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
  34 #include <xen/grant_table.h>
  35
  36 #define TYPE_XENSYSDEV "xensysdev"
  37
  38 DeviceState *xen_sysdev;
  39
  40 /* ------------------------------------------------------------- */
  41
  42 /* public */
  43 xc_interface *xen_xc = NULL;
  44 xenforeignmemory_handle *xen_fmem = NULL;
  45 struct xs_handle *xenstore = NULL;
  46 const char *xen_protocol;
  47
  48 /* private */
  49 struct xs_dirs {
  50     char *xs_dir;
  51     QTAILQ_ENTRY(xs_dirs) list;
  52 };
  53 static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup =
  54     QTAILQ_HEAD_INITIALIZER(xs_cleanup);
  55
  56 static QTAILQ_HEAD(XenDeviceHead, XenDevice) xendevs = QTAILQ_HEAD_INITIALIZER(xendevs);
  57 static int debug = 0;
  58
  59 /* ------------------------------------------------------------- */
  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_write_str(const char *base, const char *node, const char *val)
  80 {
  81     char abspath[XEN_BUFSIZE];
  82
  83     snprintf(abspath, sizeof(abspath), "%s/%s", base, node);
  84     if (!xs_write(xenstore, 0, abspath, val, strlen(val))) {
  85         return -1;
  86     }
  87     return 0;
  88 }
  89
  90 char *xenstore_read_str(const char *base, const char *node)
  91 {
  92     char abspath[XEN_BUFSIZE];
  93     unsigned int len;
  94     char *str, *ret = NULL;
  95
  96     snprintf(abspath, sizeof(abspath), "%s/%s", base, node);
  97     str = xs_read(xenstore, 0, abspath, &len);
  98     if (str != NULL) {
  99         /* move to qemu-allocated memory to make sure
 100          * callers can savely g_free() stuff. */
 101         ret = g_strdup(str);
 102         free(str);
 103     }
 104     return ret;
 105 }
 106
 107 int xenstore_mkdir(char *path, int p)
 108 {
 109     struct xs_permissions perms[2] = {
 110         {
 111             .id    = 0, /* set owner: dom0 */
 112         }, {
 113             .id    = xen_domid,
 114             .perms = p,
 115         }
 116     };
 117
 118     if (!xs_mkdir(xenstore, 0, path)) {
 119         xen_be_printf(NULL, 0, "xs_mkdir %s: failed\n", path);
 120         return -1;
 121     }
 122     xenstore_cleanup_dir(g_strdup(path));
 123
 124     if (!xs_set_permissions(xenstore, 0, path, perms, 2)) {
 125         xen_be_printf(NULL, 0, "xs_set_permissions %s: failed\n", path);
 126         return -1;
 127     }
 128     return 0;
 129 }
 130
 131 int xenstore_write_int(const char *base, const char *node, int ival)
 132 {
 133     char val[12];
 134
 135     snprintf(val, sizeof(val), "%d", ival);
 136     return xenstore_write_str(base, node, val);
 137 }
 138
 139 int xenstore_write_int64(const char *base, const char *node, int64_t ival)
 140 {
 141     char val[21];
 142
 143     snprintf(val, sizeof(val), "%"PRId64, ival);
 144     return xenstore_write_str(base, node, val);
 145 }
 146
 147 int xenstore_read_int(const char *base, const char *node, int *ival)
 148 {
 149     char *val;
 150     int rc = -1;
 151
 152     val = xenstore_read_str(base, node);
 153     if (val && 1 == sscanf(val, "%d", ival)) {
 154         rc = 0;
 155     }
 156     g_free(val);
 157     return rc;
 158 }
 159
 160 int xenstore_read_uint64(const char *base, const char *node, uint64_t *uval)
 161 {
 162     char *val;
 163     int rc = -1;
 164
 165     val = xenstore_read_str(base, node);
 166     if (val && 1 == sscanf(val, "%"SCNu64, uval)) {
 167         rc = 0;
 168     }
 169     g_free(val);
 170     return rc;
 171 }
 172
 173 int xenstore_write_be_str(struct XenDevice *xendev, const char *node, const char *val)
 174 {
 175     return xenstore_write_str(xendev->be, node, val);
 176 }
 177
 178 int xenstore_write_be_int(struct XenDevice *xendev, const char *node, int ival)
 179 {
 180     return xenstore_write_int(xendev->be, node, ival);
 181 }
 182
 183 int xenstore_write_be_int64(struct XenDevice *xendev, const char *node, int64_t ival)
 184 {
 185     return xenstore_write_int64(xendev->be, node, ival);
 186 }
 187
 188 char *xenstore_read_be_str(struct XenDevice *xendev, const char *node)
 189 {
 190     return xenstore_read_str(xendev->be, node);
 191 }
 192
 193 int xenstore_read_be_int(struct XenDevice *xendev, const char *node, int *ival)
 194 {
 195     return xenstore_read_int(xendev->be, node, ival);
 196 }
 197
 198 char *xenstore_read_fe_str(struct XenDevice *xendev, const char *node)
 199 {
 200     return xenstore_read_str(xendev->fe, node);
 201 }
 202
 203 int xenstore_read_fe_int(struct XenDevice *xendev, const char *node, int *ival)
 204 {
 205     return xenstore_read_int(xendev->fe, node, ival);
 206 }
 207
 208 int xenstore_read_fe_uint64(struct XenDevice *xendev, const char *node, uint64_t *uval)
 209 {
 210     return xenstore_read_uint64(xendev->fe, node, uval);
 211 }
 212
 213 /* ------------------------------------------------------------- */
 214
 215 const char *xenbus_strstate(enum xenbus_state state)
 216 {
 217     static const char *const name[] = {
 218         [ XenbusStateUnknown      ] = "Unknown",
 219         [ XenbusStateInitialising ] = "Initialising",
 220         [ XenbusStateInitWait     ] = "InitWait",
 221         [ XenbusStateInitialised  ] = "Initialised",
 222         [ XenbusStateConnected    ] = "Connected",
 223         [ XenbusStateClosing      ] = "Closing",
 224         [ XenbusStateClosed       ] = "Closed",
 225     };
 226     return (state < ARRAY_SIZE(name)) ? name[state] : "INVALID";
 227 }
 228
 229 int xen_be_set_state(struct XenDevice *xendev, enum xenbus_state state)
 230 {
 231     int rc;
 232
 233     rc = xenstore_write_be_int(xendev, "state", state);
 234     if (rc < 0) {
 235         return rc;
 236     }
 237     xen_be_printf(xendev, 1, "backend state: %s -> %s\n",
 238                   xenbus_strstate(xendev->be_state), xenbus_strstate(state));
 239     xendev->be_state = state;
 240     return 0;
 241 }
 242
 243 /* ------------------------------------------------------------- */
 244
 245 struct XenDevice *xen_be_find_xendev(const char *type, int dom, int dev)
 246 {
 247     struct XenDevice *xendev;
 248
 249     QTAILQ_FOREACH(xendev, &xendevs, next) {
 250         if (xendev->dom != dom) {
 251             continue;
 252         }
 253         if (xendev->dev != dev) {
 254             continue;
 255         }
 256         if (strcmp(xendev->type, type) != 0) {
 257             continue;
 258         }
 259         return xendev;
 260     }
 261     return NULL;
 262 }
 263
 264 /*
 265  * get xen backend device, allocate a new one if it doesn't exist.
 266  */
 267 static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
 268                                            struct XenDevOps *ops)
 269 {
 270     struct XenDevice *xendev;
 271
 272     xendev = xen_be_find_xendev(type, dom, dev);
 273     if (xendev) {
 274         return xendev;
 275     }
 276
 277     /* init new xendev */
 278     xendev = g_malloc0(ops->size);
 279     xendev->type  = type;
 280     xendev->dom   = dom;
 281     xendev->dev   = dev;
 282     xendev->ops   = ops;
 283
 284     snprintf(xendev->be, sizeof(xendev->be), "backend/%s/%d/%d",
 285              xendev->type, xendev->dom, xendev->dev);
 286     snprintf(xendev->name, sizeof(xendev->name), "%s-%d",
 287              xendev->type, xendev->dev);
 288
 289     xendev->debug      = debug;
 290     xendev->local_port = -1;
 291
 292     xendev->evtchndev = xenevtchn_open(NULL, 0);
 293     if (xendev->evtchndev == NULL) {
 294         xen_be_printf(NULL, 0, "can't open evtchn device\n");
 295         g_free(xendev);
 296         return NULL;
 297     }
 298     fcntl(xenevtchn_fd(xendev->evtchndev), F_SETFD, FD_CLOEXEC);
 299
 300     if (ops->flags & DEVOPS_FLAG_NEED_GNTDEV) {
 301         xendev->gnttabdev = xengnttab_open(NULL, 0);
 302         if (xendev->gnttabdev == NULL) {
 303             xen_be_printf(NULL, 0, "can't open gnttab device\n");
 304             xenevtchn_close(xendev->evtchndev);
 305             g_free(xendev);
 306             return NULL;
 307         }
 308     } else {
 309         xendev->gnttabdev = NULL;
 310     }
 311
 312     QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
 313
 314     if (xendev->ops->alloc) {
 315         xendev->ops->alloc(xendev);
 316     }
 317
 318     return xendev;
 319 }
 320
 321 /*
 322  * release xen backend device.
 323  */
 324 static void xen_be_del_xendev(struct XenDevice *xendev)
 325 {
 326     if (xendev->ops->free) {
 327         xendev->ops->free(xendev);
 328     }
 329
 330     if (xendev->fe) {
 331         char token[XEN_BUFSIZE];
 332         snprintf(token, sizeof(token), "fe:%p", xendev);
 333         xs_unwatch(xenstore, xendev->fe, token);
 334         g_free(xendev->fe);
 335     }
 336
 337     if (xendev->evtchndev != NULL) {
 338         xenevtchn_close(xendev->evtchndev);
 339     }
 340     if (xendev->gnttabdev != NULL) {
 341         xengnttab_close(xendev->gnttabdev);
 342     }
 343
 344     QTAILQ_REMOVE(&xendevs, xendev, next);
 345     g_free(xendev);
 346 }
 347
 348 /*
 349  * Sync internal data structures on xenstore updates.
 350  * Node specifies the changed field.  node = NULL means
 351  * update all fields (used for initialization).
 352  */
 353 static void xen_be_backend_changed(struct XenDevice *xendev, const char *node)
 354 {
 355     if (node == NULL  ||  strcmp(node, "online") == 0) {
 356         if (xenstore_read_be_int(xendev, "online", &xendev->online) == -1) {
 357             xendev->online = 0;
 358         }
 359     }
 360
 361     if (node) {
 362         xen_be_printf(xendev, 2, "backend update: %s\n", node);
 363         if (xendev->ops->backend_changed) {
 364             xendev->ops->backend_changed(xendev, node);
 365         }
 366     }
 367 }
 368
 369 static void xen_be_frontend_changed(struct XenDevice *xendev, const char *node)
 370 {
 371     int fe_state;
 372
 373     if (node == NULL  ||  strcmp(node, "state") == 0) {
 374         if (xenstore_read_fe_int(xendev, "state", &fe_state) == -1) {
 375             fe_state = XenbusStateUnknown;
 376         }
 377         if (xendev->fe_state != fe_state) {
 378             xen_be_printf(xendev, 1, "frontend state: %s -> %s\n",
 379                           xenbus_strstate(xendev->fe_state),
 380                           xenbus_strstate(fe_state));
 381         }
 382         xendev->fe_state = fe_state;
 383     }
 384     if (node == NULL  ||  strcmp(node, "protocol") == 0) {
 385         g_free(xendev->protocol);
 386         xendev->protocol = xenstore_read_fe_str(xendev, "protocol");
 387         if (xendev->protocol) {
 388             xen_be_printf(xendev, 1, "frontend protocol: %s\n", xendev->protocol);
 389         }
 390     }
 391
 392     if (node) {
 393         xen_be_printf(xendev, 2, "frontend update: %s\n", node);
 394         if (xendev->ops->frontend_changed) {
 395             xendev->ops->frontend_changed(xendev, node);
 396         }
 397     }
 398 }
 399
 400 /* ------------------------------------------------------------- */
 401 /* Check for possible state transitions and perform them.        */
 402
 403 /*
 404  * Initial xendev setup.  Read frontend path, register watch for it.
 405  * Should succeed once xend finished setting up the backend device.
 406  *
 407  * Also sets initial state (-> Initializing) when done.  Which
 408  * only affects the xendev->be_state variable as xenbus should
 409  * already be put into that state by xend.
 410  */
 411 static int xen_be_try_setup(struct XenDevice *xendev)
 412 {
 413     char token[XEN_BUFSIZE];
 414     int be_state;
 415
 416     if (xenstore_read_be_int(xendev, "state", &be_state) == -1) {
 417         xen_be_printf(xendev, 0, "reading backend state failed\n");
 418         return -1;
 419     }
 420
 421     if (be_state != XenbusStateInitialising) {
 422         xen_be_printf(xendev, 0, "initial backend state is wrong (%s)\n",
 423                       xenbus_strstate(be_state));
 424         return -1;
 425     }
 426
 427     xendev->fe = xenstore_read_be_str(xendev, "frontend");
 428     if (xendev->fe == NULL) {
 429         xen_be_printf(xendev, 0, "reading frontend path failed\n");
 430         return -1;
 431     }
 432
 433     /* setup frontend watch */
 434     snprintf(token, sizeof(token), "fe:%p", xendev);
 435     if (!xs_watch(xenstore, xendev->fe, token)) {
 436         xen_be_printf(xendev, 0, "watching frontend path (%s) failed\n",
 437                       xendev->fe);
 438         return -1;
 439     }
 440     xen_be_set_state(xendev, XenbusStateInitialising);
 441
 442     xen_be_backend_changed(xendev, NULL);
 443     xen_be_frontend_changed(xendev, NULL);
 444     return 0;
 445 }
 446
 447 /*
 448  * Try initialize xendev.  Prepare everything the backend can do
 449  * without synchronizing with the frontend.  Fakes hotplug-status.  No
 450  * hotplug involved here because this is about userspace drivers, thus
 451  * there are kernel backend devices which could invoke hotplug.
 452  *
 453  * Goes to InitWait on success.
 454  */
 455 static int xen_be_try_init(struct XenDevice *xendev)
 456 {
 457     int rc = 0;
 458
 459     if (!xendev->online) {
 460         xen_be_printf(xendev, 1, "not online\n");
 461         return -1;
 462     }
 463
 464     if (xendev->ops->init) {
 465         rc = xendev->ops->init(xendev);
 466     }
 467     if (rc != 0) {
 468         xen_be_printf(xendev, 1, "init() failed\n");
 469         return rc;
 470     }
 471
 472     xenstore_write_be_str(xendev, "hotplug-status", "connected");
 473     xen_be_set_state(xendev, XenbusStateInitWait);
 474     return 0;
 475 }
 476
 477 /*
 478  * Try to initialise xendev.  Depends on the frontend being ready
 479  * for it (shared ring and evtchn info in xenstore, state being
 480  * Initialised or Connected).
 481  *
 482  * Goes to Connected on success.
 483  */
 484 static int xen_be_try_initialise(struct XenDevice *xendev)
 485 {
 486     int rc = 0;
 487
 488     if (xendev->fe_state != XenbusStateInitialised  &&
 489         xendev->fe_state != XenbusStateConnected) {
 490         if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
 491             xen_be_printf(xendev, 2, "frontend not ready, ignoring\n");
 492         } else {
 493             xen_be_printf(xendev, 2, "frontend not ready (yet)\n");
 494             return -1;
 495         }
 496     }
 497
 498     if (xendev->ops->initialise) {
 499         rc = xendev->ops->initialise(xendev);
 500     }
 501     if (rc != 0) {
 502         xen_be_printf(xendev, 0, "initialise() failed\n");
 503         return rc;
 504     }
 505
 506     xen_be_set_state(xendev, XenbusStateConnected);
 507     return 0;
 508 }
 509
 510 /*
 511  * Try to let xendev know that it is connected.  Depends on the
 512  * frontend being Connected.  Note that this may be called more
 513  * than once since the backend state is not modified.
 514  */
 515 static void xen_be_try_connected(struct XenDevice *xendev)
 516 {
 517     if (!xendev->ops->connected) {
 518         return;
 519     }
 520
 521     if (xendev->fe_state != XenbusStateConnected) {
 522         if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
 523             xen_be_printf(xendev, 2, "frontend not ready, ignoring\n");
 524         } else {
 525             xen_be_printf(xendev, 2, "frontend not ready (yet)\n");
 526             return;
 527         }
 528     }
 529
 530     xendev->ops->connected(xendev);
 531 }
 532
 533 /*
 534  * Teardown connection.
 535  *
 536  * Goes to Closed when done.
 537  */
 538 static void xen_be_disconnect(struct XenDevice *xendev, enum xenbus_state state)
 539 {
 540     if (xendev->be_state != XenbusStateClosing &&
 541         xendev->be_state != XenbusStateClosed  &&
 542         xendev->ops->disconnect) {
 543         xendev->ops->disconnect(xendev);
 544     }
 545     if (xendev->be_state != state) {
 546         xen_be_set_state(xendev, state);
 547     }
 548 }
 549
 550 /*
 551  * Try to reset xendev, for reconnection by another frontend instance.
 552  */
 553 static int xen_be_try_reset(struct XenDevice *xendev)
 554 {
 555     if (xendev->fe_state != XenbusStateInitialising) {
 556         return -1;
 557     }
 558
 559     xen_be_printf(xendev, 1, "device reset (for re-connect)\n");
 560     xen_be_set_state(xendev, XenbusStateInitialising);
 561     return 0;
 562 }
 563
 564 /*
 565  * state change dispatcher function
 566  */
 567 void xen_be_check_state(struct XenDevice *xendev)
 568 {
 569     int rc = 0;
 570
 571     /* frontend may request shutdown from almost anywhere */
 572     if (xendev->fe_state == XenbusStateClosing ||
 573         xendev->fe_state == XenbusStateClosed) {
 574         xen_be_disconnect(xendev, xendev->fe_state);
 575         return;
 576     }
 577
 578     /* check for possible backend state transitions */
 579     for (;;) {
 580         switch (xendev->be_state) {
 581         case XenbusStateUnknown:
 582             rc = xen_be_try_setup(xendev);
 583             break;
 584         case XenbusStateInitialising:
 585             rc = xen_be_try_init(xendev);
 586             break;
 587         case XenbusStateInitWait:
 588             rc = xen_be_try_initialise(xendev);
 589             break;
 590         case XenbusStateConnected:
 591             /* xendev->be_state doesn't change */
 592             xen_be_try_connected(xendev);
 593             rc = -1;
 594             break;
 595         case XenbusStateClosed:
 596             rc = xen_be_try_reset(xendev);
 597             break;
 598         default:
 599             rc = -1;
 600         }
 601         if (rc != 0) {
 602             break;
 603         }
 604     }
 605 }
 606
 607 /* ------------------------------------------------------------- */
 608
 609 static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
 610 {
 611     struct XenDevice *xendev;
 612     char path[XEN_BUFSIZE], token[XEN_BUFSIZE];
 613     char **dev = NULL;
 614     unsigned int cdev, j;
 615
 616     /* setup watch */
 617     snprintf(token, sizeof(token), "be:%p:%d:%p", type, dom, ops);
 618     snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
 619     if (!xs_watch(xenstore, path, token)) {
 620         xen_be_printf(NULL, 0, "xen be: watching backend path (%s) failed\n", path);
 621         return -1;
 622     }
 623
 624     /* look for backends */
 625     dev = xs_directory(xenstore, 0, path, &cdev);
 626     if (!dev) {
 627         return 0;
 628     }
 629     for (j = 0; j < cdev; j++) {
 630         xendev = xen_be_get_xendev(type, dom, atoi(dev[j]), ops);
 631         if (xendev == NULL) {
 632             continue;
 633         }
 634         xen_be_check_state(xendev);
 635     }
 636     free(dev);
 637     return 0;
 638 }
 639
 640 static void xenstore_update_be(char *watch, char *type, int dom,
 641                                struct XenDevOps *ops)
 642 {
 643     struct XenDevice *xendev;
 644     char path[XEN_BUFSIZE], *bepath;
 645     unsigned int len, dev;
 646
 647     len = snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
 648     if (strncmp(path, watch, len) != 0) {
 649         return;
 650     }
 651     if (sscanf(watch+len, "/%u/%255s", &dev, path) != 2) {
 652         strcpy(path, "");
 653         if (sscanf(watch+len, "/%u", &dev) != 1) {
 654             dev = -1;
 655         }
 656     }
 657     if (dev == -1) {
 658         return;
 659     }
 660
 661     xendev = xen_be_get_xendev(type, dom, dev, ops);
 662     if (xendev != NULL) {
 663         bepath = xs_read(xenstore, 0, xendev->be, &len);
 664         if (bepath == NULL) {
 665             xen_be_del_xendev(xendev);
 666         } else {
 667             free(bepath);
 668             xen_be_backend_changed(xendev, path);
 669             xen_be_check_state(xendev);
 670         }
 671     }
 672 }
 673
 674 static void xenstore_update_fe(char *watch, struct XenDevice *xendev)
 675 {
 676     char *node;
 677     unsigned int len;
 678
 679     len = strlen(xendev->fe);
 680     if (strncmp(xendev->fe, watch, len) != 0) {
 681         return;
 682     }
 683     if (watch[len] != '/') {
 684         return;
 685     }
 686     node = watch + len + 1;
 687
 688     xen_be_frontend_changed(xendev, node);
 689     xen_be_check_state(xendev);
 690 }
 691
 692 static void xenstore_update(void *unused)
 693 {
 694     char **vec = NULL;
 695     intptr_t type, ops, ptr;
 696     unsigned int dom, count;
 697
 698     vec = xs_read_watch(xenstore, &count);
 699     if (vec == NULL) {
 700         goto cleanup;
 701     }
 702
 703     if (sscanf(vec[XS_WATCH_TOKEN], "be:%" PRIxPTR ":%d:%" PRIxPTR,
 704                &type, &dom, &ops) == 3) {
 705         xenstore_update_be(vec[XS_WATCH_PATH], (void*)type, dom, (void*)ops);
 706     }
 707     if (sscanf(vec[XS_WATCH_TOKEN], "fe:%" PRIxPTR, &ptr) == 1) {
 708         xenstore_update_fe(vec[XS_WATCH_PATH], (void*)ptr);
 709     }
 710
 711 cleanup:
 712     free(vec);
 713 }
 714
 715 static void xen_be_evtchn_event(void *opaque)
 716 {
 717     struct XenDevice *xendev = opaque;
 718     evtchn_port_t port;
 719
 720     port = xenevtchn_pending(xendev->evtchndev);
 721     if (port != xendev->local_port) {
 722         xen_be_printf(xendev, 0,
 723                       "xenevtchn_pending returned %d (expected %d)\n",
 724                       port, xendev->local_port);
 725         return;
 726     }
 727     xenevtchn_unmask(xendev->evtchndev, port);
 728
 729     if (xendev->ops->event) {
 730         xendev->ops->event(xendev);
 731     }
 732 }
 733
 734 /* -------------------------------------------------------------------- */
 735
 736 int xen_be_init(void)
 737 {
 738     xenstore = xs_daemon_open();
 739     if (!xenstore) {
 740         xen_be_printf(NULL, 0, "can't connect to xenstored\n");
 741         return -1;
 742     }
 743
 744     qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL);
 745
 746     if (xen_xc == NULL || xen_fmem == NULL) {
 747         /* Check if xen_init() have been called */
 748         goto err;
 749     }
 750
 751     xen_sysdev = qdev_create(NULL, TYPE_XENSYSDEV);
 752     qdev_init_nofail(xen_sysdev);
 753
 754     return 0;
 755
 756 err:
 757     qemu_set_fd_handler(xs_fileno(xenstore), NULL, NULL, NULL);
 758     xs_daemon_close(xenstore);
 759     xenstore = NULL;
 760
 761     return -1;
 762 }
 763
 764 int xen_be_register(const char *type, struct XenDevOps *ops)
 765 {
 766     char path[50];
 767     int rc;
 768
 769     if (ops->backend_register) {
 770         rc = ops->backend_register();
 771         if (rc) {
 772             return rc;
 773         }
 774     }
 775
 776     snprintf(path, sizeof(path), "device-model/%u/backends/%s", xen_domid,
 777              type);
 778     xenstore_mkdir(path, XS_PERM_NONE);
 779
 780     return xenstore_scan(type, xen_domid, ops);
 781 }
 782
 783 void xen_be_register_common(void)
 784 {
 785     xen_be_register("console", &xen_console_ops);
 786     xen_be_register("vkbd", &xen_kbdmouse_ops);
 787     xen_be_register("qdisk", &xen_blkdev_ops);
 788 #ifdef CONFIG_USB_LIBUSB
 789     xen_be_register("qusb", &xen_usb_ops);
 790 #endif
 791 }
 792
 793 int xen_be_bind_evtchn(struct XenDevice *xendev)
 794 {
 795     if (xendev->local_port != -1) {
 796         return 0;
 797     }
 798     xendev->local_port = xenevtchn_bind_interdomain
 799         (xendev->evtchndev, xendev->dom, xendev->remote_port);
 800     if (xendev->local_port == -1) {
 801         xen_be_printf(xendev, 0, "xenevtchn_bind_interdomain failed\n");
 802         return -1;
 803     }
 804     xen_be_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
 805     qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev),
 806                         xen_be_evtchn_event, NULL, xendev);
 807     return 0;
 808 }
 809
 810 void xen_be_unbind_evtchn(struct XenDevice *xendev)
 811 {
 812     if (xendev->local_port == -1) {
 813         return;
 814     }
 815     qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev), NULL, NULL, NULL);
 816     xenevtchn_unbind(xendev->evtchndev, xendev->local_port);
 817     xen_be_printf(xendev, 2, "unbind evtchn port %d\n", xendev->local_port);
 818     xendev->local_port = -1;
 819 }
 820
 821 int xen_be_send_notify(struct XenDevice *xendev)
 822 {
 823     return xenevtchn_notify(xendev->evtchndev, xendev->local_port);
 824 }
 825
 826 /*
 827  * msg_level:
 828  *  0 == errors (stderr + logfile).
 829  *  1 == informative debug messages (logfile only).
 830  *  2 == noisy debug messages (logfile only).
 831  *  3 == will flood your log (logfile only).
 832  */
 833 void xen_be_printf(struct XenDevice *xendev, int msg_level, const char *fmt, ...)
 834 {
 835     va_list args;
 836
 837     if (xendev) {
 838         if (msg_level > xendev->debug) {
 839             return;
 840         }
 841         qemu_log("xen be: %s: ", xendev->name);
 842         if (msg_level == 0) {
 843             fprintf(stderr, "xen be: %s: ", xendev->name);
 844         }
 845     } else {
 846         if (msg_level > debug) {
 847             return;
 848         }
 849         qemu_log("xen be core: ");
 850         if (msg_level == 0) {
 851             fprintf(stderr, "xen be core: ");
 852         }
 853     }
 854     va_start(args, fmt);
 855     qemu_log_vprintf(fmt, args);
 856     va_end(args);
 857     if (msg_level == 0) {
 858         va_start(args, fmt);
 859         vfprintf(stderr, fmt, args);
 860         va_end(args);
 861     }
 862     qemu_log_flush();
 863 }
 864
 865 static int xen_sysdev_init(SysBusDevice *dev)
 866 {
 867     return 0;
 868 }
 869
 870 static Property xen_sysdev_properties[] = {
 871     {/* end of property list */},
 872 };
 873
 874 static void xen_sysdev_class_init(ObjectClass *klass, void *data)
 875 {
 876     DeviceClass *dc = DEVICE_CLASS(klass);
 877     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 878
 879     k->init = xen_sysdev_init;
 880     dc->props = xen_sysdev_properties;
 881 }
 882
 883 static const TypeInfo xensysdev_info = {
 884     .name          = TYPE_XENSYSDEV,
 885     .parent        = TYPE_SYS_BUS_DEVICE,
 886     .instance_size = sizeof(SysBusDevice),
 887     .class_init    = xen_sysdev_class_init,
 888 };
 889
 890 static void xenbe_register_types(void)
 891 {
 892     type_register_static(&xensysdev_info);
 893 }
 894
 895 type_init(xenbe_register_types);