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_malloc0(sizeof(*info));
  49     const char *version = QEMU_VERSION;
  50     char *tmp;
  51
  52     info->qemu.major = strtol(version, &tmp, 10);
  53     tmp++;
  54     info->qemu.minor = strtol(tmp, &tmp, 10);
  55     tmp++;
  56     info->qemu.micro = strtol(tmp, &tmp, 10);
  57     info->package = g_strdup(QEMU_PKGVERSION);
  58
  59     return info;
  60 }
  61
  62 KvmInfo *qmp_query_kvm(Error **errp)
  63 {
  64     KvmInfo *info = g_malloc0(sizeof(*info));
  65
  66     info->enabled = kvm_enabled();
  67     info->present = kvm_available();
  68
  69     return info;
  70 }
  71
  72 UuidInfo *qmp_query_uuid(Error **errp)
  73 {
  74     UuidInfo *info = g_malloc0(sizeof(*info));
  75     char uuid[64];
  76
  77     snprintf(uuid, sizeof(uuid), UUID_FMT, qemu_uuid[0], qemu_uuid[1],
  78                    qemu_uuid[2], qemu_uuid[3], qemu_uuid[4], qemu_uuid[5],
  79                    qemu_uuid[6], qemu_uuid[7], qemu_uuid[8], qemu_uuid[9],
  80                    qemu_uuid[10], qemu_uuid[11], qemu_uuid[12], qemu_uuid[13],
  81                    qemu_uuid[14], qemu_uuid[15]);
  82
  83     info->UUID = g_strdup(uuid);
  84     return info;
  85 }
  86
  87 void qmp_quit(Error **errp)
  88 {
  89     no_shutdown = 0;
  90     qemu_system_shutdown_request();
  91 }
  92
  93 void qmp_stop(Error **errp)
  94 {
  95     if (runstate_check(RUN_STATE_INMIGRATE)) {
  96         autostart = 0;
  97     } else {
  98         vm_stop(RUN_STATE_PAUSED);
  99     }
 100 }
 101
 102 void qmp_system_reset(Error **errp)
 103 {
 104     qemu_system_reset_request();
 105 }
 106
 107 void qmp_system_powerdown(Error **erp)
 108 {
 109     qemu_system_powerdown_request();
 110 }
 111
 112 void qmp_cpu(int64_t index, Error **errp)
 113 {
 114     /* Just do nothing */
 115 }
 116
 117 void qmp_cpu_add(int64_t id, Error **errp)
 118 {
 119     MachineClass *mc;
 120
 121     mc = MACHINE_GET_CLASS(current_machine);
 122     if (mc->hot_add_cpu) {
 123         mc->hot_add_cpu(id, errp);
 124     } else {
 125         error_setg(errp, "Not supported");
 126     }
 127 }
 128
 129 #ifndef CONFIG_VNC
 130 /* If VNC support is enabled, the "true" query-vnc command is
 131    defined in the VNC subsystem */
 132 VncInfo *qmp_query_vnc(Error **errp)
 133 {
 134     error_set(errp, QERR_FEATURE_DISABLED, "vnc");
 135     return NULL;
 136 };
 137
 138 VncInfo2List *qmp_query_vnc_servers(Error **errp)
 139 {
 140     error_set(errp, QERR_FEATURE_DISABLED, "vnc");
 141     return NULL;
 142 };
 143 #endif
 144
 145 #ifndef CONFIG_SPICE
 146 /*
 147  * qmp-commands.hx ensures that QMP command query-spice exists only
 148  * #ifdef CONFIG_SPICE.  Necessary for an accurate query-commands
 149  * result.  However, the QAPI schema is blissfully unaware of that,
 150  * and the QAPI code generator happily generates a dead
 151  * qmp_marshal_input_query_spice() that calls qmp_query_spice().
 152  * Provide it one, or else linking fails.
 153  * FIXME Educate the QAPI schema on CONFIG_SPICE.
 154  */
 155 SpiceInfo *qmp_query_spice(Error **errp)
 156 {
 157     abort();
 158 };
 159 #endif
 160
 161 void qmp_cont(Error **errp)
 162 {
 163     Error *local_err = NULL;
 164     BlockDriverState *bs;
 165
 166     if (runstate_needs_reset()) {
 167         error_setg(errp, "Resetting the Virtual Machine is required");
 168         return;
 169     } else if (runstate_check(RUN_STATE_SUSPENDED)) {
 170         return;
 171     }
 172
 173     for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
 174         bdrv_iostatus_reset(bs);
 175     }
 176     for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
 177         bdrv_add_key(bs, NULL, &local_err);
 178         if (local_err) {
 179             error_propagate(errp, local_err);
 180             return;
 181         }
 182     }
 183
 184     if (runstate_check(RUN_STATE_INMIGRATE)) {
 185         autostart = 1;
 186     } else {
 187         vm_start();
 188     }
 189 }
 190
 191 void qmp_system_wakeup(Error **errp)
 192 {
 193     qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
 194 }
 195
 196 ObjectPropertyInfoList *qmp_qom_list(const char *path, Error **errp)
 197 {
 198     Object *obj;
 199     bool ambiguous = false;
 200     ObjectPropertyInfoList *props = NULL;
 201     ObjectProperty *prop;
 202
 203     obj = object_resolve_path(path, &ambiguous);
 204     if (obj == NULL) {
 205         if (ambiguous) {
 206             error_setg(errp, "Path '%s' is ambiguous", path);
 207         } else {
 208             error_set(errp, QERR_DEVICE_NOT_FOUND, path);
 209         }
 210         return NULL;
 211     }
 212
 213     QTAILQ_FOREACH(prop, &obj->properties, node) {
 214         ObjectPropertyInfoList *entry = g_malloc0(sizeof(*entry));
 215
 216         entry->value = g_malloc0(sizeof(ObjectPropertyInfo));
 217         entry->next = props;
 218         props = entry;
 219
 220         entry->value->name = g_strdup(prop->name);
 221         entry->value->type = g_strdup(prop->type);
 222     }
 223
 224     return props;
 225 }
 226
 227 /* FIXME: teach qapi about how to pass through Visitors */
 228 int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret)
 229 {
 230     const char *path = qdict_get_str(qdict, "path");
 231     const char *property = qdict_get_str(qdict, "property");
 232     QObject *value = qdict_get(qdict, "value");
 233     Error *local_err = NULL;
 234     Object *obj;
 235
 236     obj = object_resolve_path(path, NULL);
 237     if (!obj) {
 238         error_set(&local_err, QERR_DEVICE_NOT_FOUND, path);
 239         goto out;
 240     }
 241
 242     object_property_set_qobject(obj, value, property, &local_err);
 243
 244 out:
 245     if (local_err) {
 246         qerror_report_err(local_err);
 247         error_free(local_err);
 248         return -1;
 249     }
 250
 251     return 0;
 252 }
 253
 254 int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret)
 255 {
 256     const char *path = qdict_get_str(qdict, "path");
 257     const char *property = qdict_get_str(qdict, "property");
 258     Error *local_err = NULL;
 259     Object *obj;
 260
 261     obj = object_resolve_path(path, NULL);
 262     if (!obj) {
 263         error_set(&local_err, QERR_DEVICE_NOT_FOUND, path);
 264         goto out;
 265     }
 266
 267     *ret = object_property_get_qobject(obj, property, &local_err);
 268
 269 out:
 270     if (local_err) {
 271         qerror_report_err(local_err);
 272         error_free(local_err);
 273         return -1;
 274     }
 275
 276     return 0;
 277 }
 278
 279 void qmp_set_password(const char *protocol, const char *password,
 280                       bool has_connected, const char *connected, Error **errp)
 281 {
 282     int disconnect_if_connected = 0;
 283     int fail_if_connected = 0;
 284     int rc;
 285
 286     if (has_connected) {
 287         if (strcmp(connected, "fail") == 0) {
 288             fail_if_connected = 1;
 289         } else if (strcmp(connected, "disconnect") == 0) {
 290             disconnect_if_connected = 1;
 291         } else if (strcmp(connected, "keep") == 0) {
 292             /* nothing */
 293         } else {
 294             error_set(errp, QERR_INVALID_PARAMETER, "connected");
 295             return;
 296         }
 297     }
 298
 299     if (strcmp(protocol, "spice") == 0) {
 300         if (!qemu_using_spice(errp)) {
 301             return;
 302         }
 303         rc = qemu_spice_set_passwd(password, fail_if_connected,
 304                                    disconnect_if_connected);
 305         if (rc != 0) {
 306             error_set(errp, QERR_SET_PASSWD_FAILED);
 307         }
 308         return;
 309     }
 310
 311     if (strcmp(protocol, "vnc") == 0) {
 312         if (fail_if_connected || disconnect_if_connected) {
 313             /* vnc supports "connected=keep" only */
 314             error_set(errp, QERR_INVALID_PARAMETER, "connected");
 315             return;
 316         }
 317         /* Note that setting an empty password will not disable login through
 318          * this interface. */
 319         rc = vnc_display_password(NULL, password);
 320         if (rc < 0) {
 321             error_set(errp, QERR_SET_PASSWD_FAILED);
 322         }
 323         return;
 324     }
 325
 326     error_set(errp, QERR_INVALID_PARAMETER, "protocol");
 327 }
 328
 329 void qmp_expire_password(const char *protocol, const char *whenstr,
 330                          Error **errp)
 331 {
 332     time_t when;
 333     int rc;
 334
 335     if (strcmp(whenstr, "now") == 0) {
 336         when = 0;
 337     } else if (strcmp(whenstr, "never") == 0) {
 338         when = TIME_MAX;
 339     } else if (whenstr[0] == '+') {
 340         when = time(NULL) + strtoull(whenstr+1, NULL, 10);
 341     } else {
 342         when = strtoull(whenstr, NULL, 10);
 343     }
 344
 345     if (strcmp(protocol, "spice") == 0) {
 346         if (!qemu_using_spice(errp)) {
 347             return;
 348         }
 349         rc = qemu_spice_set_pw_expire(when);
 350         if (rc != 0) {
 351             error_set(errp, QERR_SET_PASSWD_FAILED);
 352         }
 353         return;
 354     }
 355
 356     if (strcmp(protocol, "vnc") == 0) {
 357         rc = vnc_display_pw_expire(NULL, when);
 358         if (rc != 0) {
 359             error_set(errp, QERR_SET_PASSWD_FAILED);
 360         }
 361         return;
 362     }
 363
 364     error_set(errp, QERR_INVALID_PARAMETER, "protocol");
 365 }
 366
 367 #ifdef CONFIG_VNC
 368 void qmp_change_vnc_password(const char *password, Error **errp)
 369 {
 370     if (vnc_display_password(NULL, password) < 0) {
 371         error_set(errp, QERR_SET_PASSWD_FAILED);
 372     }
 373 }
 374
 375 static void qmp_change_vnc_listen(const char *target, Error **errp)
 376 {
 377     QemuOptsList *olist = qemu_find_opts("vnc");
 378     QemuOpts *opts;
 379
 380     if (strstr(target, "id=")) {
 381         error_setg(errp, "id not supported");
 382         return;
 383     }
 384
 385     opts = qemu_opts_find(olist, "default");
 386     if (opts) {
 387         qemu_opts_del(opts);
 388     }
 389     opts = vnc_parse_func(target);
 390     if (!opts) {
 391         return;
 392     }
 393
 394     vnc_display_open("default", errp);
 395 }
 396
 397 static void qmp_change_vnc(const char *target, bool has_arg, const char *arg,
 398                            Error **errp)
 399 {
 400     if (strcmp(target, "passwd") == 0 || strcmp(target, "password") == 0) {
 401         if (!has_arg) {
 402             error_set(errp, QERR_MISSING_PARAMETER, "password");
 403         } else {
 404             qmp_change_vnc_password(arg, errp);
 405         }
 406     } else {
 407         qmp_change_vnc_listen(target, errp);
 408     }
 409 }
 410 #else
 411 void qmp_change_vnc_password(const char *password, Error **errp)
 412 {
 413     error_set(errp, QERR_FEATURE_DISABLED, "vnc");
 414 }
 415 static void qmp_change_vnc(const char *target, bool has_arg, const char *arg,
 416                            Error **errp)
 417 {
 418     error_set(errp, QERR_FEATURE_DISABLED, "vnc");
 419 }
 420 #endif /* !CONFIG_VNC */
 421
 422 void qmp_change(const char *device, const char *target,
 423                 bool has_arg, const char *arg, Error **errp)
 424 {
 425     if (strcmp(device, "vnc") == 0) {
 426         qmp_change_vnc(target, has_arg, arg, errp);
 427     } else {
 428         qmp_change_blockdev(device, target, arg, errp);
 429     }
 430 }
 431
 432 static void qom_list_types_tramp(ObjectClass *klass, void *data)
 433 {
 434     ObjectTypeInfoList *e, **pret = data;
 435     ObjectTypeInfo *info;
 436
 437     info = g_malloc0(sizeof(*info));
 438     info->name = g_strdup(object_class_get_name(klass));
 439
 440     e = g_malloc0(sizeof(*e));
 441     e->value = info;
 442     e->next = *pret;
 443     *pret = e;
 444 }
 445
 446 ObjectTypeInfoList *qmp_qom_list_types(bool has_implements,
 447                                        const char *implements,
 448                                        bool has_abstract,
 449                                        bool abstract,
 450                                        Error **errp)
 451 {
 452     ObjectTypeInfoList *ret = NULL;
 453
 454     object_class_foreach(qom_list_types_tramp, implements, abstract, &ret);
 455
 456     return ret;
 457 }
 458
 459 /* Return a DevicePropertyInfo for a qdev property.
 460  *
 461  * If a qdev property with the given name does not exist, use the given default
 462  * type.  If the qdev property info should not be shown, return NULL.
 463  *
 464  * The caller must free the return value.
 465  */
 466 static DevicePropertyInfo *make_device_property_info(ObjectClass *klass,
 467                                                      const char *name,
 468                                                      const char *default_type,
 469                                                      const char *description)
 470 {
 471     DevicePropertyInfo *info;
 472     Property *prop;
 473
 474     do {
 475         for (prop = DEVICE_CLASS(klass)->props; prop && prop->name; prop++) {
 476             if (strcmp(name, prop->name) != 0) {
 477                 continue;
 478             }
 479
 480             /*
 481              * TODO Properties without a parser are just for dirty hacks.
 482              * qdev_prop_ptr is the only such PropertyInfo.  It's marked
 483              * for removal.  This conditional should be removed along with
 484              * it.
 485              */
 486             if (!prop->info->set) {
 487                 return NULL;           /* no way to set it, don't show */
 488             }
 489
 490             info = g_malloc0(sizeof(*info));
 491             info->name = g_strdup(prop->name);
 492             info->type = g_strdup(prop->info->name);
 493             info->has_description = !!prop->info->description;
 494             info->description = g_strdup(prop->info->description);
 495             return info;
 496         }
 497         klass = object_class_get_parent(klass);
 498     } while (klass != object_class_by_name(TYPE_DEVICE));
 499
 500     /* Not a qdev property, use the default type */
 501     info = g_malloc0(sizeof(*info));
 502     info->name = g_strdup(name);
 503     info->type = g_strdup(default_type);
 504     info->has_description = !!description;
 505     info->description = g_strdup(description);
 506
 507     return info;
 508 }
 509
 510 DevicePropertyInfoList *qmp_device_list_properties(const char *typename,
 511                                                    Error **errp)
 512 {
 513     ObjectClass *klass;
 514     Object *obj;
 515     ObjectProperty *prop;
 516     DevicePropertyInfoList *prop_list = NULL;
 517
 518     klass = object_class_by_name(typename);
 519     if (klass == NULL) {
 520         error_set(errp, QERR_DEVICE_NOT_FOUND, typename);
 521         return NULL;
 522     }
 523
 524     klass = object_class_dynamic_cast(klass, TYPE_DEVICE);
 525     if (klass == NULL) {
 526         error_set(errp, QERR_INVALID_PARAMETER_VALUE,
 527                   "name", TYPE_DEVICE);
 528         return NULL;
 529     }
 530
 531     obj = object_new(typename);
 532
 533     QTAILQ_FOREACH(prop, &obj->properties, node) {
 534         DevicePropertyInfo *info;
 535         DevicePropertyInfoList *entry;
 536
 537         /* Skip Object and DeviceState properties */
 538         if (strcmp(prop->name, "type") == 0 ||
 539             strcmp(prop->name, "realized") == 0 ||
 540             strcmp(prop->name, "hotpluggable") == 0 ||
 541             strcmp(prop->name, "hotplugged") == 0 ||
 542             strcmp(prop->name, "parent_bus") == 0) {
 543             continue;
 544         }
 545
 546         /* Skip legacy properties since they are just string versions of
 547          * properties that we already list.
 548          */
 549         if (strstart(prop->name, "legacy-", NULL)) {
 550             continue;
 551         }
 552
 553         info = make_device_property_info(klass, prop->name, prop->type,
 554                                          prop->description);
 555         if (!info) {
 556             continue;
 557         }
 558
 559         entry = g_malloc0(sizeof(*entry));
 560         entry->value = info;
 561         entry->next = prop_list;
 562         prop_list = entry;
 563     }
 564
 565     object_unref(obj);
 566
 567     return prop_list;
 568 }
 569
 570 CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
 571 {
 572     return arch_query_cpu_definitions(errp);
 573 }
 574
 575 void qmp_add_client(const char *protocol, const char *fdname,
 576                     bool has_skipauth, bool skipauth, bool has_tls, bool tls,
 577                     Error **errp)
 578 {
 579     CharDriverState *s;
 580     int fd;
 581
 582     fd = monitor_get_fd(cur_mon, fdname, errp);
 583     if (fd < 0) {
 584         return;
 585     }
 586
 587     if (strcmp(protocol, "spice") == 0) {
 588         if (!qemu_using_spice(errp)) {
 589             close(fd);
 590             return;
 591         }
 592         skipauth = has_skipauth ? skipauth : false;
 593         tls = has_tls ? tls : false;
 594         if (qemu_spice_display_add_client(fd, skipauth, tls) < 0) {
 595             error_setg(errp, "spice failed to add client");
 596             close(fd);
 597         }
 598         return;
 599 #ifdef CONFIG_VNC
 600     } else if (strcmp(protocol, "vnc") == 0) {
 601         skipauth = has_skipauth ? skipauth : false;
 602         vnc_display_add_client(NULL, fd, skipauth);
 603         return;
 604 #endif
 605     } else if ((s = qemu_chr_find(protocol)) != NULL) {
 606         if (qemu_chr_add_client(s, fd) < 0) {
 607             error_setg(errp, "failed to add client");
 608             close(fd);
 609             return;
 610         }
 611         return;
 612     }
 613
 614     error_setg(errp, "protocol '%s' is invalid", protocol);
 615     close(fd);
 616 }
 617
 618 void object_add(const char *type, const char *id, const QDict *qdict,
 619                 Visitor *v, Error **errp)
 620 {
 621     Object *obj;
 622     ObjectClass *klass;
 623     const QDictEntry *e;
 624     Error *local_err = NULL;
 625
 626     klass = object_class_by_name(type);
 627     if (!klass) {
 628         error_setg(errp, "invalid object type: %s", type);
 629         return;
 630     }
 631
 632     if (!object_class_dynamic_cast(klass, TYPE_USER_CREATABLE)) {
 633         error_setg(errp, "object type '%s' isn't supported by object-add",
 634                    type);
 635         return;
 636     }
 637
 638     if (object_class_is_abstract(klass)) {
 639         error_setg(errp, "object type '%s' is abstract", type);
 640         return;
 641     }
 642
 643     obj = object_new(type);
 644     if (qdict) {
 645         for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
 646             object_property_set(obj, v, e->key, &local_err);
 647             if (local_err) {
 648                 goto out;
 649             }
 650         }
 651     }
 652
 653     object_property_add_child(container_get(object_get_root(), "/objects"),
 654                               id, obj, &local_err);
 655     if (local_err) {
 656         goto out;
 657     }
 658
 659     user_creatable_complete(obj, &local_err);
 660     if (local_err) {
 661         object_property_del(container_get(object_get_root(), "/objects"),
 662                             id, &error_abort);
 663         goto out;
 664     }
 665 out:
 666     if (local_err) {
 667         error_propagate(errp, local_err);
 668     }
 669     object_unref(obj);
 670 }
 671
 672 int qmp_object_add(Monitor *mon, const QDict *qdict, QObject **ret)
 673 {
 674     const char *type = qdict_get_str(qdict, "qom-type");
 675     const char *id = qdict_get_str(qdict, "id");
 676     QObject *props = qdict_get(qdict, "props");
 677     const QDict *pdict = NULL;
 678     Error *local_err = NULL;
 679     QmpInputVisitor *qiv;
 680
 681     if (props) {
 682         pdict = qobject_to_qdict(props);
 683         if (!pdict) {
 684             error_set(&local_err, QERR_INVALID_PARAMETER_TYPE, "props", "dict");
 685             goto out;
 686         }
 687     }
 688
 689     qiv = qmp_input_visitor_new(props);
 690     object_add(type, id, pdict, qmp_input_get_visitor(qiv), &local_err);
 691     qmp_input_visitor_cleanup(qiv);
 692
 693 out:
 694     if (local_err) {
 695         qerror_report_err(local_err);
 696         error_free(local_err);
 697         return -1;
 698     }
 699
 700     return 0;
 701 }
 702
 703 void qmp_object_del(const char *id, Error **errp)
 704 {
 705     Object *container;
 706     Object *obj;
 707
 708     container = container_get(object_get_root(), "/objects");
 709     obj = object_resolve_path_component(container, id);
 710     if (!obj) {
 711         error_setg(errp, "object id not found");
 712         return;
 713     }
 714     object_unparent(obj);
 715 }
 716
 717 MemoryDeviceInfoList *qmp_query_memory_devices(Error **errp)
 718 {
 719     MemoryDeviceInfoList *head = NULL;
 720     MemoryDeviceInfoList **prev = &head;
 721
 722     qmp_pc_dimm_device_list(qdev_get_machine(), &prev);
 723
 724     return head;
 725 }
 726
 727 ACPIOSTInfoList *qmp_query_acpi_ospm_status(Error **errp)
 728 {
 729     bool ambig;
 730     ACPIOSTInfoList *head = NULL;
 731     ACPIOSTInfoList **prev = &head;
 732     Object *obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, &ambig);
 733
 734     if (obj) {
 735         AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(obj);
 736         AcpiDeviceIf *adev = ACPI_DEVICE_IF(obj);
 737
 738         adevc->ospm_status(adev, &prev);
 739     } else {
 740         error_setg(errp, "command is not supported, missing ACPI device");
 741     }
 742
 743     return head;
 744 }