trace: [qmp] Add commands to query and control event tracing state

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 20140825111957.31112.31733.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Lluís Vilanova 2014-08-25 13:19:57 +02:00 committed by Stefan Hajnoczi
parent 60e17d2822
commit 1dde0f48d5
5 changed files with 180 additions and 1 deletions

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@ -11,6 +11,9 @@
# QAPI event definitions
{ 'include': 'qapi/event.json' }
# Tracing commands
{ 'include': 'qapi/trace.json' }
##
# LostTickPolicy:
#

65
qapi/trace.json Normal file
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@ -0,0 +1,65 @@
# -*- mode: python -*-
#
# Copyright (C) 2011-2014 Lluís Vilanova <vilanova@ac.upc.edu>
#
# This work is licensed under the terms of the GNU GPL, version 2 or later.
# See the COPYING file in the top-level directory.
##
# @TraceEventState:
#
# State of a tracing event.
#
# @unavailable: The event is statically disabled.
#
# @disabled: The event is dynamically disabled.
#
# @enabled: The event is dynamically enabled.
#
# Since 2.2
##
{ 'enum': 'TraceEventState',
'data': ['unavailable', 'disabled', 'enabled'] }
##
# @TraceEventInfo:
#
# Information of a tracing event.
#
# @name: Event name.
# @state: Tracing state.
#
# Since 2.2
##
{ 'type': 'TraceEventInfo',
'data': {'name': 'str', 'state': 'TraceEventState'} }
##
# @trace-event-get-state:
#
# Query the state of events.
#
# @name: Event name pattern (case-sensitive glob).
#
# Returns: a list of @TraceEventInfo for the matching events
#
# Since 2.2
##
{ 'command': 'trace-event-get-state',
'data': {'name': 'str'},
'returns': ['TraceEventInfo'] }
##
# @trace-event-set-state:
#
# Set the dynamic tracing state of events.
#
# @name: Event name pattern (case-sensitive glob).
# @enable: Whether to enable tracing.
# @ignore-unavailable: #optional Do not match unavailable events with @name.
#
# Since 2.2
##
{ 'command': 'trace-event-set-state',
'data': {'name': 'str', 'enable': 'bool', '*ignore-unavailable': 'bool'} }

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@ -3752,5 +3752,40 @@ Example:
-> { "execute": "rtc-reset-reinjection" }
<- { "return": {} }
EQMP
{
.name = "trace-event-get-state",
.args_type = "name:s",
.mhandler.cmd_new = qmp_marshal_input_trace_event_get_state,
},
SQMP
trace-event-get-state
---------------------
Query the state of events.
Example:
-> { "execute": "trace-event-get-state", "arguments": { "name": "qemu_memalign" } }
<- { "return": [ { "name": "qemu_memalign", "state": "disabled" } ] }
EQMP
{
.name = "trace-event-set-state",
.args_type = "name:s,enable:b,ignore-unavailable:b?",
.mhandler.cmd_new = qmp_marshal_input_trace_event_set_state,
},
SQMP
trace-event-set-state
---------------------
Set the state of events.
Example:
-> { "execute": "trace-event-set-state", "arguments": { "name": "qemu_memalign", "enable": "true" } }
<- { "return": {} }
EQMP

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@ -144,3 +144,4 @@ util-obj-$(CONFIG_TRACE_SIMPLE) += simple.o generated-tracers.o
util-obj-$(CONFIG_TRACE_FTRACE) += ftrace.o
util-obj-$(CONFIG_TRACE_UST) += generated-ust.o
util-obj-y += control.o
util-obj-y += qmp.o

75
trace/qmp.c Normal file
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@ -0,0 +1,75 @@
/*
* QMP commands for tracing events.
*
* Copyright (C) 2014 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/typedefs.h"
#include "qmp-commands.h"
#include "trace/control.h"
TraceEventInfoList *qmp_trace_event_get_state(const char *name, Error **errp)
{
TraceEventInfoList *events = NULL;
bool found = false;
TraceEvent *ev;
ev = NULL;
while ((ev = trace_event_pattern(name, ev)) != NULL) {
TraceEventInfoList *elem = g_new(TraceEventInfoList, 1);
elem->value = g_new(TraceEventInfo, 1);
elem->value->name = g_strdup(trace_event_get_name(ev));
if (!trace_event_get_state_static(ev)) {
elem->value->state = TRACE_EVENT_STATE_UNAVAILABLE;
} else if (!trace_event_get_state_dynamic(ev)) {
elem->value->state = TRACE_EVENT_STATE_DISABLED;
} else {
elem->value->state = TRACE_EVENT_STATE_ENABLED;
}
elem->next = events;
events = elem;
found = true;
}
if (!found && !trace_event_is_pattern(name)) {
error_setg(errp, "unknown event \"%s\"", name);
}
return events;
}
void qmp_trace_event_set_state(const char *name, bool enable,
bool has_ignore_unavailable,
bool ignore_unavailable, Error **errp)
{
bool found = false;
TraceEvent *ev;
/* Check all selected events are dynamic */
ev = NULL;
while ((ev = trace_event_pattern(name, ev)) != NULL) {
found = true;
if (!(has_ignore_unavailable && ignore_unavailable) &&
!trace_event_get_state_static(ev)) {
error_setg(errp, "cannot set dynamic tracing state for \"%s\"",
trace_event_get_name(ev));
return;
}
}
if (!found && !trace_event_is_pattern(name)) {
error_setg(errp, "unknown event \"%s\"", name);
return;
}
/* Apply changes */
ev = NULL;
while ((ev = trace_event_pattern(name, ev)) != NULL) {
if (trace_event_get_state_static(ev)) {
trace_event_set_state_dynamic(ev, enable);
}
}
}