xref: /openbmc/qemu/event-loop-base.c (revision d695918f)
1 /*
2  * QEMU event-loop base
3  *
4  * Copyright (C) 2022 Red Hat Inc
5  *
6  * Authors:
7  *  Stefan Hajnoczi <stefanha@redhat.com>
8  *  Nicolas Saenz Julienne <nsaenzju@redhat.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qom/object_interfaces.h"
16 #include "qapi/error.h"
17 #include "block/thread-pool.h"
18 #include "sysemu/event-loop-base.h"
19 
20 typedef struct {
21     const char *name;
22     ptrdiff_t offset; /* field's byte offset in EventLoopBase struct */
23 } EventLoopBaseParamInfo;
24 
25 static void event_loop_base_instance_init(Object *obj)
26 {
27     EventLoopBase *base = EVENT_LOOP_BASE(obj);
28 
29     base->thread_pool_max = THREAD_POOL_MAX_THREADS_DEFAULT;
30 }
31 
32 static EventLoopBaseParamInfo aio_max_batch_info = {
33     "aio-max-batch", offsetof(EventLoopBase, aio_max_batch),
34 };
35 static EventLoopBaseParamInfo thread_pool_min_info = {
36     "thread-pool-min", offsetof(EventLoopBase, thread_pool_min),
37 };
38 static EventLoopBaseParamInfo thread_pool_max_info = {
39     "thread-pool-max", offsetof(EventLoopBase, thread_pool_max),
40 };
41 
42 static void event_loop_base_get_param(Object *obj, Visitor *v,
43         const char *name, void *opaque, Error **errp)
44 {
45     EventLoopBase *event_loop_base = EVENT_LOOP_BASE(obj);
46     EventLoopBaseParamInfo *info = opaque;
47     int64_t *field = (void *)event_loop_base + info->offset;
48 
49     visit_type_int64(v, name, field, errp);
50 }
51 
52 static void event_loop_base_set_param(Object *obj, Visitor *v,
53         const char *name, void *opaque, Error **errp)
54 {
55     EventLoopBaseClass *bc = EVENT_LOOP_BASE_GET_CLASS(obj);
56     EventLoopBase *base = EVENT_LOOP_BASE(obj);
57     EventLoopBaseParamInfo *info = opaque;
58     int64_t *field = (void *)base + info->offset;
59     int64_t value;
60 
61     if (!visit_type_int64(v, name, &value, errp)) {
62         return;
63     }
64 
65     if (value < 0) {
66         error_setg(errp, "%s value must be in range [0, %" PRId64 "]",
67                    info->name, INT64_MAX);
68         return;
69     }
70 
71     *field = value;
72 
73     if (bc->update_params) {
74         bc->update_params(base, errp);
75     }
76 
77     return;
78 }
79 
80 static void event_loop_base_complete(UserCreatable *uc, Error **errp)
81 {
82     EventLoopBaseClass *bc = EVENT_LOOP_BASE_GET_CLASS(uc);
83     EventLoopBase *base = EVENT_LOOP_BASE(uc);
84 
85     if (bc->init) {
86         bc->init(base, errp);
87     }
88 }
89 
90 static bool event_loop_base_can_be_deleted(UserCreatable *uc)
91 {
92     EventLoopBaseClass *bc = EVENT_LOOP_BASE_GET_CLASS(uc);
93     EventLoopBase *backend = EVENT_LOOP_BASE(uc);
94 
95     if (bc->can_be_deleted) {
96         return bc->can_be_deleted(backend);
97     }
98 
99     return true;
100 }
101 
102 static void event_loop_base_class_init(ObjectClass *klass, void *class_data)
103 {
104     UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
105     ucc->complete = event_loop_base_complete;
106     ucc->can_be_deleted = event_loop_base_can_be_deleted;
107 
108     object_class_property_add(klass, "aio-max-batch", "int",
109                               event_loop_base_get_param,
110                               event_loop_base_set_param,
111                               NULL, &aio_max_batch_info);
112     object_class_property_add(klass, "thread-pool-min", "int",
113                               event_loop_base_get_param,
114                               event_loop_base_set_param,
115                               NULL, &thread_pool_min_info);
116     object_class_property_add(klass, "thread-pool-max", "int",
117                               event_loop_base_get_param,
118                               event_loop_base_set_param,
119                               NULL, &thread_pool_max_info);
120 }
121 
122 static const TypeInfo event_loop_base_info = {
123     .name = TYPE_EVENT_LOOP_BASE,
124     .parent = TYPE_OBJECT,
125     .instance_size = sizeof(EventLoopBase),
126     .instance_init = event_loop_base_instance_init,
127     .class_size = sizeof(EventLoopBaseClass),
128     .class_init = event_loop_base_class_init,
129     .abstract = true,
130     .interfaces = (InterfaceInfo[]) {
131         { TYPE_USER_CREATABLE },
132         { }
133     }
134 };
135 
136 static void register_types(void)
137 {
138     type_register_static(&event_loop_base_info);
139 }
140 type_init(register_types);
141