4 * Copyright Red Hat Inc., 2013
7 * Stefan Hajnoczi <stefanha@redhat.com>
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include "qom/object.h"
16 #include "qom/object_interfaces.h"
17 #include "qemu/module.h"
18 #include "block/aio.h"
19 #include "block/block.h"
20 #include "sysemu/iothread.h"
21 #include "qmp-commands.h"
22 #include "qemu/error-report.h"
24 #include "qemu/main-loop.h"
26 typedef ObjectClass IOThreadClass;
28 #define IOTHREAD_GET_CLASS(obj) \
29 OBJECT_GET_CLASS(IOThreadClass, obj, TYPE_IOTHREAD)
30 #define IOTHREAD_CLASS(klass) \
31 OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)
33 static __thread IOThread *my_iothread;
35 AioContext *qemu_get_current_aio_context(void)
37 return my_iothread ? my_iothread->ctx : qemu_get_aio_context();
40 static void *iothread_run(void *opaque)
42 IOThread *iothread = opaque;
44 rcu_register_thread();
46 my_iothread = iothread;
47 qemu_mutex_lock(&iothread->init_done_lock);
48 iothread->thread_id = qemu_get_thread_id();
49 qemu_cond_signal(&iothread->init_done_cond);
50 qemu_mutex_unlock(&iothread->init_done_lock);
52 while (!atomic_read(&iothread->stopping)) {
53 aio_poll(iothread->ctx, true);
56 rcu_unregister_thread();
60 static int iothread_stop(Object *object, void *opaque)
64 iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
65 if (!iothread || !iothread->ctx) {
68 iothread->stopping = true;
69 aio_notify(iothread->ctx);
70 qemu_thread_join(&iothread->thread);
74 static void iothread_instance_finalize(Object *obj)
76 IOThread *iothread = IOTHREAD(obj);
78 iothread_stop(obj, NULL);
79 qemu_cond_destroy(&iothread->init_done_cond);
80 qemu_mutex_destroy(&iothread->init_done_lock);
84 aio_context_unref(iothread->ctx);
87 static void iothread_complete(UserCreatable *obj, Error **errp)
89 Error *local_error = NULL;
90 IOThread *iothread = IOTHREAD(obj);
91 char *name, *thread_name;
93 iothread->stopping = false;
94 iothread->thread_id = -1;
95 iothread->ctx = aio_context_new(&local_error);
97 error_propagate(errp, local_error);
101 aio_context_set_poll_params(iothread->ctx, iothread->poll_max_ns, 0, 0,
104 error_propagate(errp, local_error);
105 aio_context_unref(iothread->ctx);
106 iothread->ctx = NULL;
110 qemu_mutex_init(&iothread->init_done_lock);
111 qemu_cond_init(&iothread->init_done_cond);
113 /* This assumes we are called from a thread with useful CPU affinity for us
116 name = object_get_canonical_path_component(OBJECT(obj));
117 thread_name = g_strdup_printf("IO %s", name);
118 qemu_thread_create(&iothread->thread, thread_name, iothread_run,
119 iothread, QEMU_THREAD_JOINABLE);
123 /* Wait for initialization to complete */
124 qemu_mutex_lock(&iothread->init_done_lock);
125 while (iothread->thread_id == -1) {
126 qemu_cond_wait(&iothread->init_done_cond,
127 &iothread->init_done_lock);
129 qemu_mutex_unlock(&iothread->init_done_lock);
132 static void iothread_get_poll_max_ns(Object *obj, Visitor *v,
133 const char *name, void *opaque, Error **errp)
135 IOThread *iothread = IOTHREAD(obj);
137 visit_type_int64(v, name, &iothread->poll_max_ns, errp);
140 static void iothread_set_poll_max_ns(Object *obj, Visitor *v,
141 const char *name, void *opaque, Error **errp)
143 IOThread *iothread = IOTHREAD(obj);
144 Error *local_err = NULL;
147 visit_type_int64(v, name, &value, &local_err);
153 error_setg(&local_err, "poll_max_ns value must be in range "
154 "[0, %"PRId64"]", INT64_MAX);
158 iothread->poll_max_ns = value;
161 aio_context_set_poll_params(iothread->ctx, value, 0, 0, &local_err);
165 error_propagate(errp, local_err);
168 static void iothread_class_init(ObjectClass *klass, void *class_data)
170 UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
171 ucc->complete = iothread_complete;
173 object_class_property_add(klass, "poll-max-ns", "int",
174 iothread_get_poll_max_ns,
175 iothread_set_poll_max_ns,
176 NULL, NULL, &error_abort);
179 static const TypeInfo iothread_info = {
180 .name = TYPE_IOTHREAD,
181 .parent = TYPE_OBJECT,
182 .class_init = iothread_class_init,
183 .instance_size = sizeof(IOThread),
184 .instance_finalize = iothread_instance_finalize,
185 .interfaces = (InterfaceInfo[]) {
186 {TYPE_USER_CREATABLE},
191 static void iothread_register_types(void)
193 type_register_static(&iothread_info);
196 type_init(iothread_register_types)
198 char *iothread_get_id(IOThread *iothread)
200 return object_get_canonical_path_component(OBJECT(iothread));
203 AioContext *iothread_get_aio_context(IOThread *iothread)
205 return iothread->ctx;
208 static int query_one_iothread(Object *object, void *opaque)
210 IOThreadInfoList ***prev = opaque;
211 IOThreadInfoList *elem;
215 iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
220 info = g_new0(IOThreadInfo, 1);
221 info->id = iothread_get_id(iothread);
222 info->thread_id = iothread->thread_id;
224 elem = g_new0(IOThreadInfoList, 1);
233 IOThreadInfoList *qmp_query_iothreads(Error **errp)
235 IOThreadInfoList *head = NULL;
236 IOThreadInfoList **prev = &head;
237 Object *container = object_get_objects_root();
239 object_child_foreach(container, query_one_iothread, &prev);
243 void iothread_stop_all(void)
245 Object *container = object_get_objects_root();
246 BlockDriverState *bs;
249 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
250 AioContext *ctx = bdrv_get_aio_context(bs);
251 if (ctx == qemu_get_aio_context()) {
254 aio_context_acquire(ctx);
255 bdrv_set_aio_context(bs, qemu_get_aio_context());
256 aio_context_release(ctx);
259 object_child_foreach(container, iothread_stop, NULL);