monitor: resurrect handle_qmp_command trace event

Commit 104fc302 ("qmp: Drop duplicated
QMP command object checks") removed the call to
trace_handle_qmp_command() while eliminating code duplication.

This patch brings the trace event back so QEMU-internal trace events can
be correlated with the QMP commands that caused them.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 20170605104216.22429-3-stefanha@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

monitor.c

@@ -3809,6 +3809,7 @@ static void handle_qmp_command(JSONMessageParser *parser, GQueue *tokens)
     QDict *qdict = NULL;
     Monitor *mon = cur_mon;
     Error *err = NULL;
+    QString *req_json;
 
     req = json_parser_parse_err(tokens, NULL, &err);
     if (!req && !err) {
@@ -3826,6 +3827,10 @@ static void handle_qmp_command(JSONMessageParser *parser, GQueue *tokens)
         qdict_del(qdict, "id");
     } /* else will fail qmp_dispatch() */
 
+    req_json = qobject_to_json(req);
+    trace_handle_qmp_command(mon, qstring_get_str(req_json));
+    qobject_decref(QOBJECT(req_json));
+
     rsp = qmp_dispatch(cur_mon->qmp.commands, req);
 
     if (mon->qmp.commands == &qmp_cap_negotiation_commands) {

trace-events

@@ -46,6 +46,7 @@ monitor_protocol_event_handler(uint32_t event, void *qdict) "event=%d data=%p"
 monitor_protocol_event_emit(uint32_t event, void *data) "event=%d data=%p"
 monitor_protocol_event_queue(uint32_t event, void *qdict, uint64_t rate) "event=%d data=%p rate=%" PRId64
 handle_hmp_command(void *mon, const char *cmdline) "mon %p cmdline: %s"
+handle_qmp_command(void *mon, const char *req) "mon %p req: %s"
 
 # dma-helpers.c
 dma_blk_io(void *dbs, void *bs, int64_t offset, bool to_dev) "dbs=%p bs=%p offset=%" PRId64 " to_dev=%d"