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 |
| 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) |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 49 | #define PT_LEVEL_BITS PT32_LEVEL_BITS |
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 | |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 55 | #define gpte_to_gfn FNAME(gpte_to_gfn) |
| 56 | #define gpte_to_gfn_pde FNAME(gpte_to_gfn_pde) |
| 57 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 58 | /* |
| 59 | * The guest_walker structure emulates the behavior of the hardware page |
| 60 | * table walker. |
| 61 | */ |
| 62 | struct guest_walker { |
| 63 | int level; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 64 | gfn_t table_gfn[PT_MAX_FULL_LEVELS]; |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 65 | pt_element_t pte; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 66 | pt_element_t inherited_ar; |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 67 | gfn_t gfn; |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 68 | u32 error_code; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 69 | }; |
| 70 | |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 71 | static gfn_t gpte_to_gfn(pt_element_t gpte) |
| 72 | { |
| 73 | return (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| 74 | } |
| 75 | |
| 76 | static gfn_t gpte_to_gfn_pde(pt_element_t gpte) |
| 77 | { |
| 78 | return (gpte & PT_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| 79 | } |
| 80 | |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 81 | /* |
| 82 | * Fetch a guest pte for a guest virtual address |
| 83 | */ |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 84 | static int FNAME(walk_addr)(struct guest_walker *walker, |
| 85 | struct kvm_vcpu *vcpu, gva_t addr, |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 86 | int write_fault, int user_fault, int fetch_fault) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 87 | { |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 88 | pt_element_t pte; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 89 | gfn_t table_gfn; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 90 | unsigned index; |
| 91 | gpa_t pte_gpa; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 92 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 93 | pgprintk("%s: addr %lx\n", __FUNCTION__, addr); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 94 | walker->level = vcpu->mmu.root_level; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 95 | pte = vcpu->cr3; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 96 | #if PTTYPE == 64 |
| 97 | if (!is_long_mode(vcpu)) { |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 98 | pte = vcpu->pdptrs[(addr >> 30) & 3]; |
| 99 | if (!is_present_pte(pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 100 | goto not_present; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 101 | --walker->level; |
| 102 | } |
| 103 | #endif |
Avi Kivity | a9058ec | 2006-12-29 16:49:37 -0800 | [diff] [blame] | 104 | ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) || |
Rusty Russell | f802a30 | 2007-07-17 23:32:55 +1000 | [diff] [blame] | 105 | (vcpu->cr3 & CR3_NONPAE_RESERVED_BITS) == 0); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 106 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 107 | walker->inherited_ar = PT_USER_MASK | PT_WRITABLE_MASK; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 108 | |
| 109 | for (;;) { |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 110 | index = PT_INDEX(addr, walker->level); |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 111 | |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 112 | table_gfn = gpte_to_gfn(pte); |
Avi Kivity | 1755fbc | 2007-11-21 14:44:45 +0200 | [diff] [blame^] | 113 | pte_gpa = gfn_to_gpa(table_gfn); |
Izik Eidus | ec8d4ea | 2007-11-19 11:28:19 +0200 | [diff] [blame] | 114 | pte_gpa += index * sizeof(pt_element_t); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 115 | walker->table_gfn[walker->level - 1] = table_gfn; |
| 116 | pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__, |
| 117 | walker->level - 1, table_gfn); |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 118 | |
Izik Eidus | ec8d4ea | 2007-11-19 11:28:19 +0200 | [diff] [blame] | 119 | kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte)); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 120 | |
| 121 | if (!is_present_pte(pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 122 | goto not_present; |
| 123 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 124 | if (write_fault && !is_writeble_pte(pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 125 | if (user_fault || is_write_protection(vcpu)) |
| 126 | goto access_error; |
| 127 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 128 | if (user_fault && !(pte & PT_USER_MASK)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 129 | goto access_error; |
| 130 | |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 131 | #if PTTYPE == 64 |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 132 | if (fetch_fault && is_nx(vcpu) && (pte & PT64_NX_MASK)) |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 133 | goto access_error; |
| 134 | #endif |
| 135 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 136 | if (!(pte & PT_ACCESSED_MASK)) { |
Avi Kivity | bf3f8e8 | 2007-02-19 14:37:46 +0200 | [diff] [blame] | 137 | mark_page_dirty(vcpu->kvm, table_gfn); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 138 | pte |= PT_ACCESSED_MASK; |
Izik Eidus | ec8d4ea | 2007-11-19 11:28:19 +0200 | [diff] [blame] | 139 | kvm_write_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte)); |
Avi Kivity | bf3f8e8 | 2007-02-19 14:37:46 +0200 | [diff] [blame] | 140 | } |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 141 | |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 142 | if (walker->level == PT_PAGE_TABLE_LEVEL) { |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 143 | walker->gfn = gpte_to_gfn(pte); |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 144 | break; |
| 145 | } |
| 146 | |
| 147 | if (walker->level == PT_DIRECTORY_LEVEL |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 148 | && (pte & PT_PAGE_SIZE_MASK) |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 149 | && (PTTYPE == 64 || is_pse(vcpu))) { |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 150 | walker->gfn = gpte_to_gfn_pde(pte); |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 151 | walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL); |
Avi Kivity | da92852 | 2007-11-21 13:54:47 +0200 | [diff] [blame] | 152 | if (PTTYPE == 32 && is_cpuid_PSE36()) |
| 153 | walker->gfn += pse36_gfn_delta(pte); |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 154 | break; |
| 155 | } |
| 156 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 157 | walker->inherited_ar &= pte; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 158 | --walker->level; |
| 159 | } |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 160 | |
| 161 | if (write_fault && !is_dirty_pte(pte)) { |
| 162 | mark_page_dirty(vcpu->kvm, table_gfn); |
| 163 | pte |= PT_DIRTY_MASK; |
Izik Eidus | ec8d4ea | 2007-11-19 11:28:19 +0200 | [diff] [blame] | 164 | kvm_write_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte)); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 165 | kvm_mmu_pte_write(vcpu, pte_gpa, (u8 *)&pte, sizeof(pte)); |
| 166 | } |
| 167 | |
| 168 | walker->pte = pte; |
| 169 | pgprintk("%s: pte %llx\n", __FUNCTION__, (u64)pte); |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 170 | return 1; |
| 171 | |
| 172 | not_present: |
| 173 | walker->error_code = 0; |
| 174 | goto err; |
| 175 | |
| 176 | access_error: |
| 177 | walker->error_code = PFERR_PRESENT_MASK; |
| 178 | |
| 179 | err: |
| 180 | if (write_fault) |
| 181 | walker->error_code |= PFERR_WRITE_MASK; |
| 182 | if (user_fault) |
| 183 | walker->error_code |= PFERR_USER_MASK; |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 184 | if (fetch_fault) |
| 185 | walker->error_code |= PFERR_FETCH_MASK; |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 186 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 187 | } |
| 188 | |
Avi Kivity | 230c9a8 | 2007-11-21 14:16:30 +0200 | [diff] [blame] | 189 | static void FNAME(set_pte)(struct kvm_vcpu *vcpu, pt_element_t gpte, |
| 190 | u64 *shadow_pte, u64 access_bits, |
| 191 | int user_fault, int write_fault, |
| 192 | int *ptwrite, struct guest_walker *walker, |
| 193 | gfn_t gfn) |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 194 | { |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 195 | int dirty = gpte & PT_DIRTY_MASK; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 196 | u64 spte; |
| 197 | int was_rmapped = is_rmap_pte(*shadow_pte); |
Izik Eidus | b238f7b | 2007-11-20 12:02:12 +0200 | [diff] [blame] | 198 | struct page *page; |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 199 | |
| 200 | pgprintk("%s: spte %llx gpte %llx access %llx write_fault %d" |
| 201 | " user_fault %d gfn %lx\n", |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 202 | __FUNCTION__, *shadow_pte, (u64)gpte, access_bits, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 203 | write_fault, user_fault, gfn); |
| 204 | |
Avi Kivity | 230c9a8 | 2007-11-21 14:16:30 +0200 | [diff] [blame] | 205 | access_bits &= gpte; |
Avi Kivity | 12b7d28 | 2007-09-23 14:10:49 +0200 | [diff] [blame] | 206 | /* |
| 207 | * We don't set the accessed bit, since we sometimes want to see |
| 208 | * whether the guest actually used the pte (in order to detect |
| 209 | * demand paging). |
| 210 | */ |
| 211 | spte = PT_PRESENT_MASK | PT_DIRTY_MASK; |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 212 | spte |= gpte & PT64_NX_MASK; |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 213 | if (!dirty) |
| 214 | access_bits &= ~PT_WRITABLE_MASK; |
| 215 | |
Avi Kivity | 4e54237 | 2007-11-21 14:08:40 +0200 | [diff] [blame] | 216 | page = gfn_to_page(vcpu->kvm, gfn); |
Izik Eidus | b238f7b | 2007-11-20 12:02:12 +0200 | [diff] [blame] | 217 | |
Avi Kivity | 0d551bb | 2007-05-31 15:23:35 +0300 | [diff] [blame] | 218 | spte |= PT_PRESENT_MASK; |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 219 | if (access_bits & PT_USER_MASK) |
Avi Kivity | 0d551bb | 2007-05-31 15:23:35 +0300 | [diff] [blame] | 220 | spte |= PT_USER_MASK; |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 221 | |
Avi Kivity | 4e54237 | 2007-11-21 14:08:40 +0200 | [diff] [blame] | 222 | if (is_error_page(page)) { |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 223 | set_shadow_pte(shadow_pte, |
| 224 | shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK); |
Izik Eidus | b238f7b | 2007-11-20 12:02:12 +0200 | [diff] [blame] | 225 | kvm_release_page_clean(page); |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 226 | return; |
| 227 | } |
| 228 | |
Avi Kivity | 4e54237 | 2007-11-21 14:08:40 +0200 | [diff] [blame] | 229 | spte |= page_to_phys(page); |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 230 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 231 | if ((access_bits & PT_WRITABLE_MASK) |
| 232 | || (write_fault && !is_write_protection(vcpu) && !user_fault)) { |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 233 | struct kvm_mmu_page *shadow; |
| 234 | |
Avi Kivity | 0d551bb | 2007-05-31 15:23:35 +0300 | [diff] [blame] | 235 | spte |= PT_WRITABLE_MASK; |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 236 | if (user_fault) { |
Anthony Liguori | f67a46f | 2007-10-10 19:25:50 -0500 | [diff] [blame] | 237 | mmu_unshadow(vcpu->kvm, gfn); |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 238 | goto unshadowed; |
| 239 | } |
| 240 | |
Anthony Liguori | f67a46f | 2007-10-10 19:25:50 -0500 | [diff] [blame] | 241 | shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn); |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 242 | if (shadow) { |
| 243 | pgprintk("%s: found shadow page for %lx, marking ro\n", |
| 244 | __FUNCTION__, gfn); |
| 245 | access_bits &= ~PT_WRITABLE_MASK; |
Avi Kivity | 0d551bb | 2007-05-31 15:23:35 +0300 | [diff] [blame] | 246 | if (is_writeble_pte(spte)) { |
| 247 | spte &= ~PT_WRITABLE_MASK; |
Christian Ehrhardt | cbdd1be | 2007-09-09 15:41:59 +0300 | [diff] [blame] | 248 | kvm_x86_ops->tlb_flush(vcpu); |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 249 | } |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 250 | if (write_fault) |
| 251 | *ptwrite = 1; |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 252 | } |
| 253 | } |
| 254 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 255 | unshadowed: |
| 256 | |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 257 | if (access_bits & PT_WRITABLE_MASK) |
Avi Kivity | 4e54237 | 2007-11-21 14:08:40 +0200 | [diff] [blame] | 258 | mark_page_dirty(vcpu->kvm, gfn); |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 259 | |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 260 | pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte); |
Avi Kivity | e663ee6 | 2007-05-31 15:46:04 +0300 | [diff] [blame] | 261 | set_shadow_pte(shadow_pte, spte); |
Avi Kivity | 38c335f | 2007-11-21 14:20:22 +0200 | [diff] [blame] | 262 | page_header_update_slot(vcpu->kvm, shadow_pte, gfn); |
Izik Eidus | 8a7ae05 | 2007-10-18 11:09:33 +0200 | [diff] [blame] | 263 | if (!was_rmapped) { |
Avi Kivity | 4e54237 | 2007-11-21 14:08:40 +0200 | [diff] [blame] | 264 | rmap_add(vcpu, shadow_pte, gfn); |
Izik Eidus | b238f7b | 2007-11-20 12:02:12 +0200 | [diff] [blame] | 265 | if (!is_rmap_pte(*shadow_pte)) |
Izik Eidus | b4231d6 | 2007-11-20 11:49:33 +0200 | [diff] [blame] | 266 | kvm_release_page_clean(page); |
Izik Eidus | 8a7ae05 | 2007-10-18 11:09:33 +0200 | [diff] [blame] | 267 | } |
| 268 | else |
Izik Eidus | b238f7b | 2007-11-20 12:02:12 +0200 | [diff] [blame] | 269 | kvm_release_page_clean(page); |
Avi Kivity | 12b7d28 | 2007-09-23 14:10:49 +0200 | [diff] [blame] | 270 | if (!ptwrite || !*ptwrite) |
| 271 | vcpu->last_pte_updated = shadow_pte; |
Avi Kivity | e60d75e | 2007-05-30 19:31:17 +0300 | [diff] [blame] | 272 | } |
| 273 | |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 274 | 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] | 275 | u64 *spte, const void *pte, int bytes, |
| 276 | int offset_in_pte) |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 277 | { |
| 278 | pt_element_t gpte; |
| 279 | |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 280 | gpte = *(const pt_element_t *)pte; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 281 | if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) { |
| 282 | if (!offset_in_pte && !is_present_pte(gpte)) |
| 283 | set_shadow_pte(spte, shadow_notrap_nonpresent_pte); |
| 284 | return; |
| 285 | } |
| 286 | if (bytes < sizeof(pt_element_t)) |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 287 | return; |
| 288 | pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte); |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 289 | FNAME(set_pte)(vcpu, gpte, spte, PT_USER_MASK | PT_WRITABLE_MASK, 0, |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 290 | 0, NULL, NULL, gpte_to_gfn(gpte)); |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 291 | } |
| 292 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 293 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 294 | * Fetch a shadow pte for a specific level in the paging hierarchy. |
| 295 | */ |
| 296 | static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 297 | struct guest_walker *walker, |
| 298 | int user_fault, int write_fault, int *ptwrite) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 299 | { |
| 300 | hpa_t shadow_addr; |
| 301 | int level; |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 302 | u64 *shadow_ent; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 303 | u64 *prev_shadow_ent = NULL; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 304 | |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 305 | if (!is_present_pte(walker->pte)) |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 306 | return NULL; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 307 | |
| 308 | shadow_addr = vcpu->mmu.root_hpa; |
| 309 | level = vcpu->mmu.shadow_root_level; |
Avi Kivity | aef3d3f | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 310 | if (level == PT32E_ROOT_LEVEL) { |
| 311 | shadow_addr = vcpu->mmu.pae_root[(addr >> 30) & 3]; |
| 312 | shadow_addr &= PT64_BASE_ADDR_MASK; |
| 313 | --level; |
| 314 | } |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 315 | |
| 316 | for (; ; level--) { |
| 317 | u32 index = SHADOW_PT_INDEX(addr, level); |
Avi Kivity | 25c0de2 | 2007-01-05 16:36:42 -0800 | [diff] [blame] | 318 | struct kvm_mmu_page *shadow_page; |
Avi Kivity | 8c7bb72 | 2006-12-13 00:34:02 -0800 | [diff] [blame] | 319 | u64 shadow_pte; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 320 | int metaphysical; |
| 321 | gfn_t table_gfn; |
Avi Kivity | d28c6cfb | 2007-03-23 09:55:25 +0200 | [diff] [blame] | 322 | unsigned hugepage_access = 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 323 | |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 324 | shadow_ent = ((u64 *)__va(shadow_addr)) + index; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 325 | if (is_shadow_present_pte(*shadow_ent)) { |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 326 | if (level == PT_PAGE_TABLE_LEVEL) |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 327 | break; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 328 | shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK; |
| 329 | prev_shadow_ent = shadow_ent; |
| 330 | continue; |
| 331 | } |
| 332 | |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 333 | if (level == PT_PAGE_TABLE_LEVEL) |
| 334 | break; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 335 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 336 | if (level - 1 == PT_PAGE_TABLE_LEVEL |
| 337 | && walker->level == PT_DIRECTORY_LEVEL) { |
| 338 | metaphysical = 1; |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 339 | hugepage_access = walker->pte; |
Avi Kivity | d28c6cfb | 2007-03-23 09:55:25 +0200 | [diff] [blame] | 340 | hugepage_access &= PT_USER_MASK | PT_WRITABLE_MASK; |
Avi Kivity | cc70e73 | 2007-10-11 15:12:24 +0200 | [diff] [blame] | 341 | if (!is_dirty_pte(walker->pte)) |
| 342 | hugepage_access &= ~PT_WRITABLE_MASK; |
Avi Kivity | c22e351 | 2007-10-11 15:08:41 +0200 | [diff] [blame] | 343 | hugepage_access >>= PT_WRITABLE_SHIFT; |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 344 | if (walker->pte & PT64_NX_MASK) |
Avi Kivity | d55e2cb | 2007-07-10 17:50:55 +0300 | [diff] [blame] | 345 | hugepage_access |= (1 << 2); |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 346 | table_gfn = gpte_to_gfn(walker->pte); |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 347 | } else { |
| 348 | metaphysical = 0; |
| 349 | table_gfn = walker->table_gfn[level - 2]; |
| 350 | } |
| 351 | shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1, |
Avi Kivity | d28c6cfb | 2007-03-23 09:55:25 +0200 | [diff] [blame] | 352 | metaphysical, hugepage_access, |
| 353 | shadow_ent); |
Avi Kivity | 47ad8e6 | 2007-05-06 15:50:58 +0300 | [diff] [blame] | 354 | shadow_addr = __pa(shadow_page->spt); |
Avi Kivity | aef3d3f | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 355 | shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK |
| 356 | | PT_WRITABLE_MASK | PT_USER_MASK; |
Avi Kivity | 8c7bb72 | 2006-12-13 00:34:02 -0800 | [diff] [blame] | 357 | *shadow_ent = shadow_pte; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 358 | prev_shadow_ent = shadow_ent; |
| 359 | } |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 360 | |
Avi Kivity | 050e649 | 2007-11-21 14:11:49 +0200 | [diff] [blame] | 361 | FNAME(set_pte)(vcpu, walker->pte, shadow_ent, |
| 362 | walker->inherited_ar, user_fault, write_fault, |
| 363 | ptwrite, walker, walker->gfn); |
| 364 | |
Avi Kivity | ef0197e | 2007-05-30 14:21:51 +0300 | [diff] [blame] | 365 | return shadow_ent; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 366 | } |
| 367 | |
| 368 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 369 | * Page fault handler. There are several causes for a page fault: |
| 370 | * - there is no shadow pte for the guest pte |
| 371 | * - write access through a shadow pte marked read only so that we can set |
| 372 | * the dirty bit |
| 373 | * - write access to a shadow pte marked read only so we can update the page |
| 374 | * dirty bitmap, when userspace requests it |
| 375 | * - mmio access; in this case we will never install a present shadow pte |
| 376 | * - normal guest page fault due to the guest pte marked not present, not |
| 377 | * writable, or not executable |
| 378 | * |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 379 | * Returns: 1 if we need to emulate the instruction, 0 otherwise, or |
| 380 | * a negative value on error. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 381 | */ |
| 382 | static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, |
| 383 | u32 error_code) |
| 384 | { |
| 385 | int write_fault = error_code & PFERR_WRITE_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 386 | int user_fault = error_code & PFERR_USER_MASK; |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 387 | int fetch_fault = error_code & PFERR_FETCH_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 388 | struct guest_walker walker; |
| 389 | u64 *shadow_pte; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 390 | int write_pt = 0; |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 391 | int r; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 392 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 393 | pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code); |
Avi Kivity | 37a7d8b | 2007-01-05 16:36:56 -0800 | [diff] [blame] | 394 | kvm_mmu_audit(vcpu, "pre page fault"); |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 395 | |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 396 | r = mmu_topup_memory_caches(vcpu); |
| 397 | if (r) |
| 398 | return r; |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 399 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 400 | /* |
| 401 | * Look up the shadow pte for the faulting address. |
| 402 | */ |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 403 | r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault, |
| 404 | fetch_fault); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 405 | |
| 406 | /* |
| 407 | * The page is not mapped by the guest. Let the guest handle it. |
| 408 | */ |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 409 | if (!r) { |
| 410 | pgprintk("%s: guest page fault\n", __FUNCTION__); |
| 411 | inject_page_fault(vcpu, addr, walker.error_code); |
Avi Kivity | a25f7e1 | 2007-04-30 17:05:38 +0300 | [diff] [blame] | 412 | vcpu->last_pt_write_count = 0; /* reset fork detector */ |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 413 | return 0; |
| 414 | } |
| 415 | |
Avi Kivity | 97a0a01 | 2007-05-31 15:08:29 +0300 | [diff] [blame] | 416 | shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault, |
| 417 | &write_pt); |
| 418 | pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __FUNCTION__, |
| 419 | shadow_pte, *shadow_pte, write_pt); |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 420 | |
Avi Kivity | a25f7e1 | 2007-04-30 17:05:38 +0300 | [diff] [blame] | 421 | if (!write_pt) |
| 422 | vcpu->last_pt_write_count = 0; /* reset fork detector */ |
| 423 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 424 | /* |
| 425 | * mmio: emulate if accessible, otherwise its a guest fault. |
| 426 | */ |
Avi Kivity | d27d4ac | 2007-02-19 14:37:46 +0200 | [diff] [blame] | 427 | if (is_io_pte(*shadow_pte)) |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 428 | return 1; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 429 | |
Avi Kivity | 1165f5f | 2007-04-19 17:27:43 +0300 | [diff] [blame] | 430 | ++vcpu->stat.pf_fixed; |
Avi Kivity | 37a7d8b | 2007-01-05 16:36:56 -0800 | [diff] [blame] | 431 | kvm_mmu_audit(vcpu, "post page fault (fixed)"); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 432 | |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 433 | return write_pt; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 434 | } |
| 435 | |
| 436 | static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) |
| 437 | { |
| 438 | struct guest_walker walker; |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 439 | gpa_t gpa = UNMAPPED_GVA; |
| 440 | int r; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 441 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 442 | r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 443 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 444 | if (r) { |
Avi Kivity | 1755fbc | 2007-11-21 14:44:45 +0200 | [diff] [blame^] | 445 | gpa = gfn_to_gpa(walker.gfn); |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 446 | gpa |= vaddr & ~PAGE_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 447 | } |
| 448 | |
| 449 | return gpa; |
| 450 | } |
| 451 | |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 452 | static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, |
| 453 | struct kvm_mmu_page *sp) |
| 454 | { |
Avi Kivity | e5a4c8c | 2007-11-20 21:39:54 +0200 | [diff] [blame] | 455 | int i, offset = 0; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 456 | pt_element_t *gpt; |
Izik Eidus | 8a7ae05 | 2007-10-18 11:09:33 +0200 | [diff] [blame] | 457 | struct page *page; |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 458 | |
Avi Kivity | e5a4c8c | 2007-11-20 21:39:54 +0200 | [diff] [blame] | 459 | if (sp->role.metaphysical |
| 460 | || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) { |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 461 | nonpaging_prefetch_page(vcpu, sp); |
| 462 | return; |
| 463 | } |
| 464 | |
Avi Kivity | e5a4c8c | 2007-11-20 21:39:54 +0200 | [diff] [blame] | 465 | if (PTTYPE == 32) |
| 466 | offset = sp->role.quadrant << PT64_LEVEL_BITS; |
Izik Eidus | 8a7ae05 | 2007-10-18 11:09:33 +0200 | [diff] [blame] | 467 | page = gfn_to_page(vcpu->kvm, sp->gfn); |
| 468 | gpt = kmap_atomic(page, KM_USER0); |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 469 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) |
Avi Kivity | e5a4c8c | 2007-11-20 21:39:54 +0200 | [diff] [blame] | 470 | if (is_present_pte(gpt[offset + i])) |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 471 | sp->spt[i] = shadow_trap_nonpresent_pte; |
| 472 | else |
| 473 | sp->spt[i] = shadow_notrap_nonpresent_pte; |
| 474 | kunmap_atomic(gpt, KM_USER0); |
Izik Eidus | b4231d6 | 2007-11-20 11:49:33 +0200 | [diff] [blame] | 475 | kvm_release_page_clean(page); |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 476 | } |
| 477 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 478 | #undef pt_element_t |
| 479 | #undef guest_walker |
| 480 | #undef FNAME |
| 481 | #undef PT_BASE_ADDR_MASK |
| 482 | #undef PT_INDEX |
| 483 | #undef SHADOW_PT_INDEX |
| 484 | #undef PT_LEVEL_MASK |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 485 | #undef PT_DIR_BASE_ADDR_MASK |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 486 | #undef PT_LEVEL_BITS |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 487 | #undef PT_MAX_FULL_LEVELS |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 488 | #undef gpte_to_gfn |
| 489 | #undef gpte_to_gfn_pde |