KVM: MMU: Add cache miss statistic

Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 9a57e1a..8f12ec5 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -715,6 +715,7 @@
 			pgprintk("%s: found\n", __FUNCTION__);
 			return sp;
 		}
+	++vcpu->kvm->stat.mmu_cache_miss;
 	sp = kvm_mmu_alloc_page(vcpu, parent_pte);
 	if (!sp)
 		return sp;