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_setg(errp, QERR_FEATURE_DISABLED, "vnc");
 136     return NULL;
 137 };
 138
 139 VncInfo2List *qmp_query_vnc_servers(Error **errp)
 140 {
 141     error_setg(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, ERROR_CLASS_DEVICE_NOT_FOUND,
 210                       "Device '%s' not found", path);
 211         }
 212         return NULL;
 213     }
 214
 215     QTAILQ_FOREACH(prop, &obj->properties, node) {
 216         ObjectPropertyInfoList *entry = g_malloc0(sizeof(*entry));
 217
 218         entry->value = g_malloc0(sizeof(ObjectPropertyInfo));
 219         entry->next = props;
 220         props = entry;
 221
 222         entry->value->name = g_strdup(prop->name);
 223         entry->value->type = g_strdup(prop->type);
 224     }
 225
 226     return props;
 227 }
 228
 229 /* FIXME: teach qapi about how to pass through Visitors */
 230 int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret)
 231 {
 232     const char *path = qdict_get_str(qdict, "path");
 233     const char *property = qdict_get_str(qdict, "property");
 234     QObject *value = qdict_get(qdict, "value");
 235     Error *local_err = NULL;
 236     Object *obj;
 237
 238     obj = object_resolve_path(path, NULL);
 239     if (!obj) {
 240         error_set(&local_err, ERROR_CLASS_DEVICE_NOT_FOUND,
 241                   "Device '%s' not found", path);
 242         goto out;
 243     }
 244
 245     object_property_set_qobject(obj, value, property, &local_err);
 246
 247 out:
 248     if (local_err) {
 249         qerror_report_err(local_err);
 250         error_free(local_err);
 251         return -1;
 252     }
 253
 254     return 0;
 255 }
 256
 257 int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret)
 258 {
 259     const char *path = qdict_get_str(qdict, "path");
 260     const char *property = qdict_get_str(qdict, "property");
 261     Error *local_err = NULL;
 262     Object *obj;
 263
 264     obj = object_resolve_path(path, NULL);
 265     if (!obj) {
 266         error_set(&local_err, ERROR_CLASS_DEVICE_NOT_FOUND,
 267                   "Device '%s' not found", path);
 268         goto out;
 269     }
 270
 271     *ret = object_property_get_qobject(obj, property, &local_err);
 272
 273 out:
 274     if (local_err) {
 275         qerror_report_err(local_err);
 276         error_free(local_err);
 277         return -1;
 278     }
 279
 280     return 0;
 281 }
 282
 283 void qmp_set_password(const char *protocol, const char *password,
 284                       bool has_connected, const char *connected, Error **errp)
 285 {
 286     int disconnect_if_connected = 0;
 287     int fail_if_connected = 0;
 288     int rc;
 289
 290     if (has_connected) {
 291         if (strcmp(connected, "fail") == 0) {
 292             fail_if_connected = 1;
 293         } else if (strcmp(connected, "disconnect") == 0) {
 294             disconnect_if_connected = 1;
 295         } else if (strcmp(connected, "keep") == 0) {
 296             /* nothing */
 297         } else {
 298             error_setg(errp, QERR_INVALID_PARAMETER, "connected");
 299             return;
 300         }
 301     }
 302
 303     if (strcmp(protocol, "spice") == 0) {
 304         if (!qemu_using_spice(errp)) {
 305             return;
 306         }
 307         rc = qemu_spice_set_passwd(password, fail_if_connected,
 308                                    disconnect_if_connected);
 309         if (rc != 0) {
 310             error_setg(errp, QERR_SET_PASSWD_FAILED);
 311         }
 312         return;
 313     }
 314
 315     if (strcmp(protocol, "vnc") == 0) {
 316         if (fail_if_connected || disconnect_if_connected) {
 317             /* vnc supports "connected=keep" only */
 318             error_setg(errp, QERR_INVALID_PARAMETER, "connected");
 319             return;
 320         }
 321         /* Note that setting an empty password will not disable login through
 322          * this interface. */
 323         rc = vnc_display_password(NULL, password);
 324         if (rc < 0) {
 325             error_setg(errp, QERR_SET_PASSWD_FAILED);
 326         }
 327         return;
 328     }
 329
 330     error_setg(errp, QERR_INVALID_PARAMETER, "protocol");
 331 }
 332
 333 void qmp_expire_password(const char *protocol, const char *whenstr,
 334                          Error **errp)
 335 {
 336     time_t when;
 337     int rc;
 338
 339     if (strcmp(whenstr, "now") == 0) {
 340         when = 0;
 341     } else if (strcmp(whenstr, "never") == 0) {
 342         when = TIME_MAX;
 343     } else if (whenstr[0] == '+') {
 344         when = time(NULL) + strtoull(whenstr+1, NULL, 10);
 345     } else {
 346         when = strtoull(whenstr, NULL, 10);
 347     }
 348
 349     if (strcmp(protocol, "spice") == 0) {
 350         if (!qemu_using_spice(errp)) {
 351             return;
 352         }
 353         rc = qemu_spice_set_pw_expire(when);
 354         if (rc != 0) {
 355             error_setg(errp, QERR_SET_PASSWD_FAILED);
 356         }
 357         return;
 358     }
 359
 360     if (strcmp(protocol, "vnc") == 0) {
 361         rc = vnc_display_pw_expire(NULL, when);
 362         if (rc != 0) {
 363             error_setg(errp, QERR_SET_PASSWD_FAILED);
 364         }
 365         return;
 366     }
 367
 368     error_setg(errp, QERR_INVALID_PARAMETER, "protocol");
 369 }
 370
 371 #ifdef CONFIG_VNC
 372 void qmp_change_vnc_password(const char *password, Error **errp)
 373 {
 374     if (vnc_display_password(NULL, password) < 0) {
 375         error_setg(errp, QERR_SET_PASSWD_FAILED);
 376     }
 377 }
 378
 379 static void qmp_change_vnc_listen(const char *target, Error **errp)
 380 {
 381     QemuOptsList *olist = qemu_find_opts("vnc");
 382     QemuOpts *opts;
 383
 384     if (strstr(target, "id=")) {
 385         error_setg(errp, "id not supported");
 386         return;
 387     }
 388
 389     opts = qemu_opts_find(olist, "default");
 390     if (opts) {
 391         qemu_opts_del(opts);
 392     }
 393     opts = vnc_parse(target, errp);
 394     if (!opts) {
 395         return;
 396     }
 397
 398     vnc_display_open("default", errp);
 399 }
 400
 401 static void qmp_change_vnc(const char *target, bool has_arg, const char *arg,
 402                            Error **errp)
 403 {
 404     if (strcmp(target, "passwd") == 0 || strcmp(target, "password") == 0) {
 405         if (!has_arg) {
 406             error_setg(errp, QERR_MISSING_PARAMETER, "password");
 407         } else {
 408             qmp_change_vnc_password(arg, errp);
 409         }
 410     } else {
 411         qmp_change_vnc_listen(target, errp);
 412     }
 413 }
 414 #else
 415 void qmp_change_vnc_password(const char *password, Error **errp)
 416 {
 417     error_setg(errp, QERR_FEATURE_DISABLED, "vnc");
 418 }
 419 static void qmp_change_vnc(const char *target, bool has_arg, const char *arg,
 420                            Error **errp)
 421 {
 422     error_setg(errp, QERR_FEATURE_DISABLED, "vnc");
 423 }
 424 #endif /* !CONFIG_VNC */
 425
 426 void qmp_change(const char *device, const char *target,
 427                 bool has_arg, const char *arg, Error **errp)
 428 {
 429     if (strcmp(device, "vnc") == 0) {
 430         qmp_change_vnc(target, has_arg, arg, errp);
 431     } else {
 432         qmp_change_blockdev(device, target, arg, errp);
 433     }
 434 }
 435
 436 static void qom_list_types_tramp(ObjectClass *klass, void *data)
 437 {
 438     ObjectTypeInfoList *e, **pret = data;
 439     ObjectTypeInfo *info;
 440
 441     info = g_malloc0(sizeof(*info));
 442     info->name = g_strdup(object_class_get_name(klass));
 443
 444     e = g_malloc0(sizeof(*e));
 445     e->value = info;
 446     e->next = *pret;
 447     *pret = e;
 448 }
 449
 450 ObjectTypeInfoList *qmp_qom_list_types(bool has_implements,
 451                                        const char *implements,
 452                                        bool has_abstract,
 453                                        bool abstract,
 454                                        Error **errp)
 455 {
 456     ObjectTypeInfoList *ret = NULL;
 457
 458     object_class_foreach(qom_list_types_tramp, implements, abstract, &ret);
 459
 460     return ret;
 461 }
 462
 463 /* Return a DevicePropertyInfo for a qdev property.
 464  *
 465  * If a qdev property with the given name does not exist, use the given default
 466  * type.  If the qdev property info should not be shown, return NULL.
 467  *
 468  * The caller must free the return value.
 469  */
 470 static DevicePropertyInfo *make_device_property_info(ObjectClass *klass,
 471                                                      const char *name,
 472                                                      const char *default_type,
 473                                                      const char *description)
 474 {
 475     DevicePropertyInfo *info;
 476     Property *prop;
 477
 478     do {
 479         for (prop = DEVICE_CLASS(klass)->props; prop && prop->name; prop++) {
 480             if (strcmp(name, prop->name) != 0) {
 481                 continue;
 482             }
 483
 484             /*
 485              * TODO Properties without a parser are just for dirty hacks.
 486              * qdev_prop_ptr is the only such PropertyInfo.  It's marked
 487              * for removal.  This conditional should be removed along with
 488              * it.
 489              */
 490             if (!prop->info->set) {
 491                 return NULL;           /* no way to set it, don't show */
 492             }
 493
 494             info = g_malloc0(sizeof(*info));
 495             info->name = g_strdup(prop->name);
 496             info->type = g_strdup(prop->info->name);
 497             info->has_description = !!prop->info->description;
 498             info->description = g_strdup(prop->info->description);
 499             return info;
 500         }
 501         klass = object_class_get_parent(klass);
 502     } while (klass != object_class_by_name(TYPE_DEVICE));
 503
 504     /* Not a qdev property, use the default type */
 505     info = g_malloc0(sizeof(*info));
 506     info->name = g_strdup(name);
 507     info->type = g_strdup(default_type);
 508     info->has_description = !!description;
 509     info->description = g_strdup(description);
 510
 511     return info;
 512 }
 513
 514 DevicePropertyInfoList *qmp_device_list_properties(const char *typename,
 515                                                    Error **errp)
 516 {
 517     ObjectClass *klass;
 518     Object *obj;
 519     ObjectProperty *prop;
 520     DevicePropertyInfoList *prop_list = NULL;
 521
 522     klass = object_class_by_name(typename);
 523     if (klass == NULL) {
 524         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
 525                   "Device '%s' not found", typename);
 526         return NULL;
 527     }
 528
 529     klass = object_class_dynamic_cast(klass, TYPE_DEVICE);
 530     if (klass == NULL) {
 531         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "name", TYPE_DEVICE);
 532         return NULL;
 533     }
 534
 535     obj = object_new(typename);
 536
 537     QTAILQ_FOREACH(prop, &obj->properties, node) {
 538         DevicePropertyInfo *info;
 539         DevicePropertyInfoList *entry;
 540
 541         /* Skip Object and DeviceState properties */
 542         if (strcmp(prop->name, "type") == 0 ||
 543             strcmp(prop->name, "realized") == 0 ||
 544             strcmp(prop->name, "hotpluggable") == 0 ||
 545             strcmp(prop->name, "hotplugged") == 0 ||
 546             strcmp(prop->name, "parent_bus") == 0) {
 547             continue;
 548         }
 549
 550         /* Skip legacy properties since they are just string versions of
 551          * properties that we already list.
 552          */
 553         if (strstart(prop->name, "legacy-", NULL)) {
 554             continue;
 555         }
 556
 557         info = make_device_property_info(klass, prop->name, prop->type,
 558                                          prop->description);
 559         if (!info) {
 560             continue;
 561         }
 562
 563         entry = g_malloc0(sizeof(*entry));
 564         entry->value = info;
 565         entry->next = prop_list;
 566         prop_list = entry;
 567     }
 568
 569     object_unref(obj);
 570
 571     return prop_list;
 572 }
 573
 574 CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
 575 {
 576     return arch_query_cpu_definitions(errp);
 577 }
 578
 579 void qmp_add_client(const char *protocol, const char *fdname,
 580                     bool has_skipauth, bool skipauth, bool has_tls, bool tls,
 581                     Error **errp)
 582 {
 583     CharDriverState *s;
 584     int fd;
 585
 586     fd = monitor_get_fd(cur_mon, fdname, errp);
 587     if (fd < 0) {
 588         return;
 589     }
 590
 591     if (strcmp(protocol, "spice") == 0) {
 592         if (!qemu_using_spice(errp)) {
 593             close(fd);
 594             return;
 595         }
 596         skipauth = has_skipauth ? skipauth : false;
 597         tls = has_tls ? tls : false;
 598         if (qemu_spice_display_add_client(fd, skipauth, tls) < 0) {
 599             error_setg(errp, "spice failed to add client");
 600             close(fd);
 601         }
 602         return;
 603 #ifdef CONFIG_VNC
 604     } else if (strcmp(protocol, "vnc") == 0) {
 605         skipauth = has_skipauth ? skipauth : false;
 606         vnc_display_add_client(NULL, fd, skipauth);
 607         return;
 608 #endif
 609     } else if ((s = qemu_chr_find(protocol)) != NULL) {
 610         if (qemu_chr_add_client(s, fd) < 0) {
 611             error_setg(errp, "failed to add client");
 612             close(fd);
 613             return;
 614         }
 615         return;
 616     }
 617
 618     error_setg(errp, "protocol '%s' is invalid", protocol);
 619     close(fd);
 620 }
 621
 622 void object_add(const char *type, const char *id, const QDict *qdict,
 623                 Visitor *v, Error **errp)
 624 {
 625     Object *obj;
 626     ObjectClass *klass;
 627     const QDictEntry *e;
 628     Error *local_err = NULL;
 629
 630     klass = object_class_by_name(type);
 631     if (!klass) {
 632         error_setg(errp, "invalid object type: %s", type);
 633         return;
 634     }
 635
 636     if (!object_class_dynamic_cast(klass, TYPE_USER_CREATABLE)) {
 637         error_setg(errp, "object type '%s' isn't supported by object-add",
 638                    type);
 639         return;
 640     }
 641
 642     if (object_class_is_abstract(klass)) {
 643         error_setg(errp, "object type '%s' is abstract", type);
 644         return;
 645     }
 646
 647     obj = object_new(type);
 648     if (qdict) {
 649         for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
 650             object_property_set(obj, v, e->key, &local_err);
 651             if (local_err) {
 652                 goto out;
 653             }
 654         }
 655     }
 656
 657     object_property_add_child(object_get_objects_root(),
 658                               id, obj, &local_err);
 659     if (local_err) {
 660         goto out;
 661     }
 662
 663     user_creatable_complete(obj, &local_err);
 664     if (local_err) {
 665         object_property_del(object_get_objects_root(),
 666                             id, &error_abort);
 667         goto out;
 668     }
 669 out:
 670     if (local_err) {
 671         error_propagate(errp, local_err);
 672     }
 673     object_unref(obj);
 674 }
 675
 676 int qmp_object_add(Monitor *mon, const QDict *qdict, QObject **ret)
 677 {
 678     const char *type = qdict_get_str(qdict, "qom-type");
 679     const char *id = qdict_get_str(qdict, "id");
 680     QObject *props = qdict_get(qdict, "props");
 681     const QDict *pdict = NULL;
 682     Error *local_err = NULL;
 683     QmpInputVisitor *qiv;
 684
 685     if (props) {
 686         pdict = qobject_to_qdict(props);
 687         if (!pdict) {
 688             error_setg(&local_err, QERR_INVALID_PARAMETER_TYPE,
 689                        "props", "dict");
 690             goto out;
 691         }
 692     }
 693
 694     qiv = qmp_input_visitor_new(props);
 695     object_add(type, id, pdict, qmp_input_get_visitor(qiv), &local_err);
 696     qmp_input_visitor_cleanup(qiv);
 697
 698 out:
 699     if (local_err) {
 700         qerror_report_err(local_err);
 701         error_free(local_err);
 702         return -1;
 703     }
 704
 705     return 0;
 706 }
 707
 708 void qmp_object_del(const char *id, Error **errp)
 709 {
 710     Object *container;
 711     Object *obj;
 712
 713     container = object_get_objects_root();
 714     obj = object_resolve_path_component(container, id);
 715     if (!obj) {
 716         error_setg(errp, "object id not found");
 717         return;
 718     }
 719
 720     if (!user_creatable_can_be_deleted(USER_CREATABLE(obj), errp)) {
 721         error_setg(errp, "%s is in use, can not be deleted", id);
 722         return;
 723     }
 724     object_unparent(obj);
 725 }
 726
 727 MemoryDeviceInfoList *qmp_query_memory_devices(Error **errp)
 728 {
 729     MemoryDeviceInfoList *head = NULL;
 730     MemoryDeviceInfoList **prev = &head;
 731
 732     qmp_pc_dimm_device_list(qdev_get_machine(), &prev);
 733
 734     return head;
 735 }
 736
 737 ACPIOSTInfoList *qmp_query_acpi_ospm_status(Error **errp)
 738 {
 739     bool ambig;
 740     ACPIOSTInfoList *head = NULL;
 741     ACPIOSTInfoList **prev = &head;
 742     Object *obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, &ambig);
 743
 744     if (obj) {
 745         AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(obj);
 746         AcpiDeviceIf *adev = ACPI_DEVICE_IF(obj);
 747
 748         adevc->ospm_status(adev, &prev);
 749     } else {
 750         error_setg(errp, "command is not supported, missing ACPI device");
 751     }
 752
 753     return head;
 754 }