Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Kernel-based Virtual Machine driver for Linux |
| 3 | * |
| 4 | * This module enables machines with Intel VT-x extensions to run virtual |
| 5 | * machines without emulation or binary translation. |
| 6 | * |
| 7 | * MMU support |
| 8 | * |
| 9 | * Copyright (C) 2006 Qumranet, Inc. |
Nicolas Kaiser | 9611c18 | 2010-10-06 14:23:22 +0200 | [diff] [blame] | 10 | * Copyright 2010 Red Hat, Inc. and/or its affiliates. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 11 | * |
| 12 | * Authors: |
| 13 | * Yaniv Kamay <yaniv@qumranet.com> |
| 14 | * Avi Kivity <avi@qumranet.com> |
| 15 | * |
| 16 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 17 | * the COPYING file in the top-level directory. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | /* |
| 22 | * We need the mmu code to access both 32-bit and 64-bit guest ptes, |
| 23 | * so the code in this file is compiled twice, once per pte size. |
| 24 | */ |
| 25 | |
| 26 | #if PTTYPE == 64 |
| 27 | #define pt_element_t u64 |
| 28 | #define guest_walker guest_walker64 |
| 29 | #define FNAME(name) paging##64_##name |
| 30 | #define PT_BASE_ADDR_MASK PT64_BASE_ADDR_MASK |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 31 | #define PT_LVL_ADDR_MASK(lvl) PT64_LVL_ADDR_MASK(lvl) |
| 32 | #define PT_LVL_OFFSET_MASK(lvl) PT64_LVL_OFFSET_MASK(lvl) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 33 | #define PT_INDEX(addr, level) PT64_INDEX(addr, level) |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 34 | #define PT_LEVEL_BITS PT64_LEVEL_BITS |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 35 | #ifdef CONFIG_X86_64 |
| 36 | #define PT_MAX_FULL_LEVELS 4 |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 37 | #define CMPXCHG cmpxchg |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 38 | #else |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 39 | #define CMPXCHG cmpxchg64 |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 40 | #define PT_MAX_FULL_LEVELS 2 |
| 41 | #endif |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 42 | #elif PTTYPE == 32 |
| 43 | #define pt_element_t u32 |
| 44 | #define guest_walker guest_walker32 |
| 45 | #define FNAME(name) paging##32_##name |
| 46 | #define PT_BASE_ADDR_MASK PT32_BASE_ADDR_MASK |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 47 | #define PT_LVL_ADDR_MASK(lvl) PT32_LVL_ADDR_MASK(lvl) |
| 48 | #define PT_LVL_OFFSET_MASK(lvl) PT32_LVL_OFFSET_MASK(lvl) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 49 | #define PT_INDEX(addr, level) PT32_INDEX(addr, level) |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 50 | #define PT_LEVEL_BITS PT32_LEVEL_BITS |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 51 | #define PT_MAX_FULL_LEVELS 2 |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 52 | #define CMPXCHG cmpxchg |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 53 | #else |
| 54 | #error Invalid PTTYPE value |
| 55 | #endif |
| 56 | |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 57 | #define gpte_to_gfn_lvl FNAME(gpte_to_gfn_lvl) |
| 58 | #define gpte_to_gfn(pte) gpte_to_gfn_lvl((pte), PT_PAGE_TABLE_LEVEL) |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 59 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 60 | /* |
| 61 | * The guest_walker structure emulates the behavior of the hardware page |
| 62 | * table walker. |
| 63 | */ |
| 64 | struct guest_walker { |
| 65 | int level; |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 66 | unsigned max_level; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 67 | gfn_t table_gfn[PT_MAX_FULL_LEVELS]; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 68 | pt_element_t ptes[PT_MAX_FULL_LEVELS]; |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 69 | pt_element_t prefetch_ptes[PTE_PREFETCH_NUM]; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 70 | gpa_t pte_gpa[PT_MAX_FULL_LEVELS]; |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 71 | pt_element_t __user *ptep_user[PT_MAX_FULL_LEVELS]; |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 72 | unsigned pt_access; |
| 73 | unsigned pte_access; |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 74 | gfn_t gfn; |
Avi Kivity | 8c28d03 | 2010-11-22 17:53:27 +0200 | [diff] [blame] | 75 | struct x86_exception fault; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 76 | }; |
| 77 | |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 78 | static gfn_t gpte_to_gfn_lvl(pt_element_t gpte, int lvl) |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 79 | { |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 80 | return (gpte & PT_LVL_ADDR_MASK(lvl)) >> PAGE_SHIFT; |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 81 | } |
| 82 | |
Roedel, Joerg | a78484c | 2011-04-20 15:33:16 +0200 | [diff] [blame] | 83 | static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, |
Takuya Yoshikawa | c8cfbb5 | 2011-05-01 14:33:07 +0900 | [diff] [blame] | 84 | pt_element_t __user *ptep_user, unsigned index, |
| 85 | pt_element_t orig_pte, pt_element_t new_pte) |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 86 | { |
Takuya Yoshikawa | c8cfbb5 | 2011-05-01 14:33:07 +0900 | [diff] [blame] | 87 | int npages; |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 88 | pt_element_t ret; |
| 89 | pt_element_t *table; |
| 90 | struct page *page; |
| 91 | |
Takuya Yoshikawa | c8cfbb5 | 2011-05-01 14:33:07 +0900 | [diff] [blame] | 92 | npages = get_user_pages_fast((unsigned long)ptep_user, 1, 1, &page); |
| 93 | /* Check if the user is doing something meaningless. */ |
| 94 | if (unlikely(npages != 1)) |
Roedel, Joerg | a78484c | 2011-04-20 15:33:16 +0200 | [diff] [blame] | 95 | return -EFAULT; |
| 96 | |
Cong Wang | 8fd75e1 | 2011-11-25 23:14:17 +0800 | [diff] [blame] | 97 | table = kmap_atomic(page); |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 98 | ret = CMPXCHG(&table[index], orig_pte, new_pte); |
Cong Wang | 8fd75e1 | 2011-11-25 23:14:17 +0800 | [diff] [blame] | 99 | kunmap_atomic(table); |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 100 | |
| 101 | kvm_release_page_dirty(page); |
| 102 | |
| 103 | return (ret != orig_pte); |
| 104 | } |
| 105 | |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 106 | static int FNAME(update_accessed_dirty_bits)(struct kvm_vcpu *vcpu, |
| 107 | struct kvm_mmu *mmu, |
| 108 | struct guest_walker *walker, |
| 109 | int write_fault) |
| 110 | { |
| 111 | unsigned level, index; |
| 112 | pt_element_t pte, orig_pte; |
| 113 | pt_element_t __user *ptep_user; |
| 114 | gfn_t table_gfn; |
| 115 | int ret; |
| 116 | |
| 117 | for (level = walker->max_level; level >= walker->level; --level) { |
| 118 | pte = orig_pte = walker->ptes[level - 1]; |
| 119 | table_gfn = walker->table_gfn[level - 1]; |
| 120 | ptep_user = walker->ptep_user[level - 1]; |
| 121 | index = offset_in_page(ptep_user) / sizeof(pt_element_t); |
| 122 | if (!(pte & PT_ACCESSED_MASK)) { |
| 123 | trace_kvm_mmu_set_accessed_bit(table_gfn, index, sizeof(pte)); |
| 124 | pte |= PT_ACCESSED_MASK; |
| 125 | } |
| 126 | if (level == walker->level && write_fault && !is_dirty_gpte(pte)) { |
| 127 | trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte)); |
| 128 | pte |= PT_DIRTY_MASK; |
| 129 | } |
| 130 | if (pte == orig_pte) |
| 131 | continue; |
| 132 | |
| 133 | ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index, orig_pte, pte); |
| 134 | if (ret) |
| 135 | return ret; |
| 136 | |
| 137 | mark_page_dirty(vcpu->kvm, table_gfn); |
| 138 | walker->ptes[level] = pte; |
| 139 | } |
| 140 | return 0; |
| 141 | } |
| 142 | |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 143 | /* |
| 144 | * Fetch a guest pte for a guest virtual address |
| 145 | */ |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 146 | static int FNAME(walk_addr_generic)(struct guest_walker *walker, |
| 147 | struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 148 | gva_t addr, u32 access) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 149 | { |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 150 | int ret; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 151 | pt_element_t pte; |
Borislav Petkov | b723363 | 2011-05-30 22:11:17 +0200 | [diff] [blame] | 152 | pt_element_t __user *uninitialized_var(ptep_user); |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 153 | gfn_t table_gfn; |
Gleb Natapov | b0cfeb5 | 2013-01-08 10:49:00 +0200 | [diff] [blame] | 154 | unsigned index, pt_access, pte_access, accessed_dirty; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 155 | gpa_t pte_gpa; |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 156 | int offset; |
| 157 | const int write_fault = access & PFERR_WRITE_MASK; |
| 158 | const int user_fault = access & PFERR_USER_MASK; |
| 159 | const int fetch_fault = access & PFERR_FETCH_MASK; |
| 160 | u16 errcode = 0; |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 161 | gpa_t real_gpa; |
| 162 | gfn_t gfn; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 163 | |
Xiao Guangrong | 6fbc277 | 2012-06-20 16:00:00 +0800 | [diff] [blame] | 164 | trace_kvm_mmu_pagetable_walk(addr, access); |
Takuya Yoshikawa | 92c1c1e | 2011-07-01 01:36:07 +0900 | [diff] [blame] | 165 | retry_walk: |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 166 | walker->level = mmu->root_level; |
| 167 | pte = mmu->get_cr3(vcpu); |
| 168 | |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 169 | #if PTTYPE == 64 |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 170 | if (walker->level == PT32E_ROOT_LEVEL) { |
Avi Kivity | e4e517b | 2011-07-28 11:36:17 +0300 | [diff] [blame] | 171 | pte = mmu->get_pdptr(vcpu, (addr >> 30) & 3); |
Avi Kivity | 0742017 | 2009-07-06 12:21:32 +0300 | [diff] [blame] | 172 | trace_kvm_mmu_paging_element(pte, walker->level); |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 173 | if (!is_present_gpte(pte)) |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 174 | goto error; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 175 | --walker->level; |
| 176 | } |
| 177 | #endif |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 178 | walker->max_level = walker->level; |
Avi Kivity | a9058ec | 2006-12-29 16:49:37 -0800 | [diff] [blame] | 179 | ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) || |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 180 | (mmu->get_cr3(vcpu) & CR3_NONPAE_RESERVED_BITS) == 0); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 181 | |
Avi Kivity | b514c30 | 2012-09-16 15:03:02 +0300 | [diff] [blame] | 182 | accessed_dirty = PT_ACCESSED_MASK; |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 183 | pt_access = pte_access = ACC_ALL; |
| 184 | ++walker->level; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 185 | |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 186 | do { |
Takuya Yoshikawa | 6e2ca7d | 2011-04-22 00:34:44 +0900 | [diff] [blame] | 187 | gfn_t real_gfn; |
| 188 | unsigned long host_addr; |
| 189 | |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 190 | pt_access &= pte_access; |
| 191 | --walker->level; |
| 192 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 193 | index = PT_INDEX(addr, walker->level); |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 194 | |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 195 | table_gfn = gpte_to_gfn(pte); |
Joerg Roedel | 2329d46 | 2010-09-10 17:30:52 +0200 | [diff] [blame] | 196 | offset = index * sizeof(pt_element_t); |
| 197 | pte_gpa = gfn_to_gpa(table_gfn) + offset; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 198 | walker->table_gfn[walker->level - 1] = table_gfn; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 199 | walker->pte_gpa[walker->level - 1] = pte_gpa; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 200 | |
Takuya Yoshikawa | 6e2ca7d | 2011-04-22 00:34:44 +0900 | [diff] [blame] | 201 | real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn), |
| 202 | PFERR_USER_MASK|PFERR_WRITE_MASK); |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 203 | if (unlikely(real_gfn == UNMAPPED_GVA)) |
| 204 | goto error; |
Takuya Yoshikawa | 6e2ca7d | 2011-04-22 00:34:44 +0900 | [diff] [blame] | 205 | real_gfn = gpa_to_gfn(real_gfn); |
| 206 | |
| 207 | host_addr = gfn_to_hva(vcpu->kvm, real_gfn); |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 208 | if (unlikely(kvm_is_error_hva(host_addr))) |
| 209 | goto error; |
Takuya Yoshikawa | 6e2ca7d | 2011-04-22 00:34:44 +0900 | [diff] [blame] | 210 | |
| 211 | ptep_user = (pt_element_t __user *)((void *)host_addr + offset); |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 212 | if (unlikely(__copy_from_user(&pte, ptep_user, sizeof(pte)))) |
| 213 | goto error; |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 214 | walker->ptep_user[walker->level - 1] = ptep_user; |
Marcelo Tosatti | a6085fba | 2010-01-14 17:41:27 -0200 | [diff] [blame] | 215 | |
Avi Kivity | 0742017 | 2009-07-06 12:21:32 +0300 | [diff] [blame] | 216 | trace_kvm_mmu_paging_element(pte, walker->level); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 217 | |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 218 | if (unlikely(!is_present_gpte(pte))) |
| 219 | goto error; |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 220 | |
Avi Kivity | 781e074 | 2011-04-24 12:25:50 +0300 | [diff] [blame] | 221 | if (unlikely(is_rsvd_bits_set(&vcpu->arch.mmu, pte, |
| 222 | walker->level))) { |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 223 | errcode |= PFERR_RSVD_MASK | PFERR_PRESENT_MASK; |
| 224 | goto error; |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 225 | } |
Dong, Eddie | 82725b2 | 2009-03-30 16:21:08 +0800 | [diff] [blame] | 226 | |
Avi Kivity | b514c30 | 2012-09-16 15:03:02 +0300 | [diff] [blame] | 227 | accessed_dirty &= pte; |
Avi Kivity | 97d64b7 | 2012-09-12 14:52:00 +0300 | [diff] [blame] | 228 | pte_access = pt_access & gpte_access(vcpu, pte); |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 229 | |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 230 | walker->ptes[walker->level - 1] = pte; |
Avi Kivity | 6fd01b7 | 2012-09-12 20:46:56 +0300 | [diff] [blame] | 231 | } while (!is_last_gpte(mmu, walker->level, pte)); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 232 | |
Avi Kivity | 71331a1 | 2012-09-16 14:49:15 +0300 | [diff] [blame] | 233 | if (unlikely(permission_fault(mmu, pte_access, access))) { |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 234 | errcode |= PFERR_PRESENT_MASK; |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 235 | goto error; |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 236 | } |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 237 | |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 238 | gfn = gpte_to_gfn_lvl(pte, walker->level); |
| 239 | gfn += (addr & PT_LVL_OFFSET_MASK(walker->level)) >> PAGE_SHIFT; |
| 240 | |
| 241 | if (PTTYPE == 32 && walker->level == PT_DIRECTORY_LEVEL && is_cpuid_PSE36()) |
| 242 | gfn += pse36_gfn_delta(pte); |
| 243 | |
Avi Kivity | c542151 | 2012-09-19 19:33:48 +0300 | [diff] [blame] | 244 | real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access); |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 245 | if (real_gpa == UNMAPPED_GVA) |
| 246 | return 0; |
| 247 | |
| 248 | walker->gfn = real_gpa >> PAGE_SHIFT; |
| 249 | |
Avi Kivity | 8ea667f | 2012-09-12 13:44:53 +0300 | [diff] [blame] | 250 | if (!write_fault) |
| 251 | protect_clean_gpte(&pte_access, pte); |
Gleb Natapov | 908e7d7 | 2012-12-27 14:44:58 +0200 | [diff] [blame] | 252 | else |
| 253 | /* |
| 254 | * On a write fault, fold the dirty bit into accessed_dirty by |
| 255 | * shifting it one place right. |
| 256 | */ |
| 257 | accessed_dirty &= pte >> (PT_DIRTY_SHIFT - PT_ACCESSED_SHIFT); |
Avi Kivity | b514c30 | 2012-09-16 15:03:02 +0300 | [diff] [blame] | 258 | |
| 259 | if (unlikely(!accessed_dirty)) { |
| 260 | ret = FNAME(update_accessed_dirty_bits)(vcpu, mmu, walker, write_fault); |
| 261 | if (unlikely(ret < 0)) |
| 262 | goto error; |
| 263 | else if (ret) |
| 264 | goto retry_walk; |
| 265 | } |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 266 | |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 267 | walker->pt_access = pt_access; |
| 268 | walker->pte_access = pte_access; |
| 269 | pgprintk("%s: pte %llx pte_access %x pt_access %x\n", |
Gui Jianfeng | 518c5a0 | 2010-05-05 09:58:33 +0800 | [diff] [blame] | 270 | __func__, (u64)pte, pte_access, pt_access); |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 271 | return 1; |
| 272 | |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 273 | error: |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 274 | errcode |= write_fault | user_fault; |
Yang, Wei Y | e57d4a3 | 2011-06-03 11:14:16 +0800 | [diff] [blame] | 275 | if (fetch_fault && (mmu->nx || |
| 276 | kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))) |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 277 | errcode |= PFERR_FETCH_MASK; |
Joerg Roedel | 8df25a3 | 2010-09-10 17:30:46 +0200 | [diff] [blame] | 278 | |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 279 | walker->fault.vector = PF_VECTOR; |
| 280 | walker->fault.error_code_valid = true; |
| 281 | walker->fault.error_code = errcode; |
Avi Kivity | 6389ee9 | 2010-11-29 16:12:30 +0200 | [diff] [blame] | 282 | walker->fault.address = addr; |
| 283 | walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu; |
Joerg Roedel | 8df25a3 | 2010-09-10 17:30:46 +0200 | [diff] [blame] | 284 | |
Avi Kivity | 8c28d03 | 2010-11-22 17:53:27 +0200 | [diff] [blame] | 285 | trace_kvm_mmu_walker_error(walker->fault.error_code); |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 286 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 287 | } |
| 288 | |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 289 | static int FNAME(walk_addr)(struct guest_walker *walker, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 290 | struct kvm_vcpu *vcpu, gva_t addr, u32 access) |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 291 | { |
| 292 | return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.mmu, addr, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 293 | access); |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 294 | } |
| 295 | |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 296 | static int FNAME(walk_addr_nested)(struct guest_walker *walker, |
| 297 | struct kvm_vcpu *vcpu, gva_t addr, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 298 | u32 access) |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 299 | { |
| 300 | return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.nested_mmu, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 301 | addr, access); |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 302 | } |
| 303 | |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 304 | static bool |
| 305 | FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, |
| 306 | u64 *spte, pt_element_t gpte, bool no_dirty_log) |
| 307 | { |
| 308 | unsigned pte_access; |
| 309 | gfn_t gfn; |
| 310 | pfn_t pfn; |
| 311 | |
| 312 | if (prefetch_invalid_gpte(vcpu, sp, spte, gpte)) |
| 313 | return false; |
| 314 | |
| 315 | pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte); |
| 316 | |
| 317 | gfn = gpte_to_gfn(gpte); |
| 318 | pte_access = sp->role.access & gpte_access(vcpu, gpte); |
| 319 | protect_clean_gpte(&pte_access, gpte); |
| 320 | pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn, |
| 321 | no_dirty_log && (pte_access & ACC_WRITE_MASK)); |
Xiao Guangrong | 81c52c5 | 2012-10-16 20:10:59 +0800 | [diff] [blame] | 322 | if (is_error_pfn(pfn)) |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 323 | return false; |
| 324 | |
| 325 | /* |
| 326 | * we call mmu_set_spte() with host_writable = true because |
| 327 | * pte_prefetch_gfn_to_pfn always gets a writable pfn. |
| 328 | */ |
Xiao Guangrong | f761620 | 2013-02-05 15:27:27 +0800 | [diff] [blame^] | 329 | mmu_set_spte(vcpu, spte, pte_access, 0, NULL, PT_PAGE_TABLE_LEVEL, |
| 330 | gfn, pfn, true, true); |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 331 | |
| 332 | return true; |
| 333 | } |
| 334 | |
Xiao Guangrong | ac3cd03 | 2010-06-11 21:28:14 +0800 | [diff] [blame] | 335 | static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, |
Xiao Guangrong | 7c56252 | 2011-03-28 10:29:27 +0800 | [diff] [blame] | 336 | u64 *spte, const void *pte) |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 337 | { |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 338 | pt_element_t gpte = *(const pt_element_t *)pte; |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 339 | |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 340 | FNAME(prefetch_gpte)(vcpu, sp, spte, gpte, false); |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 341 | } |
| 342 | |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 343 | static bool FNAME(gpte_changed)(struct kvm_vcpu *vcpu, |
| 344 | struct guest_walker *gw, int level) |
| 345 | { |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 346 | pt_element_t curr_pte; |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 347 | gpa_t base_gpa, pte_gpa = gw->pte_gpa[level - 1]; |
| 348 | u64 mask; |
| 349 | int r, index; |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 350 | |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 351 | if (level == PT_PAGE_TABLE_LEVEL) { |
| 352 | mask = PTE_PREFETCH_NUM * sizeof(pt_element_t) - 1; |
| 353 | base_gpa = pte_gpa & ~mask; |
| 354 | index = (pte_gpa - base_gpa) / sizeof(pt_element_t); |
| 355 | |
| 356 | r = kvm_read_guest_atomic(vcpu->kvm, base_gpa, |
| 357 | gw->prefetch_ptes, sizeof(gw->prefetch_ptes)); |
| 358 | curr_pte = gw->prefetch_ptes[index]; |
| 359 | } else |
| 360 | r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 361 | &curr_pte, sizeof(curr_pte)); |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 362 | |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 363 | return r || curr_pte != gw->ptes[level - 1]; |
| 364 | } |
| 365 | |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 366 | static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, |
| 367 | u64 *sptep) |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 368 | { |
| 369 | struct kvm_mmu_page *sp; |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 370 | pt_element_t *gptep = gw->prefetch_ptes; |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 371 | u64 *spte; |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 372 | int i; |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 373 | |
| 374 | sp = page_header(__pa(sptep)); |
| 375 | |
| 376 | if (sp->role.level > PT_PAGE_TABLE_LEVEL) |
| 377 | return; |
| 378 | |
| 379 | if (sp->role.direct) |
| 380 | return __direct_pte_prefetch(vcpu, sp, sptep); |
| 381 | |
| 382 | i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 383 | spte = sp->spt + i; |
| 384 | |
| 385 | for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 386 | if (spte == sptep) |
| 387 | continue; |
| 388 | |
Xiao Guangrong | c370795 | 2011-07-12 03:28:04 +0800 | [diff] [blame] | 389 | if (is_shadow_present_pte(*spte)) |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 390 | continue; |
| 391 | |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 392 | if (!FNAME(prefetch_gpte)(vcpu, sp, spte, gptep[i], true)) |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 393 | break; |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 394 | } |
| 395 | } |
| 396 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 397 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 398 | * Fetch a shadow pte for a specific level in the paging hierarchy. |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 399 | * If the guest tries to write a write-protected page, we need to |
| 400 | * emulate this operation, return 1 to indicate this case. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 401 | */ |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 402 | static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, |
Avi Kivity | e7a04c9 | 2008-12-25 15:10:50 +0200 | [diff] [blame] | 403 | struct guest_walker *gw, |
Xiao Guangrong | c2288505 | 2013-01-08 14:36:04 +0800 | [diff] [blame] | 404 | int write_fault, int hlevel, |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 405 | pfn_t pfn, bool map_writable, bool prefault) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 406 | { |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 407 | struct kvm_mmu_page *sp = NULL; |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 408 | struct kvm_shadow_walk_iterator it; |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 409 | unsigned direct_access, access = gw->pt_access; |
| 410 | int top_level, emulate = 0; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 411 | |
Xiao Guangrong | b36c7a7 | 2011-07-12 03:25:19 +0800 | [diff] [blame] | 412 | direct_access = gw->pte_access; |
Xiao Guangrong | 84754cd | 2010-06-30 16:05:00 +0800 | [diff] [blame] | 413 | |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 414 | top_level = vcpu->arch.mmu.root_level; |
| 415 | if (top_level == PT32E_ROOT_LEVEL) |
| 416 | top_level = PT32_ROOT_LEVEL; |
| 417 | /* |
| 418 | * Verify that the top-level gpte is still there. Since the page |
| 419 | * is a root page, it is either write protected (and cannot be |
| 420 | * changed from now on) or it is invalid (in which case, we don't |
| 421 | * really care if it changes underneath us after this point). |
| 422 | */ |
| 423 | if (FNAME(gpte_changed)(vcpu, gw, top_level)) |
| 424 | goto out_gpte_changed; |
| 425 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 426 | for (shadow_walk_init(&it, vcpu, addr); |
| 427 | shadow_walk_okay(&it) && it.level > gw->level; |
| 428 | shadow_walk_next(&it)) { |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 429 | gfn_t table_gfn; |
| 430 | |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 431 | clear_sp_write_flooding_count(it.sptep); |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 432 | drop_large_spte(vcpu, it.sptep); |
Avi Kivity | e7a04c9 | 2008-12-25 15:10:50 +0200 | [diff] [blame] | 433 | |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 434 | sp = NULL; |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 435 | if (!is_shadow_present_pte(*it.sptep)) { |
| 436 | table_gfn = gw->table_gfn[it.level - 2]; |
| 437 | sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1, |
| 438 | false, access, it.sptep); |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 439 | } |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 440 | |
| 441 | /* |
| 442 | * Verify that the gpte in the page we've just write |
| 443 | * protected is still there. |
| 444 | */ |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 445 | if (FNAME(gpte_changed)(vcpu, gw, it.level - 1)) |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 446 | goto out_gpte_changed; |
Avi Kivity | e7a04c9 | 2008-12-25 15:10:50 +0200 | [diff] [blame] | 447 | |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 448 | if (sp) |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 449 | link_shadow_page(it.sptep, sp); |
Avi Kivity | e7a04c9 | 2008-12-25 15:10:50 +0200 | [diff] [blame] | 450 | } |
| 451 | |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 452 | for (; |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 453 | shadow_walk_okay(&it) && it.level > hlevel; |
| 454 | shadow_walk_next(&it)) { |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 455 | gfn_t direct_gfn; |
| 456 | |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 457 | clear_sp_write_flooding_count(it.sptep); |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 458 | validate_direct_spte(vcpu, it.sptep, direct_access); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 459 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 460 | drop_large_spte(vcpu, it.sptep); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 461 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 462 | if (is_shadow_present_pte(*it.sptep)) |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 463 | continue; |
| 464 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 465 | direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 466 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 467 | sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1, |
| 468 | true, direct_access, it.sptep); |
| 469 | link_shadow_page(it.sptep, sp); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 470 | } |
| 471 | |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 472 | clear_sp_write_flooding_count(it.sptep); |
Xiao Guangrong | f761620 | 2013-02-05 15:27:27 +0800 | [diff] [blame^] | 473 | mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault, &emulate, |
| 474 | it.level, gw->gfn, pfn, prefault, map_writable); |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 475 | FNAME(pte_prefetch)(vcpu, gw, it.sptep); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 476 | |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 477 | return emulate; |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 478 | |
| 479 | out_gpte_changed: |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 480 | if (sp) |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 481 | kvm_mmu_put_page(sp, it.sptep); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 482 | kvm_release_pfn_clean(pfn); |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 483 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 484 | } |
| 485 | |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 486 | /* |
| 487 | * To see whether the mapped gfn can write its page table in the current |
| 488 | * mapping. |
| 489 | * |
| 490 | * It is the helper function of FNAME(page_fault). When guest uses large page |
| 491 | * size to map the writable gfn which is used as current page table, we should |
| 492 | * force kvm to use small page size to map it because new shadow page will be |
| 493 | * created when kvm establishes shadow page table that stop kvm using large |
| 494 | * page size. Do it early can avoid unnecessary #PF and emulation. |
| 495 | * |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 496 | * @write_fault_to_shadow_pgtable will return true if the fault gfn is |
| 497 | * currently used as its page table. |
| 498 | * |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 499 | * Note: the PDPT page table is not checked for PAE-32 bit guest. It is ok |
| 500 | * since the PDPT is always shadowed, that means, we can not use large page |
| 501 | * size to map the gfn which is used as PDPT. |
| 502 | */ |
| 503 | static bool |
| 504 | FNAME(is_self_change_mapping)(struct kvm_vcpu *vcpu, |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 505 | struct guest_walker *walker, int user_fault, |
| 506 | bool *write_fault_to_shadow_pgtable) |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 507 | { |
| 508 | int level; |
| 509 | gfn_t mask = ~(KVM_PAGES_PER_HPAGE(walker->level) - 1); |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 510 | bool self_changed = false; |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 511 | |
| 512 | if (!(walker->pte_access & ACC_WRITE_MASK || |
| 513 | (!is_write_protection(vcpu) && !user_fault))) |
| 514 | return false; |
| 515 | |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 516 | for (level = walker->level; level <= walker->max_level; level++) { |
| 517 | gfn_t gfn = walker->gfn ^ walker->table_gfn[level - 1]; |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 518 | |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 519 | self_changed |= !(gfn & mask); |
| 520 | *write_fault_to_shadow_pgtable |= !gfn; |
| 521 | } |
| 522 | |
| 523 | return self_changed; |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 524 | } |
| 525 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 526 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 527 | * Page fault handler. There are several causes for a page fault: |
| 528 | * - there is no shadow pte for the guest pte |
| 529 | * - write access through a shadow pte marked read only so that we can set |
| 530 | * the dirty bit |
| 531 | * - write access to a shadow pte marked read only so we can update the page |
| 532 | * dirty bitmap, when userspace requests it |
| 533 | * - mmio access; in this case we will never install a present shadow pte |
| 534 | * - normal guest page fault due to the guest pte marked not present, not |
| 535 | * writable, or not executable |
| 536 | * |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 537 | * Returns: 1 if we need to emulate the instruction, 0 otherwise, or |
| 538 | * a negative value on error. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 539 | */ |
Gleb Natapov | 56028d0 | 2010-10-17 18:13:42 +0200 | [diff] [blame] | 540 | static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, |
Xiao Guangrong | 78b2c54 | 2010-12-07 10:48:06 +0800 | [diff] [blame] | 541 | bool prefault) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 542 | { |
| 543 | int write_fault = error_code & PFERR_WRITE_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 544 | int user_fault = error_code & PFERR_USER_MASK; |
| 545 | struct guest_walker walker; |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 546 | int r; |
Anthony Liguori | 35149e2 | 2008-04-02 14:46:56 -0500 | [diff] [blame] | 547 | pfn_t pfn; |
Joerg Roedel | 7e4e405 | 2009-07-27 16:30:46 +0200 | [diff] [blame] | 548 | int level = PT_PAGE_TABLE_LEVEL; |
Andrea Arcangeli | 936a5fe | 2011-01-13 15:46:48 -0800 | [diff] [blame] | 549 | int force_pt_level; |
Andrea Arcangeli | e930bff | 2008-07-25 16:24:52 +0200 | [diff] [blame] | 550 | unsigned long mmu_seq; |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 551 | bool map_writable, is_self_change_mapping; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 552 | |
Harvey Harrison | b8688d5 | 2008-03-03 12:59:56 -0800 | [diff] [blame] | 553 | pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 554 | |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 555 | if (unlikely(error_code & PFERR_RSVD_MASK)) |
| 556 | return handle_mmio_page_fault(vcpu, addr, error_code, |
| 557 | mmu_is_nested(vcpu)); |
| 558 | |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 559 | r = mmu_topup_memory_caches(vcpu); |
| 560 | if (r) |
| 561 | return r; |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 562 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 563 | /* |
Eddie Dong | a8b876b | 2009-03-26 15:28:40 +0800 | [diff] [blame] | 564 | * Look up the guest pte for the faulting address. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 565 | */ |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 566 | r = FNAME(walk_addr)(&walker, vcpu, addr, error_code); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 567 | |
| 568 | /* |
| 569 | * The page is not mapped by the guest. Let the guest handle it. |
| 570 | */ |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 571 | if (!r) { |
Harvey Harrison | b8688d5 | 2008-03-03 12:59:56 -0800 | [diff] [blame] | 572 | pgprintk("%s: guest page fault\n", __func__); |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 573 | if (!prefault) |
Xiao Guangrong | fb67e14 | 2010-12-07 10:35:25 +0800 | [diff] [blame] | 574 | inject_page_fault(vcpu, &walker.fault); |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 575 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 576 | return 0; |
| 577 | } |
| 578 | |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 579 | vcpu->arch.write_fault_to_shadow_pgtable = false; |
| 580 | |
| 581 | is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu, |
| 582 | &walker, user_fault, &vcpu->arch.write_fault_to_shadow_pgtable); |
| 583 | |
Andrea Arcangeli | 936a5fe | 2011-01-13 15:46:48 -0800 | [diff] [blame] | 584 | if (walker.level >= PT_DIRECTORY_LEVEL) |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 585 | force_pt_level = mapping_level_dirty_bitmap(vcpu, walker.gfn) |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 586 | || is_self_change_mapping; |
Andrea Arcangeli | 936a5fe | 2011-01-13 15:46:48 -0800 | [diff] [blame] | 587 | else |
| 588 | force_pt_level = 1; |
| 589 | if (!force_pt_level) { |
Joerg Roedel | 7e4e405 | 2009-07-27 16:30:46 +0200 | [diff] [blame] | 590 | level = min(walker.level, mapping_level(vcpu, walker.gfn)); |
| 591 | walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); |
Marcelo Tosatti | 05da455 | 2008-02-23 11:44:30 -0300 | [diff] [blame] | 592 | } |
Joerg Roedel | 7e4e405 | 2009-07-27 16:30:46 +0200 | [diff] [blame] | 593 | |
Andrea Arcangeli | e930bff | 2008-07-25 16:24:52 +0200 | [diff] [blame] | 594 | mmu_seq = vcpu->kvm->mmu_notifier_seq; |
Marcelo Tosatti | 4c2155c | 2008-09-16 20:54:47 -0300 | [diff] [blame] | 595 | smp_rmb(); |
Gleb Natapov | af585b9 | 2010-10-14 11:22:46 +0200 | [diff] [blame] | 596 | |
Xiao Guangrong | 78b2c54 | 2010-12-07 10:48:06 +0800 | [diff] [blame] | 597 | if (try_async_pf(vcpu, prefault, walker.gfn, addr, &pfn, write_fault, |
Marcelo Tosatti | 612819c | 2010-10-22 14:18:18 -0200 | [diff] [blame] | 598 | &map_writable)) |
Gleb Natapov | af585b9 | 2010-10-14 11:22:46 +0200 | [diff] [blame] | 599 | return 0; |
Avi Kivity | d7824ff | 2007-12-30 12:29:05 +0200 | [diff] [blame] | 600 | |
Xiao Guangrong | d7c5520 | 2011-07-12 03:29:38 +0800 | [diff] [blame] | 601 | if (handle_abnormal_pfn(vcpu, mmu_is_nested(vcpu) ? 0 : addr, |
| 602 | walker.gfn, pfn, walker.pte_access, &r)) |
| 603 | return r; |
| 604 | |
Xiao Guangrong | c2288505 | 2013-01-08 14:36:04 +0800 | [diff] [blame] | 605 | /* |
| 606 | * Do not change pte_access if the pfn is a mmio page, otherwise |
| 607 | * we will cache the incorrect access into mmio spte. |
| 608 | */ |
| 609 | if (write_fault && !(walker.pte_access & ACC_WRITE_MASK) && |
| 610 | !is_write_protection(vcpu) && !user_fault && |
| 611 | !is_noslot_pfn(pfn)) { |
| 612 | walker.pte_access |= ACC_WRITE_MASK; |
| 613 | walker.pte_access &= ~ACC_USER_MASK; |
| 614 | |
| 615 | /* |
| 616 | * If we converted a user page to a kernel page, |
| 617 | * so that the kernel can write to it when cr0.wp=0, |
| 618 | * then we should prevent the kernel from executing it |
| 619 | * if SMEP is enabled. |
| 620 | */ |
| 621 | if (kvm_read_cr4_bits(vcpu, X86_CR4_SMEP)) |
| 622 | walker.pte_access &= ~ACC_EXEC_MASK; |
| 623 | } |
| 624 | |
Marcelo Tosatti | aaee2c9 | 2007-12-20 19:18:26 -0500 | [diff] [blame] | 625 | spin_lock(&vcpu->kvm->mmu_lock); |
Christoffer Dall | 8ca40a7 | 2012-10-14 23:10:18 -0400 | [diff] [blame] | 626 | if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) |
Andrea Arcangeli | e930bff | 2008-07-25 16:24:52 +0200 | [diff] [blame] | 627 | goto out_unlock; |
Xiao Guangrong | bc32ce2 | 2010-08-28 19:22:46 +0800 | [diff] [blame] | 628 | |
Xiao Guangrong | 0375f7f | 2011-11-28 20:41:00 +0800 | [diff] [blame] | 629 | kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT); |
Avi Kivity | eb787d1 | 2007-12-31 15:27:49 +0200 | [diff] [blame] | 630 | kvm_mmu_free_some_pages(vcpu); |
Andrea Arcangeli | 936a5fe | 2011-01-13 15:46:48 -0800 | [diff] [blame] | 631 | if (!force_pt_level) |
| 632 | transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level); |
Xiao Guangrong | c2288505 | 2013-01-08 14:36:04 +0800 | [diff] [blame] | 633 | r = FNAME(fetch)(vcpu, addr, &walker, write_fault, |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 634 | level, pfn, map_writable, prefault); |
Avi Kivity | 1165f5f | 2007-04-19 17:27:43 +0300 | [diff] [blame] | 635 | ++vcpu->stat.pf_fixed; |
Xiao Guangrong | 0375f7f | 2011-11-28 20:41:00 +0800 | [diff] [blame] | 636 | kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT); |
Marcelo Tosatti | aaee2c9 | 2007-12-20 19:18:26 -0500 | [diff] [blame] | 637 | spin_unlock(&vcpu->kvm->mmu_lock); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 638 | |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 639 | return r; |
Andrea Arcangeli | e930bff | 2008-07-25 16:24:52 +0200 | [diff] [blame] | 640 | |
| 641 | out_unlock: |
| 642 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 643 | kvm_release_pfn_clean(pfn); |
| 644 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 645 | } |
| 646 | |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 647 | static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp) |
| 648 | { |
| 649 | int offset = 0; |
| 650 | |
Davidlohr Bueso | f71fa31 | 2012-04-18 12:24:29 +0200 | [diff] [blame] | 651 | WARN_ON(sp->role.level != PT_PAGE_TABLE_LEVEL); |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 652 | |
| 653 | if (PTTYPE == 32) |
| 654 | offset = sp->role.quadrant << PT64_LEVEL_BITS; |
| 655 | |
| 656 | return gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t); |
| 657 | } |
| 658 | |
Marcelo Tosatti | a705289 | 2008-09-23 13:18:35 -0300 | [diff] [blame] | 659 | static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) |
| 660 | { |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 661 | struct kvm_shadow_walk_iterator iterator; |
Xiao Guangrong | f78978a | 2010-05-15 18:53:35 +0800 | [diff] [blame] | 662 | struct kvm_mmu_page *sp; |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 663 | int level; |
| 664 | u64 *sptep; |
Marcelo Tosatti | a705289 | 2008-09-23 13:18:35 -0300 | [diff] [blame] | 665 | |
Xiao Guangrong | bebb106 | 2011-07-12 03:23:20 +0800 | [diff] [blame] | 666 | vcpu_clear_mmio_info(vcpu, gva); |
| 667 | |
Xiao Guangrong | f57f2ef | 2011-09-22 16:56:39 +0800 | [diff] [blame] | 668 | /* |
| 669 | * No need to check return value here, rmap_can_add() can |
| 670 | * help us to skip pte prefetch later. |
| 671 | */ |
| 672 | mmu_topup_memory_caches(vcpu); |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 673 | |
Xiao Guangrong | f57f2ef | 2011-09-22 16:56:39 +0800 | [diff] [blame] | 674 | spin_lock(&vcpu->kvm->mmu_lock); |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 675 | for_each_shadow_entry(vcpu, gva, iterator) { |
| 676 | level = iterator.level; |
| 677 | sptep = iterator.sptep; |
| 678 | |
Xiao Guangrong | f78978a | 2010-05-15 18:53:35 +0800 | [diff] [blame] | 679 | sp = page_header(__pa(sptep)); |
Xiao Guangrong | 884a0ff | 2010-04-28 11:55:15 +0800 | [diff] [blame] | 680 | if (is_last_spte(*sptep, level)) { |
Xiao Guangrong | f57f2ef | 2011-09-22 16:56:39 +0800 | [diff] [blame] | 681 | pt_element_t gpte; |
| 682 | gpa_t pte_gpa; |
| 683 | |
Xiao Guangrong | f78978a | 2010-05-15 18:53:35 +0800 | [diff] [blame] | 684 | if (!sp->unsync) |
| 685 | break; |
| 686 | |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 687 | pte_gpa = FNAME(get_level1_sp_gpa)(sp); |
Avi Kivity | 08e850c | 2010-03-15 13:59:57 +0200 | [diff] [blame] | 688 | pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t); |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 689 | |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 690 | if (mmu_page_zap_pte(vcpu->kvm, sp, sptep)) |
| 691 | kvm_flush_remote_tlbs(vcpu->kvm); |
Xiao Guangrong | f57f2ef | 2011-09-22 16:56:39 +0800 | [diff] [blame] | 692 | |
| 693 | if (!rmap_can_add(vcpu)) |
| 694 | break; |
| 695 | |
| 696 | if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, |
| 697 | sizeof(pt_element_t))) |
| 698 | break; |
| 699 | |
| 700 | FNAME(update_pte)(vcpu, sp, sptep, &gpte); |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 701 | } |
| 702 | |
Xiao Guangrong | f78978a | 2010-05-15 18:53:35 +0800 | [diff] [blame] | 703 | if (!is_shadow_present_pte(*sptep) || !sp->unsync_children) |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 704 | break; |
| 705 | } |
Marcelo Tosatti | ad218f8 | 2008-12-01 22:32:05 -0200 | [diff] [blame] | 706 | spin_unlock(&vcpu->kvm->mmu_lock); |
Marcelo Tosatti | a705289 | 2008-09-23 13:18:35 -0300 | [diff] [blame] | 707 | } |
| 708 | |
Gleb Natapov | 1871c60 | 2010-02-10 14:21:32 +0200 | [diff] [blame] | 709 | static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access, |
Avi Kivity | ab9ae31 | 2010-11-22 17:53:26 +0200 | [diff] [blame] | 710 | struct x86_exception *exception) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 711 | { |
| 712 | struct guest_walker walker; |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 713 | gpa_t gpa = UNMAPPED_GVA; |
| 714 | int r; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 715 | |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 716 | r = FNAME(walk_addr)(&walker, vcpu, vaddr, access); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 717 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 718 | if (r) { |
Avi Kivity | 1755fbc | 2007-11-21 14:44:45 +0200 | [diff] [blame] | 719 | gpa = gfn_to_gpa(walker.gfn); |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 720 | gpa |= vaddr & ~PAGE_MASK; |
Avi Kivity | 8c28d03 | 2010-11-22 17:53:27 +0200 | [diff] [blame] | 721 | } else if (exception) |
| 722 | *exception = walker.fault; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 723 | |
| 724 | return gpa; |
| 725 | } |
| 726 | |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 727 | static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gva_t vaddr, |
Avi Kivity | ab9ae31 | 2010-11-22 17:53:26 +0200 | [diff] [blame] | 728 | u32 access, |
| 729 | struct x86_exception *exception) |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 730 | { |
| 731 | struct guest_walker walker; |
| 732 | gpa_t gpa = UNMAPPED_GVA; |
| 733 | int r; |
| 734 | |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 735 | r = FNAME(walk_addr_nested)(&walker, vcpu, vaddr, access); |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 736 | |
| 737 | if (r) { |
| 738 | gpa = gfn_to_gpa(walker.gfn); |
| 739 | gpa |= vaddr & ~PAGE_MASK; |
Avi Kivity | 8c28d03 | 2010-11-22 17:53:27 +0200 | [diff] [blame] | 740 | } else if (exception) |
| 741 | *exception = walker.fault; |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 742 | |
| 743 | return gpa; |
| 744 | } |
| 745 | |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 746 | /* |
| 747 | * Using the cached information from sp->gfns is safe because: |
| 748 | * - The spte has a reference to the struct page, so the pfn for a given gfn |
| 749 | * can't change unless all sptes pointing to it are nuked first. |
Xiao Guangrong | a4ee1ca | 2010-11-23 11:13:00 +0800 | [diff] [blame] | 750 | * |
| 751 | * Note: |
| 752 | * We should flush all tlbs if spte is dropped even though guest is |
| 753 | * responsible for it. Since if we don't, kvm_mmu_notifier_invalidate_page |
| 754 | * and kvm_mmu_notifier_invalidate_range_start detect the mapping page isn't |
| 755 | * used by guest then tlbs are not flushed, so guest is allowed to access the |
| 756 | * freed pages. |
| 757 | * And we increase kvm->tlbs_dirty to delay tlbs flush in this case. |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 758 | */ |
Xiao Guangrong | a4a8e6f | 2010-11-19 17:04:03 +0800 | [diff] [blame] | 759 | static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 760 | { |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 761 | int i, nr_present = 0; |
Lai Jiangshan | 9bdbba1 | 2010-11-19 17:03:22 +0800 | [diff] [blame] | 762 | bool host_writable; |
Gui Jianfeng | 51fb60d | 2010-04-16 17:16:40 +0800 | [diff] [blame] | 763 | gpa_t first_pte_gpa; |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 764 | |
Lai Jiangshan | 2032a93 | 2010-05-26 16:49:59 +0800 | [diff] [blame] | 765 | /* direct kvm_mmu_page can not be unsync. */ |
| 766 | BUG_ON(sp->role.direct); |
| 767 | |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 768 | first_pte_gpa = FNAME(get_level1_sp_gpa)(sp); |
Gui Jianfeng | 51fb60d | 2010-04-16 17:16:40 +0800 | [diff] [blame] | 769 | |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 770 | for (i = 0; i < PT64_ENT_PER_PAGE; i++) { |
| 771 | unsigned pte_access; |
| 772 | pt_element_t gpte; |
| 773 | gpa_t pte_gpa; |
Xiao Guangrong | f55c3f4 | 2010-05-13 10:08:08 +0800 | [diff] [blame] | 774 | gfn_t gfn; |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 775 | |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 776 | if (!sp->spt[i]) |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 777 | continue; |
| 778 | |
Gui Jianfeng | 51fb60d | 2010-04-16 17:16:40 +0800 | [diff] [blame] | 779 | pte_gpa = first_pte_gpa + i * sizeof(pt_element_t); |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 780 | |
| 781 | if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, |
| 782 | sizeof(pt_element_t))) |
| 783 | return -EINVAL; |
| 784 | |
Xiao Guangrong | a052b42 | 2012-10-16 20:09:36 +0800 | [diff] [blame] | 785 | if (prefetch_invalid_gpte(vcpu, sp, &sp->spt[i], gpte)) { |
Xiao Guangrong | a4ee1ca | 2010-11-23 11:13:00 +0800 | [diff] [blame] | 786 | vcpu->kvm->tlbs_dirty++; |
Xiao Guangrong | 407c61c | 2010-11-23 11:08:42 +0800 | [diff] [blame] | 787 | continue; |
| 788 | } |
| 789 | |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 790 | gfn = gpte_to_gfn(gpte); |
| 791 | pte_access = sp->role.access; |
Avi Kivity | 3d34ade | 2012-09-12 14:03:28 +0300 | [diff] [blame] | 792 | pte_access &= gpte_access(vcpu, gpte); |
Avi Kivity | 8ea667f | 2012-09-12 13:44:53 +0300 | [diff] [blame] | 793 | protect_clean_gpte(&pte_access, gpte); |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 794 | |
| 795 | if (sync_mmio_spte(&sp->spt[i], gfn, pte_access, &nr_present)) |
| 796 | continue; |
| 797 | |
Xiao Guangrong | 407c61c | 2010-11-23 11:08:42 +0800 | [diff] [blame] | 798 | if (gfn != sp->gfns[i]) { |
Xiao Guangrong | c370795 | 2011-07-12 03:28:04 +0800 | [diff] [blame] | 799 | drop_spte(vcpu->kvm, &sp->spt[i]); |
Xiao Guangrong | a4ee1ca | 2010-11-23 11:13:00 +0800 | [diff] [blame] | 800 | vcpu->kvm->tlbs_dirty++; |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 801 | continue; |
| 802 | } |
| 803 | |
| 804 | nr_present++; |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 805 | |
Xiao Guangrong | f8e453b | 2010-12-23 16:09:29 +0800 | [diff] [blame] | 806 | host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE; |
| 807 | |
Xiao Guangrong | c2288505 | 2013-01-08 14:36:04 +0800 | [diff] [blame] | 808 | set_spte(vcpu, &sp->spt[i], pte_access, |
Xiao Guangrong | 640d9b0 | 2011-07-12 03:24:39 +0800 | [diff] [blame] | 809 | PT_PAGE_TABLE_LEVEL, gfn, |
Izik Eidus | 1403283 | 2009-09-23 21:47:17 +0300 | [diff] [blame] | 810 | spte_to_pfn(sp->spt[i]), true, false, |
Lai Jiangshan | 9bdbba1 | 2010-11-19 17:03:22 +0800 | [diff] [blame] | 811 | host_writable); |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 812 | } |
| 813 | |
| 814 | return !nr_present; |
| 815 | } |
| 816 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 817 | #undef pt_element_t |
| 818 | #undef guest_walker |
| 819 | #undef FNAME |
| 820 | #undef PT_BASE_ADDR_MASK |
| 821 | #undef PT_INDEX |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 822 | #undef PT_LVL_ADDR_MASK |
| 823 | #undef PT_LVL_OFFSET_MASK |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 824 | #undef PT_LEVEL_BITS |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 825 | #undef PT_MAX_FULL_LEVELS |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 826 | #undef gpte_to_gfn |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 827 | #undef gpte_to_gfn_lvl |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 828 | #undef CMPXCHG |