diff options
Diffstat (limited to 'monitor.c')
| -rw-r--r-- | monitor.c | 139 |
1 files changed, 69 insertions, 70 deletions
@@ -263,10 +263,11 @@ typedef struct QMPRequest QMPRequest; /* QMP checker flags */ #define QMP_ACCEPT_UNKNOWNS 1 -/* Protects mon_list, monitor_qapi_event_state. */ +/* Protects mon_list, monitor_qapi_event_state, monitor_destroyed. */ static QemuMutex monitor_lock; static GHashTable *monitor_qapi_event_state; static QTAILQ_HEAD(mon_list, Monitor) mon_list; +static bool monitor_destroyed; /* Protects mon_fdsets */ static QemuMutex mon_fdsets_lock; @@ -4109,8 +4110,12 @@ static void monitor_qmp_dispatch(Monitor *mon, QObject *req, QObject *id) * 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 mon->qmp.qmp_queue_lock held, and the caller is responsible + * to release it. */ -static QMPRequest *monitor_qmp_requests_pop_any(void) +static QMPRequest *monitor_qmp_requests_pop_any_with_lock(void) { QMPRequest *req_obj = NULL; Monitor *mon; @@ -4120,10 +4125,11 @@ static QMPRequest *monitor_qmp_requests_pop_any(void) QTAILQ_FOREACH(mon, &mon_list, entry) { qemu_mutex_lock(&mon->qmp.qmp_queue_lock); req_obj = g_queue_pop_head(mon->qmp.qmp_requests); - qemu_mutex_unlock(&mon->qmp.qmp_queue_lock); if (req_obj) { + /* With the lock of corresponding queue held */ break; } + qemu_mutex_unlock(&mon->qmp.qmp_queue_lock); } if (req_obj) { @@ -4142,30 +4148,34 @@ static QMPRequest *monitor_qmp_requests_pop_any(void) static void monitor_qmp_bh_dispatcher(void *data) { - QMPRequest *req_obj = monitor_qmp_requests_pop_any(); + QMPRequest *req_obj = monitor_qmp_requests_pop_any_with_lock(); QDict *rsp; bool need_resume; + Monitor *mon; if (!req_obj) { return; } + mon = req_obj->mon; /* qmp_oob_enabled() might change after "qmp_capabilities" */ - need_resume = !qmp_oob_enabled(req_obj->mon); + need_resume = !qmp_oob_enabled(mon) || + mon->qmp.qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1; + qemu_mutex_unlock(&mon->qmp.qmp_queue_lock); if (req_obj->req) { trace_monitor_qmp_cmd_in_band(qobject_get_try_str(req_obj->id) ?: ""); - monitor_qmp_dispatch(req_obj->mon, req_obj->req, req_obj->id); + monitor_qmp_dispatch(mon, req_obj->req, req_obj->id); } else { assert(req_obj->err); rsp = qmp_error_response(req_obj->err); req_obj->err = NULL; - monitor_qmp_respond(req_obj->mon, rsp, NULL); + monitor_qmp_respond(mon, rsp, NULL); qobject_unref(rsp); } if (need_resume) { /* Pairs with the monitor_suspend() in handle_qmp_command() */ - monitor_resume(req_obj->mon); + monitor_resume(mon); } qmp_request_free(req_obj); @@ -4173,8 +4183,6 @@ static void monitor_qmp_bh_dispatcher(void *data) qemu_bh_schedule(qmp_dispatcher_bh); } -#define QMP_REQ_QUEUE_LEN_MAX (8) - static void handle_qmp_command(void *opaque, QObject *req, Error *err) { Monitor *mon = opaque; @@ -4216,28 +4224,14 @@ static void handle_qmp_command(void *opaque, QObject *req, Error *err) qemu_mutex_lock(&mon->qmp.qmp_queue_lock); /* - * If OOB is not enabled on the current monitor, we'll emulate the - * old behavior that we won't process the current monitor any more - * until it has responded. This helps make sure that as long as - * OOB is not enabled, the server will never drop any command. + * 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)) { + if (!qmp_oob_enabled(mon) || + mon->qmp.qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1) { monitor_suspend(mon); - } else { - /* Drop the request if queue is full. */ - if (mon->qmp.qmp_requests->length >= QMP_REQ_QUEUE_LEN_MAX) { - qemu_mutex_unlock(&mon->qmp.qmp_queue_lock); - /* - * FIXME @id's scope is just @mon, and broadcasting it is - * wrong. If another monitor's client has a command with - * the same ID in flight, the event will incorrectly claim - * that command was dropped. - */ - qapi_event_send_command_dropped(id, - COMMAND_DROP_REASON_QUEUE_FULL); - qmp_request_free(req_obj); - return; - } } /* @@ -4245,6 +4239,7 @@ static void handle_qmp_command(void *opaque, QObject *req, Error *err) * handled in time order. Ownership for req_obj, req, id, * etc. will be delivered to the handler side. */ + assert(mon->qmp.qmp_requests->length < QMP_REQ_QUEUE_LEN_MAX); g_queue_push_tail(mon->qmp.qmp_requests, req_obj); qemu_mutex_unlock(&mon->qmp.qmp_queue_lock); @@ -4297,7 +4292,7 @@ int monitor_suspend(Monitor *mon) atomic_inc(&mon->suspend_cnt); - if (monitor_is_qmp(mon) && mon->use_io_thread) { + 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. @@ -4309,6 +4304,13 @@ int monitor_suspend(Monitor *mon) 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)) { @@ -4316,20 +4318,22 @@ void monitor_resume(Monitor *mon) } if (atomic_dec_fetch(&mon->suspend_cnt) == 0) { - if (monitor_is_qmp(mon)) { - /* - * For QMP monitors that are running in the I/O thread, - * let's kick the thread in case it's sleeping. - */ - if (mon->use_io_thread) { - aio_notify(iothread_get_aio_context(mon_iothread)); - } + 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)) { assert(mon->rs); readline_show_prompt(mon->rs); } - qemu_chr_fe_accept_input(&mon->chr); + + aio_bh_schedule_oneshot(ctx, monitor_accept_input, mon); } + trace_monitor_suspend(mon, -1); } @@ -4453,16 +4457,6 @@ static void sortcmdlist(void) qsort((void *)info_cmds, array_num, elem_size, compare_mon_cmd); } -static GMainContext *monitor_get_io_context(void) -{ - return iothread_get_g_main_context(mon_iothread); -} - -static AioContext *monitor_get_aio_context(void) -{ - return iothread_get_aio_context(mon_iothread); -} - static void monitor_iothread_init(void) { mon_iothread = iothread_create("mon_iothread", &error_abort); @@ -4539,8 +4533,21 @@ void error_vprintf_unless_qmp(const char *fmt, va_list ap) static void monitor_list_append(Monitor *mon) { qemu_mutex_lock(&monitor_lock); - QTAILQ_INSERT_HEAD(&mon_list, mon, entry); + /* + * 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_qmp_setup_handlers_bh(void *opaque) @@ -4549,7 +4556,7 @@ static void monitor_qmp_setup_handlers_bh(void *opaque) GMainContext *context; assert(mon->use_io_thread); - context = monitor_get_io_context(); + context = iothread_get_g_main_context(mon_iothread); assert(context); qemu_chr_fe_set_handlers(&mon->chr, monitor_can_read, monitor_qmp_read, monitor_qmp_event, NULL, mon, context, true); @@ -4560,21 +4567,12 @@ void monitor_init(Chardev *chr, int flags) { Monitor *mon = g_malloc(sizeof(*mon)); bool use_readline = flags & MONITOR_USE_READLINE; - bool use_oob = flags & MONITOR_USE_OOB; - if (use_oob) { - if (CHARDEV_IS_MUX(chr)) { - error_report("Monitor out-of-band is not supported with " - "MUX typed chardev backend"); - exit(1); - } - if (use_readline) { - error_report("Monitor out-of-band is only supported by QMP"); - exit(1); - } - } - - monitor_data_init(mon, false, use_oob); + /* Note: we run QMP monitor in I/O thread when @chr supports that */ + monitor_data_init(mon, false, + (flags & MONITOR_USE_CONTROL) + && qemu_chr_has_feature(chr, + QEMU_CHAR_FEATURE_GCONTEXT)); qemu_chr_fe_init(&mon->chr, chr, &error_abort); mon->flags = flags; @@ -4601,7 +4599,7 @@ void monitor_init(Chardev *chr, int flags) * since chardev might be running in the monitor I/O * thread. Schedule a bottom half. */ - aio_bh_schedule_oneshot(monitor_get_aio_context(), + 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 */ return; @@ -4634,10 +4632,14 @@ void monitor_cleanup(void) /* Flush output buffers and destroy monitors */ qemu_mutex_lock(&monitor_lock); + monitor_destroyed = true; QTAILQ_FOREACH_SAFE(mon, &mon_list, entry, next) { 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); @@ -4665,9 +4667,6 @@ QemuOptsList qemu_mon_opts = { },{ .name = "pretty", .type = QEMU_OPT_BOOL, - },{ - .name = "x-oob", - .type = QEMU_OPT_BOOL, }, { /* end of list */ } }, |