KVM: MMU: delay local tlb flush

delay local tlb flush until enter guest moden, it can reduce vpid flush
frequency and reduce remote tlb flush IPI(if KVM_REQ_TLB_FLUSH bit is
already set, IPI is not sent)

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 731909818d91f463a45ba2c848d16d0b727f803a..75ddaa100c462da70781311d25a1962065814ed0 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2362,7 +2362,7 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu)
 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
 {
        ++vcpu->stat.tlb_flush;
-       kvm_x86_ops->tlb_flush(vcpu);
+       set_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests);
 }
 
 static void paging_new_cr3(struct kvm_vcpu *vcpu)