Hi Radim, On Mon, Sep 15, 2014 at 09:33:52PM +0200, Radim Krčmář wrote: >2014-09-12 17:06-0400, Liang Chen: >> Using kvm_mmu_flush_tlb as the other places to make sure vcpu >> stat is incremented >> >> Signed-off-by: Liang Chen <[email protected]> >> --- > >Good catch. > >> arch/x86/kvm/vmx.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index bfe11cf..439682e 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -1810,7 +1810,7 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int >> cpu) >> struct desc_ptr *gdt = &__get_cpu_var(host_gdt); >> unsigned long sysenter_esp; >> >> - kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); >> + kvm_mmu_flush_tlb(vcpu); >> local_irq_disable(); >> crash_disable_local_vmclear(cpu); >> > >And to hijack this thread ... >I noticed three other deficits in stat.tlb_flush, patch below. > >Do you prefer the current behavior? > >--- 8< --- >KVM: x86: count actual tlb flushes > >- we count KVM_REQ_TLB_FLUSH requests, not actual flushes
So there maybe multiple requests accumulated at the point of kvm_check_request, if your patch account these accumulations correctly? Regards, Wanpeng Li > (KVM can have multiple requests for one flush) >- flushes from kvm_flush_remote_tlbs aren't counted >- it's easy to make a direct request by mistake > >Solve these by postponing the counting to kvm_check_request(). > >Signed-off-by: Radim Krčmář <[email protected]> >--- >(And what about a possible followup patch that replaces > kvm_mmu_flush_tlb() with kvm_make_request() again? > It would free the namespace a bit and we could call something > similarly named from vcpu_enter_guest() to do the job.) > >diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >index 9314678..b41fd97 100644 >--- a/arch/x86/kvm/mmu.c >+++ b/arch/x86/kvm/mmu.c >@@ -3452,7 +3452,6 @@ static void nonpaging_init_context(struct kvm_vcpu *vcpu, > > void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu) > { >- ++vcpu->stat.tlb_flush; > kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); > } > EXPORT_SYMBOL_GPL(kvm_mmu_flush_tlb); >diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >index 916e895..0f0ad08 100644 >--- a/arch/x86/kvm/x86.c >+++ b/arch/x86/kvm/x86.c >@@ -6041,8 +6041,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > } > if (kvm_check_request(KVM_REQ_MMU_SYNC, vcpu)) > kvm_mmu_sync_roots(vcpu); >- if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) >+ if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) { >+ ++vcpu->stat.tlb_flush; > kvm_x86_ops->tlb_flush(vcpu); >+ } > if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) { > vcpu->run->exit_reason = KVM_EXIT_TPR_ACCESS; > r = 0; >-- >To unsubscribe from this list: send the line "unsubscribe kvm" in >the body of a message to [email protected] >More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
