From be233d49ea8c1fde9f4afec378dc2c2f16ab0263 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Fri, 16 Jul 2010 11:27:10 +0800 Subject: [PATCH] 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: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a04756a26fe2..9c7fae08291d 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -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))); -- 2.45.2