kvm: add tracepoint for fast mmio

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/trace.h

@@ -128,6 +128,24 @@ TRACE_EVENT(kvm_pio,
 		  __entry->count > 1 ? "(...)" : "")
 );
 
+/*
+ * Tracepoint for fast mmio.
+ */
+TRACE_EVENT(kvm_fast_mmio,
+	TP_PROTO(u64 gpa),
+	TP_ARGS(gpa),
+
+	TP_STRUCT__entry(
+		__field(u64,	gpa)
+	),
+
+	TP_fast_assign(
+		__entry->gpa		= gpa;
+	),
+
+	TP_printk("fast mmio at gpa 0x%llx", __entry->gpa)
+);
+
 /*
  * Tracepoint for cpuid.
  */