KVM: MMU: fix incorrect return of spte

__update_clear_spte_slow should return original spte while the
current code returns low half of original spte combined with high
half of new spte.

Signed-off-by: Zhao Jin <cronozhj@gmail.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Zhao Jin 2011-09-19 12:19:51 +08:00 committed by Avi Kivity
parent b172e38e43
commit 41bc3186b3

View file

@ -400,7 +400,8 @@ static u64 __update_clear_spte_slow(u64 *sptep, u64 spte)
/* xchg acts as a barrier before the setting of the high bits */
orig.spte_low = xchg(&ssptep->spte_low, sspte.spte_low);
orig.spte_high = ssptep->spte_high = sspte.spte_high;
orig.spte_high = ssptep->spte_high;
ssptep->spte_high = sspte.spte_high;
count_spte_clear(sptep, spte);
return orig.spte;