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KVM: MMU: handle page removal with shadow mapping
[deliverable/linux.git] / arch / x86 / kvm / mmu.c
1 /*
2 * Kernel-based Virtual Machine driver for Linux
3 *
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
6 *
7 * MMU support
8 *
9 * Copyright (C) 2006 Qumranet, Inc.
10 *
11 * Authors:
12 * Yaniv Kamay <yaniv@qumranet.com>
13 * Avi Kivity <avi@qumranet.com>
14 *
15 * This work is licensed under the terms of the GNU GPL, version 2. See
16 * the COPYING file in the top-level directory.
17 *
18 */
19
20 #include "vmx.h"
21 #include "mmu.h"
22
23 #include <linux/kvm_host.h>
24 #include <linux/types.h>
25 #include <linux/string.h>
26 #include <linux/mm.h>
27 #include <linux/highmem.h>
28 #include <linux/module.h>
29 #include <linux/swap.h>
30
31 #include <asm/page.h>
32 #include <asm/cmpxchg.h>
33 #include <asm/io.h>
34
35 #undef MMU_DEBUG
36
37 #undef AUDIT
38
39 #ifdef AUDIT
40 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
41 #else
42 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
43 #endif
44
45 #ifdef MMU_DEBUG
46
47 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
48 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
49
50 #else
51
52 #define pgprintk(x...) do { } while (0)
53 #define rmap_printk(x...) do { } while (0)
54
55 #endif
56
57 #if defined(MMU_DEBUG) || defined(AUDIT)
58 static int dbg = 1;
59 #endif
60
61 #ifndef MMU_DEBUG
62 #define ASSERT(x) do { } while (0)
63 #else
64 #define ASSERT(x) \
65 if (!(x)) { \
66 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
67 __FILE__, __LINE__, #x); \
68 }
69 #endif
70
71 #define PT64_PT_BITS 9
72 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
73 #define PT32_PT_BITS 10
74 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
75
76 #define PT_WRITABLE_SHIFT 1
77
78 #define PT_PRESENT_MASK (1ULL << 0)
79 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
80 #define PT_USER_MASK (1ULL << 2)
81 #define PT_PWT_MASK (1ULL << 3)
82 #define PT_PCD_MASK (1ULL << 4)
83 #define PT_ACCESSED_MASK (1ULL << 5)
84 #define PT_DIRTY_MASK (1ULL << 6)
85 #define PT_PAGE_SIZE_MASK (1ULL << 7)
86 #define PT_PAT_MASK (1ULL << 7)
87 #define PT_GLOBAL_MASK (1ULL << 8)
88 #define PT64_NX_SHIFT 63
89 #define PT64_NX_MASK (1ULL << PT64_NX_SHIFT)
90
91 #define PT_PAT_SHIFT 7
92 #define PT_DIR_PAT_SHIFT 12
93 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
94
95 #define PT32_DIR_PSE36_SIZE 4
96 #define PT32_DIR_PSE36_SHIFT 13
97 #define PT32_DIR_PSE36_MASK \
98 (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
99
100
101 #define PT_FIRST_AVAIL_BITS_SHIFT 9
102 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
103
104 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
105
106 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
107
108 #define PT64_LEVEL_BITS 9
109
110 #define PT64_LEVEL_SHIFT(level) \
111 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
112
113 #define PT64_LEVEL_MASK(level) \
114 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
115
116 #define PT64_INDEX(address, level)\
117 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
118
119
120 #define PT32_LEVEL_BITS 10
121
122 #define PT32_LEVEL_SHIFT(level) \
123 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
124
125 #define PT32_LEVEL_MASK(level) \
126 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
127
128 #define PT32_INDEX(address, level)\
129 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
130
131
132 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
133 #define PT64_DIR_BASE_ADDR_MASK \
134 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
135
136 #define PT32_BASE_ADDR_MASK PAGE_MASK
137 #define PT32_DIR_BASE_ADDR_MASK \
138 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
139
140 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
141 | PT64_NX_MASK)
142
143 #define PFERR_PRESENT_MASK (1U << 0)
144 #define PFERR_WRITE_MASK (1U << 1)
145 #define PFERR_USER_MASK (1U << 2)
146 #define PFERR_FETCH_MASK (1U << 4)
147
148 #define PT64_ROOT_LEVEL 4
149 #define PT32_ROOT_LEVEL 2
150 #define PT32E_ROOT_LEVEL 3
151
152 #define PT_DIRECTORY_LEVEL 2
153 #define PT_PAGE_TABLE_LEVEL 1
154
155 #define RMAP_EXT 4
156
157 #define ACC_EXEC_MASK 1
158 #define ACC_WRITE_MASK PT_WRITABLE_MASK
159 #define ACC_USER_MASK PT_USER_MASK
160 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
161
162 struct kvm_rmap_desc {
163 u64 *shadow_ptes[RMAP_EXT];
164 struct kvm_rmap_desc *more;
165 };
166
167 static struct kmem_cache *pte_chain_cache;
168 static struct kmem_cache *rmap_desc_cache;
169 static struct kmem_cache *mmu_page_header_cache;
170
171 static u64 __read_mostly shadow_trap_nonpresent_pte;
172 static u64 __read_mostly shadow_notrap_nonpresent_pte;
173
174 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
175 {
176 shadow_trap_nonpresent_pte = trap_pte;
177 shadow_notrap_nonpresent_pte = notrap_pte;
178 }
179 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
180
181 static int is_write_protection(struct kvm_vcpu *vcpu)
182 {
183 return vcpu->arch.cr0 & X86_CR0_WP;
184 }
185
186 static int is_cpuid_PSE36(void)
187 {
188 return 1;
189 }
190
191 static int is_nx(struct kvm_vcpu *vcpu)
192 {
193 return vcpu->arch.shadow_efer & EFER_NX;
194 }
195
196 static int is_present_pte(unsigned long pte)
197 {
198 return pte & PT_PRESENT_MASK;
199 }
200
201 static int is_shadow_present_pte(u64 pte)
202 {
203 pte &= ~PT_SHADOW_IO_MARK;
204 return pte != shadow_trap_nonpresent_pte
205 && pte != shadow_notrap_nonpresent_pte;
206 }
207
208 static int is_writeble_pte(unsigned long pte)
209 {
210 return pte & PT_WRITABLE_MASK;
211 }
212
213 static int is_dirty_pte(unsigned long pte)
214 {
215 return pte & PT_DIRTY_MASK;
216 }
217
218 static int is_io_pte(unsigned long pte)
219 {
220 return pte & PT_SHADOW_IO_MARK;
221 }
222
223 static int is_rmap_pte(u64 pte)
224 {
225 return is_shadow_present_pte(pte);
226 }
227
228 static gfn_t pse36_gfn_delta(u32 gpte)
229 {
230 int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
231
232 return (gpte & PT32_DIR_PSE36_MASK) << shift;
233 }
234
235 static void set_shadow_pte(u64 *sptep, u64 spte)
236 {
237 #ifdef CONFIG_X86_64
238 set_64bit((unsigned long *)sptep, spte);
239 #else
240 set_64bit((unsigned long long *)sptep, spte);
241 #endif
242 }
243
244 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
245 struct kmem_cache *base_cache, int min)
246 {
247 void *obj;
248
249 if (cache->nobjs >= min)
250 return 0;
251 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
252 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
253 if (!obj)
254 return -ENOMEM;
255 cache->objects[cache->nobjs++] = obj;
256 }
257 return 0;
258 }
259
260 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
261 {
262 while (mc->nobjs)
263 kfree(mc->objects[--mc->nobjs]);
264 }
265
266 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
267 int min)
268 {
269 struct page *page;
270
271 if (cache->nobjs >= min)
272 return 0;
273 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
274 page = alloc_page(GFP_KERNEL);
275 if (!page)
276 return -ENOMEM;
277 set_page_private(page, 0);
278 cache->objects[cache->nobjs++] = page_address(page);
279 }
280 return 0;
281 }
282
283 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
284 {
285 while (mc->nobjs)
286 free_page((unsigned long)mc->objects[--mc->nobjs]);
287 }
288
289 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
290 {
291 int r;
292
293 r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
294 pte_chain_cache, 4);
295 if (r)
296 goto out;
297 r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
298 rmap_desc_cache, 1);
299 if (r)
300 goto out;
301 r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
302 if (r)
303 goto out;
304 r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
305 mmu_page_header_cache, 4);
306 out:
307 return r;
308 }
309
310 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
311 {
312 mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache);
313 mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache);
314 mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
315 mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
316 }
317
318 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
319 size_t size)
320 {
321 void *p;
322
323 BUG_ON(!mc->nobjs);
324 p = mc->objects[--mc->nobjs];
325 memset(p, 0, size);
326 return p;
327 }
328
329 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
330 {
331 return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
332 sizeof(struct kvm_pte_chain));
333 }
334
335 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
336 {
337 kfree(pc);
338 }
339
340 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
341 {
342 return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
343 sizeof(struct kvm_rmap_desc));
344 }
345
346 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
347 {
348 kfree(rd);
349 }
350
351 /*
352 * Take gfn and return the reverse mapping to it.
353 * Note: gfn must be unaliased before this function get called
354 */
355
356 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn)
357 {
358 struct kvm_memory_slot *slot;
359
360 slot = gfn_to_memslot(kvm, gfn);
361 return &slot->rmap[gfn - slot->base_gfn];
362 }
363
364 /*
365 * Reverse mapping data structures:
366 *
367 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
368 * that points to page_address(page).
369 *
370 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
371 * containing more mappings.
372 */
373 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
374 {
375 struct kvm_mmu_page *sp;
376 struct kvm_rmap_desc *desc;
377 unsigned long *rmapp;
378 int i;
379
380 if (!is_rmap_pte(*spte))
381 return;
382 gfn = unalias_gfn(vcpu->kvm, gfn);
383 sp = page_header(__pa(spte));
384 sp->gfns[spte - sp->spt] = gfn;
385 rmapp = gfn_to_rmap(vcpu->kvm, gfn);
386 if (!*rmapp) {
387 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
388 *rmapp = (unsigned long)spte;
389 } else if (!(*rmapp & 1)) {
390 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
391 desc = mmu_alloc_rmap_desc(vcpu);
392 desc->shadow_ptes[0] = (u64 *)*rmapp;
393 desc->shadow_ptes[1] = spte;
394 *rmapp = (unsigned long)desc | 1;
395 } else {
396 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
397 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
398 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
399 desc = desc->more;
400 if (desc->shadow_ptes[RMAP_EXT-1]) {
401 desc->more = mmu_alloc_rmap_desc(vcpu);
402 desc = desc->more;
403 }
404 for (i = 0; desc->shadow_ptes[i]; ++i)
405 ;
406 desc->shadow_ptes[i] = spte;
407 }
408 }
409
410 static void rmap_desc_remove_entry(unsigned long *rmapp,
411 struct kvm_rmap_desc *desc,
412 int i,
413 struct kvm_rmap_desc *prev_desc)
414 {
415 int j;
416
417 for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
418 ;
419 desc->shadow_ptes[i] = desc->shadow_ptes[j];
420 desc->shadow_ptes[j] = NULL;
421 if (j != 0)
422 return;
423 if (!prev_desc && !desc->more)
424 *rmapp = (unsigned long)desc->shadow_ptes[0];
425 else
426 if (prev_desc)
427 prev_desc->more = desc->more;
428 else
429 *rmapp = (unsigned long)desc->more | 1;
430 mmu_free_rmap_desc(desc);
431 }
432
433 static void rmap_remove(struct kvm *kvm, u64 *spte)
434 {
435 struct kvm_rmap_desc *desc;
436 struct kvm_rmap_desc *prev_desc;
437 struct kvm_mmu_page *sp;
438 struct page *page;
439 unsigned long *rmapp;
440 int i;
441
442 if (!is_rmap_pte(*spte))
443 return;
444 sp = page_header(__pa(spte));
445 page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
446 mark_page_accessed(page);
447 if (is_writeble_pte(*spte))
448 kvm_release_page_dirty(page);
449 else
450 kvm_release_page_clean(page);
451 rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt]);
452 if (!*rmapp) {
453 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
454 BUG();
455 } else if (!(*rmapp & 1)) {
456 rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
457 if ((u64 *)*rmapp != spte) {
458 printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
459 spte, *spte);
460 BUG();
461 }
462 *rmapp = 0;
463 } else {
464 rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
465 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
466 prev_desc = NULL;
467 while (desc) {
468 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
469 if (desc->shadow_ptes[i] == spte) {
470 rmap_desc_remove_entry(rmapp,
471 desc, i,
472 prev_desc);
473 return;
474 }
475 prev_desc = desc;
476 desc = desc->more;
477 }
478 BUG();
479 }
480 }
481
482 static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
483 {
484 struct kvm_rmap_desc *desc;
485 struct kvm_rmap_desc *prev_desc;
486 u64 *prev_spte;
487 int i;
488
489 if (!*rmapp)
490 return NULL;
491 else if (!(*rmapp & 1)) {
492 if (!spte)
493 return (u64 *)*rmapp;
494 return NULL;
495 }
496 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
497 prev_desc = NULL;
498 prev_spte = NULL;
499 while (desc) {
500 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) {
501 if (prev_spte == spte)
502 return desc->shadow_ptes[i];
503 prev_spte = desc->shadow_ptes[i];
504 }
505 desc = desc->more;
506 }
507 return NULL;
508 }
509
510 static void rmap_write_protect(struct kvm *kvm, u64 gfn)
511 {
512 unsigned long *rmapp;
513 u64 *spte;
514 int write_protected = 0;
515
516 gfn = unalias_gfn(kvm, gfn);
517 rmapp = gfn_to_rmap(kvm, gfn);
518
519 spte = rmap_next(kvm, rmapp, NULL);
520 while (spte) {
521 BUG_ON(!spte);
522 BUG_ON(!(*spte & PT_PRESENT_MASK));
523 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
524 if (is_writeble_pte(*spte)) {
525 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
526 write_protected = 1;
527 }
528 spte = rmap_next(kvm, rmapp, spte);
529 }
530 if (write_protected)
531 kvm_flush_remote_tlbs(kvm);
532 }
533
534 #ifdef MMU_DEBUG
535 static int is_empty_shadow_page(u64 *spt)
536 {
537 u64 *pos;
538 u64 *end;
539
540 for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
541 if ((*pos & ~PT_SHADOW_IO_MARK) != shadow_trap_nonpresent_pte) {
542 printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
543 pos, *pos);
544 return 0;
545 }
546 return 1;
547 }
548 #endif
549
550 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
551 {
552 ASSERT(is_empty_shadow_page(sp->spt));
553 list_del(&sp->link);
554 __free_page(virt_to_page(sp->spt));
555 __free_page(virt_to_page(sp->gfns));
556 kfree(sp);
557 ++kvm->arch.n_free_mmu_pages;
558 }
559
560 static unsigned kvm_page_table_hashfn(gfn_t gfn)
561 {
562 return gfn;
563 }
564
565 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
566 u64 *parent_pte)
567 {
568 struct kvm_mmu_page *sp;
569
570 sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
571 sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
572 sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
573 set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
574 list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
575 ASSERT(is_empty_shadow_page(sp->spt));
576 sp->slot_bitmap = 0;
577 sp->multimapped = 0;
578 sp->parent_pte = parent_pte;
579 --vcpu->kvm->arch.n_free_mmu_pages;
580 return sp;
581 }
582
583 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
584 struct kvm_mmu_page *sp, u64 *parent_pte)
585 {
586 struct kvm_pte_chain *pte_chain;
587 struct hlist_node *node;
588 int i;
589
590 if (!parent_pte)
591 return;
592 if (!sp->multimapped) {
593 u64 *old = sp->parent_pte;
594
595 if (!old) {
596 sp->parent_pte = parent_pte;
597 return;
598 }
599 sp->multimapped = 1;
600 pte_chain = mmu_alloc_pte_chain(vcpu);
601 INIT_HLIST_HEAD(&sp->parent_ptes);
602 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
603 pte_chain->parent_ptes[0] = old;
604 }
605 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
606 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
607 continue;
608 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
609 if (!pte_chain->parent_ptes[i]) {
610 pte_chain->parent_ptes[i] = parent_pte;
611 return;
612 }
613 }
614 pte_chain = mmu_alloc_pte_chain(vcpu);
615 BUG_ON(!pte_chain);
616 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
617 pte_chain->parent_ptes[0] = parent_pte;
618 }
619
620 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
621 u64 *parent_pte)
622 {
623 struct kvm_pte_chain *pte_chain;
624 struct hlist_node *node;
625 int i;
626
627 if (!sp->multimapped) {
628 BUG_ON(sp->parent_pte != parent_pte);
629 sp->parent_pte = NULL;
630 return;
631 }
632 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
633 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
634 if (!pte_chain->parent_ptes[i])
635 break;
636 if (pte_chain->parent_ptes[i] != parent_pte)
637 continue;
638 while (i + 1 < NR_PTE_CHAIN_ENTRIES
639 && pte_chain->parent_ptes[i + 1]) {
640 pte_chain->parent_ptes[i]
641 = pte_chain->parent_ptes[i + 1];
642 ++i;
643 }
644 pte_chain->parent_ptes[i] = NULL;
645 if (i == 0) {
646 hlist_del(&pte_chain->link);
647 mmu_free_pte_chain(pte_chain);
648 if (hlist_empty(&sp->parent_ptes)) {
649 sp->multimapped = 0;
650 sp->parent_pte = NULL;
651 }
652 }
653 return;
654 }
655 BUG();
656 }
657
658 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
659 {
660 unsigned index;
661 struct hlist_head *bucket;
662 struct kvm_mmu_page *sp;
663 struct hlist_node *node;
664
665 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
666 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
667 bucket = &kvm->arch.mmu_page_hash[index];
668 hlist_for_each_entry(sp, node, bucket, hash_link)
669 if (sp->gfn == gfn && !sp->role.metaphysical) {
670 pgprintk("%s: found role %x\n",
671 __FUNCTION__, sp->role.word);
672 return sp;
673 }
674 return NULL;
675 }
676
677 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
678 gfn_t gfn,
679 gva_t gaddr,
680 unsigned level,
681 int metaphysical,
682 unsigned access,
683 u64 *parent_pte)
684 {
685 union kvm_mmu_page_role role;
686 unsigned index;
687 unsigned quadrant;
688 struct hlist_head *bucket;
689 struct kvm_mmu_page *sp;
690 struct hlist_node *node;
691
692 role.word = 0;
693 role.glevels = vcpu->arch.mmu.root_level;
694 role.level = level;
695 role.metaphysical = metaphysical;
696 role.access = access;
697 if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
698 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
699 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
700 role.quadrant = quadrant;
701 }
702 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
703 gfn, role.word);
704 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
705 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
706 hlist_for_each_entry(sp, node, bucket, hash_link)
707 if (sp->gfn == gfn && sp->role.word == role.word) {
708 mmu_page_add_parent_pte(vcpu, sp, parent_pte);
709 pgprintk("%s: found\n", __FUNCTION__);
710 return sp;
711 }
712 ++vcpu->kvm->stat.mmu_cache_miss;
713 sp = kvm_mmu_alloc_page(vcpu, parent_pte);
714 if (!sp)
715 return sp;
716 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
717 sp->gfn = gfn;
718 sp->role = role;
719 hlist_add_head(&sp->hash_link, bucket);
720 vcpu->arch.mmu.prefetch_page(vcpu, sp);
721 if (!metaphysical)
722 rmap_write_protect(vcpu->kvm, gfn);
723 return sp;
724 }
725
726 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
727 struct kvm_mmu_page *sp)
728 {
729 unsigned i;
730 u64 *pt;
731 u64 ent;
732
733 pt = sp->spt;
734
735 if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
736 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
737 if (is_shadow_present_pte(pt[i]))
738 rmap_remove(kvm, &pt[i]);
739 pt[i] = shadow_trap_nonpresent_pte;
740 }
741 kvm_flush_remote_tlbs(kvm);
742 return;
743 }
744
745 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
746 ent = pt[i];
747
748 pt[i] = shadow_trap_nonpresent_pte;
749 if (!is_shadow_present_pte(ent))
750 continue;
751 ent &= PT64_BASE_ADDR_MASK;
752 mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
753 }
754 kvm_flush_remote_tlbs(kvm);
755 }
756
757 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
758 {
759 mmu_page_remove_parent_pte(sp, parent_pte);
760 }
761
762 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
763 {
764 int i;
765
766 for (i = 0; i < KVM_MAX_VCPUS; ++i)
767 if (kvm->vcpus[i])
768 kvm->vcpus[i]->arch.last_pte_updated = NULL;
769 }
770
771 static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
772 {
773 u64 *parent_pte;
774
775 ++kvm->stat.mmu_shadow_zapped;
776 while (sp->multimapped || sp->parent_pte) {
777 if (!sp->multimapped)
778 parent_pte = sp->parent_pte;
779 else {
780 struct kvm_pte_chain *chain;
781
782 chain = container_of(sp->parent_ptes.first,
783 struct kvm_pte_chain, link);
784 parent_pte = chain->parent_ptes[0];
785 }
786 BUG_ON(!parent_pte);
787 kvm_mmu_put_page(sp, parent_pte);
788 set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
789 }
790 kvm_mmu_page_unlink_children(kvm, sp);
791 if (!sp->root_count) {
792 hlist_del(&sp->hash_link);
793 kvm_mmu_free_page(kvm, sp);
794 } else
795 list_move(&sp->link, &kvm->arch.active_mmu_pages);
796 kvm_mmu_reset_last_pte_updated(kvm);
797 }
798
799 /*
800 * Changing the number of mmu pages allocated to the vm
801 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
802 */
803 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
804 {
805 /*
806 * If we set the number of mmu pages to be smaller be than the
807 * number of actived pages , we must to free some mmu pages before we
808 * change the value
809 */
810
811 if ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) >
812 kvm_nr_mmu_pages) {
813 int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages
814 - kvm->arch.n_free_mmu_pages;
815
816 while (n_used_mmu_pages > kvm_nr_mmu_pages) {
817 struct kvm_mmu_page *page;
818
819 page = container_of(kvm->arch.active_mmu_pages.prev,
820 struct kvm_mmu_page, link);
821 kvm_mmu_zap_page(kvm, page);
822 n_used_mmu_pages--;
823 }
824 kvm->arch.n_free_mmu_pages = 0;
825 }
826 else
827 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
828 - kvm->arch.n_alloc_mmu_pages;
829
830 kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
831 }
832
833 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
834 {
835 unsigned index;
836 struct hlist_head *bucket;
837 struct kvm_mmu_page *sp;
838 struct hlist_node *node, *n;
839 int r;
840
841 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
842 r = 0;
843 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
844 bucket = &kvm->arch.mmu_page_hash[index];
845 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
846 if (sp->gfn == gfn && !sp->role.metaphysical) {
847 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
848 sp->role.word);
849 kvm_mmu_zap_page(kvm, sp);
850 r = 1;
851 }
852 return r;
853 }
854
855 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
856 {
857 struct kvm_mmu_page *sp;
858
859 while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
860 pgprintk("%s: zap %lx %x\n", __FUNCTION__, gfn, sp->role.word);
861 kvm_mmu_zap_page(kvm, sp);
862 }
863 }
864
865 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
866 {
867 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
868 struct kvm_mmu_page *sp = page_header(__pa(pte));
869
870 __set_bit(slot, &sp->slot_bitmap);
871 }
872
873 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
874 {
875 struct page *page;
876
877 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
878
879 if (gpa == UNMAPPED_GVA)
880 return NULL;
881
882 down_read(&current->mm->mmap_sem);
883 page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
884 up_read(&current->mm->mmap_sem);
885
886 return page;
887 }
888
889 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
890 unsigned pt_access, unsigned pte_access,
891 int user_fault, int write_fault, int dirty,
892 int *ptwrite, gfn_t gfn, struct page *page)
893 {
894 u64 spte;
895 int was_rmapped = 0;
896 int was_writeble = is_writeble_pte(*shadow_pte);
897 hfn_t host_pfn = (*shadow_pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
898
899 pgprintk("%s: spte %llx access %x write_fault %d"
900 " user_fault %d gfn %lx\n",
901 __FUNCTION__, *shadow_pte, pt_access,
902 write_fault, user_fault, gfn);
903
904 if (is_rmap_pte(*shadow_pte)) {
905 if (host_pfn != page_to_pfn(page)) {
906 pgprintk("hfn old %lx new %lx\n",
907 host_pfn, page_to_pfn(page));
908 rmap_remove(vcpu->kvm, shadow_pte);
909 }
910 else
911 was_rmapped = 1;
912 }
913
914 /*
915 * We don't set the accessed bit, since we sometimes want to see
916 * whether the guest actually used the pte (in order to detect
917 * demand paging).
918 */
919 spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
920 if (!dirty)
921 pte_access &= ~ACC_WRITE_MASK;
922 if (!(pte_access & ACC_EXEC_MASK))
923 spte |= PT64_NX_MASK;
924
925 spte |= PT_PRESENT_MASK;
926 if (pte_access & ACC_USER_MASK)
927 spte |= PT_USER_MASK;
928
929 if (is_error_page(page)) {
930 set_shadow_pte(shadow_pte,
931 shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
932 kvm_release_page_clean(page);
933 return;
934 }
935
936 spte |= page_to_phys(page);
937
938 if ((pte_access & ACC_WRITE_MASK)
939 || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
940 struct kvm_mmu_page *shadow;
941
942 spte |= PT_WRITABLE_MASK;
943 if (user_fault) {
944 mmu_unshadow(vcpu->kvm, gfn);
945 goto unshadowed;
946 }
947
948 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
949 if (shadow) {
950 pgprintk("%s: found shadow page for %lx, marking ro\n",
951 __FUNCTION__, gfn);
952 pte_access &= ~ACC_WRITE_MASK;
953 if (is_writeble_pte(spte)) {
954 spte &= ~PT_WRITABLE_MASK;
955 kvm_x86_ops->tlb_flush(vcpu);
956 }
957 if (write_fault)
958 *ptwrite = 1;
959 }
960 }
961
962 unshadowed:
963
964 if (pte_access & ACC_WRITE_MASK)
965 mark_page_dirty(vcpu->kvm, gfn);
966
967 pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
968 set_shadow_pte(shadow_pte, spte);
969 page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
970 if (!was_rmapped) {
971 rmap_add(vcpu, shadow_pte, gfn);
972 if (!is_rmap_pte(*shadow_pte))
973 kvm_release_page_clean(page);
974 } else {
975 if (was_writeble)
976 kvm_release_page_dirty(page);
977 else
978 kvm_release_page_clean(page);
979 }
980 if (!ptwrite || !*ptwrite)
981 vcpu->arch.last_pte_updated = shadow_pte;
982 }
983
984 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
985 {
986 }
987
988 static int __nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write,
989 gfn_t gfn, struct page *page)
990 {
991 int level = PT32E_ROOT_LEVEL;
992 hpa_t table_addr = vcpu->arch.mmu.root_hpa;
993 int pt_write = 0;
994
995 for (; ; level--) {
996 u32 index = PT64_INDEX(v, level);
997 u64 *table;
998
999 ASSERT(VALID_PAGE(table_addr));
1000 table = __va(table_addr);
1001
1002 if (level == 1) {
1003 mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
1004 0, write, 1, &pt_write, gfn, page);
1005 return pt_write || is_io_pte(table[index]);
1006 }
1007
1008 if (table[index] == shadow_trap_nonpresent_pte) {
1009 struct kvm_mmu_page *new_table;
1010 gfn_t pseudo_gfn;
1011
1012 pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
1013 >> PAGE_SHIFT;
1014 new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
1015 v, level - 1,
1016 1, ACC_ALL, &table[index]);
1017 if (!new_table) {
1018 pgprintk("nonpaging_map: ENOMEM\n");
1019 kvm_release_page_clean(page);
1020 return -ENOMEM;
1021 }
1022
1023 table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
1024 | PT_WRITABLE_MASK | PT_USER_MASK;
1025 }
1026 table_addr = table[index] & PT64_BASE_ADDR_MASK;
1027 }
1028 }
1029
1030 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1031 {
1032 int r;
1033
1034 struct page *page;
1035
1036 down_read(&vcpu->kvm->slots_lock);
1037
1038 down_read(&current->mm->mmap_sem);
1039 page = gfn_to_page(vcpu->kvm, gfn);
1040 up_read(&current->mm->mmap_sem);
1041
1042 spin_lock(&vcpu->kvm->mmu_lock);
1043 kvm_mmu_free_some_pages(vcpu);
1044 r = __nonpaging_map(vcpu, v, write, gfn, page);
1045 spin_unlock(&vcpu->kvm->mmu_lock);
1046
1047 up_read(&vcpu->kvm->slots_lock);
1048
1049 return r;
1050 }
1051
1052
1053 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
1054 struct kvm_mmu_page *sp)
1055 {
1056 int i;
1057
1058 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1059 sp->spt[i] = shadow_trap_nonpresent_pte;
1060 }
1061
1062 static void mmu_free_roots(struct kvm_vcpu *vcpu)
1063 {
1064 int i;
1065 struct kvm_mmu_page *sp;
1066
1067 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1068 return;
1069 spin_lock(&vcpu->kvm->mmu_lock);
1070 #ifdef CONFIG_X86_64
1071 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1072 hpa_t root = vcpu->arch.mmu.root_hpa;
1073
1074 sp = page_header(root);
1075 --sp->root_count;
1076 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1077 spin_unlock(&vcpu->kvm->mmu_lock);
1078 return;
1079 }
1080 #endif
1081 for (i = 0; i < 4; ++i) {
1082 hpa_t root = vcpu->arch.mmu.pae_root[i];
1083
1084 if (root) {
1085 root &= PT64_BASE_ADDR_MASK;
1086 sp = page_header(root);
1087 --sp->root_count;
1088 }
1089 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1090 }
1091 spin_unlock(&vcpu->kvm->mmu_lock);
1092 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1093 }
1094
1095 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
1096 {
1097 int i;
1098 gfn_t root_gfn;
1099 struct kvm_mmu_page *sp;
1100
1101 root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
1102
1103 #ifdef CONFIG_X86_64
1104 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1105 hpa_t root = vcpu->arch.mmu.root_hpa;
1106
1107 ASSERT(!VALID_PAGE(root));
1108 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
1109 PT64_ROOT_LEVEL, 0, ACC_ALL, NULL);
1110 root = __pa(sp->spt);
1111 ++sp->root_count;
1112 vcpu->arch.mmu.root_hpa = root;
1113 return;
1114 }
1115 #endif
1116 for (i = 0; i < 4; ++i) {
1117 hpa_t root = vcpu->arch.mmu.pae_root[i];
1118
1119 ASSERT(!VALID_PAGE(root));
1120 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
1121 if (!is_present_pte(vcpu->arch.pdptrs[i])) {
1122 vcpu->arch.mmu.pae_root[i] = 0;
1123 continue;
1124 }
1125 root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
1126 } else if (vcpu->arch.mmu.root_level == 0)
1127 root_gfn = 0;
1128 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
1129 PT32_ROOT_LEVEL, !is_paging(vcpu),
1130 ACC_ALL, NULL);
1131 root = __pa(sp->spt);
1132 ++sp->root_count;
1133 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
1134 }
1135 vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
1136 }
1137
1138 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
1139 {
1140 return vaddr;
1141 }
1142
1143 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
1144 u32 error_code)
1145 {
1146 gfn_t gfn;
1147 int r;
1148
1149 pgprintk("%s: gva %lx error %x\n", __FUNCTION__, gva, error_code);
1150 r = mmu_topup_memory_caches(vcpu);
1151 if (r)
1152 return r;
1153
1154 ASSERT(vcpu);
1155 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1156
1157 gfn = gva >> PAGE_SHIFT;
1158
1159 return nonpaging_map(vcpu, gva & PAGE_MASK,
1160 error_code & PFERR_WRITE_MASK, gfn);
1161 }
1162
1163 static void nonpaging_free(struct kvm_vcpu *vcpu)
1164 {
1165 mmu_free_roots(vcpu);
1166 }
1167
1168 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
1169 {
1170 struct kvm_mmu *context = &vcpu->arch.mmu;
1171
1172 context->new_cr3 = nonpaging_new_cr3;
1173 context->page_fault = nonpaging_page_fault;
1174 context->gva_to_gpa = nonpaging_gva_to_gpa;
1175 context->free = nonpaging_free;
1176 context->prefetch_page = nonpaging_prefetch_page;
1177 context->root_level = 0;
1178 context->shadow_root_level = PT32E_ROOT_LEVEL;
1179 context->root_hpa = INVALID_PAGE;
1180 return 0;
1181 }
1182
1183 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
1184 {
1185 ++vcpu->stat.tlb_flush;
1186 kvm_x86_ops->tlb_flush(vcpu);
1187 }
1188
1189 static void paging_new_cr3(struct kvm_vcpu *vcpu)
1190 {
1191 pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->arch.cr3);
1192 mmu_free_roots(vcpu);
1193 }
1194
1195 static void inject_page_fault(struct kvm_vcpu *vcpu,
1196 u64 addr,
1197 u32 err_code)
1198 {
1199 kvm_inject_page_fault(vcpu, addr, err_code);
1200 }
1201
1202 static void paging_free(struct kvm_vcpu *vcpu)
1203 {
1204 nonpaging_free(vcpu);
1205 }
1206
1207 #define PTTYPE 64
1208 #include "paging_tmpl.h"
1209 #undef PTTYPE
1210
1211 #define PTTYPE 32
1212 #include "paging_tmpl.h"
1213 #undef PTTYPE
1214
1215 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1216 {
1217 struct kvm_mmu *context = &vcpu->arch.mmu;
1218
1219 ASSERT(is_pae(vcpu));
1220 context->new_cr3 = paging_new_cr3;
1221 context->page_fault = paging64_page_fault;
1222 context->gva_to_gpa = paging64_gva_to_gpa;
1223 context->prefetch_page = paging64_prefetch_page;
1224 context->free = paging_free;
1225 context->root_level = level;
1226 context->shadow_root_level = level;
1227 context->root_hpa = INVALID_PAGE;
1228 return 0;
1229 }
1230
1231 static int paging64_init_context(struct kvm_vcpu *vcpu)
1232 {
1233 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1234 }
1235
1236 static int paging32_init_context(struct kvm_vcpu *vcpu)
1237 {
1238 struct kvm_mmu *context = &vcpu->arch.mmu;
1239
1240 context->new_cr3 = paging_new_cr3;
1241 context->page_fault = paging32_page_fault;
1242 context->gva_to_gpa = paging32_gva_to_gpa;
1243 context->free = paging_free;
1244 context->prefetch_page = paging32_prefetch_page;
1245 context->root_level = PT32_ROOT_LEVEL;
1246 context->shadow_root_level = PT32E_ROOT_LEVEL;
1247 context->root_hpa = INVALID_PAGE;
1248 return 0;
1249 }
1250
1251 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1252 {
1253 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1254 }
1255
1256 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1257 {
1258 ASSERT(vcpu);
1259 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1260
1261 if (!is_paging(vcpu))
1262 return nonpaging_init_context(vcpu);
1263 else if (is_long_mode(vcpu))
1264 return paging64_init_context(vcpu);
1265 else if (is_pae(vcpu))
1266 return paging32E_init_context(vcpu);
1267 else
1268 return paging32_init_context(vcpu);
1269 }
1270
1271 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1272 {
1273 ASSERT(vcpu);
1274 if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
1275 vcpu->arch.mmu.free(vcpu);
1276 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1277 }
1278 }
1279
1280 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1281 {
1282 destroy_kvm_mmu(vcpu);
1283 return init_kvm_mmu(vcpu);
1284 }
1285 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
1286
1287 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1288 {
1289 int r;
1290
1291 r = mmu_topup_memory_caches(vcpu);
1292 if (r)
1293 goto out;
1294 spin_lock(&vcpu->kvm->mmu_lock);
1295 kvm_mmu_free_some_pages(vcpu);
1296 mmu_alloc_roots(vcpu);
1297 spin_unlock(&vcpu->kvm->mmu_lock);
1298 kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
1299 kvm_mmu_flush_tlb(vcpu);
1300 out:
1301 return r;
1302 }
1303 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1304
1305 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1306 {
1307 mmu_free_roots(vcpu);
1308 }
1309
1310 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1311 struct kvm_mmu_page *sp,
1312 u64 *spte)
1313 {
1314 u64 pte;
1315 struct kvm_mmu_page *child;
1316
1317 pte = *spte;
1318 if (is_shadow_present_pte(pte)) {
1319 if (sp->role.level == PT_PAGE_TABLE_LEVEL)
1320 rmap_remove(vcpu->kvm, spte);
1321 else {
1322 child = page_header(pte & PT64_BASE_ADDR_MASK);
1323 mmu_page_remove_parent_pte(child, spte);
1324 }
1325 }
1326 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
1327 }
1328
1329 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1330 struct kvm_mmu_page *sp,
1331 u64 *spte,
1332 const void *new, int bytes,
1333 int offset_in_pte)
1334 {
1335 if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
1336 ++vcpu->kvm->stat.mmu_pde_zapped;
1337 return;
1338 }
1339
1340 ++vcpu->kvm->stat.mmu_pte_updated;
1341 if (sp->role.glevels == PT32_ROOT_LEVEL)
1342 paging32_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte);
1343 else
1344 paging64_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte);
1345 }
1346
1347 static bool need_remote_flush(u64 old, u64 new)
1348 {
1349 if (!is_shadow_present_pte(old))
1350 return false;
1351 if (!is_shadow_present_pte(new))
1352 return true;
1353 if ((old ^ new) & PT64_BASE_ADDR_MASK)
1354 return true;
1355 old ^= PT64_NX_MASK;
1356 new ^= PT64_NX_MASK;
1357 return (old & ~new & PT64_PERM_MASK) != 0;
1358 }
1359
1360 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
1361 {
1362 if (need_remote_flush(old, new))
1363 kvm_flush_remote_tlbs(vcpu->kvm);
1364 else
1365 kvm_mmu_flush_tlb(vcpu);
1366 }
1367
1368 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
1369 {
1370 u64 *spte = vcpu->arch.last_pte_updated;
1371
1372 return !!(spte && (*spte & PT_ACCESSED_MASK));
1373 }
1374
1375 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1376 const u8 *new, int bytes)
1377 {
1378 gfn_t gfn;
1379 int r;
1380 u64 gpte = 0;
1381 struct page *page;
1382
1383 if (bytes != 4 && bytes != 8)
1384 return;
1385
1386 /*
1387 * Assume that the pte write on a page table of the same type
1388 * as the current vcpu paging mode. This is nearly always true
1389 * (might be false while changing modes). Note it is verified later
1390 * by update_pte().
1391 */
1392 if (is_pae(vcpu)) {
1393 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
1394 if ((bytes == 4) && (gpa % 4 == 0)) {
1395 r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
1396 if (r)
1397 return;
1398 memcpy((void *)&gpte + (gpa % 8), new, 4);
1399 } else if ((bytes == 8) && (gpa % 8 == 0)) {
1400 memcpy((void *)&gpte, new, 8);
1401 }
1402 } else {
1403 if ((bytes == 4) && (gpa % 4 == 0))
1404 memcpy((void *)&gpte, new, 4);
1405 }
1406 if (!is_present_pte(gpte))
1407 return;
1408 gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
1409
1410 down_read(&current->mm->mmap_sem);
1411 page = gfn_to_page(vcpu->kvm, gfn);
1412 up_read(&current->mm->mmap_sem);
1413
1414 vcpu->arch.update_pte.gfn = gfn;
1415 vcpu->arch.update_pte.page = gfn_to_page(vcpu->kvm, gfn);
1416 }
1417
1418 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1419 const u8 *new, int bytes)
1420 {
1421 gfn_t gfn = gpa >> PAGE_SHIFT;
1422 struct kvm_mmu_page *sp;
1423 struct hlist_node *node, *n;
1424 struct hlist_head *bucket;
1425 unsigned index;
1426 u64 entry;
1427 u64 *spte;
1428 unsigned offset = offset_in_page(gpa);
1429 unsigned pte_size;
1430 unsigned page_offset;
1431 unsigned misaligned;
1432 unsigned quadrant;
1433 int level;
1434 int flooded = 0;
1435 int npte;
1436
1437 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
1438 mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
1439 spin_lock(&vcpu->kvm->mmu_lock);
1440 kvm_mmu_free_some_pages(vcpu);
1441 ++vcpu->kvm->stat.mmu_pte_write;
1442 kvm_mmu_audit(vcpu, "pre pte write");
1443 if (gfn == vcpu->arch.last_pt_write_gfn
1444 && !last_updated_pte_accessed(vcpu)) {
1445 ++vcpu->arch.last_pt_write_count;
1446 if (vcpu->arch.last_pt_write_count >= 3)
1447 flooded = 1;
1448 } else {
1449 vcpu->arch.last_pt_write_gfn = gfn;
1450 vcpu->arch.last_pt_write_count = 1;
1451 vcpu->arch.last_pte_updated = NULL;
1452 }
1453 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
1454 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1455 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
1456 if (sp->gfn != gfn || sp->role.metaphysical)
1457 continue;
1458 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1459 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1460 misaligned |= bytes < 4;
1461 if (misaligned || flooded) {
1462 /*
1463 * Misaligned accesses are too much trouble to fix
1464 * up; also, they usually indicate a page is not used
1465 * as a page table.
1466 *
1467 * If we're seeing too many writes to a page,
1468 * it may no longer be a page table, or we may be
1469 * forking, in which case it is better to unmap the
1470 * page.
1471 */
1472 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1473 gpa, bytes, sp->role.word);
1474 kvm_mmu_zap_page(vcpu->kvm, sp);
1475 ++vcpu->kvm->stat.mmu_flooded;
1476 continue;
1477 }
1478 page_offset = offset;
1479 level = sp->role.level;
1480 npte = 1;
1481 if (sp->role.glevels == PT32_ROOT_LEVEL) {
1482 page_offset <<= 1; /* 32->64 */
1483 /*
1484 * A 32-bit pde maps 4MB while the shadow pdes map
1485 * only 2MB. So we need to double the offset again
1486 * and zap two pdes instead of one.
1487 */
1488 if (level == PT32_ROOT_LEVEL) {
1489 page_offset &= ~7; /* kill rounding error */
1490 page_offset <<= 1;
1491 npte = 2;
1492 }
1493 quadrant = page_offset >> PAGE_SHIFT;
1494 page_offset &= ~PAGE_MASK;
1495 if (quadrant != sp->role.quadrant)
1496 continue;
1497 }
1498 spte = &sp->spt[page_offset / sizeof(*spte)];
1499 while (npte--) {
1500 entry = *spte;
1501 mmu_pte_write_zap_pte(vcpu, sp, spte);
1502 mmu_pte_write_new_pte(vcpu, sp, spte, new, bytes,
1503 page_offset & (pte_size - 1));
1504 mmu_pte_write_flush_tlb(vcpu, entry, *spte);
1505 ++spte;
1506 }
1507 }
1508 kvm_mmu_audit(vcpu, "post pte write");
1509 spin_unlock(&vcpu->kvm->mmu_lock);
1510 if (vcpu->arch.update_pte.page) {
1511 kvm_release_page_clean(vcpu->arch.update_pte.page);
1512 vcpu->arch.update_pte.page = NULL;
1513 }
1514 }
1515
1516 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1517 {
1518 gpa_t gpa;
1519 int r;
1520
1521 down_read(&vcpu->kvm->slots_lock);
1522 gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1523 up_read(&vcpu->kvm->slots_lock);
1524
1525 spin_lock(&vcpu->kvm->mmu_lock);
1526 r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1527 spin_unlock(&vcpu->kvm->mmu_lock);
1528 return r;
1529 }
1530
1531 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1532 {
1533 while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) {
1534 struct kvm_mmu_page *sp;
1535
1536 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
1537 struct kvm_mmu_page, link);
1538 kvm_mmu_zap_page(vcpu->kvm, sp);
1539 ++vcpu->kvm->stat.mmu_recycled;
1540 }
1541 }
1542
1543 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
1544 {
1545 int r;
1546 enum emulation_result er;
1547
1548 r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
1549 if (r < 0)
1550 goto out;
1551
1552 if (!r) {
1553 r = 1;
1554 goto out;
1555 }
1556
1557 r = mmu_topup_memory_caches(vcpu);
1558 if (r)
1559 goto out;
1560
1561 er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
1562
1563 switch (er) {
1564 case EMULATE_DONE:
1565 return 1;
1566 case EMULATE_DO_MMIO:
1567 ++vcpu->stat.mmio_exits;
1568 return 0;
1569 case EMULATE_FAIL:
1570 kvm_report_emulation_failure(vcpu, "pagetable");
1571 return 1;
1572 default:
1573 BUG();
1574 }
1575 out:
1576 return r;
1577 }
1578 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
1579
1580 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1581 {
1582 struct kvm_mmu_page *sp;
1583
1584 while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
1585 sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
1586 struct kvm_mmu_page, link);
1587 kvm_mmu_zap_page(vcpu->kvm, sp);
1588 }
1589 free_page((unsigned long)vcpu->arch.mmu.pae_root);
1590 }
1591
1592 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1593 {
1594 struct page *page;
1595 int i;
1596
1597 ASSERT(vcpu);
1598
1599 if (vcpu->kvm->arch.n_requested_mmu_pages)
1600 vcpu->kvm->arch.n_free_mmu_pages =
1601 vcpu->kvm->arch.n_requested_mmu_pages;
1602 else
1603 vcpu->kvm->arch.n_free_mmu_pages =
1604 vcpu->kvm->arch.n_alloc_mmu_pages;
1605 /*
1606 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1607 * Therefore we need to allocate shadow page tables in the first
1608 * 4GB of memory, which happens to fit the DMA32 zone.
1609 */
1610 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
1611 if (!page)
1612 goto error_1;
1613 vcpu->arch.mmu.pae_root = page_address(page);
1614 for (i = 0; i < 4; ++i)
1615 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1616
1617 return 0;
1618
1619 error_1:
1620 free_mmu_pages(vcpu);
1621 return -ENOMEM;
1622 }
1623
1624 int kvm_mmu_create(struct kvm_vcpu *vcpu)
1625 {
1626 ASSERT(vcpu);
1627 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1628
1629 return alloc_mmu_pages(vcpu);
1630 }
1631
1632 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
1633 {
1634 ASSERT(vcpu);
1635 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1636
1637 return init_kvm_mmu(vcpu);
1638 }
1639
1640 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
1641 {
1642 ASSERT(vcpu);
1643
1644 destroy_kvm_mmu(vcpu);
1645 free_mmu_pages(vcpu);
1646 mmu_free_memory_caches(vcpu);
1647 }
1648
1649 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
1650 {
1651 struct kvm_mmu_page *sp;
1652
1653 list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
1654 int i;
1655 u64 *pt;
1656
1657 if (!test_bit(slot, &sp->slot_bitmap))
1658 continue;
1659
1660 pt = sp->spt;
1661 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1662 /* avoid RMW */
1663 if (pt[i] & PT_WRITABLE_MASK)
1664 pt[i] &= ~PT_WRITABLE_MASK;
1665 }
1666 }
1667
1668 void kvm_mmu_zap_all(struct kvm *kvm)
1669 {
1670 struct kvm_mmu_page *sp, *node;
1671
1672 spin_lock(&kvm->mmu_lock);
1673 list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
1674 kvm_mmu_zap_page(kvm, sp);
1675 spin_unlock(&kvm->mmu_lock);
1676
1677 kvm_flush_remote_tlbs(kvm);
1678 }
1679
1680 void kvm_mmu_module_exit(void)
1681 {
1682 if (pte_chain_cache)
1683 kmem_cache_destroy(pte_chain_cache);
1684 if (rmap_desc_cache)
1685 kmem_cache_destroy(rmap_desc_cache);
1686 if (mmu_page_header_cache)
1687 kmem_cache_destroy(mmu_page_header_cache);
1688 }
1689
1690 int kvm_mmu_module_init(void)
1691 {
1692 pte_chain_cache = kmem_cache_create("kvm_pte_chain",
1693 sizeof(struct kvm_pte_chain),
1694 0, 0, NULL);
1695 if (!pte_chain_cache)
1696 goto nomem;
1697 rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
1698 sizeof(struct kvm_rmap_desc),
1699 0, 0, NULL);
1700 if (!rmap_desc_cache)
1701 goto nomem;
1702
1703 mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
1704 sizeof(struct kvm_mmu_page),
1705 0, 0, NULL);
1706 if (!mmu_page_header_cache)
1707 goto nomem;
1708
1709 return 0;
1710
1711 nomem:
1712 kvm_mmu_module_exit();
1713 return -ENOMEM;
1714 }
1715
1716 /*
1717 * Caculate mmu pages needed for kvm.
1718 */
1719 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
1720 {
1721 int i;
1722 unsigned int nr_mmu_pages;
1723 unsigned int nr_pages = 0;
1724
1725 for (i = 0; i < kvm->nmemslots; i++)
1726 nr_pages += kvm->memslots[i].npages;
1727
1728 nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
1729 nr_mmu_pages = max(nr_mmu_pages,
1730 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
1731
1732 return nr_mmu_pages;
1733 }
1734
1735 #ifdef AUDIT
1736
1737 static const char *audit_msg;
1738
1739 static gva_t canonicalize(gva_t gva)
1740 {
1741 #ifdef CONFIG_X86_64
1742 gva = (long long)(gva << 16) >> 16;
1743 #endif
1744 return gva;
1745 }
1746
1747 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
1748 gva_t va, int level)
1749 {
1750 u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
1751 int i;
1752 gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
1753
1754 for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
1755 u64 ent = pt[i];
1756
1757 if (ent == shadow_trap_nonpresent_pte)
1758 continue;
1759
1760 va = canonicalize(va);
1761 if (level > 1) {
1762 if (ent == shadow_notrap_nonpresent_pte)
1763 printk(KERN_ERR "audit: (%s) nontrapping pte"
1764 " in nonleaf level: levels %d gva %lx"
1765 " level %d pte %llx\n", audit_msg,
1766 vcpu->arch.mmu.root_level, va, level, ent);
1767
1768 audit_mappings_page(vcpu, ent, va, level - 1);
1769 } else {
1770 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
1771 struct page *page = gpa_to_page(vcpu, gpa);
1772 hpa_t hpa = page_to_phys(page);
1773
1774 if (is_shadow_present_pte(ent)
1775 && (ent & PT64_BASE_ADDR_MASK) != hpa)
1776 printk(KERN_ERR "xx audit error: (%s) levels %d"
1777 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
1778 audit_msg, vcpu->arch.mmu.root_level,
1779 va, gpa, hpa, ent,
1780 is_shadow_present_pte(ent));
1781 else if (ent == shadow_notrap_nonpresent_pte
1782 && !is_error_hpa(hpa))
1783 printk(KERN_ERR "audit: (%s) notrap shadow,"
1784 " valid guest gva %lx\n", audit_msg, va);
1785 kvm_release_page_clean(page);
1786
1787 }
1788 }
1789 }
1790
1791 static void audit_mappings(struct kvm_vcpu *vcpu)
1792 {
1793 unsigned i;
1794
1795 if (vcpu->arch.mmu.root_level == 4)
1796 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
1797 else
1798 for (i = 0; i < 4; ++i)
1799 if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
1800 audit_mappings_page(vcpu,
1801 vcpu->arch.mmu.pae_root[i],
1802 i << 30,
1803 2);
1804 }
1805
1806 static int count_rmaps(struct kvm_vcpu *vcpu)
1807 {
1808 int nmaps = 0;
1809 int i, j, k;
1810
1811 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1812 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
1813 struct kvm_rmap_desc *d;
1814
1815 for (j = 0; j < m->npages; ++j) {
1816 unsigned long *rmapp = &m->rmap[j];
1817
1818 if (!*rmapp)
1819 continue;
1820 if (!(*rmapp & 1)) {
1821 ++nmaps;
1822 continue;
1823 }
1824 d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
1825 while (d) {
1826 for (k = 0; k < RMAP_EXT; ++k)
1827 if (d->shadow_ptes[k])
1828 ++nmaps;
1829 else
1830 break;
1831 d = d->more;
1832 }
1833 }
1834 }
1835 return nmaps;
1836 }
1837
1838 static int count_writable_mappings(struct kvm_vcpu *vcpu)
1839 {
1840 int nmaps = 0;
1841 struct kvm_mmu_page *sp;
1842 int i;
1843
1844 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
1845 u64 *pt = sp->spt;
1846
1847 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
1848 continue;
1849
1850 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1851 u64 ent = pt[i];
1852
1853 if (!(ent & PT_PRESENT_MASK))
1854 continue;
1855 if (!(ent & PT_WRITABLE_MASK))
1856 continue;
1857 ++nmaps;
1858 }
1859 }
1860 return nmaps;
1861 }
1862
1863 static void audit_rmap(struct kvm_vcpu *vcpu)
1864 {
1865 int n_rmap = count_rmaps(vcpu);
1866 int n_actual = count_writable_mappings(vcpu);
1867
1868 if (n_rmap != n_actual)
1869 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
1870 __FUNCTION__, audit_msg, n_rmap, n_actual);
1871 }
1872
1873 static void audit_write_protection(struct kvm_vcpu *vcpu)
1874 {
1875 struct kvm_mmu_page *sp;
1876 struct kvm_memory_slot *slot;
1877 unsigned long *rmapp;
1878 gfn_t gfn;
1879
1880 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
1881 if (sp->role.metaphysical)
1882 continue;
1883
1884 slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
1885 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
1886 rmapp = &slot->rmap[gfn - slot->base_gfn];
1887 if (*rmapp)
1888 printk(KERN_ERR "%s: (%s) shadow page has writable"
1889 " mappings: gfn %lx role %x\n",
1890 __FUNCTION__, audit_msg, sp->gfn,
1891 sp->role.word);
1892 }
1893 }
1894
1895 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
1896 {
1897 int olddbg = dbg;
1898
1899 dbg = 0;
1900 audit_msg = msg;
1901 audit_rmap(vcpu);
1902 audit_write_protection(vcpu);
1903 audit_mappings(vcpu);
1904 dbg = olddbg;
1905 }
1906
1907 #endif
Linux kernel - Deliverables
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