diff options
Diffstat (limited to 'drivers/kvm')
| -rw-r--r-- | drivers/kvm/mmu.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index bce7eb21f739..6dbd83b86623 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -958,7 +958,43 @@ int kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 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; + struct hlist_head *bucket; + unsigned index; + u64 *spte; + u64 pte; + unsigned offset = offset_in_page(gpa); + unsigned page_offset; + int level; + pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes); + index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; + bucket = &vcpu->kvm->mmu_page_hash[index]; + hlist_for_each_entry(page, node, bucket, hash_link) { + if (page->gfn != gfn || page->role.metaphysical) + continue; + page_offset = offset; + level = page->role.level; + if (page->role.glevels == PT32_ROOT_LEVEL) { + page_offset <<= 1; /* 32->64 */ + 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->kvm, spte); + else { + child = page_header(pte & PT64_BASE_ADDR_MASK); + mmu_page_remove_parent_pte(child, spte); + } + } + *spte = 0; + } } void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) |