2 * Kernel-based Virtual Machine driver for Linux
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
9 * Copyright (C) 2006 Qumranet, Inc.
12 * Yaniv Kamay <yaniv@qumranet.com>
13 * Avi Kivity <avi@qumranet.com>
15 * This work is licensed under the terms of the GNU GPL, version 2. See
16 * the COPYING file in the top-level directory.
19 #include <linux/types.h>
20 #include <linux/string.h>
23 #include <linux/highmem.h>
24 #include <linux/module.h>
29 #define pgprintk(x...) do { } while (0)
30 #define rmap_printk(x...) do { } while (0)
34 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
35 __FILE__, __LINE__, #x); \
38 #define PT64_ENT_PER_PAGE 512
39 #define PT32_ENT_PER_PAGE 1024
41 #define PT_WRITABLE_SHIFT 1
43 #define PT_PRESENT_MASK (1ULL << 0)
44 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
45 #define PT_USER_MASK (1ULL << 2)
46 #define PT_PWT_MASK (1ULL << 3)
47 #define PT_PCD_MASK (1ULL << 4)
48 #define PT_ACCESSED_MASK (1ULL << 5)
49 #define PT_DIRTY_MASK (1ULL << 6)
50 #define PT_PAGE_SIZE_MASK (1ULL << 7)
51 #define PT_PAT_MASK (1ULL << 7)
52 #define PT_GLOBAL_MASK (1ULL << 8)
53 #define PT64_NX_MASK (1ULL << 63)
55 #define PT_PAT_SHIFT 7
56 #define PT_DIR_PAT_SHIFT 12
57 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
59 #define PT32_DIR_PSE36_SIZE 4
60 #define PT32_DIR_PSE36_SHIFT 13
61 #define PT32_DIR_PSE36_MASK (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
64 #define PT32_PTE_COPY_MASK \
65 (PT_PRESENT_MASK | PT_ACCESSED_MASK | PT_DIRTY_MASK | PT_GLOBAL_MASK)
67 #define PT64_PTE_COPY_MASK (PT64_NX_MASK | PT32_PTE_COPY_MASK)
69 #define PT_FIRST_AVAIL_BITS_SHIFT 9
70 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
72 #define PT_SHADOW_PS_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
73 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
75 #define PT_SHADOW_WRITABLE_SHIFT (PT_FIRST_AVAIL_BITS_SHIFT + 1)
76 #define PT_SHADOW_WRITABLE_MASK (1ULL << PT_SHADOW_WRITABLE_SHIFT)
78 #define PT_SHADOW_USER_SHIFT (PT_SHADOW_WRITABLE_SHIFT + 1)
79 #define PT_SHADOW_USER_MASK (1ULL << (PT_SHADOW_USER_SHIFT))
81 #define PT_SHADOW_BITS_OFFSET (PT_SHADOW_WRITABLE_SHIFT - PT_WRITABLE_SHIFT)
83 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
85 #define PT64_LEVEL_BITS 9
87 #define PT64_LEVEL_SHIFT(level) \
88 ( PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS )
90 #define PT64_LEVEL_MASK(level) \
91 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
93 #define PT64_INDEX(address, level)\
94 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
97 #define PT32_LEVEL_BITS 10
99 #define PT32_LEVEL_SHIFT(level) \
100 ( PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS )
102 #define PT32_LEVEL_MASK(level) \
103 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
105 #define PT32_INDEX(address, level)\
106 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
109 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & PAGE_MASK)
110 #define PT64_DIR_BASE_ADDR_MASK \
111 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
113 #define PT32_BASE_ADDR_MASK PAGE_MASK
114 #define PT32_DIR_BASE_ADDR_MASK \
115 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
118 #define PFERR_PRESENT_MASK (1U << 0)
119 #define PFERR_WRITE_MASK (1U << 1)
120 #define PFERR_USER_MASK (1U << 2)
122 #define PT64_ROOT_LEVEL 4
123 #define PT32_ROOT_LEVEL 2
124 #define PT32E_ROOT_LEVEL 3
126 #define PT_DIRECTORY_LEVEL 2
127 #define PT_PAGE_TABLE_LEVEL 1
131 struct kvm_rmap_desc {
132 u64 *shadow_ptes[RMAP_EXT];
133 struct kvm_rmap_desc *more;
136 static int is_write_protection(struct kvm_vcpu *vcpu)
138 return vcpu->cr0 & CR0_WP_MASK;
141 static int is_cpuid_PSE36(void)
146 static int is_present_pte(unsigned long pte)
148 return pte & PT_PRESENT_MASK;
151 static int is_writeble_pte(unsigned long pte)
153 return pte & PT_WRITABLE_MASK;
156 static int is_io_pte(unsigned long pte)
158 return pte & PT_SHADOW_IO_MARK;
161 static int is_rmap_pte(u64 pte)
163 return (pte & (PT_WRITABLE_MASK | PT_PRESENT_MASK))
164 == (PT_WRITABLE_MASK | PT_PRESENT_MASK);
168 * Reverse mapping data structures:
170 * If page->private bit zero is zero, then page->private points to the
171 * shadow page table entry that points to page_address(page).
173 * If page->private bit zero is one, (then page->private & ~1) points
174 * to a struct kvm_rmap_desc containing more mappings.
176 static void rmap_add(struct kvm *kvm, u64 *spte)
179 struct kvm_rmap_desc *desc;
182 if (!is_rmap_pte(*spte))
184 page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
185 if (!page->private) {
186 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
187 page->private = (unsigned long)spte;
188 } else if (!(page->private & 1)) {
189 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
190 desc = kzalloc(sizeof *desc, GFP_NOWAIT);
192 BUG(); /* FIXME: return error */
193 desc->shadow_ptes[0] = (u64 *)page->private;
194 desc->shadow_ptes[1] = spte;
195 page->private = (unsigned long)desc | 1;
197 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
198 desc = (struct kvm_rmap_desc *)(page->private & ~1ul);
199 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
201 if (desc->shadow_ptes[RMAP_EXT-1]) {
202 desc->more = kzalloc(sizeof *desc->more, GFP_NOWAIT);
204 BUG(); /* FIXME: return error */
207 for (i = 0; desc->shadow_ptes[i]; ++i)
209 desc->shadow_ptes[i] = spte;
213 static void rmap_desc_remove_entry(struct page *page,
214 struct kvm_rmap_desc *desc,
216 struct kvm_rmap_desc *prev_desc)
220 for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
222 desc->shadow_ptes[i] = desc->shadow_ptes[j];
223 desc->shadow_ptes[j] = 0;
226 if (!prev_desc && !desc->more)
227 page->private = (unsigned long)desc->shadow_ptes[0];
230 prev_desc->more = desc->more;
232 page->private = (unsigned long)desc->more | 1;
236 static void rmap_remove(struct kvm *kvm, u64 *spte)
239 struct kvm_rmap_desc *desc;
240 struct kvm_rmap_desc *prev_desc;
243 if (!is_rmap_pte(*spte))
245 page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
246 if (!page->private) {
247 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
249 } else if (!(page->private & 1)) {
250 rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
251 if ((u64 *)page->private != spte) {
252 printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
258 rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
259 desc = (struct kvm_rmap_desc *)(page->private & ~1ul);
262 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
263 if (desc->shadow_ptes[i] == spte) {
264 rmap_desc_remove_entry(page, desc, i,
275 static void kvm_mmu_free_page(struct kvm_vcpu *vcpu, hpa_t page_hpa)
277 struct kvm_mmu_page *page_head = page_header(page_hpa);
279 list_del(&page_head->link);
280 page_head->page_hpa = page_hpa;
281 list_add(&page_head->link, &vcpu->free_pages);
284 static int is_empty_shadow_page(hpa_t page_hpa)
288 for (pos = __va(page_hpa), end = pos + PAGE_SIZE / sizeof(u32);
295 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
298 struct kvm_mmu_page *page;
300 if (list_empty(&vcpu->free_pages))
303 page = list_entry(vcpu->free_pages.next, struct kvm_mmu_page, link);
304 list_del(&page->link);
305 list_add(&page->link, &vcpu->kvm->active_mmu_pages);
306 ASSERT(is_empty_shadow_page(page->page_hpa));
307 page->slot_bitmap = 0;
309 page->parent_pte = parent_pte;
313 static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa)
315 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT));
316 struct kvm_mmu_page *page_head = page_header(__pa(pte));
318 __set_bit(slot, &page_head->slot_bitmap);
321 hpa_t safe_gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
323 hpa_t hpa = gpa_to_hpa(vcpu, gpa);
325 return is_error_hpa(hpa) ? bad_page_address | (gpa & ~PAGE_MASK): hpa;
328 hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
330 struct kvm_memory_slot *slot;
333 ASSERT((gpa & HPA_ERR_MASK) == 0);
334 slot = gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT);
336 return gpa | HPA_ERR_MASK;
337 page = gfn_to_page(slot, gpa >> PAGE_SHIFT);
338 return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT)
339 | (gpa & (PAGE_SIZE-1));
342 hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva)
344 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
346 if (gpa == UNMAPPED_GVA)
348 return gpa_to_hpa(vcpu, gpa);
352 static void release_pt_page_64(struct kvm_vcpu *vcpu, hpa_t page_hpa,
359 ASSERT(VALID_PAGE(page_hpa));
360 ASSERT(level <= PT64_ROOT_LEVEL && level > 0);
362 for (pos = __va(page_hpa), end = pos + PT64_ENT_PER_PAGE;
364 u64 current_ent = *pos;
366 if (is_present_pte(current_ent)) {
368 release_pt_page_64(vcpu,
373 rmap_remove(vcpu->kvm, pos);
377 kvm_mmu_free_page(vcpu, page_hpa);
380 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
384 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
386 int level = PT32E_ROOT_LEVEL;
387 hpa_t table_addr = vcpu->mmu.root_hpa;
390 u32 index = PT64_INDEX(v, level);
393 ASSERT(VALID_PAGE(table_addr));
394 table = __va(table_addr);
397 mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
398 page_header_update_slot(vcpu->kvm, table, v);
399 table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
401 rmap_add(vcpu->kvm, &table[index]);
405 if (table[index] == 0) {
406 struct kvm_mmu_page *new_table;
408 new_table = kvm_mmu_alloc_page(vcpu, &table[index]);
410 pgprintk("nonpaging_map: ENOMEM\n");
414 table[index] = new_table->page_hpa | PT_PRESENT_MASK
415 | PT_WRITABLE_MASK | PT_USER_MASK;
417 table_addr = table[index] & PT64_BASE_ADDR_MASK;
421 static void mmu_free_roots(struct kvm_vcpu *vcpu)
426 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
427 hpa_t root = vcpu->mmu.root_hpa;
429 ASSERT(VALID_PAGE(root));
430 release_pt_page_64(vcpu, root, PT64_ROOT_LEVEL);
431 vcpu->mmu.root_hpa = INVALID_PAGE;
435 for (i = 0; i < 4; ++i) {
436 hpa_t root = vcpu->mmu.pae_root[i];
438 ASSERT(VALID_PAGE(root));
439 root &= PT64_BASE_ADDR_MASK;
440 release_pt_page_64(vcpu, root, PT32E_ROOT_LEVEL - 1);
441 vcpu->mmu.pae_root[i] = INVALID_PAGE;
443 vcpu->mmu.root_hpa = INVALID_PAGE;
446 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
451 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
452 hpa_t root = vcpu->mmu.root_hpa;
454 ASSERT(!VALID_PAGE(root));
455 root = kvm_mmu_alloc_page(vcpu, NULL)->page_hpa;
456 vcpu->mmu.root_hpa = root;
460 for (i = 0; i < 4; ++i) {
461 hpa_t root = vcpu->mmu.pae_root[i];
463 ASSERT(!VALID_PAGE(root));
464 root = kvm_mmu_alloc_page(vcpu, NULL)->page_hpa;
465 vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
467 vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
470 static void nonpaging_flush(struct kvm_vcpu *vcpu)
472 hpa_t root = vcpu->mmu.root_hpa;
474 ++kvm_stat.tlb_flush;
475 pgprintk("nonpaging_flush\n");
476 mmu_free_roots(vcpu);
477 mmu_alloc_roots(vcpu);
478 kvm_arch_ops->set_cr3(vcpu, root);
479 kvm_arch_ops->tlb_flush(vcpu);
482 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
487 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
494 ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
499 paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK);
501 if (is_error_hpa(paddr))
504 ret = nonpaging_map(vcpu, addr & PAGE_MASK, paddr);
506 nonpaging_flush(vcpu);
514 static void nonpaging_inval_page(struct kvm_vcpu *vcpu, gva_t addr)
518 static void nonpaging_free(struct kvm_vcpu *vcpu)
520 mmu_free_roots(vcpu);
523 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
525 struct kvm_mmu *context = &vcpu->mmu;
527 context->new_cr3 = nonpaging_new_cr3;
528 context->page_fault = nonpaging_page_fault;
529 context->inval_page = nonpaging_inval_page;
530 context->gva_to_gpa = nonpaging_gva_to_gpa;
531 context->free = nonpaging_free;
532 context->root_level = PT32E_ROOT_LEVEL;
533 context->shadow_root_level = PT32E_ROOT_LEVEL;
534 mmu_alloc_roots(vcpu);
535 ASSERT(VALID_PAGE(context->root_hpa));
536 kvm_arch_ops->set_cr3(vcpu, context->root_hpa);
541 static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
543 struct kvm_mmu_page *page, *npage;
545 list_for_each_entry_safe(page, npage, &vcpu->kvm->active_mmu_pages,
550 if (!page->parent_pte)
553 *page->parent_pte = 0;
554 release_pt_page_64(vcpu, page->page_hpa, 1);
556 ++kvm_stat.tlb_flush;
557 kvm_arch_ops->tlb_flush(vcpu);
560 static void paging_new_cr3(struct kvm_vcpu *vcpu)
562 kvm_mmu_flush_tlb(vcpu);
565 static void mark_pagetable_nonglobal(void *shadow_pte)
567 page_header(__pa(shadow_pte))->global = 0;
570 static inline void set_pte_common(struct kvm_vcpu *vcpu,
578 *shadow_pte |= access_bits << PT_SHADOW_BITS_OFFSET;
580 access_bits &= ~PT_WRITABLE_MASK;
582 if (access_bits & PT_WRITABLE_MASK)
583 mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT);
585 *shadow_pte |= access_bits;
587 paddr = gpa_to_hpa(vcpu, gaddr & PT64_BASE_ADDR_MASK);
589 if (!(*shadow_pte & PT_GLOBAL_MASK))
590 mark_pagetable_nonglobal(shadow_pte);
592 if (is_error_hpa(paddr)) {
593 *shadow_pte |= gaddr;
594 *shadow_pte |= PT_SHADOW_IO_MARK;
595 *shadow_pte &= ~PT_PRESENT_MASK;
597 *shadow_pte |= paddr;
598 page_header_update_slot(vcpu->kvm, shadow_pte, gaddr);
599 rmap_add(vcpu->kvm, shadow_pte);
603 static void inject_page_fault(struct kvm_vcpu *vcpu,
607 kvm_arch_ops->inject_page_fault(vcpu, addr, err_code);
610 static inline int fix_read_pf(u64 *shadow_ent)
612 if ((*shadow_ent & PT_SHADOW_USER_MASK) &&
613 !(*shadow_ent & PT_USER_MASK)) {
615 * If supervisor write protect is disabled, we shadow kernel
616 * pages as user pages so we can trap the write access.
618 *shadow_ent |= PT_USER_MASK;
619 *shadow_ent &= ~PT_WRITABLE_MASK;
627 static int may_access(u64 pte, int write, int user)
630 if (user && !(pte & PT_USER_MASK))
632 if (write && !(pte & PT_WRITABLE_MASK))
638 * Remove a shadow pte.
640 static void paging_inval_page(struct kvm_vcpu *vcpu, gva_t addr)
642 hpa_t page_addr = vcpu->mmu.root_hpa;
643 int level = vcpu->mmu.shadow_root_level;
648 u32 index = PT64_INDEX(addr, level);
649 u64 *table = __va(page_addr);
651 if (level == PT_PAGE_TABLE_LEVEL ) {
652 rmap_remove(vcpu->kvm, &table[index]);
657 if (!is_present_pte(table[index]))
660 page_addr = table[index] & PT64_BASE_ADDR_MASK;
662 if (level == PT_DIRECTORY_LEVEL &&
663 (table[index] & PT_SHADOW_PS_MARK)) {
665 release_pt_page_64(vcpu, page_addr, PT_PAGE_TABLE_LEVEL);
667 kvm_arch_ops->tlb_flush(vcpu);
673 static void paging_free(struct kvm_vcpu *vcpu)
675 nonpaging_free(vcpu);
679 #include "paging_tmpl.h"
683 #include "paging_tmpl.h"
686 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
688 struct kvm_mmu *context = &vcpu->mmu;
690 ASSERT(is_pae(vcpu));
691 context->new_cr3 = paging_new_cr3;
692 context->page_fault = paging64_page_fault;
693 context->inval_page = paging_inval_page;
694 context->gva_to_gpa = paging64_gva_to_gpa;
695 context->free = paging_free;
696 context->root_level = level;
697 context->shadow_root_level = level;
698 mmu_alloc_roots(vcpu);
699 ASSERT(VALID_PAGE(context->root_hpa));
700 kvm_arch_ops->set_cr3(vcpu, context->root_hpa |
701 (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)));
705 static int paging64_init_context(struct kvm_vcpu *vcpu)
707 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
710 static int paging32_init_context(struct kvm_vcpu *vcpu)
712 struct kvm_mmu *context = &vcpu->mmu;
714 context->new_cr3 = paging_new_cr3;
715 context->page_fault = paging32_page_fault;
716 context->inval_page = paging_inval_page;
717 context->gva_to_gpa = paging32_gva_to_gpa;
718 context->free = paging_free;
719 context->root_level = PT32_ROOT_LEVEL;
720 context->shadow_root_level = PT32E_ROOT_LEVEL;
721 mmu_alloc_roots(vcpu);
722 ASSERT(VALID_PAGE(context->root_hpa));
723 kvm_arch_ops->set_cr3(vcpu, context->root_hpa |
724 (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)));
728 static int paging32E_init_context(struct kvm_vcpu *vcpu)
730 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
733 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
736 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
738 if (!is_paging(vcpu))
739 return nonpaging_init_context(vcpu);
740 else if (is_long_mode(vcpu))
741 return paging64_init_context(vcpu);
742 else if (is_pae(vcpu))
743 return paging32E_init_context(vcpu);
745 return paging32_init_context(vcpu);
748 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
751 if (VALID_PAGE(vcpu->mmu.root_hpa)) {
752 vcpu->mmu.free(vcpu);
753 vcpu->mmu.root_hpa = INVALID_PAGE;
757 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
759 destroy_kvm_mmu(vcpu);
760 return init_kvm_mmu(vcpu);
763 static void free_mmu_pages(struct kvm_vcpu *vcpu)
765 while (!list_empty(&vcpu->free_pages)) {
766 struct kvm_mmu_page *page;
768 page = list_entry(vcpu->free_pages.next,
769 struct kvm_mmu_page, link);
770 list_del(&page->link);
771 __free_page(pfn_to_page(page->page_hpa >> PAGE_SHIFT));
772 page->page_hpa = INVALID_PAGE;
774 free_page((unsigned long)vcpu->mmu.pae_root);
777 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
784 for (i = 0; i < KVM_NUM_MMU_PAGES; i++) {
785 struct kvm_mmu_page *page_header = &vcpu->page_header_buf[i];
787 INIT_LIST_HEAD(&page_header->link);
788 if ((page = alloc_page(GFP_KERNEL)) == NULL)
790 page->private = (unsigned long)page_header;
791 page_header->page_hpa = (hpa_t)page_to_pfn(page) << PAGE_SHIFT;
792 memset(__va(page_header->page_hpa), 0, PAGE_SIZE);
793 list_add(&page_header->link, &vcpu->free_pages);
797 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
798 * Therefore we need to allocate shadow page tables in the first
799 * 4GB of memory, which happens to fit the DMA32 zone.
801 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
804 vcpu->mmu.pae_root = page_address(page);
805 for (i = 0; i < 4; ++i)
806 vcpu->mmu.pae_root[i] = INVALID_PAGE;
811 free_mmu_pages(vcpu);
815 int kvm_mmu_create(struct kvm_vcpu *vcpu)
818 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
819 ASSERT(list_empty(&vcpu->free_pages));
821 return alloc_mmu_pages(vcpu);
824 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
827 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
828 ASSERT(!list_empty(&vcpu->free_pages));
830 return init_kvm_mmu(vcpu);
833 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
837 destroy_kvm_mmu(vcpu);
838 free_mmu_pages(vcpu);
841 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
843 struct kvm_mmu_page *page;
845 list_for_each_entry(page, &kvm->active_mmu_pages, link) {
849 if (!test_bit(slot, &page->slot_bitmap))
852 pt = __va(page->page_hpa);
853 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
855 if (pt[i] & PT_WRITABLE_MASK) {
856 rmap_remove(kvm, &pt[i]);
857 pt[i] &= ~PT_WRITABLE_MASK;