KVM: Add statistic for remote tlb flushes

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

3 files changed, 5 insertions, 0 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index b65f5dee4b1b..048849d97b35 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -300,6 +300,7 @@ struct kvm_vm_stat {
         u32 mmu_pde_zapped;
         u32 mmu_flooded;
         u32 mmu_recycled;
+        u32 remote_tlb_flush;
 };
 
 struct kvm {
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 7939b5c9a4b4..aec6b67cfebb 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -115,6 +115,9 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
                 if (cpu != -1 && cpu != raw_smp_processor_id())
                         cpu_set(cpu, cpus);
         }
+        if (cpus_empty(cpus))
+                return;
+        ++kvm->stat.remote_tlb_flush;
         smp_call_function_mask(cpus, ack_flush, NULL, 1);
 }
 
diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index b482b6a8a828..ac09f381f47f 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/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) },
+        { "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
         { NULL }
 };