diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 927 |
1 files changed, 490 insertions, 437 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 311f6da..fb8b376 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -7,7 +7,7 @@ * MMU support * * Copyright (C) 2006 Qumranet, Inc. - * Copyright 2010 Red Hat, Inc. and/or its affilates. + * Copyright 2010 Red Hat, Inc. and/or its affiliates. * * Authors: * Yaniv Kamay <yaniv@qumranet.com> @@ -49,15 +49,25 @@ */ bool tdp_enabled = false; -#undef MMU_DEBUG +enum { + AUDIT_PRE_PAGE_FAULT, + AUDIT_POST_PAGE_FAULT, + AUDIT_PRE_PTE_WRITE, + AUDIT_POST_PTE_WRITE, + AUDIT_PRE_SYNC, + AUDIT_POST_SYNC +}; -#undef AUDIT +char *audit_point_name[] = { + "pre page fault", + "post page fault", + "pre pte write", + "post pte write", + "pre sync", + "post sync" +}; -#ifdef AUDIT -static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg); -#else -static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {} -#endif +#undef MMU_DEBUG #ifdef MMU_DEBUG @@ -71,7 +81,7 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {} #endif -#if defined(MMU_DEBUG) || defined(AUDIT) +#ifdef MMU_DEBUG static int dbg = 0; module_param(dbg, bool, 0644); #endif @@ -89,6 +99,8 @@ module_param(oos_shadow, bool, 0644); } #endif +#define PTE_PREFETCH_NUM 8 + #define PT_FIRST_AVAIL_BITS_SHIFT 9 #define PT64_SECOND_AVAIL_BITS_SHIFT 52 @@ -178,6 +190,7 @@ typedef void (*mmu_parent_walk_fn) (struct kvm_mmu_page *sp, u64 *spte); static struct kmem_cache *pte_chain_cache; static struct kmem_cache *rmap_desc_cache; static struct kmem_cache *mmu_page_header_cache; +static struct percpu_counter kvm_total_used_mmu_pages; static u64 __read_mostly shadow_trap_nonpresent_pte; static u64 __read_mostly shadow_notrap_nonpresent_pte; @@ -299,18 +312,50 @@ static u64 __xchg_spte(u64 *sptep, u64 new_spte) #endif } +static bool spte_has_volatile_bits(u64 spte) +{ + if (!shadow_accessed_mask) + return false; + + if (!is_shadow_present_pte(spte)) + return false; + + if ((spte & shadow_accessed_mask) && + (!is_writable_pte(spte) || (spte & shadow_dirty_mask))) + return false; + + return true; +} + +static bool spte_is_bit_cleared(u64 old_spte, u64 new_spte, u64 bit_mask) +{ + return (old_spte & bit_mask) && !(new_spte & bit_mask); +} + static void update_spte(u64 *sptep, u64 new_spte) { - u64 old_spte; + u64 mask, old_spte = *sptep; - if (!shadow_accessed_mask || (new_spte & shadow_accessed_mask) || - !is_rmap_spte(*sptep)) + WARN_ON(!is_rmap_spte(new_spte)); + + new_spte |= old_spte & shadow_dirty_mask; + + mask = shadow_accessed_mask; + if (is_writable_pte(old_spte)) + mask |= shadow_dirty_mask; + + if (!spte_has_volatile_bits(old_spte) || (new_spte & mask) == mask) __set_spte(sptep, new_spte); - else { + else old_spte = __xchg_spte(sptep, new_spte); - if (old_spte & shadow_accessed_mask) - mark_page_accessed(pfn_to_page(spte_to_pfn(old_spte))); - } + + if (!shadow_accessed_mask) + return; + + if (spte_is_bit_cleared(old_spte, new_spte, shadow_accessed_mask)) + kvm_set_pfn_accessed(spte_to_pfn(old_spte)); + if (spte_is_bit_cleared(old_spte, new_spte, shadow_dirty_mask)) + kvm_set_pfn_dirty(spte_to_pfn(old_spte)); } static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, @@ -367,7 +412,7 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) if (r) goto out; r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache, - rmap_desc_cache, 4); + rmap_desc_cache, 4 + PTE_PREFETCH_NUM); if (r) goto out; r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8); @@ -591,6 +636,7 @@ static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) desc->sptes[0] = (u64 *)*rmapp; desc->sptes[1] = spte; *rmapp = (unsigned long)desc | 1; + ++count; } else { rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte); desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul); @@ -603,7 +649,7 @@ static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) desc = desc->more; } for (i = 0; desc->sptes[i]; ++i) - ; + ++count; desc->sptes[i] = spte; } return count; @@ -645,18 +691,17 @@ static void rmap_remove(struct kvm *kvm, u64 *spte) gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt); rmapp = gfn_to_rmap(kvm, gfn, sp->role.level); if (!*rmapp) { - printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte); + printk(KERN_ERR "rmap_remove: %p 0->BUG\n", spte); BUG(); } else if (!(*rmapp & 1)) { - rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte); + rmap_printk("rmap_remove: %p 1->0\n", spte); if ((u64 *)*rmapp != spte) { - printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n", - spte, *spte); + printk(KERN_ERR "rmap_remove: %p 1->BUG\n", spte); BUG(); } *rmapp = 0; } else { - rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte); + rmap_printk("rmap_remove: %p many->many\n", spte); desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul); prev_desc = NULL; while (desc) { @@ -670,35 +715,36 @@ static void rmap_remove(struct kvm *kvm, u64 *spte) prev_desc = desc; desc = desc->more; } - pr_err("rmap_remove: %p %llx many->many\n", spte, *spte); + pr_err("rmap_remove: %p many->many\n", spte); BUG(); } } -static void set_spte_track_bits(u64 *sptep, u64 new_spte) +static int set_spte_track_bits(u64 *sptep, u64 new_spte) { pfn_t pfn; u64 old_spte = *sptep; - if (!shadow_accessed_mask || !is_shadow_present_pte(old_spte) || - old_spte & shadow_accessed_mask) { + if (!spte_has_volatile_bits(old_spte)) __set_spte(sptep, new_spte); - } else + else old_spte = __xchg_spte(sptep, new_spte); if (!is_rmap_spte(old_spte)) - return; + return 0; + pfn = spte_to_pfn(old_spte); if (!shadow_accessed_mask || old_spte & shadow_accessed_mask) kvm_set_pfn_accessed(pfn); - if (is_writable_pte(old_spte)) + if (!shadow_dirty_mask || (old_spte & shadow_dirty_mask)) kvm_set_pfn_dirty(pfn); + return 1; } static void drop_spte(struct kvm *kvm, u64 *sptep, u64 new_spte) { - set_spte_track_bits(sptep, new_spte); - rmap_remove(kvm, sptep); + if (set_spte_track_bits(sptep, new_spte)) + rmap_remove(kvm, sptep); } static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte) @@ -746,13 +792,6 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn) } spte = rmap_next(kvm, rmapp, spte); } - if (write_protected) { - pfn_t pfn; - - spte = rmap_next(kvm, rmapp, NULL); - pfn = spte_to_pfn(*spte); - kvm_set_pfn_dirty(pfn); - } /* check for huge page mappings */ for (i = PT_DIRECTORY_LEVEL; @@ -947,6 +986,18 @@ static int is_empty_shadow_page(u64 *spt) } #endif +/* + * This value is the sum of all of the kvm instances's + * kvm->arch.n_used_mmu_pages values. We need a global, + * aggregate version in order to make the slab shrinker + * faster + */ +static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, int nr) +{ + kvm->arch.n_used_mmu_pages += nr; + percpu_counter_add(&kvm_total_used_mmu_pages, nr); +} + static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) { ASSERT(is_empty_shadow_page(sp->spt)); @@ -956,7 +1007,7 @@ static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) if (!sp->role.direct) __free_page(virt_to_page(sp->gfns)); kmem_cache_free(mmu_page_header_cache, sp); - ++kvm->arch.n_free_mmu_pages; + kvm_mod_used_mmu_pages(kvm, -1); } static unsigned kvm_page_table_hashfn(gfn_t gfn) @@ -979,7 +1030,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS); sp->multimapped = 0; sp->parent_pte = parent_pte; - --vcpu->kvm->arch.n_free_mmu_pages; + kvm_mod_used_mmu_pages(vcpu->kvm, +1); return sp; } @@ -1403,7 +1454,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, if (role.direct) role.cr4_pae = 0; role.access = access; - if (!tdp_enabled && vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) { + if (!vcpu->arch.mmu.direct_map + && vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) { quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level)); quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; role.quadrant = quadrant; @@ -1458,6 +1510,12 @@ static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, iterator->addr = addr; iterator->shadow_addr = vcpu->arch.mmu.root_hpa; iterator->level = vcpu->arch.mmu.shadow_root_level; + + if (iterator->level == PT64_ROOT_LEVEL && + vcpu->arch.mmu.root_level < PT64_ROOT_LEVEL && + !vcpu->arch.mmu.direct_map) + --iterator->level; + if (iterator->level == PT32E_ROOT_LEVEL) { iterator->shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3]; @@ -1665,41 +1723,31 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm, /* * Changing the number of mmu pages allocated to the vm - * Note: if kvm_nr_mmu_pages is too small, you will get dead lock + * Note: if goal_nr_mmu_pages is too small, you will get dead lock */ -void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages) +void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int goal_nr_mmu_pages) { - int used_pages; LIST_HEAD(invalid_list); - - used_pages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages; - used_pages = max(0, used_pages); - /* * If we set the number of mmu pages to be smaller be than the * number of actived pages , we must to free some mmu pages before we * change the value */ - if (used_pages > kvm_nr_mmu_pages) { - while (used_pages > kvm_nr_mmu_pages && + if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) { + while (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages && !list_empty(&kvm->arch.active_mmu_pages)) { struct kvm_mmu_page *page; page = container_of(kvm->arch.active_mmu_pages.prev, struct kvm_mmu_page, link); - used_pages -= kvm_mmu_prepare_zap_page(kvm, page, - &invalid_list); + kvm_mmu_prepare_zap_page(kvm, page, &invalid_list); + kvm_mmu_commit_zap_page(kvm, &invalid_list); } - kvm_mmu_commit_zap_page(kvm, &invalid_list); - kvm_nr_mmu_pages = used_pages; - kvm->arch.n_free_mmu_pages = 0; + goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; } - else - kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages - - kvm->arch.n_alloc_mmu_pages; - kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages; + kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages; } static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) @@ -1709,11 +1757,11 @@ static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) LIST_HEAD(invalid_list); int r; - pgprintk("%s: looking for gfn %lx\n", __func__, gfn); + pgprintk("%s: looking for gfn %llx\n", __func__, gfn); r = 0; for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) { - pgprintk("%s: gfn %lx role %x\n", __func__, gfn, + pgprintk("%s: gfn %llx role %x\n", __func__, gfn, sp->role.word); r = 1; kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); @@ -1729,7 +1777,7 @@ static void mmu_unshadow(struct kvm *kvm, gfn_t gfn) LIST_HEAD(invalid_list); for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) { - pgprintk("%s: zap %lx %x\n", + pgprintk("%s: zap %llx %x\n", __func__, gfn, sp->role.word); kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); } @@ -1925,7 +1973,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, * whether the guest actually used the pte (in order to detect * demand paging). */ - spte = shadow_base_present_pte | shadow_dirty_mask; + spte = shadow_base_present_pte; if (!speculative) spte |= shadow_accessed_mask; if (!dirty) @@ -1948,8 +1996,8 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, spte |= (u64)pfn << PAGE_SHIFT; if ((pte_access & ACC_WRITE_MASK) - || (!tdp_enabled && write_fault && !is_write_protection(vcpu) - && !user_fault)) { + || (!vcpu->arch.mmu.direct_map && write_fault + && !is_write_protection(vcpu) && !user_fault)) { if (level > PT_PAGE_TABLE_LEVEL && has_wrprotected_page(vcpu->kvm, gfn, level)) { @@ -1960,7 +2008,8 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, spte |= PT_WRITABLE_MASK; - if (!tdp_enabled && !(pte_access & ACC_WRITE_MASK)) + if (!vcpu->arch.mmu.direct_map + && !(pte_access & ACC_WRITE_MASK)) spte &= ~PT_USER_MASK; /* @@ -1973,7 +2022,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, goto set_pte; if (mmu_need_write_protect(vcpu, gfn, can_unsync)) { - pgprintk("%s: found shadow page for %lx, marking ro\n", + pgprintk("%s: found shadow page for %llx, marking ro\n", __func__, gfn); ret = 1; pte_access &= ~ACC_WRITE_MASK; @@ -1986,8 +2035,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, mark_page_dirty(vcpu->kvm, gfn); set_pte: - if (is_writable_pte(*sptep) && !is_writable_pte(spte)) - kvm_set_pfn_dirty(pfn); update_spte(sptep, spte); done: return ret; @@ -2004,7 +2051,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, int rmap_count; pgprintk("%s: spte %llx access %x write_fault %d" - " user_fault %d gfn %lx\n", + " user_fault %d gfn %llx\n", __func__, *sptep, pt_access, write_fault, user_fault, gfn); @@ -2023,7 +2070,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, __set_spte(sptep, shadow_trap_nonpresent_pte); kvm_flush_remote_tlbs(vcpu->kvm); } else if (pfn != spte_to_pfn(*sptep)) { - pgprintk("hfn old %lx new %lx\n", + pgprintk("hfn old %llx new %llx\n", spte_to_pfn(*sptep), pfn); drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte); kvm_flush_remote_tlbs(vcpu->kvm); @@ -2040,7 +2087,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, } pgprintk("%s: setting spte %llx\n", __func__, *sptep); - pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n", + pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n", is_large_pte(*sptep)? "2MB" : "4kB", *sptep & PT_PRESENT_MASK ?"RW":"R", gfn, *sptep, sptep); @@ -2064,6 +2111,105 @@ static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) { } +static struct kvm_memory_slot * +pte_prefetch_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn, bool no_dirty_log) +{ + struct kvm_memory_slot *slot; + + slot = gfn_to_memslot(vcpu->kvm, gfn); + if (!slot || slot->flags & KVM_MEMSLOT_INVALID || + (no_dirty_log && slot->dirty_bitmap)) + slot = NULL; + + return slot; +} + +static pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, + bool no_dirty_log) +{ + struct kvm_memory_slot *slot; + unsigned long hva; + + slot = pte_prefetch_gfn_to_memslot(vcpu, gfn, no_dirty_log); + if (!slot) { + get_page(bad_page); + return page_to_pfn(bad_page); + } + + hva = gfn_to_hva_memslot(slot, gfn); + + return hva_to_pfn_atomic(vcpu->kvm, hva); +} + +static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, + struct kvm_mmu_page *sp, + u64 *start, u64 *end) +{ + struct page *pages[PTE_PREFETCH_NUM]; + unsigned access = sp->role.access; + int i, ret; + gfn_t gfn; + + gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt); + if (!pte_prefetch_gfn_to_memslot(vcpu, gfn, access & ACC_WRITE_MASK)) + return -1; + + ret = gfn_to_page_many_atomic(vcpu->kvm, gfn, pages, end - start); + if (ret <= 0) + return -1; + + for (i = 0; i < ret; i++, gfn++, start++) + mmu_set_spte(vcpu, start, ACC_ALL, + access, 0, 0, 1, NULL, + sp->role.level, gfn, + page_to_pfn(pages[i]), true, true); + + return 0; +} + +static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, + struct kvm_mmu_page *sp, u64 *sptep) +{ + u64 *spte, *start = NULL; + int i; + + WARN_ON(!sp->role.direct); + + i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); + spte = sp->spt + i; + + for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { + if (*spte != shadow_trap_nonpresent_pte || spte == sptep) { + if (!start) + continue; + if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) + break; + start = NULL; + } else if (!start) + start = spte; + } +} + +static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) +{ + struct kvm_mmu_page *sp; + + /* + * Since it's no accessed bit on EPT, it's no way to + * distinguish between actually accessed translations + * and prefetched, so disable pte prefetch if EPT is + * enabled. + */ + if (!shadow_accessed_mask) + return; + + sp = page_header(__pa(sptep)); + if (sp->role.level > PT_PAGE_TABLE_LEVEL) + return; + + __direct_pte_prefetch(vcpu, sp, sptep); +} + static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, int level, gfn_t gfn, pfn_t pfn) { @@ -2077,6 +2223,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL, 0, write, 1, &pt_write, level, gfn, pfn, false, true); + direct_pte_prefetch(vcpu, iterator.sptep); ++vcpu->stat.pf_fixed; break; } @@ -2098,28 +2245,31 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, __set_spte(iterator.sptep, __pa(sp->spt) | PT_PRESENT_MASK | PT_WRITABLE_MASK - | shadow_user_mask | shadow_x_mask); + | shadow_user_mask | shadow_x_mask + | shadow_accessed_mask); } } return pt_write; } -static void kvm_send_hwpoison_signal(struct kvm *kvm, gfn_t gfn) +static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk) { - char buf[1]; - void __user *hva; - int r; + siginfo_t info; - /* Touch the page, so send SIGBUS */ - hva = (void __user *)gfn_to_hva(kvm, gfn); - r = copy_from_user(buf, hva, 1); + info.si_signo = SIGBUS; + info.si_errno = 0; + info.si_code = BUS_MCEERR_AR; + info.si_addr = (void __user *)address; + info.si_addr_lsb = PAGE_SHIFT; + + send_sig_info(SIGBUS, &info, tsk); } static int kvm_handle_bad_page(struct kvm *kvm, gfn_t gfn, pfn_t pfn) { kvm_release_pfn_clean(pfn); if (is_hwpoison_pfn(pfn)) { - kvm_send_hwpoison_signal(kvm, gfn); + kvm_send_hwpoison_signal(gfn_to_hva(kvm, gfn), current); return 0; } else if (is_fault_pfn(pfn)) return -EFAULT; @@ -2179,7 +2329,9 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) return; spin_lock(&vcpu->kvm->mmu_lock); - if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { + if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL && + (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL || + vcpu->arch.mmu.direct_map)) { hpa_t root = vcpu->arch.mmu.root_hpa; sp = page_header(root); @@ -2222,80 +2374,158 @@ static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) return ret; } -static int mmu_alloc_roots(struct kvm_vcpu *vcpu) +static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) { - int i; - gfn_t root_gfn; struct kvm_mmu_page *sp; - int direct = 0; - u64 pdptr; - - root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT; + unsigned i; if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { + spin_lock(&vcpu->kvm->mmu_lock); + kvm_mmu_free_some_pages(vcpu); + sp = kvm_mmu_get_page(vcpu, 0, 0, PT64_ROOT_LEVEL, + 1, ACC_ALL, NULL); + ++sp->root_count; + spin_unlock(&vcpu->kvm->mmu_lock); + vcpu->arch.mmu.root_hpa = __pa(sp->spt); + } else if (vcpu->arch.mmu.shadow_root_level == PT32E_ROOT_LEVEL) { + for (i = 0; i < 4; ++i) { + hpa_t root = vcpu->arch.mmu.pae_root[i]; + + ASSERT(!VALID_PAGE(root)); + spin_lock(&vcpu->kvm->mmu_lock); + kvm_mmu_free_some_pages(vcpu); + sp = kvm_mmu_get_page(vcpu, i << 30, i << 30, + PT32_ROOT_LEVEL, 1, ACC_ALL, + NULL); + root = __pa(sp->spt); + ++sp->root_count; + spin_unlock(&vcpu->kvm->mmu_lock); + vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK; + } + vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root); + } else + BUG(); + + return 0; +} + +static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) +{ + struct kvm_mmu_page *sp; + u64 pdptr, pm_mask; + gfn_t root_gfn; + int i; + + root_gfn = vcpu->arch.mmu.get_cr3(vcpu) >> PAGE_SHIFT; + + if (mmu_check_root(vcpu, root_gfn)) + return 1; + + /* + * Do we shadow a long mode page table? If so we need to + * write-protect the guests page table root. + */ + if (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL) { hpa_t root = vcpu->arch.mmu.root_hpa; ASSERT(!VALID_PAGE(root)); - if (mmu_check_root(vcpu, root_gfn)) - return 1; - if (tdp_enabled) { - direct = 1; - root_gfn = 0; - } + spin_lock(&vcpu->kvm->mmu_lock); kvm_mmu_free_some_pages(vcpu); - sp = kvm_mmu_get_page(vcpu, root_gfn, 0, - PT64_ROOT_LEVEL, direct, - ACC_ALL, NULL); + sp = kvm_mmu_get_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL, + 0, ACC_ALL, NULL); root = __pa(sp->spt); ++sp->root_count; spin_unlock(&vcpu->kvm->mmu_lock); vcpu->arch.mmu.root_hpa = root; return 0; } - direct = !is_paging(vcpu); + + /* + * We shadow a 32 bit page table. This may be a legacy 2-level + * or a PAE 3-level page table. In either case we need to be aware that + * the shadow page table may be a PAE or a long mode page table. + */ + pm_mask = PT_PRESENT_MASK; + if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) + pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; + for (i = 0; i < 4; ++i) { hpa_t root = vcpu->arch.mmu.pae_root[i]; ASSERT(!VALID_PAGE(root)); if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) { - pdptr = kvm_pdptr_read(vcpu, i); + pdptr = kvm_pdptr_read_mmu(vcpu, &vcpu->arch.mmu, i); if (!is_present_gpte(pdptr)) { vcpu->arch.mmu.pae_root[i] = 0; continue; } root_gfn = pdptr >> PAGE_SHIFT; - } else if (vcpu->arch.mmu.root_level == 0) - root_gfn = 0; - if (mmu_check_root(vcpu, root_gfn)) - return 1; - if (tdp_enabled) { - direct = 1; - root_gfn = i << 30; + if (mmu_check_root(vcpu, root_gfn)) + return 1; } spin_lock(&vcpu->kvm->mmu_lock); kvm_mmu_free_some_pages(vcpu); sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, - PT32_ROOT_LEVEL, direct, + PT32_ROOT_LEVEL, 0, ACC_ALL, NULL); root = __pa(sp->spt); ++sp->root_count; spin_unlock(&vcpu->kvm->mmu_lock); - vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK; + vcpu->arch.mmu.pae_root[i] = root | pm_mask; } vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root); + + /* + * If we shadow a 32 bit page table with a long mode page + * table we enter this path. + */ + if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { + if (vcpu->arch.mmu.lm_root == NULL) { + /* + * The additional page necessary for this is only + * allocated on demand. + */ + + u64 *lm_root; + + lm_root = (void*)get_zeroed_page(GFP_KERNEL); + if (lm_root == NULL) + return 1; + + lm_root[0] = __pa(vcpu->arch.mmu.pae_root) | pm_mask; + + vcpu->arch.mmu.lm_root = lm_root; + } + + vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.lm_root); + } + return 0; } +static int mmu_alloc_roots(struct kvm_vcpu *vcpu) +{ + if (vcpu->arch.mmu.direct_map) + return mmu_alloc_direct_roots(vcpu); + else + return mmu_alloc_shadow_roots(vcpu); +} + static void mmu_sync_roots(struct kvm_vcpu *vcpu) { int i; struct kvm_mmu_page *sp; + if (vcpu->arch.mmu.direct_map) + return; + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) return; - if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { + + trace_kvm_mmu_audit(vcpu, AUDIT_PRE_SYNC); + if (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL) { hpa_t root = vcpu->arch.mmu.root_hpa; sp = page_header(root); mmu_sync_children(vcpu, sp); @@ -2310,6 +2540,7 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu) mmu_sync_children(vcpu, sp); } } + trace_kvm_mmu_audit(vcpu, AUDIT_POST_SYNC); } void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) @@ -2327,6 +2558,14 @@ static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr, return vaddr; } +static gpa_t nonpaging_gva_to_gpa_nested(struct kvm_vcpu *vcpu, gva_t vaddr, + u32 access, u32 *error) +{ + if (error) + *error = 0; + return vcpu->arch.nested_mmu.translate_gpa(vcpu, vaddr, access); +} + static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, u32 error_code) { @@ -2393,10 +2632,9 @@ static void nonpaging_free(struct kvm_vcpu *vcpu) mmu_free_roots(vcpu); } -static int nonpaging_init_context(struct kvm_vcpu *vcpu) +static int nonpaging_init_context(struct kvm_vcpu *vcpu, + struct kvm_mmu *context) { - struct kvm_mmu *context = &vcpu->arch.mmu; - context->new_cr3 = nonpaging_new_cr3; context->page_fault = nonpaging_page_fault; context->gva_to_gpa = nonpaging_gva_to_gpa; @@ -2407,6 +2645,8 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu) context->root_level = 0; context->shadow_root_level = PT32E_ROOT_LEVEL; context->root_hpa = INVALID_PAGE; + context->direct_map = true; + context->nx = false; return 0; } @@ -2422,11 +2662,14 @@ static void paging_new_cr3(struct kvm_vcpu *vcpu) mmu_free_roots(vcpu); } -static void inject_page_fault(struct kvm_vcpu *vcpu, - u64 addr, - u32 err_code) +static unsigned long get_cr3(struct kvm_vcpu *vcpu) { - kvm_inject_page_fault(vcpu, addr, err_code); + return vcpu->arch.cr3; +} + +static void inject_page_fault(struct kvm_vcpu *vcpu) +{ + vcpu->arch.mmu.inject_page_fault(vcpu); } static void paging_free(struct kvm_vcpu *vcpu) @@ -2434,12 +2677,12 @@ static void paging_free(struct kvm_vcpu *vcpu) nonpaging_free(vcpu); } -static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level) +static bool is_rsvd_bits_set(struct kvm_mmu *mmu, u64 gpte, int level) { int bit7; bit7 = (gpte >> 7) & 1; - return (gpte & vcpu->arch.mmu.rsvd_bits_mask[bit7][level-1]) != 0; + return (gpte & mmu->rsvd_bits_mask[bit7][level-1]) != 0; } #define PTTYPE 64 @@ -2450,13 +2693,14 @@ static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level) #include "paging_tmpl.h" #undef PTTYPE -static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level) +static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, + struct kvm_mmu *context, + int level) { - struct kvm_mmu *context = &vcpu->arch.mmu; int maxphyaddr = cpuid_maxphyaddr(vcpu); u64 exb_bit_rsvd = 0; - if (!is_nx(vcpu)) + if (!context->nx) exb_bit_rsvd = rsvd_bits(63, 63); switch (level) { case PT32_ROOT_LEVEL: @@ -2511,9 +2755,13 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level) } } -static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level) +static int paging64_init_context_common(struct kvm_vcpu *vcpu, + struct kvm_mmu *context, + int level) { - struct kvm_mmu *context = &vcpu->arch.mmu; + context->nx = is_nx(vcpu); + + reset_rsvds_bits_mask(vcpu, context, level); ASSERT(is_pae(vcpu)); context->new_cr3 = paging_new_cr3; @@ -2526,20 +2774,23 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level) context->root_level = level; context->shadow_root_level = level; context->root_hpa = INVALID_PAGE; + context->direct_map = false; return 0; } -static int paging64_init_context(struct kvm_vcpu *vcpu) +static int paging64_init_context(struct kvm_vcpu *vcpu, + struct kvm_mmu *context) { - reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL); - return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL); + return paging64_init_context_common(vcpu, context, PT64_ROOT_LEVEL); } -static int paging32_init_context(struct kvm_vcpu *vcpu) +static int paging32_init_context(struct kvm_vcpu *vcpu, + struct kvm_mmu *context) { - struct kvm_mmu *context = &vcpu->arch.mmu; + context->nx = false; + + reset_rsvds_bits_mask(vcpu, context, PT32_ROOT_LEVEL); - reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL); context->new_cr3 = paging_new_cr3; context->page_fault = paging32_page_fault; context->gva_to_gpa = paging32_gva_to_gpa; @@ -2550,18 +2801,19 @@ static int paging32_init_context(struct kvm_vcpu *vcpu) context->root_level = PT32_ROOT_LEVEL; context->shadow_root_level = PT32E_ROOT_LEVEL; context->root_hpa = INVALID_PAGE; + context->direct_map = false; return 0; } -static int paging32E_init_context(struct kvm_vcpu *vcpu) +static int paging32E_init_context(struct kvm_vcpu *vcpu, + struct kvm_mmu *context) { - reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL); - return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL); + return paging64_init_context_common(vcpu, context, PT32E_ROOT_LEVEL); } static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) { - struct kvm_mmu *context = &vcpu->arch.mmu; + struct kvm_mmu *context = vcpu->arch.walk_mmu; context->new_cr3 = nonpaging_new_cr3; context->page_fault = tdp_page_fault; @@ -2571,20 +2823,29 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) context->invlpg = nonpaging_invlpg; context->shadow_root_level = kvm_x86_ops->get_tdp_level(); context->root_hpa = INVALID_PAGE; + context->direct_map = true; + context->set_cr3 = kvm_x86_ops->set_tdp_cr3; + context->get_cr3 = get_cr3; + context->inject_page_fault = kvm_inject_page_fault; + context->nx = is_nx(vcpu); if (!is_paging(vcpu)) { + context->nx = false; context->gva_to_gpa = nonpaging_gva_to_gpa; context->root_level = 0; } else if (is_long_mode(vcpu)) { - reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL); + context->nx = is_nx(vcpu); + reset_rsvds_bits_mask(vcpu, context, PT64_ROOT_LEVEL); context->gva_to_gpa = paging64_gva_to_gpa; context->root_level = PT64_ROOT_LEVEL; } else if (is_pae(vcpu)) { - reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL); + context->nx = is_nx(vcpu); + reset_rsvds_bits_mask(vcpu, context, PT32E_ROOT_LEVEL); context->gva_to_gpa = paging64_gva_to_gpa; context->root_level = PT32E_ROOT_LEVEL; } else { - reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL); + context->nx = false; + reset_rsvds_bits_mask(vcpu, context, PT32_ROOT_LEVEL); context->gva_to_gpa = paging32_gva_to_gpa; context->root_level = PT32_ROOT_LEVEL; } @@ -2592,33 +2853,83 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) return 0; } -static int init_kvm_softmmu(struct kvm_vcpu *vcpu) +int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context) { int r; - ASSERT(vcpu); ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); if (!is_paging(vcpu)) - r = nonpaging_init_context(vcpu); + r = nonpaging_init_context(vcpu, context); else if (is_long_mode(vcpu)) - r = paging64_init_context(vcpu); + r = paging64_init_context(vcpu, context); else if (is_pae(vcpu)) - r = paging32E_init_context(vcpu); + r = paging32E_init_context(vcpu, context); else - r = paging32_init_context(vcpu); + r = paging32_init_context(vcpu, context); vcpu->arch.mmu.base_role.cr4_pae = !!is_pae(vcpu); - vcpu->arch.mmu.base_role.cr0_wp = is_write_protection(vcpu); + vcpu->arch.mmu.base_role.cr0_wp = is_write_protection(vcpu); return r; } +EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu); + +static int init_kvm_softmmu(struct kvm_vcpu *vcpu) +{ + int r = kvm_init_shadow_mmu(vcpu, vcpu->arch.walk_mmu); + + vcpu->arch.walk_mmu->set_cr3 = kvm_x86_ops->set_cr3; + vcpu->arch.walk_mmu->get_cr3 = get_cr3; + vcpu->arch.walk_mmu->inject_page_fault = kvm_inject_page_fault; + + return r; +} + +static int init_kvm_nested_mmu(struct kvm_vcpu *vcpu) +{ + struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; + + g_context->get_cr3 = get_cr3; + g_context->inject_page_fault = kvm_inject_page_fault; + + /* + * Note that arch.mmu.gva_to_gpa translates l2_gva to l1_gpa. The + * translation of l2_gpa to l1_gpa addresses is done using the + * arch.nested_mmu.gva_to_gpa function. Basically the gva_to_gpa + * functions between mmu and nested_mmu are swapped. + */ + if (!is_paging(vcpu)) { + g_context->nx = false; + g_context->root_level = 0; + g_context->gva_to_gpa = nonpaging_gva_to_gpa_nested; + } else if (is_long_mode(vcpu)) { + g_context->nx = is_nx(vcpu); + reset_rsvds_bits_mask(vcpu, g_context, PT64_ROOT_LEVEL); + g_context->root_level = PT64_ROOT_LEVEL; + g_context->gva_to_gpa = paging64_gva_to_gpa_nested; + } else if (is_pae(vcpu)) { + g_context->nx = is_nx(vcpu); + reset_rsvds_bits_mask(vcpu, g_context, PT32E_ROOT_LEVEL); + g_context->root_level = PT32E_ROOT_LEVEL; + g_context->gva_to_gpa = paging64_gva_to_gpa_nested; + } else { + g_context->nx = false; + reset_rsvds_bits_mask(vcpu, g_context, PT32_ROOT_LEVEL); + g_context->root_level = PT32_ROOT_LEVEL; + g_context->gva_to_gpa = paging32_gva_to_gpa_nested; + } + + return 0; +} static int init_kvm_mmu(struct kvm_vcpu *vcpu) { vcpu->arch.update_pte.pfn = bad_pfn; - if (tdp_enabled) + if (mmu_is_nested(vcpu)) + return init_kvm_nested_mmu(vcpu); + else if (tdp_enabled) return init_kvm_tdp_mmu(vcpu); else return init_kvm_softmmu(vcpu); @@ -2653,7 +2964,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) if (r) goto out; /* set_cr3() should ensure TLB has been flushed */ - kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa); + vcpu->arch.mmu.set_cr3(vcpu, vcpu->arch.mmu.root_hpa); out: return r; } @@ -2663,6 +2974,7 @@ void kvm_mmu_unload(struct kvm_vcpu *vcpu) { mmu_free_roots(vcpu); } +EXPORT_SYMBOL_GPL(kvm_mmu_unload); static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, @@ -2695,7 +3007,7 @@ static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu, return; } - if (is_rsvd_bits_set(vcpu, *(u64 *)new, PT_PAGE_TABLE_LEVEL)) + if (is_rsvd_bits_set(&vcpu->arch.mmu, *(u64 *)new, PT_PAGE_TABLE_LEVEL)) return; ++vcpu->kvm->stat.mmu_pte_updated; @@ -2837,7 +3149,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, kvm_mmu_access_page(vcpu, gfn); kvm_mmu_free_some_pages(vcpu); ++vcpu->kvm->stat.mmu_pte_write; - kvm_mmu_audit(vcpu, "pre pte write"); + trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PTE_WRITE); if (guest_initiated) { if (gfn == vcpu->arch.last_pt_write_gfn && !last_updated_pte_accessed(vcpu)) { @@ -2910,7 +3222,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, } mmu_pte_write_flush_tlb(vcpu, zap_page, remote_flush, local_flush); kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); - kvm_mmu_audit(vcpu, "post pte write"); + trace_kvm_mmu_audit(vcpu, AUDIT_POST_PTE_WRITE); spin_unlock(&vcpu->kvm->mmu_lock); if (!is_error_pfn(vcpu->arch.update_pte.pfn)) { kvm_release_pfn_clean(vcpu->arch.update_pte.pfn); @@ -2923,7 +3235,7 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) gpa_t gpa; int r; - if (tdp_enabled) + if (vcpu->arch.mmu.direct_map) return 0; gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); @@ -2937,21 +3249,18 @@ EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt); void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) { - int free_pages; LIST_HEAD(invalid_list); - free_pages = vcpu->kvm->arch.n_free_mmu_pages; - while (free_pages < KVM_REFILL_PAGES && + while (kvm_mmu_available_pages(vcpu->kvm) < KVM_REFILL_PAGES && !list_empty(&vcpu->kvm->arch.active_mmu_pages)) { struct kvm_mmu_page *sp; sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev, struct kvm_mmu_page, link); - free_pages += kvm_mmu_prepare_zap_page(vcpu->kvm, sp, - &invalid_list); + kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); + kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); ++vcpu->kvm->stat.mmu_recycled; } - kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); } int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code) @@ -3013,6 +3322,8 @@ EXPORT_SYMBOL_GPL(kvm_disable_tdp); static void free_mmu_pages(struct kvm_vcpu *vcpu) { free_page((unsigned long)vcpu->arch.mmu.pae_root); + if (vcpu->arch.mmu.lm_root != NULL) + free_page((unsigned long)vcpu->arch.mmu.lm_root); } static int alloc_mmu_pages(struct kvm_vcpu *vcpu) @@ -3054,15 +3365,6 @@ int kvm_mmu_setup(struct kvm_vcpu *vcpu) return init_kvm_mmu(vcpu); } -void kvm_mmu_destroy(struct kvm_vcpu *vcpu) -{ - ASSERT(vcpu); - - destroy_kvm_mmu(vcpu); - free_mmu_pages(vcpu); - mmu_free_memory_caches(vcpu); -} - void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) { struct kvm_mmu_page *sp; @@ -3112,23 +3414,22 @@ static int mmu_shrink(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask) { struct kvm *kvm; struct kvm *kvm_freed = NULL; - int cache_count = 0; + + if (nr_to_scan == 0) + goto out; spin_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { - int npages, idx, freed_pages; + int idx, freed_pages; LIST_HEAD(invalid_list); idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); - npages = kvm->arch.n_alloc_mmu_pages - - kvm->arch.n_free_mmu_pages; - cache_count += npages; - if (!kvm_freed && nr_to_scan > 0 && npages > 0) { + if (!kvm_freed && nr_to_scan > 0 && + kvm->arch.n_used_mmu_pages > 0) { freed_pages = kvm_mmu_remove_some_alloc_mmu_pages(kvm, &invalid_list); - cache_count -= freed_pages; kvm_freed = kvm; } nr_to_scan--; @@ -3142,7 +3443,8 @@ static int mmu_shrink(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask) spin_unlock(&kvm_lock); - return cache_count; +out: + return percpu_counter_read_positive(&kvm_total_used_mmu_pages); } static struct shrinker mmu_shrinker = { @@ -3163,6 +3465,7 @@ static void mmu_destroy_caches(void) void kvm_mmu_module_exit(void) { mmu_destroy_caches(); + percpu_counter_destroy(&kvm_total_used_mmu_pages); unregister_shrinker(&mmu_shrinker); } @@ -3185,6 +3488,9 @@ int kvm_mmu_module_init(void) if (!mmu_page_header_cache) goto nomem; + if (percpu_counter_init(&kvm_total_used_mmu_pages, 0)) + goto nomem; + register_shrinker(&mmu_shrinker); return 0; @@ -3355,271 +3661,18 @@ int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]) } EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy); -#ifdef AUDIT - -static const char *audit_msg; - -static gva_t canonicalize(gva_t gva) -{ -#ifdef CONFIG_X86_64 - gva = (long long)(gva << 16) >> 16; +#ifdef CONFIG_KVM_MMU_AUDIT +#include "mmu_audit.c" +#else +static void mmu_audit_disable(void) { } #endif - return gva; -} - - -typedef void (*inspect_spte_fn) (struct kvm *kvm, u64 *sptep); - -static void __mmu_spte_walk(struct kvm *kvm, struct kvm_mmu_page *sp, - inspect_spte_fn fn) -{ - int i; - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - u64 ent = sp->spt[i]; - - if (is_shadow_present_pte(ent)) { - if (!is_last_spte(ent, sp->role.level)) { - struct kvm_mmu_page *child; - child = page_header(ent & PT64_BASE_ADDR_MASK); - __mmu_spte_walk(kvm, child, fn); - } else - fn(kvm, &sp->spt[i]); - } - } -} - -static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn) -{ - int i; - struct kvm_mmu_page *sp; - - if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) - return; - if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { - hpa_t root = vcpu->arch.mmu.root_hpa; - sp = page_header(root); - __mmu_spte_walk(vcpu->kvm, sp, fn); - return; - } - for (i = 0; i < 4; ++i) { - hpa_t root = vcpu->arch.mmu.pae_root[i]; - - if (root && VALID_PAGE(root)) { - root &= PT64_BASE_ADDR_MASK; - sp = page_header(root); - __mmu_spte_walk(vcpu->kvm, sp, fn); - } - } - return; -} - -static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte, - gva_t va, int level) -{ - u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK); - int i; - gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1)); - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) { - u64 ent = pt[i]; - - if (ent == shadow_trap_nonpresent_pte) - continue; - - va = canonicalize(va); - if (is_shadow_present_pte(ent) && !is_last_spte(ent, level)) - audit_mappings_page(vcpu, ent, va, level - 1); - else { - gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, va, NULL); - gfn_t gfn = gpa >> PAGE_SHIFT; - pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn); - hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT; - - if (is_error_pfn(pfn)) { - kvm_release_pfn_clean(pfn); - continue; - } - - if (is_shadow_present_pte(ent) - && (ent & PT64_BASE_ADDR_MASK) != hpa) - printk(KERN_ERR "xx audit error: (%s) levels %d" - " gva %lx gpa %llx hpa %llx ent %llx %d\n", - audit_msg, vcpu->arch.mmu.root_level, - va, gpa, hpa, ent, - is_shadow_present_pte(ent)); - else if (ent == shadow_notrap_nonpresent_pte - && !is_error_hpa(hpa)) - printk(KERN_ERR "audit: (%s) notrap shadow," - " valid guest gva %lx\n", audit_msg, va); - kvm_release_pfn_clean(pfn); - - } - } -} - -static void audit_mappings(struct kvm_vcpu *vcpu) -{ - unsigned i; - - if (vcpu->arch.mmu.root_level == 4) - audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4); - else - for (i = 0; i < 4; ++i) - if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK) - audit_mappings_page(vcpu, - vcpu->arch.mmu.pae_root[i], - i << 30, - 2); -} - -static int count_rmaps(struct kvm_vcpu *vcpu) -{ - struct kvm *kvm = vcpu->kvm; - struct kvm_memslots *slots; - int nmaps = 0; - int i, j, k, idx; - - idx = srcu_read_lock(&kvm->srcu); - slots = kvm_memslots(kvm); - for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { - struct kvm_memory_slot *m = &slots->memslots[i]; - struct kvm_rmap_desc *d; - - for (j = 0; j < m->npages; ++j) { - unsigned long *rmapp = &m->rmap[j]; - - if (!*rmapp) - continue; - if (!(*rmapp & 1)) { - ++nmaps; - continue; - } - d = (struct kvm_rmap_desc *)(*rmapp & ~1ul); - while (d) { - for (k = 0; k < RMAP_EXT; ++k) - if (d->sptes[k]) - ++nmaps; - else - break; - d = d->more; - } - } - } - srcu_read_unlock(&kvm->srcu, idx); - return nmaps; -} - -void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep) -{ - unsigned long *rmapp; - struct kvm_mmu_page *rev_sp; - gfn_t gfn; - - if (is_writable_pte(*sptep)) { - rev_sp = page_header(__pa(sptep)); - gfn = kvm_mmu_page_get_gfn(rev_sp, sptep - rev_sp->spt); - - if (!gfn_to_memslot(kvm, gfn)) { - if (!printk_ratelimit()) - return; - printk(KERN_ERR "%s: no memslot for gfn %ld\n", - audit_msg, gfn); - printk(KERN_ERR "%s: index %ld of sp (gfn=%lx)\n", - audit_msg, (long int)(sptep - rev_sp->spt), - rev_sp->gfn); - dump_stack(); - return; - } - - rmapp = gfn_to_rmap(kvm, gfn, rev_sp->role.level); - if (!*rmapp) { - if (!printk_ratelimit()) - return; - printk(KERN_ERR "%s: no rmap for writable spte %llx\n", - audit_msg, *sptep); - dump_stack(); - } - } - -} - -void audit_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu) -{ - mmu_spte_walk(vcpu, inspect_spte_has_rmap); -} - -static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu) -{ - struct kvm_mmu_page *sp; - int i; - - list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) { - u64 *pt = sp->spt; - - if (sp->role.level != PT_PAGE_TABLE_LEVEL) - continue; - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - u64 ent = pt[i]; - - if (!(ent & PT_PRESENT_MASK)) - continue; - if (!is_writable_pte(ent)) - continue; - inspect_spte_has_rmap(vcpu->kvm, &pt[i]); - } - } - return; -} - -static void audit_rmap(struct kvm_vcpu *vcpu) -{ - check_writable_mappings_rmap(vcpu); - count_rmaps(vcpu); -} - -static void audit_write_protection(struct kvm_vcpu *vcpu) -{ - struct kvm_mmu_page *sp; - struct kvm_memory_slot *slot; - unsigned long *rmapp; - u64 *spte; - gfn_t gfn; - - list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) { - if (sp->role.direct) - continue; - if (sp->unsync) - continue; - - slot = gfn_to_memslot(vcpu->kvm, sp->gfn); - rmapp = &slot->rmap[gfn - slot->base_gfn]; - - spte = rmap_next(vcpu->kvm, rmapp, NULL); - while (spte) { - if (is_writable_pte(*spte)) - printk(KERN_ERR "%s: (%s) shadow page has " - "writable mappings: gfn %lx role %x\n", - __func__, audit_msg, sp->gfn, - sp->role.word); - spte = rmap_next(vcpu->kvm, rmapp, spte); - } - } -} -static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) +void kvm_mmu_destroy(struct kvm_vcpu *vcpu) { - int olddbg = dbg; + ASSERT(vcpu); - dbg = 0; - audit_msg = msg; - audit_rmap(vcpu); - audit_write_protection(vcpu); - if (strcmp("pre pte write", audit_msg) != 0) - audit_mappings(vcpu); - audit_writable_sptes_have_rmaps(vcpu); - dbg = olddbg; + destroy_kvm_mmu(vcpu); + free_mmu_pages(vcpu); + mmu_free_memory_caches(vcpu); + mmu_audit_disable(); } - -#endif |
