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 uint64_t offset; 31 bool discard_data; 32 bool is_pmem; 33 bool readonly; 34 }; 35 36 static void 37 file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) 38 { 39 #ifndef CONFIG_POSIX 40 error_setg(errp, "backend '%s' not supported on this host", 41 object_get_typename(OBJECT(backend))); 42 #else 43 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend); 44 uint32_t ram_flags; 45 gchar *name; 46 47 if (!backend->size) { 48 error_setg(errp, "can't create backend with size 0"); 49 return; 50 } 51 if (!fb->mem_path) { 52 error_setg(errp, "mem-path property not set"); 53 return; 54 } 55 56 name = host_memory_backend_get_name(backend); 57 ram_flags = backend->share ? RAM_SHARED : 0; 58 ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; 59 ram_flags |= fb->is_pmem ? RAM_PMEM : 0; 60 memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name, 61 backend->size, fb->align, ram_flags, 62 fb->mem_path, fb->offset, fb->readonly, 63 errp); 64 g_free(name); 65 #endif 66 } 67 68 static char *get_mem_path(Object *o, Error **errp) 69 { 70 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); 71 72 return g_strdup(fb->mem_path); 73 } 74 75 static void set_mem_path(Object *o, const char *str, Error **errp) 76 { 77 HostMemoryBackend *backend = MEMORY_BACKEND(o); 78 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); 79 80 if (host_memory_backend_mr_inited(backend)) { 81 error_setg(errp, "cannot change property 'mem-path' of %s", 82 object_get_typename(o)); 83 return; 84 } 85 g_free(fb->mem_path); 86 fb->mem_path = g_strdup(str); 87 } 88 89 static bool file_memory_backend_get_discard_data(Object *o, Error **errp) 90 { 91 return MEMORY_BACKEND_FILE(o)->discard_data; 92 } 93 94 static void file_memory_backend_set_discard_data(Object *o, bool value, 95 Error **errp) 96 { 97 MEMORY_BACKEND_FILE(o)->discard_data = value; 98 } 99 100 static void file_memory_backend_get_align(Object *o, Visitor *v, 101 const char *name, void *opaque, 102 Error **errp) 103 { 104 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); 105 uint64_t val = fb->align; 106 107 visit_type_size(v, name, &val, errp); 108 } 109 110 static void file_memory_backend_set_align(Object *o, Visitor *v, 111 const char *name, void *opaque, 112 Error **errp) 113 { 114 HostMemoryBackend *backend = MEMORY_BACKEND(o); 115 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); 116 uint64_t val; 117 118 if (host_memory_backend_mr_inited(backend)) { 119 error_setg(errp, "cannot change property '%s' of %s", name, 120 object_get_typename(o)); 121 return; 122 } 123 124 if (!visit_type_size(v, name, &val, errp)) { 125 return; 126 } 127 fb->align = val; 128 } 129 130 static void file_memory_backend_get_offset(Object *o, Visitor *v, 131 const char *name, void *opaque, 132 Error **errp) 133 { 134 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); 135 uint64_t val = fb->offset; 136 137 visit_type_size(v, name, &val, errp); 138 } 139 140 static void file_memory_backend_set_offset(Object *o, Visitor *v, 141 const char *name, void *opaque, 142 Error **errp) 143 { 144 HostMemoryBackend *backend = MEMORY_BACKEND(o); 145 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); 146 uint64_t val; 147 148 if (host_memory_backend_mr_inited(backend)) { 149 error_setg(errp, "cannot change property '%s' of %s", name, 150 object_get_typename(o)); 151 return; 152 } 153 154 if (!visit_type_size(v, name, &val, errp)) { 155 return; 156 } 157 fb->offset = val; 158 } 159 160 #ifdef CONFIG_LIBPMEM 161 static bool file_memory_backend_get_pmem(Object *o, Error **errp) 162 { 163 return MEMORY_BACKEND_FILE(o)->is_pmem; 164 } 165 166 static void file_memory_backend_set_pmem(Object *o, bool value, Error **errp) 167 { 168 HostMemoryBackend *backend = MEMORY_BACKEND(o); 169 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); 170 171 if (host_memory_backend_mr_inited(backend)) { 172 error_setg(errp, "cannot change property 'pmem' of %s.", 173 object_get_typename(o)); 174 return; 175 } 176 177 fb->is_pmem = value; 178 } 179 #endif /* CONFIG_LIBPMEM */ 180 181 static bool file_memory_backend_get_readonly(Object *obj, Error **errp) 182 { 183 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj); 184 185 return fb->readonly; 186 } 187 188 static void file_memory_backend_set_readonly(Object *obj, bool value, 189 Error **errp) 190 { 191 HostMemoryBackend *backend = MEMORY_BACKEND(obj); 192 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj); 193 194 if (host_memory_backend_mr_inited(backend)) { 195 error_setg(errp, "cannot change property 'readonly' of %s.", 196 object_get_typename(obj)); 197 return; 198 } 199 200 fb->readonly = value; 201 } 202 203 static void file_backend_unparent(Object *obj) 204 { 205 HostMemoryBackend *backend = MEMORY_BACKEND(obj); 206 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj); 207 208 if (host_memory_backend_mr_inited(backend) && fb->discard_data) { 209 void *ptr = memory_region_get_ram_ptr(&backend->mr); 210 uint64_t sz = memory_region_size(&backend->mr); 211 212 qemu_madvise(ptr, sz, QEMU_MADV_REMOVE); 213 } 214 } 215 216 static void 217 file_backend_class_init(ObjectClass *oc, void *data) 218 { 219 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc); 220 221 bc->alloc = file_backend_memory_alloc; 222 oc->unparent = file_backend_unparent; 223 224 object_class_property_add_bool(oc, "discard-data", 225 file_memory_backend_get_discard_data, file_memory_backend_set_discard_data); 226 object_class_property_add_str(oc, "mem-path", 227 get_mem_path, set_mem_path); 228 object_class_property_add(oc, "align", "int", 229 file_memory_backend_get_align, 230 file_memory_backend_set_align, 231 NULL, NULL); 232 object_class_property_add(oc, "offset", "int", 233 file_memory_backend_get_offset, 234 file_memory_backend_set_offset, 235 NULL, NULL); 236 object_class_property_set_description(oc, "offset", 237 "Offset into the target file (ex: 1G)"); 238 #ifdef CONFIG_LIBPMEM 239 object_class_property_add_bool(oc, "pmem", 240 file_memory_backend_get_pmem, file_memory_backend_set_pmem); 241 #endif 242 object_class_property_add_bool(oc, "readonly", 243 file_memory_backend_get_readonly, 244 file_memory_backend_set_readonly); 245 } 246 247 static void file_backend_instance_finalize(Object *o) 248 { 249 HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); 250 251 g_free(fb->mem_path); 252 } 253 254 static const TypeInfo file_backend_info = { 255 .name = TYPE_MEMORY_BACKEND_FILE, 256 .parent = TYPE_MEMORY_BACKEND, 257 .class_init = file_backend_class_init, 258 .instance_finalize = file_backend_instance_finalize, 259 .instance_size = sizeof(HostMemoryBackendFile), 260 }; 261 262 static void register_types(void) 263 { 264 type_register_static(&file_backend_info); 265 } 266 267 type_init(register_types); 268