diff options
Diffstat (limited to 'drivers/kvm/mmu.c')
| -rw-r--r-- | drivers/kvm/mmu.c | 1806 |
1 files changed, 0 insertions, 1806 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c deleted file mode 100644 index c26d83f86a3a..000000000000 --- a/drivers/kvm/mmu.c +++ /dev/null @@ -1,1806 +0,0 @@ -/* - * Kernel-based Virtual Machine driver for Linux - * - * This module enables machines with Intel VT-x extensions to run virtual - * machines without emulation or binary translation. - * - * MMU support - * - * Copyright (C) 2006 Qumranet, Inc. - * - * Authors: - * Yaniv Kamay <yaniv@qumranet.com> - * Avi Kivity <avi@qumranet.com> - * - * This work is licensed under the terms of the GNU GPL, version 2. See - * the COPYING file in the top-level directory. - * - */ - -#include "vmx.h" -#include "kvm.h" -#include "x86.h" -#include "mmu.h" - -#include <linux/types.h> -#include <linux/string.h> -#include <linux/mm.h> -#include <linux/highmem.h> -#include <linux/module.h> -#include <linux/swap.h> - -#include <asm/page.h> -#include <asm/cmpxchg.h> -#include <asm/io.h> - -#undef MMU_DEBUG - -#undef AUDIT - -#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 - -#ifdef MMU_DEBUG - -#define pgprintk(x...) do { if (dbg) printk(x); } while (0) -#define rmap_printk(x...) do { if (dbg) printk(x); } while (0) - -#else - -#define pgprintk(x...) do { } while (0) -#define rmap_printk(x...) do { } while (0) - -#endif - -#if defined(MMU_DEBUG) || defined(AUDIT) -static int dbg = 1; -#endif - -#ifndef MMU_DEBUG -#define ASSERT(x) do { } while (0) -#else -#define ASSERT(x) \ - if (!(x)) { \ - printk(KERN_WARNING "assertion failed %s:%d: %s\n", \ - __FILE__, __LINE__, #x); \ - } -#endif - -#define PT64_PT_BITS 9 -#define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS) -#define PT32_PT_BITS 10 -#define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS) - -#define PT_WRITABLE_SHIFT 1 - -#define PT_PRESENT_MASK (1ULL << 0) -#define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT) -#define PT_USER_MASK (1ULL << 2) -#define PT_PWT_MASK (1ULL << 3) -#define PT_PCD_MASK (1ULL << 4) -#define PT_ACCESSED_MASK (1ULL << 5) -#define PT_DIRTY_MASK (1ULL << 6) -#define PT_PAGE_SIZE_MASK (1ULL << 7) -#define PT_PAT_MASK (1ULL << 7) -#define PT_GLOBAL_MASK (1ULL << 8) -#define PT64_NX_SHIFT 63 -#define PT64_NX_MASK (1ULL << PT64_NX_SHIFT) - -#define PT_PAT_SHIFT 7 -#define PT_DIR_PAT_SHIFT 12 -#define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT) - -#define PT32_DIR_PSE36_SIZE 4 -#define PT32_DIR_PSE36_SHIFT 13 -#define PT32_DIR_PSE36_MASK \ - (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT) - - -#define PT_FIRST_AVAIL_BITS_SHIFT 9 -#define PT64_SECOND_AVAIL_BITS_SHIFT 52 - -#define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) - -#define VALID_PAGE(x) ((x) != INVALID_PAGE) - -#define PT64_LEVEL_BITS 9 - -#define PT64_LEVEL_SHIFT(level) \ - (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS) - -#define PT64_LEVEL_MASK(level) \ - (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level)) - -#define PT64_INDEX(address, level)\ - (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1)) - - -#define PT32_LEVEL_BITS 10 - -#define PT32_LEVEL_SHIFT(level) \ - (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS) - -#define PT32_LEVEL_MASK(level) \ - (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level)) - -#define PT32_INDEX(address, level)\ - (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1)) - - -#define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1)) -#define PT64_DIR_BASE_ADDR_MASK \ - (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1)) - -#define PT32_BASE_ADDR_MASK PAGE_MASK -#define PT32_DIR_BASE_ADDR_MASK \ - (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1)) - -#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \ - | PT64_NX_MASK) - -#define PFERR_PRESENT_MASK (1U << 0) -#define PFERR_WRITE_MASK (1U << 1) -#define PFERR_USER_MASK (1U << 2) -#define PFERR_FETCH_MASK (1U << 4) - -#define PT64_ROOT_LEVEL 4 -#define PT32_ROOT_LEVEL 2 -#define PT32E_ROOT_LEVEL 3 - -#define PT_DIRECTORY_LEVEL 2 -#define PT_PAGE_TABLE_LEVEL 1 - -#define RMAP_EXT 4 - -#define ACC_EXEC_MASK 1 -#define ACC_WRITE_MASK PT_WRITABLE_MASK -#define ACC_USER_MASK PT_USER_MASK -#define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK) - -struct kvm_rmap_desc { - u64 *shadow_ptes[RMAP_EXT]; - struct kvm_rmap_desc *more; -}; - -static struct kmem_cache *pte_chain_cache; -static struct kmem_cache *rmap_desc_cache; -static struct kmem_cache *mmu_page_header_cache; - -static u64 __read_mostly shadow_trap_nonpresent_pte; -static u64 __read_mostly shadow_notrap_nonpresent_pte; - -void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte) -{ - shadow_trap_nonpresent_pte = trap_pte; - shadow_notrap_nonpresent_pte = notrap_pte; -} -EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes); - -static int is_write_protection(struct kvm_vcpu *vcpu) -{ - return vcpu->arch.cr0 & X86_CR0_WP; -} - -static int is_cpuid_PSE36(void) -{ - return 1; -} - -static int is_nx(struct kvm_vcpu *vcpu) -{ - return vcpu->arch.shadow_efer & EFER_NX; -} - -static int is_present_pte(unsigned long pte) -{ - return pte & PT_PRESENT_MASK; -} - -static int is_shadow_present_pte(u64 pte) -{ - pte &= ~PT_SHADOW_IO_MARK; - return pte != shadow_trap_nonpresent_pte - && pte != shadow_notrap_nonpresent_pte; -} - -static int is_writeble_pte(unsigned long pte) -{ - return pte & PT_WRITABLE_MASK; -} - -static int is_dirty_pte(unsigned long pte) -{ - return pte & PT_DIRTY_MASK; -} - -static int is_io_pte(unsigned long pte) -{ - return pte & PT_SHADOW_IO_MARK; -} - -static int is_rmap_pte(u64 pte) -{ - return pte != shadow_trap_nonpresent_pte - && pte != shadow_notrap_nonpresent_pte; -} - -static gfn_t pse36_gfn_delta(u32 gpte) -{ - int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT; - - return (gpte & PT32_DIR_PSE36_MASK) << shift; -} - -static void set_shadow_pte(u64 *sptep, u64 spte) -{ -#ifdef CONFIG_X86_64 - set_64bit((unsigned long *)sptep, spte); -#else - set_64bit((unsigned long long *)sptep, spte); -#endif -} - -static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, - struct kmem_cache *base_cache, int min) -{ - void *obj; - - if (cache->nobjs >= min) - return 0; - while (cache->nobjs < ARRAY_SIZE(cache->objects)) { - obj = kmem_cache_zalloc(base_cache, GFP_KERNEL); - if (!obj) - return -ENOMEM; - cache->objects[cache->nobjs++] = obj; - } - return 0; -} - -static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) -{ - while (mc->nobjs) - kfree(mc->objects[--mc->nobjs]); -} - -static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache, - int min) -{ - struct page *page; - - if (cache->nobjs >= min) - return 0; - while (cache->nobjs < ARRAY_SIZE(cache->objects)) { - page = alloc_page(GFP_KERNEL); - if (!page) - return -ENOMEM; - set_page_private(page, 0); - cache->objects[cache->nobjs++] = page_address(page); - } - return 0; -} - -static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc) -{ - while (mc->nobjs) - free_page((unsigned long)mc->objects[--mc->nobjs]); -} - -static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) -{ - int r; - - kvm_mmu_free_some_pages(vcpu); - r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache, - pte_chain_cache, 4); - if (r) - goto out; - r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache, - rmap_desc_cache, 1); - if (r) - goto out; - r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8); - if (r) - goto out; - r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, - mmu_page_header_cache, 4); -out: - return r; -} - -static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) -{ - mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache); - mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache); - mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache); - mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); -} - -static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc, - size_t size) -{ - void *p; - - BUG_ON(!mc->nobjs); - p = mc->objects[--mc->nobjs]; - memset(p, 0, size); - return p; -} - -static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu) -{ - return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache, - sizeof(struct kvm_pte_chain)); -} - -static void mmu_free_pte_chain(struct kvm_pte_chain *pc) -{ - kfree(pc); -} - -static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu) -{ - return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache, - sizeof(struct kvm_rmap_desc)); -} - -static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd) -{ - kfree(rd); -} - -/* - * Take gfn and return the reverse mapping to it. - * Note: gfn must be unaliased before this function get called - */ - -static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn) -{ - struct kvm_memory_slot *slot; - - slot = gfn_to_memslot(kvm, gfn); - return &slot->rmap[gfn - slot->base_gfn]; -} - -/* - * Reverse mapping data structures: - * - * If rmapp bit zero is zero, then rmapp point to the shadw page table entry - * that points to page_address(page). - * - * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc - * containing more mappings. - */ -static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) -{ - struct kvm_mmu_page *sp; - struct kvm_rmap_desc *desc; - unsigned long *rmapp; - int i; - - if (!is_rmap_pte(*spte)) - return; - gfn = unalias_gfn(vcpu->kvm, gfn); - sp = page_header(__pa(spte)); - sp->gfns[spte - sp->spt] = gfn; - rmapp = gfn_to_rmap(vcpu->kvm, gfn); - if (!*rmapp) { - rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte); - *rmapp = (unsigned long)spte; - } else if (!(*rmapp & 1)) { - rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte); - desc = mmu_alloc_rmap_desc(vcpu); - desc->shadow_ptes[0] = (u64 *)*rmapp; - desc->shadow_ptes[1] = spte; - *rmapp = (unsigned long)desc | 1; - } else { - rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte); - desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul); - while (desc->shadow_ptes[RMAP_EXT-1] && desc->more) - desc = desc->more; - if (desc->shadow_ptes[RMAP_EXT-1]) { - desc->more = mmu_alloc_rmap_desc(vcpu); - desc = desc->more; - } - for (i = 0; desc->shadow_ptes[i]; ++i) - ; - desc->shadow_ptes[i] = spte; - } -} - -static void rmap_desc_remove_entry(unsigned long *rmapp, - struct kvm_rmap_desc *desc, - int i, - struct kvm_rmap_desc *prev_desc) -{ - int j; - - for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j) - ; - desc->shadow_ptes[i] = desc->shadow_ptes[j]; - desc->shadow_ptes[j] = NULL; - if (j != 0) - return; - if (!prev_desc && !desc->more) - *rmapp = (unsigned long)desc->shadow_ptes[0]; - else - if (prev_desc) - prev_desc->more = desc->more; - else - *rmapp = (unsigned long)desc->more | 1; - mmu_free_rmap_desc(desc); -} - -static void rmap_remove(struct kvm *kvm, u64 *spte) -{ - struct kvm_rmap_desc *desc; - struct kvm_rmap_desc *prev_desc; - struct kvm_mmu_page *sp; - struct page *page; - unsigned long *rmapp; - int i; - - if (!is_rmap_pte(*spte)) - return; - sp = page_header(__pa(spte)); - page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT); - mark_page_accessed(page); - if (is_writeble_pte(*spte)) - kvm_release_page_dirty(page); - else - kvm_release_page_clean(page); - rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt]); - if (!*rmapp) { - printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte); - BUG(); - } else if (!(*rmapp & 1)) { - rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte); - if ((u64 *)*rmapp != spte) { - printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n", - spte, *spte); - BUG(); - } - *rmapp = 0; - } else { - rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte); - desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul); - prev_desc = NULL; - while (desc) { - for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) - if (desc->shadow_ptes[i] == spte) { - rmap_desc_remove_entry(rmapp, - desc, i, - prev_desc); - return; - } - prev_desc = desc; - desc = desc->more; - } - BUG(); - } -} - -static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte) -{ - struct kvm_rmap_desc *desc; - struct kvm_rmap_desc *prev_desc; - u64 *prev_spte; - int i; - - if (!*rmapp) - return NULL; - else if (!(*rmapp & 1)) { - if (!spte) - return (u64 *)*rmapp; - return NULL; - } - desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul); - prev_desc = NULL; - prev_spte = NULL; - while (desc) { - for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) { - if (prev_spte == spte) - return desc->shadow_ptes[i]; - prev_spte = desc->shadow_ptes[i]; - } - desc = desc->more; - } - return NULL; -} - -static void rmap_write_protect(struct kvm *kvm, u64 gfn) -{ - unsigned long *rmapp; - u64 *spte; - - gfn = unalias_gfn(kvm, gfn); - rmapp = gfn_to_rmap(kvm, gfn); - - spte = rmap_next(kvm, rmapp, NULL); - while (spte) { - BUG_ON(!spte); - BUG_ON(!(*spte & PT_PRESENT_MASK)); - rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte); - if (is_writeble_pte(*spte)) - set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK); - kvm_flush_remote_tlbs(kvm); - spte = rmap_next(kvm, rmapp, spte); - } -} - -#ifdef MMU_DEBUG -static int is_empty_shadow_page(u64 *spt) -{ - u64 *pos; - u64 *end; - - for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) - if ((*pos & ~PT_SHADOW_IO_MARK) != shadow_trap_nonpresent_pte) { - printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__, - pos, *pos); - return 0; - } - return 1; -} -#endif - -static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) -{ - ASSERT(is_empty_shadow_page(sp->spt)); - list_del(&sp->link); - __free_page(virt_to_page(sp->spt)); - __free_page(virt_to_page(sp->gfns)); - kfree(sp); - ++kvm->arch.n_free_mmu_pages; -} - -static unsigned kvm_page_table_hashfn(gfn_t gfn) -{ - return gfn; -} - -static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, - u64 *parent_pte) -{ - struct kvm_mmu_page *sp; - - if (!vcpu->kvm->arch.n_free_mmu_pages) - return NULL; - - sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp); - sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE); - sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE); - set_page_private(virt_to_page(sp->spt), (unsigned long)sp); - list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); - ASSERT(is_empty_shadow_page(sp->spt)); - sp->slot_bitmap = 0; - sp->multimapped = 0; - sp->parent_pte = parent_pte; - --vcpu->kvm->arch.n_free_mmu_pages; - return sp; -} - -static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp, u64 *parent_pte) -{ - struct kvm_pte_chain *pte_chain; - struct hlist_node *node; - int i; - - if (!parent_pte) - return; - if (!sp->multimapped) { - u64 *old = sp->parent_pte; - - if (!old) { - sp->parent_pte = parent_pte; - return; - } - sp->multimapped = 1; - pte_chain = mmu_alloc_pte_chain(vcpu); - INIT_HLIST_HEAD(&sp->parent_ptes); - hlist_add_head(&pte_chain->link, &sp->parent_ptes); - pte_chain->parent_ptes[0] = old; - } - hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) { - if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1]) - continue; - for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) - if (!pte_chain->parent_ptes[i]) { - pte_chain->parent_ptes[i] = parent_pte; - return; - } - } - pte_chain = mmu_alloc_pte_chain(vcpu); - BUG_ON(!pte_chain); - hlist_add_head(&pte_chain->link, &sp->parent_ptes); - pte_chain->parent_ptes[0] = parent_pte; -} - -static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, - u64 *parent_pte) -{ - struct kvm_pte_chain *pte_chain; - struct hlist_node *node; - int i; - - if (!sp->multimapped) { - BUG_ON(sp->parent_pte != parent_pte); - sp->parent_pte = NULL; - return; - } - hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) - for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) { - if (!pte_chain->parent_ptes[i]) - break; - if (pte_chain->parent_ptes[i] != parent_pte) - continue; - while (i + 1 < NR_PTE_CHAIN_ENTRIES - && pte_chain->parent_ptes[i + 1]) { - pte_chain->parent_ptes[i] - = pte_chain->parent_ptes[i + 1]; - ++i; - } - pte_chain->parent_ptes[i] = NULL; - if (i == 0) { - hlist_del(&pte_chain->link); - mmu_free_pte_chain(pte_chain); - if (hlist_empty(&sp->parent_ptes)) { - sp->multimapped = 0; - sp->parent_pte = NULL; - } - } - return; - } - BUG(); -} - -static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn) -{ - unsigned index; - struct hlist_head *bucket; - struct kvm_mmu_page *sp; - struct hlist_node *node; - - pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn); - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; - bucket = &kvm->arch.mmu_page_hash[index]; - hlist_for_each_entry(sp, node, bucket, hash_link) - if (sp->gfn == gfn && !sp->role.metaphysical) { - pgprintk("%s: found role %x\n", - __FUNCTION__, sp->role.word); - return sp; - } - return NULL; -} - -static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, - gfn_t gfn, - gva_t gaddr, - unsigned level, - int metaphysical, - unsigned access, - u64 *parent_pte, - bool *new_page) -{ - union kvm_mmu_page_role role; - unsigned index; - unsigned quadrant; - struct hlist_head *bucket; - struct kvm_mmu_page *sp; - struct hlist_node *node; - - role.word = 0; - role.glevels = vcpu->arch.mmu.root_level; - role.level = level; - role.metaphysical = metaphysical; - role.access = access; - if (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; - } - pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__, - gfn, role.word); - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; - bucket = &vcpu->kvm->arch.mmu_page_hash[index]; - hlist_for_each_entry(sp, node, bucket, hash_link) - if (sp->gfn == gfn && sp->role.word == role.word) { - mmu_page_add_parent_pte(vcpu, sp, parent_pte); - pgprintk("%s: found\n", __FUNCTION__); - return sp; - } - sp = kvm_mmu_alloc_page(vcpu, parent_pte); - if (!sp) - return sp; - pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word); - sp->gfn = gfn; - sp->role = role; - hlist_add_head(&sp->hash_link, bucket); - vcpu->arch.mmu.prefetch_page(vcpu, sp); - if (!metaphysical) - rmap_write_protect(vcpu->kvm, gfn); - if (new_page) - *new_page = 1; - return sp; -} - -static void kvm_mmu_page_unlink_children(struct kvm *kvm, - struct kvm_mmu_page *sp) -{ - unsigned i; - u64 *pt; - u64 ent; - - pt = sp->spt; - - if (sp->role.level == PT_PAGE_TABLE_LEVEL) { - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - if (is_shadow_present_pte(pt[i])) - rmap_remove(kvm, &pt[i]); - pt[i] = shadow_trap_nonpresent_pte; - } - kvm_flush_remote_tlbs(kvm); - return; - } - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - ent = pt[i]; - - pt[i] = shadow_trap_nonpresent_pte; - if (!is_shadow_present_pte(ent)) - continue; - ent &= PT64_BASE_ADDR_MASK; - mmu_page_remove_parent_pte(page_header(ent), &pt[i]); - } - kvm_flush_remote_tlbs(kvm); -} - -static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte) -{ - mmu_page_remove_parent_pte(sp, parent_pte); -} - -static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm) -{ - int i; - - for (i = 0; i < KVM_MAX_VCPUS; ++i) - if (kvm->vcpus[i]) - kvm->vcpus[i]->arch.last_pte_updated = NULL; -} - -static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp) -{ - u64 *parent_pte; - - ++kvm->stat.mmu_shadow_zapped; - while (sp->multimapped || sp->parent_pte) { - if (!sp->multimapped) - parent_pte = sp->parent_pte; - else { - struct kvm_pte_chain *chain; - - chain = container_of(sp->parent_ptes.first, - struct kvm_pte_chain, link); - parent_pte = chain->parent_ptes[0]; - } - BUG_ON(!parent_pte); - kvm_mmu_put_page(sp, parent_pte); - set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte); - } - kvm_mmu_page_unlink_children(kvm, sp); - if (!sp->root_count) { - hlist_del(&sp->hash_link); - kvm_mmu_free_page(kvm, sp); - } else - list_move(&sp->link, &kvm->arch.active_mmu_pages); - kvm_mmu_reset_last_pte_updated(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 - */ -void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_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 ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) > - kvm_nr_mmu_pages) { - int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages - - kvm->arch.n_free_mmu_pages; - - while (n_used_mmu_pages > kvm_nr_mmu_pages) { - struct kvm_mmu_page *page; - - page = container_of(kvm->arch.active_mmu_pages.prev, - struct kvm_mmu_page, link); - kvm_mmu_zap_page(kvm, page); - n_used_mmu_pages--; - } - kvm->arch.n_free_mmu_pages = 0; - } - 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; -} - -static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) -{ - unsigned index; - struct hlist_head *bucket; - struct kvm_mmu_page *sp; - struct hlist_node *node, *n; - int r; - - pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn); - r = 0; - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; - bucket = &kvm->arch.mmu_page_hash[index]; - hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) - if (sp->gfn == gfn && !sp->role.metaphysical) { - pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn, - sp->role.word); - kvm_mmu_zap_page(kvm, sp); - r = 1; - } - return r; -} - -static void mmu_unshadow(struct kvm *kvm, gfn_t gfn) -{ - struct kvm_mmu_page *sp; - - while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) { - pgprintk("%s: zap %lx %x\n", __FUNCTION__, gfn, sp->role.word); - kvm_mmu_zap_page(kvm, sp); - } -} - -static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn) -{ - int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn)); - struct kvm_mmu_page *sp = page_header(__pa(pte)); - - __set_bit(slot, &sp->slot_bitmap); -} - -struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva) -{ - gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva); - - if (gpa == UNMAPPED_GVA) - return NULL; - return gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT); -} - -static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, - unsigned pt_access, unsigned pte_access, - int user_fault, int write_fault, int dirty, - int *ptwrite, gfn_t gfn) -{ - u64 spte; - int was_rmapped = is_rmap_pte(*shadow_pte); - struct page *page; - - pgprintk("%s: spte %llx access %x write_fault %d" - " user_fault %d gfn %lx\n", - __FUNCTION__, *shadow_pte, pt_access, - write_fault, user_fault, gfn); - - /* - * We don't set the accessed bit, since we sometimes want to see - * whether the guest actually used the pte (in order to detect - * demand paging). - */ - spte = PT_PRESENT_MASK | PT_DIRTY_MASK; - if (!dirty) - pte_access &= ~ACC_WRITE_MASK; - if (!(pte_access & ACC_EXEC_MASK)) - spte |= PT64_NX_MASK; - - page = gfn_to_page(vcpu->kvm, gfn); - - spte |= PT_PRESENT_MASK; - if (pte_access & ACC_USER_MASK) - spte |= PT_USER_MASK; - - if (is_error_page(page)) { - set_shadow_pte(shadow_pte, - shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK); - kvm_release_page_clean(page); - return; - } - - spte |= page_to_phys(page); - - if ((pte_access & ACC_WRITE_MASK) - || (write_fault && !is_write_protection(vcpu) && !user_fault)) { - struct kvm_mmu_page *shadow; - - spte |= PT_WRITABLE_MASK; - if (user_fault) { - mmu_unshadow(vcpu->kvm, gfn); - goto unshadowed; - } - - shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn); - if (shadow) { - pgprintk("%s: found shadow page for %lx, marking ro\n", - __FUNCTION__, gfn); - pte_access &= ~ACC_WRITE_MASK; - if (is_writeble_pte(spte)) { - spte &= ~PT_WRITABLE_MASK; - kvm_x86_ops->tlb_flush(vcpu); - } - if (write_fault) - *ptwrite = 1; - } - } - -unshadowed: - - if (pte_access & ACC_WRITE_MASK) - mark_page_dirty(vcpu->kvm, gfn); - - pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte); - set_shadow_pte(shadow_pte, spte); - page_header_update_slot(vcpu->kvm, shadow_pte, gfn); - if (!was_rmapped) { - rmap_add(vcpu, shadow_pte, gfn); - if (!is_rmap_pte(*shadow_pte)) - kvm_release_page_clean(page); - } - else - kvm_release_page_clean(page); - if (!ptwrite || !*ptwrite) - vcpu->arch.last_pte_updated = shadow_pte; -} - -static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) -{ -} - -static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) -{ - int level = PT32E_ROOT_LEVEL; - hpa_t table_addr = vcpu->arch.mmu.root_hpa; - int pt_write = 0; - - for (; ; level--) { - u32 index = PT64_INDEX(v, level); - u64 *table; - - ASSERT(VALID_PAGE(table_addr)); - table = __va(table_addr); - - if (level == 1) { - mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL, - 0, write, 1, &pt_write, gfn); - return pt_write || is_io_pte(table[index]); - } - - if (table[index] == shadow_trap_nonpresent_pte) { - struct kvm_mmu_page *new_table; - gfn_t pseudo_gfn; - - pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK) - >> PAGE_SHIFT; - new_table = kvm_mmu_get_page(vcpu, pseudo_gfn, - v, level - 1, - 1, ACC_ALL, &table[index], - NULL); - if (!new_table) { - pgprintk("nonpaging_map: ENOMEM\n"); - return -ENOMEM; - } - - table[index] = __pa(new_table->spt) | PT_PRESENT_MASK - | PT_WRITABLE_MASK | PT_USER_MASK; - } - table_addr = table[index] & PT64_BASE_ADDR_MASK; - } -} - -static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp) -{ - int i; - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - sp->spt[i] = shadow_trap_nonpresent_pte; -} - -static void mmu_free_roots(struct kvm_vcpu *vcpu) -{ - int i; - struct kvm_mmu_page *sp; - - if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) - return; -#ifdef CONFIG_X86_64 - if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { - hpa_t root = vcpu->arch.mmu.root_hpa; - - sp = page_header(root); - --sp->root_count; - vcpu->arch.mmu.root_hpa = INVALID_PAGE; - return; - } -#endif - for (i = 0; i < 4; ++i) { - hpa_t root = vcpu->arch.mmu.pae_root[i]; - - if (root) { - root &= PT64_BASE_ADDR_MASK; - sp = page_header(root); - --sp->root_count; - } - vcpu->arch.mmu.pae_root[i] = INVALID_PAGE; - } - vcpu->arch.mmu.root_hpa = INVALID_PAGE; -} - -static void mmu_alloc_roots(struct kvm_vcpu *vcpu) -{ - int i; - gfn_t root_gfn; - struct kvm_mmu_page *sp; - - root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT; - -#ifdef CONFIG_X86_64 - if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { - hpa_t root = vcpu->arch.mmu.root_hpa; - - ASSERT(!VALID_PAGE(root)); - sp = kvm_mmu_get_page(vcpu, root_gfn, 0, - PT64_ROOT_LEVEL, 0, ACC_ALL, NULL, NULL); - root = __pa(sp->spt); - ++sp->root_count; - vcpu->arch.mmu.root_hpa = root; - return; - } -#endif - 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) { - if (!is_present_pte(vcpu->arch.pdptrs[i])) { - vcpu->arch.mmu.pae_root[i] = 0; - continue; - } - root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT; - } else if (vcpu->arch.mmu.root_level == 0) - root_gfn = 0; - sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, - PT32_ROOT_LEVEL, !is_paging(vcpu), - ACC_ALL, NULL, NULL); - root = __pa(sp->spt); - ++sp->root_count; - vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK; - } - vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root); -} - -static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr) -{ - return vaddr; -} - -static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, - u32 error_code) -{ - gfn_t gfn; - int r; - - pgprintk("%s: gva %lx error %x\n", __FUNCTION__, gva, error_code); - r = mmu_topup_memory_caches(vcpu); - if (r) - return r; - - ASSERT(vcpu); - ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa)); - - gfn = gva >> PAGE_SHIFT; - - return nonpaging_map(vcpu, gva & PAGE_MASK, - error_code & PFERR_WRITE_MASK, gfn); -} - -static void nonpaging_free(struct kvm_vcpu *vcpu) -{ - mmu_free_roots(vcpu); -} - -static int nonpaging_init_context(struct kvm_vcpu *vcpu) -{ - 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; - context->free = nonpaging_free; - context->prefetch_page = nonpaging_prefetch_page; - context->root_level = 0; - context->shadow_root_level = PT32E_ROOT_LEVEL; - context->root_hpa = INVALID_PAGE; - return 0; -} - -void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu) -{ - ++vcpu->stat.tlb_flush; - kvm_x86_ops->tlb_flush(vcpu); -} - -static void paging_new_cr3(struct kvm_vcpu *vcpu) -{ - pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->cr3); - mmu_free_roots(vcpu); -} - -static void inject_page_fault(struct kvm_vcpu *vcpu, - u64 addr, - u32 err_code) -{ - kvm_inject_page_fault(vcpu, addr, err_code); -} - -static void paging_free(struct kvm_vcpu *vcpu) -{ - nonpaging_free(vcpu); -} - -#define PTTYPE 64 -#include "paging_tmpl.h" -#undef PTTYPE - -#define PTTYPE 32 -#include "paging_tmpl.h" -#undef PTTYPE - -static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level) -{ - struct kvm_mmu *context = &vcpu->arch.mmu; - - ASSERT(is_pae(vcpu)); - context->new_cr3 = paging_new_cr3; - context->page_fault = paging64_page_fault; - context->gva_to_gpa = paging64_gva_to_gpa; - context->prefetch_page = paging64_prefetch_page; - context->free = paging_free; - context->root_level = level; - context->shadow_root_level = level; - context->root_hpa = INVALID_PAGE; - return 0; -} - -static int paging64_init_context(struct kvm_vcpu *vcpu) -{ - return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL); -} - -static int paging32_init_context(struct kvm_vcpu *vcpu) -{ - struct kvm_mmu *context = &vcpu->arch.mmu; - - context->new_cr3 = paging_new_cr3; - context->page_fault = paging32_page_fault; - context->gva_to_gpa = paging32_gva_to_gpa; - context->free = paging_free; - context->prefetch_page = paging32_prefetch_page; - context->root_level = PT32_ROOT_LEVEL; - context->shadow_root_level = PT32E_ROOT_LEVEL; - context->root_hpa = INVALID_PAGE; - return 0; -} - -static int paging32E_init_context(struct kvm_vcpu *vcpu) -{ - return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL); -} - -static int init_kvm_mmu(struct kvm_vcpu *vcpu) -{ - ASSERT(vcpu); - ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); - - if (!is_paging(vcpu)) - return nonpaging_init_context(vcpu); - else if (is_long_mode(vcpu)) - return paging64_init_context(vcpu); - else if (is_pae(vcpu)) - return paging32E_init_context(vcpu); - else - return paging32_init_context(vcpu); -} - -static void destroy_kvm_mmu(struct kvm_vcpu *vcpu) -{ - ASSERT(vcpu); - if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) { - vcpu->arch.mmu.free(vcpu); - vcpu->arch.mmu.root_hpa = INVALID_PAGE; - } -} - -int kvm_mmu_reset_context(struct kvm_vcpu *vcpu) -{ - destroy_kvm_mmu(vcpu); - return init_kvm_mmu(vcpu); -} -EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); - -int kvm_mmu_load(struct kvm_vcpu *vcpu) -{ - int r; - - mutex_lock(&vcpu->kvm->lock); - r = mmu_topup_memory_caches(vcpu); - if (r) - goto out; - mmu_alloc_roots(vcpu); - kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa); - kvm_mmu_flush_tlb(vcpu); -out: - mutex_unlock(&vcpu->kvm->lock); - return r; -} -EXPORT_SYMBOL_GPL(kvm_mmu_load); - -void kvm_mmu_unload(struct kvm_vcpu *vcpu) -{ - mmu_free_roots(vcpu); -} - -static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp, - u64 *spte) -{ - u64 pte; - struct kvm_mmu_page *child; - - pte = *spte; - if (is_shadow_present_pte(pte)) { - if (sp->role.level == PT_PAGE_TABLE_LEVEL) - rmap_remove(vcpu->kvm, spte); - else { - child = page_header(pte & PT64_BASE_ADDR_MASK); - mmu_page_remove_parent_pte(child, spte); - } - } - set_shadow_pte(spte, shadow_trap_nonpresent_pte); -} - -static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp, - u64 *spte, - const void *new, int bytes, - int offset_in_pte) -{ - if (sp->role.level != PT_PAGE_TABLE_LEVEL) { - ++vcpu->kvm->stat.mmu_pde_zapped; - return; - } - - ++vcpu->kvm->stat.mmu_pte_updated; - if (sp->role.glevels == PT32_ROOT_LEVEL) - paging32_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte); - else - paging64_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte); -} - -static bool need_remote_flush(u64 old, u64 new) -{ - if (!is_shadow_present_pte(old)) - return false; - if (!is_shadow_present_pte(new)) - return true; - if ((old ^ new) & PT64_BASE_ADDR_MASK) - return true; - old ^= PT64_NX_MASK; - new ^= PT64_NX_MASK; - return (old & ~new & PT64_PERM_MASK) != 0; -} - -static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new) -{ - if (need_remote_flush(old, new)) - kvm_flush_remote_tlbs(vcpu->kvm); - else - kvm_mmu_flush_tlb(vcpu); -} - -static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu) -{ - u64 *spte = vcpu->arch.last_pte_updated; - - return !!(spte && (*spte & PT_ACCESSED_MASK)); -} - -void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, - const u8 *new, int bytes) -{ - gfn_t gfn = gpa >> PAGE_SHIFT; - struct kvm_mmu_page *sp; - struct hlist_node *node, *n; - struct hlist_head *bucket; - unsigned index; - u64 entry; - u64 *spte; - unsigned offset = offset_in_page(gpa); - unsigned pte_size; - unsigned page_offset; - unsigned misaligned; - unsigned quadrant; - int level; - int flooded = 0; - int npte; - - pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes); - ++vcpu->kvm->stat.mmu_pte_write; - kvm_mmu_audit(vcpu, "pre pte write"); - if (gfn == vcpu->arch.last_pt_write_gfn - && !last_updated_pte_accessed(vcpu)) { - ++vcpu->arch.last_pt_write_count; - if (vcpu->arch.last_pt_write_count >= 3) - flooded = 1; - } else { - vcpu->arch.last_pt_write_gfn = gfn; - vcpu->arch.last_pt_write_count = 1; - vcpu->arch.last_pte_updated = NULL; - } - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; - bucket = &vcpu->kvm->arch.mmu_page_hash[index]; - hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) { - if (sp->gfn != gfn || sp->role.metaphysical) - continue; - pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8; - misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); - misaligned |= bytes < 4; - if (misaligned || flooded) { - /* - * Misaligned accesses are too much trouble to fix - * up; also, they usually indicate a page is not used - * as a page table. - * - * If we're seeing too many writes to a page, - * it may no longer be a page table, or we may be - * forking, in which case it is better to unmap the - * page. - */ - pgprintk("misaligned: gpa %llx bytes %d role %x\n", - gpa, bytes, sp->role.word); - kvm_mmu_zap_page(vcpu->kvm, sp); - ++vcpu->kvm->stat.mmu_flooded; - continue; - } - page_offset = offset; - level = sp->role.level; - npte = 1; - if (sp->role.glevels == PT32_ROOT_LEVEL) { - page_offset <<= 1; /* 32->64 */ - /* - * A 32-bit pde maps 4MB while the shadow pdes map - * only 2MB. So we need to double the offset again - * and zap two pdes instead of one. - */ - if (level == PT32_ROOT_LEVEL) { - page_offset &= ~7; /* kill rounding error */ - page_offset <<= 1; - npte = 2; - } - quadrant = page_offset >> PAGE_SHIFT; - page_offset &= ~PAGE_MASK; - if (quadrant != sp->role.quadrant) - continue; - } - spte = &sp->spt[page_offset / sizeof(*spte)]; - while (npte--) { - entry = *spte; - mmu_pte_write_zap_pte(vcpu, sp, spte); - mmu_pte_write_new_pte(vcpu, sp, spte, new, bytes, - page_offset & (pte_size - 1)); - mmu_pte_write_flush_tlb(vcpu, entry, *spte); - ++spte; - } - } - kvm_mmu_audit(vcpu, "post pte write"); -} - -int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) -{ - gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva); - - return kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); -} - -void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) -{ - while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) { - struct kvm_mmu_page *sp; - - sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev, - struct kvm_mmu_page, link); - kvm_mmu_zap_page(vcpu->kvm, sp); - ++vcpu->kvm->stat.mmu_recycled; - } -} - -int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code) -{ - int r; - enum emulation_result er; - - mutex_lock(&vcpu->kvm->lock); - r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code); - if (r < 0) - goto out; - - if (!r) { - r = 1; - goto out; - } - - r = mmu_topup_memory_caches(vcpu); - if (r) - goto out; - - er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0); - mutex_unlock(&vcpu->kvm->lock); - - switch (er) { - case EMULATE_DONE: - return 1; - case EMULATE_DO_MMIO: - ++vcpu->stat.mmio_exits; - return 0; - case EMULATE_FAIL: - kvm_report_emulation_failure(vcpu, "pagetable"); - return 1; - default: - BUG(); - } -out: - mutex_unlock(&vcpu->kvm->lock); - return r; -} -EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); - -static void free_mmu_pages(struct kvm_vcpu *vcpu) -{ - struct kvm_mmu_page *sp; - - while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) { - sp = container_of(vcpu->kvm->arch.active_mmu_pages.next, - struct kvm_mmu_page, link); - kvm_mmu_zap_page(vcpu->kvm, sp); - } - free_page((unsigned long)vcpu->arch.mmu.pae_root); -} - -static int alloc_mmu_pages(struct kvm_vcpu *vcpu) -{ - struct page *page; - int i; - - ASSERT(vcpu); - - if (vcpu->kvm->arch.n_requested_mmu_pages) - vcpu->kvm->arch.n_free_mmu_pages = - vcpu->kvm->arch.n_requested_mmu_pages; - else - vcpu->kvm->arch.n_free_mmu_pages = - vcpu->kvm->arch.n_alloc_mmu_pages; - /* - * 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 - * 4GB of memory, which happens to fit the DMA32 zone. - */ - page = alloc_page(GFP_KERNEL | __GFP_DMA32); - if (!page) - goto error_1; - vcpu->arch.mmu.pae_root = page_address(page); - for (i = 0; i < 4; ++i) - vcpu->arch.mmu.pae_root[i] = INVALID_PAGE; - - return 0; - -error_1: - free_mmu_pages(vcpu); - return -ENOMEM; -} - -int kvm_mmu_create(struct kvm_vcpu *vcpu) -{ - ASSERT(vcpu); - ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); - - return alloc_mmu_pages(vcpu); -} - -int kvm_mmu_setup(struct kvm_vcpu *vcpu) -{ - ASSERT(vcpu); - ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); - - 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; - - list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) { - int i; - u64 *pt; - - if (!test_bit(slot, &sp->slot_bitmap)) - continue; - - pt = sp->spt; - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - /* avoid RMW */ - if (pt[i] & PT_WRITABLE_MASK) - pt[i] &= ~PT_WRITABLE_MASK; - } -} - -void kvm_mmu_zap_all(struct kvm *kvm) -{ - struct kvm_mmu_page *sp, *node; - - list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) - kvm_mmu_zap_page(kvm, sp); - - kvm_flush_remote_tlbs(kvm); -} - -void kvm_mmu_module_exit(void) -{ - if (pte_chain_cache) - kmem_cache_destroy(pte_chain_cache); - if (rmap_desc_cache) - kmem_cache_destroy(rmap_desc_cache); - if (mmu_page_header_cache) - kmem_cache_destroy(mmu_page_header_cache); -} - -int kvm_mmu_module_init(void) -{ - pte_chain_cache = kmem_cache_create("kvm_pte_chain", - sizeof(struct kvm_pte_chain), - 0, 0, NULL); - if (!pte_chain_cache) - goto nomem; - rmap_desc_cache = kmem_cache_create("kvm_rmap_desc", - sizeof(struct kvm_rmap_desc), - 0, 0, NULL); - if (!rmap_desc_cache) - goto nomem; - - mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", - sizeof(struct kvm_mmu_page), - 0, 0, NULL); - if (!mmu_page_header_cache) - goto nomem; - - return 0; - -nomem: - kvm_mmu_module_exit(); - return -ENOMEM; -} - -/* - * Caculate mmu pages needed for kvm. - */ -unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm) -{ - int i; - unsigned int nr_mmu_pages; - unsigned int nr_pages = 0; - - for (i = 0; i < kvm->nmemslots; i++) - nr_pages += kvm->memslots[i].npages; - - nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000; - nr_mmu_pages = max(nr_mmu_pages, - (unsigned int) KVM_MIN_ALLOC_MMU_PAGES); - - return nr_mmu_pages; -} - -#ifdef AUDIT - -static const char *audit_msg; - -static gva_t canonicalize(gva_t gva) -{ -#ifdef CONFIG_X86_64 - gva = (long long)(gva << 16) >> 16; -#endif - return gva; -} - -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 (level > 1) { - if (ent == shadow_notrap_nonpresent_pte) - printk(KERN_ERR "audit: (%s) nontrapping pte" - " in nonleaf level: levels %d gva %lx" - " level %d pte %llx\n", audit_msg, - vcpu->arch.mmu.root_level, va, level, ent); - - audit_mappings_page(vcpu, ent, va, level - 1); - } else { - gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va); - struct page *page = gpa_to_page(vcpu, gpa); - hpa_t hpa = page_to_phys(page); - - 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_page_clean(page); - - } - } -} - -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) -{ - int nmaps = 0; - int i, j, k; - - for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { - struct kvm_memory_slot *m = &vcpu->kvm->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->shadow_ptes[k]) - ++nmaps; - else - break; - d = d->more; - } - } - } - return nmaps; -} - -static int count_writable_mappings(struct kvm_vcpu *vcpu) -{ - int nmaps = 0; - 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 (!(ent & PT_WRITABLE_MASK)) - continue; - ++nmaps; - } - } - return nmaps; -} - -static void audit_rmap(struct kvm_vcpu *vcpu) -{ - int n_rmap = count_rmaps(vcpu); - int n_actual = count_writable_mappings(vcpu); - - if (n_rmap != n_actual) - printk(KERN_ERR "%s: (%s) rmap %d actual %d\n", - __FUNCTION__, audit_msg, n_rmap, n_actual); -} - -static void audit_write_protection(struct kvm_vcpu *vcpu) -{ - struct kvm_mmu_page *sp; - struct kvm_memory_slot *slot; - unsigned long *rmapp; - gfn_t gfn; - - list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) { - if (sp->role.metaphysical) - continue; - - slot = gfn_to_memslot(vcpu->kvm, sp->gfn); - gfn = unalias_gfn(vcpu->kvm, sp->gfn); - rmapp = &slot->rmap[gfn - slot->base_gfn]; - if (*rmapp) - printk(KERN_ERR "%s: (%s) shadow page has writable" - " mappings: gfn %lx role %x\n", - __FUNCTION__, audit_msg, sp->gfn, - sp->role.word); - } -} - -static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) -{ - int olddbg = dbg; - - dbg = 0; - audit_msg = msg; - audit_rmap(vcpu); - audit_write_protection(vcpu); - audit_mappings(vcpu); - dbg = olddbg; -} - -#endif |