51a9dSDavid Matlack int level; 6659ada51a9dSDavid Matlack 6660ada51a9dSDavid Matlack /* 6661ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6662ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6663ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6664ada51a9dSDavid Matlack * already at the target level. 6665ada51a9dSDavid Matlack */ 6666727ae377SSean Christopherson for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) 6667727ae377SSean Christopherson __walk_slot_rmaps(kvm, slot, shadow_mmu_try_split_huge_pages, 6668ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6669ada51a9dSDavid Matlack } 6670ada51a9dSDavid Matlack 6671cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6672cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6673cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6674cb00a70bSDavid Matlack u64 start, u64 end, 6675cb00a70bSDavid Matlack int target_level) 6676cb00a70bSDavid Matlack { 66771f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6678ada51a9dSDavid Matlack return; 6679ada51a9dSDavid Matlack 6680ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6681ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6682ada51a9dSDavid Matlack 6683ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6684cb00a70bSDavid Matlack 6685cb00a70bSDavid Matlack /* 668654aa699eSBjorn Helgaas * A TLB flush is unnecessary at this point for the same reasons as in 6687cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6688cb00a70bSDavid Matlack */ 6689cb00a70bSDavid Matlack } 6690cb00a70bSDavid Matlack 6691a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6692a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6693a3fe5dbdSDavid Matlack int target_level) 6694a3fe5dbdSDavid Matlack { 6695a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6696a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6697a3fe5dbdSDavid Matlack 66981f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6699ada51a9dSDavid Matlack return; 6700ada51a9dSDavid Matlack 6701ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6702ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6703ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6704ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6705ada51a9dSDavid Matlack } 6706ada51a9dSDavid Matlack 6707a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6708cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6709a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6710a3fe5dbdSDavid Matlack 6711a3fe5dbdSDavid Matlack /* 6712a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6713a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6714a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6715a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6716a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6717a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6718a3fe5dbdSDavid Matlack * SPTEs. 6719a3fe5dbdSDavid Matlack */ 6720a3fe5dbdSDavid Matlack } 6721a3fe5dbdSDavid Matlack 6722c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 67230a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6724269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6725c50d8ae3SPaolo Bonzini { 6726c50d8ae3SPaolo Bonzini u64 *sptep; 6727c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6728c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6729c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6730c50d8ae3SPaolo Bonzini 6731c50d8ae3SPaolo Bonzini restart: 6732c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 673357354682SSean Christopherson sp = sptep_to_sp(sptep); 6734c50d8ae3SPaolo Bonzini 6735c50d8ae3SPaolo Bonzini /* 6736c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6737c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6738c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6739c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6740c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6741c50d8ae3SPaolo Bonzini */ 67425d49f08cSSean Christopherson if (sp->role.direct && 67439eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6744a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 67459202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6746c50d8ae3SPaolo Bonzini 67478a1300ffSSean Christopherson if (kvm_available_flush_remote_tlbs_range()) 67481b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 6749c50d8ae3SPaolo Bonzini else 6750c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6751c50d8ae3SPaolo Bonzini 6752c50d8ae3SPaolo Bonzini goto restart; 6753c50d8ae3SPaolo Bonzini } 6754c50d8ae3SPaolo Bonzini } 6755c50d8ae3SPaolo Bonzini 6756c50d8ae3SPaolo Bonzini return need_tlb_flush; 6757c50d8ae3SPaolo Bonzini } 6758c50d8ae3SPaolo Bonzini 675920d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 676020d49186SDavid Matlack const struct kvm_memory_slot *slot) 676120d49186SDavid Matlack { 676220d49186SDavid Matlack /* 676320d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 676420d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 676520d49186SDavid Matlack */ 6766727ae377SSean Christopherson if (walk_slot_rmaps(kvm, slot, kvm_mmu_zap_collapsible_spte, 676720d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 6768619b5072SDavid Matlack kvm_flush_remote_tlbs_memslot(kvm, slot); 676920d49186SDavid Matlack } 677020d49186SDavid Matlack 6771c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6772269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6773c50d8ae3SPaolo Bonzini { 6774e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6775531810caSBen Gardon write_lock(&kvm->mmu_lock); 677620d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6777531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6778e2209710SBen Gardon } 67792db6f772SBen Gardon 67801f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 67812db6f772SBen Gardon read_lock(&kvm->mmu_lock); 67824b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 67832db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 67842db6f772SBen Gardon } 6785c50d8ae3SPaolo Bonzini } 6786c50d8ae3SPaolo Bonzini 6787c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6788269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6789c50d8ae3SPaolo Bonzini { 6790e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6791531810caSBen Gardon write_lock(&kvm->mmu_lock); 6792610265eaSDavid Matlack /* 6793610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6794610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6795610265eaSDavid Matlack */ 6796727ae377SSean Christopherson walk_slot_rmaps_4k(kvm, memslot, __rmap_clear_dirty, false); 6797531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6798e2209710SBen Gardon } 6799c50d8ae3SPaolo Bonzini 68001f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 680124ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6802b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 680324ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 680424ae4cfaSBen Gardon } 680524ae4cfaSBen Gardon 6806c50d8ae3SPaolo Bonzini /* 6807b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6808b64d740eSJunaid Shahid * 6809c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6810c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6811c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6812c50d8ae3SPaolo Bonzini * dirty_bitmap. 6813c50d8ae3SPaolo Bonzini */ 6814c50d8ae3SPaolo Bonzini } 6815c50d8ae3SPaolo Bonzini 6816db0d70e6SSean Christopherson static void kvm_mmu_zap_all(struct kvm *kvm) 6817c50d8ae3SPaolo Bonzini { 6818c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6819c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6820c50d8ae3SPaolo Bonzini int ign; 6821c50d8ae3SPaolo Bonzini 6822531810caSBen Gardon write_lock(&kvm->mmu_lock); 6823c50d8ae3SPaolo Bonzini restart: 6824c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 682520ba462dSSean Christopherson if (WARN_ON_ONCE(sp->role.invalid)) 6826c50d8ae3SPaolo Bonzini continue; 6827c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6828c50d8ae3SPaolo Bonzini goto restart; 6829531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6830c50d8ae3SPaolo Bonzini goto restart; 6831c50d8ae3SPaolo Bonzini } 6832c50d8ae3SPaolo Bonzini 6833c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6834faaf05b0SBen Gardon 68351f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6836faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6837faaf05b0SBen Gardon 6838531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6839c50d8ae3SPaolo Bonzini } 6840c50d8ae3SPaolo Bonzini 6841db0d70e6SSean Christopherson void kvm_arch_flush_shadow_all(struct kvm *kvm) 6842db0d70e6SSean Christopherson { 6843db0d70e6SSean Christopherson kvm_mmu_zap_all(kvm); 6844db0d70e6SSean Christopherson } 6845db0d70e6SSean Christopherson 6846db0d70e6SSean Christopherson void kvm_arch_flush_shadow_memslot(struct kvm *kvm, 6847db0d70e6SSean Christopherson struct kvm_memory_slot *slot) 6848db0d70e6SSean Christopherson { 6849eeb87272SSean Christopherson kvm_mmu_zap_all_fast(kvm); 6850db0d70e6SSean Christopherson } 6851db0d70e6SSean Christopherson 6852c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6853c50d8ae3SPaolo Bonzini { 685420ba462dSSean Christopherson WARN_ON_ONCE(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6855c50d8ae3SPaolo Bonzini 6856c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6857c50d8ae3SPaolo Bonzini 6858c50d8ae3SPaolo Bonzini /* 6859c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6860c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6861c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6862c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6863c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6864c50d8ae3SPaolo Bonzini */ 6865eed52e43SSean Christopherson gen &= ~((u64)kvm_arch_nr_memslot_as_ids(kvm) - 1); 6866c50d8ae3SPaolo Bonzini 6867c50d8ae3SPaolo Bonzini /* 6868c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6869c50d8ae3SPaolo Bonzini * zap all shadow pages. 6870c50d8ae3SPaolo Bonzini */ 6871c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 68728d20bd63SSean Christopherson kvm_debug_ratelimited("zapping shadow pages for mmio generation wraparound\n"); 6873c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6874c50d8ae3SPaolo Bonzini } 6875c50d8ae3SPaolo Bonzini } 6876c50d8ae3SPaolo Bonzini 6877f3d90f90SSean Christopherson static unsigned long mmu_shrink_scan(struct shrinker *shrink, 6878f3d90f90SSean Christopherson struct shrink_control *sc) 6879c50d8ae3SPaolo Bonzini { 6880c50d8ae3SPaolo Bonzini struct kvm *kvm; 6881c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6882c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6883c50d8ae3SPaolo Bonzini 6884c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6885c50d8ae3SPaolo Bonzini 6886c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6887c50d8ae3SPaolo Bonzini int idx; 6888c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6889c50d8ae3SPaolo Bonzini 6890c50d8ae3SPaolo Bonzini /* 6891c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6892c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6893c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6894c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6895c50d8ae3SPaolo Bonzini */ 6896c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6897c50d8ae3SPaolo Bonzini break; 6898c50d8ae3SPaolo Bonzini /* 6899c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6900c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6901c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6902c50d8ae3SPaolo Bonzini * anyway. 6903c50d8ae3SPaolo Bonzini */ 6904c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6905c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6906c50d8ae3SPaolo Bonzini continue; 6907c50d8ae3SPaolo Bonzini 6908c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6909531810caSBen Gardon write_lock(&kvm->mmu_lock); 6910c50d8ae3SPaolo Bonzini 6911c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6912c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6913c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6914c50d8ae3SPaolo Bonzini goto unlock; 6915c50d8ae3SPaolo Bonzini } 6916c50d8ae3SPaolo Bonzini 6917ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6918c50d8ae3SPaolo Bonzini 6919c50d8ae3SPaolo Bonzini unlock: 6920531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6921c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6922c50d8ae3SPaolo Bonzini 6923c50d8ae3SPaolo Bonzini /* 6924c50d8ae3SPaolo Bonzini * unfair on small ones 6925c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6926c50d8ae3SPaolo Bonzini * sadness comes quickly 6927c50d8ae3SPaolo Bonzini */ 6928c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6929c50d8ae3SPaolo Bonzini break; 6930c50d8ae3SPaolo Bonzini } 6931c50d8ae3SPaolo Bonzini 6932c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6933c50d8ae3SPaolo Bonzini return freed; 6934c50d8ae3SPaolo Bonzini } 6935c50d8ae3SPaolo Bonzini 6936f3d90f90SSean Christopherson static unsigned long mmu_shrink_count(struct shrinker *shrink, 6937f3d90f90SSean Christopherson struct shrink_control *sc) 6938c50d8ae3SPaolo Bonzini { 6939c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6940c50d8ae3SPaolo Bonzini } 6941c50d8ae3SPaolo Bonzini 6942e5985c40SQi Zheng static struct shrinker *mmu_shrinker; 6943c50d8ae3SPaolo Bonzini 6944c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6945c50d8ae3SPaolo Bonzini { 6946c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6947c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6948c50d8ae3SPaolo Bonzini } 6949c50d8ae3SPaolo Bonzini 69500b210fafSSean Christopherson static int get_nx_huge_pages(char *buffer, const struct kernel_param *kp) 69510b210fafSSean Christopherson { 69520b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 69531d6664faSLike Xu return sysfs_emit(buffer, "never\n"); 69540b210fafSSean Christopherson 69550b210fafSSean Christopherson return param_get_bool(buffer, kp); 69560b210fafSSean Christopherson } 69570b210fafSSean Christopherson 6958c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6959c50d8ae3SPaolo Bonzini { 6960c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6961c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6962c50d8ae3SPaolo Bonzini } 6963c50d8ae3SPaolo Bonzini 6964c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6965c50d8ae3SPaolo Bonzini { 6966c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6967c50d8ae3SPaolo Bonzini } 6968c50d8ae3SPaolo Bonzini 6969c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6970c50d8ae3SPaolo Bonzini { 6971c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6972c50d8ae3SPaolo Bonzini bool new_val; 6973c50d8ae3SPaolo Bonzini 69740b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 69750b210fafSSean Christopherson return -EPERM; 69760b210fafSSean Christopherson 6977c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 69780b210fafSSean Christopherson if (sysfs_streq(val, "off")) { 6979c50d8ae3SPaolo Bonzini new_val = 0; 69800b210fafSSean Christopherson } else if (sysfs_streq(val, "force")) { 6981c50d8ae3SPaolo Bonzini new_val = 1; 69820b210fafSSean Christopherson } else if (sysfs_streq(val, "auto")) { 6983c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 69840b210fafSSean Christopherson } else if (sysfs_streq(val, "never")) { 69850b210fafSSean Christopherson new_val = 0; 69860b210fafSSean Christopherson 69870b210fafSSean Christopherson mutex_lock(&kvm_lock); 69880b210fafSSean Christopherson if (!list_empty(&vm_list)) { 69890b210fafSSean Christopherson mutex_unlock(&kvm_lock); 69900b210fafSSean Christopherson return -EBUSY; 69910b210fafSSean Christopherson } 69920b210fafSSean Christopherson nx_hugepage_mitigation_hard_disabled = true; 69930b210fafSSean Christopherson mutex_unlock(&kvm_lock); 69940b210fafSSean Christopherson } else if (kstrtobool(val, &new_val) < 0) { 6995c50d8ae3SPaolo Bonzini return -EINVAL; 69960b210fafSSean Christopherson } 6997c50d8ae3SPaolo Bonzini 6998c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6999c50d8ae3SPaolo Bonzini 7000c50d8ae3SPaolo Bonzini if (new_val != old_val) { 7001c50d8ae3SPaolo Bonzini struct kvm *kvm; 7002c50d8ae3SPaolo Bonzini 7003c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 7004c50d8ae3SPaolo Bonzini 7005c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 7006c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 7007c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 7008c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 7009c50d8ae3SPaolo Bonzini 701055c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 7011c50d8ae3SPaolo Bonzini } 7012c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 7013c50d8ae3SPaolo Bonzini } 7014c50d8ae3SPaolo Bonzini 7015c50d8ae3SPaolo Bonzini return 0; 7016c50d8ae3SPaolo Bonzini } 7017c50d8ae3SPaolo Bonzini 70181d0e8480SSean Christopherson /* 70191d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 70201d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 7021c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 7022c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 70231d0e8480SSean Christopherson */ 7024982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 7025c50d8ae3SPaolo Bonzini { 7026c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 7027c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 7028c3e0c8c2SSean Christopherson 70291f98f2bdSDavid Matlack /* 70301f98f2bdSDavid Matlack * Snapshot userspace's desire to enable the TDP MMU. Whether or not the 70311f98f2bdSDavid Matlack * TDP MMU is actually enabled is determined in kvm_configure_mmu() 70321f98f2bdSDavid Matlack * when the vendor module is loaded. 70331f98f2bdSDavid Matlack */ 70341f98f2bdSDavid Matlack tdp_mmu_allowed = tdp_mmu_enabled; 70351f98f2bdSDavid Matlack 7036c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 70371d0e8480SSean Christopherson } 70381d0e8480SSean Christopherson 70391d0e8480SSean Christopherson /* 70401d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 70411d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 70421d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 70431d0e8480SSean Christopherson */ 70441d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 70451d0e8480SSean Christopherson { 70461d0e8480SSean Christopherson int ret = -ENOMEM; 7047c50d8ae3SPaolo Bonzini 7048c50d8ae3SPaolo Bonzini /* 7049c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 7050c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 7051c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 7052c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 7053c50d8ae3SPaolo Bonzini */ 7054c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 7055c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 70567a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 7057c50d8ae3SPaolo Bonzini 7058c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 7059c50d8ae3SPaolo Bonzini 70600dbd0546SKunwu Chan pte_list_desc_cache = KMEM_CACHE(pte_list_desc, SLAB_ACCOUNT); 7061c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 7062c50d8ae3SPaolo Bonzini goto out; 7063c50d8ae3SPaolo Bonzini 7064c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 7065c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 7066c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 7067c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 7068c50d8ae3SPaolo Bonzini goto out; 7069c50d8ae3SPaolo Bonzini 7070c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 7071c50d8ae3SPaolo Bonzini goto out; 7072c50d8ae3SPaolo Bonzini 7073e5985c40SQi Zheng mmu_shrinker = shrinker_alloc(0, "x86-mmu"); 7074e5985c40SQi Zheng if (!mmu_shrinker) 7075d7c9bfb9SMiaohe Lin goto out_shrinker; 7076c50d8ae3SPaolo Bonzini 7077e5985c40SQi Zheng mmu_shrinker->count_objects = mmu_shrink_count; 7078e5985c40SQi Zheng mmu_shrinker->scan_objects = mmu_shrink_scan; 7079e5985c40SQi Zheng mmu_shrinker->seeks = DEFAULT_SEEKS * 10; 7080e5985c40SQi Zheng 7081e5985c40SQi Zheng shrinker_register(mmu_shrinker); 7082e5985c40SQi Zheng 7083c50d8ae3SPaolo Bonzini return 0; 7084c50d8ae3SPaolo Bonzini 7085d7c9bfb9SMiaohe Lin out_shrinker: 7086d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 7087c50d8ae3SPaolo Bonzini out: 7088c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 7089c50d8ae3SPaolo Bonzini return ret; 7090c50d8ae3SPaolo Bonzini } 7091c50d8ae3SPaolo Bonzini 7092c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 7093c50d8ae3SPaolo Bonzini { 7094c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 7095c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 7096c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 7097c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 7098c50d8ae3SPaolo Bonzini } 7099c50d8ae3SPaolo Bonzini 71001d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 7101c50d8ae3SPaolo Bonzini { 7102c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 7103c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 7104e5985c40SQi Zheng shrinker_free(mmu_shrinker); 7105c50d8ae3SPaolo Bonzini } 7106c50d8ae3SPaolo Bonzini 7107f47491d7SSean Christopherson /* 7108f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 7109f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 7110f47491d7SSean Christopherson */ 7111f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 7112f47491d7SSean Christopherson { 7113f47491d7SSean Christopherson /* 7114f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 7115f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 7116f47491d7SSean Christopherson */ 7117f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 7118f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 7119f47491d7SSean Christopherson 7120f47491d7SSean Christopherson if (!enabled || !ratio) 7121f47491d7SSean Christopherson return false; 7122f47491d7SSean Christopherson 7123f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 7124f47491d7SSean Christopherson if (!*period) { 7125f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 7126f47491d7SSean Christopherson ratio = min(ratio, 3600u); 7127f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 7128f47491d7SSean Christopherson } 7129f47491d7SSean Christopherson return true; 7130f47491d7SSean Christopherson } 7131f47491d7SSean Christopherson 71324dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 7133c50d8ae3SPaolo Bonzini { 71344dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 71354dfe4f40SJunaid Shahid uint old_period, new_period; 7136c50d8ae3SPaolo Bonzini int err; 7137c50d8ae3SPaolo Bonzini 71380b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 71390b210fafSSean Christopherson return -EPERM; 71400b210fafSSean Christopherson 7141f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 71424dfe4f40SJunaid Shahid 7143c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 7144c50d8ae3SPaolo Bonzini if (err) 7145c50d8ae3SPaolo Bonzini return err; 7146c50d8ae3SPaolo Bonzini 7147f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 71484dfe4f40SJunaid Shahid 7149f47491d7SSean Christopherson if (is_recovery_enabled && 71504dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 7151c50d8ae3SPaolo Bonzini struct kvm *kvm; 7152c50d8ae3SPaolo Bonzini 7153c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 7154c50d8ae3SPaolo Bonzini 7155c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 715655c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 7157c50d8ae3SPaolo Bonzini 7158c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 7159c50d8ae3SPaolo Bonzini } 7160c50d8ae3SPaolo Bonzini 7161c50d8ae3SPaolo Bonzini return err; 7162c50d8ae3SPaolo Bonzini } 7163c50d8ae3SPaolo Bonzini 716455c510e2SSean Christopherson static void kvm_recover_nx_huge_pages(struct kvm *kvm) 7165c50d8ae3SPaolo Bonzini { 7166ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 7167eb298605SDavid Matlack struct kvm_memory_slot *slot; 7168c50d8ae3SPaolo Bonzini int rcu_idx; 7169c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 7170c50d8ae3SPaolo Bonzini unsigned int ratio; 7171c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 7172048f4980SSean Christopherson bool flush = false; 7173c50d8ae3SPaolo Bonzini ulong to_zap; 7174c50d8ae3SPaolo Bonzini 7175c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 7176531810caSBen Gardon write_lock(&kvm->mmu_lock); 7177c50d8ae3SPaolo Bonzini 7178bb95dfb9SSean Christopherson /* 7179bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 7180bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 7181bb95dfb9SSean Christopherson * callback. 7182bb95dfb9SSean Christopherson */ 7183bb95dfb9SSean Christopherson rcu_read_lock(); 7184bb95dfb9SSean Christopherson 7185c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 7186ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 71877d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 718855c510e2SSean Christopherson if (list_empty(&kvm->arch.possible_nx_huge_pages)) 71897d919c7aSSean Christopherson break; 71907d919c7aSSean Christopherson 7191c50d8ae3SPaolo Bonzini /* 7192c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 719355c510e2SSean Christopherson * because the number of shadow pages that be replaced with an 719455c510e2SSean Christopherson * NX huge page is expected to be relatively small compared to 719555c510e2SSean Christopherson * the total number of shadow pages. And because the TDP MMU 719655c510e2SSean Christopherson * doesn't use active_mmu_pages. 7197c50d8ae3SPaolo Bonzini */ 719855c510e2SSean Christopherson sp = list_first_entry(&kvm->arch.possible_nx_huge_pages, 7199c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 720055c510e2SSean Christopherson possible_nx_huge_page_link); 720155c510e2SSean Christopherson WARN_ON_ONCE(!sp->nx_huge_page_disallowed); 7202eb298605SDavid Matlack WARN_ON_ONCE(!sp->role.direct); 7203eb298605SDavid Matlack 7204eb298605SDavid Matlack /* 7205eb298605SDavid Matlack * Unaccount and do not attempt to recover any NX Huge Pages 7206eb298605SDavid Matlack * that are being dirty tracked, as they would just be faulted 7207eb298605SDavid Matlack * back in as 4KiB pages. The NX Huge Pages in this slot will be 7208eb298605SDavid Matlack * recovered, along with all the other huge pages in the slot, 7209eb298605SDavid Matlack * when dirty logging is disabled. 72106c7b2202SPaolo Bonzini * 72116c7b2202SPaolo Bonzini * Since gfn_to_memslot() is relatively expensive, it helps to 72126c7b2202SPaolo Bonzini * skip it if it the test cannot possibly return true. On the 72136c7b2202SPaolo Bonzini * other hand, if any memslot has logging enabled, chances are 72146c7b2202SPaolo Bonzini * good that all of them do, in which case unaccount_nx_huge_page() 72156c7b2202SPaolo Bonzini * is much cheaper than zapping the page. 72166c7b2202SPaolo Bonzini * 72176c7b2202SPaolo Bonzini * If a memslot update is in progress, reading an incorrect value 72186c7b2202SPaolo Bonzini * of kvm->nr_memslots_dirty_logging is not a problem: if it is 72196c7b2202SPaolo Bonzini * becoming zero, gfn_to_memslot() will be done unnecessarily; if 72206c7b2202SPaolo Bonzini * it is becoming nonzero, the page will be zapped unnecessarily. 72216c7b2202SPaolo Bonzini * Either way, this only affects efficiency in racy situations, 72226c7b2202SPaolo Bonzini * and not correctness. 7223eb298605SDavid Matlack */ 72246c7b2202SPaolo Bonzini slot = NULL; 72256c7b2202SPaolo Bonzini if (atomic_read(&kvm->nr_memslots_dirty_logging)) { 7226817fa998SSean Christopherson struct kvm_memslots *slots; 7227817fa998SSean Christopherson 7228817fa998SSean Christopherson slots = kvm_memslots_for_spte_role(kvm, sp->role); 7229817fa998SSean Christopherson slot = __gfn_to_memslot(slots, sp->gfn); 72306c7b2202SPaolo Bonzini WARN_ON_ONCE(!slot); 723129cf0f50SBen Gardon } 7232c50d8ae3SPaolo Bonzini 7233eb298605SDavid Matlack if (slot && kvm_slot_dirty_track_enabled(slot)) 7234eb298605SDavid Matlack unaccount_nx_huge_page(kvm, sp); 7235eb298605SDavid Matlack else if (is_tdp_mmu_page(sp)) 7236c50d8ae3SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 72373a056757SSean Christopherson else 7238c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 723955c510e2SSean Christopherson WARN_ON_ONCE(sp->nx_huge_page_disallowed); 7240c50d8ae3SPaolo Bonzini 7241531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 7242048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7243bb95dfb9SSean Christopherson rcu_read_unlock(); 7244bb95dfb9SSean Christopherson 7245531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 7246048f4980SSean Christopherson flush = false; 7247bb95dfb9SSean Christopherson 7248bb95dfb9SSean Christopherson rcu_read_lock(); 7249c50d8ae3SPaolo Bonzini } 7250c50d8ae3SPaolo Bonzini } 7251048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7252c50d8ae3SPaolo Bonzini 7253bb95dfb9SSean Christopherson rcu_read_unlock(); 7254bb95dfb9SSean Christopherson 7255531810caSBen Gardon write_unlock(&kvm->mmu_lock); 7256c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 7257c50d8ae3SPaolo Bonzini } 7258c50d8ae3SPaolo Bonzini 725955c510e2SSean Christopherson static long get_nx_huge_page_recovery_timeout(u64 start_time) 7260c50d8ae3SPaolo Bonzini { 7261f47491d7SSean Christopherson bool enabled; 7262f47491d7SSean Christopherson uint period; 72634dfe4f40SJunaid Shahid 7264f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 72654dfe4f40SJunaid Shahid 7266f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 7267c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 7268c50d8ae3SPaolo Bonzini } 7269c50d8ae3SPaolo Bonzini 727055c510e2SSean Christopherson static int kvm_nx_huge_page_recovery_worker(struct kvm *kvm, uintptr_t data) 7271c50d8ae3SPaolo Bonzini { 7272c50d8ae3SPaolo Bonzini u64 start_time; 7273c50d8ae3SPaolo Bonzini long remaining_time; 7274c50d8ae3SPaolo Bonzini 7275c50d8ae3SPaolo Bonzini while (true) { 7276c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 727755c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7278c50d8ae3SPaolo Bonzini 7279c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7280c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 7281c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 728255c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7283c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7284c50d8ae3SPaolo Bonzini } 7285c50d8ae3SPaolo Bonzini 7286c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 7287c50d8ae3SPaolo Bonzini 7288c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 7289c50d8ae3SPaolo Bonzini return 0; 7290c50d8ae3SPaolo Bonzini 729155c510e2SSean Christopherson kvm_recover_nx_huge_pages(kvm); 7292c50d8ae3SPaolo Bonzini } 7293c50d8ae3SPaolo Bonzini } 7294c50d8ae3SPaolo Bonzini 7295c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 7296c50d8ae3SPaolo Bonzini { 7297c50d8ae3SPaolo Bonzini int err; 7298c50d8ae3SPaolo Bonzini 72990b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 73000b210fafSSean Christopherson return 0; 73010b210fafSSean Christopherson 730255c510e2SSean Christopherson err = kvm_vm_create_worker_thread(kvm, kvm_nx_huge_page_recovery_worker, 0, 7303c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 730455c510e2SSean Christopherson &kvm->arch.nx_huge_page_recovery_thread); 7305c50d8ae3SPaolo Bonzini if (!err) 730655c510e2SSean Christopherson kthread_unpark(kvm->arch.nx_huge_page_recovery_thread); 7307c50d8ae3SPaolo Bonzini 7308c50d8ae3SPaolo Bonzini return err; 7309c50d8ae3SPaolo Bonzini } 7310c50d8ae3SPaolo Bonzini 7311c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 7312c50d8ae3SPaolo Bonzini { 731355c510e2SSean Christopherson if (kvm->arch.nx_huge_page_recovery_thread) 731455c510e2SSean Christopherson kthread_stop(kvm->arch.nx_huge_page_recovery_thread); 7315c50d8ae3SPaolo Bonzini } 731690b4fe17SChao Peng 731790b4fe17SChao Peng #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES 73188dd2eee9SChao Peng bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm, 73198dd2eee9SChao Peng struct kvm_gfn_range *range) 73208dd2eee9SChao Peng { 73218dd2eee9SChao Peng /* 73228dd2eee9SChao Peng * Zap SPTEs even if the slot can't be mapped PRIVATE. KVM x86 only 73238dd2eee9SChao Peng * supports KVM_MEMORY_ATTRIBUTE_PRIVATE, and so it *seems* like KVM 73248dd2eee9SChao Peng * can simply ignore such slots. But if userspace is making memory 73258dd2eee9SChao Peng * PRIVATE, then KVM must prevent the guest from accessing the memory 73268dd2eee9SChao Peng * as shared. And if userspace is making memory SHARED and this point 73278dd2eee9SChao Peng * is reached, then at least one page within the range was previously 73288dd2eee9SChao Peng * PRIVATE, i.e. the slot's possible hugepage ranges are changing. 73298dd2eee9SChao Peng * Zapping SPTEs in this case ensures KVM will reassess whether or not 73308dd2eee9SChao Peng * a hugepage can be used for affected ranges. 73318dd2eee9SChao Peng */ 73328dd2eee9SChao Peng if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm))) 73338dd2eee9SChao Peng return false; 73348dd2eee9SChao Peng 73358dd2eee9SChao Peng return kvm_unmap_gfn_range(kvm, range); 73368dd2eee9SChao Peng } 73378dd2eee9SChao Peng 733890b4fe17SChao Peng static bool hugepage_test_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 733990b4fe17SChao Peng int level) 734090b4fe17SChao Peng { 734190b4fe17SChao Peng return lpage_info_slot(gfn, slot, level)->disallow_lpage & KVM_LPAGE_MIXED_FLAG; 734290b4fe17SChao Peng } 734390b4fe17SChao Peng 734490b4fe17SChao Peng static void hugepage_clear_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 734590b4fe17SChao Peng int level) 734690b4fe17SChao Peng { 734790b4fe17SChao Peng lpage_info_slot(gfn, slot, level)->disallow_lpage &= ~KVM_LPAGE_MIXED_FLAG; 734890b4fe17SChao Peng } 734990b4fe17SChao Peng 735090b4fe17SChao Peng static void hugepage_set_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 735190b4fe17SChao Peng int level) 735290b4fe17SChao Peng { 735390b4fe17SChao Peng lpage_info_slot(gfn, slot, level)->disallow_lpage |= KVM_LPAGE_MIXED_FLAG; 735490b4fe17SChao Peng } 735590b4fe17SChao Peng 735690b4fe17SChao Peng static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot, 735790b4fe17SChao Peng gfn_t gfn, int level, unsigned long attrs) 735890b4fe17SChao Peng { 735990b4fe17SChao Peng const unsigned long start = gfn; 736090b4fe17SChao Peng const unsigned long end = start + KVM_PAGES_PER_HPAGE(level); 736190b4fe17SChao Peng 736290b4fe17SChao Peng if (level == PG_LEVEL_2M) 736390b4fe17SChao Peng return kvm_range_has_memory_attributes(kvm, start, end, attrs); 736490b4fe17SChao Peng 736590b4fe17SChao Peng for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) { 736690b4fe17SChao Peng if (hugepage_test_mixed(slot, gfn, level - 1) || 736790b4fe17SChao Peng attrs != kvm_get_memory_attributes(kvm, gfn)) 736890b4fe17SChao Peng return false; 736990b4fe17SChao Peng } 737090b4fe17SChao Peng return true; 737190b4fe17SChao Peng } 737290b4fe17SChao Peng 737390b4fe17SChao Peng bool kvm_arch_post_set_memory_attributes(struct kvm *kvm, 737490b4fe17SChao Peng struct kvm_gfn_range *range) 737590b4fe17SChao Peng { 737690b4fe17SChao Peng unsigned long attrs = range->arg.attributes; 737790b4fe17SChao Peng struct kvm_memory_slot *slot = range->slot; 737890b4fe17SChao Peng int level; 737990b4fe17SChao Peng 738090b4fe17SChao Peng lockdep_assert_held_write(&kvm->mmu_lock); 738190b4fe17SChao Peng lockdep_assert_held(&kvm->slots_lock); 738290b4fe17SChao Peng 738390b4fe17SChao Peng /* 738490b4fe17SChao Peng * Calculate which ranges can be mapped with hugepages even if the slot 738590b4fe17SChao Peng * can't map memory PRIVATE. KVM mustn't create a SHARED hugepage over 738690b4fe17SChao Peng * a range that has PRIVATE GFNs, and conversely converting a range to 738790b4fe17SChao Peng * SHARED may now allow hugepages. 738890b4fe17SChao Peng */ 738990b4fe17SChao Peng if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm))) 739090b4fe17SChao Peng return false; 739190b4fe17SChao Peng 739290b4fe17SChao Peng /* 739390b4fe17SChao Peng * The sequence matters here: upper levels consume the result of lower 739490b4fe17SChao Peng * level's scanning. 739590b4fe17SChao Peng */ 739690b4fe17SChao Peng for (level = PG_LEVEL_2M; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) { 739790b4fe17SChao Peng gfn_t nr_pages = KVM_PAGES_PER_HPAGE(level); 739890b4fe17SChao Peng gfn_t gfn = gfn_round_for_level(range->start, level); 739990b4fe17SChao Peng 740090b4fe17SChao Peng /* Process the head page if it straddles the range. */ 740190b4fe17SChao Peng if (gfn != range->start || gfn + nr_pages > range->end) { 740290b4fe17SChao Peng /* 740390b4fe17SChao Peng * Skip mixed tracking if the aligned gfn isn't covered 740490b4fe17SChao Peng * by the memslot, KVM can't use a hugepage due to the 740590b4fe17SChao Peng * misaligned address regardless of memory attributes. 740690b4fe17SChao Peng */ 740790b4fe17SChao Peng if (gfn >= slot->base_gfn) { 740890b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 740990b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 741090b4fe17SChao Peng else 741190b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 741290b4fe17SChao Peng } 741390b4fe17SChao Peng gfn += nr_pages; 741490b4fe17SChao Peng } 741590b4fe17SChao Peng 741690b4fe17SChao Peng /* 741790b4fe17SChao Peng * Pages entirely covered by the range are guaranteed to have 741890b4fe17SChao Peng * only the attributes which were just set. 741990b4fe17SChao Peng */ 742090b4fe17SChao Peng for ( ; gfn + nr_pages <= range->end; gfn += nr_pages) 742190b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 742290b4fe17SChao Peng 742390b4fe17SChao Peng /* 742490b4fe17SChao Peng * Process the last tail page if it straddles the range and is 742590b4fe17SChao Peng * contained by the memslot. Like the head page, KVM can't 742690b4fe17SChao Peng * create a hugepage if the slot size is misaligned. 742790b4fe17SChao Peng */ 742890b4fe17SChao Peng if (gfn < range->end && 742990b4fe17SChao Peng (gfn + nr_pages) <= (slot->base_gfn + slot->npages)) { 743090b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 743190b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 743290b4fe17SChao Peng else 743390b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 743490b4fe17SChao Peng } 743590b4fe17SChao Peng } 743690b4fe17SChao Peng return false; 743790b4fe17SChao Peng } 743890b4fe17SChao Peng 743990b4fe17SChao Peng void kvm_mmu_init_memslot_memory_attributes(struct kvm *kvm, 744090b4fe17SChao Peng struct kvm_memory_slot *slot) 744190b4fe17SChao Peng { 744290b4fe17SChao Peng int level; 744390b4fe17SChao Peng 744490b4fe17SChao Peng if (!kvm_arch_has_private_mem(kvm)) 744590b4fe17SChao Peng return; 744690b4fe17SChao Peng 744790b4fe17SChao Peng for (level = PG_LEVEL_2M; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) { 744890b4fe17SChao Peng /* 744990b4fe17SChao Peng * Don't bother tracking mixed attributes for pages that can't 745090b4fe17SChao Peng * be huge due to alignment, i.e. process only pages that are 745190b4fe17SChao Peng * entirely contained by the memslot. 745290b4fe17SChao Peng */ 745390b4fe17SChao Peng gfn_t end = gfn_round_for_level(slot->base_gfn + slot->npages, level); 745490b4fe17SChao Peng gfn_t start = gfn_round_for_level(slot->base_gfn, level); 745590b4fe17SChao Peng gfn_t nr_pages = KVM_PAGES_PER_HPAGE(level); 745690b4fe17SChao Peng gfn_t gfn; 745790b4fe17SChao Peng 745890b4fe17SChao Peng if (start < slot->base_gfn) 745990b4fe17SChao Peng start += nr_pages; 746090b4fe17SChao Peng 746190b4fe17SChao Peng /* 746290b4fe17SChao Peng * Unlike setting attributes, every potential hugepage needs to 746390b4fe17SChao Peng * be manually checked as the attributes may already be mixed. 746490b4fe17SChao Peng */ 746590b4fe17SChao Peng for (gfn = start; gfn < end; gfn += nr_pages) { 746690b4fe17SChao Peng unsigned long attrs = kvm_get_memory_attributes(kvm, gfn); 746790b4fe17SChao Peng 746890b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 746990b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 747090b4fe17SChao Peng else 747190b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 747290b4fe17SChao Peng } 747390b4fe17SChao Peng } 747490b4fe17SChao Peng } 747590b4fe17SChao Peng #endif 7476