qemu/monitor/monitor.c
Markus Armbruster d5938f29fe Clean up inclusion of sysemu/sysemu.h
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

Almost a third of its inclusions are actually superfluous.  Delete
them.  Downgrade two more to qapi/qapi-types-run-state.h, and move one
from char/serial.h to char/serial.c.

hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and
stubs/semihost.c define variables declared in sysemu/sysemu.h without
including it.  The compiler is cool with that, but include it anyway.

This doesn't reduce actual use much, as it's still included into
widely included headers.  The next commit will tackle that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-27-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2019-08-16 13:31:53 +02:00

630 lines
17 KiB
C

/*
* 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 "sysemu/sysemu.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 MonitorHMP *mon)
{
return mon->use_readline;
}
static inline bool monitor_is_hmp_non_interactive(const Monitor *mon)
{
if (monitor_is_qmp(mon)) {
return false;
}
return !monitor_uses_readline(container_of(mon, MonitorHMP, common));
}
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, bool is_qmp, bool skip_flush,
bool use_io_thread)
{
if (use_io_thread && !mon_iothread) {
monitor_iothread_init();
}
qemu_mutex_init(&mon->mon_lock);
mon->is_qmp = is_qmp;
mon->outbuf = qstring_new();
mon->skip_flush = skip_flush;
mon->use_io_thread = use_io_thread;
}
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_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 */ }
},
};