[PATCH AUTOSEL 4.19 053/158] perf test 6: Fix missing kvm module load for s390

Sasha Levin
2019-07-15T14:20:54Z

From: Thomas Richter <tmricht@linux.ibm.com>

[ Upstream commit 53fe307dfd309e425b171f6272d64296a54f4dff ]

Command

# perf test -Fv 6

fails with error

running test 100 'kvm-s390:kvm_s390_create_vm' failed to parse
event 'kvm-s390:kvm_s390_create_vm', err -1, str 'unknown tracepoint'
event syntax error: 'kvm-s390:kvm_s390_create_vm'
\___ unknown tracepoint

when the kvm module is not loaded or not built in.

Fix this by adding a valid function which tests if the module
is loaded. Loaded modules (or builtin KVM support) have a
directory named
/sys/kernel/debug/tracing/events/kvm-s390
for this tracepoint.

Check for existence of this directory.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20190604053504.43073-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/tests/parse-events.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 3b97ac018d5a..532c95e8fa6b 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -18,6 +18,32 @@
#define PERF_TP_SAMPLE_TYPE (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME | \
PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD)

+#if defined(__s390x__)
+/* Return true if kvm module is available and loaded. Test this
+ * and retun success when trace point kvm_s390_create_vm
+ * exists. Otherwise this test always fails.
+ */
+static bool kvm_s390_create_vm_valid(void)
+{
+ char *eventfile;
+ bool rc = false;
+
+ eventfile = get_events_file("kvm-s390");
+
+ if (eventfile) {
+ DIR *mydir = opendir(eventfile);
+
+ if (mydir) {
+ rc = true;
+ closedir(mydir);
+ }
+ put_events_file(eventfile);
+ }
+
+ return rc;
+}
+#endif
+
static int test__checkevent_tracepoint(struct perf_evlist *evlist)
{
struct perf_evsel *evsel = perf_evlist__first(evlist);
@@ -1622,6 +1648,7 @@ static struct evlist_test test__events[] = {
{
.name = "kvm-s390:kvm_s390_create_vm",
.check = test__checkevent_tracepoint,
+ .valid = kvm_s390_create_vm_valid,
.id = 100,
},
#endif
--
2.20.1