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Commit 052331be authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

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: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent d910f5c1

arch/x86/kvm/mmu.c

+5 −4
Original line number Original line Diff line number Diff line
@@ -1517,10 +1517,6 @@ static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 
	if (iterator->level < PT_PAGE_TABLE_LEVEL)

	if (iterator->level < PT_PAGE_TABLE_LEVEL)

		return false;

		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->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);

	iterator->sptep	= ((u64 *)__va(iterator->shadow_addr)) + iterator->index;

	iterator->sptep	= ((u64 *)__va(iterator->shadow_addr)) + iterator->index;

	return true;

	return true;
@@ -1528,6 +1524,11 @@ static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) 




static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)

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->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK;

	--iterator->level;

	--iterator->level;

}

}