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" 28c50d8ae3SPaolo Bonzini #include "cpuid.h" 295a9624afSPaolo Bonzini #include "spte.h" 30c50d8ae3SPaolo Bonzini 31c50d8ae3SPaolo Bonzini #include <linux/kvm_host.h> 32c50d8ae3SPaolo Bonzini #include <linux/types.h> 33c50d8ae3SPaolo Bonzini #include <linux/string.h> 34c50d8ae3SPaolo Bonzini #include <linux/mm.h> 35c50d8ae3SPaolo Bonzini #include <linux/highmem.h> 36c50d8ae3SPaolo Bonzini #include <linux/moduleparam.h> 37c50d8ae3SPaolo Bonzini #include <linux/export.h> 38c50d8ae3SPaolo Bonzini #include <linux/swap.h> 39c50d8ae3SPaolo Bonzini #include <linux/hugetlb.h> 40c50d8ae3SPaolo Bonzini #include <linux/compiler.h> 41c50d8ae3SPaolo Bonzini #include <linux/srcu.h> 42c50d8ae3SPaolo Bonzini #include <linux/slab.h> 43c50d8ae3SPaolo Bonzini #include <linux/sched/signal.h> 44c50d8ae3SPaolo Bonzini #include <linux/uaccess.h> 45c50d8ae3SPaolo Bonzini #include <linux/hash.h> 46c50d8ae3SPaolo Bonzini #include <linux/kern_levels.h> 47c50d8ae3SPaolo Bonzini #include <linux/kthread.h> 48c50d8ae3SPaolo Bonzini 49c50d8ae3SPaolo Bonzini #include <asm/page.h> 50eb243d1dSIngo Molnar #include <asm/memtype.h> 51c50d8ae3SPaolo Bonzini #include <asm/cmpxchg.h> 52c50d8ae3SPaolo Bonzini #include <asm/io.h> 534a98623dSSean Christopherson #include <asm/set_memory.h> 54c50d8ae3SPaolo Bonzini #include <asm/vmx.h> 55c50d8ae3SPaolo Bonzini #include <asm/kvm_page_track.h> 56c50d8ae3SPaolo Bonzini #include "trace.h" 57c50d8ae3SPaolo Bonzini 58c50d8ae3SPaolo Bonzini extern bool itlb_multihit_kvm_mitigation; 59c50d8ae3SPaolo Bonzini 60a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 614dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 62c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 63c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 64c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 65c50d8ae3SPaolo Bonzini #else 66c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 67c50d8ae3SPaolo Bonzini #endif 68c50d8ae3SPaolo Bonzini 69c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 704dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 71c50d8ae3SPaolo Bonzini 72d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 73c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 74c50d8ae3SPaolo Bonzini .get = param_get_bool, 75c50d8ae3SPaolo Bonzini }; 76c50d8ae3SPaolo Bonzini 774dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 784dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 79c50d8ae3SPaolo Bonzini .get = param_get_uint, 80c50d8ae3SPaolo Bonzini }; 81c50d8ae3SPaolo Bonzini 82c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 83c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 844dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 85c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 86c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 874dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 884dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 894dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 90c50d8ae3SPaolo Bonzini 9171fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9271fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9371fe7013SSean Christopherson 94c50d8ae3SPaolo Bonzini /* 95c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 96c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 97c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 98c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 99c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 100c50d8ae3SPaolo Bonzini */ 101c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 102c50d8ae3SPaolo Bonzini 1031f98f2bdSDavid Matlack bool __ro_after_init tdp_mmu_allowed; 1041f98f2bdSDavid Matlack 1051f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 1061f98f2bdSDavid Matlack bool __read_mostly tdp_mmu_enabled = true; 1071f98f2bdSDavid Matlack module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0444); 1081f98f2bdSDavid Matlack #endif 1091f98f2bdSDavid Matlack 1101d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 111746700d2SWei Huang static int tdp_root_level __read_mostly; 11283013059SSean Christopherson static int max_tdp_level __read_mostly; 113703c335dSSean Christopherson 114c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1155a9624afSPaolo Bonzini bool dbg = 0; 116c50d8ae3SPaolo Bonzini module_param(dbg, bool, 0644); 117c50d8ae3SPaolo Bonzini #endif 118c50d8ae3SPaolo Bonzini 119c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 120c50d8ae3SPaolo Bonzini 121c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 122c50d8ae3SPaolo Bonzini 123dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 12413236e25SPeter Xu #define PTE_LIST_EXT 14 125c50d8ae3SPaolo Bonzini 12613236e25SPeter Xu /* 12713236e25SPeter Xu * Slight optimization of cacheline layout, by putting `more' and `spte_count' 12813236e25SPeter Xu * at the start; then accessing it will only use one single cacheline for 12913236e25SPeter Xu * either full (entries==PTE_LIST_EXT) case or entries<=6. 13013236e25SPeter Xu */ 131c50d8ae3SPaolo Bonzini struct pte_list_desc { 132c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 13313236e25SPeter Xu /* 13413236e25SPeter Xu * Stores number of entries stored in the pte_list_desc. No need to be 13513236e25SPeter Xu * u64 but just for easier alignment. When PTE_LIST_EXT, means full. 13613236e25SPeter Xu */ 13713236e25SPeter Xu u64 spte_count; 13813236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 139c50d8ae3SPaolo Bonzini }; 140c50d8ae3SPaolo Bonzini 141c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 142c50d8ae3SPaolo Bonzini u64 addr; 143c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 144c50d8ae3SPaolo Bonzini u64 *sptep; 145c50d8ae3SPaolo Bonzini int level; 146c50d8ae3SPaolo Bonzini unsigned index; 147c50d8ae3SPaolo Bonzini }; 148c50d8ae3SPaolo Bonzini 149c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 150c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 151c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 152c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 153c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 154c50d8ae3SPaolo Bonzini 155c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 156c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 157c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 158c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 159c50d8ae3SPaolo Bonzini 160c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 161c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 162c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 163c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 164c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 165c50d8ae3SPaolo Bonzini 166c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 16702c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 168c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 169c50d8ae3SPaolo Bonzini 170c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 171c50d8ae3SPaolo Bonzini 172594e91a1SSean Christopherson struct kvm_mmu_role_regs { 173594e91a1SSean Christopherson const unsigned long cr0; 174594e91a1SSean Christopherson const unsigned long cr4; 175594e91a1SSean Christopherson const u64 efer; 176594e91a1SSean Christopherson }; 177594e91a1SSean Christopherson 178c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 179c50d8ae3SPaolo Bonzini #include "mmutrace.h" 180c50d8ae3SPaolo Bonzini 181594e91a1SSean Christopherson /* 182594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1837a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 184594e91a1SSean Christopherson * the single source of truth for the MMU's state. 185594e91a1SSean Christopherson */ 186594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 18782ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 18882ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 189594e91a1SSean Christopherson { \ 190594e91a1SSean Christopherson return !!(regs->reg & flag); \ 191594e91a1SSean Christopherson } 192594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 193594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 194594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 195594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 196594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 197594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 198594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 199594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 200594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 201594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 202594e91a1SSean Christopherson 20360667724SSean Christopherson /* 20460667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 20560667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 20660667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 20760667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 20860667724SSean Christopherson */ 20960667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2104ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 21160667724SSean Christopherson { \ 212e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 21360667724SSean Christopherson } 21460667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 21560667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 21660667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 21760667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 21860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 21960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 22060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 22156b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 22260667724SSean Christopherson 223faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 224faf72962SPaolo Bonzini { 225faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 226faf72962SPaolo Bonzini } 227faf72962SPaolo Bonzini 228faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 229faf72962SPaolo Bonzini { 230faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 231faf72962SPaolo Bonzini } 232faf72962SPaolo Bonzini 233594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 234594e91a1SSean Christopherson { 235594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 236594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 237594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 238594e91a1SSean Christopherson .efer = vcpu->arch.efer, 239594e91a1SSean Christopherson }; 240594e91a1SSean Christopherson 241594e91a1SSean Christopherson return regs; 242594e91a1SSean Christopherson } 243c50d8ae3SPaolo Bonzini 244c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 245c50d8ae3SPaolo Bonzini { 246afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 247c50d8ae3SPaolo Bonzini } 248c50d8ae3SPaolo Bonzini 249c50d8ae3SPaolo Bonzini static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm, 250c50d8ae3SPaolo Bonzini struct kvm_tlb_range *range) 251c50d8ae3SPaolo Bonzini { 252c50d8ae3SPaolo Bonzini int ret = -ENOTSUPP; 253c50d8ae3SPaolo Bonzini 254afaf0b2fSSean Christopherson if (range && kvm_x86_ops.tlb_remote_flush_with_range) 255b3646477SJason Baron ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range); 256c50d8ae3SPaolo Bonzini 257c50d8ae3SPaolo Bonzini if (ret) 258c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 259c50d8ae3SPaolo Bonzini } 260c50d8ae3SPaolo Bonzini 2612f2fad08SBen Gardon void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 262c50d8ae3SPaolo Bonzini u64 start_gfn, u64 pages) 263c50d8ae3SPaolo Bonzini { 264c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 265c50d8ae3SPaolo Bonzini 266c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 267c50d8ae3SPaolo Bonzini range.pages = pages; 268c50d8ae3SPaolo Bonzini 269c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_range(kvm, &range); 270c50d8ae3SPaolo Bonzini } 271c50d8ae3SPaolo Bonzini 2728f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2738f79b064SBen Gardon unsigned int access) 2748f79b064SBen Gardon { 275c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2768f79b064SBen Gardon 277c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 278c236d962SSean Christopherson mmu_spte_set(sptep, spte); 279c50d8ae3SPaolo Bonzini } 280c50d8ae3SPaolo Bonzini 281c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 282c50d8ae3SPaolo Bonzini { 283c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 284c50d8ae3SPaolo Bonzini 2858a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 286c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 287c50d8ae3SPaolo Bonzini 288c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 289c50d8ae3SPaolo Bonzini } 290c50d8ae3SPaolo Bonzini 291c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 292c50d8ae3SPaolo Bonzini { 293c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 294c50d8ae3SPaolo Bonzini } 295c50d8ae3SPaolo Bonzini 296c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 297c50d8ae3SPaolo Bonzini { 298c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 299c50d8ae3SPaolo Bonzini 300c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 301c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 302c50d8ae3SPaolo Bonzini return false; 303c50d8ae3SPaolo Bonzini 304c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 305c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 306c50d8ae3SPaolo Bonzini 307c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 308c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 309c50d8ae3SPaolo Bonzini } 310c50d8ae3SPaolo Bonzini 311c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 312c50d8ae3SPaolo Bonzini { 313c50d8ae3SPaolo Bonzini return 1; 314c50d8ae3SPaolo Bonzini } 315c50d8ae3SPaolo Bonzini 316c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 317c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 318c50d8ae3SPaolo Bonzini { 319c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 320c50d8ae3SPaolo Bonzini } 321c50d8ae3SPaolo Bonzini 322c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 323c50d8ae3SPaolo Bonzini { 324c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 325c50d8ae3SPaolo Bonzini } 326c50d8ae3SPaolo Bonzini 327c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 328c50d8ae3SPaolo Bonzini { 329c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 330c50d8ae3SPaolo Bonzini } 331c50d8ae3SPaolo Bonzini 332c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 333c50d8ae3SPaolo Bonzini { 334c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 335c50d8ae3SPaolo Bonzini } 336c50d8ae3SPaolo Bonzini #else 337c50d8ae3SPaolo Bonzini union split_spte { 338c50d8ae3SPaolo Bonzini struct { 339c50d8ae3SPaolo Bonzini u32 spte_low; 340c50d8ae3SPaolo Bonzini u32 spte_high; 341c50d8ae3SPaolo Bonzini }; 342c50d8ae3SPaolo Bonzini u64 spte; 343c50d8ae3SPaolo Bonzini }; 344c50d8ae3SPaolo Bonzini 345c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 346c50d8ae3SPaolo Bonzini { 34757354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 348c50d8ae3SPaolo Bonzini 349c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 350c50d8ae3SPaolo Bonzini return; 351c50d8ae3SPaolo Bonzini 352c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 353c50d8ae3SPaolo Bonzini smp_wmb(); 354c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 355c50d8ae3SPaolo Bonzini } 356c50d8ae3SPaolo Bonzini 357c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 358c50d8ae3SPaolo Bonzini { 359c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 360c50d8ae3SPaolo Bonzini 361c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 362c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 363c50d8ae3SPaolo Bonzini 364c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 365c50d8ae3SPaolo Bonzini 366c50d8ae3SPaolo Bonzini /* 367c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 368c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 369c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 370c50d8ae3SPaolo Bonzini */ 371c50d8ae3SPaolo Bonzini smp_wmb(); 372c50d8ae3SPaolo Bonzini 373c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 374c50d8ae3SPaolo Bonzini } 375c50d8ae3SPaolo Bonzini 376c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(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 WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 384c50d8ae3SPaolo Bonzini 385c50d8ae3SPaolo Bonzini /* 386c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 387c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 388c50d8ae3SPaolo Bonzini */ 389c50d8ae3SPaolo Bonzini smp_wmb(); 390c50d8ae3SPaolo Bonzini 391c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 392c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 393c50d8ae3SPaolo Bonzini } 394c50d8ae3SPaolo Bonzini 395c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 396c50d8ae3SPaolo Bonzini { 397c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 398c50d8ae3SPaolo Bonzini 399c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 400c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 401c50d8ae3SPaolo Bonzini 402c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 403c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 404c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 405c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 406c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 407c50d8ae3SPaolo Bonzini 408c50d8ae3SPaolo Bonzini return orig.spte; 409c50d8ae3SPaolo Bonzini } 410c50d8ae3SPaolo Bonzini 411c50d8ae3SPaolo Bonzini /* 412c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 413c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 414c50d8ae3SPaolo Bonzini * 415aed02fe3SSean Christopherson * An spte tlb flush may be pending, because kvm_set_pte_rmap 416c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 417c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 418c50d8ae3SPaolo Bonzini * 419c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 420c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 421c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 422c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 423c50d8ae3SPaolo Bonzini * 424c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 425c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 426c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 427c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 428c50d8ae3SPaolo Bonzini */ 429c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 430c50d8ae3SPaolo Bonzini { 43157354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 432c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 433c50d8ae3SPaolo Bonzini int count; 434c50d8ae3SPaolo Bonzini 435c50d8ae3SPaolo Bonzini retry: 436c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 437c50d8ae3SPaolo Bonzini smp_rmb(); 438c50d8ae3SPaolo Bonzini 439c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 440c50d8ae3SPaolo Bonzini smp_rmb(); 441c50d8ae3SPaolo Bonzini 442c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 443c50d8ae3SPaolo Bonzini smp_rmb(); 444c50d8ae3SPaolo Bonzini 445c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 446c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 447c50d8ae3SPaolo Bonzini goto retry; 448c50d8ae3SPaolo Bonzini 449c50d8ae3SPaolo Bonzini return spte.spte; 450c50d8ae3SPaolo Bonzini } 451c50d8ae3SPaolo Bonzini #endif 452c50d8ae3SPaolo Bonzini 453c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 454c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 455c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 456c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 457c50d8ae3SPaolo Bonzini * the spte. 458c50d8ae3SPaolo Bonzini */ 459c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 460c50d8ae3SPaolo Bonzini { 461c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 462c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 463c50d8ae3SPaolo Bonzini } 464c50d8ae3SPaolo Bonzini 465c50d8ae3SPaolo Bonzini /* 466c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 467c50d8ae3SPaolo Bonzini * accessed/dirty status. 468c50d8ae3SPaolo Bonzini */ 469c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 470c50d8ae3SPaolo Bonzini { 471c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 472c50d8ae3SPaolo Bonzini 473c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 474115111efSDavid Matlack check_spte_writable_invariants(new_spte); 475c50d8ae3SPaolo Bonzini 476c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 477c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 478c50d8ae3SPaolo Bonzini return old_spte; 479c50d8ae3SPaolo Bonzini } 480c50d8ae3SPaolo Bonzini 481c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 482c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 483c50d8ae3SPaolo Bonzini else 484c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 485c50d8ae3SPaolo Bonzini 486c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 487c50d8ae3SPaolo Bonzini 488c50d8ae3SPaolo Bonzini return old_spte; 489c50d8ae3SPaolo Bonzini } 490c50d8ae3SPaolo Bonzini 491c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 492c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 493c50d8ae3SPaolo Bonzini * 49402844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 49502844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 49602844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 497c50d8ae3SPaolo Bonzini * 498c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 499c50d8ae3SPaolo Bonzini */ 500c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 501c50d8ae3SPaolo Bonzini { 502c50d8ae3SPaolo Bonzini bool flush = false; 503c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 504c50d8ae3SPaolo Bonzini 505c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 506c50d8ae3SPaolo Bonzini return false; 507c50d8ae3SPaolo Bonzini 508c50d8ae3SPaolo Bonzini /* 509c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 510c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 511c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 512c50d8ae3SPaolo Bonzini */ 513706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 514c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 515c50d8ae3SPaolo Bonzini flush = true; 516c50d8ae3SPaolo Bonzini 517c50d8ae3SPaolo Bonzini /* 518c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 519c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 520c50d8ae3SPaolo Bonzini */ 521c50d8ae3SPaolo Bonzini 522c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 523c50d8ae3SPaolo Bonzini flush = true; 524c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 525c50d8ae3SPaolo Bonzini } 526c50d8ae3SPaolo Bonzini 527c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 528c50d8ae3SPaolo Bonzini flush = true; 529c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 530c50d8ae3SPaolo Bonzini } 531c50d8ae3SPaolo Bonzini 532c50d8ae3SPaolo Bonzini return flush; 533c50d8ae3SPaolo Bonzini } 534c50d8ae3SPaolo Bonzini 535c50d8ae3SPaolo Bonzini /* 536c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 537c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 538c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5397fa2a347SSean Christopherson * Returns the old PTE. 540c50d8ae3SPaolo Bonzini */ 54135d539c3SSean Christopherson static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 542c50d8ae3SPaolo Bonzini { 543c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 544c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 54571f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 546b14b2690SSean Christopherson struct page *page; 547c50d8ae3SPaolo Bonzini 54854eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 54954eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 550c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 551c50d8ae3SPaolo Bonzini else 552c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 553c50d8ae3SPaolo Bonzini 554c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5557fa2a347SSean Christopherson return old_spte; 556c50d8ae3SPaolo Bonzini 55771f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 55871f51d2cSMingwei Zhang 559c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 560c50d8ae3SPaolo Bonzini 561c50d8ae3SPaolo Bonzini /* 562b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 563b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 564b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 565b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 566c50d8ae3SPaolo Bonzini */ 567b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 568b14b2690SSean Christopherson WARN_ON(page && !page_count(page)); 569c50d8ae3SPaolo Bonzini 570c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 571c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 572c50d8ae3SPaolo Bonzini 573c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 574c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 575c50d8ae3SPaolo Bonzini 5767fa2a347SSean Christopherson return old_spte; 577c50d8ae3SPaolo Bonzini } 578c50d8ae3SPaolo Bonzini 579c50d8ae3SPaolo Bonzini /* 580c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 581c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 582c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 583c50d8ae3SPaolo Bonzini */ 584c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 585c50d8ae3SPaolo Bonzini { 586c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 587c50d8ae3SPaolo Bonzini } 588c50d8ae3SPaolo Bonzini 589c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 590c50d8ae3SPaolo Bonzini { 591c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 592c50d8ae3SPaolo Bonzini } 593c50d8ae3SPaolo Bonzini 594c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 595c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 596c50d8ae3SPaolo Bonzini { 597c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 598c50d8ae3SPaolo Bonzini 599c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 600c50d8ae3SPaolo Bonzini return false; 601c50d8ae3SPaolo Bonzini 602c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 603c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 604c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 605c50d8ae3SPaolo Bonzini } else { 606c50d8ae3SPaolo Bonzini /* 607c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 608c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 609c50d8ae3SPaolo Bonzini */ 610c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 611c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 612c50d8ae3SPaolo Bonzini 613c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 614c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 615c50d8ae3SPaolo Bonzini } 616c50d8ae3SPaolo Bonzini 617c50d8ae3SPaolo Bonzini return true; 618c50d8ae3SPaolo Bonzini } 619c50d8ae3SPaolo Bonzini 62078fdd2f0SSean Christopherson static inline bool is_tdp_mmu_active(struct kvm_vcpu *vcpu) 62178fdd2f0SSean Christopherson { 62278fdd2f0SSean Christopherson return tdp_mmu_enabled && vcpu->arch.mmu->root_role.direct; 62378fdd2f0SSean Christopherson } 62478fdd2f0SSean Christopherson 625c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 626c50d8ae3SPaolo Bonzini { 62778fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 628c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 629c5c8c7c5SDavid Matlack } else { 630c50d8ae3SPaolo Bonzini /* 631c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 632c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 633c50d8ae3SPaolo Bonzini */ 634c50d8ae3SPaolo Bonzini local_irq_disable(); 635c50d8ae3SPaolo Bonzini 636c50d8ae3SPaolo Bonzini /* 637c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 638c50d8ae3SPaolo Bonzini * to vcpu->mode. 639c50d8ae3SPaolo Bonzini */ 640c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 641c50d8ae3SPaolo Bonzini } 642c5c8c7c5SDavid Matlack } 643c50d8ae3SPaolo Bonzini 644c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 645c50d8ae3SPaolo Bonzini { 64678fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 647c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 648c5c8c7c5SDavid Matlack } else { 649c50d8ae3SPaolo Bonzini /* 650c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 651c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 652c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 653c50d8ae3SPaolo Bonzini */ 654c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 655c50d8ae3SPaolo Bonzini local_irq_enable(); 656c50d8ae3SPaolo Bonzini } 657c5c8c7c5SDavid Matlack } 658c50d8ae3SPaolo Bonzini 659378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 660c50d8ae3SPaolo Bonzini { 661c50d8ae3SPaolo Bonzini int r; 662c50d8ae3SPaolo Bonzini 663531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 66494ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 665531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 666c50d8ae3SPaolo Bonzini if (r) 667c50d8ae3SPaolo Bonzini return r; 66894ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 669171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 670171a90d7SSean Christopherson if (r) 671171a90d7SSean Christopherson return r; 672378f5cd6SSean Christopherson if (maybe_indirect) { 6736a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 674171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 675c50d8ae3SPaolo Bonzini if (r) 676c50d8ae3SPaolo Bonzini return r; 677378f5cd6SSean Christopherson } 67894ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 679531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 680c50d8ae3SPaolo Bonzini } 681c50d8ae3SPaolo Bonzini 682c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 683c50d8ae3SPaolo Bonzini { 68494ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 68594ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 6866a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 68794ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 688c50d8ae3SPaolo Bonzini } 689c50d8ae3SPaolo Bonzini 690c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 691c50d8ae3SPaolo Bonzini { 692c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 693c50d8ae3SPaolo Bonzini } 694c50d8ae3SPaolo Bonzini 6956a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 6966a97575dSDavid Matlack 697c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 698c50d8ae3SPaolo Bonzini { 69984e5ffd0SLai Jiangshan if (sp->role.passthrough) 70084e5ffd0SLai Jiangshan return sp->gfn; 70184e5ffd0SLai Jiangshan 702c50d8ae3SPaolo Bonzini if (!sp->role.direct) 7036a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 704c50d8ae3SPaolo Bonzini 7052ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 706c50d8ae3SPaolo Bonzini } 707c50d8ae3SPaolo Bonzini 7086a97575dSDavid Matlack /* 7096a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 7106a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 7116a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 7126a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 7136a97575dSDavid Matlack */ 7146a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 715c50d8ae3SPaolo Bonzini { 7166a97575dSDavid Matlack if (sp_has_gptes(sp)) 7176a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7186a97575dSDavid Matlack 7196a97575dSDavid Matlack /* 7206a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7216a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7226a97575dSDavid Matlack * permissions" are just ACC_ALL. 7236a97575dSDavid Matlack * 7246a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7256a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7266a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7276a97575dSDavid Matlack * page. 7286a97575dSDavid Matlack * 7296a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7306a97575dSDavid Matlack */ 7316a97575dSDavid Matlack return sp->role.access; 7326a97575dSDavid Matlack } 7336a97575dSDavid Matlack 73472ae5822SSean Christopherson static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, 73572ae5822SSean Christopherson gfn_t gfn, unsigned int access) 7366a97575dSDavid Matlack { 7376a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7386a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 73984e5ffd0SLai Jiangshan return; 74084e5ffd0SLai Jiangshan } 74184e5ffd0SLai Jiangshan 7426a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7436a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7446a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7456a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7466a97575dSDavid Matlack 7476a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7486a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7496a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7506a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 751c50d8ae3SPaolo Bonzini } 752c50d8ae3SPaolo Bonzini 75372ae5822SSean Christopherson static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, 75472ae5822SSean Christopherson unsigned int access) 7556a97575dSDavid Matlack { 7566a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7576a97575dSDavid Matlack 7586a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 759c50d8ae3SPaolo Bonzini } 760c50d8ae3SPaolo Bonzini 761c50d8ae3SPaolo Bonzini /* 762c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 763c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 764c50d8ae3SPaolo Bonzini */ 765c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7668ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 767c50d8ae3SPaolo Bonzini { 768c50d8ae3SPaolo Bonzini unsigned long idx; 769c50d8ae3SPaolo Bonzini 770c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 771c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 772c50d8ae3SPaolo Bonzini } 773c50d8ae3SPaolo Bonzini 774269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 775c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 776c50d8ae3SPaolo Bonzini { 777c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 778c50d8ae3SPaolo Bonzini int i; 779c50d8ae3SPaolo Bonzini 7803bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 781c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 782c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 783c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 784c50d8ae3SPaolo Bonzini } 785c50d8ae3SPaolo Bonzini } 786c50d8ae3SPaolo Bonzini 787269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 788c50d8ae3SPaolo Bonzini { 789c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 790c50d8ae3SPaolo Bonzini } 791c50d8ae3SPaolo Bonzini 792269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 793c50d8ae3SPaolo Bonzini { 794c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 795c50d8ae3SPaolo Bonzini } 796c50d8ae3SPaolo Bonzini 797c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 798c50d8ae3SPaolo Bonzini { 799c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 800c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 801c50d8ae3SPaolo Bonzini gfn_t gfn; 802c50d8ae3SPaolo Bonzini 803c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 804c50d8ae3SPaolo Bonzini gfn = sp->gfn; 805c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 806c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 807c50d8ae3SPaolo Bonzini 808c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8093bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 810c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 811c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 812c50d8ae3SPaolo Bonzini 813c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 814be911771SDavid Matlack 815be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 816be911771SDavid Matlack kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 817c50d8ae3SPaolo Bonzini } 818c50d8ae3SPaolo Bonzini 81961f94478SSean Christopherson void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 820c50d8ae3SPaolo Bonzini { 821428e9216SSean Christopherson /* 822428e9216SSean Christopherson * If it's possible to replace the shadow page with an NX huge page, 823428e9216SSean Christopherson * i.e. if the shadow page is the only thing currently preventing KVM 824428e9216SSean Christopherson * from using a huge page, add the shadow page to the list of "to be 825428e9216SSean Christopherson * zapped for NX recovery" pages. Note, the shadow page can already be 826428e9216SSean Christopherson * on the list if KVM is reusing an existing shadow page, i.e. if KVM 827428e9216SSean Christopherson * links a shadow page at multiple points. 828428e9216SSean Christopherson */ 82961f94478SSean Christopherson if (!list_empty(&sp->possible_nx_huge_page_link)) 830c50d8ae3SPaolo Bonzini return; 831c50d8ae3SPaolo Bonzini 832c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 83355c510e2SSean Christopherson list_add_tail(&sp->possible_nx_huge_page_link, 83455c510e2SSean Christopherson &kvm->arch.possible_nx_huge_pages); 835c50d8ae3SPaolo Bonzini } 836c50d8ae3SPaolo Bonzini 83761f94478SSean Christopherson static void account_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp, 83861f94478SSean Christopherson bool nx_huge_page_possible) 83961f94478SSean Christopherson { 84061f94478SSean Christopherson sp->nx_huge_page_disallowed = true; 84161f94478SSean Christopherson 84261f94478SSean Christopherson if (nx_huge_page_possible) 84361f94478SSean Christopherson track_possible_nx_huge_page(kvm, sp); 844c50d8ae3SPaolo Bonzini } 845c50d8ae3SPaolo Bonzini 846c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 847c50d8ae3SPaolo Bonzini { 848c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 849c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 850c50d8ae3SPaolo Bonzini gfn_t gfn; 851c50d8ae3SPaolo Bonzini 852c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 853c50d8ae3SPaolo Bonzini gfn = sp->gfn; 854c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 855c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8563bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 857c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 858c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 859c50d8ae3SPaolo Bonzini 860c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 861c50d8ae3SPaolo Bonzini } 862c50d8ae3SPaolo Bonzini 86361f94478SSean Christopherson void untrack_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 864c50d8ae3SPaolo Bonzini { 86555c510e2SSean Christopherson if (list_empty(&sp->possible_nx_huge_page_link)) 866428e9216SSean Christopherson return; 867428e9216SSean Christopherson 868c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 86955c510e2SSean Christopherson list_del_init(&sp->possible_nx_huge_page_link); 870c50d8ae3SPaolo Bonzini } 871c50d8ae3SPaolo Bonzini 87261f94478SSean Christopherson static void unaccount_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 87361f94478SSean Christopherson { 87461f94478SSean Christopherson sp->nx_huge_page_disallowed = false; 87561f94478SSean Christopherson 87661f94478SSean Christopherson untrack_possible_nx_huge_page(kvm, sp); 877c50d8ae3SPaolo Bonzini } 878c50d8ae3SPaolo Bonzini 879c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 880c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 881c50d8ae3SPaolo Bonzini bool no_dirty_log) 882c50d8ae3SPaolo Bonzini { 883c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 884c50d8ae3SPaolo Bonzini 885c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 88691b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 88791b0d268SPaolo Bonzini return NULL; 888044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 88991b0d268SPaolo Bonzini return NULL; 890c50d8ae3SPaolo Bonzini 891c50d8ae3SPaolo Bonzini return slot; 892c50d8ae3SPaolo Bonzini } 893c50d8ae3SPaolo Bonzini 894c50d8ae3SPaolo Bonzini /* 895c50d8ae3SPaolo Bonzini * About rmap_head encoding: 896c50d8ae3SPaolo Bonzini * 897c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 898c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 899c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 900c50d8ae3SPaolo Bonzini */ 901c50d8ae3SPaolo Bonzini 902c50d8ae3SPaolo Bonzini /* 903c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 904c50d8ae3SPaolo Bonzini */ 9052ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 906c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 907c50d8ae3SPaolo Bonzini { 908c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 90913236e25SPeter Xu int count = 0; 910c50d8ae3SPaolo Bonzini 911c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 912805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 913c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 914c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 915805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 9162ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 917c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 918c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 91913236e25SPeter Xu desc->spte_count = 2; 920c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 921c50d8ae3SPaolo Bonzini ++count; 922c50d8ae3SPaolo Bonzini } else { 923805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 924c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 92513236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 926c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 927c6c4f961SLi RongQing if (!desc->more) { 9282ff9039aSDavid Matlack desc->more = kvm_mmu_memory_cache_alloc(cache); 929c50d8ae3SPaolo Bonzini desc = desc->more; 93013236e25SPeter Xu desc->spte_count = 0; 931c6c4f961SLi RongQing break; 932c6c4f961SLi RongQing } 933c6c4f961SLi RongQing desc = desc->more; 934c50d8ae3SPaolo Bonzini } 93513236e25SPeter Xu count += desc->spte_count; 93613236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 937c50d8ae3SPaolo Bonzini } 938c50d8ae3SPaolo Bonzini return count; 939c50d8ae3SPaolo Bonzini } 940c50d8ae3SPaolo Bonzini 941c50d8ae3SPaolo Bonzini static void 942c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 943c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 944c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 945c50d8ae3SPaolo Bonzini { 94613236e25SPeter Xu int j = desc->spte_count - 1; 947c50d8ae3SPaolo Bonzini 948c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 949c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 95013236e25SPeter Xu desc->spte_count--; 95113236e25SPeter Xu if (desc->spte_count) 952c50d8ae3SPaolo Bonzini return; 953c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 954fe3c2b4cSMiaohe Lin rmap_head->val = 0; 955c50d8ae3SPaolo Bonzini else 956c50d8ae3SPaolo Bonzini if (prev_desc) 957c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 958c50d8ae3SPaolo Bonzini else 959c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 960c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 961c50d8ae3SPaolo Bonzini } 962c50d8ae3SPaolo Bonzini 9633c2e1037SSean Christopherson static void pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 964c50d8ae3SPaolo Bonzini { 965c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 966c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 967c50d8ae3SPaolo Bonzini int i; 968c50d8ae3SPaolo Bonzini 969c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 970c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 971c50d8ae3SPaolo Bonzini BUG(); 972c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 973805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 974c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 975c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 976c50d8ae3SPaolo Bonzini BUG(); 977c50d8ae3SPaolo Bonzini } 978c50d8ae3SPaolo Bonzini rmap_head->val = 0; 979c50d8ae3SPaolo Bonzini } else { 980805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 981c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 982c50d8ae3SPaolo Bonzini prev_desc = NULL; 983c50d8ae3SPaolo Bonzini while (desc) { 98413236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 985c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 986c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 987c50d8ae3SPaolo Bonzini desc, i, prev_desc); 988c50d8ae3SPaolo Bonzini return; 989c50d8ae3SPaolo Bonzini } 990c50d8ae3SPaolo Bonzini } 991c50d8ae3SPaolo Bonzini prev_desc = desc; 992c50d8ae3SPaolo Bonzini desc = desc->more; 993c50d8ae3SPaolo Bonzini } 994c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 995c50d8ae3SPaolo Bonzini BUG(); 996c50d8ae3SPaolo Bonzini } 997c50d8ae3SPaolo Bonzini } 998c50d8ae3SPaolo Bonzini 9999202aee8SSean Christopherson static void kvm_zap_one_rmap_spte(struct kvm *kvm, 10009202aee8SSean Christopherson struct kvm_rmap_head *rmap_head, u64 *sptep) 1001c50d8ae3SPaolo Bonzini { 100271f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 10033c2e1037SSean Christopherson pte_list_remove(sptep, rmap_head); 1004c50d8ae3SPaolo Bonzini } 1005c50d8ae3SPaolo Bonzini 10069202aee8SSean Christopherson /* Return true if at least one SPTE was zapped, false otherwise */ 10079202aee8SSean Christopherson static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 10089202aee8SSean Christopherson struct kvm_rmap_head *rmap_head) 1009a75b5404SPeter Xu { 1010a75b5404SPeter Xu struct pte_list_desc *desc, *next; 1011a75b5404SPeter Xu int i; 1012a75b5404SPeter Xu 1013a75b5404SPeter Xu if (!rmap_head->val) 1014a75b5404SPeter Xu return false; 1015a75b5404SPeter Xu 1016a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 101771f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 1018a75b5404SPeter Xu goto out; 1019a75b5404SPeter Xu } 1020a75b5404SPeter Xu 1021a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1022a75b5404SPeter Xu 1023a75b5404SPeter Xu for (; desc; desc = next) { 1024a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 102571f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 1026a75b5404SPeter Xu next = desc->more; 1027a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 1028a75b5404SPeter Xu } 1029a75b5404SPeter Xu out: 1030a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 1031a75b5404SPeter Xu rmap_head->val = 0; 1032a75b5404SPeter Xu return true; 1033a75b5404SPeter Xu } 1034a75b5404SPeter Xu 10353bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10363bcd0662SPeter Xu { 10373bcd0662SPeter Xu struct pte_list_desc *desc; 10383bcd0662SPeter Xu unsigned int count = 0; 10393bcd0662SPeter Xu 10403bcd0662SPeter Xu if (!rmap_head->val) 10413bcd0662SPeter Xu return 0; 10423bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10433bcd0662SPeter Xu return 1; 10443bcd0662SPeter Xu 10453bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10463bcd0662SPeter Xu 10473bcd0662SPeter Xu while (desc) { 10483bcd0662SPeter Xu count += desc->spte_count; 10493bcd0662SPeter Xu desc = desc->more; 10503bcd0662SPeter Xu } 10513bcd0662SPeter Xu 10523bcd0662SPeter Xu return count; 10533bcd0662SPeter Xu } 10543bcd0662SPeter Xu 105593e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1056269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1057c50d8ae3SPaolo Bonzini { 1058c50d8ae3SPaolo Bonzini unsigned long idx; 1059c50d8ae3SPaolo Bonzini 1060c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10613bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1062c50d8ae3SPaolo Bonzini } 1063c50d8ae3SPaolo Bonzini 1064c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1065c50d8ae3SPaolo Bonzini { 1066356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1067c50d8ae3SPaolo Bonzini 1068356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 106994ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1070c50d8ae3SPaolo Bonzini } 1071c50d8ae3SPaolo Bonzini 1072c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1073c50d8ae3SPaolo Bonzini { 1074601f8af0SDavid Matlack struct kvm_memslots *slots; 1075601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1076c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1077c50d8ae3SPaolo Bonzini gfn_t gfn; 1078c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1079c50d8ae3SPaolo Bonzini 108057354682SSean Christopherson sp = sptep_to_sp(spte); 108179e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(spte)); 1082601f8af0SDavid Matlack 1083601f8af0SDavid Matlack /* 108468be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 108568be1306SDavid Matlack * so we have to determine which memslots to use based on context 108668be1306SDavid Matlack * information in sp->role. 1087601f8af0SDavid Matlack */ 1088601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1089601f8af0SDavid Matlack 1090601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 109193e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1092601f8af0SDavid Matlack 10933c2e1037SSean Christopherson pte_list_remove(spte, rmap_head); 1094c50d8ae3SPaolo Bonzini } 1095c50d8ae3SPaolo Bonzini 1096c50d8ae3SPaolo Bonzini /* 1097c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1098c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1099c50d8ae3SPaolo Bonzini */ 1100c50d8ae3SPaolo Bonzini struct rmap_iterator { 1101c50d8ae3SPaolo Bonzini /* private fields */ 1102c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1103c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1104c50d8ae3SPaolo Bonzini }; 1105c50d8ae3SPaolo Bonzini 1106c50d8ae3SPaolo Bonzini /* 1107c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1108c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 11090a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1110c50d8ae3SPaolo Bonzini * 1111c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1112c50d8ae3SPaolo Bonzini */ 1113c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1114c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1115c50d8ae3SPaolo Bonzini { 1116c50d8ae3SPaolo Bonzini u64 *sptep; 1117c50d8ae3SPaolo Bonzini 1118c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1119c50d8ae3SPaolo Bonzini return NULL; 1120c50d8ae3SPaolo Bonzini 1121c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1122c50d8ae3SPaolo Bonzini iter->desc = NULL; 1123c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1124c50d8ae3SPaolo Bonzini goto out; 1125c50d8ae3SPaolo Bonzini } 1126c50d8ae3SPaolo Bonzini 1127c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1128c50d8ae3SPaolo Bonzini iter->pos = 0; 1129c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1130c50d8ae3SPaolo Bonzini out: 1131c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1132c50d8ae3SPaolo Bonzini return sptep; 1133c50d8ae3SPaolo Bonzini } 1134c50d8ae3SPaolo Bonzini 1135c50d8ae3SPaolo Bonzini /* 1136c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1137c50d8ae3SPaolo Bonzini * 1138c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1139c50d8ae3SPaolo Bonzini */ 1140c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1141c50d8ae3SPaolo Bonzini { 1142c50d8ae3SPaolo Bonzini u64 *sptep; 1143c50d8ae3SPaolo Bonzini 1144c50d8ae3SPaolo Bonzini if (iter->desc) { 1145c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1146c50d8ae3SPaolo Bonzini ++iter->pos; 1147c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1148c50d8ae3SPaolo Bonzini if (sptep) 1149c50d8ae3SPaolo Bonzini goto out; 1150c50d8ae3SPaolo Bonzini } 1151c50d8ae3SPaolo Bonzini 1152c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1153c50d8ae3SPaolo Bonzini 1154c50d8ae3SPaolo Bonzini if (iter->desc) { 1155c50d8ae3SPaolo Bonzini iter->pos = 0; 1156c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1157c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1158c50d8ae3SPaolo Bonzini goto out; 1159c50d8ae3SPaolo Bonzini } 1160c50d8ae3SPaolo Bonzini } 1161c50d8ae3SPaolo Bonzini 1162c50d8ae3SPaolo Bonzini return NULL; 1163c50d8ae3SPaolo Bonzini out: 1164c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1165c50d8ae3SPaolo Bonzini return sptep; 1166c50d8ae3SPaolo Bonzini } 1167c50d8ae3SPaolo Bonzini 1168c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1169c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1170c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1171c50d8ae3SPaolo Bonzini 1172c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1173c50d8ae3SPaolo Bonzini { 117471f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11757fa2a347SSean Christopherson 11767fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1177c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1178c50d8ae3SPaolo Bonzini } 1179c50d8ae3SPaolo Bonzini 118003787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1181c50d8ae3SPaolo Bonzini { 11820cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 11830cd8dc73SPaolo Bonzini 11840cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 11850cd8dc73SPaolo Bonzini WARN_ON(sp->role.level == PG_LEVEL_4K); 11860cd8dc73SPaolo Bonzini 1187c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 118803787394SPaolo Bonzini 118903787394SPaolo Bonzini if (flush) 11900cd8dc73SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 1191c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1192c50d8ae3SPaolo Bonzini } 1193c50d8ae3SPaolo Bonzini 1194c50d8ae3SPaolo Bonzini /* 1195c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1196c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1197c50d8ae3SPaolo Bonzini * 1198c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1199c50d8ae3SPaolo Bonzini * protection: 1200c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1201c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1202c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1203c50d8ae3SPaolo Bonzini * shadow page. 1204c50d8ae3SPaolo Bonzini * 1205c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1206c50d8ae3SPaolo Bonzini */ 1207c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1208c50d8ae3SPaolo Bonzini { 1209c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1210c50d8ae3SPaolo Bonzini 1211c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1212706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1213c50d8ae3SPaolo Bonzini return false; 1214c50d8ae3SPaolo Bonzini 1215805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1216c50d8ae3SPaolo Bonzini 1217c50d8ae3SPaolo Bonzini if (pt_protect) 12185fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1219c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1220c50d8ae3SPaolo Bonzini 1221c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1222c50d8ae3SPaolo Bonzini } 1223c50d8ae3SPaolo Bonzini 12241346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1225c50d8ae3SPaolo Bonzini bool pt_protect) 1226c50d8ae3SPaolo Bonzini { 1227c50d8ae3SPaolo Bonzini u64 *sptep; 1228c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1229c50d8ae3SPaolo Bonzini bool flush = false; 1230c50d8ae3SPaolo Bonzini 1231c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1232c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1233c50d8ae3SPaolo Bonzini 1234c50d8ae3SPaolo Bonzini return flush; 1235c50d8ae3SPaolo Bonzini } 1236c50d8ae3SPaolo Bonzini 1237c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1238c50d8ae3SPaolo Bonzini { 1239c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1240c50d8ae3SPaolo Bonzini 1241805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1242c50d8ae3SPaolo Bonzini 1243c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1244c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1245c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1246c50d8ae3SPaolo Bonzini } 1247c50d8ae3SPaolo Bonzini 1248c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1249c50d8ae3SPaolo Bonzini { 1250c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1251c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1252c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1253c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1254c50d8ae3SPaolo Bonzini 1255c50d8ae3SPaolo Bonzini return was_writable; 1256c50d8ae3SPaolo Bonzini } 1257c50d8ae3SPaolo Bonzini 1258c50d8ae3SPaolo Bonzini /* 1259c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1260c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1261c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1262c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1263c50d8ae3SPaolo Bonzini */ 12640a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1265269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1266c50d8ae3SPaolo Bonzini { 1267c50d8ae3SPaolo Bonzini u64 *sptep; 1268c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1269c50d8ae3SPaolo Bonzini bool flush = false; 1270c50d8ae3SPaolo Bonzini 1271c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1272c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1273c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1274c50d8ae3SPaolo Bonzini else 1275c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1276c50d8ae3SPaolo Bonzini 1277c50d8ae3SPaolo Bonzini return flush; 1278c50d8ae3SPaolo Bonzini } 1279c50d8ae3SPaolo Bonzini 1280c50d8ae3SPaolo Bonzini /** 1281c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1282c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1283c50d8ae3SPaolo Bonzini * @slot: slot to protect 1284c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1285c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1286c50d8ae3SPaolo Bonzini * 128789212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1288c50d8ae3SPaolo Bonzini */ 1289c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1290c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1291c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1292c50d8ae3SPaolo Bonzini { 1293c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1294c50d8ae3SPaolo Bonzini 12951f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1296a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1297a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1298e2209710SBen Gardon 1299e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1300e2209710SBen Gardon return; 1301e2209710SBen Gardon 1302c50d8ae3SPaolo Bonzini while (mask) { 130393e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13043bae0459SSean Christopherson PG_LEVEL_4K, slot); 13051346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1306c50d8ae3SPaolo Bonzini 1307c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1308c50d8ae3SPaolo Bonzini mask &= mask - 1; 1309c50d8ae3SPaolo Bonzini } 1310c50d8ae3SPaolo Bonzini } 1311c50d8ae3SPaolo Bonzini 1312c50d8ae3SPaolo Bonzini /** 1313c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1314c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1315c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1316c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1317c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1318c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1319c50d8ae3SPaolo Bonzini * 1320c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1321c50d8ae3SPaolo Bonzini */ 1322a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1323c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1324c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1325c50d8ae3SPaolo Bonzini { 1326c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1327c50d8ae3SPaolo Bonzini 13281f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1329a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1330a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1331e2209710SBen Gardon 1332e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1333e2209710SBen Gardon return; 1334e2209710SBen Gardon 1335c50d8ae3SPaolo Bonzini while (mask) { 133693e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13373bae0459SSean Christopherson PG_LEVEL_4K, slot); 13380a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1339c50d8ae3SPaolo Bonzini 1340c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1341c50d8ae3SPaolo Bonzini mask &= mask - 1; 1342c50d8ae3SPaolo Bonzini } 1343c50d8ae3SPaolo Bonzini } 1344c50d8ae3SPaolo Bonzini 1345c50d8ae3SPaolo Bonzini /** 1346c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1347c50d8ae3SPaolo Bonzini * PT level pages. 1348c50d8ae3SPaolo Bonzini * 1349c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1350c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1351c50d8ae3SPaolo Bonzini * 135289212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 135389212919SKeqian Zhu * have such mappings. 1354c50d8ae3SPaolo Bonzini */ 1355c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1356c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1357c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1358c50d8ae3SPaolo Bonzini { 135989212919SKeqian Zhu /* 136089212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 136189212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 136289212919SKeqian Zhu * are split to 4K on the first write. 136389212919SKeqian Zhu * 136489212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 136589212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 136689212919SKeqian Zhu * pages. 136789212919SKeqian Zhu */ 136889212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 136989212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 137089212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 137189212919SKeqian Zhu 1372cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1373cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1374cb00a70bSDavid Matlack 137589212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 137689212919SKeqian Zhu 137789212919SKeqian Zhu /* Cross two large pages? */ 137889212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 137989212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 138089212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 138189212919SKeqian Zhu PG_LEVEL_2M); 138289212919SKeqian Zhu } 138389212919SKeqian Zhu 138489212919SKeqian Zhu /* Now handle 4K PTEs. */ 1385a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1386a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1387c50d8ae3SPaolo Bonzini else 1388c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1389c50d8ae3SPaolo Bonzini } 1390c50d8ae3SPaolo Bonzini 1391fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1392fb04a1edSPeter Xu { 13936dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1394fb04a1edSPeter Xu } 1395fb04a1edSPeter Xu 1396c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13973ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13983ad93562SKeqian Zhu int min_level) 1399c50d8ae3SPaolo Bonzini { 1400c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1401c50d8ae3SPaolo Bonzini int i; 1402c50d8ae3SPaolo Bonzini bool write_protected = false; 1403c50d8ae3SPaolo Bonzini 1404e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 14053ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 140693e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 14071346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1408c50d8ae3SPaolo Bonzini } 1409e2209710SBen Gardon } 1410c50d8ae3SPaolo Bonzini 14111f98f2bdSDavid Matlack if (tdp_mmu_enabled) 141246044f72SBen Gardon write_protected |= 14133ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 141446044f72SBen Gardon 1415c50d8ae3SPaolo Bonzini return write_protected; 1416c50d8ae3SPaolo Bonzini } 1417c50d8ae3SPaolo Bonzini 1418cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1419c50d8ae3SPaolo Bonzini { 1420c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1421c50d8ae3SPaolo Bonzini 1422c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 14233ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1424c50d8ae3SPaolo Bonzini } 1425c50d8ae3SPaolo Bonzini 1426f8480721SSean Christopherson static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1427269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1428c50d8ae3SPaolo Bonzini { 14299202aee8SSean Christopherson return kvm_zap_all_rmap_sptes(kvm, rmap_head); 1430c50d8ae3SPaolo Bonzini } 1431c50d8ae3SPaolo Bonzini 1432f8480721SSean Christopherson static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1433c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14343039bcc7SSean Christopherson pte_t unused) 1435c50d8ae3SPaolo Bonzini { 1436f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1437c50d8ae3SPaolo Bonzini } 1438c50d8ae3SPaolo Bonzini 1439aed02fe3SSean Christopherson static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1440c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14413039bcc7SSean Christopherson pte_t pte) 1442c50d8ae3SPaolo Bonzini { 1443c50d8ae3SPaolo Bonzini u64 *sptep; 1444c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 144598a26b69SVihas Mak bool need_flush = false; 1446c50d8ae3SPaolo Bonzini u64 new_spte; 1447c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1448c50d8ae3SPaolo Bonzini 14493039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14503039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1451c50d8ae3SPaolo Bonzini 1452c50d8ae3SPaolo Bonzini restart: 1453c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1454805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1455c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1456c50d8ae3SPaolo Bonzini 145798a26b69SVihas Mak need_flush = true; 1458c50d8ae3SPaolo Bonzini 14593039bcc7SSean Christopherson if (pte_write(pte)) { 14609202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 1461c50d8ae3SPaolo Bonzini goto restart; 1462c50d8ae3SPaolo Bonzini } else { 1463cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1464cb3eedabSPaolo Bonzini *sptep, new_pfn); 1465c50d8ae3SPaolo Bonzini 146671f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1467c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1468c50d8ae3SPaolo Bonzini } 1469c50d8ae3SPaolo Bonzini } 1470c50d8ae3SPaolo Bonzini 1471c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1472c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 147398a26b69SVihas Mak return false; 1474c50d8ae3SPaolo Bonzini } 1475c50d8ae3SPaolo Bonzini 1476c50d8ae3SPaolo Bonzini return need_flush; 1477c50d8ae3SPaolo Bonzini } 1478c50d8ae3SPaolo Bonzini 1479c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1480c50d8ae3SPaolo Bonzini /* input fields. */ 1481269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1482c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1483c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1484c50d8ae3SPaolo Bonzini int start_level; 1485c50d8ae3SPaolo Bonzini int end_level; 1486c50d8ae3SPaolo Bonzini 1487c50d8ae3SPaolo Bonzini /* output fields. */ 1488c50d8ae3SPaolo Bonzini gfn_t gfn; 1489c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1490c50d8ae3SPaolo Bonzini int level; 1491c50d8ae3SPaolo Bonzini 1492c50d8ae3SPaolo Bonzini /* private field. */ 1493c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1494c50d8ae3SPaolo Bonzini }; 1495c50d8ae3SPaolo Bonzini 1496c50d8ae3SPaolo Bonzini static void 1497c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1498c50d8ae3SPaolo Bonzini { 1499c50d8ae3SPaolo Bonzini iterator->level = level; 1500c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 150193e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 150293e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1503c50d8ae3SPaolo Bonzini } 1504c50d8ae3SPaolo Bonzini 1505c50d8ae3SPaolo Bonzini static void 1506c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1507269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1508c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1509c50d8ae3SPaolo Bonzini { 1510c50d8ae3SPaolo Bonzini iterator->slot = slot; 1511c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1512c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1513c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1514c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1515c50d8ae3SPaolo Bonzini 1516c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1517c50d8ae3SPaolo Bonzini } 1518c50d8ae3SPaolo Bonzini 1519c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1520c50d8ae3SPaolo Bonzini { 1521c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1522c50d8ae3SPaolo Bonzini } 1523c50d8ae3SPaolo Bonzini 1524c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1525c50d8ae3SPaolo Bonzini { 15266ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1527c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 15286ba1e04fSVipin Sharma 15296ba1e04fSVipin Sharma if (iterator->rmap->val) 1530c50d8ae3SPaolo Bonzini return; 1531c50d8ae3SPaolo Bonzini } 1532c50d8ae3SPaolo Bonzini 1533c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1534c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1535c50d8ae3SPaolo Bonzini return; 1536c50d8ae3SPaolo Bonzini } 1537c50d8ae3SPaolo Bonzini 1538c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1539c50d8ae3SPaolo Bonzini } 1540c50d8ae3SPaolo Bonzini 1541c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1542c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1543c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1544c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1545c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1546c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1547c50d8ae3SPaolo Bonzini 15483039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1549c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15503039bcc7SSean Christopherson int level, pte_t pte); 1551c1b91493SSean Christopherson 15523039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15533039bcc7SSean Christopherson struct kvm_gfn_range *range, 1554c1b91493SSean Christopherson rmap_handler_t handler) 1555c50d8ae3SPaolo Bonzini { 1556c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15573039bcc7SSean Christopherson bool ret = false; 1558c50d8ae3SPaolo Bonzini 15593039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15603039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15613039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15623039bcc7SSean Christopherson iterator.level, range->pte); 1563c50d8ae3SPaolo Bonzini 1564c50d8ae3SPaolo Bonzini return ret; 1565c50d8ae3SPaolo Bonzini } 1566c50d8ae3SPaolo Bonzini 15673039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1568c50d8ae3SPaolo Bonzini { 1569e2209710SBen Gardon bool flush = false; 1570c50d8ae3SPaolo Bonzini 1571e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1572f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1573063afacdSBen Gardon 15741f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1575c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1576063afacdSBen Gardon 15773039bcc7SSean Christopherson return flush; 1578c50d8ae3SPaolo Bonzini } 1579c50d8ae3SPaolo Bonzini 15803039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1581c50d8ae3SPaolo Bonzini { 1582e2209710SBen Gardon bool flush = false; 15831d8dd6b3SBen Gardon 1584e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1585aed02fe3SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); 15861d8dd6b3SBen Gardon 15871f98f2bdSDavid Matlack if (tdp_mmu_enabled) 15883039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15891d8dd6b3SBen Gardon 15903039bcc7SSean Christopherson return flush; 1591c50d8ae3SPaolo Bonzini } 1592c50d8ae3SPaolo Bonzini 1593aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1594c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15953039bcc7SSean Christopherson pte_t unused) 1596c50d8ae3SPaolo Bonzini { 1597c50d8ae3SPaolo Bonzini u64 *sptep; 15983f649ab7SKees Cook struct rmap_iterator iter; 1599c50d8ae3SPaolo Bonzini int young = 0; 1600c50d8ae3SPaolo Bonzini 1601c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1602c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1603c50d8ae3SPaolo Bonzini 1604c50d8ae3SPaolo Bonzini return young; 1605c50d8ae3SPaolo Bonzini } 1606c50d8ae3SPaolo Bonzini 1607aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1608c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 16093039bcc7SSean Christopherson int level, pte_t unused) 1610c50d8ae3SPaolo Bonzini { 1611c50d8ae3SPaolo Bonzini u64 *sptep; 1612c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1613c50d8ae3SPaolo Bonzini 1614c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1615c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 161698a26b69SVihas Mak return true; 161798a26b69SVihas Mak return false; 1618c50d8ae3SPaolo Bonzini } 1619c50d8ae3SPaolo Bonzini 1620c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1621c50d8ae3SPaolo Bonzini 16222ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 16232ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 16242ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 162572ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1626c50d8ae3SPaolo Bonzini { 1627c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 162868be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 162968be1306SDavid Matlack int rmap_count; 1630c50d8ae3SPaolo Bonzini 163157354682SSean Christopherson sp = sptep_to_sp(spte); 163279e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 163381cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 163481cb4657SDavid Matlack 163593e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 16362ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1637c50d8ae3SPaolo Bonzini 1638604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1639604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 164068be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16419202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 164268be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 16432ff9039aSDavid Matlack kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 164468be1306SDavid Matlack } 1645c50d8ae3SPaolo Bonzini } 1646c50d8ae3SPaolo Bonzini 16472ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 164872ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16492ff9039aSDavid Matlack { 16502ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16512ff9039aSDavid Matlack 16526a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16532ff9039aSDavid Matlack } 16542ff9039aSDavid Matlack 16553039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1656c50d8ae3SPaolo Bonzini { 1657e2209710SBen Gardon bool young = false; 1658f8e14497SBen Gardon 1659e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1660aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16613039bcc7SSean Christopherson 16621f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16633039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1664f8e14497SBen Gardon 1665f8e14497SBen Gardon return young; 1666c50d8ae3SPaolo Bonzini } 1667c50d8ae3SPaolo Bonzini 16683039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1669c50d8ae3SPaolo Bonzini { 1670e2209710SBen Gardon bool young = false; 1671f8e14497SBen Gardon 1672e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1673aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 16743039bcc7SSean Christopherson 16751f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16763039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1677f8e14497SBen Gardon 1678f8e14497SBen Gardon return young; 1679c50d8ae3SPaolo Bonzini } 1680c50d8ae3SPaolo Bonzini 1681c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1682c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1683c50d8ae3SPaolo Bonzini { 1684c50d8ae3SPaolo Bonzini u64 *pos; 1685c50d8ae3SPaolo Bonzini u64 *end; 1686c50d8ae3SPaolo Bonzini 16873adbdf81SMiaohe Lin for (pos = spt, end = pos + SPTE_ENT_PER_PAGE; pos != end; pos++) 1688c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1689c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1690c50d8ae3SPaolo Bonzini pos, *pos); 1691c50d8ae3SPaolo Bonzini return 0; 1692c50d8ae3SPaolo Bonzini } 1693c50d8ae3SPaolo Bonzini return 1; 1694c50d8ae3SPaolo Bonzini } 1695c50d8ae3SPaolo Bonzini #endif 1696c50d8ae3SPaolo Bonzini 1697c50d8ae3SPaolo Bonzini /* 1698c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1699c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1700c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1701c50d8ae3SPaolo Bonzini * faster 1702c50d8ae3SPaolo Bonzini */ 1703d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1704c50d8ae3SPaolo Bonzini { 1705c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1706c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1707c50d8ae3SPaolo Bonzini } 1708c50d8ae3SPaolo Bonzini 170943a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 171043a063caSYosry Ahmed { 171143a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 171243a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 171343a063caSYosry Ahmed } 171443a063caSYosry Ahmed 171543a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 171643a063caSYosry Ahmed { 171743a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 171843a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 171943a063caSYosry Ahmed } 172043a063caSYosry Ahmed 172187654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1722c50d8ae3SPaolo Bonzini { 1723c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1724c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1725c50d8ae3SPaolo Bonzini list_del(&sp->link); 1726c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1727c50d8ae3SPaolo Bonzini if (!sp->role.direct) 17286a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1729c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1730c50d8ae3SPaolo Bonzini } 1731c50d8ae3SPaolo Bonzini 1732c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1733c50d8ae3SPaolo Bonzini { 1734c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1735c50d8ae3SPaolo Bonzini } 1736c50d8ae3SPaolo Bonzini 17372ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1738c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1739c50d8ae3SPaolo Bonzini { 1740c50d8ae3SPaolo Bonzini if (!parent_pte) 1741c50d8ae3SPaolo Bonzini return; 1742c50d8ae3SPaolo Bonzini 17432ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1744c50d8ae3SPaolo Bonzini } 1745c50d8ae3SPaolo Bonzini 1746c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1747c50d8ae3SPaolo Bonzini u64 *parent_pte) 1748c50d8ae3SPaolo Bonzini { 17493c2e1037SSean Christopherson pte_list_remove(parent_pte, &sp->parent_ptes); 1750c50d8ae3SPaolo Bonzini } 1751c50d8ae3SPaolo Bonzini 1752c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1753c50d8ae3SPaolo Bonzini u64 *parent_pte) 1754c50d8ae3SPaolo Bonzini { 1755c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1756c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1757c50d8ae3SPaolo Bonzini } 1758c50d8ae3SPaolo Bonzini 1759c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1760c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1761c50d8ae3SPaolo Bonzini { 1762c50d8ae3SPaolo Bonzini u64 *sptep; 1763c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1764c50d8ae3SPaolo Bonzini 1765c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1766c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1767c50d8ae3SPaolo Bonzini } 1768c50d8ae3SPaolo Bonzini } 1769c50d8ae3SPaolo Bonzini 1770c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1771c50d8ae3SPaolo Bonzini { 1772c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1773c50d8ae3SPaolo Bonzini 177457354682SSean Christopherson sp = sptep_to_sp(spte); 177579e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1776c50d8ae3SPaolo Bonzini return; 1777c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1778c50d8ae3SPaolo Bonzini return; 1779c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1780c50d8ae3SPaolo Bonzini } 1781c50d8ae3SPaolo Bonzini 1782c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1783c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1784c50d8ae3SPaolo Bonzini { 1785c3e5e415SLai Jiangshan return -1; 1786c50d8ae3SPaolo Bonzini } 1787c50d8ae3SPaolo Bonzini 1788c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1789c50d8ae3SPaolo Bonzini 1790c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1791c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1792c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1793c50d8ae3SPaolo Bonzini unsigned int idx; 1794c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1795c50d8ae3SPaolo Bonzini unsigned int nr; 1796c50d8ae3SPaolo Bonzini }; 1797c50d8ae3SPaolo Bonzini 1798c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1799c50d8ae3SPaolo Bonzini int idx) 1800c50d8ae3SPaolo Bonzini { 1801c50d8ae3SPaolo Bonzini int i; 1802c50d8ae3SPaolo Bonzini 1803c50d8ae3SPaolo Bonzini if (sp->unsync) 1804c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1805c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1806c50d8ae3SPaolo Bonzini return 0; 1807c50d8ae3SPaolo Bonzini 1808c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1809c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1810c50d8ae3SPaolo Bonzini pvec->nr++; 1811c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1812c50d8ae3SPaolo Bonzini } 1813c50d8ae3SPaolo Bonzini 1814c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1815c50d8ae3SPaolo Bonzini { 1816c50d8ae3SPaolo Bonzini --sp->unsync_children; 1817c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1818c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1819c50d8ae3SPaolo Bonzini } 1820c50d8ae3SPaolo Bonzini 1821c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1822c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1823c50d8ae3SPaolo Bonzini { 1824c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1825c50d8ae3SPaolo Bonzini 1826c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1827c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1828c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1829c50d8ae3SPaolo Bonzini 1830c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1831c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1832c50d8ae3SPaolo Bonzini continue; 1833c50d8ae3SPaolo Bonzini } 1834c50d8ae3SPaolo Bonzini 18355e3edd7eSSean Christopherson child = spte_to_child_sp(ent); 1836c50d8ae3SPaolo Bonzini 1837c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1838c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1839c50d8ae3SPaolo Bonzini return -ENOSPC; 1840c50d8ae3SPaolo Bonzini 1841c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1842c50d8ae3SPaolo Bonzini if (!ret) { 1843c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1844c50d8ae3SPaolo Bonzini continue; 1845c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1846c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1847c50d8ae3SPaolo Bonzini } else 1848c50d8ae3SPaolo Bonzini return ret; 1849c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1850c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1851c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1852c50d8ae3SPaolo Bonzini return -ENOSPC; 1853c50d8ae3SPaolo Bonzini } else 1854c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1855c50d8ae3SPaolo Bonzini } 1856c50d8ae3SPaolo Bonzini 1857c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1858c50d8ae3SPaolo Bonzini } 1859c50d8ae3SPaolo Bonzini 1860c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1861c50d8ae3SPaolo Bonzini 1862c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1863c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1864c50d8ae3SPaolo Bonzini { 1865c50d8ae3SPaolo Bonzini pvec->nr = 0; 1866c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1867c50d8ae3SPaolo Bonzini return 0; 1868c50d8ae3SPaolo Bonzini 1869c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1870c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1871c50d8ae3SPaolo Bonzini } 1872c50d8ae3SPaolo Bonzini 1873c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1874c50d8ae3SPaolo Bonzini { 1875c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1876c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1877c50d8ae3SPaolo Bonzini sp->unsync = 0; 1878c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1879c50d8ae3SPaolo Bonzini } 1880c50d8ae3SPaolo Bonzini 1881c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1882c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1883c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1884c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1885c50d8ae3SPaolo Bonzini 1886767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1887767d8d8dSLai Jiangshan { 1888767d8d8dSLai Jiangshan if (sp->role.direct) 1889767d8d8dSLai Jiangshan return false; 1890767d8d8dSLai Jiangshan 189184e5ffd0SLai Jiangshan if (sp->role.passthrough) 189284e5ffd0SLai Jiangshan return false; 189384e5ffd0SLai Jiangshan 1894767d8d8dSLai Jiangshan return true; 1895767d8d8dSLai Jiangshan } 1896767d8d8dSLai Jiangshan 1897ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1898ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1899c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1900c50d8ae3SPaolo Bonzini } else 1901c50d8ae3SPaolo Bonzini 1902767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1903ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1904ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1905767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1906c50d8ae3SPaolo Bonzini 19078d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1908c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1909c50d8ae3SPaolo Bonzini { 1910c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1911c3e5e415SLai Jiangshan 19128d5678a7SHou Wenlong if (ret < 0) 1913c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 19148d5678a7SHou Wenlong return ret; 1915c50d8ae3SPaolo Bonzini } 1916c50d8ae3SPaolo Bonzini 1917c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1918c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1919c50d8ae3SPaolo Bonzini bool remote_flush) 1920c50d8ae3SPaolo Bonzini { 1921c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1922c50d8ae3SPaolo Bonzini return false; 1923c50d8ae3SPaolo Bonzini 1924c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1925c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1926c50d8ae3SPaolo Bonzini else 1927c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1928c50d8ae3SPaolo Bonzini return true; 1929c50d8ae3SPaolo Bonzini } 1930c50d8ae3SPaolo Bonzini 1931c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1932c50d8ae3SPaolo Bonzini { 1933a955cad8SSean Christopherson if (sp->role.invalid) 1934a955cad8SSean Christopherson return true; 1935a955cad8SSean Christopherson 1936fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 1937de0322f5SSean Christopherson return !is_tdp_mmu_page(sp) && 1938c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1939c50d8ae3SPaolo Bonzini } 1940c50d8ae3SPaolo Bonzini 1941c50d8ae3SPaolo Bonzini struct mmu_page_path { 1942c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1943c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1944c50d8ae3SPaolo Bonzini }; 1945c50d8ae3SPaolo Bonzini 1946c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1947c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1948c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1949c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1950c50d8ae3SPaolo Bonzini 1951c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1952c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1953c50d8ae3SPaolo Bonzini int i) 1954c50d8ae3SPaolo Bonzini { 1955c50d8ae3SPaolo Bonzini int n; 1956c50d8ae3SPaolo Bonzini 1957c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1958c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1959c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1960c50d8ae3SPaolo Bonzini int level = sp->role.level; 1961c50d8ae3SPaolo Bonzini 1962c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19633bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1964c50d8ae3SPaolo Bonzini break; 1965c50d8ae3SPaolo Bonzini 1966c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1967c50d8ae3SPaolo Bonzini } 1968c50d8ae3SPaolo Bonzini 1969c50d8ae3SPaolo Bonzini return n; 1970c50d8ae3SPaolo Bonzini } 1971c50d8ae3SPaolo Bonzini 1972c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1973c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1974c50d8ae3SPaolo Bonzini { 1975c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1976c50d8ae3SPaolo Bonzini int level; 1977c50d8ae3SPaolo Bonzini 1978c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1979c50d8ae3SPaolo Bonzini return 0; 1980c50d8ae3SPaolo Bonzini 1981c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1982c50d8ae3SPaolo Bonzini 1983c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1984c50d8ae3SPaolo Bonzini level = sp->role.level; 19853bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1986c50d8ae3SPaolo Bonzini 1987c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1988c50d8ae3SPaolo Bonzini 1989c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1990c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1991c50d8ae3SPaolo Bonzini */ 1992c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1993c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1994c50d8ae3SPaolo Bonzini } 1995c50d8ae3SPaolo Bonzini 1996c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1997c50d8ae3SPaolo Bonzini { 1998c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1999c50d8ae3SPaolo Bonzini unsigned int level = 0; 2000c50d8ae3SPaolo Bonzini 2001c50d8ae3SPaolo Bonzini do { 2002c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 2003c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 2004c50d8ae3SPaolo Bonzini if (!sp) 2005c50d8ae3SPaolo Bonzini return; 2006c50d8ae3SPaolo Bonzini 2007c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 2008c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 2009c50d8ae3SPaolo Bonzini level++; 2010c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 2011c50d8ae3SPaolo Bonzini } 2012c50d8ae3SPaolo Bonzini 201365855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 201465855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 2015c50d8ae3SPaolo Bonzini { 2016c50d8ae3SPaolo Bonzini int i; 2017c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2018c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2019c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2020c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2021c50d8ae3SPaolo Bonzini bool flush = false; 2022c50d8ae3SPaolo Bonzini 2023c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2024c50d8ae3SPaolo Bonzini bool protected = false; 2025c50d8ae3SPaolo Bonzini 2026c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 2027cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 2028c50d8ae3SPaolo Bonzini 2029c50d8ae3SPaolo Bonzini if (protected) { 20305591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 2031c50d8ae3SPaolo Bonzini flush = false; 2032c50d8ae3SPaolo Bonzini } 2033c50d8ae3SPaolo Bonzini 2034c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2035479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 20368d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 2037c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2038c50d8ae3SPaolo Bonzini } 2039531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2040c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 204165855ed8SLai Jiangshan if (!can_yield) { 204265855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 204365855ed8SLai Jiangshan return -EINTR; 204465855ed8SLai Jiangshan } 204565855ed8SLai Jiangshan 2046531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2047c50d8ae3SPaolo Bonzini flush = false; 2048c50d8ae3SPaolo Bonzini } 2049c50d8ae3SPaolo Bonzini } 2050c50d8ae3SPaolo Bonzini 2051c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 205265855ed8SLai Jiangshan return 0; 2053c50d8ae3SPaolo Bonzini } 2054c50d8ae3SPaolo Bonzini 2055c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2056c50d8ae3SPaolo Bonzini { 2057c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2058c50d8ae3SPaolo Bonzini } 2059c50d8ae3SPaolo Bonzini 2060c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2061c50d8ae3SPaolo Bonzini { 206257354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2063c50d8ae3SPaolo Bonzini } 2064c50d8ae3SPaolo Bonzini 2065cbd858b1SDavid Matlack /* 2066cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2067cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2068cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2069cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2070cbd858b1SDavid Matlack */ 20713cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 20723cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 207394c81364SDavid Matlack gfn_t gfn, 207494c81364SDavid Matlack struct hlist_head *sp_list, 20752e65e842SDavid Matlack union kvm_mmu_page_role role) 2076c50d8ae3SPaolo Bonzini { 2077c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20788d5678a7SHou Wenlong int ret; 2079c50d8ae3SPaolo Bonzini int collisions = 0; 2080c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2081c50d8ae3SPaolo Bonzini 20823cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2083c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2084c50d8ae3SPaolo Bonzini collisions++; 2085c50d8ae3SPaolo Bonzini continue; 2086c50d8ae3SPaolo Bonzini } 2087c50d8ae3SPaolo Bonzini 2088ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2089ddc16abbSSean Christopherson /* 2090ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2091ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2092ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2093ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2094ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2095ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2096ddc16abbSSean Christopherson * upper-level page will be write-protected. 2097ddc16abbSSean Christopherson */ 20982e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 20993cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2100ddc16abbSSean Christopherson &invalid_list); 2101c50d8ae3SPaolo Bonzini continue; 2102ddc16abbSSean Christopherson } 2103c50d8ae3SPaolo Bonzini 2104bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2105bb924ca6SDavid Matlack if (sp->role.direct) 210694c81364SDavid Matlack goto out; 2107fb58a9c3SSean Christopherson 2108c50d8ae3SPaolo Bonzini if (sp->unsync) { 2109cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2110cbd858b1SDavid Matlack break; 2111cbd858b1SDavid Matlack 211207dc4f35SSean Christopherson /* 2113479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 211407dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 211507dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 211607dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 211707dc4f35SSean Christopherson * overhead of write protection is not incurred until the 211807dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 211907dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 212007dc4f35SSean Christopherson * 212107dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 212207dc4f35SSean Christopherson * in order to rebuild it. 2123c50d8ae3SPaolo Bonzini */ 21248d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 21258d5678a7SHou Wenlong if (ret < 0) 2126c50d8ae3SPaolo Bonzini break; 2127c50d8ae3SPaolo Bonzini 2128c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 21298d5678a7SHou Wenlong if (ret > 0) 21303cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2131c50d8ae3SPaolo Bonzini } 2132c50d8ae3SPaolo Bonzini 2133c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2134fb58a9c3SSean Christopherson 2135c50d8ae3SPaolo Bonzini goto out; 2136c50d8ae3SPaolo Bonzini } 2137c50d8ae3SPaolo Bonzini 213894c81364SDavid Matlack sp = NULL; 21393cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2140c50d8ae3SPaolo Bonzini 214194c81364SDavid Matlack out: 21423cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 214394c81364SDavid Matlack 21443cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 21453cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 214694c81364SDavid Matlack return sp; 214794c81364SDavid Matlack } 214894c81364SDavid Matlack 21492f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 21502f8b1b53SDavid Matlack struct shadow_page_caches { 21512f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 21522f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 21536a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 21542f8b1b53SDavid Matlack }; 21552f8b1b53SDavid Matlack 2156336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 21572f8b1b53SDavid Matlack struct shadow_page_caches *caches, 215894c81364SDavid Matlack gfn_t gfn, 215994c81364SDavid Matlack struct hlist_head *sp_list, 216094c81364SDavid Matlack union kvm_mmu_page_role role) 216194c81364SDavid Matlack { 2162c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2163c306aec8SDavid Matlack 21642f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 21652f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2166c306aec8SDavid Matlack if (!role.direct) 21676a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2168c306aec8SDavid Matlack 2169c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2170c306aec8SDavid Matlack 217155c510e2SSean Christopherson INIT_LIST_HEAD(&sp->possible_nx_huge_page_link); 2172428e9216SSean Christopherson 2173c306aec8SDavid Matlack /* 2174c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2175c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2176c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2177c306aec8SDavid Matlack */ 2178336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2179336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 218043a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2181c50d8ae3SPaolo Bonzini 2182c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2183c50d8ae3SPaolo Bonzini sp->role = role; 2184ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2185be911771SDavid Matlack if (sp_has_gptes(sp)) 2186336081fbSDavid Matlack account_shadowed(kvm, sp); 2187ddc16abbSSean Christopherson 218894c81364SDavid Matlack return sp; 218994c81364SDavid Matlack } 219094c81364SDavid Matlack 2191cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 21923cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 21933cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 21942f8b1b53SDavid Matlack struct shadow_page_caches *caches, 219587654643SDavid Matlack gfn_t gfn, 219694c81364SDavid Matlack union kvm_mmu_page_role role) 219794c81364SDavid Matlack { 219894c81364SDavid Matlack struct hlist_head *sp_list; 219994c81364SDavid Matlack struct kvm_mmu_page *sp; 220094c81364SDavid Matlack bool created = false; 220194c81364SDavid Matlack 22023cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 220394c81364SDavid Matlack 22043cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 220594c81364SDavid Matlack if (!sp) { 220694c81364SDavid Matlack created = true; 22073cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 220894c81364SDavid Matlack } 220994c81364SDavid Matlack 221094c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2211c50d8ae3SPaolo Bonzini return sp; 2212c50d8ae3SPaolo Bonzini } 2213c50d8ae3SPaolo Bonzini 22142f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 22152f8b1b53SDavid Matlack gfn_t gfn, 22162f8b1b53SDavid Matlack union kvm_mmu_page_role role) 22172f8b1b53SDavid Matlack { 22182f8b1b53SDavid Matlack struct shadow_page_caches caches = { 22192f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 22202f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 22216a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 22222f8b1b53SDavid Matlack }; 22232f8b1b53SDavid Matlack 22243cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 22252f8b1b53SDavid Matlack } 22262f8b1b53SDavid Matlack 222739944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 222839944ab9SSean Christopherson unsigned int access) 22292e65e842SDavid Matlack { 22302e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 22312e65e842SDavid Matlack union kvm_mmu_page_role role; 22322e65e842SDavid Matlack 22332e65e842SDavid Matlack role = parent_sp->role; 22342e65e842SDavid Matlack role.level--; 22352e65e842SDavid Matlack role.access = access; 22362e65e842SDavid Matlack role.direct = direct; 22372e65e842SDavid Matlack role.passthrough = 0; 22382e65e842SDavid Matlack 22392e65e842SDavid Matlack /* 22402e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 22412e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 22422e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 22432e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 22442e65e842SDavid Matlack * requires extra bookkeeping in the role. 22452e65e842SDavid Matlack * 22462e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 22472e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 22482e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 22492e65e842SDavid Matlack * the address space each maps. 22502e65e842SDavid Matlack * 22512e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 22522e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 22532e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 22542e65e842SDavid Matlack * 225539944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 225639944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 225739944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 225839944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 225939944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 226039944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 226139944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 226239944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 226339944ab9SSean Christopherson * _least_ significant bit of the PDE index. 22642e65e842SDavid Matlack */ 22652e65e842SDavid Matlack if (role.has_4_byte_gpte) { 22662e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 226779e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 22682e65e842SDavid Matlack } 22692e65e842SDavid Matlack 22702e65e842SDavid Matlack return role; 22712e65e842SDavid Matlack } 22722e65e842SDavid Matlack 22732e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 22742e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 22752e65e842SDavid Matlack bool direct, unsigned int access) 22762e65e842SDavid Matlack { 22772e65e842SDavid Matlack union kvm_mmu_page_role role; 22782e65e842SDavid Matlack 22790cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 22800cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 22810cd8dc73SPaolo Bonzini 22822e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 228387654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 22842e65e842SDavid Matlack } 22852e65e842SDavid Matlack 2286c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2287c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2288c50d8ae3SPaolo Bonzini u64 addr) 2289c50d8ae3SPaolo Bonzini { 2290c50d8ae3SPaolo Bonzini iterator->addr = addr; 2291c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2292a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2293c50d8ae3SPaolo Bonzini 229412ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 22954d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2296347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 229712ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2298c50d8ae3SPaolo Bonzini 2299c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2300c50d8ae3SPaolo Bonzini /* 2301c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2302c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2303c50d8ae3SPaolo Bonzini */ 2304b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2305c50d8ae3SPaolo Bonzini 2306c50d8ae3SPaolo Bonzini iterator->shadow_addr 2307c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 23082ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2309c50d8ae3SPaolo Bonzini --iterator->level; 2310c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2311c50d8ae3SPaolo Bonzini iterator->level = 0; 2312c50d8ae3SPaolo Bonzini } 2313c50d8ae3SPaolo Bonzini } 2314c50d8ae3SPaolo Bonzini 2315c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2316c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2317c50d8ae3SPaolo Bonzini { 2318b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2319c50d8ae3SPaolo Bonzini addr); 2320c50d8ae3SPaolo Bonzini } 2321c50d8ae3SPaolo Bonzini 2322c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2323c50d8ae3SPaolo Bonzini { 23243bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2325c50d8ae3SPaolo Bonzini return false; 2326c50d8ae3SPaolo Bonzini 23272ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2328c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2329c50d8ae3SPaolo Bonzini return true; 2330c50d8ae3SPaolo Bonzini } 2331c50d8ae3SPaolo Bonzini 2332c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2333c50d8ae3SPaolo Bonzini u64 spte) 2334c50d8ae3SPaolo Bonzini { 23353e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2336c50d8ae3SPaolo Bonzini iterator->level = 0; 2337c50d8ae3SPaolo Bonzini return; 2338c50d8ae3SPaolo Bonzini } 2339c50d8ae3SPaolo Bonzini 23402ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2341c50d8ae3SPaolo Bonzini --iterator->level; 2342c50d8ae3SPaolo Bonzini } 2343c50d8ae3SPaolo Bonzini 2344c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2345c50d8ae3SPaolo Bonzini { 2346c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2347c50d8ae3SPaolo Bonzini } 2348c50d8ae3SPaolo Bonzini 23490cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 23500cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 235103787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2352c50d8ae3SPaolo Bonzini { 2353c50d8ae3SPaolo Bonzini u64 spte; 2354c50d8ae3SPaolo Bonzini 2355c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2356c50d8ae3SPaolo Bonzini 23570cd8dc73SPaolo Bonzini /* 23580cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 235903787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 236003787394SPaolo Bonzini * installing sp. 23610cd8dc73SPaolo Bonzini */ 23620cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 236303787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 23640cd8dc73SPaolo Bonzini 2365cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2366c50d8ae3SPaolo Bonzini 2367c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2368c50d8ae3SPaolo Bonzini 23692ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2370c50d8ae3SPaolo Bonzini 2371c4a48868SLai Jiangshan /* 2372c4a48868SLai Jiangshan * The non-direct sub-pagetable must be updated before linking. For 2373c4a48868SLai Jiangshan * L1 sp, the pagetable is updated via kvm_sync_page() in 2374c4a48868SLai Jiangshan * kvm_mmu_find_shadow_page() without write-protecting the gfn, 2375c4a48868SLai Jiangshan * so sp->unsync can be true or false. For higher level non-direct 2376c4a48868SLai Jiangshan * sp, the pagetable is updated/synced via mmu_sync_children() in 2377c4a48868SLai Jiangshan * FNAME(fetch)(), so sp->unsync_children can only be false. 2378c4a48868SLai Jiangshan * WARN_ON_ONCE() if anything happens unexpectedly. 2379c4a48868SLai Jiangshan */ 2380c4a48868SLai Jiangshan if (WARN_ON_ONCE(sp->unsync_children) || sp->unsync) 2381c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2382c50d8ae3SPaolo Bonzini } 2383c50d8ae3SPaolo Bonzini 23842ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 23852ff9039aSDavid Matlack struct kvm_mmu_page *sp) 23862ff9039aSDavid Matlack { 238703787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 23882ff9039aSDavid Matlack } 23892ff9039aSDavid Matlack 2390c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2391c50d8ae3SPaolo Bonzini unsigned direct_access) 2392c50d8ae3SPaolo Bonzini { 2393c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2394c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2395c50d8ae3SPaolo Bonzini 2396c50d8ae3SPaolo Bonzini /* 2397c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2398c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2399c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2400c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2401c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2402c50d8ae3SPaolo Bonzini */ 24035e3edd7eSSean Christopherson child = spte_to_child_sp(*sptep); 2404c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2405c50d8ae3SPaolo Bonzini return; 2406c50d8ae3SPaolo Bonzini 2407c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2408c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2409c50d8ae3SPaolo Bonzini } 2410c50d8ae3SPaolo Bonzini } 2411c50d8ae3SPaolo Bonzini 24122de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 24132de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 24142de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2415c50d8ae3SPaolo Bonzini { 2416c50d8ae3SPaolo Bonzini u64 pte; 2417c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2418c50d8ae3SPaolo Bonzini 2419c50d8ae3SPaolo Bonzini pte = *spte; 2420c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2421c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2422c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2423c50d8ae3SPaolo Bonzini } else { 24245e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2425c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 24262de4085cSBen Gardon 24272de4085cSBen Gardon /* 24282de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 24292de4085cSBen Gardon * unlikely to be used again in the near future. This 24302de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 24312de4085cSBen Gardon */ 24322de4085cSBen Gardon if (tdp_enabled && invalid_list && 24332de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 24342de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 24352de4085cSBen Gardon invalid_list); 2436c50d8ae3SPaolo Bonzini } 2437ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2438c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2439ace569e0SSean Christopherson } 24402de4085cSBen Gardon return 0; 2441c50d8ae3SPaolo Bonzini } 2442c50d8ae3SPaolo Bonzini 24432de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 24442de4085cSBen Gardon struct kvm_mmu_page *sp, 24452de4085cSBen Gardon struct list_head *invalid_list) 2446c50d8ae3SPaolo Bonzini { 24472de4085cSBen Gardon int zapped = 0; 2448c50d8ae3SPaolo Bonzini unsigned i; 2449c50d8ae3SPaolo Bonzini 24502ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 24512de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 24522de4085cSBen Gardon 24532de4085cSBen Gardon return zapped; 2454c50d8ae3SPaolo Bonzini } 2455c50d8ae3SPaolo Bonzini 245661827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2457c50d8ae3SPaolo Bonzini { 2458c50d8ae3SPaolo Bonzini u64 *sptep; 2459c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2460c50d8ae3SPaolo Bonzini 2461c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2462c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2463c50d8ae3SPaolo Bonzini } 2464c50d8ae3SPaolo Bonzini 2465c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2466c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2467c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2468c50d8ae3SPaolo Bonzini { 2469c50d8ae3SPaolo Bonzini int i, zapped = 0; 2470c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2471c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2472c50d8ae3SPaolo Bonzini 24733bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2474c50d8ae3SPaolo Bonzini return 0; 2475c50d8ae3SPaolo Bonzini 2476c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2477c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2478c50d8ae3SPaolo Bonzini 2479c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2480c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2481c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2482c50d8ae3SPaolo Bonzini zapped++; 2483c50d8ae3SPaolo Bonzini } 2484c50d8ae3SPaolo Bonzini } 2485c50d8ae3SPaolo Bonzini 2486c50d8ae3SPaolo Bonzini return zapped; 2487c50d8ae3SPaolo Bonzini } 2488c50d8ae3SPaolo Bonzini 2489c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2490c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2491c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2492c50d8ae3SPaolo Bonzini int *nr_zapped) 2493c50d8ae3SPaolo Bonzini { 2494527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2495c50d8ae3SPaolo Bonzini 249647b0c2e4SKazuki Takiguchi lockdep_assert_held_write(&kvm->mmu_lock); 2497c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2498c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2499c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 25002de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 250161827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2502c50d8ae3SPaolo Bonzini 2503c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2504c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2505c50d8ae3SPaolo Bonzini 2506767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2507c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2508c50d8ae3SPaolo Bonzini 2509c50d8ae3SPaolo Bonzini if (sp->unsync) 2510c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2511c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2512c50d8ae3SPaolo Bonzini /* Count self */ 2513c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2514f95eec9bSSean Christopherson 2515f95eec9bSSean Christopherson /* 2516f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2517f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2518f95eec9bSSean Christopherson * !sp->root_count. 2519f95eec9bSSean Christopherson */ 2520f95eec9bSSean Christopherson if (sp->role.invalid) 2521f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2522f95eec9bSSean Christopherson else 2523c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 252443a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2525c50d8ae3SPaolo Bonzini } else { 2526f95eec9bSSean Christopherson /* 2527f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2528f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2529f95eec9bSSean Christopherson */ 2530f95eec9bSSean Christopherson list_del(&sp->link); 2531c50d8ae3SPaolo Bonzini 2532c50d8ae3SPaolo Bonzini /* 2533c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2534c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2535c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2536c50d8ae3SPaolo Bonzini */ 2537527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2538c50d8ae3SPaolo Bonzini } 2539c50d8ae3SPaolo Bonzini 254055c510e2SSean Christopherson if (sp->nx_huge_page_disallowed) 254155c510e2SSean Christopherson unaccount_nx_huge_page(kvm, sp); 2542c50d8ae3SPaolo Bonzini 2543c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2544527d5cd7SSean Christopherson 2545527d5cd7SSean Christopherson /* 2546527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2547527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2548527d5cd7SSean Christopherson */ 2549527d5cd7SSean Christopherson if (zapped_root) 2550527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2551c50d8ae3SPaolo Bonzini return list_unstable; 2552c50d8ae3SPaolo Bonzini } 2553c50d8ae3SPaolo Bonzini 2554c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2555c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2556c50d8ae3SPaolo Bonzini { 2557c50d8ae3SPaolo Bonzini int nr_zapped; 2558c50d8ae3SPaolo Bonzini 2559c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2560c50d8ae3SPaolo Bonzini return nr_zapped; 2561c50d8ae3SPaolo Bonzini } 2562c50d8ae3SPaolo Bonzini 2563c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2564c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2565c50d8ae3SPaolo Bonzini { 2566c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2567c50d8ae3SPaolo Bonzini 2568c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2569c50d8ae3SPaolo Bonzini return; 2570c50d8ae3SPaolo Bonzini 2571c50d8ae3SPaolo Bonzini /* 2572c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2573c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2574c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2575c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2576c50d8ae3SPaolo Bonzini * 2577c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2578c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2579c50d8ae3SPaolo Bonzini */ 2580c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2581c50d8ae3SPaolo Bonzini 2582c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2583c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 258487654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2585c50d8ae3SPaolo Bonzini } 2586c50d8ae3SPaolo Bonzini } 2587c50d8ae3SPaolo Bonzini 25886b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 25896b82ef2cSSean Christopherson unsigned long nr_to_zap) 2590c50d8ae3SPaolo Bonzini { 25916b82ef2cSSean Christopherson unsigned long total_zapped = 0; 25926b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2593ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 25946b82ef2cSSean Christopherson bool unstable; 25956b82ef2cSSean Christopherson int nr_zapped; 2596c50d8ae3SPaolo Bonzini 2597c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2598ba7888ddSSean Christopherson return 0; 2599c50d8ae3SPaolo Bonzini 26006b82ef2cSSean Christopherson restart: 26018fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 26026b82ef2cSSean Christopherson /* 26036b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 26046b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 26056b82ef2cSSean Christopherson */ 26066b82ef2cSSean Christopherson if (sp->root_count) 26076b82ef2cSSean Christopherson continue; 26086b82ef2cSSean Christopherson 26096b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 26106b82ef2cSSean Christopherson &nr_zapped); 26116b82ef2cSSean Christopherson total_zapped += nr_zapped; 26126b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2613ba7888ddSSean Christopherson break; 2614ba7888ddSSean Christopherson 26156b82ef2cSSean Christopherson if (unstable) 26166b82ef2cSSean Christopherson goto restart; 2617ba7888ddSSean Christopherson } 26186b82ef2cSSean Christopherson 26196b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 26206b82ef2cSSean Christopherson 26216b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 26226b82ef2cSSean Christopherson return total_zapped; 26236b82ef2cSSean Christopherson } 26246b82ef2cSSean Christopherson 2625afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2626afe8d7e6SSean Christopherson { 2627afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2628afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2629afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2630afe8d7e6SSean Christopherson 2631afe8d7e6SSean Christopherson return 0; 2632c50d8ae3SPaolo Bonzini } 2633c50d8ae3SPaolo Bonzini 2634ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2635ba7888ddSSean Christopherson { 26366b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2637ba7888ddSSean Christopherson 26386b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2639ba7888ddSSean Christopherson return 0; 2640ba7888ddSSean Christopherson 26416b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2642ba7888ddSSean Christopherson 26436e6ec584SSean Christopherson /* 26446e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 26456e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 26466e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 26476e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2648c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 26496e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 26506e6ec584SSean Christopherson * page fault paths. 26516e6ec584SSean Christopherson */ 2652ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2653ba7888ddSSean Christopherson return -ENOSPC; 2654ba7888ddSSean Christopherson return 0; 2655ba7888ddSSean Christopherson } 2656ba7888ddSSean Christopherson 2657c50d8ae3SPaolo Bonzini /* 2658c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2659c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2660c50d8ae3SPaolo Bonzini */ 2661c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2662c50d8ae3SPaolo Bonzini { 2663531810caSBen Gardon write_lock(&kvm->mmu_lock); 2664c50d8ae3SPaolo Bonzini 2665c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 26666b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 26676b82ef2cSSean Christopherson goal_nr_mmu_pages); 2668c50d8ae3SPaolo Bonzini 2669c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2670c50d8ae3SPaolo Bonzini } 2671c50d8ae3SPaolo Bonzini 2672c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2673c50d8ae3SPaolo Bonzini 2674531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2675c50d8ae3SPaolo Bonzini } 2676c50d8ae3SPaolo Bonzini 2677c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2678c50d8ae3SPaolo Bonzini { 2679c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2680c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2681c50d8ae3SPaolo Bonzini int r; 2682c50d8ae3SPaolo Bonzini 2683c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2684c50d8ae3SPaolo Bonzini r = 0; 2685531810caSBen Gardon write_lock(&kvm->mmu_lock); 2686767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2687c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2688c50d8ae3SPaolo Bonzini sp->role.word); 2689c50d8ae3SPaolo Bonzini r = 1; 2690c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2691c50d8ae3SPaolo Bonzini } 2692c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2693531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2694c50d8ae3SPaolo Bonzini 2695c50d8ae3SPaolo Bonzini return r; 2696c50d8ae3SPaolo Bonzini } 269796ad91aeSSean Christopherson 269896ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 269996ad91aeSSean Christopherson { 270096ad91aeSSean Christopherson gpa_t gpa; 270196ad91aeSSean Christopherson int r; 270296ad91aeSSean Christopherson 2703347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 270496ad91aeSSean Christopherson return 0; 270596ad91aeSSean Christopherson 270696ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 270796ad91aeSSean Christopherson 270896ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 270996ad91aeSSean Christopherson 271096ad91aeSSean Christopherson return r; 271196ad91aeSSean Christopherson } 2712c50d8ae3SPaolo Bonzini 27134d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2714c50d8ae3SPaolo Bonzini { 2715c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 27164d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2717c50d8ae3SPaolo Bonzini sp->unsync = 1; 2718c50d8ae3SPaolo Bonzini 2719c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2720c50d8ae3SPaolo Bonzini } 2721c50d8ae3SPaolo Bonzini 27220337f585SSean Christopherson /* 27230337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 27240337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 27250337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 27260337f585SSean Christopherson * be write-protected. 27270337f585SSean Christopherson */ 27288283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 27292839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2730c50d8ae3SPaolo Bonzini { 2731c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2732ce25681dSSean Christopherson bool locked = false; 2733c50d8ae3SPaolo Bonzini 27340337f585SSean Christopherson /* 27350337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 27360337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 27370337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 27380337f585SSean Christopherson */ 27394d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 27400337f585SSean Christopherson return -EPERM; 2741c50d8ae3SPaolo Bonzini 27420337f585SSean Christopherson /* 27430337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 27440337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 27450337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 27460337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 27470337f585SSean Christopherson */ 2748767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2749c50d8ae3SPaolo Bonzini if (!can_unsync) 27500337f585SSean Christopherson return -EPERM; 2751c50d8ae3SPaolo Bonzini 2752c50d8ae3SPaolo Bonzini if (sp->unsync) 2753c50d8ae3SPaolo Bonzini continue; 2754c50d8ae3SPaolo Bonzini 27552839180cSPaolo Bonzini if (prefetch) 2756f1c4a88cSLai Jiangshan return -EEXIST; 2757f1c4a88cSLai Jiangshan 2758ce25681dSSean Christopherson /* 2759ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2760ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2761ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2762ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2763ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2764ce25681dSSean Christopherson */ 2765ce25681dSSean Christopherson if (!locked) { 2766ce25681dSSean Christopherson locked = true; 27674d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2768ce25681dSSean Christopherson 2769ce25681dSSean Christopherson /* 2770ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2771ce25681dSSean Christopherson * may have since marked the page unsync. A false 2772ce25681dSSean Christopherson * positive on the unprotected check above is not 2773ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2774ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2775ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2776ce25681dSSean Christopherson */ 2777ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2778ce25681dSSean Christopherson continue; 2779ce25681dSSean Christopherson } 2780ce25681dSSean Christopherson 27813bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 27824d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2783c50d8ae3SPaolo Bonzini } 2784ce25681dSSean Christopherson if (locked) 27854d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2786c50d8ae3SPaolo Bonzini 2787c50d8ae3SPaolo Bonzini /* 2788c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2789c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2790c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2791c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2792c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2793c50d8ae3SPaolo Bonzini * following could happen: 2794c50d8ae3SPaolo Bonzini * 2795c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2796c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2797c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2798c50d8ae3SPaolo Bonzini * to be writable 2799c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2800c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2801c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2802c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2803c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2804c50d8ae3SPaolo Bonzini * fault. 2805c50d8ae3SPaolo Bonzini * 2806c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2807c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2808c50d8ae3SPaolo Bonzini * 28090337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 28100337f585SSean Christopherson * false and skips the page. 2811c50d8ae3SPaolo Bonzini * 2812c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2813c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2814c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2815c50d8ae3SPaolo Bonzini * gets used. 2816c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2817c50d8ae3SPaolo Bonzini * as unsync 2818c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2819c50d8ae3SPaolo Bonzini * 2820c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2821264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2822264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2823c50d8ae3SPaolo Bonzini */ 2824c50d8ae3SPaolo Bonzini smp_wmb(); 2825c50d8ae3SPaolo Bonzini 28260337f585SSean Christopherson return 0; 2827c50d8ae3SPaolo Bonzini } 2828c50d8ae3SPaolo Bonzini 28298a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 28308a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2831a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2832799a4190SBen Gardon { 2833d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2834eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2835c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2836c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2837c50d8ae3SPaolo Bonzini bool flush = false; 2838ad67e480SPaolo Bonzini bool wrprot; 2839d786c778SPaolo Bonzini u64 spte; 2840c50d8ae3SPaolo Bonzini 2841a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2842a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 28432839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2844a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2845c50d8ae3SPaolo Bonzini 2846c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2847c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2848c50d8ae3SPaolo Bonzini 2849a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 28501075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2851a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2852a54aa15cSSean Christopherson return RET_PF_EMULATE; 2853a54aa15cSSean Christopherson } 2854a54aa15cSSean Christopherson 2855c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2856c50d8ae3SPaolo Bonzini /* 2857c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2858c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2859c50d8ae3SPaolo Bonzini */ 28603bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2861c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2862c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2863c50d8ae3SPaolo Bonzini 28645e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2865c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2866c50d8ae3SPaolo Bonzini flush = true; 2867c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2868c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2869c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2870c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2871c50d8ae3SPaolo Bonzini flush = true; 2872c50d8ae3SPaolo Bonzini } else 2873c50d8ae3SPaolo Bonzini was_rmapped = 1; 2874c50d8ae3SPaolo Bonzini } 2875c50d8ae3SPaolo Bonzini 28762839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 28777158bee4SPaolo Bonzini true, host_writable, &spte); 2878d786c778SPaolo Bonzini 2879d786c778SPaolo Bonzini if (*sptep == spte) { 2880d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2881d786c778SPaolo Bonzini } else { 2882d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 28835959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2884c50d8ae3SPaolo Bonzini } 2885c50d8ae3SPaolo Bonzini 2886ad67e480SPaolo Bonzini if (wrprot) { 2887c50d8ae3SPaolo Bonzini if (write_fault) 2888c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2889c50d8ae3SPaolo Bonzini } 2890c50d8ae3SPaolo Bonzini 2891d786c778SPaolo Bonzini if (flush) 2892c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2893c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2894c50d8ae3SPaolo Bonzini 2895c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2896c50d8ae3SPaolo Bonzini 2897c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2898d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 28996a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 29006a97575dSDavid Matlack } else { 29016a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 290279e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2903c50d8ae3SPaolo Bonzini } 2904c50d8ae3SPaolo Bonzini 2905c50d8ae3SPaolo Bonzini return ret; 2906c50d8ae3SPaolo Bonzini } 2907c50d8ae3SPaolo Bonzini 2908c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2909c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2910c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2911c50d8ae3SPaolo Bonzini { 2912c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2913c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 29140a2b64c5SBen Gardon unsigned int access = sp->role.access; 2915c50d8ae3SPaolo Bonzini int i, ret; 2916c50d8ae3SPaolo Bonzini gfn_t gfn; 2917c50d8ae3SPaolo Bonzini 291879e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 2919c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2920c50d8ae3SPaolo Bonzini if (!slot) 2921c50d8ae3SPaolo Bonzini return -1; 2922c50d8ae3SPaolo Bonzini 2923c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2924c50d8ae3SPaolo Bonzini if (ret <= 0) 2925c50d8ae3SPaolo Bonzini return -1; 2926c50d8ae3SPaolo Bonzini 2927c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 29288a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2929a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2930c50d8ae3SPaolo Bonzini put_page(pages[i]); 2931c50d8ae3SPaolo Bonzini } 2932c50d8ae3SPaolo Bonzini 2933c50d8ae3SPaolo Bonzini return 0; 2934c50d8ae3SPaolo Bonzini } 2935c50d8ae3SPaolo Bonzini 2936c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2937c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2938c50d8ae3SPaolo Bonzini { 2939c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2940c50d8ae3SPaolo Bonzini int i; 2941c50d8ae3SPaolo Bonzini 2942c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2943c50d8ae3SPaolo Bonzini 294479e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 2945c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2946c50d8ae3SPaolo Bonzini 2947c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2948c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2949c50d8ae3SPaolo Bonzini if (!start) 2950c50d8ae3SPaolo Bonzini continue; 2951c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2952c6cecc4bSSean Christopherson return; 2953c50d8ae3SPaolo Bonzini start = NULL; 2954c50d8ae3SPaolo Bonzini } else if (!start) 2955c50d8ae3SPaolo Bonzini start = spte; 2956c50d8ae3SPaolo Bonzini } 2957c6cecc4bSSean Christopherson if (start) 2958c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2959c50d8ae3SPaolo Bonzini } 2960c50d8ae3SPaolo Bonzini 2961c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2962c50d8ae3SPaolo Bonzini { 2963c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2964c50d8ae3SPaolo Bonzini 296557354682SSean Christopherson sp = sptep_to_sp(sptep); 2966c50d8ae3SPaolo Bonzini 2967c50d8ae3SPaolo Bonzini /* 2968c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2969c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2970c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2971c50d8ae3SPaolo Bonzini */ 2972c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2973c50d8ae3SPaolo Bonzini return; 2974c50d8ae3SPaolo Bonzini 29753bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2976c50d8ae3SPaolo Bonzini return; 2977c50d8ae3SPaolo Bonzini 29784a42d848SDavid Stevens /* 29794a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 29804a42d848SDavid Stevens * accidentally prefetching those addresses. 29814a42d848SDavid Stevens */ 298220ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 29834a42d848SDavid Stevens return; 29844a42d848SDavid Stevens 2985c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2986c50d8ae3SPaolo Bonzini } 2987c50d8ae3SPaolo Bonzini 298865e3b446SSean Christopherson /* 298965e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 299065e3b446SSean Christopherson * 299165e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 299265e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 299365e3b446SSean Christopherson * 299465e3b446SSean Christopherson * There are several ways to safely use this helper: 299565e3b446SSean Christopherson * 299620ec3ebdSChao Peng * - Check mmu_invalidate_retry_hva() after grabbing the mapping level, before 299765e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 299865e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 299965e3b446SSean Christopherson * 300065e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 300165e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 300265e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 300365e3b446SSean Christopherson * 300465e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 300565e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 300665e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 300765e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 300865e3b446SSean Christopherson * 300965e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 301065e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 301165e3b446SSean Christopherson * race with the primary MMU occurs. 301265e3b446SSean Christopherson */ 3013a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 30148ca6f063SBen Gardon const struct kvm_memory_slot *slot) 3015db543216SSean Christopherson { 3016284dc493SSean Christopherson int level = PG_LEVEL_4K; 3017db543216SSean Christopherson unsigned long hva; 301844187235SMingwei Zhang unsigned long flags; 301944187235SMingwei Zhang pgd_t pgd; 302044187235SMingwei Zhang p4d_t p4d; 302144187235SMingwei Zhang pud_t pud; 302244187235SMingwei Zhang pmd_t pmd; 3023db543216SSean Christopherson 30245d49f08cSSean Christopherson /* 3025293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 3026293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 3027293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 3028293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 3029293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 3030293e306eSSean Christopherson * read-only memslot. 3031293e306eSSean Christopherson */ 3032db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 3033db543216SSean Christopherson 303444187235SMingwei Zhang /* 303565e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 303665e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 303765e3b446SSean Christopherson * the original page table. 303844187235SMingwei Zhang */ 303944187235SMingwei Zhang local_irq_save(flags); 3040db543216SSean Christopherson 304165e3b446SSean Christopherson /* 304265e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 304365e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 304465e3b446SSean Christopherson * walk into the weeks, e.g. p*d_large() returns false (sees the old 304565e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 304665e3b446SSean Christopherson * of the old page table (sees the new value). 304765e3b446SSean Christopherson */ 304844187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 304944187235SMingwei Zhang if (pgd_none(pgd)) 305044187235SMingwei Zhang goto out; 305144187235SMingwei Zhang 305244187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 305344187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 305444187235SMingwei Zhang goto out; 305544187235SMingwei Zhang 305644187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 305744187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 305844187235SMingwei Zhang goto out; 305944187235SMingwei Zhang 306044187235SMingwei Zhang if (pud_large(pud)) { 306144187235SMingwei Zhang level = PG_LEVEL_1G; 306244187235SMingwei Zhang goto out; 306344187235SMingwei Zhang } 306444187235SMingwei Zhang 306544187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 306644187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 306744187235SMingwei Zhang goto out; 306844187235SMingwei Zhang 306944187235SMingwei Zhang if (pmd_large(pmd)) 307044187235SMingwei Zhang level = PG_LEVEL_2M; 307144187235SMingwei Zhang 307244187235SMingwei Zhang out: 307344187235SMingwei Zhang local_irq_restore(flags); 3074db543216SSean Christopherson return level; 3075db543216SSean Christopherson } 3076db543216SSean Christopherson 30778ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 30788ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 3079a8ac499bSSean Christopherson int max_level) 30801b6d9d9eSSean Christopherson { 30811b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3082ec607a56SPaolo Bonzini int host_level; 30831b6d9d9eSSean Christopherson 30841b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 30851b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 30861b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 30871b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 30881b6d9d9eSSean Christopherson break; 30891b6d9d9eSSean Christopherson } 30901b6d9d9eSSean Christopherson 30911b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 30921b6d9d9eSSean Christopherson return PG_LEVEL_4K; 30931b6d9d9eSSean Christopherson 3094a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3095ec607a56SPaolo Bonzini return min(host_level, max_level); 30961b6d9d9eSSean Christopherson } 30971b6d9d9eSSean Christopherson 309873a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 30990885904dSSean Christopherson { 3100e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 310117eff019SSean Christopherson kvm_pfn_t mask; 31020885904dSSean Christopherson 310373a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 31043cf06612SSean Christopherson 310573a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 310673a3c659SPaolo Bonzini return; 310717eff019SSean Christopherson 31085d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 310973a3c659SPaolo Bonzini return; 311017eff019SSean Christopherson 3111e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 311273a3c659SPaolo Bonzini return; 3113293e306eSSean Christopherson 31143cf06612SSean Christopherson /* 31153cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 31163cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 31173cf06612SSean Christopherson */ 311873a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 3119a8ac499bSSean Christopherson fault->gfn, fault->max_level); 312073a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 312173a3c659SPaolo Bonzini return; 31224cd071d1SSean Christopherson 31230885904dSSean Christopherson /* 312420ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 31254cd071d1SSean Christopherson * the pmd can't be split from under us. 31260885904dSSean Christopherson */ 312773a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 312873a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 312973a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 313073a3c659SPaolo Bonzini fault->pfn &= ~mask; 31310885904dSSean Christopherson } 31320885904dSSean Christopherson 3133536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3134c50d8ae3SPaolo Bonzini { 3135536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3136536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3137c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 313876901e56SMingwei Zhang !is_large_pte(spte) && 313976901e56SMingwei Zhang spte_to_child_sp(spte)->nx_huge_page_disallowed) { 3140c50d8ae3SPaolo Bonzini /* 31416c882ef4SDavid Matlack * A small SPTE exists for this pfn, but FNAME(fetch), 31426c882ef4SDavid Matlack * direct_map(), or kvm_tdp_mmu_map() would like to create a 31436c882ef4SDavid Matlack * large PTE instead: just force them to go down another level, 31446c882ef4SDavid Matlack * patching back for them into pfn the next 9 bits of the 31456c882ef4SDavid Matlack * address. 3146c50d8ae3SPaolo Bonzini */ 3147536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3148536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3149536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3150536f0e6aSPaolo Bonzini fault->goal_level--; 3151c50d8ae3SPaolo Bonzini } 3152c50d8ae3SPaolo Bonzini } 3153c50d8ae3SPaolo Bonzini 31546c882ef4SDavid Matlack static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3155c50d8ae3SPaolo Bonzini { 3156c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3157c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 315873a3c659SPaolo Bonzini int ret; 315943b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3160c50d8ae3SPaolo Bonzini 316173a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 31624cd071d1SSean Christopherson 3163f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 316443b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3165c50d8ae3SPaolo Bonzini /* 3166c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3167c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3168c50d8ae3SPaolo Bonzini */ 316973a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3170536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3171c50d8ae3SPaolo Bonzini 317243b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 317373a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3174c50d8ae3SPaolo Bonzini break; 3175c50d8ae3SPaolo Bonzini 31762e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 31770cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 31780cd8dc73SPaolo Bonzini continue; 3179c50d8ae3SPaolo Bonzini 3180c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 3181b5b0977fSSean Christopherson if (fault->huge_page_disallowed) 318255c510e2SSean Christopherson account_nx_huge_page(vcpu->kvm, sp, 3183428e9216SSean Christopherson fault->req_level >= it.level); 3184c50d8ae3SPaolo Bonzini } 3185c50d8ae3SPaolo Bonzini 3186b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3187b1a429fbSSean Christopherson return -EFAULT; 3188b1a429fbSSean Christopherson 31898a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3190a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 319112703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 319212703759SSean Christopherson return ret; 319312703759SSean Christopherson 3194c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3195c50d8ae3SPaolo Bonzini return ret; 3196c50d8ae3SPaolo Bonzini } 3197c50d8ae3SPaolo Bonzini 3198cd08d178SDavid Matlack static void kvm_send_hwpoison_signal(struct kvm_memory_slot *slot, gfn_t gfn) 3199c50d8ae3SPaolo Bonzini { 3200cd08d178SDavid Matlack unsigned long hva = gfn_to_hva_memslot(slot, gfn); 3201cd08d178SDavid Matlack 3202cd08d178SDavid Matlack send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); 3203c50d8ae3SPaolo Bonzini } 3204c50d8ae3SPaolo Bonzini 3205cd08d178SDavid Matlack static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3206c50d8ae3SPaolo Bonzini { 3207cd08d178SDavid Matlack if (is_sigpending_pfn(fault->pfn)) { 320876657687SPeter Xu kvm_handle_signal_exit(vcpu); 320976657687SPeter Xu return -EINTR; 321076657687SPeter Xu } 321176657687SPeter Xu 3212c50d8ae3SPaolo Bonzini /* 3213c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3214c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3215c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3216c50d8ae3SPaolo Bonzini */ 3217cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_RO_FAULT) 3218c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3219c50d8ae3SPaolo Bonzini 3220cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_HWPOISON) { 3221cd08d178SDavid Matlack kvm_send_hwpoison_signal(fault->slot, fault->gfn); 3222c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3223c50d8ae3SPaolo Bonzini } 3224c50d8ae3SPaolo Bonzini 3225c50d8ae3SPaolo Bonzini return -EFAULT; 3226c50d8ae3SPaolo Bonzini } 3227c50d8ae3SPaolo Bonzini 3228354c908cSDavid Matlack static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu, 3229354c908cSDavid Matlack struct kvm_page_fault *fault, 32305276c616SSean Christopherson unsigned int access) 3231c50d8ae3SPaolo Bonzini { 32323a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 32333a13f4feSPaolo Bonzini 32343a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3235c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 3236354c908cSDavid Matlack 323730ab5901SSean Christopherson /* 323830ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 323930ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 3240354c908cSDavid Matlack * MMIO SPTE will just be an expensive nop. 324130ab5901SSean Christopherson */ 3242354c908cSDavid Matlack if (unlikely(!enable_mmio_caching)) 32435276c616SSean Christopherson return RET_PF_EMULATE; 3244354c908cSDavid Matlack 3245354c908cSDavid Matlack /* 3246354c908cSDavid Matlack * Do not create an MMIO SPTE for a gfn greater than host.MAXPHYADDR, 3247354c908cSDavid Matlack * any guest that generates such gfns is running nested and is being 3248354c908cSDavid Matlack * tricked by L0 userspace (you can observe gfn > L1.MAXPHYADDR if and 3249354c908cSDavid Matlack * only if L1's MAXPHYADDR is inaccurate with respect to the 3250354c908cSDavid Matlack * hardware's). 3251354c908cSDavid Matlack */ 3252354c908cSDavid Matlack if (unlikely(fault->gfn > kvm_mmu_max_gfn())) 3253354c908cSDavid Matlack return RET_PF_EMULATE; 3254c50d8ae3SPaolo Bonzini 32555276c616SSean Christopherson return RET_PF_CONTINUE; 3256c50d8ae3SPaolo Bonzini } 3257c50d8ae3SPaolo Bonzini 32583c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3259c50d8ae3SPaolo Bonzini { 3260c50d8ae3SPaolo Bonzini /* 32615c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 32625c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 32635c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 32645c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3265c50d8ae3SPaolo Bonzini */ 32663c8ad5a6SPaolo Bonzini if (fault->rsvd) 3267c50d8ae3SPaolo Bonzini return false; 3268c50d8ae3SPaolo Bonzini 3269c50d8ae3SPaolo Bonzini /* 3270c50d8ae3SPaolo Bonzini * #PF can be fast if: 3271c50d8ae3SPaolo Bonzini * 327254275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 327354275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 327454275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 327554275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 327654275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 327754275f74SSean Christopherson * mechanism only supports direct MMUs. 327854275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 327954275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 328054275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 328154275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 328254275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3283c50d8ae3SPaolo Bonzini */ 32845c64aba5SSean Christopherson if (!fault->present) 32855c64aba5SSean Christopherson return !kvm_ad_enabled(); 32865c64aba5SSean Christopherson 32875c64aba5SSean Christopherson /* 32885c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 32895c64aba5SSean Christopherson * the "exec" flag. 32905c64aba5SSean Christopherson */ 32915c64aba5SSean Christopherson return fault->write; 3292c50d8ae3SPaolo Bonzini } 3293c50d8ae3SPaolo Bonzini 3294c50d8ae3SPaolo Bonzini /* 3295c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3296c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3297c50d8ae3SPaolo Bonzini */ 3298c50d8ae3SPaolo Bonzini static bool 3299e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3300c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3301c50d8ae3SPaolo Bonzini { 3302c50d8ae3SPaolo Bonzini /* 3303c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3304c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3305c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3306c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3307c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3308c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3309c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3310c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3311c50d8ae3SPaolo Bonzini * 3312c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3313c50d8ae3SPaolo Bonzini */ 33142db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3315c50d8ae3SPaolo Bonzini return false; 3316c50d8ae3SPaolo Bonzini 3317e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3318e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3319c50d8ae3SPaolo Bonzini 3320c50d8ae3SPaolo Bonzini return true; 3321c50d8ae3SPaolo Bonzini } 3322c50d8ae3SPaolo Bonzini 33233c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3324c50d8ae3SPaolo Bonzini { 33253c8ad5a6SPaolo Bonzini if (fault->exec) 3326c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3327c50d8ae3SPaolo Bonzini 33283c8ad5a6SPaolo Bonzini if (fault->write) 3329c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3330c50d8ae3SPaolo Bonzini 3331c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3332c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3333c50d8ae3SPaolo Bonzini } 3334c50d8ae3SPaolo Bonzini 3335c50d8ae3SPaolo Bonzini /* 33366e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 33376e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 33386e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 33396e8eb206SDavid Matlack * 33406e8eb206SDavid Matlack * Contract: 33416e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 33426e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 33436e8eb206SDavid Matlack */ 33446e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 33456e8eb206SDavid Matlack { 33466e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 33476e8eb206SDavid Matlack u64 old_spte; 33486e8eb206SDavid Matlack u64 *sptep = NULL; 33496e8eb206SDavid Matlack 33506e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 33516e8eb206SDavid Matlack sptep = iterator.sptep; 33526e8eb206SDavid Matlack *spte = old_spte; 33536e8eb206SDavid Matlack } 33546e8eb206SDavid Matlack 33556e8eb206SDavid Matlack return sptep; 33566e8eb206SDavid Matlack } 33576e8eb206SDavid Matlack 33586e8eb206SDavid Matlack /* 3359c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3360c50d8ae3SPaolo Bonzini */ 33613c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3362c50d8ae3SPaolo Bonzini { 3363c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3364c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3365c50d8ae3SPaolo Bonzini u64 spte = 0ull; 33666e8eb206SDavid Matlack u64 *sptep = NULL; 3367c50d8ae3SPaolo Bonzini uint retry_count = 0; 3368c50d8ae3SPaolo Bonzini 33693c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3370c4371c2aSSean Christopherson return ret; 3371c50d8ae3SPaolo Bonzini 3372c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3373c50d8ae3SPaolo Bonzini 3374c50d8ae3SPaolo Bonzini do { 3375c50d8ae3SPaolo Bonzini u64 new_spte; 3376c50d8ae3SPaolo Bonzini 3377dfe0ecc6SSean Christopherson if (tdp_mmu_enabled) 33783c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 33796e8eb206SDavid Matlack else 33803c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3381c50d8ae3SPaolo Bonzini 3382ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3383ec89e643SSean Christopherson break; 3384ec89e643SSean Christopherson 33856e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3386c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3387c50d8ae3SPaolo Bonzini break; 3388c50d8ae3SPaolo Bonzini 3389c50d8ae3SPaolo Bonzini /* 3390c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3391c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3392c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3393c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3394c50d8ae3SPaolo Bonzini * current CPU took the fault. 3395c50d8ae3SPaolo Bonzini * 3396c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3397c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3398c50d8ae3SPaolo Bonzini */ 33993c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3400c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3401c50d8ae3SPaolo Bonzini break; 3402c50d8ae3SPaolo Bonzini } 3403c50d8ae3SPaolo Bonzini 3404c50d8ae3SPaolo Bonzini new_spte = spte; 3405c50d8ae3SPaolo Bonzini 340654275f74SSean Christopherson /* 340754275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 340854275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 340954275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 341054275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 341154275f74SSean Christopherson */ 341254275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3413c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3414c50d8ae3SPaolo Bonzini 3415c50d8ae3SPaolo Bonzini /* 341654275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 341754275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 341854275f74SSean Christopherson * that were write-protected for dirty-logging or access 341954275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 342054275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 342154275f74SSean Christopherson * The is_access_allowed() check above handles the common case 342254275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 342354275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 342454275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3425c50d8ae3SPaolo Bonzini */ 3426706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3427c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3428c50d8ae3SPaolo Bonzini 3429c50d8ae3SPaolo Bonzini /* 343010c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 343110c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 343210c30de0SJunaid Shahid * first page into the dirty-bitmap in 3433c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3434c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3435c50d8ae3SPaolo Bonzini * 3436c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3437c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3438c50d8ae3SPaolo Bonzini */ 343910c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 344010c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3441c50d8ae3SPaolo Bonzini break; 3442c50d8ae3SPaolo Bonzini } 3443c50d8ae3SPaolo Bonzini 3444c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3445c50d8ae3SPaolo Bonzini if (new_spte == spte || 34463c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3447c50d8ae3SPaolo Bonzini break; 3448c50d8ae3SPaolo Bonzini 3449c50d8ae3SPaolo Bonzini /* 3450c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3451c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 34523ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3453c50d8ae3SPaolo Bonzini */ 3454e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3455c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3456c50d8ae3SPaolo Bonzini break; 3457c4371c2aSSean Christopherson } 3458c50d8ae3SPaolo Bonzini 3459c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 34608d20bd63SSean Christopherson pr_warn_once("Fast #PF retrying more than 4 times.\n"); 3461c50d8ae3SPaolo Bonzini break; 3462c50d8ae3SPaolo Bonzini } 3463c50d8ae3SPaolo Bonzini 3464c50d8ae3SPaolo Bonzini } while (true); 3465c50d8ae3SPaolo Bonzini 3466f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3467c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3468c50d8ae3SPaolo Bonzini 34691075d41eSSean Christopherson if (ret != RET_PF_INVALID) 34701075d41eSSean Christopherson vcpu->stat.pf_fast++; 34711075d41eSSean Christopherson 3472c4371c2aSSean Christopherson return ret; 3473c50d8ae3SPaolo Bonzini } 3474c50d8ae3SPaolo Bonzini 3475c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3476c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3477c50d8ae3SPaolo Bonzini { 3478c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3479c50d8ae3SPaolo Bonzini 3480c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3481c50d8ae3SPaolo Bonzini return; 3482c50d8ae3SPaolo Bonzini 34835e3edd7eSSean Christopherson /* 34845e3edd7eSSean Christopherson * The "root" may be a special root, e.g. a PAE entry, treat it as a 34855e3edd7eSSean Christopherson * SPTE to ensure any non-PA bits are dropped. 34865e3edd7eSSean Christopherson */ 34875e3edd7eSSean Christopherson sp = spte_to_child_sp(*root_hpa); 34889191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 34899191b8f0SPaolo Bonzini return; 349002c00b3aSBen Gardon 3491897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 34926103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 349376eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3494c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3495c50d8ae3SPaolo Bonzini 3496c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3497c50d8ae3SPaolo Bonzini } 3498c50d8ae3SPaolo Bonzini 3499c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 35000c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3501c50d8ae3SPaolo Bonzini ulong roots_to_free) 3502c50d8ae3SPaolo Bonzini { 3503c50d8ae3SPaolo Bonzini int i; 3504c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3505594bef79SPaolo Bonzini bool free_active_root; 3506c50d8ae3SPaolo Bonzini 3507c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3508c50d8ae3SPaolo Bonzini 3509c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3510594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3511594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3512594bef79SPaolo Bonzini 3513594bef79SPaolo Bonzini if (!free_active_root) { 3514c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3515c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3516c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3517c50d8ae3SPaolo Bonzini break; 3518c50d8ae3SPaolo Bonzini 3519c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3520c50d8ae3SPaolo Bonzini return; 3521c50d8ae3SPaolo Bonzini } 3522c50d8ae3SPaolo Bonzini 3523531810caSBen Gardon write_lock(&kvm->mmu_lock); 3524c50d8ae3SPaolo Bonzini 3525c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3526c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 35274d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3528c50d8ae3SPaolo Bonzini &invalid_list); 3529c50d8ae3SPaolo Bonzini 3530c50d8ae3SPaolo Bonzini if (free_active_root) { 3531594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3532b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 353304d45551SSean Christopherson } else if (mmu->pae_root) { 3534c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3535c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3536c834e5e4SSean Christopherson continue; 3537c834e5e4SSean Christopherson 3538c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3539c50d8ae3SPaolo Bonzini &invalid_list); 3540c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3541c50d8ae3SPaolo Bonzini } 3542c50d8ae3SPaolo Bonzini } 3543b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3544b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3545c50d8ae3SPaolo Bonzini } 3546c50d8ae3SPaolo Bonzini 35474d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3548531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3549c50d8ae3SPaolo Bonzini } 3550c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3551c50d8ae3SPaolo Bonzini 35520c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 355325b62c62SSean Christopherson { 355425b62c62SSean Christopherson unsigned long roots_to_free = 0; 355525b62c62SSean Christopherson hpa_t root_hpa; 355625b62c62SSean Christopherson int i; 355725b62c62SSean Christopherson 355825b62c62SSean Christopherson /* 355925b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 356025b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 356125b62c62SSean Christopherson */ 35627a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 356325b62c62SSean Christopherson 356425b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 356525b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 356625b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 356725b62c62SSean Christopherson continue; 356825b62c62SSean Christopherson 356925b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 357025b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 357125b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 357225b62c62SSean Christopherson } 357325b62c62SSean Christopherson 35740c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 357525b62c62SSean Christopherson } 357625b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 357725b62c62SSean Christopherson 357825b62c62SSean Christopherson 3579c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3580c50d8ae3SPaolo Bonzini { 3581c50d8ae3SPaolo Bonzini int ret = 0; 3582c50d8ae3SPaolo Bonzini 3583995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3584c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3585c50d8ae3SPaolo Bonzini ret = 1; 3586c50d8ae3SPaolo Bonzini } 3587c50d8ae3SPaolo Bonzini 3588c50d8ae3SPaolo Bonzini return ret; 3589c50d8ae3SPaolo Bonzini } 3590c50d8ae3SPaolo Bonzini 35912e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 359286938ab6SDavid Matlack u8 level) 3593c50d8ae3SPaolo Bonzini { 35942e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3595c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 35968123f265SSean Christopherson 35972e65e842SDavid Matlack role.level = level; 35982e65e842SDavid Matlack role.quadrant = quadrant; 35992e65e842SDavid Matlack 36007f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 36017f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 36027f497775SDavid Matlack 360387654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 36048123f265SSean Christopherson ++sp->root_count; 36058123f265SSean Christopherson 36068123f265SSean Christopherson return __pa(sp->spt); 36078123f265SSean Christopherson } 36088123f265SSean Christopherson 36098123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 36108123f265SSean Christopherson { 3611b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3612a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 36138123f265SSean Christopherson hpa_t root; 3614c50d8ae3SPaolo Bonzini unsigned i; 36154a38162eSPaolo Bonzini int r; 36164a38162eSPaolo Bonzini 36174a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36184a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36194a38162eSPaolo Bonzini if (r < 0) 36204a38162eSPaolo Bonzini goto out_unlock; 3621c50d8ae3SPaolo Bonzini 36221f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 362302c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3624b9e5603cSPaolo Bonzini mmu->root.hpa = root; 362502c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 362686938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3627b9e5603cSPaolo Bonzini mmu->root.hpa = root; 36288123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 36294a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 36304a38162eSPaolo Bonzini r = -EIO; 36314a38162eSPaolo Bonzini goto out_unlock; 36324a38162eSPaolo Bonzini } 363373ad1606SSean Christopherson 3634c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3635c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3636c50d8ae3SPaolo Bonzini 36377f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 36382e65e842SDavid Matlack PT32_ROOT_LEVEL); 363917e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3640d2263de1SYuan Yao shadow_me_value; 3641c50d8ae3SPaolo Bonzini } 3642b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 364373ad1606SSean Christopherson } else { 364473ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 36454a38162eSPaolo Bonzini r = -EIO; 36464a38162eSPaolo Bonzini goto out_unlock; 364773ad1606SSean Christopherson } 36483651c7fcSSean Christopherson 3649b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3650b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 36514a38162eSPaolo Bonzini out_unlock: 36524a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 36534a38162eSPaolo Bonzini return r; 3654c50d8ae3SPaolo Bonzini } 3655c50d8ae3SPaolo Bonzini 36561e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 36571e76a3ceSDavid Stevens { 36581e76a3ceSDavid Stevens struct kvm_memslots *slots; 36591e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3660a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 36611e76a3ceSDavid Stevens 36621e76a3ceSDavid Stevens /* 36631e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 36641e76a3ceSDavid Stevens * taking the lock. 36651e76a3ceSDavid Stevens */ 36661e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 36671e76a3ceSDavid Stevens return 0; 36681e76a3ceSDavid Stevens 36691e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 36701e76a3ceSDavid Stevens 36711e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 36721e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 36731e76a3ceSDavid Stevens goto out_unlock; 36741e76a3ceSDavid Stevens 36751e76a3ceSDavid Stevens /* 36761e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 36771e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 36781e76a3ceSDavid Stevens */ 36791e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 36801e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 36811e76a3ceSDavid Stevens goto out_success; 36821e76a3ceSDavid Stevens 36831e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 36841e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3685a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 36861e76a3ceSDavid Stevens /* 36871e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 36881e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 36891e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 36901e76a3ceSDavid Stevens * failure to avoid having to track which allocations 36911e76a3ceSDavid Stevens * were made now versus when the memslot was created. 36921e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 36931e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 36941e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 36951e76a3ceSDavid Stevens */ 36961e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 36971e76a3ceSDavid Stevens if (r) 36981e76a3ceSDavid Stevens goto out_unlock; 36991e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 37001e76a3ceSDavid Stevens if (r) 37011e76a3ceSDavid Stevens goto out_unlock; 37021e76a3ceSDavid Stevens } 37031e76a3ceSDavid Stevens } 37041e76a3ceSDavid Stevens 37051e76a3ceSDavid Stevens /* 37061e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 37071e76a3ceSDavid Stevens * all the related pointers are set. 37081e76a3ceSDavid Stevens */ 37091e76a3ceSDavid Stevens out_success: 37101e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 37111e76a3ceSDavid Stevens 37121e76a3ceSDavid Stevens out_unlock: 37131e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 37141e76a3ceSDavid Stevens return r; 37151e76a3ceSDavid Stevens } 37161e76a3ceSDavid Stevens 3717c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3718c50d8ae3SPaolo Bonzini { 3719b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 37206e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3721be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 37227f497775SDavid Matlack int quadrant, i, r; 37238123f265SSean Christopherson hpa_t root; 3724c50d8ae3SPaolo Bonzini 3725b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3726be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3727c50d8ae3SPaolo Bonzini 3728c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3729c50d8ae3SPaolo Bonzini return 1; 3730c50d8ae3SPaolo Bonzini 3731c50d8ae3SPaolo Bonzini /* 37324a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 37334a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 37344a38162eSPaolo Bonzini */ 37354d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 37366e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 37376e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 37386e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 37396e0918aeSSean Christopherson continue; 37406e0918aeSSean Christopherson 37416e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 37426e0918aeSSean Christopherson return 1; 37436e0918aeSSean Christopherson } 37446e0918aeSSean Christopherson } 37456e0918aeSSean Christopherson 37461e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3747d501f747SBen Gardon if (r) 3748d501f747SBen Gardon return r; 3749d501f747SBen Gardon 37504a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 37514a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 37524a38162eSPaolo Bonzini if (r < 0) 37534a38162eSPaolo Bonzini goto out_unlock; 37544a38162eSPaolo Bonzini 3755c50d8ae3SPaolo Bonzini /* 3756c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3757c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3758c50d8ae3SPaolo Bonzini */ 37594d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 37608123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 376186938ab6SDavid Matlack mmu->root_role.level); 3762b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3763be01e8e2SSean Christopherson goto set_root_pgd; 3764c50d8ae3SPaolo Bonzini } 3765c50d8ae3SPaolo Bonzini 37664a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 37674a38162eSPaolo Bonzini r = -EIO; 37684a38162eSPaolo Bonzini goto out_unlock; 37694a38162eSPaolo Bonzini } 377073ad1606SSean Christopherson 3771c50d8ae3SPaolo Bonzini /* 3772c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3773c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3774c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3775c50d8ae3SPaolo Bonzini */ 3776e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3777a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3778c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3779c50d8ae3SPaolo Bonzini 378003ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 37814a38162eSPaolo Bonzini r = -EIO; 37824a38162eSPaolo Bonzini goto out_unlock; 37834a38162eSPaolo Bonzini } 378403ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3785cb0f722aSWei Huang 3786a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3787cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3788cb0f722aSWei Huang r = -EIO; 3789cb0f722aSWei Huang goto out_unlock; 3790cb0f722aSWei Huang } 3791cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3792cb0f722aSWei Huang } 379304d45551SSean Christopherson } 379404d45551SSean Christopherson 3795c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3796c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 37976e6ec584SSean Christopherson 37984d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 37996e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3800c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3801c50d8ae3SPaolo Bonzini continue; 3802c50d8ae3SPaolo Bonzini } 38036e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3804c50d8ae3SPaolo Bonzini } 3805c50d8ae3SPaolo Bonzini 38067f497775SDavid Matlack /* 38077f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 38087f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 38097f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 38107f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 38117f497775SDavid Matlack */ 38127f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 38137f497775SDavid Matlack 38147f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3815b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3816c50d8ae3SPaolo Bonzini } 3817c50d8ae3SPaolo Bonzini 3818a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3819b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3820a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3821b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3822ba0a194fSSean Christopherson else 3823b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3824c50d8ae3SPaolo Bonzini 3825be01e8e2SSean Christopherson set_root_pgd: 3826b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 38274a38162eSPaolo Bonzini out_unlock: 38284a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3829c50d8ae3SPaolo Bonzini 3830c6c937d6SLike Xu return r; 3831c50d8ae3SPaolo Bonzini } 3832c50d8ae3SPaolo Bonzini 3833748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3834c50d8ae3SPaolo Bonzini { 3835748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3836a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3837cb0f722aSWei Huang u64 *pml5_root = NULL; 3838cb0f722aSWei Huang u64 *pml4_root = NULL; 3839cb0f722aSWei Huang u64 *pae_root; 3840748e52b9SSean Christopherson 3841748e52b9SSean Christopherson /* 3842748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3843748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3844748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3845748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3846748e52b9SSean Christopherson */ 3847347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3848347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3849a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3850748e52b9SSean Christopherson return 0; 3851748e52b9SSean Christopherson 3852a717a780SSean Christopherson /* 3853a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3854a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3855a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3856a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3857a717a780SSean Christopherson * prior MMU would also have required pml5. 3858a717a780SSean Christopherson */ 3859a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3860748e52b9SSean Christopherson return 0; 3861748e52b9SSean Christopherson 3862748e52b9SSean Christopherson /* 3863748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3864748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3865748e52b9SSean Christopherson */ 3866cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3867a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3868748e52b9SSean Christopherson return -EIO; 3869748e52b9SSean Christopherson 38704a98623dSSean Christopherson /* 38714a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 38724a98623dSSean Christopherson * doesn't need to be decrypted. 38734a98623dSSean Christopherson */ 3874748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3875748e52b9SSean Christopherson if (!pae_root) 3876748e52b9SSean Christopherson return -ENOMEM; 3877748e52b9SSean Christopherson 3878cb0f722aSWei Huang #ifdef CONFIG_X86_64 387903ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3880cb0f722aSWei Huang if (!pml4_root) 3881cb0f722aSWei Huang goto err_pml4; 3882cb0f722aSWei Huang 3883a717a780SSean Christopherson if (need_pml5) { 3884cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3885cb0f722aSWei Huang if (!pml5_root) 3886cb0f722aSWei Huang goto err_pml5; 3887748e52b9SSean Christopherson } 3888cb0f722aSWei Huang #endif 3889748e52b9SSean Christopherson 3890748e52b9SSean Christopherson mmu->pae_root = pae_root; 389103ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3892cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3893748e52b9SSean Christopherson 3894748e52b9SSean Christopherson return 0; 3895cb0f722aSWei Huang 3896cb0f722aSWei Huang #ifdef CONFIG_X86_64 3897cb0f722aSWei Huang err_pml5: 3898cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3899cb0f722aSWei Huang err_pml4: 3900cb0f722aSWei Huang free_page((unsigned long)pae_root); 3901cb0f722aSWei Huang return -ENOMEM; 3902cb0f722aSWei Huang #endif 3903c50d8ae3SPaolo Bonzini } 3904c50d8ae3SPaolo Bonzini 3905264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3906264d3dc1SLai Jiangshan { 3907264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3908264d3dc1SLai Jiangshan 390961b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 391061b05a9fSLai Jiangshan return false; 391161b05a9fSLai Jiangshan 3912264d3dc1SLai Jiangshan /* 3913264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3914264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3915264d3dc1SLai Jiangshan * 3916264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3917264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3918264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3919264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3920264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3921264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3922264d3dc1SLai Jiangshan * requirement isn't satisfied. 3923264d3dc1SLai Jiangshan */ 3924264d3dc1SLai Jiangshan smp_rmb(); 3925264d3dc1SLai Jiangshan sp = to_shadow_page(root); 39265d6a3221SSean Christopherson 39275d6a3221SSean Christopherson /* 39285d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 39295d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 39305d6a3221SSean Christopherson */ 39315d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 39325d6a3221SSean Christopherson return false; 39335d6a3221SSean Christopherson 3934264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3935264d3dc1SLai Jiangshan return true; 3936264d3dc1SLai Jiangshan 3937264d3dc1SLai Jiangshan return false; 3938264d3dc1SLai Jiangshan } 3939264d3dc1SLai Jiangshan 3940c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3941c50d8ae3SPaolo Bonzini { 3942c50d8ae3SPaolo Bonzini int i; 3943c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3944c50d8ae3SPaolo Bonzini 3945347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3946c50d8ae3SPaolo Bonzini return; 3947c50d8ae3SPaolo Bonzini 3948b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3949c50d8ae3SPaolo Bonzini return; 3950c50d8ae3SPaolo Bonzini 3951c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3952c50d8ae3SPaolo Bonzini 39534d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3954b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3955e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3956c50d8ae3SPaolo Bonzini 3957264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3958c50d8ae3SPaolo Bonzini return; 3959c50d8ae3SPaolo Bonzini 3960531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 396165855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3962531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3963c50d8ae3SPaolo Bonzini return; 3964c50d8ae3SPaolo Bonzini } 3965c50d8ae3SPaolo Bonzini 3966531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3967c50d8ae3SPaolo Bonzini 3968c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3969c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3970c50d8ae3SPaolo Bonzini 3971c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 39725e3edd7eSSean Christopherson sp = spte_to_child_sp(root); 397365855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3974c50d8ae3SPaolo Bonzini } 3975c50d8ae3SPaolo Bonzini } 3976c50d8ae3SPaolo Bonzini 3977531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3978c50d8ae3SPaolo Bonzini } 3979c50d8ae3SPaolo Bonzini 398061b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 398161b05a9fSLai Jiangshan { 398261b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 398361b05a9fSLai Jiangshan int i; 398461b05a9fSLai Jiangshan 398561b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 398661b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 398761b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 398861b05a9fSLai Jiangshan 398961b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 39900c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 399161b05a9fSLai Jiangshan } 399261b05a9fSLai Jiangshan 39931f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 39945b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3995c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3996c50d8ae3SPaolo Bonzini { 3997c50d8ae3SPaolo Bonzini if (exception) 3998c50d8ae3SPaolo Bonzini exception->error_code = 0; 3999c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 4000c50d8ae3SPaolo Bonzini } 4001c50d8ae3SPaolo Bonzini 4002c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4003c50d8ae3SPaolo Bonzini { 4004c50d8ae3SPaolo Bonzini /* 4005c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 4006c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 4007c50d8ae3SPaolo Bonzini */ 4008c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 4009c50d8ae3SPaolo Bonzini return false; 4010c50d8ae3SPaolo Bonzini 4011c50d8ae3SPaolo Bonzini if (direct) 4012c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 4013c50d8ae3SPaolo Bonzini 4014c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 4015c50d8ae3SPaolo Bonzini } 4016c50d8ae3SPaolo Bonzini 401795fb5b02SBen Gardon /* 401895fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 401995fb5b02SBen Gardon * That SPTE may be non-present. 4020c5c8c7c5SDavid Matlack * 4021c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 402295fb5b02SBen Gardon */ 402339b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 4024c50d8ae3SPaolo Bonzini { 4025c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 40262aa07893SSean Christopherson int leaf = -1; 402795fb5b02SBen Gardon u64 spte; 4028c50d8ae3SPaolo Bonzini 402939b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 403039b4d43eSSean Christopherson *root_level = iterator.level; 4031c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 4032c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 403395fb5b02SBen Gardon leaf = iterator.level; 4034c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 4035c50d8ae3SPaolo Bonzini 4036dde81f94SSean Christopherson sptes[leaf] = spte; 403795fb5b02SBen Gardon } 403895fb5b02SBen Gardon 403995fb5b02SBen Gardon return leaf; 404095fb5b02SBen Gardon } 404195fb5b02SBen Gardon 40429aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 404395fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 404495fb5b02SBen Gardon { 4045dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 404695fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 404739b4d43eSSean Christopherson int root, leaf, level; 404895fb5b02SBen Gardon bool reserved = false; 404995fb5b02SBen Gardon 4050c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 4051c5c8c7c5SDavid Matlack 405278fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) 405339b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 405495fb5b02SBen Gardon else 405539b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 405695fb5b02SBen Gardon 4057c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 4058c5c8c7c5SDavid Matlack 40592aa07893SSean Christopherson if (unlikely(leaf < 0)) { 40602aa07893SSean Christopherson *sptep = 0ull; 40612aa07893SSean Christopherson return reserved; 40622aa07893SSean Christopherson } 40632aa07893SSean Christopherson 40649aa41879SSean Christopherson *sptep = sptes[leaf]; 40659aa41879SSean Christopherson 40669aa41879SSean Christopherson /* 40679aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 40689aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 40699aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 40709aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 40719aa41879SSean Christopherson */ 40729aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 40739aa41879SSean Christopherson leaf++; 407495fb5b02SBen Gardon 407595fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 407695fb5b02SBen Gardon 40779aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4078961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4079c50d8ae3SPaolo Bonzini 4080c50d8ae3SPaolo Bonzini if (reserved) { 4081bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4082c50d8ae3SPaolo Bonzini __func__, addr); 408395fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4084bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4085bb4cdf3aSSean Christopherson sptes[level], level, 4086961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4087c50d8ae3SPaolo Bonzini } 4088ddce6208SSean Christopherson 4089c50d8ae3SPaolo Bonzini return reserved; 4090c50d8ae3SPaolo Bonzini } 4091c50d8ae3SPaolo Bonzini 4092c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4093c50d8ae3SPaolo Bonzini { 4094c50d8ae3SPaolo Bonzini u64 spte; 4095c50d8ae3SPaolo Bonzini bool reserved; 4096c50d8ae3SPaolo Bonzini 4097c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4098c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4099c50d8ae3SPaolo Bonzini 410095fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 4101c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 4102c50d8ae3SPaolo Bonzini return -EINVAL; 4103c50d8ae3SPaolo Bonzini 4104c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4105c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 41060a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4107c50d8ae3SPaolo Bonzini 4108c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4109c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4110c50d8ae3SPaolo Bonzini 4111c50d8ae3SPaolo Bonzini if (direct) 4112c50d8ae3SPaolo Bonzini addr = 0; 4113c50d8ae3SPaolo Bonzini 4114c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4115c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4116c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4117c50d8ae3SPaolo Bonzini } 4118c50d8ae3SPaolo Bonzini 4119c50d8ae3SPaolo Bonzini /* 4120c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4121c50d8ae3SPaolo Bonzini * the address. 4122c50d8ae3SPaolo Bonzini */ 4123c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4124c50d8ae3SPaolo Bonzini } 4125c50d8ae3SPaolo Bonzini 4126c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4127b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4128c50d8ae3SPaolo Bonzini { 4129b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4130c50d8ae3SPaolo Bonzini return false; 4131c50d8ae3SPaolo Bonzini 4132b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4133c50d8ae3SPaolo Bonzini return false; 4134c50d8ae3SPaolo Bonzini 4135c50d8ae3SPaolo Bonzini /* 4136c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4137c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4138c50d8ae3SPaolo Bonzini */ 41399d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 4140c50d8ae3SPaolo Bonzini return true; 4141c50d8ae3SPaolo Bonzini 4142c50d8ae3SPaolo Bonzini return false; 4143c50d8ae3SPaolo Bonzini } 4144c50d8ae3SPaolo Bonzini 4145c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4146c50d8ae3SPaolo Bonzini { 4147c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4148c50d8ae3SPaolo Bonzini u64 spte; 4149c50d8ae3SPaolo Bonzini 4150c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 41513e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4152c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4153c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4154c50d8ae3SPaolo Bonzini } 4155c50d8ae3SPaolo Bonzini 41566f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 41576f3c1fc5SLiang Zhang { 41586f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 41596f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 41606f3c1fc5SLiang Zhang 41616f3c1fc5SLiang Zhang if (id << 12 == 0) 41626f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 41636f3c1fc5SLiang Zhang 41646f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 41656f3c1fc5SLiang Zhang } 41666f3c1fc5SLiang Zhang 4167e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 41689f1a8526SSean Christopherson gfn_t gfn) 4169c50d8ae3SPaolo Bonzini { 4170c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4171c50d8ae3SPaolo Bonzini 41726f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4173c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4174347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 4175d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 4176c50d8ae3SPaolo Bonzini 41779f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 41789f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4179c50d8ae3SPaolo Bonzini } 4180c50d8ae3SPaolo Bonzini 41818a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 41828a009d5bSSean Christopherson { 41838a009d5bSSean Christopherson int r; 41848a009d5bSSean Christopherson 41858a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 41868a009d5bSSean Christopherson work->wakeup_all) 41878a009d5bSSean Christopherson return; 41888a009d5bSSean Christopherson 41898a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 41908a009d5bSSean Christopherson if (unlikely(r)) 41918a009d5bSSean Christopherson return; 41928a009d5bSSean Christopherson 41938a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 41948a009d5bSSean Christopherson work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu)) 41958a009d5bSSean Christopherson return; 41968a009d5bSSean Christopherson 41978a009d5bSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true); 41988a009d5bSSean Christopherson } 41998a009d5bSSean Christopherson 4200ba6e3fe2SDavid Matlack static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4201c50d8ae3SPaolo Bonzini { 4202e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4203c50d8ae3SPaolo Bonzini bool async; 4204c50d8ae3SPaolo Bonzini 4205e0c37868SSean Christopherson /* 4206e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4207e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4208e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4209e0c37868SSean Christopherson */ 4210e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 42115276c616SSean Christopherson return RET_PF_RETRY; 4212e0c37868SSean Christopherson 42139cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4214c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 42159cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4216e710c5f6SDavid Matlack fault->slot = NULL; 42173647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 42183647cd04SPaolo Bonzini fault->map_writable = false; 42195276c616SSean Christopherson return RET_PF_CONTINUE; 4220c50d8ae3SPaolo Bonzini } 42219cc13d60SMaxim Levitsky /* 42229cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 42239cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 42249cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 42259cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 42269cc13d60SMaxim Levitsky */ 42279cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 42285276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 42295276c616SSean Christopherson return RET_PF_EMULATE; 42309cc13d60SMaxim Levitsky } 4231c50d8ae3SPaolo Bonzini 4232c50d8ae3SPaolo Bonzini async = false; 4233c8b88b33SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, 42343647cd04SPaolo Bonzini fault->write, &fault->map_writable, 42353647cd04SPaolo Bonzini &fault->hva); 4236c50d8ae3SPaolo Bonzini if (!async) 42375276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4238c50d8ae3SPaolo Bonzini 42392839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 42403647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 42413647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 42421685c0f3SMingwei Zhang trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4243c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 42445276c616SSean Christopherson return RET_PF_RETRY; 42455276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 42465276c616SSean Christopherson return RET_PF_RETRY; 42475276c616SSean Christopherson } 4248c50d8ae3SPaolo Bonzini } 4249c50d8ae3SPaolo Bonzini 425076657687SPeter Xu /* 425176657687SPeter Xu * Allow gup to bail on pending non-fatal signals when it's also allowed 425276657687SPeter Xu * to wait for IO. Note, gup always bails if it is unable to quickly 425376657687SPeter Xu * get a page and a fatal signal, i.e. SIGKILL, is pending. 425476657687SPeter Xu */ 425576657687SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, 42563647cd04SPaolo Bonzini fault->write, &fault->map_writable, 42573647cd04SPaolo Bonzini &fault->hva); 42585276c616SSean Christopherson return RET_PF_CONTINUE; 4259c50d8ae3SPaolo Bonzini } 4260c50d8ae3SPaolo Bonzini 4261354c908cSDavid Matlack static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 4262354c908cSDavid Matlack unsigned int access) 4263ba6e3fe2SDavid Matlack { 426456c3a4e4SDavid Matlack int ret; 426556c3a4e4SDavid Matlack 4266ba6e3fe2SDavid Matlack fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4267ba6e3fe2SDavid Matlack smp_rmb(); 4268ba6e3fe2SDavid Matlack 426956c3a4e4SDavid Matlack ret = __kvm_faultin_pfn(vcpu, fault); 427056c3a4e4SDavid Matlack if (ret != RET_PF_CONTINUE) 427156c3a4e4SDavid Matlack return ret; 427256c3a4e4SDavid Matlack 427356c3a4e4SDavid Matlack if (unlikely(is_error_pfn(fault->pfn))) 4274cd08d178SDavid Matlack return kvm_handle_error_pfn(vcpu, fault); 427556c3a4e4SDavid Matlack 4276354c908cSDavid Matlack if (unlikely(!fault->slot)) 4277354c908cSDavid Matlack return kvm_handle_noslot_fault(vcpu, fault, access); 4278354c908cSDavid Matlack 427956c3a4e4SDavid Matlack return RET_PF_CONTINUE; 4280ba6e3fe2SDavid Matlack } 4281ba6e3fe2SDavid Matlack 4282a955cad8SSean Christopherson /* 4283a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4284a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4285a955cad8SSean Christopherson */ 4286a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4287ba6e3fe2SDavid Matlack struct kvm_page_fault *fault) 4288a955cad8SSean Christopherson { 4289b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 429018c841e1SSean Christopherson 429118c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 429218c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 429318c841e1SSean Christopherson return true; 429418c841e1SSean Christopherson 429518c841e1SSean Christopherson /* 429618c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 429718c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 429818c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 429918c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 430018c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 430118c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 430218c841e1SSean Christopherson */ 4303527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4304a955cad8SSean Christopherson return true; 4305a955cad8SSean Christopherson 4306a955cad8SSean Christopherson return fault->slot && 4307ba6e3fe2SDavid Matlack mmu_invalidate_retry_hva(vcpu->kvm, fault->mmu_seq, fault->hva); 4308a955cad8SSean Christopherson } 4309a955cad8SSean Christopherson 43104326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4311c50d8ae3SPaolo Bonzini { 431283f06fa7SSean Christopherson int r; 4313c50d8ae3SPaolo Bonzini 4314b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4315c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4316c50d8ae3SPaolo Bonzini 43173c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4318c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4319c4371c2aSSean Christopherson return r; 432083291445SSean Christopherson 4321378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4322c50d8ae3SPaolo Bonzini if (r) 4323c50d8ae3SPaolo Bonzini return r; 4324c50d8ae3SPaolo Bonzini 4325354c908cSDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 43265276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4327367fd790SSean Christopherson return r; 4328367fd790SSean Christopherson 4329367fd790SSean Christopherson r = RET_PF_RETRY; 4330531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4331a2855afcSBen Gardon 4332ba6e3fe2SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 4333367fd790SSean Christopherson goto out_unlock; 4334a955cad8SSean Christopherson 43357bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 43367bd7ded6SSean Christopherson if (r) 4337367fd790SSean Christopherson goto out_unlock; 4338bb18842eSBen Gardon 43396c882ef4SDavid Matlack r = direct_map(vcpu, fault); 43400f90e1c1SSean Christopherson 4341367fd790SSean Christopherson out_unlock: 4342531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 43433647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4344367fd790SSean Christopherson return r; 4345c50d8ae3SPaolo Bonzini } 4346c50d8ae3SPaolo Bonzini 4347c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4348c501040aSPaolo Bonzini struct kvm_page_fault *fault) 43490f90e1c1SSean Christopherson { 43504326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 43510f90e1c1SSean Christopherson 43520f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 43534326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 43544326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 43550f90e1c1SSean Christopherson } 43560f90e1c1SSean Christopherson 4357c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4358c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4359c50d8ae3SPaolo Bonzini { 4360c50d8ae3SPaolo Bonzini int r = 1; 43619ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4362c50d8ae3SPaolo Bonzini 4363736c291cSSean Christopherson #ifndef CONFIG_X86_64 4364736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4365736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4366736c291cSSean Christopherson return -EFAULT; 4367736c291cSSean Christopherson #endif 4368736c291cSSean Christopherson 4369c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 43709ce372b3SVitaly Kuznetsov if (!flags) { 4371faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4372c50d8ae3SPaolo Bonzini 4373c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4374c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4375c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4376c50d8ae3SPaolo Bonzini insn_len); 43779ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 437868fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4379c50d8ae3SPaolo Bonzini local_irq_disable(); 43806bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4381c50d8ae3SPaolo Bonzini local_irq_enable(); 43829ce372b3SVitaly Kuznetsov } else { 43839ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4384c50d8ae3SPaolo Bonzini } 43859ce372b3SVitaly Kuznetsov 4386c50d8ae3SPaolo Bonzini return r; 4387c50d8ae3SPaolo Bonzini } 4388c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4389c50d8ae3SPaolo Bonzini 43909aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 43919aa8ab43SDavid Matlack static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, 43929aa8ab43SDavid Matlack struct kvm_page_fault *fault) 43939aa8ab43SDavid Matlack { 43949aa8ab43SDavid Matlack int r; 43959aa8ab43SDavid Matlack 43969aa8ab43SDavid Matlack if (page_fault_handle_page_track(vcpu, fault)) 43979aa8ab43SDavid Matlack return RET_PF_EMULATE; 43989aa8ab43SDavid Matlack 43999aa8ab43SDavid Matlack r = fast_page_fault(vcpu, fault); 44009aa8ab43SDavid Matlack if (r != RET_PF_INVALID) 44019aa8ab43SDavid Matlack return r; 44029aa8ab43SDavid Matlack 44039aa8ab43SDavid Matlack r = mmu_topup_memory_caches(vcpu, false); 44049aa8ab43SDavid Matlack if (r) 44059aa8ab43SDavid Matlack return r; 44069aa8ab43SDavid Matlack 44079aa8ab43SDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 44089aa8ab43SDavid Matlack if (r != RET_PF_CONTINUE) 44099aa8ab43SDavid Matlack return r; 44109aa8ab43SDavid Matlack 44119aa8ab43SDavid Matlack r = RET_PF_RETRY; 44129aa8ab43SDavid Matlack read_lock(&vcpu->kvm->mmu_lock); 44139aa8ab43SDavid Matlack 44149aa8ab43SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 44159aa8ab43SDavid Matlack goto out_unlock; 44169aa8ab43SDavid Matlack 44179aa8ab43SDavid Matlack r = kvm_tdp_mmu_map(vcpu, fault); 44189aa8ab43SDavid Matlack 44199aa8ab43SDavid Matlack out_unlock: 44209aa8ab43SDavid Matlack read_unlock(&vcpu->kvm->mmu_lock); 44219aa8ab43SDavid Matlack kvm_release_pfn_clean(fault->pfn); 44229aa8ab43SDavid Matlack return r; 44239aa8ab43SDavid Matlack } 44249aa8ab43SDavid Matlack #endif 44259aa8ab43SDavid Matlack 4426c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4427c50d8ae3SPaolo Bonzini { 4428d5e90a69SSean Christopherson /* 4429d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4430d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 4431d5e90a69SSean Christopherson * across the entire mapping. If the host MTRRs are ignored by TDP 4432d5e90a69SSean Christopherson * (shadow_memtype_mask is non-zero), and the VM has non-coherent DMA 4433d5e90a69SSean Christopherson * (DMA doesn't snoop CPU caches), KVM's ABI is to honor the memtype 4434d5e90a69SSean Christopherson * from the guest's MTRRs so that guest accesses to memory that is 4435d5e90a69SSean Christopherson * DMA'd aren't cached against the guest's wishes. 4436d5e90a69SSean Christopherson * 4437d5e90a69SSean Christopherson * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 4438d5e90a69SSean Christopherson * e.g. KVM will force UC memtype for host MMIO. 4439d5e90a69SSean Christopherson */ 4440d5e90a69SSean Christopherson if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) { 4441d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 44424326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 4443e5e6f8d2SDavid Matlack gfn_t base = fault->gfn & ~(page_num - 1); 4444c50d8ae3SPaolo Bonzini 4445cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4446cb9b88c6SSean Christopherson break; 4447d5e90a69SSean Christopherson } 4448c50d8ae3SPaolo Bonzini } 4449c50d8ae3SPaolo Bonzini 44509aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 44519aa8ab43SDavid Matlack if (tdp_mmu_enabled) 44529aa8ab43SDavid Matlack return kvm_tdp_mmu_page_fault(vcpu, fault); 44539aa8ab43SDavid Matlack #endif 44549aa8ab43SDavid Matlack 44554326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4456c50d8ae3SPaolo Bonzini } 4457c50d8ae3SPaolo Bonzini 445884a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4459c50d8ae3SPaolo Bonzini { 4460c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4461c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4462c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 44635efac074SPaolo Bonzini context->invlpg = NULL; 4464c50d8ae3SPaolo Bonzini } 4465c50d8ae3SPaolo Bonzini 4466be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 44670be44352SSean Christopherson union kvm_mmu_page_role role) 44680be44352SSean Christopherson { 4469be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 44705499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4471e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 44720be44352SSean Christopherson } 44730be44352SSean Christopherson 4474c50d8ae3SPaolo Bonzini /* 44755499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 44765499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 44775499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 44785499ea73SPaolo Bonzini * true is returned. 44795499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 44805499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4481c50d8ae3SPaolo Bonzini */ 44825499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 44835499ea73SPaolo Bonzini gpa_t new_pgd, 4484c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4485c50d8ae3SPaolo Bonzini { 4486c50d8ae3SPaolo Bonzini uint i; 4487c50d8ae3SPaolo Bonzini 4488b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 44890be44352SSean Christopherson return true; 44900be44352SSean Christopherson 4491c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 44925499ea73SPaolo Bonzini /* 44935499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 44945499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 44955499ea73SPaolo Bonzini * 0 C 1 2 3 44965499ea73SPaolo Bonzini * 1 C 0 2 3 44975499ea73SPaolo Bonzini * 2 C 0 1 3 44985499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 44995499ea73SPaolo Bonzini */ 4500b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4501b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 45025499ea73SPaolo Bonzini return true; 4503c50d8ae3SPaolo Bonzini } 4504c50d8ae3SPaolo Bonzini 45055499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 45065499ea73SPaolo Bonzini return false; 4507c50d8ae3SPaolo Bonzini } 4508c50d8ae3SPaolo Bonzini 4509c50d8ae3SPaolo Bonzini /* 45105499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 45115499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 45125499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 45135499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 45145499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 45155499ea73SPaolo Bonzini */ 45165499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 45175499ea73SPaolo Bonzini gpa_t new_pgd, 45185499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 45195499ea73SPaolo Bonzini { 45205499ea73SPaolo Bonzini uint i; 45215499ea73SPaolo Bonzini 45225499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 45235499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 45245499ea73SPaolo Bonzini goto hit; 45255499ea73SPaolo Bonzini 45265499ea73SPaolo Bonzini return false; 45275499ea73SPaolo Bonzini 45285499ea73SPaolo Bonzini hit: 45295499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 45305499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 45315499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 45325499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 45335499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 45345499ea73SPaolo Bonzini return true; 45355499ea73SPaolo Bonzini } 45365499ea73SPaolo Bonzini 45375499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 45385499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 45395499ea73SPaolo Bonzini { 45405499ea73SPaolo Bonzini /* 45415499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4542c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4543c50d8ae3SPaolo Bonzini * later if necessary. 4544c50d8ae3SPaolo Bonzini */ 45455499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 45465499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4547c50d8ae3SPaolo Bonzini 45485499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 45495499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 45505499ea73SPaolo Bonzini else 45515499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4552c50d8ae3SPaolo Bonzini } 4553c50d8ae3SPaolo Bonzini 4554d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4555c50d8ae3SPaolo Bonzini { 45560c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 45577a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 45580c1c92f1SPaolo Bonzini 4559*a7e48ef7SWei Liu /* 4560*a7e48ef7SWei Liu * Return immediately if no usable root was found, kvm_mmu_reload() 4561*a7e48ef7SWei Liu * will establish a valid root prior to the next VM-Enter. 4562*a7e48ef7SWei Liu */ 4563*a7e48ef7SWei Liu if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) 4564b869855bSSean Christopherson return; 4565c50d8ae3SPaolo Bonzini 4566c50d8ae3SPaolo Bonzini /* 4567b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4568b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4569527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4570527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4571b869855bSSean Christopherson */ 4572b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4573b869855bSSean Christopherson 4574b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4575b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4576b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4577b5129100SSean Christopherson } 4578b869855bSSean Christopherson 4579b869855bSSean Christopherson /* 4580b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4581b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4582b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4583b869855bSSean Christopherson * the shadow page tables. 4584c50d8ae3SPaolo Bonzini */ 4585c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4586c50d8ae3SPaolo Bonzini 4587daa5b6c1SBen Gardon /* 4588daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4589daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4590daa5b6c1SBen Gardon */ 4591daa5b6c1SBen Gardon if (!new_role.direct) 4592daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4593b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4594c50d8ae3SPaolo Bonzini } 4595be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4596c50d8ae3SPaolo Bonzini 4597c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4598c50d8ae3SPaolo Bonzini { 4599c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4600c50d8ae3SPaolo Bonzini } 4601c50d8ae3SPaolo Bonzini 4602c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4603c3e5e415SLai Jiangshan unsigned int access) 4604c50d8ae3SPaolo Bonzini { 4605c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4606c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4607c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4608c50d8ae3SPaolo Bonzini return true; 4609c50d8ae3SPaolo Bonzini } 4610c50d8ae3SPaolo Bonzini 4611c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4612c50d8ae3SPaolo Bonzini return true; 4613c50d8ae3SPaolo Bonzini } 4614c50d8ae3SPaolo Bonzini 4615c50d8ae3SPaolo Bonzini return false; 4616c50d8ae3SPaolo Bonzini } 4617c50d8ae3SPaolo Bonzini 4618c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4619c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4620c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4621c50d8ae3SPaolo Bonzini #undef PTTYPE 4622c50d8ae3SPaolo Bonzini 4623c50d8ae3SPaolo Bonzini #define PTTYPE 64 4624c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4625c50d8ae3SPaolo Bonzini #undef PTTYPE 4626c50d8ae3SPaolo Bonzini 4627c50d8ae3SPaolo Bonzini #define PTTYPE 32 4628c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4629c50d8ae3SPaolo Bonzini #undef PTTYPE 4630c50d8ae3SPaolo Bonzini 4631c50d8ae3SPaolo Bonzini static void 4632b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 46335b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4634c50d8ae3SPaolo Bonzini bool pse, bool amd) 4635c50d8ae3SPaolo Bonzini { 4636c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4637c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 46385b7f575cSSean Christopherson u64 high_bits_rsvd; 4639c50d8ae3SPaolo Bonzini 4640c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4641c50d8ae3SPaolo Bonzini 4642c50d8ae3SPaolo Bonzini if (!gbpages) 4643c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4644c50d8ae3SPaolo Bonzini 46455b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 46465b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 46475b7f575cSSean Christopherson else 46485b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 46495b7f575cSSean Christopherson 46505b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 46515b7f575cSSean Christopherson if (!nx) 46525b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 46535b7f575cSSean Christopherson 4654c50d8ae3SPaolo Bonzini /* 4655c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4656c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4657c50d8ae3SPaolo Bonzini */ 4658c50d8ae3SPaolo Bonzini if (amd) 4659c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4660c50d8ae3SPaolo Bonzini 4661c50d8ae3SPaolo Bonzini switch (level) { 4662c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4663c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4664c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4665c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4666c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4667c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4668c50d8ae3SPaolo Bonzini 4669c50d8ae3SPaolo Bonzini if (!pse) { 4670c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4671c50d8ae3SPaolo Bonzini break; 4672c50d8ae3SPaolo Bonzini } 4673c50d8ae3SPaolo Bonzini 4674c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4675c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4676c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4677c50d8ae3SPaolo Bonzini else 4678c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4679c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4680c50d8ae3SPaolo Bonzini break; 4681c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 46825b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 46835b7f575cSSean Christopherson high_bits_rsvd | 46845b7f575cSSean Christopherson rsvd_bits(5, 8) | 46855b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 46865b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 46875b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 46885b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4689c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4690c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4691c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4692c50d8ae3SPaolo Bonzini break; 4693c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 46945b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 46955b7f575cSSean Christopherson nonleaf_bit8_rsvd | 46965b7f575cSSean Christopherson rsvd_bits(7, 7); 4697c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4698c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4699df561f66SGustavo A. R. Silva fallthrough; 4700c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 47015b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 47025b7f575cSSean Christopherson nonleaf_bit8_rsvd | 47035b7f575cSSean Christopherson rsvd_bits(7, 7); 47045b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 47055b7f575cSSean Christopherson gbpages_bit_rsvd; 47065b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 47075b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4708c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4709c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 47105b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 47115b7f575cSSean Christopherson gbpages_bit_rsvd | 4712c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 47135b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4714c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4715c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4716c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4717c50d8ae3SPaolo Bonzini break; 4718c50d8ae3SPaolo Bonzini } 4719c50d8ae3SPaolo Bonzini } 4720c50d8ae3SPaolo Bonzini 472127de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 472227de9250SSean Christopherson { 472327de9250SSean Christopherson /* 472427de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 472527de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 472627de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 472727de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 472827de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 472927de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 473027de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 473127de9250SSean Christopherson */ 473227de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 473327de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 473427de9250SSean Christopherson } 473527de9250SSean Christopherson 4736c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4737c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4738c50d8ae3SPaolo Bonzini { 4739b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 47405b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 47414d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 474227de9250SSean Christopherson guest_can_use_gbpages(vcpu), 47434e9c0d80SSean Christopherson is_cr4_pse(context), 474423493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4745c50d8ae3SPaolo Bonzini } 4746c50d8ae3SPaolo Bonzini 4747c50d8ae3SPaolo Bonzini static void 4748c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 474984ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4750c50d8ae3SPaolo Bonzini { 47515b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 475284ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4753c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4754c50d8ae3SPaolo Bonzini 475584ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 475684ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 475784ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 475884ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 475984ea5c09SLai Jiangshan 47605b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 47615b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 476284ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 476384ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 47645b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4765c50d8ae3SPaolo Bonzini 4766c50d8ae3SPaolo Bonzini /* large page */ 4767c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4768c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 476984ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 477084ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4771c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4772c50d8ae3SPaolo Bonzini 4773c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4774c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4775c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4776c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4777c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4778c50d8ae3SPaolo Bonzini if (!execonly) { 4779c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4780c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4781c50d8ae3SPaolo Bonzini } 4782c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4783c50d8ae3SPaolo Bonzini } 4784c50d8ae3SPaolo Bonzini 4785c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 478684ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4787c50d8ae3SPaolo Bonzini { 4788c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 478984ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 479084ea5c09SLai Jiangshan huge_page_level); 4791c50d8ae3SPaolo Bonzini } 4792c50d8ae3SPaolo Bonzini 47936f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 47946f8e65a6SSean Christopherson { 47956f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 47966f8e65a6SSean Christopherson } 47976f8e65a6SSean Christopherson 4798c50d8ae3SPaolo Bonzini /* 4799c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4800c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4801c50d8ae3SPaolo Bonzini * follow the features in guest. 4802c50d8ae3SPaolo Bonzini */ 480316be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 480416be1d12SSean Christopherson struct kvm_mmu *context) 4805c50d8ae3SPaolo Bonzini { 48068c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 48078c985b2dSSean Christopherson bool is_amd = true; 48088c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 48098c985b2dSSean Christopherson bool is_pse = false; 4810c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4811c50d8ae3SPaolo Bonzini int i; 4812c50d8ae3SPaolo Bonzini 4813a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 48148c985b2dSSean Christopherson 4815c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4816b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4817a972e29cSPaolo Bonzini context->root_role.level, 48187a458f0eSPaolo Bonzini context->root_role.efer_nx, 481927de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4820c50d8ae3SPaolo Bonzini 4821c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4822c50d8ae3SPaolo Bonzini return; 4823c50d8ae3SPaolo Bonzini 4824a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4825e54f1ff2SKai Huang /* 4826e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4827e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4828e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4829e54f1ff2SKai Huang * not allowed to be set. 4830e54f1ff2SKai Huang */ 4831e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4832e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4833e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4834e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4835c50d8ae3SPaolo Bonzini } 4836c50d8ae3SPaolo Bonzini 4837c50d8ae3SPaolo Bonzini } 4838c50d8ae3SPaolo Bonzini 4839c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4840c50d8ae3SPaolo Bonzini { 4841c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4842c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4843c50d8ae3SPaolo Bonzini } 4844c50d8ae3SPaolo Bonzini 4845c50d8ae3SPaolo Bonzini /* 4846c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4847c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4848c50d8ae3SPaolo Bonzini */ 4849c50d8ae3SPaolo Bonzini static void 4850e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4851c50d8ae3SPaolo Bonzini { 4852c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4853c50d8ae3SPaolo Bonzini int i; 4854c50d8ae3SPaolo Bonzini 4855c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4856c50d8ae3SPaolo Bonzini 4857c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4858b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 48596c6ab524SSean Christopherson context->root_role.level, true, 4860c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 48618c985b2dSSean Christopherson false, true); 4862c50d8ae3SPaolo Bonzini else 4863c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 486484ea5c09SLai Jiangshan reserved_hpa_bits(), false, 486584ea5c09SLai Jiangshan max_huge_page_level); 4866c50d8ae3SPaolo Bonzini 4867c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4868c50d8ae3SPaolo Bonzini return; 4869c50d8ae3SPaolo Bonzini 4870a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4871c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4872c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4873c50d8ae3SPaolo Bonzini } 4874c50d8ae3SPaolo Bonzini } 4875c50d8ae3SPaolo Bonzini 4876c50d8ae3SPaolo Bonzini /* 4877c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4878c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4879c50d8ae3SPaolo Bonzini */ 4880c50d8ae3SPaolo Bonzini static void 4881e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4882c50d8ae3SPaolo Bonzini { 4883c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 488484ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 488584ea5c09SLai Jiangshan max_huge_page_level); 4886c50d8ae3SPaolo Bonzini } 4887c50d8ae3SPaolo Bonzini 4888c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4889c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4890c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4891c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4892c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4893c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4894c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4895c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4896c50d8ae3SPaolo Bonzini 4897c50d8ae3SPaolo Bonzini 4898c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4899c50d8ae3SPaolo Bonzini { 4900c50d8ae3SPaolo Bonzini unsigned byte; 4901c50d8ae3SPaolo Bonzini 4902c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4903c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4904c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4905c50d8ae3SPaolo Bonzini 4906c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4907c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4908c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 490990599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4910c50d8ae3SPaolo Bonzini 4911c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4912c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4913c50d8ae3SPaolo Bonzini 4914c50d8ae3SPaolo Bonzini /* 4915c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4916c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4917c50d8ae3SPaolo Bonzini */ 4918c50d8ae3SPaolo Bonzini 4919c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4920c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4921c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4922c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4923c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4924c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4925c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4926c50d8ae3SPaolo Bonzini u8 smepf = 0; 4927c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4928c50d8ae3SPaolo Bonzini u8 smapf = 0; 4929c50d8ae3SPaolo Bonzini 4930c50d8ae3SPaolo Bonzini if (!ept) { 4931c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4932c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4933c50d8ae3SPaolo Bonzini 4934c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 493590599c28SSean Christopherson if (!efer_nx) 4936c50d8ae3SPaolo Bonzini ff = 0; 4937c50d8ae3SPaolo Bonzini 4938c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4939c50d8ae3SPaolo Bonzini if (!cr0_wp) 4940c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4941c50d8ae3SPaolo Bonzini 4942c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4943c50d8ae3SPaolo Bonzini if (cr4_smep) 4944c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4945c50d8ae3SPaolo Bonzini 4946c50d8ae3SPaolo Bonzini /* 4947c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4948c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4949c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4950c50d8ae3SPaolo Bonzini * conditions are true: 4951c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4952c50d8ae3SPaolo Bonzini * - A user page is accessed 4953c50d8ae3SPaolo Bonzini * - The access is not a fetch 49544f4aa80eSLai Jiangshan * - The access is supervisor mode 49554f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4956c50d8ae3SPaolo Bonzini * 495794b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 495894b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4959c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4960c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4961c50d8ae3SPaolo Bonzini */ 4962c50d8ae3SPaolo Bonzini if (cr4_smap) 4963c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4964c50d8ae3SPaolo Bonzini } 4965c50d8ae3SPaolo Bonzini 4966c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4967c50d8ae3SPaolo Bonzini } 4968c50d8ae3SPaolo Bonzini } 4969c50d8ae3SPaolo Bonzini 4970c50d8ae3SPaolo Bonzini /* 4971c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4972c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4973c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4974c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4975c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4976c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4977c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4978c50d8ae3SPaolo Bonzini * 4979c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4980c50d8ae3SPaolo Bonzini * page tables and the machine state: 4981c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4982c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4983c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4984c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4985c50d8ae3SPaolo Bonzini * 4986c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4987c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4988c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4989c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4990c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4991c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4992c50d8ae3SPaolo Bonzini * only will be masked away. 4993c50d8ae3SPaolo Bonzini */ 49942e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4995c50d8ae3SPaolo Bonzini { 4996c50d8ae3SPaolo Bonzini unsigned bit; 4997c50d8ae3SPaolo Bonzini bool wp; 4998c50d8ae3SPaolo Bonzini 4999c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 5000a3ca5281SChenyi Qiang 5001a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 5002c50d8ae3SPaolo Bonzini return; 5003c50d8ae3SPaolo Bonzini 50042e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 5005c50d8ae3SPaolo Bonzini 5006c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 5007c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 5008c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 5009c50d8ae3SPaolo Bonzini 5010c50d8ae3SPaolo Bonzini pfec = bit << 1; 5011c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 5012c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 5013c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 5014c50d8ae3SPaolo Bonzini 5015c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 5016c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 5017c50d8ae3SPaolo Bonzini 5018c50d8ae3SPaolo Bonzini /* 5019c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 5020c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 5021c50d8ae3SPaolo Bonzini */ 5022c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 5023c50d8ae3SPaolo Bonzini /* 5024c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 5025c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 5026c50d8ae3SPaolo Bonzini */ 5027c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 5028c50d8ae3SPaolo Bonzini 5029c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 5030c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 5031c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 5032c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 5033c50d8ae3SPaolo Bonzini 5034c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 5035c50d8ae3SPaolo Bonzini } 5036c50d8ae3SPaolo Bonzini } 5037c50d8ae3SPaolo Bonzini 5038533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 5039533f9a4bSSean Christopherson struct kvm_mmu *mmu) 5040c50d8ae3SPaolo Bonzini { 5041533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 5042533f9a4bSSean Christopherson return; 5043c50d8ae3SPaolo Bonzini 5044c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 5045533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 5046533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 5047c50d8ae3SPaolo Bonzini } 5048c50d8ae3SPaolo Bonzini 5049fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 5050c50d8ae3SPaolo Bonzini { 5051c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 5052c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5053c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 5054c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 5055c50d8ae3SPaolo Bonzini } 5056c50d8ae3SPaolo Bonzini 505784a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 5058c50d8ae3SPaolo Bonzini { 5059c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 5060c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5061c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 5062c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 5063c50d8ae3SPaolo Bonzini } 5064c50d8ae3SPaolo Bonzini 50657a7ae829SPaolo Bonzini static union kvm_cpu_role 5066e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 5067e5ed0fb0SPaolo Bonzini { 50687a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5069e5ed0fb0SPaolo Bonzini 5070e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 5071e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 5072e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 5073e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 5074e5ed0fb0SPaolo Bonzini 5075e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 5076e5ed0fb0SPaolo Bonzini role.base.direct = 1; 5077e5ed0fb0SPaolo Bonzini return role; 5078e5ed0fb0SPaolo Bonzini } 5079e5ed0fb0SPaolo Bonzini 5080e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 5081e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 5082e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 5083e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 5084e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 508560f3cb60SPaolo Bonzini 508660f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 508760f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 508860f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 508960f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 509060f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 509160f3cb60SPaolo Bonzini else 509260f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 5093e5ed0fb0SPaolo Bonzini 5094e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 5095e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 5096e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 5097e5ed0fb0SPaolo Bonzini 5098e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 5099e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 5100e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 5101e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 5102e5ed0fb0SPaolo Bonzini return role; 5103e5ed0fb0SPaolo Bonzini } 5104e5ed0fb0SPaolo Bonzini 5105d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 5106d468d94bSSean Christopherson { 5107746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5108746700d2SWei Huang if (tdp_root_level) 5109746700d2SWei Huang return tdp_root_level; 5110746700d2SWei Huang 5111d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 511283013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5113d468d94bSSean Christopherson return 4; 5114d468d94bSSean Christopherson 511583013059SSean Christopherson return max_tdp_level; 5116d468d94bSSean Christopherson } 5117d468d94bSSean Christopherson 51187a458f0eSPaolo Bonzini static union kvm_mmu_page_role 51198626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 51207a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5121c50d8ae3SPaolo Bonzini { 51227a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5123c50d8ae3SPaolo Bonzini 51247a458f0eSPaolo Bonzini role.access = ACC_ALL; 51257a458f0eSPaolo Bonzini role.cr0_wp = true; 51267a458f0eSPaolo Bonzini role.efer_nx = true; 51277a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 51287a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 512954275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 51307a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 51317a458f0eSPaolo Bonzini role.direct = true; 51327a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5133c50d8ae3SPaolo Bonzini 5134c50d8ae3SPaolo Bonzini return role; 5135c50d8ae3SPaolo Bonzini } 5136c50d8ae3SPaolo Bonzini 513739e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5138a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5139c50d8ae3SPaolo Bonzini { 51408c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 51417a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5142c50d8ae3SPaolo Bonzini 5143e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 51447a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5145c50d8ae3SPaolo Bonzini return; 5146c50d8ae3SPaolo Bonzini 5147e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 51487a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 51497a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5150c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 51515efac074SPaolo Bonzini context->invlpg = NULL; 5152d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5153c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5154c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5155c50d8ae3SPaolo Bonzini 515636f26787SSean Christopherson if (!is_cr0_pg(context)) 5157c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 515836f26787SSean Christopherson else if (is_cr4_pae(context)) 5159c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5160f4bd6f73SSean Christopherson else 5161c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5162c50d8ae3SPaolo Bonzini 5163533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5164e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5165c50d8ae3SPaolo Bonzini } 5166c50d8ae3SPaolo Bonzini 51678c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 51687a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 51697a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5170c50d8ae3SPaolo Bonzini { 5171e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 51727a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 517318db1b17SSean Christopherson return; 5174c50d8ae3SPaolo Bonzini 5175e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 51767a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 517718db1b17SSean Christopherson 517836f26787SSean Christopherson if (!is_cr0_pg(context)) 517984a16226SSean Christopherson nonpaging_init_context(context); 518036f26787SSean Christopherson else if (is_cr4_pae(context)) 5181fe660f72SSean Christopherson paging64_init_context(context); 5182c50d8ae3SPaolo Bonzini else 518384a16226SSean Christopherson paging32_init_context(context); 5184c50d8ae3SPaolo Bonzini 5185533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5186c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5187c50d8ae3SPaolo Bonzini } 51880f04a2acSVitaly Kuznetsov 5189594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5190a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 51910f04a2acSVitaly Kuznetsov { 51928c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 519356b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 519456b321f9SPaolo Bonzini 519556b321f9SPaolo Bonzini root_role = cpu_role.base; 519656b321f9SPaolo Bonzini 519756b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 519856b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 519956b321f9SPaolo Bonzini 520056b321f9SPaolo Bonzini /* 520156b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 520256b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 520356b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 520456b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 520556b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 520656b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 520756b321f9SPaolo Bonzini * MMU contexts. 520856b321f9SPaolo Bonzini */ 520956b321f9SPaolo Bonzini root_role.efer_nx = true; 52100f04a2acSVitaly Kuznetsov 52117a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 52120f04a2acSVitaly Kuznetsov } 52130f04a2acSVitaly Kuznetsov 5214dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5215dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 52160f04a2acSVitaly Kuznetsov { 52178c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5218594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5219594e91a1SSean Christopherson .cr0 = cr0, 522028f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5221594e91a1SSean Christopherson .efer = efer, 5222594e91a1SSean Christopherson }; 52237a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 522456b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 522556b321f9SPaolo Bonzini 522656b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 522756b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 522856b321f9SPaolo Bonzini 522956b321f9SPaolo Bonzini root_role = cpu_role.base; 523056b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 523184e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 523284e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 523384e5ffd0SLai Jiangshan root_role.passthrough = 1; 52340f04a2acSVitaly Kuznetsov 52357a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5236d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 52370f04a2acSVitaly Kuznetsov } 52380f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5239c50d8ae3SPaolo Bonzini 52407a7ae829SPaolo Bonzini static union kvm_cpu_role 5241c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5242bb1fcc70SSean Christopherson bool execonly, u8 level) 5243c50d8ae3SPaolo Bonzini { 52447a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5245c50d8ae3SPaolo Bonzini 5246daed87b8SPaolo Bonzini /* 5247daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5248daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5249daed87b8SPaolo Bonzini */ 5250daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5251bb1fcc70SSean Christopherson role.base.level = level; 5252bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5253c50d8ae3SPaolo Bonzini role.base.direct = false; 5254c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5255c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5256c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5257c50d8ae3SPaolo Bonzini 5258cd6767c3SSean Christopherson role.ext.word = 0; 5259c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5260cd6767c3SSean Christopherson role.ext.valid = 1; 5261c50d8ae3SPaolo Bonzini 5262c50d8ae3SPaolo Bonzini return role; 5263c50d8ae3SPaolo Bonzini } 5264c50d8ae3SPaolo Bonzini 5265c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5266cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5267cc022ae1SLai Jiangshan gpa_t new_eptp) 5268c50d8ae3SPaolo Bonzini { 52698c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5270bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 52717a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5272c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5273bb1fcc70SSean Christopherson execonly, level); 5274c50d8ae3SPaolo Bonzini 5275e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5276e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5277e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 52787a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 527918db1b17SSean Christopherson 5280c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5281c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5282c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 5283c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 5284347a0d0dSPaolo Bonzini 5285c596f147SSean Christopherson update_permission_bitmask(context, true); 528628f091bcSPaolo Bonzini context->pkru_mask = 0; 5287cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5288e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5289c50d8ae3SPaolo Bonzini } 52903cffc89dSPaolo Bonzini 5291d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 52923cffc89dSPaolo Bonzini } 5293c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5294c50d8ae3SPaolo Bonzini 529539e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5296a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5297c50d8ae3SPaolo Bonzini { 52988c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5299c50d8ae3SPaolo Bonzini 5300a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5301929d1cfaSPaolo Bonzini 5302d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5303c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5304c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5305c50d8ae3SPaolo Bonzini } 5306c50d8ae3SPaolo Bonzini 530739e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5308a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5309c50d8ae3SPaolo Bonzini { 5310c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5311c50d8ae3SPaolo Bonzini 5312e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5313c50d8ae3SPaolo Bonzini return; 5314c50d8ae3SPaolo Bonzini 5315e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5316d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5317c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5318c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5319c50d8ae3SPaolo Bonzini 5320c50d8ae3SPaolo Bonzini /* 53215efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 53225efac074SPaolo Bonzini * SPTEs. 53235efac074SPaolo Bonzini */ 53245efac074SPaolo Bonzini g_context->invlpg = NULL; 53255efac074SPaolo Bonzini 53265efac074SPaolo Bonzini /* 5327c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5328c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5329c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5330c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5331c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5332c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5333c50d8ae3SPaolo Bonzini */ 5334fa4b5588SSean Christopherson if (!is_paging(vcpu)) 53351f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5336fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 53371f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5338fa4b5588SSean Christopherson else if (is_pae(vcpu)) 53391f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5340fa4b5588SSean Christopherson else 53411f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5342fa4b5588SSean Christopherson 5343533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5344c50d8ae3SPaolo Bonzini } 5345c50d8ae3SPaolo Bonzini 5346c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5347c50d8ae3SPaolo Bonzini { 534839e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5349a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 535039e7e2bfSPaolo Bonzini 5351c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5352a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5353c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5354a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5355c50d8ae3SPaolo Bonzini else 5356a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5357c50d8ae3SPaolo Bonzini } 5358c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5359c50d8ae3SPaolo Bonzini 536049c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 536149c6f875SSean Christopherson { 536249c6f875SSean Christopherson /* 536349c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 536449c6f875SSean Christopherson * information is factored into reserved bit calculations. 5365feb627e8SVitaly Kuznetsov * 5366feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5367feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5368feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5369feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5370feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5371feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5372feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 537349c6f875SSean Christopherson */ 53747a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 53757a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 53767a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5377e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5378e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5379e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 538049c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 538163f5a190SSean Christopherson 538263f5a190SSean Christopherson /* 5383feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5384feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 538563f5a190SSean Christopherson */ 5386feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 538749c6f875SSean Christopherson } 538849c6f875SSean Christopherson 5389c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5390c50d8ae3SPaolo Bonzini { 5391c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5392c9060662SSean Christopherson kvm_init_mmu(vcpu); 5393c50d8ae3SPaolo Bonzini } 5394c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5395c50d8ae3SPaolo Bonzini 5396c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5397c50d8ae3SPaolo Bonzini { 5398c50d8ae3SPaolo Bonzini int r; 5399c50d8ae3SPaolo Bonzini 5400347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5401c50d8ae3SPaolo Bonzini if (r) 5402c50d8ae3SPaolo Bonzini goto out; 5403748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5404c50d8ae3SPaolo Bonzini if (r) 5405c50d8ae3SPaolo Bonzini goto out; 5406347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 54076e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 54086e6ec584SSean Christopherson else 54096e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5410c50d8ae3SPaolo Bonzini if (r) 5411c50d8ae3SPaolo Bonzini goto out; 5412a91f387bSSean Christopherson 5413a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5414a91f387bSSean Christopherson 5415727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5416db01416bSSean Christopherson 5417db01416bSSean Christopherson /* 5418db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5419db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5420db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5421db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5422db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5423db01416bSSean Christopherson */ 5424e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5425c50d8ae3SPaolo Bonzini out: 5426c50d8ae3SPaolo Bonzini return r; 5427c50d8ae3SPaolo Bonzini } 5428c50d8ae3SPaolo Bonzini 5429c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5430c50d8ae3SPaolo Bonzini { 54310c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 54320c1c92f1SPaolo Bonzini 54330c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5434b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 54350c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5436b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 54376d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5438c50d8ae3SPaolo Bonzini } 5439c50d8ae3SPaolo Bonzini 5440527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5441527d5cd7SSean Christopherson { 5442527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5443527d5cd7SSean Christopherson 5444527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5445527d5cd7SSean Christopherson return false; 5446527d5cd7SSean Christopherson 5447527d5cd7SSean Christopherson /* 5448527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5449527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5450527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5451527d5cd7SSean Christopherson * such false positives are relatively rare: 5452527d5cd7SSean Christopherson * 5453527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5454527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5455527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5456527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5457527d5cd7SSean Christopherson */ 5458527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5459527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5460527d5cd7SSean Christopherson } 5461527d5cd7SSean Christopherson 5462527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5463527d5cd7SSean Christopherson { 5464527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5465527d5cd7SSean Christopherson int i; 5466527d5cd7SSean Christopherson 5467527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5468527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5469527d5cd7SSean Christopherson 5470527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5471cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5472527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5473527d5cd7SSean Christopherson } 5474527d5cd7SSean Christopherson 5475527d5cd7SSean Christopherson if (roots_to_free) 5476527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5477527d5cd7SSean Christopherson } 5478527d5cd7SSean Christopherson 5479527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5480527d5cd7SSean Christopherson { 5481527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5482527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5483527d5cd7SSean Christopherson } 5484527d5cd7SSean Christopherson 5485c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5486c50d8ae3SPaolo Bonzini int *bytes) 5487c50d8ae3SPaolo Bonzini { 5488c50d8ae3SPaolo Bonzini u64 gentry = 0; 5489c50d8ae3SPaolo Bonzini int r; 5490c50d8ae3SPaolo Bonzini 5491c50d8ae3SPaolo Bonzini /* 5492c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5493c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5494c50d8ae3SPaolo Bonzini * when they have the same mode. 5495c50d8ae3SPaolo Bonzini */ 5496c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5497c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5498c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5499c50d8ae3SPaolo Bonzini *bytes = 8; 5500c50d8ae3SPaolo Bonzini } 5501c50d8ae3SPaolo Bonzini 5502c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5503c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5504c50d8ae3SPaolo Bonzini if (r) 5505c50d8ae3SPaolo Bonzini gentry = 0; 5506c50d8ae3SPaolo Bonzini } 5507c50d8ae3SPaolo Bonzini 5508c50d8ae3SPaolo Bonzini return gentry; 5509c50d8ae3SPaolo Bonzini } 5510c50d8ae3SPaolo Bonzini 5511c50d8ae3SPaolo Bonzini /* 5512c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5513c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5514c50d8ae3SPaolo Bonzini */ 5515c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5516c50d8ae3SPaolo Bonzini { 5517c50d8ae3SPaolo Bonzini /* 5518c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5519c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5520c50d8ae3SPaolo Bonzini */ 55213bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5522c50d8ae3SPaolo Bonzini return false; 5523c50d8ae3SPaolo Bonzini 5524c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5525c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5526c50d8ae3SPaolo Bonzini } 5527c50d8ae3SPaolo Bonzini 5528c50d8ae3SPaolo Bonzini /* 5529c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5530c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5531c50d8ae3SPaolo Bonzini */ 5532c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5533c50d8ae3SPaolo Bonzini int bytes) 5534c50d8ae3SPaolo Bonzini { 5535c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5536c50d8ae3SPaolo Bonzini 5537c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5538c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5539c50d8ae3SPaolo Bonzini 5540c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5541bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5542c50d8ae3SPaolo Bonzini 5543c50d8ae3SPaolo Bonzini /* 5544c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5545c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5546c50d8ae3SPaolo Bonzini */ 5547c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5548c50d8ae3SPaolo Bonzini return false; 5549c50d8ae3SPaolo Bonzini 5550c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5551c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5552c50d8ae3SPaolo Bonzini 5553c50d8ae3SPaolo Bonzini return misaligned; 5554c50d8ae3SPaolo Bonzini } 5555c50d8ae3SPaolo Bonzini 5556c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5557c50d8ae3SPaolo Bonzini { 5558c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5559c50d8ae3SPaolo Bonzini u64 *spte; 5560c50d8ae3SPaolo Bonzini int level; 5561c50d8ae3SPaolo Bonzini 5562c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5563c50d8ae3SPaolo Bonzini level = sp->role.level; 5564c50d8ae3SPaolo Bonzini *nspte = 1; 5565bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5566c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5567c50d8ae3SPaolo Bonzini /* 5568c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5569c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5570c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5571c50d8ae3SPaolo Bonzini */ 5572c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5573c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5574c50d8ae3SPaolo Bonzini page_offset <<= 1; 5575c50d8ae3SPaolo Bonzini *nspte = 2; 5576c50d8ae3SPaolo Bonzini } 5577c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5578c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5579c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5580c50d8ae3SPaolo Bonzini return NULL; 5581c50d8ae3SPaolo Bonzini } 5582c50d8ae3SPaolo Bonzini 5583c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5584c50d8ae3SPaolo Bonzini return spte; 5585c50d8ae3SPaolo Bonzini } 5586c50d8ae3SPaolo Bonzini 5587c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5588c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5589c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5590c50d8ae3SPaolo Bonzini { 5591c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5592c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5593c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5594c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5595c50d8ae3SPaolo Bonzini int npte; 559606152b2dSLai Jiangshan bool flush = false; 5597c50d8ae3SPaolo Bonzini 5598c50d8ae3SPaolo Bonzini /* 5599c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5600c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5601c50d8ae3SPaolo Bonzini */ 5602c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5603c50d8ae3SPaolo Bonzini return; 5604c50d8ae3SPaolo Bonzini 5605c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5606c50d8ae3SPaolo Bonzini 5607531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5608c50d8ae3SPaolo Bonzini 5609c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5610c50d8ae3SPaolo Bonzini 5611c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5612c50d8ae3SPaolo Bonzini 5613767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5614c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5615c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5616c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5617c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5618c50d8ae3SPaolo Bonzini continue; 5619c50d8ae3SPaolo Bonzini } 5620c50d8ae3SPaolo Bonzini 5621c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5622c50d8ae3SPaolo Bonzini if (!spte) 5623c50d8ae3SPaolo Bonzini continue; 5624c50d8ae3SPaolo Bonzini 5625c50d8ae3SPaolo Bonzini while (npte--) { 5626c50d8ae3SPaolo Bonzini entry = *spte; 56272de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5628c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5629c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 56301441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 563106152b2dSLai Jiangshan flush = true; 5632c50d8ae3SPaolo Bonzini ++spte; 5633c50d8ae3SPaolo Bonzini } 5634c50d8ae3SPaolo Bonzini } 563506152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5636531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5637c50d8ae3SPaolo Bonzini } 5638c50d8ae3SPaolo Bonzini 56391075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5640c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5641c50d8ae3SPaolo Bonzini { 564292daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5643347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5644c50d8ae3SPaolo Bonzini 5645b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5646ddce6208SSean Christopherson return RET_PF_RETRY; 5647ddce6208SSean Christopherson 5648c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5649c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5650736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5651c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5652c50d8ae3SPaolo Bonzini goto emulate; 5653c50d8ae3SPaolo Bonzini } 5654c50d8ae3SPaolo Bonzini 5655c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 56567a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 56577a02674dSSean Christopherson lower_32_bits(error_code), false); 565819025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 56597b367bc9SSean Christopherson return -EIO; 5660c50d8ae3SPaolo Bonzini } 5661c50d8ae3SPaolo Bonzini 5662c50d8ae3SPaolo Bonzini if (r < 0) 5663c50d8ae3SPaolo Bonzini return r; 566483a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 566583a2ba4cSSean Christopherson return 1; 5666c50d8ae3SPaolo Bonzini 5667c50d8ae3SPaolo Bonzini /* 5668c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5669c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5670c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5671c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5672c50d8ae3SPaolo Bonzini * and resume the guest. 5673c50d8ae3SPaolo Bonzini */ 5674347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5675c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5676736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5677c50d8ae3SPaolo Bonzini return 1; 5678c50d8ae3SPaolo Bonzini } 5679c50d8ae3SPaolo Bonzini 5680c50d8ae3SPaolo Bonzini /* 5681c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5682c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5683c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5684c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5685c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5686c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5687c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5688c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5689c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5690c50d8ae3SPaolo Bonzini */ 5691736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 569292daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5693c50d8ae3SPaolo Bonzini emulate: 5694736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5695c50d8ae3SPaolo Bonzini insn_len); 5696c50d8ae3SPaolo Bonzini } 5697c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5698c50d8ae3SPaolo Bonzini 56995efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 57005efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5701c50d8ae3SPaolo Bonzini { 5702c50d8ae3SPaolo Bonzini int i; 5703c50d8ae3SPaolo Bonzini 57045efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 57055efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 57065efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5707c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5708c50d8ae3SPaolo Bonzini return; 5709c50d8ae3SPaolo Bonzini 5710e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 57115efac074SPaolo Bonzini } 57125efac074SPaolo Bonzini 57135efac074SPaolo Bonzini if (!mmu->invlpg) 57145efac074SPaolo Bonzini return; 57155efac074SPaolo Bonzini 57165efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5717b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5718c50d8ae3SPaolo Bonzini 5719c50d8ae3SPaolo Bonzini /* 5720c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5721c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5722c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5723c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5724c50d8ae3SPaolo Bonzini * just always sync it. 5725c50d8ae3SPaolo Bonzini * 5726c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5727c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5728c50d8ae3SPaolo Bonzini * for them. 5729c50d8ae3SPaolo Bonzini */ 5730c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5731c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5732c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 57335efac074SPaolo Bonzini } else { 57345efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 57355efac074SPaolo Bonzini } 57365efac074SPaolo Bonzini } 5737c50d8ae3SPaolo Bonzini 57385efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 57395efac074SPaolo Bonzini { 574005b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5741c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5742c50d8ae3SPaolo Bonzini } 5743c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5744c50d8ae3SPaolo Bonzini 57455efac074SPaolo Bonzini 5746c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5747c50d8ae3SPaolo Bonzini { 5748c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5749c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5750c50d8ae3SPaolo Bonzini uint i; 5751c50d8ae3SPaolo Bonzini 5752c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 57539f46c187SPaolo Bonzini if (mmu->invlpg) 5754b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5755c50d8ae3SPaolo Bonzini tlb_flush = true; 5756c50d8ae3SPaolo Bonzini } 5757c50d8ae3SPaolo Bonzini 5758c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5759c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5760be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 57619f46c187SPaolo Bonzini if (mmu->invlpg) 5762c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5763c50d8ae3SPaolo Bonzini tlb_flush = true; 5764c50d8ae3SPaolo Bonzini } 5765c50d8ae3SPaolo Bonzini } 5766c50d8ae3SPaolo Bonzini 5767c50d8ae3SPaolo Bonzini if (tlb_flush) 5768e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5769c50d8ae3SPaolo Bonzini 5770c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5771c50d8ae3SPaolo Bonzini 5772c50d8ae3SPaolo Bonzini /* 5773c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5774c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5775c50d8ae3SPaolo Bonzini * for them. 5776c50d8ae3SPaolo Bonzini */ 5777c50d8ae3SPaolo Bonzini } 5778c50d8ae3SPaolo Bonzini 5779746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5780746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5781c50d8ae3SPaolo Bonzini { 5782bde77235SSean Christopherson tdp_enabled = enable_tdp; 5783746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 578483013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5785703c335dSSean Christopherson 57861f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 57871f98f2bdSDavid Matlack tdp_mmu_enabled = tdp_mmu_allowed && tdp_enabled; 57881f98f2bdSDavid Matlack #endif 5789703c335dSSean Christopherson /* 57901d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5791703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5792703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5793703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5794703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5795703c335dSSean Christopherson */ 5796703c335dSSean Christopherson if (tdp_enabled) 57971d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5798703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 57991d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5800703c335dSSean Christopherson else 58011d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5802c50d8ae3SPaolo Bonzini } 5803bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5804c50d8ae3SPaolo Bonzini 5805c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5806269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5807269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5808269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5809c50d8ae3SPaolo Bonzini 5810c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5811c50d8ae3SPaolo Bonzini static __always_inline bool 5812269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5813c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 58141a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 58151a61b7dbSSean Christopherson bool flush) 5816c50d8ae3SPaolo Bonzini { 5817c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5818c50d8ae3SPaolo Bonzini 5819c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5820c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5821c50d8ae3SPaolo Bonzini if (iterator.rmap) 58220a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5823c50d8ae3SPaolo Bonzini 5824531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5825302695a5SSean Christopherson if (flush && flush_on_yield) { 5826c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5827c50d8ae3SPaolo Bonzini start_gfn, 5828c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5829c50d8ae3SPaolo Bonzini flush = false; 5830c50d8ae3SPaolo Bonzini } 5831531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5832c50d8ae3SPaolo Bonzini } 5833c50d8ae3SPaolo Bonzini } 5834c50d8ae3SPaolo Bonzini 5835c50d8ae3SPaolo Bonzini return flush; 5836c50d8ae3SPaolo Bonzini } 5837c50d8ae3SPaolo Bonzini 5838c50d8ae3SPaolo Bonzini static __always_inline bool 5839269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5840c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5841302695a5SSean Christopherson bool flush_on_yield) 5842c50d8ae3SPaolo Bonzini { 5843c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5844c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5845c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 58461a61b7dbSSean Christopherson flush_on_yield, false); 5847c50d8ae3SPaolo Bonzini } 5848c50d8ae3SPaolo Bonzini 5849c50d8ae3SPaolo Bonzini static __always_inline bool 5850610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5851302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5852c50d8ae3SPaolo Bonzini { 58533bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5854302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5855c50d8ae3SPaolo Bonzini } 5856c50d8ae3SPaolo Bonzini 5857c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5858c50d8ae3SPaolo Bonzini { 58594a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 58604a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5861c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 586203ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5863cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5864c50d8ae3SPaolo Bonzini } 5865c50d8ae3SPaolo Bonzini 586604d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5867c50d8ae3SPaolo Bonzini { 5868c50d8ae3SPaolo Bonzini struct page *page; 5869c50d8ae3SPaolo Bonzini int i; 5870c50d8ae3SPaolo Bonzini 5871b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5872b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 587304d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 587404d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 587504d28e37SSean Christopherson 587627f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 587727f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 587827f4fca2SLai Jiangshan return 0; 587927f4fca2SLai Jiangshan 5880c50d8ae3SPaolo Bonzini /* 5881c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5882c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5883c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5884c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 588504d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 588604d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 588704d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 588804d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 588984432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5890c50d8ae3SPaolo Bonzini */ 5891d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5892c50d8ae3SPaolo Bonzini return 0; 5893c50d8ae3SPaolo Bonzini 5894c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5895c50d8ae3SPaolo Bonzini if (!page) 5896c50d8ae3SPaolo Bonzini return -ENOMEM; 5897c50d8ae3SPaolo Bonzini 5898c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 58994a98623dSSean Christopherson 59004a98623dSSean Christopherson /* 59014a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 59024a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 59034a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 59044a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 59054a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 59064a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 59074a98623dSSean Christopherson */ 59084a98623dSSean Christopherson if (!tdp_enabled) 59094a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 59104a98623dSSean Christopherson else 5911e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 59124a98623dSSean Christopherson 5913c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5914c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5915c50d8ae3SPaolo Bonzini 5916c50d8ae3SPaolo Bonzini return 0; 5917c50d8ae3SPaolo Bonzini } 5918c50d8ae3SPaolo Bonzini 5919c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5920c50d8ae3SPaolo Bonzini { 5921c50d8ae3SPaolo Bonzini int ret; 5922c50d8ae3SPaolo Bonzini 59235962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 59245f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 59255f6078f9SSean Christopherson 59265962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 59275f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 59285962bfb7SSean Christopherson 592996880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 593096880883SSean Christopherson 5931c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5932c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5933c50d8ae3SPaolo Bonzini 593404d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5935c50d8ae3SPaolo Bonzini if (ret) 5936c50d8ae3SPaolo Bonzini return ret; 5937c50d8ae3SPaolo Bonzini 593804d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5939c50d8ae3SPaolo Bonzini if (ret) 5940c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5941c50d8ae3SPaolo Bonzini 5942c50d8ae3SPaolo Bonzini return ret; 5943c50d8ae3SPaolo Bonzini fail_allocate_root: 5944c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5945c50d8ae3SPaolo Bonzini return ret; 5946c50d8ae3SPaolo Bonzini } 5947c50d8ae3SPaolo Bonzini 5948c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5949c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5950c50d8ae3SPaolo Bonzini { 5951c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5952c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5953b28cb0cdSSean Christopherson bool unstable; 5954c50d8ae3SPaolo Bonzini 5955c50d8ae3SPaolo Bonzini restart: 5956c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5957c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5958c50d8ae3SPaolo Bonzini /* 5959c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5960c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5961c50d8ae3SPaolo Bonzini */ 5962c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5963c50d8ae3SPaolo Bonzini break; 5964c50d8ae3SPaolo Bonzini 5965c50d8ae3SPaolo Bonzini /* 5966f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5967f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5968f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5969c50d8ae3SPaolo Bonzini */ 5970f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5971c50d8ae3SPaolo Bonzini continue; 5972c50d8ae3SPaolo Bonzini 5973c50d8ae3SPaolo Bonzini /* 5974c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5975c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5976c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5977c50d8ae3SPaolo Bonzini * be in active use by the guest. 5978c50d8ae3SPaolo Bonzini */ 5979c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5980531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5981c50d8ae3SPaolo Bonzini batch = 0; 5982c50d8ae3SPaolo Bonzini goto restart; 5983c50d8ae3SPaolo Bonzini } 5984c50d8ae3SPaolo Bonzini 5985b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 5986b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 5987c50d8ae3SPaolo Bonzini batch += nr_zapped; 5988b28cb0cdSSean Christopherson 5989b28cb0cdSSean Christopherson if (unstable) 5990c50d8ae3SPaolo Bonzini goto restart; 5991c50d8ae3SPaolo Bonzini } 5992c50d8ae3SPaolo Bonzini 5993c50d8ae3SPaolo Bonzini /* 59947ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 59957ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 59967ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 59977ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 59987ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 59997ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 60007ae5840eSSean Christopherson * running with an obsolete MMU. 6001c50d8ae3SPaolo Bonzini */ 6002c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 6003c50d8ae3SPaolo Bonzini } 6004c50d8ae3SPaolo Bonzini 6005c50d8ae3SPaolo Bonzini /* 6006c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 6007c50d8ae3SPaolo Bonzini * to zap obsolete pages. 6008c50d8ae3SPaolo Bonzini * 6009c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 6010c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 6011c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 6012c50d8ae3SPaolo Bonzini * after calling the function. 6013c50d8ae3SPaolo Bonzini */ 6014c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 6015c50d8ae3SPaolo Bonzini { 6016c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 6017c50d8ae3SPaolo Bonzini 6018531810caSBen Gardon write_lock(&kvm->mmu_lock); 6019c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 6020c50d8ae3SPaolo Bonzini 6021c50d8ae3SPaolo Bonzini /* 6022c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 6023c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 6024c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 6025c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 6026c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 6027c50d8ae3SPaolo Bonzini */ 6028c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 6029c50d8ae3SPaolo Bonzini 60302f6f66ccSSean Christopherson /* 60312f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 60322f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 60332f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 60342f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 6035b7cccd39SBen Gardon */ 60361f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6037b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 6038b7cccd39SBen Gardon 6039c50d8ae3SPaolo Bonzini /* 6040c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 6041c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 6042c50d8ae3SPaolo Bonzini * mmu_valid_gen. 6043c50d8ae3SPaolo Bonzini * 6044c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 6045c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 6046c50d8ae3SPaolo Bonzini */ 6047527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 6048c50d8ae3SPaolo Bonzini 6049c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 6050faaf05b0SBen Gardon 6051531810caSBen Gardon write_unlock(&kvm->mmu_lock); 60524c6654bdSBen Gardon 6053f28e9c7fSSean Christopherson /* 6054f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 6055f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 6056f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 6057f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 6058f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 6059f28e9c7fSSean Christopherson * lead to use-after-free. 6060f28e9c7fSSean Christopherson */ 60611f98f2bdSDavid Matlack if (tdp_mmu_enabled) 60624c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 6063c50d8ae3SPaolo Bonzini } 6064c50d8ae3SPaolo Bonzini 6065c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 6066c50d8ae3SPaolo Bonzini { 6067c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 6068c50d8ae3SPaolo Bonzini } 6069c50d8ae3SPaolo Bonzini 6070c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 6071c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 6072c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 6073c50d8ae3SPaolo Bonzini { 6074c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6075c50d8ae3SPaolo Bonzini } 6076c50d8ae3SPaolo Bonzini 6077a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 6078c50d8ae3SPaolo Bonzini { 6079c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6080a1a39128SPaolo Bonzini int r; 6081c50d8ae3SPaolo Bonzini 6082a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 6083a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 608455c510e2SSean Christopherson INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages); 6085ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 6086ce25681dSSean Christopherson 608709732d2bSDavid Matlack if (tdp_mmu_enabled) { 6088a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 6089a1a39128SPaolo Bonzini if (r < 0) 6090a1a39128SPaolo Bonzini return r; 609109732d2bSDavid Matlack } 6092fe5db27dSBen Gardon 6093c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 6094c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 6095c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 6096ada51a9dSDavid Matlack 6097ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 6098ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 6099ada51a9dSDavid Matlack 6100ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 6101ada51a9dSDavid Matlack 6102ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 6103ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 6104ada51a9dSDavid Matlack 6105a1a39128SPaolo Bonzini return 0; 6106c50d8ae3SPaolo Bonzini } 6107c50d8ae3SPaolo Bonzini 6108ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 6109ada51a9dSDavid Matlack { 6110ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 6111ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6112ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6113ada51a9dSDavid Matlack } 6114ada51a9dSDavid Matlack 6115c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6116c50d8ae3SPaolo Bonzini { 6117c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6118c50d8ae3SPaolo Bonzini 6119c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 6120fe5db27dSBen Gardon 612109732d2bSDavid Matlack if (tdp_mmu_enabled) 6122fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6123ada51a9dSDavid Matlack 6124ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6125c50d8ae3SPaolo Bonzini } 6126c50d8ae3SPaolo Bonzini 61272833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 612821fa3246SSean Christopherson { 612921fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 613021fa3246SSean Christopherson struct kvm_memslots *slots; 6131f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 613221fa3246SSean Christopherson bool flush = false; 613321fa3246SSean Christopherson gfn_t start, end; 6134f4209439SMaciej S. Szmigiero int i; 613521fa3246SSean Christopherson 613621fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 613721fa3246SSean Christopherson return flush; 613821fa3246SSean Christopherson 613921fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 614021fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6141f4209439SMaciej S. Szmigiero 6142f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6143f4209439SMaciej S. Szmigiero memslot = iter.slot; 614421fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 614521fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6146f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 614721fa3246SSean Christopherson continue; 614821fa3246SSean Christopherson 6149f8480721SSean Christopherson flush = slot_handle_level_range(kvm, memslot, __kvm_zap_rmap, 615021fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 615121fa3246SSean Christopherson start, end - 1, true, flush); 615221fa3246SSean Christopherson } 615321fa3246SSean Christopherson } 615421fa3246SSean Christopherson 615521fa3246SSean Christopherson return flush; 615621fa3246SSean Christopherson } 615721fa3246SSean Christopherson 615888f58535SMaxim Levitsky /* 615988f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 616088f58535SMaxim Levitsky * (not including it) 616188f58535SMaxim Levitsky */ 6162c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6163c50d8ae3SPaolo Bonzini { 616421fa3246SSean Christopherson bool flush; 6165c50d8ae3SPaolo Bonzini int i; 6166c50d8ae3SPaolo Bonzini 6167f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6168f4209439SMaciej S. Szmigiero return; 6169f4209439SMaciej S. Szmigiero 6170531810caSBen Gardon write_lock(&kvm->mmu_lock); 61715a324c24SSean Christopherson 61726d3085e4SSean Christopherson kvm_mmu_invalidate_begin(kvm, 0, -1ul); 6173edb298c6SMaxim Levitsky 61742833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 61756103bc07SBen Gardon 61761f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 61776103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 6178f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 6179f47e5bbbSSean Christopherson gfn_end, true, flush); 61806103bc07SBen Gardon } 61815a324c24SSean Christopherson 61825a324c24SSean Christopherson if (flush) 6183bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 6184bc3b3c10SSean Christopherson gfn_end - gfn_start); 61855a324c24SSean Christopherson 61866d3085e4SSean Christopherson kvm_mmu_invalidate_end(kvm, 0, -1ul); 6187edb298c6SMaxim Levitsky 61885a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6189c50d8ae3SPaolo Bonzini } 6190c50d8ae3SPaolo Bonzini 6191c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 61920a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6193269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6194c50d8ae3SPaolo Bonzini { 61951346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6196c50d8ae3SPaolo Bonzini } 6197c50d8ae3SPaolo Bonzini 6198c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6199269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 62003c9bd400SJay Zhou int start_level) 6201c50d8ae3SPaolo Bonzini { 6202e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6203531810caSBen Gardon write_lock(&kvm->mmu_lock); 6204b64d740eSJunaid Shahid slot_handle_level(kvm, memslot, slot_rmap_write_protect, 6205b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6206531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6207e2209710SBen Gardon } 6208c50d8ae3SPaolo Bonzini 62091f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 621024ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6211b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 621224ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 621324ae4cfaSBen Gardon } 6214c50d8ae3SPaolo Bonzini } 6215c50d8ae3SPaolo Bonzini 6216ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6217ada51a9dSDavid Matlack { 6218ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6219ada51a9dSDavid Matlack } 6220ada51a9dSDavid Matlack 6221ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6222ada51a9dSDavid Matlack { 6223ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6224ada51a9dSDavid Matlack return true; 6225ada51a9dSDavid Matlack 6226ada51a9dSDavid Matlack /* 6227ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6228ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6229ada51a9dSDavid Matlack * is possible but not worth the complexity. 6230ada51a9dSDavid Matlack */ 6231ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6232ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6233ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6234ada51a9dSDavid Matlack } 6235ada51a9dSDavid Matlack 6236ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6237ada51a9dSDavid Matlack { 6238b9b71f43SSean Christopherson /* 6239b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6240dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6241b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6242dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6243dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6244dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6245dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6246dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6247dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6248dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6249b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6250b9b71f43SSean Christopherson */ 6251b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6252b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6253ada51a9dSDavid Matlack int r; 6254ada51a9dSDavid Matlack 6255ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6256ada51a9dSDavid Matlack 6257b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6258ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6259ada51a9dSDavid Matlack if (r) 6260ada51a9dSDavid Matlack return r; 6261ada51a9dSDavid Matlack 6262ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6263ada51a9dSDavid Matlack if (r) 6264ada51a9dSDavid Matlack return r; 6265ada51a9dSDavid Matlack 6266ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6267ada51a9dSDavid Matlack } 6268ada51a9dSDavid Matlack 6269ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6270ada51a9dSDavid Matlack { 6271ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6272ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6273ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6274ada51a9dSDavid Matlack unsigned int access; 6275ada51a9dSDavid Matlack gfn_t gfn; 6276ada51a9dSDavid Matlack 627779e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 627879e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6279ada51a9dSDavid Matlack 6280ada51a9dSDavid Matlack /* 6281ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6282ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6283ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6284ada51a9dSDavid Matlack * mapped with smaller pages. 6285ada51a9dSDavid Matlack */ 6286ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6287ada51a9dSDavid Matlack 6288ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6289ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6290ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6291ada51a9dSDavid Matlack 6292ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6293ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6294ada51a9dSDavid Matlack } 6295ada51a9dSDavid Matlack 6296ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6297ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6298ada51a9dSDavid Matlack u64 *huge_sptep) 6299ada51a9dSDavid Matlack 6300ada51a9dSDavid Matlack { 6301ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6302ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6303ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 630403787394SPaolo Bonzini bool flush = false; 6305ada51a9dSDavid Matlack u64 *sptep, spte; 6306ada51a9dSDavid Matlack gfn_t gfn; 6307ada51a9dSDavid Matlack int index; 6308ada51a9dSDavid Matlack 6309ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6310ada51a9dSDavid Matlack 6311ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6312ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6313ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6314ada51a9dSDavid Matlack 6315ada51a9dSDavid Matlack /* 6316ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6317ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6318ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6319ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6320ada51a9dSDavid Matlack * modify them. 6321ada51a9dSDavid Matlack * 632203787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 632303787394SPaolo Bonzini * that lower level page table may only be partially populated. 632403787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 632503787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 632603787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 632703787394SPaolo Bonzini * fail to detect the need to flush. 6328ada51a9dSDavid Matlack */ 632903787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 633003787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6331ada51a9dSDavid Matlack continue; 633203787394SPaolo Bonzini } 6333ada51a9dSDavid Matlack 6334ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6335ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6336ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6337ada51a9dSDavid Matlack } 6338ada51a9dSDavid Matlack 633903787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6340ada51a9dSDavid Matlack } 6341ada51a9dSDavid Matlack 6342ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6343ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6344ada51a9dSDavid Matlack u64 *huge_sptep) 6345ada51a9dSDavid Matlack { 6346ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6347ada51a9dSDavid Matlack int level, r = 0; 6348ada51a9dSDavid Matlack gfn_t gfn; 6349ada51a9dSDavid Matlack u64 spte; 6350ada51a9dSDavid Matlack 6351ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 635279e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6353ada51a9dSDavid Matlack level = huge_sp->role.level; 6354ada51a9dSDavid Matlack spte = *huge_sptep; 6355ada51a9dSDavid Matlack 6356ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6357ada51a9dSDavid Matlack r = -ENOSPC; 6358ada51a9dSDavid Matlack goto out; 6359ada51a9dSDavid Matlack } 6360ada51a9dSDavid Matlack 6361ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6362ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6363ada51a9dSDavid Matlack cond_resched(); 6364ada51a9dSDavid Matlack /* 6365ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6366ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6367ada51a9dSDavid Matlack * dropped. 6368ada51a9dSDavid Matlack */ 6369ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6370ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6371ada51a9dSDavid Matlack goto out; 6372ada51a9dSDavid Matlack } 6373ada51a9dSDavid Matlack 6374ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6375ada51a9dSDavid Matlack 6376ada51a9dSDavid Matlack out: 6377ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6378ada51a9dSDavid Matlack return r; 6379ada51a9dSDavid Matlack } 6380ada51a9dSDavid Matlack 6381ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6382ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6383ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6384ada51a9dSDavid Matlack { 6385ada51a9dSDavid Matlack struct rmap_iterator iter; 6386ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6387ada51a9dSDavid Matlack u64 *huge_sptep; 6388ada51a9dSDavid Matlack int r; 6389ada51a9dSDavid Matlack 6390ada51a9dSDavid Matlack restart: 6391ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6392ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6393ada51a9dSDavid Matlack 6394ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6395ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6396ada51a9dSDavid Matlack continue; 6397ada51a9dSDavid Matlack 6398ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6399ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6400ada51a9dSDavid Matlack continue; 6401ada51a9dSDavid Matlack 6402ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6403ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6404ada51a9dSDavid Matlack continue; 6405ada51a9dSDavid Matlack 6406ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6407ada51a9dSDavid Matlack if (sp->role.invalid) 6408ada51a9dSDavid Matlack continue; 6409ada51a9dSDavid Matlack 6410ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6411ada51a9dSDavid Matlack 6412ada51a9dSDavid Matlack /* 6413ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6414ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6415ada51a9dSDavid Matlack * back into a consistent state. 6416ada51a9dSDavid Matlack */ 6417ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6418ada51a9dSDavid Matlack goto restart; 6419ada51a9dSDavid Matlack 6420ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6421ada51a9dSDavid Matlack break; 6422ada51a9dSDavid Matlack } 6423ada51a9dSDavid Matlack 6424ada51a9dSDavid Matlack return false; 6425ada51a9dSDavid Matlack } 6426ada51a9dSDavid Matlack 6427ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6428ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6429ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6430ada51a9dSDavid Matlack int target_level) 6431ada51a9dSDavid Matlack { 6432ada51a9dSDavid Matlack int level; 6433ada51a9dSDavid Matlack 6434ada51a9dSDavid Matlack /* 6435ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6436ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6437ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6438ada51a9dSDavid Matlack * already at the target level. 6439ada51a9dSDavid Matlack */ 6440ada51a9dSDavid Matlack for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) { 6441ada51a9dSDavid Matlack slot_handle_level_range(kvm, slot, shadow_mmu_try_split_huge_pages, 6442ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6443ada51a9dSDavid Matlack } 6444ada51a9dSDavid Matlack } 6445ada51a9dSDavid Matlack 6446cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6447cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6448cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6449cb00a70bSDavid Matlack u64 start, u64 end, 6450cb00a70bSDavid Matlack int target_level) 6451cb00a70bSDavid Matlack { 64521f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6453ada51a9dSDavid Matlack return; 6454ada51a9dSDavid Matlack 6455ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6456ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6457ada51a9dSDavid Matlack 6458ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6459cb00a70bSDavid Matlack 6460cb00a70bSDavid Matlack /* 6461cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6462cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6463cb00a70bSDavid Matlack */ 6464cb00a70bSDavid Matlack } 6465cb00a70bSDavid Matlack 6466a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6467a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6468a3fe5dbdSDavid Matlack int target_level) 6469a3fe5dbdSDavid Matlack { 6470a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6471a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6472a3fe5dbdSDavid Matlack 64731f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6474ada51a9dSDavid Matlack return; 6475ada51a9dSDavid Matlack 6476ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6477ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6478ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6479ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6480ada51a9dSDavid Matlack } 6481ada51a9dSDavid Matlack 6482a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6483cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6484a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6485a3fe5dbdSDavid Matlack 6486a3fe5dbdSDavid Matlack /* 6487a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6488a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6489a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6490a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6491a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6492a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6493a3fe5dbdSDavid Matlack * SPTEs. 6494a3fe5dbdSDavid Matlack */ 6495a3fe5dbdSDavid Matlack } 6496a3fe5dbdSDavid Matlack 6497c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 64980a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6499269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6500c50d8ae3SPaolo Bonzini { 6501c50d8ae3SPaolo Bonzini u64 *sptep; 6502c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6503c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6504c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6505c50d8ae3SPaolo Bonzini 6506c50d8ae3SPaolo Bonzini restart: 6507c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 650857354682SSean Christopherson sp = sptep_to_sp(sptep); 6509c50d8ae3SPaolo Bonzini 6510c50d8ae3SPaolo Bonzini /* 6511c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6512c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6513c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6514c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6515c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6516c50d8ae3SPaolo Bonzini */ 65175d49f08cSSean Christopherson if (sp->role.direct && 65189eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6519a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 65209202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6521c50d8ae3SPaolo Bonzini 6522c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6523c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6524c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6525c50d8ae3SPaolo Bonzini else 6526c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6527c50d8ae3SPaolo Bonzini 6528c50d8ae3SPaolo Bonzini goto restart; 6529c50d8ae3SPaolo Bonzini } 6530c50d8ae3SPaolo Bonzini } 6531c50d8ae3SPaolo Bonzini 6532c50d8ae3SPaolo Bonzini return need_tlb_flush; 6533c50d8ae3SPaolo Bonzini } 6534c50d8ae3SPaolo Bonzini 653520d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 653620d49186SDavid Matlack const struct kvm_memory_slot *slot) 653720d49186SDavid Matlack { 653820d49186SDavid Matlack /* 653920d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 654020d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 654120d49186SDavid Matlack */ 654220d49186SDavid Matlack if (slot_handle_level(kvm, slot, kvm_mmu_zap_collapsible_spte, 654320d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 654420d49186SDavid Matlack kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 654520d49186SDavid Matlack } 654620d49186SDavid Matlack 6547c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6548269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6549c50d8ae3SPaolo Bonzini { 6550e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6551531810caSBen Gardon write_lock(&kvm->mmu_lock); 655220d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6553531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6554e2209710SBen Gardon } 65552db6f772SBen Gardon 65561f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 65572db6f772SBen Gardon read_lock(&kvm->mmu_lock); 65584b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 65592db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 65602db6f772SBen Gardon } 6561c50d8ae3SPaolo Bonzini } 6562c50d8ae3SPaolo Bonzini 6563b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 65646c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6565b3594ffbSSean Christopherson { 6566b3594ffbSSean Christopherson /* 65677f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6568302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 65697f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 65707f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 65717f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6572b3594ffbSSean Christopherson */ 6573b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6574cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6575cec37648SSean Christopherson memslot->npages); 6576b3594ffbSSean Christopherson } 6577b3594ffbSSean Christopherson 6578c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6579269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6580c50d8ae3SPaolo Bonzini { 6581e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6582531810caSBen Gardon write_lock(&kvm->mmu_lock); 6583610265eaSDavid Matlack /* 6584610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6585610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6586610265eaSDavid Matlack */ 6587b64d740eSJunaid Shahid slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6588531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6589e2209710SBen Gardon } 6590c50d8ae3SPaolo Bonzini 65911f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 659224ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6593b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 659424ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 659524ae4cfaSBen Gardon } 659624ae4cfaSBen Gardon 6597c50d8ae3SPaolo Bonzini /* 6598b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6599b64d740eSJunaid Shahid * 6600c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6601c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6602c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6603c50d8ae3SPaolo Bonzini * dirty_bitmap. 6604c50d8ae3SPaolo Bonzini */ 6605c50d8ae3SPaolo Bonzini } 6606c50d8ae3SPaolo Bonzini 6607c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6608c50d8ae3SPaolo Bonzini { 6609c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6610c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6611c50d8ae3SPaolo Bonzini int ign; 6612c50d8ae3SPaolo Bonzini 6613531810caSBen Gardon write_lock(&kvm->mmu_lock); 6614c50d8ae3SPaolo Bonzini restart: 6615c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6616f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6617c50d8ae3SPaolo Bonzini continue; 6618c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6619c50d8ae3SPaolo Bonzini goto restart; 6620531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6621c50d8ae3SPaolo Bonzini goto restart; 6622c50d8ae3SPaolo Bonzini } 6623c50d8ae3SPaolo Bonzini 6624c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6625faaf05b0SBen Gardon 66261f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6627faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6628faaf05b0SBen Gardon 6629531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6630c50d8ae3SPaolo Bonzini } 6631c50d8ae3SPaolo Bonzini 6632c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6633c50d8ae3SPaolo Bonzini { 6634c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6635c50d8ae3SPaolo Bonzini 6636c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6637c50d8ae3SPaolo Bonzini 6638c50d8ae3SPaolo Bonzini /* 6639c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6640c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6641c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6642c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6643c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6644c50d8ae3SPaolo Bonzini */ 6645c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6646c50d8ae3SPaolo Bonzini 6647c50d8ae3SPaolo Bonzini /* 6648c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6649c50d8ae3SPaolo Bonzini * zap all shadow pages. 6650c50d8ae3SPaolo Bonzini */ 6651c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 66528d20bd63SSean Christopherson kvm_debug_ratelimited("zapping shadow pages for mmio generation wraparound\n"); 6653c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6654c50d8ae3SPaolo Bonzini } 6655c50d8ae3SPaolo Bonzini } 6656c50d8ae3SPaolo Bonzini 6657c50d8ae3SPaolo Bonzini static unsigned long 6658c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6659c50d8ae3SPaolo Bonzini { 6660c50d8ae3SPaolo Bonzini struct kvm *kvm; 6661c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6662c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6663c50d8ae3SPaolo Bonzini 6664c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6665c50d8ae3SPaolo Bonzini 6666c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6667c50d8ae3SPaolo Bonzini int idx; 6668c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6669c50d8ae3SPaolo Bonzini 6670c50d8ae3SPaolo Bonzini /* 6671c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6672c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6673c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6674c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6675c50d8ae3SPaolo Bonzini */ 6676c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6677c50d8ae3SPaolo Bonzini break; 6678c50d8ae3SPaolo Bonzini /* 6679c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6680c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6681c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6682c50d8ae3SPaolo Bonzini * anyway. 6683c50d8ae3SPaolo Bonzini */ 6684c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6685c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6686c50d8ae3SPaolo Bonzini continue; 6687c50d8ae3SPaolo Bonzini 6688c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6689531810caSBen Gardon write_lock(&kvm->mmu_lock); 6690c50d8ae3SPaolo Bonzini 6691c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6692c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6693c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6694c50d8ae3SPaolo Bonzini goto unlock; 6695c50d8ae3SPaolo Bonzini } 6696c50d8ae3SPaolo Bonzini 6697ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6698c50d8ae3SPaolo Bonzini 6699c50d8ae3SPaolo Bonzini unlock: 6700531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6701c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6702c50d8ae3SPaolo Bonzini 6703c50d8ae3SPaolo Bonzini /* 6704c50d8ae3SPaolo Bonzini * unfair on small ones 6705c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6706c50d8ae3SPaolo Bonzini * sadness comes quickly 6707c50d8ae3SPaolo Bonzini */ 6708c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6709c50d8ae3SPaolo Bonzini break; 6710c50d8ae3SPaolo Bonzini } 6711c50d8ae3SPaolo Bonzini 6712c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6713c50d8ae3SPaolo Bonzini return freed; 6714c50d8ae3SPaolo Bonzini } 6715c50d8ae3SPaolo Bonzini 6716c50d8ae3SPaolo Bonzini static unsigned long 6717c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6718c50d8ae3SPaolo Bonzini { 6719c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6720c50d8ae3SPaolo Bonzini } 6721c50d8ae3SPaolo Bonzini 6722c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6723c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6724c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6725c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6726c50d8ae3SPaolo Bonzini }; 6727c50d8ae3SPaolo Bonzini 6728c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6729c50d8ae3SPaolo Bonzini { 6730c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6731c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6732c50d8ae3SPaolo Bonzini } 6733c50d8ae3SPaolo Bonzini 6734c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6735c50d8ae3SPaolo Bonzini { 6736c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6737c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6738c50d8ae3SPaolo Bonzini } 6739c50d8ae3SPaolo Bonzini 6740c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6741c50d8ae3SPaolo Bonzini { 6742c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6743c50d8ae3SPaolo Bonzini } 6744c50d8ae3SPaolo Bonzini 6745c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6746c50d8ae3SPaolo Bonzini { 6747c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6748c50d8ae3SPaolo Bonzini bool new_val; 6749c50d8ae3SPaolo Bonzini 6750c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6751c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6752c50d8ae3SPaolo Bonzini new_val = 0; 6753c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6754c50d8ae3SPaolo Bonzini new_val = 1; 6755c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6756c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6757c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6758c50d8ae3SPaolo Bonzini return -EINVAL; 6759c50d8ae3SPaolo Bonzini 6760c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6761c50d8ae3SPaolo Bonzini 6762c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6763c50d8ae3SPaolo Bonzini struct kvm *kvm; 6764c50d8ae3SPaolo Bonzini 6765c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6766c50d8ae3SPaolo Bonzini 6767c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6768c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6769c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6770c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6771c50d8ae3SPaolo Bonzini 677255c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 6773c50d8ae3SPaolo Bonzini } 6774c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6775c50d8ae3SPaolo Bonzini } 6776c50d8ae3SPaolo Bonzini 6777c50d8ae3SPaolo Bonzini return 0; 6778c50d8ae3SPaolo Bonzini } 6779c50d8ae3SPaolo Bonzini 67801d0e8480SSean Christopherson /* 67811d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 67821d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 6783c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 6784c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 67851d0e8480SSean Christopherson */ 6786982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 6787c50d8ae3SPaolo Bonzini { 6788c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6789c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 6790c3e0c8c2SSean Christopherson 67911f98f2bdSDavid Matlack /* 67921f98f2bdSDavid Matlack * Snapshot userspace's desire to enable the TDP MMU. Whether or not the 67931f98f2bdSDavid Matlack * TDP MMU is actually enabled is determined in kvm_configure_mmu() 67941f98f2bdSDavid Matlack * when the vendor module is loaded. 67951f98f2bdSDavid Matlack */ 67961f98f2bdSDavid Matlack tdp_mmu_allowed = tdp_mmu_enabled; 67971f98f2bdSDavid Matlack 6798c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 67991d0e8480SSean Christopherson } 68001d0e8480SSean Christopherson 68011d0e8480SSean Christopherson /* 68021d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 68031d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 68041d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 68051d0e8480SSean Christopherson */ 68061d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 68071d0e8480SSean Christopherson { 68081d0e8480SSean Christopherson int ret = -ENOMEM; 6809c50d8ae3SPaolo Bonzini 6810c50d8ae3SPaolo Bonzini /* 6811c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6812c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6813c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6814c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6815c50d8ae3SPaolo Bonzini */ 6816c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6817c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 68187a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6819c50d8ae3SPaolo Bonzini 6820c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6821c50d8ae3SPaolo Bonzini 6822c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6823c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6824c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6825c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6826c50d8ae3SPaolo Bonzini goto out; 6827c50d8ae3SPaolo Bonzini 6828c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6829c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6830c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6831c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6832c50d8ae3SPaolo Bonzini goto out; 6833c50d8ae3SPaolo Bonzini 6834c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6835c50d8ae3SPaolo Bonzini goto out; 6836c50d8ae3SPaolo Bonzini 6837e33c267aSRoman Gushchin ret = register_shrinker(&mmu_shrinker, "x86-mmu"); 6838c50d8ae3SPaolo Bonzini if (ret) 6839d7c9bfb9SMiaohe Lin goto out_shrinker; 6840c50d8ae3SPaolo Bonzini 6841c50d8ae3SPaolo Bonzini return 0; 6842c50d8ae3SPaolo Bonzini 6843d7c9bfb9SMiaohe Lin out_shrinker: 6844d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 6845c50d8ae3SPaolo Bonzini out: 6846c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6847c50d8ae3SPaolo Bonzini return ret; 6848c50d8ae3SPaolo Bonzini } 6849c50d8ae3SPaolo Bonzini 6850c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6851c50d8ae3SPaolo Bonzini { 6852c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6853c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6854c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6855c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6856c50d8ae3SPaolo Bonzini } 6857c50d8ae3SPaolo Bonzini 68581d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6859c50d8ae3SPaolo Bonzini { 6860c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6861c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6862c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6863c50d8ae3SPaolo Bonzini } 6864c50d8ae3SPaolo Bonzini 6865f47491d7SSean Christopherson /* 6866f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6867f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6868f47491d7SSean Christopherson */ 6869f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6870f47491d7SSean Christopherson { 6871f47491d7SSean Christopherson /* 6872f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6873f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6874f47491d7SSean Christopherson */ 6875f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6876f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6877f47491d7SSean Christopherson 6878f47491d7SSean Christopherson if (!enabled || !ratio) 6879f47491d7SSean Christopherson return false; 6880f47491d7SSean Christopherson 6881f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6882f47491d7SSean Christopherson if (!*period) { 6883f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6884f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6885f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6886f47491d7SSean Christopherson } 6887f47491d7SSean Christopherson return true; 6888f47491d7SSean Christopherson } 6889f47491d7SSean Christopherson 68904dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6891c50d8ae3SPaolo Bonzini { 68924dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 68934dfe4f40SJunaid Shahid uint old_period, new_period; 6894c50d8ae3SPaolo Bonzini int err; 6895c50d8ae3SPaolo Bonzini 6896f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 68974dfe4f40SJunaid Shahid 6898c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6899c50d8ae3SPaolo Bonzini if (err) 6900c50d8ae3SPaolo Bonzini return err; 6901c50d8ae3SPaolo Bonzini 6902f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 69034dfe4f40SJunaid Shahid 6904f47491d7SSean Christopherson if (is_recovery_enabled && 69054dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6906c50d8ae3SPaolo Bonzini struct kvm *kvm; 6907c50d8ae3SPaolo Bonzini 6908c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6909c50d8ae3SPaolo Bonzini 6910c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 691155c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 6912c50d8ae3SPaolo Bonzini 6913c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6914c50d8ae3SPaolo Bonzini } 6915c50d8ae3SPaolo Bonzini 6916c50d8ae3SPaolo Bonzini return err; 6917c50d8ae3SPaolo Bonzini } 6918c50d8ae3SPaolo Bonzini 691955c510e2SSean Christopherson static void kvm_recover_nx_huge_pages(struct kvm *kvm) 6920c50d8ae3SPaolo Bonzini { 6921ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6922eb298605SDavid Matlack struct kvm_memory_slot *slot; 6923c50d8ae3SPaolo Bonzini int rcu_idx; 6924c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6925c50d8ae3SPaolo Bonzini unsigned int ratio; 6926c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6927048f4980SSean Christopherson bool flush = false; 6928c50d8ae3SPaolo Bonzini ulong to_zap; 6929c50d8ae3SPaolo Bonzini 6930c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6931531810caSBen Gardon write_lock(&kvm->mmu_lock); 6932c50d8ae3SPaolo Bonzini 6933bb95dfb9SSean Christopherson /* 6934bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6935bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6936bb95dfb9SSean Christopherson * callback. 6937bb95dfb9SSean Christopherson */ 6938bb95dfb9SSean Christopherson rcu_read_lock(); 6939bb95dfb9SSean Christopherson 6940c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6941ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 69427d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 694355c510e2SSean Christopherson if (list_empty(&kvm->arch.possible_nx_huge_pages)) 69447d919c7aSSean Christopherson break; 69457d919c7aSSean Christopherson 6946c50d8ae3SPaolo Bonzini /* 6947c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 694855c510e2SSean Christopherson * because the number of shadow pages that be replaced with an 694955c510e2SSean Christopherson * NX huge page is expected to be relatively small compared to 695055c510e2SSean Christopherson * the total number of shadow pages. And because the TDP MMU 695155c510e2SSean Christopherson * doesn't use active_mmu_pages. 6952c50d8ae3SPaolo Bonzini */ 695355c510e2SSean Christopherson sp = list_first_entry(&kvm->arch.possible_nx_huge_pages, 6954c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 695555c510e2SSean Christopherson possible_nx_huge_page_link); 695655c510e2SSean Christopherson WARN_ON_ONCE(!sp->nx_huge_page_disallowed); 6957eb298605SDavid Matlack WARN_ON_ONCE(!sp->role.direct); 6958eb298605SDavid Matlack 6959eb298605SDavid Matlack /* 6960eb298605SDavid Matlack * Unaccount and do not attempt to recover any NX Huge Pages 6961eb298605SDavid Matlack * that are being dirty tracked, as they would just be faulted 6962eb298605SDavid Matlack * back in as 4KiB pages. The NX Huge Pages in this slot will be 6963eb298605SDavid Matlack * recovered, along with all the other huge pages in the slot, 6964eb298605SDavid Matlack * when dirty logging is disabled. 69656c7b2202SPaolo Bonzini * 69666c7b2202SPaolo Bonzini * Since gfn_to_memslot() is relatively expensive, it helps to 69676c7b2202SPaolo Bonzini * skip it if it the test cannot possibly return true. On the 69686c7b2202SPaolo Bonzini * other hand, if any memslot has logging enabled, chances are 69696c7b2202SPaolo Bonzini * good that all of them do, in which case unaccount_nx_huge_page() 69706c7b2202SPaolo Bonzini * is much cheaper than zapping the page. 69716c7b2202SPaolo Bonzini * 69726c7b2202SPaolo Bonzini * If a memslot update is in progress, reading an incorrect value 69736c7b2202SPaolo Bonzini * of kvm->nr_memslots_dirty_logging is not a problem: if it is 69746c7b2202SPaolo Bonzini * becoming zero, gfn_to_memslot() will be done unnecessarily; if 69756c7b2202SPaolo Bonzini * it is becoming nonzero, the page will be zapped unnecessarily. 69766c7b2202SPaolo Bonzini * Either way, this only affects efficiency in racy situations, 69776c7b2202SPaolo Bonzini * and not correctness. 6978eb298605SDavid Matlack */ 69796c7b2202SPaolo Bonzini slot = NULL; 69806c7b2202SPaolo Bonzini if (atomic_read(&kvm->nr_memslots_dirty_logging)) { 69816c7b2202SPaolo Bonzini slot = gfn_to_memslot(kvm, sp->gfn); 69826c7b2202SPaolo Bonzini WARN_ON_ONCE(!slot); 698329cf0f50SBen Gardon } 6984c50d8ae3SPaolo Bonzini 6985eb298605SDavid Matlack if (slot && kvm_slot_dirty_track_enabled(slot)) 6986eb298605SDavid Matlack unaccount_nx_huge_page(kvm, sp); 6987eb298605SDavid Matlack else if (is_tdp_mmu_page(sp)) 6988c50d8ae3SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 69893a056757SSean Christopherson else 6990c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 699155c510e2SSean Christopherson WARN_ON_ONCE(sp->nx_huge_page_disallowed); 6992c50d8ae3SPaolo Bonzini 6993531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6994048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6995bb95dfb9SSean Christopherson rcu_read_unlock(); 6996bb95dfb9SSean Christopherson 6997531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6998048f4980SSean Christopherson flush = false; 6999bb95dfb9SSean Christopherson 7000bb95dfb9SSean Christopherson rcu_read_lock(); 7001c50d8ae3SPaolo Bonzini } 7002c50d8ae3SPaolo Bonzini } 7003048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7004c50d8ae3SPaolo Bonzini 7005bb95dfb9SSean Christopherson rcu_read_unlock(); 7006bb95dfb9SSean Christopherson 7007531810caSBen Gardon write_unlock(&kvm->mmu_lock); 7008c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 7009c50d8ae3SPaolo Bonzini } 7010c50d8ae3SPaolo Bonzini 701155c510e2SSean Christopherson static long get_nx_huge_page_recovery_timeout(u64 start_time) 7012c50d8ae3SPaolo Bonzini { 7013f47491d7SSean Christopherson bool enabled; 7014f47491d7SSean Christopherson uint period; 70154dfe4f40SJunaid Shahid 7016f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 70174dfe4f40SJunaid Shahid 7018f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 7019c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 7020c50d8ae3SPaolo Bonzini } 7021c50d8ae3SPaolo Bonzini 702255c510e2SSean Christopherson static int kvm_nx_huge_page_recovery_worker(struct kvm *kvm, uintptr_t data) 7023c50d8ae3SPaolo Bonzini { 7024c50d8ae3SPaolo Bonzini u64 start_time; 7025c50d8ae3SPaolo Bonzini long remaining_time; 7026c50d8ae3SPaolo Bonzini 7027c50d8ae3SPaolo Bonzini while (true) { 7028c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 702955c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7030c50d8ae3SPaolo Bonzini 7031c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7032c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 7033c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 703455c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7035c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7036c50d8ae3SPaolo Bonzini } 7037c50d8ae3SPaolo Bonzini 7038c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 7039c50d8ae3SPaolo Bonzini 7040c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 7041c50d8ae3SPaolo Bonzini return 0; 7042c50d8ae3SPaolo Bonzini 704355c510e2SSean Christopherson kvm_recover_nx_huge_pages(kvm); 7044c50d8ae3SPaolo Bonzini } 7045c50d8ae3SPaolo Bonzini } 7046c50d8ae3SPaolo Bonzini 7047c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 7048c50d8ae3SPaolo Bonzini { 7049c50d8ae3SPaolo Bonzini int err; 7050c50d8ae3SPaolo Bonzini 705155c510e2SSean Christopherson err = kvm_vm_create_worker_thread(kvm, kvm_nx_huge_page_recovery_worker, 0, 7052c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 705355c510e2SSean Christopherson &kvm->arch.nx_huge_page_recovery_thread); 7054c50d8ae3SPaolo Bonzini if (!err) 705555c510e2SSean Christopherson kthread_unpark(kvm->arch.nx_huge_page_recovery_thread); 7056c50d8ae3SPaolo Bonzini 7057c50d8ae3SPaolo Bonzini return err; 7058c50d8ae3SPaolo Bonzini } 7059c50d8ae3SPaolo Bonzini 7060c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 7061c50d8ae3SPaolo Bonzini { 706255c510e2SSean Christopherson if (kvm->arch.nx_huge_page_recovery_thread) 706355c510e2SSean Christopherson kthread_stop(kvm->arch.nx_huge_page_recovery_thread); 7064c50d8ae3SPaolo Bonzini } 7065