diff options
| -rw-r--r-- | drivers/kvm/mmu.c | 47 |
1 files changed, 35 insertions, 12 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index 22c426cd8cb..1e09d4e3b05 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -1093,22 +1093,40 @@ out: return r; } +static void mmu_pre_write_zap_pte(struct kvm_vcpu *vcpu, + struct kvm_mmu_page *page, + u64 *spte) +{ + u64 pte; + struct kvm_mmu_page *child; + + pte = *spte; + if (is_present_pte(pte)) { + if (page->role.level == PT_PAGE_TABLE_LEVEL) + rmap_remove(vcpu, spte); + else { + child = page_header(pte & PT64_BASE_ADDR_MASK); + mmu_page_remove_parent_pte(vcpu, child, spte); + } + } + *spte = 0; +} + void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) { gfn_t gfn = gpa >> PAGE_SHIFT; struct kvm_mmu_page *page; - struct kvm_mmu_page *child; struct hlist_node *node, *n; struct hlist_head *bucket; unsigned index; u64 *spte; - u64 pte; unsigned offset = offset_in_page(gpa); unsigned pte_size; unsigned page_offset; unsigned misaligned; int level; int flooded = 0; + int npte; pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes); if (gfn == vcpu->last_pt_write_gfn) { @@ -1144,22 +1162,27 @@ void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) } page_offset = offset; level = page->role.level; + npte = 1; if (page->role.glevels == PT32_ROOT_LEVEL) { - page_offset <<= 1; /* 32->64 */ + page_offset <<= 1; /* 32->64 */ + /* + * A 32-bit pde maps 4MB while the shadow pdes map + * only 2MB. So we need to double the offset again + * and zap two pdes instead of one. + */ + if (level == PT32_ROOT_LEVEL) { + page_offset &= ~7; /* kill rounding error */ + page_offset <<= 1; + npte = 2; + } page_offset &= ~PAGE_MASK; } spte = __va(page->page_hpa); spte += page_offset / sizeof(*spte); - pte = *spte; - if (is_present_pte(pte)) { - if (level == PT_PAGE_TABLE_LEVEL) - rmap_remove(vcpu, spte); - else { - child = page_header(pte & PT64_BASE_ADDR_MASK); - mmu_page_remove_parent_pte(vcpu, child, spte); - } + while (npte--) { + mmu_pre_write_zap_pte(vcpu, page, spte); + ++spte; } - *spte = 0; } } |