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monitor: Split out monitor/monitor.c

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

What remains in monitor/misc.c after this patch is mostly monitor
command implementations (which could move to hmp-cmds.c or qmp-cmds.c
later) and code that requires a system emulator or is even
target-dependent (including HMP command completion code).

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 all
monitor parts can be cleaned up later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-13-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Superfluous #include dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This commit is contained in:
Kevin Wolf 2019-06-13 17:34:02 +02:00 committed by Markus Armbruster
parent ed7bda5d07
commit 1d95db745b
7 changed files with 640 additions and 599 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
MAINTAINERS
View File

@ -1920,6 +1920,7 @@ M: Dr. David Alan Gilbert <dgilbert@redhat.com>
S: Maintained
F: monitor/monitor-internal.h
F: monitor/misc.c
F: monitor/monitor.c
F: monitor/hmp*
F: hmp.h
F: hmp-commands*.hx
@ -2044,6 +2045,7 @@ S: Supported
F: monitor/monitor-internal.h
F: monitor/qmp*
F: monitor/misc.c
F: monitor/monitor.c
F: docs/devel/*qmp-*
F: docs/interop/*qmp-*
F: scripts/qmp/

1
include/monitor/monitor.h
View File

@ -19,6 +19,7 @@ typedef struct MonitorHMP MonitorHMP;
bool monitor_cur_is_qmp(void);
void monitor_init_globals(void);
void monitor_init_globals_core(void);
void monitor_init(Chardev *chr, int flags);
void monitor_cleanup(void);

2
monitor/Makefile.objs
View File

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

598
monitor/misc.c
View File

@ -54,7 +54,6 @@
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/qstring.h"
#include "qom/object_interfaces.h"
#include "trace.h"
#include "trace/control.h"
#include "monitor/hmp-target.h"
#ifdef CONFIG_TRACE_SIMPLE
@ -71,7 +70,6 @@
#include "qapi/error.h"
#include "qapi/qmp-event.h"
#include "qapi/qapi-introspect.h"
#include "sysemu/qtest.h"
#include "sysemu/cpus.h"
#include "qemu/cutils.h"
#include "tcg/tcg.h"
@ -107,427 +105,15 @@ struct MonFdset {
QLIST_ENTRY(MonFdset) next;
};
/*
* To prevent flooding clients, events can be throttled. The
* throttling is calculated globally, rather than per-Monitor
* instance.
*/
typedef struct MonitorQAPIEventState {
QAPIEvent event; /* Throttling state for this event type and... */
QDict *data; /* ... data, see qapi_event_throttle_equal() */
QEMUTimer *timer; /* Timer for handling delayed events */
QDict *qdict; /* Delayed event (if any) */
} MonitorQAPIEventState;
typedef struct {
int64_t rate; /* Minimum time (in ns) between two events */
} MonitorQAPIEventConf;
/* Shared monitor I/O thread */
IOThread *mon_iothread;
/* Bottom half to dispatch the requests received from I/O thread */
QEMUBH *qmp_dispatcher_bh;
/* QMP checker flags */
#define QMP_ACCEPT_UNKNOWNS 1
/* Protects mon_list, monitor_qapi_event_state, monitor_destroyed. */
QemuMutex monitor_lock;
static GHashTable *monitor_qapi_event_state;
MonitorList mon_list;
static bool monitor_destroyed;
/* Protects mon_fdsets */
static QemuMutex mon_fdsets_lock;
static QLIST_HEAD(, MonFdset) mon_fdsets;
int mon_refcount;
static HMPCommand hmp_info_cmds[];
__thread Monitor *cur_mon;
/**
* Is @mon is using readline?
* Note: not all HMP monitors use readline, e.g., gdbserver has a
* non-interactive HMP monitor, so readline is not used there.
*/
static inline bool monitor_uses_readline(const Monitor *mon)
{
return mon->flags & MONITOR_USE_READLINE;
}
static inline bool monitor_is_hmp_non_interactive(const Monitor *mon)
{
return !monitor_is_qmp(mon) && !monitor_uses_readline(mon);
}
/*
* Return the clock to use for recording an event's time.
* It's QEMU_CLOCK_REALTIME, except for qtests it's
* QEMU_CLOCK_VIRTUAL, to support testing rate limits.
* Beware: result is invalid before configure_accelerator().
*/
static inline QEMUClockType monitor_get_event_clock(void)
{
return qtest_enabled() ? QEMU_CLOCK_VIRTUAL : QEMU_CLOCK_REALTIME;
}
/**
* Is the current monitor, if any, a QMP monitor?
*/
bool monitor_cur_is_qmp(void)
{
return cur_mon && monitor_is_qmp(cur_mon);
}
static void monitor_flush_locked(Monitor *mon);
static gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond,
void *opaque)
{
Monitor *mon = opaque;
qemu_mutex_lock(&mon->mon_lock);
mon->out_watch = 0;
monitor_flush_locked(mon);
qemu_mutex_unlock(&mon->mon_lock);
return FALSE;
}
/* Caller must hold mon->mon_lock */
static void monitor_flush_locked(Monitor *mon)
{
int rc;
size_t len;
const char *buf;
if (mon->skip_flush) {
return;
}
buf = qstring_get_str(mon->outbuf);
len = qstring_get_length(mon->outbuf);
if (len && !mon->mux_out) {
rc = qemu_chr_fe_write(&mon->chr, (const uint8_t *) buf, len);
if ((rc < 0 && errno != EAGAIN) || (rc == len)) {
/* all flushed or error */
qobject_unref(mon->outbuf);
mon->outbuf = qstring_new();
return;
}
if (rc > 0) {
/* partial write */
QString *tmp = qstring_from_str(buf + rc);
qobject_unref(mon->outbuf);
mon->outbuf = tmp;
}
if (mon->out_watch == 0) {
mon->out_watch =
qemu_chr_fe_add_watch(&mon->chr, G_IO_OUT | G_IO_HUP,
monitor_unblocked, mon);
}
}
}
void monitor_flush(Monitor *mon)
{
qemu_mutex_lock(&mon->mon_lock);
monitor_flush_locked(mon);
qemu_mutex_unlock(&mon->mon_lock);
}
/* flush at every end of line */
int monitor_puts(Monitor *mon, const char *str)
{
int i;
char c;
qemu_mutex_lock(&mon->mon_lock);
for (i = 0; str[i]; i++) {
c = str[i];
if (c == '\n') {
qstring_append_chr(mon->outbuf, '\r');
}
qstring_append_chr(mon->outbuf, c);
if (c == '\n') {
monitor_flush_locked(mon);
}
}
qemu_mutex_unlock(&mon->mon_lock);
return i;
}
int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
{
char *buf;
int n;
if (!mon)
return -1;
if (monitor_is_qmp(mon)) {
return -1;
}
buf = g_strdup_vprintf(fmt, ap);
n = monitor_puts(mon, buf);
g_free(buf);
return n;
}
int monitor_printf(Monitor *mon, const char *fmt, ...)
{
int ret;
va_list ap;
va_start(ap, fmt);
ret = monitor_vprintf(mon, fmt, ap);
va_end(ap);
return ret;
}
static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT__MAX] = {
/* Limit guest-triggerable events to 1 per second */
[QAPI_EVENT_RTC_CHANGE] = { 1000 * SCALE_MS },
[QAPI_EVENT_WATCHDOG] = { 1000 * SCALE_MS },
[QAPI_EVENT_BALLOON_CHANGE] = { 1000 * SCALE_MS },
[QAPI_EVENT_QUORUM_REPORT_BAD] = { 1000 * SCALE_MS },
[QAPI_EVENT_QUORUM_FAILURE] = { 1000 * SCALE_MS },
[QAPI_EVENT_VSERPORT_CHANGE] = { 1000 * SCALE_MS },
};
/*
* Broadcast an event to all monitors.
* @qdict is the event object. Its member "event" must match @event.
* Caller must hold monitor_lock.
*/
static void monitor_qapi_event_emit(QAPIEvent event, QDict *qdict)
{
Monitor *mon;
MonitorQMP *qmp_mon;
trace_monitor_protocol_event_emit(event, qdict);
QTAILQ_FOREACH(mon, &mon_list, entry) {
if (!monitor_is_qmp(mon)) {
continue;
}
qmp_mon = container_of(mon, MonitorQMP, common);
if (qmp_mon->commands != &qmp_cap_negotiation_commands) {
qmp_send_response(qmp_mon, qdict);
}
}
}
static void monitor_qapi_event_handler(void *opaque);
/*
* Queue a new event for emission to Monitor instances,
* applying any rate limiting if required.
*/
static void
monitor_qapi_event_queue_no_reenter(QAPIEvent event, QDict *qdict)
{
MonitorQAPIEventConf *evconf;
MonitorQAPIEventState *evstate;
assert(event < QAPI_EVENT__MAX);
evconf = &monitor_qapi_event_conf[event];
trace_monitor_protocol_event_queue(event, qdict, evconf->rate);
qemu_mutex_lock(&monitor_lock);
if (!evconf->rate) {
/* Unthrottled event */
monitor_qapi_event_emit(event, qdict);
} else {
QDict *data = qobject_to(QDict, qdict_get(qdict, "data"));
MonitorQAPIEventState key = { .event = event, .data = data };
evstate = g_hash_table_lookup(monitor_qapi_event_state, &key);
assert(!evstate || timer_pending(evstate->timer));
if (evstate) {
/*
* Timer is pending for (at least) evconf->rate ns after
* last send. Store event for sending when timer fires,
* replacing a prior stored event if any.
*/
qobject_unref(evstate->qdict);
evstate->qdict = qobject_ref(qdict);
} else {
/*
* Last send was (at least) evconf->rate ns ago.
* Send immediately, and arm the timer to call
* monitor_qapi_event_handler() in evconf->rate ns. Any
* events arriving before then will be delayed until then.
*/
int64_t now = qemu_clock_get_ns(monitor_get_event_clock());
monitor_qapi_event_emit(event, qdict);
evstate = g_new(MonitorQAPIEventState, 1);
evstate->event = event;
evstate->data = qobject_ref(data);
evstate->qdict = NULL;
evstate->timer = timer_new_ns(monitor_get_event_clock(),
monitor_qapi_event_handler,
evstate);
g_hash_table_add(monitor_qapi_event_state, evstate);
timer_mod_ns(evstate->timer, now + evconf->rate);
}
}
qemu_mutex_unlock(&monitor_lock);
}
void qapi_event_emit(QAPIEvent event, QDict *qdict)
{
/*
* monitor_qapi_event_queue_no_reenter() is not reentrant: it
* would deadlock on monitor_lock. Work around by queueing
* events in thread-local storage.
* TODO: remove this, make it re-enter safe.
*/
typedef struct MonitorQapiEvent {
QAPIEvent event;
QDict *qdict;
QSIMPLEQ_ENTRY(MonitorQapiEvent) entry;
} MonitorQapiEvent;
static __thread QSIMPLEQ_HEAD(, MonitorQapiEvent) event_queue;
static __thread bool reentered;
MonitorQapiEvent *ev;
if (!reentered) {
QSIMPLEQ_INIT(&event_queue);
}
ev = g_new(MonitorQapiEvent, 1);
ev->qdict = qobject_ref(qdict);
ev->event = event;
QSIMPLEQ_INSERT_TAIL(&event_queue, ev, entry);
if (reentered) {
return;
}
reentered = true;
while ((ev = QSIMPLEQ_FIRST(&event_queue)) != NULL) {
QSIMPLEQ_REMOVE_HEAD(&event_queue, entry);
monitor_qapi_event_queue_no_reenter(ev->event, ev->qdict);
qobject_unref(ev->qdict);
g_free(ev);
}
reentered = false;
}
/*
* This function runs evconf->rate ns after sending a throttled
* event.
* If another event has since been stored, send it.
*/
static void monitor_qapi_event_handler(void *opaque)
{
MonitorQAPIEventState *evstate = opaque;
MonitorQAPIEventConf *evconf = &monitor_qapi_event_conf[evstate->event];
trace_monitor_protocol_event_handler(evstate->event, evstate->qdict);
qemu_mutex_lock(&monitor_lock);
if (evstate->qdict) {
int64_t now = qemu_clock_get_ns(monitor_get_event_clock());
monitor_qapi_event_emit(evstate->event, evstate->qdict);
qobject_unref(evstate->qdict);
evstate->qdict = NULL;
timer_mod_ns(evstate->timer, now + evconf->rate);
} else {
g_hash_table_remove(monitor_qapi_event_state, evstate);
qobject_unref(evstate->data);
timer_free(evstate->timer);
g_free(evstate);
}
qemu_mutex_unlock(&monitor_lock);
}
static unsigned int qapi_event_throttle_hash(const void *key)
{
const MonitorQAPIEventState *evstate = key;
unsigned int hash = evstate->event * 255;
if (evstate->event == QAPI_EVENT_VSERPORT_CHANGE) {
hash += g_str_hash(qdict_get_str(evstate->data, "id"));
}
if (evstate->event == QAPI_EVENT_QUORUM_REPORT_BAD) {
hash += g_str_hash(qdict_get_str(evstate->data, "node-name"));
}
return hash;
}
static gboolean qapi_event_throttle_equal(const void *a, const void *b)
{
const MonitorQAPIEventState *eva = a;
const MonitorQAPIEventState *evb = b;
if (eva->event != evb->event) {
return FALSE;
}
if (eva->event == QAPI_EVENT_VSERPORT_CHANGE) {
return !strcmp(qdict_get_str(eva->data, "id"),
qdict_get_str(evb->data, "id"));
}
if (eva->event == QAPI_EVENT_QUORUM_REPORT_BAD) {
return !strcmp(qdict_get_str(eva->data, "node-name"),
qdict_get_str(evb->data, "node-name"));
}
return TRUE;
}
static void monitor_qapi_event_init(void)
{
monitor_qapi_event_state = g_hash_table_new(qapi_event_throttle_hash,
qapi_event_throttle_equal);
}
static void monitor_iothread_init(void);
void monitor_data_init(Monitor *mon, int flags, bool skip_flush,
bool use_io_thread)
{
if (use_io_thread && !mon_iothread) {
monitor_iothread_init();
}
qemu_mutex_init(&mon->mon_lock);
mon->outbuf = qstring_new();
mon->skip_flush = skip_flush;
mon->use_io_thread = use_io_thread;
mon->flags = flags;
}
static void monitor_data_destroy(Monitor *mon)
{
g_free(mon->mon_cpu_path);
qemu_chr_fe_deinit(&mon->chr, false);
if (monitor_is_qmp(mon)) {
monitor_data_destroy_qmp(container_of(mon, MonitorQMP, common));
} else {
readline_free(container_of(mon, MonitorHMP, common)->rs);
}
qobject_unref(mon->outbuf);
qemu_mutex_destroy(&mon->mon_lock);
}
char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index,
int64_t cpu_index, Error **errp)
{
@ -2728,67 +2314,6 @@ void loadvm_completion(ReadLineState *rs, int nb_args, const char *str)
}
}
int monitor_can_read(void *opaque)
{
Monitor *mon = opaque;
return !atomic_mb_read(&mon->suspend_cnt);
}
int monitor_suspend(Monitor *mon)
{
if (monitor_is_hmp_non_interactive(mon)) {
return -ENOTTY;
}
atomic_inc(&mon->suspend_cnt);
if (mon->use_io_thread) {
/*
* Kick I/O thread to make sure this takes effect. It'll be
* evaluated again in prepare() of the watch object.
*/
aio_notify(iothread_get_aio_context(mon_iothread));
}
trace_monitor_suspend(mon, 1);
return 0;
}
static void monitor_accept_input(void *opaque)
{
Monitor *mon = opaque;
qemu_chr_fe_accept_input(&mon->chr);
}
void monitor_resume(Monitor *mon)
{
if (monitor_is_hmp_non_interactive(mon)) {
return;
}
if (atomic_dec_fetch(&mon->suspend_cnt) == 0) {
AioContext *ctx;
if (mon->use_io_thread) {
ctx = iothread_get_aio_context(mon_iothread);
} else {
ctx = qemu_get_aio_context();
}
if (!monitor_is_qmp(mon)) {
MonitorHMP *hmp_mon = container_of(mon, MonitorHMP, common);
assert(hmp_mon->rs);
readline_show_prompt(hmp_mon->rs);
}
aio_bh_schedule_oneshot(ctx, monitor_accept_input, mon);
}
trace_monitor_suspend(mon, -1);
}
static int
compare_mon_cmd(const void *a, const void *b)
{
@ -2806,135 +2331,14 @@ static void sortcmdlist(void)
compare_mon_cmd);
}
static void monitor_iothread_init(void)
{
mon_iothread = iothread_create("mon_iothread", &error_abort);
}
void monitor_init_globals(void)
{
monitor_init_globals_core();
monitor_init_qmp_commands();
monitor_qapi_event_init();
sortcmdlist();
qemu_mutex_init(&monitor_lock);
qemu_mutex_init(&mon_fdsets_lock);
/*
* The dispatcher BH must run in the main loop thread, since we
* have commands assuming that context. It would be nice to get
* rid of those assumptions.
*/
qmp_dispatcher_bh = aio_bh_new(iohandler_get_aio_context(),
monitor_qmp_bh_dispatcher,
NULL);
}
/*
* Print to current monitor if we have one, else to stderr.
*/
int error_vprintf(const char *fmt, va_list ap)
{
if (cur_mon && !monitor_cur_is_qmp()) {
return monitor_vprintf(cur_mon, fmt, ap);
}
return vfprintf(stderr, fmt, ap);
}
int error_vprintf_unless_qmp(const char *fmt, va_list ap)
{
if (!cur_mon) {
return vfprintf(stderr, fmt, ap);
}
if (!monitor_cur_is_qmp()) {
return monitor_vprintf(cur_mon, fmt, ap);
}
return -1;
}
void monitor_list_append(Monitor *mon)
{
qemu_mutex_lock(&monitor_lock);
/*
* This prevents inserting new monitors during monitor_cleanup().
* A cleaner solution would involve the main thread telling other
* threads to terminate, waiting for their termination.
*/
if (!monitor_destroyed) {
QTAILQ_INSERT_HEAD(&mon_list, mon, entry);
mon = NULL;
}
qemu_mutex_unlock(&monitor_lock);
if (mon) {
monitor_data_destroy(mon);
g_free(mon);
}
}
void monitor_init(Chardev *chr, int flags)
{
if (flags & MONITOR_USE_CONTROL) {
monitor_init_qmp(chr, flags);
} else {
monitor_init_hmp(chr, flags);
}
}
void monitor_cleanup(void)
{
/*
* We need to explicitly stop the I/O thread (but not destroy it),
* clean up the monitor resources, then destroy the I/O thread since
* we need to unregister from chardev below in
* monitor_data_destroy(), and chardev is not thread-safe yet
*/
if (mon_iothread) {
iothread_stop(mon_iothread);
}
/* Flush output buffers and destroy monitors */
qemu_mutex_lock(&monitor_lock);
monitor_destroyed = true;
while (!QTAILQ_EMPTY(&mon_list)) {
Monitor *mon = QTAILQ_FIRST(&mon_list);
QTAILQ_REMOVE(&mon_list, mon, entry);
/* Permit QAPI event emission from character frontend release */
qemu_mutex_unlock(&monitor_lock);
monitor_flush(mon);
monitor_data_destroy(mon);
qemu_mutex_lock(&monitor_lock);
g_free(mon);
}
qemu_mutex_unlock(&monitor_lock);
/* QEMUBHs needs to be deleted before destroying the I/O thread */
qemu_bh_delete(qmp_dispatcher_bh);
qmp_dispatcher_bh = NULL;
if (mon_iothread) {
iothread_destroy(mon_iothread);
mon_iothread = NULL;
}
}
QemuOptsList qemu_mon_opts = {
.name = "mon",
.implied_opt_name = "chardev",
.head = QTAILQ_HEAD_INITIALIZER(qemu_mon_opts.head),
.desc = {
{
.name = "mode",
.type = QEMU_OPT_STRING,
},{
.name = "chardev",
.type = QEMU_OPT_STRING,
},{
.name = "pretty",
.type = QEMU_OPT_BOOL,
},
{ /* end of list */ }
},
};
HotpluggableCPUList *qmp_query_hotpluggable_cpus(Error **errp)
{
MachineState *ms = MACHINE(qdev_get_machine());

1
monitor/monitor-internal.h
View File

@ -167,6 +167,7 @@ void monitor_init_hmp(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);
void monitor_data_destroy(Monitor *mon);
int monitor_can_read(void *opaque);
void monitor_list_append(Monitor *mon);
void monitor_fdsets_cleanup(void);

633
monitor/monitor.c Normal file
View File

@ -0,0 +1,633 @@
/*
* 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 "monitor-internal.h"
#include "qapi/error.h"
#include "qapi/qapi-emit-events.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
#include "qemu/error-report.h"
#include "qemu/option.h"
#include "sysemu/qtest.h"
#include "trace.h"
/*
* To prevent flooding clients, events can be throttled. The
* throttling is calculated globally, rather than per-Monitor
* instance.
*/
typedef struct MonitorQAPIEventState {
QAPIEvent event; /* Throttling state for this event type and... */
QDict *data; /* ... data, see qapi_event_throttle_equal() */
QEMUTimer *timer; /* Timer for handling delayed events */
QDict *qdict; /* Delayed event (if any) */
} MonitorQAPIEventState;
typedef struct {
int64_t rate; /* Minimum time (in ns) between two events */
} MonitorQAPIEventConf;
/* Shared monitor I/O thread */
IOThread *mon_iothread;
/* Bottom half to dispatch the requests received from I/O thread */
QEMUBH *qmp_dispatcher_bh;
/* Protects mon_list, monitor_qapi_event_state, monitor_destroyed. */
QemuMutex monitor_lock;
static GHashTable *monitor_qapi_event_state;
MonitorList mon_list;
int mon_refcount;
static bool monitor_destroyed;
__thread Monitor *cur_mon;
/**
* Is the current monitor, if any, a QMP monitor?
*/
bool monitor_cur_is_qmp(void)
{
return cur_mon && monitor_is_qmp(cur_mon);
}
/**
* Is @mon is using readline?
* Note: not all HMP monitors use readline, e.g., gdbserver has a
* non-interactive HMP monitor, so readline is not used there.
*/
static inline bool monitor_uses_readline(const Monitor *mon)
{
return mon->flags & MONITOR_USE_READLINE;
}
static inline bool monitor_is_hmp_non_interactive(const Monitor *mon)
{
return !monitor_is_qmp(mon) && !monitor_uses_readline(mon);
}
static void monitor_flush_locked(Monitor *mon);
static gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond,
void *opaque)
{
Monitor *mon = opaque;
qemu_mutex_lock(&mon->mon_lock);
mon->out_watch = 0;
monitor_flush_locked(mon);
qemu_mutex_unlock(&mon->mon_lock);
return FALSE;
}
/* Caller must hold mon->mon_lock */
static void monitor_flush_locked(Monitor *mon)
{
int rc;
size_t len;
const char *buf;
if (mon->skip_flush) {
return;
}
buf = qstring_get_str(mon->outbuf);
len = qstring_get_length(mon->outbuf);
if (len && !mon->mux_out) {
rc = qemu_chr_fe_write(&mon->chr, (const uint8_t *) buf, len);
if ((rc < 0 && errno != EAGAIN) || (rc == len)) {
/* all flushed or error */
qobject_unref(mon->outbuf);
mon->outbuf = qstring_new();
return;
}
if (rc > 0) {
/* partial write */
QString *tmp = qstring_from_str(buf + rc);
qobject_unref(mon->outbuf);
mon->outbuf = tmp;
}
if (mon->out_watch == 0) {
mon->out_watch =
qemu_chr_fe_add_watch(&mon->chr, G_IO_OUT | G_IO_HUP,
monitor_unblocked, mon);
}
}
}
void monitor_flush(Monitor *mon)
{
qemu_mutex_lock(&mon->mon_lock);
monitor_flush_locked(mon);
qemu_mutex_unlock(&mon->mon_lock);
}
/* flush at every end of line */
int monitor_puts(Monitor *mon, const char *str)
{
int i;
char c;
qemu_mutex_lock(&mon->mon_lock);
for (i = 0; str[i]; i++) {
c = str[i];
if (c == '\n') {
qstring_append_chr(mon->outbuf, '\r');
}
qstring_append_chr(mon->outbuf, c);
if (c == '\n') {
monitor_flush_locked(mon);
}
}
qemu_mutex_unlock(&mon->mon_lock);
return i;
}
int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
{
char *buf;
int n;
if (!mon) {
return -1;
}
if (monitor_is_qmp(mon)) {
return -1;
}
buf = g_strdup_vprintf(fmt, ap);
n = monitor_puts(mon, buf);
g_free(buf);
return n;
}
int monitor_printf(Monitor *mon, const char *fmt, ...)
{
int ret;
va_list ap;
va_start(ap, fmt);
ret = monitor_vprintf(mon, fmt, ap);
va_end(ap);
return ret;
}
/*
* Print to current monitor if we have one, else to stderr.
*/
int error_vprintf(const char *fmt, va_list ap)
{
if (cur_mon && !monitor_cur_is_qmp()) {
return monitor_vprintf(cur_mon, fmt, ap);
}
return vfprintf(stderr, fmt, ap);
}
int error_vprintf_unless_qmp(const char *fmt, va_list ap)
{
if (!cur_mon) {
return vfprintf(stderr, fmt, ap);
}
if (!monitor_cur_is_qmp()) {
return monitor_vprintf(cur_mon, fmt, ap);
}
return -1;
}
static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT__MAX] = {
/* Limit guest-triggerable events to 1 per second */
[QAPI_EVENT_RTC_CHANGE] = { 1000 * SCALE_MS },
[QAPI_EVENT_WATCHDOG] = { 1000 * SCALE_MS },
[QAPI_EVENT_BALLOON_CHANGE] = { 1000 * SCALE_MS },
[QAPI_EVENT_QUORUM_REPORT_BAD] = { 1000 * SCALE_MS },
[QAPI_EVENT_QUORUM_FAILURE] = { 1000 * SCALE_MS },
[QAPI_EVENT_VSERPORT_CHANGE] = { 1000 * SCALE_MS },
};
/*
* Return the clock to use for recording an event's time.
* It's QEMU_CLOCK_REALTIME, except for qtests it's
* QEMU_CLOCK_VIRTUAL, to support testing rate limits.
* Beware: result is invalid before configure_accelerator().
*/
static inline QEMUClockType monitor_get_event_clock(void)
{
return qtest_enabled() ? QEMU_CLOCK_VIRTUAL : QEMU_CLOCK_REALTIME;
}
/*
* Broadcast an event to all monitors.
* @qdict is the event object. Its member "event" must match @event.
* Caller must hold monitor_lock.
*/
static void monitor_qapi_event_emit(QAPIEvent event, QDict *qdict)
{
Monitor *mon;
MonitorQMP *qmp_mon;
trace_monitor_protocol_event_emit(event, qdict);
QTAILQ_FOREACH(mon, &mon_list, entry) {
if (!monitor_is_qmp(mon)) {
continue;
}
qmp_mon = container_of(mon, MonitorQMP, common);
if (qmp_mon->commands != &qmp_cap_negotiation_commands) {
qmp_send_response(qmp_mon, qdict);
}
}
}
static void monitor_qapi_event_handler(void *opaque);
/*
* Queue a new event for emission to Monitor instances,
* applying any rate limiting if required.
*/
static void
monitor_qapi_event_queue_no_reenter(QAPIEvent event, QDict *qdict)
{
MonitorQAPIEventConf *evconf;
MonitorQAPIEventState *evstate;
assert(event < QAPI_EVENT__MAX);
evconf = &monitor_qapi_event_conf[event];
trace_monitor_protocol_event_queue(event, qdict, evconf->rate);
qemu_mutex_lock(&monitor_lock);
if (!evconf->rate) {
/* Unthrottled event */
monitor_qapi_event_emit(event, qdict);
} else {
QDict *data = qobject_to(QDict, qdict_get(qdict, "data"));
MonitorQAPIEventState key = { .event = event, .data = data };
evstate = g_hash_table_lookup(monitor_qapi_event_state, &key);
assert(!evstate || timer_pending(evstate->timer));
if (evstate) {
/*
* Timer is pending for (at least) evconf->rate ns after
* last send. Store event for sending when timer fires,
* replacing a prior stored event if any.
*/
qobject_unref(evstate->qdict);
evstate->qdict = qobject_ref(qdict);
} else {
/*
* Last send was (at least) evconf->rate ns ago.
* Send immediately, and arm the timer to call
* monitor_qapi_event_handler() in evconf->rate ns. Any
* events arriving before then will be delayed until then.
*/
int64_t now = qemu_clock_get_ns(monitor_get_event_clock());
monitor_qapi_event_emit(event, qdict);
evstate = g_new(MonitorQAPIEventState, 1);
evstate->event = event;
evstate->data = qobject_ref(data);
evstate->qdict = NULL;
evstate->timer = timer_new_ns(monitor_get_event_clock(),
monitor_qapi_event_handler,
evstate);
g_hash_table_add(monitor_qapi_event_state, evstate);
timer_mod_ns(evstate->timer, now + evconf->rate);
}
}
qemu_mutex_unlock(&monitor_lock);
}
void qapi_event_emit(QAPIEvent event, QDict *qdict)
{
/*
* monitor_qapi_event_queue_no_reenter() is not reentrant: it
* would deadlock on monitor_lock. Work around by queueing
* events in thread-local storage.
* TODO: remove this, make it re-enter safe.
*/
typedef struct MonitorQapiEvent {
QAPIEvent event;
QDict *qdict;
QSIMPLEQ_ENTRY(MonitorQapiEvent) entry;
} MonitorQapiEvent;
static __thread QSIMPLEQ_HEAD(, MonitorQapiEvent) event_queue;
static __thread bool reentered;
MonitorQapiEvent *ev;
if (!reentered) {
QSIMPLEQ_INIT(&event_queue);
}
ev = g_new(MonitorQapiEvent, 1);
ev->qdict = qobject_ref(qdict);
ev->event = event;
QSIMPLEQ_INSERT_TAIL(&event_queue, ev, entry);
if (reentered) {
return;
}
reentered = true;
while ((ev = QSIMPLEQ_FIRST(&event_queue)) != NULL) {
QSIMPLEQ_REMOVE_HEAD(&event_queue, entry);
monitor_qapi_event_queue_no_reenter(ev->event, ev->qdict);
qobject_unref(ev->qdict);
g_free(ev);
}
reentered = false;
}
/*
* This function runs evconf->rate ns after sending a throttled
* event.
* If another event has since been stored, send it.
*/
static void monitor_qapi_event_handler(void *opaque)
{
MonitorQAPIEventState *evstate = opaque;
MonitorQAPIEventConf *evconf = &monitor_qapi_event_conf[evstate->event];
trace_monitor_protocol_event_handler(evstate->event, evstate->qdict);
qemu_mutex_lock(&monitor_lock);
if (evstate->qdict) {
int64_t now = qemu_clock_get_ns(monitor_get_event_clock());
monitor_qapi_event_emit(evstate->event, evstate->qdict);
qobject_unref(evstate->qdict);
evstate->qdict = NULL;
timer_mod_ns(evstate->timer, now + evconf->rate);
} else {
g_hash_table_remove(monitor_qapi_event_state, evstate);
qobject_unref(evstate->data);
timer_free(evstate->timer);
g_free(evstate);
}
qemu_mutex_unlock(&monitor_lock);
}
static unsigned int qapi_event_throttle_hash(const void *key)
{
const MonitorQAPIEventState *evstate = key;
unsigned int hash = evstate->event * 255;
if (evstate->event == QAPI_EVENT_VSERPORT_CHANGE) {
hash += g_str_hash(qdict_get_str(evstate->data, "id"));
}
if (evstate->event == QAPI_EVENT_QUORUM_REPORT_BAD) {
hash += g_str_hash(qdict_get_str(evstate->data, "node-name"));
}
return hash;
}
static gboolean qapi_event_throttle_equal(const void *a, const void *b)
{
const MonitorQAPIEventState *eva = a;
const MonitorQAPIEventState *evb = b;
if (eva->event != evb->event) {
return FALSE;
}
if (eva->event == QAPI_EVENT_VSERPORT_CHANGE) {
return !strcmp(qdict_get_str(eva->data, "id"),
qdict_get_str(evb->data, "id"));
}
if (eva->event == QAPI_EVENT_QUORUM_REPORT_BAD) {
return !strcmp(qdict_get_str(eva->data, "node-name"),
qdict_get_str(evb->data, "node-name"));
}
return TRUE;
}
int monitor_suspend(Monitor *mon)
{
if (monitor_is_hmp_non_interactive(mon)) {
return -ENOTTY;
}
atomic_inc(&mon->suspend_cnt);
if (mon->use_io_thread) {
/*
* Kick I/O thread to make sure this takes effect. It'll be
* evaluated again in prepare() of the watch object.
*/
aio_notify(iothread_get_aio_context(mon_iothread));
}
trace_monitor_suspend(mon, 1);
return 0;
}
static void monitor_accept_input(void *opaque)
{
Monitor *mon = opaque;
qemu_chr_fe_accept_input(&mon->chr);
}
void monitor_resume(Monitor *mon)
{
if (monitor_is_hmp_non_interactive(mon)) {
return;
}
if (atomic_dec_fetch(&mon->suspend_cnt) == 0) {
AioContext *ctx;
if (mon->use_io_thread) {
ctx = iothread_get_aio_context(mon_iothread);
} else {
ctx = qemu_get_aio_context();
}
if (!monitor_is_qmp(mon)) {
MonitorHMP *hmp_mon = container_of(mon, MonitorHMP, common);
assert(hmp_mon->rs);
readline_show_prompt(hmp_mon->rs);
}
aio_bh_schedule_oneshot(ctx, monitor_accept_input, mon);
}
trace_monitor_suspend(mon, -1);
}
int monitor_can_read(void *opaque)
{
Monitor *mon = opaque;
return !atomic_mb_read(&mon->suspend_cnt);
}
void monitor_list_append(Monitor *mon)
{
qemu_mutex_lock(&monitor_lock);
/*
* This prevents inserting new monitors during monitor_cleanup().
* A cleaner solution would involve the main thread telling other
* threads to terminate, waiting for their termination.
*/
if (!monitor_destroyed) {
QTAILQ_INSERT_HEAD(&mon_list, mon, entry);
mon = NULL;
}
qemu_mutex_unlock(&monitor_lock);
if (mon) {
monitor_data_destroy(mon);
g_free(mon);
}
}
static void monitor_iothread_init(void)
{
mon_iothread = iothread_create("mon_iothread", &error_abort);
}
void monitor_data_init(Monitor *mon, int flags, bool skip_flush,
bool use_io_thread)
{
if (use_io_thread && !mon_iothread) {
monitor_iothread_init();
}
qemu_mutex_init(&mon->mon_lock);
mon->outbuf = qstring_new();
mon->skip_flush = skip_flush;
mon->use_io_thread = use_io_thread;
mon->flags = flags;
}
void monitor_data_destroy(Monitor *mon)
{
g_free(mon->mon_cpu_path);
qemu_chr_fe_deinit(&mon->chr, false);
if (monitor_is_qmp(mon)) {
monitor_data_destroy_qmp(container_of(mon, MonitorQMP, common));
} else {
readline_free(container_of(mon, MonitorHMP, common)->rs);
}
qobject_unref(mon->outbuf);
qemu_mutex_destroy(&mon->mon_lock);
}
void monitor_init(Chardev *chr, int flags)
{
if (flags & MONITOR_USE_CONTROL) {
monitor_init_qmp(chr, flags);
} else {
monitor_init_hmp(chr, flags);
}
}
void monitor_cleanup(void)
{
/*
* We need to explicitly stop the I/O thread (but not destroy it),
* clean up the monitor resources, then destroy the I/O thread since
* we need to unregister from chardev below in
* monitor_data_destroy(), and chardev is not thread-safe yet
*/
if (mon_iothread) {
iothread_stop(mon_iothread);
}
/* Flush output buffers and destroy monitors */
qemu_mutex_lock(&monitor_lock);
monitor_destroyed = true;
while (!QTAILQ_EMPTY(&mon_list)) {
Monitor *mon = QTAILQ_FIRST(&mon_list);
QTAILQ_REMOVE(&mon_list, mon, entry);
/* Permit QAPI event emission from character frontend release */
qemu_mutex_unlock(&monitor_lock);
monitor_flush(mon);
monitor_data_destroy(mon);
qemu_mutex_lock(&monitor_lock);
g_free(mon);
}
qemu_mutex_unlock(&monitor_lock);
/* QEMUBHs needs to be deleted before destroying the I/O thread */
qemu_bh_delete(qmp_dispatcher_bh);
qmp_dispatcher_bh = NULL;
if (mon_iothread) {
iothread_destroy(mon_iothread);
mon_iothread = NULL;
}
}
static void monitor_qapi_event_init(void)
{
monitor_qapi_event_state = g_hash_table_new(qapi_event_throttle_hash,
qapi_event_throttle_equal);
}
void monitor_init_globals_core(void)
{
monitor_qapi_event_init();
qemu_mutex_init(&monitor_lock);
/*
* The dispatcher BH must run in the main loop thread, since we
* have commands assuming that context. It would be nice to get
* rid of those assumptions.
*/
qmp_dispatcher_bh = aio_bh_new(iohandler_get_aio_context(),
monitor_qmp_bh_dispatcher,
NULL);
}
QemuOptsList qemu_mon_opts = {
.name = "mon",
.implied_opt_name = "chardev",
.head = QTAILQ_HEAD_INITIALIZER(qemu_mon_opts.head),
.desc = {
{
.name = "mode",
.type = QEMU_OPT_STRING,
},{
.name = "chardev",
.type = QEMU_OPT_STRING,
},{
.name = "pretty",
.type = QEMU_OPT_BOOL,
},
{ /* end of list */ }
},
};

2
monitor/trace-events
View File

@ -3,7 +3,7 @@
# hmp.c
handle_hmp_command(void *mon, const char *cmdline) "mon %p cmdline: %s"
# misc.c
# monitor.c
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