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[PATCH 5/5] trace: add qmp trace event namespace
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[PATCH 5/5] trace: add qmp trace event namespace |
Date: |
Thu, 23 Sep 2021 22:54:51 +0300 |
Add a possibility to trace some qmp commands by user selection.
User API is simple: it looks like after this patch we have trace-points
for all qmp commands, in format "qmp:<qmp-command>". So user may do
--trace qmp:drive-backup
or run qmp command trace-event-set-state with arguments
name="qmp:drive-backup", enable=true
Patterns are supported in the same way as for general trace events, for
example:
--trace "qmp:query-*"
to cover query-block, query-block-jobs, and a lot of other query-
commands
or
--trace "qmp:job-*" --trace "qmp:block-job-*"
to cover job manipulation commands.
Trace event qmp covers both qmp command call and its respond.
Implementation details:
In qmp_dispatch() we add two trace points, similar to
trace_handle_qmp_command. We also check for cmd->tracking field being
set, and for handle-qmp-command/monitor-qmp-respond trace points being
disabled, to not print same information twice.
For qmp trace-event-{get,set}-state and for command line
parse additionally new "qmp:" namespace
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
qapi/qmp-dispatch.c | 20 ++++++++++++++++++++
softmmu/vl.c | 21 ++++++++++++++++++++-
trace/qmp.c | 20 ++++++++++++++++++++
qapi/trace-events | 2 ++
4 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index 59600210ce..40fd008fa8 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -26,6 +26,9 @@
#include "qemu/coroutine.h"
#include "qemu/main-loop.h"
+#include "trace.h"
+#include "trace/trace-monitor.h"
+
CompatPolicy compat_policy;
Visitor *qobject_input_visitor_new_qmp(QObject *obj)
@@ -133,6 +136,12 @@ static void do_qmp_dispatch_bh(void *opaque)
aio_co_wake(data->co);
}
+static void do_trace_qmp(const char *what, QObject *obj)
+{
+ g_autoptr(GString) req_json = qobject_to_json(obj);
+ trace_qmp(what, req_json->str);
+}
+
/*
* Runs outside of coroutine context for OOB commands, but in coroutine
* context for everything else.
@@ -176,6 +185,11 @@ QDict *qmp_dispatch(const QmpCommandList *cmds, QObject
*request,
"The command %s has not been found", command);
goto out;
}
+ if (!trace_event_get_state_backends(TRACE_HANDLE_QMP_COMMAND) &&
+ trace_event_get_state_backends(TRACE_QMP) && cmd->tracing)
+ {
+ do_trace_qmp(">>", request);
+ }
if (cmd->options & QCO_DEPRECATED) {
switch (compat_policy.deprecated_input) {
case COMPAT_POLICY_INPUT_ACCEPT:
@@ -282,5 +296,11 @@ out:
qdict_put_obj(rsp, "id", qobject_ref(id));
}
+ if (!trace_event_get_state_backends(TRACE_MONITOR_QMP_RESPOND) &&
+ trace_event_get_state_backends(TRACE_QMP) && cmd->tracing)
+ {
+ do_trace_qmp("<<", QOBJECT(rsp));
+ }
+
return rsp;
}
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 55ab70eb97..fd452b7013 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -2722,6 +2722,25 @@ void qmp_x_exit_preconfig(Error **errp)
}
}
+static void trace_opt_parse_with_qmp(const char *optarg)
+{
+ const char *pattern;
+ QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
+ optarg, true);
+ if (!opts) {
+ exit(1);
+ }
+
+ pattern = qemu_opt_get(opts, "enable");
+ if (pattern && !strncmp(pattern, "qmp:", 4)) {
+ monitor_qmp_set_tracing(pattern + 4, true);
+ qemu_opt_del_all(opts, "enable");
+ qemu_opt_set(opts, "enable", "qmp", &error_abort);
+ }
+
+ trace_opt_parse_opts(opts);
+}
+
void qemu_init(int argc, char **argv, char **envp)
{
QemuOpts *opts;
@@ -3480,7 +3499,7 @@ void qemu_init(int argc, char **argv, char **envp)
xen_domid_restrict = true;
break;
case QEMU_OPTION_trace:
- trace_opt_parse(optarg);
+ trace_opt_parse_with_qmp(optarg);
break;
case QEMU_OPTION_plugin:
qemu_plugin_opt_parse(optarg, &plugin_list);
diff --git a/trace/qmp.c b/trace/qmp.c
index 3b4f4702b4..87766422d9 100644
--- a/trace/qmp.c
+++ b/trace/qmp.c
@@ -11,6 +11,7 @@
#include "qapi/error.h"
#include "qapi/qapi-commands-trace.h"
#include "control-vcpu.h"
+#include "monitor/monitor.h"
static CPUState *get_cpu(bool has_vcpu, int vcpu, Error **errp)
@@ -77,6 +78,14 @@ TraceEventInfoList *qmp_trace_event_get_state(const char
*name,
bool is_pattern = trace_event_is_pattern(name);
CPUState *cpu;
+ if (!strncmp(name, "qmp:", 4)) {
+ if (!monitor_qmp_is_tracing_enabled(name + 4)) {
+ return NULL;
+ }
+
+ return qmp_trace_event_get_state("qmp", has_vcpu, vcpu, errp);
+ }
+
/* Check provided vcpu */
cpu = get_cpu(has_vcpu, vcpu, &err);
if (err) {
@@ -139,6 +148,17 @@ void qmp_trace_event_set_state(const char *name, bool
enable,
bool is_pattern = trace_event_is_pattern(name);
CPUState *cpu;
+ if (!strncmp(name, "qmp:", 4)) {
+ monitor_qmp_set_tracing(name + 4, enable);
+
+ if (enable || !monitor_qmp_is_tracing_enabled(NULL)) {
+ qmp_trace_event_set_state("qmp", enable, has_ignore_unavailable,
+ ignore_unavailable, has_vcpu, vcpu,
errp);
+ }
+
+ return;
+ }
+
/* Check provided vcpu */
cpu = get_cpu(has_vcpu, vcpu, &err);
if (err) {
diff --git a/qapi/trace-events b/qapi/trace-events
index cccafc07e5..753433856c 100644
--- a/qapi/trace-events
+++ b/qapi/trace-events
@@ -36,3 +36,5 @@ visit_type_str(void *v, const char *name, char **obj) "v=%p
name=%s obj=%p"
visit_type_number(void *v, const char *name, void *obj) "v=%p name=%s obj=%p"
visit_type_any(void *v, const char *name, void *obj) "v=%p name=%s obj=%p"
visit_type_null(void *v, const char *name, void *obj) "v=%p name=%s obj=%p"
+
+qmp(const char *what, const char *json) "%s %s"
--
2.29.2