Messages in this thread Patch in this message | | | Date | Mon, 28 Mar 2011 10:30:42 +0800 | From | Xiao Guangrong <> | Subject | [PATCH 2/2] KVM: MMU: optimize pte write path if don't have protected sp |
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Simplely return from kvm_mmu_pte_write path if no shadow page is write-protected, than we can avoid to walk all shadow pages and hold mmu-lock
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> --- arch/x86/kvm/mmu.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 2841805..ccac6c4 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3219,6 +3219,11 @@ static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn) set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte); } +static bool need_track_pte_changed(struct kvm_vcpu *vcpu) +{ + return !tdp_enabled || mmu_is_nested(vcpu); +} + void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, int bytes, bool guest_initiated) @@ -3233,6 +3238,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, int level, npte, invlpg_counter, r, flooded = 0; bool remote_flush, local_flush, zap_page; + if (!need_track_pte_changed(vcpu)) + return; + zap_page = remote_flush = local_flush = false; offset = offset_in_page(gpa); -- 1.7.4
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