1be8d8537SStefan Hajnoczi /* 2be8d8537SStefan Hajnoczi * Event loop thread 3be8d8537SStefan Hajnoczi * 4be8d8537SStefan Hajnoczi * Copyright Red Hat Inc., 2013 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" 20be8d8537SStefan Hajnoczi #include "sysemu/iothread.h" 21dc3dd0d2SStefan Hajnoczi #include "qmp-commands.h" 222f78e491SChrysostomos Nanakos #include "qemu/error-report.h" 23ab28bd23SPaolo Bonzini #include "qemu/rcu.h" 24e4370165SPaolo Bonzini #include "qemu/main-loop.h" 25be8d8537SStefan Hajnoczi 26be8d8537SStefan Hajnoczi typedef ObjectClass IOThreadClass; 27be8d8537SStefan Hajnoczi 28be8d8537SStefan Hajnoczi #define IOTHREAD_GET_CLASS(obj) \ 29be8d8537SStefan Hajnoczi OBJECT_GET_CLASS(IOThreadClass, obj, TYPE_IOTHREAD) 30be8d8537SStefan Hajnoczi #define IOTHREAD_CLASS(klass) \ 31be8d8537SStefan Hajnoczi OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD) 32be8d8537SStefan Hajnoczi 33cdd7abfdSStefan Hajnoczi /* Benchmark results from 2016 on NVMe SSD drives show max polling times around 34cdd7abfdSStefan Hajnoczi * 16-32 microseconds yield IOPS improvements for both iodepth=1 and iodepth=32 35cdd7abfdSStefan Hajnoczi * workloads. 36cdd7abfdSStefan Hajnoczi */ 37cdd7abfdSStefan Hajnoczi #define IOTHREAD_POLL_MAX_NS_DEFAULT 32768ULL 38cdd7abfdSStefan Hajnoczi 39e4370165SPaolo Bonzini static __thread IOThread *my_iothread; 40e4370165SPaolo Bonzini 41e4370165SPaolo Bonzini AioContext *qemu_get_current_aio_context(void) 42e4370165SPaolo Bonzini { 43e4370165SPaolo Bonzini return my_iothread ? my_iothread->ctx : qemu_get_aio_context(); 44e4370165SPaolo Bonzini } 45e4370165SPaolo Bonzini 46be8d8537SStefan Hajnoczi static void *iothread_run(void *opaque) 47be8d8537SStefan Hajnoczi { 48be8d8537SStefan Hajnoczi IOThread *iothread = opaque; 49be8d8537SStefan Hajnoczi 50ab28bd23SPaolo Bonzini rcu_register_thread(); 51ab28bd23SPaolo Bonzini 52e4370165SPaolo Bonzini my_iothread = iothread; 5388eb7c29SStefan Hajnoczi qemu_mutex_lock(&iothread->init_done_lock); 5488eb7c29SStefan Hajnoczi iothread->thread_id = qemu_get_thread_id(); 5588eb7c29SStefan Hajnoczi qemu_cond_signal(&iothread->init_done_cond); 5688eb7c29SStefan Hajnoczi qemu_mutex_unlock(&iothread->init_done_lock); 5788eb7c29SStefan Hajnoczi 5865c1b5b6SPaolo Bonzini while (!atomic_read(&iothread->stopping)) { 5965c1b5b6SPaolo Bonzini aio_poll(iothread->ctx, true); 60*329163cbSWang Yong 61*329163cbSWang Yong if (atomic_read(&iothread->worker_context)) { 62*329163cbSWang Yong GMainLoop *loop; 63*329163cbSWang Yong 64*329163cbSWang Yong g_main_context_push_thread_default(iothread->worker_context); 65*329163cbSWang Yong iothread->main_loop = 66*329163cbSWang Yong g_main_loop_new(iothread->worker_context, TRUE); 67*329163cbSWang Yong loop = iothread->main_loop; 68*329163cbSWang Yong 69*329163cbSWang Yong g_main_loop_run(iothread->main_loop); 70*329163cbSWang Yong iothread->main_loop = NULL; 71*329163cbSWang Yong g_main_loop_unref(loop); 72*329163cbSWang Yong 73*329163cbSWang Yong g_main_context_pop_thread_default(iothread->worker_context); 74*329163cbSWang Yong g_main_context_unref(iothread->worker_context); 75*329163cbSWang Yong iothread->worker_context = NULL; 76*329163cbSWang Yong } 77be8d8537SStefan Hajnoczi } 78ab28bd23SPaolo Bonzini 79ab28bd23SPaolo Bonzini rcu_unregister_thread(); 80be8d8537SStefan Hajnoczi return NULL; 81be8d8537SStefan Hajnoczi } 82be8d8537SStefan Hajnoczi 83dce8921bSFam Zheng static int iothread_stop(Object *object, void *opaque) 84be8d8537SStefan Hajnoczi { 85dce8921bSFam Zheng IOThread *iothread; 86be8d8537SStefan Hajnoczi 87dce8921bSFam Zheng iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD); 88dce8921bSFam Zheng if (!iothread || !iothread->ctx) { 89dce8921bSFam Zheng return 0; 902f78e491SChrysostomos Nanakos } 91be8d8537SStefan Hajnoczi iothread->stopping = true; 92be8d8537SStefan Hajnoczi aio_notify(iothread->ctx); 93*329163cbSWang Yong if (atomic_read(&iothread->main_loop)) { 94*329163cbSWang Yong g_main_loop_quit(iothread->main_loop); 95*329163cbSWang Yong } 96be8d8537SStefan Hajnoczi qemu_thread_join(&iothread->thread); 97dce8921bSFam Zheng return 0; 98dce8921bSFam Zheng } 99dce8921bSFam Zheng 100cdd7abfdSStefan Hajnoczi static void iothread_instance_init(Object *obj) 101cdd7abfdSStefan Hajnoczi { 102cdd7abfdSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 103cdd7abfdSStefan Hajnoczi 104cdd7abfdSStefan Hajnoczi iothread->poll_max_ns = IOTHREAD_POLL_MAX_NS_DEFAULT; 105cdd7abfdSStefan Hajnoczi } 106cdd7abfdSStefan Hajnoczi 107dce8921bSFam Zheng static void iothread_instance_finalize(Object *obj) 108dce8921bSFam Zheng { 109dce8921bSFam Zheng IOThread *iothread = IOTHREAD(obj); 110dce8921bSFam Zheng 111dce8921bSFam Zheng iothread_stop(obj, NULL); 11288eb7c29SStefan Hajnoczi qemu_cond_destroy(&iothread->init_done_cond); 11388eb7c29SStefan Hajnoczi qemu_mutex_destroy(&iothread->init_done_lock); 114eb7b5c35SLin Ma if (!iothread->ctx) { 115eb7b5c35SLin Ma return; 116eb7b5c35SLin Ma } 117be8d8537SStefan Hajnoczi aio_context_unref(iothread->ctx); 118be8d8537SStefan Hajnoczi } 119be8d8537SStefan Hajnoczi 120be8d8537SStefan Hajnoczi static void iothread_complete(UserCreatable *obj, Error **errp) 121be8d8537SStefan Hajnoczi { 1222f78e491SChrysostomos Nanakos Error *local_error = NULL; 123be8d8537SStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 124d21e8776SPaolo Bonzini char *name, *thread_name; 125be8d8537SStefan Hajnoczi 126be8d8537SStefan Hajnoczi iothread->stopping = false; 12788eb7c29SStefan Hajnoczi iothread->thread_id = -1; 1282f78e491SChrysostomos Nanakos iothread->ctx = aio_context_new(&local_error); 1292f78e491SChrysostomos Nanakos if (!iothread->ctx) { 1302f78e491SChrysostomos Nanakos error_propagate(errp, local_error); 1312f78e491SChrysostomos Nanakos return; 1322f78e491SChrysostomos Nanakos } 13388eb7c29SStefan Hajnoczi 1345e5db499SStefan Hajnoczi aio_context_set_poll_params(iothread->ctx, 1355e5db499SStefan Hajnoczi iothread->poll_max_ns, 1365e5db499SStefan Hajnoczi iothread->poll_grow, 1375e5db499SStefan Hajnoczi iothread->poll_shrink, 1380d9d86fbSStefan Hajnoczi &local_error); 1390d9d86fbSStefan Hajnoczi if (local_error) { 1400d9d86fbSStefan Hajnoczi error_propagate(errp, local_error); 1410d9d86fbSStefan Hajnoczi aio_context_unref(iothread->ctx); 1420d9d86fbSStefan Hajnoczi iothread->ctx = NULL; 1430d9d86fbSStefan Hajnoczi return; 1440d9d86fbSStefan Hajnoczi } 1450d9d86fbSStefan Hajnoczi 14688eb7c29SStefan Hajnoczi qemu_mutex_init(&iothread->init_done_lock); 14788eb7c29SStefan Hajnoczi qemu_cond_init(&iothread->init_done_cond); 148*329163cbSWang Yong iothread->once = (GOnce) G_ONCE_INIT; 149be8d8537SStefan Hajnoczi 150be8d8537SStefan Hajnoczi /* This assumes we are called from a thread with useful CPU affinity for us 151be8d8537SStefan Hajnoczi * to inherit. 152be8d8537SStefan Hajnoczi */ 153d21e8776SPaolo Bonzini name = object_get_canonical_path_component(OBJECT(obj)); 154d21e8776SPaolo Bonzini thread_name = g_strdup_printf("IO %s", name); 155d21e8776SPaolo Bonzini qemu_thread_create(&iothread->thread, thread_name, iothread_run, 156be8d8537SStefan Hajnoczi iothread, QEMU_THREAD_JOINABLE); 157d21e8776SPaolo Bonzini g_free(thread_name); 158d21e8776SPaolo Bonzini g_free(name); 15988eb7c29SStefan Hajnoczi 16088eb7c29SStefan Hajnoczi /* Wait for initialization to complete */ 16188eb7c29SStefan Hajnoczi qemu_mutex_lock(&iothread->init_done_lock); 16288eb7c29SStefan Hajnoczi while (iothread->thread_id == -1) { 16388eb7c29SStefan Hajnoczi qemu_cond_wait(&iothread->init_done_cond, 16488eb7c29SStefan Hajnoczi &iothread->init_done_lock); 16588eb7c29SStefan Hajnoczi } 16688eb7c29SStefan Hajnoczi qemu_mutex_unlock(&iothread->init_done_lock); 167be8d8537SStefan Hajnoczi } 168be8d8537SStefan Hajnoczi 1695e5db499SStefan Hajnoczi typedef struct { 1705e5db499SStefan Hajnoczi const char *name; 1715e5db499SStefan Hajnoczi ptrdiff_t offset; /* field's byte offset in IOThread struct */ 1725e5db499SStefan Hajnoczi } PollParamInfo; 1735e5db499SStefan Hajnoczi 1745e5db499SStefan Hajnoczi static PollParamInfo poll_max_ns_info = { 1755e5db499SStefan Hajnoczi "poll-max-ns", offsetof(IOThread, poll_max_ns), 1765e5db499SStefan Hajnoczi }; 1775e5db499SStefan Hajnoczi static PollParamInfo poll_grow_info = { 1785e5db499SStefan Hajnoczi "poll-grow", offsetof(IOThread, poll_grow), 1795e5db499SStefan Hajnoczi }; 1805e5db499SStefan Hajnoczi static PollParamInfo poll_shrink_info = { 1815e5db499SStefan Hajnoczi "poll-shrink", offsetof(IOThread, poll_shrink), 1825e5db499SStefan Hajnoczi }; 1835e5db499SStefan Hajnoczi 1845e5db499SStefan Hajnoczi static void iothread_get_poll_param(Object *obj, Visitor *v, 1850d9d86fbSStefan Hajnoczi const char *name, void *opaque, Error **errp) 1860d9d86fbSStefan Hajnoczi { 1870d9d86fbSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 1885e5db499SStefan Hajnoczi PollParamInfo *info = opaque; 1895e5db499SStefan Hajnoczi int64_t *field = (void *)iothread + info->offset; 1900d9d86fbSStefan Hajnoczi 1915e5db499SStefan Hajnoczi visit_type_int64(v, name, field, errp); 1920d9d86fbSStefan Hajnoczi } 1930d9d86fbSStefan Hajnoczi 1945e5db499SStefan Hajnoczi static void iothread_set_poll_param(Object *obj, Visitor *v, 1950d9d86fbSStefan Hajnoczi const char *name, void *opaque, Error **errp) 1960d9d86fbSStefan Hajnoczi { 1970d9d86fbSStefan Hajnoczi IOThread *iothread = IOTHREAD(obj); 1985e5db499SStefan Hajnoczi PollParamInfo *info = opaque; 1995e5db499SStefan Hajnoczi int64_t *field = (void *)iothread + info->offset; 2000d9d86fbSStefan Hajnoczi Error *local_err = NULL; 2010d9d86fbSStefan Hajnoczi int64_t value; 2020d9d86fbSStefan Hajnoczi 2030d9d86fbSStefan Hajnoczi visit_type_int64(v, name, &value, &local_err); 2040d9d86fbSStefan Hajnoczi if (local_err) { 2050d9d86fbSStefan Hajnoczi goto out; 2060d9d86fbSStefan Hajnoczi } 2070d9d86fbSStefan Hajnoczi 2080d9d86fbSStefan Hajnoczi if (value < 0) { 2095e5db499SStefan Hajnoczi error_setg(&local_err, "%s value must be in range [0, %"PRId64"]", 2105e5db499SStefan Hajnoczi info->name, INT64_MAX); 2110d9d86fbSStefan Hajnoczi goto out; 2120d9d86fbSStefan Hajnoczi } 2130d9d86fbSStefan Hajnoczi 2145e5db499SStefan Hajnoczi *field = value; 2150d9d86fbSStefan Hajnoczi 2160d9d86fbSStefan Hajnoczi if (iothread->ctx) { 2175e5db499SStefan Hajnoczi aio_context_set_poll_params(iothread->ctx, 2185e5db499SStefan Hajnoczi iothread->poll_max_ns, 2195e5db499SStefan Hajnoczi iothread->poll_grow, 2205e5db499SStefan Hajnoczi iothread->poll_shrink, 2215e5db499SStefan Hajnoczi &local_err); 2220d9d86fbSStefan Hajnoczi } 2230d9d86fbSStefan Hajnoczi 2240d9d86fbSStefan Hajnoczi out: 2250d9d86fbSStefan Hajnoczi error_propagate(errp, local_err); 2260d9d86fbSStefan Hajnoczi } 2270d9d86fbSStefan Hajnoczi 228be8d8537SStefan Hajnoczi static void iothread_class_init(ObjectClass *klass, void *class_data) 229be8d8537SStefan Hajnoczi { 230be8d8537SStefan Hajnoczi UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass); 231be8d8537SStefan Hajnoczi ucc->complete = iothread_complete; 2320d9d86fbSStefan Hajnoczi 2330d9d86fbSStefan Hajnoczi object_class_property_add(klass, "poll-max-ns", "int", 2345e5db499SStefan Hajnoczi iothread_get_poll_param, 2355e5db499SStefan Hajnoczi iothread_set_poll_param, 2365e5db499SStefan Hajnoczi NULL, &poll_max_ns_info, &error_abort); 2375e5db499SStefan Hajnoczi object_class_property_add(klass, "poll-grow", "int", 2385e5db499SStefan Hajnoczi iothread_get_poll_param, 2395e5db499SStefan Hajnoczi iothread_set_poll_param, 2405e5db499SStefan Hajnoczi NULL, &poll_grow_info, &error_abort); 2415e5db499SStefan Hajnoczi object_class_property_add(klass, "poll-shrink", "int", 2425e5db499SStefan Hajnoczi iothread_get_poll_param, 2435e5db499SStefan Hajnoczi iothread_set_poll_param, 2445e5db499SStefan Hajnoczi NULL, &poll_shrink_info, &error_abort); 245be8d8537SStefan Hajnoczi } 246be8d8537SStefan Hajnoczi 247be8d8537SStefan Hajnoczi static const TypeInfo iothread_info = { 248be8d8537SStefan Hajnoczi .name = TYPE_IOTHREAD, 249be8d8537SStefan Hajnoczi .parent = TYPE_OBJECT, 250be8d8537SStefan Hajnoczi .class_init = iothread_class_init, 251be8d8537SStefan Hajnoczi .instance_size = sizeof(IOThread), 252cdd7abfdSStefan Hajnoczi .instance_init = iothread_instance_init, 253be8d8537SStefan Hajnoczi .instance_finalize = iothread_instance_finalize, 254be8d8537SStefan Hajnoczi .interfaces = (InterfaceInfo[]) { 255be8d8537SStefan Hajnoczi {TYPE_USER_CREATABLE}, 256be8d8537SStefan Hajnoczi {} 257be8d8537SStefan Hajnoczi }, 258be8d8537SStefan Hajnoczi }; 259be8d8537SStefan Hajnoczi 260be8d8537SStefan Hajnoczi static void iothread_register_types(void) 261be8d8537SStefan Hajnoczi { 262be8d8537SStefan Hajnoczi type_register_static(&iothread_info); 263be8d8537SStefan Hajnoczi } 264be8d8537SStefan Hajnoczi 265be8d8537SStefan Hajnoczi type_init(iothread_register_types) 266be8d8537SStefan Hajnoczi 267be8d8537SStefan Hajnoczi char *iothread_get_id(IOThread *iothread) 268be8d8537SStefan Hajnoczi { 269be8d8537SStefan Hajnoczi return object_get_canonical_path_component(OBJECT(iothread)); 270be8d8537SStefan Hajnoczi } 271be8d8537SStefan Hajnoczi 272be8d8537SStefan Hajnoczi AioContext *iothread_get_aio_context(IOThread *iothread) 273be8d8537SStefan Hajnoczi { 274be8d8537SStefan Hajnoczi return iothread->ctx; 275be8d8537SStefan Hajnoczi } 276dc3dd0d2SStefan Hajnoczi 277dc3dd0d2SStefan Hajnoczi static int query_one_iothread(Object *object, void *opaque) 278dc3dd0d2SStefan Hajnoczi { 279dc3dd0d2SStefan Hajnoczi IOThreadInfoList ***prev = opaque; 280dc3dd0d2SStefan Hajnoczi IOThreadInfoList *elem; 281dc3dd0d2SStefan Hajnoczi IOThreadInfo *info; 282dc3dd0d2SStefan Hajnoczi IOThread *iothread; 283dc3dd0d2SStefan Hajnoczi 284dc3dd0d2SStefan Hajnoczi iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD); 285dc3dd0d2SStefan Hajnoczi if (!iothread) { 286dc3dd0d2SStefan Hajnoczi return 0; 287dc3dd0d2SStefan Hajnoczi } 288dc3dd0d2SStefan Hajnoczi 289dc3dd0d2SStefan Hajnoczi info = g_new0(IOThreadInfo, 1); 290dc3dd0d2SStefan Hajnoczi info->id = iothread_get_id(iothread); 291dc3dd0d2SStefan Hajnoczi info->thread_id = iothread->thread_id; 2925fc00480SPavel Hrdina info->poll_max_ns = iothread->poll_max_ns; 2935fc00480SPavel Hrdina info->poll_grow = iothread->poll_grow; 2945fc00480SPavel Hrdina info->poll_shrink = iothread->poll_shrink; 295dc3dd0d2SStefan Hajnoczi 296dc3dd0d2SStefan Hajnoczi elem = g_new0(IOThreadInfoList, 1); 297dc3dd0d2SStefan Hajnoczi elem->value = info; 298dc3dd0d2SStefan Hajnoczi elem->next = NULL; 299dc3dd0d2SStefan Hajnoczi 300dc3dd0d2SStefan Hajnoczi **prev = elem; 301dc3dd0d2SStefan Hajnoczi *prev = &elem->next; 302dc3dd0d2SStefan Hajnoczi return 0; 303dc3dd0d2SStefan Hajnoczi } 304dc3dd0d2SStefan Hajnoczi 305dc3dd0d2SStefan Hajnoczi IOThreadInfoList *qmp_query_iothreads(Error **errp) 306dc3dd0d2SStefan Hajnoczi { 307dc3dd0d2SStefan Hajnoczi IOThreadInfoList *head = NULL; 308dc3dd0d2SStefan Hajnoczi IOThreadInfoList **prev = &head; 309bc2256c4SDaniel P. Berrange Object *container = object_get_objects_root(); 310dc3dd0d2SStefan Hajnoczi 311dc3dd0d2SStefan Hajnoczi object_child_foreach(container, query_one_iothread, &prev); 312dc3dd0d2SStefan Hajnoczi return head; 313dc3dd0d2SStefan Hajnoczi } 314dce8921bSFam Zheng 315dce8921bSFam Zheng void iothread_stop_all(void) 316dce8921bSFam Zheng { 317dce8921bSFam Zheng Object *container = object_get_objects_root(); 318d16341faSPaolo Bonzini BlockDriverState *bs; 319d16341faSPaolo Bonzini BdrvNextIterator it; 320d16341faSPaolo Bonzini 321d16341faSPaolo Bonzini for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { 322d16341faSPaolo Bonzini AioContext *ctx = bdrv_get_aio_context(bs); 323d16341faSPaolo Bonzini if (ctx == qemu_get_aio_context()) { 324d16341faSPaolo Bonzini continue; 325d16341faSPaolo Bonzini } 326d16341faSPaolo Bonzini aio_context_acquire(ctx); 327d16341faSPaolo Bonzini bdrv_set_aio_context(bs, qemu_get_aio_context()); 328d16341faSPaolo Bonzini aio_context_release(ctx); 329d16341faSPaolo Bonzini } 330dce8921bSFam Zheng 331dce8921bSFam Zheng object_child_foreach(container, iothread_stop, NULL); 332dce8921bSFam Zheng } 333*329163cbSWang Yong 334*329163cbSWang Yong static gpointer iothread_g_main_context_init(gpointer opaque) 335*329163cbSWang Yong { 336*329163cbSWang Yong AioContext *ctx; 337*329163cbSWang Yong IOThread *iothread = opaque; 338*329163cbSWang Yong GSource *source; 339*329163cbSWang Yong 340*329163cbSWang Yong iothread->worker_context = g_main_context_new(); 341*329163cbSWang Yong 342*329163cbSWang Yong ctx = iothread_get_aio_context(iothread); 343*329163cbSWang Yong source = aio_get_g_source(ctx); 344*329163cbSWang Yong g_source_attach(source, iothread->worker_context); 345*329163cbSWang Yong g_source_unref(source); 346*329163cbSWang Yong 347*329163cbSWang Yong aio_notify(iothread->ctx); 348*329163cbSWang Yong return NULL; 349*329163cbSWang Yong } 350*329163cbSWang Yong 351*329163cbSWang Yong GMainContext *iothread_get_g_main_context(IOThread *iothread) 352*329163cbSWang Yong { 353*329163cbSWang Yong g_once(&iothread->once, iothread_g_main_context_init, iothread); 354*329163cbSWang Yong 355*329163cbSWang Yong return iothread->worker_context; 356*329163cbSWang Yong } 357