qdev-monitor.c

   1 /*
   2  *  Dynamic device configuration and creation.
   3  *
   4  *  Copyright (c) 2009 CodeSourcery
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "hw/qdev.h"
  21 #include "hw/sysbus.h"
  22 #include "monitor/monitor.h"
  23 #include "monitor/qdev.h"
  24 #include "qmp-commands.h"
  25 #include "sysemu/arch_init.h"
  26 #include "qemu/config-file.h"
  27
  28 /*
  29  * Aliases were a bad idea from the start.  Let's keep them
  30  * from spreading further.
  31  */
  32 typedef struct QDevAlias
  33 {
  34     const char *typename;
  35     const char *alias;
  36     uint32_t arch_mask;
  37 } QDevAlias;
  38
  39 static const QDevAlias qdev_alias_table[] = {
  40     { "virtio-blk-pci", "virtio-blk", QEMU_ARCH_ALL & ~QEMU_ARCH_S390X },
  41     { "virtio-net-pci", "virtio-net", QEMU_ARCH_ALL & ~QEMU_ARCH_S390X },
  42     { "virtio-serial-pci", "virtio-serial", QEMU_ARCH_ALL & ~QEMU_ARCH_S390X },
  43     { "virtio-balloon-pci", "virtio-balloon",
  44             QEMU_ARCH_ALL & ~QEMU_ARCH_S390X },
  45     { "virtio-blk-s390", "virtio-blk", QEMU_ARCH_S390X },
  46     { "virtio-net-s390", "virtio-net", QEMU_ARCH_S390X },
  47     { "virtio-serial-s390", "virtio-serial", QEMU_ARCH_S390X },
  48     { "lsi53c895a", "lsi" },
  49     { "ich9-ahci", "ahci" },
  50     { "kvm-pci-assign", "pci-assign" },
  51     { }
  52 };
  53
  54 static const char *qdev_class_get_alias(DeviceClass *dc)
  55 {
  56     const char *typename = object_class_get_name(OBJECT_CLASS(dc));
  57     int i;
  58
  59     for (i = 0; qdev_alias_table[i].typename; i++) {
  60         if (qdev_alias_table[i].arch_mask &&
  61             !(qdev_alias_table[i].arch_mask & arch_type)) {
  62             continue;
  63         }
  64
  65         if (strcmp(qdev_alias_table[i].typename, typename) == 0) {
  66             return qdev_alias_table[i].alias;
  67         }
  68     }
  69
  70     return NULL;
  71 }
  72
  73 static bool qdev_class_has_alias(DeviceClass *dc)
  74 {
  75     return (qdev_class_get_alias(dc) != NULL);
  76 }
  77
  78 static void qdev_print_devinfo(DeviceClass *dc)
  79 {
  80     error_printf("name \"%s\"", object_class_get_name(OBJECT_CLASS(dc)));
  81     if (dc->bus_type) {
  82         error_printf(", bus %s", dc->bus_type);
  83     }
  84     if (qdev_class_has_alias(dc)) {
  85         error_printf(", alias \"%s\"", qdev_class_get_alias(dc));
  86     }
  87     if (dc->desc) {
  88         error_printf(", desc \"%s\"", dc->desc);
  89     }
  90     if (dc->no_user) {
  91         error_printf(", no-user");
  92     }
  93     error_printf("\n");
  94 }
  95
  96 static gint devinfo_cmp(gconstpointer a, gconstpointer b)
  97 {
  98     return strcasecmp(object_class_get_name((ObjectClass *)a),
  99                       object_class_get_name((ObjectClass *)b));
 100 }
 101
 102 static void qdev_print_devinfos(bool show_no_user)
 103 {
 104     static const char *cat_name[DEVICE_CATEGORY_MAX + 1] = {
 105         [DEVICE_CATEGORY_BRIDGE]  = "Controller/Bridge/Hub",
 106         [DEVICE_CATEGORY_USB]     = "USB",
 107         [DEVICE_CATEGORY_STORAGE] = "Storage",
 108         [DEVICE_CATEGORY_NETWORK] = "Network",
 109         [DEVICE_CATEGORY_INPUT]   = "Input",
 110         [DEVICE_CATEGORY_DISPLAY] = "Display",
 111         [DEVICE_CATEGORY_SOUND]   = "Sound",
 112         [DEVICE_CATEGORY_MISC]    = "Misc",
 113         [DEVICE_CATEGORY_MAX]     = "Uncategorized",
 114     };
 115     GSList *list, *elt;
 116     int i;
 117     bool cat_printed;
 118
 119     list = g_slist_sort(object_class_get_list(TYPE_DEVICE, false),
 120                         devinfo_cmp);
 121
 122     for (i = 0; i <= DEVICE_CATEGORY_MAX; i++) {
 123         cat_printed = false;
 124         for (elt = list; elt; elt = elt->next) {
 125             DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data,
 126                                                  TYPE_DEVICE);
 127             if ((i < DEVICE_CATEGORY_MAX
 128                  ? !test_bit(i, dc->categories)
 129                  : !bitmap_empty(dc->categories, DEVICE_CATEGORY_MAX))
 130                 || (!show_no_user && dc->no_user)) {
 131                 continue;
 132             }
 133             if (!cat_printed) {
 134                 error_printf("%s%s devices:\n", i ? "\n" : "",
 135                              cat_name[i]);
 136                 cat_printed = true;
 137             }
 138             qdev_print_devinfo(dc);
 139         }
 140     }
 141
 142     g_slist_free(list);
 143 }
 144
 145 static int set_property(const char *name, const char *value, void *opaque)
 146 {
 147     DeviceState *dev = opaque;
 148     Error *err = NULL;
 149
 150     if (strcmp(name, "driver") == 0)
 151         return 0;
 152     if (strcmp(name, "bus") == 0)
 153         return 0;
 154
 155     qdev_prop_parse(dev, name, value, &err);
 156     if (err != NULL) {
 157         qerror_report_err(err);
 158         error_free(err);
 159         return -1;
 160     }
 161     return 0;
 162 }
 163
 164 static const char *find_typename_by_alias(const char *alias)
 165 {
 166     int i;
 167
 168     for (i = 0; qdev_alias_table[i].alias; i++) {
 169         if (qdev_alias_table[i].arch_mask &&
 170             !(qdev_alias_table[i].arch_mask & arch_type)) {
 171             continue;
 172         }
 173
 174         if (strcmp(qdev_alias_table[i].alias, alias) == 0) {
 175             return qdev_alias_table[i].typename;
 176         }
 177     }
 178
 179     return NULL;
 180 }
 181
 182 int qdev_device_help(QemuOpts *opts)
 183 {
 184     const char *driver;
 185     Property *prop;
 186     ObjectClass *klass;
 187
 188     driver = qemu_opt_get(opts, "driver");
 189     if (driver && is_help_option(driver)) {
 190         qdev_print_devinfos(false);
 191         return 1;
 192     }
 193
 194     if (!driver || !qemu_opt_has_help_opt(opts)) {
 195         return 0;
 196     }
 197
 198     klass = object_class_by_name(driver);
 199     if (!klass) {
 200         const char *typename = find_typename_by_alias(driver);
 201
 202         if (typename) {
 203             driver = typename;
 204             klass = object_class_by_name(driver);
 205         }
 206     }
 207
 208     if (!klass) {
 209         return 0;
 210     }
 211     do {
 212         for (prop = DEVICE_CLASS(klass)->props; prop && prop->name; prop++) {
 213             /*
 214              * TODO Properties without a parser are just for dirty hacks.
 215              * qdev_prop_ptr is the only such PropertyInfo.  It's marked
 216              * for removal.  This conditional should be removed along with
 217              * it.
 218              */
 219             if (!prop->info->set) {
 220                 continue;           /* no way to set it, don't show */
 221             }
 222             error_printf("%s.%s=%s\n", driver, prop->name,
 223                          prop->info->legacy_name ?: prop->info->name);
 224         }
 225         klass = object_class_get_parent(klass);
 226     } while (klass != object_class_by_name(TYPE_DEVICE));
 227     return 1;
 228 }
 229
 230 static Object *qdev_get_peripheral(void)
 231 {
 232     static Object *dev;
 233
 234     if (dev == NULL) {
 235         dev = container_get(qdev_get_machine(), "/peripheral");
 236     }
 237
 238     return dev;
 239 }
 240
 241 static Object *qdev_get_peripheral_anon(void)
 242 {
 243     static Object *dev;
 244
 245     if (dev == NULL) {
 246         dev = container_get(qdev_get_machine(), "/peripheral-anon");
 247     }
 248
 249     return dev;
 250 }
 251
 252 static void qbus_list_bus(DeviceState *dev)
 253 {
 254     BusState *child;
 255     const char *sep = " ";
 256
 257     error_printf("child busses at \"%s\":",
 258                  dev->id ? dev->id : object_get_typename(OBJECT(dev)));
 259     QLIST_FOREACH(child, &dev->child_bus, sibling) {
 260         error_printf("%s\"%s\"", sep, child->name);
 261         sep = ", ";
 262     }
 263     error_printf("\n");
 264 }
 265
 266 static void qbus_list_dev(BusState *bus)
 267 {
 268     BusChild *kid;
 269     const char *sep = " ";
 270
 271     error_printf("devices at \"%s\":", bus->name);
 272     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 273         DeviceState *dev = kid->child;
 274         error_printf("%s\"%s\"", sep, object_get_typename(OBJECT(dev)));
 275         if (dev->id)
 276             error_printf("/\"%s\"", dev->id);
 277         sep = ", ";
 278     }
 279     error_printf("\n");
 280 }
 281
 282 static BusState *qbus_find_bus(DeviceState *dev, char *elem)
 283 {
 284     BusState *child;
 285
 286     QLIST_FOREACH(child, &dev->child_bus, sibling) {
 287         if (strcmp(child->name, elem) == 0) {
 288             return child;
 289         }
 290     }
 291     return NULL;
 292 }
 293
 294 static DeviceState *qbus_find_dev(BusState *bus, char *elem)
 295 {
 296     BusChild *kid;
 297
 298     /*
 299      * try to match in order:
 300      *   (1) instance id, if present
 301      *   (2) driver name
 302      *   (3) driver alias, if present
 303      */
 304     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 305         DeviceState *dev = kid->child;
 306         if (dev->id  &&  strcmp(dev->id, elem) == 0) {
 307             return dev;
 308         }
 309     }
 310     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 311         DeviceState *dev = kid->child;
 312         if (strcmp(object_get_typename(OBJECT(dev)), elem) == 0) {
 313             return dev;
 314         }
 315     }
 316     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 317         DeviceState *dev = kid->child;
 318         DeviceClass *dc = DEVICE_GET_CLASS(dev);
 319
 320         if (qdev_class_has_alias(dc) &&
 321             strcmp(qdev_class_get_alias(dc), elem) == 0) {
 322             return dev;
 323         }
 324     }
 325     return NULL;
 326 }
 327
 328 static BusState *qbus_find_recursive(BusState *bus, const char *name,
 329                                      const char *bus_typename)
 330 {
 331     BusClass *bus_class = BUS_GET_CLASS(bus);
 332     BusChild *kid;
 333     BusState *child, *ret;
 334     int match = 1;
 335
 336     if (name && (strcmp(bus->name, name) != 0)) {
 337         match = 0;
 338     } else if (bus_typename && !object_dynamic_cast(OBJECT(bus), bus_typename)) {
 339         match = 0;
 340     } else if ((bus_class->max_dev != 0) && (bus_class->max_dev <= bus->max_index)) {
 341         if (name != NULL) {
 342             /* bus was explicitly specified: return an error. */
 343             qerror_report(ERROR_CLASS_GENERIC_ERROR, "Bus '%s' is full",
 344                           bus->name);
 345             return NULL;
 346         } else {
 347             /* bus was not specified: try to find another one. */
 348             match = 0;
 349         }
 350     }
 351     if (match) {
 352         return bus;
 353     }
 354
 355     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 356         DeviceState *dev = kid->child;
 357         QLIST_FOREACH(child, &dev->child_bus, sibling) {
 358             ret = qbus_find_recursive(child, name, bus_typename);
 359             if (ret) {
 360                 return ret;
 361             }
 362         }
 363     }
 364     return NULL;
 365 }
 366
 367 static BusState *qbus_find(const char *path)
 368 {
 369     DeviceState *dev;
 370     BusState *bus;
 371     char elem[128];
 372     int pos, len;
 373
 374     /* find start element */
 375     if (path[0] == '/') {
 376         bus = sysbus_get_default();
 377         pos = 0;
 378     } else {
 379         if (sscanf(path, "%127[^/]%n", elem, &len) != 1) {
 380             assert(!path[0]);
 381             elem[0] = len = 0;
 382         }
 383         bus = qbus_find_recursive(sysbus_get_default(), elem, NULL);
 384         if (!bus) {
 385             qerror_report(QERR_BUS_NOT_FOUND, elem);
 386             return NULL;
 387         }
 388         pos = len;
 389     }
 390
 391     for (;;) {
 392         assert(path[pos] == '/' || !path[pos]);
 393         while (path[pos] == '/') {
 394             pos++;
 395         }
 396         if (path[pos] == '\0') {
 397             return bus;
 398         }
 399
 400         /* find device */
 401         if (sscanf(path+pos, "%127[^/]%n", elem, &len) != 1) {
 402             g_assert_not_reached();
 403             elem[0] = len = 0;
 404         }
 405         pos += len;
 406         dev = qbus_find_dev(bus, elem);
 407         if (!dev) {
 408             qerror_report(QERR_DEVICE_NOT_FOUND, elem);
 409             if (!monitor_cur_is_qmp()) {
 410                 qbus_list_dev(bus);
 411             }
 412             return NULL;
 413         }
 414
 415         assert(path[pos] == '/' || !path[pos]);
 416         while (path[pos] == '/') {
 417             pos++;
 418         }
 419         if (path[pos] == '\0') {
 420             /* last specified element is a device.  If it has exactly
 421              * one child bus accept it nevertheless */
 422             switch (dev->num_child_bus) {
 423             case 0:
 424                 qerror_report(QERR_DEVICE_NO_BUS, elem);
 425                 return NULL;
 426             case 1:
 427                 return QLIST_FIRST(&dev->child_bus);
 428             default:
 429                 qerror_report(QERR_DEVICE_MULTIPLE_BUSSES, elem);
 430                 if (!monitor_cur_is_qmp()) {
 431                     qbus_list_bus(dev);
 432                 }
 433                 return NULL;
 434             }
 435         }
 436
 437         /* find bus */
 438         if (sscanf(path+pos, "%127[^/]%n", elem, &len) != 1) {
 439             g_assert_not_reached();
 440             elem[0] = len = 0;
 441         }
 442         pos += len;
 443         bus = qbus_find_bus(dev, elem);
 444         if (!bus) {
 445             qerror_report(QERR_BUS_NOT_FOUND, elem);
 446             if (!monitor_cur_is_qmp()) {
 447                 qbus_list_bus(dev);
 448             }
 449             return NULL;
 450         }
 451     }
 452 }
 453
 454 DeviceState *qdev_device_add(QemuOpts *opts)
 455 {
 456     ObjectClass *obj;
 457     DeviceClass *k;
 458     const char *driver, *path, *id;
 459     DeviceState *qdev;
 460     BusState *bus = NULL;
 461
 462     driver = qemu_opt_get(opts, "driver");
 463     if (!driver) {
 464         qerror_report(QERR_MISSING_PARAMETER, "driver");
 465         return NULL;
 466     }
 467
 468     /* find driver */
 469     obj = object_class_by_name(driver);
 470     if (!obj) {
 471         const char *typename = find_typename_by_alias(driver);
 472
 473         if (typename) {
 474             driver = typename;
 475             obj = object_class_by_name(driver);
 476         }
 477     }
 478
 479     if (!obj) {
 480         qerror_report(QERR_INVALID_PARAMETER_VALUE, "driver", "device type");
 481         return NULL;
 482     }
 483
 484     k = DEVICE_CLASS(obj);
 485
 486     /* find bus */
 487     path = qemu_opt_get(opts, "bus");
 488     if (path != NULL) {
 489         bus = qbus_find(path);
 490         if (!bus) {
 491             return NULL;
 492         }
 493         if (!object_dynamic_cast(OBJECT(bus), k->bus_type)) {
 494             qerror_report(QERR_BAD_BUS_FOR_DEVICE,
 495                           driver, object_get_typename(OBJECT(bus)));
 496             return NULL;
 497         }
 498     } else if (k->bus_type != NULL) {
 499         bus = qbus_find_recursive(sysbus_get_default(), NULL, k->bus_type);
 500         if (!bus) {
 501             qerror_report(QERR_NO_BUS_FOR_DEVICE,
 502                           k->bus_type, driver);
 503             return NULL;
 504         }
 505     }
 506     if (qdev_hotplug && bus && !bus->allow_hotplug) {
 507         qerror_report(QERR_BUS_NO_HOTPLUG, bus->name);
 508         return NULL;
 509     }
 510
 511     /* create device, set properties */
 512     qdev = DEVICE(object_new(driver));
 513
 514     if (bus) {
 515         qdev_set_parent_bus(qdev, bus);
 516     }
 517
 518     id = qemu_opts_id(opts);
 519     if (id) {
 520         qdev->id = id;
 521     }
 522     if (qemu_opt_foreach(opts, set_property, qdev, 1) != 0) {
 523         qdev_free(qdev);
 524         return NULL;
 525     }
 526     if (qdev->id) {
 527         object_property_add_child(qdev_get_peripheral(), qdev->id,
 528                                   OBJECT(qdev), NULL);
 529     } else {
 530         static int anon_count;
 531         gchar *name = g_strdup_printf("device[%d]", anon_count++);
 532         object_property_add_child(qdev_get_peripheral_anon(), name,
 533                                   OBJECT(qdev), NULL);
 534         g_free(name);
 535     }
 536     if (qdev_init(qdev) < 0) {
 537         qerror_report(QERR_DEVICE_INIT_FAILED, driver);
 538         return NULL;
 539     }
 540     qdev->opts = opts;
 541     return qdev;
 542 }
 543
 544
 545 #define qdev_printf(fmt, ...) monitor_printf(mon, "%*s" fmt, indent, "", ## __VA_ARGS__)
 546 static void qbus_print(Monitor *mon, BusState *bus, int indent);
 547
 548 static void qdev_print_props(Monitor *mon, DeviceState *dev, Property *props,
 549                              int indent)
 550 {
 551     if (!props)
 552         return;
 553     for (; props->name; props++) {
 554         Error *err = NULL;
 555         char *value;
 556         char *legacy_name = g_strdup_printf("legacy-%s", props->name);
 557         if (object_property_get_type(OBJECT(dev), legacy_name, NULL)) {
 558             value = object_property_get_str(OBJECT(dev), legacy_name, &err);
 559         } else {
 560             value = object_property_print(OBJECT(dev), props->name, &err);
 561         }
 562         g_free(legacy_name);
 563
 564         if (err) {
 565             error_free(err);
 566             continue;
 567         }
 568         qdev_printf("%s = %s\n", props->name,
 569                     value && *value ? value : "<null>");
 570         g_free(value);
 571     }
 572 }
 573
 574 static void bus_print_dev(BusState *bus, Monitor *mon, DeviceState *dev, int indent)
 575 {
 576     BusClass *bc = BUS_GET_CLASS(bus);
 577
 578     if (bc->print_dev) {
 579         bc->print_dev(mon, dev, indent);
 580     }
 581 }
 582
 583 static void qdev_print(Monitor *mon, DeviceState *dev, int indent)
 584 {
 585     ObjectClass *class;
 586     BusState *child;
 587     qdev_printf("dev: %s, id \"%s\"\n", object_get_typename(OBJECT(dev)),
 588                 dev->id ? dev->id : "");
 589     indent += 2;
 590     if (dev->num_gpio_in) {
 591         qdev_printf("gpio-in %d\n", dev->num_gpio_in);
 592     }
 593     if (dev->num_gpio_out) {
 594         qdev_printf("gpio-out %d\n", dev->num_gpio_out);
 595     }
 596     class = object_get_class(OBJECT(dev));
 597     do {
 598         qdev_print_props(mon, dev, DEVICE_CLASS(class)->props, indent);
 599         class = object_class_get_parent(class);
 600     } while (class != object_class_by_name(TYPE_DEVICE));
 601     bus_print_dev(dev->parent_bus, mon, dev, indent);
 602     QLIST_FOREACH(child, &dev->child_bus, sibling) {
 603         qbus_print(mon, child, indent);
 604     }
 605 }
 606
 607 static void qbus_print(Monitor *mon, BusState *bus, int indent)
 608 {
 609     BusChild *kid;
 610
 611     qdev_printf("bus: %s\n", bus->name);
 612     indent += 2;
 613     qdev_printf("type %s\n", object_get_typename(OBJECT(bus)));
 614     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 615         DeviceState *dev = kid->child;
 616         qdev_print(mon, dev, indent);
 617     }
 618 }
 619 #undef qdev_printf
 620
 621 void do_info_qtree(Monitor *mon, const QDict *qdict)
 622 {
 623     if (sysbus_get_default())
 624         qbus_print(mon, sysbus_get_default(), 0);
 625 }
 626
 627 void do_info_qdm(Monitor *mon, const QDict *qdict)
 628 {
 629     qdev_print_devinfos(true);
 630 }
 631
 632 int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data)
 633 {
 634     Error *local_err = NULL;
 635     QemuOpts *opts;
 636     DeviceState *dev;
 637
 638     opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, &local_err);
 639     if (error_is_set(&local_err)) {
 640         qerror_report_err(local_err);
 641         error_free(local_err);
 642         return -1;
 643     }
 644     if (!monitor_cur_is_qmp() && qdev_device_help(opts)) {
 645         qemu_opts_del(opts);
 646         return 0;
 647     }
 648     dev = qdev_device_add(opts);
 649     if (!dev) {
 650         qemu_opts_del(opts);
 651         return -1;
 652     }
 653     object_unref(OBJECT(dev));
 654     return 0;
 655 }
 656
 657 void qmp_device_del(const char *id, Error **errp)
 658 {
 659     DeviceState *dev;
 660
 661     dev = qdev_find_recursive(sysbus_get_default(), id);
 662     if (NULL == dev) {
 663         error_set(errp, QERR_DEVICE_NOT_FOUND, id);
 664         return;
 665     }
 666
 667     qdev_unplug(dev, errp);
 668 }
 669
 670 void qdev_machine_init(void)
 671 {
 672     qdev_get_peripheral_anon();
 673     qdev_get_peripheral();
 674 }
 675
 676 QemuOptsList qemu_device_opts = {
 677     .name = "device",
 678     .implied_opt_name = "driver",
 679     .head = QTAILQ_HEAD_INITIALIZER(qemu_device_opts.head),
 680     .desc = {
 681         /*
 682          * no elements => accept any
 683          * sanity checking will happen later
 684          * when setting device properties
 685          */
 686         { /* end of list */ }
 687     },
 688 };
 689
 690 QemuOptsList qemu_global_opts = {
 691     .name = "global",
 692     .head = QTAILQ_HEAD_INITIALIZER(qemu_global_opts.head),
 693     .desc = {
 694         {
 695             .name = "driver",
 696             .type = QEMU_OPT_STRING,
 697         },{
 698             .name = "property",
 699             .type = QEMU_OPT_STRING,
 700         },{
 701             .name = "value",
 702             .type = QEMU_OPT_STRING,
 703         },
 704         { /* end of list */ }
 705     },
 706 };
 707
 708 int qemu_global_option(const char *str)
 709 {
 710     char driver[64], property[64];
 711     QemuOpts *opts;
 712     int rc, offset;
 713
 714     rc = sscanf(str, "%63[^.].%63[^=]%n", driver, property, &offset);
 715     if (rc < 2 || str[offset] != '=') {
 716         error_report("can't parse: \"%s\"", str);
 717         return -1;
 718     }
 719
 720     opts = qemu_opts_create_nofail(&qemu_global_opts);
 721     qemu_opt_set(opts, "driver", driver);
 722     qemu_opt_set(opts, "property", property);
 723     qemu_opt_set(opts, "value", str+offset+1);
 724     return 0;
 725 }