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> 50c50d8ae3SPaolo Bonzini 51c50d8ae3SPaolo Bonzini #include <asm/page.h> 52eb243d1dSIngo Molnar #include <asm/memtype.h> 53c50d8ae3SPaolo Bonzini #include <asm/cmpxchg.h> 54c50d8ae3SPaolo Bonzini #include <asm/io.h> 554a98623dSSean Christopherson #include <asm/set_memory.h> 56*65efc4dcSThomas Gleixner #include <asm/spec-ctrl.h> 57c50d8ae3SPaolo Bonzini #include <asm/vmx.h> 5858ea7cf7SSean Christopherson 59c50d8ae3SPaolo Bonzini #include "trace.h" 60c50d8ae3SPaolo Bonzini 610b210fafSSean Christopherson static bool nx_hugepage_mitigation_hard_disabled; 620b210fafSSean Christopherson 63a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 644dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 65c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 66c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 67c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 68c50d8ae3SPaolo Bonzini #else 69c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 70c50d8ae3SPaolo Bonzini #endif 71c50d8ae3SPaolo Bonzini 720b210fafSSean Christopherson static int get_nx_huge_pages(char *buffer, const struct kernel_param *kp); 73c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 744dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 75c50d8ae3SPaolo Bonzini 76d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 77c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 780b210fafSSean Christopherson .get = get_nx_huge_pages, 79c50d8ae3SPaolo Bonzini }; 80c50d8ae3SPaolo Bonzini 814dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 824dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 83c50d8ae3SPaolo Bonzini .get = param_get_uint, 84c50d8ae3SPaolo Bonzini }; 85c50d8ae3SPaolo Bonzini 86c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 87c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 884dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 89c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 90c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 914dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 924dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 934dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 94c50d8ae3SPaolo Bonzini 9571fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9671fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9771fe7013SSean Christopherson 98c50d8ae3SPaolo Bonzini /* 99c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 100c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 101c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 102c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 103c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 104c50d8ae3SPaolo Bonzini */ 105c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 106c50d8ae3SPaolo Bonzini 1077f604e92SDavid Matlack static bool __ro_after_init tdp_mmu_allowed; 1081f98f2bdSDavid Matlack 1091f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 1101f98f2bdSDavid Matlack bool __read_mostly tdp_mmu_enabled = true; 1111f98f2bdSDavid Matlack module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0444); 1121f98f2bdSDavid Matlack #endif 1131f98f2bdSDavid Matlack 1141d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 115746700d2SWei Huang static int tdp_root_level __read_mostly; 11683013059SSean Christopherson static int max_tdp_level __read_mostly; 117703c335dSSean Christopherson 118c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 119c50d8ae3SPaolo Bonzini 120c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 121c50d8ae3SPaolo Bonzini 122dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 12313236e25SPeter Xu #define PTE_LIST_EXT 14 124c50d8ae3SPaolo Bonzini 12513236e25SPeter Xu /* 126141705b7SLai Jiangshan * struct pte_list_desc is the core data structure used to implement a custom 127141705b7SLai Jiangshan * list for tracking a set of related SPTEs, e.g. all the SPTEs that map a 128141705b7SLai Jiangshan * given GFN when used in the context of rmaps. Using a custom list allows KVM 129141705b7SLai Jiangshan * to optimize for the common case where many GFNs will have at most a handful 130141705b7SLai Jiangshan * of SPTEs pointing at them, i.e. allows packing multiple SPTEs into a small 131141705b7SLai Jiangshan * memory footprint, which in turn improves runtime performance by exploiting 132141705b7SLai Jiangshan * cache locality. 133141705b7SLai Jiangshan * 134141705b7SLai Jiangshan * A list is comprised of one or more pte_list_desc objects (descriptors). 135141705b7SLai Jiangshan * Each individual descriptor stores up to PTE_LIST_EXT SPTEs. If a descriptor 136141705b7SLai Jiangshan * is full and a new SPTEs needs to be added, a new descriptor is allocated and 137141705b7SLai Jiangshan * becomes the head of the list. This means that by definitions, all tail 138141705b7SLai Jiangshan * descriptors are full. 139141705b7SLai Jiangshan * 140141705b7SLai Jiangshan * Note, the meta data fields are deliberately placed at the start of the 141141705b7SLai Jiangshan * structure to optimize the cacheline layout; accessing the descriptor will 142141705b7SLai Jiangshan * touch only a single cacheline so long as @spte_count<=6 (or if only the 143141705b7SLai Jiangshan * descriptors metadata is accessed). 14413236e25SPeter Xu */ 145c50d8ae3SPaolo Bonzini struct pte_list_desc { 146c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 147141705b7SLai Jiangshan /* The number of PTEs stored in _this_ descriptor. */ 148141705b7SLai Jiangshan u32 spte_count; 149141705b7SLai Jiangshan /* The number of PTEs stored in all tails of this descriptor. */ 150141705b7SLai Jiangshan u32 tail_count; 15113236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 152c50d8ae3SPaolo Bonzini }; 153c50d8ae3SPaolo Bonzini 154c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 155c50d8ae3SPaolo Bonzini u64 addr; 156c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 157c50d8ae3SPaolo Bonzini u64 *sptep; 158c50d8ae3SPaolo Bonzini int level; 159c50d8ae3SPaolo Bonzini unsigned index; 160c50d8ae3SPaolo Bonzini }; 161c50d8ae3SPaolo Bonzini 162c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 163c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 164c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 165c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 166c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 167c50d8ae3SPaolo Bonzini 168c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 169c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 170c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 171c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 172c50d8ae3SPaolo Bonzini 173c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 174c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 175c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 176c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 177c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 178c50d8ae3SPaolo Bonzini 179c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 18002c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 181c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 182c50d8ae3SPaolo Bonzini 183c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 184c50d8ae3SPaolo Bonzini 185594e91a1SSean Christopherson struct kvm_mmu_role_regs { 186594e91a1SSean Christopherson const unsigned long cr0; 187594e91a1SSean Christopherson const unsigned long cr4; 188594e91a1SSean Christopherson const u64 efer; 189594e91a1SSean Christopherson }; 190594e91a1SSean Christopherson 191c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 192c50d8ae3SPaolo Bonzini #include "mmutrace.h" 193c50d8ae3SPaolo Bonzini 194594e91a1SSean Christopherson /* 195594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1967a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 197594e91a1SSean Christopherson * the single source of truth for the MMU's state. 198594e91a1SSean Christopherson */ 199594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 20082ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 20182ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 202594e91a1SSean Christopherson { \ 203594e91a1SSean Christopherson return !!(regs->reg & flag); \ 204594e91a1SSean Christopherson } 205594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 206594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 207594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 208594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 209594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 210594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 211594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 212594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 213594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 214594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 215594e91a1SSean Christopherson 21660667724SSean Christopherson /* 21760667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 21860667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 21960667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 22060667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 22160667724SSean Christopherson */ 22260667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2234ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 22460667724SSean Christopherson { \ 225e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 22660667724SSean Christopherson } 22760667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 22860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 22960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 23060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 23160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 23260667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 23360667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 23456b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 23560667724SSean Christopherson 236faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 237faf72962SPaolo Bonzini { 238faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 239faf72962SPaolo Bonzini } 240faf72962SPaolo Bonzini 241faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 242faf72962SPaolo Bonzini { 243faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 244faf72962SPaolo Bonzini } 245faf72962SPaolo Bonzini 246594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 247594e91a1SSean Christopherson { 248594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 249594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 250594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 251594e91a1SSean Christopherson .efer = vcpu->arch.efer, 252594e91a1SSean Christopherson }; 253594e91a1SSean Christopherson 254594e91a1SSean Christopherson return regs; 255594e91a1SSean Christopherson } 256c50d8ae3SPaolo Bonzini 2572fdcc1b3SPaolo Bonzini static unsigned long get_guest_cr3(struct kvm_vcpu *vcpu) 258c50d8ae3SPaolo Bonzini { 2592fdcc1b3SPaolo Bonzini return kvm_read_cr3(vcpu); 260c50d8ae3SPaolo Bonzini } 261c50d8ae3SPaolo Bonzini 2622fdcc1b3SPaolo Bonzini static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu, 2632fdcc1b3SPaolo Bonzini struct kvm_mmu *mmu) 264c50d8ae3SPaolo Bonzini { 2652fdcc1b3SPaolo Bonzini if (IS_ENABLED(CONFIG_RETPOLINE) && mmu->get_guest_pgd == get_guest_cr3) 2662fdcc1b3SPaolo Bonzini return kvm_read_cr3(vcpu); 267c50d8ae3SPaolo Bonzini 2682fdcc1b3SPaolo Bonzini return mmu->get_guest_pgd(vcpu); 2692fdcc1b3SPaolo Bonzini } 270c50d8ae3SPaolo Bonzini 2718a1300ffSSean Christopherson static inline bool kvm_available_flush_remote_tlbs_range(void) 272c50d8ae3SPaolo Bonzini { 2730277022aSSean Christopherson #if IS_ENABLED(CONFIG_HYPERV) 2748a1300ffSSean Christopherson return kvm_x86_ops.flush_remote_tlbs_range; 2750277022aSSean Christopherson #else 2760277022aSSean Christopherson return false; 2770277022aSSean Christopherson #endif 278c50d8ae3SPaolo Bonzini } 279c50d8ae3SPaolo Bonzini 2801b2dc736SHou Wenlong static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index); 2811b2dc736SHou Wenlong 2821b2dc736SHou Wenlong /* Flush the range of guest memory mapped by the given SPTE. */ 2831b2dc736SHou Wenlong static void kvm_flush_remote_tlbs_sptep(struct kvm *kvm, u64 *sptep) 2841b2dc736SHou Wenlong { 2851b2dc736SHou Wenlong struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2861b2dc736SHou Wenlong gfn_t gfn = kvm_mmu_page_get_gfn(sp, spte_index(sptep)); 2871b2dc736SHou Wenlong 2881b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 2891b2dc736SHou Wenlong } 2901b2dc736SHou Wenlong 2918f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2928f79b064SBen Gardon unsigned int access) 2938f79b064SBen Gardon { 294c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2958f79b064SBen Gardon 296c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 297c236d962SSean Christopherson mmu_spte_set(sptep, spte); 298c50d8ae3SPaolo Bonzini } 299c50d8ae3SPaolo Bonzini 300c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 301c50d8ae3SPaolo Bonzini { 302c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 303c50d8ae3SPaolo Bonzini 3048a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 305c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 306c50d8ae3SPaolo Bonzini 307c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 308c50d8ae3SPaolo Bonzini } 309c50d8ae3SPaolo Bonzini 310c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 311c50d8ae3SPaolo Bonzini { 312c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 313c50d8ae3SPaolo Bonzini } 314c50d8ae3SPaolo Bonzini 315c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 316c50d8ae3SPaolo Bonzini { 317c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 318c50d8ae3SPaolo Bonzini 319c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 320c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 321c50d8ae3SPaolo Bonzini return false; 322c50d8ae3SPaolo Bonzini 323c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 324c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 325c50d8ae3SPaolo Bonzini 326c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 327c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 328c50d8ae3SPaolo Bonzini } 329c50d8ae3SPaolo Bonzini 330c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 331c50d8ae3SPaolo Bonzini { 332c50d8ae3SPaolo Bonzini return 1; 333c50d8ae3SPaolo Bonzini } 334c50d8ae3SPaolo Bonzini 335c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 336c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 337c50d8ae3SPaolo Bonzini { 338c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 339c50d8ae3SPaolo Bonzini } 340c50d8ae3SPaolo Bonzini 341c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 342c50d8ae3SPaolo Bonzini { 343c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 344c50d8ae3SPaolo Bonzini } 345c50d8ae3SPaolo Bonzini 346c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 347c50d8ae3SPaolo Bonzini { 348c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 349c50d8ae3SPaolo Bonzini } 350c50d8ae3SPaolo Bonzini 351c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 352c50d8ae3SPaolo Bonzini { 353c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 354c50d8ae3SPaolo Bonzini } 355c50d8ae3SPaolo Bonzini #else 356c50d8ae3SPaolo Bonzini union split_spte { 357c50d8ae3SPaolo Bonzini struct { 358c50d8ae3SPaolo Bonzini u32 spte_low; 359c50d8ae3SPaolo Bonzini u32 spte_high; 360c50d8ae3SPaolo Bonzini }; 361c50d8ae3SPaolo Bonzini u64 spte; 362c50d8ae3SPaolo Bonzini }; 363c50d8ae3SPaolo Bonzini 364c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 365c50d8ae3SPaolo Bonzini { 36657354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 367c50d8ae3SPaolo Bonzini 368c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 369c50d8ae3SPaolo Bonzini return; 370c50d8ae3SPaolo Bonzini 371c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 372c50d8ae3SPaolo Bonzini smp_wmb(); 373c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 374c50d8ae3SPaolo Bonzini } 375c50d8ae3SPaolo Bonzini 376c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 377c50d8ae3SPaolo Bonzini { 378c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 379c50d8ae3SPaolo Bonzini 380c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 381c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 382c50d8ae3SPaolo Bonzini 383c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 384c50d8ae3SPaolo Bonzini 385c50d8ae3SPaolo Bonzini /* 386c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 387c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 388c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 389c50d8ae3SPaolo Bonzini */ 390c50d8ae3SPaolo Bonzini smp_wmb(); 391c50d8ae3SPaolo Bonzini 392c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 393c50d8ae3SPaolo Bonzini } 394c50d8ae3SPaolo Bonzini 395c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 396c50d8ae3SPaolo Bonzini { 397c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 398c50d8ae3SPaolo Bonzini 399c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 400c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 401c50d8ae3SPaolo Bonzini 402c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 403c50d8ae3SPaolo Bonzini 404c50d8ae3SPaolo Bonzini /* 405c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 406c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 407c50d8ae3SPaolo Bonzini */ 408c50d8ae3SPaolo Bonzini smp_wmb(); 409c50d8ae3SPaolo Bonzini 410c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 411c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 412c50d8ae3SPaolo Bonzini } 413c50d8ae3SPaolo Bonzini 414c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 415c50d8ae3SPaolo Bonzini { 416c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 417c50d8ae3SPaolo Bonzini 418c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 419c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 420c50d8ae3SPaolo Bonzini 421c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 422c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 423c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 424c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 425c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 426c50d8ae3SPaolo Bonzini 427c50d8ae3SPaolo Bonzini return orig.spte; 428c50d8ae3SPaolo Bonzini } 429c50d8ae3SPaolo Bonzini 430c50d8ae3SPaolo Bonzini /* 431c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 432c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 433c50d8ae3SPaolo Bonzini * 434aed02fe3SSean Christopherson * An spte tlb flush may be pending, because kvm_set_pte_rmap 435c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 436c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 437c50d8ae3SPaolo Bonzini * 438c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 439c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 440c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 441c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 442c50d8ae3SPaolo Bonzini * 443c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 444c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 445c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 446c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 447c50d8ae3SPaolo Bonzini */ 448c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 449c50d8ae3SPaolo Bonzini { 45057354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 451c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 452c50d8ae3SPaolo Bonzini int count; 453c50d8ae3SPaolo Bonzini 454c50d8ae3SPaolo Bonzini retry: 455c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 456c50d8ae3SPaolo Bonzini smp_rmb(); 457c50d8ae3SPaolo Bonzini 458c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 459c50d8ae3SPaolo Bonzini smp_rmb(); 460c50d8ae3SPaolo Bonzini 461c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 462c50d8ae3SPaolo Bonzini smp_rmb(); 463c50d8ae3SPaolo Bonzini 464c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 465c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 466c50d8ae3SPaolo Bonzini goto retry; 467c50d8ae3SPaolo Bonzini 468c50d8ae3SPaolo Bonzini return spte.spte; 469c50d8ae3SPaolo Bonzini } 470c50d8ae3SPaolo Bonzini #endif 471c50d8ae3SPaolo Bonzini 472c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 473c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 474c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 475c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 476c50d8ae3SPaolo Bonzini * the spte. 477c50d8ae3SPaolo Bonzini */ 478c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 479c50d8ae3SPaolo Bonzini { 48020ba462dSSean Christopherson WARN_ON_ONCE(is_shadow_present_pte(*sptep)); 481c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 482c50d8ae3SPaolo Bonzini } 483c50d8ae3SPaolo Bonzini 484c50d8ae3SPaolo Bonzini /* 485c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 486c50d8ae3SPaolo Bonzini * accessed/dirty status. 487c50d8ae3SPaolo Bonzini */ 488c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 489c50d8ae3SPaolo Bonzini { 490c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 491c50d8ae3SPaolo Bonzini 49220ba462dSSean Christopherson WARN_ON_ONCE(!is_shadow_present_pte(new_spte)); 493115111efSDavid Matlack check_spte_writable_invariants(new_spte); 494c50d8ae3SPaolo Bonzini 495c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 496c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 497c50d8ae3SPaolo Bonzini return old_spte; 498c50d8ae3SPaolo Bonzini } 499c50d8ae3SPaolo Bonzini 500c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 501c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 502c50d8ae3SPaolo Bonzini else 503c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 504c50d8ae3SPaolo Bonzini 50520ba462dSSean Christopherson WARN_ON_ONCE(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 506c50d8ae3SPaolo Bonzini 507c50d8ae3SPaolo Bonzini return old_spte; 508c50d8ae3SPaolo Bonzini } 509c50d8ae3SPaolo Bonzini 510c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 511c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 512c50d8ae3SPaolo Bonzini * 51302844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 51402844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 51502844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 516c50d8ae3SPaolo Bonzini * 517c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 518c50d8ae3SPaolo Bonzini */ 519c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 520c50d8ae3SPaolo Bonzini { 521c50d8ae3SPaolo Bonzini bool flush = false; 522c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 523c50d8ae3SPaolo Bonzini 524c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 525c50d8ae3SPaolo Bonzini return false; 526c50d8ae3SPaolo Bonzini 527c50d8ae3SPaolo Bonzini /* 528c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 529c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 530c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 531c50d8ae3SPaolo Bonzini */ 532706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 533c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 534c50d8ae3SPaolo Bonzini flush = true; 535c50d8ae3SPaolo Bonzini 536c50d8ae3SPaolo Bonzini /* 537c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 538c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 539c50d8ae3SPaolo Bonzini */ 540c50d8ae3SPaolo Bonzini 541c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 542c50d8ae3SPaolo Bonzini flush = true; 543c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 544c50d8ae3SPaolo Bonzini } 545c50d8ae3SPaolo Bonzini 546c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 547c50d8ae3SPaolo Bonzini flush = true; 548c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 549c50d8ae3SPaolo Bonzini } 550c50d8ae3SPaolo Bonzini 551c50d8ae3SPaolo Bonzini return flush; 552c50d8ae3SPaolo Bonzini } 553c50d8ae3SPaolo Bonzini 554c50d8ae3SPaolo Bonzini /* 555c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 556c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 557c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5587fa2a347SSean Christopherson * Returns the old PTE. 559c50d8ae3SPaolo Bonzini */ 56035d539c3SSean Christopherson static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 561c50d8ae3SPaolo Bonzini { 562c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 563c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 56471f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 565b14b2690SSean Christopherson struct page *page; 566c50d8ae3SPaolo Bonzini 56754eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 56854eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 569c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 570c50d8ae3SPaolo Bonzini else 571c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 572c50d8ae3SPaolo Bonzini 573c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5747fa2a347SSean Christopherson return old_spte; 575c50d8ae3SPaolo Bonzini 57671f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 57771f51d2cSMingwei Zhang 578c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 579c50d8ae3SPaolo Bonzini 580c50d8ae3SPaolo Bonzini /* 581b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 582b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 583b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 584b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 585c50d8ae3SPaolo Bonzini */ 586b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 58720ba462dSSean Christopherson WARN_ON_ONCE(page && !page_count(page)); 588c50d8ae3SPaolo Bonzini 589c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 590c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 591c50d8ae3SPaolo Bonzini 592c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 593c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 594c50d8ae3SPaolo Bonzini 5957fa2a347SSean Christopherson return old_spte; 596c50d8ae3SPaolo Bonzini } 597c50d8ae3SPaolo Bonzini 598c50d8ae3SPaolo Bonzini /* 599c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 600c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 601c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 602c50d8ae3SPaolo Bonzini */ 603c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 604c50d8ae3SPaolo Bonzini { 605c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 606c50d8ae3SPaolo Bonzini } 607c50d8ae3SPaolo Bonzini 608c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 609c50d8ae3SPaolo Bonzini { 610c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 611c50d8ae3SPaolo Bonzini } 612c50d8ae3SPaolo Bonzini 613c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 614c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 615c50d8ae3SPaolo Bonzini { 616c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 617c50d8ae3SPaolo Bonzini 618c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 619c50d8ae3SPaolo Bonzini return false; 620c50d8ae3SPaolo Bonzini 621c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 622c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 623c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 624c50d8ae3SPaolo Bonzini } else { 625c50d8ae3SPaolo Bonzini /* 626c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 627c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 628c50d8ae3SPaolo Bonzini */ 629c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 630c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 631c50d8ae3SPaolo Bonzini 632c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 633c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 634c50d8ae3SPaolo Bonzini } 635c50d8ae3SPaolo Bonzini 636c50d8ae3SPaolo Bonzini return true; 637c50d8ae3SPaolo Bonzini } 638c50d8ae3SPaolo Bonzini 63978fdd2f0SSean Christopherson static inline bool is_tdp_mmu_active(struct kvm_vcpu *vcpu) 64078fdd2f0SSean Christopherson { 64178fdd2f0SSean Christopherson return tdp_mmu_enabled && vcpu->arch.mmu->root_role.direct; 64278fdd2f0SSean Christopherson } 64378fdd2f0SSean Christopherson 644c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 645c50d8ae3SPaolo Bonzini { 64678fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 647c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 648c5c8c7c5SDavid Matlack } else { 649c50d8ae3SPaolo Bonzini /* 650c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 651c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 652c50d8ae3SPaolo Bonzini */ 653c50d8ae3SPaolo Bonzini local_irq_disable(); 654c50d8ae3SPaolo Bonzini 655c50d8ae3SPaolo Bonzini /* 656c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 657c50d8ae3SPaolo Bonzini * to vcpu->mode. 658c50d8ae3SPaolo Bonzini */ 659c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 660c50d8ae3SPaolo Bonzini } 661c5c8c7c5SDavid Matlack } 662c50d8ae3SPaolo Bonzini 663c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 664c50d8ae3SPaolo Bonzini { 66578fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 666c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 667c5c8c7c5SDavid Matlack } else { 668c50d8ae3SPaolo Bonzini /* 669c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 670c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 671c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 672c50d8ae3SPaolo Bonzini */ 673c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 674c50d8ae3SPaolo Bonzini local_irq_enable(); 675c50d8ae3SPaolo Bonzini } 676c5c8c7c5SDavid Matlack } 677c50d8ae3SPaolo Bonzini 678378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 679c50d8ae3SPaolo Bonzini { 680c50d8ae3SPaolo Bonzini int r; 681c50d8ae3SPaolo Bonzini 682531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 68394ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 684531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 685c50d8ae3SPaolo Bonzini if (r) 686c50d8ae3SPaolo Bonzini return r; 68794ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 688171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 689171a90d7SSean Christopherson if (r) 690171a90d7SSean Christopherson return r; 691378f5cd6SSean Christopherson if (maybe_indirect) { 6926a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 693171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 694c50d8ae3SPaolo Bonzini if (r) 695c50d8ae3SPaolo Bonzini return r; 696378f5cd6SSean Christopherson } 69794ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 698531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 699c50d8ae3SPaolo Bonzini } 700c50d8ae3SPaolo Bonzini 701c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 702c50d8ae3SPaolo Bonzini { 70394ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 70494ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 7056a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 70694ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 707c50d8ae3SPaolo Bonzini } 708c50d8ae3SPaolo Bonzini 709c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 710c50d8ae3SPaolo Bonzini { 711c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 712c50d8ae3SPaolo Bonzini } 713c50d8ae3SPaolo Bonzini 7146a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 7156a97575dSDavid Matlack 716c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 717c50d8ae3SPaolo Bonzini { 71884e5ffd0SLai Jiangshan if (sp->role.passthrough) 71984e5ffd0SLai Jiangshan return sp->gfn; 72084e5ffd0SLai Jiangshan 721c50d8ae3SPaolo Bonzini if (!sp->role.direct) 7226a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 723c50d8ae3SPaolo Bonzini 7242ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 725c50d8ae3SPaolo Bonzini } 726c50d8ae3SPaolo Bonzini 7276a97575dSDavid Matlack /* 7286a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 7296a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 7306a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 7316a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 7326a97575dSDavid Matlack */ 7336a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 734c50d8ae3SPaolo Bonzini { 7356a97575dSDavid Matlack if (sp_has_gptes(sp)) 7366a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7376a97575dSDavid Matlack 7386a97575dSDavid Matlack /* 7396a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7406a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7416a97575dSDavid Matlack * permissions" are just ACC_ALL. 7426a97575dSDavid Matlack * 7436a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7446a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7456a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7466a97575dSDavid Matlack * page. 7476a97575dSDavid Matlack * 7486a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7496a97575dSDavid Matlack */ 7506a97575dSDavid Matlack return sp->role.access; 7516a97575dSDavid Matlack } 7526a97575dSDavid Matlack 75372ae5822SSean Christopherson static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, 75472ae5822SSean Christopherson gfn_t gfn, unsigned int access) 7556a97575dSDavid Matlack { 7566a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7576a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 75884e5ffd0SLai Jiangshan return; 75984e5ffd0SLai Jiangshan } 76084e5ffd0SLai Jiangshan 7616a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7626a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7636a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7646a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7656a97575dSDavid Matlack 7666a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7676a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7686a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7696a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 770c50d8ae3SPaolo Bonzini } 771c50d8ae3SPaolo Bonzini 77272ae5822SSean Christopherson static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, 77372ae5822SSean Christopherson unsigned int access) 7746a97575dSDavid Matlack { 7756a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7766a97575dSDavid Matlack 7776a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 778c50d8ae3SPaolo Bonzini } 779c50d8ae3SPaolo Bonzini 780c50d8ae3SPaolo Bonzini /* 781c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 782c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 783c50d8ae3SPaolo Bonzini */ 784c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7858ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 786c50d8ae3SPaolo Bonzini { 787c50d8ae3SPaolo Bonzini unsigned long idx; 788c50d8ae3SPaolo Bonzini 789c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 790c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 791c50d8ae3SPaolo Bonzini } 792c50d8ae3SPaolo Bonzini 79390b4fe17SChao Peng /* 79490b4fe17SChao Peng * The most significant bit in disallow_lpage tracks whether or not memory 79590b4fe17SChao Peng * attributes are mixed, i.e. not identical for all gfns at the current level. 79690b4fe17SChao Peng * The lower order bits are used to refcount other cases where a hugepage is 79790b4fe17SChao Peng * disallowed, e.g. if KVM has shadow a page table at the gfn. 79890b4fe17SChao Peng */ 79990b4fe17SChao Peng #define KVM_LPAGE_MIXED_FLAG BIT(31) 80090b4fe17SChao Peng 801269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 802c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 803c50d8ae3SPaolo Bonzini { 804c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 80590b4fe17SChao Peng int old, i; 806c50d8ae3SPaolo Bonzini 8073bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 808c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 80990b4fe17SChao Peng 81090b4fe17SChao Peng old = linfo->disallow_lpage; 811c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 81290b4fe17SChao Peng WARN_ON_ONCE((old ^ linfo->disallow_lpage) & KVM_LPAGE_MIXED_FLAG); 813c50d8ae3SPaolo Bonzini } 814c50d8ae3SPaolo Bonzini } 815c50d8ae3SPaolo Bonzini 816269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 817c50d8ae3SPaolo Bonzini { 818c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 819c50d8ae3SPaolo Bonzini } 820c50d8ae3SPaolo Bonzini 821269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 822c50d8ae3SPaolo Bonzini { 823c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 824c50d8ae3SPaolo Bonzini } 825c50d8ae3SPaolo Bonzini 826c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 827c50d8ae3SPaolo Bonzini { 828c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 829c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 830c50d8ae3SPaolo Bonzini gfn_t gfn; 831c50d8ae3SPaolo Bonzini 832c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 833c50d8ae3SPaolo Bonzini gfn = sp->gfn; 834c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 835c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 836c50d8ae3SPaolo Bonzini 837c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8383bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 83996316a06SSean Christopherson return __kvm_write_track_add_gfn(kvm, slot, gfn); 840c50d8ae3SPaolo Bonzini 841c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 842be911771SDavid Matlack 843be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 8444ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, PG_LEVEL_4K); 845c50d8ae3SPaolo Bonzini } 846c50d8ae3SPaolo Bonzini 84761f94478SSean Christopherson void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 848c50d8ae3SPaolo Bonzini { 849428e9216SSean Christopherson /* 850428e9216SSean Christopherson * If it's possible to replace the shadow page with an NX huge page, 851428e9216SSean Christopherson * i.e. if the shadow page is the only thing currently preventing KVM 852428e9216SSean Christopherson * from using a huge page, add the shadow page to the list of "to be 853428e9216SSean Christopherson * zapped for NX recovery" pages. Note, the shadow page can already be 854428e9216SSean Christopherson * on the list if KVM is reusing an existing shadow page, i.e. if KVM 855428e9216SSean Christopherson * links a shadow page at multiple points. 856428e9216SSean Christopherson */ 85761f94478SSean Christopherson if (!list_empty(&sp->possible_nx_huge_page_link)) 858c50d8ae3SPaolo Bonzini return; 859c50d8ae3SPaolo Bonzini 860c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 86155c510e2SSean Christopherson list_add_tail(&sp->possible_nx_huge_page_link, 86255c510e2SSean Christopherson &kvm->arch.possible_nx_huge_pages); 863c50d8ae3SPaolo Bonzini } 864c50d8ae3SPaolo Bonzini 86561f94478SSean Christopherson static void account_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp, 86661f94478SSean Christopherson bool nx_huge_page_possible) 86761f94478SSean Christopherson { 86861f94478SSean Christopherson sp->nx_huge_page_disallowed = true; 86961f94478SSean Christopherson 87061f94478SSean Christopherson if (nx_huge_page_possible) 87161f94478SSean Christopherson track_possible_nx_huge_page(kvm, sp); 872c50d8ae3SPaolo Bonzini } 873c50d8ae3SPaolo Bonzini 874c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 875c50d8ae3SPaolo Bonzini { 876c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 877c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 878c50d8ae3SPaolo Bonzini gfn_t gfn; 879c50d8ae3SPaolo Bonzini 880c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 881c50d8ae3SPaolo Bonzini gfn = sp->gfn; 882c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 883c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8843bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 88596316a06SSean Christopherson return __kvm_write_track_remove_gfn(kvm, slot, gfn); 886c50d8ae3SPaolo Bonzini 887c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 888c50d8ae3SPaolo Bonzini } 889c50d8ae3SPaolo Bonzini 89061f94478SSean Christopherson void untrack_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 891c50d8ae3SPaolo Bonzini { 89255c510e2SSean Christopherson if (list_empty(&sp->possible_nx_huge_page_link)) 893428e9216SSean Christopherson return; 894428e9216SSean Christopherson 895c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 89655c510e2SSean Christopherson list_del_init(&sp->possible_nx_huge_page_link); 897c50d8ae3SPaolo Bonzini } 898c50d8ae3SPaolo Bonzini 89961f94478SSean Christopherson static void unaccount_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 90061f94478SSean Christopherson { 90161f94478SSean Christopherson sp->nx_huge_page_disallowed = false; 90261f94478SSean Christopherson 90361f94478SSean Christopherson untrack_possible_nx_huge_page(kvm, sp); 904c50d8ae3SPaolo Bonzini } 905c50d8ae3SPaolo Bonzini 906f3d90f90SSean Christopherson static struct kvm_memory_slot *gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, 907f3d90f90SSean Christopherson gfn_t gfn, 908c50d8ae3SPaolo Bonzini bool no_dirty_log) 909c50d8ae3SPaolo Bonzini { 910c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 911c50d8ae3SPaolo Bonzini 912c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 91391b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 91491b0d268SPaolo Bonzini return NULL; 915044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 91691b0d268SPaolo Bonzini return NULL; 917c50d8ae3SPaolo Bonzini 918c50d8ae3SPaolo Bonzini return slot; 919c50d8ae3SPaolo Bonzini } 920c50d8ae3SPaolo Bonzini 921c50d8ae3SPaolo Bonzini /* 922c50d8ae3SPaolo Bonzini * About rmap_head encoding: 923c50d8ae3SPaolo Bonzini * 924c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 925c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 926c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 927c50d8ae3SPaolo Bonzini */ 928c50d8ae3SPaolo Bonzini 929c50d8ae3SPaolo Bonzini /* 930c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 931c50d8ae3SPaolo Bonzini */ 9322ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 933c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 934c50d8ae3SPaolo Bonzini { 935c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 93613236e25SPeter Xu int count = 0; 937c50d8ae3SPaolo Bonzini 938c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 939c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 940c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 9412ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 942c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 943c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 94413236e25SPeter Xu desc->spte_count = 2; 945141705b7SLai Jiangshan desc->tail_count = 0; 946c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 947c50d8ae3SPaolo Bonzini ++count; 948c50d8ae3SPaolo Bonzini } else { 949c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 950141705b7SLai Jiangshan count = desc->tail_count + desc->spte_count; 951141705b7SLai Jiangshan 952141705b7SLai Jiangshan /* 953141705b7SLai Jiangshan * If the previous head is full, allocate a new head descriptor 954141705b7SLai Jiangshan * as tail descriptors are always kept full. 955141705b7SLai Jiangshan */ 956141705b7SLai Jiangshan if (desc->spte_count == PTE_LIST_EXT) { 957141705b7SLai Jiangshan desc = kvm_mmu_memory_cache_alloc(cache); 958141705b7SLai Jiangshan desc->more = (struct pte_list_desc *)(rmap_head->val & ~1ul); 95913236e25SPeter Xu desc->spte_count = 0; 960141705b7SLai Jiangshan desc->tail_count = count; 961141705b7SLai Jiangshan rmap_head->val = (unsigned long)desc | 1; 962c6c4f961SLi RongQing } 96313236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 964c50d8ae3SPaolo Bonzini } 965c50d8ae3SPaolo Bonzini return count; 966c50d8ae3SPaolo Bonzini } 967c50d8ae3SPaolo Bonzini 968069f30c6SMingwei Zhang static void pte_list_desc_remove_entry(struct kvm *kvm, 969069f30c6SMingwei Zhang struct kvm_rmap_head *rmap_head, 970141705b7SLai Jiangshan struct pte_list_desc *desc, int i) 971c50d8ae3SPaolo Bonzini { 972141705b7SLai Jiangshan struct pte_list_desc *head_desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 973141705b7SLai Jiangshan int j = head_desc->spte_count - 1; 974c50d8ae3SPaolo Bonzini 975141705b7SLai Jiangshan /* 976141705b7SLai Jiangshan * The head descriptor should never be empty. A new head is added only 977141705b7SLai Jiangshan * when adding an entry and the previous head is full, and heads are 978141705b7SLai Jiangshan * removed (this flow) when they become empty. 979141705b7SLai Jiangshan */ 98052e322edSSean Christopherson KVM_BUG_ON_DATA_CORRUPTION(j < 0, kvm); 981141705b7SLai Jiangshan 982141705b7SLai Jiangshan /* 983141705b7SLai Jiangshan * Replace the to-be-freed SPTE with the last valid entry from the head 984141705b7SLai Jiangshan * descriptor to ensure that tail descriptors are full at all times. 985141705b7SLai Jiangshan * Note, this also means that tail_count is stable for each descriptor. 986141705b7SLai Jiangshan */ 987141705b7SLai Jiangshan desc->sptes[i] = head_desc->sptes[j]; 988141705b7SLai Jiangshan head_desc->sptes[j] = NULL; 989141705b7SLai Jiangshan head_desc->spte_count--; 990141705b7SLai Jiangshan if (head_desc->spte_count) 991c50d8ae3SPaolo Bonzini return; 992141705b7SLai Jiangshan 993141705b7SLai Jiangshan /* 994141705b7SLai Jiangshan * The head descriptor is empty. If there are no tail descriptors, 99554aa699eSBjorn Helgaas * nullify the rmap head to mark the list as empty, else point the rmap 996141705b7SLai Jiangshan * head at the next descriptor, i.e. the new head. 997141705b7SLai Jiangshan */ 998141705b7SLai Jiangshan if (!head_desc->more) 999fe3c2b4cSMiaohe Lin rmap_head->val = 0; 1000c50d8ae3SPaolo Bonzini else 1001141705b7SLai Jiangshan rmap_head->val = (unsigned long)head_desc->more | 1; 1002141705b7SLai Jiangshan mmu_free_pte_list_desc(head_desc); 1003c50d8ae3SPaolo Bonzini } 1004c50d8ae3SPaolo Bonzini 1005069f30c6SMingwei Zhang static void pte_list_remove(struct kvm *kvm, u64 *spte, 1006069f30c6SMingwei Zhang struct kvm_rmap_head *rmap_head) 1007c50d8ae3SPaolo Bonzini { 1008c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 1009c50d8ae3SPaolo Bonzini int i; 1010c50d8ae3SPaolo Bonzini 101152e322edSSean Christopherson if (KVM_BUG_ON_DATA_CORRUPTION(!rmap_head->val, kvm)) 101252e322edSSean Christopherson return; 101352e322edSSean Christopherson 101452e322edSSean Christopherson if (!(rmap_head->val & 1)) { 101552e322edSSean Christopherson if (KVM_BUG_ON_DATA_CORRUPTION((u64 *)rmap_head->val != spte, kvm)) 101652e322edSSean Christopherson return; 101752e322edSSean Christopherson 1018c50d8ae3SPaolo Bonzini rmap_head->val = 0; 1019c50d8ae3SPaolo Bonzini } else { 1020c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1021c50d8ae3SPaolo Bonzini while (desc) { 102213236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 1023c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 1024069f30c6SMingwei Zhang pte_list_desc_remove_entry(kvm, rmap_head, 1025069f30c6SMingwei Zhang desc, i); 1026c50d8ae3SPaolo Bonzini return; 1027c50d8ae3SPaolo Bonzini } 1028c50d8ae3SPaolo Bonzini } 1029c50d8ae3SPaolo Bonzini desc = desc->more; 1030c50d8ae3SPaolo Bonzini } 103152e322edSSean Christopherson 103252e322edSSean Christopherson KVM_BUG_ON_DATA_CORRUPTION(true, kvm); 1033c50d8ae3SPaolo Bonzini } 1034c50d8ae3SPaolo Bonzini } 1035c50d8ae3SPaolo Bonzini 10369202aee8SSean Christopherson static void kvm_zap_one_rmap_spte(struct kvm *kvm, 10379202aee8SSean Christopherson struct kvm_rmap_head *rmap_head, u64 *sptep) 1038c50d8ae3SPaolo Bonzini { 103971f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1040069f30c6SMingwei Zhang pte_list_remove(kvm, sptep, rmap_head); 1041c50d8ae3SPaolo Bonzini } 1042c50d8ae3SPaolo Bonzini 10439202aee8SSean Christopherson /* Return true if at least one SPTE was zapped, false otherwise */ 10449202aee8SSean Christopherson static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 10459202aee8SSean Christopherson struct kvm_rmap_head *rmap_head) 1046a75b5404SPeter Xu { 1047a75b5404SPeter Xu struct pte_list_desc *desc, *next; 1048a75b5404SPeter Xu int i; 1049a75b5404SPeter Xu 1050a75b5404SPeter Xu if (!rmap_head->val) 1051a75b5404SPeter Xu return false; 1052a75b5404SPeter Xu 1053a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 105471f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 1055a75b5404SPeter Xu goto out; 1056a75b5404SPeter Xu } 1057a75b5404SPeter Xu 1058a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1059a75b5404SPeter Xu 1060a75b5404SPeter Xu for (; desc; desc = next) { 1061a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 106271f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 1063a75b5404SPeter Xu next = desc->more; 1064a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 1065a75b5404SPeter Xu } 1066a75b5404SPeter Xu out: 1067a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 1068a75b5404SPeter Xu rmap_head->val = 0; 1069a75b5404SPeter Xu return true; 1070a75b5404SPeter Xu } 1071a75b5404SPeter Xu 10723bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10733bcd0662SPeter Xu { 10743bcd0662SPeter Xu struct pte_list_desc *desc; 10753bcd0662SPeter Xu 10763bcd0662SPeter Xu if (!rmap_head->val) 10773bcd0662SPeter Xu return 0; 10783bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10793bcd0662SPeter Xu return 1; 10803bcd0662SPeter Xu 10813bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1082141705b7SLai Jiangshan return desc->tail_count + desc->spte_count; 10833bcd0662SPeter Xu } 10843bcd0662SPeter Xu 108593e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1086269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1087c50d8ae3SPaolo Bonzini { 1088c50d8ae3SPaolo Bonzini unsigned long idx; 1089c50d8ae3SPaolo Bonzini 1090c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10913bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1092c50d8ae3SPaolo Bonzini } 1093c50d8ae3SPaolo Bonzini 1094c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1095c50d8ae3SPaolo Bonzini { 1096601f8af0SDavid Matlack struct kvm_memslots *slots; 1097601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1098c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1099c50d8ae3SPaolo Bonzini gfn_t gfn; 1100c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1101c50d8ae3SPaolo Bonzini 110257354682SSean Christopherson sp = sptep_to_sp(spte); 110379e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(spte)); 1104601f8af0SDavid Matlack 1105601f8af0SDavid Matlack /* 110668be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 110768be1306SDavid Matlack * so we have to determine which memslots to use based on context 110868be1306SDavid Matlack * information in sp->role. 1109601f8af0SDavid Matlack */ 1110601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1111601f8af0SDavid Matlack 1112601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 111393e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1114601f8af0SDavid Matlack 1115069f30c6SMingwei Zhang pte_list_remove(kvm, spte, rmap_head); 1116c50d8ae3SPaolo Bonzini } 1117c50d8ae3SPaolo Bonzini 1118c50d8ae3SPaolo Bonzini /* 1119c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1120c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1121c50d8ae3SPaolo Bonzini */ 1122c50d8ae3SPaolo Bonzini struct rmap_iterator { 1123c50d8ae3SPaolo Bonzini /* private fields */ 1124c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1125c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1126c50d8ae3SPaolo Bonzini }; 1127c50d8ae3SPaolo Bonzini 1128c50d8ae3SPaolo Bonzini /* 1129c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1130c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 11310a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1132c50d8ae3SPaolo Bonzini * 1133c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1134c50d8ae3SPaolo Bonzini */ 1135c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1136c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1137c50d8ae3SPaolo Bonzini { 1138c50d8ae3SPaolo Bonzini u64 *sptep; 1139c50d8ae3SPaolo Bonzini 1140c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1141c50d8ae3SPaolo Bonzini return NULL; 1142c50d8ae3SPaolo Bonzini 1143c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1144c50d8ae3SPaolo Bonzini iter->desc = NULL; 1145c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1146c50d8ae3SPaolo Bonzini goto out; 1147c50d8ae3SPaolo Bonzini } 1148c50d8ae3SPaolo Bonzini 1149c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1150c50d8ae3SPaolo Bonzini iter->pos = 0; 1151c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1152c50d8ae3SPaolo Bonzini out: 1153c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1154c50d8ae3SPaolo Bonzini return sptep; 1155c50d8ae3SPaolo Bonzini } 1156c50d8ae3SPaolo Bonzini 1157c50d8ae3SPaolo Bonzini /* 1158c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1159c50d8ae3SPaolo Bonzini * 1160c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1161c50d8ae3SPaolo Bonzini */ 1162c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1163c50d8ae3SPaolo Bonzini { 1164c50d8ae3SPaolo Bonzini u64 *sptep; 1165c50d8ae3SPaolo Bonzini 1166c50d8ae3SPaolo Bonzini if (iter->desc) { 1167c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1168c50d8ae3SPaolo Bonzini ++iter->pos; 1169c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1170c50d8ae3SPaolo Bonzini if (sptep) 1171c50d8ae3SPaolo Bonzini goto out; 1172c50d8ae3SPaolo Bonzini } 1173c50d8ae3SPaolo Bonzini 1174c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1175c50d8ae3SPaolo Bonzini 1176c50d8ae3SPaolo Bonzini if (iter->desc) { 1177c50d8ae3SPaolo Bonzini iter->pos = 0; 1178c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1179c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1180c50d8ae3SPaolo Bonzini goto out; 1181c50d8ae3SPaolo Bonzini } 1182c50d8ae3SPaolo Bonzini } 1183c50d8ae3SPaolo Bonzini 1184c50d8ae3SPaolo Bonzini return NULL; 1185c50d8ae3SPaolo Bonzini out: 1186c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1187c50d8ae3SPaolo Bonzini return sptep; 1188c50d8ae3SPaolo Bonzini } 1189c50d8ae3SPaolo Bonzini 1190c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1191c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1192c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1193c50d8ae3SPaolo Bonzini 1194c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1195c50d8ae3SPaolo Bonzini { 119671f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11977fa2a347SSean Christopherson 11987fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1199c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1200c50d8ae3SPaolo Bonzini } 1201c50d8ae3SPaolo Bonzini 120203787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1203c50d8ae3SPaolo Bonzini { 12040cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 12050cd8dc73SPaolo Bonzini 12060cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 120720ba462dSSean Christopherson WARN_ON_ONCE(sp->role.level == PG_LEVEL_4K); 12080cd8dc73SPaolo Bonzini 1209c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 121003787394SPaolo Bonzini 121103787394SPaolo Bonzini if (flush) 12121b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 1213c50d8ae3SPaolo Bonzini } 1214c50d8ae3SPaolo Bonzini 1215c50d8ae3SPaolo Bonzini /* 1216c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1217c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1218c50d8ae3SPaolo Bonzini * 1219c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1220c50d8ae3SPaolo Bonzini * protection: 1221c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1222c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1223c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1224c50d8ae3SPaolo Bonzini * shadow page. 1225c50d8ae3SPaolo Bonzini * 1226c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1227c50d8ae3SPaolo Bonzini */ 1228c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1229c50d8ae3SPaolo Bonzini { 1230c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1231c50d8ae3SPaolo Bonzini 1232c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1233706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1234c50d8ae3SPaolo Bonzini return false; 1235c50d8ae3SPaolo Bonzini 1236c50d8ae3SPaolo Bonzini if (pt_protect) 12375fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1238c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1239c50d8ae3SPaolo Bonzini 1240c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1241c50d8ae3SPaolo Bonzini } 1242c50d8ae3SPaolo Bonzini 12431346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1244c50d8ae3SPaolo Bonzini bool pt_protect) 1245c50d8ae3SPaolo Bonzini { 1246c50d8ae3SPaolo Bonzini u64 *sptep; 1247c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1248c50d8ae3SPaolo Bonzini bool flush = false; 1249c50d8ae3SPaolo Bonzini 1250c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1251c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1252c50d8ae3SPaolo Bonzini 1253c50d8ae3SPaolo Bonzini return flush; 1254c50d8ae3SPaolo Bonzini } 1255c50d8ae3SPaolo Bonzini 1256c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1257c50d8ae3SPaolo Bonzini { 1258c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1259c50d8ae3SPaolo Bonzini 12600fe6370eSSean Christopherson KVM_MMU_WARN_ON(!spte_ad_enabled(spte)); 1261c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1262c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1263c50d8ae3SPaolo Bonzini } 1264c50d8ae3SPaolo Bonzini 1265c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1266c50d8ae3SPaolo Bonzini { 1267c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1268c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1269c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1270c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1271c50d8ae3SPaolo Bonzini 1272c50d8ae3SPaolo Bonzini return was_writable; 1273c50d8ae3SPaolo Bonzini } 1274c50d8ae3SPaolo Bonzini 1275c50d8ae3SPaolo Bonzini /* 1276c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1277c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1278c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1279c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1280c50d8ae3SPaolo Bonzini */ 12810a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1282269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1283c50d8ae3SPaolo Bonzini { 1284c50d8ae3SPaolo Bonzini u64 *sptep; 1285c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1286c50d8ae3SPaolo Bonzini bool flush = false; 1287c50d8ae3SPaolo Bonzini 1288c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1289c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1290c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1291c50d8ae3SPaolo Bonzini else 1292c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1293c50d8ae3SPaolo Bonzini 1294c50d8ae3SPaolo Bonzini return flush; 1295c50d8ae3SPaolo Bonzini } 1296c50d8ae3SPaolo Bonzini 1297c50d8ae3SPaolo Bonzini /** 1298c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1299c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1300c50d8ae3SPaolo Bonzini * @slot: slot to protect 1301c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1302c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1303c50d8ae3SPaolo Bonzini * 130489212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1305c50d8ae3SPaolo Bonzini */ 1306c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1307c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1308c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1309c50d8ae3SPaolo Bonzini { 1310c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1311c50d8ae3SPaolo Bonzini 13121f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1313a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1314a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1315e2209710SBen Gardon 1316e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1317e2209710SBen Gardon return; 1318e2209710SBen Gardon 1319c50d8ae3SPaolo Bonzini while (mask) { 132093e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13213bae0459SSean Christopherson PG_LEVEL_4K, slot); 13221346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1323c50d8ae3SPaolo Bonzini 1324c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1325c50d8ae3SPaolo Bonzini mask &= mask - 1; 1326c50d8ae3SPaolo Bonzini } 1327c50d8ae3SPaolo Bonzini } 1328c50d8ae3SPaolo Bonzini 1329c50d8ae3SPaolo Bonzini /** 1330c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1331c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1332c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1333c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1334c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1335c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1336c50d8ae3SPaolo Bonzini * 1337c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1338c50d8ae3SPaolo Bonzini */ 1339a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1340c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1341c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1342c50d8ae3SPaolo Bonzini { 1343c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1344c50d8ae3SPaolo Bonzini 13451f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1346a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1347a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1348e2209710SBen Gardon 1349e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1350e2209710SBen Gardon return; 1351e2209710SBen Gardon 1352c50d8ae3SPaolo Bonzini while (mask) { 135393e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13543bae0459SSean Christopherson PG_LEVEL_4K, slot); 13550a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1356c50d8ae3SPaolo Bonzini 1357c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1358c50d8ae3SPaolo Bonzini mask &= mask - 1; 1359c50d8ae3SPaolo Bonzini } 1360c50d8ae3SPaolo Bonzini } 1361c50d8ae3SPaolo Bonzini 1362c50d8ae3SPaolo Bonzini /** 1363c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1364c50d8ae3SPaolo Bonzini * PT level pages. 1365c50d8ae3SPaolo Bonzini * 1366c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1367c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1368c50d8ae3SPaolo Bonzini * 136989212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 137089212919SKeqian Zhu * have such mappings. 1371c50d8ae3SPaolo Bonzini */ 1372c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1373c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1374c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1375c50d8ae3SPaolo Bonzini { 137689212919SKeqian Zhu /* 137789212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 137889212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 137989212919SKeqian Zhu * are split to 4K on the first write. 138089212919SKeqian Zhu * 138189212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 138289212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 138389212919SKeqian Zhu * pages. 138489212919SKeqian Zhu */ 138589212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 138689212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 138789212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 138889212919SKeqian Zhu 1389cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 13901aa4bb91SDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end + 1, PG_LEVEL_4K); 1391cb00a70bSDavid Matlack 139289212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 139389212919SKeqian Zhu 139489212919SKeqian Zhu /* Cross two large pages? */ 139589212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 139689212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 139789212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 139889212919SKeqian Zhu PG_LEVEL_2M); 139989212919SKeqian Zhu } 140089212919SKeqian Zhu 140189212919SKeqian Zhu /* Now handle 4K PTEs. */ 1402a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1403a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1404c50d8ae3SPaolo Bonzini else 1405c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1406c50d8ae3SPaolo Bonzini } 1407c50d8ae3SPaolo Bonzini 1408fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1409fb04a1edSPeter Xu { 14106dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1411fb04a1edSPeter Xu } 1412fb04a1edSPeter Xu 1413c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 14143ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 14153ad93562SKeqian Zhu int min_level) 1416c50d8ae3SPaolo Bonzini { 1417c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1418c50d8ae3SPaolo Bonzini int i; 1419c50d8ae3SPaolo Bonzini bool write_protected = false; 1420c50d8ae3SPaolo Bonzini 1421e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 14223ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 142393e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 14241346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1425c50d8ae3SPaolo Bonzini } 1426e2209710SBen Gardon } 1427c50d8ae3SPaolo Bonzini 14281f98f2bdSDavid Matlack if (tdp_mmu_enabled) 142946044f72SBen Gardon write_protected |= 14303ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 143146044f72SBen Gardon 1432c50d8ae3SPaolo Bonzini return write_protected; 1433c50d8ae3SPaolo Bonzini } 1434c50d8ae3SPaolo Bonzini 1435cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1436c50d8ae3SPaolo Bonzini { 1437c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1438c50d8ae3SPaolo Bonzini 1439c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 14403ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1441c50d8ae3SPaolo Bonzini } 1442c50d8ae3SPaolo Bonzini 1443f8480721SSean Christopherson static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1444269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1445c50d8ae3SPaolo Bonzini { 14469202aee8SSean Christopherson return kvm_zap_all_rmap_sptes(kvm, rmap_head); 1447c50d8ae3SPaolo Bonzini } 1448c50d8ae3SPaolo Bonzini 1449f8480721SSean Christopherson static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1450c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14513039bcc7SSean Christopherson pte_t unused) 1452c50d8ae3SPaolo Bonzini { 1453f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1454c50d8ae3SPaolo Bonzini } 1455c50d8ae3SPaolo Bonzini 1456aed02fe3SSean Christopherson static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1457c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14583039bcc7SSean Christopherson pte_t pte) 1459c50d8ae3SPaolo Bonzini { 1460c50d8ae3SPaolo Bonzini u64 *sptep; 1461c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 146298a26b69SVihas Mak bool need_flush = false; 1463c50d8ae3SPaolo Bonzini u64 new_spte; 1464c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1465c50d8ae3SPaolo Bonzini 146620ba462dSSean Christopherson WARN_ON_ONCE(pte_huge(pte)); 14673039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1468c50d8ae3SPaolo Bonzini 1469c50d8ae3SPaolo Bonzini restart: 1470c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 147198a26b69SVihas Mak need_flush = true; 1472c50d8ae3SPaolo Bonzini 14733039bcc7SSean Christopherson if (pte_write(pte)) { 14749202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 1475c50d8ae3SPaolo Bonzini goto restart; 1476c50d8ae3SPaolo Bonzini } else { 1477cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1478cb3eedabSPaolo Bonzini *sptep, new_pfn); 1479c50d8ae3SPaolo Bonzini 148071f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1481c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1482c50d8ae3SPaolo Bonzini } 1483c50d8ae3SPaolo Bonzini } 1484c50d8ae3SPaolo Bonzini 14858a1300ffSSean Christopherson if (need_flush && kvm_available_flush_remote_tlbs_range()) { 14869ffe9265SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, level); 148798a26b69SVihas Mak return false; 1488c50d8ae3SPaolo Bonzini } 1489c50d8ae3SPaolo Bonzini 1490c50d8ae3SPaolo Bonzini return need_flush; 1491c50d8ae3SPaolo Bonzini } 1492c50d8ae3SPaolo Bonzini 1493c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1494c50d8ae3SPaolo Bonzini /* input fields. */ 1495269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1496c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1497c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1498c50d8ae3SPaolo Bonzini int start_level; 1499c50d8ae3SPaolo Bonzini int end_level; 1500c50d8ae3SPaolo Bonzini 1501c50d8ae3SPaolo Bonzini /* output fields. */ 1502c50d8ae3SPaolo Bonzini gfn_t gfn; 1503c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1504c50d8ae3SPaolo Bonzini int level; 1505c50d8ae3SPaolo Bonzini 1506c50d8ae3SPaolo Bonzini /* private field. */ 1507c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1508c50d8ae3SPaolo Bonzini }; 1509c50d8ae3SPaolo Bonzini 1510f3d90f90SSean Christopherson static void rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, 1511f3d90f90SSean Christopherson int level) 1512c50d8ae3SPaolo Bonzini { 1513c50d8ae3SPaolo Bonzini iterator->level = level; 1514c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 151593e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 151693e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1517c50d8ae3SPaolo Bonzini } 1518c50d8ae3SPaolo Bonzini 1519f3d90f90SSean Christopherson static void slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1520f3d90f90SSean Christopherson const struct kvm_memory_slot *slot, 1521f3d90f90SSean Christopherson int start_level, int end_level, 1522f3d90f90SSean Christopherson gfn_t start_gfn, gfn_t end_gfn) 1523c50d8ae3SPaolo Bonzini { 1524c50d8ae3SPaolo Bonzini iterator->slot = slot; 1525c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1526c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1527c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1528c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1529c50d8ae3SPaolo Bonzini 1530c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1531c50d8ae3SPaolo Bonzini } 1532c50d8ae3SPaolo Bonzini 1533c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1534c50d8ae3SPaolo Bonzini { 1535c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1536c50d8ae3SPaolo Bonzini } 1537c50d8ae3SPaolo Bonzini 1538c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1539c50d8ae3SPaolo Bonzini { 15406ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1541c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 15426ba1e04fSVipin Sharma 15436ba1e04fSVipin Sharma if (iterator->rmap->val) 1544c50d8ae3SPaolo Bonzini return; 1545c50d8ae3SPaolo Bonzini } 1546c50d8ae3SPaolo Bonzini 1547c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1548c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1549c50d8ae3SPaolo Bonzini return; 1550c50d8ae3SPaolo Bonzini } 1551c50d8ae3SPaolo Bonzini 1552c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1553c50d8ae3SPaolo Bonzini } 1554c50d8ae3SPaolo Bonzini 1555c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1556c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1557c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1558c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1559c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1560c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1561c50d8ae3SPaolo Bonzini 15623039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1563c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15643039bcc7SSean Christopherson int level, pte_t pte); 1565c1b91493SSean Christopherson 15663039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15673039bcc7SSean Christopherson struct kvm_gfn_range *range, 1568c1b91493SSean Christopherson rmap_handler_t handler) 1569c50d8ae3SPaolo Bonzini { 1570c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15713039bcc7SSean Christopherson bool ret = false; 1572c50d8ae3SPaolo Bonzini 15733039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15743039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15753039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15763e1efe2bSSean Christopherson iterator.level, range->arg.pte); 1577c50d8ae3SPaolo Bonzini 1578c50d8ae3SPaolo Bonzini return ret; 1579c50d8ae3SPaolo Bonzini } 1580c50d8ae3SPaolo Bonzini 15813039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1582c50d8ae3SPaolo Bonzini { 1583e2209710SBen Gardon bool flush = false; 1584c50d8ae3SPaolo Bonzini 1585e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1586f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1587063afacdSBen Gardon 15881f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1589c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1590063afacdSBen Gardon 15910a3869e1SSean Christopherson if (kvm_x86_ops.set_apic_access_page_addr && 15920a3869e1SSean Christopherson range->slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT) 15930a8a5f2cSSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); 15940a8a5f2cSSean Christopherson 15953039bcc7SSean Christopherson return flush; 1596c50d8ae3SPaolo Bonzini } 1597c50d8ae3SPaolo Bonzini 15983039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1599c50d8ae3SPaolo Bonzini { 1600e2209710SBen Gardon bool flush = false; 16011d8dd6b3SBen Gardon 1602e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1603aed02fe3SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); 16041d8dd6b3SBen Gardon 16051f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16063039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 16071d8dd6b3SBen Gardon 16083039bcc7SSean Christopherson return flush; 1609c50d8ae3SPaolo Bonzini } 1610c50d8ae3SPaolo Bonzini 1611aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1612c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 16133039bcc7SSean Christopherson pte_t unused) 1614c50d8ae3SPaolo Bonzini { 1615c50d8ae3SPaolo Bonzini u64 *sptep; 16163f649ab7SKees Cook struct rmap_iterator iter; 1617c50d8ae3SPaolo Bonzini int young = 0; 1618c50d8ae3SPaolo Bonzini 1619c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1620c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1621c50d8ae3SPaolo Bonzini 1622c50d8ae3SPaolo Bonzini return young; 1623c50d8ae3SPaolo Bonzini } 1624c50d8ae3SPaolo Bonzini 1625aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1626c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 16273039bcc7SSean Christopherson int level, pte_t unused) 1628c50d8ae3SPaolo Bonzini { 1629c50d8ae3SPaolo Bonzini u64 *sptep; 1630c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1631c50d8ae3SPaolo Bonzini 1632c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1633c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 163498a26b69SVihas Mak return true; 163598a26b69SVihas Mak return false; 1636c50d8ae3SPaolo Bonzini } 1637c50d8ae3SPaolo Bonzini 1638c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1639c50d8ae3SPaolo Bonzini 16402ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 16412ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 16422ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 164372ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1644c50d8ae3SPaolo Bonzini { 1645c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 164668be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 164768be1306SDavid Matlack int rmap_count; 1648c50d8ae3SPaolo Bonzini 164957354682SSean Christopherson sp = sptep_to_sp(spte); 165079e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 165181cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 165281cb4657SDavid Matlack 165393e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 16542ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1655c50d8ae3SPaolo Bonzini 1656604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1657604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 165868be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16599202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 16601b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 166168be1306SDavid Matlack } 1662c50d8ae3SPaolo Bonzini } 1663c50d8ae3SPaolo Bonzini 16642ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 166572ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16662ff9039aSDavid Matlack { 16672ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16682ff9039aSDavid Matlack 16696a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16702ff9039aSDavid Matlack } 16712ff9039aSDavid Matlack 16723039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1673c50d8ae3SPaolo Bonzini { 1674e2209710SBen Gardon bool young = false; 1675f8e14497SBen Gardon 1676e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1677aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16783039bcc7SSean Christopherson 16791f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16803039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1681f8e14497SBen Gardon 1682f8e14497SBen Gardon return young; 1683c50d8ae3SPaolo Bonzini } 1684c50d8ae3SPaolo Bonzini 16853039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1686c50d8ae3SPaolo Bonzini { 1687e2209710SBen Gardon bool young = false; 1688f8e14497SBen Gardon 1689e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1690aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 16913039bcc7SSean Christopherson 16921f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16933039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1694f8e14497SBen Gardon 1695f8e14497SBen Gardon return young; 1696c50d8ae3SPaolo Bonzini } 1697c50d8ae3SPaolo Bonzini 169858da926cSSean Christopherson static void kvm_mmu_check_sptes_at_free(struct kvm_mmu_page *sp) 1699c50d8ae3SPaolo Bonzini { 1700870d4d4eSSean Christopherson #ifdef CONFIG_KVM_PROVE_MMU 1701242a6dd8SSean Christopherson int i; 1702c50d8ae3SPaolo Bonzini 1703242a6dd8SSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 17040fe6370eSSean Christopherson if (KVM_MMU_WARN_ON(is_shadow_present_pte(sp->spt[i]))) 170558da926cSSean Christopherson pr_err_ratelimited("SPTE %llx (@ %p) for gfn %llx shadow-present at free", 170658da926cSSean Christopherson sp->spt[i], &sp->spt[i], 170758da926cSSean Christopherson kvm_mmu_page_get_gfn(sp, i)); 1708c50d8ae3SPaolo Bonzini } 1709c50d8ae3SPaolo Bonzini #endif 171058da926cSSean Christopherson } 1711c50d8ae3SPaolo Bonzini 1712c50d8ae3SPaolo Bonzini /* 1713c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1714c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1715c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1716c50d8ae3SPaolo Bonzini * faster 1717c50d8ae3SPaolo Bonzini */ 1718d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1719c50d8ae3SPaolo Bonzini { 1720c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1721c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1722c50d8ae3SPaolo Bonzini } 1723c50d8ae3SPaolo Bonzini 172443a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 172543a063caSYosry Ahmed { 172643a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 172743a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 172843a063caSYosry Ahmed } 172943a063caSYosry Ahmed 173043a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 173143a063caSYosry Ahmed { 173243a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 173343a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 173443a063caSYosry Ahmed } 173543a063caSYosry Ahmed 173687654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1737c50d8ae3SPaolo Bonzini { 173858da926cSSean Christopherson kvm_mmu_check_sptes_at_free(sp); 173958da926cSSean Christopherson 1740c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1741c50d8ae3SPaolo Bonzini list_del(&sp->link); 1742c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1743c50d8ae3SPaolo Bonzini if (!sp->role.direct) 17446a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1745c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1746c50d8ae3SPaolo Bonzini } 1747c50d8ae3SPaolo Bonzini 1748c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1749c50d8ae3SPaolo Bonzini { 1750c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1751c50d8ae3SPaolo Bonzini } 1752c50d8ae3SPaolo Bonzini 17532ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1754c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1755c50d8ae3SPaolo Bonzini { 1756c50d8ae3SPaolo Bonzini if (!parent_pte) 1757c50d8ae3SPaolo Bonzini return; 1758c50d8ae3SPaolo Bonzini 17592ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1760c50d8ae3SPaolo Bonzini } 1761c50d8ae3SPaolo Bonzini 1762069f30c6SMingwei Zhang static void mmu_page_remove_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 1763c50d8ae3SPaolo Bonzini u64 *parent_pte) 1764c50d8ae3SPaolo Bonzini { 1765069f30c6SMingwei Zhang pte_list_remove(kvm, parent_pte, &sp->parent_ptes); 1766c50d8ae3SPaolo Bonzini } 1767c50d8ae3SPaolo Bonzini 1768069f30c6SMingwei Zhang static void drop_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 1769c50d8ae3SPaolo Bonzini u64 *parent_pte) 1770c50d8ae3SPaolo Bonzini { 1771069f30c6SMingwei Zhang mmu_page_remove_parent_pte(kvm, sp, parent_pte); 1772c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1773c50d8ae3SPaolo Bonzini } 1774c50d8ae3SPaolo Bonzini 1775c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1776c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1777c50d8ae3SPaolo Bonzini { 1778c50d8ae3SPaolo Bonzini u64 *sptep; 1779c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1780c50d8ae3SPaolo Bonzini 1781c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1782c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1783c50d8ae3SPaolo Bonzini } 1784c50d8ae3SPaolo Bonzini } 1785c50d8ae3SPaolo Bonzini 1786c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1787c50d8ae3SPaolo Bonzini { 1788c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1789c50d8ae3SPaolo Bonzini 179057354682SSean Christopherson sp = sptep_to_sp(spte); 179179e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1792c50d8ae3SPaolo Bonzini return; 1793c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1794c50d8ae3SPaolo Bonzini return; 1795c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1796c50d8ae3SPaolo Bonzini } 1797c50d8ae3SPaolo Bonzini 1798c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1799c50d8ae3SPaolo Bonzini 1800c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1801c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1802c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1803c50d8ae3SPaolo Bonzini unsigned int idx; 1804c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1805c50d8ae3SPaolo Bonzini unsigned int nr; 1806c50d8ae3SPaolo Bonzini }; 1807c50d8ae3SPaolo Bonzini 1808c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1809c50d8ae3SPaolo Bonzini int idx) 1810c50d8ae3SPaolo Bonzini { 1811c50d8ae3SPaolo Bonzini int i; 1812c50d8ae3SPaolo Bonzini 1813c50d8ae3SPaolo Bonzini if (sp->unsync) 1814c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1815c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1816c50d8ae3SPaolo Bonzini return 0; 1817c50d8ae3SPaolo Bonzini 1818c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1819c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1820c50d8ae3SPaolo Bonzini pvec->nr++; 1821c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1822c50d8ae3SPaolo Bonzini } 1823c50d8ae3SPaolo Bonzini 1824c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1825c50d8ae3SPaolo Bonzini { 1826c50d8ae3SPaolo Bonzini --sp->unsync_children; 182720ba462dSSean Christopherson WARN_ON_ONCE((int)sp->unsync_children < 0); 1828c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1829c50d8ae3SPaolo Bonzini } 1830c50d8ae3SPaolo Bonzini 1831c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1832c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1833c50d8ae3SPaolo Bonzini { 1834c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1835c50d8ae3SPaolo Bonzini 1836c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1837c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1838c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1839c50d8ae3SPaolo Bonzini 1840c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1841c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1842c50d8ae3SPaolo Bonzini continue; 1843c50d8ae3SPaolo Bonzini } 1844c50d8ae3SPaolo Bonzini 18455e3edd7eSSean Christopherson child = spte_to_child_sp(ent); 1846c50d8ae3SPaolo Bonzini 1847c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1848c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1849c50d8ae3SPaolo Bonzini return -ENOSPC; 1850c50d8ae3SPaolo Bonzini 1851c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1852c50d8ae3SPaolo Bonzini if (!ret) { 1853c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1854c50d8ae3SPaolo Bonzini continue; 1855c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1856c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1857c50d8ae3SPaolo Bonzini } else 1858c50d8ae3SPaolo Bonzini return ret; 1859c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1860c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1861c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1862c50d8ae3SPaolo Bonzini return -ENOSPC; 1863c50d8ae3SPaolo Bonzini } else 1864c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1865c50d8ae3SPaolo Bonzini } 1866c50d8ae3SPaolo Bonzini 1867c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1868c50d8ae3SPaolo Bonzini } 1869c50d8ae3SPaolo Bonzini 1870c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1871c50d8ae3SPaolo Bonzini 1872c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1873c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1874c50d8ae3SPaolo Bonzini { 1875c50d8ae3SPaolo Bonzini pvec->nr = 0; 1876c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1877c50d8ae3SPaolo Bonzini return 0; 1878c50d8ae3SPaolo Bonzini 1879c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1880c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1881c50d8ae3SPaolo Bonzini } 1882c50d8ae3SPaolo Bonzini 1883c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1884c50d8ae3SPaolo Bonzini { 188520ba462dSSean Christopherson WARN_ON_ONCE(!sp->unsync); 1886c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1887c50d8ae3SPaolo Bonzini sp->unsync = 0; 1888c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1889c50d8ae3SPaolo Bonzini } 1890c50d8ae3SPaolo Bonzini 1891c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1892c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1893c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1894c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1895c50d8ae3SPaolo Bonzini 1896767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1897767d8d8dSLai Jiangshan { 1898767d8d8dSLai Jiangshan if (sp->role.direct) 1899767d8d8dSLai Jiangshan return false; 1900767d8d8dSLai Jiangshan 190184e5ffd0SLai Jiangshan if (sp->role.passthrough) 190284e5ffd0SLai Jiangshan return false; 190384e5ffd0SLai Jiangshan 1904767d8d8dSLai Jiangshan return true; 1905767d8d8dSLai Jiangshan } 1906767d8d8dSLai Jiangshan 1907ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1908ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1909c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1910c50d8ae3SPaolo Bonzini } else 1911c50d8ae3SPaolo Bonzini 1912767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1913ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1914ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1915767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1916c50d8ae3SPaolo Bonzini 191790e44470SLai Jiangshan static bool kvm_sync_page_check(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 191890e44470SLai Jiangshan { 191990e44470SLai Jiangshan union kvm_mmu_page_role root_role = vcpu->arch.mmu->root_role; 192090e44470SLai Jiangshan 192190e44470SLai Jiangshan /* 192290e44470SLai Jiangshan * Ignore various flags when verifying that it's safe to sync a shadow 192390e44470SLai Jiangshan * page using the current MMU context. 192490e44470SLai Jiangshan * 192590e44470SLai Jiangshan * - level: not part of the overall MMU role and will never match as the MMU's 192690e44470SLai Jiangshan * level tracks the root level 192790e44470SLai Jiangshan * - access: updated based on the new guest PTE 192890e44470SLai Jiangshan * - quadrant: not part of the overall MMU role (similar to level) 192990e44470SLai Jiangshan */ 193090e44470SLai Jiangshan const union kvm_mmu_page_role sync_role_ign = { 193190e44470SLai Jiangshan .level = 0xf, 193290e44470SLai Jiangshan .access = 0x7, 193390e44470SLai Jiangshan .quadrant = 0x3, 193490e44470SLai Jiangshan .passthrough = 0x1, 193590e44470SLai Jiangshan }; 193690e44470SLai Jiangshan 193790e44470SLai Jiangshan /* 193890e44470SLai Jiangshan * Direct pages can never be unsync, and KVM should never attempt to 193990e44470SLai Jiangshan * sync a shadow page for a different MMU context, e.g. if the role 194090e44470SLai Jiangshan * differs then the memslot lookup (SMM vs. non-SMM) will be bogus, the 194190e44470SLai Jiangshan * reserved bits checks will be wrong, etc... 194290e44470SLai Jiangshan */ 1943c3c6c9fcSLai Jiangshan if (WARN_ON_ONCE(sp->role.direct || !vcpu->arch.mmu->sync_spte || 194490e44470SLai Jiangshan (sp->role.word ^ root_role.word) & ~sync_role_ign.word)) 194590e44470SLai Jiangshan return false; 194690e44470SLai Jiangshan 194790e44470SLai Jiangshan return true; 194890e44470SLai Jiangshan } 194990e44470SLai Jiangshan 195019ace7d6SLai Jiangshan static int kvm_sync_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int i) 195119ace7d6SLai Jiangshan { 195219ace7d6SLai Jiangshan if (!sp->spt[i]) 195319ace7d6SLai Jiangshan return 0; 195419ace7d6SLai Jiangshan 195519ace7d6SLai Jiangshan return vcpu->arch.mmu->sync_spte(vcpu, sp, i); 195619ace7d6SLai Jiangshan } 195719ace7d6SLai Jiangshan 195890e44470SLai Jiangshan static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 195990e44470SLai Jiangshan { 1960c3c6c9fcSLai Jiangshan int flush = 0; 1961c3c6c9fcSLai Jiangshan int i; 1962c3c6c9fcSLai Jiangshan 196390e44470SLai Jiangshan if (!kvm_sync_page_check(vcpu, sp)) 196490e44470SLai Jiangshan return -1; 196590e44470SLai Jiangshan 1966c3c6c9fcSLai Jiangshan for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 196719ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, i); 1968c3c6c9fcSLai Jiangshan 1969c3c6c9fcSLai Jiangshan if (ret < -1) 1970c3c6c9fcSLai Jiangshan return -1; 1971c3c6c9fcSLai Jiangshan flush |= ret; 1972c3c6c9fcSLai Jiangshan } 1973c3c6c9fcSLai Jiangshan 1974c3c6c9fcSLai Jiangshan /* 1975c3c6c9fcSLai Jiangshan * Note, any flush is purely for KVM's correctness, e.g. when dropping 1976c3c6c9fcSLai Jiangshan * an existing SPTE or clearing W/A/D bits to ensure an mmu_notifier 1977c3c6c9fcSLai Jiangshan * unmap or dirty logging event doesn't fail to flush. The guest is 1978c3c6c9fcSLai Jiangshan * responsible for flushing the TLB to ensure any changes in protection 1979c3c6c9fcSLai Jiangshan * bits are recognized, i.e. until the guest flushes or page faults on 1980c3c6c9fcSLai Jiangshan * a relevant address, KVM is architecturally allowed to let vCPUs use 1981c3c6c9fcSLai Jiangshan * cached translations with the old protection bits. 1982c3c6c9fcSLai Jiangshan */ 1983c3c6c9fcSLai Jiangshan return flush; 198490e44470SLai Jiangshan } 198590e44470SLai Jiangshan 19868d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1987c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1988c50d8ae3SPaolo Bonzini { 198990e44470SLai Jiangshan int ret = __kvm_sync_page(vcpu, sp); 1990c3e5e415SLai Jiangshan 19918d5678a7SHou Wenlong if (ret < 0) 1992c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 19938d5678a7SHou Wenlong return ret; 1994c50d8ae3SPaolo Bonzini } 1995c50d8ae3SPaolo Bonzini 1996c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1997c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1998c50d8ae3SPaolo Bonzini bool remote_flush) 1999c50d8ae3SPaolo Bonzini { 2000c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 2001c50d8ae3SPaolo Bonzini return false; 2002c50d8ae3SPaolo Bonzini 2003c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 2004c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 2005c50d8ae3SPaolo Bonzini else 2006c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2007c50d8ae3SPaolo Bonzini return true; 2008c50d8ae3SPaolo Bonzini } 2009c50d8ae3SPaolo Bonzini 2010c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 2011c50d8ae3SPaolo Bonzini { 2012a955cad8SSean Christopherson if (sp->role.invalid) 2013a955cad8SSean Christopherson return true; 2014a955cad8SSean Christopherson 2015fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 2016de0322f5SSean Christopherson return !is_tdp_mmu_page(sp) && 2017c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 2018c50d8ae3SPaolo Bonzini } 2019c50d8ae3SPaolo Bonzini 2020c50d8ae3SPaolo Bonzini struct mmu_page_path { 2021c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 2022c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 2023c50d8ae3SPaolo Bonzini }; 2024c50d8ae3SPaolo Bonzini 2025c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 2026c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 2027c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 2028c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 2029c50d8ae3SPaolo Bonzini 2030c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 2031c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 2032c50d8ae3SPaolo Bonzini int i) 2033c50d8ae3SPaolo Bonzini { 2034c50d8ae3SPaolo Bonzini int n; 2035c50d8ae3SPaolo Bonzini 2036c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 2037c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 2038c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 2039c50d8ae3SPaolo Bonzini int level = sp->role.level; 2040c50d8ae3SPaolo Bonzini 2041c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 20423bae0459SSean Christopherson if (level == PG_LEVEL_4K) 2043c50d8ae3SPaolo Bonzini break; 2044c50d8ae3SPaolo Bonzini 2045c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2046c50d8ae3SPaolo Bonzini } 2047c50d8ae3SPaolo Bonzini 2048c50d8ae3SPaolo Bonzini return n; 2049c50d8ae3SPaolo Bonzini } 2050c50d8ae3SPaolo Bonzini 2051c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 2052c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 2053c50d8ae3SPaolo Bonzini { 2054c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2055c50d8ae3SPaolo Bonzini int level; 2056c50d8ae3SPaolo Bonzini 2057c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 2058c50d8ae3SPaolo Bonzini return 0; 2059c50d8ae3SPaolo Bonzini 206020ba462dSSean Christopherson WARN_ON_ONCE(pvec->page[0].idx != INVALID_INDEX); 2061c50d8ae3SPaolo Bonzini 2062c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 2063c50d8ae3SPaolo Bonzini level = sp->role.level; 206420ba462dSSean Christopherson WARN_ON_ONCE(level == PG_LEVEL_4K); 2065c50d8ae3SPaolo Bonzini 2066c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2067c50d8ae3SPaolo Bonzini 2068c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 2069c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 2070c50d8ae3SPaolo Bonzini */ 2071c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 2072c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 2073c50d8ae3SPaolo Bonzini } 2074c50d8ae3SPaolo Bonzini 2075c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 2076c50d8ae3SPaolo Bonzini { 2077c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2078c50d8ae3SPaolo Bonzini unsigned int level = 0; 2079c50d8ae3SPaolo Bonzini 2080c50d8ae3SPaolo Bonzini do { 2081c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 2082c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 2083c50d8ae3SPaolo Bonzini if (!sp) 2084c50d8ae3SPaolo Bonzini return; 2085c50d8ae3SPaolo Bonzini 208620ba462dSSean Christopherson WARN_ON_ONCE(idx == INVALID_INDEX); 2087c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 2088c50d8ae3SPaolo Bonzini level++; 2089c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 2090c50d8ae3SPaolo Bonzini } 2091c50d8ae3SPaolo Bonzini 209265855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 209365855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 2094c50d8ae3SPaolo Bonzini { 2095c50d8ae3SPaolo Bonzini int i; 2096c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2097c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2098c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2099c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2100c50d8ae3SPaolo Bonzini bool flush = false; 2101c50d8ae3SPaolo Bonzini 2102c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2103c50d8ae3SPaolo Bonzini bool protected = false; 2104c50d8ae3SPaolo Bonzini 2105c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 2106cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 2107c50d8ae3SPaolo Bonzini 2108c50d8ae3SPaolo Bonzini if (protected) { 21095591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 2110c50d8ae3SPaolo Bonzini flush = false; 2111c50d8ae3SPaolo Bonzini } 2112c50d8ae3SPaolo Bonzini 2113c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2114479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 21158d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 2116c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2117c50d8ae3SPaolo Bonzini } 2118531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2119c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 212065855ed8SLai Jiangshan if (!can_yield) { 212165855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 212265855ed8SLai Jiangshan return -EINTR; 212365855ed8SLai Jiangshan } 212465855ed8SLai Jiangshan 2125531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2126c50d8ae3SPaolo Bonzini flush = false; 2127c50d8ae3SPaolo Bonzini } 2128c50d8ae3SPaolo Bonzini } 2129c50d8ae3SPaolo Bonzini 2130c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 213165855ed8SLai Jiangshan return 0; 2132c50d8ae3SPaolo Bonzini } 2133c50d8ae3SPaolo Bonzini 2134c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2135c50d8ae3SPaolo Bonzini { 2136c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2137c50d8ae3SPaolo Bonzini } 2138c50d8ae3SPaolo Bonzini 2139c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2140c50d8ae3SPaolo Bonzini { 214157354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2142c50d8ae3SPaolo Bonzini } 2143c50d8ae3SPaolo Bonzini 2144cbd858b1SDavid Matlack /* 2145cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2146cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2147cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2148cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2149cbd858b1SDavid Matlack */ 21503cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 21513cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 215294c81364SDavid Matlack gfn_t gfn, 215394c81364SDavid Matlack struct hlist_head *sp_list, 21542e65e842SDavid Matlack union kvm_mmu_page_role role) 2155c50d8ae3SPaolo Bonzini { 2156c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 21578d5678a7SHou Wenlong int ret; 2158c50d8ae3SPaolo Bonzini int collisions = 0; 2159c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2160c50d8ae3SPaolo Bonzini 21613cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2162c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2163c50d8ae3SPaolo Bonzini collisions++; 2164c50d8ae3SPaolo Bonzini continue; 2165c50d8ae3SPaolo Bonzini } 2166c50d8ae3SPaolo Bonzini 2167ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2168ddc16abbSSean Christopherson /* 2169ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2170ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2171ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2172ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2173ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2174ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2175ddc16abbSSean Christopherson * upper-level page will be write-protected. 2176ddc16abbSSean Christopherson */ 21772e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 21783cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2179ddc16abbSSean Christopherson &invalid_list); 2180c50d8ae3SPaolo Bonzini continue; 2181ddc16abbSSean Christopherson } 2182c50d8ae3SPaolo Bonzini 2183bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2184bb924ca6SDavid Matlack if (sp->role.direct) 218594c81364SDavid Matlack goto out; 2186fb58a9c3SSean Christopherson 2187c50d8ae3SPaolo Bonzini if (sp->unsync) { 2188cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2189cbd858b1SDavid Matlack break; 2190cbd858b1SDavid Matlack 219107dc4f35SSean Christopherson /* 2192479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 219307dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 219407dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 219507dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 219607dc4f35SSean Christopherson * overhead of write protection is not incurred until the 219707dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 219807dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 219907dc4f35SSean Christopherson * 220007dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 220107dc4f35SSean Christopherson * in order to rebuild it. 2202c50d8ae3SPaolo Bonzini */ 22038d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 22048d5678a7SHou Wenlong if (ret < 0) 2205c50d8ae3SPaolo Bonzini break; 2206c50d8ae3SPaolo Bonzini 220720ba462dSSean Christopherson WARN_ON_ONCE(!list_empty(&invalid_list)); 22088d5678a7SHou Wenlong if (ret > 0) 22093cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2210c50d8ae3SPaolo Bonzini } 2211c50d8ae3SPaolo Bonzini 2212c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2213fb58a9c3SSean Christopherson 2214c50d8ae3SPaolo Bonzini goto out; 2215c50d8ae3SPaolo Bonzini } 2216c50d8ae3SPaolo Bonzini 221794c81364SDavid Matlack sp = NULL; 22183cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2219c50d8ae3SPaolo Bonzini 222094c81364SDavid Matlack out: 22213cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 222294c81364SDavid Matlack 22233cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 22243cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 222594c81364SDavid Matlack return sp; 222694c81364SDavid Matlack } 222794c81364SDavid Matlack 22282f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 22292f8b1b53SDavid Matlack struct shadow_page_caches { 22302f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 22312f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 22326a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 22332f8b1b53SDavid Matlack }; 22342f8b1b53SDavid Matlack 2235336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 22362f8b1b53SDavid Matlack struct shadow_page_caches *caches, 223794c81364SDavid Matlack gfn_t gfn, 223894c81364SDavid Matlack struct hlist_head *sp_list, 223994c81364SDavid Matlack union kvm_mmu_page_role role) 224094c81364SDavid Matlack { 2241c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2242c306aec8SDavid Matlack 22432f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 22442f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2245c306aec8SDavid Matlack if (!role.direct) 22466a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2247c306aec8SDavid Matlack 2248c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2249c306aec8SDavid Matlack 225055c510e2SSean Christopherson INIT_LIST_HEAD(&sp->possible_nx_huge_page_link); 2251428e9216SSean Christopherson 2252c306aec8SDavid Matlack /* 2253c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2254c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2255c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2256c306aec8SDavid Matlack */ 2257336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2258336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 225943a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2260c50d8ae3SPaolo Bonzini 2261c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2262c50d8ae3SPaolo Bonzini sp->role = role; 2263ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2264be911771SDavid Matlack if (sp_has_gptes(sp)) 2265336081fbSDavid Matlack account_shadowed(kvm, sp); 2266ddc16abbSSean Christopherson 226794c81364SDavid Matlack return sp; 226894c81364SDavid Matlack } 226994c81364SDavid Matlack 2270cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 22713cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 22723cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 22732f8b1b53SDavid Matlack struct shadow_page_caches *caches, 227487654643SDavid Matlack gfn_t gfn, 227594c81364SDavid Matlack union kvm_mmu_page_role role) 227694c81364SDavid Matlack { 227794c81364SDavid Matlack struct hlist_head *sp_list; 227894c81364SDavid Matlack struct kvm_mmu_page *sp; 227994c81364SDavid Matlack bool created = false; 228094c81364SDavid Matlack 22813cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 228294c81364SDavid Matlack 22833cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 228494c81364SDavid Matlack if (!sp) { 228594c81364SDavid Matlack created = true; 22863cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 228794c81364SDavid Matlack } 228894c81364SDavid Matlack 228994c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2290c50d8ae3SPaolo Bonzini return sp; 2291c50d8ae3SPaolo Bonzini } 2292c50d8ae3SPaolo Bonzini 22932f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 22942f8b1b53SDavid Matlack gfn_t gfn, 22952f8b1b53SDavid Matlack union kvm_mmu_page_role role) 22962f8b1b53SDavid Matlack { 22972f8b1b53SDavid Matlack struct shadow_page_caches caches = { 22982f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 22992f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 23006a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 23012f8b1b53SDavid Matlack }; 23022f8b1b53SDavid Matlack 23033cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 23042f8b1b53SDavid Matlack } 23052f8b1b53SDavid Matlack 230639944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 230739944ab9SSean Christopherson unsigned int access) 23082e65e842SDavid Matlack { 23092e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 23102e65e842SDavid Matlack union kvm_mmu_page_role role; 23112e65e842SDavid Matlack 23122e65e842SDavid Matlack role = parent_sp->role; 23132e65e842SDavid Matlack role.level--; 23142e65e842SDavid Matlack role.access = access; 23152e65e842SDavid Matlack role.direct = direct; 23162e65e842SDavid Matlack role.passthrough = 0; 23172e65e842SDavid Matlack 23182e65e842SDavid Matlack /* 23192e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 23202e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 23212e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 23222e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 23232e65e842SDavid Matlack * requires extra bookkeeping in the role. 23242e65e842SDavid Matlack * 23252e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 23262e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 23272e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 23282e65e842SDavid Matlack * the address space each maps. 23292e65e842SDavid Matlack * 23302e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 23312e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 23322e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 23332e65e842SDavid Matlack * 233439944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 233539944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 233639944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 233739944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 233839944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 233939944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 234039944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 234139944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 234239944ab9SSean Christopherson * _least_ significant bit of the PDE index. 23432e65e842SDavid Matlack */ 23442e65e842SDavid Matlack if (role.has_4_byte_gpte) { 23452e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 234679e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 23472e65e842SDavid Matlack } 23482e65e842SDavid Matlack 23492e65e842SDavid Matlack return role; 23502e65e842SDavid Matlack } 23512e65e842SDavid Matlack 23522e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 23532e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 23542e65e842SDavid Matlack bool direct, unsigned int access) 23552e65e842SDavid Matlack { 23562e65e842SDavid Matlack union kvm_mmu_page_role role; 23572e65e842SDavid Matlack 23580cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 23590cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 23600cd8dc73SPaolo Bonzini 23612e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 236287654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 23632e65e842SDavid Matlack } 23642e65e842SDavid Matlack 2365c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2366c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2367c50d8ae3SPaolo Bonzini u64 addr) 2368c50d8ae3SPaolo Bonzini { 2369c50d8ae3SPaolo Bonzini iterator->addr = addr; 2370c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2371a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2372c50d8ae3SPaolo Bonzini 237312ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 23744d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2375347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 237612ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2377c50d8ae3SPaolo Bonzini 2378c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2379c50d8ae3SPaolo Bonzini /* 2380c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2381c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2382c50d8ae3SPaolo Bonzini */ 2383b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2384c50d8ae3SPaolo Bonzini 2385c50d8ae3SPaolo Bonzini iterator->shadow_addr 2386c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 23872ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2388c50d8ae3SPaolo Bonzini --iterator->level; 2389c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2390c50d8ae3SPaolo Bonzini iterator->level = 0; 2391c50d8ae3SPaolo Bonzini } 2392c50d8ae3SPaolo Bonzini } 2393c50d8ae3SPaolo Bonzini 2394c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2395c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2396c50d8ae3SPaolo Bonzini { 2397b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2398c50d8ae3SPaolo Bonzini addr); 2399c50d8ae3SPaolo Bonzini } 2400c50d8ae3SPaolo Bonzini 2401c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2402c50d8ae3SPaolo Bonzini { 24033bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2404c50d8ae3SPaolo Bonzini return false; 2405c50d8ae3SPaolo Bonzini 24062ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2407c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2408c50d8ae3SPaolo Bonzini return true; 2409c50d8ae3SPaolo Bonzini } 2410c50d8ae3SPaolo Bonzini 2411c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2412c50d8ae3SPaolo Bonzini u64 spte) 2413c50d8ae3SPaolo Bonzini { 24143e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2415c50d8ae3SPaolo Bonzini iterator->level = 0; 2416c50d8ae3SPaolo Bonzini return; 2417c50d8ae3SPaolo Bonzini } 2418c50d8ae3SPaolo Bonzini 24192ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2420c50d8ae3SPaolo Bonzini --iterator->level; 2421c50d8ae3SPaolo Bonzini } 2422c50d8ae3SPaolo Bonzini 2423c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2424c50d8ae3SPaolo Bonzini { 2425c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2426c50d8ae3SPaolo Bonzini } 2427c50d8ae3SPaolo Bonzini 24280cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 24290cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 243003787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2431c50d8ae3SPaolo Bonzini { 2432c50d8ae3SPaolo Bonzini u64 spte; 2433c50d8ae3SPaolo Bonzini 2434c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2435c50d8ae3SPaolo Bonzini 24360cd8dc73SPaolo Bonzini /* 24370cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 243803787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 243903787394SPaolo Bonzini * installing sp. 24400cd8dc73SPaolo Bonzini */ 24410cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 244203787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 24430cd8dc73SPaolo Bonzini 2444cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2445c50d8ae3SPaolo Bonzini 2446c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2447c50d8ae3SPaolo Bonzini 24482ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2449c50d8ae3SPaolo Bonzini 2450c4a48868SLai Jiangshan /* 2451c4a48868SLai Jiangshan * The non-direct sub-pagetable must be updated before linking. For 2452c4a48868SLai Jiangshan * L1 sp, the pagetable is updated via kvm_sync_page() in 2453c4a48868SLai Jiangshan * kvm_mmu_find_shadow_page() without write-protecting the gfn, 2454c4a48868SLai Jiangshan * so sp->unsync can be true or false. For higher level non-direct 2455c4a48868SLai Jiangshan * sp, the pagetable is updated/synced via mmu_sync_children() in 2456c4a48868SLai Jiangshan * FNAME(fetch)(), so sp->unsync_children can only be false. 2457c4a48868SLai Jiangshan * WARN_ON_ONCE() if anything happens unexpectedly. 2458c4a48868SLai Jiangshan */ 2459c4a48868SLai Jiangshan if (WARN_ON_ONCE(sp->unsync_children) || sp->unsync) 2460c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2461c50d8ae3SPaolo Bonzini } 2462c50d8ae3SPaolo Bonzini 24632ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 24642ff9039aSDavid Matlack struct kvm_mmu_page *sp) 24652ff9039aSDavid Matlack { 246603787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 24672ff9039aSDavid Matlack } 24682ff9039aSDavid Matlack 2469c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2470c50d8ae3SPaolo Bonzini unsigned direct_access) 2471c50d8ae3SPaolo Bonzini { 2472c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2473c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2474c50d8ae3SPaolo Bonzini 2475c50d8ae3SPaolo Bonzini /* 2476c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2477c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2478c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2479c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2480c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2481c50d8ae3SPaolo Bonzini */ 24825e3edd7eSSean Christopherson child = spte_to_child_sp(*sptep); 2483c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2484c50d8ae3SPaolo Bonzini return; 2485c50d8ae3SPaolo Bonzini 2486069f30c6SMingwei Zhang drop_parent_pte(vcpu->kvm, child, sptep); 24873cdf9374SHou Wenlong kvm_flush_remote_tlbs_sptep(vcpu->kvm, sptep); 2488c50d8ae3SPaolo Bonzini } 2489c50d8ae3SPaolo Bonzini } 2490c50d8ae3SPaolo Bonzini 24912de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 24922de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 24932de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2494c50d8ae3SPaolo Bonzini { 2495c50d8ae3SPaolo Bonzini u64 pte; 2496c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2497c50d8ae3SPaolo Bonzini 2498c50d8ae3SPaolo Bonzini pte = *spte; 2499c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2500c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2501c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2502c50d8ae3SPaolo Bonzini } else { 25035e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2504069f30c6SMingwei Zhang drop_parent_pte(kvm, child, spte); 25052de4085cSBen Gardon 25062de4085cSBen Gardon /* 25072de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 25082de4085cSBen Gardon * unlikely to be used again in the near future. This 25092de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 25102de4085cSBen Gardon */ 25112de4085cSBen Gardon if (tdp_enabled && invalid_list && 25122de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 25132de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 25142de4085cSBen Gardon invalid_list); 2515c50d8ae3SPaolo Bonzini } 2516ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2517c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2518ace569e0SSean Christopherson } 25192de4085cSBen Gardon return 0; 2520c50d8ae3SPaolo Bonzini } 2521c50d8ae3SPaolo Bonzini 25222de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 25232de4085cSBen Gardon struct kvm_mmu_page *sp, 25242de4085cSBen Gardon struct list_head *invalid_list) 2525c50d8ae3SPaolo Bonzini { 25262de4085cSBen Gardon int zapped = 0; 2527c50d8ae3SPaolo Bonzini unsigned i; 2528c50d8ae3SPaolo Bonzini 25292ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 25302de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 25312de4085cSBen Gardon 25322de4085cSBen Gardon return zapped; 2533c50d8ae3SPaolo Bonzini } 2534c50d8ae3SPaolo Bonzini 2535069f30c6SMingwei Zhang static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) 2536c50d8ae3SPaolo Bonzini { 2537c50d8ae3SPaolo Bonzini u64 *sptep; 2538c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2539c50d8ae3SPaolo Bonzini 2540c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2541069f30c6SMingwei Zhang drop_parent_pte(kvm, sp, sptep); 2542c50d8ae3SPaolo Bonzini } 2543c50d8ae3SPaolo Bonzini 2544c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2545c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2546c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2547c50d8ae3SPaolo Bonzini { 2548c50d8ae3SPaolo Bonzini int i, zapped = 0; 2549c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2550c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2551c50d8ae3SPaolo Bonzini 25523bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2553c50d8ae3SPaolo Bonzini return 0; 2554c50d8ae3SPaolo Bonzini 2555c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2556c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2557c50d8ae3SPaolo Bonzini 2558c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2559c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2560c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2561c50d8ae3SPaolo Bonzini zapped++; 2562c50d8ae3SPaolo Bonzini } 2563c50d8ae3SPaolo Bonzini } 2564c50d8ae3SPaolo Bonzini 2565c50d8ae3SPaolo Bonzini return zapped; 2566c50d8ae3SPaolo Bonzini } 2567c50d8ae3SPaolo Bonzini 2568c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2569c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2570c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2571c50d8ae3SPaolo Bonzini int *nr_zapped) 2572c50d8ae3SPaolo Bonzini { 2573527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2574c50d8ae3SPaolo Bonzini 257547b0c2e4SKazuki Takiguchi lockdep_assert_held_write(&kvm->mmu_lock); 2576c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2577c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2578c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 25792de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 2580069f30c6SMingwei Zhang kvm_mmu_unlink_parents(kvm, sp); 2581c50d8ae3SPaolo Bonzini 2582c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2583c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2584c50d8ae3SPaolo Bonzini 2585767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2586c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2587c50d8ae3SPaolo Bonzini 2588c50d8ae3SPaolo Bonzini if (sp->unsync) 2589c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2590c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2591c50d8ae3SPaolo Bonzini /* Count self */ 2592c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2593f95eec9bSSean Christopherson 2594f95eec9bSSean Christopherson /* 2595f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2596f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2597f95eec9bSSean Christopherson * !sp->root_count. 2598f95eec9bSSean Christopherson */ 2599f95eec9bSSean Christopherson if (sp->role.invalid) 2600f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2601f95eec9bSSean Christopherson else 2602c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 260343a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2604c50d8ae3SPaolo Bonzini } else { 2605f95eec9bSSean Christopherson /* 2606f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2607f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2608f95eec9bSSean Christopherson */ 2609f95eec9bSSean Christopherson list_del(&sp->link); 2610c50d8ae3SPaolo Bonzini 2611c50d8ae3SPaolo Bonzini /* 2612c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2613c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2614c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2615c50d8ae3SPaolo Bonzini */ 2616527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2617c50d8ae3SPaolo Bonzini } 2618c50d8ae3SPaolo Bonzini 261955c510e2SSean Christopherson if (sp->nx_huge_page_disallowed) 262055c510e2SSean Christopherson unaccount_nx_huge_page(kvm, sp); 2621c50d8ae3SPaolo Bonzini 2622c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2623527d5cd7SSean Christopherson 2624527d5cd7SSean Christopherson /* 2625527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2626527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2627527d5cd7SSean Christopherson */ 2628527d5cd7SSean Christopherson if (zapped_root) 2629527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2630c50d8ae3SPaolo Bonzini return list_unstable; 2631c50d8ae3SPaolo Bonzini } 2632c50d8ae3SPaolo Bonzini 2633c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2634c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2635c50d8ae3SPaolo Bonzini { 2636c50d8ae3SPaolo Bonzini int nr_zapped; 2637c50d8ae3SPaolo Bonzini 2638c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2639c50d8ae3SPaolo Bonzini return nr_zapped; 2640c50d8ae3SPaolo Bonzini } 2641c50d8ae3SPaolo Bonzini 2642c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2643c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2644c50d8ae3SPaolo Bonzini { 2645c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2646c50d8ae3SPaolo Bonzini 2647c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2648c50d8ae3SPaolo Bonzini return; 2649c50d8ae3SPaolo Bonzini 2650c50d8ae3SPaolo Bonzini /* 2651c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2652c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2653c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2654c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2655c50d8ae3SPaolo Bonzini * 2656c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2657c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2658c50d8ae3SPaolo Bonzini */ 2659c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2660c50d8ae3SPaolo Bonzini 2661c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 266220ba462dSSean Christopherson WARN_ON_ONCE(!sp->role.invalid || sp->root_count); 266387654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2664c50d8ae3SPaolo Bonzini } 2665c50d8ae3SPaolo Bonzini } 2666c50d8ae3SPaolo Bonzini 26676b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 26686b82ef2cSSean Christopherson unsigned long nr_to_zap) 2669c50d8ae3SPaolo Bonzini { 26706b82ef2cSSean Christopherson unsigned long total_zapped = 0; 26716b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2672ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 26736b82ef2cSSean Christopherson bool unstable; 26746b82ef2cSSean Christopherson int nr_zapped; 2675c50d8ae3SPaolo Bonzini 2676c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2677ba7888ddSSean Christopherson return 0; 2678c50d8ae3SPaolo Bonzini 26796b82ef2cSSean Christopherson restart: 26808fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 26816b82ef2cSSean Christopherson /* 26826b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 26836b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 26846b82ef2cSSean Christopherson */ 26856b82ef2cSSean Christopherson if (sp->root_count) 26866b82ef2cSSean Christopherson continue; 26876b82ef2cSSean Christopherson 26886b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 26896b82ef2cSSean Christopherson &nr_zapped); 26906b82ef2cSSean Christopherson total_zapped += nr_zapped; 26916b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2692ba7888ddSSean Christopherson break; 2693ba7888ddSSean Christopherson 26946b82ef2cSSean Christopherson if (unstable) 26956b82ef2cSSean Christopherson goto restart; 2696ba7888ddSSean Christopherson } 26976b82ef2cSSean Christopherson 26986b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 26996b82ef2cSSean Christopherson 27006b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 27016b82ef2cSSean Christopherson return total_zapped; 27026b82ef2cSSean Christopherson } 27036b82ef2cSSean Christopherson 2704afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2705afe8d7e6SSean Christopherson { 2706afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2707afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2708afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2709afe8d7e6SSean Christopherson 2710afe8d7e6SSean Christopherson return 0; 2711c50d8ae3SPaolo Bonzini } 2712c50d8ae3SPaolo Bonzini 2713ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2714ba7888ddSSean Christopherson { 27156b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2716ba7888ddSSean Christopherson 27176b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2718ba7888ddSSean Christopherson return 0; 2719ba7888ddSSean Christopherson 27206b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2721ba7888ddSSean Christopherson 27226e6ec584SSean Christopherson /* 27236e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 27246e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 27256e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 27266e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2727c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 27286e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 27296e6ec584SSean Christopherson * page fault paths. 27306e6ec584SSean Christopherson */ 2731ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2732ba7888ddSSean Christopherson return -ENOSPC; 2733ba7888ddSSean Christopherson return 0; 2734ba7888ddSSean Christopherson } 2735ba7888ddSSean Christopherson 2736c50d8ae3SPaolo Bonzini /* 2737c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2738c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2739c50d8ae3SPaolo Bonzini */ 2740c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2741c50d8ae3SPaolo Bonzini { 2742531810caSBen Gardon write_lock(&kvm->mmu_lock); 2743c50d8ae3SPaolo Bonzini 2744c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 27456b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 27466b82ef2cSSean Christopherson goal_nr_mmu_pages); 2747c50d8ae3SPaolo Bonzini 2748c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2749c50d8ae3SPaolo Bonzini } 2750c50d8ae3SPaolo Bonzini 2751c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2752c50d8ae3SPaolo Bonzini 2753531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2754c50d8ae3SPaolo Bonzini } 2755c50d8ae3SPaolo Bonzini 2756c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2757c50d8ae3SPaolo Bonzini { 2758c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2759c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2760c50d8ae3SPaolo Bonzini int r; 2761c50d8ae3SPaolo Bonzini 2762c50d8ae3SPaolo Bonzini r = 0; 2763531810caSBen Gardon write_lock(&kvm->mmu_lock); 2764767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2765c50d8ae3SPaolo Bonzini r = 1; 2766c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2767c50d8ae3SPaolo Bonzini } 2768c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2769531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2770c50d8ae3SPaolo Bonzini 2771c50d8ae3SPaolo Bonzini return r; 2772c50d8ae3SPaolo Bonzini } 277396ad91aeSSean Christopherson 277496ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 277596ad91aeSSean Christopherson { 277696ad91aeSSean Christopherson gpa_t gpa; 277796ad91aeSSean Christopherson int r; 277896ad91aeSSean Christopherson 2779347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 278096ad91aeSSean Christopherson return 0; 278196ad91aeSSean Christopherson 278296ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 278396ad91aeSSean Christopherson 278496ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 278596ad91aeSSean Christopherson 278696ad91aeSSean Christopherson return r; 278796ad91aeSSean Christopherson } 2788c50d8ae3SPaolo Bonzini 27894d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2790c50d8ae3SPaolo Bonzini { 2791c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 27924d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2793c50d8ae3SPaolo Bonzini sp->unsync = 1; 2794c50d8ae3SPaolo Bonzini 2795c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2796c50d8ae3SPaolo Bonzini } 2797c50d8ae3SPaolo Bonzini 27980337f585SSean Christopherson /* 27990337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 28000337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 28010337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 28020337f585SSean Christopherson * be write-protected. 28030337f585SSean Christopherson */ 28048283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 28052839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2806c50d8ae3SPaolo Bonzini { 2807c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2808ce25681dSSean Christopherson bool locked = false; 2809c50d8ae3SPaolo Bonzini 28100337f585SSean Christopherson /* 28110337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 28120337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 28130337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 28140337f585SSean Christopherson */ 28157b574863SSean Christopherson if (kvm_gfn_is_write_tracked(kvm, slot, gfn)) 28160337f585SSean Christopherson return -EPERM; 2817c50d8ae3SPaolo Bonzini 28180337f585SSean Christopherson /* 28190337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 28200337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 28210337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 28220337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 28230337f585SSean Christopherson */ 2824767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2825c50d8ae3SPaolo Bonzini if (!can_unsync) 28260337f585SSean Christopherson return -EPERM; 2827c50d8ae3SPaolo Bonzini 2828c50d8ae3SPaolo Bonzini if (sp->unsync) 2829c50d8ae3SPaolo Bonzini continue; 2830c50d8ae3SPaolo Bonzini 28312839180cSPaolo Bonzini if (prefetch) 2832f1c4a88cSLai Jiangshan return -EEXIST; 2833f1c4a88cSLai Jiangshan 2834ce25681dSSean Christopherson /* 2835ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2836ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2837ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2838ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2839ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2840ce25681dSSean Christopherson */ 2841ce25681dSSean Christopherson if (!locked) { 2842ce25681dSSean Christopherson locked = true; 28434d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2844ce25681dSSean Christopherson 2845ce25681dSSean Christopherson /* 2846ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2847ce25681dSSean Christopherson * may have since marked the page unsync. A false 2848e59f75deSPaolo Bonzini * negative on the unprotected check above is not 2849ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2850e59f75deSPaolo Bonzini * for write, i.e. unsync cannot transition from 1->0 2851ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2852ce25681dSSean Christopherson */ 2853ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2854ce25681dSSean Christopherson continue; 2855ce25681dSSean Christopherson } 2856ce25681dSSean Christopherson 285720ba462dSSean Christopherson WARN_ON_ONCE(sp->role.level != PG_LEVEL_4K); 28584d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2859c50d8ae3SPaolo Bonzini } 2860ce25681dSSean Christopherson if (locked) 28614d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2862c50d8ae3SPaolo Bonzini 2863c50d8ae3SPaolo Bonzini /* 2864c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2865c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2866c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2867c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2868c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2869c50d8ae3SPaolo Bonzini * following could happen: 2870c50d8ae3SPaolo Bonzini * 2871c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2872c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2873c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2874c50d8ae3SPaolo Bonzini * to be writable 2875c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2876c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2877c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2878c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2879c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2880c50d8ae3SPaolo Bonzini * fault. 2881c50d8ae3SPaolo Bonzini * 2882c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2883c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2884c50d8ae3SPaolo Bonzini * 28850337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 28860337f585SSean Christopherson * false and skips the page. 2887c50d8ae3SPaolo Bonzini * 2888c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2889c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2890c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2891c50d8ae3SPaolo Bonzini * gets used. 2892c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2893c50d8ae3SPaolo Bonzini * as unsync 2894c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2895c50d8ae3SPaolo Bonzini * 2896c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2897264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2898264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2899c50d8ae3SPaolo Bonzini */ 2900c50d8ae3SPaolo Bonzini smp_wmb(); 2901c50d8ae3SPaolo Bonzini 29020337f585SSean Christopherson return 0; 2903c50d8ae3SPaolo Bonzini } 2904c50d8ae3SPaolo Bonzini 29058a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 29068a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2907a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2908799a4190SBen Gardon { 2909d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2910eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2911c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2912c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2913c50d8ae3SPaolo Bonzini bool flush = false; 2914ad67e480SPaolo Bonzini bool wrprot; 2915d786c778SPaolo Bonzini u64 spte; 2916c50d8ae3SPaolo Bonzini 2917a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2918a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 29192839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2920a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2921c50d8ae3SPaolo Bonzini 2922a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 29231075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2924a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2925a54aa15cSSean Christopherson return RET_PF_EMULATE; 2926a54aa15cSSean Christopherson } 2927a54aa15cSSean Christopherson 2928c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2929c50d8ae3SPaolo Bonzini /* 2930c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2931c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2932c50d8ae3SPaolo Bonzini */ 29333bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2934c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2935c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2936c50d8ae3SPaolo Bonzini 29375e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2938069f30c6SMingwei Zhang drop_parent_pte(vcpu->kvm, child, sptep); 2939c50d8ae3SPaolo Bonzini flush = true; 2940c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2941c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2942c50d8ae3SPaolo Bonzini flush = true; 2943c50d8ae3SPaolo Bonzini } else 2944c50d8ae3SPaolo Bonzini was_rmapped = 1; 2945c50d8ae3SPaolo Bonzini } 2946c50d8ae3SPaolo Bonzini 29472839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 29487158bee4SPaolo Bonzini true, host_writable, &spte); 2949d786c778SPaolo Bonzini 2950d786c778SPaolo Bonzini if (*sptep == spte) { 2951d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2952d786c778SPaolo Bonzini } else { 2953d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 29545959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2955c50d8ae3SPaolo Bonzini } 2956c50d8ae3SPaolo Bonzini 2957ad67e480SPaolo Bonzini if (wrprot) { 2958c50d8ae3SPaolo Bonzini if (write_fault) 2959c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2960c50d8ae3SPaolo Bonzini } 2961c50d8ae3SPaolo Bonzini 2962d786c778SPaolo Bonzini if (flush) 29634ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(vcpu->kvm, gfn, level); 2964c50d8ae3SPaolo Bonzini 2965c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2966d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 29676a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 29686a97575dSDavid Matlack } else { 29696a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 297079e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2971c50d8ae3SPaolo Bonzini } 2972c50d8ae3SPaolo Bonzini 2973c50d8ae3SPaolo Bonzini return ret; 2974c50d8ae3SPaolo Bonzini } 2975c50d8ae3SPaolo Bonzini 2976c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2977c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2978c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2979c50d8ae3SPaolo Bonzini { 2980c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2981c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 29820a2b64c5SBen Gardon unsigned int access = sp->role.access; 2983c50d8ae3SPaolo Bonzini int i, ret; 2984c50d8ae3SPaolo Bonzini gfn_t gfn; 2985c50d8ae3SPaolo Bonzini 298679e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 2987c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2988c50d8ae3SPaolo Bonzini if (!slot) 2989c50d8ae3SPaolo Bonzini return -1; 2990c50d8ae3SPaolo Bonzini 2991c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2992c50d8ae3SPaolo Bonzini if (ret <= 0) 2993c50d8ae3SPaolo Bonzini return -1; 2994c50d8ae3SPaolo Bonzini 2995c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 29968a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2997a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2998c50d8ae3SPaolo Bonzini put_page(pages[i]); 2999c50d8ae3SPaolo Bonzini } 3000c50d8ae3SPaolo Bonzini 3001c50d8ae3SPaolo Bonzini return 0; 3002c50d8ae3SPaolo Bonzini } 3003c50d8ae3SPaolo Bonzini 3004c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 3005c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 3006c50d8ae3SPaolo Bonzini { 3007c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 3008c50d8ae3SPaolo Bonzini int i; 3009c50d8ae3SPaolo Bonzini 301020ba462dSSean Christopherson WARN_ON_ONCE(!sp->role.direct); 3011c50d8ae3SPaolo Bonzini 301279e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 3013c50d8ae3SPaolo Bonzini spte = sp->spt + i; 3014c50d8ae3SPaolo Bonzini 3015c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 3016c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 3017c50d8ae3SPaolo Bonzini if (!start) 3018c50d8ae3SPaolo Bonzini continue; 3019c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 3020c6cecc4bSSean Christopherson return; 3021c50d8ae3SPaolo Bonzini start = NULL; 3022c50d8ae3SPaolo Bonzini } else if (!start) 3023c50d8ae3SPaolo Bonzini start = spte; 3024c50d8ae3SPaolo Bonzini } 3025c6cecc4bSSean Christopherson if (start) 3026c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 3027c50d8ae3SPaolo Bonzini } 3028c50d8ae3SPaolo Bonzini 3029c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 3030c50d8ae3SPaolo Bonzini { 3031c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3032c50d8ae3SPaolo Bonzini 303357354682SSean Christopherson sp = sptep_to_sp(sptep); 3034c50d8ae3SPaolo Bonzini 3035c50d8ae3SPaolo Bonzini /* 3036c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 3037c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 3038c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 3039c50d8ae3SPaolo Bonzini */ 3040c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 3041c50d8ae3SPaolo Bonzini return; 3042c50d8ae3SPaolo Bonzini 30433bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 3044c50d8ae3SPaolo Bonzini return; 3045c50d8ae3SPaolo Bonzini 30464a42d848SDavid Stevens /* 30474a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 30484a42d848SDavid Stevens * accidentally prefetching those addresses. 30494a42d848SDavid Stevens */ 305020ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 30514a42d848SDavid Stevens return; 30524a42d848SDavid Stevens 3053c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 3054c50d8ae3SPaolo Bonzini } 3055c50d8ae3SPaolo Bonzini 305665e3b446SSean Christopherson /* 305765e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 305865e3b446SSean Christopherson * 305965e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 306065e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 306165e3b446SSean Christopherson * 306265e3b446SSean Christopherson * There are several ways to safely use this helper: 306365e3b446SSean Christopherson * 30648569992dSChao Peng * - Check mmu_invalidate_retry_gfn() after grabbing the mapping level, before 306565e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 306665e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 306765e3b446SSean Christopherson * 306865e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 306965e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 307065e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 307165e3b446SSean Christopherson * 307265e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 307365e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 307465e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 307565e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 307665e3b446SSean Christopherson * 307765e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 307865e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 307965e3b446SSean Christopherson * race with the primary MMU occurs. 308065e3b446SSean Christopherson */ 3081a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 30828ca6f063SBen Gardon const struct kvm_memory_slot *slot) 3083db543216SSean Christopherson { 3084284dc493SSean Christopherson int level = PG_LEVEL_4K; 3085db543216SSean Christopherson unsigned long hva; 308644187235SMingwei Zhang unsigned long flags; 308744187235SMingwei Zhang pgd_t pgd; 308844187235SMingwei Zhang p4d_t p4d; 308944187235SMingwei Zhang pud_t pud; 309044187235SMingwei Zhang pmd_t pmd; 3091db543216SSean Christopherson 30925d49f08cSSean Christopherson /* 3093293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 3094293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 3095293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 3096293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 3097293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 3098293e306eSSean Christopherson * read-only memslot. 3099293e306eSSean Christopherson */ 3100db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 3101db543216SSean Christopherson 310244187235SMingwei Zhang /* 310365e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 310465e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 310565e3b446SSean Christopherson * the original page table. 310644187235SMingwei Zhang */ 310744187235SMingwei Zhang local_irq_save(flags); 3108db543216SSean Christopherson 310965e3b446SSean Christopherson /* 311065e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 311165e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 311265e3b446SSean Christopherson * walk into the weeks, e.g. p*d_large() returns false (sees the old 311365e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 311465e3b446SSean Christopherson * of the old page table (sees the new value). 311565e3b446SSean Christopherson */ 311644187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 311744187235SMingwei Zhang if (pgd_none(pgd)) 311844187235SMingwei Zhang goto out; 311944187235SMingwei Zhang 312044187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 312144187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 312244187235SMingwei Zhang goto out; 312344187235SMingwei Zhang 312444187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 312544187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 312644187235SMingwei Zhang goto out; 312744187235SMingwei Zhang 312844187235SMingwei Zhang if (pud_large(pud)) { 312944187235SMingwei Zhang level = PG_LEVEL_1G; 313044187235SMingwei Zhang goto out; 313144187235SMingwei Zhang } 313244187235SMingwei Zhang 313344187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 313444187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 313544187235SMingwei Zhang goto out; 313644187235SMingwei Zhang 313744187235SMingwei Zhang if (pmd_large(pmd)) 313844187235SMingwei Zhang level = PG_LEVEL_2M; 313944187235SMingwei Zhang 314044187235SMingwei Zhang out: 314144187235SMingwei Zhang local_irq_restore(flags); 3142db543216SSean Christopherson return level; 3143db543216SSean Christopherson } 3144db543216SSean Christopherson 31458dd2eee9SChao Peng static int __kvm_mmu_max_mapping_level(struct kvm *kvm, 31468dd2eee9SChao Peng const struct kvm_memory_slot *slot, 31478dd2eee9SChao Peng gfn_t gfn, int max_level, bool is_private) 31481b6d9d9eSSean Christopherson { 31491b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3150ec607a56SPaolo Bonzini int host_level; 31511b6d9d9eSSean Christopherson 31521b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 31531b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 31541b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 31551b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 31561b6d9d9eSSean Christopherson break; 31571b6d9d9eSSean Christopherson } 31581b6d9d9eSSean Christopherson 31598dd2eee9SChao Peng if (is_private) 31608dd2eee9SChao Peng return max_level; 31618dd2eee9SChao Peng 31621b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 31631b6d9d9eSSean Christopherson return PG_LEVEL_4K; 31641b6d9d9eSSean Christopherson 3165a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3166ec607a56SPaolo Bonzini return min(host_level, max_level); 31671b6d9d9eSSean Christopherson } 31681b6d9d9eSSean Christopherson 31698dd2eee9SChao Peng int kvm_mmu_max_mapping_level(struct kvm *kvm, 31708dd2eee9SChao Peng const struct kvm_memory_slot *slot, gfn_t gfn, 31718dd2eee9SChao Peng int max_level) 31728dd2eee9SChao Peng { 31738dd2eee9SChao Peng bool is_private = kvm_slot_can_be_private(slot) && 31748dd2eee9SChao Peng kvm_mem_is_private(kvm, gfn); 31758dd2eee9SChao Peng 31768dd2eee9SChao Peng return __kvm_mmu_max_mapping_level(kvm, slot, gfn, max_level, is_private); 31778dd2eee9SChao Peng } 31788dd2eee9SChao Peng 317973a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 31800885904dSSean Christopherson { 3181e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 318217eff019SSean Christopherson kvm_pfn_t mask; 31830885904dSSean Christopherson 318473a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 31853cf06612SSean Christopherson 318673a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 318773a3c659SPaolo Bonzini return; 318817eff019SSean Christopherson 31895d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 319073a3c659SPaolo Bonzini return; 319117eff019SSean Christopherson 3192e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 319373a3c659SPaolo Bonzini return; 3194293e306eSSean Christopherson 31953cf06612SSean Christopherson /* 31963cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 31973cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 31983cf06612SSean Christopherson */ 31998dd2eee9SChao Peng fault->req_level = __kvm_mmu_max_mapping_level(vcpu->kvm, slot, 32008dd2eee9SChao Peng fault->gfn, fault->max_level, 32018dd2eee9SChao Peng fault->is_private); 320273a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 320373a3c659SPaolo Bonzini return; 32044cd071d1SSean Christopherson 32050885904dSSean Christopherson /* 320620ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 32074cd071d1SSean Christopherson * the pmd can't be split from under us. 32080885904dSSean Christopherson */ 320973a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 321073a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 321173a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 321273a3c659SPaolo Bonzini fault->pfn &= ~mask; 32130885904dSSean Christopherson } 32140885904dSSean Christopherson 3215536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3216c50d8ae3SPaolo Bonzini { 3217536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3218536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3219c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 322076901e56SMingwei Zhang !is_large_pte(spte) && 322176901e56SMingwei Zhang spte_to_child_sp(spte)->nx_huge_page_disallowed) { 3222c50d8ae3SPaolo Bonzini /* 32236c882ef4SDavid Matlack * A small SPTE exists for this pfn, but FNAME(fetch), 32246c882ef4SDavid Matlack * direct_map(), or kvm_tdp_mmu_map() would like to create a 32256c882ef4SDavid Matlack * large PTE instead: just force them to go down another level, 32266c882ef4SDavid Matlack * patching back for them into pfn the next 9 bits of the 32276c882ef4SDavid Matlack * address. 3228c50d8ae3SPaolo Bonzini */ 3229536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3230536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3231536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3232536f0e6aSPaolo Bonzini fault->goal_level--; 3233c50d8ae3SPaolo Bonzini } 3234c50d8ae3SPaolo Bonzini } 3235c50d8ae3SPaolo Bonzini 32366c882ef4SDavid Matlack static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3237c50d8ae3SPaolo Bonzini { 3238c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3239c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 324073a3c659SPaolo Bonzini int ret; 324143b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3242c50d8ae3SPaolo Bonzini 324373a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 32444cd071d1SSean Christopherson 3245f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 324643b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3247c50d8ae3SPaolo Bonzini /* 3248c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3249c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3250c50d8ae3SPaolo Bonzini */ 325173a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3252536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3253c50d8ae3SPaolo Bonzini 3254c667a3baSHou Wenlong base_gfn = gfn_round_for_level(fault->gfn, it.level); 325573a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3256c50d8ae3SPaolo Bonzini break; 3257c50d8ae3SPaolo Bonzini 32582e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 32590cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 32600cd8dc73SPaolo Bonzini continue; 3261c50d8ae3SPaolo Bonzini 3262c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 3263b5b0977fSSean Christopherson if (fault->huge_page_disallowed) 326455c510e2SSean Christopherson account_nx_huge_page(vcpu->kvm, sp, 3265428e9216SSean Christopherson fault->req_level >= it.level); 3266c50d8ae3SPaolo Bonzini } 3267c50d8ae3SPaolo Bonzini 3268b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3269b1a429fbSSean Christopherson return -EFAULT; 3270b1a429fbSSean Christopherson 32718a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3272a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 327312703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 327412703759SSean Christopherson return ret; 327512703759SSean Christopherson 3276c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3277c50d8ae3SPaolo Bonzini return ret; 3278c50d8ae3SPaolo Bonzini } 3279c50d8ae3SPaolo Bonzini 3280cd08d178SDavid Matlack static void kvm_send_hwpoison_signal(struct kvm_memory_slot *slot, gfn_t gfn) 3281c50d8ae3SPaolo Bonzini { 3282cd08d178SDavid Matlack unsigned long hva = gfn_to_hva_memslot(slot, gfn); 3283cd08d178SDavid Matlack 3284cd08d178SDavid Matlack send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); 3285c50d8ae3SPaolo Bonzini } 3286c50d8ae3SPaolo Bonzini 3287cd08d178SDavid Matlack static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3288c50d8ae3SPaolo Bonzini { 3289cd08d178SDavid Matlack if (is_sigpending_pfn(fault->pfn)) { 329076657687SPeter Xu kvm_handle_signal_exit(vcpu); 329176657687SPeter Xu return -EINTR; 329276657687SPeter Xu } 329376657687SPeter Xu 3294c50d8ae3SPaolo Bonzini /* 3295c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3296c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3297c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3298c50d8ae3SPaolo Bonzini */ 3299cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_RO_FAULT) 3300c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3301c50d8ae3SPaolo Bonzini 3302cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_HWPOISON) { 3303cd08d178SDavid Matlack kvm_send_hwpoison_signal(fault->slot, fault->gfn); 3304c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3305c50d8ae3SPaolo Bonzini } 3306c50d8ae3SPaolo Bonzini 3307c50d8ae3SPaolo Bonzini return -EFAULT; 3308c50d8ae3SPaolo Bonzini } 3309c50d8ae3SPaolo Bonzini 3310354c908cSDavid Matlack static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu, 3311354c908cSDavid Matlack struct kvm_page_fault *fault, 33125276c616SSean Christopherson unsigned int access) 3313c50d8ae3SPaolo Bonzini { 33143a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 33153a13f4feSPaolo Bonzini 33163a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3317c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 3318354c908cSDavid Matlack 331930ab5901SSean Christopherson /* 332030ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 332130ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 3322354c908cSDavid Matlack * MMIO SPTE will just be an expensive nop. 332330ab5901SSean Christopherson */ 3324354c908cSDavid Matlack if (unlikely(!enable_mmio_caching)) 33255276c616SSean Christopherson return RET_PF_EMULATE; 3326354c908cSDavid Matlack 3327354c908cSDavid Matlack /* 3328354c908cSDavid Matlack * Do not create an MMIO SPTE for a gfn greater than host.MAXPHYADDR, 3329354c908cSDavid Matlack * any guest that generates such gfns is running nested and is being 3330354c908cSDavid Matlack * tricked by L0 userspace (you can observe gfn > L1.MAXPHYADDR if and 3331354c908cSDavid Matlack * only if L1's MAXPHYADDR is inaccurate with respect to the 3332354c908cSDavid Matlack * hardware's). 3333354c908cSDavid Matlack */ 3334354c908cSDavid Matlack if (unlikely(fault->gfn > kvm_mmu_max_gfn())) 3335354c908cSDavid Matlack return RET_PF_EMULATE; 3336c50d8ae3SPaolo Bonzini 33375276c616SSean Christopherson return RET_PF_CONTINUE; 3338c50d8ae3SPaolo Bonzini } 3339c50d8ae3SPaolo Bonzini 33403c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3341c50d8ae3SPaolo Bonzini { 3342c50d8ae3SPaolo Bonzini /* 33435c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 33445c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 33455c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 33465c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3347c50d8ae3SPaolo Bonzini */ 33483c8ad5a6SPaolo Bonzini if (fault->rsvd) 3349c50d8ae3SPaolo Bonzini return false; 3350c50d8ae3SPaolo Bonzini 3351c50d8ae3SPaolo Bonzini /* 3352c50d8ae3SPaolo Bonzini * #PF can be fast if: 3353c50d8ae3SPaolo Bonzini * 335454275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 335554275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 335654275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 335754275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 335854275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 335954275f74SSean Christopherson * mechanism only supports direct MMUs. 336054275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 336154275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 336254275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 336354275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 336454275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3365c50d8ae3SPaolo Bonzini */ 33665c64aba5SSean Christopherson if (!fault->present) 33675c64aba5SSean Christopherson return !kvm_ad_enabled(); 33685c64aba5SSean Christopherson 33695c64aba5SSean Christopherson /* 33705c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 33715c64aba5SSean Christopherson * the "exec" flag. 33725c64aba5SSean Christopherson */ 33735c64aba5SSean Christopherson return fault->write; 3374c50d8ae3SPaolo Bonzini } 3375c50d8ae3SPaolo Bonzini 3376c50d8ae3SPaolo Bonzini /* 3377c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3378c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3379c50d8ae3SPaolo Bonzini */ 3380f3d90f90SSean Christopherson static bool fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, 3381f3d90f90SSean Christopherson struct kvm_page_fault *fault, 3382c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3383c50d8ae3SPaolo Bonzini { 3384c50d8ae3SPaolo Bonzini /* 3385c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3386c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3387c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3388c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3389c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3390c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3391c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3392c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3393c50d8ae3SPaolo Bonzini * 3394c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3395c50d8ae3SPaolo Bonzini */ 33962db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3397c50d8ae3SPaolo Bonzini return false; 3398c50d8ae3SPaolo Bonzini 3399e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3400e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3401c50d8ae3SPaolo Bonzini 3402c50d8ae3SPaolo Bonzini return true; 3403c50d8ae3SPaolo Bonzini } 3404c50d8ae3SPaolo Bonzini 34053c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3406c50d8ae3SPaolo Bonzini { 34073c8ad5a6SPaolo Bonzini if (fault->exec) 3408c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3409c50d8ae3SPaolo Bonzini 34103c8ad5a6SPaolo Bonzini if (fault->write) 3411c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3412c50d8ae3SPaolo Bonzini 3413c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3414c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3415c50d8ae3SPaolo Bonzini } 3416c50d8ae3SPaolo Bonzini 3417c50d8ae3SPaolo Bonzini /* 34186e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 34196e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 34206e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 34216e8eb206SDavid Matlack * 34226e8eb206SDavid Matlack * Contract: 34236e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 34246e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 34256e8eb206SDavid Matlack */ 34266e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 34276e8eb206SDavid Matlack { 34286e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 34296e8eb206SDavid Matlack u64 old_spte; 34306e8eb206SDavid Matlack u64 *sptep = NULL; 34316e8eb206SDavid Matlack 34326e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 34336e8eb206SDavid Matlack sptep = iterator.sptep; 34346e8eb206SDavid Matlack *spte = old_spte; 34356e8eb206SDavid Matlack } 34366e8eb206SDavid Matlack 34376e8eb206SDavid Matlack return sptep; 34386e8eb206SDavid Matlack } 34396e8eb206SDavid Matlack 34406e8eb206SDavid Matlack /* 3441c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3442c50d8ae3SPaolo Bonzini */ 34433c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3444c50d8ae3SPaolo Bonzini { 3445c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3446c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 34471de9992fSLi zeming u64 spte; 34481de9992fSLi zeming u64 *sptep; 3449c50d8ae3SPaolo Bonzini uint retry_count = 0; 3450c50d8ae3SPaolo Bonzini 34513c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3452c4371c2aSSean Christopherson return ret; 3453c50d8ae3SPaolo Bonzini 3454c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3455c50d8ae3SPaolo Bonzini 3456c50d8ae3SPaolo Bonzini do { 3457c50d8ae3SPaolo Bonzini u64 new_spte; 3458c50d8ae3SPaolo Bonzini 3459dfe0ecc6SSean Christopherson if (tdp_mmu_enabled) 34603c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 34616e8eb206SDavid Matlack else 34623c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3463c50d8ae3SPaolo Bonzini 34641de9992fSLi zeming /* 34651de9992fSLi zeming * It's entirely possible for the mapping to have been zapped 34661de9992fSLi zeming * by a different task, but the root page should always be 34671de9992fSLi zeming * available as the vCPU holds a reference to its root(s). 34681de9992fSLi zeming */ 34691de9992fSLi zeming if (WARN_ON_ONCE(!sptep)) 34701de9992fSLi zeming spte = REMOVED_SPTE; 34711de9992fSLi zeming 3472ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3473ec89e643SSean Christopherson break; 3474ec89e643SSean Christopherson 34756e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3476c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3477c50d8ae3SPaolo Bonzini break; 3478c50d8ae3SPaolo Bonzini 3479c50d8ae3SPaolo Bonzini /* 3480c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3481c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3482c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3483c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3484c50d8ae3SPaolo Bonzini * current CPU took the fault. 3485c50d8ae3SPaolo Bonzini * 3486c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3487c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3488c50d8ae3SPaolo Bonzini */ 34893c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3490c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3491c50d8ae3SPaolo Bonzini break; 3492c50d8ae3SPaolo Bonzini } 3493c50d8ae3SPaolo Bonzini 3494c50d8ae3SPaolo Bonzini new_spte = spte; 3495c50d8ae3SPaolo Bonzini 349654275f74SSean Christopherson /* 349754275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 349854275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 349954275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 350054275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 350154275f74SSean Christopherson */ 350254275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3503c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3504c50d8ae3SPaolo Bonzini 3505c50d8ae3SPaolo Bonzini /* 350654275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 350754275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 350854275f74SSean Christopherson * that were write-protected for dirty-logging or access 350954275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 351054275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 351154275f74SSean Christopherson * The is_access_allowed() check above handles the common case 351254275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 351354275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 351454275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3515c50d8ae3SPaolo Bonzini */ 3516706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3517c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3518c50d8ae3SPaolo Bonzini 3519c50d8ae3SPaolo Bonzini /* 352010c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 352110c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 352210c30de0SJunaid Shahid * first page into the dirty-bitmap in 3523c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3524c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3525c50d8ae3SPaolo Bonzini * 3526c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3527c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3528c50d8ae3SPaolo Bonzini */ 352910c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 353010c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3531c50d8ae3SPaolo Bonzini break; 3532c50d8ae3SPaolo Bonzini } 3533c50d8ae3SPaolo Bonzini 3534c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3535c50d8ae3SPaolo Bonzini if (new_spte == spte || 35363c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3537c50d8ae3SPaolo Bonzini break; 3538c50d8ae3SPaolo Bonzini 3539c50d8ae3SPaolo Bonzini /* 3540c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3541c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 35423ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3543c50d8ae3SPaolo Bonzini */ 3544e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3545c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3546c50d8ae3SPaolo Bonzini break; 3547c4371c2aSSean Christopherson } 3548c50d8ae3SPaolo Bonzini 3549c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 35508d20bd63SSean Christopherson pr_warn_once("Fast #PF retrying more than 4 times.\n"); 3551c50d8ae3SPaolo Bonzini break; 3552c50d8ae3SPaolo Bonzini } 3553c50d8ae3SPaolo Bonzini 3554c50d8ae3SPaolo Bonzini } while (true); 3555c50d8ae3SPaolo Bonzini 3556f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3557c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3558c50d8ae3SPaolo Bonzini 35591075d41eSSean Christopherson if (ret != RET_PF_INVALID) 35601075d41eSSean Christopherson vcpu->stat.pf_fast++; 35611075d41eSSean Christopherson 3562c4371c2aSSean Christopherson return ret; 3563c50d8ae3SPaolo Bonzini } 3564c50d8ae3SPaolo Bonzini 3565c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3566c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3567c50d8ae3SPaolo Bonzini { 3568c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3569c50d8ae3SPaolo Bonzini 3570c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3571c50d8ae3SPaolo Bonzini return; 3572c50d8ae3SPaolo Bonzini 3573c5f2d564SSean Christopherson sp = root_to_sp(*root_hpa); 357420ba462dSSean Christopherson if (WARN_ON_ONCE(!sp)) 35759191b8f0SPaolo Bonzini return; 357602c00b3aSBen Gardon 3577897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 35785f3c8c91SPaolo Bonzini kvm_tdp_mmu_put_root(kvm, sp); 357976eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3580c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3581c50d8ae3SPaolo Bonzini 3582c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3583c50d8ae3SPaolo Bonzini } 3584c50d8ae3SPaolo Bonzini 3585c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 35860c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3587c50d8ae3SPaolo Bonzini ulong roots_to_free) 3588c50d8ae3SPaolo Bonzini { 3589c50d8ae3SPaolo Bonzini int i; 3590c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3591594bef79SPaolo Bonzini bool free_active_root; 3592c50d8ae3SPaolo Bonzini 3593f94db0c8SSean Christopherson WARN_ON_ONCE(roots_to_free & ~KVM_MMU_ROOTS_ALL); 3594f94db0c8SSean Christopherson 3595c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3596c50d8ae3SPaolo Bonzini 3597c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3598594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3599594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3600594bef79SPaolo Bonzini 3601594bef79SPaolo Bonzini if (!free_active_root) { 3602c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3603c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3604c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3605c50d8ae3SPaolo Bonzini break; 3606c50d8ae3SPaolo Bonzini 3607c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3608c50d8ae3SPaolo Bonzini return; 3609c50d8ae3SPaolo Bonzini } 3610c50d8ae3SPaolo Bonzini 3611531810caSBen Gardon write_lock(&kvm->mmu_lock); 3612c50d8ae3SPaolo Bonzini 3613c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3614c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 36154d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3616c50d8ae3SPaolo Bonzini &invalid_list); 3617c50d8ae3SPaolo Bonzini 3618c50d8ae3SPaolo Bonzini if (free_active_root) { 36190e3223d8SSean Christopherson if (kvm_mmu_is_dummy_root(mmu->root.hpa)) { 36200e3223d8SSean Christopherson /* Nothing to cleanup for dummy roots. */ 36210e3223d8SSean Christopherson } else if (root_to_sp(mmu->root.hpa)) { 3622b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 362304d45551SSean Christopherson } else if (mmu->pae_root) { 3624c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3625c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3626c834e5e4SSean Christopherson continue; 3627c834e5e4SSean Christopherson 3628c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3629c50d8ae3SPaolo Bonzini &invalid_list); 3630c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3631c50d8ae3SPaolo Bonzini } 3632c50d8ae3SPaolo Bonzini } 3633b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3634b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3635c50d8ae3SPaolo Bonzini } 3636c50d8ae3SPaolo Bonzini 36374d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3638531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3639c50d8ae3SPaolo Bonzini } 3640c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3641c50d8ae3SPaolo Bonzini 36420c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 364325b62c62SSean Christopherson { 364425b62c62SSean Christopherson unsigned long roots_to_free = 0; 3645c5f2d564SSean Christopherson struct kvm_mmu_page *sp; 364625b62c62SSean Christopherson hpa_t root_hpa; 364725b62c62SSean Christopherson int i; 364825b62c62SSean Christopherson 364925b62c62SSean Christopherson /* 365025b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 365125b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 365225b62c62SSean Christopherson */ 36537a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 365425b62c62SSean Christopherson 365525b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 365625b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 365725b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 365825b62c62SSean Christopherson continue; 365925b62c62SSean Christopherson 3660c5f2d564SSean Christopherson sp = root_to_sp(root_hpa); 3661c5f2d564SSean Christopherson if (!sp || sp->role.guest_mode) 366225b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 366325b62c62SSean Christopherson } 366425b62c62SSean Christopherson 36650c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 366625b62c62SSean Christopherson } 366725b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 366825b62c62SSean Christopherson 36692e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 367086938ab6SDavid Matlack u8 level) 3671c50d8ae3SPaolo Bonzini { 36722e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3673c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 36748123f265SSean Christopherson 36752e65e842SDavid Matlack role.level = level; 36762e65e842SDavid Matlack role.quadrant = quadrant; 36772e65e842SDavid Matlack 36787f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 36797f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 36807f497775SDavid Matlack 368187654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 36828123f265SSean Christopherson ++sp->root_count; 36838123f265SSean Christopherson 36848123f265SSean Christopherson return __pa(sp->spt); 36858123f265SSean Christopherson } 36868123f265SSean Christopherson 36878123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 36888123f265SSean Christopherson { 3689b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3690a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 36918123f265SSean Christopherson hpa_t root; 3692c50d8ae3SPaolo Bonzini unsigned i; 36934a38162eSPaolo Bonzini int r; 36944a38162eSPaolo Bonzini 36954a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36964a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36974a38162eSPaolo Bonzini if (r < 0) 36984a38162eSPaolo Bonzini goto out_unlock; 3699c50d8ae3SPaolo Bonzini 37001f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 370102c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3702b9e5603cSPaolo Bonzini mmu->root.hpa = root; 370302c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 370486938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3705b9e5603cSPaolo Bonzini mmu->root.hpa = root; 37068123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 37074a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 37084a38162eSPaolo Bonzini r = -EIO; 37094a38162eSPaolo Bonzini goto out_unlock; 37104a38162eSPaolo Bonzini } 371173ad1606SSean Christopherson 3712c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3713c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3714c50d8ae3SPaolo Bonzini 37157f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 37162e65e842SDavid Matlack PT32_ROOT_LEVEL); 371717e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3718d2263de1SYuan Yao shadow_me_value; 3719c50d8ae3SPaolo Bonzini } 3720b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 372173ad1606SSean Christopherson } else { 372273ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 37234a38162eSPaolo Bonzini r = -EIO; 37244a38162eSPaolo Bonzini goto out_unlock; 372573ad1606SSean Christopherson } 37263651c7fcSSean Christopherson 3727b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3728b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 37294a38162eSPaolo Bonzini out_unlock: 37304a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 37314a38162eSPaolo Bonzini return r; 3732c50d8ae3SPaolo Bonzini } 3733c50d8ae3SPaolo Bonzini 37341e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 37351e76a3ceSDavid Stevens { 37361e76a3ceSDavid Stevens struct kvm_memslots *slots; 37371e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3738a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 37391e76a3ceSDavid Stevens 37401e76a3ceSDavid Stevens /* 37411e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 37421e76a3ceSDavid Stevens * taking the lock. 37431e76a3ceSDavid Stevens */ 37441e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37451e76a3ceSDavid Stevens return 0; 37461e76a3ceSDavid Stevens 37471e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 37481e76a3ceSDavid Stevens 37491e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 37501e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37511e76a3ceSDavid Stevens goto out_unlock; 37521e76a3ceSDavid Stevens 37531e76a3ceSDavid Stevens /* 37541e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 37551e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 37561e76a3ceSDavid Stevens */ 37571e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 37581e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 37591e76a3ceSDavid Stevens goto out_success; 37601e76a3ceSDavid Stevens 3761eed52e43SSean Christopherson for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { 37621e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3763a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 37641e76a3ceSDavid Stevens /* 37651e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 37661e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 37671e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 37681e76a3ceSDavid Stevens * failure to avoid having to track which allocations 37691e76a3ceSDavid Stevens * were made now versus when the memslot was created. 37701e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 37711e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 37721e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 37731e76a3ceSDavid Stevens */ 37741e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 37751e76a3ceSDavid Stevens if (r) 37761e76a3ceSDavid Stevens goto out_unlock; 37771e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 37781e76a3ceSDavid Stevens if (r) 37791e76a3ceSDavid Stevens goto out_unlock; 37801e76a3ceSDavid Stevens } 37811e76a3ceSDavid Stevens } 37821e76a3ceSDavid Stevens 37831e76a3ceSDavid Stevens /* 37841e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 37851e76a3ceSDavid Stevens * all the related pointers are set. 37861e76a3ceSDavid Stevens */ 37871e76a3ceSDavid Stevens out_success: 37881e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 37891e76a3ceSDavid Stevens 37901e76a3ceSDavid Stevens out_unlock: 37911e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 37921e76a3ceSDavid Stevens return r; 37931e76a3ceSDavid Stevens } 37941e76a3ceSDavid Stevens 3795c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3796c50d8ae3SPaolo Bonzini { 3797b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 37986e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3799be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 38007f497775SDavid Matlack int quadrant, i, r; 38018123f265SSean Christopherson hpa_t root; 3802c50d8ae3SPaolo Bonzini 38032fdcc1b3SPaolo Bonzini root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu); 3804a130066fSBinbin Wu root_gfn = (root_pgd & __PT_BASE_ADDR_MASK) >> PAGE_SHIFT; 3805c50d8ae3SPaolo Bonzini 38060e3223d8SSean Christopherson if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 38070e3223d8SSean Christopherson mmu->root.hpa = kvm_mmu_get_dummy_root(); 38080e3223d8SSean Christopherson return 0; 38090e3223d8SSean Christopherson } 3810c50d8ae3SPaolo Bonzini 3811c50d8ae3SPaolo Bonzini /* 38124a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 38134a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 38144a38162eSPaolo Bonzini */ 38154d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38166e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 38176e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 38186e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 38196e0918aeSSean Christopherson continue; 38206e0918aeSSean Christopherson 38210e3223d8SSean Christopherson if (!kvm_vcpu_is_visible_gfn(vcpu, pdptrs[i] >> PAGE_SHIFT)) 38220e3223d8SSean Christopherson pdptrs[i] = 0; 38236e0918aeSSean Christopherson } 38246e0918aeSSean Christopherson } 38256e0918aeSSean Christopherson 38261e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3827d501f747SBen Gardon if (r) 3828d501f747SBen Gardon return r; 3829d501f747SBen Gardon 38304a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 38314a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 38324a38162eSPaolo Bonzini if (r < 0) 38334a38162eSPaolo Bonzini goto out_unlock; 38344a38162eSPaolo Bonzini 3835c50d8ae3SPaolo Bonzini /* 3836c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3837c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3838c50d8ae3SPaolo Bonzini */ 38394d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 38408123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 384186938ab6SDavid Matlack mmu->root_role.level); 3842b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3843be01e8e2SSean Christopherson goto set_root_pgd; 3844c50d8ae3SPaolo Bonzini } 3845c50d8ae3SPaolo Bonzini 38464a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 38474a38162eSPaolo Bonzini r = -EIO; 38484a38162eSPaolo Bonzini goto out_unlock; 38494a38162eSPaolo Bonzini } 385073ad1606SSean Christopherson 3851c50d8ae3SPaolo Bonzini /* 3852c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3853c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3854c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3855c50d8ae3SPaolo Bonzini */ 3856e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3857a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3858c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3859c50d8ae3SPaolo Bonzini 386003ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 38614a38162eSPaolo Bonzini r = -EIO; 38624a38162eSPaolo Bonzini goto out_unlock; 38634a38162eSPaolo Bonzini } 386403ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3865cb0f722aSWei Huang 3866a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3867cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3868cb0f722aSWei Huang r = -EIO; 3869cb0f722aSWei Huang goto out_unlock; 3870cb0f722aSWei Huang } 3871cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3872cb0f722aSWei Huang } 387304d45551SSean Christopherson } 387404d45551SSean Christopherson 3875c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3876c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 38776e6ec584SSean Christopherson 38784d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38796e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3880c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3881c50d8ae3SPaolo Bonzini continue; 3882c50d8ae3SPaolo Bonzini } 38836e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3884c50d8ae3SPaolo Bonzini } 3885c50d8ae3SPaolo Bonzini 38867f497775SDavid Matlack /* 38877f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 38887f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 38897f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 38907f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 38917f497775SDavid Matlack */ 38927f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 38937f497775SDavid Matlack 38947f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3895b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3896c50d8ae3SPaolo Bonzini } 3897c50d8ae3SPaolo Bonzini 3898a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3899b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3900a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3901b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3902ba0a194fSSean Christopherson else 3903b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3904c50d8ae3SPaolo Bonzini 3905be01e8e2SSean Christopherson set_root_pgd: 3906b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 39074a38162eSPaolo Bonzini out_unlock: 39084a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3909c50d8ae3SPaolo Bonzini 3910c6c937d6SLike Xu return r; 3911c50d8ae3SPaolo Bonzini } 3912c50d8ae3SPaolo Bonzini 3913748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3914c50d8ae3SPaolo Bonzini { 3915748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3916a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3917cb0f722aSWei Huang u64 *pml5_root = NULL; 3918cb0f722aSWei Huang u64 *pml4_root = NULL; 3919cb0f722aSWei Huang u64 *pae_root; 3920748e52b9SSean Christopherson 3921748e52b9SSean Christopherson /* 3922748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3923748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3924748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3925748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3926748e52b9SSean Christopherson */ 3927347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3928347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3929a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3930748e52b9SSean Christopherson return 0; 3931748e52b9SSean Christopherson 3932a717a780SSean Christopherson /* 3933a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3934a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3935a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3936a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3937a717a780SSean Christopherson * prior MMU would also have required pml5. 3938a717a780SSean Christopherson */ 3939a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3940748e52b9SSean Christopherson return 0; 3941748e52b9SSean Christopherson 3942748e52b9SSean Christopherson /* 3943748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3944748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3945748e52b9SSean Christopherson */ 3946cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3947a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3948748e52b9SSean Christopherson return -EIO; 3949748e52b9SSean Christopherson 39504a98623dSSean Christopherson /* 39514a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 39524a98623dSSean Christopherson * doesn't need to be decrypted. 39534a98623dSSean Christopherson */ 3954748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3955748e52b9SSean Christopherson if (!pae_root) 3956748e52b9SSean Christopherson return -ENOMEM; 3957748e52b9SSean Christopherson 3958cb0f722aSWei Huang #ifdef CONFIG_X86_64 395903ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3960cb0f722aSWei Huang if (!pml4_root) 3961cb0f722aSWei Huang goto err_pml4; 3962cb0f722aSWei Huang 3963a717a780SSean Christopherson if (need_pml5) { 3964cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3965cb0f722aSWei Huang if (!pml5_root) 3966cb0f722aSWei Huang goto err_pml5; 3967748e52b9SSean Christopherson } 3968cb0f722aSWei Huang #endif 3969748e52b9SSean Christopherson 3970748e52b9SSean Christopherson mmu->pae_root = pae_root; 397103ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3972cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3973748e52b9SSean Christopherson 3974748e52b9SSean Christopherson return 0; 3975cb0f722aSWei Huang 3976cb0f722aSWei Huang #ifdef CONFIG_X86_64 3977cb0f722aSWei Huang err_pml5: 3978cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3979cb0f722aSWei Huang err_pml4: 3980cb0f722aSWei Huang free_page((unsigned long)pae_root); 3981cb0f722aSWei Huang return -ENOMEM; 3982cb0f722aSWei Huang #endif 3983c50d8ae3SPaolo Bonzini } 3984c50d8ae3SPaolo Bonzini 3985264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3986264d3dc1SLai Jiangshan { 3987264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3988264d3dc1SLai Jiangshan 39890e3223d8SSean Christopherson if (!VALID_PAGE(root) || kvm_mmu_is_dummy_root(root)) 399061b05a9fSLai Jiangshan return false; 399161b05a9fSLai Jiangshan 3992264d3dc1SLai Jiangshan /* 3993264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3994264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3995264d3dc1SLai Jiangshan * 3996264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3997264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3998264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3999264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 4000264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 4001264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 4002264d3dc1SLai Jiangshan * requirement isn't satisfied. 4003264d3dc1SLai Jiangshan */ 4004264d3dc1SLai Jiangshan smp_rmb(); 4005c5f2d564SSean Christopherson sp = root_to_sp(root); 40065d6a3221SSean Christopherson 40075d6a3221SSean Christopherson /* 40085d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 40095d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 40105d6a3221SSean Christopherson */ 40115d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 40125d6a3221SSean Christopherson return false; 40135d6a3221SSean Christopherson 4014264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 4015264d3dc1SLai Jiangshan return true; 4016264d3dc1SLai Jiangshan 4017264d3dc1SLai Jiangshan return false; 4018264d3dc1SLai Jiangshan } 4019264d3dc1SLai Jiangshan 4020c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 4021c50d8ae3SPaolo Bonzini { 4022c50d8ae3SPaolo Bonzini int i; 4023c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 4024c50d8ae3SPaolo Bonzini 4025347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 4026c50d8ae3SPaolo Bonzini return; 4027c50d8ae3SPaolo Bonzini 4028b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 4029c50d8ae3SPaolo Bonzini return; 4030c50d8ae3SPaolo Bonzini 4031c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4032c50d8ae3SPaolo Bonzini 40334d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 4034b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 4035c50d8ae3SPaolo Bonzini 4036264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 4037c50d8ae3SPaolo Bonzini return; 4038c50d8ae3SPaolo Bonzini 4039c5f2d564SSean Christopherson sp = root_to_sp(root); 4040c5f2d564SSean Christopherson 4041531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 404265855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4043531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4044c50d8ae3SPaolo Bonzini return; 4045c50d8ae3SPaolo Bonzini } 4046c50d8ae3SPaolo Bonzini 4047531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4048c50d8ae3SPaolo Bonzini 4049c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 4050c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 4051c50d8ae3SPaolo Bonzini 4052c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 40535e3edd7eSSean Christopherson sp = spte_to_child_sp(root); 405465855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4055c50d8ae3SPaolo Bonzini } 4056c50d8ae3SPaolo Bonzini } 4057c50d8ae3SPaolo Bonzini 4058531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4059c50d8ae3SPaolo Bonzini } 4060c50d8ae3SPaolo Bonzini 406161b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 406261b05a9fSLai Jiangshan { 406361b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 406461b05a9fSLai Jiangshan int i; 406561b05a9fSLai Jiangshan 406661b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 406761b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 406861b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 406961b05a9fSLai Jiangshan 407061b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 40710c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 407261b05a9fSLai Jiangshan } 407361b05a9fSLai Jiangshan 40741f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 40755b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 4076c50d8ae3SPaolo Bonzini struct x86_exception *exception) 4077c50d8ae3SPaolo Bonzini { 4078c50d8ae3SPaolo Bonzini if (exception) 4079c50d8ae3SPaolo Bonzini exception->error_code = 0; 4080c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 4081c50d8ae3SPaolo Bonzini } 4082c50d8ae3SPaolo Bonzini 4083c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4084c50d8ae3SPaolo Bonzini { 4085c50d8ae3SPaolo Bonzini /* 4086c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 4087c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 4088c50d8ae3SPaolo Bonzini */ 4089c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 4090c50d8ae3SPaolo Bonzini return false; 4091c50d8ae3SPaolo Bonzini 4092c50d8ae3SPaolo Bonzini if (direct) 4093c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 4094c50d8ae3SPaolo Bonzini 4095c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 4096c50d8ae3SPaolo Bonzini } 4097c50d8ae3SPaolo Bonzini 409895fb5b02SBen Gardon /* 409995fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 410095fb5b02SBen Gardon * That SPTE may be non-present. 4101c5c8c7c5SDavid Matlack * 4102c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 410395fb5b02SBen Gardon */ 410439b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 4105c50d8ae3SPaolo Bonzini { 4106c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 41072aa07893SSean Christopherson int leaf = -1; 410895fb5b02SBen Gardon u64 spte; 4109c50d8ae3SPaolo Bonzini 411039b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 411139b4d43eSSean Christopherson *root_level = iterator.level; 4112c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 4113c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 411495fb5b02SBen Gardon leaf = iterator.level; 4115c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 4116c50d8ae3SPaolo Bonzini 4117dde81f94SSean Christopherson sptes[leaf] = spte; 411895fb5b02SBen Gardon } 411995fb5b02SBen Gardon 412095fb5b02SBen Gardon return leaf; 412195fb5b02SBen Gardon } 412295fb5b02SBen Gardon 41239aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 412495fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 412595fb5b02SBen Gardon { 4126dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 412795fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 412839b4d43eSSean Christopherson int root, leaf, level; 412995fb5b02SBen Gardon bool reserved = false; 413095fb5b02SBen Gardon 4131c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 4132c5c8c7c5SDavid Matlack 413378fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) 413439b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 413595fb5b02SBen Gardon else 413639b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 413795fb5b02SBen Gardon 4138c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 4139c5c8c7c5SDavid Matlack 41402aa07893SSean Christopherson if (unlikely(leaf < 0)) { 41412aa07893SSean Christopherson *sptep = 0ull; 41422aa07893SSean Christopherson return reserved; 41432aa07893SSean Christopherson } 41442aa07893SSean Christopherson 41459aa41879SSean Christopherson *sptep = sptes[leaf]; 41469aa41879SSean Christopherson 41479aa41879SSean Christopherson /* 41489aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 41499aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 41509aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 41519aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 41529aa41879SSean Christopherson */ 41539aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 41549aa41879SSean Christopherson leaf++; 415595fb5b02SBen Gardon 415695fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 415795fb5b02SBen Gardon 41589aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4159961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4160c50d8ae3SPaolo Bonzini 4161c50d8ae3SPaolo Bonzini if (reserved) { 4162bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4163c50d8ae3SPaolo Bonzini __func__, addr); 416495fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4165bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4166bb4cdf3aSSean Christopherson sptes[level], level, 4167961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4168c50d8ae3SPaolo Bonzini } 4169ddce6208SSean Christopherson 4170c50d8ae3SPaolo Bonzini return reserved; 4171c50d8ae3SPaolo Bonzini } 4172c50d8ae3SPaolo Bonzini 4173c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4174c50d8ae3SPaolo Bonzini { 4175c50d8ae3SPaolo Bonzini u64 spte; 4176c50d8ae3SPaolo Bonzini bool reserved; 4177c50d8ae3SPaolo Bonzini 4178c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4179c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4180c50d8ae3SPaolo Bonzini 418195fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 418220ba462dSSean Christopherson if (WARN_ON_ONCE(reserved)) 4183c50d8ae3SPaolo Bonzini return -EINVAL; 4184c50d8ae3SPaolo Bonzini 4185c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4186c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 41870a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4188c50d8ae3SPaolo Bonzini 4189c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4190c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4191c50d8ae3SPaolo Bonzini 4192c50d8ae3SPaolo Bonzini if (direct) 4193c50d8ae3SPaolo Bonzini addr = 0; 4194c50d8ae3SPaolo Bonzini 4195c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4196c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4197c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4198c50d8ae3SPaolo Bonzini } 4199c50d8ae3SPaolo Bonzini 4200c50d8ae3SPaolo Bonzini /* 4201c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4202c50d8ae3SPaolo Bonzini * the address. 4203c50d8ae3SPaolo Bonzini */ 4204c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4205c50d8ae3SPaolo Bonzini } 4206c50d8ae3SPaolo Bonzini 4207c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4208b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4209c50d8ae3SPaolo Bonzini { 4210b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4211c50d8ae3SPaolo Bonzini return false; 4212c50d8ae3SPaolo Bonzini 4213b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4214c50d8ae3SPaolo Bonzini return false; 4215c50d8ae3SPaolo Bonzini 4216c50d8ae3SPaolo Bonzini /* 4217c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4218c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4219c50d8ae3SPaolo Bonzini */ 42207b574863SSean Christopherson if (kvm_gfn_is_write_tracked(vcpu->kvm, fault->slot, fault->gfn)) 4221c50d8ae3SPaolo Bonzini return true; 4222c50d8ae3SPaolo Bonzini 4223c50d8ae3SPaolo Bonzini return false; 4224c50d8ae3SPaolo Bonzini } 4225c50d8ae3SPaolo Bonzini 4226c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4227c50d8ae3SPaolo Bonzini { 4228c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4229c50d8ae3SPaolo Bonzini u64 spte; 4230c50d8ae3SPaolo Bonzini 4231c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 42323e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4233c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4234c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4235c50d8ae3SPaolo Bonzini } 4236c50d8ae3SPaolo Bonzini 42376f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 42386f3c1fc5SLiang Zhang { 42396f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 42406f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 42416f3c1fc5SLiang Zhang 42426f3c1fc5SLiang Zhang if (id << 12 == 0) 42436f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 42446f3c1fc5SLiang Zhang 42456f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 42466f3c1fc5SLiang Zhang } 42476f3c1fc5SLiang Zhang 4248e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 42499f1a8526SSean Christopherson gfn_t gfn) 4250c50d8ae3SPaolo Bonzini { 4251c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4252c50d8ae3SPaolo Bonzini 42536f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4254c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4255347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 42562fdcc1b3SPaolo Bonzini arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu); 4257c50d8ae3SPaolo Bonzini 42589f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 42599f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4260c50d8ae3SPaolo Bonzini } 4261c50d8ae3SPaolo Bonzini 42628a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 42638a009d5bSSean Christopherson { 42648a009d5bSSean Christopherson int r; 42658a009d5bSSean Christopherson 42668a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 42678a009d5bSSean Christopherson work->wakeup_all) 42688a009d5bSSean Christopherson return; 42698a009d5bSSean Christopherson 42708a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 42718a009d5bSSean Christopherson if (unlikely(r)) 42728a009d5bSSean Christopherson return; 42738a009d5bSSean Christopherson 42748a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 42752fdcc1b3SPaolo Bonzini work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu)) 42768a009d5bSSean Christopherson return; 42778a009d5bSSean Christopherson 4278258d985fSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true, NULL); 42798a009d5bSSean Christopherson } 42808a009d5bSSean Christopherson 42818dd2eee9SChao Peng static inline u8 kvm_max_level_for_order(int order) 42828dd2eee9SChao Peng { 42838dd2eee9SChao Peng BUILD_BUG_ON(KVM_MAX_HUGEPAGE_LEVEL > PG_LEVEL_1G); 42848dd2eee9SChao Peng 42858dd2eee9SChao Peng KVM_MMU_WARN_ON(order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_1G) && 42868dd2eee9SChao Peng order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_2M) && 42878dd2eee9SChao Peng order != KVM_HPAGE_GFN_SHIFT(PG_LEVEL_4K)); 42888dd2eee9SChao Peng 42898dd2eee9SChao Peng if (order >= KVM_HPAGE_GFN_SHIFT(PG_LEVEL_1G)) 42908dd2eee9SChao Peng return PG_LEVEL_1G; 42918dd2eee9SChao Peng 42928dd2eee9SChao Peng if (order >= KVM_HPAGE_GFN_SHIFT(PG_LEVEL_2M)) 42938dd2eee9SChao Peng return PG_LEVEL_2M; 42948dd2eee9SChao Peng 42958dd2eee9SChao Peng return PG_LEVEL_4K; 42968dd2eee9SChao Peng } 42978dd2eee9SChao Peng 42988dd2eee9SChao Peng static void kvm_mmu_prepare_memory_fault_exit(struct kvm_vcpu *vcpu, 42998dd2eee9SChao Peng struct kvm_page_fault *fault) 43008dd2eee9SChao Peng { 43018dd2eee9SChao Peng kvm_prepare_memory_fault_exit(vcpu, fault->gfn << PAGE_SHIFT, 43028dd2eee9SChao Peng PAGE_SIZE, fault->write, fault->exec, 43038dd2eee9SChao Peng fault->is_private); 43048dd2eee9SChao Peng } 43058dd2eee9SChao Peng 43068dd2eee9SChao Peng static int kvm_faultin_pfn_private(struct kvm_vcpu *vcpu, 43078dd2eee9SChao Peng struct kvm_page_fault *fault) 43088dd2eee9SChao Peng { 43098dd2eee9SChao Peng int max_order, r; 43108dd2eee9SChao Peng 43118dd2eee9SChao Peng if (!kvm_slot_can_be_private(fault->slot)) { 43128dd2eee9SChao Peng kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 43138dd2eee9SChao Peng return -EFAULT; 43148dd2eee9SChao Peng } 43158dd2eee9SChao Peng 43168dd2eee9SChao Peng r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn, 43178dd2eee9SChao Peng &max_order); 43188dd2eee9SChao Peng if (r) { 43198dd2eee9SChao Peng kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 43208dd2eee9SChao Peng return r; 43218dd2eee9SChao Peng } 43228dd2eee9SChao Peng 43238dd2eee9SChao Peng fault->max_level = min(kvm_max_level_for_order(max_order), 43248dd2eee9SChao Peng fault->max_level); 43258dd2eee9SChao Peng fault->map_writable = !(fault->slot->flags & KVM_MEM_READONLY); 43268dd2eee9SChao Peng 43278dd2eee9SChao Peng return RET_PF_CONTINUE; 43288dd2eee9SChao Peng } 43298dd2eee9SChao Peng 4330ba6e3fe2SDavid Matlack static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4331c50d8ae3SPaolo Bonzini { 4332e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4333c50d8ae3SPaolo Bonzini bool async; 4334c50d8ae3SPaolo Bonzini 4335e0c37868SSean Christopherson /* 4336e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4337e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4338e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4339e0c37868SSean Christopherson */ 4340e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 43415276c616SSean Christopherson return RET_PF_RETRY; 4342e0c37868SSean Christopherson 43439cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4344c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 43459cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4346e710c5f6SDavid Matlack fault->slot = NULL; 43473647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 43483647cd04SPaolo Bonzini fault->map_writable = false; 43495276c616SSean Christopherson return RET_PF_CONTINUE; 4350c50d8ae3SPaolo Bonzini } 43519cc13d60SMaxim Levitsky /* 43529cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 43539cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 43549cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 43559cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 43569cc13d60SMaxim Levitsky */ 43579cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 43585276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 43595276c616SSean Christopherson return RET_PF_EMULATE; 43609cc13d60SMaxim Levitsky } 4361c50d8ae3SPaolo Bonzini 43628dd2eee9SChao Peng if (fault->is_private != kvm_mem_is_private(vcpu->kvm, fault->gfn)) { 43638dd2eee9SChao Peng kvm_mmu_prepare_memory_fault_exit(vcpu, fault); 43648dd2eee9SChao Peng return -EFAULT; 43658dd2eee9SChao Peng } 43668dd2eee9SChao Peng 43678dd2eee9SChao Peng if (fault->is_private) 43688dd2eee9SChao Peng return kvm_faultin_pfn_private(vcpu, fault); 43698dd2eee9SChao Peng 4370c50d8ae3SPaolo Bonzini async = false; 4371c8b88b33SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, 43723647cd04SPaolo Bonzini fault->write, &fault->map_writable, 43733647cd04SPaolo Bonzini &fault->hva); 4374c50d8ae3SPaolo Bonzini if (!async) 43755276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4376c50d8ae3SPaolo Bonzini 43772839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 43783647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 43793647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 43801685c0f3SMingwei Zhang trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4381c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 43825276c616SSean Christopherson return RET_PF_RETRY; 43835276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 43845276c616SSean Christopherson return RET_PF_RETRY; 43855276c616SSean Christopherson } 4386c50d8ae3SPaolo Bonzini } 4387c50d8ae3SPaolo Bonzini 438876657687SPeter Xu /* 438976657687SPeter Xu * Allow gup to bail on pending non-fatal signals when it's also allowed 439076657687SPeter Xu * to wait for IO. Note, gup always bails if it is unable to quickly 439176657687SPeter Xu * get a page and a fatal signal, i.e. SIGKILL, is pending. 439276657687SPeter Xu */ 439376657687SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, 43943647cd04SPaolo Bonzini fault->write, &fault->map_writable, 43953647cd04SPaolo Bonzini &fault->hva); 43965276c616SSean Christopherson return RET_PF_CONTINUE; 4397c50d8ae3SPaolo Bonzini } 4398c50d8ae3SPaolo Bonzini 4399354c908cSDavid Matlack static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 4400354c908cSDavid Matlack unsigned int access) 4401ba6e3fe2SDavid Matlack { 440256c3a4e4SDavid Matlack int ret; 440356c3a4e4SDavid Matlack 4404ba6e3fe2SDavid Matlack fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4405ba6e3fe2SDavid Matlack smp_rmb(); 4406ba6e3fe2SDavid Matlack 440756c3a4e4SDavid Matlack ret = __kvm_faultin_pfn(vcpu, fault); 440856c3a4e4SDavid Matlack if (ret != RET_PF_CONTINUE) 440956c3a4e4SDavid Matlack return ret; 441056c3a4e4SDavid Matlack 441156c3a4e4SDavid Matlack if (unlikely(is_error_pfn(fault->pfn))) 4412cd08d178SDavid Matlack return kvm_handle_error_pfn(vcpu, fault); 441356c3a4e4SDavid Matlack 4414354c908cSDavid Matlack if (unlikely(!fault->slot)) 4415354c908cSDavid Matlack return kvm_handle_noslot_fault(vcpu, fault, access); 4416354c908cSDavid Matlack 441756c3a4e4SDavid Matlack return RET_PF_CONTINUE; 4418ba6e3fe2SDavid Matlack } 4419ba6e3fe2SDavid Matlack 4420a955cad8SSean Christopherson /* 4421a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4422a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4423a955cad8SSean Christopherson */ 4424a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4425ba6e3fe2SDavid Matlack struct kvm_page_fault *fault) 4426a955cad8SSean Christopherson { 4427c5f2d564SSean Christopherson struct kvm_mmu_page *sp = root_to_sp(vcpu->arch.mmu->root.hpa); 442818c841e1SSean Christopherson 442918c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 443018c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 443118c841e1SSean Christopherson return true; 443218c841e1SSean Christopherson 443318c841e1SSean Christopherson /* 443418c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 443518c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 443618c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 443718c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 443818c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 443918c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 444018c841e1SSean Christopherson */ 4441527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4442a955cad8SSean Christopherson return true; 4443a955cad8SSean Christopherson 4444a955cad8SSean Christopherson return fault->slot && 44458569992dSChao Peng mmu_invalidate_retry_gfn(vcpu->kvm, fault->mmu_seq, fault->gfn); 4446a955cad8SSean Christopherson } 4447a955cad8SSean Christopherson 44484326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4449c50d8ae3SPaolo Bonzini { 445083f06fa7SSean Christopherson int r; 4451c50d8ae3SPaolo Bonzini 44520e3223d8SSean Christopherson /* Dummy roots are used only for shadowing bad guest roots. */ 44530e3223d8SSean Christopherson if (WARN_ON_ONCE(kvm_mmu_is_dummy_root(vcpu->arch.mmu->root.hpa))) 44540e3223d8SSean Christopherson return RET_PF_RETRY; 44550e3223d8SSean Christopherson 4456b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4457c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4458c50d8ae3SPaolo Bonzini 44593c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4460c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4461c4371c2aSSean Christopherson return r; 446283291445SSean Christopherson 4463378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4464c50d8ae3SPaolo Bonzini if (r) 4465c50d8ae3SPaolo Bonzini return r; 4466c50d8ae3SPaolo Bonzini 4467354c908cSDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 44685276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4469367fd790SSean Christopherson return r; 4470367fd790SSean Christopherson 4471367fd790SSean Christopherson r = RET_PF_RETRY; 4472531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4473a2855afcSBen Gardon 4474ba6e3fe2SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 4475367fd790SSean Christopherson goto out_unlock; 4476a955cad8SSean Christopherson 44777bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 44787bd7ded6SSean Christopherson if (r) 4479367fd790SSean Christopherson goto out_unlock; 4480bb18842eSBen Gardon 44816c882ef4SDavid Matlack r = direct_map(vcpu, fault); 44820f90e1c1SSean Christopherson 4483367fd790SSean Christopherson out_unlock: 4484531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 44853647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4486367fd790SSean Christopherson return r; 4487c50d8ae3SPaolo Bonzini } 4488c50d8ae3SPaolo Bonzini 4489c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4490c501040aSPaolo Bonzini struct kvm_page_fault *fault) 44910f90e1c1SSean Christopherson { 44920f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 44934326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 44944326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 44950f90e1c1SSean Christopherson } 44960f90e1c1SSean Christopherson 4497c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4498c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4499c50d8ae3SPaolo Bonzini { 4500c50d8ae3SPaolo Bonzini int r = 1; 45019ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4502c50d8ae3SPaolo Bonzini 4503736c291cSSean Christopherson #ifndef CONFIG_X86_64 4504736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4505736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4506736c291cSSean Christopherson return -EFAULT; 4507736c291cSSean Christopherson #endif 4508736c291cSSean Christopherson 4509c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 45109ce372b3SVitaly Kuznetsov if (!flags) { 4511faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4512c50d8ae3SPaolo Bonzini 4513c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4514c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4515c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4516c50d8ae3SPaolo Bonzini insn_len); 45179ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 451868fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4519c50d8ae3SPaolo Bonzini local_irq_disable(); 45206bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4521c50d8ae3SPaolo Bonzini local_irq_enable(); 45229ce372b3SVitaly Kuznetsov } else { 45239ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4524c50d8ae3SPaolo Bonzini } 45259ce372b3SVitaly Kuznetsov 4526c50d8ae3SPaolo Bonzini return r; 4527c50d8ae3SPaolo Bonzini } 4528c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4529c50d8ae3SPaolo Bonzini 45309aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 45319aa8ab43SDavid Matlack static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, 45329aa8ab43SDavid Matlack struct kvm_page_fault *fault) 45339aa8ab43SDavid Matlack { 45349aa8ab43SDavid Matlack int r; 45359aa8ab43SDavid Matlack 45369aa8ab43SDavid Matlack if (page_fault_handle_page_track(vcpu, fault)) 45379aa8ab43SDavid Matlack return RET_PF_EMULATE; 45389aa8ab43SDavid Matlack 45399aa8ab43SDavid Matlack r = fast_page_fault(vcpu, fault); 45409aa8ab43SDavid Matlack if (r != RET_PF_INVALID) 45419aa8ab43SDavid Matlack return r; 45429aa8ab43SDavid Matlack 45439aa8ab43SDavid Matlack r = mmu_topup_memory_caches(vcpu, false); 45449aa8ab43SDavid Matlack if (r) 45459aa8ab43SDavid Matlack return r; 45469aa8ab43SDavid Matlack 45479aa8ab43SDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 45489aa8ab43SDavid Matlack if (r != RET_PF_CONTINUE) 45499aa8ab43SDavid Matlack return r; 45509aa8ab43SDavid Matlack 45519aa8ab43SDavid Matlack r = RET_PF_RETRY; 45529aa8ab43SDavid Matlack read_lock(&vcpu->kvm->mmu_lock); 45539aa8ab43SDavid Matlack 45549aa8ab43SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 45559aa8ab43SDavid Matlack goto out_unlock; 45569aa8ab43SDavid Matlack 45579aa8ab43SDavid Matlack r = kvm_tdp_mmu_map(vcpu, fault); 45589aa8ab43SDavid Matlack 45599aa8ab43SDavid Matlack out_unlock: 45609aa8ab43SDavid Matlack read_unlock(&vcpu->kvm->mmu_lock); 45619aa8ab43SDavid Matlack kvm_release_pfn_clean(fault->pfn); 45629aa8ab43SDavid Matlack return r; 45639aa8ab43SDavid Matlack } 45649aa8ab43SDavid Matlack #endif 45659aa8ab43SDavid Matlack 45661affe455SYan Zhao bool __kvm_mmu_honors_guest_mtrrs(bool vm_has_noncoherent_dma) 45671affe455SYan Zhao { 45681affe455SYan Zhao /* 45691affe455SYan Zhao * If host MTRRs are ignored (shadow_memtype_mask is non-zero), and the 45701affe455SYan Zhao * VM has non-coherent DMA (DMA doesn't snoop CPU caches), KVM's ABI is 45711affe455SYan Zhao * to honor the memtype from the guest's MTRRs so that guest accesses 45721affe455SYan Zhao * to memory that is DMA'd aren't cached against the guest's wishes. 45731affe455SYan Zhao * 45741affe455SYan Zhao * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 45751affe455SYan Zhao * e.g. KVM will force UC memtype for host MMIO. 45761affe455SYan Zhao */ 45771affe455SYan Zhao return vm_has_noncoherent_dma && shadow_memtype_mask; 45781affe455SYan Zhao } 45791affe455SYan Zhao 4580c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4581c50d8ae3SPaolo Bonzini { 4582d5e90a69SSean Christopherson /* 4583d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4584d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 45851affe455SYan Zhao * across the entire mapping. 4586d5e90a69SSean Christopherson */ 45871affe455SYan Zhao if (kvm_mmu_honors_guest_mtrrs(vcpu->kvm)) { 4588d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 45894326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 4590c667a3baSHou Wenlong gfn_t base = gfn_round_for_level(fault->gfn, 4591c667a3baSHou Wenlong fault->max_level); 4592c50d8ae3SPaolo Bonzini 4593cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4594cb9b88c6SSean Christopherson break; 4595d5e90a69SSean Christopherson } 4596c50d8ae3SPaolo Bonzini } 4597c50d8ae3SPaolo Bonzini 45989aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 45999aa8ab43SDavid Matlack if (tdp_mmu_enabled) 46009aa8ab43SDavid Matlack return kvm_tdp_mmu_page_fault(vcpu, fault); 46019aa8ab43SDavid Matlack #endif 46029aa8ab43SDavid Matlack 46034326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4604c50d8ae3SPaolo Bonzini } 4605c50d8ae3SPaolo Bonzini 460684a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4607c50d8ae3SPaolo Bonzini { 4608c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4609c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4610c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 4611c50d8ae3SPaolo Bonzini } 4612c50d8ae3SPaolo Bonzini 4613be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 46140be44352SSean Christopherson union kvm_mmu_page_role role) 46150be44352SSean Christopherson { 4616c30e000eSSean Christopherson struct kvm_mmu_page *sp; 4617c30e000eSSean Christopherson 4618c30e000eSSean Christopherson if (!VALID_PAGE(root->hpa)) 4619c30e000eSSean Christopherson return false; 4620c30e000eSSean Christopherson 4621c30e000eSSean Christopherson if (!role.direct && pgd != root->pgd) 4622c30e000eSSean Christopherson return false; 4623c30e000eSSean Christopherson 4624c30e000eSSean Christopherson sp = root_to_sp(root->hpa); 4625c30e000eSSean Christopherson if (WARN_ON_ONCE(!sp)) 4626c30e000eSSean Christopherson return false; 4627c30e000eSSean Christopherson 4628c30e000eSSean Christopherson return role.word == sp->role.word; 46290be44352SSean Christopherson } 46300be44352SSean Christopherson 4631c50d8ae3SPaolo Bonzini /* 46325499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 46335499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 46345499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 46355499ea73SPaolo Bonzini * true is returned. 46365499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 46375499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4638c50d8ae3SPaolo Bonzini */ 46395499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 46405499ea73SPaolo Bonzini gpa_t new_pgd, 4641c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4642c50d8ae3SPaolo Bonzini { 4643c50d8ae3SPaolo Bonzini uint i; 4644c50d8ae3SPaolo Bonzini 4645b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 46460be44352SSean Christopherson return true; 46470be44352SSean Christopherson 4648c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 46495499ea73SPaolo Bonzini /* 46505499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 46515499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 46525499ea73SPaolo Bonzini * 0 C 1 2 3 46535499ea73SPaolo Bonzini * 1 C 0 2 3 46545499ea73SPaolo Bonzini * 2 C 0 1 3 46555499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 46565499ea73SPaolo Bonzini */ 4657b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4658b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 46595499ea73SPaolo Bonzini return true; 4660c50d8ae3SPaolo Bonzini } 4661c50d8ae3SPaolo Bonzini 46625499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 46635499ea73SPaolo Bonzini return false; 4664c50d8ae3SPaolo Bonzini } 4665c50d8ae3SPaolo Bonzini 4666c50d8ae3SPaolo Bonzini /* 46675499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 46685499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 46695499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 46705499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 46715499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 46725499ea73SPaolo Bonzini */ 46735499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 46745499ea73SPaolo Bonzini gpa_t new_pgd, 46755499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 46765499ea73SPaolo Bonzini { 46775499ea73SPaolo Bonzini uint i; 46785499ea73SPaolo Bonzini 46795499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 46805499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 46815499ea73SPaolo Bonzini goto hit; 46825499ea73SPaolo Bonzini 46835499ea73SPaolo Bonzini return false; 46845499ea73SPaolo Bonzini 46855499ea73SPaolo Bonzini hit: 46865499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 46875499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 46885499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 46895499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 46905499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 46915499ea73SPaolo Bonzini return true; 46925499ea73SPaolo Bonzini } 46935499ea73SPaolo Bonzini 46945499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 46955499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 46965499ea73SPaolo Bonzini { 46975499ea73SPaolo Bonzini /* 46980e3223d8SSean Christopherson * Limit reuse to 64-bit hosts+VMs without "special" roots in order to 46990e3223d8SSean Christopherson * avoid having to deal with PDPTEs and other complexities. 4700c50d8ae3SPaolo Bonzini */ 4701c5f2d564SSean Christopherson if (VALID_PAGE(mmu->root.hpa) && !root_to_sp(mmu->root.hpa)) 47025499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4703c50d8ae3SPaolo Bonzini 47045499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 47055499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 47065499ea73SPaolo Bonzini else 47075499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4708c50d8ae3SPaolo Bonzini } 4709c50d8ae3SPaolo Bonzini 4710d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4711c50d8ae3SPaolo Bonzini { 47120c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 47137a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 47140c1c92f1SPaolo Bonzini 4715a7e48ef7SWei Liu /* 4716a7e48ef7SWei Liu * Return immediately if no usable root was found, kvm_mmu_reload() 4717a7e48ef7SWei Liu * will establish a valid root prior to the next VM-Enter. 4718a7e48ef7SWei Liu */ 4719a7e48ef7SWei Liu if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) 4720b869855bSSean Christopherson return; 4721c50d8ae3SPaolo Bonzini 4722c50d8ae3SPaolo Bonzini /* 4723b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4724b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4725527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4726527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4727b869855bSSean Christopherson */ 4728b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4729b869855bSSean Christopherson 4730b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4731b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4732b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4733b5129100SSean Christopherson } 4734b869855bSSean Christopherson 4735b869855bSSean Christopherson /* 4736b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4737b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4738b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4739b869855bSSean Christopherson * the shadow page tables. 4740c50d8ae3SPaolo Bonzini */ 4741c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4742c50d8ae3SPaolo Bonzini 4743daa5b6c1SBen Gardon /* 4744daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4745daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4746daa5b6c1SBen Gardon */ 4747c30e000eSSean Christopherson if (!new_role.direct) { 4748c30e000eSSean Christopherson struct kvm_mmu_page *sp = root_to_sp(vcpu->arch.mmu->root.hpa); 4749c30e000eSSean Christopherson 4750c30e000eSSean Christopherson if (!WARN_ON_ONCE(!sp)) 4751c30e000eSSean Christopherson __clear_sp_write_flooding_count(sp); 4752c30e000eSSean Christopherson } 4753c50d8ae3SPaolo Bonzini } 4754be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4755c50d8ae3SPaolo Bonzini 4756c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4757c3e5e415SLai Jiangshan unsigned int access) 4758c50d8ae3SPaolo Bonzini { 4759c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4760c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4761c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4762c50d8ae3SPaolo Bonzini return true; 4763c50d8ae3SPaolo Bonzini } 4764c50d8ae3SPaolo Bonzini 4765c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4766c50d8ae3SPaolo Bonzini return true; 4767c50d8ae3SPaolo Bonzini } 4768c50d8ae3SPaolo Bonzini 4769c50d8ae3SPaolo Bonzini return false; 4770c50d8ae3SPaolo Bonzini } 4771c50d8ae3SPaolo Bonzini 4772c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4773c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4774c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4775c50d8ae3SPaolo Bonzini #undef PTTYPE 4776c50d8ae3SPaolo Bonzini 4777c50d8ae3SPaolo Bonzini #define PTTYPE 64 4778c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4779c50d8ae3SPaolo Bonzini #undef PTTYPE 4780c50d8ae3SPaolo Bonzini 4781c50d8ae3SPaolo Bonzini #define PTTYPE 32 4782c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4783c50d8ae3SPaolo Bonzini #undef PTTYPE 4784c50d8ae3SPaolo Bonzini 4785f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 4786f3d90f90SSean Christopherson u64 pa_bits_rsvd, int level, bool nx, 4787f3d90f90SSean Christopherson bool gbpages, bool pse, bool amd) 4788c50d8ae3SPaolo Bonzini { 4789c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4790c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 47915b7f575cSSean Christopherson u64 high_bits_rsvd; 4792c50d8ae3SPaolo Bonzini 4793c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4794c50d8ae3SPaolo Bonzini 4795c50d8ae3SPaolo Bonzini if (!gbpages) 4796c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4797c50d8ae3SPaolo Bonzini 47985b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 47995b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 48005b7f575cSSean Christopherson else 48015b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 48025b7f575cSSean Christopherson 48035b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 48045b7f575cSSean Christopherson if (!nx) 48055b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 48065b7f575cSSean Christopherson 4807c50d8ae3SPaolo Bonzini /* 4808c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4809c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4810c50d8ae3SPaolo Bonzini */ 4811c50d8ae3SPaolo Bonzini if (amd) 4812c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4813c50d8ae3SPaolo Bonzini 4814c50d8ae3SPaolo Bonzini switch (level) { 4815c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4816c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4817c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4818c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4819c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4820c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4821c50d8ae3SPaolo Bonzini 4822c50d8ae3SPaolo Bonzini if (!pse) { 4823c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4824c50d8ae3SPaolo Bonzini break; 4825c50d8ae3SPaolo Bonzini } 4826c50d8ae3SPaolo Bonzini 4827c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4828c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4829c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4830c50d8ae3SPaolo Bonzini else 4831c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4832c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4833c50d8ae3SPaolo Bonzini break; 4834c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 48355b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 48365b7f575cSSean Christopherson high_bits_rsvd | 48375b7f575cSSean Christopherson rsvd_bits(5, 8) | 48385b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 48395b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 48405b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 48415b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4842c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4843c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4844c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4845c50d8ae3SPaolo Bonzini break; 4846c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 48475b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 48485b7f575cSSean Christopherson nonleaf_bit8_rsvd | 48495b7f575cSSean Christopherson rsvd_bits(7, 7); 4850c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4851c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4852df561f66SGustavo A. R. Silva fallthrough; 4853c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 48545b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 48555b7f575cSSean Christopherson nonleaf_bit8_rsvd | 48565b7f575cSSean Christopherson rsvd_bits(7, 7); 48575b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 48585b7f575cSSean Christopherson gbpages_bit_rsvd; 48595b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 48605b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4861c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4862c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 48635b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 48645b7f575cSSean Christopherson gbpages_bit_rsvd | 4865c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 48665b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4867c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4868c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4869c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4870c50d8ae3SPaolo Bonzini break; 4871c50d8ae3SPaolo Bonzini } 4872c50d8ae3SPaolo Bonzini } 4873c50d8ae3SPaolo Bonzini 4874c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4875c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4876c50d8ae3SPaolo Bonzini { 4877b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 48785b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 48794d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 4880ccf31d6eSSean Christopherson guest_can_use(vcpu, X86_FEATURE_GBPAGES), 48814e9c0d80SSean Christopherson is_cr4_pse(context), 488223493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4883c50d8ae3SPaolo Bonzini } 4884c50d8ae3SPaolo Bonzini 4885f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 4886f3d90f90SSean Christopherson u64 pa_bits_rsvd, bool execonly, 4887f3d90f90SSean Christopherson int huge_page_level) 4888c50d8ae3SPaolo Bonzini { 48895b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 489084ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4891c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4892c50d8ae3SPaolo Bonzini 489384ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 489484ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 489584ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 489684ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 489784ea5c09SLai Jiangshan 48985b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 48995b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 490084ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 490184ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 49025b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4903c50d8ae3SPaolo Bonzini 4904c50d8ae3SPaolo Bonzini /* large page */ 4905c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4906c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 490784ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 490884ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4909c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4910c50d8ae3SPaolo Bonzini 4911c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4912c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4913c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4914c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4915c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4916c50d8ae3SPaolo Bonzini if (!execonly) { 4917c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4918c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4919c50d8ae3SPaolo Bonzini } 4920c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4921c50d8ae3SPaolo Bonzini } 4922c50d8ae3SPaolo Bonzini 4923c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 492484ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4925c50d8ae3SPaolo Bonzini { 4926c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 492784ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 492884ea5c09SLai Jiangshan huge_page_level); 4929c50d8ae3SPaolo Bonzini } 4930c50d8ae3SPaolo Bonzini 49316f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 49326f8e65a6SSean Christopherson { 49336f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 49346f8e65a6SSean Christopherson } 49356f8e65a6SSean Christopherson 4936c50d8ae3SPaolo Bonzini /* 4937c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4938c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4939c50d8ae3SPaolo Bonzini * follow the features in guest. 4940c50d8ae3SPaolo Bonzini */ 494116be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 494216be1d12SSean Christopherson struct kvm_mmu *context) 4943c50d8ae3SPaolo Bonzini { 49448c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 49458c985b2dSSean Christopherson bool is_amd = true; 49468c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 49478c985b2dSSean Christopherson bool is_pse = false; 4948c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4949c50d8ae3SPaolo Bonzini int i; 4950c50d8ae3SPaolo Bonzini 4951a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 49528c985b2dSSean Christopherson 4953c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4954b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4955a972e29cSPaolo Bonzini context->root_role.level, 49567a458f0eSPaolo Bonzini context->root_role.efer_nx, 4957ccf31d6eSSean Christopherson guest_can_use(vcpu, X86_FEATURE_GBPAGES), 4958ccf31d6eSSean Christopherson is_pse, is_amd); 4959c50d8ae3SPaolo Bonzini 4960c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4961c50d8ae3SPaolo Bonzini return; 4962c50d8ae3SPaolo Bonzini 4963a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4964e54f1ff2SKai Huang /* 4965e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4966e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4967e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4968e54f1ff2SKai Huang * not allowed to be set. 4969e54f1ff2SKai Huang */ 4970e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4971e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4972e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4973e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4974c50d8ae3SPaolo Bonzini } 4975c50d8ae3SPaolo Bonzini 4976c50d8ae3SPaolo Bonzini } 4977c50d8ae3SPaolo Bonzini 4978c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4979c50d8ae3SPaolo Bonzini { 4980c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4981c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4982c50d8ae3SPaolo Bonzini } 4983c50d8ae3SPaolo Bonzini 4984c50d8ae3SPaolo Bonzini /* 4985c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4986c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4987c50d8ae3SPaolo Bonzini */ 4988f3d90f90SSean Christopherson static void reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4989c50d8ae3SPaolo Bonzini { 4990c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4991c50d8ae3SPaolo Bonzini int i; 4992c50d8ae3SPaolo Bonzini 4993c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4994c50d8ae3SPaolo Bonzini 4995c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4996b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 49976c6ab524SSean Christopherson context->root_role.level, true, 4998c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 49998c985b2dSSean Christopherson false, true); 5000c50d8ae3SPaolo Bonzini else 5001c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 500284ea5c09SLai Jiangshan reserved_hpa_bits(), false, 500384ea5c09SLai Jiangshan max_huge_page_level); 5004c50d8ae3SPaolo Bonzini 5005c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 5006c50d8ae3SPaolo Bonzini return; 5007c50d8ae3SPaolo Bonzini 5008a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 5009c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 5010c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 5011c50d8ae3SPaolo Bonzini } 5012c50d8ae3SPaolo Bonzini } 5013c50d8ae3SPaolo Bonzini 5014c50d8ae3SPaolo Bonzini /* 5015c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 5016c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 5017c50d8ae3SPaolo Bonzini */ 5018c50d8ae3SPaolo Bonzini static void 5019e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 5020c50d8ae3SPaolo Bonzini { 5021c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 502284ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 502384ea5c09SLai Jiangshan max_huge_page_level); 5024c50d8ae3SPaolo Bonzini } 5025c50d8ae3SPaolo Bonzini 5026c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 5027c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 5028c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 5029c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 5030c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 5031c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 5032c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 5033c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 5034c50d8ae3SPaolo Bonzini 5035c50d8ae3SPaolo Bonzini 5036c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 5037c50d8ae3SPaolo Bonzini { 5038c50d8ae3SPaolo Bonzini unsigned byte; 5039c50d8ae3SPaolo Bonzini 5040c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 5041c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 5042c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 5043c50d8ae3SPaolo Bonzini 5044c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 5045c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 5046c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 504790599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 5048c50d8ae3SPaolo Bonzini 5049c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 5050c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 5051c50d8ae3SPaolo Bonzini 5052c50d8ae3SPaolo Bonzini /* 5053c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 5054c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 5055c50d8ae3SPaolo Bonzini */ 5056c50d8ae3SPaolo Bonzini 5057c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 5058c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 5059c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 5060c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 5061c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 5062c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 5063c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 5064c50d8ae3SPaolo Bonzini u8 smepf = 0; 5065c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 5066c50d8ae3SPaolo Bonzini u8 smapf = 0; 5067c50d8ae3SPaolo Bonzini 5068c50d8ae3SPaolo Bonzini if (!ept) { 5069c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 5070c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 5071c50d8ae3SPaolo Bonzini 5072c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 507390599c28SSean Christopherson if (!efer_nx) 5074c50d8ae3SPaolo Bonzini ff = 0; 5075c50d8ae3SPaolo Bonzini 5076c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 5077c50d8ae3SPaolo Bonzini if (!cr0_wp) 5078c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 5079c50d8ae3SPaolo Bonzini 5080c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 5081c50d8ae3SPaolo Bonzini if (cr4_smep) 5082c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 5083c50d8ae3SPaolo Bonzini 5084c50d8ae3SPaolo Bonzini /* 5085c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 5086c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 5087c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 5088c50d8ae3SPaolo Bonzini * conditions are true: 5089c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 5090c50d8ae3SPaolo Bonzini * - A user page is accessed 5091c50d8ae3SPaolo Bonzini * - The access is not a fetch 50924f4aa80eSLai Jiangshan * - The access is supervisor mode 50934f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 5094c50d8ae3SPaolo Bonzini * 509594b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 509694b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 5097c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 5098c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 5099c50d8ae3SPaolo Bonzini */ 5100c50d8ae3SPaolo Bonzini if (cr4_smap) 5101c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 5102c50d8ae3SPaolo Bonzini } 5103c50d8ae3SPaolo Bonzini 5104c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 5105c50d8ae3SPaolo Bonzini } 5106c50d8ae3SPaolo Bonzini } 5107c50d8ae3SPaolo Bonzini 5108c50d8ae3SPaolo Bonzini /* 5109c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 5110c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 5111c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 5112c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 5113c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 5114c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 5115c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 5116c50d8ae3SPaolo Bonzini * 5117c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 5118c50d8ae3SPaolo Bonzini * page tables and the machine state: 5119c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 5120c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 5121c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 5122c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 5123c50d8ae3SPaolo Bonzini * 5124c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 5125c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 5126c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 5127c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 5128c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 5129c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 5130c50d8ae3SPaolo Bonzini * only will be masked away. 5131c50d8ae3SPaolo Bonzini */ 51322e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 5133c50d8ae3SPaolo Bonzini { 5134c50d8ae3SPaolo Bonzini unsigned bit; 5135c50d8ae3SPaolo Bonzini bool wp; 5136c50d8ae3SPaolo Bonzini 5137c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 5138a3ca5281SChenyi Qiang 5139a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 5140c50d8ae3SPaolo Bonzini return; 5141c50d8ae3SPaolo Bonzini 51422e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 5143c50d8ae3SPaolo Bonzini 5144c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 5145c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 5146c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 5147c50d8ae3SPaolo Bonzini 5148c50d8ae3SPaolo Bonzini pfec = bit << 1; 5149c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 5150c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 5151c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 5152c50d8ae3SPaolo Bonzini 5153c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 5154c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 5155c50d8ae3SPaolo Bonzini 5156c50d8ae3SPaolo Bonzini /* 5157c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 5158c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 5159c50d8ae3SPaolo Bonzini */ 5160c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 5161c50d8ae3SPaolo Bonzini /* 5162c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 5163c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 5164c50d8ae3SPaolo Bonzini */ 5165c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 5166c50d8ae3SPaolo Bonzini 5167c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 5168c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 5169c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 5170c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 5171c50d8ae3SPaolo Bonzini 5172c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 5173c50d8ae3SPaolo Bonzini } 5174c50d8ae3SPaolo Bonzini } 5175c50d8ae3SPaolo Bonzini 5176533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 5177533f9a4bSSean Christopherson struct kvm_mmu *mmu) 5178c50d8ae3SPaolo Bonzini { 5179533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 5180533f9a4bSSean Christopherson return; 5181c50d8ae3SPaolo Bonzini 5182c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 5183533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 5184533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 5185c50d8ae3SPaolo Bonzini } 5186c50d8ae3SPaolo Bonzini 5187fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 5188c50d8ae3SPaolo Bonzini { 5189c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 5190c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5191c3c6c9fcSLai Jiangshan context->sync_spte = paging64_sync_spte; 5192c50d8ae3SPaolo Bonzini } 5193c50d8ae3SPaolo Bonzini 519484a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 5195c50d8ae3SPaolo Bonzini { 5196c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 5197c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5198c3c6c9fcSLai Jiangshan context->sync_spte = paging32_sync_spte; 5199c50d8ae3SPaolo Bonzini } 5200c50d8ae3SPaolo Bonzini 5201f3d90f90SSean Christopherson static union kvm_cpu_role kvm_calc_cpu_role(struct kvm_vcpu *vcpu, 5202f3d90f90SSean Christopherson const struct kvm_mmu_role_regs *regs) 5203e5ed0fb0SPaolo Bonzini { 52047a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5205e5ed0fb0SPaolo Bonzini 5206e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 5207e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 5208e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 5209e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 5210e5ed0fb0SPaolo Bonzini 5211e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 5212e5ed0fb0SPaolo Bonzini role.base.direct = 1; 5213e5ed0fb0SPaolo Bonzini return role; 5214e5ed0fb0SPaolo Bonzini } 5215e5ed0fb0SPaolo Bonzini 5216e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 5217e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 5218e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 5219e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 5220e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 522160f3cb60SPaolo Bonzini 522260f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 522360f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 522460f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 522560f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 522660f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 522760f3cb60SPaolo Bonzini else 522860f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 5229e5ed0fb0SPaolo Bonzini 5230e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 5231e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 5232e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 5233e5ed0fb0SPaolo Bonzini 5234e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 5235e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 5236e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 5237e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 5238e5ed0fb0SPaolo Bonzini return role; 5239e5ed0fb0SPaolo Bonzini } 5240e5ed0fb0SPaolo Bonzini 5241cf9f4c0eSSean Christopherson void __kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu, 5242cf9f4c0eSSean Christopherson struct kvm_mmu *mmu) 5243cf9f4c0eSSean Christopherson { 5244cf9f4c0eSSean Christopherson const bool cr0_wp = kvm_is_cr0_bit_set(vcpu, X86_CR0_WP); 5245cf9f4c0eSSean Christopherson 5246cf9f4c0eSSean Christopherson BUILD_BUG_ON((KVM_MMU_CR0_ROLE_BITS & KVM_POSSIBLE_CR0_GUEST_BITS) != X86_CR0_WP); 5247cf9f4c0eSSean Christopherson BUILD_BUG_ON((KVM_MMU_CR4_ROLE_BITS & KVM_POSSIBLE_CR4_GUEST_BITS)); 5248cf9f4c0eSSean Christopherson 5249cf9f4c0eSSean Christopherson if (is_cr0_wp(mmu) == cr0_wp) 5250cf9f4c0eSSean Christopherson return; 5251cf9f4c0eSSean Christopherson 5252cf9f4c0eSSean Christopherson mmu->cpu_role.base.cr0_wp = cr0_wp; 5253cf9f4c0eSSean Christopherson reset_guest_paging_metadata(vcpu, mmu); 5254cf9f4c0eSSean Christopherson } 5255cf9f4c0eSSean Christopherson 5256d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 5257d468d94bSSean Christopherson { 5258746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5259746700d2SWei Huang if (tdp_root_level) 5260746700d2SWei Huang return tdp_root_level; 5261746700d2SWei Huang 5262d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 526383013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5264d468d94bSSean Christopherson return 4; 5265d468d94bSSean Christopherson 526683013059SSean Christopherson return max_tdp_level; 5267d468d94bSSean Christopherson } 5268d468d94bSSean Christopherson 52697a458f0eSPaolo Bonzini static union kvm_mmu_page_role 52708626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 52717a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5272c50d8ae3SPaolo Bonzini { 52737a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5274c50d8ae3SPaolo Bonzini 52757a458f0eSPaolo Bonzini role.access = ACC_ALL; 52767a458f0eSPaolo Bonzini role.cr0_wp = true; 52777a458f0eSPaolo Bonzini role.efer_nx = true; 52787a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 52797a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 528054275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 52817a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 52827a458f0eSPaolo Bonzini role.direct = true; 52837a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5284c50d8ae3SPaolo Bonzini 5285c50d8ae3SPaolo Bonzini return role; 5286c50d8ae3SPaolo Bonzini } 5287c50d8ae3SPaolo Bonzini 528839e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5289a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5290c50d8ae3SPaolo Bonzini { 52918c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 52927a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5293c50d8ae3SPaolo Bonzini 5294e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 52957a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5296c50d8ae3SPaolo Bonzini return; 5297c50d8ae3SPaolo Bonzini 5298e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 52997a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 53007a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5301c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 53022fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5303c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5304c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5305c50d8ae3SPaolo Bonzini 530636f26787SSean Christopherson if (!is_cr0_pg(context)) 5307c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 530836f26787SSean Christopherson else if (is_cr4_pae(context)) 5309c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5310f4bd6f73SSean Christopherson else 5311c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5312c50d8ae3SPaolo Bonzini 5313533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5314e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5315c50d8ae3SPaolo Bonzini } 5316c50d8ae3SPaolo Bonzini 53178c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 53187a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 53197a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5320c50d8ae3SPaolo Bonzini { 5321e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 53227a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 532318db1b17SSean Christopherson return; 5324c50d8ae3SPaolo Bonzini 5325e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 53267a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 532718db1b17SSean Christopherson 532836f26787SSean Christopherson if (!is_cr0_pg(context)) 532984a16226SSean Christopherson nonpaging_init_context(context); 533036f26787SSean Christopherson else if (is_cr4_pae(context)) 5331fe660f72SSean Christopherson paging64_init_context(context); 5332c50d8ae3SPaolo Bonzini else 533384a16226SSean Christopherson paging32_init_context(context); 5334c50d8ae3SPaolo Bonzini 5335533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5336c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5337c50d8ae3SPaolo Bonzini } 53380f04a2acSVitaly Kuznetsov 5339594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5340a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 53410f04a2acSVitaly Kuznetsov { 53428c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 534356b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 534456b321f9SPaolo Bonzini 534556b321f9SPaolo Bonzini root_role = cpu_role.base; 534656b321f9SPaolo Bonzini 534756b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 534856b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 534956b321f9SPaolo Bonzini 535056b321f9SPaolo Bonzini /* 535156b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 535256b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 535356b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 535456b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 535556b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 535656b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 535756b321f9SPaolo Bonzini * MMU contexts. 535856b321f9SPaolo Bonzini */ 535956b321f9SPaolo Bonzini root_role.efer_nx = true; 53600f04a2acSVitaly Kuznetsov 53617a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 53620f04a2acSVitaly Kuznetsov } 53630f04a2acSVitaly Kuznetsov 5364dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5365dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 53660f04a2acSVitaly Kuznetsov { 53678c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5368594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5369594e91a1SSean Christopherson .cr0 = cr0, 537028f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5371594e91a1SSean Christopherson .efer = efer, 5372594e91a1SSean Christopherson }; 53737a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 537456b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 537556b321f9SPaolo Bonzini 537656b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 537756b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 537856b321f9SPaolo Bonzini 537956b321f9SPaolo Bonzini root_role = cpu_role.base; 538056b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 538184e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 538284e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 538384e5ffd0SLai Jiangshan root_role.passthrough = 1; 53840f04a2acSVitaly Kuznetsov 53857a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5386d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 53870f04a2acSVitaly Kuznetsov } 53880f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5389c50d8ae3SPaolo Bonzini 53907a7ae829SPaolo Bonzini static union kvm_cpu_role 5391c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5392bb1fcc70SSean Christopherson bool execonly, u8 level) 5393c50d8ae3SPaolo Bonzini { 53947a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5395c50d8ae3SPaolo Bonzini 5396daed87b8SPaolo Bonzini /* 5397daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5398daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5399daed87b8SPaolo Bonzini */ 5400daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5401bb1fcc70SSean Christopherson role.base.level = level; 5402bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5403c50d8ae3SPaolo Bonzini role.base.direct = false; 5404c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5405c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5406c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5407c50d8ae3SPaolo Bonzini 5408cd6767c3SSean Christopherson role.ext.word = 0; 5409c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5410cd6767c3SSean Christopherson role.ext.valid = 1; 5411c50d8ae3SPaolo Bonzini 5412c50d8ae3SPaolo Bonzini return role; 5413c50d8ae3SPaolo Bonzini } 5414c50d8ae3SPaolo Bonzini 5415c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5416cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5417cc022ae1SLai Jiangshan gpa_t new_eptp) 5418c50d8ae3SPaolo Bonzini { 54198c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5420bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 54217a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5422c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5423bb1fcc70SSean Christopherson execonly, level); 5424c50d8ae3SPaolo Bonzini 5425e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5426e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5427e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 54287a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 542918db1b17SSean Christopherson 5430c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5431c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5432c3c6c9fcSLai Jiangshan context->sync_spte = ept_sync_spte; 5433347a0d0dSPaolo Bonzini 5434c596f147SSean Christopherson update_permission_bitmask(context, true); 543528f091bcSPaolo Bonzini context->pkru_mask = 0; 5436cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5437e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5438c50d8ae3SPaolo Bonzini } 54393cffc89dSPaolo Bonzini 5440d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 54413cffc89dSPaolo Bonzini } 5442c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5443c50d8ae3SPaolo Bonzini 544439e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5445a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5446c50d8ae3SPaolo Bonzini { 54478c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5448c50d8ae3SPaolo Bonzini 5449a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5450929d1cfaSPaolo Bonzini 54512fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5452c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5453c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5454c50d8ae3SPaolo Bonzini } 5455c50d8ae3SPaolo Bonzini 545639e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5457a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5458c50d8ae3SPaolo Bonzini { 5459c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5460c50d8ae3SPaolo Bonzini 5461e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5462c50d8ae3SPaolo Bonzini return; 5463c50d8ae3SPaolo Bonzini 5464e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 54652fdcc1b3SPaolo Bonzini g_context->get_guest_pgd = get_guest_cr3; 5466c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5467c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5468c50d8ae3SPaolo Bonzini 5469c50d8ae3SPaolo Bonzini /* 54705efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 54715efac074SPaolo Bonzini * SPTEs. 54725efac074SPaolo Bonzini */ 54739fd4a4e3SLai Jiangshan g_context->sync_spte = NULL; 54745efac074SPaolo Bonzini 54755efac074SPaolo Bonzini /* 5476c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5477c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5478c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5479c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5480c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5481c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5482c50d8ae3SPaolo Bonzini */ 5483fa4b5588SSean Christopherson if (!is_paging(vcpu)) 54841f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5485fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 54861f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5487fa4b5588SSean Christopherson else if (is_pae(vcpu)) 54881f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5489fa4b5588SSean Christopherson else 54901f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5491fa4b5588SSean Christopherson 5492533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5493c50d8ae3SPaolo Bonzini } 5494c50d8ae3SPaolo Bonzini 5495c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5496c50d8ae3SPaolo Bonzini { 549739e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5498a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 549939e7e2bfSPaolo Bonzini 5500c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5501a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5502c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5503a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5504c50d8ae3SPaolo Bonzini else 5505a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5506c50d8ae3SPaolo Bonzini } 5507c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5508c50d8ae3SPaolo Bonzini 550949c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 551049c6f875SSean Christopherson { 551149c6f875SSean Christopherson /* 551249c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 551349c6f875SSean Christopherson * information is factored into reserved bit calculations. 5514feb627e8SVitaly Kuznetsov * 5515feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5516feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5517feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5518feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5519338068b5SSean Christopherson * gfn_write_track (see struct kvm_mmu_page_role comments). For now 5520338068b5SSean Christopherson * that problem is swept under the rug; KVM's CPUID API is horrific and 5521feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 552249c6f875SSean Christopherson */ 55237a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 55247a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 55257a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5526e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5527e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5528e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 552949c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 553063f5a190SSean Christopherson 553163f5a190SSean Christopherson /* 5532feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5533feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 553463f5a190SSean Christopherson */ 5535fb3146b4SSean Christopherson KVM_BUG_ON(kvm_vcpu_has_run(vcpu), vcpu->kvm); 553649c6f875SSean Christopherson } 553749c6f875SSean Christopherson 5538c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5539c50d8ae3SPaolo Bonzini { 5540c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5541c9060662SSean Christopherson kvm_init_mmu(vcpu); 5542c50d8ae3SPaolo Bonzini } 5543c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5544c50d8ae3SPaolo Bonzini 5545c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5546c50d8ae3SPaolo Bonzini { 5547c50d8ae3SPaolo Bonzini int r; 5548c50d8ae3SPaolo Bonzini 5549347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5550c50d8ae3SPaolo Bonzini if (r) 5551c50d8ae3SPaolo Bonzini goto out; 5552748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5553c50d8ae3SPaolo Bonzini if (r) 5554c50d8ae3SPaolo Bonzini goto out; 5555347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 55566e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 55576e6ec584SSean Christopherson else 55586e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5559c50d8ae3SPaolo Bonzini if (r) 5560c50d8ae3SPaolo Bonzini goto out; 5561a91f387bSSean Christopherson 5562a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5563a91f387bSSean Christopherson 5564727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5565db01416bSSean Christopherson 5566db01416bSSean Christopherson /* 5567db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5568db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5569db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5570db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5571db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5572db01416bSSean Christopherson */ 5573e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5574c50d8ae3SPaolo Bonzini out: 5575c50d8ae3SPaolo Bonzini return r; 5576c50d8ae3SPaolo Bonzini } 5577c50d8ae3SPaolo Bonzini 5578c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5579c50d8ae3SPaolo Bonzini { 55800c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 55810c1c92f1SPaolo Bonzini 55820c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 558320ba462dSSean Christopherson WARN_ON_ONCE(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 55840c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 558520ba462dSSean Christopherson WARN_ON_ONCE(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 55866d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5587c50d8ae3SPaolo Bonzini } 5588c50d8ae3SPaolo Bonzini 5589527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5590527d5cd7SSean Christopherson { 5591527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5592527d5cd7SSean Christopherson 5593527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5594527d5cd7SSean Christopherson return false; 5595527d5cd7SSean Christopherson 5596527d5cd7SSean Christopherson /* 5597527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 55980e3223d8SSean Christopherson * have an associated shadow page, as it's impossible to determine if 55990e3223d8SSean Christopherson * such roots are fresh or stale. This does mean KVM will get false 5600527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5601527d5cd7SSean Christopherson * such false positives are relatively rare: 5602527d5cd7SSean Christopherson * 56030e3223d8SSean Christopherson * (a) only PAE paging and nested NPT have roots without shadow pages 56040e3223d8SSean Christopherson * (or any shadow paging flavor with a dummy root, see note below) 5605527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5606527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5607527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 56080e3223d8SSean Christopherson * 56090e3223d8SSean Christopherson * Note! Dummy roots are unique in that they are obsoleted by memslot 56100e3223d8SSean Christopherson * _creation_! See also FNAME(fetch). 5611527d5cd7SSean Christopherson */ 5612c5f2d564SSean Christopherson sp = root_to_sp(root_hpa); 5613527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5614527d5cd7SSean Christopherson } 5615527d5cd7SSean Christopherson 5616527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5617527d5cd7SSean Christopherson { 5618527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5619527d5cd7SSean Christopherson int i; 5620527d5cd7SSean Christopherson 5621527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5622527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5623527d5cd7SSean Christopherson 5624527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5625cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5626527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5627527d5cd7SSean Christopherson } 5628527d5cd7SSean Christopherson 5629527d5cd7SSean Christopherson if (roots_to_free) 5630527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5631527d5cd7SSean Christopherson } 5632527d5cd7SSean Christopherson 5633527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5634527d5cd7SSean Christopherson { 5635527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5636527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5637527d5cd7SSean Christopherson } 5638527d5cd7SSean Christopherson 5639c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5640c50d8ae3SPaolo Bonzini int *bytes) 5641c50d8ae3SPaolo Bonzini { 5642c50d8ae3SPaolo Bonzini u64 gentry = 0; 5643c50d8ae3SPaolo Bonzini int r; 5644c50d8ae3SPaolo Bonzini 5645c50d8ae3SPaolo Bonzini /* 5646c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5647c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5648c50d8ae3SPaolo Bonzini * when they have the same mode. 5649c50d8ae3SPaolo Bonzini */ 5650c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5651c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5652c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5653c50d8ae3SPaolo Bonzini *bytes = 8; 5654c50d8ae3SPaolo Bonzini } 5655c50d8ae3SPaolo Bonzini 5656c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5657c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5658c50d8ae3SPaolo Bonzini if (r) 5659c50d8ae3SPaolo Bonzini gentry = 0; 5660c50d8ae3SPaolo Bonzini } 5661c50d8ae3SPaolo Bonzini 5662c50d8ae3SPaolo Bonzini return gentry; 5663c50d8ae3SPaolo Bonzini } 5664c50d8ae3SPaolo Bonzini 5665c50d8ae3SPaolo Bonzini /* 5666c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5667c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5668c50d8ae3SPaolo Bonzini */ 5669c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5670c50d8ae3SPaolo Bonzini { 5671c50d8ae3SPaolo Bonzini /* 5672c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5673c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5674c50d8ae3SPaolo Bonzini */ 56753bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5676c50d8ae3SPaolo Bonzini return false; 5677c50d8ae3SPaolo Bonzini 5678c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5679c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5680c50d8ae3SPaolo Bonzini } 5681c50d8ae3SPaolo Bonzini 5682c50d8ae3SPaolo Bonzini /* 5683c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5684c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5685c50d8ae3SPaolo Bonzini */ 5686c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5687c50d8ae3SPaolo Bonzini int bytes) 5688c50d8ae3SPaolo Bonzini { 5689c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5690c50d8ae3SPaolo Bonzini 5691c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5692bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5693c50d8ae3SPaolo Bonzini 5694c50d8ae3SPaolo Bonzini /* 5695c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5696c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5697c50d8ae3SPaolo Bonzini */ 5698c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5699c50d8ae3SPaolo Bonzini return false; 5700c50d8ae3SPaolo Bonzini 5701c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5702c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5703c50d8ae3SPaolo Bonzini 5704c50d8ae3SPaolo Bonzini return misaligned; 5705c50d8ae3SPaolo Bonzini } 5706c50d8ae3SPaolo Bonzini 5707c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5708c50d8ae3SPaolo Bonzini { 5709c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5710c50d8ae3SPaolo Bonzini u64 *spte; 5711c50d8ae3SPaolo Bonzini int level; 5712c50d8ae3SPaolo Bonzini 5713c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5714c50d8ae3SPaolo Bonzini level = sp->role.level; 5715c50d8ae3SPaolo Bonzini *nspte = 1; 5716bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5717c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5718c50d8ae3SPaolo Bonzini /* 5719c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5720c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5721c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5722c50d8ae3SPaolo Bonzini */ 5723c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5724c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5725c50d8ae3SPaolo Bonzini page_offset <<= 1; 5726c50d8ae3SPaolo Bonzini *nspte = 2; 5727c50d8ae3SPaolo Bonzini } 5728c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5729c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5730c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5731c50d8ae3SPaolo Bonzini return NULL; 5732c50d8ae3SPaolo Bonzini } 5733c50d8ae3SPaolo Bonzini 5734c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5735c50d8ae3SPaolo Bonzini return spte; 5736c50d8ae3SPaolo Bonzini } 5737c50d8ae3SPaolo Bonzini 573893284446SSean Christopherson void kvm_mmu_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, 573993284446SSean Christopherson int bytes) 5740c50d8ae3SPaolo Bonzini { 5741c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5742c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5743c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5744c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5745c50d8ae3SPaolo Bonzini int npte; 574606152b2dSLai Jiangshan bool flush = false; 5747c50d8ae3SPaolo Bonzini 5748c50d8ae3SPaolo Bonzini /* 5749c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5750c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5751c50d8ae3SPaolo Bonzini */ 5752c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5753c50d8ae3SPaolo Bonzini return; 5754c50d8ae3SPaolo Bonzini 5755531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5756c50d8ae3SPaolo Bonzini 5757c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5758c50d8ae3SPaolo Bonzini 5759c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5760c50d8ae3SPaolo Bonzini 5761767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5762c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5763c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5764c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5765c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5766c50d8ae3SPaolo Bonzini continue; 5767c50d8ae3SPaolo Bonzini } 5768c50d8ae3SPaolo Bonzini 5769c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5770c50d8ae3SPaolo Bonzini if (!spte) 5771c50d8ae3SPaolo Bonzini continue; 5772c50d8ae3SPaolo Bonzini 5773c50d8ae3SPaolo Bonzini while (npte--) { 5774c50d8ae3SPaolo Bonzini entry = *spte; 57752de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5776c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5777c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 57781441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 577906152b2dSLai Jiangshan flush = true; 5780c50d8ae3SPaolo Bonzini ++spte; 5781c50d8ae3SPaolo Bonzini } 5782c50d8ae3SPaolo Bonzini } 578306152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5784531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5785c50d8ae3SPaolo Bonzini } 5786c50d8ae3SPaolo Bonzini 57871075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5788c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5789c50d8ae3SPaolo Bonzini { 579092daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5791347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5792c50d8ae3SPaolo Bonzini 5793d09f7112SSean Christopherson /* 5794d09f7112SSean Christopherson * IMPLICIT_ACCESS is a KVM-defined flag used to correctly perform SMAP 5795d09f7112SSean Christopherson * checks when emulating instructions that triggers implicit access. 5796d09f7112SSean Christopherson * WARN if hardware generates a fault with an error code that collides 5797d09f7112SSean Christopherson * with the KVM-defined value. Clear the flag and continue on, i.e. 5798d09f7112SSean Christopherson * don't terminate the VM, as KVM can't possibly be relying on a flag 5799d09f7112SSean Christopherson * that KVM doesn't know about. 5800d09f7112SSean Christopherson */ 5801d09f7112SSean Christopherson if (WARN_ON_ONCE(error_code & PFERR_IMPLICIT_ACCESS)) 5802d09f7112SSean Christopherson error_code &= ~PFERR_IMPLICIT_ACCESS; 5803d09f7112SSean Christopherson 580420ba462dSSean Christopherson if (WARN_ON_ONCE(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5805ddce6208SSean Christopherson return RET_PF_RETRY; 5806ddce6208SSean Christopherson 5807c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5808c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5809736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5810c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5811c50d8ae3SPaolo Bonzini goto emulate; 5812c50d8ae3SPaolo Bonzini } 5813c50d8ae3SPaolo Bonzini 5814c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 58157a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 5816258d985fSSean Christopherson lower_32_bits(error_code), false, 5817258d985fSSean Christopherson &emulation_type); 581819025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 58197b367bc9SSean Christopherson return -EIO; 5820c50d8ae3SPaolo Bonzini } 5821c50d8ae3SPaolo Bonzini 5822c50d8ae3SPaolo Bonzini if (r < 0) 5823c50d8ae3SPaolo Bonzini return r; 582483a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 582583a2ba4cSSean Christopherson return 1; 5826c50d8ae3SPaolo Bonzini 5827c50d8ae3SPaolo Bonzini /* 5828c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5829c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5830c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5831c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5832c50d8ae3SPaolo Bonzini * and resume the guest. 5833c50d8ae3SPaolo Bonzini */ 5834347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5835c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5836736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5837c50d8ae3SPaolo Bonzini return 1; 5838c50d8ae3SPaolo Bonzini } 5839c50d8ae3SPaolo Bonzini 5840c50d8ae3SPaolo Bonzini /* 5841c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5842c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5843c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5844c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5845c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5846c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5847c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5848c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5849c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5850c50d8ae3SPaolo Bonzini */ 5851736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 585292daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5853c50d8ae3SPaolo Bonzini emulate: 5854736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5855c50d8ae3SPaolo Bonzini insn_len); 5856c50d8ae3SPaolo Bonzini } 5857c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5858c50d8ae3SPaolo Bonzini 58599fd4a4e3SLai Jiangshan static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 58609fd4a4e3SLai Jiangshan u64 addr, hpa_t root_hpa) 58619fd4a4e3SLai Jiangshan { 58629fd4a4e3SLai Jiangshan struct kvm_shadow_walk_iterator iterator; 58639fd4a4e3SLai Jiangshan 58649fd4a4e3SLai Jiangshan vcpu_clear_mmio_info(vcpu, addr); 58659fd4a4e3SLai Jiangshan 5866762b33ebSLike Xu /* 5867762b33ebSLike Xu * Walking and synchronizing SPTEs both assume they are operating in 5868762b33ebSLike Xu * the context of the current MMU, and would need to be reworked if 5869762b33ebSLike Xu * this is ever used to sync the guest_mmu, e.g. to emulate INVEPT. 5870762b33ebSLike Xu */ 5871762b33ebSLike Xu if (WARN_ON_ONCE(mmu != vcpu->arch.mmu)) 5872762b33ebSLike Xu return; 5873762b33ebSLike Xu 58749fd4a4e3SLai Jiangshan if (!VALID_PAGE(root_hpa)) 58759fd4a4e3SLai Jiangshan return; 58769fd4a4e3SLai Jiangshan 58779fd4a4e3SLai Jiangshan write_lock(&vcpu->kvm->mmu_lock); 58789fd4a4e3SLai Jiangshan for_each_shadow_entry_using_root(vcpu, root_hpa, addr, iterator) { 58799fd4a4e3SLai Jiangshan struct kvm_mmu_page *sp = sptep_to_sp(iterator.sptep); 58809fd4a4e3SLai Jiangshan 58819fd4a4e3SLai Jiangshan if (sp->unsync) { 588219ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, iterator.index); 58839fd4a4e3SLai Jiangshan 58849fd4a4e3SLai Jiangshan if (ret < 0) 58859fd4a4e3SLai Jiangshan mmu_page_zap_pte(vcpu->kvm, sp, iterator.sptep, NULL); 58869fd4a4e3SLai Jiangshan if (ret) 58879fd4a4e3SLai Jiangshan kvm_flush_remote_tlbs_sptep(vcpu->kvm, iterator.sptep); 58889fd4a4e3SLai Jiangshan } 58899fd4a4e3SLai Jiangshan 58909fd4a4e3SLai Jiangshan if (!sp->unsync_children) 58919fd4a4e3SLai Jiangshan break; 58929fd4a4e3SLai Jiangshan } 58939fd4a4e3SLai Jiangshan write_unlock(&vcpu->kvm->mmu_lock); 58949fd4a4e3SLai Jiangshan } 58959fd4a4e3SLai Jiangshan 5896753b43c9SLai Jiangshan void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 5897cd42853eSLai Jiangshan u64 addr, unsigned long roots) 5898c50d8ae3SPaolo Bonzini { 5899c50d8ae3SPaolo Bonzini int i; 5900c50d8ae3SPaolo Bonzini 5901cd42853eSLai Jiangshan WARN_ON_ONCE(roots & ~KVM_MMU_ROOTS_ALL); 5902cd42853eSLai Jiangshan 59035efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 59045efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 59055efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5906753b43c9SLai Jiangshan if (is_noncanonical_address(addr, vcpu)) 5907c50d8ae3SPaolo Bonzini return; 5908c50d8ae3SPaolo Bonzini 5909753b43c9SLai Jiangshan static_call(kvm_x86_flush_tlb_gva)(vcpu, addr); 59105efac074SPaolo Bonzini } 59115efac074SPaolo Bonzini 59129fd4a4e3SLai Jiangshan if (!mmu->sync_spte) 59135efac074SPaolo Bonzini return; 59145efac074SPaolo Bonzini 5915cd42853eSLai Jiangshan if (roots & KVM_MMU_ROOT_CURRENT) 59169fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->root.hpa); 5917c50d8ae3SPaolo Bonzini 5918cd42853eSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5919ed335278SLai Jiangshan if (roots & KVM_MMU_ROOT_PREVIOUS(i)) 59209fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->prev_roots[i].hpa); 59215efac074SPaolo Bonzini } 59225efac074SPaolo Bonzini } 59232c86c444SLai Jiangshan EXPORT_SYMBOL_GPL(kvm_mmu_invalidate_addr); 5924c50d8ae3SPaolo Bonzini 59255efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 59265efac074SPaolo Bonzini { 5927cd42853eSLai Jiangshan /* 5928cd42853eSLai Jiangshan * INVLPG is required to invalidate any global mappings for the VA, 5929cd42853eSLai Jiangshan * irrespective of PCID. Blindly sync all roots as it would take 5930cd42853eSLai Jiangshan * roughly the same amount of work/time to determine whether any of the 5931cd42853eSLai Jiangshan * previous roots have a global mapping. 5932cd42853eSLai Jiangshan * 5933cd42853eSLai Jiangshan * Mappings not reachable via the current or previous cached roots will 5934cd42853eSLai Jiangshan * be synced when switching to that new cr3, so nothing needs to be 5935cd42853eSLai Jiangshan * done here for them. 5936cd42853eSLai Jiangshan */ 5937cd42853eSLai Jiangshan kvm_mmu_invalidate_addr(vcpu, vcpu->arch.walk_mmu, gva, KVM_MMU_ROOTS_ALL); 5938c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5939c50d8ae3SPaolo Bonzini } 5940c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5941c50d8ae3SPaolo Bonzini 59425efac074SPaolo Bonzini 5943c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5944c50d8ae3SPaolo Bonzini { 5945c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 59469ebc3f51SLai Jiangshan unsigned long roots = 0; 5947c50d8ae3SPaolo Bonzini uint i; 5948c50d8ae3SPaolo Bonzini 59499ebc3f51SLai Jiangshan if (pcid == kvm_get_active_pcid(vcpu)) 59509ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_CURRENT; 5951c50d8ae3SPaolo Bonzini 5952c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5953c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 59549ebc3f51SLai Jiangshan pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) 59559ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_PREVIOUS(i); 5956c50d8ae3SPaolo Bonzini } 5957c50d8ae3SPaolo Bonzini 59589ebc3f51SLai Jiangshan if (roots) 59599ebc3f51SLai Jiangshan kvm_mmu_invalidate_addr(vcpu, mmu, gva, roots); 5960c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5961c50d8ae3SPaolo Bonzini 5962c50d8ae3SPaolo Bonzini /* 5963c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5964c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5965c50d8ae3SPaolo Bonzini * for them. 5966c50d8ae3SPaolo Bonzini */ 5967c50d8ae3SPaolo Bonzini } 5968c50d8ae3SPaolo Bonzini 5969746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5970746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5971c50d8ae3SPaolo Bonzini { 5972bde77235SSean Christopherson tdp_enabled = enable_tdp; 5973746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 597483013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5975703c335dSSean Christopherson 59761f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 59771f98f2bdSDavid Matlack tdp_mmu_enabled = tdp_mmu_allowed && tdp_enabled; 59781f98f2bdSDavid Matlack #endif 5979703c335dSSean Christopherson /* 59801d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5981703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5982703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5983703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5984703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5985703c335dSSean Christopherson */ 5986703c335dSSean Christopherson if (tdp_enabled) 59871d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5988703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 59891d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5990703c335dSSean Christopherson else 59911d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5992c50d8ae3SPaolo Bonzini } 5993bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5994c50d8ae3SPaolo Bonzini 5995c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5996727ae377SSean Christopherson typedef bool (*slot_rmaps_handler) (struct kvm *kvm, 5997269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5998269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5999c50d8ae3SPaolo Bonzini 6000727ae377SSean Christopherson static __always_inline bool __walk_slot_rmaps(struct kvm *kvm, 6001727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6002727ae377SSean Christopherson slot_rmaps_handler fn, 6003727ae377SSean Christopherson int start_level, int end_level, 6004727ae377SSean Christopherson gfn_t start_gfn, gfn_t end_gfn, 6005727ae377SSean Christopherson bool flush_on_yield, bool flush) 6006c50d8ae3SPaolo Bonzini { 6007c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 6008c50d8ae3SPaolo Bonzini 6009eddd9e83SSean Christopherson lockdep_assert_held_write(&kvm->mmu_lock); 6010eddd9e83SSean Christopherson 6011727ae377SSean Christopherson for_each_slot_rmap_range(slot, start_level, end_level, start_gfn, 6012c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 6013c50d8ae3SPaolo Bonzini if (iterator.rmap) 6014727ae377SSean Christopherson flush |= fn(kvm, iterator.rmap, slot); 6015c50d8ae3SPaolo Bonzini 6016531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6017302695a5SSean Christopherson if (flush && flush_on_yield) { 60188c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, start_gfn, 6019c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 6020c50d8ae3SPaolo Bonzini flush = false; 6021c50d8ae3SPaolo Bonzini } 6022531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6023c50d8ae3SPaolo Bonzini } 6024c50d8ae3SPaolo Bonzini } 6025c50d8ae3SPaolo Bonzini 6026c50d8ae3SPaolo Bonzini return flush; 6027c50d8ae3SPaolo Bonzini } 6028c50d8ae3SPaolo Bonzini 6029727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps(struct kvm *kvm, 6030727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6031727ae377SSean Christopherson slot_rmaps_handler fn, 6032727ae377SSean Christopherson int start_level, int end_level, 6033302695a5SSean Christopherson bool flush_on_yield) 6034c50d8ae3SPaolo Bonzini { 6035727ae377SSean Christopherson return __walk_slot_rmaps(kvm, slot, fn, start_level, end_level, 6036727ae377SSean Christopherson slot->base_gfn, slot->base_gfn + slot->npages - 1, 60371a61b7dbSSean Christopherson flush_on_yield, false); 6038c50d8ae3SPaolo Bonzini } 6039c50d8ae3SPaolo Bonzini 6040727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps_4k(struct kvm *kvm, 6041727ae377SSean Christopherson const struct kvm_memory_slot *slot, 6042727ae377SSean Christopherson slot_rmaps_handler fn, 6043727ae377SSean Christopherson bool flush_on_yield) 6044c50d8ae3SPaolo Bonzini { 6045727ae377SSean Christopherson return walk_slot_rmaps(kvm, slot, fn, PG_LEVEL_4K, PG_LEVEL_4K, flush_on_yield); 6046c50d8ae3SPaolo Bonzini } 6047c50d8ae3SPaolo Bonzini 6048c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 6049c50d8ae3SPaolo Bonzini { 60504a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 60514a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 6052c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 605303ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 6054cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 6055c50d8ae3SPaolo Bonzini } 6056c50d8ae3SPaolo Bonzini 605704d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 6058c50d8ae3SPaolo Bonzini { 6059c50d8ae3SPaolo Bonzini struct page *page; 6060c50d8ae3SPaolo Bonzini int i; 6061c50d8ae3SPaolo Bonzini 6062b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 6063b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 606404d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 606504d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 606604d28e37SSean Christopherson 606727f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 606827f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 606927f4fca2SLai Jiangshan return 0; 607027f4fca2SLai Jiangshan 6071c50d8ae3SPaolo Bonzini /* 6072c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 6073c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 6074c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 6075c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 607604d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 607704d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 607804d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 607904d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 608084432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 6081c50d8ae3SPaolo Bonzini */ 6082d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 6083c50d8ae3SPaolo Bonzini return 0; 6084c50d8ae3SPaolo Bonzini 6085c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 6086c50d8ae3SPaolo Bonzini if (!page) 6087c50d8ae3SPaolo Bonzini return -ENOMEM; 6088c50d8ae3SPaolo Bonzini 6089c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 60904a98623dSSean Christopherson 60914a98623dSSean Christopherson /* 60924a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 60934a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 60944a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 60954a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 60964a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 60974a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 60984a98623dSSean Christopherson */ 60994a98623dSSean Christopherson if (!tdp_enabled) 61004a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 61014a98623dSSean Christopherson else 6102e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 61034a98623dSSean Christopherson 6104c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 6105c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 6106c50d8ae3SPaolo Bonzini 6107c50d8ae3SPaolo Bonzini return 0; 6108c50d8ae3SPaolo Bonzini } 6109c50d8ae3SPaolo Bonzini 6110c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 6111c50d8ae3SPaolo Bonzini { 6112c50d8ae3SPaolo Bonzini int ret; 6113c50d8ae3SPaolo Bonzini 61145962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 61155f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 61165f6078f9SSean Christopherson 61175962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 61185f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 61195962bfb7SSean Christopherson 612096880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 612196880883SSean Christopherson 6122c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 6123c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 6124c50d8ae3SPaolo Bonzini 612504d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 6126c50d8ae3SPaolo Bonzini if (ret) 6127c50d8ae3SPaolo Bonzini return ret; 6128c50d8ae3SPaolo Bonzini 612904d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 6130c50d8ae3SPaolo Bonzini if (ret) 6131c50d8ae3SPaolo Bonzini goto fail_allocate_root; 6132c50d8ae3SPaolo Bonzini 6133c50d8ae3SPaolo Bonzini return ret; 6134c50d8ae3SPaolo Bonzini fail_allocate_root: 6135c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6136c50d8ae3SPaolo Bonzini return ret; 6137c50d8ae3SPaolo Bonzini } 6138c50d8ae3SPaolo Bonzini 6139c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 6140c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 6141c50d8ae3SPaolo Bonzini { 6142c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6143c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 6144b28cb0cdSSean Christopherson bool unstable; 6145c50d8ae3SPaolo Bonzini 6146c50d8ae3SPaolo Bonzini restart: 6147c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 6148c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 6149c50d8ae3SPaolo Bonzini /* 6150c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 6151c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 6152c50d8ae3SPaolo Bonzini */ 6153c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 6154c50d8ae3SPaolo Bonzini break; 6155c50d8ae3SPaolo Bonzini 6156c50d8ae3SPaolo Bonzini /* 6157f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 6158f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 6159f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 6160c50d8ae3SPaolo Bonzini */ 616120ba462dSSean Christopherson if (WARN_ON_ONCE(sp->role.invalid)) 6162c50d8ae3SPaolo Bonzini continue; 6163c50d8ae3SPaolo Bonzini 6164c50d8ae3SPaolo Bonzini /* 6165c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 6166c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 6167c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 6168c50d8ae3SPaolo Bonzini * be in active use by the guest. 6169c50d8ae3SPaolo Bonzini */ 6170c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 6171531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 6172c50d8ae3SPaolo Bonzini batch = 0; 6173c50d8ae3SPaolo Bonzini goto restart; 6174c50d8ae3SPaolo Bonzini } 6175c50d8ae3SPaolo Bonzini 6176b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 6177b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 6178c50d8ae3SPaolo Bonzini batch += nr_zapped; 6179b28cb0cdSSean Christopherson 6180b28cb0cdSSean Christopherson if (unstable) 6181c50d8ae3SPaolo Bonzini goto restart; 6182c50d8ae3SPaolo Bonzini } 6183c50d8ae3SPaolo Bonzini 6184c50d8ae3SPaolo Bonzini /* 61857ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 61867ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 61877ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 61887ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 61897ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 61907ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 61917ae5840eSSean Christopherson * running with an obsolete MMU. 6192c50d8ae3SPaolo Bonzini */ 6193c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 6194c50d8ae3SPaolo Bonzini } 6195c50d8ae3SPaolo Bonzini 6196c50d8ae3SPaolo Bonzini /* 6197c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 6198c50d8ae3SPaolo Bonzini * to zap obsolete pages. 6199c50d8ae3SPaolo Bonzini * 6200c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 6201c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 6202c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 6203c50d8ae3SPaolo Bonzini * after calling the function. 6204c50d8ae3SPaolo Bonzini */ 6205c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 6206c50d8ae3SPaolo Bonzini { 6207c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 6208c50d8ae3SPaolo Bonzini 6209531810caSBen Gardon write_lock(&kvm->mmu_lock); 6210c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 6211c50d8ae3SPaolo Bonzini 6212c50d8ae3SPaolo Bonzini /* 6213c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 6214c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 6215c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 6216c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 6217c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 6218c50d8ae3SPaolo Bonzini */ 6219c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 6220c50d8ae3SPaolo Bonzini 62212f6f66ccSSean Christopherson /* 62222f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 62232f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 62242f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 62252f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 6226b7cccd39SBen Gardon */ 62271f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6228b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 6229b7cccd39SBen Gardon 6230c50d8ae3SPaolo Bonzini /* 6231c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 6232c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 6233c50d8ae3SPaolo Bonzini * mmu_valid_gen. 6234c50d8ae3SPaolo Bonzini * 6235c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 6236c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 6237c50d8ae3SPaolo Bonzini */ 6238527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 6239c50d8ae3SPaolo Bonzini 6240c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 6241faaf05b0SBen Gardon 6242531810caSBen Gardon write_unlock(&kvm->mmu_lock); 62434c6654bdSBen Gardon 6244f28e9c7fSSean Christopherson /* 6245f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 6246f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 6247f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 6248f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 6249f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 6250f28e9c7fSSean Christopherson * lead to use-after-free. 6251f28e9c7fSSean Christopherson */ 62521f98f2bdSDavid Matlack if (tdp_mmu_enabled) 62534c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 6254c50d8ae3SPaolo Bonzini } 6255c50d8ae3SPaolo Bonzini 6256c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 6257c50d8ae3SPaolo Bonzini { 6258c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 6259c50d8ae3SPaolo Bonzini } 6260c50d8ae3SPaolo Bonzini 62610df9dab8SSean Christopherson void kvm_mmu_init_vm(struct kvm *kvm) 6262c50d8ae3SPaolo Bonzini { 6263a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 6264a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 626555c510e2SSean Christopherson INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages); 6266ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 6267ce25681dSSean Christopherson 62680df9dab8SSean Christopherson if (tdp_mmu_enabled) 62690df9dab8SSean Christopherson kvm_mmu_init_tdp_mmu(kvm); 6270fe5db27dSBen Gardon 6271ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 6272ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 6273ada51a9dSDavid Matlack 6274ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 6275ada51a9dSDavid Matlack 6276ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 6277ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 6278c50d8ae3SPaolo Bonzini } 6279c50d8ae3SPaolo Bonzini 6280ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 6281ada51a9dSDavid Matlack { 6282ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 6283ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6284ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6285ada51a9dSDavid Matlack } 6286ada51a9dSDavid Matlack 6287c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6288c50d8ae3SPaolo Bonzini { 628909732d2bSDavid Matlack if (tdp_mmu_enabled) 6290fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6291ada51a9dSDavid Matlack 6292ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6293c50d8ae3SPaolo Bonzini } 6294c50d8ae3SPaolo Bonzini 62952833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 629621fa3246SSean Christopherson { 629721fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 629821fa3246SSean Christopherson struct kvm_memslots *slots; 6299f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 630021fa3246SSean Christopherson bool flush = false; 630121fa3246SSean Christopherson gfn_t start, end; 6302f4209439SMaciej S. Szmigiero int i; 630321fa3246SSean Christopherson 630421fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 630521fa3246SSean Christopherson return flush; 630621fa3246SSean Christopherson 6307eed52e43SSean Christopherson for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { 630821fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6309f4209439SMaciej S. Szmigiero 6310f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6311f4209439SMaciej S. Szmigiero memslot = iter.slot; 631221fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 631321fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6314f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 631521fa3246SSean Christopherson continue; 631621fa3246SSean Christopherson 6317727ae377SSean Christopherson flush = __walk_slot_rmaps(kvm, memslot, __kvm_zap_rmap, 631821fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 631921fa3246SSean Christopherson start, end - 1, true, flush); 632021fa3246SSean Christopherson } 632121fa3246SSean Christopherson } 632221fa3246SSean Christopherson 632321fa3246SSean Christopherson return flush; 632421fa3246SSean Christopherson } 632521fa3246SSean Christopherson 632688f58535SMaxim Levitsky /* 632788f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 632888f58535SMaxim Levitsky * (not including it) 632988f58535SMaxim Levitsky */ 6330c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6331c50d8ae3SPaolo Bonzini { 633221fa3246SSean Christopherson bool flush; 6333c50d8ae3SPaolo Bonzini 6334f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6335f4209439SMaciej S. Szmigiero return; 6336f4209439SMaciej S. Szmigiero 6337531810caSBen Gardon write_lock(&kvm->mmu_lock); 63385a324c24SSean Christopherson 63398569992dSChao Peng kvm_mmu_invalidate_begin(kvm); 63408569992dSChao Peng 63418569992dSChao Peng kvm_mmu_invalidate_range_add(kvm, gfn_start, gfn_end); 6342edb298c6SMaxim Levitsky 63432833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 63446103bc07SBen Gardon 6345441a5dfcSPaolo Bonzini if (tdp_mmu_enabled) 6346441a5dfcSPaolo Bonzini flush = kvm_tdp_mmu_zap_leafs(kvm, gfn_start, gfn_end, flush); 63475a324c24SSean Christopherson 63485a324c24SSean Christopherson if (flush) 63498c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, gfn_start, gfn_end - gfn_start); 63505a324c24SSean Christopherson 63518569992dSChao Peng kvm_mmu_invalidate_end(kvm); 6352edb298c6SMaxim Levitsky 63535a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6354c50d8ae3SPaolo Bonzini } 6355c50d8ae3SPaolo Bonzini 6356c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 63570a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6358269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6359c50d8ae3SPaolo Bonzini { 63601346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6361c50d8ae3SPaolo Bonzini } 6362c50d8ae3SPaolo Bonzini 6363c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6364269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 63653c9bd400SJay Zhou int start_level) 6366c50d8ae3SPaolo Bonzini { 6367e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6368531810caSBen Gardon write_lock(&kvm->mmu_lock); 6369727ae377SSean Christopherson walk_slot_rmaps(kvm, memslot, slot_rmap_write_protect, 6370b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6371531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6372e2209710SBen Gardon } 6373c50d8ae3SPaolo Bonzini 63741f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 637524ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6376b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 637724ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 637824ae4cfaSBen Gardon } 6379c50d8ae3SPaolo Bonzini } 6380c50d8ae3SPaolo Bonzini 6381ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6382ada51a9dSDavid Matlack { 6383ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6384ada51a9dSDavid Matlack } 6385ada51a9dSDavid Matlack 6386ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6387ada51a9dSDavid Matlack { 6388ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6389ada51a9dSDavid Matlack return true; 6390ada51a9dSDavid Matlack 6391ada51a9dSDavid Matlack /* 6392ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6393ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6394ada51a9dSDavid Matlack * is possible but not worth the complexity. 6395ada51a9dSDavid Matlack */ 6396ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6397ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6398ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6399ada51a9dSDavid Matlack } 6400ada51a9dSDavid Matlack 6401ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6402ada51a9dSDavid Matlack { 6403b9b71f43SSean Christopherson /* 6404b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6405dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6406b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6407dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6408dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6409dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6410dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6411dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6412dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6413dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6414b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6415b9b71f43SSean Christopherson */ 6416b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6417b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6418ada51a9dSDavid Matlack int r; 6419ada51a9dSDavid Matlack 6420ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6421ada51a9dSDavid Matlack 6422b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6423ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6424ada51a9dSDavid Matlack if (r) 6425ada51a9dSDavid Matlack return r; 6426ada51a9dSDavid Matlack 6427ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6428ada51a9dSDavid Matlack if (r) 6429ada51a9dSDavid Matlack return r; 6430ada51a9dSDavid Matlack 6431ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6432ada51a9dSDavid Matlack } 6433ada51a9dSDavid Matlack 6434ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6435ada51a9dSDavid Matlack { 6436ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6437ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6438ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6439ada51a9dSDavid Matlack unsigned int access; 6440ada51a9dSDavid Matlack gfn_t gfn; 6441ada51a9dSDavid Matlack 644279e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 644379e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6444ada51a9dSDavid Matlack 6445ada51a9dSDavid Matlack /* 6446ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6447ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6448ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6449ada51a9dSDavid Matlack * mapped with smaller pages. 6450ada51a9dSDavid Matlack */ 6451ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6452ada51a9dSDavid Matlack 6453ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6454ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6455ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6456ada51a9dSDavid Matlack 6457ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6458ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6459ada51a9dSDavid Matlack } 6460ada51a9dSDavid Matlack 6461ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6462ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6463ada51a9dSDavid Matlack u64 *huge_sptep) 6464ada51a9dSDavid Matlack 6465ada51a9dSDavid Matlack { 6466ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6467ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6468ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 646903787394SPaolo Bonzini bool flush = false; 6470ada51a9dSDavid Matlack u64 *sptep, spte; 6471ada51a9dSDavid Matlack gfn_t gfn; 6472ada51a9dSDavid Matlack int index; 6473ada51a9dSDavid Matlack 6474ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6475ada51a9dSDavid Matlack 6476ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6477ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6478ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6479ada51a9dSDavid Matlack 6480ada51a9dSDavid Matlack /* 6481ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6482ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6483ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6484ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6485ada51a9dSDavid Matlack * modify them. 6486ada51a9dSDavid Matlack * 648703787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 648803787394SPaolo Bonzini * that lower level page table may only be partially populated. 648903787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 649003787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 649103787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 649203787394SPaolo Bonzini * fail to detect the need to flush. 6493ada51a9dSDavid Matlack */ 649403787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 649503787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6496ada51a9dSDavid Matlack continue; 649703787394SPaolo Bonzini } 6498ada51a9dSDavid Matlack 6499ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6500ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6501ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6502ada51a9dSDavid Matlack } 6503ada51a9dSDavid Matlack 650403787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6505ada51a9dSDavid Matlack } 6506ada51a9dSDavid Matlack 6507ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6508ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6509ada51a9dSDavid Matlack u64 *huge_sptep) 6510ada51a9dSDavid Matlack { 6511ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6512ada51a9dSDavid Matlack int level, r = 0; 6513ada51a9dSDavid Matlack gfn_t gfn; 6514ada51a9dSDavid Matlack u64 spte; 6515ada51a9dSDavid Matlack 6516ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 651779e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6518ada51a9dSDavid Matlack level = huge_sp->role.level; 6519ada51a9dSDavid Matlack spte = *huge_sptep; 6520ada51a9dSDavid Matlack 6521ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6522ada51a9dSDavid Matlack r = -ENOSPC; 6523ada51a9dSDavid Matlack goto out; 6524ada51a9dSDavid Matlack } 6525ada51a9dSDavid Matlack 6526ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6527ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6528ada51a9dSDavid Matlack cond_resched(); 6529ada51a9dSDavid Matlack /* 6530ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6531ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6532ada51a9dSDavid Matlack * dropped. 6533ada51a9dSDavid Matlack */ 6534ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6535ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6536ada51a9dSDavid Matlack goto out; 6537ada51a9dSDavid Matlack } 6538ada51a9dSDavid Matlack 6539ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6540ada51a9dSDavid Matlack 6541ada51a9dSDavid Matlack out: 6542ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6543ada51a9dSDavid Matlack return r; 6544ada51a9dSDavid Matlack } 6545ada51a9dSDavid Matlack 6546ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6547ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6548ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6549ada51a9dSDavid Matlack { 6550ada51a9dSDavid Matlack struct rmap_iterator iter; 6551ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6552ada51a9dSDavid Matlack u64 *huge_sptep; 6553ada51a9dSDavid Matlack int r; 6554ada51a9dSDavid Matlack 6555ada51a9dSDavid Matlack restart: 6556ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6557ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6558ada51a9dSDavid Matlack 6559ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6560ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6561ada51a9dSDavid Matlack continue; 6562ada51a9dSDavid Matlack 6563ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6564ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6565ada51a9dSDavid Matlack continue; 6566ada51a9dSDavid Matlack 6567ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6568ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6569ada51a9dSDavid Matlack continue; 6570ada51a9dSDavid Matlack 6571ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6572ada51a9dSDavid Matlack if (sp->role.invalid) 6573ada51a9dSDavid Matlack continue; 6574ada51a9dSDavid Matlack 6575ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6576ada51a9dSDavid Matlack 6577ada51a9dSDavid Matlack /* 6578ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6579ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6580ada51a9dSDavid Matlack * back into a consistent state. 6581ada51a9dSDavid Matlack */ 6582ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6583ada51a9dSDavid Matlack goto restart; 6584ada51a9dSDavid Matlack 6585ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6586ada51a9dSDavid Matlack break; 6587ada51a9dSDavid Matlack } 6588ada51a9dSDavid Matlack 6589ada51a9dSDavid Matlack return false; 6590ada51a9dSDavid Matlack } 6591ada51a9dSDavid Matlack 6592ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6593ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6594ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6595ada51a9dSDavid Matlack int target_level) 6596ada51a9dSDavid Matlack { 6597ada51a9dSDavid Matlack int level; 6598ada51a9dSDavid Matlack 6599ada51a9dSDavid Matlack /* 6600ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6601ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6602ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6603ada51a9dSDavid Matlack * already at the target level. 6604ada51a9dSDavid Matlack */ 6605727ae377SSean Christopherson for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) 6606727ae377SSean Christopherson __walk_slot_rmaps(kvm, slot, shadow_mmu_try_split_huge_pages, 6607ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6608ada51a9dSDavid Matlack } 6609ada51a9dSDavid Matlack 6610cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6611cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6612cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6613cb00a70bSDavid Matlack u64 start, u64 end, 6614cb00a70bSDavid Matlack int target_level) 6615cb00a70bSDavid Matlack { 66161f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6617ada51a9dSDavid Matlack return; 6618ada51a9dSDavid Matlack 6619ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6620ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6621ada51a9dSDavid Matlack 6622ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6623cb00a70bSDavid Matlack 6624cb00a70bSDavid Matlack /* 662554aa699eSBjorn Helgaas * A TLB flush is unnecessary at this point for the same reasons as in 6626cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6627cb00a70bSDavid Matlack */ 6628cb00a70bSDavid Matlack } 6629cb00a70bSDavid Matlack 6630a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6631a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6632a3fe5dbdSDavid Matlack int target_level) 6633a3fe5dbdSDavid Matlack { 6634a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6635a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6636a3fe5dbdSDavid Matlack 66371f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6638ada51a9dSDavid Matlack return; 6639ada51a9dSDavid Matlack 6640ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6641ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6642ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6643ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6644ada51a9dSDavid Matlack } 6645ada51a9dSDavid Matlack 6646a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6647cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6648a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6649a3fe5dbdSDavid Matlack 6650a3fe5dbdSDavid Matlack /* 6651a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6652a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6653a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6654a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6655a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6656a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6657a3fe5dbdSDavid Matlack * SPTEs. 6658a3fe5dbdSDavid Matlack */ 6659a3fe5dbdSDavid Matlack } 6660a3fe5dbdSDavid Matlack 6661c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 66620a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6663269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6664c50d8ae3SPaolo Bonzini { 6665c50d8ae3SPaolo Bonzini u64 *sptep; 6666c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6667c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6668c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6669c50d8ae3SPaolo Bonzini 6670c50d8ae3SPaolo Bonzini restart: 6671c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 667257354682SSean Christopherson sp = sptep_to_sp(sptep); 6673c50d8ae3SPaolo Bonzini 6674c50d8ae3SPaolo Bonzini /* 6675c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6676c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6677c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6678c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6679c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6680c50d8ae3SPaolo Bonzini */ 66815d49f08cSSean Christopherson if (sp->role.direct && 66829eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6683a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 66849202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6685c50d8ae3SPaolo Bonzini 66868a1300ffSSean Christopherson if (kvm_available_flush_remote_tlbs_range()) 66871b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 6688c50d8ae3SPaolo Bonzini else 6689c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6690c50d8ae3SPaolo Bonzini 6691c50d8ae3SPaolo Bonzini goto restart; 6692c50d8ae3SPaolo Bonzini } 6693c50d8ae3SPaolo Bonzini } 6694c50d8ae3SPaolo Bonzini 6695c50d8ae3SPaolo Bonzini return need_tlb_flush; 6696c50d8ae3SPaolo Bonzini } 6697c50d8ae3SPaolo Bonzini 669820d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 669920d49186SDavid Matlack const struct kvm_memory_slot *slot) 670020d49186SDavid Matlack { 670120d49186SDavid Matlack /* 670220d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 670320d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 670420d49186SDavid Matlack */ 6705727ae377SSean Christopherson if (walk_slot_rmaps(kvm, slot, kvm_mmu_zap_collapsible_spte, 670620d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 6707619b5072SDavid Matlack kvm_flush_remote_tlbs_memslot(kvm, slot); 670820d49186SDavid Matlack } 670920d49186SDavid Matlack 6710c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6711269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6712c50d8ae3SPaolo Bonzini { 6713e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6714531810caSBen Gardon write_lock(&kvm->mmu_lock); 671520d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6716531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6717e2209710SBen Gardon } 67182db6f772SBen Gardon 67191f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 67202db6f772SBen Gardon read_lock(&kvm->mmu_lock); 67214b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 67222db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 67232db6f772SBen Gardon } 6724c50d8ae3SPaolo Bonzini } 6725c50d8ae3SPaolo Bonzini 6726c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6727269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6728c50d8ae3SPaolo Bonzini { 6729e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6730531810caSBen Gardon write_lock(&kvm->mmu_lock); 6731610265eaSDavid Matlack /* 6732610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6733610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6734610265eaSDavid Matlack */ 6735727ae377SSean Christopherson walk_slot_rmaps_4k(kvm, memslot, __rmap_clear_dirty, false); 6736531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6737e2209710SBen Gardon } 6738c50d8ae3SPaolo Bonzini 67391f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 674024ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6741b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 674224ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 674324ae4cfaSBen Gardon } 674424ae4cfaSBen Gardon 6745c50d8ae3SPaolo Bonzini /* 6746b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6747b64d740eSJunaid Shahid * 6748c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6749c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6750c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6751c50d8ae3SPaolo Bonzini * dirty_bitmap. 6752c50d8ae3SPaolo Bonzini */ 6753c50d8ae3SPaolo Bonzini } 6754c50d8ae3SPaolo Bonzini 6755db0d70e6SSean Christopherson static void kvm_mmu_zap_all(struct kvm *kvm) 6756c50d8ae3SPaolo Bonzini { 6757c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6758c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6759c50d8ae3SPaolo Bonzini int ign; 6760c50d8ae3SPaolo Bonzini 6761531810caSBen Gardon write_lock(&kvm->mmu_lock); 6762c50d8ae3SPaolo Bonzini restart: 6763c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 676420ba462dSSean Christopherson if (WARN_ON_ONCE(sp->role.invalid)) 6765c50d8ae3SPaolo Bonzini continue; 6766c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6767c50d8ae3SPaolo Bonzini goto restart; 6768531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6769c50d8ae3SPaolo Bonzini goto restart; 6770c50d8ae3SPaolo Bonzini } 6771c50d8ae3SPaolo Bonzini 6772c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6773faaf05b0SBen Gardon 67741f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6775faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6776faaf05b0SBen Gardon 6777531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6778c50d8ae3SPaolo Bonzini } 6779c50d8ae3SPaolo Bonzini 6780db0d70e6SSean Christopherson void kvm_arch_flush_shadow_all(struct kvm *kvm) 6781db0d70e6SSean Christopherson { 6782db0d70e6SSean Christopherson kvm_mmu_zap_all(kvm); 6783db0d70e6SSean Christopherson } 6784db0d70e6SSean Christopherson 6785db0d70e6SSean Christopherson void kvm_arch_flush_shadow_memslot(struct kvm *kvm, 6786db0d70e6SSean Christopherson struct kvm_memory_slot *slot) 6787db0d70e6SSean Christopherson { 6788eeb87272SSean Christopherson kvm_mmu_zap_all_fast(kvm); 6789db0d70e6SSean Christopherson } 6790db0d70e6SSean Christopherson 6791c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6792c50d8ae3SPaolo Bonzini { 679320ba462dSSean Christopherson WARN_ON_ONCE(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6794c50d8ae3SPaolo Bonzini 6795c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6796c50d8ae3SPaolo Bonzini 6797c50d8ae3SPaolo Bonzini /* 6798c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6799c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6800c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6801c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6802c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6803c50d8ae3SPaolo Bonzini */ 6804eed52e43SSean Christopherson gen &= ~((u64)kvm_arch_nr_memslot_as_ids(kvm) - 1); 6805c50d8ae3SPaolo Bonzini 6806c50d8ae3SPaolo Bonzini /* 6807c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6808c50d8ae3SPaolo Bonzini * zap all shadow pages. 6809c50d8ae3SPaolo Bonzini */ 6810c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 68118d20bd63SSean Christopherson kvm_debug_ratelimited("zapping shadow pages for mmio generation wraparound\n"); 6812c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6813c50d8ae3SPaolo Bonzini } 6814c50d8ae3SPaolo Bonzini } 6815c50d8ae3SPaolo Bonzini 6816f3d90f90SSean Christopherson static unsigned long mmu_shrink_scan(struct shrinker *shrink, 6817f3d90f90SSean Christopherson struct shrink_control *sc) 6818c50d8ae3SPaolo Bonzini { 6819c50d8ae3SPaolo Bonzini struct kvm *kvm; 6820c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6821c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6822c50d8ae3SPaolo Bonzini 6823c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6824c50d8ae3SPaolo Bonzini 6825c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6826c50d8ae3SPaolo Bonzini int idx; 6827c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6828c50d8ae3SPaolo Bonzini 6829c50d8ae3SPaolo Bonzini /* 6830c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6831c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6832c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6833c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6834c50d8ae3SPaolo Bonzini */ 6835c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6836c50d8ae3SPaolo Bonzini break; 6837c50d8ae3SPaolo Bonzini /* 6838c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6839c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6840c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6841c50d8ae3SPaolo Bonzini * anyway. 6842c50d8ae3SPaolo Bonzini */ 6843c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6844c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6845c50d8ae3SPaolo Bonzini continue; 6846c50d8ae3SPaolo Bonzini 6847c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6848531810caSBen Gardon write_lock(&kvm->mmu_lock); 6849c50d8ae3SPaolo Bonzini 6850c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6851c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6852c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6853c50d8ae3SPaolo Bonzini goto unlock; 6854c50d8ae3SPaolo Bonzini } 6855c50d8ae3SPaolo Bonzini 6856ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6857c50d8ae3SPaolo Bonzini 6858c50d8ae3SPaolo Bonzini unlock: 6859531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6860c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6861c50d8ae3SPaolo Bonzini 6862c50d8ae3SPaolo Bonzini /* 6863c50d8ae3SPaolo Bonzini * unfair on small ones 6864c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6865c50d8ae3SPaolo Bonzini * sadness comes quickly 6866c50d8ae3SPaolo Bonzini */ 6867c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6868c50d8ae3SPaolo Bonzini break; 6869c50d8ae3SPaolo Bonzini } 6870c50d8ae3SPaolo Bonzini 6871c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6872c50d8ae3SPaolo Bonzini return freed; 6873c50d8ae3SPaolo Bonzini } 6874c50d8ae3SPaolo Bonzini 6875f3d90f90SSean Christopherson static unsigned long mmu_shrink_count(struct shrinker *shrink, 6876f3d90f90SSean Christopherson struct shrink_control *sc) 6877c50d8ae3SPaolo Bonzini { 6878c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6879c50d8ae3SPaolo Bonzini } 6880c50d8ae3SPaolo Bonzini 6881e5985c40SQi Zheng static struct shrinker *mmu_shrinker; 6882c50d8ae3SPaolo Bonzini 6883c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6884c50d8ae3SPaolo Bonzini { 6885c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6886c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6887c50d8ae3SPaolo Bonzini } 6888c50d8ae3SPaolo Bonzini 68890b210fafSSean Christopherson static int get_nx_huge_pages(char *buffer, const struct kernel_param *kp) 68900b210fafSSean Christopherson { 68910b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 68921d6664faSLike Xu return sysfs_emit(buffer, "never\n"); 68930b210fafSSean Christopherson 68940b210fafSSean Christopherson return param_get_bool(buffer, kp); 68950b210fafSSean Christopherson } 68960b210fafSSean Christopherson 6897c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6898c50d8ae3SPaolo Bonzini { 6899c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6900c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6901c50d8ae3SPaolo Bonzini } 6902c50d8ae3SPaolo Bonzini 6903c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6904c50d8ae3SPaolo Bonzini { 6905c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6906c50d8ae3SPaolo Bonzini } 6907c50d8ae3SPaolo Bonzini 6908c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6909c50d8ae3SPaolo Bonzini { 6910c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6911c50d8ae3SPaolo Bonzini bool new_val; 6912c50d8ae3SPaolo Bonzini 69130b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 69140b210fafSSean Christopherson return -EPERM; 69150b210fafSSean Christopherson 6916c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 69170b210fafSSean Christopherson if (sysfs_streq(val, "off")) { 6918c50d8ae3SPaolo Bonzini new_val = 0; 69190b210fafSSean Christopherson } else if (sysfs_streq(val, "force")) { 6920c50d8ae3SPaolo Bonzini new_val = 1; 69210b210fafSSean Christopherson } else if (sysfs_streq(val, "auto")) { 6922c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 69230b210fafSSean Christopherson } else if (sysfs_streq(val, "never")) { 69240b210fafSSean Christopherson new_val = 0; 69250b210fafSSean Christopherson 69260b210fafSSean Christopherson mutex_lock(&kvm_lock); 69270b210fafSSean Christopherson if (!list_empty(&vm_list)) { 69280b210fafSSean Christopherson mutex_unlock(&kvm_lock); 69290b210fafSSean Christopherson return -EBUSY; 69300b210fafSSean Christopherson } 69310b210fafSSean Christopherson nx_hugepage_mitigation_hard_disabled = true; 69320b210fafSSean Christopherson mutex_unlock(&kvm_lock); 69330b210fafSSean Christopherson } else if (kstrtobool(val, &new_val) < 0) { 6934c50d8ae3SPaolo Bonzini return -EINVAL; 69350b210fafSSean Christopherson } 6936c50d8ae3SPaolo Bonzini 6937c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6938c50d8ae3SPaolo Bonzini 6939c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6940c50d8ae3SPaolo Bonzini struct kvm *kvm; 6941c50d8ae3SPaolo Bonzini 6942c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6943c50d8ae3SPaolo Bonzini 6944c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6945c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6946c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6947c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6948c50d8ae3SPaolo Bonzini 694955c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 6950c50d8ae3SPaolo Bonzini } 6951c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6952c50d8ae3SPaolo Bonzini } 6953c50d8ae3SPaolo Bonzini 6954c50d8ae3SPaolo Bonzini return 0; 6955c50d8ae3SPaolo Bonzini } 6956c50d8ae3SPaolo Bonzini 69571d0e8480SSean Christopherson /* 69581d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 69591d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 6960c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 6961c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 69621d0e8480SSean Christopherson */ 6963982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 6964c50d8ae3SPaolo Bonzini { 6965c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6966c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 6967c3e0c8c2SSean Christopherson 69681f98f2bdSDavid Matlack /* 69691f98f2bdSDavid Matlack * Snapshot userspace's desire to enable the TDP MMU. Whether or not the 69701f98f2bdSDavid Matlack * TDP MMU is actually enabled is determined in kvm_configure_mmu() 69711f98f2bdSDavid Matlack * when the vendor module is loaded. 69721f98f2bdSDavid Matlack */ 69731f98f2bdSDavid Matlack tdp_mmu_allowed = tdp_mmu_enabled; 69741f98f2bdSDavid Matlack 6975c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 69761d0e8480SSean Christopherson } 69771d0e8480SSean Christopherson 69781d0e8480SSean Christopherson /* 69791d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 69801d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 69811d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 69821d0e8480SSean Christopherson */ 69831d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 69841d0e8480SSean Christopherson { 69851d0e8480SSean Christopherson int ret = -ENOMEM; 6986c50d8ae3SPaolo Bonzini 6987c50d8ae3SPaolo Bonzini /* 6988c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6989c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6990c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6991c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6992c50d8ae3SPaolo Bonzini */ 6993c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6994c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 69957a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6996c50d8ae3SPaolo Bonzini 6997c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6998c50d8ae3SPaolo Bonzini 6999c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 7000c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 7001c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 7002c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 7003c50d8ae3SPaolo Bonzini goto out; 7004c50d8ae3SPaolo Bonzini 7005c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 7006c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 7007c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 7008c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 7009c50d8ae3SPaolo Bonzini goto out; 7010c50d8ae3SPaolo Bonzini 7011c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 7012c50d8ae3SPaolo Bonzini goto out; 7013c50d8ae3SPaolo Bonzini 7014e5985c40SQi Zheng mmu_shrinker = shrinker_alloc(0, "x86-mmu"); 7015e5985c40SQi Zheng if (!mmu_shrinker) 7016d7c9bfb9SMiaohe Lin goto out_shrinker; 7017c50d8ae3SPaolo Bonzini 7018e5985c40SQi Zheng mmu_shrinker->count_objects = mmu_shrink_count; 7019e5985c40SQi Zheng mmu_shrinker->scan_objects = mmu_shrink_scan; 7020e5985c40SQi Zheng mmu_shrinker->seeks = DEFAULT_SEEKS * 10; 7021e5985c40SQi Zheng 7022e5985c40SQi Zheng shrinker_register(mmu_shrinker); 7023e5985c40SQi Zheng 7024c50d8ae3SPaolo Bonzini return 0; 7025c50d8ae3SPaolo Bonzini 7026d7c9bfb9SMiaohe Lin out_shrinker: 7027d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 7028c50d8ae3SPaolo Bonzini out: 7029c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 7030c50d8ae3SPaolo Bonzini return ret; 7031c50d8ae3SPaolo Bonzini } 7032c50d8ae3SPaolo Bonzini 7033c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 7034c50d8ae3SPaolo Bonzini { 7035c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 7036c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 7037c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 7038c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 7039c50d8ae3SPaolo Bonzini } 7040c50d8ae3SPaolo Bonzini 70411d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 7042c50d8ae3SPaolo Bonzini { 7043c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 7044c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 7045e5985c40SQi Zheng shrinker_free(mmu_shrinker); 7046c50d8ae3SPaolo Bonzini } 7047c50d8ae3SPaolo Bonzini 7048f47491d7SSean Christopherson /* 7049f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 7050f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 7051f47491d7SSean Christopherson */ 7052f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 7053f47491d7SSean Christopherson { 7054f47491d7SSean Christopherson /* 7055f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 7056f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 7057f47491d7SSean Christopherson */ 7058f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 7059f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 7060f47491d7SSean Christopherson 7061f47491d7SSean Christopherson if (!enabled || !ratio) 7062f47491d7SSean Christopherson return false; 7063f47491d7SSean Christopherson 7064f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 7065f47491d7SSean Christopherson if (!*period) { 7066f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 7067f47491d7SSean Christopherson ratio = min(ratio, 3600u); 7068f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 7069f47491d7SSean Christopherson } 7070f47491d7SSean Christopherson return true; 7071f47491d7SSean Christopherson } 7072f47491d7SSean Christopherson 70734dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 7074c50d8ae3SPaolo Bonzini { 70754dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 70764dfe4f40SJunaid Shahid uint old_period, new_period; 7077c50d8ae3SPaolo Bonzini int err; 7078c50d8ae3SPaolo Bonzini 70790b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 70800b210fafSSean Christopherson return -EPERM; 70810b210fafSSean Christopherson 7082f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 70834dfe4f40SJunaid Shahid 7084c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 7085c50d8ae3SPaolo Bonzini if (err) 7086c50d8ae3SPaolo Bonzini return err; 7087c50d8ae3SPaolo Bonzini 7088f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 70894dfe4f40SJunaid Shahid 7090f47491d7SSean Christopherson if (is_recovery_enabled && 70914dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 7092c50d8ae3SPaolo Bonzini struct kvm *kvm; 7093c50d8ae3SPaolo Bonzini 7094c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 7095c50d8ae3SPaolo Bonzini 7096c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 709755c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 7098c50d8ae3SPaolo Bonzini 7099c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 7100c50d8ae3SPaolo Bonzini } 7101c50d8ae3SPaolo Bonzini 7102c50d8ae3SPaolo Bonzini return err; 7103c50d8ae3SPaolo Bonzini } 7104c50d8ae3SPaolo Bonzini 710555c510e2SSean Christopherson static void kvm_recover_nx_huge_pages(struct kvm *kvm) 7106c50d8ae3SPaolo Bonzini { 7107ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 7108eb298605SDavid Matlack struct kvm_memory_slot *slot; 7109c50d8ae3SPaolo Bonzini int rcu_idx; 7110c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 7111c50d8ae3SPaolo Bonzini unsigned int ratio; 7112c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 7113048f4980SSean Christopherson bool flush = false; 7114c50d8ae3SPaolo Bonzini ulong to_zap; 7115c50d8ae3SPaolo Bonzini 7116c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 7117531810caSBen Gardon write_lock(&kvm->mmu_lock); 7118c50d8ae3SPaolo Bonzini 7119bb95dfb9SSean Christopherson /* 7120bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 7121bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 7122bb95dfb9SSean Christopherson * callback. 7123bb95dfb9SSean Christopherson */ 7124bb95dfb9SSean Christopherson rcu_read_lock(); 7125bb95dfb9SSean Christopherson 7126c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 7127ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 71287d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 712955c510e2SSean Christopherson if (list_empty(&kvm->arch.possible_nx_huge_pages)) 71307d919c7aSSean Christopherson break; 71317d919c7aSSean Christopherson 7132c50d8ae3SPaolo Bonzini /* 7133c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 713455c510e2SSean Christopherson * because the number of shadow pages that be replaced with an 713555c510e2SSean Christopherson * NX huge page is expected to be relatively small compared to 713655c510e2SSean Christopherson * the total number of shadow pages. And because the TDP MMU 713755c510e2SSean Christopherson * doesn't use active_mmu_pages. 7138c50d8ae3SPaolo Bonzini */ 713955c510e2SSean Christopherson sp = list_first_entry(&kvm->arch.possible_nx_huge_pages, 7140c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 714155c510e2SSean Christopherson possible_nx_huge_page_link); 714255c510e2SSean Christopherson WARN_ON_ONCE(!sp->nx_huge_page_disallowed); 7143eb298605SDavid Matlack WARN_ON_ONCE(!sp->role.direct); 7144eb298605SDavid Matlack 7145eb298605SDavid Matlack /* 7146eb298605SDavid Matlack * Unaccount and do not attempt to recover any NX Huge Pages 7147eb298605SDavid Matlack * that are being dirty tracked, as they would just be faulted 7148eb298605SDavid Matlack * back in as 4KiB pages. The NX Huge Pages in this slot will be 7149eb298605SDavid Matlack * recovered, along with all the other huge pages in the slot, 7150eb298605SDavid Matlack * when dirty logging is disabled. 71516c7b2202SPaolo Bonzini * 71526c7b2202SPaolo Bonzini * Since gfn_to_memslot() is relatively expensive, it helps to 71536c7b2202SPaolo Bonzini * skip it if it the test cannot possibly return true. On the 71546c7b2202SPaolo Bonzini * other hand, if any memslot has logging enabled, chances are 71556c7b2202SPaolo Bonzini * good that all of them do, in which case unaccount_nx_huge_page() 71566c7b2202SPaolo Bonzini * is much cheaper than zapping the page. 71576c7b2202SPaolo Bonzini * 71586c7b2202SPaolo Bonzini * If a memslot update is in progress, reading an incorrect value 71596c7b2202SPaolo Bonzini * of kvm->nr_memslots_dirty_logging is not a problem: if it is 71606c7b2202SPaolo Bonzini * becoming zero, gfn_to_memslot() will be done unnecessarily; if 71616c7b2202SPaolo Bonzini * it is becoming nonzero, the page will be zapped unnecessarily. 71626c7b2202SPaolo Bonzini * Either way, this only affects efficiency in racy situations, 71636c7b2202SPaolo Bonzini * and not correctness. 7164eb298605SDavid Matlack */ 71656c7b2202SPaolo Bonzini slot = NULL; 71666c7b2202SPaolo Bonzini if (atomic_read(&kvm->nr_memslots_dirty_logging)) { 7167817fa998SSean Christopherson struct kvm_memslots *slots; 7168817fa998SSean Christopherson 7169817fa998SSean Christopherson slots = kvm_memslots_for_spte_role(kvm, sp->role); 7170817fa998SSean Christopherson slot = __gfn_to_memslot(slots, sp->gfn); 71716c7b2202SPaolo Bonzini WARN_ON_ONCE(!slot); 717229cf0f50SBen Gardon } 7173c50d8ae3SPaolo Bonzini 7174eb298605SDavid Matlack if (slot && kvm_slot_dirty_track_enabled(slot)) 7175eb298605SDavid Matlack unaccount_nx_huge_page(kvm, sp); 7176eb298605SDavid Matlack else if (is_tdp_mmu_page(sp)) 7177c50d8ae3SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 71783a056757SSean Christopherson else 7179c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 718055c510e2SSean Christopherson WARN_ON_ONCE(sp->nx_huge_page_disallowed); 7181c50d8ae3SPaolo Bonzini 7182531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 7183048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7184bb95dfb9SSean Christopherson rcu_read_unlock(); 7185bb95dfb9SSean Christopherson 7186531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 7187048f4980SSean Christopherson flush = false; 7188bb95dfb9SSean Christopherson 7189bb95dfb9SSean Christopherson rcu_read_lock(); 7190c50d8ae3SPaolo Bonzini } 7191c50d8ae3SPaolo Bonzini } 7192048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7193c50d8ae3SPaolo Bonzini 7194bb95dfb9SSean Christopherson rcu_read_unlock(); 7195bb95dfb9SSean Christopherson 7196531810caSBen Gardon write_unlock(&kvm->mmu_lock); 7197c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 7198c50d8ae3SPaolo Bonzini } 7199c50d8ae3SPaolo Bonzini 720055c510e2SSean Christopherson static long get_nx_huge_page_recovery_timeout(u64 start_time) 7201c50d8ae3SPaolo Bonzini { 7202f47491d7SSean Christopherson bool enabled; 7203f47491d7SSean Christopherson uint period; 72044dfe4f40SJunaid Shahid 7205f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 72064dfe4f40SJunaid Shahid 7207f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 7208c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 7209c50d8ae3SPaolo Bonzini } 7210c50d8ae3SPaolo Bonzini 721155c510e2SSean Christopherson static int kvm_nx_huge_page_recovery_worker(struct kvm *kvm, uintptr_t data) 7212c50d8ae3SPaolo Bonzini { 7213c50d8ae3SPaolo Bonzini u64 start_time; 7214c50d8ae3SPaolo Bonzini long remaining_time; 7215c50d8ae3SPaolo Bonzini 7216c50d8ae3SPaolo Bonzini while (true) { 7217c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 721855c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7219c50d8ae3SPaolo Bonzini 7220c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7221c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 7222c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 722355c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7224c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7225c50d8ae3SPaolo Bonzini } 7226c50d8ae3SPaolo Bonzini 7227c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 7228c50d8ae3SPaolo Bonzini 7229c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 7230c50d8ae3SPaolo Bonzini return 0; 7231c50d8ae3SPaolo Bonzini 723255c510e2SSean Christopherson kvm_recover_nx_huge_pages(kvm); 7233c50d8ae3SPaolo Bonzini } 7234c50d8ae3SPaolo Bonzini } 7235c50d8ae3SPaolo Bonzini 7236c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 7237c50d8ae3SPaolo Bonzini { 7238c50d8ae3SPaolo Bonzini int err; 7239c50d8ae3SPaolo Bonzini 72400b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 72410b210fafSSean Christopherson return 0; 72420b210fafSSean Christopherson 724355c510e2SSean Christopherson err = kvm_vm_create_worker_thread(kvm, kvm_nx_huge_page_recovery_worker, 0, 7244c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 724555c510e2SSean Christopherson &kvm->arch.nx_huge_page_recovery_thread); 7246c50d8ae3SPaolo Bonzini if (!err) 724755c510e2SSean Christopherson kthread_unpark(kvm->arch.nx_huge_page_recovery_thread); 7248c50d8ae3SPaolo Bonzini 7249c50d8ae3SPaolo Bonzini return err; 7250c50d8ae3SPaolo Bonzini } 7251c50d8ae3SPaolo Bonzini 7252c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 7253c50d8ae3SPaolo Bonzini { 725455c510e2SSean Christopherson if (kvm->arch.nx_huge_page_recovery_thread) 725555c510e2SSean Christopherson kthread_stop(kvm->arch.nx_huge_page_recovery_thread); 7256c50d8ae3SPaolo Bonzini } 725790b4fe17SChao Peng 725890b4fe17SChao Peng #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES 72598dd2eee9SChao Peng bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm, 72608dd2eee9SChao Peng struct kvm_gfn_range *range) 72618dd2eee9SChao Peng { 72628dd2eee9SChao Peng /* 72638dd2eee9SChao Peng * Zap SPTEs even if the slot can't be mapped PRIVATE. KVM x86 only 72648dd2eee9SChao Peng * supports KVM_MEMORY_ATTRIBUTE_PRIVATE, and so it *seems* like KVM 72658dd2eee9SChao Peng * can simply ignore such slots. But if userspace is making memory 72668dd2eee9SChao Peng * PRIVATE, then KVM must prevent the guest from accessing the memory 72678dd2eee9SChao Peng * as shared. And if userspace is making memory SHARED and this point 72688dd2eee9SChao Peng * is reached, then at least one page within the range was previously 72698dd2eee9SChao Peng * PRIVATE, i.e. the slot's possible hugepage ranges are changing. 72708dd2eee9SChao Peng * Zapping SPTEs in this case ensures KVM will reassess whether or not 72718dd2eee9SChao Peng * a hugepage can be used for affected ranges. 72728dd2eee9SChao Peng */ 72738dd2eee9SChao Peng if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm))) 72748dd2eee9SChao Peng return false; 72758dd2eee9SChao Peng 72768dd2eee9SChao Peng return kvm_unmap_gfn_range(kvm, range); 72778dd2eee9SChao Peng } 72788dd2eee9SChao Peng 727990b4fe17SChao Peng static bool hugepage_test_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 728090b4fe17SChao Peng int level) 728190b4fe17SChao Peng { 728290b4fe17SChao Peng return lpage_info_slot(gfn, slot, level)->disallow_lpage & KVM_LPAGE_MIXED_FLAG; 728390b4fe17SChao Peng } 728490b4fe17SChao Peng 728590b4fe17SChao Peng static void hugepage_clear_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 728690b4fe17SChao Peng int level) 728790b4fe17SChao Peng { 728890b4fe17SChao Peng lpage_info_slot(gfn, slot, level)->disallow_lpage &= ~KVM_LPAGE_MIXED_FLAG; 728990b4fe17SChao Peng } 729090b4fe17SChao Peng 729190b4fe17SChao Peng static void hugepage_set_mixed(struct kvm_memory_slot *slot, gfn_t gfn, 729290b4fe17SChao Peng int level) 729390b4fe17SChao Peng { 729490b4fe17SChao Peng lpage_info_slot(gfn, slot, level)->disallow_lpage |= KVM_LPAGE_MIXED_FLAG; 729590b4fe17SChao Peng } 729690b4fe17SChao Peng 729790b4fe17SChao Peng static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot, 729890b4fe17SChao Peng gfn_t gfn, int level, unsigned long attrs) 729990b4fe17SChao Peng { 730090b4fe17SChao Peng const unsigned long start = gfn; 730190b4fe17SChao Peng const unsigned long end = start + KVM_PAGES_PER_HPAGE(level); 730290b4fe17SChao Peng 730390b4fe17SChao Peng if (level == PG_LEVEL_2M) 730490b4fe17SChao Peng return kvm_range_has_memory_attributes(kvm, start, end, attrs); 730590b4fe17SChao Peng 730690b4fe17SChao Peng for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) { 730790b4fe17SChao Peng if (hugepage_test_mixed(slot, gfn, level - 1) || 730890b4fe17SChao Peng attrs != kvm_get_memory_attributes(kvm, gfn)) 730990b4fe17SChao Peng return false; 731090b4fe17SChao Peng } 731190b4fe17SChao Peng return true; 731290b4fe17SChao Peng } 731390b4fe17SChao Peng 731490b4fe17SChao Peng bool kvm_arch_post_set_memory_attributes(struct kvm *kvm, 731590b4fe17SChao Peng struct kvm_gfn_range *range) 731690b4fe17SChao Peng { 731790b4fe17SChao Peng unsigned long attrs = range->arg.attributes; 731890b4fe17SChao Peng struct kvm_memory_slot *slot = range->slot; 731990b4fe17SChao Peng int level; 732090b4fe17SChao Peng 732190b4fe17SChao Peng lockdep_assert_held_write(&kvm->mmu_lock); 732290b4fe17SChao Peng lockdep_assert_held(&kvm->slots_lock); 732390b4fe17SChao Peng 732490b4fe17SChao Peng /* 732590b4fe17SChao Peng * Calculate which ranges can be mapped with hugepages even if the slot 732690b4fe17SChao Peng * can't map memory PRIVATE. KVM mustn't create a SHARED hugepage over 732790b4fe17SChao Peng * a range that has PRIVATE GFNs, and conversely converting a range to 732890b4fe17SChao Peng * SHARED may now allow hugepages. 732990b4fe17SChao Peng */ 733090b4fe17SChao Peng if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm))) 733190b4fe17SChao Peng return false; 733290b4fe17SChao Peng 733390b4fe17SChao Peng /* 733490b4fe17SChao Peng * The sequence matters here: upper levels consume the result of lower 733590b4fe17SChao Peng * level's scanning. 733690b4fe17SChao Peng */ 733790b4fe17SChao Peng for (level = PG_LEVEL_2M; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) { 733890b4fe17SChao Peng gfn_t nr_pages = KVM_PAGES_PER_HPAGE(level); 733990b4fe17SChao Peng gfn_t gfn = gfn_round_for_level(range->start, level); 734090b4fe17SChao Peng 734190b4fe17SChao Peng /* Process the head page if it straddles the range. */ 734290b4fe17SChao Peng if (gfn != range->start || gfn + nr_pages > range->end) { 734390b4fe17SChao Peng /* 734490b4fe17SChao Peng * Skip mixed tracking if the aligned gfn isn't covered 734590b4fe17SChao Peng * by the memslot, KVM can't use a hugepage due to the 734690b4fe17SChao Peng * misaligned address regardless of memory attributes. 734790b4fe17SChao Peng */ 734890b4fe17SChao Peng if (gfn >= slot->base_gfn) { 734990b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 735090b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 735190b4fe17SChao Peng else 735290b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 735390b4fe17SChao Peng } 735490b4fe17SChao Peng gfn += nr_pages; 735590b4fe17SChao Peng } 735690b4fe17SChao Peng 735790b4fe17SChao Peng /* 735890b4fe17SChao Peng * Pages entirely covered by the range are guaranteed to have 735990b4fe17SChao Peng * only the attributes which were just set. 736090b4fe17SChao Peng */ 736190b4fe17SChao Peng for ( ; gfn + nr_pages <= range->end; gfn += nr_pages) 736290b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 736390b4fe17SChao Peng 736490b4fe17SChao Peng /* 736590b4fe17SChao Peng * Process the last tail page if it straddles the range and is 736690b4fe17SChao Peng * contained by the memslot. Like the head page, KVM can't 736790b4fe17SChao Peng * create a hugepage if the slot size is misaligned. 736890b4fe17SChao Peng */ 736990b4fe17SChao Peng if (gfn < range->end && 737090b4fe17SChao Peng (gfn + nr_pages) <= (slot->base_gfn + slot->npages)) { 737190b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 737290b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 737390b4fe17SChao Peng else 737490b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 737590b4fe17SChao Peng } 737690b4fe17SChao Peng } 737790b4fe17SChao Peng return false; 737890b4fe17SChao Peng } 737990b4fe17SChao Peng 738090b4fe17SChao Peng void kvm_mmu_init_memslot_memory_attributes(struct kvm *kvm, 738190b4fe17SChao Peng struct kvm_memory_slot *slot) 738290b4fe17SChao Peng { 738390b4fe17SChao Peng int level; 738490b4fe17SChao Peng 738590b4fe17SChao Peng if (!kvm_arch_has_private_mem(kvm)) 738690b4fe17SChao Peng return; 738790b4fe17SChao Peng 738890b4fe17SChao Peng for (level = PG_LEVEL_2M; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) { 738990b4fe17SChao Peng /* 739090b4fe17SChao Peng * Don't bother tracking mixed attributes for pages that can't 739190b4fe17SChao Peng * be huge due to alignment, i.e. process only pages that are 739290b4fe17SChao Peng * entirely contained by the memslot. 739390b4fe17SChao Peng */ 739490b4fe17SChao Peng gfn_t end = gfn_round_for_level(slot->base_gfn + slot->npages, level); 739590b4fe17SChao Peng gfn_t start = gfn_round_for_level(slot->base_gfn, level); 739690b4fe17SChao Peng gfn_t nr_pages = KVM_PAGES_PER_HPAGE(level); 739790b4fe17SChao Peng gfn_t gfn; 739890b4fe17SChao Peng 739990b4fe17SChao Peng if (start < slot->base_gfn) 740090b4fe17SChao Peng start += nr_pages; 740190b4fe17SChao Peng 740290b4fe17SChao Peng /* 740390b4fe17SChao Peng * Unlike setting attributes, every potential hugepage needs to 740490b4fe17SChao Peng * be manually checked as the attributes may already be mixed. 740590b4fe17SChao Peng */ 740690b4fe17SChao Peng for (gfn = start; gfn < end; gfn += nr_pages) { 740790b4fe17SChao Peng unsigned long attrs = kvm_get_memory_attributes(kvm, gfn); 740890b4fe17SChao Peng 740990b4fe17SChao Peng if (hugepage_has_attrs(kvm, slot, gfn, level, attrs)) 741090b4fe17SChao Peng hugepage_clear_mixed(slot, gfn, level); 741190b4fe17SChao Peng else 741290b4fe17SChao Peng hugepage_set_mixed(slot, gfn, level); 741390b4fe17SChao Peng } 741490b4fe17SChao Peng } 741590b4fe17SChao Peng } 741690b4fe17SChao Peng #endif 7417