diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 534 |
1 files changed, 444 insertions, 90 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index d594690d8b95..a282321329b5 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -178,7 +178,24 @@ struct kvm_shadow_walk_iterator { unsigned index; }; -#define for_each_shadow_entry(_vcpu, _addr, _walker) \ +static const union kvm_mmu_page_role mmu_base_role_mask = { + .cr0_wp = 1, + .cr4_pae = 1, + .nxe = 1, + .smep_andnot_wp = 1, + .smap_andnot_wp = 1, + .smm = 1, + .guest_mode = 1, + .ad_disabled = 1, +}; + +#define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker) \ + for (shadow_walk_init_using_root(&(_walker), (_vcpu), \ + (_root), (_addr)); \ + shadow_walk_okay(&(_walker)); \ + shadow_walk_next(&(_walker))) + +#define for_each_shadow_entry(_vcpu, _addr, _walker) \ for (shadow_walk_init(&(_walker), _vcpu, _addr); \ shadow_walk_okay(&(_walker)); \ shadow_walk_next(&(_walker))) @@ -221,7 +238,20 @@ static const u64 shadow_acc_track_saved_bits_mask = PT64_EPT_READABLE_MASK | PT64_EPT_EXECUTABLE_MASK; static const u64 shadow_acc_track_saved_bits_shift = PT64_SECOND_AVAIL_BITS_SHIFT; +/* + * This mask must be set on all non-zero Non-Present or Reserved SPTEs in order + * to guard against L1TF attacks. + */ +static u64 __read_mostly shadow_nonpresent_or_rsvd_mask; + +/* + * The number of high-order 1 bits to use in the mask above. + */ +static const u64 shadow_nonpresent_or_rsvd_mask_len = 5; + static void mmu_spte_set(u64 *sptep, u64 spte); +static union kvm_mmu_page_role +kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu); void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value) { @@ -308,9 +338,13 @@ static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, { unsigned int gen = kvm_current_mmio_generation(vcpu); u64 mask = generation_mmio_spte_mask(gen); + u64 gpa = gfn << PAGE_SHIFT; access &= ACC_WRITE_MASK | ACC_USER_MASK; - mask |= shadow_mmio_value | access | gfn << PAGE_SHIFT; + mask |= shadow_mmio_value | access; + mask |= gpa | shadow_nonpresent_or_rsvd_mask; + mask |= (gpa & shadow_nonpresent_or_rsvd_mask) + << shadow_nonpresent_or_rsvd_mask_len; trace_mark_mmio_spte(sptep, gfn, access, gen); mmu_spte_set(sptep, mask); @@ -323,8 +357,14 @@ static bool is_mmio_spte(u64 spte) static gfn_t get_mmio_spte_gfn(u64 spte) { - u64 mask = generation_mmio_spte_mask(MMIO_GEN_MASK) | shadow_mmio_mask; - return (spte & ~mask) >> PAGE_SHIFT; + u64 mask = generation_mmio_spte_mask(MMIO_GEN_MASK) | shadow_mmio_mask | + shadow_nonpresent_or_rsvd_mask; + u64 gpa = spte & ~mask; + + gpa |= (spte >> shadow_nonpresent_or_rsvd_mask_len) + & shadow_nonpresent_or_rsvd_mask; + + return gpa >> PAGE_SHIFT; } static unsigned get_mmio_spte_access(u64 spte) @@ -381,7 +421,7 @@ void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, } EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes); -static void kvm_mmu_clear_all_pte_masks(void) +static void kvm_mmu_reset_all_pte_masks(void) { shadow_user_mask = 0; shadow_accessed_mask = 0; @@ -391,6 +431,18 @@ static void kvm_mmu_clear_all_pte_masks(void) shadow_mmio_mask = 0; shadow_present_mask = 0; shadow_acc_track_mask = 0; + + /* + * If the CPU has 46 or less physical address bits, then set an + * appropriate mask to guard against L1TF attacks. Otherwise, it is + * assumed that the CPU is not vulnerable to L1TF. + */ + if (boot_cpu_data.x86_phys_bits < + 52 - shadow_nonpresent_or_rsvd_mask_len) + shadow_nonpresent_or_rsvd_mask = + rsvd_bits(boot_cpu_data.x86_phys_bits - + shadow_nonpresent_or_rsvd_mask_len, + boot_cpu_data.x86_phys_bits - 1); } static int is_cpuid_PSE36(void) @@ -890,7 +942,7 @@ static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache, if (cache->nobjs >= min) return 0; while (cache->nobjs < ARRAY_SIZE(cache->objects)) { - page = (void *)__get_free_page(GFP_KERNEL); + page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT); if (!page) return -ENOMEM; cache->objects[cache->nobjs++] = page; @@ -1986,7 +2038,7 @@ static int nonpaging_sync_page(struct kvm_vcpu *vcpu, return 0; } -static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva) +static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root) { } @@ -2117,12 +2169,8 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm, static bool __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, struct list_head *invalid_list) { - if (sp->role.cr4_pae != !!is_pae(vcpu)) { - kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); - return false; - } - - if (vcpu->arch.mmu.sync_page(vcpu, sp) == 0) { + if (sp->role.cr4_pae != !!is_pae(vcpu) + || vcpu->arch.mmu.sync_page(vcpu, sp) == 0) { kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); return false; } @@ -2392,11 +2440,12 @@ out: return sp; } -static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, - struct kvm_vcpu *vcpu, u64 addr) +static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator, + struct kvm_vcpu *vcpu, hpa_t root, + u64 addr) { iterator->addr = addr; - iterator->shadow_addr = vcpu->arch.mmu.root_hpa; + iterator->shadow_addr = root; iterator->level = vcpu->arch.mmu.shadow_root_level; if (iterator->level == PT64_ROOT_4LEVEL && @@ -2405,6 +2454,12 @@ static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, --iterator->level; if (iterator->level == PT32E_ROOT_LEVEL) { + /* + * prev_root is currently only used for 64-bit hosts. So only + * the active root_hpa is valid here. + */ + BUG_ON(root != vcpu->arch.mmu.root_hpa); + iterator->shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3]; iterator->shadow_addr &= PT64_BASE_ADDR_MASK; @@ -2414,6 +2469,13 @@ static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, } } +static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, + struct kvm_vcpu *vcpu, u64 addr) +{ + shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu.root_hpa, + addr); +} + static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) { if (iterator->level < PT_PAGE_TABLE_LEVEL) @@ -2702,6 +2764,45 @@ static bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_unsync_page(vcpu, sp); } + /* + * We need to ensure that the marking of unsync pages is visible + * before the SPTE is updated to allow writes because + * kvm_mmu_sync_roots() checks the unsync flags without holding + * the MMU lock and so can race with this. If the SPTE was updated + * before the page had been marked as unsync-ed, something like the + * following could happen: + * + * CPU 1 CPU 2 + * --------------------------------------------------------------------- + * 1.2 Host updates SPTE + * to be writable + * 2.1 Guest writes a GPTE for GVA X. + * (GPTE being in the guest page table shadowed + * by the SP from CPU 1.) + * This reads SPTE during the page table walk. + * Since SPTE.W is read as 1, there is no + * fault. + * + * 2.2 Guest issues TLB flush. + * That causes a VM Exit. + * + * 2.3 kvm_mmu_sync_pages() reads sp->unsync. + * Since it is false, so it just returns. + * + * 2.4 Guest accesses GVA X. + * Since the mapping in the SP was not updated, + * so the old mapping for GVA X incorrectly + * gets used. + * 1.1 Host marks SP + * as unsync + * (sp->unsync = true) + * + * The write barrier below ensures that 1.1 happens before 1.2 and thus + * the situation in 2.4 does not arise. The implicit barrier in 2.2 + * pairs with this write barrier. + */ + smp_wmb(); + return false; } @@ -2724,6 +2825,10 @@ static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) return true; } +/* Bits which may be returned by set_spte() */ +#define SET_SPTE_WRITE_PROTECTED_PT BIT(0) +#define SET_SPTE_NEED_REMOTE_TLB_FLUSH BIT(1) + static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access, int level, gfn_t gfn, kvm_pfn_t pfn, bool speculative, @@ -2800,7 +2905,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, if (mmu_need_write_protect(vcpu, gfn, can_unsync)) { pgprintk("%s: found shadow page for %llx, marking ro\n", __func__, gfn); - ret = 1; + ret |= SET_SPTE_WRITE_PROTECTED_PT; pte_access &= ~ACC_WRITE_MASK; spte &= ~(PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE); } @@ -2816,7 +2921,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, set_pte: if (mmu_spte_update(sptep, spte)) - kvm_flush_remote_tlbs(vcpu->kvm); + ret |= SET_SPTE_NEED_REMOTE_TLB_FLUSH; done: return ret; } @@ -2827,7 +2932,9 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access, { int was_rmapped = 0; int rmap_count; + int set_spte_ret; int ret = RET_PF_RETRY; + bool flush = false; pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, *sptep, write_fault, gfn); @@ -2844,22 +2951,25 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access, child = page_header(pte & PT64_BASE_ADDR_MASK); drop_parent_pte(child, sptep); - kvm_flush_remote_tlbs(vcpu->kvm); + flush = true; } else if (pfn != spte_to_pfn(*sptep)) { pgprintk("hfn old %llx new %llx\n", spte_to_pfn(*sptep), pfn); drop_spte(vcpu->kvm, sptep); - kvm_flush_remote_tlbs(vcpu->kvm); + flush = true; } else was_rmapped = 1; } - if (set_spte(vcpu, sptep, pte_access, level, gfn, pfn, speculative, - true, host_writable)) { + set_spte_ret = set_spte(vcpu, sptep, pte_access, level, gfn, pfn, + speculative, true, host_writable); + if (set_spte_ret & SET_SPTE_WRITE_PROTECTED_PT) { if (write_fault) ret = RET_PF_EMULATE; kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); } + if (set_spte_ret & SET_SPTE_NEED_REMOTE_TLB_FLUSH || flush) + kvm_flush_remote_tlbs(vcpu->kvm); if (unlikely(is_mmio_spte(*sptep))) ret = RET_PF_EMULATE; @@ -3358,26 +3468,47 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, *root_hpa = INVALID_PAGE; } -void kvm_mmu_free_roots(struct kvm_vcpu *vcpu) +/* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ +void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, ulong roots_to_free) { int i; LIST_HEAD(invalid_list); struct kvm_mmu *mmu = &vcpu->arch.mmu; + bool free_active_root = roots_to_free & KVM_MMU_ROOT_CURRENT; - if (!VALID_PAGE(mmu->root_hpa)) - return; + BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); + + /* Before acquiring the MMU lock, see if we need to do any real work. */ + if (!(free_active_root && VALID_PAGE(mmu->root_hpa))) { + for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) + if ((roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) && + VALID_PAGE(mmu->prev_roots[i].hpa)) + break; + + if (i == KVM_MMU_NUM_PREV_ROOTS) + return; + } spin_lock(&vcpu->kvm->mmu_lock); - if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL && - (mmu->root_level >= PT64_ROOT_4LEVEL || mmu->direct_map)) { - mmu_free_root_page(vcpu->kvm, &mmu->root_hpa, &invalid_list); - } else { - for (i = 0; i < 4; ++i) - if (mmu->pae_root[i] != 0) - mmu_free_root_page(vcpu->kvm, &mmu->pae_root[i], - &invalid_list); - mmu->root_hpa = INVALID_PAGE; + for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) + if (roots_to_free & KVM_MMU_ROOT_PREVIOUS(i)) + mmu_free_root_page(vcpu->kvm, &mmu->prev_roots[i].hpa, + &invalid_list); + + if (free_active_root) { + if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL && + (mmu->root_level >= PT64_ROOT_4LEVEL || mmu->direct_map)) { + mmu_free_root_page(vcpu->kvm, &mmu->root_hpa, + &invalid_list); + } else { + for (i = 0; i < 4; ++i) + if (mmu->pae_root[i] != 0) + mmu_free_root_page(vcpu->kvm, + &mmu->pae_root[i], + &invalid_list); + mmu->root_hpa = INVALID_PAGE; + } } kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); @@ -3546,7 +3677,7 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu) return mmu_alloc_shadow_roots(vcpu); } -static void mmu_sync_roots(struct kvm_vcpu *vcpu) +void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) { int i; struct kvm_mmu_page *sp; @@ -3558,14 +3689,39 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu) return; vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); - kvm_mmu_audit(vcpu, AUDIT_PRE_SYNC); + if (vcpu->arch.mmu.root_level >= PT64_ROOT_4LEVEL) { hpa_t root = vcpu->arch.mmu.root_hpa; + sp = page_header(root); + + /* + * Even if another CPU was marking the SP as unsync-ed + * simultaneously, any guest page table changes are not + * guaranteed to be visible anyway until this VCPU issues a TLB + * flush strictly after those changes are made. We only need to + * ensure that the other CPU sets these flags before any actual + * changes to the page tables are made. The comments in + * mmu_need_write_protect() describe what could go wrong if this + * requirement isn't satisfied. + */ + if (!smp_load_acquire(&sp->unsync) && + !smp_load_acquire(&sp->unsync_children)) + return; + + spin_lock(&vcpu->kvm->mmu_lock); + kvm_mmu_audit(vcpu, AUDIT_PRE_SYNC); + mmu_sync_children(vcpu, sp); + kvm_mmu_audit(vcpu, AUDIT_POST_SYNC); + spin_unlock(&vcpu->kvm->mmu_lock); return; } + + spin_lock(&vcpu->kvm->mmu_lock); + kvm_mmu_audit(vcpu, AUDIT_PRE_SYNC); + for (i = 0; i < 4; ++i) { hpa_t root = vcpu->arch.mmu.pae_root[i]; @@ -3575,13 +3731,8 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu) mmu_sync_children(vcpu, sp); } } - kvm_mmu_audit(vcpu, AUDIT_POST_SYNC); -} -void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) -{ - spin_lock(&vcpu->kvm->mmu_lock); - mmu_sync_roots(vcpu); + kvm_mmu_audit(vcpu, AUDIT_POST_SYNC); spin_unlock(&vcpu->kvm->mmu_lock); } EXPORT_SYMBOL_GPL(kvm_mmu_sync_roots); @@ -3840,6 +3991,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, { int r = 1; + vcpu->arch.l1tf_flush_l1d = true; switch (vcpu->arch.apf.host_apf_reason) { default: trace_kvm_page_fault(fault_address, error_code); @@ -3947,16 +4099,107 @@ static void nonpaging_init_context(struct kvm_vcpu *vcpu, context->update_pte = nonpaging_update_pte; context->root_level = 0; context->shadow_root_level = PT32E_ROOT_LEVEL; - context->root_hpa = INVALID_PAGE; context->direct_map = true; context->nx = false; } -void kvm_mmu_new_cr3(struct kvm_vcpu *vcpu) +/* + * Find out if a previously cached root matching the new CR3/role is available. + * The current root is also inserted into the cache. + * If a matching root was found, it is assigned to kvm_mmu->root_hpa and true is + * returned. + * Otherwise, the LRU root from the cache is assigned to kvm_mmu->root_hpa and + * false is returned. This root should now be freed by the caller. + */ +static bool cached_root_available(struct kvm_vcpu *vcpu, gpa_t new_cr3, + union kvm_mmu_page_role new_role) +{ + uint i; + struct kvm_mmu_root_info root; + struct kvm_mmu *mmu = &vcpu->arch.mmu; + + root.cr3 = mmu->get_cr3(vcpu); + root.hpa = mmu->root_hpa; + + for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { + swap(root, mmu->prev_roots[i]); + + if (new_cr3 == root.cr3 && VALID_PAGE(root.hpa) && + page_header(root.hpa) != NULL && + new_role.word == page_header(root.hpa)->role.word) + break; + } + + mmu->root_hpa = root.hpa; + + return i < KVM_MMU_NUM_PREV_ROOTS; +} + +static bool fast_cr3_switch(struct kvm_vcpu *vcpu, gpa_t new_cr3, + union kvm_mmu_page_role new_role, + bool skip_tlb_flush) { - kvm_mmu_free_roots(vcpu); + struct kvm_mmu *mmu = &vcpu->arch.mmu; + + /* + * For now, limit the fast switch to 64-bit hosts+VMs in order to avoid + * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs + * later if necessary. + */ + if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL && + mmu->root_level >= PT64_ROOT_4LEVEL) { + if (mmu_check_root(vcpu, new_cr3 >> PAGE_SHIFT)) + return false; + + if (cached_root_available(vcpu, new_cr3, new_role)) { + /* + * It is possible that the cached previous root page is + * obsolete because of a change in the MMU + * generation number. However, that is accompanied by + * KVM_REQ_MMU_RELOAD, which will free the root that we + * have set here and allocate a new one. + */ + + kvm_make_request(KVM_REQ_LOAD_CR3, vcpu); + if (!skip_tlb_flush) { + kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); + kvm_x86_ops->tlb_flush(vcpu, true); + } + + /* + * The last MMIO access's GVA and GPA are cached in the + * VCPU. When switching to a new CR3, that GVA->GPA + * mapping may no longer be valid. So clear any cached + * MMIO info even when we don't need to sync the shadow + * page tables. + */ + vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); + + __clear_sp_write_flooding_count( + page_header(mmu->root_hpa)); + + return true; + } + } + + return false; } +static void __kvm_mmu_new_cr3(struct kvm_vcpu *vcpu, gpa_t new_cr3, + union kvm_mmu_page_role new_role, + bool skip_tlb_flush) +{ + if (!fast_cr3_switch(vcpu, new_cr3, new_role, skip_tlb_flush)) + kvm_mmu_free_roots(vcpu, KVM_MMU_ROOT_CURRENT); +} + +void kvm_mmu_new_cr3(struct kvm_vcpu *vcpu, gpa_t new_cr3, bool skip_tlb_flush) +{ + __kvm_mmu_new_cr3(vcpu, new_cr3, kvm_mmu_calc_root_page_role(vcpu), + skip_tlb_flush); +} +EXPORT_SYMBOL_GPL(kvm_mmu_new_cr3); + static unsigned long get_cr3(struct kvm_vcpu *vcpu) { return kvm_read_cr3(vcpu); @@ -4431,7 +4674,6 @@ static void paging64_init_context_common(struct kvm_vcpu *vcpu, context->invlpg = paging64_invlpg; context->update_pte = paging64_update_pte; context->shadow_root_level = level; - context->root_hpa = INVALID_PAGE; context->direct_map = false; } @@ -4461,7 +4703,6 @@ static void paging32_init_context(struct kvm_vcpu *vcpu, context->invlpg = paging32_invlpg; context->update_pte = paging32_update_pte; context->shadow_root_level = PT32E_ROOT_LEVEL; - context->root_hpa = INVALID_PAGE; context->direct_map = false; } @@ -4471,20 +4712,32 @@ static void paging32E_init_context(struct kvm_vcpu *vcpu, paging64_init_context_common(vcpu, context, PT32E_ROOT_LEVEL); } +static union kvm_mmu_page_role +kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu) +{ + union kvm_mmu_page_role role = {0}; + + role.guest_mode = is_guest_mode(vcpu); + role.smm = is_smm(vcpu); + role.ad_disabled = (shadow_accessed_mask == 0); + role.level = kvm_x86_ops->get_tdp_level(vcpu); + role.direct = true; + role.access = ACC_ALL; + + return role; +} + static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) { struct kvm_mmu *context = &vcpu->arch.mmu; - context->base_role.word = 0; - context->base_role.guest_mode = is_guest_mode(vcpu); - context->base_role.smm = is_smm(vcpu); - context->base_role.ad_disabled = (shadow_accessed_mask == 0); + context->base_role.word = mmu_base_role_mask.word & + kvm_calc_tdp_mmu_root_page_role(vcpu).word; context->page_fault = tdp_page_fault; context->sync_page = nonpaging_sync_page; context->invlpg = nonpaging_invlpg; context->update_pte = nonpaging_update_pte; context->shadow_root_level = kvm_x86_ops->get_tdp_level(vcpu); - context->root_hpa = INVALID_PAGE; context->direct_map = true; context->set_cr3 = kvm_x86_ops->set_tdp_cr3; context->get_cr3 = get_cr3; @@ -4519,13 +4772,36 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) reset_tdp_shadow_zero_bits_mask(vcpu, context); } -void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu) +static union kvm_mmu_page_role +kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu) { + union kvm_mmu_page_role role = {0}; bool smep = kvm_read_cr4_bits(vcpu, X86_CR4_SMEP); bool smap = kvm_read_cr4_bits(vcpu, X86_CR4_SMAP); - struct kvm_mmu *context = &vcpu->arch.mmu; - MMU_WARN_ON(VALID_PAGE(context->root_hpa)); + role.nxe = is_nx(vcpu); + role.cr4_pae = !!is_pae(vcpu); + role.cr0_wp = is_write_protection(vcpu); + role.smep_andnot_wp = smep && !is_write_protection(vcpu); + role.smap_andnot_wp = smap && !is_write_protection(vcpu); + role.guest_mode = is_guest_mode(vcpu); + role.smm = is_smm(vcpu); + role.direct = !is_paging(vcpu); + role.access = ACC_ALL; + + if (!is_long_mode(vcpu)) + role.level = PT32E_ROOT_LEVEL; + else if (is_la57_mode(vcpu)) + role.level = PT64_ROOT_5LEVEL; + else + role.level = PT64_ROOT_4LEVEL; + + return role; +} + +void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu) +{ + struct kvm_mmu *context = &vcpu->arch.mmu; if (!is_paging(vcpu)) nonpaging_init_context(vcpu, context); @@ -4536,26 +4812,34 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu) else paging32_init_context(vcpu, context); - context->base_role.nxe = is_nx(vcpu); - context->base_role.cr4_pae = !!is_pae(vcpu); - context->base_role.cr0_wp = is_write_protection(vcpu); - context->base_role.smep_andnot_wp - = smep && !is_write_protection(vcpu); - context->base_role.smap_andnot_wp - = smap && !is_write_protection(vcpu); - context->base_role.guest_mode = is_guest_mode(vcpu); - context->base_role.smm = is_smm(vcpu); + context->base_role.word = mmu_base_role_mask.word & + kvm_calc_shadow_mmu_root_page_role(vcpu).word; reset_shadow_zero_bits_mask(vcpu, context); } EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu); +static union kvm_mmu_page_role +kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty) +{ + union kvm_mmu_page_role role = vcpu->arch.mmu.base_role; + + role.level = PT64_ROOT_4LEVEL; + role.direct = false; + role.ad_disabled = !accessed_dirty; + role.guest_mode = true; + role.access = ACC_ALL; + + return role; +} + void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, - bool accessed_dirty) + bool accessed_dirty, gpa_t new_eptp) { struct kvm_mmu *context = &vcpu->arch.mmu; + union kvm_mmu_page_role root_page_role = + kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty); - MMU_WARN_ON(VALID_PAGE(context->root_hpa)); - + __kvm_mmu_new_cr3(vcpu, new_eptp, root_page_role, false); context->shadow_root_level = PT64_ROOT_4LEVEL; context->nx = true; @@ -4566,10 +4850,8 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, context->invlpg = ept_invlpg; context->update_pte = ept_update_pte; context->root_level = PT64_ROOT_4LEVEL; - context->root_hpa = INVALID_PAGE; context->direct_map = false; - context->base_role.ad_disabled = !accessed_dirty; - context->base_role.guest_mode = 1; + context->base_role.word = root_page_role.word & mmu_base_role_mask.word; update_permission_bitmask(vcpu, context, true); update_pkru_bitmask(vcpu, context, true); update_last_nonleaf_level(vcpu, context); @@ -4632,8 +4914,17 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu) update_last_nonleaf_level(vcpu, g_context); } -static void init_kvm_mmu(struct kvm_vcpu *vcpu) +void kvm_init_mmu(struct kvm_vcpu *vcpu, bool reset_roots) { + if (reset_roots) { + uint i; + + vcpu->arch.mmu.root_hpa = INVALID_PAGE; + + for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) + vcpu->arch.mmu.prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; + } + if (mmu_is_nested(vcpu)) init_kvm_nested_mmu(vcpu); else if (tdp_enabled) @@ -4641,11 +4932,21 @@ static void init_kvm_mmu(struct kvm_vcpu *vcpu) else init_kvm_softmmu(vcpu); } +EXPORT_SYMBOL_GPL(kvm_init_mmu); + +static union kvm_mmu_page_role +kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu) +{ + if (tdp_enabled) + return kvm_calc_tdp_mmu_root_page_role(vcpu); + else + return kvm_calc_shadow_mmu_root_page_role(vcpu); +} void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) { kvm_mmu_unload(vcpu); - init_kvm_mmu(vcpu); + kvm_init_mmu(vcpu, true); } EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); @@ -4660,8 +4961,8 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) kvm_mmu_sync_roots(vcpu); if (r) goto out; - /* set_cr3() should ensure TLB has been flushed */ - vcpu->arch.mmu.set_cr3(vcpu, vcpu->arch.mmu.root_hpa); + kvm_mmu_load_cr3(vcpu); + kvm_x86_ops->tlb_flush(vcpu, true); out: return r; } @@ -4669,7 +4970,7 @@ EXPORT_SYMBOL_GPL(kvm_mmu_load); void kvm_mmu_unload(struct kvm_vcpu *vcpu) { - kvm_mmu_free_roots(vcpu); + kvm_mmu_free_roots(vcpu, KVM_MMU_ROOTS_ALL); WARN_ON(VALID_PAGE(vcpu->arch.mmu.root_hpa)); } EXPORT_SYMBOL_GPL(kvm_mmu_unload); @@ -4822,16 +5123,6 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, u64 entry, gentry, *spte; int npte; bool remote_flush, local_flush; - union kvm_mmu_page_role mask = { }; - - mask.cr0_wp = 1; - mask.cr4_pae = 1; - mask.nxe = 1; - mask.smep_andnot_wp = 1; - mask.smap_andnot_wp = 1; - mask.smm = 1; - mask.guest_mode = 1; - mask.ad_disabled = 1; /* * If we don't have indirect shadow pages, it means no page is @@ -4875,7 +5166,7 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, mmu_page_zap_pte(vcpu->kvm, sp, spte); if (gentry && !((sp->role.word ^ vcpu->arch.mmu.base_role.word) - & mask.word) && rmap_can_add(vcpu)) + & mmu_base_role_mask.word) && rmap_can_add(vcpu)) mmu_pte_write_new_pte(vcpu, sp, spte, &gentry); if (need_remote_flush(entry, *spte)) remote_flush = true; @@ -5000,12 +5291,67 @@ EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) { - vcpu->arch.mmu.invlpg(vcpu, gva); - kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); + struct kvm_mmu *mmu = &vcpu->arch.mmu; + int i; + + /* INVLPG on a * non-canonical address is a NOP according to the SDM. */ + if (is_noncanonical_address(gva, vcpu)) + return; + + mmu->invlpg(vcpu, gva, mmu->root_hpa); + + /* + * INVLPG is required to invalidate any global mappings for the VA, + * irrespective of PCID. Since it would take us roughly similar amount + * of work to determine whether any of the prev_root mappings of the VA + * is marked global, or to just sync it blindly, so we might as well + * just always sync it. + * + * Mappings not reachable via the current cr3 or the prev_roots will be + * synced when switching to that cr3, so nothing needs to be done here + * for them. + */ + for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) + if (VALID_PAGE(mmu->prev_roots[i].hpa)) + mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); + + kvm_x86_ops->tlb_flush_gva(vcpu, gva); ++vcpu->stat.invlpg; } EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); +void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid) +{ + struct kvm_mmu *mmu = &vcpu->arch.mmu; + bool tlb_flush = false; + uint i; + + if (pcid == kvm_get_active_pcid(vcpu)) { + mmu->invlpg(vcpu, gva, mmu->root_hpa); + tlb_flush = true; + } + + for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { + if (VALID_PAGE(mmu->prev_roots[i].hpa) && + pcid == kvm_get_pcid(vcpu, mmu->prev_roots[i].cr3)) { + mmu->invlpg(vcpu, gva, mmu->prev_roots[i].hpa); + tlb_flush = true; + } + } + + if (tlb_flush) + kvm_x86_ops->tlb_flush_gva(vcpu, gva); + + ++vcpu->stat.invlpg; + + /* + * Mappings not reachable via the current cr3 or the prev_roots will be + * synced when switching to that cr3, so nothing needs to be done here + * for them. + */ +} +EXPORT_SYMBOL_GPL(kvm_mmu_invpcid_gva); + void kvm_enable_tdp(void) { tdp_enabled = true; @@ -5029,6 +5375,9 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu) struct page *page; int i; + if (tdp_enabled) + return 0; + /* * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64. * Therefore we need to allocate shadow page tables in the first @@ -5047,11 +5396,16 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu) int kvm_mmu_create(struct kvm_vcpu *vcpu) { + uint i; + vcpu->arch.walk_mmu = &vcpu->arch.mmu; vcpu->arch.mmu.root_hpa = INVALID_PAGE; vcpu->arch.mmu.translate_gpa = translate_gpa; vcpu->arch.nested_mmu.translate_gpa = translate_nested_gpa; + for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) + vcpu->arch.mmu.prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; + return alloc_mmu_pages(vcpu); } @@ -5059,7 +5413,7 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu) { MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu.root_hpa)); - init_kvm_mmu(vcpu); + kvm_init_mmu(vcpu, true); } static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, @@ -5499,7 +5853,7 @@ int kvm_mmu_module_init(void) { int ret = -ENOMEM; - kvm_mmu_clear_all_pte_masks(); + kvm_mmu_reset_all_pte_masks(); pte_list_desc_cache = kmem_cache_create("pte_list_desc", sizeof(struct pte_list_desc), |