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 "qemu/module.h"
  23 #include "sysemu/block-backend.h"
  24 #include "hw/scsi/scsi.h"
  25 #include "scsi/constants.h"
  26 #include "hw/virtio/virtio-bus.h"
  27 #include "hw/virtio/virtio-access.h"
  28
  29 static inline int virtio_scsi_get_lun(uint8_t *lun)
  30 {
  31     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  32 }
  33
  34 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  35 {
  36     if (lun[0] != 1) {
  37         return NULL;
  38     }
  39     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  40         return NULL;
  41     }
  42     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  43 }
  44
  45 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  46 {
  47     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  48     const size_t zero_skip =
  49         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  50
  51     req->vq = vq;
  52     req->dev = s;
  53     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
  54     qemu_iovec_init(&req->resp_iov, 1);
  55     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  56 }
  57
  58 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  59 {
  60     qemu_iovec_destroy(&req->resp_iov);
  61     qemu_sglist_destroy(&req->qsgl);
  62     g_free(req);
  63 }
  64
  65 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  66 {
  67     VirtIOSCSI *s = req->dev;
  68     VirtQueue *vq = req->vq;
  69     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  70
  71     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  72     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  73     if (s->dataplane_started && !s->dataplane_fenced) {
  74         virtio_notify_irqfd(vdev, vq);
  75     } else {
  76         virtio_notify(vdev, vq);
  77     }
  78
  79     if (req->sreq) {
  80         req->sreq->hba_private = NULL;
  81         scsi_req_unref(req->sreq);
  82     }
  83     virtio_scsi_free_req(req);
  84 }
  85
  86 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
  87 {
  88     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
  89     virtqueue_detach_element(req->vq, &req->elem, 0);
  90     virtio_scsi_free_req(req);
  91 }
  92
  93 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  94                               hwaddr *addr, int num, size_t skip)
  95 {
  96     QEMUSGList *qsgl = &req->qsgl;
  97     size_t copied = 0;
  98
  99     while (num) {
 100         if (skip >= iov->iov_len) {
 101             skip -= iov->iov_len;
 102         } else {
 103             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 104             copied += iov->iov_len - skip;
 105             skip = 0;
 106         }
 107         iov++;
 108         addr++;
 109         num--;
 110     }
 111
 112     assert(skip == 0);
 113     return copied;
 114 }
 115
 116 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 117                                  unsigned req_size, unsigned resp_size)
 118 {
 119     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 120     size_t in_size, out_size;
 121
 122     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 123                    &req->req, req_size) < req_size) {
 124         return -EINVAL;
 125     }
 126
 127     if (qemu_iovec_concat_iov(&req->resp_iov,
 128                               req->elem.in_sg, req->elem.in_num, 0,
 129                               resp_size) < resp_size) {
 130         return -EINVAL;
 131     }
 132
 133     req->resp_size = resp_size;
 134
 135     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 136      * As a workaround, always consider the first buffer as the virtio-scsi
 137      * request/response, making the payload start at the second element
 138      * of the iovec.
 139      *
 140      * The actual length of the response header, stored in req->resp_size,
 141      * does not change.
 142      *
 143      * TODO: always disable this workaround for virtio 1.0 devices.
 144      */
 145     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 146         if (req->elem.out_num) {
 147             req_size = req->elem.out_sg[0].iov_len;
 148         }
 149         if (req->elem.in_num) {
 150             resp_size = req->elem.in_sg[0].iov_len;
 151         }
 152     }
 153
 154     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 155                                &req->elem.out_addr[0], req->elem.out_num,
 156                                req_size);
 157     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 158                               &req->elem.in_addr[0], req->elem.in_num,
 159                               resp_size);
 160
 161     if (out_size && in_size) {
 162         return -ENOTSUP;
 163     }
 164
 165     if (out_size) {
 166         req->mode = SCSI_XFER_TO_DEV;
 167     } else if (in_size) {
 168         req->mode = SCSI_XFER_FROM_DEV;
 169     }
 170
 171     return 0;
 172 }
 173
 174 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 175 {
 176     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 177     VirtIOSCSIReq *req;
 178
 179     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 180     if (!req) {
 181         return NULL;
 182     }
 183     virtio_scsi_init_req(s, vq, req);
 184     return req;
 185 }
 186
 187 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 188 {
 189     VirtIOSCSIReq *req = sreq->hba_private;
 190     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 191     uint32_t n = virtio_get_queue_index(req->vq) - 2;
 192
 193     assert(n < vs->conf.num_queues);
 194     qemu_put_be32s(f, &n);
 195     qemu_put_virtqueue_element(f, &req->elem);
 196 }
 197
 198 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 199 {
 200     SCSIBus *bus = sreq->bus;
 201     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 202     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 203     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 204     VirtIOSCSIReq *req;
 205     uint32_t n;
 206
 207     qemu_get_be32s(f, &n);
 208     assert(n < vs->conf.num_queues);
 209     req = qemu_get_virtqueue_element(vdev, f,
 210                                      sizeof(VirtIOSCSIReq) + vs->cdb_size);
 211     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 212
 213     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 214                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 215         error_report("invalid SCSI request migration data");
 216         exit(1);
 217     }
 218
 219     scsi_req_ref(sreq);
 220     req->sreq = sreq;
 221     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 222         assert(req->sreq->cmd.mode == req->mode);
 223     }
 224     return req;
 225 }
 226
 227 typedef struct {
 228     Notifier        notifier;
 229     VirtIOSCSIReq  *tmf_req;
 230 } VirtIOSCSICancelNotifier;
 231
 232 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 233 {
 234     VirtIOSCSICancelNotifier *n = container_of(notifier,
 235                                                VirtIOSCSICancelNotifier,
 236                                                notifier);
 237
 238     if (--n->tmf_req->remaining == 0) {
 239         virtio_scsi_complete_req(n->tmf_req);
 240     }
 241     g_free(n);
 242 }
 243
 244 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
 245 {
 246     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
 247         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 248     }
 249 }
 250
 251 /* Return 0 if the request is ready to be completed and return to guest;
 252  * -EINPROGRESS if the request is submitted and will be completed later, in the
 253  *  case of async cancellation. */
 254 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 255 {
 256     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 257     SCSIRequest *r, *next;
 258     BusChild *kid;
 259     int target;
 260     int ret = 0;
 261
 262     virtio_scsi_ctx_check(s, d);
 263     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 264     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 265
 266     /*
 267      * req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
 268      * to avoid compiler errors.
 269      */
 270     req->req.tmf.subtype =
 271         virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
 272
 273     switch (req->req.tmf.subtype) {
 274     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 275     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 276         if (!d) {
 277             goto fail;
 278         }
 279         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 280             goto incorrect_lun;
 281         }
 282         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 283             VirtIOSCSIReq *cmd_req = r->hba_private;
 284             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 285                 break;
 286             }
 287         }
 288         if (r) {
 289             /*
 290              * Assert that the request has not been completed yet, we
 291              * check for it in the loop above.
 292              */
 293             assert(r->hba_private);
 294             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 295                 /* "If the specified command is present in the task set, then
 296                  * return a service response set to FUNCTION SUCCEEDED".
 297                  */
 298                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 299             } else {
 300                 VirtIOSCSICancelNotifier *notifier;
 301
 302                 req->remaining = 1;
 303                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 304                 notifier->tmf_req = req;
 305                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 306                 scsi_req_cancel_async(r, &notifier->notifier);
 307                 ret = -EINPROGRESS;
 308             }
 309         }
 310         break;
 311
 312     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 313         if (!d) {
 314             goto fail;
 315         }
 316         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 317             goto incorrect_lun;
 318         }
 319         s->resetting++;
 320         qdev_reset_all(&d->qdev);
 321         s->resetting--;
 322         break;
 323
 324     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 325     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 326     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 327         if (!d) {
 328             goto fail;
 329         }
 330         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 331             goto incorrect_lun;
 332         }
 333
 334         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 335          * This way, if the bus starts calling back to the notifiers
 336          * even before we finish the loop, virtio_scsi_cancel_notify
 337          * will not complete the TMF too early.
 338          */
 339         req->remaining = 1;
 340         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 341             if (r->hba_private) {
 342                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 343                     /* "If there is any command present in the task set, then
 344                      * return a service response set to FUNCTION SUCCEEDED".
 345                      */
 346                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 347                     break;
 348                 } else {
 349                     VirtIOSCSICancelNotifier *notifier;
 350
 351                     req->remaining++;
 352                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 353                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 354                     notifier->tmf_req = req;
 355                     scsi_req_cancel_async(r, &notifier->notifier);
 356                 }
 357             }
 358         }
 359         if (--req->remaining > 0) {
 360             ret = -EINPROGRESS;
 361         }
 362         break;
 363
 364     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 365         target = req->req.tmf.lun[1];
 366         s->resetting++;
 367         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 368              d = SCSI_DEVICE(kid->child);
 369              if (d->channel == 0 && d->id == target) {
 370                 qdev_reset_all(&d->qdev);
 371              }
 372         }
 373         s->resetting--;
 374         break;
 375
 376     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 377     default:
 378         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 379         break;
 380     }
 381
 382     return ret;
 383
 384 incorrect_lun:
 385     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 386     return ret;
 387
 388 fail:
 389     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 390     return ret;
 391 }
 392
 393 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 394 {
 395     VirtIODevice *vdev = (VirtIODevice *)s;
 396     uint32_t type;
 397     int r = 0;
 398
 399     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 400                 &type, sizeof(type)) < sizeof(type)) {
 401         virtio_scsi_bad_req(req);
 402         return;
 403     }
 404
 405     virtio_tswap32s(vdev, &type);
 406     if (type == VIRTIO_SCSI_T_TMF) {
 407         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 408                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 409             virtio_scsi_bad_req(req);
 410             return;
 411         } else {
 412             r = virtio_scsi_do_tmf(s, req);
 413         }
 414
 415     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 416                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 417         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 418                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 419             virtio_scsi_bad_req(req);
 420             return;
 421         } else {
 422             req->resp.an.event_actual = 0;
 423             req->resp.an.response = VIRTIO_SCSI_S_OK;
 424         }
 425     }
 426     if (r == 0) {
 427         virtio_scsi_complete_req(req);
 428     } else {
 429         assert(r == -EINPROGRESS);
 430     }
 431 }
 432
 433 bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 434 {
 435     VirtIOSCSIReq *req;
 436     bool progress = false;
 437
 438     while ((req = virtio_scsi_pop_req(s, vq))) {
 439         progress = true;
 440         virtio_scsi_handle_ctrl_req(s, req);
 441     }
 442     return progress;
 443 }
 444
 445 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 446 {
 447     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 448
 449     if (s->ctx) {
 450         virtio_device_start_ioeventfd(vdev);
 451         if (!s->dataplane_fenced) {
 452             return;
 453         }
 454     }
 455     virtio_scsi_acquire(s);
 456     virtio_scsi_handle_ctrl_vq(s, vq);
 457     virtio_scsi_release(s);
 458 }
 459
 460 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 461 {
 462     /* Sense data is not in req->resp and is copied separately
 463      * in virtio_scsi_command_complete.
 464      */
 465     req->resp_size = sizeof(VirtIOSCSICmdResp);
 466     virtio_scsi_complete_req(req);
 467 }
 468
 469 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 470                                          size_t resid)
 471 {
 472     VirtIOSCSIReq *req = r->hba_private;
 473     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 474     uint32_t sense_len;
 475     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 476
 477     if (r->io_canceled) {
 478         return;
 479     }
 480
 481     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 482     req->resp.cmd.status = status;
 483     if (req->resp.cmd.status == GOOD) {
 484         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 485     } else {
 486         req->resp.cmd.resid = 0;
 487         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 488         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 489         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 490                             sense, sense_len);
 491         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 492     }
 493     virtio_scsi_complete_cmd_req(req);
 494 }
 495
 496 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 497                                  uint8_t *buf, void *hba_private)
 498 {
 499     VirtIOSCSIReq *req = hba_private;
 500
 501     if (cmd->len == 0) {
 502         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 503         memcpy(cmd->buf, buf, cmd->len);
 504     }
 505
 506     /* Extract the direction and mode directly from the request, for
 507      * host device passthrough.
 508      */
 509     cmd->xfer = req->qsgl.size;
 510     cmd->mode = req->mode;
 511     return 0;
 512 }
 513
 514 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 515 {
 516     VirtIOSCSIReq *req = r->hba_private;
 517
 518     return &req->qsgl;
 519 }
 520
 521 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 522 {
 523     VirtIOSCSIReq *req = r->hba_private;
 524
 525     if (!req) {
 526         return;
 527     }
 528     if (req->dev->resetting) {
 529         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 530     } else {
 531         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 532     }
 533     virtio_scsi_complete_cmd_req(req);
 534 }
 535
 536 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 537 {
 538     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 539     virtio_scsi_complete_cmd_req(req);
 540 }
 541
 542 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 543 {
 544     VirtIOSCSICommon *vs = &s->parent_obj;
 545     SCSIDevice *d;
 546     int rc;
 547
 548     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 549                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 550     if (rc < 0) {
 551         if (rc == -ENOTSUP) {
 552             virtio_scsi_fail_cmd_req(req);
 553             return -ENOTSUP;
 554         } else {
 555             virtio_scsi_bad_req(req);
 556             return -EINVAL;
 557         }
 558     }
 559
 560     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 561     if (!d) {
 562         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 563         virtio_scsi_complete_cmd_req(req);
 564         return -ENOENT;
 565     }
 566     virtio_scsi_ctx_check(s, d);
 567     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 568                              virtio_scsi_get_lun(req->req.cmd.lun),
 569                              req->req.cmd.cdb, req);
 570
 571     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 572         && (req->sreq->cmd.mode != req->mode ||
 573             req->sreq->cmd.xfer > req->qsgl.size)) {
 574         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 575         virtio_scsi_complete_cmd_req(req);
 576         return -ENOBUFS;
 577     }
 578     scsi_req_ref(req->sreq);
 579     blk_io_plug(d->conf.blk);
 580     return 0;
 581 }
 582
 583 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 584 {
 585     SCSIRequest *sreq = req->sreq;
 586     if (scsi_req_enqueue(sreq)) {
 587         scsi_req_continue(sreq);
 588     }
 589     blk_io_unplug(sreq->dev->conf.blk);
 590     scsi_req_unref(sreq);
 591 }
 592
 593 bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 594 {
 595     VirtIOSCSIReq *req, *next;
 596     int ret = 0;
 597     bool progress = false;
 598
 599     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 600
 601     do {
 602         virtio_queue_set_notification(vq, 0);
 603
 604         while ((req = virtio_scsi_pop_req(s, vq))) {
 605             progress = true;
 606             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 607             if (!ret) {
 608                 QTAILQ_INSERT_TAIL(&reqs, req, next);
 609             } else if (ret == -EINVAL) {
 610                 /* The device is broken and shouldn't process any request */
 611                 while (!QTAILQ_EMPTY(&reqs)) {
 612                     req = QTAILQ_FIRST(&reqs);
 613                     QTAILQ_REMOVE(&reqs, req, next);
 614                     blk_io_unplug(req->sreq->dev->conf.blk);
 615                     scsi_req_unref(req->sreq);
 616                     virtqueue_detach_element(req->vq, &req->elem, 0);
 617                     virtio_scsi_free_req(req);
 618                 }
 619             }
 620         }
 621
 622         virtio_queue_set_notification(vq, 1);
 623     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 624
 625     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 626         virtio_scsi_handle_cmd_req_submit(s, req);
 627     }
 628     return progress;
 629 }
 630
 631 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 632 {
 633     /* use non-QOM casts in the data path */
 634     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 635
 636     if (s->ctx) {
 637         virtio_device_start_ioeventfd(vdev);
 638         if (!s->dataplane_fenced) {
 639             return;
 640         }
 641     }
 642     virtio_scsi_acquire(s);
 643     virtio_scsi_handle_cmd_vq(s, vq);
 644     virtio_scsi_release(s);
 645 }
 646
 647 static void virtio_scsi_get_config(VirtIODevice *vdev,
 648                                    uint8_t *config)
 649 {
 650     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 651     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 652
 653     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 654     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 655     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 656     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 657     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 658     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 659     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 660     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 661     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 662     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 663 }
 664
 665 static void virtio_scsi_set_config(VirtIODevice *vdev,
 666                                    const uint8_t *config)
 667 {
 668     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 669     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 670
 671     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 672         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 673         virtio_error(vdev,
 674                      "bad data written to virtio-scsi configuration space");
 675         return;
 676     }
 677
 678     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 679     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 680 }
 681
 682 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 683                                          uint64_t requested_features,
 684                                          Error **errp)
 685 {
 686     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 687
 688     /* Firstly sync all virtio-scsi possible supported features */
 689     requested_features |= s->host_features;
 690     return requested_features;
 691 }
 692
 693 static void virtio_scsi_reset(VirtIODevice *vdev)
 694 {
 695     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 696     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 697
 698     assert(!s->dataplane_started);
 699     s->resetting++;
 700     qbus_reset_all(BUS(&s->bus));
 701     s->resetting--;
 702
 703     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 704     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 705     s->events_dropped = false;
 706 }
 707
 708 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 709                             uint32_t event, uint32_t reason)
 710 {
 711     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 712     VirtIOSCSIReq *req;
 713     VirtIOSCSIEvent *evt;
 714     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 715
 716     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 717         return;
 718     }
 719
 720     req = virtio_scsi_pop_req(s, vs->event_vq);
 721     if (!req) {
 722         s->events_dropped = true;
 723         return;
 724     }
 725
 726     if (s->events_dropped) {
 727         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 728         s->events_dropped = false;
 729     }
 730
 731     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 732         virtio_scsi_bad_req(req);
 733         return;
 734     }
 735
 736     evt = &req->resp.event;
 737     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 738     evt->event = virtio_tswap32(vdev, event);
 739     evt->reason = virtio_tswap32(vdev, reason);
 740     if (!dev) {
 741         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 742     } else {
 743         evt->lun[0] = 1;
 744         evt->lun[1] = dev->id;
 745
 746         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 747         if (dev->lun >= 256) {
 748             evt->lun[2] = (dev->lun >> 8) | 0x40;
 749         }
 750         evt->lun[3] = dev->lun & 0xFF;
 751     }
 752     virtio_scsi_complete_req(req);
 753 }
 754
 755 bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 756 {
 757     if (s->events_dropped) {
 758         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 759         return true;
 760     }
 761     return false;
 762 }
 763
 764 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 765 {
 766     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 767
 768     if (s->ctx) {
 769         virtio_device_start_ioeventfd(vdev);
 770         if (!s->dataplane_fenced) {
 771             return;
 772         }
 773     }
 774     virtio_scsi_acquire(s);
 775     virtio_scsi_handle_event_vq(s, vq);
 776     virtio_scsi_release(s);
 777 }
 778
 779 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 780 {
 781     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 782     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 783
 784     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 785         dev->type != TYPE_ROM) {
 786         virtio_scsi_acquire(s);
 787         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 788                                sense.asc | (sense.ascq << 8));
 789         virtio_scsi_release(s);
 790     }
 791 }
 792
 793 static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
 794                                     DeviceState *dev, Error **errp)
 795 {
 796     SCSIDevice *sd = SCSI_DEVICE(dev);
 797     sd->hba_supports_iothread = true;
 798 }
 799
 800 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 801                                 Error **errp)
 802 {
 803     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 804     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 805     SCSIDevice *sd = SCSI_DEVICE(dev);
 806     int ret;
 807
 808     if (s->ctx && !s->dataplane_fenced) {
 809         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 810             return;
 811         }
 812         virtio_scsi_acquire(s);
 813         ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
 814         virtio_scsi_release(s);
 815         if (ret < 0) {
 816             return;
 817         }
 818     }
 819
 820     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 821         virtio_scsi_acquire(s);
 822         virtio_scsi_push_event(s, sd,
 823                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 824                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 825         virtio_scsi_release(s);
 826     }
 827 }
 828
 829 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 830                                   Error **errp)
 831 {
 832     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 833     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 834     SCSIDevice *sd = SCSI_DEVICE(dev);
 835
 836     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 837         virtio_scsi_acquire(s);
 838         virtio_scsi_push_event(s, sd,
 839                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 840                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 841         virtio_scsi_release(s);
 842     }
 843
 844     if (s->ctx) {
 845         virtio_scsi_acquire(s);
 846         /* If other users keep the BlockBackend in the iothread, that's ok */
 847         blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
 848         virtio_scsi_release(s);
 849     }
 850
 851     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 852 }
 853
 854 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 855     .tcq = true,
 856     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 857     .max_target = VIRTIO_SCSI_MAX_TARGET,
 858     .max_lun = VIRTIO_SCSI_MAX_LUN,
 859
 860     .complete = virtio_scsi_command_complete,
 861     .cancel = virtio_scsi_request_cancelled,
 862     .change = virtio_scsi_change,
 863     .parse_cdb = virtio_scsi_parse_cdb,
 864     .get_sg_list = virtio_scsi_get_sg_list,
 865     .save_request = virtio_scsi_save_request,
 866     .load_request = virtio_scsi_load_request,
 867 };
 868
 869 void virtio_scsi_common_realize(DeviceState *dev,
 870                                 VirtIOHandleOutput ctrl,
 871                                 VirtIOHandleOutput evt,
 872                                 VirtIOHandleOutput cmd,
 873                                 Error **errp)
 874 {
 875     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 876     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 877     int i;
 878
 879     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 880                 sizeof(VirtIOSCSIConfig));
 881
 882     if (s->conf.num_queues == 0 ||
 883             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 884         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 885                          "must be a positive integer less than %d.",
 886                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 887         virtio_cleanup(vdev);
 888         return;
 889     }
 890     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 891     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 892     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 893
 894     s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
 895     s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
 896     for (i = 0; i < s->conf.num_queues; i++) {
 897         s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
 898     }
 899 }
 900
 901 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 902 {
 903     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 904     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 905     Error *err = NULL;
 906
 907     virtio_scsi_common_realize(dev,
 908                                virtio_scsi_handle_ctrl,
 909                                virtio_scsi_handle_event,
 910                                virtio_scsi_handle_cmd,
 911                                &err);
 912     if (err != NULL) {
 913         error_propagate(errp, err);
 914         return;
 915     }
 916
 917     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 918                  &virtio_scsi_scsi_info, vdev->bus_name);
 919     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 920     qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev), &error_abort);
 921
 922     virtio_scsi_dataplane_setup(s, errp);
 923 }
 924
 925 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 926 {
 927     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 928     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 929
 930     g_free(vs->cmd_vqs);
 931     virtio_cleanup(vdev);
 932 }
 933
 934 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 935 {
 936     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 937
 938     qbus_set_hotplug_handler(BUS(&s->bus), NULL, &error_abort);
 939     virtio_scsi_common_unrealize(dev, errp);
 940 }
 941
 942 static Property virtio_scsi_properties[] = {
 943     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 944     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
 945                                          parent_obj.conf.virtqueue_size, 128),
 946     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 947                                                   0xFFFF),
 948     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 949                                                   128),
 950     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 951                                            VIRTIO_SCSI_F_HOTPLUG, true),
 952     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 953                                                 VIRTIO_SCSI_F_CHANGE, true),
 954     DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
 955                      TYPE_IOTHREAD, IOThread *),
 956     DEFINE_PROP_END_OF_LIST(),
 957 };
 958
 959 static const VMStateDescription vmstate_virtio_scsi = {
 960     .name = "virtio-scsi",
 961     .minimum_version_id = 1,
 962     .version_id = 1,
 963     .fields = (VMStateField[]) {
 964         VMSTATE_VIRTIO_DEVICE,
 965         VMSTATE_END_OF_LIST()
 966     },
 967 };
 968
 969 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 970 {
 971     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 972     DeviceClass *dc = DEVICE_CLASS(klass);
 973
 974     vdc->get_config = virtio_scsi_get_config;
 975     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 976 }
 977
 978 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 979 {
 980     DeviceClass *dc = DEVICE_CLASS(klass);
 981     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 982     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 983
 984     dc->props = virtio_scsi_properties;
 985     dc->vmsd = &vmstate_virtio_scsi;
 986     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 987     vdc->realize = virtio_scsi_device_realize;
 988     vdc->unrealize = virtio_scsi_device_unrealize;
 989     vdc->set_config = virtio_scsi_set_config;
 990     vdc->get_features = virtio_scsi_get_features;
 991     vdc->reset = virtio_scsi_reset;
 992     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
 993     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
 994     hc->pre_plug = virtio_scsi_pre_hotplug;
 995     hc->plug = virtio_scsi_hotplug;
 996     hc->unplug = virtio_scsi_hotunplug;
 997 }
 998
 999 static const TypeInfo virtio_scsi_common_info = {
1000     .name = TYPE_VIRTIO_SCSI_COMMON,
1001     .parent = TYPE_VIRTIO_DEVICE,
1002     .instance_size = sizeof(VirtIOSCSICommon),
1003     .abstract = true,
1004     .class_init = virtio_scsi_common_class_init,
1005 };
1006
1007 static const TypeInfo virtio_scsi_info = {
1008     .name = TYPE_VIRTIO_SCSI,
1009     .parent = TYPE_VIRTIO_SCSI_COMMON,
1010     .instance_size = sizeof(VirtIOSCSI),
1011     .class_init = virtio_scsi_class_init,
1012     .interfaces = (InterfaceInfo[]) {
1013         { TYPE_HOTPLUG_HANDLER },
1014         { }
1015     }
1016 };
1017
1018 static void virtio_register_types(void)
1019 {
1020     type_register_static(&virtio_scsi_common_info);
1021     type_register_static(&virtio_scsi_info);
1022 }
1023
1024 type_init(virtio_register_types)