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 * 406c50d8ae3SPaolo Bonzini * An spte tlb flush may be pending, because kvm_set_pte_rmapp 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 */ 53271f51d2cSMingwei Zhang static int 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) { 659*6a97575dSDavid 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); 672*6a97575dSDavid 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 681*6a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 682*6a97575dSDavid 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) 689*6a97575dSDavid 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 694*6a97575dSDavid Matlack /* 695*6a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 696*6a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 697*6a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 698*6a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 699*6a97575dSDavid Matlack */ 700*6a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 701c50d8ae3SPaolo Bonzini { 702*6a97575dSDavid Matlack if (sp_has_gptes(sp)) 703*6a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 704*6a97575dSDavid Matlack 705*6a97575dSDavid Matlack /* 706*6a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 707*6a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 708*6a97575dSDavid Matlack * permissions" are just ACC_ALL. 709*6a97575dSDavid Matlack * 710*6a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 711*6a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 712*6a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 713*6a97575dSDavid Matlack * page. 714*6a97575dSDavid Matlack * 715*6a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 716*6a97575dSDavid Matlack */ 717*6a97575dSDavid Matlack return sp->role.access; 718*6a97575dSDavid Matlack } 719*6a97575dSDavid Matlack 720*6a97575dSDavid Matlack static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, gfn_t gfn, u32 access) 721*6a97575dSDavid Matlack { 722*6a97575dSDavid Matlack if (sp_has_gptes(sp)) { 723*6a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 72484e5ffd0SLai Jiangshan return; 72584e5ffd0SLai Jiangshan } 72684e5ffd0SLai Jiangshan 727*6a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 728*6a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 729*6a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 730*6a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 731*6a97575dSDavid Matlack 732*6a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 733*6a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 734*6a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 735*6a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 736c50d8ae3SPaolo Bonzini } 737c50d8ae3SPaolo Bonzini 738*6a97575dSDavid Matlack static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, u32 access) 739*6a97575dSDavid Matlack { 740*6a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 741*6a97575dSDavid Matlack 742*6a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 743c50d8ae3SPaolo Bonzini } 744c50d8ae3SPaolo Bonzini 745c50d8ae3SPaolo Bonzini /* 746c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 747c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 748c50d8ae3SPaolo Bonzini */ 749c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7508ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 751c50d8ae3SPaolo Bonzini { 752c50d8ae3SPaolo Bonzini unsigned long idx; 753c50d8ae3SPaolo Bonzini 754c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 755c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 756c50d8ae3SPaolo Bonzini } 757c50d8ae3SPaolo Bonzini 758269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 759c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 760c50d8ae3SPaolo Bonzini { 761c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 762c50d8ae3SPaolo Bonzini int i; 763c50d8ae3SPaolo Bonzini 7643bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 765c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 766c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 767c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 768c50d8ae3SPaolo Bonzini } 769c50d8ae3SPaolo Bonzini } 770c50d8ae3SPaolo Bonzini 771269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 772c50d8ae3SPaolo Bonzini { 773c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 774c50d8ae3SPaolo Bonzini } 775c50d8ae3SPaolo Bonzini 776269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 777c50d8ae3SPaolo Bonzini { 778c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 779c50d8ae3SPaolo Bonzini } 780c50d8ae3SPaolo Bonzini 781c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 782c50d8ae3SPaolo Bonzini { 783c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 784c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 785c50d8ae3SPaolo Bonzini gfn_t gfn; 786c50d8ae3SPaolo Bonzini 787c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 788c50d8ae3SPaolo Bonzini gfn = sp->gfn; 789c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 790c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 791c50d8ae3SPaolo Bonzini 792c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 7933bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 794c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 795c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 796c50d8ae3SPaolo Bonzini 797c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 798be911771SDavid Matlack 799be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 800be911771SDavid Matlack kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 801c50d8ae3SPaolo Bonzini } 802c50d8ae3SPaolo Bonzini 80329cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 804c50d8ae3SPaolo Bonzini { 805c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 806c50d8ae3SPaolo Bonzini return; 807c50d8ae3SPaolo Bonzini 808c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 809c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 810c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 811c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 812c50d8ae3SPaolo Bonzini } 813c50d8ae3SPaolo Bonzini 814c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 815c50d8ae3SPaolo Bonzini { 816c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 817c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 818c50d8ae3SPaolo Bonzini gfn_t gfn; 819c50d8ae3SPaolo Bonzini 820c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 821c50d8ae3SPaolo Bonzini gfn = sp->gfn; 822c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 823c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8243bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 825c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 826c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 827c50d8ae3SPaolo Bonzini 828c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 829c50d8ae3SPaolo Bonzini } 830c50d8ae3SPaolo Bonzini 83129cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 832c50d8ae3SPaolo Bonzini { 833c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 834c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 835c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 836c50d8ae3SPaolo Bonzini } 837c50d8ae3SPaolo Bonzini 838c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 839c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 840c50d8ae3SPaolo Bonzini bool no_dirty_log) 841c50d8ae3SPaolo Bonzini { 842c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 843c50d8ae3SPaolo Bonzini 844c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 84591b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 84691b0d268SPaolo Bonzini return NULL; 847044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 84891b0d268SPaolo Bonzini return NULL; 849c50d8ae3SPaolo Bonzini 850c50d8ae3SPaolo Bonzini return slot; 851c50d8ae3SPaolo Bonzini } 852c50d8ae3SPaolo Bonzini 853c50d8ae3SPaolo Bonzini /* 854c50d8ae3SPaolo Bonzini * About rmap_head encoding: 855c50d8ae3SPaolo Bonzini * 856c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 857c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 858c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 859c50d8ae3SPaolo Bonzini */ 860c50d8ae3SPaolo Bonzini 861c50d8ae3SPaolo Bonzini /* 862c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 863c50d8ae3SPaolo Bonzini */ 8642ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 865c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 866c50d8ae3SPaolo Bonzini { 867c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 86813236e25SPeter Xu int count = 0; 869c50d8ae3SPaolo Bonzini 870c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 871805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 872c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 873c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 874805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 8752ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 876c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 877c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 87813236e25SPeter Xu desc->spte_count = 2; 879c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 880c50d8ae3SPaolo Bonzini ++count; 881c50d8ae3SPaolo Bonzini } else { 882805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 883c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 88413236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 885c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 886c6c4f961SLi RongQing if (!desc->more) { 8872ff9039aSDavid Matlack desc->more = kvm_mmu_memory_cache_alloc(cache); 888c50d8ae3SPaolo Bonzini desc = desc->more; 88913236e25SPeter Xu desc->spte_count = 0; 890c6c4f961SLi RongQing break; 891c6c4f961SLi RongQing } 892c6c4f961SLi RongQing desc = desc->more; 893c50d8ae3SPaolo Bonzini } 89413236e25SPeter Xu count += desc->spte_count; 89513236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 896c50d8ae3SPaolo Bonzini } 897c50d8ae3SPaolo Bonzini return count; 898c50d8ae3SPaolo Bonzini } 899c50d8ae3SPaolo Bonzini 900c50d8ae3SPaolo Bonzini static void 901c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 902c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 903c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 904c50d8ae3SPaolo Bonzini { 90513236e25SPeter Xu int j = desc->spte_count - 1; 906c50d8ae3SPaolo Bonzini 907c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 908c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 90913236e25SPeter Xu desc->spte_count--; 91013236e25SPeter Xu if (desc->spte_count) 911c50d8ae3SPaolo Bonzini return; 912c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 913fe3c2b4cSMiaohe Lin rmap_head->val = 0; 914c50d8ae3SPaolo Bonzini else 915c50d8ae3SPaolo Bonzini if (prev_desc) 916c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 917c50d8ae3SPaolo Bonzini else 918c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 919c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 920c50d8ae3SPaolo Bonzini } 921c50d8ae3SPaolo Bonzini 922c50d8ae3SPaolo Bonzini static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 923c50d8ae3SPaolo Bonzini { 924c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 925c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 926c50d8ae3SPaolo Bonzini int i; 927c50d8ae3SPaolo Bonzini 928c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 929c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 930c50d8ae3SPaolo Bonzini BUG(); 931c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 932805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 933c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 934c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 935c50d8ae3SPaolo Bonzini BUG(); 936c50d8ae3SPaolo Bonzini } 937c50d8ae3SPaolo Bonzini rmap_head->val = 0; 938c50d8ae3SPaolo Bonzini } else { 939805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 940c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 941c50d8ae3SPaolo Bonzini prev_desc = NULL; 942c50d8ae3SPaolo Bonzini while (desc) { 94313236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 944c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 945c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 946c50d8ae3SPaolo Bonzini desc, i, prev_desc); 947c50d8ae3SPaolo Bonzini return; 948c50d8ae3SPaolo Bonzini } 949c50d8ae3SPaolo Bonzini } 950c50d8ae3SPaolo Bonzini prev_desc = desc; 951c50d8ae3SPaolo Bonzini desc = desc->more; 952c50d8ae3SPaolo Bonzini } 953c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 954c50d8ae3SPaolo Bonzini BUG(); 955c50d8ae3SPaolo Bonzini } 956c50d8ae3SPaolo Bonzini } 957c50d8ae3SPaolo Bonzini 95871f51d2cSMingwei Zhang static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 95971f51d2cSMingwei Zhang u64 *sptep) 960c50d8ae3SPaolo Bonzini { 96171f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 962c50d8ae3SPaolo Bonzini __pte_list_remove(sptep, rmap_head); 963c50d8ae3SPaolo Bonzini } 964c50d8ae3SPaolo Bonzini 965a75b5404SPeter Xu /* Return true if rmap existed, false otherwise */ 96671f51d2cSMingwei Zhang static bool pte_list_destroy(struct kvm *kvm, struct kvm_rmap_head *rmap_head) 967a75b5404SPeter Xu { 968a75b5404SPeter Xu struct pte_list_desc *desc, *next; 969a75b5404SPeter Xu int i; 970a75b5404SPeter Xu 971a75b5404SPeter Xu if (!rmap_head->val) 972a75b5404SPeter Xu return false; 973a75b5404SPeter Xu 974a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 97571f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 976a75b5404SPeter Xu goto out; 977a75b5404SPeter Xu } 978a75b5404SPeter Xu 979a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 980a75b5404SPeter Xu 981a75b5404SPeter Xu for (; desc; desc = next) { 982a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 98371f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 984a75b5404SPeter Xu next = desc->more; 985a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 986a75b5404SPeter Xu } 987a75b5404SPeter Xu out: 988a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 989a75b5404SPeter Xu rmap_head->val = 0; 990a75b5404SPeter Xu return true; 991a75b5404SPeter Xu } 992a75b5404SPeter Xu 9933bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 9943bcd0662SPeter Xu { 9953bcd0662SPeter Xu struct pte_list_desc *desc; 9963bcd0662SPeter Xu unsigned int count = 0; 9973bcd0662SPeter Xu 9983bcd0662SPeter Xu if (!rmap_head->val) 9993bcd0662SPeter Xu return 0; 10003bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10013bcd0662SPeter Xu return 1; 10023bcd0662SPeter Xu 10033bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10043bcd0662SPeter Xu 10053bcd0662SPeter Xu while (desc) { 10063bcd0662SPeter Xu count += desc->spte_count; 10073bcd0662SPeter Xu desc = desc->more; 10083bcd0662SPeter Xu } 10093bcd0662SPeter Xu 10103bcd0662SPeter Xu return count; 10113bcd0662SPeter Xu } 10123bcd0662SPeter Xu 101393e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1014269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1015c50d8ae3SPaolo Bonzini { 1016c50d8ae3SPaolo Bonzini unsigned long idx; 1017c50d8ae3SPaolo Bonzini 1018c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10193bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1020c50d8ae3SPaolo Bonzini } 1021c50d8ae3SPaolo Bonzini 1022c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1023c50d8ae3SPaolo Bonzini { 1024356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1025c50d8ae3SPaolo Bonzini 1026356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 102794ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1028c50d8ae3SPaolo Bonzini } 1029c50d8ae3SPaolo Bonzini 1030c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1031c50d8ae3SPaolo Bonzini { 1032601f8af0SDavid Matlack struct kvm_memslots *slots; 1033601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1034c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1035c50d8ae3SPaolo Bonzini gfn_t gfn; 1036c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1037c50d8ae3SPaolo Bonzini 103857354682SSean Christopherson sp = sptep_to_sp(spte); 1039c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt); 1040601f8af0SDavid Matlack 1041601f8af0SDavid Matlack /* 104268be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 104368be1306SDavid Matlack * so we have to determine which memslots to use based on context 104468be1306SDavid Matlack * information in sp->role. 1045601f8af0SDavid Matlack */ 1046601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1047601f8af0SDavid Matlack 1048601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 104993e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1050601f8af0SDavid Matlack 1051c50d8ae3SPaolo Bonzini __pte_list_remove(spte, rmap_head); 1052c50d8ae3SPaolo Bonzini } 1053c50d8ae3SPaolo Bonzini 1054c50d8ae3SPaolo Bonzini /* 1055c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1056c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1057c50d8ae3SPaolo Bonzini */ 1058c50d8ae3SPaolo Bonzini struct rmap_iterator { 1059c50d8ae3SPaolo Bonzini /* private fields */ 1060c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1061c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1062c50d8ae3SPaolo Bonzini }; 1063c50d8ae3SPaolo Bonzini 1064c50d8ae3SPaolo Bonzini /* 1065c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1066c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10670a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1068c50d8ae3SPaolo Bonzini * 1069c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1070c50d8ae3SPaolo Bonzini */ 1071c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1072c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1073c50d8ae3SPaolo Bonzini { 1074c50d8ae3SPaolo Bonzini u64 *sptep; 1075c50d8ae3SPaolo Bonzini 1076c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1077c50d8ae3SPaolo Bonzini return NULL; 1078c50d8ae3SPaolo Bonzini 1079c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1080c50d8ae3SPaolo Bonzini iter->desc = NULL; 1081c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1082c50d8ae3SPaolo Bonzini goto out; 1083c50d8ae3SPaolo Bonzini } 1084c50d8ae3SPaolo Bonzini 1085c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1086c50d8ae3SPaolo Bonzini iter->pos = 0; 1087c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1088c50d8ae3SPaolo Bonzini out: 1089c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1090c50d8ae3SPaolo Bonzini return sptep; 1091c50d8ae3SPaolo Bonzini } 1092c50d8ae3SPaolo Bonzini 1093c50d8ae3SPaolo Bonzini /* 1094c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1095c50d8ae3SPaolo Bonzini * 1096c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1097c50d8ae3SPaolo Bonzini */ 1098c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1099c50d8ae3SPaolo Bonzini { 1100c50d8ae3SPaolo Bonzini u64 *sptep; 1101c50d8ae3SPaolo Bonzini 1102c50d8ae3SPaolo Bonzini if (iter->desc) { 1103c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1104c50d8ae3SPaolo Bonzini ++iter->pos; 1105c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1106c50d8ae3SPaolo Bonzini if (sptep) 1107c50d8ae3SPaolo Bonzini goto out; 1108c50d8ae3SPaolo Bonzini } 1109c50d8ae3SPaolo Bonzini 1110c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1111c50d8ae3SPaolo Bonzini 1112c50d8ae3SPaolo Bonzini if (iter->desc) { 1113c50d8ae3SPaolo Bonzini iter->pos = 0; 1114c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1115c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1116c50d8ae3SPaolo Bonzini goto out; 1117c50d8ae3SPaolo Bonzini } 1118c50d8ae3SPaolo Bonzini } 1119c50d8ae3SPaolo Bonzini 1120c50d8ae3SPaolo Bonzini return NULL; 1121c50d8ae3SPaolo Bonzini out: 1122c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1123c50d8ae3SPaolo Bonzini return sptep; 1124c50d8ae3SPaolo Bonzini } 1125c50d8ae3SPaolo Bonzini 1126c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1127c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1128c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1129c50d8ae3SPaolo Bonzini 1130c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1131c50d8ae3SPaolo Bonzini { 113271f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11337fa2a347SSean Christopherson 11347fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1135c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1136c50d8ae3SPaolo Bonzini } 1137c50d8ae3SPaolo Bonzini 1138c50d8ae3SPaolo Bonzini 1139c50d8ae3SPaolo Bonzini static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) 1140c50d8ae3SPaolo Bonzini { 1141c50d8ae3SPaolo Bonzini if (is_large_pte(*sptep)) { 114257354682SSean Christopherson WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); 1143c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 1144c50d8ae3SPaolo Bonzini return true; 1145c50d8ae3SPaolo Bonzini } 1146c50d8ae3SPaolo Bonzini 1147c50d8ae3SPaolo Bonzini return false; 1148c50d8ae3SPaolo Bonzini } 1149c50d8ae3SPaolo Bonzini 1150c50d8ae3SPaolo Bonzini static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) 1151c50d8ae3SPaolo Bonzini { 1152c50d8ae3SPaolo Bonzini if (__drop_large_spte(vcpu->kvm, sptep)) { 115357354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 1154c50d8ae3SPaolo Bonzini 1155c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, 1156c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1157c50d8ae3SPaolo Bonzini } 1158c50d8ae3SPaolo Bonzini } 1159c50d8ae3SPaolo Bonzini 1160c50d8ae3SPaolo Bonzini /* 1161c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1162c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1163c50d8ae3SPaolo Bonzini * 1164c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1165c50d8ae3SPaolo Bonzini * protection: 1166c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1167c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1168c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1169c50d8ae3SPaolo Bonzini * shadow page. 1170c50d8ae3SPaolo Bonzini * 1171c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1172c50d8ae3SPaolo Bonzini */ 1173c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1174c50d8ae3SPaolo Bonzini { 1175c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1176c50d8ae3SPaolo Bonzini 1177c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1178706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1179c50d8ae3SPaolo Bonzini return false; 1180c50d8ae3SPaolo Bonzini 1181805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1182c50d8ae3SPaolo Bonzini 1183c50d8ae3SPaolo Bonzini if (pt_protect) 11845fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1185c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1186c50d8ae3SPaolo Bonzini 1187c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1188c50d8ae3SPaolo Bonzini } 1189c50d8ae3SPaolo Bonzini 11901346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1191c50d8ae3SPaolo Bonzini bool pt_protect) 1192c50d8ae3SPaolo Bonzini { 1193c50d8ae3SPaolo Bonzini u64 *sptep; 1194c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1195c50d8ae3SPaolo Bonzini bool flush = false; 1196c50d8ae3SPaolo Bonzini 1197c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1198c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1199c50d8ae3SPaolo Bonzini 1200c50d8ae3SPaolo Bonzini return flush; 1201c50d8ae3SPaolo Bonzini } 1202c50d8ae3SPaolo Bonzini 1203c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1204c50d8ae3SPaolo Bonzini { 1205c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1206c50d8ae3SPaolo Bonzini 1207805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1208c50d8ae3SPaolo Bonzini 1209c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1210c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1211c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1212c50d8ae3SPaolo Bonzini } 1213c50d8ae3SPaolo Bonzini 1214c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1215c50d8ae3SPaolo Bonzini { 1216c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1217c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1218c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1219c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1220c50d8ae3SPaolo Bonzini 1221c50d8ae3SPaolo Bonzini return was_writable; 1222c50d8ae3SPaolo Bonzini } 1223c50d8ae3SPaolo Bonzini 1224c50d8ae3SPaolo Bonzini /* 1225c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1226c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1227c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1228c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1229c50d8ae3SPaolo Bonzini */ 12300a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1231269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1232c50d8ae3SPaolo Bonzini { 1233c50d8ae3SPaolo Bonzini u64 *sptep; 1234c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1235c50d8ae3SPaolo Bonzini bool flush = false; 1236c50d8ae3SPaolo Bonzini 1237c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1238c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1239c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1240c50d8ae3SPaolo Bonzini else 1241c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1242c50d8ae3SPaolo Bonzini 1243c50d8ae3SPaolo Bonzini return flush; 1244c50d8ae3SPaolo Bonzini } 1245c50d8ae3SPaolo Bonzini 1246c50d8ae3SPaolo Bonzini /** 1247c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1248c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1249c50d8ae3SPaolo Bonzini * @slot: slot to protect 1250c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1251c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1252c50d8ae3SPaolo Bonzini * 125389212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1254c50d8ae3SPaolo Bonzini */ 1255c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1256c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1257c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1258c50d8ae3SPaolo Bonzini { 1259c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1260c50d8ae3SPaolo Bonzini 1261897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1262a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1263a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1264e2209710SBen Gardon 1265e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1266e2209710SBen Gardon return; 1267e2209710SBen Gardon 1268c50d8ae3SPaolo Bonzini while (mask) { 126993e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12703bae0459SSean Christopherson PG_LEVEL_4K, slot); 12711346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1272c50d8ae3SPaolo Bonzini 1273c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1274c50d8ae3SPaolo Bonzini mask &= mask - 1; 1275c50d8ae3SPaolo Bonzini } 1276c50d8ae3SPaolo Bonzini } 1277c50d8ae3SPaolo Bonzini 1278c50d8ae3SPaolo Bonzini /** 1279c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1280c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1281c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1282c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1283c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1284c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1285c50d8ae3SPaolo Bonzini * 1286c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1287c50d8ae3SPaolo Bonzini */ 1288a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1289c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1290c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1291c50d8ae3SPaolo Bonzini { 1292c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1293c50d8ae3SPaolo Bonzini 1294897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1295a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1296a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1297e2209710SBen Gardon 1298e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1299e2209710SBen Gardon return; 1300e2209710SBen Gardon 1301c50d8ae3SPaolo Bonzini while (mask) { 130293e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13033bae0459SSean Christopherson PG_LEVEL_4K, slot); 13040a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1305c50d8ae3SPaolo Bonzini 1306c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1307c50d8ae3SPaolo Bonzini mask &= mask - 1; 1308c50d8ae3SPaolo Bonzini } 1309c50d8ae3SPaolo Bonzini } 1310c50d8ae3SPaolo Bonzini 1311c50d8ae3SPaolo Bonzini /** 1312c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1313c50d8ae3SPaolo Bonzini * PT level pages. 1314c50d8ae3SPaolo Bonzini * 1315c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1316c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1317c50d8ae3SPaolo Bonzini * 131889212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 131989212919SKeqian Zhu * have such mappings. 1320c50d8ae3SPaolo Bonzini */ 1321c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1322c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1323c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1324c50d8ae3SPaolo Bonzini { 132589212919SKeqian Zhu /* 132689212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 132789212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 132889212919SKeqian Zhu * are split to 4K on the first write. 132989212919SKeqian Zhu * 133089212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 133189212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 133289212919SKeqian Zhu * pages. 133389212919SKeqian Zhu */ 133489212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 133589212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 133689212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 133789212919SKeqian Zhu 1338cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1339cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1340cb00a70bSDavid Matlack 134189212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 134289212919SKeqian Zhu 134389212919SKeqian Zhu /* Cross two large pages? */ 134489212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 134589212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 134689212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 134789212919SKeqian Zhu PG_LEVEL_2M); 134889212919SKeqian Zhu } 134989212919SKeqian Zhu 135089212919SKeqian Zhu /* Now handle 4K PTEs. */ 1351a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1352a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1353c50d8ae3SPaolo Bonzini else 1354c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1355c50d8ae3SPaolo Bonzini } 1356c50d8ae3SPaolo Bonzini 1357fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1358fb04a1edSPeter Xu { 13596dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1360fb04a1edSPeter Xu } 1361fb04a1edSPeter Xu 1362c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13633ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13643ad93562SKeqian Zhu int min_level) 1365c50d8ae3SPaolo Bonzini { 1366c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1367c50d8ae3SPaolo Bonzini int i; 1368c50d8ae3SPaolo Bonzini bool write_protected = false; 1369c50d8ae3SPaolo Bonzini 1370e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13713ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 137293e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13731346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1374c50d8ae3SPaolo Bonzini } 1375e2209710SBen Gardon } 1376c50d8ae3SPaolo Bonzini 1377897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 137846044f72SBen Gardon write_protected |= 13793ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 138046044f72SBen Gardon 1381c50d8ae3SPaolo Bonzini return write_protected; 1382c50d8ae3SPaolo Bonzini } 1383c50d8ae3SPaolo Bonzini 1384cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1385c50d8ae3SPaolo Bonzini { 1386c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1387c50d8ae3SPaolo Bonzini 1388c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 13893ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1390c50d8ae3SPaolo Bonzini } 1391c50d8ae3SPaolo Bonzini 13920a234f5dSSean Christopherson static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1393269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1394c50d8ae3SPaolo Bonzini { 139571f51d2cSMingwei Zhang return pte_list_destroy(kvm, rmap_head); 1396c50d8ae3SPaolo Bonzini } 1397c50d8ae3SPaolo Bonzini 13983039bcc7SSean Christopherson static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1399c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14003039bcc7SSean Christopherson pte_t unused) 1401c50d8ae3SPaolo Bonzini { 14020a234f5dSSean Christopherson return kvm_zap_rmapp(kvm, rmap_head, slot); 1403c50d8ae3SPaolo Bonzini } 1404c50d8ae3SPaolo Bonzini 14053039bcc7SSean Christopherson static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1406c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14073039bcc7SSean Christopherson pte_t pte) 1408c50d8ae3SPaolo Bonzini { 1409c50d8ae3SPaolo Bonzini u64 *sptep; 1410c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 141198a26b69SVihas Mak bool need_flush = false; 1412c50d8ae3SPaolo Bonzini u64 new_spte; 1413c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1414c50d8ae3SPaolo Bonzini 14153039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14163039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1417c50d8ae3SPaolo Bonzini 1418c50d8ae3SPaolo Bonzini restart: 1419c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1420805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1421c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1422c50d8ae3SPaolo Bonzini 142398a26b69SVihas Mak need_flush = true; 1424c50d8ae3SPaolo Bonzini 14253039bcc7SSean Christopherson if (pte_write(pte)) { 142671f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 1427c50d8ae3SPaolo Bonzini goto restart; 1428c50d8ae3SPaolo Bonzini } else { 1429cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1430cb3eedabSPaolo Bonzini *sptep, new_pfn); 1431c50d8ae3SPaolo Bonzini 143271f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1433c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1434c50d8ae3SPaolo Bonzini } 1435c50d8ae3SPaolo Bonzini } 1436c50d8ae3SPaolo Bonzini 1437c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1438c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 143998a26b69SVihas Mak return false; 1440c50d8ae3SPaolo Bonzini } 1441c50d8ae3SPaolo Bonzini 1442c50d8ae3SPaolo Bonzini return need_flush; 1443c50d8ae3SPaolo Bonzini } 1444c50d8ae3SPaolo Bonzini 1445c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1446c50d8ae3SPaolo Bonzini /* input fields. */ 1447269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1448c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1449c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1450c50d8ae3SPaolo Bonzini int start_level; 1451c50d8ae3SPaolo Bonzini int end_level; 1452c50d8ae3SPaolo Bonzini 1453c50d8ae3SPaolo Bonzini /* output fields. */ 1454c50d8ae3SPaolo Bonzini gfn_t gfn; 1455c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1456c50d8ae3SPaolo Bonzini int level; 1457c50d8ae3SPaolo Bonzini 1458c50d8ae3SPaolo Bonzini /* private field. */ 1459c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1460c50d8ae3SPaolo Bonzini }; 1461c50d8ae3SPaolo Bonzini 1462c50d8ae3SPaolo Bonzini static void 1463c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1464c50d8ae3SPaolo Bonzini { 1465c50d8ae3SPaolo Bonzini iterator->level = level; 1466c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 146793e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 146893e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1469c50d8ae3SPaolo Bonzini } 1470c50d8ae3SPaolo Bonzini 1471c50d8ae3SPaolo Bonzini static void 1472c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1473269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1474c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1475c50d8ae3SPaolo Bonzini { 1476c50d8ae3SPaolo Bonzini iterator->slot = slot; 1477c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1478c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1479c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1480c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1481c50d8ae3SPaolo Bonzini 1482c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1483c50d8ae3SPaolo Bonzini } 1484c50d8ae3SPaolo Bonzini 1485c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1486c50d8ae3SPaolo Bonzini { 1487c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1488c50d8ae3SPaolo Bonzini } 1489c50d8ae3SPaolo Bonzini 1490c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1491c50d8ae3SPaolo Bonzini { 14926ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1493c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 14946ba1e04fSVipin Sharma 14956ba1e04fSVipin Sharma if (iterator->rmap->val) 1496c50d8ae3SPaolo Bonzini return; 1497c50d8ae3SPaolo Bonzini } 1498c50d8ae3SPaolo Bonzini 1499c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1500c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1501c50d8ae3SPaolo Bonzini return; 1502c50d8ae3SPaolo Bonzini } 1503c50d8ae3SPaolo Bonzini 1504c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1505c50d8ae3SPaolo Bonzini } 1506c50d8ae3SPaolo Bonzini 1507c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1508c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1509c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1510c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1511c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1512c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1513c50d8ae3SPaolo Bonzini 15143039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1515c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15163039bcc7SSean Christopherson int level, pte_t pte); 1517c1b91493SSean Christopherson 15183039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15193039bcc7SSean Christopherson struct kvm_gfn_range *range, 1520c1b91493SSean Christopherson rmap_handler_t handler) 1521c50d8ae3SPaolo Bonzini { 1522c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15233039bcc7SSean Christopherson bool ret = false; 1524c50d8ae3SPaolo Bonzini 15253039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15263039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15273039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15283039bcc7SSean Christopherson iterator.level, range->pte); 1529c50d8ae3SPaolo Bonzini 1530c50d8ae3SPaolo Bonzini return ret; 1531c50d8ae3SPaolo Bonzini } 1532c50d8ae3SPaolo Bonzini 15333039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1534c50d8ae3SPaolo Bonzini { 1535e2209710SBen Gardon bool flush = false; 1536c50d8ae3SPaolo Bonzini 1537e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15383039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp); 1539063afacdSBen Gardon 1540897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1541c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1542063afacdSBen Gardon 15433039bcc7SSean Christopherson return flush; 1544c50d8ae3SPaolo Bonzini } 1545c50d8ae3SPaolo Bonzini 15463039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1547c50d8ae3SPaolo Bonzini { 1548e2209710SBen Gardon bool flush = false; 15491d8dd6b3SBen Gardon 1550e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15513039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp); 15521d8dd6b3SBen Gardon 1553897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15543039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15551d8dd6b3SBen Gardon 15563039bcc7SSean Christopherson return flush; 1557c50d8ae3SPaolo Bonzini } 1558c50d8ae3SPaolo Bonzini 15593039bcc7SSean Christopherson static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1560c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15613039bcc7SSean Christopherson pte_t unused) 1562c50d8ae3SPaolo Bonzini { 1563c50d8ae3SPaolo Bonzini u64 *sptep; 15643f649ab7SKees Cook struct rmap_iterator iter; 1565c50d8ae3SPaolo Bonzini int young = 0; 1566c50d8ae3SPaolo Bonzini 1567c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1568c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1569c50d8ae3SPaolo Bonzini 1570c50d8ae3SPaolo Bonzini return young; 1571c50d8ae3SPaolo Bonzini } 1572c50d8ae3SPaolo Bonzini 15733039bcc7SSean Christopherson static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1574c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15753039bcc7SSean Christopherson int level, pte_t unused) 1576c50d8ae3SPaolo Bonzini { 1577c50d8ae3SPaolo Bonzini u64 *sptep; 1578c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1579c50d8ae3SPaolo Bonzini 1580c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1581c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 158298a26b69SVihas Mak return true; 158398a26b69SVihas Mak return false; 1584c50d8ae3SPaolo Bonzini } 1585c50d8ae3SPaolo Bonzini 1586c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1587c50d8ae3SPaolo Bonzini 15882ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 15892ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 15902ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 1591*6a97575dSDavid Matlack u64 *spte, gfn_t gfn, u32 access) 1592c50d8ae3SPaolo Bonzini { 1593c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 159468be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 159568be1306SDavid Matlack int rmap_count; 1596c50d8ae3SPaolo Bonzini 159757354682SSean Christopherson sp = sptep_to_sp(spte); 1598*6a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, spte - sp->spt, gfn, access); 159981cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 160081cb4657SDavid Matlack 160193e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 16022ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1603c50d8ae3SPaolo Bonzini 160468be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16052ff9039aSDavid Matlack kvm_unmap_rmapp(kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0)); 160668be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 16072ff9039aSDavid Matlack kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 160868be1306SDavid Matlack } 1609c50d8ae3SPaolo Bonzini } 1610c50d8ae3SPaolo Bonzini 16112ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 1612*6a97575dSDavid Matlack u64 *spte, gfn_t gfn, u32 access) 16132ff9039aSDavid Matlack { 16142ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16152ff9039aSDavid Matlack 1616*6a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16172ff9039aSDavid Matlack } 16182ff9039aSDavid Matlack 16193039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1620c50d8ae3SPaolo Bonzini { 1621e2209710SBen Gardon bool young = false; 1622f8e14497SBen Gardon 1623e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16243039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp); 16253039bcc7SSean Christopherson 1626897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16273039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1628f8e14497SBen Gardon 1629f8e14497SBen Gardon return young; 1630c50d8ae3SPaolo Bonzini } 1631c50d8ae3SPaolo Bonzini 16323039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1633c50d8ae3SPaolo Bonzini { 1634e2209710SBen Gardon bool young = false; 1635f8e14497SBen Gardon 1636e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 16373039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp); 16383039bcc7SSean Christopherson 1639897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16403039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1641f8e14497SBen Gardon 1642f8e14497SBen Gardon return young; 1643c50d8ae3SPaolo Bonzini } 1644c50d8ae3SPaolo Bonzini 1645c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1646c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1647c50d8ae3SPaolo Bonzini { 1648c50d8ae3SPaolo Bonzini u64 *pos; 1649c50d8ae3SPaolo Bonzini u64 *end; 1650c50d8ae3SPaolo Bonzini 1651c50d8ae3SPaolo Bonzini for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) 1652c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1653c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1654c50d8ae3SPaolo Bonzini pos, *pos); 1655c50d8ae3SPaolo Bonzini return 0; 1656c50d8ae3SPaolo Bonzini } 1657c50d8ae3SPaolo Bonzini return 1; 1658c50d8ae3SPaolo Bonzini } 1659c50d8ae3SPaolo Bonzini #endif 1660c50d8ae3SPaolo Bonzini 1661c50d8ae3SPaolo Bonzini /* 1662c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1663c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1664c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1665c50d8ae3SPaolo Bonzini * faster 1666c50d8ae3SPaolo Bonzini */ 1667d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1668c50d8ae3SPaolo Bonzini { 1669c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1670c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1671c50d8ae3SPaolo Bonzini } 1672c50d8ae3SPaolo Bonzini 167387654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1674c50d8ae3SPaolo Bonzini { 1675c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1676c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1677c50d8ae3SPaolo Bonzini list_del(&sp->link); 1678c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1679c50d8ae3SPaolo Bonzini if (!sp->role.direct) 1680*6a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1681c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1682c50d8ae3SPaolo Bonzini } 1683c50d8ae3SPaolo Bonzini 1684c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1685c50d8ae3SPaolo Bonzini { 1686c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1687c50d8ae3SPaolo Bonzini } 1688c50d8ae3SPaolo Bonzini 16892ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1690c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1691c50d8ae3SPaolo Bonzini { 1692c50d8ae3SPaolo Bonzini if (!parent_pte) 1693c50d8ae3SPaolo Bonzini return; 1694c50d8ae3SPaolo Bonzini 16952ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1696c50d8ae3SPaolo Bonzini } 1697c50d8ae3SPaolo Bonzini 1698c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1699c50d8ae3SPaolo Bonzini u64 *parent_pte) 1700c50d8ae3SPaolo Bonzini { 1701c50d8ae3SPaolo Bonzini __pte_list_remove(parent_pte, &sp->parent_ptes); 1702c50d8ae3SPaolo Bonzini } 1703c50d8ae3SPaolo Bonzini 1704c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1705c50d8ae3SPaolo Bonzini u64 *parent_pte) 1706c50d8ae3SPaolo Bonzini { 1707c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1708c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1709c50d8ae3SPaolo Bonzini } 1710c50d8ae3SPaolo Bonzini 1711c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1712c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1713c50d8ae3SPaolo Bonzini { 1714c50d8ae3SPaolo Bonzini u64 *sptep; 1715c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1716c50d8ae3SPaolo Bonzini 1717c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1718c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1719c50d8ae3SPaolo Bonzini } 1720c50d8ae3SPaolo Bonzini } 1721c50d8ae3SPaolo Bonzini 1722c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1723c50d8ae3SPaolo Bonzini { 1724c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1725c50d8ae3SPaolo Bonzini unsigned int index; 1726c50d8ae3SPaolo Bonzini 172757354682SSean Christopherson sp = sptep_to_sp(spte); 1728c50d8ae3SPaolo Bonzini index = spte - sp->spt; 1729c50d8ae3SPaolo Bonzini if (__test_and_set_bit(index, sp->unsync_child_bitmap)) 1730c50d8ae3SPaolo Bonzini return; 1731c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1732c50d8ae3SPaolo Bonzini return; 1733c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1734c50d8ae3SPaolo Bonzini } 1735c50d8ae3SPaolo Bonzini 1736c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1737c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1738c50d8ae3SPaolo Bonzini { 1739c3e5e415SLai Jiangshan return -1; 1740c50d8ae3SPaolo Bonzini } 1741c50d8ae3SPaolo Bonzini 1742c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1743c50d8ae3SPaolo Bonzini 1744c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1745c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1746c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1747c50d8ae3SPaolo Bonzini unsigned int idx; 1748c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1749c50d8ae3SPaolo Bonzini unsigned int nr; 1750c50d8ae3SPaolo Bonzini }; 1751c50d8ae3SPaolo Bonzini 1752c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1753c50d8ae3SPaolo Bonzini int idx) 1754c50d8ae3SPaolo Bonzini { 1755c50d8ae3SPaolo Bonzini int i; 1756c50d8ae3SPaolo Bonzini 1757c50d8ae3SPaolo Bonzini if (sp->unsync) 1758c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1759c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1760c50d8ae3SPaolo Bonzini return 0; 1761c50d8ae3SPaolo Bonzini 1762c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1763c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1764c50d8ae3SPaolo Bonzini pvec->nr++; 1765c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1766c50d8ae3SPaolo Bonzini } 1767c50d8ae3SPaolo Bonzini 1768c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1769c50d8ae3SPaolo Bonzini { 1770c50d8ae3SPaolo Bonzini --sp->unsync_children; 1771c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1772c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1773c50d8ae3SPaolo Bonzini } 1774c50d8ae3SPaolo Bonzini 1775c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1776c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1777c50d8ae3SPaolo Bonzini { 1778c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1779c50d8ae3SPaolo Bonzini 1780c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1781c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1782c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1783c50d8ae3SPaolo Bonzini 1784c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1785c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1786c50d8ae3SPaolo Bonzini continue; 1787c50d8ae3SPaolo Bonzini } 1788c50d8ae3SPaolo Bonzini 17892ca3129eSSean Christopherson child = to_shadow_page(ent & SPTE_BASE_ADDR_MASK); 1790c50d8ae3SPaolo Bonzini 1791c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1792c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1793c50d8ae3SPaolo Bonzini return -ENOSPC; 1794c50d8ae3SPaolo Bonzini 1795c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1796c50d8ae3SPaolo Bonzini if (!ret) { 1797c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1798c50d8ae3SPaolo Bonzini continue; 1799c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1800c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1801c50d8ae3SPaolo Bonzini } else 1802c50d8ae3SPaolo Bonzini return ret; 1803c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1804c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1805c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1806c50d8ae3SPaolo Bonzini return -ENOSPC; 1807c50d8ae3SPaolo Bonzini } else 1808c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1809c50d8ae3SPaolo Bonzini } 1810c50d8ae3SPaolo Bonzini 1811c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1812c50d8ae3SPaolo Bonzini } 1813c50d8ae3SPaolo Bonzini 1814c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1815c50d8ae3SPaolo Bonzini 1816c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1817c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1818c50d8ae3SPaolo Bonzini { 1819c50d8ae3SPaolo Bonzini pvec->nr = 0; 1820c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1821c50d8ae3SPaolo Bonzini return 0; 1822c50d8ae3SPaolo Bonzini 1823c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1824c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1825c50d8ae3SPaolo Bonzini } 1826c50d8ae3SPaolo Bonzini 1827c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1828c50d8ae3SPaolo Bonzini { 1829c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1830c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1831c50d8ae3SPaolo Bonzini sp->unsync = 0; 1832c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1833c50d8ae3SPaolo Bonzini } 1834c50d8ae3SPaolo Bonzini 1835c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1836c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1837c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1838c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1839c50d8ae3SPaolo Bonzini 1840767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1841767d8d8dSLai Jiangshan { 1842767d8d8dSLai Jiangshan if (sp->role.direct) 1843767d8d8dSLai Jiangshan return false; 1844767d8d8dSLai Jiangshan 184584e5ffd0SLai Jiangshan if (sp->role.passthrough) 184684e5ffd0SLai Jiangshan return false; 184784e5ffd0SLai Jiangshan 1848767d8d8dSLai Jiangshan return true; 1849767d8d8dSLai Jiangshan } 1850767d8d8dSLai Jiangshan 1851ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1852ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1853c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1854c50d8ae3SPaolo Bonzini } else 1855c50d8ae3SPaolo Bonzini 1856767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1857ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1858ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1859767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1860c50d8ae3SPaolo Bonzini 18618d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1862c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1863c50d8ae3SPaolo Bonzini { 1864c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1865c3e5e415SLai Jiangshan 18668d5678a7SHou Wenlong if (ret < 0) 1867c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18688d5678a7SHou Wenlong return ret; 1869c50d8ae3SPaolo Bonzini } 1870c50d8ae3SPaolo Bonzini 1871c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1872c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1873c50d8ae3SPaolo Bonzini bool remote_flush) 1874c50d8ae3SPaolo Bonzini { 1875c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1876c50d8ae3SPaolo Bonzini return false; 1877c50d8ae3SPaolo Bonzini 1878c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1879c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1880c50d8ae3SPaolo Bonzini else 1881c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1882c50d8ae3SPaolo Bonzini return true; 1883c50d8ae3SPaolo Bonzini } 1884c50d8ae3SPaolo Bonzini 1885c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1886c50d8ae3SPaolo Bonzini { 1887a955cad8SSean Christopherson if (sp->role.invalid) 1888a955cad8SSean Christopherson return true; 1889a955cad8SSean Christopherson 1890a955cad8SSean Christopherson /* TDP MMU pages due not use the MMU generation. */ 1891a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1892c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1893c50d8ae3SPaolo Bonzini } 1894c50d8ae3SPaolo Bonzini 1895c50d8ae3SPaolo Bonzini struct mmu_page_path { 1896c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1897c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1898c50d8ae3SPaolo Bonzini }; 1899c50d8ae3SPaolo Bonzini 1900c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1901c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1902c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1903c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1904c50d8ae3SPaolo Bonzini 1905c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1906c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1907c50d8ae3SPaolo Bonzini int i) 1908c50d8ae3SPaolo Bonzini { 1909c50d8ae3SPaolo Bonzini int n; 1910c50d8ae3SPaolo Bonzini 1911c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1912c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1913c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1914c50d8ae3SPaolo Bonzini int level = sp->role.level; 1915c50d8ae3SPaolo Bonzini 1916c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19173bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1918c50d8ae3SPaolo Bonzini break; 1919c50d8ae3SPaolo Bonzini 1920c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1921c50d8ae3SPaolo Bonzini } 1922c50d8ae3SPaolo Bonzini 1923c50d8ae3SPaolo Bonzini return n; 1924c50d8ae3SPaolo Bonzini } 1925c50d8ae3SPaolo Bonzini 1926c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1927c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1928c50d8ae3SPaolo Bonzini { 1929c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1930c50d8ae3SPaolo Bonzini int level; 1931c50d8ae3SPaolo Bonzini 1932c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1933c50d8ae3SPaolo Bonzini return 0; 1934c50d8ae3SPaolo Bonzini 1935c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1936c50d8ae3SPaolo Bonzini 1937c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1938c50d8ae3SPaolo Bonzini level = sp->role.level; 19393bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1940c50d8ae3SPaolo Bonzini 1941c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1942c50d8ae3SPaolo Bonzini 1943c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1944c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1945c50d8ae3SPaolo Bonzini */ 1946c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1947c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1948c50d8ae3SPaolo Bonzini } 1949c50d8ae3SPaolo Bonzini 1950c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1951c50d8ae3SPaolo Bonzini { 1952c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1953c50d8ae3SPaolo Bonzini unsigned int level = 0; 1954c50d8ae3SPaolo Bonzini 1955c50d8ae3SPaolo Bonzini do { 1956c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1957c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1958c50d8ae3SPaolo Bonzini if (!sp) 1959c50d8ae3SPaolo Bonzini return; 1960c50d8ae3SPaolo Bonzini 1961c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1962c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1963c50d8ae3SPaolo Bonzini level++; 1964c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1965c50d8ae3SPaolo Bonzini } 1966c50d8ae3SPaolo Bonzini 196765855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 196865855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1969c50d8ae3SPaolo Bonzini { 1970c50d8ae3SPaolo Bonzini int i; 1971c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1972c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1973c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1974c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1975c50d8ae3SPaolo Bonzini bool flush = false; 1976c50d8ae3SPaolo Bonzini 1977c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 1978c50d8ae3SPaolo Bonzini bool protected = false; 1979c50d8ae3SPaolo Bonzini 1980c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 1981cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 1982c50d8ae3SPaolo Bonzini 1983c50d8ae3SPaolo Bonzini if (protected) { 19845591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 1985c50d8ae3SPaolo Bonzini flush = false; 1986c50d8ae3SPaolo Bonzini } 1987c50d8ae3SPaolo Bonzini 1988c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 1989479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 19908d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 1991c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 1992c50d8ae3SPaolo Bonzini } 1993531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 1994c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 199565855ed8SLai Jiangshan if (!can_yield) { 199665855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 199765855ed8SLai Jiangshan return -EINTR; 199865855ed8SLai Jiangshan } 199965855ed8SLai Jiangshan 2000531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2001c50d8ae3SPaolo Bonzini flush = false; 2002c50d8ae3SPaolo Bonzini } 2003c50d8ae3SPaolo Bonzini } 2004c50d8ae3SPaolo Bonzini 2005c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 200665855ed8SLai Jiangshan return 0; 2007c50d8ae3SPaolo Bonzini } 2008c50d8ae3SPaolo Bonzini 2009c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2010c50d8ae3SPaolo Bonzini { 2011c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2012c50d8ae3SPaolo Bonzini } 2013c50d8ae3SPaolo Bonzini 2014c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2015c50d8ae3SPaolo Bonzini { 201657354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2017c50d8ae3SPaolo Bonzini } 2018c50d8ae3SPaolo Bonzini 2019cbd858b1SDavid Matlack /* 2020cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2021cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2022cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2023cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2024cbd858b1SDavid Matlack */ 20253cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 20263cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 202794c81364SDavid Matlack gfn_t gfn, 202894c81364SDavid Matlack struct hlist_head *sp_list, 20292e65e842SDavid Matlack union kvm_mmu_page_role role) 2030c50d8ae3SPaolo Bonzini { 2031c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20328d5678a7SHou Wenlong int ret; 2033c50d8ae3SPaolo Bonzini int collisions = 0; 2034c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2035c50d8ae3SPaolo Bonzini 20363cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2037c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2038c50d8ae3SPaolo Bonzini collisions++; 2039c50d8ae3SPaolo Bonzini continue; 2040c50d8ae3SPaolo Bonzini } 2041c50d8ae3SPaolo Bonzini 2042ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2043ddc16abbSSean Christopherson /* 2044ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2045ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2046ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2047ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2048ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2049ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2050ddc16abbSSean Christopherson * upper-level page will be write-protected. 2051ddc16abbSSean Christopherson */ 20522e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 20533cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2054ddc16abbSSean Christopherson &invalid_list); 2055c50d8ae3SPaolo Bonzini continue; 2056ddc16abbSSean Christopherson } 2057c50d8ae3SPaolo Bonzini 2058bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2059bb924ca6SDavid Matlack if (sp->role.direct) 206094c81364SDavid Matlack goto out; 2061fb58a9c3SSean Christopherson 2062c50d8ae3SPaolo Bonzini if (sp->unsync) { 2063cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2064cbd858b1SDavid Matlack break; 2065cbd858b1SDavid Matlack 206607dc4f35SSean Christopherson /* 2067479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 206807dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 206907dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 207007dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 207107dc4f35SSean Christopherson * overhead of write protection is not incurred until the 207207dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 207307dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 207407dc4f35SSean Christopherson * 207507dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 207607dc4f35SSean Christopherson * in order to rebuild it. 2077c50d8ae3SPaolo Bonzini */ 20788d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 20798d5678a7SHou Wenlong if (ret < 0) 2080c50d8ae3SPaolo Bonzini break; 2081c50d8ae3SPaolo Bonzini 2082c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 20838d5678a7SHou Wenlong if (ret > 0) 20843cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2085c50d8ae3SPaolo Bonzini } 2086c50d8ae3SPaolo Bonzini 2087c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2088fb58a9c3SSean Christopherson 2089c50d8ae3SPaolo Bonzini goto out; 2090c50d8ae3SPaolo Bonzini } 2091c50d8ae3SPaolo Bonzini 209294c81364SDavid Matlack sp = NULL; 20933cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2094c50d8ae3SPaolo Bonzini 209594c81364SDavid Matlack out: 20963cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 209794c81364SDavid Matlack 20983cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 20993cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 210094c81364SDavid Matlack return sp; 210194c81364SDavid Matlack } 210294c81364SDavid Matlack 21032f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 21042f8b1b53SDavid Matlack struct shadow_page_caches { 21052f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 21062f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 2107*6a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 21082f8b1b53SDavid Matlack }; 21092f8b1b53SDavid Matlack 2110336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 21112f8b1b53SDavid Matlack struct shadow_page_caches *caches, 211294c81364SDavid Matlack gfn_t gfn, 211394c81364SDavid Matlack struct hlist_head *sp_list, 211494c81364SDavid Matlack union kvm_mmu_page_role role) 211594c81364SDavid Matlack { 2116c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2117c306aec8SDavid Matlack 21182f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 21192f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2120c306aec8SDavid Matlack if (!role.direct) 2121*6a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2122c306aec8SDavid Matlack 2123c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2124c306aec8SDavid Matlack 2125c306aec8SDavid Matlack /* 2126c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2127c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2128c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2129c306aec8SDavid Matlack */ 2130336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2131336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 2132336081fbSDavid Matlack kvm_mod_used_mmu_pages(kvm, +1); 2133c50d8ae3SPaolo Bonzini 2134c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2135c50d8ae3SPaolo Bonzini sp->role = role; 2136ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2137be911771SDavid Matlack if (sp_has_gptes(sp)) 2138336081fbSDavid Matlack account_shadowed(kvm, sp); 2139ddc16abbSSean Christopherson 214094c81364SDavid Matlack return sp; 214194c81364SDavid Matlack } 214294c81364SDavid Matlack 2143cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 21443cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 21453cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 21462f8b1b53SDavid Matlack struct shadow_page_caches *caches, 214787654643SDavid Matlack gfn_t gfn, 214894c81364SDavid Matlack union kvm_mmu_page_role role) 214994c81364SDavid Matlack { 215094c81364SDavid Matlack struct hlist_head *sp_list; 215194c81364SDavid Matlack struct kvm_mmu_page *sp; 215294c81364SDavid Matlack bool created = false; 215394c81364SDavid Matlack 21543cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 215594c81364SDavid Matlack 21563cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 215794c81364SDavid Matlack if (!sp) { 215894c81364SDavid Matlack created = true; 21593cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 216094c81364SDavid Matlack } 216194c81364SDavid Matlack 216294c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2163c50d8ae3SPaolo Bonzini return sp; 2164c50d8ae3SPaolo Bonzini } 2165c50d8ae3SPaolo Bonzini 21662f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 21672f8b1b53SDavid Matlack gfn_t gfn, 21682f8b1b53SDavid Matlack union kvm_mmu_page_role role) 21692f8b1b53SDavid Matlack { 21702f8b1b53SDavid Matlack struct shadow_page_caches caches = { 21712f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 21722f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 2173*6a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 21742f8b1b53SDavid Matlack }; 21752f8b1b53SDavid Matlack 21763cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 21772f8b1b53SDavid Matlack } 21782f8b1b53SDavid Matlack 21792e65e842SDavid Matlack static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, unsigned int access) 21802e65e842SDavid Matlack { 21812e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 21822e65e842SDavid Matlack union kvm_mmu_page_role role; 21832e65e842SDavid Matlack 21842e65e842SDavid Matlack role = parent_sp->role; 21852e65e842SDavid Matlack role.level--; 21862e65e842SDavid Matlack role.access = access; 21872e65e842SDavid Matlack role.direct = direct; 21882e65e842SDavid Matlack role.passthrough = 0; 21892e65e842SDavid Matlack 21902e65e842SDavid Matlack /* 21912e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 21922e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 21932e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 21942e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 21952e65e842SDavid Matlack * requires extra bookkeeping in the role. 21962e65e842SDavid Matlack * 21972e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 21982e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 21992e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 22002e65e842SDavid Matlack * the address space each maps. 22012e65e842SDavid Matlack * 22022e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 22032e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 22042e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 22052e65e842SDavid Matlack * 22062e65e842SDavid Matlack * Note, the 4 PAE page directories are pre-allocated and the quadrant 22072e65e842SDavid Matlack * assigned in mmu_alloc_root(). So only page tables need to be handled 22082e65e842SDavid Matlack * here. 22092e65e842SDavid Matlack */ 22102e65e842SDavid Matlack if (role.has_4_byte_gpte) { 22112e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 22122e65e842SDavid Matlack role.quadrant = (sptep - parent_sp->spt) % 2; 22132e65e842SDavid Matlack } 22142e65e842SDavid Matlack 22152e65e842SDavid Matlack return role; 22162e65e842SDavid Matlack } 22172e65e842SDavid Matlack 22182e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 22192e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 22202e65e842SDavid Matlack bool direct, unsigned int access) 22212e65e842SDavid Matlack { 22222e65e842SDavid Matlack union kvm_mmu_page_role role; 22232e65e842SDavid Matlack 22242e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 222587654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 22262e65e842SDavid Matlack } 22272e65e842SDavid Matlack 2228c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2229c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2230c50d8ae3SPaolo Bonzini u64 addr) 2231c50d8ae3SPaolo Bonzini { 2232c50d8ae3SPaolo Bonzini iterator->addr = addr; 2233c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2234a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2235c50d8ae3SPaolo Bonzini 223612ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 22374d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2238347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 223912ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2240c50d8ae3SPaolo Bonzini 2241c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2242c50d8ae3SPaolo Bonzini /* 2243c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2244c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2245c50d8ae3SPaolo Bonzini */ 2246b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2247c50d8ae3SPaolo Bonzini 2248c50d8ae3SPaolo Bonzini iterator->shadow_addr 2249c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 22502ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2251c50d8ae3SPaolo Bonzini --iterator->level; 2252c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2253c50d8ae3SPaolo Bonzini iterator->level = 0; 2254c50d8ae3SPaolo Bonzini } 2255c50d8ae3SPaolo Bonzini } 2256c50d8ae3SPaolo Bonzini 2257c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2258c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2259c50d8ae3SPaolo Bonzini { 2260b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2261c50d8ae3SPaolo Bonzini addr); 2262c50d8ae3SPaolo Bonzini } 2263c50d8ae3SPaolo Bonzini 2264c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2265c50d8ae3SPaolo Bonzini { 22663bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2267c50d8ae3SPaolo Bonzini return false; 2268c50d8ae3SPaolo Bonzini 22692ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2270c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2271c50d8ae3SPaolo Bonzini return true; 2272c50d8ae3SPaolo Bonzini } 2273c50d8ae3SPaolo Bonzini 2274c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2275c50d8ae3SPaolo Bonzini u64 spte) 2276c50d8ae3SPaolo Bonzini { 22773e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2278c50d8ae3SPaolo Bonzini iterator->level = 0; 2279c50d8ae3SPaolo Bonzini return; 2280c50d8ae3SPaolo Bonzini } 2281c50d8ae3SPaolo Bonzini 22822ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2283c50d8ae3SPaolo Bonzini --iterator->level; 2284c50d8ae3SPaolo Bonzini } 2285c50d8ae3SPaolo Bonzini 2286c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2287c50d8ae3SPaolo Bonzini { 2288c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2289c50d8ae3SPaolo Bonzini } 2290c50d8ae3SPaolo Bonzini 22912ff9039aSDavid Matlack static void __link_shadow_page(struct kvm_mmu_memory_cache *cache, u64 *sptep, 2292c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 2293c50d8ae3SPaolo Bonzini { 2294c50d8ae3SPaolo Bonzini u64 spte; 2295c50d8ae3SPaolo Bonzini 2296c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2297c50d8ae3SPaolo Bonzini 2298cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2299c50d8ae3SPaolo Bonzini 2300c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2301c50d8ae3SPaolo Bonzini 23022ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2303c50d8ae3SPaolo Bonzini 2304c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2305c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2306c50d8ae3SPaolo Bonzini } 2307c50d8ae3SPaolo Bonzini 23082ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 23092ff9039aSDavid Matlack struct kvm_mmu_page *sp) 23102ff9039aSDavid Matlack { 23112ff9039aSDavid Matlack __link_shadow_page(&vcpu->arch.mmu_pte_list_desc_cache, sptep, sp); 23122ff9039aSDavid Matlack } 23132ff9039aSDavid Matlack 2314c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2315c50d8ae3SPaolo Bonzini unsigned direct_access) 2316c50d8ae3SPaolo Bonzini { 2317c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2318c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2319c50d8ae3SPaolo Bonzini 2320c50d8ae3SPaolo Bonzini /* 2321c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2322c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2323c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2324c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2325c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2326c50d8ae3SPaolo Bonzini */ 23272ca3129eSSean Christopherson child = to_shadow_page(*sptep & SPTE_BASE_ADDR_MASK); 2328c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2329c50d8ae3SPaolo Bonzini return; 2330c50d8ae3SPaolo Bonzini 2331c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2332c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2333c50d8ae3SPaolo Bonzini } 2334c50d8ae3SPaolo Bonzini } 2335c50d8ae3SPaolo Bonzini 23362de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 23372de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 23382de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2339c50d8ae3SPaolo Bonzini { 2340c50d8ae3SPaolo Bonzini u64 pte; 2341c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2342c50d8ae3SPaolo Bonzini 2343c50d8ae3SPaolo Bonzini pte = *spte; 2344c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2345c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2346c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2347c50d8ae3SPaolo Bonzini } else { 23482ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2349c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 23502de4085cSBen Gardon 23512de4085cSBen Gardon /* 23522de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 23532de4085cSBen Gardon * unlikely to be used again in the near future. This 23542de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 23552de4085cSBen Gardon */ 23562de4085cSBen Gardon if (tdp_enabled && invalid_list && 23572de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 23582de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 23592de4085cSBen Gardon invalid_list); 2360c50d8ae3SPaolo Bonzini } 2361ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2362c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2363ace569e0SSean Christopherson } 23642de4085cSBen Gardon return 0; 2365c50d8ae3SPaolo Bonzini } 2366c50d8ae3SPaolo Bonzini 23672de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 23682de4085cSBen Gardon struct kvm_mmu_page *sp, 23692de4085cSBen Gardon struct list_head *invalid_list) 2370c50d8ae3SPaolo Bonzini { 23712de4085cSBen Gardon int zapped = 0; 2372c50d8ae3SPaolo Bonzini unsigned i; 2373c50d8ae3SPaolo Bonzini 23742ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 23752de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 23762de4085cSBen Gardon 23772de4085cSBen Gardon return zapped; 2378c50d8ae3SPaolo Bonzini } 2379c50d8ae3SPaolo Bonzini 238061827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2381c50d8ae3SPaolo Bonzini { 2382c50d8ae3SPaolo Bonzini u64 *sptep; 2383c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2384c50d8ae3SPaolo Bonzini 2385c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2386c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2387c50d8ae3SPaolo Bonzini } 2388c50d8ae3SPaolo Bonzini 2389c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2390c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2391c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2392c50d8ae3SPaolo Bonzini { 2393c50d8ae3SPaolo Bonzini int i, zapped = 0; 2394c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2395c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2396c50d8ae3SPaolo Bonzini 23973bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2398c50d8ae3SPaolo Bonzini return 0; 2399c50d8ae3SPaolo Bonzini 2400c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2401c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2402c50d8ae3SPaolo Bonzini 2403c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2404c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2405c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2406c50d8ae3SPaolo Bonzini zapped++; 2407c50d8ae3SPaolo Bonzini } 2408c50d8ae3SPaolo Bonzini } 2409c50d8ae3SPaolo Bonzini 2410c50d8ae3SPaolo Bonzini return zapped; 2411c50d8ae3SPaolo Bonzini } 2412c50d8ae3SPaolo Bonzini 2413c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2414c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2415c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2416c50d8ae3SPaolo Bonzini int *nr_zapped) 2417c50d8ae3SPaolo Bonzini { 2418527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2419c50d8ae3SPaolo Bonzini 2420c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2421c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2422c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 24232de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 242461827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2425c50d8ae3SPaolo Bonzini 2426c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2427c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2428c50d8ae3SPaolo Bonzini 2429767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2430c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2431c50d8ae3SPaolo Bonzini 2432c50d8ae3SPaolo Bonzini if (sp->unsync) 2433c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2434c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2435c50d8ae3SPaolo Bonzini /* Count self */ 2436c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2437f95eec9bSSean Christopherson 2438f95eec9bSSean Christopherson /* 2439f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2440f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2441f95eec9bSSean Christopherson * !sp->root_count. 2442f95eec9bSSean Christopherson */ 2443f95eec9bSSean Christopherson if (sp->role.invalid) 2444f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2445f95eec9bSSean Christopherson else 2446c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 2447c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(kvm, -1); 2448c50d8ae3SPaolo Bonzini } else { 2449f95eec9bSSean Christopherson /* 2450f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2451f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2452f95eec9bSSean Christopherson */ 2453f95eec9bSSean Christopherson list_del(&sp->link); 2454c50d8ae3SPaolo Bonzini 2455c50d8ae3SPaolo Bonzini /* 2456c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2457c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2458c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2459c50d8ae3SPaolo Bonzini */ 2460527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2461c50d8ae3SPaolo Bonzini } 2462c50d8ae3SPaolo Bonzini 2463c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2464c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2465c50d8ae3SPaolo Bonzini 2466c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2467527d5cd7SSean Christopherson 2468527d5cd7SSean Christopherson /* 2469527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2470527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2471527d5cd7SSean Christopherson */ 2472527d5cd7SSean Christopherson if (zapped_root) 2473527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2474c50d8ae3SPaolo Bonzini return list_unstable; 2475c50d8ae3SPaolo Bonzini } 2476c50d8ae3SPaolo Bonzini 2477c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2478c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2479c50d8ae3SPaolo Bonzini { 2480c50d8ae3SPaolo Bonzini int nr_zapped; 2481c50d8ae3SPaolo Bonzini 2482c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2483c50d8ae3SPaolo Bonzini return nr_zapped; 2484c50d8ae3SPaolo Bonzini } 2485c50d8ae3SPaolo Bonzini 2486c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2487c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2488c50d8ae3SPaolo Bonzini { 2489c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2490c50d8ae3SPaolo Bonzini 2491c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2492c50d8ae3SPaolo Bonzini return; 2493c50d8ae3SPaolo Bonzini 2494c50d8ae3SPaolo Bonzini /* 2495c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2496c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2497c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2498c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2499c50d8ae3SPaolo Bonzini * 2500c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2501c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2502c50d8ae3SPaolo Bonzini */ 2503c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2504c50d8ae3SPaolo Bonzini 2505c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2506c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 250787654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2508c50d8ae3SPaolo Bonzini } 2509c50d8ae3SPaolo Bonzini } 2510c50d8ae3SPaolo Bonzini 25116b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 25126b82ef2cSSean Christopherson unsigned long nr_to_zap) 2513c50d8ae3SPaolo Bonzini { 25146b82ef2cSSean Christopherson unsigned long total_zapped = 0; 25156b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2516ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 25176b82ef2cSSean Christopherson bool unstable; 25186b82ef2cSSean Christopherson int nr_zapped; 2519c50d8ae3SPaolo Bonzini 2520c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2521ba7888ddSSean Christopherson return 0; 2522c50d8ae3SPaolo Bonzini 25236b82ef2cSSean Christopherson restart: 25248fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 25256b82ef2cSSean Christopherson /* 25266b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 25276b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 25286b82ef2cSSean Christopherson */ 25296b82ef2cSSean Christopherson if (sp->root_count) 25306b82ef2cSSean Christopherson continue; 25316b82ef2cSSean Christopherson 25326b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 25336b82ef2cSSean Christopherson &nr_zapped); 25346b82ef2cSSean Christopherson total_zapped += nr_zapped; 25356b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2536ba7888ddSSean Christopherson break; 2537ba7888ddSSean Christopherson 25386b82ef2cSSean Christopherson if (unstable) 25396b82ef2cSSean Christopherson goto restart; 2540ba7888ddSSean Christopherson } 25416b82ef2cSSean Christopherson 25426b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 25436b82ef2cSSean Christopherson 25446b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 25456b82ef2cSSean Christopherson return total_zapped; 25466b82ef2cSSean Christopherson } 25476b82ef2cSSean Christopherson 2548afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2549afe8d7e6SSean Christopherson { 2550afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2551afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2552afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2553afe8d7e6SSean Christopherson 2554afe8d7e6SSean Christopherson return 0; 2555c50d8ae3SPaolo Bonzini } 2556c50d8ae3SPaolo Bonzini 2557ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2558ba7888ddSSean Christopherson { 25596b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2560ba7888ddSSean Christopherson 25616b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2562ba7888ddSSean Christopherson return 0; 2563ba7888ddSSean Christopherson 25646b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2565ba7888ddSSean Christopherson 25666e6ec584SSean Christopherson /* 25676e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 25686e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 25696e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 25706e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2571c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 25726e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 25736e6ec584SSean Christopherson * page fault paths. 25746e6ec584SSean Christopherson */ 2575ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2576ba7888ddSSean Christopherson return -ENOSPC; 2577ba7888ddSSean Christopherson return 0; 2578ba7888ddSSean Christopherson } 2579ba7888ddSSean Christopherson 2580c50d8ae3SPaolo Bonzini /* 2581c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2582c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2583c50d8ae3SPaolo Bonzini */ 2584c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2585c50d8ae3SPaolo Bonzini { 2586531810caSBen Gardon write_lock(&kvm->mmu_lock); 2587c50d8ae3SPaolo Bonzini 2588c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 25896b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 25906b82ef2cSSean Christopherson goal_nr_mmu_pages); 2591c50d8ae3SPaolo Bonzini 2592c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2593c50d8ae3SPaolo Bonzini } 2594c50d8ae3SPaolo Bonzini 2595c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2596c50d8ae3SPaolo Bonzini 2597531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2598c50d8ae3SPaolo Bonzini } 2599c50d8ae3SPaolo Bonzini 2600c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2601c50d8ae3SPaolo Bonzini { 2602c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2603c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2604c50d8ae3SPaolo Bonzini int r; 2605c50d8ae3SPaolo Bonzini 2606c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2607c50d8ae3SPaolo Bonzini r = 0; 2608531810caSBen Gardon write_lock(&kvm->mmu_lock); 2609767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2610c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2611c50d8ae3SPaolo Bonzini sp->role.word); 2612c50d8ae3SPaolo Bonzini r = 1; 2613c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2614c50d8ae3SPaolo Bonzini } 2615c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2616531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2617c50d8ae3SPaolo Bonzini 2618c50d8ae3SPaolo Bonzini return r; 2619c50d8ae3SPaolo Bonzini } 262096ad91aeSSean Christopherson 262196ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 262296ad91aeSSean Christopherson { 262396ad91aeSSean Christopherson gpa_t gpa; 262496ad91aeSSean Christopherson int r; 262596ad91aeSSean Christopherson 2626347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 262796ad91aeSSean Christopherson return 0; 262896ad91aeSSean Christopherson 262996ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 263096ad91aeSSean Christopherson 263196ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 263296ad91aeSSean Christopherson 263396ad91aeSSean Christopherson return r; 263496ad91aeSSean Christopherson } 2635c50d8ae3SPaolo Bonzini 26364d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2637c50d8ae3SPaolo Bonzini { 2638c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 26394d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2640c50d8ae3SPaolo Bonzini sp->unsync = 1; 2641c50d8ae3SPaolo Bonzini 2642c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2643c50d8ae3SPaolo Bonzini } 2644c50d8ae3SPaolo Bonzini 26450337f585SSean Christopherson /* 26460337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 26470337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 26480337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 26490337f585SSean Christopherson * be write-protected. 26500337f585SSean Christopherson */ 26518283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 26522839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2653c50d8ae3SPaolo Bonzini { 2654c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2655ce25681dSSean Christopherson bool locked = false; 2656c50d8ae3SPaolo Bonzini 26570337f585SSean Christopherson /* 26580337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 26590337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 26600337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 26610337f585SSean Christopherson */ 26624d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 26630337f585SSean Christopherson return -EPERM; 2664c50d8ae3SPaolo Bonzini 26650337f585SSean Christopherson /* 26660337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 26670337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 26680337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 26690337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 26700337f585SSean Christopherson */ 2671767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2672c50d8ae3SPaolo Bonzini if (!can_unsync) 26730337f585SSean Christopherson return -EPERM; 2674c50d8ae3SPaolo Bonzini 2675c50d8ae3SPaolo Bonzini if (sp->unsync) 2676c50d8ae3SPaolo Bonzini continue; 2677c50d8ae3SPaolo Bonzini 26782839180cSPaolo Bonzini if (prefetch) 2679f1c4a88cSLai Jiangshan return -EEXIST; 2680f1c4a88cSLai Jiangshan 2681ce25681dSSean Christopherson /* 2682ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2683ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2684ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2685ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2686ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2687ce25681dSSean Christopherson */ 2688ce25681dSSean Christopherson if (!locked) { 2689ce25681dSSean Christopherson locked = true; 26904d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2691ce25681dSSean Christopherson 2692ce25681dSSean Christopherson /* 2693ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2694ce25681dSSean Christopherson * may have since marked the page unsync. A false 2695ce25681dSSean Christopherson * positive on the unprotected check above is not 2696ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2697ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2698ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2699ce25681dSSean Christopherson */ 2700ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2701ce25681dSSean Christopherson continue; 2702ce25681dSSean Christopherson } 2703ce25681dSSean Christopherson 27043bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 27054d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2706c50d8ae3SPaolo Bonzini } 2707ce25681dSSean Christopherson if (locked) 27084d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2709c50d8ae3SPaolo Bonzini 2710c50d8ae3SPaolo Bonzini /* 2711c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2712c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2713c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2714c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2715c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2716c50d8ae3SPaolo Bonzini * following could happen: 2717c50d8ae3SPaolo Bonzini * 2718c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2719c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2720c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2721c50d8ae3SPaolo Bonzini * to be writable 2722c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2723c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2724c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2725c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2726c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2727c50d8ae3SPaolo Bonzini * fault. 2728c50d8ae3SPaolo Bonzini * 2729c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2730c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2731c50d8ae3SPaolo Bonzini * 27320337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 27330337f585SSean Christopherson * false and skips the page. 2734c50d8ae3SPaolo Bonzini * 2735c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2736c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2737c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2738c50d8ae3SPaolo Bonzini * gets used. 2739c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2740c50d8ae3SPaolo Bonzini * as unsync 2741c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2742c50d8ae3SPaolo Bonzini * 2743c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2744264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2745264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2746c50d8ae3SPaolo Bonzini */ 2747c50d8ae3SPaolo Bonzini smp_wmb(); 2748c50d8ae3SPaolo Bonzini 27490337f585SSean Christopherson return 0; 2750c50d8ae3SPaolo Bonzini } 2751c50d8ae3SPaolo Bonzini 27528a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 27538a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2754a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2755799a4190SBen Gardon { 2756d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2757eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2758c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2759c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2760c50d8ae3SPaolo Bonzini bool flush = false; 2761ad67e480SPaolo Bonzini bool wrprot; 2762d786c778SPaolo Bonzini u64 spte; 2763c50d8ae3SPaolo Bonzini 2764a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2765a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 27662839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2767a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2768c50d8ae3SPaolo Bonzini 2769c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2770c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2771c50d8ae3SPaolo Bonzini 2772a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 27731075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2774a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2775a54aa15cSSean Christopherson return RET_PF_EMULATE; 2776a54aa15cSSean Christopherson } 2777a54aa15cSSean Christopherson 2778c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2779c50d8ae3SPaolo Bonzini /* 2780c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2781c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2782c50d8ae3SPaolo Bonzini */ 27833bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2784c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2785c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2786c50d8ae3SPaolo Bonzini 27872ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2788c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2789c50d8ae3SPaolo Bonzini flush = true; 2790c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2791c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2792c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2793c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2794c50d8ae3SPaolo Bonzini flush = true; 2795c50d8ae3SPaolo Bonzini } else 2796c50d8ae3SPaolo Bonzini was_rmapped = 1; 2797c50d8ae3SPaolo Bonzini } 2798c50d8ae3SPaolo Bonzini 27992839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 28007158bee4SPaolo Bonzini true, host_writable, &spte); 2801d786c778SPaolo Bonzini 2802d786c778SPaolo Bonzini if (*sptep == spte) { 2803d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2804d786c778SPaolo Bonzini } else { 2805d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 28065959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2807c50d8ae3SPaolo Bonzini } 2808c50d8ae3SPaolo Bonzini 2809ad67e480SPaolo Bonzini if (wrprot) { 2810c50d8ae3SPaolo Bonzini if (write_fault) 2811c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2812c50d8ae3SPaolo Bonzini } 2813c50d8ae3SPaolo Bonzini 2814d786c778SPaolo Bonzini if (flush) 2815c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2816c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2817c50d8ae3SPaolo Bonzini 2818c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2819c50d8ae3SPaolo Bonzini 2820c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2821d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 2822*6a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 2823*6a97575dSDavid Matlack } else { 2824*6a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 2825*6a97575dSDavid Matlack kvm_mmu_page_set_access(sp, sptep - sp->spt, pte_access); 2826c50d8ae3SPaolo Bonzini } 2827c50d8ae3SPaolo Bonzini 2828c50d8ae3SPaolo Bonzini return ret; 2829c50d8ae3SPaolo Bonzini } 2830c50d8ae3SPaolo Bonzini 2831c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2832c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2833c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2834c50d8ae3SPaolo Bonzini { 2835c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2836c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 28370a2b64c5SBen Gardon unsigned int access = sp->role.access; 2838c50d8ae3SPaolo Bonzini int i, ret; 2839c50d8ae3SPaolo Bonzini gfn_t gfn; 2840c50d8ae3SPaolo Bonzini 2841c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt); 2842c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2843c50d8ae3SPaolo Bonzini if (!slot) 2844c50d8ae3SPaolo Bonzini return -1; 2845c50d8ae3SPaolo Bonzini 2846c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2847c50d8ae3SPaolo Bonzini if (ret <= 0) 2848c50d8ae3SPaolo Bonzini return -1; 2849c50d8ae3SPaolo Bonzini 2850c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 28518a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2852a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2853c50d8ae3SPaolo Bonzini put_page(pages[i]); 2854c50d8ae3SPaolo Bonzini } 2855c50d8ae3SPaolo Bonzini 2856c50d8ae3SPaolo Bonzini return 0; 2857c50d8ae3SPaolo Bonzini } 2858c50d8ae3SPaolo Bonzini 2859c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2860c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2861c50d8ae3SPaolo Bonzini { 2862c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2863c50d8ae3SPaolo Bonzini int i; 2864c50d8ae3SPaolo Bonzini 2865c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2866c50d8ae3SPaolo Bonzini 2867c50d8ae3SPaolo Bonzini i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); 2868c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2869c50d8ae3SPaolo Bonzini 2870c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2871c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2872c50d8ae3SPaolo Bonzini if (!start) 2873c50d8ae3SPaolo Bonzini continue; 2874c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2875c6cecc4bSSean Christopherson return; 2876c50d8ae3SPaolo Bonzini start = NULL; 2877c50d8ae3SPaolo Bonzini } else if (!start) 2878c50d8ae3SPaolo Bonzini start = spte; 2879c50d8ae3SPaolo Bonzini } 2880c6cecc4bSSean Christopherson if (start) 2881c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2882c50d8ae3SPaolo Bonzini } 2883c50d8ae3SPaolo Bonzini 2884c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2885c50d8ae3SPaolo Bonzini { 2886c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2887c50d8ae3SPaolo Bonzini 288857354682SSean Christopherson sp = sptep_to_sp(sptep); 2889c50d8ae3SPaolo Bonzini 2890c50d8ae3SPaolo Bonzini /* 2891c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2892c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2893c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2894c50d8ae3SPaolo Bonzini */ 2895c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2896c50d8ae3SPaolo Bonzini return; 2897c50d8ae3SPaolo Bonzini 28983bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2899c50d8ae3SPaolo Bonzini return; 2900c50d8ae3SPaolo Bonzini 29014a42d848SDavid Stevens /* 29024a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 29034a42d848SDavid Stevens * accidentally prefetching those addresses. 29044a42d848SDavid Stevens */ 29054a42d848SDavid Stevens if (unlikely(vcpu->kvm->mmu_notifier_count)) 29064a42d848SDavid Stevens return; 29074a42d848SDavid Stevens 2908c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2909c50d8ae3SPaolo Bonzini } 2910c50d8ae3SPaolo Bonzini 29111b6d9d9eSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, 29128ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2913db543216SSean Christopherson { 2914284dc493SSean Christopherson int level = PG_LEVEL_4K; 29155d49f08cSSean Christopherson struct page *page; 2916db543216SSean Christopherson unsigned long hva; 291744187235SMingwei Zhang unsigned long flags; 291844187235SMingwei Zhang pgd_t pgd; 291944187235SMingwei Zhang p4d_t p4d; 292044187235SMingwei Zhang pud_t pud; 292144187235SMingwei Zhang pmd_t pmd; 2922db543216SSean Christopherson 29235d49f08cSSean Christopherson /* 29245d49f08cSSean Christopherson * Note, @slot must be non-NULL, i.e. the caller is responsible for 29255d49f08cSSean Christopherson * ensuring @pfn isn't garbage and is backed by a memslot. 29265d49f08cSSean Christopherson */ 29275d49f08cSSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 29285d49f08cSSean Christopherson if (!page) 29295d49f08cSSean Christopherson return PG_LEVEL_4K; 29305d49f08cSSean Christopherson 2931284dc493SSean Christopherson if (!PageCompound(page) && !kvm_is_zone_device_page(page)) 29323bae0459SSean Christopherson return PG_LEVEL_4K; 2933db543216SSean Christopherson 2934293e306eSSean Christopherson /* 2935293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2936293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2937293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2938293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2939293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2940293e306eSSean Christopherson * read-only memslot. 2941293e306eSSean Christopherson */ 2942db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2943db543216SSean Christopherson 294444187235SMingwei Zhang /* 294544187235SMingwei Zhang * Lookup the mapping level in the current mm. The information 294644187235SMingwei Zhang * may become stale soon, but it is safe to use as long as 294744187235SMingwei Zhang * 1) mmu_notifier_retry was checked after taking mmu_lock, and 294844187235SMingwei Zhang * 2) mmu_lock is taken now. 294944187235SMingwei Zhang * 295044187235SMingwei Zhang * We still need to disable IRQs to prevent concurrent tear down 295144187235SMingwei Zhang * of page tables. 295244187235SMingwei Zhang */ 295344187235SMingwei Zhang local_irq_save(flags); 2954db543216SSean Christopherson 295544187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 295644187235SMingwei Zhang if (pgd_none(pgd)) 295744187235SMingwei Zhang goto out; 295844187235SMingwei Zhang 295944187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 296044187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 296144187235SMingwei Zhang goto out; 296244187235SMingwei Zhang 296344187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 296444187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 296544187235SMingwei Zhang goto out; 296644187235SMingwei Zhang 296744187235SMingwei Zhang if (pud_large(pud)) { 296844187235SMingwei Zhang level = PG_LEVEL_1G; 296944187235SMingwei Zhang goto out; 297044187235SMingwei Zhang } 297144187235SMingwei Zhang 297244187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 297344187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 297444187235SMingwei Zhang goto out; 297544187235SMingwei Zhang 297644187235SMingwei Zhang if (pmd_large(pmd)) 297744187235SMingwei Zhang level = PG_LEVEL_2M; 297844187235SMingwei Zhang 297944187235SMingwei Zhang out: 298044187235SMingwei Zhang local_irq_restore(flags); 2981db543216SSean Christopherson return level; 2982db543216SSean Christopherson } 2983db543216SSean Christopherson 29848ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 29858ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 29868ca6f063SBen Gardon kvm_pfn_t pfn, int max_level) 29871b6d9d9eSSean Christopherson { 29881b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 2989ec607a56SPaolo Bonzini int host_level; 29901b6d9d9eSSean Christopherson 29911b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 29921b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 29931b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 29941b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 29951b6d9d9eSSean Christopherson break; 29961b6d9d9eSSean Christopherson } 29971b6d9d9eSSean Christopherson 29981b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 29991b6d9d9eSSean Christopherson return PG_LEVEL_4K; 30001b6d9d9eSSean Christopherson 3001ec607a56SPaolo Bonzini host_level = host_pfn_mapping_level(kvm, gfn, pfn, slot); 3002ec607a56SPaolo Bonzini return min(host_level, max_level); 30031b6d9d9eSSean Christopherson } 30041b6d9d9eSSean Christopherson 300573a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 30060885904dSSean Christopherson { 3007e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 300817eff019SSean Christopherson kvm_pfn_t mask; 30090885904dSSean Christopherson 301073a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 30113cf06612SSean Christopherson 301273a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 301373a3c659SPaolo Bonzini return; 301417eff019SSean Christopherson 30155d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 301673a3c659SPaolo Bonzini return; 301717eff019SSean Christopherson 3018e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 301973a3c659SPaolo Bonzini return; 3020293e306eSSean Christopherson 30213cf06612SSean Christopherson /* 30223cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 30233cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 30243cf06612SSean Christopherson */ 302573a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 302673a3c659SPaolo Bonzini fault->gfn, fault->pfn, 302773a3c659SPaolo Bonzini fault->max_level); 302873a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 302973a3c659SPaolo Bonzini return; 30304cd071d1SSean Christopherson 30310885904dSSean Christopherson /* 30324cd071d1SSean Christopherson * mmu_notifier_retry() was successful and mmu_lock is held, so 30334cd071d1SSean Christopherson * the pmd can't be split from under us. 30340885904dSSean Christopherson */ 303573a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 303673a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 303773a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 303873a3c659SPaolo Bonzini fault->pfn &= ~mask; 30390885904dSSean Christopherson } 30400885904dSSean Christopherson 3041536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3042c50d8ae3SPaolo Bonzini { 3043536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3044536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3045c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 3046c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 3047c50d8ae3SPaolo Bonzini /* 3048c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 3049c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 3050c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 3051c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 3052c50d8ae3SPaolo Bonzini * the address. 3053c50d8ae3SPaolo Bonzini */ 3054536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3055536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3056536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3057536f0e6aSPaolo Bonzini fault->goal_level--; 3058c50d8ae3SPaolo Bonzini } 3059c50d8ae3SPaolo Bonzini } 3060c50d8ae3SPaolo Bonzini 306143b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3062c50d8ae3SPaolo Bonzini { 3063c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3064c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 306573a3c659SPaolo Bonzini int ret; 306643b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3067c50d8ae3SPaolo Bonzini 306873a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 30694cd071d1SSean Christopherson 3070f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 307143b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3072c50d8ae3SPaolo Bonzini /* 3073c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3074c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3075c50d8ae3SPaolo Bonzini */ 307673a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3077536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3078c50d8ae3SPaolo Bonzini 307943b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 308073a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3081c50d8ae3SPaolo Bonzini break; 3082c50d8ae3SPaolo Bonzini 3083c50d8ae3SPaolo Bonzini drop_large_spte(vcpu, it.sptep); 308403fffc54SSean Christopherson if (is_shadow_present_pte(*it.sptep)) 308503fffc54SSean Christopherson continue; 308603fffc54SSean Christopherson 30872e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 3088c50d8ae3SPaolo Bonzini 3089c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 309073a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 309173a3c659SPaolo Bonzini fault->req_level >= it.level) 3092c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 3093c50d8ae3SPaolo Bonzini } 3094c50d8ae3SPaolo Bonzini 3095b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3096b1a429fbSSean Christopherson return -EFAULT; 3097b1a429fbSSean Christopherson 30988a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3099a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 310012703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 310112703759SSean Christopherson return ret; 310212703759SSean Christopherson 3103c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3104c50d8ae3SPaolo Bonzini return ret; 3105c50d8ae3SPaolo Bonzini } 3106c50d8ae3SPaolo Bonzini 3107c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 3108c50d8ae3SPaolo Bonzini { 3109c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 3110c50d8ae3SPaolo Bonzini } 3111c50d8ae3SPaolo Bonzini 3112c50d8ae3SPaolo Bonzini static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 3113c50d8ae3SPaolo Bonzini { 3114c50d8ae3SPaolo Bonzini /* 3115c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3116c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3117c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3118c50d8ae3SPaolo Bonzini */ 3119c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3120c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3121c50d8ae3SPaolo Bonzini 3122c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3123c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3124c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3125c50d8ae3SPaolo Bonzini } 3126c50d8ae3SPaolo Bonzini 3127c50d8ae3SPaolo Bonzini return -EFAULT; 3128c50d8ae3SPaolo Bonzini } 3129c50d8ae3SPaolo Bonzini 31305276c616SSean Christopherson static int handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 31315276c616SSean Christopherson unsigned int access) 3132c50d8ae3SPaolo Bonzini { 3133c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 31345276c616SSean Christopherson if (unlikely(is_error_pfn(fault->pfn))) 31355276c616SSean Christopherson return kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); 3136c50d8ae3SPaolo Bonzini 3137e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 31383a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 31393a13f4feSPaolo Bonzini 31403a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3141c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 314230ab5901SSean Christopherson /* 314330ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 314430ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 314586931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 314686931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 314786931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 314886931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 314986931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 315086931ff7SSean Christopherson * the hardware's). 315130ab5901SSean Christopherson */ 31528b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 31535276c616SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) 31545276c616SSean Christopherson return RET_PF_EMULATE; 315530ab5901SSean Christopherson } 3156c50d8ae3SPaolo Bonzini 31575276c616SSean Christopherson return RET_PF_CONTINUE; 3158c50d8ae3SPaolo Bonzini } 3159c50d8ae3SPaolo Bonzini 31603c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3161c50d8ae3SPaolo Bonzini { 3162c50d8ae3SPaolo Bonzini /* 31635c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 31645c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 31655c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 31665c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3167c50d8ae3SPaolo Bonzini */ 31683c8ad5a6SPaolo Bonzini if (fault->rsvd) 3169c50d8ae3SPaolo Bonzini return false; 3170c50d8ae3SPaolo Bonzini 3171c50d8ae3SPaolo Bonzini /* 3172c50d8ae3SPaolo Bonzini * #PF can be fast if: 3173c50d8ae3SPaolo Bonzini * 317454275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 317554275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 317654275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 317754275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 317854275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 317954275f74SSean Christopherson * mechanism only supports direct MMUs. 318054275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 318154275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 318254275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 318354275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 318454275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3185c50d8ae3SPaolo Bonzini */ 31865c64aba5SSean Christopherson if (!fault->present) 31875c64aba5SSean Christopherson return !kvm_ad_enabled(); 31885c64aba5SSean Christopherson 31895c64aba5SSean Christopherson /* 31905c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 31915c64aba5SSean Christopherson * the "exec" flag. 31925c64aba5SSean Christopherson */ 31935c64aba5SSean Christopherson return fault->write; 3194c50d8ae3SPaolo Bonzini } 3195c50d8ae3SPaolo Bonzini 3196c50d8ae3SPaolo Bonzini /* 3197c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3198c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3199c50d8ae3SPaolo Bonzini */ 3200c50d8ae3SPaolo Bonzini static bool 3201e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3202c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3203c50d8ae3SPaolo Bonzini { 3204c50d8ae3SPaolo Bonzini /* 3205c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3206c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3207c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3208c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3209c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3210c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3211c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3212c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3213c50d8ae3SPaolo Bonzini * 3214c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3215c50d8ae3SPaolo Bonzini */ 32162db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3217c50d8ae3SPaolo Bonzini return false; 3218c50d8ae3SPaolo Bonzini 3219e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3220e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3221c50d8ae3SPaolo Bonzini 3222c50d8ae3SPaolo Bonzini return true; 3223c50d8ae3SPaolo Bonzini } 3224c50d8ae3SPaolo Bonzini 32253c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3226c50d8ae3SPaolo Bonzini { 32273c8ad5a6SPaolo Bonzini if (fault->exec) 3228c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3229c50d8ae3SPaolo Bonzini 32303c8ad5a6SPaolo Bonzini if (fault->write) 3231c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3232c50d8ae3SPaolo Bonzini 3233c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3234c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3235c50d8ae3SPaolo Bonzini } 3236c50d8ae3SPaolo Bonzini 3237c50d8ae3SPaolo Bonzini /* 32386e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 32396e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 32406e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 32416e8eb206SDavid Matlack * 32426e8eb206SDavid Matlack * Contract: 32436e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 32446e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 32456e8eb206SDavid Matlack */ 32466e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 32476e8eb206SDavid Matlack { 32486e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 32496e8eb206SDavid Matlack u64 old_spte; 32506e8eb206SDavid Matlack u64 *sptep = NULL; 32516e8eb206SDavid Matlack 32526e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 32536e8eb206SDavid Matlack sptep = iterator.sptep; 32546e8eb206SDavid Matlack *spte = old_spte; 32556e8eb206SDavid Matlack } 32566e8eb206SDavid Matlack 32576e8eb206SDavid Matlack return sptep; 32586e8eb206SDavid Matlack } 32596e8eb206SDavid Matlack 32606e8eb206SDavid Matlack /* 3261c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3262c50d8ae3SPaolo Bonzini */ 32633c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3264c50d8ae3SPaolo Bonzini { 3265c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3266c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3267c50d8ae3SPaolo Bonzini u64 spte = 0ull; 32686e8eb206SDavid Matlack u64 *sptep = NULL; 3269c50d8ae3SPaolo Bonzini uint retry_count = 0; 3270c50d8ae3SPaolo Bonzini 32713c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3272c4371c2aSSean Christopherson return ret; 3273c50d8ae3SPaolo Bonzini 3274c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3275c50d8ae3SPaolo Bonzini 3276c50d8ae3SPaolo Bonzini do { 3277c50d8ae3SPaolo Bonzini u64 new_spte; 3278c50d8ae3SPaolo Bonzini 32796e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 32803c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 32816e8eb206SDavid Matlack else 32823c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3283c50d8ae3SPaolo Bonzini 3284ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3285ec89e643SSean Christopherson break; 3286ec89e643SSean Christopherson 32876e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3288c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3289c50d8ae3SPaolo Bonzini break; 3290c50d8ae3SPaolo Bonzini 3291c50d8ae3SPaolo Bonzini /* 3292c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3293c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3294c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3295c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3296c50d8ae3SPaolo Bonzini * current CPU took the fault. 3297c50d8ae3SPaolo Bonzini * 3298c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3299c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3300c50d8ae3SPaolo Bonzini */ 33013c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3302c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3303c50d8ae3SPaolo Bonzini break; 3304c50d8ae3SPaolo Bonzini } 3305c50d8ae3SPaolo Bonzini 3306c50d8ae3SPaolo Bonzini new_spte = spte; 3307c50d8ae3SPaolo Bonzini 330854275f74SSean Christopherson /* 330954275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 331054275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 331154275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 331254275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 331354275f74SSean Christopherson */ 331454275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3315c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3316c50d8ae3SPaolo Bonzini 3317c50d8ae3SPaolo Bonzini /* 331854275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 331954275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 332054275f74SSean Christopherson * that were write-protected for dirty-logging or access 332154275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 332254275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 332354275f74SSean Christopherson * The is_access_allowed() check above handles the common case 332454275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 332554275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 332654275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3327c50d8ae3SPaolo Bonzini */ 3328706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3329c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3330c50d8ae3SPaolo Bonzini 3331c50d8ae3SPaolo Bonzini /* 333210c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 333310c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 333410c30de0SJunaid Shahid * first page into the dirty-bitmap in 3335c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3336c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3337c50d8ae3SPaolo Bonzini * 3338c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3339c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3340c50d8ae3SPaolo Bonzini */ 334110c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 334210c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3343c50d8ae3SPaolo Bonzini break; 3344c50d8ae3SPaolo Bonzini } 3345c50d8ae3SPaolo Bonzini 3346c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3347c50d8ae3SPaolo Bonzini if (new_spte == spte || 33483c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3349c50d8ae3SPaolo Bonzini break; 3350c50d8ae3SPaolo Bonzini 3351c50d8ae3SPaolo Bonzini /* 3352c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3353c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 33543ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3355c50d8ae3SPaolo Bonzini */ 3356e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3357c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3358c50d8ae3SPaolo Bonzini break; 3359c4371c2aSSean Christopherson } 3360c50d8ae3SPaolo Bonzini 3361c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3362c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3363c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3364c50d8ae3SPaolo Bonzini break; 3365c50d8ae3SPaolo Bonzini } 3366c50d8ae3SPaolo Bonzini 3367c50d8ae3SPaolo Bonzini } while (true); 3368c50d8ae3SPaolo Bonzini 3369f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3370c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3371c50d8ae3SPaolo Bonzini 33721075d41eSSean Christopherson if (ret != RET_PF_INVALID) 33731075d41eSSean Christopherson vcpu->stat.pf_fast++; 33741075d41eSSean Christopherson 3375c4371c2aSSean Christopherson return ret; 3376c50d8ae3SPaolo Bonzini } 3377c50d8ae3SPaolo Bonzini 3378c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3379c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3380c50d8ae3SPaolo Bonzini { 3381c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3382c50d8ae3SPaolo Bonzini 3383c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3384c50d8ae3SPaolo Bonzini return; 3385c50d8ae3SPaolo Bonzini 33862ca3129eSSean Christopherson sp = to_shadow_page(*root_hpa & SPTE_BASE_ADDR_MASK); 33879191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 33889191b8f0SPaolo Bonzini return; 338902c00b3aSBen Gardon 3390897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 33916103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 339276eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3393c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3394c50d8ae3SPaolo Bonzini 3395c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3396c50d8ae3SPaolo Bonzini } 3397c50d8ae3SPaolo Bonzini 3398c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 33990c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3400c50d8ae3SPaolo Bonzini ulong roots_to_free) 3401c50d8ae3SPaolo Bonzini { 3402c50d8ae3SPaolo Bonzini int i; 3403c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3404594bef79SPaolo Bonzini bool free_active_root; 3405c50d8ae3SPaolo Bonzini 3406c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3407c50d8ae3SPaolo Bonzini 3408c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3409594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3410594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3411594bef79SPaolo Bonzini 3412594bef79SPaolo Bonzini if (!free_active_root) { 3413c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3414c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3415c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3416c50d8ae3SPaolo Bonzini break; 3417c50d8ae3SPaolo Bonzini 3418c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3419c50d8ae3SPaolo Bonzini return; 3420c50d8ae3SPaolo Bonzini } 3421c50d8ae3SPaolo Bonzini 3422531810caSBen Gardon write_lock(&kvm->mmu_lock); 3423c50d8ae3SPaolo Bonzini 3424c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3425c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 34264d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3427c50d8ae3SPaolo Bonzini &invalid_list); 3428c50d8ae3SPaolo Bonzini 3429c50d8ae3SPaolo Bonzini if (free_active_root) { 3430594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3431b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 343204d45551SSean Christopherson } else if (mmu->pae_root) { 3433c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3434c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3435c834e5e4SSean Christopherson continue; 3436c834e5e4SSean Christopherson 3437c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3438c50d8ae3SPaolo Bonzini &invalid_list); 3439c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3440c50d8ae3SPaolo Bonzini } 3441c50d8ae3SPaolo Bonzini } 3442b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3443b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3444c50d8ae3SPaolo Bonzini } 3445c50d8ae3SPaolo Bonzini 34464d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3447531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3448c50d8ae3SPaolo Bonzini } 3449c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3450c50d8ae3SPaolo Bonzini 34510c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 345225b62c62SSean Christopherson { 345325b62c62SSean Christopherson unsigned long roots_to_free = 0; 345425b62c62SSean Christopherson hpa_t root_hpa; 345525b62c62SSean Christopherson int i; 345625b62c62SSean Christopherson 345725b62c62SSean Christopherson /* 345825b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 345925b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 346025b62c62SSean Christopherson */ 34617a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 346225b62c62SSean Christopherson 346325b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 346425b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 346525b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 346625b62c62SSean Christopherson continue; 346725b62c62SSean Christopherson 346825b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 346925b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 347025b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 347125b62c62SSean Christopherson } 347225b62c62SSean Christopherson 34730c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 347425b62c62SSean Christopherson } 347525b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 347625b62c62SSean Christopherson 347725b62c62SSean Christopherson 3478c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3479c50d8ae3SPaolo Bonzini { 3480c50d8ae3SPaolo Bonzini int ret = 0; 3481c50d8ae3SPaolo Bonzini 3482995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3483c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3484c50d8ae3SPaolo Bonzini ret = 1; 3485c50d8ae3SPaolo Bonzini } 3486c50d8ae3SPaolo Bonzini 3487c50d8ae3SPaolo Bonzini return ret; 3488c50d8ae3SPaolo Bonzini } 3489c50d8ae3SPaolo Bonzini 34902e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 349186938ab6SDavid Matlack u8 level) 3492c50d8ae3SPaolo Bonzini { 34932e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3494c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 34958123f265SSean Christopherson 34962e65e842SDavid Matlack role.level = level; 34972e65e842SDavid Matlack role.quadrant = quadrant; 34982e65e842SDavid Matlack 34997f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 35007f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 35017f497775SDavid Matlack 350287654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 35038123f265SSean Christopherson ++sp->root_count; 35048123f265SSean Christopherson 35058123f265SSean Christopherson return __pa(sp->spt); 35068123f265SSean Christopherson } 35078123f265SSean Christopherson 35088123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 35098123f265SSean Christopherson { 3510b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3511a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 35128123f265SSean Christopherson hpa_t root; 3513c50d8ae3SPaolo Bonzini unsigned i; 35144a38162eSPaolo Bonzini int r; 35154a38162eSPaolo Bonzini 35164a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35174a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35184a38162eSPaolo Bonzini if (r < 0) 35194a38162eSPaolo Bonzini goto out_unlock; 3520c50d8ae3SPaolo Bonzini 3521897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 352202c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3523b9e5603cSPaolo Bonzini mmu->root.hpa = root; 352402c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 352586938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3526b9e5603cSPaolo Bonzini mmu->root.hpa = root; 35278123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 35284a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35294a38162eSPaolo Bonzini r = -EIO; 35304a38162eSPaolo Bonzini goto out_unlock; 35314a38162eSPaolo Bonzini } 353273ad1606SSean Christopherson 3533c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3534c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3535c50d8ae3SPaolo Bonzini 35367f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 35372e65e842SDavid Matlack PT32_ROOT_LEVEL); 353817e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3539d2263de1SYuan Yao shadow_me_value; 3540c50d8ae3SPaolo Bonzini } 3541b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 354273ad1606SSean Christopherson } else { 354373ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 35444a38162eSPaolo Bonzini r = -EIO; 35454a38162eSPaolo Bonzini goto out_unlock; 354673ad1606SSean Christopherson } 35473651c7fcSSean Christopherson 3548b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3549b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 35504a38162eSPaolo Bonzini out_unlock: 35514a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 35524a38162eSPaolo Bonzini return r; 3553c50d8ae3SPaolo Bonzini } 3554c50d8ae3SPaolo Bonzini 35551e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 35561e76a3ceSDavid Stevens { 35571e76a3ceSDavid Stevens struct kvm_memslots *slots; 35581e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3559a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 35601e76a3ceSDavid Stevens 35611e76a3ceSDavid Stevens /* 35621e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 35631e76a3ceSDavid Stevens * taking the lock. 35641e76a3ceSDavid Stevens */ 35651e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 35661e76a3ceSDavid Stevens return 0; 35671e76a3ceSDavid Stevens 35681e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 35691e76a3ceSDavid Stevens 35701e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 35711e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 35721e76a3ceSDavid Stevens goto out_unlock; 35731e76a3ceSDavid Stevens 35741e76a3ceSDavid Stevens /* 35751e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 35761e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 35771e76a3ceSDavid Stevens */ 35781e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 35791e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 35801e76a3ceSDavid Stevens goto out_success; 35811e76a3ceSDavid Stevens 35821e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 35831e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3584a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 35851e76a3ceSDavid Stevens /* 35861e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 35871e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 35881e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 35891e76a3ceSDavid Stevens * failure to avoid having to track which allocations 35901e76a3ceSDavid Stevens * were made now versus when the memslot was created. 35911e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 35921e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 35931e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 35941e76a3ceSDavid Stevens */ 35951e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 35961e76a3ceSDavid Stevens if (r) 35971e76a3ceSDavid Stevens goto out_unlock; 35981e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 35991e76a3ceSDavid Stevens if (r) 36001e76a3ceSDavid Stevens goto out_unlock; 36011e76a3ceSDavid Stevens } 36021e76a3ceSDavid Stevens } 36031e76a3ceSDavid Stevens 36041e76a3ceSDavid Stevens /* 36051e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 36061e76a3ceSDavid Stevens * all the related pointers are set. 36071e76a3ceSDavid Stevens */ 36081e76a3ceSDavid Stevens out_success: 36091e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 36101e76a3ceSDavid Stevens 36111e76a3ceSDavid Stevens out_unlock: 36121e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 36131e76a3ceSDavid Stevens return r; 36141e76a3ceSDavid Stevens } 36151e76a3ceSDavid Stevens 3616c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3617c50d8ae3SPaolo Bonzini { 3618b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 36196e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3620be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 36217f497775SDavid Matlack int quadrant, i, r; 36228123f265SSean Christopherson hpa_t root; 3623c50d8ae3SPaolo Bonzini 3624b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3625be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3626c50d8ae3SPaolo Bonzini 3627c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3628c50d8ae3SPaolo Bonzini return 1; 3629c50d8ae3SPaolo Bonzini 3630c50d8ae3SPaolo Bonzini /* 36314a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 36324a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 36334a38162eSPaolo Bonzini */ 36344d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 36356e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 36366e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 36376e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 36386e0918aeSSean Christopherson continue; 36396e0918aeSSean Christopherson 36406e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 36416e0918aeSSean Christopherson return 1; 36426e0918aeSSean Christopherson } 36436e0918aeSSean Christopherson } 36446e0918aeSSean Christopherson 36451e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3646d501f747SBen Gardon if (r) 3647d501f747SBen Gardon return r; 3648d501f747SBen Gardon 36494a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36504a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36514a38162eSPaolo Bonzini if (r < 0) 36524a38162eSPaolo Bonzini goto out_unlock; 36534a38162eSPaolo Bonzini 3654c50d8ae3SPaolo Bonzini /* 3655c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3656c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3657c50d8ae3SPaolo Bonzini */ 36584d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 36598123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 366086938ab6SDavid Matlack mmu->root_role.level); 3661b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3662be01e8e2SSean Christopherson goto set_root_pgd; 3663c50d8ae3SPaolo Bonzini } 3664c50d8ae3SPaolo Bonzini 36654a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 36664a38162eSPaolo Bonzini r = -EIO; 36674a38162eSPaolo Bonzini goto out_unlock; 36684a38162eSPaolo Bonzini } 366973ad1606SSean Christopherson 3670c50d8ae3SPaolo Bonzini /* 3671c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3672c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3673c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3674c50d8ae3SPaolo Bonzini */ 3675e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3676a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3677c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3678c50d8ae3SPaolo Bonzini 367903ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 36804a38162eSPaolo Bonzini r = -EIO; 36814a38162eSPaolo Bonzini goto out_unlock; 36824a38162eSPaolo Bonzini } 368303ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3684cb0f722aSWei Huang 3685a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3686cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3687cb0f722aSWei Huang r = -EIO; 3688cb0f722aSWei Huang goto out_unlock; 3689cb0f722aSWei Huang } 3690cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3691cb0f722aSWei Huang } 369204d45551SSean Christopherson } 369304d45551SSean Christopherson 3694c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3695c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 36966e6ec584SSean Christopherson 36974d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 36986e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3699c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3700c50d8ae3SPaolo Bonzini continue; 3701c50d8ae3SPaolo Bonzini } 37026e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3703c50d8ae3SPaolo Bonzini } 3704c50d8ae3SPaolo Bonzini 37057f497775SDavid Matlack /* 37067f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 37077f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 37087f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 37097f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 37107f497775SDavid Matlack */ 37117f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 37127f497775SDavid Matlack 37137f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3714b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3715c50d8ae3SPaolo Bonzini } 3716c50d8ae3SPaolo Bonzini 3717a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3718b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3719a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3720b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3721ba0a194fSSean Christopherson else 3722b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3723c50d8ae3SPaolo Bonzini 3724be01e8e2SSean Christopherson set_root_pgd: 3725b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 37264a38162eSPaolo Bonzini out_unlock: 37274a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3728c50d8ae3SPaolo Bonzini 3729c6c937d6SLike Xu return r; 3730c50d8ae3SPaolo Bonzini } 3731c50d8ae3SPaolo Bonzini 3732748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3733c50d8ae3SPaolo Bonzini { 3734748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3735a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3736cb0f722aSWei Huang u64 *pml5_root = NULL; 3737cb0f722aSWei Huang u64 *pml4_root = NULL; 3738cb0f722aSWei Huang u64 *pae_root; 3739748e52b9SSean Christopherson 3740748e52b9SSean Christopherson /* 3741748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3742748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3743748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3744748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3745748e52b9SSean Christopherson */ 3746347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3747347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3748a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3749748e52b9SSean Christopherson return 0; 3750748e52b9SSean Christopherson 3751a717a780SSean Christopherson /* 3752a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3753a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3754a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3755a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3756a717a780SSean Christopherson * prior MMU would also have required pml5. 3757a717a780SSean Christopherson */ 3758a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3759748e52b9SSean Christopherson return 0; 3760748e52b9SSean Christopherson 3761748e52b9SSean Christopherson /* 3762748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3763748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3764748e52b9SSean Christopherson */ 3765cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3766a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3767748e52b9SSean Christopherson return -EIO; 3768748e52b9SSean Christopherson 37694a98623dSSean Christopherson /* 37704a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 37714a98623dSSean Christopherson * doesn't need to be decrypted. 37724a98623dSSean Christopherson */ 3773748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3774748e52b9SSean Christopherson if (!pae_root) 3775748e52b9SSean Christopherson return -ENOMEM; 3776748e52b9SSean Christopherson 3777cb0f722aSWei Huang #ifdef CONFIG_X86_64 377803ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3779cb0f722aSWei Huang if (!pml4_root) 3780cb0f722aSWei Huang goto err_pml4; 3781cb0f722aSWei Huang 3782a717a780SSean Christopherson if (need_pml5) { 3783cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3784cb0f722aSWei Huang if (!pml5_root) 3785cb0f722aSWei Huang goto err_pml5; 3786748e52b9SSean Christopherson } 3787cb0f722aSWei Huang #endif 3788748e52b9SSean Christopherson 3789748e52b9SSean Christopherson mmu->pae_root = pae_root; 379003ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3791cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3792748e52b9SSean Christopherson 3793748e52b9SSean Christopherson return 0; 3794cb0f722aSWei Huang 3795cb0f722aSWei Huang #ifdef CONFIG_X86_64 3796cb0f722aSWei Huang err_pml5: 3797cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3798cb0f722aSWei Huang err_pml4: 3799cb0f722aSWei Huang free_page((unsigned long)pae_root); 3800cb0f722aSWei Huang return -ENOMEM; 3801cb0f722aSWei Huang #endif 3802c50d8ae3SPaolo Bonzini } 3803c50d8ae3SPaolo Bonzini 3804264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3805264d3dc1SLai Jiangshan { 3806264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3807264d3dc1SLai Jiangshan 380861b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 380961b05a9fSLai Jiangshan return false; 381061b05a9fSLai Jiangshan 3811264d3dc1SLai Jiangshan /* 3812264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3813264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3814264d3dc1SLai Jiangshan * 3815264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3816264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3817264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3818264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3819264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3820264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3821264d3dc1SLai Jiangshan * requirement isn't satisfied. 3822264d3dc1SLai Jiangshan */ 3823264d3dc1SLai Jiangshan smp_rmb(); 3824264d3dc1SLai Jiangshan sp = to_shadow_page(root); 38255d6a3221SSean Christopherson 38265d6a3221SSean Christopherson /* 38275d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 38285d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 38295d6a3221SSean Christopherson */ 38305d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 38315d6a3221SSean Christopherson return false; 38325d6a3221SSean Christopherson 3833264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3834264d3dc1SLai Jiangshan return true; 3835264d3dc1SLai Jiangshan 3836264d3dc1SLai Jiangshan return false; 3837264d3dc1SLai Jiangshan } 3838264d3dc1SLai Jiangshan 3839c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3840c50d8ae3SPaolo Bonzini { 3841c50d8ae3SPaolo Bonzini int i; 3842c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3843c50d8ae3SPaolo Bonzini 3844347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3845c50d8ae3SPaolo Bonzini return; 3846c50d8ae3SPaolo Bonzini 3847b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3848c50d8ae3SPaolo Bonzini return; 3849c50d8ae3SPaolo Bonzini 3850c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3851c50d8ae3SPaolo Bonzini 38524d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3853b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3854e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3855c50d8ae3SPaolo Bonzini 3856264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3857c50d8ae3SPaolo Bonzini return; 3858c50d8ae3SPaolo Bonzini 3859531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 386065855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3861531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3862c50d8ae3SPaolo Bonzini return; 3863c50d8ae3SPaolo Bonzini } 3864c50d8ae3SPaolo Bonzini 3865531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3866c50d8ae3SPaolo Bonzini 3867c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3868c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3869c50d8ae3SPaolo Bonzini 3870c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 38712ca3129eSSean Christopherson root &= SPTE_BASE_ADDR_MASK; 3872e47c4aeeSSean Christopherson sp = to_shadow_page(root); 387365855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3874c50d8ae3SPaolo Bonzini } 3875c50d8ae3SPaolo Bonzini } 3876c50d8ae3SPaolo Bonzini 3877531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3878c50d8ae3SPaolo Bonzini } 3879c50d8ae3SPaolo Bonzini 388061b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 388161b05a9fSLai Jiangshan { 388261b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 388361b05a9fSLai Jiangshan int i; 388461b05a9fSLai Jiangshan 388561b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 388661b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 388761b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 388861b05a9fSLai Jiangshan 388961b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 38900c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 389161b05a9fSLai Jiangshan } 389261b05a9fSLai Jiangshan 38931f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 38945b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3895c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3896c50d8ae3SPaolo Bonzini { 3897c50d8ae3SPaolo Bonzini if (exception) 3898c50d8ae3SPaolo Bonzini exception->error_code = 0; 3899c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3900c50d8ae3SPaolo Bonzini } 3901c50d8ae3SPaolo Bonzini 3902c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3903c50d8ae3SPaolo Bonzini { 3904c50d8ae3SPaolo Bonzini /* 3905c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3906c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3907c50d8ae3SPaolo Bonzini */ 3908c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3909c50d8ae3SPaolo Bonzini return false; 3910c50d8ae3SPaolo Bonzini 3911c50d8ae3SPaolo Bonzini if (direct) 3912c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3913c50d8ae3SPaolo Bonzini 3914c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3915c50d8ae3SPaolo Bonzini } 3916c50d8ae3SPaolo Bonzini 391795fb5b02SBen Gardon /* 391895fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 391995fb5b02SBen Gardon * That SPTE may be non-present. 3920c5c8c7c5SDavid Matlack * 3921c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 392295fb5b02SBen Gardon */ 392339b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3924c50d8ae3SPaolo Bonzini { 3925c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 39262aa07893SSean Christopherson int leaf = -1; 392795fb5b02SBen Gardon u64 spte; 3928c50d8ae3SPaolo Bonzini 392939b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 393039b4d43eSSean Christopherson *root_level = iterator.level; 3931c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3932c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 393395fb5b02SBen Gardon leaf = iterator.level; 3934c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3935c50d8ae3SPaolo Bonzini 3936dde81f94SSean Christopherson sptes[leaf] = spte; 393795fb5b02SBen Gardon } 393895fb5b02SBen Gardon 393995fb5b02SBen Gardon return leaf; 394095fb5b02SBen Gardon } 394195fb5b02SBen Gardon 39429aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 394395fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 394495fb5b02SBen Gardon { 3945dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 394695fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 394739b4d43eSSean Christopherson int root, leaf, level; 394895fb5b02SBen Gardon bool reserved = false; 394995fb5b02SBen Gardon 3950c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3951c5c8c7c5SDavid Matlack 395263c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 395339b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 395495fb5b02SBen Gardon else 395539b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 395695fb5b02SBen Gardon 3957c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 3958c5c8c7c5SDavid Matlack 39592aa07893SSean Christopherson if (unlikely(leaf < 0)) { 39602aa07893SSean Christopherson *sptep = 0ull; 39612aa07893SSean Christopherson return reserved; 39622aa07893SSean Christopherson } 39632aa07893SSean Christopherson 39649aa41879SSean Christopherson *sptep = sptes[leaf]; 39659aa41879SSean Christopherson 39669aa41879SSean Christopherson /* 39679aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 39689aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 39699aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 39709aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 39719aa41879SSean Christopherson */ 39729aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 39739aa41879SSean Christopherson leaf++; 397495fb5b02SBen Gardon 397595fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 397695fb5b02SBen Gardon 39779aa41879SSean Christopherson for (level = root; level >= leaf; level--) 3978961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 3979c50d8ae3SPaolo Bonzini 3980c50d8ae3SPaolo Bonzini if (reserved) { 3981bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 3982c50d8ae3SPaolo Bonzini __func__, addr); 398395fb5b02SBen Gardon for (level = root; level >= leaf; level--) 3984bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 3985bb4cdf3aSSean Christopherson sptes[level], level, 3986961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 3987c50d8ae3SPaolo Bonzini } 3988ddce6208SSean Christopherson 3989c50d8ae3SPaolo Bonzini return reserved; 3990c50d8ae3SPaolo Bonzini } 3991c50d8ae3SPaolo Bonzini 3992c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3993c50d8ae3SPaolo Bonzini { 3994c50d8ae3SPaolo Bonzini u64 spte; 3995c50d8ae3SPaolo Bonzini bool reserved; 3996c50d8ae3SPaolo Bonzini 3997c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 3998c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3999c50d8ae3SPaolo Bonzini 400095fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 4001c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 4002c50d8ae3SPaolo Bonzini return -EINVAL; 4003c50d8ae3SPaolo Bonzini 4004c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4005c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 40060a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4007c50d8ae3SPaolo Bonzini 4008c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4009c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4010c50d8ae3SPaolo Bonzini 4011c50d8ae3SPaolo Bonzini if (direct) 4012c50d8ae3SPaolo Bonzini addr = 0; 4013c50d8ae3SPaolo Bonzini 4014c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4015c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4016c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4017c50d8ae3SPaolo Bonzini } 4018c50d8ae3SPaolo Bonzini 4019c50d8ae3SPaolo Bonzini /* 4020c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4021c50d8ae3SPaolo Bonzini * the address. 4022c50d8ae3SPaolo Bonzini */ 4023c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4024c50d8ae3SPaolo Bonzini } 4025c50d8ae3SPaolo Bonzini 4026c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4027b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4028c50d8ae3SPaolo Bonzini { 4029b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4030c50d8ae3SPaolo Bonzini return false; 4031c50d8ae3SPaolo Bonzini 4032b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4033c50d8ae3SPaolo Bonzini return false; 4034c50d8ae3SPaolo Bonzini 4035c50d8ae3SPaolo Bonzini /* 4036c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4037c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4038c50d8ae3SPaolo Bonzini */ 40399d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 4040c50d8ae3SPaolo Bonzini return true; 4041c50d8ae3SPaolo Bonzini 4042c50d8ae3SPaolo Bonzini return false; 4043c50d8ae3SPaolo Bonzini } 4044c50d8ae3SPaolo Bonzini 4045c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4046c50d8ae3SPaolo Bonzini { 4047c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4048c50d8ae3SPaolo Bonzini u64 spte; 4049c50d8ae3SPaolo Bonzini 4050c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 40513e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4052c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4053c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4054c50d8ae3SPaolo Bonzini } 4055c50d8ae3SPaolo Bonzini 40566f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 40576f3c1fc5SLiang Zhang { 40586f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 40596f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 40606f3c1fc5SLiang Zhang 40616f3c1fc5SLiang Zhang if (id << 12 == 0) 40626f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 40636f3c1fc5SLiang Zhang 40646f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 40656f3c1fc5SLiang Zhang } 40666f3c1fc5SLiang Zhang 4067e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 40689f1a8526SSean Christopherson gfn_t gfn) 4069c50d8ae3SPaolo Bonzini { 4070c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4071c50d8ae3SPaolo Bonzini 40726f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4073c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4074347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 4075d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 4076c50d8ae3SPaolo Bonzini 40779f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 40789f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4079c50d8ae3SPaolo Bonzini } 4080c50d8ae3SPaolo Bonzini 40818a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 40828a009d5bSSean Christopherson { 40838a009d5bSSean Christopherson int r; 40848a009d5bSSean Christopherson 40858a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 40868a009d5bSSean Christopherson work->wakeup_all) 40878a009d5bSSean Christopherson return; 40888a009d5bSSean Christopherson 40898a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 40908a009d5bSSean Christopherson if (unlikely(r)) 40918a009d5bSSean Christopherson return; 40928a009d5bSSean Christopherson 40938a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 40948a009d5bSSean Christopherson work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu)) 40958a009d5bSSean Christopherson return; 40968a009d5bSSean Christopherson 40978a009d5bSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true); 40988a009d5bSSean Christopherson } 40998a009d5bSSean Christopherson 41005276c616SSean Christopherson static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4101c50d8ae3SPaolo Bonzini { 4102e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4103c50d8ae3SPaolo Bonzini bool async; 4104c50d8ae3SPaolo Bonzini 4105e0c37868SSean Christopherson /* 4106e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4107e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4108e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4109e0c37868SSean Christopherson */ 4110e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 41115276c616SSean Christopherson return RET_PF_RETRY; 4112e0c37868SSean Christopherson 41139cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4114c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 41159cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4116e710c5f6SDavid Matlack fault->slot = NULL; 41173647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 41183647cd04SPaolo Bonzini fault->map_writable = false; 41195276c616SSean Christopherson return RET_PF_CONTINUE; 4120c50d8ae3SPaolo Bonzini } 41219cc13d60SMaxim Levitsky /* 41229cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 41239cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 41249cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 41259cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 41269cc13d60SMaxim Levitsky */ 41279cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 41285276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 41295276c616SSean Christopherson return RET_PF_EMULATE; 41309cc13d60SMaxim Levitsky } 4131c50d8ae3SPaolo Bonzini 4132c50d8ae3SPaolo Bonzini async = false; 41333647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, 41343647cd04SPaolo Bonzini fault->write, &fault->map_writable, 41353647cd04SPaolo Bonzini &fault->hva); 4136c50d8ae3SPaolo Bonzini if (!async) 41375276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4138c50d8ae3SPaolo Bonzini 41392839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 41403647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 41413647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 41423647cd04SPaolo Bonzini trace_kvm_async_pf_doublefault(fault->addr, fault->gfn); 4143c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 41445276c616SSean Christopherson return RET_PF_RETRY; 41455276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 41465276c616SSean Christopherson return RET_PF_RETRY; 41475276c616SSean Christopherson } 4148c50d8ae3SPaolo Bonzini } 4149c50d8ae3SPaolo Bonzini 41503647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, 41513647cd04SPaolo Bonzini fault->write, &fault->map_writable, 41523647cd04SPaolo Bonzini &fault->hva); 41535276c616SSean Christopherson return RET_PF_CONTINUE; 4154c50d8ae3SPaolo Bonzini } 4155c50d8ae3SPaolo Bonzini 4156a955cad8SSean Christopherson /* 4157a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4158a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4159a955cad8SSean Christopherson */ 4160a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4161a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 4162a955cad8SSean Christopherson { 4163b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 416418c841e1SSean Christopherson 416518c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 416618c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 416718c841e1SSean Christopherson return true; 416818c841e1SSean Christopherson 416918c841e1SSean Christopherson /* 417018c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 417118c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 417218c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 417318c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 417418c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 417518c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 417618c841e1SSean Christopherson */ 4177527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4178a955cad8SSean Christopherson return true; 4179a955cad8SSean Christopherson 4180a955cad8SSean Christopherson return fault->slot && 4181a955cad8SSean Christopherson mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4182a955cad8SSean Christopherson } 4183a955cad8SSean Christopherson 41844326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4185c50d8ae3SPaolo Bonzini { 418663c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4187c50d8ae3SPaolo Bonzini 41880f90e1c1SSean Christopherson unsigned long mmu_seq; 418983f06fa7SSean Christopherson int r; 4190c50d8ae3SPaolo Bonzini 41913c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4192e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4193e710c5f6SDavid Matlack 4194b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4195c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4196c50d8ae3SPaolo Bonzini 41973c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4198c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4199c4371c2aSSean Christopherson return r; 420083291445SSean Christopherson 4201378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4202c50d8ae3SPaolo Bonzini if (r) 4203c50d8ae3SPaolo Bonzini return r; 4204c50d8ae3SPaolo Bonzini 4205367fd790SSean Christopherson mmu_seq = vcpu->kvm->mmu_notifier_seq; 4206367fd790SSean Christopherson smp_rmb(); 4207367fd790SSean Christopherson 42085276c616SSean Christopherson r = kvm_faultin_pfn(vcpu, fault); 42095276c616SSean Christopherson if (r != RET_PF_CONTINUE) 42108f32d5e5SMaxim Levitsky return r; 4211367fd790SSean Christopherson 42125276c616SSean Christopherson r = handle_abnormal_pfn(vcpu, fault, ACC_ALL); 42135276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4214367fd790SSean Christopherson return r; 4215367fd790SSean Christopherson 4216367fd790SSean Christopherson r = RET_PF_RETRY; 4217a2855afcSBen Gardon 42180b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4219a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4220a2855afcSBen Gardon else 4221531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4222a2855afcSBen Gardon 4223a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4224367fd790SSean Christopherson goto out_unlock; 4225a955cad8SSean Christopherson 42267bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 42277bd7ded6SSean Christopherson if (r) 4228367fd790SSean Christopherson goto out_unlock; 4229bb18842eSBen Gardon 42300b873fd7SDavid Matlack if (is_tdp_mmu_fault) 42312f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4232bb18842eSBen Gardon else 423343b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 42340f90e1c1SSean Christopherson 4235367fd790SSean Christopherson out_unlock: 42360b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4237a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4238a2855afcSBen Gardon else 4239531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 42403647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4241367fd790SSean Christopherson return r; 4242c50d8ae3SPaolo Bonzini } 4243c50d8ae3SPaolo Bonzini 4244c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4245c501040aSPaolo Bonzini struct kvm_page_fault *fault) 42460f90e1c1SSean Christopherson { 42474326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 42480f90e1c1SSean Christopherson 42490f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 42504326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 42514326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 42520f90e1c1SSean Christopherson } 42530f90e1c1SSean Christopherson 4254c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4255c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4256c50d8ae3SPaolo Bonzini { 4257c50d8ae3SPaolo Bonzini int r = 1; 42589ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4259c50d8ae3SPaolo Bonzini 4260736c291cSSean Christopherson #ifndef CONFIG_X86_64 4261736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4262736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4263736c291cSSean Christopherson return -EFAULT; 4264736c291cSSean Christopherson #endif 4265736c291cSSean Christopherson 4266c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 42679ce372b3SVitaly Kuznetsov if (!flags) { 4268c50d8ae3SPaolo Bonzini trace_kvm_page_fault(fault_address, error_code); 4269c50d8ae3SPaolo Bonzini 4270c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4271c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4272c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4273c50d8ae3SPaolo Bonzini insn_len); 42749ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 427568fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4276c50d8ae3SPaolo Bonzini local_irq_disable(); 42776bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4278c50d8ae3SPaolo Bonzini local_irq_enable(); 42799ce372b3SVitaly Kuznetsov } else { 42809ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4281c50d8ae3SPaolo Bonzini } 42829ce372b3SVitaly Kuznetsov 4283c50d8ae3SPaolo Bonzini return r; 4284c50d8ae3SPaolo Bonzini } 4285c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4286c50d8ae3SPaolo Bonzini 4287c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4288c50d8ae3SPaolo Bonzini { 42894326e57eSPaolo Bonzini while (fault->max_level > PG_LEVEL_4K) { 42904326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 42914326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4292c50d8ae3SPaolo Bonzini 4293cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4294cb9b88c6SSean Christopherson break; 42954326e57eSPaolo Bonzini 42964326e57eSPaolo Bonzini --fault->max_level; 4297c50d8ae3SPaolo Bonzini } 4298c50d8ae3SPaolo Bonzini 42994326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4300c50d8ae3SPaolo Bonzini } 4301c50d8ae3SPaolo Bonzini 430284a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4303c50d8ae3SPaolo Bonzini { 4304c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4305c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4306c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 43075efac074SPaolo Bonzini context->invlpg = NULL; 4308c50d8ae3SPaolo Bonzini } 4309c50d8ae3SPaolo Bonzini 4310be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 43110be44352SSean Christopherson union kvm_mmu_page_role role) 43120be44352SSean Christopherson { 4313be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 43145499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4315e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 43160be44352SSean Christopherson } 43170be44352SSean Christopherson 4318c50d8ae3SPaolo Bonzini /* 43195499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 43205499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 43215499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 43225499ea73SPaolo Bonzini * true is returned. 43235499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 43245499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4325c50d8ae3SPaolo Bonzini */ 43265499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 43275499ea73SPaolo Bonzini gpa_t new_pgd, 4328c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4329c50d8ae3SPaolo Bonzini { 4330c50d8ae3SPaolo Bonzini uint i; 4331c50d8ae3SPaolo Bonzini 4332b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 43330be44352SSean Christopherson return true; 43340be44352SSean Christopherson 4335c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 43365499ea73SPaolo Bonzini /* 43375499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 43385499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 43395499ea73SPaolo Bonzini * 0 C 1 2 3 43405499ea73SPaolo Bonzini * 1 C 0 2 3 43415499ea73SPaolo Bonzini * 2 C 0 1 3 43425499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 43435499ea73SPaolo Bonzini */ 4344b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4345b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 43465499ea73SPaolo Bonzini return true; 4347c50d8ae3SPaolo Bonzini } 4348c50d8ae3SPaolo Bonzini 43495499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 43505499ea73SPaolo Bonzini return false; 4351c50d8ae3SPaolo Bonzini } 4352c50d8ae3SPaolo Bonzini 4353c50d8ae3SPaolo Bonzini /* 43545499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 43555499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 43565499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 43575499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 43585499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 43595499ea73SPaolo Bonzini */ 43605499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 43615499ea73SPaolo Bonzini gpa_t new_pgd, 43625499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 43635499ea73SPaolo Bonzini { 43645499ea73SPaolo Bonzini uint i; 43655499ea73SPaolo Bonzini 43665499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 43675499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 43685499ea73SPaolo Bonzini goto hit; 43695499ea73SPaolo Bonzini 43705499ea73SPaolo Bonzini return false; 43715499ea73SPaolo Bonzini 43725499ea73SPaolo Bonzini hit: 43735499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 43745499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 43755499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 43765499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 43775499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 43785499ea73SPaolo Bonzini return true; 43795499ea73SPaolo Bonzini } 43805499ea73SPaolo Bonzini 43815499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 43825499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 43835499ea73SPaolo Bonzini { 43845499ea73SPaolo Bonzini /* 43855499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4386c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4387c50d8ae3SPaolo Bonzini * later if necessary. 4388c50d8ae3SPaolo Bonzini */ 43895499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 43905499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4391c50d8ae3SPaolo Bonzini 43925499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 43935499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 43945499ea73SPaolo Bonzini else 43955499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4396c50d8ae3SPaolo Bonzini } 4397c50d8ae3SPaolo Bonzini 4398d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4399c50d8ae3SPaolo Bonzini { 44000c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 44017a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 44020c1c92f1SPaolo Bonzini 44035499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 44045499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4405b869855bSSean Christopherson return; 4406c50d8ae3SPaolo Bonzini } 4407c50d8ae3SPaolo Bonzini 4408c50d8ae3SPaolo Bonzini /* 4409b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4410b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4411527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4412527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4413b869855bSSean Christopherson */ 4414b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4415b869855bSSean Christopherson 4416b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4417b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4418b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4419b5129100SSean Christopherson } 4420b869855bSSean Christopherson 4421b869855bSSean Christopherson /* 4422b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4423b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4424b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4425b869855bSSean Christopherson * the shadow page tables. 4426c50d8ae3SPaolo Bonzini */ 4427c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4428c50d8ae3SPaolo Bonzini 4429daa5b6c1SBen Gardon /* 4430daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4431daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4432daa5b6c1SBen Gardon */ 4433daa5b6c1SBen Gardon if (!new_role.direct) 4434daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4435b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4436c50d8ae3SPaolo Bonzini } 4437be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4438c50d8ae3SPaolo Bonzini 4439c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4440c50d8ae3SPaolo Bonzini { 4441c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4442c50d8ae3SPaolo Bonzini } 4443c50d8ae3SPaolo Bonzini 4444c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4445c3e5e415SLai Jiangshan unsigned int access) 4446c50d8ae3SPaolo Bonzini { 4447c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4448c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4449c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4450c50d8ae3SPaolo Bonzini return true; 4451c50d8ae3SPaolo Bonzini } 4452c50d8ae3SPaolo Bonzini 4453c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4454c50d8ae3SPaolo Bonzini return true; 4455c50d8ae3SPaolo Bonzini } 4456c50d8ae3SPaolo Bonzini 4457c50d8ae3SPaolo Bonzini return false; 4458c50d8ae3SPaolo Bonzini } 4459c50d8ae3SPaolo Bonzini 4460c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4461c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4462c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4463c50d8ae3SPaolo Bonzini #undef PTTYPE 4464c50d8ae3SPaolo Bonzini 4465c50d8ae3SPaolo Bonzini #define PTTYPE 64 4466c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4467c50d8ae3SPaolo Bonzini #undef PTTYPE 4468c50d8ae3SPaolo Bonzini 4469c50d8ae3SPaolo Bonzini #define PTTYPE 32 4470c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4471c50d8ae3SPaolo Bonzini #undef PTTYPE 4472c50d8ae3SPaolo Bonzini 4473c50d8ae3SPaolo Bonzini static void 4474b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 44755b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4476c50d8ae3SPaolo Bonzini bool pse, bool amd) 4477c50d8ae3SPaolo Bonzini { 4478c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4479c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 44805b7f575cSSean Christopherson u64 high_bits_rsvd; 4481c50d8ae3SPaolo Bonzini 4482c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4483c50d8ae3SPaolo Bonzini 4484c50d8ae3SPaolo Bonzini if (!gbpages) 4485c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4486c50d8ae3SPaolo Bonzini 44875b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 44885b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 44895b7f575cSSean Christopherson else 44905b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 44915b7f575cSSean Christopherson 44925b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 44935b7f575cSSean Christopherson if (!nx) 44945b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 44955b7f575cSSean Christopherson 4496c50d8ae3SPaolo Bonzini /* 4497c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4498c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4499c50d8ae3SPaolo Bonzini */ 4500c50d8ae3SPaolo Bonzini if (amd) 4501c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4502c50d8ae3SPaolo Bonzini 4503c50d8ae3SPaolo Bonzini switch (level) { 4504c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4505c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4506c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4507c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4508c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4509c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4510c50d8ae3SPaolo Bonzini 4511c50d8ae3SPaolo Bonzini if (!pse) { 4512c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4513c50d8ae3SPaolo Bonzini break; 4514c50d8ae3SPaolo Bonzini } 4515c50d8ae3SPaolo Bonzini 4516c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4517c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4518c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4519c50d8ae3SPaolo Bonzini else 4520c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4521c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4522c50d8ae3SPaolo Bonzini break; 4523c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 45245b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 45255b7f575cSSean Christopherson high_bits_rsvd | 45265b7f575cSSean Christopherson rsvd_bits(5, 8) | 45275b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 45285b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 45295b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 45305b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4531c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4532c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4533c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4534c50d8ae3SPaolo Bonzini break; 4535c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 45365b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 45375b7f575cSSean Christopherson nonleaf_bit8_rsvd | 45385b7f575cSSean Christopherson rsvd_bits(7, 7); 4539c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4540c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4541df561f66SGustavo A. R. Silva fallthrough; 4542c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 45435b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 45445b7f575cSSean Christopherson nonleaf_bit8_rsvd | 45455b7f575cSSean Christopherson rsvd_bits(7, 7); 45465b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 45475b7f575cSSean Christopherson gbpages_bit_rsvd; 45485b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 45495b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4550c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4551c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 45525b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 45535b7f575cSSean Christopherson gbpages_bit_rsvd | 4554c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 45555b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4556c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4557c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4558c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4559c50d8ae3SPaolo Bonzini break; 4560c50d8ae3SPaolo Bonzini } 4561c50d8ae3SPaolo Bonzini } 4562c50d8ae3SPaolo Bonzini 456327de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 456427de9250SSean Christopherson { 456527de9250SSean Christopherson /* 456627de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 456727de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 456827de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 456927de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 457027de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 457127de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 457227de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 457327de9250SSean Christopherson */ 457427de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 457527de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 457627de9250SSean Christopherson } 457727de9250SSean Christopherson 4578c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4579c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4580c50d8ae3SPaolo Bonzini { 4581b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 45825b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 45834d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 458427de9250SSean Christopherson guest_can_use_gbpages(vcpu), 45854e9c0d80SSean Christopherson is_cr4_pse(context), 458623493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4587c50d8ae3SPaolo Bonzini } 4588c50d8ae3SPaolo Bonzini 4589c50d8ae3SPaolo Bonzini static void 4590c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 459184ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4592c50d8ae3SPaolo Bonzini { 45935b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 459484ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4595c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4596c50d8ae3SPaolo Bonzini 459784ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 459884ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 459984ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 460084ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 460184ea5c09SLai Jiangshan 46025b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 46035b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 460484ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 460584ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 46065b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4607c50d8ae3SPaolo Bonzini 4608c50d8ae3SPaolo Bonzini /* large page */ 4609c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4610c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 461184ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 461284ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4613c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4614c50d8ae3SPaolo Bonzini 4615c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4616c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4617c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4618c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4619c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4620c50d8ae3SPaolo Bonzini if (!execonly) { 4621c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4622c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4623c50d8ae3SPaolo Bonzini } 4624c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4625c50d8ae3SPaolo Bonzini } 4626c50d8ae3SPaolo Bonzini 4627c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 462884ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4629c50d8ae3SPaolo Bonzini { 4630c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 463184ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 463284ea5c09SLai Jiangshan huge_page_level); 4633c50d8ae3SPaolo Bonzini } 4634c50d8ae3SPaolo Bonzini 46356f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 46366f8e65a6SSean Christopherson { 46376f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 46386f8e65a6SSean Christopherson } 46396f8e65a6SSean Christopherson 4640c50d8ae3SPaolo Bonzini /* 4641c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4642c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4643c50d8ae3SPaolo Bonzini * follow the features in guest. 4644c50d8ae3SPaolo Bonzini */ 464516be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 464616be1d12SSean Christopherson struct kvm_mmu *context) 4647c50d8ae3SPaolo Bonzini { 46488c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 46498c985b2dSSean Christopherson bool is_amd = true; 46508c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 46518c985b2dSSean Christopherson bool is_pse = false; 4652c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4653c50d8ae3SPaolo Bonzini int i; 4654c50d8ae3SPaolo Bonzini 4655a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 46568c985b2dSSean Christopherson 4657c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4658b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4659a972e29cSPaolo Bonzini context->root_role.level, 46607a458f0eSPaolo Bonzini context->root_role.efer_nx, 466127de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4662c50d8ae3SPaolo Bonzini 4663c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4664c50d8ae3SPaolo Bonzini return; 4665c50d8ae3SPaolo Bonzini 4666a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4667e54f1ff2SKai Huang /* 4668e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4669e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4670e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4671e54f1ff2SKai Huang * not allowed to be set. 4672e54f1ff2SKai Huang */ 4673e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4674e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4675e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4676e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4677c50d8ae3SPaolo Bonzini } 4678c50d8ae3SPaolo Bonzini 4679c50d8ae3SPaolo Bonzini } 4680c50d8ae3SPaolo Bonzini 4681c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4682c50d8ae3SPaolo Bonzini { 4683c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4684c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4685c50d8ae3SPaolo Bonzini } 4686c50d8ae3SPaolo Bonzini 4687c50d8ae3SPaolo Bonzini /* 4688c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4689c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4690c50d8ae3SPaolo Bonzini */ 4691c50d8ae3SPaolo Bonzini static void 4692e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4693c50d8ae3SPaolo Bonzini { 4694c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4695c50d8ae3SPaolo Bonzini int i; 4696c50d8ae3SPaolo Bonzini 4697c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4698c50d8ae3SPaolo Bonzini 4699c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4700b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4701a972e29cSPaolo Bonzini context->root_role.level, false, 4702c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 47038c985b2dSSean Christopherson false, true); 4704c50d8ae3SPaolo Bonzini else 4705c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 470684ea5c09SLai Jiangshan reserved_hpa_bits(), false, 470784ea5c09SLai Jiangshan max_huge_page_level); 4708c50d8ae3SPaolo Bonzini 4709c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4710c50d8ae3SPaolo Bonzini return; 4711c50d8ae3SPaolo Bonzini 4712a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4713c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4714c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4715c50d8ae3SPaolo Bonzini } 4716c50d8ae3SPaolo Bonzini } 4717c50d8ae3SPaolo Bonzini 4718c50d8ae3SPaolo Bonzini /* 4719c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4720c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4721c50d8ae3SPaolo Bonzini */ 4722c50d8ae3SPaolo Bonzini static void 4723e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4724c50d8ae3SPaolo Bonzini { 4725c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 472684ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 472784ea5c09SLai Jiangshan max_huge_page_level); 4728c50d8ae3SPaolo Bonzini } 4729c50d8ae3SPaolo Bonzini 4730c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4731c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4732c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4733c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4734c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4735c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4736c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4737c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4738c50d8ae3SPaolo Bonzini 4739c50d8ae3SPaolo Bonzini 4740c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4741c50d8ae3SPaolo Bonzini { 4742c50d8ae3SPaolo Bonzini unsigned byte; 4743c50d8ae3SPaolo Bonzini 4744c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4745c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4746c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4747c50d8ae3SPaolo Bonzini 4748c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4749c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4750c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 475190599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4752c50d8ae3SPaolo Bonzini 4753c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4754c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4755c50d8ae3SPaolo Bonzini 4756c50d8ae3SPaolo Bonzini /* 4757c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4758c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4759c50d8ae3SPaolo Bonzini */ 4760c50d8ae3SPaolo Bonzini 4761c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4762c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4763c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4764c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4765c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4766c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4767c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4768c50d8ae3SPaolo Bonzini u8 smepf = 0; 4769c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4770c50d8ae3SPaolo Bonzini u8 smapf = 0; 4771c50d8ae3SPaolo Bonzini 4772c50d8ae3SPaolo Bonzini if (!ept) { 4773c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4774c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4775c50d8ae3SPaolo Bonzini 4776c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 477790599c28SSean Christopherson if (!efer_nx) 4778c50d8ae3SPaolo Bonzini ff = 0; 4779c50d8ae3SPaolo Bonzini 4780c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4781c50d8ae3SPaolo Bonzini if (!cr0_wp) 4782c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4783c50d8ae3SPaolo Bonzini 4784c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4785c50d8ae3SPaolo Bonzini if (cr4_smep) 4786c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4787c50d8ae3SPaolo Bonzini 4788c50d8ae3SPaolo Bonzini /* 4789c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4790c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4791c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4792c50d8ae3SPaolo Bonzini * conditions are true: 4793c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4794c50d8ae3SPaolo Bonzini * - A user page is accessed 4795c50d8ae3SPaolo Bonzini * - The access is not a fetch 47964f4aa80eSLai Jiangshan * - The access is supervisor mode 47974f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4798c50d8ae3SPaolo Bonzini * 479994b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 480094b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4801c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4802c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4803c50d8ae3SPaolo Bonzini */ 4804c50d8ae3SPaolo Bonzini if (cr4_smap) 4805c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4806c50d8ae3SPaolo Bonzini } 4807c50d8ae3SPaolo Bonzini 4808c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4809c50d8ae3SPaolo Bonzini } 4810c50d8ae3SPaolo Bonzini } 4811c50d8ae3SPaolo Bonzini 4812c50d8ae3SPaolo Bonzini /* 4813c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4814c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4815c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4816c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4817c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4818c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4819c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4820c50d8ae3SPaolo Bonzini * 4821c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4822c50d8ae3SPaolo Bonzini * page tables and the machine state: 4823c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4824c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4825c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4826c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4827c50d8ae3SPaolo Bonzini * 4828c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4829c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4830c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4831c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4832c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4833c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4834c50d8ae3SPaolo Bonzini * only will be masked away. 4835c50d8ae3SPaolo Bonzini */ 48362e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4837c50d8ae3SPaolo Bonzini { 4838c50d8ae3SPaolo Bonzini unsigned bit; 4839c50d8ae3SPaolo Bonzini bool wp; 4840c50d8ae3SPaolo Bonzini 4841c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4842a3ca5281SChenyi Qiang 4843a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4844c50d8ae3SPaolo Bonzini return; 4845c50d8ae3SPaolo Bonzini 48462e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4847c50d8ae3SPaolo Bonzini 4848c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4849c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4850c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4851c50d8ae3SPaolo Bonzini 4852c50d8ae3SPaolo Bonzini pfec = bit << 1; 4853c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4854c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4855c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4856c50d8ae3SPaolo Bonzini 4857c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4858c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4859c50d8ae3SPaolo Bonzini 4860c50d8ae3SPaolo Bonzini /* 4861c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4862c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4863c50d8ae3SPaolo Bonzini */ 4864c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4865c50d8ae3SPaolo Bonzini /* 4866c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4867c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4868c50d8ae3SPaolo Bonzini */ 4869c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4870c50d8ae3SPaolo Bonzini 4871c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4872c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4873c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4874c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4875c50d8ae3SPaolo Bonzini 4876c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4877c50d8ae3SPaolo Bonzini } 4878c50d8ae3SPaolo Bonzini } 4879c50d8ae3SPaolo Bonzini 4880533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4881533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4882c50d8ae3SPaolo Bonzini { 4883533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4884533f9a4bSSean Christopherson return; 4885c50d8ae3SPaolo Bonzini 4886c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 4887533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4888533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4889c50d8ae3SPaolo Bonzini } 4890c50d8ae3SPaolo Bonzini 4891fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4892c50d8ae3SPaolo Bonzini { 4893c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4894c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4895c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4896c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4897c50d8ae3SPaolo Bonzini } 4898c50d8ae3SPaolo Bonzini 489984a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4900c50d8ae3SPaolo Bonzini { 4901c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4902c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4903c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4904c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4905c50d8ae3SPaolo Bonzini } 4906c50d8ae3SPaolo Bonzini 49077a7ae829SPaolo Bonzini static union kvm_cpu_role 4908e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 4909e5ed0fb0SPaolo Bonzini { 49107a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4911e5ed0fb0SPaolo Bonzini 4912e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 4913e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 4914e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4915e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 4916e5ed0fb0SPaolo Bonzini 4917e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 4918e5ed0fb0SPaolo Bonzini role.base.direct = 1; 4919e5ed0fb0SPaolo Bonzini return role; 4920e5ed0fb0SPaolo Bonzini } 4921e5ed0fb0SPaolo Bonzini 4922e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 4923e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 4924e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 4925e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 4926e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 492760f3cb60SPaolo Bonzini 492860f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 492960f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 493060f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 493160f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 493260f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 493360f3cb60SPaolo Bonzini else 493460f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 4935e5ed0fb0SPaolo Bonzini 4936e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 4937e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 4938e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 4939e5ed0fb0SPaolo Bonzini 4940e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 4941e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 4942e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 4943e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 4944e5ed0fb0SPaolo Bonzini return role; 4945e5ed0fb0SPaolo Bonzini } 4946e5ed0fb0SPaolo Bonzini 4947d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 4948d468d94bSSean Christopherson { 4949746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 4950746700d2SWei Huang if (tdp_root_level) 4951746700d2SWei Huang return tdp_root_level; 4952746700d2SWei Huang 4953d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 495483013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 4955d468d94bSSean Christopherson return 4; 4956d468d94bSSean Christopherson 495783013059SSean Christopherson return max_tdp_level; 4958d468d94bSSean Christopherson } 4959d468d94bSSean Christopherson 49607a458f0eSPaolo Bonzini static union kvm_mmu_page_role 49618626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 49627a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 4963c50d8ae3SPaolo Bonzini { 49647a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 4965c50d8ae3SPaolo Bonzini 49667a458f0eSPaolo Bonzini role.access = ACC_ALL; 49677a458f0eSPaolo Bonzini role.cr0_wp = true; 49687a458f0eSPaolo Bonzini role.efer_nx = true; 49697a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 49707a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 497154275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 49727a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 49737a458f0eSPaolo Bonzini role.direct = true; 49747a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 4975c50d8ae3SPaolo Bonzini 4976c50d8ae3SPaolo Bonzini return role; 4977c50d8ae3SPaolo Bonzini } 4978c50d8ae3SPaolo Bonzini 497939e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 4980a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 4981c50d8ae3SPaolo Bonzini { 49828c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 49837a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 4984c50d8ae3SPaolo Bonzini 4985e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 49867a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 4987c50d8ae3SPaolo Bonzini return; 4988c50d8ae3SPaolo Bonzini 4989e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 49907a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 49917a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 4992c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 49935efac074SPaolo Bonzini context->invlpg = NULL; 4994d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4995c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4996c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 4997c50d8ae3SPaolo Bonzini 499836f26787SSean Christopherson if (!is_cr0_pg(context)) 4999c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 500036f26787SSean Christopherson else if (is_cr4_pae(context)) 5001c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5002f4bd6f73SSean Christopherson else 5003c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5004c50d8ae3SPaolo Bonzini 5005533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5006e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5007c50d8ae3SPaolo Bonzini } 5008c50d8ae3SPaolo Bonzini 50098c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 50107a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 50117a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5012c50d8ae3SPaolo Bonzini { 5013e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 50147a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 501518db1b17SSean Christopherson return; 5016c50d8ae3SPaolo Bonzini 5017e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 50187a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 501918db1b17SSean Christopherson 502036f26787SSean Christopherson if (!is_cr0_pg(context)) 502184a16226SSean Christopherson nonpaging_init_context(context); 502236f26787SSean Christopherson else if (is_cr4_pae(context)) 5023fe660f72SSean Christopherson paging64_init_context(context); 5024c50d8ae3SPaolo Bonzini else 502584a16226SSean Christopherson paging32_init_context(context); 5026c50d8ae3SPaolo Bonzini 5027533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5028c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5029c50d8ae3SPaolo Bonzini } 50300f04a2acSVitaly Kuznetsov 5031594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5032a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 50330f04a2acSVitaly Kuznetsov { 50348c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 503556b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 503656b321f9SPaolo Bonzini 503756b321f9SPaolo Bonzini root_role = cpu_role.base; 503856b321f9SPaolo Bonzini 503956b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 504056b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 504156b321f9SPaolo Bonzini 504256b321f9SPaolo Bonzini /* 504356b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 504456b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 504556b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 504656b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 504756b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 504856b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 504956b321f9SPaolo Bonzini * MMU contexts. 505056b321f9SPaolo Bonzini */ 505156b321f9SPaolo Bonzini root_role.efer_nx = true; 50520f04a2acSVitaly Kuznetsov 50537a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 50540f04a2acSVitaly Kuznetsov } 50550f04a2acSVitaly Kuznetsov 5056dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5057dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 50580f04a2acSVitaly Kuznetsov { 50598c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5060594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5061594e91a1SSean Christopherson .cr0 = cr0, 506228f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5063594e91a1SSean Christopherson .efer = efer, 5064594e91a1SSean Christopherson }; 50657a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 506656b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 506756b321f9SPaolo Bonzini 506856b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 506956b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 507056b321f9SPaolo Bonzini 507156b321f9SPaolo Bonzini root_role = cpu_role.base; 507256b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 507384e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 507484e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 507584e5ffd0SLai Jiangshan root_role.passthrough = 1; 50760f04a2acSVitaly Kuznetsov 50777a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5078d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 50790f04a2acSVitaly Kuznetsov } 50800f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5081c50d8ae3SPaolo Bonzini 50827a7ae829SPaolo Bonzini static union kvm_cpu_role 5083c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5084bb1fcc70SSean Christopherson bool execonly, u8 level) 5085c50d8ae3SPaolo Bonzini { 50867a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5087c50d8ae3SPaolo Bonzini 5088daed87b8SPaolo Bonzini /* 5089daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5090daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5091daed87b8SPaolo Bonzini */ 5092daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5093bb1fcc70SSean Christopherson role.base.level = level; 5094bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5095c50d8ae3SPaolo Bonzini role.base.direct = false; 5096c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5097c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5098c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5099c50d8ae3SPaolo Bonzini 5100cd6767c3SSean Christopherson role.ext.word = 0; 5101c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5102cd6767c3SSean Christopherson role.ext.valid = 1; 5103c50d8ae3SPaolo Bonzini 5104c50d8ae3SPaolo Bonzini return role; 5105c50d8ae3SPaolo Bonzini } 5106c50d8ae3SPaolo Bonzini 5107c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5108cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5109cc022ae1SLai Jiangshan gpa_t new_eptp) 5110c50d8ae3SPaolo Bonzini { 51118c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5112bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 51137a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5114c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5115bb1fcc70SSean Christopherson execonly, level); 5116c50d8ae3SPaolo Bonzini 5117e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5118e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5119e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 51207a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 512118db1b17SSean Christopherson 5122c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5123c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5124c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 5125c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 5126347a0d0dSPaolo Bonzini 5127c596f147SSean Christopherson update_permission_bitmask(context, true); 512828f091bcSPaolo Bonzini context->pkru_mask = 0; 5129cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5130e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5131c50d8ae3SPaolo Bonzini } 51323cffc89dSPaolo Bonzini 5133d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 51343cffc89dSPaolo Bonzini } 5135c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5136c50d8ae3SPaolo Bonzini 513739e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5138a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5139c50d8ae3SPaolo Bonzini { 51408c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5141c50d8ae3SPaolo Bonzini 5142a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5143929d1cfaSPaolo Bonzini 5144d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5145c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5146c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5147c50d8ae3SPaolo Bonzini } 5148c50d8ae3SPaolo Bonzini 514939e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5150a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5151c50d8ae3SPaolo Bonzini { 5152c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5153c50d8ae3SPaolo Bonzini 5154e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5155c50d8ae3SPaolo Bonzini return; 5156c50d8ae3SPaolo Bonzini 5157e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5158d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5159c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5160c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5161c50d8ae3SPaolo Bonzini 5162c50d8ae3SPaolo Bonzini /* 51635efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 51645efac074SPaolo Bonzini * SPTEs. 51655efac074SPaolo Bonzini */ 51665efac074SPaolo Bonzini g_context->invlpg = NULL; 51675efac074SPaolo Bonzini 51685efac074SPaolo Bonzini /* 5169c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5170c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5171c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5172c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5173c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5174c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5175c50d8ae3SPaolo Bonzini */ 5176fa4b5588SSean Christopherson if (!is_paging(vcpu)) 51771f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5178fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 51791f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5180fa4b5588SSean Christopherson else if (is_pae(vcpu)) 51811f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5182fa4b5588SSean Christopherson else 51831f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5184fa4b5588SSean Christopherson 5185533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5186c50d8ae3SPaolo Bonzini } 5187c50d8ae3SPaolo Bonzini 5188c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5189c50d8ae3SPaolo Bonzini { 519039e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5191a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 519239e7e2bfSPaolo Bonzini 5193c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5194a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5195c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5196a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5197c50d8ae3SPaolo Bonzini else 5198a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5199c50d8ae3SPaolo Bonzini } 5200c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5201c50d8ae3SPaolo Bonzini 520249c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 520349c6f875SSean Christopherson { 520449c6f875SSean Christopherson /* 520549c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 520649c6f875SSean Christopherson * information is factored into reserved bit calculations. 5207feb627e8SVitaly Kuznetsov * 5208feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5209feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5210feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5211feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5212feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5213feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5214feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 521549c6f875SSean Christopherson */ 52167a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 52177a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 52187a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5219e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5220e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5221e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 522249c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 522363f5a190SSean Christopherson 522463f5a190SSean Christopherson /* 5225feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5226feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 522763f5a190SSean Christopherson */ 5228feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 522949c6f875SSean Christopherson } 523049c6f875SSean Christopherson 5231c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5232c50d8ae3SPaolo Bonzini { 5233c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5234c9060662SSean Christopherson kvm_init_mmu(vcpu); 5235c50d8ae3SPaolo Bonzini } 5236c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5237c50d8ae3SPaolo Bonzini 5238c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5239c50d8ae3SPaolo Bonzini { 5240c50d8ae3SPaolo Bonzini int r; 5241c50d8ae3SPaolo Bonzini 5242347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5243c50d8ae3SPaolo Bonzini if (r) 5244c50d8ae3SPaolo Bonzini goto out; 5245748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5246c50d8ae3SPaolo Bonzini if (r) 5247c50d8ae3SPaolo Bonzini goto out; 5248347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 52496e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 52506e6ec584SSean Christopherson else 52516e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5252c50d8ae3SPaolo Bonzini if (r) 5253c50d8ae3SPaolo Bonzini goto out; 5254a91f387bSSean Christopherson 5255a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5256a91f387bSSean Christopherson 5257727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5258db01416bSSean Christopherson 5259db01416bSSean Christopherson /* 5260db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5261db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5262db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5263db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5264db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5265db01416bSSean Christopherson */ 5266e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5267c50d8ae3SPaolo Bonzini out: 5268c50d8ae3SPaolo Bonzini return r; 5269c50d8ae3SPaolo Bonzini } 5270c50d8ae3SPaolo Bonzini 5271c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5272c50d8ae3SPaolo Bonzini { 52730c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 52740c1c92f1SPaolo Bonzini 52750c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5276b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 52770c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5278b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 52796d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5280c50d8ae3SPaolo Bonzini } 5281c50d8ae3SPaolo Bonzini 5282527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5283527d5cd7SSean Christopherson { 5284527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5285527d5cd7SSean Christopherson 5286527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5287527d5cd7SSean Christopherson return false; 5288527d5cd7SSean Christopherson 5289527d5cd7SSean Christopherson /* 5290527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5291527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5292527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5293527d5cd7SSean Christopherson * such false positives are relatively rare: 5294527d5cd7SSean Christopherson * 5295527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5296527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5297527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5298527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5299527d5cd7SSean Christopherson */ 5300527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5301527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5302527d5cd7SSean Christopherson } 5303527d5cd7SSean Christopherson 5304527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5305527d5cd7SSean Christopherson { 5306527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5307527d5cd7SSean Christopherson int i; 5308527d5cd7SSean Christopherson 5309527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5310527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5311527d5cd7SSean Christopherson 5312527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5313cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5314527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5315527d5cd7SSean Christopherson } 5316527d5cd7SSean Christopherson 5317527d5cd7SSean Christopherson if (roots_to_free) 5318527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5319527d5cd7SSean Christopherson } 5320527d5cd7SSean Christopherson 5321527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5322527d5cd7SSean Christopherson { 5323527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5324527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5325527d5cd7SSean Christopherson } 5326527d5cd7SSean Christopherson 5327c50d8ae3SPaolo Bonzini static bool need_remote_flush(u64 old, u64 new) 5328c50d8ae3SPaolo Bonzini { 5329c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old)) 5330c50d8ae3SPaolo Bonzini return false; 5331c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(new)) 5332c50d8ae3SPaolo Bonzini return true; 53332ca3129eSSean Christopherson if ((old ^ new) & SPTE_BASE_ADDR_MASK) 5334c50d8ae3SPaolo Bonzini return true; 5335c50d8ae3SPaolo Bonzini old ^= shadow_nx_mask; 5336c50d8ae3SPaolo Bonzini new ^= shadow_nx_mask; 53372ca3129eSSean Christopherson return (old & ~new & SPTE_PERM_MASK) != 0; 5338c50d8ae3SPaolo Bonzini } 5339c50d8ae3SPaolo Bonzini 5340c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5341c50d8ae3SPaolo Bonzini int *bytes) 5342c50d8ae3SPaolo Bonzini { 5343c50d8ae3SPaolo Bonzini u64 gentry = 0; 5344c50d8ae3SPaolo Bonzini int r; 5345c50d8ae3SPaolo Bonzini 5346c50d8ae3SPaolo Bonzini /* 5347c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5348c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5349c50d8ae3SPaolo Bonzini * when they have the same mode. 5350c50d8ae3SPaolo Bonzini */ 5351c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5352c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5353c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5354c50d8ae3SPaolo Bonzini *bytes = 8; 5355c50d8ae3SPaolo Bonzini } 5356c50d8ae3SPaolo Bonzini 5357c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5358c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5359c50d8ae3SPaolo Bonzini if (r) 5360c50d8ae3SPaolo Bonzini gentry = 0; 5361c50d8ae3SPaolo Bonzini } 5362c50d8ae3SPaolo Bonzini 5363c50d8ae3SPaolo Bonzini return gentry; 5364c50d8ae3SPaolo Bonzini } 5365c50d8ae3SPaolo Bonzini 5366c50d8ae3SPaolo Bonzini /* 5367c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5368c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5369c50d8ae3SPaolo Bonzini */ 5370c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5371c50d8ae3SPaolo Bonzini { 5372c50d8ae3SPaolo Bonzini /* 5373c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5374c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5375c50d8ae3SPaolo Bonzini */ 53763bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5377c50d8ae3SPaolo Bonzini return false; 5378c50d8ae3SPaolo Bonzini 5379c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5380c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5381c50d8ae3SPaolo Bonzini } 5382c50d8ae3SPaolo Bonzini 5383c50d8ae3SPaolo Bonzini /* 5384c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5385c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5386c50d8ae3SPaolo Bonzini */ 5387c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5388c50d8ae3SPaolo Bonzini int bytes) 5389c50d8ae3SPaolo Bonzini { 5390c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5391c50d8ae3SPaolo Bonzini 5392c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5393c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5394c50d8ae3SPaolo Bonzini 5395c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5396bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5397c50d8ae3SPaolo Bonzini 5398c50d8ae3SPaolo Bonzini /* 5399c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5400c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5401c50d8ae3SPaolo Bonzini */ 5402c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5403c50d8ae3SPaolo Bonzini return false; 5404c50d8ae3SPaolo Bonzini 5405c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5406c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5407c50d8ae3SPaolo Bonzini 5408c50d8ae3SPaolo Bonzini return misaligned; 5409c50d8ae3SPaolo Bonzini } 5410c50d8ae3SPaolo Bonzini 5411c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5412c50d8ae3SPaolo Bonzini { 5413c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5414c50d8ae3SPaolo Bonzini u64 *spte; 5415c50d8ae3SPaolo Bonzini int level; 5416c50d8ae3SPaolo Bonzini 5417c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5418c50d8ae3SPaolo Bonzini level = sp->role.level; 5419c50d8ae3SPaolo Bonzini *nspte = 1; 5420bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5421c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5422c50d8ae3SPaolo Bonzini /* 5423c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5424c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5425c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5426c50d8ae3SPaolo Bonzini */ 5427c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5428c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5429c50d8ae3SPaolo Bonzini page_offset <<= 1; 5430c50d8ae3SPaolo Bonzini *nspte = 2; 5431c50d8ae3SPaolo Bonzini } 5432c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5433c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5434c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5435c50d8ae3SPaolo Bonzini return NULL; 5436c50d8ae3SPaolo Bonzini } 5437c50d8ae3SPaolo Bonzini 5438c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5439c50d8ae3SPaolo Bonzini return spte; 5440c50d8ae3SPaolo Bonzini } 5441c50d8ae3SPaolo Bonzini 5442c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5443c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5444c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5445c50d8ae3SPaolo Bonzini { 5446c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5447c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5448c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5449c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5450c50d8ae3SPaolo Bonzini int npte; 545106152b2dSLai Jiangshan bool flush = false; 5452c50d8ae3SPaolo Bonzini 5453c50d8ae3SPaolo Bonzini /* 5454c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5455c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5456c50d8ae3SPaolo Bonzini */ 5457c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5458c50d8ae3SPaolo Bonzini return; 5459c50d8ae3SPaolo Bonzini 5460c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5461c50d8ae3SPaolo Bonzini 5462531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5463c50d8ae3SPaolo Bonzini 5464c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5465c50d8ae3SPaolo Bonzini 5466c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5467c50d8ae3SPaolo Bonzini 5468767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5469c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5470c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5471c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5472c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5473c50d8ae3SPaolo Bonzini continue; 5474c50d8ae3SPaolo Bonzini } 5475c50d8ae3SPaolo Bonzini 5476c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5477c50d8ae3SPaolo Bonzini if (!spte) 5478c50d8ae3SPaolo Bonzini continue; 5479c50d8ae3SPaolo Bonzini 5480c50d8ae3SPaolo Bonzini while (npte--) { 5481c50d8ae3SPaolo Bonzini entry = *spte; 54822de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5483c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5484c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 5485c50d8ae3SPaolo Bonzini if (need_remote_flush(entry, *spte)) 548606152b2dSLai Jiangshan flush = true; 5487c50d8ae3SPaolo Bonzini ++spte; 5488c50d8ae3SPaolo Bonzini } 5489c50d8ae3SPaolo Bonzini } 549006152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5491531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5492c50d8ae3SPaolo Bonzini } 5493c50d8ae3SPaolo Bonzini 54941075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5495c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5496c50d8ae3SPaolo Bonzini { 549792daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5498347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5499c50d8ae3SPaolo Bonzini 5500b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5501ddce6208SSean Christopherson return RET_PF_RETRY; 5502ddce6208SSean Christopherson 5503c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5504c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5505736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5506c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5507c50d8ae3SPaolo Bonzini goto emulate; 5508c50d8ae3SPaolo Bonzini } 5509c50d8ae3SPaolo Bonzini 5510c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 55117a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 55127a02674dSSean Christopherson lower_32_bits(error_code), false); 551319025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 55147b367bc9SSean Christopherson return -EIO; 5515c50d8ae3SPaolo Bonzini } 5516c50d8ae3SPaolo Bonzini 5517c50d8ae3SPaolo Bonzini if (r < 0) 5518c50d8ae3SPaolo Bonzini return r; 551983a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 552083a2ba4cSSean Christopherson return 1; 5521c50d8ae3SPaolo Bonzini 5522c50d8ae3SPaolo Bonzini /* 5523c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5524c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5525c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5526c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5527c50d8ae3SPaolo Bonzini * and resume the guest. 5528c50d8ae3SPaolo Bonzini */ 5529347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5530c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5531736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5532c50d8ae3SPaolo Bonzini return 1; 5533c50d8ae3SPaolo Bonzini } 5534c50d8ae3SPaolo Bonzini 5535c50d8ae3SPaolo Bonzini /* 5536c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5537c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5538c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5539c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5540c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5541c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5542c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5543c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5544c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5545c50d8ae3SPaolo Bonzini */ 5546736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 554792daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5548c50d8ae3SPaolo Bonzini emulate: 5549736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5550c50d8ae3SPaolo Bonzini insn_len); 5551c50d8ae3SPaolo Bonzini } 5552c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5553c50d8ae3SPaolo Bonzini 55545efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 55555efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5556c50d8ae3SPaolo Bonzini { 5557c50d8ae3SPaolo Bonzini int i; 5558c50d8ae3SPaolo Bonzini 55595efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 55605efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 55615efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5562c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5563c50d8ae3SPaolo Bonzini return; 5564c50d8ae3SPaolo Bonzini 5565e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 55665efac074SPaolo Bonzini } 55675efac074SPaolo Bonzini 55685efac074SPaolo Bonzini if (!mmu->invlpg) 55695efac074SPaolo Bonzini return; 55705efac074SPaolo Bonzini 55715efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5572b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5573c50d8ae3SPaolo Bonzini 5574c50d8ae3SPaolo Bonzini /* 5575c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5576c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5577c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5578c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5579c50d8ae3SPaolo Bonzini * just always sync it. 5580c50d8ae3SPaolo Bonzini * 5581c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5582c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5583c50d8ae3SPaolo Bonzini * for them. 5584c50d8ae3SPaolo Bonzini */ 5585c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5586c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5587c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 55885efac074SPaolo Bonzini } else { 55895efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 55905efac074SPaolo Bonzini } 55915efac074SPaolo Bonzini } 5592c50d8ae3SPaolo Bonzini 55935efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 55945efac074SPaolo Bonzini { 559505b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5596c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5597c50d8ae3SPaolo Bonzini } 5598c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5599c50d8ae3SPaolo Bonzini 56005efac074SPaolo Bonzini 5601c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5602c50d8ae3SPaolo Bonzini { 5603c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5604c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5605c50d8ae3SPaolo Bonzini uint i; 5606c50d8ae3SPaolo Bonzini 5607c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 56089f46c187SPaolo Bonzini if (mmu->invlpg) 5609b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5610c50d8ae3SPaolo Bonzini tlb_flush = true; 5611c50d8ae3SPaolo Bonzini } 5612c50d8ae3SPaolo Bonzini 5613c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5614c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5615be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 56169f46c187SPaolo Bonzini if (mmu->invlpg) 5617c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5618c50d8ae3SPaolo Bonzini tlb_flush = true; 5619c50d8ae3SPaolo Bonzini } 5620c50d8ae3SPaolo Bonzini } 5621c50d8ae3SPaolo Bonzini 5622c50d8ae3SPaolo Bonzini if (tlb_flush) 5623e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5624c50d8ae3SPaolo Bonzini 5625c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5626c50d8ae3SPaolo Bonzini 5627c50d8ae3SPaolo Bonzini /* 5628c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5629c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5630c50d8ae3SPaolo Bonzini * for them. 5631c50d8ae3SPaolo Bonzini */ 5632c50d8ae3SPaolo Bonzini } 5633c50d8ae3SPaolo Bonzini 5634746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5635746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5636c50d8ae3SPaolo Bonzini { 5637bde77235SSean Christopherson tdp_enabled = enable_tdp; 5638746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 563983013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5640703c335dSSean Christopherson 5641703c335dSSean Christopherson /* 56421d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5643703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5644703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5645703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5646703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5647703c335dSSean Christopherson */ 5648703c335dSSean Christopherson if (tdp_enabled) 56491d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5650703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 56511d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5652703c335dSSean Christopherson else 56531d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5654c50d8ae3SPaolo Bonzini } 5655bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5656c50d8ae3SPaolo Bonzini 5657c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5658269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5659269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5660269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5661c50d8ae3SPaolo Bonzini 5662c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5663c50d8ae3SPaolo Bonzini static __always_inline bool 5664269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5665c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 56661a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 56671a61b7dbSSean Christopherson bool flush) 5668c50d8ae3SPaolo Bonzini { 5669c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5670c50d8ae3SPaolo Bonzini 5671c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5672c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5673c50d8ae3SPaolo Bonzini if (iterator.rmap) 56740a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5675c50d8ae3SPaolo Bonzini 5676531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5677302695a5SSean Christopherson if (flush && flush_on_yield) { 5678c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5679c50d8ae3SPaolo Bonzini start_gfn, 5680c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5681c50d8ae3SPaolo Bonzini flush = false; 5682c50d8ae3SPaolo Bonzini } 5683531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5684c50d8ae3SPaolo Bonzini } 5685c50d8ae3SPaolo Bonzini } 5686c50d8ae3SPaolo Bonzini 5687c50d8ae3SPaolo Bonzini return flush; 5688c50d8ae3SPaolo Bonzini } 5689c50d8ae3SPaolo Bonzini 5690c50d8ae3SPaolo Bonzini static __always_inline bool 5691269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5692c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5693302695a5SSean Christopherson bool flush_on_yield) 5694c50d8ae3SPaolo Bonzini { 5695c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5696c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5697c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 56981a61b7dbSSean Christopherson flush_on_yield, false); 5699c50d8ae3SPaolo Bonzini } 5700c50d8ae3SPaolo Bonzini 5701c50d8ae3SPaolo Bonzini static __always_inline bool 5702610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5703302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5704c50d8ae3SPaolo Bonzini { 57053bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5706302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5707c50d8ae3SPaolo Bonzini } 5708c50d8ae3SPaolo Bonzini 5709c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5710c50d8ae3SPaolo Bonzini { 57114a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 57124a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5713c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 571403ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5715cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5716c50d8ae3SPaolo Bonzini } 5717c50d8ae3SPaolo Bonzini 571804d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5719c50d8ae3SPaolo Bonzini { 5720c50d8ae3SPaolo Bonzini struct page *page; 5721c50d8ae3SPaolo Bonzini int i; 5722c50d8ae3SPaolo Bonzini 5723b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5724b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 572504d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 572604d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 572704d28e37SSean Christopherson 572827f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 572927f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 573027f4fca2SLai Jiangshan return 0; 573127f4fca2SLai Jiangshan 5732c50d8ae3SPaolo Bonzini /* 5733c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5734c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5735c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5736c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 573704d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 573804d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 573904d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 574004d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 574184432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5742c50d8ae3SPaolo Bonzini */ 5743d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5744c50d8ae3SPaolo Bonzini return 0; 5745c50d8ae3SPaolo Bonzini 5746c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5747c50d8ae3SPaolo Bonzini if (!page) 5748c50d8ae3SPaolo Bonzini return -ENOMEM; 5749c50d8ae3SPaolo Bonzini 5750c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 57514a98623dSSean Christopherson 57524a98623dSSean Christopherson /* 57534a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 57544a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 57554a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 57564a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 57574a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 57584a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 57594a98623dSSean Christopherson */ 57604a98623dSSean Christopherson if (!tdp_enabled) 57614a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 57624a98623dSSean Christopherson else 5763e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 57644a98623dSSean Christopherson 5765c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5766c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5767c50d8ae3SPaolo Bonzini 5768c50d8ae3SPaolo Bonzini return 0; 5769c50d8ae3SPaolo Bonzini } 5770c50d8ae3SPaolo Bonzini 5771c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5772c50d8ae3SPaolo Bonzini { 5773c50d8ae3SPaolo Bonzini int ret; 5774c50d8ae3SPaolo Bonzini 57755962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 57765f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 57775f6078f9SSean Christopherson 57785962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 57795f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 57805962bfb7SSean Christopherson 578196880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 578296880883SSean Christopherson 5783c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5784c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5785c50d8ae3SPaolo Bonzini 578604d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5787c50d8ae3SPaolo Bonzini if (ret) 5788c50d8ae3SPaolo Bonzini return ret; 5789c50d8ae3SPaolo Bonzini 579004d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5791c50d8ae3SPaolo Bonzini if (ret) 5792c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5793c50d8ae3SPaolo Bonzini 5794c50d8ae3SPaolo Bonzini return ret; 5795c50d8ae3SPaolo Bonzini fail_allocate_root: 5796c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5797c50d8ae3SPaolo Bonzini return ret; 5798c50d8ae3SPaolo Bonzini } 5799c50d8ae3SPaolo Bonzini 5800c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5801c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5802c50d8ae3SPaolo Bonzini { 5803c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5804c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5805b28cb0cdSSean Christopherson bool unstable; 5806c50d8ae3SPaolo Bonzini 5807c50d8ae3SPaolo Bonzini restart: 5808c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5809c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5810c50d8ae3SPaolo Bonzini /* 5811c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5812c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5813c50d8ae3SPaolo Bonzini */ 5814c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5815c50d8ae3SPaolo Bonzini break; 5816c50d8ae3SPaolo Bonzini 5817c50d8ae3SPaolo Bonzini /* 5818f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5819f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5820f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5821c50d8ae3SPaolo Bonzini */ 5822f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5823c50d8ae3SPaolo Bonzini continue; 5824c50d8ae3SPaolo Bonzini 5825c50d8ae3SPaolo Bonzini /* 5826c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5827c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5828c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5829c50d8ae3SPaolo Bonzini * be in active use by the guest. 5830c50d8ae3SPaolo Bonzini */ 5831c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5832531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5833c50d8ae3SPaolo Bonzini batch = 0; 5834c50d8ae3SPaolo Bonzini goto restart; 5835c50d8ae3SPaolo Bonzini } 5836c50d8ae3SPaolo Bonzini 5837b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 5838b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 5839c50d8ae3SPaolo Bonzini batch += nr_zapped; 5840b28cb0cdSSean Christopherson 5841b28cb0cdSSean Christopherson if (unstable) 5842c50d8ae3SPaolo Bonzini goto restart; 5843c50d8ae3SPaolo Bonzini } 5844c50d8ae3SPaolo Bonzini 5845c50d8ae3SPaolo Bonzini /* 58467ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 58477ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 58487ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 58497ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 58507ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 58517ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 58527ae5840eSSean Christopherson * running with an obsolete MMU. 5853c50d8ae3SPaolo Bonzini */ 5854c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5855c50d8ae3SPaolo Bonzini } 5856c50d8ae3SPaolo Bonzini 5857c50d8ae3SPaolo Bonzini /* 5858c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5859c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5860c50d8ae3SPaolo Bonzini * 5861c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5862c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5863c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5864c50d8ae3SPaolo Bonzini * after calling the function. 5865c50d8ae3SPaolo Bonzini */ 5866c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5867c50d8ae3SPaolo Bonzini { 5868c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5869c50d8ae3SPaolo Bonzini 5870531810caSBen Gardon write_lock(&kvm->mmu_lock); 5871c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5872c50d8ae3SPaolo Bonzini 5873c50d8ae3SPaolo Bonzini /* 5874c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5875c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5876c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5877c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5878c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5879c50d8ae3SPaolo Bonzini */ 5880c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5881c50d8ae3SPaolo Bonzini 58822f6f66ccSSean Christopherson /* 58832f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 58842f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 58852f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 58862f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5887b7cccd39SBen Gardon */ 5888b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5889b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5890b7cccd39SBen Gardon 5891c50d8ae3SPaolo Bonzini /* 5892c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5893c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5894c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5895c50d8ae3SPaolo Bonzini * 5896c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5897c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5898c50d8ae3SPaolo Bonzini */ 5899527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5900c50d8ae3SPaolo Bonzini 5901c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5902faaf05b0SBen Gardon 5903531810caSBen Gardon write_unlock(&kvm->mmu_lock); 59044c6654bdSBen Gardon 5905f28e9c7fSSean Christopherson /* 5906f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5907f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5908f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5909f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5910f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5911f28e9c7fSSean Christopherson * lead to use-after-free. 5912f28e9c7fSSean Christopherson */ 591322b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 59144c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5915c50d8ae3SPaolo Bonzini } 5916c50d8ae3SPaolo Bonzini 5917c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5918c50d8ae3SPaolo Bonzini { 5919c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5920c50d8ae3SPaolo Bonzini } 5921c50d8ae3SPaolo Bonzini 5922c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5923c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5924c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5925c50d8ae3SPaolo Bonzini { 5926c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5927c50d8ae3SPaolo Bonzini } 5928c50d8ae3SPaolo Bonzini 5929a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5930c50d8ae3SPaolo Bonzini { 5931c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5932a1a39128SPaolo Bonzini int r; 5933c50d8ae3SPaolo Bonzini 5934a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5935a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5936a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5937ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5938ce25681dSSean Christopherson 5939a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5940a1a39128SPaolo Bonzini if (r < 0) 5941a1a39128SPaolo Bonzini return r; 5942fe5db27dSBen Gardon 5943c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5944c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5945c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5946a1a39128SPaolo Bonzini return 0; 5947c50d8ae3SPaolo Bonzini } 5948c50d8ae3SPaolo Bonzini 5949c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 5950c50d8ae3SPaolo Bonzini { 5951c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5952c50d8ae3SPaolo Bonzini 5953c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 5954fe5db27dSBen Gardon 5955fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 5956c50d8ae3SPaolo Bonzini } 5957c50d8ae3SPaolo Bonzini 595821fa3246SSean Christopherson static bool __kvm_zap_rmaps(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 595921fa3246SSean Christopherson { 596021fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 596121fa3246SSean Christopherson struct kvm_memslots *slots; 5962f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 596321fa3246SSean Christopherson bool flush = false; 596421fa3246SSean Christopherson gfn_t start, end; 5965f4209439SMaciej S. Szmigiero int i; 596621fa3246SSean Christopherson 596721fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 596821fa3246SSean Christopherson return flush; 596921fa3246SSean Christopherson 597021fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 597121fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 5972f4209439SMaciej S. Szmigiero 5973f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 5974f4209439SMaciej S. Szmigiero memslot = iter.slot; 597521fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 597621fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 5977f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 597821fa3246SSean Christopherson continue; 597921fa3246SSean Christopherson 598021fa3246SSean Christopherson flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, 59816ff94f27SDavid Matlack 598221fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 598321fa3246SSean Christopherson start, end - 1, true, flush); 598421fa3246SSean Christopherson } 598521fa3246SSean Christopherson } 598621fa3246SSean Christopherson 598721fa3246SSean Christopherson return flush; 598821fa3246SSean Christopherson } 598921fa3246SSean Christopherson 599088f58535SMaxim Levitsky /* 599188f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 599288f58535SMaxim Levitsky * (not including it) 599388f58535SMaxim Levitsky */ 5994c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 5995c50d8ae3SPaolo Bonzini { 599621fa3246SSean Christopherson bool flush; 5997c50d8ae3SPaolo Bonzini int i; 5998c50d8ae3SPaolo Bonzini 5999f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6000f4209439SMaciej S. Szmigiero return; 6001f4209439SMaciej S. Szmigiero 6002531810caSBen Gardon write_lock(&kvm->mmu_lock); 60035a324c24SSean Christopherson 6004edb298c6SMaxim Levitsky kvm_inc_notifier_count(kvm, gfn_start, gfn_end); 6005edb298c6SMaxim Levitsky 600621fa3246SSean Christopherson flush = __kvm_zap_rmaps(kvm, gfn_start, gfn_end); 60076103bc07SBen Gardon 60086103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60096103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 6010f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 6011f47e5bbbSSean Christopherson gfn_end, true, flush); 60126103bc07SBen Gardon } 60135a324c24SSean Christopherson 60145a324c24SSean Christopherson if (flush) 6015bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 6016bc3b3c10SSean Christopherson gfn_end - gfn_start); 60175a324c24SSean Christopherson 6018edb298c6SMaxim Levitsky kvm_dec_notifier_count(kvm, gfn_start, gfn_end); 6019edb298c6SMaxim Levitsky 60205a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6021c50d8ae3SPaolo Bonzini } 6022c50d8ae3SPaolo Bonzini 6023c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 60240a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6025269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6026c50d8ae3SPaolo Bonzini { 60271346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6028c50d8ae3SPaolo Bonzini } 6029c50d8ae3SPaolo Bonzini 6030c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6031269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 60323c9bd400SJay Zhou int start_level) 6033c50d8ae3SPaolo Bonzini { 6034e2209710SBen Gardon bool flush = false; 6035c50d8ae3SPaolo Bonzini 6036e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6037531810caSBen Gardon write_lock(&kvm->mmu_lock); 60383c9bd400SJay Zhou flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, 6039e2209710SBen Gardon start_level, KVM_MAX_HUGEPAGE_LEVEL, 6040e2209710SBen Gardon false); 6041531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6042e2209710SBen Gardon } 6043c50d8ae3SPaolo Bonzini 604424ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 604524ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 604624ae4cfaSBen Gardon flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 604724ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 604824ae4cfaSBen Gardon } 604924ae4cfaSBen Gardon 6050c50d8ae3SPaolo Bonzini /* 60516ff94f27SDavid Matlack * Flush TLBs if any SPTEs had to be write-protected to ensure that 60526ff94f27SDavid Matlack * guest writes are reflected in the dirty bitmap before the memslot 60536ff94f27SDavid Matlack * update completes, i.e. before enabling dirty logging is visible to 60546ff94f27SDavid Matlack * userspace. 60556ff94f27SDavid Matlack * 60566ff94f27SDavid Matlack * Perform the TLB flush outside the mmu_lock to reduce the amount of 60576ff94f27SDavid Matlack * time the lock is held. However, this does mean that another CPU can 60586ff94f27SDavid Matlack * now grab mmu_lock and encounter a write-protected SPTE while CPUs 60596ff94f27SDavid Matlack * still have a writable mapping for the associated GFN in their TLB. 60606ff94f27SDavid Matlack * 60616ff94f27SDavid Matlack * This is safe but requires KVM to be careful when making decisions 60626ff94f27SDavid Matlack * based on the write-protection status of an SPTE. Specifically, KVM 60636ff94f27SDavid Matlack * also write-protects SPTEs to monitor changes to guest page tables 60646ff94f27SDavid Matlack * during shadow paging, and must guarantee no CPUs can write to those 60656ff94f27SDavid Matlack * page before the lock is dropped. As mentioned in the previous 60666ff94f27SDavid Matlack * paragraph, a write-protected SPTE is no guarantee that CPU cannot 60676ff94f27SDavid Matlack * perform writes. So to determine if a TLB flush is truly required, KVM 60686ff94f27SDavid Matlack * will clear a separate software-only bit (MMU-writable) and skip the 60696ff94f27SDavid Matlack * flush if-and-only-if this bit was already clear. 60706ff94f27SDavid Matlack * 607102844ac1SDavid Matlack * See is_writable_pte() for more details. 6072c50d8ae3SPaolo Bonzini */ 6073c50d8ae3SPaolo Bonzini if (flush) 60747f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6075c50d8ae3SPaolo Bonzini } 6076c50d8ae3SPaolo Bonzini 6077cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6078cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6079cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6080cb00a70bSDavid Matlack u64 start, u64 end, 6081cb00a70bSDavid Matlack int target_level) 6082cb00a70bSDavid Matlack { 6083cb00a70bSDavid Matlack if (is_tdp_mmu_enabled(kvm)) 6084cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, 6085cb00a70bSDavid Matlack target_level, false); 6086cb00a70bSDavid Matlack 6087cb00a70bSDavid Matlack /* 6088cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6089cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6090cb00a70bSDavid Matlack */ 6091cb00a70bSDavid Matlack } 6092cb00a70bSDavid Matlack 6093a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6094a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6095a3fe5dbdSDavid Matlack int target_level) 6096a3fe5dbdSDavid Matlack { 6097a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6098a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6099a3fe5dbdSDavid Matlack 6100a3fe5dbdSDavid Matlack if (is_tdp_mmu_enabled(kvm)) { 6101a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6102cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6103a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6104a3fe5dbdSDavid Matlack } 6105a3fe5dbdSDavid Matlack 6106a3fe5dbdSDavid Matlack /* 6107a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6108a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6109a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6110a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6111a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6112a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6113a3fe5dbdSDavid Matlack * SPTEs. 6114a3fe5dbdSDavid Matlack */ 6115a3fe5dbdSDavid Matlack } 6116a3fe5dbdSDavid Matlack 6117c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 61180a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6119269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6120c50d8ae3SPaolo Bonzini { 6121c50d8ae3SPaolo Bonzini u64 *sptep; 6122c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6123c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6124c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 6125c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6126c50d8ae3SPaolo Bonzini 6127c50d8ae3SPaolo Bonzini restart: 6128c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 612957354682SSean Christopherson sp = sptep_to_sp(sptep); 6130c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(*sptep); 6131c50d8ae3SPaolo Bonzini 6132c50d8ae3SPaolo Bonzini /* 6133c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6134c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6135c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6136c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6137c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6138c50d8ae3SPaolo Bonzini */ 61395d49f08cSSean Christopherson if (sp->role.direct && 61409eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 61419eba50f8SSean Christopherson pfn, PG_LEVEL_NUM)) { 614271f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 6143c50d8ae3SPaolo Bonzini 6144c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6145c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6146c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6147c50d8ae3SPaolo Bonzini else 6148c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6149c50d8ae3SPaolo Bonzini 6150c50d8ae3SPaolo Bonzini goto restart; 6151c50d8ae3SPaolo Bonzini } 6152c50d8ae3SPaolo Bonzini } 6153c50d8ae3SPaolo Bonzini 6154c50d8ae3SPaolo Bonzini return need_tlb_flush; 6155c50d8ae3SPaolo Bonzini } 6156c50d8ae3SPaolo Bonzini 6157c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6158269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6159c50d8ae3SPaolo Bonzini { 6160e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6161531810caSBen Gardon write_lock(&kvm->mmu_lock); 6162610265eaSDavid Matlack /* 6163610265eaSDavid Matlack * Zap only 4k SPTEs since the legacy MMU only supports dirty 6164610265eaSDavid Matlack * logging at a 4k granularity and never creates collapsible 6165610265eaSDavid Matlack * 2m SPTEs during dirty logging. 6166610265eaSDavid Matlack */ 61674b85c921SSean Christopherson if (slot_handle_level_4k(kvm, slot, kvm_mmu_zap_collapsible_spte, true)) 6168302695a5SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 6169531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6170e2209710SBen Gardon } 61712db6f772SBen Gardon 61722db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 61732db6f772SBen Gardon read_lock(&kvm->mmu_lock); 61744b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 61752db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 61762db6f772SBen Gardon } 6177c50d8ae3SPaolo Bonzini } 6178c50d8ae3SPaolo Bonzini 6179b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 61806c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6181b3594ffbSSean Christopherson { 6182b3594ffbSSean Christopherson /* 61837f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6184302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 61857f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 61867f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 61877f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6188b3594ffbSSean Christopherson */ 6189b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6190cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6191cec37648SSean Christopherson memslot->npages); 6192b3594ffbSSean Christopherson } 6193b3594ffbSSean Christopherson 6194c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6195269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6196c50d8ae3SPaolo Bonzini { 6197e2209710SBen Gardon bool flush = false; 6198c50d8ae3SPaolo Bonzini 6199e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6200531810caSBen Gardon write_lock(&kvm->mmu_lock); 6201610265eaSDavid Matlack /* 6202610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6203610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6204610265eaSDavid Matlack */ 6205610265eaSDavid Matlack flush = slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6206531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6207e2209710SBen Gardon } 6208c50d8ae3SPaolo Bonzini 620924ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 621024ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 621124ae4cfaSBen Gardon flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 621224ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 621324ae4cfaSBen Gardon } 621424ae4cfaSBen Gardon 6215c50d8ae3SPaolo Bonzini /* 6216c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6217c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6218c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6219c50d8ae3SPaolo Bonzini * dirty_bitmap. 6220c50d8ae3SPaolo Bonzini */ 6221c50d8ae3SPaolo Bonzini if (flush) 62227f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6223c50d8ae3SPaolo Bonzini } 6224c50d8ae3SPaolo Bonzini 6225c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6226c50d8ae3SPaolo Bonzini { 6227c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6228c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6229c50d8ae3SPaolo Bonzini int ign; 6230c50d8ae3SPaolo Bonzini 6231531810caSBen Gardon write_lock(&kvm->mmu_lock); 6232c50d8ae3SPaolo Bonzini restart: 6233c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6234f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6235c50d8ae3SPaolo Bonzini continue; 6236c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6237c50d8ae3SPaolo Bonzini goto restart; 6238531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6239c50d8ae3SPaolo Bonzini goto restart; 6240c50d8ae3SPaolo Bonzini } 6241c50d8ae3SPaolo Bonzini 6242c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6243faaf05b0SBen Gardon 6244897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6245faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6246faaf05b0SBen Gardon 6247531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6248c50d8ae3SPaolo Bonzini } 6249c50d8ae3SPaolo Bonzini 6250c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6251c50d8ae3SPaolo Bonzini { 6252c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6253c50d8ae3SPaolo Bonzini 6254c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6255c50d8ae3SPaolo Bonzini 6256c50d8ae3SPaolo Bonzini /* 6257c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6258c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6259c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6260c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6261c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6262c50d8ae3SPaolo Bonzini */ 6263c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6264c50d8ae3SPaolo Bonzini 6265c50d8ae3SPaolo Bonzini /* 6266c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6267c50d8ae3SPaolo Bonzini * zap all shadow pages. 6268c50d8ae3SPaolo Bonzini */ 6269c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6270c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6271c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6272c50d8ae3SPaolo Bonzini } 6273c50d8ae3SPaolo Bonzini } 6274c50d8ae3SPaolo Bonzini 6275c50d8ae3SPaolo Bonzini static unsigned long 6276c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6277c50d8ae3SPaolo Bonzini { 6278c50d8ae3SPaolo Bonzini struct kvm *kvm; 6279c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6280c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6281c50d8ae3SPaolo Bonzini 6282c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6283c50d8ae3SPaolo Bonzini 6284c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6285c50d8ae3SPaolo Bonzini int idx; 6286c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6287c50d8ae3SPaolo Bonzini 6288c50d8ae3SPaolo Bonzini /* 6289c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6290c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6291c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6292c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6293c50d8ae3SPaolo Bonzini */ 6294c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6295c50d8ae3SPaolo Bonzini break; 6296c50d8ae3SPaolo Bonzini /* 6297c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6298c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6299c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6300c50d8ae3SPaolo Bonzini * anyway. 6301c50d8ae3SPaolo Bonzini */ 6302c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6303c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6304c50d8ae3SPaolo Bonzini continue; 6305c50d8ae3SPaolo Bonzini 6306c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6307531810caSBen Gardon write_lock(&kvm->mmu_lock); 6308c50d8ae3SPaolo Bonzini 6309c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6310c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6311c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6312c50d8ae3SPaolo Bonzini goto unlock; 6313c50d8ae3SPaolo Bonzini } 6314c50d8ae3SPaolo Bonzini 6315ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6316c50d8ae3SPaolo Bonzini 6317c50d8ae3SPaolo Bonzini unlock: 6318531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6319c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6320c50d8ae3SPaolo Bonzini 6321c50d8ae3SPaolo Bonzini /* 6322c50d8ae3SPaolo Bonzini * unfair on small ones 6323c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6324c50d8ae3SPaolo Bonzini * sadness comes quickly 6325c50d8ae3SPaolo Bonzini */ 6326c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6327c50d8ae3SPaolo Bonzini break; 6328c50d8ae3SPaolo Bonzini } 6329c50d8ae3SPaolo Bonzini 6330c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6331c50d8ae3SPaolo Bonzini return freed; 6332c50d8ae3SPaolo Bonzini } 6333c50d8ae3SPaolo Bonzini 6334c50d8ae3SPaolo Bonzini static unsigned long 6335c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6336c50d8ae3SPaolo Bonzini { 6337c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6338c50d8ae3SPaolo Bonzini } 6339c50d8ae3SPaolo Bonzini 6340c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6341c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6342c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6343c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6344c50d8ae3SPaolo Bonzini }; 6345c50d8ae3SPaolo Bonzini 6346c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6347c50d8ae3SPaolo Bonzini { 6348c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6349c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6350c50d8ae3SPaolo Bonzini } 6351c50d8ae3SPaolo Bonzini 6352c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6353c50d8ae3SPaolo Bonzini { 6354c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6355c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6356c50d8ae3SPaolo Bonzini } 6357c50d8ae3SPaolo Bonzini 6358c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6359c50d8ae3SPaolo Bonzini { 6360c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6361c50d8ae3SPaolo Bonzini } 6362c50d8ae3SPaolo Bonzini 6363c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6364c50d8ae3SPaolo Bonzini { 6365c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6366c50d8ae3SPaolo Bonzini bool new_val; 6367c50d8ae3SPaolo Bonzini 6368c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6369c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6370c50d8ae3SPaolo Bonzini new_val = 0; 6371c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6372c50d8ae3SPaolo Bonzini new_val = 1; 6373c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6374c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6375c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6376c50d8ae3SPaolo Bonzini return -EINVAL; 6377c50d8ae3SPaolo Bonzini 6378c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6379c50d8ae3SPaolo Bonzini 6380c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6381c50d8ae3SPaolo Bonzini struct kvm *kvm; 6382c50d8ae3SPaolo Bonzini 6383c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6384c50d8ae3SPaolo Bonzini 6385c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6386c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6387c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6388c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6389c50d8ae3SPaolo Bonzini 6390c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6391c50d8ae3SPaolo Bonzini } 6392c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6393c50d8ae3SPaolo Bonzini } 6394c50d8ae3SPaolo Bonzini 6395c50d8ae3SPaolo Bonzini return 0; 6396c50d8ae3SPaolo Bonzini } 6397c50d8ae3SPaolo Bonzini 63981d0e8480SSean Christopherson /* 63991d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 64001d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 64011d0e8480SSean Christopherson */ 64021d0e8480SSean Christopherson void kvm_mmu_x86_module_init(void) 6403c50d8ae3SPaolo Bonzini { 6404c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6405c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 64061d0e8480SSean Christopherson } 64071d0e8480SSean Christopherson 64081d0e8480SSean Christopherson /* 64091d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 64101d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 64111d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 64121d0e8480SSean Christopherson */ 64131d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 64141d0e8480SSean Christopherson { 64151d0e8480SSean Christopherson int ret = -ENOMEM; 6416c50d8ae3SPaolo Bonzini 6417c50d8ae3SPaolo Bonzini /* 6418c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6419c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6420c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6421c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6422c50d8ae3SPaolo Bonzini */ 6423c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6424c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 64257a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6426c50d8ae3SPaolo Bonzini 6427c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6428c50d8ae3SPaolo Bonzini 6429c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6430c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6431c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6432c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6433c50d8ae3SPaolo Bonzini goto out; 6434c50d8ae3SPaolo Bonzini 6435c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6436c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6437c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6438c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6439c50d8ae3SPaolo Bonzini goto out; 6440c50d8ae3SPaolo Bonzini 6441c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6442c50d8ae3SPaolo Bonzini goto out; 6443c50d8ae3SPaolo Bonzini 6444c50d8ae3SPaolo Bonzini ret = register_shrinker(&mmu_shrinker); 6445c50d8ae3SPaolo Bonzini if (ret) 6446c50d8ae3SPaolo Bonzini goto out; 6447c50d8ae3SPaolo Bonzini 6448c50d8ae3SPaolo Bonzini return 0; 6449c50d8ae3SPaolo Bonzini 6450c50d8ae3SPaolo Bonzini out: 6451c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6452c50d8ae3SPaolo Bonzini return ret; 6453c50d8ae3SPaolo Bonzini } 6454c50d8ae3SPaolo Bonzini 6455c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6456c50d8ae3SPaolo Bonzini { 6457c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6458c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6459c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6460c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6461c50d8ae3SPaolo Bonzini } 6462c50d8ae3SPaolo Bonzini 64631d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6464c50d8ae3SPaolo Bonzini { 6465c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6466c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6467c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6468c50d8ae3SPaolo Bonzini } 6469c50d8ae3SPaolo Bonzini 6470f47491d7SSean Christopherson /* 6471f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6472f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6473f47491d7SSean Christopherson */ 6474f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6475f47491d7SSean Christopherson { 6476f47491d7SSean Christopherson /* 6477f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6478f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6479f47491d7SSean Christopherson */ 6480f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6481f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6482f47491d7SSean Christopherson 6483f47491d7SSean Christopherson if (!enabled || !ratio) 6484f47491d7SSean Christopherson return false; 6485f47491d7SSean Christopherson 6486f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6487f47491d7SSean Christopherson if (!*period) { 6488f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6489f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6490f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6491f47491d7SSean Christopherson } 6492f47491d7SSean Christopherson return true; 6493f47491d7SSean Christopherson } 6494f47491d7SSean Christopherson 64954dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6496c50d8ae3SPaolo Bonzini { 64974dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 64984dfe4f40SJunaid Shahid uint old_period, new_period; 6499c50d8ae3SPaolo Bonzini int err; 6500c50d8ae3SPaolo Bonzini 6501f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 65024dfe4f40SJunaid Shahid 6503c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6504c50d8ae3SPaolo Bonzini if (err) 6505c50d8ae3SPaolo Bonzini return err; 6506c50d8ae3SPaolo Bonzini 6507f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 65084dfe4f40SJunaid Shahid 6509f47491d7SSean Christopherson if (is_recovery_enabled && 65104dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6511c50d8ae3SPaolo Bonzini struct kvm *kvm; 6512c50d8ae3SPaolo Bonzini 6513c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6514c50d8ae3SPaolo Bonzini 6515c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6516c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6517c50d8ae3SPaolo Bonzini 6518c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6519c50d8ae3SPaolo Bonzini } 6520c50d8ae3SPaolo Bonzini 6521c50d8ae3SPaolo Bonzini return err; 6522c50d8ae3SPaolo Bonzini } 6523c50d8ae3SPaolo Bonzini 6524c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6525c50d8ae3SPaolo Bonzini { 6526ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6527c50d8ae3SPaolo Bonzini int rcu_idx; 6528c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6529c50d8ae3SPaolo Bonzini unsigned int ratio; 6530c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6531048f4980SSean Christopherson bool flush = false; 6532c50d8ae3SPaolo Bonzini ulong to_zap; 6533c50d8ae3SPaolo Bonzini 6534c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6535531810caSBen Gardon write_lock(&kvm->mmu_lock); 6536c50d8ae3SPaolo Bonzini 6537bb95dfb9SSean Christopherson /* 6538bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6539bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6540bb95dfb9SSean Christopherson * callback. 6541bb95dfb9SSean Christopherson */ 6542bb95dfb9SSean Christopherson rcu_read_lock(); 6543bb95dfb9SSean Christopherson 6544c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6545ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 65467d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 65477d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 65487d919c7aSSean Christopherson break; 65497d919c7aSSean Christopherson 6550c50d8ae3SPaolo Bonzini /* 6551c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6552c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6553c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6554c50d8ae3SPaolo Bonzini */ 6555c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6556c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6557c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6558c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6559897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6560315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 65618d1a182eSBen Gardon } else { 6562c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6563c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 656429cf0f50SBen Gardon } 6565c50d8ae3SPaolo Bonzini 6566531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6567048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6568bb95dfb9SSean Christopherson rcu_read_unlock(); 6569bb95dfb9SSean Christopherson 6570531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6571048f4980SSean Christopherson flush = false; 6572bb95dfb9SSean Christopherson 6573bb95dfb9SSean Christopherson rcu_read_lock(); 6574c50d8ae3SPaolo Bonzini } 6575c50d8ae3SPaolo Bonzini } 6576048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6577c50d8ae3SPaolo Bonzini 6578bb95dfb9SSean Christopherson rcu_read_unlock(); 6579bb95dfb9SSean Christopherson 6580531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6581c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6582c50d8ae3SPaolo Bonzini } 6583c50d8ae3SPaolo Bonzini 6584c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6585c50d8ae3SPaolo Bonzini { 6586f47491d7SSean Christopherson bool enabled; 6587f47491d7SSean Christopherson uint period; 65884dfe4f40SJunaid Shahid 6589f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 65904dfe4f40SJunaid Shahid 6591f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6592c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6593c50d8ae3SPaolo Bonzini } 6594c50d8ae3SPaolo Bonzini 6595c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6596c50d8ae3SPaolo Bonzini { 6597c50d8ae3SPaolo Bonzini u64 start_time; 6598c50d8ae3SPaolo Bonzini long remaining_time; 6599c50d8ae3SPaolo Bonzini 6600c50d8ae3SPaolo Bonzini while (true) { 6601c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6602c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6603c50d8ae3SPaolo Bonzini 6604c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6605c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6606c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6607c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6608c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6609c50d8ae3SPaolo Bonzini } 6610c50d8ae3SPaolo Bonzini 6611c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6612c50d8ae3SPaolo Bonzini 6613c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6614c50d8ae3SPaolo Bonzini return 0; 6615c50d8ae3SPaolo Bonzini 6616c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6617c50d8ae3SPaolo Bonzini } 6618c50d8ae3SPaolo Bonzini } 6619c50d8ae3SPaolo Bonzini 6620c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6621c50d8ae3SPaolo Bonzini { 6622c50d8ae3SPaolo Bonzini int err; 6623c50d8ae3SPaolo Bonzini 6624c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6625c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6626c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6627c50d8ae3SPaolo Bonzini if (!err) 6628c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6629c50d8ae3SPaolo Bonzini 6630c50d8ae3SPaolo Bonzini return err; 6631c50d8ae3SPaolo Bonzini } 6632c50d8ae3SPaolo Bonzini 6633c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6634c50d8ae3SPaolo Bonzini { 6635c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6636c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6637c50d8ae3SPaolo Bonzini } 6638