Commit be233d49 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

KVM: MMU: don't atomicly set spte if it's not present 



If the old mapping is not present, the spte.a is not lost, so no need
atomic operation to set it

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 9ed5520d

arch/x86/kvm/mmu.c

+3 −2
Original line number Diff line number Diff line
@@ -307,9 +307,10 @@ static void update_spte(u64 *sptep, u64 new_spte) 
{

	u64 old_spte;



	if (!shadow_accessed_mask || (new_spte & shadow_accessed_mask)) {

	if (!shadow_accessed_mask || (new_spte & shadow_accessed_mask) ||

	      !is_rmap_spte(*sptep))

		__set_spte(sptep, new_spte);

	} else {

	else {

		old_spte = __xchg_spte(sptep, new_spte);

		if (old_spte & shadow_accessed_mask)

			mark_page_accessed(pfn_to_page(spte_to_pfn(old_spte)));