diff options
Diffstat (limited to 'monitor')
| -rw-r--r-- | monitor/Makefile.objs | 1 | ||||
| -rw-r--r-- | monitor/misc.c | 401 | ||||
| -rw-r--r-- | monitor/monitor-internal.h | 30 | ||||
| -rw-r--r-- | monitor/qmp.c | 406 | ||||
| -rw-r--r-- | monitor/trace-events | 4 |
5 files changed, 449 insertions, 393 deletions
diff --git a/monitor/Makefile.objs b/monitor/Makefile.objs index a7170af6e1..1037c09ff8 100644 --- a/monitor/Makefile.objs +++ b/monitor/Makefile.objs @@ -1,2 +1,3 @@ obj-y += misc.o +common-obj-y += qmp.o common-obj-y += qmp-cmds.o hmp-cmds.o diff --git a/monitor/misc.c b/monitor/misc.c index 3cdbb681fb..824d28d717 100644 --- a/monitor/misc.c +++ b/monitor/misc.c @@ -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" @@ -138,52 +134,30 @@ 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 * non-interactive HMP monitor, so readline is not used there. @@ -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); diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index ebaf0201c8..d859bd3894 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -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 diff --git a/monitor/qmp.c b/monitor/qmp.c new file mode 100644 index 0000000000..7c3d081a72 --- /dev/null +++ b/monitor/qmp.c @@ -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); + } +} diff --git a/monitor/trace-events b/monitor/trace-events index abfdf20b14..a06dde3fd3 100644 --- a/monitor/trace-events +++ b/monitor/trace-events @@ -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" |