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monitor: Split out monitor/qmp.c 

Move QMP infrastructure from monitor/misc.c to monitor/qmp.c. This is
code that can be shared for all targets, so compile it only once.

The amount of function and particularly extern variables in
monitor_int.h is probably a bit larger than it needs to be, but this way
no non-trivial code modifications are needed. The interfaces between QMP
and the monitor core can be cleaned up later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190613153405.24769-11-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[monitor_is_qmp() tidied up to make checkpatch.pl happy,
superfluous #include dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This commit is contained in:
Kevin Wolf 2019-06-13 17:34:00 +02:00 committed by Markus Armbruster
parent 5bce308aaa
commit 7e3c0deab1
6 changed files with 450 additions and 393 deletions
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1
Makefile.objs
View File

@ -46,6 +46,7 @@ ifeq ($(CONFIG_SOFTMMU),y)
common-obj-y = blockdev.o blockdev-nbd.o block/
common-obj-y += bootdevice.o iothread.o
common-obj-y += job-qmp.o
common-obj-y += monitor/
common-obj-y += net/
common-obj-y += qdev-monitor.o device-hotplug.o
common-obj-$(CONFIG_WIN32) += os-win32.o

1
monitor/Makefile.objs
View File

@ -1,2 +1,3 @@
obj-y += misc.o
common-obj-y += qmp.o
common-obj-y += qmp-cmds.o hmp-cmds.o

401
monitor/misc.c
View File

@ -36,7 +36,6 @@
#include "exec/gdbstub.h"
#include "net/net.h"
#include "net/slirp.h"
#include "chardev/char-io.h"
#include "chardev/char-mux.h"
#include "ui/qemu-spice.h"
#include "sysemu/numa.h"
@ -58,8 +57,6 @@
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/qnum.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qjson.h"
#include "qapi/qmp/qlist.h"
#include "qom/object_interfaces.h"
#include "trace.h"
#include "trace/control.h"
@ -81,7 +78,6 @@
#include "qapi/qapi-introspect.h"
#include "sysemu/qtest.h"
#include "sysemu/cpus.h"
#include "sysemu/iothread.h"
#include "qemu/cutils.h"
#include "tcg/tcg.h"
@ -138,51 +134,29 @@ IOThread *mon_iothread;
/* Bottom half to dispatch the requests received from I/O thread */
QEMUBH *qmp_dispatcher_bh;
struct QMPRequest {
/* Owner of the request */
MonitorQMP *mon;
/*
* Request object to be handled or Error to be reported
* (exactly one of them is non-null)
*/
QObject *req;
Error *err;
};
typedef struct QMPRequest QMPRequest;
/* QMP checker flags */
#define QMP_ACCEPT_UNKNOWNS 1
/* Protects mon_list, monitor_qapi_event_state, monitor_destroyed. */
static QemuMutex monitor_lock;
QemuMutex monitor_lock;
static GHashTable *monitor_qapi_event_state;
static QTAILQ_HEAD(, Monitor) mon_list;
MonitorList mon_list;
static bool monitor_destroyed;
/* Protects mon_fdsets */
static QemuMutex mon_fdsets_lock;
static QLIST_HEAD(, MonFdset) mon_fdsets;
static int mon_refcount;
int mon_refcount;
static HMPCommand hmp_cmds[];
static HMPCommand hmp_info_cmds[];
QmpCommandList qmp_commands, qmp_cap_negotiation_commands;
__thread Monitor *cur_mon;
static void monitor_command_cb(void *opaque, const char *cmdline,
void *readline_opaque);
/**
* Is @mon a QMP monitor?
*/
static inline bool monitor_is_qmp(const Monitor *mon)
{
return (mon->flags & MONITOR_USE_CONTROL);
}
/**
* Is @mon is using readline?
* Note: not all HMP monitors use readline, e.g., gdbserver has a
@ -241,28 +215,6 @@ int monitor_read_password(MonitorHMP *mon, ReadLineFunc *readline_func,
}
}
static void qmp_request_free(QMPRequest *req)
{
qobject_unref(req->req);
error_free(req->err);
g_free(req);
}
/* Caller must hold mon->qmp.qmp_queue_lock */
static void monitor_qmp_cleanup_req_queue_locked(MonitorQMP *mon)
{
while (!g_queue_is_empty(mon->qmp_requests)) {
qmp_request_free(g_queue_pop_head(mon->qmp_requests));
}
}
static void monitor_qmp_cleanup_queues(MonitorQMP *mon)
{
qemu_mutex_lock(&mon->qmp_queue_lock);
monitor_qmp_cleanup_req_queue_locked(mon);
qemu_mutex_unlock(&mon->qmp_queue_lock);
}
static void monitor_flush_locked(Monitor *mon);
@ -322,7 +274,7 @@ void monitor_flush(Monitor *mon)
}
/* flush at every end of line */
static int monitor_puts(Monitor *mon, const char *str)
int monitor_puts(Monitor *mon, const char *str)
{
int i;
char c;
@ -372,21 +324,6 @@ int monitor_printf(Monitor *mon, const char *fmt, ...)
return ret;
}
static void qmp_send_response(MonitorQMP *mon, const QDict *rsp)
{
const QObject *data = QOBJECT(rsp);
QString *json;
json = mon->common.flags & MONITOR_USE_PRETTY ?
qobject_to_json_pretty(data) : qobject_to_json(data);
assert(json != NULL);
qstring_append_chr(json, '\n');
monitor_puts(&mon->common, qstring_get_str(json));
qobject_unref(json);
}
static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT__MAX] = {
/* Limit guest-triggerable events to 1 per second */
[QAPI_EVENT_RTC_CHANGE] = { 1000 * SCALE_MS },
@ -601,8 +538,8 @@ static void handle_hmp_command(MonitorHMP *mon, const char *cmdline);
static void monitor_iothread_init(void);
static void monitor_data_init(Monitor *mon, int flags, bool skip_flush,
bool use_io_thread)
void monitor_data_init(Monitor *mon, int flags, bool skip_flush,
bool use_io_thread)
{
if (use_io_thread && !mon_iothread) {
monitor_iothread_init();
@ -614,14 +551,6 @@ static void monitor_data_init(Monitor *mon, int flags, bool skip_flush,
mon->flags = flags;
}
static void monitor_data_destroy_qmp(MonitorQMP *mon)
{
json_message_parser_destroy(&mon->parser);
qemu_mutex_destroy(&mon->qmp_queue_lock);
monitor_qmp_cleanup_req_queue_locked(mon);
g_queue_free(mon->qmp_requests);
}
static void monitor_data_destroy(Monitor *mon)
{
g_free(mon->mon_cpu_path);
@ -1058,18 +987,6 @@ static void monitor_init_qmp_commands(void)
qmp_marshal_qmp_capabilities, QCO_ALLOW_PRECONFIG);
}
static bool qmp_oob_enabled(MonitorQMP *mon)
{
return mon->capab[QMP_CAPABILITY_OOB];
}
static void monitor_qmp_caps_reset(MonitorQMP *mon)
{
memset(mon->capab_offered, 0, sizeof(mon->capab_offered));
memset(mon->capab, 0, sizeof(mon->capab));
mon->capab_offered[QMP_CAPABILITY_OOB] = mon->common.use_io_thread;
}
/*
* Accept QMP capabilities in @list for @mon.
* On success, set mon->qmp.capab[], and return true.
@ -2245,7 +2162,7 @@ static void monitor_fdset_cleanup(MonFdset *mon_fdset)
}
}
static void monitor_fdsets_cleanup(void)
void monitor_fdsets_cleanup(void)
{
MonFdset *mon_fdset;
MonFdset *mon_fdset_next;
@ -4023,209 +3940,13 @@ cleanup:
free_cmdline_args(args, nb_args);
}
static int monitor_can_read(void *opaque)
int monitor_can_read(void *opaque)
{
Monitor *mon = opaque;
return !atomic_mb_read(&mon->suspend_cnt);
}
/*
* Emit QMP response @rsp with ID @id to @mon.
* Null @rsp can only happen for commands with QCO_NO_SUCCESS_RESP.
* Nothing is emitted then.
*/
static void monitor_qmp_respond(MonitorQMP *mon, QDict *rsp)
{
if (rsp) {
qmp_send_response(mon, rsp);
}
}
static void monitor_qmp_dispatch(MonitorQMP *mon, QObject *req)
{
Monitor *old_mon;
QDict *rsp;
QDict *error;
old_mon = cur_mon;
cur_mon = &mon->common;
rsp = qmp_dispatch(mon->commands, req, qmp_oob_enabled(mon));
cur_mon = old_mon;
if (mon->commands == &qmp_cap_negotiation_commands) {
error = qdict_get_qdict(rsp, "error");
if (error
&& !g_strcmp0(qdict_get_try_str(error, "class"),
QapiErrorClass_str(ERROR_CLASS_COMMAND_NOT_FOUND))) {
/* Provide a more useful error message */
qdict_del(error, "desc");
qdict_put_str(error, "desc", "Expecting capabilities negotiation"
" with 'qmp_capabilities'");
}
}
monitor_qmp_respond(mon, rsp);
qobject_unref(rsp);
}
/*
* Pop a QMP request from a monitor request queue.
* Return the request, or NULL all request queues are empty.
* We are using round-robin fashion to pop the request, to avoid
* processing commands only on a very busy monitor. To achieve that,
* when we process one request on a specific monitor, we put that
* monitor to the end of mon_list queue.
*
* Note: if the function returned with non-NULL, then the caller will
* be with qmp_mon->qmp_queue_lock held, and the caller is responsible
* to release it.
*/
static QMPRequest *monitor_qmp_requests_pop_any_with_lock(void)
{
QMPRequest *req_obj = NULL;
Monitor *mon;
MonitorQMP *qmp_mon;
qemu_mutex_lock(&monitor_lock);
QTAILQ_FOREACH(mon, &mon_list, entry) {
if (!monitor_is_qmp(mon)) {
continue;
}
qmp_mon = container_of(mon, MonitorQMP, common);
qemu_mutex_lock(&qmp_mon->qmp_queue_lock);
req_obj = g_queue_pop_head(qmp_mon->qmp_requests);
if (req_obj) {
/* With the lock of corresponding queue held */
break;
}
qemu_mutex_unlock(&qmp_mon->qmp_queue_lock);
}
if (req_obj) {
/*
* We found one request on the monitor. Degrade this monitor's
* priority to lowest by re-inserting it to end of queue.
*/
QTAILQ_REMOVE(&mon_list, mon, entry);
QTAILQ_INSERT_TAIL(&mon_list, mon, entry);
}
qemu_mutex_unlock(&monitor_lock);
return req_obj;
}
static void monitor_qmp_bh_dispatcher(void *data)
{
QMPRequest *req_obj = monitor_qmp_requests_pop_any_with_lock();
QDict *rsp;
bool need_resume;
MonitorQMP *mon;
if (!req_obj) {
return;
}
mon = req_obj->mon;
/* qmp_oob_enabled() might change after "qmp_capabilities" */
need_resume = !qmp_oob_enabled(mon) ||
mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1;
qemu_mutex_unlock(&mon->qmp_queue_lock);
if (req_obj->req) {
QDict *qdict = qobject_to(QDict, req_obj->req);
QObject *id = qdict ? qdict_get(qdict, "id") : NULL;
trace_monitor_qmp_cmd_in_band(qobject_get_try_str(id) ?: "");
monitor_qmp_dispatch(mon, req_obj->req);
} else {
assert(req_obj->err);
rsp = qmp_error_response(req_obj->err);
req_obj->err = NULL;
monitor_qmp_respond(mon, rsp);
qobject_unref(rsp);
}
if (need_resume) {
/* Pairs with the monitor_suspend() in handle_qmp_command() */
monitor_resume(&mon->common);
}
qmp_request_free(req_obj);
/* Reschedule instead of looping so the main loop stays responsive */
qemu_bh_schedule(qmp_dispatcher_bh);
}
static void handle_qmp_command(void *opaque, QObject *req, Error *err)
{
MonitorQMP *mon = opaque;
QObject *id = NULL;
QDict *qdict;
QMPRequest *req_obj;
assert(!req != !err);
qdict = qobject_to(QDict, req);
if (qdict) {
id = qdict_get(qdict, "id");
} /* else will fail qmp_dispatch() */
if (req && trace_event_get_state_backends(TRACE_HANDLE_QMP_COMMAND)) {
QString *req_json = qobject_to_json(req);
trace_handle_qmp_command(mon, qstring_get_str(req_json));
qobject_unref(req_json);
}
if (qdict && qmp_is_oob(qdict)) {
/* OOB commands are executed immediately */
trace_monitor_qmp_cmd_out_of_band(qobject_get_try_str(id) ?: "");
monitor_qmp_dispatch(mon, req);
qobject_unref(req);
return;
}
req_obj = g_new0(QMPRequest, 1);
req_obj->mon = mon;
req_obj->req = req;
req_obj->err = err;
/* Protect qmp_requests and fetching its length. */
qemu_mutex_lock(&mon->qmp_queue_lock);
/*
* Suspend the monitor when we can't queue more requests after
* this one. Dequeuing in monitor_qmp_bh_dispatcher() will resume
* it. Note that when OOB is disabled, we queue at most one
* command, for backward compatibility.
*/
if (!qmp_oob_enabled(mon) ||
mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1) {
monitor_suspend(&mon->common);
}
/*
* Put the request to the end of queue so that requests will be
* handled in time order. Ownership for req_obj, req,
* etc. will be delivered to the handler side.
*/
assert(mon->qmp_requests->length < QMP_REQ_QUEUE_LEN_MAX);
g_queue_push_tail(mon->qmp_requests, req_obj);
qemu_mutex_unlock(&mon->qmp_queue_lock);
/* Kick the dispatcher routine */
qemu_bh_schedule(qmp_dispatcher_bh);
}
static void monitor_qmp_read(void *opaque, const uint8_t *buf, int size)
{
MonitorQMP *mon = opaque;
json_message_parser_feed(&mon->parser, (const char *) buf, size);
}
static void monitor_read(void *opaque, const uint8_t *buf, int size)
{
MonitorHMP *mon;
@ -4312,56 +4033,6 @@ void monitor_resume(Monitor *mon)
trace_monitor_suspend(mon, -1);
}
static QDict *qmp_greeting(MonitorQMP *mon)
{
QList *cap_list = qlist_new();
QObject *ver = NULL;
QMPCapability cap;
qmp_marshal_query_version(NULL, &ver, NULL);
for (cap = 0; cap < QMP_CAPABILITY__MAX; cap++) {
if (mon->capab_offered[cap]) {
qlist_append_str(cap_list, QMPCapability_str(cap));
}
}
return qdict_from_jsonf_nofail(
"{'QMP': {'version': %p, 'capabilities': %p}}",
ver, cap_list);
}
static void monitor_qmp_event(void *opaque, int event)
{
QDict *data;
MonitorQMP *mon = opaque;
switch (event) {
case CHR_EVENT_OPENED:
mon->commands = &qmp_cap_negotiation_commands;
monitor_qmp_caps_reset(mon);
data = qmp_greeting(mon);
qmp_send_response(mon, data);
qobject_unref(data);
mon_refcount++;
break;
case CHR_EVENT_CLOSED:
/*
* Note: this is only useful when the output of the chardev
* backend is still open. For example, when the backend is
* stdio, it's possible that stdout is still open when stdin
* is closed.
*/
monitor_qmp_cleanup_queues(mon);
json_message_parser_destroy(&mon->parser);
json_message_parser_init(&mon->parser, handle_qmp_command,
mon, NULL);
mon_refcount--;
monitor_fdsets_cleanup();
break;
}
}
static void monitor_event(void *opaque, int event)
{
Monitor *mon = opaque;
@ -4495,7 +4166,7 @@ int error_vprintf_unless_qmp(const char *fmt, va_list ap)
return -1;
}
static void monitor_list_append(Monitor *mon)
void monitor_list_append(Monitor *mon)
{
qemu_mutex_lock(&monitor_lock);
/*
@ -4515,60 +4186,6 @@ static void monitor_list_append(Monitor *mon)
}
}
static void monitor_qmp_setup_handlers_bh(void *opaque)
{
MonitorQMP *mon = opaque;
GMainContext *context;
assert(mon->common.use_io_thread);
context = iothread_get_g_main_context(mon_iothread);
assert(context);
qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
monitor_qmp_read, monitor_qmp_event,
NULL, &mon->common, context, true);
monitor_list_append(&mon->common);
}
static void monitor_init_qmp(Chardev *chr, int flags)
{
MonitorQMP *mon = g_new0(MonitorQMP, 1);
/* Only HMP supports readline */
assert(!(flags & MONITOR_USE_READLINE));
/* Note: we run QMP monitor in I/O thread when @chr supports that */
monitor_data_init(&mon->common, flags, false,
qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT));
qemu_mutex_init(&mon->qmp_queue_lock);
mon->qmp_requests = g_queue_new();
qemu_chr_fe_init(&mon->common.chr, chr, &error_abort);
qemu_chr_fe_set_echo(&mon->common.chr, true);
json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL);
if (mon->common.use_io_thread) {
/*
* Make sure the old iowatch is gone. It's possible when
* e.g. the chardev is in client mode, with wait=on.
*/
remove_fd_in_watch(chr);
/*
* We can't call qemu_chr_fe_set_handlers() directly here
* since chardev might be running in the monitor I/O
* thread. Schedule a bottom half.
*/
aio_bh_schedule_oneshot(iothread_get_aio_context(mon_iothread),
monitor_qmp_setup_handlers_bh, mon);
/* The bottom half will add @mon to @mon_list */
} else {
qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
monitor_qmp_read, monitor_qmp_event,
NULL, &mon->common, NULL, true);
monitor_list_append(&mon->common);
}
}
static void monitor_init_hmp(Chardev *chr, int flags)
{
MonitorHMP *mon = g_new0(MonitorHMP, 1);

30
monitor/monitor-internal.h
View File

@ -31,6 +31,7 @@
#include "qapi/qmp/dispatch.h"
#include "qapi/qmp/json-parser.h"
#include "qemu/readline.h"
#include "sysemu/iothread.h"
/*
* Supported types:
@ -142,4 +143,33 @@ typedef struct {
GQueue *qmp_requests;
} MonitorQMP;
/**
* Is @mon a QMP monitor?
*/
static inline bool monitor_is_qmp(const Monitor *mon)
{
return mon->flags & MONITOR_USE_CONTROL;
}
typedef QTAILQ_HEAD(MonitorList, Monitor) MonitorList;
extern IOThread *mon_iothread;
extern QEMUBH *qmp_dispatcher_bh;
extern QmpCommandList qmp_commands, qmp_cap_negotiation_commands;
extern QemuMutex monitor_lock;
extern MonitorList mon_list;
extern int mon_refcount;
void monitor_init_qmp(Chardev *chr, int flags);
int monitor_puts(Monitor *mon, const char *str);
void monitor_data_init(Monitor *mon, int flags, bool skip_flush,
bool use_io_thread);
int monitor_can_read(void *opaque);
void monitor_list_append(Monitor *mon);
void monitor_fdsets_cleanup(void);
void qmp_send_response(MonitorQMP *mon, const QDict *rsp);
void monitor_data_destroy_qmp(MonitorQMP *mon);
void monitor_qmp_bh_dispatcher(void *data);
#endif

406
monitor/qmp.c Normal file
View File

@ -0,0 +1,406 @@
/*
* QEMU monitor
*
* Copyright (c) 2003-2004 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "chardev/char-io.h"
#include "monitor-internal.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-misc.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qjson.h"
#include "qapi/qmp/qlist.h"
#include "qapi/qmp/qstring.h"
#include "trace.h"
struct QMPRequest {
/* Owner of the request */
MonitorQMP *mon;
/*
* Request object to be handled or Error to be reported
* (exactly one of them is non-null)
*/
QObject *req;
Error *err;
};
typedef struct QMPRequest QMPRequest;
QmpCommandList qmp_commands, qmp_cap_negotiation_commands;
static bool qmp_oob_enabled(MonitorQMP *mon)
{
return mon->capab[QMP_CAPABILITY_OOB];
}
static void monitor_qmp_caps_reset(MonitorQMP *mon)
{
memset(mon->capab_offered, 0, sizeof(mon->capab_offered));
memset(mon->capab, 0, sizeof(mon->capab));
mon->capab_offered[QMP_CAPABILITY_OOB] = mon->common.use_io_thread;
}
static void qmp_request_free(QMPRequest *req)
{
qobject_unref(req->req);
error_free(req->err);
g_free(req);
}
/* Caller must hold mon->qmp.qmp_queue_lock */
static void monitor_qmp_cleanup_req_queue_locked(MonitorQMP *mon)
{
while (!g_queue_is_empty(mon->qmp_requests)) {
qmp_request_free(g_queue_pop_head(mon->qmp_requests));
}
}
static void monitor_qmp_cleanup_queues(MonitorQMP *mon)
{
qemu_mutex_lock(&mon->qmp_queue_lock);
monitor_qmp_cleanup_req_queue_locked(mon);
qemu_mutex_unlock(&mon->qmp_queue_lock);
}
void qmp_send_response(MonitorQMP *mon, const QDict *rsp)
{
const QObject *data = QOBJECT(rsp);
QString *json;
json = mon->common.flags & MONITOR_USE_PRETTY ?
qobject_to_json_pretty(data) : qobject_to_json(data);
assert(json != NULL);
qstring_append_chr(json, '\n');
monitor_puts(&mon->common, qstring_get_str(json));
qobject_unref(json);
}
/*
* Emit QMP response @rsp with ID @id to @mon.
* Null @rsp can only happen for commands with QCO_NO_SUCCESS_RESP.
* Nothing is emitted then.
*/
static void monitor_qmp_respond(MonitorQMP *mon, QDict *rsp)
{
if (rsp) {
qmp_send_response(mon, rsp);
}
}
static void monitor_qmp_dispatch(MonitorQMP *mon, QObject *req)
{
Monitor *old_mon;
QDict *rsp;
QDict *error;
old_mon = cur_mon;
cur_mon = &mon->common;
rsp = qmp_dispatch(mon->commands, req, qmp_oob_enabled(mon));
cur_mon = old_mon;
if (mon->commands == &qmp_cap_negotiation_commands) {
error = qdict_get_qdict(rsp, "error");
if (error
&& !g_strcmp0(qdict_get_try_str(error, "class"),
QapiErrorClass_str(ERROR_CLASS_COMMAND_NOT_FOUND))) {
/* Provide a more useful error message */
qdict_del(error, "desc");
qdict_put_str(error, "desc", "Expecting capabilities negotiation"
" with 'qmp_capabilities'");
}
}
monitor_qmp_respond(mon, rsp);
qobject_unref(rsp);
}
/*
* Pop a QMP request from a monitor request queue.
* Return the request, or NULL all request queues are empty.
* We are using round-robin fashion to pop the request, to avoid
* processing commands only on a very busy monitor. To achieve that,
* when we process one request on a specific monitor, we put that
* monitor to the end of mon_list queue.
*
* Note: if the function returned with non-NULL, then the caller will
* be with qmp_mon->qmp_queue_lock held, and the caller is responsible
* to release it.
*/
static QMPRequest *monitor_qmp_requests_pop_any_with_lock(void)
{
QMPRequest *req_obj = NULL;
Monitor *mon;
MonitorQMP *qmp_mon;
qemu_mutex_lock(&monitor_lock);
QTAILQ_FOREACH(mon, &mon_list, entry) {
if (!monitor_is_qmp(mon)) {
continue;
}
qmp_mon = container_of(mon, MonitorQMP, common);
qemu_mutex_lock(&qmp_mon->qmp_queue_lock);
req_obj = g_queue_pop_head(qmp_mon->qmp_requests);
if (req_obj) {
/* With the lock of corresponding queue held */
break;
}
qemu_mutex_unlock(&qmp_mon->qmp_queue_lock);
}
if (req_obj) {
/*
* We found one request on the monitor. Degrade this monitor's
* priority to lowest by re-inserting it to end of queue.
*/
QTAILQ_REMOVE(&mon_list, mon, entry);
QTAILQ_INSERT_TAIL(&mon_list, mon, entry);
}
qemu_mutex_unlock(&monitor_lock);
return req_obj;
}
void monitor_qmp_bh_dispatcher(void *data)
{
QMPRequest *req_obj = monitor_qmp_requests_pop_any_with_lock();
QDict *rsp;
bool need_resume;
MonitorQMP *mon;
if (!req_obj) {
return;
}
mon = req_obj->mon;
/* qmp_oob_enabled() might change after "qmp_capabilities" */
need_resume = !qmp_oob_enabled(mon) ||
mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1;
qemu_mutex_unlock(&mon->qmp_queue_lock);
if (req_obj->req) {
QDict *qdict = qobject_to(QDict, req_obj->req);
QObject *id = qdict ? qdict_get(qdict, "id") : NULL;
trace_monitor_qmp_cmd_in_band(qobject_get_try_str(id) ?: "");
monitor_qmp_dispatch(mon, req_obj->req);
} else {
assert(req_obj->err);
rsp = qmp_error_response(req_obj->err);
req_obj->err = NULL;
monitor_qmp_respond(mon, rsp);
qobject_unref(rsp);
}
if (need_resume) {
/* Pairs with the monitor_suspend() in handle_qmp_command() */
monitor_resume(&mon->common);
}
qmp_request_free(req_obj);
/* Reschedule instead of looping so the main loop stays responsive */
qemu_bh_schedule(qmp_dispatcher_bh);
}
static void handle_qmp_command(void *opaque, QObject *req, Error *err)
{
MonitorQMP *mon = opaque;
QObject *id = NULL;
QDict *qdict;
QMPRequest *req_obj;
assert(!req != !err);
qdict = qobject_to(QDict, req);
if (qdict) {
id = qdict_get(qdict, "id");
} /* else will fail qmp_dispatch() */
if (req && trace_event_get_state_backends(TRACE_HANDLE_QMP_COMMAND)) {
QString *req_json = qobject_to_json(req);
trace_handle_qmp_command(mon, qstring_get_str(req_json));
qobject_unref(req_json);
}
if (qdict && qmp_is_oob(qdict)) {
/* OOB commands are executed immediately */
trace_monitor_qmp_cmd_out_of_band(qobject_get_try_str(id) ?: "");
monitor_qmp_dispatch(mon, req);
qobject_unref(req);
return;
}
req_obj = g_new0(QMPRequest, 1);
req_obj->mon = mon;
req_obj->req = req;
req_obj->err = err;
/* Protect qmp_requests and fetching its length. */
qemu_mutex_lock(&mon->qmp_queue_lock);
/*
* Suspend the monitor when we can't queue more requests after
* this one. Dequeuing in monitor_qmp_bh_dispatcher() will resume
* it. Note that when OOB is disabled, we queue at most one
* command, for backward compatibility.
*/
if (!qmp_oob_enabled(mon) ||
mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1) {
monitor_suspend(&mon->common);
}
/*
* Put the request to the end of queue so that requests will be
* handled in time order. Ownership for req_obj, req,
* etc. will be delivered to the handler side.
*/
assert(mon->qmp_requests->length < QMP_REQ_QUEUE_LEN_MAX);
g_queue_push_tail(mon->qmp_requests, req_obj);
qemu_mutex_unlock(&mon->qmp_queue_lock);
/* Kick the dispatcher routine */
qemu_bh_schedule(qmp_dispatcher_bh);
}
static void monitor_qmp_read(void *opaque, const uint8_t *buf, int size)
{
MonitorQMP *mon = opaque;
json_message_parser_feed(&mon->parser, (const char *) buf, size);
}
static QDict *qmp_greeting(MonitorQMP *mon)
{
QList *cap_list = qlist_new();
QObject *ver = NULL;
QMPCapability cap;
qmp_marshal_query_version(NULL, &ver, NULL);
for (cap = 0; cap < QMP_CAPABILITY__MAX; cap++) {
if (mon->capab_offered[cap]) {
qlist_append_str(cap_list, QMPCapability_str(cap));
}
}
return qdict_from_jsonf_nofail(
"{'QMP': {'version': %p, 'capabilities': %p}}",
ver, cap_list);
}
static void monitor_qmp_event(void *opaque, int event)
{
QDict *data;
MonitorQMP *mon = opaque;
switch (event) {
case CHR_EVENT_OPENED:
mon->commands = &qmp_cap_negotiation_commands;
monitor_qmp_caps_reset(mon);
data = qmp_greeting(mon);
qmp_send_response(mon, data);
qobject_unref(data);
mon_refcount++;
break;
case CHR_EVENT_CLOSED:
/*
* Note: this is only useful when the output of the chardev
* backend is still open. For example, when the backend is
* stdio, it's possible that stdout is still open when stdin
* is closed.
*/
monitor_qmp_cleanup_queues(mon);
json_message_parser_destroy(&mon->parser);
json_message_parser_init(&mon->parser, handle_qmp_command,
mon, NULL);
mon_refcount--;
monitor_fdsets_cleanup();
break;
}
}
void monitor_data_destroy_qmp(MonitorQMP *mon)
{
json_message_parser_destroy(&mon->parser);
qemu_mutex_destroy(&mon->qmp_queue_lock);
monitor_qmp_cleanup_req_queue_locked(mon);
g_queue_free(mon->qmp_requests);
}
static void monitor_qmp_setup_handlers_bh(void *opaque)
{
MonitorQMP *mon = opaque;
GMainContext *context;
assert(mon->common.use_io_thread);
context = iothread_get_g_main_context(mon_iothread);
assert(context);
qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
monitor_qmp_read, monitor_qmp_event,
NULL, &mon->common, context, true);
monitor_list_append(&mon->common);
}
void monitor_init_qmp(Chardev *chr, int flags)
{
MonitorQMP *mon = g_new0(MonitorQMP, 1);
/* Only HMP supports readline */
assert(!(flags & MONITOR_USE_READLINE));
/* Note: we run QMP monitor in I/O thread when @chr supports that */
monitor_data_init(&mon->common, flags, false,
qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT));
qemu_mutex_init(&mon->qmp_queue_lock);
mon->qmp_requests = g_queue_new();
qemu_chr_fe_init(&mon->common.chr, chr, &error_abort);
qemu_chr_fe_set_echo(&mon->common.chr, true);
json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL);
if (mon->common.use_io_thread) {
/*
* Make sure the old iowatch is gone. It's possible when
* e.g. the chardev is in client mode, with wait=on.
*/
remove_fd_in_watch(chr);
/*
* We can't call qemu_chr_fe_set_handlers() directly here
* since chardev might be running in the monitor I/O
* thread. Schedule a bottom half.
*/
aio_bh_schedule_oneshot(iothread_get_aio_context(mon_iothread),
monitor_qmp_setup_handlers_bh, mon);
/* The bottom half will add @mon to @mon_list */
} else {
qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
monitor_qmp_read, monitor_qmp_event,
NULL, &mon->common, NULL, true);
monitor_list_append(&mon->common);
}
}

4
monitor/trace-events
View File

@ -5,7 +5,9 @@ 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"
monitor_suspend(void *ptr, int cnt) "mon %p: %d"
# qmp.c
monitor_qmp_cmd_in_band(const char *id) "%s"
monitor_qmp_cmd_out_of_band(const char *id) "%s"
handle_qmp_command(void *mon, const char *req) "mon %p req: %s"