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); 23460667724SSean Christopherson 235*faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 236*faf72962SPaolo Bonzini { 237*faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 238*faf72962SPaolo Bonzini } 239*faf72962SPaolo Bonzini 240*faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 241*faf72962SPaolo Bonzini { 242*faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 243*faf72962SPaolo Bonzini } 244*faf72962SPaolo Bonzini 245594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 246594e91a1SSean Christopherson { 247594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 248594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 249594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 250594e91a1SSean Christopherson .efer = vcpu->arch.efer, 251594e91a1SSean Christopherson }; 252594e91a1SSean Christopherson 253594e91a1SSean Christopherson return regs; 254594e91a1SSean Christopherson } 255c50d8ae3SPaolo Bonzini 256c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 257c50d8ae3SPaolo Bonzini { 258afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 259c50d8ae3SPaolo Bonzini } 260c50d8ae3SPaolo Bonzini 261c50d8ae3SPaolo Bonzini static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm, 262c50d8ae3SPaolo Bonzini struct kvm_tlb_range *range) 263c50d8ae3SPaolo Bonzini { 264c50d8ae3SPaolo Bonzini int ret = -ENOTSUPP; 265c50d8ae3SPaolo Bonzini 266afaf0b2fSSean Christopherson if (range && kvm_x86_ops.tlb_remote_flush_with_range) 267b3646477SJason Baron ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range); 268c50d8ae3SPaolo Bonzini 269c50d8ae3SPaolo Bonzini if (ret) 270c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 271c50d8ae3SPaolo Bonzini } 272c50d8ae3SPaolo Bonzini 2732f2fad08SBen Gardon void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 274c50d8ae3SPaolo Bonzini u64 start_gfn, u64 pages) 275c50d8ae3SPaolo Bonzini { 276c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 277c50d8ae3SPaolo Bonzini 278c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 279c50d8ae3SPaolo Bonzini range.pages = pages; 280c50d8ae3SPaolo Bonzini 281c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_range(kvm, &range); 282c50d8ae3SPaolo Bonzini } 283c50d8ae3SPaolo Bonzini 2848f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2858f79b064SBen Gardon unsigned int access) 2868f79b064SBen Gardon { 287c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2888f79b064SBen Gardon 289c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 290c236d962SSean Christopherson mmu_spte_set(sptep, spte); 291c50d8ae3SPaolo Bonzini } 292c50d8ae3SPaolo Bonzini 293c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 294c50d8ae3SPaolo Bonzini { 295c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 296c50d8ae3SPaolo Bonzini 2978a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 298c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 299c50d8ae3SPaolo Bonzini 300c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 301c50d8ae3SPaolo Bonzini } 302c50d8ae3SPaolo Bonzini 303c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 304c50d8ae3SPaolo Bonzini { 305c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 306c50d8ae3SPaolo Bonzini } 307c50d8ae3SPaolo Bonzini 308c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 309c50d8ae3SPaolo Bonzini { 310c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 311c50d8ae3SPaolo Bonzini 312c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 313c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 314c50d8ae3SPaolo Bonzini return false; 315c50d8ae3SPaolo Bonzini 316c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 317c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 318c50d8ae3SPaolo Bonzini 319c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 320c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 321c50d8ae3SPaolo Bonzini } 322c50d8ae3SPaolo Bonzini 323c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 324c50d8ae3SPaolo Bonzini { 325c50d8ae3SPaolo Bonzini return 1; 326c50d8ae3SPaolo Bonzini } 327c50d8ae3SPaolo Bonzini 328c50d8ae3SPaolo Bonzini static gfn_t pse36_gfn_delta(u32 gpte) 329c50d8ae3SPaolo Bonzini { 330c50d8ae3SPaolo Bonzini int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT; 331c50d8ae3SPaolo Bonzini 332c50d8ae3SPaolo Bonzini return (gpte & PT32_DIR_PSE36_MASK) << shift; 333c50d8ae3SPaolo Bonzini } 334c50d8ae3SPaolo Bonzini 335c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 336c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 337c50d8ae3SPaolo Bonzini { 338c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 339c50d8ae3SPaolo Bonzini } 340c50d8ae3SPaolo Bonzini 341c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 342c50d8ae3SPaolo Bonzini { 343c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 344c50d8ae3SPaolo Bonzini } 345c50d8ae3SPaolo Bonzini 346c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 347c50d8ae3SPaolo Bonzini { 348c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 349c50d8ae3SPaolo Bonzini } 350c50d8ae3SPaolo Bonzini 351c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 352c50d8ae3SPaolo Bonzini { 353c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 354c50d8ae3SPaolo Bonzini } 355c50d8ae3SPaolo Bonzini #else 356c50d8ae3SPaolo Bonzini union split_spte { 357c50d8ae3SPaolo Bonzini struct { 358c50d8ae3SPaolo Bonzini u32 spte_low; 359c50d8ae3SPaolo Bonzini u32 spte_high; 360c50d8ae3SPaolo Bonzini }; 361c50d8ae3SPaolo Bonzini u64 spte; 362c50d8ae3SPaolo Bonzini }; 363c50d8ae3SPaolo Bonzini 364c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 365c50d8ae3SPaolo Bonzini { 36657354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 367c50d8ae3SPaolo Bonzini 368c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 369c50d8ae3SPaolo Bonzini return; 370c50d8ae3SPaolo Bonzini 371c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 372c50d8ae3SPaolo Bonzini smp_wmb(); 373c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 374c50d8ae3SPaolo Bonzini } 375c50d8ae3SPaolo Bonzini 376c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 377c50d8ae3SPaolo Bonzini { 378c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 379c50d8ae3SPaolo Bonzini 380c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 381c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 382c50d8ae3SPaolo Bonzini 383c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 384c50d8ae3SPaolo Bonzini 385c50d8ae3SPaolo Bonzini /* 386c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 387c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 388c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 389c50d8ae3SPaolo Bonzini */ 390c50d8ae3SPaolo Bonzini smp_wmb(); 391c50d8ae3SPaolo Bonzini 392c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 393c50d8ae3SPaolo Bonzini } 394c50d8ae3SPaolo Bonzini 395c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 396c50d8ae3SPaolo Bonzini { 397c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 398c50d8ae3SPaolo Bonzini 399c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 400c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 401c50d8ae3SPaolo Bonzini 402c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 403c50d8ae3SPaolo Bonzini 404c50d8ae3SPaolo Bonzini /* 405c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 406c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 407c50d8ae3SPaolo Bonzini */ 408c50d8ae3SPaolo Bonzini smp_wmb(); 409c50d8ae3SPaolo Bonzini 410c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 411c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 412c50d8ae3SPaolo Bonzini } 413c50d8ae3SPaolo Bonzini 414c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 415c50d8ae3SPaolo Bonzini { 416c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 417c50d8ae3SPaolo Bonzini 418c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 419c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 420c50d8ae3SPaolo Bonzini 421c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 422c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 423c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 424c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 425c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 426c50d8ae3SPaolo Bonzini 427c50d8ae3SPaolo Bonzini return orig.spte; 428c50d8ae3SPaolo Bonzini } 429c50d8ae3SPaolo Bonzini 430c50d8ae3SPaolo Bonzini /* 431c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 432c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 433c50d8ae3SPaolo Bonzini * 434c50d8ae3SPaolo Bonzini * An spte tlb flush may be pending, because kvm_set_pte_rmapp 435c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 436c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 437c50d8ae3SPaolo Bonzini * 438c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 439c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 440c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 441c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 442c50d8ae3SPaolo Bonzini * 443c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 444c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 445c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 446c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 447c50d8ae3SPaolo Bonzini */ 448c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 449c50d8ae3SPaolo Bonzini { 45057354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 451c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 452c50d8ae3SPaolo Bonzini int count; 453c50d8ae3SPaolo Bonzini 454c50d8ae3SPaolo Bonzini retry: 455c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 456c50d8ae3SPaolo Bonzini smp_rmb(); 457c50d8ae3SPaolo Bonzini 458c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 459c50d8ae3SPaolo Bonzini smp_rmb(); 460c50d8ae3SPaolo Bonzini 461c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 462c50d8ae3SPaolo Bonzini smp_rmb(); 463c50d8ae3SPaolo Bonzini 464c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 465c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 466c50d8ae3SPaolo Bonzini goto retry; 467c50d8ae3SPaolo Bonzini 468c50d8ae3SPaolo Bonzini return spte.spte; 469c50d8ae3SPaolo Bonzini } 470c50d8ae3SPaolo Bonzini #endif 471c50d8ae3SPaolo Bonzini 472c50d8ae3SPaolo Bonzini static bool spte_has_volatile_bits(u64 spte) 473c50d8ae3SPaolo Bonzini { 474c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(spte)) 475c50d8ae3SPaolo Bonzini return false; 476c50d8ae3SPaolo Bonzini 477c50d8ae3SPaolo Bonzini /* 478c50d8ae3SPaolo Bonzini * Always atomically update spte if it can be updated 479c50d8ae3SPaolo Bonzini * out of mmu-lock, it can ensure dirty bit is not lost, 480c50d8ae3SPaolo Bonzini * also, it can help us to get a stable is_writable_pte() 481c50d8ae3SPaolo Bonzini * to ensure tlb flush is not missed. 482c50d8ae3SPaolo Bonzini */ 483c50d8ae3SPaolo Bonzini if (spte_can_locklessly_be_made_writable(spte) || 484c50d8ae3SPaolo Bonzini is_access_track_spte(spte)) 485c50d8ae3SPaolo Bonzini return true; 486c50d8ae3SPaolo Bonzini 487c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 488c50d8ae3SPaolo Bonzini if ((spte & shadow_accessed_mask) == 0 || 489c50d8ae3SPaolo Bonzini (is_writable_pte(spte) && (spte & shadow_dirty_mask) == 0)) 490c50d8ae3SPaolo Bonzini return true; 491c50d8ae3SPaolo Bonzini } 492c50d8ae3SPaolo Bonzini 493c50d8ae3SPaolo Bonzini return false; 494c50d8ae3SPaolo Bonzini } 495c50d8ae3SPaolo Bonzini 496c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 497c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 498c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 499c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 500c50d8ae3SPaolo Bonzini * the spte. 501c50d8ae3SPaolo Bonzini */ 502c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 503c50d8ae3SPaolo Bonzini { 504c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 505c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 506c50d8ae3SPaolo Bonzini } 507c50d8ae3SPaolo Bonzini 508c50d8ae3SPaolo Bonzini /* 509c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 510c50d8ae3SPaolo Bonzini * accessed/dirty status. 511c50d8ae3SPaolo Bonzini */ 512c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 513c50d8ae3SPaolo Bonzini { 514c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 515c50d8ae3SPaolo Bonzini 516c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 517115111efSDavid Matlack check_spte_writable_invariants(new_spte); 518c50d8ae3SPaolo Bonzini 519c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 520c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 521c50d8ae3SPaolo Bonzini return old_spte; 522c50d8ae3SPaolo Bonzini } 523c50d8ae3SPaolo Bonzini 524c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 525c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 526c50d8ae3SPaolo Bonzini else 527c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 528c50d8ae3SPaolo Bonzini 529c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 530c50d8ae3SPaolo Bonzini 531c50d8ae3SPaolo Bonzini return old_spte; 532c50d8ae3SPaolo Bonzini } 533c50d8ae3SPaolo Bonzini 534c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 535c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 536c50d8ae3SPaolo Bonzini * 53702844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 53802844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 53902844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 540c50d8ae3SPaolo Bonzini * 541c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 542c50d8ae3SPaolo Bonzini */ 543c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 544c50d8ae3SPaolo Bonzini { 545c50d8ae3SPaolo Bonzini bool flush = false; 546c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 547c50d8ae3SPaolo Bonzini 548c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 549c50d8ae3SPaolo Bonzini return false; 550c50d8ae3SPaolo Bonzini 551c50d8ae3SPaolo Bonzini /* 552c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 553c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 554c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 555c50d8ae3SPaolo Bonzini */ 556c50d8ae3SPaolo Bonzini if (spte_can_locklessly_be_made_writable(old_spte) && 557c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 558c50d8ae3SPaolo Bonzini flush = true; 559c50d8ae3SPaolo Bonzini 560c50d8ae3SPaolo Bonzini /* 561c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 562c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 563c50d8ae3SPaolo Bonzini */ 564c50d8ae3SPaolo Bonzini 565c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 566c50d8ae3SPaolo Bonzini flush = true; 567c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 568c50d8ae3SPaolo Bonzini } 569c50d8ae3SPaolo Bonzini 570c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 571c50d8ae3SPaolo Bonzini flush = true; 572c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 573c50d8ae3SPaolo Bonzini } 574c50d8ae3SPaolo Bonzini 575c50d8ae3SPaolo Bonzini return flush; 576c50d8ae3SPaolo Bonzini } 577c50d8ae3SPaolo Bonzini 578c50d8ae3SPaolo Bonzini /* 579c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 580c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 581c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5827fa2a347SSean Christopherson * Returns the old PTE. 583c50d8ae3SPaolo Bonzini */ 58471f51d2cSMingwei Zhang static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 585c50d8ae3SPaolo Bonzini { 586c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 587c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 58871f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 589c50d8ae3SPaolo Bonzini 590c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 591c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 592c50d8ae3SPaolo Bonzini else 593c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 594c50d8ae3SPaolo Bonzini 595c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5967fa2a347SSean Christopherson return old_spte; 597c50d8ae3SPaolo Bonzini 59871f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 59971f51d2cSMingwei Zhang 600c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 601c50d8ae3SPaolo Bonzini 602c50d8ae3SPaolo Bonzini /* 603c50d8ae3SPaolo Bonzini * KVM does not hold the refcount of the page used by 604c50d8ae3SPaolo Bonzini * kvm mmu, before reclaiming the page, we should 605c50d8ae3SPaolo Bonzini * unmap it from mmu first. 606c50d8ae3SPaolo Bonzini */ 607c50d8ae3SPaolo Bonzini WARN_ON(!kvm_is_reserved_pfn(pfn) && !page_count(pfn_to_page(pfn))); 608c50d8ae3SPaolo Bonzini 609c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 610c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 611c50d8ae3SPaolo Bonzini 612c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 613c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 614c50d8ae3SPaolo Bonzini 6157fa2a347SSean Christopherson return old_spte; 616c50d8ae3SPaolo Bonzini } 617c50d8ae3SPaolo Bonzini 618c50d8ae3SPaolo Bonzini /* 619c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 620c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 621c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 622c50d8ae3SPaolo Bonzini */ 623c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 624c50d8ae3SPaolo Bonzini { 625c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 626c50d8ae3SPaolo Bonzini } 627c50d8ae3SPaolo Bonzini 628c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 629c50d8ae3SPaolo Bonzini { 630c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 631c50d8ae3SPaolo Bonzini } 632c50d8ae3SPaolo Bonzini 633c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 634c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 635c50d8ae3SPaolo Bonzini { 636c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 637c50d8ae3SPaolo Bonzini 638c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 639c50d8ae3SPaolo Bonzini return false; 640c50d8ae3SPaolo Bonzini 641c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 642c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 643c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 644c50d8ae3SPaolo Bonzini } else { 645c50d8ae3SPaolo Bonzini /* 646c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 647c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 648c50d8ae3SPaolo Bonzini */ 649c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 650c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 651c50d8ae3SPaolo Bonzini 652c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 653c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 654c50d8ae3SPaolo Bonzini } 655c50d8ae3SPaolo Bonzini 656c50d8ae3SPaolo Bonzini return true; 657c50d8ae3SPaolo Bonzini } 658c50d8ae3SPaolo Bonzini 659c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 660c50d8ae3SPaolo Bonzini { 661c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 662c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 663c5c8c7c5SDavid Matlack } else { 664c50d8ae3SPaolo Bonzini /* 665c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 666c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 667c50d8ae3SPaolo Bonzini */ 668c50d8ae3SPaolo Bonzini local_irq_disable(); 669c50d8ae3SPaolo Bonzini 670c50d8ae3SPaolo Bonzini /* 671c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 672c50d8ae3SPaolo Bonzini * to vcpu->mode. 673c50d8ae3SPaolo Bonzini */ 674c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 675c50d8ae3SPaolo Bonzini } 676c5c8c7c5SDavid Matlack } 677c50d8ae3SPaolo Bonzini 678c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 679c50d8ae3SPaolo Bonzini { 680c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 681c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 682c5c8c7c5SDavid Matlack } else { 683c50d8ae3SPaolo Bonzini /* 684c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 685c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 686c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 687c50d8ae3SPaolo Bonzini */ 688c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 689c50d8ae3SPaolo Bonzini local_irq_enable(); 690c50d8ae3SPaolo Bonzini } 691c5c8c7c5SDavid Matlack } 692c50d8ae3SPaolo Bonzini 693378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 694c50d8ae3SPaolo Bonzini { 695c50d8ae3SPaolo Bonzini int r; 696c50d8ae3SPaolo Bonzini 697531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 69894ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 699531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 700c50d8ae3SPaolo Bonzini if (r) 701c50d8ae3SPaolo Bonzini return r; 70294ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 703171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 704171a90d7SSean Christopherson if (r) 705171a90d7SSean Christopherson return r; 706378f5cd6SSean Christopherson if (maybe_indirect) { 70794ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_cache, 708171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 709c50d8ae3SPaolo Bonzini if (r) 710c50d8ae3SPaolo Bonzini return r; 711378f5cd6SSean Christopherson } 71294ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 713531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 714c50d8ae3SPaolo Bonzini } 715c50d8ae3SPaolo Bonzini 716c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 717c50d8ae3SPaolo Bonzini { 71894ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 71994ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 72094ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_gfn_array_cache); 72194ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 722c50d8ae3SPaolo Bonzini } 723c50d8ae3SPaolo Bonzini 724c50d8ae3SPaolo Bonzini static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu) 725c50d8ae3SPaolo Bonzini { 72694ce87efSSean Christopherson return kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_list_desc_cache); 727c50d8ae3SPaolo Bonzini } 728c50d8ae3SPaolo Bonzini 729c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 730c50d8ae3SPaolo Bonzini { 731c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 732c50d8ae3SPaolo Bonzini } 733c50d8ae3SPaolo Bonzini 734c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 735c50d8ae3SPaolo Bonzini { 736c50d8ae3SPaolo Bonzini if (!sp->role.direct) 737c50d8ae3SPaolo Bonzini return sp->gfns[index]; 738c50d8ae3SPaolo Bonzini 739c50d8ae3SPaolo Bonzini return sp->gfn + (index << ((sp->role.level - 1) * PT64_LEVEL_BITS)); 740c50d8ae3SPaolo Bonzini } 741c50d8ae3SPaolo Bonzini 742c50d8ae3SPaolo Bonzini static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn) 743c50d8ae3SPaolo Bonzini { 744c50d8ae3SPaolo Bonzini if (!sp->role.direct) { 745c50d8ae3SPaolo Bonzini sp->gfns[index] = gfn; 746c50d8ae3SPaolo Bonzini return; 747c50d8ae3SPaolo Bonzini } 748c50d8ae3SPaolo Bonzini 749c50d8ae3SPaolo Bonzini if (WARN_ON(gfn != kvm_mmu_page_get_gfn(sp, index))) 750c50d8ae3SPaolo Bonzini pr_err_ratelimited("gfn mismatch under direct page %llx " 751c50d8ae3SPaolo Bonzini "(expected %llx, got %llx)\n", 752c50d8ae3SPaolo Bonzini sp->gfn, 753c50d8ae3SPaolo Bonzini kvm_mmu_page_get_gfn(sp, index), gfn); 754c50d8ae3SPaolo Bonzini } 755c50d8ae3SPaolo Bonzini 756c50d8ae3SPaolo Bonzini /* 757c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 758c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 759c50d8ae3SPaolo Bonzini */ 760c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7618ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 762c50d8ae3SPaolo Bonzini { 763c50d8ae3SPaolo Bonzini unsigned long idx; 764c50d8ae3SPaolo Bonzini 765c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 766c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 767c50d8ae3SPaolo Bonzini } 768c50d8ae3SPaolo Bonzini 769269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 770c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 771c50d8ae3SPaolo Bonzini { 772c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 773c50d8ae3SPaolo Bonzini int i; 774c50d8ae3SPaolo Bonzini 7753bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 776c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 777c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 778c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 779c50d8ae3SPaolo Bonzini } 780c50d8ae3SPaolo Bonzini } 781c50d8ae3SPaolo Bonzini 782269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 783c50d8ae3SPaolo Bonzini { 784c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 785c50d8ae3SPaolo Bonzini } 786c50d8ae3SPaolo Bonzini 787269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 788c50d8ae3SPaolo Bonzini { 789c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 790c50d8ae3SPaolo Bonzini } 791c50d8ae3SPaolo Bonzini 792c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 793c50d8ae3SPaolo Bonzini { 794c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 795c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 796c50d8ae3SPaolo Bonzini gfn_t gfn; 797c50d8ae3SPaolo Bonzini 798c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 799c50d8ae3SPaolo Bonzini gfn = sp->gfn; 800c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 801c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 802c50d8ae3SPaolo Bonzini 803c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8043bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 805c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 806c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 807c50d8ae3SPaolo Bonzini 808c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 809c50d8ae3SPaolo Bonzini } 810c50d8ae3SPaolo Bonzini 81129cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 812c50d8ae3SPaolo Bonzini { 813c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 814c50d8ae3SPaolo Bonzini return; 815c50d8ae3SPaolo Bonzini 816c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 817c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 818c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 819c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 820c50d8ae3SPaolo Bonzini } 821c50d8ae3SPaolo Bonzini 822c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 823c50d8ae3SPaolo Bonzini { 824c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 825c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 826c50d8ae3SPaolo Bonzini gfn_t gfn; 827c50d8ae3SPaolo Bonzini 828c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 829c50d8ae3SPaolo Bonzini gfn = sp->gfn; 830c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 831c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8323bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 833c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 834c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 835c50d8ae3SPaolo Bonzini 836c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 837c50d8ae3SPaolo Bonzini } 838c50d8ae3SPaolo Bonzini 83929cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 840c50d8ae3SPaolo Bonzini { 841c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 842c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 843c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 844c50d8ae3SPaolo Bonzini } 845c50d8ae3SPaolo Bonzini 846c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 847c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 848c50d8ae3SPaolo Bonzini bool no_dirty_log) 849c50d8ae3SPaolo Bonzini { 850c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 851c50d8ae3SPaolo Bonzini 852c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 85391b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 85491b0d268SPaolo Bonzini return NULL; 855044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 85691b0d268SPaolo Bonzini return NULL; 857c50d8ae3SPaolo Bonzini 858c50d8ae3SPaolo Bonzini return slot; 859c50d8ae3SPaolo Bonzini } 860c50d8ae3SPaolo Bonzini 861c50d8ae3SPaolo Bonzini /* 862c50d8ae3SPaolo Bonzini * About rmap_head encoding: 863c50d8ae3SPaolo Bonzini * 864c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 865c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 866c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 867c50d8ae3SPaolo Bonzini */ 868c50d8ae3SPaolo Bonzini 869c50d8ae3SPaolo Bonzini /* 870c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 871c50d8ae3SPaolo Bonzini */ 872c50d8ae3SPaolo Bonzini static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte, 873c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 874c50d8ae3SPaolo Bonzini { 875c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 87613236e25SPeter Xu int count = 0; 877c50d8ae3SPaolo Bonzini 878c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 879805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 880c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 881c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 882805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 883c50d8ae3SPaolo Bonzini desc = mmu_alloc_pte_list_desc(vcpu); 884c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 885c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 88613236e25SPeter Xu desc->spte_count = 2; 887c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 888c50d8ae3SPaolo Bonzini ++count; 889c50d8ae3SPaolo Bonzini } else { 890805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 891c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 89213236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 893c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 894c6c4f961SLi RongQing if (!desc->more) { 895c50d8ae3SPaolo Bonzini desc->more = mmu_alloc_pte_list_desc(vcpu); 896c50d8ae3SPaolo Bonzini desc = desc->more; 89713236e25SPeter Xu desc->spte_count = 0; 898c6c4f961SLi RongQing break; 899c6c4f961SLi RongQing } 900c6c4f961SLi RongQing desc = desc->more; 901c50d8ae3SPaolo Bonzini } 90213236e25SPeter Xu count += desc->spte_count; 90313236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 904c50d8ae3SPaolo Bonzini } 905c50d8ae3SPaolo Bonzini return count; 906c50d8ae3SPaolo Bonzini } 907c50d8ae3SPaolo Bonzini 908c50d8ae3SPaolo Bonzini static void 909c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 910c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 911c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 912c50d8ae3SPaolo Bonzini { 91313236e25SPeter Xu int j = desc->spte_count - 1; 914c50d8ae3SPaolo Bonzini 915c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 916c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 91713236e25SPeter Xu desc->spte_count--; 91813236e25SPeter Xu if (desc->spte_count) 919c50d8ae3SPaolo Bonzini return; 920c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 921fe3c2b4cSMiaohe Lin rmap_head->val = 0; 922c50d8ae3SPaolo Bonzini else 923c50d8ae3SPaolo Bonzini if (prev_desc) 924c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 925c50d8ae3SPaolo Bonzini else 926c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 927c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 928c50d8ae3SPaolo Bonzini } 929c50d8ae3SPaolo Bonzini 930c50d8ae3SPaolo Bonzini static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 931c50d8ae3SPaolo Bonzini { 932c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 933c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 934c50d8ae3SPaolo Bonzini int i; 935c50d8ae3SPaolo Bonzini 936c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 937c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 938c50d8ae3SPaolo Bonzini BUG(); 939c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 940805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 941c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 942c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 943c50d8ae3SPaolo Bonzini BUG(); 944c50d8ae3SPaolo Bonzini } 945c50d8ae3SPaolo Bonzini rmap_head->val = 0; 946c50d8ae3SPaolo Bonzini } else { 947805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 948c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 949c50d8ae3SPaolo Bonzini prev_desc = NULL; 950c50d8ae3SPaolo Bonzini while (desc) { 95113236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 952c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 953c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 954c50d8ae3SPaolo Bonzini desc, i, prev_desc); 955c50d8ae3SPaolo Bonzini return; 956c50d8ae3SPaolo Bonzini } 957c50d8ae3SPaolo Bonzini } 958c50d8ae3SPaolo Bonzini prev_desc = desc; 959c50d8ae3SPaolo Bonzini desc = desc->more; 960c50d8ae3SPaolo Bonzini } 961c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 962c50d8ae3SPaolo Bonzini BUG(); 963c50d8ae3SPaolo Bonzini } 964c50d8ae3SPaolo Bonzini } 965c50d8ae3SPaolo Bonzini 96671f51d2cSMingwei Zhang static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 96771f51d2cSMingwei Zhang u64 *sptep) 968c50d8ae3SPaolo Bonzini { 96971f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 970c50d8ae3SPaolo Bonzini __pte_list_remove(sptep, rmap_head); 971c50d8ae3SPaolo Bonzini } 972c50d8ae3SPaolo Bonzini 973a75b5404SPeter Xu /* Return true if rmap existed, false otherwise */ 97471f51d2cSMingwei Zhang static bool pte_list_destroy(struct kvm *kvm, struct kvm_rmap_head *rmap_head) 975a75b5404SPeter Xu { 976a75b5404SPeter Xu struct pte_list_desc *desc, *next; 977a75b5404SPeter Xu int i; 978a75b5404SPeter Xu 979a75b5404SPeter Xu if (!rmap_head->val) 980a75b5404SPeter Xu return false; 981a75b5404SPeter Xu 982a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 98371f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 984a75b5404SPeter Xu goto out; 985a75b5404SPeter Xu } 986a75b5404SPeter Xu 987a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 988a75b5404SPeter Xu 989a75b5404SPeter Xu for (; desc; desc = next) { 990a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 99171f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 992a75b5404SPeter Xu next = desc->more; 993a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 994a75b5404SPeter Xu } 995a75b5404SPeter Xu out: 996a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 997a75b5404SPeter Xu rmap_head->val = 0; 998a75b5404SPeter Xu return true; 999a75b5404SPeter Xu } 1000a75b5404SPeter Xu 10013bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10023bcd0662SPeter Xu { 10033bcd0662SPeter Xu struct pte_list_desc *desc; 10043bcd0662SPeter Xu unsigned int count = 0; 10053bcd0662SPeter Xu 10063bcd0662SPeter Xu if (!rmap_head->val) 10073bcd0662SPeter Xu return 0; 10083bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10093bcd0662SPeter Xu return 1; 10103bcd0662SPeter Xu 10113bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10123bcd0662SPeter Xu 10133bcd0662SPeter Xu while (desc) { 10143bcd0662SPeter Xu count += desc->spte_count; 10153bcd0662SPeter Xu desc = desc->more; 10163bcd0662SPeter Xu } 10173bcd0662SPeter Xu 10183bcd0662SPeter Xu return count; 10193bcd0662SPeter Xu } 10203bcd0662SPeter Xu 102193e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1022269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1023c50d8ae3SPaolo Bonzini { 1024c50d8ae3SPaolo Bonzini unsigned long idx; 1025c50d8ae3SPaolo Bonzini 1026c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10273bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1028c50d8ae3SPaolo Bonzini } 1029c50d8ae3SPaolo Bonzini 1030c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1031c50d8ae3SPaolo Bonzini { 1032356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1033c50d8ae3SPaolo Bonzini 1034356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 103594ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1036c50d8ae3SPaolo Bonzini } 1037c50d8ae3SPaolo Bonzini 1038c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1039c50d8ae3SPaolo Bonzini { 1040601f8af0SDavid Matlack struct kvm_memslots *slots; 1041601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1042c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1043c50d8ae3SPaolo Bonzini gfn_t gfn; 1044c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1045c50d8ae3SPaolo Bonzini 104657354682SSean Christopherson sp = sptep_to_sp(spte); 1047c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt); 1048601f8af0SDavid Matlack 1049601f8af0SDavid Matlack /* 105068be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 105168be1306SDavid Matlack * so we have to determine which memslots to use based on context 105268be1306SDavid Matlack * information in sp->role. 1053601f8af0SDavid Matlack */ 1054601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1055601f8af0SDavid Matlack 1056601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 105793e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1058601f8af0SDavid Matlack 1059c50d8ae3SPaolo Bonzini __pte_list_remove(spte, rmap_head); 1060c50d8ae3SPaolo Bonzini } 1061c50d8ae3SPaolo Bonzini 1062c50d8ae3SPaolo Bonzini /* 1063c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1064c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1065c50d8ae3SPaolo Bonzini */ 1066c50d8ae3SPaolo Bonzini struct rmap_iterator { 1067c50d8ae3SPaolo Bonzini /* private fields */ 1068c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1069c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1070c50d8ae3SPaolo Bonzini }; 1071c50d8ae3SPaolo Bonzini 1072c50d8ae3SPaolo Bonzini /* 1073c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1074c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10750a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1076c50d8ae3SPaolo Bonzini * 1077c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1078c50d8ae3SPaolo Bonzini */ 1079c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1080c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1081c50d8ae3SPaolo Bonzini { 1082c50d8ae3SPaolo Bonzini u64 *sptep; 1083c50d8ae3SPaolo Bonzini 1084c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1085c50d8ae3SPaolo Bonzini return NULL; 1086c50d8ae3SPaolo Bonzini 1087c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1088c50d8ae3SPaolo Bonzini iter->desc = NULL; 1089c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1090c50d8ae3SPaolo Bonzini goto out; 1091c50d8ae3SPaolo Bonzini } 1092c50d8ae3SPaolo Bonzini 1093c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1094c50d8ae3SPaolo Bonzini iter->pos = 0; 1095c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1096c50d8ae3SPaolo Bonzini out: 1097c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1098c50d8ae3SPaolo Bonzini return sptep; 1099c50d8ae3SPaolo Bonzini } 1100c50d8ae3SPaolo Bonzini 1101c50d8ae3SPaolo Bonzini /* 1102c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1103c50d8ae3SPaolo Bonzini * 1104c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1105c50d8ae3SPaolo Bonzini */ 1106c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1107c50d8ae3SPaolo Bonzini { 1108c50d8ae3SPaolo Bonzini u64 *sptep; 1109c50d8ae3SPaolo Bonzini 1110c50d8ae3SPaolo Bonzini if (iter->desc) { 1111c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1112c50d8ae3SPaolo Bonzini ++iter->pos; 1113c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1114c50d8ae3SPaolo Bonzini if (sptep) 1115c50d8ae3SPaolo Bonzini goto out; 1116c50d8ae3SPaolo Bonzini } 1117c50d8ae3SPaolo Bonzini 1118c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1119c50d8ae3SPaolo Bonzini 1120c50d8ae3SPaolo Bonzini if (iter->desc) { 1121c50d8ae3SPaolo Bonzini iter->pos = 0; 1122c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1123c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1124c50d8ae3SPaolo Bonzini goto out; 1125c50d8ae3SPaolo Bonzini } 1126c50d8ae3SPaolo Bonzini } 1127c50d8ae3SPaolo Bonzini 1128c50d8ae3SPaolo Bonzini return NULL; 1129c50d8ae3SPaolo Bonzini out: 1130c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1131c50d8ae3SPaolo Bonzini return sptep; 1132c50d8ae3SPaolo Bonzini } 1133c50d8ae3SPaolo Bonzini 1134c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1135c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1136c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1137c50d8ae3SPaolo Bonzini 1138c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1139c50d8ae3SPaolo Bonzini { 114071f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11417fa2a347SSean Christopherson 11427fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1143c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1144c50d8ae3SPaolo Bonzini } 1145c50d8ae3SPaolo Bonzini 1146c50d8ae3SPaolo Bonzini 1147c50d8ae3SPaolo Bonzini static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) 1148c50d8ae3SPaolo Bonzini { 1149c50d8ae3SPaolo Bonzini if (is_large_pte(*sptep)) { 115057354682SSean Christopherson WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); 1151c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 1152c50d8ae3SPaolo Bonzini return true; 1153c50d8ae3SPaolo Bonzini } 1154c50d8ae3SPaolo Bonzini 1155c50d8ae3SPaolo Bonzini return false; 1156c50d8ae3SPaolo Bonzini } 1157c50d8ae3SPaolo Bonzini 1158c50d8ae3SPaolo Bonzini static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) 1159c50d8ae3SPaolo Bonzini { 1160c50d8ae3SPaolo Bonzini if (__drop_large_spte(vcpu->kvm, sptep)) { 116157354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 1162c50d8ae3SPaolo Bonzini 1163c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, 1164c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1165c50d8ae3SPaolo Bonzini } 1166c50d8ae3SPaolo Bonzini } 1167c50d8ae3SPaolo Bonzini 1168c50d8ae3SPaolo Bonzini /* 1169c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1170c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1171c50d8ae3SPaolo Bonzini * 1172c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1173c50d8ae3SPaolo Bonzini * protection: 1174c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1175c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1176c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1177c50d8ae3SPaolo Bonzini * shadow page. 1178c50d8ae3SPaolo Bonzini * 1179c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1180c50d8ae3SPaolo Bonzini */ 1181c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1182c50d8ae3SPaolo Bonzini { 1183c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1184c50d8ae3SPaolo Bonzini 1185c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1186c50d8ae3SPaolo Bonzini !(pt_protect && spte_can_locklessly_be_made_writable(spte))) 1187c50d8ae3SPaolo Bonzini return false; 1188c50d8ae3SPaolo Bonzini 1189805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1190c50d8ae3SPaolo Bonzini 1191c50d8ae3SPaolo Bonzini if (pt_protect) 11925fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1193c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1194c50d8ae3SPaolo Bonzini 1195c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1196c50d8ae3SPaolo Bonzini } 1197c50d8ae3SPaolo Bonzini 11981346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1199c50d8ae3SPaolo Bonzini bool pt_protect) 1200c50d8ae3SPaolo Bonzini { 1201c50d8ae3SPaolo Bonzini u64 *sptep; 1202c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1203c50d8ae3SPaolo Bonzini bool flush = false; 1204c50d8ae3SPaolo Bonzini 1205c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1206c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1207c50d8ae3SPaolo Bonzini 1208c50d8ae3SPaolo Bonzini return flush; 1209c50d8ae3SPaolo Bonzini } 1210c50d8ae3SPaolo Bonzini 1211c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1212c50d8ae3SPaolo Bonzini { 1213c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1214c50d8ae3SPaolo Bonzini 1215805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1216c50d8ae3SPaolo Bonzini 1217c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1218c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1219c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1220c50d8ae3SPaolo Bonzini } 1221c50d8ae3SPaolo Bonzini 1222c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1223c50d8ae3SPaolo Bonzini { 1224c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1225c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1226c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1227c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1228c50d8ae3SPaolo Bonzini 1229c50d8ae3SPaolo Bonzini return was_writable; 1230c50d8ae3SPaolo Bonzini } 1231c50d8ae3SPaolo Bonzini 1232c50d8ae3SPaolo Bonzini /* 1233c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1234c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1235c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1236c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1237c50d8ae3SPaolo Bonzini */ 12380a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1239269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1240c50d8ae3SPaolo Bonzini { 1241c50d8ae3SPaolo Bonzini u64 *sptep; 1242c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1243c50d8ae3SPaolo Bonzini bool flush = false; 1244c50d8ae3SPaolo Bonzini 1245c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1246c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1247c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1248c50d8ae3SPaolo Bonzini else 1249c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1250c50d8ae3SPaolo Bonzini 1251c50d8ae3SPaolo Bonzini return flush; 1252c50d8ae3SPaolo Bonzini } 1253c50d8ae3SPaolo Bonzini 1254c50d8ae3SPaolo Bonzini /** 1255c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1256c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1257c50d8ae3SPaolo Bonzini * @slot: slot to protect 1258c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1259c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1260c50d8ae3SPaolo Bonzini * 126189212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1262c50d8ae3SPaolo Bonzini */ 1263c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1264c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1265c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1266c50d8ae3SPaolo Bonzini { 1267c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1268c50d8ae3SPaolo Bonzini 1269897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1270a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1271a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1272e2209710SBen Gardon 1273e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1274e2209710SBen Gardon return; 1275e2209710SBen Gardon 1276c50d8ae3SPaolo Bonzini while (mask) { 127793e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12783bae0459SSean Christopherson PG_LEVEL_4K, slot); 12791346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1280c50d8ae3SPaolo Bonzini 1281c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1282c50d8ae3SPaolo Bonzini mask &= mask - 1; 1283c50d8ae3SPaolo Bonzini } 1284c50d8ae3SPaolo Bonzini } 1285c50d8ae3SPaolo Bonzini 1286c50d8ae3SPaolo Bonzini /** 1287c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1288c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1289c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1290c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1291c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1292c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1293c50d8ae3SPaolo Bonzini * 1294c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1295c50d8ae3SPaolo Bonzini */ 1296a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1297c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1298c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1299c50d8ae3SPaolo Bonzini { 1300c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1301c50d8ae3SPaolo Bonzini 1302897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1303a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1304a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1305e2209710SBen Gardon 1306e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1307e2209710SBen Gardon return; 1308e2209710SBen Gardon 1309c50d8ae3SPaolo Bonzini while (mask) { 131093e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13113bae0459SSean Christopherson PG_LEVEL_4K, slot); 13120a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1313c50d8ae3SPaolo Bonzini 1314c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1315c50d8ae3SPaolo Bonzini mask &= mask - 1; 1316c50d8ae3SPaolo Bonzini } 1317c50d8ae3SPaolo Bonzini } 1318c50d8ae3SPaolo Bonzini 1319c50d8ae3SPaolo Bonzini /** 1320c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1321c50d8ae3SPaolo Bonzini * PT level pages. 1322c50d8ae3SPaolo Bonzini * 1323c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1324c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1325c50d8ae3SPaolo Bonzini * 132689212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 132789212919SKeqian Zhu * have such mappings. 1328c50d8ae3SPaolo Bonzini */ 1329c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1330c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1331c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1332c50d8ae3SPaolo Bonzini { 133389212919SKeqian Zhu /* 133489212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 133589212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 133689212919SKeqian Zhu * are split to 4K on the first write. 133789212919SKeqian Zhu * 133889212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 133989212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 134089212919SKeqian Zhu * pages. 134189212919SKeqian Zhu */ 134289212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 134389212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 134489212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 134589212919SKeqian Zhu 1346cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1347cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1348cb00a70bSDavid Matlack 134989212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 135089212919SKeqian Zhu 135189212919SKeqian Zhu /* Cross two large pages? */ 135289212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 135389212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 135489212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 135589212919SKeqian Zhu PG_LEVEL_2M); 135689212919SKeqian Zhu } 135789212919SKeqian Zhu 135889212919SKeqian Zhu /* Now handle 4K PTEs. */ 1359a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1360a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1361c50d8ae3SPaolo Bonzini else 1362c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1363c50d8ae3SPaolo Bonzini } 1364c50d8ae3SPaolo Bonzini 1365fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1366fb04a1edSPeter Xu { 13676dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1368fb04a1edSPeter Xu } 1369fb04a1edSPeter Xu 1370c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13713ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13723ad93562SKeqian Zhu int min_level) 1373c50d8ae3SPaolo Bonzini { 1374c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1375c50d8ae3SPaolo Bonzini int i; 1376c50d8ae3SPaolo Bonzini bool write_protected = false; 1377c50d8ae3SPaolo Bonzini 1378e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13793ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 138093e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13811346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1382c50d8ae3SPaolo Bonzini } 1383e2209710SBen Gardon } 1384c50d8ae3SPaolo Bonzini 1385897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 138646044f72SBen Gardon write_protected |= 13873ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 138846044f72SBen Gardon 1389c50d8ae3SPaolo Bonzini return write_protected; 1390c50d8ae3SPaolo Bonzini } 1391c50d8ae3SPaolo Bonzini 1392cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1393c50d8ae3SPaolo Bonzini { 1394c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1395c50d8ae3SPaolo Bonzini 1396c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 13973ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1398c50d8ae3SPaolo Bonzini } 1399c50d8ae3SPaolo Bonzini 14000a234f5dSSean Christopherson static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1401269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1402c50d8ae3SPaolo Bonzini { 140371f51d2cSMingwei Zhang return pte_list_destroy(kvm, rmap_head); 1404c50d8ae3SPaolo Bonzini } 1405c50d8ae3SPaolo Bonzini 14063039bcc7SSean Christopherson static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1407c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14083039bcc7SSean Christopherson pte_t unused) 1409c50d8ae3SPaolo Bonzini { 14100a234f5dSSean Christopherson return kvm_zap_rmapp(kvm, rmap_head, slot); 1411c50d8ae3SPaolo Bonzini } 1412c50d8ae3SPaolo Bonzini 14133039bcc7SSean Christopherson static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1414c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14153039bcc7SSean Christopherson pte_t pte) 1416c50d8ae3SPaolo Bonzini { 1417c50d8ae3SPaolo Bonzini u64 *sptep; 1418c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 141998a26b69SVihas Mak bool need_flush = false; 1420c50d8ae3SPaolo Bonzini u64 new_spte; 1421c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1422c50d8ae3SPaolo Bonzini 14233039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14243039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1425c50d8ae3SPaolo Bonzini 1426c50d8ae3SPaolo Bonzini restart: 1427c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1428805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1429c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1430c50d8ae3SPaolo Bonzini 143198a26b69SVihas Mak need_flush = true; 1432c50d8ae3SPaolo Bonzini 14333039bcc7SSean Christopherson if (pte_write(pte)) { 143471f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 1435c50d8ae3SPaolo Bonzini goto restart; 1436c50d8ae3SPaolo Bonzini } else { 1437cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1438cb3eedabSPaolo Bonzini *sptep, new_pfn); 1439c50d8ae3SPaolo Bonzini 144071f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1441c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1442c50d8ae3SPaolo Bonzini } 1443c50d8ae3SPaolo Bonzini } 1444c50d8ae3SPaolo Bonzini 1445c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1446c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 144798a26b69SVihas Mak return false; 1448c50d8ae3SPaolo Bonzini } 1449c50d8ae3SPaolo Bonzini 1450c50d8ae3SPaolo Bonzini return need_flush; 1451c50d8ae3SPaolo Bonzini } 1452c50d8ae3SPaolo Bonzini 1453c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1454c50d8ae3SPaolo Bonzini /* input fields. */ 1455269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1456c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1457c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1458c50d8ae3SPaolo Bonzini int start_level; 1459c50d8ae3SPaolo Bonzini int end_level; 1460c50d8ae3SPaolo Bonzini 1461c50d8ae3SPaolo Bonzini /* output fields. */ 1462c50d8ae3SPaolo Bonzini gfn_t gfn; 1463c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1464c50d8ae3SPaolo Bonzini int level; 1465c50d8ae3SPaolo Bonzini 1466c50d8ae3SPaolo Bonzini /* private field. */ 1467c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1468c50d8ae3SPaolo Bonzini }; 1469c50d8ae3SPaolo Bonzini 1470c50d8ae3SPaolo Bonzini static void 1471c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1472c50d8ae3SPaolo Bonzini { 1473c50d8ae3SPaolo Bonzini iterator->level = level; 1474c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 147593e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 147693e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1477c50d8ae3SPaolo Bonzini } 1478c50d8ae3SPaolo Bonzini 1479c50d8ae3SPaolo Bonzini static void 1480c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1481269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1482c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1483c50d8ae3SPaolo Bonzini { 1484c50d8ae3SPaolo Bonzini iterator->slot = slot; 1485c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1486c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1487c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1488c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1489c50d8ae3SPaolo Bonzini 1490c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1491c50d8ae3SPaolo Bonzini } 1492c50d8ae3SPaolo Bonzini 1493c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1494c50d8ae3SPaolo Bonzini { 1495c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1496c50d8ae3SPaolo Bonzini } 1497c50d8ae3SPaolo Bonzini 1498c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1499c50d8ae3SPaolo Bonzini { 1500c50d8ae3SPaolo Bonzini if (++iterator->rmap <= iterator->end_rmap) { 1501c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 1502c50d8ae3SPaolo Bonzini return; 1503c50d8ae3SPaolo Bonzini } 1504c50d8ae3SPaolo Bonzini 1505c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1506c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1507c50d8ae3SPaolo Bonzini return; 1508c50d8ae3SPaolo Bonzini } 1509c50d8ae3SPaolo Bonzini 1510c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1511c50d8ae3SPaolo Bonzini } 1512c50d8ae3SPaolo Bonzini 1513c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1514c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1515c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1516c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1517c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1518c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1519c50d8ae3SPaolo Bonzini 15203039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1521c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15223039bcc7SSean Christopherson int level, pte_t pte); 1523c1b91493SSean Christopherson 15243039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15253039bcc7SSean Christopherson struct kvm_gfn_range *range, 1526c1b91493SSean Christopherson rmap_handler_t handler) 1527c50d8ae3SPaolo Bonzini { 1528c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15293039bcc7SSean Christopherson bool ret = false; 1530c50d8ae3SPaolo Bonzini 15313039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15323039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15333039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15343039bcc7SSean Christopherson iterator.level, range->pte); 1535c50d8ae3SPaolo Bonzini 1536c50d8ae3SPaolo Bonzini return ret; 1537c50d8ae3SPaolo Bonzini } 1538c50d8ae3SPaolo Bonzini 15393039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1540c50d8ae3SPaolo Bonzini { 1541e2209710SBen Gardon bool flush = false; 1542c50d8ae3SPaolo Bonzini 1543e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15443039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp); 1545063afacdSBen Gardon 1546897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1547c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1548063afacdSBen Gardon 15493039bcc7SSean Christopherson return flush; 1550c50d8ae3SPaolo Bonzini } 1551c50d8ae3SPaolo Bonzini 15523039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1553c50d8ae3SPaolo Bonzini { 1554e2209710SBen Gardon bool flush = false; 15551d8dd6b3SBen Gardon 1556e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15573039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp); 15581d8dd6b3SBen Gardon 1559897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15603039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15611d8dd6b3SBen Gardon 15623039bcc7SSean Christopherson return flush; 1563c50d8ae3SPaolo Bonzini } 1564c50d8ae3SPaolo Bonzini 15653039bcc7SSean Christopherson static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1566c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15673039bcc7SSean Christopherson pte_t unused) 1568c50d8ae3SPaolo Bonzini { 1569c50d8ae3SPaolo Bonzini u64 *sptep; 15703f649ab7SKees Cook struct rmap_iterator iter; 1571c50d8ae3SPaolo Bonzini int young = 0; 1572c50d8ae3SPaolo Bonzini 1573c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1574c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1575c50d8ae3SPaolo Bonzini 1576c50d8ae3SPaolo Bonzini return young; 1577c50d8ae3SPaolo Bonzini } 1578c50d8ae3SPaolo Bonzini 15793039bcc7SSean Christopherson static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1580c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15813039bcc7SSean Christopherson int level, pte_t unused) 1582c50d8ae3SPaolo Bonzini { 1583c50d8ae3SPaolo Bonzini u64 *sptep; 1584c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1585c50d8ae3SPaolo Bonzini 1586c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1587c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 158898a26b69SVihas Mak return true; 158998a26b69SVihas Mak return false; 1590c50d8ae3SPaolo Bonzini } 1591c50d8ae3SPaolo Bonzini 1592c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1593c50d8ae3SPaolo Bonzini 15948a9f566aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 15958a9f566aSDavid Matlack u64 *spte, gfn_t gfn) 1596c50d8ae3SPaolo Bonzini { 1597c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 159868be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 159968be1306SDavid Matlack int rmap_count; 1600c50d8ae3SPaolo Bonzini 160157354682SSean Christopherson sp = sptep_to_sp(spte); 160268be1306SDavid Matlack kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn); 160393e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 160468be1306SDavid Matlack rmap_count = pte_list_add(vcpu, spte, rmap_head); 1605c50d8ae3SPaolo Bonzini 160668be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16073039bcc7SSean Christopherson kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0)); 160868be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 160968be1306SDavid Matlack vcpu->kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 161068be1306SDavid Matlack } 1611c50d8ae3SPaolo Bonzini } 1612c50d8ae3SPaolo Bonzini 16133039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1614c50d8ae3SPaolo Bonzini { 1615e2209710SBen Gardon bool young = false; 1616f8e14497SBen Gardon 1617e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16183039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp); 16193039bcc7SSean Christopherson 1620897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16213039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1622f8e14497SBen Gardon 1623f8e14497SBen Gardon return young; 1624c50d8ae3SPaolo Bonzini } 1625c50d8ae3SPaolo Bonzini 16263039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1627c50d8ae3SPaolo Bonzini { 1628e2209710SBen Gardon bool young = false; 1629f8e14497SBen Gardon 1630e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16313039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp); 16323039bcc7SSean Christopherson 1633897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16343039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1635f8e14497SBen Gardon 1636f8e14497SBen Gardon return young; 1637c50d8ae3SPaolo Bonzini } 1638c50d8ae3SPaolo Bonzini 1639c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1640c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1641c50d8ae3SPaolo Bonzini { 1642c50d8ae3SPaolo Bonzini u64 *pos; 1643c50d8ae3SPaolo Bonzini u64 *end; 1644c50d8ae3SPaolo Bonzini 1645c50d8ae3SPaolo Bonzini for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) 1646c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1647c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1648c50d8ae3SPaolo Bonzini pos, *pos); 1649c50d8ae3SPaolo Bonzini return 0; 1650c50d8ae3SPaolo Bonzini } 1651c50d8ae3SPaolo Bonzini return 1; 1652c50d8ae3SPaolo Bonzini } 1653c50d8ae3SPaolo Bonzini #endif 1654c50d8ae3SPaolo Bonzini 1655c50d8ae3SPaolo Bonzini /* 1656c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1657c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1658c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1659c50d8ae3SPaolo Bonzini * faster 1660c50d8ae3SPaolo Bonzini */ 1661d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1662c50d8ae3SPaolo Bonzini { 1663c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1664c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1665c50d8ae3SPaolo Bonzini } 1666c50d8ae3SPaolo Bonzini 1667c50d8ae3SPaolo Bonzini static void kvm_mmu_free_page(struct kvm_mmu_page *sp) 1668c50d8ae3SPaolo Bonzini { 1669c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1670c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1671c50d8ae3SPaolo Bonzini list_del(&sp->link); 1672c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1673c50d8ae3SPaolo Bonzini if (!sp->role.direct) 1674c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->gfns); 1675c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1676c50d8ae3SPaolo Bonzini } 1677c50d8ae3SPaolo Bonzini 1678c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1679c50d8ae3SPaolo Bonzini { 1680c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1681c50d8ae3SPaolo Bonzini } 1682c50d8ae3SPaolo Bonzini 1683c50d8ae3SPaolo Bonzini static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, 1684c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1685c50d8ae3SPaolo Bonzini { 1686c50d8ae3SPaolo Bonzini if (!parent_pte) 1687c50d8ae3SPaolo Bonzini return; 1688c50d8ae3SPaolo Bonzini 1689c50d8ae3SPaolo Bonzini pte_list_add(vcpu, parent_pte, &sp->parent_ptes); 1690c50d8ae3SPaolo Bonzini } 1691c50d8ae3SPaolo Bonzini 1692c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1693c50d8ae3SPaolo Bonzini u64 *parent_pte) 1694c50d8ae3SPaolo Bonzini { 1695c50d8ae3SPaolo Bonzini __pte_list_remove(parent_pte, &sp->parent_ptes); 1696c50d8ae3SPaolo Bonzini } 1697c50d8ae3SPaolo Bonzini 1698c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1699c50d8ae3SPaolo Bonzini u64 *parent_pte) 1700c50d8ae3SPaolo Bonzini { 1701c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1702c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1703c50d8ae3SPaolo Bonzini } 1704c50d8ae3SPaolo Bonzini 1705c50d8ae3SPaolo Bonzini static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct) 1706c50d8ae3SPaolo Bonzini { 1707c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1708c50d8ae3SPaolo Bonzini 170994ce87efSSean Christopherson sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache); 171094ce87efSSean Christopherson sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache); 1711c50d8ae3SPaolo Bonzini if (!direct) 171294ce87efSSean Christopherson sp->gfns = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache); 1713c50d8ae3SPaolo Bonzini set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 1714c50d8ae3SPaolo Bonzini 1715c50d8ae3SPaolo Bonzini /* 1716c50d8ae3SPaolo Bonzini * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 1717c50d8ae3SPaolo Bonzini * depends on valid pages being added to the head of the list. See 1718c50d8ae3SPaolo Bonzini * comments in kvm_zap_obsolete_pages(). 1719c50d8ae3SPaolo Bonzini */ 1720c50d8ae3SPaolo Bonzini sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; 1721c50d8ae3SPaolo Bonzini list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); 1722c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(vcpu->kvm, +1); 1723c50d8ae3SPaolo Bonzini return sp; 1724c50d8ae3SPaolo Bonzini } 1725c50d8ae3SPaolo Bonzini 1726c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1727c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1728c50d8ae3SPaolo Bonzini { 1729c50d8ae3SPaolo Bonzini u64 *sptep; 1730c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1731c50d8ae3SPaolo Bonzini 1732c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1733c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1734c50d8ae3SPaolo Bonzini } 1735c50d8ae3SPaolo Bonzini } 1736c50d8ae3SPaolo Bonzini 1737c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1738c50d8ae3SPaolo Bonzini { 1739c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1740c50d8ae3SPaolo Bonzini unsigned int index; 1741c50d8ae3SPaolo Bonzini 174257354682SSean Christopherson sp = sptep_to_sp(spte); 1743c50d8ae3SPaolo Bonzini index = spte - sp->spt; 1744c50d8ae3SPaolo Bonzini if (__test_and_set_bit(index, sp->unsync_child_bitmap)) 1745c50d8ae3SPaolo Bonzini return; 1746c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1747c50d8ae3SPaolo Bonzini return; 1748c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1749c50d8ae3SPaolo Bonzini } 1750c50d8ae3SPaolo Bonzini 1751c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1752c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1753c50d8ae3SPaolo Bonzini { 1754c3e5e415SLai Jiangshan return -1; 1755c50d8ae3SPaolo Bonzini } 1756c50d8ae3SPaolo Bonzini 1757c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1758c50d8ae3SPaolo Bonzini 1759c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1760c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1761c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1762c50d8ae3SPaolo Bonzini unsigned int idx; 1763c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1764c50d8ae3SPaolo Bonzini unsigned int nr; 1765c50d8ae3SPaolo Bonzini }; 1766c50d8ae3SPaolo Bonzini 1767c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1768c50d8ae3SPaolo Bonzini int idx) 1769c50d8ae3SPaolo Bonzini { 1770c50d8ae3SPaolo Bonzini int i; 1771c50d8ae3SPaolo Bonzini 1772c50d8ae3SPaolo Bonzini if (sp->unsync) 1773c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1774c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1775c50d8ae3SPaolo Bonzini return 0; 1776c50d8ae3SPaolo Bonzini 1777c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1778c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1779c50d8ae3SPaolo Bonzini pvec->nr++; 1780c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1781c50d8ae3SPaolo Bonzini } 1782c50d8ae3SPaolo Bonzini 1783c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1784c50d8ae3SPaolo Bonzini { 1785c50d8ae3SPaolo Bonzini --sp->unsync_children; 1786c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1787c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1788c50d8ae3SPaolo Bonzini } 1789c50d8ae3SPaolo Bonzini 1790c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1791c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1792c50d8ae3SPaolo Bonzini { 1793c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1794c50d8ae3SPaolo Bonzini 1795c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1796c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1797c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1798c50d8ae3SPaolo Bonzini 1799c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1800c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1801c50d8ae3SPaolo Bonzini continue; 1802c50d8ae3SPaolo Bonzini } 1803c50d8ae3SPaolo Bonzini 1804e47c4aeeSSean Christopherson child = to_shadow_page(ent & PT64_BASE_ADDR_MASK); 1805c50d8ae3SPaolo Bonzini 1806c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1807c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1808c50d8ae3SPaolo Bonzini return -ENOSPC; 1809c50d8ae3SPaolo Bonzini 1810c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1811c50d8ae3SPaolo Bonzini if (!ret) { 1812c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1813c50d8ae3SPaolo Bonzini continue; 1814c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1815c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1816c50d8ae3SPaolo Bonzini } else 1817c50d8ae3SPaolo Bonzini return ret; 1818c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1819c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1820c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1821c50d8ae3SPaolo Bonzini return -ENOSPC; 1822c50d8ae3SPaolo Bonzini } else 1823c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1824c50d8ae3SPaolo Bonzini } 1825c50d8ae3SPaolo Bonzini 1826c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1827c50d8ae3SPaolo Bonzini } 1828c50d8ae3SPaolo Bonzini 1829c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1830c50d8ae3SPaolo Bonzini 1831c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1832c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1833c50d8ae3SPaolo Bonzini { 1834c50d8ae3SPaolo Bonzini pvec->nr = 0; 1835c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1836c50d8ae3SPaolo Bonzini return 0; 1837c50d8ae3SPaolo Bonzini 1838c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1839c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1840c50d8ae3SPaolo Bonzini } 1841c50d8ae3SPaolo Bonzini 1842c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1843c50d8ae3SPaolo Bonzini { 1844c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1845c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1846c50d8ae3SPaolo Bonzini sp->unsync = 0; 1847c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1848c50d8ae3SPaolo Bonzini } 1849c50d8ae3SPaolo Bonzini 1850c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1851c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1852c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1853c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1854c50d8ae3SPaolo Bonzini 1855ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1856ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1857c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1858c50d8ae3SPaolo Bonzini } else 1859c50d8ae3SPaolo Bonzini 1860c50d8ae3SPaolo Bonzini #define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn) \ 1861ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1862ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1863c50d8ae3SPaolo Bonzini if ((_sp)->gfn != (_gfn) || (_sp)->role.direct) {} else 1864c50d8ae3SPaolo Bonzini 18658d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1866c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1867c50d8ae3SPaolo Bonzini { 1868c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1869c3e5e415SLai Jiangshan 18708d5678a7SHou Wenlong if (ret < 0) 1871c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18728d5678a7SHou Wenlong return ret; 1873c50d8ae3SPaolo Bonzini } 1874c50d8ae3SPaolo Bonzini 1875c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1876c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1877c50d8ae3SPaolo Bonzini bool remote_flush) 1878c50d8ae3SPaolo Bonzini { 1879c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1880c50d8ae3SPaolo Bonzini return false; 1881c50d8ae3SPaolo Bonzini 1882c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1883c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1884c50d8ae3SPaolo Bonzini else 1885c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1886c50d8ae3SPaolo Bonzini return true; 1887c50d8ae3SPaolo Bonzini } 1888c50d8ae3SPaolo Bonzini 1889c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1890c50d8ae3SPaolo Bonzini { 1891a955cad8SSean Christopherson if (sp->role.invalid) 1892a955cad8SSean Christopherson return true; 1893a955cad8SSean Christopherson 1894a955cad8SSean Christopherson /* TDP MMU pages due not use the MMU generation. */ 1895a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1896c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1897c50d8ae3SPaolo Bonzini } 1898c50d8ae3SPaolo Bonzini 1899c50d8ae3SPaolo Bonzini struct mmu_page_path { 1900c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1901c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1902c50d8ae3SPaolo Bonzini }; 1903c50d8ae3SPaolo Bonzini 1904c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1905c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1906c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1907c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1908c50d8ae3SPaolo Bonzini 1909c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1910c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1911c50d8ae3SPaolo Bonzini int i) 1912c50d8ae3SPaolo Bonzini { 1913c50d8ae3SPaolo Bonzini int n; 1914c50d8ae3SPaolo Bonzini 1915c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1916c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1917c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1918c50d8ae3SPaolo Bonzini int level = sp->role.level; 1919c50d8ae3SPaolo Bonzini 1920c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19213bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1922c50d8ae3SPaolo Bonzini break; 1923c50d8ae3SPaolo Bonzini 1924c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1925c50d8ae3SPaolo Bonzini } 1926c50d8ae3SPaolo Bonzini 1927c50d8ae3SPaolo Bonzini return n; 1928c50d8ae3SPaolo Bonzini } 1929c50d8ae3SPaolo Bonzini 1930c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1931c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1932c50d8ae3SPaolo Bonzini { 1933c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1934c50d8ae3SPaolo Bonzini int level; 1935c50d8ae3SPaolo Bonzini 1936c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1937c50d8ae3SPaolo Bonzini return 0; 1938c50d8ae3SPaolo Bonzini 1939c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1940c50d8ae3SPaolo Bonzini 1941c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1942c50d8ae3SPaolo Bonzini level = sp->role.level; 19433bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1944c50d8ae3SPaolo Bonzini 1945c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1946c50d8ae3SPaolo Bonzini 1947c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1948c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1949c50d8ae3SPaolo Bonzini */ 1950c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1951c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1952c50d8ae3SPaolo Bonzini } 1953c50d8ae3SPaolo Bonzini 1954c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1955c50d8ae3SPaolo Bonzini { 1956c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1957c50d8ae3SPaolo Bonzini unsigned int level = 0; 1958c50d8ae3SPaolo Bonzini 1959c50d8ae3SPaolo Bonzini do { 1960c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1961c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1962c50d8ae3SPaolo Bonzini if (!sp) 1963c50d8ae3SPaolo Bonzini return; 1964c50d8ae3SPaolo Bonzini 1965c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1966c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1967c50d8ae3SPaolo Bonzini level++; 1968c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1969c50d8ae3SPaolo Bonzini } 1970c50d8ae3SPaolo Bonzini 197165855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 197265855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1973c50d8ae3SPaolo Bonzini { 1974c50d8ae3SPaolo Bonzini int i; 1975c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1976c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1977c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1978c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1979c50d8ae3SPaolo Bonzini bool flush = false; 1980c50d8ae3SPaolo Bonzini 1981c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 1982c50d8ae3SPaolo Bonzini bool protected = false; 1983c50d8ae3SPaolo Bonzini 1984c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 1985cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 1986c50d8ae3SPaolo Bonzini 1987c50d8ae3SPaolo Bonzini if (protected) { 19885591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 1989c50d8ae3SPaolo Bonzini flush = false; 1990c50d8ae3SPaolo Bonzini } 1991c50d8ae3SPaolo Bonzini 1992c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 1993479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 19948d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 1995c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 1996c50d8ae3SPaolo Bonzini } 1997531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 1998c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 199965855ed8SLai Jiangshan if (!can_yield) { 200065855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 200165855ed8SLai Jiangshan return -EINTR; 200265855ed8SLai Jiangshan } 200365855ed8SLai Jiangshan 2004531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2005c50d8ae3SPaolo Bonzini flush = false; 2006c50d8ae3SPaolo Bonzini } 2007c50d8ae3SPaolo Bonzini } 2008c50d8ae3SPaolo Bonzini 2009c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 201065855ed8SLai Jiangshan return 0; 2011c50d8ae3SPaolo Bonzini } 2012c50d8ae3SPaolo Bonzini 2013c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2014c50d8ae3SPaolo Bonzini { 2015c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2016c50d8ae3SPaolo Bonzini } 2017c50d8ae3SPaolo Bonzini 2018c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2019c50d8ae3SPaolo Bonzini { 202057354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2021c50d8ae3SPaolo Bonzini } 2022c50d8ae3SPaolo Bonzini 2023c50d8ae3SPaolo Bonzini static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, 2024c50d8ae3SPaolo Bonzini gfn_t gfn, 2025c50d8ae3SPaolo Bonzini gva_t gaddr, 2026c50d8ae3SPaolo Bonzini unsigned level, 2027c50d8ae3SPaolo Bonzini int direct, 20280a2b64c5SBen Gardon unsigned int access) 2029c50d8ae3SPaolo Bonzini { 2030fb58a9c3SSean Christopherson bool direct_mmu = vcpu->arch.mmu->direct_map; 2031c50d8ae3SPaolo Bonzini union kvm_mmu_page_role role; 2032ac101b7cSSean Christopherson struct hlist_head *sp_list; 2033c50d8ae3SPaolo Bonzini unsigned quadrant; 2034c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20358d5678a7SHou Wenlong int ret; 2036c50d8ae3SPaolo Bonzini int collisions = 0; 2037c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2038c50d8ae3SPaolo Bonzini 20397a458f0eSPaolo Bonzini role = vcpu->arch.mmu->root_role; 2040c50d8ae3SPaolo Bonzini role.level = level; 2041c50d8ae3SPaolo Bonzini role.direct = direct; 2042c50d8ae3SPaolo Bonzini role.access = access; 2043bb3b394dSLai Jiangshan if (role.has_4_byte_gpte) { 2044c50d8ae3SPaolo Bonzini quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level)); 2045c50d8ae3SPaolo Bonzini quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; 2046c50d8ae3SPaolo Bonzini role.quadrant = quadrant; 2047c50d8ae3SPaolo Bonzini } 2048ac101b7cSSean Christopherson 2049ac101b7cSSean Christopherson sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 2050ac101b7cSSean Christopherson for_each_valid_sp(vcpu->kvm, sp, sp_list) { 2051c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2052c50d8ae3SPaolo Bonzini collisions++; 2053c50d8ae3SPaolo Bonzini continue; 2054c50d8ae3SPaolo Bonzini } 2055c50d8ae3SPaolo Bonzini 2056ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2057ddc16abbSSean Christopherson /* 2058ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2059ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2060ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2061ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2062ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2063ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2064ddc16abbSSean Christopherson * upper-level page will be write-protected. 2065ddc16abbSSean Christopherson */ 2066ddc16abbSSean Christopherson if (level > PG_LEVEL_4K && sp->unsync) 2067ddc16abbSSean Christopherson kvm_mmu_prepare_zap_page(vcpu->kvm, sp, 2068ddc16abbSSean Christopherson &invalid_list); 2069c50d8ae3SPaolo Bonzini continue; 2070ddc16abbSSean Christopherson } 2071c50d8ae3SPaolo Bonzini 2072fb58a9c3SSean Christopherson if (direct_mmu) 2073fb58a9c3SSean Christopherson goto trace_get_page; 2074fb58a9c3SSean Christopherson 2075c50d8ae3SPaolo Bonzini if (sp->unsync) { 207607dc4f35SSean Christopherson /* 2077479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 207807dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 207907dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 208007dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 208107dc4f35SSean Christopherson * overhead of write protection is not incurred until the 208207dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 208307dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 208407dc4f35SSean Christopherson * 208507dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 208607dc4f35SSean Christopherson * in order to rebuild it. 2087c50d8ae3SPaolo Bonzini */ 20888d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 20898d5678a7SHou Wenlong if (ret < 0) 2090c50d8ae3SPaolo Bonzini break; 2091c50d8ae3SPaolo Bonzini 2092c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 20938d5678a7SHou Wenlong if (ret > 0) 2094c3e5e415SLai Jiangshan kvm_flush_remote_tlbs(vcpu->kvm); 2095c50d8ae3SPaolo Bonzini } 2096c50d8ae3SPaolo Bonzini 2097c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2098fb58a9c3SSean Christopherson 2099fb58a9c3SSean Christopherson trace_get_page: 2100c50d8ae3SPaolo Bonzini trace_kvm_mmu_get_page(sp, false); 2101c50d8ae3SPaolo Bonzini goto out; 2102c50d8ae3SPaolo Bonzini } 2103c50d8ae3SPaolo Bonzini 2104c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_cache_miss; 2105c50d8ae3SPaolo Bonzini 2106c50d8ae3SPaolo Bonzini sp = kvm_mmu_alloc_page(vcpu, direct); 2107c50d8ae3SPaolo Bonzini 2108c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2109c50d8ae3SPaolo Bonzini sp->role = role; 2110ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2111c50d8ae3SPaolo Bonzini if (!direct) { 2112c50d8ae3SPaolo Bonzini account_shadowed(vcpu->kvm, sp); 2113cf48f9e2SDavid Matlack if (level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn)) 2114c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1); 2115c50d8ae3SPaolo Bonzini } 2116c50d8ae3SPaolo Bonzini trace_kvm_mmu_get_page(sp, true); 2117c50d8ae3SPaolo Bonzini out: 2118ddc16abbSSean Christopherson kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); 2119ddc16abbSSean Christopherson 2120c50d8ae3SPaolo Bonzini if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions) 2121c50d8ae3SPaolo Bonzini vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions; 2122c50d8ae3SPaolo Bonzini return sp; 2123c50d8ae3SPaolo Bonzini } 2124c50d8ae3SPaolo Bonzini 2125c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2126c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2127c50d8ae3SPaolo Bonzini u64 addr) 2128c50d8ae3SPaolo Bonzini { 2129c50d8ae3SPaolo Bonzini iterator->addr = addr; 2130c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2131c50d8ae3SPaolo Bonzini iterator->level = vcpu->arch.mmu->shadow_root_level; 2132c50d8ae3SPaolo Bonzini 213312ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 2134c50d8ae3SPaolo Bonzini vcpu->arch.mmu->root_level < PT64_ROOT_4LEVEL && 2135c50d8ae3SPaolo Bonzini !vcpu->arch.mmu->direct_map) 213612ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2137c50d8ae3SPaolo Bonzini 2138c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2139c50d8ae3SPaolo Bonzini /* 2140c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2141c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2142c50d8ae3SPaolo Bonzini */ 2143b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2144c50d8ae3SPaolo Bonzini 2145c50d8ae3SPaolo Bonzini iterator->shadow_addr 2146c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 2147c50d8ae3SPaolo Bonzini iterator->shadow_addr &= PT64_BASE_ADDR_MASK; 2148c50d8ae3SPaolo Bonzini --iterator->level; 2149c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2150c50d8ae3SPaolo Bonzini iterator->level = 0; 2151c50d8ae3SPaolo Bonzini } 2152c50d8ae3SPaolo Bonzini } 2153c50d8ae3SPaolo Bonzini 2154c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2155c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2156c50d8ae3SPaolo Bonzini { 2157b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2158c50d8ae3SPaolo Bonzini addr); 2159c50d8ae3SPaolo Bonzini } 2160c50d8ae3SPaolo Bonzini 2161c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2162c50d8ae3SPaolo Bonzini { 21633bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2164c50d8ae3SPaolo Bonzini return false; 2165c50d8ae3SPaolo Bonzini 2166c50d8ae3SPaolo Bonzini iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level); 2167c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2168c50d8ae3SPaolo Bonzini return true; 2169c50d8ae3SPaolo Bonzini } 2170c50d8ae3SPaolo Bonzini 2171c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2172c50d8ae3SPaolo Bonzini u64 spte) 2173c50d8ae3SPaolo Bonzini { 21743e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2175c50d8ae3SPaolo Bonzini iterator->level = 0; 2176c50d8ae3SPaolo Bonzini return; 2177c50d8ae3SPaolo Bonzini } 2178c50d8ae3SPaolo Bonzini 2179c50d8ae3SPaolo Bonzini iterator->shadow_addr = spte & PT64_BASE_ADDR_MASK; 2180c50d8ae3SPaolo Bonzini --iterator->level; 2181c50d8ae3SPaolo Bonzini } 2182c50d8ae3SPaolo Bonzini 2183c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2184c50d8ae3SPaolo Bonzini { 2185c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2186c50d8ae3SPaolo Bonzini } 2187c50d8ae3SPaolo Bonzini 2188c50d8ae3SPaolo Bonzini static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 2189c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 2190c50d8ae3SPaolo Bonzini { 2191c50d8ae3SPaolo Bonzini u64 spte; 2192c50d8ae3SPaolo Bonzini 2193c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2194c50d8ae3SPaolo Bonzini 2195cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2196c50d8ae3SPaolo Bonzini 2197c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2198c50d8ae3SPaolo Bonzini 2199c50d8ae3SPaolo Bonzini mmu_page_add_parent_pte(vcpu, sp, sptep); 2200c50d8ae3SPaolo Bonzini 2201c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2202c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2203c50d8ae3SPaolo Bonzini } 2204c50d8ae3SPaolo Bonzini 2205c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2206c50d8ae3SPaolo Bonzini unsigned direct_access) 2207c50d8ae3SPaolo Bonzini { 2208c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2209c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2210c50d8ae3SPaolo Bonzini 2211c50d8ae3SPaolo Bonzini /* 2212c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2213c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2214c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2215c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2216c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2217c50d8ae3SPaolo Bonzini */ 2218e47c4aeeSSean Christopherson child = to_shadow_page(*sptep & PT64_BASE_ADDR_MASK); 2219c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2220c50d8ae3SPaolo Bonzini return; 2221c50d8ae3SPaolo Bonzini 2222c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2223c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2224c50d8ae3SPaolo Bonzini } 2225c50d8ae3SPaolo Bonzini } 2226c50d8ae3SPaolo Bonzini 22272de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 22282de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 22292de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2230c50d8ae3SPaolo Bonzini { 2231c50d8ae3SPaolo Bonzini u64 pte; 2232c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2233c50d8ae3SPaolo Bonzini 2234c50d8ae3SPaolo Bonzini pte = *spte; 2235c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2236c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2237c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2238c50d8ae3SPaolo Bonzini } else { 2239e47c4aeeSSean Christopherson child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); 2240c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 22412de4085cSBen Gardon 22422de4085cSBen Gardon /* 22432de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 22442de4085cSBen Gardon * unlikely to be used again in the near future. This 22452de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 22462de4085cSBen Gardon */ 22472de4085cSBen Gardon if (tdp_enabled && invalid_list && 22482de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 22492de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 22502de4085cSBen Gardon invalid_list); 2251c50d8ae3SPaolo Bonzini } 2252ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2253c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2254ace569e0SSean Christopherson } 22552de4085cSBen Gardon return 0; 2256c50d8ae3SPaolo Bonzini } 2257c50d8ae3SPaolo Bonzini 22582de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 22592de4085cSBen Gardon struct kvm_mmu_page *sp, 22602de4085cSBen Gardon struct list_head *invalid_list) 2261c50d8ae3SPaolo Bonzini { 22622de4085cSBen Gardon int zapped = 0; 2263c50d8ae3SPaolo Bonzini unsigned i; 2264c50d8ae3SPaolo Bonzini 2265c50d8ae3SPaolo Bonzini for (i = 0; i < PT64_ENT_PER_PAGE; ++i) 22662de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 22672de4085cSBen Gardon 22682de4085cSBen Gardon return zapped; 2269c50d8ae3SPaolo Bonzini } 2270c50d8ae3SPaolo Bonzini 227161827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2272c50d8ae3SPaolo Bonzini { 2273c50d8ae3SPaolo Bonzini u64 *sptep; 2274c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2275c50d8ae3SPaolo Bonzini 2276c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2277c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2278c50d8ae3SPaolo Bonzini } 2279c50d8ae3SPaolo Bonzini 2280c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2281c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2282c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2283c50d8ae3SPaolo Bonzini { 2284c50d8ae3SPaolo Bonzini int i, zapped = 0; 2285c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2286c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2287c50d8ae3SPaolo Bonzini 22883bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2289c50d8ae3SPaolo Bonzini return 0; 2290c50d8ae3SPaolo Bonzini 2291c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2292c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2293c50d8ae3SPaolo Bonzini 2294c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2295c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2296c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2297c50d8ae3SPaolo Bonzini zapped++; 2298c50d8ae3SPaolo Bonzini } 2299c50d8ae3SPaolo Bonzini } 2300c50d8ae3SPaolo Bonzini 2301c50d8ae3SPaolo Bonzini return zapped; 2302c50d8ae3SPaolo Bonzini } 2303c50d8ae3SPaolo Bonzini 2304c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2305c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2306c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2307c50d8ae3SPaolo Bonzini int *nr_zapped) 2308c50d8ae3SPaolo Bonzini { 2309527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2310c50d8ae3SPaolo Bonzini 2311c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2312c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2313c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 23142de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 231561827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2316c50d8ae3SPaolo Bonzini 2317c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2318c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2319c50d8ae3SPaolo Bonzini 2320c50d8ae3SPaolo Bonzini if (!sp->role.invalid && !sp->role.direct) 2321c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2322c50d8ae3SPaolo Bonzini 2323c50d8ae3SPaolo Bonzini if (sp->unsync) 2324c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2325c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2326c50d8ae3SPaolo Bonzini /* Count self */ 2327c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2328f95eec9bSSean Christopherson 2329f95eec9bSSean Christopherson /* 2330f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2331f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2332f95eec9bSSean Christopherson * !sp->root_count. 2333f95eec9bSSean Christopherson */ 2334f95eec9bSSean Christopherson if (sp->role.invalid) 2335f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2336f95eec9bSSean Christopherson else 2337c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 2338c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(kvm, -1); 2339c50d8ae3SPaolo Bonzini } else { 2340f95eec9bSSean Christopherson /* 2341f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2342f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2343f95eec9bSSean Christopherson */ 2344f95eec9bSSean Christopherson list_del(&sp->link); 2345c50d8ae3SPaolo Bonzini 2346c50d8ae3SPaolo Bonzini /* 2347c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2348c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2349c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2350c50d8ae3SPaolo Bonzini */ 2351527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2352c50d8ae3SPaolo Bonzini } 2353c50d8ae3SPaolo Bonzini 2354c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2355c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2356c50d8ae3SPaolo Bonzini 2357c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2358527d5cd7SSean Christopherson 2359527d5cd7SSean Christopherson /* 2360527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2361527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2362527d5cd7SSean Christopherson */ 2363527d5cd7SSean Christopherson if (zapped_root) 2364527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2365c50d8ae3SPaolo Bonzini return list_unstable; 2366c50d8ae3SPaolo Bonzini } 2367c50d8ae3SPaolo Bonzini 2368c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2369c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2370c50d8ae3SPaolo Bonzini { 2371c50d8ae3SPaolo Bonzini int nr_zapped; 2372c50d8ae3SPaolo Bonzini 2373c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2374c50d8ae3SPaolo Bonzini return nr_zapped; 2375c50d8ae3SPaolo Bonzini } 2376c50d8ae3SPaolo Bonzini 2377c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2378c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2379c50d8ae3SPaolo Bonzini { 2380c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2381c50d8ae3SPaolo Bonzini 2382c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2383c50d8ae3SPaolo Bonzini return; 2384c50d8ae3SPaolo Bonzini 2385c50d8ae3SPaolo Bonzini /* 2386c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2387c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2388c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2389c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2390c50d8ae3SPaolo Bonzini * 2391c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2392c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2393c50d8ae3SPaolo Bonzini */ 2394c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2395c50d8ae3SPaolo Bonzini 2396c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2397c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 2398c50d8ae3SPaolo Bonzini kvm_mmu_free_page(sp); 2399c50d8ae3SPaolo Bonzini } 2400c50d8ae3SPaolo Bonzini } 2401c50d8ae3SPaolo Bonzini 24026b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 24036b82ef2cSSean Christopherson unsigned long nr_to_zap) 2404c50d8ae3SPaolo Bonzini { 24056b82ef2cSSean Christopherson unsigned long total_zapped = 0; 24066b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2407ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 24086b82ef2cSSean Christopherson bool unstable; 24096b82ef2cSSean Christopherson int nr_zapped; 2410c50d8ae3SPaolo Bonzini 2411c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2412ba7888ddSSean Christopherson return 0; 2413c50d8ae3SPaolo Bonzini 24146b82ef2cSSean Christopherson restart: 24158fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 24166b82ef2cSSean Christopherson /* 24176b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 24186b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 24196b82ef2cSSean Christopherson */ 24206b82ef2cSSean Christopherson if (sp->root_count) 24216b82ef2cSSean Christopherson continue; 24226b82ef2cSSean Christopherson 24236b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 24246b82ef2cSSean Christopherson &nr_zapped); 24256b82ef2cSSean Christopherson total_zapped += nr_zapped; 24266b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2427ba7888ddSSean Christopherson break; 2428ba7888ddSSean Christopherson 24296b82ef2cSSean Christopherson if (unstable) 24306b82ef2cSSean Christopherson goto restart; 2431ba7888ddSSean Christopherson } 24326b82ef2cSSean Christopherson 24336b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 24346b82ef2cSSean Christopherson 24356b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 24366b82ef2cSSean Christopherson return total_zapped; 24376b82ef2cSSean Christopherson } 24386b82ef2cSSean Christopherson 2439afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2440afe8d7e6SSean Christopherson { 2441afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2442afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2443afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2444afe8d7e6SSean Christopherson 2445afe8d7e6SSean Christopherson return 0; 2446c50d8ae3SPaolo Bonzini } 2447c50d8ae3SPaolo Bonzini 2448ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2449ba7888ddSSean Christopherson { 24506b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2451ba7888ddSSean Christopherson 24526b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2453ba7888ddSSean Christopherson return 0; 2454ba7888ddSSean Christopherson 24556b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2456ba7888ddSSean Christopherson 24576e6ec584SSean Christopherson /* 24586e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 24596e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 24606e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 24616e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2462c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 24636e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 24646e6ec584SSean Christopherson * page fault paths. 24656e6ec584SSean Christopherson */ 2466ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2467ba7888ddSSean Christopherson return -ENOSPC; 2468ba7888ddSSean Christopherson return 0; 2469ba7888ddSSean Christopherson } 2470ba7888ddSSean Christopherson 2471c50d8ae3SPaolo Bonzini /* 2472c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2473c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2474c50d8ae3SPaolo Bonzini */ 2475c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2476c50d8ae3SPaolo Bonzini { 2477531810caSBen Gardon write_lock(&kvm->mmu_lock); 2478c50d8ae3SPaolo Bonzini 2479c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 24806b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 24816b82ef2cSSean Christopherson goal_nr_mmu_pages); 2482c50d8ae3SPaolo Bonzini 2483c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2484c50d8ae3SPaolo Bonzini } 2485c50d8ae3SPaolo Bonzini 2486c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2487c50d8ae3SPaolo Bonzini 2488531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2489c50d8ae3SPaolo Bonzini } 2490c50d8ae3SPaolo Bonzini 2491c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2492c50d8ae3SPaolo Bonzini { 2493c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2494c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2495c50d8ae3SPaolo Bonzini int r; 2496c50d8ae3SPaolo Bonzini 2497c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2498c50d8ae3SPaolo Bonzini r = 0; 2499531810caSBen Gardon write_lock(&kvm->mmu_lock); 2500c50d8ae3SPaolo Bonzini for_each_gfn_indirect_valid_sp(kvm, sp, gfn) { 2501c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2502c50d8ae3SPaolo Bonzini sp->role.word); 2503c50d8ae3SPaolo Bonzini r = 1; 2504c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2505c50d8ae3SPaolo Bonzini } 2506c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2507531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2508c50d8ae3SPaolo Bonzini 2509c50d8ae3SPaolo Bonzini return r; 2510c50d8ae3SPaolo Bonzini } 251196ad91aeSSean Christopherson 251296ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 251396ad91aeSSean Christopherson { 251496ad91aeSSean Christopherson gpa_t gpa; 251596ad91aeSSean Christopherson int r; 251696ad91aeSSean Christopherson 251796ad91aeSSean Christopherson if (vcpu->arch.mmu->direct_map) 251896ad91aeSSean Christopherson return 0; 251996ad91aeSSean Christopherson 252096ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 252196ad91aeSSean Christopherson 252296ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 252396ad91aeSSean Christopherson 252496ad91aeSSean Christopherson return r; 252596ad91aeSSean Christopherson } 2526c50d8ae3SPaolo Bonzini 25274d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2528c50d8ae3SPaolo Bonzini { 2529c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 25304d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2531c50d8ae3SPaolo Bonzini sp->unsync = 1; 2532c50d8ae3SPaolo Bonzini 2533c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2534c50d8ae3SPaolo Bonzini } 2535c50d8ae3SPaolo Bonzini 25360337f585SSean Christopherson /* 25370337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 25380337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 25390337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 25400337f585SSean Christopherson * be write-protected. 25410337f585SSean Christopherson */ 25428283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 25432839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2544c50d8ae3SPaolo Bonzini { 2545c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2546ce25681dSSean Christopherson bool locked = false; 2547c50d8ae3SPaolo Bonzini 25480337f585SSean Christopherson /* 25490337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 25500337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 25510337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 25520337f585SSean Christopherson */ 25534d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 25540337f585SSean Christopherson return -EPERM; 2555c50d8ae3SPaolo Bonzini 25560337f585SSean Christopherson /* 25570337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 25580337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 25590337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 25600337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 25610337f585SSean Christopherson */ 25624d78d0b3SBen Gardon for_each_gfn_indirect_valid_sp(kvm, sp, gfn) { 2563c50d8ae3SPaolo Bonzini if (!can_unsync) 25640337f585SSean Christopherson return -EPERM; 2565c50d8ae3SPaolo Bonzini 2566c50d8ae3SPaolo Bonzini if (sp->unsync) 2567c50d8ae3SPaolo Bonzini continue; 2568c50d8ae3SPaolo Bonzini 25692839180cSPaolo Bonzini if (prefetch) 2570f1c4a88cSLai Jiangshan return -EEXIST; 2571f1c4a88cSLai Jiangshan 2572ce25681dSSean Christopherson /* 2573ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2574ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2575ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2576ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2577ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2578ce25681dSSean Christopherson */ 2579ce25681dSSean Christopherson if (!locked) { 2580ce25681dSSean Christopherson locked = true; 25814d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2582ce25681dSSean Christopherson 2583ce25681dSSean Christopherson /* 2584ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2585ce25681dSSean Christopherson * may have since marked the page unsync. A false 2586ce25681dSSean Christopherson * positive on the unprotected check above is not 2587ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2588ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2589ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2590ce25681dSSean Christopherson */ 2591ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2592ce25681dSSean Christopherson continue; 2593ce25681dSSean Christopherson } 2594ce25681dSSean Christopherson 25953bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 25964d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2597c50d8ae3SPaolo Bonzini } 2598ce25681dSSean Christopherson if (locked) 25994d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2600c50d8ae3SPaolo Bonzini 2601c50d8ae3SPaolo Bonzini /* 2602c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2603c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2604c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2605c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2606c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2607c50d8ae3SPaolo Bonzini * following could happen: 2608c50d8ae3SPaolo Bonzini * 2609c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2610c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2611c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2612c50d8ae3SPaolo Bonzini * to be writable 2613c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2614c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2615c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2616c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2617c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2618c50d8ae3SPaolo Bonzini * fault. 2619c50d8ae3SPaolo Bonzini * 2620c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2621c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2622c50d8ae3SPaolo Bonzini * 26230337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 26240337f585SSean Christopherson * false and skips the page. 2625c50d8ae3SPaolo Bonzini * 2626c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2627c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2628c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2629c50d8ae3SPaolo Bonzini * gets used. 2630c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2631c50d8ae3SPaolo Bonzini * as unsync 2632c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2633c50d8ae3SPaolo Bonzini * 2634c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2635264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2636264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2637c50d8ae3SPaolo Bonzini */ 2638c50d8ae3SPaolo Bonzini smp_wmb(); 2639c50d8ae3SPaolo Bonzini 26400337f585SSean Christopherson return 0; 2641c50d8ae3SPaolo Bonzini } 2642c50d8ae3SPaolo Bonzini 26438a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 26448a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2645a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2646799a4190SBen Gardon { 2647d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2648eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2649c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2650c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2651c50d8ae3SPaolo Bonzini bool flush = false; 2652ad67e480SPaolo Bonzini bool wrprot; 2653d786c778SPaolo Bonzini u64 spte; 2654c50d8ae3SPaolo Bonzini 2655a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2656a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 26572839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2658a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2659c50d8ae3SPaolo Bonzini 2660c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2661c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2662c50d8ae3SPaolo Bonzini 2663a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 2664a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2665a54aa15cSSean Christopherson return RET_PF_EMULATE; 2666a54aa15cSSean Christopherson } 2667a54aa15cSSean Christopherson 2668c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2669c50d8ae3SPaolo Bonzini /* 2670c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2671c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2672c50d8ae3SPaolo Bonzini */ 26733bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2674c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2675c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2676c50d8ae3SPaolo Bonzini 2677e47c4aeeSSean Christopherson child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); 2678c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2679c50d8ae3SPaolo Bonzini flush = true; 2680c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2681c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2682c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2683c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2684c50d8ae3SPaolo Bonzini flush = true; 2685c50d8ae3SPaolo Bonzini } else 2686c50d8ae3SPaolo Bonzini was_rmapped = 1; 2687c50d8ae3SPaolo Bonzini } 2688c50d8ae3SPaolo Bonzini 26892839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 26907158bee4SPaolo Bonzini true, host_writable, &spte); 2691d786c778SPaolo Bonzini 2692d786c778SPaolo Bonzini if (*sptep == spte) { 2693d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2694d786c778SPaolo Bonzini } else { 2695d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 26965959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2697c50d8ae3SPaolo Bonzini } 2698c50d8ae3SPaolo Bonzini 2699ad67e480SPaolo Bonzini if (wrprot) { 2700c50d8ae3SPaolo Bonzini if (write_fault) 2701c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2702c50d8ae3SPaolo Bonzini } 2703c50d8ae3SPaolo Bonzini 2704d786c778SPaolo Bonzini if (flush) 2705c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2706c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2707c50d8ae3SPaolo Bonzini 2708c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2709c50d8ae3SPaolo Bonzini 2710c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2711d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 271271f51d2cSMingwei Zhang kvm_update_page_stats(vcpu->kvm, level, 1); 27138a9f566aSDavid Matlack rmap_add(vcpu, slot, sptep, gfn); 2714c50d8ae3SPaolo Bonzini } 2715c50d8ae3SPaolo Bonzini 2716c50d8ae3SPaolo Bonzini return ret; 2717c50d8ae3SPaolo Bonzini } 2718c50d8ae3SPaolo Bonzini 2719c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2720c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2721c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2722c50d8ae3SPaolo Bonzini { 2723c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2724c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 27250a2b64c5SBen Gardon unsigned int access = sp->role.access; 2726c50d8ae3SPaolo Bonzini int i, ret; 2727c50d8ae3SPaolo Bonzini gfn_t gfn; 2728c50d8ae3SPaolo Bonzini 2729c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt); 2730c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2731c50d8ae3SPaolo Bonzini if (!slot) 2732c50d8ae3SPaolo Bonzini return -1; 2733c50d8ae3SPaolo Bonzini 2734c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2735c50d8ae3SPaolo Bonzini if (ret <= 0) 2736c50d8ae3SPaolo Bonzini return -1; 2737c50d8ae3SPaolo Bonzini 2738c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 27398a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2740a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2741c50d8ae3SPaolo Bonzini put_page(pages[i]); 2742c50d8ae3SPaolo Bonzini } 2743c50d8ae3SPaolo Bonzini 2744c50d8ae3SPaolo Bonzini return 0; 2745c50d8ae3SPaolo Bonzini } 2746c50d8ae3SPaolo Bonzini 2747c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2748c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2749c50d8ae3SPaolo Bonzini { 2750c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2751c50d8ae3SPaolo Bonzini int i; 2752c50d8ae3SPaolo Bonzini 2753c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2754c50d8ae3SPaolo Bonzini 2755c50d8ae3SPaolo Bonzini i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); 2756c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2757c50d8ae3SPaolo Bonzini 2758c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2759c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2760c50d8ae3SPaolo Bonzini if (!start) 2761c50d8ae3SPaolo Bonzini continue; 2762c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2763c6cecc4bSSean Christopherson return; 2764c50d8ae3SPaolo Bonzini start = NULL; 2765c50d8ae3SPaolo Bonzini } else if (!start) 2766c50d8ae3SPaolo Bonzini start = spte; 2767c50d8ae3SPaolo Bonzini } 2768c6cecc4bSSean Christopherson if (start) 2769c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2770c50d8ae3SPaolo Bonzini } 2771c50d8ae3SPaolo Bonzini 2772c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2773c50d8ae3SPaolo Bonzini { 2774c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2775c50d8ae3SPaolo Bonzini 277657354682SSean Christopherson sp = sptep_to_sp(sptep); 2777c50d8ae3SPaolo Bonzini 2778c50d8ae3SPaolo Bonzini /* 2779c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2780c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2781c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2782c50d8ae3SPaolo Bonzini */ 2783c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2784c50d8ae3SPaolo Bonzini return; 2785c50d8ae3SPaolo Bonzini 27863bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2787c50d8ae3SPaolo Bonzini return; 2788c50d8ae3SPaolo Bonzini 27894a42d848SDavid Stevens /* 27904a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 27914a42d848SDavid Stevens * accidentally prefetching those addresses. 27924a42d848SDavid Stevens */ 27934a42d848SDavid Stevens if (unlikely(vcpu->kvm->mmu_notifier_count)) 27944a42d848SDavid Stevens return; 27954a42d848SDavid Stevens 2796c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2797c50d8ae3SPaolo Bonzini } 2798c50d8ae3SPaolo Bonzini 27991b6d9d9eSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, 28008ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2801db543216SSean Christopherson { 2802db543216SSean Christopherson unsigned long hva; 280344187235SMingwei Zhang unsigned long flags; 280444187235SMingwei Zhang int level = PG_LEVEL_4K; 280544187235SMingwei Zhang pgd_t pgd; 280644187235SMingwei Zhang p4d_t p4d; 280744187235SMingwei Zhang pud_t pud; 280844187235SMingwei Zhang pmd_t pmd; 2809db543216SSean Christopherson 2810e851265aSSean Christopherson if (!PageCompound(pfn_to_page(pfn)) && !kvm_is_zone_device_pfn(pfn)) 28113bae0459SSean Christopherson return PG_LEVEL_4K; 2812db543216SSean Christopherson 2813293e306eSSean Christopherson /* 2814293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2815293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2816293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2817293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2818293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2819293e306eSSean Christopherson * read-only memslot. 2820293e306eSSean Christopherson */ 2821db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2822db543216SSean Christopherson 282344187235SMingwei Zhang /* 282444187235SMingwei Zhang * Lookup the mapping level in the current mm. The information 282544187235SMingwei Zhang * may become stale soon, but it is safe to use as long as 282644187235SMingwei Zhang * 1) mmu_notifier_retry was checked after taking mmu_lock, and 282744187235SMingwei Zhang * 2) mmu_lock is taken now. 282844187235SMingwei Zhang * 282944187235SMingwei Zhang * We still need to disable IRQs to prevent concurrent tear down 283044187235SMingwei Zhang * of page tables. 283144187235SMingwei Zhang */ 283244187235SMingwei Zhang local_irq_save(flags); 2833db543216SSean Christopherson 283444187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 283544187235SMingwei Zhang if (pgd_none(pgd)) 283644187235SMingwei Zhang goto out; 283744187235SMingwei Zhang 283844187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 283944187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 284044187235SMingwei Zhang goto out; 284144187235SMingwei Zhang 284244187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 284344187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 284444187235SMingwei Zhang goto out; 284544187235SMingwei Zhang 284644187235SMingwei Zhang if (pud_large(pud)) { 284744187235SMingwei Zhang level = PG_LEVEL_1G; 284844187235SMingwei Zhang goto out; 284944187235SMingwei Zhang } 285044187235SMingwei Zhang 285144187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 285244187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 285344187235SMingwei Zhang goto out; 285444187235SMingwei Zhang 285544187235SMingwei Zhang if (pmd_large(pmd)) 285644187235SMingwei Zhang level = PG_LEVEL_2M; 285744187235SMingwei Zhang 285844187235SMingwei Zhang out: 285944187235SMingwei Zhang local_irq_restore(flags); 2860db543216SSean Christopherson return level; 2861db543216SSean Christopherson } 2862db543216SSean Christopherson 28638ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 28648ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 28658ca6f063SBen Gardon kvm_pfn_t pfn, int max_level) 28661b6d9d9eSSean Christopherson { 28671b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 2868ec607a56SPaolo Bonzini int host_level; 28691b6d9d9eSSean Christopherson 28701b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 28711b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 28721b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 28731b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 28741b6d9d9eSSean Christopherson break; 28751b6d9d9eSSean Christopherson } 28761b6d9d9eSSean Christopherson 28771b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 28781b6d9d9eSSean Christopherson return PG_LEVEL_4K; 28791b6d9d9eSSean Christopherson 2880ec607a56SPaolo Bonzini host_level = host_pfn_mapping_level(kvm, gfn, pfn, slot); 2881ec607a56SPaolo Bonzini return min(host_level, max_level); 28821b6d9d9eSSean Christopherson } 28831b6d9d9eSSean Christopherson 288473a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 28850885904dSSean Christopherson { 2886e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 288717eff019SSean Christopherson kvm_pfn_t mask; 28880885904dSSean Christopherson 288973a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 28903cf06612SSean Christopherson 289173a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 289273a3c659SPaolo Bonzini return; 289317eff019SSean Christopherson 289473a3c659SPaolo Bonzini if (is_error_noslot_pfn(fault->pfn) || kvm_is_reserved_pfn(fault->pfn)) 289573a3c659SPaolo Bonzini return; 289617eff019SSean Christopherson 2897e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 289873a3c659SPaolo Bonzini return; 2899293e306eSSean Christopherson 29003cf06612SSean Christopherson /* 29013cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 29023cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 29033cf06612SSean Christopherson */ 290473a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 290573a3c659SPaolo Bonzini fault->gfn, fault->pfn, 290673a3c659SPaolo Bonzini fault->max_level); 290773a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 290873a3c659SPaolo Bonzini return; 29094cd071d1SSean Christopherson 29100885904dSSean Christopherson /* 29114cd071d1SSean Christopherson * mmu_notifier_retry() was successful and mmu_lock is held, so 29124cd071d1SSean Christopherson * the pmd can't be split from under us. 29130885904dSSean Christopherson */ 291473a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 291573a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 291673a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 291773a3c659SPaolo Bonzini fault->pfn &= ~mask; 29180885904dSSean Christopherson } 29190885904dSSean Christopherson 2920536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 2921c50d8ae3SPaolo Bonzini { 2922536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 2923536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 2924c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 2925c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 2926c50d8ae3SPaolo Bonzini /* 2927c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 2928c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 2929c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 2930c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 2931c50d8ae3SPaolo Bonzini * the address. 2932c50d8ae3SPaolo Bonzini */ 2933536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 2934536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 2935536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 2936536f0e6aSPaolo Bonzini fault->goal_level--; 2937c50d8ae3SPaolo Bonzini } 2938c50d8ae3SPaolo Bonzini } 2939c50d8ae3SPaolo Bonzini 294043b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 2941c50d8ae3SPaolo Bonzini { 2942c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 2943c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 294473a3c659SPaolo Bonzini int ret; 294543b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 2946c50d8ae3SPaolo Bonzini 294773a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 29484cd071d1SSean Christopherson 2949f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 295043b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 2951c50d8ae3SPaolo Bonzini /* 2952c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 2953c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 2954c50d8ae3SPaolo Bonzini */ 295573a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 2956536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 2957c50d8ae3SPaolo Bonzini 295843b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 295973a3c659SPaolo Bonzini if (it.level == fault->goal_level) 2960c50d8ae3SPaolo Bonzini break; 2961c50d8ae3SPaolo Bonzini 2962c50d8ae3SPaolo Bonzini drop_large_spte(vcpu, it.sptep); 296303fffc54SSean Christopherson if (is_shadow_present_pte(*it.sptep)) 296403fffc54SSean Christopherson continue; 296503fffc54SSean Christopherson 2966c50d8ae3SPaolo Bonzini sp = kvm_mmu_get_page(vcpu, base_gfn, it.addr, 2967c50d8ae3SPaolo Bonzini it.level - 1, true, ACC_ALL); 2968c50d8ae3SPaolo Bonzini 2969c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 297073a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 297173a3c659SPaolo Bonzini fault->req_level >= it.level) 2972c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 2973c50d8ae3SPaolo Bonzini } 2974c50d8ae3SPaolo Bonzini 2975b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 2976b1a429fbSSean Christopherson return -EFAULT; 2977b1a429fbSSean Christopherson 29788a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 2979a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 298012703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 298112703759SSean Christopherson return ret; 298212703759SSean Christopherson 2983c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 2984c50d8ae3SPaolo Bonzini ++vcpu->stat.pf_fixed; 2985c50d8ae3SPaolo Bonzini return ret; 2986c50d8ae3SPaolo Bonzini } 2987c50d8ae3SPaolo Bonzini 2988c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 2989c50d8ae3SPaolo Bonzini { 2990c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 2991c50d8ae3SPaolo Bonzini } 2992c50d8ae3SPaolo Bonzini 2993c50d8ae3SPaolo Bonzini static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 2994c50d8ae3SPaolo Bonzini { 2995c50d8ae3SPaolo Bonzini /* 2996c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 2997c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 2998c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 2999c50d8ae3SPaolo Bonzini */ 3000c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3001c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3002c50d8ae3SPaolo Bonzini 3003c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3004c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3005c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3006c50d8ae3SPaolo Bonzini } 3007c50d8ae3SPaolo Bonzini 3008c50d8ae3SPaolo Bonzini return -EFAULT; 3009c50d8ae3SPaolo Bonzini } 3010c50d8ae3SPaolo Bonzini 30113a13f4feSPaolo Bonzini static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 30123a13f4feSPaolo Bonzini unsigned int access, int *ret_val) 3013c50d8ae3SPaolo Bonzini { 3014c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 30153a13f4feSPaolo Bonzini if (unlikely(is_error_pfn(fault->pfn))) { 30163a13f4feSPaolo Bonzini *ret_val = kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); 3017c50d8ae3SPaolo Bonzini return true; 3018c50d8ae3SPaolo Bonzini } 3019c50d8ae3SPaolo Bonzini 3020e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 30213a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 30223a13f4feSPaolo Bonzini 30233a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3024c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 302530ab5901SSean Christopherson /* 302630ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 302730ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 302886931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 302986931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 303086931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 303186931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 303286931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 303386931ff7SSean Christopherson * the hardware's). 303430ab5901SSean Christopherson */ 30358b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 303686931ff7SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) { 303730ab5901SSean Christopherson *ret_val = RET_PF_EMULATE; 303830ab5901SSean Christopherson return true; 303930ab5901SSean Christopherson } 304030ab5901SSean Christopherson } 3041c50d8ae3SPaolo Bonzini 3042c50d8ae3SPaolo Bonzini return false; 3043c50d8ae3SPaolo Bonzini } 3044c50d8ae3SPaolo Bonzini 30453c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3046c50d8ae3SPaolo Bonzini { 3047c50d8ae3SPaolo Bonzini /* 3048c50d8ae3SPaolo Bonzini * Do not fix the mmio spte with invalid generation number which 3049c50d8ae3SPaolo Bonzini * need to be updated by slow page fault path. 3050c50d8ae3SPaolo Bonzini */ 30513c8ad5a6SPaolo Bonzini if (fault->rsvd) 3052c50d8ae3SPaolo Bonzini return false; 3053c50d8ae3SPaolo Bonzini 3054c50d8ae3SPaolo Bonzini /* See if the page fault is due to an NX violation */ 30553c8ad5a6SPaolo Bonzini if (unlikely(fault->exec && fault->present)) 3056c50d8ae3SPaolo Bonzini return false; 3057c50d8ae3SPaolo Bonzini 3058c50d8ae3SPaolo Bonzini /* 3059c50d8ae3SPaolo Bonzini * #PF can be fast if: 3060c50d8ae3SPaolo Bonzini * 1. The shadow page table entry is not present, which could mean that 3061c50d8ae3SPaolo Bonzini * the fault is potentially caused by access tracking (if enabled). 3062c50d8ae3SPaolo Bonzini * 2. The shadow page table entry is present and the fault 3063c50d8ae3SPaolo Bonzini * is caused by write-protect, that means we just need change the W 3064c50d8ae3SPaolo Bonzini * bit of the spte which can be done out of mmu-lock. 3065c50d8ae3SPaolo Bonzini * 3066c50d8ae3SPaolo Bonzini * However, if access tracking is disabled we know that a non-present 3067c50d8ae3SPaolo Bonzini * page must be a genuine page fault where we have to create a new SPTE. 3068c50d8ae3SPaolo Bonzini * So, if access tracking is disabled, we return true only for write 3069c50d8ae3SPaolo Bonzini * accesses to a present page. 3070c50d8ae3SPaolo Bonzini */ 3071c50d8ae3SPaolo Bonzini 30723c8ad5a6SPaolo Bonzini return shadow_acc_track_mask != 0 || (fault->write && fault->present); 3073c50d8ae3SPaolo Bonzini } 3074c50d8ae3SPaolo Bonzini 3075c50d8ae3SPaolo Bonzini /* 3076c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3077c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3078c50d8ae3SPaolo Bonzini */ 3079c50d8ae3SPaolo Bonzini static bool 3080e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3081c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3082c50d8ae3SPaolo Bonzini { 3083c50d8ae3SPaolo Bonzini /* 3084c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3085c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3086c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3087c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3088c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3089c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3090c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3091c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3092c50d8ae3SPaolo Bonzini * 3093c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3094c50d8ae3SPaolo Bonzini */ 3095c50d8ae3SPaolo Bonzini if (cmpxchg64(sptep, old_spte, new_spte) != old_spte) 3096c50d8ae3SPaolo Bonzini return false; 3097c50d8ae3SPaolo Bonzini 3098e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3099e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3100c50d8ae3SPaolo Bonzini 3101c50d8ae3SPaolo Bonzini return true; 3102c50d8ae3SPaolo Bonzini } 3103c50d8ae3SPaolo Bonzini 31043c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3105c50d8ae3SPaolo Bonzini { 31063c8ad5a6SPaolo Bonzini if (fault->exec) 3107c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3108c50d8ae3SPaolo Bonzini 31093c8ad5a6SPaolo Bonzini if (fault->write) 3110c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3111c50d8ae3SPaolo Bonzini 3112c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3113c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3114c50d8ae3SPaolo Bonzini } 3115c50d8ae3SPaolo Bonzini 3116c50d8ae3SPaolo Bonzini /* 31176e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 31186e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 31196e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 31206e8eb206SDavid Matlack * 31216e8eb206SDavid Matlack * Contract: 31226e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 31236e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 31246e8eb206SDavid Matlack */ 31256e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 31266e8eb206SDavid Matlack { 31276e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 31286e8eb206SDavid Matlack u64 old_spte; 31296e8eb206SDavid Matlack u64 *sptep = NULL; 31306e8eb206SDavid Matlack 31316e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 31326e8eb206SDavid Matlack sptep = iterator.sptep; 31336e8eb206SDavid Matlack *spte = old_spte; 31346e8eb206SDavid Matlack } 31356e8eb206SDavid Matlack 31366e8eb206SDavid Matlack return sptep; 31376e8eb206SDavid Matlack } 31386e8eb206SDavid Matlack 31396e8eb206SDavid Matlack /* 3140c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3141c50d8ae3SPaolo Bonzini */ 31423c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3143c50d8ae3SPaolo Bonzini { 3144c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3145c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3146c50d8ae3SPaolo Bonzini u64 spte = 0ull; 31476e8eb206SDavid Matlack u64 *sptep = NULL; 3148c50d8ae3SPaolo Bonzini uint retry_count = 0; 3149c50d8ae3SPaolo Bonzini 31503c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3151c4371c2aSSean Christopherson return ret; 3152c50d8ae3SPaolo Bonzini 3153c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3154c50d8ae3SPaolo Bonzini 3155c50d8ae3SPaolo Bonzini do { 3156c50d8ae3SPaolo Bonzini u64 new_spte; 3157c50d8ae3SPaolo Bonzini 31586e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 31593c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 31606e8eb206SDavid Matlack else 31613c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3162c50d8ae3SPaolo Bonzini 3163ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3164ec89e643SSean Christopherson break; 3165ec89e643SSean Christopherson 31666e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3167c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3168c50d8ae3SPaolo Bonzini break; 3169c50d8ae3SPaolo Bonzini 3170c50d8ae3SPaolo Bonzini /* 3171c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3172c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3173c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3174c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3175c50d8ae3SPaolo Bonzini * current CPU took the fault. 3176c50d8ae3SPaolo Bonzini * 3177c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3178c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3179c50d8ae3SPaolo Bonzini */ 31803c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3181c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3182c50d8ae3SPaolo Bonzini break; 3183c50d8ae3SPaolo Bonzini } 3184c50d8ae3SPaolo Bonzini 3185c50d8ae3SPaolo Bonzini new_spte = spte; 3186c50d8ae3SPaolo Bonzini 3187c50d8ae3SPaolo Bonzini if (is_access_track_spte(spte)) 3188c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3189c50d8ae3SPaolo Bonzini 3190c50d8ae3SPaolo Bonzini /* 3191c50d8ae3SPaolo Bonzini * Currently, to simplify the code, write-protection can 3192c50d8ae3SPaolo Bonzini * be removed in the fast path only if the SPTE was 3193c50d8ae3SPaolo Bonzini * write-protected for dirty-logging or access tracking. 3194c50d8ae3SPaolo Bonzini */ 31953c8ad5a6SPaolo Bonzini if (fault->write && 3196e6302698SMiaohe Lin spte_can_locklessly_be_made_writable(spte)) { 3197c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3198c50d8ae3SPaolo Bonzini 3199c50d8ae3SPaolo Bonzini /* 320010c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 320110c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 320210c30de0SJunaid Shahid * first page into the dirty-bitmap in 3203c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3204c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3205c50d8ae3SPaolo Bonzini * 3206c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3207c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3208c50d8ae3SPaolo Bonzini */ 320910c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 321010c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3211c50d8ae3SPaolo Bonzini break; 3212c50d8ae3SPaolo Bonzini } 3213c50d8ae3SPaolo Bonzini 3214c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3215c50d8ae3SPaolo Bonzini if (new_spte == spte || 32163c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3217c50d8ae3SPaolo Bonzini break; 3218c50d8ae3SPaolo Bonzini 3219c50d8ae3SPaolo Bonzini /* 3220c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3221c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 32223ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3223c50d8ae3SPaolo Bonzini */ 3224e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3225c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3226c50d8ae3SPaolo Bonzini break; 3227c4371c2aSSean Christopherson } 3228c50d8ae3SPaolo Bonzini 3229c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3230c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3231c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3232c50d8ae3SPaolo Bonzini break; 3233c50d8ae3SPaolo Bonzini } 3234c50d8ae3SPaolo Bonzini 3235c50d8ae3SPaolo Bonzini } while (true); 3236c50d8ae3SPaolo Bonzini 3237f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3238c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3239c50d8ae3SPaolo Bonzini 3240c4371c2aSSean Christopherson return ret; 3241c50d8ae3SPaolo Bonzini } 3242c50d8ae3SPaolo Bonzini 3243c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3244c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3245c50d8ae3SPaolo Bonzini { 3246c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3247c50d8ae3SPaolo Bonzini 3248c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3249c50d8ae3SPaolo Bonzini return; 3250c50d8ae3SPaolo Bonzini 3251e47c4aeeSSean Christopherson sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK); 32529191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 32539191b8f0SPaolo Bonzini return; 325402c00b3aSBen Gardon 3255897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 32566103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 325776eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3258c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3259c50d8ae3SPaolo Bonzini 3260c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3261c50d8ae3SPaolo Bonzini } 3262c50d8ae3SPaolo Bonzini 3263c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 32640c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3265c50d8ae3SPaolo Bonzini ulong roots_to_free) 3266c50d8ae3SPaolo Bonzini { 3267c50d8ae3SPaolo Bonzini int i; 3268c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3269594bef79SPaolo Bonzini bool free_active_root; 3270c50d8ae3SPaolo Bonzini 3271c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3272c50d8ae3SPaolo Bonzini 3273c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3274594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3275594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3276594bef79SPaolo Bonzini 3277594bef79SPaolo Bonzini if (!free_active_root) { 3278c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3279c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3280c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3281c50d8ae3SPaolo Bonzini break; 3282c50d8ae3SPaolo Bonzini 3283c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3284c50d8ae3SPaolo Bonzini return; 3285c50d8ae3SPaolo Bonzini } 3286c50d8ae3SPaolo Bonzini 3287531810caSBen Gardon write_lock(&kvm->mmu_lock); 3288c50d8ae3SPaolo Bonzini 3289c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3290c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 32914d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3292c50d8ae3SPaolo Bonzini &invalid_list); 3293c50d8ae3SPaolo Bonzini 3294c50d8ae3SPaolo Bonzini if (free_active_root) { 3295594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3296b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 329704d45551SSean Christopherson } else if (mmu->pae_root) { 3298c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3299c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3300c834e5e4SSean Christopherson continue; 3301c834e5e4SSean Christopherson 3302c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3303c50d8ae3SPaolo Bonzini &invalid_list); 3304c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3305c50d8ae3SPaolo Bonzini } 3306c50d8ae3SPaolo Bonzini } 3307b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3308b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3309c50d8ae3SPaolo Bonzini } 3310c50d8ae3SPaolo Bonzini 33114d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3312531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3313c50d8ae3SPaolo Bonzini } 3314c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3315c50d8ae3SPaolo Bonzini 33160c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 331725b62c62SSean Christopherson { 331825b62c62SSean Christopherson unsigned long roots_to_free = 0; 331925b62c62SSean Christopherson hpa_t root_hpa; 332025b62c62SSean Christopherson int i; 332125b62c62SSean Christopherson 332225b62c62SSean Christopherson /* 332325b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 332425b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 332525b62c62SSean Christopherson */ 33267a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 332725b62c62SSean Christopherson 332825b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 332925b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 333025b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 333125b62c62SSean Christopherson continue; 333225b62c62SSean Christopherson 333325b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 333425b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 333525b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 333625b62c62SSean Christopherson } 333725b62c62SSean Christopherson 33380c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 333925b62c62SSean Christopherson } 334025b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 334125b62c62SSean Christopherson 334225b62c62SSean Christopherson 3343c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3344c50d8ae3SPaolo Bonzini { 3345c50d8ae3SPaolo Bonzini int ret = 0; 3346c50d8ae3SPaolo Bonzini 3347995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3348c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3349c50d8ae3SPaolo Bonzini ret = 1; 3350c50d8ae3SPaolo Bonzini } 3351c50d8ae3SPaolo Bonzini 3352c50d8ae3SPaolo Bonzini return ret; 3353c50d8ae3SPaolo Bonzini } 3354c50d8ae3SPaolo Bonzini 33558123f265SSean Christopherson static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva, 33568123f265SSean Christopherson u8 level, bool direct) 3357c50d8ae3SPaolo Bonzini { 3358c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 33598123f265SSean Christopherson 33608123f265SSean Christopherson sp = kvm_mmu_get_page(vcpu, gfn, gva, level, direct, ACC_ALL); 33618123f265SSean Christopherson ++sp->root_count; 33628123f265SSean Christopherson 33638123f265SSean Christopherson return __pa(sp->spt); 33648123f265SSean Christopherson } 33658123f265SSean Christopherson 33668123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 33678123f265SSean Christopherson { 3368b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3369b37233c9SSean Christopherson u8 shadow_root_level = mmu->shadow_root_level; 33708123f265SSean Christopherson hpa_t root; 3371c50d8ae3SPaolo Bonzini unsigned i; 33724a38162eSPaolo Bonzini int r; 33734a38162eSPaolo Bonzini 33744a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 33754a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 33764a38162eSPaolo Bonzini if (r < 0) 33774a38162eSPaolo Bonzini goto out_unlock; 3378c50d8ae3SPaolo Bonzini 3379897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 338002c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3381b9e5603cSPaolo Bonzini mmu->root.hpa = root; 338202c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 33836e6ec584SSean Christopherson root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true); 3384b9e5603cSPaolo Bonzini mmu->root.hpa = root; 33858123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 33864a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 33874a38162eSPaolo Bonzini r = -EIO; 33884a38162eSPaolo Bonzini goto out_unlock; 33894a38162eSPaolo Bonzini } 339073ad1606SSean Christopherson 3391c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3392c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3393c50d8ae3SPaolo Bonzini 33948123f265SSean Christopherson root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 33958123f265SSean Christopherson i << 30, PT32_ROOT_LEVEL, true); 339617e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 339717e368d9SSean Christopherson shadow_me_mask; 3398c50d8ae3SPaolo Bonzini } 3399b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 340073ad1606SSean Christopherson } else { 340173ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 34024a38162eSPaolo Bonzini r = -EIO; 34034a38162eSPaolo Bonzini goto out_unlock; 340473ad1606SSean Christopherson } 34053651c7fcSSean Christopherson 3406b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3407b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 34084a38162eSPaolo Bonzini out_unlock: 34094a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 34104a38162eSPaolo Bonzini return r; 3411c50d8ae3SPaolo Bonzini } 3412c50d8ae3SPaolo Bonzini 34131e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 34141e76a3ceSDavid Stevens { 34151e76a3ceSDavid Stevens struct kvm_memslots *slots; 34161e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3417a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 34181e76a3ceSDavid Stevens 34191e76a3ceSDavid Stevens /* 34201e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 34211e76a3ceSDavid Stevens * taking the lock. 34221e76a3ceSDavid Stevens */ 34231e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34241e76a3ceSDavid Stevens return 0; 34251e76a3ceSDavid Stevens 34261e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 34271e76a3ceSDavid Stevens 34281e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 34291e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34301e76a3ceSDavid Stevens goto out_unlock; 34311e76a3ceSDavid Stevens 34321e76a3ceSDavid Stevens /* 34331e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 34341e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 34351e76a3ceSDavid Stevens */ 34361e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 34371e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 34381e76a3ceSDavid Stevens goto out_success; 34391e76a3ceSDavid Stevens 34401e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 34411e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3442a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 34431e76a3ceSDavid Stevens /* 34441e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 34451e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 34461e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 34471e76a3ceSDavid Stevens * failure to avoid having to track which allocations 34481e76a3ceSDavid Stevens * were made now versus when the memslot was created. 34491e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 34501e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 34511e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 34521e76a3ceSDavid Stevens */ 34531e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 34541e76a3ceSDavid Stevens if (r) 34551e76a3ceSDavid Stevens goto out_unlock; 34561e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 34571e76a3ceSDavid Stevens if (r) 34581e76a3ceSDavid Stevens goto out_unlock; 34591e76a3ceSDavid Stevens } 34601e76a3ceSDavid Stevens } 34611e76a3ceSDavid Stevens 34621e76a3ceSDavid Stevens /* 34631e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 34641e76a3ceSDavid Stevens * all the related pointers are set. 34651e76a3ceSDavid Stevens */ 34661e76a3ceSDavid Stevens out_success: 34671e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 34681e76a3ceSDavid Stevens 34691e76a3ceSDavid Stevens out_unlock: 34701e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 34711e76a3ceSDavid Stevens return r; 34721e76a3ceSDavid Stevens } 34731e76a3ceSDavid Stevens 3474c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3475c50d8ae3SPaolo Bonzini { 3476b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 34776e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3478be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 34798123f265SSean Christopherson hpa_t root; 34804a38162eSPaolo Bonzini unsigned i; 34814a38162eSPaolo Bonzini int r; 3482c50d8ae3SPaolo Bonzini 3483b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3484be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3485c50d8ae3SPaolo Bonzini 3486c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3487c50d8ae3SPaolo Bonzini return 1; 3488c50d8ae3SPaolo Bonzini 3489c50d8ae3SPaolo Bonzini /* 34904a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 34914a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 34924a38162eSPaolo Bonzini */ 34936e0918aeSSean Christopherson if (mmu->root_level == PT32E_ROOT_LEVEL) { 34946e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 34956e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 34966e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 34976e0918aeSSean Christopherson continue; 34986e0918aeSSean Christopherson 34996e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 35006e0918aeSSean Christopherson return 1; 35016e0918aeSSean Christopherson } 35026e0918aeSSean Christopherson } 35036e0918aeSSean Christopherson 35041e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3505d501f747SBen Gardon if (r) 3506d501f747SBen Gardon return r; 3507d501f747SBen Gardon 35084a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35094a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35104a38162eSPaolo Bonzini if (r < 0) 35114a38162eSPaolo Bonzini goto out_unlock; 35124a38162eSPaolo Bonzini 3513c50d8ae3SPaolo Bonzini /* 3514c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3515c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3516c50d8ae3SPaolo Bonzini */ 3517b37233c9SSean Christopherson if (mmu->root_level >= PT64_ROOT_4LEVEL) { 35188123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 3519b37233c9SSean Christopherson mmu->shadow_root_level, false); 3520b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3521be01e8e2SSean Christopherson goto set_root_pgd; 3522c50d8ae3SPaolo Bonzini } 3523c50d8ae3SPaolo Bonzini 35244a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35254a38162eSPaolo Bonzini r = -EIO; 35264a38162eSPaolo Bonzini goto out_unlock; 35274a38162eSPaolo Bonzini } 352873ad1606SSean Christopherson 3529c50d8ae3SPaolo Bonzini /* 3530c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3531c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3532c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3533c50d8ae3SPaolo Bonzini */ 353417e368d9SSean Christopherson pm_mask = PT_PRESENT_MASK | shadow_me_mask; 3535cb0f722aSWei Huang if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL) { 3536c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3537c50d8ae3SPaolo Bonzini 353803ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 35394a38162eSPaolo Bonzini r = -EIO; 35404a38162eSPaolo Bonzini goto out_unlock; 35414a38162eSPaolo Bonzini } 354203ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3543cb0f722aSWei Huang 3544cb0f722aSWei Huang if (mmu->shadow_root_level == PT64_ROOT_5LEVEL) { 3545cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3546cb0f722aSWei Huang r = -EIO; 3547cb0f722aSWei Huang goto out_unlock; 3548cb0f722aSWei Huang } 3549cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3550cb0f722aSWei Huang } 355104d45551SSean Christopherson } 355204d45551SSean Christopherson 3553c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3554c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 35556e6ec584SSean Christopherson 3556b37233c9SSean Christopherson if (mmu->root_level == PT32E_ROOT_LEVEL) { 35576e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3558c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3559c50d8ae3SPaolo Bonzini continue; 3560c50d8ae3SPaolo Bonzini } 35616e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3562c50d8ae3SPaolo Bonzini } 3563c50d8ae3SPaolo Bonzini 35648123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, i << 30, 35658123f265SSean Christopherson PT32_ROOT_LEVEL, false); 3566b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3567c50d8ae3SPaolo Bonzini } 3568c50d8ae3SPaolo Bonzini 3569cb0f722aSWei Huang if (mmu->shadow_root_level == PT64_ROOT_5LEVEL) 3570b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3571cb0f722aSWei Huang else if (mmu->shadow_root_level == PT64_ROOT_4LEVEL) 3572b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3573ba0a194fSSean Christopherson else 3574b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3575c50d8ae3SPaolo Bonzini 3576be01e8e2SSean Christopherson set_root_pgd: 3577b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 35784a38162eSPaolo Bonzini out_unlock: 35794a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3580c50d8ae3SPaolo Bonzini 3581c6c937d6SLike Xu return r; 3582c50d8ae3SPaolo Bonzini } 3583c50d8ae3SPaolo Bonzini 3584748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3585c50d8ae3SPaolo Bonzini { 3586748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3587a717a780SSean Christopherson bool need_pml5 = mmu->shadow_root_level > PT64_ROOT_4LEVEL; 3588cb0f722aSWei Huang u64 *pml5_root = NULL; 3589cb0f722aSWei Huang u64 *pml4_root = NULL; 3590cb0f722aSWei Huang u64 *pae_root; 3591748e52b9SSean Christopherson 3592748e52b9SSean Christopherson /* 3593748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3594748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3595748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3596748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3597748e52b9SSean Christopherson */ 3598748e52b9SSean Christopherson if (mmu->direct_map || mmu->root_level >= PT64_ROOT_4LEVEL || 3599748e52b9SSean Christopherson mmu->shadow_root_level < PT64_ROOT_4LEVEL) 3600748e52b9SSean Christopherson return 0; 3601748e52b9SSean Christopherson 3602a717a780SSean Christopherson /* 3603a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3604a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3605a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3606a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3607a717a780SSean Christopherson * prior MMU would also have required pml5. 3608a717a780SSean Christopherson */ 3609a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3610748e52b9SSean Christopherson return 0; 3611748e52b9SSean Christopherson 3612748e52b9SSean Christopherson /* 3613748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3614748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3615748e52b9SSean Christopherson */ 3616cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3617a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3618748e52b9SSean Christopherson return -EIO; 3619748e52b9SSean Christopherson 36204a98623dSSean Christopherson /* 36214a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 36224a98623dSSean Christopherson * doesn't need to be decrypted. 36234a98623dSSean Christopherson */ 3624748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3625748e52b9SSean Christopherson if (!pae_root) 3626748e52b9SSean Christopherson return -ENOMEM; 3627748e52b9SSean Christopherson 3628cb0f722aSWei Huang #ifdef CONFIG_X86_64 362903ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3630cb0f722aSWei Huang if (!pml4_root) 3631cb0f722aSWei Huang goto err_pml4; 3632cb0f722aSWei Huang 3633a717a780SSean Christopherson if (need_pml5) { 3634cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3635cb0f722aSWei Huang if (!pml5_root) 3636cb0f722aSWei Huang goto err_pml5; 3637748e52b9SSean Christopherson } 3638cb0f722aSWei Huang #endif 3639748e52b9SSean Christopherson 3640748e52b9SSean Christopherson mmu->pae_root = pae_root; 364103ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3642cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3643748e52b9SSean Christopherson 3644748e52b9SSean Christopherson return 0; 3645cb0f722aSWei Huang 3646cb0f722aSWei Huang #ifdef CONFIG_X86_64 3647cb0f722aSWei Huang err_pml5: 3648cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3649cb0f722aSWei Huang err_pml4: 3650cb0f722aSWei Huang free_page((unsigned long)pae_root); 3651cb0f722aSWei Huang return -ENOMEM; 3652cb0f722aSWei Huang #endif 3653c50d8ae3SPaolo Bonzini } 3654c50d8ae3SPaolo Bonzini 3655264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3656264d3dc1SLai Jiangshan { 3657264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3658264d3dc1SLai Jiangshan 365961b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 366061b05a9fSLai Jiangshan return false; 366161b05a9fSLai Jiangshan 3662264d3dc1SLai Jiangshan /* 3663264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3664264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3665264d3dc1SLai Jiangshan * 3666264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3667264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3668264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3669264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3670264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3671264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3672264d3dc1SLai Jiangshan * requirement isn't satisfied. 3673264d3dc1SLai Jiangshan */ 3674264d3dc1SLai Jiangshan smp_rmb(); 3675264d3dc1SLai Jiangshan sp = to_shadow_page(root); 36765d6a3221SSean Christopherson 36775d6a3221SSean Christopherson /* 36785d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 36795d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 36805d6a3221SSean Christopherson */ 36815d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 36825d6a3221SSean Christopherson return false; 36835d6a3221SSean Christopherson 3684264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3685264d3dc1SLai Jiangshan return true; 3686264d3dc1SLai Jiangshan 3687264d3dc1SLai Jiangshan return false; 3688264d3dc1SLai Jiangshan } 3689264d3dc1SLai Jiangshan 3690c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3691c50d8ae3SPaolo Bonzini { 3692c50d8ae3SPaolo Bonzini int i; 3693c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3694c50d8ae3SPaolo Bonzini 3695c50d8ae3SPaolo Bonzini if (vcpu->arch.mmu->direct_map) 3696c50d8ae3SPaolo Bonzini return; 3697c50d8ae3SPaolo Bonzini 3698b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3699c50d8ae3SPaolo Bonzini return; 3700c50d8ae3SPaolo Bonzini 3701c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3702c50d8ae3SPaolo Bonzini 3703c50d8ae3SPaolo Bonzini if (vcpu->arch.mmu->root_level >= PT64_ROOT_4LEVEL) { 3704b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3705e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3706c50d8ae3SPaolo Bonzini 3707264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3708c50d8ae3SPaolo Bonzini return; 3709c50d8ae3SPaolo Bonzini 3710531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 371165855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3712531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3713c50d8ae3SPaolo Bonzini return; 3714c50d8ae3SPaolo Bonzini } 3715c50d8ae3SPaolo Bonzini 3716531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3717c50d8ae3SPaolo Bonzini 3718c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3719c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3720c50d8ae3SPaolo Bonzini 3721c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 3722c50d8ae3SPaolo Bonzini root &= PT64_BASE_ADDR_MASK; 3723e47c4aeeSSean Christopherson sp = to_shadow_page(root); 372465855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3725c50d8ae3SPaolo Bonzini } 3726c50d8ae3SPaolo Bonzini } 3727c50d8ae3SPaolo Bonzini 3728531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3729c50d8ae3SPaolo Bonzini } 3730c50d8ae3SPaolo Bonzini 373161b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 373261b05a9fSLai Jiangshan { 373361b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 373461b05a9fSLai Jiangshan int i; 373561b05a9fSLai Jiangshan 373661b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 373761b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 373861b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 373961b05a9fSLai Jiangshan 374061b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 37410c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 374261b05a9fSLai Jiangshan } 374361b05a9fSLai Jiangshan 37441f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 37455b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3746c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3747c50d8ae3SPaolo Bonzini { 3748c50d8ae3SPaolo Bonzini if (exception) 3749c50d8ae3SPaolo Bonzini exception->error_code = 0; 3750c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3751c50d8ae3SPaolo Bonzini } 3752c50d8ae3SPaolo Bonzini 3753c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3754c50d8ae3SPaolo Bonzini { 3755c50d8ae3SPaolo Bonzini /* 3756c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3757c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3758c50d8ae3SPaolo Bonzini */ 3759c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3760c50d8ae3SPaolo Bonzini return false; 3761c50d8ae3SPaolo Bonzini 3762c50d8ae3SPaolo Bonzini if (direct) 3763c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3764c50d8ae3SPaolo Bonzini 3765c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3766c50d8ae3SPaolo Bonzini } 3767c50d8ae3SPaolo Bonzini 376895fb5b02SBen Gardon /* 376995fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 377095fb5b02SBen Gardon * That SPTE may be non-present. 3771c5c8c7c5SDavid Matlack * 3772c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 377395fb5b02SBen Gardon */ 377439b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3775c50d8ae3SPaolo Bonzini { 3776c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 37772aa07893SSean Christopherson int leaf = -1; 377895fb5b02SBen Gardon u64 spte; 3779c50d8ae3SPaolo Bonzini 378039b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 378139b4d43eSSean Christopherson *root_level = iterator.level; 3782c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3783c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 378495fb5b02SBen Gardon leaf = iterator.level; 3785c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3786c50d8ae3SPaolo Bonzini 3787dde81f94SSean Christopherson sptes[leaf] = spte; 378895fb5b02SBen Gardon } 378995fb5b02SBen Gardon 379095fb5b02SBen Gardon return leaf; 379195fb5b02SBen Gardon } 379295fb5b02SBen Gardon 37939aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 379495fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 379595fb5b02SBen Gardon { 3796dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 379795fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 379839b4d43eSSean Christopherson int root, leaf, level; 379995fb5b02SBen Gardon bool reserved = false; 380095fb5b02SBen Gardon 3801c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3802c5c8c7c5SDavid Matlack 380363c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 380439b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 380595fb5b02SBen Gardon else 380639b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 380795fb5b02SBen Gardon 3808c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 3809c5c8c7c5SDavid Matlack 38102aa07893SSean Christopherson if (unlikely(leaf < 0)) { 38112aa07893SSean Christopherson *sptep = 0ull; 38122aa07893SSean Christopherson return reserved; 38132aa07893SSean Christopherson } 38142aa07893SSean Christopherson 38159aa41879SSean Christopherson *sptep = sptes[leaf]; 38169aa41879SSean Christopherson 38179aa41879SSean Christopherson /* 38189aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 38199aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 38209aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 38219aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 38229aa41879SSean Christopherson */ 38239aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 38249aa41879SSean Christopherson leaf++; 382595fb5b02SBen Gardon 382695fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 382795fb5b02SBen Gardon 38289aa41879SSean Christopherson for (level = root; level >= leaf; level--) 3829961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 3830c50d8ae3SPaolo Bonzini 3831c50d8ae3SPaolo Bonzini if (reserved) { 3832bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 3833c50d8ae3SPaolo Bonzini __func__, addr); 383495fb5b02SBen Gardon for (level = root; level >= leaf; level--) 3835bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 3836bb4cdf3aSSean Christopherson sptes[level], level, 3837961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 3838c50d8ae3SPaolo Bonzini } 3839ddce6208SSean Christopherson 3840c50d8ae3SPaolo Bonzini return reserved; 3841c50d8ae3SPaolo Bonzini } 3842c50d8ae3SPaolo Bonzini 3843c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3844c50d8ae3SPaolo Bonzini { 3845c50d8ae3SPaolo Bonzini u64 spte; 3846c50d8ae3SPaolo Bonzini bool reserved; 3847c50d8ae3SPaolo Bonzini 3848c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 3849c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3850c50d8ae3SPaolo Bonzini 385195fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 3852c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 3853c50d8ae3SPaolo Bonzini return -EINVAL; 3854c50d8ae3SPaolo Bonzini 3855c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 3856c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 38570a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 3858c50d8ae3SPaolo Bonzini 3859c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 3860c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 3861c50d8ae3SPaolo Bonzini 3862c50d8ae3SPaolo Bonzini if (direct) 3863c50d8ae3SPaolo Bonzini addr = 0; 3864c50d8ae3SPaolo Bonzini 3865c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 3866c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 3867c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3868c50d8ae3SPaolo Bonzini } 3869c50d8ae3SPaolo Bonzini 3870c50d8ae3SPaolo Bonzini /* 3871c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 3872c50d8ae3SPaolo Bonzini * the address. 3873c50d8ae3SPaolo Bonzini */ 3874c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3875c50d8ae3SPaolo Bonzini } 3876c50d8ae3SPaolo Bonzini 3877c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 3878b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 3879c50d8ae3SPaolo Bonzini { 3880b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 3881c50d8ae3SPaolo Bonzini return false; 3882c50d8ae3SPaolo Bonzini 3883b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 3884c50d8ae3SPaolo Bonzini return false; 3885c50d8ae3SPaolo Bonzini 3886c50d8ae3SPaolo Bonzini /* 3887c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 3888c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 3889c50d8ae3SPaolo Bonzini */ 38909d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 3891c50d8ae3SPaolo Bonzini return true; 3892c50d8ae3SPaolo Bonzini 3893c50d8ae3SPaolo Bonzini return false; 3894c50d8ae3SPaolo Bonzini } 3895c50d8ae3SPaolo Bonzini 3896c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 3897c50d8ae3SPaolo Bonzini { 3898c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 3899c50d8ae3SPaolo Bonzini u64 spte; 3900c50d8ae3SPaolo Bonzini 3901c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 39023e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 3903c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 3904c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3905c50d8ae3SPaolo Bonzini } 3906c50d8ae3SPaolo Bonzini 39076f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 39086f3c1fc5SLiang Zhang { 39096f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 39106f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 39116f3c1fc5SLiang Zhang 39126f3c1fc5SLiang Zhang if (id << 12 == 0) 39136f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 39146f3c1fc5SLiang Zhang 39156f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 39166f3c1fc5SLiang Zhang } 39176f3c1fc5SLiang Zhang 3918e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 39199f1a8526SSean Christopherson gfn_t gfn) 3920c50d8ae3SPaolo Bonzini { 3921c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 3922c50d8ae3SPaolo Bonzini 39236f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 3924c50d8ae3SPaolo Bonzini arch.gfn = gfn; 3925c50d8ae3SPaolo Bonzini arch.direct_map = vcpu->arch.mmu->direct_map; 3926d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 3927c50d8ae3SPaolo Bonzini 39289f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 39299f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 3930c50d8ae3SPaolo Bonzini } 3931c50d8ae3SPaolo Bonzini 39323647cd04SPaolo Bonzini static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, int *r) 3933c50d8ae3SPaolo Bonzini { 3934e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 3935c50d8ae3SPaolo Bonzini bool async; 3936c50d8ae3SPaolo Bonzini 3937e0c37868SSean Christopherson /* 3938e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 3939e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 3940e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 3941e0c37868SSean Christopherson */ 3942e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 39438f32d5e5SMaxim Levitsky goto out_retry; 3944e0c37868SSean Christopherson 39459cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 3946c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 39479cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 3948e710c5f6SDavid Matlack fault->slot = NULL; 39493647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 39503647cd04SPaolo Bonzini fault->map_writable = false; 3951c50d8ae3SPaolo Bonzini return false; 3952c50d8ae3SPaolo Bonzini } 39539cc13d60SMaxim Levitsky /* 39549cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 39559cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 39569cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 39579cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 39589cc13d60SMaxim Levitsky */ 39599cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 39609cc13d60SMaxim Levitsky !kvm_apicv_activated(vcpu->kvm)) { 39619cc13d60SMaxim Levitsky *r = RET_PF_EMULATE; 39629cc13d60SMaxim Levitsky return true; 39639cc13d60SMaxim Levitsky } 39649cc13d60SMaxim Levitsky } 3965c50d8ae3SPaolo Bonzini 3966c50d8ae3SPaolo Bonzini async = false; 39673647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, 39683647cd04SPaolo Bonzini fault->write, &fault->map_writable, 39693647cd04SPaolo Bonzini &fault->hva); 3970c50d8ae3SPaolo Bonzini if (!async) 3971c50d8ae3SPaolo Bonzini return false; /* *pfn has correct page already */ 3972c50d8ae3SPaolo Bonzini 39732839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 39743647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 39753647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 39763647cd04SPaolo Bonzini trace_kvm_async_pf_doublefault(fault->addr, fault->gfn); 3977c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 39788f32d5e5SMaxim Levitsky goto out_retry; 39793647cd04SPaolo Bonzini } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) 39808f32d5e5SMaxim Levitsky goto out_retry; 3981c50d8ae3SPaolo Bonzini } 3982c50d8ae3SPaolo Bonzini 39833647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, 39843647cd04SPaolo Bonzini fault->write, &fault->map_writable, 39853647cd04SPaolo Bonzini &fault->hva); 3986a7cc099fSAndrei Vagin return false; 39878f32d5e5SMaxim Levitsky 39888f32d5e5SMaxim Levitsky out_retry: 39898f32d5e5SMaxim Levitsky *r = RET_PF_RETRY; 39908f32d5e5SMaxim Levitsky return true; 3991c50d8ae3SPaolo Bonzini } 3992c50d8ae3SPaolo Bonzini 3993a955cad8SSean Christopherson /* 3994a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 3995a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 3996a955cad8SSean Christopherson */ 3997a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 3998a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 3999a955cad8SSean Christopherson { 4000b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 400118c841e1SSean Christopherson 400218c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 400318c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 400418c841e1SSean Christopherson return true; 400518c841e1SSean Christopherson 400618c841e1SSean Christopherson /* 400718c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 400818c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 400918c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 401018c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 401118c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 401218c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 401318c841e1SSean Christopherson */ 4014527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4015a955cad8SSean Christopherson return true; 4016a955cad8SSean Christopherson 4017a955cad8SSean Christopherson return fault->slot && 4018a955cad8SSean Christopherson mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4019a955cad8SSean Christopherson } 4020a955cad8SSean Christopherson 40214326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4022c50d8ae3SPaolo Bonzini { 402363c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4024c50d8ae3SPaolo Bonzini 40250f90e1c1SSean Christopherson unsigned long mmu_seq; 402683f06fa7SSean Christopherson int r; 4027c50d8ae3SPaolo Bonzini 40283c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4029e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4030e710c5f6SDavid Matlack 4031b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4032c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4033c50d8ae3SPaolo Bonzini 40343c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4035c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4036c4371c2aSSean Christopherson return r; 403783291445SSean Christopherson 4038378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4039c50d8ae3SPaolo Bonzini if (r) 4040c50d8ae3SPaolo Bonzini return r; 4041c50d8ae3SPaolo Bonzini 4042367fd790SSean Christopherson mmu_seq = vcpu->kvm->mmu_notifier_seq; 4043367fd790SSean Christopherson smp_rmb(); 4044367fd790SSean Christopherson 40453647cd04SPaolo Bonzini if (kvm_faultin_pfn(vcpu, fault, &r)) 40468f32d5e5SMaxim Levitsky return r; 4047367fd790SSean Christopherson 40483a13f4feSPaolo Bonzini if (handle_abnormal_pfn(vcpu, fault, ACC_ALL, &r)) 4049367fd790SSean Christopherson return r; 4050367fd790SSean Christopherson 4051367fd790SSean Christopherson r = RET_PF_RETRY; 4052a2855afcSBen Gardon 40530b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4054a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4055a2855afcSBen Gardon else 4056531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4057a2855afcSBen Gardon 4058a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4059367fd790SSean Christopherson goto out_unlock; 4060a955cad8SSean Christopherson 40617bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 40627bd7ded6SSean Christopherson if (r) 4063367fd790SSean Christopherson goto out_unlock; 4064bb18842eSBen Gardon 40650b873fd7SDavid Matlack if (is_tdp_mmu_fault) 40662f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4067bb18842eSBen Gardon else 406843b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 40690f90e1c1SSean Christopherson 4070367fd790SSean Christopherson out_unlock: 40710b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4072a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4073a2855afcSBen Gardon else 4074531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 40753647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4076367fd790SSean Christopherson return r; 4077c50d8ae3SPaolo Bonzini } 4078c50d8ae3SPaolo Bonzini 4079c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4080c501040aSPaolo Bonzini struct kvm_page_fault *fault) 40810f90e1c1SSean Christopherson { 40824326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 40830f90e1c1SSean Christopherson 40840f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 40854326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 40864326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 40870f90e1c1SSean Christopherson } 40880f90e1c1SSean Christopherson 4089c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4090c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4091c50d8ae3SPaolo Bonzini { 4092c50d8ae3SPaolo Bonzini int r = 1; 40939ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4094c50d8ae3SPaolo Bonzini 4095736c291cSSean Christopherson #ifndef CONFIG_X86_64 4096736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4097736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4098736c291cSSean Christopherson return -EFAULT; 4099736c291cSSean Christopherson #endif 4100736c291cSSean Christopherson 4101c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 41029ce372b3SVitaly Kuznetsov if (!flags) { 4103c50d8ae3SPaolo Bonzini trace_kvm_page_fault(fault_address, error_code); 4104c50d8ae3SPaolo Bonzini 4105c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4106c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4107c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4108c50d8ae3SPaolo Bonzini insn_len); 41099ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 411068fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4111c50d8ae3SPaolo Bonzini local_irq_disable(); 41126bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4113c50d8ae3SPaolo Bonzini local_irq_enable(); 41149ce372b3SVitaly Kuznetsov } else { 41159ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4116c50d8ae3SPaolo Bonzini } 41179ce372b3SVitaly Kuznetsov 4118c50d8ae3SPaolo Bonzini return r; 4119c50d8ae3SPaolo Bonzini } 4120c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4121c50d8ae3SPaolo Bonzini 4122c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4123c50d8ae3SPaolo Bonzini { 41244326e57eSPaolo Bonzini while (fault->max_level > PG_LEVEL_4K) { 41254326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 41264326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4127c50d8ae3SPaolo Bonzini 4128cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4129cb9b88c6SSean Christopherson break; 41304326e57eSPaolo Bonzini 41314326e57eSPaolo Bonzini --fault->max_level; 4132c50d8ae3SPaolo Bonzini } 4133c50d8ae3SPaolo Bonzini 41344326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4135c50d8ae3SPaolo Bonzini } 4136c50d8ae3SPaolo Bonzini 413784a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4138c50d8ae3SPaolo Bonzini { 4139c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4140c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4141c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 41425efac074SPaolo Bonzini context->invlpg = NULL; 4143c50d8ae3SPaolo Bonzini context->direct_map = true; 4144c50d8ae3SPaolo Bonzini } 4145c50d8ae3SPaolo Bonzini 4146be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 41470be44352SSean Christopherson union kvm_mmu_page_role role) 41480be44352SSean Christopherson { 4149be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 41505499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4151e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 41520be44352SSean Christopherson } 41530be44352SSean Christopherson 4154c50d8ae3SPaolo Bonzini /* 41555499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 41565499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 41575499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 41585499ea73SPaolo Bonzini * true is returned. 41595499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 41605499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4161c50d8ae3SPaolo Bonzini */ 41625499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 41635499ea73SPaolo Bonzini gpa_t new_pgd, 4164c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4165c50d8ae3SPaolo Bonzini { 4166c50d8ae3SPaolo Bonzini uint i; 4167c50d8ae3SPaolo Bonzini 4168b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 41690be44352SSean Christopherson return true; 41700be44352SSean Christopherson 4171c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 41725499ea73SPaolo Bonzini /* 41735499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 41745499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 41755499ea73SPaolo Bonzini * 0 C 1 2 3 41765499ea73SPaolo Bonzini * 1 C 0 2 3 41775499ea73SPaolo Bonzini * 2 C 0 1 3 41785499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 41795499ea73SPaolo Bonzini */ 4180b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4181b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 41825499ea73SPaolo Bonzini return true; 4183c50d8ae3SPaolo Bonzini } 4184c50d8ae3SPaolo Bonzini 41855499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 41865499ea73SPaolo Bonzini return false; 4187c50d8ae3SPaolo Bonzini } 4188c50d8ae3SPaolo Bonzini 4189c50d8ae3SPaolo Bonzini /* 41905499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 41915499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 41925499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 41935499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 41945499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 41955499ea73SPaolo Bonzini */ 41965499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 41975499ea73SPaolo Bonzini gpa_t new_pgd, 41985499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 41995499ea73SPaolo Bonzini { 42005499ea73SPaolo Bonzini uint i; 42015499ea73SPaolo Bonzini 42025499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 42035499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 42045499ea73SPaolo Bonzini goto hit; 42055499ea73SPaolo Bonzini 42065499ea73SPaolo Bonzini return false; 42075499ea73SPaolo Bonzini 42085499ea73SPaolo Bonzini hit: 42095499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 42105499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 42115499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 42125499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 42135499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 42145499ea73SPaolo Bonzini return true; 42155499ea73SPaolo Bonzini } 42165499ea73SPaolo Bonzini 42175499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 42185499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 42195499ea73SPaolo Bonzini { 42205499ea73SPaolo Bonzini /* 42215499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4222c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4223c50d8ae3SPaolo Bonzini * later if necessary. 4224c50d8ae3SPaolo Bonzini */ 42255499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 42265499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4227c50d8ae3SPaolo Bonzini 42285499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 42295499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 42305499ea73SPaolo Bonzini else 42315499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4232c50d8ae3SPaolo Bonzini } 4233c50d8ae3SPaolo Bonzini 4234d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4235c50d8ae3SPaolo Bonzini { 42360c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 42377a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 42380c1c92f1SPaolo Bonzini 42395499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 42405499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4241b869855bSSean Christopherson return; 4242c50d8ae3SPaolo Bonzini } 4243c50d8ae3SPaolo Bonzini 4244c50d8ae3SPaolo Bonzini /* 4245b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4246b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4247527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4248527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4249b869855bSSean Christopherson */ 4250b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4251b869855bSSean Christopherson 4252b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4253b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4254b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4255b5129100SSean Christopherson } 4256b869855bSSean Christopherson 4257b869855bSSean Christopherson /* 4258b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4259b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4260b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4261b869855bSSean Christopherson * the shadow page tables. 4262c50d8ae3SPaolo Bonzini */ 4263c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4264c50d8ae3SPaolo Bonzini 4265daa5b6c1SBen Gardon /* 4266daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4267daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4268daa5b6c1SBen Gardon */ 4269daa5b6c1SBen Gardon if (!new_role.direct) 4270daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4271b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4272c50d8ae3SPaolo Bonzini } 4273be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4274c50d8ae3SPaolo Bonzini 4275c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4276c50d8ae3SPaolo Bonzini { 4277c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4278c50d8ae3SPaolo Bonzini } 4279c50d8ae3SPaolo Bonzini 4280c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4281c3e5e415SLai Jiangshan unsigned int access) 4282c50d8ae3SPaolo Bonzini { 4283c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4284c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4285c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4286c50d8ae3SPaolo Bonzini return true; 4287c50d8ae3SPaolo Bonzini } 4288c50d8ae3SPaolo Bonzini 4289c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4290c50d8ae3SPaolo Bonzini return true; 4291c50d8ae3SPaolo Bonzini } 4292c50d8ae3SPaolo Bonzini 4293c50d8ae3SPaolo Bonzini return false; 4294c50d8ae3SPaolo Bonzini } 4295c50d8ae3SPaolo Bonzini 4296c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4297c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4298c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4299c50d8ae3SPaolo Bonzini #undef PTTYPE 4300c50d8ae3SPaolo Bonzini 4301c50d8ae3SPaolo Bonzini #define PTTYPE 64 4302c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4303c50d8ae3SPaolo Bonzini #undef PTTYPE 4304c50d8ae3SPaolo Bonzini 4305c50d8ae3SPaolo Bonzini #define PTTYPE 32 4306c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4307c50d8ae3SPaolo Bonzini #undef PTTYPE 4308c50d8ae3SPaolo Bonzini 4309c50d8ae3SPaolo Bonzini static void 4310b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 43115b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4312c50d8ae3SPaolo Bonzini bool pse, bool amd) 4313c50d8ae3SPaolo Bonzini { 4314c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4315c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 43165b7f575cSSean Christopherson u64 high_bits_rsvd; 4317c50d8ae3SPaolo Bonzini 4318c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4319c50d8ae3SPaolo Bonzini 4320c50d8ae3SPaolo Bonzini if (!gbpages) 4321c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4322c50d8ae3SPaolo Bonzini 43235b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 43245b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 43255b7f575cSSean Christopherson else 43265b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 43275b7f575cSSean Christopherson 43285b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 43295b7f575cSSean Christopherson if (!nx) 43305b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 43315b7f575cSSean Christopherson 4332c50d8ae3SPaolo Bonzini /* 4333c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4334c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4335c50d8ae3SPaolo Bonzini */ 4336c50d8ae3SPaolo Bonzini if (amd) 4337c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4338c50d8ae3SPaolo Bonzini 4339c50d8ae3SPaolo Bonzini switch (level) { 4340c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4341c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4342c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4343c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4344c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4345c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4346c50d8ae3SPaolo Bonzini 4347c50d8ae3SPaolo Bonzini if (!pse) { 4348c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4349c50d8ae3SPaolo Bonzini break; 4350c50d8ae3SPaolo Bonzini } 4351c50d8ae3SPaolo Bonzini 4352c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4353c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4354c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4355c50d8ae3SPaolo Bonzini else 4356c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4357c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4358c50d8ae3SPaolo Bonzini break; 4359c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 43605b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 43615b7f575cSSean Christopherson high_bits_rsvd | 43625b7f575cSSean Christopherson rsvd_bits(5, 8) | 43635b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 43645b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 43655b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 43665b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4367c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4368c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4369c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4370c50d8ae3SPaolo Bonzini break; 4371c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 43725b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 43735b7f575cSSean Christopherson nonleaf_bit8_rsvd | 43745b7f575cSSean Christopherson rsvd_bits(7, 7); 4375c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4376c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4377df561f66SGustavo A. R. Silva fallthrough; 4378c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 43795b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 43805b7f575cSSean Christopherson nonleaf_bit8_rsvd | 43815b7f575cSSean Christopherson rsvd_bits(7, 7); 43825b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 43835b7f575cSSean Christopherson gbpages_bit_rsvd; 43845b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 43855b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4386c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4387c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 43885b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 43895b7f575cSSean Christopherson gbpages_bit_rsvd | 4390c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 43915b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4392c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4393c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4394c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4395c50d8ae3SPaolo Bonzini break; 4396c50d8ae3SPaolo Bonzini } 4397c50d8ae3SPaolo Bonzini } 4398c50d8ae3SPaolo Bonzini 439927de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 440027de9250SSean Christopherson { 440127de9250SSean Christopherson /* 440227de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 440327de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 440427de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 440527de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 440627de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 440727de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 440827de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 440927de9250SSean Christopherson */ 441027de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 441127de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 441227de9250SSean Christopherson } 441327de9250SSean Christopherson 4414c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4415c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4416c50d8ae3SPaolo Bonzini { 4417b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 44185b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 441990599c28SSean Christopherson context->root_level, is_efer_nx(context), 442027de9250SSean Christopherson guest_can_use_gbpages(vcpu), 44214e9c0d80SSean Christopherson is_cr4_pse(context), 442223493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4423c50d8ae3SPaolo Bonzini } 4424c50d8ae3SPaolo Bonzini 4425c50d8ae3SPaolo Bonzini static void 4426c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 442784ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4428c50d8ae3SPaolo Bonzini { 44295b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 443084ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4431c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4432c50d8ae3SPaolo Bonzini 443384ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 443484ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 443584ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 443684ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 443784ea5c09SLai Jiangshan 44385b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 44395b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 444084ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 444184ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 44425b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4443c50d8ae3SPaolo Bonzini 4444c50d8ae3SPaolo Bonzini /* large page */ 4445c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4446c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 444784ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 444884ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4449c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4450c50d8ae3SPaolo Bonzini 4451c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4452c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4453c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4454c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4455c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4456c50d8ae3SPaolo Bonzini if (!execonly) { 4457c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4458c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4459c50d8ae3SPaolo Bonzini } 4460c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4461c50d8ae3SPaolo Bonzini } 4462c50d8ae3SPaolo Bonzini 4463c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 446484ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4465c50d8ae3SPaolo Bonzini { 4466c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 446784ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 446884ea5c09SLai Jiangshan huge_page_level); 4469c50d8ae3SPaolo Bonzini } 4470c50d8ae3SPaolo Bonzini 44716f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 44726f8e65a6SSean Christopherson { 44736f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 44746f8e65a6SSean Christopherson } 44756f8e65a6SSean Christopherson 4476c50d8ae3SPaolo Bonzini /* 4477c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4478c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4479c50d8ae3SPaolo Bonzini * follow the features in guest. 4480c50d8ae3SPaolo Bonzini */ 448116be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 448216be1d12SSean Christopherson struct kvm_mmu *context) 4483c50d8ae3SPaolo Bonzini { 44848c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 44858c985b2dSSean Christopherson bool is_amd = true; 44868c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 44878c985b2dSSean Christopherson bool is_pse = false; 4488c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4489c50d8ae3SPaolo Bonzini int i; 4490c50d8ae3SPaolo Bonzini 44918c985b2dSSean Christopherson WARN_ON_ONCE(context->shadow_root_level < PT32E_ROOT_LEVEL); 44928c985b2dSSean Christopherson 4493c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4494b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4495362505deSPaolo Bonzini context->shadow_root_level, 44967a458f0eSPaolo Bonzini context->root_role.efer_nx, 449727de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4498c50d8ae3SPaolo Bonzini 4499c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4500c50d8ae3SPaolo Bonzini return; 4501c50d8ae3SPaolo Bonzini 4502c50d8ae3SPaolo Bonzini for (i = context->shadow_root_level; --i >= 0;) { 4503c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4504c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4505c50d8ae3SPaolo Bonzini } 4506c50d8ae3SPaolo Bonzini 4507c50d8ae3SPaolo Bonzini } 4508c50d8ae3SPaolo Bonzini 4509c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4510c50d8ae3SPaolo Bonzini { 4511c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4512c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4513c50d8ae3SPaolo Bonzini } 4514c50d8ae3SPaolo Bonzini 4515c50d8ae3SPaolo Bonzini /* 4516c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4517c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4518c50d8ae3SPaolo Bonzini */ 4519c50d8ae3SPaolo Bonzini static void 4520e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4521c50d8ae3SPaolo Bonzini { 4522c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4523c50d8ae3SPaolo Bonzini int i; 4524c50d8ae3SPaolo Bonzini 4525c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4526c50d8ae3SPaolo Bonzini 4527c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4528b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4529c50d8ae3SPaolo Bonzini context->shadow_root_level, false, 4530c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 45318c985b2dSSean Christopherson false, true); 4532c50d8ae3SPaolo Bonzini else 4533c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 453484ea5c09SLai Jiangshan reserved_hpa_bits(), false, 453584ea5c09SLai Jiangshan max_huge_page_level); 4536c50d8ae3SPaolo Bonzini 4537c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4538c50d8ae3SPaolo Bonzini return; 4539c50d8ae3SPaolo Bonzini 4540c50d8ae3SPaolo Bonzini for (i = context->shadow_root_level; --i >= 0;) { 4541c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4542c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4543c50d8ae3SPaolo Bonzini } 4544c50d8ae3SPaolo Bonzini } 4545c50d8ae3SPaolo Bonzini 4546c50d8ae3SPaolo Bonzini /* 4547c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4548c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4549c50d8ae3SPaolo Bonzini */ 4550c50d8ae3SPaolo Bonzini static void 4551e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4552c50d8ae3SPaolo Bonzini { 4553c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 455484ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 455584ea5c09SLai Jiangshan max_huge_page_level); 4556c50d8ae3SPaolo Bonzini } 4557c50d8ae3SPaolo Bonzini 4558c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4559c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4560c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4561c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4562c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4563c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4564c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4565c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4566c50d8ae3SPaolo Bonzini 4567c50d8ae3SPaolo Bonzini 4568c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4569c50d8ae3SPaolo Bonzini { 4570c50d8ae3SPaolo Bonzini unsigned byte; 4571c50d8ae3SPaolo Bonzini 4572c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4573c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4574c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4575c50d8ae3SPaolo Bonzini 4576c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4577c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4578c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 457990599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4580c50d8ae3SPaolo Bonzini 4581c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4582c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4583c50d8ae3SPaolo Bonzini 4584c50d8ae3SPaolo Bonzini /* 4585c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4586c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4587c50d8ae3SPaolo Bonzini */ 4588c50d8ae3SPaolo Bonzini 4589c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4590c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4591c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4592c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4593c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4594c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4595c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4596c50d8ae3SPaolo Bonzini u8 smepf = 0; 4597c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4598c50d8ae3SPaolo Bonzini u8 smapf = 0; 4599c50d8ae3SPaolo Bonzini 4600c50d8ae3SPaolo Bonzini if (!ept) { 4601c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4602c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4603c50d8ae3SPaolo Bonzini 4604c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 460590599c28SSean Christopherson if (!efer_nx) 4606c50d8ae3SPaolo Bonzini ff = 0; 4607c50d8ae3SPaolo Bonzini 4608c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4609c50d8ae3SPaolo Bonzini if (!cr0_wp) 4610c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4611c50d8ae3SPaolo Bonzini 4612c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4613c50d8ae3SPaolo Bonzini if (cr4_smep) 4614c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4615c50d8ae3SPaolo Bonzini 4616c50d8ae3SPaolo Bonzini /* 4617c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4618c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4619c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4620c50d8ae3SPaolo Bonzini * conditions are true: 4621c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4622c50d8ae3SPaolo Bonzini * - A user page is accessed 4623c50d8ae3SPaolo Bonzini * - The access is not a fetch 46244f4aa80eSLai Jiangshan * - The access is supervisor mode 46254f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4626c50d8ae3SPaolo Bonzini * 462794b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 462894b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4629c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4630c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4631c50d8ae3SPaolo Bonzini */ 4632c50d8ae3SPaolo Bonzini if (cr4_smap) 4633c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4634c50d8ae3SPaolo Bonzini } 4635c50d8ae3SPaolo Bonzini 4636c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4637c50d8ae3SPaolo Bonzini } 4638c50d8ae3SPaolo Bonzini } 4639c50d8ae3SPaolo Bonzini 4640c50d8ae3SPaolo Bonzini /* 4641c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4642c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4643c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4644c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4645c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4646c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4647c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4648c50d8ae3SPaolo Bonzini * 4649c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4650c50d8ae3SPaolo Bonzini * page tables and the machine state: 4651c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4652c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4653c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4654c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4655c50d8ae3SPaolo Bonzini * 4656c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4657c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4658c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4659c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4660c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4661c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4662c50d8ae3SPaolo Bonzini * only will be masked away. 4663c50d8ae3SPaolo Bonzini */ 46642e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4665c50d8ae3SPaolo Bonzini { 4666c50d8ae3SPaolo Bonzini unsigned bit; 4667c50d8ae3SPaolo Bonzini bool wp; 4668c50d8ae3SPaolo Bonzini 4669c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4670a3ca5281SChenyi Qiang 4671a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4672c50d8ae3SPaolo Bonzini return; 4673c50d8ae3SPaolo Bonzini 46742e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4675c50d8ae3SPaolo Bonzini 4676c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4677c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4678c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4679c50d8ae3SPaolo Bonzini 4680c50d8ae3SPaolo Bonzini pfec = bit << 1; 4681c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4682c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4683c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4684c50d8ae3SPaolo Bonzini 4685c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4686c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4687c50d8ae3SPaolo Bonzini 4688c50d8ae3SPaolo Bonzini /* 4689c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4690c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4691c50d8ae3SPaolo Bonzini */ 4692c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4693c50d8ae3SPaolo Bonzini /* 4694c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4695c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4696c50d8ae3SPaolo Bonzini */ 4697c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4698c50d8ae3SPaolo Bonzini 4699c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4700c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4701c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4702c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4703c50d8ae3SPaolo Bonzini 4704c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4705c50d8ae3SPaolo Bonzini } 4706c50d8ae3SPaolo Bonzini } 4707c50d8ae3SPaolo Bonzini 4708533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4709533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4710c50d8ae3SPaolo Bonzini { 4711533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4712533f9a4bSSean Christopherson return; 4713c50d8ae3SPaolo Bonzini 4714533f9a4bSSean Christopherson reset_rsvds_bits_mask(vcpu, mmu); 4715533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4716533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4717c50d8ae3SPaolo Bonzini } 4718c50d8ae3SPaolo Bonzini 4719fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4720c50d8ae3SPaolo Bonzini { 4721c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4722c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4723c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4724c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4725c50d8ae3SPaolo Bonzini context->direct_map = false; 4726c50d8ae3SPaolo Bonzini } 4727c50d8ae3SPaolo Bonzini 472884a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4729c50d8ae3SPaolo Bonzini { 4730c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4731c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4732c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4733c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4734c50d8ae3SPaolo Bonzini context->direct_map = false; 4735c50d8ae3SPaolo Bonzini } 4736c50d8ae3SPaolo Bonzini 47377a7ae829SPaolo Bonzini static union kvm_cpu_role 4738e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 4739e5ed0fb0SPaolo Bonzini { 47407a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4741e5ed0fb0SPaolo Bonzini 4742e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 4743e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 4744e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4745e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 4746e5ed0fb0SPaolo Bonzini 4747e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 4748e5ed0fb0SPaolo Bonzini role.base.direct = 1; 4749e5ed0fb0SPaolo Bonzini return role; 4750e5ed0fb0SPaolo Bonzini } 4751e5ed0fb0SPaolo Bonzini 4752e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 4753e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 4754e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 4755e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 4756e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 475760f3cb60SPaolo Bonzini 475860f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 475960f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 476060f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 476160f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 476260f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 476360f3cb60SPaolo Bonzini else 476460f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 4765e5ed0fb0SPaolo Bonzini 4766e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 4767e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 4768e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 4769e5ed0fb0SPaolo Bonzini 4770e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 4771e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 4772e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 4773e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 4774e5ed0fb0SPaolo Bonzini return role; 4775e5ed0fb0SPaolo Bonzini } 4776e5ed0fb0SPaolo Bonzini 4777d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 4778d468d94bSSean Christopherson { 4779746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 4780746700d2SWei Huang if (tdp_root_level) 4781746700d2SWei Huang return tdp_root_level; 4782746700d2SWei Huang 4783d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 478483013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 4785d468d94bSSean Christopherson return 4; 4786d468d94bSSean Christopherson 478783013059SSean Christopherson return max_tdp_level; 4788d468d94bSSean Christopherson } 4789d468d94bSSean Christopherson 47907a458f0eSPaolo Bonzini static union kvm_mmu_page_role 47918626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 47927a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 4793c50d8ae3SPaolo Bonzini { 47947a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 4795c50d8ae3SPaolo Bonzini 47967a458f0eSPaolo Bonzini role.access = ACC_ALL; 47977a458f0eSPaolo Bonzini role.cr0_wp = true; 47987a458f0eSPaolo Bonzini role.efer_nx = true; 47997a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 48007a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 48017a458f0eSPaolo Bonzini role.ad_disabled = (shadow_accessed_mask == 0); 48027a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 48037a458f0eSPaolo Bonzini role.direct = true; 48047a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 4805c50d8ae3SPaolo Bonzini 4806c50d8ae3SPaolo Bonzini return role; 4807c50d8ae3SPaolo Bonzini } 4808c50d8ae3SPaolo Bonzini 480939e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 481039e7e2bfSPaolo Bonzini const struct kvm_mmu_role_regs *regs) 4811c50d8ae3SPaolo Bonzini { 48128c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 48137a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, regs); 48147a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 4815c50d8ae3SPaolo Bonzini 4816e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 48177a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 4818c50d8ae3SPaolo Bonzini return; 4819c50d8ae3SPaolo Bonzini 4820e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 48217a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 48227a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 4823c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 48245efac074SPaolo Bonzini context->invlpg = NULL; 4825d468d94bSSean Christopherson context->shadow_root_level = kvm_mmu_get_tdp_level(vcpu); 4826c50d8ae3SPaolo Bonzini context->direct_map = true; 4827d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4828c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4829c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 483060f3cb60SPaolo Bonzini context->root_level = cpu_role.base.level; 4831c50d8ae3SPaolo Bonzini 483236f26787SSean Christopherson if (!is_cr0_pg(context)) 4833c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 483436f26787SSean Christopherson else if (is_cr4_pae(context)) 4835c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4836f4bd6f73SSean Christopherson else 4837c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4838c50d8ae3SPaolo Bonzini 4839533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4840e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 4841c50d8ae3SPaolo Bonzini } 4842c50d8ae3SPaolo Bonzini 48437a458f0eSPaolo Bonzini static union kvm_mmu_page_role 48448626c120SSean Christopherson kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, 48457a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 484659505b55SSean Christopherson { 48477a458f0eSPaolo Bonzini union kvm_mmu_page_role role; 484859505b55SSean Christopherson 48497a458f0eSPaolo Bonzini role = cpu_role.base; 4850f417e145SPaolo Bonzini if (!cpu_role.ext.efer_lma) 48517a458f0eSPaolo Bonzini role.level = PT32E_ROOT_LEVEL; 4852f417e145SPaolo Bonzini else if (cpu_role.ext.cr4_la57) 48537a458f0eSPaolo Bonzini role.level = PT64_ROOT_5LEVEL; 4854c50d8ae3SPaolo Bonzini else 48557a458f0eSPaolo Bonzini role.level = PT64_ROOT_4LEVEL; 4856c50d8ae3SPaolo Bonzini 4857362505deSPaolo Bonzini /* 4858362505deSPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 4859362505deSPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 4860362505deSPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 4861362505deSPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 4862362505deSPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 4863362505deSPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 4864362505deSPaolo Bonzini * MMU contexts. 4865362505deSPaolo Bonzini */ 48667a458f0eSPaolo Bonzini role.efer_nx = true; 4867c50d8ae3SPaolo Bonzini return role; 4868c50d8ae3SPaolo Bonzini } 4869c50d8ae3SPaolo Bonzini 48708c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 48717a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 48727a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 4873c50d8ae3SPaolo Bonzini { 4874e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 48757a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 487618db1b17SSean Christopherson return; 4877c50d8ae3SPaolo Bonzini 4878e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 48797a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 488018db1b17SSean Christopherson 488136f26787SSean Christopherson if (!is_cr0_pg(context)) 488284a16226SSean Christopherson nonpaging_init_context(context); 488336f26787SSean Christopherson else if (is_cr4_pae(context)) 4884fe660f72SSean Christopherson paging64_init_context(context); 4885c50d8ae3SPaolo Bonzini else 488684a16226SSean Christopherson paging32_init_context(context); 4887e5ed0fb0SPaolo Bonzini context->root_level = cpu_role.base.level; 4888c50d8ae3SPaolo Bonzini 4889533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 48907a458f0eSPaolo Bonzini context->shadow_root_level = root_role.level; 4891d555f705SSean Christopherson 4892c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 4893c50d8ae3SPaolo Bonzini } 48940f04a2acSVitaly Kuznetsov 4895594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 489682ffa13fSPaolo Bonzini const struct kvm_mmu_role_regs *regs) 48970f04a2acSVitaly Kuznetsov { 48988c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 48997a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, regs); 49007a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = 4901f417e145SPaolo Bonzini kvm_calc_shadow_mmu_root_page_role(vcpu, cpu_role); 49020f04a2acSVitaly Kuznetsov 49037a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 49040f04a2acSVitaly Kuznetsov } 49050f04a2acSVitaly Kuznetsov 49067a458f0eSPaolo Bonzini static union kvm_mmu_page_role 49078626c120SSean Christopherson kvm_calc_shadow_npt_root_page_role(struct kvm_vcpu *vcpu, 49087a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 490959505b55SSean Christopherson { 49107a458f0eSPaolo Bonzini union kvm_mmu_page_role role; 491159505b55SSean Christopherson 491219b5dcc3SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 49137a458f0eSPaolo Bonzini role = cpu_role.base; 49147a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 491559505b55SSean Christopherson return role; 491659505b55SSean Christopherson } 491759505b55SSean Christopherson 4918dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 4919dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 49200f04a2acSVitaly Kuznetsov { 49218c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4922594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 4923594e91a1SSean Christopherson .cr0 = cr0, 492428f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 4925594e91a1SSean Christopherson .efer = efer, 4926594e91a1SSean Christopherson }; 49277a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 49287a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_shadow_npt_root_page_role(vcpu, cpu_role); 49290f04a2acSVitaly Kuznetsov 49307a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 4931d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 49320f04a2acSVitaly Kuznetsov } 49330f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 4934c50d8ae3SPaolo Bonzini 49357a7ae829SPaolo Bonzini static union kvm_cpu_role 4936c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 4937bb1fcc70SSean Christopherson bool execonly, u8 level) 4938c50d8ae3SPaolo Bonzini { 49397a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4940c50d8ae3SPaolo Bonzini 4941daed87b8SPaolo Bonzini /* 4942daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 4943daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 4944daed87b8SPaolo Bonzini */ 4945daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 4946bb1fcc70SSean Christopherson role.base.level = level; 4947bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 4948c50d8ae3SPaolo Bonzini role.base.direct = false; 4949c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 4950c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 4951c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 4952c50d8ae3SPaolo Bonzini 4953cd6767c3SSean Christopherson role.ext.word = 0; 4954c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 4955cd6767c3SSean Christopherson role.ext.valid = 1; 4956c50d8ae3SPaolo Bonzini 4957c50d8ae3SPaolo Bonzini return role; 4958c50d8ae3SPaolo Bonzini } 4959c50d8ae3SPaolo Bonzini 4960c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 4961cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 4962cc022ae1SLai Jiangshan gpa_t new_eptp) 4963c50d8ae3SPaolo Bonzini { 49648c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4965bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 49667a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 4967c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 4968bb1fcc70SSean Christopherson execonly, level); 4969c50d8ae3SPaolo Bonzini 4970e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 4971e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 4972e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 49737a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 497418db1b17SSean Christopherson 4975bb1fcc70SSean Christopherson context->shadow_root_level = level; 4976c50d8ae3SPaolo Bonzini 4977c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 4978c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 4979c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 4980c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 4981bb1fcc70SSean Christopherson context->root_level = level; 4982c50d8ae3SPaolo Bonzini context->direct_map = false; 4983c596f147SSean Christopherson update_permission_bitmask(context, true); 498428f091bcSPaolo Bonzini context->pkru_mask = 0; 4985cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 4986e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 4987c50d8ae3SPaolo Bonzini } 49883cffc89dSPaolo Bonzini 4989d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 49903cffc89dSPaolo Bonzini } 4991c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 4992c50d8ae3SPaolo Bonzini 499339e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 499439e7e2bfSPaolo Bonzini const struct kvm_mmu_role_regs *regs) 4995c50d8ae3SPaolo Bonzini { 49968c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 4997c50d8ae3SPaolo Bonzini 499839e7e2bfSPaolo Bonzini kvm_init_shadow_mmu(vcpu, regs); 4999929d1cfaSPaolo Bonzini 5000d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5001c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5002c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5003c50d8ae3SPaolo Bonzini } 5004c50d8ae3SPaolo Bonzini 500539e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 500639e7e2bfSPaolo Bonzini const struct kvm_mmu_role_regs *regs) 5007c50d8ae3SPaolo Bonzini { 50087a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = kvm_calc_cpu_role(vcpu, regs); 5009c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5010c50d8ae3SPaolo Bonzini 5011e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5012c50d8ae3SPaolo Bonzini return; 5013c50d8ae3SPaolo Bonzini 5014e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5015d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5016c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5017c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5018e5ed0fb0SPaolo Bonzini g_context->root_level = new_mode.base.level; 5019c50d8ae3SPaolo Bonzini 5020c50d8ae3SPaolo Bonzini /* 50215efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 50225efac074SPaolo Bonzini * SPTEs. 50235efac074SPaolo Bonzini */ 50245efac074SPaolo Bonzini g_context->invlpg = NULL; 50255efac074SPaolo Bonzini 50265efac074SPaolo Bonzini /* 5027c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5028c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5029c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5030c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5031c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5032c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5033c50d8ae3SPaolo Bonzini */ 5034fa4b5588SSean Christopherson if (!is_paging(vcpu)) 50351f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5036fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 50371f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5038fa4b5588SSean Christopherson else if (is_pae(vcpu)) 50391f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5040fa4b5588SSean Christopherson else 50411f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5042fa4b5588SSean Christopherson 5043533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5044c50d8ae3SPaolo Bonzini } 5045c50d8ae3SPaolo Bonzini 5046c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5047c50d8ae3SPaolo Bonzini { 504839e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 504939e7e2bfSPaolo Bonzini 5050c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 505139e7e2bfSPaolo Bonzini init_kvm_nested_mmu(vcpu, ®s); 5052c50d8ae3SPaolo Bonzini else if (tdp_enabled) 505339e7e2bfSPaolo Bonzini init_kvm_tdp_mmu(vcpu, ®s); 5054c50d8ae3SPaolo Bonzini else 505539e7e2bfSPaolo Bonzini init_kvm_softmmu(vcpu, ®s); 5056c50d8ae3SPaolo Bonzini } 5057c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5058c50d8ae3SPaolo Bonzini 505949c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 506049c6f875SSean Christopherson { 506149c6f875SSean Christopherson /* 506249c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 506349c6f875SSean Christopherson * information is factored into reserved bit calculations. 5064feb627e8SVitaly Kuznetsov * 5065feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5066feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5067feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5068feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5069feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5070feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5071feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 507249c6f875SSean Christopherson */ 50737a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 50747a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 50757a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5076e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5077e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5078e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 507949c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 508063f5a190SSean Christopherson 508163f5a190SSean Christopherson /* 5082feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5083feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 508463f5a190SSean Christopherson */ 5085feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 508649c6f875SSean Christopherson } 508749c6f875SSean Christopherson 5088c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5089c50d8ae3SPaolo Bonzini { 5090c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5091c9060662SSean Christopherson kvm_init_mmu(vcpu); 5092c50d8ae3SPaolo Bonzini } 5093c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5094c50d8ae3SPaolo Bonzini 5095c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5096c50d8ae3SPaolo Bonzini { 5097c50d8ae3SPaolo Bonzini int r; 5098c50d8ae3SPaolo Bonzini 5099378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->direct_map); 5100c50d8ae3SPaolo Bonzini if (r) 5101c50d8ae3SPaolo Bonzini goto out; 5102748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5103c50d8ae3SPaolo Bonzini if (r) 5104c50d8ae3SPaolo Bonzini goto out; 51054a38162eSPaolo Bonzini if (vcpu->arch.mmu->direct_map) 51066e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 51076e6ec584SSean Christopherson else 51086e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5109c50d8ae3SPaolo Bonzini if (r) 5110c50d8ae3SPaolo Bonzini goto out; 5111a91f387bSSean Christopherson 5112a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5113a91f387bSSean Christopherson 5114727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5115db01416bSSean Christopherson 5116db01416bSSean Christopherson /* 5117db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5118db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5119db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5120db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5121db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5122db01416bSSean Christopherson */ 5123e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5124c50d8ae3SPaolo Bonzini out: 5125c50d8ae3SPaolo Bonzini return r; 5126c50d8ae3SPaolo Bonzini } 5127c50d8ae3SPaolo Bonzini 5128c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5129c50d8ae3SPaolo Bonzini { 51300c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 51310c1c92f1SPaolo Bonzini 51320c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5133b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 51340c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5135b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 51366d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5137c50d8ae3SPaolo Bonzini } 5138c50d8ae3SPaolo Bonzini 5139527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5140527d5cd7SSean Christopherson { 5141527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5142527d5cd7SSean Christopherson 5143527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5144527d5cd7SSean Christopherson return false; 5145527d5cd7SSean Christopherson 5146527d5cd7SSean Christopherson /* 5147527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5148527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5149527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5150527d5cd7SSean Christopherson * such false positives are relatively rare: 5151527d5cd7SSean Christopherson * 5152527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5153527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5154527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5155527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5156527d5cd7SSean Christopherson */ 5157527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5158527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5159527d5cd7SSean Christopherson } 5160527d5cd7SSean Christopherson 5161527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5162527d5cd7SSean Christopherson { 5163527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5164527d5cd7SSean Christopherson int i; 5165527d5cd7SSean Christopherson 5166527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5167527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5168527d5cd7SSean Christopherson 5169527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5170527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5171527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5172527d5cd7SSean Christopherson } 5173527d5cd7SSean Christopherson 5174527d5cd7SSean Christopherson if (roots_to_free) 5175527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5176527d5cd7SSean Christopherson } 5177527d5cd7SSean Christopherson 5178527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5179527d5cd7SSean Christopherson { 5180527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5181527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5182527d5cd7SSean Christopherson } 5183527d5cd7SSean Christopherson 5184c50d8ae3SPaolo Bonzini static bool need_remote_flush(u64 old, u64 new) 5185c50d8ae3SPaolo Bonzini { 5186c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old)) 5187c50d8ae3SPaolo Bonzini return false; 5188c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(new)) 5189c50d8ae3SPaolo Bonzini return true; 5190c50d8ae3SPaolo Bonzini if ((old ^ new) & PT64_BASE_ADDR_MASK) 5191c50d8ae3SPaolo Bonzini return true; 5192c50d8ae3SPaolo Bonzini old ^= shadow_nx_mask; 5193c50d8ae3SPaolo Bonzini new ^= shadow_nx_mask; 5194c50d8ae3SPaolo Bonzini return (old & ~new & PT64_PERM_MASK) != 0; 5195c50d8ae3SPaolo Bonzini } 5196c50d8ae3SPaolo Bonzini 5197c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5198c50d8ae3SPaolo Bonzini int *bytes) 5199c50d8ae3SPaolo Bonzini { 5200c50d8ae3SPaolo Bonzini u64 gentry = 0; 5201c50d8ae3SPaolo Bonzini int r; 5202c50d8ae3SPaolo Bonzini 5203c50d8ae3SPaolo Bonzini /* 5204c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5205c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5206c50d8ae3SPaolo Bonzini * when they have the same mode. 5207c50d8ae3SPaolo Bonzini */ 5208c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5209c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5210c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5211c50d8ae3SPaolo Bonzini *bytes = 8; 5212c50d8ae3SPaolo Bonzini } 5213c50d8ae3SPaolo Bonzini 5214c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5215c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5216c50d8ae3SPaolo Bonzini if (r) 5217c50d8ae3SPaolo Bonzini gentry = 0; 5218c50d8ae3SPaolo Bonzini } 5219c50d8ae3SPaolo Bonzini 5220c50d8ae3SPaolo Bonzini return gentry; 5221c50d8ae3SPaolo Bonzini } 5222c50d8ae3SPaolo Bonzini 5223c50d8ae3SPaolo Bonzini /* 5224c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5225c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5226c50d8ae3SPaolo Bonzini */ 5227c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5228c50d8ae3SPaolo Bonzini { 5229c50d8ae3SPaolo Bonzini /* 5230c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5231c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5232c50d8ae3SPaolo Bonzini */ 52333bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5234c50d8ae3SPaolo Bonzini return false; 5235c50d8ae3SPaolo Bonzini 5236c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5237c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5238c50d8ae3SPaolo Bonzini } 5239c50d8ae3SPaolo Bonzini 5240c50d8ae3SPaolo Bonzini /* 5241c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5242c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5243c50d8ae3SPaolo Bonzini */ 5244c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5245c50d8ae3SPaolo Bonzini int bytes) 5246c50d8ae3SPaolo Bonzini { 5247c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5248c50d8ae3SPaolo Bonzini 5249c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5250c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5251c50d8ae3SPaolo Bonzini 5252c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5253bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5254c50d8ae3SPaolo Bonzini 5255c50d8ae3SPaolo Bonzini /* 5256c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5257c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5258c50d8ae3SPaolo Bonzini */ 5259c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5260c50d8ae3SPaolo Bonzini return false; 5261c50d8ae3SPaolo Bonzini 5262c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5263c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5264c50d8ae3SPaolo Bonzini 5265c50d8ae3SPaolo Bonzini return misaligned; 5266c50d8ae3SPaolo Bonzini } 5267c50d8ae3SPaolo Bonzini 5268c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5269c50d8ae3SPaolo Bonzini { 5270c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5271c50d8ae3SPaolo Bonzini u64 *spte; 5272c50d8ae3SPaolo Bonzini int level; 5273c50d8ae3SPaolo Bonzini 5274c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5275c50d8ae3SPaolo Bonzini level = sp->role.level; 5276c50d8ae3SPaolo Bonzini *nspte = 1; 5277bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5278c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5279c50d8ae3SPaolo Bonzini /* 5280c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5281c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5282c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5283c50d8ae3SPaolo Bonzini */ 5284c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5285c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5286c50d8ae3SPaolo Bonzini page_offset <<= 1; 5287c50d8ae3SPaolo Bonzini *nspte = 2; 5288c50d8ae3SPaolo Bonzini } 5289c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5290c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5291c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5292c50d8ae3SPaolo Bonzini return NULL; 5293c50d8ae3SPaolo Bonzini } 5294c50d8ae3SPaolo Bonzini 5295c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5296c50d8ae3SPaolo Bonzini return spte; 5297c50d8ae3SPaolo Bonzini } 5298c50d8ae3SPaolo Bonzini 5299c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5300c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5301c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5302c50d8ae3SPaolo Bonzini { 5303c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5304c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5305c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5306c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5307c50d8ae3SPaolo Bonzini int npte; 530806152b2dSLai Jiangshan bool flush = false; 5309c50d8ae3SPaolo Bonzini 5310c50d8ae3SPaolo Bonzini /* 5311c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5312c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5313c50d8ae3SPaolo Bonzini */ 5314c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5315c50d8ae3SPaolo Bonzini return; 5316c50d8ae3SPaolo Bonzini 5317c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5318c50d8ae3SPaolo Bonzini 5319c50d8ae3SPaolo Bonzini /* 5320c50d8ae3SPaolo Bonzini * No need to care whether allocation memory is successful 5321d9f6e12fSIngo Molnar * or not since pte prefetch is skipped if it does not have 5322c50d8ae3SPaolo Bonzini * enough objects in the cache. 5323c50d8ae3SPaolo Bonzini */ 5324378f5cd6SSean Christopherson mmu_topup_memory_caches(vcpu, true); 5325c50d8ae3SPaolo Bonzini 5326531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5327c50d8ae3SPaolo Bonzini 5328c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5329c50d8ae3SPaolo Bonzini 5330c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5331c50d8ae3SPaolo Bonzini 5332c50d8ae3SPaolo Bonzini for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) { 5333c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5334c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5335c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5336c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5337c50d8ae3SPaolo Bonzini continue; 5338c50d8ae3SPaolo Bonzini } 5339c50d8ae3SPaolo Bonzini 5340c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5341c50d8ae3SPaolo Bonzini if (!spte) 5342c50d8ae3SPaolo Bonzini continue; 5343c50d8ae3SPaolo Bonzini 5344c50d8ae3SPaolo Bonzini while (npte--) { 5345c50d8ae3SPaolo Bonzini entry = *spte; 53462de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5347c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5348c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 5349c50d8ae3SPaolo Bonzini if (need_remote_flush(entry, *spte)) 535006152b2dSLai Jiangshan flush = true; 5351c50d8ae3SPaolo Bonzini ++spte; 5352c50d8ae3SPaolo Bonzini } 5353c50d8ae3SPaolo Bonzini } 535406152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5355531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5356c50d8ae3SPaolo Bonzini } 5357c50d8ae3SPaolo Bonzini 5358736c291cSSean Christopherson int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5359c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5360c50d8ae3SPaolo Bonzini { 536192daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5362c50d8ae3SPaolo Bonzini bool direct = vcpu->arch.mmu->direct_map; 5363c50d8ae3SPaolo Bonzini 5364b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5365ddce6208SSean Christopherson return RET_PF_RETRY; 5366ddce6208SSean Christopherson 5367c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5368c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5369736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5370c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5371c50d8ae3SPaolo Bonzini goto emulate; 5372c50d8ae3SPaolo Bonzini } 5373c50d8ae3SPaolo Bonzini 5374c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 53757a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 53767a02674dSSean Christopherson lower_32_bits(error_code), false); 537719025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 53787b367bc9SSean Christopherson return -EIO; 5379c50d8ae3SPaolo Bonzini } 5380c50d8ae3SPaolo Bonzini 5381c50d8ae3SPaolo Bonzini if (r < 0) 5382c50d8ae3SPaolo Bonzini return r; 538383a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 538483a2ba4cSSean Christopherson return 1; 5385c50d8ae3SPaolo Bonzini 5386c50d8ae3SPaolo Bonzini /* 5387c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5388c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5389c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5390c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5391c50d8ae3SPaolo Bonzini * and resume the guest. 5392c50d8ae3SPaolo Bonzini */ 5393c50d8ae3SPaolo Bonzini if (vcpu->arch.mmu->direct_map && 5394c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5395736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5396c50d8ae3SPaolo Bonzini return 1; 5397c50d8ae3SPaolo Bonzini } 5398c50d8ae3SPaolo Bonzini 5399c50d8ae3SPaolo Bonzini /* 5400c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5401c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5402c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5403c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5404c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5405c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5406c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5407c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5408c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5409c50d8ae3SPaolo Bonzini */ 5410736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 541192daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5412c50d8ae3SPaolo Bonzini emulate: 5413736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5414c50d8ae3SPaolo Bonzini insn_len); 5415c50d8ae3SPaolo Bonzini } 5416c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5417c50d8ae3SPaolo Bonzini 54185efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 54195efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5420c50d8ae3SPaolo Bonzini { 5421c50d8ae3SPaolo Bonzini int i; 5422c50d8ae3SPaolo Bonzini 54235efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 54245efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 54255efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5426c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5427c50d8ae3SPaolo Bonzini return; 5428c50d8ae3SPaolo Bonzini 5429e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 54305efac074SPaolo Bonzini } 54315efac074SPaolo Bonzini 54325efac074SPaolo Bonzini if (!mmu->invlpg) 54335efac074SPaolo Bonzini return; 54345efac074SPaolo Bonzini 54355efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5436b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5437c50d8ae3SPaolo Bonzini 5438c50d8ae3SPaolo Bonzini /* 5439c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5440c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5441c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5442c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5443c50d8ae3SPaolo Bonzini * just always sync it. 5444c50d8ae3SPaolo Bonzini * 5445c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5446c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5447c50d8ae3SPaolo Bonzini * for them. 5448c50d8ae3SPaolo Bonzini */ 5449c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5450c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5451c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 54525efac074SPaolo Bonzini } else { 54535efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 54545efac074SPaolo Bonzini } 54555efac074SPaolo Bonzini } 5456c50d8ae3SPaolo Bonzini 54575efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 54585efac074SPaolo Bonzini { 545905b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5460c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5461c50d8ae3SPaolo Bonzini } 5462c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5463c50d8ae3SPaolo Bonzini 54645efac074SPaolo Bonzini 5465c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5466c50d8ae3SPaolo Bonzini { 5467c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5468c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5469c50d8ae3SPaolo Bonzini uint i; 5470c50d8ae3SPaolo Bonzini 5471c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 5472b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5473c50d8ae3SPaolo Bonzini tlb_flush = true; 5474c50d8ae3SPaolo Bonzini } 5475c50d8ae3SPaolo Bonzini 5476c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5477c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5478be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 5479c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5480c50d8ae3SPaolo Bonzini tlb_flush = true; 5481c50d8ae3SPaolo Bonzini } 5482c50d8ae3SPaolo Bonzini } 5483c50d8ae3SPaolo Bonzini 5484c50d8ae3SPaolo Bonzini if (tlb_flush) 5485e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5486c50d8ae3SPaolo Bonzini 5487c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5488c50d8ae3SPaolo Bonzini 5489c50d8ae3SPaolo Bonzini /* 5490c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5491c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5492c50d8ae3SPaolo Bonzini * for them. 5493c50d8ae3SPaolo Bonzini */ 5494c50d8ae3SPaolo Bonzini } 5495c50d8ae3SPaolo Bonzini 5496746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5497746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5498c50d8ae3SPaolo Bonzini { 5499bde77235SSean Christopherson tdp_enabled = enable_tdp; 5500746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 550183013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5502703c335dSSean Christopherson 5503703c335dSSean Christopherson /* 55041d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5505703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5506703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5507703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5508703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5509703c335dSSean Christopherson */ 5510703c335dSSean Christopherson if (tdp_enabled) 55111d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5512703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 55131d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5514703c335dSSean Christopherson else 55151d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5516c50d8ae3SPaolo Bonzini } 5517bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5518c50d8ae3SPaolo Bonzini 5519c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5520269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5521269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5522269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5523c50d8ae3SPaolo Bonzini 5524c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5525c50d8ae3SPaolo Bonzini static __always_inline bool 5526269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5527c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 55281a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 55291a61b7dbSSean Christopherson bool flush) 5530c50d8ae3SPaolo Bonzini { 5531c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5532c50d8ae3SPaolo Bonzini 5533c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5534c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5535c50d8ae3SPaolo Bonzini if (iterator.rmap) 55360a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5537c50d8ae3SPaolo Bonzini 5538531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5539302695a5SSean Christopherson if (flush && flush_on_yield) { 5540c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5541c50d8ae3SPaolo Bonzini start_gfn, 5542c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5543c50d8ae3SPaolo Bonzini flush = false; 5544c50d8ae3SPaolo Bonzini } 5545531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5546c50d8ae3SPaolo Bonzini } 5547c50d8ae3SPaolo Bonzini } 5548c50d8ae3SPaolo Bonzini 5549c50d8ae3SPaolo Bonzini return flush; 5550c50d8ae3SPaolo Bonzini } 5551c50d8ae3SPaolo Bonzini 5552c50d8ae3SPaolo Bonzini static __always_inline bool 5553269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5554c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5555302695a5SSean Christopherson bool flush_on_yield) 5556c50d8ae3SPaolo Bonzini { 5557c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5558c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5559c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 55601a61b7dbSSean Christopherson flush_on_yield, false); 5561c50d8ae3SPaolo Bonzini } 5562c50d8ae3SPaolo Bonzini 5563c50d8ae3SPaolo Bonzini static __always_inline bool 5564610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5565302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5566c50d8ae3SPaolo Bonzini { 55673bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5568302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5569c50d8ae3SPaolo Bonzini } 5570c50d8ae3SPaolo Bonzini 5571c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5572c50d8ae3SPaolo Bonzini { 55734a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 55744a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5575c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 557603ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5577cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5578c50d8ae3SPaolo Bonzini } 5579c50d8ae3SPaolo Bonzini 558004d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5581c50d8ae3SPaolo Bonzini { 5582c50d8ae3SPaolo Bonzini struct page *page; 5583c50d8ae3SPaolo Bonzini int i; 5584c50d8ae3SPaolo Bonzini 5585b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5586b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 558704d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 558804d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 558904d28e37SSean Christopherson 559027f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 559127f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 559227f4fca2SLai Jiangshan return 0; 559327f4fca2SLai Jiangshan 5594c50d8ae3SPaolo Bonzini /* 5595c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5596c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5597c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5598c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 559904d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 560004d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 560104d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 560204d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 560384432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5604c50d8ae3SPaolo Bonzini */ 5605d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5606c50d8ae3SPaolo Bonzini return 0; 5607c50d8ae3SPaolo Bonzini 5608c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5609c50d8ae3SPaolo Bonzini if (!page) 5610c50d8ae3SPaolo Bonzini return -ENOMEM; 5611c50d8ae3SPaolo Bonzini 5612c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 56134a98623dSSean Christopherson 56144a98623dSSean Christopherson /* 56154a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 56164a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 56174a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 56184a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 56194a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 56204a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 56214a98623dSSean Christopherson */ 56224a98623dSSean Christopherson if (!tdp_enabled) 56234a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 56244a98623dSSean Christopherson else 56254a98623dSSean Christopherson WARN_ON_ONCE(shadow_me_mask); 56264a98623dSSean Christopherson 5627c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5628c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5629c50d8ae3SPaolo Bonzini 5630c50d8ae3SPaolo Bonzini return 0; 5631c50d8ae3SPaolo Bonzini } 5632c50d8ae3SPaolo Bonzini 5633c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5634c50d8ae3SPaolo Bonzini { 5635c50d8ae3SPaolo Bonzini int ret; 5636c50d8ae3SPaolo Bonzini 56375962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 56385f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 56395f6078f9SSean Christopherson 56405962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 56415f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 56425962bfb7SSean Christopherson 564396880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 564496880883SSean Christopherson 5645c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5646c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5647c50d8ae3SPaolo Bonzini 564804d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5649c50d8ae3SPaolo Bonzini if (ret) 5650c50d8ae3SPaolo Bonzini return ret; 5651c50d8ae3SPaolo Bonzini 565204d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5653c50d8ae3SPaolo Bonzini if (ret) 5654c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5655c50d8ae3SPaolo Bonzini 5656c50d8ae3SPaolo Bonzini return ret; 5657c50d8ae3SPaolo Bonzini fail_allocate_root: 5658c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5659c50d8ae3SPaolo Bonzini return ret; 5660c50d8ae3SPaolo Bonzini } 5661c50d8ae3SPaolo Bonzini 5662c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5663c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5664c50d8ae3SPaolo Bonzini { 5665c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5666c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5667c50d8ae3SPaolo Bonzini 5668c50d8ae3SPaolo Bonzini restart: 5669c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5670c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5671c50d8ae3SPaolo Bonzini /* 5672c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5673c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5674c50d8ae3SPaolo Bonzini */ 5675c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5676c50d8ae3SPaolo Bonzini break; 5677c50d8ae3SPaolo Bonzini 5678c50d8ae3SPaolo Bonzini /* 5679f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5680f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5681f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5682c50d8ae3SPaolo Bonzini */ 5683f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5684c50d8ae3SPaolo Bonzini continue; 5685c50d8ae3SPaolo Bonzini 5686c50d8ae3SPaolo Bonzini /* 5687c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5688c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5689c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5690c50d8ae3SPaolo Bonzini * be in active use by the guest. 5691c50d8ae3SPaolo Bonzini */ 5692c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5693531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5694c50d8ae3SPaolo Bonzini batch = 0; 5695c50d8ae3SPaolo Bonzini goto restart; 5696c50d8ae3SPaolo Bonzini } 5697c50d8ae3SPaolo Bonzini 5698c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, 5699c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages, &nr_zapped)) { 5700c50d8ae3SPaolo Bonzini batch += nr_zapped; 5701c50d8ae3SPaolo Bonzini goto restart; 5702c50d8ae3SPaolo Bonzini } 5703c50d8ae3SPaolo Bonzini } 5704c50d8ae3SPaolo Bonzini 5705c50d8ae3SPaolo Bonzini /* 57067ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 57077ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 57087ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 57097ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 57107ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 57117ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 57127ae5840eSSean Christopherson * running with an obsolete MMU. 5713c50d8ae3SPaolo Bonzini */ 5714c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5715c50d8ae3SPaolo Bonzini } 5716c50d8ae3SPaolo Bonzini 5717c50d8ae3SPaolo Bonzini /* 5718c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5719c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5720c50d8ae3SPaolo Bonzini * 5721c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5722c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5723c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5724c50d8ae3SPaolo Bonzini * after calling the function. 5725c50d8ae3SPaolo Bonzini */ 5726c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5727c50d8ae3SPaolo Bonzini { 5728c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5729c50d8ae3SPaolo Bonzini 5730531810caSBen Gardon write_lock(&kvm->mmu_lock); 5731c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5732c50d8ae3SPaolo Bonzini 5733c50d8ae3SPaolo Bonzini /* 5734c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5735c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5736c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5737c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5738c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5739c50d8ae3SPaolo Bonzini */ 5740c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5741c50d8ae3SPaolo Bonzini 57422f6f66ccSSean Christopherson /* 57432f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 57442f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 57452f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 57462f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5747b7cccd39SBen Gardon */ 5748b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5749b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5750b7cccd39SBen Gardon 5751c50d8ae3SPaolo Bonzini /* 5752c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5753c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5754c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5755c50d8ae3SPaolo Bonzini * 5756c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5757c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5758c50d8ae3SPaolo Bonzini */ 5759527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5760c50d8ae3SPaolo Bonzini 5761c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5762faaf05b0SBen Gardon 5763531810caSBen Gardon write_unlock(&kvm->mmu_lock); 57644c6654bdSBen Gardon 5765f28e9c7fSSean Christopherson /* 5766f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5767f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5768f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5769f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5770f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5771f28e9c7fSSean Christopherson * lead to use-after-free. 5772f28e9c7fSSean Christopherson */ 577322b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 57744c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5775c50d8ae3SPaolo Bonzini } 5776c50d8ae3SPaolo Bonzini 5777c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5778c50d8ae3SPaolo Bonzini { 5779c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5780c50d8ae3SPaolo Bonzini } 5781c50d8ae3SPaolo Bonzini 5782c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5783c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5784c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5785c50d8ae3SPaolo Bonzini { 5786c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5787c50d8ae3SPaolo Bonzini } 5788c50d8ae3SPaolo Bonzini 5789a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5790c50d8ae3SPaolo Bonzini { 5791c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5792a1a39128SPaolo Bonzini int r; 5793c50d8ae3SPaolo Bonzini 5794a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5795a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5796a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5797ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5798ce25681dSSean Christopherson 5799a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5800a1a39128SPaolo Bonzini if (r < 0) 5801a1a39128SPaolo Bonzini return r; 5802fe5db27dSBen Gardon 5803c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5804c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5805c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5806a1a39128SPaolo Bonzini return 0; 5807c50d8ae3SPaolo Bonzini } 5808c50d8ae3SPaolo Bonzini 5809c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 5810c50d8ae3SPaolo Bonzini { 5811c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5812c50d8ae3SPaolo Bonzini 5813c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 5814fe5db27dSBen Gardon 5815fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 5816c50d8ae3SPaolo Bonzini } 5817c50d8ae3SPaolo Bonzini 581821fa3246SSean Christopherson static bool __kvm_zap_rmaps(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 581921fa3246SSean Christopherson { 582021fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 582121fa3246SSean Christopherson struct kvm_memslots *slots; 5822f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 582321fa3246SSean Christopherson bool flush = false; 582421fa3246SSean Christopherson gfn_t start, end; 5825f4209439SMaciej S. Szmigiero int i; 582621fa3246SSean Christopherson 582721fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 582821fa3246SSean Christopherson return flush; 582921fa3246SSean Christopherson 583021fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 583121fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 5832f4209439SMaciej S. Szmigiero 5833f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 5834f4209439SMaciej S. Szmigiero memslot = iter.slot; 583521fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 583621fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 5837f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 583821fa3246SSean Christopherson continue; 583921fa3246SSean Christopherson 584021fa3246SSean Christopherson flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, 58416ff94f27SDavid Matlack 584221fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 584321fa3246SSean Christopherson start, end - 1, true, flush); 584421fa3246SSean Christopherson } 584521fa3246SSean Christopherson } 584621fa3246SSean Christopherson 584721fa3246SSean Christopherson return flush; 584821fa3246SSean Christopherson } 584921fa3246SSean Christopherson 585088f58535SMaxim Levitsky /* 585188f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 585288f58535SMaxim Levitsky * (not including it) 585388f58535SMaxim Levitsky */ 5854c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 5855c50d8ae3SPaolo Bonzini { 585621fa3246SSean Christopherson bool flush; 5857c50d8ae3SPaolo Bonzini int i; 5858c50d8ae3SPaolo Bonzini 5859f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 5860f4209439SMaciej S. Szmigiero return; 5861f4209439SMaciej S. Szmigiero 5862531810caSBen Gardon write_lock(&kvm->mmu_lock); 58635a324c24SSean Christopherson 5864edb298c6SMaxim Levitsky kvm_inc_notifier_count(kvm, gfn_start, gfn_end); 5865edb298c6SMaxim Levitsky 586621fa3246SSean Christopherson flush = __kvm_zap_rmaps(kvm, gfn_start, gfn_end); 58676103bc07SBen Gardon 58686103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 58696103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 5870f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 5871f47e5bbbSSean Christopherson gfn_end, true, flush); 58726103bc07SBen Gardon } 58735a324c24SSean Christopherson 58745a324c24SSean Christopherson if (flush) 5875bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 5876bc3b3c10SSean Christopherson gfn_end - gfn_start); 58775a324c24SSean Christopherson 5878edb298c6SMaxim Levitsky kvm_dec_notifier_count(kvm, gfn_start, gfn_end); 5879edb298c6SMaxim Levitsky 58805a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 5881c50d8ae3SPaolo Bonzini } 5882c50d8ae3SPaolo Bonzini 5883c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 58840a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 5885269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5886c50d8ae3SPaolo Bonzini { 58871346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 5888c50d8ae3SPaolo Bonzini } 5889c50d8ae3SPaolo Bonzini 5890c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 5891269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 58923c9bd400SJay Zhou int start_level) 5893c50d8ae3SPaolo Bonzini { 5894e2209710SBen Gardon bool flush = false; 5895c50d8ae3SPaolo Bonzini 5896e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 5897531810caSBen Gardon write_lock(&kvm->mmu_lock); 58983c9bd400SJay Zhou flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, 5899e2209710SBen Gardon start_level, KVM_MAX_HUGEPAGE_LEVEL, 5900e2209710SBen Gardon false); 5901531810caSBen Gardon write_unlock(&kvm->mmu_lock); 5902e2209710SBen Gardon } 5903c50d8ae3SPaolo Bonzini 590424ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 590524ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 590624ae4cfaSBen Gardon flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 590724ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 590824ae4cfaSBen Gardon } 590924ae4cfaSBen Gardon 5910c50d8ae3SPaolo Bonzini /* 59116ff94f27SDavid Matlack * Flush TLBs if any SPTEs had to be write-protected to ensure that 59126ff94f27SDavid Matlack * guest writes are reflected in the dirty bitmap before the memslot 59136ff94f27SDavid Matlack * update completes, i.e. before enabling dirty logging is visible to 59146ff94f27SDavid Matlack * userspace. 59156ff94f27SDavid Matlack * 59166ff94f27SDavid Matlack * Perform the TLB flush outside the mmu_lock to reduce the amount of 59176ff94f27SDavid Matlack * time the lock is held. However, this does mean that another CPU can 59186ff94f27SDavid Matlack * now grab mmu_lock and encounter a write-protected SPTE while CPUs 59196ff94f27SDavid Matlack * still have a writable mapping for the associated GFN in their TLB. 59206ff94f27SDavid Matlack * 59216ff94f27SDavid Matlack * This is safe but requires KVM to be careful when making decisions 59226ff94f27SDavid Matlack * based on the write-protection status of an SPTE. Specifically, KVM 59236ff94f27SDavid Matlack * also write-protects SPTEs to monitor changes to guest page tables 59246ff94f27SDavid Matlack * during shadow paging, and must guarantee no CPUs can write to those 59256ff94f27SDavid Matlack * page before the lock is dropped. As mentioned in the previous 59266ff94f27SDavid Matlack * paragraph, a write-protected SPTE is no guarantee that CPU cannot 59276ff94f27SDavid Matlack * perform writes. So to determine if a TLB flush is truly required, KVM 59286ff94f27SDavid Matlack * will clear a separate software-only bit (MMU-writable) and skip the 59296ff94f27SDavid Matlack * flush if-and-only-if this bit was already clear. 59306ff94f27SDavid Matlack * 593102844ac1SDavid Matlack * See is_writable_pte() for more details. 5932c50d8ae3SPaolo Bonzini */ 5933c50d8ae3SPaolo Bonzini if (flush) 59347f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 5935c50d8ae3SPaolo Bonzini } 5936c50d8ae3SPaolo Bonzini 5937cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 5938cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 5939cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 5940cb00a70bSDavid Matlack u64 start, u64 end, 5941cb00a70bSDavid Matlack int target_level) 5942cb00a70bSDavid Matlack { 5943cb00a70bSDavid Matlack if (is_tdp_mmu_enabled(kvm)) 5944cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, 5945cb00a70bSDavid Matlack target_level, false); 5946cb00a70bSDavid Matlack 5947cb00a70bSDavid Matlack /* 5948cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 5949cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 5950cb00a70bSDavid Matlack */ 5951cb00a70bSDavid Matlack } 5952cb00a70bSDavid Matlack 5953a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 5954a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 5955a3fe5dbdSDavid Matlack int target_level) 5956a3fe5dbdSDavid Matlack { 5957a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 5958a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 5959a3fe5dbdSDavid Matlack 5960a3fe5dbdSDavid Matlack if (is_tdp_mmu_enabled(kvm)) { 5961a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 5962cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 5963a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 5964a3fe5dbdSDavid Matlack } 5965a3fe5dbdSDavid Matlack 5966a3fe5dbdSDavid Matlack /* 5967a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 5968a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 5969a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 5970a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 5971a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 5972a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 5973a3fe5dbdSDavid Matlack * SPTEs. 5974a3fe5dbdSDavid Matlack */ 5975a3fe5dbdSDavid Matlack } 5976a3fe5dbdSDavid Matlack 5977c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 59780a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 5979269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5980c50d8ae3SPaolo Bonzini { 5981c50d8ae3SPaolo Bonzini u64 *sptep; 5982c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 5983c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 5984c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 5985c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5986c50d8ae3SPaolo Bonzini 5987c50d8ae3SPaolo Bonzini restart: 5988c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 598957354682SSean Christopherson sp = sptep_to_sp(sptep); 5990c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(*sptep); 5991c50d8ae3SPaolo Bonzini 5992c50d8ae3SPaolo Bonzini /* 5993c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 5994c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 5995c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 5996c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 5997c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 5998c50d8ae3SPaolo Bonzini */ 5999c50d8ae3SPaolo Bonzini if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && 60009eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 60019eba50f8SSean Christopherson pfn, PG_LEVEL_NUM)) { 600271f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 6003c50d8ae3SPaolo Bonzini 6004c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6005c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6006c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6007c50d8ae3SPaolo Bonzini else 6008c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6009c50d8ae3SPaolo Bonzini 6010c50d8ae3SPaolo Bonzini goto restart; 6011c50d8ae3SPaolo Bonzini } 6012c50d8ae3SPaolo Bonzini } 6013c50d8ae3SPaolo Bonzini 6014c50d8ae3SPaolo Bonzini return need_tlb_flush; 6015c50d8ae3SPaolo Bonzini } 6016c50d8ae3SPaolo Bonzini 6017c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6018269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6019c50d8ae3SPaolo Bonzini { 6020e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6021531810caSBen Gardon write_lock(&kvm->mmu_lock); 6022610265eaSDavid Matlack /* 6023610265eaSDavid Matlack * Zap only 4k SPTEs since the legacy MMU only supports dirty 6024610265eaSDavid Matlack * logging at a 4k granularity and never creates collapsible 6025610265eaSDavid Matlack * 2m SPTEs during dirty logging. 6026610265eaSDavid Matlack */ 60274b85c921SSean Christopherson if (slot_handle_level_4k(kvm, slot, kvm_mmu_zap_collapsible_spte, true)) 6028302695a5SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 6029531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6030e2209710SBen Gardon } 60312db6f772SBen Gardon 60322db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60332db6f772SBen Gardon read_lock(&kvm->mmu_lock); 60344b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 60352db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 60362db6f772SBen Gardon } 6037c50d8ae3SPaolo Bonzini } 6038c50d8ae3SPaolo Bonzini 6039b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 60406c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6041b3594ffbSSean Christopherson { 6042b3594ffbSSean Christopherson /* 60437f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6044302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 60457f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 60467f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 60477f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6048b3594ffbSSean Christopherson */ 6049b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6050cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6051cec37648SSean Christopherson memslot->npages); 6052b3594ffbSSean Christopherson } 6053b3594ffbSSean Christopherson 6054c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6055269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6056c50d8ae3SPaolo Bonzini { 6057e2209710SBen Gardon bool flush = false; 6058c50d8ae3SPaolo Bonzini 6059e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6060531810caSBen Gardon write_lock(&kvm->mmu_lock); 6061610265eaSDavid Matlack /* 6062610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6063610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6064610265eaSDavid Matlack */ 6065610265eaSDavid Matlack flush = slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6066531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6067e2209710SBen Gardon } 6068c50d8ae3SPaolo Bonzini 606924ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 607024ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 607124ae4cfaSBen Gardon flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 607224ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 607324ae4cfaSBen Gardon } 607424ae4cfaSBen Gardon 6075c50d8ae3SPaolo Bonzini /* 6076c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6077c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6078c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6079c50d8ae3SPaolo Bonzini * dirty_bitmap. 6080c50d8ae3SPaolo Bonzini */ 6081c50d8ae3SPaolo Bonzini if (flush) 60827f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6083c50d8ae3SPaolo Bonzini } 6084c50d8ae3SPaolo Bonzini 6085c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6086c50d8ae3SPaolo Bonzini { 6087c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6088c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6089c50d8ae3SPaolo Bonzini int ign; 6090c50d8ae3SPaolo Bonzini 6091531810caSBen Gardon write_lock(&kvm->mmu_lock); 6092c50d8ae3SPaolo Bonzini restart: 6093c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6094f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6095c50d8ae3SPaolo Bonzini continue; 6096c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6097c50d8ae3SPaolo Bonzini goto restart; 6098531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6099c50d8ae3SPaolo Bonzini goto restart; 6100c50d8ae3SPaolo Bonzini } 6101c50d8ae3SPaolo Bonzini 6102c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6103faaf05b0SBen Gardon 6104897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6105faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6106faaf05b0SBen Gardon 6107531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6108c50d8ae3SPaolo Bonzini } 6109c50d8ae3SPaolo Bonzini 6110c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6111c50d8ae3SPaolo Bonzini { 6112c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6113c50d8ae3SPaolo Bonzini 6114c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6115c50d8ae3SPaolo Bonzini 6116c50d8ae3SPaolo Bonzini /* 6117c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6118c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6119c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6120c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6121c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6122c50d8ae3SPaolo Bonzini */ 6123c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6124c50d8ae3SPaolo Bonzini 6125c50d8ae3SPaolo Bonzini /* 6126c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6127c50d8ae3SPaolo Bonzini * zap all shadow pages. 6128c50d8ae3SPaolo Bonzini */ 6129c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6130c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6131c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6132c50d8ae3SPaolo Bonzini } 6133c50d8ae3SPaolo Bonzini } 6134c50d8ae3SPaolo Bonzini 6135c50d8ae3SPaolo Bonzini static unsigned long 6136c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6137c50d8ae3SPaolo Bonzini { 6138c50d8ae3SPaolo Bonzini struct kvm *kvm; 6139c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6140c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6141c50d8ae3SPaolo Bonzini 6142c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6143c50d8ae3SPaolo Bonzini 6144c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6145c50d8ae3SPaolo Bonzini int idx; 6146c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6147c50d8ae3SPaolo Bonzini 6148c50d8ae3SPaolo Bonzini /* 6149c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6150c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6151c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6152c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6153c50d8ae3SPaolo Bonzini */ 6154c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6155c50d8ae3SPaolo Bonzini break; 6156c50d8ae3SPaolo Bonzini /* 6157c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6158c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6159c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6160c50d8ae3SPaolo Bonzini * anyway. 6161c50d8ae3SPaolo Bonzini */ 6162c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6163c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6164c50d8ae3SPaolo Bonzini continue; 6165c50d8ae3SPaolo Bonzini 6166c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6167531810caSBen Gardon write_lock(&kvm->mmu_lock); 6168c50d8ae3SPaolo Bonzini 6169c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6170c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6171c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6172c50d8ae3SPaolo Bonzini goto unlock; 6173c50d8ae3SPaolo Bonzini } 6174c50d8ae3SPaolo Bonzini 6175ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6176c50d8ae3SPaolo Bonzini 6177c50d8ae3SPaolo Bonzini unlock: 6178531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6179c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6180c50d8ae3SPaolo Bonzini 6181c50d8ae3SPaolo Bonzini /* 6182c50d8ae3SPaolo Bonzini * unfair on small ones 6183c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6184c50d8ae3SPaolo Bonzini * sadness comes quickly 6185c50d8ae3SPaolo Bonzini */ 6186c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6187c50d8ae3SPaolo Bonzini break; 6188c50d8ae3SPaolo Bonzini } 6189c50d8ae3SPaolo Bonzini 6190c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6191c50d8ae3SPaolo Bonzini return freed; 6192c50d8ae3SPaolo Bonzini } 6193c50d8ae3SPaolo Bonzini 6194c50d8ae3SPaolo Bonzini static unsigned long 6195c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6196c50d8ae3SPaolo Bonzini { 6197c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6198c50d8ae3SPaolo Bonzini } 6199c50d8ae3SPaolo Bonzini 6200c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6201c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6202c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6203c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6204c50d8ae3SPaolo Bonzini }; 6205c50d8ae3SPaolo Bonzini 6206c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6207c50d8ae3SPaolo Bonzini { 6208c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6209c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6210c50d8ae3SPaolo Bonzini } 6211c50d8ae3SPaolo Bonzini 6212c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6213c50d8ae3SPaolo Bonzini { 6214c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6215c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6216c50d8ae3SPaolo Bonzini } 6217c50d8ae3SPaolo Bonzini 6218c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6219c50d8ae3SPaolo Bonzini { 6220c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6221c50d8ae3SPaolo Bonzini } 6222c50d8ae3SPaolo Bonzini 6223c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6224c50d8ae3SPaolo Bonzini { 6225c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6226c50d8ae3SPaolo Bonzini bool new_val; 6227c50d8ae3SPaolo Bonzini 6228c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6229c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6230c50d8ae3SPaolo Bonzini new_val = 0; 6231c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6232c50d8ae3SPaolo Bonzini new_val = 1; 6233c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6234c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6235c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6236c50d8ae3SPaolo Bonzini return -EINVAL; 6237c50d8ae3SPaolo Bonzini 6238c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6239c50d8ae3SPaolo Bonzini 6240c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6241c50d8ae3SPaolo Bonzini struct kvm *kvm; 6242c50d8ae3SPaolo Bonzini 6243c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6244c50d8ae3SPaolo Bonzini 6245c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6246c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6247c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6248c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6249c50d8ae3SPaolo Bonzini 6250c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6251c50d8ae3SPaolo Bonzini } 6252c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6253c50d8ae3SPaolo Bonzini } 6254c50d8ae3SPaolo Bonzini 6255c50d8ae3SPaolo Bonzini return 0; 6256c50d8ae3SPaolo Bonzini } 6257c50d8ae3SPaolo Bonzini 62581d0e8480SSean Christopherson /* 62591d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 62601d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 62611d0e8480SSean Christopherson */ 62621d0e8480SSean Christopherson void kvm_mmu_x86_module_init(void) 6263c50d8ae3SPaolo Bonzini { 6264c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6265c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 62661d0e8480SSean Christopherson } 62671d0e8480SSean Christopherson 62681d0e8480SSean Christopherson /* 62691d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 62701d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 62711d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 62721d0e8480SSean Christopherson */ 62731d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 62741d0e8480SSean Christopherson { 62751d0e8480SSean Christopherson int ret = -ENOMEM; 6276c50d8ae3SPaolo Bonzini 6277c50d8ae3SPaolo Bonzini /* 6278c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6279c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6280c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6281c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6282c50d8ae3SPaolo Bonzini */ 6283c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6284c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 62857a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6286c50d8ae3SPaolo Bonzini 6287c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6288c50d8ae3SPaolo Bonzini 6289c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6290c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6291c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6292c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6293c50d8ae3SPaolo Bonzini goto out; 6294c50d8ae3SPaolo Bonzini 6295c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6296c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6297c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6298c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6299c50d8ae3SPaolo Bonzini goto out; 6300c50d8ae3SPaolo Bonzini 6301c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6302c50d8ae3SPaolo Bonzini goto out; 6303c50d8ae3SPaolo Bonzini 6304c50d8ae3SPaolo Bonzini ret = register_shrinker(&mmu_shrinker); 6305c50d8ae3SPaolo Bonzini if (ret) 6306c50d8ae3SPaolo Bonzini goto out; 6307c50d8ae3SPaolo Bonzini 6308c50d8ae3SPaolo Bonzini return 0; 6309c50d8ae3SPaolo Bonzini 6310c50d8ae3SPaolo Bonzini out: 6311c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6312c50d8ae3SPaolo Bonzini return ret; 6313c50d8ae3SPaolo Bonzini } 6314c50d8ae3SPaolo Bonzini 6315c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6316c50d8ae3SPaolo Bonzini { 6317c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6318c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6319c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6320c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6321c50d8ae3SPaolo Bonzini } 6322c50d8ae3SPaolo Bonzini 63231d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6324c50d8ae3SPaolo Bonzini { 6325c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6326c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6327c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6328c50d8ae3SPaolo Bonzini } 6329c50d8ae3SPaolo Bonzini 6330f47491d7SSean Christopherson /* 6331f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6332f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6333f47491d7SSean Christopherson */ 6334f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6335f47491d7SSean Christopherson { 6336f47491d7SSean Christopherson /* 6337f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6338f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6339f47491d7SSean Christopherson */ 6340f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6341f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6342f47491d7SSean Christopherson 6343f47491d7SSean Christopherson if (!enabled || !ratio) 6344f47491d7SSean Christopherson return false; 6345f47491d7SSean Christopherson 6346f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6347f47491d7SSean Christopherson if (!*period) { 6348f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6349f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6350f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6351f47491d7SSean Christopherson } 6352f47491d7SSean Christopherson return true; 6353f47491d7SSean Christopherson } 6354f47491d7SSean Christopherson 63554dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6356c50d8ae3SPaolo Bonzini { 63574dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 63584dfe4f40SJunaid Shahid uint old_period, new_period; 6359c50d8ae3SPaolo Bonzini int err; 6360c50d8ae3SPaolo Bonzini 6361f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 63624dfe4f40SJunaid Shahid 6363c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6364c50d8ae3SPaolo Bonzini if (err) 6365c50d8ae3SPaolo Bonzini return err; 6366c50d8ae3SPaolo Bonzini 6367f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 63684dfe4f40SJunaid Shahid 6369f47491d7SSean Christopherson if (is_recovery_enabled && 63704dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6371c50d8ae3SPaolo Bonzini struct kvm *kvm; 6372c50d8ae3SPaolo Bonzini 6373c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6374c50d8ae3SPaolo Bonzini 6375c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6376c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6377c50d8ae3SPaolo Bonzini 6378c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6379c50d8ae3SPaolo Bonzini } 6380c50d8ae3SPaolo Bonzini 6381c50d8ae3SPaolo Bonzini return err; 6382c50d8ae3SPaolo Bonzini } 6383c50d8ae3SPaolo Bonzini 6384c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6385c50d8ae3SPaolo Bonzini { 6386ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6387c50d8ae3SPaolo Bonzini int rcu_idx; 6388c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6389c50d8ae3SPaolo Bonzini unsigned int ratio; 6390c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6391048f4980SSean Christopherson bool flush = false; 6392c50d8ae3SPaolo Bonzini ulong to_zap; 6393c50d8ae3SPaolo Bonzini 6394c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6395531810caSBen Gardon write_lock(&kvm->mmu_lock); 6396c50d8ae3SPaolo Bonzini 6397bb95dfb9SSean Christopherson /* 6398bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6399bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6400bb95dfb9SSean Christopherson * callback. 6401bb95dfb9SSean Christopherson */ 6402bb95dfb9SSean Christopherson rcu_read_lock(); 6403bb95dfb9SSean Christopherson 6404c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6405ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 64067d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 64077d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 64087d919c7aSSean Christopherson break; 64097d919c7aSSean Christopherson 6410c50d8ae3SPaolo Bonzini /* 6411c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6412c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6413c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6414c50d8ae3SPaolo Bonzini */ 6415c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6416c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6417c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6418c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6419897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6420315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 64218d1a182eSBen Gardon } else { 6422c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6423c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 642429cf0f50SBen Gardon } 6425c50d8ae3SPaolo Bonzini 6426531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6427048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6428bb95dfb9SSean Christopherson rcu_read_unlock(); 6429bb95dfb9SSean Christopherson 6430531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6431048f4980SSean Christopherson flush = false; 6432bb95dfb9SSean Christopherson 6433bb95dfb9SSean Christopherson rcu_read_lock(); 6434c50d8ae3SPaolo Bonzini } 6435c50d8ae3SPaolo Bonzini } 6436048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6437c50d8ae3SPaolo Bonzini 6438bb95dfb9SSean Christopherson rcu_read_unlock(); 6439bb95dfb9SSean Christopherson 6440531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6441c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6442c50d8ae3SPaolo Bonzini } 6443c50d8ae3SPaolo Bonzini 6444c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6445c50d8ae3SPaolo Bonzini { 6446f47491d7SSean Christopherson bool enabled; 6447f47491d7SSean Christopherson uint period; 64484dfe4f40SJunaid Shahid 6449f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 64504dfe4f40SJunaid Shahid 6451f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6452c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6453c50d8ae3SPaolo Bonzini } 6454c50d8ae3SPaolo Bonzini 6455c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6456c50d8ae3SPaolo Bonzini { 6457c50d8ae3SPaolo Bonzini u64 start_time; 6458c50d8ae3SPaolo Bonzini long remaining_time; 6459c50d8ae3SPaolo Bonzini 6460c50d8ae3SPaolo Bonzini while (true) { 6461c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6462c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6463c50d8ae3SPaolo Bonzini 6464c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6465c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6466c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6467c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6468c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6469c50d8ae3SPaolo Bonzini } 6470c50d8ae3SPaolo Bonzini 6471c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6472c50d8ae3SPaolo Bonzini 6473c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6474c50d8ae3SPaolo Bonzini return 0; 6475c50d8ae3SPaolo Bonzini 6476c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6477c50d8ae3SPaolo Bonzini } 6478c50d8ae3SPaolo Bonzini } 6479c50d8ae3SPaolo Bonzini 6480c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6481c50d8ae3SPaolo Bonzini { 6482c50d8ae3SPaolo Bonzini int err; 6483c50d8ae3SPaolo Bonzini 6484c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6485c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6486c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6487c50d8ae3SPaolo Bonzini if (!err) 6488c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6489c50d8ae3SPaolo Bonzini 6490c50d8ae3SPaolo Bonzini return err; 6491c50d8ae3SPaolo Bonzini } 6492c50d8ae3SPaolo Bonzini 6493c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6494c50d8ae3SPaolo Bonzini { 6495c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6496c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6497c50d8ae3SPaolo Bonzini } 6498