| /* |
| * 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 "mmu.h" |
| |
| #include <linux/kvm_host.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 <linux/hugetlb.h> |
| #include <linux/compiler.h> |
| |
| #include <asm/page.h> |
| #include <asm/cmpxchg.h> |
| #include <asm/io.h> |
| #include <asm/vmx.h> |
| |
| /* |
| * When setting this variable to true it enables Two-Dimensional-Paging |
| * where the hardware walks 2 page tables: |
| * 1. the guest-virtual to guest-physical |
| * 2. while doing 1. it walks guest-physical to host-physical |
| * If the hardware supports that we don't need to do shadow paging. |
| */ |
| bool tdp_enabled = false; |
| |
| #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 = 0; |
| module_param(dbg, bool, 0644); |
| #endif |
| |
| static int oos_shadow = 1; |
| module_param(oos_shadow, bool, 0644); |
| |
| #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 PT_FIRST_AVAIL_BITS_SHIFT 9 |
| #define PT64_SECOND_AVAIL_BITS_SHIFT 52 |
| |
| #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 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) |
| |
| #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) |
| |
| struct kvm_rmap_desc { |
| u64 *shadow_ptes[RMAP_EXT]; |
| struct kvm_rmap_desc *more; |
| }; |
| |
| struct kvm_shadow_walk { |
| int (*entry)(struct kvm_shadow_walk *walk, struct kvm_vcpu *vcpu, |
| u64 addr, u64 *spte, int level); |
| }; |
| |
| struct kvm_unsync_walk { |
| int (*entry) (struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk); |
| }; |
| |
| typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp); |
| |
| 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; |
| static u64 __read_mostly shadow_base_present_pte; |
| static u64 __read_mostly shadow_nx_mask; |
| static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */ |
| static u64 __read_mostly shadow_user_mask; |
| static u64 __read_mostly shadow_accessed_mask; |
| static u64 __read_mostly shadow_dirty_mask; |
| static u64 __read_mostly shadow_mt_mask; |
| |
| 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); |
| |
| void kvm_mmu_set_base_ptes(u64 base_pte) |
| { |
| shadow_base_present_pte = base_pte; |
| } |
| EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes); |
| |
| void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, |
| u64 dirty_mask, u64 nx_mask, u64 x_mask, u64 mt_mask) |
| { |
| shadow_user_mask = user_mask; |
| shadow_accessed_mask = accessed_mask; |
| shadow_dirty_mask = dirty_mask; |
| shadow_nx_mask = nx_mask; |
| shadow_x_mask = x_mask; |
| shadow_mt_mask = mt_mask; |
| } |
| EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_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) |
| { |
| return pte != shadow_trap_nonpresent_pte |
| && pte != shadow_notrap_nonpresent_pte; |
| } |
| |
| static int is_large_pte(u64 pte) |
| { |
| return pte & PT_PAGE_SIZE_MASK; |
| } |
| |
| static int is_writeble_pte(unsigned long pte) |
| { |
| return pte & PT_WRITABLE_MASK; |
| } |
| |
| static int is_dirty_pte(unsigned long pte) |
| { |
| return pte & shadow_dirty_mask; |
| } |
| |
| static int is_rmap_pte(u64 pte) |
| { |
| return is_shadow_present_pte(pte); |
| } |
| |
| static pfn_t spte_to_pfn(u64 pte) |
| { |
| return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| } |
| |
| 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; |
| |
| 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, 4); |
| 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); |
| } |
| |
| /* |
| * Return the pointer to the largepage write count for a given |
| * gfn, handling slots that are not large page aligned. |
| */ |
| static int *slot_largepage_idx(gfn_t gfn, struct kvm_memory_slot *slot) |
| { |
| unsigned long idx; |
| |
| idx = (gfn / KVM_PAGES_PER_HPAGE) - |
| (slot->base_gfn / KVM_PAGES_PER_HPAGE); |
| return &slot->lpage_info[idx].write_count; |
| } |
| |
| static void account_shadowed(struct kvm *kvm, gfn_t gfn) |
| { |
| int *write_count; |
| |
| gfn = unalias_gfn(kvm, gfn); |
| write_count = slot_largepage_idx(gfn, |
| gfn_to_memslot_unaliased(kvm, gfn)); |
| *write_count += 1; |
| } |
| |
| static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn) |
| { |
| int *write_count; |
| |
| gfn = unalias_gfn(kvm, gfn); |
| write_count = slot_largepage_idx(gfn, |
| gfn_to_memslot_unaliased(kvm, gfn)); |
| *write_count -= 1; |
| WARN_ON(*write_count < 0); |
| } |
| |
| static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn) |
| { |
| struct kvm_memory_slot *slot; |
| int *largepage_idx; |
| |
| gfn = unalias_gfn(kvm, gfn); |
| slot = gfn_to_memslot_unaliased(kvm, gfn); |
| if (slot) { |
| largepage_idx = slot_largepage_idx(gfn, slot); |
| return *largepage_idx; |
| } |
| |
| return 1; |
| } |
| |
| static int host_largepage_backed(struct kvm *kvm, gfn_t gfn) |
| { |
| struct vm_area_struct *vma; |
| unsigned long addr; |
| int ret = 0; |
| |
| addr = gfn_to_hva(kvm, gfn); |
| if (kvm_is_error_hva(addr)) |
| return ret; |
| |
| down_read(¤t->mm->mmap_sem); |
| vma = find_vma(current->mm, addr); |
| if (vma && is_vm_hugetlb_page(vma)) |
| ret = 1; |
| up_read(¤t->mm->mmap_sem); |
| |
| return ret; |
| } |
| |
| static int is_largepage_backed(struct kvm_vcpu *vcpu, gfn_t large_gfn) |
| { |
| struct kvm_memory_slot *slot; |
| |
| if (has_wrprotected_page(vcpu->kvm, large_gfn)) |
| return 0; |
| |
| if (!host_largepage_backed(vcpu->kvm, large_gfn)) |
| return 0; |
| |
| slot = gfn_to_memslot(vcpu->kvm, large_gfn); |
| if (slot && slot->dirty_bitmap) |
| return 0; |
| |
| return 1; |
| } |
| |
| /* |
| * 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, int lpage) |
| { |
| struct kvm_memory_slot *slot; |
| unsigned long idx; |
| |
| slot = gfn_to_memslot(kvm, gfn); |
| if (!lpage) |
| return &slot->rmap[gfn - slot->base_gfn]; |
| |
| idx = (gfn / KVM_PAGES_PER_HPAGE) - |
| (slot->base_gfn / KVM_PAGES_PER_HPAGE); |
| |
| return &slot->lpage_info[idx].rmap_pde; |
| } |
| |
| /* |
| * 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, int lpage) |
| { |
| 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, lpage); |
| 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; |
| pfn_t pfn; |
| unsigned long *rmapp; |
| int i; |
| |
| if (!is_rmap_pte(*spte)) |
| return; |
| sp = page_header(__pa(spte)); |
| pfn = spte_to_pfn(*spte); |
| if (*spte & shadow_accessed_mask) |
| kvm_set_pfn_accessed(pfn); |
| if (is_writeble_pte(*spte)) |
| kvm_release_pfn_dirty(pfn); |
| else |
| kvm_release_pfn_clean(pfn); |
| rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], is_large_pte(*spte)); |
| 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 int rmap_write_protect(struct kvm *kvm, u64 gfn) |
| { |
| unsigned long *rmapp; |
| u64 *spte; |
| int write_protected = 0; |
| |
| gfn = unalias_gfn(kvm, gfn); |
| rmapp = gfn_to_rmap(kvm, gfn, 0); |
| |
| 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); |
| write_protected = 1; |
| } |
| 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 */ |
| rmapp = gfn_to_rmap(kvm, gfn, 1); |
| spte = rmap_next(kvm, rmapp, NULL); |
| while (spte) { |
| BUG_ON(!spte); |
| BUG_ON(!(*spte & PT_PRESENT_MASK)); |
| BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)); |
| pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn); |
| if (is_writeble_pte(*spte)) { |
| rmap_remove(kvm, spte); |
| --kvm->stat.lpages; |
| set_shadow_pte(spte, shadow_trap_nonpresent_pte); |
| spte = NULL; |
| write_protected = 1; |
| } |
| spte = rmap_next(kvm, rmapp, spte); |
| } |
| |
| return write_protected; |
| } |
| |
| static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp) |
| { |
| u64 *spte; |
| int need_tlb_flush = 0; |
| |
| while ((spte = rmap_next(kvm, rmapp, NULL))) { |
| BUG_ON(!(*spte & PT_PRESENT_MASK)); |
| rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte); |
| rmap_remove(kvm, spte); |
| set_shadow_pte(spte, shadow_trap_nonpresent_pte); |
| need_tlb_flush = 1; |
| } |
| return need_tlb_flush; |
| } |
| |
| static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, |
| int (*handler)(struct kvm *kvm, unsigned long *rmapp)) |
| { |
| int i; |
| int retval = 0; |
| |
| /* |
| * If mmap_sem isn't taken, we can look the memslots with only |
| * the mmu_lock by skipping over the slots with userspace_addr == 0. |
| */ |
| for (i = 0; i < kvm->nmemslots; i++) { |
| struct kvm_memory_slot *memslot = &kvm->memslots[i]; |
| unsigned long start = memslot->userspace_addr; |
| unsigned long end; |
| |
| /* mmu_lock protects userspace_addr */ |
| if (!start) |
| continue; |
| |
| end = start + (memslot->npages << PAGE_SHIFT); |
| if (hva >= start && hva < end) { |
| gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT; |
| retval |= handler(kvm, &memslot->rmap[gfn_offset]); |
| retval |= handler(kvm, |
| &memslot->lpage_info[ |
| gfn_offset / |
| KVM_PAGES_PER_HPAGE].rmap_pde); |
| } |
| } |
| |
| return retval; |
| } |
| |
| int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) |
| { |
| return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); |
| } |
| |
| static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp) |
| { |
| u64 *spte; |
| int young = 0; |
| |
| /* always return old for EPT */ |
| if (!shadow_accessed_mask) |
| return 0; |
| |
| spte = rmap_next(kvm, rmapp, NULL); |
| while (spte) { |
| int _young; |
| u64 _spte = *spte; |
| BUG_ON(!(_spte & PT_PRESENT_MASK)); |
| _young = _spte & PT_ACCESSED_MASK; |
| if (_young) { |
| young = 1; |
| clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte); |
| } |
| spte = rmap_next(kvm, rmapp, spte); |
| } |
| return young; |
| } |
| |
| int kvm_age_hva(struct kvm *kvm, unsigned long hva) |
| { |
| return kvm_handle_hva(kvm, hva, kvm_age_rmapp); |
| } |
| |
| #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 (is_shadow_present_pte(*pos)) { |
| printk(KERN_ERR "%s: %p %llx\n", __func__, |
| 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 & ((1 << KVM_MMU_HASH_SHIFT) - 1); |
| } |
| |
| static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, |
| u64 *parent_pte) |
| { |
| struct kvm_mmu_page *sp; |
| |
| 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); |
| INIT_LIST_HEAD(&sp->oos_link); |
| ASSERT(is_empty_shadow_page(sp->spt)); |
| bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS); |
| sp->multimapped = 0; |
| sp->global = 1; |
| 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 void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, |
| mmu_parent_walk_fn fn) |
| { |
| struct kvm_pte_chain *pte_chain; |
| struct hlist_node *node; |
| struct kvm_mmu_page *parent_sp; |
| int i; |
| |
| if (!sp->multimapped && sp->parent_pte) { |
| parent_sp = page_header(__pa(sp->parent_pte)); |
| fn(vcpu, parent_sp); |
| mmu_parent_walk(vcpu, parent_sp, fn); |
| 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; |
| parent_sp = page_header(__pa(pte_chain->parent_ptes[i])); |
| fn(vcpu, parent_sp); |
| mmu_parent_walk(vcpu, parent_sp, fn); |
| } |
| } |
| |
| static void kvm_mmu_update_unsync_bitmap(u64 *spte) |
| { |
| unsigned int index; |
| struct kvm_mmu_page *sp = page_header(__pa(spte)); |
| |
| index = spte - sp->spt; |
| if (!__test_and_set_bit(index, sp->unsync_child_bitmap)) |
| sp->unsync_children++; |
| WARN_ON(!sp->unsync_children); |
| } |
| |
| static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp) |
| { |
| struct kvm_pte_chain *pte_chain; |
| struct hlist_node *node; |
| int i; |
| |
| if (!sp->parent_pte) |
| return; |
| |
| if (!sp->multimapped) { |
| kvm_mmu_update_unsync_bitmap(sp->parent_pte); |
| 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; |
| kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]); |
| } |
| } |
| |
| static int unsync_walk_fn(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
| { |
| kvm_mmu_update_parents_unsync(sp); |
| return 1; |
| } |
| |
| static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu *vcpu, |
| struct kvm_mmu_page *sp) |
| { |
| mmu_parent_walk(vcpu, sp, unsync_walk_fn); |
| kvm_mmu_update_parents_unsync(sp); |
| } |
| |
| 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 int nonpaging_sync_page(struct kvm_vcpu *vcpu, |
| struct kvm_mmu_page *sp) |
| { |
| return 1; |
| } |
| |
| static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva) |
| { |
| } |
| |
| #define KVM_PAGE_ARRAY_NR 16 |
| |
| struct kvm_mmu_pages { |
| struct mmu_page_and_offset { |
| struct kvm_mmu_page *sp; |
| unsigned int idx; |
| } page[KVM_PAGE_ARRAY_NR]; |
| unsigned int nr; |
| }; |
| |
| #define for_each_unsync_children(bitmap, idx) \ |
| for (idx = find_first_bit(bitmap, 512); \ |
| idx < 512; \ |
| idx = find_next_bit(bitmap, 512, idx+1)) |
| |
| int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, |
| int idx) |
| { |
| int i; |
| |
| if (sp->unsync) |
| for (i=0; i < pvec->nr; i++) |
| if (pvec->page[i].sp == sp) |
| return 0; |
| |
| pvec->page[pvec->nr].sp = sp; |
| pvec->page[pvec->nr].idx = idx; |
| pvec->nr++; |
| return (pvec->nr == KVM_PAGE_ARRAY_NR); |
| } |
| |
| static int __mmu_unsync_walk(struct kvm_mmu_page *sp, |
| struct kvm_mmu_pages *pvec) |
| { |
| int i, ret, nr_unsync_leaf = 0; |
| |
| for_each_unsync_children(sp->unsync_child_bitmap, i) { |
| u64 ent = sp->spt[i]; |
| |
| if (is_shadow_present_pte(ent) && !is_large_pte(ent)) { |
| struct kvm_mmu_page *child; |
| child = page_header(ent & PT64_BASE_ADDR_MASK); |
| |
| if (child->unsync_children) { |
| if (mmu_pages_add(pvec, child, i)) |
| return -ENOSPC; |
| |
| ret = __mmu_unsync_walk(child, pvec); |
| if (!ret) |
| __clear_bit(i, sp->unsync_child_bitmap); |
| else if (ret > 0) |
| nr_unsync_leaf += ret; |
| else |
| return ret; |
| } |
| |
| if (child->unsync) { |
| nr_unsync_leaf++; |
| if (mmu_pages_add(pvec, child, i)) |
| return -ENOSPC; |
| } |
| } |
| } |
| |
| if (find_first_bit(sp->unsync_child_bitmap, 512) == 512) |
| sp->unsync_children = 0; |
| |
| return nr_unsync_leaf; |
| } |
| |
| static int mmu_unsync_walk(struct kvm_mmu_page *sp, |
| struct kvm_mmu_pages *pvec) |
| { |
| if (!sp->unsync_children) |
| return 0; |
| |
| mmu_pages_add(pvec, sp, 0); |
| return __mmu_unsync_walk(sp, pvec); |
| } |
| |
| 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", __func__, gfn); |
| index = kvm_page_table_hashfn(gfn); |
| bucket = &kvm->arch.mmu_page_hash[index]; |
| hlist_for_each_entry(sp, node, bucket, hash_link) |
| if (sp->gfn == gfn && !sp->role.metaphysical |
| && !sp->role.invalid) { |
| pgprintk("%s: found role %x\n", |
| __func__, sp->role.word); |
| return sp; |
| } |
| return NULL; |
| } |
| |
| static void kvm_unlink_unsync_global(struct kvm *kvm, struct kvm_mmu_page *sp) |
| { |
| list_del(&sp->oos_link); |
| --kvm->stat.mmu_unsync_global; |
| } |
| |
| static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) |
| { |
| WARN_ON(!sp->unsync); |
| sp->unsync = 0; |
| if (sp->global) |
| kvm_unlink_unsync_global(kvm, sp); |
| --kvm->stat.mmu_unsync; |
| } |
| |
| static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp); |
| |
| static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
| { |
| if (sp->role.glevels != vcpu->arch.mmu.root_level) { |
| kvm_mmu_zap_page(vcpu->kvm, sp); |
| return 1; |
| } |
| |
| if (rmap_write_protect(vcpu->kvm, sp->gfn)) |
| kvm_flush_remote_tlbs(vcpu->kvm); |
| kvm_unlink_unsync_page(vcpu->kvm, sp); |
| if (vcpu->arch.mmu.sync_page(vcpu, sp)) { |
| kvm_mmu_zap_page(vcpu->kvm, sp); |
| return 1; |
| } |
| |
| kvm_mmu_flush_tlb(vcpu); |
| return 0; |
| } |
| |
| struct mmu_page_path { |
| struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1]; |
| unsigned int idx[PT64_ROOT_LEVEL-1]; |
| }; |
| |
| #define for_each_sp(pvec, sp, parents, i) \ |
| for (i = mmu_pages_next(&pvec, &parents, -1), \ |
| sp = pvec.page[i].sp; \ |
| i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ |
| i = mmu_pages_next(&pvec, &parents, i)) |
| |
| int mmu_pages_next(struct kvm_mmu_pages *pvec, struct mmu_page_path *parents, |
| int i) |
| { |
| int n; |
| |
| for (n = i+1; n < pvec->nr; n++) { |
| struct kvm_mmu_page *sp = pvec->page[n].sp; |
| |
| if (sp->role.level == PT_PAGE_TABLE_LEVEL) { |
| parents->idx[0] = pvec->page[n].idx; |
| return n; |
| } |
| |
| parents->parent[sp->role.level-2] = sp; |
| parents->idx[sp->role.level-1] = pvec->page[n].idx; |
| } |
| |
| return n; |
| } |
| |
| void mmu_pages_clear_parents(struct mmu_page_path *parents) |
| { |
| struct kvm_mmu_page *sp; |
| unsigned int level = 0; |
| |
| do { |
| unsigned int idx = parents->idx[level]; |
| |
| sp = parents->parent[level]; |
| if (!sp) |
| return; |
| |
| --sp->unsync_children; |
| WARN_ON((int)sp->unsync_children < 0); |
| __clear_bit(idx, sp->unsync_child_bitmap); |
| level++; |
| } while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children); |
| } |
| |
| static void kvm_mmu_pages_init(struct kvm_mmu_page *parent, |
| struct mmu_page_path *parents, |
| struct kvm_mmu_pages *pvec) |
| { |
| parents->parent[parent->role.level-1] = NULL; |
| pvec->nr = 0; |
| } |
| |
| static void mmu_sync_children(struct kvm_vcpu *vcpu, |
| struct kvm_mmu_page *parent) |
| { |
| int i; |
| struct kvm_mmu_page *sp; |
| struct mmu_page_path parents; |
| struct kvm_mmu_pages pages; |
| |
| kvm_mmu_pages_init(parent, &parents, &pages); |
| while (mmu_unsync_walk(parent, &pages)) { |
| int protected = 0; |
| |
| for_each_sp(pages, sp, parents, i) |
| protected |= rmap_write_protect(vcpu->kvm, sp->gfn); |
| |
| if (protected) |
| kvm_flush_remote_tlbs(vcpu->kvm); |
| |
| for_each_sp(pages, sp, parents, i) { |
| kvm_sync_page(vcpu, sp); |
| mmu_pages_clear_parents(&parents); |
| } |
| cond_resched_lock(&vcpu->kvm->mmu_lock); |
| kvm_mmu_pages_init(parent, &parents, &pages); |
| } |
| } |
| |
| 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) |
| { |
| union kvm_mmu_page_role role; |
| unsigned index; |
| unsigned quadrant; |
| struct hlist_head *bucket; |
| struct kvm_mmu_page *sp; |
| struct hlist_node *node, *tmp; |
| |
| 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", __func__, |
| gfn, role.word); |
| index = kvm_page_table_hashfn(gfn); |
| bucket = &vcpu->kvm->arch.mmu_page_hash[index]; |
| hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link) |
| if (sp->gfn == gfn) { |
| if (sp->unsync) |
| if (kvm_sync_page(vcpu, sp)) |
| continue; |
| |
| if (sp->role.word != role.word) |
| continue; |
| |
| mmu_page_add_parent_pte(vcpu, sp, parent_pte); |
| if (sp->unsync_children) { |
| set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests); |
| kvm_mmu_mark_parents_unsync(vcpu, sp); |
| } |
| pgprintk("%s: found\n", __func__); |
| return sp; |
| } |
| ++vcpu->kvm->stat.mmu_cache_miss; |
| sp = kvm_mmu_alloc_page(vcpu, parent_pte); |
| if (!sp) |
| return sp; |
| pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word); |
| sp->gfn = gfn; |
| sp->role = role; |
| hlist_add_head(&sp->hash_link, bucket); |
| if (!metaphysical) { |
| if (rmap_write_protect(vcpu->kvm, gfn)) |
| kvm_flush_remote_tlbs(vcpu->kvm); |
| account_shadowed(vcpu->kvm, gfn); |
| } |
| if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte) |
| vcpu->arch.mmu.prefetch_page(vcpu, sp); |
| else |
| nonpaging_prefetch_page(vcpu, sp); |
| return sp; |
| } |
| |
| static int walk_shadow(struct kvm_shadow_walk *walker, |
| struct kvm_vcpu *vcpu, u64 addr) |
| { |
| hpa_t shadow_addr; |
| int level; |
| int r; |
| u64 *sptep; |
| unsigned index; |
| |
| shadow_addr = vcpu->arch.mmu.root_hpa; |
| level = vcpu->arch.mmu.shadow_root_level; |
| if (level == PT32E_ROOT_LEVEL) { |
| shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3]; |
| shadow_addr &= PT64_BASE_ADDR_MASK; |
| if (!shadow_addr) |
| return 1; |
| --level; |
| } |
| |
| while (level >= PT_PAGE_TABLE_LEVEL) { |
| index = SHADOW_PT_INDEX(addr, level); |
| sptep = ((u64 *)__va(shadow_addr)) + index; |
| r = walker->entry(walker, vcpu, addr, sptep, level); |
| if (r) |
| return r; |
| shadow_addr = *sptep & PT64_BASE_ADDR_MASK; |
| --level; |
| } |
| return 0; |
| } |
| |
| 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; |
| } |
| return; |
| } |
| |
| for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { |
| ent = pt[i]; |
| |
| if (is_shadow_present_pte(ent)) { |
| if (!is_large_pte(ent)) { |
| ent &= PT64_BASE_ADDR_MASK; |
| mmu_page_remove_parent_pte(page_header(ent), |
| &pt[i]); |
| } else { |
| --kvm->stat.lpages; |
| rmap_remove(kvm, &pt[i]); |
| } |
| } |
| pt[i] = shadow_trap_nonpresent_pte; |
| } |
| } |
| |
| 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_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) |
| { |
| u64 *parent_pte; |
| |
| 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); |
| } |
| } |
| |
| static int mmu_zap_unsync_children(struct kvm *kvm, |
| struct kvm_mmu_page *parent) |
| { |
| int i, zapped = 0; |
| struct mmu_page_path parents; |
| struct kvm_mmu_pages pages; |
| |
| if (parent->role.level == PT_PAGE_TABLE_LEVEL) |
| return 0; |
| |
| kvm_mmu_pages_init(parent, &parents, &pages); |
| while (mmu_unsync_walk(parent, &pages)) { |
| struct kvm_mmu_page *sp; |
| |
| for_each_sp(pages, sp, parents, i) { |
| kvm_mmu_zap_page(kvm, sp); |
| mmu_pages_clear_parents(&parents); |
| } |
| zapped += pages.nr; |
| kvm_mmu_pages_init(parent, &parents, &pages); |
| } |
| |
| return zapped; |
| } |
| |
| static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp) |
| { |
| int ret; |
| ++kvm->stat.mmu_shadow_zapped; |
| ret = mmu_zap_unsync_children(kvm, sp); |
| kvm_mmu_page_unlink_children(kvm, sp); |
| kvm_mmu_unlink_parents(kvm, sp); |
| kvm_flush_remote_tlbs(kvm); |
| if (!sp->role.invalid && !sp->role.metaphysical) |
| unaccount_shadowed(kvm, sp->gfn); |
| if (sp->unsync) |
| kvm_unlink_unsync_page(kvm, sp); |
| if (!sp->root_count) { |
| hlist_del(&sp->hash_link); |
| kvm_mmu_free_page(kvm, sp); |
| } else { |
| sp->role.invalid = 1; |
| list_move(&sp->link, &kvm->arch.active_mmu_pages); |
| kvm_reload_remote_mmus(kvm); |
| } |
| kvm_mmu_reset_last_pte_updated(kvm); |
| return ret; |
| } |
| |
| /* |
| * 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", __func__, gfn); |
| r = 0; |
| index = kvm_page_table_hashfn(gfn); |
| 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", __func__, gfn, |
| sp->role.word); |
| r = 1; |
| if (kvm_mmu_zap_page(kvm, sp)) |
| n = bucket->first; |
| } |
| 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", __func__, 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); |
| } |
| |
| static void mmu_convert_notrap(struct kvm_mmu_page *sp) |
| { |
| int i; |
| u64 *pt = sp->spt; |
| |
| if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte) |
| return; |
| |
| for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { |
| if (pt[i] == shadow_notrap_nonpresent_pte) |
| set_shadow_pte(&pt[i], shadow_trap_nonpresent_pte); |
| } |
| } |
| |
| struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva) |
| { |
| struct page *page; |
| |
| gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva); |
| |
| if (gpa == UNMAPPED_GVA) |
| return NULL; |
| |
| page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT); |
| |
| return page; |
| } |
| |
| /* |
| * The function is based on mtrr_type_lookup() in |
| * arch/x86/kernel/cpu/mtrr/generic.c |
| */ |
| static int get_mtrr_type(struct mtrr_state_type *mtrr_state, |
| u64 start, u64 end) |
| { |
| int i; |
| u64 base, mask; |
| u8 prev_match, curr_match; |
| int num_var_ranges = KVM_NR_VAR_MTRR; |
| |
| if (!mtrr_state->enabled) |
| return 0xFF; |
| |
| /* Make end inclusive end, instead of exclusive */ |
| end--; |
| |
| /* Look in fixed ranges. Just return the type as per start */ |
| if (mtrr_state->have_fixed && (start < 0x100000)) { |
| int idx; |
| |
| if (start < 0x80000) { |
| idx = 0; |
| idx += (start >> 16); |
| return mtrr_state->fixed_ranges[idx]; |
| } else if (start < 0xC0000) { |
| idx = 1 * 8; |
| idx += ((start - 0x80000) >> 14); |
| return mtrr_state->fixed_ranges[idx]; |
| } else if (start < 0x1000000) { |
| idx = 3 * 8; |
| idx += ((start - 0xC0000) >> 12); |
| return mtrr_state->fixed_ranges[idx]; |
| } |
| } |
| |
| /* |
| * Look in variable ranges |
| * Look of multiple ranges matching this address and pick type |
| * as per MTRR precedence |
| */ |
| if (!(mtrr_state->enabled & 2)) |
| return mtrr_state->def_type; |
| |
| prev_match = 0xFF; |
| for (i = 0; i < num_var_ranges; ++i) { |
| unsigned short start_state, end_state; |
| |
| if (!(mtrr_state->var_ranges[i].mask_lo & (1 << 11))) |
| continue; |
| |
| base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) + |
| (mtrr_state->var_ranges[i].base_lo & PAGE_MASK); |
| mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) + |
| (mtrr_state->var_ranges[i].mask_lo & PAGE_MASK); |
| |
| start_state = ((start & mask) == (base & mask)); |
| end_state = ((end & mask) == (base & mask)); |
| if (start_state != end_state) |
| return 0xFE; |
| |
| if ((start & mask) != (base & mask)) |
| continue; |
| |
| curr_match = mtrr_state->var_ranges[i].base_lo & 0xff; |
| if (prev_match == 0xFF) { |
| prev_match = curr_match; |
| continue; |
| } |
| |
| if (prev_match == MTRR_TYPE_UNCACHABLE || |
| curr_match == MTRR_TYPE_UNCACHABLE) |
| return MTRR_TYPE_UNCACHABLE; |
| |
| if ((prev_match == MTRR_TYPE_WRBACK && |
| curr_match == MTRR_TYPE_WRTHROUGH) || |
| (prev_match == MTRR_TYPE_WRTHROUGH && |
| curr_match == MTRR_TYPE_WRBACK)) { |
| prev_match = MTRR_TYPE_WRTHROUGH; |
| curr_match = MTRR_TYPE_WRTHROUGH; |
| } |
| |
| if (prev_match != curr_match) |
| return MTRR_TYPE_UNCACHABLE; |
| } |
| |
| if (prev_match != 0xFF) |
| return prev_match; |
| |
| return mtrr_state->def_type; |
| } |
| |
| static u8 get_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| u8 mtrr; |
| |
| mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT, |
| (gfn << PAGE_SHIFT) + PAGE_SIZE); |
| if (mtrr == 0xfe || mtrr == 0xff) |
| mtrr = MTRR_TYPE_WRBACK; |
| return mtrr; |
| } |
| |
| static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
| { |
| unsigned index; |
| struct hlist_head *bucket; |
| struct kvm_mmu_page *s; |
| struct hlist_node *node, *n; |
| |
| index = kvm_page_table_hashfn(sp->gfn); |
| bucket = &vcpu->kvm->arch.mmu_page_hash[index]; |
| /* don't unsync if pagetable is shadowed with multiple roles */ |
| hlist_for_each_entry_safe(s, node, n, bucket, hash_link) { |
| if (s->gfn != sp->gfn || s->role.metaphysical) |
| continue; |
| if (s->role.word != sp->role.word) |
| return 1; |
| } |
| ++vcpu->kvm->stat.mmu_unsync; |
| sp->unsync = 1; |
| |
| if (sp->global) { |
| list_add(&sp->oos_link, &vcpu->kvm->arch.oos_global_pages); |
| ++vcpu->kvm->stat.mmu_unsync_global; |
| } else |
| kvm_mmu_mark_parents_unsync(vcpu, sp); |
| |
| mmu_convert_notrap(sp); |
| return 0; |
| } |
| |
| static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn, |
| bool can_unsync) |
| { |
| struct kvm_mmu_page *shadow; |
| |
| shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn); |
| if (shadow) { |
| if (shadow->role.level != PT_PAGE_TABLE_LEVEL) |
| return 1; |
| if (shadow->unsync) |
| return 0; |
| if (can_unsync && oos_shadow) |
| return kvm_unsync_page(vcpu, shadow); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, |
| unsigned pte_access, int user_fault, |
| int write_fault, int dirty, int largepage, |
| int global, gfn_t gfn, pfn_t pfn, bool speculative, |
| bool can_unsync) |
| { |
| u64 spte; |
| int ret = 0; |
| u64 mt_mask = shadow_mt_mask; |
| struct kvm_mmu_page *sp = page_header(__pa(shadow_pte)); |
| |
| if (!(vcpu->arch.cr4 & X86_CR4_PGE)) |
| global = 0; |
| if (!global && sp->global) { |
| sp->global = 0; |
| if (sp->unsync) { |
| kvm_unlink_unsync_global(vcpu->kvm, sp); |
| kvm_mmu_mark_parents_unsync(vcpu, sp); |
| } |
| } |
| |
| /* |
| * 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 = shadow_base_present_pte | shadow_dirty_mask; |
| if (!speculative) |
| spte |= shadow_accessed_mask; |
| if (!dirty) |
| pte_access &= ~ACC_WRITE_MASK; |
| if (pte_access & ACC_EXEC_MASK) |
| spte |= shadow_x_mask; |
| else |
| spte |= shadow_nx_mask; |
| if (pte_access & ACC_USER_MASK) |
| spte |= shadow_user_mask; |
| if (largepage) |
| spte |= PT_PAGE_SIZE_MASK; |
| if (mt_mask) { |
| if (!kvm_is_mmio_pfn(pfn)) { |
| mt_mask = get_memory_type(vcpu, gfn) << |
| kvm_x86_ops->get_mt_mask_shift(); |
| mt_mask |= VMX_EPT_IGMT_BIT; |
| } else |
| mt_mask = MTRR_TYPE_UNCACHABLE << |
| kvm_x86_ops->get_mt_mask_shift(); |
| spte |= mt_mask; |
| } |
| |
| spte |= (u64)pfn << PAGE_SHIFT; |
| |
| if ((pte_access & ACC_WRITE_MASK) |
| || (write_fault && !is_write_protection(vcpu) && !user_fault)) { |
| |
| if (largepage && has_wrprotected_page(vcpu->kvm, gfn)) { |
| ret = 1; |
| spte = shadow_trap_nonpresent_pte; |
| goto set_pte; |
| } |
| |
| spte |= PT_WRITABLE_MASK; |
| |
| /* |
| * Optimization: for pte sync, if spte was writable the hash |
| * lookup is unnecessary (and expensive). Write protection |
| * is responsibility of mmu_get_page / kvm_sync_page. |
| * Same reasoning can be applied to dirty page accounting. |
| */ |
| if (!can_unsync && is_writeble_pte(*shadow_pte)) |
| goto set_pte; |
| |
| if (mmu_need_write_protect(vcpu, gfn, can_unsync)) { |
| pgprintk("%s: found shadow page for %lx, marking ro\n", |
| __func__, gfn); |
| ret = 1; |
| pte_access &= ~ACC_WRITE_MASK; |
| if (is_writeble_pte(spte)) |
| spte &= ~PT_WRITABLE_MASK; |
| } |
| } |
| |
| if (pte_access & ACC_WRITE_MASK) |
| mark_page_dirty(vcpu->kvm, gfn); |
| |
| set_pte: |
| set_shadow_pte(shadow_pte, spte); |
| return ret; |
| } |
| |
| 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, int largepage, int global, |
| gfn_t gfn, pfn_t pfn, bool speculative) |
| { |
| int was_rmapped = 0; |
| int was_writeble = is_writeble_pte(*shadow_pte); |
| |
| pgprintk("%s: spte %llx access %x write_fault %d" |
| " user_fault %d gfn %lx\n", |
| __func__, *shadow_pte, pt_access, |
| write_fault, user_fault, gfn); |
| |
| if (is_rmap_pte(*shadow_pte)) { |
| /* |
| * If we overwrite a PTE page pointer with a 2MB PMD, unlink |
| * the parent of the now unreachable PTE. |
| */ |
| if (largepage && !is_large_pte(*shadow_pte)) { |
| struct kvm_mmu_page *child; |
| u64 pte = *shadow_pte; |
| |
| child = page_header(pte & PT64_BASE_ADDR_MASK); |
| mmu_page_remove_parent_pte(child, shadow_pte); |
| } else if (pfn != spte_to_pfn(*shadow_pte)) { |
| pgprintk("hfn old %lx new %lx\n", |
| spte_to_pfn(*shadow_pte), pfn); |
| rmap_remove(vcpu->kvm, shadow_pte); |
| } else { |
| if (largepage) |
| was_rmapped = is_large_pte(*shadow_pte); |
| else |
| was_rmapped = 1; |
| } |
| } |
| if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault, |
| dirty, largepage, global, gfn, pfn, speculative, true)) { |
| if (write_fault) |
| *ptwrite = 1; |
| kvm_x86_ops->tlb_flush(vcpu); |
| } |
| |
| pgprintk("%s: setting spte %llx\n", __func__, *shadow_pte); |
| pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n", |
| is_large_pte(*shadow_pte)? "2MB" : "4kB", |
| is_present_pte(*shadow_pte)?"RW":"R", gfn, |
| *shadow_pte, shadow_pte); |
| if (!was_rmapped && is_large_pte(*shadow_pte)) |
| ++vcpu->kvm->stat.lpages; |
| |
| page_header_update_slot(vcpu->kvm, shadow_pte, gfn); |
| if (!was_rmapped) { |
| rmap_add(vcpu, shadow_pte, gfn, largepage); |
| if (!is_rmap_pte(*shadow_pte)) |
| kvm_release_pfn_clean(pfn); |
| } else { |
| if (was_writeble) |
| kvm_release_pfn_dirty(pfn); |
| else |
| kvm_release_pfn_clean(pfn); |
| } |
| if (speculative) { |
| vcpu->arch.last_pte_updated = shadow_pte; |
| vcpu->arch.last_pte_gfn = gfn; |
| } |
| } |
| |
| static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) |
| { |
| } |
| |
| struct direct_shadow_walk { |
| struct kvm_shadow_walk walker; |
| pfn_t pfn; |
| int write; |
| int largepage; |
| int pt_write; |
| }; |
| |
| static int direct_map_entry(struct kvm_shadow_walk *_walk, |
| struct kvm_vcpu *vcpu, |
| u64 addr, u64 *sptep, int level) |
| { |
| struct direct_shadow_walk *walk = |
| container_of(_walk, struct direct_shadow_walk, walker); |
| struct kvm_mmu_page *sp; |
| gfn_t pseudo_gfn; |
| gfn_t gfn = addr >> PAGE_SHIFT; |
| |
| if (level == PT_PAGE_TABLE_LEVEL |
| || (walk->largepage && level == PT_DIRECTORY_LEVEL)) { |
| mmu_set_spte(vcpu, sptep, ACC_ALL, ACC_ALL, |
| 0, walk->write, 1, &walk->pt_write, |
| walk->largepage, 0, gfn, walk->pfn, false); |
| ++vcpu->stat.pf_fixed; |
| return 1; |
| } |
| |
| if (*sptep == shadow_trap_nonpresent_pte) { |
| pseudo_gfn = (addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| sp = kvm_mmu_get_page(vcpu, pseudo_gfn, (gva_t)addr, level - 1, |
| 1, ACC_ALL, sptep); |
| if (!sp) { |
| pgprintk("nonpaging_map: ENOMEM\n"); |
| kvm_release_pfn_clean(walk->pfn); |
| return -ENOMEM; |
| } |
| |
| set_shadow_pte(sptep, |
| __pa(sp->spt) |
| | PT_PRESENT_MASK | PT_WRITABLE_MASK |
| | shadow_user_mask | shadow_x_mask); |
| } |
| return 0; |
| } |
| |
| static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, |
| int largepage, gfn_t gfn, pfn_t pfn) |
| { |
| int r; |
| struct direct_shadow_walk walker = { |
| .walker = { .entry = direct_map_entry, }, |
| .pfn = pfn, |
| .largepage = largepage, |
| .write = write, |
| .pt_write = 0, |
| }; |
| |
| r = walk_shadow(&walker.walker, vcpu, gfn << PAGE_SHIFT); |
| if (r < 0) |
| return r; |
| return walker.pt_write; |
| } |
| |
| static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) |
| { |
| int r; |
| int largepage = 0; |
| pfn_t pfn; |
| unsigned long mmu_seq; |
| |
| if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) { |
| gfn &= ~(KVM_PAGES_PER_HPAGE-1); |
| largepage = 1; |
| } |
| |
| mmu_seq = vcpu->kvm->mmu_notifier_seq; |
| smp_rmb(); |
| pfn = gfn_to_pfn(vcpu->kvm, gfn); |
| |
| /* mmio */ |
| if (is_error_pfn(pfn)) { |
| kvm_release_pfn_clean(pfn); |
| return 1; |
| } |
| |
| spin_lock(&vcpu->kvm->mmu_lock); |
| if (mmu_notifier_retry(vcpu, mmu_seq)) |
| goto out_unlock; |
| kvm_mmu_free_some_pages(vcpu); |
| r = __direct_map(vcpu, v, write, largepage, gfn, pfn); |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| |
| |
| return r; |
| |
| out_unlock: |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| kvm_release_pfn_clean(pfn); |
| return 0; |
| } |
| |
| |
| 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; |
| spin_lock(&vcpu->kvm->mmu_lock); |
| 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; |
| if (!sp->root_count && sp->role.invalid) |
| kvm_mmu_zap_page(vcpu->kvm, sp); |
| vcpu->arch.mmu.root_hpa = INVALID_PAGE; |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| return; |
| } |
| 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; |
| if (!sp->root_count && sp->role.invalid) |
| kvm_mmu_zap_page(vcpu->kvm, sp); |
| } |
| vcpu->arch.mmu.pae_root[i] = INVALID_PAGE; |
| } |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| 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; |
| int metaphysical = 0; |
| |
| root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT; |
| |
| if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { |
| hpa_t root = vcpu->arch.mmu.root_hpa; |
| |
| ASSERT(!VALID_PAGE(root)); |
| if (tdp_enabled) |
| metaphysical = 1; |
| sp = kvm_mmu_get_page(vcpu, root_gfn, 0, |
| PT64_ROOT_LEVEL, metaphysical, |
| ACC_ALL, NULL); |
| root = __pa(sp->spt); |
| ++sp->root_count; |
| vcpu->arch.mmu.root_hpa = root; |
| return; |
| } |
| metaphysical = !is_paging(vcpu); |
| if (tdp_enabled) |
| metaphysical = 1; |
| 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, metaphysical, |
| ACC_ALL, 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 void mmu_sync_roots(struct kvm_vcpu *vcpu) |
| { |
| 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_sync_children(vcpu, sp); |
| return; |
| } |
| 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); |
| mmu_sync_children(vcpu, sp); |
| } |
| } |
| } |
| |
| static void mmu_sync_global(struct kvm_vcpu *vcpu) |
| { |
| struct kvm *kvm = vcpu->kvm; |
| struct kvm_mmu_page *sp, *n; |
| |
| list_for_each_entry_safe(sp, n, &kvm->arch.oos_global_pages, oos_link) |
| kvm_sync_page(vcpu, sp); |
| } |
| |
| void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) |
| { |
| spin_lock(&vcpu->kvm->mmu_lock); |
| mmu_sync_roots(vcpu); |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| } |
| |
| void kvm_mmu_sync_global(struct kvm_vcpu *vcpu) |
| { |
| spin_lock(&vcpu->kvm->mmu_lock); |
| mmu_sync_global(vcpu); |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| } |
| |
| 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", __func__, 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 int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, |
| u32 error_code) |
| { |
| pfn_t pfn; |
| int r; |
| int largepage = 0; |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| unsigned long mmu_seq; |
| |
| ASSERT(vcpu); |
| ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa)); |
| |
| r = mmu_topup_memory_caches(vcpu); |
| if (r) |
| return r; |
| |
| if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) { |
| gfn &= ~(KVM_PAGES_PER_HPAGE-1); |
| largepage = 1; |
| } |
| mmu_seq = vcpu->kvm->mmu_notifier_seq; |
| smp_rmb(); |
| pfn = gfn_to_pfn(vcpu->kvm, gfn); |
| if (is_error_pfn(pfn)) { |
| kvm_release_pfn_clean(pfn); |
| return 1; |
| } |
| spin_lock(&vcpu->kvm->mmu_lock); |
| if (mmu_notifier_retry(vcpu, mmu_seq)) |
| goto out_unlock; |
| kvm_mmu_free_some_pages(vcpu); |
| r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK, |
| largepage, gfn, pfn); |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| |
| return r; |
| |
| out_unlock: |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| kvm_release_pfn_clean(pfn); |
| return 0; |
| } |
| |
| 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->sync_page = nonpaging_sync_page; |
| context->invlpg = nonpaging_invlpg; |
| 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", __func__, vcpu->arch.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->sync_page = paging64_sync_page; |
| context->invlpg = paging64_invlpg; |
| 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->sync_page = paging32_sync_page; |
| context->invlpg = paging32_invlpg; |
| 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_tdp_mmu(struct kvm_vcpu *vcpu) |
| { |
| struct kvm_mmu *context = &vcpu->arch.mmu; |
| |
| context->new_cr3 = nonpaging_new_cr3; |
| context->page_fault = tdp_page_fault; |
| context->free = nonpaging_free; |
| context->prefetch_page = nonpaging_prefetch_page; |
| context->sync_page = nonpaging_sync_page; |
| context->invlpg = nonpaging_invlpg; |
| context->shadow_root_level = kvm_x86_ops->get_tdp_level(); |
| context->root_hpa = INVALID_PAGE; |
| |
| if (!is_paging(vcpu)) { |
| context->gva_to_gpa = nonpaging_gva_to_gpa; |
| context->root_level = 0; |
| } else if (is_long_mode(vcpu)) { |
| context->gva_to_gpa = paging64_gva_to_gpa; |
| context->root_level = PT64_ROOT_LEVEL; |
| } else if (is_pae(vcpu)) { |
| context->gva_to_gpa = paging64_gva_to_gpa; |
| context->root_level = PT32E_ROOT_LEVEL; |
| } else { |
| context->gva_to_gpa = paging32_gva_to_gpa; |
| context->root_level = PT32_ROOT_LEVEL; |
| } |
| |
| return 0; |
| } |
| |
| static int init_kvm_softmmu(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 int init_kvm_mmu(struct kvm_vcpu *vcpu) |
| { |
| vcpu->arch.update_pte.pfn = bad_pfn; |
| |
| if (tdp_enabled) |
| return init_kvm_tdp_mmu(vcpu); |
| else |
| return init_kvm_softmmu(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; |
| |
| r = mmu_topup_memory_caches(vcpu); |
| if (r) |
| goto out; |
| spin_lock(&vcpu->kvm->mmu_lock); |
| kvm_mmu_free_some_pages(vcpu); |
| mmu_alloc_roots(vcpu); |
| mmu_sync_roots(vcpu); |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa); |
| kvm_mmu_flush_tlb(vcpu); |
| out: |
| 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 || |
| is_large_pte(pte)) |
| 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); |
| if (is_large_pte(pte)) |
| --vcpu->kvm->stat.lpages; |
| } |
| |
| static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu, |
| struct kvm_mmu_page *sp, |
| u64 *spte, |
| const void *new) |
| { |
| if (sp->role.level != PT_PAGE_TABLE_LEVEL) { |
| if (!vcpu->arch.update_pte.largepage || |
| sp->role.glevels == PT32_ROOT_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); |
| else |
| paging64_update_pte(vcpu, sp, spte, new); |
| } |
| |
| 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 & shadow_accessed_mask)); |
| } |
| |
| static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, |
| const u8 *new, int bytes) |
| { |
| gfn_t gfn; |
| int r; |
| u64 gpte = 0; |
| pfn_t pfn; |
| |
| vcpu->arch.update_pte.largepage = 0; |
| |
| if (bytes != 4 && bytes != 8) |
| return; |
| |
| /* |
| * Assume that the pte write on a page table of the same type |
| * as the current vcpu paging mode. This is nearly always true |
| * (might be false while changing modes). Note it is verified later |
| * by update_pte(). |
| */ |
| if (is_pae(vcpu)) { |
| /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ |
| if ((bytes == 4) && (gpa % 4 == 0)) { |
| r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8); |
| if (r) |
| return; |
| memcpy((void *)&gpte + (gpa % 8), new, 4); |
| } else if ((bytes == 8) && (gpa % 8 == 0)) { |
| memcpy((void *)&gpte, new, 8); |
| } |
| } else { |
| if ((bytes == 4) && (gpa % 4 == 0)) |
| memcpy((void *)&gpte, new, 4); |
| } |
| if (!is_present_pte(gpte)) |
| return; |
| gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| |
| if (is_large_pte(gpte) && is_largepage_backed(vcpu, gfn)) { |
| gfn &= ~(KVM_PAGES_PER_HPAGE-1); |
| vcpu->arch.update_pte.largepage = 1; |
| } |
| vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq; |
| smp_rmb(); |
| pfn = gfn_to_pfn(vcpu->kvm, gfn); |
| |
| if (is_error_pfn(pfn)) { |
| kvm_release_pfn_clean(pfn); |
| return; |
| } |
| vcpu->arch.update_pte.gfn = gfn; |
| vcpu->arch.update_pte.pfn = pfn; |
| } |
| |
| static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| u64 *spte = vcpu->arch.last_pte_updated; |
| |
| if (spte |
| && vcpu->arch.last_pte_gfn == gfn |
| && shadow_accessed_mask |
| && !(*spte & shadow_accessed_mask) |
| && is_shadow_present_pte(*spte)) |
| set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte); |
| } |
| |
| void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, |
| const u8 *new, int bytes, |
| bool guest_initiated) |
| { |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| struct kvm_mmu_page *sp; |
| struct hlist_node *node, *n; |
| struct hlist_head *bucket; |
| unsigned index; |
| u64 entry, gentry; |
| 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; |
| int r; |
| |
| pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); |
| mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes); |
| spin_lock(&vcpu->kvm->mmu_lock); |
| 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"); |
| if (guest_initiated) { |
| 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); |
| 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 || sp->role.invalid) |
| 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); |
| if (kvm_mmu_zap_page(vcpu->kvm, sp)) |
| n = bucket->first; |
| ++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)]; |
| if ((gpa & (pte_size - 1)) || (bytes < pte_size)) { |
| gentry = 0; |
| r = kvm_read_guest_atomic(vcpu->kvm, |
| gpa & ~(u64)(pte_size - 1), |
| &gentry, pte_size); |
| new = (const void *)&gentry; |
| if (r < 0) |
| new = NULL; |
| } |
| while (npte--) { |
| entry = *spte; |
| mmu_pte_write_zap_pte(vcpu, sp, spte); |
| if (new) |
| mmu_pte_write_new_pte(vcpu, sp, spte, new); |
| mmu_pte_write_flush_tlb(vcpu, entry, *spte); |
| ++spte; |
| } |
| } |
| kvm_mmu_audit(vcpu, "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); |
| vcpu->arch.update_pte.pfn = bad_pfn; |
| } |
| } |
| |
| int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) |
| { |
| gpa_t gpa; |
| int r; |
| |
| gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva); |
| |
| spin_lock(&vcpu->kvm->mmu_lock); |
| r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| return r; |
| } |
| EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt); |
| |
| 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; |
| |
| 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); |
| |
| 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: |
| return r; |
| } |
| EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); |
| |
| void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) |
| { |
| vcpu->arch.mmu.invlpg(vcpu, gva); |
| kvm_mmu_flush_tlb(vcpu); |
| ++vcpu->stat.invlpg; |
| } |
| EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); |
| |
| void kvm_enable_tdp(void) |
| { |
| tdp_enabled = true; |
| } |
| EXPORT_SYMBOL_GPL(kvm_enable_tdp); |
| |
| void kvm_disable_tdp(void) |
| { |
| tdp_enabled = false; |
| } |
| EXPORT_SYMBOL_GPL(kvm_disable_tdp); |
| |
| 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); |
| cond_resched(); |
| } |
| 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; |
| |
| spin_lock(&kvm->mmu_lock); |
| 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; |
| } |
| kvm_flush_remote_tlbs(kvm); |
| spin_unlock(&kvm->mmu_lock); |
| } |
| |
| void kvm_mmu_zap_all(struct kvm *kvm) |
| { |
| struct kvm_mmu_page *sp, *node; |
| |
| spin_lock(&kvm->mmu_lock); |
| list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) |
| if (kvm_mmu_zap_page(kvm, sp)) |
| node = container_of(kvm->arch.active_mmu_pages.next, |
| struct kvm_mmu_page, link); |
| spin_unlock(&kvm->mmu_lock); |
| |
| kvm_flush_remote_tlbs(kvm); |
| } |
| |
| static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm) |
| { |
| 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); |
| } |
| |
| static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask) |
| { |
| struct kvm *kvm; |
| struct kvm *kvm_freed = NULL; |
| int cache_count = 0; |
| |
| spin_lock(&kvm_lock); |
| |
| list_for_each_entry(kvm, &vm_list, vm_list) { |
| int npages; |
| |
| if (!down_read_trylock(&kvm->slots_lock)) |
| continue; |
| 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) { |
| kvm_mmu_remove_one_alloc_mmu_page(kvm); |
| cache_count--; |
| kvm_freed = kvm; |
| } |
| nr_to_scan--; |
| |
| spin_unlock(&kvm->mmu_lock); |
| up_read(&kvm->slots_lock); |
| } |
| if (kvm_freed) |
| list_move_tail(&kvm_freed->vm_list, &vm_list); |
| |
| spin_unlock(&kvm_lock); |
| |
| return cache_count; |
| } |
| |
| static struct shrinker mmu_shrinker = { |
| .shrink = mmu_shrink, |
| .seeks = DEFAULT_SEEKS * 10, |
| }; |
| |
| static void mmu_destroy_caches(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); |
| } |
| |
| void kvm_mmu_module_exit(void) |
| { |
| mmu_destroy_caches(); |
| unregister_shrinker(&mmu_shrinker); |
| } |
| |
| 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; |
| |
| register_shrinker(&mmu_shrinker); |
| |
| return 0; |
| |
| nomem: |
| mmu_destroy_caches(); |
| 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; |
| } |
| |
| static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer, |
| unsigned len) |
| { |
| if (len > buffer->len) |
| return NULL; |
| return buffer->ptr; |
| } |
| |
| static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer, |
| unsigned len) |
| { |
| void *ret; |
| |
| ret = pv_mmu_peek_buffer(buffer, len); |
| if (!ret) |
| return ret; |
| buffer->ptr += len; |
| buffer->len -= len; |
| buffer->processed += len; |
| return ret; |
| } |
| |
| static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu, |
| gpa_t addr, gpa_t value) |
| { |
| int bytes = 8; |
| int r; |
| |
| if (!is_long_mode(vcpu) && !is_pae(vcpu)) |
| bytes = 4; |
| |
| r = mmu_topup_memory_caches(vcpu); |
| if (r) |
| return r; |
| |
| if (!emulator_write_phys(vcpu, addr, &value, bytes)) |
| return -EFAULT; |
| |
| return 1; |
| } |
| |
| static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu) |
| { |
| kvm_x86_ops->tlb_flush(vcpu); |
| set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests); |
| return 1; |
| } |
| |
| static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr) |
| { |
| spin_lock(&vcpu->kvm->mmu_lock); |
| mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT); |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| return 1; |
| } |
| |
| static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu, |
| struct kvm_pv_mmu_op_buffer *buffer) |
| { |
| struct kvm_mmu_op_header *header; |
| |
| header = pv_mmu_peek_buffer(buffer, sizeof *header); |
| if (!header) |
| return 0; |
| switch (header->op) { |
| case KVM_MMU_OP_WRITE_PTE: { |
| struct kvm_mmu_op_write_pte *wpte; |
| |
| wpte = pv_mmu_read_buffer(buffer, sizeof *wpte); |
| if (!wpte) |
| return 0; |
| return kvm_pv_mmu_write(vcpu, wpte->pte_phys, |
| wpte->pte_val); |
| } |
| case KVM_MMU_OP_FLUSH_TLB: { |
| struct kvm_mmu_op_flush_tlb *ftlb; |
| |
| ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb); |
| if (!ftlb) |
| return 0; |
| return kvm_pv_mmu_flush_tlb(vcpu); |
| } |
| case KVM_MMU_OP_RELEASE_PT: { |
| struct kvm_mmu_op_release_pt *rpt; |
| |
| rpt = pv_mmu_read_buffer(buffer, sizeof *rpt); |
| if (!rpt) |
| return 0; |
| return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys); |
| } |
| default: return 0; |
| } |
| } |
| |
| int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, |
| gpa_t addr, unsigned long *ret) |
| { |
| int r; |
| struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer; |
| |
| buffer->ptr = buffer->buf; |
| buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf); |
| buffer->processed = 0; |
| |
| r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len); |
| if (r) |
| goto out; |
| |
| while (buffer->len) { |
| r = kvm_pv_mmu_op_one(vcpu, buffer); |
| if (r < 0) |
| goto out; |
| if (r == 0) |
| break; |
| } |
| |
| r = 1; |
| out: |
| *ret = buffer->processed; |
| return r; |
| } |
| |
| #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); |
| hpa_t hpa = (hpa_t)gpa_to_pfn(vcpu, gpa) << PAGE_SHIFT; |
| |
| 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) |
| { |
| 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", |
| __func__, 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; |
| |
| gfn = unalias_gfn(vcpu->kvm, sp->gfn); |
| slot = gfn_to_memslot_unaliased(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", |
| __func__, 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 |