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) |
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 |
| 47 | #define PT_DIR_BASE_ADDR_MASK PT32_DIR_BASE_ADDR_MASK |
| 48 | #define PT_INDEX(addr, level) PT32_INDEX(addr, level) |
| 49 | #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) |
| 50 | #define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level) |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 51 | #define PT_LEVEL_BITS PT32_LEVEL_BITS |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 52 | #define PT_MAX_FULL_LEVELS 2 |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 53 | #define CMPXCHG cmpxchg |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 54 | #else |
| 55 | #error Invalid PTTYPE value |
| 56 | #endif |
| 57 | |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 58 | #define gpte_to_gfn FNAME(gpte_to_gfn) |
| 59 | #define gpte_to_gfn_pde FNAME(gpte_to_gfn_pde) |
| 60 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 61 | /* |
| 62 | * The guest_walker structure emulates the behavior of the hardware page |
| 63 | * table walker. |
| 64 | */ |
| 65 | struct guest_walker { |
| 66 | int 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]; |
| 69 | gpa_t pte_gpa[PT_MAX_FULL_LEVELS]; |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 70 | unsigned pt_access; |
| 71 | unsigned pte_access; |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 72 | gfn_t gfn; |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 73 | u32 error_code; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 74 | }; |
| 75 | |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 76 | static gfn_t gpte_to_gfn(pt_element_t gpte) |
| 77 | { |
| 78 | return (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| 79 | } |
| 80 | |
| 81 | static gfn_t gpte_to_gfn_pde(pt_element_t gpte) |
| 82 | { |
| 83 | return (gpte & PT_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| 84 | } |
| 85 | |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 86 | static bool FNAME(cmpxchg_gpte)(struct kvm *kvm, |
| 87 | gfn_t table_gfn, unsigned index, |
| 88 | pt_element_t orig_pte, pt_element_t new_pte) |
| 89 | { |
| 90 | pt_element_t ret; |
| 91 | pt_element_t *table; |
| 92 | struct page *page; |
| 93 | |
| 94 | page = gfn_to_page(kvm, table_gfn); |
| 95 | table = kmap_atomic(page, KM_USER0); |
| 96 | |
| 97 | ret = CMPXCHG(&table[index], orig_pte, new_pte); |
| 98 | |
| 99 | kunmap_atomic(table, KM_USER0); |
| 100 | |
| 101 | kvm_release_page_dirty(page); |
| 102 | |
| 103 | return (ret != orig_pte); |
| 104 | } |
| 105 | |
Avi Kivity | bedbe4e | 2007-12-09 16:52:56 +0200 | [diff] [blame] | 106 | static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte) |
| 107 | { |
| 108 | unsigned access; |
| 109 | |
| 110 | access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK; |
| 111 | #if PTTYPE == 64 |
| 112 | if (is_nx(vcpu)) |
| 113 | access &= ~(gpte >> PT64_NX_SHIFT); |
| 114 | #endif |
| 115 | return access; |
| 116 | } |
| 117 | |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 118 | /* |
| 119 | * Fetch a guest pte for a guest virtual address |
| 120 | */ |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 121 | static int FNAME(walk_addr)(struct guest_walker *walker, |
| 122 | struct kvm_vcpu *vcpu, gva_t addr, |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 123 | int write_fault, int user_fault, int fetch_fault) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 124 | { |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 125 | pt_element_t pte; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 126 | gfn_t table_gfn; |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 127 | unsigned index, pt_access, pte_access; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 128 | gpa_t pte_gpa; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 129 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 130 | pgprintk("%s: addr %lx\n", __FUNCTION__, addr); |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 131 | walk: |
Zhang Xiantao | ad312c7 | 2007-12-13 23:50:52 +0800 | [diff] [blame^] | 132 | walker->level = vcpu->arch.mmu.root_level; |
| 133 | pte = vcpu->arch.cr3; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 134 | #if PTTYPE == 64 |
| 135 | if (!is_long_mode(vcpu)) { |
Zhang Xiantao | ad312c7 | 2007-12-13 23:50:52 +0800 | [diff] [blame^] | 136 | pte = vcpu->arch.pdptrs[(addr >> 30) & 3]; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 137 | if (!is_present_pte(pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 138 | goto not_present; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 139 | --walker->level; |
| 140 | } |
| 141 | #endif |
Avi Kivity | a9058ec | 2006-12-29 16:49:37 -0800 | [diff] [blame] | 142 | ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) || |
Rusty Russell | f802a30 | 2007-07-17 23:32:55 +1000 | [diff] [blame] | 143 | (vcpu->cr3 & CR3_NONPAE_RESERVED_BITS) == 0); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 144 | |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 145 | pt_access = ACC_ALL; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 146 | |
| 147 | for (;;) { |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 148 | index = PT_INDEX(addr, walker->level); |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 149 | |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 150 | table_gfn = gpte_to_gfn(pte); |
Avi Kivity | 1755fbc | 2007-11-21 14:44:45 +0200 | [diff] [blame] | 151 | pte_gpa = gfn_to_gpa(table_gfn); |
Izik Eidus | ec8d4ea | 2007-11-19 11:28:19 +0200 | [diff] [blame] | 152 | pte_gpa += index * sizeof(pt_element_t); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 153 | walker->table_gfn[walker->level - 1] = table_gfn; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 154 | walker->pte_gpa[walker->level - 1] = pte_gpa; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 155 | pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__, |
| 156 | walker->level - 1, table_gfn); |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 157 | |
Izik Eidus | ec8d4ea | 2007-11-19 11:28:19 +0200 | [diff] [blame] | 158 | kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte)); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 159 | |
| 160 | if (!is_present_pte(pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 161 | goto not_present; |
| 162 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 163 | if (write_fault && !is_writeble_pte(pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 164 | if (user_fault || is_write_protection(vcpu)) |
| 165 | goto access_error; |
| 166 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 167 | if (user_fault && !(pte & PT_USER_MASK)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 168 | goto access_error; |
| 169 | |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 170 | #if PTTYPE == 64 |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 171 | if (fetch_fault && is_nx(vcpu) && (pte & PT64_NX_MASK)) |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 172 | goto access_error; |
| 173 | #endif |
| 174 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 175 | if (!(pte & PT_ACCESSED_MASK)) { |
Avi Kivity | bf3f8e8 | 2007-02-19 14:37:46 +0200 | [diff] [blame] | 176 | mark_page_dirty(vcpu->kvm, table_gfn); |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 177 | if (FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn, |
| 178 | index, pte, pte|PT_ACCESSED_MASK)) |
| 179 | goto walk; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 180 | pte |= PT_ACCESSED_MASK; |
Avi Kivity | bf3f8e8 | 2007-02-19 14:37:46 +0200 | [diff] [blame] | 181 | } |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 182 | |
Avi Kivity | bedbe4e | 2007-12-09 16:52:56 +0200 | [diff] [blame] | 183 | pte_access = pt_access & FNAME(gpte_access)(vcpu, pte); |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 184 | |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 185 | walker->ptes[walker->level - 1] = pte; |
| 186 | |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 187 | if (walker->level == PT_PAGE_TABLE_LEVEL) { |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 188 | walker->gfn = gpte_to_gfn(pte); |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 189 | break; |
| 190 | } |
| 191 | |
| 192 | if (walker->level == PT_DIRECTORY_LEVEL |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 193 | && (pte & PT_PAGE_SIZE_MASK) |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 194 | && (PTTYPE == 64 || is_pse(vcpu))) { |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 195 | walker->gfn = gpte_to_gfn_pde(pte); |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 196 | walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL); |
Avi Kivity | da92852 | 2007-11-21 13:54:47 +0200 | [diff] [blame] | 197 | if (PTTYPE == 32 && is_cpuid_PSE36()) |
| 198 | walker->gfn += pse36_gfn_delta(pte); |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 199 | break; |
| 200 | } |
| 201 | |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 202 | pt_access = pte_access; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 203 | --walker->level; |
| 204 | } |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 205 | |
| 206 | if (write_fault && !is_dirty_pte(pte)) { |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 207 | bool ret; |
| 208 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 209 | mark_page_dirty(vcpu->kvm, table_gfn); |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 210 | ret = FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn, index, pte, |
| 211 | pte|PT_DIRTY_MASK); |
| 212 | if (ret) |
| 213 | goto walk; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 214 | pte |= PT_DIRTY_MASK; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 215 | kvm_mmu_pte_write(vcpu, pte_gpa, (u8 *)&pte, sizeof(pte)); |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 216 | walker->ptes[walker->level - 1] = pte; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 217 | } |
| 218 | |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 219 | walker->pt_access = pt_access; |
| 220 | walker->pte_access = pte_access; |
| 221 | pgprintk("%s: pte %llx pte_access %x pt_access %x\n", |
| 222 | __FUNCTION__, (u64)pte, pt_access, pte_access); |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 223 | return 1; |
| 224 | |
| 225 | not_present: |
| 226 | walker->error_code = 0; |
| 227 | goto err; |
| 228 | |
| 229 | access_error: |
| 230 | walker->error_code = PFERR_PRESENT_MASK; |
| 231 | |
| 232 | err: |
| 233 | if (write_fault) |
| 234 | walker->error_code |= PFERR_WRITE_MASK; |
| 235 | if (user_fault) |
| 236 | walker->error_code |= PFERR_USER_MASK; |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 237 | if (fetch_fault) |
| 238 | walker->error_code |= PFERR_FETCH_MASK; |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 239 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 240 | } |
| 241 | |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 242 | static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page, |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 243 | u64 *spte, const void *pte, int bytes, |
| 244 | int offset_in_pte) |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 245 | { |
| 246 | pt_element_t gpte; |
Avi Kivity | 41074d0 | 2007-12-09 17:00:02 +0200 | [diff] [blame] | 247 | unsigned pte_access; |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 248 | |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 249 | gpte = *(const pt_element_t *)pte; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 250 | if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) { |
| 251 | if (!offset_in_pte && !is_present_pte(gpte)) |
| 252 | set_shadow_pte(spte, shadow_notrap_nonpresent_pte); |
| 253 | return; |
| 254 | } |
| 255 | if (bytes < sizeof(pt_element_t)) |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 256 | return; |
| 257 | pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte); |
Avi Kivity | 41074d0 | 2007-12-09 17:00:02 +0200 | [diff] [blame] | 258 | pte_access = page->role.access & FNAME(gpte_access)(vcpu, gpte); |
Avi Kivity | 1c4f1fd | 2007-12-09 17:40:31 +0200 | [diff] [blame] | 259 | mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0, |
| 260 | gpte & PT_DIRTY_MASK, NULL, gpte_to_gfn(gpte)); |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 261 | } |
| 262 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 263 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 264 | * Fetch a shadow pte for a specific level in the paging hierarchy. |
| 265 | */ |
| 266 | static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 267 | struct guest_walker *walker, |
| 268 | int user_fault, int write_fault, int *ptwrite) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 269 | { |
| 270 | hpa_t shadow_addr; |
| 271 | int level; |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 272 | u64 *shadow_ent; |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 273 | unsigned access = walker->pt_access; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 274 | |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 275 | if (!is_present_pte(walker->ptes[walker->level - 1])) |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 276 | return NULL; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 277 | |
Zhang Xiantao | ad312c7 | 2007-12-13 23:50:52 +0800 | [diff] [blame^] | 278 | shadow_addr = vcpu->arch.mmu.root_hpa; |
| 279 | level = vcpu->arch.mmu.shadow_root_level; |
Avi Kivity | aef3d3f | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 280 | if (level == PT32E_ROOT_LEVEL) { |
Zhang Xiantao | ad312c7 | 2007-12-13 23:50:52 +0800 | [diff] [blame^] | 281 | shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3]; |
Avi Kivity | aef3d3f | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 282 | shadow_addr &= PT64_BASE_ADDR_MASK; |
| 283 | --level; |
| 284 | } |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 285 | |
| 286 | for (; ; level--) { |
| 287 | u32 index = SHADOW_PT_INDEX(addr, level); |
Avi Kivity | 25c0de2 | 2007-01-05 16:36:42 -0800 | [diff] [blame] | 288 | struct kvm_mmu_page *shadow_page; |
Avi Kivity | 8c7bb72 | 2006-12-13 00:34:02 -0800 | [diff] [blame] | 289 | u64 shadow_pte; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 290 | int metaphysical; |
| 291 | gfn_t table_gfn; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 292 | bool new_page = 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 293 | |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 294 | shadow_ent = ((u64 *)__va(shadow_addr)) + index; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 295 | if (is_shadow_present_pte(*shadow_ent)) { |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 296 | if (level == PT_PAGE_TABLE_LEVEL) |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 297 | break; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 298 | shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 299 | continue; |
| 300 | } |
| 301 | |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 302 | if (level == PT_PAGE_TABLE_LEVEL) |
| 303 | break; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 304 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 305 | if (level - 1 == PT_PAGE_TABLE_LEVEL |
| 306 | && walker->level == PT_DIRECTORY_LEVEL) { |
| 307 | metaphysical = 1; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 308 | if (!is_dirty_pte(walker->ptes[level - 1])) |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 309 | access &= ~ACC_WRITE_MASK; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 310 | table_gfn = gpte_to_gfn(walker->ptes[level - 1]); |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 311 | } else { |
| 312 | metaphysical = 0; |
| 313 | table_gfn = walker->table_gfn[level - 2]; |
| 314 | } |
| 315 | shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1, |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 316 | metaphysical, access, |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 317 | shadow_ent, &new_page); |
| 318 | if (new_page && !metaphysical) { |
| 319 | pt_element_t curr_pte; |
| 320 | kvm_read_guest(vcpu->kvm, walker->pte_gpa[level - 2], |
| 321 | &curr_pte, sizeof(curr_pte)); |
| 322 | if (curr_pte != walker->ptes[level - 2]) |
| 323 | return NULL; |
| 324 | } |
Avi Kivity | 47ad8e6 | 2007-05-06 15:50:58 +0300 | [diff] [blame] | 325 | shadow_addr = __pa(shadow_page->spt); |
Avi Kivity | aef3d3f | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 326 | shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK |
| 327 | | PT_WRITABLE_MASK | PT_USER_MASK; |
Avi Kivity | 8c7bb72 | 2006-12-13 00:34:02 -0800 | [diff] [blame] | 328 | *shadow_ent = shadow_pte; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 329 | } |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 330 | |
Avi Kivity | 1c4f1fd | 2007-12-09 17:40:31 +0200 | [diff] [blame] | 331 | mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access, |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 332 | user_fault, write_fault, |
| 333 | walker->ptes[walker->level-1] & PT_DIRTY_MASK, |
Avi Kivity | 1c4f1fd | 2007-12-09 17:40:31 +0200 | [diff] [blame] | 334 | ptwrite, walker->gfn); |
Avi Kivity | 050e649 | 2007-11-21 14:11:49 +0200 | [diff] [blame] | 335 | |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 336 | return shadow_ent; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 337 | } |
| 338 | |
| 339 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 340 | * Page fault handler. There are several causes for a page fault: |
| 341 | * - there is no shadow pte for the guest pte |
| 342 | * - write access through a shadow pte marked read only so that we can set |
| 343 | * the dirty bit |
| 344 | * - write access to a shadow pte marked read only so we can update the page |
| 345 | * dirty bitmap, when userspace requests it |
| 346 | * - mmio access; in this case we will never install a present shadow pte |
| 347 | * - normal guest page fault due to the guest pte marked not present, not |
| 348 | * writable, or not executable |
| 349 | * |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 350 | * Returns: 1 if we need to emulate the instruction, 0 otherwise, or |
| 351 | * a negative value on error. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 352 | */ |
| 353 | static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, |
| 354 | u32 error_code) |
| 355 | { |
| 356 | int write_fault = error_code & PFERR_WRITE_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 357 | int user_fault = error_code & PFERR_USER_MASK; |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 358 | int fetch_fault = error_code & PFERR_FETCH_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 359 | struct guest_walker walker; |
| 360 | u64 *shadow_pte; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 361 | int write_pt = 0; |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 362 | int r; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 363 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 364 | pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code); |
Avi Kivity | 37a7d8b | 2007-01-05 16:36:56 -0800 | [diff] [blame] | 365 | kvm_mmu_audit(vcpu, "pre page fault"); |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 366 | |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 367 | r = mmu_topup_memory_caches(vcpu); |
| 368 | if (r) |
| 369 | return r; |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 370 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 371 | /* |
| 372 | * Look up the shadow pte for the faulting address. |
| 373 | */ |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 374 | r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault, |
| 375 | fetch_fault); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 376 | |
| 377 | /* |
| 378 | * The page is not mapped by the guest. Let the guest handle it. |
| 379 | */ |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 380 | if (!r) { |
| 381 | pgprintk("%s: guest page fault\n", __FUNCTION__); |
| 382 | inject_page_fault(vcpu, addr, walker.error_code); |
Zhang Xiantao | ad312c7 | 2007-12-13 23:50:52 +0800 | [diff] [blame^] | 383 | vcpu->arch.last_pt_write_count = 0; /* reset fork detector */ |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 384 | return 0; |
| 385 | } |
| 386 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 387 | shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault, |
| 388 | &write_pt); |
| 389 | pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __FUNCTION__, |
| 390 | shadow_pte, *shadow_pte, write_pt); |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 391 | |
Avi Kivity | a25f7e1 | 2007-04-30 17:05:38 +0300 | [diff] [blame] | 392 | if (!write_pt) |
Zhang Xiantao | ad312c7 | 2007-12-13 23:50:52 +0800 | [diff] [blame^] | 393 | vcpu->arch.last_pt_write_count = 0; /* reset fork detector */ |
Avi Kivity | a25f7e1 | 2007-04-30 17:05:38 +0300 | [diff] [blame] | 394 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 395 | /* |
| 396 | * mmio: emulate if accessible, otherwise its a guest fault. |
| 397 | */ |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 398 | if (shadow_pte && is_io_pte(*shadow_pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 399 | return 1; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 400 | |
Avi Kivity | 1165f5f | 2007-04-19 17:27:43 +0300 | [diff] [blame] | 401 | ++vcpu->stat.pf_fixed; |
Avi Kivity | 37a7d8b | 2007-01-05 16:36:56 -0800 | [diff] [blame] | 402 | kvm_mmu_audit(vcpu, "post page fault (fixed)"); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 403 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 404 | return write_pt; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 405 | } |
| 406 | |
| 407 | static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) |
| 408 | { |
| 409 | struct guest_walker walker; |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 410 | gpa_t gpa = UNMAPPED_GVA; |
| 411 | int r; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 412 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 413 | r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 414 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 415 | if (r) { |
Avi Kivity | 1755fbc | 2007-11-21 14:44:45 +0200 | [diff] [blame] | 416 | gpa = gfn_to_gpa(walker.gfn); |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 417 | gpa |= vaddr & ~PAGE_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 418 | } |
| 419 | |
| 420 | return gpa; |
| 421 | } |
| 422 | |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 423 | static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, |
| 424 | struct kvm_mmu_page *sp) |
| 425 | { |
Avi Kivity | e5a4c8c | 2007-11-20 21:39:54 +0200 | [diff] [blame] | 426 | int i, offset = 0; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 427 | pt_element_t *gpt; |
Izik Eidus | 8a7ae05 | 2007-10-18 11:09:33 +0200 | [diff] [blame] | 428 | struct page *page; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 429 | |
Avi Kivity | e5a4c8c | 2007-11-20 21:39:54 +0200 | [diff] [blame] | 430 | if (sp->role.metaphysical |
| 431 | || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) { |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 432 | nonpaging_prefetch_page(vcpu, sp); |
| 433 | return; |
| 434 | } |
| 435 | |
Avi Kivity | e5a4c8c | 2007-11-20 21:39:54 +0200 | [diff] [blame] | 436 | if (PTTYPE == 32) |
| 437 | offset = sp->role.quadrant << PT64_LEVEL_BITS; |
Izik Eidus | 8a7ae05 | 2007-10-18 11:09:33 +0200 | [diff] [blame] | 438 | page = gfn_to_page(vcpu->kvm, sp->gfn); |
| 439 | gpt = kmap_atomic(page, KM_USER0); |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 440 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) |
Avi Kivity | e5a4c8c | 2007-11-20 21:39:54 +0200 | [diff] [blame] | 441 | if (is_present_pte(gpt[offset + i])) |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 442 | sp->spt[i] = shadow_trap_nonpresent_pte; |
| 443 | else |
| 444 | sp->spt[i] = shadow_notrap_nonpresent_pte; |
| 445 | kunmap_atomic(gpt, KM_USER0); |
Izik Eidus | b4231d6 | 2007-11-20 11:49:33 +0200 | [diff] [blame] | 446 | kvm_release_page_clean(page); |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 447 | } |
| 448 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 449 | #undef pt_element_t |
| 450 | #undef guest_walker |
| 451 | #undef FNAME |
| 452 | #undef PT_BASE_ADDR_MASK |
| 453 | #undef PT_INDEX |
| 454 | #undef SHADOW_PT_INDEX |
| 455 | #undef PT_LEVEL_MASK |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 456 | #undef PT_DIR_BASE_ADDR_MASK |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 457 | #undef PT_LEVEL_BITS |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 458 | #undef PT_MAX_FULL_LEVELS |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 459 | #undef gpte_to_gfn |
| 460 | #undef gpte_to_gfn_pde |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 461 | #undef CMPXCHG |