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) { 65994ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_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); 67294ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_gfn_array_cache); 67394ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 674c50d8ae3SPaolo Bonzini } 675c50d8ae3SPaolo Bonzini 676c50d8ae3SPaolo Bonzini static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu) 677c50d8ae3SPaolo Bonzini { 67894ce87efSSean Christopherson return kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_list_desc_cache); 679c50d8ae3SPaolo Bonzini } 680c50d8ae3SPaolo Bonzini 681c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 682c50d8ae3SPaolo Bonzini { 683c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 684c50d8ae3SPaolo Bonzini } 685c50d8ae3SPaolo Bonzini 686c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 687c50d8ae3SPaolo Bonzini { 68884e5ffd0SLai Jiangshan if (sp->role.passthrough) 68984e5ffd0SLai Jiangshan return sp->gfn; 69084e5ffd0SLai Jiangshan 691c50d8ae3SPaolo Bonzini if (!sp->role.direct) 692c50d8ae3SPaolo Bonzini return sp->gfns[index]; 693c50d8ae3SPaolo Bonzini 6942ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 695c50d8ae3SPaolo Bonzini } 696c50d8ae3SPaolo Bonzini 697c50d8ae3SPaolo Bonzini static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn) 698c50d8ae3SPaolo Bonzini { 69984e5ffd0SLai Jiangshan if (sp->role.passthrough) { 70084e5ffd0SLai Jiangshan WARN_ON_ONCE(gfn != sp->gfn); 70184e5ffd0SLai Jiangshan return; 70284e5ffd0SLai Jiangshan } 70384e5ffd0SLai Jiangshan 704c50d8ae3SPaolo Bonzini if (!sp->role.direct) { 705c50d8ae3SPaolo Bonzini sp->gfns[index] = gfn; 706c50d8ae3SPaolo Bonzini return; 707c50d8ae3SPaolo Bonzini } 708c50d8ae3SPaolo Bonzini 709c50d8ae3SPaolo Bonzini if (WARN_ON(gfn != kvm_mmu_page_get_gfn(sp, index))) 710c50d8ae3SPaolo Bonzini pr_err_ratelimited("gfn mismatch under direct page %llx " 711c50d8ae3SPaolo Bonzini "(expected %llx, got %llx)\n", 712c50d8ae3SPaolo Bonzini sp->gfn, 713c50d8ae3SPaolo Bonzini kvm_mmu_page_get_gfn(sp, index), gfn); 714c50d8ae3SPaolo Bonzini } 715c50d8ae3SPaolo Bonzini 716c50d8ae3SPaolo Bonzini /* 717c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 718c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 719c50d8ae3SPaolo Bonzini */ 720c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7218ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 722c50d8ae3SPaolo Bonzini { 723c50d8ae3SPaolo Bonzini unsigned long idx; 724c50d8ae3SPaolo Bonzini 725c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 726c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 727c50d8ae3SPaolo Bonzini } 728c50d8ae3SPaolo Bonzini 729269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 730c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 731c50d8ae3SPaolo Bonzini { 732c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 733c50d8ae3SPaolo Bonzini int i; 734c50d8ae3SPaolo Bonzini 7353bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 736c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 737c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 738c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 739c50d8ae3SPaolo Bonzini } 740c50d8ae3SPaolo Bonzini } 741c50d8ae3SPaolo Bonzini 742269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 743c50d8ae3SPaolo Bonzini { 744c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 745c50d8ae3SPaolo Bonzini } 746c50d8ae3SPaolo Bonzini 747269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 748c50d8ae3SPaolo Bonzini { 749c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 750c50d8ae3SPaolo Bonzini } 751c50d8ae3SPaolo Bonzini 752c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 753c50d8ae3SPaolo Bonzini { 754c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 755c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 756c50d8ae3SPaolo Bonzini gfn_t gfn; 757c50d8ae3SPaolo Bonzini 758c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 759c50d8ae3SPaolo Bonzini gfn = sp->gfn; 760c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 761c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 762c50d8ae3SPaolo Bonzini 763c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 7643bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 765c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 766c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 767c50d8ae3SPaolo Bonzini 768c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 769*be911771SDavid Matlack 770*be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 771*be911771SDavid Matlack kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 772c50d8ae3SPaolo Bonzini } 773c50d8ae3SPaolo Bonzini 77429cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 775c50d8ae3SPaolo Bonzini { 776c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 777c50d8ae3SPaolo Bonzini return; 778c50d8ae3SPaolo Bonzini 779c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 780c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 781c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 782c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 783c50d8ae3SPaolo Bonzini } 784c50d8ae3SPaolo Bonzini 785c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 786c50d8ae3SPaolo Bonzini { 787c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 788c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 789c50d8ae3SPaolo Bonzini gfn_t gfn; 790c50d8ae3SPaolo Bonzini 791c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 792c50d8ae3SPaolo Bonzini gfn = sp->gfn; 793c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 794c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 7953bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 796c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 797c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 798c50d8ae3SPaolo Bonzini 799c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 800c50d8ae3SPaolo Bonzini } 801c50d8ae3SPaolo Bonzini 80229cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 803c50d8ae3SPaolo Bonzini { 804c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 805c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 806c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 807c50d8ae3SPaolo Bonzini } 808c50d8ae3SPaolo Bonzini 809c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 810c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 811c50d8ae3SPaolo Bonzini bool no_dirty_log) 812c50d8ae3SPaolo Bonzini { 813c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 814c50d8ae3SPaolo Bonzini 815c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 81691b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 81791b0d268SPaolo Bonzini return NULL; 818044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 81991b0d268SPaolo Bonzini return NULL; 820c50d8ae3SPaolo Bonzini 821c50d8ae3SPaolo Bonzini return slot; 822c50d8ae3SPaolo Bonzini } 823c50d8ae3SPaolo Bonzini 824c50d8ae3SPaolo Bonzini /* 825c50d8ae3SPaolo Bonzini * About rmap_head encoding: 826c50d8ae3SPaolo Bonzini * 827c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 828c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 829c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 830c50d8ae3SPaolo Bonzini */ 831c50d8ae3SPaolo Bonzini 832c50d8ae3SPaolo Bonzini /* 833c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 834c50d8ae3SPaolo Bonzini */ 835c50d8ae3SPaolo Bonzini static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte, 836c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 837c50d8ae3SPaolo Bonzini { 838c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 83913236e25SPeter Xu int count = 0; 840c50d8ae3SPaolo Bonzini 841c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 842805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 843c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 844c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 845805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 846c50d8ae3SPaolo Bonzini desc = mmu_alloc_pte_list_desc(vcpu); 847c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 848c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 84913236e25SPeter Xu desc->spte_count = 2; 850c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 851c50d8ae3SPaolo Bonzini ++count; 852c50d8ae3SPaolo Bonzini } else { 853805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 854c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 85513236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 856c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 857c6c4f961SLi RongQing if (!desc->more) { 858c50d8ae3SPaolo Bonzini desc->more = mmu_alloc_pte_list_desc(vcpu); 859c50d8ae3SPaolo Bonzini desc = desc->more; 86013236e25SPeter Xu desc->spte_count = 0; 861c6c4f961SLi RongQing break; 862c6c4f961SLi RongQing } 863c6c4f961SLi RongQing desc = desc->more; 864c50d8ae3SPaolo Bonzini } 86513236e25SPeter Xu count += desc->spte_count; 86613236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 867c50d8ae3SPaolo Bonzini } 868c50d8ae3SPaolo Bonzini return count; 869c50d8ae3SPaolo Bonzini } 870c50d8ae3SPaolo Bonzini 871c50d8ae3SPaolo Bonzini static void 872c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 873c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 874c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 875c50d8ae3SPaolo Bonzini { 87613236e25SPeter Xu int j = desc->spte_count - 1; 877c50d8ae3SPaolo Bonzini 878c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 879c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 88013236e25SPeter Xu desc->spte_count--; 88113236e25SPeter Xu if (desc->spte_count) 882c50d8ae3SPaolo Bonzini return; 883c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 884fe3c2b4cSMiaohe Lin rmap_head->val = 0; 885c50d8ae3SPaolo Bonzini else 886c50d8ae3SPaolo Bonzini if (prev_desc) 887c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 888c50d8ae3SPaolo Bonzini else 889c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 890c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 891c50d8ae3SPaolo Bonzini } 892c50d8ae3SPaolo Bonzini 893c50d8ae3SPaolo Bonzini static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 894c50d8ae3SPaolo Bonzini { 895c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 896c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 897c50d8ae3SPaolo Bonzini int i; 898c50d8ae3SPaolo Bonzini 899c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 900c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 901c50d8ae3SPaolo Bonzini BUG(); 902c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 903805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 904c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 905c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 906c50d8ae3SPaolo Bonzini BUG(); 907c50d8ae3SPaolo Bonzini } 908c50d8ae3SPaolo Bonzini rmap_head->val = 0; 909c50d8ae3SPaolo Bonzini } else { 910805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 911c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 912c50d8ae3SPaolo Bonzini prev_desc = NULL; 913c50d8ae3SPaolo Bonzini while (desc) { 91413236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 915c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 916c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 917c50d8ae3SPaolo Bonzini desc, i, prev_desc); 918c50d8ae3SPaolo Bonzini return; 919c50d8ae3SPaolo Bonzini } 920c50d8ae3SPaolo Bonzini } 921c50d8ae3SPaolo Bonzini prev_desc = desc; 922c50d8ae3SPaolo Bonzini desc = desc->more; 923c50d8ae3SPaolo Bonzini } 924c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 925c50d8ae3SPaolo Bonzini BUG(); 926c50d8ae3SPaolo Bonzini } 927c50d8ae3SPaolo Bonzini } 928c50d8ae3SPaolo Bonzini 92971f51d2cSMingwei Zhang static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 93071f51d2cSMingwei Zhang u64 *sptep) 931c50d8ae3SPaolo Bonzini { 93271f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 933c50d8ae3SPaolo Bonzini __pte_list_remove(sptep, rmap_head); 934c50d8ae3SPaolo Bonzini } 935c50d8ae3SPaolo Bonzini 936a75b5404SPeter Xu /* Return true if rmap existed, false otherwise */ 93771f51d2cSMingwei Zhang static bool pte_list_destroy(struct kvm *kvm, struct kvm_rmap_head *rmap_head) 938a75b5404SPeter Xu { 939a75b5404SPeter Xu struct pte_list_desc *desc, *next; 940a75b5404SPeter Xu int i; 941a75b5404SPeter Xu 942a75b5404SPeter Xu if (!rmap_head->val) 943a75b5404SPeter Xu return false; 944a75b5404SPeter Xu 945a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 94671f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 947a75b5404SPeter Xu goto out; 948a75b5404SPeter Xu } 949a75b5404SPeter Xu 950a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 951a75b5404SPeter Xu 952a75b5404SPeter Xu for (; desc; desc = next) { 953a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 95471f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 955a75b5404SPeter Xu next = desc->more; 956a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 957a75b5404SPeter Xu } 958a75b5404SPeter Xu out: 959a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 960a75b5404SPeter Xu rmap_head->val = 0; 961a75b5404SPeter Xu return true; 962a75b5404SPeter Xu } 963a75b5404SPeter Xu 9643bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 9653bcd0662SPeter Xu { 9663bcd0662SPeter Xu struct pte_list_desc *desc; 9673bcd0662SPeter Xu unsigned int count = 0; 9683bcd0662SPeter Xu 9693bcd0662SPeter Xu if (!rmap_head->val) 9703bcd0662SPeter Xu return 0; 9713bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 9723bcd0662SPeter Xu return 1; 9733bcd0662SPeter Xu 9743bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 9753bcd0662SPeter Xu 9763bcd0662SPeter Xu while (desc) { 9773bcd0662SPeter Xu count += desc->spte_count; 9783bcd0662SPeter Xu desc = desc->more; 9793bcd0662SPeter Xu } 9803bcd0662SPeter Xu 9813bcd0662SPeter Xu return count; 9823bcd0662SPeter Xu } 9833bcd0662SPeter Xu 98493e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 985269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 986c50d8ae3SPaolo Bonzini { 987c50d8ae3SPaolo Bonzini unsigned long idx; 988c50d8ae3SPaolo Bonzini 989c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 9903bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 991c50d8ae3SPaolo Bonzini } 992c50d8ae3SPaolo Bonzini 993c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 994c50d8ae3SPaolo Bonzini { 995356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 996c50d8ae3SPaolo Bonzini 997356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 99894ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 999c50d8ae3SPaolo Bonzini } 1000c50d8ae3SPaolo Bonzini 1001c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1002c50d8ae3SPaolo Bonzini { 1003601f8af0SDavid Matlack struct kvm_memslots *slots; 1004601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1005c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1006c50d8ae3SPaolo Bonzini gfn_t gfn; 1007c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1008c50d8ae3SPaolo Bonzini 100957354682SSean Christopherson sp = sptep_to_sp(spte); 1010c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt); 1011601f8af0SDavid Matlack 1012601f8af0SDavid Matlack /* 101368be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 101468be1306SDavid Matlack * so we have to determine which memslots to use based on context 101568be1306SDavid Matlack * information in sp->role. 1016601f8af0SDavid Matlack */ 1017601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1018601f8af0SDavid Matlack 1019601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 102093e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1021601f8af0SDavid Matlack 1022c50d8ae3SPaolo Bonzini __pte_list_remove(spte, rmap_head); 1023c50d8ae3SPaolo Bonzini } 1024c50d8ae3SPaolo Bonzini 1025c50d8ae3SPaolo Bonzini /* 1026c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1027c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1028c50d8ae3SPaolo Bonzini */ 1029c50d8ae3SPaolo Bonzini struct rmap_iterator { 1030c50d8ae3SPaolo Bonzini /* private fields */ 1031c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1032c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1033c50d8ae3SPaolo Bonzini }; 1034c50d8ae3SPaolo Bonzini 1035c50d8ae3SPaolo Bonzini /* 1036c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1037c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10380a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1039c50d8ae3SPaolo Bonzini * 1040c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1041c50d8ae3SPaolo Bonzini */ 1042c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1043c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1044c50d8ae3SPaolo Bonzini { 1045c50d8ae3SPaolo Bonzini u64 *sptep; 1046c50d8ae3SPaolo Bonzini 1047c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1048c50d8ae3SPaolo Bonzini return NULL; 1049c50d8ae3SPaolo Bonzini 1050c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1051c50d8ae3SPaolo Bonzini iter->desc = NULL; 1052c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1053c50d8ae3SPaolo Bonzini goto out; 1054c50d8ae3SPaolo Bonzini } 1055c50d8ae3SPaolo Bonzini 1056c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1057c50d8ae3SPaolo Bonzini iter->pos = 0; 1058c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1059c50d8ae3SPaolo Bonzini out: 1060c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1061c50d8ae3SPaolo Bonzini return sptep; 1062c50d8ae3SPaolo Bonzini } 1063c50d8ae3SPaolo Bonzini 1064c50d8ae3SPaolo Bonzini /* 1065c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1066c50d8ae3SPaolo Bonzini * 1067c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1068c50d8ae3SPaolo Bonzini */ 1069c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1070c50d8ae3SPaolo Bonzini { 1071c50d8ae3SPaolo Bonzini u64 *sptep; 1072c50d8ae3SPaolo Bonzini 1073c50d8ae3SPaolo Bonzini if (iter->desc) { 1074c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1075c50d8ae3SPaolo Bonzini ++iter->pos; 1076c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1077c50d8ae3SPaolo Bonzini if (sptep) 1078c50d8ae3SPaolo Bonzini goto out; 1079c50d8ae3SPaolo Bonzini } 1080c50d8ae3SPaolo Bonzini 1081c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1082c50d8ae3SPaolo Bonzini 1083c50d8ae3SPaolo Bonzini if (iter->desc) { 1084c50d8ae3SPaolo Bonzini iter->pos = 0; 1085c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1086c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1087c50d8ae3SPaolo Bonzini goto out; 1088c50d8ae3SPaolo Bonzini } 1089c50d8ae3SPaolo Bonzini } 1090c50d8ae3SPaolo Bonzini 1091c50d8ae3SPaolo Bonzini return NULL; 1092c50d8ae3SPaolo Bonzini out: 1093c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1094c50d8ae3SPaolo Bonzini return sptep; 1095c50d8ae3SPaolo Bonzini } 1096c50d8ae3SPaolo Bonzini 1097c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1098c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1099c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1100c50d8ae3SPaolo Bonzini 1101c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1102c50d8ae3SPaolo Bonzini { 110371f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11047fa2a347SSean Christopherson 11057fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1106c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1107c50d8ae3SPaolo Bonzini } 1108c50d8ae3SPaolo Bonzini 1109c50d8ae3SPaolo Bonzini 1110c50d8ae3SPaolo Bonzini static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) 1111c50d8ae3SPaolo Bonzini { 1112c50d8ae3SPaolo Bonzini if (is_large_pte(*sptep)) { 111357354682SSean Christopherson WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); 1114c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 1115c50d8ae3SPaolo Bonzini return true; 1116c50d8ae3SPaolo Bonzini } 1117c50d8ae3SPaolo Bonzini 1118c50d8ae3SPaolo Bonzini return false; 1119c50d8ae3SPaolo Bonzini } 1120c50d8ae3SPaolo Bonzini 1121c50d8ae3SPaolo Bonzini static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) 1122c50d8ae3SPaolo Bonzini { 1123c50d8ae3SPaolo Bonzini if (__drop_large_spte(vcpu->kvm, sptep)) { 112457354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 1125c50d8ae3SPaolo Bonzini 1126c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, 1127c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1128c50d8ae3SPaolo Bonzini } 1129c50d8ae3SPaolo Bonzini } 1130c50d8ae3SPaolo Bonzini 1131c50d8ae3SPaolo Bonzini /* 1132c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1133c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1134c50d8ae3SPaolo Bonzini * 1135c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1136c50d8ae3SPaolo Bonzini * protection: 1137c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1138c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1139c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1140c50d8ae3SPaolo Bonzini * shadow page. 1141c50d8ae3SPaolo Bonzini * 1142c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1143c50d8ae3SPaolo Bonzini */ 1144c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1145c50d8ae3SPaolo Bonzini { 1146c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1147c50d8ae3SPaolo Bonzini 1148c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1149706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1150c50d8ae3SPaolo Bonzini return false; 1151c50d8ae3SPaolo Bonzini 1152805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1153c50d8ae3SPaolo Bonzini 1154c50d8ae3SPaolo Bonzini if (pt_protect) 11555fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1156c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1157c50d8ae3SPaolo Bonzini 1158c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1159c50d8ae3SPaolo Bonzini } 1160c50d8ae3SPaolo Bonzini 11611346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1162c50d8ae3SPaolo Bonzini bool pt_protect) 1163c50d8ae3SPaolo Bonzini { 1164c50d8ae3SPaolo Bonzini u64 *sptep; 1165c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1166c50d8ae3SPaolo Bonzini bool flush = false; 1167c50d8ae3SPaolo Bonzini 1168c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1169c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1170c50d8ae3SPaolo Bonzini 1171c50d8ae3SPaolo Bonzini return flush; 1172c50d8ae3SPaolo Bonzini } 1173c50d8ae3SPaolo Bonzini 1174c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1175c50d8ae3SPaolo Bonzini { 1176c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1177c50d8ae3SPaolo Bonzini 1178805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1179c50d8ae3SPaolo Bonzini 1180c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1181c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1182c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1183c50d8ae3SPaolo Bonzini } 1184c50d8ae3SPaolo Bonzini 1185c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1186c50d8ae3SPaolo Bonzini { 1187c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1188c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1189c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1190c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1191c50d8ae3SPaolo Bonzini 1192c50d8ae3SPaolo Bonzini return was_writable; 1193c50d8ae3SPaolo Bonzini } 1194c50d8ae3SPaolo Bonzini 1195c50d8ae3SPaolo Bonzini /* 1196c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1197c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1198c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1199c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1200c50d8ae3SPaolo Bonzini */ 12010a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1202269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1203c50d8ae3SPaolo Bonzini { 1204c50d8ae3SPaolo Bonzini u64 *sptep; 1205c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1206c50d8ae3SPaolo Bonzini bool flush = false; 1207c50d8ae3SPaolo Bonzini 1208c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1209c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1210c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1211c50d8ae3SPaolo Bonzini else 1212c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1213c50d8ae3SPaolo Bonzini 1214c50d8ae3SPaolo Bonzini return flush; 1215c50d8ae3SPaolo Bonzini } 1216c50d8ae3SPaolo Bonzini 1217c50d8ae3SPaolo Bonzini /** 1218c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1219c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1220c50d8ae3SPaolo Bonzini * @slot: slot to protect 1221c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1222c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1223c50d8ae3SPaolo Bonzini * 122489212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1225c50d8ae3SPaolo Bonzini */ 1226c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1227c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1228c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1229c50d8ae3SPaolo Bonzini { 1230c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1231c50d8ae3SPaolo Bonzini 1232897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1233a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1234a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1235e2209710SBen Gardon 1236e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1237e2209710SBen Gardon return; 1238e2209710SBen Gardon 1239c50d8ae3SPaolo Bonzini while (mask) { 124093e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12413bae0459SSean Christopherson PG_LEVEL_4K, slot); 12421346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1243c50d8ae3SPaolo Bonzini 1244c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1245c50d8ae3SPaolo Bonzini mask &= mask - 1; 1246c50d8ae3SPaolo Bonzini } 1247c50d8ae3SPaolo Bonzini } 1248c50d8ae3SPaolo Bonzini 1249c50d8ae3SPaolo Bonzini /** 1250c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1251c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1252c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1253c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1254c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1255c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1256c50d8ae3SPaolo Bonzini * 1257c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1258c50d8ae3SPaolo Bonzini */ 1259a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1260c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1261c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1262c50d8ae3SPaolo Bonzini { 1263c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1264c50d8ae3SPaolo Bonzini 1265897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1266a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1267a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1268e2209710SBen Gardon 1269e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1270e2209710SBen Gardon return; 1271e2209710SBen Gardon 1272c50d8ae3SPaolo Bonzini while (mask) { 127393e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12743bae0459SSean Christopherson PG_LEVEL_4K, slot); 12750a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1276c50d8ae3SPaolo Bonzini 1277c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1278c50d8ae3SPaolo Bonzini mask &= mask - 1; 1279c50d8ae3SPaolo Bonzini } 1280c50d8ae3SPaolo Bonzini } 1281c50d8ae3SPaolo Bonzini 1282c50d8ae3SPaolo Bonzini /** 1283c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1284c50d8ae3SPaolo Bonzini * PT level pages. 1285c50d8ae3SPaolo Bonzini * 1286c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1287c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1288c50d8ae3SPaolo Bonzini * 128989212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 129089212919SKeqian Zhu * have such mappings. 1291c50d8ae3SPaolo Bonzini */ 1292c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1293c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1294c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1295c50d8ae3SPaolo Bonzini { 129689212919SKeqian Zhu /* 129789212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 129889212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 129989212919SKeqian Zhu * are split to 4K on the first write. 130089212919SKeqian Zhu * 130189212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 130289212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 130389212919SKeqian Zhu * pages. 130489212919SKeqian Zhu */ 130589212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 130689212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 130789212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 130889212919SKeqian Zhu 1309cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1310cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1311cb00a70bSDavid Matlack 131289212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 131389212919SKeqian Zhu 131489212919SKeqian Zhu /* Cross two large pages? */ 131589212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 131689212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 131789212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 131889212919SKeqian Zhu PG_LEVEL_2M); 131989212919SKeqian Zhu } 132089212919SKeqian Zhu 132189212919SKeqian Zhu /* Now handle 4K PTEs. */ 1322a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1323a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1324c50d8ae3SPaolo Bonzini else 1325c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1326c50d8ae3SPaolo Bonzini } 1327c50d8ae3SPaolo Bonzini 1328fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1329fb04a1edSPeter Xu { 13306dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1331fb04a1edSPeter Xu } 1332fb04a1edSPeter Xu 1333c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13343ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13353ad93562SKeqian Zhu int min_level) 1336c50d8ae3SPaolo Bonzini { 1337c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1338c50d8ae3SPaolo Bonzini int i; 1339c50d8ae3SPaolo Bonzini bool write_protected = false; 1340c50d8ae3SPaolo Bonzini 1341e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13423ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 134393e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13441346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1345c50d8ae3SPaolo Bonzini } 1346e2209710SBen Gardon } 1347c50d8ae3SPaolo Bonzini 1348897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 134946044f72SBen Gardon write_protected |= 13503ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 135146044f72SBen Gardon 1352c50d8ae3SPaolo Bonzini return write_protected; 1353c50d8ae3SPaolo Bonzini } 1354c50d8ae3SPaolo Bonzini 1355cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1356c50d8ae3SPaolo Bonzini { 1357c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1358c50d8ae3SPaolo Bonzini 1359c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 13603ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1361c50d8ae3SPaolo Bonzini } 1362c50d8ae3SPaolo Bonzini 13630a234f5dSSean Christopherson static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1364269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1365c50d8ae3SPaolo Bonzini { 136671f51d2cSMingwei Zhang return pte_list_destroy(kvm, rmap_head); 1367c50d8ae3SPaolo Bonzini } 1368c50d8ae3SPaolo Bonzini 13693039bcc7SSean Christopherson static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1370c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 13713039bcc7SSean Christopherson pte_t unused) 1372c50d8ae3SPaolo Bonzini { 13730a234f5dSSean Christopherson return kvm_zap_rmapp(kvm, rmap_head, slot); 1374c50d8ae3SPaolo Bonzini } 1375c50d8ae3SPaolo Bonzini 13763039bcc7SSean Christopherson static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1377c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 13783039bcc7SSean Christopherson pte_t pte) 1379c50d8ae3SPaolo Bonzini { 1380c50d8ae3SPaolo Bonzini u64 *sptep; 1381c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 138298a26b69SVihas Mak bool need_flush = false; 1383c50d8ae3SPaolo Bonzini u64 new_spte; 1384c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1385c50d8ae3SPaolo Bonzini 13863039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 13873039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1388c50d8ae3SPaolo Bonzini 1389c50d8ae3SPaolo Bonzini restart: 1390c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1391805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1392c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1393c50d8ae3SPaolo Bonzini 139498a26b69SVihas Mak need_flush = true; 1395c50d8ae3SPaolo Bonzini 13963039bcc7SSean Christopherson if (pte_write(pte)) { 139771f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 1398c50d8ae3SPaolo Bonzini goto restart; 1399c50d8ae3SPaolo Bonzini } else { 1400cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1401cb3eedabSPaolo Bonzini *sptep, new_pfn); 1402c50d8ae3SPaolo Bonzini 140371f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1404c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1405c50d8ae3SPaolo Bonzini } 1406c50d8ae3SPaolo Bonzini } 1407c50d8ae3SPaolo Bonzini 1408c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1409c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 141098a26b69SVihas Mak return false; 1411c50d8ae3SPaolo Bonzini } 1412c50d8ae3SPaolo Bonzini 1413c50d8ae3SPaolo Bonzini return need_flush; 1414c50d8ae3SPaolo Bonzini } 1415c50d8ae3SPaolo Bonzini 1416c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1417c50d8ae3SPaolo Bonzini /* input fields. */ 1418269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1419c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1420c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1421c50d8ae3SPaolo Bonzini int start_level; 1422c50d8ae3SPaolo Bonzini int end_level; 1423c50d8ae3SPaolo Bonzini 1424c50d8ae3SPaolo Bonzini /* output fields. */ 1425c50d8ae3SPaolo Bonzini gfn_t gfn; 1426c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1427c50d8ae3SPaolo Bonzini int level; 1428c50d8ae3SPaolo Bonzini 1429c50d8ae3SPaolo Bonzini /* private field. */ 1430c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1431c50d8ae3SPaolo Bonzini }; 1432c50d8ae3SPaolo Bonzini 1433c50d8ae3SPaolo Bonzini static void 1434c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1435c50d8ae3SPaolo Bonzini { 1436c50d8ae3SPaolo Bonzini iterator->level = level; 1437c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 143893e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 143993e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1440c50d8ae3SPaolo Bonzini } 1441c50d8ae3SPaolo Bonzini 1442c50d8ae3SPaolo Bonzini static void 1443c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1444269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1445c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1446c50d8ae3SPaolo Bonzini { 1447c50d8ae3SPaolo Bonzini iterator->slot = slot; 1448c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1449c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1450c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1451c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1452c50d8ae3SPaolo Bonzini 1453c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1454c50d8ae3SPaolo Bonzini } 1455c50d8ae3SPaolo Bonzini 1456c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1457c50d8ae3SPaolo Bonzini { 1458c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1459c50d8ae3SPaolo Bonzini } 1460c50d8ae3SPaolo Bonzini 1461c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1462c50d8ae3SPaolo Bonzini { 14636ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1464c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 14656ba1e04fSVipin Sharma 14666ba1e04fSVipin Sharma if (iterator->rmap->val) 1467c50d8ae3SPaolo Bonzini return; 1468c50d8ae3SPaolo Bonzini } 1469c50d8ae3SPaolo Bonzini 1470c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1471c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1472c50d8ae3SPaolo Bonzini return; 1473c50d8ae3SPaolo Bonzini } 1474c50d8ae3SPaolo Bonzini 1475c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1476c50d8ae3SPaolo Bonzini } 1477c50d8ae3SPaolo Bonzini 1478c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1479c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1480c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1481c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1482c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1483c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1484c50d8ae3SPaolo Bonzini 14853039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1486c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 14873039bcc7SSean Christopherson int level, pte_t pte); 1488c1b91493SSean Christopherson 14893039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 14903039bcc7SSean Christopherson struct kvm_gfn_range *range, 1491c1b91493SSean Christopherson rmap_handler_t handler) 1492c50d8ae3SPaolo Bonzini { 1493c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 14943039bcc7SSean Christopherson bool ret = false; 1495c50d8ae3SPaolo Bonzini 14963039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 14973039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 14983039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 14993039bcc7SSean Christopherson iterator.level, range->pte); 1500c50d8ae3SPaolo Bonzini 1501c50d8ae3SPaolo Bonzini return ret; 1502c50d8ae3SPaolo Bonzini } 1503c50d8ae3SPaolo Bonzini 15043039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1505c50d8ae3SPaolo Bonzini { 1506e2209710SBen Gardon bool flush = false; 1507c50d8ae3SPaolo Bonzini 1508e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15093039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp); 1510063afacdSBen Gardon 1511897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1512c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1513063afacdSBen Gardon 15143039bcc7SSean Christopherson return flush; 1515c50d8ae3SPaolo Bonzini } 1516c50d8ae3SPaolo Bonzini 15173039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1518c50d8ae3SPaolo Bonzini { 1519e2209710SBen Gardon bool flush = false; 15201d8dd6b3SBen Gardon 1521e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15223039bcc7SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp); 15231d8dd6b3SBen Gardon 1524897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15253039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15261d8dd6b3SBen Gardon 15273039bcc7SSean Christopherson return flush; 1528c50d8ae3SPaolo Bonzini } 1529c50d8ae3SPaolo Bonzini 15303039bcc7SSean Christopherson static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1531c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15323039bcc7SSean Christopherson pte_t unused) 1533c50d8ae3SPaolo Bonzini { 1534c50d8ae3SPaolo Bonzini u64 *sptep; 15353f649ab7SKees Cook struct rmap_iterator iter; 1536c50d8ae3SPaolo Bonzini int young = 0; 1537c50d8ae3SPaolo Bonzini 1538c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1539c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1540c50d8ae3SPaolo Bonzini 1541c50d8ae3SPaolo Bonzini return young; 1542c50d8ae3SPaolo Bonzini } 1543c50d8ae3SPaolo Bonzini 15443039bcc7SSean Christopherson static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1545c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15463039bcc7SSean Christopherson int level, pte_t unused) 1547c50d8ae3SPaolo Bonzini { 1548c50d8ae3SPaolo Bonzini u64 *sptep; 1549c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1550c50d8ae3SPaolo Bonzini 1551c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1552c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 155398a26b69SVihas Mak return true; 155498a26b69SVihas Mak return false; 1555c50d8ae3SPaolo Bonzini } 1556c50d8ae3SPaolo Bonzini 1557c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1558c50d8ae3SPaolo Bonzini 15598a9f566aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 15608a9f566aSDavid Matlack u64 *spte, gfn_t gfn) 1561c50d8ae3SPaolo Bonzini { 1562c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 156368be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 156468be1306SDavid Matlack int rmap_count; 1565c50d8ae3SPaolo Bonzini 156657354682SSean Christopherson sp = sptep_to_sp(spte); 156768be1306SDavid Matlack kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn); 156893e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 156968be1306SDavid Matlack rmap_count = pte_list_add(vcpu, spte, rmap_head); 1570c50d8ae3SPaolo Bonzini 157168be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 15723039bcc7SSean Christopherson kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0)); 157368be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 157468be1306SDavid Matlack vcpu->kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 157568be1306SDavid Matlack } 1576c50d8ae3SPaolo Bonzini } 1577c50d8ae3SPaolo Bonzini 15783039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1579c50d8ae3SPaolo Bonzini { 1580e2209710SBen Gardon bool young = false; 1581f8e14497SBen Gardon 1582e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15833039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp); 15843039bcc7SSean Christopherson 1585897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15863039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1587f8e14497SBen Gardon 1588f8e14497SBen Gardon return young; 1589c50d8ae3SPaolo Bonzini } 1590c50d8ae3SPaolo Bonzini 15913039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1592c50d8ae3SPaolo Bonzini { 1593e2209710SBen Gardon bool young = false; 1594f8e14497SBen Gardon 1595e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 15963039bcc7SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp); 15973039bcc7SSean Christopherson 1598897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15993039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1600f8e14497SBen Gardon 1601f8e14497SBen Gardon return young; 1602c50d8ae3SPaolo Bonzini } 1603c50d8ae3SPaolo Bonzini 1604c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1605c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1606c50d8ae3SPaolo Bonzini { 1607c50d8ae3SPaolo Bonzini u64 *pos; 1608c50d8ae3SPaolo Bonzini u64 *end; 1609c50d8ae3SPaolo Bonzini 1610c50d8ae3SPaolo Bonzini for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) 1611c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1612c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1613c50d8ae3SPaolo Bonzini pos, *pos); 1614c50d8ae3SPaolo Bonzini return 0; 1615c50d8ae3SPaolo Bonzini } 1616c50d8ae3SPaolo Bonzini return 1; 1617c50d8ae3SPaolo Bonzini } 1618c50d8ae3SPaolo Bonzini #endif 1619c50d8ae3SPaolo Bonzini 1620c50d8ae3SPaolo Bonzini /* 1621c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1622c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1623c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1624c50d8ae3SPaolo Bonzini * faster 1625c50d8ae3SPaolo Bonzini */ 1626d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1627c50d8ae3SPaolo Bonzini { 1628c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1629c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1630c50d8ae3SPaolo Bonzini } 1631c50d8ae3SPaolo Bonzini 163287654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1633c50d8ae3SPaolo Bonzini { 1634c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1635c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1636c50d8ae3SPaolo Bonzini list_del(&sp->link); 1637c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1638c50d8ae3SPaolo Bonzini if (!sp->role.direct) 1639c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->gfns); 1640c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1641c50d8ae3SPaolo Bonzini } 1642c50d8ae3SPaolo Bonzini 1643c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1644c50d8ae3SPaolo Bonzini { 1645c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1646c50d8ae3SPaolo Bonzini } 1647c50d8ae3SPaolo Bonzini 1648c50d8ae3SPaolo Bonzini static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, 1649c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1650c50d8ae3SPaolo Bonzini { 1651c50d8ae3SPaolo Bonzini if (!parent_pte) 1652c50d8ae3SPaolo Bonzini return; 1653c50d8ae3SPaolo Bonzini 1654c50d8ae3SPaolo Bonzini pte_list_add(vcpu, parent_pte, &sp->parent_ptes); 1655c50d8ae3SPaolo Bonzini } 1656c50d8ae3SPaolo Bonzini 1657c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1658c50d8ae3SPaolo Bonzini u64 *parent_pte) 1659c50d8ae3SPaolo Bonzini { 1660c50d8ae3SPaolo Bonzini __pte_list_remove(parent_pte, &sp->parent_ptes); 1661c50d8ae3SPaolo Bonzini } 1662c50d8ae3SPaolo Bonzini 1663c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1664c50d8ae3SPaolo Bonzini u64 *parent_pte) 1665c50d8ae3SPaolo Bonzini { 1666c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1667c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1668c50d8ae3SPaolo Bonzini } 1669c50d8ae3SPaolo Bonzini 1670c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1671c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1672c50d8ae3SPaolo Bonzini { 1673c50d8ae3SPaolo Bonzini u64 *sptep; 1674c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1675c50d8ae3SPaolo Bonzini 1676c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1677c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1678c50d8ae3SPaolo Bonzini } 1679c50d8ae3SPaolo Bonzini } 1680c50d8ae3SPaolo Bonzini 1681c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1682c50d8ae3SPaolo Bonzini { 1683c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1684c50d8ae3SPaolo Bonzini unsigned int index; 1685c50d8ae3SPaolo Bonzini 168657354682SSean Christopherson sp = sptep_to_sp(spte); 1687c50d8ae3SPaolo Bonzini index = spte - sp->spt; 1688c50d8ae3SPaolo Bonzini if (__test_and_set_bit(index, sp->unsync_child_bitmap)) 1689c50d8ae3SPaolo Bonzini return; 1690c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1691c50d8ae3SPaolo Bonzini return; 1692c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1693c50d8ae3SPaolo Bonzini } 1694c50d8ae3SPaolo Bonzini 1695c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1696c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1697c50d8ae3SPaolo Bonzini { 1698c3e5e415SLai Jiangshan return -1; 1699c50d8ae3SPaolo Bonzini } 1700c50d8ae3SPaolo Bonzini 1701c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1702c50d8ae3SPaolo Bonzini 1703c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1704c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1705c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1706c50d8ae3SPaolo Bonzini unsigned int idx; 1707c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1708c50d8ae3SPaolo Bonzini unsigned int nr; 1709c50d8ae3SPaolo Bonzini }; 1710c50d8ae3SPaolo Bonzini 1711c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1712c50d8ae3SPaolo Bonzini int idx) 1713c50d8ae3SPaolo Bonzini { 1714c50d8ae3SPaolo Bonzini int i; 1715c50d8ae3SPaolo Bonzini 1716c50d8ae3SPaolo Bonzini if (sp->unsync) 1717c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1718c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1719c50d8ae3SPaolo Bonzini return 0; 1720c50d8ae3SPaolo Bonzini 1721c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1722c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1723c50d8ae3SPaolo Bonzini pvec->nr++; 1724c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1725c50d8ae3SPaolo Bonzini } 1726c50d8ae3SPaolo Bonzini 1727c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1728c50d8ae3SPaolo Bonzini { 1729c50d8ae3SPaolo Bonzini --sp->unsync_children; 1730c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1731c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1732c50d8ae3SPaolo Bonzini } 1733c50d8ae3SPaolo Bonzini 1734c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1735c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1736c50d8ae3SPaolo Bonzini { 1737c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1738c50d8ae3SPaolo Bonzini 1739c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1740c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1741c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1742c50d8ae3SPaolo Bonzini 1743c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1744c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1745c50d8ae3SPaolo Bonzini continue; 1746c50d8ae3SPaolo Bonzini } 1747c50d8ae3SPaolo Bonzini 17482ca3129eSSean Christopherson child = to_shadow_page(ent & SPTE_BASE_ADDR_MASK); 1749c50d8ae3SPaolo Bonzini 1750c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1751c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1752c50d8ae3SPaolo Bonzini return -ENOSPC; 1753c50d8ae3SPaolo Bonzini 1754c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1755c50d8ae3SPaolo Bonzini if (!ret) { 1756c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1757c50d8ae3SPaolo Bonzini continue; 1758c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1759c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1760c50d8ae3SPaolo Bonzini } else 1761c50d8ae3SPaolo Bonzini return ret; 1762c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1763c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1764c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1765c50d8ae3SPaolo Bonzini return -ENOSPC; 1766c50d8ae3SPaolo Bonzini } else 1767c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1768c50d8ae3SPaolo Bonzini } 1769c50d8ae3SPaolo Bonzini 1770c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1771c50d8ae3SPaolo Bonzini } 1772c50d8ae3SPaolo Bonzini 1773c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 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 pvec->nr = 0; 1779c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1780c50d8ae3SPaolo Bonzini return 0; 1781c50d8ae3SPaolo Bonzini 1782c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1783c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1784c50d8ae3SPaolo Bonzini } 1785c50d8ae3SPaolo Bonzini 1786c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1787c50d8ae3SPaolo Bonzini { 1788c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1789c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1790c50d8ae3SPaolo Bonzini sp->unsync = 0; 1791c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1792c50d8ae3SPaolo Bonzini } 1793c50d8ae3SPaolo Bonzini 1794c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1795c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1796c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1797c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1798c50d8ae3SPaolo Bonzini 1799767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1800767d8d8dSLai Jiangshan { 1801767d8d8dSLai Jiangshan if (sp->role.direct) 1802767d8d8dSLai Jiangshan return false; 1803767d8d8dSLai Jiangshan 180484e5ffd0SLai Jiangshan if (sp->role.passthrough) 180584e5ffd0SLai Jiangshan return false; 180684e5ffd0SLai Jiangshan 1807767d8d8dSLai Jiangshan return true; 1808767d8d8dSLai Jiangshan } 1809767d8d8dSLai Jiangshan 1810ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1811ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1812c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1813c50d8ae3SPaolo Bonzini } else 1814c50d8ae3SPaolo Bonzini 1815767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1816ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1817ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1818767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1819c50d8ae3SPaolo Bonzini 18208d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1821c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1822c50d8ae3SPaolo Bonzini { 1823c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1824c3e5e415SLai Jiangshan 18258d5678a7SHou Wenlong if (ret < 0) 1826c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18278d5678a7SHou Wenlong return ret; 1828c50d8ae3SPaolo Bonzini } 1829c50d8ae3SPaolo Bonzini 1830c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1831c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1832c50d8ae3SPaolo Bonzini bool remote_flush) 1833c50d8ae3SPaolo Bonzini { 1834c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1835c50d8ae3SPaolo Bonzini return false; 1836c50d8ae3SPaolo Bonzini 1837c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1838c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1839c50d8ae3SPaolo Bonzini else 1840c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1841c50d8ae3SPaolo Bonzini return true; 1842c50d8ae3SPaolo Bonzini } 1843c50d8ae3SPaolo Bonzini 1844c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1845c50d8ae3SPaolo Bonzini { 1846a955cad8SSean Christopherson if (sp->role.invalid) 1847a955cad8SSean Christopherson return true; 1848a955cad8SSean Christopherson 1849a955cad8SSean Christopherson /* TDP MMU pages due not use the MMU generation. */ 1850a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1851c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1852c50d8ae3SPaolo Bonzini } 1853c50d8ae3SPaolo Bonzini 1854c50d8ae3SPaolo Bonzini struct mmu_page_path { 1855c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1856c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1857c50d8ae3SPaolo Bonzini }; 1858c50d8ae3SPaolo Bonzini 1859c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1860c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1861c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1862c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1863c50d8ae3SPaolo Bonzini 1864c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1865c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1866c50d8ae3SPaolo Bonzini int i) 1867c50d8ae3SPaolo Bonzini { 1868c50d8ae3SPaolo Bonzini int n; 1869c50d8ae3SPaolo Bonzini 1870c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1871c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1872c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1873c50d8ae3SPaolo Bonzini int level = sp->role.level; 1874c50d8ae3SPaolo Bonzini 1875c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 18763bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1877c50d8ae3SPaolo Bonzini break; 1878c50d8ae3SPaolo Bonzini 1879c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1880c50d8ae3SPaolo Bonzini } 1881c50d8ae3SPaolo Bonzini 1882c50d8ae3SPaolo Bonzini return n; 1883c50d8ae3SPaolo Bonzini } 1884c50d8ae3SPaolo Bonzini 1885c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1886c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1887c50d8ae3SPaolo Bonzini { 1888c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1889c50d8ae3SPaolo Bonzini int level; 1890c50d8ae3SPaolo Bonzini 1891c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1892c50d8ae3SPaolo Bonzini return 0; 1893c50d8ae3SPaolo Bonzini 1894c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1895c50d8ae3SPaolo Bonzini 1896c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1897c50d8ae3SPaolo Bonzini level = sp->role.level; 18983bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1899c50d8ae3SPaolo Bonzini 1900c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1901c50d8ae3SPaolo Bonzini 1902c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1903c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1904c50d8ae3SPaolo Bonzini */ 1905c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1906c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1907c50d8ae3SPaolo Bonzini } 1908c50d8ae3SPaolo Bonzini 1909c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1910c50d8ae3SPaolo Bonzini { 1911c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1912c50d8ae3SPaolo Bonzini unsigned int level = 0; 1913c50d8ae3SPaolo Bonzini 1914c50d8ae3SPaolo Bonzini do { 1915c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1916c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1917c50d8ae3SPaolo Bonzini if (!sp) 1918c50d8ae3SPaolo Bonzini return; 1919c50d8ae3SPaolo Bonzini 1920c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1921c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1922c50d8ae3SPaolo Bonzini level++; 1923c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1924c50d8ae3SPaolo Bonzini } 1925c50d8ae3SPaolo Bonzini 192665855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 192765855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1928c50d8ae3SPaolo Bonzini { 1929c50d8ae3SPaolo Bonzini int i; 1930c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1931c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1932c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1933c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1934c50d8ae3SPaolo Bonzini bool flush = false; 1935c50d8ae3SPaolo Bonzini 1936c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 1937c50d8ae3SPaolo Bonzini bool protected = false; 1938c50d8ae3SPaolo Bonzini 1939c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 1940cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 1941c50d8ae3SPaolo Bonzini 1942c50d8ae3SPaolo Bonzini if (protected) { 19435591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 1944c50d8ae3SPaolo Bonzini flush = false; 1945c50d8ae3SPaolo Bonzini } 1946c50d8ae3SPaolo Bonzini 1947c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 1948479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 19498d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 1950c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 1951c50d8ae3SPaolo Bonzini } 1952531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 1953c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 195465855ed8SLai Jiangshan if (!can_yield) { 195565855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 195665855ed8SLai Jiangshan return -EINTR; 195765855ed8SLai Jiangshan } 195865855ed8SLai Jiangshan 1959531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 1960c50d8ae3SPaolo Bonzini flush = false; 1961c50d8ae3SPaolo Bonzini } 1962c50d8ae3SPaolo Bonzini } 1963c50d8ae3SPaolo Bonzini 1964c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 196565855ed8SLai Jiangshan return 0; 1966c50d8ae3SPaolo Bonzini } 1967c50d8ae3SPaolo Bonzini 1968c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 1969c50d8ae3SPaolo Bonzini { 1970c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 1971c50d8ae3SPaolo Bonzini } 1972c50d8ae3SPaolo Bonzini 1973c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 1974c50d8ae3SPaolo Bonzini { 197557354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 1976c50d8ae3SPaolo Bonzini } 1977c50d8ae3SPaolo Bonzini 197894c81364SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm_vcpu *vcpu, 197994c81364SDavid Matlack gfn_t gfn, 198094c81364SDavid Matlack struct hlist_head *sp_list, 19812e65e842SDavid Matlack union kvm_mmu_page_role role) 1982c50d8ae3SPaolo Bonzini { 1983c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 19848d5678a7SHou Wenlong int ret; 1985c50d8ae3SPaolo Bonzini int collisions = 0; 1986c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1987c50d8ae3SPaolo Bonzini 1988ac101b7cSSean Christopherson for_each_valid_sp(vcpu->kvm, sp, sp_list) { 1989c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 1990c50d8ae3SPaolo Bonzini collisions++; 1991c50d8ae3SPaolo Bonzini continue; 1992c50d8ae3SPaolo Bonzini } 1993c50d8ae3SPaolo Bonzini 1994ddc16abbSSean Christopherson if (sp->role.word != role.word) { 1995ddc16abbSSean Christopherson /* 1996ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 1997ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 1998ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 1999ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2000ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2001ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2002ddc16abbSSean Christopherson * upper-level page will be write-protected. 2003ddc16abbSSean Christopherson */ 20042e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 2005ddc16abbSSean Christopherson kvm_mmu_prepare_zap_page(vcpu->kvm, sp, 2006ddc16abbSSean Christopherson &invalid_list); 2007c50d8ae3SPaolo Bonzini continue; 2008ddc16abbSSean Christopherson } 2009c50d8ae3SPaolo Bonzini 2010bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2011bb924ca6SDavid Matlack if (sp->role.direct) 201294c81364SDavid Matlack goto out; 2013fb58a9c3SSean Christopherson 2014c50d8ae3SPaolo Bonzini if (sp->unsync) { 201507dc4f35SSean Christopherson /* 2016479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 201707dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 201807dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 201907dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 202007dc4f35SSean Christopherson * overhead of write protection is not incurred until the 202107dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 202207dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 202307dc4f35SSean Christopherson * 202407dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 202507dc4f35SSean Christopherson * in order to rebuild it. 2026c50d8ae3SPaolo Bonzini */ 20278d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 20288d5678a7SHou Wenlong if (ret < 0) 2029c50d8ae3SPaolo Bonzini break; 2030c50d8ae3SPaolo Bonzini 2031c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 20328d5678a7SHou Wenlong if (ret > 0) 2033c3e5e415SLai Jiangshan kvm_flush_remote_tlbs(vcpu->kvm); 2034c50d8ae3SPaolo Bonzini } 2035c50d8ae3SPaolo Bonzini 2036c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2037fb58a9c3SSean Christopherson 2038c50d8ae3SPaolo Bonzini goto out; 2039c50d8ae3SPaolo Bonzini } 2040c50d8ae3SPaolo Bonzini 204194c81364SDavid Matlack sp = NULL; 2042c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_cache_miss; 2043c50d8ae3SPaolo Bonzini 204494c81364SDavid Matlack out: 204594c81364SDavid Matlack kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); 204694c81364SDavid Matlack 204794c81364SDavid Matlack if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions) 204894c81364SDavid Matlack vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions; 204994c81364SDavid Matlack return sp; 205094c81364SDavid Matlack } 205194c81364SDavid Matlack 205294c81364SDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm_vcpu *vcpu, 205394c81364SDavid Matlack gfn_t gfn, 205494c81364SDavid Matlack struct hlist_head *sp_list, 205594c81364SDavid Matlack union kvm_mmu_page_role role) 205694c81364SDavid Matlack { 2057c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2058c306aec8SDavid Matlack 2059c306aec8SDavid Matlack sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache); 2060c306aec8SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache); 2061c306aec8SDavid Matlack if (!role.direct) 2062c306aec8SDavid Matlack sp->gfns = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache); 2063c306aec8SDavid Matlack 2064c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2065c306aec8SDavid Matlack 2066c306aec8SDavid Matlack /* 2067c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2068c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2069c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2070c306aec8SDavid Matlack */ 2071c306aec8SDavid Matlack sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; 2072c306aec8SDavid Matlack list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); 2073c306aec8SDavid Matlack kvm_mod_used_mmu_pages(vcpu->kvm, +1); 2074c50d8ae3SPaolo Bonzini 2075c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2076c50d8ae3SPaolo Bonzini sp->role = role; 2077ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2078*be911771SDavid Matlack if (sp_has_gptes(sp)) 2079c50d8ae3SPaolo Bonzini account_shadowed(vcpu->kvm, sp); 2080ddc16abbSSean Christopherson 208194c81364SDavid Matlack return sp; 208294c81364SDavid Matlack } 208394c81364SDavid Matlack 208487654643SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 208587654643SDavid Matlack gfn_t gfn, 208694c81364SDavid Matlack union kvm_mmu_page_role role) 208794c81364SDavid Matlack { 208894c81364SDavid Matlack struct hlist_head *sp_list; 208994c81364SDavid Matlack struct kvm_mmu_page *sp; 209094c81364SDavid Matlack bool created = false; 209194c81364SDavid Matlack 209294c81364SDavid Matlack sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 209394c81364SDavid Matlack 209494c81364SDavid Matlack sp = kvm_mmu_find_shadow_page(vcpu, gfn, sp_list, role); 209594c81364SDavid Matlack if (!sp) { 209694c81364SDavid Matlack created = true; 209794c81364SDavid Matlack sp = kvm_mmu_alloc_shadow_page(vcpu, gfn, sp_list, role); 209894c81364SDavid Matlack } 209994c81364SDavid Matlack 210094c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2101c50d8ae3SPaolo Bonzini return sp; 2102c50d8ae3SPaolo Bonzini } 2103c50d8ae3SPaolo Bonzini 21042e65e842SDavid Matlack static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, unsigned int access) 21052e65e842SDavid Matlack { 21062e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 21072e65e842SDavid Matlack union kvm_mmu_page_role role; 21082e65e842SDavid Matlack 21092e65e842SDavid Matlack role = parent_sp->role; 21102e65e842SDavid Matlack role.level--; 21112e65e842SDavid Matlack role.access = access; 21122e65e842SDavid Matlack role.direct = direct; 21132e65e842SDavid Matlack role.passthrough = 0; 21142e65e842SDavid Matlack 21152e65e842SDavid Matlack /* 21162e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 21172e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 21182e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 21192e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 21202e65e842SDavid Matlack * requires extra bookkeeping in the role. 21212e65e842SDavid Matlack * 21222e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 21232e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 21242e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 21252e65e842SDavid Matlack * the address space each maps. 21262e65e842SDavid Matlack * 21272e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 21282e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 21292e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 21302e65e842SDavid Matlack * 21312e65e842SDavid Matlack * Note, the 4 PAE page directories are pre-allocated and the quadrant 21322e65e842SDavid Matlack * assigned in mmu_alloc_root(). So only page tables need to be handled 21332e65e842SDavid Matlack * here. 21342e65e842SDavid Matlack */ 21352e65e842SDavid Matlack if (role.has_4_byte_gpte) { 21362e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 21372e65e842SDavid Matlack role.quadrant = (sptep - parent_sp->spt) % 2; 21382e65e842SDavid Matlack } 21392e65e842SDavid Matlack 21402e65e842SDavid Matlack return role; 21412e65e842SDavid Matlack } 21422e65e842SDavid Matlack 21432e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 21442e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 21452e65e842SDavid Matlack bool direct, unsigned int access) 21462e65e842SDavid Matlack { 21472e65e842SDavid Matlack union kvm_mmu_page_role role; 21482e65e842SDavid Matlack 21492e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 215087654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 21512e65e842SDavid Matlack } 21522e65e842SDavid Matlack 2153c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2154c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2155c50d8ae3SPaolo Bonzini u64 addr) 2156c50d8ae3SPaolo Bonzini { 2157c50d8ae3SPaolo Bonzini iterator->addr = addr; 2158c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2159a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2160c50d8ae3SPaolo Bonzini 216112ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 21624d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2163347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 216412ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2165c50d8ae3SPaolo Bonzini 2166c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2167c50d8ae3SPaolo Bonzini /* 2168c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2169c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2170c50d8ae3SPaolo Bonzini */ 2171b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2172c50d8ae3SPaolo Bonzini 2173c50d8ae3SPaolo Bonzini iterator->shadow_addr 2174c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 21752ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2176c50d8ae3SPaolo Bonzini --iterator->level; 2177c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2178c50d8ae3SPaolo Bonzini iterator->level = 0; 2179c50d8ae3SPaolo Bonzini } 2180c50d8ae3SPaolo Bonzini } 2181c50d8ae3SPaolo Bonzini 2182c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2183c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2184c50d8ae3SPaolo Bonzini { 2185b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2186c50d8ae3SPaolo Bonzini addr); 2187c50d8ae3SPaolo Bonzini } 2188c50d8ae3SPaolo Bonzini 2189c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2190c50d8ae3SPaolo Bonzini { 21913bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2192c50d8ae3SPaolo Bonzini return false; 2193c50d8ae3SPaolo Bonzini 21942ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2195c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2196c50d8ae3SPaolo Bonzini return true; 2197c50d8ae3SPaolo Bonzini } 2198c50d8ae3SPaolo Bonzini 2199c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2200c50d8ae3SPaolo Bonzini u64 spte) 2201c50d8ae3SPaolo Bonzini { 22023e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2203c50d8ae3SPaolo Bonzini iterator->level = 0; 2204c50d8ae3SPaolo Bonzini return; 2205c50d8ae3SPaolo Bonzini } 2206c50d8ae3SPaolo Bonzini 22072ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2208c50d8ae3SPaolo Bonzini --iterator->level; 2209c50d8ae3SPaolo Bonzini } 2210c50d8ae3SPaolo Bonzini 2211c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2212c50d8ae3SPaolo Bonzini { 2213c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2214c50d8ae3SPaolo Bonzini } 2215c50d8ae3SPaolo Bonzini 2216c50d8ae3SPaolo Bonzini static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 2217c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 2218c50d8ae3SPaolo Bonzini { 2219c50d8ae3SPaolo Bonzini u64 spte; 2220c50d8ae3SPaolo Bonzini 2221c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2222c50d8ae3SPaolo Bonzini 2223cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2224c50d8ae3SPaolo Bonzini 2225c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2226c50d8ae3SPaolo Bonzini 2227c50d8ae3SPaolo Bonzini mmu_page_add_parent_pte(vcpu, sp, sptep); 2228c50d8ae3SPaolo Bonzini 2229c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2230c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2231c50d8ae3SPaolo Bonzini } 2232c50d8ae3SPaolo Bonzini 2233c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2234c50d8ae3SPaolo Bonzini unsigned direct_access) 2235c50d8ae3SPaolo Bonzini { 2236c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2237c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2238c50d8ae3SPaolo Bonzini 2239c50d8ae3SPaolo Bonzini /* 2240c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2241c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2242c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2243c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2244c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2245c50d8ae3SPaolo Bonzini */ 22462ca3129eSSean Christopherson child = to_shadow_page(*sptep & SPTE_BASE_ADDR_MASK); 2247c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2248c50d8ae3SPaolo Bonzini return; 2249c50d8ae3SPaolo Bonzini 2250c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2251c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2252c50d8ae3SPaolo Bonzini } 2253c50d8ae3SPaolo Bonzini } 2254c50d8ae3SPaolo Bonzini 22552de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 22562de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 22572de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2258c50d8ae3SPaolo Bonzini { 2259c50d8ae3SPaolo Bonzini u64 pte; 2260c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2261c50d8ae3SPaolo Bonzini 2262c50d8ae3SPaolo Bonzini pte = *spte; 2263c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2264c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2265c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2266c50d8ae3SPaolo Bonzini } else { 22672ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2268c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 22692de4085cSBen Gardon 22702de4085cSBen Gardon /* 22712de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 22722de4085cSBen Gardon * unlikely to be used again in the near future. This 22732de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 22742de4085cSBen Gardon */ 22752de4085cSBen Gardon if (tdp_enabled && invalid_list && 22762de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 22772de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 22782de4085cSBen Gardon invalid_list); 2279c50d8ae3SPaolo Bonzini } 2280ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2281c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2282ace569e0SSean Christopherson } 22832de4085cSBen Gardon return 0; 2284c50d8ae3SPaolo Bonzini } 2285c50d8ae3SPaolo Bonzini 22862de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 22872de4085cSBen Gardon struct kvm_mmu_page *sp, 22882de4085cSBen Gardon struct list_head *invalid_list) 2289c50d8ae3SPaolo Bonzini { 22902de4085cSBen Gardon int zapped = 0; 2291c50d8ae3SPaolo Bonzini unsigned i; 2292c50d8ae3SPaolo Bonzini 22932ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 22942de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 22952de4085cSBen Gardon 22962de4085cSBen Gardon return zapped; 2297c50d8ae3SPaolo Bonzini } 2298c50d8ae3SPaolo Bonzini 229961827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2300c50d8ae3SPaolo Bonzini { 2301c50d8ae3SPaolo Bonzini u64 *sptep; 2302c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2303c50d8ae3SPaolo Bonzini 2304c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2305c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2306c50d8ae3SPaolo Bonzini } 2307c50d8ae3SPaolo Bonzini 2308c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2309c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2310c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2311c50d8ae3SPaolo Bonzini { 2312c50d8ae3SPaolo Bonzini int i, zapped = 0; 2313c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2314c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2315c50d8ae3SPaolo Bonzini 23163bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2317c50d8ae3SPaolo Bonzini return 0; 2318c50d8ae3SPaolo Bonzini 2319c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2320c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2321c50d8ae3SPaolo Bonzini 2322c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2323c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2324c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2325c50d8ae3SPaolo Bonzini zapped++; 2326c50d8ae3SPaolo Bonzini } 2327c50d8ae3SPaolo Bonzini } 2328c50d8ae3SPaolo Bonzini 2329c50d8ae3SPaolo Bonzini return zapped; 2330c50d8ae3SPaolo Bonzini } 2331c50d8ae3SPaolo Bonzini 2332c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2333c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2334c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2335c50d8ae3SPaolo Bonzini int *nr_zapped) 2336c50d8ae3SPaolo Bonzini { 2337527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2338c50d8ae3SPaolo Bonzini 2339c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2340c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2341c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 23422de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 234361827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2344c50d8ae3SPaolo Bonzini 2345c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2346c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2347c50d8ae3SPaolo Bonzini 2348767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2349c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2350c50d8ae3SPaolo Bonzini 2351c50d8ae3SPaolo Bonzini if (sp->unsync) 2352c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2353c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2354c50d8ae3SPaolo Bonzini /* Count self */ 2355c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2356f95eec9bSSean Christopherson 2357f95eec9bSSean Christopherson /* 2358f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2359f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2360f95eec9bSSean Christopherson * !sp->root_count. 2361f95eec9bSSean Christopherson */ 2362f95eec9bSSean Christopherson if (sp->role.invalid) 2363f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2364f95eec9bSSean Christopherson else 2365c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 2366c50d8ae3SPaolo Bonzini kvm_mod_used_mmu_pages(kvm, -1); 2367c50d8ae3SPaolo Bonzini } else { 2368f95eec9bSSean Christopherson /* 2369f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2370f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2371f95eec9bSSean Christopherson */ 2372f95eec9bSSean Christopherson list_del(&sp->link); 2373c50d8ae3SPaolo Bonzini 2374c50d8ae3SPaolo Bonzini /* 2375c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2376c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2377c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2378c50d8ae3SPaolo Bonzini */ 2379527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2380c50d8ae3SPaolo Bonzini } 2381c50d8ae3SPaolo Bonzini 2382c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2383c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2384c50d8ae3SPaolo Bonzini 2385c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2386527d5cd7SSean Christopherson 2387527d5cd7SSean Christopherson /* 2388527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2389527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2390527d5cd7SSean Christopherson */ 2391527d5cd7SSean Christopherson if (zapped_root) 2392527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2393c50d8ae3SPaolo Bonzini return list_unstable; 2394c50d8ae3SPaolo Bonzini } 2395c50d8ae3SPaolo Bonzini 2396c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2397c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2398c50d8ae3SPaolo Bonzini { 2399c50d8ae3SPaolo Bonzini int nr_zapped; 2400c50d8ae3SPaolo Bonzini 2401c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2402c50d8ae3SPaolo Bonzini return nr_zapped; 2403c50d8ae3SPaolo Bonzini } 2404c50d8ae3SPaolo Bonzini 2405c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2406c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2407c50d8ae3SPaolo Bonzini { 2408c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2409c50d8ae3SPaolo Bonzini 2410c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2411c50d8ae3SPaolo Bonzini return; 2412c50d8ae3SPaolo Bonzini 2413c50d8ae3SPaolo Bonzini /* 2414c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2415c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2416c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2417c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2418c50d8ae3SPaolo Bonzini * 2419c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2420c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2421c50d8ae3SPaolo Bonzini */ 2422c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2423c50d8ae3SPaolo Bonzini 2424c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2425c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 242687654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2427c50d8ae3SPaolo Bonzini } 2428c50d8ae3SPaolo Bonzini } 2429c50d8ae3SPaolo Bonzini 24306b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 24316b82ef2cSSean Christopherson unsigned long nr_to_zap) 2432c50d8ae3SPaolo Bonzini { 24336b82ef2cSSean Christopherson unsigned long total_zapped = 0; 24346b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2435ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 24366b82ef2cSSean Christopherson bool unstable; 24376b82ef2cSSean Christopherson int nr_zapped; 2438c50d8ae3SPaolo Bonzini 2439c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2440ba7888ddSSean Christopherson return 0; 2441c50d8ae3SPaolo Bonzini 24426b82ef2cSSean Christopherson restart: 24438fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 24446b82ef2cSSean Christopherson /* 24456b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 24466b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 24476b82ef2cSSean Christopherson */ 24486b82ef2cSSean Christopherson if (sp->root_count) 24496b82ef2cSSean Christopherson continue; 24506b82ef2cSSean Christopherson 24516b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 24526b82ef2cSSean Christopherson &nr_zapped); 24536b82ef2cSSean Christopherson total_zapped += nr_zapped; 24546b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2455ba7888ddSSean Christopherson break; 2456ba7888ddSSean Christopherson 24576b82ef2cSSean Christopherson if (unstable) 24586b82ef2cSSean Christopherson goto restart; 2459ba7888ddSSean Christopherson } 24606b82ef2cSSean Christopherson 24616b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 24626b82ef2cSSean Christopherson 24636b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 24646b82ef2cSSean Christopherson return total_zapped; 24656b82ef2cSSean Christopherson } 24666b82ef2cSSean Christopherson 2467afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2468afe8d7e6SSean Christopherson { 2469afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2470afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2471afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2472afe8d7e6SSean Christopherson 2473afe8d7e6SSean Christopherson return 0; 2474c50d8ae3SPaolo Bonzini } 2475c50d8ae3SPaolo Bonzini 2476ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2477ba7888ddSSean Christopherson { 24786b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2479ba7888ddSSean Christopherson 24806b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2481ba7888ddSSean Christopherson return 0; 2482ba7888ddSSean Christopherson 24836b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2484ba7888ddSSean Christopherson 24856e6ec584SSean Christopherson /* 24866e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 24876e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 24886e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 24896e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2490c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 24916e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 24926e6ec584SSean Christopherson * page fault paths. 24936e6ec584SSean Christopherson */ 2494ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2495ba7888ddSSean Christopherson return -ENOSPC; 2496ba7888ddSSean Christopherson return 0; 2497ba7888ddSSean Christopherson } 2498ba7888ddSSean Christopherson 2499c50d8ae3SPaolo Bonzini /* 2500c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2501c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2502c50d8ae3SPaolo Bonzini */ 2503c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2504c50d8ae3SPaolo Bonzini { 2505531810caSBen Gardon write_lock(&kvm->mmu_lock); 2506c50d8ae3SPaolo Bonzini 2507c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 25086b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 25096b82ef2cSSean Christopherson goal_nr_mmu_pages); 2510c50d8ae3SPaolo Bonzini 2511c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2512c50d8ae3SPaolo Bonzini } 2513c50d8ae3SPaolo Bonzini 2514c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2515c50d8ae3SPaolo Bonzini 2516531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2517c50d8ae3SPaolo Bonzini } 2518c50d8ae3SPaolo Bonzini 2519c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2520c50d8ae3SPaolo Bonzini { 2521c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2522c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2523c50d8ae3SPaolo Bonzini int r; 2524c50d8ae3SPaolo Bonzini 2525c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2526c50d8ae3SPaolo Bonzini r = 0; 2527531810caSBen Gardon write_lock(&kvm->mmu_lock); 2528767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2529c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2530c50d8ae3SPaolo Bonzini sp->role.word); 2531c50d8ae3SPaolo Bonzini r = 1; 2532c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2533c50d8ae3SPaolo Bonzini } 2534c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2535531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2536c50d8ae3SPaolo Bonzini 2537c50d8ae3SPaolo Bonzini return r; 2538c50d8ae3SPaolo Bonzini } 253996ad91aeSSean Christopherson 254096ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 254196ad91aeSSean Christopherson { 254296ad91aeSSean Christopherson gpa_t gpa; 254396ad91aeSSean Christopherson int r; 254496ad91aeSSean Christopherson 2545347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 254696ad91aeSSean Christopherson return 0; 254796ad91aeSSean Christopherson 254896ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 254996ad91aeSSean Christopherson 255096ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 255196ad91aeSSean Christopherson 255296ad91aeSSean Christopherson return r; 255396ad91aeSSean Christopherson } 2554c50d8ae3SPaolo Bonzini 25554d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2556c50d8ae3SPaolo Bonzini { 2557c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 25584d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2559c50d8ae3SPaolo Bonzini sp->unsync = 1; 2560c50d8ae3SPaolo Bonzini 2561c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2562c50d8ae3SPaolo Bonzini } 2563c50d8ae3SPaolo Bonzini 25640337f585SSean Christopherson /* 25650337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 25660337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 25670337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 25680337f585SSean Christopherson * be write-protected. 25690337f585SSean Christopherson */ 25708283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 25712839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2572c50d8ae3SPaolo Bonzini { 2573c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2574ce25681dSSean Christopherson bool locked = false; 2575c50d8ae3SPaolo Bonzini 25760337f585SSean Christopherson /* 25770337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 25780337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 25790337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 25800337f585SSean Christopherson */ 25814d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 25820337f585SSean Christopherson return -EPERM; 2583c50d8ae3SPaolo Bonzini 25840337f585SSean Christopherson /* 25850337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 25860337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 25870337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 25880337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 25890337f585SSean Christopherson */ 2590767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2591c50d8ae3SPaolo Bonzini if (!can_unsync) 25920337f585SSean Christopherson return -EPERM; 2593c50d8ae3SPaolo Bonzini 2594c50d8ae3SPaolo Bonzini if (sp->unsync) 2595c50d8ae3SPaolo Bonzini continue; 2596c50d8ae3SPaolo Bonzini 25972839180cSPaolo Bonzini if (prefetch) 2598f1c4a88cSLai Jiangshan return -EEXIST; 2599f1c4a88cSLai Jiangshan 2600ce25681dSSean Christopherson /* 2601ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2602ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2603ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2604ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2605ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2606ce25681dSSean Christopherson */ 2607ce25681dSSean Christopherson if (!locked) { 2608ce25681dSSean Christopherson locked = true; 26094d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2610ce25681dSSean Christopherson 2611ce25681dSSean Christopherson /* 2612ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2613ce25681dSSean Christopherson * may have since marked the page unsync. A false 2614ce25681dSSean Christopherson * positive on the unprotected check above is not 2615ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2616ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2617ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2618ce25681dSSean Christopherson */ 2619ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2620ce25681dSSean Christopherson continue; 2621ce25681dSSean Christopherson } 2622ce25681dSSean Christopherson 26233bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 26244d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2625c50d8ae3SPaolo Bonzini } 2626ce25681dSSean Christopherson if (locked) 26274d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2628c50d8ae3SPaolo Bonzini 2629c50d8ae3SPaolo Bonzini /* 2630c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2631c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2632c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2633c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2634c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2635c50d8ae3SPaolo Bonzini * following could happen: 2636c50d8ae3SPaolo Bonzini * 2637c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2638c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2639c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2640c50d8ae3SPaolo Bonzini * to be writable 2641c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2642c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2643c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2644c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2645c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2646c50d8ae3SPaolo Bonzini * fault. 2647c50d8ae3SPaolo Bonzini * 2648c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2649c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2650c50d8ae3SPaolo Bonzini * 26510337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 26520337f585SSean Christopherson * false and skips the page. 2653c50d8ae3SPaolo Bonzini * 2654c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2655c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2656c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2657c50d8ae3SPaolo Bonzini * gets used. 2658c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2659c50d8ae3SPaolo Bonzini * as unsync 2660c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2661c50d8ae3SPaolo Bonzini * 2662c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2663264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2664264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2665c50d8ae3SPaolo Bonzini */ 2666c50d8ae3SPaolo Bonzini smp_wmb(); 2667c50d8ae3SPaolo Bonzini 26680337f585SSean Christopherson return 0; 2669c50d8ae3SPaolo Bonzini } 2670c50d8ae3SPaolo Bonzini 26718a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 26728a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2673a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2674799a4190SBen Gardon { 2675d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2676eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2677c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2678c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2679c50d8ae3SPaolo Bonzini bool flush = false; 2680ad67e480SPaolo Bonzini bool wrprot; 2681d786c778SPaolo Bonzini u64 spte; 2682c50d8ae3SPaolo Bonzini 2683a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2684a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 26852839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2686a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2687c50d8ae3SPaolo Bonzini 2688c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2689c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2690c50d8ae3SPaolo Bonzini 2691a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 26921075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2693a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2694a54aa15cSSean Christopherson return RET_PF_EMULATE; 2695a54aa15cSSean Christopherson } 2696a54aa15cSSean Christopherson 2697c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2698c50d8ae3SPaolo Bonzini /* 2699c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2700c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2701c50d8ae3SPaolo Bonzini */ 27023bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2703c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2704c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2705c50d8ae3SPaolo Bonzini 27062ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2707c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2708c50d8ae3SPaolo Bonzini flush = true; 2709c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2710c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2711c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2712c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2713c50d8ae3SPaolo Bonzini flush = true; 2714c50d8ae3SPaolo Bonzini } else 2715c50d8ae3SPaolo Bonzini was_rmapped = 1; 2716c50d8ae3SPaolo Bonzini } 2717c50d8ae3SPaolo Bonzini 27182839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 27197158bee4SPaolo Bonzini true, host_writable, &spte); 2720d786c778SPaolo Bonzini 2721d786c778SPaolo Bonzini if (*sptep == spte) { 2722d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2723d786c778SPaolo Bonzini } else { 2724d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 27255959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2726c50d8ae3SPaolo Bonzini } 2727c50d8ae3SPaolo Bonzini 2728ad67e480SPaolo Bonzini if (wrprot) { 2729c50d8ae3SPaolo Bonzini if (write_fault) 2730c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2731c50d8ae3SPaolo Bonzini } 2732c50d8ae3SPaolo Bonzini 2733d786c778SPaolo Bonzini if (flush) 2734c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2735c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2736c50d8ae3SPaolo Bonzini 2737c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2738c50d8ae3SPaolo Bonzini 2739c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2740d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 274171f51d2cSMingwei Zhang kvm_update_page_stats(vcpu->kvm, level, 1); 27428a9f566aSDavid Matlack rmap_add(vcpu, slot, sptep, gfn); 2743c50d8ae3SPaolo Bonzini } 2744c50d8ae3SPaolo Bonzini 2745c50d8ae3SPaolo Bonzini return ret; 2746c50d8ae3SPaolo Bonzini } 2747c50d8ae3SPaolo Bonzini 2748c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2749c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2750c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2751c50d8ae3SPaolo Bonzini { 2752c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2753c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 27540a2b64c5SBen Gardon unsigned int access = sp->role.access; 2755c50d8ae3SPaolo Bonzini int i, ret; 2756c50d8ae3SPaolo Bonzini gfn_t gfn; 2757c50d8ae3SPaolo Bonzini 2758c50d8ae3SPaolo Bonzini gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt); 2759c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2760c50d8ae3SPaolo Bonzini if (!slot) 2761c50d8ae3SPaolo Bonzini return -1; 2762c50d8ae3SPaolo Bonzini 2763c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2764c50d8ae3SPaolo Bonzini if (ret <= 0) 2765c50d8ae3SPaolo Bonzini return -1; 2766c50d8ae3SPaolo Bonzini 2767c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 27688a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2769a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2770c50d8ae3SPaolo Bonzini put_page(pages[i]); 2771c50d8ae3SPaolo Bonzini } 2772c50d8ae3SPaolo Bonzini 2773c50d8ae3SPaolo Bonzini return 0; 2774c50d8ae3SPaolo Bonzini } 2775c50d8ae3SPaolo Bonzini 2776c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2777c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2778c50d8ae3SPaolo Bonzini { 2779c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2780c50d8ae3SPaolo Bonzini int i; 2781c50d8ae3SPaolo Bonzini 2782c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2783c50d8ae3SPaolo Bonzini 2784c50d8ae3SPaolo Bonzini i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); 2785c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2786c50d8ae3SPaolo Bonzini 2787c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2788c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2789c50d8ae3SPaolo Bonzini if (!start) 2790c50d8ae3SPaolo Bonzini continue; 2791c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2792c6cecc4bSSean Christopherson return; 2793c50d8ae3SPaolo Bonzini start = NULL; 2794c50d8ae3SPaolo Bonzini } else if (!start) 2795c50d8ae3SPaolo Bonzini start = spte; 2796c50d8ae3SPaolo Bonzini } 2797c6cecc4bSSean Christopherson if (start) 2798c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2799c50d8ae3SPaolo Bonzini } 2800c50d8ae3SPaolo Bonzini 2801c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2802c50d8ae3SPaolo Bonzini { 2803c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2804c50d8ae3SPaolo Bonzini 280557354682SSean Christopherson sp = sptep_to_sp(sptep); 2806c50d8ae3SPaolo Bonzini 2807c50d8ae3SPaolo Bonzini /* 2808c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2809c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2810c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2811c50d8ae3SPaolo Bonzini */ 2812c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2813c50d8ae3SPaolo Bonzini return; 2814c50d8ae3SPaolo Bonzini 28153bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2816c50d8ae3SPaolo Bonzini return; 2817c50d8ae3SPaolo Bonzini 28184a42d848SDavid Stevens /* 28194a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 28204a42d848SDavid Stevens * accidentally prefetching those addresses. 28214a42d848SDavid Stevens */ 28224a42d848SDavid Stevens if (unlikely(vcpu->kvm->mmu_notifier_count)) 28234a42d848SDavid Stevens return; 28244a42d848SDavid Stevens 2825c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2826c50d8ae3SPaolo Bonzini } 2827c50d8ae3SPaolo Bonzini 28281b6d9d9eSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, 28298ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2830db543216SSean Christopherson { 2831284dc493SSean Christopherson int level = PG_LEVEL_4K; 28325d49f08cSSean Christopherson struct page *page; 2833db543216SSean Christopherson unsigned long hva; 283444187235SMingwei Zhang unsigned long flags; 283544187235SMingwei Zhang pgd_t pgd; 283644187235SMingwei Zhang p4d_t p4d; 283744187235SMingwei Zhang pud_t pud; 283844187235SMingwei Zhang pmd_t pmd; 2839db543216SSean Christopherson 28405d49f08cSSean Christopherson /* 28415d49f08cSSean Christopherson * Note, @slot must be non-NULL, i.e. the caller is responsible for 28425d49f08cSSean Christopherson * ensuring @pfn isn't garbage and is backed by a memslot. 28435d49f08cSSean Christopherson */ 28445d49f08cSSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 28455d49f08cSSean Christopherson if (!page) 28465d49f08cSSean Christopherson return PG_LEVEL_4K; 28475d49f08cSSean Christopherson 2848284dc493SSean Christopherson if (!PageCompound(page) && !kvm_is_zone_device_page(page)) 28493bae0459SSean Christopherson return PG_LEVEL_4K; 2850db543216SSean Christopherson 2851293e306eSSean Christopherson /* 2852293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2853293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2854293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2855293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2856293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2857293e306eSSean Christopherson * read-only memslot. 2858293e306eSSean Christopherson */ 2859db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2860db543216SSean Christopherson 286144187235SMingwei Zhang /* 286244187235SMingwei Zhang * Lookup the mapping level in the current mm. The information 286344187235SMingwei Zhang * may become stale soon, but it is safe to use as long as 286444187235SMingwei Zhang * 1) mmu_notifier_retry was checked after taking mmu_lock, and 286544187235SMingwei Zhang * 2) mmu_lock is taken now. 286644187235SMingwei Zhang * 286744187235SMingwei Zhang * We still need to disable IRQs to prevent concurrent tear down 286844187235SMingwei Zhang * of page tables. 286944187235SMingwei Zhang */ 287044187235SMingwei Zhang local_irq_save(flags); 2871db543216SSean Christopherson 287244187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 287344187235SMingwei Zhang if (pgd_none(pgd)) 287444187235SMingwei Zhang goto out; 287544187235SMingwei Zhang 287644187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 287744187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 287844187235SMingwei Zhang goto out; 287944187235SMingwei Zhang 288044187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 288144187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 288244187235SMingwei Zhang goto out; 288344187235SMingwei Zhang 288444187235SMingwei Zhang if (pud_large(pud)) { 288544187235SMingwei Zhang level = PG_LEVEL_1G; 288644187235SMingwei Zhang goto out; 288744187235SMingwei Zhang } 288844187235SMingwei Zhang 288944187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 289044187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 289144187235SMingwei Zhang goto out; 289244187235SMingwei Zhang 289344187235SMingwei Zhang if (pmd_large(pmd)) 289444187235SMingwei Zhang level = PG_LEVEL_2M; 289544187235SMingwei Zhang 289644187235SMingwei Zhang out: 289744187235SMingwei Zhang local_irq_restore(flags); 2898db543216SSean Christopherson return level; 2899db543216SSean Christopherson } 2900db543216SSean Christopherson 29018ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 29028ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 29038ca6f063SBen Gardon kvm_pfn_t pfn, int max_level) 29041b6d9d9eSSean Christopherson { 29051b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 2906ec607a56SPaolo Bonzini int host_level; 29071b6d9d9eSSean Christopherson 29081b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 29091b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 29101b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 29111b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 29121b6d9d9eSSean Christopherson break; 29131b6d9d9eSSean Christopherson } 29141b6d9d9eSSean Christopherson 29151b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 29161b6d9d9eSSean Christopherson return PG_LEVEL_4K; 29171b6d9d9eSSean Christopherson 2918ec607a56SPaolo Bonzini host_level = host_pfn_mapping_level(kvm, gfn, pfn, slot); 2919ec607a56SPaolo Bonzini return min(host_level, max_level); 29201b6d9d9eSSean Christopherson } 29211b6d9d9eSSean Christopherson 292273a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 29230885904dSSean Christopherson { 2924e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 292517eff019SSean Christopherson kvm_pfn_t mask; 29260885904dSSean Christopherson 292773a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 29283cf06612SSean Christopherson 292973a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 293073a3c659SPaolo Bonzini return; 293117eff019SSean Christopherson 29325d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 293373a3c659SPaolo Bonzini return; 293417eff019SSean Christopherson 2935e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 293673a3c659SPaolo Bonzini return; 2937293e306eSSean Christopherson 29383cf06612SSean Christopherson /* 29393cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 29403cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 29413cf06612SSean Christopherson */ 294273a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 294373a3c659SPaolo Bonzini fault->gfn, fault->pfn, 294473a3c659SPaolo Bonzini fault->max_level); 294573a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 294673a3c659SPaolo Bonzini return; 29474cd071d1SSean Christopherson 29480885904dSSean Christopherson /* 29494cd071d1SSean Christopherson * mmu_notifier_retry() was successful and mmu_lock is held, so 29504cd071d1SSean Christopherson * the pmd can't be split from under us. 29510885904dSSean Christopherson */ 295273a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 295373a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 295473a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 295573a3c659SPaolo Bonzini fault->pfn &= ~mask; 29560885904dSSean Christopherson } 29570885904dSSean Christopherson 2958536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 2959c50d8ae3SPaolo Bonzini { 2960536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 2961536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 2962c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 2963c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 2964c50d8ae3SPaolo Bonzini /* 2965c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 2966c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 2967c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 2968c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 2969c50d8ae3SPaolo Bonzini * the address. 2970c50d8ae3SPaolo Bonzini */ 2971536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 2972536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 2973536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 2974536f0e6aSPaolo Bonzini fault->goal_level--; 2975c50d8ae3SPaolo Bonzini } 2976c50d8ae3SPaolo Bonzini } 2977c50d8ae3SPaolo Bonzini 297843b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 2979c50d8ae3SPaolo Bonzini { 2980c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 2981c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 298273a3c659SPaolo Bonzini int ret; 298343b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 2984c50d8ae3SPaolo Bonzini 298573a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 29864cd071d1SSean Christopherson 2987f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 298843b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 2989c50d8ae3SPaolo Bonzini /* 2990c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 2991c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 2992c50d8ae3SPaolo Bonzini */ 299373a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 2994536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 2995c50d8ae3SPaolo Bonzini 299643b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 299773a3c659SPaolo Bonzini if (it.level == fault->goal_level) 2998c50d8ae3SPaolo Bonzini break; 2999c50d8ae3SPaolo Bonzini 3000c50d8ae3SPaolo Bonzini drop_large_spte(vcpu, it.sptep); 300103fffc54SSean Christopherson if (is_shadow_present_pte(*it.sptep)) 300203fffc54SSean Christopherson continue; 300303fffc54SSean Christopherson 30042e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 3005c50d8ae3SPaolo Bonzini 3006c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 300773a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 300873a3c659SPaolo Bonzini fault->req_level >= it.level) 3009c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 3010c50d8ae3SPaolo Bonzini } 3011c50d8ae3SPaolo Bonzini 3012b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3013b1a429fbSSean Christopherson return -EFAULT; 3014b1a429fbSSean Christopherson 30158a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3016a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 301712703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 301812703759SSean Christopherson return ret; 301912703759SSean Christopherson 3020c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3021c50d8ae3SPaolo Bonzini return ret; 3022c50d8ae3SPaolo Bonzini } 3023c50d8ae3SPaolo Bonzini 3024c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 3025c50d8ae3SPaolo Bonzini { 3026c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 3027c50d8ae3SPaolo Bonzini } 3028c50d8ae3SPaolo Bonzini 3029c50d8ae3SPaolo Bonzini static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 3030c50d8ae3SPaolo Bonzini { 3031c50d8ae3SPaolo Bonzini /* 3032c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3033c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3034c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3035c50d8ae3SPaolo Bonzini */ 3036c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3037c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3038c50d8ae3SPaolo Bonzini 3039c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3040c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3041c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3042c50d8ae3SPaolo Bonzini } 3043c50d8ae3SPaolo Bonzini 3044c50d8ae3SPaolo Bonzini return -EFAULT; 3045c50d8ae3SPaolo Bonzini } 3046c50d8ae3SPaolo Bonzini 30475276c616SSean Christopherson static int handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 30485276c616SSean Christopherson unsigned int access) 3049c50d8ae3SPaolo Bonzini { 3050c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 30515276c616SSean Christopherson if (unlikely(is_error_pfn(fault->pfn))) 30525276c616SSean Christopherson return kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); 3053c50d8ae3SPaolo Bonzini 3054e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 30553a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 30563a13f4feSPaolo Bonzini 30573a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3058c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 305930ab5901SSean Christopherson /* 306030ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 306130ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 306286931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 306386931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 306486931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 306586931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 306686931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 306786931ff7SSean Christopherson * the hardware's). 306830ab5901SSean Christopherson */ 30698b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 30705276c616SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) 30715276c616SSean Christopherson return RET_PF_EMULATE; 307230ab5901SSean Christopherson } 3073c50d8ae3SPaolo Bonzini 30745276c616SSean Christopherson return RET_PF_CONTINUE; 3075c50d8ae3SPaolo Bonzini } 3076c50d8ae3SPaolo Bonzini 30773c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3078c50d8ae3SPaolo Bonzini { 3079c50d8ae3SPaolo Bonzini /* 30805c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 30815c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 30825c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 30835c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3084c50d8ae3SPaolo Bonzini */ 30853c8ad5a6SPaolo Bonzini if (fault->rsvd) 3086c50d8ae3SPaolo Bonzini return false; 3087c50d8ae3SPaolo Bonzini 3088c50d8ae3SPaolo Bonzini /* 3089c50d8ae3SPaolo Bonzini * #PF can be fast if: 3090c50d8ae3SPaolo Bonzini * 309154275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 309254275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 309354275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 309454275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 309554275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 309654275f74SSean Christopherson * mechanism only supports direct MMUs. 309754275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 309854275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 309954275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 310054275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 310154275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3102c50d8ae3SPaolo Bonzini */ 31035c64aba5SSean Christopherson if (!fault->present) 31045c64aba5SSean Christopherson return !kvm_ad_enabled(); 31055c64aba5SSean Christopherson 31065c64aba5SSean Christopherson /* 31075c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 31085c64aba5SSean Christopherson * the "exec" flag. 31095c64aba5SSean Christopherson */ 31105c64aba5SSean Christopherson return fault->write; 3111c50d8ae3SPaolo Bonzini } 3112c50d8ae3SPaolo Bonzini 3113c50d8ae3SPaolo Bonzini /* 3114c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3115c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3116c50d8ae3SPaolo Bonzini */ 3117c50d8ae3SPaolo Bonzini static bool 3118e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3119c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3120c50d8ae3SPaolo Bonzini { 3121c50d8ae3SPaolo Bonzini /* 3122c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3123c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3124c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3125c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3126c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3127c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3128c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3129c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3130c50d8ae3SPaolo Bonzini * 3131c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3132c50d8ae3SPaolo Bonzini */ 31332db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3134c50d8ae3SPaolo Bonzini return false; 3135c50d8ae3SPaolo Bonzini 3136e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3137e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3138c50d8ae3SPaolo Bonzini 3139c50d8ae3SPaolo Bonzini return true; 3140c50d8ae3SPaolo Bonzini } 3141c50d8ae3SPaolo Bonzini 31423c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3143c50d8ae3SPaolo Bonzini { 31443c8ad5a6SPaolo Bonzini if (fault->exec) 3145c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3146c50d8ae3SPaolo Bonzini 31473c8ad5a6SPaolo Bonzini if (fault->write) 3148c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3149c50d8ae3SPaolo Bonzini 3150c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3151c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3152c50d8ae3SPaolo Bonzini } 3153c50d8ae3SPaolo Bonzini 3154c50d8ae3SPaolo Bonzini /* 31556e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 31566e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 31576e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 31586e8eb206SDavid Matlack * 31596e8eb206SDavid Matlack * Contract: 31606e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 31616e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 31626e8eb206SDavid Matlack */ 31636e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 31646e8eb206SDavid Matlack { 31656e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 31666e8eb206SDavid Matlack u64 old_spte; 31676e8eb206SDavid Matlack u64 *sptep = NULL; 31686e8eb206SDavid Matlack 31696e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 31706e8eb206SDavid Matlack sptep = iterator.sptep; 31716e8eb206SDavid Matlack *spte = old_spte; 31726e8eb206SDavid Matlack } 31736e8eb206SDavid Matlack 31746e8eb206SDavid Matlack return sptep; 31756e8eb206SDavid Matlack } 31766e8eb206SDavid Matlack 31776e8eb206SDavid Matlack /* 3178c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3179c50d8ae3SPaolo Bonzini */ 31803c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3181c50d8ae3SPaolo Bonzini { 3182c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3183c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3184c50d8ae3SPaolo Bonzini u64 spte = 0ull; 31856e8eb206SDavid Matlack u64 *sptep = NULL; 3186c50d8ae3SPaolo Bonzini uint retry_count = 0; 3187c50d8ae3SPaolo Bonzini 31883c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3189c4371c2aSSean Christopherson return ret; 3190c50d8ae3SPaolo Bonzini 3191c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3192c50d8ae3SPaolo Bonzini 3193c50d8ae3SPaolo Bonzini do { 3194c50d8ae3SPaolo Bonzini u64 new_spte; 3195c50d8ae3SPaolo Bonzini 31966e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 31973c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 31986e8eb206SDavid Matlack else 31993c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3200c50d8ae3SPaolo Bonzini 3201ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3202ec89e643SSean Christopherson break; 3203ec89e643SSean Christopherson 32046e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3205c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3206c50d8ae3SPaolo Bonzini break; 3207c50d8ae3SPaolo Bonzini 3208c50d8ae3SPaolo Bonzini /* 3209c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3210c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3211c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3212c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3213c50d8ae3SPaolo Bonzini * current CPU took the fault. 3214c50d8ae3SPaolo Bonzini * 3215c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3216c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3217c50d8ae3SPaolo Bonzini */ 32183c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3219c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3220c50d8ae3SPaolo Bonzini break; 3221c50d8ae3SPaolo Bonzini } 3222c50d8ae3SPaolo Bonzini 3223c50d8ae3SPaolo Bonzini new_spte = spte; 3224c50d8ae3SPaolo Bonzini 322554275f74SSean Christopherson /* 322654275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 322754275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 322854275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 322954275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 323054275f74SSean Christopherson */ 323154275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3232c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3233c50d8ae3SPaolo Bonzini 3234c50d8ae3SPaolo Bonzini /* 323554275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 323654275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 323754275f74SSean Christopherson * that were write-protected for dirty-logging or access 323854275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 323954275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 324054275f74SSean Christopherson * The is_access_allowed() check above handles the common case 324154275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 324254275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 324354275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3244c50d8ae3SPaolo Bonzini */ 3245706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3246c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3247c50d8ae3SPaolo Bonzini 3248c50d8ae3SPaolo Bonzini /* 324910c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 325010c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 325110c30de0SJunaid Shahid * first page into the dirty-bitmap in 3252c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3253c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3254c50d8ae3SPaolo Bonzini * 3255c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3256c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3257c50d8ae3SPaolo Bonzini */ 325810c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 325910c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3260c50d8ae3SPaolo Bonzini break; 3261c50d8ae3SPaolo Bonzini } 3262c50d8ae3SPaolo Bonzini 3263c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3264c50d8ae3SPaolo Bonzini if (new_spte == spte || 32653c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3266c50d8ae3SPaolo Bonzini break; 3267c50d8ae3SPaolo Bonzini 3268c50d8ae3SPaolo Bonzini /* 3269c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3270c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 32713ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3272c50d8ae3SPaolo Bonzini */ 3273e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3274c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3275c50d8ae3SPaolo Bonzini break; 3276c4371c2aSSean Christopherson } 3277c50d8ae3SPaolo Bonzini 3278c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3279c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3280c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3281c50d8ae3SPaolo Bonzini break; 3282c50d8ae3SPaolo Bonzini } 3283c50d8ae3SPaolo Bonzini 3284c50d8ae3SPaolo Bonzini } while (true); 3285c50d8ae3SPaolo Bonzini 3286f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3287c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3288c50d8ae3SPaolo Bonzini 32891075d41eSSean Christopherson if (ret != RET_PF_INVALID) 32901075d41eSSean Christopherson vcpu->stat.pf_fast++; 32911075d41eSSean Christopherson 3292c4371c2aSSean Christopherson return ret; 3293c50d8ae3SPaolo Bonzini } 3294c50d8ae3SPaolo Bonzini 3295c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3296c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3297c50d8ae3SPaolo Bonzini { 3298c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3299c50d8ae3SPaolo Bonzini 3300c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3301c50d8ae3SPaolo Bonzini return; 3302c50d8ae3SPaolo Bonzini 33032ca3129eSSean Christopherson sp = to_shadow_page(*root_hpa & SPTE_BASE_ADDR_MASK); 33049191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 33059191b8f0SPaolo Bonzini return; 330602c00b3aSBen Gardon 3307897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 33086103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 330976eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3310c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3311c50d8ae3SPaolo Bonzini 3312c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3313c50d8ae3SPaolo Bonzini } 3314c50d8ae3SPaolo Bonzini 3315c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 33160c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3317c50d8ae3SPaolo Bonzini ulong roots_to_free) 3318c50d8ae3SPaolo Bonzini { 3319c50d8ae3SPaolo Bonzini int i; 3320c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3321594bef79SPaolo Bonzini bool free_active_root; 3322c50d8ae3SPaolo Bonzini 3323c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3324c50d8ae3SPaolo Bonzini 3325c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3326594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3327594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3328594bef79SPaolo Bonzini 3329594bef79SPaolo Bonzini if (!free_active_root) { 3330c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3331c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3332c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3333c50d8ae3SPaolo Bonzini break; 3334c50d8ae3SPaolo Bonzini 3335c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3336c50d8ae3SPaolo Bonzini return; 3337c50d8ae3SPaolo Bonzini } 3338c50d8ae3SPaolo Bonzini 3339531810caSBen Gardon write_lock(&kvm->mmu_lock); 3340c50d8ae3SPaolo Bonzini 3341c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3342c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 33434d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3344c50d8ae3SPaolo Bonzini &invalid_list); 3345c50d8ae3SPaolo Bonzini 3346c50d8ae3SPaolo Bonzini if (free_active_root) { 3347594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3348b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 334904d45551SSean Christopherson } else if (mmu->pae_root) { 3350c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3351c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3352c834e5e4SSean Christopherson continue; 3353c834e5e4SSean Christopherson 3354c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3355c50d8ae3SPaolo Bonzini &invalid_list); 3356c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3357c50d8ae3SPaolo Bonzini } 3358c50d8ae3SPaolo Bonzini } 3359b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3360b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3361c50d8ae3SPaolo Bonzini } 3362c50d8ae3SPaolo Bonzini 33634d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3364531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3365c50d8ae3SPaolo Bonzini } 3366c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3367c50d8ae3SPaolo Bonzini 33680c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 336925b62c62SSean Christopherson { 337025b62c62SSean Christopherson unsigned long roots_to_free = 0; 337125b62c62SSean Christopherson hpa_t root_hpa; 337225b62c62SSean Christopherson int i; 337325b62c62SSean Christopherson 337425b62c62SSean Christopherson /* 337525b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 337625b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 337725b62c62SSean Christopherson */ 33787a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 337925b62c62SSean Christopherson 338025b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 338125b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 338225b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 338325b62c62SSean Christopherson continue; 338425b62c62SSean Christopherson 338525b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 338625b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 338725b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 338825b62c62SSean Christopherson } 338925b62c62SSean Christopherson 33900c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 339125b62c62SSean Christopherson } 339225b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 339325b62c62SSean Christopherson 339425b62c62SSean Christopherson 3395c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3396c50d8ae3SPaolo Bonzini { 3397c50d8ae3SPaolo Bonzini int ret = 0; 3398c50d8ae3SPaolo Bonzini 3399995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3400c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3401c50d8ae3SPaolo Bonzini ret = 1; 3402c50d8ae3SPaolo Bonzini } 3403c50d8ae3SPaolo Bonzini 3404c50d8ae3SPaolo Bonzini return ret; 3405c50d8ae3SPaolo Bonzini } 3406c50d8ae3SPaolo Bonzini 34072e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 340886938ab6SDavid Matlack u8 level) 3409c50d8ae3SPaolo Bonzini { 34102e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3411c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 34128123f265SSean Christopherson 34132e65e842SDavid Matlack role.level = level; 34142e65e842SDavid Matlack role.quadrant = quadrant; 34152e65e842SDavid Matlack 34167f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 34177f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 34187f497775SDavid Matlack 341987654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 34208123f265SSean Christopherson ++sp->root_count; 34218123f265SSean Christopherson 34228123f265SSean Christopherson return __pa(sp->spt); 34238123f265SSean Christopherson } 34248123f265SSean Christopherson 34258123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 34268123f265SSean Christopherson { 3427b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3428a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 34298123f265SSean Christopherson hpa_t root; 3430c50d8ae3SPaolo Bonzini unsigned i; 34314a38162eSPaolo Bonzini int r; 34324a38162eSPaolo Bonzini 34334a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 34344a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 34354a38162eSPaolo Bonzini if (r < 0) 34364a38162eSPaolo Bonzini goto out_unlock; 3437c50d8ae3SPaolo Bonzini 3438897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 343902c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3440b9e5603cSPaolo Bonzini mmu->root.hpa = root; 344102c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 344286938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3443b9e5603cSPaolo Bonzini mmu->root.hpa = root; 34448123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 34454a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 34464a38162eSPaolo Bonzini r = -EIO; 34474a38162eSPaolo Bonzini goto out_unlock; 34484a38162eSPaolo Bonzini } 344973ad1606SSean Christopherson 3450c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3451c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3452c50d8ae3SPaolo Bonzini 34537f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 34542e65e842SDavid Matlack PT32_ROOT_LEVEL); 345517e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3456d2263de1SYuan Yao shadow_me_value; 3457c50d8ae3SPaolo Bonzini } 3458b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 345973ad1606SSean Christopherson } else { 346073ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 34614a38162eSPaolo Bonzini r = -EIO; 34624a38162eSPaolo Bonzini goto out_unlock; 346373ad1606SSean Christopherson } 34643651c7fcSSean Christopherson 3465b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3466b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 34674a38162eSPaolo Bonzini out_unlock: 34684a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 34694a38162eSPaolo Bonzini return r; 3470c50d8ae3SPaolo Bonzini } 3471c50d8ae3SPaolo Bonzini 34721e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 34731e76a3ceSDavid Stevens { 34741e76a3ceSDavid Stevens struct kvm_memslots *slots; 34751e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3476a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 34771e76a3ceSDavid Stevens 34781e76a3ceSDavid Stevens /* 34791e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 34801e76a3ceSDavid Stevens * taking the lock. 34811e76a3ceSDavid Stevens */ 34821e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34831e76a3ceSDavid Stevens return 0; 34841e76a3ceSDavid Stevens 34851e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 34861e76a3ceSDavid Stevens 34871e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 34881e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 34891e76a3ceSDavid Stevens goto out_unlock; 34901e76a3ceSDavid Stevens 34911e76a3ceSDavid Stevens /* 34921e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 34931e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 34941e76a3ceSDavid Stevens */ 34951e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 34961e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 34971e76a3ceSDavid Stevens goto out_success; 34981e76a3ceSDavid Stevens 34991e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 35001e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3501a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 35021e76a3ceSDavid Stevens /* 35031e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 35041e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 35051e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 35061e76a3ceSDavid Stevens * failure to avoid having to track which allocations 35071e76a3ceSDavid Stevens * were made now versus when the memslot was created. 35081e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 35091e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 35101e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 35111e76a3ceSDavid Stevens */ 35121e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 35131e76a3ceSDavid Stevens if (r) 35141e76a3ceSDavid Stevens goto out_unlock; 35151e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 35161e76a3ceSDavid Stevens if (r) 35171e76a3ceSDavid Stevens goto out_unlock; 35181e76a3ceSDavid Stevens } 35191e76a3ceSDavid Stevens } 35201e76a3ceSDavid Stevens 35211e76a3ceSDavid Stevens /* 35221e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 35231e76a3ceSDavid Stevens * all the related pointers are set. 35241e76a3ceSDavid Stevens */ 35251e76a3ceSDavid Stevens out_success: 35261e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 35271e76a3ceSDavid Stevens 35281e76a3ceSDavid Stevens out_unlock: 35291e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 35301e76a3ceSDavid Stevens return r; 35311e76a3ceSDavid Stevens } 35321e76a3ceSDavid Stevens 3533c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3534c50d8ae3SPaolo Bonzini { 3535b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 35366e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3537be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 35387f497775SDavid Matlack int quadrant, i, r; 35398123f265SSean Christopherson hpa_t root; 3540c50d8ae3SPaolo Bonzini 3541b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3542be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3543c50d8ae3SPaolo Bonzini 3544c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3545c50d8ae3SPaolo Bonzini return 1; 3546c50d8ae3SPaolo Bonzini 3547c50d8ae3SPaolo Bonzini /* 35484a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 35494a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 35504a38162eSPaolo Bonzini */ 35514d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 35526e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 35536e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 35546e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 35556e0918aeSSean Christopherson continue; 35566e0918aeSSean Christopherson 35576e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 35586e0918aeSSean Christopherson return 1; 35596e0918aeSSean Christopherson } 35606e0918aeSSean Christopherson } 35616e0918aeSSean Christopherson 35621e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3563d501f747SBen Gardon if (r) 3564d501f747SBen Gardon return r; 3565d501f747SBen Gardon 35664a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35674a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35684a38162eSPaolo Bonzini if (r < 0) 35694a38162eSPaolo Bonzini goto out_unlock; 35704a38162eSPaolo Bonzini 3571c50d8ae3SPaolo Bonzini /* 3572c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3573c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3574c50d8ae3SPaolo Bonzini */ 35754d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 35768123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 357786938ab6SDavid Matlack mmu->root_role.level); 3578b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3579be01e8e2SSean Christopherson goto set_root_pgd; 3580c50d8ae3SPaolo Bonzini } 3581c50d8ae3SPaolo Bonzini 35824a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35834a38162eSPaolo Bonzini r = -EIO; 35844a38162eSPaolo Bonzini goto out_unlock; 35854a38162eSPaolo Bonzini } 358673ad1606SSean Christopherson 3587c50d8ae3SPaolo Bonzini /* 3588c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3589c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3590c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3591c50d8ae3SPaolo Bonzini */ 3592e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3593a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3594c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3595c50d8ae3SPaolo Bonzini 359603ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 35974a38162eSPaolo Bonzini r = -EIO; 35984a38162eSPaolo Bonzini goto out_unlock; 35994a38162eSPaolo Bonzini } 360003ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3601cb0f722aSWei Huang 3602a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3603cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3604cb0f722aSWei Huang r = -EIO; 3605cb0f722aSWei Huang goto out_unlock; 3606cb0f722aSWei Huang } 3607cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3608cb0f722aSWei Huang } 360904d45551SSean Christopherson } 361004d45551SSean Christopherson 3611c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3612c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 36136e6ec584SSean Christopherson 36144d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 36156e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3616c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3617c50d8ae3SPaolo Bonzini continue; 3618c50d8ae3SPaolo Bonzini } 36196e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3620c50d8ae3SPaolo Bonzini } 3621c50d8ae3SPaolo Bonzini 36227f497775SDavid Matlack /* 36237f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 36247f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 36257f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 36267f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 36277f497775SDavid Matlack */ 36287f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 36297f497775SDavid Matlack 36307f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3631b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3632c50d8ae3SPaolo Bonzini } 3633c50d8ae3SPaolo Bonzini 3634a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3635b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3636a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3637b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3638ba0a194fSSean Christopherson else 3639b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3640c50d8ae3SPaolo Bonzini 3641be01e8e2SSean Christopherson set_root_pgd: 3642b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 36434a38162eSPaolo Bonzini out_unlock: 36444a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3645c50d8ae3SPaolo Bonzini 3646c6c937d6SLike Xu return r; 3647c50d8ae3SPaolo Bonzini } 3648c50d8ae3SPaolo Bonzini 3649748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3650c50d8ae3SPaolo Bonzini { 3651748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3652a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3653cb0f722aSWei Huang u64 *pml5_root = NULL; 3654cb0f722aSWei Huang u64 *pml4_root = NULL; 3655cb0f722aSWei Huang u64 *pae_root; 3656748e52b9SSean Christopherson 3657748e52b9SSean Christopherson /* 3658748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3659748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3660748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3661748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3662748e52b9SSean Christopherson */ 3663347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3664347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3665a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3666748e52b9SSean Christopherson return 0; 3667748e52b9SSean Christopherson 3668a717a780SSean Christopherson /* 3669a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3670a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3671a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3672a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3673a717a780SSean Christopherson * prior MMU would also have required pml5. 3674a717a780SSean Christopherson */ 3675a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3676748e52b9SSean Christopherson return 0; 3677748e52b9SSean Christopherson 3678748e52b9SSean Christopherson /* 3679748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3680748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3681748e52b9SSean Christopherson */ 3682cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3683a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3684748e52b9SSean Christopherson return -EIO; 3685748e52b9SSean Christopherson 36864a98623dSSean Christopherson /* 36874a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 36884a98623dSSean Christopherson * doesn't need to be decrypted. 36894a98623dSSean Christopherson */ 3690748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3691748e52b9SSean Christopherson if (!pae_root) 3692748e52b9SSean Christopherson return -ENOMEM; 3693748e52b9SSean Christopherson 3694cb0f722aSWei Huang #ifdef CONFIG_X86_64 369503ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3696cb0f722aSWei Huang if (!pml4_root) 3697cb0f722aSWei Huang goto err_pml4; 3698cb0f722aSWei Huang 3699a717a780SSean Christopherson if (need_pml5) { 3700cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3701cb0f722aSWei Huang if (!pml5_root) 3702cb0f722aSWei Huang goto err_pml5; 3703748e52b9SSean Christopherson } 3704cb0f722aSWei Huang #endif 3705748e52b9SSean Christopherson 3706748e52b9SSean Christopherson mmu->pae_root = pae_root; 370703ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3708cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3709748e52b9SSean Christopherson 3710748e52b9SSean Christopherson return 0; 3711cb0f722aSWei Huang 3712cb0f722aSWei Huang #ifdef CONFIG_X86_64 3713cb0f722aSWei Huang err_pml5: 3714cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3715cb0f722aSWei Huang err_pml4: 3716cb0f722aSWei Huang free_page((unsigned long)pae_root); 3717cb0f722aSWei Huang return -ENOMEM; 3718cb0f722aSWei Huang #endif 3719c50d8ae3SPaolo Bonzini } 3720c50d8ae3SPaolo Bonzini 3721264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3722264d3dc1SLai Jiangshan { 3723264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3724264d3dc1SLai Jiangshan 372561b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 372661b05a9fSLai Jiangshan return false; 372761b05a9fSLai Jiangshan 3728264d3dc1SLai Jiangshan /* 3729264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3730264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3731264d3dc1SLai Jiangshan * 3732264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3733264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3734264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3735264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3736264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3737264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3738264d3dc1SLai Jiangshan * requirement isn't satisfied. 3739264d3dc1SLai Jiangshan */ 3740264d3dc1SLai Jiangshan smp_rmb(); 3741264d3dc1SLai Jiangshan sp = to_shadow_page(root); 37425d6a3221SSean Christopherson 37435d6a3221SSean Christopherson /* 37445d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 37455d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 37465d6a3221SSean Christopherson */ 37475d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 37485d6a3221SSean Christopherson return false; 37495d6a3221SSean Christopherson 3750264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3751264d3dc1SLai Jiangshan return true; 3752264d3dc1SLai Jiangshan 3753264d3dc1SLai Jiangshan return false; 3754264d3dc1SLai Jiangshan } 3755264d3dc1SLai Jiangshan 3756c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3757c50d8ae3SPaolo Bonzini { 3758c50d8ae3SPaolo Bonzini int i; 3759c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3760c50d8ae3SPaolo Bonzini 3761347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3762c50d8ae3SPaolo Bonzini return; 3763c50d8ae3SPaolo Bonzini 3764b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3765c50d8ae3SPaolo Bonzini return; 3766c50d8ae3SPaolo Bonzini 3767c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3768c50d8ae3SPaolo Bonzini 37694d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3770b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3771e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3772c50d8ae3SPaolo Bonzini 3773264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3774c50d8ae3SPaolo Bonzini return; 3775c50d8ae3SPaolo Bonzini 3776531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 377765855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3778531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3779c50d8ae3SPaolo Bonzini return; 3780c50d8ae3SPaolo Bonzini } 3781c50d8ae3SPaolo Bonzini 3782531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3783c50d8ae3SPaolo Bonzini 3784c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3785c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3786c50d8ae3SPaolo Bonzini 3787c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 37882ca3129eSSean Christopherson root &= SPTE_BASE_ADDR_MASK; 3789e47c4aeeSSean Christopherson sp = to_shadow_page(root); 379065855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3791c50d8ae3SPaolo Bonzini } 3792c50d8ae3SPaolo Bonzini } 3793c50d8ae3SPaolo Bonzini 3794531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3795c50d8ae3SPaolo Bonzini } 3796c50d8ae3SPaolo Bonzini 379761b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 379861b05a9fSLai Jiangshan { 379961b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 380061b05a9fSLai Jiangshan int i; 380161b05a9fSLai Jiangshan 380261b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 380361b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 380461b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 380561b05a9fSLai Jiangshan 380661b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 38070c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 380861b05a9fSLai Jiangshan } 380961b05a9fSLai Jiangshan 38101f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 38115b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3812c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3813c50d8ae3SPaolo Bonzini { 3814c50d8ae3SPaolo Bonzini if (exception) 3815c50d8ae3SPaolo Bonzini exception->error_code = 0; 3816c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3817c50d8ae3SPaolo Bonzini } 3818c50d8ae3SPaolo Bonzini 3819c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3820c50d8ae3SPaolo Bonzini { 3821c50d8ae3SPaolo Bonzini /* 3822c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3823c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3824c50d8ae3SPaolo Bonzini */ 3825c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3826c50d8ae3SPaolo Bonzini return false; 3827c50d8ae3SPaolo Bonzini 3828c50d8ae3SPaolo Bonzini if (direct) 3829c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3830c50d8ae3SPaolo Bonzini 3831c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3832c50d8ae3SPaolo Bonzini } 3833c50d8ae3SPaolo Bonzini 383495fb5b02SBen Gardon /* 383595fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 383695fb5b02SBen Gardon * That SPTE may be non-present. 3837c5c8c7c5SDavid Matlack * 3838c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 383995fb5b02SBen Gardon */ 384039b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3841c50d8ae3SPaolo Bonzini { 3842c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 38432aa07893SSean Christopherson int leaf = -1; 384495fb5b02SBen Gardon u64 spte; 3845c50d8ae3SPaolo Bonzini 384639b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 384739b4d43eSSean Christopherson *root_level = iterator.level; 3848c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3849c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 385095fb5b02SBen Gardon leaf = iterator.level; 3851c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3852c50d8ae3SPaolo Bonzini 3853dde81f94SSean Christopherson sptes[leaf] = spte; 385495fb5b02SBen Gardon } 385595fb5b02SBen Gardon 385695fb5b02SBen Gardon return leaf; 385795fb5b02SBen Gardon } 385895fb5b02SBen Gardon 38599aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 386095fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 386195fb5b02SBen Gardon { 3862dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 386395fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 386439b4d43eSSean Christopherson int root, leaf, level; 386595fb5b02SBen Gardon bool reserved = false; 386695fb5b02SBen Gardon 3867c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3868c5c8c7c5SDavid Matlack 386963c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 387039b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 387195fb5b02SBen Gardon else 387239b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 387395fb5b02SBen Gardon 3874c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 3875c5c8c7c5SDavid Matlack 38762aa07893SSean Christopherson if (unlikely(leaf < 0)) { 38772aa07893SSean Christopherson *sptep = 0ull; 38782aa07893SSean Christopherson return reserved; 38792aa07893SSean Christopherson } 38802aa07893SSean Christopherson 38819aa41879SSean Christopherson *sptep = sptes[leaf]; 38829aa41879SSean Christopherson 38839aa41879SSean Christopherson /* 38849aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 38859aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 38869aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 38879aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 38889aa41879SSean Christopherson */ 38899aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 38909aa41879SSean Christopherson leaf++; 389195fb5b02SBen Gardon 389295fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 389395fb5b02SBen Gardon 38949aa41879SSean Christopherson for (level = root; level >= leaf; level--) 3895961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 3896c50d8ae3SPaolo Bonzini 3897c50d8ae3SPaolo Bonzini if (reserved) { 3898bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 3899c50d8ae3SPaolo Bonzini __func__, addr); 390095fb5b02SBen Gardon for (level = root; level >= leaf; level--) 3901bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 3902bb4cdf3aSSean Christopherson sptes[level], level, 3903961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 3904c50d8ae3SPaolo Bonzini } 3905ddce6208SSean Christopherson 3906c50d8ae3SPaolo Bonzini return reserved; 3907c50d8ae3SPaolo Bonzini } 3908c50d8ae3SPaolo Bonzini 3909c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3910c50d8ae3SPaolo Bonzini { 3911c50d8ae3SPaolo Bonzini u64 spte; 3912c50d8ae3SPaolo Bonzini bool reserved; 3913c50d8ae3SPaolo Bonzini 3914c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 3915c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3916c50d8ae3SPaolo Bonzini 391795fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 3918c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 3919c50d8ae3SPaolo Bonzini return -EINVAL; 3920c50d8ae3SPaolo Bonzini 3921c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 3922c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 39230a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 3924c50d8ae3SPaolo Bonzini 3925c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 3926c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 3927c50d8ae3SPaolo Bonzini 3928c50d8ae3SPaolo Bonzini if (direct) 3929c50d8ae3SPaolo Bonzini addr = 0; 3930c50d8ae3SPaolo Bonzini 3931c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 3932c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 3933c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3934c50d8ae3SPaolo Bonzini } 3935c50d8ae3SPaolo Bonzini 3936c50d8ae3SPaolo Bonzini /* 3937c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 3938c50d8ae3SPaolo Bonzini * the address. 3939c50d8ae3SPaolo Bonzini */ 3940c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3941c50d8ae3SPaolo Bonzini } 3942c50d8ae3SPaolo Bonzini 3943c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 3944b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 3945c50d8ae3SPaolo Bonzini { 3946b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 3947c50d8ae3SPaolo Bonzini return false; 3948c50d8ae3SPaolo Bonzini 3949b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 3950c50d8ae3SPaolo Bonzini return false; 3951c50d8ae3SPaolo Bonzini 3952c50d8ae3SPaolo Bonzini /* 3953c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 3954c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 3955c50d8ae3SPaolo Bonzini */ 39569d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 3957c50d8ae3SPaolo Bonzini return true; 3958c50d8ae3SPaolo Bonzini 3959c50d8ae3SPaolo Bonzini return false; 3960c50d8ae3SPaolo Bonzini } 3961c50d8ae3SPaolo Bonzini 3962c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 3963c50d8ae3SPaolo Bonzini { 3964c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 3965c50d8ae3SPaolo Bonzini u64 spte; 3966c50d8ae3SPaolo Bonzini 3967c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 39683e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 3969c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 3970c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3971c50d8ae3SPaolo Bonzini } 3972c50d8ae3SPaolo Bonzini 39736f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 39746f3c1fc5SLiang Zhang { 39756f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 39766f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 39776f3c1fc5SLiang Zhang 39786f3c1fc5SLiang Zhang if (id << 12 == 0) 39796f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 39806f3c1fc5SLiang Zhang 39816f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 39826f3c1fc5SLiang Zhang } 39836f3c1fc5SLiang Zhang 3984e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 39859f1a8526SSean Christopherson gfn_t gfn) 3986c50d8ae3SPaolo Bonzini { 3987c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 3988c50d8ae3SPaolo Bonzini 39896f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 3990c50d8ae3SPaolo Bonzini arch.gfn = gfn; 3991347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 3992d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 3993c50d8ae3SPaolo Bonzini 39949f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 39959f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 3996c50d8ae3SPaolo Bonzini } 3997c50d8ae3SPaolo Bonzini 39988a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 39998a009d5bSSean Christopherson { 40008a009d5bSSean Christopherson int r; 40018a009d5bSSean Christopherson 40028a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 40038a009d5bSSean Christopherson work->wakeup_all) 40048a009d5bSSean Christopherson return; 40058a009d5bSSean Christopherson 40068a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 40078a009d5bSSean Christopherson if (unlikely(r)) 40088a009d5bSSean Christopherson return; 40098a009d5bSSean Christopherson 40108a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 40118a009d5bSSean Christopherson work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu)) 40128a009d5bSSean Christopherson return; 40138a009d5bSSean Christopherson 40148a009d5bSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true); 40158a009d5bSSean Christopherson } 40168a009d5bSSean Christopherson 40175276c616SSean Christopherson static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4018c50d8ae3SPaolo Bonzini { 4019e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4020c50d8ae3SPaolo Bonzini bool async; 4021c50d8ae3SPaolo Bonzini 4022e0c37868SSean Christopherson /* 4023e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4024e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4025e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4026e0c37868SSean Christopherson */ 4027e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 40285276c616SSean Christopherson return RET_PF_RETRY; 4029e0c37868SSean Christopherson 40309cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4031c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 40329cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4033e710c5f6SDavid Matlack fault->slot = NULL; 40343647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 40353647cd04SPaolo Bonzini fault->map_writable = false; 40365276c616SSean Christopherson return RET_PF_CONTINUE; 4037c50d8ae3SPaolo Bonzini } 40389cc13d60SMaxim Levitsky /* 40399cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 40409cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 40419cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 40429cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 40439cc13d60SMaxim Levitsky */ 40449cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 40455276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 40465276c616SSean Christopherson return RET_PF_EMULATE; 40479cc13d60SMaxim Levitsky } 4048c50d8ae3SPaolo Bonzini 4049c50d8ae3SPaolo Bonzini async = false; 40503647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, 40513647cd04SPaolo Bonzini fault->write, &fault->map_writable, 40523647cd04SPaolo Bonzini &fault->hva); 4053c50d8ae3SPaolo Bonzini if (!async) 40545276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4055c50d8ae3SPaolo Bonzini 40562839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 40573647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 40583647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 40593647cd04SPaolo Bonzini trace_kvm_async_pf_doublefault(fault->addr, fault->gfn); 4060c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 40615276c616SSean Christopherson return RET_PF_RETRY; 40625276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 40635276c616SSean Christopherson return RET_PF_RETRY; 40645276c616SSean Christopherson } 4065c50d8ae3SPaolo Bonzini } 4066c50d8ae3SPaolo Bonzini 40673647cd04SPaolo Bonzini fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, 40683647cd04SPaolo Bonzini fault->write, &fault->map_writable, 40693647cd04SPaolo Bonzini &fault->hva); 40705276c616SSean Christopherson return RET_PF_CONTINUE; 4071c50d8ae3SPaolo Bonzini } 4072c50d8ae3SPaolo Bonzini 4073a955cad8SSean Christopherson /* 4074a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4075a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4076a955cad8SSean Christopherson */ 4077a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4078a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 4079a955cad8SSean Christopherson { 4080b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 408118c841e1SSean Christopherson 408218c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 408318c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 408418c841e1SSean Christopherson return true; 408518c841e1SSean Christopherson 408618c841e1SSean Christopherson /* 408718c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 408818c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 408918c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 409018c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 409118c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 409218c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 409318c841e1SSean Christopherson */ 4094527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4095a955cad8SSean Christopherson return true; 4096a955cad8SSean Christopherson 4097a955cad8SSean Christopherson return fault->slot && 4098a955cad8SSean Christopherson mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4099a955cad8SSean Christopherson } 4100a955cad8SSean Christopherson 41014326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4102c50d8ae3SPaolo Bonzini { 410363c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4104c50d8ae3SPaolo Bonzini 41050f90e1c1SSean Christopherson unsigned long mmu_seq; 410683f06fa7SSean Christopherson int r; 4107c50d8ae3SPaolo Bonzini 41083c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4109e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4110e710c5f6SDavid Matlack 4111b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4112c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4113c50d8ae3SPaolo Bonzini 41143c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4115c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4116c4371c2aSSean Christopherson return r; 411783291445SSean Christopherson 4118378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4119c50d8ae3SPaolo Bonzini if (r) 4120c50d8ae3SPaolo Bonzini return r; 4121c50d8ae3SPaolo Bonzini 4122367fd790SSean Christopherson mmu_seq = vcpu->kvm->mmu_notifier_seq; 4123367fd790SSean Christopherson smp_rmb(); 4124367fd790SSean Christopherson 41255276c616SSean Christopherson r = kvm_faultin_pfn(vcpu, fault); 41265276c616SSean Christopherson if (r != RET_PF_CONTINUE) 41278f32d5e5SMaxim Levitsky return r; 4128367fd790SSean Christopherson 41295276c616SSean Christopherson r = handle_abnormal_pfn(vcpu, fault, ACC_ALL); 41305276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4131367fd790SSean Christopherson return r; 4132367fd790SSean Christopherson 4133367fd790SSean Christopherson r = RET_PF_RETRY; 4134a2855afcSBen Gardon 41350b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4136a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4137a2855afcSBen Gardon else 4138531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4139a2855afcSBen Gardon 4140a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4141367fd790SSean Christopherson goto out_unlock; 4142a955cad8SSean Christopherson 41437bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 41447bd7ded6SSean Christopherson if (r) 4145367fd790SSean Christopherson goto out_unlock; 4146bb18842eSBen Gardon 41470b873fd7SDavid Matlack if (is_tdp_mmu_fault) 41482f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4149bb18842eSBen Gardon else 415043b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 41510f90e1c1SSean Christopherson 4152367fd790SSean Christopherson out_unlock: 41530b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4154a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4155a2855afcSBen Gardon else 4156531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 41573647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4158367fd790SSean Christopherson return r; 4159c50d8ae3SPaolo Bonzini } 4160c50d8ae3SPaolo Bonzini 4161c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4162c501040aSPaolo Bonzini struct kvm_page_fault *fault) 41630f90e1c1SSean Christopherson { 41644326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 41650f90e1c1SSean Christopherson 41660f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 41674326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 41684326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 41690f90e1c1SSean Christopherson } 41700f90e1c1SSean Christopherson 4171c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4172c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4173c50d8ae3SPaolo Bonzini { 4174c50d8ae3SPaolo Bonzini int r = 1; 41759ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4176c50d8ae3SPaolo Bonzini 4177736c291cSSean Christopherson #ifndef CONFIG_X86_64 4178736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4179736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4180736c291cSSean Christopherson return -EFAULT; 4181736c291cSSean Christopherson #endif 4182736c291cSSean Christopherson 4183c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 41849ce372b3SVitaly Kuznetsov if (!flags) { 4185c50d8ae3SPaolo Bonzini trace_kvm_page_fault(fault_address, error_code); 4186c50d8ae3SPaolo Bonzini 4187c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4188c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4189c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4190c50d8ae3SPaolo Bonzini insn_len); 41919ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 419268fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4193c50d8ae3SPaolo Bonzini local_irq_disable(); 41946bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4195c50d8ae3SPaolo Bonzini local_irq_enable(); 41969ce372b3SVitaly Kuznetsov } else { 41979ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4198c50d8ae3SPaolo Bonzini } 41999ce372b3SVitaly Kuznetsov 4200c50d8ae3SPaolo Bonzini return r; 4201c50d8ae3SPaolo Bonzini } 4202c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4203c50d8ae3SPaolo Bonzini 4204c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4205c50d8ae3SPaolo Bonzini { 42064326e57eSPaolo Bonzini while (fault->max_level > PG_LEVEL_4K) { 42074326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 42084326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4209c50d8ae3SPaolo Bonzini 4210cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4211cb9b88c6SSean Christopherson break; 42124326e57eSPaolo Bonzini 42134326e57eSPaolo Bonzini --fault->max_level; 4214c50d8ae3SPaolo Bonzini } 4215c50d8ae3SPaolo Bonzini 42164326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4217c50d8ae3SPaolo Bonzini } 4218c50d8ae3SPaolo Bonzini 421984a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4220c50d8ae3SPaolo Bonzini { 4221c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4222c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4223c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 42245efac074SPaolo Bonzini context->invlpg = NULL; 4225c50d8ae3SPaolo Bonzini } 4226c50d8ae3SPaolo Bonzini 4227be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 42280be44352SSean Christopherson union kvm_mmu_page_role role) 42290be44352SSean Christopherson { 4230be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 42315499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4232e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 42330be44352SSean Christopherson } 42340be44352SSean Christopherson 4235c50d8ae3SPaolo Bonzini /* 42365499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 42375499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 42385499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 42395499ea73SPaolo Bonzini * true is returned. 42405499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 42415499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4242c50d8ae3SPaolo Bonzini */ 42435499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 42445499ea73SPaolo Bonzini gpa_t new_pgd, 4245c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4246c50d8ae3SPaolo Bonzini { 4247c50d8ae3SPaolo Bonzini uint i; 4248c50d8ae3SPaolo Bonzini 4249b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 42500be44352SSean Christopherson return true; 42510be44352SSean Christopherson 4252c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 42535499ea73SPaolo Bonzini /* 42545499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 42555499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 42565499ea73SPaolo Bonzini * 0 C 1 2 3 42575499ea73SPaolo Bonzini * 1 C 0 2 3 42585499ea73SPaolo Bonzini * 2 C 0 1 3 42595499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 42605499ea73SPaolo Bonzini */ 4261b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4262b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 42635499ea73SPaolo Bonzini return true; 4264c50d8ae3SPaolo Bonzini } 4265c50d8ae3SPaolo Bonzini 42665499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 42675499ea73SPaolo Bonzini return false; 4268c50d8ae3SPaolo Bonzini } 4269c50d8ae3SPaolo Bonzini 4270c50d8ae3SPaolo Bonzini /* 42715499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 42725499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 42735499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 42745499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 42755499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 42765499ea73SPaolo Bonzini */ 42775499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 42785499ea73SPaolo Bonzini gpa_t new_pgd, 42795499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 42805499ea73SPaolo Bonzini { 42815499ea73SPaolo Bonzini uint i; 42825499ea73SPaolo Bonzini 42835499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 42845499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 42855499ea73SPaolo Bonzini goto hit; 42865499ea73SPaolo Bonzini 42875499ea73SPaolo Bonzini return false; 42885499ea73SPaolo Bonzini 42895499ea73SPaolo Bonzini hit: 42905499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 42915499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 42925499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 42935499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 42945499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 42955499ea73SPaolo Bonzini return true; 42965499ea73SPaolo Bonzini } 42975499ea73SPaolo Bonzini 42985499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 42995499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 43005499ea73SPaolo Bonzini { 43015499ea73SPaolo Bonzini /* 43025499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4303c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4304c50d8ae3SPaolo Bonzini * later if necessary. 4305c50d8ae3SPaolo Bonzini */ 43065499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 43075499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4308c50d8ae3SPaolo Bonzini 43095499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 43105499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 43115499ea73SPaolo Bonzini else 43125499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4313c50d8ae3SPaolo Bonzini } 4314c50d8ae3SPaolo Bonzini 4315d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4316c50d8ae3SPaolo Bonzini { 43170c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 43187a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 43190c1c92f1SPaolo Bonzini 43205499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 43215499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4322b869855bSSean Christopherson return; 4323c50d8ae3SPaolo Bonzini } 4324c50d8ae3SPaolo Bonzini 4325c50d8ae3SPaolo Bonzini /* 4326b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4327b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4328527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4329527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4330b869855bSSean Christopherson */ 4331b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4332b869855bSSean Christopherson 4333b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4334b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4335b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4336b5129100SSean Christopherson } 4337b869855bSSean Christopherson 4338b869855bSSean Christopherson /* 4339b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4340b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4341b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4342b869855bSSean Christopherson * the shadow page tables. 4343c50d8ae3SPaolo Bonzini */ 4344c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4345c50d8ae3SPaolo Bonzini 4346daa5b6c1SBen Gardon /* 4347daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4348daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4349daa5b6c1SBen Gardon */ 4350daa5b6c1SBen Gardon if (!new_role.direct) 4351daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4352b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4353c50d8ae3SPaolo Bonzini } 4354be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4355c50d8ae3SPaolo Bonzini 4356c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4357c50d8ae3SPaolo Bonzini { 4358c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4359c50d8ae3SPaolo Bonzini } 4360c50d8ae3SPaolo Bonzini 4361c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4362c3e5e415SLai Jiangshan unsigned int access) 4363c50d8ae3SPaolo Bonzini { 4364c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4365c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4366c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4367c50d8ae3SPaolo Bonzini return true; 4368c50d8ae3SPaolo Bonzini } 4369c50d8ae3SPaolo Bonzini 4370c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4371c50d8ae3SPaolo Bonzini return true; 4372c50d8ae3SPaolo Bonzini } 4373c50d8ae3SPaolo Bonzini 4374c50d8ae3SPaolo Bonzini return false; 4375c50d8ae3SPaolo Bonzini } 4376c50d8ae3SPaolo Bonzini 4377c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4378c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4379c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4380c50d8ae3SPaolo Bonzini #undef PTTYPE 4381c50d8ae3SPaolo Bonzini 4382c50d8ae3SPaolo Bonzini #define PTTYPE 64 4383c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4384c50d8ae3SPaolo Bonzini #undef PTTYPE 4385c50d8ae3SPaolo Bonzini 4386c50d8ae3SPaolo Bonzini #define PTTYPE 32 4387c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4388c50d8ae3SPaolo Bonzini #undef PTTYPE 4389c50d8ae3SPaolo Bonzini 4390c50d8ae3SPaolo Bonzini static void 4391b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 43925b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4393c50d8ae3SPaolo Bonzini bool pse, bool amd) 4394c50d8ae3SPaolo Bonzini { 4395c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4396c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 43975b7f575cSSean Christopherson u64 high_bits_rsvd; 4398c50d8ae3SPaolo Bonzini 4399c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4400c50d8ae3SPaolo Bonzini 4401c50d8ae3SPaolo Bonzini if (!gbpages) 4402c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4403c50d8ae3SPaolo Bonzini 44045b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 44055b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 44065b7f575cSSean Christopherson else 44075b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 44085b7f575cSSean Christopherson 44095b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 44105b7f575cSSean Christopherson if (!nx) 44115b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 44125b7f575cSSean Christopherson 4413c50d8ae3SPaolo Bonzini /* 4414c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4415c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4416c50d8ae3SPaolo Bonzini */ 4417c50d8ae3SPaolo Bonzini if (amd) 4418c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4419c50d8ae3SPaolo Bonzini 4420c50d8ae3SPaolo Bonzini switch (level) { 4421c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4422c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4423c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4424c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4425c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4426c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4427c50d8ae3SPaolo Bonzini 4428c50d8ae3SPaolo Bonzini if (!pse) { 4429c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4430c50d8ae3SPaolo Bonzini break; 4431c50d8ae3SPaolo Bonzini } 4432c50d8ae3SPaolo Bonzini 4433c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4434c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4435c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4436c50d8ae3SPaolo Bonzini else 4437c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4438c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4439c50d8ae3SPaolo Bonzini break; 4440c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 44415b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 44425b7f575cSSean Christopherson high_bits_rsvd | 44435b7f575cSSean Christopherson rsvd_bits(5, 8) | 44445b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 44455b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 44465b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 44475b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4448c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4449c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4450c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4451c50d8ae3SPaolo Bonzini break; 4452c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 44535b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 44545b7f575cSSean Christopherson nonleaf_bit8_rsvd | 44555b7f575cSSean Christopherson rsvd_bits(7, 7); 4456c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4457c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4458df561f66SGustavo A. R. Silva fallthrough; 4459c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 44605b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 44615b7f575cSSean Christopherson nonleaf_bit8_rsvd | 44625b7f575cSSean Christopherson rsvd_bits(7, 7); 44635b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 44645b7f575cSSean Christopherson gbpages_bit_rsvd; 44655b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 44665b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4467c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4468c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 44695b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 44705b7f575cSSean Christopherson gbpages_bit_rsvd | 4471c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 44725b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4473c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4474c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4475c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4476c50d8ae3SPaolo Bonzini break; 4477c50d8ae3SPaolo Bonzini } 4478c50d8ae3SPaolo Bonzini } 4479c50d8ae3SPaolo Bonzini 448027de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 448127de9250SSean Christopherson { 448227de9250SSean Christopherson /* 448327de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 448427de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 448527de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 448627de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 448727de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 448827de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 448927de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 449027de9250SSean Christopherson */ 449127de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 449227de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 449327de9250SSean Christopherson } 449427de9250SSean Christopherson 4495c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4496c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4497c50d8ae3SPaolo Bonzini { 4498b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 44995b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 45004d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 450127de9250SSean Christopherson guest_can_use_gbpages(vcpu), 45024e9c0d80SSean Christopherson is_cr4_pse(context), 450323493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4504c50d8ae3SPaolo Bonzini } 4505c50d8ae3SPaolo Bonzini 4506c50d8ae3SPaolo Bonzini static void 4507c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 450884ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4509c50d8ae3SPaolo Bonzini { 45105b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 451184ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4512c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4513c50d8ae3SPaolo Bonzini 451484ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 451584ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 451684ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 451784ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 451884ea5c09SLai Jiangshan 45195b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 45205b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 452184ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 452284ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 45235b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4524c50d8ae3SPaolo Bonzini 4525c50d8ae3SPaolo Bonzini /* large page */ 4526c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4527c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 452884ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 452984ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4530c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4531c50d8ae3SPaolo Bonzini 4532c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4533c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4534c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4535c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4536c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4537c50d8ae3SPaolo Bonzini if (!execonly) { 4538c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4539c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4540c50d8ae3SPaolo Bonzini } 4541c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4542c50d8ae3SPaolo Bonzini } 4543c50d8ae3SPaolo Bonzini 4544c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 454584ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4546c50d8ae3SPaolo Bonzini { 4547c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 454884ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 454984ea5c09SLai Jiangshan huge_page_level); 4550c50d8ae3SPaolo Bonzini } 4551c50d8ae3SPaolo Bonzini 45526f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 45536f8e65a6SSean Christopherson { 45546f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 45556f8e65a6SSean Christopherson } 45566f8e65a6SSean Christopherson 4557c50d8ae3SPaolo Bonzini /* 4558c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4559c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4560c50d8ae3SPaolo Bonzini * follow the features in guest. 4561c50d8ae3SPaolo Bonzini */ 456216be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 456316be1d12SSean Christopherson struct kvm_mmu *context) 4564c50d8ae3SPaolo Bonzini { 45658c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 45668c985b2dSSean Christopherson bool is_amd = true; 45678c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 45688c985b2dSSean Christopherson bool is_pse = false; 4569c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4570c50d8ae3SPaolo Bonzini int i; 4571c50d8ae3SPaolo Bonzini 4572a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 45738c985b2dSSean Christopherson 4574c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4575b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4576a972e29cSPaolo Bonzini context->root_role.level, 45777a458f0eSPaolo Bonzini context->root_role.efer_nx, 457827de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4579c50d8ae3SPaolo Bonzini 4580c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4581c50d8ae3SPaolo Bonzini return; 4582c50d8ae3SPaolo Bonzini 4583a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4584e54f1ff2SKai Huang /* 4585e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4586e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4587e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4588e54f1ff2SKai Huang * not allowed to be set. 4589e54f1ff2SKai Huang */ 4590e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4591e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4592e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4593e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4594c50d8ae3SPaolo Bonzini } 4595c50d8ae3SPaolo Bonzini 4596c50d8ae3SPaolo Bonzini } 4597c50d8ae3SPaolo Bonzini 4598c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4599c50d8ae3SPaolo Bonzini { 4600c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4601c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4602c50d8ae3SPaolo Bonzini } 4603c50d8ae3SPaolo Bonzini 4604c50d8ae3SPaolo Bonzini /* 4605c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4606c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4607c50d8ae3SPaolo Bonzini */ 4608c50d8ae3SPaolo Bonzini static void 4609e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4610c50d8ae3SPaolo Bonzini { 4611c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4612c50d8ae3SPaolo Bonzini int i; 4613c50d8ae3SPaolo Bonzini 4614c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4615c50d8ae3SPaolo Bonzini 4616c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4617b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4618a972e29cSPaolo Bonzini context->root_role.level, false, 4619c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 46208c985b2dSSean Christopherson false, true); 4621c50d8ae3SPaolo Bonzini else 4622c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 462384ea5c09SLai Jiangshan reserved_hpa_bits(), false, 462484ea5c09SLai Jiangshan max_huge_page_level); 4625c50d8ae3SPaolo Bonzini 4626c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4627c50d8ae3SPaolo Bonzini return; 4628c50d8ae3SPaolo Bonzini 4629a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4630c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4631c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4632c50d8ae3SPaolo Bonzini } 4633c50d8ae3SPaolo Bonzini } 4634c50d8ae3SPaolo Bonzini 4635c50d8ae3SPaolo Bonzini /* 4636c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4637c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4638c50d8ae3SPaolo Bonzini */ 4639c50d8ae3SPaolo Bonzini static void 4640e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4641c50d8ae3SPaolo Bonzini { 4642c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 464384ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 464484ea5c09SLai Jiangshan max_huge_page_level); 4645c50d8ae3SPaolo Bonzini } 4646c50d8ae3SPaolo Bonzini 4647c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4648c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4649c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4650c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4651c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4652c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4653c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4654c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4655c50d8ae3SPaolo Bonzini 4656c50d8ae3SPaolo Bonzini 4657c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4658c50d8ae3SPaolo Bonzini { 4659c50d8ae3SPaolo Bonzini unsigned byte; 4660c50d8ae3SPaolo Bonzini 4661c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4662c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4663c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4664c50d8ae3SPaolo Bonzini 4665c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4666c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4667c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 466890599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4669c50d8ae3SPaolo Bonzini 4670c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4671c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4672c50d8ae3SPaolo Bonzini 4673c50d8ae3SPaolo Bonzini /* 4674c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4675c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4676c50d8ae3SPaolo Bonzini */ 4677c50d8ae3SPaolo Bonzini 4678c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4679c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4680c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4681c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4682c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4683c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4684c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4685c50d8ae3SPaolo Bonzini u8 smepf = 0; 4686c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4687c50d8ae3SPaolo Bonzini u8 smapf = 0; 4688c50d8ae3SPaolo Bonzini 4689c50d8ae3SPaolo Bonzini if (!ept) { 4690c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4691c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4692c50d8ae3SPaolo Bonzini 4693c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 469490599c28SSean Christopherson if (!efer_nx) 4695c50d8ae3SPaolo Bonzini ff = 0; 4696c50d8ae3SPaolo Bonzini 4697c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4698c50d8ae3SPaolo Bonzini if (!cr0_wp) 4699c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4700c50d8ae3SPaolo Bonzini 4701c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4702c50d8ae3SPaolo Bonzini if (cr4_smep) 4703c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4704c50d8ae3SPaolo Bonzini 4705c50d8ae3SPaolo Bonzini /* 4706c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4707c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4708c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4709c50d8ae3SPaolo Bonzini * conditions are true: 4710c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4711c50d8ae3SPaolo Bonzini * - A user page is accessed 4712c50d8ae3SPaolo Bonzini * - The access is not a fetch 47134f4aa80eSLai Jiangshan * - The access is supervisor mode 47144f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4715c50d8ae3SPaolo Bonzini * 471694b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 471794b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4718c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4719c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4720c50d8ae3SPaolo Bonzini */ 4721c50d8ae3SPaolo Bonzini if (cr4_smap) 4722c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4723c50d8ae3SPaolo Bonzini } 4724c50d8ae3SPaolo Bonzini 4725c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4726c50d8ae3SPaolo Bonzini } 4727c50d8ae3SPaolo Bonzini } 4728c50d8ae3SPaolo Bonzini 4729c50d8ae3SPaolo Bonzini /* 4730c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4731c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4732c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4733c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4734c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4735c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4736c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4737c50d8ae3SPaolo Bonzini * 4738c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4739c50d8ae3SPaolo Bonzini * page tables and the machine state: 4740c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4741c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4742c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4743c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4744c50d8ae3SPaolo Bonzini * 4745c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4746c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4747c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4748c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4749c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4750c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4751c50d8ae3SPaolo Bonzini * only will be masked away. 4752c50d8ae3SPaolo Bonzini */ 47532e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4754c50d8ae3SPaolo Bonzini { 4755c50d8ae3SPaolo Bonzini unsigned bit; 4756c50d8ae3SPaolo Bonzini bool wp; 4757c50d8ae3SPaolo Bonzini 4758c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4759a3ca5281SChenyi Qiang 4760a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4761c50d8ae3SPaolo Bonzini return; 4762c50d8ae3SPaolo Bonzini 47632e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4764c50d8ae3SPaolo Bonzini 4765c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4766c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4767c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4768c50d8ae3SPaolo Bonzini 4769c50d8ae3SPaolo Bonzini pfec = bit << 1; 4770c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4771c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4772c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4773c50d8ae3SPaolo Bonzini 4774c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4775c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4776c50d8ae3SPaolo Bonzini 4777c50d8ae3SPaolo Bonzini /* 4778c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4779c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4780c50d8ae3SPaolo Bonzini */ 4781c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4782c50d8ae3SPaolo Bonzini /* 4783c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4784c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4785c50d8ae3SPaolo Bonzini */ 4786c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4787c50d8ae3SPaolo Bonzini 4788c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4789c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4790c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4791c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4792c50d8ae3SPaolo Bonzini 4793c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4794c50d8ae3SPaolo Bonzini } 4795c50d8ae3SPaolo Bonzini } 4796c50d8ae3SPaolo Bonzini 4797533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4798533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4799c50d8ae3SPaolo Bonzini { 4800533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4801533f9a4bSSean Christopherson return; 4802c50d8ae3SPaolo Bonzini 4803c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 4804533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4805533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4806c50d8ae3SPaolo Bonzini } 4807c50d8ae3SPaolo Bonzini 4808fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4809c50d8ae3SPaolo Bonzini { 4810c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4811c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4812c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4813c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4814c50d8ae3SPaolo Bonzini } 4815c50d8ae3SPaolo Bonzini 481684a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4817c50d8ae3SPaolo Bonzini { 4818c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4819c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4820c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4821c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4822c50d8ae3SPaolo Bonzini } 4823c50d8ae3SPaolo Bonzini 48247a7ae829SPaolo Bonzini static union kvm_cpu_role 4825e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 4826e5ed0fb0SPaolo Bonzini { 48277a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4828e5ed0fb0SPaolo Bonzini 4829e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 4830e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 4831e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4832e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 4833e5ed0fb0SPaolo Bonzini 4834e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 4835e5ed0fb0SPaolo Bonzini role.base.direct = 1; 4836e5ed0fb0SPaolo Bonzini return role; 4837e5ed0fb0SPaolo Bonzini } 4838e5ed0fb0SPaolo Bonzini 4839e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 4840e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 4841e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 4842e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 4843e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 484460f3cb60SPaolo Bonzini 484560f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 484660f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 484760f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 484860f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 484960f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 485060f3cb60SPaolo Bonzini else 485160f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 4852e5ed0fb0SPaolo Bonzini 4853e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 4854e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 4855e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 4856e5ed0fb0SPaolo Bonzini 4857e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 4858e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 4859e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 4860e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 4861e5ed0fb0SPaolo Bonzini return role; 4862e5ed0fb0SPaolo Bonzini } 4863e5ed0fb0SPaolo Bonzini 4864d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 4865d468d94bSSean Christopherson { 4866746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 4867746700d2SWei Huang if (tdp_root_level) 4868746700d2SWei Huang return tdp_root_level; 4869746700d2SWei Huang 4870d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 487183013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 4872d468d94bSSean Christopherson return 4; 4873d468d94bSSean Christopherson 487483013059SSean Christopherson return max_tdp_level; 4875d468d94bSSean Christopherson } 4876d468d94bSSean Christopherson 48777a458f0eSPaolo Bonzini static union kvm_mmu_page_role 48788626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 48797a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 4880c50d8ae3SPaolo Bonzini { 48817a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 4882c50d8ae3SPaolo Bonzini 48837a458f0eSPaolo Bonzini role.access = ACC_ALL; 48847a458f0eSPaolo Bonzini role.cr0_wp = true; 48857a458f0eSPaolo Bonzini role.efer_nx = true; 48867a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 48877a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 488854275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 48897a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 48907a458f0eSPaolo Bonzini role.direct = true; 48917a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 4892c50d8ae3SPaolo Bonzini 4893c50d8ae3SPaolo Bonzini return role; 4894c50d8ae3SPaolo Bonzini } 4895c50d8ae3SPaolo Bonzini 489639e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 4897a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 4898c50d8ae3SPaolo Bonzini { 48998c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 49007a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 4901c50d8ae3SPaolo Bonzini 4902e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 49037a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 4904c50d8ae3SPaolo Bonzini return; 4905c50d8ae3SPaolo Bonzini 4906e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 49077a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 49087a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 4909c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 49105efac074SPaolo Bonzini context->invlpg = NULL; 4911d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 4912c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 4913c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 4914c50d8ae3SPaolo Bonzini 491536f26787SSean Christopherson if (!is_cr0_pg(context)) 4916c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 491736f26787SSean Christopherson else if (is_cr4_pae(context)) 4918c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4919f4bd6f73SSean Christopherson else 4920c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4921c50d8ae3SPaolo Bonzini 4922533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4923e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 4924c50d8ae3SPaolo Bonzini } 4925c50d8ae3SPaolo Bonzini 49268c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 49277a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 49287a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 4929c50d8ae3SPaolo Bonzini { 4930e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 49317a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 493218db1b17SSean Christopherson return; 4933c50d8ae3SPaolo Bonzini 4934e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 49357a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 493618db1b17SSean Christopherson 493736f26787SSean Christopherson if (!is_cr0_pg(context)) 493884a16226SSean Christopherson nonpaging_init_context(context); 493936f26787SSean Christopherson else if (is_cr4_pae(context)) 4940fe660f72SSean Christopherson paging64_init_context(context); 4941c50d8ae3SPaolo Bonzini else 494284a16226SSean Christopherson paging32_init_context(context); 4943c50d8ae3SPaolo Bonzini 4944533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 4945c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 4946c50d8ae3SPaolo Bonzini } 49470f04a2acSVitaly Kuznetsov 4948594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 4949a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 49500f04a2acSVitaly Kuznetsov { 49518c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 495256b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 495356b321f9SPaolo Bonzini 495456b321f9SPaolo Bonzini root_role = cpu_role.base; 495556b321f9SPaolo Bonzini 495656b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 495756b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 495856b321f9SPaolo Bonzini 495956b321f9SPaolo Bonzini /* 496056b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 496156b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 496256b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 496356b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 496456b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 496556b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 496656b321f9SPaolo Bonzini * MMU contexts. 496756b321f9SPaolo Bonzini */ 496856b321f9SPaolo Bonzini root_role.efer_nx = true; 49690f04a2acSVitaly Kuznetsov 49707a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 49710f04a2acSVitaly Kuznetsov } 49720f04a2acSVitaly Kuznetsov 4973dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 4974dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 49750f04a2acSVitaly Kuznetsov { 49768c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 4977594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 4978594e91a1SSean Christopherson .cr0 = cr0, 497928f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 4980594e91a1SSean Christopherson .efer = efer, 4981594e91a1SSean Christopherson }; 49827a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 498356b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 498456b321f9SPaolo Bonzini 498556b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 498656b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 498756b321f9SPaolo Bonzini 498856b321f9SPaolo Bonzini root_role = cpu_role.base; 498956b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 499084e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 499184e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 499284e5ffd0SLai Jiangshan root_role.passthrough = 1; 49930f04a2acSVitaly Kuznetsov 49947a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 4995d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 49960f04a2acSVitaly Kuznetsov } 49970f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 4998c50d8ae3SPaolo Bonzini 49997a7ae829SPaolo Bonzini static union kvm_cpu_role 5000c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5001bb1fcc70SSean Christopherson bool execonly, u8 level) 5002c50d8ae3SPaolo Bonzini { 50037a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5004c50d8ae3SPaolo Bonzini 5005daed87b8SPaolo Bonzini /* 5006daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5007daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5008daed87b8SPaolo Bonzini */ 5009daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5010bb1fcc70SSean Christopherson role.base.level = level; 5011bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5012c50d8ae3SPaolo Bonzini role.base.direct = false; 5013c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5014c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5015c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5016c50d8ae3SPaolo Bonzini 5017cd6767c3SSean Christopherson role.ext.word = 0; 5018c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5019cd6767c3SSean Christopherson role.ext.valid = 1; 5020c50d8ae3SPaolo Bonzini 5021c50d8ae3SPaolo Bonzini return role; 5022c50d8ae3SPaolo Bonzini } 5023c50d8ae3SPaolo Bonzini 5024c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5025cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5026cc022ae1SLai Jiangshan gpa_t new_eptp) 5027c50d8ae3SPaolo Bonzini { 50288c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5029bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 50307a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5031c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5032bb1fcc70SSean Christopherson execonly, level); 5033c50d8ae3SPaolo Bonzini 5034e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5035e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5036e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 50377a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 503818db1b17SSean Christopherson 5039c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5040c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5041c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 5042c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 5043347a0d0dSPaolo Bonzini 5044c596f147SSean Christopherson update_permission_bitmask(context, true); 504528f091bcSPaolo Bonzini context->pkru_mask = 0; 5046cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5047e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5048c50d8ae3SPaolo Bonzini } 50493cffc89dSPaolo Bonzini 5050d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 50513cffc89dSPaolo Bonzini } 5052c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5053c50d8ae3SPaolo Bonzini 505439e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5055a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5056c50d8ae3SPaolo Bonzini { 50578c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5058c50d8ae3SPaolo Bonzini 5059a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5060929d1cfaSPaolo Bonzini 5061d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5062c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5063c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5064c50d8ae3SPaolo Bonzini } 5065c50d8ae3SPaolo Bonzini 506639e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5067a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5068c50d8ae3SPaolo Bonzini { 5069c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5070c50d8ae3SPaolo Bonzini 5071e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5072c50d8ae3SPaolo Bonzini return; 5073c50d8ae3SPaolo Bonzini 5074e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5075d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5076c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5077c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5078c50d8ae3SPaolo Bonzini 5079c50d8ae3SPaolo Bonzini /* 50805efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 50815efac074SPaolo Bonzini * SPTEs. 50825efac074SPaolo Bonzini */ 50835efac074SPaolo Bonzini g_context->invlpg = NULL; 50845efac074SPaolo Bonzini 50855efac074SPaolo Bonzini /* 5086c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5087c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5088c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5089c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5090c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5091c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5092c50d8ae3SPaolo Bonzini */ 5093fa4b5588SSean Christopherson if (!is_paging(vcpu)) 50941f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5095fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 50961f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5097fa4b5588SSean Christopherson else if (is_pae(vcpu)) 50981f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5099fa4b5588SSean Christopherson else 51001f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5101fa4b5588SSean Christopherson 5102533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5103c50d8ae3SPaolo Bonzini } 5104c50d8ae3SPaolo Bonzini 5105c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5106c50d8ae3SPaolo Bonzini { 510739e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5108a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 510939e7e2bfSPaolo Bonzini 5110c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5111a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5112c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5113a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5114c50d8ae3SPaolo Bonzini else 5115a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5116c50d8ae3SPaolo Bonzini } 5117c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5118c50d8ae3SPaolo Bonzini 511949c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 512049c6f875SSean Christopherson { 512149c6f875SSean Christopherson /* 512249c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 512349c6f875SSean Christopherson * information is factored into reserved bit calculations. 5124feb627e8SVitaly Kuznetsov * 5125feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5126feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5127feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5128feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5129feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5130feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5131feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 513249c6f875SSean Christopherson */ 51337a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 51347a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 51357a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5136e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5137e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5138e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 513949c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 514063f5a190SSean Christopherson 514163f5a190SSean Christopherson /* 5142feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5143feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 514463f5a190SSean Christopherson */ 5145feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 514649c6f875SSean Christopherson } 514749c6f875SSean Christopherson 5148c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5149c50d8ae3SPaolo Bonzini { 5150c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5151c9060662SSean Christopherson kvm_init_mmu(vcpu); 5152c50d8ae3SPaolo Bonzini } 5153c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5154c50d8ae3SPaolo Bonzini 5155c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5156c50d8ae3SPaolo Bonzini { 5157c50d8ae3SPaolo Bonzini int r; 5158c50d8ae3SPaolo Bonzini 5159347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5160c50d8ae3SPaolo Bonzini if (r) 5161c50d8ae3SPaolo Bonzini goto out; 5162748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5163c50d8ae3SPaolo Bonzini if (r) 5164c50d8ae3SPaolo Bonzini goto out; 5165347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 51666e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 51676e6ec584SSean Christopherson else 51686e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5169c50d8ae3SPaolo Bonzini if (r) 5170c50d8ae3SPaolo Bonzini goto out; 5171a91f387bSSean Christopherson 5172a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5173a91f387bSSean Christopherson 5174727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5175db01416bSSean Christopherson 5176db01416bSSean Christopherson /* 5177db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5178db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5179db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5180db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5181db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5182db01416bSSean Christopherson */ 5183e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5184c50d8ae3SPaolo Bonzini out: 5185c50d8ae3SPaolo Bonzini return r; 5186c50d8ae3SPaolo Bonzini } 5187c50d8ae3SPaolo Bonzini 5188c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5189c50d8ae3SPaolo Bonzini { 51900c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 51910c1c92f1SPaolo Bonzini 51920c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5193b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 51940c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5195b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 51966d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5197c50d8ae3SPaolo Bonzini } 5198c50d8ae3SPaolo Bonzini 5199527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5200527d5cd7SSean Christopherson { 5201527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5202527d5cd7SSean Christopherson 5203527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5204527d5cd7SSean Christopherson return false; 5205527d5cd7SSean Christopherson 5206527d5cd7SSean Christopherson /* 5207527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5208527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5209527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5210527d5cd7SSean Christopherson * such false positives are relatively rare: 5211527d5cd7SSean Christopherson * 5212527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5213527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5214527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5215527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5216527d5cd7SSean Christopherson */ 5217527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5218527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5219527d5cd7SSean Christopherson } 5220527d5cd7SSean Christopherson 5221527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5222527d5cd7SSean Christopherson { 5223527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5224527d5cd7SSean Christopherson int i; 5225527d5cd7SSean Christopherson 5226527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5227527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5228527d5cd7SSean Christopherson 5229527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5230cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5231527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5232527d5cd7SSean Christopherson } 5233527d5cd7SSean Christopherson 5234527d5cd7SSean Christopherson if (roots_to_free) 5235527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5236527d5cd7SSean Christopherson } 5237527d5cd7SSean Christopherson 5238527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5239527d5cd7SSean Christopherson { 5240527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5241527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5242527d5cd7SSean Christopherson } 5243527d5cd7SSean Christopherson 5244c50d8ae3SPaolo Bonzini static bool need_remote_flush(u64 old, u64 new) 5245c50d8ae3SPaolo Bonzini { 5246c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old)) 5247c50d8ae3SPaolo Bonzini return false; 5248c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(new)) 5249c50d8ae3SPaolo Bonzini return true; 52502ca3129eSSean Christopherson if ((old ^ new) & SPTE_BASE_ADDR_MASK) 5251c50d8ae3SPaolo Bonzini return true; 5252c50d8ae3SPaolo Bonzini old ^= shadow_nx_mask; 5253c50d8ae3SPaolo Bonzini new ^= shadow_nx_mask; 52542ca3129eSSean Christopherson return (old & ~new & SPTE_PERM_MASK) != 0; 5255c50d8ae3SPaolo Bonzini } 5256c50d8ae3SPaolo Bonzini 5257c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5258c50d8ae3SPaolo Bonzini int *bytes) 5259c50d8ae3SPaolo Bonzini { 5260c50d8ae3SPaolo Bonzini u64 gentry = 0; 5261c50d8ae3SPaolo Bonzini int r; 5262c50d8ae3SPaolo Bonzini 5263c50d8ae3SPaolo Bonzini /* 5264c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5265c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5266c50d8ae3SPaolo Bonzini * when they have the same mode. 5267c50d8ae3SPaolo Bonzini */ 5268c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5269c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5270c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5271c50d8ae3SPaolo Bonzini *bytes = 8; 5272c50d8ae3SPaolo Bonzini } 5273c50d8ae3SPaolo Bonzini 5274c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5275c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5276c50d8ae3SPaolo Bonzini if (r) 5277c50d8ae3SPaolo Bonzini gentry = 0; 5278c50d8ae3SPaolo Bonzini } 5279c50d8ae3SPaolo Bonzini 5280c50d8ae3SPaolo Bonzini return gentry; 5281c50d8ae3SPaolo Bonzini } 5282c50d8ae3SPaolo Bonzini 5283c50d8ae3SPaolo Bonzini /* 5284c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5285c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5286c50d8ae3SPaolo Bonzini */ 5287c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5288c50d8ae3SPaolo Bonzini { 5289c50d8ae3SPaolo Bonzini /* 5290c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5291c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5292c50d8ae3SPaolo Bonzini */ 52933bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5294c50d8ae3SPaolo Bonzini return false; 5295c50d8ae3SPaolo Bonzini 5296c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5297c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5298c50d8ae3SPaolo Bonzini } 5299c50d8ae3SPaolo Bonzini 5300c50d8ae3SPaolo Bonzini /* 5301c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5302c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5303c50d8ae3SPaolo Bonzini */ 5304c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5305c50d8ae3SPaolo Bonzini int bytes) 5306c50d8ae3SPaolo Bonzini { 5307c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5308c50d8ae3SPaolo Bonzini 5309c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5310c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5311c50d8ae3SPaolo Bonzini 5312c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5313bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5314c50d8ae3SPaolo Bonzini 5315c50d8ae3SPaolo Bonzini /* 5316c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5317c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5318c50d8ae3SPaolo Bonzini */ 5319c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5320c50d8ae3SPaolo Bonzini return false; 5321c50d8ae3SPaolo Bonzini 5322c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5323c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5324c50d8ae3SPaolo Bonzini 5325c50d8ae3SPaolo Bonzini return misaligned; 5326c50d8ae3SPaolo Bonzini } 5327c50d8ae3SPaolo Bonzini 5328c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5329c50d8ae3SPaolo Bonzini { 5330c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5331c50d8ae3SPaolo Bonzini u64 *spte; 5332c50d8ae3SPaolo Bonzini int level; 5333c50d8ae3SPaolo Bonzini 5334c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5335c50d8ae3SPaolo Bonzini level = sp->role.level; 5336c50d8ae3SPaolo Bonzini *nspte = 1; 5337bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5338c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5339c50d8ae3SPaolo Bonzini /* 5340c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5341c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5342c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5343c50d8ae3SPaolo Bonzini */ 5344c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5345c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5346c50d8ae3SPaolo Bonzini page_offset <<= 1; 5347c50d8ae3SPaolo Bonzini *nspte = 2; 5348c50d8ae3SPaolo Bonzini } 5349c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5350c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5351c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5352c50d8ae3SPaolo Bonzini return NULL; 5353c50d8ae3SPaolo Bonzini } 5354c50d8ae3SPaolo Bonzini 5355c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5356c50d8ae3SPaolo Bonzini return spte; 5357c50d8ae3SPaolo Bonzini } 5358c50d8ae3SPaolo Bonzini 5359c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5360c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5361c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5362c50d8ae3SPaolo Bonzini { 5363c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5364c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5365c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5366c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5367c50d8ae3SPaolo Bonzini int npte; 536806152b2dSLai Jiangshan bool flush = false; 5369c50d8ae3SPaolo Bonzini 5370c50d8ae3SPaolo Bonzini /* 5371c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5372c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5373c50d8ae3SPaolo Bonzini */ 5374c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5375c50d8ae3SPaolo Bonzini return; 5376c50d8ae3SPaolo Bonzini 5377c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5378c50d8ae3SPaolo Bonzini 5379531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5380c50d8ae3SPaolo Bonzini 5381c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5382c50d8ae3SPaolo Bonzini 5383c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5384c50d8ae3SPaolo Bonzini 5385767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5386c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5387c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5388c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5389c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5390c50d8ae3SPaolo Bonzini continue; 5391c50d8ae3SPaolo Bonzini } 5392c50d8ae3SPaolo Bonzini 5393c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5394c50d8ae3SPaolo Bonzini if (!spte) 5395c50d8ae3SPaolo Bonzini continue; 5396c50d8ae3SPaolo Bonzini 5397c50d8ae3SPaolo Bonzini while (npte--) { 5398c50d8ae3SPaolo Bonzini entry = *spte; 53992de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5400c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5401c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 5402c50d8ae3SPaolo Bonzini if (need_remote_flush(entry, *spte)) 540306152b2dSLai Jiangshan flush = true; 5404c50d8ae3SPaolo Bonzini ++spte; 5405c50d8ae3SPaolo Bonzini } 5406c50d8ae3SPaolo Bonzini } 540706152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5408531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5409c50d8ae3SPaolo Bonzini } 5410c50d8ae3SPaolo Bonzini 54111075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5412c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5413c50d8ae3SPaolo Bonzini { 541492daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5415347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5416c50d8ae3SPaolo Bonzini 5417b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5418ddce6208SSean Christopherson return RET_PF_RETRY; 5419ddce6208SSean Christopherson 5420c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5421c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5422736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5423c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5424c50d8ae3SPaolo Bonzini goto emulate; 5425c50d8ae3SPaolo Bonzini } 5426c50d8ae3SPaolo Bonzini 5427c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 54287a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 54297a02674dSSean Christopherson lower_32_bits(error_code), false); 543019025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 54317b367bc9SSean Christopherson return -EIO; 5432c50d8ae3SPaolo Bonzini } 5433c50d8ae3SPaolo Bonzini 5434c50d8ae3SPaolo Bonzini if (r < 0) 5435c50d8ae3SPaolo Bonzini return r; 543683a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 543783a2ba4cSSean Christopherson return 1; 5438c50d8ae3SPaolo Bonzini 5439c50d8ae3SPaolo Bonzini /* 5440c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5441c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5442c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5443c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5444c50d8ae3SPaolo Bonzini * and resume the guest. 5445c50d8ae3SPaolo Bonzini */ 5446347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5447c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5448736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5449c50d8ae3SPaolo Bonzini return 1; 5450c50d8ae3SPaolo Bonzini } 5451c50d8ae3SPaolo Bonzini 5452c50d8ae3SPaolo Bonzini /* 5453c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5454c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5455c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5456c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5457c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5458c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5459c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5460c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5461c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5462c50d8ae3SPaolo Bonzini */ 5463736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 546492daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5465c50d8ae3SPaolo Bonzini emulate: 5466736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5467c50d8ae3SPaolo Bonzini insn_len); 5468c50d8ae3SPaolo Bonzini } 5469c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5470c50d8ae3SPaolo Bonzini 54715efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 54725efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5473c50d8ae3SPaolo Bonzini { 5474c50d8ae3SPaolo Bonzini int i; 5475c50d8ae3SPaolo Bonzini 54765efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 54775efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 54785efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5479c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5480c50d8ae3SPaolo Bonzini return; 5481c50d8ae3SPaolo Bonzini 5482e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 54835efac074SPaolo Bonzini } 54845efac074SPaolo Bonzini 54855efac074SPaolo Bonzini if (!mmu->invlpg) 54865efac074SPaolo Bonzini return; 54875efac074SPaolo Bonzini 54885efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5489b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5490c50d8ae3SPaolo Bonzini 5491c50d8ae3SPaolo Bonzini /* 5492c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5493c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5494c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5495c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5496c50d8ae3SPaolo Bonzini * just always sync it. 5497c50d8ae3SPaolo Bonzini * 5498c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5499c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5500c50d8ae3SPaolo Bonzini * for them. 5501c50d8ae3SPaolo Bonzini */ 5502c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5503c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5504c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 55055efac074SPaolo Bonzini } else { 55065efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 55075efac074SPaolo Bonzini } 55085efac074SPaolo Bonzini } 5509c50d8ae3SPaolo Bonzini 55105efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 55115efac074SPaolo Bonzini { 551205b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5513c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5514c50d8ae3SPaolo Bonzini } 5515c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5516c50d8ae3SPaolo Bonzini 55175efac074SPaolo Bonzini 5518c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5519c50d8ae3SPaolo Bonzini { 5520c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5521c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5522c50d8ae3SPaolo Bonzini uint i; 5523c50d8ae3SPaolo Bonzini 5524c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 55259f46c187SPaolo Bonzini if (mmu->invlpg) 5526b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5527c50d8ae3SPaolo Bonzini tlb_flush = true; 5528c50d8ae3SPaolo Bonzini } 5529c50d8ae3SPaolo Bonzini 5530c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5531c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5532be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 55339f46c187SPaolo Bonzini if (mmu->invlpg) 5534c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5535c50d8ae3SPaolo Bonzini tlb_flush = true; 5536c50d8ae3SPaolo Bonzini } 5537c50d8ae3SPaolo Bonzini } 5538c50d8ae3SPaolo Bonzini 5539c50d8ae3SPaolo Bonzini if (tlb_flush) 5540e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5541c50d8ae3SPaolo Bonzini 5542c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5543c50d8ae3SPaolo Bonzini 5544c50d8ae3SPaolo Bonzini /* 5545c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5546c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5547c50d8ae3SPaolo Bonzini * for them. 5548c50d8ae3SPaolo Bonzini */ 5549c50d8ae3SPaolo Bonzini } 5550c50d8ae3SPaolo Bonzini 5551746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5552746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5553c50d8ae3SPaolo Bonzini { 5554bde77235SSean Christopherson tdp_enabled = enable_tdp; 5555746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 555683013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5557703c335dSSean Christopherson 5558703c335dSSean Christopherson /* 55591d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5560703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5561703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5562703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5563703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5564703c335dSSean Christopherson */ 5565703c335dSSean Christopherson if (tdp_enabled) 55661d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5567703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 55681d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5569703c335dSSean Christopherson else 55701d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5571c50d8ae3SPaolo Bonzini } 5572bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5573c50d8ae3SPaolo Bonzini 5574c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5575269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5576269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5577269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5578c50d8ae3SPaolo Bonzini 5579c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5580c50d8ae3SPaolo Bonzini static __always_inline bool 5581269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5582c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 55831a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 55841a61b7dbSSean Christopherson bool flush) 5585c50d8ae3SPaolo Bonzini { 5586c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5587c50d8ae3SPaolo Bonzini 5588c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5589c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5590c50d8ae3SPaolo Bonzini if (iterator.rmap) 55910a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5592c50d8ae3SPaolo Bonzini 5593531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5594302695a5SSean Christopherson if (flush && flush_on_yield) { 5595c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5596c50d8ae3SPaolo Bonzini start_gfn, 5597c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5598c50d8ae3SPaolo Bonzini flush = false; 5599c50d8ae3SPaolo Bonzini } 5600531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5601c50d8ae3SPaolo Bonzini } 5602c50d8ae3SPaolo Bonzini } 5603c50d8ae3SPaolo Bonzini 5604c50d8ae3SPaolo Bonzini return flush; 5605c50d8ae3SPaolo Bonzini } 5606c50d8ae3SPaolo Bonzini 5607c50d8ae3SPaolo Bonzini static __always_inline bool 5608269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5609c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5610302695a5SSean Christopherson bool flush_on_yield) 5611c50d8ae3SPaolo Bonzini { 5612c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5613c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5614c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 56151a61b7dbSSean Christopherson flush_on_yield, false); 5616c50d8ae3SPaolo Bonzini } 5617c50d8ae3SPaolo Bonzini 5618c50d8ae3SPaolo Bonzini static __always_inline bool 5619610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5620302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5621c50d8ae3SPaolo Bonzini { 56223bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5623302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5624c50d8ae3SPaolo Bonzini } 5625c50d8ae3SPaolo Bonzini 5626c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5627c50d8ae3SPaolo Bonzini { 56284a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 56294a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5630c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 563103ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5632cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5633c50d8ae3SPaolo Bonzini } 5634c50d8ae3SPaolo Bonzini 563504d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5636c50d8ae3SPaolo Bonzini { 5637c50d8ae3SPaolo Bonzini struct page *page; 5638c50d8ae3SPaolo Bonzini int i; 5639c50d8ae3SPaolo Bonzini 5640b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5641b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 564204d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 564304d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 564404d28e37SSean Christopherson 564527f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 564627f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 564727f4fca2SLai Jiangshan return 0; 564827f4fca2SLai Jiangshan 5649c50d8ae3SPaolo Bonzini /* 5650c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5651c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5652c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5653c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 565404d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 565504d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 565604d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 565704d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 565884432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5659c50d8ae3SPaolo Bonzini */ 5660d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5661c50d8ae3SPaolo Bonzini return 0; 5662c50d8ae3SPaolo Bonzini 5663c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5664c50d8ae3SPaolo Bonzini if (!page) 5665c50d8ae3SPaolo Bonzini return -ENOMEM; 5666c50d8ae3SPaolo Bonzini 5667c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 56684a98623dSSean Christopherson 56694a98623dSSean Christopherson /* 56704a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 56714a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 56724a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 56734a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 56744a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 56754a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 56764a98623dSSean Christopherson */ 56774a98623dSSean Christopherson if (!tdp_enabled) 56784a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 56794a98623dSSean Christopherson else 5680e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 56814a98623dSSean Christopherson 5682c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5683c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5684c50d8ae3SPaolo Bonzini 5685c50d8ae3SPaolo Bonzini return 0; 5686c50d8ae3SPaolo Bonzini } 5687c50d8ae3SPaolo Bonzini 5688c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5689c50d8ae3SPaolo Bonzini { 5690c50d8ae3SPaolo Bonzini int ret; 5691c50d8ae3SPaolo Bonzini 56925962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 56935f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 56945f6078f9SSean Christopherson 56955962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 56965f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 56975962bfb7SSean Christopherson 569896880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 569996880883SSean Christopherson 5700c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5701c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5702c50d8ae3SPaolo Bonzini 570304d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5704c50d8ae3SPaolo Bonzini if (ret) 5705c50d8ae3SPaolo Bonzini return ret; 5706c50d8ae3SPaolo Bonzini 570704d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5708c50d8ae3SPaolo Bonzini if (ret) 5709c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5710c50d8ae3SPaolo Bonzini 5711c50d8ae3SPaolo Bonzini return ret; 5712c50d8ae3SPaolo Bonzini fail_allocate_root: 5713c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5714c50d8ae3SPaolo Bonzini return ret; 5715c50d8ae3SPaolo Bonzini } 5716c50d8ae3SPaolo Bonzini 5717c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5718c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5719c50d8ae3SPaolo Bonzini { 5720c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5721c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5722b28cb0cdSSean Christopherson bool unstable; 5723c50d8ae3SPaolo Bonzini 5724c50d8ae3SPaolo Bonzini restart: 5725c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5726c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5727c50d8ae3SPaolo Bonzini /* 5728c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5729c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5730c50d8ae3SPaolo Bonzini */ 5731c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5732c50d8ae3SPaolo Bonzini break; 5733c50d8ae3SPaolo Bonzini 5734c50d8ae3SPaolo Bonzini /* 5735f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5736f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5737f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5738c50d8ae3SPaolo Bonzini */ 5739f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5740c50d8ae3SPaolo Bonzini continue; 5741c50d8ae3SPaolo Bonzini 5742c50d8ae3SPaolo Bonzini /* 5743c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5744c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5745c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5746c50d8ae3SPaolo Bonzini * be in active use by the guest. 5747c50d8ae3SPaolo Bonzini */ 5748c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5749531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5750c50d8ae3SPaolo Bonzini batch = 0; 5751c50d8ae3SPaolo Bonzini goto restart; 5752c50d8ae3SPaolo Bonzini } 5753c50d8ae3SPaolo Bonzini 5754b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 5755b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 5756c50d8ae3SPaolo Bonzini batch += nr_zapped; 5757b28cb0cdSSean Christopherson 5758b28cb0cdSSean Christopherson if (unstable) 5759c50d8ae3SPaolo Bonzini goto restart; 5760c50d8ae3SPaolo Bonzini } 5761c50d8ae3SPaolo Bonzini 5762c50d8ae3SPaolo Bonzini /* 57637ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 57647ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 57657ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 57667ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 57677ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 57687ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 57697ae5840eSSean Christopherson * running with an obsolete MMU. 5770c50d8ae3SPaolo Bonzini */ 5771c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5772c50d8ae3SPaolo Bonzini } 5773c50d8ae3SPaolo Bonzini 5774c50d8ae3SPaolo Bonzini /* 5775c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5776c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5777c50d8ae3SPaolo Bonzini * 5778c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5779c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5780c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5781c50d8ae3SPaolo Bonzini * after calling the function. 5782c50d8ae3SPaolo Bonzini */ 5783c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5784c50d8ae3SPaolo Bonzini { 5785c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5786c50d8ae3SPaolo Bonzini 5787531810caSBen Gardon write_lock(&kvm->mmu_lock); 5788c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5789c50d8ae3SPaolo Bonzini 5790c50d8ae3SPaolo Bonzini /* 5791c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5792c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5793c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5794c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5795c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5796c50d8ae3SPaolo Bonzini */ 5797c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5798c50d8ae3SPaolo Bonzini 57992f6f66ccSSean Christopherson /* 58002f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 58012f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 58022f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 58032f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5804b7cccd39SBen Gardon */ 5805b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5806b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5807b7cccd39SBen Gardon 5808c50d8ae3SPaolo Bonzini /* 5809c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5810c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5811c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5812c50d8ae3SPaolo Bonzini * 5813c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5814c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5815c50d8ae3SPaolo Bonzini */ 5816527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5817c50d8ae3SPaolo Bonzini 5818c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5819faaf05b0SBen Gardon 5820531810caSBen Gardon write_unlock(&kvm->mmu_lock); 58214c6654bdSBen Gardon 5822f28e9c7fSSean Christopherson /* 5823f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5824f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5825f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5826f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5827f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5828f28e9c7fSSean Christopherson * lead to use-after-free. 5829f28e9c7fSSean Christopherson */ 583022b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 58314c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5832c50d8ae3SPaolo Bonzini } 5833c50d8ae3SPaolo Bonzini 5834c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5835c50d8ae3SPaolo Bonzini { 5836c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5837c50d8ae3SPaolo Bonzini } 5838c50d8ae3SPaolo Bonzini 5839c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5840c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5841c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5842c50d8ae3SPaolo Bonzini { 5843c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5844c50d8ae3SPaolo Bonzini } 5845c50d8ae3SPaolo Bonzini 5846a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5847c50d8ae3SPaolo Bonzini { 5848c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5849a1a39128SPaolo Bonzini int r; 5850c50d8ae3SPaolo Bonzini 5851a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5852a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5853a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5854ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5855ce25681dSSean Christopherson 5856a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5857a1a39128SPaolo Bonzini if (r < 0) 5858a1a39128SPaolo Bonzini return r; 5859fe5db27dSBen Gardon 5860c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5861c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5862c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5863a1a39128SPaolo Bonzini return 0; 5864c50d8ae3SPaolo Bonzini } 5865c50d8ae3SPaolo Bonzini 5866c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 5867c50d8ae3SPaolo Bonzini { 5868c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5869c50d8ae3SPaolo Bonzini 5870c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 5871fe5db27dSBen Gardon 5872fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 5873c50d8ae3SPaolo Bonzini } 5874c50d8ae3SPaolo Bonzini 587521fa3246SSean Christopherson static bool __kvm_zap_rmaps(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 587621fa3246SSean Christopherson { 587721fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 587821fa3246SSean Christopherson struct kvm_memslots *slots; 5879f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 588021fa3246SSean Christopherson bool flush = false; 588121fa3246SSean Christopherson gfn_t start, end; 5882f4209439SMaciej S. Szmigiero int i; 588321fa3246SSean Christopherson 588421fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 588521fa3246SSean Christopherson return flush; 588621fa3246SSean Christopherson 588721fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 588821fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 5889f4209439SMaciej S. Szmigiero 5890f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 5891f4209439SMaciej S. Szmigiero memslot = iter.slot; 589221fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 589321fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 5894f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 589521fa3246SSean Christopherson continue; 589621fa3246SSean Christopherson 589721fa3246SSean Christopherson flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, 58986ff94f27SDavid Matlack 589921fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 590021fa3246SSean Christopherson start, end - 1, true, flush); 590121fa3246SSean Christopherson } 590221fa3246SSean Christopherson } 590321fa3246SSean Christopherson 590421fa3246SSean Christopherson return flush; 590521fa3246SSean Christopherson } 590621fa3246SSean Christopherson 590788f58535SMaxim Levitsky /* 590888f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 590988f58535SMaxim Levitsky * (not including it) 591088f58535SMaxim Levitsky */ 5911c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 5912c50d8ae3SPaolo Bonzini { 591321fa3246SSean Christopherson bool flush; 5914c50d8ae3SPaolo Bonzini int i; 5915c50d8ae3SPaolo Bonzini 5916f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 5917f4209439SMaciej S. Szmigiero return; 5918f4209439SMaciej S. Szmigiero 5919531810caSBen Gardon write_lock(&kvm->mmu_lock); 59205a324c24SSean Christopherson 5921edb298c6SMaxim Levitsky kvm_inc_notifier_count(kvm, gfn_start, gfn_end); 5922edb298c6SMaxim Levitsky 592321fa3246SSean Christopherson flush = __kvm_zap_rmaps(kvm, gfn_start, gfn_end); 59246103bc07SBen Gardon 59256103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 59266103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 5927f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 5928f47e5bbbSSean Christopherson gfn_end, true, flush); 59296103bc07SBen Gardon } 59305a324c24SSean Christopherson 59315a324c24SSean Christopherson if (flush) 5932bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 5933bc3b3c10SSean Christopherson gfn_end - gfn_start); 59345a324c24SSean Christopherson 5935edb298c6SMaxim Levitsky kvm_dec_notifier_count(kvm, gfn_start, gfn_end); 5936edb298c6SMaxim Levitsky 59375a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 5938c50d8ae3SPaolo Bonzini } 5939c50d8ae3SPaolo Bonzini 5940c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 59410a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 5942269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 5943c50d8ae3SPaolo Bonzini { 59441346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 5945c50d8ae3SPaolo Bonzini } 5946c50d8ae3SPaolo Bonzini 5947c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 5948269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 59493c9bd400SJay Zhou int start_level) 5950c50d8ae3SPaolo Bonzini { 5951e2209710SBen Gardon bool flush = false; 5952c50d8ae3SPaolo Bonzini 5953e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 5954531810caSBen Gardon write_lock(&kvm->mmu_lock); 59553c9bd400SJay Zhou flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, 5956e2209710SBen Gardon start_level, KVM_MAX_HUGEPAGE_LEVEL, 5957e2209710SBen Gardon false); 5958531810caSBen Gardon write_unlock(&kvm->mmu_lock); 5959e2209710SBen Gardon } 5960c50d8ae3SPaolo Bonzini 596124ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 596224ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 596324ae4cfaSBen Gardon flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 596424ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 596524ae4cfaSBen Gardon } 596624ae4cfaSBen Gardon 5967c50d8ae3SPaolo Bonzini /* 59686ff94f27SDavid Matlack * Flush TLBs if any SPTEs had to be write-protected to ensure that 59696ff94f27SDavid Matlack * guest writes are reflected in the dirty bitmap before the memslot 59706ff94f27SDavid Matlack * update completes, i.e. before enabling dirty logging is visible to 59716ff94f27SDavid Matlack * userspace. 59726ff94f27SDavid Matlack * 59736ff94f27SDavid Matlack * Perform the TLB flush outside the mmu_lock to reduce the amount of 59746ff94f27SDavid Matlack * time the lock is held. However, this does mean that another CPU can 59756ff94f27SDavid Matlack * now grab mmu_lock and encounter a write-protected SPTE while CPUs 59766ff94f27SDavid Matlack * still have a writable mapping for the associated GFN in their TLB. 59776ff94f27SDavid Matlack * 59786ff94f27SDavid Matlack * This is safe but requires KVM to be careful when making decisions 59796ff94f27SDavid Matlack * based on the write-protection status of an SPTE. Specifically, KVM 59806ff94f27SDavid Matlack * also write-protects SPTEs to monitor changes to guest page tables 59816ff94f27SDavid Matlack * during shadow paging, and must guarantee no CPUs can write to those 59826ff94f27SDavid Matlack * page before the lock is dropped. As mentioned in the previous 59836ff94f27SDavid Matlack * paragraph, a write-protected SPTE is no guarantee that CPU cannot 59846ff94f27SDavid Matlack * perform writes. So to determine if a TLB flush is truly required, KVM 59856ff94f27SDavid Matlack * will clear a separate software-only bit (MMU-writable) and skip the 59866ff94f27SDavid Matlack * flush if-and-only-if this bit was already clear. 59876ff94f27SDavid Matlack * 598802844ac1SDavid Matlack * See is_writable_pte() for more details. 5989c50d8ae3SPaolo Bonzini */ 5990c50d8ae3SPaolo Bonzini if (flush) 59917f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 5992c50d8ae3SPaolo Bonzini } 5993c50d8ae3SPaolo Bonzini 5994cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 5995cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 5996cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 5997cb00a70bSDavid Matlack u64 start, u64 end, 5998cb00a70bSDavid Matlack int target_level) 5999cb00a70bSDavid Matlack { 6000cb00a70bSDavid Matlack if (is_tdp_mmu_enabled(kvm)) 6001cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, 6002cb00a70bSDavid Matlack target_level, false); 6003cb00a70bSDavid Matlack 6004cb00a70bSDavid Matlack /* 6005cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6006cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6007cb00a70bSDavid Matlack */ 6008cb00a70bSDavid Matlack } 6009cb00a70bSDavid Matlack 6010a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6011a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6012a3fe5dbdSDavid Matlack int target_level) 6013a3fe5dbdSDavid Matlack { 6014a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6015a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6016a3fe5dbdSDavid Matlack 6017a3fe5dbdSDavid Matlack if (is_tdp_mmu_enabled(kvm)) { 6018a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6019cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6020a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6021a3fe5dbdSDavid Matlack } 6022a3fe5dbdSDavid Matlack 6023a3fe5dbdSDavid Matlack /* 6024a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6025a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6026a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6027a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6028a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6029a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6030a3fe5dbdSDavid Matlack * SPTEs. 6031a3fe5dbdSDavid Matlack */ 6032a3fe5dbdSDavid Matlack } 6033a3fe5dbdSDavid Matlack 6034c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 60350a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6036269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6037c50d8ae3SPaolo Bonzini { 6038c50d8ae3SPaolo Bonzini u64 *sptep; 6039c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6040c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6041c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 6042c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6043c50d8ae3SPaolo Bonzini 6044c50d8ae3SPaolo Bonzini restart: 6045c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 604657354682SSean Christopherson sp = sptep_to_sp(sptep); 6047c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(*sptep); 6048c50d8ae3SPaolo Bonzini 6049c50d8ae3SPaolo Bonzini /* 6050c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6051c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6052c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6053c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6054c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6055c50d8ae3SPaolo Bonzini */ 60565d49f08cSSean Christopherson if (sp->role.direct && 60579eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 60589eba50f8SSean Christopherson pfn, PG_LEVEL_NUM)) { 605971f51d2cSMingwei Zhang pte_list_remove(kvm, rmap_head, sptep); 6060c50d8ae3SPaolo Bonzini 6061c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6062c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6063c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6064c50d8ae3SPaolo Bonzini else 6065c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6066c50d8ae3SPaolo Bonzini 6067c50d8ae3SPaolo Bonzini goto restart; 6068c50d8ae3SPaolo Bonzini } 6069c50d8ae3SPaolo Bonzini } 6070c50d8ae3SPaolo Bonzini 6071c50d8ae3SPaolo Bonzini return need_tlb_flush; 6072c50d8ae3SPaolo Bonzini } 6073c50d8ae3SPaolo Bonzini 6074c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6075269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6076c50d8ae3SPaolo Bonzini { 6077e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6078531810caSBen Gardon write_lock(&kvm->mmu_lock); 6079610265eaSDavid Matlack /* 6080610265eaSDavid Matlack * Zap only 4k SPTEs since the legacy MMU only supports dirty 6081610265eaSDavid Matlack * logging at a 4k granularity and never creates collapsible 6082610265eaSDavid Matlack * 2m SPTEs during dirty logging. 6083610265eaSDavid Matlack */ 60844b85c921SSean Christopherson if (slot_handle_level_4k(kvm, slot, kvm_mmu_zap_collapsible_spte, true)) 6085302695a5SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 6086531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6087e2209710SBen Gardon } 60882db6f772SBen Gardon 60892db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60902db6f772SBen Gardon read_lock(&kvm->mmu_lock); 60914b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 60922db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 60932db6f772SBen Gardon } 6094c50d8ae3SPaolo Bonzini } 6095c50d8ae3SPaolo Bonzini 6096b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 60976c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6098b3594ffbSSean Christopherson { 6099b3594ffbSSean Christopherson /* 61007f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6101302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 61027f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 61037f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 61047f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6105b3594ffbSSean Christopherson */ 6106b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6107cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6108cec37648SSean Christopherson memslot->npages); 6109b3594ffbSSean Christopherson } 6110b3594ffbSSean Christopherson 6111c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6112269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6113c50d8ae3SPaolo Bonzini { 6114e2209710SBen Gardon bool flush = false; 6115c50d8ae3SPaolo Bonzini 6116e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6117531810caSBen Gardon write_lock(&kvm->mmu_lock); 6118610265eaSDavid Matlack /* 6119610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6120610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6121610265eaSDavid Matlack */ 6122610265eaSDavid Matlack flush = slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6123531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6124e2209710SBen Gardon } 6125c50d8ae3SPaolo Bonzini 612624ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 612724ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 612824ae4cfaSBen Gardon flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 612924ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 613024ae4cfaSBen Gardon } 613124ae4cfaSBen Gardon 6132c50d8ae3SPaolo Bonzini /* 6133c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6134c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6135c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6136c50d8ae3SPaolo Bonzini * dirty_bitmap. 6137c50d8ae3SPaolo Bonzini */ 6138c50d8ae3SPaolo Bonzini if (flush) 61397f42aa76SSean Christopherson kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); 6140c50d8ae3SPaolo Bonzini } 6141c50d8ae3SPaolo Bonzini 6142c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6143c50d8ae3SPaolo Bonzini { 6144c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6145c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6146c50d8ae3SPaolo Bonzini int ign; 6147c50d8ae3SPaolo Bonzini 6148531810caSBen Gardon write_lock(&kvm->mmu_lock); 6149c50d8ae3SPaolo Bonzini restart: 6150c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6151f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6152c50d8ae3SPaolo Bonzini continue; 6153c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6154c50d8ae3SPaolo Bonzini goto restart; 6155531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6156c50d8ae3SPaolo Bonzini goto restart; 6157c50d8ae3SPaolo Bonzini } 6158c50d8ae3SPaolo Bonzini 6159c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6160faaf05b0SBen Gardon 6161897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6162faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6163faaf05b0SBen Gardon 6164531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6165c50d8ae3SPaolo Bonzini } 6166c50d8ae3SPaolo Bonzini 6167c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6168c50d8ae3SPaolo Bonzini { 6169c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6170c50d8ae3SPaolo Bonzini 6171c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6172c50d8ae3SPaolo Bonzini 6173c50d8ae3SPaolo Bonzini /* 6174c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6175c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6176c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6177c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6178c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6179c50d8ae3SPaolo Bonzini */ 6180c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6181c50d8ae3SPaolo Bonzini 6182c50d8ae3SPaolo Bonzini /* 6183c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6184c50d8ae3SPaolo Bonzini * zap all shadow pages. 6185c50d8ae3SPaolo Bonzini */ 6186c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6187c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6188c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6189c50d8ae3SPaolo Bonzini } 6190c50d8ae3SPaolo Bonzini } 6191c50d8ae3SPaolo Bonzini 6192c50d8ae3SPaolo Bonzini static unsigned long 6193c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6194c50d8ae3SPaolo Bonzini { 6195c50d8ae3SPaolo Bonzini struct kvm *kvm; 6196c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6197c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6198c50d8ae3SPaolo Bonzini 6199c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6200c50d8ae3SPaolo Bonzini 6201c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6202c50d8ae3SPaolo Bonzini int idx; 6203c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6204c50d8ae3SPaolo Bonzini 6205c50d8ae3SPaolo Bonzini /* 6206c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6207c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6208c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6209c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6210c50d8ae3SPaolo Bonzini */ 6211c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6212c50d8ae3SPaolo Bonzini break; 6213c50d8ae3SPaolo Bonzini /* 6214c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6215c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6216c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6217c50d8ae3SPaolo Bonzini * anyway. 6218c50d8ae3SPaolo Bonzini */ 6219c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6220c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6221c50d8ae3SPaolo Bonzini continue; 6222c50d8ae3SPaolo Bonzini 6223c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6224531810caSBen Gardon write_lock(&kvm->mmu_lock); 6225c50d8ae3SPaolo Bonzini 6226c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6227c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6228c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6229c50d8ae3SPaolo Bonzini goto unlock; 6230c50d8ae3SPaolo Bonzini } 6231c50d8ae3SPaolo Bonzini 6232ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6233c50d8ae3SPaolo Bonzini 6234c50d8ae3SPaolo Bonzini unlock: 6235531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6236c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6237c50d8ae3SPaolo Bonzini 6238c50d8ae3SPaolo Bonzini /* 6239c50d8ae3SPaolo Bonzini * unfair on small ones 6240c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6241c50d8ae3SPaolo Bonzini * sadness comes quickly 6242c50d8ae3SPaolo Bonzini */ 6243c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6244c50d8ae3SPaolo Bonzini break; 6245c50d8ae3SPaolo Bonzini } 6246c50d8ae3SPaolo Bonzini 6247c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6248c50d8ae3SPaolo Bonzini return freed; 6249c50d8ae3SPaolo Bonzini } 6250c50d8ae3SPaolo Bonzini 6251c50d8ae3SPaolo Bonzini static unsigned long 6252c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6253c50d8ae3SPaolo Bonzini { 6254c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6255c50d8ae3SPaolo Bonzini } 6256c50d8ae3SPaolo Bonzini 6257c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6258c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6259c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6260c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6261c50d8ae3SPaolo Bonzini }; 6262c50d8ae3SPaolo Bonzini 6263c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6264c50d8ae3SPaolo Bonzini { 6265c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6266c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6267c50d8ae3SPaolo Bonzini } 6268c50d8ae3SPaolo Bonzini 6269c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6270c50d8ae3SPaolo Bonzini { 6271c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6272c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6273c50d8ae3SPaolo Bonzini } 6274c50d8ae3SPaolo Bonzini 6275c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6276c50d8ae3SPaolo Bonzini { 6277c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6278c50d8ae3SPaolo Bonzini } 6279c50d8ae3SPaolo Bonzini 6280c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6281c50d8ae3SPaolo Bonzini { 6282c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6283c50d8ae3SPaolo Bonzini bool new_val; 6284c50d8ae3SPaolo Bonzini 6285c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6286c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6287c50d8ae3SPaolo Bonzini new_val = 0; 6288c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6289c50d8ae3SPaolo Bonzini new_val = 1; 6290c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6291c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6292c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6293c50d8ae3SPaolo Bonzini return -EINVAL; 6294c50d8ae3SPaolo Bonzini 6295c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6296c50d8ae3SPaolo Bonzini 6297c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6298c50d8ae3SPaolo Bonzini struct kvm *kvm; 6299c50d8ae3SPaolo Bonzini 6300c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6301c50d8ae3SPaolo Bonzini 6302c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6303c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6304c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6305c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6306c50d8ae3SPaolo Bonzini 6307c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6308c50d8ae3SPaolo Bonzini } 6309c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6310c50d8ae3SPaolo Bonzini } 6311c50d8ae3SPaolo Bonzini 6312c50d8ae3SPaolo Bonzini return 0; 6313c50d8ae3SPaolo Bonzini } 6314c50d8ae3SPaolo Bonzini 63151d0e8480SSean Christopherson /* 63161d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 63171d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 63181d0e8480SSean Christopherson */ 63191d0e8480SSean Christopherson void kvm_mmu_x86_module_init(void) 6320c50d8ae3SPaolo Bonzini { 6321c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6322c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 63231d0e8480SSean Christopherson } 63241d0e8480SSean Christopherson 63251d0e8480SSean Christopherson /* 63261d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 63271d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 63281d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 63291d0e8480SSean Christopherson */ 63301d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 63311d0e8480SSean Christopherson { 63321d0e8480SSean Christopherson int ret = -ENOMEM; 6333c50d8ae3SPaolo Bonzini 6334c50d8ae3SPaolo Bonzini /* 6335c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6336c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6337c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6338c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6339c50d8ae3SPaolo Bonzini */ 6340c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6341c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 63427a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6343c50d8ae3SPaolo Bonzini 6344c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6345c50d8ae3SPaolo Bonzini 6346c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6347c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6348c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6349c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6350c50d8ae3SPaolo Bonzini goto out; 6351c50d8ae3SPaolo Bonzini 6352c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6353c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6354c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6355c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6356c50d8ae3SPaolo Bonzini goto out; 6357c50d8ae3SPaolo Bonzini 6358c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6359c50d8ae3SPaolo Bonzini goto out; 6360c50d8ae3SPaolo Bonzini 6361c50d8ae3SPaolo Bonzini ret = register_shrinker(&mmu_shrinker); 6362c50d8ae3SPaolo Bonzini if (ret) 6363c50d8ae3SPaolo Bonzini goto out; 6364c50d8ae3SPaolo Bonzini 6365c50d8ae3SPaolo Bonzini return 0; 6366c50d8ae3SPaolo Bonzini 6367c50d8ae3SPaolo Bonzini out: 6368c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6369c50d8ae3SPaolo Bonzini return ret; 6370c50d8ae3SPaolo Bonzini } 6371c50d8ae3SPaolo Bonzini 6372c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6373c50d8ae3SPaolo Bonzini { 6374c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6375c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6376c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6377c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6378c50d8ae3SPaolo Bonzini } 6379c50d8ae3SPaolo Bonzini 63801d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6381c50d8ae3SPaolo Bonzini { 6382c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6383c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6384c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6385c50d8ae3SPaolo Bonzini } 6386c50d8ae3SPaolo Bonzini 6387f47491d7SSean Christopherson /* 6388f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6389f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6390f47491d7SSean Christopherson */ 6391f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6392f47491d7SSean Christopherson { 6393f47491d7SSean Christopherson /* 6394f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6395f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6396f47491d7SSean Christopherson */ 6397f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6398f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6399f47491d7SSean Christopherson 6400f47491d7SSean Christopherson if (!enabled || !ratio) 6401f47491d7SSean Christopherson return false; 6402f47491d7SSean Christopherson 6403f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6404f47491d7SSean Christopherson if (!*period) { 6405f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6406f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6407f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6408f47491d7SSean Christopherson } 6409f47491d7SSean Christopherson return true; 6410f47491d7SSean Christopherson } 6411f47491d7SSean Christopherson 64124dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6413c50d8ae3SPaolo Bonzini { 64144dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 64154dfe4f40SJunaid Shahid uint old_period, new_period; 6416c50d8ae3SPaolo Bonzini int err; 6417c50d8ae3SPaolo Bonzini 6418f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 64194dfe4f40SJunaid Shahid 6420c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6421c50d8ae3SPaolo Bonzini if (err) 6422c50d8ae3SPaolo Bonzini return err; 6423c50d8ae3SPaolo Bonzini 6424f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 64254dfe4f40SJunaid Shahid 6426f47491d7SSean Christopherson if (is_recovery_enabled && 64274dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6428c50d8ae3SPaolo Bonzini struct kvm *kvm; 6429c50d8ae3SPaolo Bonzini 6430c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6431c50d8ae3SPaolo Bonzini 6432c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6433c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6434c50d8ae3SPaolo Bonzini 6435c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6436c50d8ae3SPaolo Bonzini } 6437c50d8ae3SPaolo Bonzini 6438c50d8ae3SPaolo Bonzini return err; 6439c50d8ae3SPaolo Bonzini } 6440c50d8ae3SPaolo Bonzini 6441c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6442c50d8ae3SPaolo Bonzini { 6443ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6444c50d8ae3SPaolo Bonzini int rcu_idx; 6445c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6446c50d8ae3SPaolo Bonzini unsigned int ratio; 6447c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6448048f4980SSean Christopherson bool flush = false; 6449c50d8ae3SPaolo Bonzini ulong to_zap; 6450c50d8ae3SPaolo Bonzini 6451c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6452531810caSBen Gardon write_lock(&kvm->mmu_lock); 6453c50d8ae3SPaolo Bonzini 6454bb95dfb9SSean Christopherson /* 6455bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6456bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6457bb95dfb9SSean Christopherson * callback. 6458bb95dfb9SSean Christopherson */ 6459bb95dfb9SSean Christopherson rcu_read_lock(); 6460bb95dfb9SSean Christopherson 6461c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6462ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 64637d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 64647d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 64657d919c7aSSean Christopherson break; 64667d919c7aSSean Christopherson 6467c50d8ae3SPaolo Bonzini /* 6468c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6469c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6470c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6471c50d8ae3SPaolo Bonzini */ 6472c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6473c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6474c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6475c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6476897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6477315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 64788d1a182eSBen Gardon } else { 6479c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6480c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 648129cf0f50SBen Gardon } 6482c50d8ae3SPaolo Bonzini 6483531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6484048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6485bb95dfb9SSean Christopherson rcu_read_unlock(); 6486bb95dfb9SSean Christopherson 6487531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6488048f4980SSean Christopherson flush = false; 6489bb95dfb9SSean Christopherson 6490bb95dfb9SSean Christopherson rcu_read_lock(); 6491c50d8ae3SPaolo Bonzini } 6492c50d8ae3SPaolo Bonzini } 6493048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6494c50d8ae3SPaolo Bonzini 6495bb95dfb9SSean Christopherson rcu_read_unlock(); 6496bb95dfb9SSean Christopherson 6497531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6498c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6499c50d8ae3SPaolo Bonzini } 6500c50d8ae3SPaolo Bonzini 6501c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6502c50d8ae3SPaolo Bonzini { 6503f47491d7SSean Christopherson bool enabled; 6504f47491d7SSean Christopherson uint period; 65054dfe4f40SJunaid Shahid 6506f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 65074dfe4f40SJunaid Shahid 6508f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6509c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6510c50d8ae3SPaolo Bonzini } 6511c50d8ae3SPaolo Bonzini 6512c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6513c50d8ae3SPaolo Bonzini { 6514c50d8ae3SPaolo Bonzini u64 start_time; 6515c50d8ae3SPaolo Bonzini long remaining_time; 6516c50d8ae3SPaolo Bonzini 6517c50d8ae3SPaolo Bonzini while (true) { 6518c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6519c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6520c50d8ae3SPaolo Bonzini 6521c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6522c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6523c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6524c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6525c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6526c50d8ae3SPaolo Bonzini } 6527c50d8ae3SPaolo Bonzini 6528c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6529c50d8ae3SPaolo Bonzini 6530c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6531c50d8ae3SPaolo Bonzini return 0; 6532c50d8ae3SPaolo Bonzini 6533c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6534c50d8ae3SPaolo Bonzini } 6535c50d8ae3SPaolo Bonzini } 6536c50d8ae3SPaolo Bonzini 6537c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6538c50d8ae3SPaolo Bonzini { 6539c50d8ae3SPaolo Bonzini int err; 6540c50d8ae3SPaolo Bonzini 6541c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6542c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6543c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6544c50d8ae3SPaolo Bonzini if (!err) 6545c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6546c50d8ae3SPaolo Bonzini 6547c50d8ae3SPaolo Bonzini return err; 6548c50d8ae3SPaolo Bonzini } 6549c50d8ae3SPaolo Bonzini 6550c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6551c50d8ae3SPaolo Bonzini { 6552c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6553c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6554c50d8ae3SPaolo Bonzini } 6555