tools lib traceevent: Report unknown VMX exit reasons with code

Allows to parse the result even if the KVM plugin does not yet
understand a specific exit code.

Link: http://lkml.kernel.org/r/5207446F.1090703@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

@@ -240,9 +240,8 @@ static const char *find_exit_reason(unsigned isa, int val)
 	for (i = 0; strings[i].val >= 0; i++)
 		if (strings[i].val == val)
 			break;
-	if (strings[i].str)
-		return strings[i].str;
-	return "UNKNOWN";
+
+	return strings[i].str;
 }
 
 static int kvm_exit_handler(struct trace_seq *s, struct pevent_record *record,
@@ -251,6 +250,7 @@ static int kvm_exit_handler(struct trace_seq *s, struct pevent_record *record,
 	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)
 		return -1;
@@ -258,7 +258,11 @@ static int kvm_exit_handler(struct trace_seq *s, struct pevent_record *record,
 	if (pevent_get_field_val(s, event, "isa", record, &isa, 0) < 0)
 		isa = 1;
 
-	trace_seq_printf(s, "reason %s", find_exit_reason(isa, val));
+	reason = find_exit_reason(isa, val);
+	if (reason)
+		trace_seq_printf(s, "reason %s", reason);
+	else
+		trace_seq_printf(s, "reason UNKNOWN (%llu)", val);
 
 	pevent_print_num_field(s, " rip 0x%lx", event, "guest_rip", record, 1);