[PATCH] perf test 6: Fix missing kvm module load for s390

[PATCH] perf test 6: Fix missing kvm module load for s390

[Thomas Richter]

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>
---
 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 4a69c07f4101..8f3c80e13584 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);
@@ -1642,6 +1668,7 @@ 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
-- 
2.21.0

Re: [PATCH] perf test 6: Fix missing kvm module load for s390

[Arnaldo Carvalho de Melo]

Em Tue, Jun 04, 2019 at 07:35:04AM +0200, Thomas Richter escreveu:
> 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

Thanks, applied,

- Arnaldo
 
> 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>
> ---
>  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 4a69c07f4101..8f3c80e13584 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);
> @@ -1642,6 +1668,7 @@ 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
> -- 
> 2.21.0

-- 

- Arnaldo