vfio: Create device specific region info helper
[qemu.git] / iothread.c
1 /*
2 * Event loop thread
3 *
4 * Copyright Red Hat Inc., 2013
5 *
6 * Authors:
7 * Stefan Hajnoczi <stefanha@redhat.com>
8 *
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.
11 *
12 */
13
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 "sysemu/iothread.h"
20 #include "qmp-commands.h"
21 #include "qemu/error-report.h"
22 #include "qemu/rcu.h"
23
24 typedef ObjectClass IOThreadClass;
25
26 #define IOTHREAD_GET_CLASS(obj) \
27 OBJECT_GET_CLASS(IOThreadClass, obj, TYPE_IOTHREAD)
28 #define IOTHREAD_CLASS(klass) \
29 OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)
30
31 static void *iothread_run(void *opaque)
32 {
33 IOThread *iothread = opaque;
34 bool blocking;
35
36 rcu_register_thread();
37
38 qemu_mutex_lock(&iothread->init_done_lock);
39 iothread->thread_id = qemu_get_thread_id();
40 qemu_cond_signal(&iothread->init_done_cond);
41 qemu_mutex_unlock(&iothread->init_done_lock);
42
43 while (!iothread->stopping) {
44 aio_context_acquire(iothread->ctx);
45 blocking = true;
46 while (!iothread->stopping && aio_poll(iothread->ctx, blocking)) {
47 /* Progress was made, keep going */
48 blocking = false;
49 }
50 aio_context_release(iothread->ctx);
51 }
52
53 rcu_unregister_thread();
54 return NULL;
55 }
56
57 static void iothread_instance_finalize(Object *obj)
58 {
59 IOThread *iothread = IOTHREAD(obj);
60
61 if (!iothread->ctx) {
62 return;
63 }
64 iothread->stopping = true;
65 aio_notify(iothread->ctx);
66 qemu_thread_join(&iothread->thread);
67 qemu_cond_destroy(&iothread->init_done_cond);
68 qemu_mutex_destroy(&iothread->init_done_lock);
69 aio_context_unref(iothread->ctx);
70 }
71
72 static void iothread_complete(UserCreatable *obj, Error **errp)
73 {
74 Error *local_error = NULL;
75 IOThread *iothread = IOTHREAD(obj);
76 char *name, *thread_name;
77
78 iothread->stopping = false;
79 iothread->thread_id = -1;
80 iothread->ctx = aio_context_new(&local_error);
81 if (!iothread->ctx) {
82 error_propagate(errp, local_error);
83 return;
84 }
85
86 qemu_mutex_init(&iothread->init_done_lock);
87 qemu_cond_init(&iothread->init_done_cond);
88
89 /* This assumes we are called from a thread with useful CPU affinity for us
90 * to inherit.
91 */
92 name = object_get_canonical_path_component(OBJECT(obj));
93 thread_name = g_strdup_printf("IO %s", name);
94 qemu_thread_create(&iothread->thread, thread_name, iothread_run,
95 iothread, QEMU_THREAD_JOINABLE);
96 g_free(thread_name);
97 g_free(name);
98
99 /* Wait for initialization to complete */
100 qemu_mutex_lock(&iothread->init_done_lock);
101 while (iothread->thread_id == -1) {
102 qemu_cond_wait(&iothread->init_done_cond,
103 &iothread->init_done_lock);
104 }
105 qemu_mutex_unlock(&iothread->init_done_lock);
106 }
107
108 static void iothread_class_init(ObjectClass *klass, void *class_data)
109 {
110 UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
111 ucc->complete = iothread_complete;
112 }
113
114 static const TypeInfo iothread_info = {
115 .name = TYPE_IOTHREAD,
116 .parent = TYPE_OBJECT,
117 .class_init = iothread_class_init,
118 .instance_size = sizeof(IOThread),
119 .instance_finalize = iothread_instance_finalize,
120 .interfaces = (InterfaceInfo[]) {
121 {TYPE_USER_CREATABLE},
122 {}
123 },
124 };
125
126 static void iothread_register_types(void)
127 {
128 type_register_static(&iothread_info);
129 }
130
131 type_init(iothread_register_types)
132
133 char *iothread_get_id(IOThread *iothread)
134 {
135 return object_get_canonical_path_component(OBJECT(iothread));
136 }
137
138 AioContext *iothread_get_aio_context(IOThread *iothread)
139 {
140 return iothread->ctx;
141 }
142
143 static int query_one_iothread(Object *object, void *opaque)
144 {
145 IOThreadInfoList ***prev = opaque;
146 IOThreadInfoList *elem;
147 IOThreadInfo *info;
148 IOThread *iothread;
149
150 iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
151 if (!iothread) {
152 return 0;
153 }
154
155 info = g_new0(IOThreadInfo, 1);
156 info->id = iothread_get_id(iothread);
157 info->thread_id = iothread->thread_id;
158
159 elem = g_new0(IOThreadInfoList, 1);
160 elem->value = info;
161 elem->next = NULL;
162
163 **prev = elem;
164 *prev = &elem->next;
165 return 0;
166 }
167
168 IOThreadInfoList *qmp_query_iothreads(Error **errp)
169 {
170 IOThreadInfoList *head = NULL;
171 IOThreadInfoList **prev = &head;
172 Object *container = object_get_objects_root();
173
174 object_child_foreach(container, query_one_iothread, &prev);
175 return head;
176 }