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-rw-r--r--drivers/kvm/mmu.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index bce7eb21f73..6dbd83b8662 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)