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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. | |
10 | * | |
11 | * Authors: | |
12 | * Yaniv Kamay <yaniv@qumranet.com> | |
13 | * Avi Kivity <avi@qumranet.com> | |
14 | * | |
15 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
16 | * the COPYING file in the top-level directory. | |
17 | * | |
18 | */ | |
19 | #include <linux/types.h> | |
20 | #include <linux/string.h> | |
21 | #include <asm/page.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/highmem.h> | |
24 | #include <linux/module.h> | |
25 | ||
26 | #include "vmx.h" | |
27 | #include "kvm.h" | |
28 | ||
29 | #define pgprintk(x...) do { } while (0) | |
30 | ||
31 | #define ASSERT(x) \ | |
32 | if (!(x)) { \ | |
33 | printk(KERN_WARNING "assertion failed %s:%d: %s\n", \ | |
34 | __FILE__, __LINE__, #x); \ | |
35 | } | |
36 | ||
37 | #define PT64_ENT_PER_PAGE 512 | |
38 | #define PT32_ENT_PER_PAGE 1024 | |
39 | ||
40 | #define PT_WRITABLE_SHIFT 1 | |
41 | ||
42 | #define PT_PRESENT_MASK (1ULL << 0) | |
43 | #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT) | |
44 | #define PT_USER_MASK (1ULL << 2) | |
45 | #define PT_PWT_MASK (1ULL << 3) | |
46 | #define PT_PCD_MASK (1ULL << 4) | |
47 | #define PT_ACCESSED_MASK (1ULL << 5) | |
48 | #define PT_DIRTY_MASK (1ULL << 6) | |
49 | #define PT_PAGE_SIZE_MASK (1ULL << 7) | |
50 | #define PT_PAT_MASK (1ULL << 7) | |
51 | #define PT_GLOBAL_MASK (1ULL << 8) | |
52 | #define PT64_NX_MASK (1ULL << 63) | |
53 | ||
54 | #define PT_PAT_SHIFT 7 | |
55 | #define PT_DIR_PAT_SHIFT 12 | |
56 | #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT) | |
57 | ||
58 | #define PT32_DIR_PSE36_SIZE 4 | |
59 | #define PT32_DIR_PSE36_SHIFT 13 | |
60 | #define PT32_DIR_PSE36_MASK (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT) | |
61 | ||
62 | ||
63 | #define PT32_PTE_COPY_MASK \ | |
8c7bb723 | 64 | (PT_PRESENT_MASK | PT_ACCESSED_MASK | PT_DIRTY_MASK | PT_GLOBAL_MASK) |
6aa8b732 | 65 | |
8c7bb723 | 66 | #define PT64_PTE_COPY_MASK (PT64_NX_MASK | PT32_PTE_COPY_MASK) |
6aa8b732 AK |
67 | |
68 | #define PT_FIRST_AVAIL_BITS_SHIFT 9 | |
69 | #define PT64_SECOND_AVAIL_BITS_SHIFT 52 | |
70 | ||
71 | #define PT_SHADOW_PS_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) | |
72 | #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) | |
73 | ||
74 | #define PT_SHADOW_WRITABLE_SHIFT (PT_FIRST_AVAIL_BITS_SHIFT + 1) | |
75 | #define PT_SHADOW_WRITABLE_MASK (1ULL << PT_SHADOW_WRITABLE_SHIFT) | |
76 | ||
77 | #define PT_SHADOW_USER_SHIFT (PT_SHADOW_WRITABLE_SHIFT + 1) | |
78 | #define PT_SHADOW_USER_MASK (1ULL << (PT_SHADOW_USER_SHIFT)) | |
79 | ||
80 | #define PT_SHADOW_BITS_OFFSET (PT_SHADOW_WRITABLE_SHIFT - PT_WRITABLE_SHIFT) | |
81 | ||
82 | #define VALID_PAGE(x) ((x) != INVALID_PAGE) | |
83 | ||
84 | #define PT64_LEVEL_BITS 9 | |
85 | ||
86 | #define PT64_LEVEL_SHIFT(level) \ | |
87 | ( PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS ) | |
88 | ||
89 | #define PT64_LEVEL_MASK(level) \ | |
90 | (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level)) | |
91 | ||
92 | #define PT64_INDEX(address, level)\ | |
93 | (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1)) | |
94 | ||
95 | ||
96 | #define PT32_LEVEL_BITS 10 | |
97 | ||
98 | #define PT32_LEVEL_SHIFT(level) \ | |
99 | ( PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS ) | |
100 | ||
101 | #define PT32_LEVEL_MASK(level) \ | |
102 | (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level)) | |
103 | ||
104 | #define PT32_INDEX(address, level)\ | |
105 | (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1)) | |
106 | ||
107 | ||
108 | #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & PAGE_MASK) | |
109 | #define PT64_DIR_BASE_ADDR_MASK \ | |
110 | (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1)) | |
111 | ||
112 | #define PT32_BASE_ADDR_MASK PAGE_MASK | |
113 | #define PT32_DIR_BASE_ADDR_MASK \ | |
114 | (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1)) | |
115 | ||
116 | ||
117 | #define PFERR_PRESENT_MASK (1U << 0) | |
118 | #define PFERR_WRITE_MASK (1U << 1) | |
119 | #define PFERR_USER_MASK (1U << 2) | |
120 | ||
121 | #define PT64_ROOT_LEVEL 4 | |
122 | #define PT32_ROOT_LEVEL 2 | |
123 | #define PT32E_ROOT_LEVEL 3 | |
124 | ||
125 | #define PT_DIRECTORY_LEVEL 2 | |
126 | #define PT_PAGE_TABLE_LEVEL 1 | |
127 | ||
128 | static int is_write_protection(struct kvm_vcpu *vcpu) | |
129 | { | |
130 | return vcpu->cr0 & CR0_WP_MASK; | |
131 | } | |
132 | ||
133 | static int is_cpuid_PSE36(void) | |
134 | { | |
135 | return 1; | |
136 | } | |
137 | ||
138 | static int is_present_pte(unsigned long pte) | |
139 | { | |
140 | return pte & PT_PRESENT_MASK; | |
141 | } | |
142 | ||
143 | static int is_writeble_pte(unsigned long pte) | |
144 | { | |
145 | return pte & PT_WRITABLE_MASK; | |
146 | } | |
147 | ||
148 | static int is_io_pte(unsigned long pte) | |
149 | { | |
150 | return pte & PT_SHADOW_IO_MARK; | |
151 | } | |
152 | ||
153 | static void kvm_mmu_free_page(struct kvm_vcpu *vcpu, hpa_t page_hpa) | |
154 | { | |
155 | struct kvm_mmu_page *page_head = page_header(page_hpa); | |
156 | ||
157 | list_del(&page_head->link); | |
158 | page_head->page_hpa = page_hpa; | |
159 | list_add(&page_head->link, &vcpu->free_pages); | |
160 | } | |
161 | ||
162 | static int is_empty_shadow_page(hpa_t page_hpa) | |
163 | { | |
164 | u32 *pos; | |
165 | u32 *end; | |
166 | for (pos = __va(page_hpa), end = pos + PAGE_SIZE / sizeof(u32); | |
167 | pos != end; pos++) | |
168 | if (*pos != 0) | |
169 | return 0; | |
170 | return 1; | |
171 | } | |
172 | ||
173 | static hpa_t kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, u64 *parent_pte) | |
174 | { | |
175 | struct kvm_mmu_page *page; | |
176 | ||
177 | if (list_empty(&vcpu->free_pages)) | |
178 | return INVALID_PAGE; | |
179 | ||
180 | page = list_entry(vcpu->free_pages.next, struct kvm_mmu_page, link); | |
181 | list_del(&page->link); | |
182 | list_add(&page->link, &vcpu->kvm->active_mmu_pages); | |
183 | ASSERT(is_empty_shadow_page(page->page_hpa)); | |
184 | page->slot_bitmap = 0; | |
185 | page->global = 1; | |
186 | page->parent_pte = parent_pte; | |
187 | return page->page_hpa; | |
188 | } | |
189 | ||
190 | static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa) | |
191 | { | |
192 | int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT)); | |
193 | struct kvm_mmu_page *page_head = page_header(__pa(pte)); | |
194 | ||
195 | __set_bit(slot, &page_head->slot_bitmap); | |
196 | } | |
197 | ||
198 | hpa_t safe_gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa) | |
199 | { | |
200 | hpa_t hpa = gpa_to_hpa(vcpu, gpa); | |
201 | ||
202 | return is_error_hpa(hpa) ? bad_page_address | (gpa & ~PAGE_MASK): hpa; | |
203 | } | |
204 | ||
205 | hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa) | |
206 | { | |
207 | struct kvm_memory_slot *slot; | |
208 | struct page *page; | |
209 | ||
210 | ASSERT((gpa & HPA_ERR_MASK) == 0); | |
211 | slot = gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT); | |
212 | if (!slot) | |
213 | return gpa | HPA_ERR_MASK; | |
214 | page = gfn_to_page(slot, gpa >> PAGE_SHIFT); | |
215 | return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT) | |
216 | | (gpa & (PAGE_SIZE-1)); | |
217 | } | |
218 | ||
219 | hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva) | |
220 | { | |
221 | gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva); | |
222 | ||
223 | if (gpa == UNMAPPED_GVA) | |
224 | return UNMAPPED_GVA; | |
225 | return gpa_to_hpa(vcpu, gpa); | |
226 | } | |
227 | ||
228 | ||
229 | static void release_pt_page_64(struct kvm_vcpu *vcpu, hpa_t page_hpa, | |
230 | int level) | |
231 | { | |
232 | ASSERT(vcpu); | |
233 | ASSERT(VALID_PAGE(page_hpa)); | |
234 | ASSERT(level <= PT64_ROOT_LEVEL && level > 0); | |
235 | ||
236 | if (level == 1) | |
237 | memset(__va(page_hpa), 0, PAGE_SIZE); | |
238 | else { | |
239 | u64 *pos; | |
240 | u64 *end; | |
241 | ||
242 | for (pos = __va(page_hpa), end = pos + PT64_ENT_PER_PAGE; | |
243 | pos != end; pos++) { | |
244 | u64 current_ent = *pos; | |
245 | ||
246 | *pos = 0; | |
247 | if (is_present_pte(current_ent)) | |
248 | release_pt_page_64(vcpu, | |
249 | current_ent & | |
250 | PT64_BASE_ADDR_MASK, | |
251 | level - 1); | |
252 | } | |
253 | } | |
254 | kvm_mmu_free_page(vcpu, page_hpa); | |
255 | } | |
256 | ||
257 | static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) | |
258 | { | |
259 | } | |
260 | ||
261 | static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p) | |
262 | { | |
263 | int level = PT32E_ROOT_LEVEL; | |
264 | hpa_t table_addr = vcpu->mmu.root_hpa; | |
265 | ||
266 | for (; ; level--) { | |
267 | u32 index = PT64_INDEX(v, level); | |
268 | u64 *table; | |
269 | ||
270 | ASSERT(VALID_PAGE(table_addr)); | |
271 | table = __va(table_addr); | |
272 | ||
273 | if (level == 1) { | |
274 | mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT); | |
275 | page_header_update_slot(vcpu->kvm, table, v); | |
276 | table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK | | |
277 | PT_USER_MASK; | |
278 | return 0; | |
279 | } | |
280 | ||
281 | if (table[index] == 0) { | |
282 | hpa_t new_table = kvm_mmu_alloc_page(vcpu, | |
283 | &table[index]); | |
284 | ||
285 | if (!VALID_PAGE(new_table)) { | |
286 | pgprintk("nonpaging_map: ENOMEM\n"); | |
287 | return -ENOMEM; | |
288 | } | |
289 | ||
290 | if (level == PT32E_ROOT_LEVEL) | |
291 | table[index] = new_table | PT_PRESENT_MASK; | |
292 | else | |
293 | table[index] = new_table | PT_PRESENT_MASK | | |
294 | PT_WRITABLE_MASK | PT_USER_MASK; | |
295 | } | |
296 | table_addr = table[index] & PT64_BASE_ADDR_MASK; | |
297 | } | |
298 | } | |
299 | ||
300 | static void nonpaging_flush(struct kvm_vcpu *vcpu) | |
301 | { | |
302 | hpa_t root = vcpu->mmu.root_hpa; | |
303 | ||
304 | ++kvm_stat.tlb_flush; | |
305 | pgprintk("nonpaging_flush\n"); | |
306 | ASSERT(VALID_PAGE(root)); | |
307 | release_pt_page_64(vcpu, root, vcpu->mmu.shadow_root_level); | |
308 | root = kvm_mmu_alloc_page(vcpu, NULL); | |
309 | ASSERT(VALID_PAGE(root)); | |
310 | vcpu->mmu.root_hpa = root; | |
311 | if (is_paging(vcpu)) | |
312 | root |= (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)); | |
313 | kvm_arch_ops->set_cr3(vcpu, root); | |
314 | kvm_arch_ops->tlb_flush(vcpu); | |
315 | } | |
316 | ||
317 | static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr) | |
318 | { | |
319 | return vaddr; | |
320 | } | |
321 | ||
322 | static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, | |
323 | u32 error_code) | |
324 | { | |
325 | int ret; | |
326 | gpa_t addr = gva; | |
327 | ||
328 | ASSERT(vcpu); | |
329 | ASSERT(VALID_PAGE(vcpu->mmu.root_hpa)); | |
330 | ||
331 | for (;;) { | |
332 | hpa_t paddr; | |
333 | ||
334 | paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK); | |
335 | ||
336 | if (is_error_hpa(paddr)) | |
337 | return 1; | |
338 | ||
339 | ret = nonpaging_map(vcpu, addr & PAGE_MASK, paddr); | |
340 | if (ret) { | |
341 | nonpaging_flush(vcpu); | |
342 | continue; | |
343 | } | |
344 | break; | |
345 | } | |
346 | return ret; | |
347 | } | |
348 | ||
349 | static void nonpaging_inval_page(struct kvm_vcpu *vcpu, gva_t addr) | |
350 | { | |
351 | } | |
352 | ||
353 | static void nonpaging_free(struct kvm_vcpu *vcpu) | |
354 | { | |
355 | hpa_t root; | |
356 | ||
357 | ASSERT(vcpu); | |
358 | root = vcpu->mmu.root_hpa; | |
359 | if (VALID_PAGE(root)) | |
360 | release_pt_page_64(vcpu, root, vcpu->mmu.shadow_root_level); | |
361 | vcpu->mmu.root_hpa = INVALID_PAGE; | |
362 | } | |
363 | ||
364 | static int nonpaging_init_context(struct kvm_vcpu *vcpu) | |
365 | { | |
366 | struct kvm_mmu *context = &vcpu->mmu; | |
367 | ||
368 | context->new_cr3 = nonpaging_new_cr3; | |
369 | context->page_fault = nonpaging_page_fault; | |
370 | context->inval_page = nonpaging_inval_page; | |
371 | context->gva_to_gpa = nonpaging_gva_to_gpa; | |
372 | context->free = nonpaging_free; | |
373 | context->root_level = PT32E_ROOT_LEVEL; | |
374 | context->shadow_root_level = PT32E_ROOT_LEVEL; | |
375 | context->root_hpa = kvm_mmu_alloc_page(vcpu, NULL); | |
376 | ASSERT(VALID_PAGE(context->root_hpa)); | |
377 | kvm_arch_ops->set_cr3(vcpu, context->root_hpa); | |
378 | return 0; | |
379 | } | |
380 | ||
381 | ||
382 | static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu) | |
383 | { | |
384 | struct kvm_mmu_page *page, *npage; | |
385 | ||
386 | list_for_each_entry_safe(page, npage, &vcpu->kvm->active_mmu_pages, | |
387 | link) { | |
388 | if (page->global) | |
389 | continue; | |
390 | ||
391 | if (!page->parent_pte) | |
392 | continue; | |
393 | ||
394 | *page->parent_pte = 0; | |
395 | release_pt_page_64(vcpu, page->page_hpa, 1); | |
396 | } | |
397 | ++kvm_stat.tlb_flush; | |
398 | kvm_arch_ops->tlb_flush(vcpu); | |
399 | } | |
400 | ||
401 | static void paging_new_cr3(struct kvm_vcpu *vcpu) | |
402 | { | |
403 | kvm_mmu_flush_tlb(vcpu); | |
404 | } | |
405 | ||
406 | static void mark_pagetable_nonglobal(void *shadow_pte) | |
407 | { | |
408 | page_header(__pa(shadow_pte))->global = 0; | |
409 | } | |
410 | ||
411 | static inline void set_pte_common(struct kvm_vcpu *vcpu, | |
412 | u64 *shadow_pte, | |
413 | gpa_t gaddr, | |
414 | int dirty, | |
415 | u64 access_bits) | |
416 | { | |
417 | hpa_t paddr; | |
418 | ||
419 | *shadow_pte |= access_bits << PT_SHADOW_BITS_OFFSET; | |
420 | if (!dirty) | |
421 | access_bits &= ~PT_WRITABLE_MASK; | |
422 | ||
423 | if (access_bits & PT_WRITABLE_MASK) | |
424 | mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT); | |
425 | ||
426 | *shadow_pte |= access_bits; | |
427 | ||
428 | paddr = gpa_to_hpa(vcpu, gaddr & PT64_BASE_ADDR_MASK); | |
429 | ||
430 | if (!(*shadow_pte & PT_GLOBAL_MASK)) | |
431 | mark_pagetable_nonglobal(shadow_pte); | |
432 | ||
433 | if (is_error_hpa(paddr)) { | |
434 | *shadow_pte |= gaddr; | |
435 | *shadow_pte |= PT_SHADOW_IO_MARK; | |
436 | *shadow_pte &= ~PT_PRESENT_MASK; | |
437 | } else { | |
438 | *shadow_pte |= paddr; | |
439 | page_header_update_slot(vcpu->kvm, shadow_pte, gaddr); | |
440 | } | |
441 | } | |
442 | ||
443 | static void inject_page_fault(struct kvm_vcpu *vcpu, | |
444 | u64 addr, | |
445 | u32 err_code) | |
446 | { | |
447 | kvm_arch_ops->inject_page_fault(vcpu, addr, err_code); | |
448 | } | |
449 | ||
450 | static inline int fix_read_pf(u64 *shadow_ent) | |
451 | { | |
452 | if ((*shadow_ent & PT_SHADOW_USER_MASK) && | |
453 | !(*shadow_ent & PT_USER_MASK)) { | |
454 | /* | |
455 | * If supervisor write protect is disabled, we shadow kernel | |
456 | * pages as user pages so we can trap the write access. | |
457 | */ | |
458 | *shadow_ent |= PT_USER_MASK; | |
459 | *shadow_ent &= ~PT_WRITABLE_MASK; | |
460 | ||
461 | return 1; | |
462 | ||
463 | } | |
464 | return 0; | |
465 | } | |
466 | ||
467 | static int may_access(u64 pte, int write, int user) | |
468 | { | |
469 | ||
470 | if (user && !(pte & PT_USER_MASK)) | |
471 | return 0; | |
472 | if (write && !(pte & PT_WRITABLE_MASK)) | |
473 | return 0; | |
474 | return 1; | |
475 | } | |
476 | ||
477 | /* | |
478 | * Remove a shadow pte. | |
479 | */ | |
480 | static void paging_inval_page(struct kvm_vcpu *vcpu, gva_t addr) | |
481 | { | |
482 | hpa_t page_addr = vcpu->mmu.root_hpa; | |
483 | int level = vcpu->mmu.shadow_root_level; | |
484 | ||
485 | ++kvm_stat.invlpg; | |
486 | ||
487 | for (; ; level--) { | |
488 | u32 index = PT64_INDEX(addr, level); | |
489 | u64 *table = __va(page_addr); | |
490 | ||
491 | if (level == PT_PAGE_TABLE_LEVEL ) { | |
492 | table[index] = 0; | |
493 | return; | |
494 | } | |
495 | ||
496 | if (!is_present_pte(table[index])) | |
497 | return; | |
498 | ||
499 | page_addr = table[index] & PT64_BASE_ADDR_MASK; | |
500 | ||
501 | if (level == PT_DIRECTORY_LEVEL && | |
502 | (table[index] & PT_SHADOW_PS_MARK)) { | |
503 | table[index] = 0; | |
504 | release_pt_page_64(vcpu, page_addr, PT_PAGE_TABLE_LEVEL); | |
505 | ||
506 | kvm_arch_ops->tlb_flush(vcpu); | |
507 | return; | |
508 | } | |
509 | } | |
510 | } | |
511 | ||
512 | static void paging_free(struct kvm_vcpu *vcpu) | |
513 | { | |
514 | nonpaging_free(vcpu); | |
515 | } | |
516 | ||
517 | #define PTTYPE 64 | |
518 | #include "paging_tmpl.h" | |
519 | #undef PTTYPE | |
520 | ||
521 | #define PTTYPE 32 | |
522 | #include "paging_tmpl.h" | |
523 | #undef PTTYPE | |
524 | ||
525 | static int paging64_init_context(struct kvm_vcpu *vcpu) | |
526 | { | |
527 | struct kvm_mmu *context = &vcpu->mmu; | |
528 | ||
529 | ASSERT(is_pae(vcpu)); | |
530 | context->new_cr3 = paging_new_cr3; | |
531 | context->page_fault = paging64_page_fault; | |
532 | context->inval_page = paging_inval_page; | |
533 | context->gva_to_gpa = paging64_gva_to_gpa; | |
534 | context->free = paging_free; | |
535 | context->root_level = PT64_ROOT_LEVEL; | |
536 | context->shadow_root_level = PT64_ROOT_LEVEL; | |
537 | context->root_hpa = kvm_mmu_alloc_page(vcpu, NULL); | |
538 | ASSERT(VALID_PAGE(context->root_hpa)); | |
539 | kvm_arch_ops->set_cr3(vcpu, context->root_hpa | | |
540 | (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK))); | |
541 | return 0; | |
542 | } | |
543 | ||
544 | static int paging32_init_context(struct kvm_vcpu *vcpu) | |
545 | { | |
546 | struct kvm_mmu *context = &vcpu->mmu; | |
547 | ||
548 | context->new_cr3 = paging_new_cr3; | |
549 | context->page_fault = paging32_page_fault; | |
550 | context->inval_page = paging_inval_page; | |
551 | context->gva_to_gpa = paging32_gva_to_gpa; | |
552 | context->free = paging_free; | |
553 | context->root_level = PT32_ROOT_LEVEL; | |
554 | context->shadow_root_level = PT32E_ROOT_LEVEL; | |
555 | context->root_hpa = kvm_mmu_alloc_page(vcpu, NULL); | |
556 | ASSERT(VALID_PAGE(context->root_hpa)); | |
557 | kvm_arch_ops->set_cr3(vcpu, context->root_hpa | | |
558 | (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK))); | |
559 | return 0; | |
560 | } | |
561 | ||
562 | static int paging32E_init_context(struct kvm_vcpu *vcpu) | |
563 | { | |
564 | int ret; | |
565 | ||
566 | if ((ret = paging64_init_context(vcpu))) | |
567 | return ret; | |
568 | ||
569 | vcpu->mmu.root_level = PT32E_ROOT_LEVEL; | |
570 | vcpu->mmu.shadow_root_level = PT32E_ROOT_LEVEL; | |
571 | return 0; | |
572 | } | |
573 | ||
574 | static int init_kvm_mmu(struct kvm_vcpu *vcpu) | |
575 | { | |
576 | ASSERT(vcpu); | |
577 | ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa)); | |
578 | ||
579 | if (!is_paging(vcpu)) | |
580 | return nonpaging_init_context(vcpu); | |
581 | else if (kvm_arch_ops->is_long_mode(vcpu)) | |
582 | return paging64_init_context(vcpu); | |
583 | else if (is_pae(vcpu)) | |
584 | return paging32E_init_context(vcpu); | |
585 | else | |
586 | return paging32_init_context(vcpu); | |
587 | } | |
588 | ||
589 | static void destroy_kvm_mmu(struct kvm_vcpu *vcpu) | |
590 | { | |
591 | ASSERT(vcpu); | |
592 | if (VALID_PAGE(vcpu->mmu.root_hpa)) { | |
593 | vcpu->mmu.free(vcpu); | |
594 | vcpu->mmu.root_hpa = INVALID_PAGE; | |
595 | } | |
596 | } | |
597 | ||
598 | int kvm_mmu_reset_context(struct kvm_vcpu *vcpu) | |
599 | { | |
600 | destroy_kvm_mmu(vcpu); | |
601 | return init_kvm_mmu(vcpu); | |
602 | } | |
603 | ||
604 | static void free_mmu_pages(struct kvm_vcpu *vcpu) | |
605 | { | |
606 | while (!list_empty(&vcpu->free_pages)) { | |
607 | struct kvm_mmu_page *page; | |
608 | ||
609 | page = list_entry(vcpu->free_pages.next, | |
610 | struct kvm_mmu_page, link); | |
611 | list_del(&page->link); | |
612 | __free_page(pfn_to_page(page->page_hpa >> PAGE_SHIFT)); | |
613 | page->page_hpa = INVALID_PAGE; | |
614 | } | |
615 | } | |
616 | ||
617 | static int alloc_mmu_pages(struct kvm_vcpu *vcpu) | |
618 | { | |
619 | int i; | |
620 | ||
621 | ASSERT(vcpu); | |
622 | ||
623 | for (i = 0; i < KVM_NUM_MMU_PAGES; i++) { | |
624 | struct page *page; | |
625 | struct kvm_mmu_page *page_header = &vcpu->page_header_buf[i]; | |
626 | ||
627 | INIT_LIST_HEAD(&page_header->link); | |
628 | if ((page = alloc_page(GFP_KVM_MMU)) == NULL) | |
629 | goto error_1; | |
630 | page->private = (unsigned long)page_header; | |
631 | page_header->page_hpa = (hpa_t)page_to_pfn(page) << PAGE_SHIFT; | |
632 | memset(__va(page_header->page_hpa), 0, PAGE_SIZE); | |
633 | list_add(&page_header->link, &vcpu->free_pages); | |
634 | } | |
635 | return 0; | |
636 | ||
637 | error_1: | |
638 | free_mmu_pages(vcpu); | |
639 | return -ENOMEM; | |
640 | } | |
641 | ||
642 | int kvm_mmu_init(struct kvm_vcpu *vcpu) | |
643 | { | |
644 | int r; | |
645 | ||
646 | ASSERT(vcpu); | |
647 | ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa)); | |
648 | ASSERT(list_empty(&vcpu->free_pages)); | |
649 | ||
650 | if ((r = alloc_mmu_pages(vcpu))) | |
651 | return r; | |
652 | ||
653 | if ((r = init_kvm_mmu(vcpu))) { | |
654 | free_mmu_pages(vcpu); | |
655 | return r; | |
656 | } | |
657 | return 0; | |
658 | } | |
659 | ||
660 | void kvm_mmu_destroy(struct kvm_vcpu *vcpu) | |
661 | { | |
662 | ASSERT(vcpu); | |
663 | ||
664 | destroy_kvm_mmu(vcpu); | |
665 | free_mmu_pages(vcpu); | |
666 | } | |
667 | ||
668 | void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) | |
669 | { | |
670 | struct kvm_mmu_page *page; | |
671 | ||
672 | list_for_each_entry(page, &kvm->active_mmu_pages, link) { | |
673 | int i; | |
674 | u64 *pt; | |
675 | ||
676 | if (!test_bit(slot, &page->slot_bitmap)) | |
677 | continue; | |
678 | ||
679 | pt = __va(page->page_hpa); | |
680 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) | |
681 | /* avoid RMW */ | |
682 | if (pt[i] & PT_WRITABLE_MASK) | |
683 | pt[i] &= ~PT_WRITABLE_MASK; | |
684 | ||
685 | } | |
686 | } |