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 "hw/boards.h"
  31 #include "qemu/log.h"
  32 #include "qapi/error.h"
  33 #include "hw/xen/xen_backend.h"
  34 #include "hw/xen/xen_pvdev.h"
  35 #include "monitor/qdev.h"
  36
  37 #include <xen/grant_table.h>
  38
  39 DeviceState *xen_sysdev;
  40 BusState *xen_sysbus;
  41
  42 /* ------------------------------------------------------------- */
  43
  44 /* public */
  45 struct xs_handle *xenstore = NULL;
  46 const char *xen_protocol;
  47
  48 /* private */
  49 static bool xen_feature_grant_copy;
  50 static int debug;
  51
  52 int xenstore_write_be_str(struct XenDevice *xendev, const char *node, const char *val)
  53 {
  54     return xenstore_write_str(xendev->be, node, val);
  55 }
  56
  57 int xenstore_write_be_int(struct XenDevice *xendev, const char *node, int ival)
  58 {
  59     return xenstore_write_int(xendev->be, node, ival);
  60 }
  61
  62 int xenstore_write_be_int64(struct XenDevice *xendev, const char *node, int64_t ival)
  63 {
  64     return xenstore_write_int64(xendev->be, node, ival);
  65 }
  66
  67 char *xenstore_read_be_str(struct XenDevice *xendev, const char *node)
  68 {
  69     return xenstore_read_str(xendev->be, node);
  70 }
  71
  72 int xenstore_read_be_int(struct XenDevice *xendev, const char *node, int *ival)
  73 {
  74     return xenstore_read_int(xendev->be, node, ival);
  75 }
  76
  77 char *xenstore_read_fe_str(struct XenDevice *xendev, const char *node)
  78 {
  79     return xenstore_read_str(xendev->fe, node);
  80 }
  81
  82 int xenstore_read_fe_int(struct XenDevice *xendev, const char *node, int *ival)
  83 {
  84     return xenstore_read_int(xendev->fe, node, ival);
  85 }
  86
  87 int xenstore_read_fe_uint64(struct XenDevice *xendev, const char *node,
  88                             uint64_t *uval)
  89 {
  90     return xenstore_read_uint64(xendev->fe, node, uval);
  91 }
  92
  93 /* ------------------------------------------------------------- */
  94
  95 int xen_be_set_state(struct XenDevice *xendev, enum xenbus_state state)
  96 {
  97     int rc;
  98
  99     rc = xenstore_write_be_int(xendev, "state", state);
 100     if (rc < 0) {
 101         return rc;
 102     }
 103     xen_pv_printf(xendev, 1, "backend state: %s -> %s\n",
 104                   xenbus_strstate(xendev->be_state), xenbus_strstate(state));
 105     xendev->be_state = state;
 106     return 0;
 107 }
 108
 109 void xen_be_set_max_grant_refs(struct XenDevice *xendev,
 110                                unsigned int nr_refs)
 111 {
 112     assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV);
 113
 114     if (xengnttab_set_max_grants(xendev->gnttabdev, nr_refs)) {
 115         xen_pv_printf(xendev, 0, "xengnttab_set_max_grants failed: %s\n",
 116                       strerror(errno));
 117     }
 118 }
 119
 120 void *xen_be_map_grant_refs(struct XenDevice *xendev, uint32_t *refs,
 121                             unsigned int nr_refs, int prot)
 122 {
 123     void *ptr;
 124
 125     assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV);
 126
 127     ptr = xengnttab_map_domain_grant_refs(xendev->gnttabdev, nr_refs,
 128                                           xen_domid, refs, prot);
 129     if (!ptr) {
 130         xen_pv_printf(xendev, 0,
 131                       "xengnttab_map_domain_grant_refs failed: %s\n",
 132                       strerror(errno));
 133     }
 134
 135     return ptr;
 136 }
 137
 138 void xen_be_unmap_grant_refs(struct XenDevice *xendev, void *ptr,
 139                              unsigned int nr_refs)
 140 {
 141     assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV);
 142
 143     if (xengnttab_unmap(xendev->gnttabdev, ptr, nr_refs)) {
 144         xen_pv_printf(xendev, 0, "xengnttab_unmap failed: %s\n",
 145                       strerror(errno));
 146     }
 147 }
 148
 149 static int compat_copy_grant_refs(struct XenDevice *xendev,
 150                                   bool to_domain,
 151                                   XenGrantCopySegment segs[],
 152                                   unsigned int nr_segs)
 153 {
 154     uint32_t *refs = g_new(uint32_t, nr_segs);
 155     int prot = to_domain ? PROT_WRITE : PROT_READ;
 156     void *pages;
 157     unsigned int i;
 158
 159     for (i = 0; i < nr_segs; i++) {
 160         XenGrantCopySegment *seg = &segs[i];
 161
 162         refs[i] = to_domain ?
 163             seg->dest.foreign.ref : seg->source.foreign.ref;
 164     }
 165
 166     pages = xengnttab_map_domain_grant_refs(xendev->gnttabdev, nr_segs,
 167                                             xen_domid, refs, prot);
 168     if (!pages) {
 169         xen_pv_printf(xendev, 0,
 170                       "xengnttab_map_domain_grant_refs failed: %s\n",
 171                       strerror(errno));
 172         g_free(refs);
 173         return -1;
 174     }
 175
 176     for (i = 0; i < nr_segs; i++) {
 177         XenGrantCopySegment *seg = &segs[i];
 178         void *page = pages + (i * XC_PAGE_SIZE);
 179
 180         if (to_domain) {
 181             memcpy(page + seg->dest.foreign.offset, seg->source.virt,
 182                    seg->len);
 183         } else {
 184             memcpy(seg->dest.virt, page + seg->source.foreign.offset,
 185                    seg->len);
 186         }
 187     }
 188
 189     if (xengnttab_unmap(xendev->gnttabdev, pages, nr_segs)) {
 190         xen_pv_printf(xendev, 0, "xengnttab_unmap failed: %s\n",
 191                       strerror(errno));
 192     }
 193
 194     g_free(refs);
 195     return 0;
 196 }
 197
 198 int xen_be_copy_grant_refs(struct XenDevice *xendev,
 199                            bool to_domain,
 200                            XenGrantCopySegment segs[],
 201                            unsigned int nr_segs)
 202 {
 203     xengnttab_grant_copy_segment_t *xengnttab_segs;
 204     unsigned int i;
 205     int rc;
 206
 207     assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV);
 208
 209     if (!xen_feature_grant_copy) {
 210         return compat_copy_grant_refs(xendev, to_domain, segs, nr_segs);
 211     }
 212
 213     xengnttab_segs = g_new0(xengnttab_grant_copy_segment_t, nr_segs);
 214
 215     for (i = 0; i < nr_segs; i++) {
 216         XenGrantCopySegment *seg = &segs[i];
 217         xengnttab_grant_copy_segment_t *xengnttab_seg = &xengnttab_segs[i];
 218
 219         if (to_domain) {
 220             xengnttab_seg->flags = GNTCOPY_dest_gref;
 221             xengnttab_seg->dest.foreign.domid = xen_domid;
 222             xengnttab_seg->dest.foreign.ref = seg->dest.foreign.ref;
 223             xengnttab_seg->dest.foreign.offset = seg->dest.foreign.offset;
 224             xengnttab_seg->source.virt = seg->source.virt;
 225         } else {
 226             xengnttab_seg->flags = GNTCOPY_source_gref;
 227             xengnttab_seg->source.foreign.domid = xen_domid;
 228             xengnttab_seg->source.foreign.ref = seg->source.foreign.ref;
 229             xengnttab_seg->source.foreign.offset =
 230                 seg->source.foreign.offset;
 231             xengnttab_seg->dest.virt = seg->dest.virt;
 232         }
 233
 234         xengnttab_seg->len = seg->len;
 235     }
 236
 237     rc = xengnttab_grant_copy(xendev->gnttabdev, nr_segs, xengnttab_segs);
 238
 239     if (rc) {
 240         xen_pv_printf(xendev, 0, "xengnttab_copy failed: %s\n",
 241                       strerror(errno));
 242     }
 243
 244     for (i = 0; i < nr_segs; i++) {
 245         xengnttab_grant_copy_segment_t *xengnttab_seg =
 246             &xengnttab_segs[i];
 247
 248         if (xengnttab_seg->status != GNTST_okay) {
 249             xen_pv_printf(xendev, 0, "segment[%u] status: %d\n", i,
 250                           xengnttab_seg->status);
 251             rc = -1;
 252         }
 253     }
 254
 255     g_free(xengnttab_segs);
 256     return rc;
 257 }
 258
 259 /*
 260  * get xen backend device, allocate a new one if it doesn't exist.
 261  */
 262 static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
 263                                            struct XenDevOps *ops)
 264 {
 265     struct XenDevice *xendev;
 266
 267     xendev = xen_pv_find_xendev(type, dom, dev);
 268     if (xendev) {
 269         return xendev;
 270     }
 271
 272     /* init new xendev */
 273     xendev = g_malloc0(ops->size);
 274     object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND);
 275     OBJECT(xendev)->free = g_free;
 276     qdev_set_parent_bus(DEVICE(xendev), xen_sysbus);
 277     qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev));
 278     qdev_init_nofail(DEVICE(xendev));
 279     object_unref(OBJECT(xendev));
 280
 281     xendev->type  = type;
 282     xendev->dom   = dom;
 283     xendev->dev   = dev;
 284     xendev->ops   = ops;
 285
 286     snprintf(xendev->be, sizeof(xendev->be), "backend/%s/%d/%d",
 287              xendev->type, xendev->dom, xendev->dev);
 288     snprintf(xendev->name, sizeof(xendev->name), "%s-%d",
 289              xendev->type, xendev->dev);
 290
 291     xendev->debug      = debug;
 292     xendev->local_port = -1;
 293
 294     xendev->evtchndev = xenevtchn_open(NULL, 0);
 295     if (xendev->evtchndev == NULL) {
 296         xen_pv_printf(NULL, 0, "can't open evtchn device\n");
 297         qdev_unplug(DEVICE(xendev), NULL);
 298         return NULL;
 299     }
 300     qemu_set_cloexec(xenevtchn_fd(xendev->evtchndev));
 301
 302     xen_pv_insert_xendev(xendev);
 303
 304     if (xendev->ops->alloc) {
 305         xendev->ops->alloc(xendev);
 306     }
 307
 308     return xendev;
 309 }
 310
 311
 312 /*
 313  * Sync internal data structures on xenstore updates.
 314  * Node specifies the changed field.  node = NULL means
 315  * update all fields (used for initialization).
 316  */
 317 static void xen_be_backend_changed(struct XenDevice *xendev, const char *node)
 318 {
 319     if (node == NULL  ||  strcmp(node, "online") == 0) {
 320         if (xenstore_read_be_int(xendev, "online", &xendev->online) == -1) {
 321             xendev->online = 0;
 322         }
 323     }
 324
 325     if (node) {
 326         xen_pv_printf(xendev, 2, "backend update: %s\n", node);
 327         if (xendev->ops->backend_changed) {
 328             xendev->ops->backend_changed(xendev, node);
 329         }
 330     }
 331 }
 332
 333 static void xen_be_frontend_changed(struct XenDevice *xendev, const char *node)
 334 {
 335     int fe_state;
 336
 337     if (node == NULL  ||  strcmp(node, "state") == 0) {
 338         if (xenstore_read_fe_int(xendev, "state", &fe_state) == -1) {
 339             fe_state = XenbusStateUnknown;
 340         }
 341         if (xendev->fe_state != fe_state) {
 342             xen_pv_printf(xendev, 1, "frontend state: %s -> %s\n",
 343                           xenbus_strstate(xendev->fe_state),
 344                           xenbus_strstate(fe_state));
 345         }
 346         xendev->fe_state = fe_state;
 347     }
 348     if (node == NULL  ||  strcmp(node, "protocol") == 0) {
 349         g_free(xendev->protocol);
 350         xendev->protocol = xenstore_read_fe_str(xendev, "protocol");
 351         if (xendev->protocol) {
 352             xen_pv_printf(xendev, 1, "frontend protocol: %s\n",
 353                           xendev->protocol);
 354         }
 355     }
 356
 357     if (node) {
 358         xen_pv_printf(xendev, 2, "frontend update: %s\n", node);
 359         if (xendev->ops->frontend_changed) {
 360             xendev->ops->frontend_changed(xendev, node);
 361         }
 362     }
 363 }
 364
 365 /* ------------------------------------------------------------- */
 366 /* Check for possible state transitions and perform them.        */
 367
 368 /*
 369  * Initial xendev setup.  Read frontend path, register watch for it.
 370  * Should succeed once xend finished setting up the backend device.
 371  *
 372  * Also sets initial state (-> Initializing) when done.  Which
 373  * only affects the xendev->be_state variable as xenbus should
 374  * already be put into that state by xend.
 375  */
 376 static int xen_be_try_setup(struct XenDevice *xendev)
 377 {
 378     char token[XEN_BUFSIZE];
 379     int be_state;
 380
 381     if (xenstore_read_be_int(xendev, "state", &be_state) == -1) {
 382         xen_pv_printf(xendev, 0, "reading backend state failed\n");
 383         return -1;
 384     }
 385
 386     if (be_state != XenbusStateInitialising) {
 387         xen_pv_printf(xendev, 0, "initial backend state is wrong (%s)\n",
 388                       xenbus_strstate(be_state));
 389         return -1;
 390     }
 391
 392     xendev->fe = xenstore_read_be_str(xendev, "frontend");
 393     if (xendev->fe == NULL) {
 394         xen_pv_printf(xendev, 0, "reading frontend path failed\n");
 395         return -1;
 396     }
 397
 398     /* setup frontend watch */
 399     snprintf(token, sizeof(token), "fe:%p", xendev);
 400     if (!xs_watch(xenstore, xendev->fe, token)) {
 401         xen_pv_printf(xendev, 0, "watching frontend path (%s) failed\n",
 402                       xendev->fe);
 403         return -1;
 404     }
 405     xen_be_set_state(xendev, XenbusStateInitialising);
 406
 407     xen_be_backend_changed(xendev, NULL);
 408     xen_be_frontend_changed(xendev, NULL);
 409     return 0;
 410 }
 411
 412 /*
 413  * Try initialize xendev.  Prepare everything the backend can do
 414  * without synchronizing with the frontend.  Fakes hotplug-status.  No
 415  * hotplug involved here because this is about userspace drivers, thus
 416  * there are kernel backend devices which could invoke hotplug.
 417  *
 418  * Goes to InitWait on success.
 419  */
 420 static int xen_be_try_init(struct XenDevice *xendev)
 421 {
 422     int rc = 0;
 423
 424     if (!xendev->online) {
 425         xen_pv_printf(xendev, 1, "not online\n");
 426         return -1;
 427     }
 428
 429     if (xendev->ops->init) {
 430         rc = xendev->ops->init(xendev);
 431     }
 432     if (rc != 0) {
 433         xen_pv_printf(xendev, 1, "init() failed\n");
 434         return rc;
 435     }
 436
 437     xenstore_write_be_str(xendev, "hotplug-status", "connected");
 438     xen_be_set_state(xendev, XenbusStateInitWait);
 439     return 0;
 440 }
 441
 442 /*
 443  * Try to initialise xendev.  Depends on the frontend being ready
 444  * for it (shared ring and evtchn info in xenstore, state being
 445  * Initialised or Connected).
 446  *
 447  * Goes to Connected on success.
 448  */
 449 static int xen_be_try_initialise(struct XenDevice *xendev)
 450 {
 451     int rc = 0;
 452
 453     if (xendev->fe_state != XenbusStateInitialised  &&
 454         xendev->fe_state != XenbusStateConnected) {
 455         if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
 456             xen_pv_printf(xendev, 2, "frontend not ready, ignoring\n");
 457         } else {
 458             xen_pv_printf(xendev, 2, "frontend not ready (yet)\n");
 459             return -1;
 460         }
 461     }
 462
 463     if (xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV) {
 464         xendev->gnttabdev = xengnttab_open(NULL, 0);
 465         if (xendev->gnttabdev == NULL) {
 466             xen_pv_printf(NULL, 0, "can't open gnttab device\n");
 467             return -1;
 468         }
 469     } else {
 470         xendev->gnttabdev = NULL;
 471     }
 472
 473     if (xendev->ops->initialise) {
 474         rc = xendev->ops->initialise(xendev);
 475     }
 476     if (rc != 0) {
 477         xen_pv_printf(xendev, 0, "initialise() failed\n");
 478         return rc;
 479     }
 480
 481     xen_be_set_state(xendev, XenbusStateConnected);
 482     return 0;
 483 }
 484
 485 /*
 486  * Try to let xendev know that it is connected.  Depends on the
 487  * frontend being Connected.  Note that this may be called more
 488  * than once since the backend state is not modified.
 489  */
 490 static void xen_be_try_connected(struct XenDevice *xendev)
 491 {
 492     if (!xendev->ops->connected) {
 493         return;
 494     }
 495
 496     if (xendev->fe_state != XenbusStateConnected) {
 497         if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
 498             xen_pv_printf(xendev, 2, "frontend not ready, ignoring\n");
 499         } else {
 500             xen_pv_printf(xendev, 2, "frontend not ready (yet)\n");
 501             return;
 502         }
 503     }
 504
 505     xendev->ops->connected(xendev);
 506 }
 507
 508 /*
 509  * Teardown connection.
 510  *
 511  * Goes to Closed when done.
 512  */
 513 static void xen_be_disconnect(struct XenDevice *xendev, enum xenbus_state state)
 514 {
 515     if (xendev->be_state != XenbusStateClosing &&
 516         xendev->be_state != XenbusStateClosed  &&
 517         xendev->ops->disconnect) {
 518         xendev->ops->disconnect(xendev);
 519     }
 520     if (xendev->gnttabdev) {
 521         xengnttab_close(xendev->gnttabdev);
 522         xendev->gnttabdev = NULL;
 523     }
 524     if (xendev->be_state != state) {
 525         xen_be_set_state(xendev, state);
 526     }
 527 }
 528
 529 /*
 530  * Try to reset xendev, for reconnection by another frontend instance.
 531  */
 532 static int xen_be_try_reset(struct XenDevice *xendev)
 533 {
 534     if (xendev->fe_state != XenbusStateInitialising) {
 535         return -1;
 536     }
 537
 538     xen_pv_printf(xendev, 1, "device reset (for re-connect)\n");
 539     xen_be_set_state(xendev, XenbusStateInitialising);
 540     return 0;
 541 }
 542
 543 /*
 544  * state change dispatcher function
 545  */
 546 void xen_be_check_state(struct XenDevice *xendev)
 547 {
 548     int rc = 0;
 549
 550     /* frontend may request shutdown from almost anywhere */
 551     if (xendev->fe_state == XenbusStateClosing ||
 552         xendev->fe_state == XenbusStateClosed) {
 553         xen_be_disconnect(xendev, xendev->fe_state);
 554         return;
 555     }
 556
 557     /* check for possible backend state transitions */
 558     for (;;) {
 559         switch (xendev->be_state) {
 560         case XenbusStateUnknown:
 561             rc = xen_be_try_setup(xendev);
 562             break;
 563         case XenbusStateInitialising:
 564             rc = xen_be_try_init(xendev);
 565             break;
 566         case XenbusStateInitWait:
 567             rc = xen_be_try_initialise(xendev);
 568             break;
 569         case XenbusStateConnected:
 570             /* xendev->be_state doesn't change */
 571             xen_be_try_connected(xendev);
 572             rc = -1;
 573             break;
 574         case XenbusStateClosed:
 575             rc = xen_be_try_reset(xendev);
 576             break;
 577         default:
 578             rc = -1;
 579         }
 580         if (rc != 0) {
 581             break;
 582         }
 583     }
 584 }
 585
 586 /* ------------------------------------------------------------- */
 587
 588 static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
 589 {
 590     struct XenDevice *xendev;
 591     char path[XEN_BUFSIZE], token[XEN_BUFSIZE];
 592     char **dev = NULL;
 593     unsigned int cdev, j;
 594
 595     /* setup watch */
 596     snprintf(token, sizeof(token), "be:%p:%d:%p", type, dom, ops);
 597     snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
 598     if (!xs_watch(xenstore, path, token)) {
 599         xen_pv_printf(NULL, 0, "xen be: watching backend path (%s) failed\n",
 600                       path);
 601         return -1;
 602     }
 603
 604     /* look for backends */
 605     dev = xs_directory(xenstore, 0, path, &cdev);
 606     if (!dev) {
 607         return 0;
 608     }
 609     for (j = 0; j < cdev; j++) {
 610         xendev = xen_be_get_xendev(type, dom, atoi(dev[j]), ops);
 611         if (xendev == NULL) {
 612             continue;
 613         }
 614         xen_be_check_state(xendev);
 615     }
 616     free(dev);
 617     return 0;
 618 }
 619
 620 void xenstore_update_be(char *watch, char *type, int dom,
 621                         struct XenDevOps *ops)
 622 {
 623     struct XenDevice *xendev;
 624     char path[XEN_BUFSIZE], *bepath;
 625     unsigned int len, dev;
 626
 627     len = snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
 628     if (strncmp(path, watch, len) != 0) {
 629         return;
 630     }
 631     if (sscanf(watch+len, "/%u/%255s", &dev, path) != 2) {
 632         strcpy(path, "");
 633         if (sscanf(watch+len, "/%u", &dev) != 1) {
 634             dev = -1;
 635         }
 636     }
 637     if (dev == -1) {
 638         return;
 639     }
 640
 641     xendev = xen_be_get_xendev(type, dom, dev, ops);
 642     if (xendev != NULL) {
 643         bepath = xs_read(xenstore, 0, xendev->be, &len);
 644         if (bepath == NULL) {
 645             xen_pv_del_xendev(xendev);
 646         } else {
 647             free(bepath);
 648             xen_be_backend_changed(xendev, path);
 649             xen_be_check_state(xendev);
 650         }
 651     }
 652 }
 653
 654 void xenstore_update_fe(char *watch, struct XenDevice *xendev)
 655 {
 656     char *node;
 657     unsigned int len;
 658
 659     len = strlen(xendev->fe);
 660     if (strncmp(xendev->fe, watch, len) != 0) {
 661         return;
 662     }
 663     if (watch[len] != '/') {
 664         return;
 665     }
 666     node = watch + len + 1;
 667
 668     xen_be_frontend_changed(xendev, node);
 669     xen_be_check_state(xendev);
 670 }
 671 /* -------------------------------------------------------------------- */
 672
 673 int xen_be_init(void)
 674 {
 675     xengnttab_handle *gnttabdev;
 676
 677     xenstore = xs_daemon_open();
 678     if (!xenstore) {
 679         xen_pv_printf(NULL, 0, "can't connect to xenstored\n");
 680         return -1;
 681     }
 682
 683     qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL);
 684
 685     if (xen_xc == NULL || xen_fmem == NULL) {
 686         /* Check if xen_init() have been called */
 687         goto err;
 688     }
 689
 690     gnttabdev = xengnttab_open(NULL, 0);
 691     if (gnttabdev != NULL) {
 692         if (xengnttab_grant_copy(gnttabdev, 0, NULL) == 0) {
 693             xen_feature_grant_copy = true;
 694         }
 695         xengnttab_close(gnttabdev);
 696     }
 697
 698     xen_sysdev = qdev_create(NULL, TYPE_XENSYSDEV);
 699     qdev_init_nofail(xen_sysdev);
 700     xen_sysbus = qbus_create(TYPE_XENSYSBUS, DEVICE(xen_sysdev), "xen-sysbus");
 701     qbus_set_bus_hotplug_handler(xen_sysbus, &error_abort);
 702
 703     return 0;
 704
 705 err:
 706     qemu_set_fd_handler(xs_fileno(xenstore), NULL, NULL, NULL);
 707     xs_daemon_close(xenstore);
 708     xenstore = NULL;
 709
 710     return -1;
 711 }
 712
 713 static void xen_set_dynamic_sysbus(void)
 714 {
 715     Object *machine = qdev_get_machine();
 716     ObjectClass *oc = object_get_class(machine);
 717     MachineClass *mc = MACHINE_CLASS(oc);
 718
 719     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_XENSYSDEV);
 720 }
 721
 722 int xen_be_register(const char *type, struct XenDevOps *ops)
 723 {
 724     char path[50];
 725     int rc;
 726
 727     if (ops->backend_register) {
 728         rc = ops->backend_register();
 729         if (rc) {
 730             return rc;
 731         }
 732     }
 733
 734     snprintf(path, sizeof(path), "device-model/%u/backends/%s", xen_domid,
 735              type);
 736     xenstore_mkdir(path, XS_PERM_NONE);
 737
 738     return xenstore_scan(type, xen_domid, ops);
 739 }
 740
 741 void xen_be_register_common(void)
 742 {
 743     xen_set_dynamic_sysbus();
 744
 745     xen_be_register("console", &xen_console_ops);
 746     xen_be_register("vkbd", &xen_kbdmouse_ops);
 747     xen_be_register("qdisk", &xen_blkdev_ops);
 748 #ifdef CONFIG_VIRTFS
 749     xen_be_register("9pfs", &xen_9pfs_ops);
 750 #endif
 751 #ifdef CONFIG_USB_LIBUSB
 752     xen_be_register("qusb", &xen_usb_ops);
 753 #endif
 754 }
 755
 756 int xen_be_bind_evtchn(struct XenDevice *xendev)
 757 {
 758     if (xendev->local_port != -1) {
 759         return 0;
 760     }
 761     xendev->local_port = xenevtchn_bind_interdomain
 762         (xendev->evtchndev, xendev->dom, xendev->remote_port);
 763     if (xendev->local_port == -1) {
 764         xen_pv_printf(xendev, 0, "xenevtchn_bind_interdomain failed\n");
 765         return -1;
 766     }
 767     xen_pv_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
 768     qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev),
 769                         xen_pv_evtchn_event, NULL, xendev);
 770     return 0;
 771 }
 772
 773
 774 static Property xendev_properties[] = {
 775     DEFINE_PROP_END_OF_LIST(),
 776 };
 777
 778 static void xendev_class_init(ObjectClass *klass, void *data)
 779 {
 780     DeviceClass *dc = DEVICE_CLASS(klass);
 781
 782     dc->props = xendev_properties;
 783     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 784     /* xen-backend devices can be plugged/unplugged dynamically */
 785     dc->user_creatable = true;
 786 }
 787
 788 static const TypeInfo xendev_type_info = {
 789     .name          = TYPE_XENBACKEND,
 790     .parent        = TYPE_XENSYSDEV,
 791     .class_init    = xendev_class_init,
 792     .instance_size = sizeof(struct XenDevice),
 793 };
 794
 795 static void xen_sysbus_class_init(ObjectClass *klass, void *data)
 796 {
 797     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 798
 799     hc->unplug = qdev_simple_device_unplug_cb;
 800 }
 801
 802 static const TypeInfo xensysbus_info = {
 803     .name       = TYPE_XENSYSBUS,
 804     .parent     = TYPE_BUS,
 805     .class_init = xen_sysbus_class_init,
 806     .interfaces = (InterfaceInfo[]) {
 807         { TYPE_HOTPLUG_HANDLER },
 808         { }
 809     }
 810 };
 811
 812 static Property xen_sysdev_properties[] = {
 813     {/* end of property list */},
 814 };
 815
 816 static void xen_sysdev_class_init(ObjectClass *klass, void *data)
 817 {
 818     DeviceClass *dc = DEVICE_CLASS(klass);
 819
 820     dc->props = xen_sysdev_properties;
 821     dc->bus_type = TYPE_XENSYSBUS;
 822 }
 823
 824 static const TypeInfo xensysdev_info = {
 825     .name          = TYPE_XENSYSDEV,
 826     .parent        = TYPE_SYS_BUS_DEVICE,
 827     .instance_size = sizeof(SysBusDevice),
 828     .class_init    = xen_sysdev_class_init,
 829 };
 830
 831 static void xenbe_register_types(void)
 832 {
 833     type_register_static(&xensysbus_info);
 834     type_register_static(&xensysdev_info);
 835     type_register_static(&xendev_type_info);
 836 }
 837
 838 type_init(xenbe_register_types)