Messages in this thread Patch in this message | | | Date | Fri, 16 Jul 2010 11:27:10 +0800 | From | Xiao Guangrong <> | Subject | [PATCH v2 4/6] KVM: MMU: don't atomicly set spte if it's not present |
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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 <xiaoguangrong@cn.fujitsu.com> --- arch/x86/kvm/mmu.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index b3896bf..4123e8e 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))); -- 1.6.1.2
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