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 56fc9bf2e0SSean Christopherson #include "paging.h" 57fc9bf2e0SSean Christopherson 58c50d8ae3SPaolo Bonzini extern bool itlb_multihit_kvm_mitigation; 59c50d8ae3SPaolo Bonzini 60a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 614dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 62c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 63c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 64c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 65c50d8ae3SPaolo Bonzini #else 66c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 67c50d8ae3SPaolo Bonzini #endif 68c50d8ae3SPaolo Bonzini 69c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 704dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 71c50d8ae3SPaolo Bonzini 72d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 73c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 74c50d8ae3SPaolo Bonzini .get = param_get_bool, 75c50d8ae3SPaolo Bonzini }; 76c50d8ae3SPaolo Bonzini 774dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 784dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 79c50d8ae3SPaolo Bonzini .get = param_get_uint, 80c50d8ae3SPaolo Bonzini }; 81c50d8ae3SPaolo Bonzini 82c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 83c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 844dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 85c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 86c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 874dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 884dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 894dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 90c50d8ae3SPaolo Bonzini 9171fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9271fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9371fe7013SSean Christopherson 94c50d8ae3SPaolo Bonzini /* 95c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 96c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 97c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 98c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 99c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 100c50d8ae3SPaolo Bonzini */ 101c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 102c50d8ae3SPaolo Bonzini 1031d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 104746700d2SWei Huang static int tdp_root_level __read_mostly; 10583013059SSean Christopherson static int max_tdp_level __read_mostly; 106703c335dSSean Christopherson 107c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1085a9624afSPaolo Bonzini bool dbg = 0; 109c50d8ae3SPaolo Bonzini module_param(dbg, bool, 0644); 110c50d8ae3SPaolo Bonzini #endif 111c50d8ae3SPaolo Bonzini 112c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 113c50d8ae3SPaolo Bonzini 114c50d8ae3SPaolo Bonzini #define PT32_LEVEL_BITS 10 115c50d8ae3SPaolo Bonzini 116c50d8ae3SPaolo Bonzini #define PT32_LEVEL_SHIFT(level) \ 117c50d8ae3SPaolo Bonzini (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS) 118c50d8ae3SPaolo Bonzini 119c50d8ae3SPaolo Bonzini #define PT32_LVL_OFFSET_MASK(level) \ 120c50d8ae3SPaolo Bonzini (PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \ 121c50d8ae3SPaolo Bonzini * PT32_LEVEL_BITS))) - 1)) 122c50d8ae3SPaolo Bonzini 123c50d8ae3SPaolo Bonzini #define PT32_INDEX(address, level)\ 124c50d8ae3SPaolo Bonzini (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1)) 125c50d8ae3SPaolo Bonzini 126c50d8ae3SPaolo Bonzini 127c50d8ae3SPaolo Bonzini #define PT32_BASE_ADDR_MASK PAGE_MASK 128c50d8ae3SPaolo Bonzini #define PT32_DIR_BASE_ADDR_MASK \ 129c50d8ae3SPaolo Bonzini (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1)) 130c50d8ae3SPaolo Bonzini #define PT32_LVL_ADDR_MASK(level) \ 131c50d8ae3SPaolo Bonzini (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \ 132c50d8ae3SPaolo Bonzini * PT32_LEVEL_BITS))) - 1)) 133c50d8ae3SPaolo Bonzini 134c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 135c50d8ae3SPaolo Bonzini 136dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 13713236e25SPeter Xu #define PTE_LIST_EXT 14 138c50d8ae3SPaolo Bonzini 13913236e25SPeter Xu /* 14013236e25SPeter Xu * Slight optimization of cacheline layout, by putting `more' and `spte_count' 14113236e25SPeter Xu * at the start; then accessing it will only use one single cacheline for 14213236e25SPeter Xu * either full (entries==PTE_LIST_EXT) case or entries<=6. 14313236e25SPeter Xu */ 144c50d8ae3SPaolo Bonzini struct pte_list_desc { 145c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 14613236e25SPeter Xu /* 14713236e25SPeter Xu * Stores number of entries stored in the pte_list_desc. No need to be 14813236e25SPeter Xu * u64 but just for easier alignment. When PTE_LIST_EXT, means full. 14913236e25SPeter Xu */ 15013236e25SPeter Xu u64 spte_count; 15113236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 152c50d8ae3SPaolo Bonzini }; 153c50d8ae3SPaolo Bonzini 154c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 155c50d8ae3SPaolo Bonzini u64 addr; 156c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 157c50d8ae3SPaolo Bonzini u64 *sptep; 158c50d8ae3SPaolo Bonzini int level; 159c50d8ae3SPaolo Bonzini unsigned index; 160c50d8ae3SPaolo Bonzini }; 161c50d8ae3SPaolo Bonzini 162c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 163c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 164c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 165c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 166c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 167c50d8ae3SPaolo Bonzini 168c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 169c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 170c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 171c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 172c50d8ae3SPaolo Bonzini 173c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 174c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 175c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 176c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 177c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 178c50d8ae3SPaolo Bonzini 179c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 18002c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 181c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 182c50d8ae3SPaolo Bonzini 183c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 184c50d8ae3SPaolo Bonzini 185594e91a1SSean Christopherson struct kvm_mmu_role_regs { 186594e91a1SSean Christopherson const unsigned long cr0; 187594e91a1SSean Christopherson const unsigned long cr4; 188594e91a1SSean Christopherson const u64 efer; 189594e91a1SSean Christopherson }; 190594e91a1SSean Christopherson 191c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 192c50d8ae3SPaolo Bonzini #include "mmutrace.h" 193c50d8ae3SPaolo Bonzini 194594e91a1SSean Christopherson /* 195594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1967a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 197594e91a1SSean Christopherson * the single source of truth for the MMU's state. 198594e91a1SSean Christopherson */ 199594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 20082ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 20182ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 202594e91a1SSean Christopherson { \ 203594e91a1SSean Christopherson return !!(regs->reg & flag); \ 204594e91a1SSean Christopherson } 205594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 206594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 207594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 208594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 209594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 210594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 211594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 212594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 213594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 214594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 215594e91a1SSean Christopherson 21660667724SSean Christopherson /* 21760667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 21860667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 21960667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 22060667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 22160667724SSean Christopherson */ 22260667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2234ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 22460667724SSean Christopherson { \ 225e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 22660667724SSean Christopherson } 22760667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 22860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 22960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 23060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 23160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 23260667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 23360667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 23456b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 23560667724SSean Christopherson 236faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 237faf72962SPaolo Bonzini { 238faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 239faf72962SPaolo Bonzini } 240faf72962SPaolo Bonzini 241faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 242faf72962SPaolo Bonzini { 243faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 244faf72962SPaolo Bonzini } 245faf72962SPaolo Bonzini 246594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 247594e91a1SSean Christopherson { 248594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 249594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 250594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 251594e91a1SSean Christopherson .efer = vcpu->arch.efer, 252594e91a1SSean Christopherson }; 253594e91a1SSean Christopherson 254594e91a1SSean Christopherson return regs; 255594e91a1SSean Christopherson } 256c50d8ae3SPaolo Bonzini 257c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 258c50d8ae3SPaolo Bonzini { 259afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 260c50d8ae3SPaolo Bonzini } 261c50d8ae3SPaolo Bonzini 262c50d8ae3SPaolo Bonzini static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm, 263c50d8ae3SPaolo Bonzini struct kvm_tlb_range *range) 264c50d8ae3SPaolo Bonzini { 265c50d8ae3SPaolo Bonzini int ret = -ENOTSUPP; 266c50d8ae3SPaolo Bonzini 267afaf0b2fSSean Christopherson if (range && kvm_x86_ops.tlb_remote_flush_with_range) 268b3646477SJason Baron ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range); 269c50d8ae3SPaolo Bonzini 270c50d8ae3SPaolo Bonzini if (ret) 271c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 272c50d8ae3SPaolo Bonzini } 273c50d8ae3SPaolo Bonzini 2742f2fad08SBen Gardon void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 275c50d8ae3SPaolo Bonzini u64 start_gfn, u64 pages) 276c50d8ae3SPaolo Bonzini { 277c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 278c50d8ae3SPaolo Bonzini 279c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 280c50d8ae3SPaolo Bonzini range.pages = pages; 281c50d8ae3SPaolo Bonzini 282c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_range(kvm, &range); 283c50d8ae3SPaolo Bonzini } 284c50d8ae3SPaolo Bonzini 2858f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2868f79b064SBen Gardon unsigned int access) 2878f79b064SBen Gardon { 288c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2898f79b064SBen Gardon 290c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 291c236d962SSean Christopherson mmu_spte_set(sptep, spte); 292c50d8ae3SPaolo Bonzini } 293c50d8ae3SPaolo Bonzini 294c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 295c50d8ae3SPaolo Bonzini { 296c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 297c50d8ae3SPaolo Bonzini 2988a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 299c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 300c50d8ae3SPaolo Bonzini 301c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 302c50d8ae3SPaolo Bonzini } 303c50d8ae3SPaolo Bonzini 304c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 305c50d8ae3SPaolo Bonzini { 306c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 307c50d8ae3SPaolo Bonzini } 308c50d8ae3SPaolo Bonzini 309c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 310c50d8ae3SPaolo Bonzini { 311c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 312c50d8ae3SPaolo Bonzini 313c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 314c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 315c50d8ae3SPaolo Bonzini return false; 316c50d8ae3SPaolo Bonzini 317c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 318c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 319c50d8ae3SPaolo Bonzini 320c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 321c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 322c50d8ae3SPaolo Bonzini } 323c50d8ae3SPaolo Bonzini 324c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 325c50d8ae3SPaolo Bonzini { 326c50d8ae3SPaolo Bonzini return 1; 327c50d8ae3SPaolo Bonzini } 328c50d8ae3SPaolo Bonzini 329c50d8ae3SPaolo Bonzini static gfn_t pse36_gfn_delta(u32 gpte) 330c50d8ae3SPaolo Bonzini { 331c50d8ae3SPaolo Bonzini int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT; 332c50d8ae3SPaolo Bonzini 333c50d8ae3SPaolo Bonzini return (gpte & PT32_DIR_PSE36_MASK) << shift; 334c50d8ae3SPaolo Bonzini } 335c50d8ae3SPaolo Bonzini 336c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 337c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 338c50d8ae3SPaolo Bonzini { 339c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 340c50d8ae3SPaolo Bonzini } 341c50d8ae3SPaolo Bonzini 342c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 343c50d8ae3SPaolo Bonzini { 344c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 345c50d8ae3SPaolo Bonzini } 346c50d8ae3SPaolo Bonzini 347c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 348c50d8ae3SPaolo Bonzini { 349c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 350c50d8ae3SPaolo Bonzini } 351c50d8ae3SPaolo Bonzini 352c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 353c50d8ae3SPaolo Bonzini { 354c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 355c50d8ae3SPaolo Bonzini } 356c50d8ae3SPaolo Bonzini #else 357c50d8ae3SPaolo Bonzini union split_spte { 358c50d8ae3SPaolo Bonzini struct { 359c50d8ae3SPaolo Bonzini u32 spte_low; 360c50d8ae3SPaolo Bonzini u32 spte_high; 361c50d8ae3SPaolo Bonzini }; 362c50d8ae3SPaolo Bonzini u64 spte; 363c50d8ae3SPaolo Bonzini }; 364c50d8ae3SPaolo Bonzini 365c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 366c50d8ae3SPaolo Bonzini { 36757354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 368c50d8ae3SPaolo Bonzini 369c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 370c50d8ae3SPaolo Bonzini return; 371c50d8ae3SPaolo Bonzini 372c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 373c50d8ae3SPaolo Bonzini smp_wmb(); 374c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 375c50d8ae3SPaolo Bonzini } 376c50d8ae3SPaolo Bonzini 377c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 378c50d8ae3SPaolo Bonzini { 379c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 380c50d8ae3SPaolo Bonzini 381c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 382c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 383c50d8ae3SPaolo Bonzini 384c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 385c50d8ae3SPaolo Bonzini 386c50d8ae3SPaolo Bonzini /* 387c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 388c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 389c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 390c50d8ae3SPaolo Bonzini */ 391c50d8ae3SPaolo Bonzini smp_wmb(); 392c50d8ae3SPaolo Bonzini 393c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 394c50d8ae3SPaolo Bonzini } 395c50d8ae3SPaolo Bonzini 396c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 397c50d8ae3SPaolo Bonzini { 398c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 399c50d8ae3SPaolo Bonzini 400c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 401c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 402c50d8ae3SPaolo Bonzini 403c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 404c50d8ae3SPaolo Bonzini 405c50d8ae3SPaolo Bonzini /* 406c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 407c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 408c50d8ae3SPaolo Bonzini */ 409c50d8ae3SPaolo Bonzini smp_wmb(); 410c50d8ae3SPaolo Bonzini 411c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 412c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 413c50d8ae3SPaolo Bonzini } 414c50d8ae3SPaolo Bonzini 415c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 416c50d8ae3SPaolo Bonzini { 417c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 418c50d8ae3SPaolo Bonzini 419c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 420c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 421c50d8ae3SPaolo Bonzini 422c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 423c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 424c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 425c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 426c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 427c50d8ae3SPaolo Bonzini 428c50d8ae3SPaolo Bonzini return orig.spte; 429c50d8ae3SPaolo Bonzini } 430c50d8ae3SPaolo Bonzini 431c50d8ae3SPaolo Bonzini /* 432c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 433c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 434c50d8ae3SPaolo Bonzini * 435c50d8ae3SPaolo Bonzini * An spte tlb flush may be pending, because kvm_set_pte_rmapp 436c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 437c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 438c50d8ae3SPaolo Bonzini * 439c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 440c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 441c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 442c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 443c50d8ae3SPaolo Bonzini * 444c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 445c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 446c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 447c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 448c50d8ae3SPaolo Bonzini */ 449c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 450c50d8ae3SPaolo Bonzini { 45157354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 452c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 453c50d8ae3SPaolo Bonzini int count; 454c50d8ae3SPaolo Bonzini 455c50d8ae3SPaolo Bonzini retry: 456c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 457c50d8ae3SPaolo Bonzini smp_rmb(); 458c50d8ae3SPaolo Bonzini 459c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 460c50d8ae3SPaolo Bonzini smp_rmb(); 461c50d8ae3SPaolo Bonzini 462c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 463c50d8ae3SPaolo Bonzini smp_rmb(); 464c50d8ae3SPaolo Bonzini 465c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 466c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 467c50d8ae3SPaolo Bonzini goto retry; 468c50d8ae3SPaolo Bonzini 469c50d8ae3SPaolo Bonzini return spte.spte; 470c50d8ae3SPaolo Bonzini } 471c50d8ae3SPaolo Bonzini #endif 472c50d8ae3SPaolo Bonzini 473c50d8ae3SPaolo Bonzini static bool spte_has_volatile_bits(u64 spte) 474c50d8ae3SPaolo Bonzini { 475c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(spte)) 476c50d8ae3SPaolo Bonzini return false; 477c50d8ae3SPaolo Bonzini 478c50d8ae3SPaolo Bonzini /* 479c50d8ae3SPaolo Bonzini * Always atomically update spte if it can be updated 480c50d8ae3SPaolo Bonzini * out of mmu-lock, it can ensure dirty bit is not lost, 481c50d8ae3SPaolo Bonzini * also, it can help us to get a stable is_writable_pte() 482c50d8ae3SPaolo Bonzini * to ensure tlb flush is not missed. 483c50d8ae3SPaolo Bonzini */ 484c50d8ae3SPaolo Bonzini if (spte_can_locklessly_be_made_writable(spte) || 485c50d8ae3SPaolo Bonzini is_access_track_spte(spte)) 486c50d8ae3SPaolo Bonzini return true; 487c50d8ae3SPaolo Bonzini 488c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 489c50d8ae3SPaolo Bonzini if ((spte & shadow_accessed_mask) == 0 || 490c50d8ae3SPaolo Bonzini (is_writable_pte(spte) && (spte & shadow_dirty_mask) == 0)) 491c50d8ae3SPaolo Bonzini return true; 492c50d8ae3SPaolo Bonzini } 493c50d8ae3SPaolo Bonzini 494c50d8ae3SPaolo Bonzini return false; 495c50d8ae3SPaolo Bonzini } 496c50d8ae3SPaolo Bonzini 497c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 498c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 499c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 500c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 501c50d8ae3SPaolo Bonzini * the spte. 502c50d8ae3SPaolo Bonzini */ 503c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 504c50d8ae3SPaolo Bonzini { 505c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 506c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 507c50d8ae3SPaolo Bonzini } 508c50d8ae3SPaolo Bonzini 509c50d8ae3SPaolo Bonzini /* 510c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 511c50d8ae3SPaolo Bonzini * accessed/dirty status. 512c50d8ae3SPaolo Bonzini */ 513c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 514c50d8ae3SPaolo Bonzini { 515c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 516c50d8ae3SPaolo Bonzini 517c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 518115111efSDavid Matlack check_spte_writable_invariants(new_spte); 519c50d8ae3SPaolo Bonzini 520c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 521c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 522c50d8ae3SPaolo Bonzini return old_spte; 523c50d8ae3SPaolo Bonzini } 524c50d8ae3SPaolo Bonzini 525c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 526c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 527c50d8ae3SPaolo Bonzini else 528c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 529c50d8ae3SPaolo Bonzini 530c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 531c50d8ae3SPaolo Bonzini 532c50d8ae3SPaolo Bonzini return old_spte; 533c50d8ae3SPaolo Bonzini } 534c50d8ae3SPaolo Bonzini 535c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 536c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 537c50d8ae3SPaolo Bonzini * 53802844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 53902844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 54002844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 541c50d8ae3SPaolo Bonzini * 542c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 543c50d8ae3SPaolo Bonzini */ 544c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 545c50d8ae3SPaolo Bonzini { 546c50d8ae3SPaolo Bonzini bool flush = false; 547c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 548c50d8ae3SPaolo Bonzini 549c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 550c50d8ae3SPaolo Bonzini return false; 551c50d8ae3SPaolo Bonzini 552c50d8ae3SPaolo Bonzini /* 553c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 554c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 555c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 556c50d8ae3SPaolo Bonzini */ 557c50d8ae3SPaolo Bonzini if (spte_can_locklessly_be_made_writable(old_spte) && 558c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 559c50d8ae3SPaolo Bonzini flush = true; 560c50d8ae3SPaolo Bonzini 561c50d8ae3SPaolo Bonzini /* 562c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 563c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 564c50d8ae3SPaolo Bonzini */ 565c50d8ae3SPaolo Bonzini 566c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 567c50d8ae3SPaolo Bonzini flush = true; 568c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 569c50d8ae3SPaolo Bonzini } 570c50d8ae3SPaolo Bonzini 571c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 572c50d8ae3SPaolo Bonzini flush = true; 573c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 574c50d8ae3SPaolo Bonzini } 575c50d8ae3SPaolo Bonzini 576c50d8ae3SPaolo Bonzini return flush; 577c50d8ae3SPaolo Bonzini } 578c50d8ae3SPaolo Bonzini 579c50d8ae3SPaolo Bonzini /* 580c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 581c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 582c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5837fa2a347SSean Christopherson * Returns the old PTE. 584c50d8ae3SPaolo Bonzini */ 58571f51d2cSMingwei Zhang static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 586c50d8ae3SPaolo Bonzini { 587c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 588c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 58971f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 590c50d8ae3SPaolo Bonzini 591c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 592c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 593c50d8ae3SPaolo Bonzini else 594c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 595c50d8ae3SPaolo Bonzini 596c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5977fa2a347SSean Christopherson return old_spte; 598c50d8ae3SPaolo Bonzini 59971f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 60071f51d2cSMingwei Zhang 601c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 602c50d8ae3SPaolo Bonzini 603c50d8ae3SPaolo Bonzini /* 604c50d8ae3SPaolo Bonzini * KVM does not hold the refcount of the page used by 605c50d8ae3SPaolo Bonzini * kvm mmu, before reclaiming the page, we should 606c50d8ae3SPaolo Bonzini * unmap it from mmu first. 607c50d8ae3SPaolo Bonzini */ 608c50d8ae3SPaolo Bonzini WARN_ON(!kvm_is_reserved_pfn(pfn) && !page_count(pfn_to_page(pfn))); 609c50d8ae3SPaolo Bonzini 610c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 611c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 612c50d8ae3SPaolo Bonzini 613c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 614c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 615c50d8ae3SPaolo Bonzini 6167fa2a347SSean Christopherson return old_spte; 617c50d8ae3SPaolo Bonzini } 618c50d8ae3SPaolo Bonzini 619c50d8ae3SPaolo Bonzini /* 620c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 621c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 622c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 623c50d8ae3SPaolo Bonzini */ 624c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 625c50d8ae3SPaolo Bonzini { 626c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 627c50d8ae3SPaolo Bonzini } 628c50d8ae3SPaolo Bonzini 629c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 630c50d8ae3SPaolo Bonzini { 631c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 632c50d8ae3SPaolo Bonzini } 633c50d8ae3SPaolo Bonzini 634c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 635c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 636c50d8ae3SPaolo Bonzini { 637c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 638c50d8ae3SPaolo Bonzini 639c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 640c50d8ae3SPaolo Bonzini return false; 641c50d8ae3SPaolo Bonzini 642c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 643c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 644c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 645c50d8ae3SPaolo Bonzini } else { 646c50d8ae3SPaolo Bonzini /* 647c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 648c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 649c50d8ae3SPaolo Bonzini */ 650c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 651c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 652c50d8ae3SPaolo Bonzini 653c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 654c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 655c50d8ae3SPaolo Bonzini } 656c50d8ae3SPaolo Bonzini 657c50d8ae3SPaolo Bonzini return true; 658c50d8ae3SPaolo Bonzini } 659c50d8ae3SPaolo Bonzini 660c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 661c50d8ae3SPaolo Bonzini { 662c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 663c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 664c5c8c7c5SDavid Matlack } else { 665c50d8ae3SPaolo Bonzini /* 666c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 667c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 668c50d8ae3SPaolo Bonzini */ 669c50d8ae3SPaolo Bonzini local_irq_disable(); 670c50d8ae3SPaolo Bonzini 671c50d8ae3SPaolo Bonzini /* 672c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 673c50d8ae3SPaolo Bonzini * to vcpu->mode. 674c50d8ae3SPaolo Bonzini */ 675c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 676c50d8ae3SPaolo Bonzini } 677c5c8c7c5SDavid Matlack } 678c50d8ae3SPaolo Bonzini 679c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 680c50d8ae3SPaolo Bonzini { 681c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 682c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 683c5c8c7c5SDavid Matlack } else { 684c50d8ae3SPaolo Bonzini /* 685c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 686c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 687c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 688c50d8ae3SPaolo Bonzini */ 689c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 690c50d8ae3SPaolo Bonzini local_irq_enable(); 691c50d8ae3SPaolo Bonzini } 692c5c8c7c5SDavid Matlack } 693c50d8ae3SPaolo Bonzini 694378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 695c50d8ae3SPaolo Bonzini { 696c50d8ae3SPaolo Bonzini int r; 697c50d8ae3SPaolo Bonzini 698531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 69994ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 700531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 701c50d8ae3SPaolo Bonzini if (r) 702c50d8ae3SPaolo Bonzini return r; 70394ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 704171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 705171a90d7SSean Christopherson if (r) 706171a90d7SSean Christopherson return r; 707378f5cd6SSean Christopherson if (maybe_indirect) { 70894ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_cache, 709171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 710c50d8ae3SPaolo Bonzini if (r) 711c50d8ae3SPaolo Bonzini return r; 712378f5cd6SSean Christopherson } 71394ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 714531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 715c50d8ae3SPaolo Bonzini } 716c50d8ae3SPaolo Bonzini 717c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 718c50d8ae3SPaolo Bonzini { 71994ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 72094ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 72194ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_gfn_array_cache); 72294ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 723c50d8ae3SPaolo Bonzini } 724c50d8ae3SPaolo Bonzini 725c50d8ae3SPaolo Bonzini static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu) 726c50d8ae3SPaolo Bonzini { 72794ce87efSSean Christopherson return kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_list_desc_cache); 728c50d8ae3SPaolo Bonzini } 729c50d8ae3SPaolo Bonzini 730c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 731c50d8ae3SPaolo Bonzini { 732c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 733c50d8ae3SPaolo Bonzini } 734c50d8ae3SPaolo Bonzini 735c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 736c50d8ae3SPaolo Bonzini { 737c50d8ae3SPaolo Bonzini if (!sp->role.direct) 738c50d8ae3SPaolo Bonzini return sp->gfns[index]; 739c50d8ae3SPaolo Bonzini 740c50d8ae3SPaolo Bonzini return sp->gfn + (index << ((sp->role.level - 1) * PT64_LEVEL_BITS)); 741c50d8ae3SPaolo Bonzini } 742c50d8ae3SPaolo Bonzini 743c50d8ae3SPaolo Bonzini static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn) 744c50d8ae3SPaolo Bonzini { 745c50d8ae3SPaolo Bonzini if (!sp->role.direct) { 746c50d8ae3SPaolo Bonzini sp->gfns[index] = gfn; 747c50d8ae3SPaolo Bonzini return; 748c50d8ae3SPaolo Bonzini } 749c50d8ae3SPaolo Bonzini 750c50d8ae3SPaolo Bonzini if (WARN_ON(gfn != kvm_mmu_page_get_gfn(sp, index))) 751c50d8ae3SPaolo Bonzini pr_err_ratelimited("gfn mismatch under direct page %llx " 752c50d8ae3SPaolo Bonzini "(expected %llx, got %llx)\n", 753c50d8ae3SPaolo Bonzini sp->gfn, 754c50d8ae3SPaolo Bonzini kvm_mmu_page_get_gfn(sp, index), gfn); 755c50d8ae3SPaolo Bonzini } 756c50d8ae3SPaolo Bonzini 757c50d8ae3SPaolo Bonzini /* 758c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 759c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 760c50d8ae3SPaolo Bonzini */ 761c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7628ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 763c50d8ae3SPaolo Bonzini { 764c50d8ae3SPaolo Bonzini unsigned long idx; 765c50d8ae3SPaolo Bonzini 766c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 767c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 768c50d8ae3SPaolo Bonzini } 769c50d8ae3SPaolo Bonzini 770269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 771c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 772c50d8ae3SPaolo Bonzini { 773c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 774c50d8ae3SPaolo Bonzini int i; 775c50d8ae3SPaolo Bonzini 7763bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 777c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 778c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 779c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 780c50d8ae3SPaolo Bonzini } 781c50d8ae3SPaolo Bonzini } 782c50d8ae3SPaolo Bonzini 783269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 784c50d8ae3SPaolo Bonzini { 785c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 786c50d8ae3SPaolo Bonzini } 787c50d8ae3SPaolo Bonzini 788269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 789c50d8ae3SPaolo Bonzini { 790c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 791c50d8ae3SPaolo Bonzini } 792c50d8ae3SPaolo Bonzini 793c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 794c50d8ae3SPaolo Bonzini { 795c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 796c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 797c50d8ae3SPaolo Bonzini gfn_t gfn; 798c50d8ae3SPaolo Bonzini 799c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 800c50d8ae3SPaolo Bonzini gfn = sp->gfn; 801c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 802c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 803c50d8ae3SPaolo Bonzini 804c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8053bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 806c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 807c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 808c50d8ae3SPaolo Bonzini 809c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 810c50d8ae3SPaolo Bonzini } 811c50d8ae3SPaolo Bonzini 81229cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 813c50d8ae3SPaolo Bonzini { 814c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 815c50d8ae3SPaolo Bonzini return; 816c50d8ae3SPaolo Bonzini 817c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 818c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 819c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 820c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 821c50d8ae3SPaolo Bonzini } 822c50d8ae3SPaolo Bonzini 823c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 824c50d8ae3SPaolo Bonzini { 825c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 826c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 827c50d8ae3SPaolo Bonzini gfn_t gfn; 828c50d8ae3SPaolo Bonzini 829c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 830c50d8ae3SPaolo Bonzini gfn = sp->gfn; 831c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 832c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8333bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 834c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 835c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 836c50d8ae3SPaolo Bonzini 837c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 838c50d8ae3SPaolo Bonzini } 839c50d8ae3SPaolo Bonzini 84029cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 841c50d8ae3SPaolo Bonzini { 842c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 843c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 844c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 845c50d8ae3SPaolo Bonzini } 846c50d8ae3SPaolo Bonzini 847c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 848c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 849c50d8ae3SPaolo Bonzini bool no_dirty_log) 850c50d8ae3SPaolo Bonzini { 851c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 852c50d8ae3SPaolo Bonzini 853c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 85491b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 85591b0d268SPaolo Bonzini return NULL; 856044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 85791b0d268SPaolo Bonzini return NULL; 858c50d8ae3SPaolo Bonzini 859c50d8ae3SPaolo Bonzini return slot; 860c50d8ae3SPaolo Bonzini } 861c50d8ae3SPaolo Bonzini 862c50d8ae3SPaolo Bonzini /* 863c50d8ae3SPaolo Bonzini * About rmap_head encoding: 864c50d8ae3SPaolo Bonzini * 865c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 866c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 867c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 868c50d8ae3SPaolo Bonzini */ 869c50d8ae3SPaolo Bonzini 870c50d8ae3SPaolo Bonzini /* 871c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 872c50d8ae3SPaolo Bonzini */ 873c50d8ae3SPaolo Bonzini static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte, 874c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 875c50d8ae3SPaolo Bonzini { 876c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 87713236e25SPeter Xu int count = 0; 878c50d8ae3SPaolo Bonzini 879c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 880805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 881c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 882c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 883805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 884c50d8ae3SPaolo Bonzini desc = mmu_alloc_pte_list_desc(vcpu); 885c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 886c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 88713236e25SPeter Xu desc->spte_count = 2; 888c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 889c50d8ae3SPaolo Bonzini ++count; 890c50d8ae3SPaolo Bonzini } else { 891805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 892c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 89313236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 894c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 895c6c4f961SLi RongQing if (!desc->more) { 896c50d8ae3SPaolo Bonzini desc->more = mmu_alloc_pte_list_desc(vcpu); 897c50d8ae3SPaolo Bonzini desc = desc->more; 89813236e25SPeter Xu desc->spte_count = 0; 899c6c4f961SLi RongQing break; 900c6c4f961SLi RongQing } 901c6c4f961SLi RongQing desc = desc->more; 902c50d8ae3SPaolo Bonzini } 90313236e25SPeter Xu count += desc->spte_count; 90413236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 905c50d8ae3SPaolo Bonzini } 906c50d8ae3SPaolo Bonzini return count; 907c50d8ae3SPaolo Bonzini } 908c50d8ae3SPaolo Bonzini 909c50d8ae3SPaolo Bonzini static void 910c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 911c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 912c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 913c50d8ae3SPaolo Bonzini { 91413236e25SPeter Xu int j = desc->spte_count - 1; 915c50d8ae3SPaolo Bonzini 916c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 917c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 91813236e25SPeter Xu desc->spte_count--; 91913236e25SPeter Xu if (desc->spte_count) 920c50d8ae3SPaolo Bonzini return; 921c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 922fe3c2b4cSMiaohe Lin rmap_head->val = 0; 923c50d8ae3SPaolo Bonzini else 924c50d8ae3SPaolo Bonzini if (prev_desc) 925c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 926c50d8ae3SPaolo Bonzini else 927c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 928c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 929c50d8ae3SPaolo Bonzini } 930c50d8ae3SPaolo Bonzini 931c50d8ae3SPaolo Bonzini static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 932c50d8ae3SPaolo Bonzini { 933c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 934c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 935c50d8ae3SPaolo Bonzini int i; 936c50d8ae3SPaolo Bonzini 937c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 938c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 939c50d8ae3SPaolo Bonzini BUG(); 940c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 941805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 942c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 943c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 944c50d8ae3SPaolo Bonzini BUG(); 945c50d8ae3SPaolo Bonzini } 946c50d8ae3SPaolo Bonzini rmap_head->val = 0; 947c50d8ae3SPaolo Bonzini } else { 948805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 949c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 950c50d8ae3SPaolo Bonzini prev_desc = NULL; 951c50d8ae3SPaolo Bonzini while (desc) { 95213236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 953c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 954c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 955c50d8ae3SPaolo Bonzini desc, i, prev_desc); 956c50d8ae3SPaolo Bonzini return; 957c50d8ae3SPaolo Bonzini } 958c50d8ae3SPaolo Bonzini } 959c50d8ae3SPaolo Bonzini prev_desc = desc; 960c50d8ae3SPaolo Bonzini desc = desc->more; 961c50d8ae3SPaolo Bonzini } 962c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 963c50d8ae3SPaolo Bonzini BUG(); 964c50d8ae3SPaolo Bonzini } 965c50d8ae3SPaolo Bonzini } 966c50d8ae3SPaolo Bonzini 96771f51d2cSMingwei Zhang static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 96871f51d2cSMingwei Zhang u64 *sptep) 969c50d8ae3SPaolo Bonzini { 97071f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 971c50d8ae3SPaolo Bonzini __pte_list_remove(sptep, rmap_head); 972c50d8ae3SPaolo Bonzini } 973c50d8ae3SPaolo Bonzini 974a75b5404SPeter Xu /* Return true if rmap existed, false otherwise */ 97571f51d2cSMingwei Zhang static bool pte_list_destroy(struct kvm *kvm, struct kvm_rmap_head *rmap_head) 976a75b5404SPeter Xu { 977a75b5404SPeter Xu struct pte_list_desc *desc, *next; 978a75b5404SPeter Xu int i; 979a75b5404SPeter Xu 980a75b5404SPeter Xu if (!rmap_head->val) 981a75b5404SPeter Xu return false; 982a75b5404SPeter Xu 983a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 98471f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 985a75b5404SPeter Xu goto out; 986a75b5404SPeter Xu } 987a75b5404SPeter Xu 988a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 989a75b5404SPeter Xu 990a75b5404SPeter Xu for (; desc; desc = next) { 991a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 99271f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 993a75b5404SPeter Xu next = desc->more; 994a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 995a75b5404SPeter Xu } 996a75b5404SPeter Xu out: 997a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 998a75b5404SPeter Xu rmap_head->val = 0; 999a75b5404SPeter Xu return true; 1000a75b5404SPeter Xu } 1001a75b5404SPeter Xu 10023bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10033bcd0662SPeter Xu { 10043bcd0662SPeter Xu struct pte_list_desc *desc; 10053bcd0662SPeter Xu unsigned int count = 0; 10063bcd0662SPeter Xu 10073bcd0662SPeter Xu if (!rmap_head->val) 10083bcd0662SPeter Xu return 0; 10093bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10103bcd0662SPeter Xu return 1; 10113bcd0662SPeter Xu 10123bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10133bcd0662SPeter Xu 10143bcd0662SPeter Xu while (desc) { 10153bcd0662SPeter Xu count += desc->spte_count; 10163bcd0662SPeter Xu desc = desc->more; 10173bcd0662SPeter Xu } 10183bcd0662SPeter Xu 10193bcd0662SPeter Xu return count; 10203bcd0662SPeter Xu } 10213bcd0662SPeter Xu 102293e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1023269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1024c50d8ae3SPaolo Bonzini { 1025c50d8ae3SPaolo Bonzini unsigned long idx; 1026c50d8ae3SPaolo Bonzini 1027c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10283bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1029c50d8ae3SPaolo Bonzini } 1030c50d8ae3SPaolo Bonzini 1031c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1032c50d8ae3SPaolo Bonzini { 1033356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1034c50d8ae3SPaolo Bonzini 1035356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 103694ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1037c50d8ae3SPaolo Bonzini } 1038c50d8ae3SPaolo Bonzini 1039c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1040c50d8ae3SPaolo Bonzini { 1041601f8af0SDavid Matlack struct kvm_memslots *slots; 1042601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1043c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1044c50d8ae3SPaolo Bonzini gfn_t gfn; 1045c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1046c50d8ae3SPaolo Bonzini 104757354682SSean Christopherson sp = sptep_to_sp(spte); 1048c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt); 1049601f8af0SDavid Matlack 1050601f8af0SDavid Matlack /* 105168be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 105268be1306SDavid Matlack * so we have to determine which memslots to use based on context 105368be1306SDavid Matlack * information in sp->role. 1054601f8af0SDavid Matlack */ 1055601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1056601f8af0SDavid Matlack 1057601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 105893e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1059601f8af0SDavid Matlack 1060c50d8ae3SPaolo Bonzini __pte_list_remove(spte, rmap_head); 1061c50d8ae3SPaolo Bonzini } 1062c50d8ae3SPaolo Bonzini 1063c50d8ae3SPaolo Bonzini /* 1064c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1065c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1066c50d8ae3SPaolo Bonzini */ 1067c50d8ae3SPaolo Bonzini struct rmap_iterator { 1068c50d8ae3SPaolo Bonzini /* private fields */ 1069c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1070c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1071c50d8ae3SPaolo Bonzini }; 1072c50d8ae3SPaolo Bonzini 1073c50d8ae3SPaolo Bonzini /* 1074c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1075c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10760a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1077c50d8ae3SPaolo Bonzini * 1078c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1079c50d8ae3SPaolo Bonzini */ 1080c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1081c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1082c50d8ae3SPaolo Bonzini { 1083c50d8ae3SPaolo Bonzini u64 *sptep; 1084c50d8ae3SPaolo Bonzini 1085c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1086c50d8ae3SPaolo Bonzini return NULL; 1087c50d8ae3SPaolo Bonzini 1088c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1089c50d8ae3SPaolo Bonzini iter->desc = NULL; 1090c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1091c50d8ae3SPaolo Bonzini goto out; 1092c50d8ae3SPaolo Bonzini } 1093c50d8ae3SPaolo Bonzini 1094c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1095c50d8ae3SPaolo Bonzini iter->pos = 0; 1096c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1097c50d8ae3SPaolo Bonzini out: 1098c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1099c50d8ae3SPaolo Bonzini return sptep; 1100c50d8ae3SPaolo Bonzini } 1101c50d8ae3SPaolo Bonzini 1102c50d8ae3SPaolo Bonzini /* 1103c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1104c50d8ae3SPaolo Bonzini * 1105c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1106c50d8ae3SPaolo Bonzini */ 1107c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1108c50d8ae3SPaolo Bonzini { 1109c50d8ae3SPaolo Bonzini u64 *sptep; 1110c50d8ae3SPaolo Bonzini 1111c50d8ae3SPaolo Bonzini if (iter->desc) { 1112c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1113c50d8ae3SPaolo Bonzini ++iter->pos; 1114c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1115c50d8ae3SPaolo Bonzini if (sptep) 1116c50d8ae3SPaolo Bonzini goto out; 1117c50d8ae3SPaolo Bonzini } 1118c50d8ae3SPaolo Bonzini 1119c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1120c50d8ae3SPaolo Bonzini 1121c50d8ae3SPaolo Bonzini if (iter->desc) { 1122c50d8ae3SPaolo Bonzini iter->pos = 0; 1123c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1124c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1125c50d8ae3SPaolo Bonzini goto out; 1126c50d8ae3SPaolo Bonzini } 1127c50d8ae3SPaolo Bonzini } 1128c50d8ae3SPaolo Bonzini 1129c50d8ae3SPaolo Bonzini return NULL; 1130c50d8ae3SPaolo Bonzini out: 1131c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1132c50d8ae3SPaolo Bonzini return sptep; 1133c50d8ae3SPaolo Bonzini } 1134c50d8ae3SPaolo Bonzini 1135c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1136c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1137c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1138c50d8ae3SPaolo Bonzini 1139c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1140c50d8ae3SPaolo Bonzini { 114171f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11427fa2a347SSean Christopherson 11437fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1144c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1145c50d8ae3SPaolo Bonzini } 1146c50d8ae3SPaolo Bonzini 1147c50d8ae3SPaolo Bonzini 1148c50d8ae3SPaolo Bonzini static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) 1149c50d8ae3SPaolo Bonzini { 1150c50d8ae3SPaolo Bonzini if (is_large_pte(*sptep)) { 115157354682SSean Christopherson WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); 1152c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 1153c50d8ae3SPaolo Bonzini return true; 1154c50d8ae3SPaolo Bonzini } 1155c50d8ae3SPaolo Bonzini 1156c50d8ae3SPaolo Bonzini return false; 1157c50d8ae3SPaolo Bonzini } 1158c50d8ae3SPaolo Bonzini 1159c50d8ae3SPaolo Bonzini static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) 1160c50d8ae3SPaolo Bonzini { 1161c50d8ae3SPaolo Bonzini if (__drop_large_spte(vcpu->kvm, sptep)) { 116257354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 1163c50d8ae3SPaolo Bonzini 1164c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, 1165c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1166c50d8ae3SPaolo Bonzini } 1167c50d8ae3SPaolo Bonzini } 1168c50d8ae3SPaolo Bonzini 1169c50d8ae3SPaolo Bonzini /* 1170c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1171c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1172c50d8ae3SPaolo Bonzini * 1173c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1174c50d8ae3SPaolo Bonzini * protection: 1175c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1176c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1177c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1178c50d8ae3SPaolo Bonzini * shadow page. 1179c50d8ae3SPaolo Bonzini * 1180c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1181c50d8ae3SPaolo Bonzini */ 1182c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1183c50d8ae3SPaolo Bonzini { 1184c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1185c50d8ae3SPaolo Bonzini 1186c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1187c50d8ae3SPaolo Bonzini !(pt_protect && spte_can_locklessly_be_made_writable(spte))) 1188c50d8ae3SPaolo Bonzini return false; 1189c50d8ae3SPaolo Bonzini 1190805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1191c50d8ae3SPaolo Bonzini 1192c50d8ae3SPaolo Bonzini if (pt_protect) 11935fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1194c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1195c50d8ae3SPaolo Bonzini 1196c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1197c50d8ae3SPaolo Bonzini } 1198c50d8ae3SPaolo Bonzini 11991346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1200c50d8ae3SPaolo Bonzini bool pt_protect) 1201c50d8ae3SPaolo Bonzini { 1202c50d8ae3SPaolo Bonzini u64 *sptep; 1203c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1204c50d8ae3SPaolo Bonzini bool flush = false; 1205c50d8ae3SPaolo Bonzini 1206c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1207c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1208c50d8ae3SPaolo Bonzini 1209c50d8ae3SPaolo Bonzini return flush; 1210c50d8ae3SPaolo Bonzini } 1211c50d8ae3SPaolo Bonzini 1212c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1213c50d8ae3SPaolo Bonzini { 1214c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1215c50d8ae3SPaolo Bonzini 1216805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1217c50d8ae3SPaolo Bonzini 1218c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1219c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1220c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1221c50d8ae3SPaolo Bonzini } 1222c50d8ae3SPaolo Bonzini 1223c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1224c50d8ae3SPaolo Bonzini { 1225c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1226c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1227c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1228c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1229c50d8ae3SPaolo Bonzini 1230c50d8ae3SPaolo Bonzini return was_writable; 1231c50d8ae3SPaolo Bonzini } 1232c50d8ae3SPaolo Bonzini 1233c50d8ae3SPaolo Bonzini /* 1234c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1235c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1236c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1237c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1238c50d8ae3SPaolo Bonzini */ 12390a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1240269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1241c50d8ae3SPaolo Bonzini { 1242c50d8ae3SPaolo Bonzini u64 *sptep; 1243c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1244c50d8ae3SPaolo Bonzini bool flush = false; 1245c50d8ae3SPaolo Bonzini 1246c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1247c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1248c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1249c50d8ae3SPaolo Bonzini else 1250c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1251c50d8ae3SPaolo Bonzini 1252c50d8ae3SPaolo Bonzini return flush; 1253c50d8ae3SPaolo Bonzini } 1254c50d8ae3SPaolo Bonzini 1255c50d8ae3SPaolo Bonzini /** 1256c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1257c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1258c50d8ae3SPaolo Bonzini * @slot: slot to protect 1259c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1260c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1261c50d8ae3SPaolo Bonzini * 126289212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1263c50d8ae3SPaolo Bonzini */ 1264c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1265c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1266c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1267c50d8ae3SPaolo Bonzini { 1268c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1269c50d8ae3SPaolo Bonzini 1270897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1271a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1272a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1273e2209710SBen Gardon 1274e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1275e2209710SBen Gardon return; 1276e2209710SBen Gardon 1277c50d8ae3SPaolo Bonzini while (mask) { 127893e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12793bae0459SSean Christopherson PG_LEVEL_4K, slot); 12801346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1281c50d8ae3SPaolo Bonzini 1282c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1283c50d8ae3SPaolo Bonzini mask &= mask - 1; 1284c50d8ae3SPaolo Bonzini } 1285c50d8ae3SPaolo Bonzini } 1286c50d8ae3SPaolo Bonzini 1287c50d8ae3SPaolo Bonzini /** 1288c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1289c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1290c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1291c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1292c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1293c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1294c50d8ae3SPaolo Bonzini * 1295c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1296c50d8ae3SPaolo Bonzini */ 1297a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1298c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1299c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1300c50d8ae3SPaolo Bonzini { 1301c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1302c50d8ae3SPaolo Bonzini 1303897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1304a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1305a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1306e2209710SBen Gardon 1307e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1308e2209710SBen Gardon return; 1309e2209710SBen Gardon 1310c50d8ae3SPaolo Bonzini while (mask) { 131193e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13123bae0459SSean Christopherson PG_LEVEL_4K, slot); 13130a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1314c50d8ae3SPaolo Bonzini 1315c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1316c50d8ae3SPaolo Bonzini mask &= mask - 1; 1317c50d8ae3SPaolo Bonzini } 1318c50d8ae3SPaolo Bonzini } 1319c50d8ae3SPaolo Bonzini 1320c50d8ae3SPaolo Bonzini /** 1321c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1322c50d8ae3SPaolo Bonzini * PT level pages. 1323c50d8ae3SPaolo Bonzini * 1324c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1325c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1326c50d8ae3SPaolo Bonzini * 132789212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 132889212919SKeqian Zhu * have such mappings. 1329c50d8ae3SPaolo Bonzini */ 1330c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1331c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1332c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1333c50d8ae3SPaolo Bonzini { 133489212919SKeqian Zhu /* 133589212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 133689212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 133789212919SKeqian Zhu * are split to 4K on the first write. 133889212919SKeqian Zhu * 133989212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 134089212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 134189212919SKeqian Zhu * pages. 134289212919SKeqian Zhu */ 134389212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 134489212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 134589212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 134689212919SKeqian Zhu 1347cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1348cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1349cb00a70bSDavid Matlack 135089212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 135189212919SKeqian Zhu 135289212919SKeqian Zhu /* Cross two large pages? */ 135389212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 135489212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 135589212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 135689212919SKeqian Zhu PG_LEVEL_2M); 135789212919SKeqian Zhu } 135889212919SKeqian Zhu 135989212919SKeqian Zhu /* Now handle 4K PTEs. */ 1360a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1361a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1362c50d8ae3SPaolo Bonzini else 1363c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1364c50d8ae3SPaolo Bonzini } 1365c50d8ae3SPaolo Bonzini 1366fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1367fb04a1edSPeter Xu { 13686dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1369fb04a1edSPeter Xu } 1370fb04a1edSPeter Xu 1371c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13723ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13733ad93562SKeqian Zhu int min_level) 1374c50d8ae3SPaolo Bonzini { 1375c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1376c50d8ae3SPaolo Bonzini int i; 1377c50d8ae3SPaolo Bonzini bool write_protected = false; 1378c50d8ae3SPaolo Bonzini 1379e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13803ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 138193e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13821346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1383c50d8ae3SPaolo Bonzini } 1384e2209710SBen Gardon } 1385c50d8ae3SPaolo Bonzini 1386897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 138746044f72SBen Gardon write_protected |= 13883ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 138946044f72SBen Gardon 1390c50d8ae3SPaolo Bonzini return write_protected; 1391c50d8ae3SPaolo Bonzini } 1392c50d8ae3SPaolo Bonzini 1393cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1394c50d8ae3SPaolo Bonzini { 1395c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1396c50d8ae3SPaolo Bonzini 1397c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 13983ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1399c50d8ae3SPaolo Bonzini } 1400c50d8ae3SPaolo Bonzini 14010a234f5dSSean Christopherson static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1402269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1403c50d8ae3SPaolo Bonzini { 140471f51d2cSMingwei Zhang return pte_list_destroy(kvm, rmap_head); 1405c50d8ae3SPaolo Bonzini } 1406c50d8ae3SPaolo Bonzini 14073039bcc7SSean Christopherson static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1408c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14093039bcc7SSean Christopherson pte_t unused) 1410c50d8ae3SPaolo Bonzini { 14110a234f5dSSean Christopherson return kvm_zap_rmapp(kvm, rmap_head, slot); 1412c50d8ae3SPaolo Bonzini } 1413c50d8ae3SPaolo Bonzini 14143039bcc7SSean Christopherson static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1415c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14163039bcc7SSean Christopherson pte_t pte) 1417c50d8ae3SPaolo Bonzini { 1418c50d8ae3SPaolo Bonzini u64 *sptep; 1419c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 142098a26b69SVihas Mak bool need_flush = false; 1421c50d8ae3SPaolo Bonzini u64 new_spte; 1422c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1423c50d8ae3SPaolo Bonzini 14243039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14253039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1426c50d8ae3SPaolo Bonzini 1427c50d8ae3SPaolo Bonzini restart: 1428c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1429805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1430c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1431c50d8ae3SPaolo Bonzini 143298a26b69SVihas Mak need_flush = true; 1433c50d8ae3SPaolo Bonzini 14343039bcc7SSean Christopherson if (pte_write(pte)) { 143571f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 1436c50d8ae3SPaolo Bonzini goto restart; 1437c50d8ae3SPaolo Bonzini } else { 1438cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1439cb3eedabSPaolo Bonzini *sptep, new_pfn); 1440c50d8ae3SPaolo Bonzini 144171f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1442c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1443c50d8ae3SPaolo Bonzini } 1444c50d8ae3SPaolo Bonzini } 1445c50d8ae3SPaolo Bonzini 1446c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1447c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 144898a26b69SVihas Mak return false; 1449c50d8ae3SPaolo Bonzini } 1450c50d8ae3SPaolo Bonzini 1451c50d8ae3SPaolo Bonzini return need_flush; 1452c50d8ae3SPaolo Bonzini } 1453c50d8ae3SPaolo Bonzini 1454c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1455c50d8ae3SPaolo Bonzini /* input fields. */ 1456269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1457c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1458c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1459c50d8ae3SPaolo Bonzini int start_level; 1460c50d8ae3SPaolo Bonzini int end_level; 1461c50d8ae3SPaolo Bonzini 1462c50d8ae3SPaolo Bonzini /* output fields. */ 1463c50d8ae3SPaolo Bonzini gfn_t gfn; 1464c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1465c50d8ae3SPaolo Bonzini int level; 1466c50d8ae3SPaolo Bonzini 1467c50d8ae3SPaolo Bonzini /* private field. */ 1468c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1469c50d8ae3SPaolo Bonzini }; 1470c50d8ae3SPaolo Bonzini 1471c50d8ae3SPaolo Bonzini static void 1472c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1473c50d8ae3SPaolo Bonzini { 1474c50d8ae3SPaolo Bonzini iterator->level = level; 1475c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 147693e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 147793e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1478c50d8ae3SPaolo Bonzini } 1479c50d8ae3SPaolo Bonzini 1480c50d8ae3SPaolo Bonzini static void 1481c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1482269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1483c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1484c50d8ae3SPaolo Bonzini { 1485c50d8ae3SPaolo Bonzini iterator->slot = slot; 1486c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1487c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1488c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1489c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1490c50d8ae3SPaolo Bonzini 1491c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1492c50d8ae3SPaolo Bonzini } 1493c50d8ae3SPaolo Bonzini 1494c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1495c50d8ae3SPaolo Bonzini { 1496c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1497c50d8ae3SPaolo Bonzini } 1498c50d8ae3SPaolo Bonzini 1499c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1500c50d8ae3SPaolo Bonzini { 1501c50d8ae3SPaolo Bonzini if (++iterator->rmap <= iterator->end_rmap) { 1502c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 1503c50d8ae3SPaolo Bonzini return; 1504c50d8ae3SPaolo Bonzini } 1505c50d8ae3SPaolo Bonzini 1506c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1507c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1508c50d8ae3SPaolo Bonzini return; 1509c50d8ae3SPaolo Bonzini } 1510c50d8ae3SPaolo Bonzini 1511c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1512c50d8ae3SPaolo Bonzini } 1513c50d8ae3SPaolo Bonzini 1514c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1515c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1516c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1517c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1518c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1519c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1520c50d8ae3SPaolo Bonzini 15213039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1522c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15233039bcc7SSean Christopherson int level, pte_t pte); 1524c1b91493SSean Christopherson 15253039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15263039bcc7SSean Christopherson struct kvm_gfn_range *range, 1527c1b91493SSean Christopherson rmap_handler_t handler) 1528c50d8ae3SPaolo Bonzini { 1529c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15303039bcc7SSean Christopherson bool ret = false; 1531c50d8ae3SPaolo Bonzini 15323039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15333039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15343039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15353039bcc7SSean Christopherson iterator.level, range->pte); 1536c50d8ae3SPaolo Bonzini 1537c50d8ae3SPaolo Bonzini return ret; 1538c50d8ae3SPaolo Bonzini } 1539c50d8ae3SPaolo Bonzini 15403039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1541c50d8ae3SPaolo Bonzini { 1542e2209710SBen Gardon bool flush = false; 1543c50d8ae3SPaolo Bonzini 1544e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15453039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp); 1546063afacdSBen Gardon 1547897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1548c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1549063afacdSBen Gardon 15503039bcc7SSean Christopherson return flush; 1551c50d8ae3SPaolo Bonzini } 1552c50d8ae3SPaolo Bonzini 15533039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1554c50d8ae3SPaolo Bonzini { 1555e2209710SBen Gardon bool flush = false; 15561d8dd6b3SBen Gardon 1557e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15583039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp); 15591d8dd6b3SBen Gardon 1560897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15613039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15621d8dd6b3SBen Gardon 15633039bcc7SSean Christopherson return flush; 1564c50d8ae3SPaolo Bonzini } 1565c50d8ae3SPaolo Bonzini 15663039bcc7SSean Christopherson static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1567c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15683039bcc7SSean Christopherson pte_t unused) 1569c50d8ae3SPaolo Bonzini { 1570c50d8ae3SPaolo Bonzini u64 *sptep; 15713f649ab7SKees Cook struct rmap_iterator iter; 1572c50d8ae3SPaolo Bonzini int young = 0; 1573c50d8ae3SPaolo Bonzini 1574c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1575c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1576c50d8ae3SPaolo Bonzini 1577c50d8ae3SPaolo Bonzini return young; 1578c50d8ae3SPaolo Bonzini } 1579c50d8ae3SPaolo Bonzini 15803039bcc7SSean Christopherson static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1581c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15823039bcc7SSean Christopherson int level, pte_t unused) 1583c50d8ae3SPaolo Bonzini { 1584c50d8ae3SPaolo Bonzini u64 *sptep; 1585c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1586c50d8ae3SPaolo Bonzini 1587c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1588c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 158998a26b69SVihas Mak return true; 159098a26b69SVihas Mak return false; 1591c50d8ae3SPaolo Bonzini } 1592c50d8ae3SPaolo Bonzini 1593c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1594c50d8ae3SPaolo Bonzini 15958a9f566aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 15968a9f566aSDavid Matlack u64 *spte, gfn_t gfn) 1597c50d8ae3SPaolo Bonzini { 1598c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 159968be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 160068be1306SDavid Matlack int rmap_count; 1601c50d8ae3SPaolo Bonzini 160257354682SSean Christopherson sp = sptep_to_sp(spte); 160368be1306SDavid Matlack kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn); 160493e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 160568be1306SDavid Matlack rmap_count = pte_list_add(vcpu, spte, rmap_head); 1606c50d8ae3SPaolo Bonzini 160768be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16083039bcc7SSean Christopherson kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0)); 160968be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 161068be1306SDavid Matlack vcpu->kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 161168be1306SDavid Matlack } 1612c50d8ae3SPaolo Bonzini } 1613c50d8ae3SPaolo Bonzini 16143039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1615c50d8ae3SPaolo Bonzini { 1616e2209710SBen Gardon bool young = false; 1617f8e14497SBen Gardon 1618e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16193039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp); 16203039bcc7SSean Christopherson 1621897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16223039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1623f8e14497SBen Gardon 1624f8e14497SBen Gardon return young; 1625c50d8ae3SPaolo Bonzini } 1626c50d8ae3SPaolo Bonzini 16273039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1628c50d8ae3SPaolo Bonzini { 1629e2209710SBen Gardon bool young = false; 1630f8e14497SBen Gardon 1631e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16323039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp); 16333039bcc7SSean Christopherson 1634897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16353039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1636f8e14497SBen Gardon 1637f8e14497SBen Gardon return young; 1638c50d8ae3SPaolo Bonzini } 1639c50d8ae3SPaolo Bonzini 1640c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1641c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1642c50d8ae3SPaolo Bonzini { 1643c50d8ae3SPaolo Bonzini u64 *pos; 1644c50d8ae3SPaolo Bonzini u64 *end; 1645c50d8ae3SPaolo Bonzini 1646c50d8ae3SPaolo Bonzini for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) 1647c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1648c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1649c50d8ae3SPaolo Bonzini pos, *pos); 1650c50d8ae3SPaolo Bonzini return 0; 1651c50d8ae3SPaolo Bonzini } 1652c50d8ae3SPaolo Bonzini return 1; 1653c50d8ae3SPaolo Bonzini } 1654c50d8ae3SPaolo Bonzini #endif 1655c50d8ae3SPaolo Bonzini 1656c50d8ae3SPaolo Bonzini /* 1657c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1658c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1659c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1660c50d8ae3SPaolo Bonzini * faster 1661c50d8ae3SPaolo Bonzini */ 1662d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1663c50d8ae3SPaolo Bonzini { 1664c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1665c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1666c50d8ae3SPaolo Bonzini } 1667c50d8ae3SPaolo Bonzini 1668c50d8ae3SPaolo Bonzini static void kvm_mmu_free_page(struct kvm_mmu_page *sp) 1669c50d8ae3SPaolo Bonzini { 1670c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1671c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1672c50d8ae3SPaolo Bonzini list_del(&sp->link); 1673c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1674c50d8ae3SPaolo Bonzini if (!sp->role.direct) 1675c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->gfns); 1676c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1677c50d8ae3SPaolo Bonzini } 1678c50d8ae3SPaolo Bonzini 1679c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1680c50d8ae3SPaolo Bonzini { 1681c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1682c50d8ae3SPaolo Bonzini } 1683c50d8ae3SPaolo Bonzini 1684c50d8ae3SPaolo Bonzini static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, 1685c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1686c50d8ae3SPaolo Bonzini { 1687c50d8ae3SPaolo Bonzini if (!parent_pte) 1688c50d8ae3SPaolo Bonzini return; 1689c50d8ae3SPaolo Bonzini 1690c50d8ae3SPaolo Bonzini pte_list_add(vcpu, parent_pte, &sp->parent_ptes); 1691c50d8ae3SPaolo Bonzini } 1692c50d8ae3SPaolo Bonzini 1693c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1694c50d8ae3SPaolo Bonzini u64 *parent_pte) 1695c50d8ae3SPaolo Bonzini { 1696c50d8ae3SPaolo Bonzini __pte_list_remove(parent_pte, &sp->parent_ptes); 1697c50d8ae3SPaolo Bonzini } 1698c50d8ae3SPaolo Bonzini 1699c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1700c50d8ae3SPaolo Bonzini u64 *parent_pte) 1701c50d8ae3SPaolo Bonzini { 1702c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1703c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1704c50d8ae3SPaolo Bonzini } 1705c50d8ae3SPaolo Bonzini 1706c50d8ae3SPaolo Bonzini static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct) 1707c50d8ae3SPaolo Bonzini { 1708c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1709c50d8ae3SPaolo Bonzini 171094ce87efSSean Christopherson sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache); 171194ce87efSSean Christopherson sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache); 1712c50d8ae3SPaolo Bonzini if (!direct) 171394ce87efSSean Christopherson sp->gfns = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache); 1714c50d8ae3SPaolo Bonzini set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 1715c50d8ae3SPaolo Bonzini 1716c50d8ae3SPaolo Bonzini /* 1717c50d8ae3SPaolo Bonzini * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 1718c50d8ae3SPaolo Bonzini * depends on valid pages being added to the head of the list. See 1719c50d8ae3SPaolo Bonzini * comments in kvm_zap_obsolete_pages(). 1720c50d8ae3SPaolo Bonzini */ 1721c50d8ae3SPaolo Bonzini sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; 1722c50d8ae3SPaolo Bonzini list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); 1723c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(vcpu->kvm, +1); 1724c50d8ae3SPaolo Bonzini return sp; 1725c50d8ae3SPaolo Bonzini } 1726c50d8ae3SPaolo Bonzini 1727c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1728c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1729c50d8ae3SPaolo Bonzini { 1730c50d8ae3SPaolo Bonzini u64 *sptep; 1731c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1732c50d8ae3SPaolo Bonzini 1733c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1734c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1735c50d8ae3SPaolo Bonzini } 1736c50d8ae3SPaolo Bonzini } 1737c50d8ae3SPaolo Bonzini 1738c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1739c50d8ae3SPaolo Bonzini { 1740c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1741c50d8ae3SPaolo Bonzini unsigned int index; 1742c50d8ae3SPaolo Bonzini 174357354682SSean Christopherson sp = sptep_to_sp(spte); 1744c50d8ae3SPaolo Bonzini index = spte - sp->spt; 1745c50d8ae3SPaolo Bonzini if (__test_and_set_bit(index, sp->unsync_child_bitmap)) 1746c50d8ae3SPaolo Bonzini return; 1747c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1748c50d8ae3SPaolo Bonzini return; 1749c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1750c50d8ae3SPaolo Bonzini } 1751c50d8ae3SPaolo Bonzini 1752c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1753c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1754c50d8ae3SPaolo Bonzini { 1755c3e5e415SLai Jiangshan return -1; 1756c50d8ae3SPaolo Bonzini } 1757c50d8ae3SPaolo Bonzini 1758c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1759c50d8ae3SPaolo Bonzini 1760c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1761c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1762c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1763c50d8ae3SPaolo Bonzini unsigned int idx; 1764c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1765c50d8ae3SPaolo Bonzini unsigned int nr; 1766c50d8ae3SPaolo Bonzini }; 1767c50d8ae3SPaolo Bonzini 1768c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1769c50d8ae3SPaolo Bonzini int idx) 1770c50d8ae3SPaolo Bonzini { 1771c50d8ae3SPaolo Bonzini int i; 1772c50d8ae3SPaolo Bonzini 1773c50d8ae3SPaolo Bonzini if (sp->unsync) 1774c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1775c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1776c50d8ae3SPaolo Bonzini return 0; 1777c50d8ae3SPaolo Bonzini 1778c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1779c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1780c50d8ae3SPaolo Bonzini pvec->nr++; 1781c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1782c50d8ae3SPaolo Bonzini } 1783c50d8ae3SPaolo Bonzini 1784c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1785c50d8ae3SPaolo Bonzini { 1786c50d8ae3SPaolo Bonzini --sp->unsync_children; 1787c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1788c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1789c50d8ae3SPaolo Bonzini } 1790c50d8ae3SPaolo Bonzini 1791c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1792c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1793c50d8ae3SPaolo Bonzini { 1794c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1795c50d8ae3SPaolo Bonzini 1796c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1797c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1798c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1799c50d8ae3SPaolo Bonzini 1800c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1801c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1802c50d8ae3SPaolo Bonzini continue; 1803c50d8ae3SPaolo Bonzini } 1804c50d8ae3SPaolo Bonzini 1805e47c4aeeSSean Christopherson child = to_shadow_page(ent & PT64_BASE_ADDR_MASK); 1806c50d8ae3SPaolo Bonzini 1807c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1808c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1809c50d8ae3SPaolo Bonzini return -ENOSPC; 1810c50d8ae3SPaolo Bonzini 1811c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1812c50d8ae3SPaolo Bonzini if (!ret) { 1813c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1814c50d8ae3SPaolo Bonzini continue; 1815c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1816c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1817c50d8ae3SPaolo Bonzini } else 1818c50d8ae3SPaolo Bonzini return ret; 1819c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1820c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1821c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1822c50d8ae3SPaolo Bonzini return -ENOSPC; 1823c50d8ae3SPaolo Bonzini } else 1824c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1825c50d8ae3SPaolo Bonzini } 1826c50d8ae3SPaolo Bonzini 1827c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1828c50d8ae3SPaolo Bonzini } 1829c50d8ae3SPaolo Bonzini 1830c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1831c50d8ae3SPaolo Bonzini 1832c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1833c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1834c50d8ae3SPaolo Bonzini { 1835c50d8ae3SPaolo Bonzini pvec->nr = 0; 1836c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1837c50d8ae3SPaolo Bonzini return 0; 1838c50d8ae3SPaolo Bonzini 1839c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1840c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1841c50d8ae3SPaolo Bonzini } 1842c50d8ae3SPaolo Bonzini 1843c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1844c50d8ae3SPaolo Bonzini { 1845c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1846c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1847c50d8ae3SPaolo Bonzini sp->unsync = 0; 1848c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1849c50d8ae3SPaolo Bonzini } 1850c50d8ae3SPaolo Bonzini 1851c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1852c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1853c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1854c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1855c50d8ae3SPaolo Bonzini 1856ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1857ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1858c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1859c50d8ae3SPaolo Bonzini } else 1860c50d8ae3SPaolo Bonzini 1861c50d8ae3SPaolo Bonzini #define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn) \ 1862ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1863ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1864c50d8ae3SPaolo Bonzini if ((_sp)->gfn != (_gfn) || (_sp)->role.direct) {} else 1865c50d8ae3SPaolo Bonzini 18668d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1867c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1868c50d8ae3SPaolo Bonzini { 1869c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1870c3e5e415SLai Jiangshan 18718d5678a7SHou Wenlong if (ret < 0) 1872c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18738d5678a7SHou Wenlong return ret; 1874c50d8ae3SPaolo Bonzini } 1875c50d8ae3SPaolo Bonzini 1876c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1877c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1878c50d8ae3SPaolo Bonzini bool remote_flush) 1879c50d8ae3SPaolo Bonzini { 1880c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1881c50d8ae3SPaolo Bonzini return false; 1882c50d8ae3SPaolo Bonzini 1883c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1884c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1885c50d8ae3SPaolo Bonzini else 1886c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1887c50d8ae3SPaolo Bonzini return true; 1888c50d8ae3SPaolo Bonzini } 1889c50d8ae3SPaolo Bonzini 1890c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1891c50d8ae3SPaolo Bonzini { 1892a955cad8SSean Christopherson if (sp->role.invalid) 1893a955cad8SSean Christopherson return true; 1894a955cad8SSean Christopherson 1895a955cad8SSean Christopherson /* TDP MMU pages due not use the MMU generation. */ 1896a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1897c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1898c50d8ae3SPaolo Bonzini } 1899c50d8ae3SPaolo Bonzini 1900c50d8ae3SPaolo Bonzini struct mmu_page_path { 1901c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1902c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1903c50d8ae3SPaolo Bonzini }; 1904c50d8ae3SPaolo Bonzini 1905c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1906c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1907c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1908c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1909c50d8ae3SPaolo Bonzini 1910c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1911c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1912c50d8ae3SPaolo Bonzini int i) 1913c50d8ae3SPaolo Bonzini { 1914c50d8ae3SPaolo Bonzini int n; 1915c50d8ae3SPaolo Bonzini 1916c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1917c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1918c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1919c50d8ae3SPaolo Bonzini int level = sp->role.level; 1920c50d8ae3SPaolo Bonzini 1921c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19223bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1923c50d8ae3SPaolo Bonzini break; 1924c50d8ae3SPaolo Bonzini 1925c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1926c50d8ae3SPaolo Bonzini } 1927c50d8ae3SPaolo Bonzini 1928c50d8ae3SPaolo Bonzini return n; 1929c50d8ae3SPaolo Bonzini } 1930c50d8ae3SPaolo Bonzini 1931c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1932c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1933c50d8ae3SPaolo Bonzini { 1934c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1935c50d8ae3SPaolo Bonzini int level; 1936c50d8ae3SPaolo Bonzini 1937c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1938c50d8ae3SPaolo Bonzini return 0; 1939c50d8ae3SPaolo Bonzini 1940c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1941c50d8ae3SPaolo Bonzini 1942c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1943c50d8ae3SPaolo Bonzini level = sp->role.level; 19443bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1945c50d8ae3SPaolo Bonzini 1946c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1947c50d8ae3SPaolo Bonzini 1948c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1949c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1950c50d8ae3SPaolo Bonzini */ 1951c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1952c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1953c50d8ae3SPaolo Bonzini } 1954c50d8ae3SPaolo Bonzini 1955c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1956c50d8ae3SPaolo Bonzini { 1957c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1958c50d8ae3SPaolo Bonzini unsigned int level = 0; 1959c50d8ae3SPaolo Bonzini 1960c50d8ae3SPaolo Bonzini do { 1961c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1962c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1963c50d8ae3SPaolo Bonzini if (!sp) 1964c50d8ae3SPaolo Bonzini return; 1965c50d8ae3SPaolo Bonzini 1966c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1967c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1968c50d8ae3SPaolo Bonzini level++; 1969c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1970c50d8ae3SPaolo Bonzini } 1971c50d8ae3SPaolo Bonzini 197265855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 197365855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1974c50d8ae3SPaolo Bonzini { 1975c50d8ae3SPaolo Bonzini int i; 1976c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1977c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1978c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1979c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1980c50d8ae3SPaolo Bonzini bool flush = false; 1981c50d8ae3SPaolo Bonzini 1982c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 1983c50d8ae3SPaolo Bonzini bool protected = false; 1984c50d8ae3SPaolo Bonzini 1985c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 1986cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 1987c50d8ae3SPaolo Bonzini 1988c50d8ae3SPaolo Bonzini if (protected) { 19895591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 1990c50d8ae3SPaolo Bonzini flush = false; 1991c50d8ae3SPaolo Bonzini } 1992c50d8ae3SPaolo Bonzini 1993c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 1994479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 19958d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 1996c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 1997c50d8ae3SPaolo Bonzini } 1998531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 1999c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 200065855ed8SLai Jiangshan if (!can_yield) { 200165855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 200265855ed8SLai Jiangshan return -EINTR; 200365855ed8SLai Jiangshan } 200465855ed8SLai Jiangshan 2005531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2006c50d8ae3SPaolo Bonzini flush = false; 2007c50d8ae3SPaolo Bonzini } 2008c50d8ae3SPaolo Bonzini } 2009c50d8ae3SPaolo Bonzini 2010c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 201165855ed8SLai Jiangshan return 0; 2012c50d8ae3SPaolo Bonzini } 2013c50d8ae3SPaolo Bonzini 2014c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2015c50d8ae3SPaolo Bonzini { 2016c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2017c50d8ae3SPaolo Bonzini } 2018c50d8ae3SPaolo Bonzini 2019c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2020c50d8ae3SPaolo Bonzini { 202157354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2022c50d8ae3SPaolo Bonzini } 2023c50d8ae3SPaolo Bonzini 2024c50d8ae3SPaolo Bonzini static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, 2025c50d8ae3SPaolo Bonzini gfn_t gfn, 2026c50d8ae3SPaolo Bonzini gva_t gaddr, 2027c50d8ae3SPaolo Bonzini unsigned level, 2028c50d8ae3SPaolo Bonzini int direct, 20290a2b64c5SBen Gardon unsigned int access) 2030c50d8ae3SPaolo Bonzini { 2031*347a0d0dSPaolo Bonzini bool direct_mmu = vcpu->arch.mmu->root_role.direct; 2032c50d8ae3SPaolo Bonzini union kvm_mmu_page_role role; 2033ac101b7cSSean Christopherson struct hlist_head *sp_list; 2034c50d8ae3SPaolo Bonzini unsigned quadrant; 2035c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20368d5678a7SHou Wenlong int ret; 2037c50d8ae3SPaolo Bonzini int collisions = 0; 2038c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2039c50d8ae3SPaolo Bonzini 20407a458f0eSPaolo Bonzini role = vcpu->arch.mmu->root_role; 2041c50d8ae3SPaolo Bonzini role.level = level; 2042c50d8ae3SPaolo Bonzini role.direct = direct; 2043c50d8ae3SPaolo Bonzini role.access = access; 2044bb3b394dSLai Jiangshan if (role.has_4_byte_gpte) { 2045c50d8ae3SPaolo Bonzini quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level)); 2046c50d8ae3SPaolo Bonzini quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; 2047c50d8ae3SPaolo Bonzini role.quadrant = quadrant; 2048c50d8ae3SPaolo Bonzini } 2049ac101b7cSSean Christopherson 2050ac101b7cSSean Christopherson sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 2051ac101b7cSSean Christopherson for_each_valid_sp(vcpu->kvm, sp, sp_list) { 2052c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2053c50d8ae3SPaolo Bonzini collisions++; 2054c50d8ae3SPaolo Bonzini continue; 2055c50d8ae3SPaolo Bonzini } 2056c50d8ae3SPaolo Bonzini 2057ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2058ddc16abbSSean Christopherson /* 2059ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2060ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2061ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2062ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2063ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2064ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2065ddc16abbSSean Christopherson * upper-level page will be write-protected. 2066ddc16abbSSean Christopherson */ 2067ddc16abbSSean Christopherson if (level > PG_LEVEL_4K && sp->unsync) 2068ddc16abbSSean Christopherson kvm_mmu_prepare_zap_page(vcpu->kvm, sp, 2069ddc16abbSSean Christopherson &invalid_list); 2070c50d8ae3SPaolo Bonzini continue; 2071ddc16abbSSean Christopherson } 2072c50d8ae3SPaolo Bonzini 2073fb58a9c3SSean Christopherson if (direct_mmu) 2074fb58a9c3SSean Christopherson goto trace_get_page; 2075fb58a9c3SSean Christopherson 2076c50d8ae3SPaolo Bonzini if (sp->unsync) { 207707dc4f35SSean Christopherson /* 2078479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 207907dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 208007dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 208107dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 208207dc4f35SSean Christopherson * overhead of write protection is not incurred until the 208307dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 208407dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 208507dc4f35SSean Christopherson * 208607dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 208707dc4f35SSean Christopherson * in order to rebuild it. 2088c50d8ae3SPaolo Bonzini */ 20898d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 20908d5678a7SHou Wenlong if (ret < 0) 2091c50d8ae3SPaolo Bonzini break; 2092c50d8ae3SPaolo Bonzini 2093c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 20948d5678a7SHou Wenlong if (ret > 0) 2095c3e5e415SLai Jiangshan kvm_flush_remote_tlbs(vcpu->kvm); 2096c50d8ae3SPaolo Bonzini } 2097c50d8ae3SPaolo Bonzini 2098c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2099fb58a9c3SSean Christopherson 2100fb58a9c3SSean Christopherson trace_get_page: 2101c50d8ae3SPaolo Bonzini trace_kvm_mmu_get_page(sp, false); 2102c50d8ae3SPaolo Bonzini goto out; 2103c50d8ae3SPaolo Bonzini } 2104c50d8ae3SPaolo Bonzini 2105c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_cache_miss; 2106c50d8ae3SPaolo Bonzini 2107c50d8ae3SPaolo Bonzini sp = kvm_mmu_alloc_page(vcpu, direct); 2108c50d8ae3SPaolo Bonzini 2109c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2110c50d8ae3SPaolo Bonzini sp->role = role; 2111ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2112c50d8ae3SPaolo Bonzini if (!direct) { 2113c50d8ae3SPaolo Bonzini account_shadowed(vcpu->kvm, sp); 2114cf48f9e2SDavid Matlack if (level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn)) 2115c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1); 2116c50d8ae3SPaolo Bonzini } 2117c50d8ae3SPaolo Bonzini trace_kvm_mmu_get_page(sp, true); 2118c50d8ae3SPaolo Bonzini out: 2119ddc16abbSSean Christopherson kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); 2120ddc16abbSSean Christopherson 2121c50d8ae3SPaolo Bonzini if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions) 2122c50d8ae3SPaolo Bonzini vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions; 2123c50d8ae3SPaolo Bonzini return sp; 2124c50d8ae3SPaolo Bonzini } 2125c50d8ae3SPaolo Bonzini 2126c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2127c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2128c50d8ae3SPaolo Bonzini u64 addr) 2129c50d8ae3SPaolo Bonzini { 2130c50d8ae3SPaolo Bonzini iterator->addr = addr; 2131c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2132a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2133c50d8ae3SPaolo Bonzini 213412ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 21354d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2136*347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 213712ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2138c50d8ae3SPaolo Bonzini 2139c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2140c50d8ae3SPaolo Bonzini /* 2141c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2142c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2143c50d8ae3SPaolo Bonzini */ 2144b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2145c50d8ae3SPaolo Bonzini 2146c50d8ae3SPaolo Bonzini iterator->shadow_addr 2147c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 2148c50d8ae3SPaolo Bonzini iterator->shadow_addr &= PT64_BASE_ADDR_MASK; 2149c50d8ae3SPaolo Bonzini --iterator->level; 2150c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2151c50d8ae3SPaolo Bonzini iterator->level = 0; 2152c50d8ae3SPaolo Bonzini } 2153c50d8ae3SPaolo Bonzini } 2154c50d8ae3SPaolo Bonzini 2155c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2156c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2157c50d8ae3SPaolo Bonzini { 2158b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2159c50d8ae3SPaolo Bonzini addr); 2160c50d8ae3SPaolo Bonzini } 2161c50d8ae3SPaolo Bonzini 2162c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2163c50d8ae3SPaolo Bonzini { 21643bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2165c50d8ae3SPaolo Bonzini return false; 2166c50d8ae3SPaolo Bonzini 2167c50d8ae3SPaolo Bonzini iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level); 2168c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2169c50d8ae3SPaolo Bonzini return true; 2170c50d8ae3SPaolo Bonzini } 2171c50d8ae3SPaolo Bonzini 2172c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2173c50d8ae3SPaolo Bonzini u64 spte) 2174c50d8ae3SPaolo Bonzini { 21753e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2176c50d8ae3SPaolo Bonzini iterator->level = 0; 2177c50d8ae3SPaolo Bonzini return; 2178c50d8ae3SPaolo Bonzini } 2179c50d8ae3SPaolo Bonzini 2180c50d8ae3SPaolo Bonzini iterator->shadow_addr = spte & PT64_BASE_ADDR_MASK; 2181c50d8ae3SPaolo Bonzini --iterator->level; 2182c50d8ae3SPaolo Bonzini } 2183c50d8ae3SPaolo Bonzini 2184c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2185c50d8ae3SPaolo Bonzini { 2186c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2187c50d8ae3SPaolo Bonzini } 2188c50d8ae3SPaolo Bonzini 2189c50d8ae3SPaolo Bonzini static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 2190c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 2191c50d8ae3SPaolo Bonzini { 2192c50d8ae3SPaolo Bonzini u64 spte; 2193c50d8ae3SPaolo Bonzini 2194c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2195c50d8ae3SPaolo Bonzini 2196cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2197c50d8ae3SPaolo Bonzini 2198c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2199c50d8ae3SPaolo Bonzini 2200c50d8ae3SPaolo Bonzini mmu_page_add_parent_pte(vcpu, sp, sptep); 2201c50d8ae3SPaolo Bonzini 2202c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2203c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2204c50d8ae3SPaolo Bonzini } 2205c50d8ae3SPaolo Bonzini 2206c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2207c50d8ae3SPaolo Bonzini unsigned direct_access) 2208c50d8ae3SPaolo Bonzini { 2209c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2210c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2211c50d8ae3SPaolo Bonzini 2212c50d8ae3SPaolo Bonzini /* 2213c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2214c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2215c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2216c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2217c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2218c50d8ae3SPaolo Bonzini */ 2219e47c4aeeSSean Christopherson child = to_shadow_page(*sptep & PT64_BASE_ADDR_MASK); 2220c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2221c50d8ae3SPaolo Bonzini return; 2222c50d8ae3SPaolo Bonzini 2223c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2224c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2225c50d8ae3SPaolo Bonzini } 2226c50d8ae3SPaolo Bonzini } 2227c50d8ae3SPaolo Bonzini 22282de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 22292de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 22302de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2231c50d8ae3SPaolo Bonzini { 2232c50d8ae3SPaolo Bonzini u64 pte; 2233c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2234c50d8ae3SPaolo Bonzini 2235c50d8ae3SPaolo Bonzini pte = *spte; 2236c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2237c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2238c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2239c50d8ae3SPaolo Bonzini } else { 2240e47c4aeeSSean Christopherson child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); 2241c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 22422de4085cSBen Gardon 22432de4085cSBen Gardon /* 22442de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 22452de4085cSBen Gardon * unlikely to be used again in the near future. This 22462de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 22472de4085cSBen Gardon */ 22482de4085cSBen Gardon if (tdp_enabled && invalid_list && 22492de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 22502de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 22512de4085cSBen Gardon invalid_list); 2252c50d8ae3SPaolo Bonzini } 2253ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2254c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2255ace569e0SSean Christopherson } 22562de4085cSBen Gardon return 0; 2257c50d8ae3SPaolo Bonzini } 2258c50d8ae3SPaolo Bonzini 22592de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 22602de4085cSBen Gardon struct kvm_mmu_page *sp, 22612de4085cSBen Gardon struct list_head *invalid_list) 2262c50d8ae3SPaolo Bonzini { 22632de4085cSBen Gardon int zapped = 0; 2264c50d8ae3SPaolo Bonzini unsigned i; 2265c50d8ae3SPaolo Bonzini 2266c50d8ae3SPaolo Bonzini for (i = 0; i < PT64_ENT_PER_PAGE; ++i) 22672de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 22682de4085cSBen Gardon 22692de4085cSBen Gardon return zapped; 2270c50d8ae3SPaolo Bonzini } 2271c50d8ae3SPaolo Bonzini 227261827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2273c50d8ae3SPaolo Bonzini { 2274c50d8ae3SPaolo Bonzini u64 *sptep; 2275c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2276c50d8ae3SPaolo Bonzini 2277c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2278c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2279c50d8ae3SPaolo Bonzini } 2280c50d8ae3SPaolo Bonzini 2281c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2282c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2283c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2284c50d8ae3SPaolo Bonzini { 2285c50d8ae3SPaolo Bonzini int i, zapped = 0; 2286c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2287c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2288c50d8ae3SPaolo Bonzini 22893bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2290c50d8ae3SPaolo Bonzini return 0; 2291c50d8ae3SPaolo Bonzini 2292c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2293c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2294c50d8ae3SPaolo Bonzini 2295c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2296c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2297c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2298c50d8ae3SPaolo Bonzini zapped++; 2299c50d8ae3SPaolo Bonzini } 2300c50d8ae3SPaolo Bonzini } 2301c50d8ae3SPaolo Bonzini 2302c50d8ae3SPaolo Bonzini return zapped; 2303c50d8ae3SPaolo Bonzini } 2304c50d8ae3SPaolo Bonzini 2305c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2306c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2307c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2308c50d8ae3SPaolo Bonzini int *nr_zapped) 2309c50d8ae3SPaolo Bonzini { 2310527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2311c50d8ae3SPaolo Bonzini 2312c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2313c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2314c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 23152de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 231661827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2317c50d8ae3SPaolo Bonzini 2318c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2319c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2320c50d8ae3SPaolo Bonzini 2321c50d8ae3SPaolo Bonzini if (!sp->role.invalid && !sp->role.direct) 2322c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2323c50d8ae3SPaolo Bonzini 2324c50d8ae3SPaolo Bonzini if (sp->unsync) 2325c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2326c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2327c50d8ae3SPaolo Bonzini /* Count self */ 2328c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2329f95eec9bSSean Christopherson 2330f95eec9bSSean Christopherson /* 2331f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2332f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2333f95eec9bSSean Christopherson * !sp->root_count. 2334f95eec9bSSean Christopherson */ 2335f95eec9bSSean Christopherson if (sp->role.invalid) 2336f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2337f95eec9bSSean Christopherson else 2338c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 2339c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(kvm, -1); 2340c50d8ae3SPaolo Bonzini } else { 2341f95eec9bSSean Christopherson /* 2342f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2343f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2344f95eec9bSSean Christopherson */ 2345f95eec9bSSean Christopherson list_del(&sp->link); 2346c50d8ae3SPaolo Bonzini 2347c50d8ae3SPaolo Bonzini /* 2348c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2349c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2350c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2351c50d8ae3SPaolo Bonzini */ 2352527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2353c50d8ae3SPaolo Bonzini } 2354c50d8ae3SPaolo Bonzini 2355c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2356c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2357c50d8ae3SPaolo Bonzini 2358c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2359527d5cd7SSean Christopherson 2360527d5cd7SSean Christopherson /* 2361527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2362527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2363527d5cd7SSean Christopherson */ 2364527d5cd7SSean Christopherson if (zapped_root) 2365527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2366c50d8ae3SPaolo Bonzini return list_unstable; 2367c50d8ae3SPaolo Bonzini } 2368c50d8ae3SPaolo Bonzini 2369c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2370c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2371c50d8ae3SPaolo Bonzini { 2372c50d8ae3SPaolo Bonzini int nr_zapped; 2373c50d8ae3SPaolo Bonzini 2374c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2375c50d8ae3SPaolo Bonzini return nr_zapped; 2376c50d8ae3SPaolo Bonzini } 2377c50d8ae3SPaolo Bonzini 2378c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2379c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2380c50d8ae3SPaolo Bonzini { 2381c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2382c50d8ae3SPaolo Bonzini 2383c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2384c50d8ae3SPaolo Bonzini return; 2385c50d8ae3SPaolo Bonzini 2386c50d8ae3SPaolo Bonzini /* 2387c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2388c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2389c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2390c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2391c50d8ae3SPaolo Bonzini * 2392c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2393c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2394c50d8ae3SPaolo Bonzini */ 2395c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2396c50d8ae3SPaolo Bonzini 2397c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2398c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 2399c50d8ae3SPaolo Bonzini kvm_mmu_free_page(sp); 2400c50d8ae3SPaolo Bonzini } 2401c50d8ae3SPaolo Bonzini } 2402c50d8ae3SPaolo Bonzini 24036b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 24046b82ef2cSSean Christopherson unsigned long nr_to_zap) 2405c50d8ae3SPaolo Bonzini { 24066b82ef2cSSean Christopherson unsigned long total_zapped = 0; 24076b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2408ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 24096b82ef2cSSean Christopherson bool unstable; 24106b82ef2cSSean Christopherson int nr_zapped; 2411c50d8ae3SPaolo Bonzini 2412c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2413ba7888ddSSean Christopherson return 0; 2414c50d8ae3SPaolo Bonzini 24156b82ef2cSSean Christopherson restart: 24168fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 24176b82ef2cSSean Christopherson /* 24186b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 24196b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 24206b82ef2cSSean Christopherson */ 24216b82ef2cSSean Christopherson if (sp->root_count) 24226b82ef2cSSean Christopherson continue; 24236b82ef2cSSean Christopherson 24246b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 24256b82ef2cSSean Christopherson &nr_zapped); 24266b82ef2cSSean Christopherson total_zapped += nr_zapped; 24276b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2428ba7888ddSSean Christopherson break; 2429ba7888ddSSean Christopherson 24306b82ef2cSSean Christopherson if (unstable) 24316b82ef2cSSean Christopherson goto restart; 2432ba7888ddSSean Christopherson } 24336b82ef2cSSean Christopherson 24346b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 24356b82ef2cSSean Christopherson 24366b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 24376b82ef2cSSean Christopherson return total_zapped; 24386b82ef2cSSean Christopherson } 24396b82ef2cSSean Christopherson 2440afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2441afe8d7e6SSean Christopherson { 2442afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2443afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2444afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2445afe8d7e6SSean Christopherson 2446afe8d7e6SSean Christopherson return 0; 2447c50d8ae3SPaolo Bonzini } 2448c50d8ae3SPaolo Bonzini 2449ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2450ba7888ddSSean Christopherson { 24516b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2452ba7888ddSSean Christopherson 24536b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2454ba7888ddSSean Christopherson return 0; 2455ba7888ddSSean Christopherson 24566b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2457ba7888ddSSean Christopherson 24586e6ec584SSean Christopherson /* 24596e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 24606e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 24616e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 24626e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2463c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 24646e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 24656e6ec584SSean Christopherson * page fault paths. 24666e6ec584SSean Christopherson */ 2467ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2468ba7888ddSSean Christopherson return -ENOSPC; 2469ba7888ddSSean Christopherson return 0; 2470ba7888ddSSean Christopherson } 2471ba7888ddSSean Christopherson 2472c50d8ae3SPaolo Bonzini /* 2473c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2474c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2475c50d8ae3SPaolo Bonzini */ 2476c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2477c50d8ae3SPaolo Bonzini { 2478531810caSBen Gardon write_lock(&kvm->mmu_lock); 2479c50d8ae3SPaolo Bonzini 2480c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 24816b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 24826b82ef2cSSean Christopherson goal_nr_mmu_pages); 2483c50d8ae3SPaolo Bonzini 2484c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2485c50d8ae3SPaolo Bonzini } 2486c50d8ae3SPaolo Bonzini 2487c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2488c50d8ae3SPaolo Bonzini 2489531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2490c50d8ae3SPaolo Bonzini } 2491c50d8ae3SPaolo Bonzini 2492c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2493c50d8ae3SPaolo Bonzini { 2494c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2495c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2496c50d8ae3SPaolo Bonzini int r; 2497c50d8ae3SPaolo Bonzini 2498c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2499c50d8ae3SPaolo Bonzini r = 0; 2500531810caSBen Gardon write_lock(&kvm->mmu_lock); 2501c50d8ae3SPaolo Bonzini for_each_gfn_indirect_valid_sp(kvm, sp, gfn) { 2502c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2503c50d8ae3SPaolo Bonzini sp->role.word); 2504c50d8ae3SPaolo Bonzini r = 1; 2505c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2506c50d8ae3SPaolo Bonzini } 2507c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2508531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2509c50d8ae3SPaolo Bonzini 2510c50d8ae3SPaolo Bonzini return r; 2511c50d8ae3SPaolo Bonzini } 251296ad91aeSSean Christopherson 251396ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 251496ad91aeSSean Christopherson { 251596ad91aeSSean Christopherson gpa_t gpa; 251696ad91aeSSean Christopherson int r; 251796ad91aeSSean Christopherson 2518*347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 251996ad91aeSSean Christopherson return 0; 252096ad91aeSSean Christopherson 252196ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 252296ad91aeSSean Christopherson 252396ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 252496ad91aeSSean Christopherson 252596ad91aeSSean Christopherson return r; 252696ad91aeSSean Christopherson } 2527c50d8ae3SPaolo Bonzini 25284d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2529c50d8ae3SPaolo Bonzini { 2530c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 25314d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2532c50d8ae3SPaolo Bonzini sp->unsync = 1; 2533c50d8ae3SPaolo Bonzini 2534c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2535c50d8ae3SPaolo Bonzini } 2536c50d8ae3SPaolo Bonzini 25370337f585SSean Christopherson /* 25380337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 25390337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 25400337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 25410337f585SSean Christopherson * be write-protected. 25420337f585SSean Christopherson */ 25438283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 25442839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2545c50d8ae3SPaolo Bonzini { 2546c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2547ce25681dSSean Christopherson bool locked = false; 2548c50d8ae3SPaolo Bonzini 25490337f585SSean Christopherson /* 25500337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 25510337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 25520337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 25530337f585SSean Christopherson */ 25544d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 25550337f585SSean Christopherson return -EPERM; 2556c50d8ae3SPaolo Bonzini 25570337f585SSean Christopherson /* 25580337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 25590337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 25600337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 25610337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 25620337f585SSean Christopherson */ 25634d78d0b3SBen Gardon for_each_gfn_indirect_valid_sp(kvm, sp, gfn) { 2564c50d8ae3SPaolo Bonzini if (!can_unsync) 25650337f585SSean Christopherson return -EPERM; 2566c50d8ae3SPaolo Bonzini 2567c50d8ae3SPaolo Bonzini if (sp->unsync) 2568c50d8ae3SPaolo Bonzini continue; 2569c50d8ae3SPaolo Bonzini 25702839180cSPaolo Bonzini if (prefetch) 2571f1c4a88cSLai Jiangshan return -EEXIST; 2572f1c4a88cSLai Jiangshan 2573ce25681dSSean Christopherson /* 2574ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2575ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2576ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2577ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2578ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2579ce25681dSSean Christopherson */ 2580ce25681dSSean Christopherson if (!locked) { 2581ce25681dSSean Christopherson locked = true; 25824d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2583ce25681dSSean Christopherson 2584ce25681dSSean Christopherson /* 2585ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2586ce25681dSSean Christopherson * may have since marked the page unsync. A false 2587ce25681dSSean Christopherson * positive on the unprotected check above is not 2588ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2589ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2590ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2591ce25681dSSean Christopherson */ 2592ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2593ce25681dSSean Christopherson continue; 2594ce25681dSSean Christopherson } 2595ce25681dSSean Christopherson 25963bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 25974d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2598c50d8ae3SPaolo Bonzini } 2599ce25681dSSean Christopherson if (locked) 26004d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2601c50d8ae3SPaolo Bonzini 2602c50d8ae3SPaolo Bonzini /* 2603c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2604c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2605c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2606c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2607c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2608c50d8ae3SPaolo Bonzini * following could happen: 2609c50d8ae3SPaolo Bonzini * 2610c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2611c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2612c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2613c50d8ae3SPaolo Bonzini * to be writable 2614c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2615c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2616c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2617c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2618c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2619c50d8ae3SPaolo Bonzini * fault. 2620c50d8ae3SPaolo Bonzini * 2621c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2622c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2623c50d8ae3SPaolo Bonzini * 26240337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 26250337f585SSean Christopherson * false and skips the page. 2626c50d8ae3SPaolo Bonzini * 2627c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2628c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2629c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2630c50d8ae3SPaolo Bonzini * gets used. 2631c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2632c50d8ae3SPaolo Bonzini * as unsync 2633c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2634c50d8ae3SPaolo Bonzini * 2635c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2636264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2637264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2638c50d8ae3SPaolo Bonzini */ 2639c50d8ae3SPaolo Bonzini smp_wmb(); 2640c50d8ae3SPaolo Bonzini 26410337f585SSean Christopherson return 0; 2642c50d8ae3SPaolo Bonzini } 2643c50d8ae3SPaolo Bonzini 26448a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 26458a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2646a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2647799a4190SBen Gardon { 2648d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2649eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2650c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2651c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2652c50d8ae3SPaolo Bonzini bool flush = false; 2653ad67e480SPaolo Bonzini bool wrprot; 2654d786c778SPaolo Bonzini u64 spte; 2655c50d8ae3SPaolo Bonzini 2656a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2657a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 26582839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2659a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2660c50d8ae3SPaolo Bonzini 2661c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2662c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2663c50d8ae3SPaolo Bonzini 2664a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 2665a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2666a54aa15cSSean Christopherson return RET_PF_EMULATE; 2667a54aa15cSSean Christopherson } 2668a54aa15cSSean Christopherson 2669c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2670c50d8ae3SPaolo Bonzini /* 2671c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2672c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2673c50d8ae3SPaolo Bonzini */ 26743bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2675c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2676c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2677c50d8ae3SPaolo Bonzini 2678e47c4aeeSSean Christopherson child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); 2679c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2680c50d8ae3SPaolo Bonzini flush = true; 2681c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2682c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2683c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2684c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2685c50d8ae3SPaolo Bonzini flush = true; 2686c50d8ae3SPaolo Bonzini } else 2687c50d8ae3SPaolo Bonzini was_rmapped = 1; 2688c50d8ae3SPaolo Bonzini } 2689c50d8ae3SPaolo Bonzini 26902839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 26917158bee4SPaolo Bonzini true, host_writable, &spte); 2692d786c778SPaolo Bonzini 2693d786c778SPaolo Bonzini if (*sptep == spte) { 2694d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2695d786c778SPaolo Bonzini } else { 2696d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 26975959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2698c50d8ae3SPaolo Bonzini } 2699c50d8ae3SPaolo Bonzini 2700ad67e480SPaolo Bonzini if (wrprot) { 2701c50d8ae3SPaolo Bonzini if (write_fault) 2702c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2703c50d8ae3SPaolo Bonzini } 2704c50d8ae3SPaolo Bonzini 2705d786c778SPaolo Bonzini if (flush) 2706c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2707c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2708c50d8ae3SPaolo Bonzini 2709c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2710c50d8ae3SPaolo Bonzini 2711c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2712d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 271371f51d2cSMingwei Zhang kvm_update_page_stats(vcpu->kvm, level, 1); 27148a9f566aSDavid Matlack rmap_add(vcpu, slot, sptep, gfn); 2715c50d8ae3SPaolo Bonzini } 2716c50d8ae3SPaolo Bonzini 2717c50d8ae3SPaolo Bonzini return ret; 2718c50d8ae3SPaolo Bonzini } 2719c50d8ae3SPaolo Bonzini 2720c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2721c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2722c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2723c50d8ae3SPaolo Bonzini { 2724c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2725c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 27260a2b64c5SBen Gardon unsigned int access = sp->role.access; 2727c50d8ae3SPaolo Bonzini int i, ret; 2728c50d8ae3SPaolo Bonzini gfn_t gfn; 2729c50d8ae3SPaolo Bonzini 2730c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt); 2731c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2732c50d8ae3SPaolo Bonzini if (!slot) 2733c50d8ae3SPaolo Bonzini return -1; 2734c50d8ae3SPaolo Bonzini 2735c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2736c50d8ae3SPaolo Bonzini if (ret <= 0) 2737c50d8ae3SPaolo Bonzini return -1; 2738c50d8ae3SPaolo Bonzini 2739c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 27408a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2741a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2742c50d8ae3SPaolo Bonzini put_page(pages[i]); 2743c50d8ae3SPaolo Bonzini } 2744c50d8ae3SPaolo Bonzini 2745c50d8ae3SPaolo Bonzini return 0; 2746c50d8ae3SPaolo Bonzini } 2747c50d8ae3SPaolo Bonzini 2748c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2749c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2750c50d8ae3SPaolo Bonzini { 2751c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2752c50d8ae3SPaolo Bonzini int i; 2753c50d8ae3SPaolo Bonzini 2754c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2755c50d8ae3SPaolo Bonzini 2756c50d8ae3SPaolo Bonzini i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); 2757c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2758c50d8ae3SPaolo Bonzini 2759c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2760c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2761c50d8ae3SPaolo Bonzini if (!start) 2762c50d8ae3SPaolo Bonzini continue; 2763c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2764c6cecc4bSSean Christopherson return; 2765c50d8ae3SPaolo Bonzini start = NULL; 2766c50d8ae3SPaolo Bonzini } else if (!start) 2767c50d8ae3SPaolo Bonzini start = spte; 2768c50d8ae3SPaolo Bonzini } 2769c6cecc4bSSean Christopherson if (start) 2770c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2771c50d8ae3SPaolo Bonzini } 2772c50d8ae3SPaolo Bonzini 2773c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2774c50d8ae3SPaolo Bonzini { 2775c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2776c50d8ae3SPaolo Bonzini 277757354682SSean Christopherson sp = sptep_to_sp(sptep); 2778c50d8ae3SPaolo Bonzini 2779c50d8ae3SPaolo Bonzini /* 2780c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2781c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2782c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2783c50d8ae3SPaolo Bonzini */ 2784c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2785c50d8ae3SPaolo Bonzini return; 2786c50d8ae3SPaolo Bonzini 27873bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2788c50d8ae3SPaolo Bonzini return; 2789c50d8ae3SPaolo Bonzini 27904a42d848SDavid Stevens /* 27914a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 27924a42d848SDavid Stevens * accidentally prefetching those addresses. 27934a42d848SDavid Stevens */ 27944a42d848SDavid Stevens if (unlikely(vcpu->kvm->mmu_notifier_count)) 27954a42d848SDavid Stevens return; 27964a42d848SDavid Stevens 2797c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2798c50d8ae3SPaolo Bonzini } 2799c50d8ae3SPaolo Bonzini 28001b6d9d9eSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, 28018ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2802db543216SSean Christopherson { 2803db543216SSean Christopherson unsigned long hva; 280444187235SMingwei Zhang unsigned long flags; 280544187235SMingwei Zhang int level = PG_LEVEL_4K; 280644187235SMingwei Zhang pgd_t pgd; 280744187235SMingwei Zhang p4d_t p4d; 280844187235SMingwei Zhang pud_t pud; 280944187235SMingwei Zhang pmd_t pmd; 2810db543216SSean Christopherson 2811e851265aSSean Christopherson if (!PageCompound(pfn_to_page(pfn)) && !kvm_is_zone_device_pfn(pfn)) 28123bae0459SSean Christopherson return PG_LEVEL_4K; 2813db543216SSean Christopherson 2814293e306eSSean Christopherson /* 2815293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2816293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2817293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2818293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2819293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2820293e306eSSean Christopherson * read-only memslot. 2821293e306eSSean Christopherson */ 2822db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2823db543216SSean Christopherson 282444187235SMingwei Zhang /* 282544187235SMingwei Zhang * Lookup the mapping level in the current mm. The information 282644187235SMingwei Zhang * may become stale soon, but it is safe to use as long as 282744187235SMingwei Zhang * 1) mmu_notifier_retry was checked after taking mmu_lock, and 282844187235SMingwei Zhang * 2) mmu_lock is taken now. 282944187235SMingwei Zhang * 283044187235SMingwei Zhang * We still need to disable IRQs to prevent concurrent tear down 283144187235SMingwei Zhang * of page tables. 283244187235SMingwei Zhang */ 283344187235SMingwei Zhang local_irq_save(flags); 2834db543216SSean Christopherson 283544187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 283644187235SMingwei Zhang if (pgd_none(pgd)) 283744187235SMingwei Zhang goto out; 283844187235SMingwei Zhang 283944187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 284044187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 284144187235SMingwei Zhang goto out; 284244187235SMingwei Zhang 284344187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 284444187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 284544187235SMingwei Zhang goto out; 284644187235SMingwei Zhang 284744187235SMingwei Zhang if (pud_large(pud)) { 284844187235SMingwei Zhang level = PG_LEVEL_1G; 284944187235SMingwei Zhang goto out; 285044187235SMingwei Zhang } 285144187235SMingwei Zhang 285244187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 285344187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 285444187235SMingwei Zhang goto out; 285544187235SMingwei Zhang 285644187235SMingwei Zhang if (pmd_large(pmd)) 285744187235SMingwei Zhang level = PG_LEVEL_2M; 285844187235SMingwei Zhang 285944187235SMingwei Zhang out: 286044187235SMingwei Zhang local_irq_restore(flags); 2861db543216SSean Christopherson return level; 2862db543216SSean Christopherson } 2863db543216SSean Christopherson 28648ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 28658ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 28668ca6f063SBen Gardon kvm_pfn_t pfn, int max_level) 28671b6d9d9eSSean Christopherson { 28681b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 2869ec607a56SPaolo Bonzini int host_level; 28701b6d9d9eSSean Christopherson 28711b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 28721b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 28731b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 28741b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 28751b6d9d9eSSean Christopherson break; 28761b6d9d9eSSean Christopherson } 28771b6d9d9eSSean Christopherson 28781b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 28791b6d9d9eSSean Christopherson return PG_LEVEL_4K; 28801b6d9d9eSSean Christopherson 2881ec607a56SPaolo Bonzini host_level = host_pfn_mapping_level(kvm, gfn, pfn, slot); 2882ec607a56SPaolo Bonzini return min(host_level, max_level); 28831b6d9d9eSSean Christopherson } 28841b6d9d9eSSean Christopherson 288573a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 28860885904dSSean Christopherson { 2887e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 288817eff019SSean Christopherson kvm_pfn_t mask; 28890885904dSSean Christopherson 289073a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 28913cf06612SSean Christopherson 289273a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 289373a3c659SPaolo Bonzini return; 289417eff019SSean Christopherson 289573a3c659SPaolo Bonzini if (is_error_noslot_pfn(fault->pfn) || kvm_is_reserved_pfn(fault->pfn)) 289673a3c659SPaolo Bonzini return; 289717eff019SSean Christopherson 2898e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 289973a3c659SPaolo Bonzini return; 2900293e306eSSean Christopherson 29013cf06612SSean Christopherson /* 29023cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 29033cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 29043cf06612SSean Christopherson */ 290573a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 290673a3c659SPaolo Bonzini fault->gfn, fault->pfn, 290773a3c659SPaolo Bonzini fault->max_level); 290873a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 290973a3c659SPaolo Bonzini return; 29104cd071d1SSean Christopherson 29110885904dSSean Christopherson /* 29124cd071d1SSean Christopherson * mmu_notifier_retry() was successful and mmu_lock is held, so 29134cd071d1SSean Christopherson * the pmd can't be split from under us. 29140885904dSSean Christopherson */ 291573a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 291673a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 291773a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 291873a3c659SPaolo Bonzini fault->pfn &= ~mask; 29190885904dSSean Christopherson } 29200885904dSSean Christopherson 2921536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 2922c50d8ae3SPaolo Bonzini { 2923536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 2924536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 2925c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 2926c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 2927c50d8ae3SPaolo Bonzini /* 2928c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 2929c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 2930c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 2931c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 2932c50d8ae3SPaolo Bonzini * the address. 2933c50d8ae3SPaolo Bonzini */ 2934536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 2935536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 2936536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 2937536f0e6aSPaolo Bonzini fault->goal_level--; 2938c50d8ae3SPaolo Bonzini } 2939c50d8ae3SPaolo Bonzini } 2940c50d8ae3SPaolo Bonzini 294143b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 2942c50d8ae3SPaolo Bonzini { 2943c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 2944c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 294573a3c659SPaolo Bonzini int ret; 294643b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 2947c50d8ae3SPaolo Bonzini 294873a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 29494cd071d1SSean Christopherson 2950f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 295143b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 2952c50d8ae3SPaolo Bonzini /* 2953c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 2954c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 2955c50d8ae3SPaolo Bonzini */ 295673a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 2957536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 2958c50d8ae3SPaolo Bonzini 295943b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 296073a3c659SPaolo Bonzini if (it.level == fault->goal_level) 2961c50d8ae3SPaolo Bonzini break; 2962c50d8ae3SPaolo Bonzini 2963c50d8ae3SPaolo Bonzini drop_large_spte(vcpu, it.sptep); 296403fffc54SSean Christopherson if (is_shadow_present_pte(*it.sptep)) 296503fffc54SSean Christopherson continue; 296603fffc54SSean Christopherson 2967c50d8ae3SPaolo Bonzini sp = kvm_mmu_get_page(vcpu, base_gfn, it.addr, 2968c50d8ae3SPaolo Bonzini it.level - 1, true, ACC_ALL); 2969c50d8ae3SPaolo Bonzini 2970c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 297173a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 297273a3c659SPaolo Bonzini fault->req_level >= it.level) 2973c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 2974c50d8ae3SPaolo Bonzini } 2975c50d8ae3SPaolo Bonzini 2976b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 2977b1a429fbSSean Christopherson return -EFAULT; 2978b1a429fbSSean Christopherson 29798a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 2980a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 298112703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 298212703759SSean Christopherson return ret; 298312703759SSean Christopherson 2984c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 2985c50d8ae3SPaolo Bonzini ++vcpu->stat.pf_fixed; 2986c50d8ae3SPaolo Bonzini return ret; 2987c50d8ae3SPaolo Bonzini } 2988c50d8ae3SPaolo Bonzini 2989c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 2990c50d8ae3SPaolo Bonzini { 2991c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 2992c50d8ae3SPaolo Bonzini } 2993c50d8ae3SPaolo Bonzini 2994c50d8ae3SPaolo Bonzini static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 2995c50d8ae3SPaolo Bonzini { 2996c50d8ae3SPaolo Bonzini /* 2997c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 2998c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 2999c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3000c50d8ae3SPaolo Bonzini */ 3001c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3002c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3003c50d8ae3SPaolo Bonzini 3004c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3005c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3006c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3007c50d8ae3SPaolo Bonzini } 3008c50d8ae3SPaolo Bonzini 3009c50d8ae3SPaolo Bonzini return -EFAULT; 3010c50d8ae3SPaolo Bonzini } 3011c50d8ae3SPaolo Bonzini 30123a13f4feSPaolo Bonzini static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 30133a13f4feSPaolo Bonzini unsigned int access, int *ret_val) 3014c50d8ae3SPaolo Bonzini { 3015c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 30163a13f4feSPaolo Bonzini if (unlikely(is_error_pfn(fault->pfn))) { 30173a13f4feSPaolo Bonzini *ret_val = kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); 3018c50d8ae3SPaolo Bonzini return true; 3019c50d8ae3SPaolo Bonzini } 3020c50d8ae3SPaolo Bonzini 3021e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 30223a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 30233a13f4feSPaolo Bonzini 30243a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3025c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 302630ab5901SSean Christopherson /* 302730ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 302830ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 302986931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 303086931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 303186931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 303286931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 303386931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 303486931ff7SSean Christopherson * the hardware's). 303530ab5901SSean Christopherson */ 30368b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 303786931ff7SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) { 303830ab5901SSean Christopherson *ret_val = RET_PF_EMULATE; 303930ab5901SSean Christopherson return true; 304030ab5901SSean Christopherson } 304130ab5901SSean Christopherson } 3042c50d8ae3SPaolo Bonzini 3043c50d8ae3SPaolo Bonzini return false; 3044c50d8ae3SPaolo Bonzini } 3045c50d8ae3SPaolo Bonzini 30463c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3047c50d8ae3SPaolo Bonzini { 3048c50d8ae3SPaolo Bonzini /* 3049c50d8ae3SPaolo Bonzini * Do not fix the mmio spte with invalid generation number which 3050c50d8ae3SPaolo Bonzini * need to be updated by slow page fault path. 3051c50d8ae3SPaolo Bonzini */ 30523c8ad5a6SPaolo Bonzini if (fault->rsvd) 3053c50d8ae3SPaolo Bonzini return false; 3054c50d8ae3SPaolo Bonzini 3055c50d8ae3SPaolo Bonzini /* See if the page fault is due to an NX violation */ 30563c8ad5a6SPaolo Bonzini if (unlikely(fault->exec && fault->present)) 3057c50d8ae3SPaolo Bonzini return false; 3058c50d8ae3SPaolo Bonzini 3059c50d8ae3SPaolo Bonzini /* 3060c50d8ae3SPaolo Bonzini * #PF can be fast if: 3061c50d8ae3SPaolo Bonzini * 1. The shadow page table entry is not present, which could mean that 3062c50d8ae3SPaolo Bonzini * the fault is potentially caused by access tracking (if enabled). 3063c50d8ae3SPaolo Bonzini * 2. The shadow page table entry is present and the fault 3064c50d8ae3SPaolo Bonzini * is caused by write-protect, that means we just need change the W 3065c50d8ae3SPaolo Bonzini * bit of the spte which can be done out of mmu-lock. 3066c50d8ae3SPaolo Bonzini * 3067c50d8ae3SPaolo Bonzini * However, if access tracking is disabled we know that a non-present 3068c50d8ae3SPaolo Bonzini * page must be a genuine page fault where we have to create a new SPTE. 3069c50d8ae3SPaolo Bonzini * So, if access tracking is disabled, we return true only for write 3070c50d8ae3SPaolo Bonzini * accesses to a present page. 3071c50d8ae3SPaolo Bonzini */ 3072c50d8ae3SPaolo Bonzini 30733c8ad5a6SPaolo Bonzini return shadow_acc_track_mask != 0 || (fault->write && fault->present); 3074c50d8ae3SPaolo Bonzini } 3075c50d8ae3SPaolo Bonzini 3076c50d8ae3SPaolo Bonzini /* 3077c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3078c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3079c50d8ae3SPaolo Bonzini */ 3080c50d8ae3SPaolo Bonzini static bool 3081e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3082c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3083c50d8ae3SPaolo Bonzini { 3084c50d8ae3SPaolo Bonzini /* 3085c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3086c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3087c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3088c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3089c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3090c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3091c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3092c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3093c50d8ae3SPaolo Bonzini * 3094c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3095c50d8ae3SPaolo Bonzini */ 3096c50d8ae3SPaolo Bonzini if (cmpxchg64(sptep, old_spte, new_spte) != old_spte) 3097c50d8ae3SPaolo Bonzini return false; 3098c50d8ae3SPaolo Bonzini 3099e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3100e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3101c50d8ae3SPaolo Bonzini 3102c50d8ae3SPaolo Bonzini return true; 3103c50d8ae3SPaolo Bonzini } 3104c50d8ae3SPaolo Bonzini 31053c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3106c50d8ae3SPaolo Bonzini { 31073c8ad5a6SPaolo Bonzini if (fault->exec) 3108c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3109c50d8ae3SPaolo Bonzini 31103c8ad5a6SPaolo Bonzini if (fault->write) 3111c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3112c50d8ae3SPaolo Bonzini 3113c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3114c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3115c50d8ae3SPaolo Bonzini } 3116c50d8ae3SPaolo Bonzini 3117c50d8ae3SPaolo Bonzini /* 31186e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 31196e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 31206e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 31216e8eb206SDavid Matlack * 31226e8eb206SDavid Matlack * Contract: 31236e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 31246e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 31256e8eb206SDavid Matlack */ 31266e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 31276e8eb206SDavid Matlack { 31286e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 31296e8eb206SDavid Matlack u64 old_spte; 31306e8eb206SDavid Matlack u64 *sptep = NULL; 31316e8eb206SDavid Matlack 31326e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 31336e8eb206SDavid Matlack sptep = iterator.sptep; 31346e8eb206SDavid Matlack *spte = old_spte; 31356e8eb206SDavid Matlack } 31366e8eb206SDavid Matlack 31376e8eb206SDavid Matlack return sptep; 31386e8eb206SDavid Matlack } 31396e8eb206SDavid Matlack 31406e8eb206SDavid Matlack /* 3141c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3142c50d8ae3SPaolo Bonzini */ 31433c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3144c50d8ae3SPaolo Bonzini { 3145c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3146c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3147c50d8ae3SPaolo Bonzini u64 spte = 0ull; 31486e8eb206SDavid Matlack u64 *sptep = NULL; 3149c50d8ae3SPaolo Bonzini uint retry_count = 0; 3150c50d8ae3SPaolo Bonzini 31513c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3152c4371c2aSSean Christopherson return ret; 3153c50d8ae3SPaolo Bonzini 3154c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3155c50d8ae3SPaolo Bonzini 3156c50d8ae3SPaolo Bonzini do { 3157c50d8ae3SPaolo Bonzini u64 new_spte; 3158c50d8ae3SPaolo Bonzini 31596e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 31603c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 31616e8eb206SDavid Matlack else 31623c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3163c50d8ae3SPaolo Bonzini 3164ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3165ec89e643SSean Christopherson break; 3166ec89e643SSean Christopherson 31676e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3168c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3169c50d8ae3SPaolo Bonzini break; 3170c50d8ae3SPaolo Bonzini 3171c50d8ae3SPaolo Bonzini /* 3172c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3173c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3174c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3175c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3176c50d8ae3SPaolo Bonzini * current CPU took the fault. 3177c50d8ae3SPaolo Bonzini * 3178c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3179c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3180c50d8ae3SPaolo Bonzini */ 31813c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3182c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3183c50d8ae3SPaolo Bonzini break; 3184c50d8ae3SPaolo Bonzini } 3185c50d8ae3SPaolo Bonzini 3186c50d8ae3SPaolo Bonzini new_spte = spte; 3187c50d8ae3SPaolo Bonzini 3188c50d8ae3SPaolo Bonzini if (is_access_track_spte(spte)) 3189c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3190c50d8ae3SPaolo Bonzini 3191c50d8ae3SPaolo Bonzini /* 3192c50d8ae3SPaolo Bonzini * Currently, to simplify the code, write-protection can 3193c50d8ae3SPaolo Bonzini * be removed in the fast path only if the SPTE was 3194c50d8ae3SPaolo Bonzini * write-protected for dirty-logging or access tracking. 3195c50d8ae3SPaolo Bonzini */ 31963c8ad5a6SPaolo Bonzini if (fault->write && 3197e6302698SMiaohe Lin spte_can_locklessly_be_made_writable(spte)) { 3198c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3199c50d8ae3SPaolo Bonzini 3200c50d8ae3SPaolo Bonzini /* 320110c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 320210c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 320310c30de0SJunaid Shahid * first page into the dirty-bitmap in 3204c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3205c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3206c50d8ae3SPaolo Bonzini * 3207c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3208c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3209c50d8ae3SPaolo Bonzini */ 321010c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 321110c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3212c50d8ae3SPaolo Bonzini break; 3213c50d8ae3SPaolo Bonzini } 3214c50d8ae3SPaolo Bonzini 3215c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3216c50d8ae3SPaolo Bonzini if (new_spte == spte || 32173c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3218c50d8ae3SPaolo Bonzini break; 3219c50d8ae3SPaolo Bonzini 3220c50d8ae3SPaolo Bonzini /* 3221c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3222c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 32233ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3224c50d8ae3SPaolo Bonzini */ 3225e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3226c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3227c50d8ae3SPaolo Bonzini break; 3228c4371c2aSSean Christopherson } 3229c50d8ae3SPaolo Bonzini 3230c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3231c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3232c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3233c50d8ae3SPaolo Bonzini break; 3234c50d8ae3SPaolo Bonzini } 3235c50d8ae3SPaolo Bonzini 3236c50d8ae3SPaolo Bonzini } while (true); 3237c50d8ae3SPaolo Bonzini 3238f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3239c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3240c50d8ae3SPaolo Bonzini 3241c4371c2aSSean Christopherson return ret; 3242c50d8ae3SPaolo Bonzini } 3243c50d8ae3SPaolo Bonzini 3244c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3245c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3246c50d8ae3SPaolo Bonzini { 3247c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3248c50d8ae3SPaolo Bonzini 3249c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3250c50d8ae3SPaolo Bonzini return; 3251c50d8ae3SPaolo Bonzini 3252e47c4aeeSSean Christopherson sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK); 32539191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 32549191b8f0SPaolo Bonzini return; 325502c00b3aSBen Gardon 3256897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 32576103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 325876eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3259c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3260c50d8ae3SPaolo Bonzini 3261c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3262c50d8ae3SPaolo Bonzini } 3263c50d8ae3SPaolo Bonzini 3264c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 32650c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3266c50d8ae3SPaolo Bonzini ulong roots_to_free) 3267c50d8ae3SPaolo Bonzini { 3268c50d8ae3SPaolo Bonzini int i; 3269c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3270594bef79SPaolo Bonzini bool free_active_root; 3271c50d8ae3SPaolo Bonzini 3272c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3273c50d8ae3SPaolo Bonzini 3274c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3275594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3276594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3277594bef79SPaolo Bonzini 3278594bef79SPaolo Bonzini if (!free_active_root) { 3279c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3280c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3281c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3282c50d8ae3SPaolo Bonzini break; 3283c50d8ae3SPaolo Bonzini 3284c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3285c50d8ae3SPaolo Bonzini return; 3286c50d8ae3SPaolo Bonzini } 3287c50d8ae3SPaolo Bonzini 3288531810caSBen Gardon write_lock(&kvm->mmu_lock); 3289c50d8ae3SPaolo Bonzini 3290c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3291c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 32924d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3293c50d8ae3SPaolo Bonzini &invalid_list); 3294c50d8ae3SPaolo Bonzini 3295c50d8ae3SPaolo Bonzini if (free_active_root) { 3296594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3297b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 329804d45551SSean Christopherson } else if (mmu->pae_root) { 3299c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3300c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3301c834e5e4SSean Christopherson continue; 3302c834e5e4SSean Christopherson 3303c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3304c50d8ae3SPaolo Bonzini &invalid_list); 3305c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3306c50d8ae3SPaolo Bonzini } 3307c50d8ae3SPaolo Bonzini } 3308b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3309b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3310c50d8ae3SPaolo Bonzini } 3311c50d8ae3SPaolo Bonzini 33124d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3313531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3314c50d8ae3SPaolo Bonzini } 3315c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3316c50d8ae3SPaolo Bonzini 33170c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 331825b62c62SSean Christopherson { 331925b62c62SSean Christopherson unsigned long roots_to_free = 0; 332025b62c62SSean Christopherson hpa_t root_hpa; 332125b62c62SSean Christopherson int i; 332225b62c62SSean Christopherson 332325b62c62SSean Christopherson /* 332425b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 332525b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 332625b62c62SSean Christopherson */ 33277a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 332825b62c62SSean Christopherson 332925b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 333025b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 333125b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 333225b62c62SSean Christopherson continue; 333325b62c62SSean Christopherson 333425b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 333525b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 333625b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 333725b62c62SSean Christopherson } 333825b62c62SSean Christopherson 33390c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 334025b62c62SSean Christopherson } 334125b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 334225b62c62SSean Christopherson 334325b62c62SSean Christopherson 3344c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3345c50d8ae3SPaolo Bonzini { 3346c50d8ae3SPaolo Bonzini int ret = 0; 3347c50d8ae3SPaolo Bonzini 3348995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3349c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3350c50d8ae3SPaolo Bonzini ret = 1; 3351c50d8ae3SPaolo Bonzini } 3352c50d8ae3SPaolo Bonzini 3353c50d8ae3SPaolo Bonzini return ret; 3354c50d8ae3SPaolo Bonzini } 3355c50d8ae3SPaolo Bonzini 33568123f265SSean Christopherson static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva, 33578123f265SSean Christopherson u8 level, bool direct) 3358c50d8ae3SPaolo Bonzini { 3359c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 33608123f265SSean Christopherson 33618123f265SSean Christopherson sp = kvm_mmu_get_page(vcpu, gfn, gva, level, direct, ACC_ALL); 33628123f265SSean Christopherson ++sp->root_count; 33638123f265SSean Christopherson 33648123f265SSean Christopherson return __pa(sp->spt); 33658123f265SSean Christopherson } 33668123f265SSean Christopherson 33678123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 33688123f265SSean Christopherson { 3369b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3370a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 33718123f265SSean Christopherson hpa_t root; 3372c50d8ae3SPaolo Bonzini unsigned i; 33734a38162eSPaolo Bonzini int r; 33744a38162eSPaolo Bonzini 33754a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 33764a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 33774a38162eSPaolo Bonzini if (r < 0) 33784a38162eSPaolo Bonzini goto out_unlock; 3379c50d8ae3SPaolo Bonzini 3380897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 338102c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3382b9e5603cSPaolo Bonzini mmu->root.hpa = root; 338302c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 33846e6ec584SSean Christopherson root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true); 3385b9e5603cSPaolo Bonzini mmu->root.hpa = root; 33868123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 33874a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 33884a38162eSPaolo Bonzini r = -EIO; 33894a38162eSPaolo Bonzini goto out_unlock; 33904a38162eSPaolo Bonzini } 339173ad1606SSean Christopherson 3392c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3393c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3394c50d8ae3SPaolo Bonzini 33958123f265SSean Christopherson root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 33968123f265SSean Christopherson i << 30, PT32_ROOT_LEVEL, true); 339717e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 339817e368d9SSean Christopherson shadow_me_mask; 3399c50d8ae3SPaolo Bonzini } 3400b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 340173ad1606SSean Christopherson } else { 340273ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 34034a38162eSPaolo Bonzini r = -EIO; 34044a38162eSPaolo Bonzini goto out_unlock; 340573ad1606SSean Christopherson } 34063651c7fcSSean Christopherson 3407b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3408b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 34094a38162eSPaolo Bonzini out_unlock: 34104a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 34114a38162eSPaolo Bonzini return r; 3412c50d8ae3SPaolo Bonzini } 3413c50d8ae3SPaolo Bonzini 34141e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 34151e76a3ceSDavid Stevens { 34161e76a3ceSDavid Stevens struct kvm_memslots *slots; 34171e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3418a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 34191e76a3ceSDavid Stevens 34201e76a3ceSDavid Stevens /* 34211e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 34221e76a3ceSDavid Stevens * taking the lock. 34231e76a3ceSDavid Stevens */ 34241e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34251e76a3ceSDavid Stevens return 0; 34261e76a3ceSDavid Stevens 34271e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 34281e76a3ceSDavid Stevens 34291e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 34301e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34311e76a3ceSDavid Stevens goto out_unlock; 34321e76a3ceSDavid Stevens 34331e76a3ceSDavid Stevens /* 34341e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 34351e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 34361e76a3ceSDavid Stevens */ 34371e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 34381e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 34391e76a3ceSDavid Stevens goto out_success; 34401e76a3ceSDavid Stevens 34411e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 34421e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3443a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 34441e76a3ceSDavid Stevens /* 34451e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 34461e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 34471e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 34481e76a3ceSDavid Stevens * failure to avoid having to track which allocations 34491e76a3ceSDavid Stevens * were made now versus when the memslot was created. 34501e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 34511e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 34521e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 34531e76a3ceSDavid Stevens */ 34541e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 34551e76a3ceSDavid Stevens if (r) 34561e76a3ceSDavid Stevens goto out_unlock; 34571e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 34581e76a3ceSDavid Stevens if (r) 34591e76a3ceSDavid Stevens goto out_unlock; 34601e76a3ceSDavid Stevens } 34611e76a3ceSDavid Stevens } 34621e76a3ceSDavid Stevens 34631e76a3ceSDavid Stevens /* 34641e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 34651e76a3ceSDavid Stevens * all the related pointers are set. 34661e76a3ceSDavid Stevens */ 34671e76a3ceSDavid Stevens out_success: 34681e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 34691e76a3ceSDavid Stevens 34701e76a3ceSDavid Stevens out_unlock: 34711e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 34721e76a3ceSDavid Stevens return r; 34731e76a3ceSDavid Stevens } 34741e76a3ceSDavid Stevens 3475c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3476c50d8ae3SPaolo Bonzini { 3477b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 34786e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3479be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 34808123f265SSean Christopherson hpa_t root; 34814a38162eSPaolo Bonzini unsigned i; 34824a38162eSPaolo Bonzini int r; 3483c50d8ae3SPaolo Bonzini 3484b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3485be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3486c50d8ae3SPaolo Bonzini 3487c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3488c50d8ae3SPaolo Bonzini return 1; 3489c50d8ae3SPaolo Bonzini 3490c50d8ae3SPaolo Bonzini /* 34914a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 34924a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 34934a38162eSPaolo Bonzini */ 34944d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 34956e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 34966e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 34976e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 34986e0918aeSSean Christopherson continue; 34996e0918aeSSean Christopherson 35006e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 35016e0918aeSSean Christopherson return 1; 35026e0918aeSSean Christopherson } 35036e0918aeSSean Christopherson } 35046e0918aeSSean Christopherson 35051e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3506d501f747SBen Gardon if (r) 3507d501f747SBen Gardon return r; 3508d501f747SBen Gardon 35094a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35104a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35114a38162eSPaolo Bonzini if (r < 0) 35124a38162eSPaolo Bonzini goto out_unlock; 35134a38162eSPaolo Bonzini 3514c50d8ae3SPaolo Bonzini /* 3515c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3516c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3517c50d8ae3SPaolo Bonzini */ 35184d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 35198123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 3520a972e29cSPaolo Bonzini mmu->root_role.level, false); 3521b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3522be01e8e2SSean Christopherson goto set_root_pgd; 3523c50d8ae3SPaolo Bonzini } 3524c50d8ae3SPaolo Bonzini 35254a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35264a38162eSPaolo Bonzini r = -EIO; 35274a38162eSPaolo Bonzini goto out_unlock; 35284a38162eSPaolo Bonzini } 352973ad1606SSean Christopherson 3530c50d8ae3SPaolo Bonzini /* 3531c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3532c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3533c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3534c50d8ae3SPaolo Bonzini */ 353517e368d9SSean Christopherson pm_mask = PT_PRESENT_MASK | shadow_me_mask; 3536a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3537c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3538c50d8ae3SPaolo Bonzini 353903ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 35404a38162eSPaolo Bonzini r = -EIO; 35414a38162eSPaolo Bonzini goto out_unlock; 35424a38162eSPaolo Bonzini } 354303ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3544cb0f722aSWei Huang 3545a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3546cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3547cb0f722aSWei Huang r = -EIO; 3548cb0f722aSWei Huang goto out_unlock; 3549cb0f722aSWei Huang } 3550cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3551cb0f722aSWei Huang } 355204d45551SSean Christopherson } 355304d45551SSean Christopherson 3554c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3555c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 35566e6ec584SSean Christopherson 35574d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 35586e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3559c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3560c50d8ae3SPaolo Bonzini continue; 3561c50d8ae3SPaolo Bonzini } 35626e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3563c50d8ae3SPaolo Bonzini } 3564c50d8ae3SPaolo Bonzini 35658123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, i << 30, 35668123f265SSean Christopherson PT32_ROOT_LEVEL, false); 3567b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3568c50d8ae3SPaolo Bonzini } 3569c50d8ae3SPaolo Bonzini 3570a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3571b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3572a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3573b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3574ba0a194fSSean Christopherson else 3575b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3576c50d8ae3SPaolo Bonzini 3577be01e8e2SSean Christopherson set_root_pgd: 3578b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 35794a38162eSPaolo Bonzini out_unlock: 35804a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3581c50d8ae3SPaolo Bonzini 3582c6c937d6SLike Xu return r; 3583c50d8ae3SPaolo Bonzini } 3584c50d8ae3SPaolo Bonzini 3585748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3586c50d8ae3SPaolo Bonzini { 3587748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3588a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3589cb0f722aSWei Huang u64 *pml5_root = NULL; 3590cb0f722aSWei Huang u64 *pml4_root = NULL; 3591cb0f722aSWei Huang u64 *pae_root; 3592748e52b9SSean Christopherson 3593748e52b9SSean Christopherson /* 3594748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3595748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3596748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3597748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3598748e52b9SSean Christopherson */ 3599*347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3600*347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3601a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3602748e52b9SSean Christopherson return 0; 3603748e52b9SSean Christopherson 3604a717a780SSean Christopherson /* 3605a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3606a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3607a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3608a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3609a717a780SSean Christopherson * prior MMU would also have required pml5. 3610a717a780SSean Christopherson */ 3611a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3612748e52b9SSean Christopherson return 0; 3613748e52b9SSean Christopherson 3614748e52b9SSean Christopherson /* 3615748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3616748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3617748e52b9SSean Christopherson */ 3618cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3619a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3620748e52b9SSean Christopherson return -EIO; 3621748e52b9SSean Christopherson 36224a98623dSSean Christopherson /* 36234a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 36244a98623dSSean Christopherson * doesn't need to be decrypted. 36254a98623dSSean Christopherson */ 3626748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3627748e52b9SSean Christopherson if (!pae_root) 3628748e52b9SSean Christopherson return -ENOMEM; 3629748e52b9SSean Christopherson 3630cb0f722aSWei Huang #ifdef CONFIG_X86_64 363103ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3632cb0f722aSWei Huang if (!pml4_root) 3633cb0f722aSWei Huang goto err_pml4; 3634cb0f722aSWei Huang 3635a717a780SSean Christopherson if (need_pml5) { 3636cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3637cb0f722aSWei Huang if (!pml5_root) 3638cb0f722aSWei Huang goto err_pml5; 3639748e52b9SSean Christopherson } 3640cb0f722aSWei Huang #endif 3641748e52b9SSean Christopherson 3642748e52b9SSean Christopherson mmu->pae_root = pae_root; 364303ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3644cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3645748e52b9SSean Christopherson 3646748e52b9SSean Christopherson return 0; 3647cb0f722aSWei Huang 3648cb0f722aSWei Huang #ifdef CONFIG_X86_64 3649cb0f722aSWei Huang err_pml5: 3650cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3651cb0f722aSWei Huang err_pml4: 3652cb0f722aSWei Huang free_page((unsigned long)pae_root); 3653cb0f722aSWei Huang return -ENOMEM; 3654cb0f722aSWei Huang #endif 3655c50d8ae3SPaolo Bonzini } 3656c50d8ae3SPaolo Bonzini 3657264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3658264d3dc1SLai Jiangshan { 3659264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3660264d3dc1SLai Jiangshan 366161b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 366261b05a9fSLai Jiangshan return false; 366361b05a9fSLai Jiangshan 3664264d3dc1SLai Jiangshan /* 3665264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3666264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3667264d3dc1SLai Jiangshan * 3668264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3669264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3670264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3671264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3672264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3673264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3674264d3dc1SLai Jiangshan * requirement isn't satisfied. 3675264d3dc1SLai Jiangshan */ 3676264d3dc1SLai Jiangshan smp_rmb(); 3677264d3dc1SLai Jiangshan sp = to_shadow_page(root); 36785d6a3221SSean Christopherson 36795d6a3221SSean Christopherson /* 36805d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 36815d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 36825d6a3221SSean Christopherson */ 36835d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 36845d6a3221SSean Christopherson return false; 36855d6a3221SSean Christopherson 3686264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3687264d3dc1SLai Jiangshan return true; 3688264d3dc1SLai Jiangshan 3689264d3dc1SLai Jiangshan return false; 3690264d3dc1SLai Jiangshan } 3691264d3dc1SLai Jiangshan 3692c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3693c50d8ae3SPaolo Bonzini { 3694c50d8ae3SPaolo Bonzini int i; 3695c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3696c50d8ae3SPaolo Bonzini 3697*347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3698c50d8ae3SPaolo Bonzini return; 3699c50d8ae3SPaolo Bonzini 3700b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3701c50d8ae3SPaolo Bonzini return; 3702c50d8ae3SPaolo Bonzini 3703c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3704c50d8ae3SPaolo Bonzini 37054d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3706b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3707e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3708c50d8ae3SPaolo Bonzini 3709264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3710c50d8ae3SPaolo Bonzini return; 3711c50d8ae3SPaolo Bonzini 3712531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 371365855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3714531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3715c50d8ae3SPaolo Bonzini return; 3716c50d8ae3SPaolo Bonzini } 3717c50d8ae3SPaolo Bonzini 3718531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3719c50d8ae3SPaolo Bonzini 3720c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3721c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3722c50d8ae3SPaolo Bonzini 3723c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 3724c50d8ae3SPaolo Bonzini root &= PT64_BASE_ADDR_MASK; 3725e47c4aeeSSean Christopherson sp = to_shadow_page(root); 372665855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3727c50d8ae3SPaolo Bonzini } 3728c50d8ae3SPaolo Bonzini } 3729c50d8ae3SPaolo Bonzini 3730531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3731c50d8ae3SPaolo Bonzini } 3732c50d8ae3SPaolo Bonzini 373361b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 373461b05a9fSLai Jiangshan { 373561b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 373661b05a9fSLai Jiangshan int i; 373761b05a9fSLai Jiangshan 373861b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 373961b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 374061b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 374161b05a9fSLai Jiangshan 374261b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 37430c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 374461b05a9fSLai Jiangshan } 374561b05a9fSLai Jiangshan 37461f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 37475b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3748c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3749c50d8ae3SPaolo Bonzini { 3750c50d8ae3SPaolo Bonzini if (exception) 3751c50d8ae3SPaolo Bonzini exception->error_code = 0; 3752c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3753c50d8ae3SPaolo Bonzini } 3754c50d8ae3SPaolo Bonzini 3755c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3756c50d8ae3SPaolo Bonzini { 3757c50d8ae3SPaolo Bonzini /* 3758c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3759c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3760c50d8ae3SPaolo Bonzini */ 3761c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3762c50d8ae3SPaolo Bonzini return false; 3763c50d8ae3SPaolo Bonzini 3764c50d8ae3SPaolo Bonzini if (direct) 3765c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3766c50d8ae3SPaolo Bonzini 3767c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3768c50d8ae3SPaolo Bonzini } 3769c50d8ae3SPaolo Bonzini 377095fb5b02SBen Gardon /* 377195fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 377295fb5b02SBen Gardon * That SPTE may be non-present. 3773c5c8c7c5SDavid Matlack * 3774c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 377595fb5b02SBen Gardon */ 377639b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3777c50d8ae3SPaolo Bonzini { 3778c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 37792aa07893SSean Christopherson int leaf = -1; 378095fb5b02SBen Gardon u64 spte; 3781c50d8ae3SPaolo Bonzini 378239b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 378339b4d43eSSean Christopherson *root_level = iterator.level; 3784c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3785c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 378695fb5b02SBen Gardon leaf = iterator.level; 3787c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3788c50d8ae3SPaolo Bonzini 3789dde81f94SSean Christopherson sptes[leaf] = spte; 379095fb5b02SBen Gardon } 379195fb5b02SBen Gardon 379295fb5b02SBen Gardon return leaf; 379395fb5b02SBen Gardon } 379495fb5b02SBen Gardon 37959aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 379695fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 379795fb5b02SBen Gardon { 3798dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 379995fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 380039b4d43eSSean Christopherson int root, leaf, level; 380195fb5b02SBen Gardon bool reserved = false; 380295fb5b02SBen Gardon 3803c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3804c5c8c7c5SDavid Matlack 380563c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 380639b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 380795fb5b02SBen Gardon else 380839b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 380995fb5b02SBen Gardon 3810c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 3811c5c8c7c5SDavid Matlack 38122aa07893SSean Christopherson if (unlikely(leaf < 0)) { 38132aa07893SSean Christopherson *sptep = 0ull; 38142aa07893SSean Christopherson return reserved; 38152aa07893SSean Christopherson } 38162aa07893SSean Christopherson 38179aa41879SSean Christopherson *sptep = sptes[leaf]; 38189aa41879SSean Christopherson 38199aa41879SSean Christopherson /* 38209aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 38219aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 38229aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 38239aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 38249aa41879SSean Christopherson */ 38259aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 38269aa41879SSean Christopherson leaf++; 382795fb5b02SBen Gardon 382895fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 382995fb5b02SBen Gardon 38309aa41879SSean Christopherson for (level = root; level >= leaf; level--) 3831961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 3832c50d8ae3SPaolo Bonzini 3833c50d8ae3SPaolo Bonzini if (reserved) { 3834bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 3835c50d8ae3SPaolo Bonzini __func__, addr); 383695fb5b02SBen Gardon for (level = root; level >= leaf; level--) 3837bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 3838bb4cdf3aSSean Christopherson sptes[level], level, 3839961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 3840c50d8ae3SPaolo Bonzini } 3841ddce6208SSean Christopherson 3842c50d8ae3SPaolo Bonzini return reserved; 3843c50d8ae3SPaolo Bonzini } 3844c50d8ae3SPaolo Bonzini 3845c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3846c50d8ae3SPaolo Bonzini { 3847c50d8ae3SPaolo Bonzini u64 spte; 3848c50d8ae3SPaolo Bonzini bool reserved; 3849c50d8ae3SPaolo Bonzini 3850c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 3851c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3852c50d8ae3SPaolo Bonzini 385395fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 3854c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 3855c50d8ae3SPaolo Bonzini return -EINVAL; 3856c50d8ae3SPaolo Bonzini 3857c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 3858c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 38590a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 3860c50d8ae3SPaolo Bonzini 3861c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 3862c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 3863c50d8ae3SPaolo Bonzini 3864c50d8ae3SPaolo Bonzini if (direct) 3865c50d8ae3SPaolo Bonzini addr = 0; 3866c50d8ae3SPaolo Bonzini 3867c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 3868c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 3869c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3870c50d8ae3SPaolo Bonzini } 3871c50d8ae3SPaolo Bonzini 3872c50d8ae3SPaolo Bonzini /* 3873c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 3874c50d8ae3SPaolo Bonzini * the address. 3875c50d8ae3SPaolo Bonzini */ 3876c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3877c50d8ae3SPaolo Bonzini } 3878c50d8ae3SPaolo Bonzini 3879c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 3880b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 3881c50d8ae3SPaolo Bonzini { 3882b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 3883c50d8ae3SPaolo Bonzini return false; 3884c50d8ae3SPaolo Bonzini 3885b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 3886c50d8ae3SPaolo Bonzini return false; 3887c50d8ae3SPaolo Bonzini 3888c50d8ae3SPaolo Bonzini /* 3889c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 3890c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 3891c50d8ae3SPaolo Bonzini */ 38929d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 3893c50d8ae3SPaolo Bonzini return true; 3894c50d8ae3SPaolo Bonzini 3895c50d8ae3SPaolo Bonzini return false; 3896c50d8ae3SPaolo Bonzini } 3897c50d8ae3SPaolo Bonzini 3898c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 3899c50d8ae3SPaolo Bonzini { 3900c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 3901c50d8ae3SPaolo Bonzini u64 spte; 3902c50d8ae3SPaolo Bonzini 3903c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 39043e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 3905c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 3906c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3907c50d8ae3SPaolo Bonzini } 3908c50d8ae3SPaolo Bonzini 39096f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 39106f3c1fc5SLiang Zhang { 39116f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 39126f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 39136f3c1fc5SLiang Zhang 39146f3c1fc5SLiang Zhang if (id << 12 == 0) 39156f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 39166f3c1fc5SLiang Zhang 39176f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 39186f3c1fc5SLiang Zhang } 39196f3c1fc5SLiang Zhang 3920e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 39219f1a8526SSean Christopherson gfn_t gfn) 3922c50d8ae3SPaolo Bonzini { 3923c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 3924c50d8ae3SPaolo Bonzini 39256f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 3926c50d8ae3SPaolo Bonzini arch.gfn = gfn; 3927*347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 3928d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 3929c50d8ae3SPaolo Bonzini 39309f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 39319f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 3932c50d8ae3SPaolo Bonzini } 3933c50d8ae3SPaolo Bonzini 39343647cd04SPaolo Bonzini static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, int *r) 3935c50d8ae3SPaolo Bonzini { 3936e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 3937c50d8ae3SPaolo Bonzini bool async; 3938c50d8ae3SPaolo Bonzini 3939e0c37868SSean Christopherson /* 3940e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 3941e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 3942e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 3943e0c37868SSean Christopherson */ 3944e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 39458f32d5e5SMaxim Levitsky goto out_retry; 3946e0c37868SSean Christopherson 39479cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 3948c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 39499cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 3950e710c5f6SDavid Matlack fault->slot = NULL; 39513647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 39523647cd04SPaolo Bonzini fault->map_writable = false; 3953c50d8ae3SPaolo Bonzini return false; 3954c50d8ae3SPaolo Bonzini } 39559cc13d60SMaxim Levitsky /* 39569cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 39579cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 39589cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 39599cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 39609cc13d60SMaxim Levitsky */ 39619cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 39629cc13d60SMaxim Levitsky !kvm_apicv_activated(vcpu->kvm)) { 39639cc13d60SMaxim Levitsky *r = RET_PF_EMULATE; 39649cc13d60SMaxim Levitsky return true; 39659cc13d60SMaxim Levitsky } 39669cc13d60SMaxim Levitsky } 3967c50d8ae3SPaolo Bonzini 3968c50d8ae3SPaolo Bonzini async = false; 39693647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, 39703647cd04SPaolo Bonzini fault->write, &fault->map_writable, 39713647cd04SPaolo Bonzini &fault->hva); 3972c50d8ae3SPaolo Bonzini if (!async) 3973c50d8ae3SPaolo Bonzini return false; /* *pfn has correct page already */ 3974c50d8ae3SPaolo Bonzini 39752839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 39763647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 39773647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 39783647cd04SPaolo Bonzini trace_kvm_async_pf_doublefault(fault->addr, fault->gfn); 3979c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 39808f32d5e5SMaxim Levitsky goto out_retry; 39813647cd04SPaolo Bonzini } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) 39828f32d5e5SMaxim Levitsky goto out_retry; 3983c50d8ae3SPaolo Bonzini } 3984c50d8ae3SPaolo Bonzini 39853647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, 39863647cd04SPaolo Bonzini fault->write, &fault->map_writable, 39873647cd04SPaolo Bonzini &fault->hva); 3988a7cc099fSAndrei Vagin return false; 39898f32d5e5SMaxim Levitsky 39908f32d5e5SMaxim Levitsky out_retry: 39918f32d5e5SMaxim Levitsky *r = RET_PF_RETRY; 39928f32d5e5SMaxim Levitsky return true; 3993c50d8ae3SPaolo Bonzini } 3994c50d8ae3SPaolo Bonzini 3995a955cad8SSean Christopherson /* 3996a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 3997a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 3998a955cad8SSean Christopherson */ 3999a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4000a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 4001a955cad8SSean Christopherson { 4002b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 400318c841e1SSean Christopherson 400418c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 400518c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 400618c841e1SSean Christopherson return true; 400718c841e1SSean Christopherson 400818c841e1SSean Christopherson /* 400918c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 401018c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 401118c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 401218c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 401318c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 401418c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 401518c841e1SSean Christopherson */ 4016527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4017a955cad8SSean Christopherson return true; 4018a955cad8SSean Christopherson 4019a955cad8SSean Christopherson return fault->slot && 4020a955cad8SSean Christopherson mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4021a955cad8SSean Christopherson } 4022a955cad8SSean Christopherson 40234326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4024c50d8ae3SPaolo Bonzini { 402563c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4026c50d8ae3SPaolo Bonzini 40270f90e1c1SSean Christopherson unsigned long mmu_seq; 402883f06fa7SSean Christopherson int r; 4029c50d8ae3SPaolo Bonzini 40303c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4031e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4032e710c5f6SDavid Matlack 4033b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4034c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4035c50d8ae3SPaolo Bonzini 40363c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4037c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4038c4371c2aSSean Christopherson return r; 403983291445SSean Christopherson 4040378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4041c50d8ae3SPaolo Bonzini if (r) 4042c50d8ae3SPaolo Bonzini return r; 4043c50d8ae3SPaolo Bonzini 4044367fd790SSean Christopherson mmu_seq = vcpu->kvm->mmu_notifier_seq; 4045367fd790SSean Christopherson smp_rmb(); 4046367fd790SSean Christopherson 40473647cd04SPaolo Bonzini if (kvm_faultin_pfn(vcpu, fault, &r)) 40488f32d5e5SMaxim Levitsky return r; 4049367fd790SSean Christopherson 40503a13f4feSPaolo Bonzini if (handle_abnormal_pfn(vcpu, fault, ACC_ALL, &r)) 4051367fd790SSean Christopherson return r; 4052367fd790SSean Christopherson 4053367fd790SSean Christopherson r = RET_PF_RETRY; 4054a2855afcSBen Gardon 40550b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4056a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4057a2855afcSBen Gardon else 4058531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4059a2855afcSBen Gardon 4060a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4061367fd790SSean Christopherson goto out_unlock; 4062a955cad8SSean Christopherson 40637bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 40647bd7ded6SSean Christopherson if (r) 4065367fd790SSean Christopherson goto out_unlock; 4066bb18842eSBen Gardon 40670b873fd7SDavid Matlack if (is_tdp_mmu_fault) 40682f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4069bb18842eSBen Gardon else 407043b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 40710f90e1c1SSean Christopherson 4072367fd790SSean Christopherson out_unlock: 40730b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4074a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4075a2855afcSBen Gardon else 4076531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 40773647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4078367fd790SSean Christopherson return r; 4079c50d8ae3SPaolo Bonzini } 4080c50d8ae3SPaolo Bonzini 4081c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4082c501040aSPaolo Bonzini struct kvm_page_fault *fault) 40830f90e1c1SSean Christopherson { 40844326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 40850f90e1c1SSean Christopherson 40860f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 40874326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 40884326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 40890f90e1c1SSean Christopherson } 40900f90e1c1SSean Christopherson 4091c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4092c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4093c50d8ae3SPaolo Bonzini { 4094c50d8ae3SPaolo Bonzini int r = 1; 40959ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4096c50d8ae3SPaolo Bonzini 4097736c291cSSean Christopherson #ifndef CONFIG_X86_64 4098736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4099736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4100736c291cSSean Christopherson return -EFAULT; 4101736c291cSSean Christopherson #endif 4102736c291cSSean Christopherson 4103c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 41049ce372b3SVitaly Kuznetsov if (!flags) { 4105c50d8ae3SPaolo Bonzini trace_kvm_page_fault(fault_address, error_code); 4106c50d8ae3SPaolo Bonzini 4107c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4108c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4109c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4110c50d8ae3SPaolo Bonzini insn_len); 41119ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 411268fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4113c50d8ae3SPaolo Bonzini local_irq_disable(); 41146bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4115c50d8ae3SPaolo Bonzini local_irq_enable(); 41169ce372b3SVitaly Kuznetsov } else { 41179ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4118c50d8ae3SPaolo Bonzini } 41199ce372b3SVitaly Kuznetsov 4120c50d8ae3SPaolo Bonzini return r; 4121c50d8ae3SPaolo Bonzini } 4122c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4123c50d8ae3SPaolo Bonzini 4124c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4125c50d8ae3SPaolo Bonzini { 41264326e57eSPaolo Bonzini while (fault->max_level > PG_LEVEL_4K) { 41274326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 41284326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4129c50d8ae3SPaolo Bonzini 4130cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4131cb9b88c6SSean Christopherson break; 41324326e57eSPaolo Bonzini 41334326e57eSPaolo Bonzini --fault->max_level; 4134c50d8ae3SPaolo Bonzini } 4135c50d8ae3SPaolo Bonzini 41364326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4137c50d8ae3SPaolo Bonzini } 4138c50d8ae3SPaolo Bonzini 413984a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4140c50d8ae3SPaolo Bonzini { 4141c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4142c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4143c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 41445efac074SPaolo Bonzini context->invlpg = NULL; 4145c50d8ae3SPaolo Bonzini } 4146c50d8ae3SPaolo Bonzini 4147be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 41480be44352SSean Christopherson union kvm_mmu_page_role role) 41490be44352SSean Christopherson { 4150be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 41515499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4152e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 41530be44352SSean Christopherson } 41540be44352SSean Christopherson 4155c50d8ae3SPaolo Bonzini /* 41565499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 41575499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 41585499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 41595499ea73SPaolo Bonzini * true is returned. 41605499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 41615499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4162c50d8ae3SPaolo Bonzini */ 41635499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 41645499ea73SPaolo Bonzini gpa_t new_pgd, 4165c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4166c50d8ae3SPaolo Bonzini { 4167c50d8ae3SPaolo Bonzini uint i; 4168c50d8ae3SPaolo Bonzini 4169b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 41700be44352SSean Christopherson return true; 41710be44352SSean Christopherson 4172c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 41735499ea73SPaolo Bonzini /* 41745499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 41755499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 41765499ea73SPaolo Bonzini * 0 C 1 2 3 41775499ea73SPaolo Bonzini * 1 C 0 2 3 41785499ea73SPaolo Bonzini * 2 C 0 1 3 41795499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 41805499ea73SPaolo Bonzini */ 4181b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4182b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 41835499ea73SPaolo Bonzini return true; 4184c50d8ae3SPaolo Bonzini } 4185c50d8ae3SPaolo Bonzini 41865499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 41875499ea73SPaolo Bonzini return false; 4188c50d8ae3SPaolo Bonzini } 4189c50d8ae3SPaolo Bonzini 4190c50d8ae3SPaolo Bonzini /* 41915499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 41925499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 41935499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 41945499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 41955499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 41965499ea73SPaolo Bonzini */ 41975499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 41985499ea73SPaolo Bonzini gpa_t new_pgd, 41995499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 42005499ea73SPaolo Bonzini { 42015499ea73SPaolo Bonzini uint i; 42025499ea73SPaolo Bonzini 42035499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 42045499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 42055499ea73SPaolo Bonzini goto hit; 42065499ea73SPaolo Bonzini 42075499ea73SPaolo Bonzini return false; 42085499ea73SPaolo Bonzini 42095499ea73SPaolo Bonzini hit: 42105499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 42115499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 42125499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 42135499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 42145499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 42155499ea73SPaolo Bonzini return true; 42165499ea73SPaolo Bonzini } 42175499ea73SPaolo Bonzini 42185499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 42195499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 42205499ea73SPaolo Bonzini { 42215499ea73SPaolo Bonzini /* 42225499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4223c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4224c50d8ae3SPaolo Bonzini * later if necessary. 4225c50d8ae3SPaolo Bonzini */ 42265499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 42275499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4228c50d8ae3SPaolo Bonzini 42295499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 42305499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 42315499ea73SPaolo Bonzini else 42325499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4233c50d8ae3SPaolo Bonzini } 4234c50d8ae3SPaolo Bonzini 4235d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4236c50d8ae3SPaolo Bonzini { 42370c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 42387a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 42390c1c92f1SPaolo Bonzini 42405499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 42415499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4242b869855bSSean Christopherson return; 4243c50d8ae3SPaolo Bonzini } 4244c50d8ae3SPaolo Bonzini 4245c50d8ae3SPaolo Bonzini /* 4246b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4247b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4248527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4249527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4250b869855bSSean Christopherson */ 4251b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4252b869855bSSean Christopherson 4253b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4254b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4255b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4256b5129100SSean Christopherson } 4257b869855bSSean Christopherson 4258b869855bSSean Christopherson /* 4259b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4260b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4261b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4262b869855bSSean Christopherson * the shadow page tables. 4263c50d8ae3SPaolo Bonzini */ 4264c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4265c50d8ae3SPaolo Bonzini 4266daa5b6c1SBen Gardon /* 4267daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4268daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4269daa5b6c1SBen Gardon */ 4270daa5b6c1SBen Gardon if (!new_role.direct) 4271daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4272b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4273c50d8ae3SPaolo Bonzini } 4274be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4275c50d8ae3SPaolo Bonzini 4276c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4277c50d8ae3SPaolo Bonzini { 4278c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4279c50d8ae3SPaolo Bonzini } 4280c50d8ae3SPaolo Bonzini 4281c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4282c3e5e415SLai Jiangshan unsigned int access) 4283c50d8ae3SPaolo Bonzini { 4284c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4285c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4286c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4287c50d8ae3SPaolo Bonzini return true; 4288c50d8ae3SPaolo Bonzini } 4289c50d8ae3SPaolo Bonzini 4290c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4291c50d8ae3SPaolo Bonzini return true; 4292c50d8ae3SPaolo Bonzini } 4293c50d8ae3SPaolo Bonzini 4294c50d8ae3SPaolo Bonzini return false; 4295c50d8ae3SPaolo Bonzini } 4296c50d8ae3SPaolo Bonzini 4297c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4298c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4299c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4300c50d8ae3SPaolo Bonzini #undef PTTYPE 4301c50d8ae3SPaolo Bonzini 4302c50d8ae3SPaolo Bonzini #define PTTYPE 64 4303c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4304c50d8ae3SPaolo Bonzini #undef PTTYPE 4305c50d8ae3SPaolo Bonzini 4306c50d8ae3SPaolo Bonzini #define PTTYPE 32 4307c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4308c50d8ae3SPaolo Bonzini #undef PTTYPE 4309c50d8ae3SPaolo Bonzini 4310c50d8ae3SPaolo Bonzini static void 4311b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 43125b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4313c50d8ae3SPaolo Bonzini bool pse, bool amd) 4314c50d8ae3SPaolo Bonzini { 4315c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4316c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 43175b7f575cSSean Christopherson u64 high_bits_rsvd; 4318c50d8ae3SPaolo Bonzini 4319c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4320c50d8ae3SPaolo Bonzini 4321c50d8ae3SPaolo Bonzini if (!gbpages) 4322c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4323c50d8ae3SPaolo Bonzini 43245b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 43255b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 43265b7f575cSSean Christopherson else 43275b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 43285b7f575cSSean Christopherson 43295b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 43305b7f575cSSean Christopherson if (!nx) 43315b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 43325b7f575cSSean Christopherson 4333c50d8ae3SPaolo Bonzini /* 4334c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4335c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4336c50d8ae3SPaolo Bonzini */ 4337c50d8ae3SPaolo Bonzini if (amd) 4338c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4339c50d8ae3SPaolo Bonzini 4340c50d8ae3SPaolo Bonzini switch (level) { 4341c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4342c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4343c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4344c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4345c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4346c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4347c50d8ae3SPaolo Bonzini 4348c50d8ae3SPaolo Bonzini if (!pse) { 4349c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4350c50d8ae3SPaolo Bonzini break; 4351c50d8ae3SPaolo Bonzini } 4352c50d8ae3SPaolo Bonzini 4353c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4354c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4355c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4356c50d8ae3SPaolo Bonzini else 4357c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4358c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4359c50d8ae3SPaolo Bonzini break; 4360c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 43615b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 43625b7f575cSSean Christopherson high_bits_rsvd | 43635b7f575cSSean Christopherson rsvd_bits(5, 8) | 43645b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 43655b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 43665b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 43675b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4368c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4369c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4370c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4371c50d8ae3SPaolo Bonzini break; 4372c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 43735b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 43745b7f575cSSean Christopherson nonleaf_bit8_rsvd | 43755b7f575cSSean Christopherson rsvd_bits(7, 7); 4376c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4377c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4378df561f66SGustavo A. R. Silva fallthrough; 4379c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 43805b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 43815b7f575cSSean Christopherson nonleaf_bit8_rsvd | 43825b7f575cSSean Christopherson rsvd_bits(7, 7); 43835b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 43845b7f575cSSean Christopherson gbpages_bit_rsvd; 43855b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 43865b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4387c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4388c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 43895b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 43905b7f575cSSean Christopherson gbpages_bit_rsvd | 4391c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 43925b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4393c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4394c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4395c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4396c50d8ae3SPaolo Bonzini break; 4397c50d8ae3SPaolo Bonzini } 4398c50d8ae3SPaolo Bonzini } 4399c50d8ae3SPaolo Bonzini 440027de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 440127de9250SSean Christopherson { 440227de9250SSean Christopherson /* 440327de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 440427de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 440527de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 440627de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 440727de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 440827de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 440927de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 441027de9250SSean Christopherson */ 441127de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 441227de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 441327de9250SSean Christopherson } 441427de9250SSean Christopherson 4415c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4416c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4417c50d8ae3SPaolo Bonzini { 4418b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 44195b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 44204d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 442127de9250SSean Christopherson guest_can_use_gbpages(vcpu), 44224e9c0d80SSean Christopherson is_cr4_pse(context), 442323493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4424c50d8ae3SPaolo Bonzini } 4425c50d8ae3SPaolo Bonzini 4426c50d8ae3SPaolo Bonzini static void 4427c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 442884ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4429c50d8ae3SPaolo Bonzini { 44305b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 443184ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4432c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4433c50d8ae3SPaolo Bonzini 443484ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 443584ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 443684ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 443784ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 443884ea5c09SLai Jiangshan 44395b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 44405b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 444184ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 444284ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 44435b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4444c50d8ae3SPaolo Bonzini 4445c50d8ae3SPaolo Bonzini /* large page */ 4446c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4447c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 444884ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 444984ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4450c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4451c50d8ae3SPaolo Bonzini 4452c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4453c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4454c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4455c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4456c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4457c50d8ae3SPaolo Bonzini if (!execonly) { 4458c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4459c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4460c50d8ae3SPaolo Bonzini } 4461c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4462c50d8ae3SPaolo Bonzini } 4463c50d8ae3SPaolo Bonzini 4464c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 446584ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4466c50d8ae3SPaolo Bonzini { 4467c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 446884ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 446984ea5c09SLai Jiangshan huge_page_level); 4470c50d8ae3SPaolo Bonzini } 4471c50d8ae3SPaolo Bonzini 44726f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 44736f8e65a6SSean Christopherson { 44746f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 44756f8e65a6SSean Christopherson } 44766f8e65a6SSean Christopherson 4477c50d8ae3SPaolo Bonzini /* 4478c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4479c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4480c50d8ae3SPaolo Bonzini * follow the features in guest. 4481c50d8ae3SPaolo Bonzini */ 448216be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 448316be1d12SSean Christopherson struct kvm_mmu *context) 4484c50d8ae3SPaolo Bonzini { 44858c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 44868c985b2dSSean Christopherson bool is_amd = true; 44878c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 44888c985b2dSSean Christopherson bool is_pse = false; 4489c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4490c50d8ae3SPaolo Bonzini int i; 4491c50d8ae3SPaolo Bonzini 4492a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 44938c985b2dSSean Christopherson 4494c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4495b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4496a972e29cSPaolo Bonzini context->root_role.level, 44977a458f0eSPaolo Bonzini context->root_role.efer_nx, 449827de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4499c50d8ae3SPaolo Bonzini 4500c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4501c50d8ae3SPaolo Bonzini return; 4502c50d8ae3SPaolo Bonzini 4503a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4504c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4505c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4506c50d8ae3SPaolo Bonzini } 4507c50d8ae3SPaolo Bonzini 4508c50d8ae3SPaolo Bonzini } 4509c50d8ae3SPaolo Bonzini 4510c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4511c50d8ae3SPaolo Bonzini { 4512c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4513c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4514c50d8ae3SPaolo Bonzini } 4515c50d8ae3SPaolo Bonzini 4516c50d8ae3SPaolo Bonzini /* 4517c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4518c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4519c50d8ae3SPaolo Bonzini */ 4520c50d8ae3SPaolo Bonzini static void 4521e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4522c50d8ae3SPaolo Bonzini { 4523c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4524c50d8ae3SPaolo Bonzini int i; 4525c50d8ae3SPaolo Bonzini 4526c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4527c50d8ae3SPaolo Bonzini 4528c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4529b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4530a972e29cSPaolo Bonzini context->root_role.level, false, 4531c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 45328c985b2dSSean Christopherson false, true); 4533c50d8ae3SPaolo Bonzini else 4534c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 453584ea5c09SLai Jiangshan reserved_hpa_bits(), false, 453684ea5c09SLai Jiangshan max_huge_page_level); 4537c50d8ae3SPaolo Bonzini 4538c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4539c50d8ae3SPaolo Bonzini return; 4540c50d8ae3SPaolo Bonzini 4541a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4542c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4543c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4544c50d8ae3SPaolo Bonzini } 4545c50d8ae3SPaolo Bonzini } 4546c50d8ae3SPaolo Bonzini 4547c50d8ae3SPaolo Bonzini /* 4548c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4549c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4550c50d8ae3SPaolo Bonzini */ 4551c50d8ae3SPaolo Bonzini static void 4552e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4553c50d8ae3SPaolo Bonzini { 4554c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 455584ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 455684ea5c09SLai Jiangshan max_huge_page_level); 4557c50d8ae3SPaolo Bonzini } 4558c50d8ae3SPaolo Bonzini 4559c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4560c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4561c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4562c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4563c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4564c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4565c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4566c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4567c50d8ae3SPaolo Bonzini 4568c50d8ae3SPaolo Bonzini 4569c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4570c50d8ae3SPaolo Bonzini { 4571c50d8ae3SPaolo Bonzini unsigned byte; 4572c50d8ae3SPaolo Bonzini 4573c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4574c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4575c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4576c50d8ae3SPaolo Bonzini 4577c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4578c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4579c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 458090599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4581c50d8ae3SPaolo Bonzini 4582c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4583c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4584c50d8ae3SPaolo Bonzini 4585c50d8ae3SPaolo Bonzini /* 4586c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4587c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4588c50d8ae3SPaolo Bonzini */ 4589c50d8ae3SPaolo Bonzini 4590c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4591c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4592c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4593c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4594c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4595c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4596c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4597c50d8ae3SPaolo Bonzini u8 smepf = 0; 4598c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4599c50d8ae3SPaolo Bonzini u8 smapf = 0; 4600c50d8ae3SPaolo Bonzini 4601c50d8ae3SPaolo Bonzini if (!ept) { 4602c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4603c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4604c50d8ae3SPaolo Bonzini 4605c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 460690599c28SSean Christopherson if (!efer_nx) 4607c50d8ae3SPaolo Bonzini ff = 0; 4608c50d8ae3SPaolo Bonzini 4609c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4610c50d8ae3SPaolo Bonzini if (!cr0_wp) 4611c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4612c50d8ae3SPaolo Bonzini 4613c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4614c50d8ae3SPaolo Bonzini if (cr4_smep) 4615c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4616c50d8ae3SPaolo Bonzini 4617c50d8ae3SPaolo Bonzini /* 4618c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4619c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4620c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4621c50d8ae3SPaolo Bonzini * conditions are true: 4622c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4623c50d8ae3SPaolo Bonzini * - A user page is accessed 4624c50d8ae3SPaolo Bonzini * - The access is not a fetch 46254f4aa80eSLai Jiangshan * - The access is supervisor mode 46264f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4627c50d8ae3SPaolo Bonzini * 462894b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 462994b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4630c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4631c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4632c50d8ae3SPaolo Bonzini */ 4633c50d8ae3SPaolo Bonzini if (cr4_smap) 4634c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4635c50d8ae3SPaolo Bonzini } 4636c50d8ae3SPaolo Bonzini 4637c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4638c50d8ae3SPaolo Bonzini } 4639c50d8ae3SPaolo Bonzini } 4640c50d8ae3SPaolo Bonzini 4641c50d8ae3SPaolo Bonzini /* 4642c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4643c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4644c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4645c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4646c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4647c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4648c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4649c50d8ae3SPaolo Bonzini * 4650c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4651c50d8ae3SPaolo Bonzini * page tables and the machine state: 4652c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4653c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4654c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4655c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4656c50d8ae3SPaolo Bonzini * 4657c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4658c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4659c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4660c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4661c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4662c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4663c50d8ae3SPaolo Bonzini * only will be masked away. 4664c50d8ae3SPaolo Bonzini */ 46652e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4666c50d8ae3SPaolo Bonzini { 4667c50d8ae3SPaolo Bonzini unsigned bit; 4668c50d8ae3SPaolo Bonzini bool wp; 4669c50d8ae3SPaolo Bonzini 4670c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4671a3ca5281SChenyi Qiang 4672a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4673c50d8ae3SPaolo Bonzini return; 4674c50d8ae3SPaolo Bonzini 46752e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4676c50d8ae3SPaolo Bonzini 4677c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4678c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4679c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4680c50d8ae3SPaolo Bonzini 4681c50d8ae3SPaolo Bonzini pfec = bit << 1; 4682c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4683c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4684c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4685c50d8ae3SPaolo Bonzini 4686c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4687c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4688c50d8ae3SPaolo Bonzini 4689c50d8ae3SPaolo Bonzini /* 4690c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4691c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4692c50d8ae3SPaolo Bonzini */ 4693c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4694c50d8ae3SPaolo Bonzini /* 4695c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4696c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4697c50d8ae3SPaolo Bonzini */ 4698c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4699c50d8ae3SPaolo Bonzini 4700c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4701c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4702c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4703c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4704c50d8ae3SPaolo Bonzini 4705c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4706c50d8ae3SPaolo Bonzini } 4707c50d8ae3SPaolo Bonzini } 4708c50d8ae3SPaolo Bonzini 4709533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4710533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4711c50d8ae3SPaolo Bonzini { 4712533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4713533f9a4bSSean Christopherson return; 4714c50d8ae3SPaolo Bonzini 4715533f9a4bSSean Christopherson reset_rsvds_bits_mask(vcpu, mmu); 4716533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4717533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4718c50d8ae3SPaolo Bonzini } 4719c50d8ae3SPaolo Bonzini 4720fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4721c50d8ae3SPaolo Bonzini { 4722c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4723c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4724c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4725c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4726c50d8ae3SPaolo Bonzini } 4727c50d8ae3SPaolo Bonzini 472884a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4729c50d8ae3SPaolo Bonzini { 4730c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4731c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4732c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4733c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4734c50d8ae3SPaolo Bonzini } 4735c50d8ae3SPaolo Bonzini 47367a7ae829SPaolo Bonzini static union kvm_cpu_role 4737e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 4738e5ed0fb0SPaolo Bonzini { 47397a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4740e5ed0fb0SPaolo Bonzini 4741e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 4742e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 4743e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4744e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 4745e5ed0fb0SPaolo Bonzini 4746e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 4747e5ed0fb0SPaolo Bonzini role.base.direct = 1; 4748e5ed0fb0SPaolo Bonzini return role; 4749e5ed0fb0SPaolo Bonzini } 4750e5ed0fb0SPaolo Bonzini 4751e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 4752e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 4753e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 4754e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 4755e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 475660f3cb60SPaolo Bonzini 475760f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 475860f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 475960f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 476060f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 476160f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 476260f3cb60SPaolo Bonzini else 476360f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 4764e5ed0fb0SPaolo Bonzini 4765e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 4766e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 4767e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 4768e5ed0fb0SPaolo Bonzini 4769e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 4770e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 4771e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 4772e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 4773e5ed0fb0SPaolo Bonzini return role; 4774e5ed0fb0SPaolo Bonzini } 4775e5ed0fb0SPaolo Bonzini 4776d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 4777d468d94bSSean Christopherson { 4778746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 4779746700d2SWei Huang if (tdp_root_level) 4780746700d2SWei Huang return tdp_root_level; 4781746700d2SWei Huang 4782d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 478383013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 4784d468d94bSSean Christopherson return 4; 4785d468d94bSSean Christopherson 478683013059SSean Christopherson return max_tdp_level; 4787d468d94bSSean Christopherson } 4788d468d94bSSean Christopherson 47897a458f0eSPaolo Bonzini static union kvm_mmu_page_role 47908626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 47917a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 4792c50d8ae3SPaolo Bonzini { 47937a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 4794c50d8ae3SPaolo Bonzini 47957a458f0eSPaolo Bonzini role.access = ACC_ALL; 47967a458f0eSPaolo Bonzini role.cr0_wp = true; 47977a458f0eSPaolo Bonzini role.efer_nx = true; 47987a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 47997a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 48007a458f0eSPaolo Bonzini role.ad_disabled = (shadow_accessed_mask == 0); 48017a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 48027a458f0eSPaolo Bonzini role.direct = true; 48037a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 4804c50d8ae3SPaolo Bonzini 4805c50d8ae3SPaolo Bonzini return role; 4806c50d8ae3SPaolo Bonzini } 4807c50d8ae3SPaolo Bonzini 480839e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 4809a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 4810c50d8ae3SPaolo Bonzini { 48118c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 48127a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 4813c50d8ae3SPaolo Bonzini 4814e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 48157a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 4816c50d8ae3SPaolo Bonzini return; 4817c50d8ae3SPaolo Bonzini 4818e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 48197a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 48207a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 4821c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 48225efac074SPaolo Bonzini context->invlpg = NULL; 4823d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4824c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4825c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 4826c50d8ae3SPaolo Bonzini 482736f26787SSean Christopherson if (!is_cr0_pg(context)) 4828c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 482936f26787SSean Christopherson else if (is_cr4_pae(context)) 4830c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4831f4bd6f73SSean Christopherson else 4832c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4833c50d8ae3SPaolo Bonzini 4834533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4835e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 4836c50d8ae3SPaolo Bonzini } 4837c50d8ae3SPaolo Bonzini 48388c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 48397a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 48407a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 4841c50d8ae3SPaolo Bonzini { 4842e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 48437a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 484418db1b17SSean Christopherson return; 4845c50d8ae3SPaolo Bonzini 4846e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 48477a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 484818db1b17SSean Christopherson 484936f26787SSean Christopherson if (!is_cr0_pg(context)) 485084a16226SSean Christopherson nonpaging_init_context(context); 485136f26787SSean Christopherson else if (is_cr4_pae(context)) 4852fe660f72SSean Christopherson paging64_init_context(context); 4853c50d8ae3SPaolo Bonzini else 485484a16226SSean Christopherson paging32_init_context(context); 4855c50d8ae3SPaolo Bonzini 4856533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4857c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 4858c50d8ae3SPaolo Bonzini } 48590f04a2acSVitaly Kuznetsov 4860594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 4861a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 48620f04a2acSVitaly Kuznetsov { 48638c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 486456b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 486556b321f9SPaolo Bonzini 486656b321f9SPaolo Bonzini root_role = cpu_role.base; 486756b321f9SPaolo Bonzini 486856b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 486956b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 487056b321f9SPaolo Bonzini 487156b321f9SPaolo Bonzini /* 487256b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 487356b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 487456b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 487556b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 487656b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 487756b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 487856b321f9SPaolo Bonzini * MMU contexts. 487956b321f9SPaolo Bonzini */ 488056b321f9SPaolo Bonzini root_role.efer_nx = true; 48810f04a2acSVitaly Kuznetsov 48827a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 48830f04a2acSVitaly Kuznetsov } 48840f04a2acSVitaly Kuznetsov 4885dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 4886dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 48870f04a2acSVitaly Kuznetsov { 48888c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4889594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 4890594e91a1SSean Christopherson .cr0 = cr0, 489128f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 4892594e91a1SSean Christopherson .efer = efer, 4893594e91a1SSean Christopherson }; 48947a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 489556b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 489656b321f9SPaolo Bonzini 489756b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 489856b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 489956b321f9SPaolo Bonzini 490056b321f9SPaolo Bonzini root_role = cpu_role.base; 490156b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 49020f04a2acSVitaly Kuznetsov 49037a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 4904d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 49050f04a2acSVitaly Kuznetsov } 49060f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 4907c50d8ae3SPaolo Bonzini 49087a7ae829SPaolo Bonzini static union kvm_cpu_role 4909c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 4910bb1fcc70SSean Christopherson bool execonly, u8 level) 4911c50d8ae3SPaolo Bonzini { 49127a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4913c50d8ae3SPaolo Bonzini 4914daed87b8SPaolo Bonzini /* 4915daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 4916daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 4917daed87b8SPaolo Bonzini */ 4918daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 4919bb1fcc70SSean Christopherson role.base.level = level; 4920bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 4921c50d8ae3SPaolo Bonzini role.base.direct = false; 4922c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 4923c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 4924c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 4925c50d8ae3SPaolo Bonzini 4926cd6767c3SSean Christopherson role.ext.word = 0; 4927c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 4928cd6767c3SSean Christopherson role.ext.valid = 1; 4929c50d8ae3SPaolo Bonzini 4930c50d8ae3SPaolo Bonzini return role; 4931c50d8ae3SPaolo Bonzini } 4932c50d8ae3SPaolo Bonzini 4933c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 4934cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 4935cc022ae1SLai Jiangshan gpa_t new_eptp) 4936c50d8ae3SPaolo Bonzini { 49378c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4938bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 49397a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 4940c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 4941bb1fcc70SSean Christopherson execonly, level); 4942c50d8ae3SPaolo Bonzini 4943e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 4944e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 4945e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 49467a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 494718db1b17SSean Christopherson 4948c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 4949c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 4950c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 4951c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 4952*347a0d0dSPaolo Bonzini 4953c596f147SSean Christopherson update_permission_bitmask(context, true); 495428f091bcSPaolo Bonzini context->pkru_mask = 0; 4955cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 4956e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 4957c50d8ae3SPaolo Bonzini } 49583cffc89dSPaolo Bonzini 4959d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 49603cffc89dSPaolo Bonzini } 4961c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 4962c50d8ae3SPaolo Bonzini 496339e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 4964a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 4965c50d8ae3SPaolo Bonzini { 49668c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 4967c50d8ae3SPaolo Bonzini 4968a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 4969929d1cfaSPaolo Bonzini 4970d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4971c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4972c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 4973c50d8ae3SPaolo Bonzini } 4974c50d8ae3SPaolo Bonzini 497539e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 4976a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 4977c50d8ae3SPaolo Bonzini { 4978c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 4979c50d8ae3SPaolo Bonzini 4980e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 4981c50d8ae3SPaolo Bonzini return; 4982c50d8ae3SPaolo Bonzini 4983e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 4984d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 4985c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 4986c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 4987c50d8ae3SPaolo Bonzini 4988c50d8ae3SPaolo Bonzini /* 49895efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 49905efac074SPaolo Bonzini * SPTEs. 49915efac074SPaolo Bonzini */ 49925efac074SPaolo Bonzini g_context->invlpg = NULL; 49935efac074SPaolo Bonzini 49945efac074SPaolo Bonzini /* 4995c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 4996c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 4997c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 4998c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 4999c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5000c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5001c50d8ae3SPaolo Bonzini */ 5002fa4b5588SSean Christopherson if (!is_paging(vcpu)) 50031f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5004fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 50051f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5006fa4b5588SSean Christopherson else if (is_pae(vcpu)) 50071f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5008fa4b5588SSean Christopherson else 50091f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5010fa4b5588SSean Christopherson 5011533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5012c50d8ae3SPaolo Bonzini } 5013c50d8ae3SPaolo Bonzini 5014c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5015c50d8ae3SPaolo Bonzini { 501639e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5017a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 501839e7e2bfSPaolo Bonzini 5019c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5020a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5021c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5022a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5023c50d8ae3SPaolo Bonzini else 5024a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5025c50d8ae3SPaolo Bonzini } 5026c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5027c50d8ae3SPaolo Bonzini 502849c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 502949c6f875SSean Christopherson { 503049c6f875SSean Christopherson /* 503149c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 503249c6f875SSean Christopherson * information is factored into reserved bit calculations. 5033feb627e8SVitaly Kuznetsov * 5034feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5035feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5036feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5037feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5038feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5039feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5040feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 504149c6f875SSean Christopherson */ 50427a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 50437a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 50447a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5045e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5046e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5047e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 504849c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 504963f5a190SSean Christopherson 505063f5a190SSean Christopherson /* 5051feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5052feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 505363f5a190SSean Christopherson */ 5054feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 505549c6f875SSean Christopherson } 505649c6f875SSean Christopherson 5057c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5058c50d8ae3SPaolo Bonzini { 5059c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5060c9060662SSean Christopherson kvm_init_mmu(vcpu); 5061c50d8ae3SPaolo Bonzini } 5062c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5063c50d8ae3SPaolo Bonzini 5064c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5065c50d8ae3SPaolo Bonzini { 5066c50d8ae3SPaolo Bonzini int r; 5067c50d8ae3SPaolo Bonzini 5068*347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5069c50d8ae3SPaolo Bonzini if (r) 5070c50d8ae3SPaolo Bonzini goto out; 5071748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5072c50d8ae3SPaolo Bonzini if (r) 5073c50d8ae3SPaolo Bonzini goto out; 5074*347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 50756e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 50766e6ec584SSean Christopherson else 50776e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5078c50d8ae3SPaolo Bonzini if (r) 5079c50d8ae3SPaolo Bonzini goto out; 5080a91f387bSSean Christopherson 5081a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5082a91f387bSSean Christopherson 5083727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5084db01416bSSean Christopherson 5085db01416bSSean Christopherson /* 5086db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5087db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5088db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5089db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5090db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5091db01416bSSean Christopherson */ 5092e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5093c50d8ae3SPaolo Bonzini out: 5094c50d8ae3SPaolo Bonzini return r; 5095c50d8ae3SPaolo Bonzini } 5096c50d8ae3SPaolo Bonzini 5097c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5098c50d8ae3SPaolo Bonzini { 50990c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 51000c1c92f1SPaolo Bonzini 51010c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5102b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 51030c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5104b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 51056d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5106c50d8ae3SPaolo Bonzini } 5107c50d8ae3SPaolo Bonzini 5108527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5109527d5cd7SSean Christopherson { 5110527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5111527d5cd7SSean Christopherson 5112527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5113527d5cd7SSean Christopherson return false; 5114527d5cd7SSean Christopherson 5115527d5cd7SSean Christopherson /* 5116527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5117527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5118527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5119527d5cd7SSean Christopherson * such false positives are relatively rare: 5120527d5cd7SSean Christopherson * 5121527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5122527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5123527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5124527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5125527d5cd7SSean Christopherson */ 5126527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5127527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5128527d5cd7SSean Christopherson } 5129527d5cd7SSean Christopherson 5130527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5131527d5cd7SSean Christopherson { 5132527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5133527d5cd7SSean Christopherson int i; 5134527d5cd7SSean Christopherson 5135527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5136527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5137527d5cd7SSean Christopherson 5138527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5139527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5140527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5141527d5cd7SSean Christopherson } 5142527d5cd7SSean Christopherson 5143527d5cd7SSean Christopherson if (roots_to_free) 5144527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5145527d5cd7SSean Christopherson } 5146527d5cd7SSean Christopherson 5147527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5148527d5cd7SSean Christopherson { 5149527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5150527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5151527d5cd7SSean Christopherson } 5152527d5cd7SSean Christopherson 5153c50d8ae3SPaolo Bonzini static bool need_remote_flush(u64 old, u64 new) 5154c50d8ae3SPaolo Bonzini { 5155c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old)) 5156c50d8ae3SPaolo Bonzini return false; 5157c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(new)) 5158c50d8ae3SPaolo Bonzini return true; 5159c50d8ae3SPaolo Bonzini if ((old ^ new) & PT64_BASE_ADDR_MASK) 5160c50d8ae3SPaolo Bonzini return true; 5161c50d8ae3SPaolo Bonzini old ^= shadow_nx_mask; 5162c50d8ae3SPaolo Bonzini new ^= shadow_nx_mask; 5163c50d8ae3SPaolo Bonzini return (old & ~new & PT64_PERM_MASK) != 0; 5164c50d8ae3SPaolo Bonzini } 5165c50d8ae3SPaolo Bonzini 5166c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5167c50d8ae3SPaolo Bonzini int *bytes) 5168c50d8ae3SPaolo Bonzini { 5169c50d8ae3SPaolo Bonzini u64 gentry = 0; 5170c50d8ae3SPaolo Bonzini int r; 5171c50d8ae3SPaolo Bonzini 5172c50d8ae3SPaolo Bonzini /* 5173c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5174c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5175c50d8ae3SPaolo Bonzini * when they have the same mode. 5176c50d8ae3SPaolo Bonzini */ 5177c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5178c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5179c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5180c50d8ae3SPaolo Bonzini *bytes = 8; 5181c50d8ae3SPaolo Bonzini } 5182c50d8ae3SPaolo Bonzini 5183c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5184c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5185c50d8ae3SPaolo Bonzini if (r) 5186c50d8ae3SPaolo Bonzini gentry = 0; 5187c50d8ae3SPaolo Bonzini } 5188c50d8ae3SPaolo Bonzini 5189c50d8ae3SPaolo Bonzini return gentry; 5190c50d8ae3SPaolo Bonzini } 5191c50d8ae3SPaolo Bonzini 5192c50d8ae3SPaolo Bonzini /* 5193c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5194c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5195c50d8ae3SPaolo Bonzini */ 5196c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5197c50d8ae3SPaolo Bonzini { 5198c50d8ae3SPaolo Bonzini /* 5199c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5200c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5201c50d8ae3SPaolo Bonzini */ 52023bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5203c50d8ae3SPaolo Bonzini return false; 5204c50d8ae3SPaolo Bonzini 5205c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5206c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5207c50d8ae3SPaolo Bonzini } 5208c50d8ae3SPaolo Bonzini 5209c50d8ae3SPaolo Bonzini /* 5210c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5211c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5212c50d8ae3SPaolo Bonzini */ 5213c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5214c50d8ae3SPaolo Bonzini int bytes) 5215c50d8ae3SPaolo Bonzini { 5216c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5217c50d8ae3SPaolo Bonzini 5218c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5219c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5220c50d8ae3SPaolo Bonzini 5221c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5222bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5223c50d8ae3SPaolo Bonzini 5224c50d8ae3SPaolo Bonzini /* 5225c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5226c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5227c50d8ae3SPaolo Bonzini */ 5228c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5229c50d8ae3SPaolo Bonzini return false; 5230c50d8ae3SPaolo Bonzini 5231c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5232c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5233c50d8ae3SPaolo Bonzini 5234c50d8ae3SPaolo Bonzini return misaligned; 5235c50d8ae3SPaolo Bonzini } 5236c50d8ae3SPaolo Bonzini 5237c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5238c50d8ae3SPaolo Bonzini { 5239c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5240c50d8ae3SPaolo Bonzini u64 *spte; 5241c50d8ae3SPaolo Bonzini int level; 5242c50d8ae3SPaolo Bonzini 5243c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5244c50d8ae3SPaolo Bonzini level = sp->role.level; 5245c50d8ae3SPaolo Bonzini *nspte = 1; 5246bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5247c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5248c50d8ae3SPaolo Bonzini /* 5249c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5250c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5251c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5252c50d8ae3SPaolo Bonzini */ 5253c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5254c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5255c50d8ae3SPaolo Bonzini page_offset <<= 1; 5256c50d8ae3SPaolo Bonzini *nspte = 2; 5257c50d8ae3SPaolo Bonzini } 5258c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5259c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5260c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5261c50d8ae3SPaolo Bonzini return NULL; 5262c50d8ae3SPaolo Bonzini } 5263c50d8ae3SPaolo Bonzini 5264c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5265c50d8ae3SPaolo Bonzini return spte; 5266c50d8ae3SPaolo Bonzini } 5267c50d8ae3SPaolo Bonzini 5268c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5269c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5270c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5271c50d8ae3SPaolo Bonzini { 5272c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5273c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5274c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5275c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5276c50d8ae3SPaolo Bonzini int npte; 527706152b2dSLai Jiangshan bool flush = false; 5278c50d8ae3SPaolo Bonzini 5279c50d8ae3SPaolo Bonzini /* 5280c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5281c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5282c50d8ae3SPaolo Bonzini */ 5283c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5284c50d8ae3SPaolo Bonzini return; 5285c50d8ae3SPaolo Bonzini 5286c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5287c50d8ae3SPaolo Bonzini 5288c50d8ae3SPaolo Bonzini /* 5289c50d8ae3SPaolo Bonzini * No need to care whether allocation memory is successful 5290d9f6e12fSIngo Molnar * or not since pte prefetch is skipped if it does not have 5291c50d8ae3SPaolo Bonzini * enough objects in the cache. 5292c50d8ae3SPaolo Bonzini */ 5293378f5cd6SSean Christopherson mmu_topup_memory_caches(vcpu, true); 5294c50d8ae3SPaolo Bonzini 5295531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5296c50d8ae3SPaolo Bonzini 5297c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5298c50d8ae3SPaolo Bonzini 5299c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5300c50d8ae3SPaolo Bonzini 5301c50d8ae3SPaolo Bonzini for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) { 5302c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5303c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5304c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5305c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5306c50d8ae3SPaolo Bonzini continue; 5307c50d8ae3SPaolo Bonzini } 5308c50d8ae3SPaolo Bonzini 5309c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5310c50d8ae3SPaolo Bonzini if (!spte) 5311c50d8ae3SPaolo Bonzini continue; 5312c50d8ae3SPaolo Bonzini 5313c50d8ae3SPaolo Bonzini while (npte--) { 5314c50d8ae3SPaolo Bonzini entry = *spte; 53152de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5316c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5317c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 5318c50d8ae3SPaolo Bonzini if (need_remote_flush(entry, *spte)) 531906152b2dSLai Jiangshan flush = true; 5320c50d8ae3SPaolo Bonzini ++spte; 5321c50d8ae3SPaolo Bonzini } 5322c50d8ae3SPaolo Bonzini } 532306152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5324531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5325c50d8ae3SPaolo Bonzini } 5326c50d8ae3SPaolo Bonzini 5327736c291cSSean Christopherson int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5328c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5329c50d8ae3SPaolo Bonzini { 533092daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5331*347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5332c50d8ae3SPaolo Bonzini 5333b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5334ddce6208SSean Christopherson return RET_PF_RETRY; 5335ddce6208SSean Christopherson 5336c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5337c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5338736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5339c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5340c50d8ae3SPaolo Bonzini goto emulate; 5341c50d8ae3SPaolo Bonzini } 5342c50d8ae3SPaolo Bonzini 5343c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 53447a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 53457a02674dSSean Christopherson lower_32_bits(error_code), false); 534619025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 53477b367bc9SSean Christopherson return -EIO; 5348c50d8ae3SPaolo Bonzini } 5349c50d8ae3SPaolo Bonzini 5350c50d8ae3SPaolo Bonzini if (r < 0) 5351c50d8ae3SPaolo Bonzini return r; 535283a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 535383a2ba4cSSean Christopherson return 1; 5354c50d8ae3SPaolo Bonzini 5355c50d8ae3SPaolo Bonzini /* 5356c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5357c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5358c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5359c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5360c50d8ae3SPaolo Bonzini * and resume the guest. 5361c50d8ae3SPaolo Bonzini */ 5362*347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5363c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5364736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5365c50d8ae3SPaolo Bonzini return 1; 5366c50d8ae3SPaolo Bonzini } 5367c50d8ae3SPaolo Bonzini 5368c50d8ae3SPaolo Bonzini /* 5369c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5370c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5371c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5372c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5373c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5374c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5375c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5376c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5377c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5378c50d8ae3SPaolo Bonzini */ 5379736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 538092daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5381c50d8ae3SPaolo Bonzini emulate: 5382736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5383c50d8ae3SPaolo Bonzini insn_len); 5384c50d8ae3SPaolo Bonzini } 5385c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5386c50d8ae3SPaolo Bonzini 53875efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 53885efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5389c50d8ae3SPaolo Bonzini { 5390c50d8ae3SPaolo Bonzini int i; 5391c50d8ae3SPaolo Bonzini 53925efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 53935efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 53945efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5395c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5396c50d8ae3SPaolo Bonzini return; 5397c50d8ae3SPaolo Bonzini 5398e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 53995efac074SPaolo Bonzini } 54005efac074SPaolo Bonzini 54015efac074SPaolo Bonzini if (!mmu->invlpg) 54025efac074SPaolo Bonzini return; 54035efac074SPaolo Bonzini 54045efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5405b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5406c50d8ae3SPaolo Bonzini 5407c50d8ae3SPaolo Bonzini /* 5408c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5409c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5410c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5411c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5412c50d8ae3SPaolo Bonzini * just always sync it. 5413c50d8ae3SPaolo Bonzini * 5414c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5415c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5416c50d8ae3SPaolo Bonzini * for them. 5417c50d8ae3SPaolo Bonzini */ 5418c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5419c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5420c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 54215efac074SPaolo Bonzini } else { 54225efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 54235efac074SPaolo Bonzini } 54245efac074SPaolo Bonzini } 5425c50d8ae3SPaolo Bonzini 54265efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 54275efac074SPaolo Bonzini { 542805b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5429c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5430c50d8ae3SPaolo Bonzini } 5431c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5432c50d8ae3SPaolo Bonzini 54335efac074SPaolo Bonzini 5434c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5435c50d8ae3SPaolo Bonzini { 5436c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5437c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5438c50d8ae3SPaolo Bonzini uint i; 5439c50d8ae3SPaolo Bonzini 5440c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 5441b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5442c50d8ae3SPaolo Bonzini tlb_flush = true; 5443c50d8ae3SPaolo Bonzini } 5444c50d8ae3SPaolo Bonzini 5445c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5446c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5447be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 5448c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5449c50d8ae3SPaolo Bonzini tlb_flush = true; 5450c50d8ae3SPaolo Bonzini } 5451c50d8ae3SPaolo Bonzini } 5452c50d8ae3SPaolo Bonzini 5453c50d8ae3SPaolo Bonzini if (tlb_flush) 5454e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5455c50d8ae3SPaolo Bonzini 5456c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5457c50d8ae3SPaolo Bonzini 5458c50d8ae3SPaolo Bonzini /* 5459c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5460c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5461c50d8ae3SPaolo Bonzini * for them. 5462c50d8ae3SPaolo Bonzini */ 5463c50d8ae3SPaolo Bonzini } 5464c50d8ae3SPaolo Bonzini 5465746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5466746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5467c50d8ae3SPaolo Bonzini { 5468bde77235SSean Christopherson tdp_enabled = enable_tdp; 5469746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 547083013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5471703c335dSSean Christopherson 5472703c335dSSean Christopherson /* 54731d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5474703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5475703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5476703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5477703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5478703c335dSSean Christopherson */ 5479703c335dSSean Christopherson if (tdp_enabled) 54801d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5481703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 54821d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5483703c335dSSean Christopherson else 54841d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5485c50d8ae3SPaolo Bonzini } 5486bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5487c50d8ae3SPaolo Bonzini 5488c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5489269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5490269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5491269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5492c50d8ae3SPaolo Bonzini 5493c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5494c50d8ae3SPaolo Bonzini static __always_inline bool 5495269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5496c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 54971a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 54981a61b7dbSSean Christopherson bool flush) 5499c50d8ae3SPaolo Bonzini { 5500c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5501c50d8ae3SPaolo Bonzini 5502c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5503c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5504c50d8ae3SPaolo Bonzini if (iterator.rmap) 55050a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5506c50d8ae3SPaolo Bonzini 5507531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5508302695a5SSean Christopherson if (flush && flush_on_yield) { 5509c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5510c50d8ae3SPaolo Bonzini start_gfn, 5511c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5512c50d8ae3SPaolo Bonzini flush = false; 5513c50d8ae3SPaolo Bonzini } 5514531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5515c50d8ae3SPaolo Bonzini } 5516c50d8ae3SPaolo Bonzini } 5517c50d8ae3SPaolo Bonzini 5518c50d8ae3SPaolo Bonzini return flush; 5519c50d8ae3SPaolo Bonzini } 5520c50d8ae3SPaolo Bonzini 5521c50d8ae3SPaolo Bonzini static __always_inline bool 5522269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5523c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5524302695a5SSean Christopherson bool flush_on_yield) 5525c50d8ae3SPaolo Bonzini { 5526c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5527c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5528c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 55291a61b7dbSSean Christopherson flush_on_yield, false); 5530c50d8ae3SPaolo Bonzini } 5531c50d8ae3SPaolo Bonzini 5532c50d8ae3SPaolo Bonzini static __always_inline bool 5533610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5534302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5535c50d8ae3SPaolo Bonzini { 55363bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5537302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5538c50d8ae3SPaolo Bonzini } 5539c50d8ae3SPaolo Bonzini 5540c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5541c50d8ae3SPaolo Bonzini { 55424a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 55434a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5544c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 554503ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5546cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5547c50d8ae3SPaolo Bonzini } 5548c50d8ae3SPaolo Bonzini 554904d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5550c50d8ae3SPaolo Bonzini { 5551c50d8ae3SPaolo Bonzini struct page *page; 5552c50d8ae3SPaolo Bonzini int i; 5553c50d8ae3SPaolo Bonzini 5554b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5555b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 555604d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 555704d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 555804d28e37SSean Christopherson 555927f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 556027f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 556127f4fca2SLai Jiangshan return 0; 556227f4fca2SLai Jiangshan 5563c50d8ae3SPaolo Bonzini /* 5564c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5565c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5566c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5567c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 556804d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 556904d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 557004d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 557104d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 557284432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5573c50d8ae3SPaolo Bonzini */ 5574d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5575c50d8ae3SPaolo Bonzini return 0; 5576c50d8ae3SPaolo Bonzini 5577c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5578c50d8ae3SPaolo Bonzini if (!page) 5579c50d8ae3SPaolo Bonzini return -ENOMEM; 5580c50d8ae3SPaolo Bonzini 5581c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 55824a98623dSSean Christopherson 55834a98623dSSean Christopherson /* 55844a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 55854a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 55864a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 55874a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 55884a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 55894a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 55904a98623dSSean Christopherson */ 55914a98623dSSean Christopherson if (!tdp_enabled) 55924a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 55934a98623dSSean Christopherson else 55944a98623dSSean Christopherson WARN_ON_ONCE(shadow_me_mask); 55954a98623dSSean Christopherson 5596c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5597c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5598c50d8ae3SPaolo Bonzini 5599c50d8ae3SPaolo Bonzini return 0; 5600c50d8ae3SPaolo Bonzini } 5601c50d8ae3SPaolo Bonzini 5602c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5603c50d8ae3SPaolo Bonzini { 5604c50d8ae3SPaolo Bonzini int ret; 5605c50d8ae3SPaolo Bonzini 56065962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 56075f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 56085f6078f9SSean Christopherson 56095962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 56105f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 56115962bfb7SSean Christopherson 561296880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 561396880883SSean Christopherson 5614c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5615c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5616c50d8ae3SPaolo Bonzini 561704d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5618c50d8ae3SPaolo Bonzini if (ret) 5619c50d8ae3SPaolo Bonzini return ret; 5620c50d8ae3SPaolo Bonzini 562104d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5622c50d8ae3SPaolo Bonzini if (ret) 5623c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5624c50d8ae3SPaolo Bonzini 5625c50d8ae3SPaolo Bonzini return ret; 5626c50d8ae3SPaolo Bonzini fail_allocate_root: 5627c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5628c50d8ae3SPaolo Bonzini return ret; 5629c50d8ae3SPaolo Bonzini } 5630c50d8ae3SPaolo Bonzini 5631c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5632c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5633c50d8ae3SPaolo Bonzini { 5634c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5635c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5636c50d8ae3SPaolo Bonzini 5637c50d8ae3SPaolo Bonzini restart: 5638c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5639c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5640c50d8ae3SPaolo Bonzini /* 5641c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5642c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5643c50d8ae3SPaolo Bonzini */ 5644c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5645c50d8ae3SPaolo Bonzini break; 5646c50d8ae3SPaolo Bonzini 5647c50d8ae3SPaolo Bonzini /* 5648f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5649f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5650f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5651c50d8ae3SPaolo Bonzini */ 5652f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5653c50d8ae3SPaolo Bonzini continue; 5654c50d8ae3SPaolo Bonzini 5655c50d8ae3SPaolo Bonzini /* 5656c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5657c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5658c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5659c50d8ae3SPaolo Bonzini * be in active use by the guest. 5660c50d8ae3SPaolo Bonzini */ 5661c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5662531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5663c50d8ae3SPaolo Bonzini batch = 0; 5664c50d8ae3SPaolo Bonzini goto restart; 5665c50d8ae3SPaolo Bonzini } 5666c50d8ae3SPaolo Bonzini 5667c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, 5668c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages, &nr_zapped)) { 5669c50d8ae3SPaolo Bonzini batch += nr_zapped; 5670c50d8ae3SPaolo Bonzini goto restart; 5671c50d8ae3SPaolo Bonzini } 5672c50d8ae3SPaolo Bonzini } 5673c50d8ae3SPaolo Bonzini 5674c50d8ae3SPaolo Bonzini /* 56757ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 56767ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 56777ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 56787ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 56797ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 56807ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 56817ae5840eSSean Christopherson * running with an obsolete MMU. 5682c50d8ae3SPaolo Bonzini */ 5683c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5684c50d8ae3SPaolo Bonzini } 5685c50d8ae3SPaolo Bonzini 5686c50d8ae3SPaolo Bonzini /* 5687c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5688c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5689c50d8ae3SPaolo Bonzini * 5690c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5691c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5692c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5693c50d8ae3SPaolo Bonzini * after calling the function. 5694c50d8ae3SPaolo Bonzini */ 5695c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5696c50d8ae3SPaolo Bonzini { 5697c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5698c50d8ae3SPaolo Bonzini 5699531810caSBen Gardon write_lock(&kvm->mmu_lock); 5700c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5701c50d8ae3SPaolo Bonzini 5702c50d8ae3SPaolo Bonzini /* 5703c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5704c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5705c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5706c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5707c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5708c50d8ae3SPaolo Bonzini */ 5709c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5710c50d8ae3SPaolo Bonzini 57112f6f66ccSSean Christopherson /* 57122f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 57132f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 57142f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 57152f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5716b7cccd39SBen Gardon */ 5717b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5718b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5719b7cccd39SBen Gardon 5720c50d8ae3SPaolo Bonzini /* 5721c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5722c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5723c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5724c50d8ae3SPaolo Bonzini * 5725c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5726c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5727c50d8ae3SPaolo Bonzini */ 5728527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5729c50d8ae3SPaolo Bonzini 5730c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5731faaf05b0SBen Gardon 5732531810caSBen Gardon write_unlock(&kvm->mmu_lock); 57334c6654bdSBen Gardon 5734f28e9c7fSSean Christopherson /* 5735f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5736f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5737f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5738f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5739f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5740f28e9c7fSSean Christopherson * lead to use-after-free. 5741f28e9c7fSSean Christopherson */ 574222b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 57434c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5744c50d8ae3SPaolo Bonzini } 5745c50d8ae3SPaolo Bonzini 5746c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5747c50d8ae3SPaolo Bonzini { 5748c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5749c50d8ae3SPaolo Bonzini } 5750c50d8ae3SPaolo Bonzini 5751c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5752c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5753c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5754c50d8ae3SPaolo Bonzini { 5755c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5756c50d8ae3SPaolo Bonzini } 5757c50d8ae3SPaolo Bonzini 5758a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5759c50d8ae3SPaolo Bonzini { 5760c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5761a1a39128SPaolo Bonzini int r; 5762c50d8ae3SPaolo Bonzini 5763a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5764a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5765a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5766ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5767ce25681dSSean Christopherson 5768a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5769a1a39128SPaolo Bonzini if (r < 0) 5770a1a39128SPaolo Bonzini return r; 5771fe5db27dSBen Gardon 5772c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5773c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5774c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5775a1a39128SPaolo Bonzini return 0; 5776c50d8ae3SPaolo Bonzini } 5777c50d8ae3SPaolo Bonzini 5778c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 5779c50d8ae3SPaolo Bonzini { 5780c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5781c50d8ae3SPaolo Bonzini 5782c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 5783fe5db27dSBen Gardon 5784fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 5785c50d8ae3SPaolo Bonzini } 5786c50d8ae3SPaolo Bonzini 578721fa3246SSean Christopherson static bool __kvm_zap_rmaps(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 578821fa3246SSean Christopherson { 578921fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 579021fa3246SSean Christopherson struct kvm_memslots *slots; 5791f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 579221fa3246SSean Christopherson bool flush = false; 579321fa3246SSean Christopherson gfn_t start, end; 5794f4209439SMaciej S. Szmigiero int i; 579521fa3246SSean Christopherson 579621fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 579721fa3246SSean Christopherson return flush; 579821fa3246SSean Christopherson 579921fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 580021fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 5801f4209439SMaciej S. Szmigiero 5802f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 5803f4209439SMaciej S. Szmigiero memslot = iter.slot; 580421fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 580521fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 5806f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 580721fa3246SSean Christopherson continue; 580821fa3246SSean Christopherson 580921fa3246SSean Christopherson flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, 58106ff94f27SDavid Matlack 581121fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 581221fa3246SSean Christopherson start, end - 1, true, flush); 581321fa3246SSean Christopherson } 581421fa3246SSean Christopherson } 581521fa3246SSean Christopherson 581621fa3246SSean Christopherson return flush; 581721fa3246SSean Christopherson } 581821fa3246SSean Christopherson 581988f58535SMaxim Levitsky /* 582088f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 582188f58535SMaxim Levitsky * (not including it) 582288f58535SMaxim Levitsky */ 5823c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 5824c50d8ae3SPaolo Bonzini { 582521fa3246SSean Christopherson bool flush; 5826c50d8ae3SPaolo Bonzini int i; 5827c50d8ae3SPaolo Bonzini 5828f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 5829f4209439SMaciej S. Szmigiero return; 5830f4209439SMaciej S. Szmigiero 5831531810caSBen Gardon write_lock(&kvm->mmu_lock); 58325a324c24SSean Christopherson 5833edb298c6SMaxim Levitsky kvm_inc_notifier_count(kvm, gfn_start, gfn_end); 5834edb298c6SMaxim Levitsky 583521fa3246SSean Christopherson flush = __kvm_zap_rmaps(kvm, gfn_start, gfn_end); 58366103bc07SBen Gardon 58376103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 58386103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 5839f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 5840f47e5bbbSSean Christopherson gfn_end, true, flush); 58416103bc07SBen Gardon } 58425a324c24SSean Christopherson 58435a324c24SSean Christopherson if (flush) 5844bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 5845bc3b3c10SSean Christopherson gfn_end - gfn_start); 58465a324c24SSean Christopherson 5847edb298c6SMaxim Levitsky kvm_dec_notifier_count(kvm, gfn_start, gfn_end); 5848edb298c6SMaxim Levitsky 58495a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 5850c50d8ae3SPaolo Bonzini } 5851c50d8ae3SPaolo Bonzini 5852c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 58530a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 5854269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5855c50d8ae3SPaolo Bonzini { 58561346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 5857c50d8ae3SPaolo Bonzini } 5858c50d8ae3SPaolo Bonzini 5859c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 5860269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 58613c9bd400SJay Zhou int start_level) 5862c50d8ae3SPaolo Bonzini { 5863e2209710SBen Gardon bool flush = false; 5864c50d8ae3SPaolo Bonzini 5865e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 5866531810caSBen Gardon write_lock(&kvm->mmu_lock); 58673c9bd400SJay Zhou flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, 5868e2209710SBen Gardon start_level, KVM_MAX_HUGEPAGE_LEVEL, 5869e2209710SBen Gardon false); 5870531810caSBen Gardon write_unlock(&kvm->mmu_lock); 5871e2209710SBen Gardon } 5872c50d8ae3SPaolo Bonzini 587324ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 587424ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 587524ae4cfaSBen Gardon flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 587624ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 587724ae4cfaSBen Gardon } 587824ae4cfaSBen Gardon 5879c50d8ae3SPaolo Bonzini /* 58806ff94f27SDavid Matlack * Flush TLBs if any SPTEs had to be write-protected to ensure that 58816ff94f27SDavid Matlack * guest writes are reflected in the dirty bitmap before the memslot 58826ff94f27SDavid Matlack * update completes, i.e. before enabling dirty logging is visible to 58836ff94f27SDavid Matlack * userspace. 58846ff94f27SDavid Matlack * 58856ff94f27SDavid Matlack * Perform the TLB flush outside the mmu_lock to reduce the amount of 58866ff94f27SDavid Matlack * time the lock is held. However, this does mean that another CPU can 58876ff94f27SDavid Matlack * now grab mmu_lock and encounter a write-protected SPTE while CPUs 58886ff94f27SDavid Matlack * still have a writable mapping for the associated GFN in their TLB. 58896ff94f27SDavid Matlack * 58906ff94f27SDavid Matlack * This is safe but requires KVM to be careful when making decisions 58916ff94f27SDavid Matlack * based on the write-protection status of an SPTE. Specifically, KVM 58926ff94f27SDavid Matlack * also write-protects SPTEs to monitor changes to guest page tables 58936ff94f27SDavid Matlack * during shadow paging, and must guarantee no CPUs can write to those 58946ff94f27SDavid Matlack * page before the lock is dropped. As mentioned in the previous 58956ff94f27SDavid Matlack * paragraph, a write-protected SPTE is no guarantee that CPU cannot 58966ff94f27SDavid Matlack * perform writes. So to determine if a TLB flush is truly required, KVM 58976ff94f27SDavid Matlack * will clear a separate software-only bit (MMU-writable) and skip the 58986ff94f27SDavid Matlack * flush if-and-only-if this bit was already clear. 58996ff94f27SDavid Matlack * 590002844ac1SDavid Matlack * See is_writable_pte() for more details. 5901c50d8ae3SPaolo Bonzini */ 5902c50d8ae3SPaolo Bonzini if (flush) 59037f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 5904c50d8ae3SPaolo Bonzini } 5905c50d8ae3SPaolo Bonzini 5906cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 5907cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 5908cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 5909cb00a70bSDavid Matlack u64 start, u64 end, 5910cb00a70bSDavid Matlack int target_level) 5911cb00a70bSDavid Matlack { 5912cb00a70bSDavid Matlack if (is_tdp_mmu_enabled(kvm)) 5913cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, 5914cb00a70bSDavid Matlack target_level, false); 5915cb00a70bSDavid Matlack 5916cb00a70bSDavid Matlack /* 5917cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 5918cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 5919cb00a70bSDavid Matlack */ 5920cb00a70bSDavid Matlack } 5921cb00a70bSDavid Matlack 5922a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 5923a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 5924a3fe5dbdSDavid Matlack int target_level) 5925a3fe5dbdSDavid Matlack { 5926a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 5927a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 5928a3fe5dbdSDavid Matlack 5929a3fe5dbdSDavid Matlack if (is_tdp_mmu_enabled(kvm)) { 5930a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 5931cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 5932a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 5933a3fe5dbdSDavid Matlack } 5934a3fe5dbdSDavid Matlack 5935a3fe5dbdSDavid Matlack /* 5936a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 5937a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 5938a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 5939a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 5940a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 5941a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 5942a3fe5dbdSDavid Matlack * SPTEs. 5943a3fe5dbdSDavid Matlack */ 5944a3fe5dbdSDavid Matlack } 5945a3fe5dbdSDavid Matlack 5946c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 59470a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 5948269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5949c50d8ae3SPaolo Bonzini { 5950c50d8ae3SPaolo Bonzini u64 *sptep; 5951c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 5952c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 5953c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 5954c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5955c50d8ae3SPaolo Bonzini 5956c50d8ae3SPaolo Bonzini restart: 5957c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 595857354682SSean Christopherson sp = sptep_to_sp(sptep); 5959c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(*sptep); 5960c50d8ae3SPaolo Bonzini 5961c50d8ae3SPaolo Bonzini /* 5962c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 5963c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 5964c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 5965c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 5966c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 5967c50d8ae3SPaolo Bonzini */ 5968c50d8ae3SPaolo Bonzini if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && 59699eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 59709eba50f8SSean Christopherson pfn, PG_LEVEL_NUM)) { 597171f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 5972c50d8ae3SPaolo Bonzini 5973c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 5974c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 5975c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 5976c50d8ae3SPaolo Bonzini else 5977c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 5978c50d8ae3SPaolo Bonzini 5979c50d8ae3SPaolo Bonzini goto restart; 5980c50d8ae3SPaolo Bonzini } 5981c50d8ae3SPaolo Bonzini } 5982c50d8ae3SPaolo Bonzini 5983c50d8ae3SPaolo Bonzini return need_tlb_flush; 5984c50d8ae3SPaolo Bonzini } 5985c50d8ae3SPaolo Bonzini 5986c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 5987269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5988c50d8ae3SPaolo Bonzini { 5989e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 5990531810caSBen Gardon write_lock(&kvm->mmu_lock); 5991610265eaSDavid Matlack /* 5992610265eaSDavid Matlack * Zap only 4k SPTEs since the legacy MMU only supports dirty 5993610265eaSDavid Matlack * logging at a 4k granularity and never creates collapsible 5994610265eaSDavid Matlack * 2m SPTEs during dirty logging. 5995610265eaSDavid Matlack */ 59964b85c921SSean Christopherson if (slot_handle_level_4k(kvm, slot, kvm_mmu_zap_collapsible_spte, true)) 5997302695a5SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 5998531810caSBen Gardon write_unlock(&kvm->mmu_lock); 5999e2209710SBen Gardon } 60002db6f772SBen Gardon 60012db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60022db6f772SBen Gardon read_lock(&kvm->mmu_lock); 60034b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 60042db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 60052db6f772SBen Gardon } 6006c50d8ae3SPaolo Bonzini } 6007c50d8ae3SPaolo Bonzini 6008b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 60096c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6010b3594ffbSSean Christopherson { 6011b3594ffbSSean Christopherson /* 60127f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6013302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 60147f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 60157f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 60167f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6017b3594ffbSSean Christopherson */ 6018b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6019cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6020cec37648SSean Christopherson memslot->npages); 6021b3594ffbSSean Christopherson } 6022b3594ffbSSean Christopherson 6023c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6024269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6025c50d8ae3SPaolo Bonzini { 6026e2209710SBen Gardon bool flush = false; 6027c50d8ae3SPaolo Bonzini 6028e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6029531810caSBen Gardon write_lock(&kvm->mmu_lock); 6030610265eaSDavid Matlack /* 6031610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6032610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6033610265eaSDavid Matlack */ 6034610265eaSDavid Matlack flush = slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6035531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6036e2209710SBen Gardon } 6037c50d8ae3SPaolo Bonzini 603824ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 603924ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 604024ae4cfaSBen Gardon flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 604124ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 604224ae4cfaSBen Gardon } 604324ae4cfaSBen Gardon 6044c50d8ae3SPaolo Bonzini /* 6045c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6046c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6047c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6048c50d8ae3SPaolo Bonzini * dirty_bitmap. 6049c50d8ae3SPaolo Bonzini */ 6050c50d8ae3SPaolo Bonzini if (flush) 60517f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6052c50d8ae3SPaolo Bonzini } 6053c50d8ae3SPaolo Bonzini 6054c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6055c50d8ae3SPaolo Bonzini { 6056c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6057c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6058c50d8ae3SPaolo Bonzini int ign; 6059c50d8ae3SPaolo Bonzini 6060531810caSBen Gardon write_lock(&kvm->mmu_lock); 6061c50d8ae3SPaolo Bonzini restart: 6062c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6063f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6064c50d8ae3SPaolo Bonzini continue; 6065c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6066c50d8ae3SPaolo Bonzini goto restart; 6067531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6068c50d8ae3SPaolo Bonzini goto restart; 6069c50d8ae3SPaolo Bonzini } 6070c50d8ae3SPaolo Bonzini 6071c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6072faaf05b0SBen Gardon 6073897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6074faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6075faaf05b0SBen Gardon 6076531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6077c50d8ae3SPaolo Bonzini } 6078c50d8ae3SPaolo Bonzini 6079c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6080c50d8ae3SPaolo Bonzini { 6081c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6082c50d8ae3SPaolo Bonzini 6083c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6084c50d8ae3SPaolo Bonzini 6085c50d8ae3SPaolo Bonzini /* 6086c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6087c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6088c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6089c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6090c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6091c50d8ae3SPaolo Bonzini */ 6092c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6093c50d8ae3SPaolo Bonzini 6094c50d8ae3SPaolo Bonzini /* 6095c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6096c50d8ae3SPaolo Bonzini * zap all shadow pages. 6097c50d8ae3SPaolo Bonzini */ 6098c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6099c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6100c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6101c50d8ae3SPaolo Bonzini } 6102c50d8ae3SPaolo Bonzini } 6103c50d8ae3SPaolo Bonzini 6104c50d8ae3SPaolo Bonzini static unsigned long 6105c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6106c50d8ae3SPaolo Bonzini { 6107c50d8ae3SPaolo Bonzini struct kvm *kvm; 6108c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6109c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6110c50d8ae3SPaolo Bonzini 6111c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6112c50d8ae3SPaolo Bonzini 6113c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6114c50d8ae3SPaolo Bonzini int idx; 6115c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6116c50d8ae3SPaolo Bonzini 6117c50d8ae3SPaolo Bonzini /* 6118c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6119c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6120c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6121c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6122c50d8ae3SPaolo Bonzini */ 6123c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6124c50d8ae3SPaolo Bonzini break; 6125c50d8ae3SPaolo Bonzini /* 6126c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6127c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6128c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6129c50d8ae3SPaolo Bonzini * anyway. 6130c50d8ae3SPaolo Bonzini */ 6131c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6132c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6133c50d8ae3SPaolo Bonzini continue; 6134c50d8ae3SPaolo Bonzini 6135c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6136531810caSBen Gardon write_lock(&kvm->mmu_lock); 6137c50d8ae3SPaolo Bonzini 6138c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6139c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6140c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6141c50d8ae3SPaolo Bonzini goto unlock; 6142c50d8ae3SPaolo Bonzini } 6143c50d8ae3SPaolo Bonzini 6144ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6145c50d8ae3SPaolo Bonzini 6146c50d8ae3SPaolo Bonzini unlock: 6147531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6148c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6149c50d8ae3SPaolo Bonzini 6150c50d8ae3SPaolo Bonzini /* 6151c50d8ae3SPaolo Bonzini * unfair on small ones 6152c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6153c50d8ae3SPaolo Bonzini * sadness comes quickly 6154c50d8ae3SPaolo Bonzini */ 6155c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6156c50d8ae3SPaolo Bonzini break; 6157c50d8ae3SPaolo Bonzini } 6158c50d8ae3SPaolo Bonzini 6159c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6160c50d8ae3SPaolo Bonzini return freed; 6161c50d8ae3SPaolo Bonzini } 6162c50d8ae3SPaolo Bonzini 6163c50d8ae3SPaolo Bonzini static unsigned long 6164c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6165c50d8ae3SPaolo Bonzini { 6166c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6167c50d8ae3SPaolo Bonzini } 6168c50d8ae3SPaolo Bonzini 6169c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6170c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6171c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6172c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6173c50d8ae3SPaolo Bonzini }; 6174c50d8ae3SPaolo Bonzini 6175c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6176c50d8ae3SPaolo Bonzini { 6177c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6178c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6179c50d8ae3SPaolo Bonzini } 6180c50d8ae3SPaolo Bonzini 6181c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6182c50d8ae3SPaolo Bonzini { 6183c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6184c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6185c50d8ae3SPaolo Bonzini } 6186c50d8ae3SPaolo Bonzini 6187c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6188c50d8ae3SPaolo Bonzini { 6189c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6190c50d8ae3SPaolo Bonzini } 6191c50d8ae3SPaolo Bonzini 6192c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6193c50d8ae3SPaolo Bonzini { 6194c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6195c50d8ae3SPaolo Bonzini bool new_val; 6196c50d8ae3SPaolo Bonzini 6197c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6198c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6199c50d8ae3SPaolo Bonzini new_val = 0; 6200c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6201c50d8ae3SPaolo Bonzini new_val = 1; 6202c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6203c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6204c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6205c50d8ae3SPaolo Bonzini return -EINVAL; 6206c50d8ae3SPaolo Bonzini 6207c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6208c50d8ae3SPaolo Bonzini 6209c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6210c50d8ae3SPaolo Bonzini struct kvm *kvm; 6211c50d8ae3SPaolo Bonzini 6212c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6213c50d8ae3SPaolo Bonzini 6214c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6215c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6216c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6217c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6218c50d8ae3SPaolo Bonzini 6219c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6220c50d8ae3SPaolo Bonzini } 6221c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6222c50d8ae3SPaolo Bonzini } 6223c50d8ae3SPaolo Bonzini 6224c50d8ae3SPaolo Bonzini return 0; 6225c50d8ae3SPaolo Bonzini } 6226c50d8ae3SPaolo Bonzini 62271d0e8480SSean Christopherson /* 62281d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 62291d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 62301d0e8480SSean Christopherson */ 62311d0e8480SSean Christopherson void kvm_mmu_x86_module_init(void) 6232c50d8ae3SPaolo Bonzini { 6233c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6234c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 62351d0e8480SSean Christopherson } 62361d0e8480SSean Christopherson 62371d0e8480SSean Christopherson /* 62381d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 62391d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 62401d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 62411d0e8480SSean Christopherson */ 62421d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 62431d0e8480SSean Christopherson { 62441d0e8480SSean Christopherson int ret = -ENOMEM; 6245c50d8ae3SPaolo Bonzini 6246c50d8ae3SPaolo Bonzini /* 6247c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6248c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6249c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6250c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6251c50d8ae3SPaolo Bonzini */ 6252c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6253c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 62547a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6255c50d8ae3SPaolo Bonzini 6256c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6257c50d8ae3SPaolo Bonzini 6258c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6259c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6260c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6261c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6262c50d8ae3SPaolo Bonzini goto out; 6263c50d8ae3SPaolo Bonzini 6264c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6265c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6266c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6267c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6268c50d8ae3SPaolo Bonzini goto out; 6269c50d8ae3SPaolo Bonzini 6270c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6271c50d8ae3SPaolo Bonzini goto out; 6272c50d8ae3SPaolo Bonzini 6273c50d8ae3SPaolo Bonzini ret = register_shrinker(&mmu_shrinker); 6274c50d8ae3SPaolo Bonzini if (ret) 6275c50d8ae3SPaolo Bonzini goto out; 6276c50d8ae3SPaolo Bonzini 6277c50d8ae3SPaolo Bonzini return 0; 6278c50d8ae3SPaolo Bonzini 6279c50d8ae3SPaolo Bonzini out: 6280c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6281c50d8ae3SPaolo Bonzini return ret; 6282c50d8ae3SPaolo Bonzini } 6283c50d8ae3SPaolo Bonzini 6284c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6285c50d8ae3SPaolo Bonzini { 6286c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6287c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6288c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6289c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6290c50d8ae3SPaolo Bonzini } 6291c50d8ae3SPaolo Bonzini 62921d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6293c50d8ae3SPaolo Bonzini { 6294c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6295c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6296c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6297c50d8ae3SPaolo Bonzini } 6298c50d8ae3SPaolo Bonzini 6299f47491d7SSean Christopherson /* 6300f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6301f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6302f47491d7SSean Christopherson */ 6303f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6304f47491d7SSean Christopherson { 6305f47491d7SSean Christopherson /* 6306f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6307f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6308f47491d7SSean Christopherson */ 6309f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6310f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6311f47491d7SSean Christopherson 6312f47491d7SSean Christopherson if (!enabled || !ratio) 6313f47491d7SSean Christopherson return false; 6314f47491d7SSean Christopherson 6315f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6316f47491d7SSean Christopherson if (!*period) { 6317f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6318f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6319f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6320f47491d7SSean Christopherson } 6321f47491d7SSean Christopherson return true; 6322f47491d7SSean Christopherson } 6323f47491d7SSean Christopherson 63244dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6325c50d8ae3SPaolo Bonzini { 63264dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 63274dfe4f40SJunaid Shahid uint old_period, new_period; 6328c50d8ae3SPaolo Bonzini int err; 6329c50d8ae3SPaolo Bonzini 6330f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 63314dfe4f40SJunaid Shahid 6332c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6333c50d8ae3SPaolo Bonzini if (err) 6334c50d8ae3SPaolo Bonzini return err; 6335c50d8ae3SPaolo Bonzini 6336f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 63374dfe4f40SJunaid Shahid 6338f47491d7SSean Christopherson if (is_recovery_enabled && 63394dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6340c50d8ae3SPaolo Bonzini struct kvm *kvm; 6341c50d8ae3SPaolo Bonzini 6342c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6343c50d8ae3SPaolo Bonzini 6344c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6345c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6346c50d8ae3SPaolo Bonzini 6347c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6348c50d8ae3SPaolo Bonzini } 6349c50d8ae3SPaolo Bonzini 6350c50d8ae3SPaolo Bonzini return err; 6351c50d8ae3SPaolo Bonzini } 6352c50d8ae3SPaolo Bonzini 6353c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6354c50d8ae3SPaolo Bonzini { 6355ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6356c50d8ae3SPaolo Bonzini int rcu_idx; 6357c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6358c50d8ae3SPaolo Bonzini unsigned int ratio; 6359c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6360048f4980SSean Christopherson bool flush = false; 6361c50d8ae3SPaolo Bonzini ulong to_zap; 6362c50d8ae3SPaolo Bonzini 6363c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6364531810caSBen Gardon write_lock(&kvm->mmu_lock); 6365c50d8ae3SPaolo Bonzini 6366bb95dfb9SSean Christopherson /* 6367bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6368bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6369bb95dfb9SSean Christopherson * callback. 6370bb95dfb9SSean Christopherson */ 6371bb95dfb9SSean Christopherson rcu_read_lock(); 6372bb95dfb9SSean Christopherson 6373c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6374ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 63757d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 63767d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 63777d919c7aSSean Christopherson break; 63787d919c7aSSean Christopherson 6379c50d8ae3SPaolo Bonzini /* 6380c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6381c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6382c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6383c50d8ae3SPaolo Bonzini */ 6384c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6385c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6386c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6387c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6388897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6389315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 63908d1a182eSBen Gardon } else { 6391c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6392c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 639329cf0f50SBen Gardon } 6394c50d8ae3SPaolo Bonzini 6395531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6396048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6397bb95dfb9SSean Christopherson rcu_read_unlock(); 6398bb95dfb9SSean Christopherson 6399531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6400048f4980SSean Christopherson flush = false; 6401bb95dfb9SSean Christopherson 6402bb95dfb9SSean Christopherson rcu_read_lock(); 6403c50d8ae3SPaolo Bonzini } 6404c50d8ae3SPaolo Bonzini } 6405048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6406c50d8ae3SPaolo Bonzini 6407bb95dfb9SSean Christopherson rcu_read_unlock(); 6408bb95dfb9SSean Christopherson 6409531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6410c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6411c50d8ae3SPaolo Bonzini } 6412c50d8ae3SPaolo Bonzini 6413c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6414c50d8ae3SPaolo Bonzini { 6415f47491d7SSean Christopherson bool enabled; 6416f47491d7SSean Christopherson uint period; 64174dfe4f40SJunaid Shahid 6418f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 64194dfe4f40SJunaid Shahid 6420f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6421c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6422c50d8ae3SPaolo Bonzini } 6423c50d8ae3SPaolo Bonzini 6424c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6425c50d8ae3SPaolo Bonzini { 6426c50d8ae3SPaolo Bonzini u64 start_time; 6427c50d8ae3SPaolo Bonzini long remaining_time; 6428c50d8ae3SPaolo Bonzini 6429c50d8ae3SPaolo Bonzini while (true) { 6430c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6431c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6432c50d8ae3SPaolo Bonzini 6433c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6434c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6435c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6436c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6437c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6438c50d8ae3SPaolo Bonzini } 6439c50d8ae3SPaolo Bonzini 6440c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6441c50d8ae3SPaolo Bonzini 6442c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6443c50d8ae3SPaolo Bonzini return 0; 6444c50d8ae3SPaolo Bonzini 6445c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6446c50d8ae3SPaolo Bonzini } 6447c50d8ae3SPaolo Bonzini } 6448c50d8ae3SPaolo Bonzini 6449c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6450c50d8ae3SPaolo Bonzini { 6451c50d8ae3SPaolo Bonzini int err; 6452c50d8ae3SPaolo Bonzini 6453c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6454c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6455c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6456c50d8ae3SPaolo Bonzini if (!err) 6457c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6458c50d8ae3SPaolo Bonzini 6459c50d8ae3SPaolo Bonzini return err; 6460c50d8ae3SPaolo Bonzini } 6461c50d8ae3SPaolo Bonzini 6462c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6463c50d8ae3SPaolo Bonzini { 6464c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6465c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6466c50d8ae3SPaolo Bonzini } 6467