2 * QEMU Host Memory Backend for hugetlbfs
4 * Copyright (C) 2013-2014 Red Hat Inc
7 * Paolo Bonzini <pbonzini@redhat.com>
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.
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 #include "qapi/visitor.h"
22 #include "qapi/qapi-visit-common.h"
24 OBJECT_DECLARE_SIMPLE_TYPE(HostMemoryBackendFile
, MEMORY_BACKEND_FILE
)
27 struct HostMemoryBackendFile
{
28 HostMemoryBackend parent_obj
;
40 file_backend_memory_alloc(HostMemoryBackend
*backend
, Error
**errp
)
43 error_setg(errp
, "backend '%s' not supported on this host",
44 object_get_typename(OBJECT(backend
)));
47 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(backend
);
48 g_autofree gchar
*name
= NULL
;
52 error_setg(errp
, "can't create backend with size 0");
56 error_setg(errp
, "mem-path property not set");
61 case ON_OFF_AUTO_AUTO
:
62 /* Traditionally, opening the file readonly always resulted in ROM. */
63 fb
->rom
= fb
->readonly
? ON_OFF_AUTO_ON
: ON_OFF_AUTO_OFF
;
67 error_setg(errp
, "property 'rom' = 'on' is not supported with"
68 " 'readonly' = 'off'");
73 if (fb
->readonly
&& backend
->share
) {
74 error_setg(errp
, "property 'rom' = 'off' is incompatible with"
75 " 'readonly' = 'on' and 'share' = 'on'");
80 g_assert_not_reached();
83 name
= host_memory_backend_get_name(backend
);
84 ram_flags
= backend
->share
? RAM_SHARED
: 0;
85 ram_flags
|= fb
->readonly
? RAM_READONLY_FD
: 0;
86 ram_flags
|= fb
->rom
== ON_OFF_AUTO_ON
? RAM_READONLY
: 0;
87 ram_flags
|= backend
->reserve
? 0 : RAM_NORESERVE
;
88 ram_flags
|= backend
->guest_memfd
? RAM_GUEST_MEMFD
: 0;
89 ram_flags
|= fb
->is_pmem
? RAM_PMEM
: 0;
90 ram_flags
|= RAM_NAMED_FILE
;
91 return memory_region_init_ram_from_file(&backend
->mr
, OBJECT(backend
), name
,
92 backend
->size
, fb
->align
, ram_flags
,
93 fb
->mem_path
, fb
->offset
, errp
);
97 static char *get_mem_path(Object
*o
, Error
**errp
)
99 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
101 return g_strdup(fb
->mem_path
);
104 static void set_mem_path(Object
*o
, const char *str
, Error
**errp
)
106 HostMemoryBackend
*backend
= MEMORY_BACKEND(o
);
107 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
109 if (host_memory_backend_mr_inited(backend
)) {
110 error_setg(errp
, "cannot change property 'mem-path' of %s",
111 object_get_typename(o
));
114 g_free(fb
->mem_path
);
115 fb
->mem_path
= g_strdup(str
);
118 static bool file_memory_backend_get_discard_data(Object
*o
, Error
**errp
)
120 return MEMORY_BACKEND_FILE(o
)->discard_data
;
123 static void file_memory_backend_set_discard_data(Object
*o
, bool value
,
126 MEMORY_BACKEND_FILE(o
)->discard_data
= value
;
129 static void file_memory_backend_get_align(Object
*o
, Visitor
*v
,
130 const char *name
, void *opaque
,
133 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
134 uint64_t val
= fb
->align
;
136 visit_type_size(v
, name
, &val
, errp
);
139 static void file_memory_backend_set_align(Object
*o
, Visitor
*v
,
140 const char *name
, void *opaque
,
143 HostMemoryBackend
*backend
= MEMORY_BACKEND(o
);
144 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
147 if (host_memory_backend_mr_inited(backend
)) {
148 error_setg(errp
, "cannot change property '%s' of %s", name
,
149 object_get_typename(o
));
153 if (!visit_type_size(v
, name
, &val
, errp
)) {
159 static void file_memory_backend_get_offset(Object
*o
, Visitor
*v
,
160 const char *name
, void *opaque
,
163 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
164 uint64_t val
= fb
->offset
;
166 visit_type_size(v
, name
, &val
, errp
);
169 static void file_memory_backend_set_offset(Object
*o
, Visitor
*v
,
170 const char *name
, void *opaque
,
173 HostMemoryBackend
*backend
= MEMORY_BACKEND(o
);
174 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
177 if (host_memory_backend_mr_inited(backend
)) {
178 error_setg(errp
, "cannot change property '%s' of %s", name
,
179 object_get_typename(o
));
183 if (!visit_type_size(v
, name
, &val
, errp
)) {
189 #ifdef CONFIG_LIBPMEM
190 static bool file_memory_backend_get_pmem(Object
*o
, Error
**errp
)
192 return MEMORY_BACKEND_FILE(o
)->is_pmem
;
195 static void file_memory_backend_set_pmem(Object
*o
, bool value
, Error
**errp
)
197 HostMemoryBackend
*backend
= MEMORY_BACKEND(o
);
198 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
200 if (host_memory_backend_mr_inited(backend
)) {
201 error_setg(errp
, "cannot change property 'pmem' of %s.",
202 object_get_typename(o
));
208 #endif /* CONFIG_LIBPMEM */
210 static bool file_memory_backend_get_readonly(Object
*obj
, Error
**errp
)
212 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
217 static void file_memory_backend_set_readonly(Object
*obj
, bool value
,
220 HostMemoryBackend
*backend
= MEMORY_BACKEND(obj
);
221 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
223 if (host_memory_backend_mr_inited(backend
)) {
224 error_setg(errp
, "cannot change property 'readonly' of %s.",
225 object_get_typename(obj
));
229 fb
->readonly
= value
;
232 static void file_memory_backend_get_rom(Object
*obj
, Visitor
*v
,
233 const char *name
, void *opaque
,
236 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
237 OnOffAuto rom
= fb
->rom
;
239 visit_type_OnOffAuto(v
, name
, &rom
, errp
);
242 static void file_memory_backend_set_rom(Object
*obj
, Visitor
*v
,
243 const char *name
, void *opaque
,
246 HostMemoryBackend
*backend
= MEMORY_BACKEND(obj
);
247 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
249 if (host_memory_backend_mr_inited(backend
)) {
250 error_setg(errp
, "cannot change property '%s' of %s.", name
,
251 object_get_typename(obj
));
255 visit_type_OnOffAuto(v
, name
, &fb
->rom
, errp
);
258 static void file_backend_unparent(Object
*obj
)
260 HostMemoryBackend
*backend
= MEMORY_BACKEND(obj
);
261 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
263 if (host_memory_backend_mr_inited(backend
) && fb
->discard_data
) {
264 void *ptr
= memory_region_get_ram_ptr(&backend
->mr
);
265 uint64_t sz
= memory_region_size(&backend
->mr
);
267 qemu_madvise(ptr
, sz
, QEMU_MADV_REMOVE
);
272 file_backend_class_init(ObjectClass
*oc
, void *data
)
274 HostMemoryBackendClass
*bc
= MEMORY_BACKEND_CLASS(oc
);
276 bc
->alloc
= file_backend_memory_alloc
;
277 oc
->unparent
= file_backend_unparent
;
279 object_class_property_add_bool(oc
, "discard-data",
280 file_memory_backend_get_discard_data
, file_memory_backend_set_discard_data
);
281 object_class_property_add_str(oc
, "mem-path",
282 get_mem_path
, set_mem_path
);
283 object_class_property_add(oc
, "align", "int",
284 file_memory_backend_get_align
,
285 file_memory_backend_set_align
,
287 object_class_property_add(oc
, "offset", "int",
288 file_memory_backend_get_offset
,
289 file_memory_backend_set_offset
,
291 object_class_property_set_description(oc
, "offset",
292 "Offset into the target file (ex: 1G)");
293 #ifdef CONFIG_LIBPMEM
294 object_class_property_add_bool(oc
, "pmem",
295 file_memory_backend_get_pmem
, file_memory_backend_set_pmem
);
297 object_class_property_add_bool(oc
, "readonly",
298 file_memory_backend_get_readonly
,
299 file_memory_backend_set_readonly
);
300 object_class_property_add(oc
, "rom", "OnOffAuto",
301 file_memory_backend_get_rom
, file_memory_backend_set_rom
, NULL
, NULL
);
302 object_class_property_set_description(oc
, "rom",
303 "Whether to create Read Only Memory (ROM)");
306 static void file_backend_instance_finalize(Object
*o
)
308 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
310 g_free(fb
->mem_path
);
313 static const TypeInfo file_backend_info
= {
314 .name
= TYPE_MEMORY_BACKEND_FILE
,
315 .parent
= TYPE_MEMORY_BACKEND
,
316 .class_init
= file_backend_class_init
,
317 .instance_finalize
= file_backend_instance_finalize
,
318 .instance_size
= sizeof(HostMemoryBackendFile
),
321 static void register_types(void)
323 type_register_static(&file_backend_info
);
326 type_init(register_types
);