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 */ 178d20bd63SSean Christopherson #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18c50d8ae3SPaolo Bonzini 19c50d8ae3SPaolo Bonzini #include "irq.h" 2088197e6aS彭浩(Richard) #include "ioapic.h" 21c50d8ae3SPaolo Bonzini #include "mmu.h" 226ca9a6f3SSean Christopherson #include "mmu_internal.h" 23fe5db27dSBen Gardon #include "tdp_mmu.h" 24c50d8ae3SPaolo Bonzini #include "x86.h" 25c50d8ae3SPaolo Bonzini #include "kvm_cache_regs.h" 26b0b42197SPaolo Bonzini #include "smm.h" 272f728d66SSean Christopherson #include "kvm_emulate.h" 28c50d8ae3SPaolo Bonzini #include "cpuid.h" 295a9624afSPaolo Bonzini #include "spte.h" 30c50d8ae3SPaolo Bonzini 31c50d8ae3SPaolo Bonzini #include <linux/kvm_host.h> 32c50d8ae3SPaolo Bonzini #include <linux/types.h> 33c50d8ae3SPaolo Bonzini #include <linux/string.h> 34c50d8ae3SPaolo Bonzini #include <linux/mm.h> 35c50d8ae3SPaolo Bonzini #include <linux/highmem.h> 36c50d8ae3SPaolo Bonzini #include <linux/moduleparam.h> 37c50d8ae3SPaolo Bonzini #include <linux/export.h> 38c50d8ae3SPaolo Bonzini #include <linux/swap.h> 39c50d8ae3SPaolo Bonzini #include <linux/hugetlb.h> 40c50d8ae3SPaolo Bonzini #include <linux/compiler.h> 41c50d8ae3SPaolo Bonzini #include <linux/srcu.h> 42c50d8ae3SPaolo Bonzini #include <linux/slab.h> 43c50d8ae3SPaolo Bonzini #include <linux/sched/signal.h> 44c50d8ae3SPaolo Bonzini #include <linux/uaccess.h> 45c50d8ae3SPaolo Bonzini #include <linux/hash.h> 46c50d8ae3SPaolo Bonzini #include <linux/kern_levels.h> 4711b36fe7SChristophe JAILLET #include <linux/kstrtox.h> 48c50d8ae3SPaolo Bonzini #include <linux/kthread.h> 49c50d8ae3SPaolo Bonzini 50c50d8ae3SPaolo Bonzini #include <asm/page.h> 51eb243d1dSIngo Molnar #include <asm/memtype.h> 52c50d8ae3SPaolo Bonzini #include <asm/cmpxchg.h> 53c50d8ae3SPaolo Bonzini #include <asm/io.h> 544a98623dSSean Christopherson #include <asm/set_memory.h> 55c50d8ae3SPaolo Bonzini #include <asm/vmx.h> 56c50d8ae3SPaolo Bonzini #include <asm/kvm_page_track.h> 57c50d8ae3SPaolo Bonzini #include "trace.h" 58c50d8ae3SPaolo Bonzini 59c50d8ae3SPaolo Bonzini extern bool itlb_multihit_kvm_mitigation; 60c50d8ae3SPaolo Bonzini 610b210fafSSean Christopherson static bool nx_hugepage_mitigation_hard_disabled; 620b210fafSSean Christopherson 63a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 644dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 65c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 66c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 67c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 68c50d8ae3SPaolo Bonzini #else 69c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 70c50d8ae3SPaolo Bonzini #endif 71c50d8ae3SPaolo Bonzini 720b210fafSSean Christopherson static int get_nx_huge_pages(char *buffer, const struct kernel_param *kp); 73c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 744dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 75c50d8ae3SPaolo Bonzini 76d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 77c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 780b210fafSSean Christopherson .get = get_nx_huge_pages, 79c50d8ae3SPaolo Bonzini }; 80c50d8ae3SPaolo Bonzini 814dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 824dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 83c50d8ae3SPaolo Bonzini .get = param_get_uint, 84c50d8ae3SPaolo Bonzini }; 85c50d8ae3SPaolo Bonzini 86c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 87c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 884dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 89c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 90c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 914dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 924dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 934dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 94c50d8ae3SPaolo Bonzini 9571fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9671fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9771fe7013SSean Christopherson 98c50d8ae3SPaolo Bonzini /* 99c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 100c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 101c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 102c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 103c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 104c50d8ae3SPaolo Bonzini */ 105c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 106c50d8ae3SPaolo Bonzini 1077f604e92SDavid Matlack static bool __ro_after_init tdp_mmu_allowed; 1081f98f2bdSDavid Matlack 1091f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 1101f98f2bdSDavid Matlack bool __read_mostly tdp_mmu_enabled = true; 1111f98f2bdSDavid Matlack module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0444); 1121f98f2bdSDavid Matlack #endif 1131f98f2bdSDavid Matlack 1141d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 115746700d2SWei Huang static int tdp_root_level __read_mostly; 11683013059SSean Christopherson static int max_tdp_level __read_mostly; 117703c335dSSean Christopherson 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 /* 126141705b7SLai Jiangshan * struct pte_list_desc is the core data structure used to implement a custom 127141705b7SLai Jiangshan * list for tracking a set of related SPTEs, e.g. all the SPTEs that map a 128141705b7SLai Jiangshan * given GFN when used in the context of rmaps. Using a custom list allows KVM 129141705b7SLai Jiangshan * to optimize for the common case where many GFNs will have at most a handful 130141705b7SLai Jiangshan * of SPTEs pointing at them, i.e. allows packing multiple SPTEs into a small 131141705b7SLai Jiangshan * memory footprint, which in turn improves runtime performance by exploiting 132141705b7SLai Jiangshan * cache locality. 133141705b7SLai Jiangshan * 134141705b7SLai Jiangshan * A list is comprised of one or more pte_list_desc objects (descriptors). 135141705b7SLai Jiangshan * Each individual descriptor stores up to PTE_LIST_EXT SPTEs. If a descriptor 136141705b7SLai Jiangshan * is full and a new SPTEs needs to be added, a new descriptor is allocated and 137141705b7SLai Jiangshan * becomes the head of the list. This means that by definitions, all tail 138141705b7SLai Jiangshan * descriptors are full. 139141705b7SLai Jiangshan * 140141705b7SLai Jiangshan * Note, the meta data fields are deliberately placed at the start of the 141141705b7SLai Jiangshan * structure to optimize the cacheline layout; accessing the descriptor will 142141705b7SLai Jiangshan * touch only a single cacheline so long as @spte_count<=6 (or if only the 143141705b7SLai Jiangshan * descriptors metadata is accessed). 14413236e25SPeter Xu */ 145c50d8ae3SPaolo Bonzini struct pte_list_desc { 146c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 147141705b7SLai Jiangshan /* The number of PTEs stored in _this_ descriptor. */ 148141705b7SLai Jiangshan u32 spte_count; 149141705b7SLai Jiangshan /* The number of PTEs stored in all tails of this descriptor. */ 150141705b7SLai Jiangshan u32 tail_count; 15113236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 152c50d8ae3SPaolo Bonzini }; 153c50d8ae3SPaolo Bonzini 154c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 155c50d8ae3SPaolo Bonzini u64 addr; 156c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 157c50d8ae3SPaolo Bonzini u64 *sptep; 158c50d8ae3SPaolo Bonzini int level; 159c50d8ae3SPaolo Bonzini unsigned index; 160c50d8ae3SPaolo Bonzini }; 161c50d8ae3SPaolo Bonzini 162c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 163c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 164c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 165c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 166c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 167c50d8ae3SPaolo Bonzini 168c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 169c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 170c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 171c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 172c50d8ae3SPaolo Bonzini 173c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 174c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 175c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 176c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 177c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 178c50d8ae3SPaolo Bonzini 179c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 18002c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 181c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 182c50d8ae3SPaolo Bonzini 183c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 184c50d8ae3SPaolo Bonzini 185594e91a1SSean Christopherson struct kvm_mmu_role_regs { 186594e91a1SSean Christopherson const unsigned long cr0; 187594e91a1SSean Christopherson const unsigned long cr4; 188594e91a1SSean Christopherson const u64 efer; 189594e91a1SSean Christopherson }; 190594e91a1SSean Christopherson 191c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 192c50d8ae3SPaolo Bonzini #include "mmutrace.h" 193c50d8ae3SPaolo Bonzini 194594e91a1SSean Christopherson /* 195594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1967a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 197594e91a1SSean Christopherson * the single source of truth for the MMU's state. 198594e91a1SSean Christopherson */ 199594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 20082ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 20182ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 202594e91a1SSean Christopherson { \ 203594e91a1SSean Christopherson return !!(regs->reg & flag); \ 204594e91a1SSean Christopherson } 205594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 206594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 207594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 208594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 209594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 210594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 211594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 212594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 213594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 214594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 215594e91a1SSean Christopherson 21660667724SSean Christopherson /* 21760667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 21860667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 21960667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 22060667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 22160667724SSean Christopherson */ 22260667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2234ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 22460667724SSean Christopherson { \ 225e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 22660667724SSean Christopherson } 22760667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 22860667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 22960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 23060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 23160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 23260667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 23360667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 23456b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 23560667724SSean Christopherson 236faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 237faf72962SPaolo Bonzini { 238faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 239faf72962SPaolo Bonzini } 240faf72962SPaolo Bonzini 241faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 242faf72962SPaolo Bonzini { 243faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 244faf72962SPaolo Bonzini } 245faf72962SPaolo Bonzini 246594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 247594e91a1SSean Christopherson { 248594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 249594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 250594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 251594e91a1SSean Christopherson .efer = vcpu->arch.efer, 252594e91a1SSean Christopherson }; 253594e91a1SSean Christopherson 254594e91a1SSean Christopherson return regs; 255594e91a1SSean Christopherson } 256c50d8ae3SPaolo Bonzini 2572fdcc1b3SPaolo Bonzini static unsigned long get_guest_cr3(struct kvm_vcpu *vcpu) 258c50d8ae3SPaolo Bonzini { 2592fdcc1b3SPaolo Bonzini return kvm_read_cr3(vcpu); 260c50d8ae3SPaolo Bonzini } 261c50d8ae3SPaolo Bonzini 2622fdcc1b3SPaolo Bonzini static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu, 2632fdcc1b3SPaolo Bonzini struct kvm_mmu *mmu) 264c50d8ae3SPaolo Bonzini { 2652fdcc1b3SPaolo Bonzini if (IS_ENABLED(CONFIG_RETPOLINE) && mmu->get_guest_pgd == get_guest_cr3) 2662fdcc1b3SPaolo Bonzini return kvm_read_cr3(vcpu); 267c50d8ae3SPaolo Bonzini 2682fdcc1b3SPaolo Bonzini return mmu->get_guest_pgd(vcpu); 2692fdcc1b3SPaolo Bonzini } 270c50d8ae3SPaolo Bonzini 2718a1300ffSSean Christopherson static inline bool kvm_available_flush_remote_tlbs_range(void) 272c50d8ae3SPaolo Bonzini { 2738a1300ffSSean Christopherson return kvm_x86_ops.flush_remote_tlbs_range; 274c50d8ae3SPaolo Bonzini } 275c50d8ae3SPaolo Bonzini 276d4788996SDavid Matlack int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 nr_pages) 277c50d8ae3SPaolo Bonzini { 278d4788996SDavid Matlack if (!kvm_x86_ops.flush_remote_tlbs_range) 279d4788996SDavid Matlack return -EOPNOTSUPP; 280c50d8ae3SPaolo Bonzini 281d4788996SDavid Matlack return static_call(kvm_x86_flush_remote_tlbs_range)(kvm, gfn, nr_pages); 282c50d8ae3SPaolo Bonzini } 283c50d8ae3SPaolo Bonzini 2841b2dc736SHou Wenlong static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index); 2851b2dc736SHou Wenlong 2861b2dc736SHou Wenlong /* Flush the range of guest memory mapped by the given SPTE. */ 2871b2dc736SHou Wenlong static void kvm_flush_remote_tlbs_sptep(struct kvm *kvm, u64 *sptep) 2881b2dc736SHou Wenlong { 2891b2dc736SHou Wenlong struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2901b2dc736SHou Wenlong gfn_t gfn = kvm_mmu_page_get_gfn(sp, spte_index(sptep)); 2911b2dc736SHou Wenlong 2921b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 2931b2dc736SHou Wenlong } 2941b2dc736SHou Wenlong 2958f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 2968f79b064SBen Gardon unsigned int access) 2978f79b064SBen Gardon { 298c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 2998f79b064SBen Gardon 300c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 301c236d962SSean Christopherson mmu_spte_set(sptep, spte); 302c50d8ae3SPaolo Bonzini } 303c50d8ae3SPaolo Bonzini 304c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 305c50d8ae3SPaolo Bonzini { 306c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 307c50d8ae3SPaolo Bonzini 3088a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 309c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 310c50d8ae3SPaolo Bonzini 311c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 312c50d8ae3SPaolo Bonzini } 313c50d8ae3SPaolo Bonzini 314c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 315c50d8ae3SPaolo Bonzini { 316c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 317c50d8ae3SPaolo Bonzini } 318c50d8ae3SPaolo Bonzini 319c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 320c50d8ae3SPaolo Bonzini { 321c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 322c50d8ae3SPaolo Bonzini 323c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 324c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 325c50d8ae3SPaolo Bonzini return false; 326c50d8ae3SPaolo Bonzini 327c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 328c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 329c50d8ae3SPaolo Bonzini 330c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 331c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 332c50d8ae3SPaolo Bonzini } 333c50d8ae3SPaolo Bonzini 334c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 335c50d8ae3SPaolo Bonzini { 336c50d8ae3SPaolo Bonzini return 1; 337c50d8ae3SPaolo Bonzini } 338c50d8ae3SPaolo Bonzini 339c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 340c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 341c50d8ae3SPaolo Bonzini { 342c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 343c50d8ae3SPaolo Bonzini } 344c50d8ae3SPaolo Bonzini 345c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 346c50d8ae3SPaolo Bonzini { 347c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 348c50d8ae3SPaolo Bonzini } 349c50d8ae3SPaolo Bonzini 350c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 351c50d8ae3SPaolo Bonzini { 352c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 353c50d8ae3SPaolo Bonzini } 354c50d8ae3SPaolo Bonzini 355c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 356c50d8ae3SPaolo Bonzini { 357c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 358c50d8ae3SPaolo Bonzini } 359c50d8ae3SPaolo Bonzini #else 360c50d8ae3SPaolo Bonzini union split_spte { 361c50d8ae3SPaolo Bonzini struct { 362c50d8ae3SPaolo Bonzini u32 spte_low; 363c50d8ae3SPaolo Bonzini u32 spte_high; 364c50d8ae3SPaolo Bonzini }; 365c50d8ae3SPaolo Bonzini u64 spte; 366c50d8ae3SPaolo Bonzini }; 367c50d8ae3SPaolo Bonzini 368c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 369c50d8ae3SPaolo Bonzini { 37057354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 371c50d8ae3SPaolo Bonzini 372c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 373c50d8ae3SPaolo Bonzini return; 374c50d8ae3SPaolo Bonzini 375c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 376c50d8ae3SPaolo Bonzini smp_wmb(); 377c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 378c50d8ae3SPaolo Bonzini } 379c50d8ae3SPaolo Bonzini 380c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 381c50d8ae3SPaolo Bonzini { 382c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 383c50d8ae3SPaolo Bonzini 384c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 385c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 386c50d8ae3SPaolo Bonzini 387c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 388c50d8ae3SPaolo Bonzini 389c50d8ae3SPaolo Bonzini /* 390c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 391c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 392c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 393c50d8ae3SPaolo Bonzini */ 394c50d8ae3SPaolo Bonzini smp_wmb(); 395c50d8ae3SPaolo Bonzini 396c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 397c50d8ae3SPaolo Bonzini } 398c50d8ae3SPaolo Bonzini 399c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 400c50d8ae3SPaolo Bonzini { 401c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 402c50d8ae3SPaolo Bonzini 403c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 404c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 405c50d8ae3SPaolo Bonzini 406c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 407c50d8ae3SPaolo Bonzini 408c50d8ae3SPaolo Bonzini /* 409c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 410c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 411c50d8ae3SPaolo Bonzini */ 412c50d8ae3SPaolo Bonzini smp_wmb(); 413c50d8ae3SPaolo Bonzini 414c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 415c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 416c50d8ae3SPaolo Bonzini } 417c50d8ae3SPaolo Bonzini 418c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 419c50d8ae3SPaolo Bonzini { 420c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 421c50d8ae3SPaolo Bonzini 422c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 423c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 424c50d8ae3SPaolo Bonzini 425c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 426c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 427c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 428c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 429c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 430c50d8ae3SPaolo Bonzini 431c50d8ae3SPaolo Bonzini return orig.spte; 432c50d8ae3SPaolo Bonzini } 433c50d8ae3SPaolo Bonzini 434c50d8ae3SPaolo Bonzini /* 435c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 436c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 437c50d8ae3SPaolo Bonzini * 438aed02fe3SSean Christopherson * An spte tlb flush may be pending, because kvm_set_pte_rmap 439c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 440c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 441c50d8ae3SPaolo Bonzini * 442c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 443c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 444c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 445c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 446c50d8ae3SPaolo Bonzini * 447c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 448c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 449c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 450c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 451c50d8ae3SPaolo Bonzini */ 452c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 453c50d8ae3SPaolo Bonzini { 45457354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 455c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 456c50d8ae3SPaolo Bonzini int count; 457c50d8ae3SPaolo Bonzini 458c50d8ae3SPaolo Bonzini retry: 459c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 460c50d8ae3SPaolo Bonzini smp_rmb(); 461c50d8ae3SPaolo Bonzini 462c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 463c50d8ae3SPaolo Bonzini smp_rmb(); 464c50d8ae3SPaolo Bonzini 465c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 466c50d8ae3SPaolo Bonzini smp_rmb(); 467c50d8ae3SPaolo Bonzini 468c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 469c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 470c50d8ae3SPaolo Bonzini goto retry; 471c50d8ae3SPaolo Bonzini 472c50d8ae3SPaolo Bonzini return spte.spte; 473c50d8ae3SPaolo Bonzini } 474c50d8ae3SPaolo Bonzini #endif 475c50d8ae3SPaolo Bonzini 476c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 477c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 478c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 479c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 480c50d8ae3SPaolo Bonzini * the spte. 481c50d8ae3SPaolo Bonzini */ 482c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 483c50d8ae3SPaolo Bonzini { 48420ba462dSSean Christopherson WARN_ON_ONCE(is_shadow_present_pte(*sptep)); 485c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 486c50d8ae3SPaolo Bonzini } 487c50d8ae3SPaolo Bonzini 488c50d8ae3SPaolo Bonzini /* 489c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 490c50d8ae3SPaolo Bonzini * accessed/dirty status. 491c50d8ae3SPaolo Bonzini */ 492c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 493c50d8ae3SPaolo Bonzini { 494c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 495c50d8ae3SPaolo Bonzini 49620ba462dSSean Christopherson WARN_ON_ONCE(!is_shadow_present_pte(new_spte)); 497115111efSDavid Matlack check_spte_writable_invariants(new_spte); 498c50d8ae3SPaolo Bonzini 499c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 500c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 501c50d8ae3SPaolo Bonzini return old_spte; 502c50d8ae3SPaolo Bonzini } 503c50d8ae3SPaolo Bonzini 504c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 505c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 506c50d8ae3SPaolo Bonzini else 507c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 508c50d8ae3SPaolo Bonzini 50920ba462dSSean Christopherson WARN_ON_ONCE(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 510c50d8ae3SPaolo Bonzini 511c50d8ae3SPaolo Bonzini return old_spte; 512c50d8ae3SPaolo Bonzini } 513c50d8ae3SPaolo Bonzini 514c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 515c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 516c50d8ae3SPaolo Bonzini * 51702844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 51802844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 51902844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 520c50d8ae3SPaolo Bonzini * 521c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 522c50d8ae3SPaolo Bonzini */ 523c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 524c50d8ae3SPaolo Bonzini { 525c50d8ae3SPaolo Bonzini bool flush = false; 526c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 527c50d8ae3SPaolo Bonzini 528c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 529c50d8ae3SPaolo Bonzini return false; 530c50d8ae3SPaolo Bonzini 531c50d8ae3SPaolo Bonzini /* 532c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 533c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 534c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 535c50d8ae3SPaolo Bonzini */ 536706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 537c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 538c50d8ae3SPaolo Bonzini flush = true; 539c50d8ae3SPaolo Bonzini 540c50d8ae3SPaolo Bonzini /* 541c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 542c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 543c50d8ae3SPaolo Bonzini */ 544c50d8ae3SPaolo Bonzini 545c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 546c50d8ae3SPaolo Bonzini flush = true; 547c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 548c50d8ae3SPaolo Bonzini } 549c50d8ae3SPaolo Bonzini 550c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 551c50d8ae3SPaolo Bonzini flush = true; 552c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 553c50d8ae3SPaolo Bonzini } 554c50d8ae3SPaolo Bonzini 555c50d8ae3SPaolo Bonzini return flush; 556c50d8ae3SPaolo Bonzini } 557c50d8ae3SPaolo Bonzini 558c50d8ae3SPaolo Bonzini /* 559c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 560c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 561c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5627fa2a347SSean Christopherson * Returns the old PTE. 563c50d8ae3SPaolo Bonzini */ 56435d539c3SSean Christopherson static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 565c50d8ae3SPaolo Bonzini { 566c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 567c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 56871f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 569b14b2690SSean Christopherson struct page *page; 570c50d8ae3SPaolo Bonzini 57154eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 57254eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 573c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 574c50d8ae3SPaolo Bonzini else 575c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 576c50d8ae3SPaolo Bonzini 577c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5787fa2a347SSean Christopherson return old_spte; 579c50d8ae3SPaolo Bonzini 58071f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 58171f51d2cSMingwei Zhang 582c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 583c50d8ae3SPaolo Bonzini 584c50d8ae3SPaolo Bonzini /* 585b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 586b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 587b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 588b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 589c50d8ae3SPaolo Bonzini */ 590b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 59120ba462dSSean Christopherson WARN_ON_ONCE(page && !page_count(page)); 592c50d8ae3SPaolo Bonzini 593c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 594c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 595c50d8ae3SPaolo Bonzini 596c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 597c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 598c50d8ae3SPaolo Bonzini 5997fa2a347SSean Christopherson return old_spte; 600c50d8ae3SPaolo Bonzini } 601c50d8ae3SPaolo Bonzini 602c50d8ae3SPaolo Bonzini /* 603c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 604c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 605c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 606c50d8ae3SPaolo Bonzini */ 607c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 608c50d8ae3SPaolo Bonzini { 609c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 610c50d8ae3SPaolo Bonzini } 611c50d8ae3SPaolo Bonzini 612c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 613c50d8ae3SPaolo Bonzini { 614c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 615c50d8ae3SPaolo Bonzini } 616c50d8ae3SPaolo Bonzini 617c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 618c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 619c50d8ae3SPaolo Bonzini { 620c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 621c50d8ae3SPaolo Bonzini 622c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 623c50d8ae3SPaolo Bonzini return false; 624c50d8ae3SPaolo Bonzini 625c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 626c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 627c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 628c50d8ae3SPaolo Bonzini } else { 629c50d8ae3SPaolo Bonzini /* 630c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 631c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 632c50d8ae3SPaolo Bonzini */ 633c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 634c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 635c50d8ae3SPaolo Bonzini 636c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 637c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 638c50d8ae3SPaolo Bonzini } 639c50d8ae3SPaolo Bonzini 640c50d8ae3SPaolo Bonzini return true; 641c50d8ae3SPaolo Bonzini } 642c50d8ae3SPaolo Bonzini 64378fdd2f0SSean Christopherson static inline bool is_tdp_mmu_active(struct kvm_vcpu *vcpu) 64478fdd2f0SSean Christopherson { 64578fdd2f0SSean Christopherson return tdp_mmu_enabled && vcpu->arch.mmu->root_role.direct; 64678fdd2f0SSean Christopherson } 64778fdd2f0SSean Christopherson 648c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 649c50d8ae3SPaolo Bonzini { 65078fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 651c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 652c5c8c7c5SDavid Matlack } else { 653c50d8ae3SPaolo Bonzini /* 654c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 655c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 656c50d8ae3SPaolo Bonzini */ 657c50d8ae3SPaolo Bonzini local_irq_disable(); 658c50d8ae3SPaolo Bonzini 659c50d8ae3SPaolo Bonzini /* 660c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 661c50d8ae3SPaolo Bonzini * to vcpu->mode. 662c50d8ae3SPaolo Bonzini */ 663c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 664c50d8ae3SPaolo Bonzini } 665c5c8c7c5SDavid Matlack } 666c50d8ae3SPaolo Bonzini 667c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 668c50d8ae3SPaolo Bonzini { 66978fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 670c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 671c5c8c7c5SDavid Matlack } else { 672c50d8ae3SPaolo Bonzini /* 673c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 674c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 675c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 676c50d8ae3SPaolo Bonzini */ 677c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 678c50d8ae3SPaolo Bonzini local_irq_enable(); 679c50d8ae3SPaolo Bonzini } 680c5c8c7c5SDavid Matlack } 681c50d8ae3SPaolo Bonzini 682378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 683c50d8ae3SPaolo Bonzini { 684c50d8ae3SPaolo Bonzini int r; 685c50d8ae3SPaolo Bonzini 686531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 68794ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 688531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 689c50d8ae3SPaolo Bonzini if (r) 690c50d8ae3SPaolo Bonzini return r; 69194ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 692171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 693171a90d7SSean Christopherson if (r) 694171a90d7SSean Christopherson return r; 695378f5cd6SSean Christopherson if (maybe_indirect) { 6966a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 697171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 698c50d8ae3SPaolo Bonzini if (r) 699c50d8ae3SPaolo Bonzini return r; 700378f5cd6SSean Christopherson } 70194ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 702531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 703c50d8ae3SPaolo Bonzini } 704c50d8ae3SPaolo Bonzini 705c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 706c50d8ae3SPaolo Bonzini { 70794ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 70894ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 7096a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 71094ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 711c50d8ae3SPaolo Bonzini } 712c50d8ae3SPaolo Bonzini 713c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 714c50d8ae3SPaolo Bonzini { 715c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 716c50d8ae3SPaolo Bonzini } 717c50d8ae3SPaolo Bonzini 7186a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 7196a97575dSDavid Matlack 720c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 721c50d8ae3SPaolo Bonzini { 72284e5ffd0SLai Jiangshan if (sp->role.passthrough) 72384e5ffd0SLai Jiangshan return sp->gfn; 72484e5ffd0SLai Jiangshan 725c50d8ae3SPaolo Bonzini if (!sp->role.direct) 7266a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 727c50d8ae3SPaolo Bonzini 7282ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 729c50d8ae3SPaolo Bonzini } 730c50d8ae3SPaolo Bonzini 7316a97575dSDavid Matlack /* 7326a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 7336a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 7346a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 7356a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 7366a97575dSDavid Matlack */ 7376a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 738c50d8ae3SPaolo Bonzini { 7396a97575dSDavid Matlack if (sp_has_gptes(sp)) 7406a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7416a97575dSDavid Matlack 7426a97575dSDavid Matlack /* 7436a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7446a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7456a97575dSDavid Matlack * permissions" are just ACC_ALL. 7466a97575dSDavid Matlack * 7476a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7486a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7496a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7506a97575dSDavid Matlack * page. 7516a97575dSDavid Matlack * 7526a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7536a97575dSDavid Matlack */ 7546a97575dSDavid Matlack return sp->role.access; 7556a97575dSDavid Matlack } 7566a97575dSDavid Matlack 75772ae5822SSean Christopherson static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, 75872ae5822SSean Christopherson gfn_t gfn, unsigned int access) 7596a97575dSDavid Matlack { 7606a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7616a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 76284e5ffd0SLai Jiangshan return; 76384e5ffd0SLai Jiangshan } 76484e5ffd0SLai Jiangshan 7656a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7666a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7676a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7686a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7696a97575dSDavid Matlack 7706a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7716a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7726a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7736a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 774c50d8ae3SPaolo Bonzini } 775c50d8ae3SPaolo Bonzini 77672ae5822SSean Christopherson static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, 77772ae5822SSean Christopherson unsigned int access) 7786a97575dSDavid Matlack { 7796a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7806a97575dSDavid Matlack 7816a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 782c50d8ae3SPaolo Bonzini } 783c50d8ae3SPaolo Bonzini 784c50d8ae3SPaolo Bonzini /* 785c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 786c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 787c50d8ae3SPaolo Bonzini */ 788c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7898ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 790c50d8ae3SPaolo Bonzini { 791c50d8ae3SPaolo Bonzini unsigned long idx; 792c50d8ae3SPaolo Bonzini 793c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 794c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 795c50d8ae3SPaolo Bonzini } 796c50d8ae3SPaolo Bonzini 797269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 798c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 799c50d8ae3SPaolo Bonzini { 800c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 801c50d8ae3SPaolo Bonzini int i; 802c50d8ae3SPaolo Bonzini 8033bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 804c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 805c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 80620ba462dSSean Christopherson WARN_ON_ONCE(linfo->disallow_lpage < 0); 807c50d8ae3SPaolo Bonzini } 808c50d8ae3SPaolo Bonzini } 809c50d8ae3SPaolo Bonzini 810269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 811c50d8ae3SPaolo Bonzini { 812c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 813c50d8ae3SPaolo Bonzini } 814c50d8ae3SPaolo Bonzini 815269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 816c50d8ae3SPaolo Bonzini { 817c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 818c50d8ae3SPaolo Bonzini } 819c50d8ae3SPaolo Bonzini 820c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 821c50d8ae3SPaolo Bonzini { 822c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 823c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 824c50d8ae3SPaolo Bonzini gfn_t gfn; 825c50d8ae3SPaolo Bonzini 826c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 827c50d8ae3SPaolo Bonzini gfn = sp->gfn; 828c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 829c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 830c50d8ae3SPaolo Bonzini 831c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8323bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 833c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 834c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 835c50d8ae3SPaolo Bonzini 836c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 837be911771SDavid Matlack 838be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 8394ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, PG_LEVEL_4K); 840c50d8ae3SPaolo Bonzini } 841c50d8ae3SPaolo Bonzini 84261f94478SSean Christopherson void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 843c50d8ae3SPaolo Bonzini { 844428e9216SSean Christopherson /* 845428e9216SSean Christopherson * If it's possible to replace the shadow page with an NX huge page, 846428e9216SSean Christopherson * i.e. if the shadow page is the only thing currently preventing KVM 847428e9216SSean Christopherson * from using a huge page, add the shadow page to the list of "to be 848428e9216SSean Christopherson * zapped for NX recovery" pages. Note, the shadow page can already be 849428e9216SSean Christopherson * on the list if KVM is reusing an existing shadow page, i.e. if KVM 850428e9216SSean Christopherson * links a shadow page at multiple points. 851428e9216SSean Christopherson */ 85261f94478SSean Christopherson if (!list_empty(&sp->possible_nx_huge_page_link)) 853c50d8ae3SPaolo Bonzini return; 854c50d8ae3SPaolo Bonzini 855c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 85655c510e2SSean Christopherson list_add_tail(&sp->possible_nx_huge_page_link, 85755c510e2SSean Christopherson &kvm->arch.possible_nx_huge_pages); 858c50d8ae3SPaolo Bonzini } 859c50d8ae3SPaolo Bonzini 86061f94478SSean Christopherson static void account_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp, 86161f94478SSean Christopherson bool nx_huge_page_possible) 86261f94478SSean Christopherson { 86361f94478SSean Christopherson sp->nx_huge_page_disallowed = true; 86461f94478SSean Christopherson 86561f94478SSean Christopherson if (nx_huge_page_possible) 86661f94478SSean Christopherson track_possible_nx_huge_page(kvm, sp); 867c50d8ae3SPaolo Bonzini } 868c50d8ae3SPaolo Bonzini 869c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 870c50d8ae3SPaolo Bonzini { 871c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 872c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 873c50d8ae3SPaolo Bonzini gfn_t gfn; 874c50d8ae3SPaolo Bonzini 875c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 876c50d8ae3SPaolo Bonzini gfn = sp->gfn; 877c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 878c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8793bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 880c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 881c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 882c50d8ae3SPaolo Bonzini 883c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 884c50d8ae3SPaolo Bonzini } 885c50d8ae3SPaolo Bonzini 88661f94478SSean Christopherson void untrack_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 887c50d8ae3SPaolo Bonzini { 88855c510e2SSean Christopherson if (list_empty(&sp->possible_nx_huge_page_link)) 889428e9216SSean Christopherson return; 890428e9216SSean Christopherson 891c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 89255c510e2SSean Christopherson list_del_init(&sp->possible_nx_huge_page_link); 893c50d8ae3SPaolo Bonzini } 894c50d8ae3SPaolo Bonzini 89561f94478SSean Christopherson static void unaccount_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 89661f94478SSean Christopherson { 89761f94478SSean Christopherson sp->nx_huge_page_disallowed = false; 89861f94478SSean Christopherson 89961f94478SSean Christopherson untrack_possible_nx_huge_page(kvm, sp); 900c50d8ae3SPaolo Bonzini } 901c50d8ae3SPaolo Bonzini 902f3d90f90SSean Christopherson static struct kvm_memory_slot *gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, 903f3d90f90SSean Christopherson gfn_t gfn, 904c50d8ae3SPaolo Bonzini bool no_dirty_log) 905c50d8ae3SPaolo Bonzini { 906c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 907c50d8ae3SPaolo Bonzini 908c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 90991b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 91091b0d268SPaolo Bonzini return NULL; 911044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 91291b0d268SPaolo Bonzini return NULL; 913c50d8ae3SPaolo Bonzini 914c50d8ae3SPaolo Bonzini return slot; 915c50d8ae3SPaolo Bonzini } 916c50d8ae3SPaolo Bonzini 917c50d8ae3SPaolo Bonzini /* 918c50d8ae3SPaolo Bonzini * About rmap_head encoding: 919c50d8ae3SPaolo Bonzini * 920c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 921c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 922c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 923c50d8ae3SPaolo Bonzini */ 924c50d8ae3SPaolo Bonzini 925c50d8ae3SPaolo Bonzini /* 926c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 927c50d8ae3SPaolo Bonzini */ 9282ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 929c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 930c50d8ae3SPaolo Bonzini { 931c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 93213236e25SPeter Xu int count = 0; 933c50d8ae3SPaolo Bonzini 934c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 935c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 936c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 9372ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 938c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 939c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 94013236e25SPeter Xu desc->spte_count = 2; 941141705b7SLai Jiangshan desc->tail_count = 0; 942c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 943c50d8ae3SPaolo Bonzini ++count; 944c50d8ae3SPaolo Bonzini } else { 945c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 946141705b7SLai Jiangshan count = desc->tail_count + desc->spte_count; 947141705b7SLai Jiangshan 948141705b7SLai Jiangshan /* 949141705b7SLai Jiangshan * If the previous head is full, allocate a new head descriptor 950141705b7SLai Jiangshan * as tail descriptors are always kept full. 951141705b7SLai Jiangshan */ 952141705b7SLai Jiangshan if (desc->spte_count == PTE_LIST_EXT) { 953141705b7SLai Jiangshan desc = kvm_mmu_memory_cache_alloc(cache); 954141705b7SLai Jiangshan desc->more = (struct pte_list_desc *)(rmap_head->val & ~1ul); 95513236e25SPeter Xu desc->spte_count = 0; 956141705b7SLai Jiangshan desc->tail_count = count; 957141705b7SLai Jiangshan rmap_head->val = (unsigned long)desc | 1; 958c6c4f961SLi RongQing } 95913236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 960c50d8ae3SPaolo Bonzini } 961c50d8ae3SPaolo Bonzini return count; 962c50d8ae3SPaolo Bonzini } 963c50d8ae3SPaolo Bonzini 964069f30c6SMingwei Zhang static void pte_list_desc_remove_entry(struct kvm *kvm, 965069f30c6SMingwei Zhang struct kvm_rmap_head *rmap_head, 966141705b7SLai Jiangshan struct pte_list_desc *desc, int i) 967c50d8ae3SPaolo Bonzini { 968141705b7SLai Jiangshan struct pte_list_desc *head_desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 969141705b7SLai Jiangshan int j = head_desc->spte_count - 1; 970c50d8ae3SPaolo Bonzini 971141705b7SLai Jiangshan /* 972141705b7SLai Jiangshan * The head descriptor should never be empty. A new head is added only 973141705b7SLai Jiangshan * when adding an entry and the previous head is full, and heads are 974141705b7SLai Jiangshan * removed (this flow) when they become empty. 975141705b7SLai Jiangshan */ 97652e322edSSean Christopherson KVM_BUG_ON_DATA_CORRUPTION(j < 0, kvm); 977141705b7SLai Jiangshan 978141705b7SLai Jiangshan /* 979141705b7SLai Jiangshan * Replace the to-be-freed SPTE with the last valid entry from the head 980141705b7SLai Jiangshan * descriptor to ensure that tail descriptors are full at all times. 981141705b7SLai Jiangshan * Note, this also means that tail_count is stable for each descriptor. 982141705b7SLai Jiangshan */ 983141705b7SLai Jiangshan desc->sptes[i] = head_desc->sptes[j]; 984141705b7SLai Jiangshan head_desc->sptes[j] = NULL; 985141705b7SLai Jiangshan head_desc->spte_count--; 986141705b7SLai Jiangshan if (head_desc->spte_count) 987c50d8ae3SPaolo Bonzini return; 988141705b7SLai Jiangshan 989141705b7SLai Jiangshan /* 990141705b7SLai Jiangshan * The head descriptor is empty. If there are no tail descriptors, 991141705b7SLai Jiangshan * nullify the rmap head to mark the list as emtpy, else point the rmap 992141705b7SLai Jiangshan * head at the next descriptor, i.e. the new head. 993141705b7SLai Jiangshan */ 994141705b7SLai Jiangshan if (!head_desc->more) 995fe3c2b4cSMiaohe Lin rmap_head->val = 0; 996c50d8ae3SPaolo Bonzini else 997141705b7SLai Jiangshan rmap_head->val = (unsigned long)head_desc->more | 1; 998141705b7SLai Jiangshan mmu_free_pte_list_desc(head_desc); 999c50d8ae3SPaolo Bonzini } 1000c50d8ae3SPaolo Bonzini 1001069f30c6SMingwei Zhang static void pte_list_remove(struct kvm *kvm, u64 *spte, 1002069f30c6SMingwei Zhang struct kvm_rmap_head *rmap_head) 1003c50d8ae3SPaolo Bonzini { 1004c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 1005c50d8ae3SPaolo Bonzini int i; 1006c50d8ae3SPaolo Bonzini 100752e322edSSean Christopherson if (KVM_BUG_ON_DATA_CORRUPTION(!rmap_head->val, kvm)) 100852e322edSSean Christopherson return; 100952e322edSSean Christopherson 101052e322edSSean Christopherson if (!(rmap_head->val & 1)) { 101152e322edSSean Christopherson if (KVM_BUG_ON_DATA_CORRUPTION((u64 *)rmap_head->val != spte, kvm)) 101252e322edSSean Christopherson return; 101352e322edSSean Christopherson 1014c50d8ae3SPaolo Bonzini rmap_head->val = 0; 1015c50d8ae3SPaolo Bonzini } else { 1016c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1017c50d8ae3SPaolo Bonzini while (desc) { 101813236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 1019c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 1020069f30c6SMingwei Zhang pte_list_desc_remove_entry(kvm, rmap_head, 1021069f30c6SMingwei Zhang desc, i); 1022c50d8ae3SPaolo Bonzini return; 1023c50d8ae3SPaolo Bonzini } 1024c50d8ae3SPaolo Bonzini } 1025c50d8ae3SPaolo Bonzini desc = desc->more; 1026c50d8ae3SPaolo Bonzini } 102752e322edSSean Christopherson 102852e322edSSean Christopherson KVM_BUG_ON_DATA_CORRUPTION(true, kvm); 1029c50d8ae3SPaolo Bonzini } 1030c50d8ae3SPaolo Bonzini } 1031c50d8ae3SPaolo Bonzini 10329202aee8SSean Christopherson static void kvm_zap_one_rmap_spte(struct kvm *kvm, 10339202aee8SSean Christopherson struct kvm_rmap_head *rmap_head, u64 *sptep) 1034c50d8ae3SPaolo Bonzini { 103571f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1036069f30c6SMingwei Zhang pte_list_remove(kvm, sptep, rmap_head); 1037c50d8ae3SPaolo Bonzini } 1038c50d8ae3SPaolo Bonzini 10399202aee8SSean Christopherson /* Return true if at least one SPTE was zapped, false otherwise */ 10409202aee8SSean Christopherson static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 10419202aee8SSean Christopherson struct kvm_rmap_head *rmap_head) 1042a75b5404SPeter Xu { 1043a75b5404SPeter Xu struct pte_list_desc *desc, *next; 1044a75b5404SPeter Xu int i; 1045a75b5404SPeter Xu 1046a75b5404SPeter Xu if (!rmap_head->val) 1047a75b5404SPeter Xu return false; 1048a75b5404SPeter Xu 1049a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 105071f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 1051a75b5404SPeter Xu goto out; 1052a75b5404SPeter Xu } 1053a75b5404SPeter Xu 1054a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1055a75b5404SPeter Xu 1056a75b5404SPeter Xu for (; desc; desc = next) { 1057a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 105871f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 1059a75b5404SPeter Xu next = desc->more; 1060a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 1061a75b5404SPeter Xu } 1062a75b5404SPeter Xu out: 1063a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 1064a75b5404SPeter Xu rmap_head->val = 0; 1065a75b5404SPeter Xu return true; 1066a75b5404SPeter Xu } 1067a75b5404SPeter Xu 10683bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10693bcd0662SPeter Xu { 10703bcd0662SPeter Xu struct pte_list_desc *desc; 10713bcd0662SPeter Xu 10723bcd0662SPeter Xu if (!rmap_head->val) 10733bcd0662SPeter Xu return 0; 10743bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10753bcd0662SPeter Xu return 1; 10763bcd0662SPeter Xu 10773bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1078141705b7SLai Jiangshan return desc->tail_count + desc->spte_count; 10793bcd0662SPeter Xu } 10803bcd0662SPeter Xu 108193e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1082269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1083c50d8ae3SPaolo Bonzini { 1084c50d8ae3SPaolo Bonzini unsigned long idx; 1085c50d8ae3SPaolo Bonzini 1086c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 10873bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1088c50d8ae3SPaolo Bonzini } 1089c50d8ae3SPaolo Bonzini 1090c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1091c50d8ae3SPaolo Bonzini { 1092601f8af0SDavid Matlack struct kvm_memslots *slots; 1093601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1094c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1095c50d8ae3SPaolo Bonzini gfn_t gfn; 1096c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1097c50d8ae3SPaolo Bonzini 109857354682SSean Christopherson sp = sptep_to_sp(spte); 109979e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(spte)); 1100601f8af0SDavid Matlack 1101601f8af0SDavid Matlack /* 110268be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 110368be1306SDavid Matlack * so we have to determine which memslots to use based on context 110468be1306SDavid Matlack * information in sp->role. 1105601f8af0SDavid Matlack */ 1106601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1107601f8af0SDavid Matlack 1108601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 110993e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1110601f8af0SDavid Matlack 1111069f30c6SMingwei Zhang pte_list_remove(kvm, spte, rmap_head); 1112c50d8ae3SPaolo Bonzini } 1113c50d8ae3SPaolo Bonzini 1114c50d8ae3SPaolo Bonzini /* 1115c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1116c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1117c50d8ae3SPaolo Bonzini */ 1118c50d8ae3SPaolo Bonzini struct rmap_iterator { 1119c50d8ae3SPaolo Bonzini /* private fields */ 1120c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1121c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1122c50d8ae3SPaolo Bonzini }; 1123c50d8ae3SPaolo Bonzini 1124c50d8ae3SPaolo Bonzini /* 1125c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1126c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 11270a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1128c50d8ae3SPaolo Bonzini * 1129c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1130c50d8ae3SPaolo Bonzini */ 1131c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1132c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1133c50d8ae3SPaolo Bonzini { 1134c50d8ae3SPaolo Bonzini u64 *sptep; 1135c50d8ae3SPaolo Bonzini 1136c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1137c50d8ae3SPaolo Bonzini return NULL; 1138c50d8ae3SPaolo Bonzini 1139c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1140c50d8ae3SPaolo Bonzini iter->desc = NULL; 1141c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1142c50d8ae3SPaolo Bonzini goto out; 1143c50d8ae3SPaolo Bonzini } 1144c50d8ae3SPaolo Bonzini 1145c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1146c50d8ae3SPaolo Bonzini iter->pos = 0; 1147c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1148c50d8ae3SPaolo Bonzini out: 1149c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1150c50d8ae3SPaolo Bonzini return sptep; 1151c50d8ae3SPaolo Bonzini } 1152c50d8ae3SPaolo Bonzini 1153c50d8ae3SPaolo Bonzini /* 1154c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1155c50d8ae3SPaolo Bonzini * 1156c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1157c50d8ae3SPaolo Bonzini */ 1158c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1159c50d8ae3SPaolo Bonzini { 1160c50d8ae3SPaolo Bonzini u64 *sptep; 1161c50d8ae3SPaolo Bonzini 1162c50d8ae3SPaolo Bonzini if (iter->desc) { 1163c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1164c50d8ae3SPaolo Bonzini ++iter->pos; 1165c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1166c50d8ae3SPaolo Bonzini if (sptep) 1167c50d8ae3SPaolo Bonzini goto out; 1168c50d8ae3SPaolo Bonzini } 1169c50d8ae3SPaolo Bonzini 1170c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1171c50d8ae3SPaolo Bonzini 1172c50d8ae3SPaolo Bonzini if (iter->desc) { 1173c50d8ae3SPaolo Bonzini iter->pos = 0; 1174c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1175c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1176c50d8ae3SPaolo Bonzini goto out; 1177c50d8ae3SPaolo Bonzini } 1178c50d8ae3SPaolo Bonzini } 1179c50d8ae3SPaolo Bonzini 1180c50d8ae3SPaolo Bonzini return NULL; 1181c50d8ae3SPaolo Bonzini out: 1182c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1183c50d8ae3SPaolo Bonzini return sptep; 1184c50d8ae3SPaolo Bonzini } 1185c50d8ae3SPaolo Bonzini 1186c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1187c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1188c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1189c50d8ae3SPaolo Bonzini 1190c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1191c50d8ae3SPaolo Bonzini { 119271f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 11937fa2a347SSean Christopherson 11947fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1195c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1196c50d8ae3SPaolo Bonzini } 1197c50d8ae3SPaolo Bonzini 119803787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1199c50d8ae3SPaolo Bonzini { 12000cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 12010cd8dc73SPaolo Bonzini 12020cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 120320ba462dSSean Christopherson WARN_ON_ONCE(sp->role.level == PG_LEVEL_4K); 12040cd8dc73SPaolo Bonzini 1205c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 120603787394SPaolo Bonzini 120703787394SPaolo Bonzini if (flush) 12081b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 1209c50d8ae3SPaolo Bonzini } 1210c50d8ae3SPaolo Bonzini 1211c50d8ae3SPaolo Bonzini /* 1212c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1213c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1214c50d8ae3SPaolo Bonzini * 1215c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1216c50d8ae3SPaolo Bonzini * protection: 1217c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1218c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1219c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1220c50d8ae3SPaolo Bonzini * shadow page. 1221c50d8ae3SPaolo Bonzini * 1222c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1223c50d8ae3SPaolo Bonzini */ 1224c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1225c50d8ae3SPaolo Bonzini { 1226c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1227c50d8ae3SPaolo Bonzini 1228c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1229706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1230c50d8ae3SPaolo Bonzini return false; 1231c50d8ae3SPaolo Bonzini 1232c50d8ae3SPaolo Bonzini if (pt_protect) 12335fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1234c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1235c50d8ae3SPaolo Bonzini 1236c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1237c50d8ae3SPaolo Bonzini } 1238c50d8ae3SPaolo Bonzini 12391346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1240c50d8ae3SPaolo Bonzini bool pt_protect) 1241c50d8ae3SPaolo Bonzini { 1242c50d8ae3SPaolo Bonzini u64 *sptep; 1243c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1244c50d8ae3SPaolo Bonzini bool flush = false; 1245c50d8ae3SPaolo Bonzini 1246c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1247c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1248c50d8ae3SPaolo Bonzini 1249c50d8ae3SPaolo Bonzini return flush; 1250c50d8ae3SPaolo Bonzini } 1251c50d8ae3SPaolo Bonzini 1252c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1253c50d8ae3SPaolo Bonzini { 1254c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1255c50d8ae3SPaolo Bonzini 12560fe6370eSSean Christopherson KVM_MMU_WARN_ON(!spte_ad_enabled(spte)); 1257c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1258c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1259c50d8ae3SPaolo Bonzini } 1260c50d8ae3SPaolo Bonzini 1261c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1262c50d8ae3SPaolo Bonzini { 1263c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1264c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1265c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1266c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1267c50d8ae3SPaolo Bonzini 1268c50d8ae3SPaolo Bonzini return was_writable; 1269c50d8ae3SPaolo Bonzini } 1270c50d8ae3SPaolo Bonzini 1271c50d8ae3SPaolo Bonzini /* 1272c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1273c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1274c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1275c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1276c50d8ae3SPaolo Bonzini */ 12770a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1278269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1279c50d8ae3SPaolo Bonzini { 1280c50d8ae3SPaolo Bonzini u64 *sptep; 1281c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1282c50d8ae3SPaolo Bonzini bool flush = false; 1283c50d8ae3SPaolo Bonzini 1284c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1285c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1286c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1287c50d8ae3SPaolo Bonzini else 1288c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1289c50d8ae3SPaolo Bonzini 1290c50d8ae3SPaolo Bonzini return flush; 1291c50d8ae3SPaolo Bonzini } 1292c50d8ae3SPaolo Bonzini 1293c50d8ae3SPaolo Bonzini /** 1294c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1295c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1296c50d8ae3SPaolo Bonzini * @slot: slot to protect 1297c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1298c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1299c50d8ae3SPaolo Bonzini * 130089212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1301c50d8ae3SPaolo Bonzini */ 1302c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1303c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1304c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1305c50d8ae3SPaolo Bonzini { 1306c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1307c50d8ae3SPaolo Bonzini 13081f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1309a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1310a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1311e2209710SBen Gardon 1312e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1313e2209710SBen Gardon return; 1314e2209710SBen Gardon 1315c50d8ae3SPaolo Bonzini while (mask) { 131693e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13173bae0459SSean Christopherson PG_LEVEL_4K, slot); 13181346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1319c50d8ae3SPaolo Bonzini 1320c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1321c50d8ae3SPaolo Bonzini mask &= mask - 1; 1322c50d8ae3SPaolo Bonzini } 1323c50d8ae3SPaolo Bonzini } 1324c50d8ae3SPaolo Bonzini 1325c50d8ae3SPaolo Bonzini /** 1326c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1327c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1328c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1329c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1330c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1331c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1332c50d8ae3SPaolo Bonzini * 1333c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1334c50d8ae3SPaolo Bonzini */ 1335a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1336c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1337c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1338c50d8ae3SPaolo Bonzini { 1339c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1340c50d8ae3SPaolo Bonzini 13411f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1342a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1343a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1344e2209710SBen Gardon 1345e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1346e2209710SBen Gardon return; 1347e2209710SBen Gardon 1348c50d8ae3SPaolo Bonzini while (mask) { 134993e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13503bae0459SSean Christopherson PG_LEVEL_4K, slot); 13510a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1352c50d8ae3SPaolo Bonzini 1353c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1354c50d8ae3SPaolo Bonzini mask &= mask - 1; 1355c50d8ae3SPaolo Bonzini } 1356c50d8ae3SPaolo Bonzini } 1357c50d8ae3SPaolo Bonzini 1358c50d8ae3SPaolo Bonzini /** 1359c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1360c50d8ae3SPaolo Bonzini * PT level pages. 1361c50d8ae3SPaolo Bonzini * 1362c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1363c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1364c50d8ae3SPaolo Bonzini * 136589212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 136689212919SKeqian Zhu * have such mappings. 1367c50d8ae3SPaolo Bonzini */ 1368c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1369c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1370c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1371c50d8ae3SPaolo Bonzini { 137289212919SKeqian Zhu /* 137389212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 137489212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 137589212919SKeqian Zhu * are split to 4K on the first write. 137689212919SKeqian Zhu * 137789212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 137889212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 137989212919SKeqian Zhu * pages. 138089212919SKeqian Zhu */ 138189212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 138289212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 138389212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 138489212919SKeqian Zhu 1385cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1386cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1387cb00a70bSDavid Matlack 138889212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 138989212919SKeqian Zhu 139089212919SKeqian Zhu /* Cross two large pages? */ 139189212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 139289212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 139389212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 139489212919SKeqian Zhu PG_LEVEL_2M); 139589212919SKeqian Zhu } 139689212919SKeqian Zhu 139789212919SKeqian Zhu /* Now handle 4K PTEs. */ 1398a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1399a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1400c50d8ae3SPaolo Bonzini else 1401c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1402c50d8ae3SPaolo Bonzini } 1403c50d8ae3SPaolo Bonzini 1404fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1405fb04a1edSPeter Xu { 14066dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1407fb04a1edSPeter Xu } 1408fb04a1edSPeter Xu 1409c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 14103ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 14113ad93562SKeqian Zhu int min_level) 1412c50d8ae3SPaolo Bonzini { 1413c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1414c50d8ae3SPaolo Bonzini int i; 1415c50d8ae3SPaolo Bonzini bool write_protected = false; 1416c50d8ae3SPaolo Bonzini 1417e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 14183ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 141993e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 14201346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1421c50d8ae3SPaolo Bonzini } 1422e2209710SBen Gardon } 1423c50d8ae3SPaolo Bonzini 14241f98f2bdSDavid Matlack if (tdp_mmu_enabled) 142546044f72SBen Gardon write_protected |= 14263ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 142746044f72SBen Gardon 1428c50d8ae3SPaolo Bonzini return write_protected; 1429c50d8ae3SPaolo Bonzini } 1430c50d8ae3SPaolo Bonzini 1431cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1432c50d8ae3SPaolo Bonzini { 1433c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1434c50d8ae3SPaolo Bonzini 1435c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 14363ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1437c50d8ae3SPaolo Bonzini } 1438c50d8ae3SPaolo Bonzini 1439f8480721SSean Christopherson static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1440269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1441c50d8ae3SPaolo Bonzini { 14429202aee8SSean Christopherson return kvm_zap_all_rmap_sptes(kvm, rmap_head); 1443c50d8ae3SPaolo Bonzini } 1444c50d8ae3SPaolo Bonzini 1445f8480721SSean Christopherson static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1446c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14473039bcc7SSean Christopherson pte_t unused) 1448c50d8ae3SPaolo Bonzini { 1449f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1450c50d8ae3SPaolo Bonzini } 1451c50d8ae3SPaolo Bonzini 1452aed02fe3SSean Christopherson static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1453c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14543039bcc7SSean Christopherson pte_t pte) 1455c50d8ae3SPaolo Bonzini { 1456c50d8ae3SPaolo Bonzini u64 *sptep; 1457c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 145898a26b69SVihas Mak bool need_flush = false; 1459c50d8ae3SPaolo Bonzini u64 new_spte; 1460c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1461c50d8ae3SPaolo Bonzini 146220ba462dSSean Christopherson WARN_ON_ONCE(pte_huge(pte)); 14633039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1464c50d8ae3SPaolo Bonzini 1465c50d8ae3SPaolo Bonzini restart: 1466c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 146798a26b69SVihas Mak need_flush = true; 1468c50d8ae3SPaolo Bonzini 14693039bcc7SSean Christopherson if (pte_write(pte)) { 14709202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 1471c50d8ae3SPaolo Bonzini goto restart; 1472c50d8ae3SPaolo Bonzini } else { 1473cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1474cb3eedabSPaolo Bonzini *sptep, new_pfn); 1475c50d8ae3SPaolo Bonzini 147671f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1477c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1478c50d8ae3SPaolo Bonzini } 1479c50d8ae3SPaolo Bonzini } 1480c50d8ae3SPaolo Bonzini 14818a1300ffSSean Christopherson if (need_flush && kvm_available_flush_remote_tlbs_range()) { 14829ffe9265SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, level); 148398a26b69SVihas Mak return false; 1484c50d8ae3SPaolo Bonzini } 1485c50d8ae3SPaolo Bonzini 1486c50d8ae3SPaolo Bonzini return need_flush; 1487c50d8ae3SPaolo Bonzini } 1488c50d8ae3SPaolo Bonzini 1489c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1490c50d8ae3SPaolo Bonzini /* input fields. */ 1491269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1492c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1493c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1494c50d8ae3SPaolo Bonzini int start_level; 1495c50d8ae3SPaolo Bonzini int end_level; 1496c50d8ae3SPaolo Bonzini 1497c50d8ae3SPaolo Bonzini /* output fields. */ 1498c50d8ae3SPaolo Bonzini gfn_t gfn; 1499c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1500c50d8ae3SPaolo Bonzini int level; 1501c50d8ae3SPaolo Bonzini 1502c50d8ae3SPaolo Bonzini /* private field. */ 1503c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1504c50d8ae3SPaolo Bonzini }; 1505c50d8ae3SPaolo Bonzini 1506f3d90f90SSean Christopherson static void rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, 1507f3d90f90SSean Christopherson int level) 1508c50d8ae3SPaolo Bonzini { 1509c50d8ae3SPaolo Bonzini iterator->level = level; 1510c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 151193e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 151293e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1513c50d8ae3SPaolo Bonzini } 1514c50d8ae3SPaolo Bonzini 1515f3d90f90SSean Christopherson static void slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1516f3d90f90SSean Christopherson const struct kvm_memory_slot *slot, 1517f3d90f90SSean Christopherson int start_level, int end_level, 1518f3d90f90SSean Christopherson gfn_t start_gfn, gfn_t end_gfn) 1519c50d8ae3SPaolo Bonzini { 1520c50d8ae3SPaolo Bonzini iterator->slot = slot; 1521c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1522c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1523c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1524c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1525c50d8ae3SPaolo Bonzini 1526c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1527c50d8ae3SPaolo Bonzini } 1528c50d8ae3SPaolo Bonzini 1529c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1530c50d8ae3SPaolo Bonzini { 1531c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1532c50d8ae3SPaolo Bonzini } 1533c50d8ae3SPaolo Bonzini 1534c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1535c50d8ae3SPaolo Bonzini { 15366ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1537c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 15386ba1e04fSVipin Sharma 15396ba1e04fSVipin Sharma if (iterator->rmap->val) 1540c50d8ae3SPaolo Bonzini return; 1541c50d8ae3SPaolo Bonzini } 1542c50d8ae3SPaolo Bonzini 1543c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1544c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1545c50d8ae3SPaolo Bonzini return; 1546c50d8ae3SPaolo Bonzini } 1547c50d8ae3SPaolo Bonzini 1548c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1549c50d8ae3SPaolo Bonzini } 1550c50d8ae3SPaolo Bonzini 1551c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1552c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1553c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1554c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1555c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1556c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1557c50d8ae3SPaolo Bonzini 15583039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1559c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15603039bcc7SSean Christopherson int level, pte_t pte); 1561c1b91493SSean Christopherson 15623039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15633039bcc7SSean Christopherson struct kvm_gfn_range *range, 1564c1b91493SSean Christopherson rmap_handler_t handler) 1565c50d8ae3SPaolo Bonzini { 1566c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15673039bcc7SSean Christopherson bool ret = false; 1568c50d8ae3SPaolo Bonzini 15693039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15703039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15713039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15723e1efe2bSSean Christopherson iterator.level, range->arg.pte); 1573c50d8ae3SPaolo Bonzini 1574c50d8ae3SPaolo Bonzini return ret; 1575c50d8ae3SPaolo Bonzini } 1576c50d8ae3SPaolo Bonzini 15773039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1578c50d8ae3SPaolo Bonzini { 1579e2209710SBen Gardon bool flush = false; 1580c50d8ae3SPaolo Bonzini 1581e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1582f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1583063afacdSBen Gardon 15841f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1585c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1586063afacdSBen Gardon 15870a3869e1SSean Christopherson if (kvm_x86_ops.set_apic_access_page_addr && 15880a3869e1SSean Christopherson range->slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT) 15890a8a5f2cSSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); 15900a8a5f2cSSean Christopherson 15913039bcc7SSean Christopherson return flush; 1592c50d8ae3SPaolo Bonzini } 1593c50d8ae3SPaolo Bonzini 15943039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1595c50d8ae3SPaolo Bonzini { 1596e2209710SBen Gardon bool flush = false; 15971d8dd6b3SBen Gardon 1598e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1599aed02fe3SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); 16001d8dd6b3SBen Gardon 16011f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16023039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 16031d8dd6b3SBen Gardon 16043039bcc7SSean Christopherson return flush; 1605c50d8ae3SPaolo Bonzini } 1606c50d8ae3SPaolo Bonzini 1607aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1608c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 16093039bcc7SSean Christopherson pte_t unused) 1610c50d8ae3SPaolo Bonzini { 1611c50d8ae3SPaolo Bonzini u64 *sptep; 16123f649ab7SKees Cook struct rmap_iterator iter; 1613c50d8ae3SPaolo Bonzini int young = 0; 1614c50d8ae3SPaolo Bonzini 1615c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1616c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1617c50d8ae3SPaolo Bonzini 1618c50d8ae3SPaolo Bonzini return young; 1619c50d8ae3SPaolo Bonzini } 1620c50d8ae3SPaolo Bonzini 1621aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1622c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 16233039bcc7SSean Christopherson int level, pte_t unused) 1624c50d8ae3SPaolo Bonzini { 1625c50d8ae3SPaolo Bonzini u64 *sptep; 1626c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1627c50d8ae3SPaolo Bonzini 1628c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1629c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 163098a26b69SVihas Mak return true; 163198a26b69SVihas Mak return false; 1632c50d8ae3SPaolo Bonzini } 1633c50d8ae3SPaolo Bonzini 1634c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1635c50d8ae3SPaolo Bonzini 16362ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 16372ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 16382ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 163972ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1640c50d8ae3SPaolo Bonzini { 1641c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 164268be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 164368be1306SDavid Matlack int rmap_count; 1644c50d8ae3SPaolo Bonzini 164557354682SSean Christopherson sp = sptep_to_sp(spte); 164679e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 164781cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 164881cb4657SDavid Matlack 164993e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 16502ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1651c50d8ae3SPaolo Bonzini 1652604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1653604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 165468be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16559202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 16561b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 165768be1306SDavid Matlack } 1658c50d8ae3SPaolo Bonzini } 1659c50d8ae3SPaolo Bonzini 16602ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 166172ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16622ff9039aSDavid Matlack { 16632ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16642ff9039aSDavid Matlack 16656a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16662ff9039aSDavid Matlack } 16672ff9039aSDavid Matlack 16683039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1669c50d8ae3SPaolo Bonzini { 1670e2209710SBen Gardon bool young = false; 1671f8e14497SBen Gardon 1672e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1673aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16743039bcc7SSean Christopherson 16751f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16763039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1677f8e14497SBen Gardon 1678f8e14497SBen Gardon return young; 1679c50d8ae3SPaolo Bonzini } 1680c50d8ae3SPaolo Bonzini 16813039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1682c50d8ae3SPaolo Bonzini { 1683e2209710SBen Gardon bool young = false; 1684f8e14497SBen Gardon 1685e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1686aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 16873039bcc7SSean Christopherson 16881f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16893039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1690f8e14497SBen Gardon 1691f8e14497SBen Gardon return young; 1692c50d8ae3SPaolo Bonzini } 1693c50d8ae3SPaolo Bonzini 169458da926cSSean Christopherson static void kvm_mmu_check_sptes_at_free(struct kvm_mmu_page *sp) 1695c50d8ae3SPaolo Bonzini { 1696870d4d4eSSean Christopherson #ifdef CONFIG_KVM_PROVE_MMU 1697242a6dd8SSean Christopherson int i; 1698c50d8ae3SPaolo Bonzini 1699242a6dd8SSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 17000fe6370eSSean Christopherson if (KVM_MMU_WARN_ON(is_shadow_present_pte(sp->spt[i]))) 170158da926cSSean Christopherson pr_err_ratelimited("SPTE %llx (@ %p) for gfn %llx shadow-present at free", 170258da926cSSean Christopherson sp->spt[i], &sp->spt[i], 170358da926cSSean Christopherson kvm_mmu_page_get_gfn(sp, i)); 1704c50d8ae3SPaolo Bonzini } 1705c50d8ae3SPaolo Bonzini #endif 170658da926cSSean Christopherson } 1707c50d8ae3SPaolo Bonzini 1708c50d8ae3SPaolo Bonzini /* 1709c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1710c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1711c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1712c50d8ae3SPaolo Bonzini * faster 1713c50d8ae3SPaolo Bonzini */ 1714d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1715c50d8ae3SPaolo Bonzini { 1716c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1717c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1718c50d8ae3SPaolo Bonzini } 1719c50d8ae3SPaolo Bonzini 172043a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 172143a063caSYosry Ahmed { 172243a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 172343a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 172443a063caSYosry Ahmed } 172543a063caSYosry Ahmed 172643a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 172743a063caSYosry Ahmed { 172843a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 172943a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 173043a063caSYosry Ahmed } 173143a063caSYosry Ahmed 173287654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1733c50d8ae3SPaolo Bonzini { 173458da926cSSean Christopherson kvm_mmu_check_sptes_at_free(sp); 173558da926cSSean Christopherson 1736c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1737c50d8ae3SPaolo Bonzini list_del(&sp->link); 1738c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1739c50d8ae3SPaolo Bonzini if (!sp->role.direct) 17406a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1741c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1742c50d8ae3SPaolo Bonzini } 1743c50d8ae3SPaolo Bonzini 1744c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1745c50d8ae3SPaolo Bonzini { 1746c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1747c50d8ae3SPaolo Bonzini } 1748c50d8ae3SPaolo Bonzini 17492ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1750c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1751c50d8ae3SPaolo Bonzini { 1752c50d8ae3SPaolo Bonzini if (!parent_pte) 1753c50d8ae3SPaolo Bonzini return; 1754c50d8ae3SPaolo Bonzini 17552ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1756c50d8ae3SPaolo Bonzini } 1757c50d8ae3SPaolo Bonzini 1758069f30c6SMingwei Zhang static void mmu_page_remove_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 1759c50d8ae3SPaolo Bonzini u64 *parent_pte) 1760c50d8ae3SPaolo Bonzini { 1761069f30c6SMingwei Zhang pte_list_remove(kvm, parent_pte, &sp->parent_ptes); 1762c50d8ae3SPaolo Bonzini } 1763c50d8ae3SPaolo Bonzini 1764069f30c6SMingwei Zhang static void drop_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 1765c50d8ae3SPaolo Bonzini u64 *parent_pte) 1766c50d8ae3SPaolo Bonzini { 1767069f30c6SMingwei Zhang mmu_page_remove_parent_pte(kvm, sp, parent_pte); 1768c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1769c50d8ae3SPaolo Bonzini } 1770c50d8ae3SPaolo Bonzini 1771c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1772c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1773c50d8ae3SPaolo Bonzini { 1774c50d8ae3SPaolo Bonzini u64 *sptep; 1775c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1776c50d8ae3SPaolo Bonzini 1777c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1778c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1779c50d8ae3SPaolo Bonzini } 1780c50d8ae3SPaolo Bonzini } 1781c50d8ae3SPaolo Bonzini 1782c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1783c50d8ae3SPaolo Bonzini { 1784c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1785c50d8ae3SPaolo Bonzini 178657354682SSean Christopherson sp = sptep_to_sp(spte); 178779e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1788c50d8ae3SPaolo Bonzini return; 1789c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1790c50d8ae3SPaolo Bonzini return; 1791c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1792c50d8ae3SPaolo Bonzini } 1793c50d8ae3SPaolo Bonzini 1794c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1795c50d8ae3SPaolo Bonzini 1796c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1797c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1798c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1799c50d8ae3SPaolo Bonzini unsigned int idx; 1800c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1801c50d8ae3SPaolo Bonzini unsigned int nr; 1802c50d8ae3SPaolo Bonzini }; 1803c50d8ae3SPaolo Bonzini 1804c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1805c50d8ae3SPaolo Bonzini int idx) 1806c50d8ae3SPaolo Bonzini { 1807c50d8ae3SPaolo Bonzini int i; 1808c50d8ae3SPaolo Bonzini 1809c50d8ae3SPaolo Bonzini if (sp->unsync) 1810c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1811c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1812c50d8ae3SPaolo Bonzini return 0; 1813c50d8ae3SPaolo Bonzini 1814c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1815c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1816c50d8ae3SPaolo Bonzini pvec->nr++; 1817c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1818c50d8ae3SPaolo Bonzini } 1819c50d8ae3SPaolo Bonzini 1820c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1821c50d8ae3SPaolo Bonzini { 1822c50d8ae3SPaolo Bonzini --sp->unsync_children; 182320ba462dSSean Christopherson WARN_ON_ONCE((int)sp->unsync_children < 0); 1824c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1825c50d8ae3SPaolo Bonzini } 1826c50d8ae3SPaolo Bonzini 1827c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1828c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1829c50d8ae3SPaolo Bonzini { 1830c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1831c50d8ae3SPaolo Bonzini 1832c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1833c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1834c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1835c50d8ae3SPaolo Bonzini 1836c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1837c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1838c50d8ae3SPaolo Bonzini continue; 1839c50d8ae3SPaolo Bonzini } 1840c50d8ae3SPaolo Bonzini 18415e3edd7eSSean Christopherson child = spte_to_child_sp(ent); 1842c50d8ae3SPaolo Bonzini 1843c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1844c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1845c50d8ae3SPaolo Bonzini return -ENOSPC; 1846c50d8ae3SPaolo Bonzini 1847c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1848c50d8ae3SPaolo Bonzini if (!ret) { 1849c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1850c50d8ae3SPaolo Bonzini continue; 1851c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1852c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1853c50d8ae3SPaolo Bonzini } else 1854c50d8ae3SPaolo Bonzini return ret; 1855c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1856c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1857c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1858c50d8ae3SPaolo Bonzini return -ENOSPC; 1859c50d8ae3SPaolo Bonzini } else 1860c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1861c50d8ae3SPaolo Bonzini } 1862c50d8ae3SPaolo Bonzini 1863c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1864c50d8ae3SPaolo Bonzini } 1865c50d8ae3SPaolo Bonzini 1866c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1867c50d8ae3SPaolo Bonzini 1868c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1869c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1870c50d8ae3SPaolo Bonzini { 1871c50d8ae3SPaolo Bonzini pvec->nr = 0; 1872c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1873c50d8ae3SPaolo Bonzini return 0; 1874c50d8ae3SPaolo Bonzini 1875c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1876c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1877c50d8ae3SPaolo Bonzini } 1878c50d8ae3SPaolo Bonzini 1879c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1880c50d8ae3SPaolo Bonzini { 188120ba462dSSean Christopherson WARN_ON_ONCE(!sp->unsync); 1882c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1883c50d8ae3SPaolo Bonzini sp->unsync = 0; 1884c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1885c50d8ae3SPaolo Bonzini } 1886c50d8ae3SPaolo Bonzini 1887c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1888c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1889c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1890c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1891c50d8ae3SPaolo Bonzini 1892767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1893767d8d8dSLai Jiangshan { 1894767d8d8dSLai Jiangshan if (sp->role.direct) 1895767d8d8dSLai Jiangshan return false; 1896767d8d8dSLai Jiangshan 189784e5ffd0SLai Jiangshan if (sp->role.passthrough) 189884e5ffd0SLai Jiangshan return false; 189984e5ffd0SLai Jiangshan 1900767d8d8dSLai Jiangshan return true; 1901767d8d8dSLai Jiangshan } 1902767d8d8dSLai Jiangshan 1903ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1904ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1905c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1906c50d8ae3SPaolo Bonzini } else 1907c50d8ae3SPaolo Bonzini 1908767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1909ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1910ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1911767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1912c50d8ae3SPaolo Bonzini 191390e44470SLai Jiangshan static bool kvm_sync_page_check(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 191490e44470SLai Jiangshan { 191590e44470SLai Jiangshan union kvm_mmu_page_role root_role = vcpu->arch.mmu->root_role; 191690e44470SLai Jiangshan 191790e44470SLai Jiangshan /* 191890e44470SLai Jiangshan * Ignore various flags when verifying that it's safe to sync a shadow 191990e44470SLai Jiangshan * page using the current MMU context. 192090e44470SLai Jiangshan * 192190e44470SLai Jiangshan * - level: not part of the overall MMU role and will never match as the MMU's 192290e44470SLai Jiangshan * level tracks the root level 192390e44470SLai Jiangshan * - access: updated based on the new guest PTE 192490e44470SLai Jiangshan * - quadrant: not part of the overall MMU role (similar to level) 192590e44470SLai Jiangshan */ 192690e44470SLai Jiangshan const union kvm_mmu_page_role sync_role_ign = { 192790e44470SLai Jiangshan .level = 0xf, 192890e44470SLai Jiangshan .access = 0x7, 192990e44470SLai Jiangshan .quadrant = 0x3, 193090e44470SLai Jiangshan .passthrough = 0x1, 193190e44470SLai Jiangshan }; 193290e44470SLai Jiangshan 193390e44470SLai Jiangshan /* 193490e44470SLai Jiangshan * Direct pages can never be unsync, and KVM should never attempt to 193590e44470SLai Jiangshan * sync a shadow page for a different MMU context, e.g. if the role 193690e44470SLai Jiangshan * differs then the memslot lookup (SMM vs. non-SMM) will be bogus, the 193790e44470SLai Jiangshan * reserved bits checks will be wrong, etc... 193890e44470SLai Jiangshan */ 1939c3c6c9fcSLai Jiangshan if (WARN_ON_ONCE(sp->role.direct || !vcpu->arch.mmu->sync_spte || 194090e44470SLai Jiangshan (sp->role.word ^ root_role.word) & ~sync_role_ign.word)) 194190e44470SLai Jiangshan return false; 194290e44470SLai Jiangshan 194390e44470SLai Jiangshan return true; 194490e44470SLai Jiangshan } 194590e44470SLai Jiangshan 194619ace7d6SLai Jiangshan static int kvm_sync_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int i) 194719ace7d6SLai Jiangshan { 194819ace7d6SLai Jiangshan if (!sp->spt[i]) 194919ace7d6SLai Jiangshan return 0; 195019ace7d6SLai Jiangshan 195119ace7d6SLai Jiangshan return vcpu->arch.mmu->sync_spte(vcpu, sp, i); 195219ace7d6SLai Jiangshan } 195319ace7d6SLai Jiangshan 195490e44470SLai Jiangshan static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 195590e44470SLai Jiangshan { 1956c3c6c9fcSLai Jiangshan int flush = 0; 1957c3c6c9fcSLai Jiangshan int i; 1958c3c6c9fcSLai Jiangshan 195990e44470SLai Jiangshan if (!kvm_sync_page_check(vcpu, sp)) 196090e44470SLai Jiangshan return -1; 196190e44470SLai Jiangshan 1962c3c6c9fcSLai Jiangshan for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 196319ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, i); 1964c3c6c9fcSLai Jiangshan 1965c3c6c9fcSLai Jiangshan if (ret < -1) 1966c3c6c9fcSLai Jiangshan return -1; 1967c3c6c9fcSLai Jiangshan flush |= ret; 1968c3c6c9fcSLai Jiangshan } 1969c3c6c9fcSLai Jiangshan 1970c3c6c9fcSLai Jiangshan /* 1971c3c6c9fcSLai Jiangshan * Note, any flush is purely for KVM's correctness, e.g. when dropping 1972c3c6c9fcSLai Jiangshan * an existing SPTE or clearing W/A/D bits to ensure an mmu_notifier 1973c3c6c9fcSLai Jiangshan * unmap or dirty logging event doesn't fail to flush. The guest is 1974c3c6c9fcSLai Jiangshan * responsible for flushing the TLB to ensure any changes in protection 1975c3c6c9fcSLai Jiangshan * bits are recognized, i.e. until the guest flushes or page faults on 1976c3c6c9fcSLai Jiangshan * a relevant address, KVM is architecturally allowed to let vCPUs use 1977c3c6c9fcSLai Jiangshan * cached translations with the old protection bits. 1978c3c6c9fcSLai Jiangshan */ 1979c3c6c9fcSLai Jiangshan return flush; 198090e44470SLai Jiangshan } 198190e44470SLai Jiangshan 19828d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 1983c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 1984c50d8ae3SPaolo Bonzini { 198590e44470SLai Jiangshan int ret = __kvm_sync_page(vcpu, sp); 1986c3e5e415SLai Jiangshan 19878d5678a7SHou Wenlong if (ret < 0) 1988c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 19898d5678a7SHou Wenlong return ret; 1990c50d8ae3SPaolo Bonzini } 1991c50d8ae3SPaolo Bonzini 1992c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 1993c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 1994c50d8ae3SPaolo Bonzini bool remote_flush) 1995c50d8ae3SPaolo Bonzini { 1996c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 1997c50d8ae3SPaolo Bonzini return false; 1998c50d8ae3SPaolo Bonzini 1999c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 2000c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 2001c50d8ae3SPaolo Bonzini else 2002c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2003c50d8ae3SPaolo Bonzini return true; 2004c50d8ae3SPaolo Bonzini } 2005c50d8ae3SPaolo Bonzini 2006c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 2007c50d8ae3SPaolo Bonzini { 2008a955cad8SSean Christopherson if (sp->role.invalid) 2009a955cad8SSean Christopherson return true; 2010a955cad8SSean Christopherson 2011fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 2012de0322f5SSean Christopherson return !is_tdp_mmu_page(sp) && 2013c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 2014c50d8ae3SPaolo Bonzini } 2015c50d8ae3SPaolo Bonzini 2016c50d8ae3SPaolo Bonzini struct mmu_page_path { 2017c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 2018c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 2019c50d8ae3SPaolo Bonzini }; 2020c50d8ae3SPaolo Bonzini 2021c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 2022c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 2023c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 2024c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 2025c50d8ae3SPaolo Bonzini 2026c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 2027c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 2028c50d8ae3SPaolo Bonzini int i) 2029c50d8ae3SPaolo Bonzini { 2030c50d8ae3SPaolo Bonzini int n; 2031c50d8ae3SPaolo Bonzini 2032c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 2033c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 2034c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 2035c50d8ae3SPaolo Bonzini int level = sp->role.level; 2036c50d8ae3SPaolo Bonzini 2037c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 20383bae0459SSean Christopherson if (level == PG_LEVEL_4K) 2039c50d8ae3SPaolo Bonzini break; 2040c50d8ae3SPaolo Bonzini 2041c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2042c50d8ae3SPaolo Bonzini } 2043c50d8ae3SPaolo Bonzini 2044c50d8ae3SPaolo Bonzini return n; 2045c50d8ae3SPaolo Bonzini } 2046c50d8ae3SPaolo Bonzini 2047c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 2048c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 2049c50d8ae3SPaolo Bonzini { 2050c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2051c50d8ae3SPaolo Bonzini int level; 2052c50d8ae3SPaolo Bonzini 2053c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 2054c50d8ae3SPaolo Bonzini return 0; 2055c50d8ae3SPaolo Bonzini 205620ba462dSSean Christopherson WARN_ON_ONCE(pvec->page[0].idx != INVALID_INDEX); 2057c50d8ae3SPaolo Bonzini 2058c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 2059c50d8ae3SPaolo Bonzini level = sp->role.level; 206020ba462dSSean Christopherson WARN_ON_ONCE(level == PG_LEVEL_4K); 2061c50d8ae3SPaolo Bonzini 2062c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2063c50d8ae3SPaolo Bonzini 2064c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 2065c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 2066c50d8ae3SPaolo Bonzini */ 2067c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 2068c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 2069c50d8ae3SPaolo Bonzini } 2070c50d8ae3SPaolo Bonzini 2071c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 2072c50d8ae3SPaolo Bonzini { 2073c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2074c50d8ae3SPaolo Bonzini unsigned int level = 0; 2075c50d8ae3SPaolo Bonzini 2076c50d8ae3SPaolo Bonzini do { 2077c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 2078c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 2079c50d8ae3SPaolo Bonzini if (!sp) 2080c50d8ae3SPaolo Bonzini return; 2081c50d8ae3SPaolo Bonzini 208220ba462dSSean Christopherson WARN_ON_ONCE(idx == INVALID_INDEX); 2083c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 2084c50d8ae3SPaolo Bonzini level++; 2085c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 2086c50d8ae3SPaolo Bonzini } 2087c50d8ae3SPaolo Bonzini 208865855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 208965855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 2090c50d8ae3SPaolo Bonzini { 2091c50d8ae3SPaolo Bonzini int i; 2092c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2093c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2094c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2095c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2096c50d8ae3SPaolo Bonzini bool flush = false; 2097c50d8ae3SPaolo Bonzini 2098c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2099c50d8ae3SPaolo Bonzini bool protected = false; 2100c50d8ae3SPaolo Bonzini 2101c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 2102cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 2103c50d8ae3SPaolo Bonzini 2104c50d8ae3SPaolo Bonzini if (protected) { 21055591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 2106c50d8ae3SPaolo Bonzini flush = false; 2107c50d8ae3SPaolo Bonzini } 2108c50d8ae3SPaolo Bonzini 2109c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2110479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 21118d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 2112c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2113c50d8ae3SPaolo Bonzini } 2114531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2115c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 211665855ed8SLai Jiangshan if (!can_yield) { 211765855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 211865855ed8SLai Jiangshan return -EINTR; 211965855ed8SLai Jiangshan } 212065855ed8SLai Jiangshan 2121531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2122c50d8ae3SPaolo Bonzini flush = false; 2123c50d8ae3SPaolo Bonzini } 2124c50d8ae3SPaolo Bonzini } 2125c50d8ae3SPaolo Bonzini 2126c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 212765855ed8SLai Jiangshan return 0; 2128c50d8ae3SPaolo Bonzini } 2129c50d8ae3SPaolo Bonzini 2130c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2131c50d8ae3SPaolo Bonzini { 2132c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2133c50d8ae3SPaolo Bonzini } 2134c50d8ae3SPaolo Bonzini 2135c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2136c50d8ae3SPaolo Bonzini { 213757354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2138c50d8ae3SPaolo Bonzini } 2139c50d8ae3SPaolo Bonzini 2140cbd858b1SDavid Matlack /* 2141cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2142cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2143cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2144cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2145cbd858b1SDavid Matlack */ 21463cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 21473cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 214894c81364SDavid Matlack gfn_t gfn, 214994c81364SDavid Matlack struct hlist_head *sp_list, 21502e65e842SDavid Matlack union kvm_mmu_page_role role) 2151c50d8ae3SPaolo Bonzini { 2152c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 21538d5678a7SHou Wenlong int ret; 2154c50d8ae3SPaolo Bonzini int collisions = 0; 2155c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2156c50d8ae3SPaolo Bonzini 21573cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2158c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2159c50d8ae3SPaolo Bonzini collisions++; 2160c50d8ae3SPaolo Bonzini continue; 2161c50d8ae3SPaolo Bonzini } 2162c50d8ae3SPaolo Bonzini 2163ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2164ddc16abbSSean Christopherson /* 2165ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2166ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2167ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2168ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2169ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2170ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2171ddc16abbSSean Christopherson * upper-level page will be write-protected. 2172ddc16abbSSean Christopherson */ 21732e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 21743cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2175ddc16abbSSean Christopherson &invalid_list); 2176c50d8ae3SPaolo Bonzini continue; 2177ddc16abbSSean Christopherson } 2178c50d8ae3SPaolo Bonzini 2179bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2180bb924ca6SDavid Matlack if (sp->role.direct) 218194c81364SDavid Matlack goto out; 2182fb58a9c3SSean Christopherson 2183c50d8ae3SPaolo Bonzini if (sp->unsync) { 2184cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2185cbd858b1SDavid Matlack break; 2186cbd858b1SDavid Matlack 218707dc4f35SSean Christopherson /* 2188479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 218907dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 219007dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 219107dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 219207dc4f35SSean Christopherson * overhead of write protection is not incurred until the 219307dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 219407dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 219507dc4f35SSean Christopherson * 219607dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 219707dc4f35SSean Christopherson * in order to rebuild it. 2198c50d8ae3SPaolo Bonzini */ 21998d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 22008d5678a7SHou Wenlong if (ret < 0) 2201c50d8ae3SPaolo Bonzini break; 2202c50d8ae3SPaolo Bonzini 220320ba462dSSean Christopherson WARN_ON_ONCE(!list_empty(&invalid_list)); 22048d5678a7SHou Wenlong if (ret > 0) 22053cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2206c50d8ae3SPaolo Bonzini } 2207c50d8ae3SPaolo Bonzini 2208c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2209fb58a9c3SSean Christopherson 2210c50d8ae3SPaolo Bonzini goto out; 2211c50d8ae3SPaolo Bonzini } 2212c50d8ae3SPaolo Bonzini 221394c81364SDavid Matlack sp = NULL; 22143cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2215c50d8ae3SPaolo Bonzini 221694c81364SDavid Matlack out: 22173cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 221894c81364SDavid Matlack 22193cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 22203cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 222194c81364SDavid Matlack return sp; 222294c81364SDavid Matlack } 222394c81364SDavid Matlack 22242f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 22252f8b1b53SDavid Matlack struct shadow_page_caches { 22262f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 22272f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 22286a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 22292f8b1b53SDavid Matlack }; 22302f8b1b53SDavid Matlack 2231336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 22322f8b1b53SDavid Matlack struct shadow_page_caches *caches, 223394c81364SDavid Matlack gfn_t gfn, 223494c81364SDavid Matlack struct hlist_head *sp_list, 223594c81364SDavid Matlack union kvm_mmu_page_role role) 223694c81364SDavid Matlack { 2237c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2238c306aec8SDavid Matlack 22392f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 22402f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2241c306aec8SDavid Matlack if (!role.direct) 22426a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2243c306aec8SDavid Matlack 2244c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2245c306aec8SDavid Matlack 224655c510e2SSean Christopherson INIT_LIST_HEAD(&sp->possible_nx_huge_page_link); 2247428e9216SSean Christopherson 2248c306aec8SDavid Matlack /* 2249c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2250c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2251c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2252c306aec8SDavid Matlack */ 2253336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2254336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 225543a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2256c50d8ae3SPaolo Bonzini 2257c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2258c50d8ae3SPaolo Bonzini sp->role = role; 2259ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2260be911771SDavid Matlack if (sp_has_gptes(sp)) 2261336081fbSDavid Matlack account_shadowed(kvm, sp); 2262ddc16abbSSean Christopherson 226394c81364SDavid Matlack return sp; 226494c81364SDavid Matlack } 226594c81364SDavid Matlack 2266cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 22673cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 22683cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 22692f8b1b53SDavid Matlack struct shadow_page_caches *caches, 227087654643SDavid Matlack gfn_t gfn, 227194c81364SDavid Matlack union kvm_mmu_page_role role) 227294c81364SDavid Matlack { 227394c81364SDavid Matlack struct hlist_head *sp_list; 227494c81364SDavid Matlack struct kvm_mmu_page *sp; 227594c81364SDavid Matlack bool created = false; 227694c81364SDavid Matlack 22773cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 227894c81364SDavid Matlack 22793cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 228094c81364SDavid Matlack if (!sp) { 228194c81364SDavid Matlack created = true; 22823cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 228394c81364SDavid Matlack } 228494c81364SDavid Matlack 228594c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2286c50d8ae3SPaolo Bonzini return sp; 2287c50d8ae3SPaolo Bonzini } 2288c50d8ae3SPaolo Bonzini 22892f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 22902f8b1b53SDavid Matlack gfn_t gfn, 22912f8b1b53SDavid Matlack union kvm_mmu_page_role role) 22922f8b1b53SDavid Matlack { 22932f8b1b53SDavid Matlack struct shadow_page_caches caches = { 22942f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 22952f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 22966a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 22972f8b1b53SDavid Matlack }; 22982f8b1b53SDavid Matlack 22993cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 23002f8b1b53SDavid Matlack } 23012f8b1b53SDavid Matlack 230239944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 230339944ab9SSean Christopherson unsigned int access) 23042e65e842SDavid Matlack { 23052e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 23062e65e842SDavid Matlack union kvm_mmu_page_role role; 23072e65e842SDavid Matlack 23082e65e842SDavid Matlack role = parent_sp->role; 23092e65e842SDavid Matlack role.level--; 23102e65e842SDavid Matlack role.access = access; 23112e65e842SDavid Matlack role.direct = direct; 23122e65e842SDavid Matlack role.passthrough = 0; 23132e65e842SDavid Matlack 23142e65e842SDavid Matlack /* 23152e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 23162e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 23172e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 23182e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 23192e65e842SDavid Matlack * requires extra bookkeeping in the role. 23202e65e842SDavid Matlack * 23212e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 23222e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 23232e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 23242e65e842SDavid Matlack * the address space each maps. 23252e65e842SDavid Matlack * 23262e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 23272e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 23282e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 23292e65e842SDavid Matlack * 233039944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 233139944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 233239944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 233339944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 233439944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 233539944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 233639944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 233739944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 233839944ab9SSean Christopherson * _least_ significant bit of the PDE index. 23392e65e842SDavid Matlack */ 23402e65e842SDavid Matlack if (role.has_4_byte_gpte) { 23412e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 234279e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 23432e65e842SDavid Matlack } 23442e65e842SDavid Matlack 23452e65e842SDavid Matlack return role; 23462e65e842SDavid Matlack } 23472e65e842SDavid Matlack 23482e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 23492e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 23502e65e842SDavid Matlack bool direct, unsigned int access) 23512e65e842SDavid Matlack { 23522e65e842SDavid Matlack union kvm_mmu_page_role role; 23532e65e842SDavid Matlack 23540cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 23550cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 23560cd8dc73SPaolo Bonzini 23572e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 235887654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 23592e65e842SDavid Matlack } 23602e65e842SDavid Matlack 2361c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2362c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2363c50d8ae3SPaolo Bonzini u64 addr) 2364c50d8ae3SPaolo Bonzini { 2365c50d8ae3SPaolo Bonzini iterator->addr = addr; 2366c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2367a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2368c50d8ae3SPaolo Bonzini 236912ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 23704d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2371347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 237212ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2373c50d8ae3SPaolo Bonzini 2374c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2375c50d8ae3SPaolo Bonzini /* 2376c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2377c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2378c50d8ae3SPaolo Bonzini */ 2379b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2380c50d8ae3SPaolo Bonzini 2381c50d8ae3SPaolo Bonzini iterator->shadow_addr 2382c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 23832ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2384c50d8ae3SPaolo Bonzini --iterator->level; 2385c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2386c50d8ae3SPaolo Bonzini iterator->level = 0; 2387c50d8ae3SPaolo Bonzini } 2388c50d8ae3SPaolo Bonzini } 2389c50d8ae3SPaolo Bonzini 2390c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2391c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2392c50d8ae3SPaolo Bonzini { 2393b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2394c50d8ae3SPaolo Bonzini addr); 2395c50d8ae3SPaolo Bonzini } 2396c50d8ae3SPaolo Bonzini 2397c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2398c50d8ae3SPaolo Bonzini { 23993bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2400c50d8ae3SPaolo Bonzini return false; 2401c50d8ae3SPaolo Bonzini 24022ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2403c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2404c50d8ae3SPaolo Bonzini return true; 2405c50d8ae3SPaolo Bonzini } 2406c50d8ae3SPaolo Bonzini 2407c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2408c50d8ae3SPaolo Bonzini u64 spte) 2409c50d8ae3SPaolo Bonzini { 24103e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2411c50d8ae3SPaolo Bonzini iterator->level = 0; 2412c50d8ae3SPaolo Bonzini return; 2413c50d8ae3SPaolo Bonzini } 2414c50d8ae3SPaolo Bonzini 24152ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2416c50d8ae3SPaolo Bonzini --iterator->level; 2417c50d8ae3SPaolo Bonzini } 2418c50d8ae3SPaolo Bonzini 2419c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2420c50d8ae3SPaolo Bonzini { 2421c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2422c50d8ae3SPaolo Bonzini } 2423c50d8ae3SPaolo Bonzini 24240cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 24250cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 242603787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2427c50d8ae3SPaolo Bonzini { 2428c50d8ae3SPaolo Bonzini u64 spte; 2429c50d8ae3SPaolo Bonzini 2430c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2431c50d8ae3SPaolo Bonzini 24320cd8dc73SPaolo Bonzini /* 24330cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 243403787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 243503787394SPaolo Bonzini * installing sp. 24360cd8dc73SPaolo Bonzini */ 24370cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 243803787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 24390cd8dc73SPaolo Bonzini 2440cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2441c50d8ae3SPaolo Bonzini 2442c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2443c50d8ae3SPaolo Bonzini 24442ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2445c50d8ae3SPaolo Bonzini 2446c4a48868SLai Jiangshan /* 2447c4a48868SLai Jiangshan * The non-direct sub-pagetable must be updated before linking. For 2448c4a48868SLai Jiangshan * L1 sp, the pagetable is updated via kvm_sync_page() in 2449c4a48868SLai Jiangshan * kvm_mmu_find_shadow_page() without write-protecting the gfn, 2450c4a48868SLai Jiangshan * so sp->unsync can be true or false. For higher level non-direct 2451c4a48868SLai Jiangshan * sp, the pagetable is updated/synced via mmu_sync_children() in 2452c4a48868SLai Jiangshan * FNAME(fetch)(), so sp->unsync_children can only be false. 2453c4a48868SLai Jiangshan * WARN_ON_ONCE() if anything happens unexpectedly. 2454c4a48868SLai Jiangshan */ 2455c4a48868SLai Jiangshan if (WARN_ON_ONCE(sp->unsync_children) || sp->unsync) 2456c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2457c50d8ae3SPaolo Bonzini } 2458c50d8ae3SPaolo Bonzini 24592ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 24602ff9039aSDavid Matlack struct kvm_mmu_page *sp) 24612ff9039aSDavid Matlack { 246203787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 24632ff9039aSDavid Matlack } 24642ff9039aSDavid Matlack 2465c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2466c50d8ae3SPaolo Bonzini unsigned direct_access) 2467c50d8ae3SPaolo Bonzini { 2468c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2469c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2470c50d8ae3SPaolo Bonzini 2471c50d8ae3SPaolo Bonzini /* 2472c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2473c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2474c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2475c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2476c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2477c50d8ae3SPaolo Bonzini */ 24785e3edd7eSSean Christopherson child = spte_to_child_sp(*sptep); 2479c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2480c50d8ae3SPaolo Bonzini return; 2481c50d8ae3SPaolo Bonzini 2482069f30c6SMingwei Zhang drop_parent_pte(vcpu->kvm, child, sptep); 24833cdf9374SHou Wenlong kvm_flush_remote_tlbs_sptep(vcpu->kvm, sptep); 2484c50d8ae3SPaolo Bonzini } 2485c50d8ae3SPaolo Bonzini } 2486c50d8ae3SPaolo Bonzini 24872de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 24882de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 24892de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2490c50d8ae3SPaolo Bonzini { 2491c50d8ae3SPaolo Bonzini u64 pte; 2492c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2493c50d8ae3SPaolo Bonzini 2494c50d8ae3SPaolo Bonzini pte = *spte; 2495c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2496c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2497c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2498c50d8ae3SPaolo Bonzini } else { 24995e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2500069f30c6SMingwei Zhang drop_parent_pte(kvm, child, spte); 25012de4085cSBen Gardon 25022de4085cSBen Gardon /* 25032de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 25042de4085cSBen Gardon * unlikely to be used again in the near future. This 25052de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 25062de4085cSBen Gardon */ 25072de4085cSBen Gardon if (tdp_enabled && invalid_list && 25082de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 25092de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 25102de4085cSBen Gardon invalid_list); 2511c50d8ae3SPaolo Bonzini } 2512ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2513c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2514ace569e0SSean Christopherson } 25152de4085cSBen Gardon return 0; 2516c50d8ae3SPaolo Bonzini } 2517c50d8ae3SPaolo Bonzini 25182de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 25192de4085cSBen Gardon struct kvm_mmu_page *sp, 25202de4085cSBen Gardon struct list_head *invalid_list) 2521c50d8ae3SPaolo Bonzini { 25222de4085cSBen Gardon int zapped = 0; 2523c50d8ae3SPaolo Bonzini unsigned i; 2524c50d8ae3SPaolo Bonzini 25252ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 25262de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 25272de4085cSBen Gardon 25282de4085cSBen Gardon return zapped; 2529c50d8ae3SPaolo Bonzini } 2530c50d8ae3SPaolo Bonzini 2531069f30c6SMingwei Zhang static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) 2532c50d8ae3SPaolo Bonzini { 2533c50d8ae3SPaolo Bonzini u64 *sptep; 2534c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2535c50d8ae3SPaolo Bonzini 2536c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2537069f30c6SMingwei Zhang drop_parent_pte(kvm, sp, sptep); 2538c50d8ae3SPaolo Bonzini } 2539c50d8ae3SPaolo Bonzini 2540c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2541c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2542c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2543c50d8ae3SPaolo Bonzini { 2544c50d8ae3SPaolo Bonzini int i, zapped = 0; 2545c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2546c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2547c50d8ae3SPaolo Bonzini 25483bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2549c50d8ae3SPaolo Bonzini return 0; 2550c50d8ae3SPaolo Bonzini 2551c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2552c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2553c50d8ae3SPaolo Bonzini 2554c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2555c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2556c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2557c50d8ae3SPaolo Bonzini zapped++; 2558c50d8ae3SPaolo Bonzini } 2559c50d8ae3SPaolo Bonzini } 2560c50d8ae3SPaolo Bonzini 2561c50d8ae3SPaolo Bonzini return zapped; 2562c50d8ae3SPaolo Bonzini } 2563c50d8ae3SPaolo Bonzini 2564c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2565c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2566c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2567c50d8ae3SPaolo Bonzini int *nr_zapped) 2568c50d8ae3SPaolo Bonzini { 2569527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2570c50d8ae3SPaolo Bonzini 257147b0c2e4SKazuki Takiguchi lockdep_assert_held_write(&kvm->mmu_lock); 2572c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2573c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2574c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 25752de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 2576069f30c6SMingwei Zhang kvm_mmu_unlink_parents(kvm, sp); 2577c50d8ae3SPaolo Bonzini 2578c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2579c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2580c50d8ae3SPaolo Bonzini 2581767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2582c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2583c50d8ae3SPaolo Bonzini 2584c50d8ae3SPaolo Bonzini if (sp->unsync) 2585c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2586c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2587c50d8ae3SPaolo Bonzini /* Count self */ 2588c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2589f95eec9bSSean Christopherson 2590f95eec9bSSean Christopherson /* 2591f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2592f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2593f95eec9bSSean Christopherson * !sp->root_count. 2594f95eec9bSSean Christopherson */ 2595f95eec9bSSean Christopherson if (sp->role.invalid) 2596f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2597f95eec9bSSean Christopherson else 2598c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 259943a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2600c50d8ae3SPaolo Bonzini } else { 2601f95eec9bSSean Christopherson /* 2602f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2603f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2604f95eec9bSSean Christopherson */ 2605f95eec9bSSean Christopherson list_del(&sp->link); 2606c50d8ae3SPaolo Bonzini 2607c50d8ae3SPaolo Bonzini /* 2608c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2609c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2610c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2611c50d8ae3SPaolo Bonzini */ 2612527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2613c50d8ae3SPaolo Bonzini } 2614c50d8ae3SPaolo Bonzini 261555c510e2SSean Christopherson if (sp->nx_huge_page_disallowed) 261655c510e2SSean Christopherson unaccount_nx_huge_page(kvm, sp); 2617c50d8ae3SPaolo Bonzini 2618c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2619527d5cd7SSean Christopherson 2620527d5cd7SSean Christopherson /* 2621527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2622527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2623527d5cd7SSean Christopherson */ 2624527d5cd7SSean Christopherson if (zapped_root) 2625527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2626c50d8ae3SPaolo Bonzini return list_unstable; 2627c50d8ae3SPaolo Bonzini } 2628c50d8ae3SPaolo Bonzini 2629c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2630c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2631c50d8ae3SPaolo Bonzini { 2632c50d8ae3SPaolo Bonzini int nr_zapped; 2633c50d8ae3SPaolo Bonzini 2634c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2635c50d8ae3SPaolo Bonzini return nr_zapped; 2636c50d8ae3SPaolo Bonzini } 2637c50d8ae3SPaolo Bonzini 2638c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2639c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2640c50d8ae3SPaolo Bonzini { 2641c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2642c50d8ae3SPaolo Bonzini 2643c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2644c50d8ae3SPaolo Bonzini return; 2645c50d8ae3SPaolo Bonzini 2646c50d8ae3SPaolo Bonzini /* 2647c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2648c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2649c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2650c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2651c50d8ae3SPaolo Bonzini * 2652c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2653c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2654c50d8ae3SPaolo Bonzini */ 2655c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2656c50d8ae3SPaolo Bonzini 2657c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 265820ba462dSSean Christopherson WARN_ON_ONCE(!sp->role.invalid || sp->root_count); 265987654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2660c50d8ae3SPaolo Bonzini } 2661c50d8ae3SPaolo Bonzini } 2662c50d8ae3SPaolo Bonzini 26636b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 26646b82ef2cSSean Christopherson unsigned long nr_to_zap) 2665c50d8ae3SPaolo Bonzini { 26666b82ef2cSSean Christopherson unsigned long total_zapped = 0; 26676b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2668ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 26696b82ef2cSSean Christopherson bool unstable; 26706b82ef2cSSean Christopherson int nr_zapped; 2671c50d8ae3SPaolo Bonzini 2672c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2673ba7888ddSSean Christopherson return 0; 2674c50d8ae3SPaolo Bonzini 26756b82ef2cSSean Christopherson restart: 26768fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 26776b82ef2cSSean Christopherson /* 26786b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 26796b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 26806b82ef2cSSean Christopherson */ 26816b82ef2cSSean Christopherson if (sp->root_count) 26826b82ef2cSSean Christopherson continue; 26836b82ef2cSSean Christopherson 26846b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 26856b82ef2cSSean Christopherson &nr_zapped); 26866b82ef2cSSean Christopherson total_zapped += nr_zapped; 26876b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2688ba7888ddSSean Christopherson break; 2689ba7888ddSSean Christopherson 26906b82ef2cSSean Christopherson if (unstable) 26916b82ef2cSSean Christopherson goto restart; 2692ba7888ddSSean Christopherson } 26936b82ef2cSSean Christopherson 26946b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 26956b82ef2cSSean Christopherson 26966b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 26976b82ef2cSSean Christopherson return total_zapped; 26986b82ef2cSSean Christopherson } 26996b82ef2cSSean Christopherson 2700afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2701afe8d7e6SSean Christopherson { 2702afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2703afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2704afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2705afe8d7e6SSean Christopherson 2706afe8d7e6SSean Christopherson return 0; 2707c50d8ae3SPaolo Bonzini } 2708c50d8ae3SPaolo Bonzini 2709ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2710ba7888ddSSean Christopherson { 27116b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2712ba7888ddSSean Christopherson 27136b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2714ba7888ddSSean Christopherson return 0; 2715ba7888ddSSean Christopherson 27166b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2717ba7888ddSSean Christopherson 27186e6ec584SSean Christopherson /* 27196e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 27206e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 27216e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 27226e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2723c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 27246e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 27256e6ec584SSean Christopherson * page fault paths. 27266e6ec584SSean Christopherson */ 2727ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2728ba7888ddSSean Christopherson return -ENOSPC; 2729ba7888ddSSean Christopherson return 0; 2730ba7888ddSSean Christopherson } 2731ba7888ddSSean Christopherson 2732c50d8ae3SPaolo Bonzini /* 2733c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2734c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2735c50d8ae3SPaolo Bonzini */ 2736c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2737c50d8ae3SPaolo Bonzini { 2738531810caSBen Gardon write_lock(&kvm->mmu_lock); 2739c50d8ae3SPaolo Bonzini 2740c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 27416b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 27426b82ef2cSSean Christopherson goal_nr_mmu_pages); 2743c50d8ae3SPaolo Bonzini 2744c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2745c50d8ae3SPaolo Bonzini } 2746c50d8ae3SPaolo Bonzini 2747c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2748c50d8ae3SPaolo Bonzini 2749531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2750c50d8ae3SPaolo Bonzini } 2751c50d8ae3SPaolo Bonzini 2752c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2753c50d8ae3SPaolo Bonzini { 2754c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2755c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2756c50d8ae3SPaolo Bonzini int r; 2757c50d8ae3SPaolo Bonzini 2758c50d8ae3SPaolo Bonzini r = 0; 2759531810caSBen Gardon write_lock(&kvm->mmu_lock); 2760767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2761c50d8ae3SPaolo Bonzini r = 1; 2762c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2763c50d8ae3SPaolo Bonzini } 2764c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2765531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2766c50d8ae3SPaolo Bonzini 2767c50d8ae3SPaolo Bonzini return r; 2768c50d8ae3SPaolo Bonzini } 276996ad91aeSSean Christopherson 277096ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 277196ad91aeSSean Christopherson { 277296ad91aeSSean Christopherson gpa_t gpa; 277396ad91aeSSean Christopherson int r; 277496ad91aeSSean Christopherson 2775347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 277696ad91aeSSean Christopherson return 0; 277796ad91aeSSean Christopherson 277896ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 277996ad91aeSSean Christopherson 278096ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 278196ad91aeSSean Christopherson 278296ad91aeSSean Christopherson return r; 278396ad91aeSSean Christopherson } 2784c50d8ae3SPaolo Bonzini 27854d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2786c50d8ae3SPaolo Bonzini { 2787c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 27884d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2789c50d8ae3SPaolo Bonzini sp->unsync = 1; 2790c50d8ae3SPaolo Bonzini 2791c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2792c50d8ae3SPaolo Bonzini } 2793c50d8ae3SPaolo Bonzini 27940337f585SSean Christopherson /* 27950337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 27960337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 27970337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 27980337f585SSean Christopherson * be write-protected. 27990337f585SSean Christopherson */ 28008283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 28012839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2802c50d8ae3SPaolo Bonzini { 2803c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2804ce25681dSSean Christopherson bool locked = false; 2805c50d8ae3SPaolo Bonzini 28060337f585SSean Christopherson /* 28070337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 28080337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 28090337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 28100337f585SSean Christopherson */ 28114d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 28120337f585SSean Christopherson return -EPERM; 2813c50d8ae3SPaolo Bonzini 28140337f585SSean Christopherson /* 28150337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 28160337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 28170337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 28180337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 28190337f585SSean Christopherson */ 2820767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2821c50d8ae3SPaolo Bonzini if (!can_unsync) 28220337f585SSean Christopherson return -EPERM; 2823c50d8ae3SPaolo Bonzini 2824c50d8ae3SPaolo Bonzini if (sp->unsync) 2825c50d8ae3SPaolo Bonzini continue; 2826c50d8ae3SPaolo Bonzini 28272839180cSPaolo Bonzini if (prefetch) 2828f1c4a88cSLai Jiangshan return -EEXIST; 2829f1c4a88cSLai Jiangshan 2830ce25681dSSean Christopherson /* 2831ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2832ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2833ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2834ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2835ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2836ce25681dSSean Christopherson */ 2837ce25681dSSean Christopherson if (!locked) { 2838ce25681dSSean Christopherson locked = true; 28394d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2840ce25681dSSean Christopherson 2841ce25681dSSean Christopherson /* 2842ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2843ce25681dSSean Christopherson * may have since marked the page unsync. A false 2844ce25681dSSean Christopherson * positive on the unprotected check above is not 2845ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2846ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2847ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2848ce25681dSSean Christopherson */ 2849ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2850ce25681dSSean Christopherson continue; 2851ce25681dSSean Christopherson } 2852ce25681dSSean Christopherson 285320ba462dSSean Christopherson WARN_ON_ONCE(sp->role.level != PG_LEVEL_4K); 28544d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2855c50d8ae3SPaolo Bonzini } 2856ce25681dSSean Christopherson if (locked) 28574d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2858c50d8ae3SPaolo Bonzini 2859c50d8ae3SPaolo Bonzini /* 2860c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2861c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2862c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2863c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2864c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2865c50d8ae3SPaolo Bonzini * following could happen: 2866c50d8ae3SPaolo Bonzini * 2867c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2868c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2869c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2870c50d8ae3SPaolo Bonzini * to be writable 2871c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2872c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2873c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2874c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2875c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2876c50d8ae3SPaolo Bonzini * fault. 2877c50d8ae3SPaolo Bonzini * 2878c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2879c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2880c50d8ae3SPaolo Bonzini * 28810337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 28820337f585SSean Christopherson * false and skips the page. 2883c50d8ae3SPaolo Bonzini * 2884c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2885c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2886c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2887c50d8ae3SPaolo Bonzini * gets used. 2888c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2889c50d8ae3SPaolo Bonzini * as unsync 2890c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2891c50d8ae3SPaolo Bonzini * 2892c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2893264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2894264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2895c50d8ae3SPaolo Bonzini */ 2896c50d8ae3SPaolo Bonzini smp_wmb(); 2897c50d8ae3SPaolo Bonzini 28980337f585SSean Christopherson return 0; 2899c50d8ae3SPaolo Bonzini } 2900c50d8ae3SPaolo Bonzini 29018a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 29028a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2903a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2904799a4190SBen Gardon { 2905d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2906eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2907c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2908c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2909c50d8ae3SPaolo Bonzini bool flush = false; 2910ad67e480SPaolo Bonzini bool wrprot; 2911d786c778SPaolo Bonzini u64 spte; 2912c50d8ae3SPaolo Bonzini 2913a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2914a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 29152839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2916a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2917c50d8ae3SPaolo Bonzini 2918a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 29191075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2920a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2921a54aa15cSSean Christopherson return RET_PF_EMULATE; 2922a54aa15cSSean Christopherson } 2923a54aa15cSSean Christopherson 2924c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2925c50d8ae3SPaolo Bonzini /* 2926c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2927c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2928c50d8ae3SPaolo Bonzini */ 29293bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2930c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2931c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2932c50d8ae3SPaolo Bonzini 29335e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2934069f30c6SMingwei Zhang drop_parent_pte(vcpu->kvm, child, sptep); 2935c50d8ae3SPaolo Bonzini flush = true; 2936c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2937c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2938c50d8ae3SPaolo Bonzini flush = true; 2939c50d8ae3SPaolo Bonzini } else 2940c50d8ae3SPaolo Bonzini was_rmapped = 1; 2941c50d8ae3SPaolo Bonzini } 2942c50d8ae3SPaolo Bonzini 29432839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 29447158bee4SPaolo Bonzini true, host_writable, &spte); 2945d786c778SPaolo Bonzini 2946d786c778SPaolo Bonzini if (*sptep == spte) { 2947d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2948d786c778SPaolo Bonzini } else { 2949d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 29505959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2951c50d8ae3SPaolo Bonzini } 2952c50d8ae3SPaolo Bonzini 2953ad67e480SPaolo Bonzini if (wrprot) { 2954c50d8ae3SPaolo Bonzini if (write_fault) 2955c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2956c50d8ae3SPaolo Bonzini } 2957c50d8ae3SPaolo Bonzini 2958d786c778SPaolo Bonzini if (flush) 29594ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(vcpu->kvm, gfn, level); 2960c50d8ae3SPaolo Bonzini 2961c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2962d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 29636a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 29646a97575dSDavid Matlack } else { 29656a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 296679e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2967c50d8ae3SPaolo Bonzini } 2968c50d8ae3SPaolo Bonzini 2969c50d8ae3SPaolo Bonzini return ret; 2970c50d8ae3SPaolo Bonzini } 2971c50d8ae3SPaolo Bonzini 2972c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 2973c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2974c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 2975c50d8ae3SPaolo Bonzini { 2976c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 2977c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 29780a2b64c5SBen Gardon unsigned int access = sp->role.access; 2979c50d8ae3SPaolo Bonzini int i, ret; 2980c50d8ae3SPaolo Bonzini gfn_t gfn; 2981c50d8ae3SPaolo Bonzini 298279e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 2983c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 2984c50d8ae3SPaolo Bonzini if (!slot) 2985c50d8ae3SPaolo Bonzini return -1; 2986c50d8ae3SPaolo Bonzini 2987c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 2988c50d8ae3SPaolo Bonzini if (ret <= 0) 2989c50d8ae3SPaolo Bonzini return -1; 2990c50d8ae3SPaolo Bonzini 2991c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 29928a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 2993a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 2994c50d8ae3SPaolo Bonzini put_page(pages[i]); 2995c50d8ae3SPaolo Bonzini } 2996c50d8ae3SPaolo Bonzini 2997c50d8ae3SPaolo Bonzini return 0; 2998c50d8ae3SPaolo Bonzini } 2999c50d8ae3SPaolo Bonzini 3000c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 3001c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 3002c50d8ae3SPaolo Bonzini { 3003c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 3004c50d8ae3SPaolo Bonzini int i; 3005c50d8ae3SPaolo Bonzini 300620ba462dSSean Christopherson WARN_ON_ONCE(!sp->role.direct); 3007c50d8ae3SPaolo Bonzini 300879e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 3009c50d8ae3SPaolo Bonzini spte = sp->spt + i; 3010c50d8ae3SPaolo Bonzini 3011c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 3012c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 3013c50d8ae3SPaolo Bonzini if (!start) 3014c50d8ae3SPaolo Bonzini continue; 3015c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 3016c6cecc4bSSean Christopherson return; 3017c50d8ae3SPaolo Bonzini start = NULL; 3018c50d8ae3SPaolo Bonzini } else if (!start) 3019c50d8ae3SPaolo Bonzini start = spte; 3020c50d8ae3SPaolo Bonzini } 3021c6cecc4bSSean Christopherson if (start) 3022c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 3023c50d8ae3SPaolo Bonzini } 3024c50d8ae3SPaolo Bonzini 3025c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 3026c50d8ae3SPaolo Bonzini { 3027c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3028c50d8ae3SPaolo Bonzini 302957354682SSean Christopherson sp = sptep_to_sp(sptep); 3030c50d8ae3SPaolo Bonzini 3031c50d8ae3SPaolo Bonzini /* 3032c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 3033c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 3034c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 3035c50d8ae3SPaolo Bonzini */ 3036c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 3037c50d8ae3SPaolo Bonzini return; 3038c50d8ae3SPaolo Bonzini 30393bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 3040c50d8ae3SPaolo Bonzini return; 3041c50d8ae3SPaolo Bonzini 30424a42d848SDavid Stevens /* 30434a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 30444a42d848SDavid Stevens * accidentally prefetching those addresses. 30454a42d848SDavid Stevens */ 304620ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 30474a42d848SDavid Stevens return; 30484a42d848SDavid Stevens 3049c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 3050c50d8ae3SPaolo Bonzini } 3051c50d8ae3SPaolo Bonzini 305265e3b446SSean Christopherson /* 305365e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 305465e3b446SSean Christopherson * 305565e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 305665e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 305765e3b446SSean Christopherson * 305865e3b446SSean Christopherson * There are several ways to safely use this helper: 305965e3b446SSean Christopherson * 306020ec3ebdSChao Peng * - Check mmu_invalidate_retry_hva() after grabbing the mapping level, before 306165e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 306265e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 306365e3b446SSean Christopherson * 306465e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 306565e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 306665e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 306765e3b446SSean Christopherson * 306865e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 306965e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 307065e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 307165e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 307265e3b446SSean Christopherson * 307365e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 307465e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 307565e3b446SSean Christopherson * race with the primary MMU occurs. 307665e3b446SSean Christopherson */ 3077a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 30788ca6f063SBen Gardon const struct kvm_memory_slot *slot) 3079db543216SSean Christopherson { 3080284dc493SSean Christopherson int level = PG_LEVEL_4K; 3081db543216SSean Christopherson unsigned long hva; 308244187235SMingwei Zhang unsigned long flags; 308344187235SMingwei Zhang pgd_t pgd; 308444187235SMingwei Zhang p4d_t p4d; 308544187235SMingwei Zhang pud_t pud; 308644187235SMingwei Zhang pmd_t pmd; 3087db543216SSean Christopherson 30885d49f08cSSean Christopherson /* 3089293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 3090293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 3091293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 3092293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 3093293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 3094293e306eSSean Christopherson * read-only memslot. 3095293e306eSSean Christopherson */ 3096db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 3097db543216SSean Christopherson 309844187235SMingwei Zhang /* 309965e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 310065e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 310165e3b446SSean Christopherson * the original page table. 310244187235SMingwei Zhang */ 310344187235SMingwei Zhang local_irq_save(flags); 3104db543216SSean Christopherson 310565e3b446SSean Christopherson /* 310665e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 310765e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 310865e3b446SSean Christopherson * walk into the weeks, e.g. p*d_large() returns false (sees the old 310965e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 311065e3b446SSean Christopherson * of the old page table (sees the new value). 311165e3b446SSean Christopherson */ 311244187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 311344187235SMingwei Zhang if (pgd_none(pgd)) 311444187235SMingwei Zhang goto out; 311544187235SMingwei Zhang 311644187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 311744187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 311844187235SMingwei Zhang goto out; 311944187235SMingwei Zhang 312044187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 312144187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 312244187235SMingwei Zhang goto out; 312344187235SMingwei Zhang 312444187235SMingwei Zhang if (pud_large(pud)) { 312544187235SMingwei Zhang level = PG_LEVEL_1G; 312644187235SMingwei Zhang goto out; 312744187235SMingwei Zhang } 312844187235SMingwei Zhang 312944187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 313044187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 313144187235SMingwei Zhang goto out; 313244187235SMingwei Zhang 313344187235SMingwei Zhang if (pmd_large(pmd)) 313444187235SMingwei Zhang level = PG_LEVEL_2M; 313544187235SMingwei Zhang 313644187235SMingwei Zhang out: 313744187235SMingwei Zhang local_irq_restore(flags); 3138db543216SSean Christopherson return level; 3139db543216SSean Christopherson } 3140db543216SSean Christopherson 31418ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 31428ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 3143a8ac499bSSean Christopherson int max_level) 31441b6d9d9eSSean Christopherson { 31451b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3146ec607a56SPaolo Bonzini int host_level; 31471b6d9d9eSSean Christopherson 31481b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 31491b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 31501b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 31511b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 31521b6d9d9eSSean Christopherson break; 31531b6d9d9eSSean Christopherson } 31541b6d9d9eSSean Christopherson 31551b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 31561b6d9d9eSSean Christopherson return PG_LEVEL_4K; 31571b6d9d9eSSean Christopherson 3158a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3159ec607a56SPaolo Bonzini return min(host_level, max_level); 31601b6d9d9eSSean Christopherson } 31611b6d9d9eSSean Christopherson 316273a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 31630885904dSSean Christopherson { 3164e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 316517eff019SSean Christopherson kvm_pfn_t mask; 31660885904dSSean Christopherson 316773a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 31683cf06612SSean Christopherson 316973a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 317073a3c659SPaolo Bonzini return; 317117eff019SSean Christopherson 31725d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 317373a3c659SPaolo Bonzini return; 317417eff019SSean Christopherson 3175e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 317673a3c659SPaolo Bonzini return; 3177293e306eSSean Christopherson 31783cf06612SSean Christopherson /* 31793cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 31803cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 31813cf06612SSean Christopherson */ 318273a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 3183a8ac499bSSean Christopherson fault->gfn, fault->max_level); 318473a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 318573a3c659SPaolo Bonzini return; 31864cd071d1SSean Christopherson 31870885904dSSean Christopherson /* 318820ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 31894cd071d1SSean Christopherson * the pmd can't be split from under us. 31900885904dSSean Christopherson */ 319173a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 319273a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 319373a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 319473a3c659SPaolo Bonzini fault->pfn &= ~mask; 31950885904dSSean Christopherson } 31960885904dSSean Christopherson 3197536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3198c50d8ae3SPaolo Bonzini { 3199536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3200536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3201c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 320276901e56SMingwei Zhang !is_large_pte(spte) && 320376901e56SMingwei Zhang spte_to_child_sp(spte)->nx_huge_page_disallowed) { 3204c50d8ae3SPaolo Bonzini /* 32056c882ef4SDavid Matlack * A small SPTE exists for this pfn, but FNAME(fetch), 32066c882ef4SDavid Matlack * direct_map(), or kvm_tdp_mmu_map() would like to create a 32076c882ef4SDavid Matlack * large PTE instead: just force them to go down another level, 32086c882ef4SDavid Matlack * patching back for them into pfn the next 9 bits of the 32096c882ef4SDavid Matlack * address. 3210c50d8ae3SPaolo Bonzini */ 3211536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3212536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3213536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3214536f0e6aSPaolo Bonzini fault->goal_level--; 3215c50d8ae3SPaolo Bonzini } 3216c50d8ae3SPaolo Bonzini } 3217c50d8ae3SPaolo Bonzini 32186c882ef4SDavid Matlack static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3219c50d8ae3SPaolo Bonzini { 3220c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3221c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 322273a3c659SPaolo Bonzini int ret; 322343b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3224c50d8ae3SPaolo Bonzini 322573a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 32264cd071d1SSean Christopherson 3227f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 322843b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3229c50d8ae3SPaolo Bonzini /* 3230c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3231c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3232c50d8ae3SPaolo Bonzini */ 323373a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3234536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3235c50d8ae3SPaolo Bonzini 3236c667a3baSHou Wenlong base_gfn = gfn_round_for_level(fault->gfn, it.level); 323773a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3238c50d8ae3SPaolo Bonzini break; 3239c50d8ae3SPaolo Bonzini 32402e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 32410cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 32420cd8dc73SPaolo Bonzini continue; 3243c50d8ae3SPaolo Bonzini 3244c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 3245b5b0977fSSean Christopherson if (fault->huge_page_disallowed) 324655c510e2SSean Christopherson account_nx_huge_page(vcpu->kvm, sp, 3247428e9216SSean Christopherson fault->req_level >= it.level); 3248c50d8ae3SPaolo Bonzini } 3249c50d8ae3SPaolo Bonzini 3250b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3251b1a429fbSSean Christopherson return -EFAULT; 3252b1a429fbSSean Christopherson 32538a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3254a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 325512703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 325612703759SSean Christopherson return ret; 325712703759SSean Christopherson 3258c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3259c50d8ae3SPaolo Bonzini return ret; 3260c50d8ae3SPaolo Bonzini } 3261c50d8ae3SPaolo Bonzini 3262cd08d178SDavid Matlack static void kvm_send_hwpoison_signal(struct kvm_memory_slot *slot, gfn_t gfn) 3263c50d8ae3SPaolo Bonzini { 3264cd08d178SDavid Matlack unsigned long hva = gfn_to_hva_memslot(slot, gfn); 3265cd08d178SDavid Matlack 3266cd08d178SDavid Matlack send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); 3267c50d8ae3SPaolo Bonzini } 3268c50d8ae3SPaolo Bonzini 3269cd08d178SDavid Matlack static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3270c50d8ae3SPaolo Bonzini { 3271cd08d178SDavid Matlack if (is_sigpending_pfn(fault->pfn)) { 327276657687SPeter Xu kvm_handle_signal_exit(vcpu); 327376657687SPeter Xu return -EINTR; 327476657687SPeter Xu } 327576657687SPeter Xu 3276c50d8ae3SPaolo Bonzini /* 3277c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3278c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3279c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3280c50d8ae3SPaolo Bonzini */ 3281cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_RO_FAULT) 3282c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3283c50d8ae3SPaolo Bonzini 3284cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_HWPOISON) { 3285cd08d178SDavid Matlack kvm_send_hwpoison_signal(fault->slot, fault->gfn); 3286c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3287c50d8ae3SPaolo Bonzini } 3288c50d8ae3SPaolo Bonzini 3289c50d8ae3SPaolo Bonzini return -EFAULT; 3290c50d8ae3SPaolo Bonzini } 3291c50d8ae3SPaolo Bonzini 3292354c908cSDavid Matlack static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu, 3293354c908cSDavid Matlack struct kvm_page_fault *fault, 32945276c616SSean Christopherson unsigned int access) 3295c50d8ae3SPaolo Bonzini { 32963a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 32973a13f4feSPaolo Bonzini 32983a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3299c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 3300354c908cSDavid Matlack 330130ab5901SSean Christopherson /* 330230ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 330330ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 3304354c908cSDavid Matlack * MMIO SPTE will just be an expensive nop. 330530ab5901SSean Christopherson */ 3306354c908cSDavid Matlack if (unlikely(!enable_mmio_caching)) 33075276c616SSean Christopherson return RET_PF_EMULATE; 3308354c908cSDavid Matlack 3309354c908cSDavid Matlack /* 3310354c908cSDavid Matlack * Do not create an MMIO SPTE for a gfn greater than host.MAXPHYADDR, 3311354c908cSDavid Matlack * any guest that generates such gfns is running nested and is being 3312354c908cSDavid Matlack * tricked by L0 userspace (you can observe gfn > L1.MAXPHYADDR if and 3313354c908cSDavid Matlack * only if L1's MAXPHYADDR is inaccurate with respect to the 3314354c908cSDavid Matlack * hardware's). 3315354c908cSDavid Matlack */ 3316354c908cSDavid Matlack if (unlikely(fault->gfn > kvm_mmu_max_gfn())) 3317354c908cSDavid Matlack return RET_PF_EMULATE; 3318c50d8ae3SPaolo Bonzini 33195276c616SSean Christopherson return RET_PF_CONTINUE; 3320c50d8ae3SPaolo Bonzini } 3321c50d8ae3SPaolo Bonzini 33223c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3323c50d8ae3SPaolo Bonzini { 3324c50d8ae3SPaolo Bonzini /* 33255c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 33265c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 33275c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 33285c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3329c50d8ae3SPaolo Bonzini */ 33303c8ad5a6SPaolo Bonzini if (fault->rsvd) 3331c50d8ae3SPaolo Bonzini return false; 3332c50d8ae3SPaolo Bonzini 3333c50d8ae3SPaolo Bonzini /* 3334c50d8ae3SPaolo Bonzini * #PF can be fast if: 3335c50d8ae3SPaolo Bonzini * 333654275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 333754275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 333854275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 333954275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 334054275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 334154275f74SSean Christopherson * mechanism only supports direct MMUs. 334254275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 334354275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 334454275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 334554275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 334654275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3347c50d8ae3SPaolo Bonzini */ 33485c64aba5SSean Christopherson if (!fault->present) 33495c64aba5SSean Christopherson return !kvm_ad_enabled(); 33505c64aba5SSean Christopherson 33515c64aba5SSean Christopherson /* 33525c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 33535c64aba5SSean Christopherson * the "exec" flag. 33545c64aba5SSean Christopherson */ 33555c64aba5SSean Christopherson return fault->write; 3356c50d8ae3SPaolo Bonzini } 3357c50d8ae3SPaolo Bonzini 3358c50d8ae3SPaolo Bonzini /* 3359c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3360c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3361c50d8ae3SPaolo Bonzini */ 3362f3d90f90SSean Christopherson static bool fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, 3363f3d90f90SSean Christopherson struct kvm_page_fault *fault, 3364c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3365c50d8ae3SPaolo Bonzini { 3366c50d8ae3SPaolo Bonzini /* 3367c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3368c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3369c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3370c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3371c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3372c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3373c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3374c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3375c50d8ae3SPaolo Bonzini * 3376c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3377c50d8ae3SPaolo Bonzini */ 33782db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3379c50d8ae3SPaolo Bonzini return false; 3380c50d8ae3SPaolo Bonzini 3381e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3382e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3383c50d8ae3SPaolo Bonzini 3384c50d8ae3SPaolo Bonzini return true; 3385c50d8ae3SPaolo Bonzini } 3386c50d8ae3SPaolo Bonzini 33873c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3388c50d8ae3SPaolo Bonzini { 33893c8ad5a6SPaolo Bonzini if (fault->exec) 3390c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3391c50d8ae3SPaolo Bonzini 33923c8ad5a6SPaolo Bonzini if (fault->write) 3393c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3394c50d8ae3SPaolo Bonzini 3395c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3396c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3397c50d8ae3SPaolo Bonzini } 3398c50d8ae3SPaolo Bonzini 3399c50d8ae3SPaolo Bonzini /* 34006e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 34016e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 34026e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 34036e8eb206SDavid Matlack * 34046e8eb206SDavid Matlack * Contract: 34056e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 34066e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 34076e8eb206SDavid Matlack */ 34086e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 34096e8eb206SDavid Matlack { 34106e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 34116e8eb206SDavid Matlack u64 old_spte; 34126e8eb206SDavid Matlack u64 *sptep = NULL; 34136e8eb206SDavid Matlack 34146e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 34156e8eb206SDavid Matlack sptep = iterator.sptep; 34166e8eb206SDavid Matlack *spte = old_spte; 34176e8eb206SDavid Matlack } 34186e8eb206SDavid Matlack 34196e8eb206SDavid Matlack return sptep; 34206e8eb206SDavid Matlack } 34216e8eb206SDavid Matlack 34226e8eb206SDavid Matlack /* 3423c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3424c50d8ae3SPaolo Bonzini */ 34253c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3426c50d8ae3SPaolo Bonzini { 3427c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3428c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3429c50d8ae3SPaolo Bonzini u64 spte = 0ull; 34306e8eb206SDavid Matlack u64 *sptep = NULL; 3431c50d8ae3SPaolo Bonzini uint retry_count = 0; 3432c50d8ae3SPaolo Bonzini 34333c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3434c4371c2aSSean Christopherson return ret; 3435c50d8ae3SPaolo Bonzini 3436c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3437c50d8ae3SPaolo Bonzini 3438c50d8ae3SPaolo Bonzini do { 3439c50d8ae3SPaolo Bonzini u64 new_spte; 3440c50d8ae3SPaolo Bonzini 3441dfe0ecc6SSean Christopherson if (tdp_mmu_enabled) 34423c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 34436e8eb206SDavid Matlack else 34443c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3445c50d8ae3SPaolo Bonzini 3446ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3447ec89e643SSean Christopherson break; 3448ec89e643SSean Christopherson 34496e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3450c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3451c50d8ae3SPaolo Bonzini break; 3452c50d8ae3SPaolo Bonzini 3453c50d8ae3SPaolo Bonzini /* 3454c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3455c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3456c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3457c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3458c50d8ae3SPaolo Bonzini * current CPU took the fault. 3459c50d8ae3SPaolo Bonzini * 3460c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3461c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3462c50d8ae3SPaolo Bonzini */ 34633c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3464c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3465c50d8ae3SPaolo Bonzini break; 3466c50d8ae3SPaolo Bonzini } 3467c50d8ae3SPaolo Bonzini 3468c50d8ae3SPaolo Bonzini new_spte = spte; 3469c50d8ae3SPaolo Bonzini 347054275f74SSean Christopherson /* 347154275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 347254275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 347354275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 347454275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 347554275f74SSean Christopherson */ 347654275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3477c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3478c50d8ae3SPaolo Bonzini 3479c50d8ae3SPaolo Bonzini /* 348054275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 348154275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 348254275f74SSean Christopherson * that were write-protected for dirty-logging or access 348354275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 348454275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 348554275f74SSean Christopherson * The is_access_allowed() check above handles the common case 348654275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 348754275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 348854275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3489c50d8ae3SPaolo Bonzini */ 3490706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3491c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3492c50d8ae3SPaolo Bonzini 3493c50d8ae3SPaolo Bonzini /* 349410c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 349510c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 349610c30de0SJunaid Shahid * first page into the dirty-bitmap in 3497c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3498c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3499c50d8ae3SPaolo Bonzini * 3500c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3501c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3502c50d8ae3SPaolo Bonzini */ 350310c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 350410c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3505c50d8ae3SPaolo Bonzini break; 3506c50d8ae3SPaolo Bonzini } 3507c50d8ae3SPaolo Bonzini 3508c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3509c50d8ae3SPaolo Bonzini if (new_spte == spte || 35103c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3511c50d8ae3SPaolo Bonzini break; 3512c50d8ae3SPaolo Bonzini 3513c50d8ae3SPaolo Bonzini /* 3514c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3515c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 35163ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3517c50d8ae3SPaolo Bonzini */ 3518e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3519c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3520c50d8ae3SPaolo Bonzini break; 3521c4371c2aSSean Christopherson } 3522c50d8ae3SPaolo Bonzini 3523c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 35248d20bd63SSean Christopherson pr_warn_once("Fast #PF retrying more than 4 times.\n"); 3525c50d8ae3SPaolo Bonzini break; 3526c50d8ae3SPaolo Bonzini } 3527c50d8ae3SPaolo Bonzini 3528c50d8ae3SPaolo Bonzini } while (true); 3529c50d8ae3SPaolo Bonzini 3530f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3531c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3532c50d8ae3SPaolo Bonzini 35331075d41eSSean Christopherson if (ret != RET_PF_INVALID) 35341075d41eSSean Christopherson vcpu->stat.pf_fast++; 35351075d41eSSean Christopherson 3536c4371c2aSSean Christopherson return ret; 3537c50d8ae3SPaolo Bonzini } 3538c50d8ae3SPaolo Bonzini 3539c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3540c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3541c50d8ae3SPaolo Bonzini { 3542c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3543c50d8ae3SPaolo Bonzini 3544c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3545c50d8ae3SPaolo Bonzini return; 3546c50d8ae3SPaolo Bonzini 35475e3edd7eSSean Christopherson /* 35485e3edd7eSSean Christopherson * The "root" may be a special root, e.g. a PAE entry, treat it as a 35495e3edd7eSSean Christopherson * SPTE to ensure any non-PA bits are dropped. 35505e3edd7eSSean Christopherson */ 35515e3edd7eSSean Christopherson sp = spte_to_child_sp(*root_hpa); 355220ba462dSSean Christopherson if (WARN_ON_ONCE(!sp)) 35539191b8f0SPaolo Bonzini return; 355402c00b3aSBen Gardon 3555897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 35566103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 355776eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3558c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3559c50d8ae3SPaolo Bonzini 3560c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3561c50d8ae3SPaolo Bonzini } 3562c50d8ae3SPaolo Bonzini 3563c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 35640c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3565c50d8ae3SPaolo Bonzini ulong roots_to_free) 3566c50d8ae3SPaolo Bonzini { 3567c50d8ae3SPaolo Bonzini int i; 3568c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3569594bef79SPaolo Bonzini bool free_active_root; 3570c50d8ae3SPaolo Bonzini 3571f94db0c8SSean Christopherson WARN_ON_ONCE(roots_to_free & ~KVM_MMU_ROOTS_ALL); 3572f94db0c8SSean Christopherson 3573c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3574c50d8ae3SPaolo Bonzini 3575c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3576594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3577594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3578594bef79SPaolo Bonzini 3579594bef79SPaolo Bonzini if (!free_active_root) { 3580c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3581c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3582c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3583c50d8ae3SPaolo Bonzini break; 3584c50d8ae3SPaolo Bonzini 3585c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3586c50d8ae3SPaolo Bonzini return; 3587c50d8ae3SPaolo Bonzini } 3588c50d8ae3SPaolo Bonzini 3589531810caSBen Gardon write_lock(&kvm->mmu_lock); 3590c50d8ae3SPaolo Bonzini 3591c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3592c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 35934d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3594c50d8ae3SPaolo Bonzini &invalid_list); 3595c50d8ae3SPaolo Bonzini 3596c50d8ae3SPaolo Bonzini if (free_active_root) { 3597594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3598b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 359904d45551SSean Christopherson } else if (mmu->pae_root) { 3600c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3601c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3602c834e5e4SSean Christopherson continue; 3603c834e5e4SSean Christopherson 3604c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3605c50d8ae3SPaolo Bonzini &invalid_list); 3606c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3607c50d8ae3SPaolo Bonzini } 3608c50d8ae3SPaolo Bonzini } 3609b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3610b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3611c50d8ae3SPaolo Bonzini } 3612c50d8ae3SPaolo Bonzini 36134d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3614531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3615c50d8ae3SPaolo Bonzini } 3616c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3617c50d8ae3SPaolo Bonzini 36180c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 361925b62c62SSean Christopherson { 362025b62c62SSean Christopherson unsigned long roots_to_free = 0; 362125b62c62SSean Christopherson hpa_t root_hpa; 362225b62c62SSean Christopherson int i; 362325b62c62SSean Christopherson 362425b62c62SSean Christopherson /* 362525b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 362625b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 362725b62c62SSean Christopherson */ 36287a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 362925b62c62SSean Christopherson 363025b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 363125b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 363225b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 363325b62c62SSean Christopherson continue; 363425b62c62SSean Christopherson 363525b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 363625b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 363725b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 363825b62c62SSean Christopherson } 363925b62c62SSean Christopherson 36400c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 364125b62c62SSean Christopherson } 364225b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 364325b62c62SSean Christopherson 364425b62c62SSean Christopherson 3645c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3646c50d8ae3SPaolo Bonzini { 3647c50d8ae3SPaolo Bonzini int ret = 0; 3648c50d8ae3SPaolo Bonzini 3649995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3650c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3651c50d8ae3SPaolo Bonzini ret = 1; 3652c50d8ae3SPaolo Bonzini } 3653c50d8ae3SPaolo Bonzini 3654c50d8ae3SPaolo Bonzini return ret; 3655c50d8ae3SPaolo Bonzini } 3656c50d8ae3SPaolo Bonzini 36572e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 365886938ab6SDavid Matlack u8 level) 3659c50d8ae3SPaolo Bonzini { 36602e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3661c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 36628123f265SSean Christopherson 36632e65e842SDavid Matlack role.level = level; 36642e65e842SDavid Matlack role.quadrant = quadrant; 36652e65e842SDavid Matlack 36667f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 36677f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 36687f497775SDavid Matlack 366987654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 36708123f265SSean Christopherson ++sp->root_count; 36718123f265SSean Christopherson 36728123f265SSean Christopherson return __pa(sp->spt); 36738123f265SSean Christopherson } 36748123f265SSean Christopherson 36758123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 36768123f265SSean Christopherson { 3677b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3678a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 36798123f265SSean Christopherson hpa_t root; 3680c50d8ae3SPaolo Bonzini unsigned i; 36814a38162eSPaolo Bonzini int r; 36824a38162eSPaolo Bonzini 36834a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 36844a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 36854a38162eSPaolo Bonzini if (r < 0) 36864a38162eSPaolo Bonzini goto out_unlock; 3687c50d8ae3SPaolo Bonzini 36881f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 368902c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3690b9e5603cSPaolo Bonzini mmu->root.hpa = root; 369102c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 369286938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3693b9e5603cSPaolo Bonzini mmu->root.hpa = root; 36948123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 36954a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 36964a38162eSPaolo Bonzini r = -EIO; 36974a38162eSPaolo Bonzini goto out_unlock; 36984a38162eSPaolo Bonzini } 369973ad1606SSean Christopherson 3700c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3701c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3702c50d8ae3SPaolo Bonzini 37037f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 37042e65e842SDavid Matlack PT32_ROOT_LEVEL); 370517e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3706d2263de1SYuan Yao shadow_me_value; 3707c50d8ae3SPaolo Bonzini } 3708b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 370973ad1606SSean Christopherson } else { 371073ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 37114a38162eSPaolo Bonzini r = -EIO; 37124a38162eSPaolo Bonzini goto out_unlock; 371373ad1606SSean Christopherson } 37143651c7fcSSean Christopherson 3715b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3716b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 37174a38162eSPaolo Bonzini out_unlock: 37184a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 37194a38162eSPaolo Bonzini return r; 3720c50d8ae3SPaolo Bonzini } 3721c50d8ae3SPaolo Bonzini 37221e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 37231e76a3ceSDavid Stevens { 37241e76a3ceSDavid Stevens struct kvm_memslots *slots; 37251e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3726a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 37271e76a3ceSDavid Stevens 37281e76a3ceSDavid Stevens /* 37291e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 37301e76a3ceSDavid Stevens * taking the lock. 37311e76a3ceSDavid Stevens */ 37321e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37331e76a3ceSDavid Stevens return 0; 37341e76a3ceSDavid Stevens 37351e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 37361e76a3ceSDavid Stevens 37371e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 37381e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37391e76a3ceSDavid Stevens goto out_unlock; 37401e76a3ceSDavid Stevens 37411e76a3ceSDavid Stevens /* 37421e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 37431e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 37441e76a3ceSDavid Stevens */ 37451e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 37461e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 37471e76a3ceSDavid Stevens goto out_success; 37481e76a3ceSDavid Stevens 37491e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 37501e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3751a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 37521e76a3ceSDavid Stevens /* 37531e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 37541e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 37551e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 37561e76a3ceSDavid Stevens * failure to avoid having to track which allocations 37571e76a3ceSDavid Stevens * were made now versus when the memslot was created. 37581e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 37591e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 37601e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 37611e76a3ceSDavid Stevens */ 37621e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 37631e76a3ceSDavid Stevens if (r) 37641e76a3ceSDavid Stevens goto out_unlock; 37651e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 37661e76a3ceSDavid Stevens if (r) 37671e76a3ceSDavid Stevens goto out_unlock; 37681e76a3ceSDavid Stevens } 37691e76a3ceSDavid Stevens } 37701e76a3ceSDavid Stevens 37711e76a3ceSDavid Stevens /* 37721e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 37731e76a3ceSDavid Stevens * all the related pointers are set. 37741e76a3ceSDavid Stevens */ 37751e76a3ceSDavid Stevens out_success: 37761e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 37771e76a3ceSDavid Stevens 37781e76a3ceSDavid Stevens out_unlock: 37791e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 37801e76a3ceSDavid Stevens return r; 37811e76a3ceSDavid Stevens } 37821e76a3ceSDavid Stevens 3783c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3784c50d8ae3SPaolo Bonzini { 3785b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 37866e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3787be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 37887f497775SDavid Matlack int quadrant, i, r; 37898123f265SSean Christopherson hpa_t root; 3790c50d8ae3SPaolo Bonzini 37912fdcc1b3SPaolo Bonzini root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu); 3792be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3793c50d8ae3SPaolo Bonzini 3794c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3795c50d8ae3SPaolo Bonzini return 1; 3796c50d8ae3SPaolo Bonzini 3797c50d8ae3SPaolo Bonzini /* 37984a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 37994a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 38004a38162eSPaolo Bonzini */ 38014d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38026e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 38036e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 38046e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 38056e0918aeSSean Christopherson continue; 38066e0918aeSSean Christopherson 38076e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 38086e0918aeSSean Christopherson return 1; 38096e0918aeSSean Christopherson } 38106e0918aeSSean Christopherson } 38116e0918aeSSean Christopherson 38121e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3813d501f747SBen Gardon if (r) 3814d501f747SBen Gardon return r; 3815d501f747SBen Gardon 38164a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 38174a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 38184a38162eSPaolo Bonzini if (r < 0) 38194a38162eSPaolo Bonzini goto out_unlock; 38204a38162eSPaolo Bonzini 3821c50d8ae3SPaolo Bonzini /* 3822c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3823c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3824c50d8ae3SPaolo Bonzini */ 38254d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 38268123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 382786938ab6SDavid Matlack mmu->root_role.level); 3828b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3829be01e8e2SSean Christopherson goto set_root_pgd; 3830c50d8ae3SPaolo Bonzini } 3831c50d8ae3SPaolo Bonzini 38324a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 38334a38162eSPaolo Bonzini r = -EIO; 38344a38162eSPaolo Bonzini goto out_unlock; 38354a38162eSPaolo Bonzini } 383673ad1606SSean Christopherson 3837c50d8ae3SPaolo Bonzini /* 3838c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3839c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3840c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3841c50d8ae3SPaolo Bonzini */ 3842e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3843a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3844c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3845c50d8ae3SPaolo Bonzini 384603ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 38474a38162eSPaolo Bonzini r = -EIO; 38484a38162eSPaolo Bonzini goto out_unlock; 38494a38162eSPaolo Bonzini } 385003ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3851cb0f722aSWei Huang 3852a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3853cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3854cb0f722aSWei Huang r = -EIO; 3855cb0f722aSWei Huang goto out_unlock; 3856cb0f722aSWei Huang } 3857cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3858cb0f722aSWei Huang } 385904d45551SSean Christopherson } 386004d45551SSean Christopherson 3861c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3862c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 38636e6ec584SSean Christopherson 38644d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38656e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3866c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3867c50d8ae3SPaolo Bonzini continue; 3868c50d8ae3SPaolo Bonzini } 38696e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3870c50d8ae3SPaolo Bonzini } 3871c50d8ae3SPaolo Bonzini 38727f497775SDavid Matlack /* 38737f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 38747f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 38757f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 38767f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 38777f497775SDavid Matlack */ 38787f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 38797f497775SDavid Matlack 38807f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3881b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3882c50d8ae3SPaolo Bonzini } 3883c50d8ae3SPaolo Bonzini 3884a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3885b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3886a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3887b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3888ba0a194fSSean Christopherson else 3889b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3890c50d8ae3SPaolo Bonzini 3891be01e8e2SSean Christopherson set_root_pgd: 3892b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 38934a38162eSPaolo Bonzini out_unlock: 38944a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3895c50d8ae3SPaolo Bonzini 3896c6c937d6SLike Xu return r; 3897c50d8ae3SPaolo Bonzini } 3898c50d8ae3SPaolo Bonzini 3899748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3900c50d8ae3SPaolo Bonzini { 3901748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3902a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3903cb0f722aSWei Huang u64 *pml5_root = NULL; 3904cb0f722aSWei Huang u64 *pml4_root = NULL; 3905cb0f722aSWei Huang u64 *pae_root; 3906748e52b9SSean Christopherson 3907748e52b9SSean Christopherson /* 3908748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3909748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3910748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3911748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3912748e52b9SSean Christopherson */ 3913347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3914347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3915a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3916748e52b9SSean Christopherson return 0; 3917748e52b9SSean Christopherson 3918a717a780SSean Christopherson /* 3919a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3920a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3921a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3922a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3923a717a780SSean Christopherson * prior MMU would also have required pml5. 3924a717a780SSean Christopherson */ 3925a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3926748e52b9SSean Christopherson return 0; 3927748e52b9SSean Christopherson 3928748e52b9SSean Christopherson /* 3929748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3930748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3931748e52b9SSean Christopherson */ 3932cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3933a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3934748e52b9SSean Christopherson return -EIO; 3935748e52b9SSean Christopherson 39364a98623dSSean Christopherson /* 39374a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 39384a98623dSSean Christopherson * doesn't need to be decrypted. 39394a98623dSSean Christopherson */ 3940748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3941748e52b9SSean Christopherson if (!pae_root) 3942748e52b9SSean Christopherson return -ENOMEM; 3943748e52b9SSean Christopherson 3944cb0f722aSWei Huang #ifdef CONFIG_X86_64 394503ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3946cb0f722aSWei Huang if (!pml4_root) 3947cb0f722aSWei Huang goto err_pml4; 3948cb0f722aSWei Huang 3949a717a780SSean Christopherson if (need_pml5) { 3950cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3951cb0f722aSWei Huang if (!pml5_root) 3952cb0f722aSWei Huang goto err_pml5; 3953748e52b9SSean Christopherson } 3954cb0f722aSWei Huang #endif 3955748e52b9SSean Christopherson 3956748e52b9SSean Christopherson mmu->pae_root = pae_root; 395703ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3958cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3959748e52b9SSean Christopherson 3960748e52b9SSean Christopherson return 0; 3961cb0f722aSWei Huang 3962cb0f722aSWei Huang #ifdef CONFIG_X86_64 3963cb0f722aSWei Huang err_pml5: 3964cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3965cb0f722aSWei Huang err_pml4: 3966cb0f722aSWei Huang free_page((unsigned long)pae_root); 3967cb0f722aSWei Huang return -ENOMEM; 3968cb0f722aSWei Huang #endif 3969c50d8ae3SPaolo Bonzini } 3970c50d8ae3SPaolo Bonzini 3971264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3972264d3dc1SLai Jiangshan { 3973264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 3974264d3dc1SLai Jiangshan 397561b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 397661b05a9fSLai Jiangshan return false; 397761b05a9fSLai Jiangshan 3978264d3dc1SLai Jiangshan /* 3979264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 3980264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 3981264d3dc1SLai Jiangshan * 3982264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 3983264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 3984264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 3985264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 3986264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 3987264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 3988264d3dc1SLai Jiangshan * requirement isn't satisfied. 3989264d3dc1SLai Jiangshan */ 3990264d3dc1SLai Jiangshan smp_rmb(); 3991264d3dc1SLai Jiangshan sp = to_shadow_page(root); 39925d6a3221SSean Christopherson 39935d6a3221SSean Christopherson /* 39945d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 39955d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 39965d6a3221SSean Christopherson */ 39975d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 39985d6a3221SSean Christopherson return false; 39995d6a3221SSean Christopherson 4000264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 4001264d3dc1SLai Jiangshan return true; 4002264d3dc1SLai Jiangshan 4003264d3dc1SLai Jiangshan return false; 4004264d3dc1SLai Jiangshan } 4005264d3dc1SLai Jiangshan 4006c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 4007c50d8ae3SPaolo Bonzini { 4008c50d8ae3SPaolo Bonzini int i; 4009c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 4010c50d8ae3SPaolo Bonzini 4011347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 4012c50d8ae3SPaolo Bonzini return; 4013c50d8ae3SPaolo Bonzini 4014b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 4015c50d8ae3SPaolo Bonzini return; 4016c50d8ae3SPaolo Bonzini 4017c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4018c50d8ae3SPaolo Bonzini 40194d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 4020b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 4021e47c4aeeSSean Christopherson sp = to_shadow_page(root); 4022c50d8ae3SPaolo Bonzini 4023264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 4024c50d8ae3SPaolo Bonzini return; 4025c50d8ae3SPaolo Bonzini 4026531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 402765855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4028531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4029c50d8ae3SPaolo Bonzini return; 4030c50d8ae3SPaolo Bonzini } 4031c50d8ae3SPaolo Bonzini 4032531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4033c50d8ae3SPaolo Bonzini 4034c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 4035c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 4036c50d8ae3SPaolo Bonzini 4037c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 40385e3edd7eSSean Christopherson sp = spte_to_child_sp(root); 403965855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4040c50d8ae3SPaolo Bonzini } 4041c50d8ae3SPaolo Bonzini } 4042c50d8ae3SPaolo Bonzini 4043531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4044c50d8ae3SPaolo Bonzini } 4045c50d8ae3SPaolo Bonzini 404661b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 404761b05a9fSLai Jiangshan { 404861b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 404961b05a9fSLai Jiangshan int i; 405061b05a9fSLai Jiangshan 405161b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 405261b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 405361b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 405461b05a9fSLai Jiangshan 405561b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 40560c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 405761b05a9fSLai Jiangshan } 405861b05a9fSLai Jiangshan 40591f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 40605b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 4061c50d8ae3SPaolo Bonzini struct x86_exception *exception) 4062c50d8ae3SPaolo Bonzini { 4063c50d8ae3SPaolo Bonzini if (exception) 4064c50d8ae3SPaolo Bonzini exception->error_code = 0; 4065c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 4066c50d8ae3SPaolo Bonzini } 4067c50d8ae3SPaolo Bonzini 4068c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4069c50d8ae3SPaolo Bonzini { 4070c50d8ae3SPaolo Bonzini /* 4071c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 4072c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 4073c50d8ae3SPaolo Bonzini */ 4074c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 4075c50d8ae3SPaolo Bonzini return false; 4076c50d8ae3SPaolo Bonzini 4077c50d8ae3SPaolo Bonzini if (direct) 4078c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 4079c50d8ae3SPaolo Bonzini 4080c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 4081c50d8ae3SPaolo Bonzini } 4082c50d8ae3SPaolo Bonzini 408395fb5b02SBen Gardon /* 408495fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 408595fb5b02SBen Gardon * That SPTE may be non-present. 4086c5c8c7c5SDavid Matlack * 4087c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 408895fb5b02SBen Gardon */ 408939b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 4090c50d8ae3SPaolo Bonzini { 4091c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 40922aa07893SSean Christopherson int leaf = -1; 409395fb5b02SBen Gardon u64 spte; 4094c50d8ae3SPaolo Bonzini 409539b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 409639b4d43eSSean Christopherson *root_level = iterator.level; 4097c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 4098c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 409995fb5b02SBen Gardon leaf = iterator.level; 4100c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 4101c50d8ae3SPaolo Bonzini 4102dde81f94SSean Christopherson sptes[leaf] = spte; 410395fb5b02SBen Gardon } 410495fb5b02SBen Gardon 410595fb5b02SBen Gardon return leaf; 410695fb5b02SBen Gardon } 410795fb5b02SBen Gardon 41089aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 410995fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 411095fb5b02SBen Gardon { 4111dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 411295fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 411339b4d43eSSean Christopherson int root, leaf, level; 411495fb5b02SBen Gardon bool reserved = false; 411595fb5b02SBen Gardon 4116c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 4117c5c8c7c5SDavid Matlack 411878fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) 411939b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 412095fb5b02SBen Gardon else 412139b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 412295fb5b02SBen Gardon 4123c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 4124c5c8c7c5SDavid Matlack 41252aa07893SSean Christopherson if (unlikely(leaf < 0)) { 41262aa07893SSean Christopherson *sptep = 0ull; 41272aa07893SSean Christopherson return reserved; 41282aa07893SSean Christopherson } 41292aa07893SSean Christopherson 41309aa41879SSean Christopherson *sptep = sptes[leaf]; 41319aa41879SSean Christopherson 41329aa41879SSean Christopherson /* 41339aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 41349aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 41359aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 41369aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 41379aa41879SSean Christopherson */ 41389aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 41399aa41879SSean Christopherson leaf++; 414095fb5b02SBen Gardon 414195fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 414295fb5b02SBen Gardon 41439aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4144961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4145c50d8ae3SPaolo Bonzini 4146c50d8ae3SPaolo Bonzini if (reserved) { 4147bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4148c50d8ae3SPaolo Bonzini __func__, addr); 414995fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4150bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4151bb4cdf3aSSean Christopherson sptes[level], level, 4152961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4153c50d8ae3SPaolo Bonzini } 4154ddce6208SSean Christopherson 4155c50d8ae3SPaolo Bonzini return reserved; 4156c50d8ae3SPaolo Bonzini } 4157c50d8ae3SPaolo Bonzini 4158c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4159c50d8ae3SPaolo Bonzini { 4160c50d8ae3SPaolo Bonzini u64 spte; 4161c50d8ae3SPaolo Bonzini bool reserved; 4162c50d8ae3SPaolo Bonzini 4163c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4164c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4165c50d8ae3SPaolo Bonzini 416695fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 416720ba462dSSean Christopherson if (WARN_ON_ONCE(reserved)) 4168c50d8ae3SPaolo Bonzini return -EINVAL; 4169c50d8ae3SPaolo Bonzini 4170c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4171c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 41720a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4173c50d8ae3SPaolo Bonzini 4174c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4175c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4176c50d8ae3SPaolo Bonzini 4177c50d8ae3SPaolo Bonzini if (direct) 4178c50d8ae3SPaolo Bonzini addr = 0; 4179c50d8ae3SPaolo Bonzini 4180c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4181c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4182c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4183c50d8ae3SPaolo Bonzini } 4184c50d8ae3SPaolo Bonzini 4185c50d8ae3SPaolo Bonzini /* 4186c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4187c50d8ae3SPaolo Bonzini * the address. 4188c50d8ae3SPaolo Bonzini */ 4189c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4190c50d8ae3SPaolo Bonzini } 4191c50d8ae3SPaolo Bonzini 4192c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4193b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4194c50d8ae3SPaolo Bonzini { 4195b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4196c50d8ae3SPaolo Bonzini return false; 4197c50d8ae3SPaolo Bonzini 4198b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4199c50d8ae3SPaolo Bonzini return false; 4200c50d8ae3SPaolo Bonzini 4201c50d8ae3SPaolo Bonzini /* 4202c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4203c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4204c50d8ae3SPaolo Bonzini */ 42059d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 4206c50d8ae3SPaolo Bonzini return true; 4207c50d8ae3SPaolo Bonzini 4208c50d8ae3SPaolo Bonzini return false; 4209c50d8ae3SPaolo Bonzini } 4210c50d8ae3SPaolo Bonzini 4211c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4212c50d8ae3SPaolo Bonzini { 4213c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4214c50d8ae3SPaolo Bonzini u64 spte; 4215c50d8ae3SPaolo Bonzini 4216c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 42173e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4218c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4219c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4220c50d8ae3SPaolo Bonzini } 4221c50d8ae3SPaolo Bonzini 42226f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 42236f3c1fc5SLiang Zhang { 42246f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 42256f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 42266f3c1fc5SLiang Zhang 42276f3c1fc5SLiang Zhang if (id << 12 == 0) 42286f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 42296f3c1fc5SLiang Zhang 42306f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 42316f3c1fc5SLiang Zhang } 42326f3c1fc5SLiang Zhang 4233e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 42349f1a8526SSean Christopherson gfn_t gfn) 4235c50d8ae3SPaolo Bonzini { 4236c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4237c50d8ae3SPaolo Bonzini 42386f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4239c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4240347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 42412fdcc1b3SPaolo Bonzini arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu); 4242c50d8ae3SPaolo Bonzini 42439f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 42449f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4245c50d8ae3SPaolo Bonzini } 4246c50d8ae3SPaolo Bonzini 42478a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 42488a009d5bSSean Christopherson { 42498a009d5bSSean Christopherson int r; 42508a009d5bSSean Christopherson 42518a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 42528a009d5bSSean Christopherson work->wakeup_all) 42538a009d5bSSean Christopherson return; 42548a009d5bSSean Christopherson 42558a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 42568a009d5bSSean Christopherson if (unlikely(r)) 42578a009d5bSSean Christopherson return; 42588a009d5bSSean Christopherson 42598a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 42602fdcc1b3SPaolo Bonzini work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu)) 42618a009d5bSSean Christopherson return; 42628a009d5bSSean Christopherson 4263258d985fSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true, NULL); 42648a009d5bSSean Christopherson } 42658a009d5bSSean Christopherson 4266ba6e3fe2SDavid Matlack static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4267c50d8ae3SPaolo Bonzini { 4268e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4269c50d8ae3SPaolo Bonzini bool async; 4270c50d8ae3SPaolo Bonzini 4271e0c37868SSean Christopherson /* 4272e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4273e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4274e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4275e0c37868SSean Christopherson */ 4276e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 42775276c616SSean Christopherson return RET_PF_RETRY; 4278e0c37868SSean Christopherson 42799cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4280c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 42819cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4282e710c5f6SDavid Matlack fault->slot = NULL; 42833647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 42843647cd04SPaolo Bonzini fault->map_writable = false; 42855276c616SSean Christopherson return RET_PF_CONTINUE; 4286c50d8ae3SPaolo Bonzini } 42879cc13d60SMaxim Levitsky /* 42889cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 42899cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 42909cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 42919cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 42929cc13d60SMaxim Levitsky */ 42939cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 42945276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 42955276c616SSean Christopherson return RET_PF_EMULATE; 42969cc13d60SMaxim Levitsky } 4297c50d8ae3SPaolo Bonzini 4298c50d8ae3SPaolo Bonzini async = false; 4299c8b88b33SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, 43003647cd04SPaolo Bonzini fault->write, &fault->map_writable, 43013647cd04SPaolo Bonzini &fault->hva); 4302c50d8ae3SPaolo Bonzini if (!async) 43035276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4304c50d8ae3SPaolo Bonzini 43052839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 43063647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 43073647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 43081685c0f3SMingwei Zhang trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4309c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 43105276c616SSean Christopherson return RET_PF_RETRY; 43115276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 43125276c616SSean Christopherson return RET_PF_RETRY; 43135276c616SSean Christopherson } 4314c50d8ae3SPaolo Bonzini } 4315c50d8ae3SPaolo Bonzini 431676657687SPeter Xu /* 431776657687SPeter Xu * Allow gup to bail on pending non-fatal signals when it's also allowed 431876657687SPeter Xu * to wait for IO. Note, gup always bails if it is unable to quickly 431976657687SPeter Xu * get a page and a fatal signal, i.e. SIGKILL, is pending. 432076657687SPeter Xu */ 432176657687SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, 43223647cd04SPaolo Bonzini fault->write, &fault->map_writable, 43233647cd04SPaolo Bonzini &fault->hva); 43245276c616SSean Christopherson return RET_PF_CONTINUE; 4325c50d8ae3SPaolo Bonzini } 4326c50d8ae3SPaolo Bonzini 4327354c908cSDavid Matlack static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 4328354c908cSDavid Matlack unsigned int access) 4329ba6e3fe2SDavid Matlack { 433056c3a4e4SDavid Matlack int ret; 433156c3a4e4SDavid Matlack 4332ba6e3fe2SDavid Matlack fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4333ba6e3fe2SDavid Matlack smp_rmb(); 4334ba6e3fe2SDavid Matlack 433556c3a4e4SDavid Matlack ret = __kvm_faultin_pfn(vcpu, fault); 433656c3a4e4SDavid Matlack if (ret != RET_PF_CONTINUE) 433756c3a4e4SDavid Matlack return ret; 433856c3a4e4SDavid Matlack 433956c3a4e4SDavid Matlack if (unlikely(is_error_pfn(fault->pfn))) 4340cd08d178SDavid Matlack return kvm_handle_error_pfn(vcpu, fault); 434156c3a4e4SDavid Matlack 4342354c908cSDavid Matlack if (unlikely(!fault->slot)) 4343354c908cSDavid Matlack return kvm_handle_noslot_fault(vcpu, fault, access); 4344354c908cSDavid Matlack 434556c3a4e4SDavid Matlack return RET_PF_CONTINUE; 4346ba6e3fe2SDavid Matlack } 4347ba6e3fe2SDavid Matlack 4348a955cad8SSean Christopherson /* 4349a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4350a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4351a955cad8SSean Christopherson */ 4352a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4353ba6e3fe2SDavid Matlack struct kvm_page_fault *fault) 4354a955cad8SSean Christopherson { 4355b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 435618c841e1SSean Christopherson 435718c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 435818c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 435918c841e1SSean Christopherson return true; 436018c841e1SSean Christopherson 436118c841e1SSean Christopherson /* 436218c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 436318c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 436418c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 436518c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 436618c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 436718c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 436818c841e1SSean Christopherson */ 4369527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4370a955cad8SSean Christopherson return true; 4371a955cad8SSean Christopherson 4372a955cad8SSean Christopherson return fault->slot && 4373ba6e3fe2SDavid Matlack mmu_invalidate_retry_hva(vcpu->kvm, fault->mmu_seq, fault->hva); 4374a955cad8SSean Christopherson } 4375a955cad8SSean Christopherson 43764326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4377c50d8ae3SPaolo Bonzini { 437883f06fa7SSean Christopherson int r; 4379c50d8ae3SPaolo Bonzini 4380b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4381c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4382c50d8ae3SPaolo Bonzini 43833c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4384c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4385c4371c2aSSean Christopherson return r; 438683291445SSean Christopherson 4387378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4388c50d8ae3SPaolo Bonzini if (r) 4389c50d8ae3SPaolo Bonzini return r; 4390c50d8ae3SPaolo Bonzini 4391354c908cSDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 43925276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4393367fd790SSean Christopherson return r; 4394367fd790SSean Christopherson 4395367fd790SSean Christopherson r = RET_PF_RETRY; 4396531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4397a2855afcSBen Gardon 4398ba6e3fe2SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 4399367fd790SSean Christopherson goto out_unlock; 4400a955cad8SSean Christopherson 44017bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 44027bd7ded6SSean Christopherson if (r) 4403367fd790SSean Christopherson goto out_unlock; 4404bb18842eSBen Gardon 44056c882ef4SDavid Matlack r = direct_map(vcpu, fault); 44060f90e1c1SSean Christopherson 4407367fd790SSean Christopherson out_unlock: 4408531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 44093647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4410367fd790SSean Christopherson return r; 4411c50d8ae3SPaolo Bonzini } 4412c50d8ae3SPaolo Bonzini 4413c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4414c501040aSPaolo Bonzini struct kvm_page_fault *fault) 44150f90e1c1SSean Christopherson { 44160f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 44174326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 44184326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 44190f90e1c1SSean Christopherson } 44200f90e1c1SSean Christopherson 4421c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4422c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4423c50d8ae3SPaolo Bonzini { 4424c50d8ae3SPaolo Bonzini int r = 1; 44259ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4426c50d8ae3SPaolo Bonzini 4427736c291cSSean Christopherson #ifndef CONFIG_X86_64 4428736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4429736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4430736c291cSSean Christopherson return -EFAULT; 4431736c291cSSean Christopherson #endif 4432736c291cSSean Christopherson 4433c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 44349ce372b3SVitaly Kuznetsov if (!flags) { 4435faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4436c50d8ae3SPaolo Bonzini 4437c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4438c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4439c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4440c50d8ae3SPaolo Bonzini insn_len); 44419ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 444268fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4443c50d8ae3SPaolo Bonzini local_irq_disable(); 44446bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4445c50d8ae3SPaolo Bonzini local_irq_enable(); 44469ce372b3SVitaly Kuznetsov } else { 44479ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4448c50d8ae3SPaolo Bonzini } 44499ce372b3SVitaly Kuznetsov 4450c50d8ae3SPaolo Bonzini return r; 4451c50d8ae3SPaolo Bonzini } 4452c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4453c50d8ae3SPaolo Bonzini 44549aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 44559aa8ab43SDavid Matlack static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, 44569aa8ab43SDavid Matlack struct kvm_page_fault *fault) 44579aa8ab43SDavid Matlack { 44589aa8ab43SDavid Matlack int r; 44599aa8ab43SDavid Matlack 44609aa8ab43SDavid Matlack if (page_fault_handle_page_track(vcpu, fault)) 44619aa8ab43SDavid Matlack return RET_PF_EMULATE; 44629aa8ab43SDavid Matlack 44639aa8ab43SDavid Matlack r = fast_page_fault(vcpu, fault); 44649aa8ab43SDavid Matlack if (r != RET_PF_INVALID) 44659aa8ab43SDavid Matlack return r; 44669aa8ab43SDavid Matlack 44679aa8ab43SDavid Matlack r = mmu_topup_memory_caches(vcpu, false); 44689aa8ab43SDavid Matlack if (r) 44699aa8ab43SDavid Matlack return r; 44709aa8ab43SDavid Matlack 44719aa8ab43SDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 44729aa8ab43SDavid Matlack if (r != RET_PF_CONTINUE) 44739aa8ab43SDavid Matlack return r; 44749aa8ab43SDavid Matlack 44759aa8ab43SDavid Matlack r = RET_PF_RETRY; 44769aa8ab43SDavid Matlack read_lock(&vcpu->kvm->mmu_lock); 44779aa8ab43SDavid Matlack 44789aa8ab43SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 44799aa8ab43SDavid Matlack goto out_unlock; 44809aa8ab43SDavid Matlack 44819aa8ab43SDavid Matlack r = kvm_tdp_mmu_map(vcpu, fault); 44829aa8ab43SDavid Matlack 44839aa8ab43SDavid Matlack out_unlock: 44849aa8ab43SDavid Matlack read_unlock(&vcpu->kvm->mmu_lock); 44859aa8ab43SDavid Matlack kvm_release_pfn_clean(fault->pfn); 44869aa8ab43SDavid Matlack return r; 44879aa8ab43SDavid Matlack } 44889aa8ab43SDavid Matlack #endif 44899aa8ab43SDavid Matlack 4490c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4491c50d8ae3SPaolo Bonzini { 4492d5e90a69SSean Christopherson /* 4493d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4494d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 4495d5e90a69SSean Christopherson * across the entire mapping. If the host MTRRs are ignored by TDP 4496d5e90a69SSean Christopherson * (shadow_memtype_mask is non-zero), and the VM has non-coherent DMA 4497d5e90a69SSean Christopherson * (DMA doesn't snoop CPU caches), KVM's ABI is to honor the memtype 4498d5e90a69SSean Christopherson * from the guest's MTRRs so that guest accesses to memory that is 4499d5e90a69SSean Christopherson * DMA'd aren't cached against the guest's wishes. 4500d5e90a69SSean Christopherson * 4501d5e90a69SSean Christopherson * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 4502d5e90a69SSean Christopherson * e.g. KVM will force UC memtype for host MMIO. 4503d5e90a69SSean Christopherson */ 4504d5e90a69SSean Christopherson if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) { 4505d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 45064326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 4507c667a3baSHou Wenlong gfn_t base = gfn_round_for_level(fault->gfn, 4508c667a3baSHou Wenlong fault->max_level); 4509c50d8ae3SPaolo Bonzini 4510cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4511cb9b88c6SSean Christopherson break; 4512d5e90a69SSean Christopherson } 4513c50d8ae3SPaolo Bonzini } 4514c50d8ae3SPaolo Bonzini 45159aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 45169aa8ab43SDavid Matlack if (tdp_mmu_enabled) 45179aa8ab43SDavid Matlack return kvm_tdp_mmu_page_fault(vcpu, fault); 45189aa8ab43SDavid Matlack #endif 45199aa8ab43SDavid Matlack 45204326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4521c50d8ae3SPaolo Bonzini } 4522c50d8ae3SPaolo Bonzini 452384a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4524c50d8ae3SPaolo Bonzini { 4525c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4526c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4527c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 4528c50d8ae3SPaolo Bonzini } 4529c50d8ae3SPaolo Bonzini 4530be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 45310be44352SSean Christopherson union kvm_mmu_page_role role) 45320be44352SSean Christopherson { 4533be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 45345499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4535e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 45360be44352SSean Christopherson } 45370be44352SSean Christopherson 4538c50d8ae3SPaolo Bonzini /* 45395499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 45405499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 45415499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 45425499ea73SPaolo Bonzini * true is returned. 45435499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 45445499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4545c50d8ae3SPaolo Bonzini */ 45465499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 45475499ea73SPaolo Bonzini gpa_t new_pgd, 4548c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4549c50d8ae3SPaolo Bonzini { 4550c50d8ae3SPaolo Bonzini uint i; 4551c50d8ae3SPaolo Bonzini 4552b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 45530be44352SSean Christopherson return true; 45540be44352SSean Christopherson 4555c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 45565499ea73SPaolo Bonzini /* 45575499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 45585499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 45595499ea73SPaolo Bonzini * 0 C 1 2 3 45605499ea73SPaolo Bonzini * 1 C 0 2 3 45615499ea73SPaolo Bonzini * 2 C 0 1 3 45625499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 45635499ea73SPaolo Bonzini */ 4564b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4565b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 45665499ea73SPaolo Bonzini return true; 4567c50d8ae3SPaolo Bonzini } 4568c50d8ae3SPaolo Bonzini 45695499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 45705499ea73SPaolo Bonzini return false; 4571c50d8ae3SPaolo Bonzini } 4572c50d8ae3SPaolo Bonzini 4573c50d8ae3SPaolo Bonzini /* 45745499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 45755499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 45765499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 45775499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 45785499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 45795499ea73SPaolo Bonzini */ 45805499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 45815499ea73SPaolo Bonzini gpa_t new_pgd, 45825499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 45835499ea73SPaolo Bonzini { 45845499ea73SPaolo Bonzini uint i; 45855499ea73SPaolo Bonzini 45865499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 45875499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 45885499ea73SPaolo Bonzini goto hit; 45895499ea73SPaolo Bonzini 45905499ea73SPaolo Bonzini return false; 45915499ea73SPaolo Bonzini 45925499ea73SPaolo Bonzini hit: 45935499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 45945499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 45955499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 45965499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 45975499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 45985499ea73SPaolo Bonzini return true; 45995499ea73SPaolo Bonzini } 46005499ea73SPaolo Bonzini 46015499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 46025499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 46035499ea73SPaolo Bonzini { 46045499ea73SPaolo Bonzini /* 46055499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4606c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4607c50d8ae3SPaolo Bonzini * later if necessary. 4608c50d8ae3SPaolo Bonzini */ 46095499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 46105499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4611c50d8ae3SPaolo Bonzini 46125499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 46135499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 46145499ea73SPaolo Bonzini else 46155499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4616c50d8ae3SPaolo Bonzini } 4617c50d8ae3SPaolo Bonzini 4618d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4619c50d8ae3SPaolo Bonzini { 46200c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 46217a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 46220c1c92f1SPaolo Bonzini 4623a7e48ef7SWei Liu /* 4624a7e48ef7SWei Liu * Return immediately if no usable root was found, kvm_mmu_reload() 4625a7e48ef7SWei Liu * will establish a valid root prior to the next VM-Enter. 4626a7e48ef7SWei Liu */ 4627a7e48ef7SWei Liu if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) 4628b869855bSSean Christopherson return; 4629c50d8ae3SPaolo Bonzini 4630c50d8ae3SPaolo Bonzini /* 4631b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4632b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4633527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4634527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4635b869855bSSean Christopherson */ 4636b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4637b869855bSSean Christopherson 4638b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4639b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4640b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4641b5129100SSean Christopherson } 4642b869855bSSean Christopherson 4643b869855bSSean Christopherson /* 4644b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4645b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4646b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4647b869855bSSean Christopherson * the shadow page tables. 4648c50d8ae3SPaolo Bonzini */ 4649c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4650c50d8ae3SPaolo Bonzini 4651daa5b6c1SBen Gardon /* 4652daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4653daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4654daa5b6c1SBen Gardon */ 4655daa5b6c1SBen Gardon if (!new_role.direct) 4656daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4657b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4658c50d8ae3SPaolo Bonzini } 4659be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4660c50d8ae3SPaolo Bonzini 4661c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4662c3e5e415SLai Jiangshan unsigned int access) 4663c50d8ae3SPaolo Bonzini { 4664c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4665c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4666c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4667c50d8ae3SPaolo Bonzini return true; 4668c50d8ae3SPaolo Bonzini } 4669c50d8ae3SPaolo Bonzini 4670c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4671c50d8ae3SPaolo Bonzini return true; 4672c50d8ae3SPaolo Bonzini } 4673c50d8ae3SPaolo Bonzini 4674c50d8ae3SPaolo Bonzini return false; 4675c50d8ae3SPaolo Bonzini } 4676c50d8ae3SPaolo Bonzini 4677c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4678c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4679c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4680c50d8ae3SPaolo Bonzini #undef PTTYPE 4681c50d8ae3SPaolo Bonzini 4682c50d8ae3SPaolo Bonzini #define PTTYPE 64 4683c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4684c50d8ae3SPaolo Bonzini #undef PTTYPE 4685c50d8ae3SPaolo Bonzini 4686c50d8ae3SPaolo Bonzini #define PTTYPE 32 4687c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4688c50d8ae3SPaolo Bonzini #undef PTTYPE 4689c50d8ae3SPaolo Bonzini 4690f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 4691f3d90f90SSean Christopherson u64 pa_bits_rsvd, int level, bool nx, 4692f3d90f90SSean Christopherson bool gbpages, bool pse, bool amd) 4693c50d8ae3SPaolo Bonzini { 4694c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4695c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 46965b7f575cSSean Christopherson u64 high_bits_rsvd; 4697c50d8ae3SPaolo Bonzini 4698c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4699c50d8ae3SPaolo Bonzini 4700c50d8ae3SPaolo Bonzini if (!gbpages) 4701c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4702c50d8ae3SPaolo Bonzini 47035b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 47045b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 47055b7f575cSSean Christopherson else 47065b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 47075b7f575cSSean Christopherson 47085b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 47095b7f575cSSean Christopherson if (!nx) 47105b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 47115b7f575cSSean Christopherson 4712c50d8ae3SPaolo Bonzini /* 4713c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4714c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4715c50d8ae3SPaolo Bonzini */ 4716c50d8ae3SPaolo Bonzini if (amd) 4717c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4718c50d8ae3SPaolo Bonzini 4719c50d8ae3SPaolo Bonzini switch (level) { 4720c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4721c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4722c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4723c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4724c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4725c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4726c50d8ae3SPaolo Bonzini 4727c50d8ae3SPaolo Bonzini if (!pse) { 4728c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4729c50d8ae3SPaolo Bonzini break; 4730c50d8ae3SPaolo Bonzini } 4731c50d8ae3SPaolo Bonzini 4732c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4733c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4734c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4735c50d8ae3SPaolo Bonzini else 4736c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4737c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4738c50d8ae3SPaolo Bonzini break; 4739c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 47405b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 47415b7f575cSSean Christopherson high_bits_rsvd | 47425b7f575cSSean Christopherson rsvd_bits(5, 8) | 47435b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 47445b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 47455b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 47465b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4747c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4748c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4749c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4750c50d8ae3SPaolo Bonzini break; 4751c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 47525b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 47535b7f575cSSean Christopherson nonleaf_bit8_rsvd | 47545b7f575cSSean Christopherson rsvd_bits(7, 7); 4755c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4756c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4757df561f66SGustavo A. R. Silva fallthrough; 4758c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 47595b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 47605b7f575cSSean Christopherson nonleaf_bit8_rsvd | 47615b7f575cSSean Christopherson rsvd_bits(7, 7); 47625b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 47635b7f575cSSean Christopherson gbpages_bit_rsvd; 47645b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 47655b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4766c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4767c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 47685b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 47695b7f575cSSean Christopherson gbpages_bit_rsvd | 4770c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 47715b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4772c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4773c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4774c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4775c50d8ae3SPaolo Bonzini break; 4776c50d8ae3SPaolo Bonzini } 4777c50d8ae3SPaolo Bonzini } 4778c50d8ae3SPaolo Bonzini 4779c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4780c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4781c50d8ae3SPaolo Bonzini { 4782b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 47835b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 47844d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 4785ccf31d6eSSean Christopherson guest_can_use(vcpu, X86_FEATURE_GBPAGES), 47864e9c0d80SSean Christopherson is_cr4_pse(context), 478723493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4788c50d8ae3SPaolo Bonzini } 4789c50d8ae3SPaolo Bonzini 4790f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 4791f3d90f90SSean Christopherson u64 pa_bits_rsvd, bool execonly, 4792f3d90f90SSean Christopherson int huge_page_level) 4793c50d8ae3SPaolo Bonzini { 47945b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 479584ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4796c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4797c50d8ae3SPaolo Bonzini 479884ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 479984ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 480084ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 480184ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 480284ea5c09SLai Jiangshan 48035b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 48045b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 480584ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 480684ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 48075b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4808c50d8ae3SPaolo Bonzini 4809c50d8ae3SPaolo Bonzini /* large page */ 4810c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4811c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 481284ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 481384ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4814c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4815c50d8ae3SPaolo Bonzini 4816c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4817c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4818c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4819c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4820c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4821c50d8ae3SPaolo Bonzini if (!execonly) { 4822c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4823c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4824c50d8ae3SPaolo Bonzini } 4825c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4826c50d8ae3SPaolo Bonzini } 4827c50d8ae3SPaolo Bonzini 4828c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 482984ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4830c50d8ae3SPaolo Bonzini { 4831c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 483284ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 483384ea5c09SLai Jiangshan huge_page_level); 4834c50d8ae3SPaolo Bonzini } 4835c50d8ae3SPaolo Bonzini 48366f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 48376f8e65a6SSean Christopherson { 48386f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 48396f8e65a6SSean Christopherson } 48406f8e65a6SSean Christopherson 4841c50d8ae3SPaolo Bonzini /* 4842c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4843c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4844c50d8ae3SPaolo Bonzini * follow the features in guest. 4845c50d8ae3SPaolo Bonzini */ 484616be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 484716be1d12SSean Christopherson struct kvm_mmu *context) 4848c50d8ae3SPaolo Bonzini { 48498c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 48508c985b2dSSean Christopherson bool is_amd = true; 48518c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 48528c985b2dSSean Christopherson bool is_pse = false; 4853c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4854c50d8ae3SPaolo Bonzini int i; 4855c50d8ae3SPaolo Bonzini 4856a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 48578c985b2dSSean Christopherson 4858c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4859b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4860a972e29cSPaolo Bonzini context->root_role.level, 48617a458f0eSPaolo Bonzini context->root_role.efer_nx, 4862ccf31d6eSSean Christopherson guest_can_use(vcpu, X86_FEATURE_GBPAGES), 4863ccf31d6eSSean Christopherson is_pse, is_amd); 4864c50d8ae3SPaolo Bonzini 4865c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4866c50d8ae3SPaolo Bonzini return; 4867c50d8ae3SPaolo Bonzini 4868a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4869e54f1ff2SKai Huang /* 4870e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4871e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4872e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4873e54f1ff2SKai Huang * not allowed to be set. 4874e54f1ff2SKai Huang */ 4875e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4876e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4877e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4878e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4879c50d8ae3SPaolo Bonzini } 4880c50d8ae3SPaolo Bonzini 4881c50d8ae3SPaolo Bonzini } 4882c50d8ae3SPaolo Bonzini 4883c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4884c50d8ae3SPaolo Bonzini { 4885c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4886c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4887c50d8ae3SPaolo Bonzini } 4888c50d8ae3SPaolo Bonzini 4889c50d8ae3SPaolo Bonzini /* 4890c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4891c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4892c50d8ae3SPaolo Bonzini */ 4893f3d90f90SSean Christopherson static void reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4894c50d8ae3SPaolo Bonzini { 4895c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4896c50d8ae3SPaolo Bonzini int i; 4897c50d8ae3SPaolo Bonzini 4898c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4899c50d8ae3SPaolo Bonzini 4900c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4901b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 49026c6ab524SSean Christopherson context->root_role.level, true, 4903c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 49048c985b2dSSean Christopherson false, true); 4905c50d8ae3SPaolo Bonzini else 4906c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 490784ea5c09SLai Jiangshan reserved_hpa_bits(), false, 490884ea5c09SLai Jiangshan max_huge_page_level); 4909c50d8ae3SPaolo Bonzini 4910c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4911c50d8ae3SPaolo Bonzini return; 4912c50d8ae3SPaolo Bonzini 4913a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4914c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4915c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4916c50d8ae3SPaolo Bonzini } 4917c50d8ae3SPaolo Bonzini } 4918c50d8ae3SPaolo Bonzini 4919c50d8ae3SPaolo Bonzini /* 4920c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4921c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4922c50d8ae3SPaolo Bonzini */ 4923c50d8ae3SPaolo Bonzini static void 4924e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4925c50d8ae3SPaolo Bonzini { 4926c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 492784ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 492884ea5c09SLai Jiangshan max_huge_page_level); 4929c50d8ae3SPaolo Bonzini } 4930c50d8ae3SPaolo Bonzini 4931c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4932c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4933c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4934c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4935c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4936c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4937c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4938c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4939c50d8ae3SPaolo Bonzini 4940c50d8ae3SPaolo Bonzini 4941c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4942c50d8ae3SPaolo Bonzini { 4943c50d8ae3SPaolo Bonzini unsigned byte; 4944c50d8ae3SPaolo Bonzini 4945c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4946c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4947c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4948c50d8ae3SPaolo Bonzini 4949c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4950c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4951c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 495290599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4953c50d8ae3SPaolo Bonzini 4954c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4955c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4956c50d8ae3SPaolo Bonzini 4957c50d8ae3SPaolo Bonzini /* 4958c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 4959c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 4960c50d8ae3SPaolo Bonzini */ 4961c50d8ae3SPaolo Bonzini 4962c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 4963c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 4964c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 4965c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 4966c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 4967c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 4968c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 4969c50d8ae3SPaolo Bonzini u8 smepf = 0; 4970c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 4971c50d8ae3SPaolo Bonzini u8 smapf = 0; 4972c50d8ae3SPaolo Bonzini 4973c50d8ae3SPaolo Bonzini if (!ept) { 4974c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 4975c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 4976c50d8ae3SPaolo Bonzini 4977c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 497890599c28SSean Christopherson if (!efer_nx) 4979c50d8ae3SPaolo Bonzini ff = 0; 4980c50d8ae3SPaolo Bonzini 4981c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 4982c50d8ae3SPaolo Bonzini if (!cr0_wp) 4983c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 4984c50d8ae3SPaolo Bonzini 4985c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 4986c50d8ae3SPaolo Bonzini if (cr4_smep) 4987c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 4988c50d8ae3SPaolo Bonzini 4989c50d8ae3SPaolo Bonzini /* 4990c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 4991c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 4992c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 4993c50d8ae3SPaolo Bonzini * conditions are true: 4994c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 4995c50d8ae3SPaolo Bonzini * - A user page is accessed 4996c50d8ae3SPaolo Bonzini * - The access is not a fetch 49974f4aa80eSLai Jiangshan * - The access is supervisor mode 49984f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 4999c50d8ae3SPaolo Bonzini * 500094b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 500194b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 5002c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 5003c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 5004c50d8ae3SPaolo Bonzini */ 5005c50d8ae3SPaolo Bonzini if (cr4_smap) 5006c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 5007c50d8ae3SPaolo Bonzini } 5008c50d8ae3SPaolo Bonzini 5009c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 5010c50d8ae3SPaolo Bonzini } 5011c50d8ae3SPaolo Bonzini } 5012c50d8ae3SPaolo Bonzini 5013c50d8ae3SPaolo Bonzini /* 5014c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 5015c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 5016c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 5017c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 5018c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 5019c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 5020c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 5021c50d8ae3SPaolo Bonzini * 5022c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 5023c50d8ae3SPaolo Bonzini * page tables and the machine state: 5024c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 5025c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 5026c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 5027c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 5028c50d8ae3SPaolo Bonzini * 5029c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 5030c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 5031c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 5032c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 5033c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 5034c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 5035c50d8ae3SPaolo Bonzini * only will be masked away. 5036c50d8ae3SPaolo Bonzini */ 50372e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 5038c50d8ae3SPaolo Bonzini { 5039c50d8ae3SPaolo Bonzini unsigned bit; 5040c50d8ae3SPaolo Bonzini bool wp; 5041c50d8ae3SPaolo Bonzini 5042c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 5043a3ca5281SChenyi Qiang 5044a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 5045c50d8ae3SPaolo Bonzini return; 5046c50d8ae3SPaolo Bonzini 50472e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 5048c50d8ae3SPaolo Bonzini 5049c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 5050c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 5051c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 5052c50d8ae3SPaolo Bonzini 5053c50d8ae3SPaolo Bonzini pfec = bit << 1; 5054c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 5055c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 5056c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 5057c50d8ae3SPaolo Bonzini 5058c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 5059c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 5060c50d8ae3SPaolo Bonzini 5061c50d8ae3SPaolo Bonzini /* 5062c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 5063c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 5064c50d8ae3SPaolo Bonzini */ 5065c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 5066c50d8ae3SPaolo Bonzini /* 5067c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 5068c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 5069c50d8ae3SPaolo Bonzini */ 5070c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 5071c50d8ae3SPaolo Bonzini 5072c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 5073c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 5074c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 5075c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 5076c50d8ae3SPaolo Bonzini 5077c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 5078c50d8ae3SPaolo Bonzini } 5079c50d8ae3SPaolo Bonzini } 5080c50d8ae3SPaolo Bonzini 5081533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 5082533f9a4bSSean Christopherson struct kvm_mmu *mmu) 5083c50d8ae3SPaolo Bonzini { 5084533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 5085533f9a4bSSean Christopherson return; 5086c50d8ae3SPaolo Bonzini 5087c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 5088533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 5089533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 5090c50d8ae3SPaolo Bonzini } 5091c50d8ae3SPaolo Bonzini 5092fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 5093c50d8ae3SPaolo Bonzini { 5094c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 5095c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5096c3c6c9fcSLai Jiangshan context->sync_spte = paging64_sync_spte; 5097c50d8ae3SPaolo Bonzini } 5098c50d8ae3SPaolo Bonzini 509984a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 5100c50d8ae3SPaolo Bonzini { 5101c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 5102c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5103c3c6c9fcSLai Jiangshan context->sync_spte = paging32_sync_spte; 5104c50d8ae3SPaolo Bonzini } 5105c50d8ae3SPaolo Bonzini 5106f3d90f90SSean Christopherson static union kvm_cpu_role kvm_calc_cpu_role(struct kvm_vcpu *vcpu, 5107f3d90f90SSean Christopherson const struct kvm_mmu_role_regs *regs) 5108e5ed0fb0SPaolo Bonzini { 51097a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5110e5ed0fb0SPaolo Bonzini 5111e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 5112e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 5113e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 5114e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 5115e5ed0fb0SPaolo Bonzini 5116e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 5117e5ed0fb0SPaolo Bonzini role.base.direct = 1; 5118e5ed0fb0SPaolo Bonzini return role; 5119e5ed0fb0SPaolo Bonzini } 5120e5ed0fb0SPaolo Bonzini 5121e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 5122e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 5123e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 5124e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 5125e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 512660f3cb60SPaolo Bonzini 512760f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 512860f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 512960f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 513060f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 513160f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 513260f3cb60SPaolo Bonzini else 513360f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 5134e5ed0fb0SPaolo Bonzini 5135e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 5136e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 5137e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 5138e5ed0fb0SPaolo Bonzini 5139e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 5140e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 5141e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 5142e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 5143e5ed0fb0SPaolo Bonzini return role; 5144e5ed0fb0SPaolo Bonzini } 5145e5ed0fb0SPaolo Bonzini 5146cf9f4c0eSSean Christopherson void __kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu, 5147cf9f4c0eSSean Christopherson struct kvm_mmu *mmu) 5148cf9f4c0eSSean Christopherson { 5149cf9f4c0eSSean Christopherson const bool cr0_wp = kvm_is_cr0_bit_set(vcpu, X86_CR0_WP); 5150cf9f4c0eSSean Christopherson 5151cf9f4c0eSSean Christopherson BUILD_BUG_ON((KVM_MMU_CR0_ROLE_BITS & KVM_POSSIBLE_CR0_GUEST_BITS) != X86_CR0_WP); 5152cf9f4c0eSSean Christopherson BUILD_BUG_ON((KVM_MMU_CR4_ROLE_BITS & KVM_POSSIBLE_CR4_GUEST_BITS)); 5153cf9f4c0eSSean Christopherson 5154cf9f4c0eSSean Christopherson if (is_cr0_wp(mmu) == cr0_wp) 5155cf9f4c0eSSean Christopherson return; 5156cf9f4c0eSSean Christopherson 5157cf9f4c0eSSean Christopherson mmu->cpu_role.base.cr0_wp = cr0_wp; 5158cf9f4c0eSSean Christopherson reset_guest_paging_metadata(vcpu, mmu); 5159cf9f4c0eSSean Christopherson } 5160cf9f4c0eSSean Christopherson 5161d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 5162d468d94bSSean Christopherson { 5163746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5164746700d2SWei Huang if (tdp_root_level) 5165746700d2SWei Huang return tdp_root_level; 5166746700d2SWei Huang 5167d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 516883013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5169d468d94bSSean Christopherson return 4; 5170d468d94bSSean Christopherson 517183013059SSean Christopherson return max_tdp_level; 5172d468d94bSSean Christopherson } 5173d468d94bSSean Christopherson 51747a458f0eSPaolo Bonzini static union kvm_mmu_page_role 51758626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 51767a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5177c50d8ae3SPaolo Bonzini { 51787a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5179c50d8ae3SPaolo Bonzini 51807a458f0eSPaolo Bonzini role.access = ACC_ALL; 51817a458f0eSPaolo Bonzini role.cr0_wp = true; 51827a458f0eSPaolo Bonzini role.efer_nx = true; 51837a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 51847a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 518554275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 51867a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 51877a458f0eSPaolo Bonzini role.direct = true; 51887a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5189c50d8ae3SPaolo Bonzini 5190c50d8ae3SPaolo Bonzini return role; 5191c50d8ae3SPaolo Bonzini } 5192c50d8ae3SPaolo Bonzini 519339e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5194a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5195c50d8ae3SPaolo Bonzini { 51968c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 51977a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5198c50d8ae3SPaolo Bonzini 5199e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 52007a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5201c50d8ae3SPaolo Bonzini return; 5202c50d8ae3SPaolo Bonzini 5203e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 52047a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 52057a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5206c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 52072fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5208c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5209c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5210c50d8ae3SPaolo Bonzini 521136f26787SSean Christopherson if (!is_cr0_pg(context)) 5212c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 521336f26787SSean Christopherson else if (is_cr4_pae(context)) 5214c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5215f4bd6f73SSean Christopherson else 5216c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5217c50d8ae3SPaolo Bonzini 5218533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5219e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5220c50d8ae3SPaolo Bonzini } 5221c50d8ae3SPaolo Bonzini 52228c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 52237a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 52247a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5225c50d8ae3SPaolo Bonzini { 5226e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 52277a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 522818db1b17SSean Christopherson return; 5229c50d8ae3SPaolo Bonzini 5230e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 52317a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 523218db1b17SSean Christopherson 523336f26787SSean Christopherson if (!is_cr0_pg(context)) 523484a16226SSean Christopherson nonpaging_init_context(context); 523536f26787SSean Christopherson else if (is_cr4_pae(context)) 5236fe660f72SSean Christopherson paging64_init_context(context); 5237c50d8ae3SPaolo Bonzini else 523884a16226SSean Christopherson paging32_init_context(context); 5239c50d8ae3SPaolo Bonzini 5240533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5241c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5242c50d8ae3SPaolo Bonzini } 52430f04a2acSVitaly Kuznetsov 5244594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5245a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 52460f04a2acSVitaly Kuznetsov { 52478c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 524856b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 524956b321f9SPaolo Bonzini 525056b321f9SPaolo Bonzini root_role = cpu_role.base; 525156b321f9SPaolo Bonzini 525256b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 525356b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 525456b321f9SPaolo Bonzini 525556b321f9SPaolo Bonzini /* 525656b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 525756b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 525856b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 525956b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 526056b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 526156b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 526256b321f9SPaolo Bonzini * MMU contexts. 526356b321f9SPaolo Bonzini */ 526456b321f9SPaolo Bonzini root_role.efer_nx = true; 52650f04a2acSVitaly Kuznetsov 52667a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 52670f04a2acSVitaly Kuznetsov } 52680f04a2acSVitaly Kuznetsov 5269dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5270dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 52710f04a2acSVitaly Kuznetsov { 52728c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5273594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5274594e91a1SSean Christopherson .cr0 = cr0, 527528f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5276594e91a1SSean Christopherson .efer = efer, 5277594e91a1SSean Christopherson }; 52787a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 527956b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 528056b321f9SPaolo Bonzini 528156b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 528256b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 528356b321f9SPaolo Bonzini 528456b321f9SPaolo Bonzini root_role = cpu_role.base; 528556b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 528684e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 528784e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 528884e5ffd0SLai Jiangshan root_role.passthrough = 1; 52890f04a2acSVitaly Kuznetsov 52907a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5291d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 52920f04a2acSVitaly Kuznetsov } 52930f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5294c50d8ae3SPaolo Bonzini 52957a7ae829SPaolo Bonzini static union kvm_cpu_role 5296c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5297bb1fcc70SSean Christopherson bool execonly, u8 level) 5298c50d8ae3SPaolo Bonzini { 52997a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5300c50d8ae3SPaolo Bonzini 5301daed87b8SPaolo Bonzini /* 5302daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5303daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5304daed87b8SPaolo Bonzini */ 5305daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5306bb1fcc70SSean Christopherson role.base.level = level; 5307bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5308c50d8ae3SPaolo Bonzini role.base.direct = false; 5309c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5310c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5311c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5312c50d8ae3SPaolo Bonzini 5313cd6767c3SSean Christopherson role.ext.word = 0; 5314c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5315cd6767c3SSean Christopherson role.ext.valid = 1; 5316c50d8ae3SPaolo Bonzini 5317c50d8ae3SPaolo Bonzini return role; 5318c50d8ae3SPaolo Bonzini } 5319c50d8ae3SPaolo Bonzini 5320c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5321cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5322cc022ae1SLai Jiangshan gpa_t new_eptp) 5323c50d8ae3SPaolo Bonzini { 53248c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5325bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 53267a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5327c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5328bb1fcc70SSean Christopherson execonly, level); 5329c50d8ae3SPaolo Bonzini 5330e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5331e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5332e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 53337a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 533418db1b17SSean Christopherson 5335c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5336c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5337c3c6c9fcSLai Jiangshan context->sync_spte = ept_sync_spte; 5338347a0d0dSPaolo Bonzini 5339c596f147SSean Christopherson update_permission_bitmask(context, true); 534028f091bcSPaolo Bonzini context->pkru_mask = 0; 5341cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5342e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5343c50d8ae3SPaolo Bonzini } 53443cffc89dSPaolo Bonzini 5345d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 53463cffc89dSPaolo Bonzini } 5347c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5348c50d8ae3SPaolo Bonzini 534939e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5350a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5351c50d8ae3SPaolo Bonzini { 53528c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5353c50d8ae3SPaolo Bonzini 5354a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5355929d1cfaSPaolo Bonzini 53562fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5357c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5358c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5359c50d8ae3SPaolo Bonzini } 5360c50d8ae3SPaolo Bonzini 536139e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5362a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5363c50d8ae3SPaolo Bonzini { 5364c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5365c50d8ae3SPaolo Bonzini 5366e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5367c50d8ae3SPaolo Bonzini return; 5368c50d8ae3SPaolo Bonzini 5369e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 53702fdcc1b3SPaolo Bonzini g_context->get_guest_pgd = get_guest_cr3; 5371c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5372c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5373c50d8ae3SPaolo Bonzini 5374c50d8ae3SPaolo Bonzini /* 53755efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 53765efac074SPaolo Bonzini * SPTEs. 53775efac074SPaolo Bonzini */ 53789fd4a4e3SLai Jiangshan g_context->sync_spte = NULL; 53795efac074SPaolo Bonzini 53805efac074SPaolo Bonzini /* 5381c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5382c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5383c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5384c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5385c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5386c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5387c50d8ae3SPaolo Bonzini */ 5388fa4b5588SSean Christopherson if (!is_paging(vcpu)) 53891f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5390fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 53911f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5392fa4b5588SSean Christopherson else if (is_pae(vcpu)) 53931f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5394fa4b5588SSean Christopherson else 53951f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5396fa4b5588SSean Christopherson 5397533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5398c50d8ae3SPaolo Bonzini } 5399c50d8ae3SPaolo Bonzini 5400c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5401c50d8ae3SPaolo Bonzini { 540239e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5403a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 540439e7e2bfSPaolo Bonzini 5405c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5406a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5407c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5408a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5409c50d8ae3SPaolo Bonzini else 5410a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5411c50d8ae3SPaolo Bonzini } 5412c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5413c50d8ae3SPaolo Bonzini 541449c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 541549c6f875SSean Christopherson { 541649c6f875SSean Christopherson /* 541749c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 541849c6f875SSean Christopherson * information is factored into reserved bit calculations. 5419feb627e8SVitaly Kuznetsov * 5420feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5421feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5422feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5423feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5424feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5425feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5426feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 542749c6f875SSean Christopherson */ 54287a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 54297a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 54307a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5431e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5432e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5433e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 543449c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 543563f5a190SSean Christopherson 543663f5a190SSean Christopherson /* 5437feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5438feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 543963f5a190SSean Christopherson */ 5440fb3146b4SSean Christopherson KVM_BUG_ON(kvm_vcpu_has_run(vcpu), vcpu->kvm); 544149c6f875SSean Christopherson } 544249c6f875SSean Christopherson 5443c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5444c50d8ae3SPaolo Bonzini { 5445c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5446c9060662SSean Christopherson kvm_init_mmu(vcpu); 5447c50d8ae3SPaolo Bonzini } 5448c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5449c50d8ae3SPaolo Bonzini 5450c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5451c50d8ae3SPaolo Bonzini { 5452c50d8ae3SPaolo Bonzini int r; 5453c50d8ae3SPaolo Bonzini 5454347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5455c50d8ae3SPaolo Bonzini if (r) 5456c50d8ae3SPaolo Bonzini goto out; 5457748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5458c50d8ae3SPaolo Bonzini if (r) 5459c50d8ae3SPaolo Bonzini goto out; 5460347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 54616e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 54626e6ec584SSean Christopherson else 54636e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5464c50d8ae3SPaolo Bonzini if (r) 5465c50d8ae3SPaolo Bonzini goto out; 5466a91f387bSSean Christopherson 5467a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5468a91f387bSSean Christopherson 5469727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5470db01416bSSean Christopherson 5471db01416bSSean Christopherson /* 5472db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5473db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5474db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5475db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5476db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5477db01416bSSean Christopherson */ 5478e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5479c50d8ae3SPaolo Bonzini out: 5480c50d8ae3SPaolo Bonzini return r; 5481c50d8ae3SPaolo Bonzini } 5482c50d8ae3SPaolo Bonzini 5483c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5484c50d8ae3SPaolo Bonzini { 54850c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 54860c1c92f1SPaolo Bonzini 54870c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 548820ba462dSSean Christopherson WARN_ON_ONCE(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 54890c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 549020ba462dSSean Christopherson WARN_ON_ONCE(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 54916d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5492c50d8ae3SPaolo Bonzini } 5493c50d8ae3SPaolo Bonzini 5494527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5495527d5cd7SSean Christopherson { 5496527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5497527d5cd7SSean Christopherson 5498527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5499527d5cd7SSean Christopherson return false; 5500527d5cd7SSean Christopherson 5501527d5cd7SSean Christopherson /* 5502527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5503527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5504527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5505527d5cd7SSean Christopherson * such false positives are relatively rare: 5506527d5cd7SSean Christopherson * 5507527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5508527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5509527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5510527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5511527d5cd7SSean Christopherson */ 5512527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5513527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5514527d5cd7SSean Christopherson } 5515527d5cd7SSean Christopherson 5516527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5517527d5cd7SSean Christopherson { 5518527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5519527d5cd7SSean Christopherson int i; 5520527d5cd7SSean Christopherson 5521527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5522527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5523527d5cd7SSean Christopherson 5524527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5525cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5526527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5527527d5cd7SSean Christopherson } 5528527d5cd7SSean Christopherson 5529527d5cd7SSean Christopherson if (roots_to_free) 5530527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5531527d5cd7SSean Christopherson } 5532527d5cd7SSean Christopherson 5533527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5534527d5cd7SSean Christopherson { 5535527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5536527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5537527d5cd7SSean Christopherson } 5538527d5cd7SSean Christopherson 5539c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5540c50d8ae3SPaolo Bonzini int *bytes) 5541c50d8ae3SPaolo Bonzini { 5542c50d8ae3SPaolo Bonzini u64 gentry = 0; 5543c50d8ae3SPaolo Bonzini int r; 5544c50d8ae3SPaolo Bonzini 5545c50d8ae3SPaolo Bonzini /* 5546c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5547c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5548c50d8ae3SPaolo Bonzini * when they have the same mode. 5549c50d8ae3SPaolo Bonzini */ 5550c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5551c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5552c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5553c50d8ae3SPaolo Bonzini *bytes = 8; 5554c50d8ae3SPaolo Bonzini } 5555c50d8ae3SPaolo Bonzini 5556c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5557c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5558c50d8ae3SPaolo Bonzini if (r) 5559c50d8ae3SPaolo Bonzini gentry = 0; 5560c50d8ae3SPaolo Bonzini } 5561c50d8ae3SPaolo Bonzini 5562c50d8ae3SPaolo Bonzini return gentry; 5563c50d8ae3SPaolo Bonzini } 5564c50d8ae3SPaolo Bonzini 5565c50d8ae3SPaolo Bonzini /* 5566c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5567c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5568c50d8ae3SPaolo Bonzini */ 5569c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5570c50d8ae3SPaolo Bonzini { 5571c50d8ae3SPaolo Bonzini /* 5572c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5573c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5574c50d8ae3SPaolo Bonzini */ 55753bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5576c50d8ae3SPaolo Bonzini return false; 5577c50d8ae3SPaolo Bonzini 5578c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5579c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5580c50d8ae3SPaolo Bonzini } 5581c50d8ae3SPaolo Bonzini 5582c50d8ae3SPaolo Bonzini /* 5583c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5584c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5585c50d8ae3SPaolo Bonzini */ 5586c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5587c50d8ae3SPaolo Bonzini int bytes) 5588c50d8ae3SPaolo Bonzini { 5589c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5590c50d8ae3SPaolo Bonzini 5591c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5592bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5593c50d8ae3SPaolo Bonzini 5594c50d8ae3SPaolo Bonzini /* 5595c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5596c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5597c50d8ae3SPaolo Bonzini */ 5598c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5599c50d8ae3SPaolo Bonzini return false; 5600c50d8ae3SPaolo Bonzini 5601c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5602c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5603c50d8ae3SPaolo Bonzini 5604c50d8ae3SPaolo Bonzini return misaligned; 5605c50d8ae3SPaolo Bonzini } 5606c50d8ae3SPaolo Bonzini 5607c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5608c50d8ae3SPaolo Bonzini { 5609c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5610c50d8ae3SPaolo Bonzini u64 *spte; 5611c50d8ae3SPaolo Bonzini int level; 5612c50d8ae3SPaolo Bonzini 5613c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5614c50d8ae3SPaolo Bonzini level = sp->role.level; 5615c50d8ae3SPaolo Bonzini *nspte = 1; 5616bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5617c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5618c50d8ae3SPaolo Bonzini /* 5619c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5620c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5621c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5622c50d8ae3SPaolo Bonzini */ 5623c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5624c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5625c50d8ae3SPaolo Bonzini page_offset <<= 1; 5626c50d8ae3SPaolo Bonzini *nspte = 2; 5627c50d8ae3SPaolo Bonzini } 5628c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5629c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5630c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5631c50d8ae3SPaolo Bonzini return NULL; 5632c50d8ae3SPaolo Bonzini } 5633c50d8ae3SPaolo Bonzini 5634c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5635c50d8ae3SPaolo Bonzini return spte; 5636c50d8ae3SPaolo Bonzini } 5637c50d8ae3SPaolo Bonzini 5638c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5639c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5640c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5641c50d8ae3SPaolo Bonzini { 5642c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5643c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5644c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5645c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5646c50d8ae3SPaolo Bonzini int npte; 564706152b2dSLai Jiangshan bool flush = false; 5648c50d8ae3SPaolo Bonzini 5649c50d8ae3SPaolo Bonzini /* 5650c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5651c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5652c50d8ae3SPaolo Bonzini */ 5653c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5654c50d8ae3SPaolo Bonzini return; 5655c50d8ae3SPaolo Bonzini 5656531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5657c50d8ae3SPaolo Bonzini 5658c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5659c50d8ae3SPaolo Bonzini 5660c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5661c50d8ae3SPaolo Bonzini 5662767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5663c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5664c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5665c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5666c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5667c50d8ae3SPaolo Bonzini continue; 5668c50d8ae3SPaolo Bonzini } 5669c50d8ae3SPaolo Bonzini 5670c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5671c50d8ae3SPaolo Bonzini if (!spte) 5672c50d8ae3SPaolo Bonzini continue; 5673c50d8ae3SPaolo Bonzini 5674c50d8ae3SPaolo Bonzini while (npte--) { 5675c50d8ae3SPaolo Bonzini entry = *spte; 56762de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5677c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5678c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 56791441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 568006152b2dSLai Jiangshan flush = true; 5681c50d8ae3SPaolo Bonzini ++spte; 5682c50d8ae3SPaolo Bonzini } 5683c50d8ae3SPaolo Bonzini } 568406152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5685531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5686c50d8ae3SPaolo Bonzini } 5687c50d8ae3SPaolo Bonzini 56881075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5689c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5690c50d8ae3SPaolo Bonzini { 569192daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5692347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5693c50d8ae3SPaolo Bonzini 5694d09f7112SSean Christopherson /* 5695d09f7112SSean Christopherson * IMPLICIT_ACCESS is a KVM-defined flag used to correctly perform SMAP 5696d09f7112SSean Christopherson * checks when emulating instructions that triggers implicit access. 5697d09f7112SSean Christopherson * WARN if hardware generates a fault with an error code that collides 5698d09f7112SSean Christopherson * with the KVM-defined value. Clear the flag and continue on, i.e. 5699d09f7112SSean Christopherson * don't terminate the VM, as KVM can't possibly be relying on a flag 5700d09f7112SSean Christopherson * that KVM doesn't know about. 5701d09f7112SSean Christopherson */ 5702d09f7112SSean Christopherson if (WARN_ON_ONCE(error_code & PFERR_IMPLICIT_ACCESS)) 5703d09f7112SSean Christopherson error_code &= ~PFERR_IMPLICIT_ACCESS; 5704d09f7112SSean Christopherson 570520ba462dSSean Christopherson if (WARN_ON_ONCE(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5706ddce6208SSean Christopherson return RET_PF_RETRY; 5707ddce6208SSean Christopherson 5708c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5709c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5710736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5711c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5712c50d8ae3SPaolo Bonzini goto emulate; 5713c50d8ae3SPaolo Bonzini } 5714c50d8ae3SPaolo Bonzini 5715c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 57167a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 5717258d985fSSean Christopherson lower_32_bits(error_code), false, 5718258d985fSSean Christopherson &emulation_type); 571919025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 57207b367bc9SSean Christopherson return -EIO; 5721c50d8ae3SPaolo Bonzini } 5722c50d8ae3SPaolo Bonzini 5723c50d8ae3SPaolo Bonzini if (r < 0) 5724c50d8ae3SPaolo Bonzini return r; 572583a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 572683a2ba4cSSean Christopherson return 1; 5727c50d8ae3SPaolo Bonzini 5728c50d8ae3SPaolo Bonzini /* 5729c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5730c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5731c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5732c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5733c50d8ae3SPaolo Bonzini * and resume the guest. 5734c50d8ae3SPaolo Bonzini */ 5735347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5736c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5737736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5738c50d8ae3SPaolo Bonzini return 1; 5739c50d8ae3SPaolo Bonzini } 5740c50d8ae3SPaolo Bonzini 5741c50d8ae3SPaolo Bonzini /* 5742c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5743c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5744c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5745c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5746c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5747c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5748c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5749c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5750c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5751c50d8ae3SPaolo Bonzini */ 5752736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 575392daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5754c50d8ae3SPaolo Bonzini emulate: 5755736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5756c50d8ae3SPaolo Bonzini insn_len); 5757c50d8ae3SPaolo Bonzini } 5758c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5759c50d8ae3SPaolo Bonzini 57609fd4a4e3SLai Jiangshan static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 57619fd4a4e3SLai Jiangshan u64 addr, hpa_t root_hpa) 57629fd4a4e3SLai Jiangshan { 57639fd4a4e3SLai Jiangshan struct kvm_shadow_walk_iterator iterator; 57649fd4a4e3SLai Jiangshan 57659fd4a4e3SLai Jiangshan vcpu_clear_mmio_info(vcpu, addr); 57669fd4a4e3SLai Jiangshan 5767762b33ebSLike Xu /* 5768762b33ebSLike Xu * Walking and synchronizing SPTEs both assume they are operating in 5769762b33ebSLike Xu * the context of the current MMU, and would need to be reworked if 5770762b33ebSLike Xu * this is ever used to sync the guest_mmu, e.g. to emulate INVEPT. 5771762b33ebSLike Xu */ 5772762b33ebSLike Xu if (WARN_ON_ONCE(mmu != vcpu->arch.mmu)) 5773762b33ebSLike Xu return; 5774762b33ebSLike Xu 57759fd4a4e3SLai Jiangshan if (!VALID_PAGE(root_hpa)) 57769fd4a4e3SLai Jiangshan return; 57779fd4a4e3SLai Jiangshan 57789fd4a4e3SLai Jiangshan write_lock(&vcpu->kvm->mmu_lock); 57799fd4a4e3SLai Jiangshan for_each_shadow_entry_using_root(vcpu, root_hpa, addr, iterator) { 57809fd4a4e3SLai Jiangshan struct kvm_mmu_page *sp = sptep_to_sp(iterator.sptep); 57819fd4a4e3SLai Jiangshan 57829fd4a4e3SLai Jiangshan if (sp->unsync) { 578319ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, iterator.index); 57849fd4a4e3SLai Jiangshan 57859fd4a4e3SLai Jiangshan if (ret < 0) 57869fd4a4e3SLai Jiangshan mmu_page_zap_pte(vcpu->kvm, sp, iterator.sptep, NULL); 57879fd4a4e3SLai Jiangshan if (ret) 57889fd4a4e3SLai Jiangshan kvm_flush_remote_tlbs_sptep(vcpu->kvm, iterator.sptep); 57899fd4a4e3SLai Jiangshan } 57909fd4a4e3SLai Jiangshan 57919fd4a4e3SLai Jiangshan if (!sp->unsync_children) 57929fd4a4e3SLai Jiangshan break; 57939fd4a4e3SLai Jiangshan } 57949fd4a4e3SLai Jiangshan write_unlock(&vcpu->kvm->mmu_lock); 57959fd4a4e3SLai Jiangshan } 57969fd4a4e3SLai Jiangshan 5797753b43c9SLai Jiangshan void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 5798cd42853eSLai Jiangshan u64 addr, unsigned long roots) 5799c50d8ae3SPaolo Bonzini { 5800c50d8ae3SPaolo Bonzini int i; 5801c50d8ae3SPaolo Bonzini 5802cd42853eSLai Jiangshan WARN_ON_ONCE(roots & ~KVM_MMU_ROOTS_ALL); 5803cd42853eSLai Jiangshan 58045efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 58055efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 58065efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5807753b43c9SLai Jiangshan if (is_noncanonical_address(addr, vcpu)) 5808c50d8ae3SPaolo Bonzini return; 5809c50d8ae3SPaolo Bonzini 5810753b43c9SLai Jiangshan static_call(kvm_x86_flush_tlb_gva)(vcpu, addr); 58115efac074SPaolo Bonzini } 58125efac074SPaolo Bonzini 58139fd4a4e3SLai Jiangshan if (!mmu->sync_spte) 58145efac074SPaolo Bonzini return; 58155efac074SPaolo Bonzini 5816cd42853eSLai Jiangshan if (roots & KVM_MMU_ROOT_CURRENT) 58179fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->root.hpa); 5818c50d8ae3SPaolo Bonzini 5819cd42853eSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5820ed335278SLai Jiangshan if (roots & KVM_MMU_ROOT_PREVIOUS(i)) 58219fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->prev_roots[i].hpa); 58225efac074SPaolo Bonzini } 58235efac074SPaolo Bonzini } 58242c86c444SLai Jiangshan EXPORT_SYMBOL_GPL(kvm_mmu_invalidate_addr); 5825c50d8ae3SPaolo Bonzini 58265efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 58275efac074SPaolo Bonzini { 5828cd42853eSLai Jiangshan /* 5829cd42853eSLai Jiangshan * INVLPG is required to invalidate any global mappings for the VA, 5830cd42853eSLai Jiangshan * irrespective of PCID. Blindly sync all roots as it would take 5831cd42853eSLai Jiangshan * roughly the same amount of work/time to determine whether any of the 5832cd42853eSLai Jiangshan * previous roots have a global mapping. 5833cd42853eSLai Jiangshan * 5834cd42853eSLai Jiangshan * Mappings not reachable via the current or previous cached roots will 5835cd42853eSLai Jiangshan * be synced when switching to that new cr3, so nothing needs to be 5836cd42853eSLai Jiangshan * done here for them. 5837cd42853eSLai Jiangshan */ 5838cd42853eSLai Jiangshan kvm_mmu_invalidate_addr(vcpu, vcpu->arch.walk_mmu, gva, KVM_MMU_ROOTS_ALL); 5839c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5840c50d8ae3SPaolo Bonzini } 5841c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5842c50d8ae3SPaolo Bonzini 58435efac074SPaolo Bonzini 5844c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5845c50d8ae3SPaolo Bonzini { 5846c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 58479ebc3f51SLai Jiangshan unsigned long roots = 0; 5848c50d8ae3SPaolo Bonzini uint i; 5849c50d8ae3SPaolo Bonzini 58509ebc3f51SLai Jiangshan if (pcid == kvm_get_active_pcid(vcpu)) 58519ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_CURRENT; 5852c50d8ae3SPaolo Bonzini 5853c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5854c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 58559ebc3f51SLai Jiangshan pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) 58569ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_PREVIOUS(i); 5857c50d8ae3SPaolo Bonzini } 5858c50d8ae3SPaolo Bonzini 58599ebc3f51SLai Jiangshan if (roots) 58609ebc3f51SLai Jiangshan kvm_mmu_invalidate_addr(vcpu, mmu, gva, roots); 5861c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5862c50d8ae3SPaolo Bonzini 5863c50d8ae3SPaolo Bonzini /* 5864c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5865c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5866c50d8ae3SPaolo Bonzini * for them. 5867c50d8ae3SPaolo Bonzini */ 5868c50d8ae3SPaolo Bonzini } 5869c50d8ae3SPaolo Bonzini 5870746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5871746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5872c50d8ae3SPaolo Bonzini { 5873bde77235SSean Christopherson tdp_enabled = enable_tdp; 5874746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 587583013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5876703c335dSSean Christopherson 58771f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 58781f98f2bdSDavid Matlack tdp_mmu_enabled = tdp_mmu_allowed && tdp_enabled; 58791f98f2bdSDavid Matlack #endif 5880703c335dSSean Christopherson /* 58811d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5882703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5883703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5884703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5885703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5886703c335dSSean Christopherson */ 5887703c335dSSean Christopherson if (tdp_enabled) 58881d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5889703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 58901d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5891703c335dSSean Christopherson else 58921d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5893c50d8ae3SPaolo Bonzini } 5894bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5895c50d8ae3SPaolo Bonzini 5896c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5897727ae377SSean Christopherson typedef bool (*slot_rmaps_handler) (struct kvm *kvm, 5898269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5899269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5900c50d8ae3SPaolo Bonzini 5901727ae377SSean Christopherson static __always_inline bool __walk_slot_rmaps(struct kvm *kvm, 5902727ae377SSean Christopherson const struct kvm_memory_slot *slot, 5903727ae377SSean Christopherson slot_rmaps_handler fn, 5904727ae377SSean Christopherson int start_level, int end_level, 5905727ae377SSean Christopherson gfn_t start_gfn, gfn_t end_gfn, 5906727ae377SSean Christopherson bool flush_on_yield, bool flush) 5907c50d8ae3SPaolo Bonzini { 5908c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5909c50d8ae3SPaolo Bonzini 5910eddd9e83SSean Christopherson lockdep_assert_held_write(&kvm->mmu_lock); 5911eddd9e83SSean Christopherson 5912727ae377SSean Christopherson for_each_slot_rmap_range(slot, start_level, end_level, start_gfn, 5913c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5914c50d8ae3SPaolo Bonzini if (iterator.rmap) 5915727ae377SSean Christopherson flush |= fn(kvm, iterator.rmap, slot); 5916c50d8ae3SPaolo Bonzini 5917531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5918302695a5SSean Christopherson if (flush && flush_on_yield) { 59198c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, start_gfn, 5920c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5921c50d8ae3SPaolo Bonzini flush = false; 5922c50d8ae3SPaolo Bonzini } 5923531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5924c50d8ae3SPaolo Bonzini } 5925c50d8ae3SPaolo Bonzini } 5926c50d8ae3SPaolo Bonzini 5927c50d8ae3SPaolo Bonzini return flush; 5928c50d8ae3SPaolo Bonzini } 5929c50d8ae3SPaolo Bonzini 5930727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps(struct kvm *kvm, 5931727ae377SSean Christopherson const struct kvm_memory_slot *slot, 5932727ae377SSean Christopherson slot_rmaps_handler fn, 5933727ae377SSean Christopherson int start_level, int end_level, 5934302695a5SSean Christopherson bool flush_on_yield) 5935c50d8ae3SPaolo Bonzini { 5936727ae377SSean Christopherson return __walk_slot_rmaps(kvm, slot, fn, start_level, end_level, 5937727ae377SSean Christopherson slot->base_gfn, slot->base_gfn + slot->npages - 1, 59381a61b7dbSSean Christopherson flush_on_yield, false); 5939c50d8ae3SPaolo Bonzini } 5940c50d8ae3SPaolo Bonzini 5941727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps_4k(struct kvm *kvm, 5942727ae377SSean Christopherson const struct kvm_memory_slot *slot, 5943727ae377SSean Christopherson slot_rmaps_handler fn, 5944727ae377SSean Christopherson bool flush_on_yield) 5945c50d8ae3SPaolo Bonzini { 5946727ae377SSean Christopherson return walk_slot_rmaps(kvm, slot, fn, PG_LEVEL_4K, PG_LEVEL_4K, flush_on_yield); 5947c50d8ae3SPaolo Bonzini } 5948c50d8ae3SPaolo Bonzini 5949c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5950c50d8ae3SPaolo Bonzini { 59514a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 59524a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5953c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 595403ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5955cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5956c50d8ae3SPaolo Bonzini } 5957c50d8ae3SPaolo Bonzini 595804d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5959c50d8ae3SPaolo Bonzini { 5960c50d8ae3SPaolo Bonzini struct page *page; 5961c50d8ae3SPaolo Bonzini int i; 5962c50d8ae3SPaolo Bonzini 5963b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5964b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 596504d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 596604d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 596704d28e37SSean Christopherson 596827f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 596927f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 597027f4fca2SLai Jiangshan return 0; 597127f4fca2SLai Jiangshan 5972c50d8ae3SPaolo Bonzini /* 5973c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5974c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5975c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5976c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 597704d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 597804d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 597904d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 598004d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 598184432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5982c50d8ae3SPaolo Bonzini */ 5983d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5984c50d8ae3SPaolo Bonzini return 0; 5985c50d8ae3SPaolo Bonzini 5986c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 5987c50d8ae3SPaolo Bonzini if (!page) 5988c50d8ae3SPaolo Bonzini return -ENOMEM; 5989c50d8ae3SPaolo Bonzini 5990c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 59914a98623dSSean Christopherson 59924a98623dSSean Christopherson /* 59934a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 59944a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 59954a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 59964a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 59974a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 59984a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 59994a98623dSSean Christopherson */ 60004a98623dSSean Christopherson if (!tdp_enabled) 60014a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 60024a98623dSSean Christopherson else 6003e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 60044a98623dSSean Christopherson 6005c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 6006c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 6007c50d8ae3SPaolo Bonzini 6008c50d8ae3SPaolo Bonzini return 0; 6009c50d8ae3SPaolo Bonzini } 6010c50d8ae3SPaolo Bonzini 6011c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 6012c50d8ae3SPaolo Bonzini { 6013c50d8ae3SPaolo Bonzini int ret; 6014c50d8ae3SPaolo Bonzini 60155962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 60165f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 60175f6078f9SSean Christopherson 60185962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 60195f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 60205962bfb7SSean Christopherson 602196880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 602296880883SSean Christopherson 6023c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 6024c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 6025c50d8ae3SPaolo Bonzini 602604d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 6027c50d8ae3SPaolo Bonzini if (ret) 6028c50d8ae3SPaolo Bonzini return ret; 6029c50d8ae3SPaolo Bonzini 603004d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 6031c50d8ae3SPaolo Bonzini if (ret) 6032c50d8ae3SPaolo Bonzini goto fail_allocate_root; 6033c50d8ae3SPaolo Bonzini 6034c50d8ae3SPaolo Bonzini return ret; 6035c50d8ae3SPaolo Bonzini fail_allocate_root: 6036c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6037c50d8ae3SPaolo Bonzini return ret; 6038c50d8ae3SPaolo Bonzini } 6039c50d8ae3SPaolo Bonzini 6040c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 6041c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 6042c50d8ae3SPaolo Bonzini { 6043c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6044c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 6045b28cb0cdSSean Christopherson bool unstable; 6046c50d8ae3SPaolo Bonzini 6047c50d8ae3SPaolo Bonzini restart: 6048c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 6049c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 6050c50d8ae3SPaolo Bonzini /* 6051c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 6052c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 6053c50d8ae3SPaolo Bonzini */ 6054c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 6055c50d8ae3SPaolo Bonzini break; 6056c50d8ae3SPaolo Bonzini 6057c50d8ae3SPaolo Bonzini /* 6058f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 6059f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 6060f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 6061c50d8ae3SPaolo Bonzini */ 606220ba462dSSean Christopherson if (WARN_ON_ONCE(sp->role.invalid)) 6063c50d8ae3SPaolo Bonzini continue; 6064c50d8ae3SPaolo Bonzini 6065c50d8ae3SPaolo Bonzini /* 6066c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 6067c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 6068c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 6069c50d8ae3SPaolo Bonzini * be in active use by the guest. 6070c50d8ae3SPaolo Bonzini */ 6071c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 6072531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 6073c50d8ae3SPaolo Bonzini batch = 0; 6074c50d8ae3SPaolo Bonzini goto restart; 6075c50d8ae3SPaolo Bonzini } 6076c50d8ae3SPaolo Bonzini 6077b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 6078b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 6079c50d8ae3SPaolo Bonzini batch += nr_zapped; 6080b28cb0cdSSean Christopherson 6081b28cb0cdSSean Christopherson if (unstable) 6082c50d8ae3SPaolo Bonzini goto restart; 6083c50d8ae3SPaolo Bonzini } 6084c50d8ae3SPaolo Bonzini 6085c50d8ae3SPaolo Bonzini /* 60867ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 60877ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 60887ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 60897ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 60907ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 60917ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 60927ae5840eSSean Christopherson * running with an obsolete MMU. 6093c50d8ae3SPaolo Bonzini */ 6094c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 6095c50d8ae3SPaolo Bonzini } 6096c50d8ae3SPaolo Bonzini 6097c50d8ae3SPaolo Bonzini /* 6098c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 6099c50d8ae3SPaolo Bonzini * to zap obsolete pages. 6100c50d8ae3SPaolo Bonzini * 6101c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 6102c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 6103c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 6104c50d8ae3SPaolo Bonzini * after calling the function. 6105c50d8ae3SPaolo Bonzini */ 6106c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 6107c50d8ae3SPaolo Bonzini { 6108c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 6109c50d8ae3SPaolo Bonzini 6110531810caSBen Gardon write_lock(&kvm->mmu_lock); 6111c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 6112c50d8ae3SPaolo Bonzini 6113c50d8ae3SPaolo Bonzini /* 6114c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 6115c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 6116c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 6117c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 6118c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 6119c50d8ae3SPaolo Bonzini */ 6120c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 6121c50d8ae3SPaolo Bonzini 61222f6f66ccSSean Christopherson /* 61232f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 61242f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 61252f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 61262f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 6127b7cccd39SBen Gardon */ 61281f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6129b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 6130b7cccd39SBen Gardon 6131c50d8ae3SPaolo Bonzini /* 6132c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 6133c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 6134c50d8ae3SPaolo Bonzini * mmu_valid_gen. 6135c50d8ae3SPaolo Bonzini * 6136c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 6137c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 6138c50d8ae3SPaolo Bonzini */ 6139527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 6140c50d8ae3SPaolo Bonzini 6141c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 6142faaf05b0SBen Gardon 6143531810caSBen Gardon write_unlock(&kvm->mmu_lock); 61444c6654bdSBen Gardon 6145f28e9c7fSSean Christopherson /* 6146f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 6147f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 6148f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 6149f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 6150f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 6151f28e9c7fSSean Christopherson * lead to use-after-free. 6152f28e9c7fSSean Christopherson */ 61531f98f2bdSDavid Matlack if (tdp_mmu_enabled) 61544c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 6155c50d8ae3SPaolo Bonzini } 6156c50d8ae3SPaolo Bonzini 6157c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 6158c50d8ae3SPaolo Bonzini { 6159c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 6160c50d8ae3SPaolo Bonzini } 6161c50d8ae3SPaolo Bonzini 6162c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 6163c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 6164c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 6165c50d8ae3SPaolo Bonzini { 6166c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6167c50d8ae3SPaolo Bonzini } 6168c50d8ae3SPaolo Bonzini 6169a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 6170c50d8ae3SPaolo Bonzini { 6171c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6172a1a39128SPaolo Bonzini int r; 6173c50d8ae3SPaolo Bonzini 6174a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 6175a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 617655c510e2SSean Christopherson INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages); 6177ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 6178ce25681dSSean Christopherson 617909732d2bSDavid Matlack if (tdp_mmu_enabled) { 6180a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 6181a1a39128SPaolo Bonzini if (r < 0) 6182a1a39128SPaolo Bonzini return r; 618309732d2bSDavid Matlack } 6184fe5db27dSBen Gardon 6185c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 6186c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 6187c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 6188ada51a9dSDavid Matlack 6189ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 6190ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 6191ada51a9dSDavid Matlack 6192ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 6193ada51a9dSDavid Matlack 6194ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 6195ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 6196ada51a9dSDavid Matlack 6197a1a39128SPaolo Bonzini return 0; 6198c50d8ae3SPaolo Bonzini } 6199c50d8ae3SPaolo Bonzini 6200ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 6201ada51a9dSDavid Matlack { 6202ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 6203ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6204ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6205ada51a9dSDavid Matlack } 6206ada51a9dSDavid Matlack 6207c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6208c50d8ae3SPaolo Bonzini { 6209c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6210c50d8ae3SPaolo Bonzini 6211c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 6212fe5db27dSBen Gardon 621309732d2bSDavid Matlack if (tdp_mmu_enabled) 6214fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6215ada51a9dSDavid Matlack 6216ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6217c50d8ae3SPaolo Bonzini } 6218c50d8ae3SPaolo Bonzini 62192833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 622021fa3246SSean Christopherson { 622121fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 622221fa3246SSean Christopherson struct kvm_memslots *slots; 6223f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 622421fa3246SSean Christopherson bool flush = false; 622521fa3246SSean Christopherson gfn_t start, end; 6226f4209439SMaciej S. Szmigiero int i; 622721fa3246SSean Christopherson 622821fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 622921fa3246SSean Christopherson return flush; 623021fa3246SSean Christopherson 623121fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 623221fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6233f4209439SMaciej S. Szmigiero 6234f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6235f4209439SMaciej S. Szmigiero memslot = iter.slot; 623621fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 623721fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6238f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 623921fa3246SSean Christopherson continue; 624021fa3246SSean Christopherson 6241727ae377SSean Christopherson flush = __walk_slot_rmaps(kvm, memslot, __kvm_zap_rmap, 624221fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 624321fa3246SSean Christopherson start, end - 1, true, flush); 624421fa3246SSean Christopherson } 624521fa3246SSean Christopherson } 624621fa3246SSean Christopherson 624721fa3246SSean Christopherson return flush; 624821fa3246SSean Christopherson } 624921fa3246SSean Christopherson 625088f58535SMaxim Levitsky /* 625188f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 625288f58535SMaxim Levitsky * (not including it) 625388f58535SMaxim Levitsky */ 6254c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6255c50d8ae3SPaolo Bonzini { 625621fa3246SSean Christopherson bool flush; 6257c50d8ae3SPaolo Bonzini int i; 6258c50d8ae3SPaolo Bonzini 6259f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6260f4209439SMaciej S. Szmigiero return; 6261f4209439SMaciej S. Szmigiero 6262531810caSBen Gardon write_lock(&kvm->mmu_lock); 62635a324c24SSean Christopherson 62646d3085e4SSean Christopherson kvm_mmu_invalidate_begin(kvm, 0, -1ul); 6265edb298c6SMaxim Levitsky 62662833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 62676103bc07SBen Gardon 62681f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 62696103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 6270f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 6271f47e5bbbSSean Christopherson gfn_end, true, flush); 62726103bc07SBen Gardon } 62735a324c24SSean Christopherson 62745a324c24SSean Christopherson if (flush) 62758c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, gfn_start, gfn_end - gfn_start); 62765a324c24SSean Christopherson 62776d3085e4SSean Christopherson kvm_mmu_invalidate_end(kvm, 0, -1ul); 6278edb298c6SMaxim Levitsky 62795a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6280c50d8ae3SPaolo Bonzini } 6281c50d8ae3SPaolo Bonzini 6282c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 62830a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6284269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6285c50d8ae3SPaolo Bonzini { 62861346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6287c50d8ae3SPaolo Bonzini } 6288c50d8ae3SPaolo Bonzini 6289c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6290269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 62913c9bd400SJay Zhou int start_level) 6292c50d8ae3SPaolo Bonzini { 6293e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6294531810caSBen Gardon write_lock(&kvm->mmu_lock); 6295727ae377SSean Christopherson walk_slot_rmaps(kvm, memslot, slot_rmap_write_protect, 6296b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6297531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6298e2209710SBen Gardon } 6299c50d8ae3SPaolo Bonzini 63001f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 630124ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6302b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 630324ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 630424ae4cfaSBen Gardon } 6305c50d8ae3SPaolo Bonzini } 6306c50d8ae3SPaolo Bonzini 6307ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6308ada51a9dSDavid Matlack { 6309ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6310ada51a9dSDavid Matlack } 6311ada51a9dSDavid Matlack 6312ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6313ada51a9dSDavid Matlack { 6314ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6315ada51a9dSDavid Matlack return true; 6316ada51a9dSDavid Matlack 6317ada51a9dSDavid Matlack /* 6318ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6319ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6320ada51a9dSDavid Matlack * is possible but not worth the complexity. 6321ada51a9dSDavid Matlack */ 6322ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6323ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6324ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6325ada51a9dSDavid Matlack } 6326ada51a9dSDavid Matlack 6327ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6328ada51a9dSDavid Matlack { 6329b9b71f43SSean Christopherson /* 6330b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6331dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6332b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6333dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6334dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6335dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6336dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6337dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6338dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6339dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6340b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6341b9b71f43SSean Christopherson */ 6342b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6343b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6344ada51a9dSDavid Matlack int r; 6345ada51a9dSDavid Matlack 6346ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6347ada51a9dSDavid Matlack 6348b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6349ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6350ada51a9dSDavid Matlack if (r) 6351ada51a9dSDavid Matlack return r; 6352ada51a9dSDavid Matlack 6353ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6354ada51a9dSDavid Matlack if (r) 6355ada51a9dSDavid Matlack return r; 6356ada51a9dSDavid Matlack 6357ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6358ada51a9dSDavid Matlack } 6359ada51a9dSDavid Matlack 6360ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6361ada51a9dSDavid Matlack { 6362ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6363ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6364ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6365ada51a9dSDavid Matlack unsigned int access; 6366ada51a9dSDavid Matlack gfn_t gfn; 6367ada51a9dSDavid Matlack 636879e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 636979e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6370ada51a9dSDavid Matlack 6371ada51a9dSDavid Matlack /* 6372ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6373ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6374ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6375ada51a9dSDavid Matlack * mapped with smaller pages. 6376ada51a9dSDavid Matlack */ 6377ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6378ada51a9dSDavid Matlack 6379ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6380ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6381ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6382ada51a9dSDavid Matlack 6383ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6384ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6385ada51a9dSDavid Matlack } 6386ada51a9dSDavid Matlack 6387ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6388ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6389ada51a9dSDavid Matlack u64 *huge_sptep) 6390ada51a9dSDavid Matlack 6391ada51a9dSDavid Matlack { 6392ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6393ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6394ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 639503787394SPaolo Bonzini bool flush = false; 6396ada51a9dSDavid Matlack u64 *sptep, spte; 6397ada51a9dSDavid Matlack gfn_t gfn; 6398ada51a9dSDavid Matlack int index; 6399ada51a9dSDavid Matlack 6400ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6401ada51a9dSDavid Matlack 6402ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6403ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6404ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6405ada51a9dSDavid Matlack 6406ada51a9dSDavid Matlack /* 6407ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6408ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6409ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6410ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6411ada51a9dSDavid Matlack * modify them. 6412ada51a9dSDavid Matlack * 641303787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 641403787394SPaolo Bonzini * that lower level page table may only be partially populated. 641503787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 641603787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 641703787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 641803787394SPaolo Bonzini * fail to detect the need to flush. 6419ada51a9dSDavid Matlack */ 642003787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 642103787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6422ada51a9dSDavid Matlack continue; 642303787394SPaolo Bonzini } 6424ada51a9dSDavid Matlack 6425ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6426ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6427ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6428ada51a9dSDavid Matlack } 6429ada51a9dSDavid Matlack 643003787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6431ada51a9dSDavid Matlack } 6432ada51a9dSDavid Matlack 6433ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6434ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6435ada51a9dSDavid Matlack u64 *huge_sptep) 6436ada51a9dSDavid Matlack { 6437ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6438ada51a9dSDavid Matlack int level, r = 0; 6439ada51a9dSDavid Matlack gfn_t gfn; 6440ada51a9dSDavid Matlack u64 spte; 6441ada51a9dSDavid Matlack 6442ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 644379e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6444ada51a9dSDavid Matlack level = huge_sp->role.level; 6445ada51a9dSDavid Matlack spte = *huge_sptep; 6446ada51a9dSDavid Matlack 6447ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6448ada51a9dSDavid Matlack r = -ENOSPC; 6449ada51a9dSDavid Matlack goto out; 6450ada51a9dSDavid Matlack } 6451ada51a9dSDavid Matlack 6452ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6453ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6454ada51a9dSDavid Matlack cond_resched(); 6455ada51a9dSDavid Matlack /* 6456ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6457ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6458ada51a9dSDavid Matlack * dropped. 6459ada51a9dSDavid Matlack */ 6460ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6461ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6462ada51a9dSDavid Matlack goto out; 6463ada51a9dSDavid Matlack } 6464ada51a9dSDavid Matlack 6465ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6466ada51a9dSDavid Matlack 6467ada51a9dSDavid Matlack out: 6468ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6469ada51a9dSDavid Matlack return r; 6470ada51a9dSDavid Matlack } 6471ada51a9dSDavid Matlack 6472ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6473ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6474ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6475ada51a9dSDavid Matlack { 6476ada51a9dSDavid Matlack struct rmap_iterator iter; 6477ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6478ada51a9dSDavid Matlack u64 *huge_sptep; 6479ada51a9dSDavid Matlack int r; 6480ada51a9dSDavid Matlack 6481ada51a9dSDavid Matlack restart: 6482ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6483ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6484ada51a9dSDavid Matlack 6485ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6486ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6487ada51a9dSDavid Matlack continue; 6488ada51a9dSDavid Matlack 6489ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6490ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6491ada51a9dSDavid Matlack continue; 6492ada51a9dSDavid Matlack 6493ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6494ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6495ada51a9dSDavid Matlack continue; 6496ada51a9dSDavid Matlack 6497ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6498ada51a9dSDavid Matlack if (sp->role.invalid) 6499ada51a9dSDavid Matlack continue; 6500ada51a9dSDavid Matlack 6501ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6502ada51a9dSDavid Matlack 6503ada51a9dSDavid Matlack /* 6504ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6505ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6506ada51a9dSDavid Matlack * back into a consistent state. 6507ada51a9dSDavid Matlack */ 6508ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6509ada51a9dSDavid Matlack goto restart; 6510ada51a9dSDavid Matlack 6511ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6512ada51a9dSDavid Matlack break; 6513ada51a9dSDavid Matlack } 6514ada51a9dSDavid Matlack 6515ada51a9dSDavid Matlack return false; 6516ada51a9dSDavid Matlack } 6517ada51a9dSDavid Matlack 6518ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6519ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6520ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6521ada51a9dSDavid Matlack int target_level) 6522ada51a9dSDavid Matlack { 6523ada51a9dSDavid Matlack int level; 6524ada51a9dSDavid Matlack 6525ada51a9dSDavid Matlack /* 6526ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6527ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6528ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6529ada51a9dSDavid Matlack * already at the target level. 6530ada51a9dSDavid Matlack */ 6531727ae377SSean Christopherson for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) 6532727ae377SSean Christopherson __walk_slot_rmaps(kvm, slot, shadow_mmu_try_split_huge_pages, 6533ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6534ada51a9dSDavid Matlack } 6535ada51a9dSDavid Matlack 6536cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6537cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6538cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6539cb00a70bSDavid Matlack u64 start, u64 end, 6540cb00a70bSDavid Matlack int target_level) 6541cb00a70bSDavid Matlack { 65421f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6543ada51a9dSDavid Matlack return; 6544ada51a9dSDavid Matlack 6545ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6546ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6547ada51a9dSDavid Matlack 6548ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6549cb00a70bSDavid Matlack 6550cb00a70bSDavid Matlack /* 6551cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6552cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6553cb00a70bSDavid Matlack */ 6554cb00a70bSDavid Matlack } 6555cb00a70bSDavid Matlack 6556a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6557a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6558a3fe5dbdSDavid Matlack int target_level) 6559a3fe5dbdSDavid Matlack { 6560a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6561a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6562a3fe5dbdSDavid Matlack 65631f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6564ada51a9dSDavid Matlack return; 6565ada51a9dSDavid Matlack 6566ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6567ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6568ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6569ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6570ada51a9dSDavid Matlack } 6571ada51a9dSDavid Matlack 6572a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6573cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6574a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6575a3fe5dbdSDavid Matlack 6576a3fe5dbdSDavid Matlack /* 6577a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6578a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6579a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6580a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6581a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6582a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6583a3fe5dbdSDavid Matlack * SPTEs. 6584a3fe5dbdSDavid Matlack */ 6585a3fe5dbdSDavid Matlack } 6586a3fe5dbdSDavid Matlack 6587c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 65880a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6589269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6590c50d8ae3SPaolo Bonzini { 6591c50d8ae3SPaolo Bonzini u64 *sptep; 6592c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6593c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6594c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6595c50d8ae3SPaolo Bonzini 6596c50d8ae3SPaolo Bonzini restart: 6597c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 659857354682SSean Christopherson sp = sptep_to_sp(sptep); 6599c50d8ae3SPaolo Bonzini 6600c50d8ae3SPaolo Bonzini /* 6601c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6602c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6603c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6604c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6605c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6606c50d8ae3SPaolo Bonzini */ 66075d49f08cSSean Christopherson if (sp->role.direct && 66089eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6609a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 66109202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6611c50d8ae3SPaolo Bonzini 66128a1300ffSSean Christopherson if (kvm_available_flush_remote_tlbs_range()) 66131b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 6614c50d8ae3SPaolo Bonzini else 6615c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6616c50d8ae3SPaolo Bonzini 6617c50d8ae3SPaolo Bonzini goto restart; 6618c50d8ae3SPaolo Bonzini } 6619c50d8ae3SPaolo Bonzini } 6620c50d8ae3SPaolo Bonzini 6621c50d8ae3SPaolo Bonzini return need_tlb_flush; 6622c50d8ae3SPaolo Bonzini } 6623c50d8ae3SPaolo Bonzini 662420d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 662520d49186SDavid Matlack const struct kvm_memory_slot *slot) 662620d49186SDavid Matlack { 662720d49186SDavid Matlack /* 662820d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 662920d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 663020d49186SDavid Matlack */ 6631727ae377SSean Christopherson if (walk_slot_rmaps(kvm, slot, kvm_mmu_zap_collapsible_spte, 663220d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 6633619b5072SDavid Matlack kvm_flush_remote_tlbs_memslot(kvm, slot); 663420d49186SDavid Matlack } 663520d49186SDavid Matlack 6636c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6637269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6638c50d8ae3SPaolo Bonzini { 6639e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6640531810caSBen Gardon write_lock(&kvm->mmu_lock); 664120d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6642531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6643e2209710SBen Gardon } 66442db6f772SBen Gardon 66451f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 66462db6f772SBen Gardon read_lock(&kvm->mmu_lock); 66474b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 66482db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 66492db6f772SBen Gardon } 6650c50d8ae3SPaolo Bonzini } 6651c50d8ae3SPaolo Bonzini 6652c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6653269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6654c50d8ae3SPaolo Bonzini { 6655e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6656531810caSBen Gardon write_lock(&kvm->mmu_lock); 6657610265eaSDavid Matlack /* 6658610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6659610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6660610265eaSDavid Matlack */ 6661727ae377SSean Christopherson walk_slot_rmaps_4k(kvm, memslot, __rmap_clear_dirty, false); 6662531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6663e2209710SBen Gardon } 6664c50d8ae3SPaolo Bonzini 66651f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 666624ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6667b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 666824ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 666924ae4cfaSBen Gardon } 667024ae4cfaSBen Gardon 6671c50d8ae3SPaolo Bonzini /* 6672b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6673b64d740eSJunaid Shahid * 6674c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6675c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6676c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6677c50d8ae3SPaolo Bonzini * dirty_bitmap. 6678c50d8ae3SPaolo Bonzini */ 6679c50d8ae3SPaolo Bonzini } 6680c50d8ae3SPaolo Bonzini 6681*db0d70e6SSean Christopherson static void kvm_mmu_zap_all(struct kvm *kvm) 6682c50d8ae3SPaolo Bonzini { 6683c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6684c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6685c50d8ae3SPaolo Bonzini int ign; 6686c50d8ae3SPaolo Bonzini 6687531810caSBen Gardon write_lock(&kvm->mmu_lock); 6688c50d8ae3SPaolo Bonzini restart: 6689c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 669020ba462dSSean Christopherson if (WARN_ON_ONCE(sp->role.invalid)) 6691c50d8ae3SPaolo Bonzini continue; 6692c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6693c50d8ae3SPaolo Bonzini goto restart; 6694531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6695c50d8ae3SPaolo Bonzini goto restart; 6696c50d8ae3SPaolo Bonzini } 6697c50d8ae3SPaolo Bonzini 6698c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6699faaf05b0SBen Gardon 67001f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6701faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6702faaf05b0SBen Gardon 6703531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6704c50d8ae3SPaolo Bonzini } 6705c50d8ae3SPaolo Bonzini 6706*db0d70e6SSean Christopherson void kvm_arch_flush_shadow_all(struct kvm *kvm) 6707*db0d70e6SSean Christopherson { 6708*db0d70e6SSean Christopherson kvm_mmu_zap_all(kvm); 6709*db0d70e6SSean Christopherson } 6710*db0d70e6SSean Christopherson 6711*db0d70e6SSean Christopherson void kvm_arch_flush_shadow_memslot(struct kvm *kvm, 6712*db0d70e6SSean Christopherson struct kvm_memory_slot *slot) 6713*db0d70e6SSean Christopherson { 6714*db0d70e6SSean Christopherson kvm_page_track_flush_slot(kvm, slot); 6715*db0d70e6SSean Christopherson } 6716*db0d70e6SSean Christopherson 6717c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6718c50d8ae3SPaolo Bonzini { 671920ba462dSSean Christopherson WARN_ON_ONCE(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6720c50d8ae3SPaolo Bonzini 6721c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6722c50d8ae3SPaolo Bonzini 6723c50d8ae3SPaolo Bonzini /* 6724c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6725c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6726c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6727c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6728c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6729c50d8ae3SPaolo Bonzini */ 6730c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6731c50d8ae3SPaolo Bonzini 6732c50d8ae3SPaolo Bonzini /* 6733c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6734c50d8ae3SPaolo Bonzini * zap all shadow pages. 6735c50d8ae3SPaolo Bonzini */ 6736c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 67378d20bd63SSean Christopherson kvm_debug_ratelimited("zapping shadow pages for mmio generation wraparound\n"); 6738c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6739c50d8ae3SPaolo Bonzini } 6740c50d8ae3SPaolo Bonzini } 6741c50d8ae3SPaolo Bonzini 6742f3d90f90SSean Christopherson static unsigned long mmu_shrink_scan(struct shrinker *shrink, 6743f3d90f90SSean Christopherson struct shrink_control *sc) 6744c50d8ae3SPaolo Bonzini { 6745c50d8ae3SPaolo Bonzini struct kvm *kvm; 6746c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6747c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6748c50d8ae3SPaolo Bonzini 6749c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6750c50d8ae3SPaolo Bonzini 6751c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6752c50d8ae3SPaolo Bonzini int idx; 6753c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6754c50d8ae3SPaolo Bonzini 6755c50d8ae3SPaolo Bonzini /* 6756c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6757c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6758c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6759c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6760c50d8ae3SPaolo Bonzini */ 6761c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6762c50d8ae3SPaolo Bonzini break; 6763c50d8ae3SPaolo Bonzini /* 6764c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6765c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6766c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6767c50d8ae3SPaolo Bonzini * anyway. 6768c50d8ae3SPaolo Bonzini */ 6769c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6770c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6771c50d8ae3SPaolo Bonzini continue; 6772c50d8ae3SPaolo Bonzini 6773c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6774531810caSBen Gardon write_lock(&kvm->mmu_lock); 6775c50d8ae3SPaolo Bonzini 6776c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6777c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6778c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6779c50d8ae3SPaolo Bonzini goto unlock; 6780c50d8ae3SPaolo Bonzini } 6781c50d8ae3SPaolo Bonzini 6782ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6783c50d8ae3SPaolo Bonzini 6784c50d8ae3SPaolo Bonzini unlock: 6785531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6786c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6787c50d8ae3SPaolo Bonzini 6788c50d8ae3SPaolo Bonzini /* 6789c50d8ae3SPaolo Bonzini * unfair on small ones 6790c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6791c50d8ae3SPaolo Bonzini * sadness comes quickly 6792c50d8ae3SPaolo Bonzini */ 6793c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6794c50d8ae3SPaolo Bonzini break; 6795c50d8ae3SPaolo Bonzini } 6796c50d8ae3SPaolo Bonzini 6797c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6798c50d8ae3SPaolo Bonzini return freed; 6799c50d8ae3SPaolo Bonzini } 6800c50d8ae3SPaolo Bonzini 6801f3d90f90SSean Christopherson static unsigned long mmu_shrink_count(struct shrinker *shrink, 6802f3d90f90SSean Christopherson struct shrink_control *sc) 6803c50d8ae3SPaolo Bonzini { 6804c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6805c50d8ae3SPaolo Bonzini } 6806c50d8ae3SPaolo Bonzini 6807c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6808c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6809c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6810c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6811c50d8ae3SPaolo Bonzini }; 6812c50d8ae3SPaolo Bonzini 6813c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6814c50d8ae3SPaolo Bonzini { 6815c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6816c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6817c50d8ae3SPaolo Bonzini } 6818c50d8ae3SPaolo Bonzini 68190b210fafSSean Christopherson static int get_nx_huge_pages(char *buffer, const struct kernel_param *kp) 68200b210fafSSean Christopherson { 68210b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 68221d6664faSLike Xu return sysfs_emit(buffer, "never\n"); 68230b210fafSSean Christopherson 68240b210fafSSean Christopherson return param_get_bool(buffer, kp); 68250b210fafSSean Christopherson } 68260b210fafSSean Christopherson 6827c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6828c50d8ae3SPaolo Bonzini { 6829c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6830c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6831c50d8ae3SPaolo Bonzini } 6832c50d8ae3SPaolo Bonzini 6833c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6834c50d8ae3SPaolo Bonzini { 6835c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6836c50d8ae3SPaolo Bonzini } 6837c50d8ae3SPaolo Bonzini 6838c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6839c50d8ae3SPaolo Bonzini { 6840c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6841c50d8ae3SPaolo Bonzini bool new_val; 6842c50d8ae3SPaolo Bonzini 68430b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 68440b210fafSSean Christopherson return -EPERM; 68450b210fafSSean Christopherson 6846c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 68470b210fafSSean Christopherson if (sysfs_streq(val, "off")) { 6848c50d8ae3SPaolo Bonzini new_val = 0; 68490b210fafSSean Christopherson } else if (sysfs_streq(val, "force")) { 6850c50d8ae3SPaolo Bonzini new_val = 1; 68510b210fafSSean Christopherson } else if (sysfs_streq(val, "auto")) { 6852c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 68530b210fafSSean Christopherson } else if (sysfs_streq(val, "never")) { 68540b210fafSSean Christopherson new_val = 0; 68550b210fafSSean Christopherson 68560b210fafSSean Christopherson mutex_lock(&kvm_lock); 68570b210fafSSean Christopherson if (!list_empty(&vm_list)) { 68580b210fafSSean Christopherson mutex_unlock(&kvm_lock); 68590b210fafSSean Christopherson return -EBUSY; 68600b210fafSSean Christopherson } 68610b210fafSSean Christopherson nx_hugepage_mitigation_hard_disabled = true; 68620b210fafSSean Christopherson mutex_unlock(&kvm_lock); 68630b210fafSSean Christopherson } else if (kstrtobool(val, &new_val) < 0) { 6864c50d8ae3SPaolo Bonzini return -EINVAL; 68650b210fafSSean Christopherson } 6866c50d8ae3SPaolo Bonzini 6867c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6868c50d8ae3SPaolo Bonzini 6869c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6870c50d8ae3SPaolo Bonzini struct kvm *kvm; 6871c50d8ae3SPaolo Bonzini 6872c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6873c50d8ae3SPaolo Bonzini 6874c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6875c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6876c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6877c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6878c50d8ae3SPaolo Bonzini 687955c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 6880c50d8ae3SPaolo Bonzini } 6881c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6882c50d8ae3SPaolo Bonzini } 6883c50d8ae3SPaolo Bonzini 6884c50d8ae3SPaolo Bonzini return 0; 6885c50d8ae3SPaolo Bonzini } 6886c50d8ae3SPaolo Bonzini 68871d0e8480SSean Christopherson /* 68881d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 68891d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 6890c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 6891c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 68921d0e8480SSean Christopherson */ 6893982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 6894c50d8ae3SPaolo Bonzini { 6895c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6896c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 6897c3e0c8c2SSean Christopherson 68981f98f2bdSDavid Matlack /* 68991f98f2bdSDavid Matlack * Snapshot userspace's desire to enable the TDP MMU. Whether or not the 69001f98f2bdSDavid Matlack * TDP MMU is actually enabled is determined in kvm_configure_mmu() 69011f98f2bdSDavid Matlack * when the vendor module is loaded. 69021f98f2bdSDavid Matlack */ 69031f98f2bdSDavid Matlack tdp_mmu_allowed = tdp_mmu_enabled; 69041f98f2bdSDavid Matlack 6905c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 69061d0e8480SSean Christopherson } 69071d0e8480SSean Christopherson 69081d0e8480SSean Christopherson /* 69091d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 69101d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 69111d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 69121d0e8480SSean Christopherson */ 69131d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 69141d0e8480SSean Christopherson { 69151d0e8480SSean Christopherson int ret = -ENOMEM; 6916c50d8ae3SPaolo Bonzini 6917c50d8ae3SPaolo Bonzini /* 6918c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6919c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6920c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6921c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6922c50d8ae3SPaolo Bonzini */ 6923c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6924c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 69257a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6926c50d8ae3SPaolo Bonzini 6927c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6928c50d8ae3SPaolo Bonzini 6929c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6930c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6931c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6932c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6933c50d8ae3SPaolo Bonzini goto out; 6934c50d8ae3SPaolo Bonzini 6935c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6936c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6937c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6938c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6939c50d8ae3SPaolo Bonzini goto out; 6940c50d8ae3SPaolo Bonzini 6941c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6942c50d8ae3SPaolo Bonzini goto out; 6943c50d8ae3SPaolo Bonzini 6944e33c267aSRoman Gushchin ret = register_shrinker(&mmu_shrinker, "x86-mmu"); 6945c50d8ae3SPaolo Bonzini if (ret) 6946d7c9bfb9SMiaohe Lin goto out_shrinker; 6947c50d8ae3SPaolo Bonzini 6948c50d8ae3SPaolo Bonzini return 0; 6949c50d8ae3SPaolo Bonzini 6950d7c9bfb9SMiaohe Lin out_shrinker: 6951d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 6952c50d8ae3SPaolo Bonzini out: 6953c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6954c50d8ae3SPaolo Bonzini return ret; 6955c50d8ae3SPaolo Bonzini } 6956c50d8ae3SPaolo Bonzini 6957c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6958c50d8ae3SPaolo Bonzini { 6959c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6960c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6961c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6962c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6963c50d8ae3SPaolo Bonzini } 6964c50d8ae3SPaolo Bonzini 69651d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6966c50d8ae3SPaolo Bonzini { 6967c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6968c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6969c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6970c50d8ae3SPaolo Bonzini } 6971c50d8ae3SPaolo Bonzini 6972f47491d7SSean Christopherson /* 6973f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6974f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6975f47491d7SSean Christopherson */ 6976f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6977f47491d7SSean Christopherson { 6978f47491d7SSean Christopherson /* 6979f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6980f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6981f47491d7SSean Christopherson */ 6982f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6983f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6984f47491d7SSean Christopherson 6985f47491d7SSean Christopherson if (!enabled || !ratio) 6986f47491d7SSean Christopherson return false; 6987f47491d7SSean Christopherson 6988f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6989f47491d7SSean Christopherson if (!*period) { 6990f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6991f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6992f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6993f47491d7SSean Christopherson } 6994f47491d7SSean Christopherson return true; 6995f47491d7SSean Christopherson } 6996f47491d7SSean Christopherson 69974dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6998c50d8ae3SPaolo Bonzini { 69994dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 70004dfe4f40SJunaid Shahid uint old_period, new_period; 7001c50d8ae3SPaolo Bonzini int err; 7002c50d8ae3SPaolo Bonzini 70030b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 70040b210fafSSean Christopherson return -EPERM; 70050b210fafSSean Christopherson 7006f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 70074dfe4f40SJunaid Shahid 7008c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 7009c50d8ae3SPaolo Bonzini if (err) 7010c50d8ae3SPaolo Bonzini return err; 7011c50d8ae3SPaolo Bonzini 7012f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 70134dfe4f40SJunaid Shahid 7014f47491d7SSean Christopherson if (is_recovery_enabled && 70154dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 7016c50d8ae3SPaolo Bonzini struct kvm *kvm; 7017c50d8ae3SPaolo Bonzini 7018c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 7019c50d8ae3SPaolo Bonzini 7020c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 702155c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 7022c50d8ae3SPaolo Bonzini 7023c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 7024c50d8ae3SPaolo Bonzini } 7025c50d8ae3SPaolo Bonzini 7026c50d8ae3SPaolo Bonzini return err; 7027c50d8ae3SPaolo Bonzini } 7028c50d8ae3SPaolo Bonzini 702955c510e2SSean Christopherson static void kvm_recover_nx_huge_pages(struct kvm *kvm) 7030c50d8ae3SPaolo Bonzini { 7031ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 7032eb298605SDavid Matlack struct kvm_memory_slot *slot; 7033c50d8ae3SPaolo Bonzini int rcu_idx; 7034c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 7035c50d8ae3SPaolo Bonzini unsigned int ratio; 7036c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 7037048f4980SSean Christopherson bool flush = false; 7038c50d8ae3SPaolo Bonzini ulong to_zap; 7039c50d8ae3SPaolo Bonzini 7040c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 7041531810caSBen Gardon write_lock(&kvm->mmu_lock); 7042c50d8ae3SPaolo Bonzini 7043bb95dfb9SSean Christopherson /* 7044bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 7045bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 7046bb95dfb9SSean Christopherson * callback. 7047bb95dfb9SSean Christopherson */ 7048bb95dfb9SSean Christopherson rcu_read_lock(); 7049bb95dfb9SSean Christopherson 7050c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 7051ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 70527d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 705355c510e2SSean Christopherson if (list_empty(&kvm->arch.possible_nx_huge_pages)) 70547d919c7aSSean Christopherson break; 70557d919c7aSSean Christopherson 7056c50d8ae3SPaolo Bonzini /* 7057c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 705855c510e2SSean Christopherson * because the number of shadow pages that be replaced with an 705955c510e2SSean Christopherson * NX huge page is expected to be relatively small compared to 706055c510e2SSean Christopherson * the total number of shadow pages. And because the TDP MMU 706155c510e2SSean Christopherson * doesn't use active_mmu_pages. 7062c50d8ae3SPaolo Bonzini */ 706355c510e2SSean Christopherson sp = list_first_entry(&kvm->arch.possible_nx_huge_pages, 7064c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 706555c510e2SSean Christopherson possible_nx_huge_page_link); 706655c510e2SSean Christopherson WARN_ON_ONCE(!sp->nx_huge_page_disallowed); 7067eb298605SDavid Matlack WARN_ON_ONCE(!sp->role.direct); 7068eb298605SDavid Matlack 7069eb298605SDavid Matlack /* 7070eb298605SDavid Matlack * Unaccount and do not attempt to recover any NX Huge Pages 7071eb298605SDavid Matlack * that are being dirty tracked, as they would just be faulted 7072eb298605SDavid Matlack * back in as 4KiB pages. The NX Huge Pages in this slot will be 7073eb298605SDavid Matlack * recovered, along with all the other huge pages in the slot, 7074eb298605SDavid Matlack * when dirty logging is disabled. 70756c7b2202SPaolo Bonzini * 70766c7b2202SPaolo Bonzini * Since gfn_to_memslot() is relatively expensive, it helps to 70776c7b2202SPaolo Bonzini * skip it if it the test cannot possibly return true. On the 70786c7b2202SPaolo Bonzini * other hand, if any memslot has logging enabled, chances are 70796c7b2202SPaolo Bonzini * good that all of them do, in which case unaccount_nx_huge_page() 70806c7b2202SPaolo Bonzini * is much cheaper than zapping the page. 70816c7b2202SPaolo Bonzini * 70826c7b2202SPaolo Bonzini * If a memslot update is in progress, reading an incorrect value 70836c7b2202SPaolo Bonzini * of kvm->nr_memslots_dirty_logging is not a problem: if it is 70846c7b2202SPaolo Bonzini * becoming zero, gfn_to_memslot() will be done unnecessarily; if 70856c7b2202SPaolo Bonzini * it is becoming nonzero, the page will be zapped unnecessarily. 70866c7b2202SPaolo Bonzini * Either way, this only affects efficiency in racy situations, 70876c7b2202SPaolo Bonzini * and not correctness. 7088eb298605SDavid Matlack */ 70896c7b2202SPaolo Bonzini slot = NULL; 70906c7b2202SPaolo Bonzini if (atomic_read(&kvm->nr_memslots_dirty_logging)) { 7091817fa998SSean Christopherson struct kvm_memslots *slots; 7092817fa998SSean Christopherson 7093817fa998SSean Christopherson slots = kvm_memslots_for_spte_role(kvm, sp->role); 7094817fa998SSean Christopherson slot = __gfn_to_memslot(slots, sp->gfn); 70956c7b2202SPaolo Bonzini WARN_ON_ONCE(!slot); 709629cf0f50SBen Gardon } 7097c50d8ae3SPaolo Bonzini 7098eb298605SDavid Matlack if (slot && kvm_slot_dirty_track_enabled(slot)) 7099eb298605SDavid Matlack unaccount_nx_huge_page(kvm, sp); 7100eb298605SDavid Matlack else if (is_tdp_mmu_page(sp)) 7101c50d8ae3SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 71023a056757SSean Christopherson else 7103c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 710455c510e2SSean Christopherson WARN_ON_ONCE(sp->nx_huge_page_disallowed); 7105c50d8ae3SPaolo Bonzini 7106531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 7107048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7108bb95dfb9SSean Christopherson rcu_read_unlock(); 7109bb95dfb9SSean Christopherson 7110531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 7111048f4980SSean Christopherson flush = false; 7112bb95dfb9SSean Christopherson 7113bb95dfb9SSean Christopherson rcu_read_lock(); 7114c50d8ae3SPaolo Bonzini } 7115c50d8ae3SPaolo Bonzini } 7116048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7117c50d8ae3SPaolo Bonzini 7118bb95dfb9SSean Christopherson rcu_read_unlock(); 7119bb95dfb9SSean Christopherson 7120531810caSBen Gardon write_unlock(&kvm->mmu_lock); 7121c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 7122c50d8ae3SPaolo Bonzini } 7123c50d8ae3SPaolo Bonzini 712455c510e2SSean Christopherson static long get_nx_huge_page_recovery_timeout(u64 start_time) 7125c50d8ae3SPaolo Bonzini { 7126f47491d7SSean Christopherson bool enabled; 7127f47491d7SSean Christopherson uint period; 71284dfe4f40SJunaid Shahid 7129f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 71304dfe4f40SJunaid Shahid 7131f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 7132c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 7133c50d8ae3SPaolo Bonzini } 7134c50d8ae3SPaolo Bonzini 713555c510e2SSean Christopherson static int kvm_nx_huge_page_recovery_worker(struct kvm *kvm, uintptr_t data) 7136c50d8ae3SPaolo Bonzini { 7137c50d8ae3SPaolo Bonzini u64 start_time; 7138c50d8ae3SPaolo Bonzini long remaining_time; 7139c50d8ae3SPaolo Bonzini 7140c50d8ae3SPaolo Bonzini while (true) { 7141c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 714255c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7143c50d8ae3SPaolo Bonzini 7144c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7145c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 7146c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 714755c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7148c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7149c50d8ae3SPaolo Bonzini } 7150c50d8ae3SPaolo Bonzini 7151c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 7152c50d8ae3SPaolo Bonzini 7153c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 7154c50d8ae3SPaolo Bonzini return 0; 7155c50d8ae3SPaolo Bonzini 715655c510e2SSean Christopherson kvm_recover_nx_huge_pages(kvm); 7157c50d8ae3SPaolo Bonzini } 7158c50d8ae3SPaolo Bonzini } 7159c50d8ae3SPaolo Bonzini 7160c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 7161c50d8ae3SPaolo Bonzini { 7162c50d8ae3SPaolo Bonzini int err; 7163c50d8ae3SPaolo Bonzini 71640b210fafSSean Christopherson if (nx_hugepage_mitigation_hard_disabled) 71650b210fafSSean Christopherson return 0; 71660b210fafSSean Christopherson 716755c510e2SSean Christopherson err = kvm_vm_create_worker_thread(kvm, kvm_nx_huge_page_recovery_worker, 0, 7168c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 716955c510e2SSean Christopherson &kvm->arch.nx_huge_page_recovery_thread); 7170c50d8ae3SPaolo Bonzini if (!err) 717155c510e2SSean Christopherson kthread_unpark(kvm->arch.nx_huge_page_recovery_thread); 7172c50d8ae3SPaolo Bonzini 7173c50d8ae3SPaolo Bonzini return err; 7174c50d8ae3SPaolo Bonzini } 7175c50d8ae3SPaolo Bonzini 7176c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 7177c50d8ae3SPaolo Bonzini { 717855c510e2SSean Christopherson if (kvm->arch.nx_huge_page_recovery_thread) 717955c510e2SSean Christopherson kthread_stop(kvm->arch.nx_huge_page_recovery_thread); 7180c50d8ae3SPaolo Bonzini } 7181