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Commit | Line | Data |
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6aa8b732 AK |
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. | |
9611c187 | 10 | * Copyright 2010 Red Hat, Inc. and/or its affiliates. |
6aa8b732 AK |
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 | ||
37406aaa NHE |
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 | ||
6aa8b732 AK |
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 | |
e04da980 JR |
38 | #define PT_LVL_ADDR_MASK(lvl) PT64_LVL_ADDR_MASK(lvl) |
39 | #define PT_LVL_OFFSET_MASK(lvl) PT64_LVL_OFFSET_MASK(lvl) | |
6aa8b732 | 40 | #define PT_INDEX(addr, level) PT64_INDEX(addr, level) |
c7addb90 | 41 | #define PT_LEVEL_BITS PT64_LEVEL_BITS |
d8089bac GN |
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 | |
cea0f0e7 AK |
46 | #ifdef CONFIG_X86_64 |
47 | #define PT_MAX_FULL_LEVELS 4 | |
b3e4e63f | 48 | #define CMPXCHG cmpxchg |
cea0f0e7 | 49 | #else |
b3e4e63f | 50 | #define CMPXCHG cmpxchg64 |
cea0f0e7 AK |
51 | #define PT_MAX_FULL_LEVELS 2 |
52 | #endif | |
6aa8b732 AK |
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 | |
e04da980 JR |
58 | #define PT_LVL_ADDR_MASK(lvl) PT32_LVL_ADDR_MASK(lvl) |
59 | #define PT_LVL_OFFSET_MASK(lvl) PT32_LVL_OFFSET_MASK(lvl) | |
6aa8b732 | 60 | #define PT_INDEX(addr, level) PT32_INDEX(addr, level) |
c7addb90 | 61 | #define PT_LEVEL_BITS PT32_LEVEL_BITS |
cea0f0e7 | 62 | #define PT_MAX_FULL_LEVELS 2 |
d8089bac GN |
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 | |
b3e4e63f | 67 | #define CMPXCHG cmpxchg |
37406aaa NHE |
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 | |
6aa8b732 AK |
83 | #else |
84 | #error Invalid PTTYPE value | |
85 | #endif | |
86 | ||
e04da980 JR |
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) | |
5fb07ddb | 89 | |
6aa8b732 AK |
90 | /* |
91 | * The guest_walker structure emulates the behavior of the hardware page | |
92 | * table walker. | |
93 | */ | |
94 | struct guest_walker { | |
95 | int level; | |
8cbc7069 | 96 | unsigned max_level; |
cea0f0e7 | 97 | gfn_t table_gfn[PT_MAX_FULL_LEVELS]; |
7819026e | 98 | pt_element_t ptes[PT_MAX_FULL_LEVELS]; |
189be38d | 99 | pt_element_t prefetch_ptes[PTE_PREFETCH_NUM]; |
7819026e | 100 | gpa_t pte_gpa[PT_MAX_FULL_LEVELS]; |
8cbc7069 | 101 | pt_element_t __user *ptep_user[PT_MAX_FULL_LEVELS]; |
ba6a3541 | 102 | bool pte_writable[PT_MAX_FULL_LEVELS]; |
fe135d2c AK |
103 | unsigned pt_access; |
104 | unsigned pte_access; | |
815af8d4 | 105 | gfn_t gfn; |
8c28d031 | 106 | struct x86_exception fault; |
6aa8b732 AK |
107 | }; |
108 | ||
e04da980 | 109 | static gfn_t gpte_to_gfn_lvl(pt_element_t gpte, int lvl) |
5fb07ddb | 110 | { |
e04da980 | 111 | return (gpte & PT_LVL_ADDR_MASK(lvl)) >> PAGE_SHIFT; |
5fb07ddb AK |
112 | } |
113 | ||
0ad805a0 NHE |
114 | static inline void FNAME(protect_clean_gpte)(unsigned *access, unsigned gpte) |
115 | { | |
116 | unsigned mask; | |
117 | ||
61719a8f GN |
118 | /* dirty bit is not supported, so no need to track it */ |
119 | if (!PT_GUEST_DIRTY_MASK) | |
120 | return; | |
121 | ||
0ad805a0 NHE |
122 | BUILD_BUG_ON(PT_WRITABLE_MASK != ACC_WRITE_MASK); |
123 | ||
124 | mask = (unsigned)~ACC_WRITE_MASK; | |
125 | /* Allow write access to dirty gptes */ | |
d8089bac GN |
126 | mask |= (gpte >> (PT_GUEST_DIRTY_SHIFT - PT_WRITABLE_SHIFT)) & |
127 | PT_WRITABLE_MASK; | |
0ad805a0 NHE |
128 | *access &= mask; |
129 | } | |
130 | ||
131 | static bool FNAME(is_rsvd_bits_set)(struct kvm_mmu *mmu, u64 gpte, int level) | |
132 | { | |
25d92081 | 133 | int bit7 = (gpte >> 7) & 1, low6 = gpte & 0x3f; |
0ad805a0 | 134 | |
25d92081 YZ |
135 | return (gpte & mmu->rsvd_bits_mask[bit7][level-1]) | |
136 | ((mmu->bad_mt_xwr & (1ull << low6)) != 0); | |
0ad805a0 NHE |
137 | } |
138 | ||
139 | static inline int FNAME(is_present_gpte)(unsigned long pte) | |
140 | { | |
37406aaa | 141 | #if PTTYPE != PTTYPE_EPT |
0ad805a0 | 142 | return is_present_gpte(pte); |
37406aaa NHE |
143 | #else |
144 | return pte & 7; | |
145 | #endif | |
0ad805a0 NHE |
146 | } |
147 | ||
a78484c6 | 148 | static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, |
c8cfbb55 TY |
149 | pt_element_t __user *ptep_user, unsigned index, |
150 | pt_element_t orig_pte, pt_element_t new_pte) | |
b3e4e63f | 151 | { |
c8cfbb55 | 152 | int npages; |
b3e4e63f MT |
153 | pt_element_t ret; |
154 | pt_element_t *table; | |
155 | struct page *page; | |
156 | ||
c8cfbb55 TY |
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)) | |
a78484c6 RJ |
160 | return -EFAULT; |
161 | ||
8fd75e12 | 162 | table = kmap_atomic(page); |
b3e4e63f | 163 | ret = CMPXCHG(&table[index], orig_pte, new_pte); |
8fd75e12 | 164 | kunmap_atomic(table); |
b3e4e63f MT |
165 | |
166 | kvm_release_page_dirty(page); | |
167 | ||
168 | return (ret != orig_pte); | |
169 | } | |
170 | ||
0ad805a0 NHE |
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 | ||
61719a8f GN |
181 | /* if accessed bit is not supported prefetch non accessed gpte */ |
182 | if (PT_GUEST_ACCESSED_MASK && !(gpte & PT_GUEST_ACCESSED_MASK)) | |
0ad805a0 NHE |
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; | |
37406aaa NHE |
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 | |
0ad805a0 NHE |
200 | access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK; |
201 | access &= ~(gpte >> PT64_NX_SHIFT); | |
37406aaa | 202 | #endif |
0ad805a0 NHE |
203 | |
204 | return access; | |
205 | } | |
206 | ||
8cbc7069 AK |
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 | ||
61719a8f GN |
218 | /* dirty/accessed bits are not supported, so no need to update them */ |
219 | if (!PT_GUEST_DIRTY_MASK) | |
220 | return 0; | |
221 | ||
8cbc7069 AK |
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); | |
d8089bac | 227 | if (!(pte & PT_GUEST_ACCESSED_MASK)) { |
8cbc7069 | 228 | trace_kvm_mmu_set_accessed_bit(table_gfn, index, sizeof(pte)); |
d8089bac | 229 | pte |= PT_GUEST_ACCESSED_MASK; |
8cbc7069 | 230 | } |
0ad805a0 | 231 | if (level == walker->level && write_fault && |
d8089bac | 232 | !(pte & PT_GUEST_DIRTY_MASK)) { |
8cbc7069 | 233 | trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte)); |
d8089bac | 234 | pte |= PT_GUEST_DIRTY_MASK; |
8cbc7069 AK |
235 | } |
236 | if (pte == orig_pte) | |
237 | continue; | |
238 | ||
ba6a3541 PB |
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 | ||
8cbc7069 AK |
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 | ||
ac79c978 AK |
265 | /* |
266 | * Fetch a guest pte for a guest virtual address | |
267 | */ | |
1e301feb JR |
268 | static int FNAME(walk_addr_generic)(struct guest_walker *walker, |
269 | struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, | |
33770780 | 270 | gva_t addr, u32 access) |
6aa8b732 | 271 | { |
8cbc7069 | 272 | int ret; |
42bf3f0a | 273 | pt_element_t pte; |
b7233635 | 274 | pt_element_t __user *uninitialized_var(ptep_user); |
cea0f0e7 | 275 | gfn_t table_gfn; |
b0cfeb5d | 276 | unsigned index, pt_access, pte_access, accessed_dirty; |
42bf3f0a | 277 | gpa_t pte_gpa; |
134291bf TY |
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; | |
13d22b6a AK |
283 | gpa_t real_gpa; |
284 | gfn_t gfn; | |
6aa8b732 | 285 | |
6fbc2770 | 286 | trace_kvm_mmu_pagetable_walk(addr, access); |
92c1c1e8 | 287 | retry_walk: |
1e301feb JR |
288 | walker->level = mmu->root_level; |
289 | pte = mmu->get_cr3(vcpu); | |
290 | ||
1b0973bd | 291 | #if PTTYPE == 64 |
1e301feb | 292 | if (walker->level == PT32E_ROOT_LEVEL) { |
e4e517b4 | 293 | pte = mmu->get_pdptr(vcpu, (addr >> 30) & 3); |
07420171 | 294 | trace_kvm_mmu_paging_element(pte, walker->level); |
0ad805a0 | 295 | if (!FNAME(is_present_gpte)(pte)) |
f59c1d2d | 296 | goto error; |
1b0973bd AK |
297 | --walker->level; |
298 | } | |
299 | #endif | |
8cbc7069 | 300 | walker->max_level = walker->level; |
1715d0dc | 301 | ASSERT(!(is_long_mode(vcpu) && !is_pae(vcpu))); |
6aa8b732 | 302 | |
d8089bac | 303 | accessed_dirty = PT_GUEST_ACCESSED_MASK; |
13d22b6a AK |
304 | pt_access = pte_access = ACC_ALL; |
305 | ++walker->level; | |
ac79c978 | 306 | |
13d22b6a | 307 | do { |
6e2ca7d1 TY |
308 | gfn_t real_gfn; |
309 | unsigned long host_addr; | |
310 | ||
13d22b6a AK |
311 | pt_access &= pte_access; |
312 | --walker->level; | |
313 | ||
42bf3f0a | 314 | index = PT_INDEX(addr, walker->level); |
ac79c978 | 315 | |
5fb07ddb | 316 | table_gfn = gpte_to_gfn(pte); |
2329d46d JR |
317 | offset = index * sizeof(pt_element_t); |
318 | pte_gpa = gfn_to_gpa(table_gfn) + offset; | |
42bf3f0a | 319 | walker->table_gfn[walker->level - 1] = table_gfn; |
7819026e | 320 | walker->pte_gpa[walker->level - 1] = pte_gpa; |
42bf3f0a | 321 | |
6e2ca7d1 | 322 | real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn), |
54987b7a PB |
323 | PFERR_USER_MASK|PFERR_WRITE_MASK, |
324 | &walker->fault); | |
5e352519 PB |
325 | |
326 | /* | |
327 | * FIXME: This can happen if emulation (for of an INS/OUTS | |
328 | * instruction) triggers a nested page fault. The exit | |
329 | * qualification / exit info field will incorrectly have | |
330 | * "guest page access" as the nested page fault's cause, | |
331 | * instead of "guest page structure access". To fix this, | |
332 | * the x86_exception struct should be augmented with enough | |
333 | * information to fix the exit_qualification or exit_info_1 | |
334 | * fields. | |
335 | */ | |
134291bf | 336 | if (unlikely(real_gfn == UNMAPPED_GVA)) |
54987b7a | 337 | return 0; |
5e352519 | 338 | |
6e2ca7d1 TY |
339 | real_gfn = gpa_to_gfn(real_gfn); |
340 | ||
ba6a3541 PB |
341 | host_addr = gfn_to_hva_prot(vcpu->kvm, real_gfn, |
342 | &walker->pte_writable[walker->level - 1]); | |
134291bf TY |
343 | if (unlikely(kvm_is_error_hva(host_addr))) |
344 | goto error; | |
6e2ca7d1 TY |
345 | |
346 | ptep_user = (pt_element_t __user *)((void *)host_addr + offset); | |
134291bf TY |
347 | if (unlikely(__copy_from_user(&pte, ptep_user, sizeof(pte)))) |
348 | goto error; | |
8cbc7069 | 349 | walker->ptep_user[walker->level - 1] = ptep_user; |
a6085fba | 350 | |
07420171 | 351 | trace_kvm_mmu_paging_element(pte, walker->level); |
42bf3f0a | 352 | |
0ad805a0 | 353 | if (unlikely(!FNAME(is_present_gpte)(pte))) |
134291bf | 354 | goto error; |
7993ba43 | 355 | |
0ad805a0 NHE |
356 | if (unlikely(FNAME(is_rsvd_bits_set)(mmu, pte, |
357 | walker->level))) { | |
134291bf TY |
358 | errcode |= PFERR_RSVD_MASK | PFERR_PRESENT_MASK; |
359 | goto error; | |
f59c1d2d | 360 | } |
82725b20 | 361 | |
b514c30f | 362 | accessed_dirty &= pte; |
0ad805a0 | 363 | pte_access = pt_access & FNAME(gpte_access)(vcpu, pte); |
73b1087e | 364 | |
7819026e | 365 | walker->ptes[walker->level - 1] = pte; |
6fd01b71 | 366 | } while (!is_last_gpte(mmu, walker->level, pte)); |
42bf3f0a | 367 | |
97ec8c06 | 368 | if (unlikely(permission_fault(vcpu, mmu, pte_access, access))) { |
134291bf | 369 | errcode |= PFERR_PRESENT_MASK; |
f59c1d2d | 370 | goto error; |
134291bf | 371 | } |
f59c1d2d | 372 | |
13d22b6a AK |
373 | gfn = gpte_to_gfn_lvl(pte, walker->level); |
374 | gfn += (addr & PT_LVL_OFFSET_MASK(walker->level)) >> PAGE_SHIFT; | |
375 | ||
376 | if (PTTYPE == 32 && walker->level == PT_DIRECTORY_LEVEL && is_cpuid_PSE36()) | |
377 | gfn += pse36_gfn_delta(pte); | |
378 | ||
54987b7a | 379 | real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access, &walker->fault); |
13d22b6a AK |
380 | if (real_gpa == UNMAPPED_GVA) |
381 | return 0; | |
382 | ||
383 | walker->gfn = real_gpa >> PAGE_SHIFT; | |
384 | ||
8ea667f2 | 385 | if (!write_fault) |
0ad805a0 | 386 | FNAME(protect_clean_gpte)(&pte_access, pte); |
908e7d79 GN |
387 | else |
388 | /* | |
61719a8f GN |
389 | * On a write fault, fold the dirty bit into accessed_dirty. |
390 | * For modes without A/D bits support accessed_dirty will be | |
391 | * always clear. | |
908e7d79 | 392 | */ |
d8089bac GN |
393 | accessed_dirty &= pte >> |
394 | (PT_GUEST_DIRTY_SHIFT - PT_GUEST_ACCESSED_SHIFT); | |
b514c30f AK |
395 | |
396 | if (unlikely(!accessed_dirty)) { | |
397 | ret = FNAME(update_accessed_dirty_bits)(vcpu, mmu, walker, write_fault); | |
398 | if (unlikely(ret < 0)) | |
399 | goto error; | |
400 | else if (ret) | |
401 | goto retry_walk; | |
402 | } | |
42bf3f0a | 403 | |
fe135d2c AK |
404 | walker->pt_access = pt_access; |
405 | walker->pte_access = pte_access; | |
406 | pgprintk("%s: pte %llx pte_access %x pt_access %x\n", | |
518c5a05 | 407 | __func__, (u64)pte, pte_access, pt_access); |
7993ba43 AK |
408 | return 1; |
409 | ||
f59c1d2d | 410 | error: |
134291bf | 411 | errcode |= write_fault | user_fault; |
e57d4a35 YW |
412 | if (fetch_fault && (mmu->nx || |
413 | kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))) | |
134291bf | 414 | errcode |= PFERR_FETCH_MASK; |
8df25a32 | 415 | |
134291bf TY |
416 | walker->fault.vector = PF_VECTOR; |
417 | walker->fault.error_code_valid = true; | |
418 | walker->fault.error_code = errcode; | |
25d92081 YZ |
419 | |
420 | #if PTTYPE == PTTYPE_EPT | |
421 | /* | |
422 | * Use PFERR_RSVD_MASK in error_code to to tell if EPT | |
423 | * misconfiguration requires to be injected. The detection is | |
424 | * done by is_rsvd_bits_set() above. | |
425 | * | |
426 | * We set up the value of exit_qualification to inject: | |
427 | * [2:0] - Derive from [2:0] of real exit_qualification at EPT violation | |
428 | * [5:3] - Calculated by the page walk of the guest EPT page tables | |
429 | * [7:8] - Derived from [7:8] of real exit_qualification | |
430 | * | |
431 | * The other bits are set to 0. | |
432 | */ | |
433 | if (!(errcode & PFERR_RSVD_MASK)) { | |
434 | vcpu->arch.exit_qualification &= 0x187; | |
435 | vcpu->arch.exit_qualification |= ((pt_access & pte) & 0x7) << 3; | |
436 | } | |
437 | #endif | |
6389ee94 AK |
438 | walker->fault.address = addr; |
439 | walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu; | |
8df25a32 | 440 | |
8c28d031 | 441 | trace_kvm_mmu_walker_error(walker->fault.error_code); |
fe551881 | 442 | return 0; |
6aa8b732 AK |
443 | } |
444 | ||
1e301feb | 445 | static int FNAME(walk_addr)(struct guest_walker *walker, |
33770780 | 446 | struct kvm_vcpu *vcpu, gva_t addr, u32 access) |
1e301feb JR |
447 | { |
448 | return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.mmu, addr, | |
33770780 | 449 | access); |
1e301feb JR |
450 | } |
451 | ||
37406aaa | 452 | #if PTTYPE != PTTYPE_EPT |
6539e738 JR |
453 | static int FNAME(walk_addr_nested)(struct guest_walker *walker, |
454 | struct kvm_vcpu *vcpu, gva_t addr, | |
33770780 | 455 | u32 access) |
6539e738 JR |
456 | { |
457 | return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.nested_mmu, | |
33770780 | 458 | addr, access); |
6539e738 | 459 | } |
37406aaa | 460 | #endif |
6539e738 | 461 | |
bd6360cc XG |
462 | static bool |
463 | FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, | |
464 | u64 *spte, pt_element_t gpte, bool no_dirty_log) | |
0028425f | 465 | { |
41074d07 | 466 | unsigned pte_access; |
bd6360cc | 467 | gfn_t gfn; |
35149e21 | 468 | pfn_t pfn; |
0028425f | 469 | |
0ad805a0 | 470 | if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte)) |
bd6360cc | 471 | return false; |
407c61c6 | 472 | |
b8688d51 | 473 | pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte); |
bd6360cc XG |
474 | |
475 | gfn = gpte_to_gfn(gpte); | |
0ad805a0 NHE |
476 | pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte); |
477 | FNAME(protect_clean_gpte)(&pte_access, gpte); | |
bd6360cc XG |
478 | pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn, |
479 | no_dirty_log && (pte_access & ACC_WRITE_MASK)); | |
81c52c56 | 480 | if (is_error_pfn(pfn)) |
bd6360cc | 481 | return false; |
0f53b5b1 | 482 | |
1403283a | 483 | /* |
bd6360cc XG |
484 | * we call mmu_set_spte() with host_writable = true because |
485 | * pte_prefetch_gfn_to_pfn always gets a writable pfn. | |
1403283a | 486 | */ |
f7616203 XG |
487 | mmu_set_spte(vcpu, spte, pte_access, 0, NULL, PT_PAGE_TABLE_LEVEL, |
488 | gfn, pfn, true, true); | |
bd6360cc XG |
489 | |
490 | return true; | |
491 | } | |
492 | ||
493 | static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, | |
494 | u64 *spte, const void *pte) | |
495 | { | |
496 | pt_element_t gpte = *(const pt_element_t *)pte; | |
497 | ||
498 | FNAME(prefetch_gpte)(vcpu, sp, spte, gpte, false); | |
0028425f AK |
499 | } |
500 | ||
39c8c672 AK |
501 | static bool FNAME(gpte_changed)(struct kvm_vcpu *vcpu, |
502 | struct guest_walker *gw, int level) | |
503 | { | |
39c8c672 | 504 | pt_element_t curr_pte; |
189be38d XG |
505 | gpa_t base_gpa, pte_gpa = gw->pte_gpa[level - 1]; |
506 | u64 mask; | |
507 | int r, index; | |
508 | ||
509 | if (level == PT_PAGE_TABLE_LEVEL) { | |
510 | mask = PTE_PREFETCH_NUM * sizeof(pt_element_t) - 1; | |
511 | base_gpa = pte_gpa & ~mask; | |
512 | index = (pte_gpa - base_gpa) / sizeof(pt_element_t); | |
513 | ||
514 | r = kvm_read_guest_atomic(vcpu->kvm, base_gpa, | |
515 | gw->prefetch_ptes, sizeof(gw->prefetch_ptes)); | |
516 | curr_pte = gw->prefetch_ptes[index]; | |
517 | } else | |
518 | r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, | |
39c8c672 | 519 | &curr_pte, sizeof(curr_pte)); |
189be38d | 520 | |
39c8c672 AK |
521 | return r || curr_pte != gw->ptes[level - 1]; |
522 | } | |
523 | ||
189be38d XG |
524 | static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, |
525 | u64 *sptep) | |
957ed9ef XG |
526 | { |
527 | struct kvm_mmu_page *sp; | |
189be38d | 528 | pt_element_t *gptep = gw->prefetch_ptes; |
957ed9ef | 529 | u64 *spte; |
189be38d | 530 | int i; |
957ed9ef XG |
531 | |
532 | sp = page_header(__pa(sptep)); | |
533 | ||
534 | if (sp->role.level > PT_PAGE_TABLE_LEVEL) | |
535 | return; | |
536 | ||
537 | if (sp->role.direct) | |
538 | return __direct_pte_prefetch(vcpu, sp, sptep); | |
539 | ||
540 | i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); | |
957ed9ef XG |
541 | spte = sp->spt + i; |
542 | ||
543 | for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { | |
957ed9ef XG |
544 | if (spte == sptep) |
545 | continue; | |
546 | ||
c3707958 | 547 | if (is_shadow_present_pte(*spte)) |
957ed9ef XG |
548 | continue; |
549 | ||
bd6360cc | 550 | if (!FNAME(prefetch_gpte)(vcpu, sp, spte, gptep[i], true)) |
957ed9ef | 551 | break; |
957ed9ef XG |
552 | } |
553 | } | |
554 | ||
6aa8b732 AK |
555 | /* |
556 | * Fetch a shadow pte for a specific level in the paging hierarchy. | |
d4878f24 XG |
557 | * If the guest tries to write a write-protected page, we need to |
558 | * emulate this operation, return 1 to indicate this case. | |
6aa8b732 | 559 | */ |
d4878f24 | 560 | static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, |
e7a04c99 | 561 | struct guest_walker *gw, |
c2288505 | 562 | int write_fault, int hlevel, |
d4878f24 | 563 | pfn_t pfn, bool map_writable, bool prefault) |
6aa8b732 | 564 | { |
5991b332 | 565 | struct kvm_mmu_page *sp = NULL; |
24157aaf | 566 | struct kvm_shadow_walk_iterator it; |
d4878f24 XG |
567 | unsigned direct_access, access = gw->pt_access; |
568 | int top_level, emulate = 0; | |
abb9e0b8 | 569 | |
b36c7a7c | 570 | direct_access = gw->pte_access; |
84754cd8 | 571 | |
5991b332 AK |
572 | top_level = vcpu->arch.mmu.root_level; |
573 | if (top_level == PT32E_ROOT_LEVEL) | |
574 | top_level = PT32_ROOT_LEVEL; | |
575 | /* | |
576 | * Verify that the top-level gpte is still there. Since the page | |
577 | * is a root page, it is either write protected (and cannot be | |
578 | * changed from now on) or it is invalid (in which case, we don't | |
579 | * really care if it changes underneath us after this point). | |
580 | */ | |
581 | if (FNAME(gpte_changed)(vcpu, gw, top_level)) | |
582 | goto out_gpte_changed; | |
583 | ||
37f6a4e2 MT |
584 | if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) |
585 | goto out_gpte_changed; | |
586 | ||
24157aaf AK |
587 | for (shadow_walk_init(&it, vcpu, addr); |
588 | shadow_walk_okay(&it) && it.level > gw->level; | |
589 | shadow_walk_next(&it)) { | |
0b3c9333 AK |
590 | gfn_t table_gfn; |
591 | ||
a30f47cb | 592 | clear_sp_write_flooding_count(it.sptep); |
24157aaf | 593 | drop_large_spte(vcpu, it.sptep); |
ef0197e8 | 594 | |
5991b332 | 595 | sp = NULL; |
24157aaf AK |
596 | if (!is_shadow_present_pte(*it.sptep)) { |
597 | table_gfn = gw->table_gfn[it.level - 2]; | |
598 | sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1, | |
599 | false, access, it.sptep); | |
5991b332 | 600 | } |
0b3c9333 AK |
601 | |
602 | /* | |
603 | * Verify that the gpte in the page we've just write | |
604 | * protected is still there. | |
605 | */ | |
24157aaf | 606 | if (FNAME(gpte_changed)(vcpu, gw, it.level - 1)) |
0b3c9333 | 607 | goto out_gpte_changed; |
abb9e0b8 | 608 | |
5991b332 | 609 | if (sp) |
7a1638ce | 610 | link_shadow_page(it.sptep, sp, PT_GUEST_ACCESSED_MASK); |
e7a04c99 | 611 | } |
050e6499 | 612 | |
0b3c9333 | 613 | for (; |
24157aaf AK |
614 | shadow_walk_okay(&it) && it.level > hlevel; |
615 | shadow_walk_next(&it)) { | |
0b3c9333 AK |
616 | gfn_t direct_gfn; |
617 | ||
a30f47cb | 618 | clear_sp_write_flooding_count(it.sptep); |
24157aaf | 619 | validate_direct_spte(vcpu, it.sptep, direct_access); |
0b3c9333 | 620 | |
24157aaf | 621 | drop_large_spte(vcpu, it.sptep); |
0b3c9333 | 622 | |
24157aaf | 623 | if (is_shadow_present_pte(*it.sptep)) |
0b3c9333 AK |
624 | continue; |
625 | ||
24157aaf | 626 | direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); |
0b3c9333 | 627 | |
24157aaf AK |
628 | sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1, |
629 | true, direct_access, it.sptep); | |
7a1638ce | 630 | link_shadow_page(it.sptep, sp, PT_GUEST_ACCESSED_MASK); |
0b3c9333 AK |
631 | } |
632 | ||
a30f47cb | 633 | clear_sp_write_flooding_count(it.sptep); |
f7616203 XG |
634 | mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault, &emulate, |
635 | it.level, gw->gfn, pfn, prefault, map_writable); | |
189be38d | 636 | FNAME(pte_prefetch)(vcpu, gw, it.sptep); |
0b3c9333 | 637 | |
d4878f24 | 638 | return emulate; |
0b3c9333 AK |
639 | |
640 | out_gpte_changed: | |
5991b332 | 641 | if (sp) |
24157aaf | 642 | kvm_mmu_put_page(sp, it.sptep); |
0b3c9333 | 643 | kvm_release_pfn_clean(pfn); |
d4878f24 | 644 | return 0; |
6aa8b732 AK |
645 | } |
646 | ||
7751babd XG |
647 | /* |
648 | * To see whether the mapped gfn can write its page table in the current | |
649 | * mapping. | |
650 | * | |
651 | * It is the helper function of FNAME(page_fault). When guest uses large page | |
652 | * size to map the writable gfn which is used as current page table, we should | |
653 | * force kvm to use small page size to map it because new shadow page will be | |
654 | * created when kvm establishes shadow page table that stop kvm using large | |
655 | * page size. Do it early can avoid unnecessary #PF and emulation. | |
656 | * | |
93c05d3e XG |
657 | * @write_fault_to_shadow_pgtable will return true if the fault gfn is |
658 | * currently used as its page table. | |
659 | * | |
7751babd XG |
660 | * Note: the PDPT page table is not checked for PAE-32 bit guest. It is ok |
661 | * since the PDPT is always shadowed, that means, we can not use large page | |
662 | * size to map the gfn which is used as PDPT. | |
663 | */ | |
664 | static bool | |
665 | FNAME(is_self_change_mapping)(struct kvm_vcpu *vcpu, | |
93c05d3e XG |
666 | struct guest_walker *walker, int user_fault, |
667 | bool *write_fault_to_shadow_pgtable) | |
7751babd XG |
668 | { |
669 | int level; | |
670 | gfn_t mask = ~(KVM_PAGES_PER_HPAGE(walker->level) - 1); | |
93c05d3e | 671 | bool self_changed = false; |
7751babd XG |
672 | |
673 | if (!(walker->pte_access & ACC_WRITE_MASK || | |
674 | (!is_write_protection(vcpu) && !user_fault))) | |
675 | return false; | |
676 | ||
93c05d3e XG |
677 | for (level = walker->level; level <= walker->max_level; level++) { |
678 | gfn_t gfn = walker->gfn ^ walker->table_gfn[level - 1]; | |
679 | ||
680 | self_changed |= !(gfn & mask); | |
681 | *write_fault_to_shadow_pgtable |= !gfn; | |
682 | } | |
7751babd | 683 | |
93c05d3e | 684 | return self_changed; |
7751babd XG |
685 | } |
686 | ||
6aa8b732 AK |
687 | /* |
688 | * Page fault handler. There are several causes for a page fault: | |
689 | * - there is no shadow pte for the guest pte | |
690 | * - write access through a shadow pte marked read only so that we can set | |
691 | * the dirty bit | |
692 | * - write access to a shadow pte marked read only so we can update the page | |
693 | * dirty bitmap, when userspace requests it | |
694 | * - mmio access; in this case we will never install a present shadow pte | |
695 | * - normal guest page fault due to the guest pte marked not present, not | |
696 | * writable, or not executable | |
697 | * | |
e2dec939 AK |
698 | * Returns: 1 if we need to emulate the instruction, 0 otherwise, or |
699 | * a negative value on error. | |
6aa8b732 | 700 | */ |
56028d08 | 701 | static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, |
78b2c54a | 702 | bool prefault) |
6aa8b732 AK |
703 | { |
704 | int write_fault = error_code & PFERR_WRITE_MASK; | |
6aa8b732 AK |
705 | int user_fault = error_code & PFERR_USER_MASK; |
706 | struct guest_walker walker; | |
e2dec939 | 707 | int r; |
35149e21 | 708 | pfn_t pfn; |
7e4e4056 | 709 | int level = PT_PAGE_TABLE_LEVEL; |
936a5fe6 | 710 | int force_pt_level; |
e930bffe | 711 | unsigned long mmu_seq; |
93c05d3e | 712 | bool map_writable, is_self_change_mapping; |
6aa8b732 | 713 | |
b8688d51 | 714 | pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); |
714b93da | 715 | |
f8f55942 XG |
716 | if (unlikely(error_code & PFERR_RSVD_MASK)) { |
717 | r = handle_mmio_page_fault(vcpu, addr, error_code, | |
ce88decf | 718 | mmu_is_nested(vcpu)); |
f8f55942 XG |
719 | if (likely(r != RET_MMIO_PF_INVALID)) |
720 | return r; | |
721 | }; | |
ce88decf | 722 | |
e2dec939 AK |
723 | r = mmu_topup_memory_caches(vcpu); |
724 | if (r) | |
725 | return r; | |
714b93da | 726 | |
6aa8b732 | 727 | /* |
a8b876b1 | 728 | * Look up the guest pte for the faulting address. |
6aa8b732 | 729 | */ |
33770780 | 730 | r = FNAME(walk_addr)(&walker, vcpu, addr, error_code); |
6aa8b732 AK |
731 | |
732 | /* | |
733 | * The page is not mapped by the guest. Let the guest handle it. | |
734 | */ | |
7993ba43 | 735 | if (!r) { |
b8688d51 | 736 | pgprintk("%s: guest page fault\n", __func__); |
a30f47cb | 737 | if (!prefault) |
fb67e14f | 738 | inject_page_fault(vcpu, &walker.fault); |
a30f47cb | 739 | |
6aa8b732 AK |
740 | return 0; |
741 | } | |
742 | ||
93c05d3e XG |
743 | vcpu->arch.write_fault_to_shadow_pgtable = false; |
744 | ||
745 | is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu, | |
746 | &walker, user_fault, &vcpu->arch.write_fault_to_shadow_pgtable); | |
747 | ||
936a5fe6 | 748 | if (walker.level >= PT_DIRECTORY_LEVEL) |
7751babd | 749 | force_pt_level = mapping_level_dirty_bitmap(vcpu, walker.gfn) |
93c05d3e | 750 | || is_self_change_mapping; |
936a5fe6 AA |
751 | else |
752 | force_pt_level = 1; | |
753 | if (!force_pt_level) { | |
7e4e4056 JR |
754 | level = min(walker.level, mapping_level(vcpu, walker.gfn)); |
755 | walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); | |
05da4558 | 756 | } |
7e4e4056 | 757 | |
e930bffe | 758 | mmu_seq = vcpu->kvm->mmu_notifier_seq; |
4c2155ce | 759 | smp_rmb(); |
af585b92 | 760 | |
78b2c54a | 761 | if (try_async_pf(vcpu, prefault, walker.gfn, addr, &pfn, write_fault, |
612819c3 | 762 | &map_writable)) |
af585b92 | 763 | return 0; |
d7824fff | 764 | |
d7c55201 XG |
765 | if (handle_abnormal_pfn(vcpu, mmu_is_nested(vcpu) ? 0 : addr, |
766 | walker.gfn, pfn, walker.pte_access, &r)) | |
767 | return r; | |
768 | ||
c2288505 XG |
769 | /* |
770 | * Do not change pte_access if the pfn is a mmio page, otherwise | |
771 | * we will cache the incorrect access into mmio spte. | |
772 | */ | |
773 | if (write_fault && !(walker.pte_access & ACC_WRITE_MASK) && | |
774 | !is_write_protection(vcpu) && !user_fault && | |
775 | !is_noslot_pfn(pfn)) { | |
776 | walker.pte_access |= ACC_WRITE_MASK; | |
777 | walker.pte_access &= ~ACC_USER_MASK; | |
778 | ||
779 | /* | |
780 | * If we converted a user page to a kernel page, | |
781 | * so that the kernel can write to it when cr0.wp=0, | |
782 | * then we should prevent the kernel from executing it | |
783 | * if SMEP is enabled. | |
784 | */ | |
785 | if (kvm_read_cr4_bits(vcpu, X86_CR4_SMEP)) | |
786 | walker.pte_access &= ~ACC_EXEC_MASK; | |
787 | } | |
788 | ||
aaee2c94 | 789 | spin_lock(&vcpu->kvm->mmu_lock); |
8ca40a70 | 790 | if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) |
e930bffe | 791 | goto out_unlock; |
bc32ce21 | 792 | |
0375f7fa | 793 | kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT); |
450e0b41 | 794 | make_mmu_pages_available(vcpu); |
936a5fe6 AA |
795 | if (!force_pt_level) |
796 | transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level); | |
c2288505 | 797 | r = FNAME(fetch)(vcpu, addr, &walker, write_fault, |
d4878f24 | 798 | level, pfn, map_writable, prefault); |
1165f5fe | 799 | ++vcpu->stat.pf_fixed; |
0375f7fa | 800 | kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT); |
aaee2c94 | 801 | spin_unlock(&vcpu->kvm->mmu_lock); |
6aa8b732 | 802 | |
d4878f24 | 803 | return r; |
e930bffe AA |
804 | |
805 | out_unlock: | |
806 | spin_unlock(&vcpu->kvm->mmu_lock); | |
807 | kvm_release_pfn_clean(pfn); | |
808 | return 0; | |
6aa8b732 AK |
809 | } |
810 | ||
505aef8f XG |
811 | static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp) |
812 | { | |
813 | int offset = 0; | |
814 | ||
f71fa31f | 815 | WARN_ON(sp->role.level != PT_PAGE_TABLE_LEVEL); |
505aef8f XG |
816 | |
817 | if (PTTYPE == 32) | |
818 | offset = sp->role.quadrant << PT64_LEVEL_BITS; | |
819 | ||
820 | return gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t); | |
821 | } | |
822 | ||
a461930b | 823 | static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) |
a7052897 | 824 | { |
a461930b | 825 | struct kvm_shadow_walk_iterator iterator; |
f78978aa | 826 | struct kvm_mmu_page *sp; |
a461930b AK |
827 | int level; |
828 | u64 *sptep; | |
829 | ||
bebb106a XG |
830 | vcpu_clear_mmio_info(vcpu, gva); |
831 | ||
f57f2ef5 XG |
832 | /* |
833 | * No need to check return value here, rmap_can_add() can | |
834 | * help us to skip pte prefetch later. | |
835 | */ | |
836 | mmu_topup_memory_caches(vcpu); | |
a7052897 | 837 | |
37f6a4e2 MT |
838 | if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) { |
839 | WARN_ON(1); | |
840 | return; | |
841 | } | |
842 | ||
f57f2ef5 | 843 | spin_lock(&vcpu->kvm->mmu_lock); |
a461930b AK |
844 | for_each_shadow_entry(vcpu, gva, iterator) { |
845 | level = iterator.level; | |
846 | sptep = iterator.sptep; | |
ad218f85 | 847 | |
f78978aa | 848 | sp = page_header(__pa(sptep)); |
884a0ff0 | 849 | if (is_last_spte(*sptep, level)) { |
f57f2ef5 XG |
850 | pt_element_t gpte; |
851 | gpa_t pte_gpa; | |
852 | ||
f78978aa XG |
853 | if (!sp->unsync) |
854 | break; | |
855 | ||
505aef8f | 856 | pte_gpa = FNAME(get_level1_sp_gpa)(sp); |
08e850c6 | 857 | pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t); |
a461930b | 858 | |
505aef8f XG |
859 | if (mmu_page_zap_pte(vcpu->kvm, sp, sptep)) |
860 | kvm_flush_remote_tlbs(vcpu->kvm); | |
f57f2ef5 XG |
861 | |
862 | if (!rmap_can_add(vcpu)) | |
863 | break; | |
864 | ||
865 | if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, | |
866 | sizeof(pt_element_t))) | |
867 | break; | |
868 | ||
869 | FNAME(update_pte)(vcpu, sp, sptep, &gpte); | |
87917239 | 870 | } |
a7052897 | 871 | |
f78978aa | 872 | if (!is_shadow_present_pte(*sptep) || !sp->unsync_children) |
a461930b AK |
873 | break; |
874 | } | |
ad218f85 | 875 | spin_unlock(&vcpu->kvm->mmu_lock); |
a7052897 MT |
876 | } |
877 | ||
1871c602 | 878 | static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access, |
ab9ae313 | 879 | struct x86_exception *exception) |
6aa8b732 AK |
880 | { |
881 | struct guest_walker walker; | |
e119d117 AK |
882 | gpa_t gpa = UNMAPPED_GVA; |
883 | int r; | |
6aa8b732 | 884 | |
33770780 | 885 | r = FNAME(walk_addr)(&walker, vcpu, vaddr, access); |
6aa8b732 | 886 | |
e119d117 | 887 | if (r) { |
1755fbcc | 888 | gpa = gfn_to_gpa(walker.gfn); |
e119d117 | 889 | gpa |= vaddr & ~PAGE_MASK; |
8c28d031 AK |
890 | } else if (exception) |
891 | *exception = walker.fault; | |
6aa8b732 AK |
892 | |
893 | return gpa; | |
894 | } | |
895 | ||
37406aaa | 896 | #if PTTYPE != PTTYPE_EPT |
6539e738 | 897 | static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gva_t vaddr, |
ab9ae313 AK |
898 | u32 access, |
899 | struct x86_exception *exception) | |
6539e738 JR |
900 | { |
901 | struct guest_walker walker; | |
902 | gpa_t gpa = UNMAPPED_GVA; | |
903 | int r; | |
904 | ||
33770780 | 905 | r = FNAME(walk_addr_nested)(&walker, vcpu, vaddr, access); |
6539e738 JR |
906 | |
907 | if (r) { | |
908 | gpa = gfn_to_gpa(walker.gfn); | |
909 | gpa |= vaddr & ~PAGE_MASK; | |
8c28d031 AK |
910 | } else if (exception) |
911 | *exception = walker.fault; | |
6539e738 JR |
912 | |
913 | return gpa; | |
914 | } | |
37406aaa | 915 | #endif |
6539e738 | 916 | |
e8bc217a MT |
917 | /* |
918 | * Using the cached information from sp->gfns is safe because: | |
919 | * - The spte has a reference to the struct page, so the pfn for a given gfn | |
920 | * can't change unless all sptes pointing to it are nuked first. | |
a4ee1ca4 XG |
921 | * |
922 | * Note: | |
923 | * We should flush all tlbs if spte is dropped even though guest is | |
924 | * responsible for it. Since if we don't, kvm_mmu_notifier_invalidate_page | |
925 | * and kvm_mmu_notifier_invalidate_range_start detect the mapping page isn't | |
926 | * used by guest then tlbs are not flushed, so guest is allowed to access the | |
927 | * freed pages. | |
a086f6a1 | 928 | * And we increase kvm->tlbs_dirty to delay tlbs flush in this case. |
e8bc217a | 929 | */ |
a4a8e6f7 | 930 | static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
e8bc217a | 931 | { |
505aef8f | 932 | int i, nr_present = 0; |
9bdbba13 | 933 | bool host_writable; |
51fb60d8 | 934 | gpa_t first_pte_gpa; |
e8bc217a | 935 | |
2032a93d LJ |
936 | /* direct kvm_mmu_page can not be unsync. */ |
937 | BUG_ON(sp->role.direct); | |
938 | ||
505aef8f | 939 | first_pte_gpa = FNAME(get_level1_sp_gpa)(sp); |
51fb60d8 | 940 | |
e8bc217a MT |
941 | for (i = 0; i < PT64_ENT_PER_PAGE; i++) { |
942 | unsigned pte_access; | |
943 | pt_element_t gpte; | |
944 | gpa_t pte_gpa; | |
f55c3f41 | 945 | gfn_t gfn; |
e8bc217a | 946 | |
ce88decf | 947 | if (!sp->spt[i]) |
e8bc217a MT |
948 | continue; |
949 | ||
51fb60d8 | 950 | pte_gpa = first_pte_gpa + i * sizeof(pt_element_t); |
e8bc217a MT |
951 | |
952 | if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, | |
953 | sizeof(pt_element_t))) | |
954 | return -EINVAL; | |
955 | ||
0ad805a0 | 956 | if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) { |
a086f6a1 | 957 | vcpu->kvm->tlbs_dirty++; |
407c61c6 XG |
958 | continue; |
959 | } | |
960 | ||
ce88decf XG |
961 | gfn = gpte_to_gfn(gpte); |
962 | pte_access = sp->role.access; | |
0ad805a0 NHE |
963 | pte_access &= FNAME(gpte_access)(vcpu, gpte); |
964 | FNAME(protect_clean_gpte)(&pte_access, gpte); | |
ce88decf | 965 | |
f2fd125d XG |
966 | if (sync_mmio_spte(vcpu->kvm, &sp->spt[i], gfn, pte_access, |
967 | &nr_present)) | |
ce88decf XG |
968 | continue; |
969 | ||
407c61c6 | 970 | if (gfn != sp->gfns[i]) { |
c3707958 | 971 | drop_spte(vcpu->kvm, &sp->spt[i]); |
a086f6a1 | 972 | vcpu->kvm->tlbs_dirty++; |
e8bc217a MT |
973 | continue; |
974 | } | |
975 | ||
976 | nr_present++; | |
ce88decf | 977 | |
f8e453b0 XG |
978 | host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE; |
979 | ||
c2288505 | 980 | set_spte(vcpu, &sp->spt[i], pte_access, |
640d9b0d | 981 | PT_PAGE_TABLE_LEVEL, gfn, |
1403283a | 982 | spte_to_pfn(sp->spt[i]), true, false, |
9bdbba13 | 983 | host_writable); |
e8bc217a MT |
984 | } |
985 | ||
986 | return !nr_present; | |
987 | } | |
988 | ||
6aa8b732 AK |
989 | #undef pt_element_t |
990 | #undef guest_walker | |
991 | #undef FNAME | |
992 | #undef PT_BASE_ADDR_MASK | |
993 | #undef PT_INDEX | |
e04da980 JR |
994 | #undef PT_LVL_ADDR_MASK |
995 | #undef PT_LVL_OFFSET_MASK | |
c7addb90 | 996 | #undef PT_LEVEL_BITS |
cea0f0e7 | 997 | #undef PT_MAX_FULL_LEVELS |
5fb07ddb | 998 | #undef gpte_to_gfn |
e04da980 | 999 | #undef gpte_to_gfn_lvl |
b3e4e63f | 1000 | #undef CMPXCHG |
d8089bac GN |
1001 | #undef PT_GUEST_ACCESSED_MASK |
1002 | #undef PT_GUEST_DIRTY_MASK | |
1003 | #undef PT_GUEST_DIRTY_SHIFT | |
1004 | #undef PT_GUEST_ACCESSED_SHIFT |