[Qemu-devel] [PATCH 0/2] monitor: add trace events for HMP and QMP commands

[Qemu-devel] [PATCH 0/2] monitor: add trace events for HMP and QMP commands

[Stefan Hajnoczi]

It's nice to have HMP and QMP commands as part of a trace log.  This makes it
possible to correlate QEMU-internal events with the monitor commands that
caused them.

Stefan Hajnoczi (2):
  monitor: add handle_hmp_command trace event
  monitor: resurrect handle_qmp_command trace event

 monitor.c    | 7 +++++++
 trace-events | 2 ++
 2 files changed, 9 insertions(+)

-- 
2.9.4

[Qemu-devel] [PATCH 1/2] monitor: add handle_hmp_command trace event

[Stefan Hajnoczi]

It is often useful to correlate QEMU-internal events with monitor
commands that caused them.  Trace the full HMP command being executed.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 monitor.c    | 2 ++
 trace-events | 1 +
 2 files changed, 3 insertions(+)

diff --git a/monitor.c b/monitor.c
index baa73c9..1e78d86 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3085,6 +3085,8 @@ static void handle_hmp_command(Monitor *mon, const char *cmdline)
     QDict *qdict;
     const mon_cmd_t *cmd;
 
+    trace_handle_hmp_command(mon, cmdline);
+
     cmd = monitor_parse_command(mon, &cmdline, mon->cmd_table);
     if (!cmd) {
         return;
diff --git a/trace-events b/trace-events
index 433865f..2de6bec 100644
--- a/trace-events
+++ b/trace-events
@@ -52,6 +52,7 @@ spice_vmc_event(int event) "spice vmc event %d"
 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"
 
 # 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"
-- 
2.9.4

[Qemu-devel] [PATCH 2/2] monitor: resurrect handle_qmp_command trace event

[Stefan Hajnoczi]

Commit 104fc3027960dd2aa9d310936a6cb201c60e1088 ("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: Stefan Hajnoczi <stefanha@redhat.com>
---
 monitor.c    | 5 +++++
 trace-events | 1 +
 2 files changed, 6 insertions(+)

diff --git a/monitor.c b/monitor.c
index 1e78d86..e1105ea 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3806,6 +3806,7 @@ 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) {
@@ -3823,6 +3824,10 @@ 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) {
diff --git a/trace-events b/trace-events
index 2de6bec..d22e0ba 100644
--- a/trace-events
+++ b/trace-events
@@ -53,6 +53,7 @@ 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"
-- 
2.9.4

Re: [Qemu-devel] [PATCH 2/2] monitor: resurrect handle_qmp_command trace event

[Eric Blake]

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On 06/05/2017 05:42 AM, Stefan Hajnoczi wrote:
> Commit 104fc3027960dd2aa9d310936a6cb201c60e1088 ("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: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  monitor.c    | 5 +++++
>  trace-events | 1 +
>  2 files changed, 6 insertions(+)
> 

> @@ -3823,6 +3824,10 @@ 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));

I should really revive my patches that create a JSON output visitor, as
it would use less memory allocation in use cases like this.  But that's
not your problem.

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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Re: [Qemu-devel] [PATCH 1/2] monitor: add handle_hmp_command trace event

[Eric Blake]

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On 06/05/2017 05:42 AM, Stefan Hajnoczi wrote:
> It is often useful to correlate QEMU-internal events with monitor
> commands that caused them.  Trace the full HMP command being executed.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  monitor.c    | 2 ++
>  trace-events | 1 +
>  2 files changed, 3 insertions(+)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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Re: [Qemu-devel] [PATCH 0/2] monitor: add trace events for HMP and QMP commands

[Stefan Hajnoczi]

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On Mon, Jun 05, 2017 at 11:42:14AM +0100, Stefan Hajnoczi wrote:
> It's nice to have HMP and QMP commands as part of a trace log.  This makes it
> possible to correlate QEMU-internal events with the monitor commands that
> caused them.
> 
> Stefan Hajnoczi (2):
>   monitor: add handle_hmp_command trace event
>   monitor: resurrect handle_qmp_command trace event
> 
>  monitor.c    | 7 +++++++
>  trace-events | 2 ++
>  2 files changed, 9 insertions(+)

Thanks, applied to my tracing tree:
https://github.com/stefanha/qemu/commits/tracing

Stefan

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