hw/scsi/virtio-scsi.c

   1 /*
   2  * Virtio SCSI HBA
   3  *
   4  * Copyright IBM, Corp. 2010
   5  * Copyright Red Hat, Inc. 2011
   6  *
   7  * Authors:
   8  *   Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
   9  *   Paolo Bonzini      <pbonzini@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include "qemu/osdep.h"
  17 #include "qapi/error.h"
  18 #include "standard-headers/linux/virtio_ids.h"
  19 #include "hw/virtio/virtio-scsi.h"
  20 #include "qemu/error-report.h"
  21 #include "qemu/iov.h"
  22 #include "sysemu/block-backend.h"
  23 #include "hw/scsi/scsi.h"
  24 #include "block/scsi.h"
  25 #include "hw/virtio/virtio-bus.h"
  26 #include "hw/virtio/virtio-access.h"
  27
  28 static inline int virtio_scsi_get_lun(uint8_t *lun)
  29 {
  30     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  31 }
  32
  33 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  34 {
  35     if (lun[0] != 1) {
  36         return NULL;
  37     }
  38     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  39         return NULL;
  40     }
  41     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  42 }
  43
  44 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  45 {
  46     const size_t zero_skip =
  47         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  48
  49     req->vq = vq;
  50     req->dev = s;
  51     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, &address_space_memory);
  52     qemu_iovec_init(&req->resp_iov, 1);
  53     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  54 }
  55
  56 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  57 {
  58     qemu_iovec_destroy(&req->resp_iov);
  59     qemu_sglist_destroy(&req->qsgl);
  60     g_free(req);
  61 }
  62
  63 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  64 {
  65     VirtIOSCSI *s = req->dev;
  66     VirtQueue *vq = req->vq;
  67     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  68
  69     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  70     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  71     if (s->dataplane_started && !s->dataplane_fenced) {
  72         virtio_notify_irqfd(vdev, vq);
  73     } else {
  74         virtio_notify(vdev, vq);
  75     }
  76
  77     if (req->sreq) {
  78         req->sreq->hba_private = NULL;
  79         scsi_req_unref(req->sreq);
  80     }
  81     virtio_scsi_free_req(req);
  82 }
  83
  84 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
  85 {
  86     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
  87     virtqueue_detach_element(req->vq, &req->elem, 0);
  88     virtio_scsi_free_req(req);
  89 }
  90
  91 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  92                               hwaddr *addr, int num, size_t skip)
  93 {
  94     QEMUSGList *qsgl = &req->qsgl;
  95     size_t copied = 0;
  96
  97     while (num) {
  98         if (skip >= iov->iov_len) {
  99             skip -= iov->iov_len;
 100         } else {
 101             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 102             copied += iov->iov_len - skip;
 103             skip = 0;
 104         }
 105         iov++;
 106         addr++;
 107         num--;
 108     }
 109
 110     assert(skip == 0);
 111     return copied;
 112 }
 113
 114 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 115                                  unsigned req_size, unsigned resp_size)
 116 {
 117     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 118     size_t in_size, out_size;
 119
 120     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 121                    &req->req, req_size) < req_size) {
 122         return -EINVAL;
 123     }
 124
 125     if (qemu_iovec_concat_iov(&req->resp_iov,
 126                               req->elem.in_sg, req->elem.in_num, 0,
 127                               resp_size) < resp_size) {
 128         return -EINVAL;
 129     }
 130
 131     req->resp_size = resp_size;
 132
 133     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 134      * As a workaround, always consider the first buffer as the virtio-scsi
 135      * request/response, making the payload start at the second element
 136      * of the iovec.
 137      *
 138      * The actual length of the response header, stored in req->resp_size,
 139      * does not change.
 140      *
 141      * TODO: always disable this workaround for virtio 1.0 devices.
 142      */
 143     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 144         if (req->elem.out_num) {
 145             req_size = req->elem.out_sg[0].iov_len;
 146         }
 147         if (req->elem.in_num) {
 148             resp_size = req->elem.in_sg[0].iov_len;
 149         }
 150     }
 151
 152     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 153                                &req->elem.out_addr[0], req->elem.out_num,
 154                                req_size);
 155     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 156                               &req->elem.in_addr[0], req->elem.in_num,
 157                               resp_size);
 158
 159     if (out_size && in_size) {
 160         return -ENOTSUP;
 161     }
 162
 163     if (out_size) {
 164         req->mode = SCSI_XFER_TO_DEV;
 165     } else if (in_size) {
 166         req->mode = SCSI_XFER_FROM_DEV;
 167     }
 168
 169     return 0;
 170 }
 171
 172 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 173 {
 174     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 175     VirtIOSCSIReq *req;
 176
 177     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 178     if (!req) {
 179         return NULL;
 180     }
 181     virtio_scsi_init_req(s, vq, req);
 182     return req;
 183 }
 184
 185 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 186 {
 187     VirtIOSCSIReq *req = sreq->hba_private;
 188     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 189     uint32_t n = virtio_get_queue_index(req->vq) - 2;
 190
 191     assert(n < vs->conf.num_queues);
 192     qemu_put_be32s(f, &n);
 193     qemu_put_virtqueue_element(f, &req->elem);
 194 }
 195
 196 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 197 {
 198     SCSIBus *bus = sreq->bus;
 199     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 200     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 201     VirtIOSCSIReq *req;
 202     uint32_t n;
 203
 204     qemu_get_be32s(f, &n);
 205     assert(n < vs->conf.num_queues);
 206     req = qemu_get_virtqueue_element(f, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 207     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 208
 209     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 210                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 211         error_report("invalid SCSI request migration data");
 212         exit(1);
 213     }
 214
 215     scsi_req_ref(sreq);
 216     req->sreq = sreq;
 217     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 218         assert(req->sreq->cmd.mode == req->mode);
 219     }
 220     return req;
 221 }
 222
 223 typedef struct {
 224     Notifier        notifier;
 225     VirtIOSCSIReq  *tmf_req;
 226 } VirtIOSCSICancelNotifier;
 227
 228 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 229 {
 230     VirtIOSCSICancelNotifier *n = container_of(notifier,
 231                                                VirtIOSCSICancelNotifier,
 232                                                notifier);
 233
 234     if (--n->tmf_req->remaining == 0) {
 235         virtio_scsi_complete_req(n->tmf_req);
 236     }
 237     g_free(n);
 238 }
 239
 240 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
 241 {
 242     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
 243         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 244     }
 245 }
 246
 247 /* Return 0 if the request is ready to be completed and return to guest;
 248  * -EINPROGRESS if the request is submitted and will be completed later, in the
 249  *  case of async cancellation. */
 250 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 251 {
 252     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 253     SCSIRequest *r, *next;
 254     BusChild *kid;
 255     int target;
 256     int ret = 0;
 257
 258     virtio_scsi_ctx_check(s, d);
 259     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 260     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 261
 262     virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
 263     switch (req->req.tmf.subtype) {
 264     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 265     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 266         if (!d) {
 267             goto fail;
 268         }
 269         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 270             goto incorrect_lun;
 271         }
 272         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 273             VirtIOSCSIReq *cmd_req = r->hba_private;
 274             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 275                 break;
 276             }
 277         }
 278         if (r) {
 279             /*
 280              * Assert that the request has not been completed yet, we
 281              * check for it in the loop above.
 282              */
 283             assert(r->hba_private);
 284             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 285                 /* "If the specified command is present in the task set, then
 286                  * return a service response set to FUNCTION SUCCEEDED".
 287                  */
 288                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 289             } else {
 290                 VirtIOSCSICancelNotifier *notifier;
 291
 292                 req->remaining = 1;
 293                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 294                 notifier->tmf_req = req;
 295                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 296                 scsi_req_cancel_async(r, &notifier->notifier);
 297                 ret = -EINPROGRESS;
 298             }
 299         }
 300         break;
 301
 302     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 303         if (!d) {
 304             goto fail;
 305         }
 306         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 307             goto incorrect_lun;
 308         }
 309         s->resetting++;
 310         qdev_reset_all(&d->qdev);
 311         s->resetting--;
 312         break;
 313
 314     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 315     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 316     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 317         if (!d) {
 318             goto fail;
 319         }
 320         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 321             goto incorrect_lun;
 322         }
 323
 324         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 325          * This way, if the bus starts calling back to the notifiers
 326          * even before we finish the loop, virtio_scsi_cancel_notify
 327          * will not complete the TMF too early.
 328          */
 329         req->remaining = 1;
 330         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 331             if (r->hba_private) {
 332                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 333                     /* "If there is any command present in the task set, then
 334                      * return a service response set to FUNCTION SUCCEEDED".
 335                      */
 336                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 337                     break;
 338                 } else {
 339                     VirtIOSCSICancelNotifier *notifier;
 340
 341                     req->remaining++;
 342                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 343                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 344                     notifier->tmf_req = req;
 345                     scsi_req_cancel_async(r, &notifier->notifier);
 346                 }
 347             }
 348         }
 349         if (--req->remaining > 0) {
 350             ret = -EINPROGRESS;
 351         }
 352         break;
 353
 354     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 355         target = req->req.tmf.lun[1];
 356         s->resetting++;
 357         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 358              d = SCSI_DEVICE(kid->child);
 359              if (d->channel == 0 && d->id == target) {
 360                 qdev_reset_all(&d->qdev);
 361              }
 362         }
 363         s->resetting--;
 364         break;
 365
 366     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 367     default:
 368         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 369         break;
 370     }
 371
 372     return ret;
 373
 374 incorrect_lun:
 375     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 376     return ret;
 377
 378 fail:
 379     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 380     return ret;
 381 }
 382
 383 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 384 {
 385     VirtIODevice *vdev = (VirtIODevice *)s;
 386     uint32_t type;
 387     int r = 0;
 388
 389     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 390                 &type, sizeof(type)) < sizeof(type)) {
 391         virtio_scsi_bad_req(req);
 392         return;
 393     }
 394
 395     virtio_tswap32s(vdev, &type);
 396     if (type == VIRTIO_SCSI_T_TMF) {
 397         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 398                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 399             virtio_scsi_bad_req(req);
 400             return;
 401         } else {
 402             r = virtio_scsi_do_tmf(s, req);
 403         }
 404
 405     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 406                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 407         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 408                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 409             virtio_scsi_bad_req(req);
 410             return;
 411         } else {
 412             req->resp.an.event_actual = 0;
 413             req->resp.an.response = VIRTIO_SCSI_S_OK;
 414         }
 415     }
 416     if (r == 0) {
 417         virtio_scsi_complete_req(req);
 418     } else {
 419         assert(r == -EINPROGRESS);
 420     }
 421 }
 422
 423 static inline void virtio_scsi_acquire(VirtIOSCSI *s)
 424 {
 425     if (s->ctx) {
 426         aio_context_acquire(s->ctx);
 427     }
 428 }
 429
 430 static inline void virtio_scsi_release(VirtIOSCSI *s)
 431 {
 432     if (s->ctx) {
 433         aio_context_release(s->ctx);
 434     }
 435 }
 436
 437 void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 438 {
 439     VirtIOSCSIReq *req;
 440
 441     while ((req = virtio_scsi_pop_req(s, vq))) {
 442         virtio_scsi_handle_ctrl_req(s, req);
 443     }
 444 }
 445
 446 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 447 {
 448     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 449
 450     if (s->ctx) {
 451         virtio_device_start_ioeventfd(vdev);
 452         if (!s->dataplane_fenced) {
 453             return;
 454         }
 455     }
 456     virtio_scsi_handle_ctrl_vq(s, vq);
 457 }
 458
 459 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 460 {
 461     /* Sense data is not in req->resp and is copied separately
 462      * in virtio_scsi_command_complete.
 463      */
 464     req->resp_size = sizeof(VirtIOSCSICmdResp);
 465     virtio_scsi_complete_req(req);
 466 }
 467
 468 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 469                                          size_t resid)
 470 {
 471     VirtIOSCSIReq *req = r->hba_private;
 472     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 473     uint32_t sense_len;
 474     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 475
 476     if (r->io_canceled) {
 477         return;
 478     }
 479
 480     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 481     req->resp.cmd.status = status;
 482     if (req->resp.cmd.status == GOOD) {
 483         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 484     } else {
 485         req->resp.cmd.resid = 0;
 486         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 487         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 488         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 489                             sense, sense_len);
 490         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 491     }
 492     virtio_scsi_complete_cmd_req(req);
 493 }
 494
 495 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 496                                  uint8_t *buf, void *hba_private)
 497 {
 498     VirtIOSCSIReq *req = hba_private;
 499
 500     if (cmd->len == 0) {
 501         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 502         memcpy(cmd->buf, buf, cmd->len);
 503     }
 504
 505     /* Extract the direction and mode directly from the request, for
 506      * host device passthrough.
 507      */
 508     cmd->xfer = req->qsgl.size;
 509     cmd->mode = req->mode;
 510     return 0;
 511 }
 512
 513 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 514 {
 515     VirtIOSCSIReq *req = r->hba_private;
 516
 517     return &req->qsgl;
 518 }
 519
 520 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 521 {
 522     VirtIOSCSIReq *req = r->hba_private;
 523
 524     if (!req) {
 525         return;
 526     }
 527     if (req->dev->resetting) {
 528         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 529     } else {
 530         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 531     }
 532     virtio_scsi_complete_cmd_req(req);
 533 }
 534
 535 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 536 {
 537     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 538     virtio_scsi_complete_cmd_req(req);
 539 }
 540
 541 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 542 {
 543     VirtIOSCSICommon *vs = &s->parent_obj;
 544     SCSIDevice *d;
 545     int rc;
 546
 547     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 548                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 549     if (rc < 0) {
 550         if (rc == -ENOTSUP) {
 551             virtio_scsi_fail_cmd_req(req);
 552             return -ENOTSUP;
 553         } else {
 554             virtio_scsi_bad_req(req);
 555             return -EINVAL;
 556         }
 557     }
 558
 559     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 560     if (!d) {
 561         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 562         virtio_scsi_complete_cmd_req(req);
 563         return -ENOENT;
 564     }
 565     virtio_scsi_ctx_check(s, d);
 566     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 567                              virtio_scsi_get_lun(req->req.cmd.lun),
 568                              req->req.cmd.cdb, req);
 569
 570     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 571         && (req->sreq->cmd.mode != req->mode ||
 572             req->sreq->cmd.xfer > req->qsgl.size)) {
 573         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 574         virtio_scsi_complete_cmd_req(req);
 575         return -ENOBUFS;
 576     }
 577     scsi_req_ref(req->sreq);
 578     blk_io_plug(d->conf.blk);
 579     return 0;
 580 }
 581
 582 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 583 {
 584     SCSIRequest *sreq = req->sreq;
 585     if (scsi_req_enqueue(sreq)) {
 586         scsi_req_continue(sreq);
 587     }
 588     blk_io_unplug(sreq->dev->conf.blk);
 589     scsi_req_unref(sreq);
 590 }
 591
 592 void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 593 {
 594     VirtIOSCSIReq *req, *next;
 595     int ret;
 596
 597     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 598
 599     while ((req = virtio_scsi_pop_req(s, vq))) {
 600         ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 601         if (!ret) {
 602             QTAILQ_INSERT_TAIL(&reqs, req, next);
 603         } else if (ret == -EINVAL) {
 604             /* The device is broken and shouldn't process any request */
 605             while (!QTAILQ_EMPTY(&reqs)) {
 606                 req = QTAILQ_FIRST(&reqs);
 607                 QTAILQ_REMOVE(&reqs, req, next);
 608                 blk_io_unplug(req->sreq->dev->conf.blk);
 609                 scsi_req_unref(req->sreq);
 610                 virtqueue_detach_element(req->vq, &req->elem, 0);
 611                 virtio_scsi_free_req(req);
 612             }
 613         }
 614     }
 615
 616     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 617         virtio_scsi_handle_cmd_req_submit(s, req);
 618     }
 619 }
 620
 621 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 622 {
 623     /* use non-QOM casts in the data path */
 624     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 625
 626     if (s->ctx) {
 627         virtio_device_start_ioeventfd(vdev);
 628         if (!s->dataplane_fenced) {
 629             return;
 630         }
 631     }
 632     virtio_scsi_handle_cmd_vq(s, vq);
 633 }
 634
 635 static void virtio_scsi_get_config(VirtIODevice *vdev,
 636                                    uint8_t *config)
 637 {
 638     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 639     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 640
 641     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 642     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 643     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 644     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 645     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 646     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 647     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 648     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 649     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 650     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 651 }
 652
 653 static void virtio_scsi_set_config(VirtIODevice *vdev,
 654                                    const uint8_t *config)
 655 {
 656     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 657     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 658
 659     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 660         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 661         virtio_error(vdev,
 662                      "bad data written to virtio-scsi configuration space");
 663         return;
 664     }
 665
 666     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 667     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 668 }
 669
 670 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 671                                          uint64_t requested_features,
 672                                          Error **errp)
 673 {
 674     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 675
 676     /* Firstly sync all virtio-scsi possible supported features */
 677     requested_features |= s->host_features;
 678     return requested_features;
 679 }
 680
 681 static void virtio_scsi_reset(VirtIODevice *vdev)
 682 {
 683     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 684     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 685
 686     assert(!s->dataplane_started);
 687     s->resetting++;
 688     qbus_reset_all(&s->bus.qbus);
 689     s->resetting--;
 690
 691     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 692     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 693     s->events_dropped = false;
 694 }
 695
 696 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 697                             uint32_t event, uint32_t reason)
 698 {
 699     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 700     VirtIOSCSIReq *req;
 701     VirtIOSCSIEvent *evt;
 702     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 703
 704     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 705         return;
 706     }
 707
 708     virtio_scsi_acquire(s);
 709
 710     req = virtio_scsi_pop_req(s, vs->event_vq);
 711     if (!req) {
 712         s->events_dropped = true;
 713         goto out;
 714     }
 715
 716     if (s->events_dropped) {
 717         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 718         s->events_dropped = false;
 719     }
 720
 721     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 722         virtio_scsi_bad_req(req);
 723         goto out;
 724     }
 725
 726     evt = &req->resp.event;
 727     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 728     evt->event = virtio_tswap32(vdev, event);
 729     evt->reason = virtio_tswap32(vdev, reason);
 730     if (!dev) {
 731         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 732     } else {
 733         evt->lun[0] = 1;
 734         evt->lun[1] = dev->id;
 735
 736         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 737         if (dev->lun >= 256) {
 738             evt->lun[2] = (dev->lun >> 8) | 0x40;
 739         }
 740         evt->lun[3] = dev->lun & 0xFF;
 741     }
 742     virtio_scsi_complete_req(req);
 743 out:
 744     virtio_scsi_release(s);
 745 }
 746
 747 void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 748 {
 749     if (s->events_dropped) {
 750         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 751     }
 752 }
 753
 754 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 755 {
 756     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 757
 758     if (s->ctx) {
 759         virtio_device_start_ioeventfd(vdev);
 760         if (!s->dataplane_fenced) {
 761             return;
 762         }
 763     }
 764     virtio_scsi_handle_event_vq(s, vq);
 765 }
 766
 767 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 768 {
 769     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 770     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 771
 772     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 773         dev->type != TYPE_ROM) {
 774         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 775                                sense.asc | (sense.ascq << 8));
 776     }
 777 }
 778
 779 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 780                                 Error **errp)
 781 {
 782     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 783     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 784     SCSIDevice *sd = SCSI_DEVICE(dev);
 785
 786     if (s->ctx && !s->dataplane_fenced) {
 787         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 788             return;
 789         }
 790         virtio_scsi_acquire(s);
 791         blk_set_aio_context(sd->conf.blk, s->ctx);
 792         virtio_scsi_release(s);
 793
 794     }
 795
 796     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 797         virtio_scsi_push_event(s, sd,
 798                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 799                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 800     }
 801 }
 802
 803 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 804                                   Error **errp)
 805 {
 806     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 807     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 808     SCSIDevice *sd = SCSI_DEVICE(dev);
 809
 810     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 811         virtio_scsi_push_event(s, sd,
 812                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 813                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 814     }
 815
 816     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 817 }
 818
 819 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 820     .tcq = true,
 821     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 822     .max_target = VIRTIO_SCSI_MAX_TARGET,
 823     .max_lun = VIRTIO_SCSI_MAX_LUN,
 824
 825     .complete = virtio_scsi_command_complete,
 826     .cancel = virtio_scsi_request_cancelled,
 827     .change = virtio_scsi_change,
 828     .parse_cdb = virtio_scsi_parse_cdb,
 829     .get_sg_list = virtio_scsi_get_sg_list,
 830     .save_request = virtio_scsi_save_request,
 831     .load_request = virtio_scsi_load_request,
 832 };
 833
 834 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 835                                 VirtIOHandleOutput ctrl,
 836                                 VirtIOHandleOutput evt,
 837                                 VirtIOHandleOutput cmd)
 838 {
 839     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 840     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 841     int i;
 842
 843     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 844                 sizeof(VirtIOSCSIConfig));
 845
 846     if (s->conf.num_queues == 0 ||
 847             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 848         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 849                          "must be a positive integer less than %d.",
 850                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 851         virtio_cleanup(vdev);
 852         return;
 853     }
 854     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 855     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 856     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 857
 858     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE, ctrl);
 859     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE, evt);
 860     for (i = 0; i < s->conf.num_queues; i++) {
 861         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE, cmd);
 862     }
 863 }
 864
 865 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 866 {
 867     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 868     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 869     Error *err = NULL;
 870
 871     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 872                                virtio_scsi_handle_event,
 873                                virtio_scsi_handle_cmd);
 874     if (err != NULL) {
 875         error_propagate(errp, err);
 876         return;
 877     }
 878
 879     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 880                  &virtio_scsi_scsi_info, vdev->bus_name);
 881     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 882     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 883
 884     if (!dev->hotplugged) {
 885         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 886         if (err != NULL) {
 887             error_propagate(errp, err);
 888             return;
 889         }
 890     }
 891
 892     virtio_scsi_dataplane_setup(s, errp);
 893 }
 894
 895 static void virtio_scsi_instance_init(Object *obj)
 896 {
 897     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 898
 899     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 900                              (Object **)&vs->conf.iothread,
 901                              qdev_prop_allow_set_link_before_realize,
 902                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 903 }
 904
 905 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 906 {
 907     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 908     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 909
 910     g_free(vs->cmd_vqs);
 911     virtio_cleanup(vdev);
 912 }
 913
 914 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 915 {
 916     virtio_scsi_common_unrealize(dev, errp);
 917 }
 918
 919 static Property virtio_scsi_properties[] = {
 920     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 921     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 922                                                   0xFFFF),
 923     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 924                                                   128),
 925     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 926                                            VIRTIO_SCSI_F_HOTPLUG, true),
 927     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 928                                                 VIRTIO_SCSI_F_CHANGE, true),
 929     DEFINE_PROP_END_OF_LIST(),
 930 };
 931
 932 static const VMStateDescription vmstate_virtio_scsi = {
 933     .name = "virtio-scsi",
 934     .minimum_version_id = 1,
 935     .version_id = 1,
 936     .fields = (VMStateField[]) {
 937         VMSTATE_VIRTIO_DEVICE,
 938         VMSTATE_END_OF_LIST()
 939     },
 940 };
 941
 942 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 943 {
 944     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 945     DeviceClass *dc = DEVICE_CLASS(klass);
 946
 947     vdc->get_config = virtio_scsi_get_config;
 948     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 949 }
 950
 951 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 952 {
 953     DeviceClass *dc = DEVICE_CLASS(klass);
 954     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 955     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 956
 957     dc->props = virtio_scsi_properties;
 958     dc->vmsd = &vmstate_virtio_scsi;
 959     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 960     vdc->realize = virtio_scsi_device_realize;
 961     vdc->unrealize = virtio_scsi_device_unrealize;
 962     vdc->set_config = virtio_scsi_set_config;
 963     vdc->get_features = virtio_scsi_get_features;
 964     vdc->reset = virtio_scsi_reset;
 965     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
 966     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
 967     hc->plug = virtio_scsi_hotplug;
 968     hc->unplug = virtio_scsi_hotunplug;
 969 }
 970
 971 static const TypeInfo virtio_scsi_common_info = {
 972     .name = TYPE_VIRTIO_SCSI_COMMON,
 973     .parent = TYPE_VIRTIO_DEVICE,
 974     .instance_size = sizeof(VirtIOSCSICommon),
 975     .abstract = true,
 976     .class_init = virtio_scsi_common_class_init,
 977 };
 978
 979 static const TypeInfo virtio_scsi_info = {
 980     .name = TYPE_VIRTIO_SCSI,
 981     .parent = TYPE_VIRTIO_SCSI_COMMON,
 982     .instance_size = sizeof(VirtIOSCSI),
 983     .instance_init = virtio_scsi_instance_init,
 984     .class_init = virtio_scsi_class_init,
 985     .interfaces = (InterfaceInfo[]) {
 986         { TYPE_HOTPLUG_HANDLER },
 987         { }
 988     }
 989 };
 990
 991 static void virtio_register_types(void)
 992 {
 993     type_register_static(&virtio_scsi_common_info);
 994     type_register_static(&virtio_scsi_info);
 995 }
 996
 997 type_init(virtio_register_types)