1c50d8ae3SPaolo Bonzini // SPDX-License-Identifier: GPL-2.0-only 2c50d8ae3SPaolo Bonzini /* 3c50d8ae3SPaolo Bonzini * Kernel-based Virtual Machine driver for Linux 4c50d8ae3SPaolo Bonzini * 5c50d8ae3SPaolo Bonzini * This module enables machines with Intel VT-x extensions to run virtual 6c50d8ae3SPaolo Bonzini * machines without emulation or binary translation. 7c50d8ae3SPaolo Bonzini * 8c50d8ae3SPaolo Bonzini * MMU support 9c50d8ae3SPaolo Bonzini * 10c50d8ae3SPaolo Bonzini * Copyright (C) 2006 Qumranet, Inc. 11c50d8ae3SPaolo Bonzini * Copyright 2010 Red Hat, Inc. and/or its affiliates. 12c50d8ae3SPaolo Bonzini * 13c50d8ae3SPaolo Bonzini * Authors: 14c50d8ae3SPaolo Bonzini * Yaniv Kamay <yaniv@qumranet.com> 15c50d8ae3SPaolo Bonzini * Avi Kivity <avi@qumranet.com> 16c50d8ae3SPaolo Bonzini */ 17c50d8ae3SPaolo Bonzini 18c50d8ae3SPaolo Bonzini #include "irq.h" 1988197e6aS彭浩(Richard) #include "ioapic.h" 20c50d8ae3SPaolo Bonzini #include "mmu.h" 216ca9a6f3SSean Christopherson #include "mmu_internal.h" 22fe5db27dSBen Gardon #include "tdp_mmu.h" 23c50d8ae3SPaolo Bonzini #include "x86.h" 24c50d8ae3SPaolo Bonzini #include "kvm_cache_regs.h" 252f728d66SSean Christopherson #include "kvm_emulate.h" 26c50d8ae3SPaolo Bonzini #include "cpuid.h" 275a9624afSPaolo Bonzini #include "spte.h" 28c50d8ae3SPaolo Bonzini 29c50d8ae3SPaolo Bonzini #include <linux/kvm_host.h> 30c50d8ae3SPaolo Bonzini #include <linux/types.h> 31c50d8ae3SPaolo Bonzini #include <linux/string.h> 32c50d8ae3SPaolo Bonzini #include <linux/mm.h> 33c50d8ae3SPaolo Bonzini #include <linux/highmem.h> 34c50d8ae3SPaolo Bonzini #include <linux/moduleparam.h> 35c50d8ae3SPaolo Bonzini #include <linux/export.h> 36c50d8ae3SPaolo Bonzini #include <linux/swap.h> 37c50d8ae3SPaolo Bonzini #include <linux/hugetlb.h> 38c50d8ae3SPaolo Bonzini #include <linux/compiler.h> 39c50d8ae3SPaolo Bonzini #include <linux/srcu.h> 40c50d8ae3SPaolo Bonzini #include <linux/slab.h> 41c50d8ae3SPaolo Bonzini #include <linux/sched/signal.h> 42c50d8ae3SPaolo Bonzini #include <linux/uaccess.h> 43c50d8ae3SPaolo Bonzini #include <linux/hash.h> 44c50d8ae3SPaolo Bonzini #include <linux/kern_levels.h> 45c50d8ae3SPaolo Bonzini #include <linux/kthread.h> 46c50d8ae3SPaolo Bonzini 47c50d8ae3SPaolo Bonzini #include <asm/page.h> 48eb243d1dSIngo Molnar #include <asm/memtype.h> 49c50d8ae3SPaolo Bonzini #include <asm/cmpxchg.h> 50c50d8ae3SPaolo Bonzini #include <asm/io.h> 514a98623dSSean Christopherson #include <asm/set_memory.h> 52c50d8ae3SPaolo Bonzini #include <asm/vmx.h> 53c50d8ae3SPaolo Bonzini #include <asm/kvm_page_track.h> 54c50d8ae3SPaolo Bonzini #include "trace.h" 55c50d8ae3SPaolo Bonzini 56c50d8ae3SPaolo Bonzini extern bool itlb_multihit_kvm_mitigation; 57c50d8ae3SPaolo Bonzini 58a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 594dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 60c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 61c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 62c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 63c50d8ae3SPaolo Bonzini #else 64c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 65c50d8ae3SPaolo Bonzini #endif 66c50d8ae3SPaolo Bonzini 67c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 684dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 69c50d8ae3SPaolo Bonzini 70d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 71c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 72c50d8ae3SPaolo Bonzini .get = param_get_bool, 73c50d8ae3SPaolo Bonzini }; 74c50d8ae3SPaolo Bonzini 754dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 764dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 77c50d8ae3SPaolo Bonzini .get = param_get_uint, 78c50d8ae3SPaolo Bonzini }; 79c50d8ae3SPaolo Bonzini 80c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 81c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 824dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 83c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 84c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 854dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 864dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 874dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 88c50d8ae3SPaolo Bonzini 8971fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9071fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9171fe7013SSean Christopherson 92c50d8ae3SPaolo Bonzini /* 93c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 94c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 95c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 96c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 97c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 98c50d8ae3SPaolo Bonzini */ 99c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 100c50d8ae3SPaolo Bonzini 1011d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 102746700d2SWei Huang static int tdp_root_level __read_mostly; 10383013059SSean Christopherson static int max_tdp_level __read_mostly; 104703c335dSSean Christopherson 105c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1065a9624afSPaolo Bonzini bool dbg = 0; 107c50d8ae3SPaolo Bonzini module_param(dbg, bool, 0644); 108c50d8ae3SPaolo Bonzini #endif 109c50d8ae3SPaolo Bonzini 110c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 111c50d8ae3SPaolo Bonzini 112c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 113c50d8ae3SPaolo Bonzini 114dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 11513236e25SPeter Xu #define PTE_LIST_EXT 14 116c50d8ae3SPaolo Bonzini 11713236e25SPeter Xu /* 11813236e25SPeter Xu * Slight optimization of cacheline layout, by putting `more' and `spte_count' 11913236e25SPeter Xu * at the start; then accessing it will only use one single cacheline for 12013236e25SPeter Xu * either full (entries==PTE_LIST_EXT) case or entries<=6. 12113236e25SPeter Xu */ 122c50d8ae3SPaolo Bonzini struct pte_list_desc { 123c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 12413236e25SPeter Xu /* 12513236e25SPeter Xu * Stores number of entries stored in the pte_list_desc. No need to be 12613236e25SPeter Xu * u64 but just for easier alignment. When PTE_LIST_EXT, means full. 12713236e25SPeter Xu */ 12813236e25SPeter Xu u64 spte_count; 12913236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 130c50d8ae3SPaolo Bonzini }; 131c50d8ae3SPaolo Bonzini 132c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 133c50d8ae3SPaolo Bonzini u64 addr; 134c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 135c50d8ae3SPaolo Bonzini u64 *sptep; 136c50d8ae3SPaolo Bonzini int level; 137c50d8ae3SPaolo Bonzini unsigned index; 138c50d8ae3SPaolo Bonzini }; 139c50d8ae3SPaolo Bonzini 140c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 141c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 142c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 143c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 144c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 145c50d8ae3SPaolo Bonzini 146c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 147c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 148c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 149c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 150c50d8ae3SPaolo Bonzini 151c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 152c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 153c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 154c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 155c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 156c50d8ae3SPaolo Bonzini 157c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 15802c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 159c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 160c50d8ae3SPaolo Bonzini 161c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 162c50d8ae3SPaolo Bonzini 163594e91a1SSean Christopherson struct kvm_mmu_role_regs { 164594e91a1SSean Christopherson const unsigned long cr0; 165594e91a1SSean Christopherson const unsigned long cr4; 166594e91a1SSean Christopherson const u64 efer; 167594e91a1SSean Christopherson }; 168594e91a1SSean Christopherson 169c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 170c50d8ae3SPaolo Bonzini #include "mmutrace.h" 171c50d8ae3SPaolo Bonzini 172594e91a1SSean Christopherson /* 173594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1747a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 175594e91a1SSean Christopherson * the single source of truth for the MMU's state. 176594e91a1SSean Christopherson */ 177594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 17882ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 17982ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 180594e91a1SSean Christopherson { \ 181594e91a1SSean Christopherson return !!(regs->reg & flag); \ 182594e91a1SSean Christopherson } 183594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 184594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 185594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 186594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 187594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 188594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 189594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 190594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 191594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 192594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 193594e91a1SSean Christopherson 19460667724SSean Christopherson /* 19560667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 19660667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 19760667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 19860667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 19960667724SSean Christopherson */ 20060667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2014ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 20260667724SSean Christopherson { \ 203e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 20460667724SSean Christopherson } 20560667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 20660667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 20760667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 20860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 20960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 21060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 21160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 21256b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 21360667724SSean Christopherson 214faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 215faf72962SPaolo Bonzini { 216faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 217faf72962SPaolo Bonzini } 218faf72962SPaolo Bonzini 219faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 220faf72962SPaolo Bonzini { 221faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 222faf72962SPaolo Bonzini } 223faf72962SPaolo Bonzini 224594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 225594e91a1SSean Christopherson { 226594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 227594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 228594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 229594e91a1SSean Christopherson .efer = vcpu->arch.efer, 230594e91a1SSean Christopherson }; 231594e91a1SSean Christopherson 232594e91a1SSean Christopherson return regs; 233594e91a1SSean Christopherson } 234c50d8ae3SPaolo Bonzini 235c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 236c50d8ae3SPaolo Bonzini { 237afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 238c50d8ae3SPaolo Bonzini } 239c50d8ae3SPaolo Bonzini 240c50d8ae3SPaolo Bonzini static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm, 241c50d8ae3SPaolo Bonzini struct kvm_tlb_range *range) 242c50d8ae3SPaolo Bonzini { 243c50d8ae3SPaolo Bonzini int ret = -ENOTSUPP; 244c50d8ae3SPaolo Bonzini 245afaf0b2fSSean Christopherson if (range && kvm_x86_ops.tlb_remote_flush_with_range) 246b3646477SJason Baron ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range); 247c50d8ae3SPaolo Bonzini 248c50d8ae3SPaolo Bonzini if (ret) 249c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 250c50d8ae3SPaolo Bonzini } 251c50d8ae3SPaolo Bonzini 2522f2fad08SBen Gardon void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 253c50d8ae3SPaolo Bonzini u64 start_gfn, u64 pages) 254c50d8ae3SPaolo Bonzini { 255c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 256c50d8ae3SPaolo Bonzini 257c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 258c50d8ae3SPaolo Bonzini range.pages = pages; 259c50d8ae3SPaolo Bonzini 260c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_range(kvm, &range); 261c50d8ae3SPaolo Bonzini } 262c50d8ae3SPaolo Bonzini 2638f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2648f79b064SBen Gardon unsigned int access) 2658f79b064SBen Gardon { 266c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2678f79b064SBen Gardon 268c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 269c236d962SSean Christopherson mmu_spte_set(sptep, spte); 270c50d8ae3SPaolo Bonzini } 271c50d8ae3SPaolo Bonzini 272c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 273c50d8ae3SPaolo Bonzini { 274c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 275c50d8ae3SPaolo Bonzini 2768a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 277c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 278c50d8ae3SPaolo Bonzini 279c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 280c50d8ae3SPaolo Bonzini } 281c50d8ae3SPaolo Bonzini 282c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 283c50d8ae3SPaolo Bonzini { 284c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 285c50d8ae3SPaolo Bonzini } 286c50d8ae3SPaolo Bonzini 287c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 288c50d8ae3SPaolo Bonzini { 289c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 290c50d8ae3SPaolo Bonzini 291c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 292c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 293c50d8ae3SPaolo Bonzini return false; 294c50d8ae3SPaolo Bonzini 295c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 296c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 297c50d8ae3SPaolo Bonzini 298c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 299c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 300c50d8ae3SPaolo Bonzini } 301c50d8ae3SPaolo Bonzini 302c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 303c50d8ae3SPaolo Bonzini { 304c50d8ae3SPaolo Bonzini return 1; 305c50d8ae3SPaolo Bonzini } 306c50d8ae3SPaolo Bonzini 307c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 308c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 309c50d8ae3SPaolo Bonzini { 310c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 311c50d8ae3SPaolo Bonzini } 312c50d8ae3SPaolo Bonzini 313c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 314c50d8ae3SPaolo Bonzini { 315c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 316c50d8ae3SPaolo Bonzini } 317c50d8ae3SPaolo Bonzini 318c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 319c50d8ae3SPaolo Bonzini { 320c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 321c50d8ae3SPaolo Bonzini } 322c50d8ae3SPaolo Bonzini 323c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 324c50d8ae3SPaolo Bonzini { 325c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 326c50d8ae3SPaolo Bonzini } 327c50d8ae3SPaolo Bonzini #else 328c50d8ae3SPaolo Bonzini union split_spte { 329c50d8ae3SPaolo Bonzini struct { 330c50d8ae3SPaolo Bonzini u32 spte_low; 331c50d8ae3SPaolo Bonzini u32 spte_high; 332c50d8ae3SPaolo Bonzini }; 333c50d8ae3SPaolo Bonzini u64 spte; 334c50d8ae3SPaolo Bonzini }; 335c50d8ae3SPaolo Bonzini 336c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 337c50d8ae3SPaolo Bonzini { 33857354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 339c50d8ae3SPaolo Bonzini 340c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 341c50d8ae3SPaolo Bonzini return; 342c50d8ae3SPaolo Bonzini 343c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 344c50d8ae3SPaolo Bonzini smp_wmb(); 345c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 346c50d8ae3SPaolo Bonzini } 347c50d8ae3SPaolo Bonzini 348c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 349c50d8ae3SPaolo Bonzini { 350c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 351c50d8ae3SPaolo Bonzini 352c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 353c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 354c50d8ae3SPaolo Bonzini 355c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 356c50d8ae3SPaolo Bonzini 357c50d8ae3SPaolo Bonzini /* 358c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 359c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 360c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 361c50d8ae3SPaolo Bonzini */ 362c50d8ae3SPaolo Bonzini smp_wmb(); 363c50d8ae3SPaolo Bonzini 364c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 365c50d8ae3SPaolo Bonzini } 366c50d8ae3SPaolo Bonzini 367c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 368c50d8ae3SPaolo Bonzini { 369c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 370c50d8ae3SPaolo Bonzini 371c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 372c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 373c50d8ae3SPaolo Bonzini 374c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 375c50d8ae3SPaolo Bonzini 376c50d8ae3SPaolo Bonzini /* 377c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 378c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 379c50d8ae3SPaolo Bonzini */ 380c50d8ae3SPaolo Bonzini smp_wmb(); 381c50d8ae3SPaolo Bonzini 382c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 383c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 384c50d8ae3SPaolo Bonzini } 385c50d8ae3SPaolo Bonzini 386c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 387c50d8ae3SPaolo Bonzini { 388c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 389c50d8ae3SPaolo Bonzini 390c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 391c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 392c50d8ae3SPaolo Bonzini 393c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 394c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 395c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 396c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 397c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 398c50d8ae3SPaolo Bonzini 399c50d8ae3SPaolo Bonzini return orig.spte; 400c50d8ae3SPaolo Bonzini } 401c50d8ae3SPaolo Bonzini 402c50d8ae3SPaolo Bonzini /* 403c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 404c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 405c50d8ae3SPaolo Bonzini * 406aed02fe3SSean Christopherson * An spte tlb flush may be pending, because kvm_set_pte_rmap 407c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 408c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 409c50d8ae3SPaolo Bonzini * 410c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 411c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 412c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 413c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 414c50d8ae3SPaolo Bonzini * 415c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 416c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 417c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 418c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 419c50d8ae3SPaolo Bonzini */ 420c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 421c50d8ae3SPaolo Bonzini { 42257354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 423c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 424c50d8ae3SPaolo Bonzini int count; 425c50d8ae3SPaolo Bonzini 426c50d8ae3SPaolo Bonzini retry: 427c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 428c50d8ae3SPaolo Bonzini smp_rmb(); 429c50d8ae3SPaolo Bonzini 430c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 431c50d8ae3SPaolo Bonzini smp_rmb(); 432c50d8ae3SPaolo Bonzini 433c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 434c50d8ae3SPaolo Bonzini smp_rmb(); 435c50d8ae3SPaolo Bonzini 436c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 437c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 438c50d8ae3SPaolo Bonzini goto retry; 439c50d8ae3SPaolo Bonzini 440c50d8ae3SPaolo Bonzini return spte.spte; 441c50d8ae3SPaolo Bonzini } 442c50d8ae3SPaolo Bonzini #endif 443c50d8ae3SPaolo Bonzini 444c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 445c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 446c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 447c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 448c50d8ae3SPaolo Bonzini * the spte. 449c50d8ae3SPaolo Bonzini */ 450c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 451c50d8ae3SPaolo Bonzini { 452c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 453c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 454c50d8ae3SPaolo Bonzini } 455c50d8ae3SPaolo Bonzini 456c50d8ae3SPaolo Bonzini /* 457c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 458c50d8ae3SPaolo Bonzini * accessed/dirty status. 459c50d8ae3SPaolo Bonzini */ 460c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 461c50d8ae3SPaolo Bonzini { 462c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 463c50d8ae3SPaolo Bonzini 464c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 465115111efSDavid Matlack check_spte_writable_invariants(new_spte); 466c50d8ae3SPaolo Bonzini 467c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 468c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 469c50d8ae3SPaolo Bonzini return old_spte; 470c50d8ae3SPaolo Bonzini } 471c50d8ae3SPaolo Bonzini 472c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 473c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 474c50d8ae3SPaolo Bonzini else 475c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 476c50d8ae3SPaolo Bonzini 477c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 478c50d8ae3SPaolo Bonzini 479c50d8ae3SPaolo Bonzini return old_spte; 480c50d8ae3SPaolo Bonzini } 481c50d8ae3SPaolo Bonzini 482c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 483c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 484c50d8ae3SPaolo Bonzini * 48502844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 48602844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 48702844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 488c50d8ae3SPaolo Bonzini * 489c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 490c50d8ae3SPaolo Bonzini */ 491c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 492c50d8ae3SPaolo Bonzini { 493c50d8ae3SPaolo Bonzini bool flush = false; 494c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 495c50d8ae3SPaolo Bonzini 496c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 497c50d8ae3SPaolo Bonzini return false; 498c50d8ae3SPaolo Bonzini 499c50d8ae3SPaolo Bonzini /* 500c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 501c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 502c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 503c50d8ae3SPaolo Bonzini */ 504706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 505c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 506c50d8ae3SPaolo Bonzini flush = true; 507c50d8ae3SPaolo Bonzini 508c50d8ae3SPaolo Bonzini /* 509c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 510c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 511c50d8ae3SPaolo Bonzini */ 512c50d8ae3SPaolo Bonzini 513c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 514c50d8ae3SPaolo Bonzini flush = true; 515c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 516c50d8ae3SPaolo Bonzini } 517c50d8ae3SPaolo Bonzini 518c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 519c50d8ae3SPaolo Bonzini flush = true; 520c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 521c50d8ae3SPaolo Bonzini } 522c50d8ae3SPaolo Bonzini 523c50d8ae3SPaolo Bonzini return flush; 524c50d8ae3SPaolo Bonzini } 525c50d8ae3SPaolo Bonzini 526c50d8ae3SPaolo Bonzini /* 527c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 528c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 529c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5307fa2a347SSean Christopherson * Returns the old PTE. 531c50d8ae3SPaolo Bonzini */ 53235d539c3SSean Christopherson static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 533c50d8ae3SPaolo Bonzini { 534c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 535c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 53671f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 537b14b2690SSean Christopherson struct page *page; 538c50d8ae3SPaolo Bonzini 53954eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 54054eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 541c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 542c50d8ae3SPaolo Bonzini else 543c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 544c50d8ae3SPaolo Bonzini 545c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5467fa2a347SSean Christopherson return old_spte; 547c50d8ae3SPaolo Bonzini 54871f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 54971f51d2cSMingwei Zhang 550c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 551c50d8ae3SPaolo Bonzini 552c50d8ae3SPaolo Bonzini /* 553b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 554b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 555b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 556b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 557c50d8ae3SPaolo Bonzini */ 558b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 559b14b2690SSean Christopherson WARN_ON(page && !page_count(page)); 560c50d8ae3SPaolo Bonzini 561c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 562c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 563c50d8ae3SPaolo Bonzini 564c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 565c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 566c50d8ae3SPaolo Bonzini 5677fa2a347SSean Christopherson return old_spte; 568c50d8ae3SPaolo Bonzini } 569c50d8ae3SPaolo Bonzini 570c50d8ae3SPaolo Bonzini /* 571c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 572c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 573c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 574c50d8ae3SPaolo Bonzini */ 575c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 576c50d8ae3SPaolo Bonzini { 577c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 578c50d8ae3SPaolo Bonzini } 579c50d8ae3SPaolo Bonzini 580c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 581c50d8ae3SPaolo Bonzini { 582c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 583c50d8ae3SPaolo Bonzini } 584c50d8ae3SPaolo Bonzini 585c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 586c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 587c50d8ae3SPaolo Bonzini { 588c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 589c50d8ae3SPaolo Bonzini 590c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 591c50d8ae3SPaolo Bonzini return false; 592c50d8ae3SPaolo Bonzini 593c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 594c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 595c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 596c50d8ae3SPaolo Bonzini } else { 597c50d8ae3SPaolo Bonzini /* 598c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 599c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 600c50d8ae3SPaolo Bonzini */ 601c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 602c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 603c50d8ae3SPaolo Bonzini 604c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 605c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 606c50d8ae3SPaolo Bonzini } 607c50d8ae3SPaolo Bonzini 608c50d8ae3SPaolo Bonzini return true; 609c50d8ae3SPaolo Bonzini } 610c50d8ae3SPaolo Bonzini 611c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 612c50d8ae3SPaolo Bonzini { 613c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 614c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 615c5c8c7c5SDavid Matlack } else { 616c50d8ae3SPaolo Bonzini /* 617c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 618c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 619c50d8ae3SPaolo Bonzini */ 620c50d8ae3SPaolo Bonzini local_irq_disable(); 621c50d8ae3SPaolo Bonzini 622c50d8ae3SPaolo Bonzini /* 623c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 624c50d8ae3SPaolo Bonzini * to vcpu->mode. 625c50d8ae3SPaolo Bonzini */ 626c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 627c50d8ae3SPaolo Bonzini } 628c5c8c7c5SDavid Matlack } 629c50d8ae3SPaolo Bonzini 630c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 631c50d8ae3SPaolo Bonzini { 632c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 633c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 634c5c8c7c5SDavid Matlack } else { 635c50d8ae3SPaolo Bonzini /* 636c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 637c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 638c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 639c50d8ae3SPaolo Bonzini */ 640c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 641c50d8ae3SPaolo Bonzini local_irq_enable(); 642c50d8ae3SPaolo Bonzini } 643c5c8c7c5SDavid Matlack } 644c50d8ae3SPaolo Bonzini 645378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 646c50d8ae3SPaolo Bonzini { 647c50d8ae3SPaolo Bonzini int r; 648c50d8ae3SPaolo Bonzini 649531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 65094ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 651531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 652c50d8ae3SPaolo Bonzini if (r) 653c50d8ae3SPaolo Bonzini return r; 65494ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 655171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 656171a90d7SSean Christopherson if (r) 657171a90d7SSean Christopherson return r; 658378f5cd6SSean Christopherson if (maybe_indirect) { 6596a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 660171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 661c50d8ae3SPaolo Bonzini if (r) 662c50d8ae3SPaolo Bonzini return r; 663378f5cd6SSean Christopherson } 66494ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 665531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 666c50d8ae3SPaolo Bonzini } 667c50d8ae3SPaolo Bonzini 668c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 669c50d8ae3SPaolo Bonzini { 67094ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 67194ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 6726a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 67394ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 674c50d8ae3SPaolo Bonzini } 675c50d8ae3SPaolo Bonzini 676c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 677c50d8ae3SPaolo Bonzini { 678c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 679c50d8ae3SPaolo Bonzini } 680c50d8ae3SPaolo Bonzini 6816a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 6826a97575dSDavid Matlack 683c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 684c50d8ae3SPaolo Bonzini { 68584e5ffd0SLai Jiangshan if (sp->role.passthrough) 68684e5ffd0SLai Jiangshan return sp->gfn; 68784e5ffd0SLai Jiangshan 688c50d8ae3SPaolo Bonzini if (!sp->role.direct) 6896a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 690c50d8ae3SPaolo Bonzini 6912ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 692c50d8ae3SPaolo Bonzini } 693c50d8ae3SPaolo Bonzini 6946a97575dSDavid Matlack /* 6956a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 6966a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 6976a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 6986a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 6996a97575dSDavid Matlack */ 7006a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 701c50d8ae3SPaolo Bonzini { 7026a97575dSDavid Matlack if (sp_has_gptes(sp)) 7036a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7046a97575dSDavid Matlack 7056a97575dSDavid Matlack /* 7066a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7076a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7086a97575dSDavid Matlack * permissions" are just ACC_ALL. 7096a97575dSDavid Matlack * 7106a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7116a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7126a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7136a97575dSDavid Matlack * page. 7146a97575dSDavid Matlack * 7156a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7166a97575dSDavid Matlack */ 7176a97575dSDavid Matlack return sp->role.access; 7186a97575dSDavid Matlack } 7196a97575dSDavid Matlack 72072ae5822SSean Christopherson static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, 72172ae5822SSean Christopherson gfn_t gfn, unsigned int access) 7226a97575dSDavid Matlack { 7236a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7246a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 72584e5ffd0SLai Jiangshan return; 72684e5ffd0SLai Jiangshan } 72784e5ffd0SLai Jiangshan 7286a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7296a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7306a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7316a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7326a97575dSDavid Matlack 7336a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7346a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7356a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7366a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 737c50d8ae3SPaolo Bonzini } 738c50d8ae3SPaolo Bonzini 73972ae5822SSean Christopherson static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, 74072ae5822SSean Christopherson unsigned int access) 7416a97575dSDavid Matlack { 7426a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7436a97575dSDavid Matlack 7446a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 745c50d8ae3SPaolo Bonzini } 746c50d8ae3SPaolo Bonzini 747c50d8ae3SPaolo Bonzini /* 748c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 749c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 750c50d8ae3SPaolo Bonzini */ 751c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7528ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 753c50d8ae3SPaolo Bonzini { 754c50d8ae3SPaolo Bonzini unsigned long idx; 755c50d8ae3SPaolo Bonzini 756c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 757c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 758c50d8ae3SPaolo Bonzini } 759c50d8ae3SPaolo Bonzini 760269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 761c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 762c50d8ae3SPaolo Bonzini { 763c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 764c50d8ae3SPaolo Bonzini int i; 765c50d8ae3SPaolo Bonzini 7663bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 767c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 768c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 769c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 770c50d8ae3SPaolo Bonzini } 771c50d8ae3SPaolo Bonzini } 772c50d8ae3SPaolo Bonzini 773269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 774c50d8ae3SPaolo Bonzini { 775c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 776c50d8ae3SPaolo Bonzini } 777c50d8ae3SPaolo Bonzini 778269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 779c50d8ae3SPaolo Bonzini { 780c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 781c50d8ae3SPaolo Bonzini } 782c50d8ae3SPaolo Bonzini 783c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 784c50d8ae3SPaolo Bonzini { 785c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 786c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 787c50d8ae3SPaolo Bonzini gfn_t gfn; 788c50d8ae3SPaolo Bonzini 789c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 790c50d8ae3SPaolo Bonzini gfn = sp->gfn; 791c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 792c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 793c50d8ae3SPaolo Bonzini 794c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 7953bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 796c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 797c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 798c50d8ae3SPaolo Bonzini 799c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 800be911771SDavid Matlack 801be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 802be911771SDavid Matlack kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 803c50d8ae3SPaolo Bonzini } 804c50d8ae3SPaolo Bonzini 80529cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 806c50d8ae3SPaolo Bonzini { 807c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 808c50d8ae3SPaolo Bonzini return; 809c50d8ae3SPaolo Bonzini 810c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 811c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 812c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 813c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 814c50d8ae3SPaolo Bonzini } 815c50d8ae3SPaolo Bonzini 816c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 817c50d8ae3SPaolo Bonzini { 818c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 819c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 820c50d8ae3SPaolo Bonzini gfn_t gfn; 821c50d8ae3SPaolo Bonzini 822c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 823c50d8ae3SPaolo Bonzini gfn = sp->gfn; 824c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 825c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8263bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 827c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 828c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 829c50d8ae3SPaolo Bonzini 830c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 831c50d8ae3SPaolo Bonzini } 832c50d8ae3SPaolo Bonzini 83329cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 834c50d8ae3SPaolo Bonzini { 835c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 836c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 837c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 838c50d8ae3SPaolo Bonzini } 839c50d8ae3SPaolo Bonzini 840c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 841c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 842c50d8ae3SPaolo Bonzini bool no_dirty_log) 843c50d8ae3SPaolo Bonzini { 844c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 845c50d8ae3SPaolo Bonzini 846c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 84791b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 84891b0d268SPaolo Bonzini return NULL; 849044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 85091b0d268SPaolo Bonzini return NULL; 851c50d8ae3SPaolo Bonzini 852c50d8ae3SPaolo Bonzini return slot; 853c50d8ae3SPaolo Bonzini } 854c50d8ae3SPaolo Bonzini 855c50d8ae3SPaolo Bonzini /* 856c50d8ae3SPaolo Bonzini * About rmap_head encoding: 857c50d8ae3SPaolo Bonzini * 858c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 859c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 860c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 861c50d8ae3SPaolo Bonzini */ 862c50d8ae3SPaolo Bonzini 863c50d8ae3SPaolo Bonzini /* 864c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 865c50d8ae3SPaolo Bonzini */ 8662ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 867c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 868c50d8ae3SPaolo Bonzini { 869c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 87013236e25SPeter Xu int count = 0; 871c50d8ae3SPaolo Bonzini 872c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 873805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 874c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 875c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 876805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 8772ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 878c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 879c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 88013236e25SPeter Xu desc->spte_count = 2; 881c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 882c50d8ae3SPaolo Bonzini ++count; 883c50d8ae3SPaolo Bonzini } else { 884805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 885c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 88613236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 887c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 888c6c4f961SLi RongQing if (!desc->more) { 8892ff9039aSDavid Matlack desc->more = kvm_mmu_memory_cache_alloc(cache); 890c50d8ae3SPaolo Bonzini desc = desc->more; 89113236e25SPeter Xu desc->spte_count = 0; 892c6c4f961SLi RongQing break; 893c6c4f961SLi RongQing } 894c6c4f961SLi RongQing desc = desc->more; 895c50d8ae3SPaolo Bonzini } 89613236e25SPeter Xu count += desc->spte_count; 89713236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 898c50d8ae3SPaolo Bonzini } 899c50d8ae3SPaolo Bonzini return count; 900c50d8ae3SPaolo Bonzini } 901c50d8ae3SPaolo Bonzini 902c50d8ae3SPaolo Bonzini static void 903c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 904c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 905c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 906c50d8ae3SPaolo Bonzini { 90713236e25SPeter Xu int j = desc->spte_count - 1; 908c50d8ae3SPaolo Bonzini 909c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 910c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 91113236e25SPeter Xu desc->spte_count--; 91213236e25SPeter Xu if (desc->spte_count) 913c50d8ae3SPaolo Bonzini return; 914c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 915fe3c2b4cSMiaohe Lin rmap_head->val = 0; 916c50d8ae3SPaolo Bonzini else 917c50d8ae3SPaolo Bonzini if (prev_desc) 918c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 919c50d8ae3SPaolo Bonzini else 920c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 921c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 922c50d8ae3SPaolo Bonzini } 923c50d8ae3SPaolo Bonzini 9243c2e1037SSean Christopherson static void pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 925c50d8ae3SPaolo Bonzini { 926c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 927c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 928c50d8ae3SPaolo Bonzini int i; 929c50d8ae3SPaolo Bonzini 930c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 931c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 932c50d8ae3SPaolo Bonzini BUG(); 933c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 934805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 935c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 936c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 937c50d8ae3SPaolo Bonzini BUG(); 938c50d8ae3SPaolo Bonzini } 939c50d8ae3SPaolo Bonzini rmap_head->val = 0; 940c50d8ae3SPaolo Bonzini } else { 941805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 942c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 943c50d8ae3SPaolo Bonzini prev_desc = NULL; 944c50d8ae3SPaolo Bonzini while (desc) { 94513236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 946c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 947c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 948c50d8ae3SPaolo Bonzini desc, i, prev_desc); 949c50d8ae3SPaolo Bonzini return; 950c50d8ae3SPaolo Bonzini } 951c50d8ae3SPaolo Bonzini } 952c50d8ae3SPaolo Bonzini prev_desc = desc; 953c50d8ae3SPaolo Bonzini desc = desc->more; 954c50d8ae3SPaolo Bonzini } 955c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 956c50d8ae3SPaolo Bonzini BUG(); 957c50d8ae3SPaolo Bonzini } 958c50d8ae3SPaolo Bonzini } 959c50d8ae3SPaolo Bonzini 9609202aee8SSean Christopherson static void kvm_zap_one_rmap_spte(struct kvm *kvm, 9619202aee8SSean Christopherson struct kvm_rmap_head *rmap_head, u64 *sptep) 962c50d8ae3SPaolo Bonzini { 96371f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 9643c2e1037SSean Christopherson pte_list_remove(sptep, rmap_head); 965c50d8ae3SPaolo Bonzini } 966c50d8ae3SPaolo Bonzini 9679202aee8SSean Christopherson /* Return true if at least one SPTE was zapped, false otherwise */ 9689202aee8SSean Christopherson static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 9699202aee8SSean Christopherson struct kvm_rmap_head *rmap_head) 970a75b5404SPeter Xu { 971a75b5404SPeter Xu struct pte_list_desc *desc, *next; 972a75b5404SPeter Xu int i; 973a75b5404SPeter Xu 974a75b5404SPeter Xu if (!rmap_head->val) 975a75b5404SPeter Xu return false; 976a75b5404SPeter Xu 977a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 97871f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 979a75b5404SPeter Xu goto out; 980a75b5404SPeter Xu } 981a75b5404SPeter Xu 982a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 983a75b5404SPeter Xu 984a75b5404SPeter Xu for (; desc; desc = next) { 985a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 98671f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 987a75b5404SPeter Xu next = desc->more; 988a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 989a75b5404SPeter Xu } 990a75b5404SPeter Xu out: 991a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 992a75b5404SPeter Xu rmap_head->val = 0; 993a75b5404SPeter Xu return true; 994a75b5404SPeter Xu } 995a75b5404SPeter Xu 9963bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 9973bcd0662SPeter Xu { 9983bcd0662SPeter Xu struct pte_list_desc *desc; 9993bcd0662SPeter Xu unsigned int count = 0; 10003bcd0662SPeter Xu 10013bcd0662SPeter Xu if (!rmap_head->val) 10023bcd0662SPeter Xu return 0; 10033bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10043bcd0662SPeter Xu return 1; 10053bcd0662SPeter Xu 10063bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10073bcd0662SPeter Xu 10083bcd0662SPeter Xu while (desc) { 10093bcd0662SPeter Xu count += desc->spte_count; 10103bcd0662SPeter Xu desc = desc->more; 10113bcd0662SPeter Xu } 10123bcd0662SPeter Xu 10133bcd0662SPeter Xu return count; 10143bcd0662SPeter Xu } 10153bcd0662SPeter Xu 101693e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1017269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1018c50d8ae3SPaolo Bonzini { 1019c50d8ae3SPaolo Bonzini unsigned long idx; 1020c50d8ae3SPaolo Bonzini 1021c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10223bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1023c50d8ae3SPaolo Bonzini } 1024c50d8ae3SPaolo Bonzini 1025c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1026c50d8ae3SPaolo Bonzini { 1027356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1028c50d8ae3SPaolo Bonzini 1029356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 103094ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1031c50d8ae3SPaolo Bonzini } 1032c50d8ae3SPaolo Bonzini 1033c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1034c50d8ae3SPaolo Bonzini { 1035601f8af0SDavid Matlack struct kvm_memslots *slots; 1036601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1037c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1038c50d8ae3SPaolo Bonzini gfn_t gfn; 1039c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1040c50d8ae3SPaolo Bonzini 104157354682SSean Christopherson sp = sptep_to_sp(spte); 104279e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(spte)); 1043601f8af0SDavid Matlack 1044601f8af0SDavid Matlack /* 104568be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 104668be1306SDavid Matlack * so we have to determine which memslots to use based on context 104768be1306SDavid Matlack * information in sp->role. 1048601f8af0SDavid Matlack */ 1049601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1050601f8af0SDavid Matlack 1051601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 105293e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1053601f8af0SDavid Matlack 10543c2e1037SSean Christopherson pte_list_remove(spte, rmap_head); 1055c50d8ae3SPaolo Bonzini } 1056c50d8ae3SPaolo Bonzini 1057c50d8ae3SPaolo Bonzini /* 1058c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1059c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1060c50d8ae3SPaolo Bonzini */ 1061c50d8ae3SPaolo Bonzini struct rmap_iterator { 1062c50d8ae3SPaolo Bonzini /* private fields */ 1063c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1064c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1065c50d8ae3SPaolo Bonzini }; 1066c50d8ae3SPaolo Bonzini 1067c50d8ae3SPaolo Bonzini /* 1068c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1069c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10700a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1071c50d8ae3SPaolo Bonzini * 1072c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1073c50d8ae3SPaolo Bonzini */ 1074c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1075c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1076c50d8ae3SPaolo Bonzini { 1077c50d8ae3SPaolo Bonzini u64 *sptep; 1078c50d8ae3SPaolo Bonzini 1079c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1080c50d8ae3SPaolo Bonzini return NULL; 1081c50d8ae3SPaolo Bonzini 1082c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1083c50d8ae3SPaolo Bonzini iter->desc = NULL; 1084c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1085c50d8ae3SPaolo Bonzini goto out; 1086c50d8ae3SPaolo Bonzini } 1087c50d8ae3SPaolo Bonzini 1088c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1089c50d8ae3SPaolo Bonzini iter->pos = 0; 1090c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1091c50d8ae3SPaolo Bonzini out: 1092c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1093c50d8ae3SPaolo Bonzini return sptep; 1094c50d8ae3SPaolo Bonzini } 1095c50d8ae3SPaolo Bonzini 1096c50d8ae3SPaolo Bonzini /* 1097c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1098c50d8ae3SPaolo Bonzini * 1099c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1100c50d8ae3SPaolo Bonzini */ 1101c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1102c50d8ae3SPaolo Bonzini { 1103c50d8ae3SPaolo Bonzini u64 *sptep; 1104c50d8ae3SPaolo Bonzini 1105c50d8ae3SPaolo Bonzini if (iter->desc) { 1106c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1107c50d8ae3SPaolo Bonzini ++iter->pos; 1108c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1109c50d8ae3SPaolo Bonzini if (sptep) 1110c50d8ae3SPaolo Bonzini goto out; 1111c50d8ae3SPaolo Bonzini } 1112c50d8ae3SPaolo Bonzini 1113c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1114c50d8ae3SPaolo Bonzini 1115c50d8ae3SPaolo Bonzini if (iter->desc) { 1116c50d8ae3SPaolo Bonzini iter->pos = 0; 1117c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1118c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1119c50d8ae3SPaolo Bonzini goto out; 1120c50d8ae3SPaolo Bonzini } 1121c50d8ae3SPaolo Bonzini } 1122c50d8ae3SPaolo Bonzini 1123c50d8ae3SPaolo Bonzini return NULL; 1124c50d8ae3SPaolo Bonzini out: 1125c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1126c50d8ae3SPaolo Bonzini return sptep; 1127c50d8ae3SPaolo Bonzini } 1128c50d8ae3SPaolo Bonzini 1129c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1130c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1131c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1132c50d8ae3SPaolo Bonzini 1133c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1134c50d8ae3SPaolo Bonzini { 113571f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11367fa2a347SSean Christopherson 11377fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1138c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1139c50d8ae3SPaolo Bonzini } 1140c50d8ae3SPaolo Bonzini 114103787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1142c50d8ae3SPaolo Bonzini { 11430cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 11440cd8dc73SPaolo Bonzini 11450cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 11460cd8dc73SPaolo Bonzini WARN_ON(sp->role.level == PG_LEVEL_4K); 11470cd8dc73SPaolo Bonzini 1148c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 114903787394SPaolo Bonzini 115003787394SPaolo Bonzini if (flush) 11510cd8dc73SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 1152c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1153c50d8ae3SPaolo Bonzini } 1154c50d8ae3SPaolo Bonzini 1155c50d8ae3SPaolo Bonzini /* 1156c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1157c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1158c50d8ae3SPaolo Bonzini * 1159c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1160c50d8ae3SPaolo Bonzini * protection: 1161c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1162c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1163c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1164c50d8ae3SPaolo Bonzini * shadow page. 1165c50d8ae3SPaolo Bonzini * 1166c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1167c50d8ae3SPaolo Bonzini */ 1168c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1169c50d8ae3SPaolo Bonzini { 1170c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1171c50d8ae3SPaolo Bonzini 1172c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1173706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1174c50d8ae3SPaolo Bonzini return false; 1175c50d8ae3SPaolo Bonzini 1176805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1177c50d8ae3SPaolo Bonzini 1178c50d8ae3SPaolo Bonzini if (pt_protect) 11795fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1180c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1181c50d8ae3SPaolo Bonzini 1182c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1183c50d8ae3SPaolo Bonzini } 1184c50d8ae3SPaolo Bonzini 11851346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1186c50d8ae3SPaolo Bonzini bool pt_protect) 1187c50d8ae3SPaolo Bonzini { 1188c50d8ae3SPaolo Bonzini u64 *sptep; 1189c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1190c50d8ae3SPaolo Bonzini bool flush = false; 1191c50d8ae3SPaolo Bonzini 1192c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1193c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1194c50d8ae3SPaolo Bonzini 1195c50d8ae3SPaolo Bonzini return flush; 1196c50d8ae3SPaolo Bonzini } 1197c50d8ae3SPaolo Bonzini 1198c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1199c50d8ae3SPaolo Bonzini { 1200c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1201c50d8ae3SPaolo Bonzini 1202805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1203c50d8ae3SPaolo Bonzini 1204c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1205c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1206c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1207c50d8ae3SPaolo Bonzini } 1208c50d8ae3SPaolo Bonzini 1209c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1210c50d8ae3SPaolo Bonzini { 1211c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1212c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1213c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1214c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1215c50d8ae3SPaolo Bonzini 1216c50d8ae3SPaolo Bonzini return was_writable; 1217c50d8ae3SPaolo Bonzini } 1218c50d8ae3SPaolo Bonzini 1219c50d8ae3SPaolo Bonzini /* 1220c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1221c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1222c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1223c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1224c50d8ae3SPaolo Bonzini */ 12250a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1226269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1227c50d8ae3SPaolo Bonzini { 1228c50d8ae3SPaolo Bonzini u64 *sptep; 1229c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1230c50d8ae3SPaolo Bonzini bool flush = false; 1231c50d8ae3SPaolo Bonzini 1232c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1233c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1234c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1235c50d8ae3SPaolo Bonzini else 1236c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1237c50d8ae3SPaolo Bonzini 1238c50d8ae3SPaolo Bonzini return flush; 1239c50d8ae3SPaolo Bonzini } 1240c50d8ae3SPaolo Bonzini 1241c50d8ae3SPaolo Bonzini /** 1242c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1243c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1244c50d8ae3SPaolo Bonzini * @slot: slot to protect 1245c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1246c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1247c50d8ae3SPaolo Bonzini * 124889212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1249c50d8ae3SPaolo Bonzini */ 1250c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1251c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1252c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1253c50d8ae3SPaolo Bonzini { 1254c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1255c50d8ae3SPaolo Bonzini 1256897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1257a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1258a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1259e2209710SBen Gardon 1260e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1261e2209710SBen Gardon return; 1262e2209710SBen Gardon 1263c50d8ae3SPaolo Bonzini while (mask) { 126493e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12653bae0459SSean Christopherson PG_LEVEL_4K, slot); 12661346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1267c50d8ae3SPaolo Bonzini 1268c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1269c50d8ae3SPaolo Bonzini mask &= mask - 1; 1270c50d8ae3SPaolo Bonzini } 1271c50d8ae3SPaolo Bonzini } 1272c50d8ae3SPaolo Bonzini 1273c50d8ae3SPaolo Bonzini /** 1274c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1275c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1276c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1277c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1278c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1279c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1280c50d8ae3SPaolo Bonzini * 1281c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1282c50d8ae3SPaolo Bonzini */ 1283a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1284c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1285c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1286c50d8ae3SPaolo Bonzini { 1287c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1288c50d8ae3SPaolo Bonzini 1289897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1290a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1291a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1292e2209710SBen Gardon 1293e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1294e2209710SBen Gardon return; 1295e2209710SBen Gardon 1296c50d8ae3SPaolo Bonzini while (mask) { 129793e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12983bae0459SSean Christopherson PG_LEVEL_4K, slot); 12990a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1300c50d8ae3SPaolo Bonzini 1301c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1302c50d8ae3SPaolo Bonzini mask &= mask - 1; 1303c50d8ae3SPaolo Bonzini } 1304c50d8ae3SPaolo Bonzini } 1305c50d8ae3SPaolo Bonzini 1306c50d8ae3SPaolo Bonzini /** 1307c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1308c50d8ae3SPaolo Bonzini * PT level pages. 1309c50d8ae3SPaolo Bonzini * 1310c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1311c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1312c50d8ae3SPaolo Bonzini * 131389212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 131489212919SKeqian Zhu * have such mappings. 1315c50d8ae3SPaolo Bonzini */ 1316c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1317c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1318c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1319c50d8ae3SPaolo Bonzini { 132089212919SKeqian Zhu /* 132189212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 132289212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 132389212919SKeqian Zhu * are split to 4K on the first write. 132489212919SKeqian Zhu * 132589212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 132689212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 132789212919SKeqian Zhu * pages. 132889212919SKeqian Zhu */ 132989212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 133089212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 133189212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 133289212919SKeqian Zhu 1333cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1334cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1335cb00a70bSDavid Matlack 133689212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 133789212919SKeqian Zhu 133889212919SKeqian Zhu /* Cross two large pages? */ 133989212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 134089212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 134189212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 134289212919SKeqian Zhu PG_LEVEL_2M); 134389212919SKeqian Zhu } 134489212919SKeqian Zhu 134589212919SKeqian Zhu /* Now handle 4K PTEs. */ 1346a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1347a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1348c50d8ae3SPaolo Bonzini else 1349c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1350c50d8ae3SPaolo Bonzini } 1351c50d8ae3SPaolo Bonzini 1352fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1353fb04a1edSPeter Xu { 13546dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1355fb04a1edSPeter Xu } 1356fb04a1edSPeter Xu 1357c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13583ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13593ad93562SKeqian Zhu int min_level) 1360c50d8ae3SPaolo Bonzini { 1361c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1362c50d8ae3SPaolo Bonzini int i; 1363c50d8ae3SPaolo Bonzini bool write_protected = false; 1364c50d8ae3SPaolo Bonzini 1365e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13663ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 136793e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13681346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1369c50d8ae3SPaolo Bonzini } 1370e2209710SBen Gardon } 1371c50d8ae3SPaolo Bonzini 1372897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 137346044f72SBen Gardon write_protected |= 13743ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 137546044f72SBen Gardon 1376c50d8ae3SPaolo Bonzini return write_protected; 1377c50d8ae3SPaolo Bonzini } 1378c50d8ae3SPaolo Bonzini 1379cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1380c50d8ae3SPaolo Bonzini { 1381c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1382c50d8ae3SPaolo Bonzini 1383c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 13843ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1385c50d8ae3SPaolo Bonzini } 1386c50d8ae3SPaolo Bonzini 1387f8480721SSean Christopherson static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1388269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1389c50d8ae3SPaolo Bonzini { 13909202aee8SSean Christopherson return kvm_zap_all_rmap_sptes(kvm, rmap_head); 1391c50d8ae3SPaolo Bonzini } 1392c50d8ae3SPaolo Bonzini 1393f8480721SSean Christopherson static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1394c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 13953039bcc7SSean Christopherson pte_t unused) 1396c50d8ae3SPaolo Bonzini { 1397f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1398c50d8ae3SPaolo Bonzini } 1399c50d8ae3SPaolo Bonzini 1400aed02fe3SSean Christopherson static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1401c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14023039bcc7SSean Christopherson pte_t pte) 1403c50d8ae3SPaolo Bonzini { 1404c50d8ae3SPaolo Bonzini u64 *sptep; 1405c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 140698a26b69SVihas Mak bool need_flush = false; 1407c50d8ae3SPaolo Bonzini u64 new_spte; 1408c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1409c50d8ae3SPaolo Bonzini 14103039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14113039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1412c50d8ae3SPaolo Bonzini 1413c50d8ae3SPaolo Bonzini restart: 1414c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1415805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1416c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1417c50d8ae3SPaolo Bonzini 141898a26b69SVihas Mak need_flush = true; 1419c50d8ae3SPaolo Bonzini 14203039bcc7SSean Christopherson if (pte_write(pte)) { 14219202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 1422c50d8ae3SPaolo Bonzini goto restart; 1423c50d8ae3SPaolo Bonzini } else { 1424cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1425cb3eedabSPaolo Bonzini *sptep, new_pfn); 1426c50d8ae3SPaolo Bonzini 142771f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1428c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1429c50d8ae3SPaolo Bonzini } 1430c50d8ae3SPaolo Bonzini } 1431c50d8ae3SPaolo Bonzini 1432c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1433c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 143498a26b69SVihas Mak return false; 1435c50d8ae3SPaolo Bonzini } 1436c50d8ae3SPaolo Bonzini 1437c50d8ae3SPaolo Bonzini return need_flush; 1438c50d8ae3SPaolo Bonzini } 1439c50d8ae3SPaolo Bonzini 1440c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1441c50d8ae3SPaolo Bonzini /* input fields. */ 1442269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1443c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1444c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1445c50d8ae3SPaolo Bonzini int start_level; 1446c50d8ae3SPaolo Bonzini int end_level; 1447c50d8ae3SPaolo Bonzini 1448c50d8ae3SPaolo Bonzini /* output fields. */ 1449c50d8ae3SPaolo Bonzini gfn_t gfn; 1450c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1451c50d8ae3SPaolo Bonzini int level; 1452c50d8ae3SPaolo Bonzini 1453c50d8ae3SPaolo Bonzini /* private field. */ 1454c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1455c50d8ae3SPaolo Bonzini }; 1456c50d8ae3SPaolo Bonzini 1457c50d8ae3SPaolo Bonzini static void 1458c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1459c50d8ae3SPaolo Bonzini { 1460c50d8ae3SPaolo Bonzini iterator->level = level; 1461c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 146293e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 146393e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1464c50d8ae3SPaolo Bonzini } 1465c50d8ae3SPaolo Bonzini 1466c50d8ae3SPaolo Bonzini static void 1467c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1468269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1469c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1470c50d8ae3SPaolo Bonzini { 1471c50d8ae3SPaolo Bonzini iterator->slot = slot; 1472c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1473c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1474c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1475c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1476c50d8ae3SPaolo Bonzini 1477c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1478c50d8ae3SPaolo Bonzini } 1479c50d8ae3SPaolo Bonzini 1480c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1481c50d8ae3SPaolo Bonzini { 1482c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1483c50d8ae3SPaolo Bonzini } 1484c50d8ae3SPaolo Bonzini 1485c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1486c50d8ae3SPaolo Bonzini { 14876ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1488c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 14896ba1e04fSVipin Sharma 14906ba1e04fSVipin Sharma if (iterator->rmap->val) 1491c50d8ae3SPaolo Bonzini return; 1492c50d8ae3SPaolo Bonzini } 1493c50d8ae3SPaolo Bonzini 1494c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1495c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1496c50d8ae3SPaolo Bonzini return; 1497c50d8ae3SPaolo Bonzini } 1498c50d8ae3SPaolo Bonzini 1499c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1500c50d8ae3SPaolo Bonzini } 1501c50d8ae3SPaolo Bonzini 1502c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1503c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1504c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1505c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1506c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1507c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1508c50d8ae3SPaolo Bonzini 15093039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1510c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15113039bcc7SSean Christopherson int level, pte_t pte); 1512c1b91493SSean Christopherson 15133039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15143039bcc7SSean Christopherson struct kvm_gfn_range *range, 1515c1b91493SSean Christopherson rmap_handler_t handler) 1516c50d8ae3SPaolo Bonzini { 1517c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15183039bcc7SSean Christopherson bool ret = false; 1519c50d8ae3SPaolo Bonzini 15203039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15213039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15223039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15233039bcc7SSean Christopherson iterator.level, range->pte); 1524c50d8ae3SPaolo Bonzini 1525c50d8ae3SPaolo Bonzini return ret; 1526c50d8ae3SPaolo Bonzini } 1527c50d8ae3SPaolo Bonzini 15283039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1529c50d8ae3SPaolo Bonzini { 1530e2209710SBen Gardon bool flush = false; 1531c50d8ae3SPaolo Bonzini 1532e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1533f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1534063afacdSBen Gardon 1535897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1536c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1537063afacdSBen Gardon 15383039bcc7SSean Christopherson return flush; 1539c50d8ae3SPaolo Bonzini } 1540c50d8ae3SPaolo Bonzini 15413039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1542c50d8ae3SPaolo Bonzini { 1543e2209710SBen Gardon bool flush = false; 15441d8dd6b3SBen Gardon 1545e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1546aed02fe3SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); 15471d8dd6b3SBen Gardon 1548897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15493039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15501d8dd6b3SBen Gardon 15513039bcc7SSean Christopherson return flush; 1552c50d8ae3SPaolo Bonzini } 1553c50d8ae3SPaolo Bonzini 1554aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1555c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15563039bcc7SSean Christopherson pte_t unused) 1557c50d8ae3SPaolo Bonzini { 1558c50d8ae3SPaolo Bonzini u64 *sptep; 15593f649ab7SKees Cook struct rmap_iterator iter; 1560c50d8ae3SPaolo Bonzini int young = 0; 1561c50d8ae3SPaolo Bonzini 1562c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1563c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1564c50d8ae3SPaolo Bonzini 1565c50d8ae3SPaolo Bonzini return young; 1566c50d8ae3SPaolo Bonzini } 1567c50d8ae3SPaolo Bonzini 1568aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1569c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15703039bcc7SSean Christopherson int level, pte_t unused) 1571c50d8ae3SPaolo Bonzini { 1572c50d8ae3SPaolo Bonzini u64 *sptep; 1573c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1574c50d8ae3SPaolo Bonzini 1575c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1576c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 157798a26b69SVihas Mak return true; 157898a26b69SVihas Mak return false; 1579c50d8ae3SPaolo Bonzini } 1580c50d8ae3SPaolo Bonzini 1581c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1582c50d8ae3SPaolo Bonzini 15832ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 15842ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 15852ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 158672ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1587c50d8ae3SPaolo Bonzini { 1588c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 158968be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 159068be1306SDavid Matlack int rmap_count; 1591c50d8ae3SPaolo Bonzini 159257354682SSean Christopherson sp = sptep_to_sp(spte); 159379e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 159481cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 159581cb4657SDavid Matlack 159693e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 15972ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1598c50d8ae3SPaolo Bonzini 1599604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1600604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 160168be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16029202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 160368be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 16042ff9039aSDavid Matlack kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 160568be1306SDavid Matlack } 1606c50d8ae3SPaolo Bonzini } 1607c50d8ae3SPaolo Bonzini 16082ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 160972ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16102ff9039aSDavid Matlack { 16112ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16122ff9039aSDavid Matlack 16136a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16142ff9039aSDavid Matlack } 16152ff9039aSDavid Matlack 16163039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1617c50d8ae3SPaolo Bonzini { 1618e2209710SBen Gardon bool young = false; 1619f8e14497SBen Gardon 1620e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1621aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16223039bcc7SSean Christopherson 1623897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16243039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1625f8e14497SBen Gardon 1626f8e14497SBen Gardon return young; 1627c50d8ae3SPaolo Bonzini } 1628c50d8ae3SPaolo Bonzini 16293039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1630c50d8ae3SPaolo Bonzini { 1631e2209710SBen Gardon bool young = false; 1632f8e14497SBen Gardon 1633e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1634aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 16353039bcc7SSean Christopherson 1636897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16373039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1638f8e14497SBen Gardon 1639f8e14497SBen Gardon return young; 1640c50d8ae3SPaolo Bonzini } 1641c50d8ae3SPaolo Bonzini 1642c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1643c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1644c50d8ae3SPaolo Bonzini { 1645c50d8ae3SPaolo Bonzini u64 *pos; 1646c50d8ae3SPaolo Bonzini u64 *end; 1647c50d8ae3SPaolo Bonzini 1648*3adbdf81SMiaohe Lin for (pos = spt, end = pos + SPTE_ENT_PER_PAGE; pos != end; pos++) 1649c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1650c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1651c50d8ae3SPaolo Bonzini pos, *pos); 1652c50d8ae3SPaolo Bonzini return 0; 1653c50d8ae3SPaolo Bonzini } 1654c50d8ae3SPaolo Bonzini return 1; 1655c50d8ae3SPaolo Bonzini } 1656c50d8ae3SPaolo Bonzini #endif 1657c50d8ae3SPaolo Bonzini 1658c50d8ae3SPaolo Bonzini /* 1659c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1660c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1661c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1662c50d8ae3SPaolo Bonzini * faster 1663c50d8ae3SPaolo Bonzini */ 1664d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1665c50d8ae3SPaolo Bonzini { 1666c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1667c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1668c50d8ae3SPaolo Bonzini } 1669c50d8ae3SPaolo Bonzini 167043a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 167143a063caSYosry Ahmed { 167243a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 167343a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 167443a063caSYosry Ahmed } 167543a063caSYosry Ahmed 167643a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 167743a063caSYosry Ahmed { 167843a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 167943a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 168043a063caSYosry Ahmed } 168143a063caSYosry Ahmed 168287654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1683c50d8ae3SPaolo Bonzini { 1684c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1685c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1686c50d8ae3SPaolo Bonzini list_del(&sp->link); 1687c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1688c50d8ae3SPaolo Bonzini if (!sp->role.direct) 16896a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1690c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1691c50d8ae3SPaolo Bonzini } 1692c50d8ae3SPaolo Bonzini 1693c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1694c50d8ae3SPaolo Bonzini { 1695c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1696c50d8ae3SPaolo Bonzini } 1697c50d8ae3SPaolo Bonzini 16982ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1699c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1700c50d8ae3SPaolo Bonzini { 1701c50d8ae3SPaolo Bonzini if (!parent_pte) 1702c50d8ae3SPaolo Bonzini return; 1703c50d8ae3SPaolo Bonzini 17042ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1705c50d8ae3SPaolo Bonzini } 1706c50d8ae3SPaolo Bonzini 1707c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1708c50d8ae3SPaolo Bonzini u64 *parent_pte) 1709c50d8ae3SPaolo Bonzini { 17103c2e1037SSean Christopherson pte_list_remove(parent_pte, &sp->parent_ptes); 1711c50d8ae3SPaolo Bonzini } 1712c50d8ae3SPaolo Bonzini 1713c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1714c50d8ae3SPaolo Bonzini u64 *parent_pte) 1715c50d8ae3SPaolo Bonzini { 1716c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1717c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1718c50d8ae3SPaolo Bonzini } 1719c50d8ae3SPaolo Bonzini 1720c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1721c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1722c50d8ae3SPaolo Bonzini { 1723c50d8ae3SPaolo Bonzini u64 *sptep; 1724c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1725c50d8ae3SPaolo Bonzini 1726c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1727c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1728c50d8ae3SPaolo Bonzini } 1729c50d8ae3SPaolo Bonzini } 1730c50d8ae3SPaolo Bonzini 1731c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1732c50d8ae3SPaolo Bonzini { 1733c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1734c50d8ae3SPaolo Bonzini 173557354682SSean Christopherson sp = sptep_to_sp(spte); 173679e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1737c50d8ae3SPaolo Bonzini return; 1738c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1739c50d8ae3SPaolo Bonzini return; 1740c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1741c50d8ae3SPaolo Bonzini } 1742c50d8ae3SPaolo Bonzini 1743c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1744c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1745c50d8ae3SPaolo Bonzini { 1746c3e5e415SLai Jiangshan return -1; 1747c50d8ae3SPaolo Bonzini } 1748c50d8ae3SPaolo Bonzini 1749c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1750c50d8ae3SPaolo Bonzini 1751c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1752c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1753c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1754c50d8ae3SPaolo Bonzini unsigned int idx; 1755c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1756c50d8ae3SPaolo Bonzini unsigned int nr; 1757c50d8ae3SPaolo Bonzini }; 1758c50d8ae3SPaolo Bonzini 1759c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1760c50d8ae3SPaolo Bonzini int idx) 1761c50d8ae3SPaolo Bonzini { 1762c50d8ae3SPaolo Bonzini int i; 1763c50d8ae3SPaolo Bonzini 1764c50d8ae3SPaolo Bonzini if (sp->unsync) 1765c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1766c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1767c50d8ae3SPaolo Bonzini return 0; 1768c50d8ae3SPaolo Bonzini 1769c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1770c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1771c50d8ae3SPaolo Bonzini pvec->nr++; 1772c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1773c50d8ae3SPaolo Bonzini } 1774c50d8ae3SPaolo Bonzini 1775c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1776c50d8ae3SPaolo Bonzini { 1777c50d8ae3SPaolo Bonzini --sp->unsync_children; 1778c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1779c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1780c50d8ae3SPaolo Bonzini } 1781c50d8ae3SPaolo Bonzini 1782c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1783c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1784c50d8ae3SPaolo Bonzini { 1785c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1786c50d8ae3SPaolo Bonzini 1787c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1788c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1789c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1790c50d8ae3SPaolo Bonzini 1791c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1792c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1793c50d8ae3SPaolo Bonzini continue; 1794c50d8ae3SPaolo Bonzini } 1795c50d8ae3SPaolo Bonzini 17962ca3129eSSean Christopherson child = to_shadow_page(ent & SPTE_BASE_ADDR_MASK); 1797c50d8ae3SPaolo Bonzini 1798c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1799c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1800c50d8ae3SPaolo Bonzini return -ENOSPC; 1801c50d8ae3SPaolo Bonzini 1802c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1803c50d8ae3SPaolo Bonzini if (!ret) { 1804c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1805c50d8ae3SPaolo Bonzini continue; 1806c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1807c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1808c50d8ae3SPaolo Bonzini } else 1809c50d8ae3SPaolo Bonzini return ret; 1810c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1811c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1812c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1813c50d8ae3SPaolo Bonzini return -ENOSPC; 1814c50d8ae3SPaolo Bonzini } else 1815c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1816c50d8ae3SPaolo Bonzini } 1817c50d8ae3SPaolo Bonzini 1818c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1819c50d8ae3SPaolo Bonzini } 1820c50d8ae3SPaolo Bonzini 1821c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1822c50d8ae3SPaolo Bonzini 1823c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1824c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1825c50d8ae3SPaolo Bonzini { 1826c50d8ae3SPaolo Bonzini pvec->nr = 0; 1827c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1828c50d8ae3SPaolo Bonzini return 0; 1829c50d8ae3SPaolo Bonzini 1830c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1831c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1832c50d8ae3SPaolo Bonzini } 1833c50d8ae3SPaolo Bonzini 1834c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1835c50d8ae3SPaolo Bonzini { 1836c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1837c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1838c50d8ae3SPaolo Bonzini sp->unsync = 0; 1839c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1840c50d8ae3SPaolo Bonzini } 1841c50d8ae3SPaolo Bonzini 1842c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1843c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1844c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1845c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1846c50d8ae3SPaolo Bonzini 1847767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1848767d8d8dSLai Jiangshan { 1849767d8d8dSLai Jiangshan if (sp->role.direct) 1850767d8d8dSLai Jiangshan return false; 1851767d8d8dSLai Jiangshan 185284e5ffd0SLai Jiangshan if (sp->role.passthrough) 185384e5ffd0SLai Jiangshan return false; 185484e5ffd0SLai Jiangshan 1855767d8d8dSLai Jiangshan return true; 1856767d8d8dSLai Jiangshan } 1857767d8d8dSLai Jiangshan 1858ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1859ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1860c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1861c50d8ae3SPaolo Bonzini } else 1862c50d8ae3SPaolo Bonzini 1863767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1864ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1865ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1866767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1867c50d8ae3SPaolo Bonzini 18688d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1869c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1870c50d8ae3SPaolo Bonzini { 1871c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1872c3e5e415SLai Jiangshan 18738d5678a7SHou Wenlong if (ret < 0) 1874c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18758d5678a7SHou Wenlong return ret; 1876c50d8ae3SPaolo Bonzini } 1877c50d8ae3SPaolo Bonzini 1878c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1879c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1880c50d8ae3SPaolo Bonzini bool remote_flush) 1881c50d8ae3SPaolo Bonzini { 1882c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1883c50d8ae3SPaolo Bonzini return false; 1884c50d8ae3SPaolo Bonzini 1885c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1886c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1887c50d8ae3SPaolo Bonzini else 1888c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1889c50d8ae3SPaolo Bonzini return true; 1890c50d8ae3SPaolo Bonzini } 1891c50d8ae3SPaolo Bonzini 1892c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1893c50d8ae3SPaolo Bonzini { 1894a955cad8SSean Christopherson if (sp->role.invalid) 1895a955cad8SSean Christopherson return true; 1896a955cad8SSean Christopherson 1897fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 1898a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1899c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1900c50d8ae3SPaolo Bonzini } 1901c50d8ae3SPaolo Bonzini 1902c50d8ae3SPaolo Bonzini struct mmu_page_path { 1903c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1904c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1905c50d8ae3SPaolo Bonzini }; 1906c50d8ae3SPaolo Bonzini 1907c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1908c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1909c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1910c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1911c50d8ae3SPaolo Bonzini 1912c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1913c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1914c50d8ae3SPaolo Bonzini int i) 1915c50d8ae3SPaolo Bonzini { 1916c50d8ae3SPaolo Bonzini int n; 1917c50d8ae3SPaolo Bonzini 1918c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1919c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1920c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1921c50d8ae3SPaolo Bonzini int level = sp->role.level; 1922c50d8ae3SPaolo Bonzini 1923c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19243bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1925c50d8ae3SPaolo Bonzini break; 1926c50d8ae3SPaolo Bonzini 1927c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1928c50d8ae3SPaolo Bonzini } 1929c50d8ae3SPaolo Bonzini 1930c50d8ae3SPaolo Bonzini return n; 1931c50d8ae3SPaolo Bonzini } 1932c50d8ae3SPaolo Bonzini 1933c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1934c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1935c50d8ae3SPaolo Bonzini { 1936c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1937c50d8ae3SPaolo Bonzini int level; 1938c50d8ae3SPaolo Bonzini 1939c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1940c50d8ae3SPaolo Bonzini return 0; 1941c50d8ae3SPaolo Bonzini 1942c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1943c50d8ae3SPaolo Bonzini 1944c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1945c50d8ae3SPaolo Bonzini level = sp->role.level; 19463bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1947c50d8ae3SPaolo Bonzini 1948c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1949c50d8ae3SPaolo Bonzini 1950c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1951c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1952c50d8ae3SPaolo Bonzini */ 1953c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1954c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1955c50d8ae3SPaolo Bonzini } 1956c50d8ae3SPaolo Bonzini 1957c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1958c50d8ae3SPaolo Bonzini { 1959c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1960c50d8ae3SPaolo Bonzini unsigned int level = 0; 1961c50d8ae3SPaolo Bonzini 1962c50d8ae3SPaolo Bonzini do { 1963c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1964c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1965c50d8ae3SPaolo Bonzini if (!sp) 1966c50d8ae3SPaolo Bonzini return; 1967c50d8ae3SPaolo Bonzini 1968c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1969c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1970c50d8ae3SPaolo Bonzini level++; 1971c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1972c50d8ae3SPaolo Bonzini } 1973c50d8ae3SPaolo Bonzini 197465855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 197565855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1976c50d8ae3SPaolo Bonzini { 1977c50d8ae3SPaolo Bonzini int i; 1978c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1979c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1980c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1981c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1982c50d8ae3SPaolo Bonzini bool flush = false; 1983c50d8ae3SPaolo Bonzini 1984c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 1985c50d8ae3SPaolo Bonzini bool protected = false; 1986c50d8ae3SPaolo Bonzini 1987c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 1988cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 1989c50d8ae3SPaolo Bonzini 1990c50d8ae3SPaolo Bonzini if (protected) { 19915591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 1992c50d8ae3SPaolo Bonzini flush = false; 1993c50d8ae3SPaolo Bonzini } 1994c50d8ae3SPaolo Bonzini 1995c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 1996479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 19978d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 1998c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 1999c50d8ae3SPaolo Bonzini } 2000531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2001c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 200265855ed8SLai Jiangshan if (!can_yield) { 200365855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 200465855ed8SLai Jiangshan return -EINTR; 200565855ed8SLai Jiangshan } 200665855ed8SLai Jiangshan 2007531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2008c50d8ae3SPaolo Bonzini flush = false; 2009c50d8ae3SPaolo Bonzini } 2010c50d8ae3SPaolo Bonzini } 2011c50d8ae3SPaolo Bonzini 2012c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 201365855ed8SLai Jiangshan return 0; 2014c50d8ae3SPaolo Bonzini } 2015c50d8ae3SPaolo Bonzini 2016c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2017c50d8ae3SPaolo Bonzini { 2018c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2019c50d8ae3SPaolo Bonzini } 2020c50d8ae3SPaolo Bonzini 2021c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2022c50d8ae3SPaolo Bonzini { 202357354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2024c50d8ae3SPaolo Bonzini } 2025c50d8ae3SPaolo Bonzini 2026cbd858b1SDavid Matlack /* 2027cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2028cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2029cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2030cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2031cbd858b1SDavid Matlack */ 20323cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 20333cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 203494c81364SDavid Matlack gfn_t gfn, 203594c81364SDavid Matlack struct hlist_head *sp_list, 20362e65e842SDavid Matlack union kvm_mmu_page_role role) 2037c50d8ae3SPaolo Bonzini { 2038c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20398d5678a7SHou Wenlong int ret; 2040c50d8ae3SPaolo Bonzini int collisions = 0; 2041c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2042c50d8ae3SPaolo Bonzini 20433cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2044c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2045c50d8ae3SPaolo Bonzini collisions++; 2046c50d8ae3SPaolo Bonzini continue; 2047c50d8ae3SPaolo Bonzini } 2048c50d8ae3SPaolo Bonzini 2049ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2050ddc16abbSSean Christopherson /* 2051ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2052ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2053ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2054ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2055ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2056ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2057ddc16abbSSean Christopherson * upper-level page will be write-protected. 2058ddc16abbSSean Christopherson */ 20592e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 20603cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2061ddc16abbSSean Christopherson &invalid_list); 2062c50d8ae3SPaolo Bonzini continue; 2063ddc16abbSSean Christopherson } 2064c50d8ae3SPaolo Bonzini 2065bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2066bb924ca6SDavid Matlack if (sp->role.direct) 206794c81364SDavid Matlack goto out; 2068fb58a9c3SSean Christopherson 2069c50d8ae3SPaolo Bonzini if (sp->unsync) { 2070cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2071cbd858b1SDavid Matlack break; 2072cbd858b1SDavid Matlack 207307dc4f35SSean Christopherson /* 2074479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 207507dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 207607dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 207707dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 207807dc4f35SSean Christopherson * overhead of write protection is not incurred until the 207907dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 208007dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 208107dc4f35SSean Christopherson * 208207dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 208307dc4f35SSean Christopherson * in order to rebuild it. 2084c50d8ae3SPaolo Bonzini */ 20858d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 20868d5678a7SHou Wenlong if (ret < 0) 2087c50d8ae3SPaolo Bonzini break; 2088c50d8ae3SPaolo Bonzini 2089c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 20908d5678a7SHou Wenlong if (ret > 0) 20913cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2092c50d8ae3SPaolo Bonzini } 2093c50d8ae3SPaolo Bonzini 2094c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2095fb58a9c3SSean Christopherson 2096c50d8ae3SPaolo Bonzini goto out; 2097c50d8ae3SPaolo Bonzini } 2098c50d8ae3SPaolo Bonzini 209994c81364SDavid Matlack sp = NULL; 21003cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2101c50d8ae3SPaolo Bonzini 210294c81364SDavid Matlack out: 21033cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 210494c81364SDavid Matlack 21053cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 21063cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 210794c81364SDavid Matlack return sp; 210894c81364SDavid Matlack } 210994c81364SDavid Matlack 21102f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 21112f8b1b53SDavid Matlack struct shadow_page_caches { 21122f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 21132f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 21146a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 21152f8b1b53SDavid Matlack }; 21162f8b1b53SDavid Matlack 2117336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 21182f8b1b53SDavid Matlack struct shadow_page_caches *caches, 211994c81364SDavid Matlack gfn_t gfn, 212094c81364SDavid Matlack struct hlist_head *sp_list, 212194c81364SDavid Matlack union kvm_mmu_page_role role) 212294c81364SDavid Matlack { 2123c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2124c306aec8SDavid Matlack 21252f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 21262f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2127c306aec8SDavid Matlack if (!role.direct) 21286a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2129c306aec8SDavid Matlack 2130c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2131c306aec8SDavid Matlack 2132c306aec8SDavid Matlack /* 2133c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2134c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2135c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2136c306aec8SDavid Matlack */ 2137336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2138336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 213943a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2140c50d8ae3SPaolo Bonzini 2141c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2142c50d8ae3SPaolo Bonzini sp->role = role; 2143ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2144be911771SDavid Matlack if (sp_has_gptes(sp)) 2145336081fbSDavid Matlack account_shadowed(kvm, sp); 2146ddc16abbSSean Christopherson 214794c81364SDavid Matlack return sp; 214894c81364SDavid Matlack } 214994c81364SDavid Matlack 2150cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 21513cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 21523cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 21532f8b1b53SDavid Matlack struct shadow_page_caches *caches, 215487654643SDavid Matlack gfn_t gfn, 215594c81364SDavid Matlack union kvm_mmu_page_role role) 215694c81364SDavid Matlack { 215794c81364SDavid Matlack struct hlist_head *sp_list; 215894c81364SDavid Matlack struct kvm_mmu_page *sp; 215994c81364SDavid Matlack bool created = false; 216094c81364SDavid Matlack 21613cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 216294c81364SDavid Matlack 21633cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 216494c81364SDavid Matlack if (!sp) { 216594c81364SDavid Matlack created = true; 21663cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 216794c81364SDavid Matlack } 216894c81364SDavid Matlack 216994c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2170c50d8ae3SPaolo Bonzini return sp; 2171c50d8ae3SPaolo Bonzini } 2172c50d8ae3SPaolo Bonzini 21732f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 21742f8b1b53SDavid Matlack gfn_t gfn, 21752f8b1b53SDavid Matlack union kvm_mmu_page_role role) 21762f8b1b53SDavid Matlack { 21772f8b1b53SDavid Matlack struct shadow_page_caches caches = { 21782f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 21792f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 21806a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 21812f8b1b53SDavid Matlack }; 21822f8b1b53SDavid Matlack 21833cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 21842f8b1b53SDavid Matlack } 21852f8b1b53SDavid Matlack 218639944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 218739944ab9SSean Christopherson unsigned int access) 21882e65e842SDavid Matlack { 21892e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 21902e65e842SDavid Matlack union kvm_mmu_page_role role; 21912e65e842SDavid Matlack 21922e65e842SDavid Matlack role = parent_sp->role; 21932e65e842SDavid Matlack role.level--; 21942e65e842SDavid Matlack role.access = access; 21952e65e842SDavid Matlack role.direct = direct; 21962e65e842SDavid Matlack role.passthrough = 0; 21972e65e842SDavid Matlack 21982e65e842SDavid Matlack /* 21992e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 22002e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 22012e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 22022e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 22032e65e842SDavid Matlack * requires extra bookkeeping in the role. 22042e65e842SDavid Matlack * 22052e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 22062e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 22072e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 22082e65e842SDavid Matlack * the address space each maps. 22092e65e842SDavid Matlack * 22102e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 22112e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 22122e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 22132e65e842SDavid Matlack * 221439944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 221539944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 221639944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 221739944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 221839944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 221939944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 222039944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 222139944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 222239944ab9SSean Christopherson * _least_ significant bit of the PDE index. 22232e65e842SDavid Matlack */ 22242e65e842SDavid Matlack if (role.has_4_byte_gpte) { 22252e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 222679e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 22272e65e842SDavid Matlack } 22282e65e842SDavid Matlack 22292e65e842SDavid Matlack return role; 22302e65e842SDavid Matlack } 22312e65e842SDavid Matlack 22322e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 22332e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 22342e65e842SDavid Matlack bool direct, unsigned int access) 22352e65e842SDavid Matlack { 22362e65e842SDavid Matlack union kvm_mmu_page_role role; 22372e65e842SDavid Matlack 22380cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 22390cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 22400cd8dc73SPaolo Bonzini 22412e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 224287654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 22432e65e842SDavid Matlack } 22442e65e842SDavid Matlack 2245c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2246c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2247c50d8ae3SPaolo Bonzini u64 addr) 2248c50d8ae3SPaolo Bonzini { 2249c50d8ae3SPaolo Bonzini iterator->addr = addr; 2250c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2251a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2252c50d8ae3SPaolo Bonzini 225312ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 22544d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2255347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 225612ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2257c50d8ae3SPaolo Bonzini 2258c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2259c50d8ae3SPaolo Bonzini /* 2260c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2261c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2262c50d8ae3SPaolo Bonzini */ 2263b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2264c50d8ae3SPaolo Bonzini 2265c50d8ae3SPaolo Bonzini iterator->shadow_addr 2266c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 22672ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2268c50d8ae3SPaolo Bonzini --iterator->level; 2269c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2270c50d8ae3SPaolo Bonzini iterator->level = 0; 2271c50d8ae3SPaolo Bonzini } 2272c50d8ae3SPaolo Bonzini } 2273c50d8ae3SPaolo Bonzini 2274c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2275c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2276c50d8ae3SPaolo Bonzini { 2277b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2278c50d8ae3SPaolo Bonzini addr); 2279c50d8ae3SPaolo Bonzini } 2280c50d8ae3SPaolo Bonzini 2281c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2282c50d8ae3SPaolo Bonzini { 22833bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2284c50d8ae3SPaolo Bonzini return false; 2285c50d8ae3SPaolo Bonzini 22862ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2287c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2288c50d8ae3SPaolo Bonzini return true; 2289c50d8ae3SPaolo Bonzini } 2290c50d8ae3SPaolo Bonzini 2291c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2292c50d8ae3SPaolo Bonzini u64 spte) 2293c50d8ae3SPaolo Bonzini { 22943e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2295c50d8ae3SPaolo Bonzini iterator->level = 0; 2296c50d8ae3SPaolo Bonzini return; 2297c50d8ae3SPaolo Bonzini } 2298c50d8ae3SPaolo Bonzini 22992ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2300c50d8ae3SPaolo Bonzini --iterator->level; 2301c50d8ae3SPaolo Bonzini } 2302c50d8ae3SPaolo Bonzini 2303c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2304c50d8ae3SPaolo Bonzini { 2305c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2306c50d8ae3SPaolo Bonzini } 2307c50d8ae3SPaolo Bonzini 23080cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 23090cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 231003787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2311c50d8ae3SPaolo Bonzini { 2312c50d8ae3SPaolo Bonzini u64 spte; 2313c50d8ae3SPaolo Bonzini 2314c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2315c50d8ae3SPaolo Bonzini 23160cd8dc73SPaolo Bonzini /* 23170cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 231803787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 231903787394SPaolo Bonzini * installing sp. 23200cd8dc73SPaolo Bonzini */ 23210cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 232203787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 23230cd8dc73SPaolo Bonzini 2324cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2325c50d8ae3SPaolo Bonzini 2326c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2327c50d8ae3SPaolo Bonzini 23282ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2329c50d8ae3SPaolo Bonzini 2330c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2331c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2332c50d8ae3SPaolo Bonzini } 2333c50d8ae3SPaolo Bonzini 23342ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 23352ff9039aSDavid Matlack struct kvm_mmu_page *sp) 23362ff9039aSDavid Matlack { 233703787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 23382ff9039aSDavid Matlack } 23392ff9039aSDavid Matlack 2340c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2341c50d8ae3SPaolo Bonzini unsigned direct_access) 2342c50d8ae3SPaolo Bonzini { 2343c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2344c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2345c50d8ae3SPaolo Bonzini 2346c50d8ae3SPaolo Bonzini /* 2347c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2348c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2349c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2350c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2351c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2352c50d8ae3SPaolo Bonzini */ 23532ca3129eSSean Christopherson child = to_shadow_page(*sptep & SPTE_BASE_ADDR_MASK); 2354c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2355c50d8ae3SPaolo Bonzini return; 2356c50d8ae3SPaolo Bonzini 2357c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2358c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2359c50d8ae3SPaolo Bonzini } 2360c50d8ae3SPaolo Bonzini } 2361c50d8ae3SPaolo Bonzini 23622de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 23632de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 23642de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2365c50d8ae3SPaolo Bonzini { 2366c50d8ae3SPaolo Bonzini u64 pte; 2367c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2368c50d8ae3SPaolo Bonzini 2369c50d8ae3SPaolo Bonzini pte = *spte; 2370c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2371c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2372c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2373c50d8ae3SPaolo Bonzini } else { 23742ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2375c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 23762de4085cSBen Gardon 23772de4085cSBen Gardon /* 23782de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 23792de4085cSBen Gardon * unlikely to be used again in the near future. This 23802de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 23812de4085cSBen Gardon */ 23822de4085cSBen Gardon if (tdp_enabled && invalid_list && 23832de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 23842de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 23852de4085cSBen Gardon invalid_list); 2386c50d8ae3SPaolo Bonzini } 2387ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2388c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2389ace569e0SSean Christopherson } 23902de4085cSBen Gardon return 0; 2391c50d8ae3SPaolo Bonzini } 2392c50d8ae3SPaolo Bonzini 23932de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 23942de4085cSBen Gardon struct kvm_mmu_page *sp, 23952de4085cSBen Gardon struct list_head *invalid_list) 2396c50d8ae3SPaolo Bonzini { 23972de4085cSBen Gardon int zapped = 0; 2398c50d8ae3SPaolo Bonzini unsigned i; 2399c50d8ae3SPaolo Bonzini 24002ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 24012de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 24022de4085cSBen Gardon 24032de4085cSBen Gardon return zapped; 2404c50d8ae3SPaolo Bonzini } 2405c50d8ae3SPaolo Bonzini 240661827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2407c50d8ae3SPaolo Bonzini { 2408c50d8ae3SPaolo Bonzini u64 *sptep; 2409c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2410c50d8ae3SPaolo Bonzini 2411c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2412c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2413c50d8ae3SPaolo Bonzini } 2414c50d8ae3SPaolo Bonzini 2415c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2416c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2417c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2418c50d8ae3SPaolo Bonzini { 2419c50d8ae3SPaolo Bonzini int i, zapped = 0; 2420c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2421c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2422c50d8ae3SPaolo Bonzini 24233bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2424c50d8ae3SPaolo Bonzini return 0; 2425c50d8ae3SPaolo Bonzini 2426c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2427c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2428c50d8ae3SPaolo Bonzini 2429c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2430c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2431c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2432c50d8ae3SPaolo Bonzini zapped++; 2433c50d8ae3SPaolo Bonzini } 2434c50d8ae3SPaolo Bonzini } 2435c50d8ae3SPaolo Bonzini 2436c50d8ae3SPaolo Bonzini return zapped; 2437c50d8ae3SPaolo Bonzini } 2438c50d8ae3SPaolo Bonzini 2439c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2440c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2441c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2442c50d8ae3SPaolo Bonzini int *nr_zapped) 2443c50d8ae3SPaolo Bonzini { 2444527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2445c50d8ae3SPaolo Bonzini 2446c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2447c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2448c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 24492de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 245061827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2451c50d8ae3SPaolo Bonzini 2452c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2453c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2454c50d8ae3SPaolo Bonzini 2455767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2456c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2457c50d8ae3SPaolo Bonzini 2458c50d8ae3SPaolo Bonzini if (sp->unsync) 2459c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2460c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2461c50d8ae3SPaolo Bonzini /* Count self */ 2462c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2463f95eec9bSSean Christopherson 2464f95eec9bSSean Christopherson /* 2465f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2466f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2467f95eec9bSSean Christopherson * !sp->root_count. 2468f95eec9bSSean Christopherson */ 2469f95eec9bSSean Christopherson if (sp->role.invalid) 2470f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2471f95eec9bSSean Christopherson else 2472c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 247343a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2474c50d8ae3SPaolo Bonzini } else { 2475f95eec9bSSean Christopherson /* 2476f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2477f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2478f95eec9bSSean Christopherson */ 2479f95eec9bSSean Christopherson list_del(&sp->link); 2480c50d8ae3SPaolo Bonzini 2481c50d8ae3SPaolo Bonzini /* 2482c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2483c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2484c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2485c50d8ae3SPaolo Bonzini */ 2486527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2487c50d8ae3SPaolo Bonzini } 2488c50d8ae3SPaolo Bonzini 2489c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2490c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2491c50d8ae3SPaolo Bonzini 2492c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2493527d5cd7SSean Christopherson 2494527d5cd7SSean Christopherson /* 2495527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2496527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2497527d5cd7SSean Christopherson */ 2498527d5cd7SSean Christopherson if (zapped_root) 2499527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2500c50d8ae3SPaolo Bonzini return list_unstable; 2501c50d8ae3SPaolo Bonzini } 2502c50d8ae3SPaolo Bonzini 2503c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2504c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2505c50d8ae3SPaolo Bonzini { 2506c50d8ae3SPaolo Bonzini int nr_zapped; 2507c50d8ae3SPaolo Bonzini 2508c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2509c50d8ae3SPaolo Bonzini return nr_zapped; 2510c50d8ae3SPaolo Bonzini } 2511c50d8ae3SPaolo Bonzini 2512c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2513c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2514c50d8ae3SPaolo Bonzini { 2515c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2516c50d8ae3SPaolo Bonzini 2517c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2518c50d8ae3SPaolo Bonzini return; 2519c50d8ae3SPaolo Bonzini 2520c50d8ae3SPaolo Bonzini /* 2521c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2522c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2523c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2524c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2525c50d8ae3SPaolo Bonzini * 2526c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2527c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2528c50d8ae3SPaolo Bonzini */ 2529c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2530c50d8ae3SPaolo Bonzini 2531c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2532c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 253387654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2534c50d8ae3SPaolo Bonzini } 2535c50d8ae3SPaolo Bonzini } 2536c50d8ae3SPaolo Bonzini 25376b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 25386b82ef2cSSean Christopherson unsigned long nr_to_zap) 2539c50d8ae3SPaolo Bonzini { 25406b82ef2cSSean Christopherson unsigned long total_zapped = 0; 25416b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2542ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 25436b82ef2cSSean Christopherson bool unstable; 25446b82ef2cSSean Christopherson int nr_zapped; 2545c50d8ae3SPaolo Bonzini 2546c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2547ba7888ddSSean Christopherson return 0; 2548c50d8ae3SPaolo Bonzini 25496b82ef2cSSean Christopherson restart: 25508fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 25516b82ef2cSSean Christopherson /* 25526b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 25536b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 25546b82ef2cSSean Christopherson */ 25556b82ef2cSSean Christopherson if (sp->root_count) 25566b82ef2cSSean Christopherson continue; 25576b82ef2cSSean Christopherson 25586b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 25596b82ef2cSSean Christopherson &nr_zapped); 25606b82ef2cSSean Christopherson total_zapped += nr_zapped; 25616b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2562ba7888ddSSean Christopherson break; 2563ba7888ddSSean Christopherson 25646b82ef2cSSean Christopherson if (unstable) 25656b82ef2cSSean Christopherson goto restart; 2566ba7888ddSSean Christopherson } 25676b82ef2cSSean Christopherson 25686b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 25696b82ef2cSSean Christopherson 25706b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 25716b82ef2cSSean Christopherson return total_zapped; 25726b82ef2cSSean Christopherson } 25736b82ef2cSSean Christopherson 2574afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2575afe8d7e6SSean Christopherson { 2576afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2577afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2578afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2579afe8d7e6SSean Christopherson 2580afe8d7e6SSean Christopherson return 0; 2581c50d8ae3SPaolo Bonzini } 2582c50d8ae3SPaolo Bonzini 2583ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2584ba7888ddSSean Christopherson { 25856b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2586ba7888ddSSean Christopherson 25876b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2588ba7888ddSSean Christopherson return 0; 2589ba7888ddSSean Christopherson 25906b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2591ba7888ddSSean Christopherson 25926e6ec584SSean Christopherson /* 25936e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 25946e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 25956e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 25966e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2597c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 25986e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 25996e6ec584SSean Christopherson * page fault paths. 26006e6ec584SSean Christopherson */ 2601ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2602ba7888ddSSean Christopherson return -ENOSPC; 2603ba7888ddSSean Christopherson return 0; 2604ba7888ddSSean Christopherson } 2605ba7888ddSSean Christopherson 2606c50d8ae3SPaolo Bonzini /* 2607c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2608c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2609c50d8ae3SPaolo Bonzini */ 2610c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2611c50d8ae3SPaolo Bonzini { 2612531810caSBen Gardon write_lock(&kvm->mmu_lock); 2613c50d8ae3SPaolo Bonzini 2614c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 26156b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 26166b82ef2cSSean Christopherson goal_nr_mmu_pages); 2617c50d8ae3SPaolo Bonzini 2618c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2619c50d8ae3SPaolo Bonzini } 2620c50d8ae3SPaolo Bonzini 2621c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2622c50d8ae3SPaolo Bonzini 2623531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2624c50d8ae3SPaolo Bonzini } 2625c50d8ae3SPaolo Bonzini 2626c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2627c50d8ae3SPaolo Bonzini { 2628c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2629c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2630c50d8ae3SPaolo Bonzini int r; 2631c50d8ae3SPaolo Bonzini 2632c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2633c50d8ae3SPaolo Bonzini r = 0; 2634531810caSBen Gardon write_lock(&kvm->mmu_lock); 2635767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2636c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2637c50d8ae3SPaolo Bonzini sp->role.word); 2638c50d8ae3SPaolo Bonzini r = 1; 2639c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2640c50d8ae3SPaolo Bonzini } 2641c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2642531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2643c50d8ae3SPaolo Bonzini 2644c50d8ae3SPaolo Bonzini return r; 2645c50d8ae3SPaolo Bonzini } 264696ad91aeSSean Christopherson 264796ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 264896ad91aeSSean Christopherson { 264996ad91aeSSean Christopherson gpa_t gpa; 265096ad91aeSSean Christopherson int r; 265196ad91aeSSean Christopherson 2652347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 265396ad91aeSSean Christopherson return 0; 265496ad91aeSSean Christopherson 265596ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 265696ad91aeSSean Christopherson 265796ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 265896ad91aeSSean Christopherson 265996ad91aeSSean Christopherson return r; 266096ad91aeSSean Christopherson } 2661c50d8ae3SPaolo Bonzini 26624d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2663c50d8ae3SPaolo Bonzini { 2664c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 26654d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2666c50d8ae3SPaolo Bonzini sp->unsync = 1; 2667c50d8ae3SPaolo Bonzini 2668c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2669c50d8ae3SPaolo Bonzini } 2670c50d8ae3SPaolo Bonzini 26710337f585SSean Christopherson /* 26720337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 26730337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 26740337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 26750337f585SSean Christopherson * be write-protected. 26760337f585SSean Christopherson */ 26778283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 26782839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2679c50d8ae3SPaolo Bonzini { 2680c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2681ce25681dSSean Christopherson bool locked = false; 2682c50d8ae3SPaolo Bonzini 26830337f585SSean Christopherson /* 26840337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 26850337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 26860337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 26870337f585SSean Christopherson */ 26884d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 26890337f585SSean Christopherson return -EPERM; 2690c50d8ae3SPaolo Bonzini 26910337f585SSean Christopherson /* 26920337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 26930337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 26940337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 26950337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 26960337f585SSean Christopherson */ 2697767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2698c50d8ae3SPaolo Bonzini if (!can_unsync) 26990337f585SSean Christopherson return -EPERM; 2700c50d8ae3SPaolo Bonzini 2701c50d8ae3SPaolo Bonzini if (sp->unsync) 2702c50d8ae3SPaolo Bonzini continue; 2703c50d8ae3SPaolo Bonzini 27042839180cSPaolo Bonzini if (prefetch) 2705f1c4a88cSLai Jiangshan return -EEXIST; 2706f1c4a88cSLai Jiangshan 2707ce25681dSSean Christopherson /* 2708ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2709ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2710ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2711ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2712ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2713ce25681dSSean Christopherson */ 2714ce25681dSSean Christopherson if (!locked) { 2715ce25681dSSean Christopherson locked = true; 27164d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2717ce25681dSSean Christopherson 2718ce25681dSSean Christopherson /* 2719ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2720ce25681dSSean Christopherson * may have since marked the page unsync. A false 2721ce25681dSSean Christopherson * positive on the unprotected check above is not 2722ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2723ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2724ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2725ce25681dSSean Christopherson */ 2726ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2727ce25681dSSean Christopherson continue; 2728ce25681dSSean Christopherson } 2729ce25681dSSean Christopherson 27303bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 27314d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2732c50d8ae3SPaolo Bonzini } 2733ce25681dSSean Christopherson if (locked) 27344d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2735c50d8ae3SPaolo Bonzini 2736c50d8ae3SPaolo Bonzini /* 2737c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2738c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2739c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2740c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2741c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2742c50d8ae3SPaolo Bonzini * following could happen: 2743c50d8ae3SPaolo Bonzini * 2744c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2745c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2746c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2747c50d8ae3SPaolo Bonzini * to be writable 2748c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2749c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2750c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2751c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2752c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2753c50d8ae3SPaolo Bonzini * fault. 2754c50d8ae3SPaolo Bonzini * 2755c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2756c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2757c50d8ae3SPaolo Bonzini * 27580337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 27590337f585SSean Christopherson * false and skips the page. 2760c50d8ae3SPaolo Bonzini * 2761c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2762c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2763c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2764c50d8ae3SPaolo Bonzini * gets used. 2765c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2766c50d8ae3SPaolo Bonzini * as unsync 2767c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2768c50d8ae3SPaolo Bonzini * 2769c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2770264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2771264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2772c50d8ae3SPaolo Bonzini */ 2773c50d8ae3SPaolo Bonzini smp_wmb(); 2774c50d8ae3SPaolo Bonzini 27750337f585SSean Christopherson return 0; 2776c50d8ae3SPaolo Bonzini } 2777c50d8ae3SPaolo Bonzini 27788a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 27798a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2780a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2781799a4190SBen Gardon { 2782d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2783eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2784c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2785c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2786c50d8ae3SPaolo Bonzini bool flush = false; 2787ad67e480SPaolo Bonzini bool wrprot; 2788d786c778SPaolo Bonzini u64 spte; 2789c50d8ae3SPaolo Bonzini 2790a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2791a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 27922839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2793a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2794c50d8ae3SPaolo Bonzini 2795c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2796c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2797c50d8ae3SPaolo Bonzini 2798a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 27991075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2800a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2801a54aa15cSSean Christopherson return RET_PF_EMULATE; 2802a54aa15cSSean Christopherson } 2803a54aa15cSSean Christopherson 2804c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2805c50d8ae3SPaolo Bonzini /* 2806c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2807c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2808c50d8ae3SPaolo Bonzini */ 28093bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2810c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2811c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2812c50d8ae3SPaolo Bonzini 28132ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2814c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2815c50d8ae3SPaolo Bonzini flush = true; 2816c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2817c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2818c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2819c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2820c50d8ae3SPaolo Bonzini flush = true; 2821c50d8ae3SPaolo Bonzini } else 2822c50d8ae3SPaolo Bonzini was_rmapped = 1; 2823c50d8ae3SPaolo Bonzini } 2824c50d8ae3SPaolo Bonzini 28252839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 28267158bee4SPaolo Bonzini true, host_writable, &spte); 2827d786c778SPaolo Bonzini 2828d786c778SPaolo Bonzini if (*sptep == spte) { 2829d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2830d786c778SPaolo Bonzini } else { 2831d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 28325959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2833c50d8ae3SPaolo Bonzini } 2834c50d8ae3SPaolo Bonzini 2835ad67e480SPaolo Bonzini if (wrprot) { 2836c50d8ae3SPaolo Bonzini if (write_fault) 2837c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2838c50d8ae3SPaolo Bonzini } 2839c50d8ae3SPaolo Bonzini 2840d786c778SPaolo Bonzini if (flush) 2841c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2842c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2843c50d8ae3SPaolo Bonzini 2844c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2845c50d8ae3SPaolo Bonzini 2846c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2847d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 28486a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 28496a97575dSDavid Matlack } else { 28506a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 285179e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2852c50d8ae3SPaolo Bonzini } 2853c50d8ae3SPaolo Bonzini 2854c50d8ae3SPaolo Bonzini return ret; 2855c50d8ae3SPaolo Bonzini } 2856c50d8ae3SPaolo Bonzini 2857c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2858c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2859c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2860c50d8ae3SPaolo Bonzini { 2861c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2862c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 28630a2b64c5SBen Gardon unsigned int access = sp->role.access; 2864c50d8ae3SPaolo Bonzini int i, ret; 2865c50d8ae3SPaolo Bonzini gfn_t gfn; 2866c50d8ae3SPaolo Bonzini 286779e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 2868c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2869c50d8ae3SPaolo Bonzini if (!slot) 2870c50d8ae3SPaolo Bonzini return -1; 2871c50d8ae3SPaolo Bonzini 2872c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2873c50d8ae3SPaolo Bonzini if (ret <= 0) 2874c50d8ae3SPaolo Bonzini return -1; 2875c50d8ae3SPaolo Bonzini 2876c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 28778a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2878a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2879c50d8ae3SPaolo Bonzini put_page(pages[i]); 2880c50d8ae3SPaolo Bonzini } 2881c50d8ae3SPaolo Bonzini 2882c50d8ae3SPaolo Bonzini return 0; 2883c50d8ae3SPaolo Bonzini } 2884c50d8ae3SPaolo Bonzini 2885c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2886c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2887c50d8ae3SPaolo Bonzini { 2888c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2889c50d8ae3SPaolo Bonzini int i; 2890c50d8ae3SPaolo Bonzini 2891c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2892c50d8ae3SPaolo Bonzini 289379e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 2894c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2895c50d8ae3SPaolo Bonzini 2896c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2897c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2898c50d8ae3SPaolo Bonzini if (!start) 2899c50d8ae3SPaolo Bonzini continue; 2900c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2901c6cecc4bSSean Christopherson return; 2902c50d8ae3SPaolo Bonzini start = NULL; 2903c50d8ae3SPaolo Bonzini } else if (!start) 2904c50d8ae3SPaolo Bonzini start = spte; 2905c50d8ae3SPaolo Bonzini } 2906c6cecc4bSSean Christopherson if (start) 2907c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2908c50d8ae3SPaolo Bonzini } 2909c50d8ae3SPaolo Bonzini 2910c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2911c50d8ae3SPaolo Bonzini { 2912c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2913c50d8ae3SPaolo Bonzini 291457354682SSean Christopherson sp = sptep_to_sp(sptep); 2915c50d8ae3SPaolo Bonzini 2916c50d8ae3SPaolo Bonzini /* 2917c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2918c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2919c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2920c50d8ae3SPaolo Bonzini */ 2921c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2922c50d8ae3SPaolo Bonzini return; 2923c50d8ae3SPaolo Bonzini 29243bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2925c50d8ae3SPaolo Bonzini return; 2926c50d8ae3SPaolo Bonzini 29274a42d848SDavid Stevens /* 29284a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 29294a42d848SDavid Stevens * accidentally prefetching those addresses. 29304a42d848SDavid Stevens */ 293120ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 29324a42d848SDavid Stevens return; 29334a42d848SDavid Stevens 2934c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2935c50d8ae3SPaolo Bonzini } 2936c50d8ae3SPaolo Bonzini 293765e3b446SSean Christopherson /* 293865e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 293965e3b446SSean Christopherson * 294065e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 294165e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 294265e3b446SSean Christopherson * 294365e3b446SSean Christopherson * There are several ways to safely use this helper: 294465e3b446SSean Christopherson * 294520ec3ebdSChao Peng * - Check mmu_invalidate_retry_hva() after grabbing the mapping level, before 294665e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 294765e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 294865e3b446SSean Christopherson * 294965e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 295065e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 295165e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 295265e3b446SSean Christopherson * 295365e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 295465e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 295565e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 295665e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 295765e3b446SSean Christopherson * 295865e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 295965e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 296065e3b446SSean Christopherson * race with the primary MMU occurs. 296165e3b446SSean Christopherson */ 2962a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 29638ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2964db543216SSean Christopherson { 2965284dc493SSean Christopherson int level = PG_LEVEL_4K; 2966db543216SSean Christopherson unsigned long hva; 296744187235SMingwei Zhang unsigned long flags; 296844187235SMingwei Zhang pgd_t pgd; 296944187235SMingwei Zhang p4d_t p4d; 297044187235SMingwei Zhang pud_t pud; 297144187235SMingwei Zhang pmd_t pmd; 2972db543216SSean Christopherson 29735d49f08cSSean Christopherson /* 2974293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2975293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2976293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2977293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2978293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2979293e306eSSean Christopherson * read-only memslot. 2980293e306eSSean Christopherson */ 2981db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2982db543216SSean Christopherson 298344187235SMingwei Zhang /* 298465e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 298565e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 298665e3b446SSean Christopherson * the original page table. 298744187235SMingwei Zhang */ 298844187235SMingwei Zhang local_irq_save(flags); 2989db543216SSean Christopherson 299065e3b446SSean Christopherson /* 299165e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 299265e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 299365e3b446SSean Christopherson * walk into the weeks, e.g. p*d_large() returns false (sees the old 299465e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 299565e3b446SSean Christopherson * of the old page table (sees the new value). 299665e3b446SSean Christopherson */ 299744187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 299844187235SMingwei Zhang if (pgd_none(pgd)) 299944187235SMingwei Zhang goto out; 300044187235SMingwei Zhang 300144187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 300244187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 300344187235SMingwei Zhang goto out; 300444187235SMingwei Zhang 300544187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 300644187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 300744187235SMingwei Zhang goto out; 300844187235SMingwei Zhang 300944187235SMingwei Zhang if (pud_large(pud)) { 301044187235SMingwei Zhang level = PG_LEVEL_1G; 301144187235SMingwei Zhang goto out; 301244187235SMingwei Zhang } 301344187235SMingwei Zhang 301444187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 301544187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 301644187235SMingwei Zhang goto out; 301744187235SMingwei Zhang 301844187235SMingwei Zhang if (pmd_large(pmd)) 301944187235SMingwei Zhang level = PG_LEVEL_2M; 302044187235SMingwei Zhang 302144187235SMingwei Zhang out: 302244187235SMingwei Zhang local_irq_restore(flags); 3023db543216SSean Christopherson return level; 3024db543216SSean Christopherson } 3025db543216SSean Christopherson 30268ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 30278ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 3028a8ac499bSSean Christopherson int max_level) 30291b6d9d9eSSean Christopherson { 30301b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3031ec607a56SPaolo Bonzini int host_level; 30321b6d9d9eSSean Christopherson 30331b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 30341b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 30351b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 30361b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 30371b6d9d9eSSean Christopherson break; 30381b6d9d9eSSean Christopherson } 30391b6d9d9eSSean Christopherson 30401b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 30411b6d9d9eSSean Christopherson return PG_LEVEL_4K; 30421b6d9d9eSSean Christopherson 3043a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3044ec607a56SPaolo Bonzini return min(host_level, max_level); 30451b6d9d9eSSean Christopherson } 30461b6d9d9eSSean Christopherson 304773a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 30480885904dSSean Christopherson { 3049e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 305017eff019SSean Christopherson kvm_pfn_t mask; 30510885904dSSean Christopherson 305273a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 30533cf06612SSean Christopherson 305473a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 305573a3c659SPaolo Bonzini return; 305617eff019SSean Christopherson 30575d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 305873a3c659SPaolo Bonzini return; 305917eff019SSean Christopherson 3060e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 306173a3c659SPaolo Bonzini return; 3062293e306eSSean Christopherson 30633cf06612SSean Christopherson /* 30643cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 30653cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 30663cf06612SSean Christopherson */ 306773a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 3068a8ac499bSSean Christopherson fault->gfn, fault->max_level); 306973a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 307073a3c659SPaolo Bonzini return; 30714cd071d1SSean Christopherson 30720885904dSSean Christopherson /* 307320ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 30744cd071d1SSean Christopherson * the pmd can't be split from under us. 30750885904dSSean Christopherson */ 307673a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 307773a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 307873a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 307973a3c659SPaolo Bonzini fault->pfn &= ~mask; 30800885904dSSean Christopherson } 30810885904dSSean Christopherson 3082536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3083c50d8ae3SPaolo Bonzini { 3084536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3085536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3086c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 3087c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 3088c50d8ae3SPaolo Bonzini /* 3089c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 3090c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 3091c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 3092c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 3093c50d8ae3SPaolo Bonzini * the address. 3094c50d8ae3SPaolo Bonzini */ 3095536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3096536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3097536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3098536f0e6aSPaolo Bonzini fault->goal_level--; 3099c50d8ae3SPaolo Bonzini } 3100c50d8ae3SPaolo Bonzini } 3101c50d8ae3SPaolo Bonzini 310243b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3103c50d8ae3SPaolo Bonzini { 3104c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3105c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 310673a3c659SPaolo Bonzini int ret; 310743b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3108c50d8ae3SPaolo Bonzini 310973a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 31104cd071d1SSean Christopherson 3111f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 311243b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3113c50d8ae3SPaolo Bonzini /* 3114c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3115c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3116c50d8ae3SPaolo Bonzini */ 311773a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3118536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3119c50d8ae3SPaolo Bonzini 312043b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 312173a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3122c50d8ae3SPaolo Bonzini break; 3123c50d8ae3SPaolo Bonzini 31242e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 31250cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 31260cd8dc73SPaolo Bonzini continue; 3127c50d8ae3SPaolo Bonzini 3128c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 312973a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 313073a3c659SPaolo Bonzini fault->req_level >= it.level) 3131c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 3132c50d8ae3SPaolo Bonzini } 3133c50d8ae3SPaolo Bonzini 3134b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3135b1a429fbSSean Christopherson return -EFAULT; 3136b1a429fbSSean Christopherson 31378a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3138a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 313912703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 314012703759SSean Christopherson return ret; 314112703759SSean Christopherson 3142c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3143c50d8ae3SPaolo Bonzini return ret; 3144c50d8ae3SPaolo Bonzini } 3145c50d8ae3SPaolo Bonzini 3146c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 3147c50d8ae3SPaolo Bonzini { 3148c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 3149c50d8ae3SPaolo Bonzini } 3150c50d8ae3SPaolo Bonzini 3151c50d8ae3SPaolo Bonzini static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 3152c50d8ae3SPaolo Bonzini { 3153c50d8ae3SPaolo Bonzini /* 3154c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3155c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3156c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3157c50d8ae3SPaolo Bonzini */ 3158c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3159c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3160c50d8ae3SPaolo Bonzini 3161c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3162c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3163c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3164c50d8ae3SPaolo Bonzini } 3165c50d8ae3SPaolo Bonzini 3166c50d8ae3SPaolo Bonzini return -EFAULT; 3167c50d8ae3SPaolo Bonzini } 3168c50d8ae3SPaolo Bonzini 31695276c616SSean Christopherson static int handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 31705276c616SSean Christopherson unsigned int access) 3171c50d8ae3SPaolo Bonzini { 3172c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 31735276c616SSean Christopherson if (unlikely(is_error_pfn(fault->pfn))) 31745276c616SSean Christopherson return kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); 3175c50d8ae3SPaolo Bonzini 3176e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 31773a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 31783a13f4feSPaolo Bonzini 31793a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3180c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 318130ab5901SSean Christopherson /* 318230ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 318330ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 318486931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 318586931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 318686931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 318786931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 318886931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 318986931ff7SSean Christopherson * the hardware's). 319030ab5901SSean Christopherson */ 31918b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 31925276c616SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) 31935276c616SSean Christopherson return RET_PF_EMULATE; 319430ab5901SSean Christopherson } 3195c50d8ae3SPaolo Bonzini 31965276c616SSean Christopherson return RET_PF_CONTINUE; 3197c50d8ae3SPaolo Bonzini } 3198c50d8ae3SPaolo Bonzini 31993c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3200c50d8ae3SPaolo Bonzini { 3201c50d8ae3SPaolo Bonzini /* 32025c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 32035c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 32045c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 32055c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3206c50d8ae3SPaolo Bonzini */ 32073c8ad5a6SPaolo Bonzini if (fault->rsvd) 3208c50d8ae3SPaolo Bonzini return false; 3209c50d8ae3SPaolo Bonzini 3210c50d8ae3SPaolo Bonzini /* 3211c50d8ae3SPaolo Bonzini * #PF can be fast if: 3212c50d8ae3SPaolo Bonzini * 321354275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 321454275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 321554275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 321654275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 321754275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 321854275f74SSean Christopherson * mechanism only supports direct MMUs. 321954275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 322054275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 322154275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 322254275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 322354275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3224c50d8ae3SPaolo Bonzini */ 32255c64aba5SSean Christopherson if (!fault->present) 32265c64aba5SSean Christopherson return !kvm_ad_enabled(); 32275c64aba5SSean Christopherson 32285c64aba5SSean Christopherson /* 32295c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 32305c64aba5SSean Christopherson * the "exec" flag. 32315c64aba5SSean Christopherson */ 32325c64aba5SSean Christopherson return fault->write; 3233c50d8ae3SPaolo Bonzini } 3234c50d8ae3SPaolo Bonzini 3235c50d8ae3SPaolo Bonzini /* 3236c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3237c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3238c50d8ae3SPaolo Bonzini */ 3239c50d8ae3SPaolo Bonzini static bool 3240e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3241c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3242c50d8ae3SPaolo Bonzini { 3243c50d8ae3SPaolo Bonzini /* 3244c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3245c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3246c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3247c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3248c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3249c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3250c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3251c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3252c50d8ae3SPaolo Bonzini * 3253c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3254c50d8ae3SPaolo Bonzini */ 32552db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3256c50d8ae3SPaolo Bonzini return false; 3257c50d8ae3SPaolo Bonzini 3258e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3259e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3260c50d8ae3SPaolo Bonzini 3261c50d8ae3SPaolo Bonzini return true; 3262c50d8ae3SPaolo Bonzini } 3263c50d8ae3SPaolo Bonzini 32643c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3265c50d8ae3SPaolo Bonzini { 32663c8ad5a6SPaolo Bonzini if (fault->exec) 3267c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3268c50d8ae3SPaolo Bonzini 32693c8ad5a6SPaolo Bonzini if (fault->write) 3270c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3271c50d8ae3SPaolo Bonzini 3272c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3273c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3274c50d8ae3SPaolo Bonzini } 3275c50d8ae3SPaolo Bonzini 3276c50d8ae3SPaolo Bonzini /* 32776e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 32786e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 32796e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 32806e8eb206SDavid Matlack * 32816e8eb206SDavid Matlack * Contract: 32826e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 32836e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 32846e8eb206SDavid Matlack */ 32856e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 32866e8eb206SDavid Matlack { 32876e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 32886e8eb206SDavid Matlack u64 old_spte; 32896e8eb206SDavid Matlack u64 *sptep = NULL; 32906e8eb206SDavid Matlack 32916e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 32926e8eb206SDavid Matlack sptep = iterator.sptep; 32936e8eb206SDavid Matlack *spte = old_spte; 32946e8eb206SDavid Matlack } 32956e8eb206SDavid Matlack 32966e8eb206SDavid Matlack return sptep; 32976e8eb206SDavid Matlack } 32986e8eb206SDavid Matlack 32996e8eb206SDavid Matlack /* 3300c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3301c50d8ae3SPaolo Bonzini */ 33023c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3303c50d8ae3SPaolo Bonzini { 3304c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3305c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3306c50d8ae3SPaolo Bonzini u64 spte = 0ull; 33076e8eb206SDavid Matlack u64 *sptep = NULL; 3308c50d8ae3SPaolo Bonzini uint retry_count = 0; 3309c50d8ae3SPaolo Bonzini 33103c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3311c4371c2aSSean Christopherson return ret; 3312c50d8ae3SPaolo Bonzini 3313c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3314c50d8ae3SPaolo Bonzini 3315c50d8ae3SPaolo Bonzini do { 3316c50d8ae3SPaolo Bonzini u64 new_spte; 3317c50d8ae3SPaolo Bonzini 33186e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 33193c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 33206e8eb206SDavid Matlack else 33213c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3322c50d8ae3SPaolo Bonzini 3323ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3324ec89e643SSean Christopherson break; 3325ec89e643SSean Christopherson 33266e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3327c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3328c50d8ae3SPaolo Bonzini break; 3329c50d8ae3SPaolo Bonzini 3330c50d8ae3SPaolo Bonzini /* 3331c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3332c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3333c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3334c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3335c50d8ae3SPaolo Bonzini * current CPU took the fault. 3336c50d8ae3SPaolo Bonzini * 3337c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3338c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3339c50d8ae3SPaolo Bonzini */ 33403c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3341c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3342c50d8ae3SPaolo Bonzini break; 3343c50d8ae3SPaolo Bonzini } 3344c50d8ae3SPaolo Bonzini 3345c50d8ae3SPaolo Bonzini new_spte = spte; 3346c50d8ae3SPaolo Bonzini 334754275f74SSean Christopherson /* 334854275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 334954275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 335054275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 335154275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 335254275f74SSean Christopherson */ 335354275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3354c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3355c50d8ae3SPaolo Bonzini 3356c50d8ae3SPaolo Bonzini /* 335754275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 335854275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 335954275f74SSean Christopherson * that were write-protected for dirty-logging or access 336054275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 336154275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 336254275f74SSean Christopherson * The is_access_allowed() check above handles the common case 336354275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 336454275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 336554275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3366c50d8ae3SPaolo Bonzini */ 3367706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3368c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3369c50d8ae3SPaolo Bonzini 3370c50d8ae3SPaolo Bonzini /* 337110c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 337210c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 337310c30de0SJunaid Shahid * first page into the dirty-bitmap in 3374c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3375c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3376c50d8ae3SPaolo Bonzini * 3377c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3378c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3379c50d8ae3SPaolo Bonzini */ 338010c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 338110c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3382c50d8ae3SPaolo Bonzini break; 3383c50d8ae3SPaolo Bonzini } 3384c50d8ae3SPaolo Bonzini 3385c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3386c50d8ae3SPaolo Bonzini if (new_spte == spte || 33873c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3388c50d8ae3SPaolo Bonzini break; 3389c50d8ae3SPaolo Bonzini 3390c50d8ae3SPaolo Bonzini /* 3391c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3392c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 33933ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3394c50d8ae3SPaolo Bonzini */ 3395e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3396c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3397c50d8ae3SPaolo Bonzini break; 3398c4371c2aSSean Christopherson } 3399c50d8ae3SPaolo Bonzini 3400c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3401c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3402c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3403c50d8ae3SPaolo Bonzini break; 3404c50d8ae3SPaolo Bonzini } 3405c50d8ae3SPaolo Bonzini 3406c50d8ae3SPaolo Bonzini } while (true); 3407c50d8ae3SPaolo Bonzini 3408f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3409c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3410c50d8ae3SPaolo Bonzini 34111075d41eSSean Christopherson if (ret != RET_PF_INVALID) 34121075d41eSSean Christopherson vcpu->stat.pf_fast++; 34131075d41eSSean Christopherson 3414c4371c2aSSean Christopherson return ret; 3415c50d8ae3SPaolo Bonzini } 3416c50d8ae3SPaolo Bonzini 3417c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3418c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3419c50d8ae3SPaolo Bonzini { 3420c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3421c50d8ae3SPaolo Bonzini 3422c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3423c50d8ae3SPaolo Bonzini return; 3424c50d8ae3SPaolo Bonzini 34252ca3129eSSean Christopherson sp = to_shadow_page(*root_hpa & SPTE_BASE_ADDR_MASK); 34269191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 34279191b8f0SPaolo Bonzini return; 342802c00b3aSBen Gardon 3429897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 34306103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 343176eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3432c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3433c50d8ae3SPaolo Bonzini 3434c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3435c50d8ae3SPaolo Bonzini } 3436c50d8ae3SPaolo Bonzini 3437c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 34380c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3439c50d8ae3SPaolo Bonzini ulong roots_to_free) 3440c50d8ae3SPaolo Bonzini { 3441c50d8ae3SPaolo Bonzini int i; 3442c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3443594bef79SPaolo Bonzini bool free_active_root; 3444c50d8ae3SPaolo Bonzini 3445c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3446c50d8ae3SPaolo Bonzini 3447c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3448594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3449594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3450594bef79SPaolo Bonzini 3451594bef79SPaolo Bonzini if (!free_active_root) { 3452c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3453c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3454c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3455c50d8ae3SPaolo Bonzini break; 3456c50d8ae3SPaolo Bonzini 3457c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3458c50d8ae3SPaolo Bonzini return; 3459c50d8ae3SPaolo Bonzini } 3460c50d8ae3SPaolo Bonzini 3461531810caSBen Gardon write_lock(&kvm->mmu_lock); 3462c50d8ae3SPaolo Bonzini 3463c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3464c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 34654d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3466c50d8ae3SPaolo Bonzini &invalid_list); 3467c50d8ae3SPaolo Bonzini 3468c50d8ae3SPaolo Bonzini if (free_active_root) { 3469594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3470b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 347104d45551SSean Christopherson } else if (mmu->pae_root) { 3472c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3473c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3474c834e5e4SSean Christopherson continue; 3475c834e5e4SSean Christopherson 3476c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3477c50d8ae3SPaolo Bonzini &invalid_list); 3478c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3479c50d8ae3SPaolo Bonzini } 3480c50d8ae3SPaolo Bonzini } 3481b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3482b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3483c50d8ae3SPaolo Bonzini } 3484c50d8ae3SPaolo Bonzini 34854d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3486531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3487c50d8ae3SPaolo Bonzini } 3488c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3489c50d8ae3SPaolo Bonzini 34900c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 349125b62c62SSean Christopherson { 349225b62c62SSean Christopherson unsigned long roots_to_free = 0; 349325b62c62SSean Christopherson hpa_t root_hpa; 349425b62c62SSean Christopherson int i; 349525b62c62SSean Christopherson 349625b62c62SSean Christopherson /* 349725b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 349825b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 349925b62c62SSean Christopherson */ 35007a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 350125b62c62SSean Christopherson 350225b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 350325b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 350425b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 350525b62c62SSean Christopherson continue; 350625b62c62SSean Christopherson 350725b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 350825b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 350925b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 351025b62c62SSean Christopherson } 351125b62c62SSean Christopherson 35120c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 351325b62c62SSean Christopherson } 351425b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 351525b62c62SSean Christopherson 351625b62c62SSean Christopherson 3517c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3518c50d8ae3SPaolo Bonzini { 3519c50d8ae3SPaolo Bonzini int ret = 0; 3520c50d8ae3SPaolo Bonzini 3521995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3522c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3523c50d8ae3SPaolo Bonzini ret = 1; 3524c50d8ae3SPaolo Bonzini } 3525c50d8ae3SPaolo Bonzini 3526c50d8ae3SPaolo Bonzini return ret; 3527c50d8ae3SPaolo Bonzini } 3528c50d8ae3SPaolo Bonzini 35292e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 353086938ab6SDavid Matlack u8 level) 3531c50d8ae3SPaolo Bonzini { 35322e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3533c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 35348123f265SSean Christopherson 35352e65e842SDavid Matlack role.level = level; 35362e65e842SDavid Matlack role.quadrant = quadrant; 35372e65e842SDavid Matlack 35387f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 35397f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 35407f497775SDavid Matlack 354187654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 35428123f265SSean Christopherson ++sp->root_count; 35438123f265SSean Christopherson 35448123f265SSean Christopherson return __pa(sp->spt); 35458123f265SSean Christopherson } 35468123f265SSean Christopherson 35478123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 35488123f265SSean Christopherson { 3549b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3550a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 35518123f265SSean Christopherson hpa_t root; 3552c50d8ae3SPaolo Bonzini unsigned i; 35534a38162eSPaolo Bonzini int r; 35544a38162eSPaolo Bonzini 35554a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35564a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35574a38162eSPaolo Bonzini if (r < 0) 35584a38162eSPaolo Bonzini goto out_unlock; 3559c50d8ae3SPaolo Bonzini 3560897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 356102c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3562b9e5603cSPaolo Bonzini mmu->root.hpa = root; 356302c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 356486938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3565b9e5603cSPaolo Bonzini mmu->root.hpa = root; 35668123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 35674a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35684a38162eSPaolo Bonzini r = -EIO; 35694a38162eSPaolo Bonzini goto out_unlock; 35704a38162eSPaolo Bonzini } 357173ad1606SSean Christopherson 3572c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3573c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3574c50d8ae3SPaolo Bonzini 35757f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 35762e65e842SDavid Matlack PT32_ROOT_LEVEL); 357717e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3578d2263de1SYuan Yao shadow_me_value; 3579c50d8ae3SPaolo Bonzini } 3580b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 358173ad1606SSean Christopherson } else { 358273ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 35834a38162eSPaolo Bonzini r = -EIO; 35844a38162eSPaolo Bonzini goto out_unlock; 358573ad1606SSean Christopherson } 35863651c7fcSSean Christopherson 3587b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3588b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 35894a38162eSPaolo Bonzini out_unlock: 35904a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 35914a38162eSPaolo Bonzini return r; 3592c50d8ae3SPaolo Bonzini } 3593c50d8ae3SPaolo Bonzini 35941e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 35951e76a3ceSDavid Stevens { 35961e76a3ceSDavid Stevens struct kvm_memslots *slots; 35971e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3598a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 35991e76a3ceSDavid Stevens 36001e76a3ceSDavid Stevens /* 36011e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 36021e76a3ceSDavid Stevens * taking the lock. 36031e76a3ceSDavid Stevens */ 36041e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 36051e76a3ceSDavid Stevens return 0; 36061e76a3ceSDavid Stevens 36071e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 36081e76a3ceSDavid Stevens 36091e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 36101e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 36111e76a3ceSDavid Stevens goto out_unlock; 36121e76a3ceSDavid Stevens 36131e76a3ceSDavid Stevens /* 36141e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 36151e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 36161e76a3ceSDavid Stevens */ 36171e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 36181e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 36191e76a3ceSDavid Stevens goto out_success; 36201e76a3ceSDavid Stevens 36211e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 36221e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3623a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 36241e76a3ceSDavid Stevens /* 36251e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 36261e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 36271e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 36281e76a3ceSDavid Stevens * failure to avoid having to track which allocations 36291e76a3ceSDavid Stevens * were made now versus when the memslot was created. 36301e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 36311e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 36321e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 36331e76a3ceSDavid Stevens */ 36341e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 36351e76a3ceSDavid Stevens if (r) 36361e76a3ceSDavid Stevens goto out_unlock; 36371e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 36381e76a3ceSDavid Stevens if (r) 36391e76a3ceSDavid Stevens goto out_unlock; 36401e76a3ceSDavid Stevens } 36411e76a3ceSDavid Stevens } 36421e76a3ceSDavid Stevens 36431e76a3ceSDavid Stevens /* 36441e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 36451e76a3ceSDavid Stevens * all the related pointers are set. 36461e76a3ceSDavid Stevens */ 36471e76a3ceSDavid Stevens out_success: 36481e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 36491e76a3ceSDavid Stevens 36501e76a3ceSDavid Stevens out_unlock: 36511e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 36521e76a3ceSDavid Stevens return r; 36531e76a3ceSDavid Stevens } 36541e76a3ceSDavid Stevens 3655c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3656c50d8ae3SPaolo Bonzini { 3657b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 36586e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3659be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 36607f497775SDavid Matlack int quadrant, i, r; 36618123f265SSean Christopherson hpa_t root; 3662c50d8ae3SPaolo Bonzini 3663b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3664be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3665c50d8ae3SPaolo Bonzini 3666c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3667c50d8ae3SPaolo Bonzini return 1; 3668c50d8ae3SPaolo Bonzini 3669c50d8ae3SPaolo Bonzini /* 36704a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 36714a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 36724a38162eSPaolo Bonzini */ 36734d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 36746e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 36756e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 36766e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 36776e0918aeSSean Christopherson continue; 36786e0918aeSSean Christopherson 36796e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 36806e0918aeSSean Christopherson return 1; 36816e0918aeSSean Christopherson } 36826e0918aeSSean Christopherson } 36836e0918aeSSean Christopherson 36841e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3685d501f747SBen Gardon if (r) 3686d501f747SBen Gardon return r; 3687d501f747SBen Gardon 36884a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36894a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36904a38162eSPaolo Bonzini if (r < 0) 36914a38162eSPaolo Bonzini goto out_unlock; 36924a38162eSPaolo Bonzini 3693c50d8ae3SPaolo Bonzini /* 3694c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3695c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3696c50d8ae3SPaolo Bonzini */ 36974d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 36988123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 369986938ab6SDavid Matlack mmu->root_role.level); 3700b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3701be01e8e2SSean Christopherson goto set_root_pgd; 3702c50d8ae3SPaolo Bonzini } 3703c50d8ae3SPaolo Bonzini 37044a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 37054a38162eSPaolo Bonzini r = -EIO; 37064a38162eSPaolo Bonzini goto out_unlock; 37074a38162eSPaolo Bonzini } 370873ad1606SSean Christopherson 3709c50d8ae3SPaolo Bonzini /* 3710c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3711c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3712c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3713c50d8ae3SPaolo Bonzini */ 3714e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3715a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3716c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3717c50d8ae3SPaolo Bonzini 371803ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 37194a38162eSPaolo Bonzini r = -EIO; 37204a38162eSPaolo Bonzini goto out_unlock; 37214a38162eSPaolo Bonzini } 372203ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3723cb0f722aSWei Huang 3724a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3725cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3726cb0f722aSWei Huang r = -EIO; 3727cb0f722aSWei Huang goto out_unlock; 3728cb0f722aSWei Huang } 3729cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3730cb0f722aSWei Huang } 373104d45551SSean Christopherson } 373204d45551SSean Christopherson 3733c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3734c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 37356e6ec584SSean Christopherson 37364d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 37376e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3738c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3739c50d8ae3SPaolo Bonzini continue; 3740c50d8ae3SPaolo Bonzini } 37416e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3742c50d8ae3SPaolo Bonzini } 3743c50d8ae3SPaolo Bonzini 37447f497775SDavid Matlack /* 37457f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 37467f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 37477f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 37487f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 37497f497775SDavid Matlack */ 37507f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 37517f497775SDavid Matlack 37527f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3753b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3754c50d8ae3SPaolo Bonzini } 3755c50d8ae3SPaolo Bonzini 3756a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3757b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3758a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3759b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3760ba0a194fSSean Christopherson else 3761b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3762c50d8ae3SPaolo Bonzini 3763be01e8e2SSean Christopherson set_root_pgd: 3764b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 37654a38162eSPaolo Bonzini out_unlock: 37664a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3767c50d8ae3SPaolo Bonzini 3768c6c937d6SLike Xu return r; 3769c50d8ae3SPaolo Bonzini } 3770c50d8ae3SPaolo Bonzini 3771748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3772c50d8ae3SPaolo Bonzini { 3773748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3774a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3775cb0f722aSWei Huang u64 *pml5_root = NULL; 3776cb0f722aSWei Huang u64 *pml4_root = NULL; 3777cb0f722aSWei Huang u64 *pae_root; 3778748e52b9SSean Christopherson 3779748e52b9SSean Christopherson /* 3780748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3781748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3782748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3783748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3784748e52b9SSean Christopherson */ 3785347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3786347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3787a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3788748e52b9SSean Christopherson return 0; 3789748e52b9SSean Christopherson 3790a717a780SSean Christopherson /* 3791a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3792a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3793a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3794a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3795a717a780SSean Christopherson * prior MMU would also have required pml5. 3796a717a780SSean Christopherson */ 3797a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3798748e52b9SSean Christopherson return 0; 3799748e52b9SSean Christopherson 3800748e52b9SSean Christopherson /* 3801748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3802748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3803748e52b9SSean Christopherson */ 3804cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3805a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3806748e52b9SSean Christopherson return -EIO; 3807748e52b9SSean Christopherson 38084a98623dSSean Christopherson /* 38094a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 38104a98623dSSean Christopherson * doesn't need to be decrypted. 38114a98623dSSean Christopherson */ 3812748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3813748e52b9SSean Christopherson if (!pae_root) 3814748e52b9SSean Christopherson return -ENOMEM; 3815748e52b9SSean Christopherson 3816cb0f722aSWei Huang #ifdef CONFIG_X86_64 381703ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3818cb0f722aSWei Huang if (!pml4_root) 3819cb0f722aSWei Huang goto err_pml4; 3820cb0f722aSWei Huang 3821a717a780SSean Christopherson if (need_pml5) { 3822cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3823cb0f722aSWei Huang if (!pml5_root) 3824cb0f722aSWei Huang goto err_pml5; 3825748e52b9SSean Christopherson } 3826cb0f722aSWei Huang #endif 3827748e52b9SSean Christopherson 3828748e52b9SSean Christopherson mmu->pae_root = pae_root; 382903ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3830cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3831748e52b9SSean Christopherson 3832748e52b9SSean Christopherson return 0; 3833cb0f722aSWei Huang 3834cb0f722aSWei Huang #ifdef CONFIG_X86_64 3835cb0f722aSWei Huang err_pml5: 3836cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3837cb0f722aSWei Huang err_pml4: 3838cb0f722aSWei Huang free_page((unsigned long)pae_root); 3839cb0f722aSWei Huang return -ENOMEM; 3840cb0f722aSWei Huang #endif 3841c50d8ae3SPaolo Bonzini } 3842c50d8ae3SPaolo Bonzini 3843264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3844264d3dc1SLai Jiangshan { 3845264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3846264d3dc1SLai Jiangshan 384761b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 384861b05a9fSLai Jiangshan return false; 384961b05a9fSLai Jiangshan 3850264d3dc1SLai Jiangshan /* 3851264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3852264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3853264d3dc1SLai Jiangshan * 3854264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3855264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3856264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3857264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3858264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3859264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3860264d3dc1SLai Jiangshan * requirement isn't satisfied. 3861264d3dc1SLai Jiangshan */ 3862264d3dc1SLai Jiangshan smp_rmb(); 3863264d3dc1SLai Jiangshan sp = to_shadow_page(root); 38645d6a3221SSean Christopherson 38655d6a3221SSean Christopherson /* 38665d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 38675d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 38685d6a3221SSean Christopherson */ 38695d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 38705d6a3221SSean Christopherson return false; 38715d6a3221SSean Christopherson 3872264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3873264d3dc1SLai Jiangshan return true; 3874264d3dc1SLai Jiangshan 3875264d3dc1SLai Jiangshan return false; 3876264d3dc1SLai Jiangshan } 3877264d3dc1SLai Jiangshan 3878c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3879c50d8ae3SPaolo Bonzini { 3880c50d8ae3SPaolo Bonzini int i; 3881c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3882c50d8ae3SPaolo Bonzini 3883347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3884c50d8ae3SPaolo Bonzini return; 3885c50d8ae3SPaolo Bonzini 3886b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3887c50d8ae3SPaolo Bonzini return; 3888c50d8ae3SPaolo Bonzini 3889c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3890c50d8ae3SPaolo Bonzini 38914d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3892b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3893e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3894c50d8ae3SPaolo Bonzini 3895264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3896c50d8ae3SPaolo Bonzini return; 3897c50d8ae3SPaolo Bonzini 3898531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 389965855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3900531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3901c50d8ae3SPaolo Bonzini return; 3902c50d8ae3SPaolo Bonzini } 3903c50d8ae3SPaolo Bonzini 3904531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3905c50d8ae3SPaolo Bonzini 3906c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3907c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3908c50d8ae3SPaolo Bonzini 3909c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 39102ca3129eSSean Christopherson root &= SPTE_BASE_ADDR_MASK; 3911e47c4aeeSSean Christopherson sp = to_shadow_page(root); 391265855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3913c50d8ae3SPaolo Bonzini } 3914c50d8ae3SPaolo Bonzini } 3915c50d8ae3SPaolo Bonzini 3916531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3917c50d8ae3SPaolo Bonzini } 3918c50d8ae3SPaolo Bonzini 391961b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 392061b05a9fSLai Jiangshan { 392161b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 392261b05a9fSLai Jiangshan int i; 392361b05a9fSLai Jiangshan 392461b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 392561b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 392661b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 392761b05a9fSLai Jiangshan 392861b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 39290c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 393061b05a9fSLai Jiangshan } 393161b05a9fSLai Jiangshan 39321f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 39335b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3934c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3935c50d8ae3SPaolo Bonzini { 3936c50d8ae3SPaolo Bonzini if (exception) 3937c50d8ae3SPaolo Bonzini exception->error_code = 0; 3938c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3939c50d8ae3SPaolo Bonzini } 3940c50d8ae3SPaolo Bonzini 3941c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3942c50d8ae3SPaolo Bonzini { 3943c50d8ae3SPaolo Bonzini /* 3944c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3945c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3946c50d8ae3SPaolo Bonzini */ 3947c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3948c50d8ae3SPaolo Bonzini return false; 3949c50d8ae3SPaolo Bonzini 3950c50d8ae3SPaolo Bonzini if (direct) 3951c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3952c50d8ae3SPaolo Bonzini 3953c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3954c50d8ae3SPaolo Bonzini } 3955c50d8ae3SPaolo Bonzini 395695fb5b02SBen Gardon /* 395795fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 395895fb5b02SBen Gardon * That SPTE may be non-present. 3959c5c8c7c5SDavid Matlack * 3960c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 396195fb5b02SBen Gardon */ 396239b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3963c50d8ae3SPaolo Bonzini { 3964c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 39652aa07893SSean Christopherson int leaf = -1; 396695fb5b02SBen Gardon u64 spte; 3967c50d8ae3SPaolo Bonzini 396839b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 396939b4d43eSSean Christopherson *root_level = iterator.level; 3970c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3971c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 397295fb5b02SBen Gardon leaf = iterator.level; 3973c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3974c50d8ae3SPaolo Bonzini 3975dde81f94SSean Christopherson sptes[leaf] = spte; 397695fb5b02SBen Gardon } 397795fb5b02SBen Gardon 397895fb5b02SBen Gardon return leaf; 397995fb5b02SBen Gardon } 398095fb5b02SBen Gardon 39819aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 398295fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 398395fb5b02SBen Gardon { 3984dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 398595fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 398639b4d43eSSean Christopherson int root, leaf, level; 398795fb5b02SBen Gardon bool reserved = false; 398895fb5b02SBen Gardon 3989c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3990c5c8c7c5SDavid Matlack 399163c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 399239b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 399395fb5b02SBen Gardon else 399439b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 399595fb5b02SBen Gardon 3996c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 3997c5c8c7c5SDavid Matlack 39982aa07893SSean Christopherson if (unlikely(leaf < 0)) { 39992aa07893SSean Christopherson *sptep = 0ull; 40002aa07893SSean Christopherson return reserved; 40012aa07893SSean Christopherson } 40022aa07893SSean Christopherson 40039aa41879SSean Christopherson *sptep = sptes[leaf]; 40049aa41879SSean Christopherson 40059aa41879SSean Christopherson /* 40069aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 40079aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 40089aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 40099aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 40109aa41879SSean Christopherson */ 40119aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 40129aa41879SSean Christopherson leaf++; 401395fb5b02SBen Gardon 401495fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 401595fb5b02SBen Gardon 40169aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4017961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4018c50d8ae3SPaolo Bonzini 4019c50d8ae3SPaolo Bonzini if (reserved) { 4020bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4021c50d8ae3SPaolo Bonzini __func__, addr); 402295fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4023bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4024bb4cdf3aSSean Christopherson sptes[level], level, 4025961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4026c50d8ae3SPaolo Bonzini } 4027ddce6208SSean Christopherson 4028c50d8ae3SPaolo Bonzini return reserved; 4029c50d8ae3SPaolo Bonzini } 4030c50d8ae3SPaolo Bonzini 4031c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4032c50d8ae3SPaolo Bonzini { 4033c50d8ae3SPaolo Bonzini u64 spte; 4034c50d8ae3SPaolo Bonzini bool reserved; 4035c50d8ae3SPaolo Bonzini 4036c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4037c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4038c50d8ae3SPaolo Bonzini 403995fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 4040c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 4041c50d8ae3SPaolo Bonzini return -EINVAL; 4042c50d8ae3SPaolo Bonzini 4043c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4044c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 40450a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4046c50d8ae3SPaolo Bonzini 4047c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4048c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4049c50d8ae3SPaolo Bonzini 4050c50d8ae3SPaolo Bonzini if (direct) 4051c50d8ae3SPaolo Bonzini addr = 0; 4052c50d8ae3SPaolo Bonzini 4053c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4054c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4055c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4056c50d8ae3SPaolo Bonzini } 4057c50d8ae3SPaolo Bonzini 4058c50d8ae3SPaolo Bonzini /* 4059c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4060c50d8ae3SPaolo Bonzini * the address. 4061c50d8ae3SPaolo Bonzini */ 4062c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4063c50d8ae3SPaolo Bonzini } 4064c50d8ae3SPaolo Bonzini 4065c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4066b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4067c50d8ae3SPaolo Bonzini { 4068b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4069c50d8ae3SPaolo Bonzini return false; 4070c50d8ae3SPaolo Bonzini 4071b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4072c50d8ae3SPaolo Bonzini return false; 4073c50d8ae3SPaolo Bonzini 4074c50d8ae3SPaolo Bonzini /* 4075c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4076c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4077c50d8ae3SPaolo Bonzini */ 40789d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 4079c50d8ae3SPaolo Bonzini return true; 4080c50d8ae3SPaolo Bonzini 4081c50d8ae3SPaolo Bonzini return false; 4082c50d8ae3SPaolo Bonzini } 4083c50d8ae3SPaolo Bonzini 4084c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4085c50d8ae3SPaolo Bonzini { 4086c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4087c50d8ae3SPaolo Bonzini u64 spte; 4088c50d8ae3SPaolo Bonzini 4089c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 40903e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4091c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4092c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4093c50d8ae3SPaolo Bonzini } 4094c50d8ae3SPaolo Bonzini 40956f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 40966f3c1fc5SLiang Zhang { 40976f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 40986f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 40996f3c1fc5SLiang Zhang 41006f3c1fc5SLiang Zhang if (id << 12 == 0) 41016f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 41026f3c1fc5SLiang Zhang 41036f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 41046f3c1fc5SLiang Zhang } 41056f3c1fc5SLiang Zhang 4106e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 41079f1a8526SSean Christopherson gfn_t gfn) 4108c50d8ae3SPaolo Bonzini { 4109c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4110c50d8ae3SPaolo Bonzini 41116f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4112c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4113347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 4114d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 4115c50d8ae3SPaolo Bonzini 41169f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 41179f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4118c50d8ae3SPaolo Bonzini } 4119c50d8ae3SPaolo Bonzini 41208a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 41218a009d5bSSean Christopherson { 41228a009d5bSSean Christopherson int r; 41238a009d5bSSean Christopherson 41248a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 41258a009d5bSSean Christopherson work->wakeup_all) 41268a009d5bSSean Christopherson return; 41278a009d5bSSean Christopherson 41288a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 41298a009d5bSSean Christopherson if (unlikely(r)) 41308a009d5bSSean Christopherson return; 41318a009d5bSSean Christopherson 41328a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 41338a009d5bSSean Christopherson work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu)) 41348a009d5bSSean Christopherson return; 41358a009d5bSSean Christopherson 41368a009d5bSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true); 41378a009d5bSSean Christopherson } 41388a009d5bSSean Christopherson 41395276c616SSean Christopherson static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4140c50d8ae3SPaolo Bonzini { 4141e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4142c50d8ae3SPaolo Bonzini bool async; 4143c50d8ae3SPaolo Bonzini 4144e0c37868SSean Christopherson /* 4145e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4146e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4147e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4148e0c37868SSean Christopherson */ 4149e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 41505276c616SSean Christopherson return RET_PF_RETRY; 4151e0c37868SSean Christopherson 41529cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4153c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 41549cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4155e710c5f6SDavid Matlack fault->slot = NULL; 41563647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 41573647cd04SPaolo Bonzini fault->map_writable = false; 41585276c616SSean Christopherson return RET_PF_CONTINUE; 4159c50d8ae3SPaolo Bonzini } 41609cc13d60SMaxim Levitsky /* 41619cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 41629cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 41639cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 41649cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 41659cc13d60SMaxim Levitsky */ 41669cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 41675276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 41685276c616SSean Christopherson return RET_PF_EMULATE; 41699cc13d60SMaxim Levitsky } 4170c50d8ae3SPaolo Bonzini 4171c50d8ae3SPaolo Bonzini async = false; 41723647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, 41733647cd04SPaolo Bonzini fault->write, &fault->map_writable, 41743647cd04SPaolo Bonzini &fault->hva); 4175c50d8ae3SPaolo Bonzini if (!async) 41765276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4177c50d8ae3SPaolo Bonzini 41782839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 41793647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 41803647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 41811685c0f3SMingwei Zhang trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4182c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 41835276c616SSean Christopherson return RET_PF_RETRY; 41845276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 41855276c616SSean Christopherson return RET_PF_RETRY; 41865276c616SSean Christopherson } 4187c50d8ae3SPaolo Bonzini } 4188c50d8ae3SPaolo Bonzini 41893647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, 41903647cd04SPaolo Bonzini fault->write, &fault->map_writable, 41913647cd04SPaolo Bonzini &fault->hva); 41925276c616SSean Christopherson return RET_PF_CONTINUE; 4193c50d8ae3SPaolo Bonzini } 4194c50d8ae3SPaolo Bonzini 4195a955cad8SSean Christopherson /* 4196a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4197a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4198a955cad8SSean Christopherson */ 4199a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4200a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 4201a955cad8SSean Christopherson { 4202b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 420318c841e1SSean Christopherson 420418c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 420518c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 420618c841e1SSean Christopherson return true; 420718c841e1SSean Christopherson 420818c841e1SSean Christopherson /* 420918c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 421018c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 421118c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 421218c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 421318c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 421418c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 421518c841e1SSean Christopherson */ 4216527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4217a955cad8SSean Christopherson return true; 4218a955cad8SSean Christopherson 4219a955cad8SSean Christopherson return fault->slot && 422020ec3ebdSChao Peng mmu_invalidate_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4221a955cad8SSean Christopherson } 4222a955cad8SSean Christopherson 42234326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4224c50d8ae3SPaolo Bonzini { 422563c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4226c50d8ae3SPaolo Bonzini 42270f90e1c1SSean Christopherson unsigned long mmu_seq; 422883f06fa7SSean Christopherson int r; 4229c50d8ae3SPaolo Bonzini 42303c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4231e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4232e710c5f6SDavid Matlack 4233b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4234c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4235c50d8ae3SPaolo Bonzini 42363c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4237c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4238c4371c2aSSean Christopherson return r; 423983291445SSean Christopherson 4240378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4241c50d8ae3SPaolo Bonzini if (r) 4242c50d8ae3SPaolo Bonzini return r; 4243c50d8ae3SPaolo Bonzini 424420ec3ebdSChao Peng mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4245367fd790SSean Christopherson smp_rmb(); 4246367fd790SSean Christopherson 42475276c616SSean Christopherson r = kvm_faultin_pfn(vcpu, fault); 42485276c616SSean Christopherson if (r != RET_PF_CONTINUE) 42498f32d5e5SMaxim Levitsky return r; 4250367fd790SSean Christopherson 42515276c616SSean Christopherson r = handle_abnormal_pfn(vcpu, fault, ACC_ALL); 42525276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4253367fd790SSean Christopherson return r; 4254367fd790SSean Christopherson 4255367fd790SSean Christopherson r = RET_PF_RETRY; 4256a2855afcSBen Gardon 42570b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4258a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4259a2855afcSBen Gardon else 4260531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4261a2855afcSBen Gardon 4262a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4263367fd790SSean Christopherson goto out_unlock; 4264a955cad8SSean Christopherson 42657bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 42667bd7ded6SSean Christopherson if (r) 4267367fd790SSean Christopherson goto out_unlock; 4268bb18842eSBen Gardon 42690b873fd7SDavid Matlack if (is_tdp_mmu_fault) 42702f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4271bb18842eSBen Gardon else 427243b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 42730f90e1c1SSean Christopherson 4274367fd790SSean Christopherson out_unlock: 42750b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4276a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4277a2855afcSBen Gardon else 4278531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 42793647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4280367fd790SSean Christopherson return r; 4281c50d8ae3SPaolo Bonzini } 4282c50d8ae3SPaolo Bonzini 4283c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4284c501040aSPaolo Bonzini struct kvm_page_fault *fault) 42850f90e1c1SSean Christopherson { 42864326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 42870f90e1c1SSean Christopherson 42880f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 42894326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 42904326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 42910f90e1c1SSean Christopherson } 42920f90e1c1SSean Christopherson 4293c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4294c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4295c50d8ae3SPaolo Bonzini { 4296c50d8ae3SPaolo Bonzini int r = 1; 42979ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4298c50d8ae3SPaolo Bonzini 4299736c291cSSean Christopherson #ifndef CONFIG_X86_64 4300736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4301736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4302736c291cSSean Christopherson return -EFAULT; 4303736c291cSSean Christopherson #endif 4304736c291cSSean Christopherson 4305c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 43069ce372b3SVitaly Kuznetsov if (!flags) { 4307faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4308c50d8ae3SPaolo Bonzini 4309c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4310c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4311c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4312c50d8ae3SPaolo Bonzini insn_len); 43139ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 431468fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4315c50d8ae3SPaolo Bonzini local_irq_disable(); 43166bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4317c50d8ae3SPaolo Bonzini local_irq_enable(); 43189ce372b3SVitaly Kuznetsov } else { 43199ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4320c50d8ae3SPaolo Bonzini } 43219ce372b3SVitaly Kuznetsov 4322c50d8ae3SPaolo Bonzini return r; 4323c50d8ae3SPaolo Bonzini } 4324c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4325c50d8ae3SPaolo Bonzini 4326c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4327c50d8ae3SPaolo Bonzini { 4328d5e90a69SSean Christopherson /* 4329d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4330d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 4331d5e90a69SSean Christopherson * across the entire mapping. If the host MTRRs are ignored by TDP 4332d5e90a69SSean Christopherson * (shadow_memtype_mask is non-zero), and the VM has non-coherent DMA 4333d5e90a69SSean Christopherson * (DMA doesn't snoop CPU caches), KVM's ABI is to honor the memtype 4334d5e90a69SSean Christopherson * from the guest's MTRRs so that guest accesses to memory that is 4335d5e90a69SSean Christopherson * DMA'd aren't cached against the guest's wishes. 4336d5e90a69SSean Christopherson * 4337d5e90a69SSean Christopherson * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 4338d5e90a69SSean Christopherson * e.g. KVM will force UC memtype for host MMIO. 4339d5e90a69SSean Christopherson */ 4340d5e90a69SSean Christopherson if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) { 4341d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 43424326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 43434326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4344c50d8ae3SPaolo Bonzini 4345cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4346cb9b88c6SSean Christopherson break; 4347d5e90a69SSean Christopherson } 4348c50d8ae3SPaolo Bonzini } 4349c50d8ae3SPaolo Bonzini 43504326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4351c50d8ae3SPaolo Bonzini } 4352c50d8ae3SPaolo Bonzini 435384a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4354c50d8ae3SPaolo Bonzini { 4355c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4356c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4357c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 43585efac074SPaolo Bonzini context->invlpg = NULL; 4359c50d8ae3SPaolo Bonzini } 4360c50d8ae3SPaolo Bonzini 4361be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 43620be44352SSean Christopherson union kvm_mmu_page_role role) 43630be44352SSean Christopherson { 4364be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 43655499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4366e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 43670be44352SSean Christopherson } 43680be44352SSean Christopherson 4369c50d8ae3SPaolo Bonzini /* 43705499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 43715499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 43725499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 43735499ea73SPaolo Bonzini * true is returned. 43745499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 43755499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4376c50d8ae3SPaolo Bonzini */ 43775499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 43785499ea73SPaolo Bonzini gpa_t new_pgd, 4379c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4380c50d8ae3SPaolo Bonzini { 4381c50d8ae3SPaolo Bonzini uint i; 4382c50d8ae3SPaolo Bonzini 4383b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 43840be44352SSean Christopherson return true; 43850be44352SSean Christopherson 4386c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 43875499ea73SPaolo Bonzini /* 43885499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 43895499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 43905499ea73SPaolo Bonzini * 0 C 1 2 3 43915499ea73SPaolo Bonzini * 1 C 0 2 3 43925499ea73SPaolo Bonzini * 2 C 0 1 3 43935499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 43945499ea73SPaolo Bonzini */ 4395b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4396b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 43975499ea73SPaolo Bonzini return true; 4398c50d8ae3SPaolo Bonzini } 4399c50d8ae3SPaolo Bonzini 44005499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 44015499ea73SPaolo Bonzini return false; 4402c50d8ae3SPaolo Bonzini } 4403c50d8ae3SPaolo Bonzini 4404c50d8ae3SPaolo Bonzini /* 44055499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 44065499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 44075499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 44085499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 44095499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 44105499ea73SPaolo Bonzini */ 44115499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 44125499ea73SPaolo Bonzini gpa_t new_pgd, 44135499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 44145499ea73SPaolo Bonzini { 44155499ea73SPaolo Bonzini uint i; 44165499ea73SPaolo Bonzini 44175499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 44185499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 44195499ea73SPaolo Bonzini goto hit; 44205499ea73SPaolo Bonzini 44215499ea73SPaolo Bonzini return false; 44225499ea73SPaolo Bonzini 44235499ea73SPaolo Bonzini hit: 44245499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 44255499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 44265499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 44275499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 44285499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 44295499ea73SPaolo Bonzini return true; 44305499ea73SPaolo Bonzini } 44315499ea73SPaolo Bonzini 44325499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 44335499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 44345499ea73SPaolo Bonzini { 44355499ea73SPaolo Bonzini /* 44365499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4437c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4438c50d8ae3SPaolo Bonzini * later if necessary. 4439c50d8ae3SPaolo Bonzini */ 44405499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 44415499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4442c50d8ae3SPaolo Bonzini 44435499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 44445499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 44455499ea73SPaolo Bonzini else 44465499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4447c50d8ae3SPaolo Bonzini } 4448c50d8ae3SPaolo Bonzini 4449d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4450c50d8ae3SPaolo Bonzini { 44510c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 44527a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 44530c1c92f1SPaolo Bonzini 44545499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 44555499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4456b869855bSSean Christopherson return; 4457c50d8ae3SPaolo Bonzini } 4458c50d8ae3SPaolo Bonzini 4459c50d8ae3SPaolo Bonzini /* 4460b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4461b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4462527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4463527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4464b869855bSSean Christopherson */ 4465b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4466b869855bSSean Christopherson 4467b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4468b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4469b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4470b5129100SSean Christopherson } 4471b869855bSSean Christopherson 4472b869855bSSean Christopherson /* 4473b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4474b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4475b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4476b869855bSSean Christopherson * the shadow page tables. 4477c50d8ae3SPaolo Bonzini */ 4478c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4479c50d8ae3SPaolo Bonzini 4480daa5b6c1SBen Gardon /* 4481daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4482daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4483daa5b6c1SBen Gardon */ 4484daa5b6c1SBen Gardon if (!new_role.direct) 4485daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4486b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4487c50d8ae3SPaolo Bonzini } 4488be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4489c50d8ae3SPaolo Bonzini 4490c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4491c50d8ae3SPaolo Bonzini { 4492c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4493c50d8ae3SPaolo Bonzini } 4494c50d8ae3SPaolo Bonzini 4495c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4496c3e5e415SLai Jiangshan unsigned int access) 4497c50d8ae3SPaolo Bonzini { 4498c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4499c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4500c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4501c50d8ae3SPaolo Bonzini return true; 4502c50d8ae3SPaolo Bonzini } 4503c50d8ae3SPaolo Bonzini 4504c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4505c50d8ae3SPaolo Bonzini return true; 4506c50d8ae3SPaolo Bonzini } 4507c50d8ae3SPaolo Bonzini 4508c50d8ae3SPaolo Bonzini return false; 4509c50d8ae3SPaolo Bonzini } 4510c50d8ae3SPaolo Bonzini 4511c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4512c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4513c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4514c50d8ae3SPaolo Bonzini #undef PTTYPE 4515c50d8ae3SPaolo Bonzini 4516c50d8ae3SPaolo Bonzini #define PTTYPE 64 4517c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4518c50d8ae3SPaolo Bonzini #undef PTTYPE 4519c50d8ae3SPaolo Bonzini 4520c50d8ae3SPaolo Bonzini #define PTTYPE 32 4521c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4522c50d8ae3SPaolo Bonzini #undef PTTYPE 4523c50d8ae3SPaolo Bonzini 4524c50d8ae3SPaolo Bonzini static void 4525b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 45265b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4527c50d8ae3SPaolo Bonzini bool pse, bool amd) 4528c50d8ae3SPaolo Bonzini { 4529c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4530c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 45315b7f575cSSean Christopherson u64 high_bits_rsvd; 4532c50d8ae3SPaolo Bonzini 4533c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4534c50d8ae3SPaolo Bonzini 4535c50d8ae3SPaolo Bonzini if (!gbpages) 4536c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4537c50d8ae3SPaolo Bonzini 45385b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 45395b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 45405b7f575cSSean Christopherson else 45415b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 45425b7f575cSSean Christopherson 45435b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 45445b7f575cSSean Christopherson if (!nx) 45455b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 45465b7f575cSSean Christopherson 4547c50d8ae3SPaolo Bonzini /* 4548c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4549c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4550c50d8ae3SPaolo Bonzini */ 4551c50d8ae3SPaolo Bonzini if (amd) 4552c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4553c50d8ae3SPaolo Bonzini 4554c50d8ae3SPaolo Bonzini switch (level) { 4555c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4556c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4557c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4558c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4559c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4560c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4561c50d8ae3SPaolo Bonzini 4562c50d8ae3SPaolo Bonzini if (!pse) { 4563c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4564c50d8ae3SPaolo Bonzini break; 4565c50d8ae3SPaolo Bonzini } 4566c50d8ae3SPaolo Bonzini 4567c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4568c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4569c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4570c50d8ae3SPaolo Bonzini else 4571c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4572c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4573c50d8ae3SPaolo Bonzini break; 4574c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 45755b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 45765b7f575cSSean Christopherson high_bits_rsvd | 45775b7f575cSSean Christopherson rsvd_bits(5, 8) | 45785b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 45795b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 45805b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 45815b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4582c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4583c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4584c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4585c50d8ae3SPaolo Bonzini break; 4586c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 45875b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 45885b7f575cSSean Christopherson nonleaf_bit8_rsvd | 45895b7f575cSSean Christopherson rsvd_bits(7, 7); 4590c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4591c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4592df561f66SGustavo A. R. Silva fallthrough; 4593c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 45945b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 45955b7f575cSSean Christopherson nonleaf_bit8_rsvd | 45965b7f575cSSean Christopherson rsvd_bits(7, 7); 45975b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 45985b7f575cSSean Christopherson gbpages_bit_rsvd; 45995b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 46005b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4601c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4602c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 46035b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 46045b7f575cSSean Christopherson gbpages_bit_rsvd | 4605c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 46065b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4607c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4608c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4609c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4610c50d8ae3SPaolo Bonzini break; 4611c50d8ae3SPaolo Bonzini } 4612c50d8ae3SPaolo Bonzini } 4613c50d8ae3SPaolo Bonzini 461427de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 461527de9250SSean Christopherson { 461627de9250SSean Christopherson /* 461727de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 461827de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 461927de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 462027de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 462127de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 462227de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 462327de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 462427de9250SSean Christopherson */ 462527de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 462627de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 462727de9250SSean Christopherson } 462827de9250SSean Christopherson 4629c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4630c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4631c50d8ae3SPaolo Bonzini { 4632b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 46335b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 46344d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 463527de9250SSean Christopherson guest_can_use_gbpages(vcpu), 46364e9c0d80SSean Christopherson is_cr4_pse(context), 463723493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4638c50d8ae3SPaolo Bonzini } 4639c50d8ae3SPaolo Bonzini 4640c50d8ae3SPaolo Bonzini static void 4641c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 464284ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4643c50d8ae3SPaolo Bonzini { 46445b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 464584ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4646c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4647c50d8ae3SPaolo Bonzini 464884ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 464984ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 465084ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 465184ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 465284ea5c09SLai Jiangshan 46535b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 46545b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 465584ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 465684ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 46575b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4658c50d8ae3SPaolo Bonzini 4659c50d8ae3SPaolo Bonzini /* large page */ 4660c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4661c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 466284ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 466384ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4664c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4665c50d8ae3SPaolo Bonzini 4666c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4667c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4668c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4669c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4670c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4671c50d8ae3SPaolo Bonzini if (!execonly) { 4672c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4673c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4674c50d8ae3SPaolo Bonzini } 4675c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4676c50d8ae3SPaolo Bonzini } 4677c50d8ae3SPaolo Bonzini 4678c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 467984ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4680c50d8ae3SPaolo Bonzini { 4681c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 468284ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 468384ea5c09SLai Jiangshan huge_page_level); 4684c50d8ae3SPaolo Bonzini } 4685c50d8ae3SPaolo Bonzini 46866f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 46876f8e65a6SSean Christopherson { 46886f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 46896f8e65a6SSean Christopherson } 46906f8e65a6SSean Christopherson 4691c50d8ae3SPaolo Bonzini /* 4692c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4693c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4694c50d8ae3SPaolo Bonzini * follow the features in guest. 4695c50d8ae3SPaolo Bonzini */ 469616be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 469716be1d12SSean Christopherson struct kvm_mmu *context) 4698c50d8ae3SPaolo Bonzini { 46998c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 47008c985b2dSSean Christopherson bool is_amd = true; 47018c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 47028c985b2dSSean Christopherson bool is_pse = false; 4703c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4704c50d8ae3SPaolo Bonzini int i; 4705c50d8ae3SPaolo Bonzini 4706a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 47078c985b2dSSean Christopherson 4708c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4709b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4710a972e29cSPaolo Bonzini context->root_role.level, 47117a458f0eSPaolo Bonzini context->root_role.efer_nx, 471227de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4713c50d8ae3SPaolo Bonzini 4714c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4715c50d8ae3SPaolo Bonzini return; 4716c50d8ae3SPaolo Bonzini 4717a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4718e54f1ff2SKai Huang /* 4719e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4720e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4721e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4722e54f1ff2SKai Huang * not allowed to be set. 4723e54f1ff2SKai Huang */ 4724e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4725e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4726e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4727e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4728c50d8ae3SPaolo Bonzini } 4729c50d8ae3SPaolo Bonzini 4730c50d8ae3SPaolo Bonzini } 4731c50d8ae3SPaolo Bonzini 4732c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4733c50d8ae3SPaolo Bonzini { 4734c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4735c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4736c50d8ae3SPaolo Bonzini } 4737c50d8ae3SPaolo Bonzini 4738c50d8ae3SPaolo Bonzini /* 4739c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4740c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4741c50d8ae3SPaolo Bonzini */ 4742c50d8ae3SPaolo Bonzini static void 4743e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4744c50d8ae3SPaolo Bonzini { 4745c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4746c50d8ae3SPaolo Bonzini int i; 4747c50d8ae3SPaolo Bonzini 4748c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4749c50d8ae3SPaolo Bonzini 4750c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4751b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 47526c6ab524SSean Christopherson context->root_role.level, true, 4753c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 47548c985b2dSSean Christopherson false, true); 4755c50d8ae3SPaolo Bonzini else 4756c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 475784ea5c09SLai Jiangshan reserved_hpa_bits(), false, 475884ea5c09SLai Jiangshan max_huge_page_level); 4759c50d8ae3SPaolo Bonzini 4760c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4761c50d8ae3SPaolo Bonzini return; 4762c50d8ae3SPaolo Bonzini 4763a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4764c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4765c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4766c50d8ae3SPaolo Bonzini } 4767c50d8ae3SPaolo Bonzini } 4768c50d8ae3SPaolo Bonzini 4769c50d8ae3SPaolo Bonzini /* 4770c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4771c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4772c50d8ae3SPaolo Bonzini */ 4773c50d8ae3SPaolo Bonzini static void 4774e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4775c50d8ae3SPaolo Bonzini { 4776c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 477784ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 477884ea5c09SLai Jiangshan max_huge_page_level); 4779c50d8ae3SPaolo Bonzini } 4780c50d8ae3SPaolo Bonzini 4781c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4782c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4783c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4784c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4785c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4786c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4787c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4788c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4789c50d8ae3SPaolo Bonzini 4790c50d8ae3SPaolo Bonzini 4791c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4792c50d8ae3SPaolo Bonzini { 4793c50d8ae3SPaolo Bonzini unsigned byte; 4794c50d8ae3SPaolo Bonzini 4795c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4796c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4797c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4798c50d8ae3SPaolo Bonzini 4799c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4800c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4801c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 480290599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4803c50d8ae3SPaolo Bonzini 4804c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4805c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4806c50d8ae3SPaolo Bonzini 4807c50d8ae3SPaolo Bonzini /* 4808c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4809c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4810c50d8ae3SPaolo Bonzini */ 4811c50d8ae3SPaolo Bonzini 4812c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4813c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4814c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4815c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4816c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4817c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4818c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4819c50d8ae3SPaolo Bonzini u8 smepf = 0; 4820c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4821c50d8ae3SPaolo Bonzini u8 smapf = 0; 4822c50d8ae3SPaolo Bonzini 4823c50d8ae3SPaolo Bonzini if (!ept) { 4824c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4825c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4826c50d8ae3SPaolo Bonzini 4827c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 482890599c28SSean Christopherson if (!efer_nx) 4829c50d8ae3SPaolo Bonzini ff = 0; 4830c50d8ae3SPaolo Bonzini 4831c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4832c50d8ae3SPaolo Bonzini if (!cr0_wp) 4833c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4834c50d8ae3SPaolo Bonzini 4835c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4836c50d8ae3SPaolo Bonzini if (cr4_smep) 4837c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4838c50d8ae3SPaolo Bonzini 4839c50d8ae3SPaolo Bonzini /* 4840c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4841c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4842c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4843c50d8ae3SPaolo Bonzini * conditions are true: 4844c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4845c50d8ae3SPaolo Bonzini * - A user page is accessed 4846c50d8ae3SPaolo Bonzini * - The access is not a fetch 48474f4aa80eSLai Jiangshan * - The access is supervisor mode 48484f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4849c50d8ae3SPaolo Bonzini * 485094b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 485194b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4852c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4853c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4854c50d8ae3SPaolo Bonzini */ 4855c50d8ae3SPaolo Bonzini if (cr4_smap) 4856c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4857c50d8ae3SPaolo Bonzini } 4858c50d8ae3SPaolo Bonzini 4859c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4860c50d8ae3SPaolo Bonzini } 4861c50d8ae3SPaolo Bonzini } 4862c50d8ae3SPaolo Bonzini 4863c50d8ae3SPaolo Bonzini /* 4864c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4865c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4866c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4867c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4868c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4869c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4870c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4871c50d8ae3SPaolo Bonzini * 4872c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4873c50d8ae3SPaolo Bonzini * page tables and the machine state: 4874c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4875c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4876c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4877c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4878c50d8ae3SPaolo Bonzini * 4879c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4880c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4881c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4882c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4883c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4884c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4885c50d8ae3SPaolo Bonzini * only will be masked away. 4886c50d8ae3SPaolo Bonzini */ 48872e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4888c50d8ae3SPaolo Bonzini { 4889c50d8ae3SPaolo Bonzini unsigned bit; 4890c50d8ae3SPaolo Bonzini bool wp; 4891c50d8ae3SPaolo Bonzini 4892c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4893a3ca5281SChenyi Qiang 4894a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4895c50d8ae3SPaolo Bonzini return; 4896c50d8ae3SPaolo Bonzini 48972e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4898c50d8ae3SPaolo Bonzini 4899c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4900c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4901c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4902c50d8ae3SPaolo Bonzini 4903c50d8ae3SPaolo Bonzini pfec = bit << 1; 4904c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4905c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4906c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4907c50d8ae3SPaolo Bonzini 4908c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4909c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4910c50d8ae3SPaolo Bonzini 4911c50d8ae3SPaolo Bonzini /* 4912c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4913c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4914c50d8ae3SPaolo Bonzini */ 4915c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4916c50d8ae3SPaolo Bonzini /* 4917c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4918c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4919c50d8ae3SPaolo Bonzini */ 4920c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4921c50d8ae3SPaolo Bonzini 4922c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4923c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4924c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4925c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4926c50d8ae3SPaolo Bonzini 4927c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4928c50d8ae3SPaolo Bonzini } 4929c50d8ae3SPaolo Bonzini } 4930c50d8ae3SPaolo Bonzini 4931533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4932533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4933c50d8ae3SPaolo Bonzini { 4934533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4935533f9a4bSSean Christopherson return; 4936c50d8ae3SPaolo Bonzini 4937c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 4938533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4939533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4940c50d8ae3SPaolo Bonzini } 4941c50d8ae3SPaolo Bonzini 4942fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4943c50d8ae3SPaolo Bonzini { 4944c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4945c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4946c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4947c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4948c50d8ae3SPaolo Bonzini } 4949c50d8ae3SPaolo Bonzini 495084a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4951c50d8ae3SPaolo Bonzini { 4952c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4953c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4954c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4955c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4956c50d8ae3SPaolo Bonzini } 4957c50d8ae3SPaolo Bonzini 49587a7ae829SPaolo Bonzini static union kvm_cpu_role 4959e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 4960e5ed0fb0SPaolo Bonzini { 49617a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4962e5ed0fb0SPaolo Bonzini 4963e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 4964e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 4965e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4966e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 4967e5ed0fb0SPaolo Bonzini 4968e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 4969e5ed0fb0SPaolo Bonzini role.base.direct = 1; 4970e5ed0fb0SPaolo Bonzini return role; 4971e5ed0fb0SPaolo Bonzini } 4972e5ed0fb0SPaolo Bonzini 4973e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 4974e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 4975e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 4976e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 4977e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 497860f3cb60SPaolo Bonzini 497960f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 498060f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 498160f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 498260f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 498360f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 498460f3cb60SPaolo Bonzini else 498560f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 4986e5ed0fb0SPaolo Bonzini 4987e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 4988e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 4989e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 4990e5ed0fb0SPaolo Bonzini 4991e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 4992e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 4993e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 4994e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 4995e5ed0fb0SPaolo Bonzini return role; 4996e5ed0fb0SPaolo Bonzini } 4997e5ed0fb0SPaolo Bonzini 4998d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 4999d468d94bSSean Christopherson { 5000746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5001746700d2SWei Huang if (tdp_root_level) 5002746700d2SWei Huang return tdp_root_level; 5003746700d2SWei Huang 5004d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 500583013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5006d468d94bSSean Christopherson return 4; 5007d468d94bSSean Christopherson 500883013059SSean Christopherson return max_tdp_level; 5009d468d94bSSean Christopherson } 5010d468d94bSSean Christopherson 50117a458f0eSPaolo Bonzini static union kvm_mmu_page_role 50128626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 50137a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5014c50d8ae3SPaolo Bonzini { 50157a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5016c50d8ae3SPaolo Bonzini 50177a458f0eSPaolo Bonzini role.access = ACC_ALL; 50187a458f0eSPaolo Bonzini role.cr0_wp = true; 50197a458f0eSPaolo Bonzini role.efer_nx = true; 50207a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 50217a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 502254275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 50237a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 50247a458f0eSPaolo Bonzini role.direct = true; 50257a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5026c50d8ae3SPaolo Bonzini 5027c50d8ae3SPaolo Bonzini return role; 5028c50d8ae3SPaolo Bonzini } 5029c50d8ae3SPaolo Bonzini 503039e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5031a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5032c50d8ae3SPaolo Bonzini { 50338c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 50347a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5035c50d8ae3SPaolo Bonzini 5036e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 50377a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5038c50d8ae3SPaolo Bonzini return; 5039c50d8ae3SPaolo Bonzini 5040e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 50417a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 50427a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5043c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 50445efac074SPaolo Bonzini context->invlpg = NULL; 5045d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5046c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5047c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5048c50d8ae3SPaolo Bonzini 504936f26787SSean Christopherson if (!is_cr0_pg(context)) 5050c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 505136f26787SSean Christopherson else if (is_cr4_pae(context)) 5052c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5053f4bd6f73SSean Christopherson else 5054c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5055c50d8ae3SPaolo Bonzini 5056533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5057e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5058c50d8ae3SPaolo Bonzini } 5059c50d8ae3SPaolo Bonzini 50608c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 50617a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 50627a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5063c50d8ae3SPaolo Bonzini { 5064e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 50657a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 506618db1b17SSean Christopherson return; 5067c50d8ae3SPaolo Bonzini 5068e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 50697a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 507018db1b17SSean Christopherson 507136f26787SSean Christopherson if (!is_cr0_pg(context)) 507284a16226SSean Christopherson nonpaging_init_context(context); 507336f26787SSean Christopherson else if (is_cr4_pae(context)) 5074fe660f72SSean Christopherson paging64_init_context(context); 5075c50d8ae3SPaolo Bonzini else 507684a16226SSean Christopherson paging32_init_context(context); 5077c50d8ae3SPaolo Bonzini 5078533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5079c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5080c50d8ae3SPaolo Bonzini } 50810f04a2acSVitaly Kuznetsov 5082594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5083a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 50840f04a2acSVitaly Kuznetsov { 50858c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 508656b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 508756b321f9SPaolo Bonzini 508856b321f9SPaolo Bonzini root_role = cpu_role.base; 508956b321f9SPaolo Bonzini 509056b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 509156b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 509256b321f9SPaolo Bonzini 509356b321f9SPaolo Bonzini /* 509456b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 509556b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 509656b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 509756b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 509856b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 509956b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 510056b321f9SPaolo Bonzini * MMU contexts. 510156b321f9SPaolo Bonzini */ 510256b321f9SPaolo Bonzini root_role.efer_nx = true; 51030f04a2acSVitaly Kuznetsov 51047a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 51050f04a2acSVitaly Kuznetsov } 51060f04a2acSVitaly Kuznetsov 5107dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5108dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 51090f04a2acSVitaly Kuznetsov { 51108c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5111594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5112594e91a1SSean Christopherson .cr0 = cr0, 511328f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5114594e91a1SSean Christopherson .efer = efer, 5115594e91a1SSean Christopherson }; 51167a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 511756b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 511856b321f9SPaolo Bonzini 511956b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 512056b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 512156b321f9SPaolo Bonzini 512256b321f9SPaolo Bonzini root_role = cpu_role.base; 512356b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 512484e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 512584e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 512684e5ffd0SLai Jiangshan root_role.passthrough = 1; 51270f04a2acSVitaly Kuznetsov 51287a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5129d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 51300f04a2acSVitaly Kuznetsov } 51310f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5132c50d8ae3SPaolo Bonzini 51337a7ae829SPaolo Bonzini static union kvm_cpu_role 5134c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5135bb1fcc70SSean Christopherson bool execonly, u8 level) 5136c50d8ae3SPaolo Bonzini { 51377a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5138c50d8ae3SPaolo Bonzini 5139daed87b8SPaolo Bonzini /* 5140daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5141daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5142daed87b8SPaolo Bonzini */ 5143daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5144bb1fcc70SSean Christopherson role.base.level = level; 5145bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5146c50d8ae3SPaolo Bonzini role.base.direct = false; 5147c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5148c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5149c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5150c50d8ae3SPaolo Bonzini 5151cd6767c3SSean Christopherson role.ext.word = 0; 5152c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5153cd6767c3SSean Christopherson role.ext.valid = 1; 5154c50d8ae3SPaolo Bonzini 5155c50d8ae3SPaolo Bonzini return role; 5156c50d8ae3SPaolo Bonzini } 5157c50d8ae3SPaolo Bonzini 5158c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5159cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5160cc022ae1SLai Jiangshan gpa_t new_eptp) 5161c50d8ae3SPaolo Bonzini { 51628c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5163bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 51647a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5165c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5166bb1fcc70SSean Christopherson execonly, level); 5167c50d8ae3SPaolo Bonzini 5168e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5169e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5170e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 51717a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 517218db1b17SSean Christopherson 5173c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5174c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5175c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 5176c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 5177347a0d0dSPaolo Bonzini 5178c596f147SSean Christopherson update_permission_bitmask(context, true); 517928f091bcSPaolo Bonzini context->pkru_mask = 0; 5180cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5181e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5182c50d8ae3SPaolo Bonzini } 51833cffc89dSPaolo Bonzini 5184d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 51853cffc89dSPaolo Bonzini } 5186c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5187c50d8ae3SPaolo Bonzini 518839e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5189a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5190c50d8ae3SPaolo Bonzini { 51918c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5192c50d8ae3SPaolo Bonzini 5193a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5194929d1cfaSPaolo Bonzini 5195d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5196c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5197c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5198c50d8ae3SPaolo Bonzini } 5199c50d8ae3SPaolo Bonzini 520039e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5201a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5202c50d8ae3SPaolo Bonzini { 5203c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5204c50d8ae3SPaolo Bonzini 5205e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5206c50d8ae3SPaolo Bonzini return; 5207c50d8ae3SPaolo Bonzini 5208e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5209d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5210c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5211c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5212c50d8ae3SPaolo Bonzini 5213c50d8ae3SPaolo Bonzini /* 52145efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 52155efac074SPaolo Bonzini * SPTEs. 52165efac074SPaolo Bonzini */ 52175efac074SPaolo Bonzini g_context->invlpg = NULL; 52185efac074SPaolo Bonzini 52195efac074SPaolo Bonzini /* 5220c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5221c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5222c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5223c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5224c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5225c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5226c50d8ae3SPaolo Bonzini */ 5227fa4b5588SSean Christopherson if (!is_paging(vcpu)) 52281f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5229fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 52301f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5231fa4b5588SSean Christopherson else if (is_pae(vcpu)) 52321f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5233fa4b5588SSean Christopherson else 52341f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5235fa4b5588SSean Christopherson 5236533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5237c50d8ae3SPaolo Bonzini } 5238c50d8ae3SPaolo Bonzini 5239c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5240c50d8ae3SPaolo Bonzini { 524139e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5242a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 524339e7e2bfSPaolo Bonzini 5244c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5245a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5246c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5247a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5248c50d8ae3SPaolo Bonzini else 5249a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5250c50d8ae3SPaolo Bonzini } 5251c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5252c50d8ae3SPaolo Bonzini 525349c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 525449c6f875SSean Christopherson { 525549c6f875SSean Christopherson /* 525649c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 525749c6f875SSean Christopherson * information is factored into reserved bit calculations. 5258feb627e8SVitaly Kuznetsov * 5259feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5260feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5261feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5262feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5263feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5264feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5265feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 526649c6f875SSean Christopherson */ 52677a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 52687a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 52697a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5270e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5271e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5272e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 527349c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 527463f5a190SSean Christopherson 527563f5a190SSean Christopherson /* 5276feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5277feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 527863f5a190SSean Christopherson */ 5279feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 528049c6f875SSean Christopherson } 528149c6f875SSean Christopherson 5282c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5283c50d8ae3SPaolo Bonzini { 5284c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5285c9060662SSean Christopherson kvm_init_mmu(vcpu); 5286c50d8ae3SPaolo Bonzini } 5287c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5288c50d8ae3SPaolo Bonzini 5289c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5290c50d8ae3SPaolo Bonzini { 5291c50d8ae3SPaolo Bonzini int r; 5292c50d8ae3SPaolo Bonzini 5293347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5294c50d8ae3SPaolo Bonzini if (r) 5295c50d8ae3SPaolo Bonzini goto out; 5296748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5297c50d8ae3SPaolo Bonzini if (r) 5298c50d8ae3SPaolo Bonzini goto out; 5299347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 53006e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 53016e6ec584SSean Christopherson else 53026e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5303c50d8ae3SPaolo Bonzini if (r) 5304c50d8ae3SPaolo Bonzini goto out; 5305a91f387bSSean Christopherson 5306a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5307a91f387bSSean Christopherson 5308727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5309db01416bSSean Christopherson 5310db01416bSSean Christopherson /* 5311db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5312db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5313db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5314db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5315db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5316db01416bSSean Christopherson */ 5317e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5318c50d8ae3SPaolo Bonzini out: 5319c50d8ae3SPaolo Bonzini return r; 5320c50d8ae3SPaolo Bonzini } 5321c50d8ae3SPaolo Bonzini 5322c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5323c50d8ae3SPaolo Bonzini { 53240c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 53250c1c92f1SPaolo Bonzini 53260c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5327b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 53280c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5329b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 53306d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5331c50d8ae3SPaolo Bonzini } 5332c50d8ae3SPaolo Bonzini 5333527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5334527d5cd7SSean Christopherson { 5335527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5336527d5cd7SSean Christopherson 5337527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5338527d5cd7SSean Christopherson return false; 5339527d5cd7SSean Christopherson 5340527d5cd7SSean Christopherson /* 5341527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5342527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5343527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5344527d5cd7SSean Christopherson * such false positives are relatively rare: 5345527d5cd7SSean Christopherson * 5346527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5347527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5348527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5349527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5350527d5cd7SSean Christopherson */ 5351527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5352527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5353527d5cd7SSean Christopherson } 5354527d5cd7SSean Christopherson 5355527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5356527d5cd7SSean Christopherson { 5357527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5358527d5cd7SSean Christopherson int i; 5359527d5cd7SSean Christopherson 5360527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5361527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5362527d5cd7SSean Christopherson 5363527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5364cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5365527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5366527d5cd7SSean Christopherson } 5367527d5cd7SSean Christopherson 5368527d5cd7SSean Christopherson if (roots_to_free) 5369527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5370527d5cd7SSean Christopherson } 5371527d5cd7SSean Christopherson 5372527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5373527d5cd7SSean Christopherson { 5374527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5375527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5376527d5cd7SSean Christopherson } 5377527d5cd7SSean Christopherson 5378c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5379c50d8ae3SPaolo Bonzini int *bytes) 5380c50d8ae3SPaolo Bonzini { 5381c50d8ae3SPaolo Bonzini u64 gentry = 0; 5382c50d8ae3SPaolo Bonzini int r; 5383c50d8ae3SPaolo Bonzini 5384c50d8ae3SPaolo Bonzini /* 5385c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5386c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5387c50d8ae3SPaolo Bonzini * when they have the same mode. 5388c50d8ae3SPaolo Bonzini */ 5389c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5390c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5391c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5392c50d8ae3SPaolo Bonzini *bytes = 8; 5393c50d8ae3SPaolo Bonzini } 5394c50d8ae3SPaolo Bonzini 5395c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5396c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5397c50d8ae3SPaolo Bonzini if (r) 5398c50d8ae3SPaolo Bonzini gentry = 0; 5399c50d8ae3SPaolo Bonzini } 5400c50d8ae3SPaolo Bonzini 5401c50d8ae3SPaolo Bonzini return gentry; 5402c50d8ae3SPaolo Bonzini } 5403c50d8ae3SPaolo Bonzini 5404c50d8ae3SPaolo Bonzini /* 5405c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5406c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5407c50d8ae3SPaolo Bonzini */ 5408c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5409c50d8ae3SPaolo Bonzini { 5410c50d8ae3SPaolo Bonzini /* 5411c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5412c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5413c50d8ae3SPaolo Bonzini */ 54143bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5415c50d8ae3SPaolo Bonzini return false; 5416c50d8ae3SPaolo Bonzini 5417c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5418c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5419c50d8ae3SPaolo Bonzini } 5420c50d8ae3SPaolo Bonzini 5421c50d8ae3SPaolo Bonzini /* 5422c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5423c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5424c50d8ae3SPaolo Bonzini */ 5425c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5426c50d8ae3SPaolo Bonzini int bytes) 5427c50d8ae3SPaolo Bonzini { 5428c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5429c50d8ae3SPaolo Bonzini 5430c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5431c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5432c50d8ae3SPaolo Bonzini 5433c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5434bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5435c50d8ae3SPaolo Bonzini 5436c50d8ae3SPaolo Bonzini /* 5437c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5438c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5439c50d8ae3SPaolo Bonzini */ 5440c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5441c50d8ae3SPaolo Bonzini return false; 5442c50d8ae3SPaolo Bonzini 5443c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5444c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5445c50d8ae3SPaolo Bonzini 5446c50d8ae3SPaolo Bonzini return misaligned; 5447c50d8ae3SPaolo Bonzini } 5448c50d8ae3SPaolo Bonzini 5449c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5450c50d8ae3SPaolo Bonzini { 5451c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5452c50d8ae3SPaolo Bonzini u64 *spte; 5453c50d8ae3SPaolo Bonzini int level; 5454c50d8ae3SPaolo Bonzini 5455c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5456c50d8ae3SPaolo Bonzini level = sp->role.level; 5457c50d8ae3SPaolo Bonzini *nspte = 1; 5458bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5459c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5460c50d8ae3SPaolo Bonzini /* 5461c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5462c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5463c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5464c50d8ae3SPaolo Bonzini */ 5465c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5466c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5467c50d8ae3SPaolo Bonzini page_offset <<= 1; 5468c50d8ae3SPaolo Bonzini *nspte = 2; 5469c50d8ae3SPaolo Bonzini } 5470c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5471c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5472c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5473c50d8ae3SPaolo Bonzini return NULL; 5474c50d8ae3SPaolo Bonzini } 5475c50d8ae3SPaolo Bonzini 5476c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5477c50d8ae3SPaolo Bonzini return spte; 5478c50d8ae3SPaolo Bonzini } 5479c50d8ae3SPaolo Bonzini 5480c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5481c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5482c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5483c50d8ae3SPaolo Bonzini { 5484c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5485c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5486c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5487c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5488c50d8ae3SPaolo Bonzini int npte; 548906152b2dSLai Jiangshan bool flush = false; 5490c50d8ae3SPaolo Bonzini 5491c50d8ae3SPaolo Bonzini /* 5492c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5493c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5494c50d8ae3SPaolo Bonzini */ 5495c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5496c50d8ae3SPaolo Bonzini return; 5497c50d8ae3SPaolo Bonzini 5498c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5499c50d8ae3SPaolo Bonzini 5500531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5501c50d8ae3SPaolo Bonzini 5502c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5503c50d8ae3SPaolo Bonzini 5504c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5505c50d8ae3SPaolo Bonzini 5506767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5507c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5508c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5509c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5510c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5511c50d8ae3SPaolo Bonzini continue; 5512c50d8ae3SPaolo Bonzini } 5513c50d8ae3SPaolo Bonzini 5514c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5515c50d8ae3SPaolo Bonzini if (!spte) 5516c50d8ae3SPaolo Bonzini continue; 5517c50d8ae3SPaolo Bonzini 5518c50d8ae3SPaolo Bonzini while (npte--) { 5519c50d8ae3SPaolo Bonzini entry = *spte; 55202de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5521c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5522c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 55231441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 552406152b2dSLai Jiangshan flush = true; 5525c50d8ae3SPaolo Bonzini ++spte; 5526c50d8ae3SPaolo Bonzini } 5527c50d8ae3SPaolo Bonzini } 552806152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5529531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5530c50d8ae3SPaolo Bonzini } 5531c50d8ae3SPaolo Bonzini 55321075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5533c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5534c50d8ae3SPaolo Bonzini { 553592daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5536347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5537c50d8ae3SPaolo Bonzini 5538b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5539ddce6208SSean Christopherson return RET_PF_RETRY; 5540ddce6208SSean Christopherson 5541c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5542c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5543736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5544c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5545c50d8ae3SPaolo Bonzini goto emulate; 5546c50d8ae3SPaolo Bonzini } 5547c50d8ae3SPaolo Bonzini 5548c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 55497a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 55507a02674dSSean Christopherson lower_32_bits(error_code), false); 555119025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 55527b367bc9SSean Christopherson return -EIO; 5553c50d8ae3SPaolo Bonzini } 5554c50d8ae3SPaolo Bonzini 5555c50d8ae3SPaolo Bonzini if (r < 0) 5556c50d8ae3SPaolo Bonzini return r; 555783a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 555883a2ba4cSSean Christopherson return 1; 5559c50d8ae3SPaolo Bonzini 5560c50d8ae3SPaolo Bonzini /* 5561c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5562c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5563c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5564c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5565c50d8ae3SPaolo Bonzini * and resume the guest. 5566c50d8ae3SPaolo Bonzini */ 5567347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5568c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5569736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5570c50d8ae3SPaolo Bonzini return 1; 5571c50d8ae3SPaolo Bonzini } 5572c50d8ae3SPaolo Bonzini 5573c50d8ae3SPaolo Bonzini /* 5574c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5575c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5576c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5577c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5578c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5579c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5580c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5581c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5582c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5583c50d8ae3SPaolo Bonzini */ 5584736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 558592daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5586c50d8ae3SPaolo Bonzini emulate: 5587736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5588c50d8ae3SPaolo Bonzini insn_len); 5589c50d8ae3SPaolo Bonzini } 5590c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5591c50d8ae3SPaolo Bonzini 55925efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 55935efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5594c50d8ae3SPaolo Bonzini { 5595c50d8ae3SPaolo Bonzini int i; 5596c50d8ae3SPaolo Bonzini 55975efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 55985efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 55995efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5600c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5601c50d8ae3SPaolo Bonzini return; 5602c50d8ae3SPaolo Bonzini 5603e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 56045efac074SPaolo Bonzini } 56055efac074SPaolo Bonzini 56065efac074SPaolo Bonzini if (!mmu->invlpg) 56075efac074SPaolo Bonzini return; 56085efac074SPaolo Bonzini 56095efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5610b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5611c50d8ae3SPaolo Bonzini 5612c50d8ae3SPaolo Bonzini /* 5613c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5614c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5615c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5616c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5617c50d8ae3SPaolo Bonzini * just always sync it. 5618c50d8ae3SPaolo Bonzini * 5619c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5620c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5621c50d8ae3SPaolo Bonzini * for them. 5622c50d8ae3SPaolo Bonzini */ 5623c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5624c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5625c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 56265efac074SPaolo Bonzini } else { 56275efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 56285efac074SPaolo Bonzini } 56295efac074SPaolo Bonzini } 5630c50d8ae3SPaolo Bonzini 56315efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 56325efac074SPaolo Bonzini { 563305b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5634c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5635c50d8ae3SPaolo Bonzini } 5636c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5637c50d8ae3SPaolo Bonzini 56385efac074SPaolo Bonzini 5639c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5640c50d8ae3SPaolo Bonzini { 5641c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5642c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5643c50d8ae3SPaolo Bonzini uint i; 5644c50d8ae3SPaolo Bonzini 5645c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 56469f46c187SPaolo Bonzini if (mmu->invlpg) 5647b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5648c50d8ae3SPaolo Bonzini tlb_flush = true; 5649c50d8ae3SPaolo Bonzini } 5650c50d8ae3SPaolo Bonzini 5651c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5652c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5653be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 56549f46c187SPaolo Bonzini if (mmu->invlpg) 5655c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5656c50d8ae3SPaolo Bonzini tlb_flush = true; 5657c50d8ae3SPaolo Bonzini } 5658c50d8ae3SPaolo Bonzini } 5659c50d8ae3SPaolo Bonzini 5660c50d8ae3SPaolo Bonzini if (tlb_flush) 5661e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5662c50d8ae3SPaolo Bonzini 5663c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5664c50d8ae3SPaolo Bonzini 5665c50d8ae3SPaolo Bonzini /* 5666c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5667c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5668c50d8ae3SPaolo Bonzini * for them. 5669c50d8ae3SPaolo Bonzini */ 5670c50d8ae3SPaolo Bonzini } 5671c50d8ae3SPaolo Bonzini 5672746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5673746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5674c50d8ae3SPaolo Bonzini { 5675bde77235SSean Christopherson tdp_enabled = enable_tdp; 5676746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 567783013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5678703c335dSSean Christopherson 5679703c335dSSean Christopherson /* 56801d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5681703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5682703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5683703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5684703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5685703c335dSSean Christopherson */ 5686703c335dSSean Christopherson if (tdp_enabled) 56871d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5688703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 56891d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5690703c335dSSean Christopherson else 56911d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5692c50d8ae3SPaolo Bonzini } 5693bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5694c50d8ae3SPaolo Bonzini 5695c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5696269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5697269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5698269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5699c50d8ae3SPaolo Bonzini 5700c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5701c50d8ae3SPaolo Bonzini static __always_inline bool 5702269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5703c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 57041a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 57051a61b7dbSSean Christopherson bool flush) 5706c50d8ae3SPaolo Bonzini { 5707c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5708c50d8ae3SPaolo Bonzini 5709c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5710c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5711c50d8ae3SPaolo Bonzini if (iterator.rmap) 57120a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5713c50d8ae3SPaolo Bonzini 5714531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5715302695a5SSean Christopherson if (flush && flush_on_yield) { 5716c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5717c50d8ae3SPaolo Bonzini start_gfn, 5718c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5719c50d8ae3SPaolo Bonzini flush = false; 5720c50d8ae3SPaolo Bonzini } 5721531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5722c50d8ae3SPaolo Bonzini } 5723c50d8ae3SPaolo Bonzini } 5724c50d8ae3SPaolo Bonzini 5725c50d8ae3SPaolo Bonzini return flush; 5726c50d8ae3SPaolo Bonzini } 5727c50d8ae3SPaolo Bonzini 5728c50d8ae3SPaolo Bonzini static __always_inline bool 5729269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5730c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5731302695a5SSean Christopherson bool flush_on_yield) 5732c50d8ae3SPaolo Bonzini { 5733c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5734c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5735c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 57361a61b7dbSSean Christopherson flush_on_yield, false); 5737c50d8ae3SPaolo Bonzini } 5738c50d8ae3SPaolo Bonzini 5739c50d8ae3SPaolo Bonzini static __always_inline bool 5740610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5741302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5742c50d8ae3SPaolo Bonzini { 57433bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5744302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5745c50d8ae3SPaolo Bonzini } 5746c50d8ae3SPaolo Bonzini 5747c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5748c50d8ae3SPaolo Bonzini { 57494a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 57504a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5751c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 575203ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5753cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5754c50d8ae3SPaolo Bonzini } 5755c50d8ae3SPaolo Bonzini 575604d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5757c50d8ae3SPaolo Bonzini { 5758c50d8ae3SPaolo Bonzini struct page *page; 5759c50d8ae3SPaolo Bonzini int i; 5760c50d8ae3SPaolo Bonzini 5761b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5762b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 576304d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 576404d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 576504d28e37SSean Christopherson 576627f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 576727f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 576827f4fca2SLai Jiangshan return 0; 576927f4fca2SLai Jiangshan 5770c50d8ae3SPaolo Bonzini /* 5771c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5772c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5773c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5774c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 577504d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 577604d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 577704d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 577804d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 577984432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5780c50d8ae3SPaolo Bonzini */ 5781d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5782c50d8ae3SPaolo Bonzini return 0; 5783c50d8ae3SPaolo Bonzini 5784c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5785c50d8ae3SPaolo Bonzini if (!page) 5786c50d8ae3SPaolo Bonzini return -ENOMEM; 5787c50d8ae3SPaolo Bonzini 5788c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 57894a98623dSSean Christopherson 57904a98623dSSean Christopherson /* 57914a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 57924a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 57934a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 57944a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 57954a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 57964a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 57974a98623dSSean Christopherson */ 57984a98623dSSean Christopherson if (!tdp_enabled) 57994a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 58004a98623dSSean Christopherson else 5801e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 58024a98623dSSean Christopherson 5803c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5804c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5805c50d8ae3SPaolo Bonzini 5806c50d8ae3SPaolo Bonzini return 0; 5807c50d8ae3SPaolo Bonzini } 5808c50d8ae3SPaolo Bonzini 5809c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5810c50d8ae3SPaolo Bonzini { 5811c50d8ae3SPaolo Bonzini int ret; 5812c50d8ae3SPaolo Bonzini 58135962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 58145f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 58155f6078f9SSean Christopherson 58165962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 58175f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 58185962bfb7SSean Christopherson 581996880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 582096880883SSean Christopherson 5821c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5822c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5823c50d8ae3SPaolo Bonzini 582404d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5825c50d8ae3SPaolo Bonzini if (ret) 5826c50d8ae3SPaolo Bonzini return ret; 5827c50d8ae3SPaolo Bonzini 582804d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5829c50d8ae3SPaolo Bonzini if (ret) 5830c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5831c50d8ae3SPaolo Bonzini 5832c50d8ae3SPaolo Bonzini return ret; 5833c50d8ae3SPaolo Bonzini fail_allocate_root: 5834c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5835c50d8ae3SPaolo Bonzini return ret; 5836c50d8ae3SPaolo Bonzini } 5837c50d8ae3SPaolo Bonzini 5838c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5839c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5840c50d8ae3SPaolo Bonzini { 5841c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5842c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5843b28cb0cdSSean Christopherson bool unstable; 5844c50d8ae3SPaolo Bonzini 5845c50d8ae3SPaolo Bonzini restart: 5846c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5847c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5848c50d8ae3SPaolo Bonzini /* 5849c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5850c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5851c50d8ae3SPaolo Bonzini */ 5852c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5853c50d8ae3SPaolo Bonzini break; 5854c50d8ae3SPaolo Bonzini 5855c50d8ae3SPaolo Bonzini /* 5856f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5857f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5858f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5859c50d8ae3SPaolo Bonzini */ 5860f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5861c50d8ae3SPaolo Bonzini continue; 5862c50d8ae3SPaolo Bonzini 5863c50d8ae3SPaolo Bonzini /* 5864c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5865c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5866c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5867c50d8ae3SPaolo Bonzini * be in active use by the guest. 5868c50d8ae3SPaolo Bonzini */ 5869c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5870531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5871c50d8ae3SPaolo Bonzini batch = 0; 5872c50d8ae3SPaolo Bonzini goto restart; 5873c50d8ae3SPaolo Bonzini } 5874c50d8ae3SPaolo Bonzini 5875b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 5876b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 5877c50d8ae3SPaolo Bonzini batch += nr_zapped; 5878b28cb0cdSSean Christopherson 5879b28cb0cdSSean Christopherson if (unstable) 5880c50d8ae3SPaolo Bonzini goto restart; 5881c50d8ae3SPaolo Bonzini } 5882c50d8ae3SPaolo Bonzini 5883c50d8ae3SPaolo Bonzini /* 58847ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 58857ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 58867ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 58877ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 58887ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 58897ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 58907ae5840eSSean Christopherson * running with an obsolete MMU. 5891c50d8ae3SPaolo Bonzini */ 5892c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5893c50d8ae3SPaolo Bonzini } 5894c50d8ae3SPaolo Bonzini 5895c50d8ae3SPaolo Bonzini /* 5896c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5897c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5898c50d8ae3SPaolo Bonzini * 5899c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5900c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5901c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5902c50d8ae3SPaolo Bonzini * after calling the function. 5903c50d8ae3SPaolo Bonzini */ 5904c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5905c50d8ae3SPaolo Bonzini { 5906c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5907c50d8ae3SPaolo Bonzini 5908531810caSBen Gardon write_lock(&kvm->mmu_lock); 5909c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5910c50d8ae3SPaolo Bonzini 5911c50d8ae3SPaolo Bonzini /* 5912c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5913c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5914c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5915c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5916c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5917c50d8ae3SPaolo Bonzini */ 5918c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5919c50d8ae3SPaolo Bonzini 59202f6f66ccSSean Christopherson /* 59212f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 59222f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 59232f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 59242f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5925b7cccd39SBen Gardon */ 5926b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5927b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5928b7cccd39SBen Gardon 5929c50d8ae3SPaolo Bonzini /* 5930c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5931c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5932c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5933c50d8ae3SPaolo Bonzini * 5934c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5935c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5936c50d8ae3SPaolo Bonzini */ 5937527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5938c50d8ae3SPaolo Bonzini 5939c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5940faaf05b0SBen Gardon 5941531810caSBen Gardon write_unlock(&kvm->mmu_lock); 59424c6654bdSBen Gardon 5943f28e9c7fSSean Christopherson /* 5944f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5945f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5946f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5947f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5948f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5949f28e9c7fSSean Christopherson * lead to use-after-free. 5950f28e9c7fSSean Christopherson */ 595122b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 59524c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5953c50d8ae3SPaolo Bonzini } 5954c50d8ae3SPaolo Bonzini 5955c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5956c50d8ae3SPaolo Bonzini { 5957c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5958c50d8ae3SPaolo Bonzini } 5959c50d8ae3SPaolo Bonzini 5960c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5961c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5962c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5963c50d8ae3SPaolo Bonzini { 5964c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5965c50d8ae3SPaolo Bonzini } 5966c50d8ae3SPaolo Bonzini 5967a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5968c50d8ae3SPaolo Bonzini { 5969c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5970a1a39128SPaolo Bonzini int r; 5971c50d8ae3SPaolo Bonzini 5972a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5973a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5974a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5975ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5976ce25681dSSean Christopherson 5977a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5978a1a39128SPaolo Bonzini if (r < 0) 5979a1a39128SPaolo Bonzini return r; 5980fe5db27dSBen Gardon 5981c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5982c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5983c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5984ada51a9dSDavid Matlack 5985ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 5986ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 5987ada51a9dSDavid Matlack 5988ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 5989ada51a9dSDavid Matlack 5990ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 5991ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 5992ada51a9dSDavid Matlack 5993a1a39128SPaolo Bonzini return 0; 5994c50d8ae3SPaolo Bonzini } 5995c50d8ae3SPaolo Bonzini 5996ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 5997ada51a9dSDavid Matlack { 5998ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 5999ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6000ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6001ada51a9dSDavid Matlack } 6002ada51a9dSDavid Matlack 6003c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6004c50d8ae3SPaolo Bonzini { 6005c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6006c50d8ae3SPaolo Bonzini 6007c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 6008fe5db27dSBen Gardon 6009fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6010ada51a9dSDavid Matlack 6011ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6012c50d8ae3SPaolo Bonzini } 6013c50d8ae3SPaolo Bonzini 60142833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 601521fa3246SSean Christopherson { 601621fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 601721fa3246SSean Christopherson struct kvm_memslots *slots; 6018f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 601921fa3246SSean Christopherson bool flush = false; 602021fa3246SSean Christopherson gfn_t start, end; 6021f4209439SMaciej S. Szmigiero int i; 602221fa3246SSean Christopherson 602321fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 602421fa3246SSean Christopherson return flush; 602521fa3246SSean Christopherson 602621fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 602721fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6028f4209439SMaciej S. Szmigiero 6029f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6030f4209439SMaciej S. Szmigiero memslot = iter.slot; 603121fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 603221fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6033f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 603421fa3246SSean Christopherson continue; 603521fa3246SSean Christopherson 6036f8480721SSean Christopherson flush = slot_handle_level_range(kvm, memslot, __kvm_zap_rmap, 603721fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 603821fa3246SSean Christopherson start, end - 1, true, flush); 603921fa3246SSean Christopherson } 604021fa3246SSean Christopherson } 604121fa3246SSean Christopherson 604221fa3246SSean Christopherson return flush; 604321fa3246SSean Christopherson } 604421fa3246SSean Christopherson 604588f58535SMaxim Levitsky /* 604688f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 604788f58535SMaxim Levitsky * (not including it) 604888f58535SMaxim Levitsky */ 6049c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6050c50d8ae3SPaolo Bonzini { 605121fa3246SSean Christopherson bool flush; 6052c50d8ae3SPaolo Bonzini int i; 6053c50d8ae3SPaolo Bonzini 6054f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6055f4209439SMaciej S. Szmigiero return; 6056f4209439SMaciej S. Szmigiero 6057531810caSBen Gardon write_lock(&kvm->mmu_lock); 60585a324c24SSean Christopherson 605920ec3ebdSChao Peng kvm_mmu_invalidate_begin(kvm, gfn_start, gfn_end); 6060edb298c6SMaxim Levitsky 60612833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 60626103bc07SBen Gardon 60636103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60646103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 6065f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 6066f47e5bbbSSean Christopherson gfn_end, true, flush); 60676103bc07SBen Gardon } 60685a324c24SSean Christopherson 60695a324c24SSean Christopherson if (flush) 6070bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 6071bc3b3c10SSean Christopherson gfn_end - gfn_start); 60725a324c24SSean Christopherson 607320ec3ebdSChao Peng kvm_mmu_invalidate_end(kvm, gfn_start, gfn_end); 6074edb298c6SMaxim Levitsky 60755a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6076c50d8ae3SPaolo Bonzini } 6077c50d8ae3SPaolo Bonzini 6078c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 60790a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6080269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6081c50d8ae3SPaolo Bonzini { 60821346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6083c50d8ae3SPaolo Bonzini } 6084c50d8ae3SPaolo Bonzini 6085c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6086269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 60873c9bd400SJay Zhou int start_level) 6088c50d8ae3SPaolo Bonzini { 6089e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6090531810caSBen Gardon write_lock(&kvm->mmu_lock); 6091b64d740eSJunaid Shahid slot_handle_level(kvm, memslot, slot_rmap_write_protect, 6092b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6093531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6094e2209710SBen Gardon } 6095c50d8ae3SPaolo Bonzini 609624ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 609724ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6098b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 609924ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 610024ae4cfaSBen Gardon } 6101c50d8ae3SPaolo Bonzini } 6102c50d8ae3SPaolo Bonzini 6103ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6104ada51a9dSDavid Matlack { 6105ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6106ada51a9dSDavid Matlack } 6107ada51a9dSDavid Matlack 6108ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6109ada51a9dSDavid Matlack { 6110ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6111ada51a9dSDavid Matlack return true; 6112ada51a9dSDavid Matlack 6113ada51a9dSDavid Matlack /* 6114ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6115ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6116ada51a9dSDavid Matlack * is possible but not worth the complexity. 6117ada51a9dSDavid Matlack */ 6118ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6119ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6120ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6121ada51a9dSDavid Matlack } 6122ada51a9dSDavid Matlack 6123ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6124ada51a9dSDavid Matlack { 6125b9b71f43SSean Christopherson /* 6126b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6127dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6128b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6129dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6130dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6131dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6132dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6133dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6134dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6135dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6136b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6137b9b71f43SSean Christopherson */ 6138b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6139b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6140ada51a9dSDavid Matlack int r; 6141ada51a9dSDavid Matlack 6142ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6143ada51a9dSDavid Matlack 6144b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6145ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6146ada51a9dSDavid Matlack if (r) 6147ada51a9dSDavid Matlack return r; 6148ada51a9dSDavid Matlack 6149ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6150ada51a9dSDavid Matlack if (r) 6151ada51a9dSDavid Matlack return r; 6152ada51a9dSDavid Matlack 6153ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6154ada51a9dSDavid Matlack } 6155ada51a9dSDavid Matlack 6156ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6157ada51a9dSDavid Matlack { 6158ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6159ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6160ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6161ada51a9dSDavid Matlack unsigned int access; 6162ada51a9dSDavid Matlack gfn_t gfn; 6163ada51a9dSDavid Matlack 616479e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 616579e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6166ada51a9dSDavid Matlack 6167ada51a9dSDavid Matlack /* 6168ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6169ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6170ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6171ada51a9dSDavid Matlack * mapped with smaller pages. 6172ada51a9dSDavid Matlack */ 6173ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6174ada51a9dSDavid Matlack 6175ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6176ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6177ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6178ada51a9dSDavid Matlack 6179ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6180ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6181ada51a9dSDavid Matlack } 6182ada51a9dSDavid Matlack 6183ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6184ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6185ada51a9dSDavid Matlack u64 *huge_sptep) 6186ada51a9dSDavid Matlack 6187ada51a9dSDavid Matlack { 6188ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6189ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6190ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 619103787394SPaolo Bonzini bool flush = false; 6192ada51a9dSDavid Matlack u64 *sptep, spte; 6193ada51a9dSDavid Matlack gfn_t gfn; 6194ada51a9dSDavid Matlack int index; 6195ada51a9dSDavid Matlack 6196ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6197ada51a9dSDavid Matlack 6198ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6199ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6200ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6201ada51a9dSDavid Matlack 6202ada51a9dSDavid Matlack /* 6203ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6204ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6205ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6206ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6207ada51a9dSDavid Matlack * modify them. 6208ada51a9dSDavid Matlack * 620903787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 621003787394SPaolo Bonzini * that lower level page table may only be partially populated. 621103787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 621203787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 621303787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 621403787394SPaolo Bonzini * fail to detect the need to flush. 6215ada51a9dSDavid Matlack */ 621603787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 621703787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6218ada51a9dSDavid Matlack continue; 621903787394SPaolo Bonzini } 6220ada51a9dSDavid Matlack 6221ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6222ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6223ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6224ada51a9dSDavid Matlack } 6225ada51a9dSDavid Matlack 622603787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6227ada51a9dSDavid Matlack } 6228ada51a9dSDavid Matlack 6229ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6230ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6231ada51a9dSDavid Matlack u64 *huge_sptep) 6232ada51a9dSDavid Matlack { 6233ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6234ada51a9dSDavid Matlack int level, r = 0; 6235ada51a9dSDavid Matlack gfn_t gfn; 6236ada51a9dSDavid Matlack u64 spte; 6237ada51a9dSDavid Matlack 6238ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 623979e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6240ada51a9dSDavid Matlack level = huge_sp->role.level; 6241ada51a9dSDavid Matlack spte = *huge_sptep; 6242ada51a9dSDavid Matlack 6243ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6244ada51a9dSDavid Matlack r = -ENOSPC; 6245ada51a9dSDavid Matlack goto out; 6246ada51a9dSDavid Matlack } 6247ada51a9dSDavid Matlack 6248ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6249ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6250ada51a9dSDavid Matlack cond_resched(); 6251ada51a9dSDavid Matlack /* 6252ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6253ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6254ada51a9dSDavid Matlack * dropped. 6255ada51a9dSDavid Matlack */ 6256ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6257ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6258ada51a9dSDavid Matlack goto out; 6259ada51a9dSDavid Matlack } 6260ada51a9dSDavid Matlack 6261ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6262ada51a9dSDavid Matlack 6263ada51a9dSDavid Matlack out: 6264ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6265ada51a9dSDavid Matlack return r; 6266ada51a9dSDavid Matlack } 6267ada51a9dSDavid Matlack 6268ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6269ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6270ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6271ada51a9dSDavid Matlack { 6272ada51a9dSDavid Matlack struct rmap_iterator iter; 6273ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6274ada51a9dSDavid Matlack u64 *huge_sptep; 6275ada51a9dSDavid Matlack int r; 6276ada51a9dSDavid Matlack 6277ada51a9dSDavid Matlack restart: 6278ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6279ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6280ada51a9dSDavid Matlack 6281ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6282ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6283ada51a9dSDavid Matlack continue; 6284ada51a9dSDavid Matlack 6285ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6286ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6287ada51a9dSDavid Matlack continue; 6288ada51a9dSDavid Matlack 6289ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6290ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6291ada51a9dSDavid Matlack continue; 6292ada51a9dSDavid Matlack 6293ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6294ada51a9dSDavid Matlack if (sp->role.invalid) 6295ada51a9dSDavid Matlack continue; 6296ada51a9dSDavid Matlack 6297ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6298ada51a9dSDavid Matlack 6299ada51a9dSDavid Matlack /* 6300ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6301ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6302ada51a9dSDavid Matlack * back into a consistent state. 6303ada51a9dSDavid Matlack */ 6304ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6305ada51a9dSDavid Matlack goto restart; 6306ada51a9dSDavid Matlack 6307ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6308ada51a9dSDavid Matlack break; 6309ada51a9dSDavid Matlack } 6310ada51a9dSDavid Matlack 6311ada51a9dSDavid Matlack return false; 6312ada51a9dSDavid Matlack } 6313ada51a9dSDavid Matlack 6314ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6315ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6316ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6317ada51a9dSDavid Matlack int target_level) 6318ada51a9dSDavid Matlack { 6319ada51a9dSDavid Matlack int level; 6320ada51a9dSDavid Matlack 6321ada51a9dSDavid Matlack /* 6322ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6323ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6324ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6325ada51a9dSDavid Matlack * already at the target level. 6326ada51a9dSDavid Matlack */ 6327ada51a9dSDavid Matlack for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) { 6328ada51a9dSDavid Matlack slot_handle_level_range(kvm, slot, shadow_mmu_try_split_huge_pages, 6329ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6330ada51a9dSDavid Matlack } 6331ada51a9dSDavid Matlack } 6332ada51a9dSDavid Matlack 6333cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6334cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6335cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6336cb00a70bSDavid Matlack u64 start, u64 end, 6337cb00a70bSDavid Matlack int target_level) 6338cb00a70bSDavid Matlack { 6339ada51a9dSDavid Matlack if (!is_tdp_mmu_enabled(kvm)) 6340ada51a9dSDavid Matlack return; 6341ada51a9dSDavid Matlack 6342ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6343ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6344ada51a9dSDavid Matlack 6345ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6346cb00a70bSDavid Matlack 6347cb00a70bSDavid Matlack /* 6348cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6349cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6350cb00a70bSDavid Matlack */ 6351cb00a70bSDavid Matlack } 6352cb00a70bSDavid Matlack 6353a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6354a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6355a3fe5dbdSDavid Matlack int target_level) 6356a3fe5dbdSDavid Matlack { 6357a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6358a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6359a3fe5dbdSDavid Matlack 6360ada51a9dSDavid Matlack if (!is_tdp_mmu_enabled(kvm)) 6361ada51a9dSDavid Matlack return; 6362ada51a9dSDavid Matlack 6363ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6364ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6365ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6366ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6367ada51a9dSDavid Matlack } 6368ada51a9dSDavid Matlack 6369a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6370cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6371a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6372a3fe5dbdSDavid Matlack 6373a3fe5dbdSDavid Matlack /* 6374a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6375a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6376a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6377a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6378a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6379a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6380a3fe5dbdSDavid Matlack * SPTEs. 6381a3fe5dbdSDavid Matlack */ 6382a3fe5dbdSDavid Matlack } 6383a3fe5dbdSDavid Matlack 6384c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 63850a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6386269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6387c50d8ae3SPaolo Bonzini { 6388c50d8ae3SPaolo Bonzini u64 *sptep; 6389c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6390c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6391c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6392c50d8ae3SPaolo Bonzini 6393c50d8ae3SPaolo Bonzini restart: 6394c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 639557354682SSean Christopherson sp = sptep_to_sp(sptep); 6396c50d8ae3SPaolo Bonzini 6397c50d8ae3SPaolo Bonzini /* 6398c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6399c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6400c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6401c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6402c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6403c50d8ae3SPaolo Bonzini */ 64045d49f08cSSean Christopherson if (sp->role.direct && 64059eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6406a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 64079202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6408c50d8ae3SPaolo Bonzini 6409c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6410c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6411c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6412c50d8ae3SPaolo Bonzini else 6413c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6414c50d8ae3SPaolo Bonzini 6415c50d8ae3SPaolo Bonzini goto restart; 6416c50d8ae3SPaolo Bonzini } 6417c50d8ae3SPaolo Bonzini } 6418c50d8ae3SPaolo Bonzini 6419c50d8ae3SPaolo Bonzini return need_tlb_flush; 6420c50d8ae3SPaolo Bonzini } 6421c50d8ae3SPaolo Bonzini 642220d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 642320d49186SDavid Matlack const struct kvm_memory_slot *slot) 642420d49186SDavid Matlack { 642520d49186SDavid Matlack /* 642620d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 642720d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 642820d49186SDavid Matlack */ 642920d49186SDavid Matlack if (slot_handle_level(kvm, slot, kvm_mmu_zap_collapsible_spte, 643020d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 643120d49186SDavid Matlack kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 643220d49186SDavid Matlack } 643320d49186SDavid Matlack 6434c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6435269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6436c50d8ae3SPaolo Bonzini { 6437e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6438531810caSBen Gardon write_lock(&kvm->mmu_lock); 643920d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6440531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6441e2209710SBen Gardon } 64422db6f772SBen Gardon 64432db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 64442db6f772SBen Gardon read_lock(&kvm->mmu_lock); 64454b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 64462db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 64472db6f772SBen Gardon } 6448c50d8ae3SPaolo Bonzini } 6449c50d8ae3SPaolo Bonzini 6450b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 64516c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6452b3594ffbSSean Christopherson { 6453b3594ffbSSean Christopherson /* 64547f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6455302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 64567f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 64577f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 64587f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6459b3594ffbSSean Christopherson */ 6460b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6461cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6462cec37648SSean Christopherson memslot->npages); 6463b3594ffbSSean Christopherson } 6464b3594ffbSSean Christopherson 6465c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6466269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6467c50d8ae3SPaolo Bonzini { 6468e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6469531810caSBen Gardon write_lock(&kvm->mmu_lock); 6470610265eaSDavid Matlack /* 6471610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6472610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6473610265eaSDavid Matlack */ 6474b64d740eSJunaid Shahid slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6475531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6476e2209710SBen Gardon } 6477c50d8ae3SPaolo Bonzini 647824ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 647924ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6480b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 648124ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 648224ae4cfaSBen Gardon } 648324ae4cfaSBen Gardon 6484c50d8ae3SPaolo Bonzini /* 6485b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6486b64d740eSJunaid Shahid * 6487c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6488c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6489c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6490c50d8ae3SPaolo Bonzini * dirty_bitmap. 6491c50d8ae3SPaolo Bonzini */ 6492c50d8ae3SPaolo Bonzini } 6493c50d8ae3SPaolo Bonzini 6494c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6495c50d8ae3SPaolo Bonzini { 6496c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6497c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6498c50d8ae3SPaolo Bonzini int ign; 6499c50d8ae3SPaolo Bonzini 6500531810caSBen Gardon write_lock(&kvm->mmu_lock); 6501c50d8ae3SPaolo Bonzini restart: 6502c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6503f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6504c50d8ae3SPaolo Bonzini continue; 6505c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6506c50d8ae3SPaolo Bonzini goto restart; 6507531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6508c50d8ae3SPaolo Bonzini goto restart; 6509c50d8ae3SPaolo Bonzini } 6510c50d8ae3SPaolo Bonzini 6511c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6512faaf05b0SBen Gardon 6513897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6514faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6515faaf05b0SBen Gardon 6516531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6517c50d8ae3SPaolo Bonzini } 6518c50d8ae3SPaolo Bonzini 6519c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6520c50d8ae3SPaolo Bonzini { 6521c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6522c50d8ae3SPaolo Bonzini 6523c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6524c50d8ae3SPaolo Bonzini 6525c50d8ae3SPaolo Bonzini /* 6526c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6527c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6528c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6529c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6530c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6531c50d8ae3SPaolo Bonzini */ 6532c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6533c50d8ae3SPaolo Bonzini 6534c50d8ae3SPaolo Bonzini /* 6535c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6536c50d8ae3SPaolo Bonzini * zap all shadow pages. 6537c50d8ae3SPaolo Bonzini */ 6538c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6539c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6540c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6541c50d8ae3SPaolo Bonzini } 6542c50d8ae3SPaolo Bonzini } 6543c50d8ae3SPaolo Bonzini 6544c50d8ae3SPaolo Bonzini static unsigned long 6545c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6546c50d8ae3SPaolo Bonzini { 6547c50d8ae3SPaolo Bonzini struct kvm *kvm; 6548c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6549c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6550c50d8ae3SPaolo Bonzini 6551c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6552c50d8ae3SPaolo Bonzini 6553c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6554c50d8ae3SPaolo Bonzini int idx; 6555c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6556c50d8ae3SPaolo Bonzini 6557c50d8ae3SPaolo Bonzini /* 6558c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6559c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6560c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6561c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6562c50d8ae3SPaolo Bonzini */ 6563c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6564c50d8ae3SPaolo Bonzini break; 6565c50d8ae3SPaolo Bonzini /* 6566c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6567c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6568c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6569c50d8ae3SPaolo Bonzini * anyway. 6570c50d8ae3SPaolo Bonzini */ 6571c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6572c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6573c50d8ae3SPaolo Bonzini continue; 6574c50d8ae3SPaolo Bonzini 6575c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6576531810caSBen Gardon write_lock(&kvm->mmu_lock); 6577c50d8ae3SPaolo Bonzini 6578c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6579c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6580c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6581c50d8ae3SPaolo Bonzini goto unlock; 6582c50d8ae3SPaolo Bonzini } 6583c50d8ae3SPaolo Bonzini 6584ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6585c50d8ae3SPaolo Bonzini 6586c50d8ae3SPaolo Bonzini unlock: 6587531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6588c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6589c50d8ae3SPaolo Bonzini 6590c50d8ae3SPaolo Bonzini /* 6591c50d8ae3SPaolo Bonzini * unfair on small ones 6592c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6593c50d8ae3SPaolo Bonzini * sadness comes quickly 6594c50d8ae3SPaolo Bonzini */ 6595c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6596c50d8ae3SPaolo Bonzini break; 6597c50d8ae3SPaolo Bonzini } 6598c50d8ae3SPaolo Bonzini 6599c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6600c50d8ae3SPaolo Bonzini return freed; 6601c50d8ae3SPaolo Bonzini } 6602c50d8ae3SPaolo Bonzini 6603c50d8ae3SPaolo Bonzini static unsigned long 6604c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6605c50d8ae3SPaolo Bonzini { 6606c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6607c50d8ae3SPaolo Bonzini } 6608c50d8ae3SPaolo Bonzini 6609c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6610c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6611c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6612c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6613c50d8ae3SPaolo Bonzini }; 6614c50d8ae3SPaolo Bonzini 6615c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6616c50d8ae3SPaolo Bonzini { 6617c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6618c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6619c50d8ae3SPaolo Bonzini } 6620c50d8ae3SPaolo Bonzini 6621c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6622c50d8ae3SPaolo Bonzini { 6623c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6624c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6625c50d8ae3SPaolo Bonzini } 6626c50d8ae3SPaolo Bonzini 6627c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6628c50d8ae3SPaolo Bonzini { 6629c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6630c50d8ae3SPaolo Bonzini } 6631c50d8ae3SPaolo Bonzini 6632c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6633c50d8ae3SPaolo Bonzini { 6634c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6635c50d8ae3SPaolo Bonzini bool new_val; 6636c50d8ae3SPaolo Bonzini 6637c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6638c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6639c50d8ae3SPaolo Bonzini new_val = 0; 6640c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6641c50d8ae3SPaolo Bonzini new_val = 1; 6642c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6643c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6644c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6645c50d8ae3SPaolo Bonzini return -EINVAL; 6646c50d8ae3SPaolo Bonzini 6647c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6648c50d8ae3SPaolo Bonzini 6649c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6650c50d8ae3SPaolo Bonzini struct kvm *kvm; 6651c50d8ae3SPaolo Bonzini 6652c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6653c50d8ae3SPaolo Bonzini 6654c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6655c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6656c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6657c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6658c50d8ae3SPaolo Bonzini 6659c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6660c50d8ae3SPaolo Bonzini } 6661c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6662c50d8ae3SPaolo Bonzini } 6663c50d8ae3SPaolo Bonzini 6664c50d8ae3SPaolo Bonzini return 0; 6665c50d8ae3SPaolo Bonzini } 6666c50d8ae3SPaolo Bonzini 66671d0e8480SSean Christopherson /* 66681d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 66691d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 6670c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 6671c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 66721d0e8480SSean Christopherson */ 6673982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 6674c50d8ae3SPaolo Bonzini { 6675c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6676c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 6677c3e0c8c2SSean Christopherson 6678c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 66791d0e8480SSean Christopherson } 66801d0e8480SSean Christopherson 66811d0e8480SSean Christopherson /* 66821d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 66831d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 66841d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 66851d0e8480SSean Christopherson */ 66861d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 66871d0e8480SSean Christopherson { 66881d0e8480SSean Christopherson int ret = -ENOMEM; 6689c50d8ae3SPaolo Bonzini 6690c50d8ae3SPaolo Bonzini /* 6691c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6692c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6693c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6694c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6695c50d8ae3SPaolo Bonzini */ 6696c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6697c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 66987a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6699c50d8ae3SPaolo Bonzini 6700c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6701c50d8ae3SPaolo Bonzini 6702c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6703c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6704c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6705c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6706c50d8ae3SPaolo Bonzini goto out; 6707c50d8ae3SPaolo Bonzini 6708c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6709c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6710c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6711c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6712c50d8ae3SPaolo Bonzini goto out; 6713c50d8ae3SPaolo Bonzini 6714c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6715c50d8ae3SPaolo Bonzini goto out; 6716c50d8ae3SPaolo Bonzini 6717e33c267aSRoman Gushchin ret = register_shrinker(&mmu_shrinker, "x86-mmu"); 6718c50d8ae3SPaolo Bonzini if (ret) 6719d7c9bfb9SMiaohe Lin goto out_shrinker; 6720c50d8ae3SPaolo Bonzini 6721c50d8ae3SPaolo Bonzini return 0; 6722c50d8ae3SPaolo Bonzini 6723d7c9bfb9SMiaohe Lin out_shrinker: 6724d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 6725c50d8ae3SPaolo Bonzini out: 6726c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6727c50d8ae3SPaolo Bonzini return ret; 6728c50d8ae3SPaolo Bonzini } 6729c50d8ae3SPaolo Bonzini 6730c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6731c50d8ae3SPaolo Bonzini { 6732c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6733c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6734c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6735c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6736c50d8ae3SPaolo Bonzini } 6737c50d8ae3SPaolo Bonzini 67381d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6739c50d8ae3SPaolo Bonzini { 6740c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6741c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6742c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6743c50d8ae3SPaolo Bonzini } 6744c50d8ae3SPaolo Bonzini 6745f47491d7SSean Christopherson /* 6746f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6747f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6748f47491d7SSean Christopherson */ 6749f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6750f47491d7SSean Christopherson { 6751f47491d7SSean Christopherson /* 6752f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6753f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6754f47491d7SSean Christopherson */ 6755f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6756f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6757f47491d7SSean Christopherson 6758f47491d7SSean Christopherson if (!enabled || !ratio) 6759f47491d7SSean Christopherson return false; 6760f47491d7SSean Christopherson 6761f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6762f47491d7SSean Christopherson if (!*period) { 6763f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6764f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6765f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6766f47491d7SSean Christopherson } 6767f47491d7SSean Christopherson return true; 6768f47491d7SSean Christopherson } 6769f47491d7SSean Christopherson 67704dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6771c50d8ae3SPaolo Bonzini { 67724dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 67734dfe4f40SJunaid Shahid uint old_period, new_period; 6774c50d8ae3SPaolo Bonzini int err; 6775c50d8ae3SPaolo Bonzini 6776f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 67774dfe4f40SJunaid Shahid 6778c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6779c50d8ae3SPaolo Bonzini if (err) 6780c50d8ae3SPaolo Bonzini return err; 6781c50d8ae3SPaolo Bonzini 6782f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 67834dfe4f40SJunaid Shahid 6784f47491d7SSean Christopherson if (is_recovery_enabled && 67854dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6786c50d8ae3SPaolo Bonzini struct kvm *kvm; 6787c50d8ae3SPaolo Bonzini 6788c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6789c50d8ae3SPaolo Bonzini 6790c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6791c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6792c50d8ae3SPaolo Bonzini 6793c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6794c50d8ae3SPaolo Bonzini } 6795c50d8ae3SPaolo Bonzini 6796c50d8ae3SPaolo Bonzini return err; 6797c50d8ae3SPaolo Bonzini } 6798c50d8ae3SPaolo Bonzini 6799c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6800c50d8ae3SPaolo Bonzini { 6801ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6802c50d8ae3SPaolo Bonzini int rcu_idx; 6803c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6804c50d8ae3SPaolo Bonzini unsigned int ratio; 6805c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6806048f4980SSean Christopherson bool flush = false; 6807c50d8ae3SPaolo Bonzini ulong to_zap; 6808c50d8ae3SPaolo Bonzini 6809c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6810531810caSBen Gardon write_lock(&kvm->mmu_lock); 6811c50d8ae3SPaolo Bonzini 6812bb95dfb9SSean Christopherson /* 6813bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6814bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6815bb95dfb9SSean Christopherson * callback. 6816bb95dfb9SSean Christopherson */ 6817bb95dfb9SSean Christopherson rcu_read_lock(); 6818bb95dfb9SSean Christopherson 6819c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6820ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 68217d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 68227d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 68237d919c7aSSean Christopherson break; 68247d919c7aSSean Christopherson 6825c50d8ae3SPaolo Bonzini /* 6826c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6827c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6828c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6829c50d8ae3SPaolo Bonzini */ 6830c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6831c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6832c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6833c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6834897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6835315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 68368d1a182eSBen Gardon } else { 6837c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6838c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 683929cf0f50SBen Gardon } 6840c50d8ae3SPaolo Bonzini 6841531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6842048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6843bb95dfb9SSean Christopherson rcu_read_unlock(); 6844bb95dfb9SSean Christopherson 6845531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6846048f4980SSean Christopherson flush = false; 6847bb95dfb9SSean Christopherson 6848bb95dfb9SSean Christopherson rcu_read_lock(); 6849c50d8ae3SPaolo Bonzini } 6850c50d8ae3SPaolo Bonzini } 6851048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6852c50d8ae3SPaolo Bonzini 6853bb95dfb9SSean Christopherson rcu_read_unlock(); 6854bb95dfb9SSean Christopherson 6855531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6856c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6857c50d8ae3SPaolo Bonzini } 6858c50d8ae3SPaolo Bonzini 6859c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6860c50d8ae3SPaolo Bonzini { 6861f47491d7SSean Christopherson bool enabled; 6862f47491d7SSean Christopherson uint period; 68634dfe4f40SJunaid Shahid 6864f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 68654dfe4f40SJunaid Shahid 6866f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6867c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6868c50d8ae3SPaolo Bonzini } 6869c50d8ae3SPaolo Bonzini 6870c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6871c50d8ae3SPaolo Bonzini { 6872c50d8ae3SPaolo Bonzini u64 start_time; 6873c50d8ae3SPaolo Bonzini long remaining_time; 6874c50d8ae3SPaolo Bonzini 6875c50d8ae3SPaolo Bonzini while (true) { 6876c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6877c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6878c50d8ae3SPaolo Bonzini 6879c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6880c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6881c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6882c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6883c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6884c50d8ae3SPaolo Bonzini } 6885c50d8ae3SPaolo Bonzini 6886c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6887c50d8ae3SPaolo Bonzini 6888c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6889c50d8ae3SPaolo Bonzini return 0; 6890c50d8ae3SPaolo Bonzini 6891c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6892c50d8ae3SPaolo Bonzini } 6893c50d8ae3SPaolo Bonzini } 6894c50d8ae3SPaolo Bonzini 6895c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6896c50d8ae3SPaolo Bonzini { 6897c50d8ae3SPaolo Bonzini int err; 6898c50d8ae3SPaolo Bonzini 6899c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6900c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6901c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6902c50d8ae3SPaolo Bonzini if (!err) 6903c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6904c50d8ae3SPaolo Bonzini 6905c50d8ae3SPaolo Bonzini return err; 6906c50d8ae3SPaolo Bonzini } 6907c50d8ae3SPaolo Bonzini 6908c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6909c50d8ae3SPaolo Bonzini { 6910c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6911c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6912c50d8ae3SPaolo Bonzini } 6913