tools lib traceevent: Factor out print_exit_reason in kvm plugin

We will reuse it for nested vmexit tracepoints.

Link: http://lkml.kernel.org/r/619c418c8af87f03027b8c8013b0443996605700.1388855989.git.jan.kiszka@web.deAcked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>

tools/lib/traceevent/plugin_kvm.c

@@ -244,15 +244,14 @@ static const char *find_exit_reason(unsigned isa, int val)
 	return strings[i].str;
 }
 
-static int kvm_exit_handler(struct trace_seq *s, struct pevent_record *record,
-			    struct event_format *event, void *context)
+static int print_exit_reason(struct trace_seq *s, struct pevent_record *record,
+			     struct event_format *event, const char *field)
 {
 	unsigned long long isa;
 	unsigned long long val;
-	unsigned long long info1 = 0, info2 = 0;
 	const char *reason;
 
-	if (pevent_get_field_val(s, event, "exit_reason", record, &val, 1) < 0)
+	if (pevent_get_field_val(s, event, field, record, &val, 1) < 0)
 		return -1;
 
 	if (pevent_get_field_val(s, event, "isa", record, &isa, 0) < 0)
@@ -263,6 +262,16 @@ static int kvm_exit_handler(struct trace_seq *s, struct pevent_record *record,
 		trace_seq_printf(s, "reason %s", reason);
 	else
 		trace_seq_printf(s, "reason UNKNOWN (%llu)", val);
+	return 0;
+}
+
+static int kvm_exit_handler(struct trace_seq *s, struct pevent_record *record,
+			    struct event_format *event, void *context)
+{
+	unsigned long long info1 = 0, info2 = 0;
+
+	if (print_exit_reason(s, record, event, "exit_reason") < 0)
+		return -1;
 
 	pevent_print_num_field(s, " rip 0x%lx", event, "guest_rip", record, 1);