KVM: x86: count actual tlb flushes

- we count KVM_REQ_TLB_FLUSH requests, not actual flushes
  (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 <rkrcmar@redhat.com>
Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 76398fe..90f0ace 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3446,7 +3446,6 @@ 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 e46da50..65b97d5 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6019,6 +6019,12 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
        kvm_apic_update_tmr(vcpu, tmr);
 }
 
+static void kvm_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
+{
+       ++vcpu->stat.tlb_flush;
+       kvm_x86_ops->tlb_flush(vcpu);
+}
+
 /*
  * Returns 1 to let __vcpu_run() continue the guest execution loop without
  * exiting to the userspace.  Otherwise, the value will be returned to the
@@ -6048,7 +6054,7 @@ 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))
-                       kvm_x86_ops->tlb_flush(vcpu);
+                       kvm_vcpu_flush_tlb(vcpu);
                if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) {
                        vcpu->run->exit_reason = KVM_EXIT_TPR_ACCESS;
                        r = 0;