[libvirt] [PATCH v3 01/11] qemu: Add support for DUMP_COMPLETED event
John Ferlan
jferlan at redhat.com
Thu Feb 1 23:18:56 UTC 2018
On 02/01/2018 09:37 AM, Jiri Denemark wrote:
> On Mon, Jan 29, 2018 at 11:31:59 -0500, John Ferlan wrote:
>> The event will be fired when the domain memory only dump completes.
>>
>> Alloc a return buffer to store/pass along the dump statistics that
>> will be eventually shared by a query-dump command.
>>
>> Signed-off-by: John Ferlan <jferlan at redhat.com>
>> ---
>> src/qemu/qemu_monitor.c | 29 ++++++++++++++++++++
>> src/qemu/qemu_monitor.h | 31 +++++++++++++++++++++
>> src/qemu/qemu_monitor_json.c | 65 ++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 125 insertions(+)
>>
>> diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
>> index fc146bdbf..23153967c 100644
>> --- a/src/qemu/qemu_monitor.c
>> +++ b/src/qemu/qemu_monitor.c
>> @@ -210,6 +210,10 @@ VIR_ENUM_IMPL(qemuMonitorBlockIOStatus,
>> QEMU_MONITOR_BLOCK_IO_STATUS_LAST,
>> "ok", "failed", "nospace")
>>
>> +VIR_ENUM_IMPL(qemuMonitorDumpStatus,
>> + QEMU_MONITOR_DUMP_STATUS_LAST,
>> + "none", "active", "completed", "failed")
>> +
>> char *
>> qemuMonitorEscapeArg(const char *in)
>> {
>> @@ -1667,6 +1671,21 @@ qemuMonitorEmitBlockThreshold(qemuMonitorPtr mon,
>>
>>
>> int
>> +qemuMonitorEmitDumpCompleted(qemuMonitorPtr mon,
>> + qemuMonitorDumpStatsPtr stats,
>> + const char *error)
>> +{
>> + int ret = -1;
>> +
>> + VIR_DEBUG("mon=%p", mon);
>> +
>> + QEMU_MONITOR_CALLBACK(mon, ret, domainDumpCompleted, mon->vm, stats, error);
>> +
>> + return ret;
>> +}
>> +
>> +
>> +int
>> qemuMonitorSetCapabilities(qemuMonitorPtr mon)
>> {
>> QEMU_CHECK_MONITOR(mon);
>> @@ -4359,3 +4378,13 @@ qemuMonitorSetWatchdogAction(qemuMonitorPtr mon,
>>
>> return qemuMonitorJSONSetWatchdogAction(mon, action);
>> }
>> +
>> +
>> +void
>> +qemuMonitorEventDumpStatsFree(qemuMonitorDumpStatsPtr stats)
>> +{
>> + if (!stats)
>> + return;
>> +
>> + VIR_FREE(stats);
>> +}
>
> The caller can just use VIR_FREE() directly and benefit from it
> automatically resetting the pointer to NULL. Anyway, I don't think we
> need to ever free this structure.
>
I was following (to a degree) qemuMonitorJSONHandleGuestPanic...
>> diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
>> index 67b785e60..37f335e9f 100644
>> --- a/src/qemu/qemu_monitor.h
>> +++ b/src/qemu/qemu_monitor.h
>> @@ -246,6 +246,30 @@ typedef int (*qemuMonitorDomainBlockThresholdCallback)(qemuMonitorPtr mon,
>> unsigned long long excess,
>> void *opaque);
>>
>> +typedef enum {
>> + QEMU_MONITOR_DUMP_STATUS_NONE,
>> + QEMU_MONITOR_DUMP_STATUS_ACTIVE,
>> + QEMU_MONITOR_DUMP_STATUS_COMPLETED,
>> + QEMU_MONITOR_DUMP_STATUS_FAILED,
>> +
>> + QEMU_MONITOR_DUMP_STATUS_LAST,
>> +} qemuMonitorDumpStatus;
>> +
>> +VIR_ENUM_DECL(qemuMonitorDumpStatus)
>> +
>> +typedef struct _qemuMonitorDumpStats qemuMonitorDumpStats;
>> +typedef qemuMonitorDumpStats *qemuMonitorDumpStatsPtr;
>> +struct _qemuMonitorDumpStats {
>> + int status; /* qemuMonitorDumpStatus */
>> + unsigned long long completed; /* bytes written */
>> + unsigned long long total; /* total bytes to be written */
>> +};
>> +
>> +typedef int (*qemuMonitorDomainDumpCompletedCallback)(qemuMonitorPtr mon,
>> + virDomainObjPtr vm,
>> + qemuMonitorDumpStatsPtr stats,
>> + const char *error,
>> + void *opaque);
>>
>> typedef struct _qemuMonitorCallbacks qemuMonitorCallbacks;
>> typedef qemuMonitorCallbacks *qemuMonitorCallbacksPtr;
>> @@ -279,6 +303,7 @@ struct _qemuMonitorCallbacks {
>> qemuMonitorDomainMigrationPassCallback domainMigrationPass;
>> qemuMonitorDomainAcpiOstInfoCallback domainAcpiOstInfo;
>> qemuMonitorDomainBlockThresholdCallback domainBlockThreshold;
>> + qemuMonitorDomainDumpCompletedCallback domainDumpCompleted;
>> };
>>
>> char *qemuMonitorEscapeArg(const char *in);
>> @@ -408,6 +433,10 @@ int qemuMonitorEmitBlockThreshold(qemuMonitorPtr mon,
>> unsigned long long threshold,
>> unsigned long long excess);
>>
>> +int qemuMonitorEmitDumpCompleted(qemuMonitorPtr mon,
>> + qemuMonitorDumpStatsPtr stats,
>> + const char *error);
>> +
>> int qemuMonitorStartCPUs(qemuMonitorPtr mon,
>> virConnectPtr conn);
>> int qemuMonitorStopCPUs(qemuMonitorPtr mon);
>> @@ -1146,4 +1175,6 @@ virJSONValuePtr qemuMonitorQueryNamedBlockNodes(qemuMonitorPtr mon);
>>
>> int qemuMonitorSetWatchdogAction(qemuMonitorPtr mon,
>> const char *action);
>> +
>> +void qemuMonitorEventDumpStatsFree(qemuMonitorDumpStatsPtr stats);
>> #endif /* QEMU_MONITOR_H */
>> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
>> index 5ddd85575..a8cb8ce6b 100644
>> --- a/src/qemu/qemu_monitor_json.c
>> +++ b/src/qemu/qemu_monitor_json.c
>> @@ -90,6 +90,7 @@ static void qemuMonitorJSONHandleMigrationStatus(qemuMonitorPtr mon, virJSONValu
>> static void qemuMonitorJSONHandleMigrationPass(qemuMonitorPtr mon, virJSONValuePtr data);
>> static void qemuMonitorJSONHandleAcpiOstInfo(qemuMonitorPtr mon, virJSONValuePtr data);
>> static void qemuMonitorJSONHandleBlockThreshold(qemuMonitorPtr mon, virJSONValuePtr data);
>> +static void qemuMonitorJSONHandleDumpCompleted(qemuMonitorPtr mon, virJSONValuePtr data);
>>
>> typedef struct {
>> const char *type;
>> @@ -106,6 +107,7 @@ static qemuEventHandler eventHandlers[] = {
>> { "BLOCK_WRITE_THRESHOLD", qemuMonitorJSONHandleBlockThreshold, },
>> { "DEVICE_DELETED", qemuMonitorJSONHandleDeviceDeleted, },
>> { "DEVICE_TRAY_MOVED", qemuMonitorJSONHandleTrayChange, },
>> + { "DUMP_COMPLETED", qemuMonitorJSONHandleDumpCompleted, },
>> { "GUEST_PANICKED", qemuMonitorJSONHandleGuestPanic, },
>> { "MIGRATION", qemuMonitorJSONHandleMigrationStatus, },
>> { "MIGRATION_PASS", qemuMonitorJSONHandleMigrationPass, },
>> @@ -1143,6 +1145,69 @@ qemuMonitorJSONHandleBlockThreshold(qemuMonitorPtr mon, virJSONValuePtr data)
>> }
>>
>>
>> +static qemuMonitorDumpStatsPtr
>> +qemuMonitorJSONExtractDumpStats(virJSONValuePtr result)
>> +{
>> + qemuMonitorDumpStatsPtr ret;
>> + const char *statusstr;
>> +
>> + if (VIR_ALLOC(ret) < 0)
>> + return NULL;
>
> I think it would be better if this just worked on an existing reference
> to qemuMonitorDumpStats passed as an additional argument.
>
... OK - that's fine - I take that option instead and repost.
>> +
>> + if (!(statusstr = virJSONValueObjectGetString(result, "status"))) {
>> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> + _("incomplete result, failed to get status"));
>> + goto error;
>> + }
>> +
>> + ret->status = qemuMonitorDumpStatusTypeFromString(statusstr);
>> + if (ret->status < 0) {
>> + virReportError(VIR_ERR_INTERNAL_ERROR,
>> + _("incomplete result, unknown status string '%s'"),
>> + statusstr);
>> + goto error;
>> + }
>> +
>> + if (virJSONValueObjectGetNumberUlong(result, "completed", &ret->completed) < 0) {
>> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> + _("incomplete result, failed to get completed"));
>> + goto error;
>> + }
>> +
>> + if (virJSONValueObjectGetNumberUlong(result, "total", &ret->total) < 0) {
>> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> + _("incomplete result, failed to get total"));
>> + goto error;
>> + }
>> +
>> + return ret;
>> +
>> + error:
>> + qemuMonitorEventDumpStatsFree(ret);
>> + return NULL;
>> +}
>> +
>> +
>> +static void
>> +qemuMonitorJSONHandleDumpCompleted(qemuMonitorPtr mon,
>> + virJSONValuePtr data)
>> +{
>> + virJSONValuePtr result;
>> + qemuMonitorDumpStatsPtr stats = NULL;
>> + const char *error = NULL;
>> +
>> + if (!(result = virJSONValueObjectGetObject(data, "result"))) {
>> + VIR_WARN("missing result in dump completed event");
>> + return;
>> + }
>> +
>> + stats = qemuMonitorJSONExtractDumpStats(result);
>> + error = virJSONValueObjectGetString(data, "error");
>> +
>> + qemuMonitorEmitDumpCompleted(mon, stats, error);
>
> Using stats allocated on the stack would resolve the memory leak here.
>
Or as you found in patch 2, it was freed... Hazards of trying to extract
into small chunks of patches.
John
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