1be8d8537SStefan Hajnoczi /* 2be8d8537SStefan Hajnoczi * Event loop thread 3be8d8537SStefan Hajnoczi * 4c3033fd3SEric Blake * Copyright Red Hat Inc., 2013, 2020 5be8d8537SStefan Hajnoczi * 6be8d8537SStefan Hajnoczi * Authors: 7be8d8537SStefan Hajnoczi * Stefan Hajnoczi <stefanha@redhat.com> 8be8d8537SStefan Hajnoczi * 9be8d8537SStefan Hajnoczi * This work is licensed under the terms of the GNU GPL, version 2 or later. 10be8d8537SStefan Hajnoczi * See the COPYING file in the top-level directory. 11be8d8537SStefan Hajnoczi * 12be8d8537SStefan Hajnoczi */ 13be8d8537SStefan Hajnoczi 14d38ea87aSPeter Maydell #include "qemu/osdep.h" 15be8d8537SStefan Hajnoczi #include "qom/object.h" 16be8d8537SStefan Hajnoczi #include "qom/object_interfaces.h" 17be8d8537SStefan Hajnoczi #include "qemu/module.h" 18be8d8537SStefan Hajnoczi #include "block/aio.h" 19d16341faSPaolo Bonzini #include "block/block.h" 207d5983e3SNicolas Saenz Julienne #include "sysemu/event-loop-base.h" 21be8d8537SStefan Hajnoczi #include "sysemu/iothread.h" 22e688df6bSMarkus Armbruster #include "qapi/error.h" 23112ed241SMarkus Armbruster #include "qapi/qapi-commands-misc.h" 242f78e491SChrysostomos Nanakos #include "qemu/error-report.h" 25ab28bd23SPaolo Bonzini #include "qemu/rcu.h" 26e4370165SPaolo Bonzini #include "qemu/main-loop.h" 27be8d8537SStefan Hajnoczi 28be8d8537SStefan Hajnoczi 2990c558beSPeter Xu #ifdef CONFIG_POSIX 30cdd7abfdSStefan Hajnoczi /* Benchmark results from 2016 on NVMe SSD drives show max polling times around 31cdd7abfdSStefan Hajnoczi * 16-32 microseconds yield IOPS improvements for both iodepth=1 and iodepth=32 32cdd7abfdSStefan Hajnoczi * workloads. 33cdd7abfdSStefan Hajnoczi */ 34cdd7abfdSStefan Hajnoczi #define IOTHREAD_POLL_MAX_NS_DEFAULT 32768ULL 3590c558beSPeter Xu #else 3690c558beSPeter Xu #define IOTHREAD_POLL_MAX_NS_DEFAULT 0ULL 3790c558beSPeter Xu #endif 38cdd7abfdSStefan Hajnoczi 39be8d8537SStefan Hajnoczi static void *iothread_run(void *opaque) 40be8d8537SStefan Hajnoczi { 41be8d8537SStefan Hajnoczi IOThread *iothread = opaque; 42be8d8537SStefan Hajnoczi 43ab28bd23SPaolo Bonzini rcu_register_thread(); 44b60ec76aSPeter Xu /* 45b60ec76aSPeter Xu * g_main_context_push_thread_default() must be called before anything 46b60ec76aSPeter Xu * in this new thread uses glib. 47b60ec76aSPeter Xu */ 48b60ec76aSPeter Xu g_main_context_push_thread_default(iothread->worker_context); 495f50be9bSPaolo Bonzini qemu_set_current_aio_context(iothread->ctx); 5088eb7c29SStefan Hajnoczi iothread->thread_id = qemu_get_thread_id(); 5121c4d15bSPeter Xu qemu_sem_post(&iothread->init_done_sem); 5288eb7c29SStefan Hajnoczi 532362a28eSStefan Hajnoczi while (iothread->running) { 546ca20620SPeter Xu /* 556ca20620SPeter Xu * Note: from functional-wise the g_main_loop_run() below can 566ca20620SPeter Xu * already cover the aio_poll() events, but we can't run the 576ca20620SPeter Xu * main loop unconditionally because explicit aio_poll() here 586ca20620SPeter Xu * is faster than g_main_loop_run() when we do not need the 596ca20620SPeter Xu * gcontext at all (e.g., pure block layer iothreads). In 606ca20620SPeter Xu * other words, when we want to run the gcontext with the 616ca20620SPeter Xu * iothread we need to pay some performance for functionality. 626ca20620SPeter Xu */ 6365c1b5b6SPaolo Bonzini aio_poll(iothread->ctx, true); 64329163cbSWang Yong 656c95363dSPeter Xu /* 666c95363dSPeter Xu * We must check the running state again in case it was 676c95363dSPeter Xu * changed in previous aio_poll() 686c95363dSPeter Xu */ 69d73415a3SStefan Hajnoczi if (iothread->running && qatomic_read(&iothread->run_gcontext)) { 70329163cbSWang Yong g_main_loop_run(iothread->main_loop); 71329163cbSWang Yong } 72be8d8537SStefan Hajnoczi } 73ab28bd23SPaolo Bonzini 74b60ec76aSPeter Xu g_main_context_pop_thread_default(iothread->worker_context); 75ab28bd23SPaolo Bonzini rcu_unregister_thread(); 76be8d8537SStefan Hajnoczi return NULL; 77be8d8537SStefan Hajnoczi } 78be8d8537SStefan Hajnoczi 792362a28eSStefan Hajnoczi /* Runs in iothread_run() thread */ 802362a28eSStefan Hajnoczi static void iothread_stop_bh(void *opaque) 812362a28eSStefan Hajnoczi { 822362a28eSStefan Hajnoczi IOThread *iothread = opaque; 832362a28eSStefan Hajnoczi 842362a28eSStefan Hajnoczi iothread->running = false; /* stop iothread_run() */ 852362a28eSStefan Hajnoczi 862362a28eSStefan Hajnoczi if (iothread->main_loop) { 872362a28eSStefan Hajnoczi g_main_loop_quit(iothread->main_loop); 882362a28eSStefan Hajnoczi } 892362a28eSStefan Hajnoczi } 902362a28eSStefan Hajnoczi 9182d90705SPeter Xu void iothread_stop(IOThread *iothread) 92be8d8537SStefan Hajnoczi { 9382d90705SPeter Xu if (!iothread->ctx || iothread->stopping) { 9482d90705SPeter Xu return; 952f78e491SChrysostomos Nanakos } 96be8d8537SStefan Hajnoczi iothread->stopping = true; 972362a28eSStefan Hajnoczi aio_bh_schedule_oneshot(iothread->ctx, iothread_stop_bh, iothread); 98be8d8537SStefan Hajnoczi qemu_thread_join(&iothread->thread); 9982d90705SPeter Xu } 10082d90705SPeter Xu 101cdd7abfdSStefan Hajnoczi static void iothread_instance_init(Object *obj) 102cdd7abfdSStefan Hajnoczi { 103cdd7abfdSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 104cdd7abfdSStefan Hajnoczi 105cdd7abfdSStefan Hajnoczi iothread->poll_max_ns = IOTHREAD_POLL_MAX_NS_DEFAULT; 10614a2d118SMarc-André Lureau iothread->thread_id = -1; 10721c4d15bSPeter Xu qemu_sem_init(&iothread->init_done_sem, 0); 108b506e0f1SPeter Xu /* By default, we don't run gcontext */ 109d73415a3SStefan Hajnoczi qatomic_set(&iothread->run_gcontext, 0); 110cdd7abfdSStefan Hajnoczi } 111cdd7abfdSStefan Hajnoczi 112dce8921bSFam Zheng static void iothread_instance_finalize(Object *obj) 113dce8921bSFam Zheng { 114dce8921bSFam Zheng IOThread *iothread = IOTHREAD(obj); 115dce8921bSFam Zheng 11682d90705SPeter Xu iothread_stop(iothread); 11714a2d118SMarc-André Lureau 11815544349SPeter Xu /* 11915544349SPeter Xu * Before glib2 2.33.10, there is a glib2 bug that GSource context 12015544349SPeter Xu * pointer may not be cleared even if the context has already been 12115544349SPeter Xu * destroyed (while it should). Here let's free the AIO context 12215544349SPeter Xu * earlier to bypass that glib bug. 12315544349SPeter Xu * 12415544349SPeter Xu * We can remove this comment after the minimum supported glib2 12515544349SPeter Xu * version boosts to 2.33.10. Before that, let's free the 12615544349SPeter Xu * GSources first before destroying any GMainContext. 12715544349SPeter Xu */ 12815544349SPeter Xu if (iothread->ctx) { 12915544349SPeter Xu aio_context_unref(iothread->ctx); 13015544349SPeter Xu iothread->ctx = NULL; 13115544349SPeter Xu } 1325b3ac23fSPeter Xu if (iothread->worker_context) { 1335b3ac23fSPeter Xu g_main_context_unref(iothread->worker_context); 1345b3ac23fSPeter Xu iothread->worker_context = NULL; 1350bd2d233SPeter Xu g_main_loop_unref(iothread->main_loop); 1360bd2d233SPeter Xu iothread->main_loop = NULL; 1375b3ac23fSPeter Xu } 13821c4d15bSPeter Xu qemu_sem_destroy(&iothread->init_done_sem); 139be8d8537SStefan Hajnoczi } 140be8d8537SStefan Hajnoczi 1411f14c914SFabiano Rosas static void iothread_init_gcontext(IOThread *iothread, const char *thread_name) 142b506e0f1SPeter Xu { 143b506e0f1SPeter Xu GSource *source; 1441f14c914SFabiano Rosas g_autofree char *name = g_strdup_printf("%s aio-context", thread_name); 145b506e0f1SPeter Xu 146b506e0f1SPeter Xu iothread->worker_context = g_main_context_new(); 147b506e0f1SPeter Xu source = aio_get_g_source(iothread_get_aio_context(iothread)); 1481f14c914SFabiano Rosas g_source_set_name(source, name); 149b506e0f1SPeter Xu g_source_attach(source, iothread->worker_context); 150b506e0f1SPeter Xu g_source_unref(source); 1510bd2d233SPeter Xu iothread->main_loop = g_main_loop_new(iothread->worker_context, TRUE); 152b506e0f1SPeter Xu } 153b506e0f1SPeter Xu 1547d5983e3SNicolas Saenz Julienne static void iothread_set_aio_context_params(EventLoopBase *base, Error **errp) 1551793ad02SStefano Garzarella { 1561793ad02SStefano Garzarella ERRP_GUARD(); 15705e385d2SMarkus Armbruster IOThread *iothread = IOTHREAD(base); 1581793ad02SStefano Garzarella 1597d5983e3SNicolas Saenz Julienne if (!iothread->ctx) { 1607d5983e3SNicolas Saenz Julienne return; 1617d5983e3SNicolas Saenz Julienne } 1627d5983e3SNicolas Saenz Julienne 1631793ad02SStefano Garzarella aio_context_set_poll_params(iothread->ctx, 1641793ad02SStefano Garzarella iothread->poll_max_ns, 1651793ad02SStefano Garzarella iothread->poll_grow, 1661793ad02SStefano Garzarella iothread->poll_shrink, 1671793ad02SStefano Garzarella errp); 1681793ad02SStefano Garzarella if (*errp) { 1691793ad02SStefano Garzarella return; 1701793ad02SStefano Garzarella } 1711793ad02SStefano Garzarella 1721793ad02SStefano Garzarella aio_context_set_aio_params(iothread->ctx, 173*897a06c6SPhilippe Mathieu-Daudé iothread->parent_obj.aio_max_batch); 17471ad4713SNicolas Saenz Julienne 17571ad4713SNicolas Saenz Julienne aio_context_set_thread_pool_params(iothread->ctx, base->thread_pool_min, 17671ad4713SNicolas Saenz Julienne base->thread_pool_max, errp); 1771793ad02SStefano Garzarella } 1781793ad02SStefano Garzarella 1797d5983e3SNicolas Saenz Julienne 1807d5983e3SNicolas Saenz Julienne static void iothread_init(EventLoopBase *base, Error **errp) 181be8d8537SStefan Hajnoczi { 1822f78e491SChrysostomos Nanakos Error *local_error = NULL; 1837d5983e3SNicolas Saenz Julienne IOThread *iothread = IOTHREAD(base); 1841f14c914SFabiano Rosas g_autofree char *thread_name = NULL; 185be8d8537SStefan Hajnoczi 186be8d8537SStefan Hajnoczi iothread->stopping = false; 1872362a28eSStefan Hajnoczi iothread->running = true; 188668f62ecSMarkus Armbruster iothread->ctx = aio_context_new(errp); 1892f78e491SChrysostomos Nanakos if (!iothread->ctx) { 1902f78e491SChrysostomos Nanakos return; 1912f78e491SChrysostomos Nanakos } 19288eb7c29SStefan Hajnoczi 1931f14c914SFabiano Rosas thread_name = g_strdup_printf("IO %s", 1941f14c914SFabiano Rosas object_get_canonical_path_component(OBJECT(base))); 1951f14c914SFabiano Rosas 196b506e0f1SPeter Xu /* 197b506e0f1SPeter Xu * Init one GMainContext for the iothread unconditionally, even if 198b506e0f1SPeter Xu * it's not used 199b506e0f1SPeter Xu */ 2001f14c914SFabiano Rosas iothread_init_gcontext(iothread, thread_name); 201b506e0f1SPeter Xu 2027d5983e3SNicolas Saenz Julienne iothread_set_aio_context_params(base, &local_error); 2030d9d86fbSStefan Hajnoczi if (local_error) { 2040d9d86fbSStefan Hajnoczi error_propagate(errp, local_error); 2050d9d86fbSStefan Hajnoczi aio_context_unref(iothread->ctx); 2060d9d86fbSStefan Hajnoczi iothread->ctx = NULL; 2070d9d86fbSStefan Hajnoczi return; 2080d9d86fbSStefan Hajnoczi } 2090d9d86fbSStefan Hajnoczi 210be8d8537SStefan Hajnoczi /* This assumes we are called from a thread with useful CPU affinity for us 211be8d8537SStefan Hajnoczi * to inherit. 212be8d8537SStefan Hajnoczi */ 213d21e8776SPaolo Bonzini qemu_thread_create(&iothread->thread, thread_name, iothread_run, 214be8d8537SStefan Hajnoczi iothread, QEMU_THREAD_JOINABLE); 21588eb7c29SStefan Hajnoczi 21688eb7c29SStefan Hajnoczi /* Wait for initialization to complete */ 21788eb7c29SStefan Hajnoczi while (iothread->thread_id == -1) { 21821c4d15bSPeter Xu qemu_sem_wait(&iothread->init_done_sem); 21988eb7c29SStefan Hajnoczi } 220be8d8537SStefan Hajnoczi } 221be8d8537SStefan Hajnoczi 2225e5db499SStefan Hajnoczi typedef struct { 2235e5db499SStefan Hajnoczi const char *name; 2245e5db499SStefan Hajnoczi ptrdiff_t offset; /* field's byte offset in IOThread struct */ 225f0ed36a6SStefano Garzarella } IOThreadParamInfo; 2265e5db499SStefan Hajnoczi 227f0ed36a6SStefano Garzarella static IOThreadParamInfo poll_max_ns_info = { 2285e5db499SStefan Hajnoczi "poll-max-ns", offsetof(IOThread, poll_max_ns), 2295e5db499SStefan Hajnoczi }; 230f0ed36a6SStefano Garzarella static IOThreadParamInfo poll_grow_info = { 2315e5db499SStefan Hajnoczi "poll-grow", offsetof(IOThread, poll_grow), 2325e5db499SStefan Hajnoczi }; 233f0ed36a6SStefano Garzarella static IOThreadParamInfo poll_shrink_info = { 2345e5db499SStefan Hajnoczi "poll-shrink", offsetof(IOThread, poll_shrink), 2355e5db499SStefan Hajnoczi }; 2365e5db499SStefan Hajnoczi 2370445409dSStefano Garzarella static void iothread_get_param(Object *obj, Visitor *v, 2381cc7eadaSStefano Garzarella const char *name, IOThreadParamInfo *info, Error **errp) 2390d9d86fbSStefan Hajnoczi { 2400d9d86fbSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 2415e5db499SStefan Hajnoczi int64_t *field = (void *)iothread + info->offset; 2420d9d86fbSStefan Hajnoczi 2435e5db499SStefan Hajnoczi visit_type_int64(v, name, field, errp); 2440d9d86fbSStefan Hajnoczi } 2450d9d86fbSStefan Hajnoczi 2460445409dSStefano Garzarella static bool iothread_set_param(Object *obj, Visitor *v, 2471cc7eadaSStefano Garzarella const char *name, IOThreadParamInfo *info, Error **errp) 2480d9d86fbSStefan Hajnoczi { 2490d9d86fbSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 2505e5db499SStefan Hajnoczi int64_t *field = (void *)iothread + info->offset; 2510d9d86fbSStefan Hajnoczi int64_t value; 2520d9d86fbSStefan Hajnoczi 253668f62ecSMarkus Armbruster if (!visit_type_int64(v, name, &value, errp)) { 2540445409dSStefano Garzarella return false; 2550d9d86fbSStefan Hajnoczi } 2560d9d86fbSStefan Hajnoczi 2570d9d86fbSStefan Hajnoczi if (value < 0) { 258dcfe4805SMarkus Armbruster error_setg(errp, "%s value must be in range [0, %" PRId64 "]", 2595e5db499SStefan Hajnoczi info->name, INT64_MAX); 2600445409dSStefano Garzarella return false; 2610d9d86fbSStefan Hajnoczi } 2620d9d86fbSStefan Hajnoczi 2635e5db499SStefan Hajnoczi *field = value; 2640d9d86fbSStefan Hajnoczi 2650445409dSStefano Garzarella return true; 2660445409dSStefano Garzarella } 2670445409dSStefano Garzarella 2680445409dSStefano Garzarella static void iothread_get_poll_param(Object *obj, Visitor *v, 2690445409dSStefano Garzarella const char *name, void *opaque, Error **errp) 2700445409dSStefano Garzarella { 2711cc7eadaSStefano Garzarella IOThreadParamInfo *info = opaque; 2720445409dSStefano Garzarella 2731cc7eadaSStefano Garzarella iothread_get_param(obj, v, name, info, errp); 2740445409dSStefano Garzarella } 2750445409dSStefano Garzarella 2760445409dSStefano Garzarella static void iothread_set_poll_param(Object *obj, Visitor *v, 2770445409dSStefano Garzarella const char *name, void *opaque, Error **errp) 2780445409dSStefano Garzarella { 2790445409dSStefano Garzarella IOThread *iothread = IOTHREAD(obj); 2801cc7eadaSStefano Garzarella IOThreadParamInfo *info = opaque; 2810445409dSStefano Garzarella 2821cc7eadaSStefano Garzarella if (!iothread_set_param(obj, v, name, info, errp)) { 2830445409dSStefano Garzarella return; 2840445409dSStefano Garzarella } 2850445409dSStefano Garzarella 2860d9d86fbSStefan Hajnoczi if (iothread->ctx) { 2875e5db499SStefan Hajnoczi aio_context_set_poll_params(iothread->ctx, 2885e5db499SStefan Hajnoczi iothread->poll_max_ns, 2895e5db499SStefan Hajnoczi iothread->poll_grow, 2905e5db499SStefan Hajnoczi iothread->poll_shrink, 291dcfe4805SMarkus Armbruster errp); 2920d9d86fbSStefan Hajnoczi } 2930d9d86fbSStefan Hajnoczi } 2940d9d86fbSStefan Hajnoczi 295be8d8537SStefan Hajnoczi static void iothread_class_init(ObjectClass *klass, void *class_data) 296be8d8537SStefan Hajnoczi { 2977d5983e3SNicolas Saenz Julienne EventLoopBaseClass *bc = EVENT_LOOP_BASE_CLASS(klass); 2987d5983e3SNicolas Saenz Julienne 2997d5983e3SNicolas Saenz Julienne bc->init = iothread_init; 3007d5983e3SNicolas Saenz Julienne bc->update_params = iothread_set_aio_context_params; 3010d9d86fbSStefan Hajnoczi 3020d9d86fbSStefan Hajnoczi object_class_property_add(klass, "poll-max-ns", "int", 3035e5db499SStefan Hajnoczi iothread_get_poll_param, 3045e5db499SStefan Hajnoczi iothread_set_poll_param, 305d2623129SMarkus Armbruster NULL, &poll_max_ns_info); 3065e5db499SStefan Hajnoczi object_class_property_add(klass, "poll-grow", "int", 3075e5db499SStefan Hajnoczi iothread_get_poll_param, 3085e5db499SStefan Hajnoczi iothread_set_poll_param, 309d2623129SMarkus Armbruster NULL, &poll_grow_info); 3105e5db499SStefan Hajnoczi object_class_property_add(klass, "poll-shrink", "int", 3115e5db499SStefan Hajnoczi iothread_get_poll_param, 3125e5db499SStefan Hajnoczi iothread_set_poll_param, 313d2623129SMarkus Armbruster NULL, &poll_shrink_info); 314be8d8537SStefan Hajnoczi } 315be8d8537SStefan Hajnoczi 316be8d8537SStefan Hajnoczi static const TypeInfo iothread_info = { 317be8d8537SStefan Hajnoczi .name = TYPE_IOTHREAD, 3187d5983e3SNicolas Saenz Julienne .parent = TYPE_EVENT_LOOP_BASE, 319be8d8537SStefan Hajnoczi .class_init = iothread_class_init, 320be8d8537SStefan Hajnoczi .instance_size = sizeof(IOThread), 321cdd7abfdSStefan Hajnoczi .instance_init = iothread_instance_init, 322be8d8537SStefan Hajnoczi .instance_finalize = iothread_instance_finalize, 323be8d8537SStefan Hajnoczi }; 324be8d8537SStefan Hajnoczi 325be8d8537SStefan Hajnoczi static void iothread_register_types(void) 326be8d8537SStefan Hajnoczi { 327be8d8537SStefan Hajnoczi type_register_static(&iothread_info); 328be8d8537SStefan Hajnoczi } 329be8d8537SStefan Hajnoczi 330be8d8537SStefan Hajnoczi type_init(iothread_register_types) 331be8d8537SStefan Hajnoczi 332be8d8537SStefan Hajnoczi char *iothread_get_id(IOThread *iothread) 333be8d8537SStefan Hajnoczi { 3347a309cc9SMarkus Armbruster return g_strdup(object_get_canonical_path_component(OBJECT(iothread))); 335be8d8537SStefan Hajnoczi } 336be8d8537SStefan Hajnoczi 337be8d8537SStefan Hajnoczi AioContext *iothread_get_aio_context(IOThread *iothread) 338be8d8537SStefan Hajnoczi { 339be8d8537SStefan Hajnoczi return iothread->ctx; 340be8d8537SStefan Hajnoczi } 341dc3dd0d2SStefan Hajnoczi 342dc3dd0d2SStefan Hajnoczi static int query_one_iothread(Object *object, void *opaque) 343dc3dd0d2SStefan Hajnoczi { 344c3033fd3SEric Blake IOThreadInfoList ***tail = opaque; 345dc3dd0d2SStefan Hajnoczi IOThreadInfo *info; 346dc3dd0d2SStefan Hajnoczi IOThread *iothread; 347dc3dd0d2SStefan Hajnoczi 348dc3dd0d2SStefan Hajnoczi iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD); 349dc3dd0d2SStefan Hajnoczi if (!iothread) { 350dc3dd0d2SStefan Hajnoczi return 0; 351dc3dd0d2SStefan Hajnoczi } 352dc3dd0d2SStefan Hajnoczi 353dc3dd0d2SStefan Hajnoczi info = g_new0(IOThreadInfo, 1); 354dc3dd0d2SStefan Hajnoczi info->id = iothread_get_id(iothread); 355dc3dd0d2SStefan Hajnoczi info->thread_id = iothread->thread_id; 3565fc00480SPavel Hrdina info->poll_max_ns = iothread->poll_max_ns; 3575fc00480SPavel Hrdina info->poll_grow = iothread->poll_grow; 3585fc00480SPavel Hrdina info->poll_shrink = iothread->poll_shrink; 3597d5983e3SNicolas Saenz Julienne info->aio_max_batch = iothread->parent_obj.aio_max_batch; 360dc3dd0d2SStefan Hajnoczi 361c3033fd3SEric Blake QAPI_LIST_APPEND(*tail, info); 362dc3dd0d2SStefan Hajnoczi return 0; 363dc3dd0d2SStefan Hajnoczi } 364dc3dd0d2SStefan Hajnoczi 365dc3dd0d2SStefan Hajnoczi IOThreadInfoList *qmp_query_iothreads(Error **errp) 366dc3dd0d2SStefan Hajnoczi { 367dc3dd0d2SStefan Hajnoczi IOThreadInfoList *head = NULL; 368dc3dd0d2SStefan Hajnoczi IOThreadInfoList **prev = &head; 369bc2256c4SDaniel P. Berrange Object *container = object_get_objects_root(); 370dc3dd0d2SStefan Hajnoczi 371dc3dd0d2SStefan Hajnoczi object_child_foreach(container, query_one_iothread, &prev); 372dc3dd0d2SStefan Hajnoczi return head; 373dc3dd0d2SStefan Hajnoczi } 374dce8921bSFam Zheng 375329163cbSWang Yong GMainContext *iothread_get_g_main_context(IOThread *iothread) 376329163cbSWang Yong { 377d73415a3SStefan Hajnoczi qatomic_set(&iothread->run_gcontext, 1); 378b506e0f1SPeter Xu aio_notify(iothread->ctx); 379329163cbSWang Yong return iothread->worker_context; 380329163cbSWang Yong } 3810173e21bSPeter Xu 3820173e21bSPeter Xu IOThread *iothread_create(const char *id, Error **errp) 3830173e21bSPeter Xu { 3840173e21bSPeter Xu Object *obj; 3850173e21bSPeter Xu 3860173e21bSPeter Xu obj = object_new_with_props(TYPE_IOTHREAD, 3870173e21bSPeter Xu object_get_internal_root(), 3880173e21bSPeter Xu id, errp, NULL); 3890173e21bSPeter Xu 3900173e21bSPeter Xu return IOTHREAD(obj); 3910173e21bSPeter Xu } 3920173e21bSPeter Xu 3930173e21bSPeter Xu void iothread_destroy(IOThread *iothread) 3940173e21bSPeter Xu { 3950173e21bSPeter Xu object_unparent(OBJECT(iothread)); 3960173e21bSPeter Xu } 397fbcc6923SStefan Hajnoczi 398fbcc6923SStefan Hajnoczi /* Lookup IOThread by its id. Only finds user-created objects, not internal 399fbcc6923SStefan Hajnoczi * iothread_create() objects. */ 400fbcc6923SStefan Hajnoczi IOThread *iothread_by_id(const char *id) 401fbcc6923SStefan Hajnoczi { 402fbcc6923SStefan Hajnoczi return IOTHREAD(object_resolve_path_type(id, TYPE_IOTHREAD, NULL)); 403fbcc6923SStefan Hajnoczi } 404ad22c308SElena Ufimtseva 405ad22c308SElena Ufimtseva bool qemu_in_iothread(void) 406ad22c308SElena Ufimtseva { 407ad22c308SElena Ufimtseva return qemu_get_current_aio_context() == qemu_get_aio_context() ? 408ad22c308SElena Ufimtseva false : true; 409ad22c308SElena Ufimtseva } 410