Commit 1dde0f48 authored by Lluís Vilanova's avatar Lluís Vilanova Committed by Stefan Hajnoczi
Browse files

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



Signed-off-by: default avatarLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 20140825111957.31112.31733.stgit@fimbulvetr.bsc.es
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 60e17d28

qapi-schema.json

+3 −0
Original line number Diff line number Diff line
@@ -11,6 +11,9 @@ 
# QAPI event definitions

{ 'include': 'qapi/event.json' }



# Tracing commands

{ 'include': 'qapi/trace.json' }



##

# LostTickPolicy:

#

qapi/trace.json

0 → 100644
+65 −0
Original line number Diff line number Diff line 
# -*- 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'} }

qmp-commands.hx

+35 −0
Original line number Diff line number Diff line
@@ -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

trace/Makefile.objs

+1 −0
Original line number Diff line number Diff line
@@ -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

trace/qmp.c

0 → 100644
+75 −0
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/*

 * 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);

        }

    }

}