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 backend
->aligned
= true;
84 name
= host_memory_backend_get_name(backend
);
85 ram_flags
= backend
->share
? RAM_SHARED
: 0;
86 ram_flags
|= fb
->readonly
? RAM_READONLY_FD
: 0;
87 ram_flags
|= fb
->rom
== ON_OFF_AUTO_ON
? RAM_READONLY
: 0;
88 ram_flags
|= backend
->reserve
? 0 : RAM_NORESERVE
;
89 ram_flags
|= backend
->guest_memfd
? RAM_GUEST_MEMFD
: 0;
90 ram_flags
|= fb
->is_pmem
? RAM_PMEM
: 0;
91 ram_flags
|= RAM_NAMED_FILE
;
92 return memory_region_init_ram_from_file(&backend
->mr
, OBJECT(backend
), name
,
93 backend
->size
, fb
->align
, ram_flags
,
94 fb
->mem_path
, fb
->offset
, errp
);
98 static char *get_mem_path(Object
*o
, Error
**errp
)
100 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
102 return g_strdup(fb
->mem_path
);
105 static void set_mem_path(Object
*o
, const char *str
, Error
**errp
)
107 HostMemoryBackend
*backend
= MEMORY_BACKEND(o
);
108 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
110 if (host_memory_backend_mr_inited(backend
)) {
111 error_setg(errp
, "cannot change property 'mem-path' of %s",
112 object_get_typename(o
));
115 g_free(fb
->mem_path
);
116 fb
->mem_path
= g_strdup(str
);
119 static bool file_memory_backend_get_discard_data(Object
*o
, Error
**errp
)
121 return MEMORY_BACKEND_FILE(o
)->discard_data
;
124 static void file_memory_backend_set_discard_data(Object
*o
, bool value
,
127 MEMORY_BACKEND_FILE(o
)->discard_data
= value
;
130 static void file_memory_backend_get_align(Object
*o
, Visitor
*v
,
131 const char *name
, void *opaque
,
134 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
135 uint64_t val
= fb
->align
;
137 visit_type_size(v
, name
, &val
, errp
);
140 static void file_memory_backend_set_align(Object
*o
, Visitor
*v
,
141 const char *name
, void *opaque
,
144 HostMemoryBackend
*backend
= MEMORY_BACKEND(o
);
145 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
148 if (host_memory_backend_mr_inited(backend
)) {
149 error_setg(errp
, "cannot change property '%s' of %s", name
,
150 object_get_typename(o
));
154 if (!visit_type_size(v
, name
, &val
, errp
)) {
160 static void file_memory_backend_get_offset(Object
*o
, Visitor
*v
,
161 const char *name
, void *opaque
,
164 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
165 uint64_t val
= fb
->offset
;
167 visit_type_size(v
, name
, &val
, errp
);
170 static void file_memory_backend_set_offset(Object
*o
, Visitor
*v
,
171 const char *name
, void *opaque
,
174 HostMemoryBackend
*backend
= MEMORY_BACKEND(o
);
175 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
178 if (host_memory_backend_mr_inited(backend
)) {
179 error_setg(errp
, "cannot change property '%s' of %s", name
,
180 object_get_typename(o
));
184 if (!visit_type_size(v
, name
, &val
, errp
)) {
190 #ifdef CONFIG_LIBPMEM
191 static bool file_memory_backend_get_pmem(Object
*o
, Error
**errp
)
193 return MEMORY_BACKEND_FILE(o
)->is_pmem
;
196 static void file_memory_backend_set_pmem(Object
*o
, bool value
, Error
**errp
)
198 HostMemoryBackend
*backend
= MEMORY_BACKEND(o
);
199 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
201 if (host_memory_backend_mr_inited(backend
)) {
202 error_setg(errp
, "cannot change property 'pmem' of %s.",
203 object_get_typename(o
));
209 #endif /* CONFIG_LIBPMEM */
211 static bool file_memory_backend_get_readonly(Object
*obj
, Error
**errp
)
213 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
218 static void file_memory_backend_set_readonly(Object
*obj
, bool value
,
221 HostMemoryBackend
*backend
= MEMORY_BACKEND(obj
);
222 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
224 if (host_memory_backend_mr_inited(backend
)) {
225 error_setg(errp
, "cannot change property 'readonly' of %s.",
226 object_get_typename(obj
));
230 fb
->readonly
= value
;
233 static void file_memory_backend_get_rom(Object
*obj
, Visitor
*v
,
234 const char *name
, void *opaque
,
237 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
238 OnOffAuto rom
= fb
->rom
;
240 visit_type_OnOffAuto(v
, name
, &rom
, errp
);
243 static void file_memory_backend_set_rom(Object
*obj
, Visitor
*v
,
244 const char *name
, void *opaque
,
247 HostMemoryBackend
*backend
= MEMORY_BACKEND(obj
);
248 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
250 if (host_memory_backend_mr_inited(backend
)) {
251 error_setg(errp
, "cannot change property '%s' of %s.", name
,
252 object_get_typename(obj
));
256 visit_type_OnOffAuto(v
, name
, &fb
->rom
, errp
);
259 static void file_backend_unparent(Object
*obj
)
261 HostMemoryBackend
*backend
= MEMORY_BACKEND(obj
);
262 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(obj
);
264 if (host_memory_backend_mr_inited(backend
) && fb
->discard_data
) {
265 void *ptr
= memory_region_get_ram_ptr(&backend
->mr
);
266 uint64_t sz
= memory_region_size(&backend
->mr
);
268 qemu_madvise(ptr
, sz
, QEMU_MADV_REMOVE
);
273 file_backend_class_init(ObjectClass
*oc
, void *data
)
275 HostMemoryBackendClass
*bc
= MEMORY_BACKEND_CLASS(oc
);
277 bc
->alloc
= file_backend_memory_alloc
;
278 oc
->unparent
= file_backend_unparent
;
280 object_class_property_add_bool(oc
, "discard-data",
281 file_memory_backend_get_discard_data
, file_memory_backend_set_discard_data
);
282 object_class_property_add_str(oc
, "mem-path",
283 get_mem_path
, set_mem_path
);
284 object_class_property_add(oc
, "align", "int",
285 file_memory_backend_get_align
,
286 file_memory_backend_set_align
,
288 object_class_property_add(oc
, "offset", "int",
289 file_memory_backend_get_offset
,
290 file_memory_backend_set_offset
,
292 object_class_property_set_description(oc
, "offset",
293 "Offset into the target file (ex: 1G)");
294 #ifdef CONFIG_LIBPMEM
295 object_class_property_add_bool(oc
, "pmem",
296 file_memory_backend_get_pmem
, file_memory_backend_set_pmem
);
298 object_class_property_add_bool(oc
, "readonly",
299 file_memory_backend_get_readonly
,
300 file_memory_backend_set_readonly
);
301 object_class_property_add(oc
, "rom", "OnOffAuto",
302 file_memory_backend_get_rom
, file_memory_backend_set_rom
, NULL
, NULL
);
303 object_class_property_set_description(oc
, "rom",
304 "Whether to create Read Only Memory (ROM)");
307 static void file_backend_instance_finalize(Object
*o
)
309 HostMemoryBackendFile
*fb
= MEMORY_BACKEND_FILE(o
);
311 g_free(fb
->mem_path
);
314 static const TypeInfo file_backend_info
= {
315 .name
= TYPE_MEMORY_BACKEND_FILE
,
316 .parent
= TYPE_MEMORY_BACKEND
,
317 .class_init
= file_backend_class_init
,
318 .instance_finalize
= file_backend_instance_finalize
,
319 .instance_size
= sizeof(HostMemoryBackendFile
),
322 static void register_types(void)
324 type_register_static(&file_backend_info
);
327 type_init(register_types
);