KVM: MMU: fix walking shadow page table
Properly check the last mapping, and do not walk to the next level if last spte
is met
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index da0f3b0..03323dc 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1517,10 +1517,6 @@
if (iterator->level < PT_PAGE_TABLE_LEVEL)
return false;
- if (iterator->level == PT_PAGE_TABLE_LEVEL)
- if (is_large_pte(*iterator->sptep))
- return false;
-
iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);
iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index;
return true;
@@ -1528,6 +1524,11 @@
static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
{
+ if (is_last_spte(*iterator->sptep, iterator->level)) {
+ iterator->level = 0;
+ return;
+ }
+
iterator->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK;
--iterator->level;
}