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 1021f98f2bdSDavid Matlack bool __ro_after_init tdp_mmu_allowed; 1031f98f2bdSDavid Matlack 1041f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 1051f98f2bdSDavid Matlack bool __read_mostly tdp_mmu_enabled = true; 1061f98f2bdSDavid Matlack module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0444); 1071f98f2bdSDavid Matlack #endif 1081f98f2bdSDavid Matlack 1091d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 110746700d2SWei Huang static int tdp_root_level __read_mostly; 11183013059SSean Christopherson static int max_tdp_level __read_mostly; 112703c335dSSean Christopherson 113c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1145a9624afSPaolo Bonzini bool dbg = 0; 115c50d8ae3SPaolo Bonzini module_param(dbg, bool, 0644); 116c50d8ae3SPaolo Bonzini #endif 117c50d8ae3SPaolo Bonzini 118c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 119c50d8ae3SPaolo Bonzini 120c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 121c50d8ae3SPaolo Bonzini 122dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 12313236e25SPeter Xu #define PTE_LIST_EXT 14 124c50d8ae3SPaolo Bonzini 12513236e25SPeter Xu /* 12613236e25SPeter Xu * Slight optimization of cacheline layout, by putting `more' and `spte_count' 12713236e25SPeter Xu * at the start; then accessing it will only use one single cacheline for 12813236e25SPeter Xu * either full (entries==PTE_LIST_EXT) case or entries<=6. 12913236e25SPeter Xu */ 130c50d8ae3SPaolo Bonzini struct pte_list_desc { 131c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 13213236e25SPeter Xu /* 13313236e25SPeter Xu * Stores number of entries stored in the pte_list_desc. No need to be 13413236e25SPeter Xu * u64 but just for easier alignment. When PTE_LIST_EXT, means full. 13513236e25SPeter Xu */ 13613236e25SPeter Xu u64 spte_count; 13713236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 138c50d8ae3SPaolo Bonzini }; 139c50d8ae3SPaolo Bonzini 140c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 141c50d8ae3SPaolo Bonzini u64 addr; 142c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 143c50d8ae3SPaolo Bonzini u64 *sptep; 144c50d8ae3SPaolo Bonzini int level; 145c50d8ae3SPaolo Bonzini unsigned index; 146c50d8ae3SPaolo Bonzini }; 147c50d8ae3SPaolo Bonzini 148c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 149c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 150c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 151c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 152c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 153c50d8ae3SPaolo Bonzini 154c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 155c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 156c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 157c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 158c50d8ae3SPaolo Bonzini 159c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 160c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 161c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 162c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 163c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 164c50d8ae3SPaolo Bonzini 165c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 16602c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 167c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 168c50d8ae3SPaolo Bonzini 169c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 170c50d8ae3SPaolo Bonzini 171594e91a1SSean Christopherson struct kvm_mmu_role_regs { 172594e91a1SSean Christopherson const unsigned long cr0; 173594e91a1SSean Christopherson const unsigned long cr4; 174594e91a1SSean Christopherson const u64 efer; 175594e91a1SSean Christopherson }; 176594e91a1SSean Christopherson 177c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 178c50d8ae3SPaolo Bonzini #include "mmutrace.h" 179c50d8ae3SPaolo Bonzini 180594e91a1SSean Christopherson /* 181594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1827a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 183594e91a1SSean Christopherson * the single source of truth for the MMU's state. 184594e91a1SSean Christopherson */ 185594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 18682ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 18782ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 188594e91a1SSean Christopherson { \ 189594e91a1SSean Christopherson return !!(regs->reg & flag); \ 190594e91a1SSean Christopherson } 191594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 192594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 193594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 194594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 195594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 196594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 197594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 198594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 199594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 200594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 201594e91a1SSean Christopherson 20260667724SSean Christopherson /* 20360667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 20460667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 20560667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 20660667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 20760667724SSean Christopherson */ 20860667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2094ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 21060667724SSean Christopherson { \ 211e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 21260667724SSean Christopherson } 21360667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 21460667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 21560667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 21660667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 21760667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 21860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 21960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 22056b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 22160667724SSean Christopherson 222faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 223faf72962SPaolo Bonzini { 224faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 225faf72962SPaolo Bonzini } 226faf72962SPaolo Bonzini 227faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 228faf72962SPaolo Bonzini { 229faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 230faf72962SPaolo Bonzini } 231faf72962SPaolo Bonzini 232594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 233594e91a1SSean Christopherson { 234594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 235594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 236594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 237594e91a1SSean Christopherson .efer = vcpu->arch.efer, 238594e91a1SSean Christopherson }; 239594e91a1SSean Christopherson 240594e91a1SSean Christopherson return regs; 241594e91a1SSean Christopherson } 242c50d8ae3SPaolo Bonzini 243c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 244c50d8ae3SPaolo Bonzini { 245afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 246c50d8ae3SPaolo Bonzini } 247c50d8ae3SPaolo Bonzini 248c50d8ae3SPaolo Bonzini static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm, 249c50d8ae3SPaolo Bonzini struct kvm_tlb_range *range) 250c50d8ae3SPaolo Bonzini { 251c50d8ae3SPaolo Bonzini int ret = -ENOTSUPP; 252c50d8ae3SPaolo Bonzini 253afaf0b2fSSean Christopherson if (range && kvm_x86_ops.tlb_remote_flush_with_range) 254b3646477SJason Baron ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range); 255c50d8ae3SPaolo Bonzini 256c50d8ae3SPaolo Bonzini if (ret) 257c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 258c50d8ae3SPaolo Bonzini } 259c50d8ae3SPaolo Bonzini 2602f2fad08SBen Gardon void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 261c50d8ae3SPaolo Bonzini u64 start_gfn, u64 pages) 262c50d8ae3SPaolo Bonzini { 263c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 264c50d8ae3SPaolo Bonzini 265c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 266c50d8ae3SPaolo Bonzini range.pages = pages; 267c50d8ae3SPaolo Bonzini 268c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_range(kvm, &range); 269c50d8ae3SPaolo Bonzini } 270c50d8ae3SPaolo Bonzini 2718f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2728f79b064SBen Gardon unsigned int access) 2738f79b064SBen Gardon { 274c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2758f79b064SBen Gardon 276c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 277c236d962SSean Christopherson mmu_spte_set(sptep, spte); 278c50d8ae3SPaolo Bonzini } 279c50d8ae3SPaolo Bonzini 280c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 281c50d8ae3SPaolo Bonzini { 282c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 283c50d8ae3SPaolo Bonzini 2848a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 285c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 286c50d8ae3SPaolo Bonzini 287c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 288c50d8ae3SPaolo Bonzini } 289c50d8ae3SPaolo Bonzini 290c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 291c50d8ae3SPaolo Bonzini { 292c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 293c50d8ae3SPaolo Bonzini } 294c50d8ae3SPaolo Bonzini 295c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 296c50d8ae3SPaolo Bonzini { 297c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 298c50d8ae3SPaolo Bonzini 299c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 300c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 301c50d8ae3SPaolo Bonzini return false; 302c50d8ae3SPaolo Bonzini 303c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 304c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 305c50d8ae3SPaolo Bonzini 306c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 307c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 308c50d8ae3SPaolo Bonzini } 309c50d8ae3SPaolo Bonzini 310c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 311c50d8ae3SPaolo Bonzini { 312c50d8ae3SPaolo Bonzini return 1; 313c50d8ae3SPaolo Bonzini } 314c50d8ae3SPaolo Bonzini 315c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 316c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 317c50d8ae3SPaolo Bonzini { 318c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 319c50d8ae3SPaolo Bonzini } 320c50d8ae3SPaolo Bonzini 321c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 322c50d8ae3SPaolo Bonzini { 323c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 324c50d8ae3SPaolo Bonzini } 325c50d8ae3SPaolo Bonzini 326c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 327c50d8ae3SPaolo Bonzini { 328c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 329c50d8ae3SPaolo Bonzini } 330c50d8ae3SPaolo Bonzini 331c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 332c50d8ae3SPaolo Bonzini { 333c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 334c50d8ae3SPaolo Bonzini } 335c50d8ae3SPaolo Bonzini #else 336c50d8ae3SPaolo Bonzini union split_spte { 337c50d8ae3SPaolo Bonzini struct { 338c50d8ae3SPaolo Bonzini u32 spte_low; 339c50d8ae3SPaolo Bonzini u32 spte_high; 340c50d8ae3SPaolo Bonzini }; 341c50d8ae3SPaolo Bonzini u64 spte; 342c50d8ae3SPaolo Bonzini }; 343c50d8ae3SPaolo Bonzini 344c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 345c50d8ae3SPaolo Bonzini { 34657354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 347c50d8ae3SPaolo Bonzini 348c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 349c50d8ae3SPaolo Bonzini return; 350c50d8ae3SPaolo Bonzini 351c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 352c50d8ae3SPaolo Bonzini smp_wmb(); 353c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 354c50d8ae3SPaolo Bonzini } 355c50d8ae3SPaolo Bonzini 356c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 357c50d8ae3SPaolo Bonzini { 358c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 359c50d8ae3SPaolo Bonzini 360c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 361c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 362c50d8ae3SPaolo Bonzini 363c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 364c50d8ae3SPaolo Bonzini 365c50d8ae3SPaolo Bonzini /* 366c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 367c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 368c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 369c50d8ae3SPaolo Bonzini */ 370c50d8ae3SPaolo Bonzini smp_wmb(); 371c50d8ae3SPaolo Bonzini 372c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 373c50d8ae3SPaolo Bonzini } 374c50d8ae3SPaolo Bonzini 375c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 376c50d8ae3SPaolo Bonzini { 377c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 378c50d8ae3SPaolo Bonzini 379c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 380c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 381c50d8ae3SPaolo Bonzini 382c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 383c50d8ae3SPaolo Bonzini 384c50d8ae3SPaolo Bonzini /* 385c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 386c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 387c50d8ae3SPaolo Bonzini */ 388c50d8ae3SPaolo Bonzini smp_wmb(); 389c50d8ae3SPaolo Bonzini 390c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 391c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 392c50d8ae3SPaolo Bonzini } 393c50d8ae3SPaolo Bonzini 394c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 395c50d8ae3SPaolo Bonzini { 396c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 397c50d8ae3SPaolo Bonzini 398c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 399c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 400c50d8ae3SPaolo Bonzini 401c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 402c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 403c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 404c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 405c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 406c50d8ae3SPaolo Bonzini 407c50d8ae3SPaolo Bonzini return orig.spte; 408c50d8ae3SPaolo Bonzini } 409c50d8ae3SPaolo Bonzini 410c50d8ae3SPaolo Bonzini /* 411c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 412c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 413c50d8ae3SPaolo Bonzini * 414aed02fe3SSean Christopherson * An spte tlb flush may be pending, because kvm_set_pte_rmap 415c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 416c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 417c50d8ae3SPaolo Bonzini * 418c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 419c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 420c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 421c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 422c50d8ae3SPaolo Bonzini * 423c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 424c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 425c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 426c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 427c50d8ae3SPaolo Bonzini */ 428c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 429c50d8ae3SPaolo Bonzini { 43057354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 431c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 432c50d8ae3SPaolo Bonzini int count; 433c50d8ae3SPaolo Bonzini 434c50d8ae3SPaolo Bonzini retry: 435c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 436c50d8ae3SPaolo Bonzini smp_rmb(); 437c50d8ae3SPaolo Bonzini 438c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 439c50d8ae3SPaolo Bonzini smp_rmb(); 440c50d8ae3SPaolo Bonzini 441c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 442c50d8ae3SPaolo Bonzini smp_rmb(); 443c50d8ae3SPaolo Bonzini 444c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 445c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 446c50d8ae3SPaolo Bonzini goto retry; 447c50d8ae3SPaolo Bonzini 448c50d8ae3SPaolo Bonzini return spte.spte; 449c50d8ae3SPaolo Bonzini } 450c50d8ae3SPaolo Bonzini #endif 451c50d8ae3SPaolo Bonzini 452c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 453c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 454c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 455c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 456c50d8ae3SPaolo Bonzini * the spte. 457c50d8ae3SPaolo Bonzini */ 458c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 459c50d8ae3SPaolo Bonzini { 460c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 461c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 462c50d8ae3SPaolo Bonzini } 463c50d8ae3SPaolo Bonzini 464c50d8ae3SPaolo Bonzini /* 465c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 466c50d8ae3SPaolo Bonzini * accessed/dirty status. 467c50d8ae3SPaolo Bonzini */ 468c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 469c50d8ae3SPaolo Bonzini { 470c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 471c50d8ae3SPaolo Bonzini 472c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 473115111efSDavid Matlack check_spte_writable_invariants(new_spte); 474c50d8ae3SPaolo Bonzini 475c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 476c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 477c50d8ae3SPaolo Bonzini return old_spte; 478c50d8ae3SPaolo Bonzini } 479c50d8ae3SPaolo Bonzini 480c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 481c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 482c50d8ae3SPaolo Bonzini else 483c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 484c50d8ae3SPaolo Bonzini 485c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 486c50d8ae3SPaolo Bonzini 487c50d8ae3SPaolo Bonzini return old_spte; 488c50d8ae3SPaolo Bonzini } 489c50d8ae3SPaolo Bonzini 490c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 491c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 492c50d8ae3SPaolo Bonzini * 49302844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 49402844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 49502844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 496c50d8ae3SPaolo Bonzini * 497c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 498c50d8ae3SPaolo Bonzini */ 499c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 500c50d8ae3SPaolo Bonzini { 501c50d8ae3SPaolo Bonzini bool flush = false; 502c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 503c50d8ae3SPaolo Bonzini 504c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 505c50d8ae3SPaolo Bonzini return false; 506c50d8ae3SPaolo Bonzini 507c50d8ae3SPaolo Bonzini /* 508c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 509c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 510c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 511c50d8ae3SPaolo Bonzini */ 512706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 513c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 514c50d8ae3SPaolo Bonzini flush = true; 515c50d8ae3SPaolo Bonzini 516c50d8ae3SPaolo Bonzini /* 517c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 518c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 519c50d8ae3SPaolo Bonzini */ 520c50d8ae3SPaolo Bonzini 521c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 522c50d8ae3SPaolo Bonzini flush = true; 523c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 524c50d8ae3SPaolo Bonzini } 525c50d8ae3SPaolo Bonzini 526c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 527c50d8ae3SPaolo Bonzini flush = true; 528c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 529c50d8ae3SPaolo Bonzini } 530c50d8ae3SPaolo Bonzini 531c50d8ae3SPaolo Bonzini return flush; 532c50d8ae3SPaolo Bonzini } 533c50d8ae3SPaolo Bonzini 534c50d8ae3SPaolo Bonzini /* 535c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 536c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 537c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5387fa2a347SSean Christopherson * Returns the old PTE. 539c50d8ae3SPaolo Bonzini */ 54035d539c3SSean Christopherson static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 541c50d8ae3SPaolo Bonzini { 542c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 543c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 54471f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 545b14b2690SSean Christopherson struct page *page; 546c50d8ae3SPaolo Bonzini 54754eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 54854eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 549c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 550c50d8ae3SPaolo Bonzini else 551c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 552c50d8ae3SPaolo Bonzini 553c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5547fa2a347SSean Christopherson return old_spte; 555c50d8ae3SPaolo Bonzini 55671f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 55771f51d2cSMingwei Zhang 558c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 559c50d8ae3SPaolo Bonzini 560c50d8ae3SPaolo Bonzini /* 561b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 562b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 563b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 564b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 565c50d8ae3SPaolo Bonzini */ 566b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 567b14b2690SSean Christopherson WARN_ON(page && !page_count(page)); 568c50d8ae3SPaolo Bonzini 569c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 570c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 571c50d8ae3SPaolo Bonzini 572c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 573c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 574c50d8ae3SPaolo Bonzini 5757fa2a347SSean Christopherson return old_spte; 576c50d8ae3SPaolo Bonzini } 577c50d8ae3SPaolo Bonzini 578c50d8ae3SPaolo Bonzini /* 579c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 580c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 581c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 582c50d8ae3SPaolo Bonzini */ 583c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 584c50d8ae3SPaolo Bonzini { 585c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 586c50d8ae3SPaolo Bonzini } 587c50d8ae3SPaolo Bonzini 588c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 589c50d8ae3SPaolo Bonzini { 590c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 591c50d8ae3SPaolo Bonzini } 592c50d8ae3SPaolo Bonzini 593c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 594c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 595c50d8ae3SPaolo Bonzini { 596c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 597c50d8ae3SPaolo Bonzini 598c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 599c50d8ae3SPaolo Bonzini return false; 600c50d8ae3SPaolo Bonzini 601c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 602c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 603c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 604c50d8ae3SPaolo Bonzini } else { 605c50d8ae3SPaolo Bonzini /* 606c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 607c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 608c50d8ae3SPaolo Bonzini */ 609c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 610c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 611c50d8ae3SPaolo Bonzini 612c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 613c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 614c50d8ae3SPaolo Bonzini } 615c50d8ae3SPaolo Bonzini 616c50d8ae3SPaolo Bonzini return true; 617c50d8ae3SPaolo Bonzini } 618c50d8ae3SPaolo Bonzini 619c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 620c50d8ae3SPaolo Bonzini { 621c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 622c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 623c5c8c7c5SDavid Matlack } else { 624c50d8ae3SPaolo Bonzini /* 625c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 626c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 627c50d8ae3SPaolo Bonzini */ 628c50d8ae3SPaolo Bonzini local_irq_disable(); 629c50d8ae3SPaolo Bonzini 630c50d8ae3SPaolo Bonzini /* 631c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 632c50d8ae3SPaolo Bonzini * to vcpu->mode. 633c50d8ae3SPaolo Bonzini */ 634c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 635c50d8ae3SPaolo Bonzini } 636c5c8c7c5SDavid Matlack } 637c50d8ae3SPaolo Bonzini 638c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 639c50d8ae3SPaolo Bonzini { 640c5c8c7c5SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) { 641c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 642c5c8c7c5SDavid Matlack } else { 643c50d8ae3SPaolo Bonzini /* 644c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 645c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 646c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 647c50d8ae3SPaolo Bonzini */ 648c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 649c50d8ae3SPaolo Bonzini local_irq_enable(); 650c50d8ae3SPaolo Bonzini } 651c5c8c7c5SDavid Matlack } 652c50d8ae3SPaolo Bonzini 653378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 654c50d8ae3SPaolo Bonzini { 655c50d8ae3SPaolo Bonzini int r; 656c50d8ae3SPaolo Bonzini 657531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 65894ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 659531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 660c50d8ae3SPaolo Bonzini if (r) 661c50d8ae3SPaolo Bonzini return r; 66294ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 663171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 664171a90d7SSean Christopherson if (r) 665171a90d7SSean Christopherson return r; 666378f5cd6SSean Christopherson if (maybe_indirect) { 6676a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 668171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 669c50d8ae3SPaolo Bonzini if (r) 670c50d8ae3SPaolo Bonzini return r; 671378f5cd6SSean Christopherson } 67294ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 673531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 674c50d8ae3SPaolo Bonzini } 675c50d8ae3SPaolo Bonzini 676c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 677c50d8ae3SPaolo Bonzini { 67894ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 67994ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 6806a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 68194ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 682c50d8ae3SPaolo Bonzini } 683c50d8ae3SPaolo Bonzini 684c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 685c50d8ae3SPaolo Bonzini { 686c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 687c50d8ae3SPaolo Bonzini } 688c50d8ae3SPaolo Bonzini 6896a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 6906a97575dSDavid Matlack 691c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 692c50d8ae3SPaolo Bonzini { 69384e5ffd0SLai Jiangshan if (sp->role.passthrough) 69484e5ffd0SLai Jiangshan return sp->gfn; 69584e5ffd0SLai Jiangshan 696c50d8ae3SPaolo Bonzini if (!sp->role.direct) 6976a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 698c50d8ae3SPaolo Bonzini 6992ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 700c50d8ae3SPaolo Bonzini } 701c50d8ae3SPaolo Bonzini 7026a97575dSDavid Matlack /* 7036a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 7046a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 7056a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 7066a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 7076a97575dSDavid Matlack */ 7086a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 709c50d8ae3SPaolo Bonzini { 7106a97575dSDavid Matlack if (sp_has_gptes(sp)) 7116a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7126a97575dSDavid Matlack 7136a97575dSDavid Matlack /* 7146a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7156a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7166a97575dSDavid Matlack * permissions" are just ACC_ALL. 7176a97575dSDavid Matlack * 7186a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7196a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7206a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7216a97575dSDavid Matlack * page. 7226a97575dSDavid Matlack * 7236a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7246a97575dSDavid Matlack */ 7256a97575dSDavid Matlack return sp->role.access; 7266a97575dSDavid Matlack } 7276a97575dSDavid Matlack 72872ae5822SSean Christopherson static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, 72972ae5822SSean Christopherson gfn_t gfn, unsigned int access) 7306a97575dSDavid Matlack { 7316a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7326a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 73384e5ffd0SLai Jiangshan return; 73484e5ffd0SLai Jiangshan } 73584e5ffd0SLai Jiangshan 7366a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7376a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7386a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7396a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7406a97575dSDavid Matlack 7416a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7426a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7436a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7446a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 745c50d8ae3SPaolo Bonzini } 746c50d8ae3SPaolo Bonzini 74772ae5822SSean Christopherson static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, 74872ae5822SSean Christopherson unsigned int access) 7496a97575dSDavid Matlack { 7506a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7516a97575dSDavid Matlack 7526a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 753c50d8ae3SPaolo Bonzini } 754c50d8ae3SPaolo Bonzini 755c50d8ae3SPaolo Bonzini /* 756c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 757c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 758c50d8ae3SPaolo Bonzini */ 759c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7608ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 761c50d8ae3SPaolo Bonzini { 762c50d8ae3SPaolo Bonzini unsigned long idx; 763c50d8ae3SPaolo Bonzini 764c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 765c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 766c50d8ae3SPaolo Bonzini } 767c50d8ae3SPaolo Bonzini 768269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 769c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 770c50d8ae3SPaolo Bonzini { 771c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 772c50d8ae3SPaolo Bonzini int i; 773c50d8ae3SPaolo Bonzini 7743bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 775c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 776c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 777c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 778c50d8ae3SPaolo Bonzini } 779c50d8ae3SPaolo Bonzini } 780c50d8ae3SPaolo Bonzini 781269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 782c50d8ae3SPaolo Bonzini { 783c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 784c50d8ae3SPaolo Bonzini } 785c50d8ae3SPaolo Bonzini 786269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 787c50d8ae3SPaolo Bonzini { 788c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 789c50d8ae3SPaolo Bonzini } 790c50d8ae3SPaolo Bonzini 791c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 792c50d8ae3SPaolo Bonzini { 793c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 794c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 795c50d8ae3SPaolo Bonzini gfn_t gfn; 796c50d8ae3SPaolo Bonzini 797c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 798c50d8ae3SPaolo Bonzini gfn = sp->gfn; 799c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 800c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 801c50d8ae3SPaolo Bonzini 802c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8033bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 804c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 805c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 806c50d8ae3SPaolo Bonzini 807c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 808be911771SDavid Matlack 809be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 810be911771SDavid Matlack kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 811c50d8ae3SPaolo Bonzini } 812c50d8ae3SPaolo Bonzini 81361f94478SSean Christopherson void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 814c50d8ae3SPaolo Bonzini { 815428e9216SSean Christopherson /* 816428e9216SSean Christopherson * If it's possible to replace the shadow page with an NX huge page, 817428e9216SSean Christopherson * i.e. if the shadow page is the only thing currently preventing KVM 818428e9216SSean Christopherson * from using a huge page, add the shadow page to the list of "to be 819428e9216SSean Christopherson * zapped for NX recovery" pages. Note, the shadow page can already be 820428e9216SSean Christopherson * on the list if KVM is reusing an existing shadow page, i.e. if KVM 821428e9216SSean Christopherson * links a shadow page at multiple points. 822428e9216SSean Christopherson */ 82361f94478SSean Christopherson if (!list_empty(&sp->possible_nx_huge_page_link)) 824c50d8ae3SPaolo Bonzini return; 825c50d8ae3SPaolo Bonzini 826c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 82755c510e2SSean Christopherson list_add_tail(&sp->possible_nx_huge_page_link, 82855c510e2SSean Christopherson &kvm->arch.possible_nx_huge_pages); 829c50d8ae3SPaolo Bonzini } 830c50d8ae3SPaolo Bonzini 83161f94478SSean Christopherson static void account_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp, 83261f94478SSean Christopherson bool nx_huge_page_possible) 83361f94478SSean Christopherson { 83461f94478SSean Christopherson sp->nx_huge_page_disallowed = true; 83561f94478SSean Christopherson 83661f94478SSean Christopherson if (nx_huge_page_possible) 83761f94478SSean Christopherson track_possible_nx_huge_page(kvm, sp); 83861f94478SSean Christopherson } 83961f94478SSean Christopherson 840c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 841c50d8ae3SPaolo Bonzini { 842c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 843c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 844c50d8ae3SPaolo Bonzini gfn_t gfn; 845c50d8ae3SPaolo Bonzini 846c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 847c50d8ae3SPaolo Bonzini gfn = sp->gfn; 848c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 849c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8503bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 851c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 852c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 853c50d8ae3SPaolo Bonzini 854c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 855c50d8ae3SPaolo Bonzini } 856c50d8ae3SPaolo Bonzini 85761f94478SSean Christopherson void untrack_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 858c50d8ae3SPaolo Bonzini { 85955c510e2SSean Christopherson if (list_empty(&sp->possible_nx_huge_page_link)) 860428e9216SSean Christopherson return; 861428e9216SSean Christopherson 862428e9216SSean Christopherson --kvm->stat.nx_lpage_splits; 86355c510e2SSean Christopherson list_del_init(&sp->possible_nx_huge_page_link); 864c50d8ae3SPaolo Bonzini } 865c50d8ae3SPaolo Bonzini 86661f94478SSean Christopherson static void unaccount_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 86761f94478SSean Christopherson { 86861f94478SSean Christopherson sp->nx_huge_page_disallowed = false; 86961f94478SSean Christopherson 87061f94478SSean Christopherson untrack_possible_nx_huge_page(kvm, sp); 87161f94478SSean Christopherson } 87261f94478SSean Christopherson 873c50d8ae3SPaolo Bonzini static struct kvm_memory_slot * 874c50d8ae3SPaolo Bonzini gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, 875c50d8ae3SPaolo Bonzini bool no_dirty_log) 876c50d8ae3SPaolo Bonzini { 877c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 878c50d8ae3SPaolo Bonzini 879c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 88091b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 88191b0d268SPaolo Bonzini return NULL; 882044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 88391b0d268SPaolo Bonzini return NULL; 884c50d8ae3SPaolo Bonzini 885c50d8ae3SPaolo Bonzini return slot; 886c50d8ae3SPaolo Bonzini } 887c50d8ae3SPaolo Bonzini 888c50d8ae3SPaolo Bonzini /* 889c50d8ae3SPaolo Bonzini * About rmap_head encoding: 890c50d8ae3SPaolo Bonzini * 891c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 892c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 893c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 894c50d8ae3SPaolo Bonzini */ 895c50d8ae3SPaolo Bonzini 896c50d8ae3SPaolo Bonzini /* 897c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 898c50d8ae3SPaolo Bonzini */ 8992ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 900c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 901c50d8ae3SPaolo Bonzini { 902c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 90313236e25SPeter Xu int count = 0; 904c50d8ae3SPaolo Bonzini 905c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 906805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 907c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 908c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 909805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 9102ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 911c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 912c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 91313236e25SPeter Xu desc->spte_count = 2; 914c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 915c50d8ae3SPaolo Bonzini ++count; 916c50d8ae3SPaolo Bonzini } else { 917805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 918c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 91913236e25SPeter Xu while (desc->spte_count == PTE_LIST_EXT) { 920c50d8ae3SPaolo Bonzini count += PTE_LIST_EXT; 921c6c4f961SLi RongQing if (!desc->more) { 9222ff9039aSDavid Matlack desc->more = kvm_mmu_memory_cache_alloc(cache); 923c50d8ae3SPaolo Bonzini desc = desc->more; 92413236e25SPeter Xu desc->spte_count = 0; 925c6c4f961SLi RongQing break; 926c6c4f961SLi RongQing } 927c6c4f961SLi RongQing desc = desc->more; 928c50d8ae3SPaolo Bonzini } 92913236e25SPeter Xu count += desc->spte_count; 93013236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 931c50d8ae3SPaolo Bonzini } 932c50d8ae3SPaolo Bonzini return count; 933c50d8ae3SPaolo Bonzini } 934c50d8ae3SPaolo Bonzini 935c50d8ae3SPaolo Bonzini static void 936c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 937c50d8ae3SPaolo Bonzini struct pte_list_desc *desc, int i, 938c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc) 939c50d8ae3SPaolo Bonzini { 94013236e25SPeter Xu int j = desc->spte_count - 1; 941c50d8ae3SPaolo Bonzini 942c50d8ae3SPaolo Bonzini desc->sptes[i] = desc->sptes[j]; 943c50d8ae3SPaolo Bonzini desc->sptes[j] = NULL; 94413236e25SPeter Xu desc->spte_count--; 94513236e25SPeter Xu if (desc->spte_count) 946c50d8ae3SPaolo Bonzini return; 947c50d8ae3SPaolo Bonzini if (!prev_desc && !desc->more) 948fe3c2b4cSMiaohe Lin rmap_head->val = 0; 949c50d8ae3SPaolo Bonzini else 950c50d8ae3SPaolo Bonzini if (prev_desc) 951c50d8ae3SPaolo Bonzini prev_desc->more = desc->more; 952c50d8ae3SPaolo Bonzini else 953c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc->more | 1; 954c50d8ae3SPaolo Bonzini mmu_free_pte_list_desc(desc); 955c50d8ae3SPaolo Bonzini } 956c50d8ae3SPaolo Bonzini 9573c2e1037SSean Christopherson static void pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 958c50d8ae3SPaolo Bonzini { 959c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 960c50d8ae3SPaolo Bonzini struct pte_list_desc *prev_desc; 961c50d8ae3SPaolo Bonzini int i; 962c50d8ae3SPaolo Bonzini 963c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 964c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 965c50d8ae3SPaolo Bonzini BUG(); 966c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 967805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 968c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 969c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 970c50d8ae3SPaolo Bonzini BUG(); 971c50d8ae3SPaolo Bonzini } 972c50d8ae3SPaolo Bonzini rmap_head->val = 0; 973c50d8ae3SPaolo Bonzini } else { 974805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 975c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 976c50d8ae3SPaolo Bonzini prev_desc = NULL; 977c50d8ae3SPaolo Bonzini while (desc) { 97813236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 979c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 980c50d8ae3SPaolo Bonzini pte_list_desc_remove_entry(rmap_head, 981c50d8ae3SPaolo Bonzini desc, i, prev_desc); 982c50d8ae3SPaolo Bonzini return; 983c50d8ae3SPaolo Bonzini } 984c50d8ae3SPaolo Bonzini } 985c50d8ae3SPaolo Bonzini prev_desc = desc; 986c50d8ae3SPaolo Bonzini desc = desc->more; 987c50d8ae3SPaolo Bonzini } 988c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 989c50d8ae3SPaolo Bonzini BUG(); 990c50d8ae3SPaolo Bonzini } 991c50d8ae3SPaolo Bonzini } 992c50d8ae3SPaolo Bonzini 9939202aee8SSean Christopherson static void kvm_zap_one_rmap_spte(struct kvm *kvm, 9949202aee8SSean Christopherson struct kvm_rmap_head *rmap_head, u64 *sptep) 995c50d8ae3SPaolo Bonzini { 99671f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 9973c2e1037SSean Christopherson pte_list_remove(sptep, rmap_head); 998c50d8ae3SPaolo Bonzini } 999c50d8ae3SPaolo Bonzini 10009202aee8SSean Christopherson /* Return true if at least one SPTE was zapped, false otherwise */ 10019202aee8SSean Christopherson static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 10029202aee8SSean Christopherson struct kvm_rmap_head *rmap_head) 1003a75b5404SPeter Xu { 1004a75b5404SPeter Xu struct pte_list_desc *desc, *next; 1005a75b5404SPeter Xu int i; 1006a75b5404SPeter Xu 1007a75b5404SPeter Xu if (!rmap_head->val) 1008a75b5404SPeter Xu return false; 1009a75b5404SPeter Xu 1010a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 101171f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 1012a75b5404SPeter Xu goto out; 1013a75b5404SPeter Xu } 1014a75b5404SPeter Xu 1015a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1016a75b5404SPeter Xu 1017a75b5404SPeter Xu for (; desc; desc = next) { 1018a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 101971f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 1020a75b5404SPeter Xu next = desc->more; 1021a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 1022a75b5404SPeter Xu } 1023a75b5404SPeter Xu out: 1024a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 1025a75b5404SPeter Xu rmap_head->val = 0; 1026a75b5404SPeter Xu return true; 1027a75b5404SPeter Xu } 1028a75b5404SPeter Xu 10293bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10303bcd0662SPeter Xu { 10313bcd0662SPeter Xu struct pte_list_desc *desc; 10323bcd0662SPeter Xu unsigned int count = 0; 10333bcd0662SPeter Xu 10343bcd0662SPeter Xu if (!rmap_head->val) 10353bcd0662SPeter Xu return 0; 10363bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10373bcd0662SPeter Xu return 1; 10383bcd0662SPeter Xu 10393bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 10403bcd0662SPeter Xu 10413bcd0662SPeter Xu while (desc) { 10423bcd0662SPeter Xu count += desc->spte_count; 10433bcd0662SPeter Xu desc = desc->more; 10443bcd0662SPeter Xu } 10453bcd0662SPeter Xu 10463bcd0662SPeter Xu return count; 10473bcd0662SPeter Xu } 10483bcd0662SPeter Xu 104993e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1050269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1051c50d8ae3SPaolo Bonzini { 1052c50d8ae3SPaolo Bonzini unsigned long idx; 1053c50d8ae3SPaolo Bonzini 1054c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10553bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1056c50d8ae3SPaolo Bonzini } 1057c50d8ae3SPaolo Bonzini 1058c50d8ae3SPaolo Bonzini static bool rmap_can_add(struct kvm_vcpu *vcpu) 1059c50d8ae3SPaolo Bonzini { 1060356ec69aSSean Christopherson struct kvm_mmu_memory_cache *mc; 1061c50d8ae3SPaolo Bonzini 1062356ec69aSSean Christopherson mc = &vcpu->arch.mmu_pte_list_desc_cache; 106394ce87efSSean Christopherson return kvm_mmu_memory_cache_nr_free_objects(mc); 1064c50d8ae3SPaolo Bonzini } 1065c50d8ae3SPaolo Bonzini 1066c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1067c50d8ae3SPaolo Bonzini { 1068601f8af0SDavid Matlack struct kvm_memslots *slots; 1069601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1070c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1071c50d8ae3SPaolo Bonzini gfn_t gfn; 1072c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1073c50d8ae3SPaolo Bonzini 107457354682SSean Christopherson sp = sptep_to_sp(spte); 107579e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(spte)); 1076601f8af0SDavid Matlack 1077601f8af0SDavid Matlack /* 107868be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 107968be1306SDavid Matlack * so we have to determine which memslots to use based on context 108068be1306SDavid Matlack * information in sp->role. 1081601f8af0SDavid Matlack */ 1082601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1083601f8af0SDavid Matlack 1084601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 108593e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1086601f8af0SDavid Matlack 10873c2e1037SSean Christopherson pte_list_remove(spte, rmap_head); 1088c50d8ae3SPaolo Bonzini } 1089c50d8ae3SPaolo Bonzini 1090c50d8ae3SPaolo Bonzini /* 1091c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1092c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1093c50d8ae3SPaolo Bonzini */ 1094c50d8ae3SPaolo Bonzini struct rmap_iterator { 1095c50d8ae3SPaolo Bonzini /* private fields */ 1096c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1097c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1098c50d8ae3SPaolo Bonzini }; 1099c50d8ae3SPaolo Bonzini 1100c50d8ae3SPaolo Bonzini /* 1101c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1102c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 11030a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1104c50d8ae3SPaolo Bonzini * 1105c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1106c50d8ae3SPaolo Bonzini */ 1107c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1108c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1109c50d8ae3SPaolo Bonzini { 1110c50d8ae3SPaolo Bonzini u64 *sptep; 1111c50d8ae3SPaolo Bonzini 1112c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1113c50d8ae3SPaolo Bonzini return NULL; 1114c50d8ae3SPaolo Bonzini 1115c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1116c50d8ae3SPaolo Bonzini iter->desc = NULL; 1117c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1118c50d8ae3SPaolo Bonzini goto out; 1119c50d8ae3SPaolo Bonzini } 1120c50d8ae3SPaolo Bonzini 1121c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1122c50d8ae3SPaolo Bonzini iter->pos = 0; 1123c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1124c50d8ae3SPaolo Bonzini out: 1125c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1126c50d8ae3SPaolo Bonzini return sptep; 1127c50d8ae3SPaolo Bonzini } 1128c50d8ae3SPaolo Bonzini 1129c50d8ae3SPaolo Bonzini /* 1130c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1131c50d8ae3SPaolo Bonzini * 1132c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1133c50d8ae3SPaolo Bonzini */ 1134c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1135c50d8ae3SPaolo Bonzini { 1136c50d8ae3SPaolo Bonzini u64 *sptep; 1137c50d8ae3SPaolo Bonzini 1138c50d8ae3SPaolo Bonzini if (iter->desc) { 1139c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1140c50d8ae3SPaolo Bonzini ++iter->pos; 1141c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1142c50d8ae3SPaolo Bonzini if (sptep) 1143c50d8ae3SPaolo Bonzini goto out; 1144c50d8ae3SPaolo Bonzini } 1145c50d8ae3SPaolo Bonzini 1146c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1147c50d8ae3SPaolo Bonzini 1148c50d8ae3SPaolo Bonzini if (iter->desc) { 1149c50d8ae3SPaolo Bonzini iter->pos = 0; 1150c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1151c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1152c50d8ae3SPaolo Bonzini goto out; 1153c50d8ae3SPaolo Bonzini } 1154c50d8ae3SPaolo Bonzini } 1155c50d8ae3SPaolo Bonzini 1156c50d8ae3SPaolo Bonzini return NULL; 1157c50d8ae3SPaolo Bonzini out: 1158c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1159c50d8ae3SPaolo Bonzini return sptep; 1160c50d8ae3SPaolo Bonzini } 1161c50d8ae3SPaolo Bonzini 1162c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1163c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1164c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1165c50d8ae3SPaolo Bonzini 1166c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1167c50d8ae3SPaolo Bonzini { 116871f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11697fa2a347SSean Christopherson 11707fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1171c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1172c50d8ae3SPaolo Bonzini } 1173c50d8ae3SPaolo Bonzini 117403787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1175c50d8ae3SPaolo Bonzini { 11760cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 11770cd8dc73SPaolo Bonzini 11780cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 11790cd8dc73SPaolo Bonzini WARN_ON(sp->role.level == PG_LEVEL_4K); 11800cd8dc73SPaolo Bonzini 1181c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 118203787394SPaolo Bonzini 118303787394SPaolo Bonzini if (flush) 11840cd8dc73SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 1185c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 1186c50d8ae3SPaolo Bonzini } 1187c50d8ae3SPaolo Bonzini 1188c50d8ae3SPaolo Bonzini /* 1189c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1190c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1191c50d8ae3SPaolo Bonzini * 1192c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1193c50d8ae3SPaolo Bonzini * protection: 1194c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1195c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1196c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1197c50d8ae3SPaolo Bonzini * shadow page. 1198c50d8ae3SPaolo Bonzini * 1199c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1200c50d8ae3SPaolo Bonzini */ 1201c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1202c50d8ae3SPaolo Bonzini { 1203c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1204c50d8ae3SPaolo Bonzini 1205c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1206706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1207c50d8ae3SPaolo Bonzini return false; 1208c50d8ae3SPaolo Bonzini 1209805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1210c50d8ae3SPaolo Bonzini 1211c50d8ae3SPaolo Bonzini if (pt_protect) 12125fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1213c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1214c50d8ae3SPaolo Bonzini 1215c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1216c50d8ae3SPaolo Bonzini } 1217c50d8ae3SPaolo Bonzini 12181346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1219c50d8ae3SPaolo Bonzini bool pt_protect) 1220c50d8ae3SPaolo Bonzini { 1221c50d8ae3SPaolo Bonzini u64 *sptep; 1222c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1223c50d8ae3SPaolo Bonzini bool flush = false; 1224c50d8ae3SPaolo Bonzini 1225c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1226c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1227c50d8ae3SPaolo Bonzini 1228c50d8ae3SPaolo Bonzini return flush; 1229c50d8ae3SPaolo Bonzini } 1230c50d8ae3SPaolo Bonzini 1231c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1232c50d8ae3SPaolo Bonzini { 1233c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1234c50d8ae3SPaolo Bonzini 1235805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1236c50d8ae3SPaolo Bonzini 1237c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1238c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1239c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1240c50d8ae3SPaolo Bonzini } 1241c50d8ae3SPaolo Bonzini 1242c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1243c50d8ae3SPaolo Bonzini { 1244c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1245c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1246c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1247c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1248c50d8ae3SPaolo Bonzini 1249c50d8ae3SPaolo Bonzini return was_writable; 1250c50d8ae3SPaolo Bonzini } 1251c50d8ae3SPaolo Bonzini 1252c50d8ae3SPaolo Bonzini /* 1253c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1254c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1255c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1256c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1257c50d8ae3SPaolo Bonzini */ 12580a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1259269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1260c50d8ae3SPaolo Bonzini { 1261c50d8ae3SPaolo Bonzini u64 *sptep; 1262c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1263c50d8ae3SPaolo Bonzini bool flush = false; 1264c50d8ae3SPaolo Bonzini 1265c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1266c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1267c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1268c50d8ae3SPaolo Bonzini else 1269c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1270c50d8ae3SPaolo Bonzini 1271c50d8ae3SPaolo Bonzini return flush; 1272c50d8ae3SPaolo Bonzini } 1273c50d8ae3SPaolo Bonzini 1274c50d8ae3SPaolo Bonzini /** 1275c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1276c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1277c50d8ae3SPaolo Bonzini * @slot: slot to protect 1278c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1279c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1280c50d8ae3SPaolo Bonzini * 128189212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1282c50d8ae3SPaolo Bonzini */ 1283c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1284c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1285c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1286c50d8ae3SPaolo Bonzini { 1287c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1288c50d8ae3SPaolo Bonzini 12891f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1290a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1291a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1292e2209710SBen Gardon 1293e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1294e2209710SBen Gardon return; 1295e2209710SBen Gardon 1296c50d8ae3SPaolo Bonzini while (mask) { 129793e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 12983bae0459SSean Christopherson PG_LEVEL_4K, slot); 12991346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1300c50d8ae3SPaolo Bonzini 1301c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1302c50d8ae3SPaolo Bonzini mask &= mask - 1; 1303c50d8ae3SPaolo Bonzini } 1304c50d8ae3SPaolo Bonzini } 1305c50d8ae3SPaolo Bonzini 1306c50d8ae3SPaolo Bonzini /** 1307c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1308c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1309c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1310c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1311c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1312c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1313c50d8ae3SPaolo Bonzini * 1314c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1315c50d8ae3SPaolo Bonzini */ 1316a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1317c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1318c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1319c50d8ae3SPaolo Bonzini { 1320c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1321c50d8ae3SPaolo Bonzini 13221f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1323a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1324a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1325e2209710SBen Gardon 1326e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1327e2209710SBen Gardon return; 1328e2209710SBen Gardon 1329c50d8ae3SPaolo Bonzini while (mask) { 133093e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13313bae0459SSean Christopherson PG_LEVEL_4K, slot); 13320a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1333c50d8ae3SPaolo Bonzini 1334c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1335c50d8ae3SPaolo Bonzini mask &= mask - 1; 1336c50d8ae3SPaolo Bonzini } 1337c50d8ae3SPaolo Bonzini } 1338c50d8ae3SPaolo Bonzini 1339c50d8ae3SPaolo Bonzini /** 1340c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1341c50d8ae3SPaolo Bonzini * PT level pages. 1342c50d8ae3SPaolo Bonzini * 1343c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1344c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1345c50d8ae3SPaolo Bonzini * 134689212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 134789212919SKeqian Zhu * have such mappings. 1348c50d8ae3SPaolo Bonzini */ 1349c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1350c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1351c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1352c50d8ae3SPaolo Bonzini { 135389212919SKeqian Zhu /* 135489212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 135589212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 135689212919SKeqian Zhu * are split to 4K on the first write. 135789212919SKeqian Zhu * 135889212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 135989212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 136089212919SKeqian Zhu * pages. 136189212919SKeqian Zhu */ 136289212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 136389212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 136489212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 136589212919SKeqian Zhu 1366cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1367cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1368cb00a70bSDavid Matlack 136989212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 137089212919SKeqian Zhu 137189212919SKeqian Zhu /* Cross two large pages? */ 137289212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 137389212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 137489212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 137589212919SKeqian Zhu PG_LEVEL_2M); 137689212919SKeqian Zhu } 137789212919SKeqian Zhu 137889212919SKeqian Zhu /* Now handle 4K PTEs. */ 1379a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1380a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1381c50d8ae3SPaolo Bonzini else 1382c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1383c50d8ae3SPaolo Bonzini } 1384c50d8ae3SPaolo Bonzini 1385fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1386fb04a1edSPeter Xu { 13876dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1388fb04a1edSPeter Xu } 1389fb04a1edSPeter Xu 1390c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 13913ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 13923ad93562SKeqian Zhu int min_level) 1393c50d8ae3SPaolo Bonzini { 1394c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1395c50d8ae3SPaolo Bonzini int i; 1396c50d8ae3SPaolo Bonzini bool write_protected = false; 1397c50d8ae3SPaolo Bonzini 1398e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 13993ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 140093e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 14011346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1402c50d8ae3SPaolo Bonzini } 1403e2209710SBen Gardon } 1404c50d8ae3SPaolo Bonzini 14051f98f2bdSDavid Matlack if (tdp_mmu_enabled) 140646044f72SBen Gardon write_protected |= 14073ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 140846044f72SBen Gardon 1409c50d8ae3SPaolo Bonzini return write_protected; 1410c50d8ae3SPaolo Bonzini } 1411c50d8ae3SPaolo Bonzini 1412cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1413c50d8ae3SPaolo Bonzini { 1414c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1415c50d8ae3SPaolo Bonzini 1416c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 14173ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1418c50d8ae3SPaolo Bonzini } 1419c50d8ae3SPaolo Bonzini 1420f8480721SSean Christopherson static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1421269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1422c50d8ae3SPaolo Bonzini { 14239202aee8SSean Christopherson return kvm_zap_all_rmap_sptes(kvm, rmap_head); 1424c50d8ae3SPaolo Bonzini } 1425c50d8ae3SPaolo Bonzini 1426f8480721SSean Christopherson static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1427c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14283039bcc7SSean Christopherson pte_t unused) 1429c50d8ae3SPaolo Bonzini { 1430f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1431c50d8ae3SPaolo Bonzini } 1432c50d8ae3SPaolo Bonzini 1433aed02fe3SSean Christopherson static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1434c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14353039bcc7SSean Christopherson pte_t pte) 1436c50d8ae3SPaolo Bonzini { 1437c50d8ae3SPaolo Bonzini u64 *sptep; 1438c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 143998a26b69SVihas Mak bool need_flush = false; 1440c50d8ae3SPaolo Bonzini u64 new_spte; 1441c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1442c50d8ae3SPaolo Bonzini 14433039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14443039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1445c50d8ae3SPaolo Bonzini 1446c50d8ae3SPaolo Bonzini restart: 1447c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1448805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1449c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1450c50d8ae3SPaolo Bonzini 145198a26b69SVihas Mak need_flush = true; 1452c50d8ae3SPaolo Bonzini 14533039bcc7SSean Christopherson if (pte_write(pte)) { 14549202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 1455c50d8ae3SPaolo Bonzini goto restart; 1456c50d8ae3SPaolo Bonzini } else { 1457cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1458cb3eedabSPaolo Bonzini *sptep, new_pfn); 1459c50d8ae3SPaolo Bonzini 146071f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1461c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1462c50d8ae3SPaolo Bonzini } 1463c50d8ae3SPaolo Bonzini } 1464c50d8ae3SPaolo Bonzini 1465c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 1466c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); 146798a26b69SVihas Mak return false; 1468c50d8ae3SPaolo Bonzini } 1469c50d8ae3SPaolo Bonzini 1470c50d8ae3SPaolo Bonzini return need_flush; 1471c50d8ae3SPaolo Bonzini } 1472c50d8ae3SPaolo Bonzini 1473c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1474c50d8ae3SPaolo Bonzini /* input fields. */ 1475269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1476c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1477c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1478c50d8ae3SPaolo Bonzini int start_level; 1479c50d8ae3SPaolo Bonzini int end_level; 1480c50d8ae3SPaolo Bonzini 1481c50d8ae3SPaolo Bonzini /* output fields. */ 1482c50d8ae3SPaolo Bonzini gfn_t gfn; 1483c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1484c50d8ae3SPaolo Bonzini int level; 1485c50d8ae3SPaolo Bonzini 1486c50d8ae3SPaolo Bonzini /* private field. */ 1487c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1488c50d8ae3SPaolo Bonzini }; 1489c50d8ae3SPaolo Bonzini 1490c50d8ae3SPaolo Bonzini static void 1491c50d8ae3SPaolo Bonzini rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level) 1492c50d8ae3SPaolo Bonzini { 1493c50d8ae3SPaolo Bonzini iterator->level = level; 1494c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 149593e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 149693e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1497c50d8ae3SPaolo Bonzini } 1498c50d8ae3SPaolo Bonzini 1499c50d8ae3SPaolo Bonzini static void 1500c50d8ae3SPaolo Bonzini slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1501269e9552SHamza Mahfooz const struct kvm_memory_slot *slot, int start_level, 1502c50d8ae3SPaolo Bonzini int end_level, gfn_t start_gfn, gfn_t end_gfn) 1503c50d8ae3SPaolo Bonzini { 1504c50d8ae3SPaolo Bonzini iterator->slot = slot; 1505c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1506c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1507c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1508c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1509c50d8ae3SPaolo Bonzini 1510c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1511c50d8ae3SPaolo Bonzini } 1512c50d8ae3SPaolo Bonzini 1513c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1514c50d8ae3SPaolo Bonzini { 1515c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1516c50d8ae3SPaolo Bonzini } 1517c50d8ae3SPaolo Bonzini 1518c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1519c50d8ae3SPaolo Bonzini { 15206ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1521c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 15226ba1e04fSVipin Sharma 15236ba1e04fSVipin Sharma if (iterator->rmap->val) 1524c50d8ae3SPaolo Bonzini return; 1525c50d8ae3SPaolo Bonzini } 1526c50d8ae3SPaolo Bonzini 1527c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1528c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1529c50d8ae3SPaolo Bonzini return; 1530c50d8ae3SPaolo Bonzini } 1531c50d8ae3SPaolo Bonzini 1532c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1533c50d8ae3SPaolo Bonzini } 1534c50d8ae3SPaolo Bonzini 1535c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1536c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1537c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1538c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1539c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1540c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1541c50d8ae3SPaolo Bonzini 15423039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1543c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15443039bcc7SSean Christopherson int level, pte_t pte); 1545c1b91493SSean Christopherson 15463039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15473039bcc7SSean Christopherson struct kvm_gfn_range *range, 1548c1b91493SSean Christopherson rmap_handler_t handler) 1549c50d8ae3SPaolo Bonzini { 1550c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15513039bcc7SSean Christopherson bool ret = false; 1552c50d8ae3SPaolo Bonzini 15533039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15543039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15553039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15563039bcc7SSean Christopherson iterator.level, range->pte); 1557c50d8ae3SPaolo Bonzini 1558c50d8ae3SPaolo Bonzini return ret; 1559c50d8ae3SPaolo Bonzini } 1560c50d8ae3SPaolo Bonzini 15613039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1562c50d8ae3SPaolo Bonzini { 1563e2209710SBen Gardon bool flush = false; 1564c50d8ae3SPaolo Bonzini 1565e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1566f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1567063afacdSBen Gardon 15681f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1569c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1570063afacdSBen Gardon 15713039bcc7SSean Christopherson return flush; 1572c50d8ae3SPaolo Bonzini } 1573c50d8ae3SPaolo Bonzini 15743039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1575c50d8ae3SPaolo Bonzini { 1576e2209710SBen Gardon bool flush = false; 15771d8dd6b3SBen Gardon 1578e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1579aed02fe3SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); 15801d8dd6b3SBen Gardon 15811f98f2bdSDavid Matlack if (tdp_mmu_enabled) 15823039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 15831d8dd6b3SBen Gardon 15843039bcc7SSean Christopherson return flush; 1585c50d8ae3SPaolo Bonzini } 1586c50d8ae3SPaolo Bonzini 1587aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1588c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 15893039bcc7SSean Christopherson pte_t unused) 1590c50d8ae3SPaolo Bonzini { 1591c50d8ae3SPaolo Bonzini u64 *sptep; 15923f649ab7SKees Cook struct rmap_iterator iter; 1593c50d8ae3SPaolo Bonzini int young = 0; 1594c50d8ae3SPaolo Bonzini 1595c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1596c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1597c50d8ae3SPaolo Bonzini 1598c50d8ae3SPaolo Bonzini return young; 1599c50d8ae3SPaolo Bonzini } 1600c50d8ae3SPaolo Bonzini 1601aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1602c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 16033039bcc7SSean Christopherson int level, pte_t unused) 1604c50d8ae3SPaolo Bonzini { 1605c50d8ae3SPaolo Bonzini u64 *sptep; 1606c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1607c50d8ae3SPaolo Bonzini 1608c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1609c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 161098a26b69SVihas Mak return true; 161198a26b69SVihas Mak return false; 1612c50d8ae3SPaolo Bonzini } 1613c50d8ae3SPaolo Bonzini 1614c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1615c50d8ae3SPaolo Bonzini 16162ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 16172ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 16182ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 161972ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1620c50d8ae3SPaolo Bonzini { 1621c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 162268be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 162368be1306SDavid Matlack int rmap_count; 1624c50d8ae3SPaolo Bonzini 162557354682SSean Christopherson sp = sptep_to_sp(spte); 162679e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 162781cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 162881cb4657SDavid Matlack 162993e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 16302ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1631c50d8ae3SPaolo Bonzini 1632604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1633604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 163468be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16359202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 163668be1306SDavid Matlack kvm_flush_remote_tlbs_with_address( 16372ff9039aSDavid Matlack kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); 163868be1306SDavid Matlack } 1639c50d8ae3SPaolo Bonzini } 1640c50d8ae3SPaolo Bonzini 16412ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 164272ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16432ff9039aSDavid Matlack { 16442ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16452ff9039aSDavid Matlack 16466a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16472ff9039aSDavid Matlack } 16482ff9039aSDavid Matlack 16493039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1650c50d8ae3SPaolo Bonzini { 1651e2209710SBen Gardon bool young = false; 1652f8e14497SBen Gardon 1653e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1654aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16553039bcc7SSean Christopherson 16561f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16573039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1658f8e14497SBen Gardon 1659f8e14497SBen Gardon return young; 1660c50d8ae3SPaolo Bonzini } 1661c50d8ae3SPaolo Bonzini 16623039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1663c50d8ae3SPaolo Bonzini { 1664e2209710SBen Gardon bool young = false; 1665f8e14497SBen Gardon 1666e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1667aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 16683039bcc7SSean Christopherson 16691f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16703039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1671f8e14497SBen Gardon 1672f8e14497SBen Gardon return young; 1673c50d8ae3SPaolo Bonzini } 1674c50d8ae3SPaolo Bonzini 1675c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1676c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1677c50d8ae3SPaolo Bonzini { 1678c50d8ae3SPaolo Bonzini u64 *pos; 1679c50d8ae3SPaolo Bonzini u64 *end; 1680c50d8ae3SPaolo Bonzini 16813adbdf81SMiaohe Lin for (pos = spt, end = pos + SPTE_ENT_PER_PAGE; pos != end; pos++) 1682c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1683c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1684c50d8ae3SPaolo Bonzini pos, *pos); 1685c50d8ae3SPaolo Bonzini return 0; 1686c50d8ae3SPaolo Bonzini } 1687c50d8ae3SPaolo Bonzini return 1; 1688c50d8ae3SPaolo Bonzini } 1689c50d8ae3SPaolo Bonzini #endif 1690c50d8ae3SPaolo Bonzini 1691c50d8ae3SPaolo Bonzini /* 1692c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1693c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1694c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1695c50d8ae3SPaolo Bonzini * faster 1696c50d8ae3SPaolo Bonzini */ 1697d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1698c50d8ae3SPaolo Bonzini { 1699c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1700c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1701c50d8ae3SPaolo Bonzini } 1702c50d8ae3SPaolo Bonzini 170343a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 170443a063caSYosry Ahmed { 170543a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 170643a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 170743a063caSYosry Ahmed } 170843a063caSYosry Ahmed 170943a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 171043a063caSYosry Ahmed { 171143a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 171243a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 171343a063caSYosry Ahmed } 171443a063caSYosry Ahmed 171587654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1716c50d8ae3SPaolo Bonzini { 1717c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1718c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1719c50d8ae3SPaolo Bonzini list_del(&sp->link); 1720c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1721c50d8ae3SPaolo Bonzini if (!sp->role.direct) 17226a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1723c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1724c50d8ae3SPaolo Bonzini } 1725c50d8ae3SPaolo Bonzini 1726c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1727c50d8ae3SPaolo Bonzini { 1728c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1729c50d8ae3SPaolo Bonzini } 1730c50d8ae3SPaolo Bonzini 17312ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1732c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1733c50d8ae3SPaolo Bonzini { 1734c50d8ae3SPaolo Bonzini if (!parent_pte) 1735c50d8ae3SPaolo Bonzini return; 1736c50d8ae3SPaolo Bonzini 17372ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1738c50d8ae3SPaolo Bonzini } 1739c50d8ae3SPaolo Bonzini 1740c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1741c50d8ae3SPaolo Bonzini u64 *parent_pte) 1742c50d8ae3SPaolo Bonzini { 17433c2e1037SSean Christopherson pte_list_remove(parent_pte, &sp->parent_ptes); 1744c50d8ae3SPaolo Bonzini } 1745c50d8ae3SPaolo Bonzini 1746c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1747c50d8ae3SPaolo Bonzini u64 *parent_pte) 1748c50d8ae3SPaolo Bonzini { 1749c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1750c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1751c50d8ae3SPaolo Bonzini } 1752c50d8ae3SPaolo Bonzini 1753c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1754c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1755c50d8ae3SPaolo Bonzini { 1756c50d8ae3SPaolo Bonzini u64 *sptep; 1757c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1758c50d8ae3SPaolo Bonzini 1759c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1760c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1761c50d8ae3SPaolo Bonzini } 1762c50d8ae3SPaolo Bonzini } 1763c50d8ae3SPaolo Bonzini 1764c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1765c50d8ae3SPaolo Bonzini { 1766c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1767c50d8ae3SPaolo Bonzini 176857354682SSean Christopherson sp = sptep_to_sp(spte); 176979e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1770c50d8ae3SPaolo Bonzini return; 1771c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1772c50d8ae3SPaolo Bonzini return; 1773c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1774c50d8ae3SPaolo Bonzini } 1775c50d8ae3SPaolo Bonzini 1776c50d8ae3SPaolo Bonzini static int nonpaging_sync_page(struct kvm_vcpu *vcpu, 1777c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp) 1778c50d8ae3SPaolo Bonzini { 1779c3e5e415SLai Jiangshan return -1; 1780c50d8ae3SPaolo Bonzini } 1781c50d8ae3SPaolo Bonzini 1782c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1783c50d8ae3SPaolo Bonzini 1784c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1785c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1786c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1787c50d8ae3SPaolo Bonzini unsigned int idx; 1788c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1789c50d8ae3SPaolo Bonzini unsigned int nr; 1790c50d8ae3SPaolo Bonzini }; 1791c50d8ae3SPaolo Bonzini 1792c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1793c50d8ae3SPaolo Bonzini int idx) 1794c50d8ae3SPaolo Bonzini { 1795c50d8ae3SPaolo Bonzini int i; 1796c50d8ae3SPaolo Bonzini 1797c50d8ae3SPaolo Bonzini if (sp->unsync) 1798c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1799c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1800c50d8ae3SPaolo Bonzini return 0; 1801c50d8ae3SPaolo Bonzini 1802c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1803c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1804c50d8ae3SPaolo Bonzini pvec->nr++; 1805c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1806c50d8ae3SPaolo Bonzini } 1807c50d8ae3SPaolo Bonzini 1808c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1809c50d8ae3SPaolo Bonzini { 1810c50d8ae3SPaolo Bonzini --sp->unsync_children; 1811c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1812c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1813c50d8ae3SPaolo Bonzini } 1814c50d8ae3SPaolo Bonzini 1815c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1816c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1817c50d8ae3SPaolo Bonzini { 1818c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1819c50d8ae3SPaolo Bonzini 1820c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1821c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1822c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1823c50d8ae3SPaolo Bonzini 1824c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1825c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1826c50d8ae3SPaolo Bonzini continue; 1827c50d8ae3SPaolo Bonzini } 1828c50d8ae3SPaolo Bonzini 18295e3edd7eSSean Christopherson child = spte_to_child_sp(ent); 1830c50d8ae3SPaolo Bonzini 1831c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1832c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1833c50d8ae3SPaolo Bonzini return -ENOSPC; 1834c50d8ae3SPaolo Bonzini 1835c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1836c50d8ae3SPaolo Bonzini if (!ret) { 1837c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1838c50d8ae3SPaolo Bonzini continue; 1839c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1840c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1841c50d8ae3SPaolo Bonzini } else 1842c50d8ae3SPaolo Bonzini return ret; 1843c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1844c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1845c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1846c50d8ae3SPaolo Bonzini return -ENOSPC; 1847c50d8ae3SPaolo Bonzini } else 1848c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1849c50d8ae3SPaolo Bonzini } 1850c50d8ae3SPaolo Bonzini 1851c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1852c50d8ae3SPaolo Bonzini } 1853c50d8ae3SPaolo Bonzini 1854c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1855c50d8ae3SPaolo Bonzini 1856c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1857c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1858c50d8ae3SPaolo Bonzini { 1859c50d8ae3SPaolo Bonzini pvec->nr = 0; 1860c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1861c50d8ae3SPaolo Bonzini return 0; 1862c50d8ae3SPaolo Bonzini 1863c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1864c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1865c50d8ae3SPaolo Bonzini } 1866c50d8ae3SPaolo Bonzini 1867c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1868c50d8ae3SPaolo Bonzini { 1869c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1870c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1871c50d8ae3SPaolo Bonzini sp->unsync = 0; 1872c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1873c50d8ae3SPaolo Bonzini } 1874c50d8ae3SPaolo Bonzini 1875c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1876c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1877c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1878c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1879c50d8ae3SPaolo Bonzini 1880767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1881767d8d8dSLai Jiangshan { 1882767d8d8dSLai Jiangshan if (sp->role.direct) 1883767d8d8dSLai Jiangshan return false; 1884767d8d8dSLai Jiangshan 188584e5ffd0SLai Jiangshan if (sp->role.passthrough) 188684e5ffd0SLai Jiangshan return false; 188784e5ffd0SLai Jiangshan 1888767d8d8dSLai Jiangshan return true; 1889767d8d8dSLai Jiangshan } 1890767d8d8dSLai Jiangshan 1891ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1892ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1893c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1894c50d8ae3SPaolo Bonzini } else 1895c50d8ae3SPaolo Bonzini 1896767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1897ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1898ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1899767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1900c50d8ae3SPaolo Bonzini 19018d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1902c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1903c50d8ae3SPaolo Bonzini { 1904c3e5e415SLai Jiangshan int ret = vcpu->arch.mmu->sync_page(vcpu, sp); 1905c3e5e415SLai Jiangshan 19068d5678a7SHou Wenlong if (ret < 0) 1907c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 19088d5678a7SHou Wenlong return ret; 1909c50d8ae3SPaolo Bonzini } 1910c50d8ae3SPaolo Bonzini 1911c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1912c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1913c50d8ae3SPaolo Bonzini bool remote_flush) 1914c50d8ae3SPaolo Bonzini { 1915c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1916c50d8ae3SPaolo Bonzini return false; 1917c50d8ae3SPaolo Bonzini 1918c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 1919c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 1920c50d8ae3SPaolo Bonzini else 1921c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 1922c50d8ae3SPaolo Bonzini return true; 1923c50d8ae3SPaolo Bonzini } 1924c50d8ae3SPaolo Bonzini 1925c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 1926c50d8ae3SPaolo Bonzini { 1927a955cad8SSean Christopherson if (sp->role.invalid) 1928a955cad8SSean Christopherson return true; 1929a955cad8SSean Christopherson 1930fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 1931a955cad8SSean Christopherson return !sp->tdp_mmu_page && 1932c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 1933c50d8ae3SPaolo Bonzini } 1934c50d8ae3SPaolo Bonzini 1935c50d8ae3SPaolo Bonzini struct mmu_page_path { 1936c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 1937c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 1938c50d8ae3SPaolo Bonzini }; 1939c50d8ae3SPaolo Bonzini 1940c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 1941c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 1942c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 1943c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 1944c50d8ae3SPaolo Bonzini 1945c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 1946c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 1947c50d8ae3SPaolo Bonzini int i) 1948c50d8ae3SPaolo Bonzini { 1949c50d8ae3SPaolo Bonzini int n; 1950c50d8ae3SPaolo Bonzini 1951c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 1952c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 1953c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 1954c50d8ae3SPaolo Bonzini int level = sp->role.level; 1955c50d8ae3SPaolo Bonzini 1956c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 19573bae0459SSean Christopherson if (level == PG_LEVEL_4K) 1958c50d8ae3SPaolo Bonzini break; 1959c50d8ae3SPaolo Bonzini 1960c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1961c50d8ae3SPaolo Bonzini } 1962c50d8ae3SPaolo Bonzini 1963c50d8ae3SPaolo Bonzini return n; 1964c50d8ae3SPaolo Bonzini } 1965c50d8ae3SPaolo Bonzini 1966c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 1967c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 1968c50d8ae3SPaolo Bonzini { 1969c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1970c50d8ae3SPaolo Bonzini int level; 1971c50d8ae3SPaolo Bonzini 1972c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 1973c50d8ae3SPaolo Bonzini return 0; 1974c50d8ae3SPaolo Bonzini 1975c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 1976c50d8ae3SPaolo Bonzini 1977c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 1978c50d8ae3SPaolo Bonzini level = sp->role.level; 19793bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 1980c50d8ae3SPaolo Bonzini 1981c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 1982c50d8ae3SPaolo Bonzini 1983c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 1984c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 1985c50d8ae3SPaolo Bonzini */ 1986c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 1987c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 1988c50d8ae3SPaolo Bonzini } 1989c50d8ae3SPaolo Bonzini 1990c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 1991c50d8ae3SPaolo Bonzini { 1992c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1993c50d8ae3SPaolo Bonzini unsigned int level = 0; 1994c50d8ae3SPaolo Bonzini 1995c50d8ae3SPaolo Bonzini do { 1996c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 1997c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 1998c50d8ae3SPaolo Bonzini if (!sp) 1999c50d8ae3SPaolo Bonzini return; 2000c50d8ae3SPaolo Bonzini 2001c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 2002c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 2003c50d8ae3SPaolo Bonzini level++; 2004c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 2005c50d8ae3SPaolo Bonzini } 2006c50d8ae3SPaolo Bonzini 200765855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 200865855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 2009c50d8ae3SPaolo Bonzini { 2010c50d8ae3SPaolo Bonzini int i; 2011c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2012c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2013c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2014c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2015c50d8ae3SPaolo Bonzini bool flush = false; 2016c50d8ae3SPaolo Bonzini 2017c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2018c50d8ae3SPaolo Bonzini bool protected = false; 2019c50d8ae3SPaolo Bonzini 2020c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 2021cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 2022c50d8ae3SPaolo Bonzini 2023c50d8ae3SPaolo Bonzini if (protected) { 20245591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 2025c50d8ae3SPaolo Bonzini flush = false; 2026c50d8ae3SPaolo Bonzini } 2027c50d8ae3SPaolo Bonzini 2028c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2029479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 20308d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 2031c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2032c50d8ae3SPaolo Bonzini } 2033531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2034c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 203565855ed8SLai Jiangshan if (!can_yield) { 203665855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 203765855ed8SLai Jiangshan return -EINTR; 203865855ed8SLai Jiangshan } 203965855ed8SLai Jiangshan 2040531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2041c50d8ae3SPaolo Bonzini flush = false; 2042c50d8ae3SPaolo Bonzini } 2043c50d8ae3SPaolo Bonzini } 2044c50d8ae3SPaolo Bonzini 2045c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 204665855ed8SLai Jiangshan return 0; 2047c50d8ae3SPaolo Bonzini } 2048c50d8ae3SPaolo Bonzini 2049c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2050c50d8ae3SPaolo Bonzini { 2051c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2052c50d8ae3SPaolo Bonzini } 2053c50d8ae3SPaolo Bonzini 2054c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2055c50d8ae3SPaolo Bonzini { 205657354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2057c50d8ae3SPaolo Bonzini } 2058c50d8ae3SPaolo Bonzini 2059cbd858b1SDavid Matlack /* 2060cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2061cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2062cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2063cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2064cbd858b1SDavid Matlack */ 20653cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 20663cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 206794c81364SDavid Matlack gfn_t gfn, 206894c81364SDavid Matlack struct hlist_head *sp_list, 20692e65e842SDavid Matlack union kvm_mmu_page_role role) 2070c50d8ae3SPaolo Bonzini { 2071c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 20728d5678a7SHou Wenlong int ret; 2073c50d8ae3SPaolo Bonzini int collisions = 0; 2074c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2075c50d8ae3SPaolo Bonzini 20763cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2077c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2078c50d8ae3SPaolo Bonzini collisions++; 2079c50d8ae3SPaolo Bonzini continue; 2080c50d8ae3SPaolo Bonzini } 2081c50d8ae3SPaolo Bonzini 2082ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2083ddc16abbSSean Christopherson /* 2084ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2085ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2086ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2087ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2088ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2089ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2090ddc16abbSSean Christopherson * upper-level page will be write-protected. 2091ddc16abbSSean Christopherson */ 20922e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 20933cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2094ddc16abbSSean Christopherson &invalid_list); 2095c50d8ae3SPaolo Bonzini continue; 2096ddc16abbSSean Christopherson } 2097c50d8ae3SPaolo Bonzini 2098bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2099bb924ca6SDavid Matlack if (sp->role.direct) 210094c81364SDavid Matlack goto out; 2101fb58a9c3SSean Christopherson 2102c50d8ae3SPaolo Bonzini if (sp->unsync) { 2103cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2104cbd858b1SDavid Matlack break; 2105cbd858b1SDavid Matlack 210607dc4f35SSean Christopherson /* 2107479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 210807dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 210907dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 211007dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 211107dc4f35SSean Christopherson * overhead of write protection is not incurred until the 211207dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 211307dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 211407dc4f35SSean Christopherson * 211507dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 211607dc4f35SSean Christopherson * in order to rebuild it. 2117c50d8ae3SPaolo Bonzini */ 21188d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 21198d5678a7SHou Wenlong if (ret < 0) 2120c50d8ae3SPaolo Bonzini break; 2121c50d8ae3SPaolo Bonzini 2122c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 21238d5678a7SHou Wenlong if (ret > 0) 21243cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2125c50d8ae3SPaolo Bonzini } 2126c50d8ae3SPaolo Bonzini 2127c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2128fb58a9c3SSean Christopherson 2129c50d8ae3SPaolo Bonzini goto out; 2130c50d8ae3SPaolo Bonzini } 2131c50d8ae3SPaolo Bonzini 213294c81364SDavid Matlack sp = NULL; 21333cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2134c50d8ae3SPaolo Bonzini 213594c81364SDavid Matlack out: 21363cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 213794c81364SDavid Matlack 21383cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 21393cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 214094c81364SDavid Matlack return sp; 214194c81364SDavid Matlack } 214294c81364SDavid Matlack 21432f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 21442f8b1b53SDavid Matlack struct shadow_page_caches { 21452f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 21462f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 21476a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 21482f8b1b53SDavid Matlack }; 21492f8b1b53SDavid Matlack 2150336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 21512f8b1b53SDavid Matlack struct shadow_page_caches *caches, 215294c81364SDavid Matlack gfn_t gfn, 215394c81364SDavid Matlack struct hlist_head *sp_list, 215494c81364SDavid Matlack union kvm_mmu_page_role role) 215594c81364SDavid Matlack { 2156c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2157c306aec8SDavid Matlack 21582f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 21592f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2160c306aec8SDavid Matlack if (!role.direct) 21616a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2162c306aec8SDavid Matlack 2163c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2164c306aec8SDavid Matlack 216555c510e2SSean Christopherson INIT_LIST_HEAD(&sp->possible_nx_huge_page_link); 2166428e9216SSean Christopherson 2167c306aec8SDavid Matlack /* 2168c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2169c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2170c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2171c306aec8SDavid Matlack */ 2172336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2173336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 217443a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2175c50d8ae3SPaolo Bonzini 2176c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2177c50d8ae3SPaolo Bonzini sp->role = role; 2178ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2179be911771SDavid Matlack if (sp_has_gptes(sp)) 2180336081fbSDavid Matlack account_shadowed(kvm, sp); 2181ddc16abbSSean Christopherson 218294c81364SDavid Matlack return sp; 218394c81364SDavid Matlack } 218494c81364SDavid Matlack 2185cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 21863cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 21873cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 21882f8b1b53SDavid Matlack struct shadow_page_caches *caches, 218987654643SDavid Matlack gfn_t gfn, 219094c81364SDavid Matlack union kvm_mmu_page_role role) 219194c81364SDavid Matlack { 219294c81364SDavid Matlack struct hlist_head *sp_list; 219394c81364SDavid Matlack struct kvm_mmu_page *sp; 219494c81364SDavid Matlack bool created = false; 219594c81364SDavid Matlack 21963cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 219794c81364SDavid Matlack 21983cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 219994c81364SDavid Matlack if (!sp) { 220094c81364SDavid Matlack created = true; 22013cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 220294c81364SDavid Matlack } 220394c81364SDavid Matlack 220494c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2205c50d8ae3SPaolo Bonzini return sp; 2206c50d8ae3SPaolo Bonzini } 2207c50d8ae3SPaolo Bonzini 22082f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 22092f8b1b53SDavid Matlack gfn_t gfn, 22102f8b1b53SDavid Matlack union kvm_mmu_page_role role) 22112f8b1b53SDavid Matlack { 22122f8b1b53SDavid Matlack struct shadow_page_caches caches = { 22132f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 22142f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 22156a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 22162f8b1b53SDavid Matlack }; 22172f8b1b53SDavid Matlack 22183cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 22192f8b1b53SDavid Matlack } 22202f8b1b53SDavid Matlack 222139944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 222239944ab9SSean Christopherson unsigned int access) 22232e65e842SDavid Matlack { 22242e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 22252e65e842SDavid Matlack union kvm_mmu_page_role role; 22262e65e842SDavid Matlack 22272e65e842SDavid Matlack role = parent_sp->role; 22282e65e842SDavid Matlack role.level--; 22292e65e842SDavid Matlack role.access = access; 22302e65e842SDavid Matlack role.direct = direct; 22312e65e842SDavid Matlack role.passthrough = 0; 22322e65e842SDavid Matlack 22332e65e842SDavid Matlack /* 22342e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 22352e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 22362e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 22372e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 22382e65e842SDavid Matlack * requires extra bookkeeping in the role. 22392e65e842SDavid Matlack * 22402e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 22412e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 22422e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 22432e65e842SDavid Matlack * the address space each maps. 22442e65e842SDavid Matlack * 22452e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 22462e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 22472e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 22482e65e842SDavid Matlack * 224939944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 225039944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 225139944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 225239944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 225339944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 225439944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 225539944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 225639944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 225739944ab9SSean Christopherson * _least_ significant bit of the PDE index. 22582e65e842SDavid Matlack */ 22592e65e842SDavid Matlack if (role.has_4_byte_gpte) { 22602e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 226179e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 22622e65e842SDavid Matlack } 22632e65e842SDavid Matlack 22642e65e842SDavid Matlack return role; 22652e65e842SDavid Matlack } 22662e65e842SDavid Matlack 22672e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 22682e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 22692e65e842SDavid Matlack bool direct, unsigned int access) 22702e65e842SDavid Matlack { 22712e65e842SDavid Matlack union kvm_mmu_page_role role; 22722e65e842SDavid Matlack 22730cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 22740cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 22750cd8dc73SPaolo Bonzini 22762e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 227787654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 22782e65e842SDavid Matlack } 22792e65e842SDavid Matlack 2280c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2281c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2282c50d8ae3SPaolo Bonzini u64 addr) 2283c50d8ae3SPaolo Bonzini { 2284c50d8ae3SPaolo Bonzini iterator->addr = addr; 2285c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2286a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2287c50d8ae3SPaolo Bonzini 228812ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 22894d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2290347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 229112ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2292c50d8ae3SPaolo Bonzini 2293c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2294c50d8ae3SPaolo Bonzini /* 2295c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2296c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2297c50d8ae3SPaolo Bonzini */ 2298b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2299c50d8ae3SPaolo Bonzini 2300c50d8ae3SPaolo Bonzini iterator->shadow_addr 2301c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 23022ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2303c50d8ae3SPaolo Bonzini --iterator->level; 2304c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2305c50d8ae3SPaolo Bonzini iterator->level = 0; 2306c50d8ae3SPaolo Bonzini } 2307c50d8ae3SPaolo Bonzini } 2308c50d8ae3SPaolo Bonzini 2309c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2310c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2311c50d8ae3SPaolo Bonzini { 2312b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2313c50d8ae3SPaolo Bonzini addr); 2314c50d8ae3SPaolo Bonzini } 2315c50d8ae3SPaolo Bonzini 2316c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2317c50d8ae3SPaolo Bonzini { 23183bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2319c50d8ae3SPaolo Bonzini return false; 2320c50d8ae3SPaolo Bonzini 23212ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2322c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2323c50d8ae3SPaolo Bonzini return true; 2324c50d8ae3SPaolo Bonzini } 2325c50d8ae3SPaolo Bonzini 2326c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2327c50d8ae3SPaolo Bonzini u64 spte) 2328c50d8ae3SPaolo Bonzini { 23293e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2330c50d8ae3SPaolo Bonzini iterator->level = 0; 2331c50d8ae3SPaolo Bonzini return; 2332c50d8ae3SPaolo Bonzini } 2333c50d8ae3SPaolo Bonzini 23342ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2335c50d8ae3SPaolo Bonzini --iterator->level; 2336c50d8ae3SPaolo Bonzini } 2337c50d8ae3SPaolo Bonzini 2338c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2339c50d8ae3SPaolo Bonzini { 2340c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2341c50d8ae3SPaolo Bonzini } 2342c50d8ae3SPaolo Bonzini 23430cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 23440cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 234503787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2346c50d8ae3SPaolo Bonzini { 2347c50d8ae3SPaolo Bonzini u64 spte; 2348c50d8ae3SPaolo Bonzini 2349c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2350c50d8ae3SPaolo Bonzini 23510cd8dc73SPaolo Bonzini /* 23520cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 235303787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 235403787394SPaolo Bonzini * installing sp. 23550cd8dc73SPaolo Bonzini */ 23560cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 235703787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 23580cd8dc73SPaolo Bonzini 2359cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2360c50d8ae3SPaolo Bonzini 2361c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2362c50d8ae3SPaolo Bonzini 23632ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2364c50d8ae3SPaolo Bonzini 2365c4a48868SLai Jiangshan /* 2366c4a48868SLai Jiangshan * The non-direct sub-pagetable must be updated before linking. For 2367c4a48868SLai Jiangshan * L1 sp, the pagetable is updated via kvm_sync_page() in 2368c4a48868SLai Jiangshan * kvm_mmu_find_shadow_page() without write-protecting the gfn, 2369c4a48868SLai Jiangshan * so sp->unsync can be true or false. For higher level non-direct 2370c4a48868SLai Jiangshan * sp, the pagetable is updated/synced via mmu_sync_children() in 2371c4a48868SLai Jiangshan * FNAME(fetch)(), so sp->unsync_children can only be false. 2372c4a48868SLai Jiangshan * WARN_ON_ONCE() if anything happens unexpectedly. 2373c4a48868SLai Jiangshan */ 2374c4a48868SLai Jiangshan if (WARN_ON_ONCE(sp->unsync_children) || sp->unsync) 2375c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2376c50d8ae3SPaolo Bonzini } 2377c50d8ae3SPaolo Bonzini 23782ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 23792ff9039aSDavid Matlack struct kvm_mmu_page *sp) 23802ff9039aSDavid Matlack { 238103787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 23822ff9039aSDavid Matlack } 23832ff9039aSDavid Matlack 2384c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2385c50d8ae3SPaolo Bonzini unsigned direct_access) 2386c50d8ae3SPaolo Bonzini { 2387c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2388c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2389c50d8ae3SPaolo Bonzini 2390c50d8ae3SPaolo Bonzini /* 2391c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2392c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2393c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2394c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2395c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2396c50d8ae3SPaolo Bonzini */ 23975e3edd7eSSean Christopherson child = spte_to_child_sp(*sptep); 2398c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2399c50d8ae3SPaolo Bonzini return; 2400c50d8ae3SPaolo Bonzini 2401c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2402c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, child->gfn, 1); 2403c50d8ae3SPaolo Bonzini } 2404c50d8ae3SPaolo Bonzini } 2405c50d8ae3SPaolo Bonzini 24062de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 24072de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 24082de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2409c50d8ae3SPaolo Bonzini { 2410c50d8ae3SPaolo Bonzini u64 pte; 2411c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2412c50d8ae3SPaolo Bonzini 2413c50d8ae3SPaolo Bonzini pte = *spte; 2414c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2415c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2416c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2417c50d8ae3SPaolo Bonzini } else { 24185e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2419c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 24202de4085cSBen Gardon 24212de4085cSBen Gardon /* 24222de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 24232de4085cSBen Gardon * unlikely to be used again in the near future. This 24242de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 24252de4085cSBen Gardon */ 24262de4085cSBen Gardon if (tdp_enabled && invalid_list && 24272de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 24282de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 24292de4085cSBen Gardon invalid_list); 2430c50d8ae3SPaolo Bonzini } 2431ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2432c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2433ace569e0SSean Christopherson } 24342de4085cSBen Gardon return 0; 2435c50d8ae3SPaolo Bonzini } 2436c50d8ae3SPaolo Bonzini 24372de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 24382de4085cSBen Gardon struct kvm_mmu_page *sp, 24392de4085cSBen Gardon struct list_head *invalid_list) 2440c50d8ae3SPaolo Bonzini { 24412de4085cSBen Gardon int zapped = 0; 2442c50d8ae3SPaolo Bonzini unsigned i; 2443c50d8ae3SPaolo Bonzini 24442ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 24452de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 24462de4085cSBen Gardon 24472de4085cSBen Gardon return zapped; 2448c50d8ae3SPaolo Bonzini } 2449c50d8ae3SPaolo Bonzini 245061827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2451c50d8ae3SPaolo Bonzini { 2452c50d8ae3SPaolo Bonzini u64 *sptep; 2453c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2454c50d8ae3SPaolo Bonzini 2455c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2456c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2457c50d8ae3SPaolo Bonzini } 2458c50d8ae3SPaolo Bonzini 2459c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2460c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2461c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2462c50d8ae3SPaolo Bonzini { 2463c50d8ae3SPaolo Bonzini int i, zapped = 0; 2464c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2465c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2466c50d8ae3SPaolo Bonzini 24673bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2468c50d8ae3SPaolo Bonzini return 0; 2469c50d8ae3SPaolo Bonzini 2470c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2471c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2472c50d8ae3SPaolo Bonzini 2473c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2474c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2475c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2476c50d8ae3SPaolo Bonzini zapped++; 2477c50d8ae3SPaolo Bonzini } 2478c50d8ae3SPaolo Bonzini } 2479c50d8ae3SPaolo Bonzini 2480c50d8ae3SPaolo Bonzini return zapped; 2481c50d8ae3SPaolo Bonzini } 2482c50d8ae3SPaolo Bonzini 2483c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2484c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2485c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2486c50d8ae3SPaolo Bonzini int *nr_zapped) 2487c50d8ae3SPaolo Bonzini { 2488527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2489c50d8ae3SPaolo Bonzini 2490c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2491c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2492c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 24932de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 249461827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2495c50d8ae3SPaolo Bonzini 2496c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2497c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2498c50d8ae3SPaolo Bonzini 2499767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2500c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2501c50d8ae3SPaolo Bonzini 2502c50d8ae3SPaolo Bonzini if (sp->unsync) 2503c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2504c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2505c50d8ae3SPaolo Bonzini /* Count self */ 2506c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2507f95eec9bSSean Christopherson 2508f95eec9bSSean Christopherson /* 2509f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2510f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2511f95eec9bSSean Christopherson * !sp->root_count. 2512f95eec9bSSean Christopherson */ 2513f95eec9bSSean Christopherson if (sp->role.invalid) 2514f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2515f95eec9bSSean Christopherson else 2516c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 251743a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2518c50d8ae3SPaolo Bonzini } else { 2519f95eec9bSSean Christopherson /* 2520f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2521f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2522f95eec9bSSean Christopherson */ 2523f95eec9bSSean Christopherson list_del(&sp->link); 2524c50d8ae3SPaolo Bonzini 2525c50d8ae3SPaolo Bonzini /* 2526c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2527c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2528c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2529c50d8ae3SPaolo Bonzini */ 2530527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2531c50d8ae3SPaolo Bonzini } 2532c50d8ae3SPaolo Bonzini 253355c510e2SSean Christopherson if (sp->nx_huge_page_disallowed) 253455c510e2SSean Christopherson unaccount_nx_huge_page(kvm, sp); 2535c50d8ae3SPaolo Bonzini 2536c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2537527d5cd7SSean Christopherson 2538527d5cd7SSean Christopherson /* 2539527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2540527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2541527d5cd7SSean Christopherson */ 2542527d5cd7SSean Christopherson if (zapped_root) 2543527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2544c50d8ae3SPaolo Bonzini return list_unstable; 2545c50d8ae3SPaolo Bonzini } 2546c50d8ae3SPaolo Bonzini 2547c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2548c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2549c50d8ae3SPaolo Bonzini { 2550c50d8ae3SPaolo Bonzini int nr_zapped; 2551c50d8ae3SPaolo Bonzini 2552c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2553c50d8ae3SPaolo Bonzini return nr_zapped; 2554c50d8ae3SPaolo Bonzini } 2555c50d8ae3SPaolo Bonzini 2556c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2557c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2558c50d8ae3SPaolo Bonzini { 2559c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2560c50d8ae3SPaolo Bonzini 2561c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2562c50d8ae3SPaolo Bonzini return; 2563c50d8ae3SPaolo Bonzini 2564c50d8ae3SPaolo Bonzini /* 2565c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2566c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2567c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2568c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2569c50d8ae3SPaolo Bonzini * 2570c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2571c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2572c50d8ae3SPaolo Bonzini */ 2573c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2574c50d8ae3SPaolo Bonzini 2575c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2576c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 257787654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2578c50d8ae3SPaolo Bonzini } 2579c50d8ae3SPaolo Bonzini } 2580c50d8ae3SPaolo Bonzini 25816b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 25826b82ef2cSSean Christopherson unsigned long nr_to_zap) 2583c50d8ae3SPaolo Bonzini { 25846b82ef2cSSean Christopherson unsigned long total_zapped = 0; 25856b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2586ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 25876b82ef2cSSean Christopherson bool unstable; 25886b82ef2cSSean Christopherson int nr_zapped; 2589c50d8ae3SPaolo Bonzini 2590c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2591ba7888ddSSean Christopherson return 0; 2592c50d8ae3SPaolo Bonzini 25936b82ef2cSSean Christopherson restart: 25948fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 25956b82ef2cSSean Christopherson /* 25966b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 25976b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 25986b82ef2cSSean Christopherson */ 25996b82ef2cSSean Christopherson if (sp->root_count) 26006b82ef2cSSean Christopherson continue; 26016b82ef2cSSean Christopherson 26026b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 26036b82ef2cSSean Christopherson &nr_zapped); 26046b82ef2cSSean Christopherson total_zapped += nr_zapped; 26056b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2606ba7888ddSSean Christopherson break; 2607ba7888ddSSean Christopherson 26086b82ef2cSSean Christopherson if (unstable) 26096b82ef2cSSean Christopherson goto restart; 2610ba7888ddSSean Christopherson } 26116b82ef2cSSean Christopherson 26126b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 26136b82ef2cSSean Christopherson 26146b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 26156b82ef2cSSean Christopherson return total_zapped; 26166b82ef2cSSean Christopherson } 26176b82ef2cSSean Christopherson 2618afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2619afe8d7e6SSean Christopherson { 2620afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2621afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2622afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2623afe8d7e6SSean Christopherson 2624afe8d7e6SSean Christopherson return 0; 2625c50d8ae3SPaolo Bonzini } 2626c50d8ae3SPaolo Bonzini 2627ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2628ba7888ddSSean Christopherson { 26296b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2630ba7888ddSSean Christopherson 26316b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2632ba7888ddSSean Christopherson return 0; 2633ba7888ddSSean Christopherson 26346b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2635ba7888ddSSean Christopherson 26366e6ec584SSean Christopherson /* 26376e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 26386e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 26396e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 26406e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2641c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 26426e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 26436e6ec584SSean Christopherson * page fault paths. 26446e6ec584SSean Christopherson */ 2645ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2646ba7888ddSSean Christopherson return -ENOSPC; 2647ba7888ddSSean Christopherson return 0; 2648ba7888ddSSean Christopherson } 2649ba7888ddSSean Christopherson 2650c50d8ae3SPaolo Bonzini /* 2651c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2652c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2653c50d8ae3SPaolo Bonzini */ 2654c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2655c50d8ae3SPaolo Bonzini { 2656531810caSBen Gardon write_lock(&kvm->mmu_lock); 2657c50d8ae3SPaolo Bonzini 2658c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 26596b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 26606b82ef2cSSean Christopherson goal_nr_mmu_pages); 2661c50d8ae3SPaolo Bonzini 2662c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2663c50d8ae3SPaolo Bonzini } 2664c50d8ae3SPaolo Bonzini 2665c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2666c50d8ae3SPaolo Bonzini 2667531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2668c50d8ae3SPaolo Bonzini } 2669c50d8ae3SPaolo Bonzini 2670c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2671c50d8ae3SPaolo Bonzini { 2672c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2673c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2674c50d8ae3SPaolo Bonzini int r; 2675c50d8ae3SPaolo Bonzini 2676c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2677c50d8ae3SPaolo Bonzini r = 0; 2678531810caSBen Gardon write_lock(&kvm->mmu_lock); 2679767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2680c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2681c50d8ae3SPaolo Bonzini sp->role.word); 2682c50d8ae3SPaolo Bonzini r = 1; 2683c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2684c50d8ae3SPaolo Bonzini } 2685c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2686531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2687c50d8ae3SPaolo Bonzini 2688c50d8ae3SPaolo Bonzini return r; 2689c50d8ae3SPaolo Bonzini } 269096ad91aeSSean Christopherson 269196ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 269296ad91aeSSean Christopherson { 269396ad91aeSSean Christopherson gpa_t gpa; 269496ad91aeSSean Christopherson int r; 269596ad91aeSSean Christopherson 2696347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 269796ad91aeSSean Christopherson return 0; 269896ad91aeSSean Christopherson 269996ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 270096ad91aeSSean Christopherson 270196ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 270296ad91aeSSean Christopherson 270396ad91aeSSean Christopherson return r; 270496ad91aeSSean Christopherson } 2705c50d8ae3SPaolo Bonzini 27064d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2707c50d8ae3SPaolo Bonzini { 2708c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 27094d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2710c50d8ae3SPaolo Bonzini sp->unsync = 1; 2711c50d8ae3SPaolo Bonzini 2712c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2713c50d8ae3SPaolo Bonzini } 2714c50d8ae3SPaolo Bonzini 27150337f585SSean Christopherson /* 27160337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 27170337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 27180337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 27190337f585SSean Christopherson * be write-protected. 27200337f585SSean Christopherson */ 27218283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 27222839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2723c50d8ae3SPaolo Bonzini { 2724c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2725ce25681dSSean Christopherson bool locked = false; 2726c50d8ae3SPaolo Bonzini 27270337f585SSean Christopherson /* 27280337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 27290337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 27300337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 27310337f585SSean Christopherson */ 27324d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 27330337f585SSean Christopherson return -EPERM; 2734c50d8ae3SPaolo Bonzini 27350337f585SSean Christopherson /* 27360337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 27370337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 27380337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 27390337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 27400337f585SSean Christopherson */ 2741767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2742c50d8ae3SPaolo Bonzini if (!can_unsync) 27430337f585SSean Christopherson return -EPERM; 2744c50d8ae3SPaolo Bonzini 2745c50d8ae3SPaolo Bonzini if (sp->unsync) 2746c50d8ae3SPaolo Bonzini continue; 2747c50d8ae3SPaolo Bonzini 27482839180cSPaolo Bonzini if (prefetch) 2749f1c4a88cSLai Jiangshan return -EEXIST; 2750f1c4a88cSLai Jiangshan 2751ce25681dSSean Christopherson /* 2752ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2753ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2754ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2755ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2756ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2757ce25681dSSean Christopherson */ 2758ce25681dSSean Christopherson if (!locked) { 2759ce25681dSSean Christopherson locked = true; 27604d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2761ce25681dSSean Christopherson 2762ce25681dSSean Christopherson /* 2763ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2764ce25681dSSean Christopherson * may have since marked the page unsync. A false 2765ce25681dSSean Christopherson * positive on the unprotected check above is not 2766ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2767ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2768ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2769ce25681dSSean Christopherson */ 2770ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2771ce25681dSSean Christopherson continue; 2772ce25681dSSean Christopherson } 2773ce25681dSSean Christopherson 27743bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 27754d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2776c50d8ae3SPaolo Bonzini } 2777ce25681dSSean Christopherson if (locked) 27784d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2779c50d8ae3SPaolo Bonzini 2780c50d8ae3SPaolo Bonzini /* 2781c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2782c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2783c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2784c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2785c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2786c50d8ae3SPaolo Bonzini * following could happen: 2787c50d8ae3SPaolo Bonzini * 2788c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2789c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2790c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2791c50d8ae3SPaolo Bonzini * to be writable 2792c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2793c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2794c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2795c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2796c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2797c50d8ae3SPaolo Bonzini * fault. 2798c50d8ae3SPaolo Bonzini * 2799c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2800c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2801c50d8ae3SPaolo Bonzini * 28020337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 28030337f585SSean Christopherson * false and skips the page. 2804c50d8ae3SPaolo Bonzini * 2805c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2806c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2807c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2808c50d8ae3SPaolo Bonzini * gets used. 2809c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2810c50d8ae3SPaolo Bonzini * as unsync 2811c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2812c50d8ae3SPaolo Bonzini * 2813c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2814264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2815264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2816c50d8ae3SPaolo Bonzini */ 2817c50d8ae3SPaolo Bonzini smp_wmb(); 2818c50d8ae3SPaolo Bonzini 28190337f585SSean Christopherson return 0; 2820c50d8ae3SPaolo Bonzini } 2821c50d8ae3SPaolo Bonzini 28228a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 28238a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2824a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2825799a4190SBen Gardon { 2826d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2827eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2828c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2829c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2830c50d8ae3SPaolo Bonzini bool flush = false; 2831ad67e480SPaolo Bonzini bool wrprot; 2832d786c778SPaolo Bonzini u64 spte; 2833c50d8ae3SPaolo Bonzini 2834a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2835a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 28362839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2837a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2838c50d8ae3SPaolo Bonzini 2839c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2840c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2841c50d8ae3SPaolo Bonzini 2842a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 28431075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2844a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2845a54aa15cSSean Christopherson return RET_PF_EMULATE; 2846a54aa15cSSean Christopherson } 2847a54aa15cSSean Christopherson 2848c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2849c50d8ae3SPaolo Bonzini /* 2850c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2851c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2852c50d8ae3SPaolo Bonzini */ 28533bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2854c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2855c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2856c50d8ae3SPaolo Bonzini 28575e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2858c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2859c50d8ae3SPaolo Bonzini flush = true; 2860c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2861c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2862c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2863c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2864c50d8ae3SPaolo Bonzini flush = true; 2865c50d8ae3SPaolo Bonzini } else 2866c50d8ae3SPaolo Bonzini was_rmapped = 1; 2867c50d8ae3SPaolo Bonzini } 2868c50d8ae3SPaolo Bonzini 28692839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 28707158bee4SPaolo Bonzini true, host_writable, &spte); 2871d786c778SPaolo Bonzini 2872d786c778SPaolo Bonzini if (*sptep == spte) { 2873d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2874d786c778SPaolo Bonzini } else { 2875d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 28765959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2877c50d8ae3SPaolo Bonzini } 2878c50d8ae3SPaolo Bonzini 2879ad67e480SPaolo Bonzini if (wrprot) { 2880c50d8ae3SPaolo Bonzini if (write_fault) 2881c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2882c50d8ae3SPaolo Bonzini } 2883c50d8ae3SPaolo Bonzini 2884d786c778SPaolo Bonzini if (flush) 2885c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 2886c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(level)); 2887c50d8ae3SPaolo Bonzini 2888c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2889c50d8ae3SPaolo Bonzini 2890c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2891d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 28926a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 28936a97575dSDavid Matlack } else { 28946a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 289579e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2896c50d8ae3SPaolo Bonzini } 2897c50d8ae3SPaolo Bonzini 2898c50d8ae3SPaolo Bonzini return ret; 2899c50d8ae3SPaolo Bonzini } 2900c50d8ae3SPaolo Bonzini 2901c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2902c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2903c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2904c50d8ae3SPaolo Bonzini { 2905c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2906c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 29070a2b64c5SBen Gardon unsigned int access = sp->role.access; 2908c50d8ae3SPaolo Bonzini int i, ret; 2909c50d8ae3SPaolo Bonzini gfn_t gfn; 2910c50d8ae3SPaolo Bonzini 291179e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 2912c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2913c50d8ae3SPaolo Bonzini if (!slot) 2914c50d8ae3SPaolo Bonzini return -1; 2915c50d8ae3SPaolo Bonzini 2916c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2917c50d8ae3SPaolo Bonzini if (ret <= 0) 2918c50d8ae3SPaolo Bonzini return -1; 2919c50d8ae3SPaolo Bonzini 2920c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 29218a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2922a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2923c50d8ae3SPaolo Bonzini put_page(pages[i]); 2924c50d8ae3SPaolo Bonzini } 2925c50d8ae3SPaolo Bonzini 2926c50d8ae3SPaolo Bonzini return 0; 2927c50d8ae3SPaolo Bonzini } 2928c50d8ae3SPaolo Bonzini 2929c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 2930c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 2931c50d8ae3SPaolo Bonzini { 2932c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 2933c50d8ae3SPaolo Bonzini int i; 2934c50d8ae3SPaolo Bonzini 2935c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 2936c50d8ae3SPaolo Bonzini 293779e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 2938c50d8ae3SPaolo Bonzini spte = sp->spt + i; 2939c50d8ae3SPaolo Bonzini 2940c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 2941c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 2942c50d8ae3SPaolo Bonzini if (!start) 2943c50d8ae3SPaolo Bonzini continue; 2944c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 2945c6cecc4bSSean Christopherson return; 2946c50d8ae3SPaolo Bonzini start = NULL; 2947c50d8ae3SPaolo Bonzini } else if (!start) 2948c50d8ae3SPaolo Bonzini start = spte; 2949c50d8ae3SPaolo Bonzini } 2950c6cecc4bSSean Christopherson if (start) 2951c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 2952c50d8ae3SPaolo Bonzini } 2953c50d8ae3SPaolo Bonzini 2954c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 2955c50d8ae3SPaolo Bonzini { 2956c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2957c50d8ae3SPaolo Bonzini 295857354682SSean Christopherson sp = sptep_to_sp(sptep); 2959c50d8ae3SPaolo Bonzini 2960c50d8ae3SPaolo Bonzini /* 2961c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 2962c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 2963c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 2964c50d8ae3SPaolo Bonzini */ 2965c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 2966c50d8ae3SPaolo Bonzini return; 2967c50d8ae3SPaolo Bonzini 29683bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 2969c50d8ae3SPaolo Bonzini return; 2970c50d8ae3SPaolo Bonzini 29714a42d848SDavid Stevens /* 29724a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 29734a42d848SDavid Stevens * accidentally prefetching those addresses. 29744a42d848SDavid Stevens */ 297520ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 29764a42d848SDavid Stevens return; 29774a42d848SDavid Stevens 2978c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 2979c50d8ae3SPaolo Bonzini } 2980c50d8ae3SPaolo Bonzini 298165e3b446SSean Christopherson /* 298265e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 298365e3b446SSean Christopherson * 298465e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 298565e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 298665e3b446SSean Christopherson * 298765e3b446SSean Christopherson * There are several ways to safely use this helper: 298865e3b446SSean Christopherson * 298920ec3ebdSChao Peng * - Check mmu_invalidate_retry_hva() after grabbing the mapping level, before 299065e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 299165e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 299265e3b446SSean Christopherson * 299365e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 299465e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 299565e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 299665e3b446SSean Christopherson * 299765e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 299865e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 299965e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 300065e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 300165e3b446SSean Christopherson * 300265e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 300365e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 300465e3b446SSean Christopherson * race with the primary MMU occurs. 300565e3b446SSean Christopherson */ 3006a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 30078ca6f063SBen Gardon const struct kvm_memory_slot *slot) 3008db543216SSean Christopherson { 3009284dc493SSean Christopherson int level = PG_LEVEL_4K; 3010db543216SSean Christopherson unsigned long hva; 301144187235SMingwei Zhang unsigned long flags; 301244187235SMingwei Zhang pgd_t pgd; 301344187235SMingwei Zhang p4d_t p4d; 301444187235SMingwei Zhang pud_t pud; 301544187235SMingwei Zhang pmd_t pmd; 3016db543216SSean Christopherson 30175d49f08cSSean Christopherson /* 3018293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 3019293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 3020293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 3021293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 3022293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 3023293e306eSSean Christopherson * read-only memslot. 3024293e306eSSean Christopherson */ 3025db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 3026db543216SSean Christopherson 302744187235SMingwei Zhang /* 302865e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 302965e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 303065e3b446SSean Christopherson * the original page table. 303144187235SMingwei Zhang */ 303244187235SMingwei Zhang local_irq_save(flags); 3033db543216SSean Christopherson 303465e3b446SSean Christopherson /* 303565e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 303665e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 303765e3b446SSean Christopherson * walk into the weeks, e.g. p*d_large() returns false (sees the old 303865e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 303965e3b446SSean Christopherson * of the old page table (sees the new value). 304065e3b446SSean Christopherson */ 304144187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 304244187235SMingwei Zhang if (pgd_none(pgd)) 304344187235SMingwei Zhang goto out; 304444187235SMingwei Zhang 304544187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 304644187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 304744187235SMingwei Zhang goto out; 304844187235SMingwei Zhang 304944187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 305044187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 305144187235SMingwei Zhang goto out; 305244187235SMingwei Zhang 305344187235SMingwei Zhang if (pud_large(pud)) { 305444187235SMingwei Zhang level = PG_LEVEL_1G; 305544187235SMingwei Zhang goto out; 305644187235SMingwei Zhang } 305744187235SMingwei Zhang 305844187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 305944187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 306044187235SMingwei Zhang goto out; 306144187235SMingwei Zhang 306244187235SMingwei Zhang if (pmd_large(pmd)) 306344187235SMingwei Zhang level = PG_LEVEL_2M; 306444187235SMingwei Zhang 306544187235SMingwei Zhang out: 306644187235SMingwei Zhang local_irq_restore(flags); 3067db543216SSean Christopherson return level; 3068db543216SSean Christopherson } 3069db543216SSean Christopherson 30708ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 30718ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 3072a8ac499bSSean Christopherson int max_level) 30731b6d9d9eSSean Christopherson { 30741b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3075ec607a56SPaolo Bonzini int host_level; 30761b6d9d9eSSean Christopherson 30771b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 30781b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 30791b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 30801b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 30811b6d9d9eSSean Christopherson break; 30821b6d9d9eSSean Christopherson } 30831b6d9d9eSSean Christopherson 30841b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 30851b6d9d9eSSean Christopherson return PG_LEVEL_4K; 30861b6d9d9eSSean Christopherson 3087a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3088ec607a56SPaolo Bonzini return min(host_level, max_level); 30891b6d9d9eSSean Christopherson } 30901b6d9d9eSSean Christopherson 309173a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 30920885904dSSean Christopherson { 3093e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 309417eff019SSean Christopherson kvm_pfn_t mask; 30950885904dSSean Christopherson 309673a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 30973cf06612SSean Christopherson 309873a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 309973a3c659SPaolo Bonzini return; 310017eff019SSean Christopherson 31015d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 310273a3c659SPaolo Bonzini return; 310317eff019SSean Christopherson 3104e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 310573a3c659SPaolo Bonzini return; 3106293e306eSSean Christopherson 31073cf06612SSean Christopherson /* 31083cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 31093cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 31103cf06612SSean Christopherson */ 311173a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 3112a8ac499bSSean Christopherson fault->gfn, fault->max_level); 311373a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 311473a3c659SPaolo Bonzini return; 31154cd071d1SSean Christopherson 31160885904dSSean Christopherson /* 311720ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 31184cd071d1SSean Christopherson * the pmd can't be split from under us. 31190885904dSSean Christopherson */ 312073a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 312173a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 312273a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 312373a3c659SPaolo Bonzini fault->pfn &= ~mask; 31240885904dSSean Christopherson } 31250885904dSSean Christopherson 3126536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3127c50d8ae3SPaolo Bonzini { 3128536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3129536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3130c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 313176901e56SMingwei Zhang !is_large_pte(spte) && 313276901e56SMingwei Zhang spte_to_child_sp(spte)->nx_huge_page_disallowed) { 3133c50d8ae3SPaolo Bonzini /* 3134c50d8ae3SPaolo Bonzini * A small SPTE exists for this pfn, but FNAME(fetch) 3135c50d8ae3SPaolo Bonzini * and __direct_map would like to create a large PTE 3136c50d8ae3SPaolo Bonzini * instead: just force them to go down another level, 3137c50d8ae3SPaolo Bonzini * patching back for them into pfn the next 9 bits of 3138c50d8ae3SPaolo Bonzini * the address. 3139c50d8ae3SPaolo Bonzini */ 3140536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3141536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3142536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3143536f0e6aSPaolo Bonzini fault->goal_level--; 3144c50d8ae3SPaolo Bonzini } 3145c50d8ae3SPaolo Bonzini } 3146c50d8ae3SPaolo Bonzini 314743b74355SPaolo Bonzini static int __direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3148c50d8ae3SPaolo Bonzini { 3149c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3150c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 315173a3c659SPaolo Bonzini int ret; 315243b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3153c50d8ae3SPaolo Bonzini 315473a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 31554cd071d1SSean Christopherson 3156f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 315743b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3158c50d8ae3SPaolo Bonzini /* 3159c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3160c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3161c50d8ae3SPaolo Bonzini */ 316273a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3163536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3164c50d8ae3SPaolo Bonzini 316543b74355SPaolo Bonzini base_gfn = fault->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); 316673a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3167c50d8ae3SPaolo Bonzini break; 3168c50d8ae3SPaolo Bonzini 31692e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 31700cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 31710cd8dc73SPaolo Bonzini continue; 3172c50d8ae3SPaolo Bonzini 3173c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 3174b5b0977fSSean Christopherson if (fault->huge_page_disallowed) 317555c510e2SSean Christopherson account_nx_huge_page(vcpu->kvm, sp, 3176428e9216SSean Christopherson fault->req_level >= it.level); 3177c50d8ae3SPaolo Bonzini } 3178c50d8ae3SPaolo Bonzini 3179b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3180b1a429fbSSean Christopherson return -EFAULT; 3181b1a429fbSSean Christopherson 31828a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3183a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 318412703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 318512703759SSean Christopherson return ret; 318612703759SSean Christopherson 3187c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3188c50d8ae3SPaolo Bonzini return ret; 3189c50d8ae3SPaolo Bonzini } 3190c50d8ae3SPaolo Bonzini 3191cd08d178SDavid Matlack static void kvm_send_hwpoison_signal(struct kvm_memory_slot *slot, gfn_t gfn) 3192c50d8ae3SPaolo Bonzini { 3193cd08d178SDavid Matlack unsigned long hva = gfn_to_hva_memslot(slot, gfn); 3194cd08d178SDavid Matlack 3195cd08d178SDavid Matlack send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); 3196c50d8ae3SPaolo Bonzini } 3197c50d8ae3SPaolo Bonzini 3198cd08d178SDavid Matlack static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3199c50d8ae3SPaolo Bonzini { 3200cd08d178SDavid Matlack if (is_sigpending_pfn(fault->pfn)) { 320176657687SPeter Xu kvm_handle_signal_exit(vcpu); 320276657687SPeter Xu return -EINTR; 320376657687SPeter Xu } 320476657687SPeter Xu 3205c50d8ae3SPaolo Bonzini /* 3206c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3207c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3208c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3209c50d8ae3SPaolo Bonzini */ 3210cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_RO_FAULT) 3211c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3212c50d8ae3SPaolo Bonzini 3213cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_HWPOISON) { 3214cd08d178SDavid Matlack kvm_send_hwpoison_signal(fault->slot, fault->gfn); 3215c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3216c50d8ae3SPaolo Bonzini } 3217c50d8ae3SPaolo Bonzini 3218c50d8ae3SPaolo Bonzini return -EFAULT; 3219c50d8ae3SPaolo Bonzini } 3220c50d8ae3SPaolo Bonzini 3221354c908cSDavid Matlack static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu, 3222354c908cSDavid Matlack struct kvm_page_fault *fault, 32235276c616SSean Christopherson unsigned int access) 3224c50d8ae3SPaolo Bonzini { 32253a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 32263a13f4feSPaolo Bonzini 32273a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3228c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 3229354c908cSDavid Matlack 323030ab5901SSean Christopherson /* 323130ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 323230ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 3233354c908cSDavid Matlack * MMIO SPTE will just be an expensive nop. 323430ab5901SSean Christopherson */ 3235354c908cSDavid Matlack if (unlikely(!enable_mmio_caching)) 32365276c616SSean Christopherson return RET_PF_EMULATE; 3237354c908cSDavid Matlack 3238354c908cSDavid Matlack /* 3239354c908cSDavid Matlack * Do not create an MMIO SPTE for a gfn greater than host.MAXPHYADDR, 3240354c908cSDavid Matlack * any guest that generates such gfns is running nested and is being 3241354c908cSDavid Matlack * tricked by L0 userspace (you can observe gfn > L1.MAXPHYADDR if and 3242354c908cSDavid Matlack * only if L1's MAXPHYADDR is inaccurate with respect to the 3243354c908cSDavid Matlack * hardware's). 3244354c908cSDavid Matlack */ 3245354c908cSDavid Matlack if (unlikely(fault->gfn > kvm_mmu_max_gfn())) 3246354c908cSDavid Matlack return RET_PF_EMULATE; 3247c50d8ae3SPaolo Bonzini 32485276c616SSean Christopherson return RET_PF_CONTINUE; 3249c50d8ae3SPaolo Bonzini } 3250c50d8ae3SPaolo Bonzini 32513c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3252c50d8ae3SPaolo Bonzini { 3253c50d8ae3SPaolo Bonzini /* 32545c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 32555c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 32565c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 32575c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3258c50d8ae3SPaolo Bonzini */ 32593c8ad5a6SPaolo Bonzini if (fault->rsvd) 3260c50d8ae3SPaolo Bonzini return false; 3261c50d8ae3SPaolo Bonzini 3262c50d8ae3SPaolo Bonzini /* 3263c50d8ae3SPaolo Bonzini * #PF can be fast if: 3264c50d8ae3SPaolo Bonzini * 326554275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 326654275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 326754275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 326854275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 326954275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 327054275f74SSean Christopherson * mechanism only supports direct MMUs. 327154275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 327254275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 327354275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 327454275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 327554275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3276c50d8ae3SPaolo Bonzini */ 32775c64aba5SSean Christopherson if (!fault->present) 32785c64aba5SSean Christopherson return !kvm_ad_enabled(); 32795c64aba5SSean Christopherson 32805c64aba5SSean Christopherson /* 32815c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 32825c64aba5SSean Christopherson * the "exec" flag. 32835c64aba5SSean Christopherson */ 32845c64aba5SSean Christopherson return fault->write; 3285c50d8ae3SPaolo Bonzini } 3286c50d8ae3SPaolo Bonzini 3287c50d8ae3SPaolo Bonzini /* 3288c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3289c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3290c50d8ae3SPaolo Bonzini */ 3291c50d8ae3SPaolo Bonzini static bool 3292e710c5f6SDavid Matlack fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 3293c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3294c50d8ae3SPaolo Bonzini { 3295c50d8ae3SPaolo Bonzini /* 3296c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3297c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3298c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3299c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3300c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3301c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3302c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3303c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3304c50d8ae3SPaolo Bonzini * 3305c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3306c50d8ae3SPaolo Bonzini */ 33072db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3308c50d8ae3SPaolo Bonzini return false; 3309c50d8ae3SPaolo Bonzini 3310e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3311e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3312c50d8ae3SPaolo Bonzini 3313c50d8ae3SPaolo Bonzini return true; 3314c50d8ae3SPaolo Bonzini } 3315c50d8ae3SPaolo Bonzini 33163c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3317c50d8ae3SPaolo Bonzini { 33183c8ad5a6SPaolo Bonzini if (fault->exec) 3319c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3320c50d8ae3SPaolo Bonzini 33213c8ad5a6SPaolo Bonzini if (fault->write) 3322c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3323c50d8ae3SPaolo Bonzini 3324c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3325c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3326c50d8ae3SPaolo Bonzini } 3327c50d8ae3SPaolo Bonzini 3328c50d8ae3SPaolo Bonzini /* 33296e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 33306e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 33316e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 33326e8eb206SDavid Matlack * 33336e8eb206SDavid Matlack * Contract: 33346e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 33356e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 33366e8eb206SDavid Matlack */ 33376e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 33386e8eb206SDavid Matlack { 33396e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 33406e8eb206SDavid Matlack u64 old_spte; 33416e8eb206SDavid Matlack u64 *sptep = NULL; 33426e8eb206SDavid Matlack 33436e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 33446e8eb206SDavid Matlack sptep = iterator.sptep; 33456e8eb206SDavid Matlack *spte = old_spte; 33466e8eb206SDavid Matlack } 33476e8eb206SDavid Matlack 33486e8eb206SDavid Matlack return sptep; 33496e8eb206SDavid Matlack } 33506e8eb206SDavid Matlack 33516e8eb206SDavid Matlack /* 3352c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3353c50d8ae3SPaolo Bonzini */ 33543c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3355c50d8ae3SPaolo Bonzini { 3356c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3357c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3358c50d8ae3SPaolo Bonzini u64 spte = 0ull; 33596e8eb206SDavid Matlack u64 *sptep = NULL; 3360c50d8ae3SPaolo Bonzini uint retry_count = 0; 3361c50d8ae3SPaolo Bonzini 33623c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3363c4371c2aSSean Christopherson return ret; 3364c50d8ae3SPaolo Bonzini 3365c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3366c50d8ae3SPaolo Bonzini 3367c50d8ae3SPaolo Bonzini do { 3368c50d8ae3SPaolo Bonzini u64 new_spte; 3369c50d8ae3SPaolo Bonzini 33706e8eb206SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 33713c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 33726e8eb206SDavid Matlack else 33733c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3374c50d8ae3SPaolo Bonzini 3375ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3376ec89e643SSean Christopherson break; 3377ec89e643SSean Christopherson 33786e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3379c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3380c50d8ae3SPaolo Bonzini break; 3381c50d8ae3SPaolo Bonzini 3382c50d8ae3SPaolo Bonzini /* 3383c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3384c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3385c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3386c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3387c50d8ae3SPaolo Bonzini * current CPU took the fault. 3388c50d8ae3SPaolo Bonzini * 3389c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3390c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3391c50d8ae3SPaolo Bonzini */ 33923c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3393c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3394c50d8ae3SPaolo Bonzini break; 3395c50d8ae3SPaolo Bonzini } 3396c50d8ae3SPaolo Bonzini 3397c50d8ae3SPaolo Bonzini new_spte = spte; 3398c50d8ae3SPaolo Bonzini 339954275f74SSean Christopherson /* 340054275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 340154275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 340254275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 340354275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 340454275f74SSean Christopherson */ 340554275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3406c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3407c50d8ae3SPaolo Bonzini 3408c50d8ae3SPaolo Bonzini /* 340954275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 341054275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 341154275f74SSean Christopherson * that were write-protected for dirty-logging or access 341254275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 341354275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 341454275f74SSean Christopherson * The is_access_allowed() check above handles the common case 341554275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 341654275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 341754275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3418c50d8ae3SPaolo Bonzini */ 3419706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3420c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3421c50d8ae3SPaolo Bonzini 3422c50d8ae3SPaolo Bonzini /* 342310c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 342410c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 342510c30de0SJunaid Shahid * first page into the dirty-bitmap in 3426c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3427c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3428c50d8ae3SPaolo Bonzini * 3429c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3430c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3431c50d8ae3SPaolo Bonzini */ 343210c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 343310c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3434c50d8ae3SPaolo Bonzini break; 3435c50d8ae3SPaolo Bonzini } 3436c50d8ae3SPaolo Bonzini 3437c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3438c50d8ae3SPaolo Bonzini if (new_spte == spte || 34393c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3440c50d8ae3SPaolo Bonzini break; 3441c50d8ae3SPaolo Bonzini 3442c50d8ae3SPaolo Bonzini /* 3443c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3444c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 34453ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3446c50d8ae3SPaolo Bonzini */ 3447e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3448c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3449c50d8ae3SPaolo Bonzini break; 3450c4371c2aSSean Christopherson } 3451c50d8ae3SPaolo Bonzini 3452c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 3453c50d8ae3SPaolo Bonzini printk_once(KERN_WARNING 3454c50d8ae3SPaolo Bonzini "kvm: Fast #PF retrying more than 4 times.\n"); 3455c50d8ae3SPaolo Bonzini break; 3456c50d8ae3SPaolo Bonzini } 3457c50d8ae3SPaolo Bonzini 3458c50d8ae3SPaolo Bonzini } while (true); 3459c50d8ae3SPaolo Bonzini 3460f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3461c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3462c50d8ae3SPaolo Bonzini 34631075d41eSSean Christopherson if (ret != RET_PF_INVALID) 34641075d41eSSean Christopherson vcpu->stat.pf_fast++; 34651075d41eSSean Christopherson 3466c4371c2aSSean Christopherson return ret; 3467c50d8ae3SPaolo Bonzini } 3468c50d8ae3SPaolo Bonzini 3469c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3470c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3471c50d8ae3SPaolo Bonzini { 3472c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3473c50d8ae3SPaolo Bonzini 3474c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3475c50d8ae3SPaolo Bonzini return; 3476c50d8ae3SPaolo Bonzini 34775e3edd7eSSean Christopherson /* 34785e3edd7eSSean Christopherson * The "root" may be a special root, e.g. a PAE entry, treat it as a 34795e3edd7eSSean Christopherson * SPTE to ensure any non-PA bits are dropped. 34805e3edd7eSSean Christopherson */ 34815e3edd7eSSean Christopherson sp = spte_to_child_sp(*root_hpa); 34829191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 34839191b8f0SPaolo Bonzini return; 348402c00b3aSBen Gardon 3485897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 34866103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 348776eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3488c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3489c50d8ae3SPaolo Bonzini 3490c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3491c50d8ae3SPaolo Bonzini } 3492c50d8ae3SPaolo Bonzini 3493c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 34940c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3495c50d8ae3SPaolo Bonzini ulong roots_to_free) 3496c50d8ae3SPaolo Bonzini { 3497c50d8ae3SPaolo Bonzini int i; 3498c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3499594bef79SPaolo Bonzini bool free_active_root; 3500c50d8ae3SPaolo Bonzini 3501c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3502c50d8ae3SPaolo Bonzini 3503c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3504594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3505594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3506594bef79SPaolo Bonzini 3507594bef79SPaolo Bonzini if (!free_active_root) { 3508c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3509c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3510c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3511c50d8ae3SPaolo Bonzini break; 3512c50d8ae3SPaolo Bonzini 3513c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3514c50d8ae3SPaolo Bonzini return; 3515c50d8ae3SPaolo Bonzini } 3516c50d8ae3SPaolo Bonzini 3517531810caSBen Gardon write_lock(&kvm->mmu_lock); 3518c50d8ae3SPaolo Bonzini 3519c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3520c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 35214d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3522c50d8ae3SPaolo Bonzini &invalid_list); 3523c50d8ae3SPaolo Bonzini 3524c50d8ae3SPaolo Bonzini if (free_active_root) { 3525594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3526b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 352704d45551SSean Christopherson } else if (mmu->pae_root) { 3528c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3529c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3530c834e5e4SSean Christopherson continue; 3531c834e5e4SSean Christopherson 3532c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3533c50d8ae3SPaolo Bonzini &invalid_list); 3534c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3535c50d8ae3SPaolo Bonzini } 3536c50d8ae3SPaolo Bonzini } 3537b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3538b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3539c50d8ae3SPaolo Bonzini } 3540c50d8ae3SPaolo Bonzini 35414d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3542531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3543c50d8ae3SPaolo Bonzini } 3544c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3545c50d8ae3SPaolo Bonzini 35460c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 354725b62c62SSean Christopherson { 354825b62c62SSean Christopherson unsigned long roots_to_free = 0; 354925b62c62SSean Christopherson hpa_t root_hpa; 355025b62c62SSean Christopherson int i; 355125b62c62SSean Christopherson 355225b62c62SSean Christopherson /* 355325b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 355425b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 355525b62c62SSean Christopherson */ 35567a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 355725b62c62SSean Christopherson 355825b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 355925b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 356025b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 356125b62c62SSean Christopherson continue; 356225b62c62SSean Christopherson 356325b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 356425b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 356525b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 356625b62c62SSean Christopherson } 356725b62c62SSean Christopherson 35680c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 356925b62c62SSean Christopherson } 357025b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 357125b62c62SSean Christopherson 357225b62c62SSean Christopherson 3573c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3574c50d8ae3SPaolo Bonzini { 3575c50d8ae3SPaolo Bonzini int ret = 0; 3576c50d8ae3SPaolo Bonzini 3577995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3578c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3579c50d8ae3SPaolo Bonzini ret = 1; 3580c50d8ae3SPaolo Bonzini } 3581c50d8ae3SPaolo Bonzini 3582c50d8ae3SPaolo Bonzini return ret; 3583c50d8ae3SPaolo Bonzini } 3584c50d8ae3SPaolo Bonzini 35852e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 358686938ab6SDavid Matlack u8 level) 3587c50d8ae3SPaolo Bonzini { 35882e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3589c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 35908123f265SSean Christopherson 35912e65e842SDavid Matlack role.level = level; 35922e65e842SDavid Matlack role.quadrant = quadrant; 35932e65e842SDavid Matlack 35947f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 35957f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 35967f497775SDavid Matlack 359787654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 35988123f265SSean Christopherson ++sp->root_count; 35998123f265SSean Christopherson 36008123f265SSean Christopherson return __pa(sp->spt); 36018123f265SSean Christopherson } 36028123f265SSean Christopherson 36038123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 36048123f265SSean Christopherson { 3605b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3606a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 36078123f265SSean Christopherson hpa_t root; 3608c50d8ae3SPaolo Bonzini unsigned i; 36094a38162eSPaolo Bonzini int r; 36104a38162eSPaolo Bonzini 36114a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36124a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36134a38162eSPaolo Bonzini if (r < 0) 36144a38162eSPaolo Bonzini goto out_unlock; 3615c50d8ae3SPaolo Bonzini 36161f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 361702c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3618b9e5603cSPaolo Bonzini mmu->root.hpa = root; 361902c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 362086938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3621b9e5603cSPaolo Bonzini mmu->root.hpa = root; 36228123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 36234a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 36244a38162eSPaolo Bonzini r = -EIO; 36254a38162eSPaolo Bonzini goto out_unlock; 36264a38162eSPaolo Bonzini } 362773ad1606SSean Christopherson 3628c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3629c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3630c50d8ae3SPaolo Bonzini 36317f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 36322e65e842SDavid Matlack PT32_ROOT_LEVEL); 363317e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3634d2263de1SYuan Yao shadow_me_value; 3635c50d8ae3SPaolo Bonzini } 3636b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 363773ad1606SSean Christopherson } else { 363873ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 36394a38162eSPaolo Bonzini r = -EIO; 36404a38162eSPaolo Bonzini goto out_unlock; 364173ad1606SSean Christopherson } 36423651c7fcSSean Christopherson 3643b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3644b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 36454a38162eSPaolo Bonzini out_unlock: 36464a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 36474a38162eSPaolo Bonzini return r; 3648c50d8ae3SPaolo Bonzini } 3649c50d8ae3SPaolo Bonzini 36501e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 36511e76a3ceSDavid Stevens { 36521e76a3ceSDavid Stevens struct kvm_memslots *slots; 36531e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3654a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 36551e76a3ceSDavid Stevens 36561e76a3ceSDavid Stevens /* 36571e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 36581e76a3ceSDavid Stevens * taking the lock. 36591e76a3ceSDavid Stevens */ 36601e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 36611e76a3ceSDavid Stevens return 0; 36621e76a3ceSDavid Stevens 36631e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 36641e76a3ceSDavid Stevens 36651e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 36661e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 36671e76a3ceSDavid Stevens goto out_unlock; 36681e76a3ceSDavid Stevens 36691e76a3ceSDavid Stevens /* 36701e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 36711e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 36721e76a3ceSDavid Stevens */ 36731e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 36741e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 36751e76a3ceSDavid Stevens goto out_success; 36761e76a3ceSDavid Stevens 36771e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 36781e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3679a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 36801e76a3ceSDavid Stevens /* 36811e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 36821e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 36831e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 36841e76a3ceSDavid Stevens * failure to avoid having to track which allocations 36851e76a3ceSDavid Stevens * were made now versus when the memslot was created. 36861e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 36871e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 36881e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 36891e76a3ceSDavid Stevens */ 36901e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 36911e76a3ceSDavid Stevens if (r) 36921e76a3ceSDavid Stevens goto out_unlock; 36931e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 36941e76a3ceSDavid Stevens if (r) 36951e76a3ceSDavid Stevens goto out_unlock; 36961e76a3ceSDavid Stevens } 36971e76a3ceSDavid Stevens } 36981e76a3ceSDavid Stevens 36991e76a3ceSDavid Stevens /* 37001e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 37011e76a3ceSDavid Stevens * all the related pointers are set. 37021e76a3ceSDavid Stevens */ 37031e76a3ceSDavid Stevens out_success: 37041e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 37051e76a3ceSDavid Stevens 37061e76a3ceSDavid Stevens out_unlock: 37071e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 37081e76a3ceSDavid Stevens return r; 37091e76a3ceSDavid Stevens } 37101e76a3ceSDavid Stevens 3711c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3712c50d8ae3SPaolo Bonzini { 3713b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 37146e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3715be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 37167f497775SDavid Matlack int quadrant, i, r; 37178123f265SSean Christopherson hpa_t root; 3718c50d8ae3SPaolo Bonzini 3719b37233c9SSean Christopherson root_pgd = mmu->get_guest_pgd(vcpu); 3720be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3721c50d8ae3SPaolo Bonzini 3722c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3723c50d8ae3SPaolo Bonzini return 1; 3724c50d8ae3SPaolo Bonzini 3725c50d8ae3SPaolo Bonzini /* 37264a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 37274a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 37284a38162eSPaolo Bonzini */ 37294d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 37306e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 37316e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 37326e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 37336e0918aeSSean Christopherson continue; 37346e0918aeSSean Christopherson 37356e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 37366e0918aeSSean Christopherson return 1; 37376e0918aeSSean Christopherson } 37386e0918aeSSean Christopherson } 37396e0918aeSSean Christopherson 37401e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3741d501f747SBen Gardon if (r) 3742d501f747SBen Gardon return r; 3743d501f747SBen Gardon 37444a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 37454a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 37464a38162eSPaolo Bonzini if (r < 0) 37474a38162eSPaolo Bonzini goto out_unlock; 37484a38162eSPaolo Bonzini 3749c50d8ae3SPaolo Bonzini /* 3750c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3751c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3752c50d8ae3SPaolo Bonzini */ 37534d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 37548123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 375586938ab6SDavid Matlack mmu->root_role.level); 3756b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3757be01e8e2SSean Christopherson goto set_root_pgd; 3758c50d8ae3SPaolo Bonzini } 3759c50d8ae3SPaolo Bonzini 37604a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 37614a38162eSPaolo Bonzini r = -EIO; 37624a38162eSPaolo Bonzini goto out_unlock; 37634a38162eSPaolo Bonzini } 376473ad1606SSean Christopherson 3765c50d8ae3SPaolo Bonzini /* 3766c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3767c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3768c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3769c50d8ae3SPaolo Bonzini */ 3770e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3771a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3772c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3773c50d8ae3SPaolo Bonzini 377403ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 37754a38162eSPaolo Bonzini r = -EIO; 37764a38162eSPaolo Bonzini goto out_unlock; 37774a38162eSPaolo Bonzini } 377803ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3779cb0f722aSWei Huang 3780a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3781cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3782cb0f722aSWei Huang r = -EIO; 3783cb0f722aSWei Huang goto out_unlock; 3784cb0f722aSWei Huang } 3785cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3786cb0f722aSWei Huang } 378704d45551SSean Christopherson } 378804d45551SSean Christopherson 3789c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3790c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 37916e6ec584SSean Christopherson 37924d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 37936e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3794c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3795c50d8ae3SPaolo Bonzini continue; 3796c50d8ae3SPaolo Bonzini } 37976e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3798c50d8ae3SPaolo Bonzini } 3799c50d8ae3SPaolo Bonzini 38007f497775SDavid Matlack /* 38017f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 38027f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 38037f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 38047f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 38057f497775SDavid Matlack */ 38067f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 38077f497775SDavid Matlack 38087f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3809b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3810c50d8ae3SPaolo Bonzini } 3811c50d8ae3SPaolo Bonzini 3812a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3813b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3814a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3815b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3816ba0a194fSSean Christopherson else 3817b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3818c50d8ae3SPaolo Bonzini 3819be01e8e2SSean Christopherson set_root_pgd: 3820b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 38214a38162eSPaolo Bonzini out_unlock: 38224a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3823c50d8ae3SPaolo Bonzini 3824c6c937d6SLike Xu return r; 3825c50d8ae3SPaolo Bonzini } 3826c50d8ae3SPaolo Bonzini 3827748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3828c50d8ae3SPaolo Bonzini { 3829748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3830a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3831cb0f722aSWei Huang u64 *pml5_root = NULL; 3832cb0f722aSWei Huang u64 *pml4_root = NULL; 3833cb0f722aSWei Huang u64 *pae_root; 3834748e52b9SSean Christopherson 3835748e52b9SSean Christopherson /* 3836748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3837748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3838748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3839748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3840748e52b9SSean Christopherson */ 3841347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3842347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3843a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3844748e52b9SSean Christopherson return 0; 3845748e52b9SSean Christopherson 3846a717a780SSean Christopherson /* 3847a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3848a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3849a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3850a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3851a717a780SSean Christopherson * prior MMU would also have required pml5. 3852a717a780SSean Christopherson */ 3853a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3854748e52b9SSean Christopherson return 0; 3855748e52b9SSean Christopherson 3856748e52b9SSean Christopherson /* 3857748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3858748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3859748e52b9SSean Christopherson */ 3860cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3861a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3862748e52b9SSean Christopherson return -EIO; 3863748e52b9SSean Christopherson 38644a98623dSSean Christopherson /* 38654a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 38664a98623dSSean Christopherson * doesn't need to be decrypted. 38674a98623dSSean Christopherson */ 3868748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3869748e52b9SSean Christopherson if (!pae_root) 3870748e52b9SSean Christopherson return -ENOMEM; 3871748e52b9SSean Christopherson 3872cb0f722aSWei Huang #ifdef CONFIG_X86_64 387303ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3874cb0f722aSWei Huang if (!pml4_root) 3875cb0f722aSWei Huang goto err_pml4; 3876cb0f722aSWei Huang 3877a717a780SSean Christopherson if (need_pml5) { 3878cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3879cb0f722aSWei Huang if (!pml5_root) 3880cb0f722aSWei Huang goto err_pml5; 3881748e52b9SSean Christopherson } 3882cb0f722aSWei Huang #endif 3883748e52b9SSean Christopherson 3884748e52b9SSean Christopherson mmu->pae_root = pae_root; 388503ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3886cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3887748e52b9SSean Christopherson 3888748e52b9SSean Christopherson return 0; 3889cb0f722aSWei Huang 3890cb0f722aSWei Huang #ifdef CONFIG_X86_64 3891cb0f722aSWei Huang err_pml5: 3892cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3893cb0f722aSWei Huang err_pml4: 3894cb0f722aSWei Huang free_page((unsigned long)pae_root); 3895cb0f722aSWei Huang return -ENOMEM; 3896cb0f722aSWei Huang #endif 3897c50d8ae3SPaolo Bonzini } 3898c50d8ae3SPaolo Bonzini 3899264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3900264d3dc1SLai Jiangshan { 3901264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3902264d3dc1SLai Jiangshan 390361b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 390461b05a9fSLai Jiangshan return false; 390561b05a9fSLai Jiangshan 3906264d3dc1SLai Jiangshan /* 3907264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3908264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3909264d3dc1SLai Jiangshan * 3910264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3911264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3912264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3913264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3914264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3915264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3916264d3dc1SLai Jiangshan * requirement isn't satisfied. 3917264d3dc1SLai Jiangshan */ 3918264d3dc1SLai Jiangshan smp_rmb(); 3919264d3dc1SLai Jiangshan sp = to_shadow_page(root); 39205d6a3221SSean Christopherson 39215d6a3221SSean Christopherson /* 39225d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 39235d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 39245d6a3221SSean Christopherson */ 39255d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 39265d6a3221SSean Christopherson return false; 39275d6a3221SSean Christopherson 3928264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 3929264d3dc1SLai Jiangshan return true; 3930264d3dc1SLai Jiangshan 3931264d3dc1SLai Jiangshan return false; 3932264d3dc1SLai Jiangshan } 3933264d3dc1SLai Jiangshan 3934c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 3935c50d8ae3SPaolo Bonzini { 3936c50d8ae3SPaolo Bonzini int i; 3937c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3938c50d8ae3SPaolo Bonzini 3939347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 3940c50d8ae3SPaolo Bonzini return; 3941c50d8ae3SPaolo Bonzini 3942b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 3943c50d8ae3SPaolo Bonzini return; 3944c50d8ae3SPaolo Bonzini 3945c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 3946c50d8ae3SPaolo Bonzini 39474d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 3948b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 3949e47c4aeeSSean Christopherson sp = to_shadow_page(root); 3950c50d8ae3SPaolo Bonzini 3951264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 3952c50d8ae3SPaolo Bonzini return; 3953c50d8ae3SPaolo Bonzini 3954531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 395565855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3956531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3957c50d8ae3SPaolo Bonzini return; 3958c50d8ae3SPaolo Bonzini } 3959c50d8ae3SPaolo Bonzini 3960531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 3961c50d8ae3SPaolo Bonzini 3962c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3963c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 3964c50d8ae3SPaolo Bonzini 3965c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 39665e3edd7eSSean Christopherson sp = spte_to_child_sp(root); 396765855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 3968c50d8ae3SPaolo Bonzini } 3969c50d8ae3SPaolo Bonzini } 3970c50d8ae3SPaolo Bonzini 3971531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 3972c50d8ae3SPaolo Bonzini } 3973c50d8ae3SPaolo Bonzini 397461b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 397561b05a9fSLai Jiangshan { 397661b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 397761b05a9fSLai Jiangshan int i; 397861b05a9fSLai Jiangshan 397961b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 398061b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 398161b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 398261b05a9fSLai Jiangshan 398361b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 39840c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 398561b05a9fSLai Jiangshan } 398661b05a9fSLai Jiangshan 39871f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 39885b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 3989c50d8ae3SPaolo Bonzini struct x86_exception *exception) 3990c50d8ae3SPaolo Bonzini { 3991c50d8ae3SPaolo Bonzini if (exception) 3992c50d8ae3SPaolo Bonzini exception->error_code = 0; 3993c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 3994c50d8ae3SPaolo Bonzini } 3995c50d8ae3SPaolo Bonzini 3996c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 3997c50d8ae3SPaolo Bonzini { 3998c50d8ae3SPaolo Bonzini /* 3999c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 4000c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 4001c50d8ae3SPaolo Bonzini */ 4002c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 4003c50d8ae3SPaolo Bonzini return false; 4004c50d8ae3SPaolo Bonzini 4005c50d8ae3SPaolo Bonzini if (direct) 4006c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 4007c50d8ae3SPaolo Bonzini 4008c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 4009c50d8ae3SPaolo Bonzini } 4010c50d8ae3SPaolo Bonzini 401195fb5b02SBen Gardon /* 401295fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 401395fb5b02SBen Gardon * That SPTE may be non-present. 4014c5c8c7c5SDavid Matlack * 4015c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 401695fb5b02SBen Gardon */ 401739b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 4018c50d8ae3SPaolo Bonzini { 4019c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 40202aa07893SSean Christopherson int leaf = -1; 402195fb5b02SBen Gardon u64 spte; 4022c50d8ae3SPaolo Bonzini 402339b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 402439b4d43eSSean Christopherson *root_level = iterator.level; 4025c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 4026c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 402795fb5b02SBen Gardon leaf = iterator.level; 4028c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 4029c50d8ae3SPaolo Bonzini 4030dde81f94SSean Christopherson sptes[leaf] = spte; 403195fb5b02SBen Gardon } 403295fb5b02SBen Gardon 403395fb5b02SBen Gardon return leaf; 403495fb5b02SBen Gardon } 403595fb5b02SBen Gardon 40369aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 403795fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 403895fb5b02SBen Gardon { 4039dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 404095fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 404139b4d43eSSean Christopherson int root, leaf, level; 404295fb5b02SBen Gardon bool reserved = false; 404395fb5b02SBen Gardon 4044c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 4045c5c8c7c5SDavid Matlack 404663c0cac9SDavid Matlack if (is_tdp_mmu(vcpu->arch.mmu)) 404739b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 404895fb5b02SBen Gardon else 404939b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 405095fb5b02SBen Gardon 4051c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 4052c5c8c7c5SDavid Matlack 40532aa07893SSean Christopherson if (unlikely(leaf < 0)) { 40542aa07893SSean Christopherson *sptep = 0ull; 40552aa07893SSean Christopherson return reserved; 40562aa07893SSean Christopherson } 40572aa07893SSean Christopherson 40589aa41879SSean Christopherson *sptep = sptes[leaf]; 40599aa41879SSean Christopherson 40609aa41879SSean Christopherson /* 40619aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 40629aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 40639aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 40649aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 40659aa41879SSean Christopherson */ 40669aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 40679aa41879SSean Christopherson leaf++; 406895fb5b02SBen Gardon 406995fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 407095fb5b02SBen Gardon 40719aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4072961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4073c50d8ae3SPaolo Bonzini 4074c50d8ae3SPaolo Bonzini if (reserved) { 4075bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4076c50d8ae3SPaolo Bonzini __func__, addr); 407795fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4078bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4079bb4cdf3aSSean Christopherson sptes[level], level, 4080961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4081c50d8ae3SPaolo Bonzini } 4082ddce6208SSean Christopherson 4083c50d8ae3SPaolo Bonzini return reserved; 4084c50d8ae3SPaolo Bonzini } 4085c50d8ae3SPaolo Bonzini 4086c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4087c50d8ae3SPaolo Bonzini { 4088c50d8ae3SPaolo Bonzini u64 spte; 4089c50d8ae3SPaolo Bonzini bool reserved; 4090c50d8ae3SPaolo Bonzini 4091c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4092c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4093c50d8ae3SPaolo Bonzini 409495fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 4095c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 4096c50d8ae3SPaolo Bonzini return -EINVAL; 4097c50d8ae3SPaolo Bonzini 4098c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4099c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 41000a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4101c50d8ae3SPaolo Bonzini 4102c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4103c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4104c50d8ae3SPaolo Bonzini 4105c50d8ae3SPaolo Bonzini if (direct) 4106c50d8ae3SPaolo Bonzini addr = 0; 4107c50d8ae3SPaolo Bonzini 4108c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4109c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4110c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4111c50d8ae3SPaolo Bonzini } 4112c50d8ae3SPaolo Bonzini 4113c50d8ae3SPaolo Bonzini /* 4114c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4115c50d8ae3SPaolo Bonzini * the address. 4116c50d8ae3SPaolo Bonzini */ 4117c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4118c50d8ae3SPaolo Bonzini } 4119c50d8ae3SPaolo Bonzini 4120c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4121b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4122c50d8ae3SPaolo Bonzini { 4123b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4124c50d8ae3SPaolo Bonzini return false; 4125c50d8ae3SPaolo Bonzini 4126b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4127c50d8ae3SPaolo Bonzini return false; 4128c50d8ae3SPaolo Bonzini 4129c50d8ae3SPaolo Bonzini /* 4130c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4131c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4132c50d8ae3SPaolo Bonzini */ 41339d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 4134c50d8ae3SPaolo Bonzini return true; 4135c50d8ae3SPaolo Bonzini 4136c50d8ae3SPaolo Bonzini return false; 4137c50d8ae3SPaolo Bonzini } 4138c50d8ae3SPaolo Bonzini 4139c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4140c50d8ae3SPaolo Bonzini { 4141c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4142c50d8ae3SPaolo Bonzini u64 spte; 4143c50d8ae3SPaolo Bonzini 4144c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 41453e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4146c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4147c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4148c50d8ae3SPaolo Bonzini } 4149c50d8ae3SPaolo Bonzini 41506f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 41516f3c1fc5SLiang Zhang { 41526f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 41536f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 41546f3c1fc5SLiang Zhang 41556f3c1fc5SLiang Zhang if (id << 12 == 0) 41566f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 41576f3c1fc5SLiang Zhang 41586f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 41596f3c1fc5SLiang Zhang } 41606f3c1fc5SLiang Zhang 4161e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 41629f1a8526SSean Christopherson gfn_t gfn) 4163c50d8ae3SPaolo Bonzini { 4164c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4165c50d8ae3SPaolo Bonzini 41666f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4167c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4168347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 4169d8dd54e0SSean Christopherson arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); 4170c50d8ae3SPaolo Bonzini 41719f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 41729f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4173c50d8ae3SPaolo Bonzini } 4174c50d8ae3SPaolo Bonzini 41758a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 41768a009d5bSSean Christopherson { 41778a009d5bSSean Christopherson int r; 41788a009d5bSSean Christopherson 41798a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 41808a009d5bSSean Christopherson work->wakeup_all) 41818a009d5bSSean Christopherson return; 41828a009d5bSSean Christopherson 41838a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 41848a009d5bSSean Christopherson if (unlikely(r)) 41858a009d5bSSean Christopherson return; 41868a009d5bSSean Christopherson 41878a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 41888a009d5bSSean Christopherson work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu)) 41898a009d5bSSean Christopherson return; 41908a009d5bSSean Christopherson 41918a009d5bSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true); 41928a009d5bSSean Christopherson } 41938a009d5bSSean Christopherson 4194ba6e3fe2SDavid Matlack static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4195c50d8ae3SPaolo Bonzini { 4196e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4197c50d8ae3SPaolo Bonzini bool async; 4198c50d8ae3SPaolo Bonzini 4199e0c37868SSean Christopherson /* 4200e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4201e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4202e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4203e0c37868SSean Christopherson */ 4204e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 42055276c616SSean Christopherson return RET_PF_RETRY; 4206e0c37868SSean Christopherson 42079cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4208c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 42099cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4210e710c5f6SDavid Matlack fault->slot = NULL; 42113647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 42123647cd04SPaolo Bonzini fault->map_writable = false; 42135276c616SSean Christopherson return RET_PF_CONTINUE; 4214c50d8ae3SPaolo Bonzini } 42159cc13d60SMaxim Levitsky /* 42169cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 42179cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 42189cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 42199cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 42209cc13d60SMaxim Levitsky */ 42219cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 42225276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 42235276c616SSean Christopherson return RET_PF_EMULATE; 42249cc13d60SMaxim Levitsky } 4225c50d8ae3SPaolo Bonzini 4226c50d8ae3SPaolo Bonzini async = false; 4227c8b88b33SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, 42283647cd04SPaolo Bonzini fault->write, &fault->map_writable, 42293647cd04SPaolo Bonzini &fault->hva); 4230c50d8ae3SPaolo Bonzini if (!async) 42315276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4232c50d8ae3SPaolo Bonzini 42332839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 42343647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 42353647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 42361685c0f3SMingwei Zhang trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4237c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 42385276c616SSean Christopherson return RET_PF_RETRY; 42395276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 42405276c616SSean Christopherson return RET_PF_RETRY; 42415276c616SSean Christopherson } 4242c50d8ae3SPaolo Bonzini } 4243c50d8ae3SPaolo Bonzini 424476657687SPeter Xu /* 424576657687SPeter Xu * Allow gup to bail on pending non-fatal signals when it's also allowed 424676657687SPeter Xu * to wait for IO. Note, gup always bails if it is unable to quickly 424776657687SPeter Xu * get a page and a fatal signal, i.e. SIGKILL, is pending. 424876657687SPeter Xu */ 424976657687SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, 42503647cd04SPaolo Bonzini fault->write, &fault->map_writable, 42513647cd04SPaolo Bonzini &fault->hva); 42525276c616SSean Christopherson return RET_PF_CONTINUE; 4253c50d8ae3SPaolo Bonzini } 4254c50d8ae3SPaolo Bonzini 4255354c908cSDavid Matlack static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 4256354c908cSDavid Matlack unsigned int access) 4257ba6e3fe2SDavid Matlack { 425856c3a4e4SDavid Matlack int ret; 425956c3a4e4SDavid Matlack 4260ba6e3fe2SDavid Matlack fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4261ba6e3fe2SDavid Matlack smp_rmb(); 4262ba6e3fe2SDavid Matlack 426356c3a4e4SDavid Matlack ret = __kvm_faultin_pfn(vcpu, fault); 426456c3a4e4SDavid Matlack if (ret != RET_PF_CONTINUE) 426556c3a4e4SDavid Matlack return ret; 426656c3a4e4SDavid Matlack 426756c3a4e4SDavid Matlack if (unlikely(is_error_pfn(fault->pfn))) 4268cd08d178SDavid Matlack return kvm_handle_error_pfn(vcpu, fault); 426956c3a4e4SDavid Matlack 4270354c908cSDavid Matlack if (unlikely(!fault->slot)) 4271354c908cSDavid Matlack return kvm_handle_noslot_fault(vcpu, fault, access); 4272354c908cSDavid Matlack 427356c3a4e4SDavid Matlack return RET_PF_CONTINUE; 4274ba6e3fe2SDavid Matlack } 4275ba6e3fe2SDavid Matlack 4276a955cad8SSean Christopherson /* 4277a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4278a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4279a955cad8SSean Christopherson */ 4280a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4281ba6e3fe2SDavid Matlack struct kvm_page_fault *fault) 4282a955cad8SSean Christopherson { 4283b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 428418c841e1SSean Christopherson 428518c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 428618c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 428718c841e1SSean Christopherson return true; 428818c841e1SSean Christopherson 428918c841e1SSean Christopherson /* 429018c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 429118c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 429218c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 429318c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 429418c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 429518c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 429618c841e1SSean Christopherson */ 4297527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4298a955cad8SSean Christopherson return true; 4299a955cad8SSean Christopherson 4300a955cad8SSean Christopherson return fault->slot && 4301ba6e3fe2SDavid Matlack mmu_invalidate_retry_hva(vcpu->kvm, fault->mmu_seq, fault->hva); 4302a955cad8SSean Christopherson } 4303a955cad8SSean Christopherson 43044326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4305c50d8ae3SPaolo Bonzini { 430683f06fa7SSean Christopherson int r; 4307c50d8ae3SPaolo Bonzini 4308b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4309c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4310c50d8ae3SPaolo Bonzini 43113c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4312c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4313c4371c2aSSean Christopherson return r; 431483291445SSean Christopherson 4315378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4316c50d8ae3SPaolo Bonzini if (r) 4317c50d8ae3SPaolo Bonzini return r; 4318c50d8ae3SPaolo Bonzini 4319354c908cSDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 43205276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4321367fd790SSean Christopherson return r; 4322367fd790SSean Christopherson 4323367fd790SSean Christopherson r = RET_PF_RETRY; 4324531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4325a2855afcSBen Gardon 4326ba6e3fe2SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 4327367fd790SSean Christopherson goto out_unlock; 4328a955cad8SSean Christopherson 43297bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 43307bd7ded6SSean Christopherson if (r) 4331367fd790SSean Christopherson goto out_unlock; 4332bb18842eSBen Gardon 433343b74355SPaolo Bonzini r = __direct_map(vcpu, fault); 43340f90e1c1SSean Christopherson 4335367fd790SSean Christopherson out_unlock: 4336531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 43373647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4338367fd790SSean Christopherson return r; 4339c50d8ae3SPaolo Bonzini } 4340c50d8ae3SPaolo Bonzini 4341c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4342c501040aSPaolo Bonzini struct kvm_page_fault *fault) 43430f90e1c1SSean Christopherson { 43444326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 43450f90e1c1SSean Christopherson 43460f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 43474326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 43484326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 43490f90e1c1SSean Christopherson } 43500f90e1c1SSean Christopherson 4351c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4352c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4353c50d8ae3SPaolo Bonzini { 4354c50d8ae3SPaolo Bonzini int r = 1; 43559ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4356c50d8ae3SPaolo Bonzini 4357736c291cSSean Christopherson #ifndef CONFIG_X86_64 4358736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4359736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4360736c291cSSean Christopherson return -EFAULT; 4361736c291cSSean Christopherson #endif 4362736c291cSSean Christopherson 4363c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 43649ce372b3SVitaly Kuznetsov if (!flags) { 4365faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4366c50d8ae3SPaolo Bonzini 4367c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4368c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4369c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4370c50d8ae3SPaolo Bonzini insn_len); 43719ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 437268fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4373c50d8ae3SPaolo Bonzini local_irq_disable(); 43746bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4375c50d8ae3SPaolo Bonzini local_irq_enable(); 43769ce372b3SVitaly Kuznetsov } else { 43779ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4378c50d8ae3SPaolo Bonzini } 43799ce372b3SVitaly Kuznetsov 4380c50d8ae3SPaolo Bonzini return r; 4381c50d8ae3SPaolo Bonzini } 4382c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4383c50d8ae3SPaolo Bonzini 4384*9aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 4385*9aa8ab43SDavid Matlack static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, 4386*9aa8ab43SDavid Matlack struct kvm_page_fault *fault) 4387*9aa8ab43SDavid Matlack { 4388*9aa8ab43SDavid Matlack int r; 4389*9aa8ab43SDavid Matlack 4390*9aa8ab43SDavid Matlack if (page_fault_handle_page_track(vcpu, fault)) 4391*9aa8ab43SDavid Matlack return RET_PF_EMULATE; 4392*9aa8ab43SDavid Matlack 4393*9aa8ab43SDavid Matlack r = fast_page_fault(vcpu, fault); 4394*9aa8ab43SDavid Matlack if (r != RET_PF_INVALID) 4395*9aa8ab43SDavid Matlack return r; 4396*9aa8ab43SDavid Matlack 4397*9aa8ab43SDavid Matlack r = mmu_topup_memory_caches(vcpu, false); 4398*9aa8ab43SDavid Matlack if (r) 4399*9aa8ab43SDavid Matlack return r; 4400*9aa8ab43SDavid Matlack 4401*9aa8ab43SDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 4402*9aa8ab43SDavid Matlack if (r != RET_PF_CONTINUE) 4403*9aa8ab43SDavid Matlack return r; 4404*9aa8ab43SDavid Matlack 4405*9aa8ab43SDavid Matlack r = RET_PF_RETRY; 4406*9aa8ab43SDavid Matlack read_lock(&vcpu->kvm->mmu_lock); 4407*9aa8ab43SDavid Matlack 4408*9aa8ab43SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 4409*9aa8ab43SDavid Matlack goto out_unlock; 4410*9aa8ab43SDavid Matlack 4411*9aa8ab43SDavid Matlack r = make_mmu_pages_available(vcpu); 4412*9aa8ab43SDavid Matlack if (r) 4413*9aa8ab43SDavid Matlack goto out_unlock; 4414*9aa8ab43SDavid Matlack 4415*9aa8ab43SDavid Matlack r = kvm_tdp_mmu_map(vcpu, fault); 4416*9aa8ab43SDavid Matlack 4417*9aa8ab43SDavid Matlack out_unlock: 4418*9aa8ab43SDavid Matlack read_unlock(&vcpu->kvm->mmu_lock); 4419*9aa8ab43SDavid Matlack kvm_release_pfn_clean(fault->pfn); 4420*9aa8ab43SDavid Matlack return r; 4421*9aa8ab43SDavid Matlack } 4422*9aa8ab43SDavid Matlack #endif 4423*9aa8ab43SDavid Matlack 4424c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4425c50d8ae3SPaolo Bonzini { 4426d5e90a69SSean Christopherson /* 4427d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4428d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 4429d5e90a69SSean Christopherson * across the entire mapping. If the host MTRRs are ignored by TDP 4430d5e90a69SSean Christopherson * (shadow_memtype_mask is non-zero), and the VM has non-coherent DMA 4431d5e90a69SSean Christopherson * (DMA doesn't snoop CPU caches), KVM's ABI is to honor the memtype 4432d5e90a69SSean Christopherson * from the guest's MTRRs so that guest accesses to memory that is 4433d5e90a69SSean Christopherson * DMA'd aren't cached against the guest's wishes. 4434d5e90a69SSean Christopherson * 4435d5e90a69SSean Christopherson * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 4436d5e90a69SSean Christopherson * e.g. KVM will force UC memtype for host MMIO. 4437d5e90a69SSean Christopherson */ 4438d5e90a69SSean Christopherson if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) { 4439d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 44404326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 4441e5e6f8d2SDavid Matlack gfn_t base = fault->gfn & ~(page_num - 1); 4442c50d8ae3SPaolo Bonzini 4443cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4444cb9b88c6SSean Christopherson break; 4445d5e90a69SSean Christopherson } 4446c50d8ae3SPaolo Bonzini } 4447c50d8ae3SPaolo Bonzini 4448*9aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 4449*9aa8ab43SDavid Matlack if (tdp_mmu_enabled) 4450*9aa8ab43SDavid Matlack return kvm_tdp_mmu_page_fault(vcpu, fault); 4451*9aa8ab43SDavid Matlack #endif 4452*9aa8ab43SDavid Matlack 44534326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4454c50d8ae3SPaolo Bonzini } 4455c50d8ae3SPaolo Bonzini 445684a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4457c50d8ae3SPaolo Bonzini { 4458c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4459c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4460c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 44615efac074SPaolo Bonzini context->invlpg = NULL; 4462c50d8ae3SPaolo Bonzini } 4463c50d8ae3SPaolo Bonzini 4464be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 44650be44352SSean Christopherson union kvm_mmu_page_role role) 44660be44352SSean Christopherson { 4467be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 44685499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4469e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 44700be44352SSean Christopherson } 44710be44352SSean Christopherson 4472c50d8ae3SPaolo Bonzini /* 44735499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 44745499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 44755499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 44765499ea73SPaolo Bonzini * true is returned. 44775499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 44785499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4479c50d8ae3SPaolo Bonzini */ 44805499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 44815499ea73SPaolo Bonzini gpa_t new_pgd, 4482c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4483c50d8ae3SPaolo Bonzini { 4484c50d8ae3SPaolo Bonzini uint i; 4485c50d8ae3SPaolo Bonzini 4486b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 44870be44352SSean Christopherson return true; 44880be44352SSean Christopherson 4489c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 44905499ea73SPaolo Bonzini /* 44915499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 44925499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 44935499ea73SPaolo Bonzini * 0 C 1 2 3 44945499ea73SPaolo Bonzini * 1 C 0 2 3 44955499ea73SPaolo Bonzini * 2 C 0 1 3 44965499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 44975499ea73SPaolo Bonzini */ 4498b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4499b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 45005499ea73SPaolo Bonzini return true; 4501c50d8ae3SPaolo Bonzini } 4502c50d8ae3SPaolo Bonzini 45035499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 45045499ea73SPaolo Bonzini return false; 4505c50d8ae3SPaolo Bonzini } 4506c50d8ae3SPaolo Bonzini 4507c50d8ae3SPaolo Bonzini /* 45085499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 45095499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 45105499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 45115499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 45125499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 45135499ea73SPaolo Bonzini */ 45145499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 45155499ea73SPaolo Bonzini gpa_t new_pgd, 45165499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 45175499ea73SPaolo Bonzini { 45185499ea73SPaolo Bonzini uint i; 45195499ea73SPaolo Bonzini 45205499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 45215499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 45225499ea73SPaolo Bonzini goto hit; 45235499ea73SPaolo Bonzini 45245499ea73SPaolo Bonzini return false; 45255499ea73SPaolo Bonzini 45265499ea73SPaolo Bonzini hit: 45275499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 45285499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 45295499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 45305499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 45315499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 45325499ea73SPaolo Bonzini return true; 45335499ea73SPaolo Bonzini } 45345499ea73SPaolo Bonzini 45355499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 45365499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 45375499ea73SPaolo Bonzini { 45385499ea73SPaolo Bonzini /* 45395499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4540c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4541c50d8ae3SPaolo Bonzini * later if necessary. 4542c50d8ae3SPaolo Bonzini */ 45435499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 45445499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4545c50d8ae3SPaolo Bonzini 45465499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 45475499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 45485499ea73SPaolo Bonzini else 45495499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4550c50d8ae3SPaolo Bonzini } 4551c50d8ae3SPaolo Bonzini 4552d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4553c50d8ae3SPaolo Bonzini { 45540c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 45557a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 45560c1c92f1SPaolo Bonzini 45575499ea73SPaolo Bonzini if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) { 45585499ea73SPaolo Bonzini /* kvm_mmu_ensure_valid_pgd will set up a new root. */ 4559b869855bSSean Christopherson return; 4560c50d8ae3SPaolo Bonzini } 4561c50d8ae3SPaolo Bonzini 4562c50d8ae3SPaolo Bonzini /* 4563b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4564b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4565527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4566527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4567b869855bSSean Christopherson */ 4568b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4569b869855bSSean Christopherson 4570b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4571b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4572b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4573b5129100SSean Christopherson } 4574b869855bSSean Christopherson 4575b869855bSSean Christopherson /* 4576b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4577b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4578b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4579b869855bSSean Christopherson * the shadow page tables. 4580c50d8ae3SPaolo Bonzini */ 4581c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4582c50d8ae3SPaolo Bonzini 4583daa5b6c1SBen Gardon /* 4584daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4585daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4586daa5b6c1SBen Gardon */ 4587daa5b6c1SBen Gardon if (!new_role.direct) 4588daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4589b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4590c50d8ae3SPaolo Bonzini } 4591be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4592c50d8ae3SPaolo Bonzini 4593c50d8ae3SPaolo Bonzini static unsigned long get_cr3(struct kvm_vcpu *vcpu) 4594c50d8ae3SPaolo Bonzini { 4595c50d8ae3SPaolo Bonzini return kvm_read_cr3(vcpu); 4596c50d8ae3SPaolo Bonzini } 4597c50d8ae3SPaolo Bonzini 4598c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4599c3e5e415SLai Jiangshan unsigned int access) 4600c50d8ae3SPaolo Bonzini { 4601c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4602c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4603c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4604c50d8ae3SPaolo Bonzini return true; 4605c50d8ae3SPaolo Bonzini } 4606c50d8ae3SPaolo Bonzini 4607c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4608c50d8ae3SPaolo Bonzini return true; 4609c50d8ae3SPaolo Bonzini } 4610c50d8ae3SPaolo Bonzini 4611c50d8ae3SPaolo Bonzini return false; 4612c50d8ae3SPaolo Bonzini } 4613c50d8ae3SPaolo Bonzini 4614c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4615c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4616c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4617c50d8ae3SPaolo Bonzini #undef PTTYPE 4618c50d8ae3SPaolo Bonzini 4619c50d8ae3SPaolo Bonzini #define PTTYPE 64 4620c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4621c50d8ae3SPaolo Bonzini #undef PTTYPE 4622c50d8ae3SPaolo Bonzini 4623c50d8ae3SPaolo Bonzini #define PTTYPE 32 4624c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4625c50d8ae3SPaolo Bonzini #undef PTTYPE 4626c50d8ae3SPaolo Bonzini 4627c50d8ae3SPaolo Bonzini static void 4628b705a277SSean Christopherson __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 46295b7f575cSSean Christopherson u64 pa_bits_rsvd, int level, bool nx, bool gbpages, 4630c50d8ae3SPaolo Bonzini bool pse, bool amd) 4631c50d8ae3SPaolo Bonzini { 4632c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4633c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 46345b7f575cSSean Christopherson u64 high_bits_rsvd; 4635c50d8ae3SPaolo Bonzini 4636c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4637c50d8ae3SPaolo Bonzini 4638c50d8ae3SPaolo Bonzini if (!gbpages) 4639c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4640c50d8ae3SPaolo Bonzini 46415b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 46425b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 46435b7f575cSSean Christopherson else 46445b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 46455b7f575cSSean Christopherson 46465b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 46475b7f575cSSean Christopherson if (!nx) 46485b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 46495b7f575cSSean Christopherson 4650c50d8ae3SPaolo Bonzini /* 4651c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4652c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4653c50d8ae3SPaolo Bonzini */ 4654c50d8ae3SPaolo Bonzini if (amd) 4655c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4656c50d8ae3SPaolo Bonzini 4657c50d8ae3SPaolo Bonzini switch (level) { 4658c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4659c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4660c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4661c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4662c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4663c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4664c50d8ae3SPaolo Bonzini 4665c50d8ae3SPaolo Bonzini if (!pse) { 4666c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4667c50d8ae3SPaolo Bonzini break; 4668c50d8ae3SPaolo Bonzini } 4669c50d8ae3SPaolo Bonzini 4670c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4671c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4672c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4673c50d8ae3SPaolo Bonzini else 4674c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4675c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4676c50d8ae3SPaolo Bonzini break; 4677c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 46785b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 46795b7f575cSSean Christopherson high_bits_rsvd | 46805b7f575cSSean Christopherson rsvd_bits(5, 8) | 46815b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 46825b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 46835b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 46845b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4685c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4686c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4687c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4688c50d8ae3SPaolo Bonzini break; 4689c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 46905b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 46915b7f575cSSean Christopherson nonleaf_bit8_rsvd | 46925b7f575cSSean Christopherson rsvd_bits(7, 7); 4693c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4694c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4695df561f66SGustavo A. R. Silva fallthrough; 4696c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 46975b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 46985b7f575cSSean Christopherson nonleaf_bit8_rsvd | 46995b7f575cSSean Christopherson rsvd_bits(7, 7); 47005b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 47015b7f575cSSean Christopherson gbpages_bit_rsvd; 47025b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 47035b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4704c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4705c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 47065b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 47075b7f575cSSean Christopherson gbpages_bit_rsvd | 4708c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 47095b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4710c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4711c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4712c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4713c50d8ae3SPaolo Bonzini break; 4714c50d8ae3SPaolo Bonzini } 4715c50d8ae3SPaolo Bonzini } 4716c50d8ae3SPaolo Bonzini 471727de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 471827de9250SSean Christopherson { 471927de9250SSean Christopherson /* 472027de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 472127de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 472227de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 472327de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 472427de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 472527de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 472627de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 472727de9250SSean Christopherson */ 472827de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 472927de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 473027de9250SSean Christopherson } 473127de9250SSean Christopherson 4732c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4733c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4734c50d8ae3SPaolo Bonzini { 4735b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 47365b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 47374d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 473827de9250SSean Christopherson guest_can_use_gbpages(vcpu), 47394e9c0d80SSean Christopherson is_cr4_pse(context), 474023493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4741c50d8ae3SPaolo Bonzini } 4742c50d8ae3SPaolo Bonzini 4743c50d8ae3SPaolo Bonzini static void 4744c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 474584ea5c09SLai Jiangshan u64 pa_bits_rsvd, bool execonly, int huge_page_level) 4746c50d8ae3SPaolo Bonzini { 47475b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 474884ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4749c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4750c50d8ae3SPaolo Bonzini 475184ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 475284ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 475384ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 475484ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 475584ea5c09SLai Jiangshan 47565b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 47575b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 475884ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 475984ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 47605b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4761c50d8ae3SPaolo Bonzini 4762c50d8ae3SPaolo Bonzini /* large page */ 4763c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4764c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 476584ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 476684ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4767c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4768c50d8ae3SPaolo Bonzini 4769c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4770c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4771c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4772c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4773c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4774c50d8ae3SPaolo Bonzini if (!execonly) { 4775c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4776c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4777c50d8ae3SPaolo Bonzini } 4778c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4779c50d8ae3SPaolo Bonzini } 4780c50d8ae3SPaolo Bonzini 4781c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 478284ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4783c50d8ae3SPaolo Bonzini { 4784c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 478584ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 478684ea5c09SLai Jiangshan huge_page_level); 4787c50d8ae3SPaolo Bonzini } 4788c50d8ae3SPaolo Bonzini 47896f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 47906f8e65a6SSean Christopherson { 47916f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 47926f8e65a6SSean Christopherson } 47936f8e65a6SSean Christopherson 4794c50d8ae3SPaolo Bonzini /* 4795c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4796c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4797c50d8ae3SPaolo Bonzini * follow the features in guest. 4798c50d8ae3SPaolo Bonzini */ 479916be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 480016be1d12SSean Christopherson struct kvm_mmu *context) 4801c50d8ae3SPaolo Bonzini { 48028c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 48038c985b2dSSean Christopherson bool is_amd = true; 48048c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 48058c985b2dSSean Christopherson bool is_pse = false; 4806c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4807c50d8ae3SPaolo Bonzini int i; 4808c50d8ae3SPaolo Bonzini 4809a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 48108c985b2dSSean Christopherson 4811c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4812b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4813a972e29cSPaolo Bonzini context->root_role.level, 48147a458f0eSPaolo Bonzini context->root_role.efer_nx, 481527de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4816c50d8ae3SPaolo Bonzini 4817c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4818c50d8ae3SPaolo Bonzini return; 4819c50d8ae3SPaolo Bonzini 4820a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4821e54f1ff2SKai Huang /* 4822e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4823e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4824e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4825e54f1ff2SKai Huang * not allowed to be set. 4826e54f1ff2SKai Huang */ 4827e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4828e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4829e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4830e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4831c50d8ae3SPaolo Bonzini } 4832c50d8ae3SPaolo Bonzini 4833c50d8ae3SPaolo Bonzini } 4834c50d8ae3SPaolo Bonzini 4835c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4836c50d8ae3SPaolo Bonzini { 4837c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4838c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4839c50d8ae3SPaolo Bonzini } 4840c50d8ae3SPaolo Bonzini 4841c50d8ae3SPaolo Bonzini /* 4842c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4843c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4844c50d8ae3SPaolo Bonzini */ 4845c50d8ae3SPaolo Bonzini static void 4846e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4847c50d8ae3SPaolo Bonzini { 4848c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4849c50d8ae3SPaolo Bonzini int i; 4850c50d8ae3SPaolo Bonzini 4851c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4852c50d8ae3SPaolo Bonzini 4853c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4854b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 48556c6ab524SSean Christopherson context->root_role.level, true, 4856c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 48578c985b2dSSean Christopherson false, true); 4858c50d8ae3SPaolo Bonzini else 4859c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 486084ea5c09SLai Jiangshan reserved_hpa_bits(), false, 486184ea5c09SLai Jiangshan max_huge_page_level); 4862c50d8ae3SPaolo Bonzini 4863c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4864c50d8ae3SPaolo Bonzini return; 4865c50d8ae3SPaolo Bonzini 4866a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4867c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4868c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4869c50d8ae3SPaolo Bonzini } 4870c50d8ae3SPaolo Bonzini } 4871c50d8ae3SPaolo Bonzini 4872c50d8ae3SPaolo Bonzini /* 4873c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4874c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4875c50d8ae3SPaolo Bonzini */ 4876c50d8ae3SPaolo Bonzini static void 4877e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4878c50d8ae3SPaolo Bonzini { 4879c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 488084ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 488184ea5c09SLai Jiangshan max_huge_page_level); 4882c50d8ae3SPaolo Bonzini } 4883c50d8ae3SPaolo Bonzini 4884c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4885c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4886c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4887c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4888c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4889c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4890c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4891c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4892c50d8ae3SPaolo Bonzini 4893c50d8ae3SPaolo Bonzini 4894c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4895c50d8ae3SPaolo Bonzini { 4896c50d8ae3SPaolo Bonzini unsigned byte; 4897c50d8ae3SPaolo Bonzini 4898c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4899c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4900c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4901c50d8ae3SPaolo Bonzini 4902c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4903c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4904c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 490590599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4906c50d8ae3SPaolo Bonzini 4907c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4908c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4909c50d8ae3SPaolo Bonzini 4910c50d8ae3SPaolo Bonzini /* 4911c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4912c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4913c50d8ae3SPaolo Bonzini */ 4914c50d8ae3SPaolo Bonzini 4915c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4916c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4917c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4918c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4919c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4920c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4921c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4922c50d8ae3SPaolo Bonzini u8 smepf = 0; 4923c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4924c50d8ae3SPaolo Bonzini u8 smapf = 0; 4925c50d8ae3SPaolo Bonzini 4926c50d8ae3SPaolo Bonzini if (!ept) { 4927c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4928c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4929c50d8ae3SPaolo Bonzini 4930c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 493190599c28SSean Christopherson if (!efer_nx) 4932c50d8ae3SPaolo Bonzini ff = 0; 4933c50d8ae3SPaolo Bonzini 4934c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4935c50d8ae3SPaolo Bonzini if (!cr0_wp) 4936c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4937c50d8ae3SPaolo Bonzini 4938c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4939c50d8ae3SPaolo Bonzini if (cr4_smep) 4940c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4941c50d8ae3SPaolo Bonzini 4942c50d8ae3SPaolo Bonzini /* 4943c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4944c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4945c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4946c50d8ae3SPaolo Bonzini * conditions are true: 4947c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4948c50d8ae3SPaolo Bonzini * - A user page is accessed 4949c50d8ae3SPaolo Bonzini * - The access is not a fetch 49504f4aa80eSLai Jiangshan * - The access is supervisor mode 49514f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4952c50d8ae3SPaolo Bonzini * 495394b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 495494b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 4955c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 4956c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 4957c50d8ae3SPaolo Bonzini */ 4958c50d8ae3SPaolo Bonzini if (cr4_smap) 4959c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 4960c50d8ae3SPaolo Bonzini } 4961c50d8ae3SPaolo Bonzini 4962c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 4963c50d8ae3SPaolo Bonzini } 4964c50d8ae3SPaolo Bonzini } 4965c50d8ae3SPaolo Bonzini 4966c50d8ae3SPaolo Bonzini /* 4967c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 4968c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 4969c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 4970c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 4971c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 4972c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 4973c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 4974c50d8ae3SPaolo Bonzini * 4975c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 4976c50d8ae3SPaolo Bonzini * page tables and the machine state: 4977c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 4978c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 4979c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 4980c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 4981c50d8ae3SPaolo Bonzini * 4982c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 4983c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 4984c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 4985c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 4986c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 4987c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 4988c50d8ae3SPaolo Bonzini * only will be masked away. 4989c50d8ae3SPaolo Bonzini */ 49902e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 4991c50d8ae3SPaolo Bonzini { 4992c50d8ae3SPaolo Bonzini unsigned bit; 4993c50d8ae3SPaolo Bonzini bool wp; 4994c50d8ae3SPaolo Bonzini 4995c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 4996a3ca5281SChenyi Qiang 4997a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 4998c50d8ae3SPaolo Bonzini return; 4999c50d8ae3SPaolo Bonzini 50002e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 5001c50d8ae3SPaolo Bonzini 5002c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 5003c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 5004c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 5005c50d8ae3SPaolo Bonzini 5006c50d8ae3SPaolo Bonzini pfec = bit << 1; 5007c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 5008c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 5009c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 5010c50d8ae3SPaolo Bonzini 5011c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 5012c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 5013c50d8ae3SPaolo Bonzini 5014c50d8ae3SPaolo Bonzini /* 5015c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 5016c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 5017c50d8ae3SPaolo Bonzini */ 5018c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 5019c50d8ae3SPaolo Bonzini /* 5020c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 5021c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 5022c50d8ae3SPaolo Bonzini */ 5023c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 5024c50d8ae3SPaolo Bonzini 5025c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 5026c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 5027c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 5028c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 5029c50d8ae3SPaolo Bonzini 5030c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 5031c50d8ae3SPaolo Bonzini } 5032c50d8ae3SPaolo Bonzini } 5033c50d8ae3SPaolo Bonzini 5034533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 5035533f9a4bSSean Christopherson struct kvm_mmu *mmu) 5036c50d8ae3SPaolo Bonzini { 5037533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 5038533f9a4bSSean Christopherson return; 5039c50d8ae3SPaolo Bonzini 5040c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 5041533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 5042533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 5043c50d8ae3SPaolo Bonzini } 5044c50d8ae3SPaolo Bonzini 5045fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 5046c50d8ae3SPaolo Bonzini { 5047c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 5048c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5049c50d8ae3SPaolo Bonzini context->sync_page = paging64_sync_page; 5050c50d8ae3SPaolo Bonzini context->invlpg = paging64_invlpg; 5051c50d8ae3SPaolo Bonzini } 5052c50d8ae3SPaolo Bonzini 505384a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 5054c50d8ae3SPaolo Bonzini { 5055c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 5056c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5057c50d8ae3SPaolo Bonzini context->sync_page = paging32_sync_page; 5058c50d8ae3SPaolo Bonzini context->invlpg = paging32_invlpg; 5059c50d8ae3SPaolo Bonzini } 5060c50d8ae3SPaolo Bonzini 50617a7ae829SPaolo Bonzini static union kvm_cpu_role 5062e5ed0fb0SPaolo Bonzini kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs) 5063e5ed0fb0SPaolo Bonzini { 50647a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5065e5ed0fb0SPaolo Bonzini 5066e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 5067e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 5068e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 5069e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 5070e5ed0fb0SPaolo Bonzini 5071e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 5072e5ed0fb0SPaolo Bonzini role.base.direct = 1; 5073e5ed0fb0SPaolo Bonzini return role; 5074e5ed0fb0SPaolo Bonzini } 5075e5ed0fb0SPaolo Bonzini 5076e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 5077e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 5078e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 5079e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 5080e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 508160f3cb60SPaolo Bonzini 508260f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 508360f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 508460f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 508560f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 508660f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 508760f3cb60SPaolo Bonzini else 508860f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 5089e5ed0fb0SPaolo Bonzini 5090e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 5091e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 5092e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 5093e5ed0fb0SPaolo Bonzini 5094e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 5095e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 5096e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 5097e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 5098e5ed0fb0SPaolo Bonzini return role; 5099e5ed0fb0SPaolo Bonzini } 5100e5ed0fb0SPaolo Bonzini 5101d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 5102d468d94bSSean Christopherson { 5103746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5104746700d2SWei Huang if (tdp_root_level) 5105746700d2SWei Huang return tdp_root_level; 5106746700d2SWei Huang 5107d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 510883013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5109d468d94bSSean Christopherson return 4; 5110d468d94bSSean Christopherson 511183013059SSean Christopherson return max_tdp_level; 5112d468d94bSSean Christopherson } 5113d468d94bSSean Christopherson 51147a458f0eSPaolo Bonzini static union kvm_mmu_page_role 51158626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 51167a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5117c50d8ae3SPaolo Bonzini { 51187a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5119c50d8ae3SPaolo Bonzini 51207a458f0eSPaolo Bonzini role.access = ACC_ALL; 51217a458f0eSPaolo Bonzini role.cr0_wp = true; 51227a458f0eSPaolo Bonzini role.efer_nx = true; 51237a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 51247a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 512554275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 51267a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 51277a458f0eSPaolo Bonzini role.direct = true; 51287a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5129c50d8ae3SPaolo Bonzini 5130c50d8ae3SPaolo Bonzini return role; 5131c50d8ae3SPaolo Bonzini } 5132c50d8ae3SPaolo Bonzini 513339e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5134a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5135c50d8ae3SPaolo Bonzini { 51368c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 51377a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5138c50d8ae3SPaolo Bonzini 5139e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 51407a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5141c50d8ae3SPaolo Bonzini return; 5142c50d8ae3SPaolo Bonzini 5143e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 51447a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 51457a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5146c50d8ae3SPaolo Bonzini context->sync_page = nonpaging_sync_page; 51475efac074SPaolo Bonzini context->invlpg = NULL; 5148d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5149c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5150c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5151c50d8ae3SPaolo Bonzini 515236f26787SSean Christopherson if (!is_cr0_pg(context)) 5153c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 515436f26787SSean Christopherson else if (is_cr4_pae(context)) 5155c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5156f4bd6f73SSean Christopherson else 5157c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5158c50d8ae3SPaolo Bonzini 5159533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5160e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5161c50d8ae3SPaolo Bonzini } 5162c50d8ae3SPaolo Bonzini 51638c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 51647a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 51657a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5166c50d8ae3SPaolo Bonzini { 5167e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 51687a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 516918db1b17SSean Christopherson return; 5170c50d8ae3SPaolo Bonzini 5171e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 51727a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 517318db1b17SSean Christopherson 517436f26787SSean Christopherson if (!is_cr0_pg(context)) 517584a16226SSean Christopherson nonpaging_init_context(context); 517636f26787SSean Christopherson else if (is_cr4_pae(context)) 5177fe660f72SSean Christopherson paging64_init_context(context); 5178c50d8ae3SPaolo Bonzini else 517984a16226SSean Christopherson paging32_init_context(context); 5180c50d8ae3SPaolo Bonzini 5181533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5182c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5183c50d8ae3SPaolo Bonzini } 51840f04a2acSVitaly Kuznetsov 5185594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5186a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 51870f04a2acSVitaly Kuznetsov { 51888c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 518956b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 519056b321f9SPaolo Bonzini 519156b321f9SPaolo Bonzini root_role = cpu_role.base; 519256b321f9SPaolo Bonzini 519356b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 519456b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 519556b321f9SPaolo Bonzini 519656b321f9SPaolo Bonzini /* 519756b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 519856b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 519956b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 520056b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 520156b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 520256b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 520356b321f9SPaolo Bonzini * MMU contexts. 520456b321f9SPaolo Bonzini */ 520556b321f9SPaolo Bonzini root_role.efer_nx = true; 52060f04a2acSVitaly Kuznetsov 52077a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 52080f04a2acSVitaly Kuznetsov } 52090f04a2acSVitaly Kuznetsov 5210dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5211dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 52120f04a2acSVitaly Kuznetsov { 52138c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5214594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5215594e91a1SSean Christopherson .cr0 = cr0, 521628f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5217594e91a1SSean Christopherson .efer = efer, 5218594e91a1SSean Christopherson }; 52197a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 522056b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 522156b321f9SPaolo Bonzini 522256b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 522356b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 522456b321f9SPaolo Bonzini 522556b321f9SPaolo Bonzini root_role = cpu_role.base; 522656b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 522784e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 522884e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 522984e5ffd0SLai Jiangshan root_role.passthrough = 1; 52300f04a2acSVitaly Kuznetsov 52317a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5232d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 52330f04a2acSVitaly Kuznetsov } 52340f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5235c50d8ae3SPaolo Bonzini 52367a7ae829SPaolo Bonzini static union kvm_cpu_role 5237c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5238bb1fcc70SSean Christopherson bool execonly, u8 level) 5239c50d8ae3SPaolo Bonzini { 52407a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5241c50d8ae3SPaolo Bonzini 5242daed87b8SPaolo Bonzini /* 5243daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5244daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5245daed87b8SPaolo Bonzini */ 5246daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5247bb1fcc70SSean Christopherson role.base.level = level; 5248bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5249c50d8ae3SPaolo Bonzini role.base.direct = false; 5250c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5251c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5252c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5253c50d8ae3SPaolo Bonzini 5254cd6767c3SSean Christopherson role.ext.word = 0; 5255c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5256cd6767c3SSean Christopherson role.ext.valid = 1; 5257c50d8ae3SPaolo Bonzini 5258c50d8ae3SPaolo Bonzini return role; 5259c50d8ae3SPaolo Bonzini } 5260c50d8ae3SPaolo Bonzini 5261c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5262cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5263cc022ae1SLai Jiangshan gpa_t new_eptp) 5264c50d8ae3SPaolo Bonzini { 52658c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5266bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 52677a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5268c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5269bb1fcc70SSean Christopherson execonly, level); 5270c50d8ae3SPaolo Bonzini 5271e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5272e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5273e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 52747a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 527518db1b17SSean Christopherson 5276c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5277c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5278c50d8ae3SPaolo Bonzini context->sync_page = ept_sync_page; 5279c50d8ae3SPaolo Bonzini context->invlpg = ept_invlpg; 5280347a0d0dSPaolo Bonzini 5281c596f147SSean Christopherson update_permission_bitmask(context, true); 528228f091bcSPaolo Bonzini context->pkru_mask = 0; 5283cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5284e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5285c50d8ae3SPaolo Bonzini } 52863cffc89dSPaolo Bonzini 5287d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 52883cffc89dSPaolo Bonzini } 5289c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5290c50d8ae3SPaolo Bonzini 529139e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5292a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5293c50d8ae3SPaolo Bonzini { 52948c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5295c50d8ae3SPaolo Bonzini 5296a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5297929d1cfaSPaolo Bonzini 5298d8dd54e0SSean Christopherson context->get_guest_pgd = get_cr3; 5299c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5300c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5301c50d8ae3SPaolo Bonzini } 5302c50d8ae3SPaolo Bonzini 530339e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5304a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5305c50d8ae3SPaolo Bonzini { 5306c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5307c50d8ae3SPaolo Bonzini 5308e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5309c50d8ae3SPaolo Bonzini return; 5310c50d8ae3SPaolo Bonzini 5311e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5312d8dd54e0SSean Christopherson g_context->get_guest_pgd = get_cr3; 5313c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5314c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5315c50d8ae3SPaolo Bonzini 5316c50d8ae3SPaolo Bonzini /* 53175efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 53185efac074SPaolo Bonzini * SPTEs. 53195efac074SPaolo Bonzini */ 53205efac074SPaolo Bonzini g_context->invlpg = NULL; 53215efac074SPaolo Bonzini 53225efac074SPaolo Bonzini /* 5323c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5324c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5325c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5326c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5327c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5328c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5329c50d8ae3SPaolo Bonzini */ 5330fa4b5588SSean Christopherson if (!is_paging(vcpu)) 53311f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5332fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 53331f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5334fa4b5588SSean Christopherson else if (is_pae(vcpu)) 53351f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5336fa4b5588SSean Christopherson else 53371f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5338fa4b5588SSean Christopherson 5339533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5340c50d8ae3SPaolo Bonzini } 5341c50d8ae3SPaolo Bonzini 5342c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5343c50d8ae3SPaolo Bonzini { 534439e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5345a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 534639e7e2bfSPaolo Bonzini 5347c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5348a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5349c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5350a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5351c50d8ae3SPaolo Bonzini else 5352a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5353c50d8ae3SPaolo Bonzini } 5354c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5355c50d8ae3SPaolo Bonzini 535649c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 535749c6f875SSean Christopherson { 535849c6f875SSean Christopherson /* 535949c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 536049c6f875SSean Christopherson * information is factored into reserved bit calculations. 5361feb627e8SVitaly Kuznetsov * 5362feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5363feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5364feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5365feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5366feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5367feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5368feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 536949c6f875SSean Christopherson */ 53707a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 53717a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 53727a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5373e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5374e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5375e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 537649c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 537763f5a190SSean Christopherson 537863f5a190SSean Christopherson /* 5379feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5380feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 538163f5a190SSean Christopherson */ 5382feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 538349c6f875SSean Christopherson } 538449c6f875SSean Christopherson 5385c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5386c50d8ae3SPaolo Bonzini { 5387c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5388c9060662SSean Christopherson kvm_init_mmu(vcpu); 5389c50d8ae3SPaolo Bonzini } 5390c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5391c50d8ae3SPaolo Bonzini 5392c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5393c50d8ae3SPaolo Bonzini { 5394c50d8ae3SPaolo Bonzini int r; 5395c50d8ae3SPaolo Bonzini 5396347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5397c50d8ae3SPaolo Bonzini if (r) 5398c50d8ae3SPaolo Bonzini goto out; 5399748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5400c50d8ae3SPaolo Bonzini if (r) 5401c50d8ae3SPaolo Bonzini goto out; 5402347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 54036e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 54046e6ec584SSean Christopherson else 54056e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5406c50d8ae3SPaolo Bonzini if (r) 5407c50d8ae3SPaolo Bonzini goto out; 5408a91f387bSSean Christopherson 5409a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5410a91f387bSSean Christopherson 5411727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5412db01416bSSean Christopherson 5413db01416bSSean Christopherson /* 5414db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5415db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5416db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5417db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5418db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5419db01416bSSean Christopherson */ 5420e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5421c50d8ae3SPaolo Bonzini out: 5422c50d8ae3SPaolo Bonzini return r; 5423c50d8ae3SPaolo Bonzini } 5424c50d8ae3SPaolo Bonzini 5425c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5426c50d8ae3SPaolo Bonzini { 54270c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 54280c1c92f1SPaolo Bonzini 54290c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5430b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 54310c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5432b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 54336d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5434c50d8ae3SPaolo Bonzini } 5435c50d8ae3SPaolo Bonzini 5436527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5437527d5cd7SSean Christopherson { 5438527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5439527d5cd7SSean Christopherson 5440527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5441527d5cd7SSean Christopherson return false; 5442527d5cd7SSean Christopherson 5443527d5cd7SSean Christopherson /* 5444527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5445527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5446527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5447527d5cd7SSean Christopherson * such false positives are relatively rare: 5448527d5cd7SSean Christopherson * 5449527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5450527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5451527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5452527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5453527d5cd7SSean Christopherson */ 5454527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5455527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5456527d5cd7SSean Christopherson } 5457527d5cd7SSean Christopherson 5458527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5459527d5cd7SSean Christopherson { 5460527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5461527d5cd7SSean Christopherson int i; 5462527d5cd7SSean Christopherson 5463527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5464527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5465527d5cd7SSean Christopherson 5466527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5467cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5468527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5469527d5cd7SSean Christopherson } 5470527d5cd7SSean Christopherson 5471527d5cd7SSean Christopherson if (roots_to_free) 5472527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5473527d5cd7SSean Christopherson } 5474527d5cd7SSean Christopherson 5475527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5476527d5cd7SSean Christopherson { 5477527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5478527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5479527d5cd7SSean Christopherson } 5480527d5cd7SSean Christopherson 5481c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5482c50d8ae3SPaolo Bonzini int *bytes) 5483c50d8ae3SPaolo Bonzini { 5484c50d8ae3SPaolo Bonzini u64 gentry = 0; 5485c50d8ae3SPaolo Bonzini int r; 5486c50d8ae3SPaolo Bonzini 5487c50d8ae3SPaolo Bonzini /* 5488c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5489c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5490c50d8ae3SPaolo Bonzini * when they have the same mode. 5491c50d8ae3SPaolo Bonzini */ 5492c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5493c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5494c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5495c50d8ae3SPaolo Bonzini *bytes = 8; 5496c50d8ae3SPaolo Bonzini } 5497c50d8ae3SPaolo Bonzini 5498c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5499c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5500c50d8ae3SPaolo Bonzini if (r) 5501c50d8ae3SPaolo Bonzini gentry = 0; 5502c50d8ae3SPaolo Bonzini } 5503c50d8ae3SPaolo Bonzini 5504c50d8ae3SPaolo Bonzini return gentry; 5505c50d8ae3SPaolo Bonzini } 5506c50d8ae3SPaolo Bonzini 5507c50d8ae3SPaolo Bonzini /* 5508c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5509c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5510c50d8ae3SPaolo Bonzini */ 5511c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5512c50d8ae3SPaolo Bonzini { 5513c50d8ae3SPaolo Bonzini /* 5514c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5515c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5516c50d8ae3SPaolo Bonzini */ 55173bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5518c50d8ae3SPaolo Bonzini return false; 5519c50d8ae3SPaolo Bonzini 5520c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5521c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5522c50d8ae3SPaolo Bonzini } 5523c50d8ae3SPaolo Bonzini 5524c50d8ae3SPaolo Bonzini /* 5525c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5526c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5527c50d8ae3SPaolo Bonzini */ 5528c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5529c50d8ae3SPaolo Bonzini int bytes) 5530c50d8ae3SPaolo Bonzini { 5531c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5532c50d8ae3SPaolo Bonzini 5533c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5534c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5535c50d8ae3SPaolo Bonzini 5536c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5537bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5538c50d8ae3SPaolo Bonzini 5539c50d8ae3SPaolo Bonzini /* 5540c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5541c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5542c50d8ae3SPaolo Bonzini */ 5543c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5544c50d8ae3SPaolo Bonzini return false; 5545c50d8ae3SPaolo Bonzini 5546c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5547c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5548c50d8ae3SPaolo Bonzini 5549c50d8ae3SPaolo Bonzini return misaligned; 5550c50d8ae3SPaolo Bonzini } 5551c50d8ae3SPaolo Bonzini 5552c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5553c50d8ae3SPaolo Bonzini { 5554c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5555c50d8ae3SPaolo Bonzini u64 *spte; 5556c50d8ae3SPaolo Bonzini int level; 5557c50d8ae3SPaolo Bonzini 5558c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5559c50d8ae3SPaolo Bonzini level = sp->role.level; 5560c50d8ae3SPaolo Bonzini *nspte = 1; 5561bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5562c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5563c50d8ae3SPaolo Bonzini /* 5564c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5565c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5566c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5567c50d8ae3SPaolo Bonzini */ 5568c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5569c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5570c50d8ae3SPaolo Bonzini page_offset <<= 1; 5571c50d8ae3SPaolo Bonzini *nspte = 2; 5572c50d8ae3SPaolo Bonzini } 5573c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5574c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5575c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5576c50d8ae3SPaolo Bonzini return NULL; 5577c50d8ae3SPaolo Bonzini } 5578c50d8ae3SPaolo Bonzini 5579c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5580c50d8ae3SPaolo Bonzini return spte; 5581c50d8ae3SPaolo Bonzini } 5582c50d8ae3SPaolo Bonzini 5583c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5584c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5585c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5586c50d8ae3SPaolo Bonzini { 5587c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5588c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5589c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5590c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5591c50d8ae3SPaolo Bonzini int npte; 559206152b2dSLai Jiangshan bool flush = false; 5593c50d8ae3SPaolo Bonzini 5594c50d8ae3SPaolo Bonzini /* 5595c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5596c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5597c50d8ae3SPaolo Bonzini */ 5598c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5599c50d8ae3SPaolo Bonzini return; 5600c50d8ae3SPaolo Bonzini 5601c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5602c50d8ae3SPaolo Bonzini 5603531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5604c50d8ae3SPaolo Bonzini 5605c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5606c50d8ae3SPaolo Bonzini 5607c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5608c50d8ae3SPaolo Bonzini 5609767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5610c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5611c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5612c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5613c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5614c50d8ae3SPaolo Bonzini continue; 5615c50d8ae3SPaolo Bonzini } 5616c50d8ae3SPaolo Bonzini 5617c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5618c50d8ae3SPaolo Bonzini if (!spte) 5619c50d8ae3SPaolo Bonzini continue; 5620c50d8ae3SPaolo Bonzini 5621c50d8ae3SPaolo Bonzini while (npte--) { 5622c50d8ae3SPaolo Bonzini entry = *spte; 56232de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5624c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5625c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 56261441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 562706152b2dSLai Jiangshan flush = true; 5628c50d8ae3SPaolo Bonzini ++spte; 5629c50d8ae3SPaolo Bonzini } 5630c50d8ae3SPaolo Bonzini } 563106152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5632531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5633c50d8ae3SPaolo Bonzini } 5634c50d8ae3SPaolo Bonzini 56351075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5636c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5637c50d8ae3SPaolo Bonzini { 563892daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5639347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5640c50d8ae3SPaolo Bonzini 5641b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5642ddce6208SSean Christopherson return RET_PF_RETRY; 5643ddce6208SSean Christopherson 5644c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5645c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5646736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5647c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5648c50d8ae3SPaolo Bonzini goto emulate; 5649c50d8ae3SPaolo Bonzini } 5650c50d8ae3SPaolo Bonzini 5651c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 56527a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 56537a02674dSSean Christopherson lower_32_bits(error_code), false); 565419025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 56557b367bc9SSean Christopherson return -EIO; 5656c50d8ae3SPaolo Bonzini } 5657c50d8ae3SPaolo Bonzini 5658c50d8ae3SPaolo Bonzini if (r < 0) 5659c50d8ae3SPaolo Bonzini return r; 566083a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 566183a2ba4cSSean Christopherson return 1; 5662c50d8ae3SPaolo Bonzini 5663c50d8ae3SPaolo Bonzini /* 5664c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5665c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5666c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5667c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5668c50d8ae3SPaolo Bonzini * and resume the guest. 5669c50d8ae3SPaolo Bonzini */ 5670347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5671c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5672736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5673c50d8ae3SPaolo Bonzini return 1; 5674c50d8ae3SPaolo Bonzini } 5675c50d8ae3SPaolo Bonzini 5676c50d8ae3SPaolo Bonzini /* 5677c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5678c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5679c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5680c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5681c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5682c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5683c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5684c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5685c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5686c50d8ae3SPaolo Bonzini */ 5687736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 568892daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5689c50d8ae3SPaolo Bonzini emulate: 5690736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5691c50d8ae3SPaolo Bonzini insn_len); 5692c50d8ae3SPaolo Bonzini } 5693c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5694c50d8ae3SPaolo Bonzini 56955efac074SPaolo Bonzini void kvm_mmu_invalidate_gva(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 56965efac074SPaolo Bonzini gva_t gva, hpa_t root_hpa) 5697c50d8ae3SPaolo Bonzini { 5698c50d8ae3SPaolo Bonzini int i; 5699c50d8ae3SPaolo Bonzini 57005efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 57015efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 57025efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5703c50d8ae3SPaolo Bonzini if (is_noncanonical_address(gva, vcpu)) 5704c50d8ae3SPaolo Bonzini return; 5705c50d8ae3SPaolo Bonzini 5706e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 57075efac074SPaolo Bonzini } 57085efac074SPaolo Bonzini 57095efac074SPaolo Bonzini if (!mmu->invlpg) 57105efac074SPaolo Bonzini return; 57115efac074SPaolo Bonzini 57125efac074SPaolo Bonzini if (root_hpa == INVALID_PAGE) { 5713b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5714c50d8ae3SPaolo Bonzini 5715c50d8ae3SPaolo Bonzini /* 5716c50d8ae3SPaolo Bonzini * INVLPG is required to invalidate any global mappings for the VA, 5717c50d8ae3SPaolo Bonzini * irrespective of PCID. Since it would take us roughly similar amount 5718c50d8ae3SPaolo Bonzini * of work to determine whether any of the prev_root mappings of the VA 5719c50d8ae3SPaolo Bonzini * is marked global, or to just sync it blindly, so we might as well 5720c50d8ae3SPaolo Bonzini * just always sync it. 5721c50d8ae3SPaolo Bonzini * 5722c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5723c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5724c50d8ae3SPaolo Bonzini * for them. 5725c50d8ae3SPaolo Bonzini */ 5726c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 5727c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa)) 5728c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 57295efac074SPaolo Bonzini } else { 57305efac074SPaolo Bonzini mmu->invlpg(vcpu, gva, root_hpa); 57315efac074SPaolo Bonzini } 57325efac074SPaolo Bonzini } 5733c50d8ae3SPaolo Bonzini 57345efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 57355efac074SPaolo Bonzini { 573605b29633SLai Jiangshan kvm_mmu_invalidate_gva(vcpu, vcpu->arch.walk_mmu, gva, INVALID_PAGE); 5737c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5738c50d8ae3SPaolo Bonzini } 5739c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5740c50d8ae3SPaolo Bonzini 57415efac074SPaolo Bonzini 5742c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5743c50d8ae3SPaolo Bonzini { 5744c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 5745c50d8ae3SPaolo Bonzini bool tlb_flush = false; 5746c50d8ae3SPaolo Bonzini uint i; 5747c50d8ae3SPaolo Bonzini 5748c50d8ae3SPaolo Bonzini if (pcid == kvm_get_active_pcid(vcpu)) { 57499f46c187SPaolo Bonzini if (mmu->invlpg) 5750b9e5603cSPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->root.hpa); 5751c50d8ae3SPaolo Bonzini tlb_flush = true; 5752c50d8ae3SPaolo Bonzini } 5753c50d8ae3SPaolo Bonzini 5754c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5755c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 5756be01e8e2SSean Christopherson pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) { 57579f46c187SPaolo Bonzini if (mmu->invlpg) 5758c50d8ae3SPaolo Bonzini mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); 5759c50d8ae3SPaolo Bonzini tlb_flush = true; 5760c50d8ae3SPaolo Bonzini } 5761c50d8ae3SPaolo Bonzini } 5762c50d8ae3SPaolo Bonzini 5763c50d8ae3SPaolo Bonzini if (tlb_flush) 5764e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_gva)(vcpu, gva); 5765c50d8ae3SPaolo Bonzini 5766c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5767c50d8ae3SPaolo Bonzini 5768c50d8ae3SPaolo Bonzini /* 5769c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5770c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5771c50d8ae3SPaolo Bonzini * for them. 5772c50d8ae3SPaolo Bonzini */ 5773c50d8ae3SPaolo Bonzini } 5774c50d8ae3SPaolo Bonzini 5775746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5776746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5777c50d8ae3SPaolo Bonzini { 5778bde77235SSean Christopherson tdp_enabled = enable_tdp; 5779746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 578083013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5781703c335dSSean Christopherson 57821f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 57831f98f2bdSDavid Matlack tdp_mmu_enabled = tdp_mmu_allowed && tdp_enabled; 57841f98f2bdSDavid Matlack #endif 5785703c335dSSean Christopherson /* 57861d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5787703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5788703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5789703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5790703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5791703c335dSSean Christopherson */ 5792703c335dSSean Christopherson if (tdp_enabled) 57931d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5794703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 57951d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5796703c335dSSean Christopherson else 57971d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5798c50d8ae3SPaolo Bonzini } 5799bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5800c50d8ae3SPaolo Bonzini 5801c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5802269e9552SHamza Mahfooz typedef bool (*slot_level_handler) (struct kvm *kvm, 5803269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5804269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5805c50d8ae3SPaolo Bonzini 5806c50d8ae3SPaolo Bonzini /* The caller should hold mmu-lock before calling this function. */ 5807c50d8ae3SPaolo Bonzini static __always_inline bool 5808269e9552SHamza Mahfooz slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5809c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 58101a61b7dbSSean Christopherson gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, 58111a61b7dbSSean Christopherson bool flush) 5812c50d8ae3SPaolo Bonzini { 5813c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5814c50d8ae3SPaolo Bonzini 5815c50d8ae3SPaolo Bonzini for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, 5816c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5817c50d8ae3SPaolo Bonzini if (iterator.rmap) 58180a234f5dSSean Christopherson flush |= fn(kvm, iterator.rmap, memslot); 5819c50d8ae3SPaolo Bonzini 5820531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5821302695a5SSean Christopherson if (flush && flush_on_yield) { 5822c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, 5823c50d8ae3SPaolo Bonzini start_gfn, 5824c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5825c50d8ae3SPaolo Bonzini flush = false; 5826c50d8ae3SPaolo Bonzini } 5827531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5828c50d8ae3SPaolo Bonzini } 5829c50d8ae3SPaolo Bonzini } 5830c50d8ae3SPaolo Bonzini 5831c50d8ae3SPaolo Bonzini return flush; 5832c50d8ae3SPaolo Bonzini } 5833c50d8ae3SPaolo Bonzini 5834c50d8ae3SPaolo Bonzini static __always_inline bool 5835269e9552SHamza Mahfooz slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5836c50d8ae3SPaolo Bonzini slot_level_handler fn, int start_level, int end_level, 5837302695a5SSean Christopherson bool flush_on_yield) 5838c50d8ae3SPaolo Bonzini { 5839c50d8ae3SPaolo Bonzini return slot_handle_level_range(kvm, memslot, fn, start_level, 5840c50d8ae3SPaolo Bonzini end_level, memslot->base_gfn, 5841c50d8ae3SPaolo Bonzini memslot->base_gfn + memslot->npages - 1, 58421a61b7dbSSean Christopherson flush_on_yield, false); 5843c50d8ae3SPaolo Bonzini } 5844c50d8ae3SPaolo Bonzini 5845c50d8ae3SPaolo Bonzini static __always_inline bool 5846610265eaSDavid Matlack slot_handle_level_4k(struct kvm *kvm, const struct kvm_memory_slot *memslot, 5847302695a5SSean Christopherson slot_level_handler fn, bool flush_on_yield) 5848c50d8ae3SPaolo Bonzini { 58493bae0459SSean Christopherson return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, 5850302695a5SSean Christopherson PG_LEVEL_4K, flush_on_yield); 5851c50d8ae3SPaolo Bonzini } 5852c50d8ae3SPaolo Bonzini 5853c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5854c50d8ae3SPaolo Bonzini { 58554a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 58564a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5857c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 585803ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5859cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5860c50d8ae3SPaolo Bonzini } 5861c50d8ae3SPaolo Bonzini 586204d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5863c50d8ae3SPaolo Bonzini { 5864c50d8ae3SPaolo Bonzini struct page *page; 5865c50d8ae3SPaolo Bonzini int i; 5866c50d8ae3SPaolo Bonzini 5867b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5868b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 586904d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 587004d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 587104d28e37SSean Christopherson 587227f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 587327f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 587427f4fca2SLai Jiangshan return 0; 587527f4fca2SLai Jiangshan 5876c50d8ae3SPaolo Bonzini /* 5877c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5878c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5879c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5880c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 588104d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 588204d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 588304d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 588404d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 588584432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5886c50d8ae3SPaolo Bonzini */ 5887d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5888c50d8ae3SPaolo Bonzini return 0; 5889c50d8ae3SPaolo Bonzini 5890c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5891c50d8ae3SPaolo Bonzini if (!page) 5892c50d8ae3SPaolo Bonzini return -ENOMEM; 5893c50d8ae3SPaolo Bonzini 5894c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 58954a98623dSSean Christopherson 58964a98623dSSean Christopherson /* 58974a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 58984a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 58994a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 59004a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 59014a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 59024a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 59034a98623dSSean Christopherson */ 59044a98623dSSean Christopherson if (!tdp_enabled) 59054a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 59064a98623dSSean Christopherson else 5907e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 59084a98623dSSean Christopherson 5909c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 5910c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 5911c50d8ae3SPaolo Bonzini 5912c50d8ae3SPaolo Bonzini return 0; 5913c50d8ae3SPaolo Bonzini } 5914c50d8ae3SPaolo Bonzini 5915c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 5916c50d8ae3SPaolo Bonzini { 5917c50d8ae3SPaolo Bonzini int ret; 5918c50d8ae3SPaolo Bonzini 59195962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 59205f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 59215f6078f9SSean Christopherson 59225962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 59235f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 59245962bfb7SSean Christopherson 592596880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 592696880883SSean Christopherson 5927c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 5928c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 5929c50d8ae3SPaolo Bonzini 593004d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 5931c50d8ae3SPaolo Bonzini if (ret) 5932c50d8ae3SPaolo Bonzini return ret; 5933c50d8ae3SPaolo Bonzini 593404d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 5935c50d8ae3SPaolo Bonzini if (ret) 5936c50d8ae3SPaolo Bonzini goto fail_allocate_root; 5937c50d8ae3SPaolo Bonzini 5938c50d8ae3SPaolo Bonzini return ret; 5939c50d8ae3SPaolo Bonzini fail_allocate_root: 5940c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 5941c50d8ae3SPaolo Bonzini return ret; 5942c50d8ae3SPaolo Bonzini } 5943c50d8ae3SPaolo Bonzini 5944c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 5945c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 5946c50d8ae3SPaolo Bonzini { 5947c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 5948c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 5949b28cb0cdSSean Christopherson bool unstable; 5950c50d8ae3SPaolo Bonzini 5951c50d8ae3SPaolo Bonzini restart: 5952c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 5953c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 5954c50d8ae3SPaolo Bonzini /* 5955c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 5956c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 5957c50d8ae3SPaolo Bonzini */ 5958c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 5959c50d8ae3SPaolo Bonzini break; 5960c50d8ae3SPaolo Bonzini 5961c50d8ae3SPaolo Bonzini /* 5962f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 5963f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 5964f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 5965c50d8ae3SPaolo Bonzini */ 5966f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 5967c50d8ae3SPaolo Bonzini continue; 5968c50d8ae3SPaolo Bonzini 5969c50d8ae3SPaolo Bonzini /* 5970c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 5971c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 5972c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 5973c50d8ae3SPaolo Bonzini * be in active use by the guest. 5974c50d8ae3SPaolo Bonzini */ 5975c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 5976531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 5977c50d8ae3SPaolo Bonzini batch = 0; 5978c50d8ae3SPaolo Bonzini goto restart; 5979c50d8ae3SPaolo Bonzini } 5980c50d8ae3SPaolo Bonzini 5981b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 5982b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 5983c50d8ae3SPaolo Bonzini batch += nr_zapped; 5984b28cb0cdSSean Christopherson 5985b28cb0cdSSean Christopherson if (unstable) 5986c50d8ae3SPaolo Bonzini goto restart; 5987c50d8ae3SPaolo Bonzini } 5988c50d8ae3SPaolo Bonzini 5989c50d8ae3SPaolo Bonzini /* 59907ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 59917ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 59927ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 59937ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 59947ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 59957ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 59967ae5840eSSean Christopherson * running with an obsolete MMU. 5997c50d8ae3SPaolo Bonzini */ 5998c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 5999c50d8ae3SPaolo Bonzini } 6000c50d8ae3SPaolo Bonzini 6001c50d8ae3SPaolo Bonzini /* 6002c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 6003c50d8ae3SPaolo Bonzini * to zap obsolete pages. 6004c50d8ae3SPaolo Bonzini * 6005c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 6006c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 6007c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 6008c50d8ae3SPaolo Bonzini * after calling the function. 6009c50d8ae3SPaolo Bonzini */ 6010c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 6011c50d8ae3SPaolo Bonzini { 6012c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 6013c50d8ae3SPaolo Bonzini 6014531810caSBen Gardon write_lock(&kvm->mmu_lock); 6015c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 6016c50d8ae3SPaolo Bonzini 6017c50d8ae3SPaolo Bonzini /* 6018c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 6019c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 6020c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 6021c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 6022c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 6023c50d8ae3SPaolo Bonzini */ 6024c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 6025c50d8ae3SPaolo Bonzini 60262f6f66ccSSean Christopherson /* 60272f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 60282f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 60292f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 60302f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 6031b7cccd39SBen Gardon */ 60321f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6033b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 6034b7cccd39SBen Gardon 6035c50d8ae3SPaolo Bonzini /* 6036c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 6037c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 6038c50d8ae3SPaolo Bonzini * mmu_valid_gen. 6039c50d8ae3SPaolo Bonzini * 6040c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 6041c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 6042c50d8ae3SPaolo Bonzini */ 6043527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 6044c50d8ae3SPaolo Bonzini 6045c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 6046faaf05b0SBen Gardon 6047531810caSBen Gardon write_unlock(&kvm->mmu_lock); 60484c6654bdSBen Gardon 6049f28e9c7fSSean Christopherson /* 6050f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 6051f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 6052f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 6053f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 6054f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 6055f28e9c7fSSean Christopherson * lead to use-after-free. 6056f28e9c7fSSean Christopherson */ 60571f98f2bdSDavid Matlack if (tdp_mmu_enabled) 60584c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 6059c50d8ae3SPaolo Bonzini } 6060c50d8ae3SPaolo Bonzini 6061c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 6062c50d8ae3SPaolo Bonzini { 6063c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 6064c50d8ae3SPaolo Bonzini } 6065c50d8ae3SPaolo Bonzini 6066c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 6067c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 6068c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 6069c50d8ae3SPaolo Bonzini { 6070c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6071c50d8ae3SPaolo Bonzini } 6072c50d8ae3SPaolo Bonzini 6073a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 6074c50d8ae3SPaolo Bonzini { 6075c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6076a1a39128SPaolo Bonzini int r; 6077c50d8ae3SPaolo Bonzini 6078a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 6079a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 608055c510e2SSean Christopherson INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages); 6081ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 6082ce25681dSSean Christopherson 608309732d2bSDavid Matlack if (tdp_mmu_enabled) { 6084a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 6085a1a39128SPaolo Bonzini if (r < 0) 6086a1a39128SPaolo Bonzini return r; 608709732d2bSDavid Matlack } 6088fe5db27dSBen Gardon 6089c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 6090c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 6091c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 6092ada51a9dSDavid Matlack 6093ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 6094ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 6095ada51a9dSDavid Matlack 6096ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 6097ada51a9dSDavid Matlack 6098ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 6099ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 6100ada51a9dSDavid Matlack 6101a1a39128SPaolo Bonzini return 0; 6102c50d8ae3SPaolo Bonzini } 6103c50d8ae3SPaolo Bonzini 6104ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 6105ada51a9dSDavid Matlack { 6106ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 6107ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6108ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6109ada51a9dSDavid Matlack } 6110ada51a9dSDavid Matlack 6111c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6112c50d8ae3SPaolo Bonzini { 6113c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6114c50d8ae3SPaolo Bonzini 6115c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 6116fe5db27dSBen Gardon 611709732d2bSDavid Matlack if (tdp_mmu_enabled) 6118fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6119ada51a9dSDavid Matlack 6120ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6121c50d8ae3SPaolo Bonzini } 6122c50d8ae3SPaolo Bonzini 61232833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 612421fa3246SSean Christopherson { 612521fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 612621fa3246SSean Christopherson struct kvm_memslots *slots; 6127f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 612821fa3246SSean Christopherson bool flush = false; 612921fa3246SSean Christopherson gfn_t start, end; 6130f4209439SMaciej S. Szmigiero int i; 613121fa3246SSean Christopherson 613221fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 613321fa3246SSean Christopherson return flush; 613421fa3246SSean Christopherson 613521fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 613621fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6137f4209439SMaciej S. Szmigiero 6138f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6139f4209439SMaciej S. Szmigiero memslot = iter.slot; 614021fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 614121fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6142f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 614321fa3246SSean Christopherson continue; 614421fa3246SSean Christopherson 6145f8480721SSean Christopherson flush = slot_handle_level_range(kvm, memslot, __kvm_zap_rmap, 614621fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 614721fa3246SSean Christopherson start, end - 1, true, flush); 614821fa3246SSean Christopherson } 614921fa3246SSean Christopherson } 615021fa3246SSean Christopherson 615121fa3246SSean Christopherson return flush; 615221fa3246SSean Christopherson } 615321fa3246SSean Christopherson 615488f58535SMaxim Levitsky /* 615588f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 615688f58535SMaxim Levitsky * (not including it) 615788f58535SMaxim Levitsky */ 6158c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6159c50d8ae3SPaolo Bonzini { 616021fa3246SSean Christopherson bool flush; 6161c50d8ae3SPaolo Bonzini int i; 6162c50d8ae3SPaolo Bonzini 6163f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6164f4209439SMaciej S. Szmigiero return; 6165f4209439SMaciej S. Szmigiero 6166531810caSBen Gardon write_lock(&kvm->mmu_lock); 61675a324c24SSean Christopherson 616820ec3ebdSChao Peng kvm_mmu_invalidate_begin(kvm, gfn_start, gfn_end); 6169edb298c6SMaxim Levitsky 61702833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 61716103bc07SBen Gardon 61721f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 61736103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 6174f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 6175f47e5bbbSSean Christopherson gfn_end, true, flush); 61766103bc07SBen Gardon } 61775a324c24SSean Christopherson 61785a324c24SSean Christopherson if (flush) 6179bc3b3c10SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, gfn_start, 6180bc3b3c10SSean Christopherson gfn_end - gfn_start); 61815a324c24SSean Christopherson 618220ec3ebdSChao Peng kvm_mmu_invalidate_end(kvm, gfn_start, gfn_end); 6183edb298c6SMaxim Levitsky 61845a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6185c50d8ae3SPaolo Bonzini } 6186c50d8ae3SPaolo Bonzini 6187c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 61880a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6189269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6190c50d8ae3SPaolo Bonzini { 61911346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6192c50d8ae3SPaolo Bonzini } 6193c50d8ae3SPaolo Bonzini 6194c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6195269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 61963c9bd400SJay Zhou int start_level) 6197c50d8ae3SPaolo Bonzini { 6198e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6199531810caSBen Gardon write_lock(&kvm->mmu_lock); 6200b64d740eSJunaid Shahid slot_handle_level(kvm, memslot, slot_rmap_write_protect, 6201b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6202531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6203e2209710SBen Gardon } 6204c50d8ae3SPaolo Bonzini 62051f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 620624ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6207b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 620824ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 620924ae4cfaSBen Gardon } 6210c50d8ae3SPaolo Bonzini } 6211c50d8ae3SPaolo Bonzini 6212ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6213ada51a9dSDavid Matlack { 6214ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6215ada51a9dSDavid Matlack } 6216ada51a9dSDavid Matlack 6217ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6218ada51a9dSDavid Matlack { 6219ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6220ada51a9dSDavid Matlack return true; 6221ada51a9dSDavid Matlack 6222ada51a9dSDavid Matlack /* 6223ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6224ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6225ada51a9dSDavid Matlack * is possible but not worth the complexity. 6226ada51a9dSDavid Matlack */ 6227ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6228ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6229ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6230ada51a9dSDavid Matlack } 6231ada51a9dSDavid Matlack 6232ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6233ada51a9dSDavid Matlack { 6234b9b71f43SSean Christopherson /* 6235b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6236dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6237b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6238dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6239dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6240dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6241dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6242dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6243dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6244dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6245b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6246b9b71f43SSean Christopherson */ 6247b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6248b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6249ada51a9dSDavid Matlack int r; 6250ada51a9dSDavid Matlack 6251ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6252ada51a9dSDavid Matlack 6253b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6254ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6255ada51a9dSDavid Matlack if (r) 6256ada51a9dSDavid Matlack return r; 6257ada51a9dSDavid Matlack 6258ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6259ada51a9dSDavid Matlack if (r) 6260ada51a9dSDavid Matlack return r; 6261ada51a9dSDavid Matlack 6262ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6263ada51a9dSDavid Matlack } 6264ada51a9dSDavid Matlack 6265ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6266ada51a9dSDavid Matlack { 6267ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6268ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6269ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6270ada51a9dSDavid Matlack unsigned int access; 6271ada51a9dSDavid Matlack gfn_t gfn; 6272ada51a9dSDavid Matlack 627379e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 627479e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6275ada51a9dSDavid Matlack 6276ada51a9dSDavid Matlack /* 6277ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6278ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6279ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6280ada51a9dSDavid Matlack * mapped with smaller pages. 6281ada51a9dSDavid Matlack */ 6282ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6283ada51a9dSDavid Matlack 6284ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6285ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6286ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6287ada51a9dSDavid Matlack 6288ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6289ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6290ada51a9dSDavid Matlack } 6291ada51a9dSDavid Matlack 6292ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6293ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6294ada51a9dSDavid Matlack u64 *huge_sptep) 6295ada51a9dSDavid Matlack 6296ada51a9dSDavid Matlack { 6297ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6298ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6299ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 630003787394SPaolo Bonzini bool flush = false; 6301ada51a9dSDavid Matlack u64 *sptep, spte; 6302ada51a9dSDavid Matlack gfn_t gfn; 6303ada51a9dSDavid Matlack int index; 6304ada51a9dSDavid Matlack 6305ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6306ada51a9dSDavid Matlack 6307ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6308ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6309ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6310ada51a9dSDavid Matlack 6311ada51a9dSDavid Matlack /* 6312ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6313ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6314ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6315ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6316ada51a9dSDavid Matlack * modify them. 6317ada51a9dSDavid Matlack * 631803787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 631903787394SPaolo Bonzini * that lower level page table may only be partially populated. 632003787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 632103787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 632203787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 632303787394SPaolo Bonzini * fail to detect the need to flush. 6324ada51a9dSDavid Matlack */ 632503787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 632603787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6327ada51a9dSDavid Matlack continue; 632803787394SPaolo Bonzini } 6329ada51a9dSDavid Matlack 6330ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6331ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6332ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6333ada51a9dSDavid Matlack } 6334ada51a9dSDavid Matlack 633503787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6336ada51a9dSDavid Matlack } 6337ada51a9dSDavid Matlack 6338ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6339ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6340ada51a9dSDavid Matlack u64 *huge_sptep) 6341ada51a9dSDavid Matlack { 6342ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6343ada51a9dSDavid Matlack int level, r = 0; 6344ada51a9dSDavid Matlack gfn_t gfn; 6345ada51a9dSDavid Matlack u64 spte; 6346ada51a9dSDavid Matlack 6347ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 634879e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6349ada51a9dSDavid Matlack level = huge_sp->role.level; 6350ada51a9dSDavid Matlack spte = *huge_sptep; 6351ada51a9dSDavid Matlack 6352ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6353ada51a9dSDavid Matlack r = -ENOSPC; 6354ada51a9dSDavid Matlack goto out; 6355ada51a9dSDavid Matlack } 6356ada51a9dSDavid Matlack 6357ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6358ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6359ada51a9dSDavid Matlack cond_resched(); 6360ada51a9dSDavid Matlack /* 6361ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6362ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6363ada51a9dSDavid Matlack * dropped. 6364ada51a9dSDavid Matlack */ 6365ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6366ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6367ada51a9dSDavid Matlack goto out; 6368ada51a9dSDavid Matlack } 6369ada51a9dSDavid Matlack 6370ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6371ada51a9dSDavid Matlack 6372ada51a9dSDavid Matlack out: 6373ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6374ada51a9dSDavid Matlack return r; 6375ada51a9dSDavid Matlack } 6376ada51a9dSDavid Matlack 6377ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6378ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6379ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6380ada51a9dSDavid Matlack { 6381ada51a9dSDavid Matlack struct rmap_iterator iter; 6382ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6383ada51a9dSDavid Matlack u64 *huge_sptep; 6384ada51a9dSDavid Matlack int r; 6385ada51a9dSDavid Matlack 6386ada51a9dSDavid Matlack restart: 6387ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6388ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6389ada51a9dSDavid Matlack 6390ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6391ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6392ada51a9dSDavid Matlack continue; 6393ada51a9dSDavid Matlack 6394ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6395ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6396ada51a9dSDavid Matlack continue; 6397ada51a9dSDavid Matlack 6398ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6399ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6400ada51a9dSDavid Matlack continue; 6401ada51a9dSDavid Matlack 6402ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6403ada51a9dSDavid Matlack if (sp->role.invalid) 6404ada51a9dSDavid Matlack continue; 6405ada51a9dSDavid Matlack 6406ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6407ada51a9dSDavid Matlack 6408ada51a9dSDavid Matlack /* 6409ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6410ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6411ada51a9dSDavid Matlack * back into a consistent state. 6412ada51a9dSDavid Matlack */ 6413ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6414ada51a9dSDavid Matlack goto restart; 6415ada51a9dSDavid Matlack 6416ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6417ada51a9dSDavid Matlack break; 6418ada51a9dSDavid Matlack } 6419ada51a9dSDavid Matlack 6420ada51a9dSDavid Matlack return false; 6421ada51a9dSDavid Matlack } 6422ada51a9dSDavid Matlack 6423ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6424ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6425ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6426ada51a9dSDavid Matlack int target_level) 6427ada51a9dSDavid Matlack { 6428ada51a9dSDavid Matlack int level; 6429ada51a9dSDavid Matlack 6430ada51a9dSDavid Matlack /* 6431ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6432ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6433ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6434ada51a9dSDavid Matlack * already at the target level. 6435ada51a9dSDavid Matlack */ 6436ada51a9dSDavid Matlack for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) { 6437ada51a9dSDavid Matlack slot_handle_level_range(kvm, slot, shadow_mmu_try_split_huge_pages, 6438ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6439ada51a9dSDavid Matlack } 6440ada51a9dSDavid Matlack } 6441ada51a9dSDavid Matlack 6442cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6443cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6444cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6445cb00a70bSDavid Matlack u64 start, u64 end, 6446cb00a70bSDavid Matlack int target_level) 6447cb00a70bSDavid Matlack { 64481f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6449ada51a9dSDavid Matlack return; 6450ada51a9dSDavid Matlack 6451ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6452ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6453ada51a9dSDavid Matlack 6454ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6455cb00a70bSDavid Matlack 6456cb00a70bSDavid Matlack /* 6457cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6458cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6459cb00a70bSDavid Matlack */ 6460cb00a70bSDavid Matlack } 6461cb00a70bSDavid Matlack 6462a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6463a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6464a3fe5dbdSDavid Matlack int target_level) 6465a3fe5dbdSDavid Matlack { 6466a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6467a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6468a3fe5dbdSDavid Matlack 64691f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6470ada51a9dSDavid Matlack return; 6471ada51a9dSDavid Matlack 6472ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6473ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6474ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6475ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6476ada51a9dSDavid Matlack } 6477ada51a9dSDavid Matlack 6478a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6479cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6480a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6481a3fe5dbdSDavid Matlack 6482a3fe5dbdSDavid Matlack /* 6483a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6484a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6485a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6486a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6487a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6488a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6489a3fe5dbdSDavid Matlack * SPTEs. 6490a3fe5dbdSDavid Matlack */ 6491a3fe5dbdSDavid Matlack } 6492a3fe5dbdSDavid Matlack 6493c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 64940a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6495269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6496c50d8ae3SPaolo Bonzini { 6497c50d8ae3SPaolo Bonzini u64 *sptep; 6498c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6499c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6500c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6501c50d8ae3SPaolo Bonzini 6502c50d8ae3SPaolo Bonzini restart: 6503c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 650457354682SSean Christopherson sp = sptep_to_sp(sptep); 6505c50d8ae3SPaolo Bonzini 6506c50d8ae3SPaolo Bonzini /* 6507c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6508c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6509c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6510c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6511c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6512c50d8ae3SPaolo Bonzini */ 65135d49f08cSSean Christopherson if (sp->role.direct && 65149eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6515a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 65169202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6517c50d8ae3SPaolo Bonzini 6518c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 6519c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, 6520c50d8ae3SPaolo Bonzini KVM_PAGES_PER_HPAGE(sp->role.level)); 6521c50d8ae3SPaolo Bonzini else 6522c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6523c50d8ae3SPaolo Bonzini 6524c50d8ae3SPaolo Bonzini goto restart; 6525c50d8ae3SPaolo Bonzini } 6526c50d8ae3SPaolo Bonzini } 6527c50d8ae3SPaolo Bonzini 6528c50d8ae3SPaolo Bonzini return need_tlb_flush; 6529c50d8ae3SPaolo Bonzini } 6530c50d8ae3SPaolo Bonzini 653120d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 653220d49186SDavid Matlack const struct kvm_memory_slot *slot) 653320d49186SDavid Matlack { 653420d49186SDavid Matlack /* 653520d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 653620d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 653720d49186SDavid Matlack */ 653820d49186SDavid Matlack if (slot_handle_level(kvm, slot, kvm_mmu_zap_collapsible_spte, 653920d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 654020d49186SDavid Matlack kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 654120d49186SDavid Matlack } 654220d49186SDavid Matlack 6543c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6544269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6545c50d8ae3SPaolo Bonzini { 6546e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6547531810caSBen Gardon write_lock(&kvm->mmu_lock); 654820d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6549531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6550e2209710SBen Gardon } 65512db6f772SBen Gardon 65521f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 65532db6f772SBen Gardon read_lock(&kvm->mmu_lock); 65544b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 65552db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 65562db6f772SBen Gardon } 6557c50d8ae3SPaolo Bonzini } 6558c50d8ae3SPaolo Bonzini 6559b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 65606c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6561b3594ffbSSean Christopherson { 6562b3594ffbSSean Christopherson /* 65637f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6564302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 65657f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 65667f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 65677f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6568b3594ffbSSean Christopherson */ 6569b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 6570cec37648SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn, 6571cec37648SSean Christopherson memslot->npages); 6572b3594ffbSSean Christopherson } 6573b3594ffbSSean Christopherson 6574c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6575269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6576c50d8ae3SPaolo Bonzini { 6577e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6578531810caSBen Gardon write_lock(&kvm->mmu_lock); 6579610265eaSDavid Matlack /* 6580610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6581610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6582610265eaSDavid Matlack */ 6583b64d740eSJunaid Shahid slot_handle_level_4k(kvm, memslot, __rmap_clear_dirty, false); 6584531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6585e2209710SBen Gardon } 6586c50d8ae3SPaolo Bonzini 65871f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 658824ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6589b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 659024ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 659124ae4cfaSBen Gardon } 659224ae4cfaSBen Gardon 6593c50d8ae3SPaolo Bonzini /* 6594b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6595b64d740eSJunaid Shahid * 6596c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6597c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6598c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6599c50d8ae3SPaolo Bonzini * dirty_bitmap. 6600c50d8ae3SPaolo Bonzini */ 6601c50d8ae3SPaolo Bonzini } 6602c50d8ae3SPaolo Bonzini 6603c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6604c50d8ae3SPaolo Bonzini { 6605c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6606c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6607c50d8ae3SPaolo Bonzini int ign; 6608c50d8ae3SPaolo Bonzini 6609531810caSBen Gardon write_lock(&kvm->mmu_lock); 6610c50d8ae3SPaolo Bonzini restart: 6611c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6612f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6613c50d8ae3SPaolo Bonzini continue; 6614c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6615c50d8ae3SPaolo Bonzini goto restart; 6616531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6617c50d8ae3SPaolo Bonzini goto restart; 6618c50d8ae3SPaolo Bonzini } 6619c50d8ae3SPaolo Bonzini 6620c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6621faaf05b0SBen Gardon 66221f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6623faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6624faaf05b0SBen Gardon 6625531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6626c50d8ae3SPaolo Bonzini } 6627c50d8ae3SPaolo Bonzini 6628c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6629c50d8ae3SPaolo Bonzini { 6630c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6631c50d8ae3SPaolo Bonzini 6632c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6633c50d8ae3SPaolo Bonzini 6634c50d8ae3SPaolo Bonzini /* 6635c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6636c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6637c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6638c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6639c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6640c50d8ae3SPaolo Bonzini */ 6641c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6642c50d8ae3SPaolo Bonzini 6643c50d8ae3SPaolo Bonzini /* 6644c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6645c50d8ae3SPaolo Bonzini * zap all shadow pages. 6646c50d8ae3SPaolo Bonzini */ 6647c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 6648c50d8ae3SPaolo Bonzini kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n"); 6649c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6650c50d8ae3SPaolo Bonzini } 6651c50d8ae3SPaolo Bonzini } 6652c50d8ae3SPaolo Bonzini 6653c50d8ae3SPaolo Bonzini static unsigned long 6654c50d8ae3SPaolo Bonzini mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 6655c50d8ae3SPaolo Bonzini { 6656c50d8ae3SPaolo Bonzini struct kvm *kvm; 6657c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6658c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6659c50d8ae3SPaolo Bonzini 6660c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6661c50d8ae3SPaolo Bonzini 6662c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6663c50d8ae3SPaolo Bonzini int idx; 6664c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6665c50d8ae3SPaolo Bonzini 6666c50d8ae3SPaolo Bonzini /* 6667c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6668c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6669c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6670c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6671c50d8ae3SPaolo Bonzini */ 6672c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6673c50d8ae3SPaolo Bonzini break; 6674c50d8ae3SPaolo Bonzini /* 6675c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6676c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6677c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6678c50d8ae3SPaolo Bonzini * anyway. 6679c50d8ae3SPaolo Bonzini */ 6680c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6681c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6682c50d8ae3SPaolo Bonzini continue; 6683c50d8ae3SPaolo Bonzini 6684c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6685531810caSBen Gardon write_lock(&kvm->mmu_lock); 6686c50d8ae3SPaolo Bonzini 6687c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6688c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6689c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6690c50d8ae3SPaolo Bonzini goto unlock; 6691c50d8ae3SPaolo Bonzini } 6692c50d8ae3SPaolo Bonzini 6693ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6694c50d8ae3SPaolo Bonzini 6695c50d8ae3SPaolo Bonzini unlock: 6696531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6697c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6698c50d8ae3SPaolo Bonzini 6699c50d8ae3SPaolo Bonzini /* 6700c50d8ae3SPaolo Bonzini * unfair on small ones 6701c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6702c50d8ae3SPaolo Bonzini * sadness comes quickly 6703c50d8ae3SPaolo Bonzini */ 6704c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6705c50d8ae3SPaolo Bonzini break; 6706c50d8ae3SPaolo Bonzini } 6707c50d8ae3SPaolo Bonzini 6708c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6709c50d8ae3SPaolo Bonzini return freed; 6710c50d8ae3SPaolo Bonzini } 6711c50d8ae3SPaolo Bonzini 6712c50d8ae3SPaolo Bonzini static unsigned long 6713c50d8ae3SPaolo Bonzini mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 6714c50d8ae3SPaolo Bonzini { 6715c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6716c50d8ae3SPaolo Bonzini } 6717c50d8ae3SPaolo Bonzini 6718c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6719c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6720c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6721c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6722c50d8ae3SPaolo Bonzini }; 6723c50d8ae3SPaolo Bonzini 6724c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6725c50d8ae3SPaolo Bonzini { 6726c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6727c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6728c50d8ae3SPaolo Bonzini } 6729c50d8ae3SPaolo Bonzini 6730c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6731c50d8ae3SPaolo Bonzini { 6732c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6733c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6734c50d8ae3SPaolo Bonzini } 6735c50d8ae3SPaolo Bonzini 6736c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6737c50d8ae3SPaolo Bonzini { 6738c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6739c50d8ae3SPaolo Bonzini } 6740c50d8ae3SPaolo Bonzini 6741c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6742c50d8ae3SPaolo Bonzini { 6743c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6744c50d8ae3SPaolo Bonzini bool new_val; 6745c50d8ae3SPaolo Bonzini 6746c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6747c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6748c50d8ae3SPaolo Bonzini new_val = 0; 6749c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6750c50d8ae3SPaolo Bonzini new_val = 1; 6751c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6752c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 6753c50d8ae3SPaolo Bonzini else if (strtobool(val, &new_val) < 0) 6754c50d8ae3SPaolo Bonzini return -EINVAL; 6755c50d8ae3SPaolo Bonzini 6756c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6757c50d8ae3SPaolo Bonzini 6758c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6759c50d8ae3SPaolo Bonzini struct kvm *kvm; 6760c50d8ae3SPaolo Bonzini 6761c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6762c50d8ae3SPaolo Bonzini 6763c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6764c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6765c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6766c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6767c50d8ae3SPaolo Bonzini 676855c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 6769c50d8ae3SPaolo Bonzini } 6770c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6771c50d8ae3SPaolo Bonzini } 6772c50d8ae3SPaolo Bonzini 6773c50d8ae3SPaolo Bonzini return 0; 6774c50d8ae3SPaolo Bonzini } 6775c50d8ae3SPaolo Bonzini 67761d0e8480SSean Christopherson /* 67771d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 67781d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 6779c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 6780c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 67811d0e8480SSean Christopherson */ 6782982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 6783c50d8ae3SPaolo Bonzini { 6784c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6785c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 6786c3e0c8c2SSean Christopherson 67871f98f2bdSDavid Matlack /* 67881f98f2bdSDavid Matlack * Snapshot userspace's desire to enable the TDP MMU. Whether or not the 67891f98f2bdSDavid Matlack * TDP MMU is actually enabled is determined in kvm_configure_mmu() 67901f98f2bdSDavid Matlack * when the vendor module is loaded. 67911f98f2bdSDavid Matlack */ 67921f98f2bdSDavid Matlack tdp_mmu_allowed = tdp_mmu_enabled; 67931f98f2bdSDavid Matlack 6794c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 67951d0e8480SSean Christopherson } 67961d0e8480SSean Christopherson 67971d0e8480SSean Christopherson /* 67981d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 67991d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 68001d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 68011d0e8480SSean Christopherson */ 68021d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 68031d0e8480SSean Christopherson { 68041d0e8480SSean Christopherson int ret = -ENOMEM; 6805c50d8ae3SPaolo Bonzini 6806c50d8ae3SPaolo Bonzini /* 6807c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6808c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6809c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6810c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6811c50d8ae3SPaolo Bonzini */ 6812c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6813c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 68147a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6815c50d8ae3SPaolo Bonzini 6816c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6817c50d8ae3SPaolo Bonzini 6818c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6819c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6820c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6821c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6822c50d8ae3SPaolo Bonzini goto out; 6823c50d8ae3SPaolo Bonzini 6824c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6825c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6826c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6827c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6828c50d8ae3SPaolo Bonzini goto out; 6829c50d8ae3SPaolo Bonzini 6830c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6831c50d8ae3SPaolo Bonzini goto out; 6832c50d8ae3SPaolo Bonzini 6833e33c267aSRoman Gushchin ret = register_shrinker(&mmu_shrinker, "x86-mmu"); 6834c50d8ae3SPaolo Bonzini if (ret) 6835d7c9bfb9SMiaohe Lin goto out_shrinker; 6836c50d8ae3SPaolo Bonzini 6837c50d8ae3SPaolo Bonzini return 0; 6838c50d8ae3SPaolo Bonzini 6839d7c9bfb9SMiaohe Lin out_shrinker: 6840d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 6841c50d8ae3SPaolo Bonzini out: 6842c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6843c50d8ae3SPaolo Bonzini return ret; 6844c50d8ae3SPaolo Bonzini } 6845c50d8ae3SPaolo Bonzini 6846c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6847c50d8ae3SPaolo Bonzini { 6848c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6849c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6850c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6851c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6852c50d8ae3SPaolo Bonzini } 6853c50d8ae3SPaolo Bonzini 68541d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6855c50d8ae3SPaolo Bonzini { 6856c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6857c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6858c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6859c50d8ae3SPaolo Bonzini } 6860c50d8ae3SPaolo Bonzini 6861f47491d7SSean Christopherson /* 6862f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6863f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6864f47491d7SSean Christopherson */ 6865f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6866f47491d7SSean Christopherson { 6867f47491d7SSean Christopherson /* 6868f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6869f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6870f47491d7SSean Christopherson */ 6871f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6872f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6873f47491d7SSean Christopherson 6874f47491d7SSean Christopherson if (!enabled || !ratio) 6875f47491d7SSean Christopherson return false; 6876f47491d7SSean Christopherson 6877f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6878f47491d7SSean Christopherson if (!*period) { 6879f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6880f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6881f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6882f47491d7SSean Christopherson } 6883f47491d7SSean Christopherson return true; 6884f47491d7SSean Christopherson } 6885f47491d7SSean Christopherson 68864dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6887c50d8ae3SPaolo Bonzini { 68884dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 68894dfe4f40SJunaid Shahid uint old_period, new_period; 6890c50d8ae3SPaolo Bonzini int err; 6891c50d8ae3SPaolo Bonzini 6892f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 68934dfe4f40SJunaid Shahid 6894c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 6895c50d8ae3SPaolo Bonzini if (err) 6896c50d8ae3SPaolo Bonzini return err; 6897c50d8ae3SPaolo Bonzini 6898f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 68994dfe4f40SJunaid Shahid 6900f47491d7SSean Christopherson if (is_recovery_enabled && 69014dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 6902c50d8ae3SPaolo Bonzini struct kvm *kvm; 6903c50d8ae3SPaolo Bonzini 6904c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6905c50d8ae3SPaolo Bonzini 6906c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 690755c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 6908c50d8ae3SPaolo Bonzini 6909c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6910c50d8ae3SPaolo Bonzini } 6911c50d8ae3SPaolo Bonzini 6912c50d8ae3SPaolo Bonzini return err; 6913c50d8ae3SPaolo Bonzini } 6914c50d8ae3SPaolo Bonzini 691555c510e2SSean Christopherson static void kvm_recover_nx_huge_pages(struct kvm *kvm) 6916c50d8ae3SPaolo Bonzini { 6917ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 6918eb298605SDavid Matlack struct kvm_memory_slot *slot; 6919c50d8ae3SPaolo Bonzini int rcu_idx; 6920c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6921c50d8ae3SPaolo Bonzini unsigned int ratio; 6922c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6923048f4980SSean Christopherson bool flush = false; 6924c50d8ae3SPaolo Bonzini ulong to_zap; 6925c50d8ae3SPaolo Bonzini 6926c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 6927531810caSBen Gardon write_lock(&kvm->mmu_lock); 6928c50d8ae3SPaolo Bonzini 6929bb95dfb9SSean Christopherson /* 6930bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 6931bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 6932bb95dfb9SSean Christopherson * callback. 6933bb95dfb9SSean Christopherson */ 6934bb95dfb9SSean Christopherson rcu_read_lock(); 6935bb95dfb9SSean Christopherson 6936c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6937ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 69387d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 693955c510e2SSean Christopherson if (list_empty(&kvm->arch.possible_nx_huge_pages)) 69407d919c7aSSean Christopherson break; 69417d919c7aSSean Christopherson 6942c50d8ae3SPaolo Bonzini /* 6943c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 694455c510e2SSean Christopherson * because the number of shadow pages that be replaced with an 694555c510e2SSean Christopherson * NX huge page is expected to be relatively small compared to 694655c510e2SSean Christopherson * the total number of shadow pages. And because the TDP MMU 694755c510e2SSean Christopherson * doesn't use active_mmu_pages. 6948c50d8ae3SPaolo Bonzini */ 694955c510e2SSean Christopherson sp = list_first_entry(&kvm->arch.possible_nx_huge_pages, 6950c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 695155c510e2SSean Christopherson possible_nx_huge_page_link); 695255c510e2SSean Christopherson WARN_ON_ONCE(!sp->nx_huge_page_disallowed); 6953eb298605SDavid Matlack WARN_ON_ONCE(!sp->role.direct); 6954eb298605SDavid Matlack 6955eb298605SDavid Matlack /* 6956eb298605SDavid Matlack * Unaccount and do not attempt to recover any NX Huge Pages 6957eb298605SDavid Matlack * that are being dirty tracked, as they would just be faulted 6958eb298605SDavid Matlack * back in as 4KiB pages. The NX Huge Pages in this slot will be 6959eb298605SDavid Matlack * recovered, along with all the other huge pages in the slot, 6960eb298605SDavid Matlack * when dirty logging is disabled. 69616c7b2202SPaolo Bonzini * 69626c7b2202SPaolo Bonzini * Since gfn_to_memslot() is relatively expensive, it helps to 69636c7b2202SPaolo Bonzini * skip it if it the test cannot possibly return true. On the 69646c7b2202SPaolo Bonzini * other hand, if any memslot has logging enabled, chances are 69656c7b2202SPaolo Bonzini * good that all of them do, in which case unaccount_nx_huge_page() 69666c7b2202SPaolo Bonzini * is much cheaper than zapping the page. 69676c7b2202SPaolo Bonzini * 69686c7b2202SPaolo Bonzini * If a memslot update is in progress, reading an incorrect value 69696c7b2202SPaolo Bonzini * of kvm->nr_memslots_dirty_logging is not a problem: if it is 69706c7b2202SPaolo Bonzini * becoming zero, gfn_to_memslot() will be done unnecessarily; if 69716c7b2202SPaolo Bonzini * it is becoming nonzero, the page will be zapped unnecessarily. 69726c7b2202SPaolo Bonzini * Either way, this only affects efficiency in racy situations, 69736c7b2202SPaolo Bonzini * and not correctness. 6974eb298605SDavid Matlack */ 69756c7b2202SPaolo Bonzini slot = NULL; 69766c7b2202SPaolo Bonzini if (atomic_read(&kvm->nr_memslots_dirty_logging)) { 69776c7b2202SPaolo Bonzini slot = gfn_to_memslot(kvm, sp->gfn); 69786c7b2202SPaolo Bonzini WARN_ON_ONCE(!slot); 69796c7b2202SPaolo Bonzini } 69806c7b2202SPaolo Bonzini 6981eb298605SDavid Matlack if (slot && kvm_slot_dirty_track_enabled(slot)) 6982eb298605SDavid Matlack unaccount_nx_huge_page(kvm, sp); 6983eb298605SDavid Matlack else if (is_tdp_mmu_page(sp)) 6984315f02c6SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 69853a056757SSean Christopherson else 6986c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 698755c510e2SSean Christopherson WARN_ON_ONCE(sp->nx_huge_page_disallowed); 6988c50d8ae3SPaolo Bonzini 6989531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6990048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 6991bb95dfb9SSean Christopherson rcu_read_unlock(); 6992bb95dfb9SSean Christopherson 6993531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6994048f4980SSean Christopherson flush = false; 6995bb95dfb9SSean Christopherson 6996bb95dfb9SSean Christopherson rcu_read_lock(); 6997c50d8ae3SPaolo Bonzini } 6998c50d8ae3SPaolo Bonzini } 6999048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7000c50d8ae3SPaolo Bonzini 7001bb95dfb9SSean Christopherson rcu_read_unlock(); 7002bb95dfb9SSean Christopherson 7003531810caSBen Gardon write_unlock(&kvm->mmu_lock); 7004c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 7005c50d8ae3SPaolo Bonzini } 7006c50d8ae3SPaolo Bonzini 700755c510e2SSean Christopherson static long get_nx_huge_page_recovery_timeout(u64 start_time) 7008c50d8ae3SPaolo Bonzini { 7009f47491d7SSean Christopherson bool enabled; 7010f47491d7SSean Christopherson uint period; 70114dfe4f40SJunaid Shahid 7012f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 70134dfe4f40SJunaid Shahid 7014f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 7015c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 7016c50d8ae3SPaolo Bonzini } 7017c50d8ae3SPaolo Bonzini 701855c510e2SSean Christopherson static int kvm_nx_huge_page_recovery_worker(struct kvm *kvm, uintptr_t data) 7019c50d8ae3SPaolo Bonzini { 7020c50d8ae3SPaolo Bonzini u64 start_time; 7021c50d8ae3SPaolo Bonzini long remaining_time; 7022c50d8ae3SPaolo Bonzini 7023c50d8ae3SPaolo Bonzini while (true) { 7024c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 702555c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7026c50d8ae3SPaolo Bonzini 7027c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7028c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 7029c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 703055c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7031c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7032c50d8ae3SPaolo Bonzini } 7033c50d8ae3SPaolo Bonzini 7034c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 7035c50d8ae3SPaolo Bonzini 7036c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 7037c50d8ae3SPaolo Bonzini return 0; 7038c50d8ae3SPaolo Bonzini 703955c510e2SSean Christopherson kvm_recover_nx_huge_pages(kvm); 7040c50d8ae3SPaolo Bonzini } 7041c50d8ae3SPaolo Bonzini } 7042c50d8ae3SPaolo Bonzini 7043c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 7044c50d8ae3SPaolo Bonzini { 7045c50d8ae3SPaolo Bonzini int err; 7046c50d8ae3SPaolo Bonzini 704755c510e2SSean Christopherson err = kvm_vm_create_worker_thread(kvm, kvm_nx_huge_page_recovery_worker, 0, 7048c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 704955c510e2SSean Christopherson &kvm->arch.nx_huge_page_recovery_thread); 7050c50d8ae3SPaolo Bonzini if (!err) 705155c510e2SSean Christopherson kthread_unpark(kvm->arch.nx_huge_page_recovery_thread); 7052c50d8ae3SPaolo Bonzini 7053c50d8ae3SPaolo Bonzini return err; 7054c50d8ae3SPaolo Bonzini } 7055c50d8ae3SPaolo Bonzini 7056c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 7057c50d8ae3SPaolo Bonzini { 705855c510e2SSean Christopherson if (kvm->arch.nx_huge_page_recovery_thread) 705955c510e2SSean Christopherson kthread_stop(kvm->arch.nx_huge_page_recovery_thread); 7060c50d8ae3SPaolo Bonzini } 7061