[libvirt] [PATCH 1/1] perf: list all supported events when get domain stats

[Qiaowei Ren]

Currently when virDomainListGetStats is called, the stats for those
disabled perf events won't be showed in result. This will produce
some problems for applications based on libvirt sometime, e.g. the
OpenStack bug https://bugs.launchpad.net/ceilometer/+bug/1670948

This patch just show '0' in result for disabled events for
virDomainListGetStats API. I guess this should be also rational to
show all stats even though the events are not enabled.

Signed-off-by: Qiaowei Ren <qiaowei.ren at intel.com>
---
 src/qemu/qemu_driver.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 2032fac..237bf57 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -19355,8 +19355,10 @@ qemuDomainGetStatsPerfOneEvent(virPerfPtr perf,
     char param_name[VIR_TYPED_PARAM_FIELD_LENGTH];
     uint64_t value = 0;
 
-    if (virPerfReadEvent(perf, type, &value) < 0)
-        return -1;
+    if (virPerfEventIsEnabled(perf, type)) {
+        if (virPerfReadEvent(perf, type, &value) < 0)
+            return -1;
+    }
 
     snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH, "perf.%s",
              virPerfEventTypeToString(type));
@@ -19383,9 +19385,6 @@ qemuDomainGetStatsPerf(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
     int ret = -1;
 
     for (i = 0; i < VIR_PERF_EVENT_LAST; i++) {
-        if (!virPerfEventIsEnabled(priv->perf, i))
-             continue;
-
         if (qemuDomainGetStatsPerfOneEvent(priv->perf, i,
                                            record, maxparams) < 0)
             goto cleanup;
-- 
1.9.1