Commit 77e2b172 authored by Lluís Vilanova's avatar Lluís Vilanova Committed by Stefan Hajnoczi
Browse files

trace: Add QAPI/QMP interfaces to query and control per-vCPU tracing state 



Signed-off-by: default avatarLluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent bd71211d

hmp-commands-info.hx

+3 −3
Original line number Diff line number Diff line
@@ -646,10 +646,10 @@ ETEXI 


    {

        .name       = "trace-events",

        .args_type  = "name:s?",

        .params     = "[name]",

        .args_type  = "name:s?,vcpu:i?",

        .params     = "[name] [vcpu]",

        .help       = "show available trace-events & their state "

                      "(name: event name pattern)",

                      "(name: event name pattern; vcpu: vCPU to query, default is any)",

        .mhandler.cmd = hmp_info_trace_events,

        .command_completion = info_trace_events_completion,

    },

hmp-commands.hx

+4 −3
Original line number Diff line number Diff line
@@ -281,9 +281,10 @@ ETEXI 


    {

        .name       = "trace-event",

        .args_type  = "name:s,option:b",

        .params     = "name on|off",

        .help       = "changes status of a specific trace event",

        .args_type  = "name:s,option:b,vcpu:i?",

        .params     = "name on|off [vcpu]",

        .help       = "changes status of a specific trace event "

                      "(vcpu: vCPU to set, default is all)",

        .mhandler.cmd = hmp_trace_event,

        .command_completion = trace_event_completion,

    },

monitor.c

+15 −2
Original line number Diff line number Diff line
@@ -904,9 +904,16 @@ static void hmp_trace_event(Monitor *mon, const QDict *qdict) 
{

    const char *tp_name = qdict_get_str(qdict, "name");

    bool new_state = qdict_get_bool(qdict, "option");

    bool has_vcpu = qdict_haskey(qdict, "vcpu");

    int vcpu = qdict_get_try_int(qdict, "vcpu", 0);

    Error *local_err = NULL;



    qmp_trace_event_set_state(tp_name, new_state, true, true, &local_err);

    if (vcpu < 0) {

        monitor_printf(mon, "argument vcpu must be positive");

        return;

    }



    qmp_trace_event_set_state(tp_name, new_state, true, true, has_vcpu, vcpu, &local_err);

    if (local_err) {

        error_report_err(local_err);

    }
@@ -1066,6 +1073,8 @@ static void hmp_info_cpustats(Monitor *mon, const QDict *qdict) 
static void hmp_info_trace_events(Monitor *mon, const QDict *qdict)

{

    const char *name = qdict_get_try_str(qdict, "name");

    bool has_vcpu = qdict_haskey(qdict, "vcpu");

    int vcpu = qdict_get_try_int(qdict, "vcpu", 0);

    TraceEventInfoList *events;

    TraceEventInfoList *elem;

    Error *local_err = NULL;
@@ -1073,8 +1082,12 @@ static void hmp_info_trace_events(Monitor *mon, const QDict *qdict) 
    if (name == NULL) {

        name = "*";

    }

    if (vcpu < 0) {

        monitor_printf(mon, "argument vcpu must be positive");

        return;

    }



    events = qmp_trace_event_get_state(name, &local_err);

    events = qmp_trace_event_get_state(name, has_vcpu, vcpu, &local_err);

    if (local_err) {

        error_report_err(local_err);

        return;

qapi/trace.json

+29 −4
Original line number Diff line number Diff line 
# -*- mode: python -*-

#

# Copyright (C) 2011-2014 Lluís Vilanova <vilanova@ac.upc.edu>

# Copyright (C) 2011-2016 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.
@@ -29,11 +29,15 @@ 
#

# @name: Event name.

# @state: Tracing state.

# @vcpu: Whether this is a per-vCPU event (since 2.7).

#

# An event is per-vCPU if it has the "vcpu" property in the "trace-events"

# files.

#

# Since 2.2

##

{ 'struct': 'TraceEventInfo',

  'data': {'name': 'str', 'state': 'TraceEventState'} }

  'data': {'name': 'str', 'state': 'TraceEventState', 'vcpu': 'bool'} }



##

# @trace-event-get-state:
@@ -41,13 +45,23 @@ 
# Query the state of events.

#

# @name: Event name pattern (case-sensitive glob).

# @vcpu: #optional The vCPU to query (any by default; since 2.7).

#

# Returns: a list of @TraceEventInfo for the matching events

#

# An event is returned if:

# - its name matches the @name pattern, and

# - if @vcpu is given, the event has the "vcpu" property.

#

# Therefore, if @vcpu is given, the operation will only match per-vCPU events,

# returning their state on the specified vCPU. Special case: if @name is an

# exact match, @vcpu is given and the event does not have the "vcpu" property,

# an error is returned.

#

# Since 2.2

##

{ 'command': 'trace-event-get-state',

  'data': {'name': 'str'},

  'data': {'name': 'str', '*vcpu': 'int'},

  'returns': ['TraceEventInfo'] }



##
@@ -58,8 +72,19 @@ 
# @name: Event name pattern (case-sensitive glob).

# @enable: Whether to enable tracing.

# @ignore-unavailable: #optional Do not match unavailable events with @name.

# @vcpu: #optional The vCPU to act upon (all by default; since 2.7).

#

# An event's state is modified if:

# - its name matches the @name pattern, and

# - if @vcpu is given, the event has the "vcpu" property.

#

# Therefore, if @vcpu is given, the operation will only match per-vCPU events,

# setting their state on the specified vCPU. Special case: if @name is an exact

# match, @vcpu is given and the event does not have the "vcpu" property, an

# error is returned.

#

# Since 2.2

##

{ 'command': 'trace-event-set-state',

  'data': {'name': 'str', 'enable': 'bool', '*ignore-unavailable': 'bool'} }
 
  'data': {'name': 'str', 'enable': 'bool', '*ignore-unavailable': 'bool',

           '*vcpu': 'int'} }

qmp-commands.hx

+33 −2
Original line number Diff line number Diff line
@@ -4715,7 +4715,7 @@ EQMP 


    {

        .name       = "trace-event-get-state",

        .args_type  = "name:s",

        .args_type  = "name:s,vcpu:i?",

        .mhandler.cmd_new = qmp_marshal_trace_event_get_state,

    },
@@ -4725,6 +4725,20 @@ trace-event-get-state 


Query the state of events.



Arguments:



- "name": Event name pattern (json-string).

- "vcpu": The vCPU to query, any vCPU by default (json-int, optional).



An event is returned if:

- its name matches the "name" pattern, and

- if "vcpu" is given, the event has the "vcpu" property.



Therefore, if "vcpu" is given, the operation will only match per-vCPU events,

returning their state on the specified vCPU. Special case: if "name" is an exact

match, "vcpu" is given and the event does not have the "vcpu" property, an error

is returned.



Example:



-> { "execute": "trace-event-get-state", "arguments": { "name": "qemu_memalign" } }
@@ -4733,7 +4747,7 @@ EQMP 


    {

        .name       = "trace-event-set-state",

        .args_type  = "name:s,enable:b,ignore-unavailable:b?",

        .args_type  = "name:s,enable:b,ignore-unavailable:b?,vcpu:i?",

        .mhandler.cmd_new = qmp_marshal_trace_event_set_state,

    },
@@ -4743,6 +4757,23 @@ trace-event-set-state 


Set the state of events.



Arguments:



- "name": Event name pattern (json-string).

- "enable": Whether to enable or disable the event (json-bool).

- "ignore-unavailable": Whether to ignore errors for events that cannot be

  changed (json-bool, optional).

- "vcpu": The vCPU to act upon, all vCPUs by default (json-int, optional).



An event's state is modified if:

- its name matches the "name" pattern, and

- if "vcpu" is given, the event has the "vcpu" property.



Therefore, if "vcpu" is given, the operation will only match per-vCPU events,

setting their state on the specified vCPU. Special case: if "name" is an exact

match, "vcpu" is given and the event does not have the "vcpu" property, an error

is returned.



Example:



-> { "execute": "trace-event-set-state", "arguments": { "name": "qemu_memalign", "enable": "true" } }