While most objects can perform all their cleanup in the finalizer method, there can be interactions with other resources / subsystems / threads which require that some cleanup be performed on an user creatable object before unparenting it and entering finalization. The current 'can_be_deleted' method runs in the deletion path and is intended to be used to block deletion. While it could be used to perform cleanup tasks, its name suggests it should be free of side-effects. Generalize this by renaming it to 'prepare_delete', explicitly allowing for cleanup to be provided. Existing users of 'can_be_deleted' are re-written, which provides them with more detailed/tailored error messages. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- backends/cryptodev.c | 10 +++++++--- backends/hostmem.c | 5 +++-- backends/iommufd.c | 10 +++++++--- block/throttle-groups.c | 10 +++++++--- event-loop-base.c | 8 ++++---- include/qom/object_interfaces.h | 26 +++++++++++++++++--------- include/system/event-loop-base.h | 2 +- net/can/can_core.c | 5 +++-- qom/object_interfaces.c | 14 ++++++-------- tests/qemu-iotests/245 | 4 ++-- util/main-loop.c | 5 +++-- 11 files changed, 60 insertions(+), 39 deletions(-) diff --git a/backends/cryptodev.c b/backends/cryptodev.c index 79f8882d3b..90110dc633 100644 --- a/backends/cryptodev.c +++ b/backends/cryptodev.c @@ -454,9 +454,13 @@ bool cryptodev_backend_is_ready(CryptoDevBackend *backend) } static bool -cryptodev_backend_can_be_deleted(UserCreatable *uc) +cryptodev_backend_prepare_delete(UserCreatable *uc, Error **errp) { - return !cryptodev_backend_is_used(CRYPTODEV_BACKEND(uc)); + if (cryptodev_backend_is_used(CRYPTODEV_BACKEND(uc))) { + error_setg(errp, "Cryptodev backend is still in use"); + return false; + } + return true; } static void cryptodev_backend_instance_init(Object *obj) @@ -613,7 +617,7 @@ cryptodev_backend_class_init(ObjectClass *oc, const void *data) UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); ucc->complete = cryptodev_backend_complete; - ucc->can_be_deleted = cryptodev_backend_can_be_deleted; + ucc->prepare_delete = cryptodev_backend_prepare_delete; QTAILQ_INIT(&crypto_clients); object_class_property_add(oc, "queues", "uint32", diff --git a/backends/hostmem.c b/backends/hostmem.c index cd2085fb3c..eb915c64bc 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -434,9 +434,10 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp) } static bool -host_memory_backend_can_be_deleted(UserCreatable *uc) +host_memory_backend_prepare_delete(UserCreatable *uc, Error **errp) { if (host_memory_backend_is_mapped(MEMORY_BACKEND(uc))) { + error_setg(errp, "Host memory backend is still mapped"); return false; } else { return true; @@ -508,7 +509,7 @@ host_memory_backend_class_init(ObjectClass *oc, const void *data) UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); ucc->complete = host_memory_backend_memory_complete; - ucc->can_be_deleted = host_memory_backend_can_be_deleted; + ucc->prepare_delete = host_memory_backend_prepare_delete; object_class_property_add_bool(oc, "merge", host_memory_backend_get_merge, diff --git a/backends/iommufd.c b/backends/iommufd.c index 09624cd652..7af49f6de3 100644 --- a/backends/iommufd.c +++ b/backends/iommufd.c @@ -63,11 +63,15 @@ static void iommufd_backend_set_fd(Object *obj, const char *str, Error **errp) trace_iommu_backend_set_fd(be->fd); } -static bool iommufd_backend_can_be_deleted(UserCreatable *uc) +static bool iommufd_backend_prepare_delete(UserCreatable *uc, Error **errp) { IOMMUFDBackend *be = IOMMUFD_BACKEND(uc); - return !be->users; + if (be->users) { + error_setg(errp, "IOMMUFD backend still has %d users", be->users); + return false; + } + return true; } static void iommufd_backend_complete(UserCreatable *uc, Error **errp) @@ -92,7 +96,7 @@ static void iommufd_backend_class_init(ObjectClass *oc, const void *data) { UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); - ucc->can_be_deleted = iommufd_backend_can_be_deleted; + ucc->prepare_delete = iommufd_backend_prepare_delete; ucc->complete = iommufd_backend_complete; object_class_property_add_str(oc, "fd", NULL, iommufd_backend_set_fd); diff --git a/block/throttle-groups.c b/block/throttle-groups.c index 4b1b1944c2..7836fc4c76 100644 --- a/block/throttle-groups.c +++ b/block/throttle-groups.c @@ -960,9 +960,13 @@ static void throttle_group_get_limits(Object *obj, Visitor *v, visit_type_ThrottleLimits(v, name, &argp, errp); } -static bool throttle_group_can_be_deleted(UserCreatable *uc) +static bool throttle_group_prepare_delete(UserCreatable *uc, Error **errp) { - return OBJECT(uc)->ref == 1; + if (OBJECT(uc)->ref > 1) { + error_setg(errp, "Throttle group still has multiple references"); + return false; + } + return true; } static void throttle_group_obj_class_init(ObjectClass *klass, @@ -972,7 +976,7 @@ static void throttle_group_obj_class_init(ObjectClass *klass, UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass); ucc->complete = throttle_group_obj_complete; - ucc->can_be_deleted = throttle_group_can_be_deleted; + ucc->prepare_delete = throttle_group_prepare_delete; /* individual properties */ for (i = 0; i < sizeof(properties) / sizeof(ThrottleParamInfo); i++) { diff --git a/event-loop-base.c b/event-loop-base.c index 8ca143bea4..ee5987ddbf 100644 --- a/event-loop-base.c +++ b/event-loop-base.c @@ -85,13 +85,13 @@ static void event_loop_base_complete(UserCreatable *uc, Error **errp) } } -static bool event_loop_base_can_be_deleted(UserCreatable *uc) +static bool event_loop_base_prepare_delete(UserCreatable *uc, Error **errp) { EventLoopBaseClass *bc = EVENT_LOOP_BASE_GET_CLASS(uc); EventLoopBase *backend = EVENT_LOOP_BASE(uc); - if (bc->can_be_deleted) { - return bc->can_be_deleted(backend); + if (bc->prepare_delete) { + return bc->prepare_delete(backend, errp); } return true; @@ -102,7 +102,7 @@ static void event_loop_base_class_init(ObjectClass *klass, { UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass); ucc->complete = event_loop_base_complete; - ucc->can_be_deleted = event_loop_base_can_be_deleted; + ucc->prepare_delete = event_loop_base_prepare_delete; object_class_property_add(klass, "aio-max-batch", "int", event_loop_base_get_param, diff --git a/include/qom/object_interfaces.h b/include/qom/object_interfaces.h index e2b8615617..afd0fb93b2 100644 --- a/include/qom/object_interfaces.h +++ b/include/qom/object_interfaces.h @@ -20,8 +20,10 @@ typedef struct UserCreatable UserCreatable; * UserCreatableClass: * @parent_class: the base class * @complete: callback to be called after @obj's properties are set. - * @can_be_deleted: callback to be called before an object is removed - * to check if @obj can be removed safely. + * @prepare_delete: to be called before an attempt to delete @obj + * to validate whether the object can be deleted and trigger any + * cleanup of any resources which have to be dealt with before the + * object is unparented and enters finalization. * * Interface is designed to work with -object/object-add/object_add * commands. @@ -36,7 +38,9 @@ typedef struct UserCreatable UserCreatable; * For objects created without using -object/object-add/object_add, * @user_creatable_complete() wrapper should be called manually if * object's type implements USER_CREATABLE interface and needs - * complete() callback to be called. + * complete() callback to be called. Similarly @user_creatable_prepare_delete() + * should be called manually prior to an attempt to the delete the + * object. */ struct UserCreatableClass { /* <private> */ @@ -44,7 +48,7 @@ struct UserCreatableClass { /* <public> */ void (*complete)(UserCreatable *uc, Error **errp); - bool (*can_be_deleted)(UserCreatable *uc); + bool (*prepare_delete)(UserCreatable *uc, Error **errp); }; /** @@ -61,13 +65,17 @@ struct UserCreatableClass { bool user_creatable_complete(UserCreatable *uc, Error **errp); /** - * user_creatable_can_be_deleted: - * @uc: the object whose can_be_deleted() method is called if implemented + * user_creatable_prepare_delete: + * @uc: the user-creatable object whose prepare_delete() method is called + * @errp: if an error occurs, a pointer to an area to store the error + * + * Wrapper to call prepare_delete() class method if defined, otherwise + * does nothing. * - * Wrapper to call can_be_deleted() method if one of types it's inherited - * from implements USER_CREATABLE interface. + * Returns: %true on success or if prepare_delete() is not defined, + * %false on failure. */ -bool user_creatable_can_be_deleted(UserCreatable *uc); +bool user_creatable_prepare_delete(UserCreatable *uc, Error **errp); /** * user_creatable_add_qapi: diff --git a/include/system/event-loop-base.h b/include/system/event-loop-base.h index 130629e7f3..1e1e427ac7 100644 --- a/include/system/event-loop-base.h +++ b/include/system/event-loop-base.h @@ -24,7 +24,7 @@ struct EventLoopBaseClass { void (*init)(EventLoopBase *base, Error **errp); void (*update_params)(EventLoopBase *base, Error **errp); - bool (*can_be_deleted)(EventLoopBase *base); + bool (*prepare_delete)(EventLoopBase *base, Error **errp); }; struct EventLoopBase { diff --git a/net/can/can_core.c b/net/can/can_core.c index 77fe2b8ba4..8df9375167 100644 --- a/net/can/can_core.c +++ b/net/can/can_core.c @@ -143,8 +143,9 @@ int can_bus_client_set_filters(CanBusClientState *client, } -static bool can_bus_can_be_deleted(UserCreatable *uc) +static bool can_bus_prepare_delete(UserCreatable *uc, Error **errp) { + error_setg(errp, "Deleting can bus devices is not supported"); return false; } @@ -153,7 +154,7 @@ static void can_bus_class_init(ObjectClass *klass, { UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass); - uc_klass->can_be_deleted = can_bus_can_be_deleted; + uc_klass->prepare_delete = can_bus_prepare_delete; } static const TypeInfo can_bus_info = { diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c index 7080f85f95..6faa0b2fd9 100644 --- a/qom/object_interfaces.c +++ b/qom/object_interfaces.c @@ -32,16 +32,15 @@ bool user_creatable_complete(UserCreatable *uc, Error **errp) return !*errp; } -bool user_creatable_can_be_deleted(UserCreatable *uc) +bool user_creatable_prepare_delete(UserCreatable *uc, Error **errp) { - UserCreatableClass *ucc = USER_CREATABLE_GET_CLASS(uc); + ERRP_GUARD(); - if (ucc->can_be_deleted) { - return ucc->can_be_deleted(uc); - } else { - return true; + if (ucc->prepare_delete) { + ucc->prepare_delete(uc, errp); } + return !*errp; } void user_creatable_add_qapi(ObjectOptions *options, Error **errp) @@ -253,8 +252,7 @@ bool user_creatable_del(const char *id, Error **errp) return false; } - if (!user_creatable_can_be_deleted(USER_CREATABLE(obj))) { - error_setg(errp, "object '%s' is in use, can not be deleted", id); + if (!user_creatable_prepare_delete(USER_CREATABLE(obj), errp)) { return false; } diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245 index f96610f510..e161bcfda9 100755 --- a/tests/qemu-iotests/245 +++ b/tests/qemu-iotests/245 @@ -801,7 +801,7 @@ class TestBlockdevReopen(iotests.QMPTestCase): # Now group1 is in use, it cannot be deleted result = self.vm.qmp('object-del', id = 'group1') self.assert_qmp(result, 'error/class', 'GenericError') - self.assert_qmp(result, 'error/desc', "object 'group1' is in use, can not be deleted") + self.assert_qmp(result, 'error/desc', "Throttle group still has multiple references") # Default options, this switches the group back to group0 self.reopen(opts) @@ -809,7 +809,7 @@ class TestBlockdevReopen(iotests.QMPTestCase): # So now we cannot delete group0 result = self.vm.qmp('object-del', id = 'group0') self.assert_qmp(result, 'error/class', 'GenericError') - self.assert_qmp(result, 'error/desc', "object 'group0' is in use, can not be deleted") + self.assert_qmp(result, 'error/desc', "Throttle group still has multiple references") # But group1 is free this time, and it can be deleted self.vm.cmd('object-del', id = 'group1') diff --git a/util/main-loop.c b/util/main-loop.c index ad8645c30a..67ee06c311 100644 --- a/util/main-loop.c +++ b/util/main-loop.c @@ -218,8 +218,9 @@ static void main_loop_init(EventLoopBase *base, Error **errp) mloop = m; } -static bool main_loop_can_be_deleted(EventLoopBase *base) +static bool main_loop_prepare_delete(EventLoopBase *base, Error **errp) { + error_setg(errp, "Deleting main loop is not supported"); return false; } @@ -229,7 +230,7 @@ static void main_loop_class_init(ObjectClass *oc, const void *class_data) bc->init = main_loop_init; bc->update_params = main_loop_update_params; - bc->can_be_deleted = main_loop_can_be_deleted; + bc->prepare_delete = main_loop_prepare_delete; } static const TypeInfo main_loop_info = { -- 2.54.0

The field name 'parent_obj' is standard practice for QOM structs so align the QMP monitor. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor-internal.h | 2 +- monitor/monitor.c | 4 ++-- monitor/qmp-cmds-control.c | 4 ++-- monitor/qmp.c | 40 +++++++++++++++++++------------------- 4 files changed, 25 insertions(+), 25 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index eb301ea796..4da2b2a677 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -141,7 +141,7 @@ struct MonitorHMP { }; typedef struct { - Monitor common; + Monitor parent_obj; JSONMessageParser parser; bool pretty; /* diff --git a/monitor/monitor.c b/monitor/monitor.c index 2a1b511ff4..0b7b464ebe 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -308,7 +308,7 @@ static void monitor_qapi_event_emit(QAPIEvent event, QDict *qdict) continue; } - qmp_mon = container_of(mon, MonitorQMP, common); + qmp_mon = container_of(mon, MonitorQMP, parent_obj); { QEMU_LOCK_GUARD(&mon->mon_lock); if (qmp_mon->commands == &qmp_cap_negotiation_commands) { @@ -625,7 +625,7 @@ void monitor_data_destroy(Monitor *mon) g_free(mon->mon_cpu_path); qemu_chr_fe_deinit(&mon->chr, false); if (monitor_is_qmp(mon)) { - monitor_data_destroy_qmp(container_of(mon, MonitorQMP, common)); + monitor_data_destroy_qmp(container_of(mon, MonitorQMP, parent_obj)); } else { readline_free(container_of(mon, MonitorHMP, parent_obj)->rs); } diff --git a/monitor/qmp-cmds-control.c b/monitor/qmp-cmds-control.c index 150ca9f5cb..af6a2a118b 100644 --- a/monitor/qmp-cmds-control.c +++ b/monitor/qmp-cmds-control.c @@ -76,7 +76,7 @@ void qmp_qmp_capabilities(bool has_enable, QMPCapabilityList *enable, MonitorQMP *mon; assert(monitor_is_qmp(cur_mon)); - mon = container_of(cur_mon, MonitorQMP, common); + mon = container_of(cur_mon, MonitorQMP, parent_obj); if (mon->commands == &qmp_commands) { error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND, @@ -126,7 +126,7 @@ CommandInfoList *qmp_query_commands(Error **errp) MonitorQMP *mon; assert(monitor_is_qmp(cur_mon)); - mon = container_of(cur_mon, MonitorQMP, common); + mon = container_of(cur_mon, MonitorQMP, parent_obj); qmp_for_each_command(mon->commands, query_commands_cb, &list); diff --git a/monitor/qmp.c b/monitor/qmp.c index 687019811f..27934206db 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -80,7 +80,7 @@ static void monitor_qmp_caps_reset(MonitorQMP *mon) { memset(mon->capab_offered, 0, sizeof(mon->capab_offered)); memset(mon->capab, 0, sizeof(mon->capab)); - mon->capab_offered[QMP_CAPABILITY_OOB] = mon->common.use_io_thread; + mon->capab_offered[QMP_CAPABILITY_OOB] = mon->parent_obj.use_io_thread; } static void qmp_request_free(QMPRequest *req) @@ -124,7 +124,7 @@ static void monitor_qmp_cleanup_queue_and_resume(MonitorQMP *mon) * when we get here while the monitor is suspended. An * unfortunately timed CHR_EVENT_CLOSED can do the trick. */ - monitor_resume(&mon->common); + monitor_resume(&mon->parent_obj); } } @@ -139,7 +139,7 @@ void qmp_send_response(MonitorQMP *mon, const QDict *rsp) trace_monitor_qmp_respond(mon, json->str); g_string_append_c(json, '\n'); - monitor_puts(&mon->common, json->str); + monitor_puts(&mon->parent_obj, json->str); g_string_free(json, true); } @@ -166,7 +166,7 @@ static void monitor_qmp_dispatch(MonitorQMP *mon, QObject *req) QDict *error; rsp = qmp_dispatch(mon->commands, req, qmp_oob_enabled(mon), - &mon->common); + &mon->parent_obj); if (mon->commands == &qmp_cap_negotiation_commands) { error = qdict_get_qdict(rsp, "error"); @@ -207,7 +207,7 @@ static QMPRequest *monitor_qmp_requests_pop_any_with_lock(void) continue; } - qmp_mon = container_of(mon, MonitorQMP, common); + 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) { @@ -302,7 +302,7 @@ void coroutine_fn monitor_qmp_dispatcher_co(void *data) oob_enabled = qmp_oob_enabled(mon); if (oob_enabled && mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1) { - monitor_resume(&mon->common); + monitor_resume(&mon->parent_obj); } /* @@ -343,7 +343,7 @@ void coroutine_fn monitor_qmp_dispatcher_co(void *data) } if (!oob_enabled) { - monitor_resume(&mon->common); + monitor_resume(&mon->parent_obj); } qmp_request_free(req_obj); @@ -408,7 +408,7 @@ static void handle_qmp_command(void *opaque, QObject *req, Error *err) */ if (!qmp_oob_enabled(mon) || mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1) { - monitor_suspend(&mon->common); + monitor_suspend(&mon->parent_obj); } /* @@ -462,7 +462,7 @@ static void monitor_qmp_event(void *opaque, QEMUChrEvent event) switch (event) { case CHR_EVENT_OPENED: - WITH_QEMU_LOCK_GUARD(&mon->common.mon_lock) { + WITH_QEMU_LOCK_GUARD(&mon->parent_obj.mon_lock) { mon->commands = &qmp_cap_negotiation_commands; monitor_qmp_caps_reset(mon); } @@ -504,27 +504,27 @@ static void monitor_qmp_setup_handlers_bh(void *opaque) MonitorQMP *mon = opaque; GMainContext *context; - assert(mon->common.use_io_thread); + assert(mon->parent_obj.use_io_thread); context = iothread_get_g_main_context(mon_iothread); assert(context); - qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read, + qemu_chr_fe_set_handlers(&mon->parent_obj.chr, monitor_can_read, monitor_qmp_read, monitor_qmp_event, - NULL, &mon->common, context, true); - monitor_list_append(&mon->common); + NULL, &mon->parent_obj, context, true); + monitor_list_append(&mon->parent_obj); } void monitor_init_qmp(Chardev *chr, bool pretty, Error **errp) { MonitorQMP *mon = g_new0(MonitorQMP, 1); - if (!qemu_chr_fe_init(&mon->common.chr, chr, errp)) { + if (!qemu_chr_fe_init(&mon->parent_obj.chr, chr, errp)) { g_free(mon); return; } - qemu_chr_fe_set_echo(&mon->common.chr, true); + 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->common, true, false, + monitor_data_init(&mon->parent_obj, true, false, qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT)); mon->pretty = pretty; @@ -533,7 +533,7 @@ void monitor_init_qmp(Chardev *chr, bool pretty, Error **errp) mon->qmp_requests = g_queue_new(); json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL); - if (mon->common.use_io_thread) { + if (mon->parent_obj.use_io_thread) { /* * Make sure the old iowatch is gone. It's possible when * e.g. the chardev is in client mode, with wait=on. @@ -553,9 +553,9 @@ void monitor_init_qmp(Chardev *chr, bool pretty, Error **errp) monitor_qmp_setup_handlers_bh, mon); /* The bottom half will add @mon to @mon_list */ } else { - qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read, + qemu_chr_fe_set_handlers(&mon->parent_obj.chr, monitor_can_read, monitor_qmp_read, monitor_qmp_event, - NULL, &mon->common, NULL, true); - monitor_list_append(&mon->common); + NULL, &mon->parent_obj, NULL, true); + monitor_list_append(&mon->parent_obj); } } -- 2.54.0

This introduces a Monitor QOM object, with MonitorHMP and MonitorQMP subclasses. This is the bare minimum conversion of just the type declarations and replacing g_new/g_free with object_new/object_unref. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- include/monitor/monitor.h | 11 ++++++++++- monitor/hmp.c | 29 +++++++++++++++++++++++++++-- monitor/monitor-internal.h | 18 ++++++++++++++++-- monitor/monitor.c | 18 ++++++++++++++++-- monitor/qmp-cmds.c | 15 ++++++++------- monitor/qmp.c | 29 +++++++++++++++++++++++++++-- 6 files changed, 104 insertions(+), 16 deletions(-) diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h index b9642b58ba..2e9f9e12e9 100644 --- a/include/monitor/monitor.h +++ b/include/monitor/monitor.h @@ -5,8 +5,17 @@ #include "qapi/qapi-types-misc.h" #include "qemu/readline.h" #include "exec/hwaddr.h" +#include "qom/object.h" + +#define TYPE_MONITOR "monitor" +OBJECT_DECLARE_TYPE(Monitor, MonitorClass, MONITOR); + +#define TYPE_MONITOR_HMP "monitor-hmp" +OBJECT_DECLARE_TYPE(MonitorHMP, MonitorHMPClass, MONITOR_HMP); + +#define TYPE_MONITOR_QMP "monitor-qmp" +OBJECT_DECLARE_TYPE(MonitorQMP, MonitorQMPClass, MONITOR_QMP); -typedef struct MonitorHMP MonitorHMP; typedef struct MonitorOptions MonitorOptions; #define QMP_REQ_QUEUE_LEN_MAX 8 diff --git a/monitor/hmp.c b/monitor/hmp.c index 4e4468424a..81047d2513 100644 --- a/monitor/hmp.c +++ b/monitor/hmp.c @@ -43,6 +43,20 @@ #include "system/block-backend.h" #include "trace.h" +OBJECT_DEFINE_TYPE(MonitorHMP, monitor_hmp, MONITOR_HMP, MONITOR); + +static void monitor_hmp_finalize(Object *obj) +{ +} + +static void monitor_hmp_class_init(ObjectClass *cls, const void *data) +{ +} + +static void monitor_hmp_init(Object *obj) +{ +} + static void monitor_command_cb(void *opaque, const char *cmdline, void *readline_opaque) { @@ -1526,10 +1540,21 @@ static void monitor_readline_flush(void *opaque) void monitor_new_hmp(Chardev *chr, bool use_readline, Error **errp) { - MonitorHMP *mon = g_new0(MonitorHMP, 1); + 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, + NULL); + if (!obj) { + return; + } + mon = MONITOR_HMP(obj); if (!qemu_chr_fe_init(&mon->parent_obj.chr, chr, errp)) { - g_free(mon); + object_unparent(OBJECT(mon)); return; } diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 4da2b2a677..05c1f2f5e0 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -101,7 +101,13 @@ typedef struct HMPCommand { bool coroutine; } HMPCommand; + +struct MonitorClass { + ObjectClass parent_class; +}; + struct Monitor { + Object parent; CharFrontend chr; int suspend_cnt; /* Needs to be accessed atomically */ bool is_qmp; @@ -127,6 +133,10 @@ struct Monitor { int reset_seen; }; +struct MonitorHMPClass { + MonitorClass parent_class; +}; + struct MonitorHMP { Monitor parent_obj; bool use_readline; @@ -140,7 +150,11 @@ struct MonitorHMP { ReadLineState *rs; }; -typedef struct { +struct MonitorQMPClass { + MonitorClass parent_class; +}; + +struct MonitorQMP { Monitor parent_obj; JSONMessageParser parser; bool pretty; @@ -160,7 +174,7 @@ typedef struct { QemuMutex qmp_queue_lock; /* Input queue that holds all the parsed QMP requests */ GQueue *qmp_requests; -} MonitorQMP; +}; /** * Is @mon a QMP monitor? diff --git a/monitor/monitor.c b/monitor/monitor.c index a87597e606..a497c25c54 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -73,6 +73,20 @@ static GHashTable *coroutine_mon; /* Maps Coroutine* to Monitor* */ MonitorList mon_list; static bool monitor_destroyed; +OBJECT_DEFINE_TYPE(Monitor, monitor, MONITOR, OBJECT); + +static void monitor_finalize(Object *obj) +{ +} + +static void monitor_class_init(ObjectClass *cls, const void *data) +{ +} + +static void monitor_init(Object *obj) +{ +} + Monitor *monitor_cur(void) { Monitor *mon; @@ -598,7 +612,7 @@ void monitor_list_append(Monitor *mon) if (mon) { monitor_data_destroy(mon); - g_free(mon); + object_unparent(OBJECT(mon)); } } @@ -680,7 +694,7 @@ void monitor_cleanup(void) monitor_flush(mon); monitor_data_destroy(mon); qemu_mutex_lock(&monitor_lock); - g_free(mon); + object_unparent(OBJECT(mon)); } qemu_mutex_unlock(&monitor_lock); diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c index aa9ee8a391..bfde769ef0 100644 --- a/monitor/qmp-cmds.c +++ b/monitor/qmp-cmds.c @@ -166,12 +166,12 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index, int64_t cpu_index, Error **errp) { char *output = NULL; - MonitorHMP hmp = {}; + 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, true, false); if (has_cpu_index) { - int ret = monitor_set_cpu(&hmp.parent_obj, cpu_index); + int ret = monitor_set_cpu(&hmp->parent_obj, cpu_index); if (ret < 0) { error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cpu-index", "a CPU number"); @@ -179,14 +179,15 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index, } } - handle_hmp_command(&hmp, command_line); + handle_hmp_command(hmp, command_line); - WITH_QEMU_LOCK_GUARD(&hmp.parent_obj.mon_lock) { - output = g_strdup(hmp.parent_obj.outbuf->str); + WITH_QEMU_LOCK_GUARD(&hmp->parent_obj.mon_lock) { + output = g_strdup(hmp->parent_obj.outbuf->str); } out: - monitor_data_destroy(&hmp.parent_obj); + monitor_data_destroy(&hmp->parent_obj); + object_unref(hmp); return output; } diff --git a/monitor/qmp.c b/monitor/qmp.c index cb28a95efd..5231ed506a 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -71,6 +71,20 @@ typedef struct QMPRequest QMPRequest; QmpCommandList qmp_commands, qmp_cap_negotiation_commands; +OBJECT_DEFINE_TYPE(MonitorQMP, monitor_qmp, MONITOR_QMP, MONITOR); + +static void monitor_qmp_finalize(Object *obj) +{ +} + +static void monitor_qmp_class_init(ObjectClass *cls, const void *data) +{ +} + +static void monitor_qmp_init(Object *obj) +{ +} + static bool qmp_oob_enabled(MonitorQMP *mon) { return mon->capab[QMP_CAPABILITY_OOB]; @@ -515,10 +529,21 @@ static void monitor_qmp_setup_handlers_bh(void *opaque) void monitor_new_qmp(Chardev *chr, bool pretty, Error **errp) { - MonitorQMP *mon = g_new0(MonitorQMP, 1); + 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, + NULL); + if (!obj) { + return; + } + mon = MONITOR_QMP(obj); if (!qemu_chr_fe_init(&mon->parent_obj.chr, chr, errp)) { - g_free(mon); + object_unparent(OBJECT(mon)); return; } qemu_chr_fe_set_echo(&mon->parent_obj.chr, true); -- 2.54.0

This determines whether a human monitor runs with readline for interactive use, or without readline for non-interactive use by the GDB stub. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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

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. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 747ca27fd5..e3e5623a4b 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -188,7 +188,12 @@ 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; } @@ -642,8 +647,7 @@ 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(); @@ -651,7 +655,6 @@ 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 2a8532ef96..e3318b57db 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -572,7 +572,7 @@ 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

This removes the need for using monitor_is_qmp() to check the subclass type, which is an anti-pattern. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dave@treblig.org> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 76df379a2c..8b70380d64 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -262,21 +262,18 @@ 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. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 6f0353d9f1..2f16cd3053 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -576,16 +576,10 @@ 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

This eliminates a use of monitor_is_qmp() from the QMP coroutine dispatch path. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 93f576c19d..d2a03bb7e3 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

The previous patch dropped the only remaining use of monitor_cur_is_qmp. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 b788669f1f..0db7903795 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -150,16 +150,6 @@ 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 checking !monitor_is_qmp(), use a dynamic cast to check for HMP. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 0db7903795..15e49d78d7 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -168,7 +168,7 @@ 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 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. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 6ed586fc4f..f88364a574 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -155,25 +155,6 @@ 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) { @@ -548,12 +529,8 @@ 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)) { @@ -565,7 +542,6 @@ int monitor_suspend(Monitor *mon) } trace_monitor_suspend(mon, 1); - return 0; } static void monitor_accept_input(void *opaque) @@ -582,10 +558,6 @@ 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

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] Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 0e1c3eb52b..b0535dec68 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; @@ -646,6 +656,13 @@ 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 removal sequence is: 1. 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] Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor-internal.h | 2 ++ monitor/monitor.c | 22 ++++++++++++++++ monitor/qmp.c | 54 ++++++++++++++++++++++++++++++++++++-- 3 files changed, 76 insertions(+), 2 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index a82e1aacb6..5522e05464 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -178,6 +178,7 @@ 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 +207,7 @@ 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 0e1c623555..b155f58546 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -177,6 +177,28 @@ 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 2131be82c7..5301927f09 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); @@ -597,6 +603,7 @@ static void monitor_qmp_setup_handlers_bh(void *opaque) monitor_qmp_read, monitor_qmp_event, NULL, &mon->parent_obj, context, true); monitor_list_append(&mon->parent_obj); + qatomic_set(&mon->setup_pending, false); } void monitor_new_qmp(const char *chardev_id, bool pretty, Error **errp) @@ -645,6 +652,7 @@ static void monitor_qmp_complete(UserCreatable *uc, Error **errp) * since chardev might be running in the monitor I/O * thread. Schedule a bottom half. */ + mon->setup_pending = true; aio_bh_schedule_oneshot(iothread_get_aio_context(mon_iothread), monitor_qmp_setup_handlers_bh, mon); /* The bottom half will add @mon to @mon_list */ @@ -656,8 +664,14 @@ 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)) { @@ -665,8 +679,44 @@ 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) { + 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> 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] Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> 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 93df53d87f..c74ffe56ae 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3616,6 +3616,7 @@ 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

The 'user_creatable_del' method doesn't want the 'Object *', but instead the "id" of the object to be deleted. While most of its work could be done with the "Object *" alone, purging the QemuOpts values needs the "id". The "id" is not recorded against an Object though, it is indirectly stored as a property linking the parent and child objects together. Add an accessor that can fetch this property name. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- include/qom/object.h | 10 ++++++++++ qom/object.c | 17 +++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/include/qom/object.h b/include/qom/object.h index 11f55613fc..216d2a30f6 100644 --- a/include/qom/object.h +++ b/include/qom/object.h @@ -1759,6 +1759,16 @@ ObjectProperty *object_property_try_add_child(Object *obj, const char *name, ObjectProperty *object_property_add_child(Object *obj, const char *name, Object *child); +/** + * object_property_get_child_name: + * @obj: the object that owns the property + * @child: the object referenced by the child property + * + * Return the property name against which @child is registered + * with @obj, or NULL if @obj is not a parent of @child. + */ +char *object_property_get_child_name(Object *obj, Object *child); + typedef enum { /* Unref the link pointer when the property is deleted */ OBJ_PROP_LINK_STRONG = 0x1, diff --git a/qom/object.c b/qom/object.c index f79b2cf361..66bbd1488b 100644 --- a/qom/object.c +++ b/qom/object.c @@ -1952,6 +1952,23 @@ object_property_add_child(Object *obj, const char *name, return object_property_try_add_child(obj, name, child, &error_abort); } +char *object_property_get_child_name(Object *obj, Object *child) +{ + ObjectProperty *prop; + GHashTableIter iter; + gpointer key, value; + + g_hash_table_iter_init(&iter, obj->properties); + while (g_hash_table_iter_next(&iter, &key, &value)) { + prop = value; + if (object_property_is_child(prop) && prop->opaque == child) { + return g_strdup(prop->name); + } + } + return NULL; +} + + void object_property_allow_set_link(const Object *obj, const char *name, Object *val, Error **errp) { -- 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. Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- monitor/monitor-internal.h | 3 + monitor/qmp.c | 75 +++++++++++++++++ qapi/qom.json | 21 ++++- .../generic/test_monitor_hotplug.py | 83 ++++++++++++++++++- 4 files changed, 177 insertions(+), 5 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 5522e05464..23829f32f9 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" @@ -178,7 +179,9 @@ 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 5301927f09..1057b0d12b 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 +570,45 @@ 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; + + if (!mon_id) { + /* Another monitor raced & ran 'object-del' on 'mon' + * before this BH got scheduled, so we have a ref on + * mon but it is already unparented. + */ + object_unref(mon); + return; + } + + user_creatable_del(mon_id, &local_error); + object_unref(mon); + 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; + /* Protect against race if a client drops & quickly + * reconnects - we'll have the delete BH scheduled + * so must not honour a new open request + */ + if (mon->delete_pending) { + return; + } + switch (event) { case CHR_EVENT_OPENED: WITH_QEMU_LOCK_GUARD(&mon->parent_obj.mon_lock) { @@ -577,6 +631,27 @@ 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 + * + * Hold an extra ref in case a separate monitor races + * with the BH by processing an explicit 'object-del' + */ + object_ref(mon); + 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 6affb70a59..b4c49a2e8b 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/tests/functional/generic/test_monitor_hotplug.py b/tests/functional/generic/test_monitor_hotplug.py index 55af8a238f..86092e781c 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 +124,75 @@ 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 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() + + # Wait upto 10 seconds max for chardev to auto-delete, which + # is hopefully enough for reliability under high load + for i in range(int(10 / 0.2)): + cdevs = [c["label"] for c in self.vm.cmd('query-chardev')] + if 'hotplug-chr' not in cdevs: + break + # Wait a little more then try again + time.sleep(0.2) + + 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_reconnect(self): + """ + A dynamically-added monitor configured without 'close-action' + should allow reconnects after the client is closed. + """ + 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-chardev'}) + self.assertIn('return', resp) + + qmp.close() + + qmp = QEMUMonitorProtocol(sock) + qmp.connect(negotiate=True) + + resp = qmp.cmd_obj({'execute': 'query-chardev'}) + self.assertIn('return', resp) + + qmp.close() + self._remove_monitor() + def test_large_response(self): """ Send a command with a large response (query-qmp-schema) on a -- 2.54.0

Use the new preferred low level option for configuring the QMP service in libqtest and the python Machine class used by tests. This will avoid triggering deprecation warnings after the subsequent commit. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- python/qemu/machine/machine.py | 4 ++-- tests/qtest/libqtest.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py index ebb58d5b68..5f4845f5fb 100644 --- a/python/qemu/machine/machine.py +++ b/python/qemu/machine/machine.py @@ -304,8 +304,8 @@ def _base_args(self) -> List[str]: ) else: moncdev = f"socket,id=mon,path={self._monitor_address}" - args.extend(['-chardev', moncdev, '-mon', - 'chardev=mon,mode=control']) + args.extend(['-chardev', moncdev, '-object', + 'monitor-qmp,id=qmp,chardev=mon']) if self._machine is not None: args.extend(['-machine', self._machine]) diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c index 4e22c66b75..c33c799c92 100644 --- a/tests/qtest/libqtest.c +++ b/tests/qtest/libqtest.c @@ -460,7 +460,7 @@ gchar *qtest_qemu_args(const char *extra_args) "-qtest unix:%s " "-qtest-log %s " "-chardev socket,path=%s,id=char0 " - "-mon chardev=char0,mode=control " + "-object monitor-qmp,id=qmp0,chardev=char0 " "-display none " "-audio none " "%s " -- 2.54.0

The high level `-qmp` and `-monitor` options can remain as convenience wrappers, but the low level `-mon` is completed obsoleted by the new `-object` support with 'monitor-qmp' and 'monitor-hmp' types. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- docs/about/deprecated.rst | 10 ++++++++++ docs/devel/writing-monitor-commands.rst | 4 ++-- docs/system/arm/xenpvh.rst | 4 ++-- docs/system/i386/xen.rst | 3 ++- docs/system/i386/xenpvh.rst | 4 ++-- qemu-options.hx | 11 ++++++----- system/vl.c | 2 ++ 7 files changed, 26 insertions(+), 12 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 97750f5edc..8370fc5680 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -61,6 +61,16 @@ The ``debug-threads`` option of the ``-name`` argument is now ignored. Thread naming is unconditionally enabled for all platforms where it is supported. +``-mon`` option (since 11.1) +'''''''''''''''''''''''''''' + +The ``-mon`` option was the generic mechanism for creating monitor objects +if the convenience ``-qmp`` or ``-monitor`` options were not flexible +enough. The monitor objects have been converted to QOM, so ``-mon mode=readline`` +is replaced by ``-object monitor-hmp`` and ``-mon mode=control`` is replaced +by ``-object monitor-qmp``. The short convenience options are not deprecated, +only ``-mon``. + QEMU Machine Protocol (QMP) commands ------------------------------------ diff --git a/docs/devel/writing-monitor-commands.rst b/docs/devel/writing-monitor-commands.rst index 930da5cd06..7ae7efe327 100644 --- a/docs/devel/writing-monitor-commands.rst +++ b/docs/devel/writing-monitor-commands.rst @@ -52,8 +52,8 @@ shown here. First, QEMU should be started like this:: # qemu-system-TARGET [...] \ - -chardev socket,id=qmp,port=4444,host=localhost,server=on \ - -mon chardev=qmp,mode=control,pretty=on + -chardev socket,id=chrqmp0,port=4444,host=localhost,server=on \ + -object monitor-qmp,chardev=chrqmp0,pretty=on,id=qmp0 Then, in a different terminal:: diff --git a/docs/system/arm/xenpvh.rst b/docs/system/arm/xenpvh.rst index 430ac2c02e..511af63e3d 100644 --- a/docs/system/arm/xenpvh.rst +++ b/docs/system/arm/xenpvh.rst @@ -27,9 +27,9 @@ Sample QEMU xenpvh commands for running and connecting with Xen: qemu-system-aarch64 -xen-domid 1 \ -chardev socket,id=libxl-cmd,path=qmp-libxl-1,server=on,wait=off \ - -mon chardev=libxl-cmd,mode=control \ + -object monitor-qmp,id=qmp0,chardev=libxl-cmd \ -chardev socket,id=libxenstat-cmd,path=qmp-libxenstat-1,server=on,wait=off \ - -mon chardev=libxenstat-cmd,mode=control \ + -object monitor-qmp,id=qmp1,chardev=libxenstat-cmd \ -xen-attach -name guest0 -vnc none -display none -nographic \ -machine xenpvh -m 1301 \ -chardev socket,id=chrtpm,path=tmp/vtpm2/swtpm-sock \ diff --git a/docs/system/i386/xen.rst b/docs/system/i386/xen.rst index 46db5f34c1..6ff5cdb1e4 100644 --- a/docs/system/i386/xen.rst +++ b/docs/system/i386/xen.rst @@ -79,7 +79,8 @@ of type ``xen-console`` to connect to it. For the Xen console equivalent of the handy ``-serial mon:stdio`` option, for example: .. parsed-literal:: - -chardev stdio,mux=on,id=char0,signal=off -mon char0 \\ + -chardev stdio,mux=on,id=char0,signal=off \\ + -object monitor-hmp,chardev=char0,id=hmp0 \\ -device xen-console,chardev=char0 The Xen network device is ``xen-net-device``, which becomes the default NIC diff --git a/docs/system/i386/xenpvh.rst b/docs/system/i386/xenpvh.rst index 354250f073..904778e3f5 100644 --- a/docs/system/i386/xenpvh.rst +++ b/docs/system/i386/xenpvh.rst @@ -33,9 +33,9 @@ case you need to construct one manually: qemu-system-i386 -xen-domid 3 -no-shutdown \ -chardev socket,id=libxl-cmd,path=/var/run/xen/qmp-libxl-3,server=on,wait=off \ - -mon chardev=libxl-cmd,mode=control \ + -object monitor-qmp,id=qmp0,chardev=libxl-cmd \ -chardev socket,id=libxenstat-cmd,path=/var/run/xen/qmp-libxenstat-3,server=on,wait=off \ - -mon chardev=libxenstat-cmd,mode=control \ + -object monitor-qmp,id=qmp1,chardev=libxenstat-cmd \ -nodefaults \ -no-user-config \ -xen-attach -name g0 \ diff --git a/qemu-options.hx b/qemu-options.hx index a804d5b880..999dca7444 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4137,7 +4137,7 @@ The general form of a character device option is: :: -chardev stdio,mux=on,id=char0 \ - -mon chardev=char0,mode=readline \ + -object monitor-hmp,id=hmp0,chardev=char0 \ -serial chardev:char0 \ -serial chardev:char0 @@ -4149,7 +4149,7 @@ The general form of a character device option is: :: -chardev stdio,mux=on,id=char0 \ - -mon chardev=char0,mode=readline \ + -object monitor-hmp,id=hmp0,chardev=char0 \ -parallel chardev:char0 \ -chardev tcp,...,mux=on,id=char1 \ -serial chardev:char1 \ @@ -4950,7 +4950,8 @@ SRST -qmp tcp:localhost:4444,server=on,wait=off Not all options are configurable via this syntax; for maximum - flexibility use the ``-mon`` option and an accompanying ``-chardev``. + flexibility use ``-object monitor-qmp`` and an accompanying + ``-chardev``. ERST DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ @@ -4981,12 +4982,12 @@ SRST enables the QMP monitor on localhost port 4444 with pretty-printing. - The use of ``-mon mode=readline`` is historical syntax sugar + The use of ``-mon mode=readline`` is deprecated 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 + The use of ``-mon mode=control`` is deprecated 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. diff --git a/system/vl.c b/system/vl.c index 79ed2be449..a7b6d37452 100644 --- a/system/vl.c +++ b/system/vl.c @@ -3240,6 +3240,8 @@ void qemu_init(int argc, char **argv) default_monitor = 0; break; case QEMU_OPTION_mon: + warn_report_once("'-mon' is deprecated, use '-object' with " + "'monitor-hmp' or 'monitor-qmp' types instead"); if (!qemu_opts_parse_noisily(qemu_find_opts("mon"), optarg, true)) { exit(1); -- 2.54.0