hw/xen/xen_backend.c

   1 /*
   2  *  xen backend driver infrastructure
   3  *  (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; under version 2 of the License.
   8  *
   9  *  This program is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, see <http://www.gnu.org/licenses/>.
  16  *
  17  *  Contributions after 2012-01-13 are licensed under the terms of the
  18  *  GNU GPL, version 2 or (at your option) any later version.
  19  */
  20
  21 /*
  22  * TODO: add some xenbus / xenstore concepts overview here.
  23  */
  24
  25 #include "qemu/osdep.h"
  26 #include <sys/signal.h>
  27
  28 #include "hw/hw.h"
  29 #include "hw/sysbus.h"
  30 #include "sysemu/char.h"
  31 #include "qemu/log.h"
  32 #include "hw/xen/xen_backend.h"
  33 #include "hw/xen/xen_pvdev.h"
  34
  35 #include <xen/grant_table.h>
  36
  37 #define TYPE_XENSYSDEV "xensysdev"
  38
  39 DeviceState *xen_sysdev;
  40
  41 /* ------------------------------------------------------------- */
  42
  43 /* public */
  44 xc_interface *xen_xc = NULL;
  45 xenforeignmemory_handle *xen_fmem = NULL;
  46 struct xs_handle *xenstore = NULL;
  47 const char *xen_protocol;
  48
  49 /* private */
  50 struct xs_dirs {
  51     char *xs_dir;
  52     QTAILQ_ENTRY(xs_dirs) list;
  53 };
  54 static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup =
  55     QTAILQ_HEAD_INITIALIZER(xs_cleanup);
  56
  57 static QTAILQ_HEAD(XenDeviceHead, XenDevice) xendevs =
  58     QTAILQ_HEAD_INITIALIZER(xendevs);
  59 static int debug;
  60
  61 static void xenstore_cleanup_dir(char *dir)
  62 {
  63     struct xs_dirs *d;
  64
  65     d = g_malloc(sizeof(*d));
  66     d->xs_dir = dir;
  67     QTAILQ_INSERT_TAIL(&xs_cleanup, d, list);
  68 }
  69
  70 void xen_config_cleanup(void)
  71 {
  72     struct xs_dirs *d;
  73
  74     QTAILQ_FOREACH(d, &xs_cleanup, list) {
  75         xs_rm(xenstore, 0, d->xs_dir);
  76     }
  77 }
  78
  79 int xenstore_mkdir(char *path, int p)
  80 {
  81     struct xs_permissions perms[2] = {
  82         {
  83             .id    = 0, /* set owner: dom0 */
  84         }, {
  85             .id    = xen_domid,
  86             .perms = p,
  87         }
  88     };
  89
  90     if (!xs_mkdir(xenstore, 0, path)) {
  91         xen_be_printf(NULL, 0, "xs_mkdir %s: failed\n", path);
  92         return -1;
  93     }
  94     xenstore_cleanup_dir(g_strdup(path));
  95
  96     if (!xs_set_permissions(xenstore, 0, path, perms, 2)) {
  97         xen_be_printf(NULL, 0, "xs_set_permissions %s: failed\n", path);
  98         return -1;
  99     }
 100     return 0;
 101 }
 102
 103 int xenstore_write_be_str(struct XenDevice *xendev, const char *node, const char *val)
 104 {
 105     return xenstore_write_str(xendev->be, node, val);
 106 }
 107
 108 int xenstore_write_be_int(struct XenDevice *xendev, const char *node, int ival)
 109 {
 110     return xenstore_write_int(xendev->be, node, ival);
 111 }
 112
 113 int xenstore_write_be_int64(struct XenDevice *xendev, const char *node, int64_t ival)
 114 {
 115     return xenstore_write_int64(xendev->be, node, ival);
 116 }
 117
 118 char *xenstore_read_be_str(struct XenDevice *xendev, const char *node)
 119 {
 120     return xenstore_read_str(xendev->be, node);
 121 }
 122
 123 int xenstore_read_be_int(struct XenDevice *xendev, const char *node, int *ival)
 124 {
 125     return xenstore_read_int(xendev->be, node, ival);
 126 }
 127
 128 char *xenstore_read_fe_str(struct XenDevice *xendev, const char *node)
 129 {
 130     return xenstore_read_str(xendev->fe, node);
 131 }
 132
 133 int xenstore_read_fe_int(struct XenDevice *xendev, const char *node, int *ival)
 134 {
 135     return xenstore_read_int(xendev->fe, node, ival);
 136 }
 137
 138 int xenstore_read_fe_uint64(struct XenDevice *xendev, const char *node,
 139                             uint64_t *uval)
 140 {
 141     return xenstore_read_uint64(xendev->fe, node, uval);
 142 }
 143
 144 /* ------------------------------------------------------------- */
 145
 146 int xen_be_set_state(struct XenDevice *xendev, enum xenbus_state state)
 147 {
 148     int rc;
 149
 150     rc = xenstore_write_be_int(xendev, "state", state);
 151     if (rc < 0) {
 152         return rc;
 153     }
 154     xen_be_printf(xendev, 1, "backend state: %s -> %s\n",
 155                   xenbus_strstate(xendev->be_state), xenbus_strstate(state));
 156     xendev->be_state = state;
 157     return 0;
 158 }
 159
 160 /* ------------------------------------------------------------- */
 161
 162 struct XenDevice *xen_be_find_xendev(const char *type, int dom, int dev)
 163 {
 164     struct XenDevice *xendev;
 165
 166     QTAILQ_FOREACH(xendev, &xendevs, next) {
 167         if (xendev->dom != dom) {
 168             continue;
 169         }
 170         if (xendev->dev != dev) {
 171             continue;
 172         }
 173         if (strcmp(xendev->type, type) != 0) {
 174             continue;
 175         }
 176         return xendev;
 177     }
 178     return NULL;
 179 }
 180
 181 /*
 182  * get xen backend device, allocate a new one if it doesn't exist.
 183  */
 184 static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
 185                                            struct XenDevOps *ops)
 186 {
 187     struct XenDevice *xendev;
 188
 189     xendev = xen_be_find_xendev(type, dom, dev);
 190     if (xendev) {
 191         return xendev;
 192     }
 193
 194     /* init new xendev */
 195     xendev = g_malloc0(ops->size);
 196     xendev->type  = type;
 197     xendev->dom   = dom;
 198     xendev->dev   = dev;
 199     xendev->ops   = ops;
 200
 201     snprintf(xendev->be, sizeof(xendev->be), "backend/%s/%d/%d",
 202              xendev->type, xendev->dom, xendev->dev);
 203     snprintf(xendev->name, sizeof(xendev->name), "%s-%d",
 204              xendev->type, xendev->dev);
 205
 206     xendev->debug      = debug;
 207     xendev->local_port = -1;
 208
 209     xendev->evtchndev = xenevtchn_open(NULL, 0);
 210     if (xendev->evtchndev == NULL) {
 211         xen_be_printf(NULL, 0, "can't open evtchn device\n");
 212         g_free(xendev);
 213         return NULL;
 214     }
 215     fcntl(xenevtchn_fd(xendev->evtchndev), F_SETFD, FD_CLOEXEC);
 216
 217     if (ops->flags & DEVOPS_FLAG_NEED_GNTDEV) {
 218         xendev->gnttabdev = xengnttab_open(NULL, 0);
 219         if (xendev->gnttabdev == NULL) {
 220             xen_be_printf(NULL, 0, "can't open gnttab device\n");
 221             xenevtchn_close(xendev->evtchndev);
 222             g_free(xendev);
 223             return NULL;
 224         }
 225     } else {
 226         xendev->gnttabdev = NULL;
 227     }
 228
 229     QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
 230
 231     if (xendev->ops->alloc) {
 232         xendev->ops->alloc(xendev);
 233     }
 234
 235     return xendev;
 236 }
 237
 238 /*
 239  * release xen backend device.
 240  */
 241 static void xen_be_del_xendev(struct XenDevice *xendev)
 242 {
 243     if (xendev->ops->free) {
 244         xendev->ops->free(xendev);
 245     }
 246
 247     if (xendev->fe) {
 248         char token[XEN_BUFSIZE];
 249         snprintf(token, sizeof(token), "fe:%p", xendev);
 250         xs_unwatch(xenstore, xendev->fe, token);
 251         g_free(xendev->fe);
 252     }
 253
 254     if (xendev->evtchndev != NULL) {
 255         xenevtchn_close(xendev->evtchndev);
 256     }
 257     if (xendev->gnttabdev != NULL) {
 258         xengnttab_close(xendev->gnttabdev);
 259     }
 260
 261     QTAILQ_REMOVE(&xendevs, xendev, next);
 262     g_free(xendev);
 263 }
 264
 265 /*
 266  * Sync internal data structures on xenstore updates.
 267  * Node specifies the changed field.  node = NULL means
 268  * update all fields (used for initialization).
 269  */
 270 static void xen_be_backend_changed(struct XenDevice *xendev, const char *node)
 271 {
 272     if (node == NULL  ||  strcmp(node, "online") == 0) {
 273         if (xenstore_read_be_int(xendev, "online", &xendev->online) == -1) {
 274             xendev->online = 0;
 275         }
 276     }
 277
 278     if (node) {
 279         xen_be_printf(xendev, 2, "backend update: %s\n", node);
 280         if (xendev->ops->backend_changed) {
 281             xendev->ops->backend_changed(xendev, node);
 282         }
 283     }
 284 }
 285
 286 static void xen_be_frontend_changed(struct XenDevice *xendev, const char *node)
 287 {
 288     int fe_state;
 289
 290     if (node == NULL  ||  strcmp(node, "state") == 0) {
 291         if (xenstore_read_fe_int(xendev, "state", &fe_state) == -1) {
 292             fe_state = XenbusStateUnknown;
 293         }
 294         if (xendev->fe_state != fe_state) {
 295             xen_be_printf(xendev, 1, "frontend state: %s -> %s\n",
 296                           xenbus_strstate(xendev->fe_state),
 297                           xenbus_strstate(fe_state));
 298         }
 299         xendev->fe_state = fe_state;
 300     }
 301     if (node == NULL  ||  strcmp(node, "protocol") == 0) {
 302         g_free(xendev->protocol);
 303         xendev->protocol = xenstore_read_fe_str(xendev, "protocol");
 304         if (xendev->protocol) {
 305             xen_be_printf(xendev, 1, "frontend protocol: %s\n",
 306                           xendev->protocol);
 307         }
 308     }
 309
 310     if (node) {
 311         xen_be_printf(xendev, 2, "frontend update: %s\n", node);
 312         if (xendev->ops->frontend_changed) {
 313             xendev->ops->frontend_changed(xendev, node);
 314         }
 315     }
 316 }
 317
 318 /* ------------------------------------------------------------- */
 319 /* Check for possible state transitions and perform them.        */
 320
 321 /*
 322  * Initial xendev setup.  Read frontend path, register watch for it.
 323  * Should succeed once xend finished setting up the backend device.
 324  *
 325  * Also sets initial state (-> Initializing) when done.  Which
 326  * only affects the xendev->be_state variable as xenbus should
 327  * already be put into that state by xend.
 328  */
 329 static int xen_be_try_setup(struct XenDevice *xendev)
 330 {
 331     char token[XEN_BUFSIZE];
 332     int be_state;
 333
 334     if (xenstore_read_be_int(xendev, "state", &be_state) == -1) {
 335         xen_be_printf(xendev, 0, "reading backend state failed\n");
 336         return -1;
 337     }
 338
 339     if (be_state != XenbusStateInitialising) {
 340         xen_be_printf(xendev, 0, "initial backend state is wrong (%s)\n",
 341                       xenbus_strstate(be_state));
 342         return -1;
 343     }
 344
 345     xendev->fe = xenstore_read_be_str(xendev, "frontend");
 346     if (xendev->fe == NULL) {
 347         xen_be_printf(xendev, 0, "reading frontend path failed\n");
 348         return -1;
 349     }
 350
 351     /* setup frontend watch */
 352     snprintf(token, sizeof(token), "fe:%p", xendev);
 353     if (!xs_watch(xenstore, xendev->fe, token)) {
 354         xen_be_printf(xendev, 0, "watching frontend path (%s) failed\n",
 355                       xendev->fe);
 356         return -1;
 357     }
 358     xen_be_set_state(xendev, XenbusStateInitialising);
 359
 360     xen_be_backend_changed(xendev, NULL);
 361     xen_be_frontend_changed(xendev, NULL);
 362     return 0;
 363 }
 364
 365 /*
 366  * Try initialize xendev.  Prepare everything the backend can do
 367  * without synchronizing with the frontend.  Fakes hotplug-status.  No
 368  * hotplug involved here because this is about userspace drivers, thus
 369  * there are kernel backend devices which could invoke hotplug.
 370  *
 371  * Goes to InitWait on success.
 372  */
 373 static int xen_be_try_init(struct XenDevice *xendev)
 374 {
 375     int rc = 0;
 376
 377     if (!xendev->online) {
 378         xen_be_printf(xendev, 1, "not online\n");
 379         return -1;
 380     }
 381
 382     if (xendev->ops->init) {
 383         rc = xendev->ops->init(xendev);
 384     }
 385     if (rc != 0) {
 386         xen_be_printf(xendev, 1, "init() failed\n");
 387         return rc;
 388     }
 389
 390     xenstore_write_be_str(xendev, "hotplug-status", "connected");
 391     xen_be_set_state(xendev, XenbusStateInitWait);
 392     return 0;
 393 }
 394
 395 /*
 396  * Try to initialise xendev.  Depends on the frontend being ready
 397  * for it (shared ring and evtchn info in xenstore, state being
 398  * Initialised or Connected).
 399  *
 400  * Goes to Connected on success.
 401  */
 402 static int xen_be_try_initialise(struct XenDevice *xendev)
 403 {
 404     int rc = 0;
 405
 406     if (xendev->fe_state != XenbusStateInitialised  &&
 407         xendev->fe_state != XenbusStateConnected) {
 408         if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
 409             xen_be_printf(xendev, 2, "frontend not ready, ignoring\n");
 410         } else {
 411             xen_be_printf(xendev, 2, "frontend not ready (yet)\n");
 412             return -1;
 413         }
 414     }
 415
 416     if (xendev->ops->initialise) {
 417         rc = xendev->ops->initialise(xendev);
 418     }
 419     if (rc != 0) {
 420         xen_be_printf(xendev, 0, "initialise() failed\n");
 421         return rc;
 422     }
 423
 424     xen_be_set_state(xendev, XenbusStateConnected);
 425     return 0;
 426 }
 427
 428 /*
 429  * Try to let xendev know that it is connected.  Depends on the
 430  * frontend being Connected.  Note that this may be called more
 431  * than once since the backend state is not modified.
 432  */
 433 static void xen_be_try_connected(struct XenDevice *xendev)
 434 {
 435     if (!xendev->ops->connected) {
 436         return;
 437     }
 438
 439     if (xendev->fe_state != XenbusStateConnected) {
 440         if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
 441             xen_be_printf(xendev, 2, "frontend not ready, ignoring\n");
 442         } else {
 443             xen_be_printf(xendev, 2, "frontend not ready (yet)\n");
 444             return;
 445         }
 446     }
 447
 448     xendev->ops->connected(xendev);
 449 }
 450
 451 /*
 452  * Teardown connection.
 453  *
 454  * Goes to Closed when done.
 455  */
 456 static void xen_be_disconnect(struct XenDevice *xendev, enum xenbus_state state)
 457 {
 458     if (xendev->be_state != XenbusStateClosing &&
 459         xendev->be_state != XenbusStateClosed  &&
 460         xendev->ops->disconnect) {
 461         xendev->ops->disconnect(xendev);
 462     }
 463     if (xendev->be_state != state) {
 464         xen_be_set_state(xendev, state);
 465     }
 466 }
 467
 468 /*
 469  * Try to reset xendev, for reconnection by another frontend instance.
 470  */
 471 static int xen_be_try_reset(struct XenDevice *xendev)
 472 {
 473     if (xendev->fe_state != XenbusStateInitialising) {
 474         return -1;
 475     }
 476
 477     xen_be_printf(xendev, 1, "device reset (for re-connect)\n");
 478     xen_be_set_state(xendev, XenbusStateInitialising);
 479     return 0;
 480 }
 481
 482 /*
 483  * state change dispatcher function
 484  */
 485 void xen_be_check_state(struct XenDevice *xendev)
 486 {
 487     int rc = 0;
 488
 489     /* frontend may request shutdown from almost anywhere */
 490     if (xendev->fe_state == XenbusStateClosing ||
 491         xendev->fe_state == XenbusStateClosed) {
 492         xen_be_disconnect(xendev, xendev->fe_state);
 493         return;
 494     }
 495
 496     /* check for possible backend state transitions */
 497     for (;;) {
 498         switch (xendev->be_state) {
 499         case XenbusStateUnknown:
 500             rc = xen_be_try_setup(xendev);
 501             break;
 502         case XenbusStateInitialising:
 503             rc = xen_be_try_init(xendev);
 504             break;
 505         case XenbusStateInitWait:
 506             rc = xen_be_try_initialise(xendev);
 507             break;
 508         case XenbusStateConnected:
 509             /* xendev->be_state doesn't change */
 510             xen_be_try_connected(xendev);
 511             rc = -1;
 512             break;
 513         case XenbusStateClosed:
 514             rc = xen_be_try_reset(xendev);
 515             break;
 516         default:
 517             rc = -1;
 518         }
 519         if (rc != 0) {
 520             break;
 521         }
 522     }
 523 }
 524
 525 /* ------------------------------------------------------------- */
 526
 527 static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
 528 {
 529     struct XenDevice *xendev;
 530     char path[XEN_BUFSIZE], token[XEN_BUFSIZE];
 531     char **dev = NULL;
 532     unsigned int cdev, j;
 533
 534     /* setup watch */
 535     snprintf(token, sizeof(token), "be:%p:%d:%p", type, dom, ops);
 536     snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
 537     if (!xs_watch(xenstore, path, token)) {
 538         xen_be_printf(NULL, 0, "xen be: watching backend path (%s) failed\n",
 539                       path);
 540         return -1;
 541     }
 542
 543     /* look for backends */
 544     dev = xs_directory(xenstore, 0, path, &cdev);
 545     if (!dev) {
 546         return 0;
 547     }
 548     for (j = 0; j < cdev; j++) {
 549         xendev = xen_be_get_xendev(type, dom, atoi(dev[j]), ops);
 550         if (xendev == NULL) {
 551             continue;
 552         }
 553         xen_be_check_state(xendev);
 554     }
 555     free(dev);
 556     return 0;
 557 }
 558
 559 static void xenstore_update_be(char *watch, char *type, int dom,
 560                                struct XenDevOps *ops)
 561 {
 562     struct XenDevice *xendev;
 563     char path[XEN_BUFSIZE], *bepath;
 564     unsigned int len, dev;
 565
 566     len = snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
 567     if (strncmp(path, watch, len) != 0) {
 568         return;
 569     }
 570     if (sscanf(watch+len, "/%u/%255s", &dev, path) != 2) {
 571         strcpy(path, "");
 572         if (sscanf(watch+len, "/%u", &dev) != 1) {
 573             dev = -1;
 574         }
 575     }
 576     if (dev == -1) {
 577         return;
 578     }
 579
 580     xendev = xen_be_get_xendev(type, dom, dev, ops);
 581     if (xendev != NULL) {
 582         bepath = xs_read(xenstore, 0, xendev->be, &len);
 583         if (bepath == NULL) {
 584             xen_be_del_xendev(xendev);
 585         } else {
 586             free(bepath);
 587             xen_be_backend_changed(xendev, path);
 588             xen_be_check_state(xendev);
 589         }
 590     }
 591 }
 592
 593 static void xenstore_update_fe(char *watch, struct XenDevice *xendev)
 594 {
 595     char *node;
 596     unsigned int len;
 597
 598     len = strlen(xendev->fe);
 599     if (strncmp(xendev->fe, watch, len) != 0) {
 600         return;
 601     }
 602     if (watch[len] != '/') {
 603         return;
 604     }
 605     node = watch + len + 1;
 606
 607     xen_be_frontend_changed(xendev, node);
 608     xen_be_check_state(xendev);
 609 }
 610
 611 static void xenstore_update(void *unused)
 612 {
 613     char **vec = NULL;
 614     intptr_t type, ops, ptr;
 615     unsigned int dom, count;
 616
 617     vec = xs_read_watch(xenstore, &count);
 618     if (vec == NULL) {
 619         goto cleanup;
 620     }
 621
 622     if (sscanf(vec[XS_WATCH_TOKEN], "be:%" PRIxPTR ":%d:%" PRIxPTR,
 623                &type, &dom, &ops) == 3) {
 624         xenstore_update_be(vec[XS_WATCH_PATH], (void *)type, dom, (void*)ops);
 625     }
 626     if (sscanf(vec[XS_WATCH_TOKEN], "fe:%" PRIxPTR, &ptr) == 1) {
 627         xenstore_update_fe(vec[XS_WATCH_PATH], (void *)ptr);
 628     }
 629
 630 cleanup:
 631     free(vec);
 632 }
 633
 634 static void xen_be_evtchn_event(void *opaque)
 635 {
 636     struct XenDevice *xendev = opaque;
 637     evtchn_port_t port;
 638
 639     port = xenevtchn_pending(xendev->evtchndev);
 640     if (port != xendev->local_port) {
 641         xen_be_printf(xendev, 0,
 642                       "xenevtchn_pending returned %d (expected %d)\n",
 643                       port, xendev->local_port);
 644         return;
 645     }
 646     xenevtchn_unmask(xendev->evtchndev, port);
 647
 648     if (xendev->ops->event) {
 649         xendev->ops->event(xendev);
 650     }
 651 }
 652
 653 /* -------------------------------------------------------------------- */
 654
 655 int xen_be_init(void)
 656 {
 657     xenstore = xs_daemon_open();
 658     if (!xenstore) {
 659         xen_be_printf(NULL, 0, "can't connect to xenstored\n");
 660         return -1;
 661     }
 662
 663     qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL);
 664
 665     if (xen_xc == NULL || xen_fmem == NULL) {
 666         /* Check if xen_init() have been called */
 667         goto err;
 668     }
 669
 670     xen_sysdev = qdev_create(NULL, TYPE_XENSYSDEV);
 671     qdev_init_nofail(xen_sysdev);
 672
 673     return 0;
 674
 675 err:
 676     qemu_set_fd_handler(xs_fileno(xenstore), NULL, NULL, NULL);
 677     xs_daemon_close(xenstore);
 678     xenstore = NULL;
 679
 680     return -1;
 681 }
 682
 683 int xen_be_register(const char *type, struct XenDevOps *ops)
 684 {
 685     char path[50];
 686     int rc;
 687
 688     if (ops->backend_register) {
 689         rc = ops->backend_register();
 690         if (rc) {
 691             return rc;
 692         }
 693     }
 694
 695     snprintf(path, sizeof(path), "device-model/%u/backends/%s", xen_domid,
 696              type);
 697     xenstore_mkdir(path, XS_PERM_NONE);
 698
 699     return xenstore_scan(type, xen_domid, ops);
 700 }
 701
 702 void xen_be_register_common(void)
 703 {
 704     xen_be_register("console", &xen_console_ops);
 705     xen_be_register("vkbd", &xen_kbdmouse_ops);
 706     xen_be_register("qdisk", &xen_blkdev_ops);
 707 #ifdef CONFIG_USB_LIBUSB
 708     xen_be_register("qusb", &xen_usb_ops);
 709 #endif
 710 }
 711
 712 int xen_be_bind_evtchn(struct XenDevice *xendev)
 713 {
 714     if (xendev->local_port != -1) {
 715         return 0;
 716     }
 717     xendev->local_port = xenevtchn_bind_interdomain
 718         (xendev->evtchndev, xendev->dom, xendev->remote_port);
 719     if (xendev->local_port == -1) {
 720         xen_be_printf(xendev, 0, "xenevtchn_bind_interdomain failed\n");
 721         return -1;
 722     }
 723     xen_be_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
 724     qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev),
 725                         xen_be_evtchn_event, NULL, xendev);
 726     return 0;
 727 }
 728
 729 void xen_be_unbind_evtchn(struct XenDevice *xendev)
 730 {
 731     if (xendev->local_port == -1) {
 732         return;
 733     }
 734     qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev), NULL, NULL, NULL);
 735     xenevtchn_unbind(xendev->evtchndev, xendev->local_port);
 736     xen_be_printf(xendev, 2, "unbind evtchn port %d\n", xendev->local_port);
 737     xendev->local_port = -1;
 738 }
 739
 740 int xen_be_send_notify(struct XenDevice *xendev)
 741 {
 742     return xenevtchn_notify(xendev->evtchndev, xendev->local_port);
 743 }
 744
 745
 746 static int xen_sysdev_init(SysBusDevice *dev)
 747 {
 748     return 0;
 749 }
 750
 751 static Property xen_sysdev_properties[] = {
 752     {/* end of property list */},
 753 };
 754
 755 static void xen_sysdev_class_init(ObjectClass *klass, void *data)
 756 {
 757     DeviceClass *dc = DEVICE_CLASS(klass);
 758     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 759
 760     k->init = xen_sysdev_init;
 761     dc->props = xen_sysdev_properties;
 762 }
 763
 764 static const TypeInfo xensysdev_info = {
 765     .name          = TYPE_XENSYSDEV,
 766     .parent        = TYPE_SYS_BUS_DEVICE,
 767     .instance_size = sizeof(SysBusDevice),
 768     .class_init    = xen_sysdev_class_init,
 769 };
 770
 771 static void xenbe_register_types(void)
 772 {
 773     type_register_static(&xensysdev_info);
 774 }
 775
 776 type_init(xenbe_register_types);