This determines whether a human monitor runs with readline for interactive use, or without readline for non-interactive use by the GDB stub. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/hmp.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/monitor/hmp.c b/monitor/hmp.c index 4ab81b5904..d5905e2279 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -50,12 +50,37 @@ static void monitor_hmp_finalize(Object *obj) { } +static bool monitor_hmp_get_readline(Object *obj, Error **errp) +{ + MonitorHMP *mon = MONITOR_HMP(obj); + + return mon->use_readline; +} + +static void monitor_hmp_set_readline(Object *obj, bool val, Error **errp) +{ + MonitorHMP *mon = MONITOR_HMP(obj); + + mon->use_readline = val; +} + static void monitor_hmp_class_init(ObjectClass *cls, const void *data) { + object_class_property_add_bool(cls, "readline", + monitor_hmp_get_readline, + monitor_hmp_set_readline); } static void monitor_hmp_init(Object *obj) { + MonitorHMP *hmp = MONITOR_HMP(obj); + + /* + * Default to common case for external HMP use, + * as opposed to non-interactive internal use + * from gdbstub + */ + hmp->use_readline = true; } static void monitor_command_cb(void *opaque, const char *cmdline, @@ -1550,6 +1575,7 @@ void monitor_new_hmp(const char *chardev_id, bool use_readline, Error **errp) id, errp, "chardev", chardev_id, + "readline", use_readline ? "yes" : "no", NULL); if (!obj) { @@ -1566,7 +1592,6 @@ void monitor_new_hmp(const char *chardev_id, bool use_readline, Error **errp) monitor_data_init(&mon->parent_obj, false, false, false); - mon->use_readline = use_readline; if (mon->use_readline) { mon->rs = readline_init(monitor_readline_printf, monitor_readline_flush, -- 2.54.0

This determines whether the QMP JSON responses are pretty printed with newlines and indentation, or compact with no extra whitespace. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/qmp.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/monitor/qmp.c b/monitor/qmp.c index 3a4e2ae0e7..ae6317b09d 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -77,8 +77,25 @@ static void monitor_qmp_finalize(Object *obj) { } +static bool monitor_qmp_get_pretty(Object *obj, Error **errp) +{ + MonitorQMP *mon = MONITOR_QMP(obj); + + return mon->pretty; +} + +static void monitor_qmp_set_pretty(Object *obj, bool val, Error **errp) +{ + MonitorQMP *mon = MONITOR_QMP(obj); + + mon->pretty = val; +} + static void monitor_qmp_class_init(ObjectClass *cls, const void *data) { + object_class_property_add_bool(cls, "pretty", + monitor_qmp_get_pretty, + monitor_qmp_set_pretty); } static void monitor_qmp_init(Object *obj) @@ -537,6 +554,7 @@ void monitor_new_qmp(const char *chardev_id, bool pretty, Error **errp) id, errp, "chardev", chardev_id, + "pretty", pretty ? "yes" : "no", NULL); if (!obj) { @@ -557,8 +575,6 @@ void monitor_new_qmp(const char *chardev_id, bool pretty, Error **errp) qemu_chr_has_feature(mon->parent_obj.chr.chr, QEMU_CHAR_FEATURE_GCONTEXT)); - mon->pretty = pretty; - qemu_mutex_init(&mon->qmp_queue_lock); mon->qmp_requests = g_queue_new(); -- 2.54.0

The 'skip_flush' field is set on the dummy throwaway HMP monitor object created by QMP's 'human-monitor-command', as an indication not to try to write data to the chardev. Instead the QMP command impl will grab the data straight out of the in-memory buffer. The flag is redundant, however, as the monitor code could instead simply check the 'fe_is_open' field on the CharFrontend, which will be false in the same scenarios that 'skip_flush' is true. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/hmp.c | 2 +- monitor/monitor-internal.h | 4 +--- monitor/monitor.c | 11 +++++++---- monitor/qmp-cmds.c | 2 +- monitor/qmp.c | 2 +- 5 files changed, 11 insertions(+), 10 deletions(-) diff --git a/monitor/hmp.c b/monitor/hmp.c index d5905e2279..516aa25d4c 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -1590,7 +1590,7 @@ void monitor_new_hmp(const char *chardev_id, bool use_readline, Error **errp) return; } - monitor_data_init(&mon->parent_obj, false, false, false); + monitor_data_init(&mon->parent_obj, false, false); if (mon->use_readline) { mon->rs = readline_init(monitor_readline_printf, diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 145d52fd71..d34f9be139 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -112,7 +112,6 @@ struct Monitor { CharFrontend chr; int suspend_cnt; /* Needs to be accessed atomically */ bool is_qmp; - bool skip_flush; bool use_io_thread; char *mon_cpu_path; @@ -194,8 +193,7 @@ extern QemuMutex monitor_lock; extern MonitorList mon_list; void monitor_complete(Monitor *mon, Error **errp); -void monitor_data_init(Monitor *mon, bool is_qmp, bool skip_flush, - bool use_io_thread); +void monitor_data_init(Monitor *mon, bool is_qmp, bool use_io_thread); void monitor_data_destroy(Monitor *mon); int monitor_can_read(void *opaque); void monitor_list_append(Monitor *mon); diff --git a/monitor/monitor.c b/monitor/monitor.c index 1f1f5fe9fe..e2b652daa8 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -187,7 +187,12 @@ void monitor_flush_locked(Monitor *mon) size_t len; const char *buf; - if (mon->skip_flush) { + /* + * When used by QMP human-monitor-command, no chardev + * will be connected, as we want to just collect the + * output in the buffer + */ + if (!mon->chr.fe_is_open) { return; } @@ -641,8 +646,7 @@ 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) +void monitor_data_init(Monitor *mon, bool is_qmp, bool use_io_thread) { if (use_io_thread && !mon_iothread) { monitor_iothread_init(); @@ -650,7 +654,6 @@ void monitor_data_init(Monitor *mon, bool is_qmp, bool skip_flush, qemu_mutex_init(&mon->mon_lock); mon->is_qmp = is_qmp; mon->outbuf = g_string_new(NULL); - mon->skip_flush = skip_flush; mon->use_io_thread = use_io_thread; } diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c index bfde769ef0..0d9adad288 100644 --- a/monitor/qmp-cmds.c +++ b/monitor/qmp-cmds.c @@ -168,7 +168,7 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index, char *output = NULL; MonitorHMP *hmp = MONITOR_HMP(object_new(TYPE_MONITOR_HMP)); - monitor_data_init(&hmp->parent_obj, false, true, false); + monitor_data_init(&hmp->parent_obj, false, false); if (has_cpu_index) { int ret = monitor_set_cpu(&hmp->parent_obj, cpu_index); diff --git a/monitor/qmp.c b/monitor/qmp.c index ae6317b09d..689cbb804c 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -571,7 +571,7 @@ void monitor_new_qmp(const char *chardev_id, bool pretty, Error **errp) qemu_chr_fe_set_echo(&mon->parent_obj.chr, true); /* Note: we run QMP monitor in I/O thread when @chr supports that */ - monitor_data_init(&mon->parent_obj, true, false, + monitor_data_init(&mon->parent_obj, true, qemu_chr_has_feature(mon->parent_obj.chr.chr, QEMU_CHAR_FEATURE_GCONTEXT)); -- 2.54.0

Start to take advantage of QOM, by using object init and finalize methods to replace monitor_data_init and monitor_data_destroy. A standalone helper is provided to enable the I/O thread for QMP where appropriate for the chardev backend. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/hmp.c | 6 +++-- monitor/monitor-internal.h | 3 +-- monitor/monitor.c | 46 +++++++++++++------------------------- monitor/qmp-cmds.c | 3 --- monitor/qmp.c | 34 +++++++++++++++------------- 5 files changed, 40 insertions(+), 52 deletions(-) diff --git a/monitor/hmp.c b/monitor/hmp.c index 516aa25d4c..2bb2333da5 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -48,6 +48,10 @@ OBJECT_DEFINE_TYPE(MonitorHMP, monitor_hmp, MONITOR_HMP, MONITOR); static void monitor_hmp_finalize(Object *obj) { + MonitorHMP *mon = MONITOR_HMP(obj); + if (mon->rs) { + readline_free(mon->rs); + } } static bool monitor_hmp_get_readline(Object *obj, Error **errp) @@ -1590,8 +1594,6 @@ void monitor_new_hmp(const char *chardev_id, bool use_readline, Error **errp) return; } - monitor_data_init(&mon->parent_obj, false, false); - if (mon->use_readline) { mon->rs = readline_init(monitor_readline_printf, monitor_readline_flush, diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index d34f9be139..6a4c3b0f37 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -193,8 +193,7 @@ extern QemuMutex monitor_lock; extern MonitorList mon_list; void monitor_complete(Monitor *mon, Error **errp); -void monitor_data_init(Monitor *mon, bool is_qmp, bool use_io_thread); -void monitor_data_destroy(Monitor *mon); +void monitor_iothread_init(Monitor *mon); int monitor_can_read(void *opaque); void monitor_list_append(Monitor *mon); void monitor_fdsets_cleanup(void); diff --git a/monitor/monitor.c b/monitor/monitor.c index e2b652daa8..ae36e996e9 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -80,6 +80,10 @@ static void monitor_finalize(Object *obj) Monitor *mon = MONITOR(obj); g_free(mon->chardev_id); + g_free(mon->mon_cpu_path); + qemu_chr_fe_deinit(&mon->chr, false); + g_string_free(mon->outbuf, true); + qemu_mutex_destroy(&mon->mon_lock); } static char *monitor_get_chardev_id(Object *obj, Error **errp) @@ -105,6 +109,11 @@ static void monitor_class_init(ObjectClass *cls, const void *data) static void monitor_init(Object *obj) { + Monitor *mon = MONITOR(obj); + + qemu_mutex_init(&mon->mon_lock); + mon->is_qmp = !!object_dynamic_cast(obj, TYPE_MONITOR_QMP); + mon->outbuf = g_string_new(NULL); } Monitor *monitor_cur(void) @@ -636,38 +645,16 @@ void monitor_list_append(Monitor *mon) qemu_mutex_unlock(&monitor_lock); if (mon) { - monitor_data_destroy(mon); object_unparent(OBJECT(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 use_io_thread) +void monitor_iothread_init(Monitor *mon) { - if (use_io_thread && !mon_iothread) { - monitor_iothread_init(); + if (!mon_iothread) { + mon_iothread = iothread_create("mon_iothread", &error_abort); } - qemu_mutex_init(&mon->mon_lock); - mon->is_qmp = is_qmp; - mon->outbuf = g_string_new(NULL); - 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, parent_obj)); - } else { - readline_free(container_of(mon, MonitorHMP, parent_obj)->rs); - } - g_string_free(mon->outbuf, true); - qemu_mutex_destroy(&mon->mon_lock); + mon->use_io_thread = true; } void monitor_cleanup(void) @@ -685,7 +672,7 @@ void monitor_cleanup(void) * Letting the iothread continue while shutting down the dispatcher * means that new requests may still be coming in. This is okay, * we'll just leave them in the queue without sending a response - * and monitor_data_destroy() will free them. + * and object finalization will free them. */ WITH_QEMU_LOCK_GUARD(&monitor_lock) { qmp_dispatcher_co_shutdown = true; @@ -699,8 +686,8 @@ 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 + * we need to unregister from chardev below in object + * finalization, and chardev is not thread-safe yet */ if (mon_iothread) { iothread_stop(mon_iothread); @@ -715,7 +702,6 @@ void monitor_cleanup(void) /* 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); object_unparent(OBJECT(mon)); } diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c index 0d9adad288..6cb0b587fb 100644 --- a/monitor/qmp-cmds.c +++ b/monitor/qmp-cmds.c @@ -168,8 +168,6 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index, char *output = NULL; MonitorHMP *hmp = MONITOR_HMP(object_new(TYPE_MONITOR_HMP)); - monitor_data_init(&hmp->parent_obj, false, false); - if (has_cpu_index) { int ret = monitor_set_cpu(&hmp->parent_obj, cpu_index); if (ret < 0) { @@ -186,7 +184,6 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index, } out: - monitor_data_destroy(&hmp->parent_obj); object_unref(hmp); return output; } diff --git a/monitor/qmp.c b/monitor/qmp.c index 689cbb804c..6e23f7f4ed 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -73,8 +73,16 @@ QmpCommandList qmp_commands, qmp_cap_negotiation_commands; OBJECT_DEFINE_TYPE(MonitorQMP, monitor_qmp, MONITOR_QMP, MONITOR); +static void monitor_qmp_cleanup_req_queue_locked(MonitorQMP *mon); + static void monitor_qmp_finalize(Object *obj) { + MonitorQMP *mon = MONITOR_QMP(obj); + + 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 bool monitor_qmp_get_pretty(Object *obj, Error **errp) @@ -98,8 +106,15 @@ static void monitor_qmp_class_init(ObjectClass *cls, const void *data) monitor_qmp_set_pretty); } +static void handle_qmp_command(void *opaque, QObject *req, Error *err); static void monitor_qmp_init(Object *obj) { + MonitorQMP *mon = MONITOR_QMP(obj); + + qemu_mutex_init(&mon->qmp_queue_lock); + mon->qmp_requests = g_queue_new(); + + json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL); } static bool qmp_oob_enabled(MonitorQMP *mon) @@ -522,14 +537,6 @@ static void monitor_qmp_event(void *opaque, QEMUChrEvent event) } } -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; @@ -571,14 +578,11 @@ void monitor_new_qmp(const char *chardev_id, bool pretty, Error **errp) qemu_chr_fe_set_echo(&mon->parent_obj.chr, true); /* Note: we run QMP monitor in I/O thread when @chr supports that */ - monitor_data_init(&mon->parent_obj, true, - qemu_chr_has_feature(mon->parent_obj.chr.chr, - QEMU_CHAR_FEATURE_GCONTEXT)); - - qemu_mutex_init(&mon->qmp_queue_lock); - mon->qmp_requests = g_queue_new(); + if (qemu_chr_has_feature(mon->parent_obj.chr.chr, + QEMU_CHAR_FEATURE_GCONTEXT)) { + monitor_iothread_init(&mon->parent_obj); + } - json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL); if (mon->parent_obj.use_io_thread) { /* * Make sure the old iowatch is gone. It's possible when -- 2.54.0

This removes the need for using monitor_is_qmp() to check the subclass type, which is an anti-pattern. Reviewed-by: Dr. David Alan Gilbert <dave@treblig.org> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/hmp.c | 13 +++++++++++++ monitor/monitor-internal.h | 7 +++++++ monitor/monitor.c | 11 ++++------- 3 files changed, 24 insertions(+), 7 deletions(-) diff --git a/monitor/hmp.c b/monitor/hmp.c index 2bb2333da5..08055839a4 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -68,11 +68,18 @@ static void monitor_hmp_set_readline(Object *obj, bool val, Error **errp) mon->use_readline = val; } +int monitor_hmp_vprintf(Monitor *mon, const char *fmt, va_list ap) + G_GNUC_PRINTF(2, 0); + static void monitor_hmp_class_init(ObjectClass *cls, const void *data) { + MonitorClass *moncls = MONITOR_CLASS(cls); + object_class_property_add_bool(cls, "readline", monitor_hmp_get_readline, monitor_hmp_set_readline); + + moncls->vprintf = monitor_hmp_vprintf; } static void monitor_hmp_init(Object *obj) @@ -87,6 +94,12 @@ static void monitor_hmp_init(Object *obj) hmp->use_readline = true; } +int monitor_hmp_vprintf(Monitor *mon, const char *fmt, va_list ap) +{ + g_autofree char *buf = g_strdup_vprintf(fmt, ap); + return monitor_puts(mon, buf); +} + static void monitor_command_cb(void *opaque, const char *cmdline, void *readline_opaque) { diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 6a4c3b0f37..23cef68153 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -104,6 +104,13 @@ typedef struct HMPCommand { struct MonitorClass { ObjectClass parent_class; + + /* + * If non-NULL, the monitor is able to print messages + * for attention of the client user + */ + int (*vprintf)(Monitor *mon, const char *fmt, va_list ap) + G_GNUC_PRINTF(2, 0); }; struct Monitor { diff --git a/monitor/monitor.c b/monitor/monitor.c index ae36e996e9..1ab04a19fa 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -261,21 +261,18 @@ int monitor_puts(Monitor *mon, const char *str) int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap) { - char *buf; - int n; + MonitorClass *moncls; if (!mon) { return -1; } - if (monitor_is_qmp(mon)) { + moncls = MONITOR_GET_CLASS(mon); + if (!moncls->vprintf) { return -1; } - buf = g_strdup_vprintf(fmt, ap); - n = monitor_puts(mon, buf); - g_free(buf); - return n; + return moncls->vprintf(mon, fmt, ap); } int monitor_printf(Monitor *mon, const char *fmt, ...) -- 2.54.0

This removes the need for using monitor_is_qmp() to check the subclass type, which is an anti-pattern. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- include/monitor/monitor.h | 1 + monitor/monitor-internal.h | 5 +++++ monitor/monitor.c | 15 +++------------ monitor/qmp.c | 20 ++++++++++++++++++++ 4 files changed, 29 insertions(+), 12 deletions(-) diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h index a135b3a590..8cb3db677b 100644 --- a/include/monitor/monitor.h +++ b/include/monitor/monitor.h @@ -3,6 +3,7 @@ #include "block/block.h" #include "qapi/qapi-types-misc.h" +#include "qapi/qapi-emit-events.h" #include "qemu/readline.h" #include "exec/hwaddr.h" #include "qom/object.h" diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 23cef68153..763b5c9625 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -111,6 +111,11 @@ struct MonitorClass { */ int (*vprintf)(Monitor *mon, const char *fmt, va_list ap) G_GNUC_PRINTF(2, 0); + /* + * If non-NULL, the monitor is able to send event + * notifications back to the client + */ + void (*emit_event)(Monitor *mon, QAPIEvent event, QDict *qdict); }; struct Monitor { diff --git a/monitor/monitor.c b/monitor/monitor.c index 1ab04a19fa..93fe542f23 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -345,22 +345,13 @@ static inline QEMUClockType monitor_get_event_clock(void) 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; + MonitorClass *cls = MONITOR_GET_CLASS(mon); + if (cls->emit_event) { + cls->emit_event(mon, event, qdict); } - - qmp_mon = container_of(mon, MonitorQMP, parent_obj); - { - QEMU_LOCK_GUARD(&mon->mon_lock); - if (qmp_mon->commands == &qmp_cap_negotiation_commands) { - continue; - } - } - qmp_send_response(qmp_mon, qdict); } } diff --git a/monitor/qmp.c b/monitor/qmp.c index 6e23f7f4ed..b21dfbe578 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -99,11 +99,17 @@ static void monitor_qmp_set_pretty(Object *obj, bool val, Error **errp) mon->pretty = val; } +static void monitor_qmp_emit_event(Monitor *mon, QAPIEvent event, QDict *qdict); + static void monitor_qmp_class_init(ObjectClass *cls, const void *data) { + MonitorClass *moncls = MONITOR_CLASS(cls); + object_class_property_add_bool(cls, "pretty", monitor_qmp_get_pretty, monitor_qmp_set_pretty); + + moncls->emit_event = monitor_qmp_emit_event; } static void handle_qmp_command(void *opaque, QObject *req, Error *err); @@ -117,6 +123,20 @@ static void monitor_qmp_init(Object *obj) json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL); } +static void monitor_qmp_emit_event(Monitor *mon, QAPIEvent event, QDict *qdict) +{ + MonitorQMP *qmp = MONITOR_QMP(mon); + + WITH_QEMU_LOCK_GUARD(&mon->mon_lock) { + if (qmp->commands == &qmp_cap_negotiation_commands) { + return; + } + } + + qmp_send_response(qmp, qdict); +} + + static bool qmp_oob_enabled(MonitorQMP *mon) { return mon->capab[QMP_CAPABILITY_OOB]; -- 2.54.0

This removes the need for using monitor_is_qmp() to check the subclass type, which is an anti-pattern. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/hmp.c | 16 ++++++++++++++++ monitor/monitor-internal.h | 5 +++++ monitor/monitor.c | 12 +++--------- 3 files changed, 24 insertions(+), 9 deletions(-) diff --git a/monitor/hmp.c b/monitor/hmp.c index 08055839a4..1da9370ead 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -70,6 +70,7 @@ static void monitor_hmp_set_readline(Object *obj, bool val, Error **errp) int monitor_hmp_vprintf(Monitor *mon, const char *fmt, va_list ap) G_GNUC_PRINTF(2, 0); +static void monitor_hmp_accept_input(Monitor *mon); static void monitor_hmp_class_init(ObjectClass *cls, const void *data) { @@ -80,6 +81,7 @@ static void monitor_hmp_class_init(ObjectClass *cls, const void *data) monitor_hmp_set_readline); moncls->vprintf = monitor_hmp_vprintf; + moncls->accept_input = monitor_hmp_accept_input; } static void monitor_hmp_init(Object *obj) @@ -100,6 +102,20 @@ int monitor_hmp_vprintf(Monitor *mon, const char *fmt, va_list ap) return monitor_puts(mon, buf); } +static void monitor_hmp_accept_input(Monitor *mon) +{ + qemu_mutex_lock(&mon->mon_lock); + if (mon->reset_seen) { + MonitorHMP *hmp = MONITOR_HMP(mon); + assert(hmp->rs); + readline_restart(hmp->rs); + qemu_mutex_unlock(&mon->mon_lock); + readline_show_prompt(hmp->rs); + } else { + qemu_mutex_unlock(&mon->mon_lock); + } +} + static void monitor_command_cb(void *opaque, const char *cmdline, void *readline_opaque) { diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 763b5c9625..592f146331 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -116,6 +116,11 @@ struct MonitorClass { * notifications back to the client */ void (*emit_event)(Monitor *mon, QAPIEvent event, QDict *qdict); + /* + * If non-NULL, perform any actions needed to prepare + * the monitor to accept further client input + */ + void (*accept_input)(Monitor *mon); }; struct Monitor { diff --git a/monitor/monitor.c b/monitor/monitor.c index 93fe542f23..4928e5201e 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -575,16 +575,10 @@ int monitor_suspend(Monitor *mon) static void monitor_accept_input(void *opaque) { Monitor *mon = opaque; + MonitorClass *cls = MONITOR_GET_CLASS(mon); - qemu_mutex_lock(&mon->mon_lock); - if (!monitor_is_qmp(mon) && mon->reset_seen) { - MonitorHMP *hmp_mon = container_of(mon, MonitorHMP, parent_obj); - assert(hmp_mon->rs); - readline_restart(hmp_mon->rs); - qemu_mutex_unlock(&mon->mon_lock); - readline_show_prompt(hmp_mon->rs); - } else { - qemu_mutex_unlock(&mon->mon_lock); + if (cls->accept_input) { + cls->accept_input(mon); } qemu_chr_fe_accept_input(&mon->chr); -- 2.54.0

Introducing a virtual "requires_iothread" method allows the code to automatically initialize the I/O thread during object completion. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor-internal.h | 14 +++++++++----- monitor/monitor.c | 22 ++++++++++++---------- monitor/qmp.c | 20 +++++++++++--------- 3 files changed, 32 insertions(+), 24 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 592f146331..efd21b8912 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -121,6 +121,12 @@ struct MonitorClass { * the monitor to accept further client input */ void (*accept_input)(Monitor *mon); + + /* + * If non-NULL and returns true, then an I/O thread + * is required for processing the monitor + */ + bool (*requires_iothread)(const Monitor *mon); }; struct Monitor { @@ -129,7 +135,6 @@ struct Monitor { CharFrontend chr; int suspend_cnt; /* Needs to be accessed atomically */ bool is_qmp; - bool use_io_thread; char *mon_cpu_path; QTAILQ_ENTRY(Monitor) entry; @@ -159,9 +164,8 @@ struct MonitorHMP { bool use_readline; /* * State used only in the thread "owning" the monitor. - * If @use_io_thread, this is @mon_iothread. (This does not actually happen - * in the current state of the code.) - * Else, it's the main thread. + * This is currently always the main thread, since + * HMP does not allow use of the I/O thread at this time. * These members can be safely accessed without locks. */ ReadLineState *rs; @@ -210,7 +214,7 @@ extern QemuMutex monitor_lock; extern MonitorList mon_list; void monitor_complete(Monitor *mon, Error **errp); -void monitor_iothread_init(Monitor *mon); +bool monitor_requires_iothread(const Monitor *mon); int monitor_can_read(void *opaque); void monitor_list_append(Monitor *mon); void monitor_fdsets_cleanup(void); diff --git a/monitor/monitor.c b/monitor/monitor.c index 4928e5201e..a700d747fa 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -159,6 +159,12 @@ bool monitor_cur_is_qmp(void) return cur_mon && monitor_is_qmp(cur_mon); } +bool monitor_requires_iothread(const Monitor *mon) +{ + MonitorClass *cls = MONITOR_GET_CLASS(mon); + return cls->requires_iothread && cls->requires_iothread(mon); +} + /** * Is @mon is using readline? * Note: not all HMP monitors use readline, e.g., gdbserver has a @@ -560,7 +566,7 @@ int monitor_suspend(Monitor *mon) qatomic_inc(&mon->suspend_cnt); - if (mon->use_io_thread) { + if (monitor_requires_iothread(mon)) { /* * Kick I/O thread to make sure this takes effect. It'll be * evaluated again in prepare() of the watch object. @@ -593,7 +599,7 @@ void monitor_resume(Monitor *mon) if (qatomic_dec_fetch(&mon->suspend_cnt) == 0) { AioContext *ctx; - if (mon->use_io_thread) { + if (monitor_requires_iothread(mon)) { ctx = iothread_get_aio_context(mon_iothread); } else { ctx = qemu_get_aio_context(); @@ -631,14 +637,6 @@ void monitor_list_append(Monitor *mon) } } -void monitor_iothread_init(Monitor *mon) -{ - if (!mon_iothread) { - mon_iothread = iothread_create("mon_iothread", &error_abort); - } - mon->use_io_thread = true; -} - void monitor_cleanup(void) { /* @@ -733,6 +731,10 @@ void monitor_complete(Monitor *mon, Error **errp) return; } } + + if (monitor_requires_iothread(mon) && !mon_iothread) { + mon_iothread = iothread_create("mon_iothread", &error_abort); + } } int monitor_new(MonitorOptions *opts, bool allow_hmp, Error **errp) diff --git a/monitor/qmp.c b/monitor/qmp.c index b21dfbe578..95b2c02497 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -100,6 +100,7 @@ static void monitor_qmp_set_pretty(Object *obj, bool val, Error **errp) } static void monitor_qmp_emit_event(Monitor *mon, QAPIEvent event, QDict *qdict); +static bool monitor_qmp_requires_iothread(const Monitor *mon); static void monitor_qmp_class_init(ObjectClass *cls, const void *data) { @@ -110,6 +111,7 @@ static void monitor_qmp_class_init(ObjectClass *cls, const void *data) monitor_qmp_set_pretty); moncls->emit_event = monitor_qmp_emit_event; + moncls->requires_iothread = monitor_qmp_requires_iothread; } static void handle_qmp_command(void *opaque, QObject *req, Error *err); @@ -136,6 +138,11 @@ static void monitor_qmp_emit_event(Monitor *mon, QAPIEvent event, QDict *qdict) qmp_send_response(qmp, qdict); } +static bool monitor_qmp_requires_iothread(const Monitor *mon) +{ + return qemu_chr_has_feature(mon->chr.chr, + QEMU_CHAR_FEATURE_GCONTEXT); +} static bool qmp_oob_enabled(MonitorQMP *mon) { @@ -146,7 +153,8 @@ 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->parent_obj.use_io_thread; + mon->capab_offered[QMP_CAPABILITY_OOB] = + monitor_requires_iothread(MONITOR(mon)); } static void qmp_request_free(QMPRequest *req) @@ -562,7 +570,7 @@ static void monitor_qmp_setup_handlers_bh(void *opaque) MonitorQMP *mon = opaque; GMainContext *context; - assert(mon->parent_obj.use_io_thread); + assert(monitor_requires_iothread(MONITOR(mon))); context = iothread_get_g_main_context(mon_iothread); assert(context); qemu_chr_fe_set_handlers(&mon->parent_obj.chr, monitor_can_read, @@ -597,13 +605,7 @@ void monitor_new_qmp(const char *chardev_id, bool pretty, Error **errp) qemu_chr_fe_set_echo(&mon->parent_obj.chr, true); - /* Note: we run QMP monitor in I/O thread when @chr supports that */ - if (qemu_chr_has_feature(mon->parent_obj.chr.chr, - QEMU_CHAR_FEATURE_GCONTEXT)) { - monitor_iothread_init(&mon->parent_obj); - } - - if (mon->parent_obj.use_io_thread) { + if (monitor_requires_iothread(MONITOR(mon))) { /* * Make sure the old iowatch is gone. It's possible when * e.g. the chardev is in client mode, with wait=on. -- 2.54.0

This eliminates a use of monitor_is_qmp() from the QMP coroutine dispatch path. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/qmp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/monitor/qmp.c b/monitor/qmp.c index 95b2c02497..5cf38c6273 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -277,11 +277,12 @@ static QMPRequest *monitor_qmp_requests_pop_any_with_lock(void) MonitorQMP *qmp_mon; QTAILQ_FOREACH(mon, &mon_list, entry) { - if (!monitor_is_qmp(mon)) { + qmp_mon = MONITOR_QMP( + object_dynamic_cast(OBJECT(mon), TYPE_MONITOR_QMP)); + if (!qmp_mon) { continue; } - qmp_mon = container_of(mon, MonitorQMP, parent_obj); qemu_mutex_lock(&qmp_mon->qmp_queue_lock); req_obj = g_queue_pop_head(qmp_mon->qmp_requests); if (req_obj) { -- 2.54.0

This eliminates a use of monitor_is_qmp() from the error reporting path. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- util/error-report.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/util/error-report.c b/util/error-report.c index f832ad9b6b..f333af9249 100644 --- a/util/error-report.c +++ b/util/error-report.c @@ -231,16 +231,15 @@ char *real_time_iso8601(void) G_GNUC_PRINTF(2, 0) static void vreport(report_type type, const char *fmt, va_list ap) { - Monitor *cur = monitor_cur(); - gchar *timestr; - /* * When current monitor is QMP, messages must go to stderr - * and have prefixes added + * and have prefixes added, so we cast to HMP, leaving 'cur' + * as NULL in QMP case */ - if (monitor_cur_is_qmp()) { - cur = NULL; - } + Monitor *cur = MONITOR( + object_dynamic_cast(OBJECT(monitor_cur()), TYPE_MONITOR_HMP)); + gchar *timestr; + if (!cur) { qemu_flockfile(stderr); } -- 2.54.0

The previous patch dropped the only remaining use of monitor_cur_is_qmp. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- include/monitor/monitor.h | 1 - monitor/monitor.c | 10 ---------- stubs/monitor-core.c | 5 ----- tests/unit/test-util-sockets.c | 1 - tools/qemu-vnc/stubs.c | 5 ----- 5 files changed, 22 deletions(-) diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h index 8cb3db677b..3f730cffee 100644 --- a/include/monitor/monitor.h +++ b/include/monitor/monitor.h @@ -25,7 +25,6 @@ extern QemuOptsList qemu_mon_opts; Monitor *monitor_cur(void); Monitor *monitor_set_cur(Coroutine *co, Monitor *mon); -bool monitor_cur_is_qmp(void); void monitor_init_globals(void); void monitor_init_globals_core(void); diff --git a/monitor/monitor.c b/monitor/monitor.c index a700d747fa..44b1d5ea7f 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -149,16 +149,6 @@ Monitor *monitor_set_cur(Coroutine *co, Monitor *mon) return old_monitor; } -/** - * Is the current monitor, if any, a QMP monitor? - */ -bool monitor_cur_is_qmp(void) -{ - Monitor *cur_mon = monitor_cur(); - - return cur_mon && monitor_is_qmp(cur_mon); -} - bool monitor_requires_iothread(const Monitor *mon) { MonitorClass *cls = MONITOR_GET_CLASS(mon); diff --git a/stubs/monitor-core.c b/stubs/monitor-core.c index 078a5012e9..a7c32297c9 100644 --- a/stubs/monitor-core.c +++ b/stubs/monitor-core.c @@ -7,11 +7,6 @@ Monitor *monitor_cur(void) return NULL; } -bool monitor_cur_is_qmp(void) -{ - return false; -} - Monitor *monitor_set_cur(Coroutine *co, Monitor *mon) { return NULL; diff --git a/tests/unit/test-util-sockets.c b/tests/unit/test-util-sockets.c index b9f2453e29..ee66d727c3 100644 --- a/tests/unit/test-util-sockets.c +++ b/tests/unit/test-util-sockets.c @@ -74,7 +74,6 @@ int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp) Monitor *monitor_cur(void) { return cur_mon; } Monitor *monitor_set_cur(Coroutine *co, Monitor *mon) { abort(); } int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap) { abort(); } -bool monitor_cur_is_qmp(void) { abort(); }; #ifndef _WIN32 static void test_socket_fd_pass_name_good(void) diff --git a/tools/qemu-vnc/stubs.c b/tools/qemu-vnc/stubs.c index a865ce85f0..1c82d8cff4 100644 --- a/tools/qemu-vnc/stubs.c +++ b/tools/qemu-vnc/stubs.c @@ -36,11 +36,6 @@ Monitor *monitor_cur(void) return NULL; } -bool monitor_cur_is_qmp(void) -{ - return false; -} - Monitor *monitor_set_cur(Coroutine *co, Monitor *mon) { return NULL; -- 2.54.0

Rather than asserting monitor_is_qmp(), use a QOM cast via MONITOR_QMP which performs an assert already. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/qmp-cmds-control.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/monitor/qmp-cmds-control.c b/monitor/qmp-cmds-control.c index af6a2a118b..8fe0876a3d 100644 --- a/monitor/qmp-cmds-control.c +++ b/monitor/qmp-cmds-control.c @@ -72,11 +72,7 @@ static bool qmp_caps_accept(MonitorQMP *mon, QMPCapabilityList *list, void qmp_qmp_capabilities(bool has_enable, QMPCapabilityList *enable, Error **errp) { - Monitor *cur_mon = monitor_cur(); - MonitorQMP *mon; - - assert(monitor_is_qmp(cur_mon)); - mon = container_of(cur_mon, MonitorQMP, parent_obj); + MonitorQMP *mon = MONITOR_QMP(monitor_cur()); if (mon->commands == &qmp_commands) { error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND, @@ -122,11 +118,7 @@ static void query_commands_cb(const QmpCommand *cmd, void *opaque) CommandInfoList *qmp_query_commands(Error **errp) { CommandInfoList *list = NULL; - Monitor *cur_mon = monitor_cur(); - MonitorQMP *mon; - - assert(monitor_is_qmp(cur_mon)); - mon = container_of(cur_mon, MonitorQMP, parent_obj); + MonitorQMP *mon = MONITOR_QMP(monitor_cur()); qmp_for_each_command(mon->commands, query_commands_cb, &list); -- 2.54.0

Rather than checking !monitor_is_qmp(), use a dynamic cast to check for HMP. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/monitor/monitor.c b/monitor/monitor.c index 44b1d5ea7f..578aca70d4 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -167,7 +167,7 @@ static inline bool monitor_uses_readline(const MonitorHMP *mon) static inline bool monitor_is_hmp_non_interactive(const Monitor *mon) { - if (monitor_is_qmp(mon)) { + if (!object_dynamic_cast(OBJECT(mon), TYPE_MONITOR_HMP)) { return false; } -- 2.54.0

The previous patch dropped the only remaining use of monitor_is_qmp. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor-internal.h | 9 --------- monitor/monitor.c | 1 - 2 files changed, 10 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index efd21b8912..fe5703af6d 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -134,7 +134,6 @@ struct Monitor { char *chardev_id; CharFrontend chr; int suspend_cnt; /* Needs to be accessed atomically */ - bool is_qmp; char *mon_cpu_path; QTAILQ_ENTRY(Monitor) entry; @@ -197,14 +196,6 @@ struct MonitorQMP { GQueue *qmp_requests; }; -/** - * Is @mon a QMP monitor? - */ -static inline bool monitor_is_qmp(const Monitor *mon) -{ - return mon->is_qmp; -} - typedef QTAILQ_HEAD(MonitorList, Monitor) MonitorList; extern IOThread *mon_iothread; extern Coroutine *qmp_dispatcher_co; diff --git a/monitor/monitor.c b/monitor/monitor.c index 578aca70d4..0cace985f0 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -112,7 +112,6 @@ static void monitor_init(Object *obj) Monitor *mon = MONITOR(obj); qemu_mutex_init(&mon->mon_lock); - mon->is_qmp = !!object_dynamic_cast(obj, TYPE_MONITOR_QMP); mon->outbuf = g_string_new(NULL); } -- 2.54.0

The monitor_is_hmp_non_interactive method is used by monitor_suspend and monitor_resume, to make them a no-op if the HMP does not use readline. There are only a handful of callers of suspend/resume and they can be made to skip the call when readline is not present. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- include/monitor/monitor.h | 2 +- migration/migration-hmp-cmds.c | 5 ++++- monitor/hmp-cmds.c | 5 ++++- monitor/hmp.c | 11 ++++++++--- monitor/monitor.c | 30 +----------------------------- 5 files changed, 18 insertions(+), 35 deletions(-) diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h index 3f730cffee..ffda343585 100644 --- a/include/monitor/monitor.h +++ b/include/monitor/monitor.h @@ -34,7 +34,7 @@ int monitor_new(MonitorOptions *opts, bool allow_hmp, Error **errp); int monitor_new_opts(QemuOpts *opts, Error **errp); void monitor_cleanup(void); -int monitor_suspend(Monitor *mon); +void monitor_suspend(Monitor *mon); void monitor_resume(Monitor *mon); int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp); diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c index 8b385f560e..502ca704da 100644 --- a/migration/migration-hmp-cmds.c +++ b/migration/migration-hmp-cmds.c @@ -19,6 +19,7 @@ #include "monitor/hmp.h" #include "monitor/hmp-completion.h" #include "monitor/monitor.h" +#include "monitor/monitor-internal.h" #include "qapi/error.h" #include "qapi/qapi-commands-migration.h" #include "qapi/qapi-visit-migration.h" @@ -853,12 +854,14 @@ void hmp_migrate(Monitor *mon, const QDict *qdict) if (!detach) { HMPMigrationStatus *status; + MonitorHMP *hmp = MONITOR_HMP(mon); - if (monitor_suspend(mon) < 0) { + if (!hmp->use_readline) { monitor_printf(mon, "terminal does not allow synchronous " "migration, continuing detached\n"); return; } + monitor_suspend(mon); status = g_malloc0(sizeof(*status)); status->mon = mon; diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c index e139caeba9..e9fb8d827a 100644 --- a/monitor/hmp-cmds.c +++ b/monitor/hmp-cmds.c @@ -129,7 +129,10 @@ void hmp_info_version(Monitor *mon, const QDict *qdict) void hmp_quit(Monitor *mon, const QDict *qdict) { - monitor_suspend(mon); + MonitorHMP *hmp = MONITOR_HMP(mon); + if (hmp->use_readline) { + monitor_suspend(mon); + } qmp_quit(NULL); } diff --git a/monitor/hmp.c b/monitor/hmp.c index 1da9370ead..b8cccdcde3 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -1528,13 +1528,16 @@ static void monitor_read(void *opaque, const uint8_t *buf, int size) static void monitor_event(void *opaque, QEMUChrEvent event) { Monitor *mon = opaque; + MonitorHMP *hmp = MONITOR_HMP(mon); switch (event) { case CHR_EVENT_MUX_IN: qemu_mutex_lock(&mon->mon_lock); if (mon->mux_out) { mon->mux_out = 0; - monitor_resume(mon); + if (hmp->use_readline) { + monitor_resume(mon); + } } qemu_mutex_unlock(&mon->mon_lock); break; @@ -1547,7 +1550,9 @@ static void monitor_event(void *opaque, QEMUChrEvent event) } else { monitor_flush_locked(mon); } - monitor_suspend(mon); + if (hmp->use_readline) { + monitor_suspend(mon); + } mon->mux_out = 1; } qemu_mutex_unlock(&mon->mon_lock); @@ -1558,7 +1563,7 @@ static void monitor_event(void *opaque, QEMUChrEvent event) "information\n", QEMU_VERSION); qemu_mutex_lock(&mon->mon_lock); mon->reset_seen = 1; - if (!mon->mux_out) { + if (!mon->mux_out && hmp->use_readline) { /* Suspend-resume forces the prompt to be printed. */ monitor_suspend(mon); monitor_resume(mon); diff --git a/monitor/monitor.c b/monitor/monitor.c index 0cace985f0..c401e23b7b 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -154,25 +154,6 @@ bool monitor_requires_iothread(const Monitor *mon) return cls->requires_iothread && cls->requires_iothread(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 (!object_dynamic_cast(OBJECT(mon), TYPE_MONITOR_HMP)) { - return false; - } - - return !monitor_uses_readline(container_of(mon, MonitorHMP, parent_obj)); -} - static gboolean monitor_unblocked(void *do_not_use, GIOCondition cond, void *opaque) { @@ -547,12 +528,8 @@ static gboolean qapi_event_throttle_equal(const void *a, const void *b) return TRUE; } -int monitor_suspend(Monitor *mon) +void monitor_suspend(Monitor *mon) { - if (monitor_is_hmp_non_interactive(mon)) { - return -ENOTTY; - } - qatomic_inc(&mon->suspend_cnt); if (monitor_requires_iothread(mon)) { @@ -564,7 +541,6 @@ int monitor_suspend(Monitor *mon) } trace_monitor_suspend(mon, 1); - return 0; } static void monitor_accept_input(void *opaque) @@ -581,10 +557,6 @@ static void monitor_accept_input(void *opaque) void monitor_resume(Monitor *mon) { - if (monitor_is_hmp_non_interactive(mon)) { - return; - } - if (qatomic_dec_fetch(&mon->suspend_cnt) == 0) { AioContext *ctx; -- 2.54.0

Implement the user creatable QOM interface and define the monitor-qmp and monitor-hmp types in QAPI. This unlocks the ability to create them on the command line with -object or in HMP/QMP with object_add. For example: $QEMU -chardev stdio,id=monchr0 -object monitor-hmp,id=mon0,chrdev=monchr0 Initially the "prepare_delete" callback is hardcoded to return an error which means -object and object_add can be used, but object_del will fail. Support for deleting monitors will be introduced in subsequent commits. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/hmp.c | 70 ++++++++++++++++++++++++-------------- monitor/monitor-internal.h | 1 - monitor/monitor.c | 14 ++++++-- monitor/qmp.c | 46 +++++++++++++++++-------- qapi/qom.json | 43 +++++++++++++++++++++++ stubs/monitor-internal.c | 1 + system/vl.c | 8 ++++- 7 files changed, 138 insertions(+), 45 deletions(-) diff --git a/monitor/hmp.c b/monitor/hmp.c index b8cccdcde3..2cd508f1ee 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -40,6 +40,7 @@ #include "qemu/base-arch-defs.h" #include "qemu/target-info.h" #include "qemu/units.h" +#include "qom/object_interfaces.h" #include "exec/gdbstub.h" #include "system/block-backend.h" #include "trace.h" @@ -71,10 +72,13 @@ static void monitor_hmp_set_readline(Object *obj, bool val, Error **errp) int monitor_hmp_vprintf(Monitor *mon, const char *fmt, va_list ap) G_GNUC_PRINTF(2, 0); static void monitor_hmp_accept_input(Monitor *mon); +static void monitor_hmp_complete(UserCreatable *uc, Error **errp); +static bool monitor_hmp_prepare_delete(UserCreatable *uc, Error **errp); static void monitor_hmp_class_init(ObjectClass *cls, const void *data) { MonitorClass *moncls = MONITOR_CLASS(cls); + UserCreatableClass *ucc = USER_CREATABLE_CLASS(cls); object_class_property_add_bool(cls, "readline", monitor_hmp_get_readline, @@ -82,6 +86,9 @@ static void monitor_hmp_class_init(ObjectClass *cls, const void *data) moncls->vprintf = monitor_hmp_vprintf; moncls->accept_input = monitor_hmp_accept_input; + + ucc->complete = monitor_hmp_complete; + ucc->prepare_delete = monitor_hmp_prepare_delete; } static void monitor_hmp_init(Object *obj) @@ -1604,42 +1611,53 @@ static void monitor_readline_flush(void *opaque) void monitor_new_hmp(const char *chardev_id, bool use_readline, Error **errp) { - ERRP_GUARD(); - MonitorHMP *mon; static int counter; g_autofree char *id = g_strdup_printf("hmpcompat%d", counter++); - Object *obj = object_new_with_props(TYPE_MONITOR_HMP, - object_get_objects_root(), - id, - errp, - "chardev", chardev_id, - "readline", use_readline ? "yes" : "no", - NULL); - - if (!obj) { - return; - } + object_new_with_props(TYPE_MONITOR_HMP, + object_get_objects_root(), + id, + errp, + "chardev", chardev_id, + "readline", use_readline ? "yes" : "no", + NULL); +} - mon = MONITOR_HMP(obj); +static void monitor_hmp_complete(UserCreatable *uc, Error **errp) +{ + MonitorHMP *mon = MONITOR_HMP(uc); + UserCreatableClass *ucc_parent = + USER_CREATABLE_CLASS( + object_class_get_parent( + OBJECT_CLASS(MONITOR_HMP_GET_CLASS(mon)))); + ERRP_GUARD(); - monitor_complete(MONITOR(mon), errp); + ucc_parent->complete(uc, errp); if (*errp) { - object_unparent(OBJECT(mon)); return; } - if (mon->use_readline) { - mon->rs = readline_init(monitor_readline_printf, - monitor_readline_flush, - mon, - monitor_find_completion); - monitor_read_command(mon, 0); + if (mon->parent_obj.chardev_id) { + if (mon->use_readline) { + mon->rs = readline_init(monitor_readline_printf, + monitor_readline_flush, + mon, + monitor_find_completion); + monitor_read_command(mon, 0); + } + + qemu_chr_fe_set_handlers(&mon->parent_obj.chr, + monitor_can_read, + monitor_read, + monitor_event, NULL, + &mon->parent_obj, NULL, true); + monitor_list_append(&mon->parent_obj); } +} - qemu_chr_fe_set_handlers(&mon->parent_obj.chr, - monitor_can_read, monitor_read, monitor_event, - NULL, &mon->parent_obj, NULL, true); - monitor_list_append(&mon->parent_obj); +static bool monitor_hmp_prepare_delete(UserCreatable *uc, Error **errp) +{ + error_setg(errp, "Deleting HMP monitors is not supported"); + return false; } /** diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index fe5703af6d..012d442a20 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -204,7 +204,6 @@ extern QmpCommandList qmp_commands, qmp_cap_negotiation_commands; extern QemuMutex monitor_lock; extern MonitorList mon_list; -void monitor_complete(Monitor *mon, Error **errp); bool monitor_requires_iothread(const Monitor *mon); int monitor_can_read(void *opaque); void monitor_list_append(Monitor *mon); diff --git a/monitor/monitor.c b/monitor/monitor.c index c401e23b7b..9257dae0be 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -29,6 +29,7 @@ #include "qapi/qapi-emit-events.h" #include "qapi/qapi-visit-control.h" #include "qobject/qdict.h" +#include "qom/object_interfaces.h" #include "qemu/error-report.h" #include "qemu/option.h" #include "system/qtest.h" @@ -73,7 +74,8 @@ static GHashTable *coroutine_mon; /* Maps Coroutine* to Monitor* */ MonitorList mon_list; static bool monitor_destroyed; -OBJECT_DEFINE_TYPE(Monitor, monitor, MONITOR, OBJECT); +OBJECT_DEFINE_TYPE_EXTENDED(Monitor, monitor, MONITOR, OBJECT, true, + { TYPE_USER_CREATABLE }, {}); static void monitor_finalize(Object *obj) { @@ -100,11 +102,17 @@ static void monitor_set_chardev_id(Object *obj, const char *str, Error **errp) mon->chardev_id = g_strdup(str); } +static void monitor_complete(UserCreatable *uc, Error **errp); + static void monitor_class_init(ObjectClass *cls, const void *data) { + UserCreatableClass *ucc = USER_CREATABLE_CLASS(cls); + object_class_property_add_str(cls, "chardev", monitor_get_chardev_id, monitor_set_chardev_id); + + ucc->complete = monitor_complete; } static void monitor_init(Object *obj) @@ -679,8 +687,10 @@ void monitor_init_globals(void) aio_co_schedule(iohandler_get_aio_context(), qmp_dispatcher_co); } -void monitor_complete(Monitor *mon, Error **errp) +static void monitor_complete(UserCreatable *uc, Error **errp) { + Monitor *mon = MONITOR(uc); + if (mon->chardev_id) { Chardev *chr = qemu_chr_find(mon->chardev_id); if (chr == NULL) { diff --git a/monitor/qmp.c b/monitor/qmp.c index 5cf38c6273..ff39b8cda4 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -31,6 +31,7 @@ #include "qobject/qdict.h" #include "qobject/qjson.h" #include "qobject/qlist.h" +#include "qom/object_interfaces.h" #include "trace.h" /* @@ -101,10 +102,13 @@ static void monitor_qmp_set_pretty(Object *obj, bool val, Error **errp) static void monitor_qmp_emit_event(Monitor *mon, QAPIEvent event, QDict *qdict); static bool monitor_qmp_requires_iothread(const Monitor *mon); +static void monitor_qmp_complete(UserCreatable *uc, Error **errp); +static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp); static void monitor_qmp_class_init(ObjectClass *cls, const void *data) { MonitorClass *moncls = MONITOR_CLASS(cls); + UserCreatableClass *ucc = USER_CREATABLE_CLASS(cls); object_class_property_add_bool(cls, "pretty", monitor_qmp_get_pretty, @@ -112,6 +116,9 @@ static void monitor_qmp_class_init(ObjectClass *cls, const void *data) moncls->emit_event = monitor_qmp_emit_event; moncls->requires_iothread = monitor_qmp_requires_iothread; + + ucc->complete = monitor_qmp_complete; + ucc->prepare_delete = monitor_qmp_prepare_delete; } static void handle_qmp_command(void *opaque, QObject *req, Error *err); @@ -582,25 +589,28 @@ static void monitor_qmp_setup_handlers_bh(void *opaque) void monitor_new_qmp(const char *chardev_id, bool pretty, Error **errp) { - MonitorQMP *mon; static int counter; g_autofree char *id = g_strdup_printf("qmpcompat%d", counter++); - Object *obj = object_new_with_props(TYPE_MONITOR_QMP, - object_get_objects_root(), - id, - errp, - "chardev", chardev_id, - "pretty", pretty ? "yes" : "no", - NULL); - - if (!obj) { - return; - } + object_new_with_props(TYPE_MONITOR_QMP, + object_get_objects_root(), + id, + errp, + "chardev", chardev_id, + "pretty", pretty ? "yes" : "no", + NULL); +} - mon = MONITOR_QMP(obj); - monitor_complete(MONITOR(mon), errp); +static void monitor_qmp_complete(UserCreatable *uc, Error **errp) +{ + MonitorQMP *mon = MONITOR_QMP(uc); + UserCreatableClass *ucc_parent = + USER_CREATABLE_CLASS( + object_class_get_parent( + OBJECT_CLASS(MONITOR_QMP_GET_CLASS(mon)))); + ERRP_GUARD(); + + ucc_parent->complete(uc, errp); if (*errp) { - object_unparent(OBJECT(mon)); return; } @@ -632,3 +642,9 @@ void monitor_new_qmp(const char *chardev_id, bool pretty, Error **errp) monitor_list_append(&mon->parent_obj); } } + +static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp) +{ + error_setg(errp, "Deleting QMP monitors is not supported"); + return false; +} diff --git a/qapi/qom.json b/qapi/qom.json index dd45ac1087..6ed510858e 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -1187,6 +1187,45 @@ 'data': { '*cpu-affinity': ['uint16'], '*node-affinity': ['uint16'] } } +## +# @MonitorProperties: +# +# Properties for all monitors +# +# @chardev: ID of the character device providing the monitor transport +# +# Since: 11.1 +## +{ 'struct': 'MonitorProperties', + 'data': { 'chardev': 'str' }} + +## +# @MonitorHMPProperties: +# +# Properties for the HMP monitor +# +# @readline: whether to enable readline for interactive command +# usage (default: enabled) +# +# Since: 11.1 +## +{ 'struct': 'MonitorHMPProperties', + 'base': 'MonitorProperties', + 'data': { '*readline': 'bool' } } + +## +# @MonitorQMPProperties: +# +# Properties for the QMP monitor +# +# @pretty: whether to pretty print JSON responses (default: disabled) +# +# Since: 11.1 +## +{ 'struct': 'MonitorQMPProperties', + 'base': 'MonitorProperties', + 'data': { '*pretty': 'bool' } } + ## # @ObjectType: # @@ -1237,6 +1276,8 @@ 'memory-backend-ram', { 'name': 'memory-backend-shm', 'if': 'CONFIG_POSIX' }, + 'monitor-hmp', + 'monitor-qmp', 'pef-guest', { 'name': 'pr-manager-helper', 'if': 'CONFIG_LINUX' }, @@ -1315,6 +1356,8 @@ 'memory-backend-ram': 'MemoryBackendProperties', 'memory-backend-shm': { 'type': 'MemoryBackendShmProperties', 'if': 'CONFIG_POSIX' }, + 'monitor-hmp': {'type': 'MonitorHMPProperties' }, + 'monitor-qmp': {'type': 'MonitorQMPProperties' }, 'pr-manager-helper': { 'type': 'PrManagerHelperProperties', 'if': 'CONFIG_LINUX' }, 'qtest': 'QtestProperties', diff --git a/stubs/monitor-internal.c b/stubs/monitor-internal.c index 51db7588b9..59ccc4b35c 100644 --- a/stubs/monitor-internal.c +++ b/stubs/monitor-internal.c @@ -10,4 +10,5 @@ int monitor_get_fd(Monitor *mon, const char *name, Error **errp) void monitor_new_hmp(const char *chardev_id, bool use_readline, Error **errp) { + g_assert_not_reached(); } diff --git a/system/vl.c b/system/vl.c index 21ef2dac51..86f09a8b5c 100644 --- a/system/vl.c +++ b/system/vl.c @@ -1829,6 +1829,10 @@ static void object_option_add_visitor(Visitor *v) { ObjectOption *opt = g_new0(ObjectOption, 1); visit_type_ObjectOptions(v, NULL, &opt->opts, &error_fatal); + if (opt->opts->qom_type == OBJECT_TYPE_MONITOR_HMP || + opt->opts->qom_type == OBJECT_TYPE_MONITOR_QMP) { + default_monitor = 0; + } QTAILQ_INSERT_TAIL(&object_opts, opt, next); } @@ -1970,7 +1974,9 @@ static bool object_create_early(const char *type) /* Reason: property "chardev" */ if (g_str_equal(type, "rng-egd") || - g_str_equal(type, "qtest")) { + g_str_equal(type, "qtest") || + g_str_equal(type, "monitor-hmp") || + g_str_equal(type, "monitor-qmp")) { return false; } -- 2.54.0

Add new docs for the `-object monitor-hmp` and `-object monitor-qmp` options, updating `-mon` to state that it is legacy syntax sugar for the new `-object` args. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- qemu-options.hx | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/qemu-options.hx b/qemu-options.hx index 96ae41f787..031417b79d 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4959,6 +4959,16 @@ SRST -mon chardev=mon1,mode=control,pretty=on enables the QMP monitor on localhost port 4444 with pretty-printing. + + The use of ``-mon mode=readline`` is historical syntax sugar + for the new ``-object monitor-hmp`` option, each use of which + creates an object with the ID ``hmpcompatNNN`` where ``NNN`` is + a counter starting from 0. + + The use of ``-mon mode=control`` is historical syntax sugar + for the new ``-object monitor-qmp`` option, each use of which + creates an object with the ID ``qmpcompatNNN`` where ``NNN`` is + a counter starting from 0. ERST DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ @@ -5709,6 +5719,34 @@ SRST they are specified. Note that the 'id' property must be set. These objects are placed in the '/objects' path. + ``-object monitor-hmp,id=id,chardev=chardv_id,readline=on|off`` + Set up a monitor running the Human Monitor Protocol, + connected to the chardev ``chrid``. + + The ``id`` parameter is a unique ID that can be used + to dynamically delete the monitor at runtime. + + The ``readline`` parameter, which defaults to ``on``, + controls whether the monitor provides interactive + prompts + + ``-object monitor-qmp,id=id,chardev=chardev_id,pretty=on|off`` + Set up a monitor running the QEMU Monitor Protocol, + connected to the chardev ``chrid``. + + The ``id`` parameter is a unique ID that can be used + to dynamically delete the monitor at runtime. Note + that monitors created using the historical syntax + will be allocated IDs following the pattern ``monNN``. + Mixing ``-object`` with the historical monitor syntax is + discouraged. + + The ``pretty`` parameter, which defaults to ``off``, + controls whether the monitor responses are pretty + printed as multi-line indented JSON, as opposed to + constrained to a single line without extraneous + whitespace. + ``-object memory-backend-file,id=id,size=size,mem-path=dir,share=on|off,discard-data=on|off,merge=on|off,dump=on|off,prealloc=on|off,host-nodes=host-nodes,policy=default|preferred|bind|interleave,align=align,offset=offset,readonly=on|off,rom=on|off|auto`` Creates a memory file backend object, which can be used to back the guest RAM with huge pages. -- 2.54.0

From: Christian Brauner <brauner@kernel.org> Convert monitor_accept_input from a oneshot BH (aio_bh_schedule_oneshot) to a persistent BH (aio_bh_new + qemu_bh_schedule). Oneshot BHs cannot be cancelled, so monitor_resume() racing with destruction would schedule a callback against memory that monitor_qmp_destroy() is about to free. A persistent BH can be deleted during destruction, cancelling any pending schedule. Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> [DB: extracted oneshot BH conversion from larger commit] Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor-internal.h | 2 +- monitor/monitor.c | 25 ++++++++++++++----------- 2 files changed, 15 insertions(+), 12 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 012d442a20..a82e1aacb6 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -134,7 +134,7 @@ struct Monitor { char *chardev_id; CharFrontend chr; int suspend_cnt; /* Needs to be accessed atomically */ - + QEMUBH *accept_input_bh; /* persistent BH for monitor_accept_input */ char *mon_cpu_path; QTAILQ_ENTRY(Monitor) entry; diff --git a/monitor/monitor.c b/monitor/monitor.c index 9257dae0be..19a119fc71 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -81,6 +81,9 @@ static void monitor_finalize(Object *obj) { Monitor *mon = MONITOR(obj); + if (mon->accept_input_bh) { + qemu_bh_delete(mon->accept_input_bh); + } g_free(mon->chardev_id); g_free(mon->mon_cpu_path); qemu_chr_fe_deinit(&mon->chr, false); @@ -566,15 +569,7 @@ static void monitor_accept_input(void *opaque) void monitor_resume(Monitor *mon) { if (qatomic_dec_fetch(&mon->suspend_cnt) == 0) { - AioContext *ctx; - - if (monitor_requires_iothread(mon)) { - ctx = iothread_get_aio_context(mon_iothread); - } else { - ctx = qemu_get_aio_context(); - } - - aio_bh_schedule_oneshot(ctx, monitor_accept_input, mon); + qemu_bh_schedule(mon->accept_input_bh); } trace_monitor_suspend(mon, -1); @@ -690,6 +685,7 @@ void monitor_init_globals(void) static void monitor_complete(UserCreatable *uc, Error **errp) { Monitor *mon = MONITOR(uc); + AioContext *ctx; if (mon->chardev_id) { Chardev *chr = qemu_chr_find(mon->chardev_id); @@ -703,9 +699,16 @@ static void monitor_complete(UserCreatable *uc, Error **errp) } } - if (monitor_requires_iothread(mon) && !mon_iothread) { - mon_iothread = iothread_create("mon_iothread", &error_abort); + if (monitor_requires_iothread(mon)) { + if (!mon_iothread) { + mon_iothread = iothread_create("mon_iothread", &error_abort); + } + + ctx = iothread_get_aio_context(mon_iothread); + } else { + ctx = qemu_get_aio_context(); } + mon->accept_input_bh = aio_bh_new(ctx, monitor_accept_input, mon); } int monitor_new(MonitorOptions *opts, bool allow_hmp, Error **errp) -- 2.54.0

From: Christian Brauner <brauner@kernel.org> If an 'object_del' command for a QMP monitor arrives targetting the current monitor, reject this request. If the current monitor is deleted, it will be impossible to send any reply and the client won't be able to remove the corresponding chardev backend. Note, it is not possible to rely on checking monitor_cur() because if 'object_del' is called via human-monitor-command, monitor_cur() will reflect the temporary HMP, not the QMP target that needs to be checked. Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> [DB: extracted monitor tracking from larger commit; added logic to monitor_qmp_prepare_delete to reject request] Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/qmp.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/monitor/qmp.c b/monitor/qmp.c index ff39b8cda4..7d80a9bd57 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -72,6 +72,9 @@ typedef struct QMPRequest QMPRequest; QmpCommandList qmp_commands, qmp_cap_negotiation_commands; +/* Monitor being serviced by the dispatcher. Protected by BQL. */ +static MonitorQMP *qmp_dispatcher_current_mon; + OBJECT_DEFINE_TYPE(MonitorQMP, monitor_qmp, MONITOR_QMP, MONITOR); static void monitor_qmp_cleanup_req_queue_locked(MonitorQMP *mon); @@ -369,6 +372,7 @@ void coroutine_fn monitor_qmp_dispatcher_co(void *data) */ mon = req_obj->mon; + qmp_dispatcher_current_mon = mon; /* * We need to resume the monitor if handle_qmp_command() @@ -429,6 +433,7 @@ void coroutine_fn monitor_qmp_dispatcher_co(void *data) } qmp_request_free(req_obj); + qmp_dispatcher_current_mon = NULL; } qatomic_set(&qmp_dispatcher_co, NULL); } @@ -573,6 +578,11 @@ static void monitor_qmp_event(void *opaque, QEMUChrEvent event) } } +static bool monitor_qmp_dispatcher_is_servicing(MonitorQMP *mon) +{ + return qmp_dispatcher_current_mon == mon; +} + static void monitor_qmp_setup_handlers_bh(void *opaque) { MonitorQMP *mon = opaque; @@ -645,6 +655,13 @@ static void monitor_qmp_complete(UserCreatable *uc, Error **errp) static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp) { + MonitorQMP *qmp = MONITOR_QMP(uc); + + if (monitor_qmp_dispatcher_is_servicing(qmp)) { + error_setg(errp, "Cannot delete the current QMP monitor"); + return false; + } + error_setg(errp, "Deleting QMP monitors is not supported"); return false; } -- 2.54.0

From: Christian Brauner <brauner@kernel.org> The monitor_accept_input API is called from a bottom half, and will invoke qemu_chr_fe_accept_input(). When a following patch introduces the ability to delete monitors, it will be neccesary to delete the bottom half. Protecting the call to qemu_chr_fe_accept_input with the monitor lock will allow for synchronization with the deletion process. Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> [DB: extracted from a larger commit and refactored to apply to the new monitor class structure] Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/hmp.c | 2 ++ monitor/monitor.c | 6 +----- monitor/qmp.c | 9 +++++++++ 3 files changed, 12 insertions(+), 5 deletions(-) diff --git a/monitor/hmp.c b/monitor/hmp.c index 2cd508f1ee..7b084c6ff8 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -116,9 +116,11 @@ static void monitor_hmp_accept_input(Monitor *mon) MonitorHMP *hmp = MONITOR_HMP(mon); assert(hmp->rs); readline_restart(hmp->rs); + qemu_chr_fe_accept_input(&mon->chr); qemu_mutex_unlock(&mon->mon_lock); readline_show_prompt(hmp->rs); } else { + qemu_chr_fe_accept_input(&mon->chr); qemu_mutex_unlock(&mon->mon_lock); } } diff --git a/monitor/monitor.c b/monitor/monitor.c index 19a119fc71..909f4f6052 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -559,11 +559,7 @@ static void monitor_accept_input(void *opaque) Monitor *mon = opaque; MonitorClass *cls = MONITOR_GET_CLASS(mon); - if (cls->accept_input) { - cls->accept_input(mon); - } - - qemu_chr_fe_accept_input(&mon->chr); + cls->accept_input(mon); } void monitor_resume(Monitor *mon) diff --git a/monitor/qmp.c b/monitor/qmp.c index 7d80a9bd57..3f3d5b9d1c 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -107,6 +107,7 @@ static void monitor_qmp_emit_event(Monitor *mon, QAPIEvent event, QDict *qdict); static bool monitor_qmp_requires_iothread(const Monitor *mon); static void monitor_qmp_complete(UserCreatable *uc, Error **errp); static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp); +static void monitor_qmp_accept_input(Monitor *mon); static void monitor_qmp_class_init(ObjectClass *cls, const void *data) { @@ -119,6 +120,7 @@ static void monitor_qmp_class_init(ObjectClass *cls, const void *data) moncls->emit_event = monitor_qmp_emit_event; moncls->requires_iothread = monitor_qmp_requires_iothread; + moncls->accept_input = monitor_qmp_accept_input; ucc->complete = monitor_qmp_complete; ucc->prepare_delete = monitor_qmp_prepare_delete; @@ -665,3 +667,10 @@ static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp) error_setg(errp, "Deleting QMP monitors is not supported"); return false; } + +static void monitor_qmp_accept_input(Monitor *mon) +{ + WITH_QEMU_LOCK_GUARD(&mon->mon_lock) { + qemu_chr_fe_accept_input(&mon->chr); + } +} -- 2.54.0

From: Christian Brauner <brauner@kernel.org> The removal sequence is: 1. Mark dead and remove from mon_list under monitor_lock. This must happen before disconnecting chardev handlers to prevent event broadcast from calling monitor_flush_locked() after the gcontext reset, which would create an out_watch on the wrong GMainContext (see monitor_cancel_out_watch()). 2. Cancel any pending out_watch while gcontext still points to the correct context. 3. Disconnect chardev handlers, passing context=NULL and close the connection. 4. Drain pending requests from any in-flight monitor_qmp_read(). 5. Destroy the monitor object Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> [DB: extracted from a larger commit and refactored to apply to the new monitor class structure. Remove 'self delete' feature which requires complex special-case code] Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor-internal.h | 3 +++ monitor/monitor.c | 22 ++++++++++++++++ monitor/qmp.c | 53 ++++++++++++++++++++++++++++++++++++-- 3 files changed, 76 insertions(+), 2 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index a82e1aacb6..2e8e5ec721 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -134,6 +134,7 @@ struct Monitor { char *chardev_id; CharFrontend chr; int suspend_cnt; /* Needs to be accessed atomically */ + bool dead; /* awaiting drain after monitor-remove */ QEMUBH *accept_input_bh; /* persistent BH for monitor_accept_input */ char *mon_cpu_path; QTAILQ_ENTRY(Monitor) entry; @@ -178,6 +179,7 @@ struct MonitorQMP { Monitor parent_obj; JSONMessageParser parser; bool pretty; + bool setup_pending; /* iothread BH has not yet set up chardev handlers */ /* * When a client connects, we're in capabilities negotiation mode. * @commands is &qmp_cap_negotiation_commands then. When command @@ -206,6 +208,7 @@ extern MonitorList mon_list; bool monitor_requires_iothread(const Monitor *mon); int monitor_can_read(void *opaque); +void monitor_cancel_out_watch(Monitor *mon); void monitor_list_append(Monitor *mon); void monitor_fdsets_cleanup(void); int monitor_set_cpu(Monitor *mon, int cpu_index); diff --git a/monitor/monitor.c b/monitor/monitor.c index 909f4f6052..6017d486af 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -176,6 +176,28 @@ static gboolean monitor_unblocked(void *do_not_use, GIOCondition cond, return G_SOURCE_REMOVE; } +/* Cancel a pending out_watch GSource. Caller must hold mon_lock. */ +void monitor_cancel_out_watch(Monitor *mon) +{ + if (mon->out_watch) { + GMainContext *ctx = NULL; + GSource *src; + + if (monitor_requires_iothread(mon)) { + ctx = iothread_get_g_main_context(mon_iothread); + } + src = g_main_context_find_source_by_id(ctx, mon->out_watch); + if (!src && ctx) { + /* Handler disconnect may have reset gcontext to NULL. */ + src = g_main_context_find_source_by_id(NULL, mon->out_watch); + } + if (src) { + g_source_destroy(src); + } + mon->out_watch = 0; + } +} + /* Caller must hold mon->mon_lock */ void monitor_flush_locked(Monitor *mon) { diff --git a/monitor/qmp.c b/monitor/qmp.c index 3f3d5b9d1c..d471428488 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -184,6 +184,12 @@ static void monitor_qmp_cleanup_req_queue_locked(MonitorQMP *mon) } } +static void monitor_qmp_drain_queue(MonitorQMP *mon) +{ + QEMU_LOCK_GUARD(&mon->qmp_queue_lock); + monitor_qmp_cleanup_req_queue_locked(mon); +} + static void monitor_qmp_cleanup_queue_and_resume(MonitorQMP *mon) { QEMU_LOCK_GUARD(&mon->qmp_queue_lock); @@ -655,8 +661,14 @@ static void monitor_qmp_complete(UserCreatable *uc, Error **errp) } } +static void monitor_qmp_iothread_quiesce(void *opaque) +{ + /* No-op: synchronization point only */ +} + static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp) { + Monitor *mon = MONITOR(uc); MonitorQMP *qmp = MONITOR_QMP(uc); if (monitor_qmp_dispatcher_is_servicing(qmp)) { @@ -664,8 +676,45 @@ static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp) return false; } - error_setg(errp, "Deleting QMP monitors is not supported"); - return false; + if (qatomic_read(&qmp->setup_pending)) { + error_setg(errp, "monitor is still initializing"); + return false; + } + + /* Remove from mon_list before chardev disconnect. */ + WITH_QEMU_LOCK_GUARD(&monitor_lock) { + mon->dead = true; + QTAILQ_REMOVE(&mon_list, mon, entry); + } + + /* Cancel out_watch while gcontext still points to the right ctx. */ + WITH_QEMU_LOCK_GUARD(&mon->mon_lock) { + monitor_cancel_out_watch(mon); + } + + qemu_chr_fe_set_handlers(&mon->chr, NULL, NULL, NULL, NULL, + NULL, NULL, true); + + /* Drain requests from any in-flight monitor_qmp_read(). */ + monitor_qmp_drain_queue(qmp); + + WITH_QEMU_LOCK_GUARD(&mon->mon_lock) { + /* Disable flushes before cancel -- gcontext is already wrong. */ + qemu_chr_fe_set_open(&mon->chr, false); + monitor_cancel_out_watch(mon); + } + + /* Synchronize with in-flight iothread callbacks. */ + if (monitor_requires_iothread(mon)) { + aio_wait_bh_oneshot(iothread_get_aio_context(mon_iothread), + monitor_qmp_iothread_quiesce, NULL); + } + + /* Catch requests from a racing monitor_qmp_read(). */ + monitor_qmp_drain_queue(qmp); + monitor_fdsets_cleanup(); + + return true; } static void monitor_qmp_accept_input(Monitor *mon) -- 2.54.0

From: Christian Brauner <brauner@kernel.org> Test the object-add/object-del QMP commands with the monitor-qmp object type. - Basic lifecycle: chardev-add -> object-add -> object-del -> chardev-remove - Error: object-add with nonexistent chardev - Error: second monitor on same chardev (chardev already in use) - Removal of CLI-created QMP monitor succeeds - Error: object-remove on HMP monitor - Re-add after remove: same id and chardev reusable after removal Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> [DB: modified to use object-add/object-del, removing redundant scenarios already handled by object-add/del code] Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- tests/qtest/qmp-test.c | 174 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) diff --git a/tests/qtest/qmp-test.c b/tests/qtest/qmp-test.c index edf0886787..3a325a04e0 100644 --- a/tests/qtest/qmp-test.c +++ b/tests/qtest/qmp-test.c @@ -337,6 +337,174 @@ static void test_qmp_missing_any_arg(void) qtest_quit(qts); } +static void test_qmp_monitor_add_remove(void) +{ + QTestState *qts; + QDict *resp; + + qts = qtest_init(common_args); + + /* Create a null chardev for the dynamic monitor */ + resp = qtest_qmp(qts, + "{'execute': 'chardev-add'," + " 'arguments': {'id': 'monitor-chardev'," + " 'backend': {'type': 'null'," + " 'data': {}}}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + /* Add a dynamic monitor */ + resp = qtest_qmp(qts, + "{'execute': 'object-add'," + " 'arguments': {'qom-type': 'monitor-qmp'," + " 'id': 'dyn-mon'," + " 'chardev': 'monitor-chardev'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + /* Remove the dynamic monitor */ + resp = qtest_qmp(qts, + "{'execute': 'object-del'," + " 'arguments': {'id': 'dyn-mon'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + /* Add again after remove -- same id and chardev should work */ + resp = qtest_qmp(qts, + "{'execute': 'object-add'," + " 'arguments': {'qom-type': 'monitor-qmp'," + " 'id': 'dyn-mon'," + " 'chardev': 'monitor-chardev'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + /* Clean up */ + resp = qtest_qmp(qts, + "{'execute': 'object-del'," + " 'arguments': {'id': 'dyn-mon'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + resp = qtest_qmp(qts, + "{'execute': 'chardev-remove'," + " 'arguments': {'id': 'monitor-chardev'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + qtest_quit(qts); +} + +static void test_qmp_monitor_error_paths(void) +{ + QTestState *qts; + QDict *resp; + + qts = qtest_init(common_args); + + /* Error: chardev does not exist */ + resp = qtest_qmp(qts, + "{'execute': 'object-add'," + " 'arguments': {'qom-type': 'monitor-qmp'," + " 'id': 'bad-mon'," + " 'chardev': 'nonexistent'}}"); + qmp_expect_error_and_unref(resp, "GenericError"); + + qtest_quit(qts); +} + +static void test_qmp_monitor_chardev_in_use(void) +{ + QTestState *qts; + QDict *resp; + + qts = qtest_init(common_args); + + /* Create a null chardev */ + resp = qtest_qmp(qts, + "{'execute': 'chardev-add'," + " 'arguments': {'id': 'shared-chr'," + " 'backend': {'type': 'null'," + " 'data': {}}}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + /* Attach first monitor */ + resp = qtest_qmp(qts, + "{'execute': 'object-add'," + " 'arguments': {'qom-type': 'monitor-qmp'," + " 'id': 'mon-1'," + " 'chardev': 'shared-chr'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + /* Error: second monitor on the same chardev */ + resp = qtest_qmp(qts, + "{'execute': 'object-add'," + " 'arguments': {'qom-type': 'monitor-qmp'," + " 'id': 'mon-2'," + " 'chardev': 'shared-chr'}}"); + qmp_expect_error_and_unref(resp, "GenericError"); + + /* Clean up */ + resp = qtest_qmp(qts, + "{'execute': 'object-del'," + " 'arguments': {'id': 'mon-1'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + resp = qtest_qmp(qts, + "{'execute': 'chardev-remove'," + " 'arguments': {'id': 'shared-chr'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + qtest_quit(qts); +} + +static void test_qmp_monitor_remove_cli(void) +{ + QTestState *qts; + QDict *resp; + + /* Launch with a named CLI monitor on a null chardev */ + qts = qtest_initf("%s -chardev null,id=cli-chr" + " -object monitor-qmp,id=cli-mon,chardev=cli-chr", + common_args); + + /* CLI-created QMP monitors can be removed */ + resp = qtest_qmp(qts, + "{'execute': 'object-del'," + " 'arguments': {'id': 'cli-mon'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + resp = qtest_qmp(qts, + "{'execute': 'chardev-remove'," + " 'arguments': {'id': 'cli-chr'}}"); + g_assert(qdict_haskey(resp, "return")); + qobject_unref(resp); + + qtest_quit(qts); +} + +static void test_qmp_monitor_remove_hmp(void) +{ + QTestState *qts; + QDict *resp; + + qts = qtest_initf("%s -chardev null,id=hmp-chr" + " -object monitor-hmp,id=hmp-mon,chardev=hmp-chr", + common_args); + + /* Error: object_del must reject HMP monitors */ + resp = qtest_qmp(qts, + "{'execute': 'object-del'," + " 'arguments': {'id': 'hmp-mon'}}"); + qmp_expect_error_and_unref(resp, "GenericError"); + + qtest_quit(qts); +} + int main(int argc, char *argv[]) { g_test_init(&argc, &argv, NULL); @@ -348,6 +516,12 @@ int main(int argc, char *argv[]) #endif qtest_add_func("qmp/preconfig", test_qmp_preconfig); qtest_add_func("qmp/missing-any-arg", test_qmp_missing_any_arg); + qtest_add_func("qmp/monitor-add-remove", test_qmp_monitor_add_remove); + qtest_add_func("qmp/monitor-error-paths", test_qmp_monitor_error_paths); + qtest_add_func("qmp/monitor-chardev-in-use", + test_qmp_monitor_chardev_in_use); + qtest_add_func("qmp/monitor-remove-cli", test_qmp_monitor_remove_cli); + qtest_add_func("qmp/monitor-remove-hmp", test_qmp_monitor_remove_hmp); return g_test_run(); } -- 2.54.0

From: Christian Brauner <brauner@kernel.org> Add functional tests that exercise dynamic monitor hotplug with real socket connections: - Hotplug cycle: chardev-add a unix socket, object-add, connect to the socket, receive the QMP greeting, negotiate capabilities, send query-version, disconnect, remove the monitor and chardev, then repeat the entire cycle a second time to verify cleanup and reuse. - Self-removal: a dynamically-added monitor sends object-del targeting itself, verifying that the request is rejected - Large response: send query-qmp-schema on a dynamic monitor to exercise the output buffer flush path with a large response payload. - Events after negotiation: trigger STOP/RESUME events via the main monitor and verify they are delivered on the dynamic monitor. This complements the qtest unit tests by verifying that a real QMP client can connect to a dynamically-added monitor and exchange messages. Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> [DB: modified to use object-add/object-del; adjust self-removal test to validate rejection of request] Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- MAINTAINERS | 1 + tests/functional/generic/meson.build | 1 + .../generic/test_monitor_hotplug.py | 168 ++++++++++++++++++ 3 files changed, 170 insertions(+) create mode 100755 tests/functional/generic/test_monitor_hotplug.py diff --git a/MAINTAINERS b/MAINTAINERS index 748ec77beb..86bb043674 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3615,6 +3615,7 @@ F: docs/interop/*qmp-* F: scripts/qmp/ F: tests/qtest/qmp-test.c F: tests/qtest/qmp-cmd-test.c +F: tests/functional/generic/test_monitor_hotplug.py T: git https://repo.or.cz/qemu/armbru.git qapi-next qtest diff --git a/tests/functional/generic/meson.build b/tests/functional/generic/meson.build index 09763c5d22..c94105c62e 100644 --- a/tests/functional/generic/meson.build +++ b/tests/functional/generic/meson.build @@ -4,6 +4,7 @@ tests_generic_system = [ 'empty_cpu_model', 'info_usernet', 'linters', + 'monitor_hotplug', 'version', 'vnc', ] diff --git a/tests/functional/generic/test_monitor_hotplug.py b/tests/functional/generic/test_monitor_hotplug.py new file mode 100755 index 0000000000..5d8a159eb0 --- /dev/null +++ b/tests/functional/generic/test_monitor_hotplug.py @@ -0,0 +1,168 @@ +#!/usr/bin/env python3 +# +# SPDX-License-Identifier: GPL-2.0-or-later +# +# Functional test for dynamic QMP monitor hotplug +# +# Copyright (c) 2026 Christian Brauner + +import os + +from qemu_test import QemuSystemTest + +from qemu.qmp.legacy import QEMUMonitorProtocol + + +class MonitorHotplug(QemuSystemTest): + + def setUp(self): + super().setUp() + sock_dir = self.socket_dir() + self._sock_path = os.path.join(sock_dir.name, 'hotplug.sock') + + def _add_monitor(self): + """Create a chardev + monitor and return the socket path.""" + sock = self._sock_path + self.vm.cmd('chardev-add', id='hotplug-chr', backend={ + 'type': 'socket', + 'data': { + 'addr': { + 'type': 'unix', + 'data': {'path': sock} + }, + 'server': True, + 'wait': False, + } + }) + self.vm.cmd('object-add', id='hotplug-mon', + qom_type='monitor-qmp', + chardev='hotplug-chr') + return sock + + def _remove_monitor(self): + """Remove the monitor + chardev.""" + self.vm.cmd('object-del', id='hotplug-mon') + self.vm.cmd('chardev-remove', id='hotplug-chr') + + def _connect_and_handshake(self, sock_path): + """ + Connect to the dynamic monitor socket, perform the QMP + greeting and capability negotiation, send a command, then + disconnect. + """ + qmp = QEMUMonitorProtocol(sock_path) + + # connect(negotiate=True) receives the greeting, validates it, + # and sends qmp_capabilities automatically. + greeting = qmp.connect(negotiate=True) + self.assertIn('QMP', greeting) + self.assertIn('version', greeting['QMP']) + self.assertIn('capabilities', greeting['QMP']) + + # Send a real command to prove the session is fully functional + resp = qmp.cmd_obj({'execute': 'query-version'}) + self.assertIn('return', resp) + self.assertIn('qemu', resp['return']) + + qmp.close() + + def test_hotplug_cycle(self): + """ + Hotplug a monitor, do the full QMP handshake, unplug it, + then repeat the whole cycle a second time. + """ + self.set_machine('none') + self.vm.add_args('-nodefaults') + self.vm.launch() + + # First cycle + sock = self._add_monitor() + self._connect_and_handshake(sock) + self._remove_monitor() + + # Second cycle -- same ids, same path, must work + sock = self._add_monitor() + self._connect_and_handshake(sock) + self._remove_monitor() + + def test_self_removal(self): + """ + A dynamically-added monitor sends object-del targeting + itself. Verify the request is rejected, but the monitor + can still be deleted from outside its own context. + """ + self.set_machine('none') + self.vm.add_args('-nodefaults') + self.vm.launch() + + sock = self._add_monitor() + + qmp = QEMUMonitorProtocol(sock) + greeting = qmp.connect(negotiate=True) + self.assertIn('QMP', greeting) + + # Self-removal: the dynamic monitor raises error + resp = qmp.cmd_obj({'execute': 'object-del', + 'arguments': {'id': 'hotplug-mon'}}) + self.assertIn('error', resp) + + qmp.close() + + resp = self.vm.cmd('object-del', id='hotplug-mon') + + # Clean up the chardev + self.vm.cmd('chardev-remove', id='hotplug-chr') + + def test_large_response(self): + """ + Send a command with a large response (query-qmp-schema) on a + dynamically-added monitor to exercise the output buffer flush + path. + """ + self.set_machine('none') + self.vm.add_args('-nodefaults') + self.vm.launch() + + sock = self._add_monitor() + + qmp = QEMUMonitorProtocol(sock) + qmp.connect(negotiate=True) + + resp = qmp.cmd_obj({'execute': 'query-qmp-schema'}) + self.assertIn('return', resp) + self.assertIsInstance(resp['return'], list) + self.assertGreater(len(resp['return']), 0) + + qmp.close() + self._remove_monitor() + + def test_events_after_negotiation(self): + """ + Verify that QMP events are delivered on a dynamically-added + monitor after capability negotiation completes. + """ + self.set_machine('none') + self.vm.add_args('-nodefaults') + self.vm.launch() + + sock = self._add_monitor() + + qmp = QEMUMonitorProtocol(sock) + qmp.connect(negotiate=True) + + # Trigger a STOP event via the main monitor, then read it + # from the dynamic monitor. + self.vm.cmd('stop') + resp = qmp.pull_event(wait=True) + self.assertEqual(resp['event'], 'STOP') + + self.vm.cmd('cont') + resp = qmp.pull_event(wait=True) + self.assertEqual(resp['event'], 'RESUME') + + qmp.close() + self._remove_monitor() + + +if __name__ == '__main__': + QemuSystemTest.main() -- 2.54.0

When unplugging a monitor there is a careful synchronization dance between the monitor handling the "object-del" command and the command processing for the monitor being deleted. The stress test runs a busy loop of 'query-qmp-schema' on a second monitor, while the primary monitor requests its deletion. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- .../generic/test_monitor_hotplug.py | 62 +++++++++++++++++++ 1 file changed, 62 insertions(+) diff --git a/tests/functional/generic/test_monitor_hotplug.py b/tests/functional/generic/test_monitor_hotplug.py index 5d8a159eb0..03087faafc 100755 --- a/tests/functional/generic/test_monitor_hotplug.py +++ b/tests/functional/generic/test_monitor_hotplug.py @@ -6,11 +6,16 @@ # # Copyright (c) 2026 Christian Brauner +import asyncio import os +import random +import threading +import time from qemu_test import QemuSystemTest from qemu.qmp.legacy import QEMUMonitorProtocol +from qemu.qmp import QMPClient class MonitorHotplug(QemuSystemTest): @@ -163,6 +168,63 @@ def test_events_after_negotiation(self): qmp.close() self._remove_monitor() + def stress_mon(self, sock): + async def main(): + qmp = QMPClient('testvm') + await qmp.connect(sock) + # Run query-version in a tight loop so that the + # monitor thread/dispatcher is very busy at the + # time we try to delete the monitor + while True: + try: + # A command which returns alot of data to make + # it more likely we're in the I/O reply path + # when deleting the monitor + res = await qmp.execute('query-qmp-schema') + # Some commands which generate async events + # as those can trigger different code paths + res = await qmp.execute('stop') + res = await qmp.execute('cont') + except: + # we'll get here if the monitor is terminated + # by QEMU in which case we must disconnect + # out side, but.... + try: + await qmp.disconnect() + except (ConnectionResetError, EOFError, BrokenPipeError): + # ... disconnect() will probably see + # errors too, but we must try to call it + # regardless to cleanup asyncio state + # and prevent python warnings at GC time + pass + return + asyncio.run(main()) + + def test_hotplug_stress(self): + """ + Repeatedly hotplug and unplug a monitor, while another thread + concurrently issues commands on that monitor. This stresses + the synchronization with the monitor thread during cleanup + """ + self.set_machine('none') + self.vm.add_args('-nodefaults') + self.vm.launch() + + # Each loop sleeps at most 0.5 seconds, so this should + # give an upper bound of approx 5 seconds execution + # time which is reasonable to run by default + repeat = 10 + for i in range(repeat): + # First cycle + sock = self._add_monitor() + print ("# stress cycle %02d/%02d" % (i, repeat)) + stress = threading.Thread(target=self.stress_mon, args=[sock]) + stress.start() + # Sleep upto 1/2 second to vary the races + time.sleep(random.random() / 0.5) + self._remove_monitor() + stress.join() + if __name__ == '__main__': QemuSystemTest.main() -- 2.54.0

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- qom/object_interfaces.c | 6 ++++++ qom/trace-events | 5 +++++ 2 files changed, 11 insertions(+) diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c index 6faa0b2fd9..2e618a7623 100644 --- a/qom/object_interfaces.c +++ b/qom/object_interfaces.c @@ -20,12 +20,14 @@ #include "qapi/opts-visitor.h" #include "qemu/config-file.h" #include "qemu/keyval.h" +#include "trace.h" bool user_creatable_complete(UserCreatable *uc, Error **errp) { UserCreatableClass *ucc = USER_CREATABLE_GET_CLASS(uc); ERRP_GUARD(); + trace_user_creatable_complete(uc, object_get_typename(OBJECT(uc))); if (ucc->complete) { ucc->complete(uc, errp); } @@ -37,9 +39,13 @@ bool user_creatable_prepare_delete(UserCreatable *uc, Error **errp) UserCreatableClass *ucc = USER_CREATABLE_GET_CLASS(uc); ERRP_GUARD(); + trace_user_creatable_prepare_delete(uc, object_get_typename(OBJECT(uc))); if (ucc->prepare_delete) { ucc->prepare_delete(uc, errp); } + trace_user_creatable_prepare_delete_result( + uc, object_get_typename(OBJECT(uc)), + *errp ? error_get_pretty(*errp) : NULL); return !*errp; } diff --git a/qom/trace-events b/qom/trace-events index 44c63e72af..bac8472618 100644 --- a/qom/trace-events +++ b/qom/trace-events @@ -11,3 +11,8 @@ object_property_del_child(void *obj, const char *type, void *child, const char * object_property_parse(void *obj, const char *type, const char *name, const char *value) "obj=%p type=%s prop=%s value=%s" object_class_dynamic_cast_assert(const char *type, const char *target, const char *file, int line, const char *func) "type=%s->%s (%s:%d:%s)" object_class_property_add(const char *type, const char *name, void *value) "type=%s name=%s value=%p" + +# object_interfaces.c +user_creatable_complete(void *obj, const char *type) "obj=%p type=%s" +user_creatable_prepare_delete(void *obj, const char *type) "obj=%p type=%s" +user_creatable_prepare_delete_result(void *obj, const char *type, const char *msg) "obj=%p type=%s msg=%s" -- 2.54.0

The default monitor is usually a long lived object that will exist for the entire lifetime of the VM. A monitor can only service a single client at a time though, and so it might be desirable to hotplug additional monitors at runtime for specific tasks. If doing that, however, there is a need to remove the monitor when it is no longer needed. Allowing a client to run "object-del" against its own monitor adds complex edge cases, as it would be desirable to send the QMP response despite the monitor sending it being deleted. Doing "object-del" alone will also result in orphaning a character device backend instance, as there is no opportunity to run the companion "chardev-del" command. A simpler way to ensure cleanup is to add the concept of auto-deleting monitor objects. Specifically when the "CHR_EVENT_CLOSED" event is emitted, the equivalent of "object-del" + "chardev-del" can be run internally. Since the transient client has already droppped its monitor connection, there is no synchronization to be concerned about. This is implemented via a new "close-action=none|delete" property on the 'monitor-qmp' object. This concept could be extended with further actions in future, for example: * close-action=shutdown - graceful guest shutdown * close-action=terminate - immediate guest poweroff * close-action=stop - pause guest CPUs while the monitor is not connected to any client This is left as an exercise for future interested contributors. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor-internal.h | 3 + monitor/qmp.c | 59 +++++++++++++++++++ qapi/qom.json | 21 ++++++- qemu-options.hx | 10 +++- .../generic/test_monitor_hotplug.py | 53 +++++++++++++++-- 5 files changed, 140 insertions(+), 6 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 2e8e5ec721..165002f535 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -28,6 +28,7 @@ #include "chardev/char-fe.h" #include "monitor/monitor.h" #include "qapi/qapi-types-control.h" +#include "qapi/qapi-types-qom.h" #include "qapi/qmp-registry.h" #include "qobject/json-parser.h" #include "qemu/readline.h" @@ -179,7 +180,9 @@ struct MonitorQMP { Monitor parent_obj; JSONMessageParser parser; bool pretty; + MonitorQMPCloseAction close_action; bool setup_pending; /* iothread BH has not yet set up chardev handlers */ + bool delete_pending; /* close_action has started 'delete' process */ /* * When a client connects, we're in capabilities negotiation mode. * @commands is &qmp_cap_negotiation_commands then. When command diff --git a/monitor/qmp.c b/monitor/qmp.c index d471428488..905f924ea6 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -28,6 +28,7 @@ #include "monitor-internal.h" #include "qapi/error.h" #include "qapi/qapi-commands-control.h" +#include "qapi/qapi-commands-char.h" #include "qobject/qdict.h" #include "qobject/qjson.h" #include "qobject/qlist.h" @@ -103,6 +104,20 @@ static void monitor_qmp_set_pretty(Object *obj, bool val, Error **errp) mon->pretty = val; } +static int monitor_qmp_get_close_action(Object *obj, Error **errp) +{ + MonitorQMP *mon = MONITOR_QMP(obj); + + return mon->close_action; +} + +static void monitor_qmp_set_close_action(Object *obj, int val, Error **errp) +{ + MonitorQMP *mon = MONITOR_QMP(obj); + + mon->close_action = val; +} + static void monitor_qmp_emit_event(Monitor *mon, QAPIEvent event, QDict *qdict); static bool monitor_qmp_requires_iothread(const Monitor *mon); static void monitor_qmp_complete(UserCreatable *uc, Error **errp); @@ -117,6 +132,11 @@ static void monitor_qmp_class_init(ObjectClass *cls, const void *data) object_class_property_add_bool(cls, "pretty", monitor_qmp_get_pretty, monitor_qmp_set_pretty); + object_class_property_add_enum(cls, "close-action", + "MonitorQMPCloseAction", + &MonitorQMPCloseAction_lookup, + monitor_qmp_get_close_action, + monitor_qmp_set_close_action); moncls->emit_event = monitor_qmp_emit_event; moncls->requires_iothread = monitor_qmp_requires_iothread; @@ -550,11 +570,33 @@ static QDict *qmp_greeting(MonitorQMP *mon) ver, cap_list); } +static void monitor_qmp_self_delete_bh(void *opaque) +{ + MonitorQMP *mon = opaque; + g_autofree char *mon_id = object_property_get_child_name( + object_get_objects_root(), OBJECT(mon)); + g_autofree char *chardev_id = g_strdup(mon->parent_obj.chardev_id); + Error *local_error = NULL; + + g_assert(mon_id); + + user_creatable_del(mon_id, &local_error); + if (local_error != NULL) { + error_report_err(local_error); + } else { + qmp_chardev_remove(chardev_id, NULL); + } +} + static void monitor_qmp_event(void *opaque, QEMUChrEvent event) { QDict *data; MonitorQMP *mon = opaque; + if (mon->delete_pending) { + return; + } + switch (event) { case CHR_EVENT_OPENED: WITH_QEMU_LOCK_GUARD(&mon->parent_obj.mon_lock) { @@ -577,6 +619,23 @@ static void monitor_qmp_event(void *opaque, QEMUChrEvent event) json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL); monitor_fdsets_cleanup(); + switch (mon->close_action) { + case MONITOR_QMP_CLOSE_ACTION_NONE: + break; /* nada */ + case MONITOR_QMP_CLOSE_ACTION_DELETE: + mon->delete_pending = true; + /* + * Do NOT run in the AIO context associated with the + * monitor. We need to run in the default AIO context + * which is the same context in which 'qmp_object_del' + * will execute + */ + aio_bh_schedule_oneshot(qemu_get_aio_context(), + monitor_qmp_self_delete_bh, mon); + break; + default: + g_assert_not_reached(); + } break; case CHR_EVENT_BREAK: case CHR_EVENT_MUX_IN: diff --git a/qapi/qom.json b/qapi/qom.json index 6ed510858e..63335b8fd0 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -1213,18 +1213,37 @@ 'base': 'MonitorProperties', 'data': { '*readline': 'bool' } } + +## +# @MonitorQMPCloseAction: +# +# Action to take when the character device backend is +# closed. +# +# @none: take no action (the default) +# @delete: delete both the 'monitor-qmp' object and its associated +# character device backend object +# +# Since 11.1 +## +{ 'enum' : 'MonitorQMPCloseAction', + 'data': ['none', 'delete'] } + ## # @MonitorQMPProperties: # # Properties for the QMP monitor # # @pretty: whether to pretty print JSON responses (default: disabled) +# @close-action: action to take when the character device backend +# is closed (default: none) # # Since: 11.1 ## { 'struct': 'MonitorQMPProperties', 'base': 'MonitorProperties', - 'data': { '*pretty': 'bool' } } + 'data': { '*pretty': 'bool', + '*close-action': 'MonitorQMPCloseAction' } } ## # @ObjectType: diff --git a/qemu-options.hx b/qemu-options.hx index 031417b79d..848a53ea34 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -5730,7 +5730,7 @@ SRST controls whether the monitor provides interactive prompts - ``-object monitor-qmp,id=id,chardev=chardev_id,pretty=on|off`` + ``-object monitor-qmp,id=id,chardev=chardev_id,pretty=on|off,close-action=none|delete`` Set up a monitor running the QEMU Monitor Protocol, connected to the chardev ``chrid``. @@ -5747,6 +5747,14 @@ SRST constrained to a single line without extraneous whitespace. + The ``close-action`` parameter, which defaults to ``none``, + controls what happens when the connection to the monitor + is terminated by the user. If set to ``delete``, then the + ``monitor-qmp`` object and its associated character + device are both immediately deleted. This can be useful + if an extra monitor was hotplugged for a specific task + and should be unplugged when completed. + ``-object memory-backend-file,id=id,size=size,mem-path=dir,share=on|off,discard-data=on|off,merge=on|off,dump=on|off,prealloc=on|off,host-nodes=host-nodes,policy=default|preferred|bind|interleave,align=align,offset=offset,readonly=on|off,rom=on|off|auto`` Creates a memory file backend object, which can be used to back the guest RAM with huge pages. diff --git a/tests/functional/generic/test_monitor_hotplug.py b/tests/functional/generic/test_monitor_hotplug.py index 03087faafc..f7d72a77c2 100755 --- a/tests/functional/generic/test_monitor_hotplug.py +++ b/tests/functional/generic/test_monitor_hotplug.py @@ -25,7 +25,7 @@ def setUp(self): sock_dir = self.socket_dir() self._sock_path = os.path.join(sock_dir.name, 'hotplug.sock') - def _add_monitor(self): + def _add_monitor(self, autodelete=False): """Create a chardev + monitor and return the socket path.""" sock = self._sock_path self.vm.cmd('chardev-add', id='hotplug-chr', backend={ @@ -39,9 +39,15 @@ def _add_monitor(self): 'wait': False, } }) - self.vm.cmd('object-add', id='hotplug-mon', - qom_type='monitor-qmp', - chardev='hotplug-chr') + if autodelete: + self.vm.cmd('object-add', id='hotplug-mon', + qom_type='monitor-qmp', + chardev='hotplug-chr', + close_action='delete') + else: + self.vm.cmd('object-add', id='hotplug-mon', + qom_type='monitor-qmp', + chardev='hotplug-chr') return sock def _remove_monitor(self): @@ -118,6 +124,45 @@ def test_self_removal(self): # Clean up the chardev self.vm.cmd('chardev-remove', id='hotplug-chr') + def test_auto_delete(self): + """ + A dynamically-added monitor is configured with 'close-action=delete' + should see itself deleted when the client is closed. + """ + self.set_machine('none') + self.vm.add_args('-nodefaults') + self.vm.launch() + + sock = self._add_monitor(autodelete=True) + + cdevs = [c["label"] for c in self.vm.cmd('query-chardev')] + objs = [o["name"] for o in self.vm.cmd('qom-list', path='/objects')] + assert ('hotplug-chr' in cdevs) + assert ('hotplug-mon' in objs) + + qmp = QEMUMonitorProtocol(sock) + greeting = qmp.connect(negotiate=True) + self.assertIn('QMP', greeting) + + cdevs = [c["label"] for c in self.vm.cmd('query-chardev')] + objs = [o["name"] for o in self.vm.cmd('qom-list', path='/objects')] + assert ('hotplug-chr' in cdevs) + assert ('hotplug-mon' in objs) + + qmp.close() + + for i in range(10): + cdevs = [c["label"] for c in self.vm.cmd('query-chardev')] + if 'hotplug-chr' not in cdevs: + break + # Sleep upto 1/2 second to vary the races + time.sleep(random.random() / 0.5) + + cdevs = [c["label"] for c in self.vm.cmd('query-chardev')] + objs = [o["name"] for o in self.vm.cmd('qom-list', path='/objects')] + assert ('hotplug-chr' not in cdevs) + assert ('hotplug-mon' not in objs) + def test_large_response(self): """ Send a command with a large response (query-qmp-schema) on a -- 2.54.0