diff options
Diffstat (limited to 'drivers/kvm/mmu.c')
| -rw-r--r-- | drivers/kvm/mmu.c | 1454 |
1 files changed, 0 insertions, 1454 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c deleted file mode 100644 index 22c426cd8cb..00000000000 --- a/drivers/kvm/mmu.c +++ /dev/null @@ -1,1454 +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 <linux/types.h> -#include <linux/string.h> -#include <asm/page.h> -#include <linux/mm.h> -#include <linux/highmem.h> -#include <linux/module.h> - -#include "vmx.h" -#include "kvm.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 - -#define ASSERT(x) \ - if (!(x)) { \ - printk(KERN_WARNING "assertion failed %s:%d: %s\n", \ - __FILE__, __LINE__, #x); \ - } - -#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_MASK (1ULL << 63) - -#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 PT32_PTE_COPY_MASK \ - (PT_PRESENT_MASK | PT_ACCESSED_MASK | PT_DIRTY_MASK | PT_GLOBAL_MASK) - -#define PT64_PTE_COPY_MASK (PT64_NX_MASK | PT32_PTE_COPY_MASK) - -#define PT_FIRST_AVAIL_BITS_SHIFT 9 -#define PT64_SECOND_AVAIL_BITS_SHIFT 52 - -#define PT_SHADOW_PS_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) -#define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) - -#define PT_SHADOW_WRITABLE_SHIFT (PT_FIRST_AVAIL_BITS_SHIFT + 1) -#define PT_SHADOW_WRITABLE_MASK (1ULL << PT_SHADOW_WRITABLE_SHIFT) - -#define PT_SHADOW_USER_SHIFT (PT_SHADOW_WRITABLE_SHIFT + 1) -#define PT_SHADOW_USER_MASK (1ULL << (PT_SHADOW_USER_SHIFT)) - -#define PT_SHADOW_BITS_OFFSET (PT_SHADOW_WRITABLE_SHIFT - PT_WRITABLE_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) & PAGE_MASK) -#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 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 - -struct kvm_rmap_desc { - u64 *shadow_ptes[RMAP_EXT]; - struct kvm_rmap_desc *more; -}; - -static int is_write_protection(struct kvm_vcpu *vcpu) -{ - return vcpu->cr0 & CR0_WP_MASK; -} - -static int is_cpuid_PSE36(void) -{ - return 1; -} - -static int is_nx(struct kvm_vcpu *vcpu) -{ - return vcpu->shadow_efer & EFER_NX; -} - -static int is_present_pte(unsigned long pte) -{ - return pte & PT_PRESENT_MASK; -} - -static int is_writeble_pte(unsigned long pte) -{ - return pte & PT_WRITABLE_MASK; -} - -static int is_io_pte(unsigned long pte) -{ - return pte & PT_SHADOW_IO_MARK; -} - -static int is_rmap_pte(u64 pte) -{ - return (pte & (PT_WRITABLE_MASK | PT_PRESENT_MASK)) - == (PT_WRITABLE_MASK | PT_PRESENT_MASK); -} - -static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, - size_t objsize, int min) -{ - void *obj; - - if (cache->nobjs >= min) - return 0; - while (cache->nobjs < ARRAY_SIZE(cache->objects)) { - obj = kzalloc(objsize, GFP_NOWAIT); - 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_caches(struct kvm_vcpu *vcpu) -{ - int r; - - r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache, - sizeof(struct kvm_pte_chain), 4); - if (r) - goto out; - r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache, - sizeof(struct kvm_rmap_desc), 1); -out: - return r; -} - -static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) -{ - mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache); - mmu_free_memory_cache(&vcpu->mmu_rmap_desc_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 void mmu_memory_cache_free(struct kvm_mmu_memory_cache *mc, void *obj) -{ - if (mc->nobjs < KVM_NR_MEM_OBJS) - mc->objects[mc->nobjs++] = obj; - else - kfree(obj); -} - -static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu) -{ - return mmu_memory_cache_alloc(&vcpu->mmu_pte_chain_cache, - sizeof(struct kvm_pte_chain)); -} - -static void mmu_free_pte_chain(struct kvm_vcpu *vcpu, - struct kvm_pte_chain *pc) -{ - mmu_memory_cache_free(&vcpu->mmu_pte_chain_cache, pc); -} - -static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu) -{ - return mmu_memory_cache_alloc(&vcpu->mmu_rmap_desc_cache, - sizeof(struct kvm_rmap_desc)); -} - -static void mmu_free_rmap_desc(struct kvm_vcpu *vcpu, - struct kvm_rmap_desc *rd) -{ - mmu_memory_cache_free(&vcpu->mmu_rmap_desc_cache, rd); -} - -/* - * Reverse mapping data structures: - * - * If page->private bit zero is zero, then page->private points to the - * shadow page table entry that points to page_address(page). - * - * If page->private bit zero is one, (then page->private & ~1) points - * to a struct kvm_rmap_desc containing more mappings. - */ -static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte) -{ - struct page *page; - struct kvm_rmap_desc *desc; - int i; - - if (!is_rmap_pte(*spte)) - return; - page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT); - if (!page->private) { - rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte); - page->private = (unsigned long)spte; - } else if (!(page->private & 1)) { - rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte); - desc = mmu_alloc_rmap_desc(vcpu); - desc->shadow_ptes[0] = (u64 *)page->private; - desc->shadow_ptes[1] = spte; - page->private = (unsigned long)desc | 1; - } else { - rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte); - desc = (struct kvm_rmap_desc *)(page->private & ~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(struct kvm_vcpu *vcpu, - struct page *page, - 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] = 0; - if (j != 0) - return; - if (!prev_desc && !desc->more) - page->private = (unsigned long)desc->shadow_ptes[0]; - else - if (prev_desc) - prev_desc->more = desc->more; - else - page->private = (unsigned long)desc->more | 1; - mmu_free_rmap_desc(vcpu, desc); -} - -static void rmap_remove(struct kvm_vcpu *vcpu, u64 *spte) -{ - struct page *page; - struct kvm_rmap_desc *desc; - struct kvm_rmap_desc *prev_desc; - int i; - - if (!is_rmap_pte(*spte)) - return; - page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT); - if (!page->private) { - printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte); - BUG(); - } else if (!(page->private & 1)) { - rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte); - if ((u64 *)page->private != spte) { - printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n", - spte, *spte); - BUG(); - } - page->private = 0; - } else { - rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte); - desc = (struct kvm_rmap_desc *)(page->private & ~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(vcpu, page, - desc, i, - prev_desc); - return; - } - prev_desc = desc; - desc = desc->more; - } - BUG(); - } -} - -static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn) -{ - struct kvm *kvm = vcpu->kvm; - struct page *page; - struct kvm_memory_slot *slot; - struct kvm_rmap_desc *desc; - u64 *spte; - - slot = gfn_to_memslot(kvm, gfn); - BUG_ON(!slot); - page = gfn_to_page(slot, gfn); - - while (page->private) { - if (!(page->private & 1)) - spte = (u64 *)page->private; - else { - desc = (struct kvm_rmap_desc *)(page->private & ~1ul); - spte = desc->shadow_ptes[0]; - } - BUG_ON(!spte); - BUG_ON((*spte & PT64_BASE_ADDR_MASK) != - page_to_pfn(page) << PAGE_SHIFT); - BUG_ON(!(*spte & PT_PRESENT_MASK)); - BUG_ON(!(*spte & PT_WRITABLE_MASK)); - rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte); - rmap_remove(vcpu, spte); - kvm_arch_ops->tlb_flush(vcpu); - *spte &= ~(u64)PT_WRITABLE_MASK; - } -} - -static int is_empty_shadow_page(hpa_t page_hpa) -{ - u64 *pos; - u64 *end; - - for (pos = __va(page_hpa), end = pos + PAGE_SIZE / sizeof(u64); - pos != end; pos++) - if (*pos != 0) { - printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__, - pos, *pos); - return 0; - } - return 1; -} - -static void kvm_mmu_free_page(struct kvm_vcpu *vcpu, hpa_t page_hpa) -{ - struct kvm_mmu_page *page_head = page_header(page_hpa); - - ASSERT(is_empty_shadow_page(page_hpa)); - list_del(&page_head->link); - page_head->page_hpa = page_hpa; - list_add(&page_head->link, &vcpu->free_pages); - ++vcpu->kvm->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 *page; - - if (list_empty(&vcpu->free_pages)) - return NULL; - - page = list_entry(vcpu->free_pages.next, struct kvm_mmu_page, link); - list_del(&page->link); - list_add(&page->link, &vcpu->kvm->active_mmu_pages); - ASSERT(is_empty_shadow_page(page->page_hpa)); - page->slot_bitmap = 0; - page->global = 1; - page->multimapped = 0; - page->parent_pte = parent_pte; - --vcpu->kvm->n_free_mmu_pages; - return page; -} - -static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *page, u64 *parent_pte) -{ - struct kvm_pte_chain *pte_chain; - struct hlist_node *node; - int i; - - if (!parent_pte) - return; - if (!page->multimapped) { - u64 *old = page->parent_pte; - - if (!old) { - page->parent_pte = parent_pte; - return; - } - page->multimapped = 1; - pte_chain = mmu_alloc_pte_chain(vcpu); - INIT_HLIST_HEAD(&page->parent_ptes); - hlist_add_head(&pte_chain->link, &page->parent_ptes); - pte_chain->parent_ptes[0] = old; - } - hlist_for_each_entry(pte_chain, node, &page->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, &page->parent_ptes); - pte_chain->parent_ptes[0] = parent_pte; -} - -static void mmu_page_remove_parent_pte(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *page, - u64 *parent_pte) -{ - struct kvm_pte_chain *pte_chain; - struct hlist_node *node; - int i; - - if (!page->multimapped) { - BUG_ON(page->parent_pte != parent_pte); - page->parent_pte = NULL; - return; - } - hlist_for_each_entry(pte_chain, node, &page->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(vcpu, pte_chain); - if (hlist_empty(&page->parent_ptes)) { - page->multimapped = 0; - page->parent_pte = NULL; - } - } - return; - } - BUG(); -} - -static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm_vcpu *vcpu, - gfn_t gfn) -{ - unsigned index; - struct hlist_head *bucket; - struct kvm_mmu_page *page; - struct hlist_node *node; - - pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn); - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; - bucket = &vcpu->kvm->mmu_page_hash[index]; - hlist_for_each_entry(page, node, bucket, hash_link) - if (page->gfn == gfn && !page->role.metaphysical) { - pgprintk("%s: found role %x\n", - __FUNCTION__, page->role.word); - return page; - } - 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, - u64 *parent_pte) -{ - union kvm_mmu_page_role role; - unsigned index; - unsigned quadrant; - struct hlist_head *bucket; - struct kvm_mmu_page *page; - struct hlist_node *node; - - role.word = 0; - role.glevels = vcpu->mmu.root_level; - role.level = level; - role.metaphysical = metaphysical; - if (vcpu->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->mmu_page_hash[index]; - hlist_for_each_entry(page, node, bucket, hash_link) - if (page->gfn == gfn && page->role.word == role.word) { - mmu_page_add_parent_pte(vcpu, page, parent_pte); - pgprintk("%s: found\n", __FUNCTION__); - return page; - } - page = kvm_mmu_alloc_page(vcpu, parent_pte); - if (!page) - return page; - pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word); - page->gfn = gfn; - page->role = role; - hlist_add_head(&page->hash_link, bucket); - if (!metaphysical) - rmap_write_protect(vcpu, gfn); - return page; -} - -static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *page) -{ - unsigned i; - u64 *pt; - u64 ent; - - pt = __va(page->page_hpa); - - if (page->role.level == PT_PAGE_TABLE_LEVEL) { - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - if (pt[i] & PT_PRESENT_MASK) - rmap_remove(vcpu, &pt[i]); - pt[i] = 0; - } - kvm_arch_ops->tlb_flush(vcpu); - return; - } - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - ent = pt[i]; - - pt[i] = 0; - if (!(ent & PT_PRESENT_MASK)) - continue; - ent &= PT64_BASE_ADDR_MASK; - mmu_page_remove_parent_pte(vcpu, page_header(ent), &pt[i]); - } -} - -static void kvm_mmu_put_page(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *page, - u64 *parent_pte) -{ - mmu_page_remove_parent_pte(vcpu, page, parent_pte); -} - -static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *page) -{ - u64 *parent_pte; - - while (page->multimapped || page->parent_pte) { - if (!page->multimapped) - parent_pte = page->parent_pte; - else { - struct kvm_pte_chain *chain; - - chain = container_of(page->parent_ptes.first, - struct kvm_pte_chain, link); - parent_pte = chain->parent_ptes[0]; - } - BUG_ON(!parent_pte); - kvm_mmu_put_page(vcpu, page, parent_pte); - *parent_pte = 0; - } - kvm_mmu_page_unlink_children(vcpu, page); - if (!page->root_count) { - hlist_del(&page->hash_link); - kvm_mmu_free_page(vcpu, page->page_hpa); - } else { - list_del(&page->link); - list_add(&page->link, &vcpu->kvm->active_mmu_pages); - } -} - -static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn) -{ - unsigned index; - struct hlist_head *bucket; - struct kvm_mmu_page *page; - 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 = &vcpu->kvm->mmu_page_hash[index]; - hlist_for_each_entry_safe(page, node, n, bucket, hash_link) - if (page->gfn == gfn && !page->role.metaphysical) { - pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn, - page->role.word); - kvm_mmu_zap_page(vcpu, page); - r = 1; - } - return r; -} - -static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa) -{ - int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT)); - struct kvm_mmu_page *page_head = page_header(__pa(pte)); - - __set_bit(slot, &page_head->slot_bitmap); -} - -hpa_t safe_gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa) -{ - hpa_t hpa = gpa_to_hpa(vcpu, gpa); - - return is_error_hpa(hpa) ? bad_page_address | (gpa & ~PAGE_MASK): hpa; -} - -hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa) -{ - struct kvm_memory_slot *slot; - struct page *page; - - ASSERT((gpa & HPA_ERR_MASK) == 0); - slot = gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT); - if (!slot) - return gpa | HPA_ERR_MASK; - page = gfn_to_page(slot, gpa >> PAGE_SHIFT); - return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT) - | (gpa & (PAGE_SIZE-1)); -} - -hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva) -{ - gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva); - - if (gpa == UNMAPPED_GVA) - return UNMAPPED_GVA; - return gpa_to_hpa(vcpu, gpa); -} - -static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) -{ -} - -static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p) -{ - int level = PT32E_ROOT_LEVEL; - hpa_t table_addr = vcpu->mmu.root_hpa; - - for (; ; level--) { - u32 index = PT64_INDEX(v, level); - u64 *table; - u64 pte; - - ASSERT(VALID_PAGE(table_addr)); - table = __va(table_addr); - - if (level == 1) { - pte = table[index]; - if (is_present_pte(pte) && is_writeble_pte(pte)) - return 0; - mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT); - page_header_update_slot(vcpu->kvm, table, v); - table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK | - PT_USER_MASK; - rmap_add(vcpu, &table[index]); - return 0; - } - - if (table[index] == 0) { - 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, &table[index]); - if (!new_table) { - pgprintk("nonpaging_map: ENOMEM\n"); - return -ENOMEM; - } - - table[index] = new_table->page_hpa | PT_PRESENT_MASK - | PT_WRITABLE_MASK | PT_USER_MASK; - } - table_addr = table[index] & PT64_BASE_ADDR_MASK; - } -} - -static void mmu_free_roots(struct kvm_vcpu *vcpu) -{ - int i; - struct kvm_mmu_page *page; - -#ifdef CONFIG_X86_64 - if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) { - hpa_t root = vcpu->mmu.root_hpa; - - ASSERT(VALID_PAGE(root)); - page = page_header(root); - --page->root_count; - vcpu->mmu.root_hpa = INVALID_PAGE; - return; - } -#endif - for (i = 0; i < 4; ++i) { - hpa_t root = vcpu->mmu.pae_root[i]; - - ASSERT(VALID_PAGE(root)); - root &= PT64_BASE_ADDR_MASK; - page = page_header(root); - --page->root_count; - vcpu->mmu.pae_root[i] = INVALID_PAGE; - } - vcpu->mmu.root_hpa = INVALID_PAGE; -} - -static void mmu_alloc_roots(struct kvm_vcpu *vcpu) -{ - int i; - gfn_t root_gfn; - struct kvm_mmu_page *page; - - root_gfn = vcpu->cr3 >> PAGE_SHIFT; - -#ifdef CONFIG_X86_64 - if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) { - hpa_t root = vcpu->mmu.root_hpa; - - ASSERT(!VALID_PAGE(root)); - page = kvm_mmu_get_page(vcpu, root_gfn, 0, - PT64_ROOT_LEVEL, 0, NULL); - root = page->page_hpa; - ++page->root_count; - vcpu->mmu.root_hpa = root; - return; - } -#endif - for (i = 0; i < 4; ++i) { - hpa_t root = vcpu->mmu.pae_root[i]; - - ASSERT(!VALID_PAGE(root)); - if (vcpu->mmu.root_level == PT32E_ROOT_LEVEL) - root_gfn = vcpu->pdptrs[i] >> PAGE_SHIFT; - else if (vcpu->mmu.root_level == 0) - root_gfn = 0; - page = kvm_mmu_get_page(vcpu, root_gfn, i << 30, - PT32_ROOT_LEVEL, !is_paging(vcpu), - NULL); - root = page->page_hpa; - ++page->root_count; - vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK; - } - vcpu->mmu.root_hpa = __pa(vcpu->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) -{ - gpa_t addr = gva; - hpa_t paddr; - int r; - - r = mmu_topup_memory_caches(vcpu); - if (r) - return r; - - ASSERT(vcpu); - ASSERT(VALID_PAGE(vcpu->mmu.root_hpa)); - - - paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK); - - if (is_error_hpa(paddr)) - return 1; - - return nonpaging_map(vcpu, addr & PAGE_MASK, paddr); -} - -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->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->root_level = 0; - context->shadow_root_level = PT32E_ROOT_LEVEL; - mmu_alloc_roots(vcpu); - ASSERT(VALID_PAGE(context->root_hpa)); - kvm_arch_ops->set_cr3(vcpu, context->root_hpa); - return 0; -} - -static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu) -{ - ++kvm_stat.tlb_flush; - kvm_arch_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); - if (unlikely(vcpu->kvm->n_free_mmu_pages < KVM_MIN_FREE_MMU_PAGES)) - kvm_mmu_free_some_pages(vcpu); - mmu_alloc_roots(vcpu); - kvm_mmu_flush_tlb(vcpu); - kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa); -} - -static void mark_pagetable_nonglobal(void *shadow_pte) -{ - page_header(__pa(shadow_pte))->global = 0; -} - -static inline void set_pte_common(struct kvm_vcpu *vcpu, - u64 *shadow_pte, - gpa_t gaddr, - int dirty, - u64 access_bits, - gfn_t gfn) -{ - hpa_t paddr; - - *shadow_pte |= access_bits << PT_SHADOW_BITS_OFFSET; - if (!dirty) - access_bits &= ~PT_WRITABLE_MASK; - - paddr = gpa_to_hpa(vcpu, gaddr & PT64_BASE_ADDR_MASK); - - *shadow_pte |= access_bits; - - if (!(*shadow_pte & PT_GLOBAL_MASK)) - mark_pagetable_nonglobal(shadow_pte); - - if (is_error_hpa(paddr)) { - *shadow_pte |= gaddr; - *shadow_pte |= PT_SHADOW_IO_MARK; - *shadow_pte &= ~PT_PRESENT_MASK; - return; - } - - *shadow_pte |= paddr; - - if (access_bits & PT_WRITABLE_MASK) { - struct kvm_mmu_page *shadow; - - shadow = kvm_mmu_lookup_page(vcpu, gfn); - if (shadow) { - pgprintk("%s: found shadow page for %lx, marking ro\n", - __FUNCTION__, gfn); - access_bits &= ~PT_WRITABLE_MASK; - if (is_writeble_pte(*shadow_pte)) { - *shadow_pte &= ~PT_WRITABLE_MASK; - kvm_arch_ops->tlb_flush(vcpu); - } - } - } - - if (access_bits & PT_WRITABLE_MASK) - mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT); - - page_header_update_slot(vcpu->kvm, shadow_pte, gaddr); - rmap_add(vcpu, shadow_pte); -} - -static void inject_page_fault(struct kvm_vcpu *vcpu, - u64 addr, - u32 err_code) -{ - kvm_arch_ops->inject_page_fault(vcpu, addr, err_code); -} - -static inline int fix_read_pf(u64 *shadow_ent) -{ - if ((*shadow_ent & PT_SHADOW_USER_MASK) && - !(*shadow_ent & PT_USER_MASK)) { - /* - * If supervisor write protect is disabled, we shadow kernel - * pages as user pages so we can trap the write access. - */ - *shadow_ent |= PT_USER_MASK; - *shadow_ent &= ~PT_WRITABLE_MASK; - - return 1; - - } - return 0; -} - -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->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->free = paging_free; - context->root_level = level; - context->shadow_root_level = level; - mmu_alloc_roots(vcpu); - ASSERT(VALID_PAGE(context->root_hpa)); - kvm_arch_ops->set_cr3(vcpu, context->root_hpa | - (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK))); - 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->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->root_level = PT32_ROOT_LEVEL; - context->shadow_root_level = PT32E_ROOT_LEVEL; - mmu_alloc_roots(vcpu); - ASSERT(VALID_PAGE(context->root_hpa)); - kvm_arch_ops->set_cr3(vcpu, context->root_hpa | - (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK))); - 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->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->mmu.root_hpa)) { - vcpu->mmu.free(vcpu); - vcpu->mmu.root_hpa = INVALID_PAGE; - } -} - -int kvm_mmu_reset_context(struct kvm_vcpu *vcpu) -{ - int r; - - destroy_kvm_mmu(vcpu); - r = init_kvm_mmu(vcpu); - if (r < 0) - goto out; - r = mmu_topup_memory_caches(vcpu); -out: - return r; -} - -void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) -{ - gfn_t gfn = gpa >> PAGE_SHIFT; - struct kvm_mmu_page *page; - struct kvm_mmu_page *child; - struct hlist_node *node, *n; - struct hlist_head *bucket; - unsigned index; - u64 *spte; - u64 pte; - unsigned offset = offset_in_page(gpa); - unsigned pte_size; - unsigned page_offset; - unsigned misaligned; - int level; - int flooded = 0; - - pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes); - if (gfn == vcpu->last_pt_write_gfn) { - ++vcpu->last_pt_write_count; - if (vcpu->last_pt_write_count >= 3) - flooded = 1; - } else { - vcpu->last_pt_write_gfn = gfn; - vcpu->last_pt_write_count = 1; - } - index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; - bucket = &vcpu->kvm->mmu_page_hash[index]; - hlist_for_each_entry_safe(page, node, n, bucket, hash_link) { - if (page->gfn != gfn || page->role.metaphysical) - continue; - pte_size = page->role.glevels == PT32_ROOT_LEVEL ? 4 : 8; - misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); - 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, page->role.word); - kvm_mmu_zap_page(vcpu, page); - continue; - } - page_offset = offset; - level = page->role.level; - if (page->role.glevels == PT32_ROOT_LEVEL) { - page_offset <<= 1; /* 32->64 */ - page_offset &= ~PAGE_MASK; - } - spte = __va(page->page_hpa); - spte += page_offset / sizeof(*spte); - pte = *spte; - if (is_present_pte(pte)) { - if (level == PT_PAGE_TABLE_LEVEL) - rmap_remove(vcpu, spte); - else { - child = page_header(pte & PT64_BASE_ADDR_MASK); - mmu_page_remove_parent_pte(vcpu, child, spte); - } - } - *spte = 0; - } -} - -void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) -{ -} - -int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) -{ - gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva); - - return kvm_mmu_unprotect_page(vcpu, gpa >> PAGE_SHIFT); -} - -void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) -{ - while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) { - struct kvm_mmu_page *page; - - page = container_of(vcpu->kvm->active_mmu_pages.prev, - struct kvm_mmu_page, link); - kvm_mmu_zap_page(vcpu, page); - } -} -EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages); - -static void free_mmu_pages(struct kvm_vcpu *vcpu) -{ - struct kvm_mmu_page *page; - - while (!list_empty(&vcpu->kvm->active_mmu_pages)) { - page = container_of(vcpu->kvm->active_mmu_pages.next, - struct kvm_mmu_page, link); - kvm_mmu_zap_page(vcpu, page); - } - while (!list_empty(&vcpu->free_pages)) { - page = list_entry(vcpu->free_pages.next, - struct kvm_mmu_page, link); - list_del(&page->link); - __free_page(pfn_to_page(page->page_hpa >> PAGE_SHIFT)); - page->page_hpa = INVALID_PAGE; - } - free_page((unsigned long)vcpu->mmu.pae_root); -} - -static int alloc_mmu_pages(struct kvm_vcpu *vcpu) -{ - struct page *page; - int i; - - ASSERT(vcpu); - - for (i = 0; i < KVM_NUM_MMU_PAGES; i++) { - struct kvm_mmu_page *page_header = &vcpu->page_header_buf[i]; - - INIT_LIST_HEAD(&page_header->link); - if ((page = alloc_page(GFP_KERNEL)) == NULL) - goto error_1; - page->private = (unsigned long)page_header; - page_header->page_hpa = (hpa_t)page_to_pfn(page) << PAGE_SHIFT; - memset(__va(page_header->page_hpa), 0, PAGE_SIZE); - list_add(&page_header->link, &vcpu->free_pages); - ++vcpu->kvm->n_free_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->mmu.pae_root = page_address(page); - for (i = 0; i < 4; ++i) - vcpu->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->mmu.root_hpa)); - ASSERT(list_empty(&vcpu->free_pages)); - - return alloc_mmu_pages(vcpu); -} - -int kvm_mmu_setup(struct kvm_vcpu *vcpu) -{ - ASSERT(vcpu); - ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa)); - ASSERT(!list_empty(&vcpu->free_pages)); - - 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_vcpu *vcpu, int slot) -{ - struct kvm *kvm = vcpu->kvm; - struct kvm_mmu_page *page; - - list_for_each_entry(page, &kvm->active_mmu_pages, link) { - int i; - u64 *pt; - - if (!test_bit(slot, &page->slot_bitmap)) - continue; - - pt = __va(page->page_hpa); - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - /* avoid RMW */ - if (pt[i] & PT_WRITABLE_MASK) { - rmap_remove(vcpu, &pt[i]); - pt[i] &= ~PT_WRITABLE_MASK; - } - } -} - -#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 & PT_PRESENT_MASK) - continue; - - va = canonicalize(va); - if (level > 1) - audit_mappings_page(vcpu, ent, va, level - 1); - else { - gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, va); - hpa_t hpa = gpa_to_hpa(vcpu, gpa); - - if ((ent & PT_PRESENT_MASK) - && (ent & PT64_BASE_ADDR_MASK) != hpa) - printk(KERN_ERR "audit error: (%s) levels %d" - " gva %lx gpa %llx hpa %llx ent %llx\n", - audit_msg, vcpu->mmu.root_level, - va, gpa, hpa, ent); - } - } -} - -static void audit_mappings(struct kvm_vcpu *vcpu) -{ - int i; - - if (vcpu->mmu.root_level == 4) - audit_mappings_page(vcpu, vcpu->mmu.root_hpa, 0, 4); - else - for (i = 0; i < 4; ++i) - if (vcpu->mmu.pae_root[i] & PT_PRESENT_MASK) - audit_mappings_page(vcpu, - vcpu->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) { - struct page *page = m->phys_mem[j]; - - if (!page->private) - continue; - if (!(page->private & 1)) { - ++nmaps; - continue; - } - d = (struct kvm_rmap_desc *)(page->private & ~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 *page; - int i; - - list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) { - u64 *pt = __va(page->page_hpa); - - if (page->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 *page; - - list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) { - hfn_t hfn; - struct page *pg; - - if (page->role.metaphysical) - continue; - - hfn = gpa_to_hpa(vcpu, (gpa_t)page->gfn << PAGE_SHIFT) - >> PAGE_SHIFT; - pg = pfn_to_page(hfn); - if (pg->private) - printk(KERN_ERR "%s: (%s) shadow page has writable" - " mappings: gfn %lx role %x\n", - __FUNCTION__, audit_msg, page->gfn, - page->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 |