KVM: MMU: make for_each_shadow_entry aware of largepages

This way there is no need to add explicit checks in every
for_each_shadow_entry user.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/mmu.c

@@ -1302,6 +1302,11 @@ static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)
 {
 	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;