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 61a9d6496dSShaokun Zhang int __read_mostly nx_huge_pages = -1; 624dfe4f40SJunaid Shahid static uint __read_mostly nx_huge_pages_recovery_period_ms; 63c50d8ae3SPaolo Bonzini #ifdef CONFIG_PREEMPT_RT 64c50d8ae3SPaolo Bonzini /* Recovery can cause latency spikes, disable it for PREEMPT_RT. */ 65c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 0; 66c50d8ae3SPaolo Bonzini #else 67c50d8ae3SPaolo Bonzini static uint __read_mostly nx_huge_pages_recovery_ratio = 60; 68c50d8ae3SPaolo Bonzini #endif 69c50d8ae3SPaolo Bonzini 70c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp); 714dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp); 72c50d8ae3SPaolo Bonzini 73d5d6c18dSJoe Perches static const struct kernel_param_ops nx_huge_pages_ops = { 74c50d8ae3SPaolo Bonzini .set = set_nx_huge_pages, 75c50d8ae3SPaolo Bonzini .get = param_get_bool, 76c50d8ae3SPaolo Bonzini }; 77c50d8ae3SPaolo Bonzini 784dfe4f40SJunaid Shahid static const struct kernel_param_ops nx_huge_pages_recovery_param_ops = { 794dfe4f40SJunaid Shahid .set = set_nx_huge_pages_recovery_param, 80c50d8ae3SPaolo Bonzini .get = param_get_uint, 81c50d8ae3SPaolo Bonzini }; 82c50d8ae3SPaolo Bonzini 83c50d8ae3SPaolo Bonzini module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644); 84c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages, "bool"); 854dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_param_ops, 86c50d8ae3SPaolo Bonzini &nx_huge_pages_recovery_ratio, 0644); 87c50d8ae3SPaolo Bonzini __MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint"); 884dfe4f40SJunaid Shahid module_param_cb(nx_huge_pages_recovery_period_ms, &nx_huge_pages_recovery_param_ops, 894dfe4f40SJunaid Shahid &nx_huge_pages_recovery_period_ms, 0644); 904dfe4f40SJunaid Shahid __MODULE_PARM_TYPE(nx_huge_pages_recovery_period_ms, "uint"); 91c50d8ae3SPaolo Bonzini 9271fe7013SSean Christopherson static bool __read_mostly force_flush_and_sync_on_reuse; 9371fe7013SSean Christopherson module_param_named(flush_on_reuse, force_flush_and_sync_on_reuse, bool, 0644); 9471fe7013SSean Christopherson 95c50d8ae3SPaolo Bonzini /* 96c50d8ae3SPaolo Bonzini * When setting this variable to true it enables Two-Dimensional-Paging 97c50d8ae3SPaolo Bonzini * where the hardware walks 2 page tables: 98c50d8ae3SPaolo Bonzini * 1. the guest-virtual to guest-physical 99c50d8ae3SPaolo Bonzini * 2. while doing 1. it walks guest-physical to host-physical 100c50d8ae3SPaolo Bonzini * If the hardware supports that we don't need to do shadow paging. 101c50d8ae3SPaolo Bonzini */ 102c50d8ae3SPaolo Bonzini bool tdp_enabled = false; 103c50d8ae3SPaolo Bonzini 1047f604e92SDavid Matlack static bool __ro_after_init tdp_mmu_allowed; 1051f98f2bdSDavid Matlack 1061f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 1071f98f2bdSDavid Matlack bool __read_mostly tdp_mmu_enabled = true; 1081f98f2bdSDavid Matlack module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0444); 1091f98f2bdSDavid Matlack #endif 1101f98f2bdSDavid Matlack 1111d92d2e8SSean Christopherson static int max_huge_page_level __read_mostly; 112746700d2SWei Huang static int tdp_root_level __read_mostly; 11383013059SSean Christopherson static int max_tdp_level __read_mostly; 114703c335dSSean Christopherson 115c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1165a9624afSPaolo Bonzini bool dbg = 0; 117c50d8ae3SPaolo Bonzini module_param(dbg, bool, 0644); 118c50d8ae3SPaolo Bonzini #endif 119c50d8ae3SPaolo Bonzini 120c50d8ae3SPaolo Bonzini #define PTE_PREFETCH_NUM 8 121c50d8ae3SPaolo Bonzini 122c50d8ae3SPaolo Bonzini #include <trace/events/kvm.h> 123c50d8ae3SPaolo Bonzini 124dc1cff96SPeter Xu /* make pte_list_desc fit well in cache lines */ 12513236e25SPeter Xu #define PTE_LIST_EXT 14 126c50d8ae3SPaolo Bonzini 12713236e25SPeter Xu /* 128141705b7SLai Jiangshan * struct pte_list_desc is the core data structure used to implement a custom 129141705b7SLai Jiangshan * list for tracking a set of related SPTEs, e.g. all the SPTEs that map a 130141705b7SLai Jiangshan * given GFN when used in the context of rmaps. Using a custom list allows KVM 131141705b7SLai Jiangshan * to optimize for the common case where many GFNs will have at most a handful 132141705b7SLai Jiangshan * of SPTEs pointing at them, i.e. allows packing multiple SPTEs into a small 133141705b7SLai Jiangshan * memory footprint, which in turn improves runtime performance by exploiting 134141705b7SLai Jiangshan * cache locality. 135141705b7SLai Jiangshan * 136141705b7SLai Jiangshan * A list is comprised of one or more pte_list_desc objects (descriptors). 137141705b7SLai Jiangshan * Each individual descriptor stores up to PTE_LIST_EXT SPTEs. If a descriptor 138141705b7SLai Jiangshan * is full and a new SPTEs needs to be added, a new descriptor is allocated and 139141705b7SLai Jiangshan * becomes the head of the list. This means that by definitions, all tail 140141705b7SLai Jiangshan * descriptors are full. 141141705b7SLai Jiangshan * 142141705b7SLai Jiangshan * Note, the meta data fields are deliberately placed at the start of the 143141705b7SLai Jiangshan * structure to optimize the cacheline layout; accessing the descriptor will 144141705b7SLai Jiangshan * touch only a single cacheline so long as @spte_count<=6 (or if only the 145141705b7SLai Jiangshan * descriptors metadata is accessed). 14613236e25SPeter Xu */ 147c50d8ae3SPaolo Bonzini struct pte_list_desc { 148c50d8ae3SPaolo Bonzini struct pte_list_desc *more; 149141705b7SLai Jiangshan /* The number of PTEs stored in _this_ descriptor. */ 150141705b7SLai Jiangshan u32 spte_count; 151141705b7SLai Jiangshan /* The number of PTEs stored in all tails of this descriptor. */ 152141705b7SLai Jiangshan u32 tail_count; 15313236e25SPeter Xu u64 *sptes[PTE_LIST_EXT]; 154c50d8ae3SPaolo Bonzini }; 155c50d8ae3SPaolo Bonzini 156c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator { 157c50d8ae3SPaolo Bonzini u64 addr; 158c50d8ae3SPaolo Bonzini hpa_t shadow_addr; 159c50d8ae3SPaolo Bonzini u64 *sptep; 160c50d8ae3SPaolo Bonzini int level; 161c50d8ae3SPaolo Bonzini unsigned index; 162c50d8ae3SPaolo Bonzini }; 163c50d8ae3SPaolo Bonzini 164c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ 165c50d8ae3SPaolo Bonzini for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ 166c50d8ae3SPaolo Bonzini (_root), (_addr)); \ 167c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 168c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 169c50d8ae3SPaolo Bonzini 170c50d8ae3SPaolo Bonzini #define for_each_shadow_entry(_vcpu, _addr, _walker) \ 171c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 172c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)); \ 173c50d8ae3SPaolo Bonzini shadow_walk_next(&(_walker))) 174c50d8ae3SPaolo Bonzini 175c50d8ae3SPaolo Bonzini #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \ 176c50d8ae3SPaolo Bonzini for (shadow_walk_init(&(_walker), _vcpu, _addr); \ 177c50d8ae3SPaolo Bonzini shadow_walk_okay(&(_walker)) && \ 178c50d8ae3SPaolo Bonzini ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \ 179c50d8ae3SPaolo Bonzini __shadow_walk_next(&(_walker), spte)) 180c50d8ae3SPaolo Bonzini 181c50d8ae3SPaolo Bonzini static struct kmem_cache *pte_list_desc_cache; 18202c00b3aSBen Gardon struct kmem_cache *mmu_page_header_cache; 183c50d8ae3SPaolo Bonzini static struct percpu_counter kvm_total_used_mmu_pages; 184c50d8ae3SPaolo Bonzini 185c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 spte); 186c50d8ae3SPaolo Bonzini 187594e91a1SSean Christopherson struct kvm_mmu_role_regs { 188594e91a1SSean Christopherson const unsigned long cr0; 189594e91a1SSean Christopherson const unsigned long cr4; 190594e91a1SSean Christopherson const u64 efer; 191594e91a1SSean Christopherson }; 192594e91a1SSean Christopherson 193c50d8ae3SPaolo Bonzini #define CREATE_TRACE_POINTS 194c50d8ae3SPaolo Bonzini #include "mmutrace.h" 195c50d8ae3SPaolo Bonzini 196594e91a1SSean Christopherson /* 197594e91a1SSean Christopherson * Yes, lot's of underscores. They're a hint that you probably shouldn't be 1987a458f0eSPaolo Bonzini * reading from the role_regs. Once the root_role is constructed, it becomes 199594e91a1SSean Christopherson * the single source of truth for the MMU's state. 200594e91a1SSean Christopherson */ 201594e91a1SSean Christopherson #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \ 20282ffa13fSPaolo Bonzini static inline bool __maybe_unused \ 20382ffa13fSPaolo Bonzini ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \ 204594e91a1SSean Christopherson { \ 205594e91a1SSean Christopherson return !!(regs->reg & flag); \ 206594e91a1SSean Christopherson } 207594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, pg, X86_CR0_PG); 208594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr0, wp, X86_CR0_WP); 209594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pse, X86_CR4_PSE); 210594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pae, X86_CR4_PAE); 211594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smep, X86_CR4_SMEP); 212594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, smap, X86_CR4_SMAP); 213594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, pke, X86_CR4_PKE); 214594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(cr4, la57, X86_CR4_LA57); 215594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, nx, EFER_NX); 216594e91a1SSean Christopherson BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA); 217594e91a1SSean Christopherson 21860667724SSean Christopherson /* 21960667724SSean Christopherson * The MMU itself (with a valid role) is the single source of truth for the 22060667724SSean Christopherson * MMU. Do not use the regs used to build the MMU/role, nor the vCPU. The 22160667724SSean Christopherson * regs don't account for dependencies, e.g. clearing CR4 bits if CR0.PG=1, 22260667724SSean Christopherson * and the vCPU may be incorrect/irrelevant. 22360667724SSean Christopherson */ 22460667724SSean Christopherson #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name) \ 2254ac21457SPaolo Bonzini static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu) \ 22660667724SSean Christopherson { \ 227e5ed0fb0SPaolo Bonzini return !!(mmu->cpu_role. base_or_ext . reg##_##name); \ 22860667724SSean Christopherson } 22960667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp); 23060667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pse); 23160667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smep); 23260667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, smap); 23360667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, pke); 23460667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(ext, cr4, la57); 23560667724SSean Christopherson BUILD_MMU_ROLE_ACCESSOR(base, efer, nx); 23656b321f9SPaolo Bonzini BUILD_MMU_ROLE_ACCESSOR(ext, efer, lma); 23760667724SSean Christopherson 238faf72962SPaolo Bonzini static inline bool is_cr0_pg(struct kvm_mmu *mmu) 239faf72962SPaolo Bonzini { 240faf72962SPaolo Bonzini return mmu->cpu_role.base.level > 0; 241faf72962SPaolo Bonzini } 242faf72962SPaolo Bonzini 243faf72962SPaolo Bonzini static inline bool is_cr4_pae(struct kvm_mmu *mmu) 244faf72962SPaolo Bonzini { 245faf72962SPaolo Bonzini return !mmu->cpu_role.base.has_4_byte_gpte; 246faf72962SPaolo Bonzini } 247faf72962SPaolo Bonzini 248594e91a1SSean Christopherson static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu) 249594e91a1SSean Christopherson { 250594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 251594e91a1SSean Christopherson .cr0 = kvm_read_cr0_bits(vcpu, KVM_MMU_CR0_ROLE_BITS), 252594e91a1SSean Christopherson .cr4 = kvm_read_cr4_bits(vcpu, KVM_MMU_CR4_ROLE_BITS), 253594e91a1SSean Christopherson .efer = vcpu->arch.efer, 254594e91a1SSean Christopherson }; 255594e91a1SSean Christopherson 256594e91a1SSean Christopherson return regs; 257594e91a1SSean Christopherson } 258c50d8ae3SPaolo Bonzini 259*2fdcc1b3SPaolo Bonzini static unsigned long get_guest_cr3(struct kvm_vcpu *vcpu) 260*2fdcc1b3SPaolo Bonzini { 261*2fdcc1b3SPaolo Bonzini return kvm_read_cr3(vcpu); 262*2fdcc1b3SPaolo Bonzini } 263*2fdcc1b3SPaolo Bonzini 264*2fdcc1b3SPaolo Bonzini static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu, 265*2fdcc1b3SPaolo Bonzini struct kvm_mmu *mmu) 266*2fdcc1b3SPaolo Bonzini { 267*2fdcc1b3SPaolo Bonzini if (IS_ENABLED(CONFIG_RETPOLINE) && mmu->get_guest_pgd == get_guest_cr3) 268*2fdcc1b3SPaolo Bonzini return kvm_read_cr3(vcpu); 269*2fdcc1b3SPaolo Bonzini 270*2fdcc1b3SPaolo Bonzini return mmu->get_guest_pgd(vcpu); 271*2fdcc1b3SPaolo Bonzini } 272*2fdcc1b3SPaolo Bonzini 273c50d8ae3SPaolo Bonzini static inline bool kvm_available_flush_tlb_with_range(void) 274c50d8ae3SPaolo Bonzini { 275afaf0b2fSSean Christopherson return kvm_x86_ops.tlb_remote_flush_with_range; 276c50d8ae3SPaolo Bonzini } 277c50d8ae3SPaolo Bonzini 2789d4655daSDavid Matlack void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, 2799d4655daSDavid Matlack gfn_t nr_pages) 280c50d8ae3SPaolo Bonzini { 281c50d8ae3SPaolo Bonzini struct kvm_tlb_range range; 28228e4b459SDavid Matlack int ret = -EOPNOTSUPP; 283c50d8ae3SPaolo Bonzini 284c50d8ae3SPaolo Bonzini range.start_gfn = start_gfn; 2859d4655daSDavid Matlack range.pages = nr_pages; 286c50d8ae3SPaolo Bonzini 28728e4b459SDavid Matlack if (kvm_x86_ops.tlb_remote_flush_with_range) 28828e4b459SDavid Matlack ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, &range); 28928e4b459SDavid Matlack 29028e4b459SDavid Matlack if (ret) 29128e4b459SDavid Matlack kvm_flush_remote_tlbs(kvm); 292c50d8ae3SPaolo Bonzini } 293c50d8ae3SPaolo Bonzini 2941b2dc736SHou Wenlong static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index); 2951b2dc736SHou Wenlong 2961b2dc736SHou Wenlong /* Flush the range of guest memory mapped by the given SPTE. */ 2971b2dc736SHou Wenlong static void kvm_flush_remote_tlbs_sptep(struct kvm *kvm, u64 *sptep) 2981b2dc736SHou Wenlong { 2991b2dc736SHou Wenlong struct kvm_mmu_page *sp = sptep_to_sp(sptep); 3001b2dc736SHou Wenlong gfn_t gfn = kvm_mmu_page_get_gfn(sp, spte_index(sptep)); 3011b2dc736SHou Wenlong 3021b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 3031b2dc736SHou Wenlong } 3041b2dc736SHou Wenlong 3058f79b064SBen Gardon static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, 3068f79b064SBen Gardon unsigned int access) 3078f79b064SBen Gardon { 308c236d962SSean Christopherson u64 spte = make_mmio_spte(vcpu, gfn, access); 3098f79b064SBen Gardon 310c236d962SSean Christopherson trace_mark_mmio_spte(sptep, gfn, spte); 311c236d962SSean Christopherson mmu_spte_set(sptep, spte); 312c50d8ae3SPaolo Bonzini } 313c50d8ae3SPaolo Bonzini 314c50d8ae3SPaolo Bonzini static gfn_t get_mmio_spte_gfn(u64 spte) 315c50d8ae3SPaolo Bonzini { 316c50d8ae3SPaolo Bonzini u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask; 317c50d8ae3SPaolo Bonzini 3188a967d65SPaolo Bonzini gpa |= (spte >> SHADOW_NONPRESENT_OR_RSVD_MASK_LEN) 319c50d8ae3SPaolo Bonzini & shadow_nonpresent_or_rsvd_mask; 320c50d8ae3SPaolo Bonzini 321c50d8ae3SPaolo Bonzini return gpa >> PAGE_SHIFT; 322c50d8ae3SPaolo Bonzini } 323c50d8ae3SPaolo Bonzini 324c50d8ae3SPaolo Bonzini static unsigned get_mmio_spte_access(u64 spte) 325c50d8ae3SPaolo Bonzini { 326c50d8ae3SPaolo Bonzini return spte & shadow_mmio_access_mask; 327c50d8ae3SPaolo Bonzini } 328c50d8ae3SPaolo Bonzini 329c50d8ae3SPaolo Bonzini static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) 330c50d8ae3SPaolo Bonzini { 331c50d8ae3SPaolo Bonzini u64 kvm_gen, spte_gen, gen; 332c50d8ae3SPaolo Bonzini 333c50d8ae3SPaolo Bonzini gen = kvm_vcpu_memslots(vcpu)->generation; 334c50d8ae3SPaolo Bonzini if (unlikely(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS)) 335c50d8ae3SPaolo Bonzini return false; 336c50d8ae3SPaolo Bonzini 337c50d8ae3SPaolo Bonzini kvm_gen = gen & MMIO_SPTE_GEN_MASK; 338c50d8ae3SPaolo Bonzini spte_gen = get_mmio_spte_generation(spte); 339c50d8ae3SPaolo Bonzini 340c50d8ae3SPaolo Bonzini trace_check_mmio_spte(spte, kvm_gen, spte_gen); 341c50d8ae3SPaolo Bonzini return likely(kvm_gen == spte_gen); 342c50d8ae3SPaolo Bonzini } 343c50d8ae3SPaolo Bonzini 344c50d8ae3SPaolo Bonzini static int is_cpuid_PSE36(void) 345c50d8ae3SPaolo Bonzini { 346c50d8ae3SPaolo Bonzini return 1; 347c50d8ae3SPaolo Bonzini } 348c50d8ae3SPaolo Bonzini 349c50d8ae3SPaolo Bonzini #ifdef CONFIG_X86_64 350c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 351c50d8ae3SPaolo Bonzini { 352c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 353c50d8ae3SPaolo Bonzini } 354c50d8ae3SPaolo Bonzini 355c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 356c50d8ae3SPaolo Bonzini { 357c50d8ae3SPaolo Bonzini WRITE_ONCE(*sptep, spte); 358c50d8ae3SPaolo Bonzini } 359c50d8ae3SPaolo Bonzini 360c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 361c50d8ae3SPaolo Bonzini { 362c50d8ae3SPaolo Bonzini return xchg(sptep, spte); 363c50d8ae3SPaolo Bonzini } 364c50d8ae3SPaolo Bonzini 365c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 366c50d8ae3SPaolo Bonzini { 367c50d8ae3SPaolo Bonzini return READ_ONCE(*sptep); 368c50d8ae3SPaolo Bonzini } 369c50d8ae3SPaolo Bonzini #else 370c50d8ae3SPaolo Bonzini union split_spte { 371c50d8ae3SPaolo Bonzini struct { 372c50d8ae3SPaolo Bonzini u32 spte_low; 373c50d8ae3SPaolo Bonzini u32 spte_high; 374c50d8ae3SPaolo Bonzini }; 375c50d8ae3SPaolo Bonzini u64 spte; 376c50d8ae3SPaolo Bonzini }; 377c50d8ae3SPaolo Bonzini 378c50d8ae3SPaolo Bonzini static void count_spte_clear(u64 *sptep, u64 spte) 379c50d8ae3SPaolo Bonzini { 38057354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 381c50d8ae3SPaolo Bonzini 382c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(spte)) 383c50d8ae3SPaolo Bonzini return; 384c50d8ae3SPaolo Bonzini 385c50d8ae3SPaolo Bonzini /* Ensure the spte is completely set before we increase the count */ 386c50d8ae3SPaolo Bonzini smp_wmb(); 387c50d8ae3SPaolo Bonzini sp->clear_spte_count++; 388c50d8ae3SPaolo Bonzini } 389c50d8ae3SPaolo Bonzini 390c50d8ae3SPaolo Bonzini static void __set_spte(u64 *sptep, u64 spte) 391c50d8ae3SPaolo Bonzini { 392c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 393c50d8ae3SPaolo Bonzini 394c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 395c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 396c50d8ae3SPaolo Bonzini 397c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 398c50d8ae3SPaolo Bonzini 399c50d8ae3SPaolo Bonzini /* 400c50d8ae3SPaolo Bonzini * If we map the spte from nonpresent to present, We should store 401c50d8ae3SPaolo Bonzini * the high bits firstly, then set present bit, so cpu can not 402c50d8ae3SPaolo Bonzini * fetch this spte while we are setting the spte. 403c50d8ae3SPaolo Bonzini */ 404c50d8ae3SPaolo Bonzini smp_wmb(); 405c50d8ae3SPaolo Bonzini 406c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 407c50d8ae3SPaolo Bonzini } 408c50d8ae3SPaolo Bonzini 409c50d8ae3SPaolo Bonzini static void __update_clear_spte_fast(u64 *sptep, u64 spte) 410c50d8ae3SPaolo Bonzini { 411c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte; 412c50d8ae3SPaolo Bonzini 413c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 414c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 415c50d8ae3SPaolo Bonzini 416c50d8ae3SPaolo Bonzini WRITE_ONCE(ssptep->spte_low, sspte.spte_low); 417c50d8ae3SPaolo Bonzini 418c50d8ae3SPaolo Bonzini /* 419c50d8ae3SPaolo Bonzini * If we map the spte from present to nonpresent, we should clear 420c50d8ae3SPaolo Bonzini * present bit firstly to avoid vcpu fetch the old high bits. 421c50d8ae3SPaolo Bonzini */ 422c50d8ae3SPaolo Bonzini smp_wmb(); 423c50d8ae3SPaolo Bonzini 424c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 425c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 426c50d8ae3SPaolo Bonzini } 427c50d8ae3SPaolo Bonzini 428c50d8ae3SPaolo Bonzini static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) 429c50d8ae3SPaolo Bonzini { 430c50d8ae3SPaolo Bonzini union split_spte *ssptep, sspte, orig; 431c50d8ae3SPaolo Bonzini 432c50d8ae3SPaolo Bonzini ssptep = (union split_spte *)sptep; 433c50d8ae3SPaolo Bonzini sspte = (union split_spte)spte; 434c50d8ae3SPaolo Bonzini 435c50d8ae3SPaolo Bonzini /* xchg acts as a barrier before the setting of the high bits */ 436c50d8ae3SPaolo Bonzini orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low); 437c50d8ae3SPaolo Bonzini orig.spte_high = ssptep->spte_high; 438c50d8ae3SPaolo Bonzini ssptep->spte_high = sspte.spte_high; 439c50d8ae3SPaolo Bonzini count_spte_clear(sptep, spte); 440c50d8ae3SPaolo Bonzini 441c50d8ae3SPaolo Bonzini return orig.spte; 442c50d8ae3SPaolo Bonzini } 443c50d8ae3SPaolo Bonzini 444c50d8ae3SPaolo Bonzini /* 445c50d8ae3SPaolo Bonzini * The idea using the light way get the spte on x86_32 guest is from 446c50d8ae3SPaolo Bonzini * gup_get_pte (mm/gup.c). 447c50d8ae3SPaolo Bonzini * 448aed02fe3SSean Christopherson * An spte tlb flush may be pending, because kvm_set_pte_rmap 449c50d8ae3SPaolo Bonzini * coalesces them and we are running out of the MMU lock. Therefore 450c50d8ae3SPaolo Bonzini * we need to protect against in-progress updates of the spte. 451c50d8ae3SPaolo Bonzini * 452c50d8ae3SPaolo Bonzini * Reading the spte while an update is in progress may get the old value 453c50d8ae3SPaolo Bonzini * for the high part of the spte. The race is fine for a present->non-present 454c50d8ae3SPaolo Bonzini * change (because the high part of the spte is ignored for non-present spte), 455c50d8ae3SPaolo Bonzini * but for a present->present change we must reread the spte. 456c50d8ae3SPaolo Bonzini * 457c50d8ae3SPaolo Bonzini * All such changes are done in two steps (present->non-present and 458c50d8ae3SPaolo Bonzini * non-present->present), hence it is enough to count the number of 459c50d8ae3SPaolo Bonzini * present->non-present updates: if it changed while reading the spte, 460c50d8ae3SPaolo Bonzini * we might have hit the race. This is done using clear_spte_count. 461c50d8ae3SPaolo Bonzini */ 462c50d8ae3SPaolo Bonzini static u64 __get_spte_lockless(u64 *sptep) 463c50d8ae3SPaolo Bonzini { 46457354682SSean Christopherson struct kvm_mmu_page *sp = sptep_to_sp(sptep); 465c50d8ae3SPaolo Bonzini union split_spte spte, *orig = (union split_spte *)sptep; 466c50d8ae3SPaolo Bonzini int count; 467c50d8ae3SPaolo Bonzini 468c50d8ae3SPaolo Bonzini retry: 469c50d8ae3SPaolo Bonzini count = sp->clear_spte_count; 470c50d8ae3SPaolo Bonzini smp_rmb(); 471c50d8ae3SPaolo Bonzini 472c50d8ae3SPaolo Bonzini spte.spte_low = orig->spte_low; 473c50d8ae3SPaolo Bonzini smp_rmb(); 474c50d8ae3SPaolo Bonzini 475c50d8ae3SPaolo Bonzini spte.spte_high = orig->spte_high; 476c50d8ae3SPaolo Bonzini smp_rmb(); 477c50d8ae3SPaolo Bonzini 478c50d8ae3SPaolo Bonzini if (unlikely(spte.spte_low != orig->spte_low || 479c50d8ae3SPaolo Bonzini count != sp->clear_spte_count)) 480c50d8ae3SPaolo Bonzini goto retry; 481c50d8ae3SPaolo Bonzini 482c50d8ae3SPaolo Bonzini return spte.spte; 483c50d8ae3SPaolo Bonzini } 484c50d8ae3SPaolo Bonzini #endif 485c50d8ae3SPaolo Bonzini 486c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_set: 487c50d8ae3SPaolo Bonzini * Set the sptep from nonpresent to present. 488c50d8ae3SPaolo Bonzini * Note: the sptep being assigned *must* be either not present 489c50d8ae3SPaolo Bonzini * or in a state where the hardware will not attempt to update 490c50d8ae3SPaolo Bonzini * the spte. 491c50d8ae3SPaolo Bonzini */ 492c50d8ae3SPaolo Bonzini static void mmu_spte_set(u64 *sptep, u64 new_spte) 493c50d8ae3SPaolo Bonzini { 494c50d8ae3SPaolo Bonzini WARN_ON(is_shadow_present_pte(*sptep)); 495c50d8ae3SPaolo Bonzini __set_spte(sptep, new_spte); 496c50d8ae3SPaolo Bonzini } 497c50d8ae3SPaolo Bonzini 498c50d8ae3SPaolo Bonzini /* 499c50d8ae3SPaolo Bonzini * Update the SPTE (excluding the PFN), but do not track changes in its 500c50d8ae3SPaolo Bonzini * accessed/dirty status. 501c50d8ae3SPaolo Bonzini */ 502c50d8ae3SPaolo Bonzini static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) 503c50d8ae3SPaolo Bonzini { 504c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 505c50d8ae3SPaolo Bonzini 506c50d8ae3SPaolo Bonzini WARN_ON(!is_shadow_present_pte(new_spte)); 507115111efSDavid Matlack check_spte_writable_invariants(new_spte); 508c50d8ae3SPaolo Bonzini 509c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) { 510c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 511c50d8ae3SPaolo Bonzini return old_spte; 512c50d8ae3SPaolo Bonzini } 513c50d8ae3SPaolo Bonzini 514c50d8ae3SPaolo Bonzini if (!spte_has_volatile_bits(old_spte)) 515c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, new_spte); 516c50d8ae3SPaolo Bonzini else 517c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, new_spte); 518c50d8ae3SPaolo Bonzini 519c50d8ae3SPaolo Bonzini WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); 520c50d8ae3SPaolo Bonzini 521c50d8ae3SPaolo Bonzini return old_spte; 522c50d8ae3SPaolo Bonzini } 523c50d8ae3SPaolo Bonzini 524c50d8ae3SPaolo Bonzini /* Rules for using mmu_spte_update: 525c50d8ae3SPaolo Bonzini * Update the state bits, it means the mapped pfn is not changed. 526c50d8ae3SPaolo Bonzini * 52702844ac1SDavid Matlack * Whenever an MMU-writable SPTE is overwritten with a read-only SPTE, remote 52802844ac1SDavid Matlack * TLBs must be flushed. Otherwise rmap_write_protect will find a read-only 52902844ac1SDavid Matlack * spte, even though the writable spte might be cached on a CPU's TLB. 530c50d8ae3SPaolo Bonzini * 531c50d8ae3SPaolo Bonzini * Returns true if the TLB needs to be flushed 532c50d8ae3SPaolo Bonzini */ 533c50d8ae3SPaolo Bonzini static bool mmu_spte_update(u64 *sptep, u64 new_spte) 534c50d8ae3SPaolo Bonzini { 535c50d8ae3SPaolo Bonzini bool flush = false; 536c50d8ae3SPaolo Bonzini u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); 537c50d8ae3SPaolo Bonzini 538c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 539c50d8ae3SPaolo Bonzini return false; 540c50d8ae3SPaolo Bonzini 541c50d8ae3SPaolo Bonzini /* 542c50d8ae3SPaolo Bonzini * For the spte updated out of mmu-lock is safe, since 543c50d8ae3SPaolo Bonzini * we always atomically update it, see the comments in 544c50d8ae3SPaolo Bonzini * spte_has_volatile_bits(). 545c50d8ae3SPaolo Bonzini */ 546706c9c55SSean Christopherson if (is_mmu_writable_spte(old_spte) && 547c50d8ae3SPaolo Bonzini !is_writable_pte(new_spte)) 548c50d8ae3SPaolo Bonzini flush = true; 549c50d8ae3SPaolo Bonzini 550c50d8ae3SPaolo Bonzini /* 551c50d8ae3SPaolo Bonzini * Flush TLB when accessed/dirty states are changed in the page tables, 552c50d8ae3SPaolo Bonzini * to guarantee consistency between TLB and page tables. 553c50d8ae3SPaolo Bonzini */ 554c50d8ae3SPaolo Bonzini 555c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte) && !is_accessed_spte(new_spte)) { 556c50d8ae3SPaolo Bonzini flush = true; 557c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 558c50d8ae3SPaolo Bonzini } 559c50d8ae3SPaolo Bonzini 560c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)) { 561c50d8ae3SPaolo Bonzini flush = true; 562c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 563c50d8ae3SPaolo Bonzini } 564c50d8ae3SPaolo Bonzini 565c50d8ae3SPaolo Bonzini return flush; 566c50d8ae3SPaolo Bonzini } 567c50d8ae3SPaolo Bonzini 568c50d8ae3SPaolo Bonzini /* 569c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_track_bits: 570c50d8ae3SPaolo Bonzini * It sets the sptep from present to nonpresent, and track the 571c50d8ae3SPaolo Bonzini * state bits, it is used to clear the last level sptep. 5727fa2a347SSean Christopherson * Returns the old PTE. 573c50d8ae3SPaolo Bonzini */ 57435d539c3SSean Christopherson static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) 575c50d8ae3SPaolo Bonzini { 576c50d8ae3SPaolo Bonzini kvm_pfn_t pfn; 577c50d8ae3SPaolo Bonzini u64 old_spte = *sptep; 57871f51d2cSMingwei Zhang int level = sptep_to_sp(sptep)->role.level; 579b14b2690SSean Christopherson struct page *page; 580c50d8ae3SPaolo Bonzini 58154eb3ef5SSean Christopherson if (!is_shadow_present_pte(old_spte) || 58254eb3ef5SSean Christopherson !spte_has_volatile_bits(old_spte)) 583c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 584c50d8ae3SPaolo Bonzini else 585c50d8ae3SPaolo Bonzini old_spte = __update_clear_spte_slow(sptep, 0ull); 586c50d8ae3SPaolo Bonzini 587c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(old_spte)) 5887fa2a347SSean Christopherson return old_spte; 589c50d8ae3SPaolo Bonzini 59071f51d2cSMingwei Zhang kvm_update_page_stats(kvm, level, -1); 59171f51d2cSMingwei Zhang 592c50d8ae3SPaolo Bonzini pfn = spte_to_pfn(old_spte); 593c50d8ae3SPaolo Bonzini 594c50d8ae3SPaolo Bonzini /* 595b14b2690SSean Christopherson * KVM doesn't hold a reference to any pages mapped into the guest, and 596b14b2690SSean Christopherson * instead uses the mmu_notifier to ensure that KVM unmaps any pages 597b14b2690SSean Christopherson * before they are reclaimed. Sanity check that, if the pfn is backed 598b14b2690SSean Christopherson * by a refcounted page, the refcount is elevated. 599c50d8ae3SPaolo Bonzini */ 600b14b2690SSean Christopherson page = kvm_pfn_to_refcounted_page(pfn); 601b14b2690SSean Christopherson WARN_ON(page && !page_count(page)); 602c50d8ae3SPaolo Bonzini 603c50d8ae3SPaolo Bonzini if (is_accessed_spte(old_spte)) 604c50d8ae3SPaolo Bonzini kvm_set_pfn_accessed(pfn); 605c50d8ae3SPaolo Bonzini 606c50d8ae3SPaolo Bonzini if (is_dirty_spte(old_spte)) 607c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(pfn); 608c50d8ae3SPaolo Bonzini 6097fa2a347SSean Christopherson return old_spte; 610c50d8ae3SPaolo Bonzini } 611c50d8ae3SPaolo Bonzini 612c50d8ae3SPaolo Bonzini /* 613c50d8ae3SPaolo Bonzini * Rules for using mmu_spte_clear_no_track: 614c50d8ae3SPaolo Bonzini * Directly clear spte without caring the state bits of sptep, 615c50d8ae3SPaolo Bonzini * it is used to set the upper level spte. 616c50d8ae3SPaolo Bonzini */ 617c50d8ae3SPaolo Bonzini static void mmu_spte_clear_no_track(u64 *sptep) 618c50d8ae3SPaolo Bonzini { 619c50d8ae3SPaolo Bonzini __update_clear_spte_fast(sptep, 0ull); 620c50d8ae3SPaolo Bonzini } 621c50d8ae3SPaolo Bonzini 622c50d8ae3SPaolo Bonzini static u64 mmu_spte_get_lockless(u64 *sptep) 623c50d8ae3SPaolo Bonzini { 624c50d8ae3SPaolo Bonzini return __get_spte_lockless(sptep); 625c50d8ae3SPaolo Bonzini } 626c50d8ae3SPaolo Bonzini 627c50d8ae3SPaolo Bonzini /* Returns the Accessed status of the PTE and resets it at the same time. */ 628c50d8ae3SPaolo Bonzini static bool mmu_spte_age(u64 *sptep) 629c50d8ae3SPaolo Bonzini { 630c50d8ae3SPaolo Bonzini u64 spte = mmu_spte_get_lockless(sptep); 631c50d8ae3SPaolo Bonzini 632c50d8ae3SPaolo Bonzini if (!is_accessed_spte(spte)) 633c50d8ae3SPaolo Bonzini return false; 634c50d8ae3SPaolo Bonzini 635c50d8ae3SPaolo Bonzini if (spte_ad_enabled(spte)) { 636c50d8ae3SPaolo Bonzini clear_bit((ffs(shadow_accessed_mask) - 1), 637c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 638c50d8ae3SPaolo Bonzini } else { 639c50d8ae3SPaolo Bonzini /* 640c50d8ae3SPaolo Bonzini * Capture the dirty status of the page, so that it doesn't get 641c50d8ae3SPaolo Bonzini * lost when the SPTE is marked for access tracking. 642c50d8ae3SPaolo Bonzini */ 643c50d8ae3SPaolo Bonzini if (is_writable_pte(spte)) 644c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(spte)); 645c50d8ae3SPaolo Bonzini 646c50d8ae3SPaolo Bonzini spte = mark_spte_for_access_track(spte); 647c50d8ae3SPaolo Bonzini mmu_spte_update_no_track(sptep, spte); 648c50d8ae3SPaolo Bonzini } 649c50d8ae3SPaolo Bonzini 650c50d8ae3SPaolo Bonzini return true; 651c50d8ae3SPaolo Bonzini } 652c50d8ae3SPaolo Bonzini 65378fdd2f0SSean Christopherson static inline bool is_tdp_mmu_active(struct kvm_vcpu *vcpu) 65478fdd2f0SSean Christopherson { 65578fdd2f0SSean Christopherson return tdp_mmu_enabled && vcpu->arch.mmu->root_role.direct; 65678fdd2f0SSean Christopherson } 65778fdd2f0SSean Christopherson 658c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 659c50d8ae3SPaolo Bonzini { 66078fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 661c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_begin(); 662c5c8c7c5SDavid Matlack } else { 663c50d8ae3SPaolo Bonzini /* 664c50d8ae3SPaolo Bonzini * Prevent page table teardown by making any free-er wait during 665c50d8ae3SPaolo Bonzini * kvm_flush_remote_tlbs() IPI to all active vcpus. 666c50d8ae3SPaolo Bonzini */ 667c50d8ae3SPaolo Bonzini local_irq_disable(); 668c50d8ae3SPaolo Bonzini 669c50d8ae3SPaolo Bonzini /* 670c50d8ae3SPaolo Bonzini * Make sure a following spte read is not reordered ahead of the write 671c50d8ae3SPaolo Bonzini * to vcpu->mode. 672c50d8ae3SPaolo Bonzini */ 673c50d8ae3SPaolo Bonzini smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); 674c50d8ae3SPaolo Bonzini } 675c5c8c7c5SDavid Matlack } 676c50d8ae3SPaolo Bonzini 677c50d8ae3SPaolo Bonzini static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) 678c50d8ae3SPaolo Bonzini { 67978fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) { 680c5c8c7c5SDavid Matlack kvm_tdp_mmu_walk_lockless_end(); 681c5c8c7c5SDavid Matlack } else { 682c50d8ae3SPaolo Bonzini /* 683c50d8ae3SPaolo Bonzini * Make sure the write to vcpu->mode is not reordered in front of 684c50d8ae3SPaolo Bonzini * reads to sptes. If it does, kvm_mmu_commit_zap_page() can see us 685c50d8ae3SPaolo Bonzini * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. 686c50d8ae3SPaolo Bonzini */ 687c50d8ae3SPaolo Bonzini smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); 688c50d8ae3SPaolo Bonzini local_irq_enable(); 689c50d8ae3SPaolo Bonzini } 690c5c8c7c5SDavid Matlack } 691c50d8ae3SPaolo Bonzini 692378f5cd6SSean Christopherson static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) 693c50d8ae3SPaolo Bonzini { 694c50d8ae3SPaolo Bonzini int r; 695c50d8ae3SPaolo Bonzini 696531281adSSean Christopherson /* 1 rmap, 1 parent PTE per level, and the prefetched rmaps. */ 69794ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, 698531281adSSean Christopherson 1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM); 699c50d8ae3SPaolo Bonzini if (r) 700c50d8ae3SPaolo Bonzini return r; 70194ce87efSSean Christopherson r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, 702171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 703171a90d7SSean Christopherson if (r) 704171a90d7SSean Christopherson return r; 705378f5cd6SSean Christopherson if (maybe_indirect) { 7066a97575dSDavid Matlack r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache, 707171a90d7SSean Christopherson PT64_ROOT_MAX_LEVEL); 708c50d8ae3SPaolo Bonzini if (r) 709c50d8ae3SPaolo Bonzini return r; 710378f5cd6SSean Christopherson } 71194ce87efSSean Christopherson return kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 712531281adSSean Christopherson PT64_ROOT_MAX_LEVEL); 713c50d8ae3SPaolo Bonzini } 714c50d8ae3SPaolo Bonzini 715c50d8ae3SPaolo Bonzini static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) 716c50d8ae3SPaolo Bonzini { 71794ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache); 71894ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache); 7196a97575dSDavid Matlack kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache); 72094ce87efSSean Christopherson kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); 721c50d8ae3SPaolo Bonzini } 722c50d8ae3SPaolo Bonzini 723c50d8ae3SPaolo Bonzini static void mmu_free_pte_list_desc(struct pte_list_desc *pte_list_desc) 724c50d8ae3SPaolo Bonzini { 725c50d8ae3SPaolo Bonzini kmem_cache_free(pte_list_desc_cache, pte_list_desc); 726c50d8ae3SPaolo Bonzini } 727c50d8ae3SPaolo Bonzini 7286a97575dSDavid Matlack static bool sp_has_gptes(struct kvm_mmu_page *sp); 7296a97575dSDavid Matlack 730c50d8ae3SPaolo Bonzini static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index) 731c50d8ae3SPaolo Bonzini { 73284e5ffd0SLai Jiangshan if (sp->role.passthrough) 73384e5ffd0SLai Jiangshan return sp->gfn; 73484e5ffd0SLai Jiangshan 735c50d8ae3SPaolo Bonzini if (!sp->role.direct) 7366a97575dSDavid Matlack return sp->shadowed_translation[index] >> PAGE_SHIFT; 737c50d8ae3SPaolo Bonzini 7382ca3129eSSean Christopherson return sp->gfn + (index << ((sp->role.level - 1) * SPTE_LEVEL_BITS)); 739c50d8ae3SPaolo Bonzini } 740c50d8ae3SPaolo Bonzini 7416a97575dSDavid Matlack /* 7426a97575dSDavid Matlack * For leaf SPTEs, fetch the *guest* access permissions being shadowed. Note 7436a97575dSDavid Matlack * that the SPTE itself may have a more constrained access permissions that 7446a97575dSDavid Matlack * what the guest enforces. For example, a guest may create an executable 7456a97575dSDavid Matlack * huge PTE but KVM may disallow execution to mitigate iTLB multihit. 7466a97575dSDavid Matlack */ 7476a97575dSDavid Matlack static u32 kvm_mmu_page_get_access(struct kvm_mmu_page *sp, int index) 748c50d8ae3SPaolo Bonzini { 7496a97575dSDavid Matlack if (sp_has_gptes(sp)) 7506a97575dSDavid Matlack return sp->shadowed_translation[index] & ACC_ALL; 7516a97575dSDavid Matlack 7526a97575dSDavid Matlack /* 7536a97575dSDavid Matlack * For direct MMUs (e.g. TDP or non-paging guests) or passthrough SPs, 7546a97575dSDavid Matlack * KVM is not shadowing any guest page tables, so the "guest access 7556a97575dSDavid Matlack * permissions" are just ACC_ALL. 7566a97575dSDavid Matlack * 7576a97575dSDavid Matlack * For direct SPs in indirect MMUs (shadow paging), i.e. when KVM 7586a97575dSDavid Matlack * is shadowing a guest huge page with small pages, the guest access 7596a97575dSDavid Matlack * permissions being shadowed are the access permissions of the huge 7606a97575dSDavid Matlack * page. 7616a97575dSDavid Matlack * 7626a97575dSDavid Matlack * In both cases, sp->role.access contains the correct access bits. 7636a97575dSDavid Matlack */ 7646a97575dSDavid Matlack return sp->role.access; 7656a97575dSDavid Matlack } 7666a97575dSDavid Matlack 76772ae5822SSean Christopherson static void kvm_mmu_page_set_translation(struct kvm_mmu_page *sp, int index, 76872ae5822SSean Christopherson gfn_t gfn, unsigned int access) 7696a97575dSDavid Matlack { 7706a97575dSDavid Matlack if (sp_has_gptes(sp)) { 7716a97575dSDavid Matlack sp->shadowed_translation[index] = (gfn << PAGE_SHIFT) | access; 77284e5ffd0SLai Jiangshan return; 77384e5ffd0SLai Jiangshan } 77484e5ffd0SLai Jiangshan 7756a97575dSDavid Matlack WARN_ONCE(access != kvm_mmu_page_get_access(sp, index), 7766a97575dSDavid Matlack "access mismatch under %s page %llx (expected %u, got %u)\n", 7776a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7786a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_access(sp, index), access); 7796a97575dSDavid Matlack 7806a97575dSDavid Matlack WARN_ONCE(gfn != kvm_mmu_page_get_gfn(sp, index), 7816a97575dSDavid Matlack "gfn mismatch under %s page %llx (expected %llx, got %llx)\n", 7826a97575dSDavid Matlack sp->role.passthrough ? "passthrough" : "direct", 7836a97575dSDavid Matlack sp->gfn, kvm_mmu_page_get_gfn(sp, index), gfn); 784c50d8ae3SPaolo Bonzini } 785c50d8ae3SPaolo Bonzini 78672ae5822SSean Christopherson static void kvm_mmu_page_set_access(struct kvm_mmu_page *sp, int index, 78772ae5822SSean Christopherson unsigned int access) 7886a97575dSDavid Matlack { 7896a97575dSDavid Matlack gfn_t gfn = kvm_mmu_page_get_gfn(sp, index); 7906a97575dSDavid Matlack 7916a97575dSDavid Matlack kvm_mmu_page_set_translation(sp, index, gfn, access); 792c50d8ae3SPaolo Bonzini } 793c50d8ae3SPaolo Bonzini 794c50d8ae3SPaolo Bonzini /* 795c50d8ae3SPaolo Bonzini * Return the pointer to the large page information for a given gfn, 796c50d8ae3SPaolo Bonzini * handling slots that are not large page aligned. 797c50d8ae3SPaolo Bonzini */ 798c50d8ae3SPaolo Bonzini static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, 7998ca6f063SBen Gardon const struct kvm_memory_slot *slot, int level) 800c50d8ae3SPaolo Bonzini { 801c50d8ae3SPaolo Bonzini unsigned long idx; 802c50d8ae3SPaolo Bonzini 803c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 804c50d8ae3SPaolo Bonzini return &slot->arch.lpage_info[level - 2][idx]; 805c50d8ae3SPaolo Bonzini } 806c50d8ae3SPaolo Bonzini 807269e9552SHamza Mahfooz static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot, 808c50d8ae3SPaolo Bonzini gfn_t gfn, int count) 809c50d8ae3SPaolo Bonzini { 810c50d8ae3SPaolo Bonzini struct kvm_lpage_info *linfo; 811c50d8ae3SPaolo Bonzini int i; 812c50d8ae3SPaolo Bonzini 8133bae0459SSean Christopherson for (i = PG_LEVEL_2M; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 814c50d8ae3SPaolo Bonzini linfo = lpage_info_slot(gfn, slot, i); 815c50d8ae3SPaolo Bonzini linfo->disallow_lpage += count; 816c50d8ae3SPaolo Bonzini WARN_ON(linfo->disallow_lpage < 0); 817c50d8ae3SPaolo Bonzini } 818c50d8ae3SPaolo Bonzini } 819c50d8ae3SPaolo Bonzini 820269e9552SHamza Mahfooz void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 821c50d8ae3SPaolo Bonzini { 822c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, 1); 823c50d8ae3SPaolo Bonzini } 824c50d8ae3SPaolo Bonzini 825269e9552SHamza Mahfooz void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn) 826c50d8ae3SPaolo Bonzini { 827c50d8ae3SPaolo Bonzini update_gfn_disallow_lpage_count(slot, gfn, -1); 828c50d8ae3SPaolo Bonzini } 829c50d8ae3SPaolo Bonzini 830c50d8ae3SPaolo Bonzini static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 831c50d8ae3SPaolo Bonzini { 832c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 833c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 834c50d8ae3SPaolo Bonzini gfn_t gfn; 835c50d8ae3SPaolo Bonzini 836c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages++; 837c50d8ae3SPaolo Bonzini gfn = sp->gfn; 838c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 839c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 840c50d8ae3SPaolo Bonzini 841c50d8ae3SPaolo Bonzini /* the non-leaf shadow pages are keeping readonly. */ 8423bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 843c50d8ae3SPaolo Bonzini return kvm_slot_page_track_add_page(kvm, slot, gfn, 844c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 845c50d8ae3SPaolo Bonzini 846c50d8ae3SPaolo Bonzini kvm_mmu_gfn_disallow_lpage(slot, gfn); 847be911771SDavid Matlack 848be911771SDavid Matlack if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn, PG_LEVEL_4K)) 8494ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, PG_LEVEL_4K); 850c50d8ae3SPaolo Bonzini } 851c50d8ae3SPaolo Bonzini 85261f94478SSean Christopherson void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 853c50d8ae3SPaolo Bonzini { 854428e9216SSean Christopherson /* 855428e9216SSean Christopherson * If it's possible to replace the shadow page with an NX huge page, 856428e9216SSean Christopherson * i.e. if the shadow page is the only thing currently preventing KVM 857428e9216SSean Christopherson * from using a huge page, add the shadow page to the list of "to be 858428e9216SSean Christopherson * zapped for NX recovery" pages. Note, the shadow page can already be 859428e9216SSean Christopherson * on the list if KVM is reusing an existing shadow page, i.e. if KVM 860428e9216SSean Christopherson * links a shadow page at multiple points. 861428e9216SSean Christopherson */ 86261f94478SSean Christopherson if (!list_empty(&sp->possible_nx_huge_page_link)) 863c50d8ae3SPaolo Bonzini return; 864c50d8ae3SPaolo Bonzini 865c50d8ae3SPaolo Bonzini ++kvm->stat.nx_lpage_splits; 86655c510e2SSean Christopherson list_add_tail(&sp->possible_nx_huge_page_link, 86755c510e2SSean Christopherson &kvm->arch.possible_nx_huge_pages); 868c50d8ae3SPaolo Bonzini } 869c50d8ae3SPaolo Bonzini 87061f94478SSean Christopherson static void account_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp, 87161f94478SSean Christopherson bool nx_huge_page_possible) 87261f94478SSean Christopherson { 87361f94478SSean Christopherson sp->nx_huge_page_disallowed = true; 87461f94478SSean Christopherson 87561f94478SSean Christopherson if (nx_huge_page_possible) 87661f94478SSean Christopherson track_possible_nx_huge_page(kvm, sp); 877c50d8ae3SPaolo Bonzini } 878c50d8ae3SPaolo Bonzini 879c50d8ae3SPaolo Bonzini static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 880c50d8ae3SPaolo Bonzini { 881c50d8ae3SPaolo Bonzini struct kvm_memslots *slots; 882c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 883c50d8ae3SPaolo Bonzini gfn_t gfn; 884c50d8ae3SPaolo Bonzini 885c50d8ae3SPaolo Bonzini kvm->arch.indirect_shadow_pages--; 886c50d8ae3SPaolo Bonzini gfn = sp->gfn; 887c50d8ae3SPaolo Bonzini slots = kvm_memslots_for_spte_role(kvm, sp->role); 888c50d8ae3SPaolo Bonzini slot = __gfn_to_memslot(slots, gfn); 8893bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 890c50d8ae3SPaolo Bonzini return kvm_slot_page_track_remove_page(kvm, slot, gfn, 891c50d8ae3SPaolo Bonzini KVM_PAGE_TRACK_WRITE); 892c50d8ae3SPaolo Bonzini 893c50d8ae3SPaolo Bonzini kvm_mmu_gfn_allow_lpage(slot, gfn); 894c50d8ae3SPaolo Bonzini } 895c50d8ae3SPaolo Bonzini 89661f94478SSean Christopherson void untrack_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 897c50d8ae3SPaolo Bonzini { 89855c510e2SSean Christopherson if (list_empty(&sp->possible_nx_huge_page_link)) 899428e9216SSean Christopherson return; 900428e9216SSean Christopherson 901c50d8ae3SPaolo Bonzini --kvm->stat.nx_lpage_splits; 90255c510e2SSean Christopherson list_del_init(&sp->possible_nx_huge_page_link); 903c50d8ae3SPaolo Bonzini } 904c50d8ae3SPaolo Bonzini 90561f94478SSean Christopherson static void unaccount_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp) 90661f94478SSean Christopherson { 90761f94478SSean Christopherson sp->nx_huge_page_disallowed = false; 90861f94478SSean Christopherson 90961f94478SSean Christopherson untrack_possible_nx_huge_page(kvm, sp); 910c50d8ae3SPaolo Bonzini } 911c50d8ae3SPaolo Bonzini 912f3d90f90SSean Christopherson static struct kvm_memory_slot *gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, 913f3d90f90SSean Christopherson gfn_t gfn, 914c50d8ae3SPaolo Bonzini bool no_dirty_log) 915c50d8ae3SPaolo Bonzini { 916c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 917c50d8ae3SPaolo Bonzini 918c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 91991b0d268SPaolo Bonzini if (!slot || slot->flags & KVM_MEMSLOT_INVALID) 92091b0d268SPaolo Bonzini return NULL; 921044c59c4SPeter Xu if (no_dirty_log && kvm_slot_dirty_track_enabled(slot)) 92291b0d268SPaolo Bonzini return NULL; 923c50d8ae3SPaolo Bonzini 924c50d8ae3SPaolo Bonzini return slot; 925c50d8ae3SPaolo Bonzini } 926c50d8ae3SPaolo Bonzini 927c50d8ae3SPaolo Bonzini /* 928c50d8ae3SPaolo Bonzini * About rmap_head encoding: 929c50d8ae3SPaolo Bonzini * 930c50d8ae3SPaolo Bonzini * If the bit zero of rmap_head->val is clear, then it points to the only spte 931c50d8ae3SPaolo Bonzini * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct 932c50d8ae3SPaolo Bonzini * pte_list_desc containing more mappings. 933c50d8ae3SPaolo Bonzini */ 934c50d8ae3SPaolo Bonzini 935c50d8ae3SPaolo Bonzini /* 936c50d8ae3SPaolo Bonzini * Returns the number of pointers in the rmap chain, not counting the new one. 937c50d8ae3SPaolo Bonzini */ 9382ff9039aSDavid Matlack static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte, 939c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head) 940c50d8ae3SPaolo Bonzini { 941c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 94213236e25SPeter Xu int count = 0; 943c50d8ae3SPaolo Bonzini 944c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 945805a0f83SStephen Zhang rmap_printk("%p %llx 0->1\n", spte, *spte); 946c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)spte; 947c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 948805a0f83SStephen Zhang rmap_printk("%p %llx 1->many\n", spte, *spte); 9492ff9039aSDavid Matlack desc = kvm_mmu_memory_cache_alloc(cache); 950c50d8ae3SPaolo Bonzini desc->sptes[0] = (u64 *)rmap_head->val; 951c50d8ae3SPaolo Bonzini desc->sptes[1] = spte; 95213236e25SPeter Xu desc->spte_count = 2; 953141705b7SLai Jiangshan desc->tail_count = 0; 954c50d8ae3SPaolo Bonzini rmap_head->val = (unsigned long)desc | 1; 955c50d8ae3SPaolo Bonzini ++count; 956c50d8ae3SPaolo Bonzini } else { 957805a0f83SStephen Zhang rmap_printk("%p %llx many->many\n", spte, *spte); 958c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 959141705b7SLai Jiangshan count = desc->tail_count + desc->spte_count; 960141705b7SLai Jiangshan 961141705b7SLai Jiangshan /* 962141705b7SLai Jiangshan * If the previous head is full, allocate a new head descriptor 963141705b7SLai Jiangshan * as tail descriptors are always kept full. 964141705b7SLai Jiangshan */ 965141705b7SLai Jiangshan if (desc->spte_count == PTE_LIST_EXT) { 966141705b7SLai Jiangshan desc = kvm_mmu_memory_cache_alloc(cache); 967141705b7SLai Jiangshan desc->more = (struct pte_list_desc *)(rmap_head->val & ~1ul); 96813236e25SPeter Xu desc->spte_count = 0; 969141705b7SLai Jiangshan desc->tail_count = count; 970141705b7SLai Jiangshan rmap_head->val = (unsigned long)desc | 1; 971c6c4f961SLi RongQing } 97213236e25SPeter Xu desc->sptes[desc->spte_count++] = spte; 973c50d8ae3SPaolo Bonzini } 974c50d8ae3SPaolo Bonzini return count; 975c50d8ae3SPaolo Bonzini } 976c50d8ae3SPaolo Bonzini 977f3d90f90SSean Christopherson static void pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head, 978141705b7SLai Jiangshan struct pte_list_desc *desc, int i) 979c50d8ae3SPaolo Bonzini { 980141705b7SLai Jiangshan struct pte_list_desc *head_desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 981141705b7SLai Jiangshan int j = head_desc->spte_count - 1; 982c50d8ae3SPaolo Bonzini 983141705b7SLai Jiangshan /* 984141705b7SLai Jiangshan * The head descriptor should never be empty. A new head is added only 985141705b7SLai Jiangshan * when adding an entry and the previous head is full, and heads are 986141705b7SLai Jiangshan * removed (this flow) when they become empty. 987141705b7SLai Jiangshan */ 988141705b7SLai Jiangshan BUG_ON(j < 0); 989141705b7SLai Jiangshan 990141705b7SLai Jiangshan /* 991141705b7SLai Jiangshan * Replace the to-be-freed SPTE with the last valid entry from the head 992141705b7SLai Jiangshan * descriptor to ensure that tail descriptors are full at all times. 993141705b7SLai Jiangshan * Note, this also means that tail_count is stable for each descriptor. 994141705b7SLai Jiangshan */ 995141705b7SLai Jiangshan desc->sptes[i] = head_desc->sptes[j]; 996141705b7SLai Jiangshan head_desc->sptes[j] = NULL; 997141705b7SLai Jiangshan head_desc->spte_count--; 998141705b7SLai Jiangshan if (head_desc->spte_count) 999c50d8ae3SPaolo Bonzini return; 1000141705b7SLai Jiangshan 1001141705b7SLai Jiangshan /* 1002141705b7SLai Jiangshan * The head descriptor is empty. If there are no tail descriptors, 1003141705b7SLai Jiangshan * nullify the rmap head to mark the list as emtpy, else point the rmap 1004141705b7SLai Jiangshan * head at the next descriptor, i.e. the new head. 1005141705b7SLai Jiangshan */ 1006141705b7SLai Jiangshan if (!head_desc->more) 1007fe3c2b4cSMiaohe Lin rmap_head->val = 0; 1008c50d8ae3SPaolo Bonzini else 1009141705b7SLai Jiangshan rmap_head->val = (unsigned long)head_desc->more | 1; 1010141705b7SLai Jiangshan mmu_free_pte_list_desc(head_desc); 1011c50d8ae3SPaolo Bonzini } 1012c50d8ae3SPaolo Bonzini 10133c2e1037SSean Christopherson static void pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) 1014c50d8ae3SPaolo Bonzini { 1015c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; 1016c50d8ae3SPaolo Bonzini int i; 1017c50d8ae3SPaolo Bonzini 1018c50d8ae3SPaolo Bonzini if (!rmap_head->val) { 1019c50d8ae3SPaolo Bonzini pr_err("%s: %p 0->BUG\n", __func__, spte); 1020c50d8ae3SPaolo Bonzini BUG(); 1021c50d8ae3SPaolo Bonzini } else if (!(rmap_head->val & 1)) { 1022805a0f83SStephen Zhang rmap_printk("%p 1->0\n", spte); 1023c50d8ae3SPaolo Bonzini if ((u64 *)rmap_head->val != spte) { 1024c50d8ae3SPaolo Bonzini pr_err("%s: %p 1->BUG\n", __func__, spte); 1025c50d8ae3SPaolo Bonzini BUG(); 1026c50d8ae3SPaolo Bonzini } 1027c50d8ae3SPaolo Bonzini rmap_head->val = 0; 1028c50d8ae3SPaolo Bonzini } else { 1029805a0f83SStephen Zhang rmap_printk("%p many->many\n", spte); 1030c50d8ae3SPaolo Bonzini desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1031c50d8ae3SPaolo Bonzini while (desc) { 103213236e25SPeter Xu for (i = 0; i < desc->spte_count; ++i) { 1033c50d8ae3SPaolo Bonzini if (desc->sptes[i] == spte) { 1034141705b7SLai Jiangshan pte_list_desc_remove_entry(rmap_head, desc, i); 1035c50d8ae3SPaolo Bonzini return; 1036c50d8ae3SPaolo Bonzini } 1037c50d8ae3SPaolo Bonzini } 1038c50d8ae3SPaolo Bonzini desc = desc->more; 1039c50d8ae3SPaolo Bonzini } 1040c50d8ae3SPaolo Bonzini pr_err("%s: %p many->many\n", __func__, spte); 1041c50d8ae3SPaolo Bonzini BUG(); 1042c50d8ae3SPaolo Bonzini } 1043c50d8ae3SPaolo Bonzini } 1044c50d8ae3SPaolo Bonzini 10459202aee8SSean Christopherson static void kvm_zap_one_rmap_spte(struct kvm *kvm, 10469202aee8SSean Christopherson struct kvm_rmap_head *rmap_head, u64 *sptep) 1047c50d8ae3SPaolo Bonzini { 104871f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 10493c2e1037SSean Christopherson pte_list_remove(sptep, rmap_head); 1050c50d8ae3SPaolo Bonzini } 1051c50d8ae3SPaolo Bonzini 10529202aee8SSean Christopherson /* Return true if at least one SPTE was zapped, false otherwise */ 10539202aee8SSean Christopherson static bool kvm_zap_all_rmap_sptes(struct kvm *kvm, 10549202aee8SSean Christopherson struct kvm_rmap_head *rmap_head) 1055a75b5404SPeter Xu { 1056a75b5404SPeter Xu struct pte_list_desc *desc, *next; 1057a75b5404SPeter Xu int i; 1058a75b5404SPeter Xu 1059a75b5404SPeter Xu if (!rmap_head->val) 1060a75b5404SPeter Xu return false; 1061a75b5404SPeter Xu 1062a75b5404SPeter Xu if (!(rmap_head->val & 1)) { 106371f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val); 1064a75b5404SPeter Xu goto out; 1065a75b5404SPeter Xu } 1066a75b5404SPeter Xu 1067a75b5404SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1068a75b5404SPeter Xu 1069a75b5404SPeter Xu for (; desc; desc = next) { 1070a75b5404SPeter Xu for (i = 0; i < desc->spte_count; i++) 107171f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, desc->sptes[i]); 1072a75b5404SPeter Xu next = desc->more; 1073a75b5404SPeter Xu mmu_free_pte_list_desc(desc); 1074a75b5404SPeter Xu } 1075a75b5404SPeter Xu out: 1076a75b5404SPeter Xu /* rmap_head is meaningless now, remember to reset it */ 1077a75b5404SPeter Xu rmap_head->val = 0; 1078a75b5404SPeter Xu return true; 1079a75b5404SPeter Xu } 1080a75b5404SPeter Xu 10813bcd0662SPeter Xu unsigned int pte_list_count(struct kvm_rmap_head *rmap_head) 10823bcd0662SPeter Xu { 10833bcd0662SPeter Xu struct pte_list_desc *desc; 10843bcd0662SPeter Xu 10853bcd0662SPeter Xu if (!rmap_head->val) 10863bcd0662SPeter Xu return 0; 10873bcd0662SPeter Xu else if (!(rmap_head->val & 1)) 10883bcd0662SPeter Xu return 1; 10893bcd0662SPeter Xu 10903bcd0662SPeter Xu desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1091141705b7SLai Jiangshan return desc->tail_count + desc->spte_count; 10923bcd0662SPeter Xu } 10933bcd0662SPeter Xu 109493e083d4SDavid Matlack static struct kvm_rmap_head *gfn_to_rmap(gfn_t gfn, int level, 1095269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1096c50d8ae3SPaolo Bonzini { 1097c50d8ae3SPaolo Bonzini unsigned long idx; 1098c50d8ae3SPaolo Bonzini 1099c50d8ae3SPaolo Bonzini idx = gfn_to_index(gfn, slot->base_gfn, level); 11003bae0459SSean Christopherson return &slot->arch.rmap[level - PG_LEVEL_4K][idx]; 1101c50d8ae3SPaolo Bonzini } 1102c50d8ae3SPaolo Bonzini 1103c50d8ae3SPaolo Bonzini static void rmap_remove(struct kvm *kvm, u64 *spte) 1104c50d8ae3SPaolo Bonzini { 1105601f8af0SDavid Matlack struct kvm_memslots *slots; 1106601f8af0SDavid Matlack struct kvm_memory_slot *slot; 1107c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1108c50d8ae3SPaolo Bonzini gfn_t gfn; 1109c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1110c50d8ae3SPaolo Bonzini 111157354682SSean Christopherson sp = sptep_to_sp(spte); 111279e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(spte)); 1113601f8af0SDavid Matlack 1114601f8af0SDavid Matlack /* 111568be1306SDavid Matlack * Unlike rmap_add, rmap_remove does not run in the context of a vCPU 111668be1306SDavid Matlack * so we have to determine which memslots to use based on context 111768be1306SDavid Matlack * information in sp->role. 1118601f8af0SDavid Matlack */ 1119601f8af0SDavid Matlack slots = kvm_memslots_for_spte_role(kvm, sp->role); 1120601f8af0SDavid Matlack 1121601f8af0SDavid Matlack slot = __gfn_to_memslot(slots, gfn); 112293e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 1123601f8af0SDavid Matlack 11243c2e1037SSean Christopherson pte_list_remove(spte, rmap_head); 1125c50d8ae3SPaolo Bonzini } 1126c50d8ae3SPaolo Bonzini 1127c50d8ae3SPaolo Bonzini /* 1128c50d8ae3SPaolo Bonzini * Used by the following functions to iterate through the sptes linked by a 1129c50d8ae3SPaolo Bonzini * rmap. All fields are private and not assumed to be used outside. 1130c50d8ae3SPaolo Bonzini */ 1131c50d8ae3SPaolo Bonzini struct rmap_iterator { 1132c50d8ae3SPaolo Bonzini /* private fields */ 1133c50d8ae3SPaolo Bonzini struct pte_list_desc *desc; /* holds the sptep if not NULL */ 1134c50d8ae3SPaolo Bonzini int pos; /* index of the sptep */ 1135c50d8ae3SPaolo Bonzini }; 1136c50d8ae3SPaolo Bonzini 1137c50d8ae3SPaolo Bonzini /* 1138c50d8ae3SPaolo Bonzini * Iteration must be started by this function. This should also be used after 1139c50d8ae3SPaolo Bonzini * removing/dropping sptes from the rmap link because in such cases the 11400a03cbdaSMiaohe Lin * information in the iterator may not be valid. 1141c50d8ae3SPaolo Bonzini * 1142c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1143c50d8ae3SPaolo Bonzini */ 1144c50d8ae3SPaolo Bonzini static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head, 1145c50d8ae3SPaolo Bonzini struct rmap_iterator *iter) 1146c50d8ae3SPaolo Bonzini { 1147c50d8ae3SPaolo Bonzini u64 *sptep; 1148c50d8ae3SPaolo Bonzini 1149c50d8ae3SPaolo Bonzini if (!rmap_head->val) 1150c50d8ae3SPaolo Bonzini return NULL; 1151c50d8ae3SPaolo Bonzini 1152c50d8ae3SPaolo Bonzini if (!(rmap_head->val & 1)) { 1153c50d8ae3SPaolo Bonzini iter->desc = NULL; 1154c50d8ae3SPaolo Bonzini sptep = (u64 *)rmap_head->val; 1155c50d8ae3SPaolo Bonzini goto out; 1156c50d8ae3SPaolo Bonzini } 1157c50d8ae3SPaolo Bonzini 1158c50d8ae3SPaolo Bonzini iter->desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); 1159c50d8ae3SPaolo Bonzini iter->pos = 0; 1160c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1161c50d8ae3SPaolo Bonzini out: 1162c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1163c50d8ae3SPaolo Bonzini return sptep; 1164c50d8ae3SPaolo Bonzini } 1165c50d8ae3SPaolo Bonzini 1166c50d8ae3SPaolo Bonzini /* 1167c50d8ae3SPaolo Bonzini * Must be used with a valid iterator: e.g. after rmap_get_first(). 1168c50d8ae3SPaolo Bonzini * 1169c50d8ae3SPaolo Bonzini * Returns sptep if found, NULL otherwise. 1170c50d8ae3SPaolo Bonzini */ 1171c50d8ae3SPaolo Bonzini static u64 *rmap_get_next(struct rmap_iterator *iter) 1172c50d8ae3SPaolo Bonzini { 1173c50d8ae3SPaolo Bonzini u64 *sptep; 1174c50d8ae3SPaolo Bonzini 1175c50d8ae3SPaolo Bonzini if (iter->desc) { 1176c50d8ae3SPaolo Bonzini if (iter->pos < PTE_LIST_EXT - 1) { 1177c50d8ae3SPaolo Bonzini ++iter->pos; 1178c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1179c50d8ae3SPaolo Bonzini if (sptep) 1180c50d8ae3SPaolo Bonzini goto out; 1181c50d8ae3SPaolo Bonzini } 1182c50d8ae3SPaolo Bonzini 1183c50d8ae3SPaolo Bonzini iter->desc = iter->desc->more; 1184c50d8ae3SPaolo Bonzini 1185c50d8ae3SPaolo Bonzini if (iter->desc) { 1186c50d8ae3SPaolo Bonzini iter->pos = 0; 1187c50d8ae3SPaolo Bonzini /* desc->sptes[0] cannot be NULL */ 1188c50d8ae3SPaolo Bonzini sptep = iter->desc->sptes[iter->pos]; 1189c50d8ae3SPaolo Bonzini goto out; 1190c50d8ae3SPaolo Bonzini } 1191c50d8ae3SPaolo Bonzini } 1192c50d8ae3SPaolo Bonzini 1193c50d8ae3SPaolo Bonzini return NULL; 1194c50d8ae3SPaolo Bonzini out: 1195c50d8ae3SPaolo Bonzini BUG_ON(!is_shadow_present_pte(*sptep)); 1196c50d8ae3SPaolo Bonzini return sptep; 1197c50d8ae3SPaolo Bonzini } 1198c50d8ae3SPaolo Bonzini 1199c50d8ae3SPaolo Bonzini #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ 1200c50d8ae3SPaolo Bonzini for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ 1201c50d8ae3SPaolo Bonzini _spte_; _spte_ = rmap_get_next(_iter_)) 1202c50d8ae3SPaolo Bonzini 1203c50d8ae3SPaolo Bonzini static void drop_spte(struct kvm *kvm, u64 *sptep) 1204c50d8ae3SPaolo Bonzini { 120571f51d2cSMingwei Zhang u64 old_spte = mmu_spte_clear_track_bits(kvm, sptep); 12067fa2a347SSean Christopherson 12077fa2a347SSean Christopherson if (is_shadow_present_pte(old_spte)) 1208c50d8ae3SPaolo Bonzini rmap_remove(kvm, sptep); 1209c50d8ae3SPaolo Bonzini } 1210c50d8ae3SPaolo Bonzini 121103787394SPaolo Bonzini static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 1212c50d8ae3SPaolo Bonzini { 12130cd8dc73SPaolo Bonzini struct kvm_mmu_page *sp; 12140cd8dc73SPaolo Bonzini 12150cd8dc73SPaolo Bonzini sp = sptep_to_sp(sptep); 12160cd8dc73SPaolo Bonzini WARN_ON(sp->role.level == PG_LEVEL_4K); 12170cd8dc73SPaolo Bonzini 1218c50d8ae3SPaolo Bonzini drop_spte(kvm, sptep); 121903787394SPaolo Bonzini 122003787394SPaolo Bonzini if (flush) 12211b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 1222c50d8ae3SPaolo Bonzini } 1223c50d8ae3SPaolo Bonzini 1224c50d8ae3SPaolo Bonzini /* 1225c50d8ae3SPaolo Bonzini * Write-protect on the specified @sptep, @pt_protect indicates whether 1226c50d8ae3SPaolo Bonzini * spte write-protection is caused by protecting shadow page table. 1227c50d8ae3SPaolo Bonzini * 1228c50d8ae3SPaolo Bonzini * Note: write protection is difference between dirty logging and spte 1229c50d8ae3SPaolo Bonzini * protection: 1230c50d8ae3SPaolo Bonzini * - for dirty logging, the spte can be set to writable at anytime if 1231c50d8ae3SPaolo Bonzini * its dirty bitmap is properly set. 1232c50d8ae3SPaolo Bonzini * - for spte protection, the spte can be writable only after unsync-ing 1233c50d8ae3SPaolo Bonzini * shadow page. 1234c50d8ae3SPaolo Bonzini * 1235c50d8ae3SPaolo Bonzini * Return true if tlb need be flushed. 1236c50d8ae3SPaolo Bonzini */ 1237c50d8ae3SPaolo Bonzini static bool spte_write_protect(u64 *sptep, bool pt_protect) 1238c50d8ae3SPaolo Bonzini { 1239c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1240c50d8ae3SPaolo Bonzini 1241c50d8ae3SPaolo Bonzini if (!is_writable_pte(spte) && 1242706c9c55SSean Christopherson !(pt_protect && is_mmu_writable_spte(spte))) 1243c50d8ae3SPaolo Bonzini return false; 1244c50d8ae3SPaolo Bonzini 1245805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1246c50d8ae3SPaolo Bonzini 1247c50d8ae3SPaolo Bonzini if (pt_protect) 12485fc3424fSSean Christopherson spte &= ~shadow_mmu_writable_mask; 1249c50d8ae3SPaolo Bonzini spte = spte & ~PT_WRITABLE_MASK; 1250c50d8ae3SPaolo Bonzini 1251c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1252c50d8ae3SPaolo Bonzini } 1253c50d8ae3SPaolo Bonzini 12541346bbb6SDavid Matlack static bool rmap_write_protect(struct kvm_rmap_head *rmap_head, 1255c50d8ae3SPaolo Bonzini bool pt_protect) 1256c50d8ae3SPaolo Bonzini { 1257c50d8ae3SPaolo Bonzini u64 *sptep; 1258c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1259c50d8ae3SPaolo Bonzini bool flush = false; 1260c50d8ae3SPaolo Bonzini 1261c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1262c50d8ae3SPaolo Bonzini flush |= spte_write_protect(sptep, pt_protect); 1263c50d8ae3SPaolo Bonzini 1264c50d8ae3SPaolo Bonzini return flush; 1265c50d8ae3SPaolo Bonzini } 1266c50d8ae3SPaolo Bonzini 1267c50d8ae3SPaolo Bonzini static bool spte_clear_dirty(u64 *sptep) 1268c50d8ae3SPaolo Bonzini { 1269c50d8ae3SPaolo Bonzini u64 spte = *sptep; 1270c50d8ae3SPaolo Bonzini 1271805a0f83SStephen Zhang rmap_printk("spte %p %llx\n", sptep, *sptep); 1272c50d8ae3SPaolo Bonzini 1273c50d8ae3SPaolo Bonzini MMU_WARN_ON(!spte_ad_enabled(spte)); 1274c50d8ae3SPaolo Bonzini spte &= ~shadow_dirty_mask; 1275c50d8ae3SPaolo Bonzini return mmu_spte_update(sptep, spte); 1276c50d8ae3SPaolo Bonzini } 1277c50d8ae3SPaolo Bonzini 1278c50d8ae3SPaolo Bonzini static bool spte_wrprot_for_clear_dirty(u64 *sptep) 1279c50d8ae3SPaolo Bonzini { 1280c50d8ae3SPaolo Bonzini bool was_writable = test_and_clear_bit(PT_WRITABLE_SHIFT, 1281c50d8ae3SPaolo Bonzini (unsigned long *)sptep); 1282c50d8ae3SPaolo Bonzini if (was_writable && !spte_ad_enabled(*sptep)) 1283c50d8ae3SPaolo Bonzini kvm_set_pfn_dirty(spte_to_pfn(*sptep)); 1284c50d8ae3SPaolo Bonzini 1285c50d8ae3SPaolo Bonzini return was_writable; 1286c50d8ae3SPaolo Bonzini } 1287c50d8ae3SPaolo Bonzini 1288c50d8ae3SPaolo Bonzini /* 1289c50d8ae3SPaolo Bonzini * Gets the GFN ready for another round of dirty logging by clearing the 1290c50d8ae3SPaolo Bonzini * - D bit on ad-enabled SPTEs, and 1291c50d8ae3SPaolo Bonzini * - W bit on ad-disabled SPTEs. 1292c50d8ae3SPaolo Bonzini * Returns true iff any D or W bits were cleared. 1293c50d8ae3SPaolo Bonzini */ 12940a234f5dSSean Christopherson static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1295269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1296c50d8ae3SPaolo Bonzini { 1297c50d8ae3SPaolo Bonzini u64 *sptep; 1298c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1299c50d8ae3SPaolo Bonzini bool flush = false; 1300c50d8ae3SPaolo Bonzini 1301c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1302c50d8ae3SPaolo Bonzini if (spte_ad_need_write_protect(*sptep)) 1303c50d8ae3SPaolo Bonzini flush |= spte_wrprot_for_clear_dirty(sptep); 1304c50d8ae3SPaolo Bonzini else 1305c50d8ae3SPaolo Bonzini flush |= spte_clear_dirty(sptep); 1306c50d8ae3SPaolo Bonzini 1307c50d8ae3SPaolo Bonzini return flush; 1308c50d8ae3SPaolo Bonzini } 1309c50d8ae3SPaolo Bonzini 1310c50d8ae3SPaolo Bonzini /** 1311c50d8ae3SPaolo Bonzini * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages 1312c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1313c50d8ae3SPaolo Bonzini * @slot: slot to protect 1314c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1315c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should protect 1316c50d8ae3SPaolo Bonzini * 131789212919SKeqian Zhu * Used when we do not need to care about huge page mappings. 1318c50d8ae3SPaolo Bonzini */ 1319c50d8ae3SPaolo Bonzini static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, 1320c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1321c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1322c50d8ae3SPaolo Bonzini { 1323c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1324c50d8ae3SPaolo Bonzini 13251f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1326a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1327a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, true); 1328e2209710SBen Gardon 1329e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1330e2209710SBen Gardon return; 1331e2209710SBen Gardon 1332c50d8ae3SPaolo Bonzini while (mask) { 133393e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13343bae0459SSean Christopherson PG_LEVEL_4K, slot); 13351346bbb6SDavid Matlack rmap_write_protect(rmap_head, false); 1336c50d8ae3SPaolo Bonzini 1337c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1338c50d8ae3SPaolo Bonzini mask &= mask - 1; 1339c50d8ae3SPaolo Bonzini } 1340c50d8ae3SPaolo Bonzini } 1341c50d8ae3SPaolo Bonzini 1342c50d8ae3SPaolo Bonzini /** 1343c50d8ae3SPaolo Bonzini * kvm_mmu_clear_dirty_pt_masked - clear MMU D-bit for PT level pages, or write 1344c50d8ae3SPaolo Bonzini * protect the page if the D-bit isn't supported. 1345c50d8ae3SPaolo Bonzini * @kvm: kvm instance 1346c50d8ae3SPaolo Bonzini * @slot: slot to clear D-bit 1347c50d8ae3SPaolo Bonzini * @gfn_offset: start of the BITS_PER_LONG pages we care about 1348c50d8ae3SPaolo Bonzini * @mask: indicates which pages we should clear D-bit 1349c50d8ae3SPaolo Bonzini * 1350c50d8ae3SPaolo Bonzini * Used for PML to re-log the dirty GPAs after userspace querying dirty_bitmap. 1351c50d8ae3SPaolo Bonzini */ 1352a018eba5SSean Christopherson static void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1353c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1354c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1355c50d8ae3SPaolo Bonzini { 1356c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1357c50d8ae3SPaolo Bonzini 13581f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1359a6a0b05dSBen Gardon kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, 1360a6a0b05dSBen Gardon slot->base_gfn + gfn_offset, mask, false); 1361e2209710SBen Gardon 1362e2209710SBen Gardon if (!kvm_memslots_have_rmaps(kvm)) 1363e2209710SBen Gardon return; 1364e2209710SBen Gardon 1365c50d8ae3SPaolo Bonzini while (mask) { 136693e083d4SDavid Matlack rmap_head = gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask), 13673bae0459SSean Christopherson PG_LEVEL_4K, slot); 13680a234f5dSSean Christopherson __rmap_clear_dirty(kvm, rmap_head, slot); 1369c50d8ae3SPaolo Bonzini 1370c50d8ae3SPaolo Bonzini /* clear the first set bit */ 1371c50d8ae3SPaolo Bonzini mask &= mask - 1; 1372c50d8ae3SPaolo Bonzini } 1373c50d8ae3SPaolo Bonzini } 1374c50d8ae3SPaolo Bonzini 1375c50d8ae3SPaolo Bonzini /** 1376c50d8ae3SPaolo Bonzini * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected 1377c50d8ae3SPaolo Bonzini * PT level pages. 1378c50d8ae3SPaolo Bonzini * 1379c50d8ae3SPaolo Bonzini * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to 1380c50d8ae3SPaolo Bonzini * enable dirty logging for them. 1381c50d8ae3SPaolo Bonzini * 138289212919SKeqian Zhu * We need to care about huge page mappings: e.g. during dirty logging we may 138389212919SKeqian Zhu * have such mappings. 1384c50d8ae3SPaolo Bonzini */ 1385c50d8ae3SPaolo Bonzini void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 1386c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 1387c50d8ae3SPaolo Bonzini gfn_t gfn_offset, unsigned long mask) 1388c50d8ae3SPaolo Bonzini { 138989212919SKeqian Zhu /* 139089212919SKeqian Zhu * Huge pages are NOT write protected when we start dirty logging in 139189212919SKeqian Zhu * initially-all-set mode; must write protect them here so that they 139289212919SKeqian Zhu * are split to 4K on the first write. 139389212919SKeqian Zhu * 139489212919SKeqian Zhu * The gfn_offset is guaranteed to be aligned to 64, but the base_gfn 139589212919SKeqian Zhu * of memslot has no such restriction, so the range can cross two large 139689212919SKeqian Zhu * pages. 139789212919SKeqian Zhu */ 139889212919SKeqian Zhu if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { 139989212919SKeqian Zhu gfn_t start = slot->base_gfn + gfn_offset + __ffs(mask); 140089212919SKeqian Zhu gfn_t end = slot->base_gfn + gfn_offset + __fls(mask); 140189212919SKeqian Zhu 1402cb00a70bSDavid Matlack if (READ_ONCE(eager_page_split)) 1403cb00a70bSDavid Matlack kvm_mmu_try_split_huge_pages(kvm, slot, start, end, PG_LEVEL_4K); 1404cb00a70bSDavid Matlack 140589212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, start, PG_LEVEL_2M); 140689212919SKeqian Zhu 140789212919SKeqian Zhu /* Cross two large pages? */ 140889212919SKeqian Zhu if (ALIGN(start << PAGE_SHIFT, PMD_SIZE) != 140989212919SKeqian Zhu ALIGN(end << PAGE_SHIFT, PMD_SIZE)) 141089212919SKeqian Zhu kvm_mmu_slot_gfn_write_protect(kvm, slot, end, 141189212919SKeqian Zhu PG_LEVEL_2M); 141289212919SKeqian Zhu } 141389212919SKeqian Zhu 141489212919SKeqian Zhu /* Now handle 4K PTEs. */ 1415a018eba5SSean Christopherson if (kvm_x86_ops.cpu_dirty_log_size) 1416a018eba5SSean Christopherson kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); 1417c50d8ae3SPaolo Bonzini else 1418c50d8ae3SPaolo Bonzini kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); 1419c50d8ae3SPaolo Bonzini } 1420c50d8ae3SPaolo Bonzini 1421fb04a1edSPeter Xu int kvm_cpu_dirty_log_size(void) 1422fb04a1edSPeter Xu { 14236dd03800SSean Christopherson return kvm_x86_ops.cpu_dirty_log_size; 1424fb04a1edSPeter Xu } 1425fb04a1edSPeter Xu 1426c50d8ae3SPaolo Bonzini bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, 14273ad93562SKeqian Zhu struct kvm_memory_slot *slot, u64 gfn, 14283ad93562SKeqian Zhu int min_level) 1429c50d8ae3SPaolo Bonzini { 1430c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap_head; 1431c50d8ae3SPaolo Bonzini int i; 1432c50d8ae3SPaolo Bonzini bool write_protected = false; 1433c50d8ae3SPaolo Bonzini 1434e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 14353ad93562SKeqian Zhu for (i = min_level; i <= KVM_MAX_HUGEPAGE_LEVEL; ++i) { 143693e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, i, slot); 14371346bbb6SDavid Matlack write_protected |= rmap_write_protect(rmap_head, true); 1438c50d8ae3SPaolo Bonzini } 1439e2209710SBen Gardon } 1440c50d8ae3SPaolo Bonzini 14411f98f2bdSDavid Matlack if (tdp_mmu_enabled) 144246044f72SBen Gardon write_protected |= 14433ad93562SKeqian Zhu kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn, min_level); 144446044f72SBen Gardon 1445c50d8ae3SPaolo Bonzini return write_protected; 1446c50d8ae3SPaolo Bonzini } 1447c50d8ae3SPaolo Bonzini 1448cf48f9e2SDavid Matlack static bool kvm_vcpu_write_protect_gfn(struct kvm_vcpu *vcpu, u64 gfn) 1449c50d8ae3SPaolo Bonzini { 1450c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 1451c50d8ae3SPaolo Bonzini 1452c50d8ae3SPaolo Bonzini slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); 14533ad93562SKeqian Zhu return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); 1454c50d8ae3SPaolo Bonzini } 1455c50d8ae3SPaolo Bonzini 1456f8480721SSean Christopherson static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1457269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 1458c50d8ae3SPaolo Bonzini { 14599202aee8SSean Christopherson return kvm_zap_all_rmap_sptes(kvm, rmap_head); 1460c50d8ae3SPaolo Bonzini } 1461c50d8ae3SPaolo Bonzini 1462f8480721SSean Christopherson static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1463c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14643039bcc7SSean Christopherson pte_t unused) 1465c50d8ae3SPaolo Bonzini { 1466f8480721SSean Christopherson return __kvm_zap_rmap(kvm, rmap_head, slot); 1467c50d8ae3SPaolo Bonzini } 1468c50d8ae3SPaolo Bonzini 1469aed02fe3SSean Christopherson static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1470c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 14713039bcc7SSean Christopherson pte_t pte) 1472c50d8ae3SPaolo Bonzini { 1473c50d8ae3SPaolo Bonzini u64 *sptep; 1474c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 147598a26b69SVihas Mak bool need_flush = false; 1476c50d8ae3SPaolo Bonzini u64 new_spte; 1477c50d8ae3SPaolo Bonzini kvm_pfn_t new_pfn; 1478c50d8ae3SPaolo Bonzini 14793039bcc7SSean Christopherson WARN_ON(pte_huge(pte)); 14803039bcc7SSean Christopherson new_pfn = pte_pfn(pte); 1481c50d8ae3SPaolo Bonzini 1482c50d8ae3SPaolo Bonzini restart: 1483c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 1484805a0f83SStephen Zhang rmap_printk("spte %p %llx gfn %llx (%d)\n", 1485c50d8ae3SPaolo Bonzini sptep, *sptep, gfn, level); 1486c50d8ae3SPaolo Bonzini 148798a26b69SVihas Mak need_flush = true; 1488c50d8ae3SPaolo Bonzini 14893039bcc7SSean Christopherson if (pte_write(pte)) { 14909202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 1491c50d8ae3SPaolo Bonzini goto restart; 1492c50d8ae3SPaolo Bonzini } else { 1493cb3eedabSPaolo Bonzini new_spte = kvm_mmu_changed_pte_notifier_make_spte( 1494cb3eedabSPaolo Bonzini *sptep, new_pfn); 1495c50d8ae3SPaolo Bonzini 149671f51d2cSMingwei Zhang mmu_spte_clear_track_bits(kvm, sptep); 1497c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, new_spte); 1498c50d8ae3SPaolo Bonzini } 1499c50d8ae3SPaolo Bonzini } 1500c50d8ae3SPaolo Bonzini 1501c50d8ae3SPaolo Bonzini if (need_flush && kvm_available_flush_tlb_with_range()) { 15029ffe9265SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, level); 150398a26b69SVihas Mak return false; 1504c50d8ae3SPaolo Bonzini } 1505c50d8ae3SPaolo Bonzini 1506c50d8ae3SPaolo Bonzini return need_flush; 1507c50d8ae3SPaolo Bonzini } 1508c50d8ae3SPaolo Bonzini 1509c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator { 1510c50d8ae3SPaolo Bonzini /* input fields. */ 1511269e9552SHamza Mahfooz const struct kvm_memory_slot *slot; 1512c50d8ae3SPaolo Bonzini gfn_t start_gfn; 1513c50d8ae3SPaolo Bonzini gfn_t end_gfn; 1514c50d8ae3SPaolo Bonzini int start_level; 1515c50d8ae3SPaolo Bonzini int end_level; 1516c50d8ae3SPaolo Bonzini 1517c50d8ae3SPaolo Bonzini /* output fields. */ 1518c50d8ae3SPaolo Bonzini gfn_t gfn; 1519c50d8ae3SPaolo Bonzini struct kvm_rmap_head *rmap; 1520c50d8ae3SPaolo Bonzini int level; 1521c50d8ae3SPaolo Bonzini 1522c50d8ae3SPaolo Bonzini /* private field. */ 1523c50d8ae3SPaolo Bonzini struct kvm_rmap_head *end_rmap; 1524c50d8ae3SPaolo Bonzini }; 1525c50d8ae3SPaolo Bonzini 1526f3d90f90SSean Christopherson static void rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, 1527f3d90f90SSean Christopherson int level) 1528c50d8ae3SPaolo Bonzini { 1529c50d8ae3SPaolo Bonzini iterator->level = level; 1530c50d8ae3SPaolo Bonzini iterator->gfn = iterator->start_gfn; 153193e083d4SDavid Matlack iterator->rmap = gfn_to_rmap(iterator->gfn, level, iterator->slot); 153293e083d4SDavid Matlack iterator->end_rmap = gfn_to_rmap(iterator->end_gfn, level, iterator->slot); 1533c50d8ae3SPaolo Bonzini } 1534c50d8ae3SPaolo Bonzini 1535f3d90f90SSean Christopherson static void slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator, 1536f3d90f90SSean Christopherson const struct kvm_memory_slot *slot, 1537f3d90f90SSean Christopherson int start_level, int end_level, 1538f3d90f90SSean Christopherson gfn_t start_gfn, gfn_t end_gfn) 1539c50d8ae3SPaolo Bonzini { 1540c50d8ae3SPaolo Bonzini iterator->slot = slot; 1541c50d8ae3SPaolo Bonzini iterator->start_level = start_level; 1542c50d8ae3SPaolo Bonzini iterator->end_level = end_level; 1543c50d8ae3SPaolo Bonzini iterator->start_gfn = start_gfn; 1544c50d8ae3SPaolo Bonzini iterator->end_gfn = end_gfn; 1545c50d8ae3SPaolo Bonzini 1546c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->start_level); 1547c50d8ae3SPaolo Bonzini } 1548c50d8ae3SPaolo Bonzini 1549c50d8ae3SPaolo Bonzini static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) 1550c50d8ae3SPaolo Bonzini { 1551c50d8ae3SPaolo Bonzini return !!iterator->rmap; 1552c50d8ae3SPaolo Bonzini } 1553c50d8ae3SPaolo Bonzini 1554c50d8ae3SPaolo Bonzini static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) 1555c50d8ae3SPaolo Bonzini { 15566ba1e04fSVipin Sharma while (++iterator->rmap <= iterator->end_rmap) { 1557c50d8ae3SPaolo Bonzini iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level)); 15586ba1e04fSVipin Sharma 15596ba1e04fSVipin Sharma if (iterator->rmap->val) 1560c50d8ae3SPaolo Bonzini return; 1561c50d8ae3SPaolo Bonzini } 1562c50d8ae3SPaolo Bonzini 1563c50d8ae3SPaolo Bonzini if (++iterator->level > iterator->end_level) { 1564c50d8ae3SPaolo Bonzini iterator->rmap = NULL; 1565c50d8ae3SPaolo Bonzini return; 1566c50d8ae3SPaolo Bonzini } 1567c50d8ae3SPaolo Bonzini 1568c50d8ae3SPaolo Bonzini rmap_walk_init_level(iterator, iterator->level); 1569c50d8ae3SPaolo Bonzini } 1570c50d8ae3SPaolo Bonzini 1571c50d8ae3SPaolo Bonzini #define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_, \ 1572c50d8ae3SPaolo Bonzini _start_gfn, _end_gfn, _iter_) \ 1573c50d8ae3SPaolo Bonzini for (slot_rmap_walk_init(_iter_, _slot_, _start_level_, \ 1574c50d8ae3SPaolo Bonzini _end_level_, _start_gfn, _end_gfn); \ 1575c50d8ae3SPaolo Bonzini slot_rmap_walk_okay(_iter_); \ 1576c50d8ae3SPaolo Bonzini slot_rmap_walk_next(_iter_)) 1577c50d8ae3SPaolo Bonzini 15783039bcc7SSean Christopherson typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1579c1b91493SSean Christopherson struct kvm_memory_slot *slot, gfn_t gfn, 15803039bcc7SSean Christopherson int level, pte_t pte); 1581c1b91493SSean Christopherson 15823039bcc7SSean Christopherson static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, 15833039bcc7SSean Christopherson struct kvm_gfn_range *range, 1584c1b91493SSean Christopherson rmap_handler_t handler) 1585c50d8ae3SPaolo Bonzini { 1586c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 15873039bcc7SSean Christopherson bool ret = false; 1588c50d8ae3SPaolo Bonzini 15893039bcc7SSean Christopherson for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 15903039bcc7SSean Christopherson range->start, range->end - 1, &iterator) 15913039bcc7SSean Christopherson ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, 15923039bcc7SSean Christopherson iterator.level, range->pte); 1593c50d8ae3SPaolo Bonzini 1594c50d8ae3SPaolo Bonzini return ret; 1595c50d8ae3SPaolo Bonzini } 1596c50d8ae3SPaolo Bonzini 15973039bcc7SSean Christopherson bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 1598c50d8ae3SPaolo Bonzini { 1599e2209710SBen Gardon bool flush = false; 1600c50d8ae3SPaolo Bonzini 1601e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1602f8480721SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); 1603063afacdSBen Gardon 16041f98f2bdSDavid Matlack if (tdp_mmu_enabled) 1605c7785d85SHou Wenlong flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); 1606063afacdSBen Gardon 16073039bcc7SSean Christopherson return flush; 1608c50d8ae3SPaolo Bonzini } 1609c50d8ae3SPaolo Bonzini 16103039bcc7SSean Christopherson bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1611c50d8ae3SPaolo Bonzini { 1612e2209710SBen Gardon bool flush = false; 16131d8dd6b3SBen Gardon 1614e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1615aed02fe3SSean Christopherson flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmap); 16161d8dd6b3SBen Gardon 16171f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16183039bcc7SSean Christopherson flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); 16191d8dd6b3SBen Gardon 16203039bcc7SSean Christopherson return flush; 1621c50d8ae3SPaolo Bonzini } 1622c50d8ae3SPaolo Bonzini 1623aed02fe3SSean Christopherson static bool kvm_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1624c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, int level, 16253039bcc7SSean Christopherson pte_t unused) 1626c50d8ae3SPaolo Bonzini { 1627c50d8ae3SPaolo Bonzini u64 *sptep; 16283f649ab7SKees Cook struct rmap_iterator iter; 1629c50d8ae3SPaolo Bonzini int young = 0; 1630c50d8ae3SPaolo Bonzini 1631c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1632c50d8ae3SPaolo Bonzini young |= mmu_spte_age(sptep); 1633c50d8ae3SPaolo Bonzini 1634c50d8ae3SPaolo Bonzini return young; 1635c50d8ae3SPaolo Bonzini } 1636c50d8ae3SPaolo Bonzini 1637aed02fe3SSean Christopherson static bool kvm_test_age_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, 1638c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, gfn_t gfn, 16393039bcc7SSean Christopherson int level, pte_t unused) 1640c50d8ae3SPaolo Bonzini { 1641c50d8ae3SPaolo Bonzini u64 *sptep; 1642c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1643c50d8ae3SPaolo Bonzini 1644c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) 1645c50d8ae3SPaolo Bonzini if (is_accessed_spte(*sptep)) 164698a26b69SVihas Mak return true; 164798a26b69SVihas Mak return false; 1648c50d8ae3SPaolo Bonzini } 1649c50d8ae3SPaolo Bonzini 1650c50d8ae3SPaolo Bonzini #define RMAP_RECYCLE_THRESHOLD 1000 1651c50d8ae3SPaolo Bonzini 16522ff9039aSDavid Matlack static void __rmap_add(struct kvm *kvm, 16532ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache, 16542ff9039aSDavid Matlack const struct kvm_memory_slot *slot, 165572ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 1656c50d8ae3SPaolo Bonzini { 1657c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 165868be1306SDavid Matlack struct kvm_rmap_head *rmap_head; 165968be1306SDavid Matlack int rmap_count; 1660c50d8ae3SPaolo Bonzini 166157354682SSean Christopherson sp = sptep_to_sp(spte); 166279e48cecSSean Christopherson kvm_mmu_page_set_translation(sp, spte_index(spte), gfn, access); 166381cb4657SDavid Matlack kvm_update_page_stats(kvm, sp->role.level, 1); 166481cb4657SDavid Matlack 166593e083d4SDavid Matlack rmap_head = gfn_to_rmap(gfn, sp->role.level, slot); 16662ff9039aSDavid Matlack rmap_count = pte_list_add(cache, spte, rmap_head); 1667c50d8ae3SPaolo Bonzini 1668604f5332SMiaohe Lin if (rmap_count > kvm->stat.max_mmu_rmap_size) 1669604f5332SMiaohe Lin kvm->stat.max_mmu_rmap_size = rmap_count; 167068be1306SDavid Matlack if (rmap_count > RMAP_RECYCLE_THRESHOLD) { 16719202aee8SSean Christopherson kvm_zap_all_rmap_sptes(kvm, rmap_head); 16721b2dc736SHou Wenlong kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level); 167368be1306SDavid Matlack } 1674c50d8ae3SPaolo Bonzini } 1675c50d8ae3SPaolo Bonzini 16762ff9039aSDavid Matlack static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot, 167772ae5822SSean Christopherson u64 *spte, gfn_t gfn, unsigned int access) 16782ff9039aSDavid Matlack { 16792ff9039aSDavid Matlack struct kvm_mmu_memory_cache *cache = &vcpu->arch.mmu_pte_list_desc_cache; 16802ff9039aSDavid Matlack 16816a97575dSDavid Matlack __rmap_add(vcpu->kvm, cache, slot, spte, gfn, access); 16822ff9039aSDavid Matlack } 16832ff9039aSDavid Matlack 16843039bcc7SSean Christopherson bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1685c50d8ae3SPaolo Bonzini { 1686e2209710SBen Gardon bool young = false; 1687f8e14497SBen Gardon 1688e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1689aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_age_rmap); 16903039bcc7SSean Christopherson 16911f98f2bdSDavid Matlack if (tdp_mmu_enabled) 16923039bcc7SSean Christopherson young |= kvm_tdp_mmu_age_gfn_range(kvm, range); 1693f8e14497SBen Gardon 1694f8e14497SBen Gardon return young; 1695c50d8ae3SPaolo Bonzini } 1696c50d8ae3SPaolo Bonzini 16973039bcc7SSean Christopherson bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 1698c50d8ae3SPaolo Bonzini { 1699e2209710SBen Gardon bool young = false; 1700f8e14497SBen Gardon 1701e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) 1702aed02fe3SSean Christopherson young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmap); 17033039bcc7SSean Christopherson 17041f98f2bdSDavid Matlack if (tdp_mmu_enabled) 17053039bcc7SSean Christopherson young |= kvm_tdp_mmu_test_age_gfn(kvm, range); 1706f8e14497SBen Gardon 1707f8e14497SBen Gardon return young; 1708c50d8ae3SPaolo Bonzini } 1709c50d8ae3SPaolo Bonzini 1710c50d8ae3SPaolo Bonzini #ifdef MMU_DEBUG 1711c50d8ae3SPaolo Bonzini static int is_empty_shadow_page(u64 *spt) 1712c50d8ae3SPaolo Bonzini { 1713c50d8ae3SPaolo Bonzini u64 *pos; 1714c50d8ae3SPaolo Bonzini u64 *end; 1715c50d8ae3SPaolo Bonzini 17163adbdf81SMiaohe Lin for (pos = spt, end = pos + SPTE_ENT_PER_PAGE; pos != end; pos++) 1717c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*pos)) { 1718c50d8ae3SPaolo Bonzini printk(KERN_ERR "%s: %p %llx\n", __func__, 1719c50d8ae3SPaolo Bonzini pos, *pos); 1720c50d8ae3SPaolo Bonzini return 0; 1721c50d8ae3SPaolo Bonzini } 1722c50d8ae3SPaolo Bonzini return 1; 1723c50d8ae3SPaolo Bonzini } 1724c50d8ae3SPaolo Bonzini #endif 1725c50d8ae3SPaolo Bonzini 1726c50d8ae3SPaolo Bonzini /* 1727c50d8ae3SPaolo Bonzini * This value is the sum of all of the kvm instances's 1728c50d8ae3SPaolo Bonzini * kvm->arch.n_used_mmu_pages values. We need a global, 1729c50d8ae3SPaolo Bonzini * aggregate version in order to make the slab shrinker 1730c50d8ae3SPaolo Bonzini * faster 1731c50d8ae3SPaolo Bonzini */ 1732d5aaad6fSSean Christopherson static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) 1733c50d8ae3SPaolo Bonzini { 1734c50d8ae3SPaolo Bonzini kvm->arch.n_used_mmu_pages += nr; 1735c50d8ae3SPaolo Bonzini percpu_counter_add(&kvm_total_used_mmu_pages, nr); 1736c50d8ae3SPaolo Bonzini } 1737c50d8ae3SPaolo Bonzini 173843a063caSYosry Ahmed static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 173943a063caSYosry Ahmed { 174043a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, +1); 174143a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, +1); 174243a063caSYosry Ahmed } 174343a063caSYosry Ahmed 174443a063caSYosry Ahmed static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) 174543a063caSYosry Ahmed { 174643a063caSYosry Ahmed kvm_mod_used_mmu_pages(kvm, -1); 174743a063caSYosry Ahmed kvm_account_pgtable_pages((void *)sp->spt, -1); 174843a063caSYosry Ahmed } 174943a063caSYosry Ahmed 175087654643SDavid Matlack static void kvm_mmu_free_shadow_page(struct kvm_mmu_page *sp) 1751c50d8ae3SPaolo Bonzini { 1752c50d8ae3SPaolo Bonzini MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); 1753c50d8ae3SPaolo Bonzini hlist_del(&sp->hash_link); 1754c50d8ae3SPaolo Bonzini list_del(&sp->link); 1755c50d8ae3SPaolo Bonzini free_page((unsigned long)sp->spt); 1756c50d8ae3SPaolo Bonzini if (!sp->role.direct) 17576a97575dSDavid Matlack free_page((unsigned long)sp->shadowed_translation); 1758c50d8ae3SPaolo Bonzini kmem_cache_free(mmu_page_header_cache, sp); 1759c50d8ae3SPaolo Bonzini } 1760c50d8ae3SPaolo Bonzini 1761c50d8ae3SPaolo Bonzini static unsigned kvm_page_table_hashfn(gfn_t gfn) 1762c50d8ae3SPaolo Bonzini { 1763c50d8ae3SPaolo Bonzini return hash_64(gfn, KVM_MMU_HASH_SHIFT); 1764c50d8ae3SPaolo Bonzini } 1765c50d8ae3SPaolo Bonzini 17662ff9039aSDavid Matlack static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache, 1767c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *parent_pte) 1768c50d8ae3SPaolo Bonzini { 1769c50d8ae3SPaolo Bonzini if (!parent_pte) 1770c50d8ae3SPaolo Bonzini return; 1771c50d8ae3SPaolo Bonzini 17722ff9039aSDavid Matlack pte_list_add(cache, parent_pte, &sp->parent_ptes); 1773c50d8ae3SPaolo Bonzini } 1774c50d8ae3SPaolo Bonzini 1775c50d8ae3SPaolo Bonzini static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, 1776c50d8ae3SPaolo Bonzini u64 *parent_pte) 1777c50d8ae3SPaolo Bonzini { 17783c2e1037SSean Christopherson pte_list_remove(parent_pte, &sp->parent_ptes); 1779c50d8ae3SPaolo Bonzini } 1780c50d8ae3SPaolo Bonzini 1781c50d8ae3SPaolo Bonzini static void drop_parent_pte(struct kvm_mmu_page *sp, 1782c50d8ae3SPaolo Bonzini u64 *parent_pte) 1783c50d8ae3SPaolo Bonzini { 1784c50d8ae3SPaolo Bonzini mmu_page_remove_parent_pte(sp, parent_pte); 1785c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(parent_pte); 1786c50d8ae3SPaolo Bonzini } 1787c50d8ae3SPaolo Bonzini 1788c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte); 1789c50d8ae3SPaolo Bonzini static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) 1790c50d8ae3SPaolo Bonzini { 1791c50d8ae3SPaolo Bonzini u64 *sptep; 1792c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 1793c50d8ae3SPaolo Bonzini 1794c50d8ae3SPaolo Bonzini for_each_rmap_spte(&sp->parent_ptes, &iter, sptep) { 1795c50d8ae3SPaolo Bonzini mark_unsync(sptep); 1796c50d8ae3SPaolo Bonzini } 1797c50d8ae3SPaolo Bonzini } 1798c50d8ae3SPaolo Bonzini 1799c50d8ae3SPaolo Bonzini static void mark_unsync(u64 *spte) 1800c50d8ae3SPaolo Bonzini { 1801c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1802c50d8ae3SPaolo Bonzini 180357354682SSean Christopherson sp = sptep_to_sp(spte); 180479e48cecSSean Christopherson if (__test_and_set_bit(spte_index(spte), sp->unsync_child_bitmap)) 1805c50d8ae3SPaolo Bonzini return; 1806c50d8ae3SPaolo Bonzini if (sp->unsync_children++) 1807c50d8ae3SPaolo Bonzini return; 1808c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 1809c50d8ae3SPaolo Bonzini } 1810c50d8ae3SPaolo Bonzini 1811c50d8ae3SPaolo Bonzini #define KVM_PAGE_ARRAY_NR 16 1812c50d8ae3SPaolo Bonzini 1813c50d8ae3SPaolo Bonzini struct kvm_mmu_pages { 1814c50d8ae3SPaolo Bonzini struct mmu_page_and_offset { 1815c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 1816c50d8ae3SPaolo Bonzini unsigned int idx; 1817c50d8ae3SPaolo Bonzini } page[KVM_PAGE_ARRAY_NR]; 1818c50d8ae3SPaolo Bonzini unsigned int nr; 1819c50d8ae3SPaolo Bonzini }; 1820c50d8ae3SPaolo Bonzini 1821c50d8ae3SPaolo Bonzini static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, 1822c50d8ae3SPaolo Bonzini int idx) 1823c50d8ae3SPaolo Bonzini { 1824c50d8ae3SPaolo Bonzini int i; 1825c50d8ae3SPaolo Bonzini 1826c50d8ae3SPaolo Bonzini if (sp->unsync) 1827c50d8ae3SPaolo Bonzini for (i=0; i < pvec->nr; i++) 1828c50d8ae3SPaolo Bonzini if (pvec->page[i].sp == sp) 1829c50d8ae3SPaolo Bonzini return 0; 1830c50d8ae3SPaolo Bonzini 1831c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].sp = sp; 1832c50d8ae3SPaolo Bonzini pvec->page[pvec->nr].idx = idx; 1833c50d8ae3SPaolo Bonzini pvec->nr++; 1834c50d8ae3SPaolo Bonzini return (pvec->nr == KVM_PAGE_ARRAY_NR); 1835c50d8ae3SPaolo Bonzini } 1836c50d8ae3SPaolo Bonzini 1837c50d8ae3SPaolo Bonzini static inline void clear_unsync_child_bit(struct kvm_mmu_page *sp, int idx) 1838c50d8ae3SPaolo Bonzini { 1839c50d8ae3SPaolo Bonzini --sp->unsync_children; 1840c50d8ae3SPaolo Bonzini WARN_ON((int)sp->unsync_children < 0); 1841c50d8ae3SPaolo Bonzini __clear_bit(idx, sp->unsync_child_bitmap); 1842c50d8ae3SPaolo Bonzini } 1843c50d8ae3SPaolo Bonzini 1844c50d8ae3SPaolo Bonzini static int __mmu_unsync_walk(struct kvm_mmu_page *sp, 1845c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1846c50d8ae3SPaolo Bonzini { 1847c50d8ae3SPaolo Bonzini int i, ret, nr_unsync_leaf = 0; 1848c50d8ae3SPaolo Bonzini 1849c50d8ae3SPaolo Bonzini for_each_set_bit(i, sp->unsync_child_bitmap, 512) { 1850c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 1851c50d8ae3SPaolo Bonzini u64 ent = sp->spt[i]; 1852c50d8ae3SPaolo Bonzini 1853c50d8ae3SPaolo Bonzini if (!is_shadow_present_pte(ent) || is_large_pte(ent)) { 1854c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1855c50d8ae3SPaolo Bonzini continue; 1856c50d8ae3SPaolo Bonzini } 1857c50d8ae3SPaolo Bonzini 18585e3edd7eSSean Christopherson child = spte_to_child_sp(ent); 1859c50d8ae3SPaolo Bonzini 1860c50d8ae3SPaolo Bonzini if (child->unsync_children) { 1861c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1862c50d8ae3SPaolo Bonzini return -ENOSPC; 1863c50d8ae3SPaolo Bonzini 1864c50d8ae3SPaolo Bonzini ret = __mmu_unsync_walk(child, pvec); 1865c50d8ae3SPaolo Bonzini if (!ret) { 1866c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1867c50d8ae3SPaolo Bonzini continue; 1868c50d8ae3SPaolo Bonzini } else if (ret > 0) { 1869c50d8ae3SPaolo Bonzini nr_unsync_leaf += ret; 1870c50d8ae3SPaolo Bonzini } else 1871c50d8ae3SPaolo Bonzini return ret; 1872c50d8ae3SPaolo Bonzini } else if (child->unsync) { 1873c50d8ae3SPaolo Bonzini nr_unsync_leaf++; 1874c50d8ae3SPaolo Bonzini if (mmu_pages_add(pvec, child, i)) 1875c50d8ae3SPaolo Bonzini return -ENOSPC; 1876c50d8ae3SPaolo Bonzini } else 1877c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, i); 1878c50d8ae3SPaolo Bonzini } 1879c50d8ae3SPaolo Bonzini 1880c50d8ae3SPaolo Bonzini return nr_unsync_leaf; 1881c50d8ae3SPaolo Bonzini } 1882c50d8ae3SPaolo Bonzini 1883c50d8ae3SPaolo Bonzini #define INVALID_INDEX (-1) 1884c50d8ae3SPaolo Bonzini 1885c50d8ae3SPaolo Bonzini static int mmu_unsync_walk(struct kvm_mmu_page *sp, 1886c50d8ae3SPaolo Bonzini struct kvm_mmu_pages *pvec) 1887c50d8ae3SPaolo Bonzini { 1888c50d8ae3SPaolo Bonzini pvec->nr = 0; 1889c50d8ae3SPaolo Bonzini if (!sp->unsync_children) 1890c50d8ae3SPaolo Bonzini return 0; 1891c50d8ae3SPaolo Bonzini 1892c50d8ae3SPaolo Bonzini mmu_pages_add(pvec, sp, INVALID_INDEX); 1893c50d8ae3SPaolo Bonzini return __mmu_unsync_walk(sp, pvec); 1894c50d8ae3SPaolo Bonzini } 1895c50d8ae3SPaolo Bonzini 1896c50d8ae3SPaolo Bonzini static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 1897c50d8ae3SPaolo Bonzini { 1898c50d8ae3SPaolo Bonzini WARN_ON(!sp->unsync); 1899c50d8ae3SPaolo Bonzini trace_kvm_mmu_sync_page(sp); 1900c50d8ae3SPaolo Bonzini sp->unsync = 0; 1901c50d8ae3SPaolo Bonzini --kvm->stat.mmu_unsync; 1902c50d8ae3SPaolo Bonzini } 1903c50d8ae3SPaolo Bonzini 1904c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 1905c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1906c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 1907c50d8ae3SPaolo Bonzini struct list_head *invalid_list); 1908c50d8ae3SPaolo Bonzini 1909767d8d8dSLai Jiangshan static bool sp_has_gptes(struct kvm_mmu_page *sp) 1910767d8d8dSLai Jiangshan { 1911767d8d8dSLai Jiangshan if (sp->role.direct) 1912767d8d8dSLai Jiangshan return false; 1913767d8d8dSLai Jiangshan 191484e5ffd0SLai Jiangshan if (sp->role.passthrough) 191584e5ffd0SLai Jiangshan return false; 191684e5ffd0SLai Jiangshan 1917767d8d8dSLai Jiangshan return true; 1918767d8d8dSLai Jiangshan } 1919767d8d8dSLai Jiangshan 1920ac101b7cSSean Christopherson #define for_each_valid_sp(_kvm, _sp, _list) \ 1921ac101b7cSSean Christopherson hlist_for_each_entry(_sp, _list, hash_link) \ 1922c50d8ae3SPaolo Bonzini if (is_obsolete_sp((_kvm), (_sp))) { \ 1923c50d8ae3SPaolo Bonzini } else 1924c50d8ae3SPaolo Bonzini 1925767d8d8dSLai Jiangshan #define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn) \ 1926ac101b7cSSean Christopherson for_each_valid_sp(_kvm, _sp, \ 1927ac101b7cSSean Christopherson &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ 1928767d8d8dSLai Jiangshan if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else 1929c50d8ae3SPaolo Bonzini 193090e44470SLai Jiangshan static bool kvm_sync_page_check(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 193190e44470SLai Jiangshan { 193290e44470SLai Jiangshan union kvm_mmu_page_role root_role = vcpu->arch.mmu->root_role; 193390e44470SLai Jiangshan 193490e44470SLai Jiangshan /* 193590e44470SLai Jiangshan * Ignore various flags when verifying that it's safe to sync a shadow 193690e44470SLai Jiangshan * page using the current MMU context. 193790e44470SLai Jiangshan * 193890e44470SLai Jiangshan * - level: not part of the overall MMU role and will never match as the MMU's 193990e44470SLai Jiangshan * level tracks the root level 194090e44470SLai Jiangshan * - access: updated based on the new guest PTE 194190e44470SLai Jiangshan * - quadrant: not part of the overall MMU role (similar to level) 194290e44470SLai Jiangshan */ 194390e44470SLai Jiangshan const union kvm_mmu_page_role sync_role_ign = { 194490e44470SLai Jiangshan .level = 0xf, 194590e44470SLai Jiangshan .access = 0x7, 194690e44470SLai Jiangshan .quadrant = 0x3, 194790e44470SLai Jiangshan .passthrough = 0x1, 194890e44470SLai Jiangshan }; 194990e44470SLai Jiangshan 195090e44470SLai Jiangshan /* 195190e44470SLai Jiangshan * Direct pages can never be unsync, and KVM should never attempt to 195290e44470SLai Jiangshan * sync a shadow page for a different MMU context, e.g. if the role 195390e44470SLai Jiangshan * differs then the memslot lookup (SMM vs. non-SMM) will be bogus, the 195490e44470SLai Jiangshan * reserved bits checks will be wrong, etc... 195590e44470SLai Jiangshan */ 1956c3c6c9fcSLai Jiangshan if (WARN_ON_ONCE(sp->role.direct || !vcpu->arch.mmu->sync_spte || 195790e44470SLai Jiangshan (sp->role.word ^ root_role.word) & ~sync_role_ign.word)) 195890e44470SLai Jiangshan return false; 195990e44470SLai Jiangshan 196090e44470SLai Jiangshan return true; 196190e44470SLai Jiangshan } 196290e44470SLai Jiangshan 196319ace7d6SLai Jiangshan static int kvm_sync_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int i) 196419ace7d6SLai Jiangshan { 196519ace7d6SLai Jiangshan if (!sp->spt[i]) 196619ace7d6SLai Jiangshan return 0; 196719ace7d6SLai Jiangshan 196819ace7d6SLai Jiangshan return vcpu->arch.mmu->sync_spte(vcpu, sp, i); 196919ace7d6SLai Jiangshan } 197019ace7d6SLai Jiangshan 197190e44470SLai Jiangshan static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 197290e44470SLai Jiangshan { 1973c3c6c9fcSLai Jiangshan int flush = 0; 1974c3c6c9fcSLai Jiangshan int i; 1975c3c6c9fcSLai Jiangshan 197690e44470SLai Jiangshan if (!kvm_sync_page_check(vcpu, sp)) 197790e44470SLai Jiangshan return -1; 197890e44470SLai Jiangshan 1979c3c6c9fcSLai Jiangshan for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { 198019ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, i); 1981c3c6c9fcSLai Jiangshan 1982c3c6c9fcSLai Jiangshan if (ret < -1) 1983c3c6c9fcSLai Jiangshan return -1; 1984c3c6c9fcSLai Jiangshan flush |= ret; 1985c3c6c9fcSLai Jiangshan } 1986c3c6c9fcSLai Jiangshan 1987c3c6c9fcSLai Jiangshan /* 1988c3c6c9fcSLai Jiangshan * Note, any flush is purely for KVM's correctness, e.g. when dropping 1989c3c6c9fcSLai Jiangshan * an existing SPTE or clearing W/A/D bits to ensure an mmu_notifier 1990c3c6c9fcSLai Jiangshan * unmap or dirty logging event doesn't fail to flush. The guest is 1991c3c6c9fcSLai Jiangshan * responsible for flushing the TLB to ensure any changes in protection 1992c3c6c9fcSLai Jiangshan * bits are recognized, i.e. until the guest flushes or page faults on 1993c3c6c9fcSLai Jiangshan * a relevant address, KVM is architecturally allowed to let vCPUs use 1994c3c6c9fcSLai Jiangshan * cached translations with the old protection bits. 1995c3c6c9fcSLai Jiangshan */ 1996c3c6c9fcSLai Jiangshan return flush; 199790e44470SLai Jiangshan } 199890e44470SLai Jiangshan 19998d5678a7SHou Wenlong static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 2000c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2001c50d8ae3SPaolo Bonzini { 200290e44470SLai Jiangshan int ret = __kvm_sync_page(vcpu, sp); 2003c3e5e415SLai Jiangshan 20048d5678a7SHou Wenlong if (ret < 0) 2005c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); 20068d5678a7SHou Wenlong return ret; 2007c50d8ae3SPaolo Bonzini } 2008c50d8ae3SPaolo Bonzini 2009c50d8ae3SPaolo Bonzini static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, 2010c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2011c50d8ae3SPaolo Bonzini bool remote_flush) 2012c50d8ae3SPaolo Bonzini { 2013c50d8ae3SPaolo Bonzini if (!remote_flush && list_empty(invalid_list)) 2014c50d8ae3SPaolo Bonzini return false; 2015c50d8ae3SPaolo Bonzini 2016c50d8ae3SPaolo Bonzini if (!list_empty(invalid_list)) 2017c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, invalid_list); 2018c50d8ae3SPaolo Bonzini else 2019c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2020c50d8ae3SPaolo Bonzini return true; 2021c50d8ae3SPaolo Bonzini } 2022c50d8ae3SPaolo Bonzini 2023c50d8ae3SPaolo Bonzini static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) 2024c50d8ae3SPaolo Bonzini { 2025a955cad8SSean Christopherson if (sp->role.invalid) 2026a955cad8SSean Christopherson return true; 2027a955cad8SSean Christopherson 2028fa3e4203SMiaohe Lin /* TDP MMU pages do not use the MMU generation. */ 2029de0322f5SSean Christopherson return !is_tdp_mmu_page(sp) && 2030c50d8ae3SPaolo Bonzini unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); 2031c50d8ae3SPaolo Bonzini } 2032c50d8ae3SPaolo Bonzini 2033c50d8ae3SPaolo Bonzini struct mmu_page_path { 2034c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; 2035c50d8ae3SPaolo Bonzini unsigned int idx[PT64_ROOT_MAX_LEVEL]; 2036c50d8ae3SPaolo Bonzini }; 2037c50d8ae3SPaolo Bonzini 2038c50d8ae3SPaolo Bonzini #define for_each_sp(pvec, sp, parents, i) \ 2039c50d8ae3SPaolo Bonzini for (i = mmu_pages_first(&pvec, &parents); \ 2040c50d8ae3SPaolo Bonzini i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ 2041c50d8ae3SPaolo Bonzini i = mmu_pages_next(&pvec, &parents, i)) 2042c50d8ae3SPaolo Bonzini 2043c50d8ae3SPaolo Bonzini static int mmu_pages_next(struct kvm_mmu_pages *pvec, 2044c50d8ae3SPaolo Bonzini struct mmu_page_path *parents, 2045c50d8ae3SPaolo Bonzini int i) 2046c50d8ae3SPaolo Bonzini { 2047c50d8ae3SPaolo Bonzini int n; 2048c50d8ae3SPaolo Bonzini 2049c50d8ae3SPaolo Bonzini for (n = i+1; n < pvec->nr; n++) { 2050c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp = pvec->page[n].sp; 2051c50d8ae3SPaolo Bonzini unsigned idx = pvec->page[n].idx; 2052c50d8ae3SPaolo Bonzini int level = sp->role.level; 2053c50d8ae3SPaolo Bonzini 2054c50d8ae3SPaolo Bonzini parents->idx[level-1] = idx; 20553bae0459SSean Christopherson if (level == PG_LEVEL_4K) 2056c50d8ae3SPaolo Bonzini break; 2057c50d8ae3SPaolo Bonzini 2058c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2059c50d8ae3SPaolo Bonzini } 2060c50d8ae3SPaolo Bonzini 2061c50d8ae3SPaolo Bonzini return n; 2062c50d8ae3SPaolo Bonzini } 2063c50d8ae3SPaolo Bonzini 2064c50d8ae3SPaolo Bonzini static int mmu_pages_first(struct kvm_mmu_pages *pvec, 2065c50d8ae3SPaolo Bonzini struct mmu_page_path *parents) 2066c50d8ae3SPaolo Bonzini { 2067c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2068c50d8ae3SPaolo Bonzini int level; 2069c50d8ae3SPaolo Bonzini 2070c50d8ae3SPaolo Bonzini if (pvec->nr == 0) 2071c50d8ae3SPaolo Bonzini return 0; 2072c50d8ae3SPaolo Bonzini 2073c50d8ae3SPaolo Bonzini WARN_ON(pvec->page[0].idx != INVALID_INDEX); 2074c50d8ae3SPaolo Bonzini 2075c50d8ae3SPaolo Bonzini sp = pvec->page[0].sp; 2076c50d8ae3SPaolo Bonzini level = sp->role.level; 20773bae0459SSean Christopherson WARN_ON(level == PG_LEVEL_4K); 2078c50d8ae3SPaolo Bonzini 2079c50d8ae3SPaolo Bonzini parents->parent[level-2] = sp; 2080c50d8ae3SPaolo Bonzini 2081c50d8ae3SPaolo Bonzini /* Also set up a sentinel. Further entries in pvec are all 2082c50d8ae3SPaolo Bonzini * children of sp, so this element is never overwritten. 2083c50d8ae3SPaolo Bonzini */ 2084c50d8ae3SPaolo Bonzini parents->parent[level-1] = NULL; 2085c50d8ae3SPaolo Bonzini return mmu_pages_next(pvec, parents, 0); 2086c50d8ae3SPaolo Bonzini } 2087c50d8ae3SPaolo Bonzini 2088c50d8ae3SPaolo Bonzini static void mmu_pages_clear_parents(struct mmu_page_path *parents) 2089c50d8ae3SPaolo Bonzini { 2090c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2091c50d8ae3SPaolo Bonzini unsigned int level = 0; 2092c50d8ae3SPaolo Bonzini 2093c50d8ae3SPaolo Bonzini do { 2094c50d8ae3SPaolo Bonzini unsigned int idx = parents->idx[level]; 2095c50d8ae3SPaolo Bonzini sp = parents->parent[level]; 2096c50d8ae3SPaolo Bonzini if (!sp) 2097c50d8ae3SPaolo Bonzini return; 2098c50d8ae3SPaolo Bonzini 2099c50d8ae3SPaolo Bonzini WARN_ON(idx == INVALID_INDEX); 2100c50d8ae3SPaolo Bonzini clear_unsync_child_bit(sp, idx); 2101c50d8ae3SPaolo Bonzini level++; 2102c50d8ae3SPaolo Bonzini } while (!sp->unsync_children); 2103c50d8ae3SPaolo Bonzini } 2104c50d8ae3SPaolo Bonzini 210565855ed8SLai Jiangshan static int mmu_sync_children(struct kvm_vcpu *vcpu, 210665855ed8SLai Jiangshan struct kvm_mmu_page *parent, bool can_yield) 2107c50d8ae3SPaolo Bonzini { 2108c50d8ae3SPaolo Bonzini int i; 2109c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2110c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2111c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2112c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2113c50d8ae3SPaolo Bonzini bool flush = false; 2114c50d8ae3SPaolo Bonzini 2115c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2116c50d8ae3SPaolo Bonzini bool protected = false; 2117c50d8ae3SPaolo Bonzini 2118c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) 2119cf48f9e2SDavid Matlack protected |= kvm_vcpu_write_protect_gfn(vcpu, sp->gfn); 2120c50d8ae3SPaolo Bonzini 2121c50d8ae3SPaolo Bonzini if (protected) { 21225591c069SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true); 2123c50d8ae3SPaolo Bonzini flush = false; 2124c50d8ae3SPaolo Bonzini } 2125c50d8ae3SPaolo Bonzini 2126c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2127479a1efcSSean Christopherson kvm_unlink_unsync_page(vcpu->kvm, sp); 21288d5678a7SHou Wenlong flush |= kvm_sync_page(vcpu, sp, &invalid_list) > 0; 2129c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2130c50d8ae3SPaolo Bonzini } 2131531810caSBen Gardon if (need_resched() || rwlock_needbreak(&vcpu->kvm->mmu_lock)) { 2132c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 213365855ed8SLai Jiangshan if (!can_yield) { 213465855ed8SLai Jiangshan kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 213565855ed8SLai Jiangshan return -EINTR; 213665855ed8SLai Jiangshan } 213765855ed8SLai Jiangshan 2138531810caSBen Gardon cond_resched_rwlock_write(&vcpu->kvm->mmu_lock); 2139c50d8ae3SPaolo Bonzini flush = false; 2140c50d8ae3SPaolo Bonzini } 2141c50d8ae3SPaolo Bonzini } 2142c50d8ae3SPaolo Bonzini 2143c3e5e415SLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 214465855ed8SLai Jiangshan return 0; 2145c50d8ae3SPaolo Bonzini } 2146c50d8ae3SPaolo Bonzini 2147c50d8ae3SPaolo Bonzini static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) 2148c50d8ae3SPaolo Bonzini { 2149c50d8ae3SPaolo Bonzini atomic_set(&sp->write_flooding_count, 0); 2150c50d8ae3SPaolo Bonzini } 2151c50d8ae3SPaolo Bonzini 2152c50d8ae3SPaolo Bonzini static void clear_sp_write_flooding_count(u64 *spte) 2153c50d8ae3SPaolo Bonzini { 215457354682SSean Christopherson __clear_sp_write_flooding_count(sptep_to_sp(spte)); 2155c50d8ae3SPaolo Bonzini } 2156c50d8ae3SPaolo Bonzini 2157cbd858b1SDavid Matlack /* 2158cbd858b1SDavid Matlack * The vCPU is required when finding indirect shadow pages; the shadow 2159cbd858b1SDavid Matlack * page may already exist and syncing it needs the vCPU pointer in 2160cbd858b1SDavid Matlack * order to read guest page tables. Direct shadow pages are never 2161cbd858b1SDavid Matlack * unsync, thus @vcpu can be NULL if @role.direct is true. 2162cbd858b1SDavid Matlack */ 21633cc736b3SDavid Matlack static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm, 21643cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 216594c81364SDavid Matlack gfn_t gfn, 216694c81364SDavid Matlack struct hlist_head *sp_list, 21672e65e842SDavid Matlack union kvm_mmu_page_role role) 2168c50d8ae3SPaolo Bonzini { 2169c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 21708d5678a7SHou Wenlong int ret; 2171c50d8ae3SPaolo Bonzini int collisions = 0; 2172c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2173c50d8ae3SPaolo Bonzini 21743cc736b3SDavid Matlack for_each_valid_sp(kvm, sp, sp_list) { 2175c50d8ae3SPaolo Bonzini if (sp->gfn != gfn) { 2176c50d8ae3SPaolo Bonzini collisions++; 2177c50d8ae3SPaolo Bonzini continue; 2178c50d8ae3SPaolo Bonzini } 2179c50d8ae3SPaolo Bonzini 2180ddc16abbSSean Christopherson if (sp->role.word != role.word) { 2181ddc16abbSSean Christopherson /* 2182ddc16abbSSean Christopherson * If the guest is creating an upper-level page, zap 2183ddc16abbSSean Christopherson * unsync pages for the same gfn. While it's possible 2184ddc16abbSSean Christopherson * the guest is using recursive page tables, in all 2185ddc16abbSSean Christopherson * likelihood the guest has stopped using the unsync 2186ddc16abbSSean Christopherson * page and is installing a completely unrelated page. 2187ddc16abbSSean Christopherson * Unsync pages must not be left as is, because the new 2188ddc16abbSSean Christopherson * upper-level page will be write-protected. 2189ddc16abbSSean Christopherson */ 21902e65e842SDavid Matlack if (role.level > PG_LEVEL_4K && sp->unsync) 21913cc736b3SDavid Matlack kvm_mmu_prepare_zap_page(kvm, sp, 2192ddc16abbSSean Christopherson &invalid_list); 2193c50d8ae3SPaolo Bonzini continue; 2194ddc16abbSSean Christopherson } 2195c50d8ae3SPaolo Bonzini 2196bb924ca6SDavid Matlack /* unsync and write-flooding only apply to indirect SPs. */ 2197bb924ca6SDavid Matlack if (sp->role.direct) 219894c81364SDavid Matlack goto out; 2199fb58a9c3SSean Christopherson 2200c50d8ae3SPaolo Bonzini if (sp->unsync) { 2201cbd858b1SDavid Matlack if (KVM_BUG_ON(!vcpu, kvm)) 2202cbd858b1SDavid Matlack break; 2203cbd858b1SDavid Matlack 220407dc4f35SSean Christopherson /* 2205479a1efcSSean Christopherson * The page is good, but is stale. kvm_sync_page does 220607dc4f35SSean Christopherson * get the latest guest state, but (unlike mmu_unsync_children) 220707dc4f35SSean Christopherson * it doesn't write-protect the page or mark it synchronized! 220807dc4f35SSean Christopherson * This way the validity of the mapping is ensured, but the 220907dc4f35SSean Christopherson * overhead of write protection is not incurred until the 221007dc4f35SSean Christopherson * guest invalidates the TLB mapping. This allows multiple 221107dc4f35SSean Christopherson * SPs for a single gfn to be unsync. 221207dc4f35SSean Christopherson * 221307dc4f35SSean Christopherson * If the sync fails, the page is zapped. If so, break 221407dc4f35SSean Christopherson * in order to rebuild it. 2215c50d8ae3SPaolo Bonzini */ 22168d5678a7SHou Wenlong ret = kvm_sync_page(vcpu, sp, &invalid_list); 22178d5678a7SHou Wenlong if (ret < 0) 2218c50d8ae3SPaolo Bonzini break; 2219c50d8ae3SPaolo Bonzini 2220c50d8ae3SPaolo Bonzini WARN_ON(!list_empty(&invalid_list)); 22218d5678a7SHou Wenlong if (ret > 0) 22223cc736b3SDavid Matlack kvm_flush_remote_tlbs(kvm); 2223c50d8ae3SPaolo Bonzini } 2224c50d8ae3SPaolo Bonzini 2225c50d8ae3SPaolo Bonzini __clear_sp_write_flooding_count(sp); 2226fb58a9c3SSean Christopherson 2227c50d8ae3SPaolo Bonzini goto out; 2228c50d8ae3SPaolo Bonzini } 2229c50d8ae3SPaolo Bonzini 223094c81364SDavid Matlack sp = NULL; 22313cc736b3SDavid Matlack ++kvm->stat.mmu_cache_miss; 2232c50d8ae3SPaolo Bonzini 223394c81364SDavid Matlack out: 22343cc736b3SDavid Matlack kvm_mmu_commit_zap_page(kvm, &invalid_list); 223594c81364SDavid Matlack 22363cc736b3SDavid Matlack if (collisions > kvm->stat.max_mmu_page_hash_collisions) 22373cc736b3SDavid Matlack kvm->stat.max_mmu_page_hash_collisions = collisions; 223894c81364SDavid Matlack return sp; 223994c81364SDavid Matlack } 224094c81364SDavid Matlack 22412f8b1b53SDavid Matlack /* Caches used when allocating a new shadow page. */ 22422f8b1b53SDavid Matlack struct shadow_page_caches { 22432f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *page_header_cache; 22442f8b1b53SDavid Matlack struct kvm_mmu_memory_cache *shadow_page_cache; 22456a97575dSDavid Matlack struct kvm_mmu_memory_cache *shadowed_info_cache; 22462f8b1b53SDavid Matlack }; 22472f8b1b53SDavid Matlack 2248336081fbSDavid Matlack static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 22492f8b1b53SDavid Matlack struct shadow_page_caches *caches, 225094c81364SDavid Matlack gfn_t gfn, 225194c81364SDavid Matlack struct hlist_head *sp_list, 225294c81364SDavid Matlack union kvm_mmu_page_role role) 225394c81364SDavid Matlack { 2254c306aec8SDavid Matlack struct kvm_mmu_page *sp; 2255c306aec8SDavid Matlack 22562f8b1b53SDavid Matlack sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache); 22572f8b1b53SDavid Matlack sp->spt = kvm_mmu_memory_cache_alloc(caches->shadow_page_cache); 2258c306aec8SDavid Matlack if (!role.direct) 22596a97575dSDavid Matlack sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache); 2260c306aec8SDavid Matlack 2261c306aec8SDavid Matlack set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 2262c306aec8SDavid Matlack 226355c510e2SSean Christopherson INIT_LIST_HEAD(&sp->possible_nx_huge_page_link); 2264428e9216SSean Christopherson 2265c306aec8SDavid Matlack /* 2266c306aec8SDavid Matlack * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages() 2267c306aec8SDavid Matlack * depends on valid pages being added to the head of the list. See 2268c306aec8SDavid Matlack * comments in kvm_zap_obsolete_pages(). 2269c306aec8SDavid Matlack */ 2270336081fbSDavid Matlack sp->mmu_valid_gen = kvm->arch.mmu_valid_gen; 2271336081fbSDavid Matlack list_add(&sp->link, &kvm->arch.active_mmu_pages); 227243a063caSYosry Ahmed kvm_account_mmu_page(kvm, sp); 2273c50d8ae3SPaolo Bonzini 2274c50d8ae3SPaolo Bonzini sp->gfn = gfn; 2275c50d8ae3SPaolo Bonzini sp->role = role; 2276ac101b7cSSean Christopherson hlist_add_head(&sp->hash_link, sp_list); 2277be911771SDavid Matlack if (sp_has_gptes(sp)) 2278336081fbSDavid Matlack account_shadowed(kvm, sp); 2279ddc16abbSSean Christopherson 228094c81364SDavid Matlack return sp; 228194c81364SDavid Matlack } 228294c81364SDavid Matlack 2283cbd858b1SDavid Matlack /* Note, @vcpu may be NULL if @role.direct is true; see kvm_mmu_find_shadow_page. */ 22843cc736b3SDavid Matlack static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm, 22853cc736b3SDavid Matlack struct kvm_vcpu *vcpu, 22862f8b1b53SDavid Matlack struct shadow_page_caches *caches, 228787654643SDavid Matlack gfn_t gfn, 228894c81364SDavid Matlack union kvm_mmu_page_role role) 228994c81364SDavid Matlack { 229094c81364SDavid Matlack struct hlist_head *sp_list; 229194c81364SDavid Matlack struct kvm_mmu_page *sp; 229294c81364SDavid Matlack bool created = false; 229394c81364SDavid Matlack 22943cc736b3SDavid Matlack sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; 229594c81364SDavid Matlack 22963cc736b3SDavid Matlack sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role); 229794c81364SDavid Matlack if (!sp) { 229894c81364SDavid Matlack created = true; 22993cc736b3SDavid Matlack sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role); 230094c81364SDavid Matlack } 230194c81364SDavid Matlack 230294c81364SDavid Matlack trace_kvm_mmu_get_page(sp, created); 2303c50d8ae3SPaolo Bonzini return sp; 2304c50d8ae3SPaolo Bonzini } 2305c50d8ae3SPaolo Bonzini 23062f8b1b53SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 23072f8b1b53SDavid Matlack gfn_t gfn, 23082f8b1b53SDavid Matlack union kvm_mmu_page_role role) 23092f8b1b53SDavid Matlack { 23102f8b1b53SDavid Matlack struct shadow_page_caches caches = { 23112f8b1b53SDavid Matlack .page_header_cache = &vcpu->arch.mmu_page_header_cache, 23122f8b1b53SDavid Matlack .shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache, 23136a97575dSDavid Matlack .shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache, 23142f8b1b53SDavid Matlack }; 23152f8b1b53SDavid Matlack 23163cc736b3SDavid Matlack return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role); 23172f8b1b53SDavid Matlack } 23182f8b1b53SDavid Matlack 231939944ab9SSean Christopherson static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, 232039944ab9SSean Christopherson unsigned int access) 23212e65e842SDavid Matlack { 23222e65e842SDavid Matlack struct kvm_mmu_page *parent_sp = sptep_to_sp(sptep); 23232e65e842SDavid Matlack union kvm_mmu_page_role role; 23242e65e842SDavid Matlack 23252e65e842SDavid Matlack role = parent_sp->role; 23262e65e842SDavid Matlack role.level--; 23272e65e842SDavid Matlack role.access = access; 23282e65e842SDavid Matlack role.direct = direct; 23292e65e842SDavid Matlack role.passthrough = 0; 23302e65e842SDavid Matlack 23312e65e842SDavid Matlack /* 23322e65e842SDavid Matlack * If the guest has 4-byte PTEs then that means it's using 32-bit, 23332e65e842SDavid Matlack * 2-level, non-PAE paging. KVM shadows such guests with PAE paging 23342e65e842SDavid Matlack * (i.e. 8-byte PTEs). The difference in PTE size means that KVM must 23352e65e842SDavid Matlack * shadow each guest page table with multiple shadow page tables, which 23362e65e842SDavid Matlack * requires extra bookkeeping in the role. 23372e65e842SDavid Matlack * 23382e65e842SDavid Matlack * Specifically, to shadow the guest's page directory (which covers a 23392e65e842SDavid Matlack * 4GiB address space), KVM uses 4 PAE page directories, each mapping 23402e65e842SDavid Matlack * 1GiB of the address space. @role.quadrant encodes which quarter of 23412e65e842SDavid Matlack * the address space each maps. 23422e65e842SDavid Matlack * 23432e65e842SDavid Matlack * To shadow the guest's page tables (which each map a 4MiB region), KVM 23442e65e842SDavid Matlack * uses 2 PAE page tables, each mapping a 2MiB region. For these, 23452e65e842SDavid Matlack * @role.quadrant encodes which half of the region they map. 23462e65e842SDavid Matlack * 234739944ab9SSean Christopherson * Concretely, a 4-byte PDE consumes bits 31:22, while an 8-byte PDE 234839944ab9SSean Christopherson * consumes bits 29:21. To consume bits 31:30, KVM's uses 4 shadow 234939944ab9SSean Christopherson * PDPTEs; those 4 PAE page directories are pre-allocated and their 235039944ab9SSean Christopherson * quadrant is assigned in mmu_alloc_root(). A 4-byte PTE consumes 235139944ab9SSean Christopherson * bits 21:12, while an 8-byte PTE consumes bits 20:12. To consume 235239944ab9SSean Christopherson * bit 21 in the PTE (the child here), KVM propagates that bit to the 235339944ab9SSean Christopherson * quadrant, i.e. sets quadrant to '0' or '1'. The parent 8-byte PDE 235439944ab9SSean Christopherson * covers bit 21 (see above), thus the quadrant is calculated from the 235539944ab9SSean Christopherson * _least_ significant bit of the PDE index. 23562e65e842SDavid Matlack */ 23572e65e842SDavid Matlack if (role.has_4_byte_gpte) { 23582e65e842SDavid Matlack WARN_ON_ONCE(role.level != PG_LEVEL_4K); 235979e48cecSSean Christopherson role.quadrant = spte_index(sptep) & 1; 23602e65e842SDavid Matlack } 23612e65e842SDavid Matlack 23622e65e842SDavid Matlack return role; 23632e65e842SDavid Matlack } 23642e65e842SDavid Matlack 23652e65e842SDavid Matlack static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu, 23662e65e842SDavid Matlack u64 *sptep, gfn_t gfn, 23672e65e842SDavid Matlack bool direct, unsigned int access) 23682e65e842SDavid Matlack { 23692e65e842SDavid Matlack union kvm_mmu_page_role role; 23702e65e842SDavid Matlack 23710cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) 23720cd8dc73SPaolo Bonzini return ERR_PTR(-EEXIST); 23730cd8dc73SPaolo Bonzini 23742e65e842SDavid Matlack role = kvm_mmu_child_role(sptep, direct, access); 237587654643SDavid Matlack return kvm_mmu_get_shadow_page(vcpu, gfn, role); 23762e65e842SDavid Matlack } 23772e65e842SDavid Matlack 2378c50d8ae3SPaolo Bonzini static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, 2379c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, hpa_t root, 2380c50d8ae3SPaolo Bonzini u64 addr) 2381c50d8ae3SPaolo Bonzini { 2382c50d8ae3SPaolo Bonzini iterator->addr = addr; 2383c50d8ae3SPaolo Bonzini iterator->shadow_addr = root; 2384a972e29cSPaolo Bonzini iterator->level = vcpu->arch.mmu->root_role.level; 2385c50d8ae3SPaolo Bonzini 238612ec33a7SLai Jiangshan if (iterator->level >= PT64_ROOT_4LEVEL && 23874d25502aSPaolo Bonzini vcpu->arch.mmu->cpu_role.base.level < PT64_ROOT_4LEVEL && 2388347a0d0dSPaolo Bonzini !vcpu->arch.mmu->root_role.direct) 238912ec33a7SLai Jiangshan iterator->level = PT32E_ROOT_LEVEL; 2390c50d8ae3SPaolo Bonzini 2391c50d8ae3SPaolo Bonzini if (iterator->level == PT32E_ROOT_LEVEL) { 2392c50d8ae3SPaolo Bonzini /* 2393c50d8ae3SPaolo Bonzini * prev_root is currently only used for 64-bit hosts. So only 2394c50d8ae3SPaolo Bonzini * the active root_hpa is valid here. 2395c50d8ae3SPaolo Bonzini */ 2396b9e5603cSPaolo Bonzini BUG_ON(root != vcpu->arch.mmu->root.hpa); 2397c50d8ae3SPaolo Bonzini 2398c50d8ae3SPaolo Bonzini iterator->shadow_addr 2399c50d8ae3SPaolo Bonzini = vcpu->arch.mmu->pae_root[(addr >> 30) & 3]; 24002ca3129eSSean Christopherson iterator->shadow_addr &= SPTE_BASE_ADDR_MASK; 2401c50d8ae3SPaolo Bonzini --iterator->level; 2402c50d8ae3SPaolo Bonzini if (!iterator->shadow_addr) 2403c50d8ae3SPaolo Bonzini iterator->level = 0; 2404c50d8ae3SPaolo Bonzini } 2405c50d8ae3SPaolo Bonzini } 2406c50d8ae3SPaolo Bonzini 2407c50d8ae3SPaolo Bonzini static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, 2408c50d8ae3SPaolo Bonzini struct kvm_vcpu *vcpu, u64 addr) 2409c50d8ae3SPaolo Bonzini { 2410b9e5603cSPaolo Bonzini shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu->root.hpa, 2411c50d8ae3SPaolo Bonzini addr); 2412c50d8ae3SPaolo Bonzini } 2413c50d8ae3SPaolo Bonzini 2414c50d8ae3SPaolo Bonzini static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 2415c50d8ae3SPaolo Bonzini { 24163bae0459SSean Christopherson if (iterator->level < PG_LEVEL_4K) 2417c50d8ae3SPaolo Bonzini return false; 2418c50d8ae3SPaolo Bonzini 24192ca3129eSSean Christopherson iterator->index = SPTE_INDEX(iterator->addr, iterator->level); 2420c50d8ae3SPaolo Bonzini iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; 2421c50d8ae3SPaolo Bonzini return true; 2422c50d8ae3SPaolo Bonzini } 2423c50d8ae3SPaolo Bonzini 2424c50d8ae3SPaolo Bonzini static void __shadow_walk_next(struct kvm_shadow_walk_iterator *iterator, 2425c50d8ae3SPaolo Bonzini u64 spte) 2426c50d8ae3SPaolo Bonzini { 24273e44dce4SLai Jiangshan if (!is_shadow_present_pte(spte) || is_last_spte(spte, iterator->level)) { 2428c50d8ae3SPaolo Bonzini iterator->level = 0; 2429c50d8ae3SPaolo Bonzini return; 2430c50d8ae3SPaolo Bonzini } 2431c50d8ae3SPaolo Bonzini 24322ca3129eSSean Christopherson iterator->shadow_addr = spte & SPTE_BASE_ADDR_MASK; 2433c50d8ae3SPaolo Bonzini --iterator->level; 2434c50d8ae3SPaolo Bonzini } 2435c50d8ae3SPaolo Bonzini 2436c50d8ae3SPaolo Bonzini static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) 2437c50d8ae3SPaolo Bonzini { 2438c50d8ae3SPaolo Bonzini __shadow_walk_next(iterator, *iterator->sptep); 2439c50d8ae3SPaolo Bonzini } 2440c50d8ae3SPaolo Bonzini 24410cd8dc73SPaolo Bonzini static void __link_shadow_page(struct kvm *kvm, 24420cd8dc73SPaolo Bonzini struct kvm_mmu_memory_cache *cache, u64 *sptep, 244303787394SPaolo Bonzini struct kvm_mmu_page *sp, bool flush) 2444c50d8ae3SPaolo Bonzini { 2445c50d8ae3SPaolo Bonzini u64 spte; 2446c50d8ae3SPaolo Bonzini 2447c50d8ae3SPaolo Bonzini BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); 2448c50d8ae3SPaolo Bonzini 24490cd8dc73SPaolo Bonzini /* 24500cd8dc73SPaolo Bonzini * If an SPTE is present already, it must be a leaf and therefore 245103787394SPaolo Bonzini * a large one. Drop it, and flush the TLB if needed, before 245203787394SPaolo Bonzini * installing sp. 24530cd8dc73SPaolo Bonzini */ 24540cd8dc73SPaolo Bonzini if (is_shadow_present_pte(*sptep)) 245503787394SPaolo Bonzini drop_large_spte(kvm, sptep, flush); 24560cd8dc73SPaolo Bonzini 2457cc4674d0SBen Gardon spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp)); 2458c50d8ae3SPaolo Bonzini 2459c50d8ae3SPaolo Bonzini mmu_spte_set(sptep, spte); 2460c50d8ae3SPaolo Bonzini 24612ff9039aSDavid Matlack mmu_page_add_parent_pte(cache, sp, sptep); 2462c50d8ae3SPaolo Bonzini 2463c4a48868SLai Jiangshan /* 2464c4a48868SLai Jiangshan * The non-direct sub-pagetable must be updated before linking. For 2465c4a48868SLai Jiangshan * L1 sp, the pagetable is updated via kvm_sync_page() in 2466c4a48868SLai Jiangshan * kvm_mmu_find_shadow_page() without write-protecting the gfn, 2467c4a48868SLai Jiangshan * so sp->unsync can be true or false. For higher level non-direct 2468c4a48868SLai Jiangshan * sp, the pagetable is updated/synced via mmu_sync_children() in 2469c4a48868SLai Jiangshan * FNAME(fetch)(), so sp->unsync_children can only be false. 2470c4a48868SLai Jiangshan * WARN_ON_ONCE() if anything happens unexpectedly. 2471c4a48868SLai Jiangshan */ 2472c4a48868SLai Jiangshan if (WARN_ON_ONCE(sp->unsync_children) || sp->unsync) 2473c50d8ae3SPaolo Bonzini mark_unsync(sptep); 2474c50d8ae3SPaolo Bonzini } 2475c50d8ae3SPaolo Bonzini 24762ff9039aSDavid Matlack static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, 24772ff9039aSDavid Matlack struct kvm_mmu_page *sp) 24782ff9039aSDavid Matlack { 247903787394SPaolo Bonzini __link_shadow_page(vcpu->kvm, &vcpu->arch.mmu_pte_list_desc_cache, sptep, sp, true); 24802ff9039aSDavid Matlack } 24812ff9039aSDavid Matlack 2482c50d8ae3SPaolo Bonzini static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, 2483c50d8ae3SPaolo Bonzini unsigned direct_access) 2484c50d8ae3SPaolo Bonzini { 2485c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)) { 2486c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2487c50d8ae3SPaolo Bonzini 2488c50d8ae3SPaolo Bonzini /* 2489c50d8ae3SPaolo Bonzini * For the direct sp, if the guest pte's dirty bit 2490c50d8ae3SPaolo Bonzini * changed form clean to dirty, it will corrupt the 2491c50d8ae3SPaolo Bonzini * sp's access: allow writable in the read-only sp, 2492c50d8ae3SPaolo Bonzini * so we should update the spte at this point to get 2493c50d8ae3SPaolo Bonzini * a new sp with the correct access. 2494c50d8ae3SPaolo Bonzini */ 24955e3edd7eSSean Christopherson child = spte_to_child_sp(*sptep); 2496c50d8ae3SPaolo Bonzini if (child->role.access == direct_access) 2497c50d8ae3SPaolo Bonzini return; 2498c50d8ae3SPaolo Bonzini 2499c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 25003cdf9374SHou Wenlong kvm_flush_remote_tlbs_sptep(vcpu->kvm, sptep); 2501c50d8ae3SPaolo Bonzini } 2502c50d8ae3SPaolo Bonzini } 2503c50d8ae3SPaolo Bonzini 25042de4085cSBen Gardon /* Returns the number of zapped non-leaf child shadow pages. */ 25052de4085cSBen Gardon static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, 25062de4085cSBen Gardon u64 *spte, struct list_head *invalid_list) 2507c50d8ae3SPaolo Bonzini { 2508c50d8ae3SPaolo Bonzini u64 pte; 2509c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2510c50d8ae3SPaolo Bonzini 2511c50d8ae3SPaolo Bonzini pte = *spte; 2512c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(pte)) { 2513c50d8ae3SPaolo Bonzini if (is_last_spte(pte, sp->role.level)) { 2514c50d8ae3SPaolo Bonzini drop_spte(kvm, spte); 2515c50d8ae3SPaolo Bonzini } else { 25165e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2517c50d8ae3SPaolo Bonzini drop_parent_pte(child, spte); 25182de4085cSBen Gardon 25192de4085cSBen Gardon /* 25202de4085cSBen Gardon * Recursively zap nested TDP SPs, parentless SPs are 25212de4085cSBen Gardon * unlikely to be used again in the near future. This 25222de4085cSBen Gardon * avoids retaining a large number of stale nested SPs. 25232de4085cSBen Gardon */ 25242de4085cSBen Gardon if (tdp_enabled && invalid_list && 25252de4085cSBen Gardon child->role.guest_mode && !child->parent_ptes.val) 25262de4085cSBen Gardon return kvm_mmu_prepare_zap_page(kvm, child, 25272de4085cSBen Gardon invalid_list); 2528c50d8ae3SPaolo Bonzini } 2529ace569e0SSean Christopherson } else if (is_mmio_spte(pte)) { 2530c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(spte); 2531ace569e0SSean Christopherson } 25322de4085cSBen Gardon return 0; 2533c50d8ae3SPaolo Bonzini } 2534c50d8ae3SPaolo Bonzini 25352de4085cSBen Gardon static int kvm_mmu_page_unlink_children(struct kvm *kvm, 25362de4085cSBen Gardon struct kvm_mmu_page *sp, 25372de4085cSBen Gardon struct list_head *invalid_list) 2538c50d8ae3SPaolo Bonzini { 25392de4085cSBen Gardon int zapped = 0; 2540c50d8ae3SPaolo Bonzini unsigned i; 2541c50d8ae3SPaolo Bonzini 25422ca3129eSSean Christopherson for (i = 0; i < SPTE_ENT_PER_PAGE; ++i) 25432de4085cSBen Gardon zapped += mmu_page_zap_pte(kvm, sp, sp->spt + i, invalid_list); 25442de4085cSBen Gardon 25452de4085cSBen Gardon return zapped; 2546c50d8ae3SPaolo Bonzini } 2547c50d8ae3SPaolo Bonzini 254861827671SJinrong Liang static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp) 2549c50d8ae3SPaolo Bonzini { 2550c50d8ae3SPaolo Bonzini u64 *sptep; 2551c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 2552c50d8ae3SPaolo Bonzini 2553c50d8ae3SPaolo Bonzini while ((sptep = rmap_get_first(&sp->parent_ptes, &iter))) 2554c50d8ae3SPaolo Bonzini drop_parent_pte(sp, sptep); 2555c50d8ae3SPaolo Bonzini } 2556c50d8ae3SPaolo Bonzini 2557c50d8ae3SPaolo Bonzini static int mmu_zap_unsync_children(struct kvm *kvm, 2558c50d8ae3SPaolo Bonzini struct kvm_mmu_page *parent, 2559c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2560c50d8ae3SPaolo Bonzini { 2561c50d8ae3SPaolo Bonzini int i, zapped = 0; 2562c50d8ae3SPaolo Bonzini struct mmu_page_path parents; 2563c50d8ae3SPaolo Bonzini struct kvm_mmu_pages pages; 2564c50d8ae3SPaolo Bonzini 25653bae0459SSean Christopherson if (parent->role.level == PG_LEVEL_4K) 2566c50d8ae3SPaolo Bonzini return 0; 2567c50d8ae3SPaolo Bonzini 2568c50d8ae3SPaolo Bonzini while (mmu_unsync_walk(parent, &pages)) { 2569c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2570c50d8ae3SPaolo Bonzini 2571c50d8ae3SPaolo Bonzini for_each_sp(pages, sp, parents, i) { 2572c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 2573c50d8ae3SPaolo Bonzini mmu_pages_clear_parents(&parents); 2574c50d8ae3SPaolo Bonzini zapped++; 2575c50d8ae3SPaolo Bonzini } 2576c50d8ae3SPaolo Bonzini } 2577c50d8ae3SPaolo Bonzini 2578c50d8ae3SPaolo Bonzini return zapped; 2579c50d8ae3SPaolo Bonzini } 2580c50d8ae3SPaolo Bonzini 2581c50d8ae3SPaolo Bonzini static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 2582c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 2583c50d8ae3SPaolo Bonzini struct list_head *invalid_list, 2584c50d8ae3SPaolo Bonzini int *nr_zapped) 2585c50d8ae3SPaolo Bonzini { 2586527d5cd7SSean Christopherson bool list_unstable, zapped_root = false; 2587c50d8ae3SPaolo Bonzini 258847b0c2e4SKazuki Takiguchi lockdep_assert_held_write(&kvm->mmu_lock); 2589c50d8ae3SPaolo Bonzini trace_kvm_mmu_prepare_zap_page(sp); 2590c50d8ae3SPaolo Bonzini ++kvm->stat.mmu_shadow_zapped; 2591c50d8ae3SPaolo Bonzini *nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list); 25922de4085cSBen Gardon *nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list); 259361827671SJinrong Liang kvm_mmu_unlink_parents(sp); 2594c50d8ae3SPaolo Bonzini 2595c50d8ae3SPaolo Bonzini /* Zapping children means active_mmu_pages has become unstable. */ 2596c50d8ae3SPaolo Bonzini list_unstable = *nr_zapped; 2597c50d8ae3SPaolo Bonzini 2598767d8d8dSLai Jiangshan if (!sp->role.invalid && sp_has_gptes(sp)) 2599c50d8ae3SPaolo Bonzini unaccount_shadowed(kvm, sp); 2600c50d8ae3SPaolo Bonzini 2601c50d8ae3SPaolo Bonzini if (sp->unsync) 2602c50d8ae3SPaolo Bonzini kvm_unlink_unsync_page(kvm, sp); 2603c50d8ae3SPaolo Bonzini if (!sp->root_count) { 2604c50d8ae3SPaolo Bonzini /* Count self */ 2605c50d8ae3SPaolo Bonzini (*nr_zapped)++; 2606f95eec9bSSean Christopherson 2607f95eec9bSSean Christopherson /* 2608f95eec9bSSean Christopherson * Already invalid pages (previously active roots) are not on 2609f95eec9bSSean Christopherson * the active page list. See list_del() in the "else" case of 2610f95eec9bSSean Christopherson * !sp->root_count. 2611f95eec9bSSean Christopherson */ 2612f95eec9bSSean Christopherson if (sp->role.invalid) 2613f95eec9bSSean Christopherson list_add(&sp->link, invalid_list); 2614f95eec9bSSean Christopherson else 2615c50d8ae3SPaolo Bonzini list_move(&sp->link, invalid_list); 261643a063caSYosry Ahmed kvm_unaccount_mmu_page(kvm, sp); 2617c50d8ae3SPaolo Bonzini } else { 2618f95eec9bSSean Christopherson /* 2619f95eec9bSSean Christopherson * Remove the active root from the active page list, the root 2620f95eec9bSSean Christopherson * will be explicitly freed when the root_count hits zero. 2621f95eec9bSSean Christopherson */ 2622f95eec9bSSean Christopherson list_del(&sp->link); 2623c50d8ae3SPaolo Bonzini 2624c50d8ae3SPaolo Bonzini /* 2625c50d8ae3SPaolo Bonzini * Obsolete pages cannot be used on any vCPUs, see the comment 2626c50d8ae3SPaolo Bonzini * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also 2627c50d8ae3SPaolo Bonzini * treats invalid shadow pages as being obsolete. 2628c50d8ae3SPaolo Bonzini */ 2629527d5cd7SSean Christopherson zapped_root = !is_obsolete_sp(kvm, sp); 2630c50d8ae3SPaolo Bonzini } 2631c50d8ae3SPaolo Bonzini 263255c510e2SSean Christopherson if (sp->nx_huge_page_disallowed) 263355c510e2SSean Christopherson unaccount_nx_huge_page(kvm, sp); 2634c50d8ae3SPaolo Bonzini 2635c50d8ae3SPaolo Bonzini sp->role.invalid = 1; 2636527d5cd7SSean Christopherson 2637527d5cd7SSean Christopherson /* 2638527d5cd7SSean Christopherson * Make the request to free obsolete roots after marking the root 2639527d5cd7SSean Christopherson * invalid, otherwise other vCPUs may not see it as invalid. 2640527d5cd7SSean Christopherson */ 2641527d5cd7SSean Christopherson if (zapped_root) 2642527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 2643c50d8ae3SPaolo Bonzini return list_unstable; 2644c50d8ae3SPaolo Bonzini } 2645c50d8ae3SPaolo Bonzini 2646c50d8ae3SPaolo Bonzini static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2647c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2648c50d8ae3SPaolo Bonzini { 2649c50d8ae3SPaolo Bonzini int nr_zapped; 2650c50d8ae3SPaolo Bonzini 2651c50d8ae3SPaolo Bonzini __kvm_mmu_prepare_zap_page(kvm, sp, invalid_list, &nr_zapped); 2652c50d8ae3SPaolo Bonzini return nr_zapped; 2653c50d8ae3SPaolo Bonzini } 2654c50d8ae3SPaolo Bonzini 2655c50d8ae3SPaolo Bonzini static void kvm_mmu_commit_zap_page(struct kvm *kvm, 2656c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 2657c50d8ae3SPaolo Bonzini { 2658c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *nsp; 2659c50d8ae3SPaolo Bonzini 2660c50d8ae3SPaolo Bonzini if (list_empty(invalid_list)) 2661c50d8ae3SPaolo Bonzini return; 2662c50d8ae3SPaolo Bonzini 2663c50d8ae3SPaolo Bonzini /* 2664c50d8ae3SPaolo Bonzini * We need to make sure everyone sees our modifications to 2665c50d8ae3SPaolo Bonzini * the page tables and see changes to vcpu->mode here. The barrier 2666c50d8ae3SPaolo Bonzini * in the kvm_flush_remote_tlbs() achieves this. This pairs 2667c50d8ae3SPaolo Bonzini * with vcpu_enter_guest and walk_shadow_page_lockless_begin/end. 2668c50d8ae3SPaolo Bonzini * 2669c50d8ae3SPaolo Bonzini * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit 2670c50d8ae3SPaolo Bonzini * guest mode and/or lockless shadow page table walks. 2671c50d8ae3SPaolo Bonzini */ 2672c50d8ae3SPaolo Bonzini kvm_flush_remote_tlbs(kvm); 2673c50d8ae3SPaolo Bonzini 2674c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, nsp, invalid_list, link) { 2675c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.invalid || sp->root_count); 267687654643SDavid Matlack kvm_mmu_free_shadow_page(sp); 2677c50d8ae3SPaolo Bonzini } 2678c50d8ae3SPaolo Bonzini } 2679c50d8ae3SPaolo Bonzini 26806b82ef2cSSean Christopherson static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm, 26816b82ef2cSSean Christopherson unsigned long nr_to_zap) 2682c50d8ae3SPaolo Bonzini { 26836b82ef2cSSean Christopherson unsigned long total_zapped = 0; 26846b82ef2cSSean Christopherson struct kvm_mmu_page *sp, *tmp; 2685ba7888ddSSean Christopherson LIST_HEAD(invalid_list); 26866b82ef2cSSean Christopherson bool unstable; 26876b82ef2cSSean Christopherson int nr_zapped; 2688c50d8ae3SPaolo Bonzini 2689c50d8ae3SPaolo Bonzini if (list_empty(&kvm->arch.active_mmu_pages)) 2690ba7888ddSSean Christopherson return 0; 2691c50d8ae3SPaolo Bonzini 26926b82ef2cSSean Christopherson restart: 26938fc51726SSean Christopherson list_for_each_entry_safe_reverse(sp, tmp, &kvm->arch.active_mmu_pages, link) { 26946b82ef2cSSean Christopherson /* 26956b82ef2cSSean Christopherson * Don't zap active root pages, the page itself can't be freed 26966b82ef2cSSean Christopherson * and zapping it will just force vCPUs to realloc and reload. 26976b82ef2cSSean Christopherson */ 26986b82ef2cSSean Christopherson if (sp->root_count) 26996b82ef2cSSean Christopherson continue; 27006b82ef2cSSean Christopherson 27016b82ef2cSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, 27026b82ef2cSSean Christopherson &nr_zapped); 27036b82ef2cSSean Christopherson total_zapped += nr_zapped; 27046b82ef2cSSean Christopherson if (total_zapped >= nr_to_zap) 2705ba7888ddSSean Christopherson break; 2706ba7888ddSSean Christopherson 27076b82ef2cSSean Christopherson if (unstable) 27086b82ef2cSSean Christopherson goto restart; 2709ba7888ddSSean Christopherson } 27106b82ef2cSSean Christopherson 27116b82ef2cSSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 27126b82ef2cSSean Christopherson 27136b82ef2cSSean Christopherson kvm->stat.mmu_recycled += total_zapped; 27146b82ef2cSSean Christopherson return total_zapped; 27156b82ef2cSSean Christopherson } 27166b82ef2cSSean Christopherson 2717afe8d7e6SSean Christopherson static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) 2718afe8d7e6SSean Christopherson { 2719afe8d7e6SSean Christopherson if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) 2720afe8d7e6SSean Christopherson return kvm->arch.n_max_mmu_pages - 2721afe8d7e6SSean Christopherson kvm->arch.n_used_mmu_pages; 2722afe8d7e6SSean Christopherson 2723afe8d7e6SSean Christopherson return 0; 2724c50d8ae3SPaolo Bonzini } 2725c50d8ae3SPaolo Bonzini 2726ba7888ddSSean Christopherson static int make_mmu_pages_available(struct kvm_vcpu *vcpu) 2727ba7888ddSSean Christopherson { 27286b82ef2cSSean Christopherson unsigned long avail = kvm_mmu_available_pages(vcpu->kvm); 2729ba7888ddSSean Christopherson 27306b82ef2cSSean Christopherson if (likely(avail >= KVM_MIN_FREE_MMU_PAGES)) 2731ba7888ddSSean Christopherson return 0; 2732ba7888ddSSean Christopherson 27336b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); 2734ba7888ddSSean Christopherson 27356e6ec584SSean Christopherson /* 27366e6ec584SSean Christopherson * Note, this check is intentionally soft, it only guarantees that one 27376e6ec584SSean Christopherson * page is available, while the caller may end up allocating as many as 27386e6ec584SSean Christopherson * four pages, e.g. for PAE roots or for 5-level paging. Temporarily 27396e6ec584SSean Christopherson * exceeding the (arbitrary by default) limit will not harm the host, 2740c4342633SIngo Molnar * being too aggressive may unnecessarily kill the guest, and getting an 27416e6ec584SSean Christopherson * exact count is far more trouble than it's worth, especially in the 27426e6ec584SSean Christopherson * page fault paths. 27436e6ec584SSean Christopherson */ 2744ba7888ddSSean Christopherson if (!kvm_mmu_available_pages(vcpu->kvm)) 2745ba7888ddSSean Christopherson return -ENOSPC; 2746ba7888ddSSean Christopherson return 0; 2747ba7888ddSSean Christopherson } 2748ba7888ddSSean Christopherson 2749c50d8ae3SPaolo Bonzini /* 2750c50d8ae3SPaolo Bonzini * Changing the number of mmu pages allocated to the vm 2751c50d8ae3SPaolo Bonzini * Note: if goal_nr_mmu_pages is too small, you will get dead lock 2752c50d8ae3SPaolo Bonzini */ 2753c50d8ae3SPaolo Bonzini void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long goal_nr_mmu_pages) 2754c50d8ae3SPaolo Bonzini { 2755531810caSBen Gardon write_lock(&kvm->mmu_lock); 2756c50d8ae3SPaolo Bonzini 2757c50d8ae3SPaolo Bonzini if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { 27586b82ef2cSSean Christopherson kvm_mmu_zap_oldest_mmu_pages(kvm, kvm->arch.n_used_mmu_pages - 27596b82ef2cSSean Christopherson goal_nr_mmu_pages); 2760c50d8ae3SPaolo Bonzini 2761c50d8ae3SPaolo Bonzini goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; 2762c50d8ae3SPaolo Bonzini } 2763c50d8ae3SPaolo Bonzini 2764c50d8ae3SPaolo Bonzini kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; 2765c50d8ae3SPaolo Bonzini 2766531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2767c50d8ae3SPaolo Bonzini } 2768c50d8ae3SPaolo Bonzini 2769c50d8ae3SPaolo Bonzini int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 2770c50d8ae3SPaolo Bonzini { 2771c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2772c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 2773c50d8ae3SPaolo Bonzini int r; 2774c50d8ae3SPaolo Bonzini 2775c50d8ae3SPaolo Bonzini pgprintk("%s: looking for gfn %llx\n", __func__, gfn); 2776c50d8ae3SPaolo Bonzini r = 0; 2777531810caSBen Gardon write_lock(&kvm->mmu_lock); 2778767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2779c50d8ae3SPaolo Bonzini pgprintk("%s: gfn %llx role %x\n", __func__, gfn, 2780c50d8ae3SPaolo Bonzini sp->role.word); 2781c50d8ae3SPaolo Bonzini r = 1; 2782c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 2783c50d8ae3SPaolo Bonzini } 2784c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 2785531810caSBen Gardon write_unlock(&kvm->mmu_lock); 2786c50d8ae3SPaolo Bonzini 2787c50d8ae3SPaolo Bonzini return r; 2788c50d8ae3SPaolo Bonzini } 278996ad91aeSSean Christopherson 279096ad91aeSSean Christopherson static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 279196ad91aeSSean Christopherson { 279296ad91aeSSean Christopherson gpa_t gpa; 279396ad91aeSSean Christopherson int r; 279496ad91aeSSean Christopherson 2795347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 279696ad91aeSSean Christopherson return 0; 279796ad91aeSSean Christopherson 279896ad91aeSSean Christopherson gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); 279996ad91aeSSean Christopherson 280096ad91aeSSean Christopherson r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); 280196ad91aeSSean Christopherson 280296ad91aeSSean Christopherson return r; 280396ad91aeSSean Christopherson } 2804c50d8ae3SPaolo Bonzini 28054d78d0b3SBen Gardon static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 2806c50d8ae3SPaolo Bonzini { 2807c50d8ae3SPaolo Bonzini trace_kvm_mmu_unsync_page(sp); 28084d78d0b3SBen Gardon ++kvm->stat.mmu_unsync; 2809c50d8ae3SPaolo Bonzini sp->unsync = 1; 2810c50d8ae3SPaolo Bonzini 2811c50d8ae3SPaolo Bonzini kvm_mmu_mark_parents_unsync(sp); 2812c50d8ae3SPaolo Bonzini } 2813c50d8ae3SPaolo Bonzini 28140337f585SSean Christopherson /* 28150337f585SSean Christopherson * Attempt to unsync any shadow pages that can be reached by the specified gfn, 28160337f585SSean Christopherson * KVM is creating a writable mapping for said gfn. Returns 0 if all pages 28170337f585SSean Christopherson * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must 28180337f585SSean Christopherson * be write-protected. 28190337f585SSean Christopherson */ 28208283e36aSBen Gardon int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 28212839180cSPaolo Bonzini gfn_t gfn, bool can_unsync, bool prefetch) 2822c50d8ae3SPaolo Bonzini { 2823c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 2824ce25681dSSean Christopherson bool locked = false; 2825c50d8ae3SPaolo Bonzini 28260337f585SSean Christopherson /* 28270337f585SSean Christopherson * Force write-protection if the page is being tracked. Note, the page 28280337f585SSean Christopherson * track machinery is used to write-protect upper-level shadow pages, 28290337f585SSean Christopherson * i.e. this guards the role.level == 4K assertion below! 28300337f585SSean Christopherson */ 28314d78d0b3SBen Gardon if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE)) 28320337f585SSean Christopherson return -EPERM; 2833c50d8ae3SPaolo Bonzini 28340337f585SSean Christopherson /* 28350337f585SSean Christopherson * The page is not write-tracked, mark existing shadow pages unsync 28360337f585SSean Christopherson * unless KVM is synchronizing an unsync SP (can_unsync = false). In 28370337f585SSean Christopherson * that case, KVM must complete emulation of the guest TLB flush before 28380337f585SSean Christopherson * allowing shadow pages to become unsync (writable by the guest). 28390337f585SSean Christopherson */ 2840767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) { 2841c50d8ae3SPaolo Bonzini if (!can_unsync) 28420337f585SSean Christopherson return -EPERM; 2843c50d8ae3SPaolo Bonzini 2844c50d8ae3SPaolo Bonzini if (sp->unsync) 2845c50d8ae3SPaolo Bonzini continue; 2846c50d8ae3SPaolo Bonzini 28472839180cSPaolo Bonzini if (prefetch) 2848f1c4a88cSLai Jiangshan return -EEXIST; 2849f1c4a88cSLai Jiangshan 2850ce25681dSSean Christopherson /* 2851ce25681dSSean Christopherson * TDP MMU page faults require an additional spinlock as they 2852ce25681dSSean Christopherson * run with mmu_lock held for read, not write, and the unsync 2853ce25681dSSean Christopherson * logic is not thread safe. Take the spinklock regardless of 2854ce25681dSSean Christopherson * the MMU type to avoid extra conditionals/parameters, there's 2855ce25681dSSean Christopherson * no meaningful penalty if mmu_lock is held for write. 2856ce25681dSSean Christopherson */ 2857ce25681dSSean Christopherson if (!locked) { 2858ce25681dSSean Christopherson locked = true; 28594d78d0b3SBen Gardon spin_lock(&kvm->arch.mmu_unsync_pages_lock); 2860ce25681dSSean Christopherson 2861ce25681dSSean Christopherson /* 2862ce25681dSSean Christopherson * Recheck after taking the spinlock, a different vCPU 2863ce25681dSSean Christopherson * may have since marked the page unsync. A false 2864ce25681dSSean Christopherson * positive on the unprotected check above is not 2865ce25681dSSean Christopherson * possible as clearing sp->unsync _must_ hold mmu_lock 2866ce25681dSSean Christopherson * for write, i.e. unsync cannot transition from 0->1 2867ce25681dSSean Christopherson * while this CPU holds mmu_lock for read (or write). 2868ce25681dSSean Christopherson */ 2869ce25681dSSean Christopherson if (READ_ONCE(sp->unsync)) 2870ce25681dSSean Christopherson continue; 2871ce25681dSSean Christopherson } 2872ce25681dSSean Christopherson 28733bae0459SSean Christopherson WARN_ON(sp->role.level != PG_LEVEL_4K); 28744d78d0b3SBen Gardon kvm_unsync_page(kvm, sp); 2875c50d8ae3SPaolo Bonzini } 2876ce25681dSSean Christopherson if (locked) 28774d78d0b3SBen Gardon spin_unlock(&kvm->arch.mmu_unsync_pages_lock); 2878c50d8ae3SPaolo Bonzini 2879c50d8ae3SPaolo Bonzini /* 2880c50d8ae3SPaolo Bonzini * We need to ensure that the marking of unsync pages is visible 2881c50d8ae3SPaolo Bonzini * before the SPTE is updated to allow writes because 2882c50d8ae3SPaolo Bonzini * kvm_mmu_sync_roots() checks the unsync flags without holding 2883c50d8ae3SPaolo Bonzini * the MMU lock and so can race with this. If the SPTE was updated 2884c50d8ae3SPaolo Bonzini * before the page had been marked as unsync-ed, something like the 2885c50d8ae3SPaolo Bonzini * following could happen: 2886c50d8ae3SPaolo Bonzini * 2887c50d8ae3SPaolo Bonzini * CPU 1 CPU 2 2888c50d8ae3SPaolo Bonzini * --------------------------------------------------------------------- 2889c50d8ae3SPaolo Bonzini * 1.2 Host updates SPTE 2890c50d8ae3SPaolo Bonzini * to be writable 2891c50d8ae3SPaolo Bonzini * 2.1 Guest writes a GPTE for GVA X. 2892c50d8ae3SPaolo Bonzini * (GPTE being in the guest page table shadowed 2893c50d8ae3SPaolo Bonzini * by the SP from CPU 1.) 2894c50d8ae3SPaolo Bonzini * This reads SPTE during the page table walk. 2895c50d8ae3SPaolo Bonzini * Since SPTE.W is read as 1, there is no 2896c50d8ae3SPaolo Bonzini * fault. 2897c50d8ae3SPaolo Bonzini * 2898c50d8ae3SPaolo Bonzini * 2.2 Guest issues TLB flush. 2899c50d8ae3SPaolo Bonzini * That causes a VM Exit. 2900c50d8ae3SPaolo Bonzini * 29010337f585SSean Christopherson * 2.3 Walking of unsync pages sees sp->unsync is 29020337f585SSean Christopherson * false and skips the page. 2903c50d8ae3SPaolo Bonzini * 2904c50d8ae3SPaolo Bonzini * 2.4 Guest accesses GVA X. 2905c50d8ae3SPaolo Bonzini * Since the mapping in the SP was not updated, 2906c50d8ae3SPaolo Bonzini * so the old mapping for GVA X incorrectly 2907c50d8ae3SPaolo Bonzini * gets used. 2908c50d8ae3SPaolo Bonzini * 1.1 Host marks SP 2909c50d8ae3SPaolo Bonzini * as unsync 2910c50d8ae3SPaolo Bonzini * (sp->unsync = true) 2911c50d8ae3SPaolo Bonzini * 2912c50d8ae3SPaolo Bonzini * The write barrier below ensures that 1.1 happens before 1.2 and thus 2913264d3dc1SLai Jiangshan * the situation in 2.4 does not arise. It pairs with the read barrier 2914264d3dc1SLai Jiangshan * in is_unsync_root(), placed between 2.1's load of SPTE.W and 2.3. 2915c50d8ae3SPaolo Bonzini */ 2916c50d8ae3SPaolo Bonzini smp_wmb(); 2917c50d8ae3SPaolo Bonzini 29180337f585SSean Christopherson return 0; 2919c50d8ae3SPaolo Bonzini } 2920c50d8ae3SPaolo Bonzini 29218a9f566aSDavid Matlack static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 29228a9f566aSDavid Matlack u64 *sptep, unsigned int pte_access, gfn_t gfn, 2923a12f4381SPaolo Bonzini kvm_pfn_t pfn, struct kvm_page_fault *fault) 2924799a4190SBen Gardon { 2925d786c778SPaolo Bonzini struct kvm_mmu_page *sp = sptep_to_sp(sptep); 2926eb5cd7ffSPaolo Bonzini int level = sp->role.level; 2927c50d8ae3SPaolo Bonzini int was_rmapped = 0; 2928c4371c2aSSean Christopherson int ret = RET_PF_FIXED; 2929c50d8ae3SPaolo Bonzini bool flush = false; 2930ad67e480SPaolo Bonzini bool wrprot; 2931d786c778SPaolo Bonzini u64 spte; 2932c50d8ae3SPaolo Bonzini 2933a12f4381SPaolo Bonzini /* Prefetching always gets a writable pfn. */ 2934a12f4381SPaolo Bonzini bool host_writable = !fault || fault->map_writable; 29352839180cSPaolo Bonzini bool prefetch = !fault || fault->prefetch; 2936a12f4381SPaolo Bonzini bool write_fault = fault && fault->write; 2937c50d8ae3SPaolo Bonzini 2938c50d8ae3SPaolo Bonzini pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, 2939c50d8ae3SPaolo Bonzini *sptep, write_fault, gfn); 2940c50d8ae3SPaolo Bonzini 2941a54aa15cSSean Christopherson if (unlikely(is_noslot_pfn(pfn))) { 29421075d41eSSean Christopherson vcpu->stat.pf_mmio_spte_created++; 2943a54aa15cSSean Christopherson mark_mmio_spte(vcpu, sptep, gfn, pte_access); 2944a54aa15cSSean Christopherson return RET_PF_EMULATE; 2945a54aa15cSSean Christopherson } 2946a54aa15cSSean Christopherson 2947c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 2948c50d8ae3SPaolo Bonzini /* 2949c50d8ae3SPaolo Bonzini * If we overwrite a PTE page pointer with a 2MB PMD, unlink 2950c50d8ae3SPaolo Bonzini * the parent of the now unreachable PTE. 2951c50d8ae3SPaolo Bonzini */ 29523bae0459SSean Christopherson if (level > PG_LEVEL_4K && !is_large_pte(*sptep)) { 2953c50d8ae3SPaolo Bonzini struct kvm_mmu_page *child; 2954c50d8ae3SPaolo Bonzini u64 pte = *sptep; 2955c50d8ae3SPaolo Bonzini 29565e3edd7eSSean Christopherson child = spte_to_child_sp(pte); 2957c50d8ae3SPaolo Bonzini drop_parent_pte(child, sptep); 2958c50d8ae3SPaolo Bonzini flush = true; 2959c50d8ae3SPaolo Bonzini } else if (pfn != spte_to_pfn(*sptep)) { 2960c50d8ae3SPaolo Bonzini pgprintk("hfn old %llx new %llx\n", 2961c50d8ae3SPaolo Bonzini spte_to_pfn(*sptep), pfn); 2962c50d8ae3SPaolo Bonzini drop_spte(vcpu->kvm, sptep); 2963c50d8ae3SPaolo Bonzini flush = true; 2964c50d8ae3SPaolo Bonzini } else 2965c50d8ae3SPaolo Bonzini was_rmapped = 1; 2966c50d8ae3SPaolo Bonzini } 2967c50d8ae3SPaolo Bonzini 29682839180cSPaolo Bonzini wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch, 29697158bee4SPaolo Bonzini true, host_writable, &spte); 2970d786c778SPaolo Bonzini 2971d786c778SPaolo Bonzini if (*sptep == spte) { 2972d786c778SPaolo Bonzini ret = RET_PF_SPURIOUS; 2973d786c778SPaolo Bonzini } else { 2974d786c778SPaolo Bonzini flush |= mmu_spte_update(sptep, spte); 29755959ff4aSMaxim Levitsky trace_kvm_mmu_set_spte(level, gfn, sptep); 2976c50d8ae3SPaolo Bonzini } 2977c50d8ae3SPaolo Bonzini 2978ad67e480SPaolo Bonzini if (wrprot) { 2979c50d8ae3SPaolo Bonzini if (write_fault) 2980c50d8ae3SPaolo Bonzini ret = RET_PF_EMULATE; 2981c50d8ae3SPaolo Bonzini } 2982c50d8ae3SPaolo Bonzini 2983d786c778SPaolo Bonzini if (flush) 29844ad980aeSHou Wenlong kvm_flush_remote_tlbs_gfn(vcpu->kvm, gfn, level); 2985c50d8ae3SPaolo Bonzini 2986c50d8ae3SPaolo Bonzini pgprintk("%s: setting spte %llx\n", __func__, *sptep); 2987c50d8ae3SPaolo Bonzini 2988c50d8ae3SPaolo Bonzini if (!was_rmapped) { 2989d786c778SPaolo Bonzini WARN_ON_ONCE(ret == RET_PF_SPURIOUS); 29906a97575dSDavid Matlack rmap_add(vcpu, slot, sptep, gfn, pte_access); 29916a97575dSDavid Matlack } else { 29926a97575dSDavid Matlack /* Already rmapped but the pte_access bits may have changed. */ 299379e48cecSSean Christopherson kvm_mmu_page_set_access(sp, spte_index(sptep), pte_access); 2994c50d8ae3SPaolo Bonzini } 2995c50d8ae3SPaolo Bonzini 2996c50d8ae3SPaolo Bonzini return ret; 2997c50d8ae3SPaolo Bonzini } 2998c50d8ae3SPaolo Bonzini 2999c50d8ae3SPaolo Bonzini static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 3000c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, 3001c50d8ae3SPaolo Bonzini u64 *start, u64 *end) 3002c50d8ae3SPaolo Bonzini { 3003c50d8ae3SPaolo Bonzini struct page *pages[PTE_PREFETCH_NUM]; 3004c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot; 30050a2b64c5SBen Gardon unsigned int access = sp->role.access; 3006c50d8ae3SPaolo Bonzini int i, ret; 3007c50d8ae3SPaolo Bonzini gfn_t gfn; 3008c50d8ae3SPaolo Bonzini 300979e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(sp, spte_index(start)); 3010c50d8ae3SPaolo Bonzini slot = gfn_to_memslot_dirty_bitmap(vcpu, gfn, access & ACC_WRITE_MASK); 3011c50d8ae3SPaolo Bonzini if (!slot) 3012c50d8ae3SPaolo Bonzini return -1; 3013c50d8ae3SPaolo Bonzini 3014c50d8ae3SPaolo Bonzini ret = gfn_to_page_many_atomic(slot, gfn, pages, end - start); 3015c50d8ae3SPaolo Bonzini if (ret <= 0) 3016c50d8ae3SPaolo Bonzini return -1; 3017c50d8ae3SPaolo Bonzini 3018c50d8ae3SPaolo Bonzini for (i = 0; i < ret; i++, gfn++, start++) { 30198a9f566aSDavid Matlack mmu_set_spte(vcpu, slot, start, access, gfn, 3020a12f4381SPaolo Bonzini page_to_pfn(pages[i]), NULL); 3021c50d8ae3SPaolo Bonzini put_page(pages[i]); 3022c50d8ae3SPaolo Bonzini } 3023c50d8ae3SPaolo Bonzini 3024c50d8ae3SPaolo Bonzini return 0; 3025c50d8ae3SPaolo Bonzini } 3026c50d8ae3SPaolo Bonzini 3027c50d8ae3SPaolo Bonzini static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, 3028c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, u64 *sptep) 3029c50d8ae3SPaolo Bonzini { 3030c50d8ae3SPaolo Bonzini u64 *spte, *start = NULL; 3031c50d8ae3SPaolo Bonzini int i; 3032c50d8ae3SPaolo Bonzini 3033c50d8ae3SPaolo Bonzini WARN_ON(!sp->role.direct); 3034c50d8ae3SPaolo Bonzini 303579e48cecSSean Christopherson i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); 3036c50d8ae3SPaolo Bonzini spte = sp->spt + i; 3037c50d8ae3SPaolo Bonzini 3038c50d8ae3SPaolo Bonzini for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { 3039c50d8ae3SPaolo Bonzini if (is_shadow_present_pte(*spte) || spte == sptep) { 3040c50d8ae3SPaolo Bonzini if (!start) 3041c50d8ae3SPaolo Bonzini continue; 3042c50d8ae3SPaolo Bonzini if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) 3043c6cecc4bSSean Christopherson return; 3044c50d8ae3SPaolo Bonzini start = NULL; 3045c50d8ae3SPaolo Bonzini } else if (!start) 3046c50d8ae3SPaolo Bonzini start = spte; 3047c50d8ae3SPaolo Bonzini } 3048c6cecc4bSSean Christopherson if (start) 3049c6cecc4bSSean Christopherson direct_pte_prefetch_many(vcpu, sp, start, spte); 3050c50d8ae3SPaolo Bonzini } 3051c50d8ae3SPaolo Bonzini 3052c50d8ae3SPaolo Bonzini static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 3053c50d8ae3SPaolo Bonzini { 3054c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3055c50d8ae3SPaolo Bonzini 305657354682SSean Christopherson sp = sptep_to_sp(sptep); 3057c50d8ae3SPaolo Bonzini 3058c50d8ae3SPaolo Bonzini /* 3059c50d8ae3SPaolo Bonzini * Without accessed bits, there's no way to distinguish between 3060c50d8ae3SPaolo Bonzini * actually accessed translations and prefetched, so disable pte 3061c50d8ae3SPaolo Bonzini * prefetch if accessed bits aren't available. 3062c50d8ae3SPaolo Bonzini */ 3063c50d8ae3SPaolo Bonzini if (sp_ad_disabled(sp)) 3064c50d8ae3SPaolo Bonzini return; 3065c50d8ae3SPaolo Bonzini 30663bae0459SSean Christopherson if (sp->role.level > PG_LEVEL_4K) 3067c50d8ae3SPaolo Bonzini return; 3068c50d8ae3SPaolo Bonzini 30694a42d848SDavid Stevens /* 30704a42d848SDavid Stevens * If addresses are being invalidated, skip prefetching to avoid 30714a42d848SDavid Stevens * accidentally prefetching those addresses. 30724a42d848SDavid Stevens */ 307320ec3ebdSChao Peng if (unlikely(vcpu->kvm->mmu_invalidate_in_progress)) 30744a42d848SDavid Stevens return; 30754a42d848SDavid Stevens 3076c50d8ae3SPaolo Bonzini __direct_pte_prefetch(vcpu, sp, sptep); 3077c50d8ae3SPaolo Bonzini } 3078c50d8ae3SPaolo Bonzini 307965e3b446SSean Christopherson /* 308065e3b446SSean Christopherson * Lookup the mapping level for @gfn in the current mm. 308165e3b446SSean Christopherson * 308265e3b446SSean Christopherson * WARNING! Use of host_pfn_mapping_level() requires the caller and the end 308365e3b446SSean Christopherson * consumer to be tied into KVM's handlers for MMU notifier events! 308465e3b446SSean Christopherson * 308565e3b446SSean Christopherson * There are several ways to safely use this helper: 308665e3b446SSean Christopherson * 308720ec3ebdSChao Peng * - Check mmu_invalidate_retry_hva() after grabbing the mapping level, before 308865e3b446SSean Christopherson * consuming it. In this case, mmu_lock doesn't need to be held during the 308965e3b446SSean Christopherson * lookup, but it does need to be held while checking the MMU notifier. 309065e3b446SSean Christopherson * 309165e3b446SSean Christopherson * - Hold mmu_lock AND ensure there is no in-progress MMU notifier invalidation 309265e3b446SSean Christopherson * event for the hva. This can be done by explicit checking the MMU notifier 309365e3b446SSean Christopherson * or by ensuring that KVM already has a valid mapping that covers the hva. 309465e3b446SSean Christopherson * 309565e3b446SSean Christopherson * - Do not use the result to install new mappings, e.g. use the host mapping 309665e3b446SSean Christopherson * level only to decide whether or not to zap an entry. In this case, it's 309765e3b446SSean Christopherson * not required to hold mmu_lock (though it's highly likely the caller will 309865e3b446SSean Christopherson * want to hold mmu_lock anyways, e.g. to modify SPTEs). 309965e3b446SSean Christopherson * 310065e3b446SSean Christopherson * Note! The lookup can still race with modifications to host page tables, but 310165e3b446SSean Christopherson * the above "rules" ensure KVM will not _consume_ the result of the walk if a 310265e3b446SSean Christopherson * race with the primary MMU occurs. 310365e3b446SSean Christopherson */ 3104a8ac499bSSean Christopherson static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, 31058ca6f063SBen Gardon const struct kvm_memory_slot *slot) 3106db543216SSean Christopherson { 3107284dc493SSean Christopherson int level = PG_LEVEL_4K; 3108db543216SSean Christopherson unsigned long hva; 310944187235SMingwei Zhang unsigned long flags; 311044187235SMingwei Zhang pgd_t pgd; 311144187235SMingwei Zhang p4d_t p4d; 311244187235SMingwei Zhang pud_t pud; 311344187235SMingwei Zhang pmd_t pmd; 3114db543216SSean Christopherson 31155d49f08cSSean Christopherson /* 3116293e306eSSean Christopherson * Note, using the already-retrieved memslot and __gfn_to_hva_memslot() 3117293e306eSSean Christopherson * is not solely for performance, it's also necessary to avoid the 3118293e306eSSean Christopherson * "writable" check in __gfn_to_hva_many(), which will always fail on 3119293e306eSSean Christopherson * read-only memslots due to gfn_to_hva() assuming writes. Earlier 3120293e306eSSean Christopherson * page fault steps have already verified the guest isn't writing a 3121293e306eSSean Christopherson * read-only memslot. 3122293e306eSSean Christopherson */ 3123db543216SSean Christopherson hva = __gfn_to_hva_memslot(slot, gfn); 3124db543216SSean Christopherson 312544187235SMingwei Zhang /* 312665e3b446SSean Christopherson * Disable IRQs to prevent concurrent tear down of host page tables, 312765e3b446SSean Christopherson * e.g. if the primary MMU promotes a P*D to a huge page and then frees 312865e3b446SSean Christopherson * the original page table. 312944187235SMingwei Zhang */ 313044187235SMingwei Zhang local_irq_save(flags); 3131db543216SSean Christopherson 313265e3b446SSean Christopherson /* 313365e3b446SSean Christopherson * Read each entry once. As above, a non-leaf entry can be promoted to 313465e3b446SSean Christopherson * a huge page _during_ this walk. Re-reading the entry could send the 313565e3b446SSean Christopherson * walk into the weeks, e.g. p*d_large() returns false (sees the old 313665e3b446SSean Christopherson * value) and then p*d_offset() walks into the target huge page instead 313765e3b446SSean Christopherson * of the old page table (sees the new value). 313865e3b446SSean Christopherson */ 313944187235SMingwei Zhang pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); 314044187235SMingwei Zhang if (pgd_none(pgd)) 314144187235SMingwei Zhang goto out; 314244187235SMingwei Zhang 314344187235SMingwei Zhang p4d = READ_ONCE(*p4d_offset(&pgd, hva)); 314444187235SMingwei Zhang if (p4d_none(p4d) || !p4d_present(p4d)) 314544187235SMingwei Zhang goto out; 314644187235SMingwei Zhang 314744187235SMingwei Zhang pud = READ_ONCE(*pud_offset(&p4d, hva)); 314844187235SMingwei Zhang if (pud_none(pud) || !pud_present(pud)) 314944187235SMingwei Zhang goto out; 315044187235SMingwei Zhang 315144187235SMingwei Zhang if (pud_large(pud)) { 315244187235SMingwei Zhang level = PG_LEVEL_1G; 315344187235SMingwei Zhang goto out; 315444187235SMingwei Zhang } 315544187235SMingwei Zhang 315644187235SMingwei Zhang pmd = READ_ONCE(*pmd_offset(&pud, hva)); 315744187235SMingwei Zhang if (pmd_none(pmd) || !pmd_present(pmd)) 315844187235SMingwei Zhang goto out; 315944187235SMingwei Zhang 316044187235SMingwei Zhang if (pmd_large(pmd)) 316144187235SMingwei Zhang level = PG_LEVEL_2M; 316244187235SMingwei Zhang 316344187235SMingwei Zhang out: 316444187235SMingwei Zhang local_irq_restore(flags); 3165db543216SSean Christopherson return level; 3166db543216SSean Christopherson } 3167db543216SSean Christopherson 31688ca6f063SBen Gardon int kvm_mmu_max_mapping_level(struct kvm *kvm, 31698ca6f063SBen Gardon const struct kvm_memory_slot *slot, gfn_t gfn, 3170a8ac499bSSean Christopherson int max_level) 31711b6d9d9eSSean Christopherson { 31721b6d9d9eSSean Christopherson struct kvm_lpage_info *linfo; 3173ec607a56SPaolo Bonzini int host_level; 31741b6d9d9eSSean Christopherson 31751b6d9d9eSSean Christopherson max_level = min(max_level, max_huge_page_level); 31761b6d9d9eSSean Christopherson for ( ; max_level > PG_LEVEL_4K; max_level--) { 31771b6d9d9eSSean Christopherson linfo = lpage_info_slot(gfn, slot, max_level); 31781b6d9d9eSSean Christopherson if (!linfo->disallow_lpage) 31791b6d9d9eSSean Christopherson break; 31801b6d9d9eSSean Christopherson } 31811b6d9d9eSSean Christopherson 31821b6d9d9eSSean Christopherson if (max_level == PG_LEVEL_4K) 31831b6d9d9eSSean Christopherson return PG_LEVEL_4K; 31841b6d9d9eSSean Christopherson 3185a8ac499bSSean Christopherson host_level = host_pfn_mapping_level(kvm, gfn, slot); 3186ec607a56SPaolo Bonzini return min(host_level, max_level); 31871b6d9d9eSSean Christopherson } 31881b6d9d9eSSean Christopherson 318973a3c659SPaolo Bonzini void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 31900885904dSSean Christopherson { 3191e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 319217eff019SSean Christopherson kvm_pfn_t mask; 31930885904dSSean Christopherson 319473a3c659SPaolo Bonzini fault->huge_page_disallowed = fault->exec && fault->nx_huge_page_workaround_enabled; 31953cf06612SSean Christopherson 319673a3c659SPaolo Bonzini if (unlikely(fault->max_level == PG_LEVEL_4K)) 319773a3c659SPaolo Bonzini return; 319817eff019SSean Christopherson 31995d49f08cSSean Christopherson if (is_error_noslot_pfn(fault->pfn)) 320073a3c659SPaolo Bonzini return; 320117eff019SSean Christopherson 3202e710c5f6SDavid Matlack if (kvm_slot_dirty_track_enabled(slot)) 320373a3c659SPaolo Bonzini return; 3204293e306eSSean Christopherson 32053cf06612SSean Christopherson /* 32063cf06612SSean Christopherson * Enforce the iTLB multihit workaround after capturing the requested 32073cf06612SSean Christopherson * level, which will be used to do precise, accurate accounting. 32083cf06612SSean Christopherson */ 320973a3c659SPaolo Bonzini fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, 3210a8ac499bSSean Christopherson fault->gfn, fault->max_level); 321173a3c659SPaolo Bonzini if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) 321273a3c659SPaolo Bonzini return; 32134cd071d1SSean Christopherson 32140885904dSSean Christopherson /* 321520ec3ebdSChao Peng * mmu_invalidate_retry() was successful and mmu_lock is held, so 32164cd071d1SSean Christopherson * the pmd can't be split from under us. 32170885904dSSean Christopherson */ 321873a3c659SPaolo Bonzini fault->goal_level = fault->req_level; 321973a3c659SPaolo Bonzini mask = KVM_PAGES_PER_HPAGE(fault->goal_level) - 1; 322073a3c659SPaolo Bonzini VM_BUG_ON((fault->gfn & mask) != (fault->pfn & mask)); 322173a3c659SPaolo Bonzini fault->pfn &= ~mask; 32220885904dSSean Christopherson } 32230885904dSSean Christopherson 3224536f0e6aSPaolo Bonzini void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level) 3225c50d8ae3SPaolo Bonzini { 3226536f0e6aSPaolo Bonzini if (cur_level > PG_LEVEL_4K && 3227536f0e6aSPaolo Bonzini cur_level == fault->goal_level && 3228c50d8ae3SPaolo Bonzini is_shadow_present_pte(spte) && 322976901e56SMingwei Zhang !is_large_pte(spte) && 323076901e56SMingwei Zhang spte_to_child_sp(spte)->nx_huge_page_disallowed) { 3231c50d8ae3SPaolo Bonzini /* 32326c882ef4SDavid Matlack * A small SPTE exists for this pfn, but FNAME(fetch), 32336c882ef4SDavid Matlack * direct_map(), or kvm_tdp_mmu_map() would like to create a 32346c882ef4SDavid Matlack * large PTE instead: just force them to go down another level, 32356c882ef4SDavid Matlack * patching back for them into pfn the next 9 bits of the 32366c882ef4SDavid Matlack * address. 3237c50d8ae3SPaolo Bonzini */ 3238536f0e6aSPaolo Bonzini u64 page_mask = KVM_PAGES_PER_HPAGE(cur_level) - 3239536f0e6aSPaolo Bonzini KVM_PAGES_PER_HPAGE(cur_level - 1); 3240536f0e6aSPaolo Bonzini fault->pfn |= fault->gfn & page_mask; 3241536f0e6aSPaolo Bonzini fault->goal_level--; 3242c50d8ae3SPaolo Bonzini } 3243c50d8ae3SPaolo Bonzini } 3244c50d8ae3SPaolo Bonzini 32456c882ef4SDavid Matlack static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3246c50d8ae3SPaolo Bonzini { 3247c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator it; 3248c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 324973a3c659SPaolo Bonzini int ret; 325043b74355SPaolo Bonzini gfn_t base_gfn = fault->gfn; 3251c50d8ae3SPaolo Bonzini 325273a3c659SPaolo Bonzini kvm_mmu_hugepage_adjust(vcpu, fault); 32534cd071d1SSean Christopherson 3254f0066d94SPaolo Bonzini trace_kvm_mmu_spte_requested(fault); 325543b74355SPaolo Bonzini for_each_shadow_entry(vcpu, fault->addr, it) { 3256c50d8ae3SPaolo Bonzini /* 3257c50d8ae3SPaolo Bonzini * We cannot overwrite existing page tables with an NX 3258c50d8ae3SPaolo Bonzini * large page, as the leaf could be executable. 3259c50d8ae3SPaolo Bonzini */ 326073a3c659SPaolo Bonzini if (fault->nx_huge_page_workaround_enabled) 3261536f0e6aSPaolo Bonzini disallowed_hugepage_adjust(fault, *it.sptep, it.level); 3262c50d8ae3SPaolo Bonzini 3263c667a3baSHou Wenlong base_gfn = gfn_round_for_level(fault->gfn, it.level); 326473a3c659SPaolo Bonzini if (it.level == fault->goal_level) 3265c50d8ae3SPaolo Bonzini break; 3266c50d8ae3SPaolo Bonzini 32672e65e842SDavid Matlack sp = kvm_mmu_get_child_sp(vcpu, it.sptep, base_gfn, true, ACC_ALL); 32680cd8dc73SPaolo Bonzini if (sp == ERR_PTR(-EEXIST)) 32690cd8dc73SPaolo Bonzini continue; 3270c50d8ae3SPaolo Bonzini 3271c50d8ae3SPaolo Bonzini link_shadow_page(vcpu, it.sptep, sp); 3272b5b0977fSSean Christopherson if (fault->huge_page_disallowed) 327355c510e2SSean Christopherson account_nx_huge_page(vcpu->kvm, sp, 3274428e9216SSean Christopherson fault->req_level >= it.level); 3275c50d8ae3SPaolo Bonzini } 3276c50d8ae3SPaolo Bonzini 3277b1a429fbSSean Christopherson if (WARN_ON_ONCE(it.level != fault->goal_level)) 3278b1a429fbSSean Christopherson return -EFAULT; 3279b1a429fbSSean Christopherson 32808a9f566aSDavid Matlack ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, 3281a12f4381SPaolo Bonzini base_gfn, fault->pfn, fault); 328212703759SSean Christopherson if (ret == RET_PF_SPURIOUS) 328312703759SSean Christopherson return ret; 328412703759SSean Christopherson 3285c50d8ae3SPaolo Bonzini direct_pte_prefetch(vcpu, it.sptep); 3286c50d8ae3SPaolo Bonzini return ret; 3287c50d8ae3SPaolo Bonzini } 3288c50d8ae3SPaolo Bonzini 3289cd08d178SDavid Matlack static void kvm_send_hwpoison_signal(struct kvm_memory_slot *slot, gfn_t gfn) 3290c50d8ae3SPaolo Bonzini { 3291cd08d178SDavid Matlack unsigned long hva = gfn_to_hva_memslot(slot, gfn); 3292cd08d178SDavid Matlack 3293cd08d178SDavid Matlack send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva, PAGE_SHIFT, current); 3294c50d8ae3SPaolo Bonzini } 3295c50d8ae3SPaolo Bonzini 3296cd08d178SDavid Matlack static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3297c50d8ae3SPaolo Bonzini { 3298cd08d178SDavid Matlack if (is_sigpending_pfn(fault->pfn)) { 329976657687SPeter Xu kvm_handle_signal_exit(vcpu); 330076657687SPeter Xu return -EINTR; 330176657687SPeter Xu } 330276657687SPeter Xu 3303c50d8ae3SPaolo Bonzini /* 3304c50d8ae3SPaolo Bonzini * Do not cache the mmio info caused by writing the readonly gfn 3305c50d8ae3SPaolo Bonzini * into the spte otherwise read access on readonly gfn also can 3306c50d8ae3SPaolo Bonzini * caused mmio page fault and treat it as mmio access. 3307c50d8ae3SPaolo Bonzini */ 3308cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_RO_FAULT) 3309c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 3310c50d8ae3SPaolo Bonzini 3311cd08d178SDavid Matlack if (fault->pfn == KVM_PFN_ERR_HWPOISON) { 3312cd08d178SDavid Matlack kvm_send_hwpoison_signal(fault->slot, fault->gfn); 3313c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 3314c50d8ae3SPaolo Bonzini } 3315c50d8ae3SPaolo Bonzini 3316c50d8ae3SPaolo Bonzini return -EFAULT; 3317c50d8ae3SPaolo Bonzini } 3318c50d8ae3SPaolo Bonzini 3319354c908cSDavid Matlack static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu, 3320354c908cSDavid Matlack struct kvm_page_fault *fault, 33215276c616SSean Christopherson unsigned int access) 3322c50d8ae3SPaolo Bonzini { 33233a13f4feSPaolo Bonzini gva_t gva = fault->is_tdp ? 0 : fault->addr; 33243a13f4feSPaolo Bonzini 33253a13f4feSPaolo Bonzini vcpu_cache_mmio_info(vcpu, gva, fault->gfn, 3326c50d8ae3SPaolo Bonzini access & shadow_mmio_access_mask); 3327354c908cSDavid Matlack 332830ab5901SSean Christopherson /* 332930ab5901SSean Christopherson * If MMIO caching is disabled, emulate immediately without 333030ab5901SSean Christopherson * touching the shadow page tables as attempting to install an 3331354c908cSDavid Matlack * MMIO SPTE will just be an expensive nop. 333230ab5901SSean Christopherson */ 3333354c908cSDavid Matlack if (unlikely(!enable_mmio_caching)) 33345276c616SSean Christopherson return RET_PF_EMULATE; 3335354c908cSDavid Matlack 3336354c908cSDavid Matlack /* 3337354c908cSDavid Matlack * Do not create an MMIO SPTE for a gfn greater than host.MAXPHYADDR, 3338354c908cSDavid Matlack * any guest that generates such gfns is running nested and is being 3339354c908cSDavid Matlack * tricked by L0 userspace (you can observe gfn > L1.MAXPHYADDR if and 3340354c908cSDavid Matlack * only if L1's MAXPHYADDR is inaccurate with respect to the 3341354c908cSDavid Matlack * hardware's). 3342354c908cSDavid Matlack */ 3343354c908cSDavid Matlack if (unlikely(fault->gfn > kvm_mmu_max_gfn())) 3344354c908cSDavid Matlack return RET_PF_EMULATE; 3345c50d8ae3SPaolo Bonzini 33465276c616SSean Christopherson return RET_PF_CONTINUE; 3347c50d8ae3SPaolo Bonzini } 3348c50d8ae3SPaolo Bonzini 33493c8ad5a6SPaolo Bonzini static bool page_fault_can_be_fast(struct kvm_page_fault *fault) 3350c50d8ae3SPaolo Bonzini { 3351c50d8ae3SPaolo Bonzini /* 33525c64aba5SSean Christopherson * Page faults with reserved bits set, i.e. faults on MMIO SPTEs, only 33535c64aba5SSean Christopherson * reach the common page fault handler if the SPTE has an invalid MMIO 33545c64aba5SSean Christopherson * generation number. Refreshing the MMIO generation needs to go down 33555c64aba5SSean Christopherson * the slow path. Note, EPT Misconfigs do NOT set the PRESENT flag! 3356c50d8ae3SPaolo Bonzini */ 33573c8ad5a6SPaolo Bonzini if (fault->rsvd) 3358c50d8ae3SPaolo Bonzini return false; 3359c50d8ae3SPaolo Bonzini 3360c50d8ae3SPaolo Bonzini /* 3361c50d8ae3SPaolo Bonzini * #PF can be fast if: 3362c50d8ae3SPaolo Bonzini * 336354275f74SSean Christopherson * 1. The shadow page table entry is not present and A/D bits are 336454275f74SSean Christopherson * disabled _by KVM_, which could mean that the fault is potentially 336554275f74SSean Christopherson * caused by access tracking (if enabled). If A/D bits are enabled 336654275f74SSean Christopherson * by KVM, but disabled by L1 for L2, KVM is forced to disable A/D 336754275f74SSean Christopherson * bits for L2 and employ access tracking, but the fast page fault 336854275f74SSean Christopherson * mechanism only supports direct MMUs. 336954275f74SSean Christopherson * 2. The shadow page table entry is present, the access is a write, 337054275f74SSean Christopherson * and no reserved bits are set (MMIO SPTEs cannot be "fixed"), i.e. 337154275f74SSean Christopherson * the fault was caused by a write-protection violation. If the 337254275f74SSean Christopherson * SPTE is MMU-writable (determined later), the fault can be fixed 337354275f74SSean Christopherson * by setting the Writable bit, which can be done out of mmu_lock. 3374c50d8ae3SPaolo Bonzini */ 33755c64aba5SSean Christopherson if (!fault->present) 33765c64aba5SSean Christopherson return !kvm_ad_enabled(); 33775c64aba5SSean Christopherson 33785c64aba5SSean Christopherson /* 33795c64aba5SSean Christopherson * Note, instruction fetches and writes are mutually exclusive, ignore 33805c64aba5SSean Christopherson * the "exec" flag. 33815c64aba5SSean Christopherson */ 33825c64aba5SSean Christopherson return fault->write; 3383c50d8ae3SPaolo Bonzini } 3384c50d8ae3SPaolo Bonzini 3385c50d8ae3SPaolo Bonzini /* 3386c50d8ae3SPaolo Bonzini * Returns true if the SPTE was fixed successfully. Otherwise, 3387c50d8ae3SPaolo Bonzini * someone else modified the SPTE from its original value. 3388c50d8ae3SPaolo Bonzini */ 3389f3d90f90SSean Christopherson static bool fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, 3390f3d90f90SSean Christopherson struct kvm_page_fault *fault, 3391c50d8ae3SPaolo Bonzini u64 *sptep, u64 old_spte, u64 new_spte) 3392c50d8ae3SPaolo Bonzini { 3393c50d8ae3SPaolo Bonzini /* 3394c50d8ae3SPaolo Bonzini * Theoretically we could also set dirty bit (and flush TLB) here in 3395c50d8ae3SPaolo Bonzini * order to eliminate unnecessary PML logging. See comments in 3396c50d8ae3SPaolo Bonzini * set_spte. But fast_page_fault is very unlikely to happen with PML 3397c50d8ae3SPaolo Bonzini * enabled, so we do not do this. This might result in the same GPA 3398c50d8ae3SPaolo Bonzini * to be logged in PML buffer again when the write really happens, and 3399c50d8ae3SPaolo Bonzini * eventually to be called by mark_page_dirty twice. But it's also no 3400c50d8ae3SPaolo Bonzini * harm. This also avoids the TLB flush needed after setting dirty bit 3401c50d8ae3SPaolo Bonzini * so non-PML cases won't be impacted. 3402c50d8ae3SPaolo Bonzini * 3403c50d8ae3SPaolo Bonzini * Compare with set_spte where instead shadow_dirty_mask is set. 3404c50d8ae3SPaolo Bonzini */ 34052db2f46fSUros Bizjak if (!try_cmpxchg64(sptep, &old_spte, new_spte)) 3406c50d8ae3SPaolo Bonzini return false; 3407c50d8ae3SPaolo Bonzini 3408e710c5f6SDavid Matlack if (is_writable_pte(new_spte) && !is_writable_pte(old_spte)) 3409e710c5f6SDavid Matlack mark_page_dirty_in_slot(vcpu->kvm, fault->slot, fault->gfn); 3410c50d8ae3SPaolo Bonzini 3411c50d8ae3SPaolo Bonzini return true; 3412c50d8ae3SPaolo Bonzini } 3413c50d8ae3SPaolo Bonzini 34143c8ad5a6SPaolo Bonzini static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte) 3415c50d8ae3SPaolo Bonzini { 34163c8ad5a6SPaolo Bonzini if (fault->exec) 3417c50d8ae3SPaolo Bonzini return is_executable_pte(spte); 3418c50d8ae3SPaolo Bonzini 34193c8ad5a6SPaolo Bonzini if (fault->write) 3420c50d8ae3SPaolo Bonzini return is_writable_pte(spte); 3421c50d8ae3SPaolo Bonzini 3422c50d8ae3SPaolo Bonzini /* Fault was on Read access */ 3423c50d8ae3SPaolo Bonzini return spte & PT_PRESENT_MASK; 3424c50d8ae3SPaolo Bonzini } 3425c50d8ae3SPaolo Bonzini 3426c50d8ae3SPaolo Bonzini /* 34276e8eb206SDavid Matlack * Returns the last level spte pointer of the shadow page walk for the given 34286e8eb206SDavid Matlack * gpa, and sets *spte to the spte value. This spte may be non-preset. If no 34296e8eb206SDavid Matlack * walk could be performed, returns NULL and *spte does not contain valid data. 34306e8eb206SDavid Matlack * 34316e8eb206SDavid Matlack * Contract: 34326e8eb206SDavid Matlack * - Must be called between walk_shadow_page_lockless_{begin,end}. 34336e8eb206SDavid Matlack * - The returned sptep must not be used after walk_shadow_page_lockless_end. 34346e8eb206SDavid Matlack */ 34356e8eb206SDavid Matlack static u64 *fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *spte) 34366e8eb206SDavid Matlack { 34376e8eb206SDavid Matlack struct kvm_shadow_walk_iterator iterator; 34386e8eb206SDavid Matlack u64 old_spte; 34396e8eb206SDavid Matlack u64 *sptep = NULL; 34406e8eb206SDavid Matlack 34416e8eb206SDavid Matlack for_each_shadow_entry_lockless(vcpu, gpa, iterator, old_spte) { 34426e8eb206SDavid Matlack sptep = iterator.sptep; 34436e8eb206SDavid Matlack *spte = old_spte; 34446e8eb206SDavid Matlack } 34456e8eb206SDavid Matlack 34466e8eb206SDavid Matlack return sptep; 34476e8eb206SDavid Matlack } 34486e8eb206SDavid Matlack 34496e8eb206SDavid Matlack /* 3450c4371c2aSSean Christopherson * Returns one of RET_PF_INVALID, RET_PF_FIXED or RET_PF_SPURIOUS. 3451c50d8ae3SPaolo Bonzini */ 34523c8ad5a6SPaolo Bonzini static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 3453c50d8ae3SPaolo Bonzini { 3454c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3455c4371c2aSSean Christopherson int ret = RET_PF_INVALID; 3456c50d8ae3SPaolo Bonzini u64 spte = 0ull; 34576e8eb206SDavid Matlack u64 *sptep = NULL; 3458c50d8ae3SPaolo Bonzini uint retry_count = 0; 3459c50d8ae3SPaolo Bonzini 34603c8ad5a6SPaolo Bonzini if (!page_fault_can_be_fast(fault)) 3461c4371c2aSSean Christopherson return ret; 3462c50d8ae3SPaolo Bonzini 3463c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 3464c50d8ae3SPaolo Bonzini 3465c50d8ae3SPaolo Bonzini do { 3466c50d8ae3SPaolo Bonzini u64 new_spte; 3467c50d8ae3SPaolo Bonzini 3468dfe0ecc6SSean Christopherson if (tdp_mmu_enabled) 34693c8ad5a6SPaolo Bonzini sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 34706e8eb206SDavid Matlack else 34713c8ad5a6SPaolo Bonzini sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte); 3472c50d8ae3SPaolo Bonzini 3473ec89e643SSean Christopherson if (!is_shadow_present_pte(spte)) 3474ec89e643SSean Christopherson break; 3475ec89e643SSean Christopherson 34766e8eb206SDavid Matlack sp = sptep_to_sp(sptep); 3477c50d8ae3SPaolo Bonzini if (!is_last_spte(spte, sp->role.level)) 3478c50d8ae3SPaolo Bonzini break; 3479c50d8ae3SPaolo Bonzini 3480c50d8ae3SPaolo Bonzini /* 3481c50d8ae3SPaolo Bonzini * Check whether the memory access that caused the fault would 3482c50d8ae3SPaolo Bonzini * still cause it if it were to be performed right now. If not, 3483c50d8ae3SPaolo Bonzini * then this is a spurious fault caused by TLB lazily flushed, 3484c50d8ae3SPaolo Bonzini * or some other CPU has already fixed the PTE after the 3485c50d8ae3SPaolo Bonzini * current CPU took the fault. 3486c50d8ae3SPaolo Bonzini * 3487c50d8ae3SPaolo Bonzini * Need not check the access of upper level table entries since 3488c50d8ae3SPaolo Bonzini * they are always ACC_ALL. 3489c50d8ae3SPaolo Bonzini */ 34903c8ad5a6SPaolo Bonzini if (is_access_allowed(fault, spte)) { 3491c4371c2aSSean Christopherson ret = RET_PF_SPURIOUS; 3492c50d8ae3SPaolo Bonzini break; 3493c50d8ae3SPaolo Bonzini } 3494c50d8ae3SPaolo Bonzini 3495c50d8ae3SPaolo Bonzini new_spte = spte; 3496c50d8ae3SPaolo Bonzini 349754275f74SSean Christopherson /* 349854275f74SSean Christopherson * KVM only supports fixing page faults outside of MMU lock for 349954275f74SSean Christopherson * direct MMUs, nested MMUs are always indirect, and KVM always 350054275f74SSean Christopherson * uses A/D bits for non-nested MMUs. Thus, if A/D bits are 350154275f74SSean Christopherson * enabled, the SPTE can't be an access-tracked SPTE. 350254275f74SSean Christopherson */ 350354275f74SSean Christopherson if (unlikely(!kvm_ad_enabled()) && is_access_track_spte(spte)) 3504c50d8ae3SPaolo Bonzini new_spte = restore_acc_track_spte(new_spte); 3505c50d8ae3SPaolo Bonzini 3506c50d8ae3SPaolo Bonzini /* 350754275f74SSean Christopherson * To keep things simple, only SPTEs that are MMU-writable can 350854275f74SSean Christopherson * be made fully writable outside of mmu_lock, e.g. only SPTEs 350954275f74SSean Christopherson * that were write-protected for dirty-logging or access 351054275f74SSean Christopherson * tracking are handled here. Don't bother checking if the 351154275f74SSean Christopherson * SPTE is writable to prioritize running with A/D bits enabled. 351254275f74SSean Christopherson * The is_access_allowed() check above handles the common case 351354275f74SSean Christopherson * of the fault being spurious, and the SPTE is known to be 351454275f74SSean Christopherson * shadow-present, i.e. except for access tracking restoration 351554275f74SSean Christopherson * making the new SPTE writable, the check is wasteful. 3516c50d8ae3SPaolo Bonzini */ 3517706c9c55SSean Christopherson if (fault->write && is_mmu_writable_spte(spte)) { 3518c50d8ae3SPaolo Bonzini new_spte |= PT_WRITABLE_MASK; 3519c50d8ae3SPaolo Bonzini 3520c50d8ae3SPaolo Bonzini /* 352110c30de0SJunaid Shahid * Do not fix write-permission on the large spte when 352210c30de0SJunaid Shahid * dirty logging is enabled. Since we only dirty the 352310c30de0SJunaid Shahid * first page into the dirty-bitmap in 3524c50d8ae3SPaolo Bonzini * fast_pf_fix_direct_spte(), other pages are missed 3525c50d8ae3SPaolo Bonzini * if its slot has dirty logging enabled. 3526c50d8ae3SPaolo Bonzini * 3527c50d8ae3SPaolo Bonzini * Instead, we let the slow page fault path create a 3528c50d8ae3SPaolo Bonzini * normal spte to fix the access. 3529c50d8ae3SPaolo Bonzini */ 353010c30de0SJunaid Shahid if (sp->role.level > PG_LEVEL_4K && 353110c30de0SJunaid Shahid kvm_slot_dirty_track_enabled(fault->slot)) 3532c50d8ae3SPaolo Bonzini break; 3533c50d8ae3SPaolo Bonzini } 3534c50d8ae3SPaolo Bonzini 3535c50d8ae3SPaolo Bonzini /* Verify that the fault can be handled in the fast path */ 3536c50d8ae3SPaolo Bonzini if (new_spte == spte || 35373c8ad5a6SPaolo Bonzini !is_access_allowed(fault, new_spte)) 3538c50d8ae3SPaolo Bonzini break; 3539c50d8ae3SPaolo Bonzini 3540c50d8ae3SPaolo Bonzini /* 3541c50d8ae3SPaolo Bonzini * Currently, fast page fault only works for direct mapping 3542c50d8ae3SPaolo Bonzini * since the gfn is not stable for indirect shadow page. See 35433ecad8c2SMauro Carvalho Chehab * Documentation/virt/kvm/locking.rst to get more detail. 3544c50d8ae3SPaolo Bonzini */ 3545e710c5f6SDavid Matlack if (fast_pf_fix_direct_spte(vcpu, fault, sptep, spte, new_spte)) { 3546c4371c2aSSean Christopherson ret = RET_PF_FIXED; 3547c50d8ae3SPaolo Bonzini break; 3548c4371c2aSSean Christopherson } 3549c50d8ae3SPaolo Bonzini 3550c50d8ae3SPaolo Bonzini if (++retry_count > 4) { 35518d20bd63SSean Christopherson pr_warn_once("Fast #PF retrying more than 4 times.\n"); 3552c50d8ae3SPaolo Bonzini break; 3553c50d8ae3SPaolo Bonzini } 3554c50d8ae3SPaolo Bonzini 3555c50d8ae3SPaolo Bonzini } while (true); 3556c50d8ae3SPaolo Bonzini 3557f0066d94SPaolo Bonzini trace_fast_page_fault(vcpu, fault, sptep, spte, ret); 3558c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 3559c50d8ae3SPaolo Bonzini 35601075d41eSSean Christopherson if (ret != RET_PF_INVALID) 35611075d41eSSean Christopherson vcpu->stat.pf_fast++; 35621075d41eSSean Christopherson 3563c4371c2aSSean Christopherson return ret; 3564c50d8ae3SPaolo Bonzini } 3565c50d8ae3SPaolo Bonzini 3566c50d8ae3SPaolo Bonzini static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 3567c50d8ae3SPaolo Bonzini struct list_head *invalid_list) 3568c50d8ae3SPaolo Bonzini { 3569c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 3570c50d8ae3SPaolo Bonzini 3571c50d8ae3SPaolo Bonzini if (!VALID_PAGE(*root_hpa)) 3572c50d8ae3SPaolo Bonzini return; 3573c50d8ae3SPaolo Bonzini 35745e3edd7eSSean Christopherson /* 35755e3edd7eSSean Christopherson * The "root" may be a special root, e.g. a PAE entry, treat it as a 35765e3edd7eSSean Christopherson * SPTE to ensure any non-PA bits are dropped. 35775e3edd7eSSean Christopherson */ 35785e3edd7eSSean Christopherson sp = spte_to_child_sp(*root_hpa); 35799191b8f0SPaolo Bonzini if (WARN_ON(!sp)) 35809191b8f0SPaolo Bonzini return; 358102c00b3aSBen Gardon 3582897218ffSPaolo Bonzini if (is_tdp_mmu_page(sp)) 35836103bc07SBen Gardon kvm_tdp_mmu_put_root(kvm, sp, false); 358476eb54e7SBen Gardon else if (!--sp->root_count && sp->role.invalid) 3585c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); 3586c50d8ae3SPaolo Bonzini 3587c50d8ae3SPaolo Bonzini *root_hpa = INVALID_PAGE; 3588c50d8ae3SPaolo Bonzini } 3589c50d8ae3SPaolo Bonzini 3590c50d8ae3SPaolo Bonzini /* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ 35910c1c92f1SPaolo Bonzini void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, 3592c50d8ae3SPaolo Bonzini ulong roots_to_free) 3593c50d8ae3SPaolo Bonzini { 3594c50d8ae3SPaolo Bonzini int i; 3595c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 3596594bef79SPaolo Bonzini bool free_active_root; 3597c50d8ae3SPaolo Bonzini 3598f94db0c8SSean Christopherson WARN_ON_ONCE(roots_to_free & ~KVM_MMU_ROOTS_ALL); 3599f94db0c8SSean Christopherson 3600c50d8ae3SPaolo Bonzini BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); 3601c50d8ae3SPaolo Bonzini 3602c50d8ae3SPaolo Bonzini /* Before acquiring the MMU lock, see if we need to do any real work. */ 3603594bef79SPaolo Bonzini free_active_root = (roots_to_free & KVM_MMU_ROOT_CURRENT) 3604594bef79SPaolo Bonzini && VALID_PAGE(mmu->root.hpa); 3605594bef79SPaolo Bonzini 3606594bef79SPaolo Bonzini if (!free_active_root) { 3607c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3608c50d8ae3SPaolo Bonzini if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && 3609c50d8ae3SPaolo Bonzini VALID_PAGE(mmu->prev_roots[i].hpa)) 3610c50d8ae3SPaolo Bonzini break; 3611c50d8ae3SPaolo Bonzini 3612c50d8ae3SPaolo Bonzini if (i == KVM_MMU_NUM_PREV_ROOTS) 3613c50d8ae3SPaolo Bonzini return; 3614c50d8ae3SPaolo Bonzini } 3615c50d8ae3SPaolo Bonzini 3616531810caSBen Gardon write_lock(&kvm->mmu_lock); 3617c50d8ae3SPaolo Bonzini 3618c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 3619c50d8ae3SPaolo Bonzini if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) 36204d710de9SSean Christopherson mmu_free_root_page(kvm, &mmu->prev_roots[i].hpa, 3621c50d8ae3SPaolo Bonzini &invalid_list); 3622c50d8ae3SPaolo Bonzini 3623c50d8ae3SPaolo Bonzini if (free_active_root) { 3624594bef79SPaolo Bonzini if (to_shadow_page(mmu->root.hpa)) { 3625b9e5603cSPaolo Bonzini mmu_free_root_page(kvm, &mmu->root.hpa, &invalid_list); 362604d45551SSean Christopherson } else if (mmu->pae_root) { 3627c834e5e4SSean Christopherson for (i = 0; i < 4; ++i) { 3628c834e5e4SSean Christopherson if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) 3629c834e5e4SSean Christopherson continue; 3630c834e5e4SSean Christopherson 3631c834e5e4SSean Christopherson mmu_free_root_page(kvm, &mmu->pae_root[i], 3632c50d8ae3SPaolo Bonzini &invalid_list); 3633c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3634c50d8ae3SPaolo Bonzini } 3635c50d8ae3SPaolo Bonzini } 3636b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 3637b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 3638c50d8ae3SPaolo Bonzini } 3639c50d8ae3SPaolo Bonzini 36404d710de9SSean Christopherson kvm_mmu_commit_zap_page(kvm, &invalid_list); 3641531810caSBen Gardon write_unlock(&kvm->mmu_lock); 3642c50d8ae3SPaolo Bonzini } 3643c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_free_roots); 3644c50d8ae3SPaolo Bonzini 36450c1c92f1SPaolo Bonzini void kvm_mmu_free_guest_mode_roots(struct kvm *kvm, struct kvm_mmu *mmu) 364625b62c62SSean Christopherson { 364725b62c62SSean Christopherson unsigned long roots_to_free = 0; 364825b62c62SSean Christopherson hpa_t root_hpa; 364925b62c62SSean Christopherson int i; 365025b62c62SSean Christopherson 365125b62c62SSean Christopherson /* 365225b62c62SSean Christopherson * This should not be called while L2 is active, L2 can't invalidate 365325b62c62SSean Christopherson * _only_ its own roots, e.g. INVVPID unconditionally exits. 365425b62c62SSean Christopherson */ 36557a458f0eSPaolo Bonzini WARN_ON_ONCE(mmu->root_role.guest_mode); 365625b62c62SSean Christopherson 365725b62c62SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 365825b62c62SSean Christopherson root_hpa = mmu->prev_roots[i].hpa; 365925b62c62SSean Christopherson if (!VALID_PAGE(root_hpa)) 366025b62c62SSean Christopherson continue; 366125b62c62SSean Christopherson 366225b62c62SSean Christopherson if (!to_shadow_page(root_hpa) || 366325b62c62SSean Christopherson to_shadow_page(root_hpa)->role.guest_mode) 366425b62c62SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 366525b62c62SSean Christopherson } 366625b62c62SSean Christopherson 36670c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, roots_to_free); 366825b62c62SSean Christopherson } 366925b62c62SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_free_guest_mode_roots); 367025b62c62SSean Christopherson 367125b62c62SSean Christopherson 3672c50d8ae3SPaolo Bonzini static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 3673c50d8ae3SPaolo Bonzini { 3674c50d8ae3SPaolo Bonzini int ret = 0; 3675c50d8ae3SPaolo Bonzini 3676995decb6SVitaly Kuznetsov if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) { 3677c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); 3678c50d8ae3SPaolo Bonzini ret = 1; 3679c50d8ae3SPaolo Bonzini } 3680c50d8ae3SPaolo Bonzini 3681c50d8ae3SPaolo Bonzini return ret; 3682c50d8ae3SPaolo Bonzini } 3683c50d8ae3SPaolo Bonzini 36842e65e842SDavid Matlack static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, int quadrant, 368586938ab6SDavid Matlack u8 level) 3686c50d8ae3SPaolo Bonzini { 36872e65e842SDavid Matlack union kvm_mmu_page_role role = vcpu->arch.mmu->root_role; 3688c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 36898123f265SSean Christopherson 36902e65e842SDavid Matlack role.level = level; 36912e65e842SDavid Matlack role.quadrant = quadrant; 36922e65e842SDavid Matlack 36937f497775SDavid Matlack WARN_ON_ONCE(quadrant && !role.has_4_byte_gpte); 36947f497775SDavid Matlack WARN_ON_ONCE(role.direct && role.has_4_byte_gpte); 36957f497775SDavid Matlack 369687654643SDavid Matlack sp = kvm_mmu_get_shadow_page(vcpu, gfn, role); 36978123f265SSean Christopherson ++sp->root_count; 36988123f265SSean Christopherson 36998123f265SSean Christopherson return __pa(sp->spt); 37008123f265SSean Christopherson } 37018123f265SSean Christopherson 37028123f265SSean Christopherson static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 37038123f265SSean Christopherson { 3704b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3705a972e29cSPaolo Bonzini u8 shadow_root_level = mmu->root_role.level; 37068123f265SSean Christopherson hpa_t root; 3707c50d8ae3SPaolo Bonzini unsigned i; 37084a38162eSPaolo Bonzini int r; 37094a38162eSPaolo Bonzini 37104a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 37114a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 37124a38162eSPaolo Bonzini if (r < 0) 37134a38162eSPaolo Bonzini goto out_unlock; 3714c50d8ae3SPaolo Bonzini 37151f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 371602c00b3aSBen Gardon root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); 3717b9e5603cSPaolo Bonzini mmu->root.hpa = root; 371802c00b3aSBen Gardon } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { 371986938ab6SDavid Matlack root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level); 3720b9e5603cSPaolo Bonzini mmu->root.hpa = root; 37218123f265SSean Christopherson } else if (shadow_root_level == PT32E_ROOT_LEVEL) { 37224a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 37234a38162eSPaolo Bonzini r = -EIO; 37244a38162eSPaolo Bonzini goto out_unlock; 37254a38162eSPaolo Bonzini } 372673ad1606SSean Christopherson 3727c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3728c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 3729c50d8ae3SPaolo Bonzini 37307f497775SDavid Matlack root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), 0, 37312e65e842SDavid Matlack PT32_ROOT_LEVEL); 373217e368d9SSean Christopherson mmu->pae_root[i] = root | PT_PRESENT_MASK | 3733d2263de1SYuan Yao shadow_me_value; 3734c50d8ae3SPaolo Bonzini } 3735b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 373673ad1606SSean Christopherson } else { 373773ad1606SSean Christopherson WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); 37384a38162eSPaolo Bonzini r = -EIO; 37394a38162eSPaolo Bonzini goto out_unlock; 374073ad1606SSean Christopherson } 37413651c7fcSSean Christopherson 3742b9e5603cSPaolo Bonzini /* root.pgd is ignored for direct MMUs. */ 3743b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 37444a38162eSPaolo Bonzini out_unlock: 37454a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 37464a38162eSPaolo Bonzini return r; 3747c50d8ae3SPaolo Bonzini } 3748c50d8ae3SPaolo Bonzini 37491e76a3ceSDavid Stevens static int mmu_first_shadow_root_alloc(struct kvm *kvm) 37501e76a3ceSDavid Stevens { 37511e76a3ceSDavid Stevens struct kvm_memslots *slots; 37521e76a3ceSDavid Stevens struct kvm_memory_slot *slot; 3753a54d8066SMaciej S. Szmigiero int r = 0, i, bkt; 37541e76a3ceSDavid Stevens 37551e76a3ceSDavid Stevens /* 37561e76a3ceSDavid Stevens * Check if this is the first shadow root being allocated before 37571e76a3ceSDavid Stevens * taking the lock. 37581e76a3ceSDavid Stevens */ 37591e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37601e76a3ceSDavid Stevens return 0; 37611e76a3ceSDavid Stevens 37621e76a3ceSDavid Stevens mutex_lock(&kvm->slots_arch_lock); 37631e76a3ceSDavid Stevens 37641e76a3ceSDavid Stevens /* Recheck, under the lock, whether this is the first shadow root. */ 37651e76a3ceSDavid Stevens if (kvm_shadow_root_allocated(kvm)) 37661e76a3ceSDavid Stevens goto out_unlock; 37671e76a3ceSDavid Stevens 37681e76a3ceSDavid Stevens /* 37691e76a3ceSDavid Stevens * Check if anything actually needs to be allocated, e.g. all metadata 37701e76a3ceSDavid Stevens * will be allocated upfront if TDP is disabled. 37711e76a3ceSDavid Stevens */ 37721e76a3ceSDavid Stevens if (kvm_memslots_have_rmaps(kvm) && 37731e76a3ceSDavid Stevens kvm_page_track_write_tracking_enabled(kvm)) 37741e76a3ceSDavid Stevens goto out_success; 37751e76a3ceSDavid Stevens 37761e76a3ceSDavid Stevens for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 37771e76a3ceSDavid Stevens slots = __kvm_memslots(kvm, i); 3778a54d8066SMaciej S. Szmigiero kvm_for_each_memslot(slot, bkt, slots) { 37791e76a3ceSDavid Stevens /* 37801e76a3ceSDavid Stevens * Both of these functions are no-ops if the target is 37811e76a3ceSDavid Stevens * already allocated, so unconditionally calling both 37821e76a3ceSDavid Stevens * is safe. Intentionally do NOT free allocations on 37831e76a3ceSDavid Stevens * failure to avoid having to track which allocations 37841e76a3ceSDavid Stevens * were made now versus when the memslot was created. 37851e76a3ceSDavid Stevens * The metadata is guaranteed to be freed when the slot 37861e76a3ceSDavid Stevens * is freed, and will be kept/used if userspace retries 37871e76a3ceSDavid Stevens * KVM_RUN instead of killing the VM. 37881e76a3ceSDavid Stevens */ 37891e76a3ceSDavid Stevens r = memslot_rmap_alloc(slot, slot->npages); 37901e76a3ceSDavid Stevens if (r) 37911e76a3ceSDavid Stevens goto out_unlock; 37921e76a3ceSDavid Stevens r = kvm_page_track_write_tracking_alloc(slot); 37931e76a3ceSDavid Stevens if (r) 37941e76a3ceSDavid Stevens goto out_unlock; 37951e76a3ceSDavid Stevens } 37961e76a3ceSDavid Stevens } 37971e76a3ceSDavid Stevens 37981e76a3ceSDavid Stevens /* 37991e76a3ceSDavid Stevens * Ensure that shadow_root_allocated becomes true strictly after 38001e76a3ceSDavid Stevens * all the related pointers are set. 38011e76a3ceSDavid Stevens */ 38021e76a3ceSDavid Stevens out_success: 38031e76a3ceSDavid Stevens smp_store_release(&kvm->arch.shadow_root_allocated, true); 38041e76a3ceSDavid Stevens 38051e76a3ceSDavid Stevens out_unlock: 38061e76a3ceSDavid Stevens mutex_unlock(&kvm->slots_arch_lock); 38071e76a3ceSDavid Stevens return r; 38081e76a3ceSDavid Stevens } 38091e76a3ceSDavid Stevens 3810c50d8ae3SPaolo Bonzini static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 3811c50d8ae3SPaolo Bonzini { 3812b37233c9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 38136e0918aeSSean Christopherson u64 pdptrs[4], pm_mask; 3814be01e8e2SSean Christopherson gfn_t root_gfn, root_pgd; 38157f497775SDavid Matlack int quadrant, i, r; 38168123f265SSean Christopherson hpa_t root; 3817c50d8ae3SPaolo Bonzini 3818*2fdcc1b3SPaolo Bonzini root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu); 3819be01e8e2SSean Christopherson root_gfn = root_pgd >> PAGE_SHIFT; 3820c50d8ae3SPaolo Bonzini 3821c50d8ae3SPaolo Bonzini if (mmu_check_root(vcpu, root_gfn)) 3822c50d8ae3SPaolo Bonzini return 1; 3823c50d8ae3SPaolo Bonzini 3824c50d8ae3SPaolo Bonzini /* 38254a38162eSPaolo Bonzini * On SVM, reading PDPTRs might access guest memory, which might fault 38264a38162eSPaolo Bonzini * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. 38274a38162eSPaolo Bonzini */ 38284d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38296e0918aeSSean Christopherson for (i = 0; i < 4; ++i) { 38306e0918aeSSean Christopherson pdptrs[i] = mmu->get_pdptr(vcpu, i); 38316e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) 38326e0918aeSSean Christopherson continue; 38336e0918aeSSean Christopherson 38346e0918aeSSean Christopherson if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) 38356e0918aeSSean Christopherson return 1; 38366e0918aeSSean Christopherson } 38376e0918aeSSean Christopherson } 38386e0918aeSSean Christopherson 38391e76a3ceSDavid Stevens r = mmu_first_shadow_root_alloc(vcpu->kvm); 3840d501f747SBen Gardon if (r) 3841d501f747SBen Gardon return r; 3842d501f747SBen Gardon 38434a38162eSPaolo Bonzini write_lock(&vcpu->kvm->mmu_lock); 38444a38162eSPaolo Bonzini r = make_mmu_pages_available(vcpu); 38454a38162eSPaolo Bonzini if (r < 0) 38464a38162eSPaolo Bonzini goto out_unlock; 38474a38162eSPaolo Bonzini 3848c50d8ae3SPaolo Bonzini /* 3849c50d8ae3SPaolo Bonzini * Do we shadow a long mode page table? If so we need to 3850c50d8ae3SPaolo Bonzini * write-protect the guests page table root. 3851c50d8ae3SPaolo Bonzini */ 38524d25502aSPaolo Bonzini if (mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 38538123f265SSean Christopherson root = mmu_alloc_root(vcpu, root_gfn, 0, 385486938ab6SDavid Matlack mmu->root_role.level); 3855b9e5603cSPaolo Bonzini mmu->root.hpa = root; 3856be01e8e2SSean Christopherson goto set_root_pgd; 3857c50d8ae3SPaolo Bonzini } 3858c50d8ae3SPaolo Bonzini 38594a38162eSPaolo Bonzini if (WARN_ON_ONCE(!mmu->pae_root)) { 38604a38162eSPaolo Bonzini r = -EIO; 38614a38162eSPaolo Bonzini goto out_unlock; 38624a38162eSPaolo Bonzini } 386373ad1606SSean Christopherson 3864c50d8ae3SPaolo Bonzini /* 3865c50d8ae3SPaolo Bonzini * We shadow a 32 bit page table. This may be a legacy 2-level 3866c50d8ae3SPaolo Bonzini * or a PAE 3-level page table. In either case we need to be aware that 3867c50d8ae3SPaolo Bonzini * the shadow page table may be a PAE or a long mode page table. 3868c50d8ae3SPaolo Bonzini */ 3869e54f1ff2SKai Huang pm_mask = PT_PRESENT_MASK | shadow_me_value; 3870a972e29cSPaolo Bonzini if (mmu->root_role.level >= PT64_ROOT_4LEVEL) { 3871c50d8ae3SPaolo Bonzini pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; 3872c50d8ae3SPaolo Bonzini 387303ca4589SSean Christopherson if (WARN_ON_ONCE(!mmu->pml4_root)) { 38744a38162eSPaolo Bonzini r = -EIO; 38754a38162eSPaolo Bonzini goto out_unlock; 38764a38162eSPaolo Bonzini } 387703ca4589SSean Christopherson mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; 3878cb0f722aSWei Huang 3879a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) { 3880cb0f722aSWei Huang if (WARN_ON_ONCE(!mmu->pml5_root)) { 3881cb0f722aSWei Huang r = -EIO; 3882cb0f722aSWei Huang goto out_unlock; 3883cb0f722aSWei Huang } 3884cb0f722aSWei Huang mmu->pml5_root[0] = __pa(mmu->pml4_root) | pm_mask; 3885cb0f722aSWei Huang } 388604d45551SSean Christopherson } 388704d45551SSean Christopherson 3888c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 3889c834e5e4SSean Christopherson WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); 38906e6ec584SSean Christopherson 38914d25502aSPaolo Bonzini if (mmu->cpu_role.base.level == PT32E_ROOT_LEVEL) { 38926e0918aeSSean Christopherson if (!(pdptrs[i] & PT_PRESENT_MASK)) { 3893c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 3894c50d8ae3SPaolo Bonzini continue; 3895c50d8ae3SPaolo Bonzini } 38966e0918aeSSean Christopherson root_gfn = pdptrs[i] >> PAGE_SHIFT; 3897c50d8ae3SPaolo Bonzini } 3898c50d8ae3SPaolo Bonzini 38997f497775SDavid Matlack /* 39007f497775SDavid Matlack * If shadowing 32-bit non-PAE page tables, each PAE page 39017f497775SDavid Matlack * directory maps one quarter of the guest's non-PAE page 39027f497775SDavid Matlack * directory. Othwerise each PAE page direct shadows one guest 39037f497775SDavid Matlack * PAE page directory so that quadrant should be 0. 39047f497775SDavid Matlack */ 39057f497775SDavid Matlack quadrant = (mmu->cpu_role.base.level == PT32_ROOT_LEVEL) ? i : 0; 39067f497775SDavid Matlack 39077f497775SDavid Matlack root = mmu_alloc_root(vcpu, root_gfn, quadrant, PT32_ROOT_LEVEL); 3908b37233c9SSean Christopherson mmu->pae_root[i] = root | pm_mask; 3909c50d8ae3SPaolo Bonzini } 3910c50d8ae3SPaolo Bonzini 3911a972e29cSPaolo Bonzini if (mmu->root_role.level == PT64_ROOT_5LEVEL) 3912b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml5_root); 3913a972e29cSPaolo Bonzini else if (mmu->root_role.level == PT64_ROOT_4LEVEL) 3914b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pml4_root); 3915ba0a194fSSean Christopherson else 3916b9e5603cSPaolo Bonzini mmu->root.hpa = __pa(mmu->pae_root); 3917c50d8ae3SPaolo Bonzini 3918be01e8e2SSean Christopherson set_root_pgd: 3919b9e5603cSPaolo Bonzini mmu->root.pgd = root_pgd; 39204a38162eSPaolo Bonzini out_unlock: 39214a38162eSPaolo Bonzini write_unlock(&vcpu->kvm->mmu_lock); 3922c50d8ae3SPaolo Bonzini 3923c6c937d6SLike Xu return r; 3924c50d8ae3SPaolo Bonzini } 3925c50d8ae3SPaolo Bonzini 3926748e52b9SSean Christopherson static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) 3927c50d8ae3SPaolo Bonzini { 3928748e52b9SSean Christopherson struct kvm_mmu *mmu = vcpu->arch.mmu; 3929a972e29cSPaolo Bonzini bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL; 3930cb0f722aSWei Huang u64 *pml5_root = NULL; 3931cb0f722aSWei Huang u64 *pml4_root = NULL; 3932cb0f722aSWei Huang u64 *pae_root; 3933748e52b9SSean Christopherson 3934748e52b9SSean Christopherson /* 3935748e52b9SSean Christopherson * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP 3936748e52b9SSean Christopherson * tables are allocated and initialized at root creation as there is no 3937748e52b9SSean Christopherson * equivalent level in the guest's NPT to shadow. Allocate the tables 3938748e52b9SSean Christopherson * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. 3939748e52b9SSean Christopherson */ 3940347a0d0dSPaolo Bonzini if (mmu->root_role.direct || 3941347a0d0dSPaolo Bonzini mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL || 3942a972e29cSPaolo Bonzini mmu->root_role.level < PT64_ROOT_4LEVEL) 3943748e52b9SSean Christopherson return 0; 3944748e52b9SSean Christopherson 3945a717a780SSean Christopherson /* 3946a717a780SSean Christopherson * NPT, the only paging mode that uses this horror, uses a fixed number 3947a717a780SSean Christopherson * of levels for the shadow page tables, e.g. all MMUs are 4-level or 3948a717a780SSean Christopherson * all MMus are 5-level. Thus, this can safely require that pml5_root 3949a717a780SSean Christopherson * is allocated if the other roots are valid and pml5 is needed, as any 3950a717a780SSean Christopherson * prior MMU would also have required pml5. 3951a717a780SSean Christopherson */ 3952a717a780SSean Christopherson if (mmu->pae_root && mmu->pml4_root && (!need_pml5 || mmu->pml5_root)) 3953748e52b9SSean Christopherson return 0; 3954748e52b9SSean Christopherson 3955748e52b9SSean Christopherson /* 3956748e52b9SSean Christopherson * The special roots should always be allocated in concert. Yell and 3957748e52b9SSean Christopherson * bail if KVM ends up in a state where only one of the roots is valid. 3958748e52b9SSean Christopherson */ 3959cb0f722aSWei Huang if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root || 3960a717a780SSean Christopherson (need_pml5 && mmu->pml5_root))) 3961748e52b9SSean Christopherson return -EIO; 3962748e52b9SSean Christopherson 39634a98623dSSean Christopherson /* 39644a98623dSSean Christopherson * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and 39654a98623dSSean Christopherson * doesn't need to be decrypted. 39664a98623dSSean Christopherson */ 3967748e52b9SSean Christopherson pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3968748e52b9SSean Christopherson if (!pae_root) 3969748e52b9SSean Christopherson return -ENOMEM; 3970748e52b9SSean Christopherson 3971cb0f722aSWei Huang #ifdef CONFIG_X86_64 397203ca4589SSean Christopherson pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3973cb0f722aSWei Huang if (!pml4_root) 3974cb0f722aSWei Huang goto err_pml4; 3975cb0f722aSWei Huang 3976a717a780SSean Christopherson if (need_pml5) { 3977cb0f722aSWei Huang pml5_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); 3978cb0f722aSWei Huang if (!pml5_root) 3979cb0f722aSWei Huang goto err_pml5; 3980748e52b9SSean Christopherson } 3981cb0f722aSWei Huang #endif 3982748e52b9SSean Christopherson 3983748e52b9SSean Christopherson mmu->pae_root = pae_root; 398403ca4589SSean Christopherson mmu->pml4_root = pml4_root; 3985cb0f722aSWei Huang mmu->pml5_root = pml5_root; 3986748e52b9SSean Christopherson 3987748e52b9SSean Christopherson return 0; 3988cb0f722aSWei Huang 3989cb0f722aSWei Huang #ifdef CONFIG_X86_64 3990cb0f722aSWei Huang err_pml5: 3991cb0f722aSWei Huang free_page((unsigned long)pml4_root); 3992cb0f722aSWei Huang err_pml4: 3993cb0f722aSWei Huang free_page((unsigned long)pae_root); 3994cb0f722aSWei Huang return -ENOMEM; 3995cb0f722aSWei Huang #endif 3996c50d8ae3SPaolo Bonzini } 3997c50d8ae3SPaolo Bonzini 3998264d3dc1SLai Jiangshan static bool is_unsync_root(hpa_t root) 3999264d3dc1SLai Jiangshan { 4000264d3dc1SLai Jiangshan struct kvm_mmu_page *sp; 4001264d3dc1SLai Jiangshan 400261b05a9fSLai Jiangshan if (!VALID_PAGE(root)) 400361b05a9fSLai Jiangshan return false; 400461b05a9fSLai Jiangshan 4005264d3dc1SLai Jiangshan /* 4006264d3dc1SLai Jiangshan * The read barrier orders the CPU's read of SPTE.W during the page table 4007264d3dc1SLai Jiangshan * walk before the reads of sp->unsync/sp->unsync_children here. 4008264d3dc1SLai Jiangshan * 4009264d3dc1SLai Jiangshan * Even if another CPU was marking the SP as unsync-ed simultaneously, 4010264d3dc1SLai Jiangshan * any guest page table changes are not guaranteed to be visible anyway 4011264d3dc1SLai Jiangshan * until this VCPU issues a TLB flush strictly after those changes are 4012264d3dc1SLai Jiangshan * made. We only need to ensure that the other CPU sets these flags 4013264d3dc1SLai Jiangshan * before any actual changes to the page tables are made. The comments 4014264d3dc1SLai Jiangshan * in mmu_try_to_unsync_pages() describe what could go wrong if this 4015264d3dc1SLai Jiangshan * requirement isn't satisfied. 4016264d3dc1SLai Jiangshan */ 4017264d3dc1SLai Jiangshan smp_rmb(); 4018264d3dc1SLai Jiangshan sp = to_shadow_page(root); 40195d6a3221SSean Christopherson 40205d6a3221SSean Christopherson /* 40215d6a3221SSean Christopherson * PAE roots (somewhat arbitrarily) aren't backed by shadow pages, the 40225d6a3221SSean Christopherson * PDPTEs for a given PAE root need to be synchronized individually. 40235d6a3221SSean Christopherson */ 40245d6a3221SSean Christopherson if (WARN_ON_ONCE(!sp)) 40255d6a3221SSean Christopherson return false; 40265d6a3221SSean Christopherson 4027264d3dc1SLai Jiangshan if (sp->unsync || sp->unsync_children) 4028264d3dc1SLai Jiangshan return true; 4029264d3dc1SLai Jiangshan 4030264d3dc1SLai Jiangshan return false; 4031264d3dc1SLai Jiangshan } 4032264d3dc1SLai Jiangshan 4033c50d8ae3SPaolo Bonzini void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) 4034c50d8ae3SPaolo Bonzini { 4035c50d8ae3SPaolo Bonzini int i; 4036c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 4037c50d8ae3SPaolo Bonzini 4038347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 4039c50d8ae3SPaolo Bonzini return; 4040c50d8ae3SPaolo Bonzini 4041b9e5603cSPaolo Bonzini if (!VALID_PAGE(vcpu->arch.mmu->root.hpa)) 4042c50d8ae3SPaolo Bonzini return; 4043c50d8ae3SPaolo Bonzini 4044c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4045c50d8ae3SPaolo Bonzini 40464d25502aSPaolo Bonzini if (vcpu->arch.mmu->cpu_role.base.level >= PT64_ROOT_4LEVEL) { 4047b9e5603cSPaolo Bonzini hpa_t root = vcpu->arch.mmu->root.hpa; 4048e47c4aeeSSean Christopherson sp = to_shadow_page(root); 4049c50d8ae3SPaolo Bonzini 4050264d3dc1SLai Jiangshan if (!is_unsync_root(root)) 4051c50d8ae3SPaolo Bonzini return; 4052c50d8ae3SPaolo Bonzini 4053531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 405465855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4055531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4056c50d8ae3SPaolo Bonzini return; 4057c50d8ae3SPaolo Bonzini } 4058c50d8ae3SPaolo Bonzini 4059531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4060c50d8ae3SPaolo Bonzini 4061c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) { 4062c50d8ae3SPaolo Bonzini hpa_t root = vcpu->arch.mmu->pae_root[i]; 4063c50d8ae3SPaolo Bonzini 4064c834e5e4SSean Christopherson if (IS_VALID_PAE_ROOT(root)) { 40655e3edd7eSSean Christopherson sp = spte_to_child_sp(root); 406665855ed8SLai Jiangshan mmu_sync_children(vcpu, sp, true); 4067c50d8ae3SPaolo Bonzini } 4068c50d8ae3SPaolo Bonzini } 4069c50d8ae3SPaolo Bonzini 4070531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 4071c50d8ae3SPaolo Bonzini } 4072c50d8ae3SPaolo Bonzini 407361b05a9fSLai Jiangshan void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu) 407461b05a9fSLai Jiangshan { 407561b05a9fSLai Jiangshan unsigned long roots_to_free = 0; 407661b05a9fSLai Jiangshan int i; 407761b05a9fSLai Jiangshan 407861b05a9fSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 407961b05a9fSLai Jiangshan if (is_unsync_root(vcpu->arch.mmu->prev_roots[i].hpa)) 408061b05a9fSLai Jiangshan roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 408161b05a9fSLai Jiangshan 408261b05a9fSLai Jiangshan /* sync prev_roots by simply freeing them */ 40830c1c92f1SPaolo Bonzini kvm_mmu_free_roots(vcpu->kvm, vcpu->arch.mmu, roots_to_free); 408461b05a9fSLai Jiangshan } 408561b05a9fSLai Jiangshan 40861f5a21eeSLai Jiangshan static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 40875b22bbe7SLai Jiangshan gpa_t vaddr, u64 access, 4088c50d8ae3SPaolo Bonzini struct x86_exception *exception) 4089c50d8ae3SPaolo Bonzini { 4090c50d8ae3SPaolo Bonzini if (exception) 4091c50d8ae3SPaolo Bonzini exception->error_code = 0; 4092c59a0f57SLai Jiangshan return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception); 4093c50d8ae3SPaolo Bonzini } 4094c50d8ae3SPaolo Bonzini 4095c50d8ae3SPaolo Bonzini static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4096c50d8ae3SPaolo Bonzini { 4097c50d8ae3SPaolo Bonzini /* 4098c50d8ae3SPaolo Bonzini * A nested guest cannot use the MMIO cache if it is using nested 4099c50d8ae3SPaolo Bonzini * page tables, because cr2 is a nGPA while the cache stores GPAs. 4100c50d8ae3SPaolo Bonzini */ 4101c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 4102c50d8ae3SPaolo Bonzini return false; 4103c50d8ae3SPaolo Bonzini 4104c50d8ae3SPaolo Bonzini if (direct) 4105c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gpa(vcpu, addr); 4106c50d8ae3SPaolo Bonzini 4107c50d8ae3SPaolo Bonzini return vcpu_match_mmio_gva(vcpu, addr); 4108c50d8ae3SPaolo Bonzini } 4109c50d8ae3SPaolo Bonzini 411095fb5b02SBen Gardon /* 411195fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 411295fb5b02SBen Gardon * That SPTE may be non-present. 4113c5c8c7c5SDavid Matlack * 4114c5c8c7c5SDavid Matlack * Must be called between walk_shadow_page_lockless_{begin,end}. 411595fb5b02SBen Gardon */ 411639b4d43eSSean Christopherson static int get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level) 4117c50d8ae3SPaolo Bonzini { 4118c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 41192aa07893SSean Christopherson int leaf = -1; 412095fb5b02SBen Gardon u64 spte; 4121c50d8ae3SPaolo Bonzini 412239b4d43eSSean Christopherson for (shadow_walk_init(&iterator, vcpu, addr), 412339b4d43eSSean Christopherson *root_level = iterator.level; 4124c50d8ae3SPaolo Bonzini shadow_walk_okay(&iterator); 4125c50d8ae3SPaolo Bonzini __shadow_walk_next(&iterator, spte)) { 412695fb5b02SBen Gardon leaf = iterator.level; 4127c50d8ae3SPaolo Bonzini spte = mmu_spte_get_lockless(iterator.sptep); 4128c50d8ae3SPaolo Bonzini 4129dde81f94SSean Christopherson sptes[leaf] = spte; 413095fb5b02SBen Gardon } 413195fb5b02SBen Gardon 413295fb5b02SBen Gardon return leaf; 413395fb5b02SBen Gardon } 413495fb5b02SBen Gardon 41359aa41879SSean Christopherson /* return true if reserved bit(s) are detected on a valid, non-MMIO SPTE. */ 413695fb5b02SBen Gardon static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) 413795fb5b02SBen Gardon { 4138dde81f94SSean Christopherson u64 sptes[PT64_ROOT_MAX_LEVEL + 1]; 413995fb5b02SBen Gardon struct rsvd_bits_validate *rsvd_check; 414039b4d43eSSean Christopherson int root, leaf, level; 414195fb5b02SBen Gardon bool reserved = false; 414295fb5b02SBen Gardon 4143c5c8c7c5SDavid Matlack walk_shadow_page_lockless_begin(vcpu); 4144c5c8c7c5SDavid Matlack 414578fdd2f0SSean Christopherson if (is_tdp_mmu_active(vcpu)) 414639b4d43eSSean Christopherson leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root); 414795fb5b02SBen Gardon else 414839b4d43eSSean Christopherson leaf = get_walk(vcpu, addr, sptes, &root); 414995fb5b02SBen Gardon 4150c5c8c7c5SDavid Matlack walk_shadow_page_lockless_end(vcpu); 4151c5c8c7c5SDavid Matlack 41522aa07893SSean Christopherson if (unlikely(leaf < 0)) { 41532aa07893SSean Christopherson *sptep = 0ull; 41542aa07893SSean Christopherson return reserved; 41552aa07893SSean Christopherson } 41562aa07893SSean Christopherson 41579aa41879SSean Christopherson *sptep = sptes[leaf]; 41589aa41879SSean Christopherson 41599aa41879SSean Christopherson /* 41609aa41879SSean Christopherson * Skip reserved bits checks on the terminal leaf if it's not a valid 41619aa41879SSean Christopherson * SPTE. Note, this also (intentionally) skips MMIO SPTEs, which, by 41629aa41879SSean Christopherson * design, always have reserved bits set. The purpose of the checks is 41639aa41879SSean Christopherson * to detect reserved bits on non-MMIO SPTEs. i.e. buggy SPTEs. 41649aa41879SSean Christopherson */ 41659aa41879SSean Christopherson if (!is_shadow_present_pte(sptes[leaf])) 41669aa41879SSean Christopherson leaf++; 416795fb5b02SBen Gardon 416895fb5b02SBen Gardon rsvd_check = &vcpu->arch.mmu->shadow_zero_check; 416995fb5b02SBen Gardon 41709aa41879SSean Christopherson for (level = root; level >= leaf; level--) 4171961f8445SSean Christopherson reserved |= is_rsvd_spte(rsvd_check, sptes[level], level); 4172c50d8ae3SPaolo Bonzini 4173c50d8ae3SPaolo Bonzini if (reserved) { 4174bb4cdf3aSSean Christopherson pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", 4175c50d8ae3SPaolo Bonzini __func__, addr); 417695fb5b02SBen Gardon for (level = root; level >= leaf; level--) 4177bb4cdf3aSSean Christopherson pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", 4178bb4cdf3aSSean Christopherson sptes[level], level, 4179961f8445SSean Christopherson get_rsvd_bits(rsvd_check, sptes[level], level)); 4180c50d8ae3SPaolo Bonzini } 4181ddce6208SSean Christopherson 4182c50d8ae3SPaolo Bonzini return reserved; 4183c50d8ae3SPaolo Bonzini } 4184c50d8ae3SPaolo Bonzini 4185c50d8ae3SPaolo Bonzini static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) 4186c50d8ae3SPaolo Bonzini { 4187c50d8ae3SPaolo Bonzini u64 spte; 4188c50d8ae3SPaolo Bonzini bool reserved; 4189c50d8ae3SPaolo Bonzini 4190c50d8ae3SPaolo Bonzini if (mmio_info_in_cache(vcpu, addr, direct)) 4191c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4192c50d8ae3SPaolo Bonzini 419395fb5b02SBen Gardon reserved = get_mmio_spte(vcpu, addr, &spte); 4194c50d8ae3SPaolo Bonzini if (WARN_ON(reserved)) 4195c50d8ae3SPaolo Bonzini return -EINVAL; 4196c50d8ae3SPaolo Bonzini 4197c50d8ae3SPaolo Bonzini if (is_mmio_spte(spte)) { 4198c50d8ae3SPaolo Bonzini gfn_t gfn = get_mmio_spte_gfn(spte); 41990a2b64c5SBen Gardon unsigned int access = get_mmio_spte_access(spte); 4200c50d8ae3SPaolo Bonzini 4201c50d8ae3SPaolo Bonzini if (!check_mmio_spte(vcpu, spte)) 4202c50d8ae3SPaolo Bonzini return RET_PF_INVALID; 4203c50d8ae3SPaolo Bonzini 4204c50d8ae3SPaolo Bonzini if (direct) 4205c50d8ae3SPaolo Bonzini addr = 0; 4206c50d8ae3SPaolo Bonzini 4207c50d8ae3SPaolo Bonzini trace_handle_mmio_page_fault(addr, gfn, access); 4208c50d8ae3SPaolo Bonzini vcpu_cache_mmio_info(vcpu, addr, gfn, access); 4209c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4210c50d8ae3SPaolo Bonzini } 4211c50d8ae3SPaolo Bonzini 4212c50d8ae3SPaolo Bonzini /* 4213c50d8ae3SPaolo Bonzini * If the page table is zapped by other cpus, let CPU fault again on 4214c50d8ae3SPaolo Bonzini * the address. 4215c50d8ae3SPaolo Bonzini */ 4216c50d8ae3SPaolo Bonzini return RET_PF_RETRY; 4217c50d8ae3SPaolo Bonzini } 4218c50d8ae3SPaolo Bonzini 4219c50d8ae3SPaolo Bonzini static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, 4220b8a5d551SPaolo Bonzini struct kvm_page_fault *fault) 4221c50d8ae3SPaolo Bonzini { 4222b8a5d551SPaolo Bonzini if (unlikely(fault->rsvd)) 4223c50d8ae3SPaolo Bonzini return false; 4224c50d8ae3SPaolo Bonzini 4225b8a5d551SPaolo Bonzini if (!fault->present || !fault->write) 4226c50d8ae3SPaolo Bonzini return false; 4227c50d8ae3SPaolo Bonzini 4228c50d8ae3SPaolo Bonzini /* 4229c50d8ae3SPaolo Bonzini * guest is writing the page which is write tracked which can 4230c50d8ae3SPaolo Bonzini * not be fixed by page fault handler. 4231c50d8ae3SPaolo Bonzini */ 42329d395a0aSBen Gardon if (kvm_slot_page_track_is_active(vcpu->kvm, fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) 4233c50d8ae3SPaolo Bonzini return true; 4234c50d8ae3SPaolo Bonzini 4235c50d8ae3SPaolo Bonzini return false; 4236c50d8ae3SPaolo Bonzini } 4237c50d8ae3SPaolo Bonzini 4238c50d8ae3SPaolo Bonzini static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) 4239c50d8ae3SPaolo Bonzini { 4240c50d8ae3SPaolo Bonzini struct kvm_shadow_walk_iterator iterator; 4241c50d8ae3SPaolo Bonzini u64 spte; 4242c50d8ae3SPaolo Bonzini 4243c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_begin(vcpu); 42443e44dce4SLai Jiangshan for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) 4245c50d8ae3SPaolo Bonzini clear_sp_write_flooding_count(iterator.sptep); 4246c50d8ae3SPaolo Bonzini walk_shadow_page_lockless_end(vcpu); 4247c50d8ae3SPaolo Bonzini } 4248c50d8ae3SPaolo Bonzini 42496f3c1fc5SLiang Zhang static u32 alloc_apf_token(struct kvm_vcpu *vcpu) 42506f3c1fc5SLiang Zhang { 42516f3c1fc5SLiang Zhang /* make sure the token value is not 0 */ 42526f3c1fc5SLiang Zhang u32 id = vcpu->arch.apf.id; 42536f3c1fc5SLiang Zhang 42546f3c1fc5SLiang Zhang if (id << 12 == 0) 42556f3c1fc5SLiang Zhang vcpu->arch.apf.id = 1; 42566f3c1fc5SLiang Zhang 42576f3c1fc5SLiang Zhang return (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; 42586f3c1fc5SLiang Zhang } 42596f3c1fc5SLiang Zhang 4260e8c22266SVitaly Kuznetsov static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 42619f1a8526SSean Christopherson gfn_t gfn) 4262c50d8ae3SPaolo Bonzini { 4263c50d8ae3SPaolo Bonzini struct kvm_arch_async_pf arch; 4264c50d8ae3SPaolo Bonzini 42656f3c1fc5SLiang Zhang arch.token = alloc_apf_token(vcpu); 4266c50d8ae3SPaolo Bonzini arch.gfn = gfn; 4267347a0d0dSPaolo Bonzini arch.direct_map = vcpu->arch.mmu->root_role.direct; 4268*2fdcc1b3SPaolo Bonzini arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu); 4269c50d8ae3SPaolo Bonzini 42709f1a8526SSean Christopherson return kvm_setup_async_pf(vcpu, cr2_or_gpa, 42719f1a8526SSean Christopherson kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); 4272c50d8ae3SPaolo Bonzini } 4273c50d8ae3SPaolo Bonzini 42748a009d5bSSean Christopherson void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 42758a009d5bSSean Christopherson { 42768a009d5bSSean Christopherson int r; 42778a009d5bSSean Christopherson 42788a009d5bSSean Christopherson if ((vcpu->arch.mmu->root_role.direct != work->arch.direct_map) || 42798a009d5bSSean Christopherson work->wakeup_all) 42808a009d5bSSean Christopherson return; 42818a009d5bSSean Christopherson 42828a009d5bSSean Christopherson r = kvm_mmu_reload(vcpu); 42838a009d5bSSean Christopherson if (unlikely(r)) 42848a009d5bSSean Christopherson return; 42858a009d5bSSean Christopherson 42868a009d5bSSean Christopherson if (!vcpu->arch.mmu->root_role.direct && 4287*2fdcc1b3SPaolo Bonzini work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu)) 42888a009d5bSSean Christopherson return; 42898a009d5bSSean Christopherson 4290258d985fSSean Christopherson kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true, NULL); 42918a009d5bSSean Christopherson } 42928a009d5bSSean Christopherson 4293ba6e3fe2SDavid Matlack static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4294c50d8ae3SPaolo Bonzini { 4295e710c5f6SDavid Matlack struct kvm_memory_slot *slot = fault->slot; 4296c50d8ae3SPaolo Bonzini bool async; 4297c50d8ae3SPaolo Bonzini 4298e0c37868SSean Christopherson /* 4299e0c37868SSean Christopherson * Retry the page fault if the gfn hit a memslot that is being deleted 4300e0c37868SSean Christopherson * or moved. This ensures any existing SPTEs for the old memslot will 4301e0c37868SSean Christopherson * be zapped before KVM inserts a new MMIO SPTE for the gfn. 4302e0c37868SSean Christopherson */ 4303e0c37868SSean Christopherson if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) 43045276c616SSean Christopherson return RET_PF_RETRY; 4305e0c37868SSean Christopherson 43069cc13d60SMaxim Levitsky if (!kvm_is_visible_memslot(slot)) { 4307c36b7150SPaolo Bonzini /* Don't expose private memslots to L2. */ 43089cc13d60SMaxim Levitsky if (is_guest_mode(vcpu)) { 4309e710c5f6SDavid Matlack fault->slot = NULL; 43103647cd04SPaolo Bonzini fault->pfn = KVM_PFN_NOSLOT; 43113647cd04SPaolo Bonzini fault->map_writable = false; 43125276c616SSean Christopherson return RET_PF_CONTINUE; 4313c50d8ae3SPaolo Bonzini } 43149cc13d60SMaxim Levitsky /* 43159cc13d60SMaxim Levitsky * If the APIC access page exists but is disabled, go directly 43169cc13d60SMaxim Levitsky * to emulation without caching the MMIO access or creating a 43179cc13d60SMaxim Levitsky * MMIO SPTE. That way the cache doesn't need to be purged 43189cc13d60SMaxim Levitsky * when the AVIC is re-enabled. 43199cc13d60SMaxim Levitsky */ 43209cc13d60SMaxim Levitsky if (slot && slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT && 43215276c616SSean Christopherson !kvm_apicv_activated(vcpu->kvm)) 43225276c616SSean Christopherson return RET_PF_EMULATE; 43239cc13d60SMaxim Levitsky } 4324c50d8ae3SPaolo Bonzini 4325c50d8ae3SPaolo Bonzini async = false; 4326c8b88b33SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, 43273647cd04SPaolo Bonzini fault->write, &fault->map_writable, 43283647cd04SPaolo Bonzini &fault->hva); 4329c50d8ae3SPaolo Bonzini if (!async) 43305276c616SSean Christopherson return RET_PF_CONTINUE; /* *pfn has correct page already */ 4331c50d8ae3SPaolo Bonzini 43322839180cSPaolo Bonzini if (!fault->prefetch && kvm_can_do_async_pf(vcpu)) { 43333647cd04SPaolo Bonzini trace_kvm_try_async_get_page(fault->addr, fault->gfn); 43343647cd04SPaolo Bonzini if (kvm_find_async_pf_gfn(vcpu, fault->gfn)) { 43351685c0f3SMingwei Zhang trace_kvm_async_pf_repeated_fault(fault->addr, fault->gfn); 4336c50d8ae3SPaolo Bonzini kvm_make_request(KVM_REQ_APF_HALT, vcpu); 43375276c616SSean Christopherson return RET_PF_RETRY; 43385276c616SSean Christopherson } else if (kvm_arch_setup_async_pf(vcpu, fault->addr, fault->gfn)) { 43395276c616SSean Christopherson return RET_PF_RETRY; 43405276c616SSean Christopherson } 4341c50d8ae3SPaolo Bonzini } 4342c50d8ae3SPaolo Bonzini 434376657687SPeter Xu /* 434476657687SPeter Xu * Allow gup to bail on pending non-fatal signals when it's also allowed 434576657687SPeter Xu * to wait for IO. Note, gup always bails if it is unable to quickly 434676657687SPeter Xu * get a page and a fatal signal, i.e. SIGKILL, is pending. 434776657687SPeter Xu */ 434876657687SPeter Xu fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, 43493647cd04SPaolo Bonzini fault->write, &fault->map_writable, 43503647cd04SPaolo Bonzini &fault->hva); 43515276c616SSean Christopherson return RET_PF_CONTINUE; 4352c50d8ae3SPaolo Bonzini } 4353c50d8ae3SPaolo Bonzini 4354354c908cSDavid Matlack static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, 4355354c908cSDavid Matlack unsigned int access) 4356ba6e3fe2SDavid Matlack { 435756c3a4e4SDavid Matlack int ret; 435856c3a4e4SDavid Matlack 4359ba6e3fe2SDavid Matlack fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq; 4360ba6e3fe2SDavid Matlack smp_rmb(); 4361ba6e3fe2SDavid Matlack 436256c3a4e4SDavid Matlack ret = __kvm_faultin_pfn(vcpu, fault); 436356c3a4e4SDavid Matlack if (ret != RET_PF_CONTINUE) 436456c3a4e4SDavid Matlack return ret; 436556c3a4e4SDavid Matlack 436656c3a4e4SDavid Matlack if (unlikely(is_error_pfn(fault->pfn))) 4367cd08d178SDavid Matlack return kvm_handle_error_pfn(vcpu, fault); 436856c3a4e4SDavid Matlack 4369354c908cSDavid Matlack if (unlikely(!fault->slot)) 4370354c908cSDavid Matlack return kvm_handle_noslot_fault(vcpu, fault, access); 4371354c908cSDavid Matlack 437256c3a4e4SDavid Matlack return RET_PF_CONTINUE; 4373ba6e3fe2SDavid Matlack } 4374ba6e3fe2SDavid Matlack 4375a955cad8SSean Christopherson /* 4376a955cad8SSean Christopherson * Returns true if the page fault is stale and needs to be retried, i.e. if the 4377a955cad8SSean Christopherson * root was invalidated by a memslot update or a relevant mmu_notifier fired. 4378a955cad8SSean Christopherson */ 4379a955cad8SSean Christopherson static bool is_page_fault_stale(struct kvm_vcpu *vcpu, 4380ba6e3fe2SDavid Matlack struct kvm_page_fault *fault) 4381a955cad8SSean Christopherson { 4382b9e5603cSPaolo Bonzini struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root.hpa); 438318c841e1SSean Christopherson 438418c841e1SSean Christopherson /* Special roots, e.g. pae_root, are not backed by shadow pages. */ 438518c841e1SSean Christopherson if (sp && is_obsolete_sp(vcpu->kvm, sp)) 438618c841e1SSean Christopherson return true; 438718c841e1SSean Christopherson 438818c841e1SSean Christopherson /* 438918c841e1SSean Christopherson * Roots without an associated shadow page are considered invalid if 439018c841e1SSean Christopherson * there is a pending request to free obsolete roots. The request is 439118c841e1SSean Christopherson * only a hint that the current root _may_ be obsolete and needs to be 439218c841e1SSean Christopherson * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a 439318c841e1SSean Christopherson * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs 439418c841e1SSean Christopherson * to reload even if no vCPU is actively using the root. 439518c841e1SSean Christopherson */ 4396527d5cd7SSean Christopherson if (!sp && kvm_test_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu)) 4397a955cad8SSean Christopherson return true; 4398a955cad8SSean Christopherson 4399a955cad8SSean Christopherson return fault->slot && 4400ba6e3fe2SDavid Matlack mmu_invalidate_retry_hva(vcpu->kvm, fault->mmu_seq, fault->hva); 4401a955cad8SSean Christopherson } 4402a955cad8SSean Christopherson 44034326e57eSPaolo Bonzini static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4404c50d8ae3SPaolo Bonzini { 440583f06fa7SSean Christopherson int r; 4406c50d8ae3SPaolo Bonzini 4407b8a5d551SPaolo Bonzini if (page_fault_handle_page_track(vcpu, fault)) 4408c50d8ae3SPaolo Bonzini return RET_PF_EMULATE; 4409c50d8ae3SPaolo Bonzini 44103c8ad5a6SPaolo Bonzini r = fast_page_fault(vcpu, fault); 4411c4371c2aSSean Christopherson if (r != RET_PF_INVALID) 4412c4371c2aSSean Christopherson return r; 441383291445SSean Christopherson 4414378f5cd6SSean Christopherson r = mmu_topup_memory_caches(vcpu, false); 4415c50d8ae3SPaolo Bonzini if (r) 4416c50d8ae3SPaolo Bonzini return r; 4417c50d8ae3SPaolo Bonzini 4418354c908cSDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 44195276c616SSean Christopherson if (r != RET_PF_CONTINUE) 4420367fd790SSean Christopherson return r; 4421367fd790SSean Christopherson 4422367fd790SSean Christopherson r = RET_PF_RETRY; 4423531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 4424a2855afcSBen Gardon 4425ba6e3fe2SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 4426367fd790SSean Christopherson goto out_unlock; 4427a955cad8SSean Christopherson 44287bd7ded6SSean Christopherson r = make_mmu_pages_available(vcpu); 44297bd7ded6SSean Christopherson if (r) 4430367fd790SSean Christopherson goto out_unlock; 4431bb18842eSBen Gardon 44326c882ef4SDavid Matlack r = direct_map(vcpu, fault); 44330f90e1c1SSean Christopherson 4434367fd790SSean Christopherson out_unlock: 4435531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 44363647cd04SPaolo Bonzini kvm_release_pfn_clean(fault->pfn); 4437367fd790SSean Christopherson return r; 4438c50d8ae3SPaolo Bonzini } 4439c50d8ae3SPaolo Bonzini 4440c501040aSPaolo Bonzini static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 4441c501040aSPaolo Bonzini struct kvm_page_fault *fault) 44420f90e1c1SSean Christopherson { 44434326e57eSPaolo Bonzini pgprintk("%s: gva %lx error %x\n", __func__, fault->addr, fault->error_code); 44440f90e1c1SSean Christopherson 44450f90e1c1SSean Christopherson /* This path builds a PAE pagetable, we can map 2mb pages at maximum. */ 44464326e57eSPaolo Bonzini fault->max_level = PG_LEVEL_2M; 44474326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 44480f90e1c1SSean Christopherson } 44490f90e1c1SSean Christopherson 4450c50d8ae3SPaolo Bonzini int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 4451c50d8ae3SPaolo Bonzini u64 fault_address, char *insn, int insn_len) 4452c50d8ae3SPaolo Bonzini { 4453c50d8ae3SPaolo Bonzini int r = 1; 44549ce372b3SVitaly Kuznetsov u32 flags = vcpu->arch.apf.host_apf_flags; 4455c50d8ae3SPaolo Bonzini 4456736c291cSSean Christopherson #ifndef CONFIG_X86_64 4457736c291cSSean Christopherson /* A 64-bit CR2 should be impossible on 32-bit KVM. */ 4458736c291cSSean Christopherson if (WARN_ON_ONCE(fault_address >> 32)) 4459736c291cSSean Christopherson return -EFAULT; 4460736c291cSSean Christopherson #endif 4461736c291cSSean Christopherson 4462c50d8ae3SPaolo Bonzini vcpu->arch.l1tf_flush_l1d = true; 44639ce372b3SVitaly Kuznetsov if (!flags) { 4464faa03b39SWonhyuk Yang trace_kvm_page_fault(vcpu, fault_address, error_code); 4465c50d8ae3SPaolo Bonzini 4466c50d8ae3SPaolo Bonzini if (kvm_event_needs_reinjection(vcpu)) 4467c50d8ae3SPaolo Bonzini kvm_mmu_unprotect_page_virt(vcpu, fault_address); 4468c50d8ae3SPaolo Bonzini r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, 4469c50d8ae3SPaolo Bonzini insn_len); 44709ce372b3SVitaly Kuznetsov } else if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) { 447168fd66f1SVitaly Kuznetsov vcpu->arch.apf.host_apf_flags = 0; 4472c50d8ae3SPaolo Bonzini local_irq_disable(); 44736bca69adSThomas Gleixner kvm_async_pf_task_wait_schedule(fault_address); 4474c50d8ae3SPaolo Bonzini local_irq_enable(); 44759ce372b3SVitaly Kuznetsov } else { 44769ce372b3SVitaly Kuznetsov WARN_ONCE(1, "Unexpected host async PF flags: %x\n", flags); 4477c50d8ae3SPaolo Bonzini } 44789ce372b3SVitaly Kuznetsov 4479c50d8ae3SPaolo Bonzini return r; 4480c50d8ae3SPaolo Bonzini } 4481c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_handle_page_fault); 4482c50d8ae3SPaolo Bonzini 44839aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 44849aa8ab43SDavid Matlack static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, 44859aa8ab43SDavid Matlack struct kvm_page_fault *fault) 44869aa8ab43SDavid Matlack { 44879aa8ab43SDavid Matlack int r; 44889aa8ab43SDavid Matlack 44899aa8ab43SDavid Matlack if (page_fault_handle_page_track(vcpu, fault)) 44909aa8ab43SDavid Matlack return RET_PF_EMULATE; 44919aa8ab43SDavid Matlack 44929aa8ab43SDavid Matlack r = fast_page_fault(vcpu, fault); 44939aa8ab43SDavid Matlack if (r != RET_PF_INVALID) 44949aa8ab43SDavid Matlack return r; 44959aa8ab43SDavid Matlack 44969aa8ab43SDavid Matlack r = mmu_topup_memory_caches(vcpu, false); 44979aa8ab43SDavid Matlack if (r) 44989aa8ab43SDavid Matlack return r; 44999aa8ab43SDavid Matlack 45009aa8ab43SDavid Matlack r = kvm_faultin_pfn(vcpu, fault, ACC_ALL); 45019aa8ab43SDavid Matlack if (r != RET_PF_CONTINUE) 45029aa8ab43SDavid Matlack return r; 45039aa8ab43SDavid Matlack 45049aa8ab43SDavid Matlack r = RET_PF_RETRY; 45059aa8ab43SDavid Matlack read_lock(&vcpu->kvm->mmu_lock); 45069aa8ab43SDavid Matlack 45079aa8ab43SDavid Matlack if (is_page_fault_stale(vcpu, fault)) 45089aa8ab43SDavid Matlack goto out_unlock; 45099aa8ab43SDavid Matlack 45109aa8ab43SDavid Matlack r = kvm_tdp_mmu_map(vcpu, fault); 45119aa8ab43SDavid Matlack 45129aa8ab43SDavid Matlack out_unlock: 45139aa8ab43SDavid Matlack read_unlock(&vcpu->kvm->mmu_lock); 45149aa8ab43SDavid Matlack kvm_release_pfn_clean(fault->pfn); 45159aa8ab43SDavid Matlack return r; 45169aa8ab43SDavid Matlack } 45179aa8ab43SDavid Matlack #endif 45189aa8ab43SDavid Matlack 4519c501040aSPaolo Bonzini int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 4520c50d8ae3SPaolo Bonzini { 4521d5e90a69SSean Christopherson /* 4522d5e90a69SSean Christopherson * If the guest's MTRRs may be used to compute the "real" memtype, 4523d5e90a69SSean Christopherson * restrict the mapping level to ensure KVM uses a consistent memtype 4524d5e90a69SSean Christopherson * across the entire mapping. If the host MTRRs are ignored by TDP 4525d5e90a69SSean Christopherson * (shadow_memtype_mask is non-zero), and the VM has non-coherent DMA 4526d5e90a69SSean Christopherson * (DMA doesn't snoop CPU caches), KVM's ABI is to honor the memtype 4527d5e90a69SSean Christopherson * from the guest's MTRRs so that guest accesses to memory that is 4528d5e90a69SSean Christopherson * DMA'd aren't cached against the guest's wishes. 4529d5e90a69SSean Christopherson * 4530d5e90a69SSean Christopherson * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs, 4531d5e90a69SSean Christopherson * e.g. KVM will force UC memtype for host MMIO. 4532d5e90a69SSean Christopherson */ 4533d5e90a69SSean Christopherson if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) { 4534d5e90a69SSean Christopherson for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) { 45354326e57eSPaolo Bonzini int page_num = KVM_PAGES_PER_HPAGE(fault->max_level); 4536c667a3baSHou Wenlong gfn_t base = gfn_round_for_level(fault->gfn, 4537c667a3baSHou Wenlong fault->max_level); 4538c50d8ae3SPaolo Bonzini 4539cb9b88c6SSean Christopherson if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num)) 4540cb9b88c6SSean Christopherson break; 4541d5e90a69SSean Christopherson } 4542c50d8ae3SPaolo Bonzini } 4543c50d8ae3SPaolo Bonzini 45449aa8ab43SDavid Matlack #ifdef CONFIG_X86_64 45459aa8ab43SDavid Matlack if (tdp_mmu_enabled) 45469aa8ab43SDavid Matlack return kvm_tdp_mmu_page_fault(vcpu, fault); 45479aa8ab43SDavid Matlack #endif 45489aa8ab43SDavid Matlack 45494326e57eSPaolo Bonzini return direct_page_fault(vcpu, fault); 4550c50d8ae3SPaolo Bonzini } 4551c50d8ae3SPaolo Bonzini 455284a16226SSean Christopherson static void nonpaging_init_context(struct kvm_mmu *context) 4553c50d8ae3SPaolo Bonzini { 4554c50d8ae3SPaolo Bonzini context->page_fault = nonpaging_page_fault; 4555c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 4556c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 4557c50d8ae3SPaolo Bonzini } 4558c50d8ae3SPaolo Bonzini 4559be01e8e2SSean Christopherson static inline bool is_root_usable(struct kvm_mmu_root_info *root, gpa_t pgd, 45600be44352SSean Christopherson union kvm_mmu_page_role role) 45610be44352SSean Christopherson { 4562be01e8e2SSean Christopherson return (role.direct || pgd == root->pgd) && 45635499ea73SPaolo Bonzini VALID_PAGE(root->hpa) && 4564e47c4aeeSSean Christopherson role.word == to_shadow_page(root->hpa)->role.word; 45650be44352SSean Christopherson } 45660be44352SSean Christopherson 4567c50d8ae3SPaolo Bonzini /* 45685499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available, 45695499ea73SPaolo Bonzini * and insert the current root as the MRU in the cache. 45705499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root and 45715499ea73SPaolo Bonzini * true is returned. 45725499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid, the LRU root is 45735499ea73SPaolo Bonzini * evicted to make room for the current root, and false is returned. 4574c50d8ae3SPaolo Bonzini */ 45755499ea73SPaolo Bonzini static bool cached_root_find_and_keep_current(struct kvm *kvm, struct kvm_mmu *mmu, 45765499ea73SPaolo Bonzini gpa_t new_pgd, 4577c50d8ae3SPaolo Bonzini union kvm_mmu_page_role new_role) 4578c50d8ae3SPaolo Bonzini { 4579c50d8ae3SPaolo Bonzini uint i; 4580c50d8ae3SPaolo Bonzini 4581b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 45820be44352SSean Christopherson return true; 45830be44352SSean Christopherson 4584c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 45855499ea73SPaolo Bonzini /* 45865499ea73SPaolo Bonzini * The swaps end up rotating the cache like this: 45875499ea73SPaolo Bonzini * C 0 1 2 3 (on entry to the function) 45885499ea73SPaolo Bonzini * 0 C 1 2 3 45895499ea73SPaolo Bonzini * 1 C 0 2 3 45905499ea73SPaolo Bonzini * 2 C 0 1 3 45915499ea73SPaolo Bonzini * 3 C 0 1 2 (on exit from the loop) 45925499ea73SPaolo Bonzini */ 4593b9e5603cSPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 4594b9e5603cSPaolo Bonzini if (is_root_usable(&mmu->root, new_pgd, new_role)) 45955499ea73SPaolo Bonzini return true; 4596c50d8ae3SPaolo Bonzini } 4597c50d8ae3SPaolo Bonzini 45985499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 45995499ea73SPaolo Bonzini return false; 4600c50d8ae3SPaolo Bonzini } 4601c50d8ae3SPaolo Bonzini 4602c50d8ae3SPaolo Bonzini /* 46035499ea73SPaolo Bonzini * Find out if a previously cached root matching the new pgd/role is available. 46045499ea73SPaolo Bonzini * On entry, mmu->root is invalid. 46055499ea73SPaolo Bonzini * If a matching root is found, it is assigned to kvm_mmu->root, the LRU entry 46065499ea73SPaolo Bonzini * of the cache becomes invalid, and true is returned. 46075499ea73SPaolo Bonzini * If no match is found, kvm_mmu->root is left invalid and false is returned. 46085499ea73SPaolo Bonzini */ 46095499ea73SPaolo Bonzini static bool cached_root_find_without_current(struct kvm *kvm, struct kvm_mmu *mmu, 46105499ea73SPaolo Bonzini gpa_t new_pgd, 46115499ea73SPaolo Bonzini union kvm_mmu_page_role new_role) 46125499ea73SPaolo Bonzini { 46135499ea73SPaolo Bonzini uint i; 46145499ea73SPaolo Bonzini 46155499ea73SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 46165499ea73SPaolo Bonzini if (is_root_usable(&mmu->prev_roots[i], new_pgd, new_role)) 46175499ea73SPaolo Bonzini goto hit; 46185499ea73SPaolo Bonzini 46195499ea73SPaolo Bonzini return false; 46205499ea73SPaolo Bonzini 46215499ea73SPaolo Bonzini hit: 46225499ea73SPaolo Bonzini swap(mmu->root, mmu->prev_roots[i]); 46235499ea73SPaolo Bonzini /* Bubble up the remaining roots. */ 46245499ea73SPaolo Bonzini for (; i < KVM_MMU_NUM_PREV_ROOTS - 1; i++) 46255499ea73SPaolo Bonzini mmu->prev_roots[i] = mmu->prev_roots[i + 1]; 46265499ea73SPaolo Bonzini mmu->prev_roots[i].hpa = INVALID_PAGE; 46275499ea73SPaolo Bonzini return true; 46285499ea73SPaolo Bonzini } 46295499ea73SPaolo Bonzini 46305499ea73SPaolo Bonzini static bool fast_pgd_switch(struct kvm *kvm, struct kvm_mmu *mmu, 46315499ea73SPaolo Bonzini gpa_t new_pgd, union kvm_mmu_page_role new_role) 46325499ea73SPaolo Bonzini { 46335499ea73SPaolo Bonzini /* 46345499ea73SPaolo Bonzini * For now, limit the caching to 64-bit hosts+VMs in order to avoid 4635c50d8ae3SPaolo Bonzini * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs 4636c50d8ae3SPaolo Bonzini * later if necessary. 4637c50d8ae3SPaolo Bonzini */ 46385499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa) && !to_shadow_page(mmu->root.hpa)) 46395499ea73SPaolo Bonzini kvm_mmu_free_roots(kvm, mmu, KVM_MMU_ROOT_CURRENT); 4640c50d8ae3SPaolo Bonzini 46415499ea73SPaolo Bonzini if (VALID_PAGE(mmu->root.hpa)) 46425499ea73SPaolo Bonzini return cached_root_find_and_keep_current(kvm, mmu, new_pgd, new_role); 46435499ea73SPaolo Bonzini else 46445499ea73SPaolo Bonzini return cached_root_find_without_current(kvm, mmu, new_pgd, new_role); 4645c50d8ae3SPaolo Bonzini } 4646c50d8ae3SPaolo Bonzini 4647d2e5f333SPaolo Bonzini void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) 4648c50d8ae3SPaolo Bonzini { 46490c1c92f1SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 46507a458f0eSPaolo Bonzini union kvm_mmu_page_role new_role = mmu->root_role; 46510c1c92f1SPaolo Bonzini 4652a7e48ef7SWei Liu /* 4653a7e48ef7SWei Liu * Return immediately if no usable root was found, kvm_mmu_reload() 4654a7e48ef7SWei Liu * will establish a valid root prior to the next VM-Enter. 4655a7e48ef7SWei Liu */ 4656a7e48ef7SWei Liu if (!fast_pgd_switch(vcpu->kvm, mmu, new_pgd, new_role)) 4657b869855bSSean Christopherson return; 4658c50d8ae3SPaolo Bonzini 4659c50d8ae3SPaolo Bonzini /* 4660b869855bSSean Christopherson * It's possible that the cached previous root page is obsolete because 4661b869855bSSean Christopherson * of a change in the MMU generation number. However, changing the 4662527d5cd7SSean Christopherson * generation number is accompanied by KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, 4663527d5cd7SSean Christopherson * which will free the root set here and allocate a new one. 4664b869855bSSean Christopherson */ 4665b869855bSSean Christopherson kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu); 4666b869855bSSean Christopherson 4667b5129100SSean Christopherson if (force_flush_and_sync_on_reuse) { 4668b869855bSSean Christopherson kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); 4669b869855bSSean Christopherson kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 4670b5129100SSean Christopherson } 4671b869855bSSean Christopherson 4672b869855bSSean Christopherson /* 4673b869855bSSean Christopherson * The last MMIO access's GVA and GPA are cached in the VCPU. When 4674b869855bSSean Christopherson * switching to a new CR3, that GVA->GPA mapping may no longer be 4675b869855bSSean Christopherson * valid. So clear any cached MMIO info even when we don't need to sync 4676b869855bSSean Christopherson * the shadow page tables. 4677c50d8ae3SPaolo Bonzini */ 4678c50d8ae3SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 4679c50d8ae3SPaolo Bonzini 4680daa5b6c1SBen Gardon /* 4681daa5b6c1SBen Gardon * If this is a direct root page, it doesn't have a write flooding 4682daa5b6c1SBen Gardon * count. Otherwise, clear the write flooding count. 4683daa5b6c1SBen Gardon */ 4684daa5b6c1SBen Gardon if (!new_role.direct) 4685daa5b6c1SBen Gardon __clear_sp_write_flooding_count( 4686b9e5603cSPaolo Bonzini to_shadow_page(vcpu->arch.mmu->root.hpa)); 4687c50d8ae3SPaolo Bonzini } 4688be01e8e2SSean Christopherson EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); 4689c50d8ae3SPaolo Bonzini 4690c50d8ae3SPaolo Bonzini static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, 4691c3e5e415SLai Jiangshan unsigned int access) 4692c50d8ae3SPaolo Bonzini { 4693c50d8ae3SPaolo Bonzini if (unlikely(is_mmio_spte(*sptep))) { 4694c50d8ae3SPaolo Bonzini if (gfn != get_mmio_spte_gfn(*sptep)) { 4695c50d8ae3SPaolo Bonzini mmu_spte_clear_no_track(sptep); 4696c50d8ae3SPaolo Bonzini return true; 4697c50d8ae3SPaolo Bonzini } 4698c50d8ae3SPaolo Bonzini 4699c50d8ae3SPaolo Bonzini mark_mmio_spte(vcpu, sptep, gfn, access); 4700c50d8ae3SPaolo Bonzini return true; 4701c50d8ae3SPaolo Bonzini } 4702c50d8ae3SPaolo Bonzini 4703c50d8ae3SPaolo Bonzini return false; 4704c50d8ae3SPaolo Bonzini } 4705c50d8ae3SPaolo Bonzini 4706c50d8ae3SPaolo Bonzini #define PTTYPE_EPT 18 /* arbitrary */ 4707c50d8ae3SPaolo Bonzini #define PTTYPE PTTYPE_EPT 4708c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4709c50d8ae3SPaolo Bonzini #undef PTTYPE 4710c50d8ae3SPaolo Bonzini 4711c50d8ae3SPaolo Bonzini #define PTTYPE 64 4712c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4713c50d8ae3SPaolo Bonzini #undef PTTYPE 4714c50d8ae3SPaolo Bonzini 4715c50d8ae3SPaolo Bonzini #define PTTYPE 32 4716c50d8ae3SPaolo Bonzini #include "paging_tmpl.h" 4717c50d8ae3SPaolo Bonzini #undef PTTYPE 4718c50d8ae3SPaolo Bonzini 4719f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, 4720f3d90f90SSean Christopherson u64 pa_bits_rsvd, int level, bool nx, 4721f3d90f90SSean Christopherson bool gbpages, bool pse, bool amd) 4722c50d8ae3SPaolo Bonzini { 4723c50d8ae3SPaolo Bonzini u64 gbpages_bit_rsvd = 0; 4724c50d8ae3SPaolo Bonzini u64 nonleaf_bit8_rsvd = 0; 47255b7f575cSSean Christopherson u64 high_bits_rsvd; 4726c50d8ae3SPaolo Bonzini 4727c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = 0; 4728c50d8ae3SPaolo Bonzini 4729c50d8ae3SPaolo Bonzini if (!gbpages) 4730c50d8ae3SPaolo Bonzini gbpages_bit_rsvd = rsvd_bits(7, 7); 4731c50d8ae3SPaolo Bonzini 47325b7f575cSSean Christopherson if (level == PT32E_ROOT_LEVEL) 47335b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 62); 47345b7f575cSSean Christopherson else 47355b7f575cSSean Christopherson high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 47365b7f575cSSean Christopherson 47375b7f575cSSean Christopherson /* Note, NX doesn't exist in PDPTEs, this is handled below. */ 47385b7f575cSSean Christopherson if (!nx) 47395b7f575cSSean Christopherson high_bits_rsvd |= rsvd_bits(63, 63); 47405b7f575cSSean Christopherson 4741c50d8ae3SPaolo Bonzini /* 4742c50d8ae3SPaolo Bonzini * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for 4743c50d8ae3SPaolo Bonzini * leaf entries) on AMD CPUs only. 4744c50d8ae3SPaolo Bonzini */ 4745c50d8ae3SPaolo Bonzini if (amd) 4746c50d8ae3SPaolo Bonzini nonleaf_bit8_rsvd = rsvd_bits(8, 8); 4747c50d8ae3SPaolo Bonzini 4748c50d8ae3SPaolo Bonzini switch (level) { 4749c50d8ae3SPaolo Bonzini case PT32_ROOT_LEVEL: 4750c50d8ae3SPaolo Bonzini /* no rsvd bits for 2 level 4K page table entries */ 4751c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][1] = 0; 4752c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0] = 0; 4753c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4754c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4755c50d8ae3SPaolo Bonzini 4756c50d8ae3SPaolo Bonzini if (!pse) { 4757c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = 0; 4758c50d8ae3SPaolo Bonzini break; 4759c50d8ae3SPaolo Bonzini } 4760c50d8ae3SPaolo Bonzini 4761c50d8ae3SPaolo Bonzini if (is_cpuid_PSE36()) 4762c50d8ae3SPaolo Bonzini /* 36bits PSE 4MB page */ 4763c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); 4764c50d8ae3SPaolo Bonzini else 4765c50d8ae3SPaolo Bonzini /* 32 bits PSE 4MB page */ 4766c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); 4767c50d8ae3SPaolo Bonzini break; 4768c50d8ae3SPaolo Bonzini case PT32E_ROOT_LEVEL: 47695b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = rsvd_bits(63, 63) | 47705b7f575cSSean Christopherson high_bits_rsvd | 47715b7f575cSSean Christopherson rsvd_bits(5, 8) | 47725b7f575cSSean Christopherson rsvd_bits(1, 2); /* PDPTE */ 47735b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; /* PDE */ 47745b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; /* PTE */ 47755b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4776c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4777c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4778c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4779c50d8ae3SPaolo Bonzini break; 4780c50d8ae3SPaolo Bonzini case PT64_ROOT_5LEVEL: 47815b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | 47825b7f575cSSean Christopherson nonleaf_bit8_rsvd | 47835b7f575cSSean Christopherson rsvd_bits(7, 7); 4784c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = 4785c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][4]; 4786df561f66SGustavo A. R. Silva fallthrough; 4787c50d8ae3SPaolo Bonzini case PT64_ROOT_4LEVEL: 47885b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | 47895b7f575cSSean Christopherson nonleaf_bit8_rsvd | 47905b7f575cSSean Christopherson rsvd_bits(7, 7); 47915b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | 47925b7f575cSSean Christopherson gbpages_bit_rsvd; 47935b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd; 47945b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4795c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = 4796c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][3]; 47975b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | 47985b7f575cSSean Christopherson gbpages_bit_rsvd | 4799c50d8ae3SPaolo Bonzini rsvd_bits(13, 29); 48005b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | 4801c50d8ae3SPaolo Bonzini rsvd_bits(13, 20); /* large page */ 4802c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = 4803c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[0][0]; 4804c50d8ae3SPaolo Bonzini break; 4805c50d8ae3SPaolo Bonzini } 4806c50d8ae3SPaolo Bonzini } 4807c50d8ae3SPaolo Bonzini 480827de9250SSean Christopherson static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) 480927de9250SSean Christopherson { 481027de9250SSean Christopherson /* 481127de9250SSean Christopherson * If TDP is enabled, let the guest use GBPAGES if they're supported in 481227de9250SSean Christopherson * hardware. The hardware page walker doesn't let KVM disable GBPAGES, 481327de9250SSean Christopherson * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA 481427de9250SSean Christopherson * walk for performance and complexity reasons. Not to mention KVM 481527de9250SSean Christopherson * _can't_ solve the problem because GVA->GPA walks aren't visible to 481627de9250SSean Christopherson * KVM once a TDP translation is installed. Mimic hardware behavior so 481727de9250SSean Christopherson * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. 481827de9250SSean Christopherson */ 481927de9250SSean Christopherson return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : 482027de9250SSean Christopherson guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); 482127de9250SSean Christopherson } 482227de9250SSean Christopherson 4823c919e881SKai Huang static void reset_guest_rsvds_bits_mask(struct kvm_vcpu *vcpu, 4824c50d8ae3SPaolo Bonzini struct kvm_mmu *context) 4825c50d8ae3SPaolo Bonzini { 4826b705a277SSean Christopherson __reset_rsvds_bits_mask(&context->guest_rsvd_check, 48275b7f575cSSean Christopherson vcpu->arch.reserved_gpa_bits, 48284d25502aSPaolo Bonzini context->cpu_role.base.level, is_efer_nx(context), 482927de9250SSean Christopherson guest_can_use_gbpages(vcpu), 48304e9c0d80SSean Christopherson is_cr4_pse(context), 483123493d0aSSean Christopherson guest_cpuid_is_amd_or_hygon(vcpu)); 4832c50d8ae3SPaolo Bonzini } 4833c50d8ae3SPaolo Bonzini 4834f3d90f90SSean Christopherson static void __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, 4835f3d90f90SSean Christopherson u64 pa_bits_rsvd, bool execonly, 4836f3d90f90SSean Christopherson int huge_page_level) 4837c50d8ae3SPaolo Bonzini { 48385b7f575cSSean Christopherson u64 high_bits_rsvd = pa_bits_rsvd & rsvd_bits(0, 51); 483984ea5c09SLai Jiangshan u64 large_1g_rsvd = 0, large_2m_rsvd = 0; 4840c50d8ae3SPaolo Bonzini u64 bad_mt_xwr; 4841c50d8ae3SPaolo Bonzini 484284ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_1G) 484384ea5c09SLai Jiangshan large_1g_rsvd = rsvd_bits(7, 7); 484484ea5c09SLai Jiangshan if (huge_page_level < PG_LEVEL_2M) 484584ea5c09SLai Jiangshan large_2m_rsvd = rsvd_bits(7, 7); 484684ea5c09SLai Jiangshan 48475b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][4] = high_bits_rsvd | rsvd_bits(3, 7); 48485b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][3] = high_bits_rsvd | rsvd_bits(3, 7); 484984ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][2] = high_bits_rsvd | rsvd_bits(3, 6) | large_1g_rsvd; 485084ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[0][1] = high_bits_rsvd | rsvd_bits(3, 6) | large_2m_rsvd; 48515b7f575cSSean Christopherson rsvd_check->rsvd_bits_mask[0][0] = high_bits_rsvd; 4852c50d8ae3SPaolo Bonzini 4853c50d8ae3SPaolo Bonzini /* large page */ 4854c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][4] = rsvd_check->rsvd_bits_mask[0][4]; 4855c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][3] = rsvd_check->rsvd_bits_mask[0][3]; 485684ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][2] = high_bits_rsvd | rsvd_bits(12, 29) | large_1g_rsvd; 485784ea5c09SLai Jiangshan rsvd_check->rsvd_bits_mask[1][1] = high_bits_rsvd | rsvd_bits(12, 20) | large_2m_rsvd; 4858c50d8ae3SPaolo Bonzini rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; 4859c50d8ae3SPaolo Bonzini 4860c50d8ae3SPaolo Bonzini bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ 4861c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ 4862c50d8ae3SPaolo Bonzini bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ 4863c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ 4864c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ 4865c50d8ae3SPaolo Bonzini if (!execonly) { 4866c50d8ae3SPaolo Bonzini /* bits 0..2 must not be 100 unless VMX capabilities allow it */ 4867c50d8ae3SPaolo Bonzini bad_mt_xwr |= REPEAT_BYTE(1ull << 4); 4868c50d8ae3SPaolo Bonzini } 4869c50d8ae3SPaolo Bonzini rsvd_check->bad_mt_xwr = bad_mt_xwr; 4870c50d8ae3SPaolo Bonzini } 4871c50d8ae3SPaolo Bonzini 4872c50d8ae3SPaolo Bonzini static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, 487384ea5c09SLai Jiangshan struct kvm_mmu *context, bool execonly, int huge_page_level) 4874c50d8ae3SPaolo Bonzini { 4875c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->guest_rsvd_check, 487684ea5c09SLai Jiangshan vcpu->arch.reserved_gpa_bits, execonly, 487784ea5c09SLai Jiangshan huge_page_level); 4878c50d8ae3SPaolo Bonzini } 4879c50d8ae3SPaolo Bonzini 48806f8e65a6SSean Christopherson static inline u64 reserved_hpa_bits(void) 48816f8e65a6SSean Christopherson { 48826f8e65a6SSean Christopherson return rsvd_bits(shadow_phys_bits, 63); 48836f8e65a6SSean Christopherson } 48846f8e65a6SSean Christopherson 4885c50d8ae3SPaolo Bonzini /* 4886c50d8ae3SPaolo Bonzini * the page table on host is the shadow page table for the page 4887c50d8ae3SPaolo Bonzini * table in guest or amd nested guest, its mmu features completely 4888c50d8ae3SPaolo Bonzini * follow the features in guest. 4889c50d8ae3SPaolo Bonzini */ 489016be1d12SSean Christopherson static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, 489116be1d12SSean Christopherson struct kvm_mmu *context) 4892c50d8ae3SPaolo Bonzini { 48938c985b2dSSean Christopherson /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ 48948c985b2dSSean Christopherson bool is_amd = true; 48958c985b2dSSean Christopherson /* KVM doesn't use 2-level page tables for the shadow MMU. */ 48968c985b2dSSean Christopherson bool is_pse = false; 4897c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4898c50d8ae3SPaolo Bonzini int i; 4899c50d8ae3SPaolo Bonzini 4900a972e29cSPaolo Bonzini WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL); 49018c985b2dSSean Christopherson 4902c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4903b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 4904a972e29cSPaolo Bonzini context->root_role.level, 49057a458f0eSPaolo Bonzini context->root_role.efer_nx, 490627de9250SSean Christopherson guest_can_use_gbpages(vcpu), is_pse, is_amd); 4907c50d8ae3SPaolo Bonzini 4908c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4909c50d8ae3SPaolo Bonzini return; 4910c50d8ae3SPaolo Bonzini 4911a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4912e54f1ff2SKai Huang /* 4913e54f1ff2SKai Huang * So far shadow_me_value is a constant during KVM's life 4914e54f1ff2SKai Huang * time. Bits in shadow_me_value are allowed to be set. 4915e54f1ff2SKai Huang * Bits in shadow_me_mask but not in shadow_me_value are 4916e54f1ff2SKai Huang * not allowed to be set. 4917e54f1ff2SKai Huang */ 4918e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] |= shadow_me_mask; 4919e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] |= shadow_me_mask; 4920e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_value; 4921e54f1ff2SKai Huang shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_value; 4922c50d8ae3SPaolo Bonzini } 4923c50d8ae3SPaolo Bonzini 4924c50d8ae3SPaolo Bonzini } 4925c50d8ae3SPaolo Bonzini 4926c50d8ae3SPaolo Bonzini static inline bool boot_cpu_is_amd(void) 4927c50d8ae3SPaolo Bonzini { 4928c50d8ae3SPaolo Bonzini WARN_ON_ONCE(!tdp_enabled); 4929c50d8ae3SPaolo Bonzini return shadow_x_mask == 0; 4930c50d8ae3SPaolo Bonzini } 4931c50d8ae3SPaolo Bonzini 4932c50d8ae3SPaolo Bonzini /* 4933c50d8ae3SPaolo Bonzini * the direct page table on host, use as much mmu features as 4934c50d8ae3SPaolo Bonzini * possible, however, kvm currently does not do execution-protection. 4935c50d8ae3SPaolo Bonzini */ 4936f3d90f90SSean Christopherson static void reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context) 4937c50d8ae3SPaolo Bonzini { 4938c50d8ae3SPaolo Bonzini struct rsvd_bits_validate *shadow_zero_check; 4939c50d8ae3SPaolo Bonzini int i; 4940c50d8ae3SPaolo Bonzini 4941c50d8ae3SPaolo Bonzini shadow_zero_check = &context->shadow_zero_check; 4942c50d8ae3SPaolo Bonzini 4943c50d8ae3SPaolo Bonzini if (boot_cpu_is_amd()) 4944b705a277SSean Christopherson __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), 49456c6ab524SSean Christopherson context->root_role.level, true, 4946c50d8ae3SPaolo Bonzini boot_cpu_has(X86_FEATURE_GBPAGES), 49478c985b2dSSean Christopherson false, true); 4948c50d8ae3SPaolo Bonzini else 4949c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(shadow_zero_check, 495084ea5c09SLai Jiangshan reserved_hpa_bits(), false, 495184ea5c09SLai Jiangshan max_huge_page_level); 4952c50d8ae3SPaolo Bonzini 4953c50d8ae3SPaolo Bonzini if (!shadow_me_mask) 4954c50d8ae3SPaolo Bonzini return; 4955c50d8ae3SPaolo Bonzini 4956a972e29cSPaolo Bonzini for (i = context->root_role.level; --i >= 0;) { 4957c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask; 4958c50d8ae3SPaolo Bonzini shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask; 4959c50d8ae3SPaolo Bonzini } 4960c50d8ae3SPaolo Bonzini } 4961c50d8ae3SPaolo Bonzini 4962c50d8ae3SPaolo Bonzini /* 4963c50d8ae3SPaolo Bonzini * as the comments in reset_shadow_zero_bits_mask() except it 4964c50d8ae3SPaolo Bonzini * is the shadow page table for intel nested guest. 4965c50d8ae3SPaolo Bonzini */ 4966c50d8ae3SPaolo Bonzini static void 4967e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(struct kvm_mmu *context, bool execonly) 4968c50d8ae3SPaolo Bonzini { 4969c50d8ae3SPaolo Bonzini __reset_rsvds_bits_mask_ept(&context->shadow_zero_check, 497084ea5c09SLai Jiangshan reserved_hpa_bits(), execonly, 497184ea5c09SLai Jiangshan max_huge_page_level); 4972c50d8ae3SPaolo Bonzini } 4973c50d8ae3SPaolo Bonzini 4974c50d8ae3SPaolo Bonzini #define BYTE_MASK(access) \ 4975c50d8ae3SPaolo Bonzini ((1 & (access) ? 2 : 0) | \ 4976c50d8ae3SPaolo Bonzini (2 & (access) ? 4 : 0) | \ 4977c50d8ae3SPaolo Bonzini (3 & (access) ? 8 : 0) | \ 4978c50d8ae3SPaolo Bonzini (4 & (access) ? 16 : 0) | \ 4979c50d8ae3SPaolo Bonzini (5 & (access) ? 32 : 0) | \ 4980c50d8ae3SPaolo Bonzini (6 & (access) ? 64 : 0) | \ 4981c50d8ae3SPaolo Bonzini (7 & (access) ? 128 : 0)) 4982c50d8ae3SPaolo Bonzini 4983c50d8ae3SPaolo Bonzini 4984c596f147SSean Christopherson static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept) 4985c50d8ae3SPaolo Bonzini { 4986c50d8ae3SPaolo Bonzini unsigned byte; 4987c50d8ae3SPaolo Bonzini 4988c50d8ae3SPaolo Bonzini const u8 x = BYTE_MASK(ACC_EXEC_MASK); 4989c50d8ae3SPaolo Bonzini const u8 w = BYTE_MASK(ACC_WRITE_MASK); 4990c50d8ae3SPaolo Bonzini const u8 u = BYTE_MASK(ACC_USER_MASK); 4991c50d8ae3SPaolo Bonzini 4992c596f147SSean Christopherson bool cr4_smep = is_cr4_smep(mmu); 4993c596f147SSean Christopherson bool cr4_smap = is_cr4_smap(mmu); 4994c596f147SSean Christopherson bool cr0_wp = is_cr0_wp(mmu); 499590599c28SSean Christopherson bool efer_nx = is_efer_nx(mmu); 4996c50d8ae3SPaolo Bonzini 4997c50d8ae3SPaolo Bonzini for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { 4998c50d8ae3SPaolo Bonzini unsigned pfec = byte << 1; 4999c50d8ae3SPaolo Bonzini 5000c50d8ae3SPaolo Bonzini /* 5001c50d8ae3SPaolo Bonzini * Each "*f" variable has a 1 bit for each UWX value 5002c50d8ae3SPaolo Bonzini * that causes a fault with the given PFEC. 5003c50d8ae3SPaolo Bonzini */ 5004c50d8ae3SPaolo Bonzini 5005c50d8ae3SPaolo Bonzini /* Faults from writes to non-writable pages */ 5006c50d8ae3SPaolo Bonzini u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; 5007c50d8ae3SPaolo Bonzini /* Faults from user mode accesses to supervisor pages */ 5008c50d8ae3SPaolo Bonzini u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; 5009c50d8ae3SPaolo Bonzini /* Faults from fetches of non-executable pages*/ 5010c50d8ae3SPaolo Bonzini u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; 5011c50d8ae3SPaolo Bonzini /* Faults from kernel mode fetches of user pages */ 5012c50d8ae3SPaolo Bonzini u8 smepf = 0; 5013c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses of user pages */ 5014c50d8ae3SPaolo Bonzini u8 smapf = 0; 5015c50d8ae3SPaolo Bonzini 5016c50d8ae3SPaolo Bonzini if (!ept) { 5017c50d8ae3SPaolo Bonzini /* Faults from kernel mode accesses to user pages */ 5018c50d8ae3SPaolo Bonzini u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u; 5019c50d8ae3SPaolo Bonzini 5020c50d8ae3SPaolo Bonzini /* Not really needed: !nx will cause pte.nx to fault */ 502190599c28SSean Christopherson if (!efer_nx) 5022c50d8ae3SPaolo Bonzini ff = 0; 5023c50d8ae3SPaolo Bonzini 5024c50d8ae3SPaolo Bonzini /* Allow supervisor writes if !cr0.wp */ 5025c50d8ae3SPaolo Bonzini if (!cr0_wp) 5026c50d8ae3SPaolo Bonzini wf = (pfec & PFERR_USER_MASK) ? wf : 0; 5027c50d8ae3SPaolo Bonzini 5028c50d8ae3SPaolo Bonzini /* Disallow supervisor fetches of user code if cr4.smep */ 5029c50d8ae3SPaolo Bonzini if (cr4_smep) 5030c50d8ae3SPaolo Bonzini smepf = (pfec & PFERR_FETCH_MASK) ? kf : 0; 5031c50d8ae3SPaolo Bonzini 5032c50d8ae3SPaolo Bonzini /* 5033c50d8ae3SPaolo Bonzini * SMAP:kernel-mode data accesses from user-mode 5034c50d8ae3SPaolo Bonzini * mappings should fault. A fault is considered 5035c50d8ae3SPaolo Bonzini * as a SMAP violation if all of the following 5036c50d8ae3SPaolo Bonzini * conditions are true: 5037c50d8ae3SPaolo Bonzini * - X86_CR4_SMAP is set in CR4 5038c50d8ae3SPaolo Bonzini * - A user page is accessed 5039c50d8ae3SPaolo Bonzini * - The access is not a fetch 50404f4aa80eSLai Jiangshan * - The access is supervisor mode 50414f4aa80eSLai Jiangshan * - If implicit supervisor access or X86_EFLAGS_AC is clear 5042c50d8ae3SPaolo Bonzini * 504394b4a2f1SLai Jiangshan * Here, we cover the first four conditions. 504494b4a2f1SLai Jiangshan * The fifth is computed dynamically in permission_fault(); 5045c50d8ae3SPaolo Bonzini * PFERR_RSVD_MASK bit will be set in PFEC if the access is 5046c50d8ae3SPaolo Bonzini * *not* subject to SMAP restrictions. 5047c50d8ae3SPaolo Bonzini */ 5048c50d8ae3SPaolo Bonzini if (cr4_smap) 5049c50d8ae3SPaolo Bonzini smapf = (pfec & (PFERR_RSVD_MASK|PFERR_FETCH_MASK)) ? 0 : kf; 5050c50d8ae3SPaolo Bonzini } 5051c50d8ae3SPaolo Bonzini 5052c50d8ae3SPaolo Bonzini mmu->permissions[byte] = ff | uf | wf | smepf | smapf; 5053c50d8ae3SPaolo Bonzini } 5054c50d8ae3SPaolo Bonzini } 5055c50d8ae3SPaolo Bonzini 5056c50d8ae3SPaolo Bonzini /* 5057c50d8ae3SPaolo Bonzini * PKU is an additional mechanism by which the paging controls access to 5058c50d8ae3SPaolo Bonzini * user-mode addresses based on the value in the PKRU register. Protection 5059c50d8ae3SPaolo Bonzini * key violations are reported through a bit in the page fault error code. 5060c50d8ae3SPaolo Bonzini * Unlike other bits of the error code, the PK bit is not known at the 5061c50d8ae3SPaolo Bonzini * call site of e.g. gva_to_gpa; it must be computed directly in 5062c50d8ae3SPaolo Bonzini * permission_fault based on two bits of PKRU, on some machine state (CR4, 5063c50d8ae3SPaolo Bonzini * CR0, EFER, CPL), and on other bits of the error code and the page tables. 5064c50d8ae3SPaolo Bonzini * 5065c50d8ae3SPaolo Bonzini * In particular the following conditions come from the error code, the 5066c50d8ae3SPaolo Bonzini * page tables and the machine state: 5067c50d8ae3SPaolo Bonzini * - PK is always zero unless CR4.PKE=1 and EFER.LMA=1 5068c50d8ae3SPaolo Bonzini * - PK is always zero if RSVD=1 (reserved bit set) or F=1 (instruction fetch) 5069c50d8ae3SPaolo Bonzini * - PK is always zero if U=0 in the page tables 5070c50d8ae3SPaolo Bonzini * - PKRU.WD is ignored if CR0.WP=0 and the access is a supervisor access. 5071c50d8ae3SPaolo Bonzini * 5072c50d8ae3SPaolo Bonzini * The PKRU bitmask caches the result of these four conditions. The error 5073c50d8ae3SPaolo Bonzini * code (minus the P bit) and the page table's U bit form an index into the 5074c50d8ae3SPaolo Bonzini * PKRU bitmask. Two bits of the PKRU bitmask are then extracted and ANDed 5075c50d8ae3SPaolo Bonzini * with the two bits of the PKRU register corresponding to the protection key. 5076c50d8ae3SPaolo Bonzini * For the first three conditions above the bits will be 00, thus masking 5077c50d8ae3SPaolo Bonzini * away both AD and WD. For all reads or if the last condition holds, WD 5078c50d8ae3SPaolo Bonzini * only will be masked away. 5079c50d8ae3SPaolo Bonzini */ 50802e4c0661SSean Christopherson static void update_pkru_bitmask(struct kvm_mmu *mmu) 5081c50d8ae3SPaolo Bonzini { 5082c50d8ae3SPaolo Bonzini unsigned bit; 5083c50d8ae3SPaolo Bonzini bool wp; 5084c50d8ae3SPaolo Bonzini 5085c50d8ae3SPaolo Bonzini mmu->pkru_mask = 0; 5086a3ca5281SChenyi Qiang 5087a3ca5281SChenyi Qiang if (!is_cr4_pke(mmu)) 5088c50d8ae3SPaolo Bonzini return; 5089c50d8ae3SPaolo Bonzini 50902e4c0661SSean Christopherson wp = is_cr0_wp(mmu); 5091c50d8ae3SPaolo Bonzini 5092c50d8ae3SPaolo Bonzini for (bit = 0; bit < ARRAY_SIZE(mmu->permissions); ++bit) { 5093c50d8ae3SPaolo Bonzini unsigned pfec, pkey_bits; 5094c50d8ae3SPaolo Bonzini bool check_pkey, check_write, ff, uf, wf, pte_user; 5095c50d8ae3SPaolo Bonzini 5096c50d8ae3SPaolo Bonzini pfec = bit << 1; 5097c50d8ae3SPaolo Bonzini ff = pfec & PFERR_FETCH_MASK; 5098c50d8ae3SPaolo Bonzini uf = pfec & PFERR_USER_MASK; 5099c50d8ae3SPaolo Bonzini wf = pfec & PFERR_WRITE_MASK; 5100c50d8ae3SPaolo Bonzini 5101c50d8ae3SPaolo Bonzini /* PFEC.RSVD is replaced by ACC_USER_MASK. */ 5102c50d8ae3SPaolo Bonzini pte_user = pfec & PFERR_RSVD_MASK; 5103c50d8ae3SPaolo Bonzini 5104c50d8ae3SPaolo Bonzini /* 5105c50d8ae3SPaolo Bonzini * Only need to check the access which is not an 5106c50d8ae3SPaolo Bonzini * instruction fetch and is to a user page. 5107c50d8ae3SPaolo Bonzini */ 5108c50d8ae3SPaolo Bonzini check_pkey = (!ff && pte_user); 5109c50d8ae3SPaolo Bonzini /* 5110c50d8ae3SPaolo Bonzini * write access is controlled by PKRU if it is a 5111c50d8ae3SPaolo Bonzini * user access or CR0.WP = 1. 5112c50d8ae3SPaolo Bonzini */ 5113c50d8ae3SPaolo Bonzini check_write = check_pkey && wf && (uf || wp); 5114c50d8ae3SPaolo Bonzini 5115c50d8ae3SPaolo Bonzini /* PKRU.AD stops both read and write access. */ 5116c50d8ae3SPaolo Bonzini pkey_bits = !!check_pkey; 5117c50d8ae3SPaolo Bonzini /* PKRU.WD stops write access. */ 5118c50d8ae3SPaolo Bonzini pkey_bits |= (!!check_write) << 1; 5119c50d8ae3SPaolo Bonzini 5120c50d8ae3SPaolo Bonzini mmu->pkru_mask |= (pkey_bits & 3) << pfec; 5121c50d8ae3SPaolo Bonzini } 5122c50d8ae3SPaolo Bonzini } 5123c50d8ae3SPaolo Bonzini 5124533f9a4bSSean Christopherson static void reset_guest_paging_metadata(struct kvm_vcpu *vcpu, 5125533f9a4bSSean Christopherson struct kvm_mmu *mmu) 5126c50d8ae3SPaolo Bonzini { 5127533f9a4bSSean Christopherson if (!is_cr0_pg(mmu)) 5128533f9a4bSSean Christopherson return; 5129c50d8ae3SPaolo Bonzini 5130c919e881SKai Huang reset_guest_rsvds_bits_mask(vcpu, mmu); 5131533f9a4bSSean Christopherson update_permission_bitmask(mmu, false); 5132533f9a4bSSean Christopherson update_pkru_bitmask(mmu); 5133c50d8ae3SPaolo Bonzini } 5134c50d8ae3SPaolo Bonzini 5135fe660f72SSean Christopherson static void paging64_init_context(struct kvm_mmu *context) 5136c50d8ae3SPaolo Bonzini { 5137c50d8ae3SPaolo Bonzini context->page_fault = paging64_page_fault; 5138c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5139c3c6c9fcSLai Jiangshan context->sync_spte = paging64_sync_spte; 5140c50d8ae3SPaolo Bonzini } 5141c50d8ae3SPaolo Bonzini 514284a16226SSean Christopherson static void paging32_init_context(struct kvm_mmu *context) 5143c50d8ae3SPaolo Bonzini { 5144c50d8ae3SPaolo Bonzini context->page_fault = paging32_page_fault; 5145c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5146c3c6c9fcSLai Jiangshan context->sync_spte = paging32_sync_spte; 5147c50d8ae3SPaolo Bonzini } 5148c50d8ae3SPaolo Bonzini 5149f3d90f90SSean Christopherson static union kvm_cpu_role kvm_calc_cpu_role(struct kvm_vcpu *vcpu, 5150f3d90f90SSean Christopherson const struct kvm_mmu_role_regs *regs) 5151e5ed0fb0SPaolo Bonzini { 51527a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5153e5ed0fb0SPaolo Bonzini 5154e5ed0fb0SPaolo Bonzini role.base.access = ACC_ALL; 5155e5ed0fb0SPaolo Bonzini role.base.smm = is_smm(vcpu); 5156e5ed0fb0SPaolo Bonzini role.base.guest_mode = is_guest_mode(vcpu); 5157e5ed0fb0SPaolo Bonzini role.ext.valid = 1; 5158e5ed0fb0SPaolo Bonzini 5159e5ed0fb0SPaolo Bonzini if (!____is_cr0_pg(regs)) { 5160e5ed0fb0SPaolo Bonzini role.base.direct = 1; 5161e5ed0fb0SPaolo Bonzini return role; 5162e5ed0fb0SPaolo Bonzini } 5163e5ed0fb0SPaolo Bonzini 5164e5ed0fb0SPaolo Bonzini role.base.efer_nx = ____is_efer_nx(regs); 5165e5ed0fb0SPaolo Bonzini role.base.cr0_wp = ____is_cr0_wp(regs); 5166e5ed0fb0SPaolo Bonzini role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs); 5167e5ed0fb0SPaolo Bonzini role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs); 5168e5ed0fb0SPaolo Bonzini role.base.has_4_byte_gpte = !____is_cr4_pae(regs); 516960f3cb60SPaolo Bonzini 517060f3cb60SPaolo Bonzini if (____is_efer_lma(regs)) 517160f3cb60SPaolo Bonzini role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL 517260f3cb60SPaolo Bonzini : PT64_ROOT_4LEVEL; 517360f3cb60SPaolo Bonzini else if (____is_cr4_pae(regs)) 517460f3cb60SPaolo Bonzini role.base.level = PT32E_ROOT_LEVEL; 517560f3cb60SPaolo Bonzini else 517660f3cb60SPaolo Bonzini role.base.level = PT32_ROOT_LEVEL; 5177e5ed0fb0SPaolo Bonzini 5178e5ed0fb0SPaolo Bonzini role.ext.cr4_smep = ____is_cr4_smep(regs); 5179e5ed0fb0SPaolo Bonzini role.ext.cr4_smap = ____is_cr4_smap(regs); 5180e5ed0fb0SPaolo Bonzini role.ext.cr4_pse = ____is_cr4_pse(regs); 5181e5ed0fb0SPaolo Bonzini 5182e5ed0fb0SPaolo Bonzini /* PKEY and LA57 are active iff long mode is active. */ 5183e5ed0fb0SPaolo Bonzini role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs); 5184e5ed0fb0SPaolo Bonzini role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs); 5185e5ed0fb0SPaolo Bonzini role.ext.efer_lma = ____is_efer_lma(regs); 5186e5ed0fb0SPaolo Bonzini return role; 5187e5ed0fb0SPaolo Bonzini } 5188e5ed0fb0SPaolo Bonzini 5189d468d94bSSean Christopherson static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) 5190d468d94bSSean Christopherson { 5191746700d2SWei Huang /* tdp_root_level is architecture forced level, use it if nonzero */ 5192746700d2SWei Huang if (tdp_root_level) 5193746700d2SWei Huang return tdp_root_level; 5194746700d2SWei Huang 5195d468d94bSSean Christopherson /* Use 5-level TDP if and only if it's useful/necessary. */ 519683013059SSean Christopherson if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48) 5197d468d94bSSean Christopherson return 4; 5198d468d94bSSean Christopherson 519983013059SSean Christopherson return max_tdp_level; 5200d468d94bSSean Christopherson } 5201d468d94bSSean Christopherson 52027a458f0eSPaolo Bonzini static union kvm_mmu_page_role 52038626c120SSean Christopherson kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, 52047a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role) 5205c50d8ae3SPaolo Bonzini { 52067a458f0eSPaolo Bonzini union kvm_mmu_page_role role = {0}; 5207c50d8ae3SPaolo Bonzini 52087a458f0eSPaolo Bonzini role.access = ACC_ALL; 52097a458f0eSPaolo Bonzini role.cr0_wp = true; 52107a458f0eSPaolo Bonzini role.efer_nx = true; 52117a458f0eSPaolo Bonzini role.smm = cpu_role.base.smm; 52127a458f0eSPaolo Bonzini role.guest_mode = cpu_role.base.guest_mode; 521354275f74SSean Christopherson role.ad_disabled = !kvm_ad_enabled(); 52147a458f0eSPaolo Bonzini role.level = kvm_mmu_get_tdp_level(vcpu); 52157a458f0eSPaolo Bonzini role.direct = true; 52167a458f0eSPaolo Bonzini role.has_4_byte_gpte = false; 5217c50d8ae3SPaolo Bonzini 5218c50d8ae3SPaolo Bonzini return role; 5219c50d8ae3SPaolo Bonzini } 5220c50d8ae3SPaolo Bonzini 522139e7e2bfSPaolo Bonzini static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, 5222a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5223c50d8ae3SPaolo Bonzini { 52248c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 52257a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role = kvm_calc_tdp_mmu_root_page_role(vcpu, cpu_role); 5226c50d8ae3SPaolo Bonzini 5227e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 52287a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 5229c50d8ae3SPaolo Bonzini return; 5230c50d8ae3SPaolo Bonzini 5231e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 52327a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 52337a02674dSSean Christopherson context->page_fault = kvm_tdp_page_fault; 5234c3c6c9fcSLai Jiangshan context->sync_spte = NULL; 5235*2fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5236c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5237c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5238c50d8ae3SPaolo Bonzini 523936f26787SSean Christopherson if (!is_cr0_pg(context)) 5240c50d8ae3SPaolo Bonzini context->gva_to_gpa = nonpaging_gva_to_gpa; 524136f26787SSean Christopherson else if (is_cr4_pae(context)) 5242c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging64_gva_to_gpa; 5243f4bd6f73SSean Christopherson else 5244c50d8ae3SPaolo Bonzini context->gva_to_gpa = paging32_gva_to_gpa; 5245c50d8ae3SPaolo Bonzini 5246533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5247e8f6e738SJinrong Liang reset_tdp_shadow_zero_bits_mask(context); 5248c50d8ae3SPaolo Bonzini } 5249c50d8ae3SPaolo Bonzini 52508c008659SPaolo Bonzini static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context, 52517a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role, 52527a458f0eSPaolo Bonzini union kvm_mmu_page_role root_role) 5253c50d8ae3SPaolo Bonzini { 5254e5ed0fb0SPaolo Bonzini if (cpu_role.as_u64 == context->cpu_role.as_u64 && 52557a458f0eSPaolo Bonzini root_role.word == context->root_role.word) 525618db1b17SSean Christopherson return; 5257c50d8ae3SPaolo Bonzini 5258e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = cpu_role.as_u64; 52597a458f0eSPaolo Bonzini context->root_role.word = root_role.word; 526018db1b17SSean Christopherson 526136f26787SSean Christopherson if (!is_cr0_pg(context)) 526284a16226SSean Christopherson nonpaging_init_context(context); 526336f26787SSean Christopherson else if (is_cr4_pae(context)) 5264fe660f72SSean Christopherson paging64_init_context(context); 5265c50d8ae3SPaolo Bonzini else 526684a16226SSean Christopherson paging32_init_context(context); 5267c50d8ae3SPaolo Bonzini 5268533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, context); 5269c50d8ae3SPaolo Bonzini reset_shadow_zero_bits_mask(vcpu, context); 5270c50d8ae3SPaolo Bonzini } 52710f04a2acSVitaly Kuznetsov 5272594e91a1SSean Christopherson static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, 5273a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 52740f04a2acSVitaly Kuznetsov { 52758c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 527656b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 527756b321f9SPaolo Bonzini 527856b321f9SPaolo Bonzini root_role = cpu_role.base; 527956b321f9SPaolo Bonzini 528056b321f9SPaolo Bonzini /* KVM uses PAE paging whenever the guest isn't using 64-bit paging. */ 528156b321f9SPaolo Bonzini root_role.level = max_t(u32, root_role.level, PT32E_ROOT_LEVEL); 528256b321f9SPaolo Bonzini 528356b321f9SPaolo Bonzini /* 528456b321f9SPaolo Bonzini * KVM forces EFER.NX=1 when TDP is disabled, reflect it in the MMU role. 528556b321f9SPaolo Bonzini * KVM uses NX when TDP is disabled to handle a variety of scenarios, 528656b321f9SPaolo Bonzini * notably for huge SPTEs if iTLB multi-hit mitigation is enabled and 528756b321f9SPaolo Bonzini * to generate correct permissions for CR0.WP=0/CR4.SMEP=1/EFER.NX=0. 528856b321f9SPaolo Bonzini * The iTLB multi-hit workaround can be toggled at any time, so assume 528956b321f9SPaolo Bonzini * NX can be used by any non-nested shadow MMU to avoid having to reset 529056b321f9SPaolo Bonzini * MMU contexts. 529156b321f9SPaolo Bonzini */ 529256b321f9SPaolo Bonzini root_role.efer_nx = true; 52930f04a2acSVitaly Kuznetsov 52947a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 52950f04a2acSVitaly Kuznetsov } 52960f04a2acSVitaly Kuznetsov 5297dbc4739bSSean Christopherson void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, 5298dbc4739bSSean Christopherson unsigned long cr4, u64 efer, gpa_t nested_cr3) 52990f04a2acSVitaly Kuznetsov { 53008c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5301594e91a1SSean Christopherson struct kvm_mmu_role_regs regs = { 5302594e91a1SSean Christopherson .cr0 = cr0, 530328f091bcSPaolo Bonzini .cr4 = cr4 & ~X86_CR4_PKE, 5304594e91a1SSean Christopherson .efer = efer, 5305594e91a1SSean Christopherson }; 53067a7ae829SPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 530756b321f9SPaolo Bonzini union kvm_mmu_page_role root_role; 530856b321f9SPaolo Bonzini 530956b321f9SPaolo Bonzini /* NPT requires CR0.PG=1. */ 531056b321f9SPaolo Bonzini WARN_ON_ONCE(cpu_role.base.direct); 531156b321f9SPaolo Bonzini 531256b321f9SPaolo Bonzini root_role = cpu_role.base; 531356b321f9SPaolo Bonzini root_role.level = kvm_mmu_get_tdp_level(vcpu); 531484e5ffd0SLai Jiangshan if (root_role.level == PT64_ROOT_5LEVEL && 531584e5ffd0SLai Jiangshan cpu_role.base.level == PT64_ROOT_4LEVEL) 531684e5ffd0SLai Jiangshan root_role.passthrough = 1; 53170f04a2acSVitaly Kuznetsov 53187a458f0eSPaolo Bonzini shadow_mmu_init_context(vcpu, context, cpu_role, root_role); 5319d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, nested_cr3); 53200f04a2acSVitaly Kuznetsov } 53210f04a2acSVitaly Kuznetsov EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); 5322c50d8ae3SPaolo Bonzini 53237a7ae829SPaolo Bonzini static union kvm_cpu_role 5324c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty, 5325bb1fcc70SSean Christopherson bool execonly, u8 level) 5326c50d8ae3SPaolo Bonzini { 53277a7ae829SPaolo Bonzini union kvm_cpu_role role = {0}; 5328c50d8ae3SPaolo Bonzini 5329daed87b8SPaolo Bonzini /* 5330daed87b8SPaolo Bonzini * KVM does not support SMM transfer monitors, and consequently does not 5331daed87b8SPaolo Bonzini * support the "entry to SMM" control either. role.base.smm is always 0. 5332daed87b8SPaolo Bonzini */ 5333daed87b8SPaolo Bonzini WARN_ON_ONCE(is_smm(vcpu)); 5334bb1fcc70SSean Christopherson role.base.level = level; 5335bb3b394dSLai Jiangshan role.base.has_4_byte_gpte = false; 5336c50d8ae3SPaolo Bonzini role.base.direct = false; 5337c50d8ae3SPaolo Bonzini role.base.ad_disabled = !accessed_dirty; 5338c50d8ae3SPaolo Bonzini role.base.guest_mode = true; 5339c50d8ae3SPaolo Bonzini role.base.access = ACC_ALL; 5340c50d8ae3SPaolo Bonzini 5341cd6767c3SSean Christopherson role.ext.word = 0; 5342c50d8ae3SPaolo Bonzini role.ext.execonly = execonly; 5343cd6767c3SSean Christopherson role.ext.valid = 1; 5344c50d8ae3SPaolo Bonzini 5345c50d8ae3SPaolo Bonzini return role; 5346c50d8ae3SPaolo Bonzini } 5347c50d8ae3SPaolo Bonzini 5348c50d8ae3SPaolo Bonzini void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 5349cc022ae1SLai Jiangshan int huge_page_level, bool accessed_dirty, 5350cc022ae1SLai Jiangshan gpa_t new_eptp) 5351c50d8ae3SPaolo Bonzini { 53528c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.guest_mmu; 5353bb1fcc70SSean Christopherson u8 level = vmx_eptp_page_walk_level(new_eptp); 53547a7ae829SPaolo Bonzini union kvm_cpu_role new_mode = 5355c50d8ae3SPaolo Bonzini kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty, 5356bb1fcc70SSean Christopherson execonly, level); 5357c50d8ae3SPaolo Bonzini 5358e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 != context->cpu_role.as_u64) { 5359e5ed0fb0SPaolo Bonzini /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */ 5360e5ed0fb0SPaolo Bonzini context->cpu_role.as_u64 = new_mode.as_u64; 53617a458f0eSPaolo Bonzini context->root_role.word = new_mode.base.word; 536218db1b17SSean Christopherson 5363c50d8ae3SPaolo Bonzini context->page_fault = ept_page_fault; 5364c50d8ae3SPaolo Bonzini context->gva_to_gpa = ept_gva_to_gpa; 5365c3c6c9fcSLai Jiangshan context->sync_spte = ept_sync_spte; 5366347a0d0dSPaolo Bonzini 5367c596f147SSean Christopherson update_permission_bitmask(context, true); 536828f091bcSPaolo Bonzini context->pkru_mask = 0; 5369cc022ae1SLai Jiangshan reset_rsvds_bits_mask_ept(vcpu, context, execonly, huge_page_level); 5370e8f6e738SJinrong Liang reset_ept_shadow_zero_bits_mask(context, execonly); 5371c50d8ae3SPaolo Bonzini } 53723cffc89dSPaolo Bonzini 5373d2e5f333SPaolo Bonzini kvm_mmu_new_pgd(vcpu, new_eptp); 53743cffc89dSPaolo Bonzini } 5375c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); 5376c50d8ae3SPaolo Bonzini 537739e7e2bfSPaolo Bonzini static void init_kvm_softmmu(struct kvm_vcpu *vcpu, 5378a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role) 5379c50d8ae3SPaolo Bonzini { 53808c008659SPaolo Bonzini struct kvm_mmu *context = &vcpu->arch.root_mmu; 5381c50d8ae3SPaolo Bonzini 5382a7f1de9bSPaolo Bonzini kvm_init_shadow_mmu(vcpu, cpu_role); 5383929d1cfaSPaolo Bonzini 5384*2fdcc1b3SPaolo Bonzini context->get_guest_pgd = get_guest_cr3; 5385c50d8ae3SPaolo Bonzini context->get_pdptr = kvm_pdptr_read; 5386c50d8ae3SPaolo Bonzini context->inject_page_fault = kvm_inject_page_fault; 5387c50d8ae3SPaolo Bonzini } 5388c50d8ae3SPaolo Bonzini 538939e7e2bfSPaolo Bonzini static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, 5390a7f1de9bSPaolo Bonzini union kvm_cpu_role new_mode) 5391c50d8ae3SPaolo Bonzini { 5392c50d8ae3SPaolo Bonzini struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; 5393c50d8ae3SPaolo Bonzini 5394e5ed0fb0SPaolo Bonzini if (new_mode.as_u64 == g_context->cpu_role.as_u64) 5395c50d8ae3SPaolo Bonzini return; 5396c50d8ae3SPaolo Bonzini 5397e5ed0fb0SPaolo Bonzini g_context->cpu_role.as_u64 = new_mode.as_u64; 5398*2fdcc1b3SPaolo Bonzini g_context->get_guest_pgd = get_guest_cr3; 5399c50d8ae3SPaolo Bonzini g_context->get_pdptr = kvm_pdptr_read; 5400c50d8ae3SPaolo Bonzini g_context->inject_page_fault = kvm_inject_page_fault; 5401c50d8ae3SPaolo Bonzini 5402c50d8ae3SPaolo Bonzini /* 54035efac074SPaolo Bonzini * L2 page tables are never shadowed, so there is no need to sync 54045efac074SPaolo Bonzini * SPTEs. 54055efac074SPaolo Bonzini */ 54069fd4a4e3SLai Jiangshan g_context->sync_spte = NULL; 54075efac074SPaolo Bonzini 54085efac074SPaolo Bonzini /* 5409c50d8ae3SPaolo Bonzini * Note that arch.mmu->gva_to_gpa translates l2_gpa to l1_gpa using 5410c50d8ae3SPaolo Bonzini * L1's nested page tables (e.g. EPT12). The nested translation 5411c50d8ae3SPaolo Bonzini * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using 5412c50d8ae3SPaolo Bonzini * L2's page tables as the first level of translation and L1's 5413c50d8ae3SPaolo Bonzini * nested page tables as the second level of translation. Basically 5414c50d8ae3SPaolo Bonzini * the gva_to_gpa functions between mmu and nested_mmu are swapped. 5415c50d8ae3SPaolo Bonzini */ 5416fa4b5588SSean Christopherson if (!is_paging(vcpu)) 54171f5a21eeSLai Jiangshan g_context->gva_to_gpa = nonpaging_gva_to_gpa; 5418fa4b5588SSean Christopherson else if (is_long_mode(vcpu)) 54191f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5420fa4b5588SSean Christopherson else if (is_pae(vcpu)) 54211f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging64_gva_to_gpa; 5422fa4b5588SSean Christopherson else 54231f5a21eeSLai Jiangshan g_context->gva_to_gpa = paging32_gva_to_gpa; 5424fa4b5588SSean Christopherson 5425533f9a4bSSean Christopherson reset_guest_paging_metadata(vcpu, g_context); 5426c50d8ae3SPaolo Bonzini } 5427c50d8ae3SPaolo Bonzini 5428c9060662SSean Christopherson void kvm_init_mmu(struct kvm_vcpu *vcpu) 5429c50d8ae3SPaolo Bonzini { 543039e7e2bfSPaolo Bonzini struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu); 5431a7f1de9bSPaolo Bonzini union kvm_cpu_role cpu_role = kvm_calc_cpu_role(vcpu, ®s); 543239e7e2bfSPaolo Bonzini 5433c50d8ae3SPaolo Bonzini if (mmu_is_nested(vcpu)) 5434a7f1de9bSPaolo Bonzini init_kvm_nested_mmu(vcpu, cpu_role); 5435c50d8ae3SPaolo Bonzini else if (tdp_enabled) 5436a7f1de9bSPaolo Bonzini init_kvm_tdp_mmu(vcpu, cpu_role); 5437c50d8ae3SPaolo Bonzini else 5438a7f1de9bSPaolo Bonzini init_kvm_softmmu(vcpu, cpu_role); 5439c50d8ae3SPaolo Bonzini } 5440c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_init_mmu); 5441c50d8ae3SPaolo Bonzini 544249c6f875SSean Christopherson void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu) 544349c6f875SSean Christopherson { 544449c6f875SSean Christopherson /* 544549c6f875SSean Christopherson * Invalidate all MMU roles to force them to reinitialize as CPUID 544649c6f875SSean Christopherson * information is factored into reserved bit calculations. 5447feb627e8SVitaly Kuznetsov * 5448feb627e8SVitaly Kuznetsov * Correctly handling multiple vCPU models with respect to paging and 5449feb627e8SVitaly Kuznetsov * physical address properties) in a single VM would require tracking 5450feb627e8SVitaly Kuznetsov * all relevant CPUID information in kvm_mmu_page_role. That is very 5451feb627e8SVitaly Kuznetsov * undesirable as it would increase the memory requirements for 5452feb627e8SVitaly Kuznetsov * gfn_track (see struct kvm_mmu_page_role comments). For now that 5453feb627e8SVitaly Kuznetsov * problem is swept under the rug; KVM's CPUID API is horrific and 5454feb627e8SVitaly Kuznetsov * it's all but impossible to solve it without introducing a new API. 545549c6f875SSean Christopherson */ 54567a458f0eSPaolo Bonzini vcpu->arch.root_mmu.root_role.word = 0; 54577a458f0eSPaolo Bonzini vcpu->arch.guest_mmu.root_role.word = 0; 54587a458f0eSPaolo Bonzini vcpu->arch.nested_mmu.root_role.word = 0; 5459e5ed0fb0SPaolo Bonzini vcpu->arch.root_mmu.cpu_role.ext.valid = 0; 5460e5ed0fb0SPaolo Bonzini vcpu->arch.guest_mmu.cpu_role.ext.valid = 0; 5461e5ed0fb0SPaolo Bonzini vcpu->arch.nested_mmu.cpu_role.ext.valid = 0; 546249c6f875SSean Christopherson kvm_mmu_reset_context(vcpu); 546363f5a190SSean Christopherson 546463f5a190SSean Christopherson /* 5465feb627e8SVitaly Kuznetsov * Changing guest CPUID after KVM_RUN is forbidden, see the comment in 5466feb627e8SVitaly Kuznetsov * kvm_arch_vcpu_ioctl(). 546763f5a190SSean Christopherson */ 5468feb627e8SVitaly Kuznetsov KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm); 546949c6f875SSean Christopherson } 547049c6f875SSean Christopherson 5471c50d8ae3SPaolo Bonzini void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 5472c50d8ae3SPaolo Bonzini { 5473c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 5474c9060662SSean Christopherson kvm_init_mmu(vcpu); 5475c50d8ae3SPaolo Bonzini } 5476c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); 5477c50d8ae3SPaolo Bonzini 5478c50d8ae3SPaolo Bonzini int kvm_mmu_load(struct kvm_vcpu *vcpu) 5479c50d8ae3SPaolo Bonzini { 5480c50d8ae3SPaolo Bonzini int r; 5481c50d8ae3SPaolo Bonzini 5482347a0d0dSPaolo Bonzini r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->root_role.direct); 5483c50d8ae3SPaolo Bonzini if (r) 5484c50d8ae3SPaolo Bonzini goto out; 5485748e52b9SSean Christopherson r = mmu_alloc_special_roots(vcpu); 5486c50d8ae3SPaolo Bonzini if (r) 5487c50d8ae3SPaolo Bonzini goto out; 5488347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct) 54896e6ec584SSean Christopherson r = mmu_alloc_direct_roots(vcpu); 54906e6ec584SSean Christopherson else 54916e6ec584SSean Christopherson r = mmu_alloc_shadow_roots(vcpu); 5492c50d8ae3SPaolo Bonzini if (r) 5493c50d8ae3SPaolo Bonzini goto out; 5494a91f387bSSean Christopherson 5495a91f387bSSean Christopherson kvm_mmu_sync_roots(vcpu); 5496a91f387bSSean Christopherson 5497727a7e27SPaolo Bonzini kvm_mmu_load_pgd(vcpu); 5498db01416bSSean Christopherson 5499db01416bSSean Christopherson /* 5500db01416bSSean Christopherson * Flush any TLB entries for the new root, the provenance of the root 5501db01416bSSean Christopherson * is unknown. Even if KVM ensures there are no stale TLB entries 5502db01416bSSean Christopherson * for a freed root, in theory another hypervisor could have left 5503db01416bSSean Christopherson * stale entries. Flushing on alloc also allows KVM to skip the TLB 5504db01416bSSean Christopherson * flush when freeing a root (see kvm_tdp_mmu_put_root()). 5505db01416bSSean Christopherson */ 5506e27bc044SSean Christopherson static_call(kvm_x86_flush_tlb_current)(vcpu); 5507c50d8ae3SPaolo Bonzini out: 5508c50d8ae3SPaolo Bonzini return r; 5509c50d8ae3SPaolo Bonzini } 5510c50d8ae3SPaolo Bonzini 5511c50d8ae3SPaolo Bonzini void kvm_mmu_unload(struct kvm_vcpu *vcpu) 5512c50d8ae3SPaolo Bonzini { 55130c1c92f1SPaolo Bonzini struct kvm *kvm = vcpu->kvm; 55140c1c92f1SPaolo Bonzini 55150c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL); 5516b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root.hpa)); 55170c1c92f1SPaolo Bonzini kvm_mmu_free_roots(kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); 5518b9e5603cSPaolo Bonzini WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root.hpa)); 55196d58f275SPaolo Bonzini vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); 5520c50d8ae3SPaolo Bonzini } 5521c50d8ae3SPaolo Bonzini 5522527d5cd7SSean Christopherson static bool is_obsolete_root(struct kvm *kvm, hpa_t root_hpa) 5523527d5cd7SSean Christopherson { 5524527d5cd7SSean Christopherson struct kvm_mmu_page *sp; 5525527d5cd7SSean Christopherson 5526527d5cd7SSean Christopherson if (!VALID_PAGE(root_hpa)) 5527527d5cd7SSean Christopherson return false; 5528527d5cd7SSean Christopherson 5529527d5cd7SSean Christopherson /* 5530527d5cd7SSean Christopherson * When freeing obsolete roots, treat roots as obsolete if they don't 5531527d5cd7SSean Christopherson * have an associated shadow page. This does mean KVM will get false 5532527d5cd7SSean Christopherson * positives and free roots that don't strictly need to be freed, but 5533527d5cd7SSean Christopherson * such false positives are relatively rare: 5534527d5cd7SSean Christopherson * 5535527d5cd7SSean Christopherson * (a) only PAE paging and nested NPT has roots without shadow pages 5536527d5cd7SSean Christopherson * (b) remote reloads due to a memslot update obsoletes _all_ roots 5537527d5cd7SSean Christopherson * (c) KVM doesn't track previous roots for PAE paging, and the guest 5538527d5cd7SSean Christopherson * is unlikely to zap an in-use PGD. 5539527d5cd7SSean Christopherson */ 5540527d5cd7SSean Christopherson sp = to_shadow_page(root_hpa); 5541527d5cd7SSean Christopherson return !sp || is_obsolete_sp(kvm, sp); 5542527d5cd7SSean Christopherson } 5543527d5cd7SSean Christopherson 5544527d5cd7SSean Christopherson static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu) 5545527d5cd7SSean Christopherson { 5546527d5cd7SSean Christopherson unsigned long roots_to_free = 0; 5547527d5cd7SSean Christopherson int i; 5548527d5cd7SSean Christopherson 5549527d5cd7SSean Christopherson if (is_obsolete_root(kvm, mmu->root.hpa)) 5550527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_CURRENT; 5551527d5cd7SSean Christopherson 5552527d5cd7SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5553cf4a8693SShaoqin Huang if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa)) 5554527d5cd7SSean Christopherson roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i); 5555527d5cd7SSean Christopherson } 5556527d5cd7SSean Christopherson 5557527d5cd7SSean Christopherson if (roots_to_free) 5558527d5cd7SSean Christopherson kvm_mmu_free_roots(kvm, mmu, roots_to_free); 5559527d5cd7SSean Christopherson } 5560527d5cd7SSean Christopherson 5561527d5cd7SSean Christopherson void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu) 5562527d5cd7SSean Christopherson { 5563527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu); 5564527d5cd7SSean Christopherson __kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu); 5565527d5cd7SSean Christopherson } 5566527d5cd7SSean Christopherson 5567c50d8ae3SPaolo Bonzini static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, 5568c50d8ae3SPaolo Bonzini int *bytes) 5569c50d8ae3SPaolo Bonzini { 5570c50d8ae3SPaolo Bonzini u64 gentry = 0; 5571c50d8ae3SPaolo Bonzini int r; 5572c50d8ae3SPaolo Bonzini 5573c50d8ae3SPaolo Bonzini /* 5574c50d8ae3SPaolo Bonzini * Assume that the pte write on a page table of the same type 5575c50d8ae3SPaolo Bonzini * as the current vcpu paging mode since we update the sptes only 5576c50d8ae3SPaolo Bonzini * when they have the same mode. 5577c50d8ae3SPaolo Bonzini */ 5578c50d8ae3SPaolo Bonzini if (is_pae(vcpu) && *bytes == 4) { 5579c50d8ae3SPaolo Bonzini /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ 5580c50d8ae3SPaolo Bonzini *gpa &= ~(gpa_t)7; 5581c50d8ae3SPaolo Bonzini *bytes = 8; 5582c50d8ae3SPaolo Bonzini } 5583c50d8ae3SPaolo Bonzini 5584c50d8ae3SPaolo Bonzini if (*bytes == 4 || *bytes == 8) { 5585c50d8ae3SPaolo Bonzini r = kvm_vcpu_read_guest_atomic(vcpu, *gpa, &gentry, *bytes); 5586c50d8ae3SPaolo Bonzini if (r) 5587c50d8ae3SPaolo Bonzini gentry = 0; 5588c50d8ae3SPaolo Bonzini } 5589c50d8ae3SPaolo Bonzini 5590c50d8ae3SPaolo Bonzini return gentry; 5591c50d8ae3SPaolo Bonzini } 5592c50d8ae3SPaolo Bonzini 5593c50d8ae3SPaolo Bonzini /* 5594c50d8ae3SPaolo Bonzini * If we're seeing too many writes to a page, it may no longer be a page table, 5595c50d8ae3SPaolo Bonzini * or we may be forking, in which case it is better to unmap the page. 5596c50d8ae3SPaolo Bonzini */ 5597c50d8ae3SPaolo Bonzini static bool detect_write_flooding(struct kvm_mmu_page *sp) 5598c50d8ae3SPaolo Bonzini { 5599c50d8ae3SPaolo Bonzini /* 5600c50d8ae3SPaolo Bonzini * Skip write-flooding detected for the sp whose level is 1, because 5601c50d8ae3SPaolo Bonzini * it can become unsync, then the guest page is not write-protected. 5602c50d8ae3SPaolo Bonzini */ 56033bae0459SSean Christopherson if (sp->role.level == PG_LEVEL_4K) 5604c50d8ae3SPaolo Bonzini return false; 5605c50d8ae3SPaolo Bonzini 5606c50d8ae3SPaolo Bonzini atomic_inc(&sp->write_flooding_count); 5607c50d8ae3SPaolo Bonzini return atomic_read(&sp->write_flooding_count) >= 3; 5608c50d8ae3SPaolo Bonzini } 5609c50d8ae3SPaolo Bonzini 5610c50d8ae3SPaolo Bonzini /* 5611c50d8ae3SPaolo Bonzini * Misaligned accesses are too much trouble to fix up; also, they usually 5612c50d8ae3SPaolo Bonzini * indicate a page is not used as a page table. 5613c50d8ae3SPaolo Bonzini */ 5614c50d8ae3SPaolo Bonzini static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa, 5615c50d8ae3SPaolo Bonzini int bytes) 5616c50d8ae3SPaolo Bonzini { 5617c50d8ae3SPaolo Bonzini unsigned offset, pte_size, misaligned; 5618c50d8ae3SPaolo Bonzini 5619c50d8ae3SPaolo Bonzini pgprintk("misaligned: gpa %llx bytes %d role %x\n", 5620c50d8ae3SPaolo Bonzini gpa, bytes, sp->role.word); 5621c50d8ae3SPaolo Bonzini 5622c50d8ae3SPaolo Bonzini offset = offset_in_page(gpa); 5623bb3b394dSLai Jiangshan pte_size = sp->role.has_4_byte_gpte ? 4 : 8; 5624c50d8ae3SPaolo Bonzini 5625c50d8ae3SPaolo Bonzini /* 5626c50d8ae3SPaolo Bonzini * Sometimes, the OS only writes the last one bytes to update status 5627c50d8ae3SPaolo Bonzini * bits, for example, in linux, andb instruction is used in clear_bit(). 5628c50d8ae3SPaolo Bonzini */ 5629c50d8ae3SPaolo Bonzini if (!(offset & (pte_size - 1)) && bytes == 1) 5630c50d8ae3SPaolo Bonzini return false; 5631c50d8ae3SPaolo Bonzini 5632c50d8ae3SPaolo Bonzini misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); 5633c50d8ae3SPaolo Bonzini misaligned |= bytes < 4; 5634c50d8ae3SPaolo Bonzini 5635c50d8ae3SPaolo Bonzini return misaligned; 5636c50d8ae3SPaolo Bonzini } 5637c50d8ae3SPaolo Bonzini 5638c50d8ae3SPaolo Bonzini static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) 5639c50d8ae3SPaolo Bonzini { 5640c50d8ae3SPaolo Bonzini unsigned page_offset, quadrant; 5641c50d8ae3SPaolo Bonzini u64 *spte; 5642c50d8ae3SPaolo Bonzini int level; 5643c50d8ae3SPaolo Bonzini 5644c50d8ae3SPaolo Bonzini page_offset = offset_in_page(gpa); 5645c50d8ae3SPaolo Bonzini level = sp->role.level; 5646c50d8ae3SPaolo Bonzini *nspte = 1; 5647bb3b394dSLai Jiangshan if (sp->role.has_4_byte_gpte) { 5648c50d8ae3SPaolo Bonzini page_offset <<= 1; /* 32->64 */ 5649c50d8ae3SPaolo Bonzini /* 5650c50d8ae3SPaolo Bonzini * A 32-bit pde maps 4MB while the shadow pdes map 5651c50d8ae3SPaolo Bonzini * only 2MB. So we need to double the offset again 5652c50d8ae3SPaolo Bonzini * and zap two pdes instead of one. 5653c50d8ae3SPaolo Bonzini */ 5654c50d8ae3SPaolo Bonzini if (level == PT32_ROOT_LEVEL) { 5655c50d8ae3SPaolo Bonzini page_offset &= ~7; /* kill rounding error */ 5656c50d8ae3SPaolo Bonzini page_offset <<= 1; 5657c50d8ae3SPaolo Bonzini *nspte = 2; 5658c50d8ae3SPaolo Bonzini } 5659c50d8ae3SPaolo Bonzini quadrant = page_offset >> PAGE_SHIFT; 5660c50d8ae3SPaolo Bonzini page_offset &= ~PAGE_MASK; 5661c50d8ae3SPaolo Bonzini if (quadrant != sp->role.quadrant) 5662c50d8ae3SPaolo Bonzini return NULL; 5663c50d8ae3SPaolo Bonzini } 5664c50d8ae3SPaolo Bonzini 5665c50d8ae3SPaolo Bonzini spte = &sp->spt[page_offset / sizeof(*spte)]; 5666c50d8ae3SPaolo Bonzini return spte; 5667c50d8ae3SPaolo Bonzini } 5668c50d8ae3SPaolo Bonzini 5669c50d8ae3SPaolo Bonzini static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 5670c50d8ae3SPaolo Bonzini const u8 *new, int bytes, 5671c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 5672c50d8ae3SPaolo Bonzini { 5673c50d8ae3SPaolo Bonzini gfn_t gfn = gpa >> PAGE_SHIFT; 5674c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 5675c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 5676c50d8ae3SPaolo Bonzini u64 entry, gentry, *spte; 5677c50d8ae3SPaolo Bonzini int npte; 567806152b2dSLai Jiangshan bool flush = false; 5679c50d8ae3SPaolo Bonzini 5680c50d8ae3SPaolo Bonzini /* 5681c50d8ae3SPaolo Bonzini * If we don't have indirect shadow pages, it means no page is 5682c50d8ae3SPaolo Bonzini * write-protected, so we can exit simply. 5683c50d8ae3SPaolo Bonzini */ 5684c50d8ae3SPaolo Bonzini if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) 5685c50d8ae3SPaolo Bonzini return; 5686c50d8ae3SPaolo Bonzini 5687c50d8ae3SPaolo Bonzini pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); 5688c50d8ae3SPaolo Bonzini 5689531810caSBen Gardon write_lock(&vcpu->kvm->mmu_lock); 5690c50d8ae3SPaolo Bonzini 5691c50d8ae3SPaolo Bonzini gentry = mmu_pte_write_fetch_gpte(vcpu, &gpa, &bytes); 5692c50d8ae3SPaolo Bonzini 5693c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_pte_write; 5694c50d8ae3SPaolo Bonzini 5695767d8d8dSLai Jiangshan for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) { 5696c50d8ae3SPaolo Bonzini if (detect_write_misaligned(sp, gpa, bytes) || 5697c50d8ae3SPaolo Bonzini detect_write_flooding(sp)) { 5698c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); 5699c50d8ae3SPaolo Bonzini ++vcpu->kvm->stat.mmu_flooded; 5700c50d8ae3SPaolo Bonzini continue; 5701c50d8ae3SPaolo Bonzini } 5702c50d8ae3SPaolo Bonzini 5703c50d8ae3SPaolo Bonzini spte = get_written_sptes(sp, gpa, &npte); 5704c50d8ae3SPaolo Bonzini if (!spte) 5705c50d8ae3SPaolo Bonzini continue; 5706c50d8ae3SPaolo Bonzini 5707c50d8ae3SPaolo Bonzini while (npte--) { 5708c50d8ae3SPaolo Bonzini entry = *spte; 57092de4085cSBen Gardon mmu_page_zap_pte(vcpu->kvm, sp, spte, NULL); 5710c5e2184dSSean Christopherson if (gentry && sp->role.level != PG_LEVEL_4K) 5711c5e2184dSSean Christopherson ++vcpu->kvm->stat.mmu_pde_zapped; 57121441ca14SJunaid Shahid if (is_shadow_present_pte(entry)) 571306152b2dSLai Jiangshan flush = true; 5714c50d8ae3SPaolo Bonzini ++spte; 5715c50d8ae3SPaolo Bonzini } 5716c50d8ae3SPaolo Bonzini } 571706152b2dSLai Jiangshan kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, flush); 5718531810caSBen Gardon write_unlock(&vcpu->kvm->mmu_lock); 5719c50d8ae3SPaolo Bonzini } 5720c50d8ae3SPaolo Bonzini 57211075d41eSSean Christopherson int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, 5722c50d8ae3SPaolo Bonzini void *insn, int insn_len) 5723c50d8ae3SPaolo Bonzini { 572492daa48bSSean Christopherson int r, emulation_type = EMULTYPE_PF; 5725347a0d0dSPaolo Bonzini bool direct = vcpu->arch.mmu->root_role.direct; 5726c50d8ae3SPaolo Bonzini 5727b9e5603cSPaolo Bonzini if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) 5728ddce6208SSean Christopherson return RET_PF_RETRY; 5729ddce6208SSean Christopherson 5730c50d8ae3SPaolo Bonzini r = RET_PF_INVALID; 5731c50d8ae3SPaolo Bonzini if (unlikely(error_code & PFERR_RSVD_MASK)) { 5732736c291cSSean Christopherson r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct); 5733c50d8ae3SPaolo Bonzini if (r == RET_PF_EMULATE) 5734c50d8ae3SPaolo Bonzini goto emulate; 5735c50d8ae3SPaolo Bonzini } 5736c50d8ae3SPaolo Bonzini 5737c50d8ae3SPaolo Bonzini if (r == RET_PF_INVALID) { 57387a02674dSSean Christopherson r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, 5739258d985fSSean Christopherson lower_32_bits(error_code), false, 5740258d985fSSean Christopherson &emulation_type); 574119025e7bSSean Christopherson if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm)) 57427b367bc9SSean Christopherson return -EIO; 5743c50d8ae3SPaolo Bonzini } 5744c50d8ae3SPaolo Bonzini 5745c50d8ae3SPaolo Bonzini if (r < 0) 5746c50d8ae3SPaolo Bonzini return r; 574783a2ba4cSSean Christopherson if (r != RET_PF_EMULATE) 574883a2ba4cSSean Christopherson return 1; 5749c50d8ae3SPaolo Bonzini 5750c50d8ae3SPaolo Bonzini /* 5751c50d8ae3SPaolo Bonzini * Before emulating the instruction, check if the error code 5752c50d8ae3SPaolo Bonzini * was due to a RO violation while translating the guest page. 5753c50d8ae3SPaolo Bonzini * This can occur when using nested virtualization with nested 5754c50d8ae3SPaolo Bonzini * paging in both guests. If true, we simply unprotect the page 5755c50d8ae3SPaolo Bonzini * and resume the guest. 5756c50d8ae3SPaolo Bonzini */ 5757347a0d0dSPaolo Bonzini if (vcpu->arch.mmu->root_role.direct && 5758c50d8ae3SPaolo Bonzini (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) { 5759736c291cSSean Christopherson kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa)); 5760c50d8ae3SPaolo Bonzini return 1; 5761c50d8ae3SPaolo Bonzini } 5762c50d8ae3SPaolo Bonzini 5763c50d8ae3SPaolo Bonzini /* 5764c50d8ae3SPaolo Bonzini * vcpu->arch.mmu.page_fault returned RET_PF_EMULATE, but we can still 5765c50d8ae3SPaolo Bonzini * optimistically try to just unprotect the page and let the processor 5766c50d8ae3SPaolo Bonzini * re-execute the instruction that caused the page fault. Do not allow 5767c50d8ae3SPaolo Bonzini * retrying MMIO emulation, as it's not only pointless but could also 5768c50d8ae3SPaolo Bonzini * cause us to enter an infinite loop because the processor will keep 5769c50d8ae3SPaolo Bonzini * faulting on the non-existent MMIO address. Retrying an instruction 5770c50d8ae3SPaolo Bonzini * from a nested guest is also pointless and dangerous as we are only 5771c50d8ae3SPaolo Bonzini * explicitly shadowing L1's page tables, i.e. unprotecting something 5772c50d8ae3SPaolo Bonzini * for L1 isn't going to magically fix whatever issue cause L2 to fail. 5773c50d8ae3SPaolo Bonzini */ 5774736c291cSSean Christopherson if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu)) 577592daa48bSSean Christopherson emulation_type |= EMULTYPE_ALLOW_RETRY_PF; 5776c50d8ae3SPaolo Bonzini emulate: 5777736c291cSSean Christopherson return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn, 5778c50d8ae3SPaolo Bonzini insn_len); 5779c50d8ae3SPaolo Bonzini } 5780c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); 5781c50d8ae3SPaolo Bonzini 57829fd4a4e3SLai Jiangshan static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 57839fd4a4e3SLai Jiangshan u64 addr, hpa_t root_hpa) 57849fd4a4e3SLai Jiangshan { 57859fd4a4e3SLai Jiangshan struct kvm_shadow_walk_iterator iterator; 57869fd4a4e3SLai Jiangshan 57879fd4a4e3SLai Jiangshan vcpu_clear_mmio_info(vcpu, addr); 57889fd4a4e3SLai Jiangshan 57899fd4a4e3SLai Jiangshan if (!VALID_PAGE(root_hpa)) 57909fd4a4e3SLai Jiangshan return; 57919fd4a4e3SLai Jiangshan 57929fd4a4e3SLai Jiangshan write_lock(&vcpu->kvm->mmu_lock); 57939fd4a4e3SLai Jiangshan for_each_shadow_entry_using_root(vcpu, root_hpa, addr, iterator) { 57949fd4a4e3SLai Jiangshan struct kvm_mmu_page *sp = sptep_to_sp(iterator.sptep); 57959fd4a4e3SLai Jiangshan 57969fd4a4e3SLai Jiangshan if (sp->unsync) { 579719ace7d6SLai Jiangshan int ret = kvm_sync_spte(vcpu, sp, iterator.index); 57989fd4a4e3SLai Jiangshan 57999fd4a4e3SLai Jiangshan if (ret < 0) 58009fd4a4e3SLai Jiangshan mmu_page_zap_pte(vcpu->kvm, sp, iterator.sptep, NULL); 58019fd4a4e3SLai Jiangshan if (ret) 58029fd4a4e3SLai Jiangshan kvm_flush_remote_tlbs_sptep(vcpu->kvm, iterator.sptep); 58039fd4a4e3SLai Jiangshan } 58049fd4a4e3SLai Jiangshan 58059fd4a4e3SLai Jiangshan if (!sp->unsync_children) 58069fd4a4e3SLai Jiangshan break; 58079fd4a4e3SLai Jiangshan } 58089fd4a4e3SLai Jiangshan write_unlock(&vcpu->kvm->mmu_lock); 58099fd4a4e3SLai Jiangshan } 58109fd4a4e3SLai Jiangshan 5811753b43c9SLai Jiangshan void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, 5812cd42853eSLai Jiangshan u64 addr, unsigned long roots) 5813c50d8ae3SPaolo Bonzini { 5814c50d8ae3SPaolo Bonzini int i; 5815c50d8ae3SPaolo Bonzini 5816cd42853eSLai Jiangshan WARN_ON_ONCE(roots & ~KVM_MMU_ROOTS_ALL); 5817cd42853eSLai Jiangshan 58185efac074SPaolo Bonzini /* It's actually a GPA for vcpu->arch.guest_mmu. */ 58195efac074SPaolo Bonzini if (mmu != &vcpu->arch.guest_mmu) { 58205efac074SPaolo Bonzini /* INVLPG on a non-canonical address is a NOP according to the SDM. */ 5821753b43c9SLai Jiangshan if (is_noncanonical_address(addr, vcpu)) 5822c50d8ae3SPaolo Bonzini return; 5823c50d8ae3SPaolo Bonzini 5824753b43c9SLai Jiangshan static_call(kvm_x86_flush_tlb_gva)(vcpu, addr); 58255efac074SPaolo Bonzini } 58265efac074SPaolo Bonzini 58279fd4a4e3SLai Jiangshan if (!mmu->sync_spte) 58285efac074SPaolo Bonzini return; 58295efac074SPaolo Bonzini 5830cd42853eSLai Jiangshan if (roots & KVM_MMU_ROOT_CURRENT) 58319fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->root.hpa); 5832c50d8ae3SPaolo Bonzini 5833cd42853eSLai Jiangshan for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5834ed335278SLai Jiangshan if (roots & KVM_MMU_ROOT_PREVIOUS(i)) 58359fd4a4e3SLai Jiangshan __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->prev_roots[i].hpa); 58365efac074SPaolo Bonzini } 58375efac074SPaolo Bonzini } 58382c86c444SLai Jiangshan EXPORT_SYMBOL_GPL(kvm_mmu_invalidate_addr); 5839c50d8ae3SPaolo Bonzini 58405efac074SPaolo Bonzini void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 58415efac074SPaolo Bonzini { 5842cd42853eSLai Jiangshan /* 5843cd42853eSLai Jiangshan * INVLPG is required to invalidate any global mappings for the VA, 5844cd42853eSLai Jiangshan * irrespective of PCID. Blindly sync all roots as it would take 5845cd42853eSLai Jiangshan * roughly the same amount of work/time to determine whether any of the 5846cd42853eSLai Jiangshan * previous roots have a global mapping. 5847cd42853eSLai Jiangshan * 5848cd42853eSLai Jiangshan * Mappings not reachable via the current or previous cached roots will 5849cd42853eSLai Jiangshan * be synced when switching to that new cr3, so nothing needs to be 5850cd42853eSLai Jiangshan * done here for them. 5851cd42853eSLai Jiangshan */ 5852cd42853eSLai Jiangshan kvm_mmu_invalidate_addr(vcpu, vcpu->arch.walk_mmu, gva, KVM_MMU_ROOTS_ALL); 5853c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5854c50d8ae3SPaolo Bonzini } 5855c50d8ae3SPaolo Bonzini EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 5856c50d8ae3SPaolo Bonzini 58575efac074SPaolo Bonzini 5858c50d8ae3SPaolo Bonzini void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) 5859c50d8ae3SPaolo Bonzini { 5860c50d8ae3SPaolo Bonzini struct kvm_mmu *mmu = vcpu->arch.mmu; 58619ebc3f51SLai Jiangshan unsigned long roots = 0; 5862c50d8ae3SPaolo Bonzini uint i; 5863c50d8ae3SPaolo Bonzini 58649ebc3f51SLai Jiangshan if (pcid == kvm_get_active_pcid(vcpu)) 58659ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_CURRENT; 5866c50d8ae3SPaolo Bonzini 5867c50d8ae3SPaolo Bonzini for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { 5868c50d8ae3SPaolo Bonzini if (VALID_PAGE(mmu->prev_roots[i].hpa) && 58699ebc3f51SLai Jiangshan pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd)) 58709ebc3f51SLai Jiangshan roots |= KVM_MMU_ROOT_PREVIOUS(i); 5871c50d8ae3SPaolo Bonzini } 5872c50d8ae3SPaolo Bonzini 58739ebc3f51SLai Jiangshan if (roots) 58749ebc3f51SLai Jiangshan kvm_mmu_invalidate_addr(vcpu, mmu, gva, roots); 5875c50d8ae3SPaolo Bonzini ++vcpu->stat.invlpg; 5876c50d8ae3SPaolo Bonzini 5877c50d8ae3SPaolo Bonzini /* 5878c50d8ae3SPaolo Bonzini * Mappings not reachable via the current cr3 or the prev_roots will be 5879c50d8ae3SPaolo Bonzini * synced when switching to that cr3, so nothing needs to be done here 5880c50d8ae3SPaolo Bonzini * for them. 5881c50d8ae3SPaolo Bonzini */ 5882c50d8ae3SPaolo Bonzini } 5883c50d8ae3SPaolo Bonzini 5884746700d2SWei Huang void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, 5885746700d2SWei Huang int tdp_max_root_level, int tdp_huge_page_level) 5886c50d8ae3SPaolo Bonzini { 5887bde77235SSean Christopherson tdp_enabled = enable_tdp; 5888746700d2SWei Huang tdp_root_level = tdp_forced_root_level; 588983013059SSean Christopherson max_tdp_level = tdp_max_root_level; 5890703c335dSSean Christopherson 58911f98f2bdSDavid Matlack #ifdef CONFIG_X86_64 58921f98f2bdSDavid Matlack tdp_mmu_enabled = tdp_mmu_allowed && tdp_enabled; 58931f98f2bdSDavid Matlack #endif 5894703c335dSSean Christopherson /* 58951d92d2e8SSean Christopherson * max_huge_page_level reflects KVM's MMU capabilities irrespective 5896703c335dSSean Christopherson * of kernel support, e.g. KVM may be capable of using 1GB pages when 5897703c335dSSean Christopherson * the kernel is not. But, KVM never creates a page size greater than 5898703c335dSSean Christopherson * what is used by the kernel for any given HVA, i.e. the kernel's 5899703c335dSSean Christopherson * capabilities are ultimately consulted by kvm_mmu_hugepage_adjust(). 5900703c335dSSean Christopherson */ 5901703c335dSSean Christopherson if (tdp_enabled) 59021d92d2e8SSean Christopherson max_huge_page_level = tdp_huge_page_level; 5903703c335dSSean Christopherson else if (boot_cpu_has(X86_FEATURE_GBPAGES)) 59041d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_1G; 5905703c335dSSean Christopherson else 59061d92d2e8SSean Christopherson max_huge_page_level = PG_LEVEL_2M; 5907c50d8ae3SPaolo Bonzini } 5908bde77235SSean Christopherson EXPORT_SYMBOL_GPL(kvm_configure_mmu); 5909c50d8ae3SPaolo Bonzini 5910c50d8ae3SPaolo Bonzini /* The return value indicates if tlb flush on all vcpus is needed. */ 5911727ae377SSean Christopherson typedef bool (*slot_rmaps_handler) (struct kvm *kvm, 5912269e9552SHamza Mahfooz struct kvm_rmap_head *rmap_head, 5913269e9552SHamza Mahfooz const struct kvm_memory_slot *slot); 5914c50d8ae3SPaolo Bonzini 5915727ae377SSean Christopherson static __always_inline bool __walk_slot_rmaps(struct kvm *kvm, 5916727ae377SSean Christopherson const struct kvm_memory_slot *slot, 5917727ae377SSean Christopherson slot_rmaps_handler fn, 5918727ae377SSean Christopherson int start_level, int end_level, 5919727ae377SSean Christopherson gfn_t start_gfn, gfn_t end_gfn, 5920727ae377SSean Christopherson bool flush_on_yield, bool flush) 5921c50d8ae3SPaolo Bonzini { 5922c50d8ae3SPaolo Bonzini struct slot_rmap_walk_iterator iterator; 5923c50d8ae3SPaolo Bonzini 5924eddd9e83SSean Christopherson lockdep_assert_held_write(&kvm->mmu_lock); 5925eddd9e83SSean Christopherson 5926727ae377SSean Christopherson for_each_slot_rmap_range(slot, start_level, end_level, start_gfn, 5927c50d8ae3SPaolo Bonzini end_gfn, &iterator) { 5928c50d8ae3SPaolo Bonzini if (iterator.rmap) 5929727ae377SSean Christopherson flush |= fn(kvm, iterator.rmap, slot); 5930c50d8ae3SPaolo Bonzini 5931531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 5932302695a5SSean Christopherson if (flush && flush_on_yield) { 59338c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, start_gfn, 5934c50d8ae3SPaolo Bonzini iterator.gfn - start_gfn + 1); 5935c50d8ae3SPaolo Bonzini flush = false; 5936c50d8ae3SPaolo Bonzini } 5937531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 5938c50d8ae3SPaolo Bonzini } 5939c50d8ae3SPaolo Bonzini } 5940c50d8ae3SPaolo Bonzini 5941c50d8ae3SPaolo Bonzini return flush; 5942c50d8ae3SPaolo Bonzini } 5943c50d8ae3SPaolo Bonzini 5944727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps(struct kvm *kvm, 5945727ae377SSean Christopherson const struct kvm_memory_slot *slot, 5946727ae377SSean Christopherson slot_rmaps_handler fn, 5947727ae377SSean Christopherson int start_level, int end_level, 5948302695a5SSean Christopherson bool flush_on_yield) 5949c50d8ae3SPaolo Bonzini { 5950727ae377SSean Christopherson return __walk_slot_rmaps(kvm, slot, fn, start_level, end_level, 5951727ae377SSean Christopherson slot->base_gfn, slot->base_gfn + slot->npages - 1, 59521a61b7dbSSean Christopherson flush_on_yield, false); 5953c50d8ae3SPaolo Bonzini } 5954c50d8ae3SPaolo Bonzini 5955727ae377SSean Christopherson static __always_inline bool walk_slot_rmaps_4k(struct kvm *kvm, 5956727ae377SSean Christopherson const struct kvm_memory_slot *slot, 5957727ae377SSean Christopherson slot_rmaps_handler fn, 5958727ae377SSean Christopherson bool flush_on_yield) 5959c50d8ae3SPaolo Bonzini { 5960727ae377SSean Christopherson return walk_slot_rmaps(kvm, slot, fn, PG_LEVEL_4K, PG_LEVEL_4K, flush_on_yield); 5961c50d8ae3SPaolo Bonzini } 5962c50d8ae3SPaolo Bonzini 5963c50d8ae3SPaolo Bonzini static void free_mmu_pages(struct kvm_mmu *mmu) 5964c50d8ae3SPaolo Bonzini { 59654a98623dSSean Christopherson if (!tdp_enabled && mmu->pae_root) 59664a98623dSSean Christopherson set_memory_encrypted((unsigned long)mmu->pae_root, 1); 5967c50d8ae3SPaolo Bonzini free_page((unsigned long)mmu->pae_root); 596803ca4589SSean Christopherson free_page((unsigned long)mmu->pml4_root); 5969cb0f722aSWei Huang free_page((unsigned long)mmu->pml5_root); 5970c50d8ae3SPaolo Bonzini } 5971c50d8ae3SPaolo Bonzini 597204d28e37SSean Christopherson static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) 5973c50d8ae3SPaolo Bonzini { 5974c50d8ae3SPaolo Bonzini struct page *page; 5975c50d8ae3SPaolo Bonzini int i; 5976c50d8ae3SPaolo Bonzini 5977b9e5603cSPaolo Bonzini mmu->root.hpa = INVALID_PAGE; 5978b9e5603cSPaolo Bonzini mmu->root.pgd = 0; 597904d28e37SSean Christopherson for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) 598004d28e37SSean Christopherson mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; 598104d28e37SSean Christopherson 598227f4fca2SLai Jiangshan /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */ 598327f4fca2SLai Jiangshan if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu) 598427f4fca2SLai Jiangshan return 0; 598527f4fca2SLai Jiangshan 5986c50d8ae3SPaolo Bonzini /* 5987c50d8ae3SPaolo Bonzini * When using PAE paging, the four PDPTEs are treated as 'root' pages, 5988c50d8ae3SPaolo Bonzini * while the PDP table is a per-vCPU construct that's allocated at MMU 5989c50d8ae3SPaolo Bonzini * creation. When emulating 32-bit mode, cr3 is only 32 bits even on 5990c50d8ae3SPaolo Bonzini * x86_64. Therefore we need to allocate the PDP table in the first 599104d45551SSean Christopherson * 4GB of memory, which happens to fit the DMA32 zone. TDP paging 599204d45551SSean Christopherson * generally doesn't use PAE paging and can skip allocating the PDP 599304d45551SSean Christopherson * table. The main exception, handled here, is SVM's 32-bit NPT. The 599404d45551SSean Christopherson * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit 599584432316SLai Jiangshan * KVM; that horror is handled on-demand by mmu_alloc_special_roots(). 5996c50d8ae3SPaolo Bonzini */ 5997d468d94bSSean Christopherson if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) 5998c50d8ae3SPaolo Bonzini return 0; 5999c50d8ae3SPaolo Bonzini 6000c50d8ae3SPaolo Bonzini page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32); 6001c50d8ae3SPaolo Bonzini if (!page) 6002c50d8ae3SPaolo Bonzini return -ENOMEM; 6003c50d8ae3SPaolo Bonzini 6004c50d8ae3SPaolo Bonzini mmu->pae_root = page_address(page); 60054a98623dSSean Christopherson 60064a98623dSSean Christopherson /* 60074a98623dSSean Christopherson * CR3 is only 32 bits when PAE paging is used, thus it's impossible to 60084a98623dSSean Christopherson * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so 60094a98623dSSean Christopherson * that KVM's writes and the CPU's reads get along. Note, this is 60104a98623dSSean Christopherson * only necessary when using shadow paging, as 64-bit NPT can get at 60114a98623dSSean Christopherson * the C-bit even when shadowing 32-bit NPT, and SME isn't supported 60124a98623dSSean Christopherson * by 32-bit kernels (when KVM itself uses 32-bit NPT). 60134a98623dSSean Christopherson */ 60144a98623dSSean Christopherson if (!tdp_enabled) 60154a98623dSSean Christopherson set_memory_decrypted((unsigned long)mmu->pae_root, 1); 60164a98623dSSean Christopherson else 6017e54f1ff2SKai Huang WARN_ON_ONCE(shadow_me_value); 60184a98623dSSean Christopherson 6019c50d8ae3SPaolo Bonzini for (i = 0; i < 4; ++i) 6020c834e5e4SSean Christopherson mmu->pae_root[i] = INVALID_PAE_ROOT; 6021c50d8ae3SPaolo Bonzini 6022c50d8ae3SPaolo Bonzini return 0; 6023c50d8ae3SPaolo Bonzini } 6024c50d8ae3SPaolo Bonzini 6025c50d8ae3SPaolo Bonzini int kvm_mmu_create(struct kvm_vcpu *vcpu) 6026c50d8ae3SPaolo Bonzini { 6027c50d8ae3SPaolo Bonzini int ret; 6028c50d8ae3SPaolo Bonzini 60295962bfb7SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache; 60305f6078f9SSean Christopherson vcpu->arch.mmu_pte_list_desc_cache.gfp_zero = __GFP_ZERO; 60315f6078f9SSean Christopherson 60325962bfb7SSean Christopherson vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; 60335f6078f9SSean Christopherson vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; 60345962bfb7SSean Christopherson 603596880883SSean Christopherson vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; 603696880883SSean Christopherson 6037c50d8ae3SPaolo Bonzini vcpu->arch.mmu = &vcpu->arch.root_mmu; 6038c50d8ae3SPaolo Bonzini vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; 6039c50d8ae3SPaolo Bonzini 604004d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu); 6041c50d8ae3SPaolo Bonzini if (ret) 6042c50d8ae3SPaolo Bonzini return ret; 6043c50d8ae3SPaolo Bonzini 604404d28e37SSean Christopherson ret = __kvm_mmu_create(vcpu, &vcpu->arch.root_mmu); 6045c50d8ae3SPaolo Bonzini if (ret) 6046c50d8ae3SPaolo Bonzini goto fail_allocate_root; 6047c50d8ae3SPaolo Bonzini 6048c50d8ae3SPaolo Bonzini return ret; 6049c50d8ae3SPaolo Bonzini fail_allocate_root: 6050c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6051c50d8ae3SPaolo Bonzini return ret; 6052c50d8ae3SPaolo Bonzini } 6053c50d8ae3SPaolo Bonzini 6054c50d8ae3SPaolo Bonzini #define BATCH_ZAP_PAGES 10 6055c50d8ae3SPaolo Bonzini static void kvm_zap_obsolete_pages(struct kvm *kvm) 6056c50d8ae3SPaolo Bonzini { 6057c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6058c50d8ae3SPaolo Bonzini int nr_zapped, batch = 0; 6059b28cb0cdSSean Christopherson bool unstable; 6060c50d8ae3SPaolo Bonzini 6061c50d8ae3SPaolo Bonzini restart: 6062c50d8ae3SPaolo Bonzini list_for_each_entry_safe_reverse(sp, node, 6063c50d8ae3SPaolo Bonzini &kvm->arch.active_mmu_pages, link) { 6064c50d8ae3SPaolo Bonzini /* 6065c50d8ae3SPaolo Bonzini * No obsolete valid page exists before a newly created page 6066c50d8ae3SPaolo Bonzini * since active_mmu_pages is a FIFO list. 6067c50d8ae3SPaolo Bonzini */ 6068c50d8ae3SPaolo Bonzini if (!is_obsolete_sp(kvm, sp)) 6069c50d8ae3SPaolo Bonzini break; 6070c50d8ae3SPaolo Bonzini 6071c50d8ae3SPaolo Bonzini /* 6072f95eec9bSSean Christopherson * Invalid pages should never land back on the list of active 6073f95eec9bSSean Christopherson * pages. Skip the bogus page, otherwise we'll get stuck in an 6074f95eec9bSSean Christopherson * infinite loop if the page gets put back on the list (again). 6075c50d8ae3SPaolo Bonzini */ 6076f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6077c50d8ae3SPaolo Bonzini continue; 6078c50d8ae3SPaolo Bonzini 6079c50d8ae3SPaolo Bonzini /* 6080c50d8ae3SPaolo Bonzini * No need to flush the TLB since we're only zapping shadow 6081c50d8ae3SPaolo Bonzini * pages with an obsolete generation number and all vCPUS have 6082c50d8ae3SPaolo Bonzini * loaded a new root, i.e. the shadow pages being zapped cannot 6083c50d8ae3SPaolo Bonzini * be in active use by the guest. 6084c50d8ae3SPaolo Bonzini */ 6085c50d8ae3SPaolo Bonzini if (batch >= BATCH_ZAP_PAGES && 6086531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock)) { 6087c50d8ae3SPaolo Bonzini batch = 0; 6088c50d8ae3SPaolo Bonzini goto restart; 6089c50d8ae3SPaolo Bonzini } 6090c50d8ae3SPaolo Bonzini 6091b28cb0cdSSean Christopherson unstable = __kvm_mmu_prepare_zap_page(kvm, sp, 6092b28cb0cdSSean Christopherson &kvm->arch.zapped_obsolete_pages, &nr_zapped); 6093c50d8ae3SPaolo Bonzini batch += nr_zapped; 6094b28cb0cdSSean Christopherson 6095b28cb0cdSSean Christopherson if (unstable) 6096c50d8ae3SPaolo Bonzini goto restart; 6097c50d8ae3SPaolo Bonzini } 6098c50d8ae3SPaolo Bonzini 6099c50d8ae3SPaolo Bonzini /* 61007ae5840eSSean Christopherson * Kick all vCPUs (via remote TLB flush) before freeing the page tables 61017ae5840eSSean Christopherson * to ensure KVM is not in the middle of a lockless shadow page table 61027ae5840eSSean Christopherson * walk, which may reference the pages. The remote TLB flush itself is 61037ae5840eSSean Christopherson * not required and is simply a convenient way to kick vCPUs as needed. 61047ae5840eSSean Christopherson * KVM performs a local TLB flush when allocating a new root (see 61057ae5840eSSean Christopherson * kvm_mmu_load()), and the reload in the caller ensure no vCPUs are 61067ae5840eSSean Christopherson * running with an obsolete MMU. 6107c50d8ae3SPaolo Bonzini */ 6108c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages); 6109c50d8ae3SPaolo Bonzini } 6110c50d8ae3SPaolo Bonzini 6111c50d8ae3SPaolo Bonzini /* 6112c50d8ae3SPaolo Bonzini * Fast invalidate all shadow pages and use lock-break technique 6113c50d8ae3SPaolo Bonzini * to zap obsolete pages. 6114c50d8ae3SPaolo Bonzini * 6115c50d8ae3SPaolo Bonzini * It's required when memslot is being deleted or VM is being 6116c50d8ae3SPaolo Bonzini * destroyed, in these cases, we should ensure that KVM MMU does 6117c50d8ae3SPaolo Bonzini * not use any resource of the being-deleted slot or all slots 6118c50d8ae3SPaolo Bonzini * after calling the function. 6119c50d8ae3SPaolo Bonzini */ 6120c50d8ae3SPaolo Bonzini static void kvm_mmu_zap_all_fast(struct kvm *kvm) 6121c50d8ae3SPaolo Bonzini { 6122c50d8ae3SPaolo Bonzini lockdep_assert_held(&kvm->slots_lock); 6123c50d8ae3SPaolo Bonzini 6124531810caSBen Gardon write_lock(&kvm->mmu_lock); 6125c50d8ae3SPaolo Bonzini trace_kvm_mmu_zap_all_fast(kvm); 6126c50d8ae3SPaolo Bonzini 6127c50d8ae3SPaolo Bonzini /* 6128c50d8ae3SPaolo Bonzini * Toggle mmu_valid_gen between '0' and '1'. Because slots_lock is 6129c50d8ae3SPaolo Bonzini * held for the entire duration of zapping obsolete pages, it's 6130c50d8ae3SPaolo Bonzini * impossible for there to be multiple invalid generations associated 6131c50d8ae3SPaolo Bonzini * with *valid* shadow pages at any given time, i.e. there is exactly 6132c50d8ae3SPaolo Bonzini * one valid generation and (at most) one invalid generation. 6133c50d8ae3SPaolo Bonzini */ 6134c50d8ae3SPaolo Bonzini kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; 6135c50d8ae3SPaolo Bonzini 61362f6f66ccSSean Christopherson /* 61372f6f66ccSSean Christopherson * In order to ensure all vCPUs drop their soon-to-be invalid roots, 61382f6f66ccSSean Christopherson * invalidating TDP MMU roots must be done while holding mmu_lock for 61392f6f66ccSSean Christopherson * write and in the same critical section as making the reload request, 61402f6f66ccSSean Christopherson * e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield. 6141b7cccd39SBen Gardon */ 61421f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6143b7cccd39SBen Gardon kvm_tdp_mmu_invalidate_all_roots(kvm); 6144b7cccd39SBen Gardon 6145c50d8ae3SPaolo Bonzini /* 6146c50d8ae3SPaolo Bonzini * Notify all vcpus to reload its shadow page table and flush TLB. 6147c50d8ae3SPaolo Bonzini * Then all vcpus will switch to new shadow page table with the new 6148c50d8ae3SPaolo Bonzini * mmu_valid_gen. 6149c50d8ae3SPaolo Bonzini * 6150c50d8ae3SPaolo Bonzini * Note: we need to do this under the protection of mmu_lock, 6151c50d8ae3SPaolo Bonzini * otherwise, vcpu would purge shadow page but miss tlb flush. 6152c50d8ae3SPaolo Bonzini */ 6153527d5cd7SSean Christopherson kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_FREE_OBSOLETE_ROOTS); 6154c50d8ae3SPaolo Bonzini 6155c50d8ae3SPaolo Bonzini kvm_zap_obsolete_pages(kvm); 6156faaf05b0SBen Gardon 6157531810caSBen Gardon write_unlock(&kvm->mmu_lock); 61584c6654bdSBen Gardon 6159f28e9c7fSSean Christopherson /* 6160f28e9c7fSSean Christopherson * Zap the invalidated TDP MMU roots, all SPTEs must be dropped before 6161f28e9c7fSSean Christopherson * returning to the caller, e.g. if the zap is in response to a memslot 6162f28e9c7fSSean Christopherson * deletion, mmu_notifier callbacks will be unable to reach the SPTEs 6163f28e9c7fSSean Christopherson * associated with the deleted memslot once the update completes, and 6164f28e9c7fSSean Christopherson * Deferring the zap until the final reference to the root is put would 6165f28e9c7fSSean Christopherson * lead to use-after-free. 6166f28e9c7fSSean Christopherson */ 61671f98f2bdSDavid Matlack if (tdp_mmu_enabled) 61684c6654bdSBen Gardon kvm_tdp_mmu_zap_invalidated_roots(kvm); 6169c50d8ae3SPaolo Bonzini } 6170c50d8ae3SPaolo Bonzini 6171c50d8ae3SPaolo Bonzini static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 6172c50d8ae3SPaolo Bonzini { 6173c50d8ae3SPaolo Bonzini return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages)); 6174c50d8ae3SPaolo Bonzini } 6175c50d8ae3SPaolo Bonzini 6176c50d8ae3SPaolo Bonzini static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, 6177c50d8ae3SPaolo Bonzini struct kvm_memory_slot *slot, 6178c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node) 6179c50d8ae3SPaolo Bonzini { 6180c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6181c50d8ae3SPaolo Bonzini } 6182c50d8ae3SPaolo Bonzini 6183a1a39128SPaolo Bonzini int kvm_mmu_init_vm(struct kvm *kvm) 6184c50d8ae3SPaolo Bonzini { 6185c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6186a1a39128SPaolo Bonzini int r; 6187c50d8ae3SPaolo Bonzini 6188a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); 6189a1a39128SPaolo Bonzini INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); 619055c510e2SSean Christopherson INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages); 6191ce25681dSSean Christopherson spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); 6192ce25681dSSean Christopherson 619309732d2bSDavid Matlack if (tdp_mmu_enabled) { 6194a1a39128SPaolo Bonzini r = kvm_mmu_init_tdp_mmu(kvm); 6195a1a39128SPaolo Bonzini if (r < 0) 6196a1a39128SPaolo Bonzini return r; 619709732d2bSDavid Matlack } 6198fe5db27dSBen Gardon 6199c50d8ae3SPaolo Bonzini node->track_write = kvm_mmu_pte_write; 6200c50d8ae3SPaolo Bonzini node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; 6201c50d8ae3SPaolo Bonzini kvm_page_track_register_notifier(kvm, node); 6202ada51a9dSDavid Matlack 6203ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache; 6204ada51a9dSDavid Matlack kvm->arch.split_page_header_cache.gfp_zero = __GFP_ZERO; 6205ada51a9dSDavid Matlack 6206ada51a9dSDavid Matlack kvm->arch.split_shadow_page_cache.gfp_zero = __GFP_ZERO; 6207ada51a9dSDavid Matlack 6208ada51a9dSDavid Matlack kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache; 6209ada51a9dSDavid Matlack kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO; 6210ada51a9dSDavid Matlack 6211a1a39128SPaolo Bonzini return 0; 6212c50d8ae3SPaolo Bonzini } 6213c50d8ae3SPaolo Bonzini 6214ada51a9dSDavid Matlack static void mmu_free_vm_memory_caches(struct kvm *kvm) 6215ada51a9dSDavid Matlack { 6216ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_desc_cache); 6217ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_page_header_cache); 6218ada51a9dSDavid Matlack kvm_mmu_free_memory_cache(&kvm->arch.split_shadow_page_cache); 6219ada51a9dSDavid Matlack } 6220ada51a9dSDavid Matlack 6221c50d8ae3SPaolo Bonzini void kvm_mmu_uninit_vm(struct kvm *kvm) 6222c50d8ae3SPaolo Bonzini { 6223c50d8ae3SPaolo Bonzini struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; 6224c50d8ae3SPaolo Bonzini 6225c50d8ae3SPaolo Bonzini kvm_page_track_unregister_notifier(kvm, node); 6226fe5db27dSBen Gardon 622709732d2bSDavid Matlack if (tdp_mmu_enabled) 6228fe5db27dSBen Gardon kvm_mmu_uninit_tdp_mmu(kvm); 6229ada51a9dSDavid Matlack 6230ada51a9dSDavid Matlack mmu_free_vm_memory_caches(kvm); 6231c50d8ae3SPaolo Bonzini } 6232c50d8ae3SPaolo Bonzini 62332833eda0SSean Christopherson static bool kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 623421fa3246SSean Christopherson { 623521fa3246SSean Christopherson const struct kvm_memory_slot *memslot; 623621fa3246SSean Christopherson struct kvm_memslots *slots; 6237f4209439SMaciej S. Szmigiero struct kvm_memslot_iter iter; 623821fa3246SSean Christopherson bool flush = false; 623921fa3246SSean Christopherson gfn_t start, end; 6240f4209439SMaciej S. Szmigiero int i; 624121fa3246SSean Christopherson 624221fa3246SSean Christopherson if (!kvm_memslots_have_rmaps(kvm)) 624321fa3246SSean Christopherson return flush; 624421fa3246SSean Christopherson 624521fa3246SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { 624621fa3246SSean Christopherson slots = __kvm_memslots(kvm, i); 6247f4209439SMaciej S. Szmigiero 6248f4209439SMaciej S. Szmigiero kvm_for_each_memslot_in_gfn_range(&iter, slots, gfn_start, gfn_end) { 6249f4209439SMaciej S. Szmigiero memslot = iter.slot; 625021fa3246SSean Christopherson start = max(gfn_start, memslot->base_gfn); 625121fa3246SSean Christopherson end = min(gfn_end, memslot->base_gfn + memslot->npages); 6252f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(start >= end)) 625321fa3246SSean Christopherson continue; 625421fa3246SSean Christopherson 6255727ae377SSean Christopherson flush = __walk_slot_rmaps(kvm, memslot, __kvm_zap_rmap, 625621fa3246SSean Christopherson PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, 625721fa3246SSean Christopherson start, end - 1, true, flush); 625821fa3246SSean Christopherson } 625921fa3246SSean Christopherson } 626021fa3246SSean Christopherson 626121fa3246SSean Christopherson return flush; 626221fa3246SSean Christopherson } 626321fa3246SSean Christopherson 626488f58535SMaxim Levitsky /* 626588f58535SMaxim Levitsky * Invalidate (zap) SPTEs that cover GFNs from gfn_start and up to gfn_end 626688f58535SMaxim Levitsky * (not including it) 626788f58535SMaxim Levitsky */ 6268c50d8ae3SPaolo Bonzini void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) 6269c50d8ae3SPaolo Bonzini { 627021fa3246SSean Christopherson bool flush; 6271c50d8ae3SPaolo Bonzini int i; 6272c50d8ae3SPaolo Bonzini 6273f4209439SMaciej S. Szmigiero if (WARN_ON_ONCE(gfn_end <= gfn_start)) 6274f4209439SMaciej S. Szmigiero return; 6275f4209439SMaciej S. Szmigiero 6276531810caSBen Gardon write_lock(&kvm->mmu_lock); 62775a324c24SSean Christopherson 62786d3085e4SSean Christopherson kvm_mmu_invalidate_begin(kvm, 0, -1ul); 6279edb298c6SMaxim Levitsky 62802833eda0SSean Christopherson flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end); 62816103bc07SBen Gardon 62821f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 62836103bc07SBen Gardon for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 6284f47e5bbbSSean Christopherson flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start, 6285f47e5bbbSSean Christopherson gfn_end, true, flush); 62866103bc07SBen Gardon } 62875a324c24SSean Christopherson 62885a324c24SSean Christopherson if (flush) 62898c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, gfn_start, gfn_end - gfn_start); 62905a324c24SSean Christopherson 62916d3085e4SSean Christopherson kvm_mmu_invalidate_end(kvm, 0, -1ul); 6292edb298c6SMaxim Levitsky 62935a324c24SSean Christopherson write_unlock(&kvm->mmu_lock); 6294c50d8ae3SPaolo Bonzini } 6295c50d8ae3SPaolo Bonzini 6296c50d8ae3SPaolo Bonzini static bool slot_rmap_write_protect(struct kvm *kvm, 62970a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6298269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6299c50d8ae3SPaolo Bonzini { 63001346bbb6SDavid Matlack return rmap_write_protect(rmap_head, false); 6301c50d8ae3SPaolo Bonzini } 6302c50d8ae3SPaolo Bonzini 6303c50d8ae3SPaolo Bonzini void kvm_mmu_slot_remove_write_access(struct kvm *kvm, 6304269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot, 63053c9bd400SJay Zhou int start_level) 6306c50d8ae3SPaolo Bonzini { 6307e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6308531810caSBen Gardon write_lock(&kvm->mmu_lock); 6309727ae377SSean Christopherson walk_slot_rmaps(kvm, memslot, slot_rmap_write_protect, 6310b64d740eSJunaid Shahid start_level, KVM_MAX_HUGEPAGE_LEVEL, false); 6311531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6312e2209710SBen Gardon } 6313c50d8ae3SPaolo Bonzini 63141f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 631524ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6316b64d740eSJunaid Shahid kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); 631724ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 631824ae4cfaSBen Gardon } 6319c50d8ae3SPaolo Bonzini } 6320c50d8ae3SPaolo Bonzini 6321ada51a9dSDavid Matlack static inline bool need_topup(struct kvm_mmu_memory_cache *cache, int min) 6322ada51a9dSDavid Matlack { 6323ada51a9dSDavid Matlack return kvm_mmu_memory_cache_nr_free_objects(cache) < min; 6324ada51a9dSDavid Matlack } 6325ada51a9dSDavid Matlack 6326ada51a9dSDavid Matlack static bool need_topup_split_caches_or_resched(struct kvm *kvm) 6327ada51a9dSDavid Matlack { 6328ada51a9dSDavid Matlack if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) 6329ada51a9dSDavid Matlack return true; 6330ada51a9dSDavid Matlack 6331ada51a9dSDavid Matlack /* 6332ada51a9dSDavid Matlack * In the worst case, SPLIT_DESC_CACHE_MIN_NR_OBJECTS descriptors are needed 6333ada51a9dSDavid Matlack * to split a single huge page. Calculating how many are actually needed 6334ada51a9dSDavid Matlack * is possible but not worth the complexity. 6335ada51a9dSDavid Matlack */ 6336ada51a9dSDavid Matlack return need_topup(&kvm->arch.split_desc_cache, SPLIT_DESC_CACHE_MIN_NR_OBJECTS) || 6337ada51a9dSDavid Matlack need_topup(&kvm->arch.split_page_header_cache, 1) || 6338ada51a9dSDavid Matlack need_topup(&kvm->arch.split_shadow_page_cache, 1); 6339ada51a9dSDavid Matlack } 6340ada51a9dSDavid Matlack 6341ada51a9dSDavid Matlack static int topup_split_caches(struct kvm *kvm) 6342ada51a9dSDavid Matlack { 6343b9b71f43SSean Christopherson /* 6344b9b71f43SSean Christopherson * Allocating rmap list entries when splitting huge pages for nested 6345dfd4eb44SSean Christopherson * MMUs is uncommon as KVM needs to use a list if and only if there is 6346b9b71f43SSean Christopherson * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be 6347dfd4eb44SSean Christopherson * aliased by multiple L2 gfns and/or from multiple nested roots with 6348dfd4eb44SSean Christopherson * different roles. Aliasing gfns when using TDP is atypical for VMMs; 6349dfd4eb44SSean Christopherson * a few gfns are often aliased during boot, e.g. when remapping BIOS, 6350dfd4eb44SSean Christopherson * but aliasing rarely occurs post-boot or for many gfns. If there is 6351dfd4eb44SSean Christopherson * only one rmap entry, rmap->val points directly at that one entry and 6352dfd4eb44SSean Christopherson * doesn't need to allocate a list. Buffer the cache by the default 6353dfd4eb44SSean Christopherson * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM 6354b9b71f43SSean Christopherson * encounters an aliased gfn or two. 6355b9b71f43SSean Christopherson */ 6356b9b71f43SSean Christopherson const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + 6357b9b71f43SSean Christopherson KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE; 6358ada51a9dSDavid Matlack int r; 6359ada51a9dSDavid Matlack 6360ada51a9dSDavid Matlack lockdep_assert_held(&kvm->slots_lock); 6361ada51a9dSDavid Matlack 6362b9b71f43SSean Christopherson r = __kvm_mmu_topup_memory_cache(&kvm->arch.split_desc_cache, capacity, 6363ada51a9dSDavid Matlack SPLIT_DESC_CACHE_MIN_NR_OBJECTS); 6364ada51a9dSDavid Matlack if (r) 6365ada51a9dSDavid Matlack return r; 6366ada51a9dSDavid Matlack 6367ada51a9dSDavid Matlack r = kvm_mmu_topup_memory_cache(&kvm->arch.split_page_header_cache, 1); 6368ada51a9dSDavid Matlack if (r) 6369ada51a9dSDavid Matlack return r; 6370ada51a9dSDavid Matlack 6371ada51a9dSDavid Matlack return kvm_mmu_topup_memory_cache(&kvm->arch.split_shadow_page_cache, 1); 6372ada51a9dSDavid Matlack } 6373ada51a9dSDavid Matlack 6374ada51a9dSDavid Matlack static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *huge_sptep) 6375ada51a9dSDavid Matlack { 6376ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6377ada51a9dSDavid Matlack struct shadow_page_caches caches = {}; 6378ada51a9dSDavid Matlack union kvm_mmu_page_role role; 6379ada51a9dSDavid Matlack unsigned int access; 6380ada51a9dSDavid Matlack gfn_t gfn; 6381ada51a9dSDavid Matlack 638279e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 638379e48cecSSean Christopherson access = kvm_mmu_page_get_access(huge_sp, spte_index(huge_sptep)); 6384ada51a9dSDavid Matlack 6385ada51a9dSDavid Matlack /* 6386ada51a9dSDavid Matlack * Note, huge page splitting always uses direct shadow pages, regardless 6387ada51a9dSDavid Matlack * of whether the huge page itself is mapped by a direct or indirect 6388ada51a9dSDavid Matlack * shadow page, since the huge page region itself is being directly 6389ada51a9dSDavid Matlack * mapped with smaller pages. 6390ada51a9dSDavid Matlack */ 6391ada51a9dSDavid Matlack role = kvm_mmu_child_role(huge_sptep, /*direct=*/true, access); 6392ada51a9dSDavid Matlack 6393ada51a9dSDavid Matlack /* Direct SPs do not require a shadowed_info_cache. */ 6394ada51a9dSDavid Matlack caches.page_header_cache = &kvm->arch.split_page_header_cache; 6395ada51a9dSDavid Matlack caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache; 6396ada51a9dSDavid Matlack 6397ada51a9dSDavid Matlack /* Safe to pass NULL for vCPU since requesting a direct SP. */ 6398ada51a9dSDavid Matlack return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role); 6399ada51a9dSDavid Matlack } 6400ada51a9dSDavid Matlack 6401ada51a9dSDavid Matlack static void shadow_mmu_split_huge_page(struct kvm *kvm, 6402ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6403ada51a9dSDavid Matlack u64 *huge_sptep) 6404ada51a9dSDavid Matlack 6405ada51a9dSDavid Matlack { 6406ada51a9dSDavid Matlack struct kvm_mmu_memory_cache *cache = &kvm->arch.split_desc_cache; 6407ada51a9dSDavid Matlack u64 huge_spte = READ_ONCE(*huge_sptep); 6408ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 640903787394SPaolo Bonzini bool flush = false; 6410ada51a9dSDavid Matlack u64 *sptep, spte; 6411ada51a9dSDavid Matlack gfn_t gfn; 6412ada51a9dSDavid Matlack int index; 6413ada51a9dSDavid Matlack 6414ada51a9dSDavid Matlack sp = shadow_mmu_get_sp_for_split(kvm, huge_sptep); 6415ada51a9dSDavid Matlack 6416ada51a9dSDavid Matlack for (index = 0; index < SPTE_ENT_PER_PAGE; index++) { 6417ada51a9dSDavid Matlack sptep = &sp->spt[index]; 6418ada51a9dSDavid Matlack gfn = kvm_mmu_page_get_gfn(sp, index); 6419ada51a9dSDavid Matlack 6420ada51a9dSDavid Matlack /* 6421ada51a9dSDavid Matlack * The SP may already have populated SPTEs, e.g. if this huge 6422ada51a9dSDavid Matlack * page is aliased by multiple sptes with the same access 6423ada51a9dSDavid Matlack * permissions. These entries are guaranteed to map the same 6424ada51a9dSDavid Matlack * gfn-to-pfn translation since the SP is direct, so no need to 6425ada51a9dSDavid Matlack * modify them. 6426ada51a9dSDavid Matlack * 642703787394SPaolo Bonzini * However, if a given SPTE points to a lower level page table, 642803787394SPaolo Bonzini * that lower level page table may only be partially populated. 642903787394SPaolo Bonzini * Installing such SPTEs would effectively unmap a potion of the 643003787394SPaolo Bonzini * huge page. Unmapping guest memory always requires a TLB flush 643103787394SPaolo Bonzini * since a subsequent operation on the unmapped regions would 643203787394SPaolo Bonzini * fail to detect the need to flush. 6433ada51a9dSDavid Matlack */ 643403787394SPaolo Bonzini if (is_shadow_present_pte(*sptep)) { 643503787394SPaolo Bonzini flush |= !is_last_spte(*sptep, sp->role.level); 6436ada51a9dSDavid Matlack continue; 643703787394SPaolo Bonzini } 6438ada51a9dSDavid Matlack 6439ada51a9dSDavid Matlack spte = make_huge_page_split_spte(kvm, huge_spte, sp->role, index); 6440ada51a9dSDavid Matlack mmu_spte_set(sptep, spte); 6441ada51a9dSDavid Matlack __rmap_add(kvm, cache, slot, sptep, gfn, sp->role.access); 6442ada51a9dSDavid Matlack } 6443ada51a9dSDavid Matlack 644403787394SPaolo Bonzini __link_shadow_page(kvm, cache, huge_sptep, sp, flush); 6445ada51a9dSDavid Matlack } 6446ada51a9dSDavid Matlack 6447ada51a9dSDavid Matlack static int shadow_mmu_try_split_huge_page(struct kvm *kvm, 6448ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6449ada51a9dSDavid Matlack u64 *huge_sptep) 6450ada51a9dSDavid Matlack { 6451ada51a9dSDavid Matlack struct kvm_mmu_page *huge_sp = sptep_to_sp(huge_sptep); 6452ada51a9dSDavid Matlack int level, r = 0; 6453ada51a9dSDavid Matlack gfn_t gfn; 6454ada51a9dSDavid Matlack u64 spte; 6455ada51a9dSDavid Matlack 6456ada51a9dSDavid Matlack /* Grab information for the tracepoint before dropping the MMU lock. */ 645779e48cecSSean Christopherson gfn = kvm_mmu_page_get_gfn(huge_sp, spte_index(huge_sptep)); 6458ada51a9dSDavid Matlack level = huge_sp->role.level; 6459ada51a9dSDavid Matlack spte = *huge_sptep; 6460ada51a9dSDavid Matlack 6461ada51a9dSDavid Matlack if (kvm_mmu_available_pages(kvm) <= KVM_MIN_FREE_MMU_PAGES) { 6462ada51a9dSDavid Matlack r = -ENOSPC; 6463ada51a9dSDavid Matlack goto out; 6464ada51a9dSDavid Matlack } 6465ada51a9dSDavid Matlack 6466ada51a9dSDavid Matlack if (need_topup_split_caches_or_resched(kvm)) { 6467ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6468ada51a9dSDavid Matlack cond_resched(); 6469ada51a9dSDavid Matlack /* 6470ada51a9dSDavid Matlack * If the topup succeeds, return -EAGAIN to indicate that the 6471ada51a9dSDavid Matlack * rmap iterator should be restarted because the MMU lock was 6472ada51a9dSDavid Matlack * dropped. 6473ada51a9dSDavid Matlack */ 6474ada51a9dSDavid Matlack r = topup_split_caches(kvm) ?: -EAGAIN; 6475ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6476ada51a9dSDavid Matlack goto out; 6477ada51a9dSDavid Matlack } 6478ada51a9dSDavid Matlack 6479ada51a9dSDavid Matlack shadow_mmu_split_huge_page(kvm, slot, huge_sptep); 6480ada51a9dSDavid Matlack 6481ada51a9dSDavid Matlack out: 6482ada51a9dSDavid Matlack trace_kvm_mmu_split_huge_page(gfn, spte, level, r); 6483ada51a9dSDavid Matlack return r; 6484ada51a9dSDavid Matlack } 6485ada51a9dSDavid Matlack 6486ada51a9dSDavid Matlack static bool shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6487ada51a9dSDavid Matlack struct kvm_rmap_head *rmap_head, 6488ada51a9dSDavid Matlack const struct kvm_memory_slot *slot) 6489ada51a9dSDavid Matlack { 6490ada51a9dSDavid Matlack struct rmap_iterator iter; 6491ada51a9dSDavid Matlack struct kvm_mmu_page *sp; 6492ada51a9dSDavid Matlack u64 *huge_sptep; 6493ada51a9dSDavid Matlack int r; 6494ada51a9dSDavid Matlack 6495ada51a9dSDavid Matlack restart: 6496ada51a9dSDavid Matlack for_each_rmap_spte(rmap_head, &iter, huge_sptep) { 6497ada51a9dSDavid Matlack sp = sptep_to_sp(huge_sptep); 6498ada51a9dSDavid Matlack 6499ada51a9dSDavid Matlack /* TDP MMU is enabled, so rmap only contains nested MMU SPs. */ 6500ada51a9dSDavid Matlack if (WARN_ON_ONCE(!sp->role.guest_mode)) 6501ada51a9dSDavid Matlack continue; 6502ada51a9dSDavid Matlack 6503ada51a9dSDavid Matlack /* The rmaps should never contain non-leaf SPTEs. */ 6504ada51a9dSDavid Matlack if (WARN_ON_ONCE(!is_large_pte(*huge_sptep))) 6505ada51a9dSDavid Matlack continue; 6506ada51a9dSDavid Matlack 6507ada51a9dSDavid Matlack /* SPs with level >PG_LEVEL_4K should never by unsync. */ 6508ada51a9dSDavid Matlack if (WARN_ON_ONCE(sp->unsync)) 6509ada51a9dSDavid Matlack continue; 6510ada51a9dSDavid Matlack 6511ada51a9dSDavid Matlack /* Don't bother splitting huge pages on invalid SPs. */ 6512ada51a9dSDavid Matlack if (sp->role.invalid) 6513ada51a9dSDavid Matlack continue; 6514ada51a9dSDavid Matlack 6515ada51a9dSDavid Matlack r = shadow_mmu_try_split_huge_page(kvm, slot, huge_sptep); 6516ada51a9dSDavid Matlack 6517ada51a9dSDavid Matlack /* 6518ada51a9dSDavid Matlack * The split succeeded or needs to be retried because the MMU 6519ada51a9dSDavid Matlack * lock was dropped. Either way, restart the iterator to get it 6520ada51a9dSDavid Matlack * back into a consistent state. 6521ada51a9dSDavid Matlack */ 6522ada51a9dSDavid Matlack if (!r || r == -EAGAIN) 6523ada51a9dSDavid Matlack goto restart; 6524ada51a9dSDavid Matlack 6525ada51a9dSDavid Matlack /* The split failed and shouldn't be retried (e.g. -ENOMEM). */ 6526ada51a9dSDavid Matlack break; 6527ada51a9dSDavid Matlack } 6528ada51a9dSDavid Matlack 6529ada51a9dSDavid Matlack return false; 6530ada51a9dSDavid Matlack } 6531ada51a9dSDavid Matlack 6532ada51a9dSDavid Matlack static void kvm_shadow_mmu_try_split_huge_pages(struct kvm *kvm, 6533ada51a9dSDavid Matlack const struct kvm_memory_slot *slot, 6534ada51a9dSDavid Matlack gfn_t start, gfn_t end, 6535ada51a9dSDavid Matlack int target_level) 6536ada51a9dSDavid Matlack { 6537ada51a9dSDavid Matlack int level; 6538ada51a9dSDavid Matlack 6539ada51a9dSDavid Matlack /* 6540ada51a9dSDavid Matlack * Split huge pages starting with KVM_MAX_HUGEPAGE_LEVEL and working 6541ada51a9dSDavid Matlack * down to the target level. This ensures pages are recursively split 6542ada51a9dSDavid Matlack * all the way to the target level. There's no need to split pages 6543ada51a9dSDavid Matlack * already at the target level. 6544ada51a9dSDavid Matlack */ 6545727ae377SSean Christopherson for (level = KVM_MAX_HUGEPAGE_LEVEL; level > target_level; level--) 6546727ae377SSean Christopherson __walk_slot_rmaps(kvm, slot, shadow_mmu_try_split_huge_pages, 6547ada51a9dSDavid Matlack level, level, start, end - 1, true, false); 6548ada51a9dSDavid Matlack } 6549ada51a9dSDavid Matlack 6550cb00a70bSDavid Matlack /* Must be called with the mmu_lock held in write-mode. */ 6551cb00a70bSDavid Matlack void kvm_mmu_try_split_huge_pages(struct kvm *kvm, 6552cb00a70bSDavid Matlack const struct kvm_memory_slot *memslot, 6553cb00a70bSDavid Matlack u64 start, u64 end, 6554cb00a70bSDavid Matlack int target_level) 6555cb00a70bSDavid Matlack { 65561f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6557ada51a9dSDavid Matlack return; 6558ada51a9dSDavid Matlack 6559ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) 6560ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6561ada51a9dSDavid Matlack 6562ada51a9dSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, false); 6563cb00a70bSDavid Matlack 6564cb00a70bSDavid Matlack /* 6565cb00a70bSDavid Matlack * A TLB flush is unnecessary at this point for the same resons as in 6566cb00a70bSDavid Matlack * kvm_mmu_slot_try_split_huge_pages(). 6567cb00a70bSDavid Matlack */ 6568cb00a70bSDavid Matlack } 6569cb00a70bSDavid Matlack 6570a3fe5dbdSDavid Matlack void kvm_mmu_slot_try_split_huge_pages(struct kvm *kvm, 6571a3fe5dbdSDavid Matlack const struct kvm_memory_slot *memslot, 6572a3fe5dbdSDavid Matlack int target_level) 6573a3fe5dbdSDavid Matlack { 6574a3fe5dbdSDavid Matlack u64 start = memslot->base_gfn; 6575a3fe5dbdSDavid Matlack u64 end = start + memslot->npages; 6576a3fe5dbdSDavid Matlack 65771f98f2bdSDavid Matlack if (!tdp_mmu_enabled) 6578ada51a9dSDavid Matlack return; 6579ada51a9dSDavid Matlack 6580ada51a9dSDavid Matlack if (kvm_memslots_have_rmaps(kvm)) { 6581ada51a9dSDavid Matlack write_lock(&kvm->mmu_lock); 6582ada51a9dSDavid Matlack kvm_shadow_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level); 6583ada51a9dSDavid Matlack write_unlock(&kvm->mmu_lock); 6584ada51a9dSDavid Matlack } 6585ada51a9dSDavid Matlack 6586a3fe5dbdSDavid Matlack read_lock(&kvm->mmu_lock); 6587cb00a70bSDavid Matlack kvm_tdp_mmu_try_split_huge_pages(kvm, memslot, start, end, target_level, true); 6588a3fe5dbdSDavid Matlack read_unlock(&kvm->mmu_lock); 6589a3fe5dbdSDavid Matlack 6590a3fe5dbdSDavid Matlack /* 6591a3fe5dbdSDavid Matlack * No TLB flush is necessary here. KVM will flush TLBs after 6592a3fe5dbdSDavid Matlack * write-protecting and/or clearing dirty on the newly split SPTEs to 6593a3fe5dbdSDavid Matlack * ensure that guest writes are reflected in the dirty log before the 6594a3fe5dbdSDavid Matlack * ioctl to enable dirty logging on this memslot completes. Since the 6595a3fe5dbdSDavid Matlack * split SPTEs retain the write and dirty bits of the huge SPTE, it is 6596a3fe5dbdSDavid Matlack * safe for KVM to decide if a TLB flush is necessary based on the split 6597a3fe5dbdSDavid Matlack * SPTEs. 6598a3fe5dbdSDavid Matlack */ 6599a3fe5dbdSDavid Matlack } 6600a3fe5dbdSDavid Matlack 6601c50d8ae3SPaolo Bonzini static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 66020a234f5dSSean Christopherson struct kvm_rmap_head *rmap_head, 6603269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6604c50d8ae3SPaolo Bonzini { 6605c50d8ae3SPaolo Bonzini u64 *sptep; 6606c50d8ae3SPaolo Bonzini struct rmap_iterator iter; 6607c50d8ae3SPaolo Bonzini int need_tlb_flush = 0; 6608c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 6609c50d8ae3SPaolo Bonzini 6610c50d8ae3SPaolo Bonzini restart: 6611c50d8ae3SPaolo Bonzini for_each_rmap_spte(rmap_head, &iter, sptep) { 661257354682SSean Christopherson sp = sptep_to_sp(sptep); 6613c50d8ae3SPaolo Bonzini 6614c50d8ae3SPaolo Bonzini /* 6615c50d8ae3SPaolo Bonzini * We cannot do huge page mapping for indirect shadow pages, 6616c50d8ae3SPaolo Bonzini * which are found on the last rmap (level = 1) when not using 6617c50d8ae3SPaolo Bonzini * tdp; such shadow pages are synced with the page table in 6618c50d8ae3SPaolo Bonzini * the guest, and the guest page table is using 4K page size 6619c50d8ae3SPaolo Bonzini * mapping if the indirect sp has level = 1. 6620c50d8ae3SPaolo Bonzini */ 66215d49f08cSSean Christopherson if (sp->role.direct && 66229eba50f8SSean Christopherson sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, 6623a8ac499bSSean Christopherson PG_LEVEL_NUM)) { 66249202aee8SSean Christopherson kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); 6625c50d8ae3SPaolo Bonzini 6626c50d8ae3SPaolo Bonzini if (kvm_available_flush_tlb_with_range()) 66271b2dc736SHou Wenlong kvm_flush_remote_tlbs_sptep(kvm, sptep); 6628c50d8ae3SPaolo Bonzini else 6629c50d8ae3SPaolo Bonzini need_tlb_flush = 1; 6630c50d8ae3SPaolo Bonzini 6631c50d8ae3SPaolo Bonzini goto restart; 6632c50d8ae3SPaolo Bonzini } 6633c50d8ae3SPaolo Bonzini } 6634c50d8ae3SPaolo Bonzini 6635c50d8ae3SPaolo Bonzini return need_tlb_flush; 6636c50d8ae3SPaolo Bonzini } 6637c50d8ae3SPaolo Bonzini 663820d49186SDavid Matlack static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, 663920d49186SDavid Matlack const struct kvm_memory_slot *slot) 664020d49186SDavid Matlack { 664120d49186SDavid Matlack /* 664220d49186SDavid Matlack * Note, use KVM_MAX_HUGEPAGE_LEVEL - 1 since there's no need to zap 664320d49186SDavid Matlack * pages that are already mapped at the maximum hugepage level. 664420d49186SDavid Matlack */ 6645727ae377SSean Christopherson if (walk_slot_rmaps(kvm, slot, kvm_mmu_zap_collapsible_spte, 664620d49186SDavid Matlack PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL - 1, true)) 664720d49186SDavid Matlack kvm_arch_flush_remote_tlbs_memslot(kvm, slot); 664820d49186SDavid Matlack } 664920d49186SDavid Matlack 6650c50d8ae3SPaolo Bonzini void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, 6651269e9552SHamza Mahfooz const struct kvm_memory_slot *slot) 6652c50d8ae3SPaolo Bonzini { 6653e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6654531810caSBen Gardon write_lock(&kvm->mmu_lock); 665520d49186SDavid Matlack kvm_rmap_zap_collapsible_sptes(kvm, slot); 6656531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6657e2209710SBen Gardon } 66582db6f772SBen Gardon 66591f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 66602db6f772SBen Gardon read_lock(&kvm->mmu_lock); 66614b85c921SSean Christopherson kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); 66622db6f772SBen Gardon read_unlock(&kvm->mmu_lock); 66632db6f772SBen Gardon } 6664c50d8ae3SPaolo Bonzini } 6665c50d8ae3SPaolo Bonzini 6666b3594ffbSSean Christopherson void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, 66676c9dd6d2SPaolo Bonzini const struct kvm_memory_slot *memslot) 6668b3594ffbSSean Christopherson { 6669b3594ffbSSean Christopherson /* 66707f42aa76SSean Christopherson * All current use cases for flushing the TLBs for a specific memslot 6671302695a5SSean Christopherson * related to dirty logging, and many do the TLB flush out of mmu_lock. 66727f42aa76SSean Christopherson * The interaction between the various operations on memslot must be 66737f42aa76SSean Christopherson * serialized by slots_locks to ensure the TLB flush from one operation 66747f42aa76SSean Christopherson * is observed by any other operation on the same memslot. 6675b3594ffbSSean Christopherson */ 6676b3594ffbSSean Christopherson lockdep_assert_held(&kvm->slots_lock); 66778c63e8c2SDavid Matlack kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages); 6678b3594ffbSSean Christopherson } 6679b3594ffbSSean Christopherson 6680c50d8ae3SPaolo Bonzini void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, 6681269e9552SHamza Mahfooz const struct kvm_memory_slot *memslot) 6682c50d8ae3SPaolo Bonzini { 6683e2209710SBen Gardon if (kvm_memslots_have_rmaps(kvm)) { 6684531810caSBen Gardon write_lock(&kvm->mmu_lock); 6685610265eaSDavid Matlack /* 6686610265eaSDavid Matlack * Clear dirty bits only on 4k SPTEs since the legacy MMU only 6687610265eaSDavid Matlack * support dirty logging at a 4k granularity. 6688610265eaSDavid Matlack */ 6689727ae377SSean Christopherson walk_slot_rmaps_4k(kvm, memslot, __rmap_clear_dirty, false); 6690531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6691e2209710SBen Gardon } 6692c50d8ae3SPaolo Bonzini 66931f98f2bdSDavid Matlack if (tdp_mmu_enabled) { 669424ae4cfaSBen Gardon read_lock(&kvm->mmu_lock); 6695b64d740eSJunaid Shahid kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); 669624ae4cfaSBen Gardon read_unlock(&kvm->mmu_lock); 669724ae4cfaSBen Gardon } 669824ae4cfaSBen Gardon 6699c50d8ae3SPaolo Bonzini /* 6700b64d740eSJunaid Shahid * The caller will flush the TLBs after this function returns. 6701b64d740eSJunaid Shahid * 6702c50d8ae3SPaolo Bonzini * It's also safe to flush TLBs out of mmu lock here as currently this 6703c50d8ae3SPaolo Bonzini * function is only used for dirty logging, in which case flushing TLB 6704c50d8ae3SPaolo Bonzini * out of mmu lock also guarantees no dirty pages will be lost in 6705c50d8ae3SPaolo Bonzini * dirty_bitmap. 6706c50d8ae3SPaolo Bonzini */ 6707c50d8ae3SPaolo Bonzini } 6708c50d8ae3SPaolo Bonzini 6709c50d8ae3SPaolo Bonzini void kvm_mmu_zap_all(struct kvm *kvm) 6710c50d8ae3SPaolo Bonzini { 6711c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp, *node; 6712c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6713c50d8ae3SPaolo Bonzini int ign; 6714c50d8ae3SPaolo Bonzini 6715531810caSBen Gardon write_lock(&kvm->mmu_lock); 6716c50d8ae3SPaolo Bonzini restart: 6717c50d8ae3SPaolo Bonzini list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { 6718f95eec9bSSean Christopherson if (WARN_ON(sp->role.invalid)) 6719c50d8ae3SPaolo Bonzini continue; 6720c50d8ae3SPaolo Bonzini if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) 6721c50d8ae3SPaolo Bonzini goto restart; 6722531810caSBen Gardon if (cond_resched_rwlock_write(&kvm->mmu_lock)) 6723c50d8ae3SPaolo Bonzini goto restart; 6724c50d8ae3SPaolo Bonzini } 6725c50d8ae3SPaolo Bonzini 6726c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, &invalid_list); 6727faaf05b0SBen Gardon 67281f98f2bdSDavid Matlack if (tdp_mmu_enabled) 6729faaf05b0SBen Gardon kvm_tdp_mmu_zap_all(kvm); 6730faaf05b0SBen Gardon 6731531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6732c50d8ae3SPaolo Bonzini } 6733c50d8ae3SPaolo Bonzini 6734c50d8ae3SPaolo Bonzini void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) 6735c50d8ae3SPaolo Bonzini { 6736c50d8ae3SPaolo Bonzini WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); 6737c50d8ae3SPaolo Bonzini 6738c50d8ae3SPaolo Bonzini gen &= MMIO_SPTE_GEN_MASK; 6739c50d8ae3SPaolo Bonzini 6740c50d8ae3SPaolo Bonzini /* 6741c50d8ae3SPaolo Bonzini * Generation numbers are incremented in multiples of the number of 6742c50d8ae3SPaolo Bonzini * address spaces in order to provide unique generations across all 6743c50d8ae3SPaolo Bonzini * address spaces. Strip what is effectively the address space 6744c50d8ae3SPaolo Bonzini * modifier prior to checking for a wrap of the MMIO generation so 6745c50d8ae3SPaolo Bonzini * that a wrap in any address space is detected. 6746c50d8ae3SPaolo Bonzini */ 6747c50d8ae3SPaolo Bonzini gen &= ~((u64)KVM_ADDRESS_SPACE_NUM - 1); 6748c50d8ae3SPaolo Bonzini 6749c50d8ae3SPaolo Bonzini /* 6750c50d8ae3SPaolo Bonzini * The very rare case: if the MMIO generation number has wrapped, 6751c50d8ae3SPaolo Bonzini * zap all shadow pages. 6752c50d8ae3SPaolo Bonzini */ 6753c50d8ae3SPaolo Bonzini if (unlikely(gen == 0)) { 67548d20bd63SSean Christopherson kvm_debug_ratelimited("zapping shadow pages for mmio generation wraparound\n"); 6755c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6756c50d8ae3SPaolo Bonzini } 6757c50d8ae3SPaolo Bonzini } 6758c50d8ae3SPaolo Bonzini 6759f3d90f90SSean Christopherson static unsigned long mmu_shrink_scan(struct shrinker *shrink, 6760f3d90f90SSean Christopherson struct shrink_control *sc) 6761c50d8ae3SPaolo Bonzini { 6762c50d8ae3SPaolo Bonzini struct kvm *kvm; 6763c50d8ae3SPaolo Bonzini int nr_to_scan = sc->nr_to_scan; 6764c50d8ae3SPaolo Bonzini unsigned long freed = 0; 6765c50d8ae3SPaolo Bonzini 6766c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6767c50d8ae3SPaolo Bonzini 6768c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6769c50d8ae3SPaolo Bonzini int idx; 6770c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 6771c50d8ae3SPaolo Bonzini 6772c50d8ae3SPaolo Bonzini /* 6773c50d8ae3SPaolo Bonzini * Never scan more than sc->nr_to_scan VM instances. 6774c50d8ae3SPaolo Bonzini * Will not hit this condition practically since we do not try 6775c50d8ae3SPaolo Bonzini * to shrink more than one VM and it is very unlikely to see 6776c50d8ae3SPaolo Bonzini * !n_used_mmu_pages so many times. 6777c50d8ae3SPaolo Bonzini */ 6778c50d8ae3SPaolo Bonzini if (!nr_to_scan--) 6779c50d8ae3SPaolo Bonzini break; 6780c50d8ae3SPaolo Bonzini /* 6781c50d8ae3SPaolo Bonzini * n_used_mmu_pages is accessed without holding kvm->mmu_lock 6782c50d8ae3SPaolo Bonzini * here. We may skip a VM instance errorneosly, but we do not 6783c50d8ae3SPaolo Bonzini * want to shrink a VM that only started to populate its MMU 6784c50d8ae3SPaolo Bonzini * anyway. 6785c50d8ae3SPaolo Bonzini */ 6786c50d8ae3SPaolo Bonzini if (!kvm->arch.n_used_mmu_pages && 6787c50d8ae3SPaolo Bonzini !kvm_has_zapped_obsolete_pages(kvm)) 6788c50d8ae3SPaolo Bonzini continue; 6789c50d8ae3SPaolo Bonzini 6790c50d8ae3SPaolo Bonzini idx = srcu_read_lock(&kvm->srcu); 6791531810caSBen Gardon write_lock(&kvm->mmu_lock); 6792c50d8ae3SPaolo Bonzini 6793c50d8ae3SPaolo Bonzini if (kvm_has_zapped_obsolete_pages(kvm)) { 6794c50d8ae3SPaolo Bonzini kvm_mmu_commit_zap_page(kvm, 6795c50d8ae3SPaolo Bonzini &kvm->arch.zapped_obsolete_pages); 6796c50d8ae3SPaolo Bonzini goto unlock; 6797c50d8ae3SPaolo Bonzini } 6798c50d8ae3SPaolo Bonzini 6799ebdb292dSSean Christopherson freed = kvm_mmu_zap_oldest_mmu_pages(kvm, sc->nr_to_scan); 6800c50d8ae3SPaolo Bonzini 6801c50d8ae3SPaolo Bonzini unlock: 6802531810caSBen Gardon write_unlock(&kvm->mmu_lock); 6803c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, idx); 6804c50d8ae3SPaolo Bonzini 6805c50d8ae3SPaolo Bonzini /* 6806c50d8ae3SPaolo Bonzini * unfair on small ones 6807c50d8ae3SPaolo Bonzini * per-vm shrinkers cry out 6808c50d8ae3SPaolo Bonzini * sadness comes quickly 6809c50d8ae3SPaolo Bonzini */ 6810c50d8ae3SPaolo Bonzini list_move_tail(&kvm->vm_list, &vm_list); 6811c50d8ae3SPaolo Bonzini break; 6812c50d8ae3SPaolo Bonzini } 6813c50d8ae3SPaolo Bonzini 6814c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6815c50d8ae3SPaolo Bonzini return freed; 6816c50d8ae3SPaolo Bonzini } 6817c50d8ae3SPaolo Bonzini 6818f3d90f90SSean Christopherson static unsigned long mmu_shrink_count(struct shrinker *shrink, 6819f3d90f90SSean Christopherson struct shrink_control *sc) 6820c50d8ae3SPaolo Bonzini { 6821c50d8ae3SPaolo Bonzini return percpu_counter_read_positive(&kvm_total_used_mmu_pages); 6822c50d8ae3SPaolo Bonzini } 6823c50d8ae3SPaolo Bonzini 6824c50d8ae3SPaolo Bonzini static struct shrinker mmu_shrinker = { 6825c50d8ae3SPaolo Bonzini .count_objects = mmu_shrink_count, 6826c50d8ae3SPaolo Bonzini .scan_objects = mmu_shrink_scan, 6827c50d8ae3SPaolo Bonzini .seeks = DEFAULT_SEEKS * 10, 6828c50d8ae3SPaolo Bonzini }; 6829c50d8ae3SPaolo Bonzini 6830c50d8ae3SPaolo Bonzini static void mmu_destroy_caches(void) 6831c50d8ae3SPaolo Bonzini { 6832c50d8ae3SPaolo Bonzini kmem_cache_destroy(pte_list_desc_cache); 6833c50d8ae3SPaolo Bonzini kmem_cache_destroy(mmu_page_header_cache); 6834c50d8ae3SPaolo Bonzini } 6835c50d8ae3SPaolo Bonzini 6836c50d8ae3SPaolo Bonzini static bool get_nx_auto_mode(void) 6837c50d8ae3SPaolo Bonzini { 6838c50d8ae3SPaolo Bonzini /* Return true when CPU has the bug, and mitigations are ON */ 6839c50d8ae3SPaolo Bonzini return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off(); 6840c50d8ae3SPaolo Bonzini } 6841c50d8ae3SPaolo Bonzini 6842c50d8ae3SPaolo Bonzini static void __set_nx_huge_pages(bool val) 6843c50d8ae3SPaolo Bonzini { 6844c50d8ae3SPaolo Bonzini nx_huge_pages = itlb_multihit_kvm_mitigation = val; 6845c50d8ae3SPaolo Bonzini } 6846c50d8ae3SPaolo Bonzini 6847c50d8ae3SPaolo Bonzini static int set_nx_huge_pages(const char *val, const struct kernel_param *kp) 6848c50d8ae3SPaolo Bonzini { 6849c50d8ae3SPaolo Bonzini bool old_val = nx_huge_pages; 6850c50d8ae3SPaolo Bonzini bool new_val; 6851c50d8ae3SPaolo Bonzini 6852c50d8ae3SPaolo Bonzini /* In "auto" mode deploy workaround only if CPU has the bug. */ 6853c50d8ae3SPaolo Bonzini if (sysfs_streq(val, "off")) 6854c50d8ae3SPaolo Bonzini new_val = 0; 6855c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "force")) 6856c50d8ae3SPaolo Bonzini new_val = 1; 6857c50d8ae3SPaolo Bonzini else if (sysfs_streq(val, "auto")) 6858c50d8ae3SPaolo Bonzini new_val = get_nx_auto_mode(); 685911b36fe7SChristophe JAILLET else if (kstrtobool(val, &new_val) < 0) 6860c50d8ae3SPaolo Bonzini return -EINVAL; 6861c50d8ae3SPaolo Bonzini 6862c50d8ae3SPaolo Bonzini __set_nx_huge_pages(new_val); 6863c50d8ae3SPaolo Bonzini 6864c50d8ae3SPaolo Bonzini if (new_val != old_val) { 6865c50d8ae3SPaolo Bonzini struct kvm *kvm; 6866c50d8ae3SPaolo Bonzini 6867c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 6868c50d8ae3SPaolo Bonzini 6869c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) { 6870c50d8ae3SPaolo Bonzini mutex_lock(&kvm->slots_lock); 6871c50d8ae3SPaolo Bonzini kvm_mmu_zap_all_fast(kvm); 6872c50d8ae3SPaolo Bonzini mutex_unlock(&kvm->slots_lock); 6873c50d8ae3SPaolo Bonzini 687455c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 6875c50d8ae3SPaolo Bonzini } 6876c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 6877c50d8ae3SPaolo Bonzini } 6878c50d8ae3SPaolo Bonzini 6879c50d8ae3SPaolo Bonzini return 0; 6880c50d8ae3SPaolo Bonzini } 6881c50d8ae3SPaolo Bonzini 68821d0e8480SSean Christopherson /* 68831d0e8480SSean Christopherson * nx_huge_pages needs to be resolved to true/false when kvm.ko is loaded, as 68841d0e8480SSean Christopherson * its default value of -1 is technically undefined behavior for a boolean. 6885c3e0c8c2SSean Christopherson * Forward the module init call to SPTE code so that it too can handle module 6886c3e0c8c2SSean Christopherson * params that need to be resolved/snapshot. 68871d0e8480SSean Christopherson */ 6888982bae43SSean Christopherson void __init kvm_mmu_x86_module_init(void) 6889c50d8ae3SPaolo Bonzini { 6890c50d8ae3SPaolo Bonzini if (nx_huge_pages == -1) 6891c50d8ae3SPaolo Bonzini __set_nx_huge_pages(get_nx_auto_mode()); 6892c3e0c8c2SSean Christopherson 68931f98f2bdSDavid Matlack /* 68941f98f2bdSDavid Matlack * Snapshot userspace's desire to enable the TDP MMU. Whether or not the 68951f98f2bdSDavid Matlack * TDP MMU is actually enabled is determined in kvm_configure_mmu() 68961f98f2bdSDavid Matlack * when the vendor module is loaded. 68971f98f2bdSDavid Matlack */ 68981f98f2bdSDavid Matlack tdp_mmu_allowed = tdp_mmu_enabled; 68991f98f2bdSDavid Matlack 6900c3e0c8c2SSean Christopherson kvm_mmu_spte_module_init(); 69011d0e8480SSean Christopherson } 69021d0e8480SSean Christopherson 69031d0e8480SSean Christopherson /* 69041d0e8480SSean Christopherson * The bulk of the MMU initialization is deferred until the vendor module is 69051d0e8480SSean Christopherson * loaded as many of the masks/values may be modified by VMX or SVM, i.e. need 69061d0e8480SSean Christopherson * to be reset when a potentially different vendor module is loaded. 69071d0e8480SSean Christopherson */ 69081d0e8480SSean Christopherson int kvm_mmu_vendor_module_init(void) 69091d0e8480SSean Christopherson { 69101d0e8480SSean Christopherson int ret = -ENOMEM; 6911c50d8ae3SPaolo Bonzini 6912c50d8ae3SPaolo Bonzini /* 6913c50d8ae3SPaolo Bonzini * MMU roles use union aliasing which is, generally speaking, an 6914c50d8ae3SPaolo Bonzini * undefined behavior. However, we supposedly know how compilers behave 6915c50d8ae3SPaolo Bonzini * and the current status quo is unlikely to change. Guardians below are 6916c50d8ae3SPaolo Bonzini * supposed to let us know if the assumption becomes false. 6917c50d8ae3SPaolo Bonzini */ 6918c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); 6919c50d8ae3SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); 69207a7ae829SPaolo Bonzini BUILD_BUG_ON(sizeof(union kvm_cpu_role) != sizeof(u64)); 6921c50d8ae3SPaolo Bonzini 6922c50d8ae3SPaolo Bonzini kvm_mmu_reset_all_pte_masks(); 6923c50d8ae3SPaolo Bonzini 6924c50d8ae3SPaolo Bonzini pte_list_desc_cache = kmem_cache_create("pte_list_desc", 6925c50d8ae3SPaolo Bonzini sizeof(struct pte_list_desc), 6926c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6927c50d8ae3SPaolo Bonzini if (!pte_list_desc_cache) 6928c50d8ae3SPaolo Bonzini goto out; 6929c50d8ae3SPaolo Bonzini 6930c50d8ae3SPaolo Bonzini mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", 6931c50d8ae3SPaolo Bonzini sizeof(struct kvm_mmu_page), 6932c50d8ae3SPaolo Bonzini 0, SLAB_ACCOUNT, NULL); 6933c50d8ae3SPaolo Bonzini if (!mmu_page_header_cache) 6934c50d8ae3SPaolo Bonzini goto out; 6935c50d8ae3SPaolo Bonzini 6936c50d8ae3SPaolo Bonzini if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) 6937c50d8ae3SPaolo Bonzini goto out; 6938c50d8ae3SPaolo Bonzini 6939e33c267aSRoman Gushchin ret = register_shrinker(&mmu_shrinker, "x86-mmu"); 6940c50d8ae3SPaolo Bonzini if (ret) 6941d7c9bfb9SMiaohe Lin goto out_shrinker; 6942c50d8ae3SPaolo Bonzini 6943c50d8ae3SPaolo Bonzini return 0; 6944c50d8ae3SPaolo Bonzini 6945d7c9bfb9SMiaohe Lin out_shrinker: 6946d7c9bfb9SMiaohe Lin percpu_counter_destroy(&kvm_total_used_mmu_pages); 6947c50d8ae3SPaolo Bonzini out: 6948c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6949c50d8ae3SPaolo Bonzini return ret; 6950c50d8ae3SPaolo Bonzini } 6951c50d8ae3SPaolo Bonzini 6952c50d8ae3SPaolo Bonzini void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 6953c50d8ae3SPaolo Bonzini { 6954c50d8ae3SPaolo Bonzini kvm_mmu_unload(vcpu); 6955c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.root_mmu); 6956c50d8ae3SPaolo Bonzini free_mmu_pages(&vcpu->arch.guest_mmu); 6957c50d8ae3SPaolo Bonzini mmu_free_memory_caches(vcpu); 6958c50d8ae3SPaolo Bonzini } 6959c50d8ae3SPaolo Bonzini 69601d0e8480SSean Christopherson void kvm_mmu_vendor_module_exit(void) 6961c50d8ae3SPaolo Bonzini { 6962c50d8ae3SPaolo Bonzini mmu_destroy_caches(); 6963c50d8ae3SPaolo Bonzini percpu_counter_destroy(&kvm_total_used_mmu_pages); 6964c50d8ae3SPaolo Bonzini unregister_shrinker(&mmu_shrinker); 6965c50d8ae3SPaolo Bonzini } 6966c50d8ae3SPaolo Bonzini 6967f47491d7SSean Christopherson /* 6968f47491d7SSean Christopherson * Calculate the effective recovery period, accounting for '0' meaning "let KVM 6969f47491d7SSean Christopherson * select a halving time of 1 hour". Returns true if recovery is enabled. 6970f47491d7SSean Christopherson */ 6971f47491d7SSean Christopherson static bool calc_nx_huge_pages_recovery_period(uint *period) 6972f47491d7SSean Christopherson { 6973f47491d7SSean Christopherson /* 6974f47491d7SSean Christopherson * Use READ_ONCE to get the params, this may be called outside of the 6975f47491d7SSean Christopherson * param setters, e.g. by the kthread to compute its next timeout. 6976f47491d7SSean Christopherson */ 6977f47491d7SSean Christopherson bool enabled = READ_ONCE(nx_huge_pages); 6978f47491d7SSean Christopherson uint ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 6979f47491d7SSean Christopherson 6980f47491d7SSean Christopherson if (!enabled || !ratio) 6981f47491d7SSean Christopherson return false; 6982f47491d7SSean Christopherson 6983f47491d7SSean Christopherson *period = READ_ONCE(nx_huge_pages_recovery_period_ms); 6984f47491d7SSean Christopherson if (!*period) { 6985f47491d7SSean Christopherson /* Make sure the period is not less than one second. */ 6986f47491d7SSean Christopherson ratio = min(ratio, 3600u); 6987f47491d7SSean Christopherson *period = 60 * 60 * 1000 / ratio; 6988f47491d7SSean Christopherson } 6989f47491d7SSean Christopherson return true; 6990f47491d7SSean Christopherson } 6991f47491d7SSean Christopherson 69924dfe4f40SJunaid Shahid static int set_nx_huge_pages_recovery_param(const char *val, const struct kernel_param *kp) 6993c50d8ae3SPaolo Bonzini { 69944dfe4f40SJunaid Shahid bool was_recovery_enabled, is_recovery_enabled; 69954dfe4f40SJunaid Shahid uint old_period, new_period; 6996c50d8ae3SPaolo Bonzini int err; 6997c50d8ae3SPaolo Bonzini 6998f47491d7SSean Christopherson was_recovery_enabled = calc_nx_huge_pages_recovery_period(&old_period); 69994dfe4f40SJunaid Shahid 7000c50d8ae3SPaolo Bonzini err = param_set_uint(val, kp); 7001c50d8ae3SPaolo Bonzini if (err) 7002c50d8ae3SPaolo Bonzini return err; 7003c50d8ae3SPaolo Bonzini 7004f47491d7SSean Christopherson is_recovery_enabled = calc_nx_huge_pages_recovery_period(&new_period); 70054dfe4f40SJunaid Shahid 7006f47491d7SSean Christopherson if (is_recovery_enabled && 70074dfe4f40SJunaid Shahid (!was_recovery_enabled || old_period > new_period)) { 7008c50d8ae3SPaolo Bonzini struct kvm *kvm; 7009c50d8ae3SPaolo Bonzini 7010c50d8ae3SPaolo Bonzini mutex_lock(&kvm_lock); 7011c50d8ae3SPaolo Bonzini 7012c50d8ae3SPaolo Bonzini list_for_each_entry(kvm, &vm_list, vm_list) 701355c510e2SSean Christopherson wake_up_process(kvm->arch.nx_huge_page_recovery_thread); 7014c50d8ae3SPaolo Bonzini 7015c50d8ae3SPaolo Bonzini mutex_unlock(&kvm_lock); 7016c50d8ae3SPaolo Bonzini } 7017c50d8ae3SPaolo Bonzini 7018c50d8ae3SPaolo Bonzini return err; 7019c50d8ae3SPaolo Bonzini } 7020c50d8ae3SPaolo Bonzini 702155c510e2SSean Christopherson static void kvm_recover_nx_huge_pages(struct kvm *kvm) 7022c50d8ae3SPaolo Bonzini { 7023ade74e14SSean Christopherson unsigned long nx_lpage_splits = kvm->stat.nx_lpage_splits; 7024eb298605SDavid Matlack struct kvm_memory_slot *slot; 7025c50d8ae3SPaolo Bonzini int rcu_idx; 7026c50d8ae3SPaolo Bonzini struct kvm_mmu_page *sp; 7027c50d8ae3SPaolo Bonzini unsigned int ratio; 7028c50d8ae3SPaolo Bonzini LIST_HEAD(invalid_list); 7029048f4980SSean Christopherson bool flush = false; 7030c50d8ae3SPaolo Bonzini ulong to_zap; 7031c50d8ae3SPaolo Bonzini 7032c50d8ae3SPaolo Bonzini rcu_idx = srcu_read_lock(&kvm->srcu); 7033531810caSBen Gardon write_lock(&kvm->mmu_lock); 7034c50d8ae3SPaolo Bonzini 7035bb95dfb9SSean Christopherson /* 7036bb95dfb9SSean Christopherson * Zapping TDP MMU shadow pages, including the remote TLB flush, must 7037bb95dfb9SSean Christopherson * be done under RCU protection, because the pages are freed via RCU 7038bb95dfb9SSean Christopherson * callback. 7039bb95dfb9SSean Christopherson */ 7040bb95dfb9SSean Christopherson rcu_read_lock(); 7041bb95dfb9SSean Christopherson 7042c50d8ae3SPaolo Bonzini ratio = READ_ONCE(nx_huge_pages_recovery_ratio); 7043ade74e14SSean Christopherson to_zap = ratio ? DIV_ROUND_UP(nx_lpage_splits, ratio) : 0; 70447d919c7aSSean Christopherson for ( ; to_zap; --to_zap) { 704555c510e2SSean Christopherson if (list_empty(&kvm->arch.possible_nx_huge_pages)) 70467d919c7aSSean Christopherson break; 70477d919c7aSSean Christopherson 7048c50d8ae3SPaolo Bonzini /* 7049c50d8ae3SPaolo Bonzini * We use a separate list instead of just using active_mmu_pages 705055c510e2SSean Christopherson * because the number of shadow pages that be replaced with an 705155c510e2SSean Christopherson * NX huge page is expected to be relatively small compared to 705255c510e2SSean Christopherson * the total number of shadow pages. And because the TDP MMU 705355c510e2SSean Christopherson * doesn't use active_mmu_pages. 7054c50d8ae3SPaolo Bonzini */ 705555c510e2SSean Christopherson sp = list_first_entry(&kvm->arch.possible_nx_huge_pages, 7056c50d8ae3SPaolo Bonzini struct kvm_mmu_page, 705755c510e2SSean Christopherson possible_nx_huge_page_link); 705855c510e2SSean Christopherson WARN_ON_ONCE(!sp->nx_huge_page_disallowed); 7059eb298605SDavid Matlack WARN_ON_ONCE(!sp->role.direct); 7060eb298605SDavid Matlack 7061eb298605SDavid Matlack /* 7062eb298605SDavid Matlack * Unaccount and do not attempt to recover any NX Huge Pages 7063eb298605SDavid Matlack * that are being dirty tracked, as they would just be faulted 7064eb298605SDavid Matlack * back in as 4KiB pages. The NX Huge Pages in this slot will be 7065eb298605SDavid Matlack * recovered, along with all the other huge pages in the slot, 7066eb298605SDavid Matlack * when dirty logging is disabled. 70676c7b2202SPaolo Bonzini * 70686c7b2202SPaolo Bonzini * Since gfn_to_memslot() is relatively expensive, it helps to 70696c7b2202SPaolo Bonzini * skip it if it the test cannot possibly return true. On the 70706c7b2202SPaolo Bonzini * other hand, if any memslot has logging enabled, chances are 70716c7b2202SPaolo Bonzini * good that all of them do, in which case unaccount_nx_huge_page() 70726c7b2202SPaolo Bonzini * is much cheaper than zapping the page. 70736c7b2202SPaolo Bonzini * 70746c7b2202SPaolo Bonzini * If a memslot update is in progress, reading an incorrect value 70756c7b2202SPaolo Bonzini * of kvm->nr_memslots_dirty_logging is not a problem: if it is 70766c7b2202SPaolo Bonzini * becoming zero, gfn_to_memslot() will be done unnecessarily; if 70776c7b2202SPaolo Bonzini * it is becoming nonzero, the page will be zapped unnecessarily. 70786c7b2202SPaolo Bonzini * Either way, this only affects efficiency in racy situations, 70796c7b2202SPaolo Bonzini * and not correctness. 7080eb298605SDavid Matlack */ 70816c7b2202SPaolo Bonzini slot = NULL; 70826c7b2202SPaolo Bonzini if (atomic_read(&kvm->nr_memslots_dirty_logging)) { 70836c7b2202SPaolo Bonzini slot = gfn_to_memslot(kvm, sp->gfn); 70846c7b2202SPaolo Bonzini WARN_ON_ONCE(!slot); 708529cf0f50SBen Gardon } 7086c50d8ae3SPaolo Bonzini 7087eb298605SDavid Matlack if (slot && kvm_slot_dirty_track_enabled(slot)) 7088eb298605SDavid Matlack unaccount_nx_huge_page(kvm, sp); 7089eb298605SDavid Matlack else if (is_tdp_mmu_page(sp)) 7090c50d8ae3SPaolo Bonzini flush |= kvm_tdp_mmu_zap_sp(kvm, sp); 70913a056757SSean Christopherson else 7092c50d8ae3SPaolo Bonzini kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); 709355c510e2SSean Christopherson WARN_ON_ONCE(sp->nx_huge_page_disallowed); 7094c50d8ae3SPaolo Bonzini 7095531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 7096048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7097bb95dfb9SSean Christopherson rcu_read_unlock(); 7098bb95dfb9SSean Christopherson 7099531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 7100048f4980SSean Christopherson flush = false; 7101bb95dfb9SSean Christopherson 7102bb95dfb9SSean Christopherson rcu_read_lock(); 7103c50d8ae3SPaolo Bonzini } 7104c50d8ae3SPaolo Bonzini } 7105048f4980SSean Christopherson kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); 7106c50d8ae3SPaolo Bonzini 7107bb95dfb9SSean Christopherson rcu_read_unlock(); 7108bb95dfb9SSean Christopherson 7109531810caSBen Gardon write_unlock(&kvm->mmu_lock); 7110c50d8ae3SPaolo Bonzini srcu_read_unlock(&kvm->srcu, rcu_idx); 7111c50d8ae3SPaolo Bonzini } 7112c50d8ae3SPaolo Bonzini 711355c510e2SSean Christopherson static long get_nx_huge_page_recovery_timeout(u64 start_time) 7114c50d8ae3SPaolo Bonzini { 7115f47491d7SSean Christopherson bool enabled; 7116f47491d7SSean Christopherson uint period; 71174dfe4f40SJunaid Shahid 7118f47491d7SSean Christopherson enabled = calc_nx_huge_pages_recovery_period(&period); 71194dfe4f40SJunaid Shahid 7120f47491d7SSean Christopherson return enabled ? start_time + msecs_to_jiffies(period) - get_jiffies_64() 7121c50d8ae3SPaolo Bonzini : MAX_SCHEDULE_TIMEOUT; 7122c50d8ae3SPaolo Bonzini } 7123c50d8ae3SPaolo Bonzini 712455c510e2SSean Christopherson static int kvm_nx_huge_page_recovery_worker(struct kvm *kvm, uintptr_t data) 7125c50d8ae3SPaolo Bonzini { 7126c50d8ae3SPaolo Bonzini u64 start_time; 7127c50d8ae3SPaolo Bonzini long remaining_time; 7128c50d8ae3SPaolo Bonzini 7129c50d8ae3SPaolo Bonzini while (true) { 7130c50d8ae3SPaolo Bonzini start_time = get_jiffies_64(); 713155c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7132c50d8ae3SPaolo Bonzini 7133c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7134c50d8ae3SPaolo Bonzini while (!kthread_should_stop() && remaining_time > 0) { 7135c50d8ae3SPaolo Bonzini schedule_timeout(remaining_time); 713655c510e2SSean Christopherson remaining_time = get_nx_huge_page_recovery_timeout(start_time); 7137c50d8ae3SPaolo Bonzini set_current_state(TASK_INTERRUPTIBLE); 7138c50d8ae3SPaolo Bonzini } 7139c50d8ae3SPaolo Bonzini 7140c50d8ae3SPaolo Bonzini set_current_state(TASK_RUNNING); 7141c50d8ae3SPaolo Bonzini 7142c50d8ae3SPaolo Bonzini if (kthread_should_stop()) 7143c50d8ae3SPaolo Bonzini return 0; 7144c50d8ae3SPaolo Bonzini 714555c510e2SSean Christopherson kvm_recover_nx_huge_pages(kvm); 7146c50d8ae3SPaolo Bonzini } 7147c50d8ae3SPaolo Bonzini } 7148c50d8ae3SPaolo Bonzini 7149c50d8ae3SPaolo Bonzini int kvm_mmu_post_init_vm(struct kvm *kvm) 7150c50d8ae3SPaolo Bonzini { 7151c50d8ae3SPaolo Bonzini int err; 7152c50d8ae3SPaolo Bonzini 715355c510e2SSean Christopherson err = kvm_vm_create_worker_thread(kvm, kvm_nx_huge_page_recovery_worker, 0, 7154c50d8ae3SPaolo Bonzini "kvm-nx-lpage-recovery", 715555c510e2SSean Christopherson &kvm->arch.nx_huge_page_recovery_thread); 7156c50d8ae3SPaolo Bonzini if (!err) 715755c510e2SSean Christopherson kthread_unpark(kvm->arch.nx_huge_page_recovery_thread); 7158c50d8ae3SPaolo Bonzini 7159c50d8ae3SPaolo Bonzini return err; 7160c50d8ae3SPaolo Bonzini } 7161c50d8ae3SPaolo Bonzini 7162c50d8ae3SPaolo Bonzini void kvm_mmu_pre_destroy_vm(struct kvm *kvm) 7163c50d8ae3SPaolo Bonzini { 716455c510e2SSean Christopherson if (kvm->arch.nx_huge_page_recovery_thread) 716555c510e2SSean Christopherson kthread_stop(kvm->arch.nx_huge_page_recovery_thread); 7166c50d8ae3SPaolo Bonzini } 7167