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" 25b0b42197SPaolo Bonzini #include "smm.h" 262f728d66SSean Christopherson #include "kvm_emulate.h" 27c50d8ae3SPaolo Bonzini #include "cpuid.h" 285a9624afSPaolo Bonzini #include "spte.h" 29c50d8ae3SPaolo Bonzini 30c50d8ae3SPaolo Bonzini #include <linux/kvm_host.h> 31c50d8ae3SPaolo Bonzini #include <linux/types.h> 32c50d8ae3SPaolo Bonzini #include <linux/string.h> 33c50d8ae3SPaolo Bonzini #include <linux/mm.h> 34c50d8ae3SPaolo Bonzini #include <linux/highmem.h> 35c50d8ae3SPaolo Bonzini #include <linux/moduleparam.h> 36c50d8ae3SPaolo Bonzini #include <linux/export.h> 37c50d8ae3SPaolo Bonzini #include <linux/swap.h> 38c50d8ae3SPaolo Bonzini #include <linux/hugetlb.h> 39c50d8ae3SPaolo Bonzini #include <linux/compiler.h> 40c50d8ae3SPaolo Bonzini #include <linux/srcu.h> 41c50d8ae3SPaolo Bonzini #include <linux/slab.h> 42c50d8ae3SPaolo Bonzini #include <linux/sched/signal.h> 43c50d8ae3SPaolo Bonzini #include <linux/uaccess.h> 44c50d8ae3SPaolo Bonzini #include <linux/hash.h> 45c50d8ae3SPaolo Bonzini #include <linux/kern_levels.h> 46c50d8ae3SPaolo Bonzini #include <linux/kthread.h> 47c50d8ae3SPaolo Bonzini 48c50d8ae3SPaolo Bonzini #include <asm/page.h> 49eb243d1dSIngo Molnar #include <asm/memtype.h> 50c50d8ae3SPaolo Bonzini #include <asm/cmpxchg.h> 51c50d8ae3SPaolo Bonzini #include <asm/io.h> 524a98623dSSean Christopherson #include <asm/set_memory.h> 53c50d8ae3SPaolo Bonzini #include <asm/vmx.h> 54c50d8ae3SPaolo Bonzini #include <asm/kvm_page_track.h> 55c50d8ae3SPaolo Bonzini #include "trace.h" 56c50d8ae3SPaolo Bonzini 57c50d8ae3SPaolo Bonzini extern bool itlb_multihit_kvm_mitigation; 58c50d8ae3SPaolo Bonzini 59a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 604dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 61c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 62c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 63c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 64c50d8ae3SPaolo Bonzini #else 65c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 66c50d8ae3SPaolo Bonzini #endif 67c50d8ae3SPaolo Bonzini 68c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 694dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 70c50d8ae3SPaolo Bonzini 71d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 72c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 73c50d8ae3SPaolo Bonzini .get = param_get_bool, 74c50d8ae3SPaolo Bonzini }; 75c50d8ae3SPaolo Bonzini 764dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 774dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 78c50d8ae3SPaolo Bonzini .get = param_get_uint, 79c50d8ae3SPaolo Bonzini }; 80c50d8ae3SPaolo Bonzini 81c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 82c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 834dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 84c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 85c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 864dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 874dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 884dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 89c50d8ae3SPaolo Bonzini 9071fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9171fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9271fe7013SSean Christopherson 93c50d8ae3SPaolo Bonzini /* 94c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 95c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 96c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 97c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 98c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 99c50d8ae3SPaolo Bonzini */ 100c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 101c50d8ae3SPaolo Bonzini 1021d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 103746700d2SWei Huang static int tdp_root_level __read_mostly; 10483013059SSean Christopherson static int max_tdp_level __read_mostly; 105703c335dSSean Christopherson 106c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1075a9624afSPaolo Bonzini bool dbg = 0; 108c50d8ae3SPaolo Bonzini module_param(dbg, bool, 0644); 109c50d8ae3SPaolo Bonzini #endif 110c50d8ae3SPaolo Bonzini 111c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 112c50d8ae3SPaolo Bonzini 113c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 114c50d8ae3SPaolo Bonzini 115dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 11613236e25SPeter Xu #define PTE_LIST_EXT 14 117c50d8ae3SPaolo Bonzini 11813236e25SPeter Xu /* 11913236e25SPeter Xu * Slight optimization of cacheline layout, by putting `more' and `spte_count' 12013236e25SPeter Xu * at the start; then accessing it will only use one single cacheline for 12113236e25SPeter Xu * either full (entries==PTE_LIST_EXT) case or entries<=6. 12213236e25SPeter Xu */ 123c50d8ae3SPaolo Bonzini struct pte_list_desc { 124c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 12513236e25SPeter Xu /* 12613236e25SPeter Xu * Stores number of entries stored in the pte_list_desc. No need to be 12713236e25SPeter Xu * u64 but just for easier alignment. When PTE_LIST_EXT, means full. 12813236e25SPeter Xu */ 12913236e25SPeter Xu u64 spte_count; 13013236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 131c50d8ae3SPaolo Bonzini }; 132c50d8ae3SPaolo Bonzini 133c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 134c50d8ae3SPaolo Bonzini u64 addr; 135c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 136c50d8ae3SPaolo Bonzini u64 *sptep; 137c50d8ae3SPaolo Bonzini int level; 138c50d8ae3SPaolo Bonzini unsigned index; 139c50d8ae3SPaolo Bonzini }; 140c50d8ae3SPaolo Bonzini 141c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 142c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 143c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 144c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 145c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 146c50d8ae3SPaolo Bonzini 147c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 148c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 149c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 150c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 151c50d8ae3SPaolo Bonzini 152c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 153c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 154c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 155c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 156c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 157c50d8ae3SPaolo Bonzini 158c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 15902c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 160c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 161c50d8ae3SPaolo Bonzini 162c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 163c50d8ae3SPaolo Bonzini 164594e91a1SSean Christopherson struct kvm_mmu_role_regs { 165594e91a1SSean Christopherson const unsigned long cr0; 166594e91a1SSean Christopherson const unsigned long cr4; 167594e91a1SSean Christopherson const u64 efer; 168594e91a1SSean Christopherson }; 169594e91a1SSean Christopherson 170c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 171c50d8ae3SPaolo Bonzini #include "mmutrace.h" 172c50d8ae3SPaolo Bonzini 173594e91a1SSean Christopherson /* 174594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1757a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 176594e91a1SSean Christopherson * the single source of truth for the MMU's state. 177594e91a1SSean Christopherson */ 178594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 17982ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 18082ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 181594e91a1SSean Christopherson { \ 182594e91a1SSean Christopherson return !!(regs->reg & flag); \ 183594e91a1SSean Christopherson } 184594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 185594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 186594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 187594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 188594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 189594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 190594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 191594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 192594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 193594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 194594e91a1SSean Christopherson 19560667724SSean Christopherson /* 19660667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 19760667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 19860667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 19960667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 20060667724SSean Christopherson */ 20160667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2024ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 20360667724SSean Christopherson { \ 204e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 20560667724SSean Christopherson } 20660667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 20760667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 20860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 20960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 21060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 21160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 21260667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 21356b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 21460667724SSean Christopherson 215faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 216faf72962SPaolo Bonzini { 217faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 218faf72962SPaolo Bonzini } 219faf72962SPaolo Bonzini 220faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 221faf72962SPaolo Bonzini { 222faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 223faf72962SPaolo Bonzini } 224faf72962SPaolo Bonzini 225594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 226594e91a1SSean Christopherson { 227594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 228594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 229594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 230594e91a1SSean Christopherson .efer = vcpu->arch.efer, 231594e91a1SSean Christopherson }; 232594e91a1SSean Christopherson 233594e91a1SSean Christopherson return regs; 234594e91a1SSean Christopherson } 235c50d8ae3SPaolo Bonzini 236c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 237c50d8ae3SPaolo Bonzini { 238afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 239c50d8ae3SPaolo Bonzini } 240c50d8ae3SPaolo Bonzini 241c50d8ae3SPaolo Bonzini static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm, 242c50d8ae3SPaolo Bonzini struct kvm_tlb_range *range) 243c50d8ae3SPaolo Bonzini { 244c50d8ae3SPaolo Bonzini int ret = -ENOTSUPP; 245c50d8ae3SPaolo Bonzini 246afaf0b2fSSean Christopherson if (range && kvm_x86_ops.tlb_remote_flush_with_range) 247b3646477SJason Baron ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range); 248c50d8ae3SPaolo Bonzini 249c50d8ae3SPaolo Bonzini if (ret) 250c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 251c50d8ae3SPaolo Bonzini } 252c50d8ae3SPaolo Bonzini 2532f2fad08SBen Gardon void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 254c50d8ae3SPaolo Bonzini u64 start_gfn, u64 pages) 255c50d8ae3SPaolo Bonzini { 256c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 257c50d8ae3SPaolo Bonzini 258c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 259c50d8ae3SPaolo Bonzini range.pages = pages; 260c50d8ae3SPaolo Bonzini 261c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_range(kvm, &range); 262c50d8ae3SPaolo Bonzini } 263c50d8ae3SPaolo Bonzini 2648f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2658f79b064SBen Gardon unsigned int access) 2668f79b064SBen Gardon { 267c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2688f79b064SBen Gardon 269c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 270c236d962SSean Christopherson mmu_spte_set(sptep, spte); 271c50d8ae3SPaolo Bonzini } 272c50d8ae3SPaolo Bonzini 273c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 274c50d8ae3SPaolo Bonzini { 275c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 276c50d8ae3SPaolo Bonzini 2778a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 278c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 279c50d8ae3SPaolo Bonzini 280c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 281c50d8ae3SPaolo Bonzini } 282c50d8ae3SPaolo Bonzini 283c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 284c50d8ae3SPaolo Bonzini { 285c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 286c50d8ae3SPaolo Bonzini } 287c50d8ae3SPaolo Bonzini 288c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 289c50d8ae3SPaolo Bonzini { 290c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 291c50d8ae3SPaolo Bonzini 292c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 293c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 294c50d8ae3SPaolo Bonzini return false; 295c50d8ae3SPaolo Bonzini 296c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 297c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 298c50d8ae3SPaolo Bonzini 299c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 300c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 301c50d8ae3SPaolo Bonzini } 302c50d8ae3SPaolo Bonzini 303c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 304c50d8ae3SPaolo Bonzini { 305c50d8ae3SPaolo Bonzini return 1; 306c50d8ae3SPaolo Bonzini } 307c50d8ae3SPaolo Bonzini 308c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 309c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 310c50d8ae3SPaolo Bonzini { 311c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 312c50d8ae3SPaolo Bonzini } 313c50d8ae3SPaolo Bonzini 314c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 315c50d8ae3SPaolo Bonzini { 316c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 317c50d8ae3SPaolo Bonzini } 318c50d8ae3SPaolo Bonzini 319c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 320c50d8ae3SPaolo Bonzini { 321c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 322c50d8ae3SPaolo Bonzini } 323c50d8ae3SPaolo Bonzini 324c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 325c50d8ae3SPaolo Bonzini { 326c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 327c50d8ae3SPaolo Bonzini } 328c50d8ae3SPaolo Bonzini #else 329c50d8ae3SPaolo Bonzini union split_spte { 330c50d8ae3SPaolo Bonzini struct { 331c50d8ae3SPaolo Bonzini u32 spte_low; 332c50d8ae3SPaolo Bonzini u32 spte_high; 333c50d8ae3SPaolo Bonzini }; 334c50d8ae3SPaolo Bonzini u64 spte; 335c50d8ae3SPaolo Bonzini }; 336c50d8ae3SPaolo Bonzini 337c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 338c50d8ae3SPaolo Bonzini { 33957354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 340c50d8ae3SPaolo Bonzini 341c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 342c50d8ae3SPaolo Bonzini return; 343c50d8ae3SPaolo Bonzini 344c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 345c50d8ae3SPaolo Bonzini smp_wmb(); 346c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 347c50d8ae3SPaolo Bonzini } 348c50d8ae3SPaolo Bonzini 349c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 350c50d8ae3SPaolo Bonzini { 351c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 352c50d8ae3SPaolo Bonzini 353c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 354c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 355c50d8ae3SPaolo Bonzini 356c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 357c50d8ae3SPaolo Bonzini 358c50d8ae3SPaolo Bonzini /* 359c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 360c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 361c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 362c50d8ae3SPaolo Bonzini */ 363c50d8ae3SPaolo Bonzini smp_wmb(); 364c50d8ae3SPaolo Bonzini 365c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 366c50d8ae3SPaolo Bonzini } 367c50d8ae3SPaolo Bonzini 368c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 369c50d8ae3SPaolo Bonzini { 370c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 371c50d8ae3SPaolo Bonzini 372c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 373c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 374c50d8ae3SPaolo Bonzini 375c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 376c50d8ae3SPaolo Bonzini 377c50d8ae3SPaolo Bonzini /* 378c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 379c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 380c50d8ae3SPaolo Bonzini */ 381c50d8ae3SPaolo Bonzini smp_wmb(); 382c50d8ae3SPaolo Bonzini 383c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 384c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 385c50d8ae3SPaolo Bonzini } 386c50d8ae3SPaolo Bonzini 387c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 388c50d8ae3SPaolo Bonzini { 389c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 390c50d8ae3SPaolo Bonzini 391c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 392c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 393c50d8ae3SPaolo Bonzini 394c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 395c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 396c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 397c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 398c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 399c50d8ae3SPaolo Bonzini 400c50d8ae3SPaolo Bonzini return orig.spte; 401c50d8ae3SPaolo Bonzini } 402c50d8ae3SPaolo Bonzini 403c50d8ae3SPaolo Bonzini /* 404c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 405c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 406c50d8ae3SPaolo Bonzini * 407aed02fe3SSean Christopherson * An spte tlb flush may be pending, because kvm_set_pte_rmap 408c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 409c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 410c50d8ae3SPaolo Bonzini * 411c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 412c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 413c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 414c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 415c50d8ae3SPaolo Bonzini * 416c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 417c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 418c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 419c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 420c50d8ae3SPaolo Bonzini */ 421c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 422c50d8ae3SPaolo Bonzini { 42357354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 424c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 425c50d8ae3SPaolo Bonzini int count; 426c50d8ae3SPaolo Bonzini 427c50d8ae3SPaolo Bonzini retry: 428c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 429c50d8ae3SPaolo Bonzini smp_rmb(); 430c50d8ae3SPaolo Bonzini 431c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 432c50d8ae3SPaolo Bonzini smp_rmb(); 433c50d8ae3SPaolo Bonzini 434c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 435c50d8ae3SPaolo Bonzini smp_rmb(); 436c50d8ae3SPaolo Bonzini 437c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 438c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 439c50d8ae3SPaolo Bonzini goto retry; 440c50d8ae3SPaolo Bonzini 441c50d8ae3SPaolo Bonzini return spte.spte; 442c50d8ae3SPaolo Bonzini } 443c50d8ae3SPaolo Bonzini #endif 444c50d8ae3SPaolo Bonzini 445c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 446c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 447c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 448c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 449c50d8ae3SPaolo Bonzini * the spte. 450c50d8ae3SPaolo Bonzini */ 451c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 452c50d8ae3SPaolo Bonzini { 453c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 454c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 455c50d8ae3SPaolo Bonzini } 456c50d8ae3SPaolo Bonzini 457c50d8ae3SPaolo Bonzini /* 458c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 459c50d8ae3SPaolo Bonzini * accessed/dirty status. 460c50d8ae3SPaolo Bonzini */ 461c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 462c50d8ae3SPaolo Bonzini { 463c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 464c50d8ae3SPaolo Bonzini 465c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 466115111efSDavid Matlack check_spte_writable_invariants(new_spte); 467c50d8ae3SPaolo Bonzini 468c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 469c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 470c50d8ae3SPaolo Bonzini return old_spte; 471c50d8ae3SPaolo Bonzini } 472c50d8ae3SPaolo Bonzini 473c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 474c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 475c50d8ae3SPaolo Bonzini else 476c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 477c50d8ae3SPaolo Bonzini 478c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 479c50d8ae3SPaolo Bonzini 480c50d8ae3SPaolo Bonzini return old_spte; 481c50d8ae3SPaolo Bonzini } 482c50d8ae3SPaolo Bonzini 483c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 484c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 485c50d8ae3SPaolo Bonzini * 48602844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 48702844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 48802844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 489c50d8ae3SPaolo Bonzini * 490c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 491c50d8ae3SPaolo Bonzini */ 492c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 493c50d8ae3SPaolo Bonzini { 494c50d8ae3SPaolo Bonzini bool flush = false; 495c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 496c50d8ae3SPaolo Bonzini 497c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 498c50d8ae3SPaolo Bonzini return false; 499c50d8ae3SPaolo Bonzini 500c50d8ae3SPaolo Bonzini /* 501c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 502c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 503c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 504c50d8ae3SPaolo Bonzini */ 505706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 506c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 507c50d8ae3SPaolo Bonzini flush = true; 508c50d8ae3SPaolo Bonzini 509c50d8ae3SPaolo Bonzini /* 510c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 511c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 512c50d8ae3SPaolo Bonzini */ 513c50d8ae3SPaolo Bonzini 514c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 515c50d8ae3SPaolo Bonzini flush = true; 516c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 517c50d8ae3SPaolo Bonzini } 518c50d8ae3SPaolo Bonzini 519c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 520c50d8ae3SPaolo Bonzini flush = true; 521c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 522c50d8ae3SPaolo Bonzini } 523c50d8ae3SPaolo Bonzini 524c50d8ae3SPaolo Bonzini return flush; 525c50d8ae3SPaolo Bonzini } 526c50d8ae3SPaolo Bonzini 527c50d8ae3SPaolo Bonzini /* 528c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 529c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 530c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5317fa2a347SSean Christopherson * Returns the old PTE. 532c50d8ae3SPaolo Bonzini */ 53335d539c3SSean Christopherson static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 534c50d8ae3SPaolo Bonzini { 535c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 536c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 53771f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 538b14b2690SSean Christopherson struct page *page; 539c50d8ae3SPaolo Bonzini 54054eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 54154eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 542c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 543c50d8ae3SPaolo Bonzini else 544c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 545c50d8ae3SPaolo Bonzini 546c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5477fa2a347SSean Christopherson return old_spte; 548c50d8ae3SPaolo Bonzini 54971f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 55071f51d2cSMingwei Zhang 551c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 552c50d8ae3SPaolo Bonzini 553c50d8ae3SPaolo Bonzini /* 554b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 555b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 556b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 557b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 558c50d8ae3SPaolo Bonzini */ 559b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 560b14b2690SSean Christopherson WARN_ON(page && !page_count(page)); 561c50d8ae3SPaolo Bonzini 562c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 563c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 564c50d8ae3SPaolo Bonzini 565c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 566c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 567c50d8ae3SPaolo Bonzini 5687fa2a347SSean Christopherson return old_spte; 569c50d8ae3SPaolo Bonzini } 570c50d8ae3SPaolo Bonzini 571c50d8ae3SPaolo Bonzini /* 572c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 573c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 574c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 575c50d8ae3SPaolo Bonzini */ 576c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 577c50d8ae3SPaolo Bonzini { 578c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 579c50d8ae3SPaolo Bonzini } 580c50d8ae3SPaolo Bonzini 581c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 582c50d8ae3SPaolo Bonzini { 583c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 584c50d8ae3SPaolo Bonzini } 585c50d8ae3SPaolo Bonzini 586c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 587c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 588c50d8ae3SPaolo Bonzini { 589c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 590c50d8ae3SPaolo Bonzini 591c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 592c50d8ae3SPaolo Bonzini return false; 593c50d8ae3SPaolo Bonzini 594c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 595c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 596c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 597c50d8ae3SPaolo Bonzini } else { 598c50d8ae3SPaolo Bonzini /* 599c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 600c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 601c50d8ae3SPaolo Bonzini */ 602c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 603c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 604c50d8ae3SPaolo Bonzini 605c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 606c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 607c50d8ae3SPaolo Bonzini } 608c50d8ae3SPaolo Bonzini 609c50d8ae3SPaolo Bonzini return true; 610c50d8ae3SPaolo Bonzini } 611c50d8ae3SPaolo Bonzini 612c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 613c50d8ae3SPaolo Bonzini { 614c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 615c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 616c5c8c7c5SDavid Matlack } else { 617c50d8ae3SPaolo Bonzini /* 618c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 619c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 620c50d8ae3SPaolo Bonzini */ 621c50d8ae3SPaolo Bonzini local_irq_disable(); 622c50d8ae3SPaolo Bonzini 623c50d8ae3SPaolo Bonzini /* 624c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 625c50d8ae3SPaolo Bonzini * to vcpu->mode. 626c50d8ae3SPaolo Bonzini */ 627c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 628c50d8ae3SPaolo Bonzini } 629c5c8c7c5SDavid Matlack } 630c50d8ae3SPaolo Bonzini 631c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 632c50d8ae3SPaolo Bonzini { 633c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 634c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 635c5c8c7c5SDavid Matlack } else { 636c50d8ae3SPaolo Bonzini /* 637c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 638c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 639c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 640c50d8ae3SPaolo Bonzini */ 641c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 642c50d8ae3SPaolo Bonzini local_irq_enable(); 643c50d8ae3SPaolo Bonzini } 644c5c8c7c5SDavid Matlack } 645c50d8ae3SPaolo Bonzini 646378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 647c50d8ae3SPaolo Bonzini { 648c50d8ae3SPaolo Bonzini int r; 649c50d8ae3SPaolo Bonzini 650531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 65194ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 652531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 653c50d8ae3SPaolo Bonzini if (r) 654c50d8ae3SPaolo Bonzini return r; 65594ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 656171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 657171a90d7SSean Christopherson if (r) 658171a90d7SSean Christopherson return r; 659378f5cd6SSean Christopherson if (maybe_indirect) { 6606a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 661171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 662c50d8ae3SPaolo Bonzini if (r) 663c50d8ae3SPaolo Bonzini return r; 664378f5cd6SSean Christopherson } 66594ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 666531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 667c50d8ae3SPaolo Bonzini } 668c50d8ae3SPaolo Bonzini 669c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 670c50d8ae3SPaolo Bonzini { 67194ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 67294ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 6736a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 67494ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 675c50d8ae3SPaolo Bonzini } 676c50d8ae3SPaolo Bonzini 677c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 678c50d8ae3SPaolo Bonzini { 679c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 680c50d8ae3SPaolo Bonzini } 681c50d8ae3SPaolo Bonzini 6826a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 6836a97575dSDavid Matlack 684c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 685c50d8ae3SPaolo Bonzini { 68684e5ffd0SLai Jiangshan if (sp->role.passthrough) 68784e5ffd0SLai Jiangshan return sp->gfn; 68884e5ffd0SLai Jiangshan 689c50d8ae3SPaolo Bonzini if (!sp->role.direct) 6906a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 691c50d8ae3SPaolo Bonzini 6922ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 693c50d8ae3SPaolo Bonzini } 694c50d8ae3SPaolo Bonzini 6956a97575dSDavid Matlack /* 6966a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 6976a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 6986a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 6996a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 7006a97575dSDavid Matlack */ 7016a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 702c50d8ae3SPaolo Bonzini { 7036a97575dSDavid Matlack if (sp_has_gptes(sp)) 7046a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7056a97575dSDavid Matlack 7066a97575dSDavid Matlack /* 7076a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7086a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7096a97575dSDavid Matlack * permissions" are just ACC_ALL. 7106a97575dSDavid Matlack * 7116a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7126a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7136a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7146a97575dSDavid Matlack * page. 7156a97575dSDavid Matlack * 7166a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7176a97575dSDavid Matlack */ 7186a97575dSDavid Matlack return sp->role.access; 7196a97575dSDavid Matlack } 7206a97575dSDavid Matlack 72172ae5822SSean Christopherson static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, 72272ae5822SSean Christopherson gfn_t gfn, unsigned int access) 7236a97575dSDavid Matlack { 7246a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7256a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 72684e5ffd0SLai Jiangshan return; 72784e5ffd0SLai Jiangshan } 72884e5ffd0SLai Jiangshan 7296a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7306a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7316a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7326a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7336a97575dSDavid Matlack 7346a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7356a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7366a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7376a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 738c50d8ae3SPaolo Bonzini } 739c50d8ae3SPaolo Bonzini 74072ae5822SSean Christopherson static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, 74172ae5822SSean Christopherson unsigned int access) 7426a97575dSDavid Matlack { 7436a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7446a97575dSDavid Matlack 7456a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 746c50d8ae3SPaolo Bonzini } 747c50d8ae3SPaolo Bonzini 748c50d8ae3SPaolo Bonzini /* 749c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 750c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 751c50d8ae3SPaolo Bonzini */ 752c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7538ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 754c50d8ae3SPaolo Bonzini { 755c50d8ae3SPaolo Bonzini unsigned long idx; 756c50d8ae3SPaolo Bonzini 757c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 758c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 759c50d8ae3SPaolo Bonzini } 760c50d8ae3SPaolo Bonzini 761269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 762c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 763c50d8ae3SPaolo Bonzini { 764c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 765c50d8ae3SPaolo Bonzini int i; 766c50d8ae3SPaolo Bonzini 7673bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 768c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 769c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 770c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 771c50d8ae3SPaolo Bonzini } 772c50d8ae3SPaolo Bonzini } 773c50d8ae3SPaolo Bonzini 774269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 775c50d8ae3SPaolo Bonzini { 776c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 777c50d8ae3SPaolo Bonzini } 778c50d8ae3SPaolo Bonzini 779269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 780c50d8ae3SPaolo Bonzini { 781c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 782c50d8ae3SPaolo Bonzini } 783c50d8ae3SPaolo Bonzini 784c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 785c50d8ae3SPaolo Bonzini { 786c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 787c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 788c50d8ae3SPaolo Bonzini gfn_t gfn; 789c50d8ae3SPaolo Bonzini 790c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 791c50d8ae3SPaolo Bonzini gfn = sp->gfn; 792c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 793c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 794c50d8ae3SPaolo Bonzini 795c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 7963bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 797c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 798c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 799c50d8ae3SPaolo Bonzini 800c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 801be911771SDavid Matlack 802be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 803be911771SDavid Matlack kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 804c50d8ae3SPaolo Bonzini } 805c50d8ae3SPaolo Bonzini 80629cf0f50SBen Gardon void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 807c50d8ae3SPaolo Bonzini { 808c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 809c50d8ae3SPaolo Bonzini return; 810c50d8ae3SPaolo Bonzini 811c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 812c50d8ae3SPaolo Bonzini list_add_tail(&sp->lpage_disallowed_link, 813c50d8ae3SPaolo Bonzini &kvm->arch.lpage_disallowed_mmu_pages); 814c50d8ae3SPaolo Bonzini sp->lpage_disallowed = true; 815c50d8ae3SPaolo Bonzini } 816c50d8ae3SPaolo Bonzini 817c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 818c50d8ae3SPaolo Bonzini { 819c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 820c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 821c50d8ae3SPaolo Bonzini gfn_t gfn; 822c50d8ae3SPaolo Bonzini 823c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 824c50d8ae3SPaolo Bonzini gfn = sp->gfn; 825c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 826c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8273bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 828c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 829c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 830c50d8ae3SPaolo Bonzini 831c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 832c50d8ae3SPaolo Bonzini } 833c50d8ae3SPaolo Bonzini 83429cf0f50SBen Gardon void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp) 835c50d8ae3SPaolo Bonzini { 836c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 837c50d8ae3SPaolo Bonzini sp->lpage_disallowed = false; 838c50d8ae3SPaolo Bonzini list_del(&sp->lpage_disallowed_link); 839c50d8ae3SPaolo Bonzini } 840c50d8ae3SPaolo Bonzini 841c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 842c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 843c50d8ae3SPaolo Bonzini bool no_dirty_log) 844c50d8ae3SPaolo Bonzini { 845c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 846c50d8ae3SPaolo Bonzini 847c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 84891b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 84991b0d268SPaolo Bonzini return NULL; 850044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 85191b0d268SPaolo Bonzini return NULL; 852c50d8ae3SPaolo Bonzini 853c50d8ae3SPaolo Bonzini return slot; 854c50d8ae3SPaolo Bonzini } 855c50d8ae3SPaolo Bonzini 856c50d8ae3SPaolo Bonzini /* 857c50d8ae3SPaolo Bonzini * About rmap_head encoding: 858c50d8ae3SPaolo Bonzini * 859c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 860c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 861c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 862c50d8ae3SPaolo Bonzini */ 863c50d8ae3SPaolo Bonzini 864c50d8ae3SPaolo Bonzini /* 865c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 866c50d8ae3SPaolo Bonzini */ 8672ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 868c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 869c50d8ae3SPaolo Bonzini { 870c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 87113236e25SPeter Xu int count = 0; 872c50d8ae3SPaolo Bonzini 873c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 874805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 875c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 876c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 877805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 8782ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 879c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 880c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 88113236e25SPeter Xu desc->spte_count = 2; 882c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 883c50d8ae3SPaolo Bonzini ++count; 884c50d8ae3SPaolo Bonzini } else { 885805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 886c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 88713236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 888c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 889c6c4f961SLi RongQing if (!desc->more) { 8902ff9039aSDavid Matlack desc->more = kvm_mmu_memory_cache_alloc(cache); 891c50d8ae3SPaolo Bonzini desc = desc->more; 89213236e25SPeter Xu desc->spte_count = 0; 893c6c4f961SLi RongQing break; 894c6c4f961SLi RongQing } 895c6c4f961SLi RongQing desc = desc->more; 896c50d8ae3SPaolo Bonzini } 89713236e25SPeter Xu count += desc->spte_count; 89813236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 899c50d8ae3SPaolo Bonzini } 900c50d8ae3SPaolo Bonzini return count; 901c50d8ae3SPaolo Bonzini } 902c50d8ae3SPaolo Bonzini 903c50d8ae3SPaolo Bonzini static void 904c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 905c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 906c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 907c50d8ae3SPaolo Bonzini { 90813236e25SPeter Xu int j = desc->spte_count - 1; 909c50d8ae3SPaolo Bonzini 910c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 911c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 91213236e25SPeter Xu desc->spte_count--; 91313236e25SPeter Xu if (desc->spte_count) 914c50d8ae3SPaolo Bonzini return; 915c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 916fe3c2b4cSMiaohe Lin rmap_head->val = 0; 917c50d8ae3SPaolo Bonzini else 918c50d8ae3SPaolo Bonzini if (prev_desc) 919c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 920c50d8ae3SPaolo Bonzini else 921c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 922c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 923c50d8ae3SPaolo Bonzini } 924c50d8ae3SPaolo Bonzini 9253c2e1037SSean Christopherson static void pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 926c50d8ae3SPaolo Bonzini { 927c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 928c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 929c50d8ae3SPaolo Bonzini int i; 930c50d8ae3SPaolo Bonzini 931c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 932c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 933c50d8ae3SPaolo Bonzini BUG(); 934c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 935805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 936c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 937c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 938c50d8ae3SPaolo Bonzini BUG(); 939c50d8ae3SPaolo Bonzini } 940c50d8ae3SPaolo Bonzini rmap_head->val = 0; 941c50d8ae3SPaolo Bonzini } else { 942805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 943c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 944c50d8ae3SPaolo Bonzini prev_desc = NULL; 945c50d8ae3SPaolo Bonzini while (desc) { 94613236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 947c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 948c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 949c50d8ae3SPaolo Bonzini desc, i, prev_desc); 950c50d8ae3SPaolo Bonzini return; 951c50d8ae3SPaolo Bonzini } 952c50d8ae3SPaolo Bonzini } 953c50d8ae3SPaolo Bonzini prev_desc = desc; 954c50d8ae3SPaolo Bonzini desc = desc->more; 955c50d8ae3SPaolo Bonzini } 956c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 957c50d8ae3SPaolo Bonzini BUG(); 958c50d8ae3SPaolo Bonzini } 959c50d8ae3SPaolo Bonzini } 960c50d8ae3SPaolo Bonzini 9619202aee8SSean Christopherson static void kvm_zap_one_rmap_spte(struct kvm *kvm, 9629202aee8SSean Christopherson struct kvm_rmap_head *rmap_head, u64 *sptep) 963c50d8ae3SPaolo Bonzini { 96471f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 9653c2e1037SSean Christopherson pte_list_remove(sptep, rmap_head); 966c50d8ae3SPaolo Bonzini } 967c50d8ae3SPaolo Bonzini 9689202aee8SSean Christopherson /* Return true if at least one SPTE was zapped, false otherwise */ 9699202aee8SSean Christopherson static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 9709202aee8SSean Christopherson struct kvm_rmap_head *rmap_head) 971a75b5404SPeter Xu { 972a75b5404SPeter Xu struct pte_list_desc *desc, *next; 973a75b5404SPeter Xu int i; 974a75b5404SPeter Xu 975a75b5404SPeter Xu if (!rmap_head->val) 976a75b5404SPeter Xu return false; 977a75b5404SPeter Xu 978a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 97971f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 980a75b5404SPeter Xu goto out; 981a75b5404SPeter Xu } 982a75b5404SPeter Xu 983a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 984a75b5404SPeter Xu 985a75b5404SPeter Xu for (; desc; desc = next) { 986a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 98771f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 988a75b5404SPeter Xu next = desc->more; 989a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 990a75b5404SPeter Xu } 991a75b5404SPeter Xu out: 992a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 993a75b5404SPeter Xu rmap_head->val = 0; 994a75b5404SPeter Xu return true; 995a75b5404SPeter Xu } 996a75b5404SPeter Xu 9973bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 9983bcd0662SPeter Xu { 9993bcd0662SPeter Xu struct pte_list_desc *desc; 10003bcd0662SPeter Xu unsigned int count = 0; 10013bcd0662SPeter Xu 10023bcd0662SPeter Xu if (!rmap_head->val) 10033bcd0662SPeter Xu return 0; 10043bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10053bcd0662SPeter Xu return 1; 10063bcd0662SPeter Xu 10073bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10083bcd0662SPeter Xu 10093bcd0662SPeter Xu while (desc) { 10103bcd0662SPeter Xu count += desc->spte_count; 10113bcd0662SPeter Xu desc = desc->more; 10123bcd0662SPeter Xu } 10133bcd0662SPeter Xu 10143bcd0662SPeter Xu return count; 10153bcd0662SPeter Xu } 10163bcd0662SPeter Xu 101793e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1018269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1019c50d8ae3SPaolo Bonzini { 1020c50d8ae3SPaolo Bonzini unsigned long idx; 1021c50d8ae3SPaolo Bonzini 1022c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10233bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1024c50d8ae3SPaolo Bonzini } 1025c50d8ae3SPaolo Bonzini 1026c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1027c50d8ae3SPaolo Bonzini { 1028356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1029c50d8ae3SPaolo Bonzini 1030356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 103194ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1032c50d8ae3SPaolo Bonzini } 1033c50d8ae3SPaolo Bonzini 1034c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1035c50d8ae3SPaolo Bonzini { 1036601f8af0SDavid Matlack struct kvm_memslots *slots; 1037601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1038c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1039c50d8ae3SPaolo Bonzini gfn_t gfn; 1040c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1041c50d8ae3SPaolo Bonzini 104257354682SSean Christopherson sp = sptep_to_sp(spte); 104379e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(spte)); 1044601f8af0SDavid Matlack 1045601f8af0SDavid Matlack /* 104668be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 104768be1306SDavid Matlack * so we have to determine which memslots to use based on context 104868be1306SDavid Matlack * information in sp->role. 1049601f8af0SDavid Matlack */ 1050601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1051601f8af0SDavid Matlack 1052601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 105393e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1054601f8af0SDavid Matlack 10553c2e1037SSean Christopherson pte_list_remove(spte, rmap_head); 1056c50d8ae3SPaolo Bonzini } 1057c50d8ae3SPaolo Bonzini 1058c50d8ae3SPaolo Bonzini /* 1059c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1060c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1061c50d8ae3SPaolo Bonzini */ 1062c50d8ae3SPaolo Bonzini struct rmap_iterator { 1063c50d8ae3SPaolo Bonzini /* private fields */ 1064c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1065c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1066c50d8ae3SPaolo Bonzini }; 1067c50d8ae3SPaolo Bonzini 1068c50d8ae3SPaolo Bonzini /* 1069c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1070c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 10710a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1072c50d8ae3SPaolo Bonzini * 1073c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1074c50d8ae3SPaolo Bonzini */ 1075c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1076c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1077c50d8ae3SPaolo Bonzini { 1078c50d8ae3SPaolo Bonzini u64 *sptep; 1079c50d8ae3SPaolo Bonzini 1080c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1081c50d8ae3SPaolo Bonzini return NULL; 1082c50d8ae3SPaolo Bonzini 1083c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1084c50d8ae3SPaolo Bonzini iter->desc = NULL; 1085c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1086c50d8ae3SPaolo Bonzini goto out; 1087c50d8ae3SPaolo Bonzini } 1088c50d8ae3SPaolo Bonzini 1089c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1090c50d8ae3SPaolo Bonzini iter->pos = 0; 1091c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1092c50d8ae3SPaolo Bonzini out: 1093c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1094c50d8ae3SPaolo Bonzini return sptep; 1095c50d8ae3SPaolo Bonzini } 1096c50d8ae3SPaolo Bonzini 1097c50d8ae3SPaolo Bonzini /* 1098c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1099c50d8ae3SPaolo Bonzini * 1100c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1101c50d8ae3SPaolo Bonzini */ 1102c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1103c50d8ae3SPaolo Bonzini { 1104c50d8ae3SPaolo Bonzini u64 *sptep; 1105c50d8ae3SPaolo Bonzini 1106c50d8ae3SPaolo Bonzini if (iter->desc) { 1107c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1108c50d8ae3SPaolo Bonzini ++iter->pos; 1109c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1110c50d8ae3SPaolo Bonzini if (sptep) 1111c50d8ae3SPaolo Bonzini goto out; 1112c50d8ae3SPaolo Bonzini } 1113c50d8ae3SPaolo Bonzini 1114c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1115c50d8ae3SPaolo Bonzini 1116c50d8ae3SPaolo Bonzini if (iter->desc) { 1117c50d8ae3SPaolo Bonzini iter->pos = 0; 1118c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1119c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1120c50d8ae3SPaolo Bonzini goto out; 1121c50d8ae3SPaolo Bonzini } 1122c50d8ae3SPaolo Bonzini } 1123c50d8ae3SPaolo Bonzini 1124c50d8ae3SPaolo Bonzini return NULL; 1125c50d8ae3SPaolo Bonzini out: 1126c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1127c50d8ae3SPaolo Bonzini return sptep; 1128c50d8ae3SPaolo Bonzini } 1129c50d8ae3SPaolo Bonzini 1130c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1131c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1132c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1133c50d8ae3SPaolo Bonzini 1134c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1135c50d8ae3SPaolo Bonzini { 113671f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11377fa2a347SSean Christopherson 11387fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1139c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1140c50d8ae3SPaolo Bonzini } 1141c50d8ae3SPaolo Bonzini 114203787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1143c50d8ae3SPaolo Bonzini { 11440cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 11450cd8dc73SPaolo Bonzini 11460cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 11470cd8dc73SPaolo Bonzini WARN_ON(sp->role.level == PG_LEVEL_4K); 11480cd8dc73SPaolo Bonzini 1149c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 115003787394SPaolo Bonzini 115103787394SPaolo Bonzini if (flush) 11520cd8dc73SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 1153c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1154c50d8ae3SPaolo Bonzini } 1155c50d8ae3SPaolo Bonzini 1156c50d8ae3SPaolo Bonzini /* 1157c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1158c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1159c50d8ae3SPaolo Bonzini * 1160c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1161c50d8ae3SPaolo Bonzini * protection: 1162c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1163c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1164c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1165c50d8ae3SPaolo Bonzini * shadow page. 1166c50d8ae3SPaolo Bonzini * 1167c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1168c50d8ae3SPaolo Bonzini */ 1169c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1170c50d8ae3SPaolo Bonzini { 1171c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1172c50d8ae3SPaolo Bonzini 1173c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1174706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1175c50d8ae3SPaolo Bonzini return false; 1176c50d8ae3SPaolo Bonzini 1177805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1178c50d8ae3SPaolo Bonzini 1179c50d8ae3SPaolo Bonzini if (pt_protect) 11805fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1181c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1182c50d8ae3SPaolo Bonzini 1183c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1184c50d8ae3SPaolo Bonzini } 1185c50d8ae3SPaolo Bonzini 11861346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1187c50d8ae3SPaolo Bonzini bool pt_protect) 1188c50d8ae3SPaolo Bonzini { 1189c50d8ae3SPaolo Bonzini u64 *sptep; 1190c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1191c50d8ae3SPaolo Bonzini bool flush = false; 1192c50d8ae3SPaolo Bonzini 1193c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1194c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1195c50d8ae3SPaolo Bonzini 1196c50d8ae3SPaolo Bonzini return flush; 1197c50d8ae3SPaolo Bonzini } 1198c50d8ae3SPaolo Bonzini 1199c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1200c50d8ae3SPaolo Bonzini { 1201c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1202c50d8ae3SPaolo Bonzini 1203805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1204c50d8ae3SPaolo Bonzini 1205c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1206c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1207c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1208c50d8ae3SPaolo Bonzini } 1209c50d8ae3SPaolo Bonzini 1210c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1211c50d8ae3SPaolo Bonzini { 1212c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1213c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1214c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1215c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1216c50d8ae3SPaolo Bonzini 1217c50d8ae3SPaolo Bonzini return was_writable; 1218c50d8ae3SPaolo Bonzini } 1219c50d8ae3SPaolo Bonzini 1220c50d8ae3SPaolo Bonzini /* 1221c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1222c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1223c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1224c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1225c50d8ae3SPaolo Bonzini */ 12260a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1227269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1228c50d8ae3SPaolo Bonzini { 1229c50d8ae3SPaolo Bonzini u64 *sptep; 1230c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1231c50d8ae3SPaolo Bonzini bool flush = false; 1232c50d8ae3SPaolo Bonzini 1233c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1234c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1235c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1236c50d8ae3SPaolo Bonzini else 1237c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1238c50d8ae3SPaolo Bonzini 1239c50d8ae3SPaolo Bonzini return flush; 1240c50d8ae3SPaolo Bonzini } 1241c50d8ae3SPaolo Bonzini 1242c50d8ae3SPaolo Bonzini /** 1243c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1244c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1245c50d8ae3SPaolo Bonzini * @slot: slot to protect 1246c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1247c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1248c50d8ae3SPaolo Bonzini * 124989212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1250c50d8ae3SPaolo Bonzini */ 1251c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1252c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1253c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1254c50d8ae3SPaolo Bonzini { 1255c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1256c50d8ae3SPaolo Bonzini 1257897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1258a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1259a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1260e2209710SBen Gardon 1261e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1262e2209710SBen Gardon return; 1263e2209710SBen Gardon 1264c50d8ae3SPaolo Bonzini while (mask) { 126593e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12663bae0459SSean Christopherson PG_LEVEL_4K, slot); 12671346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1268c50d8ae3SPaolo Bonzini 1269c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1270c50d8ae3SPaolo Bonzini mask &= mask - 1; 1271c50d8ae3SPaolo Bonzini } 1272c50d8ae3SPaolo Bonzini } 1273c50d8ae3SPaolo Bonzini 1274c50d8ae3SPaolo Bonzini /** 1275c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1276c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1277c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1278c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1279c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1280c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1281c50d8ae3SPaolo Bonzini * 1282c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1283c50d8ae3SPaolo Bonzini */ 1284a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1285c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1286c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1287c50d8ae3SPaolo Bonzini { 1288c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1289c50d8ae3SPaolo Bonzini 1290897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1291a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1292a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1293e2209710SBen Gardon 1294e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1295e2209710SBen Gardon return; 1296e2209710SBen Gardon 1297c50d8ae3SPaolo Bonzini while (mask) { 129893e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12993bae0459SSean Christopherson PG_LEVEL_4K, slot); 13000a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1301c50d8ae3SPaolo Bonzini 1302c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1303c50d8ae3SPaolo Bonzini mask &= mask - 1; 1304c50d8ae3SPaolo Bonzini } 1305c50d8ae3SPaolo Bonzini } 1306c50d8ae3SPaolo Bonzini 1307c50d8ae3SPaolo Bonzini /** 1308c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1309c50d8ae3SPaolo Bonzini * PT level pages. 1310c50d8ae3SPaolo Bonzini * 1311c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1312c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1313c50d8ae3SPaolo Bonzini * 131489212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 131589212919SKeqian Zhu * have such mappings. 1316c50d8ae3SPaolo Bonzini */ 1317c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1318c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1319c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1320c50d8ae3SPaolo Bonzini { 132189212919SKeqian Zhu /* 132289212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 132389212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 132489212919SKeqian Zhu * are split to 4K on the first write. 132589212919SKeqian Zhu * 132689212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 132789212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 132889212919SKeqian Zhu * pages. 132989212919SKeqian Zhu */ 133089212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 133189212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 133289212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 133389212919SKeqian Zhu 1334cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1335cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1336cb00a70bSDavid Matlack 133789212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 133889212919SKeqian Zhu 133989212919SKeqian Zhu /* Cross two large pages? */ 134089212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 134189212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 134289212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 134389212919SKeqian Zhu PG_LEVEL_2M); 134489212919SKeqian Zhu } 134589212919SKeqian Zhu 134689212919SKeqian Zhu /* Now handle 4K PTEs. */ 1347a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1348a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1349c50d8ae3SPaolo Bonzini else 1350c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1351c50d8ae3SPaolo Bonzini } 1352c50d8ae3SPaolo Bonzini 1353fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1354fb04a1edSPeter Xu { 13556dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1356fb04a1edSPeter Xu } 1357fb04a1edSPeter Xu 1358c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13593ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13603ad93562SKeqian Zhu int min_level) 1361c50d8ae3SPaolo Bonzini { 1362c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1363c50d8ae3SPaolo Bonzini int i; 1364c50d8ae3SPaolo Bonzini bool write_protected = false; 1365c50d8ae3SPaolo Bonzini 1366e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13673ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 136893e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 13691346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1370c50d8ae3SPaolo Bonzini } 1371e2209710SBen Gardon } 1372c50d8ae3SPaolo Bonzini 1373897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 137446044f72SBen Gardon write_protected |= 13753ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 137646044f72SBen Gardon 1377c50d8ae3SPaolo Bonzini return write_protected; 1378c50d8ae3SPaolo Bonzini } 1379c50d8ae3SPaolo Bonzini 1380cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1381c50d8ae3SPaolo Bonzini { 1382c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1383c50d8ae3SPaolo Bonzini 1384c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 13853ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1386c50d8ae3SPaolo Bonzini } 1387c50d8ae3SPaolo Bonzini 1388f8480721SSean Christopherson static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1389269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1390c50d8ae3SPaolo Bonzini { 13919202aee8SSean Christopherson return kvm_zap_all_rmap_sptes(kvm, rmap_head); 1392c50d8ae3SPaolo Bonzini } 1393c50d8ae3SPaolo Bonzini 1394f8480721SSean Christopherson static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1395c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 13963039bcc7SSean Christopherson pte_t unused) 1397c50d8ae3SPaolo Bonzini { 1398f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1399c50d8ae3SPaolo Bonzini } 1400c50d8ae3SPaolo Bonzini 1401aed02fe3SSean Christopherson static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1402c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14033039bcc7SSean Christopherson pte_t pte) 1404c50d8ae3SPaolo Bonzini { 1405c50d8ae3SPaolo Bonzini u64 *sptep; 1406c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 140798a26b69SVihas Mak bool need_flush = false; 1408c50d8ae3SPaolo Bonzini u64 new_spte; 1409c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1410c50d8ae3SPaolo Bonzini 14113039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14123039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1413c50d8ae3SPaolo Bonzini 1414c50d8ae3SPaolo Bonzini restart: 1415c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1416805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1417c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1418c50d8ae3SPaolo Bonzini 141998a26b69SVihas Mak need_flush = true; 1420c50d8ae3SPaolo Bonzini 14213039bcc7SSean Christopherson if (pte_write(pte)) { 14229202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 1423c50d8ae3SPaolo Bonzini goto restart; 1424c50d8ae3SPaolo Bonzini } else { 1425cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1426cb3eedabSPaolo Bonzini *sptep, new_pfn); 1427c50d8ae3SPaolo Bonzini 142871f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1429c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1430c50d8ae3SPaolo Bonzini } 1431c50d8ae3SPaolo Bonzini } 1432c50d8ae3SPaolo Bonzini 1433c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1434c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 143598a26b69SVihas Mak return false; 1436c50d8ae3SPaolo Bonzini } 1437c50d8ae3SPaolo Bonzini 1438c50d8ae3SPaolo Bonzini return need_flush; 1439c50d8ae3SPaolo Bonzini } 1440c50d8ae3SPaolo Bonzini 1441c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1442c50d8ae3SPaolo Bonzini /* input fields. */ 1443269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1444c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1445c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1446c50d8ae3SPaolo Bonzini int start_level; 1447c50d8ae3SPaolo Bonzini int end_level; 1448c50d8ae3SPaolo Bonzini 1449c50d8ae3SPaolo Bonzini /* output fields. */ 1450c50d8ae3SPaolo Bonzini gfn_t gfn; 1451c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1452c50d8ae3SPaolo Bonzini int level; 1453c50d8ae3SPaolo Bonzini 1454c50d8ae3SPaolo Bonzini /* private field. */ 1455c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1456c50d8ae3SPaolo Bonzini }; 1457c50d8ae3SPaolo Bonzini 1458c50d8ae3SPaolo Bonzini static void 1459c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1460c50d8ae3SPaolo Bonzini { 1461c50d8ae3SPaolo Bonzini iterator->level = level; 1462c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 146393e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 146493e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1465c50d8ae3SPaolo Bonzini } 1466c50d8ae3SPaolo Bonzini 1467c50d8ae3SPaolo Bonzini static void 1468c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1469269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1470c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1471c50d8ae3SPaolo Bonzini { 1472c50d8ae3SPaolo Bonzini iterator->slot = slot; 1473c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1474c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1475c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1476c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1477c50d8ae3SPaolo Bonzini 1478c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1479c50d8ae3SPaolo Bonzini } 1480c50d8ae3SPaolo Bonzini 1481c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1482c50d8ae3SPaolo Bonzini { 1483c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1484c50d8ae3SPaolo Bonzini } 1485c50d8ae3SPaolo Bonzini 1486c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1487c50d8ae3SPaolo Bonzini { 14886ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1489c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 14906ba1e04fSVipin Sharma 14916ba1e04fSVipin Sharma if (iterator->rmap->val) 1492c50d8ae3SPaolo Bonzini return; 1493c50d8ae3SPaolo Bonzini } 1494c50d8ae3SPaolo Bonzini 1495c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1496c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1497c50d8ae3SPaolo Bonzini return; 1498c50d8ae3SPaolo Bonzini } 1499c50d8ae3SPaolo Bonzini 1500c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1501c50d8ae3SPaolo Bonzini } 1502c50d8ae3SPaolo Bonzini 1503c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1504c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1505c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1506c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1507c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1508c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1509c50d8ae3SPaolo Bonzini 15103039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1511c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15123039bcc7SSean Christopherson int level, pte_t pte); 1513c1b91493SSean Christopherson 15143039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15153039bcc7SSean Christopherson struct kvm_gfn_range *range, 1516c1b91493SSean Christopherson rmap_handler_t handler) 1517c50d8ae3SPaolo Bonzini { 1518c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15193039bcc7SSean Christopherson bool ret = false; 1520c50d8ae3SPaolo Bonzini 15213039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15223039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15233039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15243039bcc7SSean Christopherson iterator.level, range->pte); 1525c50d8ae3SPaolo Bonzini 1526c50d8ae3SPaolo Bonzini return ret; 1527c50d8ae3SPaolo Bonzini } 1528c50d8ae3SPaolo Bonzini 15293039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1530c50d8ae3SPaolo Bonzini { 1531e2209710SBen Gardon bool flush = false; 1532c50d8ae3SPaolo Bonzini 1533e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1534f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1535063afacdSBen Gardon 1536897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 1537c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1538063afacdSBen Gardon 15393039bcc7SSean Christopherson return flush; 1540c50d8ae3SPaolo Bonzini } 1541c50d8ae3SPaolo Bonzini 15423039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1543c50d8ae3SPaolo Bonzini { 1544e2209710SBen Gardon bool flush = false; 15451d8dd6b3SBen Gardon 1546e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1547aed02fe3SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); 15481d8dd6b3SBen Gardon 1549897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 15503039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15511d8dd6b3SBen Gardon 15523039bcc7SSean Christopherson return flush; 1553c50d8ae3SPaolo Bonzini } 1554c50d8ae3SPaolo Bonzini 1555aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1556c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15573039bcc7SSean Christopherson pte_t unused) 1558c50d8ae3SPaolo Bonzini { 1559c50d8ae3SPaolo Bonzini u64 *sptep; 15603f649ab7SKees Cook struct rmap_iterator iter; 1561c50d8ae3SPaolo Bonzini int young = 0; 1562c50d8ae3SPaolo Bonzini 1563c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1564c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1565c50d8ae3SPaolo Bonzini 1566c50d8ae3SPaolo Bonzini return young; 1567c50d8ae3SPaolo Bonzini } 1568c50d8ae3SPaolo Bonzini 1569aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1570c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 15713039bcc7SSean Christopherson int level, pte_t unused) 1572c50d8ae3SPaolo Bonzini { 1573c50d8ae3SPaolo Bonzini u64 *sptep; 1574c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1575c50d8ae3SPaolo Bonzini 1576c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1577c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 157898a26b69SVihas Mak return true; 157998a26b69SVihas Mak return false; 1580c50d8ae3SPaolo Bonzini } 1581c50d8ae3SPaolo Bonzini 1582c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1583c50d8ae3SPaolo Bonzini 15842ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 15852ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 15862ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 158772ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1588c50d8ae3SPaolo Bonzini { 1589c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 159068be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 159168be1306SDavid Matlack int rmap_count; 1592c50d8ae3SPaolo Bonzini 159357354682SSean Christopherson sp = sptep_to_sp(spte); 159479e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 159581cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 159681cb4657SDavid Matlack 159793e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 15982ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1599c50d8ae3SPaolo Bonzini 1600604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1601604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 160268be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16039202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 160468be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 16052ff9039aSDavid Matlack kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 160668be1306SDavid Matlack } 1607c50d8ae3SPaolo Bonzini } 1608c50d8ae3SPaolo Bonzini 16092ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 161072ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16112ff9039aSDavid Matlack { 16122ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16132ff9039aSDavid Matlack 16146a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16152ff9039aSDavid Matlack } 16162ff9039aSDavid Matlack 16173039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1618c50d8ae3SPaolo Bonzini { 1619e2209710SBen Gardon bool young = false; 1620f8e14497SBen Gardon 1621e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1622aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16233039bcc7SSean Christopherson 1624897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16253039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1626f8e14497SBen Gardon 1627f8e14497SBen Gardon return young; 1628c50d8ae3SPaolo Bonzini } 1629c50d8ae3SPaolo Bonzini 16303039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1631c50d8ae3SPaolo Bonzini { 1632e2209710SBen Gardon bool young = false; 1633f8e14497SBen Gardon 1634e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1635aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 16363039bcc7SSean Christopherson 1637897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 16383039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1639f8e14497SBen Gardon 1640f8e14497SBen Gardon return young; 1641c50d8ae3SPaolo Bonzini } 1642c50d8ae3SPaolo Bonzini 1643c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1644c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1645c50d8ae3SPaolo Bonzini { 1646c50d8ae3SPaolo Bonzini u64 *pos; 1647c50d8ae3SPaolo Bonzini u64 *end; 1648c50d8ae3SPaolo Bonzini 16493adbdf81SMiaohe Lin for (pos = spt, end = pos + SPTE_ENT_PER_PAGE; pos != end; pos++) 1650c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1651c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1652c50d8ae3SPaolo Bonzini pos, *pos); 1653c50d8ae3SPaolo Bonzini return 0; 1654c50d8ae3SPaolo Bonzini } 1655c50d8ae3SPaolo Bonzini return 1; 1656c50d8ae3SPaolo Bonzini } 1657c50d8ae3SPaolo Bonzini #endif 1658c50d8ae3SPaolo Bonzini 1659c50d8ae3SPaolo Bonzini /* 1660c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1661c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1662c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1663c50d8ae3SPaolo Bonzini * faster 1664c50d8ae3SPaolo Bonzini */ 1665d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1666c50d8ae3SPaolo Bonzini { 1667c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1668c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1669c50d8ae3SPaolo Bonzini } 1670c50d8ae3SPaolo Bonzini 167143a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 167243a063caSYosry Ahmed { 167343a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 167443a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 167543a063caSYosry Ahmed } 167643a063caSYosry Ahmed 167743a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 167843a063caSYosry Ahmed { 167943a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 168043a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 168143a063caSYosry Ahmed } 168243a063caSYosry Ahmed 168387654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1684c50d8ae3SPaolo Bonzini { 1685c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1686c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1687c50d8ae3SPaolo Bonzini list_del(&sp->link); 1688c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1689c50d8ae3SPaolo Bonzini if (!sp->role.direct) 16906a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1691c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1692c50d8ae3SPaolo Bonzini } 1693c50d8ae3SPaolo Bonzini 1694c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1695c50d8ae3SPaolo Bonzini { 1696c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1697c50d8ae3SPaolo Bonzini } 1698c50d8ae3SPaolo Bonzini 16992ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1700c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1701c50d8ae3SPaolo Bonzini { 1702c50d8ae3SPaolo Bonzini if (!parent_pte) 1703c50d8ae3SPaolo Bonzini return; 1704c50d8ae3SPaolo Bonzini 17052ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1706c50d8ae3SPaolo Bonzini } 1707c50d8ae3SPaolo Bonzini 1708c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1709c50d8ae3SPaolo Bonzini u64 *parent_pte) 1710c50d8ae3SPaolo Bonzini { 17113c2e1037SSean Christopherson pte_list_remove(parent_pte, &sp->parent_ptes); 1712c50d8ae3SPaolo Bonzini } 1713c50d8ae3SPaolo Bonzini 1714c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1715c50d8ae3SPaolo Bonzini u64 *parent_pte) 1716c50d8ae3SPaolo Bonzini { 1717c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1718c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1719c50d8ae3SPaolo Bonzini } 1720c50d8ae3SPaolo Bonzini 1721c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1722c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1723c50d8ae3SPaolo Bonzini { 1724c50d8ae3SPaolo Bonzini u64 *sptep; 1725c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1726c50d8ae3SPaolo Bonzini 1727c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1728c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1729c50d8ae3SPaolo Bonzini } 1730c50d8ae3SPaolo Bonzini } 1731c50d8ae3SPaolo Bonzini 1732c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1733c50d8ae3SPaolo Bonzini { 1734c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1735c50d8ae3SPaolo Bonzini 173657354682SSean Christopherson sp = sptep_to_sp(spte); 173779e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1738c50d8ae3SPaolo Bonzini return; 1739c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1740c50d8ae3SPaolo Bonzini return; 1741c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1742c50d8ae3SPaolo Bonzini } 1743c50d8ae3SPaolo Bonzini 1744c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1745c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1746c50d8ae3SPaolo Bonzini { 1747c3e5e415SLai Jiangshan return -1; 1748c50d8ae3SPaolo Bonzini } 1749c50d8ae3SPaolo Bonzini 1750c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1751c50d8ae3SPaolo Bonzini 1752c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1753c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1754c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1755c50d8ae3SPaolo Bonzini unsigned int idx; 1756c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1757c50d8ae3SPaolo Bonzini unsigned int nr; 1758c50d8ae3SPaolo Bonzini }; 1759c50d8ae3SPaolo Bonzini 1760c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1761c50d8ae3SPaolo Bonzini int idx) 1762c50d8ae3SPaolo Bonzini { 1763c50d8ae3SPaolo Bonzini int i; 1764c50d8ae3SPaolo Bonzini 1765c50d8ae3SPaolo Bonzini if (sp->unsync) 1766c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1767c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1768c50d8ae3SPaolo Bonzini return 0; 1769c50d8ae3SPaolo Bonzini 1770c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1771c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1772c50d8ae3SPaolo Bonzini pvec->nr++; 1773c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1774c50d8ae3SPaolo Bonzini } 1775c50d8ae3SPaolo Bonzini 1776c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1777c50d8ae3SPaolo Bonzini { 1778c50d8ae3SPaolo Bonzini --sp->unsync_children; 1779c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1780c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1781c50d8ae3SPaolo Bonzini } 1782c50d8ae3SPaolo Bonzini 1783c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1784c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1785c50d8ae3SPaolo Bonzini { 1786c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1787c50d8ae3SPaolo Bonzini 1788c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1789c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1790c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1791c50d8ae3SPaolo Bonzini 1792c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1793c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1794c50d8ae3SPaolo Bonzini continue; 1795c50d8ae3SPaolo Bonzini } 1796c50d8ae3SPaolo Bonzini 17972ca3129eSSean Christopherson child = to_shadow_page(ent & SPTE_BASE_ADDR_MASK); 1798c50d8ae3SPaolo Bonzini 1799c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1800c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1801c50d8ae3SPaolo Bonzini return -ENOSPC; 1802c50d8ae3SPaolo Bonzini 1803c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1804c50d8ae3SPaolo Bonzini if (!ret) { 1805c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1806c50d8ae3SPaolo Bonzini continue; 1807c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1808c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1809c50d8ae3SPaolo Bonzini } else 1810c50d8ae3SPaolo Bonzini return ret; 1811c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1812c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1813c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1814c50d8ae3SPaolo Bonzini return -ENOSPC; 1815c50d8ae3SPaolo Bonzini } else 1816c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1817c50d8ae3SPaolo Bonzini } 1818c50d8ae3SPaolo Bonzini 1819c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1820c50d8ae3SPaolo Bonzini } 1821c50d8ae3SPaolo Bonzini 1822c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1823c50d8ae3SPaolo Bonzini 1824c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1825c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1826c50d8ae3SPaolo Bonzini { 1827c50d8ae3SPaolo Bonzini pvec->nr = 0; 1828c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1829c50d8ae3SPaolo Bonzini return 0; 1830c50d8ae3SPaolo Bonzini 1831c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1832c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1833c50d8ae3SPaolo Bonzini } 1834c50d8ae3SPaolo Bonzini 1835c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1836c50d8ae3SPaolo Bonzini { 1837c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1838c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1839c50d8ae3SPaolo Bonzini sp->unsync = 0; 1840c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1841c50d8ae3SPaolo Bonzini } 1842c50d8ae3SPaolo Bonzini 1843c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1844c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1845c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1846c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1847c50d8ae3SPaolo Bonzini 1848767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1849767d8d8dSLai Jiangshan { 1850767d8d8dSLai Jiangshan if (sp->role.direct) 1851767d8d8dSLai Jiangshan return false; 1852767d8d8dSLai Jiangshan 185384e5ffd0SLai Jiangshan if (sp->role.passthrough) 185484e5ffd0SLai Jiangshan return false; 185584e5ffd0SLai Jiangshan 1856767d8d8dSLai Jiangshan return true; 1857767d8d8dSLai Jiangshan } 1858767d8d8dSLai Jiangshan 1859ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1860ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1861c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1862c50d8ae3SPaolo Bonzini } else 1863c50d8ae3SPaolo Bonzini 1864767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1865ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1866ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1867767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1868c50d8ae3SPaolo Bonzini 18698d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1870c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1871c50d8ae3SPaolo Bonzini { 1872c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1873c3e5e415SLai Jiangshan 18748d5678a7SHou Wenlong if (ret < 0) 1875c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 18768d5678a7SHou Wenlong return ret; 1877c50d8ae3SPaolo Bonzini } 1878c50d8ae3SPaolo Bonzini 1879c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1880c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1881c50d8ae3SPaolo Bonzini bool remote_flush) 1882c50d8ae3SPaolo Bonzini { 1883c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1884c50d8ae3SPaolo Bonzini return false; 1885c50d8ae3SPaolo Bonzini 1886c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1887c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1888c50d8ae3SPaolo Bonzini else 1889c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1890c50d8ae3SPaolo Bonzini return true; 1891c50d8ae3SPaolo Bonzini } 1892c50d8ae3SPaolo Bonzini 1893c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1894c50d8ae3SPaolo Bonzini { 1895a955cad8SSean Christopherson if (sp->role.invalid) 1896a955cad8SSean Christopherson return true; 1897a955cad8SSean Christopherson 1898fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 1899a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1900c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1901c50d8ae3SPaolo Bonzini } 1902c50d8ae3SPaolo Bonzini 1903c50d8ae3SPaolo Bonzini struct mmu_page_path { 1904c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1905c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1906c50d8ae3SPaolo Bonzini }; 1907c50d8ae3SPaolo Bonzini 1908c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1909c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1910c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1911c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1912c50d8ae3SPaolo Bonzini 1913c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1914c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1915c50d8ae3SPaolo Bonzini int i) 1916c50d8ae3SPaolo Bonzini { 1917c50d8ae3SPaolo Bonzini int n; 1918c50d8ae3SPaolo Bonzini 1919c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1920c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1921c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1922c50d8ae3SPaolo Bonzini int level = sp->role.level; 1923c50d8ae3SPaolo Bonzini 1924c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19253bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1926c50d8ae3SPaolo Bonzini break; 1927c50d8ae3SPaolo Bonzini 1928c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1929c50d8ae3SPaolo Bonzini } 1930c50d8ae3SPaolo Bonzini 1931c50d8ae3SPaolo Bonzini return n; 1932c50d8ae3SPaolo Bonzini } 1933c50d8ae3SPaolo Bonzini 1934c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1935c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1936c50d8ae3SPaolo Bonzini { 1937c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1938c50d8ae3SPaolo Bonzini int level; 1939c50d8ae3SPaolo Bonzini 1940c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1941c50d8ae3SPaolo Bonzini return 0; 1942c50d8ae3SPaolo Bonzini 1943c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1944c50d8ae3SPaolo Bonzini 1945c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1946c50d8ae3SPaolo Bonzini level = sp->role.level; 19473bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1948c50d8ae3SPaolo Bonzini 1949c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1950c50d8ae3SPaolo Bonzini 1951c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1952c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1953c50d8ae3SPaolo Bonzini */ 1954c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1955c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1956c50d8ae3SPaolo Bonzini } 1957c50d8ae3SPaolo Bonzini 1958c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1959c50d8ae3SPaolo Bonzini { 1960c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1961c50d8ae3SPaolo Bonzini unsigned int level = 0; 1962c50d8ae3SPaolo Bonzini 1963c50d8ae3SPaolo Bonzini do { 1964c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1965c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1966c50d8ae3SPaolo Bonzini if (!sp) 1967c50d8ae3SPaolo Bonzini return; 1968c50d8ae3SPaolo Bonzini 1969c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 1970c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 1971c50d8ae3SPaolo Bonzini level++; 1972c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 1973c50d8ae3SPaolo Bonzini } 1974c50d8ae3SPaolo Bonzini 197565855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 197665855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 1977c50d8ae3SPaolo Bonzini { 1978c50d8ae3SPaolo Bonzini int i; 1979c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1980c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 1981c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 1982c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 1983c50d8ae3SPaolo Bonzini bool flush = false; 1984c50d8ae3SPaolo Bonzini 1985c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 1986c50d8ae3SPaolo Bonzini bool protected = false; 1987c50d8ae3SPaolo Bonzini 1988c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 1989cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 1990c50d8ae3SPaolo Bonzini 1991c50d8ae3SPaolo Bonzini if (protected) { 19925591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 1993c50d8ae3SPaolo Bonzini flush = false; 1994c50d8ae3SPaolo Bonzini } 1995c50d8ae3SPaolo Bonzini 1996c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 1997479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 19988d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 1999c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2000c50d8ae3SPaolo Bonzini } 2001531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2002c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 200365855ed8SLai Jiangshan if (!can_yield) { 200465855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 200565855ed8SLai Jiangshan return -EINTR; 200665855ed8SLai Jiangshan } 200765855ed8SLai Jiangshan 2008531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2009c50d8ae3SPaolo Bonzini flush = false; 2010c50d8ae3SPaolo Bonzini } 2011c50d8ae3SPaolo Bonzini } 2012c50d8ae3SPaolo Bonzini 2013c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 201465855ed8SLai Jiangshan return 0; 2015c50d8ae3SPaolo Bonzini } 2016c50d8ae3SPaolo Bonzini 2017c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2018c50d8ae3SPaolo Bonzini { 2019c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2020c50d8ae3SPaolo Bonzini } 2021c50d8ae3SPaolo Bonzini 2022c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2023c50d8ae3SPaolo Bonzini { 202457354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2025c50d8ae3SPaolo Bonzini } 2026c50d8ae3SPaolo Bonzini 2027cbd858b1SDavid Matlack /* 2028cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2029cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2030cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2031cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2032cbd858b1SDavid Matlack */ 20333cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 20343cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 203594c81364SDavid Matlack gfn_t gfn, 203694c81364SDavid Matlack struct hlist_head *sp_list, 20372e65e842SDavid Matlack union kvm_mmu_page_role role) 2038c50d8ae3SPaolo Bonzini { 2039c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20408d5678a7SHou Wenlong int ret; 2041c50d8ae3SPaolo Bonzini int collisions = 0; 2042c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2043c50d8ae3SPaolo Bonzini 20443cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2045c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2046c50d8ae3SPaolo Bonzini collisions++; 2047c50d8ae3SPaolo Bonzini continue; 2048c50d8ae3SPaolo Bonzini } 2049c50d8ae3SPaolo Bonzini 2050ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2051ddc16abbSSean Christopherson /* 2052ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2053ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2054ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2055ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2056ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2057ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2058ddc16abbSSean Christopherson * upper-level page will be write-protected. 2059ddc16abbSSean Christopherson */ 20602e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 20613cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2062ddc16abbSSean Christopherson &invalid_list); 2063c50d8ae3SPaolo Bonzini continue; 2064ddc16abbSSean Christopherson } 2065c50d8ae3SPaolo Bonzini 2066bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2067bb924ca6SDavid Matlack if (sp->role.direct) 206894c81364SDavid Matlack goto out; 2069fb58a9c3SSean Christopherson 2070c50d8ae3SPaolo Bonzini if (sp->unsync) { 2071cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2072cbd858b1SDavid Matlack break; 2073cbd858b1SDavid Matlack 207407dc4f35SSean Christopherson /* 2075479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 207607dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 207707dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 207807dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 207907dc4f35SSean Christopherson * overhead of write protection is not incurred until the 208007dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 208107dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 208207dc4f35SSean Christopherson * 208307dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 208407dc4f35SSean Christopherson * in order to rebuild it. 2085c50d8ae3SPaolo Bonzini */ 20868d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 20878d5678a7SHou Wenlong if (ret < 0) 2088c50d8ae3SPaolo Bonzini break; 2089c50d8ae3SPaolo Bonzini 2090c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 20918d5678a7SHou Wenlong if (ret > 0) 20923cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2093c50d8ae3SPaolo Bonzini } 2094c50d8ae3SPaolo Bonzini 2095c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2096fb58a9c3SSean Christopherson 2097c50d8ae3SPaolo Bonzini goto out; 2098c50d8ae3SPaolo Bonzini } 2099c50d8ae3SPaolo Bonzini 210094c81364SDavid Matlack sp = NULL; 21013cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2102c50d8ae3SPaolo Bonzini 210394c81364SDavid Matlack out: 21043cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 210594c81364SDavid Matlack 21063cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 21073cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 210894c81364SDavid Matlack return sp; 210994c81364SDavid Matlack } 211094c81364SDavid Matlack 21112f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 21122f8b1b53SDavid Matlack struct shadow_page_caches { 21132f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 21142f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 21156a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 21162f8b1b53SDavid Matlack }; 21172f8b1b53SDavid Matlack 2118336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 21192f8b1b53SDavid Matlack struct shadow_page_caches *caches, 212094c81364SDavid Matlack gfn_t gfn, 212194c81364SDavid Matlack struct hlist_head *sp_list, 212294c81364SDavid Matlack union kvm_mmu_page_role role) 212394c81364SDavid Matlack { 2124c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2125c306aec8SDavid Matlack 21262f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 21272f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2128c306aec8SDavid Matlack if (!role.direct) 21296a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2130c306aec8SDavid Matlack 2131c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2132c306aec8SDavid Matlack 2133c306aec8SDavid Matlack /* 2134c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2135c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2136c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2137c306aec8SDavid Matlack */ 2138336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2139336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 214043a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2141c50d8ae3SPaolo Bonzini 2142c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2143c50d8ae3SPaolo Bonzini sp->role = role; 2144ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2145be911771SDavid Matlack if (sp_has_gptes(sp)) 2146336081fbSDavid Matlack account_shadowed(kvm, sp); 2147ddc16abbSSean Christopherson 214894c81364SDavid Matlack return sp; 214994c81364SDavid Matlack } 215094c81364SDavid Matlack 2151cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 21523cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 21533cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 21542f8b1b53SDavid Matlack struct shadow_page_caches *caches, 215587654643SDavid Matlack gfn_t gfn, 215694c81364SDavid Matlack union kvm_mmu_page_role role) 215794c81364SDavid Matlack { 215894c81364SDavid Matlack struct hlist_head *sp_list; 215994c81364SDavid Matlack struct kvm_mmu_page *sp; 216094c81364SDavid Matlack bool created = false; 216194c81364SDavid Matlack 21623cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 216394c81364SDavid Matlack 21643cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 216594c81364SDavid Matlack if (!sp) { 216694c81364SDavid Matlack created = true; 21673cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 216894c81364SDavid Matlack } 216994c81364SDavid Matlack 217094c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2171c50d8ae3SPaolo Bonzini return sp; 2172c50d8ae3SPaolo Bonzini } 2173c50d8ae3SPaolo Bonzini 21742f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 21752f8b1b53SDavid Matlack gfn_t gfn, 21762f8b1b53SDavid Matlack union kvm_mmu_page_role role) 21772f8b1b53SDavid Matlack { 21782f8b1b53SDavid Matlack struct shadow_page_caches caches = { 21792f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 21802f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 21816a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 21822f8b1b53SDavid Matlack }; 21832f8b1b53SDavid Matlack 21843cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 21852f8b1b53SDavid Matlack } 21862f8b1b53SDavid Matlack 218739944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 218839944ab9SSean Christopherson unsigned int access) 21892e65e842SDavid Matlack { 21902e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 21912e65e842SDavid Matlack union kvm_mmu_page_role role; 21922e65e842SDavid Matlack 21932e65e842SDavid Matlack role = parent_sp->role; 21942e65e842SDavid Matlack role.level--; 21952e65e842SDavid Matlack role.access = access; 21962e65e842SDavid Matlack role.direct = direct; 21972e65e842SDavid Matlack role.passthrough = 0; 21982e65e842SDavid Matlack 21992e65e842SDavid Matlack /* 22002e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 22012e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 22022e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 22032e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 22042e65e842SDavid Matlack * requires extra bookkeeping in the role. 22052e65e842SDavid Matlack * 22062e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 22072e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 22082e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 22092e65e842SDavid Matlack * the address space each maps. 22102e65e842SDavid Matlack * 22112e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 22122e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 22132e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 22142e65e842SDavid Matlack * 221539944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 221639944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 221739944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 221839944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 221939944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 222039944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 222139944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 222239944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 222339944ab9SSean Christopherson * _least_ significant bit of the PDE index. 22242e65e842SDavid Matlack */ 22252e65e842SDavid Matlack if (role.has_4_byte_gpte) { 22262e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 222779e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 22282e65e842SDavid Matlack } 22292e65e842SDavid Matlack 22302e65e842SDavid Matlack return role; 22312e65e842SDavid Matlack } 22322e65e842SDavid Matlack 22332e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 22342e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 22352e65e842SDavid Matlack bool direct, unsigned int access) 22362e65e842SDavid Matlack { 22372e65e842SDavid Matlack union kvm_mmu_page_role role; 22382e65e842SDavid Matlack 22390cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 22400cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 22410cd8dc73SPaolo Bonzini 22422e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 224387654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 22442e65e842SDavid Matlack } 22452e65e842SDavid Matlack 2246c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2247c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2248c50d8ae3SPaolo Bonzini u64 addr) 2249c50d8ae3SPaolo Bonzini { 2250c50d8ae3SPaolo Bonzini iterator->addr = addr; 2251c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2252a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2253c50d8ae3SPaolo Bonzini 225412ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 22554d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2256347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 225712ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2258c50d8ae3SPaolo Bonzini 2259c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2260c50d8ae3SPaolo Bonzini /* 2261c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2262c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2263c50d8ae3SPaolo Bonzini */ 2264b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2265c50d8ae3SPaolo Bonzini 2266c50d8ae3SPaolo Bonzini iterator->shadow_addr 2267c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 22682ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2269c50d8ae3SPaolo Bonzini --iterator->level; 2270c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2271c50d8ae3SPaolo Bonzini iterator->level = 0; 2272c50d8ae3SPaolo Bonzini } 2273c50d8ae3SPaolo Bonzini } 2274c50d8ae3SPaolo Bonzini 2275c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2276c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2277c50d8ae3SPaolo Bonzini { 2278b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2279c50d8ae3SPaolo Bonzini addr); 2280c50d8ae3SPaolo Bonzini } 2281c50d8ae3SPaolo Bonzini 2282c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2283c50d8ae3SPaolo Bonzini { 22843bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2285c50d8ae3SPaolo Bonzini return false; 2286c50d8ae3SPaolo Bonzini 22872ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2288c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2289c50d8ae3SPaolo Bonzini return true; 2290c50d8ae3SPaolo Bonzini } 2291c50d8ae3SPaolo Bonzini 2292c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2293c50d8ae3SPaolo Bonzini u64 spte) 2294c50d8ae3SPaolo Bonzini { 22953e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2296c50d8ae3SPaolo Bonzini iterator->level = 0; 2297c50d8ae3SPaolo Bonzini return; 2298c50d8ae3SPaolo Bonzini } 2299c50d8ae3SPaolo Bonzini 23002ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2301c50d8ae3SPaolo Bonzini --iterator->level; 2302c50d8ae3SPaolo Bonzini } 2303c50d8ae3SPaolo Bonzini 2304c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2305c50d8ae3SPaolo Bonzini { 2306c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2307c50d8ae3SPaolo Bonzini } 2308c50d8ae3SPaolo Bonzini 23090cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 23100cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 231103787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2312c50d8ae3SPaolo Bonzini { 2313c50d8ae3SPaolo Bonzini u64 spte; 2314c50d8ae3SPaolo Bonzini 2315c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2316c50d8ae3SPaolo Bonzini 23170cd8dc73SPaolo Bonzini /* 23180cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 231903787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 232003787394SPaolo Bonzini * installing sp. 23210cd8dc73SPaolo Bonzini */ 23220cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 232303787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 23240cd8dc73SPaolo Bonzini 2325cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2326c50d8ae3SPaolo Bonzini 2327c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2328c50d8ae3SPaolo Bonzini 23292ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2330c50d8ae3SPaolo Bonzini 2331c50d8ae3SPaolo Bonzini if (sp->unsync_children || sp->unsync) 2332c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2333c50d8ae3SPaolo Bonzini } 2334c50d8ae3SPaolo Bonzini 23352ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 23362ff9039aSDavid Matlack struct kvm_mmu_page *sp) 23372ff9039aSDavid Matlack { 233803787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 23392ff9039aSDavid Matlack } 23402ff9039aSDavid Matlack 2341c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2342c50d8ae3SPaolo Bonzini unsigned direct_access) 2343c50d8ae3SPaolo Bonzini { 2344c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2345c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2346c50d8ae3SPaolo Bonzini 2347c50d8ae3SPaolo Bonzini /* 2348c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2349c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2350c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2351c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2352c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2353c50d8ae3SPaolo Bonzini */ 23542ca3129eSSean Christopherson child = to_shadow_page(*sptep & SPTE_BASE_ADDR_MASK); 2355c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2356c50d8ae3SPaolo Bonzini return; 2357c50d8ae3SPaolo Bonzini 2358c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2359c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2360c50d8ae3SPaolo Bonzini } 2361c50d8ae3SPaolo Bonzini } 2362c50d8ae3SPaolo Bonzini 23632de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 23642de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 23652de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2366c50d8ae3SPaolo Bonzini { 2367c50d8ae3SPaolo Bonzini u64 pte; 2368c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2369c50d8ae3SPaolo Bonzini 2370c50d8ae3SPaolo Bonzini pte = *spte; 2371c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2372c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2373c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2374c50d8ae3SPaolo Bonzini } else { 23752ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2376c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 23772de4085cSBen Gardon 23782de4085cSBen Gardon /* 23792de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 23802de4085cSBen Gardon * unlikely to be used again in the near future. This 23812de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 23822de4085cSBen Gardon */ 23832de4085cSBen Gardon if (tdp_enabled && invalid_list && 23842de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 23852de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 23862de4085cSBen Gardon invalid_list); 2387c50d8ae3SPaolo Bonzini } 2388ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2389c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2390ace569e0SSean Christopherson } 23912de4085cSBen Gardon return 0; 2392c50d8ae3SPaolo Bonzini } 2393c50d8ae3SPaolo Bonzini 23942de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 23952de4085cSBen Gardon struct kvm_mmu_page *sp, 23962de4085cSBen Gardon struct list_head *invalid_list) 2397c50d8ae3SPaolo Bonzini { 23982de4085cSBen Gardon int zapped = 0; 2399c50d8ae3SPaolo Bonzini unsigned i; 2400c50d8ae3SPaolo Bonzini 24012ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 24022de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 24032de4085cSBen Gardon 24042de4085cSBen Gardon return zapped; 2405c50d8ae3SPaolo Bonzini } 2406c50d8ae3SPaolo Bonzini 240761827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2408c50d8ae3SPaolo Bonzini { 2409c50d8ae3SPaolo Bonzini u64 *sptep; 2410c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2411c50d8ae3SPaolo Bonzini 2412c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2413c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2414c50d8ae3SPaolo Bonzini } 2415c50d8ae3SPaolo Bonzini 2416c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2417c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2418c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2419c50d8ae3SPaolo Bonzini { 2420c50d8ae3SPaolo Bonzini int i, zapped = 0; 2421c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2422c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2423c50d8ae3SPaolo Bonzini 24243bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2425c50d8ae3SPaolo Bonzini return 0; 2426c50d8ae3SPaolo Bonzini 2427c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2428c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2429c50d8ae3SPaolo Bonzini 2430c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2431c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2432c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2433c50d8ae3SPaolo Bonzini zapped++; 2434c50d8ae3SPaolo Bonzini } 2435c50d8ae3SPaolo Bonzini } 2436c50d8ae3SPaolo Bonzini 2437c50d8ae3SPaolo Bonzini return zapped; 2438c50d8ae3SPaolo Bonzini } 2439c50d8ae3SPaolo Bonzini 2440c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2441c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2442c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2443c50d8ae3SPaolo Bonzini int *nr_zapped) 2444c50d8ae3SPaolo Bonzini { 2445527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2446c50d8ae3SPaolo Bonzini 2447c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2448c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2449c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 24502de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 245161827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2452c50d8ae3SPaolo Bonzini 2453c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2454c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2455c50d8ae3SPaolo Bonzini 2456767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2457c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2458c50d8ae3SPaolo Bonzini 2459c50d8ae3SPaolo Bonzini if (sp->unsync) 2460c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2461c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2462c50d8ae3SPaolo Bonzini /* Count self */ 2463c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2464f95eec9bSSean Christopherson 2465f95eec9bSSean Christopherson /* 2466f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2467f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2468f95eec9bSSean Christopherson * !sp->root_count. 2469f95eec9bSSean Christopherson */ 2470f95eec9bSSean Christopherson if (sp->role.invalid) 2471f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2472f95eec9bSSean Christopherson else 2473c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 247443a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2475c50d8ae3SPaolo Bonzini } else { 2476f95eec9bSSean Christopherson /* 2477f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2478f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2479f95eec9bSSean Christopherson */ 2480f95eec9bSSean Christopherson list_del(&sp->link); 2481c50d8ae3SPaolo Bonzini 2482c50d8ae3SPaolo Bonzini /* 2483c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2484c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2485c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2486c50d8ae3SPaolo Bonzini */ 2487527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2488c50d8ae3SPaolo Bonzini } 2489c50d8ae3SPaolo Bonzini 2490c50d8ae3SPaolo Bonzini if (sp->lpage_disallowed) 2491c50d8ae3SPaolo Bonzini unaccount_huge_nx_page(kvm, sp); 2492c50d8ae3SPaolo Bonzini 2493c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2494527d5cd7SSean Christopherson 2495527d5cd7SSean Christopherson /* 2496527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2497527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2498527d5cd7SSean Christopherson */ 2499527d5cd7SSean Christopherson if (zapped_root) 2500527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2501c50d8ae3SPaolo Bonzini return list_unstable; 2502c50d8ae3SPaolo Bonzini } 2503c50d8ae3SPaolo Bonzini 2504c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2505c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2506c50d8ae3SPaolo Bonzini { 2507c50d8ae3SPaolo Bonzini int nr_zapped; 2508c50d8ae3SPaolo Bonzini 2509c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2510c50d8ae3SPaolo Bonzini return nr_zapped; 2511c50d8ae3SPaolo Bonzini } 2512c50d8ae3SPaolo Bonzini 2513c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2514c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2515c50d8ae3SPaolo Bonzini { 2516c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2517c50d8ae3SPaolo Bonzini 2518c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2519c50d8ae3SPaolo Bonzini return; 2520c50d8ae3SPaolo Bonzini 2521c50d8ae3SPaolo Bonzini /* 2522c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2523c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2524c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2525c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2526c50d8ae3SPaolo Bonzini * 2527c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2528c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2529c50d8ae3SPaolo Bonzini */ 2530c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2531c50d8ae3SPaolo Bonzini 2532c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2533c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 253487654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2535c50d8ae3SPaolo Bonzini } 2536c50d8ae3SPaolo Bonzini } 2537c50d8ae3SPaolo Bonzini 25386b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 25396b82ef2cSSean Christopherson unsigned long nr_to_zap) 2540c50d8ae3SPaolo Bonzini { 25416b82ef2cSSean Christopherson unsigned long total_zapped = 0; 25426b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2543ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 25446b82ef2cSSean Christopherson bool unstable; 25456b82ef2cSSean Christopherson int nr_zapped; 2546c50d8ae3SPaolo Bonzini 2547c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2548ba7888ddSSean Christopherson return 0; 2549c50d8ae3SPaolo Bonzini 25506b82ef2cSSean Christopherson restart: 25518fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 25526b82ef2cSSean Christopherson /* 25536b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 25546b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 25556b82ef2cSSean Christopherson */ 25566b82ef2cSSean Christopherson if (sp->root_count) 25576b82ef2cSSean Christopherson continue; 25586b82ef2cSSean Christopherson 25596b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 25606b82ef2cSSean Christopherson &nr_zapped); 25616b82ef2cSSean Christopherson total_zapped += nr_zapped; 25626b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2563ba7888ddSSean Christopherson break; 2564ba7888ddSSean Christopherson 25656b82ef2cSSean Christopherson if (unstable) 25666b82ef2cSSean Christopherson goto restart; 2567ba7888ddSSean Christopherson } 25686b82ef2cSSean Christopherson 25696b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 25706b82ef2cSSean Christopherson 25716b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 25726b82ef2cSSean Christopherson return total_zapped; 25736b82ef2cSSean Christopherson } 25746b82ef2cSSean Christopherson 2575afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2576afe8d7e6SSean Christopherson { 2577afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2578afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2579afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2580afe8d7e6SSean Christopherson 2581afe8d7e6SSean Christopherson return 0; 2582c50d8ae3SPaolo Bonzini } 2583c50d8ae3SPaolo Bonzini 2584ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2585ba7888ddSSean Christopherson { 25866b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2587ba7888ddSSean Christopherson 25886b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2589ba7888ddSSean Christopherson return 0; 2590ba7888ddSSean Christopherson 25916b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2592ba7888ddSSean Christopherson 25936e6ec584SSean Christopherson /* 25946e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 25956e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 25966e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 25976e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2598c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 25996e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 26006e6ec584SSean Christopherson * page fault paths. 26016e6ec584SSean Christopherson */ 2602ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2603ba7888ddSSean Christopherson return -ENOSPC; 2604ba7888ddSSean Christopherson return 0; 2605ba7888ddSSean Christopherson } 2606ba7888ddSSean Christopherson 2607c50d8ae3SPaolo Bonzini /* 2608c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2609c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2610c50d8ae3SPaolo Bonzini */ 2611c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2612c50d8ae3SPaolo Bonzini { 2613531810caSBen Gardon write_lock(&kvm->mmu_lock); 2614c50d8ae3SPaolo Bonzini 2615c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 26166b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 26176b82ef2cSSean Christopherson goal_nr_mmu_pages); 2618c50d8ae3SPaolo Bonzini 2619c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2620c50d8ae3SPaolo Bonzini } 2621c50d8ae3SPaolo Bonzini 2622c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2623c50d8ae3SPaolo Bonzini 2624531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2625c50d8ae3SPaolo Bonzini } 2626c50d8ae3SPaolo Bonzini 2627c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2628c50d8ae3SPaolo Bonzini { 2629c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2630c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2631c50d8ae3SPaolo Bonzini int r; 2632c50d8ae3SPaolo Bonzini 2633c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2634c50d8ae3SPaolo Bonzini r = 0; 2635531810caSBen Gardon write_lock(&kvm->mmu_lock); 2636767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2637c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2638c50d8ae3SPaolo Bonzini sp->role.word); 2639c50d8ae3SPaolo Bonzini r = 1; 2640c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2641c50d8ae3SPaolo Bonzini } 2642c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2643531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2644c50d8ae3SPaolo Bonzini 2645c50d8ae3SPaolo Bonzini return r; 2646c50d8ae3SPaolo Bonzini } 264796ad91aeSSean Christopherson 264896ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 264996ad91aeSSean Christopherson { 265096ad91aeSSean Christopherson gpa_t gpa; 265196ad91aeSSean Christopherson int r; 265296ad91aeSSean Christopherson 2653347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 265496ad91aeSSean Christopherson return 0; 265596ad91aeSSean Christopherson 265696ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 265796ad91aeSSean Christopherson 265896ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 265996ad91aeSSean Christopherson 266096ad91aeSSean Christopherson return r; 266196ad91aeSSean Christopherson } 2662c50d8ae3SPaolo Bonzini 26634d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2664c50d8ae3SPaolo Bonzini { 2665c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 26664d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2667c50d8ae3SPaolo Bonzini sp->unsync = 1; 2668c50d8ae3SPaolo Bonzini 2669c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2670c50d8ae3SPaolo Bonzini } 2671c50d8ae3SPaolo Bonzini 26720337f585SSean Christopherson /* 26730337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 26740337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 26750337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 26760337f585SSean Christopherson * be write-protected. 26770337f585SSean Christopherson */ 26788283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 26792839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2680c50d8ae3SPaolo Bonzini { 2681c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2682ce25681dSSean Christopherson bool locked = false; 2683c50d8ae3SPaolo Bonzini 26840337f585SSean Christopherson /* 26850337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 26860337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 26870337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 26880337f585SSean Christopherson */ 26894d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 26900337f585SSean Christopherson return -EPERM; 2691c50d8ae3SPaolo Bonzini 26920337f585SSean Christopherson /* 26930337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 26940337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 26950337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 26960337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 26970337f585SSean Christopherson */ 2698767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2699c50d8ae3SPaolo Bonzini if (!can_unsync) 27000337f585SSean Christopherson return -EPERM; 2701c50d8ae3SPaolo Bonzini 2702c50d8ae3SPaolo Bonzini if (sp->unsync) 2703c50d8ae3SPaolo Bonzini continue; 2704c50d8ae3SPaolo Bonzini 27052839180cSPaolo Bonzini if (prefetch) 2706f1c4a88cSLai Jiangshan return -EEXIST; 2707f1c4a88cSLai Jiangshan 2708ce25681dSSean Christopherson /* 2709ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2710ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2711ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2712ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2713ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2714ce25681dSSean Christopherson */ 2715ce25681dSSean Christopherson if (!locked) { 2716ce25681dSSean Christopherson locked = true; 27174d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2718ce25681dSSean Christopherson 2719ce25681dSSean Christopherson /* 2720ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2721ce25681dSSean Christopherson * may have since marked the page unsync. A false 2722ce25681dSSean Christopherson * positive on the unprotected check above is not 2723ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2724ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2725ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2726ce25681dSSean Christopherson */ 2727ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2728ce25681dSSean Christopherson continue; 2729ce25681dSSean Christopherson } 2730ce25681dSSean Christopherson 27313bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 27324d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2733c50d8ae3SPaolo Bonzini } 2734ce25681dSSean Christopherson if (locked) 27354d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2736c50d8ae3SPaolo Bonzini 2737c50d8ae3SPaolo Bonzini /* 2738c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2739c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2740c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2741c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2742c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2743c50d8ae3SPaolo Bonzini * following could happen: 2744c50d8ae3SPaolo Bonzini * 2745c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2746c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2747c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2748c50d8ae3SPaolo Bonzini * to be writable 2749c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2750c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2751c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2752c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2753c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2754c50d8ae3SPaolo Bonzini * fault. 2755c50d8ae3SPaolo Bonzini * 2756c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2757c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2758c50d8ae3SPaolo Bonzini * 27590337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 27600337f585SSean Christopherson * false and skips the page. 2761c50d8ae3SPaolo Bonzini * 2762c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2763c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2764c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2765c50d8ae3SPaolo Bonzini * gets used. 2766c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2767c50d8ae3SPaolo Bonzini * as unsync 2768c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2769c50d8ae3SPaolo Bonzini * 2770c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2771264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2772264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2773c50d8ae3SPaolo Bonzini */ 2774c50d8ae3SPaolo Bonzini smp_wmb(); 2775c50d8ae3SPaolo Bonzini 27760337f585SSean Christopherson return 0; 2777c50d8ae3SPaolo Bonzini } 2778c50d8ae3SPaolo Bonzini 27798a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 27808a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2781a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2782799a4190SBen Gardon { 2783d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2784eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2785c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2786c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2787c50d8ae3SPaolo Bonzini bool flush = false; 2788ad67e480SPaolo Bonzini bool wrprot; 2789d786c778SPaolo Bonzini u64 spte; 2790c50d8ae3SPaolo Bonzini 2791a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2792a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 27932839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2794a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2795c50d8ae3SPaolo Bonzini 2796c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2797c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2798c50d8ae3SPaolo Bonzini 2799a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 28001075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2801a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2802a54aa15cSSean Christopherson return RET_PF_EMULATE; 2803a54aa15cSSean Christopherson } 2804a54aa15cSSean Christopherson 2805c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2806c50d8ae3SPaolo Bonzini /* 2807c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2808c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2809c50d8ae3SPaolo Bonzini */ 28103bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2811c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2812c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2813c50d8ae3SPaolo Bonzini 28142ca3129eSSean Christopherson child = to_shadow_page(pte & SPTE_BASE_ADDR_MASK); 2815c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2816c50d8ae3SPaolo Bonzini flush = true; 2817c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2818c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2819c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2820c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2821c50d8ae3SPaolo Bonzini flush = true; 2822c50d8ae3SPaolo Bonzini } else 2823c50d8ae3SPaolo Bonzini was_rmapped = 1; 2824c50d8ae3SPaolo Bonzini } 2825c50d8ae3SPaolo Bonzini 28262839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 28277158bee4SPaolo Bonzini true, host_writable, &spte); 2828d786c778SPaolo Bonzini 2829d786c778SPaolo Bonzini if (*sptep == spte) { 2830d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2831d786c778SPaolo Bonzini } else { 2832d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 28335959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2834c50d8ae3SPaolo Bonzini } 2835c50d8ae3SPaolo Bonzini 2836ad67e480SPaolo Bonzini if (wrprot) { 2837c50d8ae3SPaolo Bonzini if (write_fault) 2838c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2839c50d8ae3SPaolo Bonzini } 2840c50d8ae3SPaolo Bonzini 2841d786c778SPaolo Bonzini if (flush) 2842c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2843c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2844c50d8ae3SPaolo Bonzini 2845c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2846c50d8ae3SPaolo Bonzini 2847c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2848d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 28496a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 28506a97575dSDavid Matlack } else { 28516a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 285279e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2853c50d8ae3SPaolo Bonzini } 2854c50d8ae3SPaolo Bonzini 2855c50d8ae3SPaolo Bonzini return ret; 2856c50d8ae3SPaolo Bonzini } 2857c50d8ae3SPaolo Bonzini 2858c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2859c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2860c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2861c50d8ae3SPaolo Bonzini { 2862c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2863c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 28640a2b64c5SBen Gardon unsigned int access = sp->role.access; 2865c50d8ae3SPaolo Bonzini int i, ret; 2866c50d8ae3SPaolo Bonzini gfn_t gfn; 2867c50d8ae3SPaolo Bonzini 286879e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 2869c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2870c50d8ae3SPaolo Bonzini if (!slot) 2871c50d8ae3SPaolo Bonzini return -1; 2872c50d8ae3SPaolo Bonzini 2873c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2874c50d8ae3SPaolo Bonzini if (ret <= 0) 2875c50d8ae3SPaolo Bonzini return -1; 2876c50d8ae3SPaolo Bonzini 2877c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 28788a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2879a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2880c50d8ae3SPaolo Bonzini put_page(pages[i]); 2881c50d8ae3SPaolo Bonzini } 2882c50d8ae3SPaolo Bonzini 2883c50d8ae3SPaolo Bonzini return 0; 2884c50d8ae3SPaolo Bonzini } 2885c50d8ae3SPaolo Bonzini 2886c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2887c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2888c50d8ae3SPaolo Bonzini { 2889c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2890c50d8ae3SPaolo Bonzini int i; 2891c50d8ae3SPaolo Bonzini 2892c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2893c50d8ae3SPaolo Bonzini 289479e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 2895c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2896c50d8ae3SPaolo Bonzini 2897c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2898c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2899c50d8ae3SPaolo Bonzini if (!start) 2900c50d8ae3SPaolo Bonzini continue; 2901c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2902c6cecc4bSSean Christopherson return; 2903c50d8ae3SPaolo Bonzini start = NULL; 2904c50d8ae3SPaolo Bonzini } else if (!start) 2905c50d8ae3SPaolo Bonzini start = spte; 2906c50d8ae3SPaolo Bonzini } 2907c6cecc4bSSean Christopherson if (start) 2908c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2909c50d8ae3SPaolo Bonzini } 2910c50d8ae3SPaolo Bonzini 2911c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2912c50d8ae3SPaolo Bonzini { 2913c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2914c50d8ae3SPaolo Bonzini 291557354682SSean Christopherson sp = sptep_to_sp(sptep); 2916c50d8ae3SPaolo Bonzini 2917c50d8ae3SPaolo Bonzini /* 2918c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2919c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2920c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2921c50d8ae3SPaolo Bonzini */ 2922c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2923c50d8ae3SPaolo Bonzini return; 2924c50d8ae3SPaolo Bonzini 29253bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2926c50d8ae3SPaolo Bonzini return; 2927c50d8ae3SPaolo Bonzini 29284a42d848SDavid Stevens /* 29294a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 29304a42d848SDavid Stevens * accidentally prefetching those addresses. 29314a42d848SDavid Stevens */ 293220ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 29334a42d848SDavid Stevens return; 29344a42d848SDavid Stevens 2935c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2936c50d8ae3SPaolo Bonzini } 2937c50d8ae3SPaolo Bonzini 293865e3b446SSean Christopherson /* 293965e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 294065e3b446SSean Christopherson * 294165e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 294265e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 294365e3b446SSean Christopherson * 294465e3b446SSean Christopherson * There are several ways to safely use this helper: 294565e3b446SSean Christopherson * 294620ec3ebdSChao Peng * - Check mmu_invalidate_retry_hva() after grabbing the mapping level, before 294765e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 294865e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 294965e3b446SSean Christopherson * 295065e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 295165e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 295265e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 295365e3b446SSean Christopherson * 295465e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 295565e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 295665e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 295765e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 295865e3b446SSean Christopherson * 295965e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 296065e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 296165e3b446SSean Christopherson * race with the primary MMU occurs. 296265e3b446SSean Christopherson */ 2963a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 29648ca6f063SBen Gardon const struct kvm_memory_slot *slot) 2965db543216SSean Christopherson { 2966284dc493SSean Christopherson int level = PG_LEVEL_4K; 2967db543216SSean Christopherson unsigned long hva; 296844187235SMingwei Zhang unsigned long flags; 296944187235SMingwei Zhang pgd_t pgd; 297044187235SMingwei Zhang p4d_t p4d; 297144187235SMingwei Zhang pud_t pud; 297244187235SMingwei Zhang pmd_t pmd; 2973db543216SSean Christopherson 29745d49f08cSSean Christopherson /* 2975293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 2976293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 2977293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 2978293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 2979293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 2980293e306eSSean Christopherson * read-only memslot. 2981293e306eSSean Christopherson */ 2982db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 2983db543216SSean Christopherson 298444187235SMingwei Zhang /* 298565e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 298665e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 298765e3b446SSean Christopherson * the original page table. 298844187235SMingwei Zhang */ 298944187235SMingwei Zhang local_irq_save(flags); 2990db543216SSean Christopherson 299165e3b446SSean Christopherson /* 299265e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 299365e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 299465e3b446SSean Christopherson * walk into the weeks, e.g. p*d_large() returns false (sees the old 299565e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 299665e3b446SSean Christopherson * of the old page table (sees the new value). 299765e3b446SSean Christopherson */ 299844187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 299944187235SMingwei Zhang if (pgd_none(pgd)) 300044187235SMingwei Zhang goto out; 300144187235SMingwei Zhang 300244187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 300344187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 300444187235SMingwei Zhang goto out; 300544187235SMingwei Zhang 300644187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 300744187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 300844187235SMingwei Zhang goto out; 300944187235SMingwei Zhang 301044187235SMingwei Zhang if (pud_large(pud)) { 301144187235SMingwei Zhang level = PG_LEVEL_1G; 301244187235SMingwei Zhang goto out; 301344187235SMingwei Zhang } 301444187235SMingwei Zhang 301544187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 301644187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 301744187235SMingwei Zhang goto out; 301844187235SMingwei Zhang 301944187235SMingwei Zhang if (pmd_large(pmd)) 302044187235SMingwei Zhang level = PG_LEVEL_2M; 302144187235SMingwei Zhang 302244187235SMingwei Zhang out: 302344187235SMingwei Zhang local_irq_restore(flags); 3024db543216SSean Christopherson return level; 3025db543216SSean Christopherson } 3026db543216SSean Christopherson 30278ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 30288ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 3029a8ac499bSSean Christopherson int max_level) 30301b6d9d9eSSean Christopherson { 30311b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3032ec607a56SPaolo Bonzini int host_level; 30331b6d9d9eSSean Christopherson 30341b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 30351b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 30361b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 30371b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 30381b6d9d9eSSean Christopherson break; 30391b6d9d9eSSean Christopherson } 30401b6d9d9eSSean Christopherson 30411b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 30421b6d9d9eSSean Christopherson return PG_LEVEL_4K; 30431b6d9d9eSSean Christopherson 3044a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3045ec607a56SPaolo Bonzini return min(host_level, max_level); 30461b6d9d9eSSean Christopherson } 30471b6d9d9eSSean Christopherson 304873a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 30490885904dSSean Christopherson { 3050e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 305117eff019SSean Christopherson kvm_pfn_t mask; 30520885904dSSean Christopherson 305373a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 30543cf06612SSean Christopherson 305573a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 305673a3c659SPaolo Bonzini return; 305717eff019SSean Christopherson 30585d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 305973a3c659SPaolo Bonzini return; 306017eff019SSean Christopherson 3061e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 306273a3c659SPaolo Bonzini return; 3063293e306eSSean Christopherson 30643cf06612SSean Christopherson /* 30653cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 30663cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 30673cf06612SSean Christopherson */ 306873a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 3069a8ac499bSSean Christopherson fault->gfn, fault->max_level); 307073a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 307173a3c659SPaolo Bonzini return; 30724cd071d1SSean Christopherson 30730885904dSSean Christopherson /* 307420ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 30754cd071d1SSean Christopherson * the pmd can't be split from under us. 30760885904dSSean Christopherson */ 307773a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 307873a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 307973a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 308073a3c659SPaolo Bonzini fault->pfn &= ~mask; 30810885904dSSean Christopherson } 30820885904dSSean Christopherson 3083536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3084c50d8ae3SPaolo Bonzini { 3085536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3086536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3087c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 3088c50d8ae3SPaolo Bonzini !is_large_pte(spte)) { 3089c50d8ae3SPaolo Bonzini /* 3090c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 3091c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 3092c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 3093c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 3094c50d8ae3SPaolo Bonzini * the address. 3095c50d8ae3SPaolo Bonzini */ 3096536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3097536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3098536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3099536f0e6aSPaolo Bonzini fault->goal_level--; 3100c50d8ae3SPaolo Bonzini } 3101c50d8ae3SPaolo Bonzini } 3102c50d8ae3SPaolo Bonzini 310343b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3104c50d8ae3SPaolo Bonzini { 3105c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3106c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 310773a3c659SPaolo Bonzini int ret; 310843b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3109c50d8ae3SPaolo Bonzini 311073a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 31114cd071d1SSean Christopherson 3112f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 311343b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3114c50d8ae3SPaolo Bonzini /* 3115c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3116c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3117c50d8ae3SPaolo Bonzini */ 311873a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3119536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3120c50d8ae3SPaolo Bonzini 312143b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 312273a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3123c50d8ae3SPaolo Bonzini break; 3124c50d8ae3SPaolo Bonzini 31252e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 31260cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 31270cd8dc73SPaolo Bonzini continue; 3128c50d8ae3SPaolo Bonzini 3129c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 313073a3c659SPaolo Bonzini if (fault->is_tdp && fault->huge_page_disallowed && 313173a3c659SPaolo Bonzini fault->req_level >= it.level) 3132c50d8ae3SPaolo Bonzini account_huge_nx_page(vcpu->kvm, sp); 3133c50d8ae3SPaolo Bonzini } 3134c50d8ae3SPaolo Bonzini 3135b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3136b1a429fbSSean Christopherson return -EFAULT; 3137b1a429fbSSean Christopherson 31388a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3139a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 314012703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 314112703759SSean Christopherson return ret; 314212703759SSean Christopherson 3143c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3144c50d8ae3SPaolo Bonzini return ret; 3145c50d8ae3SPaolo Bonzini } 3146c50d8ae3SPaolo Bonzini 3147c50d8ae3SPaolo Bonzini static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) 3148c50d8ae3SPaolo Bonzini { 3149c50d8ae3SPaolo Bonzini send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk); 3150c50d8ae3SPaolo Bonzini } 3151c50d8ae3SPaolo Bonzini 3152*76657687SPeter Xu static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) 3153c50d8ae3SPaolo Bonzini { 3154*76657687SPeter Xu if (is_sigpending_pfn(pfn)) { 3155*76657687SPeter Xu kvm_handle_signal_exit(vcpu); 3156*76657687SPeter Xu return -EINTR; 3157*76657687SPeter Xu } 3158*76657687SPeter Xu 3159c50d8ae3SPaolo Bonzini /* 3160c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3161c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3162c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3163c50d8ae3SPaolo Bonzini */ 3164c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_RO_FAULT) 3165c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3166c50d8ae3SPaolo Bonzini 3167c50d8ae3SPaolo Bonzini if (pfn == KVM_PFN_ERR_HWPOISON) { 3168c50d8ae3SPaolo Bonzini kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); 3169c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3170c50d8ae3SPaolo Bonzini } 3171c50d8ae3SPaolo Bonzini 3172c50d8ae3SPaolo Bonzini return -EFAULT; 3173c50d8ae3SPaolo Bonzini } 3174c50d8ae3SPaolo Bonzini 31755276c616SSean Christopherson static int handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 31765276c616SSean Christopherson unsigned int access) 3177c50d8ae3SPaolo Bonzini { 3178c50d8ae3SPaolo Bonzini /* The pfn is invalid, report the error! */ 31795276c616SSean Christopherson if (unlikely(is_error_pfn(fault->pfn))) 3180*76657687SPeter Xu return kvm_handle_error_pfn(vcpu, fault->gfn, fault->pfn); 3181c50d8ae3SPaolo Bonzini 3182e710c5f6SDavid Matlack if (unlikely(!fault->slot)) { 31833a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 31843a13f4feSPaolo Bonzini 31853a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3186c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 318730ab5901SSean Christopherson /* 318830ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 318930ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 319086931ff7SSean Christopherson * MMIO SPTE will just be an expensive nop. Do not cache MMIO 319186931ff7SSean Christopherson * whose gfn is greater than host.MAXPHYADDR, any guest that 319286931ff7SSean Christopherson * generates such gfns is running nested and is being tricked 319386931ff7SSean Christopherson * by L0 userspace (you can observe gfn > L1.MAXPHYADDR if 319486931ff7SSean Christopherson * and only if L1's MAXPHYADDR is inaccurate with respect to 319586931ff7SSean Christopherson * the hardware's). 319630ab5901SSean Christopherson */ 31978b9e74bfSSean Christopherson if (unlikely(!enable_mmio_caching) || 31985276c616SSean Christopherson unlikely(fault->gfn > kvm_mmu_max_gfn())) 31995276c616SSean Christopherson return RET_PF_EMULATE; 320030ab5901SSean Christopherson } 3201c50d8ae3SPaolo Bonzini 32025276c616SSean Christopherson return RET_PF_CONTINUE; 3203c50d8ae3SPaolo Bonzini } 3204c50d8ae3SPaolo Bonzini 32053c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3206c50d8ae3SPaolo Bonzini { 3207c50d8ae3SPaolo Bonzini /* 32085c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 32095c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 32105c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 32115c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3212c50d8ae3SPaolo Bonzini */ 32133c8ad5a6SPaolo Bonzini if (fault->rsvd) 3214c50d8ae3SPaolo Bonzini return false; 3215c50d8ae3SPaolo Bonzini 3216c50d8ae3SPaolo Bonzini /* 3217c50d8ae3SPaolo Bonzini * #PF can be fast if: 3218c50d8ae3SPaolo Bonzini * 321954275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 322054275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 322154275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 322254275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 322354275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 322454275f74SSean Christopherson * mechanism only supports direct MMUs. 322554275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 322654275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 322754275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 322854275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 322954275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3230c50d8ae3SPaolo Bonzini */ 32315c64aba5SSean Christopherson if (!fault->present) 32325c64aba5SSean Christopherson return !kvm_ad_enabled(); 32335c64aba5SSean Christopherson 32345c64aba5SSean Christopherson /* 32355c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 32365c64aba5SSean Christopherson * the "exec" flag. 32375c64aba5SSean Christopherson */ 32385c64aba5SSean Christopherson return fault->write; 3239c50d8ae3SPaolo Bonzini } 3240c50d8ae3SPaolo Bonzini 3241c50d8ae3SPaolo Bonzini /* 3242c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3243c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3244c50d8ae3SPaolo Bonzini */ 3245c50d8ae3SPaolo Bonzini static bool 3246e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3247c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3248c50d8ae3SPaolo Bonzini { 3249c50d8ae3SPaolo Bonzini /* 3250c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3251c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3252c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3253c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3254c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3255c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3256c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3257c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3258c50d8ae3SPaolo Bonzini * 3259c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3260c50d8ae3SPaolo Bonzini */ 32612db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3262c50d8ae3SPaolo Bonzini return false; 3263c50d8ae3SPaolo Bonzini 3264e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3265e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3266c50d8ae3SPaolo Bonzini 3267c50d8ae3SPaolo Bonzini return true; 3268c50d8ae3SPaolo Bonzini } 3269c50d8ae3SPaolo Bonzini 32703c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3271c50d8ae3SPaolo Bonzini { 32723c8ad5a6SPaolo Bonzini if (fault->exec) 3273c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3274c50d8ae3SPaolo Bonzini 32753c8ad5a6SPaolo Bonzini if (fault->write) 3276c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3277c50d8ae3SPaolo Bonzini 3278c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3279c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3280c50d8ae3SPaolo Bonzini } 3281c50d8ae3SPaolo Bonzini 3282c50d8ae3SPaolo Bonzini /* 32836e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 32846e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 32856e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 32866e8eb206SDavid Matlack * 32876e8eb206SDavid Matlack * Contract: 32886e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 32896e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 32906e8eb206SDavid Matlack */ 32916e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 32926e8eb206SDavid Matlack { 32936e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 32946e8eb206SDavid Matlack u64 old_spte; 32956e8eb206SDavid Matlack u64 *sptep = NULL; 32966e8eb206SDavid Matlack 32976e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 32986e8eb206SDavid Matlack sptep = iterator.sptep; 32996e8eb206SDavid Matlack *spte = old_spte; 33006e8eb206SDavid Matlack } 33016e8eb206SDavid Matlack 33026e8eb206SDavid Matlack return sptep; 33036e8eb206SDavid Matlack } 33046e8eb206SDavid Matlack 33056e8eb206SDavid Matlack /* 3306c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3307c50d8ae3SPaolo Bonzini */ 33083c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3309c50d8ae3SPaolo Bonzini { 3310c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3311c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3312c50d8ae3SPaolo Bonzini u64 spte = 0ull; 33136e8eb206SDavid Matlack u64 *sptep = NULL; 3314c50d8ae3SPaolo Bonzini uint retry_count = 0; 3315c50d8ae3SPaolo Bonzini 33163c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3317c4371c2aSSean Christopherson return ret; 3318c50d8ae3SPaolo Bonzini 3319c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3320c50d8ae3SPaolo Bonzini 3321c50d8ae3SPaolo Bonzini do { 3322c50d8ae3SPaolo Bonzini u64 new_spte; 3323c50d8ae3SPaolo Bonzini 33246e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 33253c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 33266e8eb206SDavid Matlack else 33273c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3328c50d8ae3SPaolo Bonzini 3329ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3330ec89e643SSean Christopherson break; 3331ec89e643SSean Christopherson 33326e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3333c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3334c50d8ae3SPaolo Bonzini break; 3335c50d8ae3SPaolo Bonzini 3336c50d8ae3SPaolo Bonzini /* 3337c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3338c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3339c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3340c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3341c50d8ae3SPaolo Bonzini * current CPU took the fault. 3342c50d8ae3SPaolo Bonzini * 3343c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3344c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3345c50d8ae3SPaolo Bonzini */ 33463c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3347c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3348c50d8ae3SPaolo Bonzini break; 3349c50d8ae3SPaolo Bonzini } 3350c50d8ae3SPaolo Bonzini 3351c50d8ae3SPaolo Bonzini new_spte = spte; 3352c50d8ae3SPaolo Bonzini 335354275f74SSean Christopherson /* 335454275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 335554275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 335654275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 335754275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 335854275f74SSean Christopherson */ 335954275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3360c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3361c50d8ae3SPaolo Bonzini 3362c50d8ae3SPaolo Bonzini /* 336354275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 336454275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 336554275f74SSean Christopherson * that were write-protected for dirty-logging or access 336654275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 336754275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 336854275f74SSean Christopherson * The is_access_allowed() check above handles the common case 336954275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 337054275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 337154275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3372c50d8ae3SPaolo Bonzini */ 3373706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3374c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3375c50d8ae3SPaolo Bonzini 3376c50d8ae3SPaolo Bonzini /* 337710c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 337810c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 337910c30de0SJunaid Shahid * first page into the dirty-bitmap in 3380c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3381c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3382c50d8ae3SPaolo Bonzini * 3383c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3384c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3385c50d8ae3SPaolo Bonzini */ 338610c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 338710c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3388c50d8ae3SPaolo Bonzini break; 3389c50d8ae3SPaolo Bonzini } 3390c50d8ae3SPaolo Bonzini 3391c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3392c50d8ae3SPaolo Bonzini if (new_spte == spte || 33933c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3394c50d8ae3SPaolo Bonzini break; 3395c50d8ae3SPaolo Bonzini 3396c50d8ae3SPaolo Bonzini /* 3397c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3398c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 33993ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3400c50d8ae3SPaolo Bonzini */ 3401e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3402c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3403c50d8ae3SPaolo Bonzini break; 3404c4371c2aSSean Christopherson } 3405c50d8ae3SPaolo Bonzini 3406c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3407c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3408c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3409c50d8ae3SPaolo Bonzini break; 3410c50d8ae3SPaolo Bonzini } 3411c50d8ae3SPaolo Bonzini 3412c50d8ae3SPaolo Bonzini } while (true); 3413c50d8ae3SPaolo Bonzini 3414f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3415c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3416c50d8ae3SPaolo Bonzini 34171075d41eSSean Christopherson if (ret != RET_PF_INVALID) 34181075d41eSSean Christopherson vcpu->stat.pf_fast++; 34191075d41eSSean Christopherson 3420c4371c2aSSean Christopherson return ret; 3421c50d8ae3SPaolo Bonzini } 3422c50d8ae3SPaolo Bonzini 3423c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3424c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3425c50d8ae3SPaolo Bonzini { 3426c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3427c50d8ae3SPaolo Bonzini 3428c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3429c50d8ae3SPaolo Bonzini return; 3430c50d8ae3SPaolo Bonzini 34312ca3129eSSean Christopherson sp = to_shadow_page(*root_hpa & SPTE_BASE_ADDR_MASK); 34329191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 34339191b8f0SPaolo Bonzini return; 343402c00b3aSBen Gardon 3435897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 34366103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 343776eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3438c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3439c50d8ae3SPaolo Bonzini 3440c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3441c50d8ae3SPaolo Bonzini } 3442c50d8ae3SPaolo Bonzini 3443c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 34440c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3445c50d8ae3SPaolo Bonzini ulong roots_to_free) 3446c50d8ae3SPaolo Bonzini { 3447c50d8ae3SPaolo Bonzini int i; 3448c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3449594bef79SPaolo Bonzini bool free_active_root; 3450c50d8ae3SPaolo Bonzini 3451c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3452c50d8ae3SPaolo Bonzini 3453c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3454594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3455594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3456594bef79SPaolo Bonzini 3457594bef79SPaolo Bonzini if (!free_active_root) { 3458c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3459c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3460c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3461c50d8ae3SPaolo Bonzini break; 3462c50d8ae3SPaolo Bonzini 3463c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3464c50d8ae3SPaolo Bonzini return; 3465c50d8ae3SPaolo Bonzini } 3466c50d8ae3SPaolo Bonzini 3467531810caSBen Gardon write_lock(&kvm->mmu_lock); 3468c50d8ae3SPaolo Bonzini 3469c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3470c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 34714d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3472c50d8ae3SPaolo Bonzini &invalid_list); 3473c50d8ae3SPaolo Bonzini 3474c50d8ae3SPaolo Bonzini if (free_active_root) { 3475594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3476b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 347704d45551SSean Christopherson } else if (mmu->pae_root) { 3478c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3479c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3480c834e5e4SSean Christopherson continue; 3481c834e5e4SSean Christopherson 3482c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3483c50d8ae3SPaolo Bonzini &invalid_list); 3484c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3485c50d8ae3SPaolo Bonzini } 3486c50d8ae3SPaolo Bonzini } 3487b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3488b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3489c50d8ae3SPaolo Bonzini } 3490c50d8ae3SPaolo Bonzini 34914d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3492531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3493c50d8ae3SPaolo Bonzini } 3494c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3495c50d8ae3SPaolo Bonzini 34960c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 349725b62c62SSean Christopherson { 349825b62c62SSean Christopherson unsigned long roots_to_free = 0; 349925b62c62SSean Christopherson hpa_t root_hpa; 350025b62c62SSean Christopherson int i; 350125b62c62SSean Christopherson 350225b62c62SSean Christopherson /* 350325b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 350425b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 350525b62c62SSean Christopherson */ 35067a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 350725b62c62SSean Christopherson 350825b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 350925b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 351025b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 351125b62c62SSean Christopherson continue; 351225b62c62SSean Christopherson 351325b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 351425b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 351525b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 351625b62c62SSean Christopherson } 351725b62c62SSean Christopherson 35180c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 351925b62c62SSean Christopherson } 352025b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 352125b62c62SSean Christopherson 352225b62c62SSean Christopherson 3523c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3524c50d8ae3SPaolo Bonzini { 3525c50d8ae3SPaolo Bonzini int ret = 0; 3526c50d8ae3SPaolo Bonzini 3527995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3528c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3529c50d8ae3SPaolo Bonzini ret = 1; 3530c50d8ae3SPaolo Bonzini } 3531c50d8ae3SPaolo Bonzini 3532c50d8ae3SPaolo Bonzini return ret; 3533c50d8ae3SPaolo Bonzini } 3534c50d8ae3SPaolo Bonzini 35352e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 353686938ab6SDavid Matlack u8 level) 3537c50d8ae3SPaolo Bonzini { 35382e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3539c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 35408123f265SSean Christopherson 35412e65e842SDavid Matlack role.level = level; 35422e65e842SDavid Matlack role.quadrant = quadrant; 35432e65e842SDavid Matlack 35447f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 35457f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 35467f497775SDavid Matlack 354787654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 35488123f265SSean Christopherson ++sp->root_count; 35498123f265SSean Christopherson 35508123f265SSean Christopherson return __pa(sp->spt); 35518123f265SSean Christopherson } 35528123f265SSean Christopherson 35538123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 35548123f265SSean Christopherson { 3555b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3556a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 35578123f265SSean Christopherson hpa_t root; 3558c50d8ae3SPaolo Bonzini unsigned i; 35594a38162eSPaolo Bonzini int r; 35604a38162eSPaolo Bonzini 35614a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 35624a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 35634a38162eSPaolo Bonzini if (r < 0) 35644a38162eSPaolo Bonzini goto out_unlock; 3565c50d8ae3SPaolo Bonzini 3566897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(vcpu->kvm)) { 356702c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3568b9e5603cSPaolo Bonzini mmu->root.hpa = root; 356902c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 357086938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3571b9e5603cSPaolo Bonzini mmu->root.hpa = root; 35728123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 35734a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 35744a38162eSPaolo Bonzini r = -EIO; 35754a38162eSPaolo Bonzini goto out_unlock; 35764a38162eSPaolo Bonzini } 357773ad1606SSean Christopherson 3578c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3579c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3580c50d8ae3SPaolo Bonzini 35817f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 35822e65e842SDavid Matlack PT32_ROOT_LEVEL); 358317e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3584d2263de1SYuan Yao shadow_me_value; 3585c50d8ae3SPaolo Bonzini } 3586b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 358773ad1606SSean Christopherson } else { 358873ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 35894a38162eSPaolo Bonzini r = -EIO; 35904a38162eSPaolo Bonzini goto out_unlock; 359173ad1606SSean Christopherson } 35923651c7fcSSean Christopherson 3593b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3594b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 35954a38162eSPaolo Bonzini out_unlock: 35964a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 35974a38162eSPaolo Bonzini return r; 3598c50d8ae3SPaolo Bonzini } 3599c50d8ae3SPaolo Bonzini 36001e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 36011e76a3ceSDavid Stevens { 36021e76a3ceSDavid Stevens struct kvm_memslots *slots; 36031e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3604a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 36051e76a3ceSDavid Stevens 36061e76a3ceSDavid Stevens /* 36071e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 36081e76a3ceSDavid Stevens * taking the lock. 36091e76a3ceSDavid Stevens */ 36101e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 36111e76a3ceSDavid Stevens return 0; 36121e76a3ceSDavid Stevens 36131e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 36141e76a3ceSDavid Stevens 36151e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 36161e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 36171e76a3ceSDavid Stevens goto out_unlock; 36181e76a3ceSDavid Stevens 36191e76a3ceSDavid Stevens /* 36201e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 36211e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 36221e76a3ceSDavid Stevens */ 36231e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 36241e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 36251e76a3ceSDavid Stevens goto out_success; 36261e76a3ceSDavid Stevens 36271e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 36281e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3629a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 36301e76a3ceSDavid Stevens /* 36311e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 36321e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 36331e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 36341e76a3ceSDavid Stevens * failure to avoid having to track which allocations 36351e76a3ceSDavid Stevens * were made now versus when the memslot was created. 36361e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 36371e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 36381e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 36391e76a3ceSDavid Stevens */ 36401e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 36411e76a3ceSDavid Stevens if (r) 36421e76a3ceSDavid Stevens goto out_unlock; 36431e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 36441e76a3ceSDavid Stevens if (r) 36451e76a3ceSDavid Stevens goto out_unlock; 36461e76a3ceSDavid Stevens } 36471e76a3ceSDavid Stevens } 36481e76a3ceSDavid Stevens 36491e76a3ceSDavid Stevens /* 36501e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 36511e76a3ceSDavid Stevens * all the related pointers are set. 36521e76a3ceSDavid Stevens */ 36531e76a3ceSDavid Stevens out_success: 36541e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 36551e76a3ceSDavid Stevens 36561e76a3ceSDavid Stevens out_unlock: 36571e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 36581e76a3ceSDavid Stevens return r; 36591e76a3ceSDavid Stevens } 36601e76a3ceSDavid Stevens 3661c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3662c50d8ae3SPaolo Bonzini { 3663b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 36646e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3665be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 36667f497775SDavid Matlack int quadrant, i, r; 36678123f265SSean Christopherson hpa_t root; 3668c50d8ae3SPaolo Bonzini 3669b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3670be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3671c50d8ae3SPaolo Bonzini 3672c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3673c50d8ae3SPaolo Bonzini return 1; 3674c50d8ae3SPaolo Bonzini 3675c50d8ae3SPaolo Bonzini /* 36764a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 36774a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 36784a38162eSPaolo Bonzini */ 36794d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 36806e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 36816e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 36826e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 36836e0918aeSSean Christopherson continue; 36846e0918aeSSean Christopherson 36856e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 36866e0918aeSSean Christopherson return 1; 36876e0918aeSSean Christopherson } 36886e0918aeSSean Christopherson } 36896e0918aeSSean Christopherson 36901e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3691d501f747SBen Gardon if (r) 3692d501f747SBen Gardon return r; 3693d501f747SBen Gardon 36944a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36954a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36964a38162eSPaolo Bonzini if (r < 0) 36974a38162eSPaolo Bonzini goto out_unlock; 36984a38162eSPaolo Bonzini 3699c50d8ae3SPaolo Bonzini /* 3700c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3701c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3702c50d8ae3SPaolo Bonzini */ 37034d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 37048123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 370586938ab6SDavid Matlack mmu->root_role.level); 3706b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3707be01e8e2SSean Christopherson goto set_root_pgd; 3708c50d8ae3SPaolo Bonzini } 3709c50d8ae3SPaolo Bonzini 37104a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 37114a38162eSPaolo Bonzini r = -EIO; 37124a38162eSPaolo Bonzini goto out_unlock; 37134a38162eSPaolo Bonzini } 371473ad1606SSean Christopherson 3715c50d8ae3SPaolo Bonzini /* 3716c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3717c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3718c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3719c50d8ae3SPaolo Bonzini */ 3720e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3721a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3722c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3723c50d8ae3SPaolo Bonzini 372403ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 37254a38162eSPaolo Bonzini r = -EIO; 37264a38162eSPaolo Bonzini goto out_unlock; 37274a38162eSPaolo Bonzini } 372803ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3729cb0f722aSWei Huang 3730a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3731cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3732cb0f722aSWei Huang r = -EIO; 3733cb0f722aSWei Huang goto out_unlock; 3734cb0f722aSWei Huang } 3735cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3736cb0f722aSWei Huang } 373704d45551SSean Christopherson } 373804d45551SSean Christopherson 3739c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3740c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 37416e6ec584SSean Christopherson 37424d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 37436e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3744c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3745c50d8ae3SPaolo Bonzini continue; 3746c50d8ae3SPaolo Bonzini } 37476e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3748c50d8ae3SPaolo Bonzini } 3749c50d8ae3SPaolo Bonzini 37507f497775SDavid Matlack /* 37517f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 37527f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 37537f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 37547f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 37557f497775SDavid Matlack */ 37567f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 37577f497775SDavid Matlack 37587f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3759b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3760c50d8ae3SPaolo Bonzini } 3761c50d8ae3SPaolo Bonzini 3762a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3763b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3764a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3765b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3766ba0a194fSSean Christopherson else 3767b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3768c50d8ae3SPaolo Bonzini 3769be01e8e2SSean Christopherson set_root_pgd: 3770b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 37714a38162eSPaolo Bonzini out_unlock: 37724a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3773c50d8ae3SPaolo Bonzini 3774c6c937d6SLike Xu return r; 3775c50d8ae3SPaolo Bonzini } 3776c50d8ae3SPaolo Bonzini 3777748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3778c50d8ae3SPaolo Bonzini { 3779748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3780a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3781cb0f722aSWei Huang u64 *pml5_root = NULL; 3782cb0f722aSWei Huang u64 *pml4_root = NULL; 3783cb0f722aSWei Huang u64 *pae_root; 3784748e52b9SSean Christopherson 3785748e52b9SSean Christopherson /* 3786748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3787748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3788748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3789748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3790748e52b9SSean Christopherson */ 3791347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3792347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3793a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3794748e52b9SSean Christopherson return 0; 3795748e52b9SSean Christopherson 3796a717a780SSean Christopherson /* 3797a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3798a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3799a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3800a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3801a717a780SSean Christopherson * prior MMU would also have required pml5. 3802a717a780SSean Christopherson */ 3803a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3804748e52b9SSean Christopherson return 0; 3805748e52b9SSean Christopherson 3806748e52b9SSean Christopherson /* 3807748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3808748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3809748e52b9SSean Christopherson */ 3810cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3811a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3812748e52b9SSean Christopherson return -EIO; 3813748e52b9SSean Christopherson 38144a98623dSSean Christopherson /* 38154a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 38164a98623dSSean Christopherson * doesn't need to be decrypted. 38174a98623dSSean Christopherson */ 3818748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3819748e52b9SSean Christopherson if (!pae_root) 3820748e52b9SSean Christopherson return -ENOMEM; 3821748e52b9SSean Christopherson 3822cb0f722aSWei Huang #ifdef CONFIG_X86_64 382303ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3824cb0f722aSWei Huang if (!pml4_root) 3825cb0f722aSWei Huang goto err_pml4; 3826cb0f722aSWei Huang 3827a717a780SSean Christopherson if (need_pml5) { 3828cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3829cb0f722aSWei Huang if (!pml5_root) 3830cb0f722aSWei Huang goto err_pml5; 3831748e52b9SSean Christopherson } 3832cb0f722aSWei Huang #endif 3833748e52b9SSean Christopherson 3834748e52b9SSean Christopherson mmu->pae_root = pae_root; 383503ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3836cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3837748e52b9SSean Christopherson 3838748e52b9SSean Christopherson return 0; 3839cb0f722aSWei Huang 3840cb0f722aSWei Huang #ifdef CONFIG_X86_64 3841cb0f722aSWei Huang err_pml5: 3842cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3843cb0f722aSWei Huang err_pml4: 3844cb0f722aSWei Huang free_page((unsigned long)pae_root); 3845cb0f722aSWei Huang return -ENOMEM; 3846cb0f722aSWei Huang #endif 3847c50d8ae3SPaolo Bonzini } 3848c50d8ae3SPaolo Bonzini 3849264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3850264d3dc1SLai Jiangshan { 3851264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3852264d3dc1SLai Jiangshan 385361b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 385461b05a9fSLai Jiangshan return false; 385561b05a9fSLai Jiangshan 3856264d3dc1SLai Jiangshan /* 3857264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3858264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3859264d3dc1SLai Jiangshan * 3860264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3861264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3862264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3863264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3864264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3865264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3866264d3dc1SLai Jiangshan * requirement isn't satisfied. 3867264d3dc1SLai Jiangshan */ 3868264d3dc1SLai Jiangshan smp_rmb(); 3869264d3dc1SLai Jiangshan sp = to_shadow_page(root); 38705d6a3221SSean Christopherson 38715d6a3221SSean Christopherson /* 38725d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 38735d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 38745d6a3221SSean Christopherson */ 38755d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 38765d6a3221SSean Christopherson return false; 38775d6a3221SSean Christopherson 3878264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3879264d3dc1SLai Jiangshan return true; 3880264d3dc1SLai Jiangshan 3881264d3dc1SLai Jiangshan return false; 3882264d3dc1SLai Jiangshan } 3883264d3dc1SLai Jiangshan 3884c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3885c50d8ae3SPaolo Bonzini { 3886c50d8ae3SPaolo Bonzini int i; 3887c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3888c50d8ae3SPaolo Bonzini 3889347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3890c50d8ae3SPaolo Bonzini return; 3891c50d8ae3SPaolo Bonzini 3892b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3893c50d8ae3SPaolo Bonzini return; 3894c50d8ae3SPaolo Bonzini 3895c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3896c50d8ae3SPaolo Bonzini 38974d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3898b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3899e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3900c50d8ae3SPaolo Bonzini 3901264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3902c50d8ae3SPaolo Bonzini return; 3903c50d8ae3SPaolo Bonzini 3904531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 390565855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3906531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3907c50d8ae3SPaolo Bonzini return; 3908c50d8ae3SPaolo Bonzini } 3909c50d8ae3SPaolo Bonzini 3910531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3911c50d8ae3SPaolo Bonzini 3912c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3913c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3914c50d8ae3SPaolo Bonzini 3915c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 39162ca3129eSSean Christopherson root &= SPTE_BASE_ADDR_MASK; 3917e47c4aeeSSean Christopherson sp = to_shadow_page(root); 391865855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3919c50d8ae3SPaolo Bonzini } 3920c50d8ae3SPaolo Bonzini } 3921c50d8ae3SPaolo Bonzini 3922531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3923c50d8ae3SPaolo Bonzini } 3924c50d8ae3SPaolo Bonzini 392561b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 392661b05a9fSLai Jiangshan { 392761b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 392861b05a9fSLai Jiangshan int i; 392961b05a9fSLai Jiangshan 393061b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 393161b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 393261b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 393361b05a9fSLai Jiangshan 393461b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 39350c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 393661b05a9fSLai Jiangshan } 393761b05a9fSLai Jiangshan 39381f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 39395b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3940c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3941c50d8ae3SPaolo Bonzini { 3942c50d8ae3SPaolo Bonzini if (exception) 3943c50d8ae3SPaolo Bonzini exception->error_code = 0; 3944c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3945c50d8ae3SPaolo Bonzini } 3946c50d8ae3SPaolo Bonzini 3947c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3948c50d8ae3SPaolo Bonzini { 3949c50d8ae3SPaolo Bonzini /* 3950c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 3951c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 3952c50d8ae3SPaolo Bonzini */ 3953c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 3954c50d8ae3SPaolo Bonzini return false; 3955c50d8ae3SPaolo Bonzini 3956c50d8ae3SPaolo Bonzini if (direct) 3957c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 3958c50d8ae3SPaolo Bonzini 3959c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 3960c50d8ae3SPaolo Bonzini } 3961c50d8ae3SPaolo Bonzini 396295fb5b02SBen Gardon /* 396395fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 396495fb5b02SBen Gardon * That SPTE may be non-present. 3965c5c8c7c5SDavid Matlack * 3966c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 396795fb5b02SBen Gardon */ 396839b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 3969c50d8ae3SPaolo Bonzini { 3970c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 39712aa07893SSean Christopherson int leaf = -1; 397295fb5b02SBen Gardon u64 spte; 3973c50d8ae3SPaolo Bonzini 397439b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 397539b4d43eSSean Christopherson *root_level = iterator.level; 3976c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 3977c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 397895fb5b02SBen Gardon leaf = iterator.level; 3979c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 3980c50d8ae3SPaolo Bonzini 3981dde81f94SSean Christopherson sptes[leaf] = spte; 398295fb5b02SBen Gardon } 398395fb5b02SBen Gardon 398495fb5b02SBen Gardon return leaf; 398595fb5b02SBen Gardon } 398695fb5b02SBen Gardon 39879aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 398895fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 398995fb5b02SBen Gardon { 3990dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 399195fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 399239b4d43eSSean Christopherson int root, leaf, level; 399395fb5b02SBen Gardon bool reserved = false; 399495fb5b02SBen Gardon 3995c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 3996c5c8c7c5SDavid Matlack 399763c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 399839b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 399995fb5b02SBen Gardon else 400039b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 400195fb5b02SBen Gardon 4002c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 4003c5c8c7c5SDavid Matlack 40042aa07893SSean Christopherson if (unlikely(leaf < 0)) { 40052aa07893SSean Christopherson *sptep = 0ull; 40062aa07893SSean Christopherson return reserved; 40072aa07893SSean Christopherson } 40082aa07893SSean Christopherson 40099aa41879SSean Christopherson *sptep = sptes[leaf]; 40109aa41879SSean Christopherson 40119aa41879SSean Christopherson /* 40129aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 40139aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 40149aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 40159aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 40169aa41879SSean Christopherson */ 40179aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 40189aa41879SSean Christopherson leaf++; 401995fb5b02SBen Gardon 402095fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 402195fb5b02SBen Gardon 40229aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4023961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4024c50d8ae3SPaolo Bonzini 4025c50d8ae3SPaolo Bonzini if (reserved) { 4026bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4027c50d8ae3SPaolo Bonzini __func__, addr); 402895fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4029bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4030bb4cdf3aSSean Christopherson sptes[level], level, 4031961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4032c50d8ae3SPaolo Bonzini } 4033ddce6208SSean Christopherson 4034c50d8ae3SPaolo Bonzini return reserved; 4035c50d8ae3SPaolo Bonzini } 4036c50d8ae3SPaolo Bonzini 4037c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4038c50d8ae3SPaolo Bonzini { 4039c50d8ae3SPaolo Bonzini u64 spte; 4040c50d8ae3SPaolo Bonzini bool reserved; 4041c50d8ae3SPaolo Bonzini 4042c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4043c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4044c50d8ae3SPaolo Bonzini 404595fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 4046c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 4047c50d8ae3SPaolo Bonzini return -EINVAL; 4048c50d8ae3SPaolo Bonzini 4049c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4050c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 40510a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4052c50d8ae3SPaolo Bonzini 4053c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4054c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4055c50d8ae3SPaolo Bonzini 4056c50d8ae3SPaolo Bonzini if (direct) 4057c50d8ae3SPaolo Bonzini addr = 0; 4058c50d8ae3SPaolo Bonzini 4059c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4060c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4061c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4062c50d8ae3SPaolo Bonzini } 4063c50d8ae3SPaolo Bonzini 4064c50d8ae3SPaolo Bonzini /* 4065c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4066c50d8ae3SPaolo Bonzini * the address. 4067c50d8ae3SPaolo Bonzini */ 4068c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4069c50d8ae3SPaolo Bonzini } 4070c50d8ae3SPaolo Bonzini 4071c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4072b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4073c50d8ae3SPaolo Bonzini { 4074b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4075c50d8ae3SPaolo Bonzini return false; 4076c50d8ae3SPaolo Bonzini 4077b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4078c50d8ae3SPaolo Bonzini return false; 4079c50d8ae3SPaolo Bonzini 4080c50d8ae3SPaolo Bonzini /* 4081c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4082c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4083c50d8ae3SPaolo Bonzini */ 40849d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 4085c50d8ae3SPaolo Bonzini return true; 4086c50d8ae3SPaolo Bonzini 4087c50d8ae3SPaolo Bonzini return false; 4088c50d8ae3SPaolo Bonzini } 4089c50d8ae3SPaolo Bonzini 4090c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4091c50d8ae3SPaolo Bonzini { 4092c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4093c50d8ae3SPaolo Bonzini u64 spte; 4094c50d8ae3SPaolo Bonzini 4095c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 40963e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4097c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4098c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4099c50d8ae3SPaolo Bonzini } 4100c50d8ae3SPaolo Bonzini 41016f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 41026f3c1fc5SLiang Zhang { 41036f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 41046f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 41056f3c1fc5SLiang Zhang 41066f3c1fc5SLiang Zhang if (id << 12 == 0) 41076f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 41086f3c1fc5SLiang Zhang 41096f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 41106f3c1fc5SLiang Zhang } 41116f3c1fc5SLiang Zhang 4112e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 41139f1a8526SSean Christopherson gfn_t gfn) 4114c50d8ae3SPaolo Bonzini { 4115c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4116c50d8ae3SPaolo Bonzini 41176f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4118c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4119347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 4120d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 4121c50d8ae3SPaolo Bonzini 41229f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 41239f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4124c50d8ae3SPaolo Bonzini } 4125c50d8ae3SPaolo Bonzini 41268a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 41278a009d5bSSean Christopherson { 41288a009d5bSSean Christopherson int r; 41298a009d5bSSean Christopherson 41308a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 41318a009d5bSSean Christopherson work->wakeup_all) 41328a009d5bSSean Christopherson return; 41338a009d5bSSean Christopherson 41348a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 41358a009d5bSSean Christopherson if (unlikely(r)) 41368a009d5bSSean Christopherson return; 41378a009d5bSSean Christopherson 41388a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 41398a009d5bSSean Christopherson work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu)) 41408a009d5bSSean Christopherson return; 41418a009d5bSSean Christopherson 41428a009d5bSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true); 41438a009d5bSSean Christopherson } 41448a009d5bSSean Christopherson 41455276c616SSean Christopherson static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4146c50d8ae3SPaolo Bonzini { 4147e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4148c50d8ae3SPaolo Bonzini bool async; 4149c50d8ae3SPaolo Bonzini 4150e0c37868SSean Christopherson /* 4151e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4152e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4153e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4154e0c37868SSean Christopherson */ 4155e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 41565276c616SSean Christopherson return RET_PF_RETRY; 4157e0c37868SSean Christopherson 41589cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4159c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 41609cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4161e710c5f6SDavid Matlack fault->slot = NULL; 41623647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 41633647cd04SPaolo Bonzini fault->map_writable = false; 41645276c616SSean Christopherson return RET_PF_CONTINUE; 4165c50d8ae3SPaolo Bonzini } 41669cc13d60SMaxim Levitsky /* 41679cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 41689cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 41699cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 41709cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 41719cc13d60SMaxim Levitsky */ 41729cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 41735276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 41745276c616SSean Christopherson return RET_PF_EMULATE; 41759cc13d60SMaxim Levitsky } 4176c50d8ae3SPaolo Bonzini 4177c50d8ae3SPaolo Bonzini async = false; 4178c8b88b33SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, 41793647cd04SPaolo Bonzini fault->write, &fault->map_writable, 41803647cd04SPaolo Bonzini &fault->hva); 4181c50d8ae3SPaolo Bonzini if (!async) 41825276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4183c50d8ae3SPaolo Bonzini 41842839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 41853647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 41863647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 41871685c0f3SMingwei Zhang trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4188c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 41895276c616SSean Christopherson return RET_PF_RETRY; 41905276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 41915276c616SSean Christopherson return RET_PF_RETRY; 41925276c616SSean Christopherson } 4193c50d8ae3SPaolo Bonzini } 4194c50d8ae3SPaolo Bonzini 4195*76657687SPeter Xu /* 4196*76657687SPeter Xu * Allow gup to bail on pending non-fatal signals when it's also allowed 4197*76657687SPeter Xu * to wait for IO. Note, gup always bails if it is unable to quickly 4198*76657687SPeter Xu * get a page and a fatal signal, i.e. SIGKILL, is pending. 4199*76657687SPeter Xu */ 4200*76657687SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, 42013647cd04SPaolo Bonzini fault->write, &fault->map_writable, 42023647cd04SPaolo Bonzini &fault->hva); 42035276c616SSean Christopherson return RET_PF_CONTINUE; 4204c50d8ae3SPaolo Bonzini } 4205c50d8ae3SPaolo Bonzini 4206a955cad8SSean Christopherson /* 4207a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4208a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4209a955cad8SSean Christopherson */ 4210a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4211a955cad8SSean Christopherson struct kvm_page_fault *fault, int mmu_seq) 4212a955cad8SSean Christopherson { 4213b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 421418c841e1SSean Christopherson 421518c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 421618c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 421718c841e1SSean Christopherson return true; 421818c841e1SSean Christopherson 421918c841e1SSean Christopherson /* 422018c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 422118c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 422218c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 422318c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 422418c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 422518c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 422618c841e1SSean Christopherson */ 4227527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4228a955cad8SSean Christopherson return true; 4229a955cad8SSean Christopherson 4230a955cad8SSean Christopherson return fault->slot && 423120ec3ebdSChao Peng mmu_invalidate_retry_hva(vcpu->kvm, mmu_seq, fault->hva); 4232a955cad8SSean Christopherson } 4233a955cad8SSean Christopherson 42344326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4235c50d8ae3SPaolo Bonzini { 423663c0cac9SDavid Matlack bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu); 4237c50d8ae3SPaolo Bonzini 42380f90e1c1SSean Christopherson unsigned long mmu_seq; 423983f06fa7SSean Christopherson int r; 4240c50d8ae3SPaolo Bonzini 42413c8ad5a6SPaolo Bonzini fault->gfn = fault->addr >> PAGE_SHIFT; 4242e710c5f6SDavid Matlack fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); 4243e710c5f6SDavid Matlack 4244b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4245c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4246c50d8ae3SPaolo Bonzini 42473c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4248c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4249c4371c2aSSean Christopherson return r; 425083291445SSean Christopherson 4251378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4252c50d8ae3SPaolo Bonzini if (r) 4253c50d8ae3SPaolo Bonzini return r; 4254c50d8ae3SPaolo Bonzini 425520ec3ebdSChao Peng mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4256367fd790SSean Christopherson smp_rmb(); 4257367fd790SSean Christopherson 42585276c616SSean Christopherson r = kvm_faultin_pfn(vcpu, fault); 42595276c616SSean Christopherson if (r != RET_PF_CONTINUE) 42608f32d5e5SMaxim Levitsky return r; 4261367fd790SSean Christopherson 42625276c616SSean Christopherson r = handle_abnormal_pfn(vcpu, fault, ACC_ALL); 42635276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4264367fd790SSean Christopherson return r; 4265367fd790SSean Christopherson 4266367fd790SSean Christopherson r = RET_PF_RETRY; 4267a2855afcSBen Gardon 42680b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4269a2855afcSBen Gardon read_lock(&vcpu->kvm->mmu_lock); 4270a2855afcSBen Gardon else 4271531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4272a2855afcSBen Gardon 4273a955cad8SSean Christopherson if (is_page_fault_stale(vcpu, fault, mmu_seq)) 4274367fd790SSean Christopherson goto out_unlock; 4275a955cad8SSean Christopherson 42767bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 42777bd7ded6SSean Christopherson if (r) 4278367fd790SSean Christopherson goto out_unlock; 4279bb18842eSBen Gardon 42800b873fd7SDavid Matlack if (is_tdp_mmu_fault) 42812f6305ddSPaolo Bonzini r = kvm_tdp_mmu_map(vcpu, fault); 4282bb18842eSBen Gardon else 428343b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 42840f90e1c1SSean Christopherson 4285367fd790SSean Christopherson out_unlock: 42860b873fd7SDavid Matlack if (is_tdp_mmu_fault) 4287a2855afcSBen Gardon read_unlock(&vcpu->kvm->mmu_lock); 4288a2855afcSBen Gardon else 4289531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 42903647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4291367fd790SSean Christopherson return r; 4292c50d8ae3SPaolo Bonzini } 4293c50d8ae3SPaolo Bonzini 4294c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4295c501040aSPaolo Bonzini struct kvm_page_fault *fault) 42960f90e1c1SSean Christopherson { 42974326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 42980f90e1c1SSean Christopherson 42990f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 43004326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 43014326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 43020f90e1c1SSean Christopherson } 43030f90e1c1SSean Christopherson 4304c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4305c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4306c50d8ae3SPaolo Bonzini { 4307c50d8ae3SPaolo Bonzini int r = 1; 43089ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4309c50d8ae3SPaolo Bonzini 4310736c291cSSean Christopherson #ifndef CONFIG_X86_64 4311736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4312736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4313736c291cSSean Christopherson return -EFAULT; 4314736c291cSSean Christopherson #endif 4315736c291cSSean Christopherson 4316c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 43179ce372b3SVitaly Kuznetsov if (!flags) { 4318faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4319c50d8ae3SPaolo Bonzini 4320c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4321c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4322c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4323c50d8ae3SPaolo Bonzini insn_len); 43249ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 432568fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4326c50d8ae3SPaolo Bonzini local_irq_disable(); 43276bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4328c50d8ae3SPaolo Bonzini local_irq_enable(); 43299ce372b3SVitaly Kuznetsov } else { 43309ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4331c50d8ae3SPaolo Bonzini } 43329ce372b3SVitaly Kuznetsov 4333c50d8ae3SPaolo Bonzini return r; 4334c50d8ae3SPaolo Bonzini } 4335c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4336c50d8ae3SPaolo Bonzini 4337c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4338c50d8ae3SPaolo Bonzini { 4339d5e90a69SSean Christopherson /* 4340d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4341d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 4342d5e90a69SSean Christopherson * across the entire mapping. If the host MTRRs are ignored by TDP 4343d5e90a69SSean Christopherson * (shadow_memtype_mask is non-zero), and the VM has non-coherent DMA 4344d5e90a69SSean Christopherson * (DMA doesn't snoop CPU caches), KVM's ABI is to honor the memtype 4345d5e90a69SSean Christopherson * from the guest's MTRRs so that guest accesses to memory that is 4346d5e90a69SSean Christopherson * DMA'd aren't cached against the guest's wishes. 4347d5e90a69SSean Christopherson * 4348d5e90a69SSean Christopherson * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 4349d5e90a69SSean Christopherson * e.g. KVM will force UC memtype for host MMIO. 4350d5e90a69SSean Christopherson */ 4351d5e90a69SSean Christopherson if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) { 4352d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 43534326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 43544326e57eSPaolo Bonzini gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1); 4355c50d8ae3SPaolo Bonzini 4356cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4357cb9b88c6SSean Christopherson break; 4358d5e90a69SSean Christopherson } 4359c50d8ae3SPaolo Bonzini } 4360c50d8ae3SPaolo Bonzini 43614326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4362c50d8ae3SPaolo Bonzini } 4363c50d8ae3SPaolo Bonzini 436484a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4365c50d8ae3SPaolo Bonzini { 4366c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4367c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4368c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 43695efac074SPaolo Bonzini context->invlpg = NULL; 4370c50d8ae3SPaolo Bonzini } 4371c50d8ae3SPaolo Bonzini 4372be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 43730be44352SSean Christopherson union kvm_mmu_page_role role) 43740be44352SSean Christopherson { 4375be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 43765499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4377e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 43780be44352SSean Christopherson } 43790be44352SSean Christopherson 4380c50d8ae3SPaolo Bonzini /* 43815499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 43825499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 43835499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 43845499ea73SPaolo Bonzini * true is returned. 43855499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 43865499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4387c50d8ae3SPaolo Bonzini */ 43885499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 43895499ea73SPaolo Bonzini gpa_t new_pgd, 4390c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4391c50d8ae3SPaolo Bonzini { 4392c50d8ae3SPaolo Bonzini uint i; 4393c50d8ae3SPaolo Bonzini 4394b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 43950be44352SSean Christopherson return true; 43960be44352SSean Christopherson 4397c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 43985499ea73SPaolo Bonzini /* 43995499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 44005499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 44015499ea73SPaolo Bonzini * 0 C 1 2 3 44025499ea73SPaolo Bonzini * 1 C 0 2 3 44035499ea73SPaolo Bonzini * 2 C 0 1 3 44045499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 44055499ea73SPaolo Bonzini */ 4406b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4407b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 44085499ea73SPaolo Bonzini return true; 4409c50d8ae3SPaolo Bonzini } 4410c50d8ae3SPaolo Bonzini 44115499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 44125499ea73SPaolo Bonzini return false; 4413c50d8ae3SPaolo Bonzini } 4414c50d8ae3SPaolo Bonzini 4415c50d8ae3SPaolo Bonzini /* 44165499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 44175499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 44185499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 44195499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 44205499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 44215499ea73SPaolo Bonzini */ 44225499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 44235499ea73SPaolo Bonzini gpa_t new_pgd, 44245499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 44255499ea73SPaolo Bonzini { 44265499ea73SPaolo Bonzini uint i; 44275499ea73SPaolo Bonzini 44285499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 44295499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 44305499ea73SPaolo Bonzini goto hit; 44315499ea73SPaolo Bonzini 44325499ea73SPaolo Bonzini return false; 44335499ea73SPaolo Bonzini 44345499ea73SPaolo Bonzini hit: 44355499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 44365499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 44375499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 44385499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 44395499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 44405499ea73SPaolo Bonzini return true; 44415499ea73SPaolo Bonzini } 44425499ea73SPaolo Bonzini 44435499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 44445499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 44455499ea73SPaolo Bonzini { 44465499ea73SPaolo Bonzini /* 44475499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4448c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4449c50d8ae3SPaolo Bonzini * later if necessary. 4450c50d8ae3SPaolo Bonzini */ 44515499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 44525499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4453c50d8ae3SPaolo Bonzini 44545499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 44555499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 44565499ea73SPaolo Bonzini else 44575499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4458c50d8ae3SPaolo Bonzini } 4459c50d8ae3SPaolo Bonzini 4460d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4461c50d8ae3SPaolo Bonzini { 44620c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 44637a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 44640c1c92f1SPaolo Bonzini 44655499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 44665499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4467b869855bSSean Christopherson return; 4468c50d8ae3SPaolo Bonzini } 4469c50d8ae3SPaolo Bonzini 4470c50d8ae3SPaolo Bonzini /* 4471b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4472b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4473527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4474527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4475b869855bSSean Christopherson */ 4476b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4477b869855bSSean Christopherson 4478b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4479b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4480b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4481b5129100SSean Christopherson } 4482b869855bSSean Christopherson 4483b869855bSSean Christopherson /* 4484b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4485b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4486b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4487b869855bSSean Christopherson * the shadow page tables. 4488c50d8ae3SPaolo Bonzini */ 4489c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4490c50d8ae3SPaolo Bonzini 4491daa5b6c1SBen Gardon /* 4492daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4493daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4494daa5b6c1SBen Gardon */ 4495daa5b6c1SBen Gardon if (!new_role.direct) 4496daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4497b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4498c50d8ae3SPaolo Bonzini } 4499be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4500c50d8ae3SPaolo Bonzini 4501c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4502c50d8ae3SPaolo Bonzini { 4503c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4504c50d8ae3SPaolo Bonzini } 4505c50d8ae3SPaolo Bonzini 4506c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4507c3e5e415SLai Jiangshan unsigned int access) 4508c50d8ae3SPaolo Bonzini { 4509c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4510c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4511c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4512c50d8ae3SPaolo Bonzini return true; 4513c50d8ae3SPaolo Bonzini } 4514c50d8ae3SPaolo Bonzini 4515c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4516c50d8ae3SPaolo Bonzini return true; 4517c50d8ae3SPaolo Bonzini } 4518c50d8ae3SPaolo Bonzini 4519c50d8ae3SPaolo Bonzini return false; 4520c50d8ae3SPaolo Bonzini } 4521c50d8ae3SPaolo Bonzini 4522c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4523c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4524c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4525c50d8ae3SPaolo Bonzini #undef PTTYPE 4526c50d8ae3SPaolo Bonzini 4527c50d8ae3SPaolo Bonzini #define PTTYPE 64 4528c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4529c50d8ae3SPaolo Bonzini #undef PTTYPE 4530c50d8ae3SPaolo Bonzini 4531c50d8ae3SPaolo Bonzini #define PTTYPE 32 4532c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4533c50d8ae3SPaolo Bonzini #undef PTTYPE 4534c50d8ae3SPaolo Bonzini 4535c50d8ae3SPaolo Bonzini static void 4536b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 45375b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4538c50d8ae3SPaolo Bonzini bool pse, bool amd) 4539c50d8ae3SPaolo Bonzini { 4540c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4541c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 45425b7f575cSSean Christopherson u64 high_bits_rsvd; 4543c50d8ae3SPaolo Bonzini 4544c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4545c50d8ae3SPaolo Bonzini 4546c50d8ae3SPaolo Bonzini if (!gbpages) 4547c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4548c50d8ae3SPaolo Bonzini 45495b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 45505b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 45515b7f575cSSean Christopherson else 45525b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 45535b7f575cSSean Christopherson 45545b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 45555b7f575cSSean Christopherson if (!nx) 45565b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 45575b7f575cSSean Christopherson 4558c50d8ae3SPaolo Bonzini /* 4559c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4560c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4561c50d8ae3SPaolo Bonzini */ 4562c50d8ae3SPaolo Bonzini if (amd) 4563c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4564c50d8ae3SPaolo Bonzini 4565c50d8ae3SPaolo Bonzini switch (level) { 4566c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4567c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4568c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4569c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4570c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4571c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4572c50d8ae3SPaolo Bonzini 4573c50d8ae3SPaolo Bonzini if (!pse) { 4574c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4575c50d8ae3SPaolo Bonzini break; 4576c50d8ae3SPaolo Bonzini } 4577c50d8ae3SPaolo Bonzini 4578c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4579c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4580c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4581c50d8ae3SPaolo Bonzini else 4582c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4583c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4584c50d8ae3SPaolo Bonzini break; 4585c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 45865b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 45875b7f575cSSean Christopherson high_bits_rsvd | 45885b7f575cSSean Christopherson rsvd_bits(5, 8) | 45895b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 45905b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 45915b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 45925b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4593c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4594c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4595c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4596c50d8ae3SPaolo Bonzini break; 4597c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 45985b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 45995b7f575cSSean Christopherson nonleaf_bit8_rsvd | 46005b7f575cSSean Christopherson rsvd_bits(7, 7); 4601c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4602c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4603df561f66SGustavo A. R. Silva fallthrough; 4604c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 46055b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 46065b7f575cSSean Christopherson nonleaf_bit8_rsvd | 46075b7f575cSSean Christopherson rsvd_bits(7, 7); 46085b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 46095b7f575cSSean Christopherson gbpages_bit_rsvd; 46105b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 46115b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4612c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4613c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 46145b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 46155b7f575cSSean Christopherson gbpages_bit_rsvd | 4616c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 46175b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4618c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4619c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4620c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4621c50d8ae3SPaolo Bonzini break; 4622c50d8ae3SPaolo Bonzini } 4623c50d8ae3SPaolo Bonzini } 4624c50d8ae3SPaolo Bonzini 462527de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 462627de9250SSean Christopherson { 462727de9250SSean Christopherson /* 462827de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 462927de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 463027de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 463127de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 463227de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 463327de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 463427de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 463527de9250SSean Christopherson */ 463627de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 463727de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 463827de9250SSean Christopherson } 463927de9250SSean Christopherson 4640c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4641c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4642c50d8ae3SPaolo Bonzini { 4643b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 46445b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 46454d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 464627de9250SSean Christopherson guest_can_use_gbpages(vcpu), 46474e9c0d80SSean Christopherson is_cr4_pse(context), 464823493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4649c50d8ae3SPaolo Bonzini } 4650c50d8ae3SPaolo Bonzini 4651c50d8ae3SPaolo Bonzini static void 4652c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 465384ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4654c50d8ae3SPaolo Bonzini { 46555b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 465684ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4657c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4658c50d8ae3SPaolo Bonzini 465984ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 466084ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 466184ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 466284ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 466384ea5c09SLai Jiangshan 46645b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 46655b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 466684ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 466784ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 46685b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4669c50d8ae3SPaolo Bonzini 4670c50d8ae3SPaolo Bonzini /* large page */ 4671c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4672c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 467384ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 467484ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4675c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4676c50d8ae3SPaolo Bonzini 4677c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4678c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4679c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4680c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4681c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4682c50d8ae3SPaolo Bonzini if (!execonly) { 4683c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4684c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4685c50d8ae3SPaolo Bonzini } 4686c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4687c50d8ae3SPaolo Bonzini } 4688c50d8ae3SPaolo Bonzini 4689c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 469084ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4691c50d8ae3SPaolo Bonzini { 4692c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 469384ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 469484ea5c09SLai Jiangshan huge_page_level); 4695c50d8ae3SPaolo Bonzini } 4696c50d8ae3SPaolo Bonzini 46976f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 46986f8e65a6SSean Christopherson { 46996f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 47006f8e65a6SSean Christopherson } 47016f8e65a6SSean Christopherson 4702c50d8ae3SPaolo Bonzini /* 4703c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4704c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4705c50d8ae3SPaolo Bonzini * follow the features in guest. 4706c50d8ae3SPaolo Bonzini */ 470716be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 470816be1d12SSean Christopherson struct kvm_mmu *context) 4709c50d8ae3SPaolo Bonzini { 47108c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 47118c985b2dSSean Christopherson bool is_amd = true; 47128c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 47138c985b2dSSean Christopherson bool is_pse = false; 4714c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4715c50d8ae3SPaolo Bonzini int i; 4716c50d8ae3SPaolo Bonzini 4717a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 47188c985b2dSSean Christopherson 4719c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4720b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4721a972e29cSPaolo Bonzini context->root_role.level, 47227a458f0eSPaolo Bonzini context->root_role.efer_nx, 472327de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4724c50d8ae3SPaolo Bonzini 4725c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4726c50d8ae3SPaolo Bonzini return; 4727c50d8ae3SPaolo Bonzini 4728a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4729e54f1ff2SKai Huang /* 4730e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4731e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4732e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4733e54f1ff2SKai Huang * not allowed to be set. 4734e54f1ff2SKai Huang */ 4735e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4736e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4737e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4738e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4739c50d8ae3SPaolo Bonzini } 4740c50d8ae3SPaolo Bonzini 4741c50d8ae3SPaolo Bonzini } 4742c50d8ae3SPaolo Bonzini 4743c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4744c50d8ae3SPaolo Bonzini { 4745c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4746c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4747c50d8ae3SPaolo Bonzini } 4748c50d8ae3SPaolo Bonzini 4749c50d8ae3SPaolo Bonzini /* 4750c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4751c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4752c50d8ae3SPaolo Bonzini */ 4753c50d8ae3SPaolo Bonzini static void 4754e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4755c50d8ae3SPaolo Bonzini { 4756c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4757c50d8ae3SPaolo Bonzini int i; 4758c50d8ae3SPaolo Bonzini 4759c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4760c50d8ae3SPaolo Bonzini 4761c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4762b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 47636c6ab524SSean Christopherson context->root_role.level, true, 4764c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 47658c985b2dSSean Christopherson false, true); 4766c50d8ae3SPaolo Bonzini else 4767c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 476884ea5c09SLai Jiangshan reserved_hpa_bits(), false, 476984ea5c09SLai Jiangshan max_huge_page_level); 4770c50d8ae3SPaolo Bonzini 4771c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4772c50d8ae3SPaolo Bonzini return; 4773c50d8ae3SPaolo Bonzini 4774a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4775c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4776c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4777c50d8ae3SPaolo Bonzini } 4778c50d8ae3SPaolo Bonzini } 4779c50d8ae3SPaolo Bonzini 4780c50d8ae3SPaolo Bonzini /* 4781c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4782c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4783c50d8ae3SPaolo Bonzini */ 4784c50d8ae3SPaolo Bonzini static void 4785e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4786c50d8ae3SPaolo Bonzini { 4787c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 478884ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 478984ea5c09SLai Jiangshan max_huge_page_level); 4790c50d8ae3SPaolo Bonzini } 4791c50d8ae3SPaolo Bonzini 4792c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4793c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4794c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4795c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4796c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4797c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4798c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4799c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4800c50d8ae3SPaolo Bonzini 4801c50d8ae3SPaolo Bonzini 4802c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4803c50d8ae3SPaolo Bonzini { 4804c50d8ae3SPaolo Bonzini unsigned byte; 4805c50d8ae3SPaolo Bonzini 4806c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4807c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4808c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4809c50d8ae3SPaolo Bonzini 4810c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4811c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4812c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 481390599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4814c50d8ae3SPaolo Bonzini 4815c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4816c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4817c50d8ae3SPaolo Bonzini 4818c50d8ae3SPaolo Bonzini /* 4819c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4820c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4821c50d8ae3SPaolo Bonzini */ 4822c50d8ae3SPaolo Bonzini 4823c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4824c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4825c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4826c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4827c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4828c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4829c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4830c50d8ae3SPaolo Bonzini u8 smepf = 0; 4831c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4832c50d8ae3SPaolo Bonzini u8 smapf = 0; 4833c50d8ae3SPaolo Bonzini 4834c50d8ae3SPaolo Bonzini if (!ept) { 4835c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4836c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4837c50d8ae3SPaolo Bonzini 4838c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 483990599c28SSean Christopherson if (!efer_nx) 4840c50d8ae3SPaolo Bonzini ff = 0; 4841c50d8ae3SPaolo Bonzini 4842c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4843c50d8ae3SPaolo Bonzini if (!cr0_wp) 4844c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4845c50d8ae3SPaolo Bonzini 4846c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4847c50d8ae3SPaolo Bonzini if (cr4_smep) 4848c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4849c50d8ae3SPaolo Bonzini 4850c50d8ae3SPaolo Bonzini /* 4851c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4852c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4853c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4854c50d8ae3SPaolo Bonzini * conditions are true: 4855c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4856c50d8ae3SPaolo Bonzini * - A user page is accessed 4857c50d8ae3SPaolo Bonzini * - The access is not a fetch 48584f4aa80eSLai Jiangshan * - The access is supervisor mode 48594f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4860c50d8ae3SPaolo Bonzini * 486194b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 486294b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4863c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4864c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4865c50d8ae3SPaolo Bonzini */ 4866c50d8ae3SPaolo Bonzini if (cr4_smap) 4867c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4868c50d8ae3SPaolo Bonzini } 4869c50d8ae3SPaolo Bonzini 4870c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4871c50d8ae3SPaolo Bonzini } 4872c50d8ae3SPaolo Bonzini } 4873c50d8ae3SPaolo Bonzini 4874c50d8ae3SPaolo Bonzini /* 4875c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4876c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4877c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4878c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4879c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4880c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4881c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4882c50d8ae3SPaolo Bonzini * 4883c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4884c50d8ae3SPaolo Bonzini * page tables and the machine state: 4885c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4886c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4887c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4888c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4889c50d8ae3SPaolo Bonzini * 4890c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4891c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4892c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4893c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4894c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4895c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4896c50d8ae3SPaolo Bonzini * only will be masked away. 4897c50d8ae3SPaolo Bonzini */ 48982e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4899c50d8ae3SPaolo Bonzini { 4900c50d8ae3SPaolo Bonzini unsigned bit; 4901c50d8ae3SPaolo Bonzini bool wp; 4902c50d8ae3SPaolo Bonzini 4903c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4904a3ca5281SChenyi Qiang 4905a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4906c50d8ae3SPaolo Bonzini return; 4907c50d8ae3SPaolo Bonzini 49082e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 4909c50d8ae3SPaolo Bonzini 4910c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 4911c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 4912c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 4913c50d8ae3SPaolo Bonzini 4914c50d8ae3SPaolo Bonzini pfec = bit << 1; 4915c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 4916c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 4917c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 4918c50d8ae3SPaolo Bonzini 4919c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 4920c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 4921c50d8ae3SPaolo Bonzini 4922c50d8ae3SPaolo Bonzini /* 4923c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 4924c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 4925c50d8ae3SPaolo Bonzini */ 4926c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 4927c50d8ae3SPaolo Bonzini /* 4928c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 4929c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 4930c50d8ae3SPaolo Bonzini */ 4931c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 4932c50d8ae3SPaolo Bonzini 4933c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 4934c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 4935c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 4936c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 4937c50d8ae3SPaolo Bonzini 4938c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 4939c50d8ae3SPaolo Bonzini } 4940c50d8ae3SPaolo Bonzini } 4941c50d8ae3SPaolo Bonzini 4942533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 4943533f9a4bSSean Christopherson struct kvm_mmu *mmu) 4944c50d8ae3SPaolo Bonzini { 4945533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 4946533f9a4bSSean Christopherson return; 4947c50d8ae3SPaolo Bonzini 4948c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 4949533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 4950533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 4951c50d8ae3SPaolo Bonzini } 4952c50d8ae3SPaolo Bonzini 4953fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 4954c50d8ae3SPaolo Bonzini { 4955c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 4956c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 4957c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 4958c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 4959c50d8ae3SPaolo Bonzini } 4960c50d8ae3SPaolo Bonzini 496184a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 4962c50d8ae3SPaolo Bonzini { 4963c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 4964c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 4965c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 4966c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 4967c50d8ae3SPaolo Bonzini } 4968c50d8ae3SPaolo Bonzini 49697a7ae829SPaolo Bonzini static union kvm_cpu_role 4970e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 4971e5ed0fb0SPaolo Bonzini { 49727a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 4973e5ed0fb0SPaolo Bonzini 4974e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 4975e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 4976e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 4977e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 4978e5ed0fb0SPaolo Bonzini 4979e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 4980e5ed0fb0SPaolo Bonzini role.base.direct = 1; 4981e5ed0fb0SPaolo Bonzini return role; 4982e5ed0fb0SPaolo Bonzini } 4983e5ed0fb0SPaolo Bonzini 4984e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 4985e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 4986e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 4987e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 4988e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 498960f3cb60SPaolo Bonzini 499060f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 499160f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 499260f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 499360f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 499460f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 499560f3cb60SPaolo Bonzini else 499660f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 4997e5ed0fb0SPaolo Bonzini 4998e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 4999e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 5000e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 5001e5ed0fb0SPaolo Bonzini 5002e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 5003e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 5004e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 5005e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 5006e5ed0fb0SPaolo Bonzini return role; 5007e5ed0fb0SPaolo Bonzini } 5008e5ed0fb0SPaolo Bonzini 5009d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 5010d468d94bSSean Christopherson { 5011746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5012746700d2SWei Huang if (tdp_root_level) 5013746700d2SWei Huang return tdp_root_level; 5014746700d2SWei Huang 5015d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 501683013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5017d468d94bSSean Christopherson return 4; 5018d468d94bSSean Christopherson 501983013059SSean Christopherson return max_tdp_level; 5020d468d94bSSean Christopherson } 5021d468d94bSSean Christopherson 50227a458f0eSPaolo Bonzini static union kvm_mmu_page_role 50238626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 50247a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5025c50d8ae3SPaolo Bonzini { 50267a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5027c50d8ae3SPaolo Bonzini 50287a458f0eSPaolo Bonzini role.access = ACC_ALL; 50297a458f0eSPaolo Bonzini role.cr0_wp = true; 50307a458f0eSPaolo Bonzini role.efer_nx = true; 50317a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 50327a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 503354275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 50347a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 50357a458f0eSPaolo Bonzini role.direct = true; 50367a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5037c50d8ae3SPaolo Bonzini 5038c50d8ae3SPaolo Bonzini return role; 5039c50d8ae3SPaolo Bonzini } 5040c50d8ae3SPaolo Bonzini 504139e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5042a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5043c50d8ae3SPaolo Bonzini { 50448c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 50457a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5046c50d8ae3SPaolo Bonzini 5047e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 50487a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5049c50d8ae3SPaolo Bonzini return; 5050c50d8ae3SPaolo Bonzini 5051e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 50527a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 50537a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5054c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 50555efac074SPaolo Bonzini context->invlpg = NULL; 5056d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5057c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5058c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5059c50d8ae3SPaolo Bonzini 506036f26787SSean Christopherson if (!is_cr0_pg(context)) 5061c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 506236f26787SSean Christopherson else if (is_cr4_pae(context)) 5063c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5064f4bd6f73SSean Christopherson else 5065c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5066c50d8ae3SPaolo Bonzini 5067533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5068e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5069c50d8ae3SPaolo Bonzini } 5070c50d8ae3SPaolo Bonzini 50718c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 50727a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 50737a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5074c50d8ae3SPaolo Bonzini { 5075e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 50767a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 507718db1b17SSean Christopherson return; 5078c50d8ae3SPaolo Bonzini 5079e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 50807a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 508118db1b17SSean Christopherson 508236f26787SSean Christopherson if (!is_cr0_pg(context)) 508384a16226SSean Christopherson nonpaging_init_context(context); 508436f26787SSean Christopherson else if (is_cr4_pae(context)) 5085fe660f72SSean Christopherson paging64_init_context(context); 5086c50d8ae3SPaolo Bonzini else 508784a16226SSean Christopherson paging32_init_context(context); 5088c50d8ae3SPaolo Bonzini 5089533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5090c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5091c50d8ae3SPaolo Bonzini } 50920f04a2acSVitaly Kuznetsov 5093594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5094a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 50950f04a2acSVitaly Kuznetsov { 50968c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 509756b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 509856b321f9SPaolo Bonzini 509956b321f9SPaolo Bonzini root_role = cpu_role.base; 510056b321f9SPaolo Bonzini 510156b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 510256b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 510356b321f9SPaolo Bonzini 510456b321f9SPaolo Bonzini /* 510556b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 510656b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 510756b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 510856b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 510956b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 511056b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 511156b321f9SPaolo Bonzini * MMU contexts. 511256b321f9SPaolo Bonzini */ 511356b321f9SPaolo Bonzini root_role.efer_nx = true; 51140f04a2acSVitaly Kuznetsov 51157a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 51160f04a2acSVitaly Kuznetsov } 51170f04a2acSVitaly Kuznetsov 5118dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5119dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 51200f04a2acSVitaly Kuznetsov { 51218c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5122594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5123594e91a1SSean Christopherson .cr0 = cr0, 512428f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5125594e91a1SSean Christopherson .efer = efer, 5126594e91a1SSean Christopherson }; 51277a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 512856b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 512956b321f9SPaolo Bonzini 513056b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 513156b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 513256b321f9SPaolo Bonzini 513356b321f9SPaolo Bonzini root_role = cpu_role.base; 513456b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 513584e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 513684e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 513784e5ffd0SLai Jiangshan root_role.passthrough = 1; 51380f04a2acSVitaly Kuznetsov 51397a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5140d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 51410f04a2acSVitaly Kuznetsov } 51420f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5143c50d8ae3SPaolo Bonzini 51447a7ae829SPaolo Bonzini static union kvm_cpu_role 5145c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5146bb1fcc70SSean Christopherson bool execonly, u8 level) 5147c50d8ae3SPaolo Bonzini { 51487a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5149c50d8ae3SPaolo Bonzini 5150daed87b8SPaolo Bonzini /* 5151daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5152daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5153daed87b8SPaolo Bonzini */ 5154daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5155bb1fcc70SSean Christopherson role.base.level = level; 5156bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5157c50d8ae3SPaolo Bonzini role.base.direct = false; 5158c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5159c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5160c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5161c50d8ae3SPaolo Bonzini 5162cd6767c3SSean Christopherson role.ext.word = 0; 5163c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5164cd6767c3SSean Christopherson role.ext.valid = 1; 5165c50d8ae3SPaolo Bonzini 5166c50d8ae3SPaolo Bonzini return role; 5167c50d8ae3SPaolo Bonzini } 5168c50d8ae3SPaolo Bonzini 5169c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5170cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5171cc022ae1SLai Jiangshan gpa_t new_eptp) 5172c50d8ae3SPaolo Bonzini { 51738c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5174bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 51757a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5176c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5177bb1fcc70SSean Christopherson execonly, level); 5178c50d8ae3SPaolo Bonzini 5179e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5180e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5181e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 51827a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 518318db1b17SSean Christopherson 5184c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5185c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5186c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 5187c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 5188347a0d0dSPaolo Bonzini 5189c596f147SSean Christopherson update_permission_bitmask(context, true); 519028f091bcSPaolo Bonzini context->pkru_mask = 0; 5191cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5192e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5193c50d8ae3SPaolo Bonzini } 51943cffc89dSPaolo Bonzini 5195d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 51963cffc89dSPaolo Bonzini } 5197c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5198c50d8ae3SPaolo Bonzini 519939e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5200a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5201c50d8ae3SPaolo Bonzini { 52028c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5203c50d8ae3SPaolo Bonzini 5204a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5205929d1cfaSPaolo Bonzini 5206d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5207c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5208c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5209c50d8ae3SPaolo Bonzini } 5210c50d8ae3SPaolo Bonzini 521139e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5212a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5213c50d8ae3SPaolo Bonzini { 5214c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5215c50d8ae3SPaolo Bonzini 5216e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5217c50d8ae3SPaolo Bonzini return; 5218c50d8ae3SPaolo Bonzini 5219e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5220d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5221c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5222c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5223c50d8ae3SPaolo Bonzini 5224c50d8ae3SPaolo Bonzini /* 52255efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 52265efac074SPaolo Bonzini * SPTEs. 52275efac074SPaolo Bonzini */ 52285efac074SPaolo Bonzini g_context->invlpg = NULL; 52295efac074SPaolo Bonzini 52305efac074SPaolo Bonzini /* 5231c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5232c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5233c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5234c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5235c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5236c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5237c50d8ae3SPaolo Bonzini */ 5238fa4b5588SSean Christopherson if (!is_paging(vcpu)) 52391f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5240fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 52411f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5242fa4b5588SSean Christopherson else if (is_pae(vcpu)) 52431f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5244fa4b5588SSean Christopherson else 52451f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5246fa4b5588SSean Christopherson 5247533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5248c50d8ae3SPaolo Bonzini } 5249c50d8ae3SPaolo Bonzini 5250c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5251c50d8ae3SPaolo Bonzini { 525239e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5253a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 525439e7e2bfSPaolo Bonzini 5255c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5256a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5257c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5258a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5259c50d8ae3SPaolo Bonzini else 5260a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5261c50d8ae3SPaolo Bonzini } 5262c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5263c50d8ae3SPaolo Bonzini 526449c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 526549c6f875SSean Christopherson { 526649c6f875SSean Christopherson /* 526749c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 526849c6f875SSean Christopherson * information is factored into reserved bit calculations. 5269feb627e8SVitaly Kuznetsov * 5270feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5271feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5272feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5273feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5274feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5275feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5276feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 527749c6f875SSean Christopherson */ 52787a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 52797a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 52807a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5281e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5282e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5283e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 528449c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 528563f5a190SSean Christopherson 528663f5a190SSean Christopherson /* 5287feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5288feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 528963f5a190SSean Christopherson */ 5290feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 529149c6f875SSean Christopherson } 529249c6f875SSean Christopherson 5293c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5294c50d8ae3SPaolo Bonzini { 5295c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5296c9060662SSean Christopherson kvm_init_mmu(vcpu); 5297c50d8ae3SPaolo Bonzini } 5298c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5299c50d8ae3SPaolo Bonzini 5300c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5301c50d8ae3SPaolo Bonzini { 5302c50d8ae3SPaolo Bonzini int r; 5303c50d8ae3SPaolo Bonzini 5304347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5305c50d8ae3SPaolo Bonzini if (r) 5306c50d8ae3SPaolo Bonzini goto out; 5307748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5308c50d8ae3SPaolo Bonzini if (r) 5309c50d8ae3SPaolo Bonzini goto out; 5310347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 53116e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 53126e6ec584SSean Christopherson else 53136e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5314c50d8ae3SPaolo Bonzini if (r) 5315c50d8ae3SPaolo Bonzini goto out; 5316a91f387bSSean Christopherson 5317a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5318a91f387bSSean Christopherson 5319727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5320db01416bSSean Christopherson 5321db01416bSSean Christopherson /* 5322db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5323db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5324db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5325db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5326db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5327db01416bSSean Christopherson */ 5328e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5329c50d8ae3SPaolo Bonzini out: 5330c50d8ae3SPaolo Bonzini return r; 5331c50d8ae3SPaolo Bonzini } 5332c50d8ae3SPaolo Bonzini 5333c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5334c50d8ae3SPaolo Bonzini { 53350c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 53360c1c92f1SPaolo Bonzini 53370c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5338b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 53390c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5340b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 53416d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5342c50d8ae3SPaolo Bonzini } 5343c50d8ae3SPaolo Bonzini 5344527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5345527d5cd7SSean Christopherson { 5346527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5347527d5cd7SSean Christopherson 5348527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5349527d5cd7SSean Christopherson return false; 5350527d5cd7SSean Christopherson 5351527d5cd7SSean Christopherson /* 5352527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5353527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5354527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5355527d5cd7SSean Christopherson * such false positives are relatively rare: 5356527d5cd7SSean Christopherson * 5357527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5358527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5359527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5360527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5361527d5cd7SSean Christopherson */ 5362527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5363527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5364527d5cd7SSean Christopherson } 5365527d5cd7SSean Christopherson 5366527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5367527d5cd7SSean Christopherson { 5368527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5369527d5cd7SSean Christopherson int i; 5370527d5cd7SSean Christopherson 5371527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5372527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5373527d5cd7SSean Christopherson 5374527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5375cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5376527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5377527d5cd7SSean Christopherson } 5378527d5cd7SSean Christopherson 5379527d5cd7SSean Christopherson if (roots_to_free) 5380527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5381527d5cd7SSean Christopherson } 5382527d5cd7SSean Christopherson 5383527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5384527d5cd7SSean Christopherson { 5385527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5386527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5387527d5cd7SSean Christopherson } 5388527d5cd7SSean Christopherson 5389c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5390c50d8ae3SPaolo Bonzini int *bytes) 5391c50d8ae3SPaolo Bonzini { 5392c50d8ae3SPaolo Bonzini u64 gentry = 0; 5393c50d8ae3SPaolo Bonzini int r; 5394c50d8ae3SPaolo Bonzini 5395c50d8ae3SPaolo Bonzini /* 5396c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5397c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5398c50d8ae3SPaolo Bonzini * when they have the same mode. 5399c50d8ae3SPaolo Bonzini */ 5400c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5401c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5402c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5403c50d8ae3SPaolo Bonzini *bytes = 8; 5404c50d8ae3SPaolo Bonzini } 5405c50d8ae3SPaolo Bonzini 5406c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5407c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5408c50d8ae3SPaolo Bonzini if (r) 5409c50d8ae3SPaolo Bonzini gentry = 0; 5410c50d8ae3SPaolo Bonzini } 5411c50d8ae3SPaolo Bonzini 5412c50d8ae3SPaolo Bonzini return gentry; 5413c50d8ae3SPaolo Bonzini } 5414c50d8ae3SPaolo Bonzini 5415c50d8ae3SPaolo Bonzini /* 5416c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5417c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5418c50d8ae3SPaolo Bonzini */ 5419c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5420c50d8ae3SPaolo Bonzini { 5421c50d8ae3SPaolo Bonzini /* 5422c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5423c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5424c50d8ae3SPaolo Bonzini */ 54253bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5426c50d8ae3SPaolo Bonzini return false; 5427c50d8ae3SPaolo Bonzini 5428c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5429c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5430c50d8ae3SPaolo Bonzini } 5431c50d8ae3SPaolo Bonzini 5432c50d8ae3SPaolo Bonzini /* 5433c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5434c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5435c50d8ae3SPaolo Bonzini */ 5436c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5437c50d8ae3SPaolo Bonzini int bytes) 5438c50d8ae3SPaolo Bonzini { 5439c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5440c50d8ae3SPaolo Bonzini 5441c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5442c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5443c50d8ae3SPaolo Bonzini 5444c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5445bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5446c50d8ae3SPaolo Bonzini 5447c50d8ae3SPaolo Bonzini /* 5448c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5449c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5450c50d8ae3SPaolo Bonzini */ 5451c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5452c50d8ae3SPaolo Bonzini return false; 5453c50d8ae3SPaolo Bonzini 5454c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5455c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5456c50d8ae3SPaolo Bonzini 5457c50d8ae3SPaolo Bonzini return misaligned; 5458c50d8ae3SPaolo Bonzini } 5459c50d8ae3SPaolo Bonzini 5460c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5461c50d8ae3SPaolo Bonzini { 5462c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5463c50d8ae3SPaolo Bonzini u64 *spte; 5464c50d8ae3SPaolo Bonzini int level; 5465c50d8ae3SPaolo Bonzini 5466c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5467c50d8ae3SPaolo Bonzini level = sp->role.level; 5468c50d8ae3SPaolo Bonzini *nspte = 1; 5469bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5470c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5471c50d8ae3SPaolo Bonzini /* 5472c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5473c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5474c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5475c50d8ae3SPaolo Bonzini */ 5476c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5477c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5478c50d8ae3SPaolo Bonzini page_offset <<= 1; 5479c50d8ae3SPaolo Bonzini *nspte = 2; 5480c50d8ae3SPaolo Bonzini } 5481c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5482c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5483c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5484c50d8ae3SPaolo Bonzini return NULL; 5485c50d8ae3SPaolo Bonzini } 5486c50d8ae3SPaolo Bonzini 5487c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5488c50d8ae3SPaolo Bonzini return spte; 5489c50d8ae3SPaolo Bonzini } 5490c50d8ae3SPaolo Bonzini 5491c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5492c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5493c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5494c50d8ae3SPaolo Bonzini { 5495c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5496c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5497c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5498c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5499c50d8ae3SPaolo Bonzini int npte; 550006152b2dSLai Jiangshan bool flush = false; 5501c50d8ae3SPaolo Bonzini 5502c50d8ae3SPaolo Bonzini /* 5503c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5504c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5505c50d8ae3SPaolo Bonzini */ 5506c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5507c50d8ae3SPaolo Bonzini return; 5508c50d8ae3SPaolo Bonzini 5509c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5510c50d8ae3SPaolo Bonzini 5511531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5512c50d8ae3SPaolo Bonzini 5513c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5514c50d8ae3SPaolo Bonzini 5515c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5516c50d8ae3SPaolo Bonzini 5517767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5518c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5519c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5520c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5521c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5522c50d8ae3SPaolo Bonzini continue; 5523c50d8ae3SPaolo Bonzini } 5524c50d8ae3SPaolo Bonzini 5525c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5526c50d8ae3SPaolo Bonzini if (!spte) 5527c50d8ae3SPaolo Bonzini continue; 5528c50d8ae3SPaolo Bonzini 5529c50d8ae3SPaolo Bonzini while (npte--) { 5530c50d8ae3SPaolo Bonzini entry = *spte; 55312de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5532c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5533c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 55341441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 553506152b2dSLai Jiangshan flush = true; 5536c50d8ae3SPaolo Bonzini ++spte; 5537c50d8ae3SPaolo Bonzini } 5538c50d8ae3SPaolo Bonzini } 553906152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5540531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5541c50d8ae3SPaolo Bonzini } 5542c50d8ae3SPaolo Bonzini 55431075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5544c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5545c50d8ae3SPaolo Bonzini { 554692daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5547347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5548c50d8ae3SPaolo Bonzini 5549b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5550ddce6208SSean Christopherson return RET_PF_RETRY; 5551ddce6208SSean Christopherson 5552c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5553c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5554736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5555c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5556c50d8ae3SPaolo Bonzini goto emulate; 5557c50d8ae3SPaolo Bonzini } 5558c50d8ae3SPaolo Bonzini 5559c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 55607a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 55617a02674dSSean Christopherson lower_32_bits(error_code), false); 556219025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 55637b367bc9SSean Christopherson return -EIO; 5564c50d8ae3SPaolo Bonzini } 5565c50d8ae3SPaolo Bonzini 5566c50d8ae3SPaolo Bonzini if (r < 0) 5567c50d8ae3SPaolo Bonzini return r; 556883a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 556983a2ba4cSSean Christopherson return 1; 5570c50d8ae3SPaolo Bonzini 5571c50d8ae3SPaolo Bonzini /* 5572c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5573c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5574c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5575c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5576c50d8ae3SPaolo Bonzini * and resume the guest. 5577c50d8ae3SPaolo Bonzini */ 5578347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5579c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5580736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5581c50d8ae3SPaolo Bonzini return 1; 5582c50d8ae3SPaolo Bonzini } 5583c50d8ae3SPaolo Bonzini 5584c50d8ae3SPaolo Bonzini /* 5585c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5586c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5587c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5588c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5589c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5590c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5591c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5592c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5593c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5594c50d8ae3SPaolo Bonzini */ 5595736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 559692daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5597c50d8ae3SPaolo Bonzini emulate: 5598736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5599c50d8ae3SPaolo Bonzini insn_len); 5600c50d8ae3SPaolo Bonzini } 5601c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5602c50d8ae3SPaolo Bonzini 56035efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 56045efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5605c50d8ae3SPaolo Bonzini { 5606c50d8ae3SPaolo Bonzini int i; 5607c50d8ae3SPaolo Bonzini 56085efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 56095efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 56105efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5611c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5612c50d8ae3SPaolo Bonzini return; 5613c50d8ae3SPaolo Bonzini 5614e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 56155efac074SPaolo Bonzini } 56165efac074SPaolo Bonzini 56175efac074SPaolo Bonzini if (!mmu->invlpg) 56185efac074SPaolo Bonzini return; 56195efac074SPaolo Bonzini 56205efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5621b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5622c50d8ae3SPaolo Bonzini 5623c50d8ae3SPaolo Bonzini /* 5624c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5625c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5626c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5627c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5628c50d8ae3SPaolo Bonzini * just always sync it. 5629c50d8ae3SPaolo Bonzini * 5630c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5631c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5632c50d8ae3SPaolo Bonzini * for them. 5633c50d8ae3SPaolo Bonzini */ 5634c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5635c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5636c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 56375efac074SPaolo Bonzini } else { 56385efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 56395efac074SPaolo Bonzini } 56405efac074SPaolo Bonzini } 5641c50d8ae3SPaolo Bonzini 56425efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 56435efac074SPaolo Bonzini { 564405b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5645c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5646c50d8ae3SPaolo Bonzini } 5647c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5648c50d8ae3SPaolo Bonzini 56495efac074SPaolo Bonzini 5650c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5651c50d8ae3SPaolo Bonzini { 5652c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5653c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5654c50d8ae3SPaolo Bonzini uint i; 5655c50d8ae3SPaolo Bonzini 5656c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 56579f46c187SPaolo Bonzini if (mmu->invlpg) 5658b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5659c50d8ae3SPaolo Bonzini tlb_flush = true; 5660c50d8ae3SPaolo Bonzini } 5661c50d8ae3SPaolo Bonzini 5662c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5663c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5664be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 56659f46c187SPaolo Bonzini if (mmu->invlpg) 5666c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5667c50d8ae3SPaolo Bonzini tlb_flush = true; 5668c50d8ae3SPaolo Bonzini } 5669c50d8ae3SPaolo Bonzini } 5670c50d8ae3SPaolo Bonzini 5671c50d8ae3SPaolo Bonzini if (tlb_flush) 5672e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5673c50d8ae3SPaolo Bonzini 5674c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5675c50d8ae3SPaolo Bonzini 5676c50d8ae3SPaolo Bonzini /* 5677c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5678c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5679c50d8ae3SPaolo Bonzini * for them. 5680c50d8ae3SPaolo Bonzini */ 5681c50d8ae3SPaolo Bonzini } 5682c50d8ae3SPaolo Bonzini 5683746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5684746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5685c50d8ae3SPaolo Bonzini { 5686bde77235SSean Christopherson tdp_enabled = enable_tdp; 5687746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 568883013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5689703c335dSSean Christopherson 5690703c335dSSean Christopherson /* 56911d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5692703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5693703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5694703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5695703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5696703c335dSSean Christopherson */ 5697703c335dSSean Christopherson if (tdp_enabled) 56981d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5699703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 57001d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5701703c335dSSean Christopherson else 57021d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5703c50d8ae3SPaolo Bonzini } 5704bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5705c50d8ae3SPaolo Bonzini 5706c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5707269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5708269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5709269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5710c50d8ae3SPaolo Bonzini 5711c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5712c50d8ae3SPaolo Bonzini static __always_inline bool 5713269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5714c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 57151a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 57161a61b7dbSSean Christopherson bool flush) 5717c50d8ae3SPaolo Bonzini { 5718c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5719c50d8ae3SPaolo Bonzini 5720c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5721c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5722c50d8ae3SPaolo Bonzini if (iterator.rmap) 57230a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5724c50d8ae3SPaolo Bonzini 5725531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5726302695a5SSean Christopherson if (flush && flush_on_yield) { 5727c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5728c50d8ae3SPaolo Bonzini start_gfn, 5729c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5730c50d8ae3SPaolo Bonzini flush = false; 5731c50d8ae3SPaolo Bonzini } 5732531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5733c50d8ae3SPaolo Bonzini } 5734c50d8ae3SPaolo Bonzini } 5735c50d8ae3SPaolo Bonzini 5736c50d8ae3SPaolo Bonzini return flush; 5737c50d8ae3SPaolo Bonzini } 5738c50d8ae3SPaolo Bonzini 5739c50d8ae3SPaolo Bonzini static __always_inline bool 5740269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5741c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5742302695a5SSean Christopherson bool flush_on_yield) 5743c50d8ae3SPaolo Bonzini { 5744c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5745c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5746c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 57471a61b7dbSSean Christopherson flush_on_yield, false); 5748c50d8ae3SPaolo Bonzini } 5749c50d8ae3SPaolo Bonzini 5750c50d8ae3SPaolo Bonzini static __always_inline bool 5751610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5752302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5753c50d8ae3SPaolo Bonzini { 57543bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5755302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5756c50d8ae3SPaolo Bonzini } 5757c50d8ae3SPaolo Bonzini 5758c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5759c50d8ae3SPaolo Bonzini { 57604a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 57614a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5762c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 576303ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5764cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5765c50d8ae3SPaolo Bonzini } 5766c50d8ae3SPaolo Bonzini 576704d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5768c50d8ae3SPaolo Bonzini { 5769c50d8ae3SPaolo Bonzini struct page *page; 5770c50d8ae3SPaolo Bonzini int i; 5771c50d8ae3SPaolo Bonzini 5772b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5773b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 577404d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 577504d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 577604d28e37SSean Christopherson 577727f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 577827f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 577927f4fca2SLai Jiangshan return 0; 578027f4fca2SLai Jiangshan 5781c50d8ae3SPaolo Bonzini /* 5782c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5783c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5784c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5785c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 578604d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 578704d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 578804d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 578904d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 579084432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5791c50d8ae3SPaolo Bonzini */ 5792d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5793c50d8ae3SPaolo Bonzini return 0; 5794c50d8ae3SPaolo Bonzini 5795c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5796c50d8ae3SPaolo Bonzini if (!page) 5797c50d8ae3SPaolo Bonzini return -ENOMEM; 5798c50d8ae3SPaolo Bonzini 5799c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 58004a98623dSSean Christopherson 58014a98623dSSean Christopherson /* 58024a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 58034a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 58044a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 58054a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 58064a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 58074a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 58084a98623dSSean Christopherson */ 58094a98623dSSean Christopherson if (!tdp_enabled) 58104a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 58114a98623dSSean Christopherson else 5812e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 58134a98623dSSean Christopherson 5814c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5815c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5816c50d8ae3SPaolo Bonzini 5817c50d8ae3SPaolo Bonzini return 0; 5818c50d8ae3SPaolo Bonzini } 5819c50d8ae3SPaolo Bonzini 5820c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5821c50d8ae3SPaolo Bonzini { 5822c50d8ae3SPaolo Bonzini int ret; 5823c50d8ae3SPaolo Bonzini 58245962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 58255f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 58265f6078f9SSean Christopherson 58275962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 58285f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 58295962bfb7SSean Christopherson 583096880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 583196880883SSean Christopherson 5832c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5833c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5834c50d8ae3SPaolo Bonzini 583504d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5836c50d8ae3SPaolo Bonzini if (ret) 5837c50d8ae3SPaolo Bonzini return ret; 5838c50d8ae3SPaolo Bonzini 583904d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5840c50d8ae3SPaolo Bonzini if (ret) 5841c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5842c50d8ae3SPaolo Bonzini 5843c50d8ae3SPaolo Bonzini return ret; 5844c50d8ae3SPaolo Bonzini fail_allocate_root: 5845c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5846c50d8ae3SPaolo Bonzini return ret; 5847c50d8ae3SPaolo Bonzini } 5848c50d8ae3SPaolo Bonzini 5849c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5850c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5851c50d8ae3SPaolo Bonzini { 5852c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5853c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5854b28cb0cdSSean Christopherson bool unstable; 5855c50d8ae3SPaolo Bonzini 5856c50d8ae3SPaolo Bonzini restart: 5857c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5858c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5859c50d8ae3SPaolo Bonzini /* 5860c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5861c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5862c50d8ae3SPaolo Bonzini */ 5863c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5864c50d8ae3SPaolo Bonzini break; 5865c50d8ae3SPaolo Bonzini 5866c50d8ae3SPaolo Bonzini /* 5867f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5868f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5869f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5870c50d8ae3SPaolo Bonzini */ 5871f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5872c50d8ae3SPaolo Bonzini continue; 5873c50d8ae3SPaolo Bonzini 5874c50d8ae3SPaolo Bonzini /* 5875c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5876c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5877c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5878c50d8ae3SPaolo Bonzini * be in active use by the guest. 5879c50d8ae3SPaolo Bonzini */ 5880c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5881531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5882c50d8ae3SPaolo Bonzini batch = 0; 5883c50d8ae3SPaolo Bonzini goto restart; 5884c50d8ae3SPaolo Bonzini } 5885c50d8ae3SPaolo Bonzini 5886b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 5887b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 5888c50d8ae3SPaolo Bonzini batch += nr_zapped; 5889b28cb0cdSSean Christopherson 5890b28cb0cdSSean Christopherson if (unstable) 5891c50d8ae3SPaolo Bonzini goto restart; 5892c50d8ae3SPaolo Bonzini } 5893c50d8ae3SPaolo Bonzini 5894c50d8ae3SPaolo Bonzini /* 58957ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 58967ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 58977ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 58987ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 58997ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 59007ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 59017ae5840eSSean Christopherson * running with an obsolete MMU. 5902c50d8ae3SPaolo Bonzini */ 5903c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5904c50d8ae3SPaolo Bonzini } 5905c50d8ae3SPaolo Bonzini 5906c50d8ae3SPaolo Bonzini /* 5907c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 5908c50d8ae3SPaolo Bonzini * to zap obsolete pages. 5909c50d8ae3SPaolo Bonzini * 5910c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 5911c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 5912c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 5913c50d8ae3SPaolo Bonzini * after calling the function. 5914c50d8ae3SPaolo Bonzini */ 5915c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 5916c50d8ae3SPaolo Bonzini { 5917c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 5918c50d8ae3SPaolo Bonzini 5919531810caSBen Gardon write_lock(&kvm->mmu_lock); 5920c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 5921c50d8ae3SPaolo Bonzini 5922c50d8ae3SPaolo Bonzini /* 5923c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 5924c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 5925c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 5926c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 5927c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 5928c50d8ae3SPaolo Bonzini */ 5929c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 5930c50d8ae3SPaolo Bonzini 59312f6f66ccSSean Christopherson /* 59322f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 59332f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 59342f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 59352f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 5936b7cccd39SBen Gardon */ 5937b7cccd39SBen Gardon if (is_tdp_mmu_enabled(kvm)) 5938b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 5939b7cccd39SBen Gardon 5940c50d8ae3SPaolo Bonzini /* 5941c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 5942c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 5943c50d8ae3SPaolo Bonzini * mmu_valid_gen. 5944c50d8ae3SPaolo Bonzini * 5945c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 5946c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 5947c50d8ae3SPaolo Bonzini */ 5948527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 5949c50d8ae3SPaolo Bonzini 5950c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 5951faaf05b0SBen Gardon 5952531810caSBen Gardon write_unlock(&kvm->mmu_lock); 59534c6654bdSBen Gardon 5954f28e9c7fSSean Christopherson /* 5955f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 5956f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 5957f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 5958f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 5959f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 5960f28e9c7fSSean Christopherson * lead to use-after-free. 5961f28e9c7fSSean Christopherson */ 596222b94c4bSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 59634c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 5964c50d8ae3SPaolo Bonzini } 5965c50d8ae3SPaolo Bonzini 5966c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 5967c50d8ae3SPaolo Bonzini { 5968c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 5969c50d8ae3SPaolo Bonzini } 5970c50d8ae3SPaolo Bonzini 5971c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 5972c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 5973c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5974c50d8ae3SPaolo Bonzini { 5975c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 5976c50d8ae3SPaolo Bonzini } 5977c50d8ae3SPaolo Bonzini 5978a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 5979c50d8ae3SPaolo Bonzini { 5980c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 5981a1a39128SPaolo Bonzini int r; 5982c50d8ae3SPaolo Bonzini 5983a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 5984a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 5985a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); 5986ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 5987ce25681dSSean Christopherson 5988a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 5989a1a39128SPaolo Bonzini if (r < 0) 5990a1a39128SPaolo Bonzini return r; 5991fe5db27dSBen Gardon 5992c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 5993c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 5994c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 5995ada51a9dSDavid Matlack 5996ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 5997ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 5998ada51a9dSDavid Matlack 5999ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 6000ada51a9dSDavid Matlack 6001ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 6002ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 6003ada51a9dSDavid Matlack 6004a1a39128SPaolo Bonzini return 0; 6005c50d8ae3SPaolo Bonzini } 6006c50d8ae3SPaolo Bonzini 6007ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 6008ada51a9dSDavid Matlack { 6009ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 6010ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6011ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6012ada51a9dSDavid Matlack } 6013ada51a9dSDavid Matlack 6014c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6015c50d8ae3SPaolo Bonzini { 6016c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6017c50d8ae3SPaolo Bonzini 6018c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 6019fe5db27dSBen Gardon 6020fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6021ada51a9dSDavid Matlack 6022ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6023c50d8ae3SPaolo Bonzini } 6024c50d8ae3SPaolo Bonzini 60252833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 602621fa3246SSean Christopherson { 602721fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 602821fa3246SSean Christopherson struct kvm_memslots *slots; 6029f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 603021fa3246SSean Christopherson bool flush = false; 603121fa3246SSean Christopherson gfn_t start, end; 6032f4209439SMaciej S. Szmigiero int i; 603321fa3246SSean Christopherson 603421fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 603521fa3246SSean Christopherson return flush; 603621fa3246SSean Christopherson 603721fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 603821fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6039f4209439SMaciej S. Szmigiero 6040f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6041f4209439SMaciej S. Szmigiero memslot = iter.slot; 604221fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 604321fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6044f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 604521fa3246SSean Christopherson continue; 604621fa3246SSean Christopherson 6047f8480721SSean Christopherson flush = slot_handle_level_range(kvm, memslot, __kvm_zap_rmap, 604821fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 604921fa3246SSean Christopherson start, end - 1, true, flush); 605021fa3246SSean Christopherson } 605121fa3246SSean Christopherson } 605221fa3246SSean Christopherson 605321fa3246SSean Christopherson return flush; 605421fa3246SSean Christopherson } 605521fa3246SSean Christopherson 605688f58535SMaxim Levitsky /* 605788f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 605888f58535SMaxim Levitsky * (not including it) 605988f58535SMaxim Levitsky */ 6060c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6061c50d8ae3SPaolo Bonzini { 606221fa3246SSean Christopherson bool flush; 6063c50d8ae3SPaolo Bonzini int i; 6064c50d8ae3SPaolo Bonzini 6065f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6066f4209439SMaciej S. Szmigiero return; 6067f4209439SMaciej S. Szmigiero 6068531810caSBen Gardon write_lock(&kvm->mmu_lock); 60695a324c24SSean Christopherson 607020ec3ebdSChao Peng kvm_mmu_invalidate_begin(kvm, gfn_start, gfn_end); 6071edb298c6SMaxim Levitsky 60722833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 60736103bc07SBen Gardon 60746103bc07SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 60756103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 6076f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 6077f47e5bbbSSean Christopherson gfn_end, true, flush); 60786103bc07SBen Gardon } 60795a324c24SSean Christopherson 60805a324c24SSean Christopherson if (flush) 6081bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 6082bc3b3c10SSean Christopherson gfn_end - gfn_start); 60835a324c24SSean Christopherson 608420ec3ebdSChao Peng kvm_mmu_invalidate_end(kvm, gfn_start, gfn_end); 6085edb298c6SMaxim Levitsky 60865a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6087c50d8ae3SPaolo Bonzini } 6088c50d8ae3SPaolo Bonzini 6089c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 60900a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6091269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6092c50d8ae3SPaolo Bonzini { 60931346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6094c50d8ae3SPaolo Bonzini } 6095c50d8ae3SPaolo Bonzini 6096c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6097269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 60983c9bd400SJay Zhou int start_level) 6099c50d8ae3SPaolo Bonzini { 6100e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6101531810caSBen Gardon write_lock(&kvm->mmu_lock); 6102b64d740eSJunaid Shahid slot_handle_level(kvm, memslot, slot_rmap_write_protect, 6103b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6104531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6105e2209710SBen Gardon } 6106c50d8ae3SPaolo Bonzini 610724ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 610824ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6109b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 611024ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 611124ae4cfaSBen Gardon } 6112c50d8ae3SPaolo Bonzini } 6113c50d8ae3SPaolo Bonzini 6114ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6115ada51a9dSDavid Matlack { 6116ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6117ada51a9dSDavid Matlack } 6118ada51a9dSDavid Matlack 6119ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6120ada51a9dSDavid Matlack { 6121ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6122ada51a9dSDavid Matlack return true; 6123ada51a9dSDavid Matlack 6124ada51a9dSDavid Matlack /* 6125ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6126ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6127ada51a9dSDavid Matlack * is possible but not worth the complexity. 6128ada51a9dSDavid Matlack */ 6129ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6130ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6131ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6132ada51a9dSDavid Matlack } 6133ada51a9dSDavid Matlack 6134ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6135ada51a9dSDavid Matlack { 6136b9b71f43SSean Christopherson /* 6137b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6138dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6139b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6140dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6141dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6142dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6143dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6144dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6145dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6146dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6147b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6148b9b71f43SSean Christopherson */ 6149b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6150b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6151ada51a9dSDavid Matlack int r; 6152ada51a9dSDavid Matlack 6153ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6154ada51a9dSDavid Matlack 6155b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6156ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6157ada51a9dSDavid Matlack if (r) 6158ada51a9dSDavid Matlack return r; 6159ada51a9dSDavid Matlack 6160ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6161ada51a9dSDavid Matlack if (r) 6162ada51a9dSDavid Matlack return r; 6163ada51a9dSDavid Matlack 6164ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6165ada51a9dSDavid Matlack } 6166ada51a9dSDavid Matlack 6167ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6168ada51a9dSDavid Matlack { 6169ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6170ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6171ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6172ada51a9dSDavid Matlack unsigned int access; 6173ada51a9dSDavid Matlack gfn_t gfn; 6174ada51a9dSDavid Matlack 617579e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 617679e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6177ada51a9dSDavid Matlack 6178ada51a9dSDavid Matlack /* 6179ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6180ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6181ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6182ada51a9dSDavid Matlack * mapped with smaller pages. 6183ada51a9dSDavid Matlack */ 6184ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6185ada51a9dSDavid Matlack 6186ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6187ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6188ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6189ada51a9dSDavid Matlack 6190ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6191ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6192ada51a9dSDavid Matlack } 6193ada51a9dSDavid Matlack 6194ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6195ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6196ada51a9dSDavid Matlack u64 *huge_sptep) 6197ada51a9dSDavid Matlack 6198ada51a9dSDavid Matlack { 6199ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6200ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6201ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 620203787394SPaolo Bonzini bool flush = false; 6203ada51a9dSDavid Matlack u64 *sptep, spte; 6204ada51a9dSDavid Matlack gfn_t gfn; 6205ada51a9dSDavid Matlack int index; 6206ada51a9dSDavid Matlack 6207ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6208ada51a9dSDavid Matlack 6209ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6210ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6211ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6212ada51a9dSDavid Matlack 6213ada51a9dSDavid Matlack /* 6214ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6215ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6216ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6217ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6218ada51a9dSDavid Matlack * modify them. 6219ada51a9dSDavid Matlack * 622003787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 622103787394SPaolo Bonzini * that lower level page table may only be partially populated. 622203787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 622303787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 622403787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 622503787394SPaolo Bonzini * fail to detect the need to flush. 6226ada51a9dSDavid Matlack */ 622703787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 622803787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6229ada51a9dSDavid Matlack continue; 623003787394SPaolo Bonzini } 6231ada51a9dSDavid Matlack 6232ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6233ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6234ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6235ada51a9dSDavid Matlack } 6236ada51a9dSDavid Matlack 623703787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6238ada51a9dSDavid Matlack } 6239ada51a9dSDavid Matlack 6240ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6241ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6242ada51a9dSDavid Matlack u64 *huge_sptep) 6243ada51a9dSDavid Matlack { 6244ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6245ada51a9dSDavid Matlack int level, r = 0; 6246ada51a9dSDavid Matlack gfn_t gfn; 6247ada51a9dSDavid Matlack u64 spte; 6248ada51a9dSDavid Matlack 6249ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 625079e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6251ada51a9dSDavid Matlack level = huge_sp->role.level; 6252ada51a9dSDavid Matlack spte = *huge_sptep; 6253ada51a9dSDavid Matlack 6254ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6255ada51a9dSDavid Matlack r = -ENOSPC; 6256ada51a9dSDavid Matlack goto out; 6257ada51a9dSDavid Matlack } 6258ada51a9dSDavid Matlack 6259ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6260ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6261ada51a9dSDavid Matlack cond_resched(); 6262ada51a9dSDavid Matlack /* 6263ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6264ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6265ada51a9dSDavid Matlack * dropped. 6266ada51a9dSDavid Matlack */ 6267ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6268ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6269ada51a9dSDavid Matlack goto out; 6270ada51a9dSDavid Matlack } 6271ada51a9dSDavid Matlack 6272ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6273ada51a9dSDavid Matlack 6274ada51a9dSDavid Matlack out: 6275ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6276ada51a9dSDavid Matlack return r; 6277ada51a9dSDavid Matlack } 6278ada51a9dSDavid Matlack 6279ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6280ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6281ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6282ada51a9dSDavid Matlack { 6283ada51a9dSDavid Matlack struct rmap_iterator iter; 6284ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6285ada51a9dSDavid Matlack u64 *huge_sptep; 6286ada51a9dSDavid Matlack int r; 6287ada51a9dSDavid Matlack 6288ada51a9dSDavid Matlack restart: 6289ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6290ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6291ada51a9dSDavid Matlack 6292ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6293ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6294ada51a9dSDavid Matlack continue; 6295ada51a9dSDavid Matlack 6296ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6297ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6298ada51a9dSDavid Matlack continue; 6299ada51a9dSDavid Matlack 6300ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6301ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6302ada51a9dSDavid Matlack continue; 6303ada51a9dSDavid Matlack 6304ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6305ada51a9dSDavid Matlack if (sp->role.invalid) 6306ada51a9dSDavid Matlack continue; 6307ada51a9dSDavid Matlack 6308ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6309ada51a9dSDavid Matlack 6310ada51a9dSDavid Matlack /* 6311ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6312ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6313ada51a9dSDavid Matlack * back into a consistent state. 6314ada51a9dSDavid Matlack */ 6315ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6316ada51a9dSDavid Matlack goto restart; 6317ada51a9dSDavid Matlack 6318ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6319ada51a9dSDavid Matlack break; 6320ada51a9dSDavid Matlack } 6321ada51a9dSDavid Matlack 6322ada51a9dSDavid Matlack return false; 6323ada51a9dSDavid Matlack } 6324ada51a9dSDavid Matlack 6325ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6326ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6327ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6328ada51a9dSDavid Matlack int target_level) 6329ada51a9dSDavid Matlack { 6330ada51a9dSDavid Matlack int level; 6331ada51a9dSDavid Matlack 6332ada51a9dSDavid Matlack /* 6333ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6334ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6335ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6336ada51a9dSDavid Matlack * already at the target level. 6337ada51a9dSDavid Matlack */ 6338ada51a9dSDavid Matlack for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) { 6339ada51a9dSDavid Matlack slot_handle_level_range(kvm, slot, shadow_mmu_try_split_huge_pages, 6340ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6341ada51a9dSDavid Matlack } 6342ada51a9dSDavid Matlack } 6343ada51a9dSDavid Matlack 6344cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6345cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6346cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6347cb00a70bSDavid Matlack u64 start, u64 end, 6348cb00a70bSDavid Matlack int target_level) 6349cb00a70bSDavid Matlack { 6350ada51a9dSDavid Matlack if (!is_tdp_mmu_enabled(kvm)) 6351ada51a9dSDavid Matlack return; 6352ada51a9dSDavid Matlack 6353ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6354ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6355ada51a9dSDavid Matlack 6356ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6357cb00a70bSDavid Matlack 6358cb00a70bSDavid Matlack /* 6359cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6360cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6361cb00a70bSDavid Matlack */ 6362cb00a70bSDavid Matlack } 6363cb00a70bSDavid Matlack 6364a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6365a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6366a3fe5dbdSDavid Matlack int target_level) 6367a3fe5dbdSDavid Matlack { 6368a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6369a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6370a3fe5dbdSDavid Matlack 6371ada51a9dSDavid Matlack if (!is_tdp_mmu_enabled(kvm)) 6372ada51a9dSDavid Matlack return; 6373ada51a9dSDavid Matlack 6374ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6375ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6376ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6377ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6378ada51a9dSDavid Matlack } 6379ada51a9dSDavid Matlack 6380a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6381cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6382a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6383a3fe5dbdSDavid Matlack 6384a3fe5dbdSDavid Matlack /* 6385a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6386a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6387a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6388a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6389a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6390a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6391a3fe5dbdSDavid Matlack * SPTEs. 6392a3fe5dbdSDavid Matlack */ 6393a3fe5dbdSDavid Matlack } 6394a3fe5dbdSDavid Matlack 6395c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 63960a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6397269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6398c50d8ae3SPaolo Bonzini { 6399c50d8ae3SPaolo Bonzini u64 *sptep; 6400c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6401c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6402c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6403c50d8ae3SPaolo Bonzini 6404c50d8ae3SPaolo Bonzini restart: 6405c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 640657354682SSean Christopherson sp = sptep_to_sp(sptep); 6407c50d8ae3SPaolo Bonzini 6408c50d8ae3SPaolo Bonzini /* 6409c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6410c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6411c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6412c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6413c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6414c50d8ae3SPaolo Bonzini */ 64155d49f08cSSean Christopherson if (sp->role.direct && 64169eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6417a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 64189202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6419c50d8ae3SPaolo Bonzini 6420c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6421c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6422c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6423c50d8ae3SPaolo Bonzini else 6424c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6425c50d8ae3SPaolo Bonzini 6426c50d8ae3SPaolo Bonzini goto restart; 6427c50d8ae3SPaolo Bonzini } 6428c50d8ae3SPaolo Bonzini } 6429c50d8ae3SPaolo Bonzini 6430c50d8ae3SPaolo Bonzini return need_tlb_flush; 6431c50d8ae3SPaolo Bonzini } 6432c50d8ae3SPaolo Bonzini 643320d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 643420d49186SDavid Matlack const struct kvm_memory_slot *slot) 643520d49186SDavid Matlack { 643620d49186SDavid Matlack /* 643720d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 643820d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 643920d49186SDavid Matlack */ 644020d49186SDavid Matlack if (slot_handle_level(kvm, slot, kvm_mmu_zap_collapsible_spte, 644120d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 644220d49186SDavid Matlack kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 644320d49186SDavid Matlack } 644420d49186SDavid Matlack 6445c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6446269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6447c50d8ae3SPaolo Bonzini { 6448e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6449531810caSBen Gardon write_lock(&kvm->mmu_lock); 645020d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6451531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6452e2209710SBen Gardon } 64532db6f772SBen Gardon 64542db6f772SBen Gardon if (is_tdp_mmu_enabled(kvm)) { 64552db6f772SBen Gardon read_lock(&kvm->mmu_lock); 64564b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 64572db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 64582db6f772SBen Gardon } 6459c50d8ae3SPaolo Bonzini } 6460c50d8ae3SPaolo Bonzini 6461b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 64626c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6463b3594ffbSSean Christopherson { 6464b3594ffbSSean Christopherson /* 64657f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6466302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 64677f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 64687f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 64697f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6470b3594ffbSSean Christopherson */ 6471b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6472cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6473cec37648SSean Christopherson memslot->npages); 6474b3594ffbSSean Christopherson } 6475b3594ffbSSean Christopherson 6476c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6477269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6478c50d8ae3SPaolo Bonzini { 6479e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6480531810caSBen Gardon write_lock(&kvm->mmu_lock); 6481610265eaSDavid Matlack /* 6482610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6483610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6484610265eaSDavid Matlack */ 6485b64d740eSJunaid Shahid slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6486531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6487e2209710SBen Gardon } 6488c50d8ae3SPaolo Bonzini 648924ae4cfaSBen Gardon if (is_tdp_mmu_enabled(kvm)) { 649024ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6491b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 649224ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 649324ae4cfaSBen Gardon } 649424ae4cfaSBen Gardon 6495c50d8ae3SPaolo Bonzini /* 6496b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6497b64d740eSJunaid Shahid * 6498c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6499c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6500c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6501c50d8ae3SPaolo Bonzini * dirty_bitmap. 6502c50d8ae3SPaolo Bonzini */ 6503c50d8ae3SPaolo Bonzini } 6504c50d8ae3SPaolo Bonzini 6505c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6506c50d8ae3SPaolo Bonzini { 6507c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6508c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6509c50d8ae3SPaolo Bonzini int ign; 6510c50d8ae3SPaolo Bonzini 6511531810caSBen Gardon write_lock(&kvm->mmu_lock); 6512c50d8ae3SPaolo Bonzini restart: 6513c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6514f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6515c50d8ae3SPaolo Bonzini continue; 6516c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6517c50d8ae3SPaolo Bonzini goto restart; 6518531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6519c50d8ae3SPaolo Bonzini goto restart; 6520c50d8ae3SPaolo Bonzini } 6521c50d8ae3SPaolo Bonzini 6522c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6523faaf05b0SBen Gardon 6524897218ffSPaolo Bonzini if (is_tdp_mmu_enabled(kvm)) 6525faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6526faaf05b0SBen Gardon 6527531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6528c50d8ae3SPaolo Bonzini } 6529c50d8ae3SPaolo Bonzini 6530c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6531c50d8ae3SPaolo Bonzini { 6532c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6533c50d8ae3SPaolo Bonzini 6534c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6535c50d8ae3SPaolo Bonzini 6536c50d8ae3SPaolo Bonzini /* 6537c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6538c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6539c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6540c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6541c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6542c50d8ae3SPaolo Bonzini */ 6543c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6544c50d8ae3SPaolo Bonzini 6545c50d8ae3SPaolo Bonzini /* 6546c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6547c50d8ae3SPaolo Bonzini * zap all shadow pages. 6548c50d8ae3SPaolo Bonzini */ 6549c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6550c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6551c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6552c50d8ae3SPaolo Bonzini } 6553c50d8ae3SPaolo Bonzini } 6554c50d8ae3SPaolo Bonzini 6555c50d8ae3SPaolo Bonzini static unsigned long 6556c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6557c50d8ae3SPaolo Bonzini { 6558c50d8ae3SPaolo Bonzini struct kvm *kvm; 6559c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6560c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6561c50d8ae3SPaolo Bonzini 6562c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6563c50d8ae3SPaolo Bonzini 6564c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6565c50d8ae3SPaolo Bonzini int idx; 6566c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6567c50d8ae3SPaolo Bonzini 6568c50d8ae3SPaolo Bonzini /* 6569c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6570c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6571c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6572c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6573c50d8ae3SPaolo Bonzini */ 6574c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6575c50d8ae3SPaolo Bonzini break; 6576c50d8ae3SPaolo Bonzini /* 6577c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6578c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6579c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6580c50d8ae3SPaolo Bonzini * anyway. 6581c50d8ae3SPaolo Bonzini */ 6582c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6583c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6584c50d8ae3SPaolo Bonzini continue; 6585c50d8ae3SPaolo Bonzini 6586c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6587531810caSBen Gardon write_lock(&kvm->mmu_lock); 6588c50d8ae3SPaolo Bonzini 6589c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6590c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6591c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6592c50d8ae3SPaolo Bonzini goto unlock; 6593c50d8ae3SPaolo Bonzini } 6594c50d8ae3SPaolo Bonzini 6595ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6596c50d8ae3SPaolo Bonzini 6597c50d8ae3SPaolo Bonzini unlock: 6598531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6599c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6600c50d8ae3SPaolo Bonzini 6601c50d8ae3SPaolo Bonzini /* 6602c50d8ae3SPaolo Bonzini * unfair on small ones 6603c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6604c50d8ae3SPaolo Bonzini * sadness comes quickly 6605c50d8ae3SPaolo Bonzini */ 6606c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6607c50d8ae3SPaolo Bonzini break; 6608c50d8ae3SPaolo Bonzini } 6609c50d8ae3SPaolo Bonzini 6610c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6611c50d8ae3SPaolo Bonzini return freed; 6612c50d8ae3SPaolo Bonzini } 6613c50d8ae3SPaolo Bonzini 6614c50d8ae3SPaolo Bonzini static unsigned long 6615c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6616c50d8ae3SPaolo Bonzini { 6617c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6618c50d8ae3SPaolo Bonzini } 6619c50d8ae3SPaolo Bonzini 6620c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6621c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6622c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6623c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6624c50d8ae3SPaolo Bonzini }; 6625c50d8ae3SPaolo Bonzini 6626c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6627c50d8ae3SPaolo Bonzini { 6628c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6629c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6630c50d8ae3SPaolo Bonzini } 6631c50d8ae3SPaolo Bonzini 6632c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6633c50d8ae3SPaolo Bonzini { 6634c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6635c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6636c50d8ae3SPaolo Bonzini } 6637c50d8ae3SPaolo Bonzini 6638c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6639c50d8ae3SPaolo Bonzini { 6640c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6641c50d8ae3SPaolo Bonzini } 6642c50d8ae3SPaolo Bonzini 6643c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6644c50d8ae3SPaolo Bonzini { 6645c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6646c50d8ae3SPaolo Bonzini bool new_val; 6647c50d8ae3SPaolo Bonzini 6648c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6649c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6650c50d8ae3SPaolo Bonzini new_val = 0; 6651c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6652c50d8ae3SPaolo Bonzini new_val = 1; 6653c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6654c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6655c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6656c50d8ae3SPaolo Bonzini return -EINVAL; 6657c50d8ae3SPaolo Bonzini 6658c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6659c50d8ae3SPaolo Bonzini 6660c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6661c50d8ae3SPaolo Bonzini struct kvm *kvm; 6662c50d8ae3SPaolo Bonzini 6663c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6664c50d8ae3SPaolo Bonzini 6665c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6666c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6667c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6668c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6669c50d8ae3SPaolo Bonzini 6670c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6671c50d8ae3SPaolo Bonzini } 6672c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6673c50d8ae3SPaolo Bonzini } 6674c50d8ae3SPaolo Bonzini 6675c50d8ae3SPaolo Bonzini return 0; 6676c50d8ae3SPaolo Bonzini } 6677c50d8ae3SPaolo Bonzini 66781d0e8480SSean Christopherson /* 66791d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 66801d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 6681c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 6682c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 66831d0e8480SSean Christopherson */ 6684982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 6685c50d8ae3SPaolo Bonzini { 6686c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6687c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 6688c3e0c8c2SSean Christopherson 6689c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 66901d0e8480SSean Christopherson } 66911d0e8480SSean Christopherson 66921d0e8480SSean Christopherson /* 66931d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 66941d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 66951d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 66961d0e8480SSean Christopherson */ 66971d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 66981d0e8480SSean Christopherson { 66991d0e8480SSean Christopherson int ret = -ENOMEM; 6700c50d8ae3SPaolo Bonzini 6701c50d8ae3SPaolo Bonzini /* 6702c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6703c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6704c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6705c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6706c50d8ae3SPaolo Bonzini */ 6707c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6708c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 67097a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6710c50d8ae3SPaolo Bonzini 6711c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6712c50d8ae3SPaolo Bonzini 6713c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6714c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6715c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6716c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6717c50d8ae3SPaolo Bonzini goto out; 6718c50d8ae3SPaolo Bonzini 6719c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6720c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6721c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6722c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6723c50d8ae3SPaolo Bonzini goto out; 6724c50d8ae3SPaolo Bonzini 6725c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6726c50d8ae3SPaolo Bonzini goto out; 6727c50d8ae3SPaolo Bonzini 6728e33c267aSRoman Gushchin ret = register_shrinker(&mmu_shrinker, "x86-mmu"); 6729c50d8ae3SPaolo Bonzini if (ret) 6730d7c9bfb9SMiaohe Lin goto out_shrinker; 6731c50d8ae3SPaolo Bonzini 6732c50d8ae3SPaolo Bonzini return 0; 6733c50d8ae3SPaolo Bonzini 6734d7c9bfb9SMiaohe Lin out_shrinker: 6735d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 6736c50d8ae3SPaolo Bonzini out: 6737c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6738c50d8ae3SPaolo Bonzini return ret; 6739c50d8ae3SPaolo Bonzini } 6740c50d8ae3SPaolo Bonzini 6741c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6742c50d8ae3SPaolo Bonzini { 6743c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6744c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6745c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6746c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6747c50d8ae3SPaolo Bonzini } 6748c50d8ae3SPaolo Bonzini 67491d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6750c50d8ae3SPaolo Bonzini { 6751c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6752c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6753c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6754c50d8ae3SPaolo Bonzini } 6755c50d8ae3SPaolo Bonzini 6756f47491d7SSean Christopherson /* 6757f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6758f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6759f47491d7SSean Christopherson */ 6760f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6761f47491d7SSean Christopherson { 6762f47491d7SSean Christopherson /* 6763f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6764f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6765f47491d7SSean Christopherson */ 6766f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6767f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6768f47491d7SSean Christopherson 6769f47491d7SSean Christopherson if (!enabled || !ratio) 6770f47491d7SSean Christopherson return false; 6771f47491d7SSean Christopherson 6772f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6773f47491d7SSean Christopherson if (!*period) { 6774f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6775f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6776f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6777f47491d7SSean Christopherson } 6778f47491d7SSean Christopherson return true; 6779f47491d7SSean Christopherson } 6780f47491d7SSean Christopherson 67814dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6782c50d8ae3SPaolo Bonzini { 67834dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 67844dfe4f40SJunaid Shahid uint old_period, new_period; 6785c50d8ae3SPaolo Bonzini int err; 6786c50d8ae3SPaolo Bonzini 6787f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 67884dfe4f40SJunaid Shahid 6789c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6790c50d8ae3SPaolo Bonzini if (err) 6791c50d8ae3SPaolo Bonzini return err; 6792c50d8ae3SPaolo Bonzini 6793f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 67944dfe4f40SJunaid Shahid 6795f47491d7SSean Christopherson if (is_recovery_enabled && 67964dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6797c50d8ae3SPaolo Bonzini struct kvm *kvm; 6798c50d8ae3SPaolo Bonzini 6799c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6800c50d8ae3SPaolo Bonzini 6801c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 6802c50d8ae3SPaolo Bonzini wake_up_process(kvm->arch.nx_lpage_recovery_thread); 6803c50d8ae3SPaolo Bonzini 6804c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6805c50d8ae3SPaolo Bonzini } 6806c50d8ae3SPaolo Bonzini 6807c50d8ae3SPaolo Bonzini return err; 6808c50d8ae3SPaolo Bonzini } 6809c50d8ae3SPaolo Bonzini 6810c50d8ae3SPaolo Bonzini static void kvm_recover_nx_lpages(struct kvm *kvm) 6811c50d8ae3SPaolo Bonzini { 6812ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6813c50d8ae3SPaolo Bonzini int rcu_idx; 6814c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6815c50d8ae3SPaolo Bonzini unsigned int ratio; 6816c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6817048f4980SSean Christopherson bool flush = false; 6818c50d8ae3SPaolo Bonzini ulong to_zap; 6819c50d8ae3SPaolo Bonzini 6820c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6821531810caSBen Gardon write_lock(&kvm->mmu_lock); 6822c50d8ae3SPaolo Bonzini 6823bb95dfb9SSean Christopherson /* 6824bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6825bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6826bb95dfb9SSean Christopherson * callback. 6827bb95dfb9SSean Christopherson */ 6828bb95dfb9SSean Christopherson rcu_read_lock(); 6829bb95dfb9SSean Christopherson 6830c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6831ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 68327d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 68337d919c7aSSean Christopherson if (list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) 68347d919c7aSSean Christopherson break; 68357d919c7aSSean Christopherson 6836c50d8ae3SPaolo Bonzini /* 6837c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 6838c50d8ae3SPaolo Bonzini * because the number of lpage_disallowed pages is expected to 6839c50d8ae3SPaolo Bonzini * be relatively small compared to the total. 6840c50d8ae3SPaolo Bonzini */ 6841c50d8ae3SPaolo Bonzini sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages, 6842c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 6843c50d8ae3SPaolo Bonzini lpage_disallowed_link); 6844c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!sp->lpage_disallowed); 6845897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) { 6846315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 68478d1a182eSBen Gardon } else { 6848c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 6849c50d8ae3SPaolo Bonzini WARN_ON_ONCE(sp->lpage_disallowed); 685029cf0f50SBen Gardon } 6851c50d8ae3SPaolo Bonzini 6852531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6853048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6854bb95dfb9SSean Christopherson rcu_read_unlock(); 6855bb95dfb9SSean Christopherson 6856531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6857048f4980SSean Christopherson flush = false; 6858bb95dfb9SSean Christopherson 6859bb95dfb9SSean Christopherson rcu_read_lock(); 6860c50d8ae3SPaolo Bonzini } 6861c50d8ae3SPaolo Bonzini } 6862048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6863c50d8ae3SPaolo Bonzini 6864bb95dfb9SSean Christopherson rcu_read_unlock(); 6865bb95dfb9SSean Christopherson 6866531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6867c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 6868c50d8ae3SPaolo Bonzini } 6869c50d8ae3SPaolo Bonzini 6870c50d8ae3SPaolo Bonzini static long get_nx_lpage_recovery_timeout(u64 start_time) 6871c50d8ae3SPaolo Bonzini { 6872f47491d7SSean Christopherson bool enabled; 6873f47491d7SSean Christopherson uint period; 68744dfe4f40SJunaid Shahid 6875f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 68764dfe4f40SJunaid Shahid 6877f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 6878c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 6879c50d8ae3SPaolo Bonzini } 6880c50d8ae3SPaolo Bonzini 6881c50d8ae3SPaolo Bonzini static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data) 6882c50d8ae3SPaolo Bonzini { 6883c50d8ae3SPaolo Bonzini u64 start_time; 6884c50d8ae3SPaolo Bonzini long remaining_time; 6885c50d8ae3SPaolo Bonzini 6886c50d8ae3SPaolo Bonzini while (true) { 6887c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 6888c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6889c50d8ae3SPaolo Bonzini 6890c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6891c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 6892c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 6893c50d8ae3SPaolo Bonzini remaining_time = get_nx_lpage_recovery_timeout(start_time); 6894c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 6895c50d8ae3SPaolo Bonzini } 6896c50d8ae3SPaolo Bonzini 6897c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 6898c50d8ae3SPaolo Bonzini 6899c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 6900c50d8ae3SPaolo Bonzini return 0; 6901c50d8ae3SPaolo Bonzini 6902c50d8ae3SPaolo Bonzini kvm_recover_nx_lpages(kvm); 6903c50d8ae3SPaolo Bonzini } 6904c50d8ae3SPaolo Bonzini } 6905c50d8ae3SPaolo Bonzini 6906c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 6907c50d8ae3SPaolo Bonzini { 6908c50d8ae3SPaolo Bonzini int err; 6909c50d8ae3SPaolo Bonzini 6910c50d8ae3SPaolo Bonzini err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0, 6911c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 6912c50d8ae3SPaolo Bonzini &kvm->arch.nx_lpage_recovery_thread); 6913c50d8ae3SPaolo Bonzini if (!err) 6914c50d8ae3SPaolo Bonzini kthread_unpark(kvm->arch.nx_lpage_recovery_thread); 6915c50d8ae3SPaolo Bonzini 6916c50d8ae3SPaolo Bonzini return err; 6917c50d8ae3SPaolo Bonzini } 6918c50d8ae3SPaolo Bonzini 6919c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 6920c50d8ae3SPaolo Bonzini { 6921c50d8ae3SPaolo Bonzini if (kvm->arch.nx_lpage_recovery_thread) 6922c50d8ae3SPaolo Bonzini kthread_stop(kvm->arch.nx_lpage_recovery_thread); 6923c50d8ae3SPaolo Bonzini } 6924