migration: split migration hooks out of QEMUFileOps
[qemu.git] / backends / hostmem-file.c
1 /*
2 * QEMU Host Memory Backend for hugetlbfs
3 *
4 * Copyright (C) 2013-2014 Red Hat Inc
5 *
6 * Authors:
7 * Paolo Bonzini <pbonzini@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 #include "qemu/osdep.h"
13 #include "qapi/error.h"
14 #include "qemu-common.h"
15 #include "sysemu/hostmem.h"
16 #include "sysemu/sysemu.h"
17 #include "qom/object_interfaces.h"
18
19 /* hostmem-file.c */
20 /**
21 * @TYPE_MEMORY_BACKEND_FILE:
22 * name of backend that uses mmap on a file descriptor
23 */
24 #define TYPE_MEMORY_BACKEND_FILE "memory-backend-file"
25
26 #define MEMORY_BACKEND_FILE(obj) \
27 OBJECT_CHECK(HostMemoryBackendFile, (obj), TYPE_MEMORY_BACKEND_FILE)
28
29 typedef struct HostMemoryBackendFile HostMemoryBackendFile;
30
31 struct HostMemoryBackendFile {
32 HostMemoryBackend parent_obj;
33
34 bool share;
35 char *mem_path;
36 };
37
38 static void
39 file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
40 {
41 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
42
43 if (!backend->size) {
44 error_setg(errp, "can't create backend with size 0");
45 return;
46 }
47 if (!fb->mem_path) {
48 error_setg(errp, "mem-path property not set");
49 return;
50 }
51 #ifndef CONFIG_LINUX
52 error_setg(errp, "-mem-path not supported on this host");
53 #else
54 if (!memory_region_size(&backend->mr)) {
55 gchar *path;
56 backend->force_prealloc = mem_prealloc;
57 path = object_get_canonical_path(OBJECT(backend));
58 memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
59 path,
60 backend->size, fb->share,
61 fb->mem_path, errp);
62 g_free(path);
63 }
64 #endif
65 }
66
67 static void
68 file_backend_class_init(ObjectClass *oc, void *data)
69 {
70 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
71
72 bc->alloc = file_backend_memory_alloc;
73 }
74
75 static char *get_mem_path(Object *o, Error **errp)
76 {
77 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
78
79 return g_strdup(fb->mem_path);
80 }
81
82 static void set_mem_path(Object *o, const char *str, Error **errp)
83 {
84 HostMemoryBackend *backend = MEMORY_BACKEND(o);
85 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
86
87 if (memory_region_size(&backend->mr)) {
88 error_setg(errp, "cannot change property value");
89 return;
90 }
91 g_free(fb->mem_path);
92 fb->mem_path = g_strdup(str);
93 }
94
95 static bool file_memory_backend_get_share(Object *o, Error **errp)
96 {
97 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
98
99 return fb->share;
100 }
101
102 static void file_memory_backend_set_share(Object *o, bool value, Error **errp)
103 {
104 HostMemoryBackend *backend = MEMORY_BACKEND(o);
105 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
106
107 if (memory_region_size(&backend->mr)) {
108 error_setg(errp, "cannot change property value");
109 return;
110 }
111 fb->share = value;
112 }
113
114 static void
115 file_backend_instance_init(Object *o)
116 {
117 object_property_add_bool(o, "share",
118 file_memory_backend_get_share,
119 file_memory_backend_set_share, NULL);
120 object_property_add_str(o, "mem-path", get_mem_path,
121 set_mem_path, NULL);
122 }
123
124 static void file_backend_instance_finalize(Object *o)
125 {
126 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
127
128 g_free(fb->mem_path);
129 }
130
131 static const TypeInfo file_backend_info = {
132 .name = TYPE_MEMORY_BACKEND_FILE,
133 .parent = TYPE_MEMORY_BACKEND,
134 .class_init = file_backend_class_init,
135 .instance_init = file_backend_instance_init,
136 .instance_finalize = file_backend_instance_finalize,
137 .instance_size = sizeof(HostMemoryBackendFile),
138 };
139
140 static void register_types(void)
141 {
142 type_register_static(&file_backend_info);
143 }
144
145 type_init(register_types);