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 */ 17c50d8ae3SPaolo Bonzini 18c50d8ae3SPaolo Bonzini #include "irq.h" 1988197e6aS彭浩(Richard) #include "ioapic.h" 20c50d8ae3SPaolo Bonzini #include "mmu.h" 216ca9a6f3SSean Christopherson #include "mmu_internal.h" 22fe5db27dSBen Gardon #include "tdp_mmu.h" 23c50d8ae3SPaolo Bonzini #include "x86.h" 24c50d8ae3SPaolo Bonzini #include "kvm_cache_regs.h" 252f728d66SSean Christopherson #include "kvm_emulate.h" 26c50d8ae3SPaolo Bonzini #include "cpuid.h" 275a9624afSPaolo Bonzini #include "spte.h" 28c50d8ae3SPaolo Bonzini 29c50d8ae3SPaolo Bonzini #include <linux/kvm_host.h> 30c50d8ae3SPaolo Bonzini #include <linux/types.h> 31c50d8ae3SPaolo Bonzini #include <linux/string.h> 32c50d8ae3SPaolo Bonzini #include <linux/mm.h> 33c50d8ae3SPaolo Bonzini #include <linux/highmem.h> 34c50d8ae3SPaolo Bonzini #include <linux/moduleparam.h> 35c50d8ae3SPaolo Bonzini #include <linux/export.h> 36c50d8ae3SPaolo Bonzini #include <linux/swap.h> 37c50d8ae3SPaolo Bonzini #include <linux/hugetlb.h> 38c50d8ae3SPaolo Bonzini #include <linux/compiler.h> 39c50d8ae3SPaolo Bonzini #include <linux/srcu.h> 40c50d8ae3SPaolo Bonzini #include <linux/slab.h> 41c50d8ae3SPaolo Bonzini #include <linux/sched/signal.h> 42c50d8ae3SPaolo Bonzini #include <linux/uaccess.h> 43c50d8ae3SPaolo Bonzini #include <linux/hash.h> 44c50d8ae3SPaolo Bonzini #include <linux/kern_levels.h> 45c50d8ae3SPaolo Bonzini #include <linux/kthread.h> 46c50d8ae3SPaolo Bonzini 47c50d8ae3SPaolo Bonzini #include <asm/page.h> 48eb243d1dSIngo Molnar #include <asm/memtype.h> 49c50d8ae3SPaolo Bonzini #include <asm/cmpxchg.h> 50c50d8ae3SPaolo Bonzini #include <asm/io.h> 514a98623dSSean Christopherson #include <asm/set_memory.h> 52c50d8ae3SPaolo Bonzini #include <asm/vmx.h> 53c50d8ae3SPaolo Bonzini #include <asm/kvm_page_track.h> 54c50d8ae3SPaolo Bonzini #include "trace.h" 55c50d8ae3SPaolo Bonzini 56c50d8ae3SPaolo Bonzini extern bool itlb_multihit_kvm_mitigation; 57c50d8ae3SPaolo Bonzini 58a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 594dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 60c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 61c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 62c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 63c50d8ae3SPaolo Bonzini #else 64c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 65c50d8ae3SPaolo Bonzini #endif 66c50d8ae3SPaolo Bonzini 67c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 684dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 69c50d8ae3SPaolo Bonzini 70d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 71c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 72c50d8ae3SPaolo Bonzini .get = param_get_bool, 73c50d8ae3SPaolo Bonzini }; 74c50d8ae3SPaolo Bonzini 754dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 764dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 77c50d8ae3SPaolo Bonzini .get = param_get_uint, 78c50d8ae3SPaolo Bonzini }; 79c50d8ae3SPaolo Bonzini 80c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 81c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 824dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 83c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 84c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 854dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 864dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 874dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 88c50d8ae3SPaolo Bonzini 8971fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9071fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9171fe7013SSean Christopherson 92c50d8ae3SPaolo Bonzini /* 93c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 94c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 95c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 96c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 97c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 98c50d8ae3SPaolo Bonzini */ 99c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 100c50d8ae3SPaolo Bonzini 1011d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 102746700d2SWei Huang static int tdp_root_level __read_mostly; 10383013059SSean Christopherson static int max_tdp_level __read_mostly; 104703c335dSSean Christopherson 105c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1065a9624afSPaolo Bonzini bool dbg = 0; 107c50d8ae3SPaolo Bonzini module_param(dbg, bool, 0644); 108c50d8ae3SPaolo Bonzini #endif 109c50d8ae3SPaolo Bonzini 110c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 111c50d8ae3SPaolo Bonzini 112c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 113c50d8ae3SPaolo Bonzini 114dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 11513236e25SPeter Xu #define PTE_LIST_EXT 14 116c50d8ae3SPaolo Bonzini 11713236e25SPeter Xu /* 11813236e25SPeter Xu * Slight optimization of cacheline layout, by putting `more' and `spte_count' 11913236e25SPeter Xu * at the start; then accessing it will only use one single cacheline for 12013236e25SPeter Xu * either full (entries==PTE_LIST_EXT) case or entries<=6. 12113236e25SPeter Xu */ 122c50d8ae3SPaolo Bonzini struct pte_list_desc { 123c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 12413236e25SPeter Xu /* 12513236e25SPeter Xu * Stores number of entries stored in the pte_list_desc. No need to be 12613236e25SPeter Xu * u64 but just for easier alignment. When PTE_LIST_EXT, means full. 12713236e25SPeter Xu */ 12813236e25SPeter Xu u64 spte_count; 12913236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 130c50d8ae3SPaolo Bonzini }; 131c50d8ae3SPaolo Bonzini 132c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 133c50d8ae3SPaolo Bonzini u64 addr; 134c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 135c50d8ae3SPaolo Bonzini u64 *sptep; 136c50d8ae3SPaolo Bonzini int level; 137c50d8ae3SPaolo Bonzini unsigned index; 138c50d8ae3SPaolo Bonzini }; 139c50d8ae3SPaolo Bonzini 140c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 141c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 142c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 143c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 144c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 145c50d8ae3SPaolo Bonzini 146c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 147c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 148c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 149c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 150c50d8ae3SPaolo Bonzini 151c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 152c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 153c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 154c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 155c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 156c50d8ae3SPaolo Bonzini 157c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 15802c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 159c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 160c50d8ae3SPaolo Bonzini 161c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 162c50d8ae3SPaolo Bonzini 163594e91a1SSean Christopherson struct kvm_mmu_role_regs { 164594e91a1SSean Christopherson const unsigned long cr0; 165594e91a1SSean Christopherson const unsigned long cr4; 166594e91a1SSean Christopherson const u64 efer; 167594e91a1SSean Christopherson }; 168594e91a1SSean Christopherson 169c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 170c50d8ae3SPaolo Bonzini #include "mmutrace.h" 171c50d8ae3SPaolo Bonzini 172594e91a1SSean Christopherson /* 173594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1747a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 175594e91a1SSean Christopherson * the single source of truth for the MMU's state. 176594e91a1SSean Christopherson */ 177594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 17882ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 17982ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 180594e91a1SSean Christopherson { \ 181594e91a1SSean Christopherson return !!(regs->reg & flag); \ 182594e91a1SSean Christopherson } 183594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 184594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 185594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 186594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 187594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 188594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 189594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 190594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 191594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 192594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 193594e91a1SSean Christopherson 19460667724SSean Christopherson /* 19560667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 19660667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 19760667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 19860667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 19960667724SSean Christopherson */ 20060667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2014ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 20260667724SSean Christopherson { \ 203e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 20460667724SSean Christopherson } 20560667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 20660667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 20760667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 20860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 20960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 21060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 21160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 21256b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 21360667724SSean Christopherson 214faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 215faf72962SPaolo Bonzini { 216faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 217faf72962SPaolo Bonzini } 218faf72962SPaolo Bonzini 219faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 220faf72962SPaolo Bonzini { 221faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 222faf72962SPaolo Bonzini } 223faf72962SPaolo Bonzini 224594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 225594e91a1SSean Christopherson { 226594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 227594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 228594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 229594e91a1SSean Christopherson .efer = vcpu->arch.efer, 230594e91a1SSean Christopherson }; 231594e91a1SSean Christopherson 232594e91a1SSean Christopherson return regs; 233594e91a1SSean Christopherson } 234c50d8ae3SPaolo Bonzini 235c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 236c50d8ae3SPaolo Bonzini { 237afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 238c50d8ae3SPaolo Bonzini } 239c50d8ae3SPaolo Bonzini 240c50d8ae3SPaolo Bonzini static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm, 241c50d8ae3SPaolo Bonzini struct kvm_tlb_range *range) 242c50d8ae3SPaolo Bonzini { 243c50d8ae3SPaolo Bonzini int ret = -ENOTSUPP; 244c50d8ae3SPaolo Bonzini 245afaf0b2fSSean Christopherson if (range && kvm_x86_ops.tlb_remote_flush_with_range) 246b3646477SJason Baron ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range); 247c50d8ae3SPaolo Bonzini 248c50d8ae3SPaolo Bonzini if (ret) 249c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 250c50d8ae3SPaolo Bonzini } 251c50d8ae3SPaolo Bonzini 2522f2fad08SBen Gardon void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 253c50d8ae3SPaolo Bonzini u64 start_gfn, u64 pages) 254c50d8ae3SPaolo Bonzini { 255c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 256c50d8ae3SPaolo Bonzini 257c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 258c50d8ae3SPaolo Bonzini range.pages = pages; 259c50d8ae3SPaolo Bonzini 260c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_range(kvm, &range); 261c50d8ae3SPaolo Bonzini } 262c50d8ae3SPaolo Bonzini 2638f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2648f79b064SBen Gardon unsigned int access) 2658f79b064SBen Gardon { 266c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2678f79b064SBen Gardon 268c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 269c236d962SSean Christopherson mmu_spte_set(sptep, spte); 270c50d8ae3SPaolo Bonzini } 271c50d8ae3SPaolo Bonzini 272c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 273c50d8ae3SPaolo Bonzini { 274c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 275c50d8ae3SPaolo Bonzini 2768a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 277c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 278c50d8ae3SPaolo Bonzini 279c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 280c50d8ae3SPaolo Bonzini } 281c50d8ae3SPaolo Bonzini 282c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 283c50d8ae3SPaolo Bonzini { 284c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 285c50d8ae3SPaolo Bonzini } 286c50d8ae3SPaolo Bonzini 287c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 288c50d8ae3SPaolo Bonzini { 289c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 290c50d8ae3SPaolo Bonzini 291c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 292c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 293c50d8ae3SPaolo Bonzini return false; 294c50d8ae3SPaolo Bonzini 295c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 296c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 297c50d8ae3SPaolo Bonzini 298c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 299c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 300c50d8ae3SPaolo Bonzini } 301c50d8ae3SPaolo Bonzini 302c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 303c50d8ae3SPaolo Bonzini { 304c50d8ae3SPaolo Bonzini return 1; 305c50d8ae3SPaolo Bonzini } 306c50d8ae3SPaolo Bonzini 307c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 308c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 309c50d8ae3SPaolo Bonzini { 310c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 311c50d8ae3SPaolo Bonzini } 312c50d8ae3SPaolo Bonzini 313c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 314c50d8ae3SPaolo Bonzini { 315c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 316c50d8ae3SPaolo Bonzini } 317c50d8ae3SPaolo Bonzini 318c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 319c50d8ae3SPaolo Bonzini { 320c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 321c50d8ae3SPaolo Bonzini } 322c50d8ae3SPaolo Bonzini 323c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 324c50d8ae3SPaolo Bonzini { 325c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 326c50d8ae3SPaolo Bonzini } 327c50d8ae3SPaolo Bonzini #else 328c50d8ae3SPaolo Bonzini union split_spte { 329c50d8ae3SPaolo Bonzini struct { 330c50d8ae3SPaolo Bonzini u32 spte_low; 331c50d8ae3SPaolo Bonzini u32 spte_high; 332c50d8ae3SPaolo Bonzini }; 333c50d8ae3SPaolo Bonzini u64 spte; 334c50d8ae3SPaolo Bonzini }; 335c50d8ae3SPaolo Bonzini 336c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 337c50d8ae3SPaolo Bonzini { 33857354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 339c50d8ae3SPaolo Bonzini 340c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 341c50d8ae3SPaolo Bonzini return; 342c50d8ae3SPaolo Bonzini 343c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 344c50d8ae3SPaolo Bonzini smp_wmb(); 345c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 346c50d8ae3SPaolo Bonzini } 347c50d8ae3SPaolo Bonzini 348c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 349c50d8ae3SPaolo Bonzini { 350c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 351c50d8ae3SPaolo Bonzini 352c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 353c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 354c50d8ae3SPaolo Bonzini 355c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 356c50d8ae3SPaolo Bonzini 357c50d8ae3SPaolo Bonzini /* 358c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 359c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 360c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 361c50d8ae3SPaolo Bonzini */ 362c50d8ae3SPaolo Bonzini smp_wmb(); 363c50d8ae3SPaolo Bonzini 364c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 365c50d8ae3SPaolo Bonzini } 366c50d8ae3SPaolo Bonzini 367c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 368c50d8ae3SPaolo Bonzini { 369c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 370c50d8ae3SPaolo Bonzini 371c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 372c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 373c50d8ae3SPaolo Bonzini 374c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 375c50d8ae3SPaolo Bonzini 376c50d8ae3SPaolo Bonzini /* 377c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 378c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 379c50d8ae3SPaolo Bonzini */ 380c50d8ae3SPaolo Bonzini smp_wmb(); 381c50d8ae3SPaolo Bonzini 382c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 383c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 384c50d8ae3SPaolo Bonzini } 385c50d8ae3SPaolo Bonzini 386c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 387c50d8ae3SPaolo Bonzini { 388c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 389c50d8ae3SPaolo Bonzini 390c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 391c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 392c50d8ae3SPaolo Bonzini 393c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 394c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 395c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 396c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 397c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 398c50d8ae3SPaolo Bonzini 399c50d8ae3SPaolo Bonzini return orig.spte; 400c50d8ae3SPaolo Bonzini } 401c50d8ae3SPaolo Bonzini 402c50d8ae3SPaolo Bonzini /* 403c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 404c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 405c50d8ae3SPaolo Bonzini * 406c50d8ae3SPaolo Bonzini * An spte tlb flush may be pending, because kvm_set_pte_rmapp 407c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 408c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 409c50d8ae3SPaolo Bonzini * 410c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 411c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 412c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 413c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 414c50d8ae3SPaolo Bonzini * 415c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 416c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 417c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 418c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 419c50d8ae3SPaolo Bonzini */ 420c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 421c50d8ae3SPaolo Bonzini { 42257354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 423c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 424c50d8ae3SPaolo Bonzini int count; 425c50d8ae3SPaolo Bonzini 426c50d8ae3SPaolo Bonzini retry: 427c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 428c50d8ae3SPaolo Bonzini smp_rmb(); 429c50d8ae3SPaolo Bonzini 430c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 431c50d8ae3SPaolo Bonzini smp_rmb(); 432c50d8ae3SPaolo Bonzini 433c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 434c50d8ae3SPaolo Bonzini smp_rmb(); 435c50d8ae3SPaolo Bonzini 436c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 437c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 438c50d8ae3SPaolo Bonzini goto retry; 439c50d8ae3SPaolo Bonzini 440c50d8ae3SPaolo Bonzini return spte.spte; 441c50d8ae3SPaolo Bonzini } 442c50d8ae3SPaolo Bonzini #endif 443c50d8ae3SPaolo Bonzini 444c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 445c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 446c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 447c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 448c50d8ae3SPaolo Bonzini * the spte. 449c50d8ae3SPaolo Bonzini */ 450c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 451c50d8ae3SPaolo Bonzini { 452c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 453c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 454c50d8ae3SPaolo Bonzini } 455c50d8ae3SPaolo Bonzini 456c50d8ae3SPaolo Bonzini /* 457c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 458c50d8ae3SPaolo Bonzini * accessed/dirty status. 459c50d8ae3SPaolo Bonzini */ 460c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 461c50d8ae3SPaolo Bonzini { 462c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 463c50d8ae3SPaolo Bonzini 464c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 465115111efSDavid Matlack check_spte_writable_invariants(new_spte); 466c50d8ae3SPaolo Bonzini 467c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 468c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 469c50d8ae3SPaolo Bonzini return old_spte; 470c50d8ae3SPaolo Bonzini } 471c50d8ae3SPaolo Bonzini 472c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 473c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 474c50d8ae3SPaolo Bonzini else 475c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 476c50d8ae3SPaolo Bonzini 477c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 478c50d8ae3SPaolo Bonzini 479c50d8ae3SPaolo Bonzini return old_spte; 480c50d8ae3SPaolo Bonzini } 481c50d8ae3SPaolo Bonzini 482c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 483c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 484c50d8ae3SPaolo Bonzini * 48502844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 48602844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 48702844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 488c50d8ae3SPaolo Bonzini * 489c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 490c50d8ae3SPaolo Bonzini */ 491c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 492c50d8ae3SPaolo Bonzini { 493c50d8ae3SPaolo Bonzini bool flush = false; 494c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 495c50d8ae3SPaolo Bonzini 496c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 497c50d8ae3SPaolo Bonzini return false; 498c50d8ae3SPaolo Bonzini 499c50d8ae3SPaolo Bonzini /* 500c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 501c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 502c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 503c50d8ae3SPaolo Bonzini */ 504706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 505c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 506c50d8ae3SPaolo Bonzini flush = true; 507c50d8ae3SPaolo Bonzini 508c50d8ae3SPaolo Bonzini /* 509c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 510c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 511c50d8ae3SPaolo Bonzini */ 512c50d8ae3SPaolo Bonzini 513c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 514c50d8ae3SPaolo Bonzini flush = true; 515c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 516c50d8ae3SPaolo Bonzini } 517c50d8ae3SPaolo Bonzini 518c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 519c50d8ae3SPaolo Bonzini flush = true; 520c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 521c50d8ae3SPaolo Bonzini } 522c50d8ae3SPaolo Bonzini 523c50d8ae3SPaolo Bonzini return flush; 524c50d8ae3SPaolo Bonzini } 525c50d8ae3SPaolo Bonzini 526c50d8ae3SPaolo Bonzini /* 527c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 528c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 529c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5307fa2a347SSean Christopherson * Returns the old PTE. 531c50d8ae3SPaolo Bonzini */ 53271f51d2cSMingwei Zhang static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 533c50d8ae3SPaolo Bonzini { 534c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 535c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 53671f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 537b14b2690SSean Christopherson struct page *page; 538c50d8ae3SPaolo Bonzini 53954eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 54054eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 541c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 542c50d8ae3SPaolo Bonzini else 543c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 544c50d8ae3SPaolo Bonzini 545c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5467fa2a347SSean Christopherson return old_spte; 547c50d8ae3SPaolo Bonzini 54871f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 54971f51d2cSMingwei Zhang 550c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 551c50d8ae3SPaolo Bonzini 552c50d8ae3SPaolo Bonzini /* 553b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 554b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 555b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 556b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 557c50d8ae3SPaolo Bonzini */ 558b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 559b14b2690SSean Christopherson WARN_ON(page && !page_count(page)); 560c50d8ae3SPaolo Bonzini 561c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 562c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 563c50d8ae3SPaolo Bonzini 564c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 565c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 566c50d8ae3SPaolo Bonzini 5677fa2a347SSean Christopherson return old_spte; 568c50d8ae3SPaolo Bonzini } 569c50d8ae3SPaolo Bonzini 570c50d8ae3SPaolo Bonzini /* 571c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 572c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 573c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 574c50d8ae3SPaolo Bonzini */ 575c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 576c50d8ae3SPaolo Bonzini { 577c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 578c50d8ae3SPaolo Bonzini } 579c50d8ae3SPaolo Bonzini 580c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 581c50d8ae3SPaolo Bonzini { 582c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 583c50d8ae3SPaolo Bonzini } 584c50d8ae3SPaolo Bonzini 585c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 586c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 587c50d8ae3SPaolo Bonzini { 588c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 589c50d8ae3SPaolo Bonzini 590c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 591c50d8ae3SPaolo Bonzini return false; 592c50d8ae3SPaolo Bonzini 593c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 594c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 595c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 596c50d8ae3SPaolo Bonzini } else { 597c50d8ae3SPaolo Bonzini /* 598c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 599c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 600c50d8ae3SPaolo Bonzini */ 601c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 602c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 603c50d8ae3SPaolo Bonzini 604c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 605c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 606c50d8ae3SPaolo Bonzini } 607c50d8ae3SPaolo Bonzini 608c50d8ae3SPaolo Bonzini return true; 609c50d8ae3SPaolo Bonzini } 610c50d8ae3SPaolo Bonzini 611c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 612c50d8ae3SPaolo Bonzini { 613c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 614c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 615c5c8c7c5SDavid Matlack } else { 616c50d8ae3SPaolo Bonzini /* 617c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 618c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 619c50d8ae3SPaolo Bonzini */ 620c50d8ae3SPaolo Bonzini local_irq_disable(); 621c50d8ae3SPaolo Bonzini 622c50d8ae3SPaolo Bonzini /* 623c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 624c50d8ae3SPaolo Bonzini * to vcpu->mode. 625c50d8ae3SPaolo Bonzini */ 626c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 627c50d8ae3SPaolo Bonzini } 628c5c8c7c5SDavid Matlack } 629c50d8ae3SPaolo Bonzini 630c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 631c50d8ae3SPaolo Bonzini { 632c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 633c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 634c5c8c7c5SDavid Matlack } else { 635c50d8ae3SPaolo Bonzini /* 636c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 637c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 638c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 639c50d8ae3SPaolo Bonzini */ 640c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 641c50d8ae3SPaolo Bonzini local_irq_enable(); 642c50d8ae3SPaolo Bonzini } 643c5c8c7c5SDavid Matlack } 644c50d8ae3SPaolo Bonzini 645378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 646c50d8ae3SPaolo Bonzini { 647c50d8ae3SPaolo Bonzini int r; 648c50d8ae3SPaolo Bonzini 649531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 65094ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 651531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 652c50d8ae3SPaolo Bonzini if (r) 653c50d8ae3SPaolo Bonzini return r; 65494ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 655171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 656171a90d7SSean Christopherson if (r) 657171a90d7SSean Christopherson return r; 658378f5cd6SSean Christopherson if (maybe_indirect) { 6596a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 660171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 661c50d8ae3SPaolo Bonzini if (r) 662c50d8ae3SPaolo Bonzini return r; 663378f5cd6SSean Christopherson } 66494ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 665531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 666c50d8ae3SPaolo Bonzini } 667c50d8ae3SPaolo Bonzini 668c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 669c50d8ae3SPaolo Bonzini { 67094ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 67194ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 6726a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 67394ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 674c50d8ae3SPaolo Bonzini } 675c50d8ae3SPaolo Bonzini 676c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 677c50d8ae3SPaolo Bonzini { 678c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 679c50d8ae3SPaolo Bonzini } 680c50d8ae3SPaolo Bonzini 6816a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 6826a97575dSDavid Matlack 683c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 684c50d8ae3SPaolo Bonzini { 68584e5ffd0SLai Jiangshan if (sp->role.passthrough) 68684e5ffd0SLai Jiangshan return sp->gfn; 68784e5ffd0SLai Jiangshan 688c50d8ae3SPaolo Bonzini if (!sp->role.direct) 6896a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 690c50d8ae3SPaolo Bonzini 6912ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 692c50d8ae3SPaolo Bonzini } 693c50d8ae3SPaolo Bonzini 6946a97575dSDavid Matlack /* 6956a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 6966a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 6976a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 6986a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 6996a97575dSDavid Matlack */ 7006a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 701c50d8ae3SPaolo Bonzini { 7026a97575dSDavid Matlack if (sp_has_gptes(sp)) 7036a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7046a97575dSDavid Matlack 7056a97575dSDavid Matlack /* 7066a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7076a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7086a97575dSDavid Matlack * permissions" are just ACC_ALL. 7096a97575dSDavid Matlack * 7106a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7116a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7126a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7136a97575dSDavid Matlack * page. 7146a97575dSDavid Matlack * 7156a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7166a97575dSDavid Matlack */ 7176a97575dSDavid Matlack return sp->role.access; 7186a97575dSDavid Matlack } 7196a97575dSDavid Matlack 7206a97575dSDavid Matlack static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, gfn_t gfn, u32 access) 7216a97575dSDavid Matlack { 7226a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7236a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 72484e5ffd0SLai Jiangshan return; 72584e5ffd0SLai Jiangshan } 72684e5ffd0SLai Jiangshan 7276a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7286a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7296a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7306a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7316a97575dSDavid Matlack 7326a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7336a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7346a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7356a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 736c50d8ae3SPaolo Bonzini } 737c50d8ae3SPaolo Bonzini 7386a97575dSDavid Matlack static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, u32 access) 7396a97575dSDavid Matlack { 7406a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7416a97575dSDavid Matlack 7426a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 743c50d8ae3SPaolo Bonzini } 744c50d8ae3SPaolo Bonzini 745c50d8ae3SPaolo Bonzini /* 746c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 747c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 748c50d8ae3SPaolo Bonzini */ 749c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7508ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 751c50d8ae3SPaolo Bonzini { 752c50d8ae3SPaolo Bonzini unsigned long idx; 753c50d8ae3SPaolo Bonzini 754c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 755c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 756c50d8ae3SPaolo Bonzini } 757c50d8ae3SPaolo Bonzini 758269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 759c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 760c50d8ae3SPaolo Bonzini { 761c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 762c50d8ae3SPaolo Bonzini int i; 763c50d8ae3SPaolo Bonzini 7643bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 765c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 766c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 767c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 768c50d8ae3SPaolo Bonzini } 769c50d8ae3SPaolo Bonzini } 770c50d8ae3SPaolo Bonzini 771269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 772c50d8ae3SPaolo Bonzini { 773c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 774c50d8ae3SPaolo Bonzini } 775c50d8ae3SPaolo Bonzini 776269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 777c50d8ae3SPaolo Bonzini { 778c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 779c50d8ae3SPaolo Bonzini } 780c50d8ae3SPaolo Bonzini 781c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 782c50d8ae3SPaolo Bonzini { 783c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 784c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 785c50d8ae3SPaolo Bonzini gfn_t gfn; 786c50d8ae3SPaolo Bonzini 787c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 788c50d8ae3SPaolo Bonzini gfn = sp->gfn; 789c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 790c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 791c50d8ae3SPaolo Bonzini 792c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 7933bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 794c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 795c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 796c50d8ae3SPaolo Bonzini 797c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 798be911771SDavid Matlack 799be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 800be911771SDavid Matlack kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 801c50d8ae3SPaolo Bonzini } 802c50d8ae3SPaolo Bonzini 80329cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 804c50d8ae3SPaolo Bonzini { 805c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 806c50d8ae3SPaolo Bonzini return; 807c50d8ae3SPaolo Bonzini 808c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 809c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 810c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 811c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 812c50d8ae3SPaolo Bonzini } 813c50d8ae3SPaolo Bonzini 814c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 815c50d8ae3SPaolo Bonzini { 816c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 817c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 818c50d8ae3SPaolo Bonzini gfn_t gfn; 819c50d8ae3SPaolo Bonzini 820c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 821c50d8ae3SPaolo Bonzini gfn = sp->gfn; 822c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 823c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8243bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 825c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 826c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 827c50d8ae3SPaolo Bonzini 828c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 829c50d8ae3SPaolo Bonzini } 830c50d8ae3SPaolo Bonzini 83129cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 832c50d8ae3SPaolo Bonzini { 833c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 834c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 835c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 836c50d8ae3SPaolo Bonzini } 837c50d8ae3SPaolo Bonzini 838c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 839c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 840c50d8ae3SPaolo Bonzini bool no_dirty_log) 841c50d8ae3SPaolo Bonzini { 842c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 843c50d8ae3SPaolo Bonzini 844c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 84591b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 84691b0d268SPaolo Bonzini return NULL; 847044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 84891b0d268SPaolo Bonzini return NULL; 849c50d8ae3SPaolo Bonzini 850c50d8ae3SPaolo Bonzini return slot; 851c50d8ae3SPaolo Bonzini } 852c50d8ae3SPaolo Bonzini 853c50d8ae3SPaolo Bonzini /* 854c50d8ae3SPaolo Bonzini * About rmap_head encoding: 855c50d8ae3SPaolo Bonzini * 856c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 857c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 858c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 859c50d8ae3SPaolo Bonzini */ 860c50d8ae3SPaolo Bonzini 861c50d8ae3SPaolo Bonzini /* 862c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 863c50d8ae3SPaolo Bonzini */ 8642ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 865c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 866c50d8ae3SPaolo Bonzini { 867c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 86813236e25SPeter Xu int count = 0; 869c50d8ae3SPaolo Bonzini 870c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 871805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 872c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 873c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 874805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 8752ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 876c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 877c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 87813236e25SPeter Xu desc->spte_count = 2; 879c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 880c50d8ae3SPaolo Bonzini ++count; 881c50d8ae3SPaolo Bonzini } else { 882805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 883c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 88413236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 885c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 886c6c4f961SLi RongQing if (!desc->more) { 8872ff9039aSDavid Matlack desc->more = kvm_mmu_memory_cache_alloc(cache); 888c50d8ae3SPaolo Bonzini desc = desc->more; 88913236e25SPeter Xu desc->spte_count = 0; 890c6c4f961SLi RongQing break; 891c6c4f961SLi RongQing } 892c6c4f961SLi RongQing desc = desc->more; 893c50d8ae3SPaolo Bonzini } 89413236e25SPeter Xu count += desc->spte_count; 89513236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 896c50d8ae3SPaolo Bonzini } 897c50d8ae3SPaolo Bonzini return count; 898c50d8ae3SPaolo Bonzini } 899c50d8ae3SPaolo Bonzini 900c50d8ae3SPaolo Bonzini static void 901c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 902c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 903c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 904c50d8ae3SPaolo Bonzini { 90513236e25SPeter Xu int j = desc->spte_count - 1; 906c50d8ae3SPaolo Bonzini 907c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 908c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 90913236e25SPeter Xu desc->spte_count--; 91013236e25SPeter Xu if (desc->spte_count) 911c50d8ae3SPaolo Bonzini return; 912c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 913fe3c2b4cSMiaohe Lin rmap_head->val = 0; 914c50d8ae3SPaolo Bonzini else 915c50d8ae3SPaolo Bonzini if (prev_desc) 916c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 917c50d8ae3SPaolo Bonzini else 918c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 919c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 920c50d8ae3SPaolo Bonzini } 921c50d8ae3SPaolo Bonzini 922c50d8ae3SPaolo Bonzini static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 923c50d8ae3SPaolo Bonzini { 924c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 925c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 926c50d8ae3SPaolo Bonzini int i; 927c50d8ae3SPaolo Bonzini 928c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 929c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 930c50d8ae3SPaolo Bonzini BUG(); 931c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 932805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 933c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 934c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 935c50d8ae3SPaolo Bonzini BUG(); 936c50d8ae3SPaolo Bonzini } 937c50d8ae3SPaolo Bonzini rmap_head->val = 0; 938c50d8ae3SPaolo Bonzini } else { 939805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 940c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 941c50d8ae3SPaolo Bonzini prev_desc = NULL; 942c50d8ae3SPaolo Bonzini while (desc) { 94313236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 944c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 945c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 946c50d8ae3SPaolo Bonzini desc, i, prev_desc); 947c50d8ae3SPaolo Bonzini return; 948c50d8ae3SPaolo Bonzini } 949c50d8ae3SPaolo Bonzini } 950c50d8ae3SPaolo Bonzini prev_desc = desc; 951c50d8ae3SPaolo Bonzini desc = desc->more; 952c50d8ae3SPaolo Bonzini } 953c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 954c50d8ae3SPaolo Bonzini BUG(); 955c50d8ae3SPaolo Bonzini } 956c50d8ae3SPaolo Bonzini } 957c50d8ae3SPaolo Bonzini 95871f51d2cSMingwei Zhang static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 95971f51d2cSMingwei Zhang u64 *sptep) 960c50d8ae3SPaolo Bonzini { 96171f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 962c50d8ae3SPaolo Bonzini __pte_list_remove(sptep, rmap_head); 963c50d8ae3SPaolo Bonzini } 964c50d8ae3SPaolo Bonzini 965a75b5404SPeter Xu /* Return true if rmap existed, false otherwise */ 96671f51d2cSMingwei Zhang static bool pte_list_destroy(struct kvm *kvm, struct kvm_rmap_head *rmap_head) 967a75b5404SPeter Xu { 968a75b5404SPeter Xu struct pte_list_desc *desc, *next; 969a75b5404SPeter Xu int i; 970a75b5404SPeter Xu 971a75b5404SPeter Xu if (!rmap_head->val) 972a75b5404SPeter Xu return false; 973a75b5404SPeter Xu 974a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 97571f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 976a75b5404SPeter Xu goto out; 977a75b5404SPeter Xu } 978a75b5404SPeter Xu 979a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 980a75b5404SPeter Xu 981a75b5404SPeter Xu for (; desc; desc = next) { 982a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 98371f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 984a75b5404SPeter Xu next = desc->more; 985a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 986a75b5404SPeter Xu } 987a75b5404SPeter Xu out: 988a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 989a75b5404SPeter Xu rmap_head->val = 0; 990a75b5404SPeter Xu return true; 991a75b5404SPeter Xu } 992a75b5404SPeter Xu 9933bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 9943bcd0662SPeter Xu { 9953bcd0662SPeter Xu struct pte_list_desc *desc; 9963bcd0662SPeter Xu unsigned int count = 0; 9973bcd0662SPeter Xu 9983bcd0662SPeter Xu if (!rmap_head->val) 9993bcd0662SPeter Xu return 0; 10003bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10013bcd0662SPeter Xu return 1; 10023bcd0662SPeter Xu 10033bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10043bcd0662SPeter Xu 10053bcd0662SPeter Xu while (desc) { 10063bcd0662SPeter Xu count += desc->spte_count; 10073bcd0662SPeter Xu desc = desc->more; 10083bcd0662SPeter Xu } 10093bcd0662SPeter Xu 10103bcd0662SPeter Xu return count; 10113bcd0662SPeter Xu } 10123bcd0662SPeter Xu 101393e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1014269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1015c50d8ae3SPaolo Bonzini { 1016c50d8ae3SPaolo Bonzini unsigned long idx; 1017c50d8ae3SPaolo Bonzini 1018c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10193bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1020c50d8ae3SPaolo Bonzini } 1021c50d8ae3SPaolo Bonzini 1022c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1023c50d8ae3SPaolo Bonzini { 1024356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1025c50d8ae3SPaolo Bonzini 1026356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 102794ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1028c50d8ae3SPaolo Bonzini } 1029c50d8ae3SPaolo Bonzini 1030c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1031c50d8ae3SPaolo Bonzini { 1032601f8af0SDavid Matlack struct kvm_memslots *slots; 1033601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1034c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1035c50d8ae3SPaolo Bonzini gfn_t gfn; 1036c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1037c50d8ae3SPaolo Bonzini 103857354682SSean Christopherson sp = sptep_to_sp(spte); 1039c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt); 1040601f8af0SDavid Matlack 1041601f8af0SDavid Matlack /* 104268be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 104368be1306SDavid Matlack * so we have to determine which memslots to use based on context 104468be1306SDavid Matlack * information in sp->role. 1045601f8af0SDavid Matlack */ 1046601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1047601f8af0SDavid Matlack 1048601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 104993e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1050601f8af0SDavid Matlack 1051c50d8ae3SPaolo Bonzini __pte_list_remove(spte, rmap_head); 1052c50d8ae3SPaolo Bonzini } 1053c50d8ae3SPaolo Bonzini 1054c50d8ae3SPaolo Bonzini /* 1055c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1056c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1057c50d8ae3SPaolo Bonzini */ 1058c50d8ae3SPaolo Bonzini struct rmap_iterator { 1059c50d8ae3SPaolo Bonzini /* private fields */ 1060c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1061c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1062c50d8ae3SPaolo Bonzini }; 1063c50d8ae3SPaolo Bonzini 1064c50d8ae3SPaolo Bonzini /* 1065c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1066c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10670a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1068c50d8ae3SPaolo Bonzini * 1069c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1070c50d8ae3SPaolo Bonzini */ 1071c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1072c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1073c50d8ae3SPaolo Bonzini { 1074c50d8ae3SPaolo Bonzini u64 *sptep; 1075c50d8ae3SPaolo Bonzini 1076c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1077c50d8ae3SPaolo Bonzini return NULL; 1078c50d8ae3SPaolo Bonzini 1079c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1080c50d8ae3SPaolo Bonzini iter->desc = NULL; 1081c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1082c50d8ae3SPaolo Bonzini goto out; 1083c50d8ae3SPaolo Bonzini } 1084c50d8ae3SPaolo Bonzini 1085c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1086c50d8ae3SPaolo Bonzini iter->pos = 0; 1087c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1088c50d8ae3SPaolo Bonzini out: 1089c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1090c50d8ae3SPaolo Bonzini return sptep; 1091c50d8ae3SPaolo Bonzini } 1092c50d8ae3SPaolo Bonzini 1093c50d8ae3SPaolo Bonzini /* 1094c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1095c50d8ae3SPaolo Bonzini * 1096c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1097c50d8ae3SPaolo Bonzini */ 1098c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1099c50d8ae3SPaolo Bonzini { 1100c50d8ae3SPaolo Bonzini u64 *sptep; 1101c50d8ae3SPaolo Bonzini 1102c50d8ae3SPaolo Bonzini if (iter->desc) { 1103c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1104c50d8ae3SPaolo Bonzini ++iter->pos; 1105c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1106c50d8ae3SPaolo Bonzini if (sptep) 1107c50d8ae3SPaolo Bonzini goto out; 1108c50d8ae3SPaolo Bonzini } 1109c50d8ae3SPaolo Bonzini 1110c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1111c50d8ae3SPaolo Bonzini 1112c50d8ae3SPaolo Bonzini if (iter->desc) { 1113c50d8ae3SPaolo Bonzini iter->pos = 0; 1114c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1115c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1116c50d8ae3SPaolo Bonzini goto out; 1117c50d8ae3SPaolo Bonzini } 1118c50d8ae3SPaolo Bonzini } 1119c50d8ae3SPaolo Bonzini 1120c50d8ae3SPaolo Bonzini return NULL; 1121c50d8ae3SPaolo Bonzini out: 1122c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1123c50d8ae3SPaolo Bonzini return sptep; 1124c50d8ae3SPaolo Bonzini } 1125c50d8ae3SPaolo Bonzini 1126c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1127c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1128c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1129c50d8ae3SPaolo Bonzini 1130c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1131c50d8ae3SPaolo Bonzini { 113271f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11337fa2a347SSean Christopherson 11347fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1135c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1136c50d8ae3SPaolo Bonzini } 1137c50d8ae3SPaolo Bonzini 1138*03787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1139c50d8ae3SPaolo Bonzini { 11400cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 11410cd8dc73SPaolo Bonzini 11420cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 11430cd8dc73SPaolo Bonzini WARN_ON(sp->role.level == PG_LEVEL_4K); 11440cd8dc73SPaolo Bonzini 1145c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 1146*03787394SPaolo Bonzini 1147*03787394SPaolo Bonzini if (flush) 11480cd8dc73SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 1149c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1150c50d8ae3SPaolo Bonzini } 1151c50d8ae3SPaolo Bonzini 1152c50d8ae3SPaolo Bonzini /* 1153c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1154c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1155c50d8ae3SPaolo Bonzini * 1156c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1157c50d8ae3SPaolo Bonzini * protection: 1158c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1159c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1160c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1161c50d8ae3SPaolo Bonzini * shadow page. 1162c50d8ae3SPaolo Bonzini * 1163c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1164c50d8ae3SPaolo Bonzini */ 1165c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1166c50d8ae3SPaolo Bonzini { 1167c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1168c50d8ae3SPaolo Bonzini 1169c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1170706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1171c50d8ae3SPaolo Bonzini return false; 1172c50d8ae3SPaolo Bonzini 1173805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1174c50d8ae3SPaolo Bonzini 1175c50d8ae3SPaolo Bonzini if (pt_protect) 11765fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1177c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1178c50d8ae3SPaolo Bonzini 1179c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1180c50d8ae3SPaolo Bonzini } 1181c50d8ae3SPaolo Bonzini 11821346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1183c50d8ae3SPaolo Bonzini bool pt_protect) 1184c50d8ae3SPaolo Bonzini { 1185c50d8ae3SPaolo Bonzini u64 *sptep; 1186c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1187c50d8ae3SPaolo Bonzini bool flush = false; 1188c50d8ae3SPaolo Bonzini 1189c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1190c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1191c50d8ae3SPaolo Bonzini 1192c50d8ae3SPaolo Bonzini return flush; 1193c50d8ae3SPaolo Bonzini } 1194c50d8ae3SPaolo Bonzini 1195c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1196c50d8ae3SPaolo Bonzini { 1197c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1198c50d8ae3SPaolo Bonzini 1199805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1200c50d8ae3SPaolo Bonzini 1201c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1202c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1203c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1204c50d8ae3SPaolo Bonzini } 1205c50d8ae3SPaolo Bonzini 1206c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1207c50d8ae3SPaolo Bonzini { 1208c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1209c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1210c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1211c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1212c50d8ae3SPaolo Bonzini 1213c50d8ae3SPaolo Bonzini return was_writable; 1214c50d8ae3SPaolo Bonzini } 1215c50d8ae3SPaolo Bonzini 1216c50d8ae3SPaolo Bonzini /* 1217c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1218c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1219c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1220c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1221c50d8ae3SPaolo Bonzini */ 12220a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1223269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1224c50d8ae3SPaolo Bonzini { 1225c50d8ae3SPaolo Bonzini u64 *sptep; 1226c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1227c50d8ae3SPaolo Bonzini bool flush = false; 1228c50d8ae3SPaolo Bonzini 1229c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1230c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1231c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1232c50d8ae3SPaolo Bonzini else 1233c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1234c50d8ae3SPaolo Bonzini 1235c50d8ae3SPaolo Bonzini return flush; 1236c50d8ae3SPaolo Bonzini } 1237c50d8ae3SPaolo Bonzini 1238c50d8ae3SPaolo Bonzini /** 1239c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1240c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1241c50d8ae3SPaolo Bonzini * @slot: slot to protect 1242c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1243c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1244c50d8ae3SPaolo Bonzini * 124589212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1246c50d8ae3SPaolo Bonzini */ 1247c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1248c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1249c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1250c50d8ae3SPaolo Bonzini { 1251c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1252c50d8ae3SPaolo Bonzini 1253897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1254a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1255a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1256e2209710SBen Gardon 1257e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1258e2209710SBen Gardon return; 1259e2209710SBen Gardon 1260c50d8ae3SPaolo Bonzini while (mask) { 126193e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12623bae0459SSean Christopherson PG_LEVEL_4K, slot); 12631346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1264c50d8ae3SPaolo Bonzini 1265c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1266c50d8ae3SPaolo Bonzini mask &= mask - 1; 1267c50d8ae3SPaolo Bonzini } 1268c50d8ae3SPaolo Bonzini } 1269c50d8ae3SPaolo Bonzini 1270c50d8ae3SPaolo Bonzini /** 1271c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1272c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1273c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1274c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1275c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1276c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1277c50d8ae3SPaolo Bonzini * 1278c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1279c50d8ae3SPaolo Bonzini */ 1280a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1281c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1282c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1283c50d8ae3SPaolo Bonzini { 1284c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1285c50d8ae3SPaolo Bonzini 1286897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1287a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1288a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1289e2209710SBen Gardon 1290e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1291e2209710SBen Gardon return; 1292e2209710SBen Gardon 1293c50d8ae3SPaolo Bonzini while (mask) { 129493e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12953bae0459SSean Christopherson PG_LEVEL_4K, slot); 12960a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1297c50d8ae3SPaolo Bonzini 1298c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1299c50d8ae3SPaolo Bonzini mask &= mask - 1; 1300c50d8ae3SPaolo Bonzini } 1301c50d8ae3SPaolo Bonzini } 1302c50d8ae3SPaolo Bonzini 1303c50d8ae3SPaolo Bonzini /** 1304c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1305c50d8ae3SPaolo Bonzini * PT level pages. 1306c50d8ae3SPaolo Bonzini * 1307c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1308c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1309c50d8ae3SPaolo Bonzini * 131089212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 131189212919SKeqian Zhu * have such mappings. 1312c50d8ae3SPaolo Bonzini */ 1313c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1314c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1315c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1316c50d8ae3SPaolo Bonzini { 131789212919SKeqian Zhu /* 131889212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 131989212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 132089212919SKeqian Zhu * are split to 4K on the first write. 132189212919SKeqian Zhu * 132289212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 132389212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 132489212919SKeqian Zhu * pages. 132589212919SKeqian Zhu */ 132689212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 132789212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 132889212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 132989212919SKeqian Zhu 1330cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1331cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1332cb00a70bSDavid Matlack 133389212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 133489212919SKeqian Zhu 133589212919SKeqian Zhu /* Cross two large pages? */ 133689212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 133789212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 133889212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 133989212919SKeqian Zhu PG_LEVEL_2M); 134089212919SKeqian Zhu } 134189212919SKeqian Zhu 134289212919SKeqian Zhu /* Now handle 4K PTEs. */ 1343a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1344a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1345c50d8ae3SPaolo Bonzini else 1346c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1347c50d8ae3SPaolo Bonzini } 1348c50d8ae3SPaolo Bonzini 1349fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1350fb04a1edSPeter Xu { 13516dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1352fb04a1edSPeter Xu } 1353fb04a1edSPeter Xu 1354c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13553ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13563ad93562SKeqian Zhu int min_level) 1357c50d8ae3SPaolo Bonzini { 1358c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1359c50d8ae3SPaolo Bonzini int i; 1360c50d8ae3SPaolo Bonzini bool write_protected = false; 1361c50d8ae3SPaolo Bonzini 1362e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13633ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 136493e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13651346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1366c50d8ae3SPaolo Bonzini } 1367e2209710SBen Gardon } 1368c50d8ae3SPaolo Bonzini 1369897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 137046044f72SBen Gardon write_protected |= 13713ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 137246044f72SBen Gardon 1373c50d8ae3SPaolo Bonzini return write_protected; 1374c50d8ae3SPaolo Bonzini } 1375c50d8ae3SPaolo Bonzini 1376cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1377c50d8ae3SPaolo Bonzini { 1378c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1379c50d8ae3SPaolo Bonzini 1380c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 13813ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1382c50d8ae3SPaolo Bonzini } 1383c50d8ae3SPaolo Bonzini 13840a234f5dSSean Christopherson static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1385269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1386c50d8ae3SPaolo Bonzini { 138771f51d2cSMingwei Zhang return pte_list_destroy(kvm, rmap_head); 1388c50d8ae3SPaolo Bonzini } 1389c50d8ae3SPaolo Bonzini 13903039bcc7SSean Christopherson static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1391c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 13923039bcc7SSean Christopherson pte_t unused) 1393c50d8ae3SPaolo Bonzini { 13940a234f5dSSean Christopherson return kvm_zap_rmapp(kvm, rmap_head, slot); 1395c50d8ae3SPaolo Bonzini } 1396c50d8ae3SPaolo Bonzini 13973039bcc7SSean Christopherson static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1398c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 13993039bcc7SSean Christopherson pte_t pte) 1400c50d8ae3SPaolo Bonzini { 1401c50d8ae3SPaolo Bonzini u64 *sptep; 1402c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 140398a26b69SVihas Mak bool need_flush = false; 1404c50d8ae3SPaolo Bonzini u64 new_spte; 1405c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1406c50d8ae3SPaolo Bonzini 14073039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14083039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1409c50d8ae3SPaolo Bonzini 1410c50d8ae3SPaolo Bonzini restart: 1411c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1412805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1413c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1414c50d8ae3SPaolo Bonzini 141598a26b69SVihas Mak need_flush = true; 1416c50d8ae3SPaolo Bonzini 14173039bcc7SSean Christopherson if (pte_write(pte)) { 141871f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 1419c50d8ae3SPaolo Bonzini goto restart; 1420c50d8ae3SPaolo Bonzini } else { 1421cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1422cb3eedabSPaolo Bonzini *sptep, new_pfn); 1423c50d8ae3SPaolo Bonzini 142471f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1425c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1426c50d8ae3SPaolo Bonzini } 1427c50d8ae3SPaolo Bonzini } 1428c50d8ae3SPaolo Bonzini 1429c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1430c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 143198a26b69SVihas Mak return false; 1432c50d8ae3SPaolo Bonzini } 1433c50d8ae3SPaolo Bonzini 1434c50d8ae3SPaolo Bonzini return need_flush; 1435c50d8ae3SPaolo Bonzini } 1436c50d8ae3SPaolo Bonzini 1437c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1438c50d8ae3SPaolo Bonzini /* input fields. */ 1439269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1440c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1441c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1442c50d8ae3SPaolo Bonzini int start_level; 1443c50d8ae3SPaolo Bonzini int end_level; 1444c50d8ae3SPaolo Bonzini 1445c50d8ae3SPaolo Bonzini /* output fields. */ 1446c50d8ae3SPaolo Bonzini gfn_t gfn; 1447c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1448c50d8ae3SPaolo Bonzini int level; 1449c50d8ae3SPaolo Bonzini 1450c50d8ae3SPaolo Bonzini /* private field. */ 1451c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1452c50d8ae3SPaolo Bonzini }; 1453c50d8ae3SPaolo Bonzini 1454c50d8ae3SPaolo Bonzini static void 1455c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1456c50d8ae3SPaolo Bonzini { 1457c50d8ae3SPaolo Bonzini iterator->level = level; 1458c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 145993e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 146093e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1461c50d8ae3SPaolo Bonzini } 1462c50d8ae3SPaolo Bonzini 1463c50d8ae3SPaolo Bonzini static void 1464c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1465269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1466c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1467c50d8ae3SPaolo Bonzini { 1468c50d8ae3SPaolo Bonzini iterator->slot = slot; 1469c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1470c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1471c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1472c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1473c50d8ae3SPaolo Bonzini 1474c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1475c50d8ae3SPaolo Bonzini } 1476c50d8ae3SPaolo Bonzini 1477c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1478c50d8ae3SPaolo Bonzini { 1479c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1480c50d8ae3SPaolo Bonzini } 1481c50d8ae3SPaolo Bonzini 1482c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1483c50d8ae3SPaolo Bonzini { 14846ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1485c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 14866ba1e04fSVipin Sharma 14876ba1e04fSVipin Sharma if (iterator->rmap->val) 1488c50d8ae3SPaolo Bonzini return; 1489c50d8ae3SPaolo Bonzini } 1490c50d8ae3SPaolo Bonzini 1491c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1492c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1493c50d8ae3SPaolo Bonzini return; 1494c50d8ae3SPaolo Bonzini } 1495c50d8ae3SPaolo Bonzini 1496c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1497c50d8ae3SPaolo Bonzini } 1498c50d8ae3SPaolo Bonzini 1499c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1500c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1501c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1502c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1503c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1504c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1505c50d8ae3SPaolo Bonzini 15063039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1507c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15083039bcc7SSean Christopherson int level, pte_t pte); 1509c1b91493SSean Christopherson 15103039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15113039bcc7SSean Christopherson struct kvm_gfn_range *range, 1512c1b91493SSean Christopherson rmap_handler_t handler) 1513c50d8ae3SPaolo Bonzini { 1514c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15153039bcc7SSean Christopherson bool ret = false; 1516c50d8ae3SPaolo Bonzini 15173039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15183039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15193039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15203039bcc7SSean Christopherson iterator.level, range->pte); 1521c50d8ae3SPaolo Bonzini 1522c50d8ae3SPaolo Bonzini return ret; 1523c50d8ae3SPaolo Bonzini } 1524c50d8ae3SPaolo Bonzini 15253039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1526c50d8ae3SPaolo Bonzini { 1527e2209710SBen Gardon bool flush = false; 1528c50d8ae3SPaolo Bonzini 1529e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15303039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp); 1531063afacdSBen Gardon 1532897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1533c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1534063afacdSBen Gardon 15353039bcc7SSean Christopherson return flush; 1536c50d8ae3SPaolo Bonzini } 1537c50d8ae3SPaolo Bonzini 15383039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1539c50d8ae3SPaolo Bonzini { 1540e2209710SBen Gardon bool flush = false; 15411d8dd6b3SBen Gardon 1542e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15433039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp); 15441d8dd6b3SBen Gardon 1545897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15463039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15471d8dd6b3SBen Gardon 15483039bcc7SSean Christopherson return flush; 1549c50d8ae3SPaolo Bonzini } 1550c50d8ae3SPaolo Bonzini 15513039bcc7SSean Christopherson static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1552c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15533039bcc7SSean Christopherson pte_t unused) 1554c50d8ae3SPaolo Bonzini { 1555c50d8ae3SPaolo Bonzini u64 *sptep; 15563f649ab7SKees Cook struct rmap_iterator iter; 1557c50d8ae3SPaolo Bonzini int young = 0; 1558c50d8ae3SPaolo Bonzini 1559c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1560c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1561c50d8ae3SPaolo Bonzini 1562c50d8ae3SPaolo Bonzini return young; 1563c50d8ae3SPaolo Bonzini } 1564c50d8ae3SPaolo Bonzini 15653039bcc7SSean Christopherson static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1566c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15673039bcc7SSean Christopherson int level, pte_t unused) 1568c50d8ae3SPaolo Bonzini { 1569c50d8ae3SPaolo Bonzini u64 *sptep; 1570c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1571c50d8ae3SPaolo Bonzini 1572c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1573c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 157498a26b69SVihas Mak return true; 157598a26b69SVihas Mak return false; 1576c50d8ae3SPaolo Bonzini } 1577c50d8ae3SPaolo Bonzini 1578c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1579c50d8ae3SPaolo Bonzini 15802ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 15812ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 15822ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 15836a97575dSDavid Matlack u64 *spte, gfn_t gfn, u32 access) 1584c50d8ae3SPaolo Bonzini { 1585c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 158668be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 158768be1306SDavid Matlack int rmap_count; 1588c50d8ae3SPaolo Bonzini 158957354682SSean Christopherson sp = sptep_to_sp(spte); 15906a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, spte - sp->spt, gfn, access); 159181cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 159281cb4657SDavid Matlack 159393e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 15942ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1595c50d8ae3SPaolo Bonzini 159668be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 15972ff9039aSDavid Matlack kvm_unmap_rmapp(kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0)); 159868be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 15992ff9039aSDavid Matlack kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 160068be1306SDavid Matlack } 1601c50d8ae3SPaolo Bonzini } 1602c50d8ae3SPaolo Bonzini 16032ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 16046a97575dSDavid Matlack u64 *spte, gfn_t gfn, u32 access) 16052ff9039aSDavid Matlack { 16062ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16072ff9039aSDavid Matlack 16086a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16092ff9039aSDavid Matlack } 16102ff9039aSDavid Matlack 16113039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1612c50d8ae3SPaolo Bonzini { 1613e2209710SBen Gardon bool young = false; 1614f8e14497SBen Gardon 1615e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16163039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp); 16173039bcc7SSean Christopherson 1618897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16193039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1620f8e14497SBen Gardon 1621f8e14497SBen Gardon return young; 1622c50d8ae3SPaolo Bonzini } 1623c50d8ae3SPaolo Bonzini 16243039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1625c50d8ae3SPaolo Bonzini { 1626e2209710SBen Gardon bool young = false; 1627f8e14497SBen Gardon 1628e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16293039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp); 16303039bcc7SSean Christopherson 1631897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16323039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1633f8e14497SBen Gardon 1634f8e14497SBen Gardon return young; 1635c50d8ae3SPaolo Bonzini } 1636c50d8ae3SPaolo Bonzini 1637c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1638c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1639c50d8ae3SPaolo Bonzini { 1640c50d8ae3SPaolo Bonzini u64 *pos; 1641c50d8ae3SPaolo Bonzini u64 *end; 1642c50d8ae3SPaolo Bonzini 1643c50d8ae3SPaolo Bonzini for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) 1644c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1645c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1646c50d8ae3SPaolo Bonzini pos, *pos); 1647c50d8ae3SPaolo Bonzini return 0; 1648c50d8ae3SPaolo Bonzini } 1649c50d8ae3SPaolo Bonzini return 1; 1650c50d8ae3SPaolo Bonzini } 1651c50d8ae3SPaolo Bonzini #endif 1652c50d8ae3SPaolo Bonzini 1653c50d8ae3SPaolo Bonzini /* 1654c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1655c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1656c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1657c50d8ae3SPaolo Bonzini * faster 1658c50d8ae3SPaolo Bonzini */ 1659d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1660c50d8ae3SPaolo Bonzini { 1661c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1662c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1663c50d8ae3SPaolo Bonzini } 1664c50d8ae3SPaolo Bonzini 166587654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1666c50d8ae3SPaolo Bonzini { 1667c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1668c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1669c50d8ae3SPaolo Bonzini list_del(&sp->link); 1670c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1671c50d8ae3SPaolo Bonzini if (!sp->role.direct) 16726a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1673c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1674c50d8ae3SPaolo Bonzini } 1675c50d8ae3SPaolo Bonzini 1676c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1677c50d8ae3SPaolo Bonzini { 1678c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1679c50d8ae3SPaolo Bonzini } 1680c50d8ae3SPaolo Bonzini 16812ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1682c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1683c50d8ae3SPaolo Bonzini { 1684c50d8ae3SPaolo Bonzini if (!parent_pte) 1685c50d8ae3SPaolo Bonzini return; 1686c50d8ae3SPaolo Bonzini 16872ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1688c50d8ae3SPaolo Bonzini } 1689c50d8ae3SPaolo Bonzini 1690c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1691c50d8ae3SPaolo Bonzini u64 *parent_pte) 1692c50d8ae3SPaolo Bonzini { 1693c50d8ae3SPaolo Bonzini __pte_list_remove(parent_pte, &sp->parent_ptes); 1694c50d8ae3SPaolo Bonzini } 1695c50d8ae3SPaolo Bonzini 1696c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1697c50d8ae3SPaolo Bonzini u64 *parent_pte) 1698c50d8ae3SPaolo Bonzini { 1699c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1700c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1701c50d8ae3SPaolo Bonzini } 1702c50d8ae3SPaolo Bonzini 1703c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1704c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1705c50d8ae3SPaolo Bonzini { 1706c50d8ae3SPaolo Bonzini u64 *sptep; 1707c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1708c50d8ae3SPaolo Bonzini 1709c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1710c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1711c50d8ae3SPaolo Bonzini } 1712c50d8ae3SPaolo Bonzini } 1713c50d8ae3SPaolo Bonzini 1714c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1715c50d8ae3SPaolo Bonzini { 1716c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1717c50d8ae3SPaolo Bonzini unsigned int index; 1718c50d8ae3SPaolo Bonzini 171957354682SSean Christopherson sp = sptep_to_sp(spte); 1720c50d8ae3SPaolo Bonzini index = spte - sp->spt; 1721c50d8ae3SPaolo Bonzini if (__test_and_set_bit(index, sp->unsync_child_bitmap)) 1722c50d8ae3SPaolo Bonzini return; 1723c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1724c50d8ae3SPaolo Bonzini return; 1725c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1726c50d8ae3SPaolo Bonzini } 1727c50d8ae3SPaolo Bonzini 1728c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1729c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1730c50d8ae3SPaolo Bonzini { 1731c3e5e415SLai Jiangshan return -1; 1732c50d8ae3SPaolo Bonzini } 1733c50d8ae3SPaolo Bonzini 1734c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1735c50d8ae3SPaolo Bonzini 1736c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1737c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1738c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1739c50d8ae3SPaolo Bonzini unsigned int idx; 1740c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1741c50d8ae3SPaolo Bonzini unsigned int nr; 1742c50d8ae3SPaolo Bonzini }; 1743c50d8ae3SPaolo Bonzini 1744c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1745c50d8ae3SPaolo Bonzini int idx) 1746c50d8ae3SPaolo Bonzini { 1747c50d8ae3SPaolo Bonzini int i; 1748c50d8ae3SPaolo Bonzini 1749c50d8ae3SPaolo Bonzini if (sp->unsync) 1750c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1751c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1752c50d8ae3SPaolo Bonzini return 0; 1753c50d8ae3SPaolo Bonzini 1754c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1755c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1756c50d8ae3SPaolo Bonzini pvec->nr++; 1757c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1758c50d8ae3SPaolo Bonzini } 1759c50d8ae3SPaolo Bonzini 1760c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1761c50d8ae3SPaolo Bonzini { 1762c50d8ae3SPaolo Bonzini --sp->unsync_children; 1763c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1764c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1765c50d8ae3SPaolo Bonzini } 1766c50d8ae3SPaolo Bonzini 1767c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1768c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1769c50d8ae3SPaolo Bonzini { 1770c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1771c50d8ae3SPaolo Bonzini 1772c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1773c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1774c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1775c50d8ae3SPaolo Bonzini 1776c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1777c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1778c50d8ae3SPaolo Bonzini continue; 1779c50d8ae3SPaolo Bonzini } 1780c50d8ae3SPaolo Bonzini 17812ca3129eSSean Christopherson child = to_shadow_page(ent & SPTE_BASE_ADDR_MASK); 1782c50d8ae3SPaolo Bonzini 1783c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1784c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1785c50d8ae3SPaolo Bonzini return -ENOSPC; 1786c50d8ae3SPaolo Bonzini 1787c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1788c50d8ae3SPaolo Bonzini if (!ret) { 1789c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1790c50d8ae3SPaolo Bonzini continue; 1791c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1792c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1793c50d8ae3SPaolo Bonzini } else 1794c50d8ae3SPaolo Bonzini return ret; 1795c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1796c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1797c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1798c50d8ae3SPaolo Bonzini return -ENOSPC; 1799c50d8ae3SPaolo Bonzini } else 1800c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1801c50d8ae3SPaolo Bonzini } 1802c50d8ae3SPaolo Bonzini 1803c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1804c50d8ae3SPaolo Bonzini } 1805c50d8ae3SPaolo Bonzini 1806c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1807c50d8ae3SPaolo Bonzini 1808c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1809c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1810c50d8ae3SPaolo Bonzini { 1811c50d8ae3SPaolo Bonzini pvec->nr = 0; 1812c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1813c50d8ae3SPaolo Bonzini return 0; 1814c50d8ae3SPaolo Bonzini 1815c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1816c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1817c50d8ae3SPaolo Bonzini } 1818c50d8ae3SPaolo Bonzini 1819c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1820c50d8ae3SPaolo Bonzini { 1821c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1822c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1823c50d8ae3SPaolo Bonzini sp->unsync = 0; 1824c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1825c50d8ae3SPaolo Bonzini } 1826c50d8ae3SPaolo Bonzini 1827c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1828c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1829c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1830c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1831c50d8ae3SPaolo Bonzini 1832767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1833767d8d8dSLai Jiangshan { 1834767d8d8dSLai Jiangshan if (sp->role.direct) 1835767d8d8dSLai Jiangshan return false; 1836767d8d8dSLai Jiangshan 183784e5ffd0SLai Jiangshan if (sp->role.passthrough) 183884e5ffd0SLai Jiangshan return false; 183984e5ffd0SLai Jiangshan 1840767d8d8dSLai Jiangshan return true; 1841767d8d8dSLai Jiangshan } 1842767d8d8dSLai Jiangshan 1843ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1844ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1845c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1846c50d8ae3SPaolo Bonzini } else 1847c50d8ae3SPaolo Bonzini 1848767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1849ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1850ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1851767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1852c50d8ae3SPaolo Bonzini 18538d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1854c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1855c50d8ae3SPaolo Bonzini { 1856c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1857c3e5e415SLai Jiangshan 18588d5678a7SHou Wenlong if (ret < 0) 1859c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18608d5678a7SHou Wenlong return ret; 1861c50d8ae3SPaolo Bonzini } 1862c50d8ae3SPaolo Bonzini 1863c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1864c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1865c50d8ae3SPaolo Bonzini bool remote_flush) 1866c50d8ae3SPaolo Bonzini { 1867c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1868c50d8ae3SPaolo Bonzini return false; 1869c50d8ae3SPaolo Bonzini 1870c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1871c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1872c50d8ae3SPaolo Bonzini else 1873c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1874c50d8ae3SPaolo Bonzini return true; 1875c50d8ae3SPaolo Bonzini } 1876c50d8ae3SPaolo Bonzini 1877c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1878c50d8ae3SPaolo Bonzini { 1879a955cad8SSean Christopherson if (sp->role.invalid) 1880a955cad8SSean Christopherson return true; 1881a955cad8SSean Christopherson 1882a955cad8SSean Christopherson /* TDP MMU pages due not use the MMU generation. */ 1883a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1884c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1885c50d8ae3SPaolo Bonzini } 1886c50d8ae3SPaolo Bonzini 1887c50d8ae3SPaolo Bonzini struct mmu_page_path { 1888c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1889c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1890c50d8ae3SPaolo Bonzini }; 1891c50d8ae3SPaolo Bonzini 1892c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1893c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1894c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1895c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1896c50d8ae3SPaolo Bonzini 1897c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1898c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1899c50d8ae3SPaolo Bonzini int i) 1900c50d8ae3SPaolo Bonzini { 1901c50d8ae3SPaolo Bonzini int n; 1902c50d8ae3SPaolo Bonzini 1903c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1904c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1905c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1906c50d8ae3SPaolo Bonzini int level = sp->role.level; 1907c50d8ae3SPaolo Bonzini 1908c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19093bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1910c50d8ae3SPaolo Bonzini break; 1911c50d8ae3SPaolo Bonzini 1912c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1913c50d8ae3SPaolo Bonzini } 1914c50d8ae3SPaolo Bonzini 1915c50d8ae3SPaolo Bonzini return n; 1916c50d8ae3SPaolo Bonzini } 1917c50d8ae3SPaolo Bonzini 1918c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1919c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1920c50d8ae3SPaolo Bonzini { 1921c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1922c50d8ae3SPaolo Bonzini int level; 1923c50d8ae3SPaolo Bonzini 1924c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1925c50d8ae3SPaolo Bonzini return 0; 1926c50d8ae3SPaolo Bonzini 1927c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1928c50d8ae3SPaolo Bonzini 1929c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1930c50d8ae3SPaolo Bonzini level = sp->role.level; 19313bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1932c50d8ae3SPaolo Bonzini 1933c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1934c50d8ae3SPaolo Bonzini 1935c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1936c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1937c50d8ae3SPaolo Bonzini */ 1938c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1939c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1940c50d8ae3SPaolo Bonzini } 1941c50d8ae3SPaolo Bonzini 1942c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1943c50d8ae3SPaolo Bonzini { 1944c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1945c50d8ae3SPaolo Bonzini unsigned int level = 0; 1946c50d8ae3SPaolo Bonzini 1947c50d8ae3SPaolo Bonzini do { 1948c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1949c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1950c50d8ae3SPaolo Bonzini if (!sp) 1951c50d8ae3SPaolo Bonzini return; 1952c50d8ae3SPaolo Bonzini 1953c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1954c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1955c50d8ae3SPaolo Bonzini level++; 1956c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1957c50d8ae3SPaolo Bonzini } 1958c50d8ae3SPaolo Bonzini 195965855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 196065855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1961c50d8ae3SPaolo Bonzini { 1962c50d8ae3SPaolo Bonzini int i; 1963c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1964c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1965c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1966c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1967c50d8ae3SPaolo Bonzini bool flush = false; 1968c50d8ae3SPaolo Bonzini 1969c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 1970c50d8ae3SPaolo Bonzini bool protected = false; 1971c50d8ae3SPaolo Bonzini 1972c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 1973cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 1974c50d8ae3SPaolo Bonzini 1975c50d8ae3SPaolo Bonzini if (protected) { 19765591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 1977c50d8ae3SPaolo Bonzini flush = false; 1978c50d8ae3SPaolo Bonzini } 1979c50d8ae3SPaolo Bonzini 1980c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 1981479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 19828d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 1983c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 1984c50d8ae3SPaolo Bonzini } 1985531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 1986c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 198765855ed8SLai Jiangshan if (!can_yield) { 198865855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 198965855ed8SLai Jiangshan return -EINTR; 199065855ed8SLai Jiangshan } 199165855ed8SLai Jiangshan 1992531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 1993c50d8ae3SPaolo Bonzini flush = false; 1994c50d8ae3SPaolo Bonzini } 1995c50d8ae3SPaolo Bonzini } 1996c50d8ae3SPaolo Bonzini 1997c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 199865855ed8SLai Jiangshan return 0; 1999c50d8ae3SPaolo Bonzini } 2000c50d8ae3SPaolo Bonzini 2001c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2002c50d8ae3SPaolo Bonzini { 2003c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2004c50d8ae3SPaolo Bonzini } 2005c50d8ae3SPaolo Bonzini 2006c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2007c50d8ae3SPaolo Bonzini { 200857354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2009c50d8ae3SPaolo Bonzini } 2010c50d8ae3SPaolo Bonzini 2011cbd858b1SDavid Matlack /* 2012cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2013cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2014cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2015cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2016cbd858b1SDavid Matlack */ 20173cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 20183cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 201994c81364SDavid Matlack gfn_t gfn, 202094c81364SDavid Matlack struct hlist_head *sp_list, 20212e65e842SDavid Matlack union kvm_mmu_page_role role) 2022c50d8ae3SPaolo Bonzini { 2023c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20248d5678a7SHou Wenlong int ret; 2025c50d8ae3SPaolo Bonzini int collisions = 0; 2026c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2027c50d8ae3SPaolo Bonzini 20283cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2029c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2030c50d8ae3SPaolo Bonzini collisions++; 2031c50d8ae3SPaolo Bonzini continue; 2032c50d8ae3SPaolo Bonzini } 2033c50d8ae3SPaolo Bonzini 2034ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2035ddc16abbSSean Christopherson /* 2036ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2037ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2038ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2039ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2040ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2041ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2042ddc16abbSSean Christopherson * upper-level page will be write-protected. 2043ddc16abbSSean Christopherson */ 20442e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 20453cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2046ddc16abbSSean Christopherson &invalid_list); 2047c50d8ae3SPaolo Bonzini continue; 2048ddc16abbSSean Christopherson } 2049c50d8ae3SPaolo Bonzini 2050bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2051bb924ca6SDavid Matlack if (sp->role.direct) 205294c81364SDavid Matlack goto out; 2053fb58a9c3SSean Christopherson 2054c50d8ae3SPaolo Bonzini if (sp->unsync) { 2055cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2056cbd858b1SDavid Matlack break; 2057cbd858b1SDavid Matlack 205807dc4f35SSean Christopherson /* 2059479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 206007dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 206107dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 206207dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 206307dc4f35SSean Christopherson * overhead of write protection is not incurred until the 206407dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 206507dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 206607dc4f35SSean Christopherson * 206707dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 206807dc4f35SSean Christopherson * in order to rebuild it. 2069c50d8ae3SPaolo Bonzini */ 20708d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 20718d5678a7SHou Wenlong if (ret < 0) 2072c50d8ae3SPaolo Bonzini break; 2073c50d8ae3SPaolo Bonzini 2074c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 20758d5678a7SHou Wenlong if (ret > 0) 20763cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2077c50d8ae3SPaolo Bonzini } 2078c50d8ae3SPaolo Bonzini 2079c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2080fb58a9c3SSean Christopherson 2081c50d8ae3SPaolo Bonzini goto out; 2082c50d8ae3SPaolo Bonzini } 2083c50d8ae3SPaolo Bonzini 208494c81364SDavid Matlack sp = NULL; 20853cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2086c50d8ae3SPaolo Bonzini 208794c81364SDavid Matlack out: 20883cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 208994c81364SDavid Matlack 20903cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 20913cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 209294c81364SDavid Matlack return sp; 209394c81364SDavid Matlack } 209494c81364SDavid Matlack 20952f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 20962f8b1b53SDavid Matlack struct shadow_page_caches { 20972f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 20982f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 20996a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 21002f8b1b53SDavid Matlack }; 21012f8b1b53SDavid Matlack 2102336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 21032f8b1b53SDavid Matlack struct shadow_page_caches *caches, 210494c81364SDavid Matlack gfn_t gfn, 210594c81364SDavid Matlack struct hlist_head *sp_list, 210694c81364SDavid Matlack union kvm_mmu_page_role role) 210794c81364SDavid Matlack { 2108c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2109c306aec8SDavid Matlack 21102f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 21112f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2112c306aec8SDavid Matlack if (!role.direct) 21136a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2114c306aec8SDavid Matlack 2115c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2116c306aec8SDavid Matlack 2117c306aec8SDavid Matlack /* 2118c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2119c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2120c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2121c306aec8SDavid Matlack */ 2122336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2123336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 2124336081fbSDavid Matlack kvm_mod_used_mmu_pages(kvm, +1); 2125c50d8ae3SPaolo Bonzini 2126c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2127c50d8ae3SPaolo Bonzini sp->role = role; 2128ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2129be911771SDavid Matlack if (sp_has_gptes(sp)) 2130336081fbSDavid Matlack account_shadowed(kvm, sp); 2131ddc16abbSSean Christopherson 213294c81364SDavid Matlack return sp; 213394c81364SDavid Matlack } 213494c81364SDavid Matlack 2135cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 21363cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 21373cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 21382f8b1b53SDavid Matlack struct shadow_page_caches *caches, 213987654643SDavid Matlack gfn_t gfn, 214094c81364SDavid Matlack union kvm_mmu_page_role role) 214194c81364SDavid Matlack { 214294c81364SDavid Matlack struct hlist_head *sp_list; 214394c81364SDavid Matlack struct kvm_mmu_page *sp; 214494c81364SDavid Matlack bool created = false; 214594c81364SDavid Matlack 21463cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 214794c81364SDavid Matlack 21483cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 214994c81364SDavid Matlack if (!sp) { 215094c81364SDavid Matlack created = true; 21513cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 215294c81364SDavid Matlack } 215394c81364SDavid Matlack 215494c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2155c50d8ae3SPaolo Bonzini return sp; 2156c50d8ae3SPaolo Bonzini } 2157c50d8ae3SPaolo Bonzini 21582f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 21592f8b1b53SDavid Matlack gfn_t gfn, 21602f8b1b53SDavid Matlack union kvm_mmu_page_role role) 21612f8b1b53SDavid Matlack { 21622f8b1b53SDavid Matlack struct shadow_page_caches caches = { 21632f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 21642f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 21656a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 21662f8b1b53SDavid Matlack }; 21672f8b1b53SDavid Matlack 21683cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 21692f8b1b53SDavid Matlack } 21702f8b1b53SDavid Matlack 21712e65e842SDavid Matlack static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, unsigned int access) 21722e65e842SDavid Matlack { 21732e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 21742e65e842SDavid Matlack union kvm_mmu_page_role role; 21752e65e842SDavid Matlack 21762e65e842SDavid Matlack role = parent_sp->role; 21772e65e842SDavid Matlack role.level--; 21782e65e842SDavid Matlack role.access = access; 21792e65e842SDavid Matlack role.direct = direct; 21802e65e842SDavid Matlack role.passthrough = 0; 21812e65e842SDavid Matlack 21822e65e842SDavid Matlack /* 21832e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 21842e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 21852e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 21862e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 21872e65e842SDavid Matlack * requires extra bookkeeping in the role. 21882e65e842SDavid Matlack * 21892e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 21902e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 21912e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 21922e65e842SDavid Matlack * the address space each maps. 21932e65e842SDavid Matlack * 21942e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 21952e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 21962e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 21972e65e842SDavid Matlack * 21982e65e842SDavid Matlack * Note, the 4 PAE page directories are pre-allocated and the quadrant 21992e65e842SDavid Matlack * assigned in mmu_alloc_root(). So only page tables need to be handled 22002e65e842SDavid Matlack * here. 22012e65e842SDavid Matlack */ 22022e65e842SDavid Matlack if (role.has_4_byte_gpte) { 22032e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 22042e65e842SDavid Matlack role.quadrant = (sptep - parent_sp->spt) % 2; 22052e65e842SDavid Matlack } 22062e65e842SDavid Matlack 22072e65e842SDavid Matlack return role; 22082e65e842SDavid Matlack } 22092e65e842SDavid Matlack 22102e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 22112e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 22122e65e842SDavid Matlack bool direct, unsigned int access) 22132e65e842SDavid Matlack { 22142e65e842SDavid Matlack union kvm_mmu_page_role role; 22152e65e842SDavid Matlack 22160cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 22170cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 22180cd8dc73SPaolo Bonzini 22192e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 222087654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 22212e65e842SDavid Matlack } 22222e65e842SDavid Matlack 2223c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2224c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2225c50d8ae3SPaolo Bonzini u64 addr) 2226c50d8ae3SPaolo Bonzini { 2227c50d8ae3SPaolo Bonzini iterator->addr = addr; 2228c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2229a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2230c50d8ae3SPaolo Bonzini 223112ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 22324d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2233347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 223412ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2235c50d8ae3SPaolo Bonzini 2236c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2237c50d8ae3SPaolo Bonzini /* 2238c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2239c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2240c50d8ae3SPaolo Bonzini */ 2241b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2242c50d8ae3SPaolo Bonzini 2243c50d8ae3SPaolo Bonzini iterator->shadow_addr 2244c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 22452ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2246c50d8ae3SPaolo Bonzini --iterator->level; 2247c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2248c50d8ae3SPaolo Bonzini iterator->level = 0; 2249c50d8ae3SPaolo Bonzini } 2250c50d8ae3SPaolo Bonzini } 2251c50d8ae3SPaolo Bonzini 2252c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2253c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2254c50d8ae3SPaolo Bonzini { 2255b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2256c50d8ae3SPaolo Bonzini addr); 2257c50d8ae3SPaolo Bonzini } 2258c50d8ae3SPaolo Bonzini 2259c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2260c50d8ae3SPaolo Bonzini { 22613bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2262c50d8ae3SPaolo Bonzini return false; 2263c50d8ae3SPaolo Bonzini 22642ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2265c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2266c50d8ae3SPaolo Bonzini return true; 2267c50d8ae3SPaolo Bonzini } 2268c50d8ae3SPaolo Bonzini 2269c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2270c50d8ae3SPaolo Bonzini u64 spte) 2271c50d8ae3SPaolo Bonzini { 22723e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2273c50d8ae3SPaolo Bonzini iterator->level = 0; 2274c50d8ae3SPaolo Bonzini return; 2275c50d8ae3SPaolo Bonzini } 2276c50d8ae3SPaolo Bonzini 22772ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2278c50d8ae3SPaolo Bonzini --iterator->level; 2279c50d8ae3SPaolo Bonzini } 2280c50d8ae3SPaolo Bonzini 2281c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2282c50d8ae3SPaolo Bonzini { 2283c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2284c50d8ae3SPaolo Bonzini } 2285c50d8ae3SPaolo Bonzini 22860cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 22870cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 2288*03787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2289c50d8ae3SPaolo Bonzini { 2290c50d8ae3SPaolo Bonzini u64 spte; 2291c50d8ae3SPaolo Bonzini 2292c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2293c50d8ae3SPaolo Bonzini 22940cd8dc73SPaolo Bonzini /* 22950cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 2296*03787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 2297*03787394SPaolo Bonzini * installing sp. 22980cd8dc73SPaolo Bonzini */ 22990cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 2300*03787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 23010cd8dc73SPaolo Bonzini 2302cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2303c50d8ae3SPaolo Bonzini 2304c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2305c50d8ae3SPaolo Bonzini 23062ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2307c50d8ae3SPaolo Bonzini 2308c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2309c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2310c50d8ae3SPaolo Bonzini } 2311c50d8ae3SPaolo Bonzini 23122ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 23132ff9039aSDavid Matlack struct kvm_mmu_page *sp) 23142ff9039aSDavid Matlack { 2315*03787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 23162ff9039aSDavid Matlack } 23172ff9039aSDavid Matlack 2318c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2319c50d8ae3SPaolo Bonzini unsigned direct_access) 2320c50d8ae3SPaolo Bonzini { 2321c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2322c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2323c50d8ae3SPaolo Bonzini 2324c50d8ae3SPaolo Bonzini /* 2325c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2326c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2327c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2328c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2329c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2330c50d8ae3SPaolo Bonzini */ 23312ca3129eSSean Christopherson child = to_shadow_page(*sptep & SPTE_BASE_ADDR_MASK); 2332c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2333c50d8ae3SPaolo Bonzini return; 2334c50d8ae3SPaolo Bonzini 2335c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2336c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2337c50d8ae3SPaolo Bonzini } 2338c50d8ae3SPaolo Bonzini } 2339c50d8ae3SPaolo Bonzini 23402de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 23412de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 23422de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2343c50d8ae3SPaolo Bonzini { 2344c50d8ae3SPaolo Bonzini u64 pte; 2345c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2346c50d8ae3SPaolo Bonzini 2347c50d8ae3SPaolo Bonzini pte = *spte; 2348c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2349c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2350c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2351c50d8ae3SPaolo Bonzini } else { 23522ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2353c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 23542de4085cSBen Gardon 23552de4085cSBen Gardon /* 23562de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 23572de4085cSBen Gardon * unlikely to be used again in the near future. This 23582de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 23592de4085cSBen Gardon */ 23602de4085cSBen Gardon if (tdp_enabled && invalid_list && 23612de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 23622de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 23632de4085cSBen Gardon invalid_list); 2364c50d8ae3SPaolo Bonzini } 2365ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2366c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2367ace569e0SSean Christopherson } 23682de4085cSBen Gardon return 0; 2369c50d8ae3SPaolo Bonzini } 2370c50d8ae3SPaolo Bonzini 23712de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 23722de4085cSBen Gardon struct kvm_mmu_page *sp, 23732de4085cSBen Gardon struct list_head *invalid_list) 2374c50d8ae3SPaolo Bonzini { 23752de4085cSBen Gardon int zapped = 0; 2376c50d8ae3SPaolo Bonzini unsigned i; 2377c50d8ae3SPaolo Bonzini 23782ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 23792de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 23802de4085cSBen Gardon 23812de4085cSBen Gardon return zapped; 2382c50d8ae3SPaolo Bonzini } 2383c50d8ae3SPaolo Bonzini 238461827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2385c50d8ae3SPaolo Bonzini { 2386c50d8ae3SPaolo Bonzini u64 *sptep; 2387c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2388c50d8ae3SPaolo Bonzini 2389c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2390c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2391c50d8ae3SPaolo Bonzini } 2392c50d8ae3SPaolo Bonzini 2393c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2394c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2395c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2396c50d8ae3SPaolo Bonzini { 2397c50d8ae3SPaolo Bonzini int i, zapped = 0; 2398c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2399c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2400c50d8ae3SPaolo Bonzini 24013bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2402c50d8ae3SPaolo Bonzini return 0; 2403c50d8ae3SPaolo Bonzini 2404c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2405c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2406c50d8ae3SPaolo Bonzini 2407c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2408c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2409c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2410c50d8ae3SPaolo Bonzini zapped++; 2411c50d8ae3SPaolo Bonzini } 2412c50d8ae3SPaolo Bonzini } 2413c50d8ae3SPaolo Bonzini 2414c50d8ae3SPaolo Bonzini return zapped; 2415c50d8ae3SPaolo Bonzini } 2416c50d8ae3SPaolo Bonzini 2417c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2418c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2419c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2420c50d8ae3SPaolo Bonzini int *nr_zapped) 2421c50d8ae3SPaolo Bonzini { 2422527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2423c50d8ae3SPaolo Bonzini 2424c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2425c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2426c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 24272de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 242861827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2429c50d8ae3SPaolo Bonzini 2430c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2431c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2432c50d8ae3SPaolo Bonzini 2433767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2434c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2435c50d8ae3SPaolo Bonzini 2436c50d8ae3SPaolo Bonzini if (sp->unsync) 2437c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2438c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2439c50d8ae3SPaolo Bonzini /* Count self */ 2440c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2441f95eec9bSSean Christopherson 2442f95eec9bSSean Christopherson /* 2443f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2444f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2445f95eec9bSSean Christopherson * !sp->root_count. 2446f95eec9bSSean Christopherson */ 2447f95eec9bSSean Christopherson if (sp->role.invalid) 2448f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2449f95eec9bSSean Christopherson else 2450c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 2451c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(kvm, -1); 2452c50d8ae3SPaolo Bonzini } else { 2453f95eec9bSSean Christopherson /* 2454f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2455f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2456f95eec9bSSean Christopherson */ 2457f95eec9bSSean Christopherson list_del(&sp->link); 2458c50d8ae3SPaolo Bonzini 2459c50d8ae3SPaolo Bonzini /* 2460c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2461c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2462c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2463c50d8ae3SPaolo Bonzini */ 2464527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2465c50d8ae3SPaolo Bonzini } 2466c50d8ae3SPaolo Bonzini 2467c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2468c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2469c50d8ae3SPaolo Bonzini 2470c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2471527d5cd7SSean Christopherson 2472527d5cd7SSean Christopherson /* 2473527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2474527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2475527d5cd7SSean Christopherson */ 2476527d5cd7SSean Christopherson if (zapped_root) 2477527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2478c50d8ae3SPaolo Bonzini return list_unstable; 2479c50d8ae3SPaolo Bonzini } 2480c50d8ae3SPaolo Bonzini 2481c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2482c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2483c50d8ae3SPaolo Bonzini { 2484c50d8ae3SPaolo Bonzini int nr_zapped; 2485c50d8ae3SPaolo Bonzini 2486c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2487c50d8ae3SPaolo Bonzini return nr_zapped; 2488c50d8ae3SPaolo Bonzini } 2489c50d8ae3SPaolo Bonzini 2490c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2491c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2492c50d8ae3SPaolo Bonzini { 2493c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2494c50d8ae3SPaolo Bonzini 2495c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2496c50d8ae3SPaolo Bonzini return; 2497c50d8ae3SPaolo Bonzini 2498c50d8ae3SPaolo Bonzini /* 2499c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2500c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2501c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2502c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2503c50d8ae3SPaolo Bonzini * 2504c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2505c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2506c50d8ae3SPaolo Bonzini */ 2507c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2508c50d8ae3SPaolo Bonzini 2509c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2510c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 251187654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2512c50d8ae3SPaolo Bonzini } 2513c50d8ae3SPaolo Bonzini } 2514c50d8ae3SPaolo Bonzini 25156b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 25166b82ef2cSSean Christopherson unsigned long nr_to_zap) 2517c50d8ae3SPaolo Bonzini { 25186b82ef2cSSean Christopherson unsigned long total_zapped = 0; 25196b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2520ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 25216b82ef2cSSean Christopherson bool unstable; 25226b82ef2cSSean Christopherson int nr_zapped; 2523c50d8ae3SPaolo Bonzini 2524c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2525ba7888ddSSean Christopherson return 0; 2526c50d8ae3SPaolo Bonzini 25276b82ef2cSSean Christopherson restart: 25288fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 25296b82ef2cSSean Christopherson /* 25306b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 25316b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 25326b82ef2cSSean Christopherson */ 25336b82ef2cSSean Christopherson if (sp->root_count) 25346b82ef2cSSean Christopherson continue; 25356b82ef2cSSean Christopherson 25366b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 25376b82ef2cSSean Christopherson &nr_zapped); 25386b82ef2cSSean Christopherson total_zapped += nr_zapped; 25396b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2540ba7888ddSSean Christopherson break; 2541ba7888ddSSean Christopherson 25426b82ef2cSSean Christopherson if (unstable) 25436b82ef2cSSean Christopherson goto restart; 2544ba7888ddSSean Christopherson } 25456b82ef2cSSean Christopherson 25466b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 25476b82ef2cSSean Christopherson 25486b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 25496b82ef2cSSean Christopherson return total_zapped; 25506b82ef2cSSean Christopherson } 25516b82ef2cSSean Christopherson 2552afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2553afe8d7e6SSean Christopherson { 2554afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2555afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2556afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2557afe8d7e6SSean Christopherson 2558afe8d7e6SSean Christopherson return 0; 2559c50d8ae3SPaolo Bonzini } 2560c50d8ae3SPaolo Bonzini 2561ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2562ba7888ddSSean Christopherson { 25636b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2564ba7888ddSSean Christopherson 25656b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2566ba7888ddSSean Christopherson return 0; 2567ba7888ddSSean Christopherson 25686b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2569ba7888ddSSean Christopherson 25706e6ec584SSean Christopherson /* 25716e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 25726e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 25736e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 25746e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2575c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 25766e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 25776e6ec584SSean Christopherson * page fault paths. 25786e6ec584SSean Christopherson */ 2579ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2580ba7888ddSSean Christopherson return -ENOSPC; 2581ba7888ddSSean Christopherson return 0; 2582ba7888ddSSean Christopherson } 2583ba7888ddSSean Christopherson 2584c50d8ae3SPaolo Bonzini /* 2585c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2586c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2587c50d8ae3SPaolo Bonzini */ 2588c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2589c50d8ae3SPaolo Bonzini { 2590531810caSBen Gardon write_lock(&kvm->mmu_lock); 2591c50d8ae3SPaolo Bonzini 2592c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 25936b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 25946b82ef2cSSean Christopherson goal_nr_mmu_pages); 2595c50d8ae3SPaolo Bonzini 2596c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2597c50d8ae3SPaolo Bonzini } 2598c50d8ae3SPaolo Bonzini 2599c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2600c50d8ae3SPaolo Bonzini 2601531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2602c50d8ae3SPaolo Bonzini } 2603c50d8ae3SPaolo Bonzini 2604c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2605c50d8ae3SPaolo Bonzini { 2606c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2607c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2608c50d8ae3SPaolo Bonzini int r; 2609c50d8ae3SPaolo Bonzini 2610c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2611c50d8ae3SPaolo Bonzini r = 0; 2612531810caSBen Gardon write_lock(&kvm->mmu_lock); 2613767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2614c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2615c50d8ae3SPaolo Bonzini sp->role.word); 2616c50d8ae3SPaolo Bonzini r = 1; 2617c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2618c50d8ae3SPaolo Bonzini } 2619c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2620531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2621c50d8ae3SPaolo Bonzini 2622c50d8ae3SPaolo Bonzini return r; 2623c50d8ae3SPaolo Bonzini } 262496ad91aeSSean Christopherson 262596ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 262696ad91aeSSean Christopherson { 262796ad91aeSSean Christopherson gpa_t gpa; 262896ad91aeSSean Christopherson int r; 262996ad91aeSSean Christopherson 2630347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 263196ad91aeSSean Christopherson return 0; 263296ad91aeSSean Christopherson 263396ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 263496ad91aeSSean Christopherson 263596ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 263696ad91aeSSean Christopherson 263796ad91aeSSean Christopherson return r; 263896ad91aeSSean Christopherson } 2639c50d8ae3SPaolo Bonzini 26404d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2641c50d8ae3SPaolo Bonzini { 2642c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 26434d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2644c50d8ae3SPaolo Bonzini sp->unsync = 1; 2645c50d8ae3SPaolo Bonzini 2646c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2647c50d8ae3SPaolo Bonzini } 2648c50d8ae3SPaolo Bonzini 26490337f585SSean Christopherson /* 26500337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 26510337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 26520337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 26530337f585SSean Christopherson * be write-protected. 26540337f585SSean Christopherson */ 26558283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 26562839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2657c50d8ae3SPaolo Bonzini { 2658c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2659ce25681dSSean Christopherson bool locked = false; 2660c50d8ae3SPaolo Bonzini 26610337f585SSean Christopherson /* 26620337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 26630337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 26640337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 26650337f585SSean Christopherson */ 26664d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 26670337f585SSean Christopherson return -EPERM; 2668c50d8ae3SPaolo Bonzini 26690337f585SSean Christopherson /* 26700337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 26710337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 26720337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 26730337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 26740337f585SSean Christopherson */ 2675767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2676c50d8ae3SPaolo Bonzini if (!can_unsync) 26770337f585SSean Christopherson return -EPERM; 2678c50d8ae3SPaolo Bonzini 2679c50d8ae3SPaolo Bonzini if (sp->unsync) 2680c50d8ae3SPaolo Bonzini continue; 2681c50d8ae3SPaolo Bonzini 26822839180cSPaolo Bonzini if (prefetch) 2683f1c4a88cSLai Jiangshan return -EEXIST; 2684f1c4a88cSLai Jiangshan 2685ce25681dSSean Christopherson /* 2686ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2687ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2688ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2689ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2690ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2691ce25681dSSean Christopherson */ 2692ce25681dSSean Christopherson if (!locked) { 2693ce25681dSSean Christopherson locked = true; 26944d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2695ce25681dSSean Christopherson 2696ce25681dSSean Christopherson /* 2697ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2698ce25681dSSean Christopherson * may have since marked the page unsync. A false 2699ce25681dSSean Christopherson * positive on the unprotected check above is not 2700ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2701ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2702ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2703ce25681dSSean Christopherson */ 2704ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2705ce25681dSSean Christopherson continue; 2706ce25681dSSean Christopherson } 2707ce25681dSSean Christopherson 27083bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 27094d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2710c50d8ae3SPaolo Bonzini } 2711ce25681dSSean Christopherson if (locked) 27124d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2713c50d8ae3SPaolo Bonzini 2714c50d8ae3SPaolo Bonzini /* 2715c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2716c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2717c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2718c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2719c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2720c50d8ae3SPaolo Bonzini * following could happen: 2721c50d8ae3SPaolo Bonzini * 2722c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2723c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2724c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2725c50d8ae3SPaolo Bonzini * to be writable 2726c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2727c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2728c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2729c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2730c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2731c50d8ae3SPaolo Bonzini * fault. 2732c50d8ae3SPaolo Bonzini * 2733c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2734c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2735c50d8ae3SPaolo Bonzini * 27360337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 27370337f585SSean Christopherson * false and skips the page. 2738c50d8ae3SPaolo Bonzini * 2739c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2740c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2741c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2742c50d8ae3SPaolo Bonzini * gets used. 2743c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2744c50d8ae3SPaolo Bonzini * as unsync 2745c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2746c50d8ae3SPaolo Bonzini * 2747c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2748264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2749264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2750c50d8ae3SPaolo Bonzini */ 2751c50d8ae3SPaolo Bonzini smp_wmb(); 2752c50d8ae3SPaolo Bonzini 27530337f585SSean Christopherson return 0; 2754c50d8ae3SPaolo Bonzini } 2755c50d8ae3SPaolo Bonzini 27568a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 27578a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2758a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2759799a4190SBen Gardon { 2760d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2761eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2762c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2763c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2764c50d8ae3SPaolo Bonzini bool flush = false; 2765ad67e480SPaolo Bonzini bool wrprot; 2766d786c778SPaolo Bonzini u64 spte; 2767c50d8ae3SPaolo Bonzini 2768a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2769a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 27702839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2771a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2772c50d8ae3SPaolo Bonzini 2773c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2774c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2775c50d8ae3SPaolo Bonzini 2776a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 27771075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2778a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2779a54aa15cSSean Christopherson return RET_PF_EMULATE; 2780a54aa15cSSean Christopherson } 2781a54aa15cSSean Christopherson 2782c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2783c50d8ae3SPaolo Bonzini /* 2784c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2785c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2786c50d8ae3SPaolo Bonzini */ 27873bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2788c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2789c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2790c50d8ae3SPaolo Bonzini 27912ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2792c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2793c50d8ae3SPaolo Bonzini flush = true; 2794c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2795c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2796c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2797c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2798c50d8ae3SPaolo Bonzini flush = true; 2799c50d8ae3SPaolo Bonzini } else 2800c50d8ae3SPaolo Bonzini was_rmapped = 1; 2801c50d8ae3SPaolo Bonzini } 2802c50d8ae3SPaolo Bonzini 28032839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 28047158bee4SPaolo Bonzini true, host_writable, &spte); 2805d786c778SPaolo Bonzini 2806d786c778SPaolo Bonzini if (*sptep == spte) { 2807d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2808d786c778SPaolo Bonzini } else { 2809d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 28105959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2811c50d8ae3SPaolo Bonzini } 2812c50d8ae3SPaolo Bonzini 2813ad67e480SPaolo Bonzini if (wrprot) { 2814c50d8ae3SPaolo Bonzini if (write_fault) 2815c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2816c50d8ae3SPaolo Bonzini } 2817c50d8ae3SPaolo Bonzini 2818d786c778SPaolo Bonzini if (flush) 2819c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2820c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2821c50d8ae3SPaolo Bonzini 2822c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2823c50d8ae3SPaolo Bonzini 2824c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2825d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 28266a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 28276a97575dSDavid Matlack } else { 28286a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 28296a97575dSDavid Matlack kvm_mmu_page_set_access(sp, sptep - sp->spt, pte_access); 2830c50d8ae3SPaolo Bonzini } 2831c50d8ae3SPaolo Bonzini 2832c50d8ae3SPaolo Bonzini return ret; 2833c50d8ae3SPaolo Bonzini } 2834c50d8ae3SPaolo Bonzini 2835c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2836c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2837c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2838c50d8ae3SPaolo Bonzini { 2839c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2840c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 28410a2b64c5SBen Gardon unsigned int access = sp->role.access; 2842c50d8ae3SPaolo Bonzini int i, ret; 2843c50d8ae3SPaolo Bonzini gfn_t gfn; 2844c50d8ae3SPaolo Bonzini 2845c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt); 2846c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2847c50d8ae3SPaolo Bonzini if (!slot) 2848c50d8ae3SPaolo Bonzini return -1; 2849c50d8ae3SPaolo Bonzini 2850c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2851c50d8ae3SPaolo Bonzini if (ret <= 0) 2852c50d8ae3SPaolo Bonzini return -1; 2853c50d8ae3SPaolo Bonzini 2854c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 28558a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2856a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2857c50d8ae3SPaolo Bonzini put_page(pages[i]); 2858c50d8ae3SPaolo Bonzini } 2859c50d8ae3SPaolo Bonzini 2860c50d8ae3SPaolo Bonzini return 0; 2861c50d8ae3SPaolo Bonzini } 2862c50d8ae3SPaolo Bonzini 2863c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2864c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2865c50d8ae3SPaolo Bonzini { 2866c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2867c50d8ae3SPaolo Bonzini int i; 2868c50d8ae3SPaolo Bonzini 2869c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2870c50d8ae3SPaolo Bonzini 2871c50d8ae3SPaolo Bonzini i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); 2872c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2873c50d8ae3SPaolo Bonzini 2874c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2875c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2876c50d8ae3SPaolo Bonzini if (!start) 2877c50d8ae3SPaolo Bonzini continue; 2878c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2879c6cecc4bSSean Christopherson return; 2880c50d8ae3SPaolo Bonzini start = NULL; 2881c50d8ae3SPaolo Bonzini } else if (!start) 2882c50d8ae3SPaolo Bonzini start = spte; 2883c50d8ae3SPaolo Bonzini } 2884c6cecc4bSSean Christopherson if (start) 2885c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2886c50d8ae3SPaolo Bonzini } 2887c50d8ae3SPaolo Bonzini 2888c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2889c50d8ae3SPaolo Bonzini { 2890c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2891c50d8ae3SPaolo Bonzini 289257354682SSean Christopherson sp = sptep_to_sp(sptep); 2893c50d8ae3SPaolo Bonzini 2894c50d8ae3SPaolo Bonzini /* 2895c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2896c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2897c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2898c50d8ae3SPaolo Bonzini */ 2899c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2900c50d8ae3SPaolo Bonzini return; 2901c50d8ae3SPaolo Bonzini 29023bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2903c50d8ae3SPaolo Bonzini return; 2904c50d8ae3SPaolo Bonzini 29054a42d848SDavid Stevens /* 29064a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 29074a42d848SDavid Stevens * accidentally prefetching those addresses. 29084a42d848SDavid Stevens */ 29094a42d848SDavid Stevens if (unlikely(vcpu->kvm->mmu_notifier_count)) 29104a42d848SDavid Stevens return; 29114a42d848SDavid Stevens 2912c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2913c50d8ae3SPaolo Bonzini } 2914c50d8ae3SPaolo Bonzini 29151b6d9d9eSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, 29168ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2917db543216SSean Christopherson { 2918284dc493SSean Christopherson int level = PG_LEVEL_4K; 29195d49f08cSSean Christopherson struct page *page; 2920db543216SSean Christopherson unsigned long hva; 292144187235SMingwei Zhang unsigned long flags; 292244187235SMingwei Zhang pgd_t pgd; 292344187235SMingwei Zhang p4d_t p4d; 292444187235SMingwei Zhang pud_t pud; 292544187235SMingwei Zhang pmd_t pmd; 2926db543216SSean Christopherson 29275d49f08cSSean Christopherson /* 29285d49f08cSSean Christopherson * Note, @slot must be non-NULL, i.e. the caller is responsible for 29295d49f08cSSean Christopherson * ensuring @pfn isn't garbage and is backed by a memslot. 29305d49f08cSSean Christopherson */ 29315d49f08cSSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 29325d49f08cSSean Christopherson if (!page) 29335d49f08cSSean Christopherson return PG_LEVEL_4K; 29345d49f08cSSean Christopherson 2935284dc493SSean Christopherson if (!PageCompound(page) && !kvm_is_zone_device_page(page)) 29363bae0459SSean Christopherson return PG_LEVEL_4K; 2937db543216SSean Christopherson 2938293e306eSSean Christopherson /* 2939293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2940293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2941293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2942293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2943293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2944293e306eSSean Christopherson * read-only memslot. 2945293e306eSSean Christopherson */ 2946db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2947db543216SSean Christopherson 294844187235SMingwei Zhang /* 294944187235SMingwei Zhang * Lookup the mapping level in the current mm. The information 295044187235SMingwei Zhang * may become stale soon, but it is safe to use as long as 295144187235SMingwei Zhang * 1) mmu_notifier_retry was checked after taking mmu_lock, and 295244187235SMingwei Zhang * 2) mmu_lock is taken now. 295344187235SMingwei Zhang * 295444187235SMingwei Zhang * We still need to disable IRQs to prevent concurrent tear down 295544187235SMingwei Zhang * of page tables. 295644187235SMingwei Zhang */ 295744187235SMingwei Zhang local_irq_save(flags); 2958db543216SSean Christopherson 295944187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 296044187235SMingwei Zhang if (pgd_none(pgd)) 296144187235SMingwei Zhang goto out; 296244187235SMingwei Zhang 296344187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 296444187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 296544187235SMingwei Zhang goto out; 296644187235SMingwei Zhang 296744187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 296844187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 296944187235SMingwei Zhang goto out; 297044187235SMingwei Zhang 297144187235SMingwei Zhang if (pud_large(pud)) { 297244187235SMingwei Zhang level = PG_LEVEL_1G; 297344187235SMingwei Zhang goto out; 297444187235SMingwei Zhang } 297544187235SMingwei Zhang 297644187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 297744187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 297844187235SMingwei Zhang goto out; 297944187235SMingwei Zhang 298044187235SMingwei Zhang if (pmd_large(pmd)) 298144187235SMingwei Zhang level = PG_LEVEL_2M; 298244187235SMingwei Zhang 298344187235SMingwei Zhang out: 298444187235SMingwei Zhang local_irq_restore(flags); 2985db543216SSean Christopherson return level; 2986db543216SSean Christopherson } 2987db543216SSean Christopherson 29888ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 29898ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 29908ca6f063SBen Gardon kvm_pfn_t pfn, int max_level) 29911b6d9d9eSSean Christopherson { 29921b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 2993ec607a56SPaolo Bonzini int host_level; 29941b6d9d9eSSean Christopherson 29951b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 29961b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 29971b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 29981b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 29991b6d9d9eSSean Christopherson break; 30001b6d9d9eSSean Christopherson } 30011b6d9d9eSSean Christopherson 30021b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 30031b6d9d9eSSean Christopherson return PG_LEVEL_4K; 30041b6d9d9eSSean Christopherson 3005ec607a56SPaolo Bonzini host_level = host_pfn_mapping_level(kvm, gfn, pfn, slot); 3006ec607a56SPaolo Bonzini return min(host_level, max_level); 30071b6d9d9eSSean Christopherson } 30081b6d9d9eSSean Christopherson 300973a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 30100885904dSSean Christopherson { 3011e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 301217eff019SSean Christopherson kvm_pfn_t mask; 30130885904dSSean Christopherson 301473a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 30153cf06612SSean Christopherson 301673a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 301773a3c659SPaolo Bonzini return; 301817eff019SSean Christopherson 30195d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 302073a3c659SPaolo Bonzini return; 302117eff019SSean Christopherson 3022e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 302373a3c659SPaolo Bonzini return; 3024293e306eSSean Christopherson 30253cf06612SSean Christopherson /* 30263cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 30273cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 30283cf06612SSean Christopherson */ 302973a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 303073a3c659SPaolo Bonzini fault->gfn, fault->pfn, 303173a3c659SPaolo Bonzini fault->max_level); 303273a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 303373a3c659SPaolo Bonzini return; 30344cd071d1SSean Christopherson 30350885904dSSean Christopherson /* 30364cd071d1SSean Christopherson * mmu_notifier_retry() was successful and mmu_lock is held, so 30374cd071d1SSean Christopherson * the pmd can't be split from under us. 30380885904dSSean Christopherson */ 303973a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 304073a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 304173a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 304273a3c659SPaolo Bonzini fault->pfn &= ~mask; 30430885904dSSean Christopherson } 30440885904dSSean Christopherson 3045536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3046c50d8ae3SPaolo Bonzini { 3047536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3048536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3049c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 3050c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 3051c50d8ae3SPaolo Bonzini /* 3052c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 3053c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 3054c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 3055c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 3056c50d8ae3SPaolo Bonzini * the address. 3057c50d8ae3SPaolo Bonzini */ 3058536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3059536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3060536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3061536f0e6aSPaolo Bonzini fault->goal_level--; 3062c50d8ae3SPaolo Bonzini } 3063c50d8ae3SPaolo Bonzini } 3064c50d8ae3SPaolo Bonzini 306543b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3066c50d8ae3SPaolo Bonzini { 3067c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3068c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 306973a3c659SPaolo Bonzini int ret; 307043b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3071c50d8ae3SPaolo Bonzini 307273a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 30734cd071d1SSean Christopherson 3074f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 307543b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3076c50d8ae3SPaolo Bonzini /* 3077c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3078c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3079c50d8ae3SPaolo Bonzini */ 308073a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3081536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3082c50d8ae3SPaolo Bonzini 308343b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 308473a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3085c50d8ae3SPaolo Bonzini break; 3086c50d8ae3SPaolo Bonzini 30872e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 30880cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 30890cd8dc73SPaolo Bonzini continue; 3090c50d8ae3SPaolo Bonzini 3091c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 309273a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 309373a3c659SPaolo Bonzini fault->req_level >= it.level) 3094c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 3095c50d8ae3SPaolo Bonzini } 3096c50d8ae3SPaolo Bonzini 3097b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3098b1a429fbSSean Christopherson return -EFAULT; 3099b1a429fbSSean Christopherson 31008a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3101a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 310212703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 310312703759SSean Christopherson return ret; 310412703759SSean Christopherson 3105c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3106c50d8ae3SPaolo Bonzini return ret; 3107c50d8ae3SPaolo Bonzini } 3108c50d8ae3SPaolo Bonzini 3109c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 3110c50d8ae3SPaolo Bonzini { 3111c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 3112c50d8ae3SPaolo Bonzini } 3113c50d8ae3SPaolo Bonzini 3114c50d8ae3SPaolo Bonzini static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 3115c50d8ae3SPaolo Bonzini { 3116c50d8ae3SPaolo Bonzini /* 3117c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3118c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3119c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3120c50d8ae3SPaolo Bonzini */ 3121c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3122c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3123c50d8ae3SPaolo Bonzini 3124c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3125c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3126c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3127c50d8ae3SPaolo Bonzini } 3128c50d8ae3SPaolo Bonzini 3129c50d8ae3SPaolo Bonzini return -EFAULT; 3130c50d8ae3SPaolo Bonzini } 3131c50d8ae3SPaolo Bonzini 31325276c616SSean Christopherson static int handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 31335276c616SSean Christopherson unsigned int access) 3134c50d8ae3SPaolo Bonzini { 3135c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 31365276c616SSean Christopherson if (unlikely(is_error_pfn(fault->pfn))) 31375276c616SSean Christopherson return kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); 3138c50d8ae3SPaolo Bonzini 3139e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 31403a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 31413a13f4feSPaolo Bonzini 31423a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3143c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 314430ab5901SSean Christopherson /* 314530ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 314630ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 314786931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 314886931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 314986931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 315086931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 315186931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 315286931ff7SSean Christopherson * the hardware's). 315330ab5901SSean Christopherson */ 31548b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 31555276c616SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) 31565276c616SSean Christopherson return RET_PF_EMULATE; 315730ab5901SSean Christopherson } 3158c50d8ae3SPaolo Bonzini 31595276c616SSean Christopherson return RET_PF_CONTINUE; 3160c50d8ae3SPaolo Bonzini } 3161c50d8ae3SPaolo Bonzini 31623c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3163c50d8ae3SPaolo Bonzini { 3164c50d8ae3SPaolo Bonzini /* 31655c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 31665c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 31675c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 31685c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3169c50d8ae3SPaolo Bonzini */ 31703c8ad5a6SPaolo Bonzini if (fault->rsvd) 3171c50d8ae3SPaolo Bonzini return false; 3172c50d8ae3SPaolo Bonzini 3173c50d8ae3SPaolo Bonzini /* 3174c50d8ae3SPaolo Bonzini * #PF can be fast if: 3175c50d8ae3SPaolo Bonzini * 317654275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 317754275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 317854275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 317954275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 318054275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 318154275f74SSean Christopherson * mechanism only supports direct MMUs. 318254275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 318354275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 318454275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 318554275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 318654275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3187c50d8ae3SPaolo Bonzini */ 31885c64aba5SSean Christopherson if (!fault->present) 31895c64aba5SSean Christopherson return !kvm_ad_enabled(); 31905c64aba5SSean Christopherson 31915c64aba5SSean Christopherson /* 31925c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 31935c64aba5SSean Christopherson * the "exec" flag. 31945c64aba5SSean Christopherson */ 31955c64aba5SSean Christopherson return fault->write; 3196c50d8ae3SPaolo Bonzini } 3197c50d8ae3SPaolo Bonzini 3198c50d8ae3SPaolo Bonzini /* 3199c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3200c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3201c50d8ae3SPaolo Bonzini */ 3202c50d8ae3SPaolo Bonzini static bool 3203e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3204c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3205c50d8ae3SPaolo Bonzini { 3206c50d8ae3SPaolo Bonzini /* 3207c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3208c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3209c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3210c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3211c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3212c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3213c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3214c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3215c50d8ae3SPaolo Bonzini * 3216c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3217c50d8ae3SPaolo Bonzini */ 32182db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3219c50d8ae3SPaolo Bonzini return false; 3220c50d8ae3SPaolo Bonzini 3221e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3222e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3223c50d8ae3SPaolo Bonzini 3224c50d8ae3SPaolo Bonzini return true; 3225c50d8ae3SPaolo Bonzini } 3226c50d8ae3SPaolo Bonzini 32273c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3228c50d8ae3SPaolo Bonzini { 32293c8ad5a6SPaolo Bonzini if (fault->exec) 3230c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3231c50d8ae3SPaolo Bonzini 32323c8ad5a6SPaolo Bonzini if (fault->write) 3233c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3234c50d8ae3SPaolo Bonzini 3235c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3236c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3237c50d8ae3SPaolo Bonzini } 3238c50d8ae3SPaolo Bonzini 3239c50d8ae3SPaolo Bonzini /* 32406e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 32416e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 32426e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 32436e8eb206SDavid Matlack * 32446e8eb206SDavid Matlack * Contract: 32456e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 32466e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 32476e8eb206SDavid Matlack */ 32486e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 32496e8eb206SDavid Matlack { 32506e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 32516e8eb206SDavid Matlack u64 old_spte; 32526e8eb206SDavid Matlack u64 *sptep = NULL; 32536e8eb206SDavid Matlack 32546e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 32556e8eb206SDavid Matlack sptep = iterator.sptep; 32566e8eb206SDavid Matlack *spte = old_spte; 32576e8eb206SDavid Matlack } 32586e8eb206SDavid Matlack 32596e8eb206SDavid Matlack return sptep; 32606e8eb206SDavid Matlack } 32616e8eb206SDavid Matlack 32626e8eb206SDavid Matlack /* 3263c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3264c50d8ae3SPaolo Bonzini */ 32653c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3266c50d8ae3SPaolo Bonzini { 3267c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3268c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3269c50d8ae3SPaolo Bonzini u64 spte = 0ull; 32706e8eb206SDavid Matlack u64 *sptep = NULL; 3271c50d8ae3SPaolo Bonzini uint retry_count = 0; 3272c50d8ae3SPaolo Bonzini 32733c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3274c4371c2aSSean Christopherson return ret; 3275c50d8ae3SPaolo Bonzini 3276c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3277c50d8ae3SPaolo Bonzini 3278c50d8ae3SPaolo Bonzini do { 3279c50d8ae3SPaolo Bonzini u64 new_spte; 3280c50d8ae3SPaolo Bonzini 32816e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 32823c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 32836e8eb206SDavid Matlack else 32843c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3285c50d8ae3SPaolo Bonzini 3286ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3287ec89e643SSean Christopherson break; 3288ec89e643SSean Christopherson 32896e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3290c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3291c50d8ae3SPaolo Bonzini break; 3292c50d8ae3SPaolo Bonzini 3293c50d8ae3SPaolo Bonzini /* 3294c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3295c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3296c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3297c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3298c50d8ae3SPaolo Bonzini * current CPU took the fault. 3299c50d8ae3SPaolo Bonzini * 3300c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3301c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3302c50d8ae3SPaolo Bonzini */ 33033c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3304c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3305c50d8ae3SPaolo Bonzini break; 3306c50d8ae3SPaolo Bonzini } 3307c50d8ae3SPaolo Bonzini 3308c50d8ae3SPaolo Bonzini new_spte = spte; 3309c50d8ae3SPaolo Bonzini 331054275f74SSean Christopherson /* 331154275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 331254275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 331354275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 331454275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 331554275f74SSean Christopherson */ 331654275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3317c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3318c50d8ae3SPaolo Bonzini 3319c50d8ae3SPaolo Bonzini /* 332054275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 332154275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 332254275f74SSean Christopherson * that were write-protected for dirty-logging or access 332354275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 332454275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 332554275f74SSean Christopherson * The is_access_allowed() check above handles the common case 332654275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 332754275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 332854275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3329c50d8ae3SPaolo Bonzini */ 3330706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3331c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3332c50d8ae3SPaolo Bonzini 3333c50d8ae3SPaolo Bonzini /* 333410c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 333510c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 333610c30de0SJunaid Shahid * first page into the dirty-bitmap in 3337c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3338c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3339c50d8ae3SPaolo Bonzini * 3340c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3341c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3342c50d8ae3SPaolo Bonzini */ 334310c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 334410c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3345c50d8ae3SPaolo Bonzini break; 3346c50d8ae3SPaolo Bonzini } 3347c50d8ae3SPaolo Bonzini 3348c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3349c50d8ae3SPaolo Bonzini if (new_spte == spte || 33503c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3351c50d8ae3SPaolo Bonzini break; 3352c50d8ae3SPaolo Bonzini 3353c50d8ae3SPaolo Bonzini /* 3354c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3355c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 33563ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3357c50d8ae3SPaolo Bonzini */ 3358e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3359c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3360c50d8ae3SPaolo Bonzini break; 3361c4371c2aSSean Christopherson } 3362c50d8ae3SPaolo Bonzini 3363c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3364c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3365c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3366c50d8ae3SPaolo Bonzini break; 3367c50d8ae3SPaolo Bonzini } 3368c50d8ae3SPaolo Bonzini 3369c50d8ae3SPaolo Bonzini } while (true); 3370c50d8ae3SPaolo Bonzini 3371f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3372c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3373c50d8ae3SPaolo Bonzini 33741075d41eSSean Christopherson if (ret != RET_PF_INVALID) 33751075d41eSSean Christopherson vcpu->stat.pf_fast++; 33761075d41eSSean Christopherson 3377c4371c2aSSean Christopherson return ret; 3378c50d8ae3SPaolo Bonzini } 3379c50d8ae3SPaolo Bonzini 3380c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3381c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3382c50d8ae3SPaolo Bonzini { 3383c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3384c50d8ae3SPaolo Bonzini 3385c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3386c50d8ae3SPaolo Bonzini return; 3387c50d8ae3SPaolo Bonzini 33882ca3129eSSean Christopherson sp = to_shadow_page(*root_hpa & SPTE_BASE_ADDR_MASK); 33899191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 33909191b8f0SPaolo Bonzini return; 339102c00b3aSBen Gardon 3392897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 33936103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 339476eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3395c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3396c50d8ae3SPaolo Bonzini 3397c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3398c50d8ae3SPaolo Bonzini } 3399c50d8ae3SPaolo Bonzini 3400c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 34010c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3402c50d8ae3SPaolo Bonzini ulong roots_to_free) 3403c50d8ae3SPaolo Bonzini { 3404c50d8ae3SPaolo Bonzini int i; 3405c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3406594bef79SPaolo Bonzini bool free_active_root; 3407c50d8ae3SPaolo Bonzini 3408c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3409c50d8ae3SPaolo Bonzini 3410c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3411594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3412594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3413594bef79SPaolo Bonzini 3414594bef79SPaolo Bonzini if (!free_active_root) { 3415c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3416c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3417c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3418c50d8ae3SPaolo Bonzini break; 3419c50d8ae3SPaolo Bonzini 3420c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3421c50d8ae3SPaolo Bonzini return; 3422c50d8ae3SPaolo Bonzini } 3423c50d8ae3SPaolo Bonzini 3424531810caSBen Gardon write_lock(&kvm->mmu_lock); 3425c50d8ae3SPaolo Bonzini 3426c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3427c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 34284d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3429c50d8ae3SPaolo Bonzini &invalid_list); 3430c50d8ae3SPaolo Bonzini 3431c50d8ae3SPaolo Bonzini if (free_active_root) { 3432594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3433b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 343404d45551SSean Christopherson } else if (mmu->pae_root) { 3435c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3436c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3437c834e5e4SSean Christopherson continue; 3438c834e5e4SSean Christopherson 3439c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3440c50d8ae3SPaolo Bonzini &invalid_list); 3441c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3442c50d8ae3SPaolo Bonzini } 3443c50d8ae3SPaolo Bonzini } 3444b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3445b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3446c50d8ae3SPaolo Bonzini } 3447c50d8ae3SPaolo Bonzini 34484d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3449531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3450c50d8ae3SPaolo Bonzini } 3451c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3452c50d8ae3SPaolo Bonzini 34530c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 345425b62c62SSean Christopherson { 345525b62c62SSean Christopherson unsigned long roots_to_free = 0; 345625b62c62SSean Christopherson hpa_t root_hpa; 345725b62c62SSean Christopherson int i; 345825b62c62SSean Christopherson 345925b62c62SSean Christopherson /* 346025b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 346125b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 346225b62c62SSean Christopherson */ 34637a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 346425b62c62SSean Christopherson 346525b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 346625b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 346725b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 346825b62c62SSean Christopherson continue; 346925b62c62SSean Christopherson 347025b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 347125b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 347225b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 347325b62c62SSean Christopherson } 347425b62c62SSean Christopherson 34750c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 347625b62c62SSean Christopherson } 347725b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 347825b62c62SSean Christopherson 347925b62c62SSean Christopherson 3480c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3481c50d8ae3SPaolo Bonzini { 3482c50d8ae3SPaolo Bonzini int ret = 0; 3483c50d8ae3SPaolo Bonzini 3484995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3485c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3486c50d8ae3SPaolo Bonzini ret = 1; 3487c50d8ae3SPaolo Bonzini } 3488c50d8ae3SPaolo Bonzini 3489c50d8ae3SPaolo Bonzini return ret; 3490c50d8ae3SPaolo Bonzini } 3491c50d8ae3SPaolo Bonzini 34922e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 349386938ab6SDavid Matlack u8 level) 3494c50d8ae3SPaolo Bonzini { 34952e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3496c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 34978123f265SSean Christopherson 34982e65e842SDavid Matlack role.level = level; 34992e65e842SDavid Matlack role.quadrant = quadrant; 35002e65e842SDavid Matlack 35017f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 35027f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 35037f497775SDavid Matlack 350487654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 35058123f265SSean Christopherson ++sp->root_count; 35068123f265SSean Christopherson 35078123f265SSean Christopherson return __pa(sp->spt); 35088123f265SSean Christopherson } 35098123f265SSean Christopherson 35108123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 35118123f265SSean Christopherson { 3512b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3513a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 35148123f265SSean Christopherson hpa_t root; 3515c50d8ae3SPaolo Bonzini unsigned i; 35164a38162eSPaolo Bonzini int r; 35174a38162eSPaolo Bonzini 35184a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35194a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35204a38162eSPaolo Bonzini if (r < 0) 35214a38162eSPaolo Bonzini goto out_unlock; 3522c50d8ae3SPaolo Bonzini 3523897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 352402c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3525b9e5603cSPaolo Bonzini mmu->root.hpa = root; 352602c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 352786938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3528b9e5603cSPaolo Bonzini mmu->root.hpa = root; 35298123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 35304a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35314a38162eSPaolo Bonzini r = -EIO; 35324a38162eSPaolo Bonzini goto out_unlock; 35334a38162eSPaolo Bonzini } 353473ad1606SSean Christopherson 3535c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3536c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3537c50d8ae3SPaolo Bonzini 35387f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 35392e65e842SDavid Matlack PT32_ROOT_LEVEL); 354017e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3541d2263de1SYuan Yao shadow_me_value; 3542c50d8ae3SPaolo Bonzini } 3543b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 354473ad1606SSean Christopherson } else { 354573ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 35464a38162eSPaolo Bonzini r = -EIO; 35474a38162eSPaolo Bonzini goto out_unlock; 354873ad1606SSean Christopherson } 35493651c7fcSSean Christopherson 3550b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3551b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 35524a38162eSPaolo Bonzini out_unlock: 35534a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 35544a38162eSPaolo Bonzini return r; 3555c50d8ae3SPaolo Bonzini } 3556c50d8ae3SPaolo Bonzini 35571e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 35581e76a3ceSDavid Stevens { 35591e76a3ceSDavid Stevens struct kvm_memslots *slots; 35601e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3561a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 35621e76a3ceSDavid Stevens 35631e76a3ceSDavid Stevens /* 35641e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 35651e76a3ceSDavid Stevens * taking the lock. 35661e76a3ceSDavid Stevens */ 35671e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 35681e76a3ceSDavid Stevens return 0; 35691e76a3ceSDavid Stevens 35701e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 35711e76a3ceSDavid Stevens 35721e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 35731e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 35741e76a3ceSDavid Stevens goto out_unlock; 35751e76a3ceSDavid Stevens 35761e76a3ceSDavid Stevens /* 35771e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 35781e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 35791e76a3ceSDavid Stevens */ 35801e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 35811e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 35821e76a3ceSDavid Stevens goto out_success; 35831e76a3ceSDavid Stevens 35841e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 35851e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3586a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 35871e76a3ceSDavid Stevens /* 35881e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 35891e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 35901e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 35911e76a3ceSDavid Stevens * failure to avoid having to track which allocations 35921e76a3ceSDavid Stevens * were made now versus when the memslot was created. 35931e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 35941e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 35951e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 35961e76a3ceSDavid Stevens */ 35971e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 35981e76a3ceSDavid Stevens if (r) 35991e76a3ceSDavid Stevens goto out_unlock; 36001e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 36011e76a3ceSDavid Stevens if (r) 36021e76a3ceSDavid Stevens goto out_unlock; 36031e76a3ceSDavid Stevens } 36041e76a3ceSDavid Stevens } 36051e76a3ceSDavid Stevens 36061e76a3ceSDavid Stevens /* 36071e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 36081e76a3ceSDavid Stevens * all the related pointers are set. 36091e76a3ceSDavid Stevens */ 36101e76a3ceSDavid Stevens out_success: 36111e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 36121e76a3ceSDavid Stevens 36131e76a3ceSDavid Stevens out_unlock: 36141e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 36151e76a3ceSDavid Stevens return r; 36161e76a3ceSDavid Stevens } 36171e76a3ceSDavid Stevens 3618c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3619c50d8ae3SPaolo Bonzini { 3620b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 36216e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3622be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 36237f497775SDavid Matlack int quadrant, i, r; 36248123f265SSean Christopherson hpa_t root; 3625c50d8ae3SPaolo Bonzini 3626b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3627be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3628c50d8ae3SPaolo Bonzini 3629c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3630c50d8ae3SPaolo Bonzini return 1; 3631c50d8ae3SPaolo Bonzini 3632c50d8ae3SPaolo Bonzini /* 36334a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 36344a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 36354a38162eSPaolo Bonzini */ 36364d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 36376e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 36386e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 36396e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 36406e0918aeSSean Christopherson continue; 36416e0918aeSSean Christopherson 36426e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 36436e0918aeSSean Christopherson return 1; 36446e0918aeSSean Christopherson } 36456e0918aeSSean Christopherson } 36466e0918aeSSean Christopherson 36471e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3648d501f747SBen Gardon if (r) 3649d501f747SBen Gardon return r; 3650d501f747SBen Gardon 36514a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36524a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36534a38162eSPaolo Bonzini if (r < 0) 36544a38162eSPaolo Bonzini goto out_unlock; 36554a38162eSPaolo Bonzini 3656c50d8ae3SPaolo Bonzini /* 3657c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3658c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3659c50d8ae3SPaolo Bonzini */ 36604d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 36618123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 366286938ab6SDavid Matlack mmu->root_role.level); 3663b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3664be01e8e2SSean Christopherson goto set_root_pgd; 3665c50d8ae3SPaolo Bonzini } 3666c50d8ae3SPaolo Bonzini 36674a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 36684a38162eSPaolo Bonzini r = -EIO; 36694a38162eSPaolo Bonzini goto out_unlock; 36704a38162eSPaolo Bonzini } 367173ad1606SSean Christopherson 3672c50d8ae3SPaolo Bonzini /* 3673c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3674c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3675c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3676c50d8ae3SPaolo Bonzini */ 3677e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3678a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3679c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3680c50d8ae3SPaolo Bonzini 368103ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 36824a38162eSPaolo Bonzini r = -EIO; 36834a38162eSPaolo Bonzini goto out_unlock; 36844a38162eSPaolo Bonzini } 368503ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3686cb0f722aSWei Huang 3687a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3688cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3689cb0f722aSWei Huang r = -EIO; 3690cb0f722aSWei Huang goto out_unlock; 3691cb0f722aSWei Huang } 3692cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3693cb0f722aSWei Huang } 369404d45551SSean Christopherson } 369504d45551SSean Christopherson 3696c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3697c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 36986e6ec584SSean Christopherson 36994d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 37006e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3701c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3702c50d8ae3SPaolo Bonzini continue; 3703c50d8ae3SPaolo Bonzini } 37046e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3705c50d8ae3SPaolo Bonzini } 3706c50d8ae3SPaolo Bonzini 37077f497775SDavid Matlack /* 37087f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 37097f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 37107f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 37117f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 37127f497775SDavid Matlack */ 37137f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 37147f497775SDavid Matlack 37157f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3716b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3717c50d8ae3SPaolo Bonzini } 3718c50d8ae3SPaolo Bonzini 3719a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3720b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3721a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3722b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3723ba0a194fSSean Christopherson else 3724b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3725c50d8ae3SPaolo Bonzini 3726be01e8e2SSean Christopherson set_root_pgd: 3727b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 37284a38162eSPaolo Bonzini out_unlock: 37294a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3730c50d8ae3SPaolo Bonzini 3731c6c937d6SLike Xu return r; 3732c50d8ae3SPaolo Bonzini } 3733c50d8ae3SPaolo Bonzini 3734748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3735c50d8ae3SPaolo Bonzini { 3736748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3737a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3738cb0f722aSWei Huang u64 *pml5_root = NULL; 3739cb0f722aSWei Huang u64 *pml4_root = NULL; 3740cb0f722aSWei Huang u64 *pae_root; 3741748e52b9SSean Christopherson 3742748e52b9SSean Christopherson /* 3743748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3744748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3745748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3746748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3747748e52b9SSean Christopherson */ 3748347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3749347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3750a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3751748e52b9SSean Christopherson return 0; 3752748e52b9SSean Christopherson 3753a717a780SSean Christopherson /* 3754a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3755a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3756a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3757a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3758a717a780SSean Christopherson * prior MMU would also have required pml5. 3759a717a780SSean Christopherson */ 3760a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3761748e52b9SSean Christopherson return 0; 3762748e52b9SSean Christopherson 3763748e52b9SSean Christopherson /* 3764748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3765748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3766748e52b9SSean Christopherson */ 3767cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3768a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3769748e52b9SSean Christopherson return -EIO; 3770748e52b9SSean Christopherson 37714a98623dSSean Christopherson /* 37724a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 37734a98623dSSean Christopherson * doesn't need to be decrypted. 37744a98623dSSean Christopherson */ 3775748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3776748e52b9SSean Christopherson if (!pae_root) 3777748e52b9SSean Christopherson return -ENOMEM; 3778748e52b9SSean Christopherson 3779cb0f722aSWei Huang #ifdef CONFIG_X86_64 378003ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3781cb0f722aSWei Huang if (!pml4_root) 3782cb0f722aSWei Huang goto err_pml4; 3783cb0f722aSWei Huang 3784a717a780SSean Christopherson if (need_pml5) { 3785cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3786cb0f722aSWei Huang if (!pml5_root) 3787cb0f722aSWei Huang goto err_pml5; 3788748e52b9SSean Christopherson } 3789cb0f722aSWei Huang #endif 3790748e52b9SSean Christopherson 3791748e52b9SSean Christopherson mmu->pae_root = pae_root; 379203ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3793cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3794748e52b9SSean Christopherson 3795748e52b9SSean Christopherson return 0; 3796cb0f722aSWei Huang 3797cb0f722aSWei Huang #ifdef CONFIG_X86_64 3798cb0f722aSWei Huang err_pml5: 3799cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3800cb0f722aSWei Huang err_pml4: 3801cb0f722aSWei Huang free_page((unsigned long)pae_root); 3802cb0f722aSWei Huang return -ENOMEM; 3803cb0f722aSWei Huang #endif 3804c50d8ae3SPaolo Bonzini } 3805c50d8ae3SPaolo Bonzini 3806264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3807264d3dc1SLai Jiangshan { 3808264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3809264d3dc1SLai Jiangshan 381061b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 381161b05a9fSLai Jiangshan return false; 381261b05a9fSLai Jiangshan 3813264d3dc1SLai Jiangshan /* 3814264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3815264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3816264d3dc1SLai Jiangshan * 3817264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3818264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3819264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3820264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3821264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3822264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3823264d3dc1SLai Jiangshan * requirement isn't satisfied. 3824264d3dc1SLai Jiangshan */ 3825264d3dc1SLai Jiangshan smp_rmb(); 3826264d3dc1SLai Jiangshan sp = to_shadow_page(root); 38275d6a3221SSean Christopherson 38285d6a3221SSean Christopherson /* 38295d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 38305d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 38315d6a3221SSean Christopherson */ 38325d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 38335d6a3221SSean Christopherson return false; 38345d6a3221SSean Christopherson 3835264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3836264d3dc1SLai Jiangshan return true; 3837264d3dc1SLai Jiangshan 3838264d3dc1SLai Jiangshan return false; 3839264d3dc1SLai Jiangshan } 3840264d3dc1SLai Jiangshan 3841c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3842c50d8ae3SPaolo Bonzini { 3843c50d8ae3SPaolo Bonzini int i; 3844c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3845c50d8ae3SPaolo Bonzini 3846347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3847c50d8ae3SPaolo Bonzini return; 3848c50d8ae3SPaolo Bonzini 3849b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3850c50d8ae3SPaolo Bonzini return; 3851c50d8ae3SPaolo Bonzini 3852c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3853c50d8ae3SPaolo Bonzini 38544d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3855b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3856e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3857c50d8ae3SPaolo Bonzini 3858264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3859c50d8ae3SPaolo Bonzini return; 3860c50d8ae3SPaolo Bonzini 3861531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 386265855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3863531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3864c50d8ae3SPaolo Bonzini return; 3865c50d8ae3SPaolo Bonzini } 3866c50d8ae3SPaolo Bonzini 3867531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3868c50d8ae3SPaolo Bonzini 3869c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3870c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3871c50d8ae3SPaolo Bonzini 3872c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 38732ca3129eSSean Christopherson root &= SPTE_BASE_ADDR_MASK; 3874e47c4aeeSSean Christopherson sp = to_shadow_page(root); 387565855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3876c50d8ae3SPaolo Bonzini } 3877c50d8ae3SPaolo Bonzini } 3878c50d8ae3SPaolo Bonzini 3879531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3880c50d8ae3SPaolo Bonzini } 3881c50d8ae3SPaolo Bonzini 388261b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 388361b05a9fSLai Jiangshan { 388461b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 388561b05a9fSLai Jiangshan int i; 388661b05a9fSLai Jiangshan 388761b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 388861b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 388961b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 389061b05a9fSLai Jiangshan 389161b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 38920c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 389361b05a9fSLai Jiangshan } 389461b05a9fSLai Jiangshan 38951f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 38965b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3897c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3898c50d8ae3SPaolo Bonzini { 3899c50d8ae3SPaolo Bonzini if (exception) 3900c50d8ae3SPaolo Bonzini exception->error_code = 0; 3901c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3902c50d8ae3SPaolo Bonzini } 3903c50d8ae3SPaolo Bonzini 3904c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3905c50d8ae3SPaolo Bonzini { 3906c50d8ae3SPaolo Bonzini /* 3907c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3908c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3909c50d8ae3SPaolo Bonzini */ 3910c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3911c50d8ae3SPaolo Bonzini return false; 3912c50d8ae3SPaolo Bonzini 3913c50d8ae3SPaolo Bonzini if (direct) 3914c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3915c50d8ae3SPaolo Bonzini 3916c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3917c50d8ae3SPaolo Bonzini } 3918c50d8ae3SPaolo Bonzini 391995fb5b02SBen Gardon /* 392095fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 392195fb5b02SBen Gardon * That SPTE may be non-present. 3922c5c8c7c5SDavid Matlack * 3923c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 392495fb5b02SBen Gardon */ 392539b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3926c50d8ae3SPaolo Bonzini { 3927c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 39282aa07893SSean Christopherson int leaf = -1; 392995fb5b02SBen Gardon u64 spte; 3930c50d8ae3SPaolo Bonzini 393139b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 393239b4d43eSSean Christopherson *root_level = iterator.level; 3933c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3934c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 393595fb5b02SBen Gardon leaf = iterator.level; 3936c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3937c50d8ae3SPaolo Bonzini 3938dde81f94SSean Christopherson sptes[leaf] = spte; 393995fb5b02SBen Gardon } 394095fb5b02SBen Gardon 394195fb5b02SBen Gardon return leaf; 394295fb5b02SBen Gardon } 394395fb5b02SBen Gardon 39449aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 394595fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 394695fb5b02SBen Gardon { 3947dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 394895fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 394939b4d43eSSean Christopherson int root, leaf, level; 395095fb5b02SBen Gardon bool reserved = false; 395195fb5b02SBen Gardon 3952c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3953c5c8c7c5SDavid Matlack 395463c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 395539b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 395695fb5b02SBen Gardon else 395739b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 395895fb5b02SBen Gardon 3959c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 3960c5c8c7c5SDavid Matlack 39612aa07893SSean Christopherson if (unlikely(leaf < 0)) { 39622aa07893SSean Christopherson *sptep = 0ull; 39632aa07893SSean Christopherson return reserved; 39642aa07893SSean Christopherson } 39652aa07893SSean Christopherson 39669aa41879SSean Christopherson *sptep = sptes[leaf]; 39679aa41879SSean Christopherson 39689aa41879SSean Christopherson /* 39699aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 39709aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 39719aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 39729aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 39739aa41879SSean Christopherson */ 39749aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 39759aa41879SSean Christopherson leaf++; 397695fb5b02SBen Gardon 397795fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 397895fb5b02SBen Gardon 39799aa41879SSean Christopherson for (level = root; level >= leaf; level--) 3980961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 3981c50d8ae3SPaolo Bonzini 3982c50d8ae3SPaolo Bonzini if (reserved) { 3983bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 3984c50d8ae3SPaolo Bonzini __func__, addr); 398595fb5b02SBen Gardon for (level = root; level >= leaf; level--) 3986bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 3987bb4cdf3aSSean Christopherson sptes[level], level, 3988961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 3989c50d8ae3SPaolo Bonzini } 3990ddce6208SSean Christopherson 3991c50d8ae3SPaolo Bonzini return reserved; 3992c50d8ae3SPaolo Bonzini } 3993c50d8ae3SPaolo Bonzini 3994c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3995c50d8ae3SPaolo Bonzini { 3996c50d8ae3SPaolo Bonzini u64 spte; 3997c50d8ae3SPaolo Bonzini bool reserved; 3998c50d8ae3SPaolo Bonzini 3999c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4000c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4001c50d8ae3SPaolo Bonzini 400295fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 4003c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 4004c50d8ae3SPaolo Bonzini return -EINVAL; 4005c50d8ae3SPaolo Bonzini 4006c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4007c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 40080a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4009c50d8ae3SPaolo Bonzini 4010c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4011c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4012c50d8ae3SPaolo Bonzini 4013c50d8ae3SPaolo Bonzini if (direct) 4014c50d8ae3SPaolo Bonzini addr = 0; 4015c50d8ae3SPaolo Bonzini 4016c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4017c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4018c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4019c50d8ae3SPaolo Bonzini } 4020c50d8ae3SPaolo Bonzini 4021c50d8ae3SPaolo Bonzini /* 4022c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4023c50d8ae3SPaolo Bonzini * the address. 4024c50d8ae3SPaolo Bonzini */ 4025c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4026c50d8ae3SPaolo Bonzini } 4027c50d8ae3SPaolo Bonzini 4028c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4029b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4030c50d8ae3SPaolo Bonzini { 4031b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4032c50d8ae3SPaolo Bonzini return false; 4033c50d8ae3SPaolo Bonzini 4034b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4035c50d8ae3SPaolo Bonzini return false; 4036c50d8ae3SPaolo Bonzini 4037c50d8ae3SPaolo Bonzini /* 4038c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4039c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4040c50d8ae3SPaolo Bonzini */ 40419d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 4042c50d8ae3SPaolo Bonzini return true; 4043c50d8ae3SPaolo Bonzini 4044c50d8ae3SPaolo Bonzini return false; 4045c50d8ae3SPaolo Bonzini } 4046c50d8ae3SPaolo Bonzini 4047c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4048c50d8ae3SPaolo Bonzini { 4049c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4050c50d8ae3SPaolo Bonzini u64 spte; 4051c50d8ae3SPaolo Bonzini 4052c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 40533e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4054c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4055c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4056c50d8ae3SPaolo Bonzini } 4057c50d8ae3SPaolo Bonzini 40586f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 40596f3c1fc5SLiang Zhang { 40606f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 40616f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 40626f3c1fc5SLiang Zhang 40636f3c1fc5SLiang Zhang if (id << 12 == 0) 40646f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 40656f3c1fc5SLiang Zhang 40666f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 40676f3c1fc5SLiang Zhang } 40686f3c1fc5SLiang Zhang 4069e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 40709f1a8526SSean Christopherson gfn_t gfn) 4071c50d8ae3SPaolo Bonzini { 4072c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4073c50d8ae3SPaolo Bonzini 40746f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4075c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4076347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 4077d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 4078c50d8ae3SPaolo Bonzini 40799f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 40809f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4081c50d8ae3SPaolo Bonzini } 4082c50d8ae3SPaolo Bonzini 40838a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 40848a009d5bSSean Christopherson { 40858a009d5bSSean Christopherson int r; 40868a009d5bSSean Christopherson 40878a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 40888a009d5bSSean Christopherson work->wakeup_all) 40898a009d5bSSean Christopherson return; 40908a009d5bSSean Christopherson 40918a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 40928a009d5bSSean Christopherson if (unlikely(r)) 40938a009d5bSSean Christopherson return; 40948a009d5bSSean Christopherson 40958a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 40968a009d5bSSean Christopherson work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu)) 40978a009d5bSSean Christopherson return; 40988a009d5bSSean Christopherson 40998a009d5bSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true); 41008a009d5bSSean Christopherson } 41018a009d5bSSean Christopherson 41025276c616SSean Christopherson static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4103c50d8ae3SPaolo Bonzini { 4104e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4105c50d8ae3SPaolo Bonzini bool async; 4106c50d8ae3SPaolo Bonzini 4107e0c37868SSean Christopherson /* 4108e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4109e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4110e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4111e0c37868SSean Christopherson */ 4112e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 41135276c616SSean Christopherson return RET_PF_RETRY; 4114e0c37868SSean Christopherson 41159cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4116c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 41179cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4118e710c5f6SDavid Matlack fault->slot = NULL; 41193647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 41203647cd04SPaolo Bonzini fault->map_writable = false; 41215276c616SSean Christopherson return RET_PF_CONTINUE; 4122c50d8ae3SPaolo Bonzini } 41239cc13d60SMaxim Levitsky /* 41249cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 41259cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 41269cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 41279cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 41289cc13d60SMaxim Levitsky */ 41299cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 41305276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 41315276c616SSean Christopherson return RET_PF_EMULATE; 41329cc13d60SMaxim Levitsky } 4133c50d8ae3SPaolo Bonzini 4134c50d8ae3SPaolo Bonzini async = false; 41353647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, 41363647cd04SPaolo Bonzini fault->write, &fault->map_writable, 41373647cd04SPaolo Bonzini &fault->hva); 4138c50d8ae3SPaolo Bonzini if (!async) 41395276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4140c50d8ae3SPaolo Bonzini 41412839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 41423647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 41433647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 41443647cd04SPaolo Bonzini trace_kvm_async_pf_doublefault(fault->addr, fault->gfn); 4145c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 41465276c616SSean Christopherson return RET_PF_RETRY; 41475276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 41485276c616SSean Christopherson return RET_PF_RETRY; 41495276c616SSean Christopherson } 4150c50d8ae3SPaolo Bonzini } 4151c50d8ae3SPaolo Bonzini 41523647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, 41533647cd04SPaolo Bonzini fault->write, &fault->map_writable, 41543647cd04SPaolo Bonzini &fault->hva); 41555276c616SSean Christopherson return RET_PF_CONTINUE; 4156c50d8ae3SPaolo Bonzini } 4157c50d8ae3SPaolo Bonzini 4158a955cad8SSean Christopherson /* 4159a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4160a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4161a955cad8SSean Christopherson */ 4162a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4163a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 4164a955cad8SSean Christopherson { 4165b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 416618c841e1SSean Christopherson 416718c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 416818c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 416918c841e1SSean Christopherson return true; 417018c841e1SSean Christopherson 417118c841e1SSean Christopherson /* 417218c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 417318c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 417418c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 417518c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 417618c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 417718c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 417818c841e1SSean Christopherson */ 4179527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4180a955cad8SSean Christopherson return true; 4181a955cad8SSean Christopherson 4182a955cad8SSean Christopherson return fault->slot && 4183a955cad8SSean Christopherson mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4184a955cad8SSean Christopherson } 4185a955cad8SSean Christopherson 41864326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4187c50d8ae3SPaolo Bonzini { 418863c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4189c50d8ae3SPaolo Bonzini 41900f90e1c1SSean Christopherson unsigned long mmu_seq; 419183f06fa7SSean Christopherson int r; 4192c50d8ae3SPaolo Bonzini 41933c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4194e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4195e710c5f6SDavid Matlack 4196b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4197c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4198c50d8ae3SPaolo Bonzini 41993c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4200c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4201c4371c2aSSean Christopherson return r; 420283291445SSean Christopherson 4203378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4204c50d8ae3SPaolo Bonzini if (r) 4205c50d8ae3SPaolo Bonzini return r; 4206c50d8ae3SPaolo Bonzini 4207367fd790SSean Christopherson mmu_seq = vcpu->kvm->mmu_notifier_seq; 4208367fd790SSean Christopherson smp_rmb(); 4209367fd790SSean Christopherson 42105276c616SSean Christopherson r = kvm_faultin_pfn(vcpu, fault); 42115276c616SSean Christopherson if (r != RET_PF_CONTINUE) 42128f32d5e5SMaxim Levitsky return r; 4213367fd790SSean Christopherson 42145276c616SSean Christopherson r = handle_abnormal_pfn(vcpu, fault, ACC_ALL); 42155276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4216367fd790SSean Christopherson return r; 4217367fd790SSean Christopherson 4218367fd790SSean Christopherson r = RET_PF_RETRY; 4219a2855afcSBen Gardon 42200b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4221a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4222a2855afcSBen Gardon else 4223531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4224a2855afcSBen Gardon 4225a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4226367fd790SSean Christopherson goto out_unlock; 4227a955cad8SSean Christopherson 42287bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 42297bd7ded6SSean Christopherson if (r) 4230367fd790SSean Christopherson goto out_unlock; 4231bb18842eSBen Gardon 42320b873fd7SDavid Matlack if (is_tdp_mmu_fault) 42332f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4234bb18842eSBen Gardon else 423543b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 42360f90e1c1SSean Christopherson 4237367fd790SSean Christopherson out_unlock: 42380b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4239a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4240a2855afcSBen Gardon else 4241531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 42423647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4243367fd790SSean Christopherson return r; 4244c50d8ae3SPaolo Bonzini } 4245c50d8ae3SPaolo Bonzini 4246c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4247c501040aSPaolo Bonzini struct kvm_page_fault *fault) 42480f90e1c1SSean Christopherson { 42494326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 42500f90e1c1SSean Christopherson 42510f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 42524326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 42534326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 42540f90e1c1SSean Christopherson } 42550f90e1c1SSean Christopherson 4256c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4257c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4258c50d8ae3SPaolo Bonzini { 4259c50d8ae3SPaolo Bonzini int r = 1; 42609ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4261c50d8ae3SPaolo Bonzini 4262736c291cSSean Christopherson #ifndef CONFIG_X86_64 4263736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4264736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4265736c291cSSean Christopherson return -EFAULT; 4266736c291cSSean Christopherson #endif 4267736c291cSSean Christopherson 4268c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 42699ce372b3SVitaly Kuznetsov if (!flags) { 4270c50d8ae3SPaolo Bonzini trace_kvm_page_fault(fault_address, error_code); 4271c50d8ae3SPaolo Bonzini 4272c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4273c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4274c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4275c50d8ae3SPaolo Bonzini insn_len); 42769ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 427768fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4278c50d8ae3SPaolo Bonzini local_irq_disable(); 42796bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4280c50d8ae3SPaolo Bonzini local_irq_enable(); 42819ce372b3SVitaly Kuznetsov } else { 42829ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4283c50d8ae3SPaolo Bonzini } 42849ce372b3SVitaly Kuznetsov 4285c50d8ae3SPaolo Bonzini return r; 4286c50d8ae3SPaolo Bonzini } 4287c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4288c50d8ae3SPaolo Bonzini 4289c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4290c50d8ae3SPaolo Bonzini { 42914326e57eSPaolo Bonzini while (fault->max_level > PG_LEVEL_4K) { 42924326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 42934326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4294c50d8ae3SPaolo Bonzini 4295cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4296cb9b88c6SSean Christopherson break; 42974326e57eSPaolo Bonzini 42984326e57eSPaolo Bonzini --fault->max_level; 4299c50d8ae3SPaolo Bonzini } 4300c50d8ae3SPaolo Bonzini 43014326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4302c50d8ae3SPaolo Bonzini } 4303c50d8ae3SPaolo Bonzini 430484a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4305c50d8ae3SPaolo Bonzini { 4306c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4307c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4308c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 43095efac074SPaolo Bonzini context->invlpg = NULL; 4310c50d8ae3SPaolo Bonzini } 4311c50d8ae3SPaolo Bonzini 4312be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 43130be44352SSean Christopherson union kvm_mmu_page_role role) 43140be44352SSean Christopherson { 4315be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 43165499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4317e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 43180be44352SSean Christopherson } 43190be44352SSean Christopherson 4320c50d8ae3SPaolo Bonzini /* 43215499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 43225499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 43235499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 43245499ea73SPaolo Bonzini * true is returned. 43255499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 43265499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4327c50d8ae3SPaolo Bonzini */ 43285499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 43295499ea73SPaolo Bonzini gpa_t new_pgd, 4330c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4331c50d8ae3SPaolo Bonzini { 4332c50d8ae3SPaolo Bonzini uint i; 4333c50d8ae3SPaolo Bonzini 4334b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 43350be44352SSean Christopherson return true; 43360be44352SSean Christopherson 4337c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 43385499ea73SPaolo Bonzini /* 43395499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 43405499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 43415499ea73SPaolo Bonzini * 0 C 1 2 3 43425499ea73SPaolo Bonzini * 1 C 0 2 3 43435499ea73SPaolo Bonzini * 2 C 0 1 3 43445499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 43455499ea73SPaolo Bonzini */ 4346b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4347b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 43485499ea73SPaolo Bonzini return true; 4349c50d8ae3SPaolo Bonzini } 4350c50d8ae3SPaolo Bonzini 43515499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 43525499ea73SPaolo Bonzini return false; 4353c50d8ae3SPaolo Bonzini } 4354c50d8ae3SPaolo Bonzini 4355c50d8ae3SPaolo Bonzini /* 43565499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 43575499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 43585499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 43595499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 43605499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 43615499ea73SPaolo Bonzini */ 43625499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 43635499ea73SPaolo Bonzini gpa_t new_pgd, 43645499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 43655499ea73SPaolo Bonzini { 43665499ea73SPaolo Bonzini uint i; 43675499ea73SPaolo Bonzini 43685499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 43695499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 43705499ea73SPaolo Bonzini goto hit; 43715499ea73SPaolo Bonzini 43725499ea73SPaolo Bonzini return false; 43735499ea73SPaolo Bonzini 43745499ea73SPaolo Bonzini hit: 43755499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 43765499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 43775499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 43785499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 43795499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 43805499ea73SPaolo Bonzini return true; 43815499ea73SPaolo Bonzini } 43825499ea73SPaolo Bonzini 43835499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 43845499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 43855499ea73SPaolo Bonzini { 43865499ea73SPaolo Bonzini /* 43875499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4388c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4389c50d8ae3SPaolo Bonzini * later if necessary. 4390c50d8ae3SPaolo Bonzini */ 43915499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 43925499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4393c50d8ae3SPaolo Bonzini 43945499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 43955499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 43965499ea73SPaolo Bonzini else 43975499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4398c50d8ae3SPaolo Bonzini } 4399c50d8ae3SPaolo Bonzini 4400d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4401c50d8ae3SPaolo Bonzini { 44020c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 44037a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 44040c1c92f1SPaolo Bonzini 44055499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 44065499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4407b869855bSSean Christopherson return; 4408c50d8ae3SPaolo Bonzini } 4409c50d8ae3SPaolo Bonzini 4410c50d8ae3SPaolo Bonzini /* 4411b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4412b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4413527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4414527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4415b869855bSSean Christopherson */ 4416b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4417b869855bSSean Christopherson 4418b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4419b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4420b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4421b5129100SSean Christopherson } 4422b869855bSSean Christopherson 4423b869855bSSean Christopherson /* 4424b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4425b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4426b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4427b869855bSSean Christopherson * the shadow page tables. 4428c50d8ae3SPaolo Bonzini */ 4429c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4430c50d8ae3SPaolo Bonzini 4431daa5b6c1SBen Gardon /* 4432daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4433daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4434daa5b6c1SBen Gardon */ 4435daa5b6c1SBen Gardon if (!new_role.direct) 4436daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4437b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4438c50d8ae3SPaolo Bonzini } 4439be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4440c50d8ae3SPaolo Bonzini 4441c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4442c50d8ae3SPaolo Bonzini { 4443c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4444c50d8ae3SPaolo Bonzini } 4445c50d8ae3SPaolo Bonzini 4446c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4447c3e5e415SLai Jiangshan unsigned int access) 4448c50d8ae3SPaolo Bonzini { 4449c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4450c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4451c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4452c50d8ae3SPaolo Bonzini return true; 4453c50d8ae3SPaolo Bonzini } 4454c50d8ae3SPaolo Bonzini 4455c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4456c50d8ae3SPaolo Bonzini return true; 4457c50d8ae3SPaolo Bonzini } 4458c50d8ae3SPaolo Bonzini 4459c50d8ae3SPaolo Bonzini return false; 4460c50d8ae3SPaolo Bonzini } 4461c50d8ae3SPaolo Bonzini 4462c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4463c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4464c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4465c50d8ae3SPaolo Bonzini #undef PTTYPE 4466c50d8ae3SPaolo Bonzini 4467c50d8ae3SPaolo Bonzini #define PTTYPE 64 4468c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4469c50d8ae3SPaolo Bonzini #undef PTTYPE 4470c50d8ae3SPaolo Bonzini 4471c50d8ae3SPaolo Bonzini #define PTTYPE 32 4472c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4473c50d8ae3SPaolo Bonzini #undef PTTYPE 4474c50d8ae3SPaolo Bonzini 4475c50d8ae3SPaolo Bonzini static void 4476b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 44775b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4478c50d8ae3SPaolo Bonzini bool pse, bool amd) 4479c50d8ae3SPaolo Bonzini { 4480c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4481c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 44825b7f575cSSean Christopherson u64 high_bits_rsvd; 4483c50d8ae3SPaolo Bonzini 4484c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4485c50d8ae3SPaolo Bonzini 4486c50d8ae3SPaolo Bonzini if (!gbpages) 4487c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4488c50d8ae3SPaolo Bonzini 44895b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 44905b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 44915b7f575cSSean Christopherson else 44925b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 44935b7f575cSSean Christopherson 44945b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 44955b7f575cSSean Christopherson if (!nx) 44965b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 44975b7f575cSSean Christopherson 4498c50d8ae3SPaolo Bonzini /* 4499c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4500c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4501c50d8ae3SPaolo Bonzini */ 4502c50d8ae3SPaolo Bonzini if (amd) 4503c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4504c50d8ae3SPaolo Bonzini 4505c50d8ae3SPaolo Bonzini switch (level) { 4506c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4507c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4508c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4509c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4510c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4511c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4512c50d8ae3SPaolo Bonzini 4513c50d8ae3SPaolo Bonzini if (!pse) { 4514c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4515c50d8ae3SPaolo Bonzini break; 4516c50d8ae3SPaolo Bonzini } 4517c50d8ae3SPaolo Bonzini 4518c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4519c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4520c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4521c50d8ae3SPaolo Bonzini else 4522c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4523c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4524c50d8ae3SPaolo Bonzini break; 4525c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 45265b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 45275b7f575cSSean Christopherson high_bits_rsvd | 45285b7f575cSSean Christopherson rsvd_bits(5, 8) | 45295b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 45305b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 45315b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 45325b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4533c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4534c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4535c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4536c50d8ae3SPaolo Bonzini break; 4537c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 45385b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 45395b7f575cSSean Christopherson nonleaf_bit8_rsvd | 45405b7f575cSSean Christopherson rsvd_bits(7, 7); 4541c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4542c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4543df561f66SGustavo A. R. Silva fallthrough; 4544c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 45455b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 45465b7f575cSSean Christopherson nonleaf_bit8_rsvd | 45475b7f575cSSean Christopherson rsvd_bits(7, 7); 45485b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 45495b7f575cSSean Christopherson gbpages_bit_rsvd; 45505b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 45515b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4552c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4553c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 45545b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 45555b7f575cSSean Christopherson gbpages_bit_rsvd | 4556c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 45575b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4558c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4559c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4560c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4561c50d8ae3SPaolo Bonzini break; 4562c50d8ae3SPaolo Bonzini } 4563c50d8ae3SPaolo Bonzini } 4564c50d8ae3SPaolo Bonzini 456527de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 456627de9250SSean Christopherson { 456727de9250SSean Christopherson /* 456827de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 456927de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 457027de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 457127de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 457227de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 457327de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 457427de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 457527de9250SSean Christopherson */ 457627de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 457727de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 457827de9250SSean Christopherson } 457927de9250SSean Christopherson 4580c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4581c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4582c50d8ae3SPaolo Bonzini { 4583b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 45845b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 45854d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 458627de9250SSean Christopherson guest_can_use_gbpages(vcpu), 45874e9c0d80SSean Christopherson is_cr4_pse(context), 458823493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4589c50d8ae3SPaolo Bonzini } 4590c50d8ae3SPaolo Bonzini 4591c50d8ae3SPaolo Bonzini static void 4592c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 459384ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4594c50d8ae3SPaolo Bonzini { 45955b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 459684ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4597c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4598c50d8ae3SPaolo Bonzini 459984ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 460084ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 460184ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 460284ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 460384ea5c09SLai Jiangshan 46045b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 46055b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 460684ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 460784ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 46085b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4609c50d8ae3SPaolo Bonzini 4610c50d8ae3SPaolo Bonzini /* large page */ 4611c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4612c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 461384ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 461484ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4615c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4616c50d8ae3SPaolo Bonzini 4617c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4618c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4619c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4620c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4621c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4622c50d8ae3SPaolo Bonzini if (!execonly) { 4623c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4624c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4625c50d8ae3SPaolo Bonzini } 4626c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4627c50d8ae3SPaolo Bonzini } 4628c50d8ae3SPaolo Bonzini 4629c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 463084ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4631c50d8ae3SPaolo Bonzini { 4632c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 463384ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 463484ea5c09SLai Jiangshan huge_page_level); 4635c50d8ae3SPaolo Bonzini } 4636c50d8ae3SPaolo Bonzini 46376f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 46386f8e65a6SSean Christopherson { 46396f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 46406f8e65a6SSean Christopherson } 46416f8e65a6SSean Christopherson 4642c50d8ae3SPaolo Bonzini /* 4643c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4644c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4645c50d8ae3SPaolo Bonzini * follow the features in guest. 4646c50d8ae3SPaolo Bonzini */ 464716be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 464816be1d12SSean Christopherson struct kvm_mmu *context) 4649c50d8ae3SPaolo Bonzini { 46508c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 46518c985b2dSSean Christopherson bool is_amd = true; 46528c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 46538c985b2dSSean Christopherson bool is_pse = false; 4654c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4655c50d8ae3SPaolo Bonzini int i; 4656c50d8ae3SPaolo Bonzini 4657a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 46588c985b2dSSean Christopherson 4659c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4660b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4661a972e29cSPaolo Bonzini context->root_role.level, 46627a458f0eSPaolo Bonzini context->root_role.efer_nx, 466327de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4664c50d8ae3SPaolo Bonzini 4665c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4666c50d8ae3SPaolo Bonzini return; 4667c50d8ae3SPaolo Bonzini 4668a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4669e54f1ff2SKai Huang /* 4670e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4671e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4672e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4673e54f1ff2SKai Huang * not allowed to be set. 4674e54f1ff2SKai Huang */ 4675e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4676e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4677e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4678e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4679c50d8ae3SPaolo Bonzini } 4680c50d8ae3SPaolo Bonzini 4681c50d8ae3SPaolo Bonzini } 4682c50d8ae3SPaolo Bonzini 4683c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4684c50d8ae3SPaolo Bonzini { 4685c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4686c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4687c50d8ae3SPaolo Bonzini } 4688c50d8ae3SPaolo Bonzini 4689c50d8ae3SPaolo Bonzini /* 4690c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4691c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4692c50d8ae3SPaolo Bonzini */ 4693c50d8ae3SPaolo Bonzini static void 4694e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4695c50d8ae3SPaolo Bonzini { 4696c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4697c50d8ae3SPaolo Bonzini int i; 4698c50d8ae3SPaolo Bonzini 4699c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4700c50d8ae3SPaolo Bonzini 4701c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4702b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4703a972e29cSPaolo Bonzini context->root_role.level, false, 4704c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 47058c985b2dSSean Christopherson false, true); 4706c50d8ae3SPaolo Bonzini else 4707c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 470884ea5c09SLai Jiangshan reserved_hpa_bits(), false, 470984ea5c09SLai Jiangshan max_huge_page_level); 4710c50d8ae3SPaolo Bonzini 4711c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4712c50d8ae3SPaolo Bonzini return; 4713c50d8ae3SPaolo Bonzini 4714a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4715c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4716c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4717c50d8ae3SPaolo Bonzini } 4718c50d8ae3SPaolo Bonzini } 4719c50d8ae3SPaolo Bonzini 4720c50d8ae3SPaolo Bonzini /* 4721c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4722c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4723c50d8ae3SPaolo Bonzini */ 4724c50d8ae3SPaolo Bonzini static void 4725e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4726c50d8ae3SPaolo Bonzini { 4727c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 472884ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 472984ea5c09SLai Jiangshan max_huge_page_level); 4730c50d8ae3SPaolo Bonzini } 4731c50d8ae3SPaolo Bonzini 4732c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4733c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4734c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4735c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4736c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4737c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4738c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4739c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4740c50d8ae3SPaolo Bonzini 4741c50d8ae3SPaolo Bonzini 4742c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4743c50d8ae3SPaolo Bonzini { 4744c50d8ae3SPaolo Bonzini unsigned byte; 4745c50d8ae3SPaolo Bonzini 4746c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4747c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4748c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4749c50d8ae3SPaolo Bonzini 4750c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4751c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4752c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 475390599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4754c50d8ae3SPaolo Bonzini 4755c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4756c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4757c50d8ae3SPaolo Bonzini 4758c50d8ae3SPaolo Bonzini /* 4759c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4760c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4761c50d8ae3SPaolo Bonzini */ 4762c50d8ae3SPaolo Bonzini 4763c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4764c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4765c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4766c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4767c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4768c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4769c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4770c50d8ae3SPaolo Bonzini u8 smepf = 0; 4771c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4772c50d8ae3SPaolo Bonzini u8 smapf = 0; 4773c50d8ae3SPaolo Bonzini 4774c50d8ae3SPaolo Bonzini if (!ept) { 4775c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4776c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4777c50d8ae3SPaolo Bonzini 4778c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 477990599c28SSean Christopherson if (!efer_nx) 4780c50d8ae3SPaolo Bonzini ff = 0; 4781c50d8ae3SPaolo Bonzini 4782c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4783c50d8ae3SPaolo Bonzini if (!cr0_wp) 4784c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4785c50d8ae3SPaolo Bonzini 4786c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4787c50d8ae3SPaolo Bonzini if (cr4_smep) 4788c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4789c50d8ae3SPaolo Bonzini 4790c50d8ae3SPaolo Bonzini /* 4791c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4792c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4793c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4794c50d8ae3SPaolo Bonzini * conditions are true: 4795c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4796c50d8ae3SPaolo Bonzini * - A user page is accessed 4797c50d8ae3SPaolo Bonzini * - The access is not a fetch 47984f4aa80eSLai Jiangshan * - The access is supervisor mode 47994f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4800c50d8ae3SPaolo Bonzini * 480194b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 480294b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4803c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4804c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4805c50d8ae3SPaolo Bonzini */ 4806c50d8ae3SPaolo Bonzini if (cr4_smap) 4807c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4808c50d8ae3SPaolo Bonzini } 4809c50d8ae3SPaolo Bonzini 4810c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4811c50d8ae3SPaolo Bonzini } 4812c50d8ae3SPaolo Bonzini } 4813c50d8ae3SPaolo Bonzini 4814c50d8ae3SPaolo Bonzini /* 4815c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4816c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4817c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4818c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4819c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4820c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4821c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4822c50d8ae3SPaolo Bonzini * 4823c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4824c50d8ae3SPaolo Bonzini * page tables and the machine state: 4825c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4826c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4827c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4828c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4829c50d8ae3SPaolo Bonzini * 4830c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4831c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4832c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4833c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4834c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4835c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4836c50d8ae3SPaolo Bonzini * only will be masked away. 4837c50d8ae3SPaolo Bonzini */ 48382e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4839c50d8ae3SPaolo Bonzini { 4840c50d8ae3SPaolo Bonzini unsigned bit; 4841c50d8ae3SPaolo Bonzini bool wp; 4842c50d8ae3SPaolo Bonzini 4843c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4844a3ca5281SChenyi Qiang 4845a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4846c50d8ae3SPaolo Bonzini return; 4847c50d8ae3SPaolo Bonzini 48482e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4849c50d8ae3SPaolo Bonzini 4850c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4851c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4852c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4853c50d8ae3SPaolo Bonzini 4854c50d8ae3SPaolo Bonzini pfec = bit << 1; 4855c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4856c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4857c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4858c50d8ae3SPaolo Bonzini 4859c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4860c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4861c50d8ae3SPaolo Bonzini 4862c50d8ae3SPaolo Bonzini /* 4863c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4864c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4865c50d8ae3SPaolo Bonzini */ 4866c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4867c50d8ae3SPaolo Bonzini /* 4868c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4869c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4870c50d8ae3SPaolo Bonzini */ 4871c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4872c50d8ae3SPaolo Bonzini 4873c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4874c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4875c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4876c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4877c50d8ae3SPaolo Bonzini 4878c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4879c50d8ae3SPaolo Bonzini } 4880c50d8ae3SPaolo Bonzini } 4881c50d8ae3SPaolo Bonzini 4882533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4883533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4884c50d8ae3SPaolo Bonzini { 4885533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4886533f9a4bSSean Christopherson return; 4887c50d8ae3SPaolo Bonzini 4888c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 4889533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4890533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4891c50d8ae3SPaolo Bonzini } 4892c50d8ae3SPaolo Bonzini 4893fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4894c50d8ae3SPaolo Bonzini { 4895c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4896c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4897c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4898c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4899c50d8ae3SPaolo Bonzini } 4900c50d8ae3SPaolo Bonzini 490184a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4902c50d8ae3SPaolo Bonzini { 4903c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4904c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4905c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4906c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4907c50d8ae3SPaolo Bonzini } 4908c50d8ae3SPaolo Bonzini 49097a7ae829SPaolo Bonzini static union kvm_cpu_role 4910e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 4911e5ed0fb0SPaolo Bonzini { 49127a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4913e5ed0fb0SPaolo Bonzini 4914e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 4915e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 4916e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4917e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 4918e5ed0fb0SPaolo Bonzini 4919e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 4920e5ed0fb0SPaolo Bonzini role.base.direct = 1; 4921e5ed0fb0SPaolo Bonzini return role; 4922e5ed0fb0SPaolo Bonzini } 4923e5ed0fb0SPaolo Bonzini 4924e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 4925e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 4926e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 4927e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 4928e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 492960f3cb60SPaolo Bonzini 493060f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 493160f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 493260f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 493360f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 493460f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 493560f3cb60SPaolo Bonzini else 493660f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 4937e5ed0fb0SPaolo Bonzini 4938e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 4939e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 4940e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 4941e5ed0fb0SPaolo Bonzini 4942e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 4943e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 4944e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 4945e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 4946e5ed0fb0SPaolo Bonzini return role; 4947e5ed0fb0SPaolo Bonzini } 4948e5ed0fb0SPaolo Bonzini 4949d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 4950d468d94bSSean Christopherson { 4951746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 4952746700d2SWei Huang if (tdp_root_level) 4953746700d2SWei Huang return tdp_root_level; 4954746700d2SWei Huang 4955d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 495683013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 4957d468d94bSSean Christopherson return 4; 4958d468d94bSSean Christopherson 495983013059SSean Christopherson return max_tdp_level; 4960d468d94bSSean Christopherson } 4961d468d94bSSean Christopherson 49627a458f0eSPaolo Bonzini static union kvm_mmu_page_role 49638626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 49647a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 4965c50d8ae3SPaolo Bonzini { 49667a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 4967c50d8ae3SPaolo Bonzini 49687a458f0eSPaolo Bonzini role.access = ACC_ALL; 49697a458f0eSPaolo Bonzini role.cr0_wp = true; 49707a458f0eSPaolo Bonzini role.efer_nx = true; 49717a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 49727a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 497354275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 49747a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 49757a458f0eSPaolo Bonzini role.direct = true; 49767a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 4977c50d8ae3SPaolo Bonzini 4978c50d8ae3SPaolo Bonzini return role; 4979c50d8ae3SPaolo Bonzini } 4980c50d8ae3SPaolo Bonzini 498139e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 4982a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 4983c50d8ae3SPaolo Bonzini { 49848c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 49857a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 4986c50d8ae3SPaolo Bonzini 4987e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 49887a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 4989c50d8ae3SPaolo Bonzini return; 4990c50d8ae3SPaolo Bonzini 4991e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 49927a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 49937a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 4994c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 49955efac074SPaolo Bonzini context->invlpg = NULL; 4996d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4997c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4998c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 4999c50d8ae3SPaolo Bonzini 500036f26787SSean Christopherson if (!is_cr0_pg(context)) 5001c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 500236f26787SSean Christopherson else if (is_cr4_pae(context)) 5003c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5004f4bd6f73SSean Christopherson else 5005c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5006c50d8ae3SPaolo Bonzini 5007533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5008e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5009c50d8ae3SPaolo Bonzini } 5010c50d8ae3SPaolo Bonzini 50118c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 50127a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 50137a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5014c50d8ae3SPaolo Bonzini { 5015e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 50167a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 501718db1b17SSean Christopherson return; 5018c50d8ae3SPaolo Bonzini 5019e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 50207a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 502118db1b17SSean Christopherson 502236f26787SSean Christopherson if (!is_cr0_pg(context)) 502384a16226SSean Christopherson nonpaging_init_context(context); 502436f26787SSean Christopherson else if (is_cr4_pae(context)) 5025fe660f72SSean Christopherson paging64_init_context(context); 5026c50d8ae3SPaolo Bonzini else 502784a16226SSean Christopherson paging32_init_context(context); 5028c50d8ae3SPaolo Bonzini 5029533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5030c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5031c50d8ae3SPaolo Bonzini } 50320f04a2acSVitaly Kuznetsov 5033594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5034a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 50350f04a2acSVitaly Kuznetsov { 50368c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 503756b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 503856b321f9SPaolo Bonzini 503956b321f9SPaolo Bonzini root_role = cpu_role.base; 504056b321f9SPaolo Bonzini 504156b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 504256b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 504356b321f9SPaolo Bonzini 504456b321f9SPaolo Bonzini /* 504556b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 504656b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 504756b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 504856b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 504956b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 505056b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 505156b321f9SPaolo Bonzini * MMU contexts. 505256b321f9SPaolo Bonzini */ 505356b321f9SPaolo Bonzini root_role.efer_nx = true; 50540f04a2acSVitaly Kuznetsov 50557a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 50560f04a2acSVitaly Kuznetsov } 50570f04a2acSVitaly Kuznetsov 5058dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5059dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 50600f04a2acSVitaly Kuznetsov { 50618c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5062594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5063594e91a1SSean Christopherson .cr0 = cr0, 506428f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5065594e91a1SSean Christopherson .efer = efer, 5066594e91a1SSean Christopherson }; 50677a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 506856b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 506956b321f9SPaolo Bonzini 507056b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 507156b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 507256b321f9SPaolo Bonzini 507356b321f9SPaolo Bonzini root_role = cpu_role.base; 507456b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 507584e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 507684e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 507784e5ffd0SLai Jiangshan root_role.passthrough = 1; 50780f04a2acSVitaly Kuznetsov 50797a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5080d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 50810f04a2acSVitaly Kuznetsov } 50820f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5083c50d8ae3SPaolo Bonzini 50847a7ae829SPaolo Bonzini static union kvm_cpu_role 5085c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5086bb1fcc70SSean Christopherson bool execonly, u8 level) 5087c50d8ae3SPaolo Bonzini { 50887a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5089c50d8ae3SPaolo Bonzini 5090daed87b8SPaolo Bonzini /* 5091daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5092daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5093daed87b8SPaolo Bonzini */ 5094daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5095bb1fcc70SSean Christopherson role.base.level = level; 5096bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5097c50d8ae3SPaolo Bonzini role.base.direct = false; 5098c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5099c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5100c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5101c50d8ae3SPaolo Bonzini 5102cd6767c3SSean Christopherson role.ext.word = 0; 5103c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5104cd6767c3SSean Christopherson role.ext.valid = 1; 5105c50d8ae3SPaolo Bonzini 5106c50d8ae3SPaolo Bonzini return role; 5107c50d8ae3SPaolo Bonzini } 5108c50d8ae3SPaolo Bonzini 5109c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5110cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5111cc022ae1SLai Jiangshan gpa_t new_eptp) 5112c50d8ae3SPaolo Bonzini { 51138c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5114bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 51157a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5116c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5117bb1fcc70SSean Christopherson execonly, level); 5118c50d8ae3SPaolo Bonzini 5119e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5120e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5121e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 51227a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 512318db1b17SSean Christopherson 5124c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5125c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5126c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 5127c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 5128347a0d0dSPaolo Bonzini 5129c596f147SSean Christopherson update_permission_bitmask(context, true); 513028f091bcSPaolo Bonzini context->pkru_mask = 0; 5131cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5132e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5133c50d8ae3SPaolo Bonzini } 51343cffc89dSPaolo Bonzini 5135d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 51363cffc89dSPaolo Bonzini } 5137c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5138c50d8ae3SPaolo Bonzini 513939e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5140a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5141c50d8ae3SPaolo Bonzini { 51428c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5143c50d8ae3SPaolo Bonzini 5144a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5145929d1cfaSPaolo Bonzini 5146d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5147c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5148c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5149c50d8ae3SPaolo Bonzini } 5150c50d8ae3SPaolo Bonzini 515139e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5152a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5153c50d8ae3SPaolo Bonzini { 5154c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5155c50d8ae3SPaolo Bonzini 5156e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5157c50d8ae3SPaolo Bonzini return; 5158c50d8ae3SPaolo Bonzini 5159e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5160d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5161c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5162c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5163c50d8ae3SPaolo Bonzini 5164c50d8ae3SPaolo Bonzini /* 51655efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 51665efac074SPaolo Bonzini * SPTEs. 51675efac074SPaolo Bonzini */ 51685efac074SPaolo Bonzini g_context->invlpg = NULL; 51695efac074SPaolo Bonzini 51705efac074SPaolo Bonzini /* 5171c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5172c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5173c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5174c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5175c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5176c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5177c50d8ae3SPaolo Bonzini */ 5178fa4b5588SSean Christopherson if (!is_paging(vcpu)) 51791f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5180fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 51811f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5182fa4b5588SSean Christopherson else if (is_pae(vcpu)) 51831f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5184fa4b5588SSean Christopherson else 51851f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5186fa4b5588SSean Christopherson 5187533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5188c50d8ae3SPaolo Bonzini } 5189c50d8ae3SPaolo Bonzini 5190c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5191c50d8ae3SPaolo Bonzini { 519239e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5193a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 519439e7e2bfSPaolo Bonzini 5195c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5196a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5197c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5198a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5199c50d8ae3SPaolo Bonzini else 5200a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5201c50d8ae3SPaolo Bonzini } 5202c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5203c50d8ae3SPaolo Bonzini 520449c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 520549c6f875SSean Christopherson { 520649c6f875SSean Christopherson /* 520749c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 520849c6f875SSean Christopherson * information is factored into reserved bit calculations. 5209feb627e8SVitaly Kuznetsov * 5210feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5211feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5212feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5213feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5214feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5215feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5216feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 521749c6f875SSean Christopherson */ 52187a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 52197a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 52207a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5221e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5222e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5223e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 522449c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 522563f5a190SSean Christopherson 522663f5a190SSean Christopherson /* 5227feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5228feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 522963f5a190SSean Christopherson */ 5230feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 523149c6f875SSean Christopherson } 523249c6f875SSean Christopherson 5233c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5234c50d8ae3SPaolo Bonzini { 5235c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5236c9060662SSean Christopherson kvm_init_mmu(vcpu); 5237c50d8ae3SPaolo Bonzini } 5238c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5239c50d8ae3SPaolo Bonzini 5240c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5241c50d8ae3SPaolo Bonzini { 5242c50d8ae3SPaolo Bonzini int r; 5243c50d8ae3SPaolo Bonzini 5244347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5245c50d8ae3SPaolo Bonzini if (r) 5246c50d8ae3SPaolo Bonzini goto out; 5247748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5248c50d8ae3SPaolo Bonzini if (r) 5249c50d8ae3SPaolo Bonzini goto out; 5250347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 52516e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 52526e6ec584SSean Christopherson else 52536e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5254c50d8ae3SPaolo Bonzini if (r) 5255c50d8ae3SPaolo Bonzini goto out; 5256a91f387bSSean Christopherson 5257a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5258a91f387bSSean Christopherson 5259727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5260db01416bSSean Christopherson 5261db01416bSSean Christopherson /* 5262db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5263db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5264db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5265db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5266db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5267db01416bSSean Christopherson */ 5268e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5269c50d8ae3SPaolo Bonzini out: 5270c50d8ae3SPaolo Bonzini return r; 5271c50d8ae3SPaolo Bonzini } 5272c50d8ae3SPaolo Bonzini 5273c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5274c50d8ae3SPaolo Bonzini { 52750c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 52760c1c92f1SPaolo Bonzini 52770c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5278b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 52790c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5280b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 52816d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5282c50d8ae3SPaolo Bonzini } 5283c50d8ae3SPaolo Bonzini 5284527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5285527d5cd7SSean Christopherson { 5286527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5287527d5cd7SSean Christopherson 5288527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5289527d5cd7SSean Christopherson return false; 5290527d5cd7SSean Christopherson 5291527d5cd7SSean Christopherson /* 5292527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5293527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5294527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5295527d5cd7SSean Christopherson * such false positives are relatively rare: 5296527d5cd7SSean Christopherson * 5297527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5298527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5299527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5300527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5301527d5cd7SSean Christopherson */ 5302527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5303527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5304527d5cd7SSean Christopherson } 5305527d5cd7SSean Christopherson 5306527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5307527d5cd7SSean Christopherson { 5308527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5309527d5cd7SSean Christopherson int i; 5310527d5cd7SSean Christopherson 5311527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5312527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5313527d5cd7SSean Christopherson 5314527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5315cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5316527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5317527d5cd7SSean Christopherson } 5318527d5cd7SSean Christopherson 5319527d5cd7SSean Christopherson if (roots_to_free) 5320527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5321527d5cd7SSean Christopherson } 5322527d5cd7SSean Christopherson 5323527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5324527d5cd7SSean Christopherson { 5325527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5326527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5327527d5cd7SSean Christopherson } 5328527d5cd7SSean Christopherson 5329c50d8ae3SPaolo Bonzini static bool need_remote_flush(u64 old, u64 new) 5330c50d8ae3SPaolo Bonzini { 5331c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old)) 5332c50d8ae3SPaolo Bonzini return false; 5333c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(new)) 5334c50d8ae3SPaolo Bonzini return true; 53352ca3129eSSean Christopherson if ((old ^ new) & SPTE_BASE_ADDR_MASK) 5336c50d8ae3SPaolo Bonzini return true; 5337c50d8ae3SPaolo Bonzini old ^= shadow_nx_mask; 5338c50d8ae3SPaolo Bonzini new ^= shadow_nx_mask; 53392ca3129eSSean Christopherson return (old & ~new & SPTE_PERM_MASK) != 0; 5340c50d8ae3SPaolo Bonzini } 5341c50d8ae3SPaolo Bonzini 5342c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5343c50d8ae3SPaolo Bonzini int *bytes) 5344c50d8ae3SPaolo Bonzini { 5345c50d8ae3SPaolo Bonzini u64 gentry = 0; 5346c50d8ae3SPaolo Bonzini int r; 5347c50d8ae3SPaolo Bonzini 5348c50d8ae3SPaolo Bonzini /* 5349c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5350c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5351c50d8ae3SPaolo Bonzini * when they have the same mode. 5352c50d8ae3SPaolo Bonzini */ 5353c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5354c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5355c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5356c50d8ae3SPaolo Bonzini *bytes = 8; 5357c50d8ae3SPaolo Bonzini } 5358c50d8ae3SPaolo Bonzini 5359c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5360c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5361c50d8ae3SPaolo Bonzini if (r) 5362c50d8ae3SPaolo Bonzini gentry = 0; 5363c50d8ae3SPaolo Bonzini } 5364c50d8ae3SPaolo Bonzini 5365c50d8ae3SPaolo Bonzini return gentry; 5366c50d8ae3SPaolo Bonzini } 5367c50d8ae3SPaolo Bonzini 5368c50d8ae3SPaolo Bonzini /* 5369c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5370c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5371c50d8ae3SPaolo Bonzini */ 5372c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5373c50d8ae3SPaolo Bonzini { 5374c50d8ae3SPaolo Bonzini /* 5375c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5376c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5377c50d8ae3SPaolo Bonzini */ 53783bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5379c50d8ae3SPaolo Bonzini return false; 5380c50d8ae3SPaolo Bonzini 5381c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5382c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5383c50d8ae3SPaolo Bonzini } 5384c50d8ae3SPaolo Bonzini 5385c50d8ae3SPaolo Bonzini /* 5386c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5387c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5388c50d8ae3SPaolo Bonzini */ 5389c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5390c50d8ae3SPaolo Bonzini int bytes) 5391c50d8ae3SPaolo Bonzini { 5392c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5393c50d8ae3SPaolo Bonzini 5394c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5395c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5396c50d8ae3SPaolo Bonzini 5397c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5398bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5399c50d8ae3SPaolo Bonzini 5400c50d8ae3SPaolo Bonzini /* 5401c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5402c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5403c50d8ae3SPaolo Bonzini */ 5404c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5405c50d8ae3SPaolo Bonzini return false; 5406c50d8ae3SPaolo Bonzini 5407c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5408c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5409c50d8ae3SPaolo Bonzini 5410c50d8ae3SPaolo Bonzini return misaligned; 5411c50d8ae3SPaolo Bonzini } 5412c50d8ae3SPaolo Bonzini 5413c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5414c50d8ae3SPaolo Bonzini { 5415c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5416c50d8ae3SPaolo Bonzini u64 *spte; 5417c50d8ae3SPaolo Bonzini int level; 5418c50d8ae3SPaolo Bonzini 5419c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5420c50d8ae3SPaolo Bonzini level = sp->role.level; 5421c50d8ae3SPaolo Bonzini *nspte = 1; 5422bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5423c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5424c50d8ae3SPaolo Bonzini /* 5425c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5426c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5427c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5428c50d8ae3SPaolo Bonzini */ 5429c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5430c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5431c50d8ae3SPaolo Bonzini page_offset <<= 1; 5432c50d8ae3SPaolo Bonzini *nspte = 2; 5433c50d8ae3SPaolo Bonzini } 5434c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5435c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5436c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5437c50d8ae3SPaolo Bonzini return NULL; 5438c50d8ae3SPaolo Bonzini } 5439c50d8ae3SPaolo Bonzini 5440c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5441c50d8ae3SPaolo Bonzini return spte; 5442c50d8ae3SPaolo Bonzini } 5443c50d8ae3SPaolo Bonzini 5444c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5445c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5446c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5447c50d8ae3SPaolo Bonzini { 5448c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5449c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5450c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5451c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5452c50d8ae3SPaolo Bonzini int npte; 545306152b2dSLai Jiangshan bool flush = false; 5454c50d8ae3SPaolo Bonzini 5455c50d8ae3SPaolo Bonzini /* 5456c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5457c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5458c50d8ae3SPaolo Bonzini */ 5459c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5460c50d8ae3SPaolo Bonzini return; 5461c50d8ae3SPaolo Bonzini 5462c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5463c50d8ae3SPaolo Bonzini 5464531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5465c50d8ae3SPaolo Bonzini 5466c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5467c50d8ae3SPaolo Bonzini 5468c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5469c50d8ae3SPaolo Bonzini 5470767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5471c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5472c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5473c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5474c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5475c50d8ae3SPaolo Bonzini continue; 5476c50d8ae3SPaolo Bonzini } 5477c50d8ae3SPaolo Bonzini 5478c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5479c50d8ae3SPaolo Bonzini if (!spte) 5480c50d8ae3SPaolo Bonzini continue; 5481c50d8ae3SPaolo Bonzini 5482c50d8ae3SPaolo Bonzini while (npte--) { 5483c50d8ae3SPaolo Bonzini entry = *spte; 54842de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5485c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5486c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 5487c50d8ae3SPaolo Bonzini if (need_remote_flush(entry, *spte)) 548806152b2dSLai Jiangshan flush = true; 5489c50d8ae3SPaolo Bonzini ++spte; 5490c50d8ae3SPaolo Bonzini } 5491c50d8ae3SPaolo Bonzini } 549206152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5493531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5494c50d8ae3SPaolo Bonzini } 5495c50d8ae3SPaolo Bonzini 54961075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5497c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5498c50d8ae3SPaolo Bonzini { 549992daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5500347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5501c50d8ae3SPaolo Bonzini 5502b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5503ddce6208SSean Christopherson return RET_PF_RETRY; 5504ddce6208SSean Christopherson 5505c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5506c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5507736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5508c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5509c50d8ae3SPaolo Bonzini goto emulate; 5510c50d8ae3SPaolo Bonzini } 5511c50d8ae3SPaolo Bonzini 5512c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 55137a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 55147a02674dSSean Christopherson lower_32_bits(error_code), false); 551519025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 55167b367bc9SSean Christopherson return -EIO; 5517c50d8ae3SPaolo Bonzini } 5518c50d8ae3SPaolo Bonzini 5519c50d8ae3SPaolo Bonzini if (r < 0) 5520c50d8ae3SPaolo Bonzini return r; 552183a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 552283a2ba4cSSean Christopherson return 1; 5523c50d8ae3SPaolo Bonzini 5524c50d8ae3SPaolo Bonzini /* 5525c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5526c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5527c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5528c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5529c50d8ae3SPaolo Bonzini * and resume the guest. 5530c50d8ae3SPaolo Bonzini */ 5531347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5532c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5533736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5534c50d8ae3SPaolo Bonzini return 1; 5535c50d8ae3SPaolo Bonzini } 5536c50d8ae3SPaolo Bonzini 5537c50d8ae3SPaolo Bonzini /* 5538c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5539c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5540c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5541c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5542c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5543c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5544c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5545c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5546c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5547c50d8ae3SPaolo Bonzini */ 5548736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 554992daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5550c50d8ae3SPaolo Bonzini emulate: 5551736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5552c50d8ae3SPaolo Bonzini insn_len); 5553c50d8ae3SPaolo Bonzini } 5554c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5555c50d8ae3SPaolo Bonzini 55565efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 55575efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5558c50d8ae3SPaolo Bonzini { 5559c50d8ae3SPaolo Bonzini int i; 5560c50d8ae3SPaolo Bonzini 55615efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 55625efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 55635efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5564c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5565c50d8ae3SPaolo Bonzini return; 5566c50d8ae3SPaolo Bonzini 5567e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 55685efac074SPaolo Bonzini } 55695efac074SPaolo Bonzini 55705efac074SPaolo Bonzini if (!mmu->invlpg) 55715efac074SPaolo Bonzini return; 55725efac074SPaolo Bonzini 55735efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5574b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5575c50d8ae3SPaolo Bonzini 5576c50d8ae3SPaolo Bonzini /* 5577c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5578c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5579c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5580c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5581c50d8ae3SPaolo Bonzini * just always sync it. 5582c50d8ae3SPaolo Bonzini * 5583c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5584c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5585c50d8ae3SPaolo Bonzini * for them. 5586c50d8ae3SPaolo Bonzini */ 5587c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5588c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5589c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 55905efac074SPaolo Bonzini } else { 55915efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 55925efac074SPaolo Bonzini } 55935efac074SPaolo Bonzini } 5594c50d8ae3SPaolo Bonzini 55955efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 55965efac074SPaolo Bonzini { 559705b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5598c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5599c50d8ae3SPaolo Bonzini } 5600c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5601c50d8ae3SPaolo Bonzini 56025efac074SPaolo Bonzini 5603c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5604c50d8ae3SPaolo Bonzini { 5605c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5606c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5607c50d8ae3SPaolo Bonzini uint i; 5608c50d8ae3SPaolo Bonzini 5609c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 56109f46c187SPaolo Bonzini if (mmu->invlpg) 5611b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5612c50d8ae3SPaolo Bonzini tlb_flush = true; 5613c50d8ae3SPaolo Bonzini } 5614c50d8ae3SPaolo Bonzini 5615c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5616c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5617be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 56189f46c187SPaolo Bonzini if (mmu->invlpg) 5619c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5620c50d8ae3SPaolo Bonzini tlb_flush = true; 5621c50d8ae3SPaolo Bonzini } 5622c50d8ae3SPaolo Bonzini } 5623c50d8ae3SPaolo Bonzini 5624c50d8ae3SPaolo Bonzini if (tlb_flush) 5625e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5626c50d8ae3SPaolo Bonzini 5627c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5628c50d8ae3SPaolo Bonzini 5629c50d8ae3SPaolo Bonzini /* 5630c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5631c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5632c50d8ae3SPaolo Bonzini * for them. 5633c50d8ae3SPaolo Bonzini */ 5634c50d8ae3SPaolo Bonzini } 5635c50d8ae3SPaolo Bonzini 5636746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5637746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5638c50d8ae3SPaolo Bonzini { 5639bde77235SSean Christopherson tdp_enabled = enable_tdp; 5640746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 564183013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5642703c335dSSean Christopherson 5643703c335dSSean Christopherson /* 56441d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5645703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5646703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5647703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5648703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5649703c335dSSean Christopherson */ 5650703c335dSSean Christopherson if (tdp_enabled) 56511d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5652703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 56531d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5654703c335dSSean Christopherson else 56551d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5656c50d8ae3SPaolo Bonzini } 5657bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5658c50d8ae3SPaolo Bonzini 5659c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5660269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5661269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5662269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5663c50d8ae3SPaolo Bonzini 5664c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5665c50d8ae3SPaolo Bonzini static __always_inline bool 5666269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5667c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 56681a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 56691a61b7dbSSean Christopherson bool flush) 5670c50d8ae3SPaolo Bonzini { 5671c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5672c50d8ae3SPaolo Bonzini 5673c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5674c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5675c50d8ae3SPaolo Bonzini if (iterator.rmap) 56760a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5677c50d8ae3SPaolo Bonzini 5678531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5679302695a5SSean Christopherson if (flush && flush_on_yield) { 5680c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5681c50d8ae3SPaolo Bonzini start_gfn, 5682c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5683c50d8ae3SPaolo Bonzini flush = false; 5684c50d8ae3SPaolo Bonzini } 5685531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5686c50d8ae3SPaolo Bonzini } 5687c50d8ae3SPaolo Bonzini } 5688c50d8ae3SPaolo Bonzini 5689c50d8ae3SPaolo Bonzini return flush; 5690c50d8ae3SPaolo Bonzini } 5691c50d8ae3SPaolo Bonzini 5692c50d8ae3SPaolo Bonzini static __always_inline bool 5693269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5694c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5695302695a5SSean Christopherson bool flush_on_yield) 5696c50d8ae3SPaolo Bonzini { 5697c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5698c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5699c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 57001a61b7dbSSean Christopherson flush_on_yield, false); 5701c50d8ae3SPaolo Bonzini } 5702c50d8ae3SPaolo Bonzini 5703c50d8ae3SPaolo Bonzini static __always_inline bool 5704610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5705302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5706c50d8ae3SPaolo Bonzini { 57073bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5708302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5709c50d8ae3SPaolo Bonzini } 5710c50d8ae3SPaolo Bonzini 5711c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5712c50d8ae3SPaolo Bonzini { 57134a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 57144a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5715c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 571603ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5717cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5718c50d8ae3SPaolo Bonzini } 5719c50d8ae3SPaolo Bonzini 572004d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5721c50d8ae3SPaolo Bonzini { 5722c50d8ae3SPaolo Bonzini struct page *page; 5723c50d8ae3SPaolo Bonzini int i; 5724c50d8ae3SPaolo Bonzini 5725b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5726b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 572704d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 572804d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 572904d28e37SSean Christopherson 573027f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 573127f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 573227f4fca2SLai Jiangshan return 0; 573327f4fca2SLai Jiangshan 5734c50d8ae3SPaolo Bonzini /* 5735c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5736c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5737c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5738c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 573904d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 574004d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 574104d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 574204d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 574384432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5744c50d8ae3SPaolo Bonzini */ 5745d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5746c50d8ae3SPaolo Bonzini return 0; 5747c50d8ae3SPaolo Bonzini 5748c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5749c50d8ae3SPaolo Bonzini if (!page) 5750c50d8ae3SPaolo Bonzini return -ENOMEM; 5751c50d8ae3SPaolo Bonzini 5752c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 57534a98623dSSean Christopherson 57544a98623dSSean Christopherson /* 57554a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 57564a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 57574a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 57584a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 57594a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 57604a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 57614a98623dSSean Christopherson */ 57624a98623dSSean Christopherson if (!tdp_enabled) 57634a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 57644a98623dSSean Christopherson else 5765e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 57664a98623dSSean Christopherson 5767c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5768c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5769c50d8ae3SPaolo Bonzini 5770c50d8ae3SPaolo Bonzini return 0; 5771c50d8ae3SPaolo Bonzini } 5772c50d8ae3SPaolo Bonzini 5773c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5774c50d8ae3SPaolo Bonzini { 5775c50d8ae3SPaolo Bonzini int ret; 5776c50d8ae3SPaolo Bonzini 57775962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 57785f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 57795f6078f9SSean Christopherson 57805962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 57815f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 57825962bfb7SSean Christopherson 578396880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 578496880883SSean Christopherson 5785c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5786c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5787c50d8ae3SPaolo Bonzini 578804d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5789c50d8ae3SPaolo Bonzini if (ret) 5790c50d8ae3SPaolo Bonzini return ret; 5791c50d8ae3SPaolo Bonzini 579204d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5793c50d8ae3SPaolo Bonzini if (ret) 5794c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5795c50d8ae3SPaolo Bonzini 5796c50d8ae3SPaolo Bonzini return ret; 5797c50d8ae3SPaolo Bonzini fail_allocate_root: 5798c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5799c50d8ae3SPaolo Bonzini return ret; 5800c50d8ae3SPaolo Bonzini } 5801c50d8ae3SPaolo Bonzini 5802c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5803c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5804c50d8ae3SPaolo Bonzini { 5805c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5806c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5807b28cb0cdSSean Christopherson bool unstable; 5808c50d8ae3SPaolo Bonzini 5809c50d8ae3SPaolo Bonzini restart: 5810c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5811c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5812c50d8ae3SPaolo Bonzini /* 5813c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5814c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5815c50d8ae3SPaolo Bonzini */ 5816c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5817c50d8ae3SPaolo Bonzini break; 5818c50d8ae3SPaolo Bonzini 5819c50d8ae3SPaolo Bonzini /* 5820f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5821f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5822f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5823c50d8ae3SPaolo Bonzini */ 5824f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5825c50d8ae3SPaolo Bonzini continue; 5826c50d8ae3SPaolo Bonzini 5827c50d8ae3SPaolo Bonzini /* 5828c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5829c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5830c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5831c50d8ae3SPaolo Bonzini * be in active use by the guest. 5832c50d8ae3SPaolo Bonzini */ 5833c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5834531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5835c50d8ae3SPaolo Bonzini batch = 0; 5836c50d8ae3SPaolo Bonzini goto restart; 5837c50d8ae3SPaolo Bonzini } 5838c50d8ae3SPaolo Bonzini 5839b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 5840b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 5841c50d8ae3SPaolo Bonzini batch += nr_zapped; 5842b28cb0cdSSean Christopherson 5843b28cb0cdSSean Christopherson if (unstable) 5844c50d8ae3SPaolo Bonzini goto restart; 5845c50d8ae3SPaolo Bonzini } 5846c50d8ae3SPaolo Bonzini 5847c50d8ae3SPaolo Bonzini /* 58487ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 58497ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 58507ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 58517ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 58527ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 58537ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 58547ae5840eSSean Christopherson * running with an obsolete MMU. 5855c50d8ae3SPaolo Bonzini */ 5856c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5857c50d8ae3SPaolo Bonzini } 5858c50d8ae3SPaolo Bonzini 5859c50d8ae3SPaolo Bonzini /* 5860c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5861c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5862c50d8ae3SPaolo Bonzini * 5863c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5864c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5865c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5866c50d8ae3SPaolo Bonzini * after calling the function. 5867c50d8ae3SPaolo Bonzini */ 5868c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5869c50d8ae3SPaolo Bonzini { 5870c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5871c50d8ae3SPaolo Bonzini 5872531810caSBen Gardon write_lock(&kvm->mmu_lock); 5873c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5874c50d8ae3SPaolo Bonzini 5875c50d8ae3SPaolo Bonzini /* 5876c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5877c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5878c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5879c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5880c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5881c50d8ae3SPaolo Bonzini */ 5882c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5883c50d8ae3SPaolo Bonzini 58842f6f66ccSSean Christopherson /* 58852f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 58862f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 58872f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 58882f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5889b7cccd39SBen Gardon */ 5890b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5891b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5892b7cccd39SBen Gardon 5893c50d8ae3SPaolo Bonzini /* 5894c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5895c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5896c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5897c50d8ae3SPaolo Bonzini * 5898c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5899c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5900c50d8ae3SPaolo Bonzini */ 5901527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5902c50d8ae3SPaolo Bonzini 5903c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5904faaf05b0SBen Gardon 5905531810caSBen Gardon write_unlock(&kvm->mmu_lock); 59064c6654bdSBen Gardon 5907f28e9c7fSSean Christopherson /* 5908f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5909f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5910f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5911f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5912f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5913f28e9c7fSSean Christopherson * lead to use-after-free. 5914f28e9c7fSSean Christopherson */ 591522b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 59164c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5917c50d8ae3SPaolo Bonzini } 5918c50d8ae3SPaolo Bonzini 5919c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5920c50d8ae3SPaolo Bonzini { 5921c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5922c50d8ae3SPaolo Bonzini } 5923c50d8ae3SPaolo Bonzini 5924c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5925c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5926c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5927c50d8ae3SPaolo Bonzini { 5928c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5929c50d8ae3SPaolo Bonzini } 5930c50d8ae3SPaolo Bonzini 5931a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5932c50d8ae3SPaolo Bonzini { 5933c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5934a1a39128SPaolo Bonzini int r; 5935c50d8ae3SPaolo Bonzini 5936a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5937a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5938a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5939ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5940ce25681dSSean Christopherson 5941a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5942a1a39128SPaolo Bonzini if (r < 0) 5943a1a39128SPaolo Bonzini return r; 5944fe5db27dSBen Gardon 5945c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5946c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5947c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5948ada51a9dSDavid Matlack 5949ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 5950ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 5951ada51a9dSDavid Matlack 5952ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 5953ada51a9dSDavid Matlack 5954ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 5955ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 5956ada51a9dSDavid Matlack 5957a1a39128SPaolo Bonzini return 0; 5958c50d8ae3SPaolo Bonzini } 5959c50d8ae3SPaolo Bonzini 5960ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 5961ada51a9dSDavid Matlack { 5962ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 5963ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 5964ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 5965ada51a9dSDavid Matlack } 5966ada51a9dSDavid Matlack 5967c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 5968c50d8ae3SPaolo Bonzini { 5969c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5970c50d8ae3SPaolo Bonzini 5971c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 5972fe5db27dSBen Gardon 5973fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 5974ada51a9dSDavid Matlack 5975ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 5976c50d8ae3SPaolo Bonzini } 5977c50d8ae3SPaolo Bonzini 597821fa3246SSean Christopherson static bool __kvm_zap_rmaps(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 597921fa3246SSean Christopherson { 598021fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 598121fa3246SSean Christopherson struct kvm_memslots *slots; 5982f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 598321fa3246SSean Christopherson bool flush = false; 598421fa3246SSean Christopherson gfn_t start, end; 5985f4209439SMaciej S. Szmigiero int i; 598621fa3246SSean Christopherson 598721fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 598821fa3246SSean Christopherson return flush; 598921fa3246SSean Christopherson 599021fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 599121fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 5992f4209439SMaciej S. Szmigiero 5993f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 5994f4209439SMaciej S. Szmigiero memslot = iter.slot; 599521fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 599621fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 5997f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 599821fa3246SSean Christopherson continue; 599921fa3246SSean Christopherson 600021fa3246SSean Christopherson flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, 60016ff94f27SDavid Matlack 600221fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 600321fa3246SSean Christopherson start, end - 1, true, flush); 600421fa3246SSean Christopherson } 600521fa3246SSean Christopherson } 600621fa3246SSean Christopherson 600721fa3246SSean Christopherson return flush; 600821fa3246SSean Christopherson } 600921fa3246SSean Christopherson 601088f58535SMaxim Levitsky /* 601188f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 601288f58535SMaxim Levitsky * (not including it) 601388f58535SMaxim Levitsky */ 6014c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6015c50d8ae3SPaolo Bonzini { 601621fa3246SSean Christopherson bool flush; 6017c50d8ae3SPaolo Bonzini int i; 6018c50d8ae3SPaolo Bonzini 6019f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6020f4209439SMaciej S. Szmigiero return; 6021f4209439SMaciej S. Szmigiero 6022531810caSBen Gardon write_lock(&kvm->mmu_lock); 60235a324c24SSean Christopherson 6024edb298c6SMaxim Levitsky kvm_inc_notifier_count(kvm, gfn_start, gfn_end); 6025edb298c6SMaxim Levitsky 602621fa3246SSean Christopherson flush = __kvm_zap_rmaps(kvm, gfn_start, gfn_end); 60276103bc07SBen Gardon 60286103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60296103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 6030f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 6031f47e5bbbSSean Christopherson gfn_end, true, flush); 60326103bc07SBen Gardon } 60335a324c24SSean Christopherson 60345a324c24SSean Christopherson if (flush) 6035bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 6036bc3b3c10SSean Christopherson gfn_end - gfn_start); 60375a324c24SSean Christopherson 6038edb298c6SMaxim Levitsky kvm_dec_notifier_count(kvm, gfn_start, gfn_end); 6039edb298c6SMaxim Levitsky 60405a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6041c50d8ae3SPaolo Bonzini } 6042c50d8ae3SPaolo Bonzini 6043c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 60440a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6045269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6046c50d8ae3SPaolo Bonzini { 60471346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6048c50d8ae3SPaolo Bonzini } 6049c50d8ae3SPaolo Bonzini 6050c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6051269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 60523c9bd400SJay Zhou int start_level) 6053c50d8ae3SPaolo Bonzini { 6054e2209710SBen Gardon bool flush = false; 6055c50d8ae3SPaolo Bonzini 6056e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6057531810caSBen Gardon write_lock(&kvm->mmu_lock); 60583c9bd400SJay Zhou flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, 6059e2209710SBen Gardon start_level, KVM_MAX_HUGEPAGE_LEVEL, 6060e2209710SBen Gardon false); 6061531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6062e2209710SBen Gardon } 6063c50d8ae3SPaolo Bonzini 606424ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 606524ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 606624ae4cfaSBen Gardon flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 606724ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 606824ae4cfaSBen Gardon } 606924ae4cfaSBen Gardon 6070c50d8ae3SPaolo Bonzini /* 60716ff94f27SDavid Matlack * Flush TLBs if any SPTEs had to be write-protected to ensure that 60726ff94f27SDavid Matlack * guest writes are reflected in the dirty bitmap before the memslot 60736ff94f27SDavid Matlack * update completes, i.e. before enabling dirty logging is visible to 60746ff94f27SDavid Matlack * userspace. 60756ff94f27SDavid Matlack * 60766ff94f27SDavid Matlack * Perform the TLB flush outside the mmu_lock to reduce the amount of 60776ff94f27SDavid Matlack * time the lock is held. However, this does mean that another CPU can 60786ff94f27SDavid Matlack * now grab mmu_lock and encounter a write-protected SPTE while CPUs 60796ff94f27SDavid Matlack * still have a writable mapping for the associated GFN in their TLB. 60806ff94f27SDavid Matlack * 60816ff94f27SDavid Matlack * This is safe but requires KVM to be careful when making decisions 60826ff94f27SDavid Matlack * based on the write-protection status of an SPTE. Specifically, KVM 60836ff94f27SDavid Matlack * also write-protects SPTEs to monitor changes to guest page tables 60846ff94f27SDavid Matlack * during shadow paging, and must guarantee no CPUs can write to those 60856ff94f27SDavid Matlack * page before the lock is dropped. As mentioned in the previous 60866ff94f27SDavid Matlack * paragraph, a write-protected SPTE is no guarantee that CPU cannot 60876ff94f27SDavid Matlack * perform writes. So to determine if a TLB flush is truly required, KVM 60886ff94f27SDavid Matlack * will clear a separate software-only bit (MMU-writable) and skip the 60896ff94f27SDavid Matlack * flush if-and-only-if this bit was already clear. 60906ff94f27SDavid Matlack * 609102844ac1SDavid Matlack * See is_writable_pte() for more details. 6092c50d8ae3SPaolo Bonzini */ 6093c50d8ae3SPaolo Bonzini if (flush) 60947f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6095c50d8ae3SPaolo Bonzini } 6096c50d8ae3SPaolo Bonzini 6097ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6098ada51a9dSDavid Matlack { 6099ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6100ada51a9dSDavid Matlack } 6101ada51a9dSDavid Matlack 6102ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6103ada51a9dSDavid Matlack { 6104ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6105ada51a9dSDavid Matlack return true; 6106ada51a9dSDavid Matlack 6107ada51a9dSDavid Matlack /* 6108ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6109ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6110ada51a9dSDavid Matlack * is possible but not worth the complexity. 6111ada51a9dSDavid Matlack */ 6112ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6113ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6114ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6115ada51a9dSDavid Matlack } 6116ada51a9dSDavid Matlack 6117ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6118ada51a9dSDavid Matlack { 6119ada51a9dSDavid Matlack int r; 6120ada51a9dSDavid Matlack 6121ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6122ada51a9dSDavid Matlack 6123ada51a9dSDavid Matlack /* 6124ada51a9dSDavid Matlack * Setting capacity == min would cause KVM to drop mmu_lock even if 6125ada51a9dSDavid Matlack * just one object was consumed from the cache, so make capacity 6126ada51a9dSDavid Matlack * larger than min. 6127ada51a9dSDavid Matlack */ 6128ada51a9dSDavid Matlack r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, 6129ada51a9dSDavid Matlack 2 * SPLIT_DESC_CACHE_MIN_NR_OBJECTS, 6130ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6131ada51a9dSDavid Matlack if (r) 6132ada51a9dSDavid Matlack return r; 6133ada51a9dSDavid Matlack 6134ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6135ada51a9dSDavid Matlack if (r) 6136ada51a9dSDavid Matlack return r; 6137ada51a9dSDavid Matlack 6138ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6139ada51a9dSDavid Matlack } 6140ada51a9dSDavid Matlack 6141ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6142ada51a9dSDavid Matlack { 6143ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6144ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6145ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6146ada51a9dSDavid Matlack unsigned int access; 6147ada51a9dSDavid Matlack gfn_t gfn; 6148ada51a9dSDavid Matlack 6149ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(huge_sp, huge_sptep - huge_sp->spt); 6150ada51a9dSDavid Matlack access = kvm_mmu_page_get_access(huge_sp, huge_sptep - huge_sp->spt); 6151ada51a9dSDavid Matlack 6152ada51a9dSDavid Matlack /* 6153ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6154ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6155ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6156ada51a9dSDavid Matlack * mapped with smaller pages. 6157ada51a9dSDavid Matlack */ 6158ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6159ada51a9dSDavid Matlack 6160ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6161ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6162ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6163ada51a9dSDavid Matlack 6164ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6165ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6166ada51a9dSDavid Matlack } 6167ada51a9dSDavid Matlack 6168ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6169ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6170ada51a9dSDavid Matlack u64 *huge_sptep) 6171ada51a9dSDavid Matlack 6172ada51a9dSDavid Matlack { 6173ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6174ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6175ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6176*03787394SPaolo Bonzini bool flush = false; 6177ada51a9dSDavid Matlack u64 *sptep, spte; 6178ada51a9dSDavid Matlack gfn_t gfn; 6179ada51a9dSDavid Matlack int index; 6180ada51a9dSDavid Matlack 6181ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6182ada51a9dSDavid Matlack 6183ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6184ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6185ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6186ada51a9dSDavid Matlack 6187ada51a9dSDavid Matlack /* 6188ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6189ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6190ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6191ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6192ada51a9dSDavid Matlack * modify them. 6193ada51a9dSDavid Matlack * 6194*03787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 6195*03787394SPaolo Bonzini * that lower level page table may only be partially populated. 6196*03787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 6197*03787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 6198*03787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 6199*03787394SPaolo Bonzini * fail to detect the need to flush. 6200ada51a9dSDavid Matlack */ 6201*03787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 6202*03787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6203ada51a9dSDavid Matlack continue; 6204*03787394SPaolo Bonzini } 6205ada51a9dSDavid Matlack 6206ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6207ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6208ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6209ada51a9dSDavid Matlack } 6210ada51a9dSDavid Matlack 6211*03787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6212ada51a9dSDavid Matlack } 6213ada51a9dSDavid Matlack 6214ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6215ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6216ada51a9dSDavid Matlack u64 *huge_sptep) 6217ada51a9dSDavid Matlack { 6218ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6219ada51a9dSDavid Matlack int level, r = 0; 6220ada51a9dSDavid Matlack gfn_t gfn; 6221ada51a9dSDavid Matlack u64 spte; 6222ada51a9dSDavid Matlack 6223ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 6224ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(huge_sp, huge_sptep - huge_sp->spt); 6225ada51a9dSDavid Matlack level = huge_sp->role.level; 6226ada51a9dSDavid Matlack spte = *huge_sptep; 6227ada51a9dSDavid Matlack 6228ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6229ada51a9dSDavid Matlack r = -ENOSPC; 6230ada51a9dSDavid Matlack goto out; 6231ada51a9dSDavid Matlack } 6232ada51a9dSDavid Matlack 6233ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6234ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6235ada51a9dSDavid Matlack cond_resched(); 6236ada51a9dSDavid Matlack /* 6237ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6238ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6239ada51a9dSDavid Matlack * dropped. 6240ada51a9dSDavid Matlack */ 6241ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6242ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6243ada51a9dSDavid Matlack goto out; 6244ada51a9dSDavid Matlack } 6245ada51a9dSDavid Matlack 6246ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6247ada51a9dSDavid Matlack 6248ada51a9dSDavid Matlack out: 6249ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6250ada51a9dSDavid Matlack return r; 6251ada51a9dSDavid Matlack } 6252ada51a9dSDavid Matlack 6253ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6254ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6255ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6256ada51a9dSDavid Matlack { 6257ada51a9dSDavid Matlack struct rmap_iterator iter; 6258ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6259ada51a9dSDavid Matlack u64 *huge_sptep; 6260ada51a9dSDavid Matlack int r; 6261ada51a9dSDavid Matlack 6262ada51a9dSDavid Matlack restart: 6263ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6264ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6265ada51a9dSDavid Matlack 6266ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6267ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6268ada51a9dSDavid Matlack continue; 6269ada51a9dSDavid Matlack 6270ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6271ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6272ada51a9dSDavid Matlack continue; 6273ada51a9dSDavid Matlack 6274ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6275ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6276ada51a9dSDavid Matlack continue; 6277ada51a9dSDavid Matlack 6278ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6279ada51a9dSDavid Matlack if (sp->role.invalid) 6280ada51a9dSDavid Matlack continue; 6281ada51a9dSDavid Matlack 6282ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6283ada51a9dSDavid Matlack 6284ada51a9dSDavid Matlack /* 6285ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6286ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6287ada51a9dSDavid Matlack * back into a consistent state. 6288ada51a9dSDavid Matlack */ 6289ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6290ada51a9dSDavid Matlack goto restart; 6291ada51a9dSDavid Matlack 6292ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6293ada51a9dSDavid Matlack break; 6294ada51a9dSDavid Matlack } 6295ada51a9dSDavid Matlack 6296ada51a9dSDavid Matlack return false; 6297ada51a9dSDavid Matlack } 6298ada51a9dSDavid Matlack 6299ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6300ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6301ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6302ada51a9dSDavid Matlack int target_level) 6303ada51a9dSDavid Matlack { 6304ada51a9dSDavid Matlack int level; 6305ada51a9dSDavid Matlack 6306ada51a9dSDavid Matlack /* 6307ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6308ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6309ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6310ada51a9dSDavid Matlack * already at the target level. 6311ada51a9dSDavid Matlack */ 6312ada51a9dSDavid Matlack for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) { 6313ada51a9dSDavid Matlack slot_handle_level_range(kvm, slot, shadow_mmu_try_split_huge_pages, 6314ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6315ada51a9dSDavid Matlack } 6316ada51a9dSDavid Matlack } 6317ada51a9dSDavid Matlack 6318cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6319cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6320cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6321cb00a70bSDavid Matlack u64 start, u64 end, 6322cb00a70bSDavid Matlack int target_level) 6323cb00a70bSDavid Matlack { 6324ada51a9dSDavid Matlack if (!is_tdp_mmu_enabled(kvm)) 6325ada51a9dSDavid Matlack return; 6326ada51a9dSDavid Matlack 6327ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6328ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6329ada51a9dSDavid Matlack 6330ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6331cb00a70bSDavid Matlack 6332cb00a70bSDavid Matlack /* 6333cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6334cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6335cb00a70bSDavid Matlack */ 6336cb00a70bSDavid Matlack } 6337cb00a70bSDavid Matlack 6338a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6339a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6340a3fe5dbdSDavid Matlack int target_level) 6341a3fe5dbdSDavid Matlack { 6342a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6343a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6344a3fe5dbdSDavid Matlack 6345ada51a9dSDavid Matlack if (!is_tdp_mmu_enabled(kvm)) 6346ada51a9dSDavid Matlack return; 6347ada51a9dSDavid Matlack 6348ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6349ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6350ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6351ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6352ada51a9dSDavid Matlack } 6353ada51a9dSDavid Matlack 6354a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6355cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6356a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6357a3fe5dbdSDavid Matlack 6358a3fe5dbdSDavid Matlack /* 6359a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6360a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6361a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6362a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6363a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6364a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6365a3fe5dbdSDavid Matlack * SPTEs. 6366a3fe5dbdSDavid Matlack */ 6367a3fe5dbdSDavid Matlack } 6368a3fe5dbdSDavid Matlack 6369c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 63700a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6371269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6372c50d8ae3SPaolo Bonzini { 6373c50d8ae3SPaolo Bonzini u64 *sptep; 6374c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6375c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6376c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 6377c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6378c50d8ae3SPaolo Bonzini 6379c50d8ae3SPaolo Bonzini restart: 6380c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 638157354682SSean Christopherson sp = sptep_to_sp(sptep); 6382c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(*sptep); 6383c50d8ae3SPaolo Bonzini 6384c50d8ae3SPaolo Bonzini /* 6385c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6386c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6387c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6388c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6389c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6390c50d8ae3SPaolo Bonzini */ 63915d49f08cSSean Christopherson if (sp->role.direct && 63929eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 63939eba50f8SSean Christopherson pfn, PG_LEVEL_NUM)) { 639471f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 6395c50d8ae3SPaolo Bonzini 6396c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6397c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6398c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6399c50d8ae3SPaolo Bonzini else 6400c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6401c50d8ae3SPaolo Bonzini 6402c50d8ae3SPaolo Bonzini goto restart; 6403c50d8ae3SPaolo Bonzini } 6404c50d8ae3SPaolo Bonzini } 6405c50d8ae3SPaolo Bonzini 6406c50d8ae3SPaolo Bonzini return need_tlb_flush; 6407c50d8ae3SPaolo Bonzini } 6408c50d8ae3SPaolo Bonzini 640920d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 641020d49186SDavid Matlack const struct kvm_memory_slot *slot) 641120d49186SDavid Matlack { 641220d49186SDavid Matlack /* 641320d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 641420d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 641520d49186SDavid Matlack */ 641620d49186SDavid Matlack if (slot_handle_level(kvm, slot, kvm_mmu_zap_collapsible_spte, 641720d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 641820d49186SDavid Matlack kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 641920d49186SDavid Matlack } 642020d49186SDavid Matlack 6421c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6422269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6423c50d8ae3SPaolo Bonzini { 6424e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6425531810caSBen Gardon write_lock(&kvm->mmu_lock); 642620d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6427531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6428e2209710SBen Gardon } 64292db6f772SBen Gardon 64302db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 64312db6f772SBen Gardon read_lock(&kvm->mmu_lock); 64324b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 64332db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 64342db6f772SBen Gardon } 6435c50d8ae3SPaolo Bonzini } 6436c50d8ae3SPaolo Bonzini 6437b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 64386c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6439b3594ffbSSean Christopherson { 6440b3594ffbSSean Christopherson /* 64417f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6442302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 64437f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 64447f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 64457f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6446b3594ffbSSean Christopherson */ 6447b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6448cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6449cec37648SSean Christopherson memslot->npages); 6450b3594ffbSSean Christopherson } 6451b3594ffbSSean Christopherson 6452c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6453269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6454c50d8ae3SPaolo Bonzini { 6455e2209710SBen Gardon bool flush = false; 6456c50d8ae3SPaolo Bonzini 6457e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6458531810caSBen Gardon write_lock(&kvm->mmu_lock); 6459610265eaSDavid Matlack /* 6460610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6461610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6462610265eaSDavid Matlack */ 6463610265eaSDavid Matlack flush = slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6464531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6465e2209710SBen Gardon } 6466c50d8ae3SPaolo Bonzini 646724ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 646824ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 646924ae4cfaSBen Gardon flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 647024ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 647124ae4cfaSBen Gardon } 647224ae4cfaSBen Gardon 6473c50d8ae3SPaolo Bonzini /* 6474c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6475c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6476c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6477c50d8ae3SPaolo Bonzini * dirty_bitmap. 6478c50d8ae3SPaolo Bonzini */ 6479c50d8ae3SPaolo Bonzini if (flush) 64807f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6481c50d8ae3SPaolo Bonzini } 6482c50d8ae3SPaolo Bonzini 6483c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6484c50d8ae3SPaolo Bonzini { 6485c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6486c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6487c50d8ae3SPaolo Bonzini int ign; 6488c50d8ae3SPaolo Bonzini 6489531810caSBen Gardon write_lock(&kvm->mmu_lock); 6490c50d8ae3SPaolo Bonzini restart: 6491c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6492f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6493c50d8ae3SPaolo Bonzini continue; 6494c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6495c50d8ae3SPaolo Bonzini goto restart; 6496531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6497c50d8ae3SPaolo Bonzini goto restart; 6498c50d8ae3SPaolo Bonzini } 6499c50d8ae3SPaolo Bonzini 6500c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6501faaf05b0SBen Gardon 6502897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6503faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6504faaf05b0SBen Gardon 6505531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6506c50d8ae3SPaolo Bonzini } 6507c50d8ae3SPaolo Bonzini 6508c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6509c50d8ae3SPaolo Bonzini { 6510c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6511c50d8ae3SPaolo Bonzini 6512c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6513c50d8ae3SPaolo Bonzini 6514c50d8ae3SPaolo Bonzini /* 6515c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6516c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6517c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6518c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6519c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6520c50d8ae3SPaolo Bonzini */ 6521c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6522c50d8ae3SPaolo Bonzini 6523c50d8ae3SPaolo Bonzini /* 6524c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6525c50d8ae3SPaolo Bonzini * zap all shadow pages. 6526c50d8ae3SPaolo Bonzini */ 6527c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6528c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6529c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6530c50d8ae3SPaolo Bonzini } 6531c50d8ae3SPaolo Bonzini } 6532c50d8ae3SPaolo Bonzini 6533c50d8ae3SPaolo Bonzini static unsigned long 6534c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6535c50d8ae3SPaolo Bonzini { 6536c50d8ae3SPaolo Bonzini struct kvm *kvm; 6537c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6538c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6539c50d8ae3SPaolo Bonzini 6540c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6541c50d8ae3SPaolo Bonzini 6542c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6543c50d8ae3SPaolo Bonzini int idx; 6544c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6545c50d8ae3SPaolo Bonzini 6546c50d8ae3SPaolo Bonzini /* 6547c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6548c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6549c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6550c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6551c50d8ae3SPaolo Bonzini */ 6552c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6553c50d8ae3SPaolo Bonzini break; 6554c50d8ae3SPaolo Bonzini /* 6555c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6556c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6557c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6558c50d8ae3SPaolo Bonzini * anyway. 6559c50d8ae3SPaolo Bonzini */ 6560c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6561c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6562c50d8ae3SPaolo Bonzini continue; 6563c50d8ae3SPaolo Bonzini 6564c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6565531810caSBen Gardon write_lock(&kvm->mmu_lock); 6566c50d8ae3SPaolo Bonzini 6567c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6568c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6569c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6570c50d8ae3SPaolo Bonzini goto unlock; 6571c50d8ae3SPaolo Bonzini } 6572c50d8ae3SPaolo Bonzini 6573ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6574c50d8ae3SPaolo Bonzini 6575c50d8ae3SPaolo Bonzini unlock: 6576531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6577c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6578c50d8ae3SPaolo Bonzini 6579c50d8ae3SPaolo Bonzini /* 6580c50d8ae3SPaolo Bonzini * unfair on small ones 6581c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6582c50d8ae3SPaolo Bonzini * sadness comes quickly 6583c50d8ae3SPaolo Bonzini */ 6584c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6585c50d8ae3SPaolo Bonzini break; 6586c50d8ae3SPaolo Bonzini } 6587c50d8ae3SPaolo Bonzini 6588c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6589c50d8ae3SPaolo Bonzini return freed; 6590c50d8ae3SPaolo Bonzini } 6591c50d8ae3SPaolo Bonzini 6592c50d8ae3SPaolo Bonzini static unsigned long 6593c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6594c50d8ae3SPaolo Bonzini { 6595c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6596c50d8ae3SPaolo Bonzini } 6597c50d8ae3SPaolo Bonzini 6598c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6599c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6600c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6601c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6602c50d8ae3SPaolo Bonzini }; 6603c50d8ae3SPaolo Bonzini 6604c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6605c50d8ae3SPaolo Bonzini { 6606c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6607c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6608c50d8ae3SPaolo Bonzini } 6609c50d8ae3SPaolo Bonzini 6610c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6611c50d8ae3SPaolo Bonzini { 6612c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6613c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6614c50d8ae3SPaolo Bonzini } 6615c50d8ae3SPaolo Bonzini 6616c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6617c50d8ae3SPaolo Bonzini { 6618c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6619c50d8ae3SPaolo Bonzini } 6620c50d8ae3SPaolo Bonzini 6621c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6622c50d8ae3SPaolo Bonzini { 6623c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6624c50d8ae3SPaolo Bonzini bool new_val; 6625c50d8ae3SPaolo Bonzini 6626c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6627c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6628c50d8ae3SPaolo Bonzini new_val = 0; 6629c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6630c50d8ae3SPaolo Bonzini new_val = 1; 6631c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6632c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6633c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6634c50d8ae3SPaolo Bonzini return -EINVAL; 6635c50d8ae3SPaolo Bonzini 6636c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6637c50d8ae3SPaolo Bonzini 6638c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6639c50d8ae3SPaolo Bonzini struct kvm *kvm; 6640c50d8ae3SPaolo Bonzini 6641c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6642c50d8ae3SPaolo Bonzini 6643c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6644c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6645c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6646c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6647c50d8ae3SPaolo Bonzini 6648c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6649c50d8ae3SPaolo Bonzini } 6650c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6651c50d8ae3SPaolo Bonzini } 6652c50d8ae3SPaolo Bonzini 6653c50d8ae3SPaolo Bonzini return 0; 6654c50d8ae3SPaolo Bonzini } 6655c50d8ae3SPaolo Bonzini 66561d0e8480SSean Christopherson /* 66571d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 66581d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 66591d0e8480SSean Christopherson */ 66601d0e8480SSean Christopherson void kvm_mmu_x86_module_init(void) 6661c50d8ae3SPaolo Bonzini { 6662c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6663c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 66641d0e8480SSean Christopherson } 66651d0e8480SSean Christopherson 66661d0e8480SSean Christopherson /* 66671d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 66681d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 66691d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 66701d0e8480SSean Christopherson */ 66711d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 66721d0e8480SSean Christopherson { 66731d0e8480SSean Christopherson int ret = -ENOMEM; 6674c50d8ae3SPaolo Bonzini 6675c50d8ae3SPaolo Bonzini /* 6676c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6677c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6678c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6679c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6680c50d8ae3SPaolo Bonzini */ 6681c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6682c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 66837a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6684c50d8ae3SPaolo Bonzini 6685c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6686c50d8ae3SPaolo Bonzini 6687c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6688c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6689c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6690c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6691c50d8ae3SPaolo Bonzini goto out; 6692c50d8ae3SPaolo Bonzini 6693c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6694c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6695c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6696c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6697c50d8ae3SPaolo Bonzini goto out; 6698c50d8ae3SPaolo Bonzini 6699c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6700c50d8ae3SPaolo Bonzini goto out; 6701c50d8ae3SPaolo Bonzini 6702c50d8ae3SPaolo Bonzini ret = register_shrinker(&mmu_shrinker); 6703c50d8ae3SPaolo Bonzini if (ret) 6704c50d8ae3SPaolo Bonzini goto out; 6705c50d8ae3SPaolo Bonzini 6706c50d8ae3SPaolo Bonzini return 0; 6707c50d8ae3SPaolo Bonzini 6708c50d8ae3SPaolo Bonzini out: 6709c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6710c50d8ae3SPaolo Bonzini return ret; 6711c50d8ae3SPaolo Bonzini } 6712c50d8ae3SPaolo Bonzini 6713c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6714c50d8ae3SPaolo Bonzini { 6715c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6716c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6717c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6718c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6719c50d8ae3SPaolo Bonzini } 6720c50d8ae3SPaolo Bonzini 67211d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6722c50d8ae3SPaolo Bonzini { 6723c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6724c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6725c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6726c50d8ae3SPaolo Bonzini } 6727c50d8ae3SPaolo Bonzini 6728f47491d7SSean Christopherson /* 6729f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6730f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6731f47491d7SSean Christopherson */ 6732f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6733f47491d7SSean Christopherson { 6734f47491d7SSean Christopherson /* 6735f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6736f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6737f47491d7SSean Christopherson */ 6738f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6739f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6740f47491d7SSean Christopherson 6741f47491d7SSean Christopherson if (!enabled || !ratio) 6742f47491d7SSean Christopherson return false; 6743f47491d7SSean Christopherson 6744f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6745f47491d7SSean Christopherson if (!*period) { 6746f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6747f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6748f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6749f47491d7SSean Christopherson } 6750f47491d7SSean Christopherson return true; 6751f47491d7SSean Christopherson } 6752f47491d7SSean Christopherson 67534dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6754c50d8ae3SPaolo Bonzini { 67554dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 67564dfe4f40SJunaid Shahid uint old_period, new_period; 6757c50d8ae3SPaolo Bonzini int err; 6758c50d8ae3SPaolo Bonzini 6759f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 67604dfe4f40SJunaid Shahid 6761c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6762c50d8ae3SPaolo Bonzini if (err) 6763c50d8ae3SPaolo Bonzini return err; 6764c50d8ae3SPaolo Bonzini 6765f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 67664dfe4f40SJunaid Shahid 6767f47491d7SSean Christopherson if (is_recovery_enabled && 67684dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6769c50d8ae3SPaolo Bonzini struct kvm *kvm; 6770c50d8ae3SPaolo Bonzini 6771c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6772c50d8ae3SPaolo Bonzini 6773c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6774c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6775c50d8ae3SPaolo Bonzini 6776c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6777c50d8ae3SPaolo Bonzini } 6778c50d8ae3SPaolo Bonzini 6779c50d8ae3SPaolo Bonzini return err; 6780c50d8ae3SPaolo Bonzini } 6781c50d8ae3SPaolo Bonzini 6782c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6783c50d8ae3SPaolo Bonzini { 6784ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6785c50d8ae3SPaolo Bonzini int rcu_idx; 6786c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6787c50d8ae3SPaolo Bonzini unsigned int ratio; 6788c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6789048f4980SSean Christopherson bool flush = false; 6790c50d8ae3SPaolo Bonzini ulong to_zap; 6791c50d8ae3SPaolo Bonzini 6792c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6793531810caSBen Gardon write_lock(&kvm->mmu_lock); 6794c50d8ae3SPaolo Bonzini 6795bb95dfb9SSean Christopherson /* 6796bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6797bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6798bb95dfb9SSean Christopherson * callback. 6799bb95dfb9SSean Christopherson */ 6800bb95dfb9SSean Christopherson rcu_read_lock(); 6801bb95dfb9SSean Christopherson 6802c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6803ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 68047d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 68057d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 68067d919c7aSSean Christopherson break; 68077d919c7aSSean Christopherson 6808c50d8ae3SPaolo Bonzini /* 6809c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6810c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6811c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6812c50d8ae3SPaolo Bonzini */ 6813c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6814c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6815c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6816c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6817897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6818315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 68198d1a182eSBen Gardon } else { 6820c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6821c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 682229cf0f50SBen Gardon } 6823c50d8ae3SPaolo Bonzini 6824531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6825048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6826bb95dfb9SSean Christopherson rcu_read_unlock(); 6827bb95dfb9SSean Christopherson 6828531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6829048f4980SSean Christopherson flush = false; 6830bb95dfb9SSean Christopherson 6831bb95dfb9SSean Christopherson rcu_read_lock(); 6832c50d8ae3SPaolo Bonzini } 6833c50d8ae3SPaolo Bonzini } 6834048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6835c50d8ae3SPaolo Bonzini 6836bb95dfb9SSean Christopherson rcu_read_unlock(); 6837bb95dfb9SSean Christopherson 6838531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6839c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6840c50d8ae3SPaolo Bonzini } 6841c50d8ae3SPaolo Bonzini 6842c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6843c50d8ae3SPaolo Bonzini { 6844f47491d7SSean Christopherson bool enabled; 6845f47491d7SSean Christopherson uint period; 68464dfe4f40SJunaid Shahid 6847f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 68484dfe4f40SJunaid Shahid 6849f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6850c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6851c50d8ae3SPaolo Bonzini } 6852c50d8ae3SPaolo Bonzini 6853c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6854c50d8ae3SPaolo Bonzini { 6855c50d8ae3SPaolo Bonzini u64 start_time; 6856c50d8ae3SPaolo Bonzini long remaining_time; 6857c50d8ae3SPaolo Bonzini 6858c50d8ae3SPaolo Bonzini while (true) { 6859c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6860c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6861c50d8ae3SPaolo Bonzini 6862c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6863c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6864c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6865c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6866c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6867c50d8ae3SPaolo Bonzini } 6868c50d8ae3SPaolo Bonzini 6869c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6870c50d8ae3SPaolo Bonzini 6871c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6872c50d8ae3SPaolo Bonzini return 0; 6873c50d8ae3SPaolo Bonzini 6874c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6875c50d8ae3SPaolo Bonzini } 6876c50d8ae3SPaolo Bonzini } 6877c50d8ae3SPaolo Bonzini 6878c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6879c50d8ae3SPaolo Bonzini { 6880c50d8ae3SPaolo Bonzini int err; 6881c50d8ae3SPaolo Bonzini 6882c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6883c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6884c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6885c50d8ae3SPaolo Bonzini if (!err) 6886c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6887c50d8ae3SPaolo Bonzini 6888c50d8ae3SPaolo Bonzini return err; 6889c50d8ae3SPaolo Bonzini } 6890c50d8ae3SPaolo Bonzini 6891c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6892c50d8ae3SPaolo Bonzini { 6893c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6894c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6895c50d8ae3SPaolo Bonzini } 6896