qmp.c

   1 /*
   2  * QEMU Management Protocol
   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.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  * Contributions after 2012-01-13 are licensed under the terms of the
  13  * GNU GPL, version 2 or (at your option) any later version.
  14  */
  15
  16 #include "qemu-common.h"
  17 #include "sysemu/sysemu.h"
  18 #include "qmp-commands.h"
  19 #include "sysemu/char.h"
  20 #include "ui/qemu-spice.h"
  21 #include "ui/vnc.h"
  22 #include "sysemu/kvm.h"
  23 #include "sysemu/arch_init.h"
  24 #include "hw/qdev.h"
  25 #include "sysemu/blockdev.h"
  26 #include "qom/qom-qobject.h"
  27 #include "qapi/qmp/qobject.h"
  28 #include "qapi/qmp-input-visitor.h"
  29 #include "hw/boards.h"
  30 #include "qom/object_interfaces.h"
  31 #include "hw/mem/pc-dimm.h"
  32 #include "hw/acpi/acpi_dev_interface.h"
  33
  34 NameInfo *qmp_query_name(Error **errp)
  35 {
  36     NameInfo *info = g_malloc0(sizeof(*info));
  37
  38     if (qemu_name) {
  39         info->has_name = true;
  40         info->name = g_strdup(qemu_name);
  41     }
  42
  43     return info;
  44 }
  45
  46 VersionInfo *qmp_query_version(Error **errp)
  47 {
  48     VersionInfo *info = g_new0(VersionInfo, 1);
  49     const char *version = QEMU_VERSION;
  50     char *tmp;
  51
  52     info->qemu = g_new0(VersionTriple, 1);
  53     info->qemu->major = strtol(version, &tmp, 10);
  54     tmp++;
  55     info->qemu->minor = strtol(tmp, &tmp, 10);
  56     tmp++;
  57     info->qemu->micro = strtol(tmp, &tmp, 10);
  58     info->package = g_strdup(QEMU_PKGVERSION);
  59
  60     return info;
  61 }
  62
  63 KvmInfo *qmp_query_kvm(Error **errp)
  64 {
  65     KvmInfo *info = g_malloc0(sizeof(*info));
  66
  67     info->enabled = kvm_enabled();
  68     info->present = kvm_available();
  69
  70     return info;
  71 }
  72
  73 UuidInfo *qmp_query_uuid(Error **errp)
  74 {
  75     UuidInfo *info = g_malloc0(sizeof(*info));
  76     char uuid[64];
  77
  78     snprintf(uuid, sizeof(uuid), UUID_FMT, qemu_uuid[0], qemu_uuid[1],
  79                    qemu_uuid[2], qemu_uuid[3], qemu_uuid[4], qemu_uuid[5],
  80                    qemu_uuid[6], qemu_uuid[7], qemu_uuid[8], qemu_uuid[9],
  81                    qemu_uuid[10], qemu_uuid[11], qemu_uuid[12], qemu_uuid[13],
  82                    qemu_uuid[14], qemu_uuid[15]);
  83
  84     info->UUID = g_strdup(uuid);
  85     return info;
  86 }
  87
  88 void qmp_quit(Error **errp)
  89 {
  90     no_shutdown = 0;
  91     qemu_system_shutdown_request();
  92 }
  93
  94 void qmp_stop(Error **errp)
  95 {
  96     if (runstate_check(RUN_STATE_INMIGRATE)) {
  97         autostart = 0;
  98     } else {
  99         vm_stop(RUN_STATE_PAUSED);
 100     }
 101 }
 102
 103 void qmp_system_reset(Error **errp)
 104 {
 105     qemu_system_reset_request();
 106 }
 107
 108 void qmp_system_powerdown(Error **erp)
 109 {
 110     qemu_system_powerdown_request();
 111 }
 112
 113 void qmp_cpu(int64_t index, Error **errp)
 114 {
 115     /* Just do nothing */
 116 }
 117
 118 void qmp_cpu_add(int64_t id, Error **errp)
 119 {
 120     MachineClass *mc;
 121
 122     mc = MACHINE_GET_CLASS(current_machine);
 123     if (mc->hot_add_cpu) {
 124         mc->hot_add_cpu(id, errp);
 125     } else {
 126         error_setg(errp, "Not supported");
 127     }
 128 }
 129
 130 #ifndef CONFIG_VNC
 131 /* If VNC support is enabled, the "true" query-vnc command is
 132    defined in the VNC subsystem */
 133 VncInfo *qmp_query_vnc(Error **errp)
 134 {
 135     error_set(errp, QERR_FEATURE_DISABLED, "vnc");
 136     return NULL;
 137 };
 138
 139 VncInfo2List *qmp_query_vnc_servers(Error **errp)
 140 {
 141     error_set(errp, QERR_FEATURE_DISABLED, "vnc");
 142     return NULL;
 143 };
 144 #endif
 145
 146 #ifndef CONFIG_SPICE
 147 /*
 148  * qmp-commands.hx ensures that QMP command query-spice exists only
 149  * #ifdef CONFIG_SPICE.  Necessary for an accurate query-commands
 150  * result.  However, the QAPI schema is blissfully unaware of that,
 151  * and the QAPI code generator happily generates a dead
 152  * qmp_marshal_input_query_spice() that calls qmp_query_spice().
 153  * Provide it one, or else linking fails.
 154  * FIXME Educate the QAPI schema on CONFIG_SPICE.
 155  */
 156 SpiceInfo *qmp_query_spice(Error **errp)
 157 {
 158     abort();
 159 };
 160 #endif
 161
 162 void qmp_cont(Error **errp)
 163 {
 164     Error *local_err = NULL;
 165     BlockDriverState *bs;
 166
 167     if (runstate_needs_reset()) {
 168         error_setg(errp, "Resetting the Virtual Machine is required");
 169         return;
 170     } else if (runstate_check(RUN_STATE_SUSPENDED)) {
 171         return;
 172     }
 173
 174     for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
 175         bdrv_iostatus_reset(bs);
 176     }
 177     for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
 178         bdrv_add_key(bs, NULL, &local_err);
 179         if (local_err) {
 180             error_propagate(errp, local_err);
 181             return;
 182         }
 183     }
 184
 185     if (runstate_check(RUN_STATE_INMIGRATE)) {
 186         autostart = 1;
 187     } else {
 188         vm_start();
 189     }
 190 }
 191
 192 void qmp_system_wakeup(Error **errp)
 193 {
 194     qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
 195 }
 196
 197 ObjectPropertyInfoList *qmp_qom_list(const char *path, Error **errp)
 198 {
 199     Object *obj;
 200     bool ambiguous = false;
 201     ObjectPropertyInfoList *props = NULL;
 202     ObjectProperty *prop;
 203
 204     obj = object_resolve_path(path, &ambiguous);
 205     if (obj == NULL) {
 206         if (ambiguous) {
 207             error_setg(errp, "Path '%s' is ambiguous", path);
 208         } else {
 209             error_set(errp, QERR_DEVICE_NOT_FOUND, path);
 210         }
 211         return NULL;
 212     }
 213
 214     QTAILQ_FOREACH(prop, &obj->properties, node) {
 215         ObjectPropertyInfoList *entry = g_malloc0(sizeof(*entry));
 216
 217         entry->value = g_malloc0(sizeof(ObjectPropertyInfo));
 218         entry->next = props;
 219         props = entry;
 220
 221         entry->value->name = g_strdup(prop->name);
 222         entry->value->type = g_strdup(prop->type);
 223     }
 224
 225     return props;
 226 }
 227
 228 /* FIXME: teach qapi about how to pass through Visitors */
 229 int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret)
 230 {
 231     const char *path = qdict_get_str(qdict, "path");
 232     const char *property = qdict_get_str(qdict, "property");
 233     QObject *value = qdict_get(qdict, "value");
 234     Error *local_err = NULL;
 235     Object *obj;
 236
 237     obj = object_resolve_path(path, NULL);
 238     if (!obj) {
 239         error_set(&local_err, QERR_DEVICE_NOT_FOUND, path);
 240         goto out;
 241     }
 242
 243     object_property_set_qobject(obj, value, property, &local_err);
 244
 245 out:
 246     if (local_err) {
 247         qerror_report_err(local_err);
 248         error_free(local_err);
 249         return -1;
 250     }
 251
 252     return 0;
 253 }
 254
 255 int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret)
 256 {
 257     const char *path = qdict_get_str(qdict, "path");
 258     const char *property = qdict_get_str(qdict, "property");
 259     Error *local_err = NULL;
 260     Object *obj;
 261
 262     obj = object_resolve_path(path, NULL);
 263     if (!obj) {
 264         error_set(&local_err, QERR_DEVICE_NOT_FOUND, path);
 265         goto out;
 266     }
 267
 268     *ret = object_property_get_qobject(obj, property, &local_err);
 269
 270 out:
 271     if (local_err) {
 272         qerror_report_err(local_err);
 273         error_free(local_err);
 274         return -1;
 275     }
 276
 277     return 0;
 278 }
 279
 280 void qmp_set_password(const char *protocol, const char *password,
 281                       bool has_connected, const char *connected, Error **errp)
 282 {
 283     int disconnect_if_connected = 0;
 284     int fail_if_connected = 0;
 285     int rc;
 286
 287     if (has_connected) {
 288         if (strcmp(connected, "fail") == 0) {
 289             fail_if_connected = 1;
 290         } else if (strcmp(connected, "disconnect") == 0) {
 291             disconnect_if_connected = 1;
 292         } else if (strcmp(connected, "keep") == 0) {
 293             /* nothing */
 294         } else {
 295             error_set(errp, QERR_INVALID_PARAMETER, "connected");
 296             return;
 297         }
 298     }
 299
 300     if (strcmp(protocol, "spice") == 0) {
 301         if (!qemu_using_spice(errp)) {
 302             return;
 303         }
 304         rc = qemu_spice_set_passwd(password, fail_if_connected,
 305                                    disconnect_if_connected);
 306         if (rc != 0) {
 307             error_set(errp, QERR_SET_PASSWD_FAILED);
 308         }
 309         return;
 310     }
 311
 312     if (strcmp(protocol, "vnc") == 0) {
 313         if (fail_if_connected || disconnect_if_connected) {
 314             /* vnc supports "connected=keep" only */
 315             error_set(errp, QERR_INVALID_PARAMETER, "connected");
 316             return;
 317         }
 318         /* Note that setting an empty password will not disable login through
 319          * this interface. */
 320         rc = vnc_display_password(NULL, password);
 321         if (rc < 0) {
 322             error_set(errp, QERR_SET_PASSWD_FAILED);
 323         }
 324         return;
 325     }
 326
 327     error_set(errp, QERR_INVALID_PARAMETER, "protocol");
 328 }
 329
 330 void qmp_expire_password(const char *protocol, const char *whenstr,
 331                          Error **errp)
 332 {
 333     time_t when;
 334     int rc;
 335
 336     if (strcmp(whenstr, "now") == 0) {
 337         when = 0;
 338     } else if (strcmp(whenstr, "never") == 0) {
 339         when = TIME_MAX;
 340     } else if (whenstr[0] == '+') {
 341         when = time(NULL) + strtoull(whenstr+1, NULL, 10);
 342     } else {
 343         when = strtoull(whenstr, NULL, 10);
 344     }
 345
 346     if (strcmp(protocol, "spice") == 0) {
 347         if (!qemu_using_spice(errp)) {
 348             return;
 349         }
 350         rc = qemu_spice_set_pw_expire(when);
 351         if (rc != 0) {
 352             error_set(errp, QERR_SET_PASSWD_FAILED);
 353         }
 354         return;
 355     }
 356
 357     if (strcmp(protocol, "vnc") == 0) {
 358         rc = vnc_display_pw_expire(NULL, when);
 359         if (rc != 0) {
 360             error_set(errp, QERR_SET_PASSWD_FAILED);
 361         }
 362         return;
 363     }
 364
 365     error_set(errp, QERR_INVALID_PARAMETER, "protocol");
 366 }
 367
 368 #ifdef CONFIG_VNC
 369 void qmp_change_vnc_password(const char *password, Error **errp)
 370 {
 371     if (vnc_display_password(NULL, password) < 0) {
 372         error_set(errp, QERR_SET_PASSWD_FAILED);
 373     }
 374 }
 375
 376 static void qmp_change_vnc_listen(const char *target, Error **errp)
 377 {
 378     QemuOptsList *olist = qemu_find_opts("vnc");
 379     QemuOpts *opts;
 380
 381     if (strstr(target, "id=")) {
 382         error_setg(errp, "id not supported");
 383         return;
 384     }
 385
 386     opts = qemu_opts_find(olist, "default");
 387     if (opts) {
 388         qemu_opts_del(opts);
 389     }
 390     opts = vnc_parse_func(target);
 391     if (!opts) {
 392         return;
 393     }
 394
 395     vnc_display_open("default", errp);
 396 }
 397
 398 static void qmp_change_vnc(const char *target, bool has_arg, const char *arg,
 399                            Error **errp)
 400 {
 401     if (strcmp(target, "passwd") == 0 || strcmp(target, "password") == 0) {
 402         if (!has_arg) {
 403             error_set(errp, QERR_MISSING_PARAMETER, "password");
 404         } else {
 405             qmp_change_vnc_password(arg, errp);
 406         }
 407     } else {
 408         qmp_change_vnc_listen(target, errp);
 409     }
 410 }
 411 #else
 412 void qmp_change_vnc_password(const char *password, Error **errp)
 413 {
 414     error_set(errp, QERR_FEATURE_DISABLED, "vnc");
 415 }
 416 static void qmp_change_vnc(const char *target, bool has_arg, const char *arg,
 417                            Error **errp)
 418 {
 419     error_set(errp, QERR_FEATURE_DISABLED, "vnc");
 420 }
 421 #endif /* !CONFIG_VNC */
 422
 423 void qmp_change(const char *device, const char *target,
 424                 bool has_arg, const char *arg, Error **errp)
 425 {
 426     if (strcmp(device, "vnc") == 0) {
 427         qmp_change_vnc(target, has_arg, arg, errp);
 428     } else {
 429         qmp_change_blockdev(device, target, arg, errp);
 430     }
 431 }
 432
 433 static void qom_list_types_tramp(ObjectClass *klass, void *data)
 434 {
 435     ObjectTypeInfoList *e, **pret = data;
 436     ObjectTypeInfo *info;
 437
 438     info = g_malloc0(sizeof(*info));
 439     info->name = g_strdup(object_class_get_name(klass));
 440
 441     e = g_malloc0(sizeof(*e));
 442     e->value = info;
 443     e->next = *pret;
 444     *pret = e;
 445 }
 446
 447 ObjectTypeInfoList *qmp_qom_list_types(bool has_implements,
 448                                        const char *implements,
 449                                        bool has_abstract,
 450                                        bool abstract,
 451                                        Error **errp)
 452 {
 453     ObjectTypeInfoList *ret = NULL;
 454
 455     object_class_foreach(qom_list_types_tramp, implements, abstract, &ret);
 456
 457     return ret;
 458 }
 459
 460 /* Return a DevicePropertyInfo for a qdev property.
 461  *
 462  * If a qdev property with the given name does not exist, use the given default
 463  * type.  If the qdev property info should not be shown, return NULL.
 464  *
 465  * The caller must free the return value.
 466  */
 467 static DevicePropertyInfo *make_device_property_info(ObjectClass *klass,
 468                                                      const char *name,
 469                                                      const char *default_type,
 470                                                      const char *description)
 471 {
 472     DevicePropertyInfo *info;
 473     Property *prop;
 474
 475     do {
 476         for (prop = DEVICE_CLASS(klass)->props; prop && prop->name; prop++) {
 477             if (strcmp(name, prop->name) != 0) {
 478                 continue;
 479             }
 480
 481             /*
 482              * TODO Properties without a parser are just for dirty hacks.
 483              * qdev_prop_ptr is the only such PropertyInfo.  It's marked
 484              * for removal.  This conditional should be removed along with
 485              * it.
 486              */
 487             if (!prop->info->set) {
 488                 return NULL;           /* no way to set it, don't show */
 489             }
 490
 491             info = g_malloc0(sizeof(*info));
 492             info->name = g_strdup(prop->name);
 493             info->type = g_strdup(prop->info->name);
 494             info->has_description = !!prop->info->description;
 495             info->description = g_strdup(prop->info->description);
 496             return info;
 497         }
 498         klass = object_class_get_parent(klass);
 499     } while (klass != object_class_by_name(TYPE_DEVICE));
 500
 501     /* Not a qdev property, use the default type */
 502     info = g_malloc0(sizeof(*info));
 503     info->name = g_strdup(name);
 504     info->type = g_strdup(default_type);
 505     info->has_description = !!description;
 506     info->description = g_strdup(description);
 507
 508     return info;
 509 }
 510
 511 DevicePropertyInfoList *qmp_device_list_properties(const char *typename,
 512                                                    Error **errp)
 513 {
 514     ObjectClass *klass;
 515     Object *obj;
 516     ObjectProperty *prop;
 517     DevicePropertyInfoList *prop_list = NULL;
 518
 519     klass = object_class_by_name(typename);
 520     if (klass == NULL) {
 521         error_set(errp, QERR_DEVICE_NOT_FOUND, typename);
 522         return NULL;
 523     }
 524
 525     klass = object_class_dynamic_cast(klass, TYPE_DEVICE);
 526     if (klass == NULL) {
 527         error_set(errp, QERR_INVALID_PARAMETER_VALUE,
 528                   "name", TYPE_DEVICE);
 529         return NULL;
 530     }
 531
 532     obj = object_new(typename);
 533
 534     QTAILQ_FOREACH(prop, &obj->properties, node) {
 535         DevicePropertyInfo *info;
 536         DevicePropertyInfoList *entry;
 537
 538         /* Skip Object and DeviceState properties */
 539         if (strcmp(prop->name, "type") == 0 ||
 540             strcmp(prop->name, "realized") == 0 ||
 541             strcmp(prop->name, "hotpluggable") == 0 ||
 542             strcmp(prop->name, "hotplugged") == 0 ||
 543             strcmp(prop->name, "parent_bus") == 0) {
 544             continue;
 545         }
 546
 547         /* Skip legacy properties since they are just string versions of
 548          * properties that we already list.
 549          */
 550         if (strstart(prop->name, "legacy-", NULL)) {
 551             continue;
 552         }
 553
 554         info = make_device_property_info(klass, prop->name, prop->type,
 555                                          prop->description);
 556         if (!info) {
 557             continue;
 558         }
 559
 560         entry = g_malloc0(sizeof(*entry));
 561         entry->value = info;
 562         entry->next = prop_list;
 563         prop_list = entry;
 564     }
 565
 566     object_unref(obj);
 567
 568     return prop_list;
 569 }
 570
 571 CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
 572 {
 573     return arch_query_cpu_definitions(errp);
 574 }
 575
 576 void qmp_add_client(const char *protocol, const char *fdname,
 577                     bool has_skipauth, bool skipauth, bool has_tls, bool tls,
 578                     Error **errp)
 579 {
 580     CharDriverState *s;
 581     int fd;
 582
 583     fd = monitor_get_fd(cur_mon, fdname, errp);
 584     if (fd < 0) {
 585         return;
 586     }
 587
 588     if (strcmp(protocol, "spice") == 0) {
 589         if (!qemu_using_spice(errp)) {
 590             close(fd);
 591             return;
 592         }
 593         skipauth = has_skipauth ? skipauth : false;
 594         tls = has_tls ? tls : false;
 595         if (qemu_spice_display_add_client(fd, skipauth, tls) < 0) {
 596             error_setg(errp, "spice failed to add client");
 597             close(fd);
 598         }
 599         return;
 600 #ifdef CONFIG_VNC
 601     } else if (strcmp(protocol, "vnc") == 0) {
 602         skipauth = has_skipauth ? skipauth : false;
 603         vnc_display_add_client(NULL, fd, skipauth);
 604         return;
 605 #endif
 606     } else if ((s = qemu_chr_find(protocol)) != NULL) {
 607         if (qemu_chr_add_client(s, fd) < 0) {
 608             error_setg(errp, "failed to add client");
 609             close(fd);
 610             return;
 611         }
 612         return;
 613     }
 614
 615     error_setg(errp, "protocol '%s' is invalid", protocol);
 616     close(fd);
 617 }
 618
 619 void object_add(const char *type, const char *id, const QDict *qdict,
 620                 Visitor *v, Error **errp)
 621 {
 622     Object *obj;
 623     ObjectClass *klass;
 624     const QDictEntry *e;
 625     Error *local_err = NULL;
 626
 627     klass = object_class_by_name(type);
 628     if (!klass) {
 629         error_setg(errp, "invalid object type: %s", type);
 630         return;
 631     }
 632
 633     if (!object_class_dynamic_cast(klass, TYPE_USER_CREATABLE)) {
 634         error_setg(errp, "object type '%s' isn't supported by object-add",
 635                    type);
 636         return;
 637     }
 638
 639     if (object_class_is_abstract(klass)) {
 640         error_setg(errp, "object type '%s' is abstract", type);
 641         return;
 642     }
 643
 644     obj = object_new(type);
 645     if (qdict) {
 646         for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
 647             object_property_set(obj, v, e->key, &local_err);
 648             if (local_err) {
 649                 goto out;
 650             }
 651         }
 652     }
 653
 654     object_property_add_child(container_get(object_get_root(), "/objects"),
 655                               id, obj, &local_err);
 656     if (local_err) {
 657         goto out;
 658     }
 659
 660     user_creatable_complete(obj, &local_err);
 661     if (local_err) {
 662         object_property_del(container_get(object_get_root(), "/objects"),
 663                             id, &error_abort);
 664         goto out;
 665     }
 666 out:
 667     if (local_err) {
 668         error_propagate(errp, local_err);
 669     }
 670     object_unref(obj);
 671 }
 672
 673 int qmp_object_add(Monitor *mon, const QDict *qdict, QObject **ret)
 674 {
 675     const char *type = qdict_get_str(qdict, "qom-type");
 676     const char *id = qdict_get_str(qdict, "id");
 677     QObject *props = qdict_get(qdict, "props");
 678     const QDict *pdict = NULL;
 679     Error *local_err = NULL;
 680     QmpInputVisitor *qiv;
 681
 682     if (props) {
 683         pdict = qobject_to_qdict(props);
 684         if (!pdict) {
 685             error_set(&local_err, QERR_INVALID_PARAMETER_TYPE, "props", "dict");
 686             goto out;
 687         }
 688     }
 689
 690     qiv = qmp_input_visitor_new(props);
 691     object_add(type, id, pdict, qmp_input_get_visitor(qiv), &local_err);
 692     qmp_input_visitor_cleanup(qiv);
 693
 694 out:
 695     if (local_err) {
 696         qerror_report_err(local_err);
 697         error_free(local_err);
 698         return -1;
 699     }
 700
 701     return 0;
 702 }
 703
 704 void qmp_object_del(const char *id, Error **errp)
 705 {
 706     Object *container;
 707     Object *obj;
 708
 709     container = container_get(object_get_root(), "/objects");
 710     obj = object_resolve_path_component(container, id);
 711     if (!obj) {
 712         error_setg(errp, "object id not found");
 713         return;
 714     }
 715
 716     if (!user_creatable_can_be_deleted(USER_CREATABLE(obj), errp)) {
 717         error_setg(errp, "%s is in use, can not be deleted", id);
 718         return;
 719     }
 720     object_unparent(obj);
 721 }
 722
 723 MemoryDeviceInfoList *qmp_query_memory_devices(Error **errp)
 724 {
 725     MemoryDeviceInfoList *head = NULL;
 726     MemoryDeviceInfoList **prev = &head;
 727
 728     qmp_pc_dimm_device_list(qdev_get_machine(), &prev);
 729
 730     return head;
 731 }
 732
 733 ACPIOSTInfoList *qmp_query_acpi_ospm_status(Error **errp)
 734 {
 735     bool ambig;
 736     ACPIOSTInfoList *head = NULL;
 737     ACPIOSTInfoList **prev = &head;
 738     Object *obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, &ambig);
 739
 740     if (obj) {
 741         AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(obj);
 742         AcpiDeviceIf *adev = ACPI_DEVICE_IF(obj);
 743
 744         adevc->ospm_status(adev, &prev);
 745     } else {
 746         error_setg(errp, "command is not supported, missing ACPI device");
 747     }
 748
 749     return head;
 750 }