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. |
| 10 | * |
| 11 | * Authors: |
| 12 | * Yaniv Kamay <yaniv@qumranet.com> |
| 13 | * Avi Kivity <avi@qumranet.com> |
| 14 | * |
| 15 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 16 | * the COPYING file in the top-level directory. |
| 17 | * |
| 18 | */ |
| 19 | |
| 20 | /* |
| 21 | * We need the mmu code to access both 32-bit and 64-bit guest ptes, |
| 22 | * so the code in this file is compiled twice, once per pte size. |
| 23 | */ |
| 24 | |
| 25 | #if PTTYPE == 64 |
| 26 | #define pt_element_t u64 |
| 27 | #define guest_walker guest_walker64 |
| 28 | #define FNAME(name) paging##64_##name |
| 29 | #define PT_BASE_ADDR_MASK PT64_BASE_ADDR_MASK |
| 30 | #define PT_DIR_BASE_ADDR_MASK PT64_DIR_BASE_ADDR_MASK |
| 31 | #define PT_INDEX(addr, level) PT64_INDEX(addr, level) |
| 32 | #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) |
| 33 | #define PT_LEVEL_MASK(level) PT64_LEVEL_MASK(level) |
| 34 | #define PT_PTE_COPY_MASK PT64_PTE_COPY_MASK |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 35 | #ifdef CONFIG_X86_64 |
| 36 | #define PT_MAX_FULL_LEVELS 4 |
| 37 | #else |
| 38 | #define PT_MAX_FULL_LEVELS 2 |
| 39 | #endif |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 40 | #elif PTTYPE == 32 |
| 41 | #define pt_element_t u32 |
| 42 | #define guest_walker guest_walker32 |
| 43 | #define FNAME(name) paging##32_##name |
| 44 | #define PT_BASE_ADDR_MASK PT32_BASE_ADDR_MASK |
| 45 | #define PT_DIR_BASE_ADDR_MASK PT32_DIR_BASE_ADDR_MASK |
| 46 | #define PT_INDEX(addr, level) PT32_INDEX(addr, level) |
| 47 | #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) |
| 48 | #define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level) |
| 49 | #define PT_PTE_COPY_MASK PT32_PTE_COPY_MASK |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 50 | #define PT_MAX_FULL_LEVELS 2 |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 51 | #else |
| 52 | #error Invalid PTTYPE value |
| 53 | #endif |
| 54 | |
| 55 | /* |
| 56 | * The guest_walker structure emulates the behavior of the hardware page |
| 57 | * table walker. |
| 58 | */ |
| 59 | struct guest_walker { |
| 60 | int level; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 61 | gfn_t table_gfn[PT_MAX_FULL_LEVELS]; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 62 | pt_element_t *table; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 63 | pt_element_t *ptep; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 64 | pt_element_t inherited_ar; |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 65 | gfn_t gfn; |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 66 | u32 error_code; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 67 | }; |
| 68 | |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 69 | /* |
| 70 | * Fetch a guest pte for a guest virtual address |
| 71 | */ |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 72 | static int FNAME(walk_addr)(struct guest_walker *walker, |
| 73 | struct kvm_vcpu *vcpu, gva_t addr, |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 74 | int write_fault, int user_fault, int fetch_fault) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 75 | { |
| 76 | hpa_t hpa; |
| 77 | struct kvm_memory_slot *slot; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 78 | pt_element_t *ptep; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 79 | pt_element_t root; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 80 | gfn_t table_gfn; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 81 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 82 | pgprintk("%s: addr %lx\n", __FUNCTION__, addr); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 83 | walker->level = vcpu->mmu.root_level; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 84 | walker->table = NULL; |
| 85 | root = vcpu->cr3; |
| 86 | #if PTTYPE == 64 |
| 87 | if (!is_long_mode(vcpu)) { |
| 88 | walker->ptep = &vcpu->pdptrs[(addr >> 30) & 3]; |
| 89 | root = *walker->ptep; |
| 90 | if (!(root & PT_PRESENT_MASK)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 91 | goto not_present; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 92 | --walker->level; |
| 93 | } |
| 94 | #endif |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 95 | table_gfn = (root & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| 96 | walker->table_gfn[walker->level - 1] = table_gfn; |
| 97 | pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__, |
| 98 | walker->level - 1, table_gfn); |
| 99 | slot = gfn_to_memslot(vcpu->kvm, table_gfn); |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 100 | hpa = safe_gpa_to_hpa(vcpu, root & PT64_BASE_ADDR_MASK); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 101 | walker->table = kmap_atomic(pfn_to_page(hpa >> PAGE_SHIFT), KM_USER0); |
| 102 | |
Avi Kivity | a9058ec | 2006-12-29 16:49:37 -0800 | [diff] [blame] | 103 | ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) || |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 104 | (vcpu->cr3 & ~(PAGE_MASK | CR3_FLAGS_MASK)) == 0); |
| 105 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 106 | walker->inherited_ar = PT_USER_MASK | PT_WRITABLE_MASK; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 107 | |
| 108 | for (;;) { |
| 109 | int index = PT_INDEX(addr, walker->level); |
| 110 | hpa_t paddr; |
| 111 | |
| 112 | ptep = &walker->table[index]; |
| 113 | ASSERT(((unsigned long)walker->table & PAGE_MASK) == |
| 114 | ((unsigned long)ptep & PAGE_MASK)); |
| 115 | |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 116 | if (!is_present_pte(*ptep)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 117 | goto not_present; |
| 118 | |
| 119 | if (write_fault && !is_writeble_pte(*ptep)) |
| 120 | if (user_fault || is_write_protection(vcpu)) |
| 121 | goto access_error; |
| 122 | |
| 123 | if (user_fault && !(*ptep & PT_USER_MASK)) |
| 124 | goto access_error; |
| 125 | |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 126 | #if PTTYPE == 64 |
| 127 | if (fetch_fault && is_nx(vcpu) && (*ptep & PT64_NX_MASK)) |
| 128 | goto access_error; |
| 129 | #endif |
| 130 | |
Avi Kivity | bf3f8e8 | 2007-02-19 14:37:46 +0200 | [diff] [blame] | 131 | if (!(*ptep & PT_ACCESSED_MASK)) { |
| 132 | mark_page_dirty(vcpu->kvm, table_gfn); |
| 133 | *ptep |= PT_ACCESSED_MASK; |
| 134 | } |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 135 | |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 136 | if (walker->level == PT_PAGE_TABLE_LEVEL) { |
| 137 | walker->gfn = (*ptep & PT_BASE_ADDR_MASK) |
| 138 | >> PAGE_SHIFT; |
| 139 | break; |
| 140 | } |
| 141 | |
| 142 | if (walker->level == PT_DIRECTORY_LEVEL |
| 143 | && (*ptep & PT_PAGE_SIZE_MASK) |
| 144 | && (PTTYPE == 64 || is_pse(vcpu))) { |
| 145 | walker->gfn = (*ptep & PT_DIR_BASE_ADDR_MASK) |
| 146 | >> PAGE_SHIFT; |
| 147 | walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL); |
| 148 | break; |
| 149 | } |
| 150 | |
Avi Kivity | ca5aac1 | 2007-03-20 14:29:06 +0200 | [diff] [blame] | 151 | walker->inherited_ar &= walker->table[index]; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 152 | table_gfn = (*ptep & PT_BASE_ADDR_MASK) >> PAGE_SHIFT; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 153 | paddr = safe_gpa_to_hpa(vcpu, *ptep & PT_BASE_ADDR_MASK); |
| 154 | kunmap_atomic(walker->table, KM_USER0); |
| 155 | walker->table = kmap_atomic(pfn_to_page(paddr >> PAGE_SHIFT), |
| 156 | KM_USER0); |
| 157 | --walker->level; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 158 | walker->table_gfn[walker->level - 1 ] = table_gfn; |
| 159 | pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__, |
| 160 | walker->level - 1, table_gfn); |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 161 | } |
| 162 | walker->ptep = ptep; |
Avi Kivity | 374cbac | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 163 | pgprintk("%s: pte %llx\n", __FUNCTION__, (u64)*ptep); |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 164 | return 1; |
| 165 | |
| 166 | not_present: |
| 167 | walker->error_code = 0; |
| 168 | goto err; |
| 169 | |
| 170 | access_error: |
| 171 | walker->error_code = PFERR_PRESENT_MASK; |
| 172 | |
| 173 | err: |
| 174 | if (write_fault) |
| 175 | walker->error_code |= PFERR_WRITE_MASK; |
| 176 | if (user_fault) |
| 177 | walker->error_code |= PFERR_USER_MASK; |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 178 | if (fetch_fault) |
| 179 | walker->error_code |= PFERR_FETCH_MASK; |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 180 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 181 | } |
| 182 | |
| 183 | static void FNAME(release_walker)(struct guest_walker *walker) |
| 184 | { |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 185 | if (walker->table) |
| 186 | kunmap_atomic(walker->table, KM_USER0); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 187 | } |
| 188 | |
Avi Kivity | bf3f8e8 | 2007-02-19 14:37:46 +0200 | [diff] [blame] | 189 | static void FNAME(mark_pagetable_dirty)(struct kvm *kvm, |
| 190 | struct guest_walker *walker) |
| 191 | { |
| 192 | mark_page_dirty(kvm, walker->table_gfn[walker->level - 1]); |
| 193 | } |
| 194 | |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 195 | static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu, |
| 196 | u64 *shadow_pte, |
| 197 | gpa_t gaddr, |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 198 | pt_element_t *gpte, |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 199 | u64 access_bits, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 200 | int user_fault, |
Avi Kivity | 63b1ad2 | 2007-05-31 11:56:54 +0300 | [diff] [blame] | 201 | int write_fault, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 202 | int *ptwrite, |
| 203 | struct guest_walker *walker, |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 204 | gfn_t gfn) |
| 205 | { |
| 206 | hpa_t paddr; |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 207 | int dirty = *gpte & PT_DIRTY_MASK; |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 208 | int was_rmapped = is_rmap_pte(*shadow_pte); |
| 209 | |
| 210 | pgprintk("%s: spte %llx gpte %llx access %llx write_fault %d" |
| 211 | " user_fault %d gfn %lx\n", |
| 212 | __FUNCTION__, *shadow_pte, (u64)*gpte, access_bits, |
| 213 | write_fault, user_fault, gfn); |
| 214 | |
| 215 | if (write_fault && !dirty) { |
| 216 | *gpte |= PT_DIRTY_MASK; |
| 217 | dirty = 1; |
| 218 | FNAME(mark_pagetable_dirty)(vcpu->kvm, walker); |
| 219 | } |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 220 | |
| 221 | *shadow_pte |= access_bits << PT_SHADOW_BITS_OFFSET; |
| 222 | if (!dirty) |
| 223 | access_bits &= ~PT_WRITABLE_MASK; |
| 224 | |
| 225 | paddr = gpa_to_hpa(vcpu, gaddr & PT64_BASE_ADDR_MASK); |
| 226 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 227 | *shadow_pte |= PT_PRESENT_MASK; |
| 228 | if (access_bits & PT_USER_MASK) |
| 229 | *shadow_pte |= PT_USER_MASK; |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 230 | |
| 231 | if (is_error_hpa(paddr)) { |
| 232 | *shadow_pte |= gaddr; |
| 233 | *shadow_pte |= PT_SHADOW_IO_MARK; |
| 234 | *shadow_pte &= ~PT_PRESENT_MASK; |
| 235 | return; |
| 236 | } |
| 237 | |
| 238 | *shadow_pte |= paddr; |
| 239 | |
Avi Kivity | 63b1ad2 | 2007-05-31 11:56:54 +0300 | [diff] [blame] | 240 | if (!write_fault && (*shadow_pte & PT_SHADOW_USER_MASK) && |
| 241 | !(*shadow_pte & PT_USER_MASK)) { |
| 242 | /* |
| 243 | * If supervisor write protect is disabled, we shadow kernel |
| 244 | * pages as user pages so we can trap the write access. |
| 245 | */ |
| 246 | *shadow_pte |= PT_USER_MASK; |
| 247 | *shadow_pte &= ~PT_WRITABLE_MASK; |
| 248 | access_bits &= ~PT_WRITABLE_MASK; |
| 249 | } |
| 250 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 251 | if ((access_bits & PT_WRITABLE_MASK) |
| 252 | || (write_fault && !is_write_protection(vcpu) && !user_fault)) { |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 253 | struct kvm_mmu_page *shadow; |
| 254 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 255 | *shadow_pte |= PT_WRITABLE_MASK; |
| 256 | if (user_fault) { |
| 257 | mmu_unshadow(vcpu, gfn); |
| 258 | goto unshadowed; |
| 259 | } |
| 260 | |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 261 | shadow = kvm_mmu_lookup_page(vcpu, gfn); |
| 262 | if (shadow) { |
| 263 | pgprintk("%s: found shadow page for %lx, marking ro\n", |
| 264 | __FUNCTION__, gfn); |
| 265 | access_bits &= ~PT_WRITABLE_MASK; |
| 266 | if (is_writeble_pte(*shadow_pte)) { |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 267 | *shadow_pte &= ~PT_WRITABLE_MASK; |
| 268 | kvm_arch_ops->tlb_flush(vcpu); |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 269 | } |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 270 | if (write_fault) |
| 271 | *ptwrite = 1; |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 272 | } |
| 273 | } |
| 274 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 275 | unshadowed: |
| 276 | |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 277 | if (access_bits & PT_WRITABLE_MASK) |
| 278 | mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT); |
| 279 | |
| 280 | page_header_update_slot(vcpu->kvm, shadow_pte, gaddr); |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 281 | if (!was_rmapped) |
| 282 | rmap_add(vcpu, shadow_pte); |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 283 | } |
| 284 | |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 285 | static void FNAME(set_pte)(struct kvm_vcpu *vcpu, pt_element_t *gpte, |
Avi Kivity | 63b1ad2 | 2007-05-31 11:56:54 +0300 | [diff] [blame] | 286 | u64 *shadow_pte, u64 access_bits, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 287 | int user_fault, int write_fault, int *ptwrite, |
| 288 | struct guest_walker *walker, gfn_t gfn) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 289 | { |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 290 | access_bits &= *gpte; |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 291 | *shadow_pte |= (*gpte & PT_PTE_COPY_MASK); |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 292 | FNAME(set_pte_common)(vcpu, shadow_pte, *gpte & PT_BASE_ADDR_MASK, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 293 | gpte, access_bits, user_fault, write_fault, |
| 294 | ptwrite, walker, gfn); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 295 | } |
| 296 | |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 297 | static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page, |
| 298 | u64 *spte, const void *pte, int bytes) |
| 299 | { |
| 300 | pt_element_t gpte; |
| 301 | |
| 302 | if (bytes < sizeof(pt_element_t)) |
| 303 | return; |
| 304 | gpte = *(const pt_element_t *)pte; |
| 305 | if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) |
| 306 | return; |
| 307 | pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte); |
Avi Kivity | 63b1ad2 | 2007-05-31 11:56:54 +0300 | [diff] [blame] | 308 | FNAME(set_pte)(vcpu, &gpte, spte, PT_USER_MASK | PT_WRITABLE_MASK, 0, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 309 | 0, NULL, NULL, |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 310 | (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT); |
| 311 | } |
| 312 | |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 313 | static void FNAME(set_pde)(struct kvm_vcpu *vcpu, pt_element_t *gpde, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 314 | u64 *shadow_pte, u64 access_bits, |
| 315 | int user_fault, int write_fault, int *ptwrite, |
| 316 | struct guest_walker *walker, gfn_t gfn) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 317 | { |
| 318 | gpa_t gaddr; |
| 319 | |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 320 | access_bits &= *gpde; |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 321 | gaddr = (gpa_t)gfn << PAGE_SHIFT; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 322 | if (PTTYPE == 32 && is_cpuid_PSE36()) |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 323 | gaddr |= (*gpde & PT32_DIR_PSE36_MASK) << |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 324 | (32 - PT32_DIR_PSE36_SHIFT); |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 325 | *shadow_pte |= *gpde & PT_PTE_COPY_MASK; |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 326 | FNAME(set_pte_common)(vcpu, shadow_pte, gaddr, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 327 | gpde, access_bits, user_fault, write_fault, |
| 328 | ptwrite, walker, gfn); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 329 | } |
| 330 | |
| 331 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 332 | * Fetch a shadow pte for a specific level in the paging hierarchy. |
| 333 | */ |
| 334 | static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 335 | struct guest_walker *walker, |
| 336 | int user_fault, int write_fault, int *ptwrite) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 337 | { |
| 338 | hpa_t shadow_addr; |
| 339 | int level; |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 340 | u64 *shadow_ent; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 341 | u64 *prev_shadow_ent = NULL; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 342 | pt_element_t *guest_ent = walker->ptep; |
| 343 | |
| 344 | if (!is_present_pte(*guest_ent)) |
| 345 | return NULL; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 346 | |
| 347 | shadow_addr = vcpu->mmu.root_hpa; |
| 348 | level = vcpu->mmu.shadow_root_level; |
Avi Kivity | aef3d3f | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 349 | if (level == PT32E_ROOT_LEVEL) { |
| 350 | shadow_addr = vcpu->mmu.pae_root[(addr >> 30) & 3]; |
| 351 | shadow_addr &= PT64_BASE_ADDR_MASK; |
| 352 | --level; |
| 353 | } |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 354 | |
| 355 | for (; ; level--) { |
| 356 | u32 index = SHADOW_PT_INDEX(addr, level); |
Avi Kivity | 25c0de2 | 2007-01-05 16:36:42 -0800 | [diff] [blame] | 357 | struct kvm_mmu_page *shadow_page; |
Avi Kivity | 8c7bb72 | 2006-12-13 00:34:02 -0800 | [diff] [blame] | 358 | u64 shadow_pte; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 359 | int metaphysical; |
| 360 | gfn_t table_gfn; |
Avi Kivity | d28c6cfb | 2007-03-23 09:55:25 +0200 | [diff] [blame] | 361 | unsigned hugepage_access = 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 362 | |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 363 | shadow_ent = ((u64 *)__va(shadow_addr)) + index; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 364 | if (is_present_pte(*shadow_ent) || is_io_pte(*shadow_ent)) { |
| 365 | if (level == PT_PAGE_TABLE_LEVEL) |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 366 | break; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 367 | shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK; |
| 368 | prev_shadow_ent = shadow_ent; |
| 369 | continue; |
| 370 | } |
| 371 | |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 372 | if (level == PT_PAGE_TABLE_LEVEL) |
| 373 | break; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 374 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 375 | if (level - 1 == PT_PAGE_TABLE_LEVEL |
| 376 | && walker->level == PT_DIRECTORY_LEVEL) { |
| 377 | metaphysical = 1; |
Avi Kivity | d28c6cfb | 2007-03-23 09:55:25 +0200 | [diff] [blame] | 378 | hugepage_access = *guest_ent; |
| 379 | hugepage_access &= PT_USER_MASK | PT_WRITABLE_MASK; |
| 380 | hugepage_access >>= PT_WRITABLE_SHIFT; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 381 | table_gfn = (*guest_ent & PT_BASE_ADDR_MASK) |
| 382 | >> PAGE_SHIFT; |
| 383 | } else { |
| 384 | metaphysical = 0; |
| 385 | table_gfn = walker->table_gfn[level - 2]; |
| 386 | } |
| 387 | shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1, |
Avi Kivity | d28c6cfb | 2007-03-23 09:55:25 +0200 | [diff] [blame] | 388 | metaphysical, hugepage_access, |
| 389 | shadow_ent); |
Avi Kivity | 47ad8e6 | 2007-05-06 15:50:58 +0300 | [diff] [blame] | 390 | shadow_addr = __pa(shadow_page->spt); |
Avi Kivity | aef3d3f | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 391 | shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK |
| 392 | | PT_WRITABLE_MASK | PT_USER_MASK; |
Avi Kivity | 8c7bb72 | 2006-12-13 00:34:02 -0800 | [diff] [blame] | 393 | *shadow_ent = shadow_pte; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 394 | prev_shadow_ent = shadow_ent; |
| 395 | } |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 396 | |
| 397 | if (walker->level == PT_DIRECTORY_LEVEL) { |
| 398 | if (prev_shadow_ent) |
| 399 | *prev_shadow_ent |= PT_SHADOW_PS_MARK; |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 400 | FNAME(set_pde)(vcpu, guest_ent, shadow_ent, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 401 | walker->inherited_ar, user_fault, write_fault, |
| 402 | ptwrite, walker, walker->gfn); |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 403 | } else { |
| 404 | ASSERT(walker->level == PT_PAGE_TABLE_LEVEL); |
Avi Kivity | 6598c8b | 2007-05-31 11:45:18 +0300 | [diff] [blame] | 405 | FNAME(set_pte)(vcpu, guest_ent, shadow_ent, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 406 | walker->inherited_ar, user_fault, write_fault, |
| 407 | ptwrite, walker, walker->gfn); |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 408 | } |
| 409 | return shadow_ent; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 410 | } |
| 411 | |
| 412 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 413 | * Page fault handler. There are several causes for a page fault: |
| 414 | * - there is no shadow pte for the guest pte |
| 415 | * - write access through a shadow pte marked read only so that we can set |
| 416 | * the dirty bit |
| 417 | * - write access to a shadow pte marked read only so we can update the page |
| 418 | * dirty bitmap, when userspace requests it |
| 419 | * - mmio access; in this case we will never install a present shadow pte |
| 420 | * - normal guest page fault due to the guest pte marked not present, not |
| 421 | * writable, or not executable |
| 422 | * |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 423 | * Returns: 1 if we need to emulate the instruction, 0 otherwise, or |
| 424 | * a negative value on error. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 425 | */ |
| 426 | static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, |
| 427 | u32 error_code) |
| 428 | { |
| 429 | int write_fault = error_code & PFERR_WRITE_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 430 | int user_fault = error_code & PFERR_USER_MASK; |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 431 | int fetch_fault = error_code & PFERR_FETCH_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 432 | struct guest_walker walker; |
| 433 | u64 *shadow_pte; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 434 | int write_pt = 0; |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 435 | int r; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 436 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 437 | pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code); |
Avi Kivity | 37a7d8b | 2007-01-05 16:36:56 -0800 | [diff] [blame] | 438 | kvm_mmu_audit(vcpu, "pre page fault"); |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 439 | |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 440 | r = mmu_topup_memory_caches(vcpu); |
| 441 | if (r) |
| 442 | return r; |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 443 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 444 | /* |
| 445 | * Look up the shadow pte for the faulting address. |
| 446 | */ |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 447 | r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault, |
| 448 | fetch_fault); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 449 | |
| 450 | /* |
| 451 | * The page is not mapped by the guest. Let the guest handle it. |
| 452 | */ |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 453 | if (!r) { |
| 454 | pgprintk("%s: guest page fault\n", __FUNCTION__); |
| 455 | inject_page_fault(vcpu, addr, walker.error_code); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 456 | FNAME(release_walker)(&walker); |
Avi Kivity | a25f7e1 | 2007-04-30 17:05:38 +0300 | [diff] [blame] | 457 | vcpu->last_pt_write_count = 0; /* reset fork detector */ |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 458 | return 0; |
| 459 | } |
| 460 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame^] | 461 | shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault, |
| 462 | &write_pt); |
| 463 | pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __FUNCTION__, |
| 464 | shadow_pte, *shadow_pte, write_pt); |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 465 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 466 | FNAME(release_walker)(&walker); |
| 467 | |
Avi Kivity | a25f7e1 | 2007-04-30 17:05:38 +0300 | [diff] [blame] | 468 | if (!write_pt) |
| 469 | vcpu->last_pt_write_count = 0; /* reset fork detector */ |
| 470 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 471 | /* |
| 472 | * mmio: emulate if accessible, otherwise its a guest fault. |
| 473 | */ |
Avi Kivity | d27d4ac | 2007-02-19 14:37:46 +0200 | [diff] [blame] | 474 | if (is_io_pte(*shadow_pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 475 | return 1; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 476 | |
Avi Kivity | 1165f5f | 2007-04-19 17:27:43 +0300 | [diff] [blame] | 477 | ++vcpu->stat.pf_fixed; |
Avi Kivity | 37a7d8b | 2007-01-05 16:36:56 -0800 | [diff] [blame] | 478 | kvm_mmu_audit(vcpu, "post page fault (fixed)"); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 479 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 480 | return write_pt; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 481 | } |
| 482 | |
| 483 | static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) |
| 484 | { |
| 485 | struct guest_walker walker; |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 486 | gpa_t gpa = UNMAPPED_GVA; |
| 487 | int r; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 488 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 489 | r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 490 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 491 | if (r) { |
| 492 | gpa = (gpa_t)walker.gfn << PAGE_SHIFT; |
| 493 | gpa |= vaddr & ~PAGE_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 494 | } |
| 495 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 496 | FNAME(release_walker)(&walker); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 497 | return gpa; |
| 498 | } |
| 499 | |
| 500 | #undef pt_element_t |
| 501 | #undef guest_walker |
| 502 | #undef FNAME |
| 503 | #undef PT_BASE_ADDR_MASK |
| 504 | #undef PT_INDEX |
| 505 | #undef SHADOW_PT_INDEX |
| 506 | #undef PT_LEVEL_MASK |
| 507 | #undef PT_PTE_COPY_MASK |
| 508 | #undef PT_NON_PTE_COPY_MASK |
| 509 | #undef PT_DIR_BASE_ADDR_MASK |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 510 | #undef PT_MAX_FULL_LEVELS |