Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Kernel-based Virtual Machine driver for Linux |
| 3 | * |
| 4 | * This module enables machines with Intel VT-x extensions to run virtual |
| 5 | * machines without emulation or binary translation. |
| 6 | * |
| 7 | * MMU support |
| 8 | * |
| 9 | * Copyright (C) 2006 Qumranet, Inc. |
Nicolas Kaiser | 9611c18 | 2010-10-06 14:23:22 +0200 | [diff] [blame] | 10 | * Copyright 2010 Red Hat, Inc. and/or its affiliates. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 11 | * |
| 12 | * Authors: |
| 13 | * Yaniv Kamay <yaniv@qumranet.com> |
| 14 | * Avi Kivity <avi@qumranet.com> |
| 15 | * |
| 16 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 17 | * the COPYING file in the top-level directory. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | /* |
| 22 | * We need the mmu code to access both 32-bit and 64-bit guest ptes, |
| 23 | * so the code in this file is compiled twice, once per pte size. |
| 24 | */ |
| 25 | |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 26 | /* |
| 27 | * This is used to catch non optimized PT_GUEST_(DIRTY|ACCESS)_SHIFT macro |
| 28 | * uses for EPT without A/D paging type. |
| 29 | */ |
| 30 | extern u64 __pure __using_nonexistent_pte_bit(void) |
| 31 | __compiletime_error("wrong use of PT_GUEST_(DIRTY|ACCESS)_SHIFT"); |
| 32 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 33 | #if PTTYPE == 64 |
| 34 | #define pt_element_t u64 |
| 35 | #define guest_walker guest_walker64 |
| 36 | #define FNAME(name) paging##64_##name |
| 37 | #define PT_BASE_ADDR_MASK PT64_BASE_ADDR_MASK |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 38 | #define PT_LVL_ADDR_MASK(lvl) PT64_LVL_ADDR_MASK(lvl) |
| 39 | #define PT_LVL_OFFSET_MASK(lvl) PT64_LVL_OFFSET_MASK(lvl) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 40 | #define PT_INDEX(addr, level) PT64_INDEX(addr, level) |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 41 | #define PT_LEVEL_BITS PT64_LEVEL_BITS |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 42 | #define PT_GUEST_ACCESSED_MASK PT_ACCESSED_MASK |
| 43 | #define PT_GUEST_DIRTY_MASK PT_DIRTY_MASK |
| 44 | #define PT_GUEST_DIRTY_SHIFT PT_DIRTY_SHIFT |
| 45 | #define PT_GUEST_ACCESSED_SHIFT PT_ACCESSED_SHIFT |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 46 | #ifdef CONFIG_X86_64 |
| 47 | #define PT_MAX_FULL_LEVELS 4 |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 48 | #define CMPXCHG cmpxchg |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 49 | #else |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 50 | #define CMPXCHG cmpxchg64 |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 51 | #define PT_MAX_FULL_LEVELS 2 |
| 52 | #endif |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 53 | #elif PTTYPE == 32 |
| 54 | #define pt_element_t u32 |
| 55 | #define guest_walker guest_walker32 |
| 56 | #define FNAME(name) paging##32_##name |
| 57 | #define PT_BASE_ADDR_MASK PT32_BASE_ADDR_MASK |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 58 | #define PT_LVL_ADDR_MASK(lvl) PT32_LVL_ADDR_MASK(lvl) |
| 59 | #define PT_LVL_OFFSET_MASK(lvl) PT32_LVL_OFFSET_MASK(lvl) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 60 | #define PT_INDEX(addr, level) PT32_INDEX(addr, level) |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 61 | #define PT_LEVEL_BITS PT32_LEVEL_BITS |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 62 | #define PT_MAX_FULL_LEVELS 2 |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 63 | #define PT_GUEST_ACCESSED_MASK PT_ACCESSED_MASK |
| 64 | #define PT_GUEST_DIRTY_MASK PT_DIRTY_MASK |
| 65 | #define PT_GUEST_DIRTY_SHIFT PT_DIRTY_SHIFT |
| 66 | #define PT_GUEST_ACCESSED_SHIFT PT_ACCESSED_SHIFT |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 67 | #define CMPXCHG cmpxchg |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 68 | #elif PTTYPE == PTTYPE_EPT |
| 69 | #define pt_element_t u64 |
| 70 | #define guest_walker guest_walkerEPT |
| 71 | #define FNAME(name) ept_##name |
| 72 | #define PT_BASE_ADDR_MASK PT64_BASE_ADDR_MASK |
| 73 | #define PT_LVL_ADDR_MASK(lvl) PT64_LVL_ADDR_MASK(lvl) |
| 74 | #define PT_LVL_OFFSET_MASK(lvl) PT64_LVL_OFFSET_MASK(lvl) |
| 75 | #define PT_INDEX(addr, level) PT64_INDEX(addr, level) |
| 76 | #define PT_LEVEL_BITS PT64_LEVEL_BITS |
| 77 | #define PT_GUEST_ACCESSED_MASK 0 |
| 78 | #define PT_GUEST_DIRTY_MASK 0 |
| 79 | #define PT_GUEST_DIRTY_SHIFT __using_nonexistent_pte_bit() |
| 80 | #define PT_GUEST_ACCESSED_SHIFT __using_nonexistent_pte_bit() |
| 81 | #define CMPXCHG cmpxchg64 |
| 82 | #define PT_MAX_FULL_LEVELS 4 |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 83 | #else |
| 84 | #error Invalid PTTYPE value |
| 85 | #endif |
| 86 | |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 87 | #define gpte_to_gfn_lvl FNAME(gpte_to_gfn_lvl) |
| 88 | #define gpte_to_gfn(pte) gpte_to_gfn_lvl((pte), PT_PAGE_TABLE_LEVEL) |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 89 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 90 | /* |
| 91 | * The guest_walker structure emulates the behavior of the hardware page |
| 92 | * table walker. |
| 93 | */ |
| 94 | struct guest_walker { |
| 95 | int level; |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 96 | unsigned max_level; |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 97 | gfn_t table_gfn[PT_MAX_FULL_LEVELS]; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 98 | pt_element_t ptes[PT_MAX_FULL_LEVELS]; |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 99 | pt_element_t prefetch_ptes[PTE_PREFETCH_NUM]; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 100 | gpa_t pte_gpa[PT_MAX_FULL_LEVELS]; |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 101 | pt_element_t __user *ptep_user[PT_MAX_FULL_LEVELS]; |
Paolo Bonzini | ba6a354 | 2013-09-09 13:52:33 +0200 | [diff] [blame] | 102 | bool pte_writable[PT_MAX_FULL_LEVELS]; |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 103 | unsigned pt_access; |
| 104 | unsigned pte_access; |
Avi Kivity | 815af8d | 2007-01-05 16:36:44 -0800 | [diff] [blame] | 105 | gfn_t gfn; |
Avi Kivity | 8c28d03 | 2010-11-22 17:53:27 +0200 | [diff] [blame] | 106 | struct x86_exception fault; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 107 | }; |
| 108 | |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 109 | static gfn_t gpte_to_gfn_lvl(pt_element_t gpte, int lvl) |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 110 | { |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 111 | return (gpte & PT_LVL_ADDR_MASK(lvl)) >> PAGE_SHIFT; |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 112 | } |
| 113 | |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 114 | static inline void FNAME(protect_clean_gpte)(unsigned *access, unsigned gpte) |
| 115 | { |
| 116 | unsigned mask; |
| 117 | |
Gleb Natapov | 61719a8 | 2013-08-05 11:07:11 +0300 | [diff] [blame] | 118 | /* dirty bit is not supported, so no need to track it */ |
| 119 | if (!PT_GUEST_DIRTY_MASK) |
| 120 | return; |
| 121 | |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 122 | BUILD_BUG_ON(PT_WRITABLE_MASK != ACC_WRITE_MASK); |
| 123 | |
| 124 | mask = (unsigned)~ACC_WRITE_MASK; |
| 125 | /* Allow write access to dirty gptes */ |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 126 | mask |= (gpte >> (PT_GUEST_DIRTY_SHIFT - PT_WRITABLE_SHIFT)) & |
| 127 | PT_WRITABLE_MASK; |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 128 | *access &= mask; |
| 129 | } |
| 130 | |
| 131 | static bool FNAME(is_rsvd_bits_set)(struct kvm_mmu *mmu, u64 gpte, int level) |
| 132 | { |
Yang Zhang | 25d9208 | 2013-08-06 12:00:32 +0300 | [diff] [blame] | 133 | int bit7 = (gpte >> 7) & 1, low6 = gpte & 0x3f; |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 134 | |
Yang Zhang | 25d9208 | 2013-08-06 12:00:32 +0300 | [diff] [blame] | 135 | return (gpte & mmu->rsvd_bits_mask[bit7][level-1]) | |
| 136 | ((mmu->bad_mt_xwr & (1ull << low6)) != 0); |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 137 | } |
| 138 | |
| 139 | static inline int FNAME(is_present_gpte)(unsigned long pte) |
| 140 | { |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 141 | #if PTTYPE != PTTYPE_EPT |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 142 | return is_present_gpte(pte); |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 143 | #else |
| 144 | return pte & 7; |
| 145 | #endif |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 146 | } |
| 147 | |
Roedel, Joerg | a78484c | 2011-04-20 15:33:16 +0200 | [diff] [blame] | 148 | static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, |
Takuya Yoshikawa | c8cfbb5 | 2011-05-01 14:33:07 +0900 | [diff] [blame] | 149 | pt_element_t __user *ptep_user, unsigned index, |
| 150 | pt_element_t orig_pte, pt_element_t new_pte) |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 151 | { |
Takuya Yoshikawa | c8cfbb5 | 2011-05-01 14:33:07 +0900 | [diff] [blame] | 152 | int npages; |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 153 | pt_element_t ret; |
| 154 | pt_element_t *table; |
| 155 | struct page *page; |
| 156 | |
Takuya Yoshikawa | c8cfbb5 | 2011-05-01 14:33:07 +0900 | [diff] [blame] | 157 | npages = get_user_pages_fast((unsigned long)ptep_user, 1, 1, &page); |
| 158 | /* Check if the user is doing something meaningless. */ |
| 159 | if (unlikely(npages != 1)) |
Roedel, Joerg | a78484c | 2011-04-20 15:33:16 +0200 | [diff] [blame] | 160 | return -EFAULT; |
| 161 | |
Cong Wang | 8fd75e1 | 2011-11-25 23:14:17 +0800 | [diff] [blame] | 162 | table = kmap_atomic(page); |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 163 | ret = CMPXCHG(&table[index], orig_pte, new_pte); |
Cong Wang | 8fd75e1 | 2011-11-25 23:14:17 +0800 | [diff] [blame] | 164 | kunmap_atomic(table); |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 165 | |
| 166 | kvm_release_page_dirty(page); |
| 167 | |
| 168 | return (ret != orig_pte); |
| 169 | } |
| 170 | |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 171 | static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu, |
| 172 | struct kvm_mmu_page *sp, u64 *spte, |
| 173 | u64 gpte) |
| 174 | { |
| 175 | if (FNAME(is_rsvd_bits_set)(&vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL)) |
| 176 | goto no_present; |
| 177 | |
| 178 | if (!FNAME(is_present_gpte)(gpte)) |
| 179 | goto no_present; |
| 180 | |
Gleb Natapov | 61719a8 | 2013-08-05 11:07:11 +0300 | [diff] [blame] | 181 | /* if accessed bit is not supported prefetch non accessed gpte */ |
| 182 | if (PT_GUEST_ACCESSED_MASK && !(gpte & PT_GUEST_ACCESSED_MASK)) |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 183 | goto no_present; |
| 184 | |
| 185 | return false; |
| 186 | |
| 187 | no_present: |
| 188 | drop_spte(vcpu->kvm, spte); |
| 189 | return true; |
| 190 | } |
| 191 | |
| 192 | static inline unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, u64 gpte) |
| 193 | { |
| 194 | unsigned access; |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 195 | #if PTTYPE == PTTYPE_EPT |
| 196 | access = ((gpte & VMX_EPT_WRITABLE_MASK) ? ACC_WRITE_MASK : 0) | |
| 197 | ((gpte & VMX_EPT_EXECUTABLE_MASK) ? ACC_EXEC_MASK : 0) | |
| 198 | ACC_USER_MASK; |
| 199 | #else |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 200 | access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK; |
| 201 | access &= ~(gpte >> PT64_NX_SHIFT); |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 202 | #endif |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 203 | |
| 204 | return access; |
| 205 | } |
| 206 | |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 207 | static int FNAME(update_accessed_dirty_bits)(struct kvm_vcpu *vcpu, |
| 208 | struct kvm_mmu *mmu, |
| 209 | struct guest_walker *walker, |
| 210 | int write_fault) |
| 211 | { |
| 212 | unsigned level, index; |
| 213 | pt_element_t pte, orig_pte; |
| 214 | pt_element_t __user *ptep_user; |
| 215 | gfn_t table_gfn; |
| 216 | int ret; |
| 217 | |
Gleb Natapov | 61719a8 | 2013-08-05 11:07:11 +0300 | [diff] [blame] | 218 | /* dirty/accessed bits are not supported, so no need to update them */ |
| 219 | if (!PT_GUEST_DIRTY_MASK) |
| 220 | return 0; |
| 221 | |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 222 | for (level = walker->max_level; level >= walker->level; --level) { |
| 223 | pte = orig_pte = walker->ptes[level - 1]; |
| 224 | table_gfn = walker->table_gfn[level - 1]; |
| 225 | ptep_user = walker->ptep_user[level - 1]; |
| 226 | index = offset_in_page(ptep_user) / sizeof(pt_element_t); |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 227 | if (!(pte & PT_GUEST_ACCESSED_MASK)) { |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 228 | trace_kvm_mmu_set_accessed_bit(table_gfn, index, sizeof(pte)); |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 229 | pte |= PT_GUEST_ACCESSED_MASK; |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 230 | } |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 231 | if (level == walker->level && write_fault && |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 232 | !(pte & PT_GUEST_DIRTY_MASK)) { |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 233 | trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte)); |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 234 | pte |= PT_GUEST_DIRTY_MASK; |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 235 | } |
| 236 | if (pte == orig_pte) |
| 237 | continue; |
| 238 | |
Paolo Bonzini | ba6a354 | 2013-09-09 13:52:33 +0200 | [diff] [blame] | 239 | /* |
| 240 | * If the slot is read-only, simply do not process the accessed |
| 241 | * and dirty bits. This is the correct thing to do if the slot |
| 242 | * is ROM, and page tables in read-as-ROM/write-as-MMIO slots |
| 243 | * are only supported if the accessed and dirty bits are already |
| 244 | * set in the ROM (so that MMIO writes are never needed). |
| 245 | * |
| 246 | * Note that NPT does not allow this at all and faults, since |
| 247 | * it always wants nested page table entries for the guest |
| 248 | * page tables to be writable. And EPT works but will simply |
| 249 | * overwrite the read-only memory to set the accessed and dirty |
| 250 | * bits. |
| 251 | */ |
| 252 | if (unlikely(!walker->pte_writable[level - 1])) |
| 253 | continue; |
| 254 | |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 255 | ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index, orig_pte, pte); |
| 256 | if (ret) |
| 257 | return ret; |
| 258 | |
| 259 | mark_page_dirty(vcpu->kvm, table_gfn); |
| 260 | walker->ptes[level] = pte; |
| 261 | } |
| 262 | return 0; |
| 263 | } |
| 264 | |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 265 | /* |
| 266 | * Fetch a guest pte for a guest virtual address |
| 267 | */ |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 268 | static int FNAME(walk_addr_generic)(struct guest_walker *walker, |
| 269 | struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 270 | gva_t addr, u32 access) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 271 | { |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 272 | int ret; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 273 | pt_element_t pte; |
Borislav Petkov | b723363 | 2011-05-30 22:11:17 +0200 | [diff] [blame] | 274 | pt_element_t __user *uninitialized_var(ptep_user); |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 275 | gfn_t table_gfn; |
Gleb Natapov | b0cfeb5 | 2013-01-08 10:49:00 +0200 | [diff] [blame] | 276 | unsigned index, pt_access, pte_access, accessed_dirty; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 277 | gpa_t pte_gpa; |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 278 | int offset; |
| 279 | const int write_fault = access & PFERR_WRITE_MASK; |
| 280 | const int user_fault = access & PFERR_USER_MASK; |
| 281 | const int fetch_fault = access & PFERR_FETCH_MASK; |
| 282 | u16 errcode = 0; |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 283 | gpa_t real_gpa; |
| 284 | gfn_t gfn; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 285 | |
Xiao Guangrong | 6fbc277 | 2012-06-20 16:00:00 +0800 | [diff] [blame] | 286 | trace_kvm_mmu_pagetable_walk(addr, access); |
Takuya Yoshikawa | 92c1c1e | 2011-07-01 01:36:07 +0900 | [diff] [blame] | 287 | retry_walk: |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 288 | walker->level = mmu->root_level; |
| 289 | pte = mmu->get_cr3(vcpu); |
| 290 | |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 291 | #if PTTYPE == 64 |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 292 | if (walker->level == PT32E_ROOT_LEVEL) { |
Avi Kivity | e4e517b | 2011-07-28 11:36:17 +0300 | [diff] [blame] | 293 | pte = mmu->get_pdptr(vcpu, (addr >> 30) & 3); |
Avi Kivity | 0742017 | 2009-07-06 12:21:32 +0300 | [diff] [blame] | 294 | trace_kvm_mmu_paging_element(pte, walker->level); |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 295 | if (!FNAME(is_present_gpte)(pte)) |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 296 | goto error; |
Avi Kivity | 1b0973b | 2007-01-05 16:36:41 -0800 | [diff] [blame] | 297 | --walker->level; |
| 298 | } |
| 299 | #endif |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 300 | walker->max_level = walker->level; |
Avi Kivity | a9058ec | 2006-12-29 16:49:37 -0800 | [diff] [blame] | 301 | ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) || |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 302 | (mmu->get_cr3(vcpu) & CR3_NONPAE_RESERVED_BITS) == 0); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 303 | |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 304 | accessed_dirty = PT_GUEST_ACCESSED_MASK; |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 305 | pt_access = pte_access = ACC_ALL; |
| 306 | ++walker->level; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 307 | |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 308 | do { |
Takuya Yoshikawa | 6e2ca7d | 2011-04-22 00:34:44 +0900 | [diff] [blame] | 309 | gfn_t real_gfn; |
| 310 | unsigned long host_addr; |
| 311 | |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 312 | pt_access &= pte_access; |
| 313 | --walker->level; |
| 314 | |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 315 | index = PT_INDEX(addr, walker->level); |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 316 | |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 317 | table_gfn = gpte_to_gfn(pte); |
Joerg Roedel | 2329d46 | 2010-09-10 17:30:52 +0200 | [diff] [blame] | 318 | offset = index * sizeof(pt_element_t); |
| 319 | pte_gpa = gfn_to_gpa(table_gfn) + offset; |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 320 | walker->table_gfn[walker->level - 1] = table_gfn; |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 321 | walker->pte_gpa[walker->level - 1] = pte_gpa; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 322 | |
Takuya Yoshikawa | 6e2ca7d | 2011-04-22 00:34:44 +0900 | [diff] [blame] | 323 | real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn), |
| 324 | PFERR_USER_MASK|PFERR_WRITE_MASK); |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 325 | if (unlikely(real_gfn == UNMAPPED_GVA)) |
| 326 | goto error; |
Takuya Yoshikawa | 6e2ca7d | 2011-04-22 00:34:44 +0900 | [diff] [blame] | 327 | real_gfn = gpa_to_gfn(real_gfn); |
| 328 | |
Paolo Bonzini | ba6a354 | 2013-09-09 13:52:33 +0200 | [diff] [blame] | 329 | host_addr = gfn_to_hva_prot(vcpu->kvm, real_gfn, |
| 330 | &walker->pte_writable[walker->level - 1]); |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 331 | if (unlikely(kvm_is_error_hva(host_addr))) |
| 332 | goto error; |
Takuya Yoshikawa | 6e2ca7d | 2011-04-22 00:34:44 +0900 | [diff] [blame] | 333 | |
| 334 | ptep_user = (pt_element_t __user *)((void *)host_addr + offset); |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 335 | if (unlikely(__copy_from_user(&pte, ptep_user, sizeof(pte)))) |
| 336 | goto error; |
Avi Kivity | 8cbc706 | 2012-09-16 14:18:51 +0300 | [diff] [blame] | 337 | walker->ptep_user[walker->level - 1] = ptep_user; |
Marcelo Tosatti | a6085fb | 2010-01-14 17:41:27 -0200 | [diff] [blame] | 338 | |
Avi Kivity | 0742017 | 2009-07-06 12:21:32 +0300 | [diff] [blame] | 339 | trace_kvm_mmu_paging_element(pte, walker->level); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 340 | |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 341 | if (unlikely(!FNAME(is_present_gpte)(pte))) |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 342 | goto error; |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 343 | |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 344 | if (unlikely(FNAME(is_rsvd_bits_set)(mmu, pte, |
| 345 | walker->level))) { |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 346 | errcode |= PFERR_RSVD_MASK | PFERR_PRESENT_MASK; |
| 347 | goto error; |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 348 | } |
Dong, Eddie | 82725b2 | 2009-03-30 16:21:08 +0800 | [diff] [blame] | 349 | |
Avi Kivity | b514c30 | 2012-09-16 15:03:02 +0300 | [diff] [blame] | 350 | accessed_dirty &= pte; |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 351 | pte_access = pt_access & FNAME(gpte_access)(vcpu, pte); |
Avi Kivity | 73b1087 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 352 | |
Marcelo Tosatti | 7819026 | 2007-12-11 19:12:27 -0500 | [diff] [blame] | 353 | walker->ptes[walker->level - 1] = pte; |
Avi Kivity | 6fd01b7 | 2012-09-12 20:46:56 +0300 | [diff] [blame] | 354 | } while (!is_last_gpte(mmu, walker->level, pte)); |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 355 | |
Avi Kivity | 71331a1 | 2012-09-16 14:49:15 +0300 | [diff] [blame] | 356 | if (unlikely(permission_fault(mmu, pte_access, access))) { |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 357 | errcode |= PFERR_PRESENT_MASK; |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 358 | goto error; |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 359 | } |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 360 | |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 361 | gfn = gpte_to_gfn_lvl(pte, walker->level); |
| 362 | gfn += (addr & PT_LVL_OFFSET_MASK(walker->level)) >> PAGE_SHIFT; |
| 363 | |
| 364 | if (PTTYPE == 32 && walker->level == PT_DIRECTORY_LEVEL && is_cpuid_PSE36()) |
| 365 | gfn += pse36_gfn_delta(pte); |
| 366 | |
Avi Kivity | c542151 | 2012-09-19 19:33:48 +0300 | [diff] [blame] | 367 | real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access); |
Avi Kivity | 13d22b6 | 2012-09-12 15:12:09 +0300 | [diff] [blame] | 368 | if (real_gpa == UNMAPPED_GVA) |
| 369 | return 0; |
| 370 | |
| 371 | walker->gfn = real_gpa >> PAGE_SHIFT; |
| 372 | |
Avi Kivity | 8ea667f | 2012-09-12 13:44:53 +0300 | [diff] [blame] | 373 | if (!write_fault) |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 374 | FNAME(protect_clean_gpte)(&pte_access, pte); |
Gleb Natapov | 908e7d7 | 2012-12-27 14:44:58 +0200 | [diff] [blame] | 375 | else |
| 376 | /* |
Gleb Natapov | 61719a8 | 2013-08-05 11:07:11 +0300 | [diff] [blame] | 377 | * On a write fault, fold the dirty bit into accessed_dirty. |
| 378 | * For modes without A/D bits support accessed_dirty will be |
| 379 | * always clear. |
Gleb Natapov | 908e7d7 | 2012-12-27 14:44:58 +0200 | [diff] [blame] | 380 | */ |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 381 | accessed_dirty &= pte >> |
| 382 | (PT_GUEST_DIRTY_SHIFT - PT_GUEST_ACCESSED_SHIFT); |
Avi Kivity | b514c30 | 2012-09-16 15:03:02 +0300 | [diff] [blame] | 383 | |
| 384 | if (unlikely(!accessed_dirty)) { |
| 385 | ret = FNAME(update_accessed_dirty_bits)(vcpu, mmu, walker, write_fault); |
| 386 | if (unlikely(ret < 0)) |
| 387 | goto error; |
| 388 | else if (ret) |
| 389 | goto retry_walk; |
| 390 | } |
Avi Kivity | 42bf3f0 | 2007-10-17 12:18:47 +0200 | [diff] [blame] | 391 | |
Avi Kivity | fe135d2 | 2007-12-09 16:15:46 +0200 | [diff] [blame] | 392 | walker->pt_access = pt_access; |
| 393 | walker->pte_access = pte_access; |
| 394 | pgprintk("%s: pte %llx pte_access %x pt_access %x\n", |
Gui Jianfeng | 518c5a0 | 2010-05-05 09:58:33 +0800 | [diff] [blame] | 395 | __func__, (u64)pte, pte_access, pt_access); |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 396 | return 1; |
| 397 | |
Avi Kivity | f59c1d2 | 2010-07-06 16:20:43 +0300 | [diff] [blame] | 398 | error: |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 399 | errcode |= write_fault | user_fault; |
Yang, Wei Y | e57d4a3 | 2011-06-03 11:14:16 +0800 | [diff] [blame] | 400 | if (fetch_fault && (mmu->nx || |
| 401 | kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))) |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 402 | errcode |= PFERR_FETCH_MASK; |
Joerg Roedel | 8df25a3 | 2010-09-10 17:30:46 +0200 | [diff] [blame] | 403 | |
Takuya Yoshikawa | 134291b | 2011-07-01 01:34:56 +0900 | [diff] [blame] | 404 | walker->fault.vector = PF_VECTOR; |
| 405 | walker->fault.error_code_valid = true; |
| 406 | walker->fault.error_code = errcode; |
Yang Zhang | 25d9208 | 2013-08-06 12:00:32 +0300 | [diff] [blame] | 407 | |
| 408 | #if PTTYPE == PTTYPE_EPT |
| 409 | /* |
| 410 | * Use PFERR_RSVD_MASK in error_code to to tell if EPT |
| 411 | * misconfiguration requires to be injected. The detection is |
| 412 | * done by is_rsvd_bits_set() above. |
| 413 | * |
| 414 | * We set up the value of exit_qualification to inject: |
| 415 | * [2:0] - Derive from [2:0] of real exit_qualification at EPT violation |
| 416 | * [5:3] - Calculated by the page walk of the guest EPT page tables |
| 417 | * [7:8] - Derived from [7:8] of real exit_qualification |
| 418 | * |
| 419 | * The other bits are set to 0. |
| 420 | */ |
| 421 | if (!(errcode & PFERR_RSVD_MASK)) { |
| 422 | vcpu->arch.exit_qualification &= 0x187; |
| 423 | vcpu->arch.exit_qualification |= ((pt_access & pte) & 0x7) << 3; |
| 424 | } |
| 425 | #endif |
Avi Kivity | 6389ee9 | 2010-11-29 16:12:30 +0200 | [diff] [blame] | 426 | walker->fault.address = addr; |
| 427 | walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu; |
Joerg Roedel | 8df25a3 | 2010-09-10 17:30:46 +0200 | [diff] [blame] | 428 | |
Avi Kivity | 8c28d03 | 2010-11-22 17:53:27 +0200 | [diff] [blame] | 429 | trace_kvm_mmu_walker_error(walker->fault.error_code); |
Shaohua Li | fe55188 | 2007-07-23 14:51:39 +0800 | [diff] [blame] | 430 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 431 | } |
| 432 | |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 433 | static int FNAME(walk_addr)(struct guest_walker *walker, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 434 | struct kvm_vcpu *vcpu, gva_t addr, u32 access) |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 435 | { |
| 436 | return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.mmu, addr, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 437 | access); |
Joerg Roedel | 1e301fe | 2010-09-10 17:30:47 +0200 | [diff] [blame] | 438 | } |
| 439 | |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 440 | #if PTTYPE != PTTYPE_EPT |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 441 | static int FNAME(walk_addr_nested)(struct guest_walker *walker, |
| 442 | struct kvm_vcpu *vcpu, gva_t addr, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 443 | u32 access) |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 444 | { |
| 445 | return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.nested_mmu, |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 446 | addr, access); |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 447 | } |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 448 | #endif |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 449 | |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 450 | static bool |
| 451 | FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, |
| 452 | u64 *spte, pt_element_t gpte, bool no_dirty_log) |
| 453 | { |
| 454 | unsigned pte_access; |
| 455 | gfn_t gfn; |
| 456 | pfn_t pfn; |
| 457 | |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 458 | if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte)) |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 459 | return false; |
| 460 | |
| 461 | pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte); |
| 462 | |
| 463 | gfn = gpte_to_gfn(gpte); |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 464 | pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte); |
| 465 | FNAME(protect_clean_gpte)(&pte_access, gpte); |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 466 | pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn, |
| 467 | no_dirty_log && (pte_access & ACC_WRITE_MASK)); |
Xiao Guangrong | 81c52c5 | 2012-10-16 20:10:59 +0800 | [diff] [blame] | 468 | if (is_error_pfn(pfn)) |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 469 | return false; |
| 470 | |
| 471 | /* |
| 472 | * we call mmu_set_spte() with host_writable = true because |
| 473 | * pte_prefetch_gfn_to_pfn always gets a writable pfn. |
| 474 | */ |
Xiao Guangrong | f761620 | 2013-02-05 15:27:27 +0800 | [diff] [blame] | 475 | mmu_set_spte(vcpu, spte, pte_access, 0, NULL, PT_PAGE_TABLE_LEVEL, |
| 476 | gfn, pfn, true, true); |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 477 | |
| 478 | return true; |
| 479 | } |
| 480 | |
Xiao Guangrong | ac3cd03 | 2010-06-11 21:28:14 +0800 | [diff] [blame] | 481 | static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, |
Xiao Guangrong | 7c56252 | 2011-03-28 10:29:27 +0800 | [diff] [blame] | 482 | u64 *spte, const void *pte) |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 483 | { |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 484 | pt_element_t gpte = *(const pt_element_t *)pte; |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 485 | |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 486 | FNAME(prefetch_gpte)(vcpu, sp, spte, gpte, false); |
Avi Kivity | 0028425 | 2007-05-01 16:53:31 +0300 | [diff] [blame] | 487 | } |
| 488 | |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 489 | static bool FNAME(gpte_changed)(struct kvm_vcpu *vcpu, |
| 490 | struct guest_walker *gw, int level) |
| 491 | { |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 492 | pt_element_t curr_pte; |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 493 | gpa_t base_gpa, pte_gpa = gw->pte_gpa[level - 1]; |
| 494 | u64 mask; |
| 495 | int r, index; |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 496 | |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 497 | if (level == PT_PAGE_TABLE_LEVEL) { |
| 498 | mask = PTE_PREFETCH_NUM * sizeof(pt_element_t) - 1; |
| 499 | base_gpa = pte_gpa & ~mask; |
| 500 | index = (pte_gpa - base_gpa) / sizeof(pt_element_t); |
| 501 | |
| 502 | r = kvm_read_guest_atomic(vcpu->kvm, base_gpa, |
| 503 | gw->prefetch_ptes, sizeof(gw->prefetch_ptes)); |
| 504 | curr_pte = gw->prefetch_ptes[index]; |
| 505 | } else |
| 506 | r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 507 | &curr_pte, sizeof(curr_pte)); |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 508 | |
Avi Kivity | 39c8c67 | 2010-07-13 14:27:08 +0300 | [diff] [blame] | 509 | return r || curr_pte != gw->ptes[level - 1]; |
| 510 | } |
| 511 | |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 512 | static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, |
| 513 | u64 *sptep) |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 514 | { |
| 515 | struct kvm_mmu_page *sp; |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 516 | pt_element_t *gptep = gw->prefetch_ptes; |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 517 | u64 *spte; |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 518 | int i; |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 519 | |
| 520 | sp = page_header(__pa(sptep)); |
| 521 | |
| 522 | if (sp->role.level > PT_PAGE_TABLE_LEVEL) |
| 523 | return; |
| 524 | |
| 525 | if (sp->role.direct) |
| 526 | return __direct_pte_prefetch(vcpu, sp, sptep); |
| 527 | |
| 528 | i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 529 | spte = sp->spt + i; |
| 530 | |
| 531 | for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 532 | if (spte == sptep) |
| 533 | continue; |
| 534 | |
Xiao Guangrong | c370795 | 2011-07-12 03:28:04 +0800 | [diff] [blame] | 535 | if (is_shadow_present_pte(*spte)) |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 536 | continue; |
| 537 | |
Xiao Guangrong | bd6360c | 2012-10-16 20:10:12 +0800 | [diff] [blame] | 538 | if (!FNAME(prefetch_gpte)(vcpu, sp, spte, gptep[i], true)) |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 539 | break; |
Xiao Guangrong | 957ed9e | 2010-08-22 19:12:48 +0800 | [diff] [blame] | 540 | } |
| 541 | } |
| 542 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 543 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 544 | * Fetch a shadow pte for a specific level in the paging hierarchy. |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 545 | * If the guest tries to write a write-protected page, we need to |
| 546 | * emulate this operation, return 1 to indicate this case. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 547 | */ |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 548 | static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, |
Avi Kivity | e7a04c9 | 2008-12-25 15:10:50 +0200 | [diff] [blame] | 549 | struct guest_walker *gw, |
Xiao Guangrong | c2288505 | 2013-01-08 14:36:04 +0800 | [diff] [blame] | 550 | int write_fault, int hlevel, |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 551 | pfn_t pfn, bool map_writable, bool prefault) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 552 | { |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 553 | struct kvm_mmu_page *sp = NULL; |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 554 | struct kvm_shadow_walk_iterator it; |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 555 | unsigned direct_access, access = gw->pt_access; |
| 556 | int top_level, emulate = 0; |
Avi Kivity | ac79c97 | 2007-01-05 16:36:40 -0800 | [diff] [blame] | 557 | |
Xiao Guangrong | b36c7a7 | 2011-07-12 03:25:19 +0800 | [diff] [blame] | 558 | direct_access = gw->pte_access; |
Xiao Guangrong | 84754cd | 2010-06-30 16:05:00 +0800 | [diff] [blame] | 559 | |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 560 | top_level = vcpu->arch.mmu.root_level; |
| 561 | if (top_level == PT32E_ROOT_LEVEL) |
| 562 | top_level = PT32_ROOT_LEVEL; |
| 563 | /* |
| 564 | * Verify that the top-level gpte is still there. Since the page |
| 565 | * is a root page, it is either write protected (and cannot be |
| 566 | * changed from now on) or it is invalid (in which case, we don't |
| 567 | * really care if it changes underneath us after this point). |
| 568 | */ |
| 569 | if (FNAME(gpte_changed)(vcpu, gw, top_level)) |
| 570 | goto out_gpte_changed; |
| 571 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 572 | for (shadow_walk_init(&it, vcpu, addr); |
| 573 | shadow_walk_okay(&it) && it.level > gw->level; |
| 574 | shadow_walk_next(&it)) { |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 575 | gfn_t table_gfn; |
| 576 | |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 577 | clear_sp_write_flooding_count(it.sptep); |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 578 | drop_large_spte(vcpu, it.sptep); |
Avi Kivity | e7a04c9 | 2008-12-25 15:10:50 +0200 | [diff] [blame] | 579 | |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 580 | sp = NULL; |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 581 | if (!is_shadow_present_pte(*it.sptep)) { |
| 582 | table_gfn = gw->table_gfn[it.level - 2]; |
| 583 | sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1, |
| 584 | false, access, it.sptep); |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 585 | } |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 586 | |
| 587 | /* |
| 588 | * Verify that the gpte in the page we've just write |
| 589 | * protected is still there. |
| 590 | */ |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 591 | if (FNAME(gpte_changed)(vcpu, gw, it.level - 1)) |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 592 | goto out_gpte_changed; |
Avi Kivity | e7a04c9 | 2008-12-25 15:10:50 +0200 | [diff] [blame] | 593 | |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 594 | if (sp) |
Yang Zhang | 7a1638c | 2013-08-05 11:07:13 +0300 | [diff] [blame] | 595 | link_shadow_page(it.sptep, sp, PT_GUEST_ACCESSED_MASK); |
Avi Kivity | e7a04c9 | 2008-12-25 15:10:50 +0200 | [diff] [blame] | 596 | } |
| 597 | |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 598 | for (; |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 599 | shadow_walk_okay(&it) && it.level > hlevel; |
| 600 | shadow_walk_next(&it)) { |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 601 | gfn_t direct_gfn; |
| 602 | |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 603 | clear_sp_write_flooding_count(it.sptep); |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 604 | validate_direct_spte(vcpu, it.sptep, direct_access); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 605 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 606 | drop_large_spte(vcpu, it.sptep); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 607 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 608 | if (is_shadow_present_pte(*it.sptep)) |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 609 | continue; |
| 610 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 611 | direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 612 | |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 613 | sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1, |
| 614 | true, direct_access, it.sptep); |
Yang Zhang | 7a1638c | 2013-08-05 11:07:13 +0300 | [diff] [blame] | 615 | link_shadow_page(it.sptep, sp, PT_GUEST_ACCESSED_MASK); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 616 | } |
| 617 | |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 618 | clear_sp_write_flooding_count(it.sptep); |
Xiao Guangrong | f761620 | 2013-02-05 15:27:27 +0800 | [diff] [blame] | 619 | mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault, &emulate, |
| 620 | it.level, gw->gfn, pfn, prefault, map_writable); |
Xiao Guangrong | 189be38 | 2010-08-22 19:13:33 +0800 | [diff] [blame] | 621 | FNAME(pte_prefetch)(vcpu, gw, it.sptep); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 622 | |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 623 | return emulate; |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 624 | |
| 625 | out_gpte_changed: |
Avi Kivity | 5991b33 | 2010-07-13 14:27:10 +0300 | [diff] [blame] | 626 | if (sp) |
Avi Kivity | 24157aa | 2010-07-13 14:27:11 +0300 | [diff] [blame] | 627 | kvm_mmu_put_page(sp, it.sptep); |
Avi Kivity | 0b3c933 | 2010-07-13 14:27:09 +0300 | [diff] [blame] | 628 | kvm_release_pfn_clean(pfn); |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 629 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 630 | } |
| 631 | |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 632 | /* |
| 633 | * To see whether the mapped gfn can write its page table in the current |
| 634 | * mapping. |
| 635 | * |
| 636 | * It is the helper function of FNAME(page_fault). When guest uses large page |
| 637 | * size to map the writable gfn which is used as current page table, we should |
| 638 | * force kvm to use small page size to map it because new shadow page will be |
| 639 | * created when kvm establishes shadow page table that stop kvm using large |
| 640 | * page size. Do it early can avoid unnecessary #PF and emulation. |
| 641 | * |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 642 | * @write_fault_to_shadow_pgtable will return true if the fault gfn is |
| 643 | * currently used as its page table. |
| 644 | * |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 645 | * Note: the PDPT page table is not checked for PAE-32 bit guest. It is ok |
| 646 | * since the PDPT is always shadowed, that means, we can not use large page |
| 647 | * size to map the gfn which is used as PDPT. |
| 648 | */ |
| 649 | static bool |
| 650 | FNAME(is_self_change_mapping)(struct kvm_vcpu *vcpu, |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 651 | struct guest_walker *walker, int user_fault, |
| 652 | bool *write_fault_to_shadow_pgtable) |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 653 | { |
| 654 | int level; |
| 655 | gfn_t mask = ~(KVM_PAGES_PER_HPAGE(walker->level) - 1); |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 656 | bool self_changed = false; |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 657 | |
| 658 | if (!(walker->pte_access & ACC_WRITE_MASK || |
| 659 | (!is_write_protection(vcpu) && !user_fault))) |
| 660 | return false; |
| 661 | |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 662 | for (level = walker->level; level <= walker->max_level; level++) { |
| 663 | gfn_t gfn = walker->gfn ^ walker->table_gfn[level - 1]; |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 664 | |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 665 | self_changed |= !(gfn & mask); |
| 666 | *write_fault_to_shadow_pgtable |= !gfn; |
| 667 | } |
| 668 | |
| 669 | return self_changed; |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 670 | } |
| 671 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 672 | /* |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 673 | * Page fault handler. There are several causes for a page fault: |
| 674 | * - there is no shadow pte for the guest pte |
| 675 | * - write access through a shadow pte marked read only so that we can set |
| 676 | * the dirty bit |
| 677 | * - write access to a shadow pte marked read only so we can update the page |
| 678 | * dirty bitmap, when userspace requests it |
| 679 | * - mmio access; in this case we will never install a present shadow pte |
| 680 | * - normal guest page fault due to the guest pte marked not present, not |
| 681 | * writable, or not executable |
| 682 | * |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 683 | * Returns: 1 if we need to emulate the instruction, 0 otherwise, or |
| 684 | * a negative value on error. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 685 | */ |
Gleb Natapov | 56028d0 | 2010-10-17 18:13:42 +0200 | [diff] [blame] | 686 | static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, |
Xiao Guangrong | 78b2c54 | 2010-12-07 10:48:06 +0800 | [diff] [blame] | 687 | bool prefault) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 688 | { |
| 689 | int write_fault = error_code & PFERR_WRITE_MASK; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 690 | int user_fault = error_code & PFERR_USER_MASK; |
| 691 | struct guest_walker walker; |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 692 | int r; |
Anthony Liguori | 35149e2 | 2008-04-02 14:46:56 -0500 | [diff] [blame] | 693 | pfn_t pfn; |
Joerg Roedel | 7e4e405 | 2009-07-27 16:30:46 +0200 | [diff] [blame] | 694 | int level = PT_PAGE_TABLE_LEVEL; |
Andrea Arcangeli | 936a5fe | 2011-01-13 15:46:48 -0800 | [diff] [blame] | 695 | int force_pt_level; |
Andrea Arcangeli | e930bff | 2008-07-25 16:24:52 +0200 | [diff] [blame] | 696 | unsigned long mmu_seq; |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 697 | bool map_writable, is_self_change_mapping; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 698 | |
Harvey Harrison | b8688d5 | 2008-03-03 12:59:56 -0800 | [diff] [blame] | 699 | pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 700 | |
Xiao Guangrong | f8f5594 | 2013-06-07 16:51:26 +0800 | [diff] [blame] | 701 | if (unlikely(error_code & PFERR_RSVD_MASK)) { |
| 702 | r = handle_mmio_page_fault(vcpu, addr, error_code, |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 703 | mmu_is_nested(vcpu)); |
Xiao Guangrong | f8f5594 | 2013-06-07 16:51:26 +0800 | [diff] [blame] | 704 | if (likely(r != RET_MMIO_PF_INVALID)) |
| 705 | return r; |
| 706 | }; |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 707 | |
Avi Kivity | e2dec93 | 2007-01-05 16:36:54 -0800 | [diff] [blame] | 708 | r = mmu_topup_memory_caches(vcpu); |
| 709 | if (r) |
| 710 | return r; |
Avi Kivity | 714b93d | 2007-01-05 16:36:53 -0800 | [diff] [blame] | 711 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 712 | /* |
Eddie Dong | a8b876b | 2009-03-26 15:28:40 +0800 | [diff] [blame] | 713 | * Look up the guest pte for the faulting address. |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 714 | */ |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 715 | r = FNAME(walk_addr)(&walker, vcpu, addr, error_code); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 716 | |
| 717 | /* |
| 718 | * The page is not mapped by the guest. Let the guest handle it. |
| 719 | */ |
Avi Kivity | 7993ba4 | 2007-01-26 00:56:41 -0800 | [diff] [blame] | 720 | if (!r) { |
Harvey Harrison | b8688d5 | 2008-03-03 12:59:56 -0800 | [diff] [blame] | 721 | pgprintk("%s: guest page fault\n", __func__); |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 722 | if (!prefault) |
Xiao Guangrong | fb67e14 | 2010-12-07 10:35:25 +0800 | [diff] [blame] | 723 | inject_page_fault(vcpu, &walker.fault); |
Xiao Guangrong | a30f47c | 2011-09-22 16:58:36 +0800 | [diff] [blame] | 724 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 725 | return 0; |
| 726 | } |
| 727 | |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 728 | vcpu->arch.write_fault_to_shadow_pgtable = false; |
| 729 | |
| 730 | is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu, |
| 731 | &walker, user_fault, &vcpu->arch.write_fault_to_shadow_pgtable); |
| 732 | |
Andrea Arcangeli | 936a5fe | 2011-01-13 15:46:48 -0800 | [diff] [blame] | 733 | if (walker.level >= PT_DIRECTORY_LEVEL) |
Xiao Guangrong | 7751bab | 2013-01-08 14:36:51 +0800 | [diff] [blame] | 734 | force_pt_level = mapping_level_dirty_bitmap(vcpu, walker.gfn) |
Xiao Guangrong | 93c05d3 | 2013-01-13 23:49:07 +0800 | [diff] [blame] | 735 | || is_self_change_mapping; |
Andrea Arcangeli | 936a5fe | 2011-01-13 15:46:48 -0800 | [diff] [blame] | 736 | else |
| 737 | force_pt_level = 1; |
| 738 | if (!force_pt_level) { |
Joerg Roedel | 7e4e405 | 2009-07-27 16:30:46 +0200 | [diff] [blame] | 739 | level = min(walker.level, mapping_level(vcpu, walker.gfn)); |
| 740 | walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); |
Marcelo Tosatti | 05da455 | 2008-02-23 11:44:30 -0300 | [diff] [blame] | 741 | } |
Joerg Roedel | 7e4e405 | 2009-07-27 16:30:46 +0200 | [diff] [blame] | 742 | |
Andrea Arcangeli | e930bff | 2008-07-25 16:24:52 +0200 | [diff] [blame] | 743 | mmu_seq = vcpu->kvm->mmu_notifier_seq; |
Marcelo Tosatti | 4c2155c | 2008-09-16 20:54:47 -0300 | [diff] [blame] | 744 | smp_rmb(); |
Gleb Natapov | af585b9 | 2010-10-14 11:22:46 +0200 | [diff] [blame] | 745 | |
Xiao Guangrong | 78b2c54 | 2010-12-07 10:48:06 +0800 | [diff] [blame] | 746 | if (try_async_pf(vcpu, prefault, walker.gfn, addr, &pfn, write_fault, |
Marcelo Tosatti | 612819c | 2010-10-22 14:18:18 -0200 | [diff] [blame] | 747 | &map_writable)) |
Gleb Natapov | af585b9 | 2010-10-14 11:22:46 +0200 | [diff] [blame] | 748 | return 0; |
Avi Kivity | d7824ff | 2007-12-30 12:29:05 +0200 | [diff] [blame] | 749 | |
Xiao Guangrong | d7c5520 | 2011-07-12 03:29:38 +0800 | [diff] [blame] | 750 | if (handle_abnormal_pfn(vcpu, mmu_is_nested(vcpu) ? 0 : addr, |
| 751 | walker.gfn, pfn, walker.pte_access, &r)) |
| 752 | return r; |
| 753 | |
Xiao Guangrong | c2288505 | 2013-01-08 14:36:04 +0800 | [diff] [blame] | 754 | /* |
| 755 | * Do not change pte_access if the pfn is a mmio page, otherwise |
| 756 | * we will cache the incorrect access into mmio spte. |
| 757 | */ |
| 758 | if (write_fault && !(walker.pte_access & ACC_WRITE_MASK) && |
| 759 | !is_write_protection(vcpu) && !user_fault && |
| 760 | !is_noslot_pfn(pfn)) { |
| 761 | walker.pte_access |= ACC_WRITE_MASK; |
| 762 | walker.pte_access &= ~ACC_USER_MASK; |
| 763 | |
| 764 | /* |
| 765 | * If we converted a user page to a kernel page, |
| 766 | * so that the kernel can write to it when cr0.wp=0, |
| 767 | * then we should prevent the kernel from executing it |
| 768 | * if SMEP is enabled. |
| 769 | */ |
| 770 | if (kvm_read_cr4_bits(vcpu, X86_CR4_SMEP)) |
| 771 | walker.pte_access &= ~ACC_EXEC_MASK; |
| 772 | } |
| 773 | |
Marcelo Tosatti | aaee2c9 | 2007-12-20 19:18:26 -0500 | [diff] [blame] | 774 | spin_lock(&vcpu->kvm->mmu_lock); |
Christoffer Dall | 8ca40a7 | 2012-10-14 23:10:18 -0400 | [diff] [blame] | 775 | if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) |
Andrea Arcangeli | e930bff | 2008-07-25 16:24:52 +0200 | [diff] [blame] | 776 | goto out_unlock; |
Xiao Guangrong | bc32ce2 | 2010-08-28 19:22:46 +0800 | [diff] [blame] | 777 | |
Xiao Guangrong | 0375f7f | 2011-11-28 20:41:00 +0800 | [diff] [blame] | 778 | kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT); |
Takuya Yoshikawa | 450e0b4 | 2013-03-29 14:05:26 +0900 | [diff] [blame] | 779 | make_mmu_pages_available(vcpu); |
Andrea Arcangeli | 936a5fe | 2011-01-13 15:46:48 -0800 | [diff] [blame] | 780 | if (!force_pt_level) |
| 781 | transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level); |
Xiao Guangrong | c2288505 | 2013-01-08 14:36:04 +0800 | [diff] [blame] | 782 | r = FNAME(fetch)(vcpu, addr, &walker, write_fault, |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 783 | level, pfn, map_writable, prefault); |
Avi Kivity | 1165f5f | 2007-04-19 17:27:43 +0300 | [diff] [blame] | 784 | ++vcpu->stat.pf_fixed; |
Xiao Guangrong | 0375f7f | 2011-11-28 20:41:00 +0800 | [diff] [blame] | 785 | kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT); |
Marcelo Tosatti | aaee2c9 | 2007-12-20 19:18:26 -0500 | [diff] [blame] | 786 | spin_unlock(&vcpu->kvm->mmu_lock); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 787 | |
Xiao Guangrong | d4878f2 | 2012-10-16 20:08:43 +0800 | [diff] [blame] | 788 | return r; |
Andrea Arcangeli | e930bff | 2008-07-25 16:24:52 +0200 | [diff] [blame] | 789 | |
| 790 | out_unlock: |
| 791 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 792 | kvm_release_pfn_clean(pfn); |
| 793 | return 0; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 794 | } |
| 795 | |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 796 | static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp) |
| 797 | { |
| 798 | int offset = 0; |
| 799 | |
Davidlohr Bueso | f71fa31 | 2012-04-18 12:24:29 +0200 | [diff] [blame] | 800 | WARN_ON(sp->role.level != PT_PAGE_TABLE_LEVEL); |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 801 | |
| 802 | if (PTTYPE == 32) |
| 803 | offset = sp->role.quadrant << PT64_LEVEL_BITS; |
| 804 | |
| 805 | return gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t); |
| 806 | } |
| 807 | |
Marcelo Tosatti | a705289 | 2008-09-23 13:18:35 -0300 | [diff] [blame] | 808 | static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) |
| 809 | { |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 810 | struct kvm_shadow_walk_iterator iterator; |
Xiao Guangrong | f78978a | 2010-05-15 18:53:35 +0800 | [diff] [blame] | 811 | struct kvm_mmu_page *sp; |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 812 | int level; |
| 813 | u64 *sptep; |
Marcelo Tosatti | a705289 | 2008-09-23 13:18:35 -0300 | [diff] [blame] | 814 | |
Xiao Guangrong | bebb106 | 2011-07-12 03:23:20 +0800 | [diff] [blame] | 815 | vcpu_clear_mmio_info(vcpu, gva); |
| 816 | |
Xiao Guangrong | f57f2ef | 2011-09-22 16:56:39 +0800 | [diff] [blame] | 817 | /* |
| 818 | * No need to check return value here, rmap_can_add() can |
| 819 | * help us to skip pte prefetch later. |
| 820 | */ |
| 821 | mmu_topup_memory_caches(vcpu); |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 822 | |
Xiao Guangrong | f57f2ef | 2011-09-22 16:56:39 +0800 | [diff] [blame] | 823 | spin_lock(&vcpu->kvm->mmu_lock); |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 824 | for_each_shadow_entry(vcpu, gva, iterator) { |
| 825 | level = iterator.level; |
| 826 | sptep = iterator.sptep; |
| 827 | |
Xiao Guangrong | f78978a | 2010-05-15 18:53:35 +0800 | [diff] [blame] | 828 | sp = page_header(__pa(sptep)); |
Xiao Guangrong | 884a0ff | 2010-04-28 11:55:15 +0800 | [diff] [blame] | 829 | if (is_last_spte(*sptep, level)) { |
Xiao Guangrong | f57f2ef | 2011-09-22 16:56:39 +0800 | [diff] [blame] | 830 | pt_element_t gpte; |
| 831 | gpa_t pte_gpa; |
| 832 | |
Xiao Guangrong | f78978a | 2010-05-15 18:53:35 +0800 | [diff] [blame] | 833 | if (!sp->unsync) |
| 834 | break; |
| 835 | |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 836 | pte_gpa = FNAME(get_level1_sp_gpa)(sp); |
Avi Kivity | 08e850c | 2010-03-15 13:59:57 +0200 | [diff] [blame] | 837 | pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t); |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 838 | |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 839 | if (mmu_page_zap_pte(vcpu->kvm, sp, sptep)) |
| 840 | kvm_flush_remote_tlbs(vcpu->kvm); |
Xiao Guangrong | f57f2ef | 2011-09-22 16:56:39 +0800 | [diff] [blame] | 841 | |
| 842 | if (!rmap_can_add(vcpu)) |
| 843 | break; |
| 844 | |
| 845 | if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, |
| 846 | sizeof(pt_element_t))) |
| 847 | break; |
| 848 | |
| 849 | FNAME(update_pte)(vcpu, sp, sptep, &gpte); |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 850 | } |
| 851 | |
Xiao Guangrong | f78978a | 2010-05-15 18:53:35 +0800 | [diff] [blame] | 852 | if (!is_shadow_present_pte(*sptep) || !sp->unsync_children) |
Avi Kivity | a461930 | 2008-12-25 15:19:00 +0200 | [diff] [blame] | 853 | break; |
| 854 | } |
Marcelo Tosatti | ad218f8 | 2008-12-01 22:32:05 -0200 | [diff] [blame] | 855 | spin_unlock(&vcpu->kvm->mmu_lock); |
Marcelo Tosatti | a705289 | 2008-09-23 13:18:35 -0300 | [diff] [blame] | 856 | } |
| 857 | |
Gleb Natapov | 1871c60 | 2010-02-10 14:21:32 +0200 | [diff] [blame] | 858 | static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access, |
Avi Kivity | ab9ae31 | 2010-11-22 17:53:26 +0200 | [diff] [blame] | 859 | struct x86_exception *exception) |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 860 | { |
| 861 | struct guest_walker walker; |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 862 | gpa_t gpa = UNMAPPED_GVA; |
| 863 | int r; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 864 | |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 865 | r = FNAME(walk_addr)(&walker, vcpu, vaddr, access); |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 866 | |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 867 | if (r) { |
Avi Kivity | 1755fbc | 2007-11-21 14:44:45 +0200 | [diff] [blame] | 868 | gpa = gfn_to_gpa(walker.gfn); |
Avi Kivity | e119d11 | 2007-02-12 00:54:36 -0800 | [diff] [blame] | 869 | gpa |= vaddr & ~PAGE_MASK; |
Avi Kivity | 8c28d03 | 2010-11-22 17:53:27 +0200 | [diff] [blame] | 870 | } else if (exception) |
| 871 | *exception = walker.fault; |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 872 | |
| 873 | return gpa; |
| 874 | } |
| 875 | |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 876 | #if PTTYPE != PTTYPE_EPT |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 877 | static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gva_t vaddr, |
Avi Kivity | ab9ae31 | 2010-11-22 17:53:26 +0200 | [diff] [blame] | 878 | u32 access, |
| 879 | struct x86_exception *exception) |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 880 | { |
| 881 | struct guest_walker walker; |
| 882 | gpa_t gpa = UNMAPPED_GVA; |
| 883 | int r; |
| 884 | |
Xiao Guangrong | 3377078 | 2010-09-28 17:03:14 +0800 | [diff] [blame] | 885 | r = FNAME(walk_addr_nested)(&walker, vcpu, vaddr, access); |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 886 | |
| 887 | if (r) { |
| 888 | gpa = gfn_to_gpa(walker.gfn); |
| 889 | gpa |= vaddr & ~PAGE_MASK; |
Avi Kivity | 8c28d03 | 2010-11-22 17:53:27 +0200 | [diff] [blame] | 890 | } else if (exception) |
| 891 | *exception = walker.fault; |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 892 | |
| 893 | return gpa; |
| 894 | } |
Nadav Har'El | 37406aa | 2013-08-05 11:07:12 +0300 | [diff] [blame] | 895 | #endif |
Joerg Roedel | 6539e73 | 2010-09-10 17:30:50 +0200 | [diff] [blame] | 896 | |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 897 | /* |
| 898 | * Using the cached information from sp->gfns is safe because: |
| 899 | * - The spte has a reference to the struct page, so the pfn for a given gfn |
| 900 | * can't change unless all sptes pointing to it are nuked first. |
Xiao Guangrong | a4ee1ca | 2010-11-23 11:13:00 +0800 | [diff] [blame] | 901 | * |
| 902 | * Note: |
| 903 | * We should flush all tlbs if spte is dropped even though guest is |
| 904 | * responsible for it. Since if we don't, kvm_mmu_notifier_invalidate_page |
| 905 | * and kvm_mmu_notifier_invalidate_range_start detect the mapping page isn't |
| 906 | * used by guest then tlbs are not flushed, so guest is allowed to access the |
| 907 | * freed pages. |
| 908 | * And we increase kvm->tlbs_dirty to delay tlbs flush in this case. |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 909 | */ |
Xiao Guangrong | a4a8e6f | 2010-11-19 17:04:03 +0800 | [diff] [blame] | 910 | static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 911 | { |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 912 | int i, nr_present = 0; |
Lai Jiangshan | 9bdbba1 | 2010-11-19 17:03:22 +0800 | [diff] [blame] | 913 | bool host_writable; |
Gui Jianfeng | 51fb60d | 2010-04-16 17:16:40 +0800 | [diff] [blame] | 914 | gpa_t first_pte_gpa; |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 915 | |
Lai Jiangshan | 2032a93 | 2010-05-26 16:49:59 +0800 | [diff] [blame] | 916 | /* direct kvm_mmu_page can not be unsync. */ |
| 917 | BUG_ON(sp->role.direct); |
| 918 | |
Xiao Guangrong | 505aef8 | 2011-09-22 16:56:06 +0800 | [diff] [blame] | 919 | first_pte_gpa = FNAME(get_level1_sp_gpa)(sp); |
Gui Jianfeng | 51fb60d | 2010-04-16 17:16:40 +0800 | [diff] [blame] | 920 | |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 921 | for (i = 0; i < PT64_ENT_PER_PAGE; i++) { |
| 922 | unsigned pte_access; |
| 923 | pt_element_t gpte; |
| 924 | gpa_t pte_gpa; |
Xiao Guangrong | f55c3f4 | 2010-05-13 10:08:08 +0800 | [diff] [blame] | 925 | gfn_t gfn; |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 926 | |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 927 | if (!sp->spt[i]) |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 928 | continue; |
| 929 | |
Gui Jianfeng | 51fb60d | 2010-04-16 17:16:40 +0800 | [diff] [blame] | 930 | pte_gpa = first_pte_gpa + i * sizeof(pt_element_t); |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 931 | |
| 932 | if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, |
| 933 | sizeof(pt_element_t))) |
| 934 | return -EINVAL; |
| 935 | |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 936 | if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) { |
Xiao Guangrong | a4ee1ca | 2010-11-23 11:13:00 +0800 | [diff] [blame] | 937 | vcpu->kvm->tlbs_dirty++; |
Xiao Guangrong | 407c61c | 2010-11-23 11:08:42 +0800 | [diff] [blame] | 938 | continue; |
| 939 | } |
| 940 | |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 941 | gfn = gpte_to_gfn(gpte); |
| 942 | pte_access = sp->role.access; |
Nadav Har'El | 0ad805a | 2013-08-05 11:07:09 +0300 | [diff] [blame] | 943 | pte_access &= FNAME(gpte_access)(vcpu, gpte); |
| 944 | FNAME(protect_clean_gpte)(&pte_access, gpte); |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 945 | |
Xiao Guangrong | f2fd125 | 2013-06-07 16:51:24 +0800 | [diff] [blame] | 946 | if (sync_mmio_spte(vcpu->kvm, &sp->spt[i], gfn, pte_access, |
| 947 | &nr_present)) |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 948 | continue; |
| 949 | |
Xiao Guangrong | 407c61c | 2010-11-23 11:08:42 +0800 | [diff] [blame] | 950 | if (gfn != sp->gfns[i]) { |
Xiao Guangrong | c370795 | 2011-07-12 03:28:04 +0800 | [diff] [blame] | 951 | drop_spte(vcpu->kvm, &sp->spt[i]); |
Xiao Guangrong | a4ee1ca | 2010-11-23 11:13:00 +0800 | [diff] [blame] | 952 | vcpu->kvm->tlbs_dirty++; |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 953 | continue; |
| 954 | } |
| 955 | |
| 956 | nr_present++; |
Xiao Guangrong | ce88dec | 2011-07-12 03:33:44 +0800 | [diff] [blame] | 957 | |
Xiao Guangrong | f8e453b | 2010-12-23 16:09:29 +0800 | [diff] [blame] | 958 | host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE; |
| 959 | |
Xiao Guangrong | c2288505 | 2013-01-08 14:36:04 +0800 | [diff] [blame] | 960 | set_spte(vcpu, &sp->spt[i], pte_access, |
Xiao Guangrong | 640d9b0 | 2011-07-12 03:24:39 +0800 | [diff] [blame] | 961 | PT_PAGE_TABLE_LEVEL, gfn, |
Izik Eidus | 1403283 | 2009-09-23 21:47:17 +0300 | [diff] [blame] | 962 | spte_to_pfn(sp->spt[i]), true, false, |
Lai Jiangshan | 9bdbba1 | 2010-11-19 17:03:22 +0800 | [diff] [blame] | 963 | host_writable); |
Marcelo Tosatti | e8bc217 | 2008-09-23 13:18:33 -0300 | [diff] [blame] | 964 | } |
| 965 | |
| 966 | return !nr_present; |
| 967 | } |
| 968 | |
Avi Kivity | 6aa8b73 | 2006-12-10 02:21:36 -0800 | [diff] [blame] | 969 | #undef pt_element_t |
| 970 | #undef guest_walker |
| 971 | #undef FNAME |
| 972 | #undef PT_BASE_ADDR_MASK |
| 973 | #undef PT_INDEX |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 974 | #undef PT_LVL_ADDR_MASK |
| 975 | #undef PT_LVL_OFFSET_MASK |
Avi Kivity | c7addb9 | 2007-09-16 18:58:32 +0200 | [diff] [blame] | 976 | #undef PT_LEVEL_BITS |
Avi Kivity | cea0f0e | 2007-01-05 16:36:43 -0800 | [diff] [blame] | 977 | #undef PT_MAX_FULL_LEVELS |
Avi Kivity | 5fb07dd | 2007-11-21 12:35:07 +0200 | [diff] [blame] | 978 | #undef gpte_to_gfn |
Joerg Roedel | e04da98 | 2009-07-27 16:30:45 +0200 | [diff] [blame] | 979 | #undef gpte_to_gfn_lvl |
Marcelo Tosatti | b3e4e63 | 2007-12-07 07:56:58 -0500 | [diff] [blame] | 980 | #undef CMPXCHG |
Gleb Natapov | d8089ba | 2013-08-05 11:07:10 +0300 | [diff] [blame] | 981 | #undef PT_GUEST_ACCESSED_MASK |
| 982 | #undef PT_GUEST_DIRTY_MASK |
| 983 | #undef PT_GUEST_DIRTY_SHIFT |
| 984 | #undef PT_GUEST_ACCESSED_SHIFT |