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 "sysemu/hostmem.h"
18 #include "sysemu/sysemu.h"
19 #include "qom/object_interfaces.h"
20 #include "qom/object.h"
22 typedef struct HostMemoryBackendFile HostMemoryBackendFile;
23 DECLARE_INSTANCE_CHECKER(HostMemoryBackendFile, MEMORY_BACKEND_FILE,
24 TYPE_MEMORY_BACKEND_FILE)
27 struct HostMemoryBackendFile {
28 HostMemoryBackend parent_obj;
37 file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
40 error_setg(errp, "backend '%s' not supported on this host",
41 object_get_typename(OBJECT(backend)));
43 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
47 error_setg(errp, "can't create backend with size 0");
51 error_setg(errp, "mem-path property not set");
55 name = host_memory_backend_get_name(backend);
56 memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
58 backend->size, fb->align,
59 (backend->share ? RAM_SHARED : 0) |
60 (fb->is_pmem ? RAM_PMEM : 0),
66 static char *get_mem_path(Object *o, Error **errp)
68 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
70 return g_strdup(fb->mem_path);
73 static void set_mem_path(Object *o, const char *str, Error **errp)
75 HostMemoryBackend *backend = MEMORY_BACKEND(o);
76 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
78 if (host_memory_backend_mr_inited(backend)) {
79 error_setg(errp, "cannot change property 'mem-path' of %s",
80 object_get_typename(o));
84 fb->mem_path = g_strdup(str);
87 static bool file_memory_backend_get_discard_data(Object *o, Error **errp)
89 return MEMORY_BACKEND_FILE(o)->discard_data;
92 static void file_memory_backend_set_discard_data(Object *o, bool value,
95 MEMORY_BACKEND_FILE(o)->discard_data = value;
98 static void file_memory_backend_get_align(Object *o, Visitor *v,
99 const char *name, void *opaque,
102 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
103 uint64_t val = fb->align;
105 visit_type_size(v, name, &val, errp);
108 static void file_memory_backend_set_align(Object *o, Visitor *v,
109 const char *name, void *opaque,
112 HostMemoryBackend *backend = MEMORY_BACKEND(o);
113 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
116 if (host_memory_backend_mr_inited(backend)) {
117 error_setg(errp, "cannot change property '%s' of %s", name,
118 object_get_typename(o));
122 if (!visit_type_size(v, name, &val, errp)) {
128 static bool file_memory_backend_get_pmem(Object *o, Error **errp)
130 return MEMORY_BACKEND_FILE(o)->is_pmem;
133 static void file_memory_backend_set_pmem(Object *o, bool value, Error **errp)
135 HostMemoryBackend *backend = MEMORY_BACKEND(o);
136 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
138 if (host_memory_backend_mr_inited(backend)) {
139 error_setg(errp, "cannot change property 'pmem' of %s.",
140 object_get_typename(o));
144 #ifndef CONFIG_LIBPMEM
146 error_setg(errp, "Lack of libpmem support while setting the 'pmem=on'"
147 " of %s. We can't ensure data persistence.",
148 object_get_typename(o));
156 static void file_backend_unparent(Object *obj)
158 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
159 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj);
161 if (host_memory_backend_mr_inited(backend) && fb->discard_data) {
162 void *ptr = memory_region_get_ram_ptr(&backend->mr);
163 uint64_t sz = memory_region_size(&backend->mr);
165 qemu_madvise(ptr, sz, QEMU_MADV_REMOVE);
170 file_backend_class_init(ObjectClass *oc, void *data)
172 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
174 bc->alloc = file_backend_memory_alloc;
175 oc->unparent = file_backend_unparent;
177 object_class_property_add_bool(oc, "discard-data",
178 file_memory_backend_get_discard_data, file_memory_backend_set_discard_data);
179 object_class_property_add_str(oc, "mem-path",
180 get_mem_path, set_mem_path);
181 object_class_property_add(oc, "align", "int",
182 file_memory_backend_get_align,
183 file_memory_backend_set_align,
185 object_class_property_add_bool(oc, "pmem",
186 file_memory_backend_get_pmem, file_memory_backend_set_pmem);
189 static void file_backend_instance_finalize(Object *o)
191 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
193 g_free(fb->mem_path);
196 static const TypeInfo file_backend_info = {
197 .name = TYPE_MEMORY_BACKEND_FILE,
198 .parent = TYPE_MEMORY_BACKEND,
199 .class_init = file_backend_class_init,
200 .instance_finalize = file_backend_instance_finalize,
201 .instance_size = sizeof(HostMemoryBackendFile),
204 static void register_types(void)
206 type_register_static(&file_backend_info);
209 type_init(register_types);