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 196594e91a1SSean Christopherson * reading from the role_regs. Once the mmu_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) \ 2004ac21457SPaolo Bonzini static inline bool __maybe_unused ____is_##reg##_##name(struct kvm_mmu_role_regs *regs)\ 201594e91a1SSean Christopherson { \ 202594e91a1SSean Christopherson return !!(regs->reg & flag); \ 203594e91a1SSean Christopherson } 204594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 205594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 206594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 207594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 208594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 209594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 210594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 211594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 212594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 213594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 214594e91a1SSean Christopherson 21560667724SSean Christopherson /* 21660667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 21760667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 21860667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 21960667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 22060667724SSean Christopherson */ 22160667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2224ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 22360667724SSean Christopherson { \ 22460667724SSean Christopherson return !!(mmu->mmu_role. base_or_ext . reg##_##name); \ 22560667724SSean Christopherson } 22660667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr0, pg); 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, pae); 23060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 23160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 23260667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 23360667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 23460667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 23560667724SSean Christopherson 236594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 237594e91a1SSean Christopherson { 238594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 239594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 240594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 241594e91a1SSean Christopherson .efer = vcpu->arch.efer, 242594e91a1SSean Christopherson }; 243594e91a1SSean Christopherson 244594e91a1SSean Christopherson return regs; 245594e91a1SSean Christopherson } 246c50d8ae3SPaolo Bonzini 247f4bd6f73SSean Christopherson static int role_regs_to_root_level(struct kvm_mmu_role_regs *regs) 248f4bd6f73SSean Christopherson { 249f4bd6f73SSean Christopherson if (!____is_cr0_pg(regs)) 250f4bd6f73SSean Christopherson return 0; 251f4bd6f73SSean Christopherson else if (____is_efer_lma(regs)) 252f4bd6f73SSean Christopherson return ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL : 253f4bd6f73SSean Christopherson PT64_ROOT_4LEVEL; 254f4bd6f73SSean Christopherson else if (____is_cr4_pae(regs)) 255f4bd6f73SSean Christopherson return PT32E_ROOT_LEVEL; 256f4bd6f73SSean Christopherson else 257f4bd6f73SSean Christopherson return PT32_ROOT_LEVEL; 258f4bd6f73SSean Christopherson } 259c50d8ae3SPaolo Bonzini 260c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 261c50d8ae3SPaolo Bonzini { 262afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 263c50d8ae3SPaolo Bonzini } 264c50d8ae3SPaolo Bonzini 265c50d8ae3SPaolo Bonzini static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm, 266c50d8ae3SPaolo Bonzini struct kvm_tlb_range *range) 267c50d8ae3SPaolo Bonzini { 268c50d8ae3SPaolo Bonzini int ret = -ENOTSUPP; 269c50d8ae3SPaolo Bonzini 270afaf0b2fSSean Christopherson if (range && kvm_x86_ops.tlb_remote_flush_with_range) 271b3646477SJason Baron ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range); 272c50d8ae3SPaolo Bonzini 273c50d8ae3SPaolo Bonzini if (ret) 274c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 275c50d8ae3SPaolo Bonzini } 276c50d8ae3SPaolo Bonzini 2772f2fad08SBen Gardon void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 278c50d8ae3SPaolo Bonzini u64 start_gfn, u64 pages) 279c50d8ae3SPaolo Bonzini { 280c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 281c50d8ae3SPaolo Bonzini 282c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 283c50d8ae3SPaolo Bonzini range.pages = pages; 284c50d8ae3SPaolo Bonzini 285c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_range(kvm, &range); 286c50d8ae3SPaolo Bonzini } 287c50d8ae3SPaolo Bonzini 2888f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2898f79b064SBen Gardon unsigned int access) 2908f79b064SBen Gardon { 291c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2928f79b064SBen Gardon 293c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 294c236d962SSean Christopherson mmu_spte_set(sptep, spte); 295c50d8ae3SPaolo Bonzini } 296c50d8ae3SPaolo Bonzini 297c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 298c50d8ae3SPaolo Bonzini { 299c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 300c50d8ae3SPaolo Bonzini 3018a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 302c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 303c50d8ae3SPaolo Bonzini 304c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 305c50d8ae3SPaolo Bonzini } 306c50d8ae3SPaolo Bonzini 307c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 308c50d8ae3SPaolo Bonzini { 309c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 310c50d8ae3SPaolo Bonzini } 311c50d8ae3SPaolo Bonzini 312c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 313c50d8ae3SPaolo Bonzini { 314c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 315c50d8ae3SPaolo Bonzini 316c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 317c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 318c50d8ae3SPaolo Bonzini return false; 319c50d8ae3SPaolo Bonzini 320c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 321c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 322c50d8ae3SPaolo Bonzini 323c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 324c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 325c50d8ae3SPaolo Bonzini } 326c50d8ae3SPaolo Bonzini 327c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 328c50d8ae3SPaolo Bonzini { 329c50d8ae3SPaolo Bonzini return 1; 330c50d8ae3SPaolo Bonzini } 331c50d8ae3SPaolo Bonzini 332c50d8ae3SPaolo Bonzini static gfn_t pse36_gfn_delta(u32 gpte) 333c50d8ae3SPaolo Bonzini { 334c50d8ae3SPaolo Bonzini int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT; 335c50d8ae3SPaolo Bonzini 336c50d8ae3SPaolo Bonzini return (gpte & PT32_DIR_PSE36_MASK) << shift; 337c50d8ae3SPaolo Bonzini } 338c50d8ae3SPaolo Bonzini 339c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 340c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 341c50d8ae3SPaolo Bonzini { 342c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 343c50d8ae3SPaolo Bonzini } 344c50d8ae3SPaolo Bonzini 345c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 346c50d8ae3SPaolo Bonzini { 347c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 348c50d8ae3SPaolo Bonzini } 349c50d8ae3SPaolo Bonzini 350c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 351c50d8ae3SPaolo Bonzini { 352c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 353c50d8ae3SPaolo Bonzini } 354c50d8ae3SPaolo Bonzini 355c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 356c50d8ae3SPaolo Bonzini { 357c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 358c50d8ae3SPaolo Bonzini } 359c50d8ae3SPaolo Bonzini #else 360c50d8ae3SPaolo Bonzini union split_spte { 361c50d8ae3SPaolo Bonzini struct { 362c50d8ae3SPaolo Bonzini u32 spte_low; 363c50d8ae3SPaolo Bonzini u32 spte_high; 364c50d8ae3SPaolo Bonzini }; 365c50d8ae3SPaolo Bonzini u64 spte; 366c50d8ae3SPaolo Bonzini }; 367c50d8ae3SPaolo Bonzini 368c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 369c50d8ae3SPaolo Bonzini { 37057354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 371c50d8ae3SPaolo Bonzini 372c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 373c50d8ae3SPaolo Bonzini return; 374c50d8ae3SPaolo Bonzini 375c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 376c50d8ae3SPaolo Bonzini smp_wmb(); 377c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 378c50d8ae3SPaolo Bonzini } 379c50d8ae3SPaolo Bonzini 380c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 381c50d8ae3SPaolo Bonzini { 382c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 383c50d8ae3SPaolo Bonzini 384c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 385c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 386c50d8ae3SPaolo Bonzini 387c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 388c50d8ae3SPaolo Bonzini 389c50d8ae3SPaolo Bonzini /* 390c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 391c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 392c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 393c50d8ae3SPaolo Bonzini */ 394c50d8ae3SPaolo Bonzini smp_wmb(); 395c50d8ae3SPaolo Bonzini 396c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 397c50d8ae3SPaolo Bonzini } 398c50d8ae3SPaolo Bonzini 399c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 400c50d8ae3SPaolo Bonzini { 401c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 402c50d8ae3SPaolo Bonzini 403c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 404c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 405c50d8ae3SPaolo Bonzini 406c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 407c50d8ae3SPaolo Bonzini 408c50d8ae3SPaolo Bonzini /* 409c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 410c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 411c50d8ae3SPaolo Bonzini */ 412c50d8ae3SPaolo Bonzini smp_wmb(); 413c50d8ae3SPaolo Bonzini 414c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 415c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 416c50d8ae3SPaolo Bonzini } 417c50d8ae3SPaolo Bonzini 418c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 419c50d8ae3SPaolo Bonzini { 420c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 421c50d8ae3SPaolo Bonzini 422c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 423c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 424c50d8ae3SPaolo Bonzini 425c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 426c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 427c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 428c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 429c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 430c50d8ae3SPaolo Bonzini 431c50d8ae3SPaolo Bonzini return orig.spte; 432c50d8ae3SPaolo Bonzini } 433c50d8ae3SPaolo Bonzini 434c50d8ae3SPaolo Bonzini /* 435c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 436c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 437c50d8ae3SPaolo Bonzini * 438c50d8ae3SPaolo Bonzini * An spte tlb flush may be pending, because kvm_set_pte_rmapp 439c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 440c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 441c50d8ae3SPaolo Bonzini * 442c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 443c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 444c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 445c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 446c50d8ae3SPaolo Bonzini * 447c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 448c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 449c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 450c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 451c50d8ae3SPaolo Bonzini */ 452c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 453c50d8ae3SPaolo Bonzini { 45457354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 455c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 456c50d8ae3SPaolo Bonzini int count; 457c50d8ae3SPaolo Bonzini 458c50d8ae3SPaolo Bonzini retry: 459c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 460c50d8ae3SPaolo Bonzini smp_rmb(); 461c50d8ae3SPaolo Bonzini 462c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 463c50d8ae3SPaolo Bonzini smp_rmb(); 464c50d8ae3SPaolo Bonzini 465c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 466c50d8ae3SPaolo Bonzini smp_rmb(); 467c50d8ae3SPaolo Bonzini 468c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 469c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 470c50d8ae3SPaolo Bonzini goto retry; 471c50d8ae3SPaolo Bonzini 472c50d8ae3SPaolo Bonzini return spte.spte; 473c50d8ae3SPaolo Bonzini } 474c50d8ae3SPaolo Bonzini #endif 475c50d8ae3SPaolo Bonzini 476c50d8ae3SPaolo Bonzini static bool spte_has_volatile_bits(u64 spte) 477c50d8ae3SPaolo Bonzini { 478c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(spte)) 479c50d8ae3SPaolo Bonzini return false; 480c50d8ae3SPaolo Bonzini 481c50d8ae3SPaolo Bonzini /* 482c50d8ae3SPaolo Bonzini * Always atomically update spte if it can be updated 483c50d8ae3SPaolo Bonzini * out of mmu-lock, it can ensure dirty bit is not lost, 484c50d8ae3SPaolo Bonzini * also, it can help us to get a stable is_writable_pte() 485c50d8ae3SPaolo Bonzini * to ensure tlb flush is not missed. 486c50d8ae3SPaolo Bonzini */ 487c50d8ae3SPaolo Bonzini if (spte_can_locklessly_be_made_writable(spte) || 488c50d8ae3SPaolo Bonzini is_access_track_spte(spte)) 489c50d8ae3SPaolo Bonzini return true; 490c50d8ae3SPaolo Bonzini 491c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 492c50d8ae3SPaolo Bonzini if ((spte & shadow_accessed_mask) == 0 || 493c50d8ae3SPaolo Bonzini (is_writable_pte(spte) && (spte & shadow_dirty_mask) == 0)) 494c50d8ae3SPaolo Bonzini return true; 495c50d8ae3SPaolo Bonzini } 496c50d8ae3SPaolo Bonzini 497c50d8ae3SPaolo Bonzini return false; 498c50d8ae3SPaolo Bonzini } 499c50d8ae3SPaolo Bonzini 500c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 501c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 502c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 503c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 504c50d8ae3SPaolo Bonzini * the spte. 505c50d8ae3SPaolo Bonzini */ 506c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 507c50d8ae3SPaolo Bonzini { 508c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 509c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 510c50d8ae3SPaolo Bonzini } 511c50d8ae3SPaolo Bonzini 512c50d8ae3SPaolo Bonzini /* 513c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 514c50d8ae3SPaolo Bonzini * accessed/dirty status. 515c50d8ae3SPaolo Bonzini */ 516c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 517c50d8ae3SPaolo Bonzini { 518c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 519c50d8ae3SPaolo Bonzini 520c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 521115111efSDavid Matlack check_spte_writable_invariants(new_spte); 522c50d8ae3SPaolo Bonzini 523c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 524c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 525c50d8ae3SPaolo Bonzini return old_spte; 526c50d8ae3SPaolo Bonzini } 527c50d8ae3SPaolo Bonzini 528c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 529c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 530c50d8ae3SPaolo Bonzini else 531c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 532c50d8ae3SPaolo Bonzini 533c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 534c50d8ae3SPaolo Bonzini 535c50d8ae3SPaolo Bonzini return old_spte; 536c50d8ae3SPaolo Bonzini } 537c50d8ae3SPaolo Bonzini 538c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 539c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 540c50d8ae3SPaolo Bonzini * 54102844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 54202844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 54302844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 544c50d8ae3SPaolo Bonzini * 545c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 546c50d8ae3SPaolo Bonzini */ 547c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 548c50d8ae3SPaolo Bonzini { 549c50d8ae3SPaolo Bonzini bool flush = false; 550c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 551c50d8ae3SPaolo Bonzini 552c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 553c50d8ae3SPaolo Bonzini return false; 554c50d8ae3SPaolo Bonzini 555c50d8ae3SPaolo Bonzini /* 556c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 557c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 558c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 559c50d8ae3SPaolo Bonzini */ 560c50d8ae3SPaolo Bonzini if (spte_can_locklessly_be_made_writable(old_spte) && 561c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 562c50d8ae3SPaolo Bonzini flush = true; 563c50d8ae3SPaolo Bonzini 564c50d8ae3SPaolo Bonzini /* 565c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 566c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 567c50d8ae3SPaolo Bonzini */ 568c50d8ae3SPaolo Bonzini 569c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 570c50d8ae3SPaolo Bonzini flush = true; 571c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 572c50d8ae3SPaolo Bonzini } 573c50d8ae3SPaolo Bonzini 574c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 575c50d8ae3SPaolo Bonzini flush = true; 576c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 577c50d8ae3SPaolo Bonzini } 578c50d8ae3SPaolo Bonzini 579c50d8ae3SPaolo Bonzini return flush; 580c50d8ae3SPaolo Bonzini } 581c50d8ae3SPaolo Bonzini 582c50d8ae3SPaolo Bonzini /* 583c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 584c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 585c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5867fa2a347SSean Christopherson * Returns the old PTE. 587c50d8ae3SPaolo Bonzini */ 58871f51d2cSMingwei Zhang static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 589c50d8ae3SPaolo Bonzini { 590c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 591c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 59271f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 593c50d8ae3SPaolo Bonzini 594c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 595c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 596c50d8ae3SPaolo Bonzini else 597c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 598c50d8ae3SPaolo Bonzini 599c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 6007fa2a347SSean Christopherson return old_spte; 601c50d8ae3SPaolo Bonzini 60271f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 60371f51d2cSMingwei Zhang 604c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 605c50d8ae3SPaolo Bonzini 606c50d8ae3SPaolo Bonzini /* 607c50d8ae3SPaolo Bonzini * KVM does not hold the refcount of the page used by 608c50d8ae3SPaolo Bonzini * kvm mmu, before reclaiming the page, we should 609c50d8ae3SPaolo Bonzini * unmap it from mmu first. 610c50d8ae3SPaolo Bonzini */ 611c50d8ae3SPaolo Bonzini WARN_ON(!kvm_is_reserved_pfn(pfn) && !page_count(pfn_to_page(pfn))); 612c50d8ae3SPaolo Bonzini 613c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 614c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 615c50d8ae3SPaolo Bonzini 616c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 617c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 618c50d8ae3SPaolo Bonzini 6197fa2a347SSean Christopherson return old_spte; 620c50d8ae3SPaolo Bonzini } 621c50d8ae3SPaolo Bonzini 622c50d8ae3SPaolo Bonzini /* 623c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 624c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 625c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 626c50d8ae3SPaolo Bonzini */ 627c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 628c50d8ae3SPaolo Bonzini { 629c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 630c50d8ae3SPaolo Bonzini } 631c50d8ae3SPaolo Bonzini 632c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 633c50d8ae3SPaolo Bonzini { 634c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 635c50d8ae3SPaolo Bonzini } 636c50d8ae3SPaolo Bonzini 637c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 638c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 639c50d8ae3SPaolo Bonzini { 640c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 641c50d8ae3SPaolo Bonzini 642c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 643c50d8ae3SPaolo Bonzini return false; 644c50d8ae3SPaolo Bonzini 645c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 646c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 647c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 648c50d8ae3SPaolo Bonzini } else { 649c50d8ae3SPaolo Bonzini /* 650c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 651c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 652c50d8ae3SPaolo Bonzini */ 653c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 654c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 655c50d8ae3SPaolo Bonzini 656c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 657c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 658c50d8ae3SPaolo Bonzini } 659c50d8ae3SPaolo Bonzini 660c50d8ae3SPaolo Bonzini return true; 661c50d8ae3SPaolo Bonzini } 662c50d8ae3SPaolo Bonzini 663c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 664c50d8ae3SPaolo Bonzini { 665c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 666c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 667c5c8c7c5SDavid Matlack } else { 668c50d8ae3SPaolo Bonzini /* 669c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 670c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 671c50d8ae3SPaolo Bonzini */ 672c50d8ae3SPaolo Bonzini local_irq_disable(); 673c50d8ae3SPaolo Bonzini 674c50d8ae3SPaolo Bonzini /* 675c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 676c50d8ae3SPaolo Bonzini * to vcpu->mode. 677c50d8ae3SPaolo Bonzini */ 678c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 679c50d8ae3SPaolo Bonzini } 680c5c8c7c5SDavid Matlack } 681c50d8ae3SPaolo Bonzini 682c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 683c50d8ae3SPaolo Bonzini { 684c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 685c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 686c5c8c7c5SDavid Matlack } else { 687c50d8ae3SPaolo Bonzini /* 688c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 689c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 690c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 691c50d8ae3SPaolo Bonzini */ 692c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 693c50d8ae3SPaolo Bonzini local_irq_enable(); 694c50d8ae3SPaolo Bonzini } 695c5c8c7c5SDavid Matlack } 696c50d8ae3SPaolo Bonzini 697378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 698c50d8ae3SPaolo Bonzini { 699c50d8ae3SPaolo Bonzini int r; 700c50d8ae3SPaolo Bonzini 701531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 70294ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 703531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 704c50d8ae3SPaolo Bonzini if (r) 705c50d8ae3SPaolo Bonzini return r; 70694ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 707171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 708171a90d7SSean Christopherson if (r) 709171a90d7SSean Christopherson return r; 710378f5cd6SSean Christopherson if (maybe_indirect) { 71194ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_cache, 712171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 713c50d8ae3SPaolo Bonzini if (r) 714c50d8ae3SPaolo Bonzini return r; 715378f5cd6SSean Christopherson } 71694ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 717531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 718c50d8ae3SPaolo Bonzini } 719c50d8ae3SPaolo Bonzini 720c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 721c50d8ae3SPaolo Bonzini { 72294ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 72394ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 72494ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_gfn_array_cache); 72594ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 726c50d8ae3SPaolo Bonzini } 727c50d8ae3SPaolo Bonzini 728c50d8ae3SPaolo Bonzini static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu) 729c50d8ae3SPaolo Bonzini { 73094ce87efSSean Christopherson return kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_list_desc_cache); 731c50d8ae3SPaolo Bonzini } 732c50d8ae3SPaolo Bonzini 733c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 734c50d8ae3SPaolo Bonzini { 735c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 736c50d8ae3SPaolo Bonzini } 737c50d8ae3SPaolo Bonzini 738c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 739c50d8ae3SPaolo Bonzini { 740c50d8ae3SPaolo Bonzini if (!sp->role.direct) 741c50d8ae3SPaolo Bonzini return sp->gfns[index]; 742c50d8ae3SPaolo Bonzini 743c50d8ae3SPaolo Bonzini return sp->gfn + (index << ((sp->role.level - 1) * PT64_LEVEL_BITS)); 744c50d8ae3SPaolo Bonzini } 745c50d8ae3SPaolo Bonzini 746c50d8ae3SPaolo Bonzini static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn) 747c50d8ae3SPaolo Bonzini { 748c50d8ae3SPaolo Bonzini if (!sp->role.direct) { 749c50d8ae3SPaolo Bonzini sp->gfns[index] = gfn; 750c50d8ae3SPaolo Bonzini return; 751c50d8ae3SPaolo Bonzini } 752c50d8ae3SPaolo Bonzini 753c50d8ae3SPaolo Bonzini if (WARN_ON(gfn != kvm_mmu_page_get_gfn(sp, index))) 754c50d8ae3SPaolo Bonzini pr_err_ratelimited("gfn mismatch under direct page %llx " 755c50d8ae3SPaolo Bonzini "(expected %llx, got %llx)\n", 756c50d8ae3SPaolo Bonzini sp->gfn, 757c50d8ae3SPaolo Bonzini kvm_mmu_page_get_gfn(sp, index), gfn); 758c50d8ae3SPaolo Bonzini } 759c50d8ae3SPaolo Bonzini 760c50d8ae3SPaolo Bonzini /* 761c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 762c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 763c50d8ae3SPaolo Bonzini */ 764c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7658ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 766c50d8ae3SPaolo Bonzini { 767c50d8ae3SPaolo Bonzini unsigned long idx; 768c50d8ae3SPaolo Bonzini 769c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 770c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 771c50d8ae3SPaolo Bonzini } 772c50d8ae3SPaolo Bonzini 773269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 774c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 775c50d8ae3SPaolo Bonzini { 776c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 777c50d8ae3SPaolo Bonzini int i; 778c50d8ae3SPaolo Bonzini 7793bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 780c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 781c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 782c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 783c50d8ae3SPaolo Bonzini } 784c50d8ae3SPaolo Bonzini } 785c50d8ae3SPaolo Bonzini 786269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 787c50d8ae3SPaolo Bonzini { 788c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 789c50d8ae3SPaolo Bonzini } 790c50d8ae3SPaolo Bonzini 791269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 792c50d8ae3SPaolo Bonzini { 793c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 794c50d8ae3SPaolo Bonzini } 795c50d8ae3SPaolo Bonzini 796c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 797c50d8ae3SPaolo Bonzini { 798c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 799c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 800c50d8ae3SPaolo Bonzini gfn_t gfn; 801c50d8ae3SPaolo Bonzini 802c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 803c50d8ae3SPaolo Bonzini gfn = sp->gfn; 804c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 805c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 806c50d8ae3SPaolo Bonzini 807c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8083bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 809c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 810c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 811c50d8ae3SPaolo Bonzini 812c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 813c50d8ae3SPaolo Bonzini } 814c50d8ae3SPaolo Bonzini 81529cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 816c50d8ae3SPaolo Bonzini { 817c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 818c50d8ae3SPaolo Bonzini return; 819c50d8ae3SPaolo Bonzini 820c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 821c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 822c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 823c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 824c50d8ae3SPaolo Bonzini } 825c50d8ae3SPaolo Bonzini 826c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 827c50d8ae3SPaolo Bonzini { 828c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 829c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 830c50d8ae3SPaolo Bonzini gfn_t gfn; 831c50d8ae3SPaolo Bonzini 832c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 833c50d8ae3SPaolo Bonzini gfn = sp->gfn; 834c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 835c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8363bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 837c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 838c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 839c50d8ae3SPaolo Bonzini 840c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 841c50d8ae3SPaolo Bonzini } 842c50d8ae3SPaolo Bonzini 84329cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 844c50d8ae3SPaolo Bonzini { 845c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 846c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 847c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 848c50d8ae3SPaolo Bonzini } 849c50d8ae3SPaolo Bonzini 850c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 851c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 852c50d8ae3SPaolo Bonzini bool no_dirty_log) 853c50d8ae3SPaolo Bonzini { 854c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 855c50d8ae3SPaolo Bonzini 856c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 85791b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 85891b0d268SPaolo Bonzini return NULL; 859044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 86091b0d268SPaolo Bonzini return NULL; 861c50d8ae3SPaolo Bonzini 862c50d8ae3SPaolo Bonzini return slot; 863c50d8ae3SPaolo Bonzini } 864c50d8ae3SPaolo Bonzini 865c50d8ae3SPaolo Bonzini /* 866c50d8ae3SPaolo Bonzini * About rmap_head encoding: 867c50d8ae3SPaolo Bonzini * 868c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 869c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 870c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 871c50d8ae3SPaolo Bonzini */ 872c50d8ae3SPaolo Bonzini 873c50d8ae3SPaolo Bonzini /* 874c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 875c50d8ae3SPaolo Bonzini */ 876c50d8ae3SPaolo Bonzini static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte, 877c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 878c50d8ae3SPaolo Bonzini { 879c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 88013236e25SPeter Xu int count = 0; 881c50d8ae3SPaolo Bonzini 882c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 883805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 884c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 885c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 886805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 887c50d8ae3SPaolo Bonzini desc = mmu_alloc_pte_list_desc(vcpu); 888c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 889c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 89013236e25SPeter Xu desc->spte_count = 2; 891c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 892c50d8ae3SPaolo Bonzini ++count; 893c50d8ae3SPaolo Bonzini } else { 894805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 895c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 89613236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 897c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 898c6c4f961SLi RongQing if (!desc->more) { 899c50d8ae3SPaolo Bonzini desc->more = mmu_alloc_pte_list_desc(vcpu); 900c50d8ae3SPaolo Bonzini desc = desc->more; 90113236e25SPeter Xu desc->spte_count = 0; 902c6c4f961SLi RongQing break; 903c6c4f961SLi RongQing } 904c6c4f961SLi RongQing desc = desc->more; 905c50d8ae3SPaolo Bonzini } 90613236e25SPeter Xu count += desc->spte_count; 90713236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 908c50d8ae3SPaolo Bonzini } 909c50d8ae3SPaolo Bonzini return count; 910c50d8ae3SPaolo Bonzini } 911c50d8ae3SPaolo Bonzini 912c50d8ae3SPaolo Bonzini static void 913c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 914c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 915c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 916c50d8ae3SPaolo Bonzini { 91713236e25SPeter Xu int j = desc->spte_count - 1; 918c50d8ae3SPaolo Bonzini 919c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 920c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 92113236e25SPeter Xu desc->spte_count--; 92213236e25SPeter Xu if (desc->spte_count) 923c50d8ae3SPaolo Bonzini return; 924c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 925fe3c2b4cSMiaohe Lin rmap_head->val = 0; 926c50d8ae3SPaolo Bonzini else 927c50d8ae3SPaolo Bonzini if (prev_desc) 928c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 929c50d8ae3SPaolo Bonzini else 930c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 931c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 932c50d8ae3SPaolo Bonzini } 933c50d8ae3SPaolo Bonzini 934c50d8ae3SPaolo Bonzini static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 935c50d8ae3SPaolo Bonzini { 936c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 937c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 938c50d8ae3SPaolo Bonzini int i; 939c50d8ae3SPaolo Bonzini 940c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 941c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 942c50d8ae3SPaolo Bonzini BUG(); 943c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 944805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 945c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 946c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 947c50d8ae3SPaolo Bonzini BUG(); 948c50d8ae3SPaolo Bonzini } 949c50d8ae3SPaolo Bonzini rmap_head->val = 0; 950c50d8ae3SPaolo Bonzini } else { 951805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 952c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 953c50d8ae3SPaolo Bonzini prev_desc = NULL; 954c50d8ae3SPaolo Bonzini while (desc) { 95513236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 956c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 957c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 958c50d8ae3SPaolo Bonzini desc, i, prev_desc); 959c50d8ae3SPaolo Bonzini return; 960c50d8ae3SPaolo Bonzini } 961c50d8ae3SPaolo Bonzini } 962c50d8ae3SPaolo Bonzini prev_desc = desc; 963c50d8ae3SPaolo Bonzini desc = desc->more; 964c50d8ae3SPaolo Bonzini } 965c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 966c50d8ae3SPaolo Bonzini BUG(); 967c50d8ae3SPaolo Bonzini } 968c50d8ae3SPaolo Bonzini } 969c50d8ae3SPaolo Bonzini 97071f51d2cSMingwei Zhang static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 97171f51d2cSMingwei Zhang u64 *sptep) 972c50d8ae3SPaolo Bonzini { 97371f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 974c50d8ae3SPaolo Bonzini __pte_list_remove(sptep, rmap_head); 975c50d8ae3SPaolo Bonzini } 976c50d8ae3SPaolo Bonzini 977a75b5404SPeter Xu /* Return true if rmap existed, false otherwise */ 97871f51d2cSMingwei Zhang static bool pte_list_destroy(struct kvm *kvm, struct kvm_rmap_head *rmap_head) 979a75b5404SPeter Xu { 980a75b5404SPeter Xu struct pte_list_desc *desc, *next; 981a75b5404SPeter Xu int i; 982a75b5404SPeter Xu 983a75b5404SPeter Xu if (!rmap_head->val) 984a75b5404SPeter Xu return false; 985a75b5404SPeter Xu 986a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 98771f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 988a75b5404SPeter Xu goto out; 989a75b5404SPeter Xu } 990a75b5404SPeter Xu 991a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 992a75b5404SPeter Xu 993a75b5404SPeter Xu for (; desc; desc = next) { 994a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 99571f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 996a75b5404SPeter Xu next = desc->more; 997a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 998a75b5404SPeter Xu } 999a75b5404SPeter Xu out: 1000a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 1001a75b5404SPeter Xu rmap_head->val = 0; 1002a75b5404SPeter Xu return true; 1003a75b5404SPeter Xu } 1004a75b5404SPeter Xu 10053bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10063bcd0662SPeter Xu { 10073bcd0662SPeter Xu struct pte_list_desc *desc; 10083bcd0662SPeter Xu unsigned int count = 0; 10093bcd0662SPeter Xu 10103bcd0662SPeter Xu if (!rmap_head->val) 10113bcd0662SPeter Xu return 0; 10123bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10133bcd0662SPeter Xu return 1; 10143bcd0662SPeter Xu 10153bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10163bcd0662SPeter Xu 10173bcd0662SPeter Xu while (desc) { 10183bcd0662SPeter Xu count += desc->spte_count; 10193bcd0662SPeter Xu desc = desc->more; 10203bcd0662SPeter Xu } 10213bcd0662SPeter Xu 10223bcd0662SPeter Xu return count; 10233bcd0662SPeter Xu } 10243bcd0662SPeter Xu 102593e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1026269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1027c50d8ae3SPaolo Bonzini { 1028c50d8ae3SPaolo Bonzini unsigned long idx; 1029c50d8ae3SPaolo Bonzini 1030c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10313bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1032c50d8ae3SPaolo Bonzini } 1033c50d8ae3SPaolo Bonzini 1034c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1035c50d8ae3SPaolo Bonzini { 1036356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1037c50d8ae3SPaolo Bonzini 1038356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 103994ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1040c50d8ae3SPaolo Bonzini } 1041c50d8ae3SPaolo Bonzini 1042c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1043c50d8ae3SPaolo Bonzini { 1044601f8af0SDavid Matlack struct kvm_memslots *slots; 1045601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1046c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1047c50d8ae3SPaolo Bonzini gfn_t gfn; 1048c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1049c50d8ae3SPaolo Bonzini 105057354682SSean Christopherson sp = sptep_to_sp(spte); 1051c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt); 1052601f8af0SDavid Matlack 1053601f8af0SDavid Matlack /* 105468be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 105568be1306SDavid Matlack * so we have to determine which memslots to use based on context 105668be1306SDavid Matlack * information in sp->role. 1057601f8af0SDavid Matlack */ 1058601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1059601f8af0SDavid Matlack 1060601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 106193e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1062601f8af0SDavid Matlack 1063c50d8ae3SPaolo Bonzini __pte_list_remove(spte, rmap_head); 1064c50d8ae3SPaolo Bonzini } 1065c50d8ae3SPaolo Bonzini 1066c50d8ae3SPaolo Bonzini /* 1067c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1068c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1069c50d8ae3SPaolo Bonzini */ 1070c50d8ae3SPaolo Bonzini struct rmap_iterator { 1071c50d8ae3SPaolo Bonzini /* private fields */ 1072c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1073c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1074c50d8ae3SPaolo Bonzini }; 1075c50d8ae3SPaolo Bonzini 1076c50d8ae3SPaolo Bonzini /* 1077c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1078c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10790a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1080c50d8ae3SPaolo Bonzini * 1081c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1082c50d8ae3SPaolo Bonzini */ 1083c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1084c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1085c50d8ae3SPaolo Bonzini { 1086c50d8ae3SPaolo Bonzini u64 *sptep; 1087c50d8ae3SPaolo Bonzini 1088c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1089c50d8ae3SPaolo Bonzini return NULL; 1090c50d8ae3SPaolo Bonzini 1091c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1092c50d8ae3SPaolo Bonzini iter->desc = NULL; 1093c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1094c50d8ae3SPaolo Bonzini goto out; 1095c50d8ae3SPaolo Bonzini } 1096c50d8ae3SPaolo Bonzini 1097c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1098c50d8ae3SPaolo Bonzini iter->pos = 0; 1099c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1100c50d8ae3SPaolo Bonzini out: 1101c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1102c50d8ae3SPaolo Bonzini return sptep; 1103c50d8ae3SPaolo Bonzini } 1104c50d8ae3SPaolo Bonzini 1105c50d8ae3SPaolo Bonzini /* 1106c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1107c50d8ae3SPaolo Bonzini * 1108c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1109c50d8ae3SPaolo Bonzini */ 1110c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1111c50d8ae3SPaolo Bonzini { 1112c50d8ae3SPaolo Bonzini u64 *sptep; 1113c50d8ae3SPaolo Bonzini 1114c50d8ae3SPaolo Bonzini if (iter->desc) { 1115c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1116c50d8ae3SPaolo Bonzini ++iter->pos; 1117c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1118c50d8ae3SPaolo Bonzini if (sptep) 1119c50d8ae3SPaolo Bonzini goto out; 1120c50d8ae3SPaolo Bonzini } 1121c50d8ae3SPaolo Bonzini 1122c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1123c50d8ae3SPaolo Bonzini 1124c50d8ae3SPaolo Bonzini if (iter->desc) { 1125c50d8ae3SPaolo Bonzini iter->pos = 0; 1126c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1127c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1128c50d8ae3SPaolo Bonzini goto out; 1129c50d8ae3SPaolo Bonzini } 1130c50d8ae3SPaolo Bonzini } 1131c50d8ae3SPaolo Bonzini 1132c50d8ae3SPaolo Bonzini return NULL; 1133c50d8ae3SPaolo Bonzini out: 1134c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1135c50d8ae3SPaolo Bonzini return sptep; 1136c50d8ae3SPaolo Bonzini } 1137c50d8ae3SPaolo Bonzini 1138c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1139c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1140c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1141c50d8ae3SPaolo Bonzini 1142c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1143c50d8ae3SPaolo Bonzini { 114471f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11457fa2a347SSean Christopherson 11467fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1147c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1148c50d8ae3SPaolo Bonzini } 1149c50d8ae3SPaolo Bonzini 1150c50d8ae3SPaolo Bonzini 1151c50d8ae3SPaolo Bonzini static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) 1152c50d8ae3SPaolo Bonzini { 1153c50d8ae3SPaolo Bonzini if (is_large_pte(*sptep)) { 115457354682SSean Christopherson WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); 1155c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 1156c50d8ae3SPaolo Bonzini return true; 1157c50d8ae3SPaolo Bonzini } 1158c50d8ae3SPaolo Bonzini 1159c50d8ae3SPaolo Bonzini return false; 1160c50d8ae3SPaolo Bonzini } 1161c50d8ae3SPaolo Bonzini 1162c50d8ae3SPaolo Bonzini static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) 1163c50d8ae3SPaolo Bonzini { 1164c50d8ae3SPaolo Bonzini if (__drop_large_spte(vcpu->kvm, sptep)) { 116557354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 1166c50d8ae3SPaolo Bonzini 1167c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, 1168c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1169c50d8ae3SPaolo Bonzini } 1170c50d8ae3SPaolo Bonzini } 1171c50d8ae3SPaolo Bonzini 1172c50d8ae3SPaolo Bonzini /* 1173c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1174c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1175c50d8ae3SPaolo Bonzini * 1176c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1177c50d8ae3SPaolo Bonzini * protection: 1178c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1179c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1180c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1181c50d8ae3SPaolo Bonzini * shadow page. 1182c50d8ae3SPaolo Bonzini * 1183c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1184c50d8ae3SPaolo Bonzini */ 1185c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1186c50d8ae3SPaolo Bonzini { 1187c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1188c50d8ae3SPaolo Bonzini 1189c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1190c50d8ae3SPaolo Bonzini !(pt_protect && spte_can_locklessly_be_made_writable(spte))) 1191c50d8ae3SPaolo Bonzini return false; 1192c50d8ae3SPaolo Bonzini 1193805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1194c50d8ae3SPaolo Bonzini 1195c50d8ae3SPaolo Bonzini if (pt_protect) 11965fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1197c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1198c50d8ae3SPaolo Bonzini 1199c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1200c50d8ae3SPaolo Bonzini } 1201c50d8ae3SPaolo Bonzini 12021346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1203c50d8ae3SPaolo Bonzini bool pt_protect) 1204c50d8ae3SPaolo Bonzini { 1205c50d8ae3SPaolo Bonzini u64 *sptep; 1206c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1207c50d8ae3SPaolo Bonzini bool flush = false; 1208c50d8ae3SPaolo Bonzini 1209c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1210c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1211c50d8ae3SPaolo Bonzini 1212c50d8ae3SPaolo Bonzini return flush; 1213c50d8ae3SPaolo Bonzini } 1214c50d8ae3SPaolo Bonzini 1215c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1216c50d8ae3SPaolo Bonzini { 1217c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1218c50d8ae3SPaolo Bonzini 1219805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1220c50d8ae3SPaolo Bonzini 1221c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1222c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1223c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1224c50d8ae3SPaolo Bonzini } 1225c50d8ae3SPaolo Bonzini 1226c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1227c50d8ae3SPaolo Bonzini { 1228c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1229c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1230c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1231c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1232c50d8ae3SPaolo Bonzini 1233c50d8ae3SPaolo Bonzini return was_writable; 1234c50d8ae3SPaolo Bonzini } 1235c50d8ae3SPaolo Bonzini 1236c50d8ae3SPaolo Bonzini /* 1237c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1238c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1239c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1240c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1241c50d8ae3SPaolo Bonzini */ 12420a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1243269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1244c50d8ae3SPaolo Bonzini { 1245c50d8ae3SPaolo Bonzini u64 *sptep; 1246c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1247c50d8ae3SPaolo Bonzini bool flush = false; 1248c50d8ae3SPaolo Bonzini 1249c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1250c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1251c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1252c50d8ae3SPaolo Bonzini else 1253c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1254c50d8ae3SPaolo Bonzini 1255c50d8ae3SPaolo Bonzini return flush; 1256c50d8ae3SPaolo Bonzini } 1257c50d8ae3SPaolo Bonzini 1258c50d8ae3SPaolo Bonzini /** 1259c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1260c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1261c50d8ae3SPaolo Bonzini * @slot: slot to protect 1262c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1263c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1264c50d8ae3SPaolo Bonzini * 126589212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1266c50d8ae3SPaolo Bonzini */ 1267c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1268c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1269c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1270c50d8ae3SPaolo Bonzini { 1271c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1272c50d8ae3SPaolo Bonzini 1273897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1274a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1275a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1276e2209710SBen Gardon 1277e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1278e2209710SBen Gardon return; 1279e2209710SBen Gardon 1280c50d8ae3SPaolo Bonzini while (mask) { 128193e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12823bae0459SSean Christopherson PG_LEVEL_4K, slot); 12831346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1284c50d8ae3SPaolo Bonzini 1285c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1286c50d8ae3SPaolo Bonzini mask &= mask - 1; 1287c50d8ae3SPaolo Bonzini } 1288c50d8ae3SPaolo Bonzini } 1289c50d8ae3SPaolo Bonzini 1290c50d8ae3SPaolo Bonzini /** 1291c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1292c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1293c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1294c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1295c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1296c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1297c50d8ae3SPaolo Bonzini * 1298c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1299c50d8ae3SPaolo Bonzini */ 1300a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1301c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1302c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1303c50d8ae3SPaolo Bonzini { 1304c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1305c50d8ae3SPaolo Bonzini 1306897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1307a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1308a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1309e2209710SBen Gardon 1310e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1311e2209710SBen Gardon return; 1312e2209710SBen Gardon 1313c50d8ae3SPaolo Bonzini while (mask) { 131493e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13153bae0459SSean Christopherson PG_LEVEL_4K, slot); 13160a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1317c50d8ae3SPaolo Bonzini 1318c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1319c50d8ae3SPaolo Bonzini mask &= mask - 1; 1320c50d8ae3SPaolo Bonzini } 1321c50d8ae3SPaolo Bonzini } 1322c50d8ae3SPaolo Bonzini 1323c50d8ae3SPaolo Bonzini /** 1324c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1325c50d8ae3SPaolo Bonzini * PT level pages. 1326c50d8ae3SPaolo Bonzini * 1327c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1328c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1329c50d8ae3SPaolo Bonzini * 133089212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 133189212919SKeqian Zhu * have such mappings. 1332c50d8ae3SPaolo Bonzini */ 1333c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1334c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1335c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1336c50d8ae3SPaolo Bonzini { 133789212919SKeqian Zhu /* 133889212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 133989212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 134089212919SKeqian Zhu * are split to 4K on the first write. 134189212919SKeqian Zhu * 134289212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 134389212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 134489212919SKeqian Zhu * pages. 134589212919SKeqian Zhu */ 134689212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 134789212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 134889212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 134989212919SKeqian Zhu 1350cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1351cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1352cb00a70bSDavid Matlack 135389212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 135489212919SKeqian Zhu 135589212919SKeqian Zhu /* Cross two large pages? */ 135689212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 135789212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 135889212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 135989212919SKeqian Zhu PG_LEVEL_2M); 136089212919SKeqian Zhu } 136189212919SKeqian Zhu 136289212919SKeqian Zhu /* Now handle 4K PTEs. */ 1363a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1364a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1365c50d8ae3SPaolo Bonzini else 1366c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1367c50d8ae3SPaolo Bonzini } 1368c50d8ae3SPaolo Bonzini 1369fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1370fb04a1edSPeter Xu { 13716dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1372fb04a1edSPeter Xu } 1373fb04a1edSPeter Xu 1374c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13753ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13763ad93562SKeqian Zhu int min_level) 1377c50d8ae3SPaolo Bonzini { 1378c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1379c50d8ae3SPaolo Bonzini int i; 1380c50d8ae3SPaolo Bonzini bool write_protected = false; 1381c50d8ae3SPaolo Bonzini 1382e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13833ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 138493e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13851346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1386c50d8ae3SPaolo Bonzini } 1387e2209710SBen Gardon } 1388c50d8ae3SPaolo Bonzini 1389897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 139046044f72SBen Gardon write_protected |= 13913ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 139246044f72SBen Gardon 1393c50d8ae3SPaolo Bonzini return write_protected; 1394c50d8ae3SPaolo Bonzini } 1395c50d8ae3SPaolo Bonzini 1396cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1397c50d8ae3SPaolo Bonzini { 1398c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1399c50d8ae3SPaolo Bonzini 1400c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 14013ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1402c50d8ae3SPaolo Bonzini } 1403c50d8ae3SPaolo Bonzini 14040a234f5dSSean Christopherson static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1405269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1406c50d8ae3SPaolo Bonzini { 140771f51d2cSMingwei Zhang return pte_list_destroy(kvm, rmap_head); 1408c50d8ae3SPaolo Bonzini } 1409c50d8ae3SPaolo Bonzini 14103039bcc7SSean Christopherson static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1411c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14123039bcc7SSean Christopherson pte_t unused) 1413c50d8ae3SPaolo Bonzini { 14140a234f5dSSean Christopherson return kvm_zap_rmapp(kvm, rmap_head, slot); 1415c50d8ae3SPaolo Bonzini } 1416c50d8ae3SPaolo Bonzini 14173039bcc7SSean Christopherson static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1418c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14193039bcc7SSean Christopherson pte_t pte) 1420c50d8ae3SPaolo Bonzini { 1421c50d8ae3SPaolo Bonzini u64 *sptep; 1422c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 142398a26b69SVihas Mak bool need_flush = false; 1424c50d8ae3SPaolo Bonzini u64 new_spte; 1425c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1426c50d8ae3SPaolo Bonzini 14273039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14283039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1429c50d8ae3SPaolo Bonzini 1430c50d8ae3SPaolo Bonzini restart: 1431c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1432805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1433c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1434c50d8ae3SPaolo Bonzini 143598a26b69SVihas Mak need_flush = true; 1436c50d8ae3SPaolo Bonzini 14373039bcc7SSean Christopherson if (pte_write(pte)) { 143871f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 1439c50d8ae3SPaolo Bonzini goto restart; 1440c50d8ae3SPaolo Bonzini } else { 1441cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1442cb3eedabSPaolo Bonzini *sptep, new_pfn); 1443c50d8ae3SPaolo Bonzini 144471f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1445c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1446c50d8ae3SPaolo Bonzini } 1447c50d8ae3SPaolo Bonzini } 1448c50d8ae3SPaolo Bonzini 1449c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1450c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 145198a26b69SVihas Mak return false; 1452c50d8ae3SPaolo Bonzini } 1453c50d8ae3SPaolo Bonzini 1454c50d8ae3SPaolo Bonzini return need_flush; 1455c50d8ae3SPaolo Bonzini } 1456c50d8ae3SPaolo Bonzini 1457c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1458c50d8ae3SPaolo Bonzini /* input fields. */ 1459269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1460c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1461c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1462c50d8ae3SPaolo Bonzini int start_level; 1463c50d8ae3SPaolo Bonzini int end_level; 1464c50d8ae3SPaolo Bonzini 1465c50d8ae3SPaolo Bonzini /* output fields. */ 1466c50d8ae3SPaolo Bonzini gfn_t gfn; 1467c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1468c50d8ae3SPaolo Bonzini int level; 1469c50d8ae3SPaolo Bonzini 1470c50d8ae3SPaolo Bonzini /* private field. */ 1471c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1472c50d8ae3SPaolo Bonzini }; 1473c50d8ae3SPaolo Bonzini 1474c50d8ae3SPaolo Bonzini static void 1475c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1476c50d8ae3SPaolo Bonzini { 1477c50d8ae3SPaolo Bonzini iterator->level = level; 1478c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 147993e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 148093e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1481c50d8ae3SPaolo Bonzini } 1482c50d8ae3SPaolo Bonzini 1483c50d8ae3SPaolo Bonzini static void 1484c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1485269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1486c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1487c50d8ae3SPaolo Bonzini { 1488c50d8ae3SPaolo Bonzini iterator->slot = slot; 1489c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1490c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1491c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1492c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1493c50d8ae3SPaolo Bonzini 1494c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1495c50d8ae3SPaolo Bonzini } 1496c50d8ae3SPaolo Bonzini 1497c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1498c50d8ae3SPaolo Bonzini { 1499c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1500c50d8ae3SPaolo Bonzini } 1501c50d8ae3SPaolo Bonzini 1502c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1503c50d8ae3SPaolo Bonzini { 1504c50d8ae3SPaolo Bonzini if (++iterator->rmap <= iterator->end_rmap) { 1505c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 1506c50d8ae3SPaolo Bonzini return; 1507c50d8ae3SPaolo Bonzini } 1508c50d8ae3SPaolo Bonzini 1509c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1510c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1511c50d8ae3SPaolo Bonzini return; 1512c50d8ae3SPaolo Bonzini } 1513c50d8ae3SPaolo Bonzini 1514c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1515c50d8ae3SPaolo Bonzini } 1516c50d8ae3SPaolo Bonzini 1517c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1518c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1519c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1520c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1521c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1522c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1523c50d8ae3SPaolo Bonzini 15243039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1525c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15263039bcc7SSean Christopherson int level, pte_t pte); 1527c1b91493SSean Christopherson 15283039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15293039bcc7SSean Christopherson struct kvm_gfn_range *range, 1530c1b91493SSean Christopherson rmap_handler_t handler) 1531c50d8ae3SPaolo Bonzini { 1532c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15333039bcc7SSean Christopherson bool ret = false; 1534c50d8ae3SPaolo Bonzini 15353039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15363039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15373039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15383039bcc7SSean Christopherson iterator.level, range->pte); 1539c50d8ae3SPaolo Bonzini 1540c50d8ae3SPaolo Bonzini return ret; 1541c50d8ae3SPaolo Bonzini } 1542c50d8ae3SPaolo Bonzini 15433039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1544c50d8ae3SPaolo Bonzini { 1545e2209710SBen Gardon bool flush = false; 1546c50d8ae3SPaolo Bonzini 1547e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15483039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp); 1549063afacdSBen Gardon 1550897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1551c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1552063afacdSBen Gardon 15533039bcc7SSean Christopherson return flush; 1554c50d8ae3SPaolo Bonzini } 1555c50d8ae3SPaolo Bonzini 15563039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1557c50d8ae3SPaolo Bonzini { 1558e2209710SBen Gardon bool flush = false; 15591d8dd6b3SBen Gardon 1560e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15613039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp); 15621d8dd6b3SBen Gardon 1563897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15643039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15651d8dd6b3SBen Gardon 15663039bcc7SSean Christopherson return flush; 1567c50d8ae3SPaolo Bonzini } 1568c50d8ae3SPaolo Bonzini 15693039bcc7SSean Christopherson static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1570c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15713039bcc7SSean Christopherson pte_t unused) 1572c50d8ae3SPaolo Bonzini { 1573c50d8ae3SPaolo Bonzini u64 *sptep; 15743f649ab7SKees Cook struct rmap_iterator iter; 1575c50d8ae3SPaolo Bonzini int young = 0; 1576c50d8ae3SPaolo Bonzini 1577c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1578c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1579c50d8ae3SPaolo Bonzini 1580c50d8ae3SPaolo Bonzini return young; 1581c50d8ae3SPaolo Bonzini } 1582c50d8ae3SPaolo Bonzini 15833039bcc7SSean Christopherson static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1584c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15853039bcc7SSean Christopherson int level, pte_t unused) 1586c50d8ae3SPaolo Bonzini { 1587c50d8ae3SPaolo Bonzini u64 *sptep; 1588c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1589c50d8ae3SPaolo Bonzini 1590c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1591c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 159298a26b69SVihas Mak return true; 159398a26b69SVihas Mak return false; 1594c50d8ae3SPaolo Bonzini } 1595c50d8ae3SPaolo Bonzini 1596c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1597c50d8ae3SPaolo Bonzini 15988a9f566aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 15998a9f566aSDavid Matlack u64 *spte, gfn_t gfn) 1600c50d8ae3SPaolo Bonzini { 1601c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 160268be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 160368be1306SDavid Matlack int rmap_count; 1604c50d8ae3SPaolo Bonzini 160557354682SSean Christopherson sp = sptep_to_sp(spte); 160668be1306SDavid Matlack kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn); 160793e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 160868be1306SDavid Matlack rmap_count = pte_list_add(vcpu, spte, rmap_head); 1609c50d8ae3SPaolo Bonzini 161068be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16113039bcc7SSean Christopherson kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0)); 161268be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 161368be1306SDavid Matlack vcpu->kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 161468be1306SDavid Matlack } 1615c50d8ae3SPaolo Bonzini } 1616c50d8ae3SPaolo Bonzini 16173039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1618c50d8ae3SPaolo Bonzini { 1619e2209710SBen Gardon bool young = false; 1620f8e14497SBen Gardon 1621e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16223039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp); 16233039bcc7SSean Christopherson 1624897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16253039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1626f8e14497SBen Gardon 1627f8e14497SBen Gardon return young; 1628c50d8ae3SPaolo Bonzini } 1629c50d8ae3SPaolo Bonzini 16303039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1631c50d8ae3SPaolo Bonzini { 1632e2209710SBen Gardon bool young = false; 1633f8e14497SBen Gardon 1634e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16353039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp); 16363039bcc7SSean Christopherson 1637897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16383039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1639f8e14497SBen Gardon 1640f8e14497SBen Gardon return young; 1641c50d8ae3SPaolo Bonzini } 1642c50d8ae3SPaolo Bonzini 1643c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1644c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1645c50d8ae3SPaolo Bonzini { 1646c50d8ae3SPaolo Bonzini u64 *pos; 1647c50d8ae3SPaolo Bonzini u64 *end; 1648c50d8ae3SPaolo Bonzini 1649c50d8ae3SPaolo Bonzini for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) 1650c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1651c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1652c50d8ae3SPaolo Bonzini pos, *pos); 1653c50d8ae3SPaolo Bonzini return 0; 1654c50d8ae3SPaolo Bonzini } 1655c50d8ae3SPaolo Bonzini return 1; 1656c50d8ae3SPaolo Bonzini } 1657c50d8ae3SPaolo Bonzini #endif 1658c50d8ae3SPaolo Bonzini 1659c50d8ae3SPaolo Bonzini /* 1660c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1661c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1662c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1663c50d8ae3SPaolo Bonzini * faster 1664c50d8ae3SPaolo Bonzini */ 1665d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1666c50d8ae3SPaolo Bonzini { 1667c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1668c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1669c50d8ae3SPaolo Bonzini } 1670c50d8ae3SPaolo Bonzini 1671c50d8ae3SPaolo Bonzini static void kvm_mmu_free_page(struct kvm_mmu_page *sp) 1672c50d8ae3SPaolo Bonzini { 1673c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1674c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1675c50d8ae3SPaolo Bonzini list_del(&sp->link); 1676c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1677c50d8ae3SPaolo Bonzini if (!sp->role.direct) 1678c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->gfns); 1679c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1680c50d8ae3SPaolo Bonzini } 1681c50d8ae3SPaolo Bonzini 1682c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1683c50d8ae3SPaolo Bonzini { 1684c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1685c50d8ae3SPaolo Bonzini } 1686c50d8ae3SPaolo Bonzini 1687c50d8ae3SPaolo Bonzini static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, 1688c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1689c50d8ae3SPaolo Bonzini { 1690c50d8ae3SPaolo Bonzini if (!parent_pte) 1691c50d8ae3SPaolo Bonzini return; 1692c50d8ae3SPaolo Bonzini 1693c50d8ae3SPaolo Bonzini pte_list_add(vcpu, parent_pte, &sp->parent_ptes); 1694c50d8ae3SPaolo Bonzini } 1695c50d8ae3SPaolo Bonzini 1696c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1697c50d8ae3SPaolo Bonzini u64 *parent_pte) 1698c50d8ae3SPaolo Bonzini { 1699c50d8ae3SPaolo Bonzini __pte_list_remove(parent_pte, &sp->parent_ptes); 1700c50d8ae3SPaolo Bonzini } 1701c50d8ae3SPaolo Bonzini 1702c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1703c50d8ae3SPaolo Bonzini u64 *parent_pte) 1704c50d8ae3SPaolo Bonzini { 1705c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1706c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1707c50d8ae3SPaolo Bonzini } 1708c50d8ae3SPaolo Bonzini 1709c50d8ae3SPaolo Bonzini static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct) 1710c50d8ae3SPaolo Bonzini { 1711c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1712c50d8ae3SPaolo Bonzini 171394ce87efSSean Christopherson sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache); 171494ce87efSSean Christopherson sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache); 1715c50d8ae3SPaolo Bonzini if (!direct) 171694ce87efSSean Christopherson sp->gfns = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache); 1717c50d8ae3SPaolo Bonzini set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 1718c50d8ae3SPaolo Bonzini 1719c50d8ae3SPaolo Bonzini /* 1720c50d8ae3SPaolo Bonzini * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 1721c50d8ae3SPaolo Bonzini * depends on valid pages being added to the head of the list. See 1722c50d8ae3SPaolo Bonzini * comments in kvm_zap_obsolete_pages(). 1723c50d8ae3SPaolo Bonzini */ 1724c50d8ae3SPaolo Bonzini sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; 1725c50d8ae3SPaolo Bonzini list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); 1726c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(vcpu->kvm, +1); 1727c50d8ae3SPaolo Bonzini return sp; 1728c50d8ae3SPaolo Bonzini } 1729c50d8ae3SPaolo Bonzini 1730c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1731c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1732c50d8ae3SPaolo Bonzini { 1733c50d8ae3SPaolo Bonzini u64 *sptep; 1734c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1735c50d8ae3SPaolo Bonzini 1736c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1737c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1738c50d8ae3SPaolo Bonzini } 1739c50d8ae3SPaolo Bonzini } 1740c50d8ae3SPaolo Bonzini 1741c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1742c50d8ae3SPaolo Bonzini { 1743c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1744c50d8ae3SPaolo Bonzini unsigned int index; 1745c50d8ae3SPaolo Bonzini 174657354682SSean Christopherson sp = sptep_to_sp(spte); 1747c50d8ae3SPaolo Bonzini index = spte - sp->spt; 1748c50d8ae3SPaolo Bonzini if (__test_and_set_bit(index, sp->unsync_child_bitmap)) 1749c50d8ae3SPaolo Bonzini return; 1750c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1751c50d8ae3SPaolo Bonzini return; 1752c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1753c50d8ae3SPaolo Bonzini } 1754c50d8ae3SPaolo Bonzini 1755c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1756c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1757c50d8ae3SPaolo Bonzini { 1758c3e5e415SLai Jiangshan return -1; 1759c50d8ae3SPaolo Bonzini } 1760c50d8ae3SPaolo Bonzini 1761c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1762c50d8ae3SPaolo Bonzini 1763c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1764c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1765c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1766c50d8ae3SPaolo Bonzini unsigned int idx; 1767c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1768c50d8ae3SPaolo Bonzini unsigned int nr; 1769c50d8ae3SPaolo Bonzini }; 1770c50d8ae3SPaolo Bonzini 1771c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1772c50d8ae3SPaolo Bonzini int idx) 1773c50d8ae3SPaolo Bonzini { 1774c50d8ae3SPaolo Bonzini int i; 1775c50d8ae3SPaolo Bonzini 1776c50d8ae3SPaolo Bonzini if (sp->unsync) 1777c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1778c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1779c50d8ae3SPaolo Bonzini return 0; 1780c50d8ae3SPaolo Bonzini 1781c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1782c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1783c50d8ae3SPaolo Bonzini pvec->nr++; 1784c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1785c50d8ae3SPaolo Bonzini } 1786c50d8ae3SPaolo Bonzini 1787c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1788c50d8ae3SPaolo Bonzini { 1789c50d8ae3SPaolo Bonzini --sp->unsync_children; 1790c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1791c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1792c50d8ae3SPaolo Bonzini } 1793c50d8ae3SPaolo Bonzini 1794c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1795c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1796c50d8ae3SPaolo Bonzini { 1797c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1798c50d8ae3SPaolo Bonzini 1799c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1800c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1801c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1802c50d8ae3SPaolo Bonzini 1803c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1804c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1805c50d8ae3SPaolo Bonzini continue; 1806c50d8ae3SPaolo Bonzini } 1807c50d8ae3SPaolo Bonzini 1808e47c4aeeSSean Christopherson child = to_shadow_page(ent & PT64_BASE_ADDR_MASK); 1809c50d8ae3SPaolo Bonzini 1810c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1811c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1812c50d8ae3SPaolo Bonzini return -ENOSPC; 1813c50d8ae3SPaolo Bonzini 1814c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1815c50d8ae3SPaolo Bonzini if (!ret) { 1816c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1817c50d8ae3SPaolo Bonzini continue; 1818c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1819c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1820c50d8ae3SPaolo Bonzini } else 1821c50d8ae3SPaolo Bonzini return ret; 1822c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1823c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1824c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1825c50d8ae3SPaolo Bonzini return -ENOSPC; 1826c50d8ae3SPaolo Bonzini } else 1827c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1828c50d8ae3SPaolo Bonzini } 1829c50d8ae3SPaolo Bonzini 1830c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1831c50d8ae3SPaolo Bonzini } 1832c50d8ae3SPaolo Bonzini 1833c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1834c50d8ae3SPaolo Bonzini 1835c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1836c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1837c50d8ae3SPaolo Bonzini { 1838c50d8ae3SPaolo Bonzini pvec->nr = 0; 1839c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1840c50d8ae3SPaolo Bonzini return 0; 1841c50d8ae3SPaolo Bonzini 1842c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1843c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1844c50d8ae3SPaolo Bonzini } 1845c50d8ae3SPaolo Bonzini 1846c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1847c50d8ae3SPaolo Bonzini { 1848c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1849c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1850c50d8ae3SPaolo Bonzini sp->unsync = 0; 1851c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1852c50d8ae3SPaolo Bonzini } 1853c50d8ae3SPaolo Bonzini 1854c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1855c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1856c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1857c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1858c50d8ae3SPaolo Bonzini 1859ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1860ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1861c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1862c50d8ae3SPaolo Bonzini } else 1863c50d8ae3SPaolo Bonzini 1864c50d8ae3SPaolo Bonzini #define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn) \ 1865ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1866ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1867c50d8ae3SPaolo Bonzini if ((_sp)->gfn != (_gfn) || (_sp)->role.direct) {} else 1868c50d8ae3SPaolo Bonzini 18698d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1870c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1871c50d8ae3SPaolo Bonzini { 1872c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1873c3e5e415SLai Jiangshan 18748d5678a7SHou Wenlong if (ret < 0) 1875c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18768d5678a7SHou Wenlong return ret; 1877c50d8ae3SPaolo Bonzini } 1878c50d8ae3SPaolo Bonzini 1879c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1880c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1881c50d8ae3SPaolo Bonzini bool remote_flush) 1882c50d8ae3SPaolo Bonzini { 1883c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1884c50d8ae3SPaolo Bonzini return false; 1885c50d8ae3SPaolo Bonzini 1886c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1887c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1888c50d8ae3SPaolo Bonzini else 1889c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1890c50d8ae3SPaolo Bonzini return true; 1891c50d8ae3SPaolo Bonzini } 1892c50d8ae3SPaolo Bonzini 1893c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1894c50d8ae3SPaolo Bonzini { 1895a955cad8SSean Christopherson if (sp->role.invalid) 1896a955cad8SSean Christopherson return true; 1897a955cad8SSean Christopherson 1898a955cad8SSean Christopherson /* TDP MMU pages due not use the MMU generation. */ 1899a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1900c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1901c50d8ae3SPaolo Bonzini } 1902c50d8ae3SPaolo Bonzini 1903c50d8ae3SPaolo Bonzini struct mmu_page_path { 1904c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1905c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1906c50d8ae3SPaolo Bonzini }; 1907c50d8ae3SPaolo Bonzini 1908c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1909c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1910c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1911c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1912c50d8ae3SPaolo Bonzini 1913c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1914c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1915c50d8ae3SPaolo Bonzini int i) 1916c50d8ae3SPaolo Bonzini { 1917c50d8ae3SPaolo Bonzini int n; 1918c50d8ae3SPaolo Bonzini 1919c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1920c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1921c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1922c50d8ae3SPaolo Bonzini int level = sp->role.level; 1923c50d8ae3SPaolo Bonzini 1924c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19253bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1926c50d8ae3SPaolo Bonzini break; 1927c50d8ae3SPaolo Bonzini 1928c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1929c50d8ae3SPaolo Bonzini } 1930c50d8ae3SPaolo Bonzini 1931c50d8ae3SPaolo Bonzini return n; 1932c50d8ae3SPaolo Bonzini } 1933c50d8ae3SPaolo Bonzini 1934c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1935c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1936c50d8ae3SPaolo Bonzini { 1937c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1938c50d8ae3SPaolo Bonzini int level; 1939c50d8ae3SPaolo Bonzini 1940c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1941c50d8ae3SPaolo Bonzini return 0; 1942c50d8ae3SPaolo Bonzini 1943c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1944c50d8ae3SPaolo Bonzini 1945c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1946c50d8ae3SPaolo Bonzini level = sp->role.level; 19473bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1948c50d8ae3SPaolo Bonzini 1949c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1950c50d8ae3SPaolo Bonzini 1951c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1952c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1953c50d8ae3SPaolo Bonzini */ 1954c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1955c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1956c50d8ae3SPaolo Bonzini } 1957c50d8ae3SPaolo Bonzini 1958c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1959c50d8ae3SPaolo Bonzini { 1960c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1961c50d8ae3SPaolo Bonzini unsigned int level = 0; 1962c50d8ae3SPaolo Bonzini 1963c50d8ae3SPaolo Bonzini do { 1964c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1965c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1966c50d8ae3SPaolo Bonzini if (!sp) 1967c50d8ae3SPaolo Bonzini return; 1968c50d8ae3SPaolo Bonzini 1969c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1970c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1971c50d8ae3SPaolo Bonzini level++; 1972c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1973c50d8ae3SPaolo Bonzini } 1974c50d8ae3SPaolo Bonzini 197565855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 197665855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1977c50d8ae3SPaolo Bonzini { 1978c50d8ae3SPaolo Bonzini int i; 1979c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1980c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1981c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1982c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1983c50d8ae3SPaolo Bonzini bool flush = false; 1984c50d8ae3SPaolo Bonzini 1985c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 1986c50d8ae3SPaolo Bonzini bool protected = false; 1987c50d8ae3SPaolo Bonzini 1988c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 1989cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 1990c50d8ae3SPaolo Bonzini 1991c50d8ae3SPaolo Bonzini if (protected) { 19925591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 1993c50d8ae3SPaolo Bonzini flush = false; 1994c50d8ae3SPaolo Bonzini } 1995c50d8ae3SPaolo Bonzini 1996c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 1997479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 19988d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 1999c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2000c50d8ae3SPaolo Bonzini } 2001531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2002c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 200365855ed8SLai Jiangshan if (!can_yield) { 200465855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 200565855ed8SLai Jiangshan return -EINTR; 200665855ed8SLai Jiangshan } 200765855ed8SLai Jiangshan 2008531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2009c50d8ae3SPaolo Bonzini flush = false; 2010c50d8ae3SPaolo Bonzini } 2011c50d8ae3SPaolo Bonzini } 2012c50d8ae3SPaolo Bonzini 2013c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 201465855ed8SLai Jiangshan return 0; 2015c50d8ae3SPaolo Bonzini } 2016c50d8ae3SPaolo Bonzini 2017c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2018c50d8ae3SPaolo Bonzini { 2019c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2020c50d8ae3SPaolo Bonzini } 2021c50d8ae3SPaolo Bonzini 2022c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2023c50d8ae3SPaolo Bonzini { 202457354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2025c50d8ae3SPaolo Bonzini } 2026c50d8ae3SPaolo Bonzini 2027c50d8ae3SPaolo Bonzini static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, 2028c50d8ae3SPaolo Bonzini gfn_t gfn, 2029c50d8ae3SPaolo Bonzini gva_t gaddr, 2030c50d8ae3SPaolo Bonzini unsigned level, 2031c50d8ae3SPaolo Bonzini int direct, 20320a2b64c5SBen Gardon unsigned int access) 2033c50d8ae3SPaolo Bonzini { 2034fb58a9c3SSean Christopherson bool direct_mmu = vcpu->arch.mmu->direct_map; 2035c50d8ae3SPaolo Bonzini union kvm_mmu_page_role role; 2036ac101b7cSSean Christopherson struct hlist_head *sp_list; 2037c50d8ae3SPaolo Bonzini unsigned quadrant; 2038c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20398d5678a7SHou Wenlong int ret; 2040c50d8ae3SPaolo Bonzini int collisions = 0; 2041c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2042c50d8ae3SPaolo Bonzini 2043c50d8ae3SPaolo Bonzini role = vcpu->arch.mmu->mmu_role.base; 2044c50d8ae3SPaolo Bonzini role.level = level; 2045c50d8ae3SPaolo Bonzini role.direct = direct; 2046c50d8ae3SPaolo Bonzini role.access = access; 2047bb3b394dSLai Jiangshan if (role.has_4_byte_gpte) { 2048c50d8ae3SPaolo Bonzini quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level)); 2049c50d8ae3SPaolo Bonzini quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; 2050c50d8ae3SPaolo Bonzini role.quadrant = quadrant; 2051c50d8ae3SPaolo Bonzini } 2052ac101b7cSSean Christopherson 2053ac101b7cSSean Christopherson sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 2054ac101b7cSSean Christopherson for_each_valid_sp(vcpu->kvm, sp, sp_list) { 2055c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2056c50d8ae3SPaolo Bonzini collisions++; 2057c50d8ae3SPaolo Bonzini continue; 2058c50d8ae3SPaolo Bonzini } 2059c50d8ae3SPaolo Bonzini 2060ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2061ddc16abbSSean Christopherson /* 2062ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2063ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2064ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2065ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2066ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2067ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2068ddc16abbSSean Christopherson * upper-level page will be write-protected. 2069ddc16abbSSean Christopherson */ 2070ddc16abbSSean Christopherson if (level > PG_LEVEL_4K && sp->unsync) 2071ddc16abbSSean Christopherson kvm_mmu_prepare_zap_page(vcpu->kvm, sp, 2072ddc16abbSSean Christopherson &invalid_list); 2073c50d8ae3SPaolo Bonzini continue; 2074ddc16abbSSean Christopherson } 2075c50d8ae3SPaolo Bonzini 2076fb58a9c3SSean Christopherson if (direct_mmu) 2077fb58a9c3SSean Christopherson goto trace_get_page; 2078fb58a9c3SSean Christopherson 2079c50d8ae3SPaolo Bonzini if (sp->unsync) { 208007dc4f35SSean Christopherson /* 2081479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 208207dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 208307dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 208407dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 208507dc4f35SSean Christopherson * overhead of write protection is not incurred until the 208607dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 208707dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 208807dc4f35SSean Christopherson * 208907dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 209007dc4f35SSean Christopherson * in order to rebuild it. 2091c50d8ae3SPaolo Bonzini */ 20928d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 20938d5678a7SHou Wenlong if (ret < 0) 2094c50d8ae3SPaolo Bonzini break; 2095c50d8ae3SPaolo Bonzini 2096c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 20978d5678a7SHou Wenlong if (ret > 0) 2098c3e5e415SLai Jiangshan kvm_flush_remote_tlbs(vcpu->kvm); 2099c50d8ae3SPaolo Bonzini } 2100c50d8ae3SPaolo Bonzini 2101c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2102fb58a9c3SSean Christopherson 2103fb58a9c3SSean Christopherson trace_get_page: 2104c50d8ae3SPaolo Bonzini trace_kvm_mmu_get_page(sp, false); 2105c50d8ae3SPaolo Bonzini goto out; 2106c50d8ae3SPaolo Bonzini } 2107c50d8ae3SPaolo Bonzini 2108c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_cache_miss; 2109c50d8ae3SPaolo Bonzini 2110c50d8ae3SPaolo Bonzini sp = kvm_mmu_alloc_page(vcpu, direct); 2111c50d8ae3SPaolo Bonzini 2112c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2113c50d8ae3SPaolo Bonzini sp->role = role; 2114ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2115c50d8ae3SPaolo Bonzini if (!direct) { 2116c50d8ae3SPaolo Bonzini account_shadowed(vcpu->kvm, sp); 2117cf48f9e2SDavid Matlack if (level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn)) 2118c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1); 2119c50d8ae3SPaolo Bonzini } 2120c50d8ae3SPaolo Bonzini trace_kvm_mmu_get_page(sp, true); 2121c50d8ae3SPaolo Bonzini out: 2122ddc16abbSSean Christopherson kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); 2123ddc16abbSSean Christopherson 2124c50d8ae3SPaolo Bonzini if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions) 2125c50d8ae3SPaolo Bonzini vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions; 2126c50d8ae3SPaolo Bonzini return sp; 2127c50d8ae3SPaolo Bonzini } 2128c50d8ae3SPaolo Bonzini 2129c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2130c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2131c50d8ae3SPaolo Bonzini u64 addr) 2132c50d8ae3SPaolo Bonzini { 2133c50d8ae3SPaolo Bonzini iterator->addr = addr; 2134c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2135c50d8ae3SPaolo Bonzini iterator->level = vcpu->arch.mmu->shadow_root_level; 2136c50d8ae3SPaolo Bonzini 213712ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 2138c50d8ae3SPaolo Bonzini vcpu->arch.mmu->root_level < PT64_ROOT_4LEVEL && 2139c50d8ae3SPaolo Bonzini !vcpu->arch.mmu->direct_map) 214012ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2141c50d8ae3SPaolo Bonzini 2142c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2143c50d8ae3SPaolo Bonzini /* 2144c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2145c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2146c50d8ae3SPaolo Bonzini */ 2147b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2148c50d8ae3SPaolo Bonzini 2149c50d8ae3SPaolo Bonzini iterator->shadow_addr 2150c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 2151c50d8ae3SPaolo Bonzini iterator->shadow_addr &= PT64_BASE_ADDR_MASK; 2152c50d8ae3SPaolo Bonzini --iterator->level; 2153c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2154c50d8ae3SPaolo Bonzini iterator->level = 0; 2155c50d8ae3SPaolo Bonzini } 2156c50d8ae3SPaolo Bonzini } 2157c50d8ae3SPaolo Bonzini 2158c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2159c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2160c50d8ae3SPaolo Bonzini { 2161b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2162c50d8ae3SPaolo Bonzini addr); 2163c50d8ae3SPaolo Bonzini } 2164c50d8ae3SPaolo Bonzini 2165c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2166c50d8ae3SPaolo Bonzini { 21673bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2168c50d8ae3SPaolo Bonzini return false; 2169c50d8ae3SPaolo Bonzini 2170c50d8ae3SPaolo Bonzini iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level); 2171c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2172c50d8ae3SPaolo Bonzini return true; 2173c50d8ae3SPaolo Bonzini } 2174c50d8ae3SPaolo Bonzini 2175c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2176c50d8ae3SPaolo Bonzini u64 spte) 2177c50d8ae3SPaolo Bonzini { 21783e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2179c50d8ae3SPaolo Bonzini iterator->level = 0; 2180c50d8ae3SPaolo Bonzini return; 2181c50d8ae3SPaolo Bonzini } 2182c50d8ae3SPaolo Bonzini 2183c50d8ae3SPaolo Bonzini iterator->shadow_addr = spte & PT64_BASE_ADDR_MASK; 2184c50d8ae3SPaolo Bonzini --iterator->level; 2185c50d8ae3SPaolo Bonzini } 2186c50d8ae3SPaolo Bonzini 2187c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2188c50d8ae3SPaolo Bonzini { 2189c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2190c50d8ae3SPaolo Bonzini } 2191c50d8ae3SPaolo Bonzini 2192c50d8ae3SPaolo Bonzini static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 2193c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 2194c50d8ae3SPaolo Bonzini { 2195c50d8ae3SPaolo Bonzini u64 spte; 2196c50d8ae3SPaolo Bonzini 2197c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2198c50d8ae3SPaolo Bonzini 2199cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2200c50d8ae3SPaolo Bonzini 2201c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2202c50d8ae3SPaolo Bonzini 2203c50d8ae3SPaolo Bonzini mmu_page_add_parent_pte(vcpu, sp, sptep); 2204c50d8ae3SPaolo Bonzini 2205c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2206c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2207c50d8ae3SPaolo Bonzini } 2208c50d8ae3SPaolo Bonzini 2209c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2210c50d8ae3SPaolo Bonzini unsigned direct_access) 2211c50d8ae3SPaolo Bonzini { 2212c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2213c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2214c50d8ae3SPaolo Bonzini 2215c50d8ae3SPaolo Bonzini /* 2216c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2217c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2218c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2219c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2220c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2221c50d8ae3SPaolo Bonzini */ 2222e47c4aeeSSean Christopherson child = to_shadow_page(*sptep & PT64_BASE_ADDR_MASK); 2223c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2224c50d8ae3SPaolo Bonzini return; 2225c50d8ae3SPaolo Bonzini 2226c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2227c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2228c50d8ae3SPaolo Bonzini } 2229c50d8ae3SPaolo Bonzini } 2230c50d8ae3SPaolo Bonzini 22312de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 22322de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 22332de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2234c50d8ae3SPaolo Bonzini { 2235c50d8ae3SPaolo Bonzini u64 pte; 2236c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2237c50d8ae3SPaolo Bonzini 2238c50d8ae3SPaolo Bonzini pte = *spte; 2239c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2240c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2241c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2242c50d8ae3SPaolo Bonzini } else { 2243e47c4aeeSSean Christopherson child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); 2244c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 22452de4085cSBen Gardon 22462de4085cSBen Gardon /* 22472de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 22482de4085cSBen Gardon * unlikely to be used again in the near future. This 22492de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 22502de4085cSBen Gardon */ 22512de4085cSBen Gardon if (tdp_enabled && invalid_list && 22522de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 22532de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 22542de4085cSBen Gardon invalid_list); 2255c50d8ae3SPaolo Bonzini } 2256ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2257c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2258ace569e0SSean Christopherson } 22592de4085cSBen Gardon return 0; 2260c50d8ae3SPaolo Bonzini } 2261c50d8ae3SPaolo Bonzini 22622de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 22632de4085cSBen Gardon struct kvm_mmu_page *sp, 22642de4085cSBen Gardon struct list_head *invalid_list) 2265c50d8ae3SPaolo Bonzini { 22662de4085cSBen Gardon int zapped = 0; 2267c50d8ae3SPaolo Bonzini unsigned i; 2268c50d8ae3SPaolo Bonzini 2269c50d8ae3SPaolo Bonzini for (i = 0; i < PT64_ENT_PER_PAGE; ++i) 22702de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 22712de4085cSBen Gardon 22722de4085cSBen Gardon return zapped; 2273c50d8ae3SPaolo Bonzini } 2274c50d8ae3SPaolo Bonzini 227561827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2276c50d8ae3SPaolo Bonzini { 2277c50d8ae3SPaolo Bonzini u64 *sptep; 2278c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2279c50d8ae3SPaolo Bonzini 2280c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2281c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2282c50d8ae3SPaolo Bonzini } 2283c50d8ae3SPaolo Bonzini 2284c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2285c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2286c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2287c50d8ae3SPaolo Bonzini { 2288c50d8ae3SPaolo Bonzini int i, zapped = 0; 2289c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2290c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2291c50d8ae3SPaolo Bonzini 22923bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2293c50d8ae3SPaolo Bonzini return 0; 2294c50d8ae3SPaolo Bonzini 2295c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2296c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2297c50d8ae3SPaolo Bonzini 2298c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2299c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2300c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2301c50d8ae3SPaolo Bonzini zapped++; 2302c50d8ae3SPaolo Bonzini } 2303c50d8ae3SPaolo Bonzini } 2304c50d8ae3SPaolo Bonzini 2305c50d8ae3SPaolo Bonzini return zapped; 2306c50d8ae3SPaolo Bonzini } 2307c50d8ae3SPaolo Bonzini 2308c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2309c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2310c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2311c50d8ae3SPaolo Bonzini int *nr_zapped) 2312c50d8ae3SPaolo Bonzini { 2313527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2314c50d8ae3SPaolo Bonzini 2315c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2316c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2317c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 23182de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 231961827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2320c50d8ae3SPaolo Bonzini 2321c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2322c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2323c50d8ae3SPaolo Bonzini 2324c50d8ae3SPaolo Bonzini if (!sp->role.invalid && !sp->role.direct) 2325c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2326c50d8ae3SPaolo Bonzini 2327c50d8ae3SPaolo Bonzini if (sp->unsync) 2328c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2329c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2330c50d8ae3SPaolo Bonzini /* Count self */ 2331c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2332f95eec9bSSean Christopherson 2333f95eec9bSSean Christopherson /* 2334f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2335f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2336f95eec9bSSean Christopherson * !sp->root_count. 2337f95eec9bSSean Christopherson */ 2338f95eec9bSSean Christopherson if (sp->role.invalid) 2339f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2340f95eec9bSSean Christopherson else 2341c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 2342c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(kvm, -1); 2343c50d8ae3SPaolo Bonzini } else { 2344f95eec9bSSean Christopherson /* 2345f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2346f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2347f95eec9bSSean Christopherson */ 2348f95eec9bSSean Christopherson list_del(&sp->link); 2349c50d8ae3SPaolo Bonzini 2350c50d8ae3SPaolo Bonzini /* 2351c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2352c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2353c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2354c50d8ae3SPaolo Bonzini */ 2355527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2356c50d8ae3SPaolo Bonzini } 2357c50d8ae3SPaolo Bonzini 2358c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2359c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2360c50d8ae3SPaolo Bonzini 2361c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2362527d5cd7SSean Christopherson 2363527d5cd7SSean Christopherson /* 2364527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2365527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2366527d5cd7SSean Christopherson */ 2367527d5cd7SSean Christopherson if (zapped_root) 2368527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2369c50d8ae3SPaolo Bonzini return list_unstable; 2370c50d8ae3SPaolo Bonzini } 2371c50d8ae3SPaolo Bonzini 2372c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2373c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2374c50d8ae3SPaolo Bonzini { 2375c50d8ae3SPaolo Bonzini int nr_zapped; 2376c50d8ae3SPaolo Bonzini 2377c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2378c50d8ae3SPaolo Bonzini return nr_zapped; 2379c50d8ae3SPaolo Bonzini } 2380c50d8ae3SPaolo Bonzini 2381c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2382c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2383c50d8ae3SPaolo Bonzini { 2384c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2385c50d8ae3SPaolo Bonzini 2386c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2387c50d8ae3SPaolo Bonzini return; 2388c50d8ae3SPaolo Bonzini 2389c50d8ae3SPaolo Bonzini /* 2390c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2391c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2392c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2393c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2394c50d8ae3SPaolo Bonzini * 2395c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2396c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2397c50d8ae3SPaolo Bonzini */ 2398c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2399c50d8ae3SPaolo Bonzini 2400c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2401c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 2402c50d8ae3SPaolo Bonzini kvm_mmu_free_page(sp); 2403c50d8ae3SPaolo Bonzini } 2404c50d8ae3SPaolo Bonzini } 2405c50d8ae3SPaolo Bonzini 24066b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 24076b82ef2cSSean Christopherson unsigned long nr_to_zap) 2408c50d8ae3SPaolo Bonzini { 24096b82ef2cSSean Christopherson unsigned long total_zapped = 0; 24106b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2411ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 24126b82ef2cSSean Christopherson bool unstable; 24136b82ef2cSSean Christopherson int nr_zapped; 2414c50d8ae3SPaolo Bonzini 2415c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2416ba7888ddSSean Christopherson return 0; 2417c50d8ae3SPaolo Bonzini 24186b82ef2cSSean Christopherson restart: 24198fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 24206b82ef2cSSean Christopherson /* 24216b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 24226b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 24236b82ef2cSSean Christopherson */ 24246b82ef2cSSean Christopherson if (sp->root_count) 24256b82ef2cSSean Christopherson continue; 24266b82ef2cSSean Christopherson 24276b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 24286b82ef2cSSean Christopherson &nr_zapped); 24296b82ef2cSSean Christopherson total_zapped += nr_zapped; 24306b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2431ba7888ddSSean Christopherson break; 2432ba7888ddSSean Christopherson 24336b82ef2cSSean Christopherson if (unstable) 24346b82ef2cSSean Christopherson goto restart; 2435ba7888ddSSean Christopherson } 24366b82ef2cSSean Christopherson 24376b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 24386b82ef2cSSean Christopherson 24396b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 24406b82ef2cSSean Christopherson return total_zapped; 24416b82ef2cSSean Christopherson } 24426b82ef2cSSean Christopherson 2443afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2444afe8d7e6SSean Christopherson { 2445afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2446afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2447afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2448afe8d7e6SSean Christopherson 2449afe8d7e6SSean Christopherson return 0; 2450c50d8ae3SPaolo Bonzini } 2451c50d8ae3SPaolo Bonzini 2452ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2453ba7888ddSSean Christopherson { 24546b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2455ba7888ddSSean Christopherson 24566b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2457ba7888ddSSean Christopherson return 0; 2458ba7888ddSSean Christopherson 24596b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2460ba7888ddSSean Christopherson 24616e6ec584SSean Christopherson /* 24626e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 24636e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 24646e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 24656e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2466c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 24676e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 24686e6ec584SSean Christopherson * page fault paths. 24696e6ec584SSean Christopherson */ 2470ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2471ba7888ddSSean Christopherson return -ENOSPC; 2472ba7888ddSSean Christopherson return 0; 2473ba7888ddSSean Christopherson } 2474ba7888ddSSean Christopherson 2475c50d8ae3SPaolo Bonzini /* 2476c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2477c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2478c50d8ae3SPaolo Bonzini */ 2479c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2480c50d8ae3SPaolo Bonzini { 2481531810caSBen Gardon write_lock(&kvm->mmu_lock); 2482c50d8ae3SPaolo Bonzini 2483c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 24846b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 24856b82ef2cSSean Christopherson goal_nr_mmu_pages); 2486c50d8ae3SPaolo Bonzini 2487c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2488c50d8ae3SPaolo Bonzini } 2489c50d8ae3SPaolo Bonzini 2490c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2491c50d8ae3SPaolo Bonzini 2492531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2493c50d8ae3SPaolo Bonzini } 2494c50d8ae3SPaolo Bonzini 2495c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2496c50d8ae3SPaolo Bonzini { 2497c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2498c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2499c50d8ae3SPaolo Bonzini int r; 2500c50d8ae3SPaolo Bonzini 2501c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2502c50d8ae3SPaolo Bonzini r = 0; 2503531810caSBen Gardon write_lock(&kvm->mmu_lock); 2504c50d8ae3SPaolo Bonzini for_each_gfn_indirect_valid_sp(kvm, sp, gfn) { 2505c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2506c50d8ae3SPaolo Bonzini sp->role.word); 2507c50d8ae3SPaolo Bonzini r = 1; 2508c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2509c50d8ae3SPaolo Bonzini } 2510c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2511531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2512c50d8ae3SPaolo Bonzini 2513c50d8ae3SPaolo Bonzini return r; 2514c50d8ae3SPaolo Bonzini } 251596ad91aeSSean Christopherson 251696ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 251796ad91aeSSean Christopherson { 251896ad91aeSSean Christopherson gpa_t gpa; 251996ad91aeSSean Christopherson int r; 252096ad91aeSSean Christopherson 252196ad91aeSSean Christopherson if (vcpu->arch.mmu->direct_map) 252296ad91aeSSean Christopherson return 0; 252396ad91aeSSean Christopherson 252496ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 252596ad91aeSSean Christopherson 252696ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 252796ad91aeSSean Christopherson 252896ad91aeSSean Christopherson return r; 252996ad91aeSSean Christopherson } 2530c50d8ae3SPaolo Bonzini 25314d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2532c50d8ae3SPaolo Bonzini { 2533c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 25344d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2535c50d8ae3SPaolo Bonzini sp->unsync = 1; 2536c50d8ae3SPaolo Bonzini 2537c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2538c50d8ae3SPaolo Bonzini } 2539c50d8ae3SPaolo Bonzini 25400337f585SSean Christopherson /* 25410337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 25420337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 25430337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 25440337f585SSean Christopherson * be write-protected. 25450337f585SSean Christopherson */ 25468283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 25472839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2548c50d8ae3SPaolo Bonzini { 2549c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2550ce25681dSSean Christopherson bool locked = false; 2551c50d8ae3SPaolo Bonzini 25520337f585SSean Christopherson /* 25530337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 25540337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 25550337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 25560337f585SSean Christopherson */ 25574d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 25580337f585SSean Christopherson return -EPERM; 2559c50d8ae3SPaolo Bonzini 25600337f585SSean Christopherson /* 25610337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 25620337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 25630337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 25640337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 25650337f585SSean Christopherson */ 25664d78d0b3SBen Gardon for_each_gfn_indirect_valid_sp(kvm, sp, gfn) { 2567c50d8ae3SPaolo Bonzini if (!can_unsync) 25680337f585SSean Christopherson return -EPERM; 2569c50d8ae3SPaolo Bonzini 2570c50d8ae3SPaolo Bonzini if (sp->unsync) 2571c50d8ae3SPaolo Bonzini continue; 2572c50d8ae3SPaolo Bonzini 25732839180cSPaolo Bonzini if (prefetch) 2574f1c4a88cSLai Jiangshan return -EEXIST; 2575f1c4a88cSLai Jiangshan 2576ce25681dSSean Christopherson /* 2577ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2578ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2579ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2580ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2581ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2582ce25681dSSean Christopherson */ 2583ce25681dSSean Christopherson if (!locked) { 2584ce25681dSSean Christopherson locked = true; 25854d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2586ce25681dSSean Christopherson 2587ce25681dSSean Christopherson /* 2588ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2589ce25681dSSean Christopherson * may have since marked the page unsync. A false 2590ce25681dSSean Christopherson * positive on the unprotected check above is not 2591ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2592ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2593ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2594ce25681dSSean Christopherson */ 2595ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2596ce25681dSSean Christopherson continue; 2597ce25681dSSean Christopherson } 2598ce25681dSSean Christopherson 25993bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 26004d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2601c50d8ae3SPaolo Bonzini } 2602ce25681dSSean Christopherson if (locked) 26034d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2604c50d8ae3SPaolo Bonzini 2605c50d8ae3SPaolo Bonzini /* 2606c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2607c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2608c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2609c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2610c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2611c50d8ae3SPaolo Bonzini * following could happen: 2612c50d8ae3SPaolo Bonzini * 2613c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2614c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2615c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2616c50d8ae3SPaolo Bonzini * to be writable 2617c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2618c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2619c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2620c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2621c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2622c50d8ae3SPaolo Bonzini * fault. 2623c50d8ae3SPaolo Bonzini * 2624c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2625c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2626c50d8ae3SPaolo Bonzini * 26270337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 26280337f585SSean Christopherson * false and skips the page. 2629c50d8ae3SPaolo Bonzini * 2630c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2631c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2632c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2633c50d8ae3SPaolo Bonzini * gets used. 2634c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2635c50d8ae3SPaolo Bonzini * as unsync 2636c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2637c50d8ae3SPaolo Bonzini * 2638c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2639264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2640264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2641c50d8ae3SPaolo Bonzini */ 2642c50d8ae3SPaolo Bonzini smp_wmb(); 2643c50d8ae3SPaolo Bonzini 26440337f585SSean Christopherson return 0; 2645c50d8ae3SPaolo Bonzini } 2646c50d8ae3SPaolo Bonzini 26478a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 26488a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2649a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2650799a4190SBen Gardon { 2651d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2652eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2653c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2654c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2655c50d8ae3SPaolo Bonzini bool flush = false; 2656ad67e480SPaolo Bonzini bool wrprot; 2657d786c778SPaolo Bonzini u64 spte; 2658c50d8ae3SPaolo Bonzini 2659a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2660a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 26612839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2662a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2663c50d8ae3SPaolo Bonzini 2664c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2665c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2666c50d8ae3SPaolo Bonzini 2667a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 2668a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2669a54aa15cSSean Christopherson return RET_PF_EMULATE; 2670a54aa15cSSean Christopherson } 2671a54aa15cSSean Christopherson 2672c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2673c50d8ae3SPaolo Bonzini /* 2674c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2675c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2676c50d8ae3SPaolo Bonzini */ 26773bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2678c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2679c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2680c50d8ae3SPaolo Bonzini 2681e47c4aeeSSean Christopherson child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); 2682c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2683c50d8ae3SPaolo Bonzini flush = true; 2684c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2685c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2686c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2687c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2688c50d8ae3SPaolo Bonzini flush = true; 2689c50d8ae3SPaolo Bonzini } else 2690c50d8ae3SPaolo Bonzini was_rmapped = 1; 2691c50d8ae3SPaolo Bonzini } 2692c50d8ae3SPaolo Bonzini 26932839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 26947158bee4SPaolo Bonzini true, host_writable, &spte); 2695d786c778SPaolo Bonzini 2696d786c778SPaolo Bonzini if (*sptep == spte) { 2697d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2698d786c778SPaolo Bonzini } else { 2699d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 27005959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2701c50d8ae3SPaolo Bonzini } 2702c50d8ae3SPaolo Bonzini 2703ad67e480SPaolo Bonzini if (wrprot) { 2704c50d8ae3SPaolo Bonzini if (write_fault) 2705c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2706c50d8ae3SPaolo Bonzini } 2707c50d8ae3SPaolo Bonzini 2708d786c778SPaolo Bonzini if (flush) 2709c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2710c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2711c50d8ae3SPaolo Bonzini 2712c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2713c50d8ae3SPaolo Bonzini 2714c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2715d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 271671f51d2cSMingwei Zhang kvm_update_page_stats(vcpu->kvm, level, 1); 27178a9f566aSDavid Matlack rmap_add(vcpu, slot, sptep, gfn); 2718c50d8ae3SPaolo Bonzini } 2719c50d8ae3SPaolo Bonzini 2720c50d8ae3SPaolo Bonzini return ret; 2721c50d8ae3SPaolo Bonzini } 2722c50d8ae3SPaolo Bonzini 2723c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2724c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2725c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2726c50d8ae3SPaolo Bonzini { 2727c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2728c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 27290a2b64c5SBen Gardon unsigned int access = sp->role.access; 2730c50d8ae3SPaolo Bonzini int i, ret; 2731c50d8ae3SPaolo Bonzini gfn_t gfn; 2732c50d8ae3SPaolo Bonzini 2733c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt); 2734c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2735c50d8ae3SPaolo Bonzini if (!slot) 2736c50d8ae3SPaolo Bonzini return -1; 2737c50d8ae3SPaolo Bonzini 2738c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2739c50d8ae3SPaolo Bonzini if (ret <= 0) 2740c50d8ae3SPaolo Bonzini return -1; 2741c50d8ae3SPaolo Bonzini 2742c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 27438a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2744a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2745c50d8ae3SPaolo Bonzini put_page(pages[i]); 2746c50d8ae3SPaolo Bonzini } 2747c50d8ae3SPaolo Bonzini 2748c50d8ae3SPaolo Bonzini return 0; 2749c50d8ae3SPaolo Bonzini } 2750c50d8ae3SPaolo Bonzini 2751c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2752c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2753c50d8ae3SPaolo Bonzini { 2754c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2755c50d8ae3SPaolo Bonzini int i; 2756c50d8ae3SPaolo Bonzini 2757c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2758c50d8ae3SPaolo Bonzini 2759c50d8ae3SPaolo Bonzini i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); 2760c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2761c50d8ae3SPaolo Bonzini 2762c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2763c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2764c50d8ae3SPaolo Bonzini if (!start) 2765c50d8ae3SPaolo Bonzini continue; 2766c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2767c6cecc4bSSean Christopherson return; 2768c50d8ae3SPaolo Bonzini start = NULL; 2769c50d8ae3SPaolo Bonzini } else if (!start) 2770c50d8ae3SPaolo Bonzini start = spte; 2771c50d8ae3SPaolo Bonzini } 2772c6cecc4bSSean Christopherson if (start) 2773c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2774c50d8ae3SPaolo Bonzini } 2775c50d8ae3SPaolo Bonzini 2776c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2777c50d8ae3SPaolo Bonzini { 2778c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2779c50d8ae3SPaolo Bonzini 278057354682SSean Christopherson sp = sptep_to_sp(sptep); 2781c50d8ae3SPaolo Bonzini 2782c50d8ae3SPaolo Bonzini /* 2783c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2784c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2785c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2786c50d8ae3SPaolo Bonzini */ 2787c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2788c50d8ae3SPaolo Bonzini return; 2789c50d8ae3SPaolo Bonzini 27903bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2791c50d8ae3SPaolo Bonzini return; 2792c50d8ae3SPaolo Bonzini 27934a42d848SDavid Stevens /* 27944a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 27954a42d848SDavid Stevens * accidentally prefetching those addresses. 27964a42d848SDavid Stevens */ 27974a42d848SDavid Stevens if (unlikely(vcpu->kvm->mmu_notifier_count)) 27984a42d848SDavid Stevens return; 27994a42d848SDavid Stevens 2800c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2801c50d8ae3SPaolo Bonzini } 2802c50d8ae3SPaolo Bonzini 28031b6d9d9eSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, 28048ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2805db543216SSean Christopherson { 2806db543216SSean Christopherson unsigned long hva; 280744187235SMingwei Zhang unsigned long flags; 280844187235SMingwei Zhang int level = PG_LEVEL_4K; 280944187235SMingwei Zhang pgd_t pgd; 281044187235SMingwei Zhang p4d_t p4d; 281144187235SMingwei Zhang pud_t pud; 281244187235SMingwei Zhang pmd_t pmd; 2813db543216SSean Christopherson 2814e851265aSSean Christopherson if (!PageCompound(pfn_to_page(pfn)) && !kvm_is_zone_device_pfn(pfn)) 28153bae0459SSean Christopherson return PG_LEVEL_4K; 2816db543216SSean Christopherson 2817293e306eSSean Christopherson /* 2818293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2819293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2820293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2821293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2822293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2823293e306eSSean Christopherson * read-only memslot. 2824293e306eSSean Christopherson */ 2825db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2826db543216SSean Christopherson 282744187235SMingwei Zhang /* 282844187235SMingwei Zhang * Lookup the mapping level in the current mm. The information 282944187235SMingwei Zhang * may become stale soon, but it is safe to use as long as 283044187235SMingwei Zhang * 1) mmu_notifier_retry was checked after taking mmu_lock, and 283144187235SMingwei Zhang * 2) mmu_lock is taken now. 283244187235SMingwei Zhang * 283344187235SMingwei Zhang * We still need to disable IRQs to prevent concurrent tear down 283444187235SMingwei Zhang * of page tables. 283544187235SMingwei Zhang */ 283644187235SMingwei Zhang local_irq_save(flags); 2837db543216SSean Christopherson 283844187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 283944187235SMingwei Zhang if (pgd_none(pgd)) 284044187235SMingwei Zhang goto out; 284144187235SMingwei Zhang 284244187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 284344187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 284444187235SMingwei Zhang goto out; 284544187235SMingwei Zhang 284644187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 284744187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 284844187235SMingwei Zhang goto out; 284944187235SMingwei Zhang 285044187235SMingwei Zhang if (pud_large(pud)) { 285144187235SMingwei Zhang level = PG_LEVEL_1G; 285244187235SMingwei Zhang goto out; 285344187235SMingwei Zhang } 285444187235SMingwei Zhang 285544187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 285644187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 285744187235SMingwei Zhang goto out; 285844187235SMingwei Zhang 285944187235SMingwei Zhang if (pmd_large(pmd)) 286044187235SMingwei Zhang level = PG_LEVEL_2M; 286144187235SMingwei Zhang 286244187235SMingwei Zhang out: 286344187235SMingwei Zhang local_irq_restore(flags); 2864db543216SSean Christopherson return level; 2865db543216SSean Christopherson } 2866db543216SSean Christopherson 28678ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 28688ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 28698ca6f063SBen Gardon kvm_pfn_t pfn, int max_level) 28701b6d9d9eSSean Christopherson { 28711b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 2872ec607a56SPaolo Bonzini int host_level; 28731b6d9d9eSSean Christopherson 28741b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 28751b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 28761b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 28771b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 28781b6d9d9eSSean Christopherson break; 28791b6d9d9eSSean Christopherson } 28801b6d9d9eSSean Christopherson 28811b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 28821b6d9d9eSSean Christopherson return PG_LEVEL_4K; 28831b6d9d9eSSean Christopherson 2884ec607a56SPaolo Bonzini host_level = host_pfn_mapping_level(kvm, gfn, pfn, slot); 2885ec607a56SPaolo Bonzini return min(host_level, max_level); 28861b6d9d9eSSean Christopherson } 28871b6d9d9eSSean Christopherson 288873a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 28890885904dSSean Christopherson { 2890e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 289117eff019SSean Christopherson kvm_pfn_t mask; 28920885904dSSean Christopherson 289373a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 28943cf06612SSean Christopherson 289573a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 289673a3c659SPaolo Bonzini return; 289717eff019SSean Christopherson 289873a3c659SPaolo Bonzini if (is_error_noslot_pfn(fault->pfn) || kvm_is_reserved_pfn(fault->pfn)) 289973a3c659SPaolo Bonzini return; 290017eff019SSean Christopherson 2901e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 290273a3c659SPaolo Bonzini return; 2903293e306eSSean Christopherson 29043cf06612SSean Christopherson /* 29053cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 29063cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 29073cf06612SSean Christopherson */ 290873a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 290973a3c659SPaolo Bonzini fault->gfn, fault->pfn, 291073a3c659SPaolo Bonzini fault->max_level); 291173a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 291273a3c659SPaolo Bonzini return; 29134cd071d1SSean Christopherson 29140885904dSSean Christopherson /* 29154cd071d1SSean Christopherson * mmu_notifier_retry() was successful and mmu_lock is held, so 29164cd071d1SSean Christopherson * the pmd can't be split from under us. 29170885904dSSean Christopherson */ 291873a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 291973a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 292073a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 292173a3c659SPaolo Bonzini fault->pfn &= ~mask; 29220885904dSSean Christopherson } 29230885904dSSean Christopherson 2924536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 2925c50d8ae3SPaolo Bonzini { 2926536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 2927536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 2928c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 2929c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 2930c50d8ae3SPaolo Bonzini /* 2931c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 2932c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 2933c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 2934c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 2935c50d8ae3SPaolo Bonzini * the address. 2936c50d8ae3SPaolo Bonzini */ 2937536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 2938536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 2939536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 2940536f0e6aSPaolo Bonzini fault->goal_level--; 2941c50d8ae3SPaolo Bonzini } 2942c50d8ae3SPaolo Bonzini } 2943c50d8ae3SPaolo Bonzini 294443b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 2945c50d8ae3SPaolo Bonzini { 2946c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 2947c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 294873a3c659SPaolo Bonzini int ret; 294943b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 2950c50d8ae3SPaolo Bonzini 295173a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 29524cd071d1SSean Christopherson 2953f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 295443b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 2955c50d8ae3SPaolo Bonzini /* 2956c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 2957c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 2958c50d8ae3SPaolo Bonzini */ 295973a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 2960536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 2961c50d8ae3SPaolo Bonzini 296243b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 296373a3c659SPaolo Bonzini if (it.level == fault->goal_level) 2964c50d8ae3SPaolo Bonzini break; 2965c50d8ae3SPaolo Bonzini 2966c50d8ae3SPaolo Bonzini drop_large_spte(vcpu, it.sptep); 296703fffc54SSean Christopherson if (is_shadow_present_pte(*it.sptep)) 296803fffc54SSean Christopherson continue; 296903fffc54SSean Christopherson 2970c50d8ae3SPaolo Bonzini sp = kvm_mmu_get_page(vcpu, base_gfn, it.addr, 2971c50d8ae3SPaolo Bonzini it.level - 1, true, ACC_ALL); 2972c50d8ae3SPaolo Bonzini 2973c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 297473a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 297573a3c659SPaolo Bonzini fault->req_level >= it.level) 2976c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 2977c50d8ae3SPaolo Bonzini } 2978c50d8ae3SPaolo Bonzini 2979b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 2980b1a429fbSSean Christopherson return -EFAULT; 2981b1a429fbSSean Christopherson 29828a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 2983a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 298412703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 298512703759SSean Christopherson return ret; 298612703759SSean Christopherson 2987c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 2988c50d8ae3SPaolo Bonzini ++vcpu->stat.pf_fixed; 2989c50d8ae3SPaolo Bonzini return ret; 2990c50d8ae3SPaolo Bonzini } 2991c50d8ae3SPaolo Bonzini 2992c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 2993c50d8ae3SPaolo Bonzini { 2994c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 2995c50d8ae3SPaolo Bonzini } 2996c50d8ae3SPaolo Bonzini 2997c50d8ae3SPaolo Bonzini static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 2998c50d8ae3SPaolo Bonzini { 2999c50d8ae3SPaolo Bonzini /* 3000c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3001c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3002c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3003c50d8ae3SPaolo Bonzini */ 3004c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3005c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3006c50d8ae3SPaolo Bonzini 3007c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3008c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3009c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3010c50d8ae3SPaolo Bonzini } 3011c50d8ae3SPaolo Bonzini 3012c50d8ae3SPaolo Bonzini return -EFAULT; 3013c50d8ae3SPaolo Bonzini } 3014c50d8ae3SPaolo Bonzini 30153a13f4feSPaolo Bonzini static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 30163a13f4feSPaolo Bonzini unsigned int access, int *ret_val) 3017c50d8ae3SPaolo Bonzini { 3018c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 30193a13f4feSPaolo Bonzini if (unlikely(is_error_pfn(fault->pfn))) { 30203a13f4feSPaolo Bonzini *ret_val = kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); 3021c50d8ae3SPaolo Bonzini return true; 3022c50d8ae3SPaolo Bonzini } 3023c50d8ae3SPaolo Bonzini 3024e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 30253a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 30263a13f4feSPaolo Bonzini 30273a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3028c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 302930ab5901SSean Christopherson /* 303030ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 303130ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 303286931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 303386931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 303486931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 303586931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 303686931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 303786931ff7SSean Christopherson * the hardware's). 303830ab5901SSean Christopherson */ 3039*8b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 304086931ff7SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) { 304130ab5901SSean Christopherson *ret_val = RET_PF_EMULATE; 304230ab5901SSean Christopherson return true; 304330ab5901SSean Christopherson } 304430ab5901SSean Christopherson } 3045c50d8ae3SPaolo Bonzini 3046c50d8ae3SPaolo Bonzini return false; 3047c50d8ae3SPaolo Bonzini } 3048c50d8ae3SPaolo Bonzini 30493c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3050c50d8ae3SPaolo Bonzini { 3051c50d8ae3SPaolo Bonzini /* 3052c50d8ae3SPaolo Bonzini * Do not fix the mmio spte with invalid generation number which 3053c50d8ae3SPaolo Bonzini * need to be updated by slow page fault path. 3054c50d8ae3SPaolo Bonzini */ 30553c8ad5a6SPaolo Bonzini if (fault->rsvd) 3056c50d8ae3SPaolo Bonzini return false; 3057c50d8ae3SPaolo Bonzini 3058c50d8ae3SPaolo Bonzini /* See if the page fault is due to an NX violation */ 30593c8ad5a6SPaolo Bonzini if (unlikely(fault->exec && fault->present)) 3060c50d8ae3SPaolo Bonzini return false; 3061c50d8ae3SPaolo Bonzini 3062c50d8ae3SPaolo Bonzini /* 3063c50d8ae3SPaolo Bonzini * #PF can be fast if: 3064c50d8ae3SPaolo Bonzini * 1. The shadow page table entry is not present, which could mean that 3065c50d8ae3SPaolo Bonzini * the fault is potentially caused by access tracking (if enabled). 3066c50d8ae3SPaolo Bonzini * 2. The shadow page table entry is present and the fault 3067c50d8ae3SPaolo Bonzini * is caused by write-protect, that means we just need change the W 3068c50d8ae3SPaolo Bonzini * bit of the spte which can be done out of mmu-lock. 3069c50d8ae3SPaolo Bonzini * 3070c50d8ae3SPaolo Bonzini * However, if access tracking is disabled we know that a non-present 3071c50d8ae3SPaolo Bonzini * page must be a genuine page fault where we have to create a new SPTE. 3072c50d8ae3SPaolo Bonzini * So, if access tracking is disabled, we return true only for write 3073c50d8ae3SPaolo Bonzini * accesses to a present page. 3074c50d8ae3SPaolo Bonzini */ 3075c50d8ae3SPaolo Bonzini 30763c8ad5a6SPaolo Bonzini return shadow_acc_track_mask != 0 || (fault->write && fault->present); 3077c50d8ae3SPaolo Bonzini } 3078c50d8ae3SPaolo Bonzini 3079c50d8ae3SPaolo Bonzini /* 3080c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3081c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3082c50d8ae3SPaolo Bonzini */ 3083c50d8ae3SPaolo Bonzini static bool 3084e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3085c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3086c50d8ae3SPaolo Bonzini { 3087c50d8ae3SPaolo Bonzini /* 3088c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3089c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3090c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3091c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3092c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3093c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3094c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3095c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3096c50d8ae3SPaolo Bonzini * 3097c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3098c50d8ae3SPaolo Bonzini */ 3099c50d8ae3SPaolo Bonzini if (cmpxchg64(sptep, old_spte, new_spte) != old_spte) 3100c50d8ae3SPaolo Bonzini return false; 3101c50d8ae3SPaolo Bonzini 3102e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3103e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3104c50d8ae3SPaolo Bonzini 3105c50d8ae3SPaolo Bonzini return true; 3106c50d8ae3SPaolo Bonzini } 3107c50d8ae3SPaolo Bonzini 31083c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3109c50d8ae3SPaolo Bonzini { 31103c8ad5a6SPaolo Bonzini if (fault->exec) 3111c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3112c50d8ae3SPaolo Bonzini 31133c8ad5a6SPaolo Bonzini if (fault->write) 3114c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3115c50d8ae3SPaolo Bonzini 3116c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3117c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3118c50d8ae3SPaolo Bonzini } 3119c50d8ae3SPaolo Bonzini 3120c50d8ae3SPaolo Bonzini /* 31216e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 31226e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 31236e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 31246e8eb206SDavid Matlack * 31256e8eb206SDavid Matlack * Contract: 31266e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 31276e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 31286e8eb206SDavid Matlack */ 31296e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 31306e8eb206SDavid Matlack { 31316e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 31326e8eb206SDavid Matlack u64 old_spte; 31336e8eb206SDavid Matlack u64 *sptep = NULL; 31346e8eb206SDavid Matlack 31356e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 31366e8eb206SDavid Matlack sptep = iterator.sptep; 31376e8eb206SDavid Matlack *spte = old_spte; 31386e8eb206SDavid Matlack } 31396e8eb206SDavid Matlack 31406e8eb206SDavid Matlack return sptep; 31416e8eb206SDavid Matlack } 31426e8eb206SDavid Matlack 31436e8eb206SDavid Matlack /* 3144c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3145c50d8ae3SPaolo Bonzini */ 31463c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3147c50d8ae3SPaolo Bonzini { 3148c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3149c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3150c50d8ae3SPaolo Bonzini u64 spte = 0ull; 31516e8eb206SDavid Matlack u64 *sptep = NULL; 3152c50d8ae3SPaolo Bonzini uint retry_count = 0; 3153c50d8ae3SPaolo Bonzini 31543c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3155c4371c2aSSean Christopherson return ret; 3156c50d8ae3SPaolo Bonzini 3157c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3158c50d8ae3SPaolo Bonzini 3159c50d8ae3SPaolo Bonzini do { 3160c50d8ae3SPaolo Bonzini u64 new_spte; 3161c50d8ae3SPaolo Bonzini 31626e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 31633c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 31646e8eb206SDavid Matlack else 31653c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3166c50d8ae3SPaolo Bonzini 3167ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3168ec89e643SSean Christopherson break; 3169ec89e643SSean Christopherson 31706e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3171c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3172c50d8ae3SPaolo Bonzini break; 3173c50d8ae3SPaolo Bonzini 3174c50d8ae3SPaolo Bonzini /* 3175c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3176c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3177c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3178c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3179c50d8ae3SPaolo Bonzini * current CPU took the fault. 3180c50d8ae3SPaolo Bonzini * 3181c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3182c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3183c50d8ae3SPaolo Bonzini */ 31843c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3185c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3186c50d8ae3SPaolo Bonzini break; 3187c50d8ae3SPaolo Bonzini } 3188c50d8ae3SPaolo Bonzini 3189c50d8ae3SPaolo Bonzini new_spte = spte; 3190c50d8ae3SPaolo Bonzini 3191c50d8ae3SPaolo Bonzini if (is_access_track_spte(spte)) 3192c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3193c50d8ae3SPaolo Bonzini 3194c50d8ae3SPaolo Bonzini /* 3195c50d8ae3SPaolo Bonzini * Currently, to simplify the code, write-protection can 3196c50d8ae3SPaolo Bonzini * be removed in the fast path only if the SPTE was 3197c50d8ae3SPaolo Bonzini * write-protected for dirty-logging or access tracking. 3198c50d8ae3SPaolo Bonzini */ 31993c8ad5a6SPaolo Bonzini if (fault->write && 3200e6302698SMiaohe Lin spte_can_locklessly_be_made_writable(spte)) { 3201c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3202c50d8ae3SPaolo Bonzini 3203c50d8ae3SPaolo Bonzini /* 320410c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 320510c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 320610c30de0SJunaid Shahid * first page into the dirty-bitmap in 3207c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3208c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3209c50d8ae3SPaolo Bonzini * 3210c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3211c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3212c50d8ae3SPaolo Bonzini */ 321310c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 321410c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3215c50d8ae3SPaolo Bonzini break; 3216c50d8ae3SPaolo Bonzini } 3217c50d8ae3SPaolo Bonzini 3218c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3219c50d8ae3SPaolo Bonzini if (new_spte == spte || 32203c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3221c50d8ae3SPaolo Bonzini break; 3222c50d8ae3SPaolo Bonzini 3223c50d8ae3SPaolo Bonzini /* 3224c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3225c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 32263ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3227c50d8ae3SPaolo Bonzini */ 3228e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3229c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3230c50d8ae3SPaolo Bonzini break; 3231c4371c2aSSean Christopherson } 3232c50d8ae3SPaolo Bonzini 3233c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3234c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3235c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3236c50d8ae3SPaolo Bonzini break; 3237c50d8ae3SPaolo Bonzini } 3238c50d8ae3SPaolo Bonzini 3239c50d8ae3SPaolo Bonzini } while (true); 3240c50d8ae3SPaolo Bonzini 3241f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3242c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3243c50d8ae3SPaolo Bonzini 3244c4371c2aSSean Christopherson return ret; 3245c50d8ae3SPaolo Bonzini } 3246c50d8ae3SPaolo Bonzini 3247c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3248c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3249c50d8ae3SPaolo Bonzini { 3250c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3251c50d8ae3SPaolo Bonzini 3252c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3253c50d8ae3SPaolo Bonzini return; 3254c50d8ae3SPaolo Bonzini 3255e47c4aeeSSean Christopherson sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK); 32569191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 32579191b8f0SPaolo Bonzini return; 325802c00b3aSBen Gardon 3259897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 32606103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 326176eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3262c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3263c50d8ae3SPaolo Bonzini 3264c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3265c50d8ae3SPaolo Bonzini } 3266c50d8ae3SPaolo Bonzini 3267c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 32680c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3269c50d8ae3SPaolo Bonzini ulong roots_to_free) 3270c50d8ae3SPaolo Bonzini { 3271c50d8ae3SPaolo Bonzini int i; 3272c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3273594bef79SPaolo Bonzini bool free_active_root; 3274c50d8ae3SPaolo Bonzini 3275c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3276c50d8ae3SPaolo Bonzini 3277c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3278594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3279594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3280594bef79SPaolo Bonzini 3281594bef79SPaolo Bonzini if (!free_active_root) { 3282c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3283c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3284c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3285c50d8ae3SPaolo Bonzini break; 3286c50d8ae3SPaolo Bonzini 3287c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3288c50d8ae3SPaolo Bonzini return; 3289c50d8ae3SPaolo Bonzini } 3290c50d8ae3SPaolo Bonzini 3291531810caSBen Gardon write_lock(&kvm->mmu_lock); 3292c50d8ae3SPaolo Bonzini 3293c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3294c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 32954d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3296c50d8ae3SPaolo Bonzini &invalid_list); 3297c50d8ae3SPaolo Bonzini 3298c50d8ae3SPaolo Bonzini if (free_active_root) { 3299594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3300b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 330104d45551SSean Christopherson } else if (mmu->pae_root) { 3302c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3303c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3304c834e5e4SSean Christopherson continue; 3305c834e5e4SSean Christopherson 3306c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3307c50d8ae3SPaolo Bonzini &invalid_list); 3308c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3309c50d8ae3SPaolo Bonzini } 3310c50d8ae3SPaolo Bonzini } 3311b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3312b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3313c50d8ae3SPaolo Bonzini } 3314c50d8ae3SPaolo Bonzini 33154d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3316531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3317c50d8ae3SPaolo Bonzini } 3318c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3319c50d8ae3SPaolo Bonzini 33200c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 332125b62c62SSean Christopherson { 332225b62c62SSean Christopherson unsigned long roots_to_free = 0; 332325b62c62SSean Christopherson hpa_t root_hpa; 332425b62c62SSean Christopherson int i; 332525b62c62SSean Christopherson 332625b62c62SSean Christopherson /* 332725b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 332825b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 332925b62c62SSean Christopherson */ 333025b62c62SSean Christopherson WARN_ON_ONCE(mmu->mmu_role.base.guest_mode); 333125b62c62SSean Christopherson 333225b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 333325b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 333425b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 333525b62c62SSean Christopherson continue; 333625b62c62SSean Christopherson 333725b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 333825b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 333925b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 334025b62c62SSean Christopherson } 334125b62c62SSean Christopherson 33420c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 334325b62c62SSean Christopherson } 334425b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 334525b62c62SSean Christopherson 334625b62c62SSean Christopherson 3347c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3348c50d8ae3SPaolo Bonzini { 3349c50d8ae3SPaolo Bonzini int ret = 0; 3350c50d8ae3SPaolo Bonzini 3351995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3352c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3353c50d8ae3SPaolo Bonzini ret = 1; 3354c50d8ae3SPaolo Bonzini } 3355c50d8ae3SPaolo Bonzini 3356c50d8ae3SPaolo Bonzini return ret; 3357c50d8ae3SPaolo Bonzini } 3358c50d8ae3SPaolo Bonzini 33598123f265SSean Christopherson static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva, 33608123f265SSean Christopherson u8 level, bool direct) 3361c50d8ae3SPaolo Bonzini { 3362c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 33638123f265SSean Christopherson 33648123f265SSean Christopherson sp = kvm_mmu_get_page(vcpu, gfn, gva, level, direct, ACC_ALL); 33658123f265SSean Christopherson ++sp->root_count; 33668123f265SSean Christopherson 33678123f265SSean Christopherson return __pa(sp->spt); 33688123f265SSean Christopherson } 33698123f265SSean Christopherson 33708123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 33718123f265SSean Christopherson { 3372b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3373b37233c9SSean Christopherson u8 shadow_root_level = mmu->shadow_root_level; 33748123f265SSean Christopherson hpa_t root; 3375c50d8ae3SPaolo Bonzini unsigned i; 33764a38162eSPaolo Bonzini int r; 33774a38162eSPaolo Bonzini 33784a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 33794a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 33804a38162eSPaolo Bonzini if (r < 0) 33814a38162eSPaolo Bonzini goto out_unlock; 3382c50d8ae3SPaolo Bonzini 3383897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 338402c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3385b9e5603cSPaolo Bonzini mmu->root.hpa = root; 338602c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 33876e6ec584SSean Christopherson root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true); 3388b9e5603cSPaolo Bonzini mmu->root.hpa = root; 33898123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 33904a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 33914a38162eSPaolo Bonzini r = -EIO; 33924a38162eSPaolo Bonzini goto out_unlock; 33934a38162eSPaolo Bonzini } 339473ad1606SSean Christopherson 3395c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3396c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3397c50d8ae3SPaolo Bonzini 33988123f265SSean Christopherson root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 33998123f265SSean Christopherson i << 30, PT32_ROOT_LEVEL, true); 340017e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 340117e368d9SSean Christopherson shadow_me_mask; 3402c50d8ae3SPaolo Bonzini } 3403b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 340473ad1606SSean Christopherson } else { 340573ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 34064a38162eSPaolo Bonzini r = -EIO; 34074a38162eSPaolo Bonzini goto out_unlock; 340873ad1606SSean Christopherson } 34093651c7fcSSean Christopherson 3410b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3411b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 34124a38162eSPaolo Bonzini out_unlock: 34134a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 34144a38162eSPaolo Bonzini return r; 3415c50d8ae3SPaolo Bonzini } 3416c50d8ae3SPaolo Bonzini 34171e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 34181e76a3ceSDavid Stevens { 34191e76a3ceSDavid Stevens struct kvm_memslots *slots; 34201e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3421a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 34221e76a3ceSDavid Stevens 34231e76a3ceSDavid Stevens /* 34241e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 34251e76a3ceSDavid Stevens * taking the lock. 34261e76a3ceSDavid Stevens */ 34271e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34281e76a3ceSDavid Stevens return 0; 34291e76a3ceSDavid Stevens 34301e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 34311e76a3ceSDavid Stevens 34321e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 34331e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34341e76a3ceSDavid Stevens goto out_unlock; 34351e76a3ceSDavid Stevens 34361e76a3ceSDavid Stevens /* 34371e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 34381e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 34391e76a3ceSDavid Stevens */ 34401e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 34411e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 34421e76a3ceSDavid Stevens goto out_success; 34431e76a3ceSDavid Stevens 34441e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 34451e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3446a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 34471e76a3ceSDavid Stevens /* 34481e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 34491e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 34501e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 34511e76a3ceSDavid Stevens * failure to avoid having to track which allocations 34521e76a3ceSDavid Stevens * were made now versus when the memslot was created. 34531e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 34541e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 34551e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 34561e76a3ceSDavid Stevens */ 34571e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 34581e76a3ceSDavid Stevens if (r) 34591e76a3ceSDavid Stevens goto out_unlock; 34601e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 34611e76a3ceSDavid Stevens if (r) 34621e76a3ceSDavid Stevens goto out_unlock; 34631e76a3ceSDavid Stevens } 34641e76a3ceSDavid Stevens } 34651e76a3ceSDavid Stevens 34661e76a3ceSDavid Stevens /* 34671e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 34681e76a3ceSDavid Stevens * all the related pointers are set. 34691e76a3ceSDavid Stevens */ 34701e76a3ceSDavid Stevens out_success: 34711e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 34721e76a3ceSDavid Stevens 34731e76a3ceSDavid Stevens out_unlock: 34741e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 34751e76a3ceSDavid Stevens return r; 34761e76a3ceSDavid Stevens } 34771e76a3ceSDavid Stevens 3478c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3479c50d8ae3SPaolo Bonzini { 3480b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 34816e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3482be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 34838123f265SSean Christopherson hpa_t root; 34844a38162eSPaolo Bonzini unsigned i; 34854a38162eSPaolo Bonzini int r; 3486c50d8ae3SPaolo Bonzini 3487b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3488be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3489c50d8ae3SPaolo Bonzini 3490c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3491c50d8ae3SPaolo Bonzini return 1; 3492c50d8ae3SPaolo Bonzini 3493c50d8ae3SPaolo Bonzini /* 34944a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 34954a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 34964a38162eSPaolo Bonzini */ 34976e0918aeSSean Christopherson if (mmu->root_level == PT32E_ROOT_LEVEL) { 34986e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 34996e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 35006e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 35016e0918aeSSean Christopherson continue; 35026e0918aeSSean Christopherson 35036e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 35046e0918aeSSean Christopherson return 1; 35056e0918aeSSean Christopherson } 35066e0918aeSSean Christopherson } 35076e0918aeSSean Christopherson 35081e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3509d501f747SBen Gardon if (r) 3510d501f747SBen Gardon return r; 3511d501f747SBen Gardon 35124a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35134a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35144a38162eSPaolo Bonzini if (r < 0) 35154a38162eSPaolo Bonzini goto out_unlock; 35164a38162eSPaolo Bonzini 3517c50d8ae3SPaolo Bonzini /* 3518c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3519c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3520c50d8ae3SPaolo Bonzini */ 3521b37233c9SSean Christopherson if (mmu->root_level >= PT64_ROOT_4LEVEL) { 35228123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 3523b37233c9SSean Christopherson mmu->shadow_root_level, false); 3524b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3525be01e8e2SSean Christopherson goto set_root_pgd; 3526c50d8ae3SPaolo Bonzini } 3527c50d8ae3SPaolo Bonzini 35284a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35294a38162eSPaolo Bonzini r = -EIO; 35304a38162eSPaolo Bonzini goto out_unlock; 35314a38162eSPaolo Bonzini } 353273ad1606SSean Christopherson 3533c50d8ae3SPaolo Bonzini /* 3534c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3535c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3536c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3537c50d8ae3SPaolo Bonzini */ 353817e368d9SSean Christopherson pm_mask = PT_PRESENT_MASK | shadow_me_mask; 3539cb0f722aSWei Huang if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL) { 3540c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3541c50d8ae3SPaolo Bonzini 354203ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 35434a38162eSPaolo Bonzini r = -EIO; 35444a38162eSPaolo Bonzini goto out_unlock; 35454a38162eSPaolo Bonzini } 354603ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3547cb0f722aSWei Huang 3548cb0f722aSWei Huang if (mmu->shadow_root_level == PT64_ROOT_5LEVEL) { 3549cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3550cb0f722aSWei Huang r = -EIO; 3551cb0f722aSWei Huang goto out_unlock; 3552cb0f722aSWei Huang } 3553cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3554cb0f722aSWei Huang } 355504d45551SSean Christopherson } 355604d45551SSean Christopherson 3557c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3558c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 35596e6ec584SSean Christopherson 3560b37233c9SSean Christopherson if (mmu->root_level == PT32E_ROOT_LEVEL) { 35616e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3562c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3563c50d8ae3SPaolo Bonzini continue; 3564c50d8ae3SPaolo Bonzini } 35656e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3566c50d8ae3SPaolo Bonzini } 3567c50d8ae3SPaolo Bonzini 35688123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, i << 30, 35698123f265SSean Christopherson PT32_ROOT_LEVEL, false); 3570b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3571c50d8ae3SPaolo Bonzini } 3572c50d8ae3SPaolo Bonzini 3573cb0f722aSWei Huang if (mmu->shadow_root_level == PT64_ROOT_5LEVEL) 3574b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3575cb0f722aSWei Huang else if (mmu->shadow_root_level == PT64_ROOT_4LEVEL) 3576b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3577ba0a194fSSean Christopherson else 3578b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3579c50d8ae3SPaolo Bonzini 3580be01e8e2SSean Christopherson set_root_pgd: 3581b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 35824a38162eSPaolo Bonzini out_unlock: 35834a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3584c50d8ae3SPaolo Bonzini 3585c6c937d6SLike Xu return r; 3586c50d8ae3SPaolo Bonzini } 3587c50d8ae3SPaolo Bonzini 3588748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3589c50d8ae3SPaolo Bonzini { 3590748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3591a717a780SSean Christopherson bool need_pml5 = mmu->shadow_root_level > PT64_ROOT_4LEVEL; 3592cb0f722aSWei Huang u64 *pml5_root = NULL; 3593cb0f722aSWei Huang u64 *pml4_root = NULL; 3594cb0f722aSWei Huang u64 *pae_root; 3595748e52b9SSean Christopherson 3596748e52b9SSean Christopherson /* 3597748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3598748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3599748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3600748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3601748e52b9SSean Christopherson */ 3602748e52b9SSean Christopherson if (mmu->direct_map || mmu->root_level >= PT64_ROOT_4LEVEL || 3603748e52b9SSean Christopherson mmu->shadow_root_level < PT64_ROOT_4LEVEL) 3604748e52b9SSean Christopherson return 0; 3605748e52b9SSean Christopherson 3606a717a780SSean Christopherson /* 3607a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3608a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3609a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3610a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3611a717a780SSean Christopherson * prior MMU would also have required pml5. 3612a717a780SSean Christopherson */ 3613a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3614748e52b9SSean Christopherson return 0; 3615748e52b9SSean Christopherson 3616748e52b9SSean Christopherson /* 3617748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3618748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3619748e52b9SSean Christopherson */ 3620cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3621a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3622748e52b9SSean Christopherson return -EIO; 3623748e52b9SSean Christopherson 36244a98623dSSean Christopherson /* 36254a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 36264a98623dSSean Christopherson * doesn't need to be decrypted. 36274a98623dSSean Christopherson */ 3628748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3629748e52b9SSean Christopherson if (!pae_root) 3630748e52b9SSean Christopherson return -ENOMEM; 3631748e52b9SSean Christopherson 3632cb0f722aSWei Huang #ifdef CONFIG_X86_64 363303ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3634cb0f722aSWei Huang if (!pml4_root) 3635cb0f722aSWei Huang goto err_pml4; 3636cb0f722aSWei Huang 3637a717a780SSean Christopherson if (need_pml5) { 3638cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3639cb0f722aSWei Huang if (!pml5_root) 3640cb0f722aSWei Huang goto err_pml5; 3641748e52b9SSean Christopherson } 3642cb0f722aSWei Huang #endif 3643748e52b9SSean Christopherson 3644748e52b9SSean Christopherson mmu->pae_root = pae_root; 364503ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3646cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3647748e52b9SSean Christopherson 3648748e52b9SSean Christopherson return 0; 3649cb0f722aSWei Huang 3650cb0f722aSWei Huang #ifdef CONFIG_X86_64 3651cb0f722aSWei Huang err_pml5: 3652cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3653cb0f722aSWei Huang err_pml4: 3654cb0f722aSWei Huang free_page((unsigned long)pae_root); 3655cb0f722aSWei Huang return -ENOMEM; 3656cb0f722aSWei Huang #endif 3657c50d8ae3SPaolo Bonzini } 3658c50d8ae3SPaolo Bonzini 3659264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3660264d3dc1SLai Jiangshan { 3661264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3662264d3dc1SLai Jiangshan 366361b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 366461b05a9fSLai Jiangshan return false; 366561b05a9fSLai Jiangshan 3666264d3dc1SLai Jiangshan /* 3667264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3668264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3669264d3dc1SLai Jiangshan * 3670264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3671264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3672264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3673264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3674264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3675264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3676264d3dc1SLai Jiangshan * requirement isn't satisfied. 3677264d3dc1SLai Jiangshan */ 3678264d3dc1SLai Jiangshan smp_rmb(); 3679264d3dc1SLai Jiangshan sp = to_shadow_page(root); 36805d6a3221SSean Christopherson 36815d6a3221SSean Christopherson /* 36825d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 36835d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 36845d6a3221SSean Christopherson */ 36855d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 36865d6a3221SSean Christopherson return false; 36875d6a3221SSean Christopherson 3688264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3689264d3dc1SLai Jiangshan return true; 3690264d3dc1SLai Jiangshan 3691264d3dc1SLai Jiangshan return false; 3692264d3dc1SLai Jiangshan } 3693264d3dc1SLai Jiangshan 3694c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3695c50d8ae3SPaolo Bonzini { 3696c50d8ae3SPaolo Bonzini int i; 3697c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3698c50d8ae3SPaolo Bonzini 3699c50d8ae3SPaolo Bonzini if (vcpu->arch.mmu->direct_map) 3700c50d8ae3SPaolo Bonzini return; 3701c50d8ae3SPaolo Bonzini 3702b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3703c50d8ae3SPaolo Bonzini return; 3704c50d8ae3SPaolo Bonzini 3705c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3706c50d8ae3SPaolo Bonzini 3707c50d8ae3SPaolo Bonzini if (vcpu->arch.mmu->root_level >= PT64_ROOT_4LEVEL) { 3708b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3709e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3710c50d8ae3SPaolo Bonzini 3711264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3712c50d8ae3SPaolo Bonzini return; 3713c50d8ae3SPaolo Bonzini 3714531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 371565855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3716531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3717c50d8ae3SPaolo Bonzini return; 3718c50d8ae3SPaolo Bonzini } 3719c50d8ae3SPaolo Bonzini 3720531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3721c50d8ae3SPaolo Bonzini 3722c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3723c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3724c50d8ae3SPaolo Bonzini 3725c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 3726c50d8ae3SPaolo Bonzini root &= PT64_BASE_ADDR_MASK; 3727e47c4aeeSSean Christopherson sp = to_shadow_page(root); 372865855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3729c50d8ae3SPaolo Bonzini } 3730c50d8ae3SPaolo Bonzini } 3731c50d8ae3SPaolo Bonzini 3732531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3733c50d8ae3SPaolo Bonzini } 3734c50d8ae3SPaolo Bonzini 373561b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 373661b05a9fSLai Jiangshan { 373761b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 373861b05a9fSLai Jiangshan int i; 373961b05a9fSLai Jiangshan 374061b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 374161b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 374261b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 374361b05a9fSLai Jiangshan 374461b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 37450c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 374661b05a9fSLai Jiangshan } 374761b05a9fSLai Jiangshan 37481f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 37495b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3750c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3751c50d8ae3SPaolo Bonzini { 3752c50d8ae3SPaolo Bonzini if (exception) 3753c50d8ae3SPaolo Bonzini exception->error_code = 0; 3754c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3755c50d8ae3SPaolo Bonzini } 3756c50d8ae3SPaolo Bonzini 3757c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3758c50d8ae3SPaolo Bonzini { 3759c50d8ae3SPaolo Bonzini /* 3760c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3761c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3762c50d8ae3SPaolo Bonzini */ 3763c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3764c50d8ae3SPaolo Bonzini return false; 3765c50d8ae3SPaolo Bonzini 3766c50d8ae3SPaolo Bonzini if (direct) 3767c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3768c50d8ae3SPaolo Bonzini 3769c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3770c50d8ae3SPaolo Bonzini } 3771c50d8ae3SPaolo Bonzini 377295fb5b02SBen Gardon /* 377395fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 377495fb5b02SBen Gardon * That SPTE may be non-present. 3775c5c8c7c5SDavid Matlack * 3776c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 377795fb5b02SBen Gardon */ 377839b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3779c50d8ae3SPaolo Bonzini { 3780c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 37812aa07893SSean Christopherson int leaf = -1; 378295fb5b02SBen Gardon u64 spte; 3783c50d8ae3SPaolo Bonzini 378439b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 378539b4d43eSSean Christopherson *root_level = iterator.level; 3786c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3787c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 378895fb5b02SBen Gardon leaf = iterator.level; 3789c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3790c50d8ae3SPaolo Bonzini 3791dde81f94SSean Christopherson sptes[leaf] = spte; 379295fb5b02SBen Gardon } 379395fb5b02SBen Gardon 379495fb5b02SBen Gardon return leaf; 379595fb5b02SBen Gardon } 379695fb5b02SBen Gardon 37979aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 379895fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 379995fb5b02SBen Gardon { 3800dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 380195fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 380239b4d43eSSean Christopherson int root, leaf, level; 380395fb5b02SBen Gardon bool reserved = false; 380495fb5b02SBen Gardon 3805c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3806c5c8c7c5SDavid Matlack 380763c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 380839b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 380995fb5b02SBen Gardon else 381039b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 381195fb5b02SBen Gardon 3812c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 3813c5c8c7c5SDavid Matlack 38142aa07893SSean Christopherson if (unlikely(leaf < 0)) { 38152aa07893SSean Christopherson *sptep = 0ull; 38162aa07893SSean Christopherson return reserved; 38172aa07893SSean Christopherson } 38182aa07893SSean Christopherson 38199aa41879SSean Christopherson *sptep = sptes[leaf]; 38209aa41879SSean Christopherson 38219aa41879SSean Christopherson /* 38229aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 38239aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 38249aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 38259aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 38269aa41879SSean Christopherson */ 38279aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 38289aa41879SSean Christopherson leaf++; 382995fb5b02SBen Gardon 383095fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 383195fb5b02SBen Gardon 38329aa41879SSean Christopherson for (level = root; level >= leaf; level--) 3833961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 3834c50d8ae3SPaolo Bonzini 3835c50d8ae3SPaolo Bonzini if (reserved) { 3836bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 3837c50d8ae3SPaolo Bonzini __func__, addr); 383895fb5b02SBen Gardon for (level = root; level >= leaf; level--) 3839bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 3840bb4cdf3aSSean Christopherson sptes[level], level, 3841961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 3842c50d8ae3SPaolo Bonzini } 3843ddce6208SSean Christopherson 3844c50d8ae3SPaolo Bonzini return reserved; 3845c50d8ae3SPaolo Bonzini } 3846c50d8ae3SPaolo Bonzini 3847c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3848c50d8ae3SPaolo Bonzini { 3849c50d8ae3SPaolo Bonzini u64 spte; 3850c50d8ae3SPaolo Bonzini bool reserved; 3851c50d8ae3SPaolo Bonzini 3852c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 3853c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3854c50d8ae3SPaolo Bonzini 385595fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 3856c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 3857c50d8ae3SPaolo Bonzini return -EINVAL; 3858c50d8ae3SPaolo Bonzini 3859c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 3860c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 38610a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 3862c50d8ae3SPaolo Bonzini 3863c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 3864c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 3865c50d8ae3SPaolo Bonzini 3866c50d8ae3SPaolo Bonzini if (direct) 3867c50d8ae3SPaolo Bonzini addr = 0; 3868c50d8ae3SPaolo Bonzini 3869c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 3870c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 3871c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3872c50d8ae3SPaolo Bonzini } 3873c50d8ae3SPaolo Bonzini 3874c50d8ae3SPaolo Bonzini /* 3875c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 3876c50d8ae3SPaolo Bonzini * the address. 3877c50d8ae3SPaolo Bonzini */ 3878c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3879c50d8ae3SPaolo Bonzini } 3880c50d8ae3SPaolo Bonzini 3881c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 3882b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 3883c50d8ae3SPaolo Bonzini { 3884b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 3885c50d8ae3SPaolo Bonzini return false; 3886c50d8ae3SPaolo Bonzini 3887b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 3888c50d8ae3SPaolo Bonzini return false; 3889c50d8ae3SPaolo Bonzini 3890c50d8ae3SPaolo Bonzini /* 3891c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 3892c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 3893c50d8ae3SPaolo Bonzini */ 38949d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 3895c50d8ae3SPaolo Bonzini return true; 3896c50d8ae3SPaolo Bonzini 3897c50d8ae3SPaolo Bonzini return false; 3898c50d8ae3SPaolo Bonzini } 3899c50d8ae3SPaolo Bonzini 3900c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 3901c50d8ae3SPaolo Bonzini { 3902c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 3903c50d8ae3SPaolo Bonzini u64 spte; 3904c50d8ae3SPaolo Bonzini 3905c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 39063e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 3907c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 3908c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3909c50d8ae3SPaolo Bonzini } 3910c50d8ae3SPaolo Bonzini 39116f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 39126f3c1fc5SLiang Zhang { 39136f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 39146f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 39156f3c1fc5SLiang Zhang 39166f3c1fc5SLiang Zhang if (id << 12 == 0) 39176f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 39186f3c1fc5SLiang Zhang 39196f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 39206f3c1fc5SLiang Zhang } 39216f3c1fc5SLiang Zhang 3922e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 39239f1a8526SSean Christopherson gfn_t gfn) 3924c50d8ae3SPaolo Bonzini { 3925c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 3926c50d8ae3SPaolo Bonzini 39276f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 3928c50d8ae3SPaolo Bonzini arch.gfn = gfn; 3929c50d8ae3SPaolo Bonzini arch.direct_map = vcpu->arch.mmu->direct_map; 3930d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 3931c50d8ae3SPaolo Bonzini 39329f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 39339f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 3934c50d8ae3SPaolo Bonzini } 3935c50d8ae3SPaolo Bonzini 39363647cd04SPaolo Bonzini static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, int *r) 3937c50d8ae3SPaolo Bonzini { 3938e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 3939c50d8ae3SPaolo Bonzini bool async; 3940c50d8ae3SPaolo Bonzini 3941e0c37868SSean Christopherson /* 3942e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 3943e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 3944e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 3945e0c37868SSean Christopherson */ 3946e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 39478f32d5e5SMaxim Levitsky goto out_retry; 3948e0c37868SSean Christopherson 39499cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 3950c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 39519cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 3952e710c5f6SDavid Matlack fault->slot = NULL; 39533647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 39543647cd04SPaolo Bonzini fault->map_writable = false; 3955c50d8ae3SPaolo Bonzini return false; 3956c50d8ae3SPaolo Bonzini } 39579cc13d60SMaxim Levitsky /* 39589cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 39599cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 39609cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 39619cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 39629cc13d60SMaxim Levitsky */ 39639cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 39649cc13d60SMaxim Levitsky !kvm_apicv_activated(vcpu->kvm)) { 39659cc13d60SMaxim Levitsky *r = RET_PF_EMULATE; 39669cc13d60SMaxim Levitsky return true; 39679cc13d60SMaxim Levitsky } 39689cc13d60SMaxim Levitsky } 3969c50d8ae3SPaolo Bonzini 3970c50d8ae3SPaolo Bonzini async = false; 39713647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, 39723647cd04SPaolo Bonzini fault->write, &fault->map_writable, 39733647cd04SPaolo Bonzini &fault->hva); 3974c50d8ae3SPaolo Bonzini if (!async) 3975c50d8ae3SPaolo Bonzini return false; /* *pfn has correct page already */ 3976c50d8ae3SPaolo Bonzini 39772839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 39783647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 39793647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 39803647cd04SPaolo Bonzini trace_kvm_async_pf_doublefault(fault->addr, fault->gfn); 3981c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 39828f32d5e5SMaxim Levitsky goto out_retry; 39833647cd04SPaolo Bonzini } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) 39848f32d5e5SMaxim Levitsky goto out_retry; 3985c50d8ae3SPaolo Bonzini } 3986c50d8ae3SPaolo Bonzini 39873647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, 39883647cd04SPaolo Bonzini fault->write, &fault->map_writable, 39893647cd04SPaolo Bonzini &fault->hva); 3990a7cc099fSAndrei Vagin return false; 39918f32d5e5SMaxim Levitsky 39928f32d5e5SMaxim Levitsky out_retry: 39938f32d5e5SMaxim Levitsky *r = RET_PF_RETRY; 39948f32d5e5SMaxim Levitsky return true; 3995c50d8ae3SPaolo Bonzini } 3996c50d8ae3SPaolo Bonzini 3997a955cad8SSean Christopherson /* 3998a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 3999a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4000a955cad8SSean Christopherson */ 4001a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4002a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 4003a955cad8SSean Christopherson { 4004b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 400518c841e1SSean Christopherson 400618c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 400718c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 400818c841e1SSean Christopherson return true; 400918c841e1SSean Christopherson 401018c841e1SSean Christopherson /* 401118c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 401218c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 401318c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 401418c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 401518c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 401618c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 401718c841e1SSean Christopherson */ 4018527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4019a955cad8SSean Christopherson return true; 4020a955cad8SSean Christopherson 4021a955cad8SSean Christopherson return fault->slot && 4022a955cad8SSean Christopherson mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4023a955cad8SSean Christopherson } 4024a955cad8SSean Christopherson 40254326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4026c50d8ae3SPaolo Bonzini { 402763c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4028c50d8ae3SPaolo Bonzini 40290f90e1c1SSean Christopherson unsigned long mmu_seq; 403083f06fa7SSean Christopherson int r; 4031c50d8ae3SPaolo Bonzini 40323c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4033e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4034e710c5f6SDavid Matlack 4035b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4036c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4037c50d8ae3SPaolo Bonzini 40383c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4039c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4040c4371c2aSSean Christopherson return r; 404183291445SSean Christopherson 4042378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4043c50d8ae3SPaolo Bonzini if (r) 4044c50d8ae3SPaolo Bonzini return r; 4045c50d8ae3SPaolo Bonzini 4046367fd790SSean Christopherson mmu_seq = vcpu->kvm->mmu_notifier_seq; 4047367fd790SSean Christopherson smp_rmb(); 4048367fd790SSean Christopherson 40493647cd04SPaolo Bonzini if (kvm_faultin_pfn(vcpu, fault, &r)) 40508f32d5e5SMaxim Levitsky return r; 4051367fd790SSean Christopherson 40523a13f4feSPaolo Bonzini if (handle_abnormal_pfn(vcpu, fault, ACC_ALL, &r)) 4053367fd790SSean Christopherson return r; 4054367fd790SSean Christopherson 4055367fd790SSean Christopherson r = RET_PF_RETRY; 4056a2855afcSBen Gardon 40570b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4058a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4059a2855afcSBen Gardon else 4060531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4061a2855afcSBen Gardon 4062a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4063367fd790SSean Christopherson goto out_unlock; 4064a955cad8SSean Christopherson 40657bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 40667bd7ded6SSean Christopherson if (r) 4067367fd790SSean Christopherson goto out_unlock; 4068bb18842eSBen Gardon 40690b873fd7SDavid Matlack if (is_tdp_mmu_fault) 40702f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4071bb18842eSBen Gardon else 407243b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 40730f90e1c1SSean Christopherson 4074367fd790SSean Christopherson out_unlock: 40750b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4076a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4077a2855afcSBen Gardon else 4078531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 40793647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4080367fd790SSean Christopherson return r; 4081c50d8ae3SPaolo Bonzini } 4082c50d8ae3SPaolo Bonzini 4083c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4084c501040aSPaolo Bonzini struct kvm_page_fault *fault) 40850f90e1c1SSean Christopherson { 40864326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 40870f90e1c1SSean Christopherson 40880f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 40894326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 40904326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 40910f90e1c1SSean Christopherson } 40920f90e1c1SSean Christopherson 4093c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4094c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4095c50d8ae3SPaolo Bonzini { 4096c50d8ae3SPaolo Bonzini int r = 1; 40979ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4098c50d8ae3SPaolo Bonzini 4099736c291cSSean Christopherson #ifndef CONFIG_X86_64 4100736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4101736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4102736c291cSSean Christopherson return -EFAULT; 4103736c291cSSean Christopherson #endif 4104736c291cSSean Christopherson 4105c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 41069ce372b3SVitaly Kuznetsov if (!flags) { 4107c50d8ae3SPaolo Bonzini trace_kvm_page_fault(fault_address, error_code); 4108c50d8ae3SPaolo Bonzini 4109c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4110c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4111c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4112c50d8ae3SPaolo Bonzini insn_len); 41139ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 411468fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4115c50d8ae3SPaolo Bonzini local_irq_disable(); 41166bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4117c50d8ae3SPaolo Bonzini local_irq_enable(); 41189ce372b3SVitaly Kuznetsov } else { 41199ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4120c50d8ae3SPaolo Bonzini } 41219ce372b3SVitaly Kuznetsov 4122c50d8ae3SPaolo Bonzini return r; 4123c50d8ae3SPaolo Bonzini } 4124c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4125c50d8ae3SPaolo Bonzini 4126c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4127c50d8ae3SPaolo Bonzini { 41284326e57eSPaolo Bonzini while (fault->max_level > PG_LEVEL_4K) { 41294326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 41304326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4131c50d8ae3SPaolo Bonzini 4132cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4133cb9b88c6SSean Christopherson break; 41344326e57eSPaolo Bonzini 41354326e57eSPaolo Bonzini --fault->max_level; 4136c50d8ae3SPaolo Bonzini } 4137c50d8ae3SPaolo Bonzini 41384326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4139c50d8ae3SPaolo Bonzini } 4140c50d8ae3SPaolo Bonzini 414184a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4142c50d8ae3SPaolo Bonzini { 4143c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4144c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4145c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 41465efac074SPaolo Bonzini context->invlpg = NULL; 4147c50d8ae3SPaolo Bonzini context->direct_map = true; 4148c50d8ae3SPaolo Bonzini } 4149c50d8ae3SPaolo Bonzini 4150be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 41510be44352SSean Christopherson union kvm_mmu_page_role role) 41520be44352SSean Christopherson { 4153be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 41545499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4155e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 41560be44352SSean Christopherson } 41570be44352SSean Christopherson 4158c50d8ae3SPaolo Bonzini /* 41595499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 41605499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 41615499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 41625499ea73SPaolo Bonzini * true is returned. 41635499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 41645499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4165c50d8ae3SPaolo Bonzini */ 41665499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 41675499ea73SPaolo Bonzini gpa_t new_pgd, 4168c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4169c50d8ae3SPaolo Bonzini { 4170c50d8ae3SPaolo Bonzini uint i; 4171c50d8ae3SPaolo Bonzini 4172b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 41730be44352SSean Christopherson return true; 41740be44352SSean Christopherson 4175c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 41765499ea73SPaolo Bonzini /* 41775499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 41785499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 41795499ea73SPaolo Bonzini * 0 C 1 2 3 41805499ea73SPaolo Bonzini * 1 C 0 2 3 41815499ea73SPaolo Bonzini * 2 C 0 1 3 41825499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 41835499ea73SPaolo Bonzini */ 4184b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4185b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 41865499ea73SPaolo Bonzini return true; 4187c50d8ae3SPaolo Bonzini } 4188c50d8ae3SPaolo Bonzini 41895499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 41905499ea73SPaolo Bonzini return false; 4191c50d8ae3SPaolo Bonzini } 4192c50d8ae3SPaolo Bonzini 4193c50d8ae3SPaolo Bonzini /* 41945499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 41955499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 41965499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 41975499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 41985499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 41995499ea73SPaolo Bonzini */ 42005499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 42015499ea73SPaolo Bonzini gpa_t new_pgd, 42025499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 42035499ea73SPaolo Bonzini { 42045499ea73SPaolo Bonzini uint i; 42055499ea73SPaolo Bonzini 42065499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 42075499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 42085499ea73SPaolo Bonzini goto hit; 42095499ea73SPaolo Bonzini 42105499ea73SPaolo Bonzini return false; 42115499ea73SPaolo Bonzini 42125499ea73SPaolo Bonzini hit: 42135499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 42145499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 42155499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 42165499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 42175499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 42185499ea73SPaolo Bonzini return true; 42195499ea73SPaolo Bonzini } 42205499ea73SPaolo Bonzini 42215499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 42225499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 42235499ea73SPaolo Bonzini { 42245499ea73SPaolo Bonzini /* 42255499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4226c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4227c50d8ae3SPaolo Bonzini * later if necessary. 4228c50d8ae3SPaolo Bonzini */ 42295499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 42305499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4231c50d8ae3SPaolo Bonzini 42325499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 42335499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 42345499ea73SPaolo Bonzini else 42355499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4236c50d8ae3SPaolo Bonzini } 4237c50d8ae3SPaolo Bonzini 4238d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4239c50d8ae3SPaolo Bonzini { 42400c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 4241d2e5f333SPaolo Bonzini union kvm_mmu_page_role new_role = mmu->mmu_role.base; 42420c1c92f1SPaolo Bonzini 42435499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 42445499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4245b869855bSSean Christopherson return; 4246c50d8ae3SPaolo Bonzini } 4247c50d8ae3SPaolo Bonzini 4248c50d8ae3SPaolo Bonzini /* 4249b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4250b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4251527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4252527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4253b869855bSSean Christopherson */ 4254b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4255b869855bSSean Christopherson 4256b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4257b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4258b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4259b5129100SSean Christopherson } 4260b869855bSSean Christopherson 4261b869855bSSean Christopherson /* 4262b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4263b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4264b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4265b869855bSSean Christopherson * the shadow page tables. 4266c50d8ae3SPaolo Bonzini */ 4267c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4268c50d8ae3SPaolo Bonzini 4269daa5b6c1SBen Gardon /* 4270daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4271daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4272daa5b6c1SBen Gardon */ 4273daa5b6c1SBen Gardon if (!new_role.direct) 4274daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4275b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4276c50d8ae3SPaolo Bonzini } 4277be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4278c50d8ae3SPaolo Bonzini 4279c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4280c50d8ae3SPaolo Bonzini { 4281c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4282c50d8ae3SPaolo Bonzini } 4283c50d8ae3SPaolo Bonzini 4284c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4285c3e5e415SLai Jiangshan unsigned int access) 4286c50d8ae3SPaolo Bonzini { 4287c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4288c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4289c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4290c50d8ae3SPaolo Bonzini return true; 4291c50d8ae3SPaolo Bonzini } 4292c50d8ae3SPaolo Bonzini 4293c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4294c50d8ae3SPaolo Bonzini return true; 4295c50d8ae3SPaolo Bonzini } 4296c50d8ae3SPaolo Bonzini 4297c50d8ae3SPaolo Bonzini return false; 4298c50d8ae3SPaolo Bonzini } 4299c50d8ae3SPaolo Bonzini 4300c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4301c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4302c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4303c50d8ae3SPaolo Bonzini #undef PTTYPE 4304c50d8ae3SPaolo Bonzini 4305c50d8ae3SPaolo Bonzini #define PTTYPE 64 4306c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4307c50d8ae3SPaolo Bonzini #undef PTTYPE 4308c50d8ae3SPaolo Bonzini 4309c50d8ae3SPaolo Bonzini #define PTTYPE 32 4310c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4311c50d8ae3SPaolo Bonzini #undef PTTYPE 4312c50d8ae3SPaolo Bonzini 4313c50d8ae3SPaolo Bonzini static void 4314b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 43155b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4316c50d8ae3SPaolo Bonzini bool pse, bool amd) 4317c50d8ae3SPaolo Bonzini { 4318c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4319c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 43205b7f575cSSean Christopherson u64 high_bits_rsvd; 4321c50d8ae3SPaolo Bonzini 4322c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4323c50d8ae3SPaolo Bonzini 4324c50d8ae3SPaolo Bonzini if (!gbpages) 4325c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4326c50d8ae3SPaolo Bonzini 43275b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 43285b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 43295b7f575cSSean Christopherson else 43305b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 43315b7f575cSSean Christopherson 43325b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 43335b7f575cSSean Christopherson if (!nx) 43345b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 43355b7f575cSSean Christopherson 4336c50d8ae3SPaolo Bonzini /* 4337c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4338c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4339c50d8ae3SPaolo Bonzini */ 4340c50d8ae3SPaolo Bonzini if (amd) 4341c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4342c50d8ae3SPaolo Bonzini 4343c50d8ae3SPaolo Bonzini switch (level) { 4344c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4345c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4346c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4347c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4348c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4349c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4350c50d8ae3SPaolo Bonzini 4351c50d8ae3SPaolo Bonzini if (!pse) { 4352c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4353c50d8ae3SPaolo Bonzini break; 4354c50d8ae3SPaolo Bonzini } 4355c50d8ae3SPaolo Bonzini 4356c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4357c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4358c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4359c50d8ae3SPaolo Bonzini else 4360c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4361c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4362c50d8ae3SPaolo Bonzini break; 4363c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 43645b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 43655b7f575cSSean Christopherson high_bits_rsvd | 43665b7f575cSSean Christopherson rsvd_bits(5, 8) | 43675b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 43685b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 43695b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 43705b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4371c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4372c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4373c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4374c50d8ae3SPaolo Bonzini break; 4375c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 43765b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 43775b7f575cSSean Christopherson nonleaf_bit8_rsvd | 43785b7f575cSSean Christopherson rsvd_bits(7, 7); 4379c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4380c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4381df561f66SGustavo A. R. Silva fallthrough; 4382c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 43835b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 43845b7f575cSSean Christopherson nonleaf_bit8_rsvd | 43855b7f575cSSean Christopherson rsvd_bits(7, 7); 43865b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 43875b7f575cSSean Christopherson gbpages_bit_rsvd; 43885b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 43895b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4390c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4391c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 43925b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 43935b7f575cSSean Christopherson gbpages_bit_rsvd | 4394c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 43955b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4396c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4397c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4398c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4399c50d8ae3SPaolo Bonzini break; 4400c50d8ae3SPaolo Bonzini } 4401c50d8ae3SPaolo Bonzini } 4402c50d8ae3SPaolo Bonzini 440327de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 440427de9250SSean Christopherson { 440527de9250SSean Christopherson /* 440627de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 440727de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 440827de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 440927de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 441027de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 441127de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 441227de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 441327de9250SSean Christopherson */ 441427de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 441527de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 441627de9250SSean Christopherson } 441727de9250SSean Christopherson 4418c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4419c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4420c50d8ae3SPaolo Bonzini { 4421b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 44225b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 442390599c28SSean Christopherson context->root_level, is_efer_nx(context), 442427de9250SSean Christopherson guest_can_use_gbpages(vcpu), 44254e9c0d80SSean Christopherson is_cr4_pse(context), 442623493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4427c50d8ae3SPaolo Bonzini } 4428c50d8ae3SPaolo Bonzini 4429c50d8ae3SPaolo Bonzini static void 4430c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 443184ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4432c50d8ae3SPaolo Bonzini { 44335b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 443484ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4435c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4436c50d8ae3SPaolo Bonzini 443784ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 443884ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 443984ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 444084ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 444184ea5c09SLai Jiangshan 44425b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 44435b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 444484ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 444584ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 44465b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4447c50d8ae3SPaolo Bonzini 4448c50d8ae3SPaolo Bonzini /* large page */ 4449c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4450c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 445184ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 445284ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4453c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4454c50d8ae3SPaolo Bonzini 4455c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4456c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4457c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4458c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4459c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4460c50d8ae3SPaolo Bonzini if (!execonly) { 4461c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4462c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4463c50d8ae3SPaolo Bonzini } 4464c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4465c50d8ae3SPaolo Bonzini } 4466c50d8ae3SPaolo Bonzini 4467c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 446884ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4469c50d8ae3SPaolo Bonzini { 4470c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 447184ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 447284ea5c09SLai Jiangshan huge_page_level); 4473c50d8ae3SPaolo Bonzini } 4474c50d8ae3SPaolo Bonzini 44756f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 44766f8e65a6SSean Christopherson { 44776f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 44786f8e65a6SSean Christopherson } 44796f8e65a6SSean Christopherson 4480c50d8ae3SPaolo Bonzini /* 4481c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4482c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4483c50d8ae3SPaolo Bonzini * follow the features in guest. 4484c50d8ae3SPaolo Bonzini */ 448516be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 448616be1d12SSean Christopherson struct kvm_mmu *context) 4487c50d8ae3SPaolo Bonzini { 4488112022bdSSean Christopherson /* 4489112022bdSSean Christopherson * KVM uses NX when TDP is disabled to handle a variety of scenarios, 4490112022bdSSean Christopherson * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 4491112022bdSSean Christopherson * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 4492112022bdSSean Christopherson * The iTLB multi-hit workaround can be toggled at any time, so assume 4493112022bdSSean Christopherson * NX can be used by any non-nested shadow MMU to avoid having to reset 4494112022bdSSean Christopherson * MMU contexts. Note, KVM forces EFER.NX=1 when TDP is disabled. 4495112022bdSSean Christopherson */ 449690599c28SSean Christopherson bool uses_nx = is_efer_nx(context) || !tdp_enabled; 44978c985b2dSSean Christopherson 44988c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 44998c985b2dSSean Christopherson bool is_amd = true; 45008c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 45018c985b2dSSean Christopherson bool is_pse = false; 4502c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4503c50d8ae3SPaolo Bonzini int i; 4504c50d8ae3SPaolo Bonzini 45058c985b2dSSean Christopherson WARN_ON_ONCE(context->shadow_root_level < PT32E_ROOT_LEVEL); 45068c985b2dSSean Christopherson 4507c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4508b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4509c50d8ae3SPaolo Bonzini context->shadow_root_level, uses_nx, 451027de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4511c50d8ae3SPaolo Bonzini 4512c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4513c50d8ae3SPaolo Bonzini return; 4514c50d8ae3SPaolo Bonzini 4515c50d8ae3SPaolo Bonzini for (i = context->shadow_root_level; --i >= 0;) { 4516c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4517c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4518c50d8ae3SPaolo Bonzini } 4519c50d8ae3SPaolo Bonzini 4520c50d8ae3SPaolo Bonzini } 4521c50d8ae3SPaolo Bonzini 4522c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4523c50d8ae3SPaolo Bonzini { 4524c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4525c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4526c50d8ae3SPaolo Bonzini } 4527c50d8ae3SPaolo Bonzini 4528c50d8ae3SPaolo Bonzini /* 4529c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4530c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4531c50d8ae3SPaolo Bonzini */ 4532c50d8ae3SPaolo Bonzini static void 4533e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4534c50d8ae3SPaolo Bonzini { 4535c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4536c50d8ae3SPaolo Bonzini int i; 4537c50d8ae3SPaolo Bonzini 4538c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4539c50d8ae3SPaolo Bonzini 4540c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4541b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4542c50d8ae3SPaolo Bonzini context->shadow_root_level, false, 4543c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 45448c985b2dSSean Christopherson false, true); 4545c50d8ae3SPaolo Bonzini else 4546c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 454784ea5c09SLai Jiangshan reserved_hpa_bits(), false, 454884ea5c09SLai Jiangshan max_huge_page_level); 4549c50d8ae3SPaolo Bonzini 4550c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4551c50d8ae3SPaolo Bonzini return; 4552c50d8ae3SPaolo Bonzini 4553c50d8ae3SPaolo Bonzini for (i = context->shadow_root_level; --i >= 0;) { 4554c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4555c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4556c50d8ae3SPaolo Bonzini } 4557c50d8ae3SPaolo Bonzini } 4558c50d8ae3SPaolo Bonzini 4559c50d8ae3SPaolo Bonzini /* 4560c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4561c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4562c50d8ae3SPaolo Bonzini */ 4563c50d8ae3SPaolo Bonzini static void 4564e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4565c50d8ae3SPaolo Bonzini { 4566c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 456784ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 456884ea5c09SLai Jiangshan max_huge_page_level); 4569c50d8ae3SPaolo Bonzini } 4570c50d8ae3SPaolo Bonzini 4571c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4572c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4573c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4574c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4575c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4576c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4577c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4578c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4579c50d8ae3SPaolo Bonzini 4580c50d8ae3SPaolo Bonzini 4581c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4582c50d8ae3SPaolo Bonzini { 4583c50d8ae3SPaolo Bonzini unsigned byte; 4584c50d8ae3SPaolo Bonzini 4585c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4586c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4587c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4588c50d8ae3SPaolo Bonzini 4589c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4590c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4591c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 459290599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4593c50d8ae3SPaolo Bonzini 4594c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4595c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4596c50d8ae3SPaolo Bonzini 4597c50d8ae3SPaolo Bonzini /* 4598c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4599c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4600c50d8ae3SPaolo Bonzini */ 4601c50d8ae3SPaolo Bonzini 4602c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4603c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4604c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4605c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4606c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4607c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4608c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4609c50d8ae3SPaolo Bonzini u8 smepf = 0; 4610c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4611c50d8ae3SPaolo Bonzini u8 smapf = 0; 4612c50d8ae3SPaolo Bonzini 4613c50d8ae3SPaolo Bonzini if (!ept) { 4614c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4615c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4616c50d8ae3SPaolo Bonzini 4617c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 461890599c28SSean Christopherson if (!efer_nx) 4619c50d8ae3SPaolo Bonzini ff = 0; 4620c50d8ae3SPaolo Bonzini 4621c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4622c50d8ae3SPaolo Bonzini if (!cr0_wp) 4623c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4624c50d8ae3SPaolo Bonzini 4625c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4626c50d8ae3SPaolo Bonzini if (cr4_smep) 4627c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4628c50d8ae3SPaolo Bonzini 4629c50d8ae3SPaolo Bonzini /* 4630c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4631c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4632c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4633c50d8ae3SPaolo Bonzini * conditions are true: 4634c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4635c50d8ae3SPaolo Bonzini * - A user page is accessed 4636c50d8ae3SPaolo Bonzini * - The access is not a fetch 46374f4aa80eSLai Jiangshan * - The access is supervisor mode 46384f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4639c50d8ae3SPaolo Bonzini * 464094b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 464194b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4642c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4643c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4644c50d8ae3SPaolo Bonzini */ 4645c50d8ae3SPaolo Bonzini if (cr4_smap) 4646c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4647c50d8ae3SPaolo Bonzini } 4648c50d8ae3SPaolo Bonzini 4649c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4650c50d8ae3SPaolo Bonzini } 4651c50d8ae3SPaolo Bonzini } 4652c50d8ae3SPaolo Bonzini 4653c50d8ae3SPaolo Bonzini /* 4654c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4655c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4656c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4657c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4658c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4659c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4660c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4661c50d8ae3SPaolo Bonzini * 4662c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4663c50d8ae3SPaolo Bonzini * page tables and the machine state: 4664c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4665c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4666c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4667c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4668c50d8ae3SPaolo Bonzini * 4669c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4670c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4671c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4672c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4673c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4674c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4675c50d8ae3SPaolo Bonzini * only will be masked away. 4676c50d8ae3SPaolo Bonzini */ 46772e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4678c50d8ae3SPaolo Bonzini { 4679c50d8ae3SPaolo Bonzini unsigned bit; 4680c50d8ae3SPaolo Bonzini bool wp; 4681c50d8ae3SPaolo Bonzini 4682c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4683a3ca5281SChenyi Qiang 4684a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4685c50d8ae3SPaolo Bonzini return; 4686c50d8ae3SPaolo Bonzini 46872e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4688c50d8ae3SPaolo Bonzini 4689c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4690c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4691c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4692c50d8ae3SPaolo Bonzini 4693c50d8ae3SPaolo Bonzini pfec = bit << 1; 4694c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4695c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4696c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4697c50d8ae3SPaolo Bonzini 4698c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4699c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4700c50d8ae3SPaolo Bonzini 4701c50d8ae3SPaolo Bonzini /* 4702c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4703c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4704c50d8ae3SPaolo Bonzini */ 4705c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4706c50d8ae3SPaolo Bonzini /* 4707c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4708c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4709c50d8ae3SPaolo Bonzini */ 4710c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4711c50d8ae3SPaolo Bonzini 4712c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4713c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4714c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4715c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4716c50d8ae3SPaolo Bonzini 4717c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4718c50d8ae3SPaolo Bonzini } 4719c50d8ae3SPaolo Bonzini } 4720c50d8ae3SPaolo Bonzini 4721533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4722533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4723c50d8ae3SPaolo Bonzini { 4724533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4725533f9a4bSSean Christopherson return; 4726c50d8ae3SPaolo Bonzini 4727533f9a4bSSean Christopherson reset_rsvds_bits_mask(vcpu, mmu); 4728533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4729533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4730c50d8ae3SPaolo Bonzini } 4731c50d8ae3SPaolo Bonzini 4732fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4733c50d8ae3SPaolo Bonzini { 4734c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4735c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4736c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4737c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4738c50d8ae3SPaolo Bonzini context->direct_map = false; 4739c50d8ae3SPaolo Bonzini } 4740c50d8ae3SPaolo Bonzini 474184a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4742c50d8ae3SPaolo Bonzini { 4743c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4744c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4745c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4746c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4747c50d8ae3SPaolo Bonzini context->direct_map = false; 4748c50d8ae3SPaolo Bonzini } 4749c50d8ae3SPaolo Bonzini 47508626c120SSean Christopherson static union kvm_mmu_extended_role kvm_calc_mmu_role_ext(struct kvm_vcpu *vcpu, 47518626c120SSean Christopherson struct kvm_mmu_role_regs *regs) 4752c50d8ae3SPaolo Bonzini { 4753c50d8ae3SPaolo Bonzini union kvm_mmu_extended_role ext = {0}; 4754c50d8ae3SPaolo Bonzini 4755ca8d664fSSean Christopherson if (____is_cr0_pg(regs)) { 4756ca8d664fSSean Christopherson ext.cr0_pg = 1; 47578626c120SSean Christopherson ext.cr4_pae = ____is_cr4_pae(regs); 47588626c120SSean Christopherson ext.cr4_smep = ____is_cr4_smep(regs); 47598626c120SSean Christopherson ext.cr4_smap = ____is_cr4_smap(regs); 47608626c120SSean Christopherson ext.cr4_pse = ____is_cr4_pse(regs); 476184c679f5SSean Christopherson 476284c679f5SSean Christopherson /* PKEY and LA57 are active iff long mode is active. */ 476384c679f5SSean Christopherson ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 476484c679f5SSean Christopherson ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 4765b8453cdcSMaxim Levitsky ext.efer_lma = ____is_efer_lma(regs); 4766ca8d664fSSean Christopherson } 4767c50d8ae3SPaolo Bonzini 4768c50d8ae3SPaolo Bonzini ext.valid = 1; 4769c50d8ae3SPaolo Bonzini 4770c50d8ae3SPaolo Bonzini return ext; 4771c50d8ae3SPaolo Bonzini } 4772c50d8ae3SPaolo Bonzini 4773c50d8ae3SPaolo Bonzini static union kvm_mmu_role kvm_calc_mmu_role_common(struct kvm_vcpu *vcpu, 47748626c120SSean Christopherson struct kvm_mmu_role_regs *regs, 4775c50d8ae3SPaolo Bonzini bool base_only) 4776c50d8ae3SPaolo Bonzini { 4777c50d8ae3SPaolo Bonzini union kvm_mmu_role role = {0}; 4778c50d8ae3SPaolo Bonzini 4779c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 4780ca8d664fSSean Christopherson if (____is_cr0_pg(regs)) { 4781167f8a5cSSean Christopherson role.base.efer_nx = ____is_efer_nx(regs); 47828626c120SSean Christopherson role.base.cr0_wp = ____is_cr0_wp(regs); 4783ca8d664fSSean Christopherson } 4784c50d8ae3SPaolo Bonzini role.base.smm = is_smm(vcpu); 4785c50d8ae3SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4786c50d8ae3SPaolo Bonzini 4787c50d8ae3SPaolo Bonzini if (base_only) 4788c50d8ae3SPaolo Bonzini return role; 4789c50d8ae3SPaolo Bonzini 47908626c120SSean Christopherson role.ext = kvm_calc_mmu_role_ext(vcpu, regs); 4791c50d8ae3SPaolo Bonzini 4792c50d8ae3SPaolo Bonzini return role; 4793c50d8ae3SPaolo Bonzini } 4794c50d8ae3SPaolo Bonzini 4795d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 4796d468d94bSSean Christopherson { 4797746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 4798746700d2SWei Huang if (tdp_root_level) 4799746700d2SWei Huang return tdp_root_level; 4800746700d2SWei Huang 4801d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 480283013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 4803d468d94bSSean Christopherson return 4; 4804d468d94bSSean Christopherson 480583013059SSean Christopherson return max_tdp_level; 4806d468d94bSSean Christopherson } 4807d468d94bSSean Christopherson 4808c50d8ae3SPaolo Bonzini static union kvm_mmu_role 48098626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 48108626c120SSean Christopherson struct kvm_mmu_role_regs *regs, bool base_only) 4811c50d8ae3SPaolo Bonzini { 48128626c120SSean Christopherson union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu, regs, base_only); 4813c50d8ae3SPaolo Bonzini 4814c50d8ae3SPaolo Bonzini role.base.ad_disabled = (shadow_accessed_mask == 0); 4815d468d94bSSean Christopherson role.base.level = kvm_mmu_get_tdp_level(vcpu); 4816c50d8ae3SPaolo Bonzini role.base.direct = true; 4817bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 4818c50d8ae3SPaolo Bonzini 4819c50d8ae3SPaolo Bonzini return role; 4820c50d8ae3SPaolo Bonzini } 4821c50d8ae3SPaolo Bonzini 4822c50d8ae3SPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) 4823c50d8ae3SPaolo Bonzini { 48248c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 48258626c120SSean Christopherson struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 4826c50d8ae3SPaolo Bonzini union kvm_mmu_role new_role = 48278626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(vcpu, ®s, false); 4828c50d8ae3SPaolo Bonzini 4829c50d8ae3SPaolo Bonzini if (new_role.as_u64 == context->mmu_role.as_u64) 4830c50d8ae3SPaolo Bonzini return; 4831c50d8ae3SPaolo Bonzini 4832c50d8ae3SPaolo Bonzini context->mmu_role.as_u64 = new_role.as_u64; 48337a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 4834c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 48355efac074SPaolo Bonzini context->invlpg = NULL; 4836d468d94bSSean Christopherson context->shadow_root_level = kvm_mmu_get_tdp_level(vcpu); 4837c50d8ae3SPaolo Bonzini context->direct_map = true; 4838d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4839c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4840c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 4841f4bd6f73SSean Christopherson context->root_level = role_regs_to_root_level(®s); 4842c50d8ae3SPaolo Bonzini 484336f26787SSean Christopherson if (!is_cr0_pg(context)) 4844c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 484536f26787SSean Christopherson else if (is_cr4_pae(context)) 4846c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4847f4bd6f73SSean Christopherson else 4848c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4849c50d8ae3SPaolo Bonzini 4850533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4851e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 4852c50d8ae3SPaolo Bonzini } 4853c50d8ae3SPaolo Bonzini 4854c50d8ae3SPaolo Bonzini static union kvm_mmu_role 48558626c120SSean Christopherson kvm_calc_shadow_root_page_role_common(struct kvm_vcpu *vcpu, 48568626c120SSean Christopherson struct kvm_mmu_role_regs *regs, bool base_only) 4857c50d8ae3SPaolo Bonzini { 48588626c120SSean Christopherson union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu, regs, base_only); 4859c50d8ae3SPaolo Bonzini 48608626c120SSean Christopherson role.base.smep_andnot_wp = role.ext.cr4_smep && !____is_cr0_wp(regs); 48618626c120SSean Christopherson role.base.smap_andnot_wp = role.ext.cr4_smap && !____is_cr0_wp(regs); 4862bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = ____is_cr0_pg(regs) && !____is_cr4_pae(regs); 4863c50d8ae3SPaolo Bonzini 486459505b55SSean Christopherson return role; 486559505b55SSean Christopherson } 486659505b55SSean Christopherson 486759505b55SSean Christopherson static union kvm_mmu_role 48688626c120SSean Christopherson kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, 48698626c120SSean Christopherson struct kvm_mmu_role_regs *regs, bool base_only) 487059505b55SSean Christopherson { 487159505b55SSean Christopherson union kvm_mmu_role role = 48728626c120SSean Christopherson kvm_calc_shadow_root_page_role_common(vcpu, regs, base_only); 487359505b55SSean Christopherson 48748626c120SSean Christopherson role.base.direct = !____is_cr0_pg(regs); 487559505b55SSean Christopherson 48768626c120SSean Christopherson if (!____is_efer_lma(regs)) 4877c50d8ae3SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 48788626c120SSean Christopherson else if (____is_cr4_la57(regs)) 4879c50d8ae3SPaolo Bonzini role.base.level = PT64_ROOT_5LEVEL; 4880c50d8ae3SPaolo Bonzini else 4881c50d8ae3SPaolo Bonzini role.base.level = PT64_ROOT_4LEVEL; 4882c50d8ae3SPaolo Bonzini 4883c50d8ae3SPaolo Bonzini return role; 4884c50d8ae3SPaolo Bonzini } 4885c50d8ae3SPaolo Bonzini 48868c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 4887594e91a1SSean Christopherson struct kvm_mmu_role_regs *regs, 48888c008659SPaolo Bonzini union kvm_mmu_role new_role) 4889c50d8ae3SPaolo Bonzini { 489018db1b17SSean Christopherson if (new_role.as_u64 == context->mmu_role.as_u64) 489118db1b17SSean Christopherson return; 4892c50d8ae3SPaolo Bonzini 4893c50d8ae3SPaolo Bonzini context->mmu_role.as_u64 = new_role.as_u64; 489418db1b17SSean Christopherson 489536f26787SSean Christopherson if (!is_cr0_pg(context)) 489684a16226SSean Christopherson nonpaging_init_context(context); 489736f26787SSean Christopherson else if (is_cr4_pae(context)) 4898fe660f72SSean Christopherson paging64_init_context(context); 4899c50d8ae3SPaolo Bonzini else 490084a16226SSean Christopherson paging32_init_context(context); 4901f4bd6f73SSean Christopherson context->root_level = role_regs_to_root_level(regs); 4902c50d8ae3SPaolo Bonzini 4903533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4904d555f705SSean Christopherson context->shadow_root_level = new_role.base.level; 4905d555f705SSean Christopherson 4906c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 4907c50d8ae3SPaolo Bonzini } 49080f04a2acSVitaly Kuznetsov 4909594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 4910594e91a1SSean Christopherson struct kvm_mmu_role_regs *regs) 49110f04a2acSVitaly Kuznetsov { 49128c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 49130f04a2acSVitaly Kuznetsov union kvm_mmu_role new_role = 49148626c120SSean Christopherson kvm_calc_shadow_mmu_root_page_role(vcpu, regs, false); 49150f04a2acSVitaly Kuznetsov 4916594e91a1SSean Christopherson shadow_mmu_init_context(vcpu, context, regs, new_role); 49170f04a2acSVitaly Kuznetsov } 49180f04a2acSVitaly Kuznetsov 491959505b55SSean Christopherson static union kvm_mmu_role 49208626c120SSean Christopherson kvm_calc_shadow_npt_root_page_role(struct kvm_vcpu *vcpu, 49218626c120SSean Christopherson struct kvm_mmu_role_regs *regs) 492259505b55SSean Christopherson { 492359505b55SSean Christopherson union kvm_mmu_role role = 49248626c120SSean Christopherson kvm_calc_shadow_root_page_role_common(vcpu, regs, false); 492559505b55SSean Christopherson 492659505b55SSean Christopherson role.base.direct = false; 4927d468d94bSSean Christopherson role.base.level = kvm_mmu_get_tdp_level(vcpu); 492859505b55SSean Christopherson 492959505b55SSean Christopherson return role; 493059505b55SSean Christopherson } 493159505b55SSean Christopherson 4932dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 4933dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 49340f04a2acSVitaly Kuznetsov { 49358c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4936594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 4937594e91a1SSean Christopherson .cr0 = cr0, 493828f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 4939594e91a1SSean Christopherson .efer = efer, 4940594e91a1SSean Christopherson }; 49418626c120SSean Christopherson union kvm_mmu_role new_role; 49420f04a2acSVitaly Kuznetsov 49438626c120SSean Christopherson new_role = kvm_calc_shadow_npt_root_page_role(vcpu, ®s); 4944a506fdd2SVitaly Kuznetsov 4945594e91a1SSean Christopherson shadow_mmu_init_context(vcpu, context, ®s, new_role); 4946d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 49470f04a2acSVitaly Kuznetsov } 49480f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 4949c50d8ae3SPaolo Bonzini 4950c50d8ae3SPaolo Bonzini static union kvm_mmu_role 4951c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 4952bb1fcc70SSean Christopherson bool execonly, u8 level) 4953c50d8ae3SPaolo Bonzini { 4954c50d8ae3SPaolo Bonzini union kvm_mmu_role role = {0}; 4955c50d8ae3SPaolo Bonzini 4956c50d8ae3SPaolo Bonzini /* SMM flag is inherited from root_mmu */ 4957c50d8ae3SPaolo Bonzini role.base.smm = vcpu->arch.root_mmu.mmu_role.base.smm; 4958c50d8ae3SPaolo Bonzini 4959bb1fcc70SSean Christopherson role.base.level = level; 4960bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 4961c50d8ae3SPaolo Bonzini role.base.direct = false; 4962c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 4963c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 4964c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 4965c50d8ae3SPaolo Bonzini 4966cd6767c3SSean Christopherson /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 4967cd6767c3SSean Christopherson role.ext.word = 0; 4968c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 4969cd6767c3SSean Christopherson role.ext.valid = 1; 4970c50d8ae3SPaolo Bonzini 4971c50d8ae3SPaolo Bonzini return role; 4972c50d8ae3SPaolo Bonzini } 4973c50d8ae3SPaolo Bonzini 4974c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 4975cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 4976cc022ae1SLai Jiangshan gpa_t new_eptp) 4977c50d8ae3SPaolo Bonzini { 49788c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4979bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 4980c50d8ae3SPaolo Bonzini union kvm_mmu_role new_role = 4981c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 4982bb1fcc70SSean Christopherson execonly, level); 4983c50d8ae3SPaolo Bonzini 49843cffc89dSPaolo Bonzini if (new_role.as_u64 != context->mmu_role.as_u64) { 498518db1b17SSean Christopherson context->mmu_role.as_u64 = new_role.as_u64; 498618db1b17SSean Christopherson 4987bb1fcc70SSean Christopherson context->shadow_root_level = level; 4988c50d8ae3SPaolo Bonzini 4989c50d8ae3SPaolo Bonzini context->ept_ad = accessed_dirty; 4990c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 4991c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 4992c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 4993c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 4994bb1fcc70SSean Christopherson context->root_level = level; 4995c50d8ae3SPaolo Bonzini context->direct_map = false; 4996c596f147SSean Christopherson update_permission_bitmask(context, true); 499728f091bcSPaolo Bonzini context->pkru_mask = 0; 4998cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 4999e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5000c50d8ae3SPaolo Bonzini } 50013cffc89dSPaolo Bonzini 5002d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 50033cffc89dSPaolo Bonzini } 5004c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5005c50d8ae3SPaolo Bonzini 5006c50d8ae3SPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu) 5007c50d8ae3SPaolo Bonzini { 50088c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5009594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5010c50d8ae3SPaolo Bonzini 5011594e91a1SSean Christopherson kvm_init_shadow_mmu(vcpu, ®s); 5012929d1cfaSPaolo Bonzini 5013d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5014c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5015c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5016c50d8ae3SPaolo Bonzini } 5017c50d8ae3SPaolo Bonzini 50188626c120SSean Christopherson static union kvm_mmu_role 50198626c120SSean Christopherson kvm_calc_nested_mmu_role(struct kvm_vcpu *vcpu, struct kvm_mmu_role_regs *regs) 5020654430efSSean Christopherson { 50218626c120SSean Christopherson union kvm_mmu_role role; 50228626c120SSean Christopherson 50238626c120SSean Christopherson role = kvm_calc_shadow_root_page_role_common(vcpu, regs, false); 5024654430efSSean Christopherson 5025654430efSSean Christopherson /* 5026654430efSSean Christopherson * Nested MMUs are used only for walking L2's gva->gpa, they never have 5027654430efSSean Christopherson * shadow pages of their own and so "direct" has no meaning. Set it 5028654430efSSean Christopherson * to "true" to try to detect bogus usage of the nested MMU. 5029654430efSSean Christopherson */ 5030654430efSSean Christopherson role.base.direct = true; 5031f4bd6f73SSean Christopherson role.base.level = role_regs_to_root_level(regs); 5032654430efSSean Christopherson return role; 5033654430efSSean Christopherson } 5034654430efSSean Christopherson 5035c50d8ae3SPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu) 5036c50d8ae3SPaolo Bonzini { 50378626c120SSean Christopherson struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 50388626c120SSean Christopherson union kvm_mmu_role new_role = kvm_calc_nested_mmu_role(vcpu, ®s); 5039c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5040c50d8ae3SPaolo Bonzini 5041c50d8ae3SPaolo Bonzini if (new_role.as_u64 == g_context->mmu_role.as_u64) 5042c50d8ae3SPaolo Bonzini return; 5043c50d8ae3SPaolo Bonzini 5044c50d8ae3SPaolo Bonzini g_context->mmu_role.as_u64 = new_role.as_u64; 5045d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5046c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5047c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 50485472fcd4SSean Christopherson g_context->root_level = new_role.base.level; 5049c50d8ae3SPaolo Bonzini 5050c50d8ae3SPaolo Bonzini /* 50515efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 50525efac074SPaolo Bonzini * SPTEs. 50535efac074SPaolo Bonzini */ 50545efac074SPaolo Bonzini g_context->invlpg = NULL; 50555efac074SPaolo Bonzini 50565efac074SPaolo Bonzini /* 5057c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5058c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5059c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5060c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5061c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5062c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5063c50d8ae3SPaolo Bonzini */ 5064fa4b5588SSean Christopherson if (!is_paging(vcpu)) 50651f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5066fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 50671f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5068fa4b5588SSean Christopherson else if (is_pae(vcpu)) 50691f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5070fa4b5588SSean Christopherson else 50711f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5072fa4b5588SSean Christopherson 5073533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5074c50d8ae3SPaolo Bonzini } 5075c50d8ae3SPaolo Bonzini 5076c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5077c50d8ae3SPaolo Bonzini { 5078c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5079c50d8ae3SPaolo Bonzini init_kvm_nested_mmu(vcpu); 5080c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5081c50d8ae3SPaolo Bonzini init_kvm_tdp_mmu(vcpu); 5082c50d8ae3SPaolo Bonzini else 5083c50d8ae3SPaolo Bonzini init_kvm_softmmu(vcpu); 5084c50d8ae3SPaolo Bonzini } 5085c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5086c50d8ae3SPaolo Bonzini 508749c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 508849c6f875SSean Christopherson { 508949c6f875SSean Christopherson /* 509049c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 509149c6f875SSean Christopherson * information is factored into reserved bit calculations. 5092feb627e8SVitaly Kuznetsov * 5093feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5094feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5095feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5096feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5097feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5098feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5099feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 510049c6f875SSean Christopherson */ 510149c6f875SSean Christopherson vcpu->arch.root_mmu.mmu_role.ext.valid = 0; 510249c6f875SSean Christopherson vcpu->arch.guest_mmu.mmu_role.ext.valid = 0; 510349c6f875SSean Christopherson vcpu->arch.nested_mmu.mmu_role.ext.valid = 0; 510449c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 510563f5a190SSean Christopherson 510663f5a190SSean Christopherson /* 5107feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5108feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 510963f5a190SSean Christopherson */ 5110feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 511149c6f875SSean Christopherson } 511249c6f875SSean Christopherson 5113c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5114c50d8ae3SPaolo Bonzini { 5115c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5116c9060662SSean Christopherson kvm_init_mmu(vcpu); 5117c50d8ae3SPaolo Bonzini } 5118c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5119c50d8ae3SPaolo Bonzini 5120c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5121c50d8ae3SPaolo Bonzini { 5122c50d8ae3SPaolo Bonzini int r; 5123c50d8ae3SPaolo Bonzini 5124378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->direct_map); 5125c50d8ae3SPaolo Bonzini if (r) 5126c50d8ae3SPaolo Bonzini goto out; 5127748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5128c50d8ae3SPaolo Bonzini if (r) 5129c50d8ae3SPaolo Bonzini goto out; 51304a38162eSPaolo Bonzini if (vcpu->arch.mmu->direct_map) 51316e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 51326e6ec584SSean Christopherson else 51336e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5134c50d8ae3SPaolo Bonzini if (r) 5135c50d8ae3SPaolo Bonzini goto out; 5136a91f387bSSean Christopherson 5137a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5138a91f387bSSean Christopherson 5139727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5140db01416bSSean Christopherson 5141db01416bSSean Christopherson /* 5142db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5143db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5144db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5145db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5146db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5147db01416bSSean Christopherson */ 5148e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5149c50d8ae3SPaolo Bonzini out: 5150c50d8ae3SPaolo Bonzini return r; 5151c50d8ae3SPaolo Bonzini } 5152c50d8ae3SPaolo Bonzini 5153c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5154c50d8ae3SPaolo Bonzini { 51550c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 51560c1c92f1SPaolo Bonzini 51570c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5158b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 51590c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5160b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 51616d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5162c50d8ae3SPaolo Bonzini } 5163c50d8ae3SPaolo Bonzini 5164527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5165527d5cd7SSean Christopherson { 5166527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5167527d5cd7SSean Christopherson 5168527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5169527d5cd7SSean Christopherson return false; 5170527d5cd7SSean Christopherson 5171527d5cd7SSean Christopherson /* 5172527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5173527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5174527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5175527d5cd7SSean Christopherson * such false positives are relatively rare: 5176527d5cd7SSean Christopherson * 5177527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5178527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5179527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5180527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5181527d5cd7SSean Christopherson */ 5182527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5183527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5184527d5cd7SSean Christopherson } 5185527d5cd7SSean Christopherson 5186527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5187527d5cd7SSean Christopherson { 5188527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5189527d5cd7SSean Christopherson int i; 5190527d5cd7SSean Christopherson 5191527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5192527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5193527d5cd7SSean Christopherson 5194527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5195527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5196527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5197527d5cd7SSean Christopherson } 5198527d5cd7SSean Christopherson 5199527d5cd7SSean Christopherson if (roots_to_free) 5200527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5201527d5cd7SSean Christopherson } 5202527d5cd7SSean Christopherson 5203527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5204527d5cd7SSean Christopherson { 5205527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5206527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5207527d5cd7SSean Christopherson } 5208527d5cd7SSean Christopherson 5209c50d8ae3SPaolo Bonzini static bool need_remote_flush(u64 old, u64 new) 5210c50d8ae3SPaolo Bonzini { 5211c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old)) 5212c50d8ae3SPaolo Bonzini return false; 5213c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(new)) 5214c50d8ae3SPaolo Bonzini return true; 5215c50d8ae3SPaolo Bonzini if ((old ^ new) & PT64_BASE_ADDR_MASK) 5216c50d8ae3SPaolo Bonzini return true; 5217c50d8ae3SPaolo Bonzini old ^= shadow_nx_mask; 5218c50d8ae3SPaolo Bonzini new ^= shadow_nx_mask; 5219c50d8ae3SPaolo Bonzini return (old & ~new & PT64_PERM_MASK) != 0; 5220c50d8ae3SPaolo Bonzini } 5221c50d8ae3SPaolo Bonzini 5222c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5223c50d8ae3SPaolo Bonzini int *bytes) 5224c50d8ae3SPaolo Bonzini { 5225c50d8ae3SPaolo Bonzini u64 gentry = 0; 5226c50d8ae3SPaolo Bonzini int r; 5227c50d8ae3SPaolo Bonzini 5228c50d8ae3SPaolo Bonzini /* 5229c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5230c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5231c50d8ae3SPaolo Bonzini * when they have the same mode. 5232c50d8ae3SPaolo Bonzini */ 5233c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5234c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5235c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5236c50d8ae3SPaolo Bonzini *bytes = 8; 5237c50d8ae3SPaolo Bonzini } 5238c50d8ae3SPaolo Bonzini 5239c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5240c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5241c50d8ae3SPaolo Bonzini if (r) 5242c50d8ae3SPaolo Bonzini gentry = 0; 5243c50d8ae3SPaolo Bonzini } 5244c50d8ae3SPaolo Bonzini 5245c50d8ae3SPaolo Bonzini return gentry; 5246c50d8ae3SPaolo Bonzini } 5247c50d8ae3SPaolo Bonzini 5248c50d8ae3SPaolo Bonzini /* 5249c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5250c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5251c50d8ae3SPaolo Bonzini */ 5252c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5253c50d8ae3SPaolo Bonzini { 5254c50d8ae3SPaolo Bonzini /* 5255c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5256c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5257c50d8ae3SPaolo Bonzini */ 52583bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5259c50d8ae3SPaolo Bonzini return false; 5260c50d8ae3SPaolo Bonzini 5261c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5262c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5263c50d8ae3SPaolo Bonzini } 5264c50d8ae3SPaolo Bonzini 5265c50d8ae3SPaolo Bonzini /* 5266c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5267c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5268c50d8ae3SPaolo Bonzini */ 5269c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5270c50d8ae3SPaolo Bonzini int bytes) 5271c50d8ae3SPaolo Bonzini { 5272c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5273c50d8ae3SPaolo Bonzini 5274c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5275c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5276c50d8ae3SPaolo Bonzini 5277c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5278bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5279c50d8ae3SPaolo Bonzini 5280c50d8ae3SPaolo Bonzini /* 5281c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5282c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5283c50d8ae3SPaolo Bonzini */ 5284c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5285c50d8ae3SPaolo Bonzini return false; 5286c50d8ae3SPaolo Bonzini 5287c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5288c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5289c50d8ae3SPaolo Bonzini 5290c50d8ae3SPaolo Bonzini return misaligned; 5291c50d8ae3SPaolo Bonzini } 5292c50d8ae3SPaolo Bonzini 5293c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5294c50d8ae3SPaolo Bonzini { 5295c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5296c50d8ae3SPaolo Bonzini u64 *spte; 5297c50d8ae3SPaolo Bonzini int level; 5298c50d8ae3SPaolo Bonzini 5299c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5300c50d8ae3SPaolo Bonzini level = sp->role.level; 5301c50d8ae3SPaolo Bonzini *nspte = 1; 5302bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5303c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5304c50d8ae3SPaolo Bonzini /* 5305c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5306c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5307c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5308c50d8ae3SPaolo Bonzini */ 5309c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5310c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5311c50d8ae3SPaolo Bonzini page_offset <<= 1; 5312c50d8ae3SPaolo Bonzini *nspte = 2; 5313c50d8ae3SPaolo Bonzini } 5314c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5315c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5316c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5317c50d8ae3SPaolo Bonzini return NULL; 5318c50d8ae3SPaolo Bonzini } 5319c50d8ae3SPaolo Bonzini 5320c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5321c50d8ae3SPaolo Bonzini return spte; 5322c50d8ae3SPaolo Bonzini } 5323c50d8ae3SPaolo Bonzini 5324c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5325c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5326c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5327c50d8ae3SPaolo Bonzini { 5328c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5329c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5330c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5331c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5332c50d8ae3SPaolo Bonzini int npte; 533306152b2dSLai Jiangshan bool flush = false; 5334c50d8ae3SPaolo Bonzini 5335c50d8ae3SPaolo Bonzini /* 5336c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5337c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5338c50d8ae3SPaolo Bonzini */ 5339c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5340c50d8ae3SPaolo Bonzini return; 5341c50d8ae3SPaolo Bonzini 5342c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5343c50d8ae3SPaolo Bonzini 5344c50d8ae3SPaolo Bonzini /* 5345c50d8ae3SPaolo Bonzini * No need to care whether allocation memory is successful 5346d9f6e12fSIngo Molnar * or not since pte prefetch is skipped if it does not have 5347c50d8ae3SPaolo Bonzini * enough objects in the cache. 5348c50d8ae3SPaolo Bonzini */ 5349378f5cd6SSean Christopherson mmu_topup_memory_caches(vcpu, true); 5350c50d8ae3SPaolo Bonzini 5351531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5352c50d8ae3SPaolo Bonzini 5353c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5354c50d8ae3SPaolo Bonzini 5355c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5356c50d8ae3SPaolo Bonzini 5357c50d8ae3SPaolo Bonzini for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) { 5358c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5359c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5360c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5361c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5362c50d8ae3SPaolo Bonzini continue; 5363c50d8ae3SPaolo Bonzini } 5364c50d8ae3SPaolo Bonzini 5365c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5366c50d8ae3SPaolo Bonzini if (!spte) 5367c50d8ae3SPaolo Bonzini continue; 5368c50d8ae3SPaolo Bonzini 5369c50d8ae3SPaolo Bonzini while (npte--) { 5370c50d8ae3SPaolo Bonzini entry = *spte; 53712de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5372c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5373c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 5374c50d8ae3SPaolo Bonzini if (need_remote_flush(entry, *spte)) 537506152b2dSLai Jiangshan flush = true; 5376c50d8ae3SPaolo Bonzini ++spte; 5377c50d8ae3SPaolo Bonzini } 5378c50d8ae3SPaolo Bonzini } 537906152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5380531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5381c50d8ae3SPaolo Bonzini } 5382c50d8ae3SPaolo Bonzini 5383736c291cSSean Christopherson int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5384c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5385c50d8ae3SPaolo Bonzini { 538692daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5387c50d8ae3SPaolo Bonzini bool direct = vcpu->arch.mmu->direct_map; 5388c50d8ae3SPaolo Bonzini 5389b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5390ddce6208SSean Christopherson return RET_PF_RETRY; 5391ddce6208SSean Christopherson 5392c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5393c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5394736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5395c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5396c50d8ae3SPaolo Bonzini goto emulate; 5397c50d8ae3SPaolo Bonzini } 5398c50d8ae3SPaolo Bonzini 5399c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 54007a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 54017a02674dSSean Christopherson lower_32_bits(error_code), false); 540219025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 54037b367bc9SSean Christopherson return -EIO; 5404c50d8ae3SPaolo Bonzini } 5405c50d8ae3SPaolo Bonzini 5406c50d8ae3SPaolo Bonzini if (r < 0) 5407c50d8ae3SPaolo Bonzini return r; 540883a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 540983a2ba4cSSean Christopherson return 1; 5410c50d8ae3SPaolo Bonzini 5411c50d8ae3SPaolo Bonzini /* 5412c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5413c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5414c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5415c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5416c50d8ae3SPaolo Bonzini * and resume the guest. 5417c50d8ae3SPaolo Bonzini */ 5418c50d8ae3SPaolo Bonzini if (vcpu->arch.mmu->direct_map && 5419c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5420736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5421c50d8ae3SPaolo Bonzini return 1; 5422c50d8ae3SPaolo Bonzini } 5423c50d8ae3SPaolo Bonzini 5424c50d8ae3SPaolo Bonzini /* 5425c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5426c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5427c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5428c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5429c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5430c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5431c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5432c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5433c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5434c50d8ae3SPaolo Bonzini */ 5435736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 543692daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5437c50d8ae3SPaolo Bonzini emulate: 5438736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5439c50d8ae3SPaolo Bonzini insn_len); 5440c50d8ae3SPaolo Bonzini } 5441c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5442c50d8ae3SPaolo Bonzini 54435efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 54445efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5445c50d8ae3SPaolo Bonzini { 5446c50d8ae3SPaolo Bonzini int i; 5447c50d8ae3SPaolo Bonzini 54485efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 54495efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 54505efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5451c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5452c50d8ae3SPaolo Bonzini return; 5453c50d8ae3SPaolo Bonzini 5454e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 54555efac074SPaolo Bonzini } 54565efac074SPaolo Bonzini 54575efac074SPaolo Bonzini if (!mmu->invlpg) 54585efac074SPaolo Bonzini return; 54595efac074SPaolo Bonzini 54605efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5461b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5462c50d8ae3SPaolo Bonzini 5463c50d8ae3SPaolo Bonzini /* 5464c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5465c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5466c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5467c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5468c50d8ae3SPaolo Bonzini * just always sync it. 5469c50d8ae3SPaolo Bonzini * 5470c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5471c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5472c50d8ae3SPaolo Bonzini * for them. 5473c50d8ae3SPaolo Bonzini */ 5474c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5475c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5476c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 54775efac074SPaolo Bonzini } else { 54785efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 54795efac074SPaolo Bonzini } 54805efac074SPaolo Bonzini } 5481c50d8ae3SPaolo Bonzini 54825efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 54835efac074SPaolo Bonzini { 548405b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5485c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5486c50d8ae3SPaolo Bonzini } 5487c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5488c50d8ae3SPaolo Bonzini 54895efac074SPaolo Bonzini 5490c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5491c50d8ae3SPaolo Bonzini { 5492c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5493c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5494c50d8ae3SPaolo Bonzini uint i; 5495c50d8ae3SPaolo Bonzini 5496c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 5497b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5498c50d8ae3SPaolo Bonzini tlb_flush = true; 5499c50d8ae3SPaolo Bonzini } 5500c50d8ae3SPaolo Bonzini 5501c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5502c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5503be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 5504c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5505c50d8ae3SPaolo Bonzini tlb_flush = true; 5506c50d8ae3SPaolo Bonzini } 5507c50d8ae3SPaolo Bonzini } 5508c50d8ae3SPaolo Bonzini 5509c50d8ae3SPaolo Bonzini if (tlb_flush) 5510e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5511c50d8ae3SPaolo Bonzini 5512c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5513c50d8ae3SPaolo Bonzini 5514c50d8ae3SPaolo Bonzini /* 5515c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5516c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5517c50d8ae3SPaolo Bonzini * for them. 5518c50d8ae3SPaolo Bonzini */ 5519c50d8ae3SPaolo Bonzini } 5520c50d8ae3SPaolo Bonzini 5521746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5522746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5523c50d8ae3SPaolo Bonzini { 5524bde77235SSean Christopherson tdp_enabled = enable_tdp; 5525746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 552683013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5527703c335dSSean Christopherson 5528703c335dSSean Christopherson /* 55291d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5530703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5531703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5532703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5533703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5534703c335dSSean Christopherson */ 5535703c335dSSean Christopherson if (tdp_enabled) 55361d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5537703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 55381d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5539703c335dSSean Christopherson else 55401d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5541c50d8ae3SPaolo Bonzini } 5542bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5543c50d8ae3SPaolo Bonzini 5544c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5545269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5546269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5547269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5548c50d8ae3SPaolo Bonzini 5549c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5550c50d8ae3SPaolo Bonzini static __always_inline bool 5551269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5552c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 55531a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 55541a61b7dbSSean Christopherson bool flush) 5555c50d8ae3SPaolo Bonzini { 5556c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5557c50d8ae3SPaolo Bonzini 5558c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5559c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5560c50d8ae3SPaolo Bonzini if (iterator.rmap) 55610a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5562c50d8ae3SPaolo Bonzini 5563531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5564302695a5SSean Christopherson if (flush && flush_on_yield) { 5565c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5566c50d8ae3SPaolo Bonzini start_gfn, 5567c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5568c50d8ae3SPaolo Bonzini flush = false; 5569c50d8ae3SPaolo Bonzini } 5570531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5571c50d8ae3SPaolo Bonzini } 5572c50d8ae3SPaolo Bonzini } 5573c50d8ae3SPaolo Bonzini 5574c50d8ae3SPaolo Bonzini return flush; 5575c50d8ae3SPaolo Bonzini } 5576c50d8ae3SPaolo Bonzini 5577c50d8ae3SPaolo Bonzini static __always_inline bool 5578269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5579c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5580302695a5SSean Christopherson bool flush_on_yield) 5581c50d8ae3SPaolo Bonzini { 5582c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5583c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5584c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 55851a61b7dbSSean Christopherson flush_on_yield, false); 5586c50d8ae3SPaolo Bonzini } 5587c50d8ae3SPaolo Bonzini 5588c50d8ae3SPaolo Bonzini static __always_inline bool 5589610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5590302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5591c50d8ae3SPaolo Bonzini { 55923bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5593302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5594c50d8ae3SPaolo Bonzini } 5595c50d8ae3SPaolo Bonzini 5596c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5597c50d8ae3SPaolo Bonzini { 55984a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 55994a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5600c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 560103ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5602cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5603c50d8ae3SPaolo Bonzini } 5604c50d8ae3SPaolo Bonzini 560504d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5606c50d8ae3SPaolo Bonzini { 5607c50d8ae3SPaolo Bonzini struct page *page; 5608c50d8ae3SPaolo Bonzini int i; 5609c50d8ae3SPaolo Bonzini 5610b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5611b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 561204d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 561304d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 561404d28e37SSean Christopherson 561527f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 561627f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 561727f4fca2SLai Jiangshan return 0; 561827f4fca2SLai Jiangshan 5619c50d8ae3SPaolo Bonzini /* 5620c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5621c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5622c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5623c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 562404d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 562504d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 562604d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 562704d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 562884432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5629c50d8ae3SPaolo Bonzini */ 5630d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5631c50d8ae3SPaolo Bonzini return 0; 5632c50d8ae3SPaolo Bonzini 5633c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5634c50d8ae3SPaolo Bonzini if (!page) 5635c50d8ae3SPaolo Bonzini return -ENOMEM; 5636c50d8ae3SPaolo Bonzini 5637c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 56384a98623dSSean Christopherson 56394a98623dSSean Christopherson /* 56404a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 56414a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 56424a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 56434a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 56444a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 56454a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 56464a98623dSSean Christopherson */ 56474a98623dSSean Christopherson if (!tdp_enabled) 56484a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 56494a98623dSSean Christopherson else 56504a98623dSSean Christopherson WARN_ON_ONCE(shadow_me_mask); 56514a98623dSSean Christopherson 5652c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5653c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5654c50d8ae3SPaolo Bonzini 5655c50d8ae3SPaolo Bonzini return 0; 5656c50d8ae3SPaolo Bonzini } 5657c50d8ae3SPaolo Bonzini 5658c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5659c50d8ae3SPaolo Bonzini { 5660c50d8ae3SPaolo Bonzini int ret; 5661c50d8ae3SPaolo Bonzini 56625962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 56635f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 56645f6078f9SSean Christopherson 56655962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 56665f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 56675962bfb7SSean Christopherson 566896880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 566996880883SSean Christopherson 5670c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5671c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5672c50d8ae3SPaolo Bonzini 567304d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5674c50d8ae3SPaolo Bonzini if (ret) 5675c50d8ae3SPaolo Bonzini return ret; 5676c50d8ae3SPaolo Bonzini 567704d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5678c50d8ae3SPaolo Bonzini if (ret) 5679c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5680c50d8ae3SPaolo Bonzini 5681c50d8ae3SPaolo Bonzini return ret; 5682c50d8ae3SPaolo Bonzini fail_allocate_root: 5683c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5684c50d8ae3SPaolo Bonzini return ret; 5685c50d8ae3SPaolo Bonzini } 5686c50d8ae3SPaolo Bonzini 5687c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5688c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5689c50d8ae3SPaolo Bonzini { 5690c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5691c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5692c50d8ae3SPaolo Bonzini 5693c50d8ae3SPaolo Bonzini restart: 5694c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5695c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5696c50d8ae3SPaolo Bonzini /* 5697c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5698c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5699c50d8ae3SPaolo Bonzini */ 5700c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5701c50d8ae3SPaolo Bonzini break; 5702c50d8ae3SPaolo Bonzini 5703c50d8ae3SPaolo Bonzini /* 5704f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5705f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5706f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5707c50d8ae3SPaolo Bonzini */ 5708f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5709c50d8ae3SPaolo Bonzini continue; 5710c50d8ae3SPaolo Bonzini 5711c50d8ae3SPaolo Bonzini /* 5712c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5713c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5714c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5715c50d8ae3SPaolo Bonzini * be in active use by the guest. 5716c50d8ae3SPaolo Bonzini */ 5717c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5718531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5719c50d8ae3SPaolo Bonzini batch = 0; 5720c50d8ae3SPaolo Bonzini goto restart; 5721c50d8ae3SPaolo Bonzini } 5722c50d8ae3SPaolo Bonzini 5723c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, 5724c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages, &nr_zapped)) { 5725c50d8ae3SPaolo Bonzini batch += nr_zapped; 5726c50d8ae3SPaolo Bonzini goto restart; 5727c50d8ae3SPaolo Bonzini } 5728c50d8ae3SPaolo Bonzini } 5729c50d8ae3SPaolo Bonzini 5730c50d8ae3SPaolo Bonzini /* 57317ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 57327ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 57337ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 57347ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 57357ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 57367ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 57377ae5840eSSean Christopherson * running with an obsolete MMU. 5738c50d8ae3SPaolo Bonzini */ 5739c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5740c50d8ae3SPaolo Bonzini } 5741c50d8ae3SPaolo Bonzini 5742c50d8ae3SPaolo Bonzini /* 5743c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5744c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5745c50d8ae3SPaolo Bonzini * 5746c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5747c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5748c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5749c50d8ae3SPaolo Bonzini * after calling the function. 5750c50d8ae3SPaolo Bonzini */ 5751c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5752c50d8ae3SPaolo Bonzini { 5753c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5754c50d8ae3SPaolo Bonzini 5755531810caSBen Gardon write_lock(&kvm->mmu_lock); 5756c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5757c50d8ae3SPaolo Bonzini 5758c50d8ae3SPaolo Bonzini /* 5759c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5760c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5761c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5762c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5763c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5764c50d8ae3SPaolo Bonzini */ 5765c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5766c50d8ae3SPaolo Bonzini 57672f6f66ccSSean Christopherson /* 57682f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 57692f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 57702f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 57712f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5772b7cccd39SBen Gardon */ 5773b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5774b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5775b7cccd39SBen Gardon 5776c50d8ae3SPaolo Bonzini /* 5777c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5778c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5779c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5780c50d8ae3SPaolo Bonzini * 5781c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5782c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5783c50d8ae3SPaolo Bonzini */ 5784527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5785c50d8ae3SPaolo Bonzini 5786c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5787faaf05b0SBen Gardon 5788531810caSBen Gardon write_unlock(&kvm->mmu_lock); 57894c6654bdSBen Gardon 5790f28e9c7fSSean Christopherson /* 5791f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5792f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5793f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5794f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5795f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5796f28e9c7fSSean Christopherson * lead to use-after-free. 5797f28e9c7fSSean Christopherson */ 579822b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 57994c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5800c50d8ae3SPaolo Bonzini } 5801c50d8ae3SPaolo Bonzini 5802c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5803c50d8ae3SPaolo Bonzini { 5804c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5805c50d8ae3SPaolo Bonzini } 5806c50d8ae3SPaolo Bonzini 5807c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5808c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5809c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5810c50d8ae3SPaolo Bonzini { 5811c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5812c50d8ae3SPaolo Bonzini } 5813c50d8ae3SPaolo Bonzini 5814a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5815c50d8ae3SPaolo Bonzini { 5816c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5817a1a39128SPaolo Bonzini int r; 5818c50d8ae3SPaolo Bonzini 5819a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5820a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5821a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5822ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5823ce25681dSSean Christopherson 5824a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5825a1a39128SPaolo Bonzini if (r < 0) 5826a1a39128SPaolo Bonzini return r; 5827fe5db27dSBen Gardon 5828c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5829c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5830c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5831a1a39128SPaolo Bonzini return 0; 5832c50d8ae3SPaolo Bonzini } 5833c50d8ae3SPaolo Bonzini 5834c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 5835c50d8ae3SPaolo Bonzini { 5836c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5837c50d8ae3SPaolo Bonzini 5838c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 5839fe5db27dSBen Gardon 5840fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 5841c50d8ae3SPaolo Bonzini } 5842c50d8ae3SPaolo Bonzini 584321fa3246SSean Christopherson static bool __kvm_zap_rmaps(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 584421fa3246SSean Christopherson { 584521fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 584621fa3246SSean Christopherson struct kvm_memslots *slots; 5847f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 584821fa3246SSean Christopherson bool flush = false; 584921fa3246SSean Christopherson gfn_t start, end; 5850f4209439SMaciej S. Szmigiero int i; 585121fa3246SSean Christopherson 585221fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 585321fa3246SSean Christopherson return flush; 585421fa3246SSean Christopherson 585521fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 585621fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 5857f4209439SMaciej S. Szmigiero 5858f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 5859f4209439SMaciej S. Szmigiero memslot = iter.slot; 586021fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 586121fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 5862f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 586321fa3246SSean Christopherson continue; 586421fa3246SSean Christopherson 586521fa3246SSean Christopherson flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, 58666ff94f27SDavid Matlack 586721fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 586821fa3246SSean Christopherson start, end - 1, true, flush); 586921fa3246SSean Christopherson } 587021fa3246SSean Christopherson } 587121fa3246SSean Christopherson 587221fa3246SSean Christopherson return flush; 587321fa3246SSean Christopherson } 587421fa3246SSean Christopherson 587588f58535SMaxim Levitsky /* 587688f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 587788f58535SMaxim Levitsky * (not including it) 587888f58535SMaxim Levitsky */ 5879c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 5880c50d8ae3SPaolo Bonzini { 588121fa3246SSean Christopherson bool flush; 5882c50d8ae3SPaolo Bonzini int i; 5883c50d8ae3SPaolo Bonzini 5884f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 5885f4209439SMaciej S. Szmigiero return; 5886f4209439SMaciej S. Szmigiero 5887531810caSBen Gardon write_lock(&kvm->mmu_lock); 58885a324c24SSean Christopherson 5889edb298c6SMaxim Levitsky kvm_inc_notifier_count(kvm, gfn_start, gfn_end); 5890edb298c6SMaxim Levitsky 589121fa3246SSean Christopherson flush = __kvm_zap_rmaps(kvm, gfn_start, gfn_end); 58926103bc07SBen Gardon 58936103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 58946103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 5895f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 5896f47e5bbbSSean Christopherson gfn_end, true, flush); 58976103bc07SBen Gardon } 58985a324c24SSean Christopherson 58995a324c24SSean Christopherson if (flush) 5900bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 5901bc3b3c10SSean Christopherson gfn_end - gfn_start); 59025a324c24SSean Christopherson 5903edb298c6SMaxim Levitsky kvm_dec_notifier_count(kvm, gfn_start, gfn_end); 5904edb298c6SMaxim Levitsky 59055a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 5906c50d8ae3SPaolo Bonzini } 5907c50d8ae3SPaolo Bonzini 5908c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 59090a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 5910269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5911c50d8ae3SPaolo Bonzini { 59121346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 5913c50d8ae3SPaolo Bonzini } 5914c50d8ae3SPaolo Bonzini 5915c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 5916269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 59173c9bd400SJay Zhou int start_level) 5918c50d8ae3SPaolo Bonzini { 5919e2209710SBen Gardon bool flush = false; 5920c50d8ae3SPaolo Bonzini 5921e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 5922531810caSBen Gardon write_lock(&kvm->mmu_lock); 59233c9bd400SJay Zhou flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, 5924e2209710SBen Gardon start_level, KVM_MAX_HUGEPAGE_LEVEL, 5925e2209710SBen Gardon false); 5926531810caSBen Gardon write_unlock(&kvm->mmu_lock); 5927e2209710SBen Gardon } 5928c50d8ae3SPaolo Bonzini 592924ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 593024ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 593124ae4cfaSBen Gardon flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 593224ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 593324ae4cfaSBen Gardon } 593424ae4cfaSBen Gardon 5935c50d8ae3SPaolo Bonzini /* 59366ff94f27SDavid Matlack * Flush TLBs if any SPTEs had to be write-protected to ensure that 59376ff94f27SDavid Matlack * guest writes are reflected in the dirty bitmap before the memslot 59386ff94f27SDavid Matlack * update completes, i.e. before enabling dirty logging is visible to 59396ff94f27SDavid Matlack * userspace. 59406ff94f27SDavid Matlack * 59416ff94f27SDavid Matlack * Perform the TLB flush outside the mmu_lock to reduce the amount of 59426ff94f27SDavid Matlack * time the lock is held. However, this does mean that another CPU can 59436ff94f27SDavid Matlack * now grab mmu_lock and encounter a write-protected SPTE while CPUs 59446ff94f27SDavid Matlack * still have a writable mapping for the associated GFN in their TLB. 59456ff94f27SDavid Matlack * 59466ff94f27SDavid Matlack * This is safe but requires KVM to be careful when making decisions 59476ff94f27SDavid Matlack * based on the write-protection status of an SPTE. Specifically, KVM 59486ff94f27SDavid Matlack * also write-protects SPTEs to monitor changes to guest page tables 59496ff94f27SDavid Matlack * during shadow paging, and must guarantee no CPUs can write to those 59506ff94f27SDavid Matlack * page before the lock is dropped. As mentioned in the previous 59516ff94f27SDavid Matlack * paragraph, a write-protected SPTE is no guarantee that CPU cannot 59526ff94f27SDavid Matlack * perform writes. So to determine if a TLB flush is truly required, KVM 59536ff94f27SDavid Matlack * will clear a separate software-only bit (MMU-writable) and skip the 59546ff94f27SDavid Matlack * flush if-and-only-if this bit was already clear. 59556ff94f27SDavid Matlack * 595602844ac1SDavid Matlack * See is_writable_pte() for more details. 5957c50d8ae3SPaolo Bonzini */ 5958c50d8ae3SPaolo Bonzini if (flush) 59597f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 5960c50d8ae3SPaolo Bonzini } 5961c50d8ae3SPaolo Bonzini 5962cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 5963cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 5964cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 5965cb00a70bSDavid Matlack u64 start, u64 end, 5966cb00a70bSDavid Matlack int target_level) 5967cb00a70bSDavid Matlack { 5968cb00a70bSDavid Matlack if (is_tdp_mmu_enabled(kvm)) 5969cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, 5970cb00a70bSDavid Matlack target_level, false); 5971cb00a70bSDavid Matlack 5972cb00a70bSDavid Matlack /* 5973cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 5974cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 5975cb00a70bSDavid Matlack */ 5976cb00a70bSDavid Matlack } 5977cb00a70bSDavid Matlack 5978a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 5979a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 5980a3fe5dbdSDavid Matlack int target_level) 5981a3fe5dbdSDavid Matlack { 5982a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 5983a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 5984a3fe5dbdSDavid Matlack 5985a3fe5dbdSDavid Matlack if (is_tdp_mmu_enabled(kvm)) { 5986a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 5987cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 5988a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 5989a3fe5dbdSDavid Matlack } 5990a3fe5dbdSDavid Matlack 5991a3fe5dbdSDavid Matlack /* 5992a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 5993a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 5994a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 5995a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 5996a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 5997a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 5998a3fe5dbdSDavid Matlack * SPTEs. 5999a3fe5dbdSDavid Matlack */ 6000a3fe5dbdSDavid Matlack } 6001a3fe5dbdSDavid Matlack 6002c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 60030a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6004269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6005c50d8ae3SPaolo Bonzini { 6006c50d8ae3SPaolo Bonzini u64 *sptep; 6007c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6008c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6009c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 6010c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6011c50d8ae3SPaolo Bonzini 6012c50d8ae3SPaolo Bonzini restart: 6013c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 601457354682SSean Christopherson sp = sptep_to_sp(sptep); 6015c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(*sptep); 6016c50d8ae3SPaolo Bonzini 6017c50d8ae3SPaolo Bonzini /* 6018c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6019c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6020c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6021c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6022c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6023c50d8ae3SPaolo Bonzini */ 6024c50d8ae3SPaolo Bonzini if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && 60259eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 60269eba50f8SSean Christopherson pfn, PG_LEVEL_NUM)) { 602771f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 6028c50d8ae3SPaolo Bonzini 6029c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6030c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6031c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6032c50d8ae3SPaolo Bonzini else 6033c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6034c50d8ae3SPaolo Bonzini 6035c50d8ae3SPaolo Bonzini goto restart; 6036c50d8ae3SPaolo Bonzini } 6037c50d8ae3SPaolo Bonzini } 6038c50d8ae3SPaolo Bonzini 6039c50d8ae3SPaolo Bonzini return need_tlb_flush; 6040c50d8ae3SPaolo Bonzini } 6041c50d8ae3SPaolo Bonzini 6042c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6043269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6044c50d8ae3SPaolo Bonzini { 6045e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6046531810caSBen Gardon write_lock(&kvm->mmu_lock); 6047610265eaSDavid Matlack /* 6048610265eaSDavid Matlack * Zap only 4k SPTEs since the legacy MMU only supports dirty 6049610265eaSDavid Matlack * logging at a 4k granularity and never creates collapsible 6050610265eaSDavid Matlack * 2m SPTEs during dirty logging. 6051610265eaSDavid Matlack */ 60524b85c921SSean Christopherson if (slot_handle_level_4k(kvm, slot, kvm_mmu_zap_collapsible_spte, true)) 6053302695a5SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 6054531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6055e2209710SBen Gardon } 60562db6f772SBen Gardon 60572db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60582db6f772SBen Gardon read_lock(&kvm->mmu_lock); 60594b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 60602db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 60612db6f772SBen Gardon } 6062c50d8ae3SPaolo Bonzini } 6063c50d8ae3SPaolo Bonzini 6064b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 60656c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6066b3594ffbSSean Christopherson { 6067b3594ffbSSean Christopherson /* 60687f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6069302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 60707f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 60717f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 60727f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6073b3594ffbSSean Christopherson */ 6074b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6075cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6076cec37648SSean Christopherson memslot->npages); 6077b3594ffbSSean Christopherson } 6078b3594ffbSSean Christopherson 6079c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6080269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6081c50d8ae3SPaolo Bonzini { 6082e2209710SBen Gardon bool flush = false; 6083c50d8ae3SPaolo Bonzini 6084e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6085531810caSBen Gardon write_lock(&kvm->mmu_lock); 6086610265eaSDavid Matlack /* 6087610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6088610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6089610265eaSDavid Matlack */ 6090610265eaSDavid Matlack flush = slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6091531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6092e2209710SBen Gardon } 6093c50d8ae3SPaolo Bonzini 609424ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 609524ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 609624ae4cfaSBen Gardon flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 609724ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 609824ae4cfaSBen Gardon } 609924ae4cfaSBen Gardon 6100c50d8ae3SPaolo Bonzini /* 6101c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6102c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6103c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6104c50d8ae3SPaolo Bonzini * dirty_bitmap. 6105c50d8ae3SPaolo Bonzini */ 6106c50d8ae3SPaolo Bonzini if (flush) 61077f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6108c50d8ae3SPaolo Bonzini } 6109c50d8ae3SPaolo Bonzini 6110c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6111c50d8ae3SPaolo Bonzini { 6112c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6113c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6114c50d8ae3SPaolo Bonzini int ign; 6115c50d8ae3SPaolo Bonzini 6116531810caSBen Gardon write_lock(&kvm->mmu_lock); 6117c50d8ae3SPaolo Bonzini restart: 6118c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6119f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6120c50d8ae3SPaolo Bonzini continue; 6121c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6122c50d8ae3SPaolo Bonzini goto restart; 6123531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6124c50d8ae3SPaolo Bonzini goto restart; 6125c50d8ae3SPaolo Bonzini } 6126c50d8ae3SPaolo Bonzini 6127c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6128faaf05b0SBen Gardon 6129897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6130faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6131faaf05b0SBen Gardon 6132531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6133c50d8ae3SPaolo Bonzini } 6134c50d8ae3SPaolo Bonzini 6135c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6136c50d8ae3SPaolo Bonzini { 6137c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6138c50d8ae3SPaolo Bonzini 6139c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6140c50d8ae3SPaolo Bonzini 6141c50d8ae3SPaolo Bonzini /* 6142c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6143c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6144c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6145c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6146c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6147c50d8ae3SPaolo Bonzini */ 6148c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6149c50d8ae3SPaolo Bonzini 6150c50d8ae3SPaolo Bonzini /* 6151c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6152c50d8ae3SPaolo Bonzini * zap all shadow pages. 6153c50d8ae3SPaolo Bonzini */ 6154c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6155c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6156c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6157c50d8ae3SPaolo Bonzini } 6158c50d8ae3SPaolo Bonzini } 6159c50d8ae3SPaolo Bonzini 6160c50d8ae3SPaolo Bonzini static unsigned long 6161c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6162c50d8ae3SPaolo Bonzini { 6163c50d8ae3SPaolo Bonzini struct kvm *kvm; 6164c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6165c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6166c50d8ae3SPaolo Bonzini 6167c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6168c50d8ae3SPaolo Bonzini 6169c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6170c50d8ae3SPaolo Bonzini int idx; 6171c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6172c50d8ae3SPaolo Bonzini 6173c50d8ae3SPaolo Bonzini /* 6174c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6175c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6176c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6177c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6178c50d8ae3SPaolo Bonzini */ 6179c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6180c50d8ae3SPaolo Bonzini break; 6181c50d8ae3SPaolo Bonzini /* 6182c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6183c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6184c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6185c50d8ae3SPaolo Bonzini * anyway. 6186c50d8ae3SPaolo Bonzini */ 6187c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6188c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6189c50d8ae3SPaolo Bonzini continue; 6190c50d8ae3SPaolo Bonzini 6191c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6192531810caSBen Gardon write_lock(&kvm->mmu_lock); 6193c50d8ae3SPaolo Bonzini 6194c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6195c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6196c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6197c50d8ae3SPaolo Bonzini goto unlock; 6198c50d8ae3SPaolo Bonzini } 6199c50d8ae3SPaolo Bonzini 6200ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6201c50d8ae3SPaolo Bonzini 6202c50d8ae3SPaolo Bonzini unlock: 6203531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6204c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6205c50d8ae3SPaolo Bonzini 6206c50d8ae3SPaolo Bonzini /* 6207c50d8ae3SPaolo Bonzini * unfair on small ones 6208c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6209c50d8ae3SPaolo Bonzini * sadness comes quickly 6210c50d8ae3SPaolo Bonzini */ 6211c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6212c50d8ae3SPaolo Bonzini break; 6213c50d8ae3SPaolo Bonzini } 6214c50d8ae3SPaolo Bonzini 6215c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6216c50d8ae3SPaolo Bonzini return freed; 6217c50d8ae3SPaolo Bonzini } 6218c50d8ae3SPaolo Bonzini 6219c50d8ae3SPaolo Bonzini static unsigned long 6220c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6221c50d8ae3SPaolo Bonzini { 6222c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6223c50d8ae3SPaolo Bonzini } 6224c50d8ae3SPaolo Bonzini 6225c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6226c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6227c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6228c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6229c50d8ae3SPaolo Bonzini }; 6230c50d8ae3SPaolo Bonzini 6231c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6232c50d8ae3SPaolo Bonzini { 6233c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6234c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6235c50d8ae3SPaolo Bonzini } 6236c50d8ae3SPaolo Bonzini 6237c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6238c50d8ae3SPaolo Bonzini { 6239c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6240c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6241c50d8ae3SPaolo Bonzini } 6242c50d8ae3SPaolo Bonzini 6243c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6244c50d8ae3SPaolo Bonzini { 6245c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6246c50d8ae3SPaolo Bonzini } 6247c50d8ae3SPaolo Bonzini 6248c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6249c50d8ae3SPaolo Bonzini { 6250c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6251c50d8ae3SPaolo Bonzini bool new_val; 6252c50d8ae3SPaolo Bonzini 6253c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6254c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6255c50d8ae3SPaolo Bonzini new_val = 0; 6256c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6257c50d8ae3SPaolo Bonzini new_val = 1; 6258c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6259c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6260c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6261c50d8ae3SPaolo Bonzini return -EINVAL; 6262c50d8ae3SPaolo Bonzini 6263c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6264c50d8ae3SPaolo Bonzini 6265c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6266c50d8ae3SPaolo Bonzini struct kvm *kvm; 6267c50d8ae3SPaolo Bonzini 6268c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6269c50d8ae3SPaolo Bonzini 6270c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6271c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6272c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6273c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6274c50d8ae3SPaolo Bonzini 6275c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6276c50d8ae3SPaolo Bonzini } 6277c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6278c50d8ae3SPaolo Bonzini } 6279c50d8ae3SPaolo Bonzini 6280c50d8ae3SPaolo Bonzini return 0; 6281c50d8ae3SPaolo Bonzini } 6282c50d8ae3SPaolo Bonzini 62831d0e8480SSean Christopherson /* 62841d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 62851d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 62861d0e8480SSean Christopherson */ 62871d0e8480SSean Christopherson void kvm_mmu_x86_module_init(void) 6288c50d8ae3SPaolo Bonzini { 6289c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6290c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 62911d0e8480SSean Christopherson } 62921d0e8480SSean Christopherson 62931d0e8480SSean Christopherson /* 62941d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 62951d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 62961d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 62971d0e8480SSean Christopherson */ 62981d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 62991d0e8480SSean Christopherson { 63001d0e8480SSean Christopherson int ret = -ENOMEM; 6301c50d8ae3SPaolo Bonzini 6302c50d8ae3SPaolo Bonzini /* 6303c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6304c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6305c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6306c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6307c50d8ae3SPaolo Bonzini */ 6308c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6309c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 6310c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_role) != sizeof(u64)); 6311c50d8ae3SPaolo Bonzini 6312c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6313c50d8ae3SPaolo Bonzini 6314c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6315c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6316c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6317c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6318c50d8ae3SPaolo Bonzini goto out; 6319c50d8ae3SPaolo Bonzini 6320c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6321c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6322c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6323c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6324c50d8ae3SPaolo Bonzini goto out; 6325c50d8ae3SPaolo Bonzini 6326c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6327c50d8ae3SPaolo Bonzini goto out; 6328c50d8ae3SPaolo Bonzini 6329c50d8ae3SPaolo Bonzini ret = register_shrinker(&mmu_shrinker); 6330c50d8ae3SPaolo Bonzini if (ret) 6331c50d8ae3SPaolo Bonzini goto out; 6332c50d8ae3SPaolo Bonzini 6333c50d8ae3SPaolo Bonzini return 0; 6334c50d8ae3SPaolo Bonzini 6335c50d8ae3SPaolo Bonzini out: 6336c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6337c50d8ae3SPaolo Bonzini return ret; 6338c50d8ae3SPaolo Bonzini } 6339c50d8ae3SPaolo Bonzini 6340c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6341c50d8ae3SPaolo Bonzini { 6342c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6343c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6344c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6345c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6346c50d8ae3SPaolo Bonzini } 6347c50d8ae3SPaolo Bonzini 63481d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6349c50d8ae3SPaolo Bonzini { 6350c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6351c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6352c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6353c50d8ae3SPaolo Bonzini } 6354c50d8ae3SPaolo Bonzini 6355f47491d7SSean Christopherson /* 6356f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6357f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6358f47491d7SSean Christopherson */ 6359f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6360f47491d7SSean Christopherson { 6361f47491d7SSean Christopherson /* 6362f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6363f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6364f47491d7SSean Christopherson */ 6365f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6366f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6367f47491d7SSean Christopherson 6368f47491d7SSean Christopherson if (!enabled || !ratio) 6369f47491d7SSean Christopherson return false; 6370f47491d7SSean Christopherson 6371f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6372f47491d7SSean Christopherson if (!*period) { 6373f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6374f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6375f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6376f47491d7SSean Christopherson } 6377f47491d7SSean Christopherson return true; 6378f47491d7SSean Christopherson } 6379f47491d7SSean Christopherson 63804dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6381c50d8ae3SPaolo Bonzini { 63824dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 63834dfe4f40SJunaid Shahid uint old_period, new_period; 6384c50d8ae3SPaolo Bonzini int err; 6385c50d8ae3SPaolo Bonzini 6386f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 63874dfe4f40SJunaid Shahid 6388c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6389c50d8ae3SPaolo Bonzini if (err) 6390c50d8ae3SPaolo Bonzini return err; 6391c50d8ae3SPaolo Bonzini 6392f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 63934dfe4f40SJunaid Shahid 6394f47491d7SSean Christopherson if (is_recovery_enabled && 63954dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6396c50d8ae3SPaolo Bonzini struct kvm *kvm; 6397c50d8ae3SPaolo Bonzini 6398c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6399c50d8ae3SPaolo Bonzini 6400c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6401c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6402c50d8ae3SPaolo Bonzini 6403c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6404c50d8ae3SPaolo Bonzini } 6405c50d8ae3SPaolo Bonzini 6406c50d8ae3SPaolo Bonzini return err; 6407c50d8ae3SPaolo Bonzini } 6408c50d8ae3SPaolo Bonzini 6409c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6410c50d8ae3SPaolo Bonzini { 6411ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6412c50d8ae3SPaolo Bonzini int rcu_idx; 6413c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6414c50d8ae3SPaolo Bonzini unsigned int ratio; 6415c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6416048f4980SSean Christopherson bool flush = false; 6417c50d8ae3SPaolo Bonzini ulong to_zap; 6418c50d8ae3SPaolo Bonzini 6419c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6420531810caSBen Gardon write_lock(&kvm->mmu_lock); 6421c50d8ae3SPaolo Bonzini 6422bb95dfb9SSean Christopherson /* 6423bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6424bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6425bb95dfb9SSean Christopherson * callback. 6426bb95dfb9SSean Christopherson */ 6427bb95dfb9SSean Christopherson rcu_read_lock(); 6428bb95dfb9SSean Christopherson 6429c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6430ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 64317d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 64327d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 64337d919c7aSSean Christopherson break; 64347d919c7aSSean Christopherson 6435c50d8ae3SPaolo Bonzini /* 6436c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6437c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6438c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6439c50d8ae3SPaolo Bonzini */ 6440c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6441c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6442c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6443c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6444897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6445315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 64468d1a182eSBen Gardon } else { 6447c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6448c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 644929cf0f50SBen Gardon } 6450c50d8ae3SPaolo Bonzini 6451531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6452048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6453bb95dfb9SSean Christopherson rcu_read_unlock(); 6454bb95dfb9SSean Christopherson 6455531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6456048f4980SSean Christopherson flush = false; 6457bb95dfb9SSean Christopherson 6458bb95dfb9SSean Christopherson rcu_read_lock(); 6459c50d8ae3SPaolo Bonzini } 6460c50d8ae3SPaolo Bonzini } 6461048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6462c50d8ae3SPaolo Bonzini 6463bb95dfb9SSean Christopherson rcu_read_unlock(); 6464bb95dfb9SSean Christopherson 6465531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6466c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6467c50d8ae3SPaolo Bonzini } 6468c50d8ae3SPaolo Bonzini 6469c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6470c50d8ae3SPaolo Bonzini { 6471f47491d7SSean Christopherson bool enabled; 6472f47491d7SSean Christopherson uint period; 64734dfe4f40SJunaid Shahid 6474f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 64754dfe4f40SJunaid Shahid 6476f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6477c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6478c50d8ae3SPaolo Bonzini } 6479c50d8ae3SPaolo Bonzini 6480c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6481c50d8ae3SPaolo Bonzini { 6482c50d8ae3SPaolo Bonzini u64 start_time; 6483c50d8ae3SPaolo Bonzini long remaining_time; 6484c50d8ae3SPaolo Bonzini 6485c50d8ae3SPaolo Bonzini while (true) { 6486c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6487c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6488c50d8ae3SPaolo Bonzini 6489c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6490c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6491c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6492c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6493c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6494c50d8ae3SPaolo Bonzini } 6495c50d8ae3SPaolo Bonzini 6496c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6497c50d8ae3SPaolo Bonzini 6498c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6499c50d8ae3SPaolo Bonzini return 0; 6500c50d8ae3SPaolo Bonzini 6501c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6502c50d8ae3SPaolo Bonzini } 6503c50d8ae3SPaolo Bonzini } 6504c50d8ae3SPaolo Bonzini 6505c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6506c50d8ae3SPaolo Bonzini { 6507c50d8ae3SPaolo Bonzini int err; 6508c50d8ae3SPaolo Bonzini 6509c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6510c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6511c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6512c50d8ae3SPaolo Bonzini if (!err) 6513c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6514c50d8ae3SPaolo Bonzini 6515c50d8ae3SPaolo Bonzini return err; 6516c50d8ae3SPaolo Bonzini } 6517c50d8ae3SPaolo Bonzini 6518c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6519c50d8ae3SPaolo Bonzini { 6520c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6521c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6522c50d8ae3SPaolo Bonzini } 6523