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 { 737*84e5ffd0SLai Jiangshan if (sp->role.passthrough) 738*84e5ffd0SLai Jiangshan return sp->gfn; 739*84e5ffd0SLai Jiangshan 740c50d8ae3SPaolo Bonzini if (!sp->role.direct) 741c50d8ae3SPaolo Bonzini return sp->gfns[index]; 742c50d8ae3SPaolo Bonzini 743c50d8ae3SPaolo Bonzini return sp->gfn + (index << ((sp->role.level - 1) * PT64_LEVEL_BITS)); 744c50d8ae3SPaolo Bonzini } 745c50d8ae3SPaolo Bonzini 746c50d8ae3SPaolo Bonzini static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn) 747c50d8ae3SPaolo Bonzini { 748*84e5ffd0SLai Jiangshan if (sp->role.passthrough) { 749*84e5ffd0SLai Jiangshan WARN_ON_ONCE(gfn != sp->gfn); 750*84e5ffd0SLai Jiangshan return; 751*84e5ffd0SLai Jiangshan } 752*84e5ffd0SLai Jiangshan 753c50d8ae3SPaolo Bonzini if (!sp->role.direct) { 754c50d8ae3SPaolo Bonzini sp->gfns[index] = gfn; 755c50d8ae3SPaolo Bonzini return; 756c50d8ae3SPaolo Bonzini } 757c50d8ae3SPaolo Bonzini 758c50d8ae3SPaolo Bonzini if (WARN_ON(gfn != kvm_mmu_page_get_gfn(sp, index))) 759c50d8ae3SPaolo Bonzini pr_err_ratelimited("gfn mismatch under direct page %llx " 760c50d8ae3SPaolo Bonzini "(expected %llx, got %llx)\n", 761c50d8ae3SPaolo Bonzini sp->gfn, 762c50d8ae3SPaolo Bonzini kvm_mmu_page_get_gfn(sp, index), gfn); 763c50d8ae3SPaolo Bonzini } 764c50d8ae3SPaolo Bonzini 765c50d8ae3SPaolo Bonzini /* 766c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 767c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 768c50d8ae3SPaolo Bonzini */ 769c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7708ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 771c50d8ae3SPaolo Bonzini { 772c50d8ae3SPaolo Bonzini unsigned long idx; 773c50d8ae3SPaolo Bonzini 774c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 775c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 776c50d8ae3SPaolo Bonzini } 777c50d8ae3SPaolo Bonzini 778269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 779c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 780c50d8ae3SPaolo Bonzini { 781c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 782c50d8ae3SPaolo Bonzini int i; 783c50d8ae3SPaolo Bonzini 7843bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 785c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 786c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 787c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 788c50d8ae3SPaolo Bonzini } 789c50d8ae3SPaolo Bonzini } 790c50d8ae3SPaolo Bonzini 791269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 792c50d8ae3SPaolo Bonzini { 793c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 794c50d8ae3SPaolo Bonzini } 795c50d8ae3SPaolo Bonzini 796269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 797c50d8ae3SPaolo Bonzini { 798c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 799c50d8ae3SPaolo Bonzini } 800c50d8ae3SPaolo Bonzini 801c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 802c50d8ae3SPaolo Bonzini { 803c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 804c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 805c50d8ae3SPaolo Bonzini gfn_t gfn; 806c50d8ae3SPaolo Bonzini 807c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 808c50d8ae3SPaolo Bonzini gfn = sp->gfn; 809c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 810c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 811c50d8ae3SPaolo Bonzini 812c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8133bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 814c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 815c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 816c50d8ae3SPaolo Bonzini 817c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 818c50d8ae3SPaolo Bonzini } 819c50d8ae3SPaolo Bonzini 82029cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 821c50d8ae3SPaolo Bonzini { 822c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 823c50d8ae3SPaolo Bonzini return; 824c50d8ae3SPaolo Bonzini 825c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 826c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 827c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 828c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 829c50d8ae3SPaolo Bonzini } 830c50d8ae3SPaolo Bonzini 831c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 832c50d8ae3SPaolo Bonzini { 833c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 834c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 835c50d8ae3SPaolo Bonzini gfn_t gfn; 836c50d8ae3SPaolo Bonzini 837c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 838c50d8ae3SPaolo Bonzini gfn = sp->gfn; 839c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 840c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8413bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 842c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 843c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 844c50d8ae3SPaolo Bonzini 845c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 846c50d8ae3SPaolo Bonzini } 847c50d8ae3SPaolo Bonzini 84829cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 849c50d8ae3SPaolo Bonzini { 850c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 851c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 852c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 853c50d8ae3SPaolo Bonzini } 854c50d8ae3SPaolo Bonzini 855c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 856c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 857c50d8ae3SPaolo Bonzini bool no_dirty_log) 858c50d8ae3SPaolo Bonzini { 859c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 860c50d8ae3SPaolo Bonzini 861c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 86291b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 86391b0d268SPaolo Bonzini return NULL; 864044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 86591b0d268SPaolo Bonzini return NULL; 866c50d8ae3SPaolo Bonzini 867c50d8ae3SPaolo Bonzini return slot; 868c50d8ae3SPaolo Bonzini } 869c50d8ae3SPaolo Bonzini 870c50d8ae3SPaolo Bonzini /* 871c50d8ae3SPaolo Bonzini * About rmap_head encoding: 872c50d8ae3SPaolo Bonzini * 873c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 874c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 875c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 876c50d8ae3SPaolo Bonzini */ 877c50d8ae3SPaolo Bonzini 878c50d8ae3SPaolo Bonzini /* 879c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 880c50d8ae3SPaolo Bonzini */ 881c50d8ae3SPaolo Bonzini static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte, 882c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 883c50d8ae3SPaolo Bonzini { 884c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 88513236e25SPeter Xu int count = 0; 886c50d8ae3SPaolo Bonzini 887c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 888805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 889c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 890c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 891805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 892c50d8ae3SPaolo Bonzini desc = mmu_alloc_pte_list_desc(vcpu); 893c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 894c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 89513236e25SPeter Xu desc->spte_count = 2; 896c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 897c50d8ae3SPaolo Bonzini ++count; 898c50d8ae3SPaolo Bonzini } else { 899805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 900c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 90113236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 902c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 903c6c4f961SLi RongQing if (!desc->more) { 904c50d8ae3SPaolo Bonzini desc->more = mmu_alloc_pte_list_desc(vcpu); 905c50d8ae3SPaolo Bonzini desc = desc->more; 90613236e25SPeter Xu desc->spte_count = 0; 907c6c4f961SLi RongQing break; 908c6c4f961SLi RongQing } 909c6c4f961SLi RongQing desc = desc->more; 910c50d8ae3SPaolo Bonzini } 91113236e25SPeter Xu count += desc->spte_count; 91213236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 913c50d8ae3SPaolo Bonzini } 914c50d8ae3SPaolo Bonzini return count; 915c50d8ae3SPaolo Bonzini } 916c50d8ae3SPaolo Bonzini 917c50d8ae3SPaolo Bonzini static void 918c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 919c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 920c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 921c50d8ae3SPaolo Bonzini { 92213236e25SPeter Xu int j = desc->spte_count - 1; 923c50d8ae3SPaolo Bonzini 924c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 925c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 92613236e25SPeter Xu desc->spte_count--; 92713236e25SPeter Xu if (desc->spte_count) 928c50d8ae3SPaolo Bonzini return; 929c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 930fe3c2b4cSMiaohe Lin rmap_head->val = 0; 931c50d8ae3SPaolo Bonzini else 932c50d8ae3SPaolo Bonzini if (prev_desc) 933c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 934c50d8ae3SPaolo Bonzini else 935c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 936c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 937c50d8ae3SPaolo Bonzini } 938c50d8ae3SPaolo Bonzini 939c50d8ae3SPaolo Bonzini static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 940c50d8ae3SPaolo Bonzini { 941c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 942c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 943c50d8ae3SPaolo Bonzini int i; 944c50d8ae3SPaolo Bonzini 945c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 946c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 947c50d8ae3SPaolo Bonzini BUG(); 948c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 949805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 950c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 951c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 952c50d8ae3SPaolo Bonzini BUG(); 953c50d8ae3SPaolo Bonzini } 954c50d8ae3SPaolo Bonzini rmap_head->val = 0; 955c50d8ae3SPaolo Bonzini } else { 956805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 957c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 958c50d8ae3SPaolo Bonzini prev_desc = NULL; 959c50d8ae3SPaolo Bonzini while (desc) { 96013236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 961c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 962c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 963c50d8ae3SPaolo Bonzini desc, i, prev_desc); 964c50d8ae3SPaolo Bonzini return; 965c50d8ae3SPaolo Bonzini } 966c50d8ae3SPaolo Bonzini } 967c50d8ae3SPaolo Bonzini prev_desc = desc; 968c50d8ae3SPaolo Bonzini desc = desc->more; 969c50d8ae3SPaolo Bonzini } 970c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 971c50d8ae3SPaolo Bonzini BUG(); 972c50d8ae3SPaolo Bonzini } 973c50d8ae3SPaolo Bonzini } 974c50d8ae3SPaolo Bonzini 97571f51d2cSMingwei Zhang static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 97671f51d2cSMingwei Zhang u64 *sptep) 977c50d8ae3SPaolo Bonzini { 97871f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 979c50d8ae3SPaolo Bonzini __pte_list_remove(sptep, rmap_head); 980c50d8ae3SPaolo Bonzini } 981c50d8ae3SPaolo Bonzini 982a75b5404SPeter Xu /* Return true if rmap existed, false otherwise */ 98371f51d2cSMingwei Zhang static bool pte_list_destroy(struct kvm *kvm, struct kvm_rmap_head *rmap_head) 984a75b5404SPeter Xu { 985a75b5404SPeter Xu struct pte_list_desc *desc, *next; 986a75b5404SPeter Xu int i; 987a75b5404SPeter Xu 988a75b5404SPeter Xu if (!rmap_head->val) 989a75b5404SPeter Xu return false; 990a75b5404SPeter Xu 991a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 99271f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 993a75b5404SPeter Xu goto out; 994a75b5404SPeter Xu } 995a75b5404SPeter Xu 996a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 997a75b5404SPeter Xu 998a75b5404SPeter Xu for (; desc; desc = next) { 999a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 100071f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 1001a75b5404SPeter Xu next = desc->more; 1002a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 1003a75b5404SPeter Xu } 1004a75b5404SPeter Xu out: 1005a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 1006a75b5404SPeter Xu rmap_head->val = 0; 1007a75b5404SPeter Xu return true; 1008a75b5404SPeter Xu } 1009a75b5404SPeter Xu 10103bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10113bcd0662SPeter Xu { 10123bcd0662SPeter Xu struct pte_list_desc *desc; 10133bcd0662SPeter Xu unsigned int count = 0; 10143bcd0662SPeter Xu 10153bcd0662SPeter Xu if (!rmap_head->val) 10163bcd0662SPeter Xu return 0; 10173bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10183bcd0662SPeter Xu return 1; 10193bcd0662SPeter Xu 10203bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10213bcd0662SPeter Xu 10223bcd0662SPeter Xu while (desc) { 10233bcd0662SPeter Xu count += desc->spte_count; 10243bcd0662SPeter Xu desc = desc->more; 10253bcd0662SPeter Xu } 10263bcd0662SPeter Xu 10273bcd0662SPeter Xu return count; 10283bcd0662SPeter Xu } 10293bcd0662SPeter Xu 103093e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1031269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1032c50d8ae3SPaolo Bonzini { 1033c50d8ae3SPaolo Bonzini unsigned long idx; 1034c50d8ae3SPaolo Bonzini 1035c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10363bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1037c50d8ae3SPaolo Bonzini } 1038c50d8ae3SPaolo Bonzini 1039c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1040c50d8ae3SPaolo Bonzini { 1041356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1042c50d8ae3SPaolo Bonzini 1043356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 104494ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1045c50d8ae3SPaolo Bonzini } 1046c50d8ae3SPaolo Bonzini 1047c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1048c50d8ae3SPaolo Bonzini { 1049601f8af0SDavid Matlack struct kvm_memslots *slots; 1050601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1051c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1052c50d8ae3SPaolo Bonzini gfn_t gfn; 1053c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1054c50d8ae3SPaolo Bonzini 105557354682SSean Christopherson sp = sptep_to_sp(spte); 1056c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt); 1057601f8af0SDavid Matlack 1058601f8af0SDavid Matlack /* 105968be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 106068be1306SDavid Matlack * so we have to determine which memslots to use based on context 106168be1306SDavid Matlack * information in sp->role. 1062601f8af0SDavid Matlack */ 1063601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1064601f8af0SDavid Matlack 1065601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 106693e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1067601f8af0SDavid Matlack 1068c50d8ae3SPaolo Bonzini __pte_list_remove(spte, rmap_head); 1069c50d8ae3SPaolo Bonzini } 1070c50d8ae3SPaolo Bonzini 1071c50d8ae3SPaolo Bonzini /* 1072c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1073c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1074c50d8ae3SPaolo Bonzini */ 1075c50d8ae3SPaolo Bonzini struct rmap_iterator { 1076c50d8ae3SPaolo Bonzini /* private fields */ 1077c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1078c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1079c50d8ae3SPaolo Bonzini }; 1080c50d8ae3SPaolo Bonzini 1081c50d8ae3SPaolo Bonzini /* 1082c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1083c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10840a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1085c50d8ae3SPaolo Bonzini * 1086c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1087c50d8ae3SPaolo Bonzini */ 1088c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1089c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1090c50d8ae3SPaolo Bonzini { 1091c50d8ae3SPaolo Bonzini u64 *sptep; 1092c50d8ae3SPaolo Bonzini 1093c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1094c50d8ae3SPaolo Bonzini return NULL; 1095c50d8ae3SPaolo Bonzini 1096c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1097c50d8ae3SPaolo Bonzini iter->desc = NULL; 1098c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1099c50d8ae3SPaolo Bonzini goto out; 1100c50d8ae3SPaolo Bonzini } 1101c50d8ae3SPaolo Bonzini 1102c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1103c50d8ae3SPaolo Bonzini iter->pos = 0; 1104c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1105c50d8ae3SPaolo Bonzini out: 1106c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1107c50d8ae3SPaolo Bonzini return sptep; 1108c50d8ae3SPaolo Bonzini } 1109c50d8ae3SPaolo Bonzini 1110c50d8ae3SPaolo Bonzini /* 1111c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1112c50d8ae3SPaolo Bonzini * 1113c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1114c50d8ae3SPaolo Bonzini */ 1115c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1116c50d8ae3SPaolo Bonzini { 1117c50d8ae3SPaolo Bonzini u64 *sptep; 1118c50d8ae3SPaolo Bonzini 1119c50d8ae3SPaolo Bonzini if (iter->desc) { 1120c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1121c50d8ae3SPaolo Bonzini ++iter->pos; 1122c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1123c50d8ae3SPaolo Bonzini if (sptep) 1124c50d8ae3SPaolo Bonzini goto out; 1125c50d8ae3SPaolo Bonzini } 1126c50d8ae3SPaolo Bonzini 1127c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1128c50d8ae3SPaolo Bonzini 1129c50d8ae3SPaolo Bonzini if (iter->desc) { 1130c50d8ae3SPaolo Bonzini iter->pos = 0; 1131c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1132c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1133c50d8ae3SPaolo Bonzini goto out; 1134c50d8ae3SPaolo Bonzini } 1135c50d8ae3SPaolo Bonzini } 1136c50d8ae3SPaolo Bonzini 1137c50d8ae3SPaolo Bonzini return NULL; 1138c50d8ae3SPaolo Bonzini out: 1139c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1140c50d8ae3SPaolo Bonzini return sptep; 1141c50d8ae3SPaolo Bonzini } 1142c50d8ae3SPaolo Bonzini 1143c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1144c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1145c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1146c50d8ae3SPaolo Bonzini 1147c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1148c50d8ae3SPaolo Bonzini { 114971f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11507fa2a347SSean Christopherson 11517fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1152c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1153c50d8ae3SPaolo Bonzini } 1154c50d8ae3SPaolo Bonzini 1155c50d8ae3SPaolo Bonzini 1156c50d8ae3SPaolo Bonzini static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) 1157c50d8ae3SPaolo Bonzini { 1158c50d8ae3SPaolo Bonzini if (is_large_pte(*sptep)) { 115957354682SSean Christopherson WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); 1160c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 1161c50d8ae3SPaolo Bonzini return true; 1162c50d8ae3SPaolo Bonzini } 1163c50d8ae3SPaolo Bonzini 1164c50d8ae3SPaolo Bonzini return false; 1165c50d8ae3SPaolo Bonzini } 1166c50d8ae3SPaolo Bonzini 1167c50d8ae3SPaolo Bonzini static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) 1168c50d8ae3SPaolo Bonzini { 1169c50d8ae3SPaolo Bonzini if (__drop_large_spte(vcpu->kvm, sptep)) { 117057354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 1171c50d8ae3SPaolo Bonzini 1172c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, 1173c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1174c50d8ae3SPaolo Bonzini } 1175c50d8ae3SPaolo Bonzini } 1176c50d8ae3SPaolo Bonzini 1177c50d8ae3SPaolo Bonzini /* 1178c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1179c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1180c50d8ae3SPaolo Bonzini * 1181c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1182c50d8ae3SPaolo Bonzini * protection: 1183c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1184c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1185c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1186c50d8ae3SPaolo Bonzini * shadow page. 1187c50d8ae3SPaolo Bonzini * 1188c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1189c50d8ae3SPaolo Bonzini */ 1190c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1191c50d8ae3SPaolo Bonzini { 1192c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1193c50d8ae3SPaolo Bonzini 1194c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1195c50d8ae3SPaolo Bonzini !(pt_protect && spte_can_locklessly_be_made_writable(spte))) 1196c50d8ae3SPaolo Bonzini return false; 1197c50d8ae3SPaolo Bonzini 1198805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1199c50d8ae3SPaolo Bonzini 1200c50d8ae3SPaolo Bonzini if (pt_protect) 12015fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1202c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1203c50d8ae3SPaolo Bonzini 1204c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1205c50d8ae3SPaolo Bonzini } 1206c50d8ae3SPaolo Bonzini 12071346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1208c50d8ae3SPaolo Bonzini bool pt_protect) 1209c50d8ae3SPaolo Bonzini { 1210c50d8ae3SPaolo Bonzini u64 *sptep; 1211c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1212c50d8ae3SPaolo Bonzini bool flush = false; 1213c50d8ae3SPaolo Bonzini 1214c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1215c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1216c50d8ae3SPaolo Bonzini 1217c50d8ae3SPaolo Bonzini return flush; 1218c50d8ae3SPaolo Bonzini } 1219c50d8ae3SPaolo Bonzini 1220c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1221c50d8ae3SPaolo Bonzini { 1222c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1223c50d8ae3SPaolo Bonzini 1224805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1225c50d8ae3SPaolo Bonzini 1226c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1227c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1228c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1229c50d8ae3SPaolo Bonzini } 1230c50d8ae3SPaolo Bonzini 1231c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1232c50d8ae3SPaolo Bonzini { 1233c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1234c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1235c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1236c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1237c50d8ae3SPaolo Bonzini 1238c50d8ae3SPaolo Bonzini return was_writable; 1239c50d8ae3SPaolo Bonzini } 1240c50d8ae3SPaolo Bonzini 1241c50d8ae3SPaolo Bonzini /* 1242c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1243c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1244c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1245c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1246c50d8ae3SPaolo Bonzini */ 12470a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1248269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1249c50d8ae3SPaolo Bonzini { 1250c50d8ae3SPaolo Bonzini u64 *sptep; 1251c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1252c50d8ae3SPaolo Bonzini bool flush = false; 1253c50d8ae3SPaolo Bonzini 1254c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1255c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1256c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1257c50d8ae3SPaolo Bonzini else 1258c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1259c50d8ae3SPaolo Bonzini 1260c50d8ae3SPaolo Bonzini return flush; 1261c50d8ae3SPaolo Bonzini } 1262c50d8ae3SPaolo Bonzini 1263c50d8ae3SPaolo Bonzini /** 1264c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1265c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1266c50d8ae3SPaolo Bonzini * @slot: slot to protect 1267c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1268c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1269c50d8ae3SPaolo Bonzini * 127089212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1271c50d8ae3SPaolo Bonzini */ 1272c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1273c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1274c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1275c50d8ae3SPaolo Bonzini { 1276c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1277c50d8ae3SPaolo Bonzini 1278897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1279a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1280a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1281e2209710SBen Gardon 1282e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1283e2209710SBen Gardon return; 1284e2209710SBen Gardon 1285c50d8ae3SPaolo Bonzini while (mask) { 128693e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12873bae0459SSean Christopherson PG_LEVEL_4K, slot); 12881346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1289c50d8ae3SPaolo Bonzini 1290c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1291c50d8ae3SPaolo Bonzini mask &= mask - 1; 1292c50d8ae3SPaolo Bonzini } 1293c50d8ae3SPaolo Bonzini } 1294c50d8ae3SPaolo Bonzini 1295c50d8ae3SPaolo Bonzini /** 1296c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1297c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1298c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1299c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1300c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1301c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1302c50d8ae3SPaolo Bonzini * 1303c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1304c50d8ae3SPaolo Bonzini */ 1305a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1306c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1307c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1308c50d8ae3SPaolo Bonzini { 1309c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1310c50d8ae3SPaolo Bonzini 1311897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1312a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1313a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1314e2209710SBen Gardon 1315e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1316e2209710SBen Gardon return; 1317e2209710SBen Gardon 1318c50d8ae3SPaolo Bonzini while (mask) { 131993e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13203bae0459SSean Christopherson PG_LEVEL_4K, slot); 13210a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1322c50d8ae3SPaolo Bonzini 1323c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1324c50d8ae3SPaolo Bonzini mask &= mask - 1; 1325c50d8ae3SPaolo Bonzini } 1326c50d8ae3SPaolo Bonzini } 1327c50d8ae3SPaolo Bonzini 1328c50d8ae3SPaolo Bonzini /** 1329c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1330c50d8ae3SPaolo Bonzini * PT level pages. 1331c50d8ae3SPaolo Bonzini * 1332c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1333c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1334c50d8ae3SPaolo Bonzini * 133589212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 133689212919SKeqian Zhu * have such mappings. 1337c50d8ae3SPaolo Bonzini */ 1338c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1339c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1340c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1341c50d8ae3SPaolo Bonzini { 134289212919SKeqian Zhu /* 134389212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 134489212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 134589212919SKeqian Zhu * are split to 4K on the first write. 134689212919SKeqian Zhu * 134789212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 134889212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 134989212919SKeqian Zhu * pages. 135089212919SKeqian Zhu */ 135189212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 135289212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 135389212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 135489212919SKeqian Zhu 1355cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1356cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1357cb00a70bSDavid Matlack 135889212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 135989212919SKeqian Zhu 136089212919SKeqian Zhu /* Cross two large pages? */ 136189212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 136289212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 136389212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 136489212919SKeqian Zhu PG_LEVEL_2M); 136589212919SKeqian Zhu } 136689212919SKeqian Zhu 136789212919SKeqian Zhu /* Now handle 4K PTEs. */ 1368a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1369a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1370c50d8ae3SPaolo Bonzini else 1371c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1372c50d8ae3SPaolo Bonzini } 1373c50d8ae3SPaolo Bonzini 1374fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1375fb04a1edSPeter Xu { 13766dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1377fb04a1edSPeter Xu } 1378fb04a1edSPeter Xu 1379c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13803ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13813ad93562SKeqian Zhu int min_level) 1382c50d8ae3SPaolo Bonzini { 1383c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1384c50d8ae3SPaolo Bonzini int i; 1385c50d8ae3SPaolo Bonzini bool write_protected = false; 1386c50d8ae3SPaolo Bonzini 1387e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13883ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 138993e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13901346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1391c50d8ae3SPaolo Bonzini } 1392e2209710SBen Gardon } 1393c50d8ae3SPaolo Bonzini 1394897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 139546044f72SBen Gardon write_protected |= 13963ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 139746044f72SBen Gardon 1398c50d8ae3SPaolo Bonzini return write_protected; 1399c50d8ae3SPaolo Bonzini } 1400c50d8ae3SPaolo Bonzini 1401cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1402c50d8ae3SPaolo Bonzini { 1403c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1404c50d8ae3SPaolo Bonzini 1405c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 14063ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1407c50d8ae3SPaolo Bonzini } 1408c50d8ae3SPaolo Bonzini 14090a234f5dSSean Christopherson static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1410269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1411c50d8ae3SPaolo Bonzini { 141271f51d2cSMingwei Zhang return pte_list_destroy(kvm, rmap_head); 1413c50d8ae3SPaolo Bonzini } 1414c50d8ae3SPaolo Bonzini 14153039bcc7SSean Christopherson static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1416c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14173039bcc7SSean Christopherson pte_t unused) 1418c50d8ae3SPaolo Bonzini { 14190a234f5dSSean Christopherson return kvm_zap_rmapp(kvm, rmap_head, slot); 1420c50d8ae3SPaolo Bonzini } 1421c50d8ae3SPaolo Bonzini 14223039bcc7SSean Christopherson static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1423c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14243039bcc7SSean Christopherson pte_t pte) 1425c50d8ae3SPaolo Bonzini { 1426c50d8ae3SPaolo Bonzini u64 *sptep; 1427c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 142898a26b69SVihas Mak bool need_flush = false; 1429c50d8ae3SPaolo Bonzini u64 new_spte; 1430c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1431c50d8ae3SPaolo Bonzini 14323039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14333039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1434c50d8ae3SPaolo Bonzini 1435c50d8ae3SPaolo Bonzini restart: 1436c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1437805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1438c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1439c50d8ae3SPaolo Bonzini 144098a26b69SVihas Mak need_flush = true; 1441c50d8ae3SPaolo Bonzini 14423039bcc7SSean Christopherson if (pte_write(pte)) { 144371f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 1444c50d8ae3SPaolo Bonzini goto restart; 1445c50d8ae3SPaolo Bonzini } else { 1446cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1447cb3eedabSPaolo Bonzini *sptep, new_pfn); 1448c50d8ae3SPaolo Bonzini 144971f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1450c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1451c50d8ae3SPaolo Bonzini } 1452c50d8ae3SPaolo Bonzini } 1453c50d8ae3SPaolo Bonzini 1454c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1455c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 145698a26b69SVihas Mak return false; 1457c50d8ae3SPaolo Bonzini } 1458c50d8ae3SPaolo Bonzini 1459c50d8ae3SPaolo Bonzini return need_flush; 1460c50d8ae3SPaolo Bonzini } 1461c50d8ae3SPaolo Bonzini 1462c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1463c50d8ae3SPaolo Bonzini /* input fields. */ 1464269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1465c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1466c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1467c50d8ae3SPaolo Bonzini int start_level; 1468c50d8ae3SPaolo Bonzini int end_level; 1469c50d8ae3SPaolo Bonzini 1470c50d8ae3SPaolo Bonzini /* output fields. */ 1471c50d8ae3SPaolo Bonzini gfn_t gfn; 1472c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1473c50d8ae3SPaolo Bonzini int level; 1474c50d8ae3SPaolo Bonzini 1475c50d8ae3SPaolo Bonzini /* private field. */ 1476c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1477c50d8ae3SPaolo Bonzini }; 1478c50d8ae3SPaolo Bonzini 1479c50d8ae3SPaolo Bonzini static void 1480c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1481c50d8ae3SPaolo Bonzini { 1482c50d8ae3SPaolo Bonzini iterator->level = level; 1483c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 148493e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 148593e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1486c50d8ae3SPaolo Bonzini } 1487c50d8ae3SPaolo Bonzini 1488c50d8ae3SPaolo Bonzini static void 1489c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1490269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1491c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1492c50d8ae3SPaolo Bonzini { 1493c50d8ae3SPaolo Bonzini iterator->slot = slot; 1494c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1495c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1496c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1497c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1498c50d8ae3SPaolo Bonzini 1499c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1500c50d8ae3SPaolo Bonzini } 1501c50d8ae3SPaolo Bonzini 1502c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1503c50d8ae3SPaolo Bonzini { 1504c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1505c50d8ae3SPaolo Bonzini } 1506c50d8ae3SPaolo Bonzini 1507c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1508c50d8ae3SPaolo Bonzini { 1509c50d8ae3SPaolo Bonzini if (++iterator->rmap <= iterator->end_rmap) { 1510c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 1511c50d8ae3SPaolo Bonzini return; 1512c50d8ae3SPaolo Bonzini } 1513c50d8ae3SPaolo Bonzini 1514c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1515c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1516c50d8ae3SPaolo Bonzini return; 1517c50d8ae3SPaolo Bonzini } 1518c50d8ae3SPaolo Bonzini 1519c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1520c50d8ae3SPaolo Bonzini } 1521c50d8ae3SPaolo Bonzini 1522c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1523c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1524c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1525c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1526c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1527c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1528c50d8ae3SPaolo Bonzini 15293039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1530c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15313039bcc7SSean Christopherson int level, pte_t pte); 1532c1b91493SSean Christopherson 15333039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15343039bcc7SSean Christopherson struct kvm_gfn_range *range, 1535c1b91493SSean Christopherson rmap_handler_t handler) 1536c50d8ae3SPaolo Bonzini { 1537c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15383039bcc7SSean Christopherson bool ret = false; 1539c50d8ae3SPaolo Bonzini 15403039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15413039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15423039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15433039bcc7SSean Christopherson iterator.level, range->pte); 1544c50d8ae3SPaolo Bonzini 1545c50d8ae3SPaolo Bonzini return ret; 1546c50d8ae3SPaolo Bonzini } 1547c50d8ae3SPaolo Bonzini 15483039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1549c50d8ae3SPaolo Bonzini { 1550e2209710SBen Gardon bool flush = false; 1551c50d8ae3SPaolo Bonzini 1552e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15533039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp); 1554063afacdSBen Gardon 1555897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1556c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1557063afacdSBen Gardon 15583039bcc7SSean Christopherson return flush; 1559c50d8ae3SPaolo Bonzini } 1560c50d8ae3SPaolo Bonzini 15613039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1562c50d8ae3SPaolo Bonzini { 1563e2209710SBen Gardon bool flush = false; 15641d8dd6b3SBen Gardon 1565e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15663039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp); 15671d8dd6b3SBen Gardon 1568897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15693039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15701d8dd6b3SBen Gardon 15713039bcc7SSean Christopherson return flush; 1572c50d8ae3SPaolo Bonzini } 1573c50d8ae3SPaolo Bonzini 15743039bcc7SSean Christopherson static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1575c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15763039bcc7SSean Christopherson pte_t unused) 1577c50d8ae3SPaolo Bonzini { 1578c50d8ae3SPaolo Bonzini u64 *sptep; 15793f649ab7SKees Cook struct rmap_iterator iter; 1580c50d8ae3SPaolo Bonzini int young = 0; 1581c50d8ae3SPaolo Bonzini 1582c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1583c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1584c50d8ae3SPaolo Bonzini 1585c50d8ae3SPaolo Bonzini return young; 1586c50d8ae3SPaolo Bonzini } 1587c50d8ae3SPaolo Bonzini 15883039bcc7SSean Christopherson static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1589c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15903039bcc7SSean Christopherson int level, pte_t unused) 1591c50d8ae3SPaolo Bonzini { 1592c50d8ae3SPaolo Bonzini u64 *sptep; 1593c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1594c50d8ae3SPaolo Bonzini 1595c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1596c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 159798a26b69SVihas Mak return true; 159898a26b69SVihas Mak return false; 1599c50d8ae3SPaolo Bonzini } 1600c50d8ae3SPaolo Bonzini 1601c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1602c50d8ae3SPaolo Bonzini 16038a9f566aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 16048a9f566aSDavid Matlack u64 *spte, gfn_t gfn) 1605c50d8ae3SPaolo Bonzini { 1606c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 160768be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 160868be1306SDavid Matlack int rmap_count; 1609c50d8ae3SPaolo Bonzini 161057354682SSean Christopherson sp = sptep_to_sp(spte); 161168be1306SDavid Matlack kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn); 161293e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 161368be1306SDavid Matlack rmap_count = pte_list_add(vcpu, spte, rmap_head); 1614c50d8ae3SPaolo Bonzini 161568be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16163039bcc7SSean Christopherson kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0)); 161768be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 161868be1306SDavid Matlack vcpu->kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 161968be1306SDavid Matlack } 1620c50d8ae3SPaolo Bonzini } 1621c50d8ae3SPaolo Bonzini 16223039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1623c50d8ae3SPaolo Bonzini { 1624e2209710SBen Gardon bool young = false; 1625f8e14497SBen Gardon 1626e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16273039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp); 16283039bcc7SSean Christopherson 1629897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16303039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1631f8e14497SBen Gardon 1632f8e14497SBen Gardon return young; 1633c50d8ae3SPaolo Bonzini } 1634c50d8ae3SPaolo Bonzini 16353039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1636c50d8ae3SPaolo Bonzini { 1637e2209710SBen Gardon bool young = false; 1638f8e14497SBen Gardon 1639e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16403039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp); 16413039bcc7SSean Christopherson 1642897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16433039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1644f8e14497SBen Gardon 1645f8e14497SBen Gardon return young; 1646c50d8ae3SPaolo Bonzini } 1647c50d8ae3SPaolo Bonzini 1648c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1649c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1650c50d8ae3SPaolo Bonzini { 1651c50d8ae3SPaolo Bonzini u64 *pos; 1652c50d8ae3SPaolo Bonzini u64 *end; 1653c50d8ae3SPaolo Bonzini 1654c50d8ae3SPaolo Bonzini for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) 1655c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1656c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1657c50d8ae3SPaolo Bonzini pos, *pos); 1658c50d8ae3SPaolo Bonzini return 0; 1659c50d8ae3SPaolo Bonzini } 1660c50d8ae3SPaolo Bonzini return 1; 1661c50d8ae3SPaolo Bonzini } 1662c50d8ae3SPaolo Bonzini #endif 1663c50d8ae3SPaolo Bonzini 1664c50d8ae3SPaolo Bonzini /* 1665c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1666c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1667c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1668c50d8ae3SPaolo Bonzini * faster 1669c50d8ae3SPaolo Bonzini */ 1670d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1671c50d8ae3SPaolo Bonzini { 1672c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1673c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1674c50d8ae3SPaolo Bonzini } 1675c50d8ae3SPaolo Bonzini 1676c50d8ae3SPaolo Bonzini static void kvm_mmu_free_page(struct kvm_mmu_page *sp) 1677c50d8ae3SPaolo Bonzini { 1678c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1679c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1680c50d8ae3SPaolo Bonzini list_del(&sp->link); 1681c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1682c50d8ae3SPaolo Bonzini if (!sp->role.direct) 1683c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->gfns); 1684c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1685c50d8ae3SPaolo Bonzini } 1686c50d8ae3SPaolo Bonzini 1687c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1688c50d8ae3SPaolo Bonzini { 1689c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1690c50d8ae3SPaolo Bonzini } 1691c50d8ae3SPaolo Bonzini 1692c50d8ae3SPaolo Bonzini static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, 1693c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1694c50d8ae3SPaolo Bonzini { 1695c50d8ae3SPaolo Bonzini if (!parent_pte) 1696c50d8ae3SPaolo Bonzini return; 1697c50d8ae3SPaolo Bonzini 1698c50d8ae3SPaolo Bonzini pte_list_add(vcpu, parent_pte, &sp->parent_ptes); 1699c50d8ae3SPaolo Bonzini } 1700c50d8ae3SPaolo Bonzini 1701c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1702c50d8ae3SPaolo Bonzini u64 *parent_pte) 1703c50d8ae3SPaolo Bonzini { 1704c50d8ae3SPaolo Bonzini __pte_list_remove(parent_pte, &sp->parent_ptes); 1705c50d8ae3SPaolo Bonzini } 1706c50d8ae3SPaolo Bonzini 1707c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1708c50d8ae3SPaolo Bonzini u64 *parent_pte) 1709c50d8ae3SPaolo Bonzini { 1710c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1711c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1712c50d8ae3SPaolo Bonzini } 1713c50d8ae3SPaolo Bonzini 1714c50d8ae3SPaolo Bonzini static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct) 1715c50d8ae3SPaolo Bonzini { 1716c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1717c50d8ae3SPaolo Bonzini 171894ce87efSSean Christopherson sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache); 171994ce87efSSean Christopherson sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache); 1720c50d8ae3SPaolo Bonzini if (!direct) 172194ce87efSSean Christopherson sp->gfns = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache); 1722c50d8ae3SPaolo Bonzini set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 1723c50d8ae3SPaolo Bonzini 1724c50d8ae3SPaolo Bonzini /* 1725c50d8ae3SPaolo Bonzini * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 1726c50d8ae3SPaolo Bonzini * depends on valid pages being added to the head of the list. See 1727c50d8ae3SPaolo Bonzini * comments in kvm_zap_obsolete_pages(). 1728c50d8ae3SPaolo Bonzini */ 1729c50d8ae3SPaolo Bonzini sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; 1730c50d8ae3SPaolo Bonzini list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); 1731c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(vcpu->kvm, +1); 1732c50d8ae3SPaolo Bonzini return sp; 1733c50d8ae3SPaolo Bonzini } 1734c50d8ae3SPaolo Bonzini 1735c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1736c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1737c50d8ae3SPaolo Bonzini { 1738c50d8ae3SPaolo Bonzini u64 *sptep; 1739c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1740c50d8ae3SPaolo Bonzini 1741c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1742c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1743c50d8ae3SPaolo Bonzini } 1744c50d8ae3SPaolo Bonzini } 1745c50d8ae3SPaolo Bonzini 1746c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1747c50d8ae3SPaolo Bonzini { 1748c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1749c50d8ae3SPaolo Bonzini unsigned int index; 1750c50d8ae3SPaolo Bonzini 175157354682SSean Christopherson sp = sptep_to_sp(spte); 1752c50d8ae3SPaolo Bonzini index = spte - sp->spt; 1753c50d8ae3SPaolo Bonzini if (__test_and_set_bit(index, sp->unsync_child_bitmap)) 1754c50d8ae3SPaolo Bonzini return; 1755c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1756c50d8ae3SPaolo Bonzini return; 1757c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1758c50d8ae3SPaolo Bonzini } 1759c50d8ae3SPaolo Bonzini 1760c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1761c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1762c50d8ae3SPaolo Bonzini { 1763c3e5e415SLai Jiangshan return -1; 1764c50d8ae3SPaolo Bonzini } 1765c50d8ae3SPaolo Bonzini 1766c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1767c50d8ae3SPaolo Bonzini 1768c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1769c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1770c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1771c50d8ae3SPaolo Bonzini unsigned int idx; 1772c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1773c50d8ae3SPaolo Bonzini unsigned int nr; 1774c50d8ae3SPaolo Bonzini }; 1775c50d8ae3SPaolo Bonzini 1776c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1777c50d8ae3SPaolo Bonzini int idx) 1778c50d8ae3SPaolo Bonzini { 1779c50d8ae3SPaolo Bonzini int i; 1780c50d8ae3SPaolo Bonzini 1781c50d8ae3SPaolo Bonzini if (sp->unsync) 1782c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1783c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1784c50d8ae3SPaolo Bonzini return 0; 1785c50d8ae3SPaolo Bonzini 1786c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1787c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1788c50d8ae3SPaolo Bonzini pvec->nr++; 1789c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1790c50d8ae3SPaolo Bonzini } 1791c50d8ae3SPaolo Bonzini 1792c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1793c50d8ae3SPaolo Bonzini { 1794c50d8ae3SPaolo Bonzini --sp->unsync_children; 1795c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1796c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1797c50d8ae3SPaolo Bonzini } 1798c50d8ae3SPaolo Bonzini 1799c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1800c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1801c50d8ae3SPaolo Bonzini { 1802c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1803c50d8ae3SPaolo Bonzini 1804c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1805c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1806c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1807c50d8ae3SPaolo Bonzini 1808c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1809c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1810c50d8ae3SPaolo Bonzini continue; 1811c50d8ae3SPaolo Bonzini } 1812c50d8ae3SPaolo Bonzini 1813e47c4aeeSSean Christopherson child = to_shadow_page(ent & PT64_BASE_ADDR_MASK); 1814c50d8ae3SPaolo Bonzini 1815c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1816c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1817c50d8ae3SPaolo Bonzini return -ENOSPC; 1818c50d8ae3SPaolo Bonzini 1819c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1820c50d8ae3SPaolo Bonzini if (!ret) { 1821c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1822c50d8ae3SPaolo Bonzini continue; 1823c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1824c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1825c50d8ae3SPaolo Bonzini } else 1826c50d8ae3SPaolo Bonzini return ret; 1827c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1828c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1829c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1830c50d8ae3SPaolo Bonzini return -ENOSPC; 1831c50d8ae3SPaolo Bonzini } else 1832c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1833c50d8ae3SPaolo Bonzini } 1834c50d8ae3SPaolo Bonzini 1835c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1836c50d8ae3SPaolo Bonzini } 1837c50d8ae3SPaolo Bonzini 1838c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1839c50d8ae3SPaolo Bonzini 1840c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1841c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1842c50d8ae3SPaolo Bonzini { 1843c50d8ae3SPaolo Bonzini pvec->nr = 0; 1844c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1845c50d8ae3SPaolo Bonzini return 0; 1846c50d8ae3SPaolo Bonzini 1847c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1848c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1849c50d8ae3SPaolo Bonzini } 1850c50d8ae3SPaolo Bonzini 1851c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1852c50d8ae3SPaolo Bonzini { 1853c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1854c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1855c50d8ae3SPaolo Bonzini sp->unsync = 0; 1856c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1857c50d8ae3SPaolo Bonzini } 1858c50d8ae3SPaolo Bonzini 1859c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1860c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1861c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1862c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1863c50d8ae3SPaolo Bonzini 1864767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1865767d8d8dSLai Jiangshan { 1866767d8d8dSLai Jiangshan if (sp->role.direct) 1867767d8d8dSLai Jiangshan return false; 1868767d8d8dSLai Jiangshan 1869*84e5ffd0SLai Jiangshan if (sp->role.passthrough) 1870*84e5ffd0SLai Jiangshan return false; 1871*84e5ffd0SLai Jiangshan 1872767d8d8dSLai Jiangshan return true; 1873767d8d8dSLai Jiangshan } 1874767d8d8dSLai Jiangshan 1875ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1876ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1877c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1878c50d8ae3SPaolo Bonzini } else 1879c50d8ae3SPaolo Bonzini 1880767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1881ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1882ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1883767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1884c50d8ae3SPaolo Bonzini 18858d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1886c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1887c50d8ae3SPaolo Bonzini { 1888c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1889c3e5e415SLai Jiangshan 18908d5678a7SHou Wenlong if (ret < 0) 1891c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18928d5678a7SHou Wenlong return ret; 1893c50d8ae3SPaolo Bonzini } 1894c50d8ae3SPaolo Bonzini 1895c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1896c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1897c50d8ae3SPaolo Bonzini bool remote_flush) 1898c50d8ae3SPaolo Bonzini { 1899c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1900c50d8ae3SPaolo Bonzini return false; 1901c50d8ae3SPaolo Bonzini 1902c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1903c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1904c50d8ae3SPaolo Bonzini else 1905c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1906c50d8ae3SPaolo Bonzini return true; 1907c50d8ae3SPaolo Bonzini } 1908c50d8ae3SPaolo Bonzini 1909c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1910c50d8ae3SPaolo Bonzini { 1911a955cad8SSean Christopherson if (sp->role.invalid) 1912a955cad8SSean Christopherson return true; 1913a955cad8SSean Christopherson 1914a955cad8SSean Christopherson /* TDP MMU pages due not use the MMU generation. */ 1915a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1916c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1917c50d8ae3SPaolo Bonzini } 1918c50d8ae3SPaolo Bonzini 1919c50d8ae3SPaolo Bonzini struct mmu_page_path { 1920c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1921c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1922c50d8ae3SPaolo Bonzini }; 1923c50d8ae3SPaolo Bonzini 1924c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1925c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1926c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1927c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1928c50d8ae3SPaolo Bonzini 1929c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1930c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1931c50d8ae3SPaolo Bonzini int i) 1932c50d8ae3SPaolo Bonzini { 1933c50d8ae3SPaolo Bonzini int n; 1934c50d8ae3SPaolo Bonzini 1935c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1936c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1937c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1938c50d8ae3SPaolo Bonzini int level = sp->role.level; 1939c50d8ae3SPaolo Bonzini 1940c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19413bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1942c50d8ae3SPaolo Bonzini break; 1943c50d8ae3SPaolo Bonzini 1944c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1945c50d8ae3SPaolo Bonzini } 1946c50d8ae3SPaolo Bonzini 1947c50d8ae3SPaolo Bonzini return n; 1948c50d8ae3SPaolo Bonzini } 1949c50d8ae3SPaolo Bonzini 1950c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1951c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1952c50d8ae3SPaolo Bonzini { 1953c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1954c50d8ae3SPaolo Bonzini int level; 1955c50d8ae3SPaolo Bonzini 1956c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1957c50d8ae3SPaolo Bonzini return 0; 1958c50d8ae3SPaolo Bonzini 1959c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1960c50d8ae3SPaolo Bonzini 1961c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1962c50d8ae3SPaolo Bonzini level = sp->role.level; 19633bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1964c50d8ae3SPaolo Bonzini 1965c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1966c50d8ae3SPaolo Bonzini 1967c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1968c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1969c50d8ae3SPaolo Bonzini */ 1970c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1971c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1972c50d8ae3SPaolo Bonzini } 1973c50d8ae3SPaolo Bonzini 1974c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1975c50d8ae3SPaolo Bonzini { 1976c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1977c50d8ae3SPaolo Bonzini unsigned int level = 0; 1978c50d8ae3SPaolo Bonzini 1979c50d8ae3SPaolo Bonzini do { 1980c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1981c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1982c50d8ae3SPaolo Bonzini if (!sp) 1983c50d8ae3SPaolo Bonzini return; 1984c50d8ae3SPaolo Bonzini 1985c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1986c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1987c50d8ae3SPaolo Bonzini level++; 1988c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1989c50d8ae3SPaolo Bonzini } 1990c50d8ae3SPaolo Bonzini 199165855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 199265855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1993c50d8ae3SPaolo Bonzini { 1994c50d8ae3SPaolo Bonzini int i; 1995c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1996c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1997c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1998c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1999c50d8ae3SPaolo Bonzini bool flush = false; 2000c50d8ae3SPaolo Bonzini 2001c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2002c50d8ae3SPaolo Bonzini bool protected = false; 2003c50d8ae3SPaolo Bonzini 2004c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 2005cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 2006c50d8ae3SPaolo Bonzini 2007c50d8ae3SPaolo Bonzini if (protected) { 20085591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 2009c50d8ae3SPaolo Bonzini flush = false; 2010c50d8ae3SPaolo Bonzini } 2011c50d8ae3SPaolo Bonzini 2012c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2013479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 20148d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 2015c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2016c50d8ae3SPaolo Bonzini } 2017531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2018c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 201965855ed8SLai Jiangshan if (!can_yield) { 202065855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 202165855ed8SLai Jiangshan return -EINTR; 202265855ed8SLai Jiangshan } 202365855ed8SLai Jiangshan 2024531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2025c50d8ae3SPaolo Bonzini flush = false; 2026c50d8ae3SPaolo Bonzini } 2027c50d8ae3SPaolo Bonzini } 2028c50d8ae3SPaolo Bonzini 2029c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 203065855ed8SLai Jiangshan return 0; 2031c50d8ae3SPaolo Bonzini } 2032c50d8ae3SPaolo Bonzini 2033c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2034c50d8ae3SPaolo Bonzini { 2035c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2036c50d8ae3SPaolo Bonzini } 2037c50d8ae3SPaolo Bonzini 2038c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2039c50d8ae3SPaolo Bonzini { 204057354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2041c50d8ae3SPaolo Bonzini } 2042c50d8ae3SPaolo Bonzini 2043c50d8ae3SPaolo Bonzini static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, 2044c50d8ae3SPaolo Bonzini gfn_t gfn, 2045c50d8ae3SPaolo Bonzini gva_t gaddr, 2046c50d8ae3SPaolo Bonzini unsigned level, 2047c50d8ae3SPaolo Bonzini int direct, 20480a2b64c5SBen Gardon unsigned int access) 2049c50d8ae3SPaolo Bonzini { 2050347a0d0dSPaolo Bonzini bool direct_mmu = vcpu->arch.mmu->root_role.direct; 2051c50d8ae3SPaolo Bonzini union kvm_mmu_page_role role; 2052ac101b7cSSean Christopherson struct hlist_head *sp_list; 2053c50d8ae3SPaolo Bonzini unsigned quadrant; 2054c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20558d5678a7SHou Wenlong int ret; 2056c50d8ae3SPaolo Bonzini int collisions = 0; 2057c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2058c50d8ae3SPaolo Bonzini 20597a458f0eSPaolo Bonzini role = vcpu->arch.mmu->root_role; 2060c50d8ae3SPaolo Bonzini role.level = level; 2061c50d8ae3SPaolo Bonzini role.direct = direct; 2062c50d8ae3SPaolo Bonzini role.access = access; 2063bb3b394dSLai Jiangshan if (role.has_4_byte_gpte) { 2064c50d8ae3SPaolo Bonzini quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level)); 2065c50d8ae3SPaolo Bonzini quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; 2066c50d8ae3SPaolo Bonzini role.quadrant = quadrant; 2067c50d8ae3SPaolo Bonzini } 2068*84e5ffd0SLai Jiangshan if (level <= vcpu->arch.mmu->cpu_role.base.level) 2069*84e5ffd0SLai Jiangshan role.passthrough = 0; 2070ac101b7cSSean Christopherson 2071ac101b7cSSean Christopherson sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 2072ac101b7cSSean Christopherson for_each_valid_sp(vcpu->kvm, sp, sp_list) { 2073c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2074c50d8ae3SPaolo Bonzini collisions++; 2075c50d8ae3SPaolo Bonzini continue; 2076c50d8ae3SPaolo Bonzini } 2077c50d8ae3SPaolo Bonzini 2078ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2079ddc16abbSSean Christopherson /* 2080ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2081ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2082ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2083ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2084ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2085ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2086ddc16abbSSean Christopherson * upper-level page will be write-protected. 2087ddc16abbSSean Christopherson */ 2088ddc16abbSSean Christopherson if (level > PG_LEVEL_4K && sp->unsync) 2089ddc16abbSSean Christopherson kvm_mmu_prepare_zap_page(vcpu->kvm, sp, 2090ddc16abbSSean Christopherson &invalid_list); 2091c50d8ae3SPaolo Bonzini continue; 2092ddc16abbSSean Christopherson } 2093c50d8ae3SPaolo Bonzini 2094fb58a9c3SSean Christopherson if (direct_mmu) 2095fb58a9c3SSean Christopherson goto trace_get_page; 2096fb58a9c3SSean Christopherson 2097c50d8ae3SPaolo Bonzini if (sp->unsync) { 209807dc4f35SSean Christopherson /* 2099479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 210007dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 210107dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 210207dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 210307dc4f35SSean Christopherson * overhead of write protection is not incurred until the 210407dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 210507dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 210607dc4f35SSean Christopherson * 210707dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 210807dc4f35SSean Christopherson * in order to rebuild it. 2109c50d8ae3SPaolo Bonzini */ 21108d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 21118d5678a7SHou Wenlong if (ret < 0) 2112c50d8ae3SPaolo Bonzini break; 2113c50d8ae3SPaolo Bonzini 2114c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 21158d5678a7SHou Wenlong if (ret > 0) 2116c3e5e415SLai Jiangshan kvm_flush_remote_tlbs(vcpu->kvm); 2117c50d8ae3SPaolo Bonzini } 2118c50d8ae3SPaolo Bonzini 2119c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2120fb58a9c3SSean Christopherson 2121fb58a9c3SSean Christopherson trace_get_page: 2122c50d8ae3SPaolo Bonzini trace_kvm_mmu_get_page(sp, false); 2123c50d8ae3SPaolo Bonzini goto out; 2124c50d8ae3SPaolo Bonzini } 2125c50d8ae3SPaolo Bonzini 2126c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_cache_miss; 2127c50d8ae3SPaolo Bonzini 2128c50d8ae3SPaolo Bonzini sp = kvm_mmu_alloc_page(vcpu, direct); 2129c50d8ae3SPaolo Bonzini 2130c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2131c50d8ae3SPaolo Bonzini sp->role = role; 2132ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2133767d8d8dSLai Jiangshan if (sp_has_gptes(sp)) { 2134c50d8ae3SPaolo Bonzini account_shadowed(vcpu->kvm, sp); 2135cf48f9e2SDavid Matlack if (level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn)) 2136c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1); 2137c50d8ae3SPaolo Bonzini } 2138c50d8ae3SPaolo Bonzini trace_kvm_mmu_get_page(sp, true); 2139c50d8ae3SPaolo Bonzini out: 2140ddc16abbSSean Christopherson kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); 2141ddc16abbSSean Christopherson 2142c50d8ae3SPaolo Bonzini if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions) 2143c50d8ae3SPaolo Bonzini vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions; 2144c50d8ae3SPaolo Bonzini return sp; 2145c50d8ae3SPaolo Bonzini } 2146c50d8ae3SPaolo Bonzini 2147c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2148c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2149c50d8ae3SPaolo Bonzini u64 addr) 2150c50d8ae3SPaolo Bonzini { 2151c50d8ae3SPaolo Bonzini iterator->addr = addr; 2152c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2153a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2154c50d8ae3SPaolo Bonzini 215512ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 21564d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2157347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 215812ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2159c50d8ae3SPaolo Bonzini 2160c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2161c50d8ae3SPaolo Bonzini /* 2162c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2163c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2164c50d8ae3SPaolo Bonzini */ 2165b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2166c50d8ae3SPaolo Bonzini 2167c50d8ae3SPaolo Bonzini iterator->shadow_addr 2168c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 2169c50d8ae3SPaolo Bonzini iterator->shadow_addr &= PT64_BASE_ADDR_MASK; 2170c50d8ae3SPaolo Bonzini --iterator->level; 2171c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2172c50d8ae3SPaolo Bonzini iterator->level = 0; 2173c50d8ae3SPaolo Bonzini } 2174c50d8ae3SPaolo Bonzini } 2175c50d8ae3SPaolo Bonzini 2176c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2177c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2178c50d8ae3SPaolo Bonzini { 2179b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2180c50d8ae3SPaolo Bonzini addr); 2181c50d8ae3SPaolo Bonzini } 2182c50d8ae3SPaolo Bonzini 2183c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2184c50d8ae3SPaolo Bonzini { 21853bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2186c50d8ae3SPaolo Bonzini return false; 2187c50d8ae3SPaolo Bonzini 2188c50d8ae3SPaolo Bonzini iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level); 2189c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2190c50d8ae3SPaolo Bonzini return true; 2191c50d8ae3SPaolo Bonzini } 2192c50d8ae3SPaolo Bonzini 2193c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2194c50d8ae3SPaolo Bonzini u64 spte) 2195c50d8ae3SPaolo Bonzini { 21963e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2197c50d8ae3SPaolo Bonzini iterator->level = 0; 2198c50d8ae3SPaolo Bonzini return; 2199c50d8ae3SPaolo Bonzini } 2200c50d8ae3SPaolo Bonzini 2201c50d8ae3SPaolo Bonzini iterator->shadow_addr = spte & PT64_BASE_ADDR_MASK; 2202c50d8ae3SPaolo Bonzini --iterator->level; 2203c50d8ae3SPaolo Bonzini } 2204c50d8ae3SPaolo Bonzini 2205c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2206c50d8ae3SPaolo Bonzini { 2207c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2208c50d8ae3SPaolo Bonzini } 2209c50d8ae3SPaolo Bonzini 2210c50d8ae3SPaolo Bonzini static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 2211c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 2212c50d8ae3SPaolo Bonzini { 2213c50d8ae3SPaolo Bonzini u64 spte; 2214c50d8ae3SPaolo Bonzini 2215c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2216c50d8ae3SPaolo Bonzini 2217cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2218c50d8ae3SPaolo Bonzini 2219c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2220c50d8ae3SPaolo Bonzini 2221c50d8ae3SPaolo Bonzini mmu_page_add_parent_pte(vcpu, sp, sptep); 2222c50d8ae3SPaolo Bonzini 2223c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2224c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2225c50d8ae3SPaolo Bonzini } 2226c50d8ae3SPaolo Bonzini 2227c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2228c50d8ae3SPaolo Bonzini unsigned direct_access) 2229c50d8ae3SPaolo Bonzini { 2230c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2231c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2232c50d8ae3SPaolo Bonzini 2233c50d8ae3SPaolo Bonzini /* 2234c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2235c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2236c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2237c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2238c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2239c50d8ae3SPaolo Bonzini */ 2240e47c4aeeSSean Christopherson child = to_shadow_page(*sptep & PT64_BASE_ADDR_MASK); 2241c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2242c50d8ae3SPaolo Bonzini return; 2243c50d8ae3SPaolo Bonzini 2244c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2245c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2246c50d8ae3SPaolo Bonzini } 2247c50d8ae3SPaolo Bonzini } 2248c50d8ae3SPaolo Bonzini 22492de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 22502de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 22512de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2252c50d8ae3SPaolo Bonzini { 2253c50d8ae3SPaolo Bonzini u64 pte; 2254c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2255c50d8ae3SPaolo Bonzini 2256c50d8ae3SPaolo Bonzini pte = *spte; 2257c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2258c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2259c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2260c50d8ae3SPaolo Bonzini } else { 2261e47c4aeeSSean Christopherson child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); 2262c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 22632de4085cSBen Gardon 22642de4085cSBen Gardon /* 22652de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 22662de4085cSBen Gardon * unlikely to be used again in the near future. This 22672de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 22682de4085cSBen Gardon */ 22692de4085cSBen Gardon if (tdp_enabled && invalid_list && 22702de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 22712de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 22722de4085cSBen Gardon invalid_list); 2273c50d8ae3SPaolo Bonzini } 2274ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2275c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2276ace569e0SSean Christopherson } 22772de4085cSBen Gardon return 0; 2278c50d8ae3SPaolo Bonzini } 2279c50d8ae3SPaolo Bonzini 22802de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 22812de4085cSBen Gardon struct kvm_mmu_page *sp, 22822de4085cSBen Gardon struct list_head *invalid_list) 2283c50d8ae3SPaolo Bonzini { 22842de4085cSBen Gardon int zapped = 0; 2285c50d8ae3SPaolo Bonzini unsigned i; 2286c50d8ae3SPaolo Bonzini 2287c50d8ae3SPaolo Bonzini for (i = 0; i < PT64_ENT_PER_PAGE; ++i) 22882de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 22892de4085cSBen Gardon 22902de4085cSBen Gardon return zapped; 2291c50d8ae3SPaolo Bonzini } 2292c50d8ae3SPaolo Bonzini 229361827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2294c50d8ae3SPaolo Bonzini { 2295c50d8ae3SPaolo Bonzini u64 *sptep; 2296c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2297c50d8ae3SPaolo Bonzini 2298c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2299c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2300c50d8ae3SPaolo Bonzini } 2301c50d8ae3SPaolo Bonzini 2302c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2303c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2304c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2305c50d8ae3SPaolo Bonzini { 2306c50d8ae3SPaolo Bonzini int i, zapped = 0; 2307c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2308c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2309c50d8ae3SPaolo Bonzini 23103bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2311c50d8ae3SPaolo Bonzini return 0; 2312c50d8ae3SPaolo Bonzini 2313c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2314c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2315c50d8ae3SPaolo Bonzini 2316c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2317c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2318c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2319c50d8ae3SPaolo Bonzini zapped++; 2320c50d8ae3SPaolo Bonzini } 2321c50d8ae3SPaolo Bonzini } 2322c50d8ae3SPaolo Bonzini 2323c50d8ae3SPaolo Bonzini return zapped; 2324c50d8ae3SPaolo Bonzini } 2325c50d8ae3SPaolo Bonzini 2326c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2327c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2328c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2329c50d8ae3SPaolo Bonzini int *nr_zapped) 2330c50d8ae3SPaolo Bonzini { 2331527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2332c50d8ae3SPaolo Bonzini 2333c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2334c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2335c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 23362de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 233761827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2338c50d8ae3SPaolo Bonzini 2339c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2340c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2341c50d8ae3SPaolo Bonzini 2342767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2343c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2344c50d8ae3SPaolo Bonzini 2345c50d8ae3SPaolo Bonzini if (sp->unsync) 2346c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2347c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2348c50d8ae3SPaolo Bonzini /* Count self */ 2349c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2350f95eec9bSSean Christopherson 2351f95eec9bSSean Christopherson /* 2352f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2353f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2354f95eec9bSSean Christopherson * !sp->root_count. 2355f95eec9bSSean Christopherson */ 2356f95eec9bSSean Christopherson if (sp->role.invalid) 2357f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2358f95eec9bSSean Christopherson else 2359c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 2360c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(kvm, -1); 2361c50d8ae3SPaolo Bonzini } else { 2362f95eec9bSSean Christopherson /* 2363f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2364f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2365f95eec9bSSean Christopherson */ 2366f95eec9bSSean Christopherson list_del(&sp->link); 2367c50d8ae3SPaolo Bonzini 2368c50d8ae3SPaolo Bonzini /* 2369c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2370c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2371c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2372c50d8ae3SPaolo Bonzini */ 2373527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2374c50d8ae3SPaolo Bonzini } 2375c50d8ae3SPaolo Bonzini 2376c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2377c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2378c50d8ae3SPaolo Bonzini 2379c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2380527d5cd7SSean Christopherson 2381527d5cd7SSean Christopherson /* 2382527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2383527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2384527d5cd7SSean Christopherson */ 2385527d5cd7SSean Christopherson if (zapped_root) 2386527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2387c50d8ae3SPaolo Bonzini return list_unstable; 2388c50d8ae3SPaolo Bonzini } 2389c50d8ae3SPaolo Bonzini 2390c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2391c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2392c50d8ae3SPaolo Bonzini { 2393c50d8ae3SPaolo Bonzini int nr_zapped; 2394c50d8ae3SPaolo Bonzini 2395c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2396c50d8ae3SPaolo Bonzini return nr_zapped; 2397c50d8ae3SPaolo Bonzini } 2398c50d8ae3SPaolo Bonzini 2399c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2400c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2401c50d8ae3SPaolo Bonzini { 2402c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2403c50d8ae3SPaolo Bonzini 2404c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2405c50d8ae3SPaolo Bonzini return; 2406c50d8ae3SPaolo Bonzini 2407c50d8ae3SPaolo Bonzini /* 2408c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2409c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2410c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2411c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2412c50d8ae3SPaolo Bonzini * 2413c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2414c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2415c50d8ae3SPaolo Bonzini */ 2416c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2417c50d8ae3SPaolo Bonzini 2418c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2419c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 2420c50d8ae3SPaolo Bonzini kvm_mmu_free_page(sp); 2421c50d8ae3SPaolo Bonzini } 2422c50d8ae3SPaolo Bonzini } 2423c50d8ae3SPaolo Bonzini 24246b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 24256b82ef2cSSean Christopherson unsigned long nr_to_zap) 2426c50d8ae3SPaolo Bonzini { 24276b82ef2cSSean Christopherson unsigned long total_zapped = 0; 24286b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2429ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 24306b82ef2cSSean Christopherson bool unstable; 24316b82ef2cSSean Christopherson int nr_zapped; 2432c50d8ae3SPaolo Bonzini 2433c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2434ba7888ddSSean Christopherson return 0; 2435c50d8ae3SPaolo Bonzini 24366b82ef2cSSean Christopherson restart: 24378fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 24386b82ef2cSSean Christopherson /* 24396b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 24406b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 24416b82ef2cSSean Christopherson */ 24426b82ef2cSSean Christopherson if (sp->root_count) 24436b82ef2cSSean Christopherson continue; 24446b82ef2cSSean Christopherson 24456b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 24466b82ef2cSSean Christopherson &nr_zapped); 24476b82ef2cSSean Christopherson total_zapped += nr_zapped; 24486b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2449ba7888ddSSean Christopherson break; 2450ba7888ddSSean Christopherson 24516b82ef2cSSean Christopherson if (unstable) 24526b82ef2cSSean Christopherson goto restart; 2453ba7888ddSSean Christopherson } 24546b82ef2cSSean Christopherson 24556b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 24566b82ef2cSSean Christopherson 24576b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 24586b82ef2cSSean Christopherson return total_zapped; 24596b82ef2cSSean Christopherson } 24606b82ef2cSSean Christopherson 2461afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2462afe8d7e6SSean Christopherson { 2463afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2464afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2465afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2466afe8d7e6SSean Christopherson 2467afe8d7e6SSean Christopherson return 0; 2468c50d8ae3SPaolo Bonzini } 2469c50d8ae3SPaolo Bonzini 2470ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2471ba7888ddSSean Christopherson { 24726b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2473ba7888ddSSean Christopherson 24746b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2475ba7888ddSSean Christopherson return 0; 2476ba7888ddSSean Christopherson 24776b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2478ba7888ddSSean Christopherson 24796e6ec584SSean Christopherson /* 24806e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 24816e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 24826e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 24836e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2484c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 24856e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 24866e6ec584SSean Christopherson * page fault paths. 24876e6ec584SSean Christopherson */ 2488ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2489ba7888ddSSean Christopherson return -ENOSPC; 2490ba7888ddSSean Christopherson return 0; 2491ba7888ddSSean Christopherson } 2492ba7888ddSSean Christopherson 2493c50d8ae3SPaolo Bonzini /* 2494c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2495c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2496c50d8ae3SPaolo Bonzini */ 2497c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2498c50d8ae3SPaolo Bonzini { 2499531810caSBen Gardon write_lock(&kvm->mmu_lock); 2500c50d8ae3SPaolo Bonzini 2501c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 25026b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 25036b82ef2cSSean Christopherson goal_nr_mmu_pages); 2504c50d8ae3SPaolo Bonzini 2505c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2506c50d8ae3SPaolo Bonzini } 2507c50d8ae3SPaolo Bonzini 2508c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2509c50d8ae3SPaolo Bonzini 2510531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2511c50d8ae3SPaolo Bonzini } 2512c50d8ae3SPaolo Bonzini 2513c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2514c50d8ae3SPaolo Bonzini { 2515c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2516c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2517c50d8ae3SPaolo Bonzini int r; 2518c50d8ae3SPaolo Bonzini 2519c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2520c50d8ae3SPaolo Bonzini r = 0; 2521531810caSBen Gardon write_lock(&kvm->mmu_lock); 2522767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2523c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2524c50d8ae3SPaolo Bonzini sp->role.word); 2525c50d8ae3SPaolo Bonzini r = 1; 2526c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2527c50d8ae3SPaolo Bonzini } 2528c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2529531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2530c50d8ae3SPaolo Bonzini 2531c50d8ae3SPaolo Bonzini return r; 2532c50d8ae3SPaolo Bonzini } 253396ad91aeSSean Christopherson 253496ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 253596ad91aeSSean Christopherson { 253696ad91aeSSean Christopherson gpa_t gpa; 253796ad91aeSSean Christopherson int r; 253896ad91aeSSean Christopherson 2539347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 254096ad91aeSSean Christopherson return 0; 254196ad91aeSSean Christopherson 254296ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 254396ad91aeSSean Christopherson 254496ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 254596ad91aeSSean Christopherson 254696ad91aeSSean Christopherson return r; 254796ad91aeSSean Christopherson } 2548c50d8ae3SPaolo Bonzini 25494d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2550c50d8ae3SPaolo Bonzini { 2551c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 25524d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2553c50d8ae3SPaolo Bonzini sp->unsync = 1; 2554c50d8ae3SPaolo Bonzini 2555c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2556c50d8ae3SPaolo Bonzini } 2557c50d8ae3SPaolo Bonzini 25580337f585SSean Christopherson /* 25590337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 25600337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 25610337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 25620337f585SSean Christopherson * be write-protected. 25630337f585SSean Christopherson */ 25648283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 25652839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2566c50d8ae3SPaolo Bonzini { 2567c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2568ce25681dSSean Christopherson bool locked = false; 2569c50d8ae3SPaolo Bonzini 25700337f585SSean Christopherson /* 25710337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 25720337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 25730337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 25740337f585SSean Christopherson */ 25754d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 25760337f585SSean Christopherson return -EPERM; 2577c50d8ae3SPaolo Bonzini 25780337f585SSean Christopherson /* 25790337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 25800337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 25810337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 25820337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 25830337f585SSean Christopherson */ 2584767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2585c50d8ae3SPaolo Bonzini if (!can_unsync) 25860337f585SSean Christopherson return -EPERM; 2587c50d8ae3SPaolo Bonzini 2588c50d8ae3SPaolo Bonzini if (sp->unsync) 2589c50d8ae3SPaolo Bonzini continue; 2590c50d8ae3SPaolo Bonzini 25912839180cSPaolo Bonzini if (prefetch) 2592f1c4a88cSLai Jiangshan return -EEXIST; 2593f1c4a88cSLai Jiangshan 2594ce25681dSSean Christopherson /* 2595ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2596ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2597ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2598ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2599ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2600ce25681dSSean Christopherson */ 2601ce25681dSSean Christopherson if (!locked) { 2602ce25681dSSean Christopherson locked = true; 26034d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2604ce25681dSSean Christopherson 2605ce25681dSSean Christopherson /* 2606ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2607ce25681dSSean Christopherson * may have since marked the page unsync. A false 2608ce25681dSSean Christopherson * positive on the unprotected check above is not 2609ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2610ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2611ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2612ce25681dSSean Christopherson */ 2613ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2614ce25681dSSean Christopherson continue; 2615ce25681dSSean Christopherson } 2616ce25681dSSean Christopherson 26173bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 26184d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2619c50d8ae3SPaolo Bonzini } 2620ce25681dSSean Christopherson if (locked) 26214d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2622c50d8ae3SPaolo Bonzini 2623c50d8ae3SPaolo Bonzini /* 2624c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2625c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2626c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2627c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2628c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2629c50d8ae3SPaolo Bonzini * following could happen: 2630c50d8ae3SPaolo Bonzini * 2631c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2632c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2633c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2634c50d8ae3SPaolo Bonzini * to be writable 2635c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2636c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2637c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2638c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2639c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2640c50d8ae3SPaolo Bonzini * fault. 2641c50d8ae3SPaolo Bonzini * 2642c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2643c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2644c50d8ae3SPaolo Bonzini * 26450337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 26460337f585SSean Christopherson * false and skips the page. 2647c50d8ae3SPaolo Bonzini * 2648c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2649c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2650c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2651c50d8ae3SPaolo Bonzini * gets used. 2652c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2653c50d8ae3SPaolo Bonzini * as unsync 2654c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2655c50d8ae3SPaolo Bonzini * 2656c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2657264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2658264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2659c50d8ae3SPaolo Bonzini */ 2660c50d8ae3SPaolo Bonzini smp_wmb(); 2661c50d8ae3SPaolo Bonzini 26620337f585SSean Christopherson return 0; 2663c50d8ae3SPaolo Bonzini } 2664c50d8ae3SPaolo Bonzini 26658a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 26668a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2667a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2668799a4190SBen Gardon { 2669d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2670eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2671c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2672c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2673c50d8ae3SPaolo Bonzini bool flush = false; 2674ad67e480SPaolo Bonzini bool wrprot; 2675d786c778SPaolo Bonzini u64 spte; 2676c50d8ae3SPaolo Bonzini 2677a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2678a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 26792839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2680a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2681c50d8ae3SPaolo Bonzini 2682c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2683c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2684c50d8ae3SPaolo Bonzini 2685a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 2686a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2687a54aa15cSSean Christopherson return RET_PF_EMULATE; 2688a54aa15cSSean Christopherson } 2689a54aa15cSSean Christopherson 2690c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2691c50d8ae3SPaolo Bonzini /* 2692c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2693c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2694c50d8ae3SPaolo Bonzini */ 26953bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2696c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2697c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2698c50d8ae3SPaolo Bonzini 2699e47c4aeeSSean Christopherson child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); 2700c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2701c50d8ae3SPaolo Bonzini flush = true; 2702c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2703c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2704c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2705c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2706c50d8ae3SPaolo Bonzini flush = true; 2707c50d8ae3SPaolo Bonzini } else 2708c50d8ae3SPaolo Bonzini was_rmapped = 1; 2709c50d8ae3SPaolo Bonzini } 2710c50d8ae3SPaolo Bonzini 27112839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 27127158bee4SPaolo Bonzini true, host_writable, &spte); 2713d786c778SPaolo Bonzini 2714d786c778SPaolo Bonzini if (*sptep == spte) { 2715d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2716d786c778SPaolo Bonzini } else { 2717d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 27185959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2719c50d8ae3SPaolo Bonzini } 2720c50d8ae3SPaolo Bonzini 2721ad67e480SPaolo Bonzini if (wrprot) { 2722c50d8ae3SPaolo Bonzini if (write_fault) 2723c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2724c50d8ae3SPaolo Bonzini } 2725c50d8ae3SPaolo Bonzini 2726d786c778SPaolo Bonzini if (flush) 2727c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2728c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2729c50d8ae3SPaolo Bonzini 2730c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2731c50d8ae3SPaolo Bonzini 2732c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2733d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 273471f51d2cSMingwei Zhang kvm_update_page_stats(vcpu->kvm, level, 1); 27358a9f566aSDavid Matlack rmap_add(vcpu, slot, sptep, gfn); 2736c50d8ae3SPaolo Bonzini } 2737c50d8ae3SPaolo Bonzini 2738c50d8ae3SPaolo Bonzini return ret; 2739c50d8ae3SPaolo Bonzini } 2740c50d8ae3SPaolo Bonzini 2741c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2742c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2743c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2744c50d8ae3SPaolo Bonzini { 2745c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2746c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 27470a2b64c5SBen Gardon unsigned int access = sp->role.access; 2748c50d8ae3SPaolo Bonzini int i, ret; 2749c50d8ae3SPaolo Bonzini gfn_t gfn; 2750c50d8ae3SPaolo Bonzini 2751c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt); 2752c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2753c50d8ae3SPaolo Bonzini if (!slot) 2754c50d8ae3SPaolo Bonzini return -1; 2755c50d8ae3SPaolo Bonzini 2756c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2757c50d8ae3SPaolo Bonzini if (ret <= 0) 2758c50d8ae3SPaolo Bonzini return -1; 2759c50d8ae3SPaolo Bonzini 2760c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 27618a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2762a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2763c50d8ae3SPaolo Bonzini put_page(pages[i]); 2764c50d8ae3SPaolo Bonzini } 2765c50d8ae3SPaolo Bonzini 2766c50d8ae3SPaolo Bonzini return 0; 2767c50d8ae3SPaolo Bonzini } 2768c50d8ae3SPaolo Bonzini 2769c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2770c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2771c50d8ae3SPaolo Bonzini { 2772c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2773c50d8ae3SPaolo Bonzini int i; 2774c50d8ae3SPaolo Bonzini 2775c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2776c50d8ae3SPaolo Bonzini 2777c50d8ae3SPaolo Bonzini i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); 2778c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2779c50d8ae3SPaolo Bonzini 2780c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2781c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2782c50d8ae3SPaolo Bonzini if (!start) 2783c50d8ae3SPaolo Bonzini continue; 2784c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2785c6cecc4bSSean Christopherson return; 2786c50d8ae3SPaolo Bonzini start = NULL; 2787c50d8ae3SPaolo Bonzini } else if (!start) 2788c50d8ae3SPaolo Bonzini start = spte; 2789c50d8ae3SPaolo Bonzini } 2790c6cecc4bSSean Christopherson if (start) 2791c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2792c50d8ae3SPaolo Bonzini } 2793c50d8ae3SPaolo Bonzini 2794c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2795c50d8ae3SPaolo Bonzini { 2796c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2797c50d8ae3SPaolo Bonzini 279857354682SSean Christopherson sp = sptep_to_sp(sptep); 2799c50d8ae3SPaolo Bonzini 2800c50d8ae3SPaolo Bonzini /* 2801c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2802c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2803c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2804c50d8ae3SPaolo Bonzini */ 2805c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2806c50d8ae3SPaolo Bonzini return; 2807c50d8ae3SPaolo Bonzini 28083bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2809c50d8ae3SPaolo Bonzini return; 2810c50d8ae3SPaolo Bonzini 28114a42d848SDavid Stevens /* 28124a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 28134a42d848SDavid Stevens * accidentally prefetching those addresses. 28144a42d848SDavid Stevens */ 28154a42d848SDavid Stevens if (unlikely(vcpu->kvm->mmu_notifier_count)) 28164a42d848SDavid Stevens return; 28174a42d848SDavid Stevens 2818c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2819c50d8ae3SPaolo Bonzini } 2820c50d8ae3SPaolo Bonzini 28211b6d9d9eSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, 28228ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2823db543216SSean Christopherson { 2824db543216SSean Christopherson unsigned long hva; 282544187235SMingwei Zhang unsigned long flags; 282644187235SMingwei Zhang int level = PG_LEVEL_4K; 282744187235SMingwei Zhang pgd_t pgd; 282844187235SMingwei Zhang p4d_t p4d; 282944187235SMingwei Zhang pud_t pud; 283044187235SMingwei Zhang pmd_t pmd; 2831db543216SSean Christopherson 2832e851265aSSean Christopherson if (!PageCompound(pfn_to_page(pfn)) && !kvm_is_zone_device_pfn(pfn)) 28333bae0459SSean Christopherson return PG_LEVEL_4K; 2834db543216SSean Christopherson 2835293e306eSSean Christopherson /* 2836293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2837293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2838293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2839293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2840293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2841293e306eSSean Christopherson * read-only memslot. 2842293e306eSSean Christopherson */ 2843db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2844db543216SSean Christopherson 284544187235SMingwei Zhang /* 284644187235SMingwei Zhang * Lookup the mapping level in the current mm. The information 284744187235SMingwei Zhang * may become stale soon, but it is safe to use as long as 284844187235SMingwei Zhang * 1) mmu_notifier_retry was checked after taking mmu_lock, and 284944187235SMingwei Zhang * 2) mmu_lock is taken now. 285044187235SMingwei Zhang * 285144187235SMingwei Zhang * We still need to disable IRQs to prevent concurrent tear down 285244187235SMingwei Zhang * of page tables. 285344187235SMingwei Zhang */ 285444187235SMingwei Zhang local_irq_save(flags); 2855db543216SSean Christopherson 285644187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 285744187235SMingwei Zhang if (pgd_none(pgd)) 285844187235SMingwei Zhang goto out; 285944187235SMingwei Zhang 286044187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 286144187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 286244187235SMingwei Zhang goto out; 286344187235SMingwei Zhang 286444187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 286544187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 286644187235SMingwei Zhang goto out; 286744187235SMingwei Zhang 286844187235SMingwei Zhang if (pud_large(pud)) { 286944187235SMingwei Zhang level = PG_LEVEL_1G; 287044187235SMingwei Zhang goto out; 287144187235SMingwei Zhang } 287244187235SMingwei Zhang 287344187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 287444187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 287544187235SMingwei Zhang goto out; 287644187235SMingwei Zhang 287744187235SMingwei Zhang if (pmd_large(pmd)) 287844187235SMingwei Zhang level = PG_LEVEL_2M; 287944187235SMingwei Zhang 288044187235SMingwei Zhang out: 288144187235SMingwei Zhang local_irq_restore(flags); 2882db543216SSean Christopherson return level; 2883db543216SSean Christopherson } 2884db543216SSean Christopherson 28858ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 28868ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 28878ca6f063SBen Gardon kvm_pfn_t pfn, int max_level) 28881b6d9d9eSSean Christopherson { 28891b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 2890ec607a56SPaolo Bonzini int host_level; 28911b6d9d9eSSean Christopherson 28921b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 28931b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 28941b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 28951b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 28961b6d9d9eSSean Christopherson break; 28971b6d9d9eSSean Christopherson } 28981b6d9d9eSSean Christopherson 28991b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 29001b6d9d9eSSean Christopherson return PG_LEVEL_4K; 29011b6d9d9eSSean Christopherson 2902ec607a56SPaolo Bonzini host_level = host_pfn_mapping_level(kvm, gfn, pfn, slot); 2903ec607a56SPaolo Bonzini return min(host_level, max_level); 29041b6d9d9eSSean Christopherson } 29051b6d9d9eSSean Christopherson 290673a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 29070885904dSSean Christopherson { 2908e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 290917eff019SSean Christopherson kvm_pfn_t mask; 29100885904dSSean Christopherson 291173a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 29123cf06612SSean Christopherson 291373a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 291473a3c659SPaolo Bonzini return; 291517eff019SSean Christopherson 291673a3c659SPaolo Bonzini if (is_error_noslot_pfn(fault->pfn) || kvm_is_reserved_pfn(fault->pfn)) 291773a3c659SPaolo Bonzini return; 291817eff019SSean Christopherson 2919e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 292073a3c659SPaolo Bonzini return; 2921293e306eSSean Christopherson 29223cf06612SSean Christopherson /* 29233cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 29243cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 29253cf06612SSean Christopherson */ 292673a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 292773a3c659SPaolo Bonzini fault->gfn, fault->pfn, 292873a3c659SPaolo Bonzini fault->max_level); 292973a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 293073a3c659SPaolo Bonzini return; 29314cd071d1SSean Christopherson 29320885904dSSean Christopherson /* 29334cd071d1SSean Christopherson * mmu_notifier_retry() was successful and mmu_lock is held, so 29344cd071d1SSean Christopherson * the pmd can't be split from under us. 29350885904dSSean Christopherson */ 293673a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 293773a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 293873a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 293973a3c659SPaolo Bonzini fault->pfn &= ~mask; 29400885904dSSean Christopherson } 29410885904dSSean Christopherson 2942536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 2943c50d8ae3SPaolo Bonzini { 2944536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 2945536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 2946c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 2947c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 2948c50d8ae3SPaolo Bonzini /* 2949c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 2950c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 2951c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 2952c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 2953c50d8ae3SPaolo Bonzini * the address. 2954c50d8ae3SPaolo Bonzini */ 2955536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 2956536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 2957536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 2958536f0e6aSPaolo Bonzini fault->goal_level--; 2959c50d8ae3SPaolo Bonzini } 2960c50d8ae3SPaolo Bonzini } 2961c50d8ae3SPaolo Bonzini 296243b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 2963c50d8ae3SPaolo Bonzini { 2964c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 2965c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 296673a3c659SPaolo Bonzini int ret; 296743b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 2968c50d8ae3SPaolo Bonzini 296973a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 29704cd071d1SSean Christopherson 2971f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 297243b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 2973c50d8ae3SPaolo Bonzini /* 2974c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 2975c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 2976c50d8ae3SPaolo Bonzini */ 297773a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 2978536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 2979c50d8ae3SPaolo Bonzini 298043b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 298173a3c659SPaolo Bonzini if (it.level == fault->goal_level) 2982c50d8ae3SPaolo Bonzini break; 2983c50d8ae3SPaolo Bonzini 2984c50d8ae3SPaolo Bonzini drop_large_spte(vcpu, it.sptep); 298503fffc54SSean Christopherson if (is_shadow_present_pte(*it.sptep)) 298603fffc54SSean Christopherson continue; 298703fffc54SSean Christopherson 2988c50d8ae3SPaolo Bonzini sp = kvm_mmu_get_page(vcpu, base_gfn, it.addr, 2989c50d8ae3SPaolo Bonzini it.level - 1, true, ACC_ALL); 2990c50d8ae3SPaolo Bonzini 2991c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 299273a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 299373a3c659SPaolo Bonzini fault->req_level >= it.level) 2994c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 2995c50d8ae3SPaolo Bonzini } 2996c50d8ae3SPaolo Bonzini 2997b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 2998b1a429fbSSean Christopherson return -EFAULT; 2999b1a429fbSSean Christopherson 30008a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3001a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 300212703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 300312703759SSean Christopherson return ret; 300412703759SSean Christopherson 3005c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3006c50d8ae3SPaolo Bonzini ++vcpu->stat.pf_fixed; 3007c50d8ae3SPaolo Bonzini return ret; 3008c50d8ae3SPaolo Bonzini } 3009c50d8ae3SPaolo Bonzini 3010c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 3011c50d8ae3SPaolo Bonzini { 3012c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 3013c50d8ae3SPaolo Bonzini } 3014c50d8ae3SPaolo Bonzini 3015c50d8ae3SPaolo Bonzini static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 3016c50d8ae3SPaolo Bonzini { 3017c50d8ae3SPaolo Bonzini /* 3018c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3019c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3020c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3021c50d8ae3SPaolo Bonzini */ 3022c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3023c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3024c50d8ae3SPaolo Bonzini 3025c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3026c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3027c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3028c50d8ae3SPaolo Bonzini } 3029c50d8ae3SPaolo Bonzini 3030c50d8ae3SPaolo Bonzini return -EFAULT; 3031c50d8ae3SPaolo Bonzini } 3032c50d8ae3SPaolo Bonzini 30333a13f4feSPaolo Bonzini static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 30343a13f4feSPaolo Bonzini unsigned int access, int *ret_val) 3035c50d8ae3SPaolo Bonzini { 3036c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 30373a13f4feSPaolo Bonzini if (unlikely(is_error_pfn(fault->pfn))) { 30383a13f4feSPaolo Bonzini *ret_val = kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); 3039c50d8ae3SPaolo Bonzini return true; 3040c50d8ae3SPaolo Bonzini } 3041c50d8ae3SPaolo Bonzini 3042e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 30433a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 30443a13f4feSPaolo Bonzini 30453a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3046c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 304730ab5901SSean Christopherson /* 304830ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 304930ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 305086931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 305186931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 305286931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 305386931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 305486931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 305586931ff7SSean Christopherson * the hardware's). 305630ab5901SSean Christopherson */ 30578b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 305886931ff7SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) { 305930ab5901SSean Christopherson *ret_val = RET_PF_EMULATE; 306030ab5901SSean Christopherson return true; 306130ab5901SSean Christopherson } 306230ab5901SSean Christopherson } 3063c50d8ae3SPaolo Bonzini 3064c50d8ae3SPaolo Bonzini return false; 3065c50d8ae3SPaolo Bonzini } 3066c50d8ae3SPaolo Bonzini 30673c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3068c50d8ae3SPaolo Bonzini { 3069c50d8ae3SPaolo Bonzini /* 3070c50d8ae3SPaolo Bonzini * Do not fix the mmio spte with invalid generation number which 3071c50d8ae3SPaolo Bonzini * need to be updated by slow page fault path. 3072c50d8ae3SPaolo Bonzini */ 30733c8ad5a6SPaolo Bonzini if (fault->rsvd) 3074c50d8ae3SPaolo Bonzini return false; 3075c50d8ae3SPaolo Bonzini 3076c50d8ae3SPaolo Bonzini /* See if the page fault is due to an NX violation */ 30773c8ad5a6SPaolo Bonzini if (unlikely(fault->exec && fault->present)) 3078c50d8ae3SPaolo Bonzini return false; 3079c50d8ae3SPaolo Bonzini 3080c50d8ae3SPaolo Bonzini /* 3081c50d8ae3SPaolo Bonzini * #PF can be fast if: 3082c50d8ae3SPaolo Bonzini * 1. The shadow page table entry is not present, which could mean that 3083c50d8ae3SPaolo Bonzini * the fault is potentially caused by access tracking (if enabled). 3084c50d8ae3SPaolo Bonzini * 2. The shadow page table entry is present and the fault 3085c50d8ae3SPaolo Bonzini * is caused by write-protect, that means we just need change the W 3086c50d8ae3SPaolo Bonzini * bit of the spte which can be done out of mmu-lock. 3087c50d8ae3SPaolo Bonzini * 3088c50d8ae3SPaolo Bonzini * However, if access tracking is disabled we know that a non-present 3089c50d8ae3SPaolo Bonzini * page must be a genuine page fault where we have to create a new SPTE. 3090c50d8ae3SPaolo Bonzini * So, if access tracking is disabled, we return true only for write 3091c50d8ae3SPaolo Bonzini * accesses to a present page. 3092c50d8ae3SPaolo Bonzini */ 3093c50d8ae3SPaolo Bonzini 30943c8ad5a6SPaolo Bonzini return shadow_acc_track_mask != 0 || (fault->write && fault->present); 3095c50d8ae3SPaolo Bonzini } 3096c50d8ae3SPaolo Bonzini 3097c50d8ae3SPaolo Bonzini /* 3098c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3099c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3100c50d8ae3SPaolo Bonzini */ 3101c50d8ae3SPaolo Bonzini static bool 3102e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3103c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3104c50d8ae3SPaolo Bonzini { 3105c50d8ae3SPaolo Bonzini /* 3106c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3107c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3108c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3109c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3110c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3111c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3112c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3113c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3114c50d8ae3SPaolo Bonzini * 3115c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3116c50d8ae3SPaolo Bonzini */ 3117c50d8ae3SPaolo Bonzini if (cmpxchg64(sptep, old_spte, new_spte) != old_spte) 3118c50d8ae3SPaolo Bonzini return false; 3119c50d8ae3SPaolo Bonzini 3120e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3121e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3122c50d8ae3SPaolo Bonzini 3123c50d8ae3SPaolo Bonzini return true; 3124c50d8ae3SPaolo Bonzini } 3125c50d8ae3SPaolo Bonzini 31263c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3127c50d8ae3SPaolo Bonzini { 31283c8ad5a6SPaolo Bonzini if (fault->exec) 3129c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3130c50d8ae3SPaolo Bonzini 31313c8ad5a6SPaolo Bonzini if (fault->write) 3132c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3133c50d8ae3SPaolo Bonzini 3134c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3135c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3136c50d8ae3SPaolo Bonzini } 3137c50d8ae3SPaolo Bonzini 3138c50d8ae3SPaolo Bonzini /* 31396e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 31406e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 31416e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 31426e8eb206SDavid Matlack * 31436e8eb206SDavid Matlack * Contract: 31446e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 31456e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 31466e8eb206SDavid Matlack */ 31476e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 31486e8eb206SDavid Matlack { 31496e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 31506e8eb206SDavid Matlack u64 old_spte; 31516e8eb206SDavid Matlack u64 *sptep = NULL; 31526e8eb206SDavid Matlack 31536e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 31546e8eb206SDavid Matlack sptep = iterator.sptep; 31556e8eb206SDavid Matlack *spte = old_spte; 31566e8eb206SDavid Matlack } 31576e8eb206SDavid Matlack 31586e8eb206SDavid Matlack return sptep; 31596e8eb206SDavid Matlack } 31606e8eb206SDavid Matlack 31616e8eb206SDavid Matlack /* 3162c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3163c50d8ae3SPaolo Bonzini */ 31643c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3165c50d8ae3SPaolo Bonzini { 3166c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3167c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3168c50d8ae3SPaolo Bonzini u64 spte = 0ull; 31696e8eb206SDavid Matlack u64 *sptep = NULL; 3170c50d8ae3SPaolo Bonzini uint retry_count = 0; 3171c50d8ae3SPaolo Bonzini 31723c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3173c4371c2aSSean Christopherson return ret; 3174c50d8ae3SPaolo Bonzini 3175c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3176c50d8ae3SPaolo Bonzini 3177c50d8ae3SPaolo Bonzini do { 3178c50d8ae3SPaolo Bonzini u64 new_spte; 3179c50d8ae3SPaolo Bonzini 31806e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 31813c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 31826e8eb206SDavid Matlack else 31833c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3184c50d8ae3SPaolo Bonzini 3185ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3186ec89e643SSean Christopherson break; 3187ec89e643SSean Christopherson 31886e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3189c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3190c50d8ae3SPaolo Bonzini break; 3191c50d8ae3SPaolo Bonzini 3192c50d8ae3SPaolo Bonzini /* 3193c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3194c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3195c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3196c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3197c50d8ae3SPaolo Bonzini * current CPU took the fault. 3198c50d8ae3SPaolo Bonzini * 3199c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3200c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3201c50d8ae3SPaolo Bonzini */ 32023c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3203c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3204c50d8ae3SPaolo Bonzini break; 3205c50d8ae3SPaolo Bonzini } 3206c50d8ae3SPaolo Bonzini 3207c50d8ae3SPaolo Bonzini new_spte = spte; 3208c50d8ae3SPaolo Bonzini 3209c50d8ae3SPaolo Bonzini if (is_access_track_spte(spte)) 3210c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3211c50d8ae3SPaolo Bonzini 3212c50d8ae3SPaolo Bonzini /* 3213c50d8ae3SPaolo Bonzini * Currently, to simplify the code, write-protection can 3214c50d8ae3SPaolo Bonzini * be removed in the fast path only if the SPTE was 3215c50d8ae3SPaolo Bonzini * write-protected for dirty-logging or access tracking. 3216c50d8ae3SPaolo Bonzini */ 32173c8ad5a6SPaolo Bonzini if (fault->write && 3218e6302698SMiaohe Lin spte_can_locklessly_be_made_writable(spte)) { 3219c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3220c50d8ae3SPaolo Bonzini 3221c50d8ae3SPaolo Bonzini /* 322210c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 322310c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 322410c30de0SJunaid Shahid * first page into the dirty-bitmap in 3225c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3226c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3227c50d8ae3SPaolo Bonzini * 3228c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3229c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3230c50d8ae3SPaolo Bonzini */ 323110c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 323210c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3233c50d8ae3SPaolo Bonzini break; 3234c50d8ae3SPaolo Bonzini } 3235c50d8ae3SPaolo Bonzini 3236c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3237c50d8ae3SPaolo Bonzini if (new_spte == spte || 32383c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3239c50d8ae3SPaolo Bonzini break; 3240c50d8ae3SPaolo Bonzini 3241c50d8ae3SPaolo Bonzini /* 3242c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3243c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 32443ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3245c50d8ae3SPaolo Bonzini */ 3246e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3247c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3248c50d8ae3SPaolo Bonzini break; 3249c4371c2aSSean Christopherson } 3250c50d8ae3SPaolo Bonzini 3251c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3252c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3253c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3254c50d8ae3SPaolo Bonzini break; 3255c50d8ae3SPaolo Bonzini } 3256c50d8ae3SPaolo Bonzini 3257c50d8ae3SPaolo Bonzini } while (true); 3258c50d8ae3SPaolo Bonzini 3259f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3260c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3261c50d8ae3SPaolo Bonzini 3262c4371c2aSSean Christopherson return ret; 3263c50d8ae3SPaolo Bonzini } 3264c50d8ae3SPaolo Bonzini 3265c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3266c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3267c50d8ae3SPaolo Bonzini { 3268c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3269c50d8ae3SPaolo Bonzini 3270c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3271c50d8ae3SPaolo Bonzini return; 3272c50d8ae3SPaolo Bonzini 3273e47c4aeeSSean Christopherson sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK); 32749191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 32759191b8f0SPaolo Bonzini return; 327602c00b3aSBen Gardon 3277897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 32786103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 327976eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3280c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3281c50d8ae3SPaolo Bonzini 3282c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3283c50d8ae3SPaolo Bonzini } 3284c50d8ae3SPaolo Bonzini 3285c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 32860c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3287c50d8ae3SPaolo Bonzini ulong roots_to_free) 3288c50d8ae3SPaolo Bonzini { 3289c50d8ae3SPaolo Bonzini int i; 3290c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3291594bef79SPaolo Bonzini bool free_active_root; 3292c50d8ae3SPaolo Bonzini 3293c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3294c50d8ae3SPaolo Bonzini 3295c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3296594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3297594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3298594bef79SPaolo Bonzini 3299594bef79SPaolo Bonzini if (!free_active_root) { 3300c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3301c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3302c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3303c50d8ae3SPaolo Bonzini break; 3304c50d8ae3SPaolo Bonzini 3305c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3306c50d8ae3SPaolo Bonzini return; 3307c50d8ae3SPaolo Bonzini } 3308c50d8ae3SPaolo Bonzini 3309531810caSBen Gardon write_lock(&kvm->mmu_lock); 3310c50d8ae3SPaolo Bonzini 3311c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3312c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 33134d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3314c50d8ae3SPaolo Bonzini &invalid_list); 3315c50d8ae3SPaolo Bonzini 3316c50d8ae3SPaolo Bonzini if (free_active_root) { 3317594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3318b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 331904d45551SSean Christopherson } else if (mmu->pae_root) { 3320c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3321c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3322c834e5e4SSean Christopherson continue; 3323c834e5e4SSean Christopherson 3324c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3325c50d8ae3SPaolo Bonzini &invalid_list); 3326c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3327c50d8ae3SPaolo Bonzini } 3328c50d8ae3SPaolo Bonzini } 3329b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3330b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3331c50d8ae3SPaolo Bonzini } 3332c50d8ae3SPaolo Bonzini 33334d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3334531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3335c50d8ae3SPaolo Bonzini } 3336c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3337c50d8ae3SPaolo Bonzini 33380c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 333925b62c62SSean Christopherson { 334025b62c62SSean Christopherson unsigned long roots_to_free = 0; 334125b62c62SSean Christopherson hpa_t root_hpa; 334225b62c62SSean Christopherson int i; 334325b62c62SSean Christopherson 334425b62c62SSean Christopherson /* 334525b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 334625b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 334725b62c62SSean Christopherson */ 33487a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 334925b62c62SSean Christopherson 335025b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 335125b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 335225b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 335325b62c62SSean Christopherson continue; 335425b62c62SSean Christopherson 335525b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 335625b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 335725b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 335825b62c62SSean Christopherson } 335925b62c62SSean Christopherson 33600c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 336125b62c62SSean Christopherson } 336225b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 336325b62c62SSean Christopherson 336425b62c62SSean Christopherson 3365c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3366c50d8ae3SPaolo Bonzini { 3367c50d8ae3SPaolo Bonzini int ret = 0; 3368c50d8ae3SPaolo Bonzini 3369995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3370c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3371c50d8ae3SPaolo Bonzini ret = 1; 3372c50d8ae3SPaolo Bonzini } 3373c50d8ae3SPaolo Bonzini 3374c50d8ae3SPaolo Bonzini return ret; 3375c50d8ae3SPaolo Bonzini } 3376c50d8ae3SPaolo Bonzini 33778123f265SSean Christopherson static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva, 33788123f265SSean Christopherson u8 level, bool direct) 3379c50d8ae3SPaolo Bonzini { 3380c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 33818123f265SSean Christopherson 33828123f265SSean Christopherson sp = kvm_mmu_get_page(vcpu, gfn, gva, level, direct, ACC_ALL); 33838123f265SSean Christopherson ++sp->root_count; 33848123f265SSean Christopherson 33858123f265SSean Christopherson return __pa(sp->spt); 33868123f265SSean Christopherson } 33878123f265SSean Christopherson 33888123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 33898123f265SSean Christopherson { 3390b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3391a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 33928123f265SSean Christopherson hpa_t root; 3393c50d8ae3SPaolo Bonzini unsigned i; 33944a38162eSPaolo Bonzini int r; 33954a38162eSPaolo Bonzini 33964a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 33974a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 33984a38162eSPaolo Bonzini if (r < 0) 33994a38162eSPaolo Bonzini goto out_unlock; 3400c50d8ae3SPaolo Bonzini 3401897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 340202c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3403b9e5603cSPaolo Bonzini mmu->root.hpa = root; 340402c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 34056e6ec584SSean Christopherson root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true); 3406b9e5603cSPaolo Bonzini mmu->root.hpa = root; 34078123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 34084a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 34094a38162eSPaolo Bonzini r = -EIO; 34104a38162eSPaolo Bonzini goto out_unlock; 34114a38162eSPaolo Bonzini } 341273ad1606SSean Christopherson 3413c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3414c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3415c50d8ae3SPaolo Bonzini 34168123f265SSean Christopherson root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 34178123f265SSean Christopherson i << 30, PT32_ROOT_LEVEL, true); 341817e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 341917e368d9SSean Christopherson shadow_me_mask; 3420c50d8ae3SPaolo Bonzini } 3421b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 342273ad1606SSean Christopherson } else { 342373ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 34244a38162eSPaolo Bonzini r = -EIO; 34254a38162eSPaolo Bonzini goto out_unlock; 342673ad1606SSean Christopherson } 34273651c7fcSSean Christopherson 3428b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3429b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 34304a38162eSPaolo Bonzini out_unlock: 34314a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 34324a38162eSPaolo Bonzini return r; 3433c50d8ae3SPaolo Bonzini } 3434c50d8ae3SPaolo Bonzini 34351e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 34361e76a3ceSDavid Stevens { 34371e76a3ceSDavid Stevens struct kvm_memslots *slots; 34381e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3439a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 34401e76a3ceSDavid Stevens 34411e76a3ceSDavid Stevens /* 34421e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 34431e76a3ceSDavid Stevens * taking the lock. 34441e76a3ceSDavid Stevens */ 34451e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34461e76a3ceSDavid Stevens return 0; 34471e76a3ceSDavid Stevens 34481e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 34491e76a3ceSDavid Stevens 34501e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 34511e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34521e76a3ceSDavid Stevens goto out_unlock; 34531e76a3ceSDavid Stevens 34541e76a3ceSDavid Stevens /* 34551e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 34561e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 34571e76a3ceSDavid Stevens */ 34581e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 34591e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 34601e76a3ceSDavid Stevens goto out_success; 34611e76a3ceSDavid Stevens 34621e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 34631e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3464a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 34651e76a3ceSDavid Stevens /* 34661e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 34671e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 34681e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 34691e76a3ceSDavid Stevens * failure to avoid having to track which allocations 34701e76a3ceSDavid Stevens * were made now versus when the memslot was created. 34711e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 34721e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 34731e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 34741e76a3ceSDavid Stevens */ 34751e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 34761e76a3ceSDavid Stevens if (r) 34771e76a3ceSDavid Stevens goto out_unlock; 34781e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 34791e76a3ceSDavid Stevens if (r) 34801e76a3ceSDavid Stevens goto out_unlock; 34811e76a3ceSDavid Stevens } 34821e76a3ceSDavid Stevens } 34831e76a3ceSDavid Stevens 34841e76a3ceSDavid Stevens /* 34851e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 34861e76a3ceSDavid Stevens * all the related pointers are set. 34871e76a3ceSDavid Stevens */ 34881e76a3ceSDavid Stevens out_success: 34891e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 34901e76a3ceSDavid Stevens 34911e76a3ceSDavid Stevens out_unlock: 34921e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 34931e76a3ceSDavid Stevens return r; 34941e76a3ceSDavid Stevens } 34951e76a3ceSDavid Stevens 3496c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3497c50d8ae3SPaolo Bonzini { 3498b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 34996e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3500be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 35018123f265SSean Christopherson hpa_t root; 35024a38162eSPaolo Bonzini unsigned i; 35034a38162eSPaolo Bonzini int r; 3504c50d8ae3SPaolo Bonzini 3505b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3506be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3507c50d8ae3SPaolo Bonzini 3508c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3509c50d8ae3SPaolo Bonzini return 1; 3510c50d8ae3SPaolo Bonzini 3511c50d8ae3SPaolo Bonzini /* 35124a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 35134a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 35144a38162eSPaolo Bonzini */ 35154d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 35166e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 35176e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 35186e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 35196e0918aeSSean Christopherson continue; 35206e0918aeSSean Christopherson 35216e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 35226e0918aeSSean Christopherson return 1; 35236e0918aeSSean Christopherson } 35246e0918aeSSean Christopherson } 35256e0918aeSSean Christopherson 35261e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3527d501f747SBen Gardon if (r) 3528d501f747SBen Gardon return r; 3529d501f747SBen Gardon 35304a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35314a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35324a38162eSPaolo Bonzini if (r < 0) 35334a38162eSPaolo Bonzini goto out_unlock; 35344a38162eSPaolo Bonzini 3535c50d8ae3SPaolo Bonzini /* 3536c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3537c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3538c50d8ae3SPaolo Bonzini */ 35394d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 35408123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 3541a972e29cSPaolo Bonzini mmu->root_role.level, false); 3542b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3543be01e8e2SSean Christopherson goto set_root_pgd; 3544c50d8ae3SPaolo Bonzini } 3545c50d8ae3SPaolo Bonzini 35464a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35474a38162eSPaolo Bonzini r = -EIO; 35484a38162eSPaolo Bonzini goto out_unlock; 35494a38162eSPaolo Bonzini } 355073ad1606SSean Christopherson 3551c50d8ae3SPaolo Bonzini /* 3552c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3553c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3554c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3555c50d8ae3SPaolo Bonzini */ 355617e368d9SSean Christopherson pm_mask = PT_PRESENT_MASK | shadow_me_mask; 3557a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3558c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3559c50d8ae3SPaolo Bonzini 356003ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 35614a38162eSPaolo Bonzini r = -EIO; 35624a38162eSPaolo Bonzini goto out_unlock; 35634a38162eSPaolo Bonzini } 356403ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3565cb0f722aSWei Huang 3566a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3567cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3568cb0f722aSWei Huang r = -EIO; 3569cb0f722aSWei Huang goto out_unlock; 3570cb0f722aSWei Huang } 3571cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3572cb0f722aSWei Huang } 357304d45551SSean Christopherson } 357404d45551SSean Christopherson 3575c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3576c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 35776e6ec584SSean Christopherson 35784d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 35796e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3580c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3581c50d8ae3SPaolo Bonzini continue; 3582c50d8ae3SPaolo Bonzini } 35836e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3584c50d8ae3SPaolo Bonzini } 3585c50d8ae3SPaolo Bonzini 35868123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, i << 30, 35878123f265SSean Christopherson PT32_ROOT_LEVEL, false); 3588b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3589c50d8ae3SPaolo Bonzini } 3590c50d8ae3SPaolo Bonzini 3591a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3592b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3593a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3594b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3595ba0a194fSSean Christopherson else 3596b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3597c50d8ae3SPaolo Bonzini 3598be01e8e2SSean Christopherson set_root_pgd: 3599b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 36004a38162eSPaolo Bonzini out_unlock: 36014a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3602c50d8ae3SPaolo Bonzini 3603c6c937d6SLike Xu return r; 3604c50d8ae3SPaolo Bonzini } 3605c50d8ae3SPaolo Bonzini 3606748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3607c50d8ae3SPaolo Bonzini { 3608748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3609a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3610cb0f722aSWei Huang u64 *pml5_root = NULL; 3611cb0f722aSWei Huang u64 *pml4_root = NULL; 3612cb0f722aSWei Huang u64 *pae_root; 3613748e52b9SSean Christopherson 3614748e52b9SSean Christopherson /* 3615748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3616748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3617748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3618748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3619748e52b9SSean Christopherson */ 3620347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3621347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3622a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3623748e52b9SSean Christopherson return 0; 3624748e52b9SSean Christopherson 3625a717a780SSean Christopherson /* 3626a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3627a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3628a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3629a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3630a717a780SSean Christopherson * prior MMU would also have required pml5. 3631a717a780SSean Christopherson */ 3632a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3633748e52b9SSean Christopherson return 0; 3634748e52b9SSean Christopherson 3635748e52b9SSean Christopherson /* 3636748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3637748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3638748e52b9SSean Christopherson */ 3639cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3640a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3641748e52b9SSean Christopherson return -EIO; 3642748e52b9SSean Christopherson 36434a98623dSSean Christopherson /* 36444a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 36454a98623dSSean Christopherson * doesn't need to be decrypted. 36464a98623dSSean Christopherson */ 3647748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3648748e52b9SSean Christopherson if (!pae_root) 3649748e52b9SSean Christopherson return -ENOMEM; 3650748e52b9SSean Christopherson 3651cb0f722aSWei Huang #ifdef CONFIG_X86_64 365203ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3653cb0f722aSWei Huang if (!pml4_root) 3654cb0f722aSWei Huang goto err_pml4; 3655cb0f722aSWei Huang 3656a717a780SSean Christopherson if (need_pml5) { 3657cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3658cb0f722aSWei Huang if (!pml5_root) 3659cb0f722aSWei Huang goto err_pml5; 3660748e52b9SSean Christopherson } 3661cb0f722aSWei Huang #endif 3662748e52b9SSean Christopherson 3663748e52b9SSean Christopherson mmu->pae_root = pae_root; 366403ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3665cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3666748e52b9SSean Christopherson 3667748e52b9SSean Christopherson return 0; 3668cb0f722aSWei Huang 3669cb0f722aSWei Huang #ifdef CONFIG_X86_64 3670cb0f722aSWei Huang err_pml5: 3671cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3672cb0f722aSWei Huang err_pml4: 3673cb0f722aSWei Huang free_page((unsigned long)pae_root); 3674cb0f722aSWei Huang return -ENOMEM; 3675cb0f722aSWei Huang #endif 3676c50d8ae3SPaolo Bonzini } 3677c50d8ae3SPaolo Bonzini 3678264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3679264d3dc1SLai Jiangshan { 3680264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3681264d3dc1SLai Jiangshan 368261b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 368361b05a9fSLai Jiangshan return false; 368461b05a9fSLai Jiangshan 3685264d3dc1SLai Jiangshan /* 3686264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3687264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3688264d3dc1SLai Jiangshan * 3689264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3690264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3691264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3692264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3693264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3694264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3695264d3dc1SLai Jiangshan * requirement isn't satisfied. 3696264d3dc1SLai Jiangshan */ 3697264d3dc1SLai Jiangshan smp_rmb(); 3698264d3dc1SLai Jiangshan sp = to_shadow_page(root); 36995d6a3221SSean Christopherson 37005d6a3221SSean Christopherson /* 37015d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 37025d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 37035d6a3221SSean Christopherson */ 37045d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 37055d6a3221SSean Christopherson return false; 37065d6a3221SSean Christopherson 3707264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3708264d3dc1SLai Jiangshan return true; 3709264d3dc1SLai Jiangshan 3710264d3dc1SLai Jiangshan return false; 3711264d3dc1SLai Jiangshan } 3712264d3dc1SLai Jiangshan 3713c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3714c50d8ae3SPaolo Bonzini { 3715c50d8ae3SPaolo Bonzini int i; 3716c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3717c50d8ae3SPaolo Bonzini 3718347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3719c50d8ae3SPaolo Bonzini return; 3720c50d8ae3SPaolo Bonzini 3721b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3722c50d8ae3SPaolo Bonzini return; 3723c50d8ae3SPaolo Bonzini 3724c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3725c50d8ae3SPaolo Bonzini 37264d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3727b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3728e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3729c50d8ae3SPaolo Bonzini 3730264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3731c50d8ae3SPaolo Bonzini return; 3732c50d8ae3SPaolo Bonzini 3733531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 373465855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3735531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3736c50d8ae3SPaolo Bonzini return; 3737c50d8ae3SPaolo Bonzini } 3738c50d8ae3SPaolo Bonzini 3739531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3740c50d8ae3SPaolo Bonzini 3741c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3742c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3743c50d8ae3SPaolo Bonzini 3744c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 3745c50d8ae3SPaolo Bonzini root &= PT64_BASE_ADDR_MASK; 3746e47c4aeeSSean Christopherson sp = to_shadow_page(root); 374765855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3748c50d8ae3SPaolo Bonzini } 3749c50d8ae3SPaolo Bonzini } 3750c50d8ae3SPaolo Bonzini 3751531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3752c50d8ae3SPaolo Bonzini } 3753c50d8ae3SPaolo Bonzini 375461b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 375561b05a9fSLai Jiangshan { 375661b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 375761b05a9fSLai Jiangshan int i; 375861b05a9fSLai Jiangshan 375961b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 376061b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 376161b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 376261b05a9fSLai Jiangshan 376361b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 37640c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 376561b05a9fSLai Jiangshan } 376661b05a9fSLai Jiangshan 37671f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 37685b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3769c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3770c50d8ae3SPaolo Bonzini { 3771c50d8ae3SPaolo Bonzini if (exception) 3772c50d8ae3SPaolo Bonzini exception->error_code = 0; 3773c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3774c50d8ae3SPaolo Bonzini } 3775c50d8ae3SPaolo Bonzini 3776c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3777c50d8ae3SPaolo Bonzini { 3778c50d8ae3SPaolo Bonzini /* 3779c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3780c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3781c50d8ae3SPaolo Bonzini */ 3782c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3783c50d8ae3SPaolo Bonzini return false; 3784c50d8ae3SPaolo Bonzini 3785c50d8ae3SPaolo Bonzini if (direct) 3786c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3787c50d8ae3SPaolo Bonzini 3788c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3789c50d8ae3SPaolo Bonzini } 3790c50d8ae3SPaolo Bonzini 379195fb5b02SBen Gardon /* 379295fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 379395fb5b02SBen Gardon * That SPTE may be non-present. 3794c5c8c7c5SDavid Matlack * 3795c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 379695fb5b02SBen Gardon */ 379739b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3798c50d8ae3SPaolo Bonzini { 3799c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 38002aa07893SSean Christopherson int leaf = -1; 380195fb5b02SBen Gardon u64 spte; 3802c50d8ae3SPaolo Bonzini 380339b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 380439b4d43eSSean Christopherson *root_level = iterator.level; 3805c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3806c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 380795fb5b02SBen Gardon leaf = iterator.level; 3808c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3809c50d8ae3SPaolo Bonzini 3810dde81f94SSean Christopherson sptes[leaf] = spte; 381195fb5b02SBen Gardon } 381295fb5b02SBen Gardon 381395fb5b02SBen Gardon return leaf; 381495fb5b02SBen Gardon } 381595fb5b02SBen Gardon 38169aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 381795fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 381895fb5b02SBen Gardon { 3819dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 382095fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 382139b4d43eSSean Christopherson int root, leaf, level; 382295fb5b02SBen Gardon bool reserved = false; 382395fb5b02SBen Gardon 3824c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3825c5c8c7c5SDavid Matlack 382663c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 382739b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 382895fb5b02SBen Gardon else 382939b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 383095fb5b02SBen Gardon 3831c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 3832c5c8c7c5SDavid Matlack 38332aa07893SSean Christopherson if (unlikely(leaf < 0)) { 38342aa07893SSean Christopherson *sptep = 0ull; 38352aa07893SSean Christopherson return reserved; 38362aa07893SSean Christopherson } 38372aa07893SSean Christopherson 38389aa41879SSean Christopherson *sptep = sptes[leaf]; 38399aa41879SSean Christopherson 38409aa41879SSean Christopherson /* 38419aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 38429aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 38439aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 38449aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 38459aa41879SSean Christopherson */ 38469aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 38479aa41879SSean Christopherson leaf++; 384895fb5b02SBen Gardon 384995fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 385095fb5b02SBen Gardon 38519aa41879SSean Christopherson for (level = root; level >= leaf; level--) 3852961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 3853c50d8ae3SPaolo Bonzini 3854c50d8ae3SPaolo Bonzini if (reserved) { 3855bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 3856c50d8ae3SPaolo Bonzini __func__, addr); 385795fb5b02SBen Gardon for (level = root; level >= leaf; level--) 3858bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 3859bb4cdf3aSSean Christopherson sptes[level], level, 3860961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 3861c50d8ae3SPaolo Bonzini } 3862ddce6208SSean Christopherson 3863c50d8ae3SPaolo Bonzini return reserved; 3864c50d8ae3SPaolo Bonzini } 3865c50d8ae3SPaolo Bonzini 3866c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3867c50d8ae3SPaolo Bonzini { 3868c50d8ae3SPaolo Bonzini u64 spte; 3869c50d8ae3SPaolo Bonzini bool reserved; 3870c50d8ae3SPaolo Bonzini 3871c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 3872c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3873c50d8ae3SPaolo Bonzini 387495fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 3875c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 3876c50d8ae3SPaolo Bonzini return -EINVAL; 3877c50d8ae3SPaolo Bonzini 3878c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 3879c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 38800a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 3881c50d8ae3SPaolo Bonzini 3882c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 3883c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 3884c50d8ae3SPaolo Bonzini 3885c50d8ae3SPaolo Bonzini if (direct) 3886c50d8ae3SPaolo Bonzini addr = 0; 3887c50d8ae3SPaolo Bonzini 3888c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 3889c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 3890c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3891c50d8ae3SPaolo Bonzini } 3892c50d8ae3SPaolo Bonzini 3893c50d8ae3SPaolo Bonzini /* 3894c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 3895c50d8ae3SPaolo Bonzini * the address. 3896c50d8ae3SPaolo Bonzini */ 3897c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3898c50d8ae3SPaolo Bonzini } 3899c50d8ae3SPaolo Bonzini 3900c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 3901b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 3902c50d8ae3SPaolo Bonzini { 3903b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 3904c50d8ae3SPaolo Bonzini return false; 3905c50d8ae3SPaolo Bonzini 3906b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 3907c50d8ae3SPaolo Bonzini return false; 3908c50d8ae3SPaolo Bonzini 3909c50d8ae3SPaolo Bonzini /* 3910c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 3911c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 3912c50d8ae3SPaolo Bonzini */ 39139d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 3914c50d8ae3SPaolo Bonzini return true; 3915c50d8ae3SPaolo Bonzini 3916c50d8ae3SPaolo Bonzini return false; 3917c50d8ae3SPaolo Bonzini } 3918c50d8ae3SPaolo Bonzini 3919c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 3920c50d8ae3SPaolo Bonzini { 3921c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 3922c50d8ae3SPaolo Bonzini u64 spte; 3923c50d8ae3SPaolo Bonzini 3924c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 39253e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 3926c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 3927c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3928c50d8ae3SPaolo Bonzini } 3929c50d8ae3SPaolo Bonzini 39306f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 39316f3c1fc5SLiang Zhang { 39326f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 39336f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 39346f3c1fc5SLiang Zhang 39356f3c1fc5SLiang Zhang if (id << 12 == 0) 39366f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 39376f3c1fc5SLiang Zhang 39386f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 39396f3c1fc5SLiang Zhang } 39406f3c1fc5SLiang Zhang 3941e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 39429f1a8526SSean Christopherson gfn_t gfn) 3943c50d8ae3SPaolo Bonzini { 3944c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 3945c50d8ae3SPaolo Bonzini 39466f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 3947c50d8ae3SPaolo Bonzini arch.gfn = gfn; 3948347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 3949d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 3950c50d8ae3SPaolo Bonzini 39519f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 39529f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 3953c50d8ae3SPaolo Bonzini } 3954c50d8ae3SPaolo Bonzini 39553647cd04SPaolo Bonzini static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, int *r) 3956c50d8ae3SPaolo Bonzini { 3957e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 3958c50d8ae3SPaolo Bonzini bool async; 3959c50d8ae3SPaolo Bonzini 3960e0c37868SSean Christopherson /* 3961e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 3962e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 3963e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 3964e0c37868SSean Christopherson */ 3965e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 39668f32d5e5SMaxim Levitsky goto out_retry; 3967e0c37868SSean Christopherson 39689cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 3969c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 39709cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 3971e710c5f6SDavid Matlack fault->slot = NULL; 39723647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 39733647cd04SPaolo Bonzini fault->map_writable = false; 3974c50d8ae3SPaolo Bonzini return false; 3975c50d8ae3SPaolo Bonzini } 39769cc13d60SMaxim Levitsky /* 39779cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 39789cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 39799cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 39809cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 39819cc13d60SMaxim Levitsky */ 39829cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 39839cc13d60SMaxim Levitsky !kvm_apicv_activated(vcpu->kvm)) { 39849cc13d60SMaxim Levitsky *r = RET_PF_EMULATE; 39859cc13d60SMaxim Levitsky return true; 39869cc13d60SMaxim Levitsky } 39879cc13d60SMaxim Levitsky } 3988c50d8ae3SPaolo Bonzini 3989c50d8ae3SPaolo Bonzini async = false; 39903647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, 39913647cd04SPaolo Bonzini fault->write, &fault->map_writable, 39923647cd04SPaolo Bonzini &fault->hva); 3993c50d8ae3SPaolo Bonzini if (!async) 3994c50d8ae3SPaolo Bonzini return false; /* *pfn has correct page already */ 3995c50d8ae3SPaolo Bonzini 39962839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 39973647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 39983647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 39993647cd04SPaolo Bonzini trace_kvm_async_pf_doublefault(fault->addr, fault->gfn); 4000c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 40018f32d5e5SMaxim Levitsky goto out_retry; 40023647cd04SPaolo Bonzini } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) 40038f32d5e5SMaxim Levitsky goto out_retry; 4004c50d8ae3SPaolo Bonzini } 4005c50d8ae3SPaolo Bonzini 40063647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, 40073647cd04SPaolo Bonzini fault->write, &fault->map_writable, 40083647cd04SPaolo Bonzini &fault->hva); 4009a7cc099fSAndrei Vagin return false; 40108f32d5e5SMaxim Levitsky 40118f32d5e5SMaxim Levitsky out_retry: 40128f32d5e5SMaxim Levitsky *r = RET_PF_RETRY; 40138f32d5e5SMaxim Levitsky return true; 4014c50d8ae3SPaolo Bonzini } 4015c50d8ae3SPaolo Bonzini 4016a955cad8SSean Christopherson /* 4017a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4018a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4019a955cad8SSean Christopherson */ 4020a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4021a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 4022a955cad8SSean Christopherson { 4023b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 402418c841e1SSean Christopherson 402518c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 402618c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 402718c841e1SSean Christopherson return true; 402818c841e1SSean Christopherson 402918c841e1SSean Christopherson /* 403018c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 403118c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 403218c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 403318c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 403418c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 403518c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 403618c841e1SSean Christopherson */ 4037527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4038a955cad8SSean Christopherson return true; 4039a955cad8SSean Christopherson 4040a955cad8SSean Christopherson return fault->slot && 4041a955cad8SSean Christopherson mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4042a955cad8SSean Christopherson } 4043a955cad8SSean Christopherson 40444326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4045c50d8ae3SPaolo Bonzini { 404663c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4047c50d8ae3SPaolo Bonzini 40480f90e1c1SSean Christopherson unsigned long mmu_seq; 404983f06fa7SSean Christopherson int r; 4050c50d8ae3SPaolo Bonzini 40513c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4052e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4053e710c5f6SDavid Matlack 4054b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4055c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4056c50d8ae3SPaolo Bonzini 40573c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4058c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4059c4371c2aSSean Christopherson return r; 406083291445SSean Christopherson 4061378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4062c50d8ae3SPaolo Bonzini if (r) 4063c50d8ae3SPaolo Bonzini return r; 4064c50d8ae3SPaolo Bonzini 4065367fd790SSean Christopherson mmu_seq = vcpu->kvm->mmu_notifier_seq; 4066367fd790SSean Christopherson smp_rmb(); 4067367fd790SSean Christopherson 40683647cd04SPaolo Bonzini if (kvm_faultin_pfn(vcpu, fault, &r)) 40698f32d5e5SMaxim Levitsky return r; 4070367fd790SSean Christopherson 40713a13f4feSPaolo Bonzini if (handle_abnormal_pfn(vcpu, fault, ACC_ALL, &r)) 4072367fd790SSean Christopherson return r; 4073367fd790SSean Christopherson 4074367fd790SSean Christopherson r = RET_PF_RETRY; 4075a2855afcSBen Gardon 40760b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4077a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4078a2855afcSBen Gardon else 4079531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4080a2855afcSBen Gardon 4081a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4082367fd790SSean Christopherson goto out_unlock; 4083a955cad8SSean Christopherson 40847bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 40857bd7ded6SSean Christopherson if (r) 4086367fd790SSean Christopherson goto out_unlock; 4087bb18842eSBen Gardon 40880b873fd7SDavid Matlack if (is_tdp_mmu_fault) 40892f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4090bb18842eSBen Gardon else 409143b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 40920f90e1c1SSean Christopherson 4093367fd790SSean Christopherson out_unlock: 40940b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4095a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4096a2855afcSBen Gardon else 4097531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 40983647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4099367fd790SSean Christopherson return r; 4100c50d8ae3SPaolo Bonzini } 4101c50d8ae3SPaolo Bonzini 4102c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4103c501040aSPaolo Bonzini struct kvm_page_fault *fault) 41040f90e1c1SSean Christopherson { 41054326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 41060f90e1c1SSean Christopherson 41070f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 41084326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 41094326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 41100f90e1c1SSean Christopherson } 41110f90e1c1SSean Christopherson 4112c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4113c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4114c50d8ae3SPaolo Bonzini { 4115c50d8ae3SPaolo Bonzini int r = 1; 41169ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4117c50d8ae3SPaolo Bonzini 4118736c291cSSean Christopherson #ifndef CONFIG_X86_64 4119736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4120736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4121736c291cSSean Christopherson return -EFAULT; 4122736c291cSSean Christopherson #endif 4123736c291cSSean Christopherson 4124c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 41259ce372b3SVitaly Kuznetsov if (!flags) { 4126c50d8ae3SPaolo Bonzini trace_kvm_page_fault(fault_address, error_code); 4127c50d8ae3SPaolo Bonzini 4128c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4129c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4130c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4131c50d8ae3SPaolo Bonzini insn_len); 41329ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 413368fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4134c50d8ae3SPaolo Bonzini local_irq_disable(); 41356bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4136c50d8ae3SPaolo Bonzini local_irq_enable(); 41379ce372b3SVitaly Kuznetsov } else { 41389ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4139c50d8ae3SPaolo Bonzini } 41409ce372b3SVitaly Kuznetsov 4141c50d8ae3SPaolo Bonzini return r; 4142c50d8ae3SPaolo Bonzini } 4143c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4144c50d8ae3SPaolo Bonzini 4145c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4146c50d8ae3SPaolo Bonzini { 41474326e57eSPaolo Bonzini while (fault->max_level > PG_LEVEL_4K) { 41484326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 41494326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4150c50d8ae3SPaolo Bonzini 4151cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4152cb9b88c6SSean Christopherson break; 41534326e57eSPaolo Bonzini 41544326e57eSPaolo Bonzini --fault->max_level; 4155c50d8ae3SPaolo Bonzini } 4156c50d8ae3SPaolo Bonzini 41574326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4158c50d8ae3SPaolo Bonzini } 4159c50d8ae3SPaolo Bonzini 416084a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4161c50d8ae3SPaolo Bonzini { 4162c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4163c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4164c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 41655efac074SPaolo Bonzini context->invlpg = NULL; 4166c50d8ae3SPaolo Bonzini } 4167c50d8ae3SPaolo Bonzini 4168be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 41690be44352SSean Christopherson union kvm_mmu_page_role role) 41700be44352SSean Christopherson { 4171be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 41725499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4173e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 41740be44352SSean Christopherson } 41750be44352SSean Christopherson 4176c50d8ae3SPaolo Bonzini /* 41775499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 41785499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 41795499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 41805499ea73SPaolo Bonzini * true is returned. 41815499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 41825499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4183c50d8ae3SPaolo Bonzini */ 41845499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 41855499ea73SPaolo Bonzini gpa_t new_pgd, 4186c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4187c50d8ae3SPaolo Bonzini { 4188c50d8ae3SPaolo Bonzini uint i; 4189c50d8ae3SPaolo Bonzini 4190b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 41910be44352SSean Christopherson return true; 41920be44352SSean Christopherson 4193c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 41945499ea73SPaolo Bonzini /* 41955499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 41965499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 41975499ea73SPaolo Bonzini * 0 C 1 2 3 41985499ea73SPaolo Bonzini * 1 C 0 2 3 41995499ea73SPaolo Bonzini * 2 C 0 1 3 42005499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 42015499ea73SPaolo Bonzini */ 4202b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4203b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 42045499ea73SPaolo Bonzini return true; 4205c50d8ae3SPaolo Bonzini } 4206c50d8ae3SPaolo Bonzini 42075499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 42085499ea73SPaolo Bonzini return false; 4209c50d8ae3SPaolo Bonzini } 4210c50d8ae3SPaolo Bonzini 4211c50d8ae3SPaolo Bonzini /* 42125499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 42135499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 42145499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 42155499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 42165499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 42175499ea73SPaolo Bonzini */ 42185499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 42195499ea73SPaolo Bonzini gpa_t new_pgd, 42205499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 42215499ea73SPaolo Bonzini { 42225499ea73SPaolo Bonzini uint i; 42235499ea73SPaolo Bonzini 42245499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 42255499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 42265499ea73SPaolo Bonzini goto hit; 42275499ea73SPaolo Bonzini 42285499ea73SPaolo Bonzini return false; 42295499ea73SPaolo Bonzini 42305499ea73SPaolo Bonzini hit: 42315499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 42325499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 42335499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 42345499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 42355499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 42365499ea73SPaolo Bonzini return true; 42375499ea73SPaolo Bonzini } 42385499ea73SPaolo Bonzini 42395499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 42405499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 42415499ea73SPaolo Bonzini { 42425499ea73SPaolo Bonzini /* 42435499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4244c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4245c50d8ae3SPaolo Bonzini * later if necessary. 4246c50d8ae3SPaolo Bonzini */ 42475499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 42485499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4249c50d8ae3SPaolo Bonzini 42505499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 42515499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 42525499ea73SPaolo Bonzini else 42535499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4254c50d8ae3SPaolo Bonzini } 4255c50d8ae3SPaolo Bonzini 4256d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4257c50d8ae3SPaolo Bonzini { 42580c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 42597a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 42600c1c92f1SPaolo Bonzini 42615499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 42625499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4263b869855bSSean Christopherson return; 4264c50d8ae3SPaolo Bonzini } 4265c50d8ae3SPaolo Bonzini 4266c50d8ae3SPaolo Bonzini /* 4267b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4268b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4269527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4270527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4271b869855bSSean Christopherson */ 4272b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4273b869855bSSean Christopherson 4274b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4275b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4276b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4277b5129100SSean Christopherson } 4278b869855bSSean Christopherson 4279b869855bSSean Christopherson /* 4280b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4281b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4282b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4283b869855bSSean Christopherson * the shadow page tables. 4284c50d8ae3SPaolo Bonzini */ 4285c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4286c50d8ae3SPaolo Bonzini 4287daa5b6c1SBen Gardon /* 4288daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4289daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4290daa5b6c1SBen Gardon */ 4291daa5b6c1SBen Gardon if (!new_role.direct) 4292daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4293b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4294c50d8ae3SPaolo Bonzini } 4295be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4296c50d8ae3SPaolo Bonzini 4297c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4298c50d8ae3SPaolo Bonzini { 4299c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4300c50d8ae3SPaolo Bonzini } 4301c50d8ae3SPaolo Bonzini 4302c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4303c3e5e415SLai Jiangshan unsigned int access) 4304c50d8ae3SPaolo Bonzini { 4305c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4306c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4307c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4308c50d8ae3SPaolo Bonzini return true; 4309c50d8ae3SPaolo Bonzini } 4310c50d8ae3SPaolo Bonzini 4311c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4312c50d8ae3SPaolo Bonzini return true; 4313c50d8ae3SPaolo Bonzini } 4314c50d8ae3SPaolo Bonzini 4315c50d8ae3SPaolo Bonzini return false; 4316c50d8ae3SPaolo Bonzini } 4317c50d8ae3SPaolo Bonzini 4318c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4319c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4320c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4321c50d8ae3SPaolo Bonzini #undef PTTYPE 4322c50d8ae3SPaolo Bonzini 4323c50d8ae3SPaolo Bonzini #define PTTYPE 64 4324c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4325c50d8ae3SPaolo Bonzini #undef PTTYPE 4326c50d8ae3SPaolo Bonzini 4327c50d8ae3SPaolo Bonzini #define PTTYPE 32 4328c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4329c50d8ae3SPaolo Bonzini #undef PTTYPE 4330c50d8ae3SPaolo Bonzini 4331c50d8ae3SPaolo Bonzini static void 4332b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 43335b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4334c50d8ae3SPaolo Bonzini bool pse, bool amd) 4335c50d8ae3SPaolo Bonzini { 4336c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4337c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 43385b7f575cSSean Christopherson u64 high_bits_rsvd; 4339c50d8ae3SPaolo Bonzini 4340c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4341c50d8ae3SPaolo Bonzini 4342c50d8ae3SPaolo Bonzini if (!gbpages) 4343c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4344c50d8ae3SPaolo Bonzini 43455b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 43465b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 43475b7f575cSSean Christopherson else 43485b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 43495b7f575cSSean Christopherson 43505b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 43515b7f575cSSean Christopherson if (!nx) 43525b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 43535b7f575cSSean Christopherson 4354c50d8ae3SPaolo Bonzini /* 4355c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4356c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4357c50d8ae3SPaolo Bonzini */ 4358c50d8ae3SPaolo Bonzini if (amd) 4359c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4360c50d8ae3SPaolo Bonzini 4361c50d8ae3SPaolo Bonzini switch (level) { 4362c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4363c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4364c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4365c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4366c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4367c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4368c50d8ae3SPaolo Bonzini 4369c50d8ae3SPaolo Bonzini if (!pse) { 4370c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4371c50d8ae3SPaolo Bonzini break; 4372c50d8ae3SPaolo Bonzini } 4373c50d8ae3SPaolo Bonzini 4374c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4375c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4376c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4377c50d8ae3SPaolo Bonzini else 4378c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4379c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4380c50d8ae3SPaolo Bonzini break; 4381c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 43825b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 43835b7f575cSSean Christopherson high_bits_rsvd | 43845b7f575cSSean Christopherson rsvd_bits(5, 8) | 43855b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 43865b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 43875b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 43885b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4389c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4390c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4391c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4392c50d8ae3SPaolo Bonzini break; 4393c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 43945b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 43955b7f575cSSean Christopherson nonleaf_bit8_rsvd | 43965b7f575cSSean Christopherson rsvd_bits(7, 7); 4397c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4398c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4399df561f66SGustavo A. R. Silva fallthrough; 4400c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 44015b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 44025b7f575cSSean Christopherson nonleaf_bit8_rsvd | 44035b7f575cSSean Christopherson rsvd_bits(7, 7); 44045b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 44055b7f575cSSean Christopherson gbpages_bit_rsvd; 44065b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 44075b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4408c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4409c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 44105b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 44115b7f575cSSean Christopherson gbpages_bit_rsvd | 4412c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 44135b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4414c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4415c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4416c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4417c50d8ae3SPaolo Bonzini break; 4418c50d8ae3SPaolo Bonzini } 4419c50d8ae3SPaolo Bonzini } 4420c50d8ae3SPaolo Bonzini 442127de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 442227de9250SSean Christopherson { 442327de9250SSean Christopherson /* 442427de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 442527de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 442627de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 442727de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 442827de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 442927de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 443027de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 443127de9250SSean Christopherson */ 443227de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 443327de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 443427de9250SSean Christopherson } 443527de9250SSean Christopherson 4436c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4437c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4438c50d8ae3SPaolo Bonzini { 4439b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 44405b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 44414d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 444227de9250SSean Christopherson guest_can_use_gbpages(vcpu), 44434e9c0d80SSean Christopherson is_cr4_pse(context), 444423493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4445c50d8ae3SPaolo Bonzini } 4446c50d8ae3SPaolo Bonzini 4447c50d8ae3SPaolo Bonzini static void 4448c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 444984ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4450c50d8ae3SPaolo Bonzini { 44515b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 445284ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4453c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4454c50d8ae3SPaolo Bonzini 445584ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 445684ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 445784ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 445884ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 445984ea5c09SLai Jiangshan 44605b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 44615b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 446284ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 446384ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 44645b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4465c50d8ae3SPaolo Bonzini 4466c50d8ae3SPaolo Bonzini /* large page */ 4467c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4468c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 446984ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 447084ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4471c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4472c50d8ae3SPaolo Bonzini 4473c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4474c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4475c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4476c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4477c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4478c50d8ae3SPaolo Bonzini if (!execonly) { 4479c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4480c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4481c50d8ae3SPaolo Bonzini } 4482c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4483c50d8ae3SPaolo Bonzini } 4484c50d8ae3SPaolo Bonzini 4485c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 448684ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4487c50d8ae3SPaolo Bonzini { 4488c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 448984ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 449084ea5c09SLai Jiangshan huge_page_level); 4491c50d8ae3SPaolo Bonzini } 4492c50d8ae3SPaolo Bonzini 44936f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 44946f8e65a6SSean Christopherson { 44956f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 44966f8e65a6SSean Christopherson } 44976f8e65a6SSean Christopherson 4498c50d8ae3SPaolo Bonzini /* 4499c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4500c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4501c50d8ae3SPaolo Bonzini * follow the features in guest. 4502c50d8ae3SPaolo Bonzini */ 450316be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 450416be1d12SSean Christopherson struct kvm_mmu *context) 4505c50d8ae3SPaolo Bonzini { 45068c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 45078c985b2dSSean Christopherson bool is_amd = true; 45088c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 45098c985b2dSSean Christopherson bool is_pse = false; 4510c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4511c50d8ae3SPaolo Bonzini int i; 4512c50d8ae3SPaolo Bonzini 4513a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 45148c985b2dSSean Christopherson 4515c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4516b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4517a972e29cSPaolo Bonzini context->root_role.level, 45187a458f0eSPaolo Bonzini context->root_role.efer_nx, 451927de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4520c50d8ae3SPaolo Bonzini 4521c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4522c50d8ae3SPaolo Bonzini return; 4523c50d8ae3SPaolo Bonzini 4524a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4525c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4526c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4527c50d8ae3SPaolo Bonzini } 4528c50d8ae3SPaolo Bonzini 4529c50d8ae3SPaolo Bonzini } 4530c50d8ae3SPaolo Bonzini 4531c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4532c50d8ae3SPaolo Bonzini { 4533c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4534c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4535c50d8ae3SPaolo Bonzini } 4536c50d8ae3SPaolo Bonzini 4537c50d8ae3SPaolo Bonzini /* 4538c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4539c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4540c50d8ae3SPaolo Bonzini */ 4541c50d8ae3SPaolo Bonzini static void 4542e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4543c50d8ae3SPaolo Bonzini { 4544c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4545c50d8ae3SPaolo Bonzini int i; 4546c50d8ae3SPaolo Bonzini 4547c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4548c50d8ae3SPaolo Bonzini 4549c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4550b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4551a972e29cSPaolo Bonzini context->root_role.level, false, 4552c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 45538c985b2dSSean Christopherson false, true); 4554c50d8ae3SPaolo Bonzini else 4555c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 455684ea5c09SLai Jiangshan reserved_hpa_bits(), false, 455784ea5c09SLai Jiangshan max_huge_page_level); 4558c50d8ae3SPaolo Bonzini 4559c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4560c50d8ae3SPaolo Bonzini return; 4561c50d8ae3SPaolo Bonzini 4562a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4563c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4564c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4565c50d8ae3SPaolo Bonzini } 4566c50d8ae3SPaolo Bonzini } 4567c50d8ae3SPaolo Bonzini 4568c50d8ae3SPaolo Bonzini /* 4569c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4570c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4571c50d8ae3SPaolo Bonzini */ 4572c50d8ae3SPaolo Bonzini static void 4573e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4574c50d8ae3SPaolo Bonzini { 4575c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 457684ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 457784ea5c09SLai Jiangshan max_huge_page_level); 4578c50d8ae3SPaolo Bonzini } 4579c50d8ae3SPaolo Bonzini 4580c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4581c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4582c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4583c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4584c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4585c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4586c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4587c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4588c50d8ae3SPaolo Bonzini 4589c50d8ae3SPaolo Bonzini 4590c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4591c50d8ae3SPaolo Bonzini { 4592c50d8ae3SPaolo Bonzini unsigned byte; 4593c50d8ae3SPaolo Bonzini 4594c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4595c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4596c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4597c50d8ae3SPaolo Bonzini 4598c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4599c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4600c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 460190599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4602c50d8ae3SPaolo Bonzini 4603c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4604c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4605c50d8ae3SPaolo Bonzini 4606c50d8ae3SPaolo Bonzini /* 4607c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4608c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4609c50d8ae3SPaolo Bonzini */ 4610c50d8ae3SPaolo Bonzini 4611c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4612c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4613c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4614c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4615c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4616c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4617c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4618c50d8ae3SPaolo Bonzini u8 smepf = 0; 4619c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4620c50d8ae3SPaolo Bonzini u8 smapf = 0; 4621c50d8ae3SPaolo Bonzini 4622c50d8ae3SPaolo Bonzini if (!ept) { 4623c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4624c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4625c50d8ae3SPaolo Bonzini 4626c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 462790599c28SSean Christopherson if (!efer_nx) 4628c50d8ae3SPaolo Bonzini ff = 0; 4629c50d8ae3SPaolo Bonzini 4630c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4631c50d8ae3SPaolo Bonzini if (!cr0_wp) 4632c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4633c50d8ae3SPaolo Bonzini 4634c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4635c50d8ae3SPaolo Bonzini if (cr4_smep) 4636c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4637c50d8ae3SPaolo Bonzini 4638c50d8ae3SPaolo Bonzini /* 4639c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4640c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4641c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4642c50d8ae3SPaolo Bonzini * conditions are true: 4643c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4644c50d8ae3SPaolo Bonzini * - A user page is accessed 4645c50d8ae3SPaolo Bonzini * - The access is not a fetch 46464f4aa80eSLai Jiangshan * - The access is supervisor mode 46474f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4648c50d8ae3SPaolo Bonzini * 464994b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 465094b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4651c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4652c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4653c50d8ae3SPaolo Bonzini */ 4654c50d8ae3SPaolo Bonzini if (cr4_smap) 4655c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4656c50d8ae3SPaolo Bonzini } 4657c50d8ae3SPaolo Bonzini 4658c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4659c50d8ae3SPaolo Bonzini } 4660c50d8ae3SPaolo Bonzini } 4661c50d8ae3SPaolo Bonzini 4662c50d8ae3SPaolo Bonzini /* 4663c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4664c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4665c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4666c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4667c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4668c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4669c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4670c50d8ae3SPaolo Bonzini * 4671c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4672c50d8ae3SPaolo Bonzini * page tables and the machine state: 4673c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4674c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4675c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4676c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4677c50d8ae3SPaolo Bonzini * 4678c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4679c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4680c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4681c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4682c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4683c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4684c50d8ae3SPaolo Bonzini * only will be masked away. 4685c50d8ae3SPaolo Bonzini */ 46862e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4687c50d8ae3SPaolo Bonzini { 4688c50d8ae3SPaolo Bonzini unsigned bit; 4689c50d8ae3SPaolo Bonzini bool wp; 4690c50d8ae3SPaolo Bonzini 4691c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4692a3ca5281SChenyi Qiang 4693a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4694c50d8ae3SPaolo Bonzini return; 4695c50d8ae3SPaolo Bonzini 46962e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4697c50d8ae3SPaolo Bonzini 4698c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4699c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4700c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4701c50d8ae3SPaolo Bonzini 4702c50d8ae3SPaolo Bonzini pfec = bit << 1; 4703c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4704c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4705c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4706c50d8ae3SPaolo Bonzini 4707c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4708c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4709c50d8ae3SPaolo Bonzini 4710c50d8ae3SPaolo Bonzini /* 4711c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4712c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4713c50d8ae3SPaolo Bonzini */ 4714c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4715c50d8ae3SPaolo Bonzini /* 4716c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4717c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4718c50d8ae3SPaolo Bonzini */ 4719c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4720c50d8ae3SPaolo Bonzini 4721c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4722c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4723c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4724c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4725c50d8ae3SPaolo Bonzini 4726c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4727c50d8ae3SPaolo Bonzini } 4728c50d8ae3SPaolo Bonzini } 4729c50d8ae3SPaolo Bonzini 4730533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4731533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4732c50d8ae3SPaolo Bonzini { 4733533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4734533f9a4bSSean Christopherson return; 4735c50d8ae3SPaolo Bonzini 4736533f9a4bSSean Christopherson reset_rsvds_bits_mask(vcpu, mmu); 4737533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4738533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4739c50d8ae3SPaolo Bonzini } 4740c50d8ae3SPaolo Bonzini 4741fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4742c50d8ae3SPaolo Bonzini { 4743c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4744c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4745c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4746c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4747c50d8ae3SPaolo Bonzini } 4748c50d8ae3SPaolo Bonzini 474984a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4750c50d8ae3SPaolo Bonzini { 4751c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4752c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4753c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4754c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4755c50d8ae3SPaolo Bonzini } 4756c50d8ae3SPaolo Bonzini 47577a7ae829SPaolo Bonzini static union kvm_cpu_role 4758e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 4759e5ed0fb0SPaolo Bonzini { 47607a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4761e5ed0fb0SPaolo Bonzini 4762e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 4763e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 4764e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4765e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 4766e5ed0fb0SPaolo Bonzini 4767e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 4768e5ed0fb0SPaolo Bonzini role.base.direct = 1; 4769e5ed0fb0SPaolo Bonzini return role; 4770e5ed0fb0SPaolo Bonzini } 4771e5ed0fb0SPaolo Bonzini 4772e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 4773e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 4774e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 4775e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 4776e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 477760f3cb60SPaolo Bonzini 477860f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 477960f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 478060f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 478160f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 478260f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 478360f3cb60SPaolo Bonzini else 478460f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 4785e5ed0fb0SPaolo Bonzini 4786e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 4787e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 4788e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 4789e5ed0fb0SPaolo Bonzini 4790e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 4791e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 4792e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 4793e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 4794e5ed0fb0SPaolo Bonzini return role; 4795e5ed0fb0SPaolo Bonzini } 4796e5ed0fb0SPaolo Bonzini 4797d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 4798d468d94bSSean Christopherson { 4799746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 4800746700d2SWei Huang if (tdp_root_level) 4801746700d2SWei Huang return tdp_root_level; 4802746700d2SWei Huang 4803d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 480483013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 4805d468d94bSSean Christopherson return 4; 4806d468d94bSSean Christopherson 480783013059SSean Christopherson return max_tdp_level; 4808d468d94bSSean Christopherson } 4809d468d94bSSean Christopherson 48107a458f0eSPaolo Bonzini static union kvm_mmu_page_role 48118626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 48127a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 4813c50d8ae3SPaolo Bonzini { 48147a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 4815c50d8ae3SPaolo Bonzini 48167a458f0eSPaolo Bonzini role.access = ACC_ALL; 48177a458f0eSPaolo Bonzini role.cr0_wp = true; 48187a458f0eSPaolo Bonzini role.efer_nx = true; 48197a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 48207a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 48217a458f0eSPaolo Bonzini role.ad_disabled = (shadow_accessed_mask == 0); 48227a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 48237a458f0eSPaolo Bonzini role.direct = true; 48247a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 4825c50d8ae3SPaolo Bonzini 4826c50d8ae3SPaolo Bonzini return role; 4827c50d8ae3SPaolo Bonzini } 4828c50d8ae3SPaolo Bonzini 482939e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 4830a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 4831c50d8ae3SPaolo Bonzini { 48328c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 48337a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 4834c50d8ae3SPaolo Bonzini 4835e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 48367a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 4837c50d8ae3SPaolo Bonzini return; 4838c50d8ae3SPaolo Bonzini 4839e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 48407a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 48417a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 4842c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 48435efac074SPaolo Bonzini context->invlpg = NULL; 4844d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4845c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4846c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 4847c50d8ae3SPaolo Bonzini 484836f26787SSean Christopherson if (!is_cr0_pg(context)) 4849c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 485036f26787SSean Christopherson else if (is_cr4_pae(context)) 4851c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4852f4bd6f73SSean Christopherson else 4853c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4854c50d8ae3SPaolo Bonzini 4855533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4856e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 4857c50d8ae3SPaolo Bonzini } 4858c50d8ae3SPaolo Bonzini 48598c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 48607a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 48617a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 4862c50d8ae3SPaolo Bonzini { 4863e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 48647a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 486518db1b17SSean Christopherson return; 4866c50d8ae3SPaolo Bonzini 4867e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 48687a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 486918db1b17SSean Christopherson 487036f26787SSean Christopherson if (!is_cr0_pg(context)) 487184a16226SSean Christopherson nonpaging_init_context(context); 487236f26787SSean Christopherson else if (is_cr4_pae(context)) 4873fe660f72SSean Christopherson paging64_init_context(context); 4874c50d8ae3SPaolo Bonzini else 487584a16226SSean Christopherson paging32_init_context(context); 4876c50d8ae3SPaolo Bonzini 4877533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4878c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 4879c50d8ae3SPaolo Bonzini } 48800f04a2acSVitaly Kuznetsov 4881594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 4882a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 48830f04a2acSVitaly Kuznetsov { 48848c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 488556b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 488656b321f9SPaolo Bonzini 488756b321f9SPaolo Bonzini root_role = cpu_role.base; 488856b321f9SPaolo Bonzini 488956b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 489056b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 489156b321f9SPaolo Bonzini 489256b321f9SPaolo Bonzini /* 489356b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 489456b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 489556b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 489656b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 489756b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 489856b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 489956b321f9SPaolo Bonzini * MMU contexts. 490056b321f9SPaolo Bonzini */ 490156b321f9SPaolo Bonzini root_role.efer_nx = true; 49020f04a2acSVitaly Kuznetsov 49037a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 49040f04a2acSVitaly Kuznetsov } 49050f04a2acSVitaly Kuznetsov 4906dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 4907dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 49080f04a2acSVitaly Kuznetsov { 49098c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4910594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 4911594e91a1SSean Christopherson .cr0 = cr0, 491228f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 4913594e91a1SSean Christopherson .efer = efer, 4914594e91a1SSean Christopherson }; 49157a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 491656b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 491756b321f9SPaolo Bonzini 491856b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 491956b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 492056b321f9SPaolo Bonzini 492156b321f9SPaolo Bonzini root_role = cpu_role.base; 492256b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 4923*84e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 4924*84e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 4925*84e5ffd0SLai Jiangshan root_role.passthrough = 1; 49260f04a2acSVitaly Kuznetsov 49277a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 4928d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 49290f04a2acSVitaly Kuznetsov } 49300f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 4931c50d8ae3SPaolo Bonzini 49327a7ae829SPaolo Bonzini static union kvm_cpu_role 4933c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 4934bb1fcc70SSean Christopherson bool execonly, u8 level) 4935c50d8ae3SPaolo Bonzini { 49367a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4937c50d8ae3SPaolo Bonzini 4938daed87b8SPaolo Bonzini /* 4939daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 4940daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 4941daed87b8SPaolo Bonzini */ 4942daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 4943bb1fcc70SSean Christopherson role.base.level = level; 4944bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 4945c50d8ae3SPaolo Bonzini role.base.direct = false; 4946c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 4947c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 4948c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 4949c50d8ae3SPaolo Bonzini 4950cd6767c3SSean Christopherson role.ext.word = 0; 4951c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 4952cd6767c3SSean Christopherson role.ext.valid = 1; 4953c50d8ae3SPaolo Bonzini 4954c50d8ae3SPaolo Bonzini return role; 4955c50d8ae3SPaolo Bonzini } 4956c50d8ae3SPaolo Bonzini 4957c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 4958cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 4959cc022ae1SLai Jiangshan gpa_t new_eptp) 4960c50d8ae3SPaolo Bonzini { 49618c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4962bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 49637a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 4964c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 4965bb1fcc70SSean Christopherson execonly, level); 4966c50d8ae3SPaolo Bonzini 4967e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 4968e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 4969e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 49707a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 497118db1b17SSean Christopherson 4972c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 4973c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 4974c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 4975c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 4976347a0d0dSPaolo Bonzini 4977c596f147SSean Christopherson update_permission_bitmask(context, true); 497828f091bcSPaolo Bonzini context->pkru_mask = 0; 4979cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 4980e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 4981c50d8ae3SPaolo Bonzini } 49823cffc89dSPaolo Bonzini 4983d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 49843cffc89dSPaolo Bonzini } 4985c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 4986c50d8ae3SPaolo Bonzini 498739e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 4988a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 4989c50d8ae3SPaolo Bonzini { 49908c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 4991c50d8ae3SPaolo Bonzini 4992a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 4993929d1cfaSPaolo Bonzini 4994d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4995c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4996c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 4997c50d8ae3SPaolo Bonzini } 4998c50d8ae3SPaolo Bonzini 499939e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5000a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5001c50d8ae3SPaolo Bonzini { 5002c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5003c50d8ae3SPaolo Bonzini 5004e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5005c50d8ae3SPaolo Bonzini return; 5006c50d8ae3SPaolo Bonzini 5007e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5008d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5009c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5010c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5011c50d8ae3SPaolo Bonzini 5012c50d8ae3SPaolo Bonzini /* 50135efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 50145efac074SPaolo Bonzini * SPTEs. 50155efac074SPaolo Bonzini */ 50165efac074SPaolo Bonzini g_context->invlpg = NULL; 50175efac074SPaolo Bonzini 50185efac074SPaolo Bonzini /* 5019c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5020c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5021c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5022c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5023c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5024c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5025c50d8ae3SPaolo Bonzini */ 5026fa4b5588SSean Christopherson if (!is_paging(vcpu)) 50271f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5028fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 50291f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5030fa4b5588SSean Christopherson else if (is_pae(vcpu)) 50311f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5032fa4b5588SSean Christopherson else 50331f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5034fa4b5588SSean Christopherson 5035533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5036c50d8ae3SPaolo Bonzini } 5037c50d8ae3SPaolo Bonzini 5038c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5039c50d8ae3SPaolo Bonzini { 504039e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5041a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 504239e7e2bfSPaolo Bonzini 5043c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5044a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5045c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5046a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5047c50d8ae3SPaolo Bonzini else 5048a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5049c50d8ae3SPaolo Bonzini } 5050c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5051c50d8ae3SPaolo Bonzini 505249c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 505349c6f875SSean Christopherson { 505449c6f875SSean Christopherson /* 505549c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 505649c6f875SSean Christopherson * information is factored into reserved bit calculations. 5057feb627e8SVitaly Kuznetsov * 5058feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5059feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5060feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5061feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5062feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5063feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5064feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 506549c6f875SSean Christopherson */ 50667a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 50677a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 50687a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5069e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5070e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5071e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 507249c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 507363f5a190SSean Christopherson 507463f5a190SSean Christopherson /* 5075feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5076feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 507763f5a190SSean Christopherson */ 5078feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 507949c6f875SSean Christopherson } 508049c6f875SSean Christopherson 5081c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5082c50d8ae3SPaolo Bonzini { 5083c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5084c9060662SSean Christopherson kvm_init_mmu(vcpu); 5085c50d8ae3SPaolo Bonzini } 5086c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5087c50d8ae3SPaolo Bonzini 5088c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5089c50d8ae3SPaolo Bonzini { 5090c50d8ae3SPaolo Bonzini int r; 5091c50d8ae3SPaolo Bonzini 5092347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5093c50d8ae3SPaolo Bonzini if (r) 5094c50d8ae3SPaolo Bonzini goto out; 5095748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5096c50d8ae3SPaolo Bonzini if (r) 5097c50d8ae3SPaolo Bonzini goto out; 5098347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 50996e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 51006e6ec584SSean Christopherson else 51016e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5102c50d8ae3SPaolo Bonzini if (r) 5103c50d8ae3SPaolo Bonzini goto out; 5104a91f387bSSean Christopherson 5105a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5106a91f387bSSean Christopherson 5107727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5108db01416bSSean Christopherson 5109db01416bSSean Christopherson /* 5110db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5111db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5112db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5113db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5114db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5115db01416bSSean Christopherson */ 5116e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5117c50d8ae3SPaolo Bonzini out: 5118c50d8ae3SPaolo Bonzini return r; 5119c50d8ae3SPaolo Bonzini } 5120c50d8ae3SPaolo Bonzini 5121c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5122c50d8ae3SPaolo Bonzini { 51230c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 51240c1c92f1SPaolo Bonzini 51250c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5126b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 51270c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5128b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 51296d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5130c50d8ae3SPaolo Bonzini } 5131c50d8ae3SPaolo Bonzini 5132527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5133527d5cd7SSean Christopherson { 5134527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5135527d5cd7SSean Christopherson 5136527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5137527d5cd7SSean Christopherson return false; 5138527d5cd7SSean Christopherson 5139527d5cd7SSean Christopherson /* 5140527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5141527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5142527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5143527d5cd7SSean Christopherson * such false positives are relatively rare: 5144527d5cd7SSean Christopherson * 5145527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5146527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5147527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5148527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5149527d5cd7SSean Christopherson */ 5150527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5151527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5152527d5cd7SSean Christopherson } 5153527d5cd7SSean Christopherson 5154527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5155527d5cd7SSean Christopherson { 5156527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5157527d5cd7SSean Christopherson int i; 5158527d5cd7SSean Christopherson 5159527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5160527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5161527d5cd7SSean Christopherson 5162527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5163527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5164527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5165527d5cd7SSean Christopherson } 5166527d5cd7SSean Christopherson 5167527d5cd7SSean Christopherson if (roots_to_free) 5168527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5169527d5cd7SSean Christopherson } 5170527d5cd7SSean Christopherson 5171527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5172527d5cd7SSean Christopherson { 5173527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5174527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5175527d5cd7SSean Christopherson } 5176527d5cd7SSean Christopherson 5177c50d8ae3SPaolo Bonzini static bool need_remote_flush(u64 old, u64 new) 5178c50d8ae3SPaolo Bonzini { 5179c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old)) 5180c50d8ae3SPaolo Bonzini return false; 5181c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(new)) 5182c50d8ae3SPaolo Bonzini return true; 5183c50d8ae3SPaolo Bonzini if ((old ^ new) & PT64_BASE_ADDR_MASK) 5184c50d8ae3SPaolo Bonzini return true; 5185c50d8ae3SPaolo Bonzini old ^= shadow_nx_mask; 5186c50d8ae3SPaolo Bonzini new ^= shadow_nx_mask; 5187c50d8ae3SPaolo Bonzini return (old & ~new & PT64_PERM_MASK) != 0; 5188c50d8ae3SPaolo Bonzini } 5189c50d8ae3SPaolo Bonzini 5190c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5191c50d8ae3SPaolo Bonzini int *bytes) 5192c50d8ae3SPaolo Bonzini { 5193c50d8ae3SPaolo Bonzini u64 gentry = 0; 5194c50d8ae3SPaolo Bonzini int r; 5195c50d8ae3SPaolo Bonzini 5196c50d8ae3SPaolo Bonzini /* 5197c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5198c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5199c50d8ae3SPaolo Bonzini * when they have the same mode. 5200c50d8ae3SPaolo Bonzini */ 5201c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5202c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5203c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5204c50d8ae3SPaolo Bonzini *bytes = 8; 5205c50d8ae3SPaolo Bonzini } 5206c50d8ae3SPaolo Bonzini 5207c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5208c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5209c50d8ae3SPaolo Bonzini if (r) 5210c50d8ae3SPaolo Bonzini gentry = 0; 5211c50d8ae3SPaolo Bonzini } 5212c50d8ae3SPaolo Bonzini 5213c50d8ae3SPaolo Bonzini return gentry; 5214c50d8ae3SPaolo Bonzini } 5215c50d8ae3SPaolo Bonzini 5216c50d8ae3SPaolo Bonzini /* 5217c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5218c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5219c50d8ae3SPaolo Bonzini */ 5220c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5221c50d8ae3SPaolo Bonzini { 5222c50d8ae3SPaolo Bonzini /* 5223c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5224c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5225c50d8ae3SPaolo Bonzini */ 52263bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5227c50d8ae3SPaolo Bonzini return false; 5228c50d8ae3SPaolo Bonzini 5229c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5230c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5231c50d8ae3SPaolo Bonzini } 5232c50d8ae3SPaolo Bonzini 5233c50d8ae3SPaolo Bonzini /* 5234c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5235c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5236c50d8ae3SPaolo Bonzini */ 5237c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5238c50d8ae3SPaolo Bonzini int bytes) 5239c50d8ae3SPaolo Bonzini { 5240c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5241c50d8ae3SPaolo Bonzini 5242c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5243c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5244c50d8ae3SPaolo Bonzini 5245c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5246bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5247c50d8ae3SPaolo Bonzini 5248c50d8ae3SPaolo Bonzini /* 5249c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5250c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5251c50d8ae3SPaolo Bonzini */ 5252c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5253c50d8ae3SPaolo Bonzini return false; 5254c50d8ae3SPaolo Bonzini 5255c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5256c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5257c50d8ae3SPaolo Bonzini 5258c50d8ae3SPaolo Bonzini return misaligned; 5259c50d8ae3SPaolo Bonzini } 5260c50d8ae3SPaolo Bonzini 5261c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5262c50d8ae3SPaolo Bonzini { 5263c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5264c50d8ae3SPaolo Bonzini u64 *spte; 5265c50d8ae3SPaolo Bonzini int level; 5266c50d8ae3SPaolo Bonzini 5267c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5268c50d8ae3SPaolo Bonzini level = sp->role.level; 5269c50d8ae3SPaolo Bonzini *nspte = 1; 5270bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5271c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5272c50d8ae3SPaolo Bonzini /* 5273c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5274c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5275c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5276c50d8ae3SPaolo Bonzini */ 5277c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5278c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5279c50d8ae3SPaolo Bonzini page_offset <<= 1; 5280c50d8ae3SPaolo Bonzini *nspte = 2; 5281c50d8ae3SPaolo Bonzini } 5282c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5283c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5284c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5285c50d8ae3SPaolo Bonzini return NULL; 5286c50d8ae3SPaolo Bonzini } 5287c50d8ae3SPaolo Bonzini 5288c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5289c50d8ae3SPaolo Bonzini return spte; 5290c50d8ae3SPaolo Bonzini } 5291c50d8ae3SPaolo Bonzini 5292c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5293c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5294c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5295c50d8ae3SPaolo Bonzini { 5296c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5297c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5298c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5299c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5300c50d8ae3SPaolo Bonzini int npte; 530106152b2dSLai Jiangshan bool flush = false; 5302c50d8ae3SPaolo Bonzini 5303c50d8ae3SPaolo Bonzini /* 5304c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5305c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5306c50d8ae3SPaolo Bonzini */ 5307c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5308c50d8ae3SPaolo Bonzini return; 5309c50d8ae3SPaolo Bonzini 5310c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5311c50d8ae3SPaolo Bonzini 5312c50d8ae3SPaolo Bonzini /* 5313c50d8ae3SPaolo Bonzini * No need to care whether allocation memory is successful 5314d9f6e12fSIngo Molnar * or not since pte prefetch is skipped if it does not have 5315c50d8ae3SPaolo Bonzini * enough objects in the cache. 5316c50d8ae3SPaolo Bonzini */ 5317378f5cd6SSean Christopherson mmu_topup_memory_caches(vcpu, true); 5318c50d8ae3SPaolo Bonzini 5319531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5320c50d8ae3SPaolo Bonzini 5321c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5322c50d8ae3SPaolo Bonzini 5323c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5324c50d8ae3SPaolo Bonzini 5325767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5326c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5327c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5328c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5329c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5330c50d8ae3SPaolo Bonzini continue; 5331c50d8ae3SPaolo Bonzini } 5332c50d8ae3SPaolo Bonzini 5333c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5334c50d8ae3SPaolo Bonzini if (!spte) 5335c50d8ae3SPaolo Bonzini continue; 5336c50d8ae3SPaolo Bonzini 5337c50d8ae3SPaolo Bonzini while (npte--) { 5338c50d8ae3SPaolo Bonzini entry = *spte; 53392de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5340c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5341c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 5342c50d8ae3SPaolo Bonzini if (need_remote_flush(entry, *spte)) 534306152b2dSLai Jiangshan flush = true; 5344c50d8ae3SPaolo Bonzini ++spte; 5345c50d8ae3SPaolo Bonzini } 5346c50d8ae3SPaolo Bonzini } 534706152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5348531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5349c50d8ae3SPaolo Bonzini } 5350c50d8ae3SPaolo Bonzini 5351736c291cSSean Christopherson int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5352c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5353c50d8ae3SPaolo Bonzini { 535492daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5355347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5356c50d8ae3SPaolo Bonzini 5357b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5358ddce6208SSean Christopherson return RET_PF_RETRY; 5359ddce6208SSean Christopherson 5360c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5361c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5362736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5363c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5364c50d8ae3SPaolo Bonzini goto emulate; 5365c50d8ae3SPaolo Bonzini } 5366c50d8ae3SPaolo Bonzini 5367c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 53687a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 53697a02674dSSean Christopherson lower_32_bits(error_code), false); 537019025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 53717b367bc9SSean Christopherson return -EIO; 5372c50d8ae3SPaolo Bonzini } 5373c50d8ae3SPaolo Bonzini 5374c50d8ae3SPaolo Bonzini if (r < 0) 5375c50d8ae3SPaolo Bonzini return r; 537683a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 537783a2ba4cSSean Christopherson return 1; 5378c50d8ae3SPaolo Bonzini 5379c50d8ae3SPaolo Bonzini /* 5380c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5381c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5382c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5383c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5384c50d8ae3SPaolo Bonzini * and resume the guest. 5385c50d8ae3SPaolo Bonzini */ 5386347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5387c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5388736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5389c50d8ae3SPaolo Bonzini return 1; 5390c50d8ae3SPaolo Bonzini } 5391c50d8ae3SPaolo Bonzini 5392c50d8ae3SPaolo Bonzini /* 5393c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5394c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5395c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5396c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5397c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5398c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5399c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5400c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5401c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5402c50d8ae3SPaolo Bonzini */ 5403736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 540492daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5405c50d8ae3SPaolo Bonzini emulate: 5406736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5407c50d8ae3SPaolo Bonzini insn_len); 5408c50d8ae3SPaolo Bonzini } 5409c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5410c50d8ae3SPaolo Bonzini 54115efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 54125efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5413c50d8ae3SPaolo Bonzini { 5414c50d8ae3SPaolo Bonzini int i; 5415c50d8ae3SPaolo Bonzini 54165efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 54175efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 54185efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5419c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5420c50d8ae3SPaolo Bonzini return; 5421c50d8ae3SPaolo Bonzini 5422e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 54235efac074SPaolo Bonzini } 54245efac074SPaolo Bonzini 54255efac074SPaolo Bonzini if (!mmu->invlpg) 54265efac074SPaolo Bonzini return; 54275efac074SPaolo Bonzini 54285efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5429b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5430c50d8ae3SPaolo Bonzini 5431c50d8ae3SPaolo Bonzini /* 5432c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5433c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5434c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5435c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5436c50d8ae3SPaolo Bonzini * just always sync it. 5437c50d8ae3SPaolo Bonzini * 5438c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5439c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5440c50d8ae3SPaolo Bonzini * for them. 5441c50d8ae3SPaolo Bonzini */ 5442c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5443c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5444c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 54455efac074SPaolo Bonzini } else { 54465efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 54475efac074SPaolo Bonzini } 54485efac074SPaolo Bonzini } 5449c50d8ae3SPaolo Bonzini 54505efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 54515efac074SPaolo Bonzini { 545205b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5453c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5454c50d8ae3SPaolo Bonzini } 5455c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5456c50d8ae3SPaolo Bonzini 54575efac074SPaolo Bonzini 5458c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5459c50d8ae3SPaolo Bonzini { 5460c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5461c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5462c50d8ae3SPaolo Bonzini uint i; 5463c50d8ae3SPaolo Bonzini 5464c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 5465b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5466c50d8ae3SPaolo Bonzini tlb_flush = true; 5467c50d8ae3SPaolo Bonzini } 5468c50d8ae3SPaolo Bonzini 5469c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5470c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5471be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 5472c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5473c50d8ae3SPaolo Bonzini tlb_flush = true; 5474c50d8ae3SPaolo Bonzini } 5475c50d8ae3SPaolo Bonzini } 5476c50d8ae3SPaolo Bonzini 5477c50d8ae3SPaolo Bonzini if (tlb_flush) 5478e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5479c50d8ae3SPaolo Bonzini 5480c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5481c50d8ae3SPaolo Bonzini 5482c50d8ae3SPaolo Bonzini /* 5483c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5484c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5485c50d8ae3SPaolo Bonzini * for them. 5486c50d8ae3SPaolo Bonzini */ 5487c50d8ae3SPaolo Bonzini } 5488c50d8ae3SPaolo Bonzini 5489746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5490746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5491c50d8ae3SPaolo Bonzini { 5492bde77235SSean Christopherson tdp_enabled = enable_tdp; 5493746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 549483013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5495703c335dSSean Christopherson 5496703c335dSSean Christopherson /* 54971d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5498703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5499703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5500703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5501703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5502703c335dSSean Christopherson */ 5503703c335dSSean Christopherson if (tdp_enabled) 55041d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5505703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 55061d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5507703c335dSSean Christopherson else 55081d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5509c50d8ae3SPaolo Bonzini } 5510bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5511c50d8ae3SPaolo Bonzini 5512c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5513269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5514269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5515269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5516c50d8ae3SPaolo Bonzini 5517c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5518c50d8ae3SPaolo Bonzini static __always_inline bool 5519269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5520c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 55211a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 55221a61b7dbSSean Christopherson bool flush) 5523c50d8ae3SPaolo Bonzini { 5524c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5525c50d8ae3SPaolo Bonzini 5526c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5527c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5528c50d8ae3SPaolo Bonzini if (iterator.rmap) 55290a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5530c50d8ae3SPaolo Bonzini 5531531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5532302695a5SSean Christopherson if (flush && flush_on_yield) { 5533c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5534c50d8ae3SPaolo Bonzini start_gfn, 5535c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5536c50d8ae3SPaolo Bonzini flush = false; 5537c50d8ae3SPaolo Bonzini } 5538531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5539c50d8ae3SPaolo Bonzini } 5540c50d8ae3SPaolo Bonzini } 5541c50d8ae3SPaolo Bonzini 5542c50d8ae3SPaolo Bonzini return flush; 5543c50d8ae3SPaolo Bonzini } 5544c50d8ae3SPaolo Bonzini 5545c50d8ae3SPaolo Bonzini static __always_inline bool 5546269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5547c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5548302695a5SSean Christopherson bool flush_on_yield) 5549c50d8ae3SPaolo Bonzini { 5550c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5551c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5552c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 55531a61b7dbSSean Christopherson flush_on_yield, false); 5554c50d8ae3SPaolo Bonzini } 5555c50d8ae3SPaolo Bonzini 5556c50d8ae3SPaolo Bonzini static __always_inline bool 5557610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5558302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5559c50d8ae3SPaolo Bonzini { 55603bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5561302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5562c50d8ae3SPaolo Bonzini } 5563c50d8ae3SPaolo Bonzini 5564c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5565c50d8ae3SPaolo Bonzini { 55664a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 55674a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5568c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 556903ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5570cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5571c50d8ae3SPaolo Bonzini } 5572c50d8ae3SPaolo Bonzini 557304d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5574c50d8ae3SPaolo Bonzini { 5575c50d8ae3SPaolo Bonzini struct page *page; 5576c50d8ae3SPaolo Bonzini int i; 5577c50d8ae3SPaolo Bonzini 5578b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5579b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 558004d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 558104d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 558204d28e37SSean Christopherson 558327f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 558427f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 558527f4fca2SLai Jiangshan return 0; 558627f4fca2SLai Jiangshan 5587c50d8ae3SPaolo Bonzini /* 5588c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5589c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5590c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5591c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 559204d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 559304d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 559404d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 559504d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 559684432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5597c50d8ae3SPaolo Bonzini */ 5598d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5599c50d8ae3SPaolo Bonzini return 0; 5600c50d8ae3SPaolo Bonzini 5601c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5602c50d8ae3SPaolo Bonzini if (!page) 5603c50d8ae3SPaolo Bonzini return -ENOMEM; 5604c50d8ae3SPaolo Bonzini 5605c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 56064a98623dSSean Christopherson 56074a98623dSSean Christopherson /* 56084a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 56094a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 56104a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 56114a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 56124a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 56134a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 56144a98623dSSean Christopherson */ 56154a98623dSSean Christopherson if (!tdp_enabled) 56164a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 56174a98623dSSean Christopherson else 56184a98623dSSean Christopherson WARN_ON_ONCE(shadow_me_mask); 56194a98623dSSean Christopherson 5620c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5621c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5622c50d8ae3SPaolo Bonzini 5623c50d8ae3SPaolo Bonzini return 0; 5624c50d8ae3SPaolo Bonzini } 5625c50d8ae3SPaolo Bonzini 5626c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5627c50d8ae3SPaolo Bonzini { 5628c50d8ae3SPaolo Bonzini int ret; 5629c50d8ae3SPaolo Bonzini 56305962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 56315f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 56325f6078f9SSean Christopherson 56335962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 56345f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 56355962bfb7SSean Christopherson 563696880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 563796880883SSean Christopherson 5638c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5639c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5640c50d8ae3SPaolo Bonzini 564104d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5642c50d8ae3SPaolo Bonzini if (ret) 5643c50d8ae3SPaolo Bonzini return ret; 5644c50d8ae3SPaolo Bonzini 564504d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5646c50d8ae3SPaolo Bonzini if (ret) 5647c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5648c50d8ae3SPaolo Bonzini 5649c50d8ae3SPaolo Bonzini return ret; 5650c50d8ae3SPaolo Bonzini fail_allocate_root: 5651c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5652c50d8ae3SPaolo Bonzini return ret; 5653c50d8ae3SPaolo Bonzini } 5654c50d8ae3SPaolo Bonzini 5655c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5656c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5657c50d8ae3SPaolo Bonzini { 5658c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5659c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5660c50d8ae3SPaolo Bonzini 5661c50d8ae3SPaolo Bonzini restart: 5662c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5663c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5664c50d8ae3SPaolo Bonzini /* 5665c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5666c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5667c50d8ae3SPaolo Bonzini */ 5668c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5669c50d8ae3SPaolo Bonzini break; 5670c50d8ae3SPaolo Bonzini 5671c50d8ae3SPaolo Bonzini /* 5672f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5673f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5674f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5675c50d8ae3SPaolo Bonzini */ 5676f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5677c50d8ae3SPaolo Bonzini continue; 5678c50d8ae3SPaolo Bonzini 5679c50d8ae3SPaolo Bonzini /* 5680c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5681c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5682c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5683c50d8ae3SPaolo Bonzini * be in active use by the guest. 5684c50d8ae3SPaolo Bonzini */ 5685c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5686531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5687c50d8ae3SPaolo Bonzini batch = 0; 5688c50d8ae3SPaolo Bonzini goto restart; 5689c50d8ae3SPaolo Bonzini } 5690c50d8ae3SPaolo Bonzini 5691c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, 5692c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages, &nr_zapped)) { 5693c50d8ae3SPaolo Bonzini batch += nr_zapped; 5694c50d8ae3SPaolo Bonzini goto restart; 5695c50d8ae3SPaolo Bonzini } 5696c50d8ae3SPaolo Bonzini } 5697c50d8ae3SPaolo Bonzini 5698c50d8ae3SPaolo Bonzini /* 56997ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 57007ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 57017ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 57027ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 57037ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 57047ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 57057ae5840eSSean Christopherson * running with an obsolete MMU. 5706c50d8ae3SPaolo Bonzini */ 5707c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5708c50d8ae3SPaolo Bonzini } 5709c50d8ae3SPaolo Bonzini 5710c50d8ae3SPaolo Bonzini /* 5711c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5712c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5713c50d8ae3SPaolo Bonzini * 5714c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5715c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5716c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5717c50d8ae3SPaolo Bonzini * after calling the function. 5718c50d8ae3SPaolo Bonzini */ 5719c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5720c50d8ae3SPaolo Bonzini { 5721c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5722c50d8ae3SPaolo Bonzini 5723531810caSBen Gardon write_lock(&kvm->mmu_lock); 5724c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5725c50d8ae3SPaolo Bonzini 5726c50d8ae3SPaolo Bonzini /* 5727c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5728c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5729c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5730c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5731c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5732c50d8ae3SPaolo Bonzini */ 5733c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5734c50d8ae3SPaolo Bonzini 57352f6f66ccSSean Christopherson /* 57362f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 57372f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 57382f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 57392f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5740b7cccd39SBen Gardon */ 5741b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5742b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5743b7cccd39SBen Gardon 5744c50d8ae3SPaolo Bonzini /* 5745c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5746c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5747c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5748c50d8ae3SPaolo Bonzini * 5749c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5750c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5751c50d8ae3SPaolo Bonzini */ 5752527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5753c50d8ae3SPaolo Bonzini 5754c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5755faaf05b0SBen Gardon 5756531810caSBen Gardon write_unlock(&kvm->mmu_lock); 57574c6654bdSBen Gardon 5758f28e9c7fSSean Christopherson /* 5759f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5760f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5761f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5762f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5763f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5764f28e9c7fSSean Christopherson * lead to use-after-free. 5765f28e9c7fSSean Christopherson */ 576622b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 57674c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5768c50d8ae3SPaolo Bonzini } 5769c50d8ae3SPaolo Bonzini 5770c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5771c50d8ae3SPaolo Bonzini { 5772c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5773c50d8ae3SPaolo Bonzini } 5774c50d8ae3SPaolo Bonzini 5775c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5776c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5777c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5778c50d8ae3SPaolo Bonzini { 5779c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5780c50d8ae3SPaolo Bonzini } 5781c50d8ae3SPaolo Bonzini 5782a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5783c50d8ae3SPaolo Bonzini { 5784c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5785a1a39128SPaolo Bonzini int r; 5786c50d8ae3SPaolo Bonzini 5787a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5788a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5789a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5790ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5791ce25681dSSean Christopherson 5792a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5793a1a39128SPaolo Bonzini if (r < 0) 5794a1a39128SPaolo Bonzini return r; 5795fe5db27dSBen Gardon 5796c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5797c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5798c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5799a1a39128SPaolo Bonzini return 0; 5800c50d8ae3SPaolo Bonzini } 5801c50d8ae3SPaolo Bonzini 5802c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 5803c50d8ae3SPaolo Bonzini { 5804c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5805c50d8ae3SPaolo Bonzini 5806c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 5807fe5db27dSBen Gardon 5808fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 5809c50d8ae3SPaolo Bonzini } 5810c50d8ae3SPaolo Bonzini 581121fa3246SSean Christopherson static bool __kvm_zap_rmaps(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 581221fa3246SSean Christopherson { 581321fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 581421fa3246SSean Christopherson struct kvm_memslots *slots; 5815f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 581621fa3246SSean Christopherson bool flush = false; 581721fa3246SSean Christopherson gfn_t start, end; 5818f4209439SMaciej S. Szmigiero int i; 581921fa3246SSean Christopherson 582021fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 582121fa3246SSean Christopherson return flush; 582221fa3246SSean Christopherson 582321fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 582421fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 5825f4209439SMaciej S. Szmigiero 5826f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 5827f4209439SMaciej S. Szmigiero memslot = iter.slot; 582821fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 582921fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 5830f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 583121fa3246SSean Christopherson continue; 583221fa3246SSean Christopherson 583321fa3246SSean Christopherson flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, 58346ff94f27SDavid Matlack 583521fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 583621fa3246SSean Christopherson start, end - 1, true, flush); 583721fa3246SSean Christopherson } 583821fa3246SSean Christopherson } 583921fa3246SSean Christopherson 584021fa3246SSean Christopherson return flush; 584121fa3246SSean Christopherson } 584221fa3246SSean Christopherson 584388f58535SMaxim Levitsky /* 584488f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 584588f58535SMaxim Levitsky * (not including it) 584688f58535SMaxim Levitsky */ 5847c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 5848c50d8ae3SPaolo Bonzini { 584921fa3246SSean Christopherson bool flush; 5850c50d8ae3SPaolo Bonzini int i; 5851c50d8ae3SPaolo Bonzini 5852f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 5853f4209439SMaciej S. Szmigiero return; 5854f4209439SMaciej S. Szmigiero 5855531810caSBen Gardon write_lock(&kvm->mmu_lock); 58565a324c24SSean Christopherson 5857edb298c6SMaxim Levitsky kvm_inc_notifier_count(kvm, gfn_start, gfn_end); 5858edb298c6SMaxim Levitsky 585921fa3246SSean Christopherson flush = __kvm_zap_rmaps(kvm, gfn_start, gfn_end); 58606103bc07SBen Gardon 58616103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 58626103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 5863f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 5864f47e5bbbSSean Christopherson gfn_end, true, flush); 58656103bc07SBen Gardon } 58665a324c24SSean Christopherson 58675a324c24SSean Christopherson if (flush) 5868bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 5869bc3b3c10SSean Christopherson gfn_end - gfn_start); 58705a324c24SSean Christopherson 5871edb298c6SMaxim Levitsky kvm_dec_notifier_count(kvm, gfn_start, gfn_end); 5872edb298c6SMaxim Levitsky 58735a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 5874c50d8ae3SPaolo Bonzini } 5875c50d8ae3SPaolo Bonzini 5876c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 58770a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 5878269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5879c50d8ae3SPaolo Bonzini { 58801346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 5881c50d8ae3SPaolo Bonzini } 5882c50d8ae3SPaolo Bonzini 5883c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 5884269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 58853c9bd400SJay Zhou int start_level) 5886c50d8ae3SPaolo Bonzini { 5887e2209710SBen Gardon bool flush = false; 5888c50d8ae3SPaolo Bonzini 5889e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 5890531810caSBen Gardon write_lock(&kvm->mmu_lock); 58913c9bd400SJay Zhou flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, 5892e2209710SBen Gardon start_level, KVM_MAX_HUGEPAGE_LEVEL, 5893e2209710SBen Gardon false); 5894531810caSBen Gardon write_unlock(&kvm->mmu_lock); 5895e2209710SBen Gardon } 5896c50d8ae3SPaolo Bonzini 589724ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 589824ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 589924ae4cfaSBen Gardon flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 590024ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 590124ae4cfaSBen Gardon } 590224ae4cfaSBen Gardon 5903c50d8ae3SPaolo Bonzini /* 59046ff94f27SDavid Matlack * Flush TLBs if any SPTEs had to be write-protected to ensure that 59056ff94f27SDavid Matlack * guest writes are reflected in the dirty bitmap before the memslot 59066ff94f27SDavid Matlack * update completes, i.e. before enabling dirty logging is visible to 59076ff94f27SDavid Matlack * userspace. 59086ff94f27SDavid Matlack * 59096ff94f27SDavid Matlack * Perform the TLB flush outside the mmu_lock to reduce the amount of 59106ff94f27SDavid Matlack * time the lock is held. However, this does mean that another CPU can 59116ff94f27SDavid Matlack * now grab mmu_lock and encounter a write-protected SPTE while CPUs 59126ff94f27SDavid Matlack * still have a writable mapping for the associated GFN in their TLB. 59136ff94f27SDavid Matlack * 59146ff94f27SDavid Matlack * This is safe but requires KVM to be careful when making decisions 59156ff94f27SDavid Matlack * based on the write-protection status of an SPTE. Specifically, KVM 59166ff94f27SDavid Matlack * also write-protects SPTEs to monitor changes to guest page tables 59176ff94f27SDavid Matlack * during shadow paging, and must guarantee no CPUs can write to those 59186ff94f27SDavid Matlack * page before the lock is dropped. As mentioned in the previous 59196ff94f27SDavid Matlack * paragraph, a write-protected SPTE is no guarantee that CPU cannot 59206ff94f27SDavid Matlack * perform writes. So to determine if a TLB flush is truly required, KVM 59216ff94f27SDavid Matlack * will clear a separate software-only bit (MMU-writable) and skip the 59226ff94f27SDavid Matlack * flush if-and-only-if this bit was already clear. 59236ff94f27SDavid Matlack * 592402844ac1SDavid Matlack * See is_writable_pte() for more details. 5925c50d8ae3SPaolo Bonzini */ 5926c50d8ae3SPaolo Bonzini if (flush) 59277f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 5928c50d8ae3SPaolo Bonzini } 5929c50d8ae3SPaolo Bonzini 5930cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 5931cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 5932cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 5933cb00a70bSDavid Matlack u64 start, u64 end, 5934cb00a70bSDavid Matlack int target_level) 5935cb00a70bSDavid Matlack { 5936cb00a70bSDavid Matlack if (is_tdp_mmu_enabled(kvm)) 5937cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, 5938cb00a70bSDavid Matlack target_level, false); 5939cb00a70bSDavid Matlack 5940cb00a70bSDavid Matlack /* 5941cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 5942cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 5943cb00a70bSDavid Matlack */ 5944cb00a70bSDavid Matlack } 5945cb00a70bSDavid Matlack 5946a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 5947a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 5948a3fe5dbdSDavid Matlack int target_level) 5949a3fe5dbdSDavid Matlack { 5950a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 5951a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 5952a3fe5dbdSDavid Matlack 5953a3fe5dbdSDavid Matlack if (is_tdp_mmu_enabled(kvm)) { 5954a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 5955cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 5956a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 5957a3fe5dbdSDavid Matlack } 5958a3fe5dbdSDavid Matlack 5959a3fe5dbdSDavid Matlack /* 5960a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 5961a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 5962a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 5963a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 5964a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 5965a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 5966a3fe5dbdSDavid Matlack * SPTEs. 5967a3fe5dbdSDavid Matlack */ 5968a3fe5dbdSDavid Matlack } 5969a3fe5dbdSDavid Matlack 5970c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 59710a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 5972269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5973c50d8ae3SPaolo Bonzini { 5974c50d8ae3SPaolo Bonzini u64 *sptep; 5975c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 5976c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 5977c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 5978c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5979c50d8ae3SPaolo Bonzini 5980c50d8ae3SPaolo Bonzini restart: 5981c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 598257354682SSean Christopherson sp = sptep_to_sp(sptep); 5983c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(*sptep); 5984c50d8ae3SPaolo Bonzini 5985c50d8ae3SPaolo Bonzini /* 5986c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 5987c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 5988c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 5989c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 5990c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 5991c50d8ae3SPaolo Bonzini */ 5992c50d8ae3SPaolo Bonzini if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && 59939eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 59949eba50f8SSean Christopherson pfn, PG_LEVEL_NUM)) { 599571f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 5996c50d8ae3SPaolo Bonzini 5997c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 5998c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 5999c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6000c50d8ae3SPaolo Bonzini else 6001c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6002c50d8ae3SPaolo Bonzini 6003c50d8ae3SPaolo Bonzini goto restart; 6004c50d8ae3SPaolo Bonzini } 6005c50d8ae3SPaolo Bonzini } 6006c50d8ae3SPaolo Bonzini 6007c50d8ae3SPaolo Bonzini return need_tlb_flush; 6008c50d8ae3SPaolo Bonzini } 6009c50d8ae3SPaolo Bonzini 6010c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6011269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6012c50d8ae3SPaolo Bonzini { 6013e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6014531810caSBen Gardon write_lock(&kvm->mmu_lock); 6015610265eaSDavid Matlack /* 6016610265eaSDavid Matlack * Zap only 4k SPTEs since the legacy MMU only supports dirty 6017610265eaSDavid Matlack * logging at a 4k granularity and never creates collapsible 6018610265eaSDavid Matlack * 2m SPTEs during dirty logging. 6019610265eaSDavid Matlack */ 60204b85c921SSean Christopherson if (slot_handle_level_4k(kvm, slot, kvm_mmu_zap_collapsible_spte, true)) 6021302695a5SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 6022531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6023e2209710SBen Gardon } 60242db6f772SBen Gardon 60252db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60262db6f772SBen Gardon read_lock(&kvm->mmu_lock); 60274b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 60282db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 60292db6f772SBen Gardon } 6030c50d8ae3SPaolo Bonzini } 6031c50d8ae3SPaolo Bonzini 6032b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 60336c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6034b3594ffbSSean Christopherson { 6035b3594ffbSSean Christopherson /* 60367f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6037302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 60387f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 60397f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 60407f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6041b3594ffbSSean Christopherson */ 6042b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6043cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6044cec37648SSean Christopherson memslot->npages); 6045b3594ffbSSean Christopherson } 6046b3594ffbSSean Christopherson 6047c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6048269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6049c50d8ae3SPaolo Bonzini { 6050e2209710SBen Gardon bool flush = false; 6051c50d8ae3SPaolo Bonzini 6052e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6053531810caSBen Gardon write_lock(&kvm->mmu_lock); 6054610265eaSDavid Matlack /* 6055610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6056610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6057610265eaSDavid Matlack */ 6058610265eaSDavid Matlack flush = slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6059531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6060e2209710SBen Gardon } 6061c50d8ae3SPaolo Bonzini 606224ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 606324ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 606424ae4cfaSBen Gardon flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 606524ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 606624ae4cfaSBen Gardon } 606724ae4cfaSBen Gardon 6068c50d8ae3SPaolo Bonzini /* 6069c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6070c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6071c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6072c50d8ae3SPaolo Bonzini * dirty_bitmap. 6073c50d8ae3SPaolo Bonzini */ 6074c50d8ae3SPaolo Bonzini if (flush) 60757f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6076c50d8ae3SPaolo Bonzini } 6077c50d8ae3SPaolo Bonzini 6078c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6079c50d8ae3SPaolo Bonzini { 6080c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6081c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6082c50d8ae3SPaolo Bonzini int ign; 6083c50d8ae3SPaolo Bonzini 6084531810caSBen Gardon write_lock(&kvm->mmu_lock); 6085c50d8ae3SPaolo Bonzini restart: 6086c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6087f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6088c50d8ae3SPaolo Bonzini continue; 6089c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6090c50d8ae3SPaolo Bonzini goto restart; 6091531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6092c50d8ae3SPaolo Bonzini goto restart; 6093c50d8ae3SPaolo Bonzini } 6094c50d8ae3SPaolo Bonzini 6095c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6096faaf05b0SBen Gardon 6097897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6098faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6099faaf05b0SBen Gardon 6100531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6101c50d8ae3SPaolo Bonzini } 6102c50d8ae3SPaolo Bonzini 6103c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6104c50d8ae3SPaolo Bonzini { 6105c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6106c50d8ae3SPaolo Bonzini 6107c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6108c50d8ae3SPaolo Bonzini 6109c50d8ae3SPaolo Bonzini /* 6110c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6111c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6112c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6113c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6114c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6115c50d8ae3SPaolo Bonzini */ 6116c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6117c50d8ae3SPaolo Bonzini 6118c50d8ae3SPaolo Bonzini /* 6119c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6120c50d8ae3SPaolo Bonzini * zap all shadow pages. 6121c50d8ae3SPaolo Bonzini */ 6122c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6123c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6124c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6125c50d8ae3SPaolo Bonzini } 6126c50d8ae3SPaolo Bonzini } 6127c50d8ae3SPaolo Bonzini 6128c50d8ae3SPaolo Bonzini static unsigned long 6129c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6130c50d8ae3SPaolo Bonzini { 6131c50d8ae3SPaolo Bonzini struct kvm *kvm; 6132c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6133c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6134c50d8ae3SPaolo Bonzini 6135c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6136c50d8ae3SPaolo Bonzini 6137c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6138c50d8ae3SPaolo Bonzini int idx; 6139c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6140c50d8ae3SPaolo Bonzini 6141c50d8ae3SPaolo Bonzini /* 6142c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6143c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6144c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6145c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6146c50d8ae3SPaolo Bonzini */ 6147c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6148c50d8ae3SPaolo Bonzini break; 6149c50d8ae3SPaolo Bonzini /* 6150c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6151c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6152c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6153c50d8ae3SPaolo Bonzini * anyway. 6154c50d8ae3SPaolo Bonzini */ 6155c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6156c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6157c50d8ae3SPaolo Bonzini continue; 6158c50d8ae3SPaolo Bonzini 6159c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6160531810caSBen Gardon write_lock(&kvm->mmu_lock); 6161c50d8ae3SPaolo Bonzini 6162c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6163c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6164c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6165c50d8ae3SPaolo Bonzini goto unlock; 6166c50d8ae3SPaolo Bonzini } 6167c50d8ae3SPaolo Bonzini 6168ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6169c50d8ae3SPaolo Bonzini 6170c50d8ae3SPaolo Bonzini unlock: 6171531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6172c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6173c50d8ae3SPaolo Bonzini 6174c50d8ae3SPaolo Bonzini /* 6175c50d8ae3SPaolo Bonzini * unfair on small ones 6176c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6177c50d8ae3SPaolo Bonzini * sadness comes quickly 6178c50d8ae3SPaolo Bonzini */ 6179c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6180c50d8ae3SPaolo Bonzini break; 6181c50d8ae3SPaolo Bonzini } 6182c50d8ae3SPaolo Bonzini 6183c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6184c50d8ae3SPaolo Bonzini return freed; 6185c50d8ae3SPaolo Bonzini } 6186c50d8ae3SPaolo Bonzini 6187c50d8ae3SPaolo Bonzini static unsigned long 6188c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6189c50d8ae3SPaolo Bonzini { 6190c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6191c50d8ae3SPaolo Bonzini } 6192c50d8ae3SPaolo Bonzini 6193c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6194c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6195c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6196c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6197c50d8ae3SPaolo Bonzini }; 6198c50d8ae3SPaolo Bonzini 6199c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6200c50d8ae3SPaolo Bonzini { 6201c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6202c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6203c50d8ae3SPaolo Bonzini } 6204c50d8ae3SPaolo Bonzini 6205c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6206c50d8ae3SPaolo Bonzini { 6207c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6208c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6209c50d8ae3SPaolo Bonzini } 6210c50d8ae3SPaolo Bonzini 6211c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6212c50d8ae3SPaolo Bonzini { 6213c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6214c50d8ae3SPaolo Bonzini } 6215c50d8ae3SPaolo Bonzini 6216c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6217c50d8ae3SPaolo Bonzini { 6218c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6219c50d8ae3SPaolo Bonzini bool new_val; 6220c50d8ae3SPaolo Bonzini 6221c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6222c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6223c50d8ae3SPaolo Bonzini new_val = 0; 6224c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6225c50d8ae3SPaolo Bonzini new_val = 1; 6226c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6227c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6228c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6229c50d8ae3SPaolo Bonzini return -EINVAL; 6230c50d8ae3SPaolo Bonzini 6231c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6232c50d8ae3SPaolo Bonzini 6233c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6234c50d8ae3SPaolo Bonzini struct kvm *kvm; 6235c50d8ae3SPaolo Bonzini 6236c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6237c50d8ae3SPaolo Bonzini 6238c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6239c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6240c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6241c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6242c50d8ae3SPaolo Bonzini 6243c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6244c50d8ae3SPaolo Bonzini } 6245c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6246c50d8ae3SPaolo Bonzini } 6247c50d8ae3SPaolo Bonzini 6248c50d8ae3SPaolo Bonzini return 0; 6249c50d8ae3SPaolo Bonzini } 6250c50d8ae3SPaolo Bonzini 62511d0e8480SSean Christopherson /* 62521d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 62531d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 62541d0e8480SSean Christopherson */ 62551d0e8480SSean Christopherson void kvm_mmu_x86_module_init(void) 6256c50d8ae3SPaolo Bonzini { 6257c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6258c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 62591d0e8480SSean Christopherson } 62601d0e8480SSean Christopherson 62611d0e8480SSean Christopherson /* 62621d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 62631d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 62641d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 62651d0e8480SSean Christopherson */ 62661d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 62671d0e8480SSean Christopherson { 62681d0e8480SSean Christopherson int ret = -ENOMEM; 6269c50d8ae3SPaolo Bonzini 6270c50d8ae3SPaolo Bonzini /* 6271c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6272c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6273c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6274c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6275c50d8ae3SPaolo Bonzini */ 6276c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6277c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 62787a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6279c50d8ae3SPaolo Bonzini 6280c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6281c50d8ae3SPaolo Bonzini 6282c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6283c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6284c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6285c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6286c50d8ae3SPaolo Bonzini goto out; 6287c50d8ae3SPaolo Bonzini 6288c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6289c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6290c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6291c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6292c50d8ae3SPaolo Bonzini goto out; 6293c50d8ae3SPaolo Bonzini 6294c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6295c50d8ae3SPaolo Bonzini goto out; 6296c50d8ae3SPaolo Bonzini 6297c50d8ae3SPaolo Bonzini ret = register_shrinker(&mmu_shrinker); 6298c50d8ae3SPaolo Bonzini if (ret) 6299c50d8ae3SPaolo Bonzini goto out; 6300c50d8ae3SPaolo Bonzini 6301c50d8ae3SPaolo Bonzini return 0; 6302c50d8ae3SPaolo Bonzini 6303c50d8ae3SPaolo Bonzini out: 6304c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6305c50d8ae3SPaolo Bonzini return ret; 6306c50d8ae3SPaolo Bonzini } 6307c50d8ae3SPaolo Bonzini 6308c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6309c50d8ae3SPaolo Bonzini { 6310c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6311c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6312c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6313c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6314c50d8ae3SPaolo Bonzini } 6315c50d8ae3SPaolo Bonzini 63161d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6317c50d8ae3SPaolo Bonzini { 6318c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6319c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6320c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6321c50d8ae3SPaolo Bonzini } 6322c50d8ae3SPaolo Bonzini 6323f47491d7SSean Christopherson /* 6324f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6325f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6326f47491d7SSean Christopherson */ 6327f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6328f47491d7SSean Christopherson { 6329f47491d7SSean Christopherson /* 6330f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6331f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6332f47491d7SSean Christopherson */ 6333f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6334f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6335f47491d7SSean Christopherson 6336f47491d7SSean Christopherson if (!enabled || !ratio) 6337f47491d7SSean Christopherson return false; 6338f47491d7SSean Christopherson 6339f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6340f47491d7SSean Christopherson if (!*period) { 6341f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6342f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6343f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6344f47491d7SSean Christopherson } 6345f47491d7SSean Christopherson return true; 6346f47491d7SSean Christopherson } 6347f47491d7SSean Christopherson 63484dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6349c50d8ae3SPaolo Bonzini { 63504dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 63514dfe4f40SJunaid Shahid uint old_period, new_period; 6352c50d8ae3SPaolo Bonzini int err; 6353c50d8ae3SPaolo Bonzini 6354f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 63554dfe4f40SJunaid Shahid 6356c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6357c50d8ae3SPaolo Bonzini if (err) 6358c50d8ae3SPaolo Bonzini return err; 6359c50d8ae3SPaolo Bonzini 6360f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 63614dfe4f40SJunaid Shahid 6362f47491d7SSean Christopherson if (is_recovery_enabled && 63634dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6364c50d8ae3SPaolo Bonzini struct kvm *kvm; 6365c50d8ae3SPaolo Bonzini 6366c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6367c50d8ae3SPaolo Bonzini 6368c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6369c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6370c50d8ae3SPaolo Bonzini 6371c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6372c50d8ae3SPaolo Bonzini } 6373c50d8ae3SPaolo Bonzini 6374c50d8ae3SPaolo Bonzini return err; 6375c50d8ae3SPaolo Bonzini } 6376c50d8ae3SPaolo Bonzini 6377c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6378c50d8ae3SPaolo Bonzini { 6379ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6380c50d8ae3SPaolo Bonzini int rcu_idx; 6381c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6382c50d8ae3SPaolo Bonzini unsigned int ratio; 6383c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6384048f4980SSean Christopherson bool flush = false; 6385c50d8ae3SPaolo Bonzini ulong to_zap; 6386c50d8ae3SPaolo Bonzini 6387c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6388531810caSBen Gardon write_lock(&kvm->mmu_lock); 6389c50d8ae3SPaolo Bonzini 6390bb95dfb9SSean Christopherson /* 6391bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6392bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6393bb95dfb9SSean Christopherson * callback. 6394bb95dfb9SSean Christopherson */ 6395bb95dfb9SSean Christopherson rcu_read_lock(); 6396bb95dfb9SSean Christopherson 6397c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6398ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 63997d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 64007d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 64017d919c7aSSean Christopherson break; 64027d919c7aSSean Christopherson 6403c50d8ae3SPaolo Bonzini /* 6404c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6405c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6406c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6407c50d8ae3SPaolo Bonzini */ 6408c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6409c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6410c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6411c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6412897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6413315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 64148d1a182eSBen Gardon } else { 6415c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6416c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 641729cf0f50SBen Gardon } 6418c50d8ae3SPaolo Bonzini 6419531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6420048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6421bb95dfb9SSean Christopherson rcu_read_unlock(); 6422bb95dfb9SSean Christopherson 6423531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6424048f4980SSean Christopherson flush = false; 6425bb95dfb9SSean Christopherson 6426bb95dfb9SSean Christopherson rcu_read_lock(); 6427c50d8ae3SPaolo Bonzini } 6428c50d8ae3SPaolo Bonzini } 6429048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6430c50d8ae3SPaolo Bonzini 6431bb95dfb9SSean Christopherson rcu_read_unlock(); 6432bb95dfb9SSean Christopherson 6433531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6434c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6435c50d8ae3SPaolo Bonzini } 6436c50d8ae3SPaolo Bonzini 6437c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6438c50d8ae3SPaolo Bonzini { 6439f47491d7SSean Christopherson bool enabled; 6440f47491d7SSean Christopherson uint period; 64414dfe4f40SJunaid Shahid 6442f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 64434dfe4f40SJunaid Shahid 6444f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6445c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6446c50d8ae3SPaolo Bonzini } 6447c50d8ae3SPaolo Bonzini 6448c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6449c50d8ae3SPaolo Bonzini { 6450c50d8ae3SPaolo Bonzini u64 start_time; 6451c50d8ae3SPaolo Bonzini long remaining_time; 6452c50d8ae3SPaolo Bonzini 6453c50d8ae3SPaolo Bonzini while (true) { 6454c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6455c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6456c50d8ae3SPaolo Bonzini 6457c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6458c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6459c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6460c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6461c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6462c50d8ae3SPaolo Bonzini } 6463c50d8ae3SPaolo Bonzini 6464c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6465c50d8ae3SPaolo Bonzini 6466c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6467c50d8ae3SPaolo Bonzini return 0; 6468c50d8ae3SPaolo Bonzini 6469c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6470c50d8ae3SPaolo Bonzini } 6471c50d8ae3SPaolo Bonzini } 6472c50d8ae3SPaolo Bonzini 6473c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6474c50d8ae3SPaolo Bonzini { 6475c50d8ae3SPaolo Bonzini int err; 6476c50d8ae3SPaolo Bonzini 6477c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6478c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6479c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6480c50d8ae3SPaolo Bonzini if (!err) 6481c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6482c50d8ae3SPaolo Bonzini 6483c50d8ae3SPaolo Bonzini return err; 6484c50d8ae3SPaolo Bonzini } 6485c50d8ae3SPaolo Bonzini 6486c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6487c50d8ae3SPaolo Bonzini { 6488c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6489c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6490c50d8ae3SPaolo Bonzini } 6491