KVM: MMU: Add cache miss statistic

Signed-off-by: NAvi Kivity <avi@qumranet.com>

arch/x86/kvm/mmu.c

@@ -715,6 +715,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 			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;

arch/x86/kvm/x86.c

@@ -73,6 +73,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	{ "mmu_pde_zapped", VM_STAT(mmu_pde_zapped) },
 	{ "mmu_flooded", VM_STAT(mmu_flooded) },
 	{ "mmu_recycled", VM_STAT(mmu_recycled) },
+	{ "mmu_cache_miss", VM_STAT(mmu_cache_miss) },
 	{ "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
 	{ NULL }
 };

include/asm-x86/kvm_host.h

@@ -289,6 +289,7 @@ struct kvm_vm_stat {
 	u32 mmu_pde_zapped;
 	u32 mmu_flooded;
 	u32 mmu_recycled;
+	u32 mmu_cache_miss;
 	u32 remote_tlb_flush;
 };