Merge tag 'pull-la-20220704' of https://gitlab.com/rth7680/qemu into staging
[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
13 #include "qemu/osdep.h"
14 #include "qapi/error.h"
15 #include "qemu/error-report.h"
16 #include "qemu/module.h"
17 #include "qemu/madvise.h"
18 #include "sysemu/hostmem.h"
19 #include "qom/object_interfaces.h"
20 #include "qom/object.h"
21
22 OBJECT_DECLARE_SIMPLE_TYPE(HostMemoryBackendFile, MEMORY_BACKEND_FILE)
23
24
25 struct HostMemoryBackendFile {
26 HostMemoryBackend parent_obj;
27
28 char *mem_path;
29 uint64_t align;
30 bool discard_data;
31 bool is_pmem;
32 bool readonly;
33 };
34
35 static void
36 file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
37 {
38 #ifndef CONFIG_POSIX
39 error_setg(errp, "backend '%s' not supported on this host",
40 object_get_typename(OBJECT(backend)));
41 #else
42 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
43 uint32_t ram_flags;
44 gchar *name;
45
46 if (!backend->size) {
47 error_setg(errp, "can't create backend with size 0");
48 return;
49 }
50 if (!fb->mem_path) {
51 error_setg(errp, "mem-path property not set");
52 return;
53 }
54
55 name = host_memory_backend_get_name(backend);
56 ram_flags = backend->share ? RAM_SHARED : 0;
57 ram_flags |= backend->reserve ? 0 : RAM_NORESERVE;
58 ram_flags |= fb->is_pmem ? RAM_PMEM : 0;
59 memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name,
60 backend->size, fb->align, ram_flags,
61 fb->mem_path, fb->readonly, errp);
62 g_free(name);
63 #endif
64 }
65
66 static char *get_mem_path(Object *o, Error **errp)
67 {
68 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
69
70 return g_strdup(fb->mem_path);
71 }
72
73 static void set_mem_path(Object *o, const char *str, Error **errp)
74 {
75 HostMemoryBackend *backend = MEMORY_BACKEND(o);
76 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
77
78 if (host_memory_backend_mr_inited(backend)) {
79 error_setg(errp, "cannot change property 'mem-path' of %s",
80 object_get_typename(o));
81 return;
82 }
83 g_free(fb->mem_path);
84 fb->mem_path = g_strdup(str);
85 }
86
87 static bool file_memory_backend_get_discard_data(Object *o, Error **errp)
88 {
89 return MEMORY_BACKEND_FILE(o)->discard_data;
90 }
91
92 static void file_memory_backend_set_discard_data(Object *o, bool value,
93 Error **errp)
94 {
95 MEMORY_BACKEND_FILE(o)->discard_data = value;
96 }
97
98 static void file_memory_backend_get_align(Object *o, Visitor *v,
99 const char *name, void *opaque,
100 Error **errp)
101 {
102 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
103 uint64_t val = fb->align;
104
105 visit_type_size(v, name, &val, errp);
106 }
107
108 static void file_memory_backend_set_align(Object *o, Visitor *v,
109 const char *name, void *opaque,
110 Error **errp)
111 {
112 HostMemoryBackend *backend = MEMORY_BACKEND(o);
113 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
114 uint64_t val;
115
116 if (host_memory_backend_mr_inited(backend)) {
117 error_setg(errp, "cannot change property '%s' of %s", name,
118 object_get_typename(o));
119 return;
120 }
121
122 if (!visit_type_size(v, name, &val, errp)) {
123 return;
124 }
125 fb->align = val;
126 }
127
128 #ifdef CONFIG_LIBPMEM
129 static bool file_memory_backend_get_pmem(Object *o, Error **errp)
130 {
131 return MEMORY_BACKEND_FILE(o)->is_pmem;
132 }
133
134 static void file_memory_backend_set_pmem(Object *o, bool value, Error **errp)
135 {
136 HostMemoryBackend *backend = MEMORY_BACKEND(o);
137 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
138
139 if (host_memory_backend_mr_inited(backend)) {
140 error_setg(errp, "cannot change property 'pmem' of %s.",
141 object_get_typename(o));
142 return;
143 }
144
145 fb->is_pmem = value;
146 }
147 #endif /* CONFIG_LIBPMEM */
148
149 static bool file_memory_backend_get_readonly(Object *obj, Error **errp)
150 {
151 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj);
152
153 return fb->readonly;
154 }
155
156 static void file_memory_backend_set_readonly(Object *obj, bool value,
157 Error **errp)
158 {
159 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
160 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj);
161
162 if (host_memory_backend_mr_inited(backend)) {
163 error_setg(errp, "cannot change property 'readonly' of %s.",
164 object_get_typename(obj));
165 return;
166 }
167
168 fb->readonly = value;
169 }
170
171 static void file_backend_unparent(Object *obj)
172 {
173 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
174 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj);
175
176 if (host_memory_backend_mr_inited(backend) && fb->discard_data) {
177 void *ptr = memory_region_get_ram_ptr(&backend->mr);
178 uint64_t sz = memory_region_size(&backend->mr);
179
180 qemu_madvise(ptr, sz, QEMU_MADV_REMOVE);
181 }
182 }
183
184 static void
185 file_backend_class_init(ObjectClass *oc, void *data)
186 {
187 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
188
189 bc->alloc = file_backend_memory_alloc;
190 oc->unparent = file_backend_unparent;
191
192 object_class_property_add_bool(oc, "discard-data",
193 file_memory_backend_get_discard_data, file_memory_backend_set_discard_data);
194 object_class_property_add_str(oc, "mem-path",
195 get_mem_path, set_mem_path);
196 object_class_property_add(oc, "align", "int",
197 file_memory_backend_get_align,
198 file_memory_backend_set_align,
199 NULL, NULL);
200 #ifdef CONFIG_LIBPMEM
201 object_class_property_add_bool(oc, "pmem",
202 file_memory_backend_get_pmem, file_memory_backend_set_pmem);
203 #endif
204 object_class_property_add_bool(oc, "readonly",
205 file_memory_backend_get_readonly,
206 file_memory_backend_set_readonly);
207 }
208
209 static void file_backend_instance_finalize(Object *o)
210 {
211 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
212
213 g_free(fb->mem_path);
214 }
215
216 static const TypeInfo file_backend_info = {
217 .name = TYPE_MEMORY_BACKEND_FILE,
218 .parent = TYPE_MEMORY_BACKEND,
219 .class_init = file_backend_class_init,
220 .instance_finalize = file_backend_instance_finalize,
221 .instance_size = sizeof(HostMemoryBackendFile),
222 };
223
224 static void register_types(void)
225 {
226 type_register_static(&file_backend_info);
227 }
228
229 type_init(register_types);