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12#include "qemu/osdep.h"
13#include "qapi/error.h"
14#include "qemu-common.h"
15#include "qemu/error-report.h"
16#include "sysemu/hostmem.h"
17#include "sysemu/sysemu.h"
18#include "qom/object_interfaces.h"
19
20
21
22
23
24
25#define TYPE_MEMORY_BACKEND_FILE "memory-backend-file"
26
27#define MEMORY_BACKEND_FILE(obj) \
28 OBJECT_CHECK(HostMemoryBackendFile, (obj), TYPE_MEMORY_BACKEND_FILE)
29
30typedef struct HostMemoryBackendFile HostMemoryBackendFile;
31
32struct HostMemoryBackendFile {
33 HostMemoryBackend parent_obj;
34
35 char *mem_path;
36 uint64_t align;
37 bool discard_data;
38 bool is_pmem;
39};
40
41static void
42file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
43{
44 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
45#ifdef CONFIG_POSIX
46 gchar *path;
47#endif
48
49 if (!backend->size) {
50 error_setg(errp, "can't create backend with size 0");
51 return;
52 }
53 if (!fb->mem_path) {
54 error_setg(errp, "mem-path property not set");
55 return;
56 }
57#ifndef CONFIG_POSIX
58 error_setg(errp, "-mem-path not supported on this host");
59#else
60 backend->force_prealloc = mem_prealloc;
61 path = object_get_canonical_path(OBJECT(backend));
62 memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
63 path,
64 backend->size, fb->align,
65 (backend->share ? RAM_SHARED : 0) |
66 (fb->is_pmem ? RAM_PMEM : 0),
67 fb->mem_path, errp);
68 g_free(path);
69#endif
70}
71
72static char *get_mem_path(Object *o, Error **errp)
73{
74 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
75
76 return g_strdup(fb->mem_path);
77}
78
79static void set_mem_path(Object *o, const char *str, Error **errp)
80{
81 HostMemoryBackend *backend = MEMORY_BACKEND(o);
82 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
83
84 if (host_memory_backend_mr_inited(backend)) {
85 error_setg(errp, "cannot change property value");
86 return;
87 }
88 g_free(fb->mem_path);
89 fb->mem_path = g_strdup(str);
90}
91
92static bool file_memory_backend_get_discard_data(Object *o, Error **errp)
93{
94 return MEMORY_BACKEND_FILE(o)->discard_data;
95}
96
97static void file_memory_backend_set_discard_data(Object *o, bool value,
98 Error **errp)
99{
100 MEMORY_BACKEND_FILE(o)->discard_data = value;
101}
102
103static void file_memory_backend_get_align(Object *o, Visitor *v,
104 const char *name, void *opaque,
105 Error **errp)
106{
107 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
108 uint64_t val = fb->align;
109
110 visit_type_size(v, name, &val, errp);
111}
112
113static void file_memory_backend_set_align(Object *o, Visitor *v,
114 const char *name, void *opaque,
115 Error **errp)
116{
117 HostMemoryBackend *backend = MEMORY_BACKEND(o);
118 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
119 Error *local_err = NULL;
120 uint64_t val;
121
122 if (host_memory_backend_mr_inited(backend)) {
123 error_setg(&local_err, "cannot change property value");
124 goto out;
125 }
126
127 visit_type_size(v, name, &val, &local_err);
128 if (local_err) {
129 goto out;
130 }
131 fb->align = val;
132
133 out:
134 error_propagate(errp, local_err);
135}
136
137static bool file_memory_backend_get_pmem(Object *o, Error **errp)
138{
139 return MEMORY_BACKEND_FILE(o)->is_pmem;
140}
141
142static void file_memory_backend_set_pmem(Object *o, bool value, Error **errp)
143{
144 HostMemoryBackend *backend = MEMORY_BACKEND(o);
145 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
146
147 if (host_memory_backend_mr_inited(backend)) {
148 char *path = object_get_canonical_path_component(o);
149
150 error_setg(errp, "cannot change property 'pmem' of %s '%s'",
151 object_get_typename(o),
152 path);
153 g_free(path);
154 return;
155 }
156
157#ifndef CONFIG_LIBPMEM
158 if (value) {
159 Error *local_err = NULL;
160 char *path = object_get_canonical_path_component(o);
161
162 error_setg(&local_err,
163 "Lack of libpmem support while setting the 'pmem=on'"
164 " of %s '%s'. We can't ensure data persistence.",
165 object_get_typename(o),
166 path);
167 g_free(path);
168 error_propagate(errp, local_err);
169 return;
170 }
171#endif
172
173 fb->is_pmem = value;
174}
175
176static void file_backend_unparent(Object *obj)
177{
178 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
179 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj);
180
181 if (host_memory_backend_mr_inited(backend) && fb->discard_data) {
182 void *ptr = memory_region_get_ram_ptr(&backend->mr);
183 uint64_t sz = memory_region_size(&backend->mr);
184
185 qemu_madvise(ptr, sz, QEMU_MADV_REMOVE);
186 }
187}
188
189static void
190file_backend_class_init(ObjectClass *oc, void *data)
191{
192 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
193
194 bc->alloc = file_backend_memory_alloc;
195 oc->unparent = file_backend_unparent;
196
197 object_class_property_add_bool(oc, "discard-data",
198 file_memory_backend_get_discard_data, file_memory_backend_set_discard_data,
199 &error_abort);
200 object_class_property_add_str(oc, "mem-path",
201 get_mem_path, set_mem_path,
202 &error_abort);
203 object_class_property_add(oc, "align", "int",
204 file_memory_backend_get_align,
205 file_memory_backend_set_align,
206 NULL, NULL, &error_abort);
207 object_class_property_add_bool(oc, "pmem",
208 file_memory_backend_get_pmem, file_memory_backend_set_pmem,
209 &error_abort);
210}
211
212static void file_backend_instance_finalize(Object *o)
213{
214 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
215
216 g_free(fb->mem_path);
217}
218
219static const TypeInfo file_backend_info = {
220 .name = TYPE_MEMORY_BACKEND_FILE,
221 .parent = TYPE_MEMORY_BACKEND,
222 .class_init = file_backend_class_init,
223 .instance_finalize = file_backend_instance_finalize,
224 .instance_size = sizeof(HostMemoryBackendFile),
225};
226
227static void register_types(void)
228{
229 type_register_static(&file_backend_info);
230}
231
232type_init(register_types);
233
