qom/object.c

   1 /*
   2  * QEMU Object Model
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.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 "hw/qdev-core.h"
  15 #include "qapi/error.h"
  16 #include "qom/object.h"
  17 #include "qom/object_interfaces.h"
  18 #include "qemu/cutils.h"
  19 #include "qapi/visitor.h"
  20 #include "qapi/string-input-visitor.h"
  21 #include "qapi/string-output-visitor.h"
  22 #include "qapi/qapi-builtin-visit.h"
  23 #include "qapi/qmp/qerror.h"
  24 #include "trace.h"
  25
  26 /* TODO: replace QObject with a simpler visitor to avoid a dependency
  27  * of the QOM core on QObject?  */
  28 #include "qom/qom-qobject.h"
  29 #include "qapi/qmp/qbool.h"
  30 #include "qapi/qmp/qnum.h"
  31 #include "qapi/qmp/qstring.h"
  32 #include "qemu/error-report.h"
  33
  34 #define MAX_INTERFACES 32
  35
  36 typedef struct InterfaceImpl InterfaceImpl;
  37 typedef struct TypeImpl TypeImpl;
  38
  39 struct InterfaceImpl
  40 {
  41     const char *typename;
  42 };
  43
  44 struct TypeImpl
  45 {
  46     const char *name;
  47
  48     size_t class_size;
  49
  50     size_t instance_size;
  51
  52     void (*class_init)(ObjectClass *klass, void *data);
  53     void (*class_base_init)(ObjectClass *klass, void *data);
  54
  55     void *class_data;
  56
  57     void (*instance_init)(Object *obj);
  58     void (*instance_post_init)(Object *obj);
  59     void (*instance_finalize)(Object *obj);
  60
  61     bool abstract;
  62
  63     const char *parent;
  64     TypeImpl *parent_type;
  65
  66     ObjectClass *class;
  67
  68     int num_interfaces;
  69     InterfaceImpl interfaces[MAX_INTERFACES];
  70 };
  71
  72 static Type type_interface;
  73
  74 static GHashTable *type_table_get(void)
  75 {
  76     static GHashTable *type_table;
  77
  78     if (type_table == NULL) {
  79         type_table = g_hash_table_new(g_str_hash, g_str_equal);
  80     }
  81
  82     return type_table;
  83 }
  84
  85 static bool enumerating_types;
  86
  87 static void type_table_add(TypeImpl *ti)
  88 {
  89     assert(!enumerating_types);
  90     g_hash_table_insert(type_table_get(), (void *)ti->name, ti);
  91 }
  92
  93 static TypeImpl *type_table_lookup(const char *name)
  94 {
  95     return g_hash_table_lookup(type_table_get(), name);
  96 }
  97
  98 static TypeImpl *type_new(const TypeInfo *info)
  99 {
 100     TypeImpl *ti = g_malloc0(sizeof(*ti));
 101     int i;
 102
 103     g_assert(info->name != NULL);
 104
 105     if (type_table_lookup(info->name) != NULL) {
 106         fprintf(stderr, "Registering `%s' which already exists\n", info->name);
 107         abort();
 108     }
 109
 110     ti->name = g_strdup(info->name);
 111     ti->parent = g_strdup(info->parent);
 112
 113     ti->class_size = info->class_size;
 114     ti->instance_size = info->instance_size;
 115
 116     ti->class_init = info->class_init;
 117     ti->class_base_init = info->class_base_init;
 118     ti->class_data = info->class_data;
 119
 120     ti->instance_init = info->instance_init;
 121     ti->instance_post_init = info->instance_post_init;
 122     ti->instance_finalize = info->instance_finalize;
 123
 124     ti->abstract = info->abstract;
 125
 126     for (i = 0; info->interfaces && info->interfaces[i].type; i++) {
 127         ti->interfaces[i].typename = g_strdup(info->interfaces[i].type);
 128     }
 129     ti->num_interfaces = i;
 130
 131     return ti;
 132 }
 133
 134 static TypeImpl *type_register_internal(const TypeInfo *info)
 135 {
 136     TypeImpl *ti;
 137     ti = type_new(info);
 138
 139     type_table_add(ti);
 140     return ti;
 141 }
 142
 143 TypeImpl *type_register(const TypeInfo *info)
 144 {
 145     assert(info->parent);
 146     return type_register_internal(info);
 147 }
 148
 149 TypeImpl *type_register_static(const TypeInfo *info)
 150 {
 151     return type_register(info);
 152 }
 153
 154 void type_register_static_array(const TypeInfo *infos, int nr_infos)
 155 {
 156     int i;
 157
 158     for (i = 0; i < nr_infos; i++) {
 159         type_register_static(&infos[i]);
 160     }
 161 }
 162
 163 static TypeImpl *type_get_by_name(const char *name)
 164 {
 165     if (name == NULL) {
 166         return NULL;
 167     }
 168
 169     return type_table_lookup(name);
 170 }
 171
 172 static TypeImpl *type_get_parent(TypeImpl *type)
 173 {
 174     if (!type->parent_type && type->parent) {
 175         type->parent_type = type_get_by_name(type->parent);
 176         g_assert(type->parent_type != NULL);
 177     }
 178
 179     return type->parent_type;
 180 }
 181
 182 static bool type_has_parent(TypeImpl *type)
 183 {
 184     return (type->parent != NULL);
 185 }
 186
 187 static size_t type_class_get_size(TypeImpl *ti)
 188 {
 189     if (ti->class_size) {
 190         return ti->class_size;
 191     }
 192
 193     if (type_has_parent(ti)) {
 194         return type_class_get_size(type_get_parent(ti));
 195     }
 196
 197     return sizeof(ObjectClass);
 198 }
 199
 200 static size_t type_object_get_size(TypeImpl *ti)
 201 {
 202     if (ti->instance_size) {
 203         return ti->instance_size;
 204     }
 205
 206     if (type_has_parent(ti)) {
 207         return type_object_get_size(type_get_parent(ti));
 208     }
 209
 210     return 0;
 211 }
 212
 213 size_t object_type_get_instance_size(const char *typename)
 214 {
 215     TypeImpl *type = type_get_by_name(typename);
 216
 217     g_assert(type != NULL);
 218     return type_object_get_size(type);
 219 }
 220
 221 static bool type_is_ancestor(TypeImpl *type, TypeImpl *target_type)
 222 {
 223     assert(target_type);
 224
 225     /* Check if target_type is a direct ancestor of type */
 226     while (type) {
 227         if (type == target_type) {
 228             return true;
 229         }
 230
 231         type = type_get_parent(type);
 232     }
 233
 234     return false;
 235 }
 236
 237 static void type_initialize(TypeImpl *ti);
 238
 239 static void type_initialize_interface(TypeImpl *ti, TypeImpl *interface_type,
 240                                       TypeImpl *parent_type)
 241 {
 242     InterfaceClass *new_iface;
 243     TypeInfo info = { };
 244     TypeImpl *iface_impl;
 245
 246     info.parent = parent_type->name;
 247     info.name = g_strdup_printf("%s::%s", ti->name, interface_type->name);
 248     info.abstract = true;
 249
 250     iface_impl = type_new(&info);
 251     iface_impl->parent_type = parent_type;
 252     type_initialize(iface_impl);
 253     g_free((char *)info.name);
 254
 255     new_iface = (InterfaceClass *)iface_impl->class;
 256     new_iface->concrete_class = ti->class;
 257     new_iface->interface_type = interface_type;
 258
 259     ti->class->interfaces = g_slist_append(ti->class->interfaces,
 260                                            iface_impl->class);
 261 }
 262
 263 static void object_property_free(gpointer data)
 264 {
 265     ObjectProperty *prop = data;
 266
 267     g_free(prop->name);
 268     g_free(prop->type);
 269     g_free(prop->description);
 270     g_free(prop);
 271 }
 272
 273 static void type_initialize(TypeImpl *ti)
 274 {
 275     TypeImpl *parent;
 276
 277     if (ti->class) {
 278         return;
 279     }
 280
 281     ti->class_size = type_class_get_size(ti);
 282     ti->instance_size = type_object_get_size(ti);
 283     /* Any type with zero instance_size is implicitly abstract.
 284      * This means interface types are all abstract.
 285      */
 286     if (ti->instance_size == 0) {
 287         ti->abstract = true;
 288     }
 289     if (type_is_ancestor(ti, type_interface)) {
 290         assert(ti->instance_size == 0);
 291         assert(ti->abstract);
 292         assert(!ti->instance_init);
 293         assert(!ti->instance_post_init);
 294         assert(!ti->instance_finalize);
 295         assert(!ti->num_interfaces);
 296     }
 297     ti->class = g_malloc0(ti->class_size);
 298
 299     parent = type_get_parent(ti);
 300     if (parent) {
 301         type_initialize(parent);
 302         GSList *e;
 303         int i;
 304
 305         g_assert(parent->class_size <= ti->class_size);
 306         memcpy(ti->class, parent->class, parent->class_size);
 307         ti->class->interfaces = NULL;
 308         ti->class->properties = g_hash_table_new_full(
 309             g_str_hash, g_str_equal, g_free, object_property_free);
 310
 311         for (e = parent->class->interfaces; e; e = e->next) {
 312             InterfaceClass *iface = e->data;
 313             ObjectClass *klass = OBJECT_CLASS(iface);
 314
 315             type_initialize_interface(ti, iface->interface_type, klass->type);
 316         }
 317
 318         for (i = 0; i < ti->num_interfaces; i++) {
 319             TypeImpl *t = type_get_by_name(ti->interfaces[i].typename);
 320             for (e = ti->class->interfaces; e; e = e->next) {
 321                 TypeImpl *target_type = OBJECT_CLASS(e->data)->type;
 322
 323                 if (type_is_ancestor(target_type, t)) {
 324                     break;
 325                 }
 326             }
 327
 328             if (e) {
 329                 continue;
 330             }
 331
 332             type_initialize_interface(ti, t, t);
 333         }
 334     } else {
 335         ti->class->properties = g_hash_table_new_full(
 336             g_str_hash, g_str_equal, g_free, object_property_free);
 337     }
 338
 339     ti->class->type = ti;
 340
 341     while (parent) {
 342         if (parent->class_base_init) {
 343             parent->class_base_init(ti->class, ti->class_data);
 344         }
 345         parent = type_get_parent(parent);
 346     }
 347
 348     if (ti->class_init) {
 349         ti->class_init(ti->class, ti->class_data);
 350     }
 351 }
 352
 353 static void object_init_with_type(Object *obj, TypeImpl *ti)
 354 {
 355     if (type_has_parent(ti)) {
 356         object_init_with_type(obj, type_get_parent(ti));
 357     }
 358
 359     if (ti->instance_init) {
 360         ti->instance_init(obj);
 361     }
 362 }
 363
 364 static void object_post_init_with_type(Object *obj, TypeImpl *ti)
 365 {
 366     if (ti->instance_post_init) {
 367         ti->instance_post_init(obj);
 368     }
 369
 370     if (type_has_parent(ti)) {
 371         object_post_init_with_type(obj, type_get_parent(ti));
 372     }
 373 }
 374
 375 void object_apply_global_props(Object *obj, const GPtrArray *props, Error **errp)
 376 {
 377     int i;
 378
 379     if (!props) {
 380         return;
 381     }
 382
 383     for (i = 0; i < props->len; i++) {
 384         GlobalProperty *p = g_ptr_array_index(props, i);
 385         Error *err = NULL;
 386
 387         if (object_dynamic_cast(obj, p->driver) == NULL) {
 388             continue;
 389         }
 390         if (p->optional && !object_property_find(obj, p->property, NULL)) {
 391             continue;
 392         }
 393         p->used = true;
 394         object_property_parse(obj, p->value, p->property, &err);
 395         if (err != NULL) {
 396             error_prepend(&err, "can't apply global %s.%s=%s: ",
 397                           p->driver, p->property, p->value);
 398             /*
 399              * If errp != NULL, propagate error and return.
 400              * If errp == NULL, report a warning, but keep going
 401              * with the remaining globals.
 402              */
 403             if (errp) {
 404                 error_propagate(errp, err);
 405                 return;
 406             } else {
 407                 warn_report_err(err);
 408             }
 409         }
 410     }
 411 }
 412
 413 /*
 414  * Global property defaults
 415  * Slot 0: accelerator's global property defaults
 416  * Slot 1: machine's global property defaults
 417  * Each is a GPtrArray of of GlobalProperty.
 418  * Applied in order, later entries override earlier ones.
 419  */
 420 static GPtrArray *object_compat_props[2];
 421
 422 /*
 423  * Set machine's global property defaults to @compat_props.
 424  * May be called at most once.
 425  */
 426 void object_set_machine_compat_props(GPtrArray *compat_props)
 427 {
 428     assert(!object_compat_props[1]);
 429     object_compat_props[1] = compat_props;
 430 }
 431
 432 /*
 433  * Set accelerator's global property defaults to @compat_props.
 434  * May be called at most once.
 435  */
 436 void object_set_accelerator_compat_props(GPtrArray *compat_props)
 437 {
 438     assert(!object_compat_props[0]);
 439     object_compat_props[0] = compat_props;
 440 }
 441
 442 void object_apply_compat_props(Object *obj)
 443 {
 444     int i;
 445
 446     for (i = 0; i < ARRAY_SIZE(object_compat_props); i++) {
 447         object_apply_global_props(obj, object_compat_props[i],
 448                                   &error_abort);
 449     }
 450 }
 451
 452 static void object_initialize_with_type(void *data, size_t size, TypeImpl *type)
 453 {
 454     Object *obj = data;
 455
 456     type_initialize(type);
 457
 458     g_assert(type->instance_size >= sizeof(Object));
 459     g_assert(type->abstract == false);
 460     g_assert(size >= type->instance_size);
 461
 462     memset(obj, 0, type->instance_size);
 463     obj->class = type->class;
 464     object_ref(obj);
 465     obj->properties = g_hash_table_new_full(g_str_hash, g_str_equal,
 466                                             NULL, object_property_free);
 467     object_init_with_type(obj, type);
 468     object_post_init_with_type(obj, type);
 469 }
 470
 471 void object_initialize(void *data, size_t size, const char *typename)
 472 {
 473     TypeImpl *type = type_get_by_name(typename);
 474
 475     if (!type) {
 476         error_report("missing object type '%s'", typename);
 477         abort();
 478     }
 479
 480     object_initialize_with_type(data, size, type);
 481 }
 482
 483 void object_initialize_child(Object *parentobj, const char *propname,
 484                              void *childobj, size_t size, const char *type,
 485                              Error **errp, ...)
 486 {
 487     va_list vargs;
 488
 489     va_start(vargs, errp);
 490     object_initialize_childv(parentobj, propname, childobj, size, type, errp,
 491                              vargs);
 492     va_end(vargs);
 493 }
 494
 495 void object_initialize_childv(Object *parentobj, const char *propname,
 496                               void *childobj, size_t size, const char *type,
 497                               Error **errp, va_list vargs)
 498 {
 499     Error *local_err = NULL;
 500     Object *obj;
 501     UserCreatable *uc;
 502
 503     object_initialize(childobj, size, type);
 504     obj = OBJECT(childobj);
 505
 506     object_set_propv(obj, &local_err, vargs);
 507     if (local_err) {
 508         goto out;
 509     }
 510
 511     object_property_add_child(parentobj, propname, obj, &local_err);
 512     if (local_err) {
 513         goto out;
 514     }
 515
 516     uc = (UserCreatable *)object_dynamic_cast(obj, TYPE_USER_CREATABLE);
 517     if (uc) {
 518         user_creatable_complete(uc, &local_err);
 519         if (local_err) {
 520             object_unparent(obj);
 521             goto out;
 522         }
 523     }
 524
 525     /*
 526      * Since object_property_add_child added a reference to the child object,
 527      * we can drop the reference added by object_initialize(), so the child
 528      * property will own the only reference to the object.
 529      */
 530     object_unref(obj);
 531
 532 out:
 533     if (local_err) {
 534         error_propagate(errp, local_err);
 535         object_unref(obj);
 536     }
 537 }
 538
 539 static inline bool object_property_is_child(ObjectProperty *prop)
 540 {
 541     return strstart(prop->type, "child<", NULL);
 542 }
 543
 544 static void object_property_del_all(Object *obj)
 545 {
 546     ObjectProperty *prop;
 547     GHashTableIter iter;
 548     gpointer key, value;
 549     bool released;
 550
 551     do {
 552         released = false;
 553         g_hash_table_iter_init(&iter, obj->properties);
 554         while (g_hash_table_iter_next(&iter, &key, &value)) {
 555             prop = value;
 556             if (prop->release) {
 557                 prop->release(obj, prop->name, prop->opaque);
 558                 prop->release = NULL;
 559                 released = true;
 560                 break;
 561             }
 562             g_hash_table_iter_remove(&iter);
 563         }
 564     } while (released);
 565
 566     g_hash_table_unref(obj->properties);
 567 }
 568
 569 static void object_property_del_child(Object *obj, Object *child, Error **errp)
 570 {
 571     ObjectProperty *prop;
 572     GHashTableIter iter;
 573     gpointer key, value;
 574
 575     g_hash_table_iter_init(&iter, obj->properties);
 576     while (g_hash_table_iter_next(&iter, &key, &value)) {
 577         prop = value;
 578         if (object_property_is_child(prop) && prop->opaque == child) {
 579             if (prop->release) {
 580                 prop->release(obj, prop->name, prop->opaque);
 581                 prop->release = NULL;
 582             }
 583             break;
 584         }
 585     }
 586     g_hash_table_iter_init(&iter, obj->properties);
 587     while (g_hash_table_iter_next(&iter, &key, &value)) {
 588         prop = value;
 589         if (object_property_is_child(prop) && prop->opaque == child) {
 590             g_hash_table_iter_remove(&iter);
 591             break;
 592         }
 593     }
 594 }
 595
 596 void object_unparent(Object *obj)
 597 {
 598     if (obj->parent) {
 599         object_property_del_child(obj->parent, obj, NULL);
 600     }
 601 }
 602
 603 static void object_deinit(Object *obj, TypeImpl *type)
 604 {
 605     if (type->instance_finalize) {
 606         type->instance_finalize(obj);
 607     }
 608
 609     if (type_has_parent(type)) {
 610         object_deinit(obj, type_get_parent(type));
 611     }
 612 }
 613
 614 static void object_finalize(void *data)
 615 {
 616     Object *obj = data;
 617     TypeImpl *ti = obj->class->type;
 618
 619     object_property_del_all(obj);
 620     object_deinit(obj, ti);
 621
 622     g_assert(obj->ref == 0);
 623     if (obj->free) {
 624         obj->free(obj);
 625     }
 626 }
 627
 628 static Object *object_new_with_type(Type type)
 629 {
 630     Object *obj;
 631
 632     g_assert(type != NULL);
 633     type_initialize(type);
 634
 635     obj = g_malloc(type->instance_size);
 636     object_initialize_with_type(obj, type->instance_size, type);
 637     obj->free = g_free;
 638
 639     return obj;
 640 }
 641
 642 Object *object_new(const char *typename)
 643 {
 644     TypeImpl *ti = type_get_by_name(typename);
 645
 646     return object_new_with_type(ti);
 647 }
 648
 649
 650 Object *object_new_with_props(const char *typename,
 651                               Object *parent,
 652                               const char *id,
 653                               Error **errp,
 654                               ...)
 655 {
 656     va_list vargs;
 657     Object *obj;
 658
 659     va_start(vargs, errp);
 660     obj = object_new_with_propv(typename, parent, id, errp, vargs);
 661     va_end(vargs);
 662
 663     return obj;
 664 }
 665
 666
 667 Object *object_new_with_propv(const char *typename,
 668                               Object *parent,
 669                               const char *id,
 670                               Error **errp,
 671                               va_list vargs)
 672 {
 673     Object *obj;
 674     ObjectClass *klass;
 675     Error *local_err = NULL;
 676     UserCreatable *uc;
 677
 678     klass = object_class_by_name(typename);
 679     if (!klass) {
 680         error_setg(errp, "invalid object type: %s", typename);
 681         return NULL;
 682     }
 683
 684     if (object_class_is_abstract(klass)) {
 685         error_setg(errp, "object type '%s' is abstract", typename);
 686         return NULL;
 687     }
 688     obj = object_new_with_type(klass->type);
 689
 690     if (object_set_propv(obj, &local_err, vargs) < 0) {
 691         goto error;
 692     }
 693
 694     if (id != NULL) {
 695         object_property_add_child(parent, id, obj, &local_err);
 696         if (local_err) {
 697             goto error;
 698         }
 699     }
 700
 701     uc = (UserCreatable *)object_dynamic_cast(obj, TYPE_USER_CREATABLE);
 702     if (uc) {
 703         user_creatable_complete(uc, &local_err);
 704         if (local_err) {
 705             if (id != NULL) {
 706                 object_unparent(obj);
 707             }
 708             goto error;
 709         }
 710     }
 711
 712     object_unref(OBJECT(obj));
 713     return obj;
 714
 715  error:
 716     error_propagate(errp, local_err);
 717     object_unref(obj);
 718     return NULL;
 719 }
 720
 721
 722 int object_set_props(Object *obj,
 723                      Error **errp,
 724                      ...)
 725 {
 726     va_list vargs;
 727     int ret;
 728
 729     va_start(vargs, errp);
 730     ret = object_set_propv(obj, errp, vargs);
 731     va_end(vargs);
 732
 733     return ret;
 734 }
 735
 736
 737 int object_set_propv(Object *obj,
 738                      Error **errp,
 739                      va_list vargs)
 740 {
 741     const char *propname;
 742     Error *local_err = NULL;
 743
 744     propname = va_arg(vargs, char *);
 745     while (propname != NULL) {
 746         const char *value = va_arg(vargs, char *);
 747
 748         g_assert(value != NULL);
 749         object_property_parse(obj, value, propname, &local_err);
 750         if (local_err) {
 751             error_propagate(errp, local_err);
 752             return -1;
 753         }
 754         propname = va_arg(vargs, char *);
 755     }
 756
 757     return 0;
 758 }
 759
 760
 761 Object *object_dynamic_cast(Object *obj, const char *typename)
 762 {
 763     if (obj && object_class_dynamic_cast(object_get_class(obj), typename)) {
 764         return obj;
 765     }
 766
 767     return NULL;
 768 }
 769
 770 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
 771                                    const char *file, int line, const char *func)
 772 {
 773     trace_object_dynamic_cast_assert(obj ? obj->class->type->name : "(null)",
 774                                      typename, file, line, func);
 775
 776 #ifdef CONFIG_QOM_CAST_DEBUG
 777     int i;
 778     Object *inst;
 779
 780     for (i = 0; obj && i < OBJECT_CLASS_CAST_CACHE; i++) {
 781         if (atomic_read(&obj->class->object_cast_cache[i]) == typename) {
 782             goto out;
 783         }
 784     }
 785
 786     inst = object_dynamic_cast(obj, typename);
 787
 788     if (!inst && obj) {
 789         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 790                 file, line, func, obj, typename);
 791         abort();
 792     }
 793
 794     assert(obj == inst);
 795
 796     if (obj && obj == inst) {
 797         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 798             atomic_set(&obj->class->object_cast_cache[i - 1],
 799                        atomic_read(&obj->class->object_cast_cache[i]));
 800         }
 801         atomic_set(&obj->class->object_cast_cache[i - 1], typename);
 802     }
 803
 804 out:
 805 #endif
 806     return obj;
 807 }
 808
 809 ObjectClass *object_class_dynamic_cast(ObjectClass *class,
 810                                        const char *typename)
 811 {
 812     ObjectClass *ret = NULL;
 813     TypeImpl *target_type;
 814     TypeImpl *type;
 815
 816     if (!class) {
 817         return NULL;
 818     }
 819
 820     /* A simple fast path that can trigger a lot for leaf classes.  */
 821     type = class->type;
 822     if (type->name == typename) {
 823         return class;
 824     }
 825
 826     target_type = type_get_by_name(typename);
 827     if (!target_type) {
 828         /* target class type unknown, so fail the cast */
 829         return NULL;
 830     }
 831
 832     if (type->class->interfaces &&
 833             type_is_ancestor(target_type, type_interface)) {
 834         int found = 0;
 835         GSList *i;
 836
 837         for (i = class->interfaces; i; i = i->next) {
 838             ObjectClass *target_class = i->data;
 839
 840             if (type_is_ancestor(target_class->type, target_type)) {
 841                 ret = target_class;
 842                 found++;
 843             }
 844          }
 845
 846         /* The match was ambiguous, don't allow a cast */
 847         if (found > 1) {
 848             ret = NULL;
 849         }
 850     } else if (type_is_ancestor(type, target_type)) {
 851         ret = class;
 852     }
 853
 854     return ret;
 855 }
 856
 857 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
 858                                               const char *typename,
 859                                               const char *file, int line,
 860                                               const char *func)
 861 {
 862     ObjectClass *ret;
 863
 864     trace_object_class_dynamic_cast_assert(class ? class->type->name : "(null)",
 865                                            typename, file, line, func);
 866
 867 #ifdef CONFIG_QOM_CAST_DEBUG
 868     int i;
 869
 870     for (i = 0; class && i < OBJECT_CLASS_CAST_CACHE; i++) {
 871         if (atomic_read(&class->class_cast_cache[i]) == typename) {
 872             ret = class;
 873             goto out;
 874         }
 875     }
 876 #else
 877     if (!class || !class->interfaces) {
 878         return class;
 879     }
 880 #endif
 881
 882     ret = object_class_dynamic_cast(class, typename);
 883     if (!ret && class) {
 884         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 885                 file, line, func, class, typename);
 886         abort();
 887     }
 888
 889 #ifdef CONFIG_QOM_CAST_DEBUG
 890     if (class && ret == class) {
 891         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 892             atomic_set(&class->class_cast_cache[i - 1],
 893                        atomic_read(&class->class_cast_cache[i]));
 894         }
 895         atomic_set(&class->class_cast_cache[i - 1], typename);
 896     }
 897 out:
 898 #endif
 899     return ret;
 900 }
 901
 902 const char *object_get_typename(const Object *obj)
 903 {
 904     return obj->class->type->name;
 905 }
 906
 907 ObjectClass *object_get_class(Object *obj)
 908 {
 909     return obj->class;
 910 }
 911
 912 bool object_class_is_abstract(ObjectClass *klass)
 913 {
 914     return klass->type->abstract;
 915 }
 916
 917 const char *object_class_get_name(ObjectClass *klass)
 918 {
 919     return klass->type->name;
 920 }
 921
 922 ObjectClass *object_class_by_name(const char *typename)
 923 {
 924     TypeImpl *type = type_get_by_name(typename);
 925
 926     if (!type) {
 927         return NULL;
 928     }
 929
 930     type_initialize(type);
 931
 932     return type->class;
 933 }
 934
 935 ObjectClass *object_class_get_parent(ObjectClass *class)
 936 {
 937     TypeImpl *type = type_get_parent(class->type);
 938
 939     if (!type) {
 940         return NULL;
 941     }
 942
 943     type_initialize(type);
 944
 945     return type->class;
 946 }
 947
 948 typedef struct OCFData
 949 {
 950     void (*fn)(ObjectClass *klass, void *opaque);
 951     const char *implements_type;
 952     bool include_abstract;
 953     void *opaque;
 954 } OCFData;
 955
 956 static void object_class_foreach_tramp(gpointer key, gpointer value,
 957                                        gpointer opaque)
 958 {
 959     OCFData *data = opaque;
 960     TypeImpl *type = value;
 961     ObjectClass *k;
 962
 963     type_initialize(type);
 964     k = type->class;
 965
 966     if (!data->include_abstract && type->abstract) {
 967         return;
 968     }
 969
 970     if (data->implements_type &&
 971         !object_class_dynamic_cast(k, data->implements_type)) {
 972         return;
 973     }
 974
 975     data->fn(k, data->opaque);
 976 }
 977
 978 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 979                           const char *implements_type, bool include_abstract,
 980                           void *opaque)
 981 {
 982     OCFData data = { fn, implements_type, include_abstract, opaque };
 983
 984     enumerating_types = true;
 985     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
 986     enumerating_types = false;
 987 }
 988
 989 static int do_object_child_foreach(Object *obj,
 990                                    int (*fn)(Object *child, void *opaque),
 991                                    void *opaque, bool recurse)
 992 {
 993     GHashTableIter iter;
 994     ObjectProperty *prop;
 995     int ret = 0;
 996
 997     g_hash_table_iter_init(&iter, obj->properties);
 998     while (g_hash_table_iter_next(&iter, NULL, (gpointer *)&prop)) {
 999         if (object_property_is_child(prop)) {
1000             Object *child = prop->opaque;
1001
1002             ret = fn(child, opaque);
1003             if (ret != 0) {
1004                 break;
1005             }
1006             if (recurse) {
1007                 do_object_child_foreach(child, fn, opaque, true);
1008             }
1009         }
1010     }
1011     return ret;
1012 }
1013
1014 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
1015                          void *opaque)
1016 {
1017     return do_object_child_foreach(obj, fn, opaque, false);
1018 }
1019
1020 int object_child_foreach_recursive(Object *obj,
1021                                    int (*fn)(Object *child, void *opaque),
1022                                    void *opaque)
1023 {
1024     return do_object_child_foreach(obj, fn, opaque, true);
1025 }
1026
1027 static void object_class_get_list_tramp(ObjectClass *klass, void *opaque)
1028 {
1029     GSList **list = opaque;
1030
1031     *list = g_slist_prepend(*list, klass);
1032 }
1033
1034 GSList *object_class_get_list(const char *implements_type,
1035                               bool include_abstract)
1036 {
1037     GSList *list = NULL;
1038
1039     object_class_foreach(object_class_get_list_tramp,
1040                          implements_type, include_abstract, &list);
1041     return list;
1042 }
1043
1044 static gint object_class_cmp(gconstpointer a, gconstpointer b)
1045 {
1046     return strcasecmp(object_class_get_name((ObjectClass *)a),
1047                       object_class_get_name((ObjectClass *)b));
1048 }
1049
1050 GSList *object_class_get_list_sorted(const char *implements_type,
1051                                      bool include_abstract)
1052 {
1053     return g_slist_sort(object_class_get_list(implements_type, include_abstract),
1054                         object_class_cmp);
1055 }
1056
1057 void object_ref(Object *obj)
1058 {
1059     if (!obj) {
1060         return;
1061     }
1062     atomic_inc(&obj->ref);
1063 }
1064
1065 void object_unref(Object *obj)
1066 {
1067     if (!obj) {
1068         return;
1069     }
1070     g_assert(obj->ref > 0);
1071
1072     /* parent always holds a reference to its children */
1073     if (atomic_fetch_dec(&obj->ref) == 1) {
1074         object_finalize(obj);
1075     }
1076 }
1077
1078 ObjectProperty *
1079 object_property_add(Object *obj, const char *name, const char *type,
1080                     ObjectPropertyAccessor *get,
1081                     ObjectPropertyAccessor *set,
1082                     ObjectPropertyRelease *release,
1083                     void *opaque, Error **errp)
1084 {
1085     ObjectProperty *prop;
1086     size_t name_len = strlen(name);
1087
1088     if (name_len >= 3 && !memcmp(name + name_len - 3, "[*]", 4)) {
1089         int i;
1090         ObjectProperty *ret;
1091         char *name_no_array = g_strdup(name);
1092
1093         name_no_array[name_len - 3] = '\0';
1094         for (i = 0; ; ++i) {
1095             char *full_name = g_strdup_printf("%s[%d]", name_no_array, i);
1096
1097             ret = object_property_add(obj, full_name, type, get, set,
1098                                       release, opaque, NULL);
1099             g_free(full_name);
1100             if (ret) {
1101                 break;
1102             }
1103         }
1104         g_free(name_no_array);
1105         return ret;
1106     }
1107
1108     if (object_property_find(obj, name, NULL) != NULL) {
1109         error_setg(errp, "attempt to add duplicate property '%s'"
1110                    " to object (type '%s')", name,
1111                    object_get_typename(obj));
1112         return NULL;
1113     }
1114
1115     prop = g_malloc0(sizeof(*prop));
1116
1117     prop->name = g_strdup(name);
1118     prop->type = g_strdup(type);
1119
1120     prop->get = get;
1121     prop->set = set;
1122     prop->release = release;
1123     prop->opaque = opaque;
1124
1125     g_hash_table_insert(obj->properties, prop->name, prop);
1126     return prop;
1127 }
1128
1129 ObjectProperty *
1130 object_class_property_add(ObjectClass *klass,
1131                           const char *name,
1132                           const char *type,
1133                           ObjectPropertyAccessor *get,
1134                           ObjectPropertyAccessor *set,
1135                           ObjectPropertyRelease *release,
1136                           void *opaque,
1137                           Error **errp)
1138 {
1139     ObjectProperty *prop;
1140
1141     if (object_class_property_find(klass, name, NULL) != NULL) {
1142         error_setg(errp, "attempt to add duplicate property '%s'"
1143                    " to object (type '%s')", name,
1144                    object_class_get_name(klass));
1145         return NULL;
1146     }
1147
1148     prop = g_malloc0(sizeof(*prop));
1149
1150     prop->name = g_strdup(name);
1151     prop->type = g_strdup(type);
1152
1153     prop->get = get;
1154     prop->set = set;
1155     prop->release = release;
1156     prop->opaque = opaque;
1157
1158     g_hash_table_insert(klass->properties, g_strdup(name), prop);
1159
1160     return prop;
1161 }
1162
1163 ObjectProperty *object_property_find(Object *obj, const char *name,
1164                                      Error **errp)
1165 {
1166     ObjectProperty *prop;
1167     ObjectClass *klass = object_get_class(obj);
1168
1169     prop = object_class_property_find(klass, name, NULL);
1170     if (prop) {
1171         return prop;
1172     }
1173
1174     prop = g_hash_table_lookup(obj->properties, name);
1175     if (prop) {
1176         return prop;
1177     }
1178
1179     error_setg(errp, "Property '.%s' not found", name);
1180     return NULL;
1181 }
1182
1183 void object_property_iter_init(ObjectPropertyIterator *iter,
1184                                Object *obj)
1185 {
1186     g_hash_table_iter_init(&iter->iter, obj->properties);
1187     iter->nextclass = object_get_class(obj);
1188 }
1189
1190 ObjectProperty *object_property_iter_next(ObjectPropertyIterator *iter)
1191 {
1192     gpointer key, val;
1193     while (!g_hash_table_iter_next(&iter->iter, &key, &val)) {
1194         if (!iter->nextclass) {
1195             return NULL;
1196         }
1197         g_hash_table_iter_init(&iter->iter, iter->nextclass->properties);
1198         iter->nextclass = object_class_get_parent(iter->nextclass);
1199     }
1200     return val;
1201 }
1202
1203 void object_class_property_iter_init(ObjectPropertyIterator *iter,
1204                                      ObjectClass *klass)
1205 {
1206     g_hash_table_iter_init(&iter->iter, klass->properties);
1207     iter->nextclass = object_class_get_parent(klass);
1208 }
1209
1210 ObjectProperty *object_class_property_find(ObjectClass *klass, const char *name,
1211                                            Error **errp)
1212 {
1213     ObjectProperty *prop;
1214     ObjectClass *parent_klass;
1215
1216     parent_klass = object_class_get_parent(klass);
1217     if (parent_klass) {
1218         prop = object_class_property_find(parent_klass, name, NULL);
1219         if (prop) {
1220             return prop;
1221         }
1222     }
1223
1224     prop = g_hash_table_lookup(klass->properties, name);
1225     if (!prop) {
1226         error_setg(errp, "Property '.%s' not found", name);
1227     }
1228     return prop;
1229 }
1230
1231 void object_property_del(Object *obj, const char *name, Error **errp)
1232 {
1233     ObjectProperty *prop = g_hash_table_lookup(obj->properties, name);
1234
1235     if (!prop) {
1236         error_setg(errp, "Property '.%s' not found", name);
1237         return;
1238     }
1239
1240     if (prop->release) {
1241         prop->release(obj, name, prop->opaque);
1242     }
1243     g_hash_table_remove(obj->properties, name);
1244 }
1245
1246 void object_property_get(Object *obj, Visitor *v, const char *name,
1247                          Error **errp)
1248 {
1249     ObjectProperty *prop = object_property_find(obj, name, errp);
1250     if (prop == NULL) {
1251         return;
1252     }
1253
1254     if (!prop->get) {
1255         error_setg(errp, QERR_PERMISSION_DENIED);
1256     } else {
1257         prop->get(obj, v, name, prop->opaque, errp);
1258     }
1259 }
1260
1261 void object_property_set(Object *obj, Visitor *v, const char *name,
1262                          Error **errp)
1263 {
1264     ObjectProperty *prop = object_property_find(obj, name, errp);
1265     if (prop == NULL) {
1266         return;
1267     }
1268
1269     if (!prop->set) {
1270         error_setg(errp, QERR_PERMISSION_DENIED);
1271     } else {
1272         prop->set(obj, v, name, prop->opaque, errp);
1273     }
1274 }
1275
1276 void object_property_set_str(Object *obj, const char *value,
1277                              const char *name, Error **errp)
1278 {
1279     QString *qstr = qstring_from_str(value);
1280     object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
1281
1282     qobject_unref(qstr);
1283 }
1284
1285 char *object_property_get_str(Object *obj, const char *name,
1286                               Error **errp)
1287 {
1288     QObject *ret = object_property_get_qobject(obj, name, errp);
1289     char *retval;
1290
1291     if (!ret) {
1292         return NULL;
1293     }
1294
1295     retval = g_strdup(qobject_get_try_str(ret));
1296     if (!retval) {
1297         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
1298     }
1299
1300     qobject_unref(ret);
1301     return retval;
1302 }
1303
1304 void object_property_set_link(Object *obj, Object *value,
1305                               const char *name, Error **errp)
1306 {
1307     if (value) {
1308         gchar *path = object_get_canonical_path(value);
1309         object_property_set_str(obj, path, name, errp);
1310         g_free(path);
1311     } else {
1312         object_property_set_str(obj, "", name, errp);
1313     }
1314 }
1315
1316 Object *object_property_get_link(Object *obj, const char *name,
1317                                  Error **errp)
1318 {
1319     char *str = object_property_get_str(obj, name, errp);
1320     Object *target = NULL;
1321
1322     if (str && *str) {
1323         target = object_resolve_path(str, NULL);
1324         if (!target) {
1325             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1326                       "Device '%s' not found", str);
1327         }
1328     }
1329
1330     g_free(str);
1331     return target;
1332 }
1333
1334 void object_property_set_bool(Object *obj, bool value,
1335                               const char *name, Error **errp)
1336 {
1337     QBool *qbool = qbool_from_bool(value);
1338     object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
1339
1340     qobject_unref(qbool);
1341 }
1342
1343 bool object_property_get_bool(Object *obj, const char *name,
1344                               Error **errp)
1345 {
1346     QObject *ret = object_property_get_qobject(obj, name, errp);
1347     QBool *qbool;
1348     bool retval;
1349
1350     if (!ret) {
1351         return false;
1352     }
1353     qbool = qobject_to(QBool, ret);
1354     if (!qbool) {
1355         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
1356         retval = false;
1357     } else {
1358         retval = qbool_get_bool(qbool);
1359     }
1360
1361     qobject_unref(ret);
1362     return retval;
1363 }
1364
1365 void object_property_set_int(Object *obj, int64_t value,
1366                              const char *name, Error **errp)
1367 {
1368     QNum *qnum = qnum_from_int(value);
1369     object_property_set_qobject(obj, QOBJECT(qnum), name, errp);
1370
1371     qobject_unref(qnum);
1372 }
1373
1374 int64_t object_property_get_int(Object *obj, const char *name,
1375                                 Error **errp)
1376 {
1377     QObject *ret = object_property_get_qobject(obj, name, errp);
1378     QNum *qnum;
1379     int64_t retval;
1380
1381     if (!ret) {
1382         return -1;
1383     }
1384
1385     qnum = qobject_to(QNum, ret);
1386     if (!qnum || !qnum_get_try_int(qnum, &retval)) {
1387         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
1388         retval = -1;
1389     }
1390
1391     qobject_unref(ret);
1392     return retval;
1393 }
1394
1395 void object_property_set_uint(Object *obj, uint64_t value,
1396                               const char *name, Error **errp)
1397 {
1398     QNum *qnum = qnum_from_uint(value);
1399
1400     object_property_set_qobject(obj, QOBJECT(qnum), name, errp);
1401     qobject_unref(qnum);
1402 }
1403
1404 uint64_t object_property_get_uint(Object *obj, const char *name,
1405                                   Error **errp)
1406 {
1407     QObject *ret = object_property_get_qobject(obj, name, errp);
1408     QNum *qnum;
1409     uint64_t retval;
1410
1411     if (!ret) {
1412         return 0;
1413     }
1414     qnum = qobject_to(QNum, ret);
1415     if (!qnum || !qnum_get_try_uint(qnum, &retval)) {
1416         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name, "uint");
1417         retval = 0;
1418     }
1419
1420     qobject_unref(ret);
1421     return retval;
1422 }
1423
1424 typedef struct EnumProperty {
1425     const QEnumLookup *lookup;
1426     int (*get)(Object *, Error **);
1427     void (*set)(Object *, int, Error **);
1428 } EnumProperty;
1429
1430 int object_property_get_enum(Object *obj, const char *name,
1431                              const char *typename, Error **errp)
1432 {
1433     Error *err = NULL;
1434     Visitor *v;
1435     char *str;
1436     int ret;
1437     ObjectProperty *prop = object_property_find(obj, name, errp);
1438     EnumProperty *enumprop;
1439
1440     if (prop == NULL) {
1441         return 0;
1442     }
1443
1444     if (!g_str_equal(prop->type, typename)) {
1445         error_setg(errp, "Property %s on %s is not '%s' enum type",
1446                    name, object_class_get_name(
1447                        object_get_class(obj)), typename);
1448         return 0;
1449     }
1450
1451     enumprop = prop->opaque;
1452
1453     v = string_output_visitor_new(false, &str);
1454     object_property_get(obj, v, name, &err);
1455     if (err) {
1456         error_propagate(errp, err);
1457         visit_free(v);
1458         return 0;
1459     }
1460     visit_complete(v, &str);
1461     visit_free(v);
1462     v = string_input_visitor_new(str);
1463     visit_type_enum(v, name, &ret, enumprop->lookup, errp);
1464
1465     g_free(str);
1466     visit_free(v);
1467
1468     return ret;
1469 }
1470
1471 void object_property_get_uint16List(Object *obj, const char *name,
1472                                     uint16List **list, Error **errp)
1473 {
1474     Error *err = NULL;
1475     Visitor *v;
1476     char *str;
1477
1478     v = string_output_visitor_new(false, &str);
1479     object_property_get(obj, v, name, &err);
1480     if (err) {
1481         error_propagate(errp, err);
1482         goto out;
1483     }
1484     visit_complete(v, &str);
1485     visit_free(v);
1486     v = string_input_visitor_new(str);
1487     visit_type_uint16List(v, NULL, list, errp);
1488
1489     g_free(str);
1490 out:
1491     visit_free(v);
1492 }
1493
1494 void object_property_parse(Object *obj, const char *string,
1495                            const char *name, Error **errp)
1496 {
1497     Visitor *v = string_input_visitor_new(string);
1498     object_property_set(obj, v, name, errp);
1499     visit_free(v);
1500 }
1501
1502 char *object_property_print(Object *obj, const char *name, bool human,
1503                             Error **errp)
1504 {
1505     Visitor *v;
1506     char *string = NULL;
1507     Error *local_err = NULL;
1508
1509     v = string_output_visitor_new(human, &string);
1510     object_property_get(obj, v, name, &local_err);
1511     if (local_err) {
1512         error_propagate(errp, local_err);
1513         goto out;
1514     }
1515
1516     visit_complete(v, &string);
1517
1518 out:
1519     visit_free(v);
1520     return string;
1521 }
1522
1523 const char *object_property_get_type(Object *obj, const char *name, Error **errp)
1524 {
1525     ObjectProperty *prop = object_property_find(obj, name, errp);
1526     if (prop == NULL) {
1527         return NULL;
1528     }
1529
1530     return prop->type;
1531 }
1532
1533 Object *object_get_root(void)
1534 {
1535     static Object *root;
1536
1537     if (!root) {
1538         root = object_new("container");
1539     }
1540
1541     return root;
1542 }
1543
1544 Object *object_get_objects_root(void)
1545 {
1546     return container_get(object_get_root(), "/objects");
1547 }
1548
1549 Object *object_get_internal_root(void)
1550 {
1551     static Object *internal_root;
1552
1553     if (!internal_root) {
1554         internal_root = object_new("container");
1555     }
1556
1557     return internal_root;
1558 }
1559
1560 static void object_get_child_property(Object *obj, Visitor *v,
1561                                       const char *name, void *opaque,
1562                                       Error **errp)
1563 {
1564     Object *child = opaque;
1565     gchar *path;
1566
1567     path = object_get_canonical_path(child);
1568     visit_type_str(v, name, &path, errp);
1569     g_free(path);
1570 }
1571
1572 static Object *object_resolve_child_property(Object *parent, void *opaque, const gchar *part)
1573 {
1574     return opaque;
1575 }
1576
1577 static void object_finalize_child_property(Object *obj, const char *name,
1578                                            void *opaque)
1579 {
1580     Object *child = opaque;
1581
1582     if (child->class->unparent) {
1583         (child->class->unparent)(child);
1584     }
1585     child->parent = NULL;
1586     object_unref(child);
1587 }
1588
1589 void object_property_add_child(Object *obj, const char *name,
1590                                Object *child, Error **errp)
1591 {
1592     Error *local_err = NULL;
1593     gchar *type;
1594     ObjectProperty *op;
1595
1596     if (child->parent != NULL) {
1597         error_setg(errp, "child object is already parented");
1598         return;
1599     }
1600
1601     type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
1602
1603     op = object_property_add(obj, name, type, object_get_child_property, NULL,
1604                              object_finalize_child_property, child, &local_err);
1605     if (local_err) {
1606         error_propagate(errp, local_err);
1607         goto out;
1608     }
1609
1610     op->resolve = object_resolve_child_property;
1611     object_ref(child);
1612     child->parent = obj;
1613
1614 out:
1615     g_free(type);
1616 }
1617
1618 void object_property_allow_set_link(const Object *obj, const char *name,
1619                                     Object *val, Error **errp)
1620 {
1621     /* Allow the link to be set, always */
1622 }
1623
1624 typedef struct {
1625     Object **child;
1626     void (*check)(const Object *, const char *, Object *, Error **);
1627     ObjectPropertyLinkFlags flags;
1628 } LinkProperty;
1629
1630 static void object_get_link_property(Object *obj, Visitor *v,
1631                                      const char *name, void *opaque,
1632                                      Error **errp)
1633 {
1634     LinkProperty *lprop = opaque;
1635     Object **child = lprop->child;
1636     gchar *path;
1637
1638     if (*child) {
1639         path = object_get_canonical_path(*child);
1640         visit_type_str(v, name, &path, errp);
1641         g_free(path);
1642     } else {
1643         path = (gchar *)"";
1644         visit_type_str(v, name, &path, errp);
1645     }
1646 }
1647
1648 /*
1649  * object_resolve_link:
1650  *
1651  * Lookup an object and ensure its type matches the link property type.  This
1652  * is similar to object_resolve_path() except type verification against the
1653  * link property is performed.
1654  *
1655  * Returns: The matched object or NULL on path lookup failures.
1656  */
1657 static Object *object_resolve_link(Object *obj, const char *name,
1658                                    const char *path, Error **errp)
1659 {
1660     const char *type;
1661     gchar *target_type;
1662     bool ambiguous = false;
1663     Object *target;
1664
1665     /* Go from link<FOO> to FOO.  */
1666     type = object_property_get_type(obj, name, NULL);
1667     target_type = g_strndup(&type[5], strlen(type) - 6);
1668     target = object_resolve_path_type(path, target_type, &ambiguous);
1669
1670     if (ambiguous) {
1671         error_setg(errp, "Path '%s' does not uniquely identify an object",
1672                    path);
1673     } else if (!target) {
1674         target = object_resolve_path(path, &ambiguous);
1675         if (target || ambiguous) {
1676             error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
1677         } else {
1678             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
1679                       "Device '%s' not found", path);
1680         }
1681         target = NULL;
1682     }
1683     g_free(target_type);
1684
1685     return target;
1686 }
1687
1688 static void object_set_link_property(Object *obj, Visitor *v,
1689                                      const char *name, void *opaque,
1690                                      Error **errp)
1691 {
1692     Error *local_err = NULL;
1693     LinkProperty *prop = opaque;
1694     Object **child = prop->child;
1695     Object *old_target = *child;
1696     Object *new_target = NULL;
1697     char *path = NULL;
1698
1699     visit_type_str(v, name, &path, &local_err);
1700
1701     if (!local_err && strcmp(path, "") != 0) {
1702         new_target = object_resolve_link(obj, name, path, &local_err);
1703     }
1704
1705     g_free(path);
1706     if (local_err) {
1707         error_propagate(errp, local_err);
1708         return;
1709     }
1710
1711     prop->check(obj, name, new_target, &local_err);
1712     if (local_err) {
1713         error_propagate(errp, local_err);
1714         return;
1715     }
1716
1717     *child = new_target;
1718     if (prop->flags == OBJ_PROP_LINK_STRONG) {
1719         object_ref(new_target);
1720         object_unref(old_target);
1721     }
1722 }
1723
1724 static Object *object_resolve_link_property(Object *parent, void *opaque, const gchar *part)
1725 {
1726     LinkProperty *lprop = opaque;
1727
1728     return *lprop->child;
1729 }
1730
1731 static void object_release_link_property(Object *obj, const char *name,
1732                                          void *opaque)
1733 {
1734     LinkProperty *prop = opaque;
1735
1736     if ((prop->flags & OBJ_PROP_LINK_STRONG) && *prop->child) {
1737         object_unref(*prop->child);
1738     }
1739     g_free(prop);
1740 }
1741
1742 void object_property_add_link(Object *obj, const char *name,
1743                               const char *type, Object **child,
1744                               void (*check)(const Object *, const char *,
1745                                             Object *, Error **),
1746                               ObjectPropertyLinkFlags flags,
1747                               Error **errp)
1748 {
1749     Error *local_err = NULL;
1750     LinkProperty *prop = g_malloc(sizeof(*prop));
1751     gchar *full_type;
1752     ObjectProperty *op;
1753
1754     prop->child = child;
1755     prop->check = check;
1756     prop->flags = flags;
1757
1758     full_type = g_strdup_printf("link<%s>", type);
1759
1760     op = object_property_add(obj, name, full_type,
1761                              object_get_link_property,
1762                              check ? object_set_link_property : NULL,
1763                              object_release_link_property,
1764                              prop,
1765                              &local_err);
1766     if (local_err) {
1767         error_propagate(errp, local_err);
1768         g_free(prop);
1769         goto out;
1770     }
1771
1772     op->resolve = object_resolve_link_property;
1773
1774 out:
1775     g_free(full_type);
1776 }
1777
1778 void object_property_add_const_link(Object *obj, const char *name,
1779                                     Object *target, Error **errp)
1780 {
1781     char *link_type;
1782     ObjectProperty *op;
1783
1784     link_type = g_strdup_printf("link<%s>", object_get_typename(target));
1785     op = object_property_add(obj, name, link_type,
1786                              object_get_child_property, NULL,
1787                              NULL, target, errp);
1788     if (op != NULL) {
1789         op->resolve = object_resolve_child_property;
1790     }
1791     g_free(link_type);
1792 }
1793
1794 gchar *object_get_canonical_path_component(Object *obj)
1795 {
1796     ObjectProperty *prop = NULL;
1797     GHashTableIter iter;
1798
1799     if (obj->parent == NULL) {
1800         return NULL;
1801     }
1802
1803     g_hash_table_iter_init(&iter, obj->parent->properties);
1804     while (g_hash_table_iter_next(&iter, NULL, (gpointer *)&prop)) {
1805         if (!object_property_is_child(prop)) {
1806             continue;
1807         }
1808
1809         if (prop->opaque == obj) {
1810             return g_strdup(prop->name);
1811         }
1812     }
1813
1814     /* obj had a parent but was not a child, should never happen */
1815     g_assert_not_reached();
1816     return NULL;
1817 }
1818
1819 gchar *object_get_canonical_path(Object *obj)
1820 {
1821     Object *root = object_get_root();
1822     char *newpath, *path = NULL;
1823
1824     if (obj == root) {
1825         return g_strdup("/");
1826     }
1827
1828     do {
1829         char *component = object_get_canonical_path_component(obj);
1830
1831         if (!component) {
1832             /* A canonical path must be complete, so discard what was
1833              * collected so far.
1834              */
1835             g_free(path);
1836             return NULL;
1837         }
1838
1839         newpath = g_strdup_printf("/%s%s", component, path ? path : "");
1840         g_free(path);
1841         g_free(component);
1842         path = newpath;
1843         obj = obj->parent;
1844     } while (obj != root);
1845
1846     return path;
1847 }
1848
1849 Object *object_resolve_path_component(Object *parent, const gchar *part)
1850 {
1851     ObjectProperty *prop = object_property_find(parent, part, NULL);
1852     if (prop == NULL) {
1853         return NULL;
1854     }
1855
1856     if (prop->resolve) {
1857         return prop->resolve(parent, prop->opaque, part);
1858     } else {
1859         return NULL;
1860     }
1861 }
1862
1863 static Object *object_resolve_abs_path(Object *parent,
1864                                           gchar **parts,
1865                                           const char *typename,
1866                                           int index)
1867 {
1868     Object *child;
1869
1870     if (parts[index] == NULL) {
1871         return object_dynamic_cast(parent, typename);
1872     }
1873
1874     if (strcmp(parts[index], "") == 0) {
1875         return object_resolve_abs_path(parent, parts, typename, index + 1);
1876     }
1877
1878     child = object_resolve_path_component(parent, parts[index]);
1879     if (!child) {
1880         return NULL;
1881     }
1882
1883     return object_resolve_abs_path(child, parts, typename, index + 1);
1884 }
1885
1886 static Object *object_resolve_partial_path(Object *parent,
1887                                               gchar **parts,
1888                                               const char *typename,
1889                                               bool *ambiguous)
1890 {
1891     Object *obj;
1892     GHashTableIter iter;
1893     ObjectProperty *prop;
1894
1895     obj = object_resolve_abs_path(parent, parts, typename, 0);
1896
1897     g_hash_table_iter_init(&iter, parent->properties);
1898     while (g_hash_table_iter_next(&iter, NULL, (gpointer *)&prop)) {
1899         Object *found;
1900
1901         if (!object_property_is_child(prop)) {
1902             continue;
1903         }
1904
1905         found = object_resolve_partial_path(prop->opaque, parts,
1906                                             typename, ambiguous);
1907         if (found) {
1908             if (obj) {
1909                 *ambiguous = true;
1910                 return NULL;
1911             }
1912             obj = found;
1913         }
1914
1915         if (*ambiguous) {
1916             return NULL;
1917         }
1918     }
1919
1920     return obj;
1921 }
1922
1923 Object *object_resolve_path_type(const char *path, const char *typename,
1924                                  bool *ambiguousp)
1925 {
1926     Object *obj;
1927     gchar **parts;
1928
1929     parts = g_strsplit(path, "/", 0);
1930     assert(parts);
1931
1932     if (parts[0] == NULL || strcmp(parts[0], "") != 0) {
1933         bool ambiguous = false;
1934         obj = object_resolve_partial_path(object_get_root(), parts,
1935                                           typename, &ambiguous);
1936         if (ambiguousp) {
1937             *ambiguousp = ambiguous;
1938         }
1939     } else {
1940         obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
1941     }
1942
1943     g_strfreev(parts);
1944
1945     return obj;
1946 }
1947
1948 Object *object_resolve_path(const char *path, bool *ambiguous)
1949 {
1950     return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
1951 }
1952
1953 typedef struct StringProperty
1954 {
1955     char *(*get)(Object *, Error **);
1956     void (*set)(Object *, const char *, Error **);
1957 } StringProperty;
1958
1959 static void property_get_str(Object *obj, Visitor *v, const char *name,
1960                              void *opaque, Error **errp)
1961 {
1962     StringProperty *prop = opaque;
1963     char *value;
1964     Error *err = NULL;
1965
1966     value = prop->get(obj, &err);
1967     if (err) {
1968         error_propagate(errp, err);
1969         return;
1970     }
1971
1972     visit_type_str(v, name, &value, errp);
1973     g_free(value);
1974 }
1975
1976 static void property_set_str(Object *obj, Visitor *v, const char *name,
1977                              void *opaque, Error **errp)
1978 {
1979     StringProperty *prop = opaque;
1980     char *value;
1981     Error *local_err = NULL;
1982
1983     visit_type_str(v, name, &value, &local_err);
1984     if (local_err) {
1985         error_propagate(errp, local_err);
1986         return;
1987     }
1988
1989     prop->set(obj, value, errp);
1990     g_free(value);
1991 }
1992
1993 static void property_release_str(Object *obj, const char *name,
1994                                  void *opaque)
1995 {
1996     StringProperty *prop = opaque;
1997     g_free(prop);
1998 }
1999
2000 void object_property_add_str(Object *obj, const char *name,
2001                            char *(*get)(Object *, Error **),
2002                            void (*set)(Object *, const char *, Error **),
2003                            Error **errp)
2004 {
2005     Error *local_err = NULL;
2006     StringProperty *prop = g_malloc0(sizeof(*prop));
2007
2008     prop->get = get;
2009     prop->set = set;
2010
2011     object_property_add(obj, name, "string",
2012                         get ? property_get_str : NULL,
2013                         set ? property_set_str : NULL,
2014                         property_release_str,
2015                         prop, &local_err);
2016     if (local_err) {
2017         error_propagate(errp, local_err);
2018         g_free(prop);
2019     }
2020 }
2021
2022 void object_class_property_add_str(ObjectClass *klass, const char *name,
2023                                    char *(*get)(Object *, Error **),
2024                                    void (*set)(Object *, const char *,
2025                                                Error **),
2026                                    Error **errp)
2027 {
2028     Error *local_err = NULL;
2029     StringProperty *prop = g_malloc0(sizeof(*prop));
2030
2031     prop->get = get;
2032     prop->set = set;
2033
2034     object_class_property_add(klass, name, "string",
2035                               get ? property_get_str : NULL,
2036                               set ? property_set_str : NULL,
2037                               property_release_str,
2038                               prop, &local_err);
2039     if (local_err) {
2040         error_propagate(errp, local_err);
2041         g_free(prop);
2042     }
2043 }
2044
2045 typedef struct BoolProperty
2046 {
2047     bool (*get)(Object *, Error **);
2048     void (*set)(Object *, bool, Error **);
2049 } BoolProperty;
2050
2051 static void property_get_bool(Object *obj, Visitor *v, const char *name,
2052                               void *opaque, Error **errp)
2053 {
2054     BoolProperty *prop = opaque;
2055     bool value;
2056     Error *err = NULL;
2057
2058     value = prop->get(obj, &err);
2059     if (err) {
2060         error_propagate(errp, err);
2061         return;
2062     }
2063
2064     visit_type_bool(v, name, &value, errp);
2065 }
2066
2067 static void property_set_bool(Object *obj, Visitor *v, const char *name,
2068                               void *opaque, Error **errp)
2069 {
2070     BoolProperty *prop = opaque;
2071     bool value;
2072     Error *local_err = NULL;
2073
2074     visit_type_bool(v, name, &value, &local_err);
2075     if (local_err) {
2076         error_propagate(errp, local_err);
2077         return;
2078     }
2079
2080     prop->set(obj, value, errp);
2081 }
2082
2083 static void property_release_bool(Object *obj, const char *name,
2084                                   void *opaque)
2085 {
2086     BoolProperty *prop = opaque;
2087     g_free(prop);
2088 }
2089
2090 void object_property_add_bool(Object *obj, const char *name,
2091                               bool (*get)(Object *, Error **),
2092                               void (*set)(Object *, bool, Error **),
2093                               Error **errp)
2094 {
2095     Error *local_err = NULL;
2096     BoolProperty *prop = g_malloc0(sizeof(*prop));
2097
2098     prop->get = get;
2099     prop->set = set;
2100
2101     object_property_add(obj, name, "bool",
2102                         get ? property_get_bool : NULL,
2103                         set ? property_set_bool : NULL,
2104                         property_release_bool,
2105                         prop, &local_err);
2106     if (local_err) {
2107         error_propagate(errp, local_err);
2108         g_free(prop);
2109     }
2110 }
2111
2112 void object_class_property_add_bool(ObjectClass *klass, const char *name,
2113                                     bool (*get)(Object *, Error **),
2114                                     void (*set)(Object *, bool, Error **),
2115                                     Error **errp)
2116 {
2117     Error *local_err = NULL;
2118     BoolProperty *prop = g_malloc0(sizeof(*prop));
2119
2120     prop->get = get;
2121     prop->set = set;
2122
2123     object_class_property_add(klass, name, "bool",
2124                               get ? property_get_bool : NULL,
2125                               set ? property_set_bool : NULL,
2126                               property_release_bool,
2127                               prop, &local_err);
2128     if (local_err) {
2129         error_propagate(errp, local_err);
2130         g_free(prop);
2131     }
2132 }
2133
2134 static void property_get_enum(Object *obj, Visitor *v, const char *name,
2135                               void *opaque, Error **errp)
2136 {
2137     EnumProperty *prop = opaque;
2138     int value;
2139     Error *err = NULL;
2140
2141     value = prop->get(obj, &err);
2142     if (err) {
2143         error_propagate(errp, err);
2144         return;
2145     }
2146
2147     visit_type_enum(v, name, &value, prop->lookup, errp);
2148 }
2149
2150 static void property_set_enum(Object *obj, Visitor *v, const char *name,
2151                               void *opaque, Error **errp)
2152 {
2153     EnumProperty *prop = opaque;
2154     int value;
2155     Error *err = NULL;
2156
2157     visit_type_enum(v, name, &value, prop->lookup, &err);
2158     if (err) {
2159         error_propagate(errp, err);
2160         return;
2161     }
2162     prop->set(obj, value, errp);
2163 }
2164
2165 static void property_release_enum(Object *obj, const char *name,
2166                                   void *opaque)
2167 {
2168     EnumProperty *prop = opaque;
2169     g_free(prop);
2170 }
2171
2172 void object_property_add_enum(Object *obj, const char *name,
2173                               const char *typename,
2174                               const QEnumLookup *lookup,
2175                               int (*get)(Object *, Error **),
2176                               void (*set)(Object *, int, Error **),
2177                               Error **errp)
2178 {
2179     Error *local_err = NULL;
2180     EnumProperty *prop = g_malloc(sizeof(*prop));
2181
2182     prop->lookup = lookup;
2183     prop->get = get;
2184     prop->set = set;
2185
2186     object_property_add(obj, name, typename,
2187                         get ? property_get_enum : NULL,
2188                         set ? property_set_enum : NULL,
2189                         property_release_enum,
2190                         prop, &local_err);
2191     if (local_err) {
2192         error_propagate(errp, local_err);
2193         g_free(prop);
2194     }
2195 }
2196
2197 void object_class_property_add_enum(ObjectClass *klass, const char *name,
2198                                     const char *typename,
2199                                     const QEnumLookup *lookup,
2200                                     int (*get)(Object *, Error **),
2201                                     void (*set)(Object *, int, Error **),
2202                                     Error **errp)
2203 {
2204     Error *local_err = NULL;
2205     EnumProperty *prop = g_malloc(sizeof(*prop));
2206
2207     prop->lookup = lookup;
2208     prop->get = get;
2209     prop->set = set;
2210
2211     object_class_property_add(klass, name, typename,
2212                               get ? property_get_enum : NULL,
2213                               set ? property_set_enum : NULL,
2214                               property_release_enum,
2215                               prop, &local_err);
2216     if (local_err) {
2217         error_propagate(errp, local_err);
2218         g_free(prop);
2219     }
2220 }
2221
2222 typedef struct TMProperty {
2223     void (*get)(Object *, struct tm *, Error **);
2224 } TMProperty;
2225
2226 static void property_get_tm(Object *obj, Visitor *v, const char *name,
2227                             void *opaque, Error **errp)
2228 {
2229     TMProperty *prop = opaque;
2230     Error *err = NULL;
2231     struct tm value;
2232
2233     prop->get(obj, &value, &err);
2234     if (err) {
2235         goto out;
2236     }
2237
2238     visit_start_struct(v, name, NULL, 0, &err);
2239     if (err) {
2240         goto out;
2241     }
2242     visit_type_int32(v, "tm_year", &value.tm_year, &err);
2243     if (err) {
2244         goto out_end;
2245     }
2246     visit_type_int32(v, "tm_mon", &value.tm_mon, &err);
2247     if (err) {
2248         goto out_end;
2249     }
2250     visit_type_int32(v, "tm_mday", &value.tm_mday, &err);
2251     if (err) {
2252         goto out_end;
2253     }
2254     visit_type_int32(v, "tm_hour", &value.tm_hour, &err);
2255     if (err) {
2256         goto out_end;
2257     }
2258     visit_type_int32(v, "tm_min", &value.tm_min, &err);
2259     if (err) {
2260         goto out_end;
2261     }
2262     visit_type_int32(v, "tm_sec", &value.tm_sec, &err);
2263     if (err) {
2264         goto out_end;
2265     }
2266     visit_check_struct(v, &err);
2267 out_end:
2268     visit_end_struct(v, NULL);
2269 out:
2270     error_propagate(errp, err);
2271
2272 }
2273
2274 static void property_release_tm(Object *obj, const char *name,
2275                                 void *opaque)
2276 {
2277     TMProperty *prop = opaque;
2278     g_free(prop);
2279 }
2280
2281 void object_property_add_tm(Object *obj, const char *name,
2282                             void (*get)(Object *, struct tm *, Error **),
2283                             Error **errp)
2284 {
2285     Error *local_err = NULL;
2286     TMProperty *prop = g_malloc0(sizeof(*prop));
2287
2288     prop->get = get;
2289
2290     object_property_add(obj, name, "struct tm",
2291                         get ? property_get_tm : NULL, NULL,
2292                         property_release_tm,
2293                         prop, &local_err);
2294     if (local_err) {
2295         error_propagate(errp, local_err);
2296         g_free(prop);
2297     }
2298 }
2299
2300 void object_class_property_add_tm(ObjectClass *klass, const char *name,
2301                                   void (*get)(Object *, struct tm *, Error **),
2302                                   Error **errp)
2303 {
2304     Error *local_err = NULL;
2305     TMProperty *prop = g_malloc0(sizeof(*prop));
2306
2307     prop->get = get;
2308
2309     object_class_property_add(klass, name, "struct tm",
2310                               get ? property_get_tm : NULL, NULL,
2311                               property_release_tm,
2312                               prop, &local_err);
2313     if (local_err) {
2314         error_propagate(errp, local_err);
2315         g_free(prop);
2316     }
2317 }
2318
2319 static char *qdev_get_type(Object *obj, Error **errp)
2320 {
2321     return g_strdup(object_get_typename(obj));
2322 }
2323
2324 static void property_get_uint8_ptr(Object *obj, Visitor *v, const char *name,
2325                                    void *opaque, Error **errp)
2326 {
2327     uint8_t value = *(uint8_t *)opaque;
2328     visit_type_uint8(v, name, &value, errp);
2329 }
2330
2331 static void property_get_uint16_ptr(Object *obj, Visitor *v, const char *name,
2332                                     void *opaque, Error **errp)
2333 {
2334     uint16_t value = *(uint16_t *)opaque;
2335     visit_type_uint16(v, name, &value, errp);
2336 }
2337
2338 static void property_get_uint32_ptr(Object *obj, Visitor *v, const char *name,
2339                                     void *opaque, Error **errp)
2340 {
2341     uint32_t value = *(uint32_t *)opaque;
2342     visit_type_uint32(v, name, &value, errp);
2343 }
2344
2345 static void property_get_uint64_ptr(Object *obj, Visitor *v, const char *name,
2346                                     void *opaque, Error **errp)
2347 {
2348     uint64_t value = *(uint64_t *)opaque;
2349     visit_type_uint64(v, name, &value, errp);
2350 }
2351
2352 void object_property_add_uint8_ptr(Object *obj, const char *name,
2353                                    const uint8_t *v, Error **errp)
2354 {
2355     object_property_add(obj, name, "uint8", property_get_uint8_ptr,
2356                         NULL, NULL, (void *)v, errp);
2357 }
2358
2359 void object_class_property_add_uint8_ptr(ObjectClass *klass, const char *name,
2360                                          const uint8_t *v, Error **errp)
2361 {
2362     object_class_property_add(klass, name, "uint8", property_get_uint8_ptr,
2363                               NULL, NULL, (void *)v, errp);
2364 }
2365
2366 void object_property_add_uint16_ptr(Object *obj, const char *name,
2367                                     const uint16_t *v, Error **errp)
2368 {
2369     object_property_add(obj, name, "uint16", property_get_uint16_ptr,
2370                         NULL, NULL, (void *)v, errp);
2371 }
2372
2373 void object_class_property_add_uint16_ptr(ObjectClass *klass, const char *name,
2374                                           const uint16_t *v, Error **errp)
2375 {
2376     object_class_property_add(klass, name, "uint16", property_get_uint16_ptr,
2377                               NULL, NULL, (void *)v, errp);
2378 }
2379
2380 void object_property_add_uint32_ptr(Object *obj, const char *name,
2381                                     const uint32_t *v, Error **errp)
2382 {
2383     object_property_add(obj, name, "uint32", property_get_uint32_ptr,
2384                         NULL, NULL, (void *)v, errp);
2385 }
2386
2387 void object_class_property_add_uint32_ptr(ObjectClass *klass, const char *name,
2388                                           const uint32_t *v, Error **errp)
2389 {
2390     object_class_property_add(klass, name, "uint32", property_get_uint32_ptr,
2391                               NULL, NULL, (void *)v, errp);
2392 }
2393
2394 void object_property_add_uint64_ptr(Object *obj, const char *name,
2395                                     const uint64_t *v, Error **errp)
2396 {
2397     object_property_add(obj, name, "uint64", property_get_uint64_ptr,
2398                         NULL, NULL, (void *)v, errp);
2399 }
2400
2401 void object_class_property_add_uint64_ptr(ObjectClass *klass, const char *name,
2402                                           const uint64_t *v, Error **errp)
2403 {
2404     object_class_property_add(klass, name, "uint64", property_get_uint64_ptr,
2405                               NULL, NULL, (void *)v, errp);
2406 }
2407
2408 typedef struct {
2409     Object *target_obj;
2410     char *target_name;
2411 } AliasProperty;
2412
2413 static void property_get_alias(Object *obj, Visitor *v, const char *name,
2414                                void *opaque, Error **errp)
2415 {
2416     AliasProperty *prop = opaque;
2417
2418     object_property_get(prop->target_obj, v, prop->target_name, errp);
2419 }
2420
2421 static void property_set_alias(Object *obj, Visitor *v, const char *name,
2422                                void *opaque, Error **errp)
2423 {
2424     AliasProperty *prop = opaque;
2425
2426     object_property_set(prop->target_obj, v, prop->target_name, errp);
2427 }
2428
2429 static Object *property_resolve_alias(Object *obj, void *opaque,
2430                                       const gchar *part)
2431 {
2432     AliasProperty *prop = opaque;
2433
2434     return object_resolve_path_component(prop->target_obj, prop->target_name);
2435 }
2436
2437 static void property_release_alias(Object *obj, const char *name, void *opaque)
2438 {
2439     AliasProperty *prop = opaque;
2440
2441     g_free(prop->target_name);
2442     g_free(prop);
2443 }
2444
2445 void object_property_add_alias(Object *obj, const char *name,
2446                                Object *target_obj, const char *target_name,
2447                                Error **errp)
2448 {
2449     AliasProperty *prop;
2450     ObjectProperty *op;
2451     ObjectProperty *target_prop;
2452     gchar *prop_type;
2453     Error *local_err = NULL;
2454
2455     target_prop = object_property_find(target_obj, target_name, errp);
2456     if (!target_prop) {
2457         return;
2458     }
2459
2460     if (object_property_is_child(target_prop)) {
2461         prop_type = g_strdup_printf("link%s",
2462                                     target_prop->type + strlen("child"));
2463     } else {
2464         prop_type = g_strdup(target_prop->type);
2465     }
2466
2467     prop = g_malloc(sizeof(*prop));
2468     prop->target_obj = target_obj;
2469     prop->target_name = g_strdup(target_name);
2470
2471     op = object_property_add(obj, name, prop_type,
2472                              property_get_alias,
2473                              property_set_alias,
2474                              property_release_alias,
2475                              prop, &local_err);
2476     if (local_err) {
2477         error_propagate(errp, local_err);
2478         g_free(prop);
2479         goto out;
2480     }
2481     op->resolve = property_resolve_alias;
2482
2483     object_property_set_description(obj, op->name,
2484                                     target_prop->description,
2485                                     &error_abort);
2486
2487 out:
2488     g_free(prop_type);
2489 }
2490
2491 void object_property_set_description(Object *obj, const char *name,
2492                                      const char *description, Error **errp)
2493 {
2494     ObjectProperty *op;
2495
2496     op = object_property_find(obj, name, errp);
2497     if (!op) {
2498         return;
2499     }
2500
2501     g_free(op->description);
2502     op->description = g_strdup(description);
2503 }
2504
2505 void object_class_property_set_description(ObjectClass *klass,
2506                                            const char *name,
2507                                            const char *description,
2508                                            Error **errp)
2509 {
2510     ObjectProperty *op;
2511
2512     op = g_hash_table_lookup(klass->properties, name);
2513     if (!op) {
2514         error_setg(errp, "Property '.%s' not found", name);
2515         return;
2516     }
2517
2518     g_free(op->description);
2519     op->description = g_strdup(description);
2520 }
2521
2522 static void object_class_init(ObjectClass *klass, void *data)
2523 {
2524     object_class_property_add_str(klass, "type", qdev_get_type,
2525                                   NULL, &error_abort);
2526 }
2527
2528 static void register_types(void)
2529 {
2530     static TypeInfo interface_info = {
2531         .name = TYPE_INTERFACE,
2532         .class_size = sizeof(InterfaceClass),
2533         .abstract = true,
2534     };
2535
2536     static TypeInfo object_info = {
2537         .name = TYPE_OBJECT,
2538         .instance_size = sizeof(Object),
2539         .class_init = object_class_init,
2540         .abstract = true,
2541     };
2542
2543     type_interface = type_register_internal(&interface_info);
2544     type_register_internal(&object_info);
2545 }
2546
2547 type_init(register_types)