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 "migration/qemu-file-types.h"
  21 #include "qemu/defer-call.h"
  22 #include "qemu/error-report.h"
  23 #include "qemu/iov.h"
  24 #include "qemu/module.h"
  25 #include "sysemu/block-backend.h"
  26 #include "sysemu/dma.h"
  27 #include "hw/qdev-properties.h"
  28 #include "hw/scsi/scsi.h"
  29 #include "scsi/constants.h"
  30 #include "hw/virtio/virtio-bus.h"
  31 #include "hw/virtio/virtio-access.h"
  32 #include "trace.h"
  33
  34 typedef struct VirtIOSCSIReq {
  35     /*
  36      * Note:
  37      * - fields up to resp_iov are initialized by virtio_scsi_init_req;
  38      * - fields starting at vring are zeroed by virtio_scsi_init_req.
  39      */
  40     VirtQueueElement elem;
  41
  42     VirtIOSCSI *dev;
  43     VirtQueue *vq;
  44     QEMUSGList qsgl;
  45     QEMUIOVector resp_iov;
  46
  47     /* Used for two-stage request submission and TMFs deferred to BH */
  48     QTAILQ_ENTRY(VirtIOSCSIReq) next;
  49
  50     /* Used for cancellation of request during TMFs */
  51     int remaining;
  52
  53     SCSIRequest *sreq;
  54     size_t resp_size;
  55     enum SCSIXferMode mode;
  56     union {
  57         VirtIOSCSICmdResp     cmd;
  58         VirtIOSCSICtrlTMFResp tmf;
  59         VirtIOSCSICtrlANResp  an;
  60         VirtIOSCSIEvent       event;
  61     } resp;
  62     union {
  63         VirtIOSCSICmdReq      cmd;
  64         VirtIOSCSICtrlTMFReq  tmf;
  65         VirtIOSCSICtrlANReq   an;
  66     } req;
  67 } VirtIOSCSIReq;
  68
  69 static inline int virtio_scsi_get_lun(uint8_t *lun)
  70 {
  71     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  72 }
  73
  74 static inline SCSIDevice *virtio_scsi_device_get(VirtIOSCSI *s, uint8_t *lun)
  75 {
  76     if (lun[0] != 1) {
  77         return NULL;
  78     }
  79     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  80         return NULL;
  81     }
  82     return scsi_device_get(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  83 }
  84
  85 static void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  86 {
  87     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  88     const size_t zero_skip =
  89         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  90
  91     req->vq = vq;
  92     req->dev = s;
  93     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
  94     qemu_iovec_init(&req->resp_iov, 1);
  95     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  96 }
  97
  98 static void virtio_scsi_free_req(VirtIOSCSIReq *req)
  99 {
 100     qemu_iovec_destroy(&req->resp_iov);
 101     qemu_sglist_destroy(&req->qsgl);
 102     g_free(req);
 103 }
 104
 105 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
 106 {
 107     VirtIOSCSI *s = req->dev;
 108     VirtQueue *vq = req->vq;
 109     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 110
 111     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
 112     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
 113     if (s->dataplane_started && !s->dataplane_fenced) {
 114         virtio_notify_irqfd(vdev, vq);
 115     } else {
 116         virtio_notify(vdev, vq);
 117     }
 118
 119     if (req->sreq) {
 120         req->sreq->hba_private = NULL;
 121         scsi_req_unref(req->sreq);
 122     }
 123     virtio_scsi_free_req(req);
 124 }
 125
 126 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
 127 {
 128     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
 129     virtqueue_detach_element(req->vq, &req->elem, 0);
 130     virtio_scsi_free_req(req);
 131 }
 132
 133 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
 134                               hwaddr *addr, int num, size_t skip)
 135 {
 136     QEMUSGList *qsgl = &req->qsgl;
 137     size_t copied = 0;
 138
 139     while (num) {
 140         if (skip >= iov->iov_len) {
 141             skip -= iov->iov_len;
 142         } else {
 143             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 144             copied += iov->iov_len - skip;
 145             skip = 0;
 146         }
 147         iov++;
 148         addr++;
 149         num--;
 150     }
 151
 152     assert(skip == 0);
 153     return copied;
 154 }
 155
 156 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 157                                  unsigned req_size, unsigned resp_size)
 158 {
 159     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 160     size_t in_size, out_size;
 161
 162     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 163                    &req->req, req_size) < req_size) {
 164         return -EINVAL;
 165     }
 166
 167     if (qemu_iovec_concat_iov(&req->resp_iov,
 168                               req->elem.in_sg, req->elem.in_num, 0,
 169                               resp_size) < resp_size) {
 170         return -EINVAL;
 171     }
 172
 173     req->resp_size = resp_size;
 174
 175     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 176      * As a workaround, always consider the first buffer as the virtio-scsi
 177      * request/response, making the payload start at the second element
 178      * of the iovec.
 179      *
 180      * The actual length of the response header, stored in req->resp_size,
 181      * does not change.
 182      *
 183      * TODO: always disable this workaround for virtio 1.0 devices.
 184      */
 185     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 186         if (req->elem.out_num) {
 187             req_size = req->elem.out_sg[0].iov_len;
 188         }
 189         if (req->elem.in_num) {
 190             resp_size = req->elem.in_sg[0].iov_len;
 191         }
 192     }
 193
 194     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 195                                &req->elem.out_addr[0], req->elem.out_num,
 196                                req_size);
 197     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 198                               &req->elem.in_addr[0], req->elem.in_num,
 199                               resp_size);
 200
 201     if (out_size && in_size) {
 202         return -ENOTSUP;
 203     }
 204
 205     if (out_size) {
 206         req->mode = SCSI_XFER_TO_DEV;
 207     } else if (in_size) {
 208         req->mode = SCSI_XFER_FROM_DEV;
 209     }
 210
 211     return 0;
 212 }
 213
 214 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 215 {
 216     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 217     VirtIOSCSIReq *req;
 218
 219     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 220     if (!req) {
 221         return NULL;
 222     }
 223     virtio_scsi_init_req(s, vq, req);
 224     return req;
 225 }
 226
 227 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 228 {
 229     VirtIOSCSIReq *req = sreq->hba_private;
 230     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 231     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 232     uint32_t n = virtio_get_queue_index(req->vq) - VIRTIO_SCSI_VQ_NUM_FIXED;
 233
 234     assert(n < vs->conf.num_queues);
 235     qemu_put_be32s(f, &n);
 236     qemu_put_virtqueue_element(vdev, f, &req->elem);
 237 }
 238
 239 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 240 {
 241     SCSIBus *bus = sreq->bus;
 242     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 243     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 244     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 245     VirtIOSCSIReq *req;
 246     uint32_t n;
 247
 248     qemu_get_be32s(f, &n);
 249     assert(n < vs->conf.num_queues);
 250     req = qemu_get_virtqueue_element(vdev, f,
 251                                      sizeof(VirtIOSCSIReq) + vs->cdb_size);
 252     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 253
 254     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 255                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 256         error_report("invalid SCSI request migration data");
 257         exit(1);
 258     }
 259
 260     scsi_req_ref(sreq);
 261     req->sreq = sreq;
 262     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 263         assert(req->sreq->cmd.mode == req->mode);
 264     }
 265     return req;
 266 }
 267
 268 typedef struct {
 269     Notifier        notifier;
 270     VirtIOSCSIReq  *tmf_req;
 271 } VirtIOSCSICancelNotifier;
 272
 273 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 274 {
 275     VirtIOSCSICancelNotifier *n = container_of(notifier,
 276                                                VirtIOSCSICancelNotifier,
 277                                                notifier);
 278
 279     if (--n->tmf_req->remaining == 0) {
 280         VirtIOSCSIReq *req = n->tmf_req;
 281
 282         trace_virtio_scsi_tmf_resp(virtio_scsi_get_lun(req->req.tmf.lun),
 283                                    req->req.tmf.tag, req->resp.tmf.response);
 284         virtio_scsi_complete_req(req);
 285     }
 286     g_free(n);
 287 }
 288
 289 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
 290 {
 291     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
 292         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 293     }
 294 }
 295
 296 static void virtio_scsi_do_one_tmf_bh(VirtIOSCSIReq *req)
 297 {
 298     VirtIOSCSI *s = req->dev;
 299     SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun);
 300     BusChild *kid;
 301     int target;
 302
 303     switch (req->req.tmf.subtype) {
 304     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 305         if (!d) {
 306             req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 307             goto out;
 308         }
 309         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 310             req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 311             goto out;
 312         }
 313         qatomic_inc(&s->resetting);
 314         device_cold_reset(&d->qdev);
 315         qatomic_dec(&s->resetting);
 316         break;
 317
 318     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 319         target = req->req.tmf.lun[1];
 320         qatomic_inc(&s->resetting);
 321
 322         rcu_read_lock();
 323         QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
 324             SCSIDevice *d1 = SCSI_DEVICE(kid->child);
 325             if (d1->channel == 0 && d1->id == target) {
 326                 device_cold_reset(&d1->qdev);
 327             }
 328         }
 329         rcu_read_unlock();
 330
 331         qatomic_dec(&s->resetting);
 332         break;
 333
 334     default:
 335         g_assert_not_reached();
 336         break;
 337     }
 338
 339 out:
 340     object_unref(OBJECT(d));
 341
 342     virtio_scsi_acquire(s);
 343     virtio_scsi_complete_req(req);
 344     virtio_scsi_release(s);
 345 }
 346
 347 /* Some TMFs must be processed from the main loop thread */
 348 static void virtio_scsi_do_tmf_bh(void *opaque)
 349 {
 350     VirtIOSCSI *s = opaque;
 351     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 352     VirtIOSCSIReq *req;
 353     VirtIOSCSIReq *tmp;
 354
 355     GLOBAL_STATE_CODE();
 356
 357     virtio_scsi_acquire(s);
 358
 359     QTAILQ_FOREACH_SAFE(req, &s->tmf_bh_list, next, tmp) {
 360         QTAILQ_REMOVE(&s->tmf_bh_list, req, next);
 361         QTAILQ_INSERT_TAIL(&reqs, req, next);
 362     }
 363
 364     qemu_bh_delete(s->tmf_bh);
 365     s->tmf_bh = NULL;
 366
 367     virtio_scsi_release(s);
 368
 369     QTAILQ_FOREACH_SAFE(req, &reqs, next, tmp) {
 370         QTAILQ_REMOVE(&reqs, req, next);
 371         virtio_scsi_do_one_tmf_bh(req);
 372     }
 373 }
 374
 375 static void virtio_scsi_reset_tmf_bh(VirtIOSCSI *s)
 376 {
 377     VirtIOSCSIReq *req;
 378     VirtIOSCSIReq *tmp;
 379
 380     GLOBAL_STATE_CODE();
 381
 382     virtio_scsi_acquire(s);
 383
 384     if (s->tmf_bh) {
 385         qemu_bh_delete(s->tmf_bh);
 386         s->tmf_bh = NULL;
 387     }
 388
 389     QTAILQ_FOREACH_SAFE(req, &s->tmf_bh_list, next, tmp) {
 390         QTAILQ_REMOVE(&s->tmf_bh_list, req, next);
 391
 392         /* SAM-6 6.3.2 Hard reset */
 393         req->resp.tmf.response = VIRTIO_SCSI_S_TARGET_FAILURE;
 394         virtio_scsi_complete_req(req);
 395     }
 396
 397     virtio_scsi_release(s);
 398 }
 399
 400 static void virtio_scsi_defer_tmf_to_bh(VirtIOSCSIReq *req)
 401 {
 402     VirtIOSCSI *s = req->dev;
 403
 404     QTAILQ_INSERT_TAIL(&s->tmf_bh_list, req, next);
 405
 406     if (!s->tmf_bh) {
 407         s->tmf_bh = qemu_bh_new(virtio_scsi_do_tmf_bh, s);
 408         qemu_bh_schedule(s->tmf_bh);
 409     }
 410 }
 411
 412 /* Return 0 if the request is ready to be completed and return to guest;
 413  * -EINPROGRESS if the request is submitted and will be completed later, in the
 414  *  case of async cancellation. */
 415 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 416 {
 417     SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun);
 418     SCSIRequest *r, *next;
 419     int ret = 0;
 420
 421     virtio_scsi_ctx_check(s, d);
 422     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 423     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 424
 425     /*
 426      * req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
 427      * to avoid compiler errors.
 428      */
 429     req->req.tmf.subtype =
 430         virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
 431
 432     trace_virtio_scsi_tmf_req(virtio_scsi_get_lun(req->req.tmf.lun),
 433                               req->req.tmf.tag, req->req.tmf.subtype);
 434
 435     switch (req->req.tmf.subtype) {
 436     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 437     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 438         if (!d) {
 439             goto fail;
 440         }
 441         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 442             goto incorrect_lun;
 443         }
 444         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 445             VirtIOSCSIReq *cmd_req = r->hba_private;
 446             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 447                 break;
 448             }
 449         }
 450         if (r) {
 451             /*
 452              * Assert that the request has not been completed yet, we
 453              * check for it in the loop above.
 454              */
 455             assert(r->hba_private);
 456             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 457                 /* "If the specified command is present in the task set, then
 458                  * return a service response set to FUNCTION SUCCEEDED".
 459                  */
 460                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 461             } else {
 462                 VirtIOSCSICancelNotifier *notifier;
 463
 464                 req->remaining = 1;
 465                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 466                 notifier->tmf_req = req;
 467                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 468                 scsi_req_cancel_async(r, &notifier->notifier);
 469                 ret = -EINPROGRESS;
 470             }
 471         }
 472         break;
 473
 474     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 475     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 476         virtio_scsi_defer_tmf_to_bh(req);
 477         ret = -EINPROGRESS;
 478         break;
 479
 480     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 481     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 482     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 483         if (!d) {
 484             goto fail;
 485         }
 486         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 487             goto incorrect_lun;
 488         }
 489
 490         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 491          * This way, if the bus starts calling back to the notifiers
 492          * even before we finish the loop, virtio_scsi_cancel_notify
 493          * will not complete the TMF too early.
 494          */
 495         req->remaining = 1;
 496         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 497             if (r->hba_private) {
 498                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 499                     /* "If there is any command present in the task set, then
 500                      * return a service response set to FUNCTION SUCCEEDED".
 501                      */
 502                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 503                     break;
 504                 } else {
 505                     VirtIOSCSICancelNotifier *notifier;
 506
 507                     req->remaining++;
 508                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 509                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 510                     notifier->tmf_req = req;
 511                     scsi_req_cancel_async(r, &notifier->notifier);
 512                 }
 513             }
 514         }
 515         if (--req->remaining > 0) {
 516             ret = -EINPROGRESS;
 517         }
 518         break;
 519
 520     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 521     default:
 522         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 523         break;
 524     }
 525
 526     object_unref(OBJECT(d));
 527     return ret;
 528
 529 incorrect_lun:
 530     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 531     object_unref(OBJECT(d));
 532     return ret;
 533
 534 fail:
 535     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 536     object_unref(OBJECT(d));
 537     return ret;
 538 }
 539
 540 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 541 {
 542     VirtIODevice *vdev = (VirtIODevice *)s;
 543     uint32_t type;
 544     int r = 0;
 545
 546     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 547                 &type, sizeof(type)) < sizeof(type)) {
 548         virtio_scsi_bad_req(req);
 549         return;
 550     }
 551
 552     virtio_tswap32s(vdev, &type);
 553     if (type == VIRTIO_SCSI_T_TMF) {
 554         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 555                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 556             virtio_scsi_bad_req(req);
 557             return;
 558         } else {
 559             r = virtio_scsi_do_tmf(s, req);
 560         }
 561
 562     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 563                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 564         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 565                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 566             virtio_scsi_bad_req(req);
 567             return;
 568         } else {
 569             req->req.an.event_requested =
 570                 virtio_tswap32(VIRTIO_DEVICE(s), req->req.an.event_requested);
 571             trace_virtio_scsi_an_req(virtio_scsi_get_lun(req->req.an.lun),
 572                                      req->req.an.event_requested);
 573             req->resp.an.event_actual = 0;
 574             req->resp.an.response = VIRTIO_SCSI_S_OK;
 575         }
 576     }
 577     if (r == 0) {
 578         if (type == VIRTIO_SCSI_T_TMF)
 579             trace_virtio_scsi_tmf_resp(virtio_scsi_get_lun(req->req.tmf.lun),
 580                                        req->req.tmf.tag,
 581                                        req->resp.tmf.response);
 582         else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 583                  type == VIRTIO_SCSI_T_AN_SUBSCRIBE)
 584             trace_virtio_scsi_an_resp(virtio_scsi_get_lun(req->req.an.lun),
 585                                       req->resp.an.response);
 586         virtio_scsi_complete_req(req);
 587     } else {
 588         assert(r == -EINPROGRESS);
 589     }
 590 }
 591
 592 static void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 593 {
 594     VirtIOSCSIReq *req;
 595
 596     while ((req = virtio_scsi_pop_req(s, vq))) {
 597         virtio_scsi_handle_ctrl_req(s, req);
 598     }
 599 }
 600
 601 /*
 602  * If dataplane is configured but not yet started, do so now and return true on
 603  * success.
 604  *
 605  * Dataplane is started by the core virtio code but virtqueue handler functions
 606  * can also be invoked when a guest kicks before DRIVER_OK, so this helper
 607  * function helps us deal with manually starting ioeventfd in that case.
 608  */
 609 static bool virtio_scsi_defer_to_dataplane(VirtIOSCSI *s)
 610 {
 611     if (!s->ctx || s->dataplane_started) {
 612         return false;
 613     }
 614
 615     virtio_device_start_ioeventfd(&s->parent_obj.parent_obj);
 616     return !s->dataplane_fenced;
 617 }
 618
 619 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 620 {
 621     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 622
 623     if (virtio_scsi_defer_to_dataplane(s)) {
 624         return;
 625     }
 626
 627     virtio_scsi_acquire(s);
 628     virtio_scsi_handle_ctrl_vq(s, vq);
 629     virtio_scsi_release(s);
 630 }
 631
 632 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 633 {
 634     trace_virtio_scsi_cmd_resp(virtio_scsi_get_lun(req->req.cmd.lun),
 635                                req->req.cmd.tag,
 636                                req->resp.cmd.response,
 637                                req->resp.cmd.status);
 638     /* Sense data is not in req->resp and is copied separately
 639      * in virtio_scsi_command_complete.
 640      */
 641     req->resp_size = sizeof(VirtIOSCSICmdResp);
 642     virtio_scsi_complete_req(req);
 643 }
 644
 645 static void virtio_scsi_command_failed(SCSIRequest *r)
 646 {
 647     VirtIOSCSIReq *req = r->hba_private;
 648
 649     if (r->io_canceled) {
 650         return;
 651     }
 652
 653     req->resp.cmd.status = GOOD;
 654     switch (r->host_status) {
 655     case SCSI_HOST_NO_LUN:
 656         req->resp.cmd.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 657         break;
 658     case SCSI_HOST_BUSY:
 659         req->resp.cmd.response = VIRTIO_SCSI_S_BUSY;
 660         break;
 661     case SCSI_HOST_TIME_OUT:
 662     case SCSI_HOST_ABORTED:
 663         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 664         break;
 665     case SCSI_HOST_BAD_RESPONSE:
 666         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 667         break;
 668     case SCSI_HOST_RESET:
 669         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 670         break;
 671     case SCSI_HOST_TRANSPORT_DISRUPTED:
 672         req->resp.cmd.response = VIRTIO_SCSI_S_TRANSPORT_FAILURE;
 673         break;
 674     case SCSI_HOST_TARGET_FAILURE:
 675         req->resp.cmd.response = VIRTIO_SCSI_S_TARGET_FAILURE;
 676         break;
 677     case SCSI_HOST_RESERVATION_ERROR:
 678         req->resp.cmd.response = VIRTIO_SCSI_S_NEXUS_FAILURE;
 679         break;
 680     case SCSI_HOST_ALLOCATION_FAILURE:
 681     case SCSI_HOST_MEDIUM_ERROR:
 682     case SCSI_HOST_ERROR:
 683     default:
 684         req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 685         break;
 686     }
 687     virtio_scsi_complete_cmd_req(req);
 688 }
 689
 690 static void virtio_scsi_command_complete(SCSIRequest *r, size_t resid)
 691 {
 692     VirtIOSCSIReq *req = r->hba_private;
 693     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 694     uint32_t sense_len;
 695     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 696
 697     if (r->io_canceled) {
 698         return;
 699     }
 700
 701     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 702     req->resp.cmd.status = r->status;
 703     if (req->resp.cmd.status == GOOD) {
 704         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 705     } else {
 706         req->resp.cmd.resid = 0;
 707         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 708         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 709         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 710                             sense, sense_len);
 711         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 712     }
 713     virtio_scsi_complete_cmd_req(req);
 714 }
 715
 716 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 717                                  uint8_t *buf, size_t buf_len,
 718                                  void *hba_private)
 719 {
 720     VirtIOSCSIReq *req = hba_private;
 721
 722     if (cmd->len == 0) {
 723         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 724         memcpy(cmd->buf, buf, cmd->len);
 725     }
 726
 727     /* Extract the direction and mode directly from the request, for
 728      * host device passthrough.
 729      */
 730     cmd->xfer = req->qsgl.size;
 731     cmd->mode = req->mode;
 732     return 0;
 733 }
 734
 735 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 736 {
 737     VirtIOSCSIReq *req = r->hba_private;
 738
 739     return &req->qsgl;
 740 }
 741
 742 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 743 {
 744     VirtIOSCSIReq *req = r->hba_private;
 745
 746     if (!req) {
 747         return;
 748     }
 749     if (qatomic_read(&req->dev->resetting)) {
 750         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 751     } else {
 752         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 753     }
 754     virtio_scsi_complete_cmd_req(req);
 755 }
 756
 757 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 758 {
 759     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 760     virtio_scsi_complete_cmd_req(req);
 761 }
 762
 763 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 764 {
 765     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 766     SCSIDevice *d;
 767     int rc;
 768
 769     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 770                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 771     if (rc < 0) {
 772         if (rc == -ENOTSUP) {
 773             virtio_scsi_fail_cmd_req(req);
 774             return -ENOTSUP;
 775         } else {
 776             virtio_scsi_bad_req(req);
 777             return -EINVAL;
 778         }
 779     }
 780     trace_virtio_scsi_cmd_req(virtio_scsi_get_lun(req->req.cmd.lun),
 781                               req->req.cmd.tag, req->req.cmd.cdb[0]);
 782
 783     d = virtio_scsi_device_get(s, req->req.cmd.lun);
 784     if (!d) {
 785         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 786         virtio_scsi_complete_cmd_req(req);
 787         return -ENOENT;
 788     }
 789     virtio_scsi_ctx_check(s, d);
 790     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 791                              virtio_scsi_get_lun(req->req.cmd.lun),
 792                              req->req.cmd.cdb, vs->cdb_size, req);
 793
 794     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 795         && (req->sreq->cmd.mode != req->mode ||
 796             req->sreq->cmd.xfer > req->qsgl.size)) {
 797         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 798         virtio_scsi_complete_cmd_req(req);
 799         object_unref(OBJECT(d));
 800         return -ENOBUFS;
 801     }
 802     scsi_req_ref(req->sreq);
 803     defer_call_begin();
 804     object_unref(OBJECT(d));
 805     return 0;
 806 }
 807
 808 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 809 {
 810     SCSIRequest *sreq = req->sreq;
 811     if (scsi_req_enqueue(sreq)) {
 812         scsi_req_continue(sreq);
 813     }
 814     defer_call_end();
 815     scsi_req_unref(sreq);
 816 }
 817
 818 static void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 819 {
 820     VirtIOSCSIReq *req, *next;
 821     int ret = 0;
 822     bool suppress_notifications = virtio_queue_get_notification(vq);
 823
 824     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 825
 826     do {
 827         if (suppress_notifications) {
 828             virtio_queue_set_notification(vq, 0);
 829         }
 830
 831         while ((req = virtio_scsi_pop_req(s, vq))) {
 832             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 833             if (!ret) {
 834                 QTAILQ_INSERT_TAIL(&reqs, req, next);
 835             } else if (ret == -EINVAL) {
 836                 /* The device is broken and shouldn't process any request */
 837                 while (!QTAILQ_EMPTY(&reqs)) {
 838                     req = QTAILQ_FIRST(&reqs);
 839                     QTAILQ_REMOVE(&reqs, req, next);
 840                     defer_call_end();
 841                     scsi_req_unref(req->sreq);
 842                     virtqueue_detach_element(req->vq, &req->elem, 0);
 843                     virtio_scsi_free_req(req);
 844                 }
 845             }
 846         }
 847
 848         if (suppress_notifications) {
 849             virtio_queue_set_notification(vq, 1);
 850         }
 851     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 852
 853     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 854         virtio_scsi_handle_cmd_req_submit(s, req);
 855     }
 856 }
 857
 858 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 859 {
 860     /* use non-QOM casts in the data path */
 861     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 862
 863     if (virtio_scsi_defer_to_dataplane(s)) {
 864         return;
 865     }
 866
 867     virtio_scsi_acquire(s);
 868     virtio_scsi_handle_cmd_vq(s, vq);
 869     virtio_scsi_release(s);
 870 }
 871
 872 static void virtio_scsi_get_config(VirtIODevice *vdev,
 873                                    uint8_t *config)
 874 {
 875     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 876     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 877
 878     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 879     virtio_stl_p(vdev, &scsiconf->seg_max,
 880                  s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
 881     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 882     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 883     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 884     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 885     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 886     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 887     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 888     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 889 }
 890
 891 static void virtio_scsi_set_config(VirtIODevice *vdev,
 892                                    const uint8_t *config)
 893 {
 894     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 895     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 896
 897     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 898         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 899         virtio_error(vdev,
 900                      "bad data written to virtio-scsi configuration space");
 901         return;
 902     }
 903
 904     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 905     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 906 }
 907
 908 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 909                                          uint64_t requested_features,
 910                                          Error **errp)
 911 {
 912     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 913
 914     /* Firstly sync all virtio-scsi possible supported features */
 915     requested_features |= s->host_features;
 916     return requested_features;
 917 }
 918
 919 static void virtio_scsi_reset(VirtIODevice *vdev)
 920 {
 921     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 922     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 923
 924     assert(!s->dataplane_started);
 925
 926     virtio_scsi_reset_tmf_bh(s);
 927
 928     qatomic_inc(&s->resetting);
 929     bus_cold_reset(BUS(&s->bus));
 930     qatomic_dec(&s->resetting);
 931
 932     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 933     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 934     s->events_dropped = false;
 935 }
 936
 937 typedef struct {
 938     uint32_t event;
 939     uint32_t reason;
 940     union {
 941         /* Used by messages specific to a device */
 942         struct {
 943             uint32_t id;
 944             uint32_t lun;
 945         } address;
 946     };
 947 } VirtIOSCSIEventInfo;
 948
 949 static void virtio_scsi_push_event(VirtIOSCSI *s,
 950                                    const VirtIOSCSIEventInfo *info)
 951 {
 952     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 953     VirtIOSCSIReq *req;
 954     VirtIOSCSIEvent *evt;
 955     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 956     uint32_t event = info->event;
 957     uint32_t reason = info->reason;
 958
 959     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 960         return;
 961     }
 962
 963     req = virtio_scsi_pop_req(s, vs->event_vq);
 964     if (!req) {
 965         s->events_dropped = true;
 966         return;
 967     }
 968
 969     if (s->events_dropped) {
 970         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 971         s->events_dropped = false;
 972     }
 973
 974     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 975         virtio_scsi_bad_req(req);
 976         return;
 977     }
 978
 979     evt = &req->resp.event;
 980     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 981     evt->event = virtio_tswap32(vdev, event);
 982     evt->reason = virtio_tswap32(vdev, reason);
 983     if (event != VIRTIO_SCSI_T_EVENTS_MISSED) {
 984         evt->lun[0] = 1;
 985         evt->lun[1] = info->address.id;
 986
 987         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 988         if (info->address.lun >= 256) {
 989             evt->lun[2] = (info->address.lun >> 8) | 0x40;
 990         }
 991         evt->lun[3] = info->address.lun & 0xFF;
 992     }
 993     trace_virtio_scsi_event(virtio_scsi_get_lun(evt->lun), event, reason);
 994
 995     virtio_scsi_complete_req(req);
 996 }
 997
 998 static void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 999 {
1000     if (s->events_dropped) {
1001         VirtIOSCSIEventInfo info = {
1002             .event = VIRTIO_SCSI_T_NO_EVENT,
1003         };
1004         virtio_scsi_push_event(s, &info);
1005     }
1006 }
1007
1008 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
1009 {
1010     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
1011
1012     if (virtio_scsi_defer_to_dataplane(s)) {
1013         return;
1014     }
1015
1016     virtio_scsi_acquire(s);
1017     virtio_scsi_handle_event_vq(s, vq);
1018     virtio_scsi_release(s);
1019 }
1020
1021 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
1022 {
1023     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
1024     VirtIODevice *vdev = VIRTIO_DEVICE(s);
1025
1026     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
1027         dev->type != TYPE_ROM) {
1028         VirtIOSCSIEventInfo info = {
1029             .event   = VIRTIO_SCSI_T_PARAM_CHANGE,
1030             .reason  = sense.asc | (sense.ascq << 8),
1031             .address = {
1032                 .id  = dev->id,
1033                 .lun = dev->lun,
1034             },
1035         };
1036
1037         virtio_scsi_acquire(s);
1038         virtio_scsi_push_event(s, &info);
1039         virtio_scsi_release(s);
1040     }
1041 }
1042
1043 static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
1044                                     DeviceState *dev, Error **errp)
1045 {
1046     SCSIDevice *sd = SCSI_DEVICE(dev);
1047     sd->hba_supports_iothread = true;
1048 }
1049
1050 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
1051                                 Error **errp)
1052 {
1053     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
1054     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
1055     SCSIDevice *sd = SCSI_DEVICE(dev);
1056     AioContext *old_context;
1057     int ret;
1058
1059     if (s->ctx && !s->dataplane_fenced) {
1060         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
1061             return;
1062         }
1063         old_context = blk_get_aio_context(sd->conf.blk);
1064         aio_context_acquire(old_context);
1065         ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
1066         aio_context_release(old_context);
1067         if (ret < 0) {
1068             return;
1069         }
1070     }
1071
1072     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
1073         VirtIOSCSIEventInfo info = {
1074             .event   = VIRTIO_SCSI_T_TRANSPORT_RESET,
1075             .reason  = VIRTIO_SCSI_EVT_RESET_RESCAN,
1076             .address = {
1077                 .id  = sd->id,
1078                 .lun = sd->lun,
1079             },
1080         };
1081
1082         virtio_scsi_acquire(s);
1083         virtio_scsi_push_event(s, &info);
1084         scsi_bus_set_ua(&s->bus, SENSE_CODE(REPORTED_LUNS_CHANGED));
1085         virtio_scsi_release(s);
1086     }
1087 }
1088
1089 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
1090                                   Error **errp)
1091 {
1092     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
1093     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
1094     SCSIDevice *sd = SCSI_DEVICE(dev);
1095     VirtIOSCSIEventInfo info = {
1096         .event   = VIRTIO_SCSI_T_TRANSPORT_RESET,
1097         .reason  = VIRTIO_SCSI_EVT_RESET_REMOVED,
1098         .address = {
1099             .id  = sd->id,
1100             .lun = sd->lun,
1101         },
1102     };
1103
1104     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
1105
1106     if (s->ctx) {
1107         virtio_scsi_acquire(s);
1108         /* If other users keep the BlockBackend in the iothread, that's ok */
1109         blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
1110         virtio_scsi_release(s);
1111     }
1112
1113     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
1114         virtio_scsi_acquire(s);
1115         virtio_scsi_push_event(s, &info);
1116         scsi_bus_set_ua(&s->bus, SENSE_CODE(REPORTED_LUNS_CHANGED));
1117         virtio_scsi_release(s);
1118     }
1119 }
1120
1121 /* Suspend virtqueue ioeventfd processing during drain */
1122 static void virtio_scsi_drained_begin(SCSIBus *bus)
1123 {
1124     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
1125     VirtIODevice *vdev = VIRTIO_DEVICE(s);
1126     uint32_t total_queues = VIRTIO_SCSI_VQ_NUM_FIXED +
1127                             s->parent_obj.conf.num_queues;
1128
1129     /*
1130      * Drain is called when stopping dataplane but the host notifier has
1131      * already been detached. Detaching multiple times is a no-op if nothing
1132      * else is using the monitoring same file descriptor, but avoid it just in
1133      * case.
1134      *
1135      * Also, don't detach if dataplane has not even been started yet because
1136      * the host notifier isn't attached.
1137      */
1138     if (s->dataplane_stopping || !s->dataplane_started) {
1139         return;
1140     }
1141
1142     for (uint32_t i = 0; i < total_queues; i++) {
1143         VirtQueue *vq = virtio_get_queue(vdev, i);
1144         virtio_queue_aio_detach_host_notifier(vq, s->ctx);
1145     }
1146 }
1147
1148 /* Resume virtqueue ioeventfd processing after drain */
1149 static void virtio_scsi_drained_end(SCSIBus *bus)
1150 {
1151     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
1152     VirtIODevice *vdev = VIRTIO_DEVICE(s);
1153     uint32_t total_queues = VIRTIO_SCSI_VQ_NUM_FIXED +
1154                             s->parent_obj.conf.num_queues;
1155
1156     /*
1157      * Drain is called when stopping dataplane. Keep the host notifier detached
1158      * so it's not left dangling after dataplane is stopped.
1159      *
1160      * Also, don't attach if dataplane has not even been started yet. We're not
1161      * ready.
1162      */
1163     if (s->dataplane_stopping || !s->dataplane_started) {
1164         return;
1165     }
1166
1167     for (uint32_t i = 0; i < total_queues; i++) {
1168         VirtQueue *vq = virtio_get_queue(vdev, i);
1169         virtio_queue_aio_attach_host_notifier(vq, s->ctx);
1170     }
1171 }
1172
1173 static struct SCSIBusInfo virtio_scsi_scsi_info = {
1174     .tcq = true,
1175     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
1176     .max_target = VIRTIO_SCSI_MAX_TARGET,
1177     .max_lun = VIRTIO_SCSI_MAX_LUN,
1178
1179     .complete = virtio_scsi_command_complete,
1180     .fail = virtio_scsi_command_failed,
1181     .cancel = virtio_scsi_request_cancelled,
1182     .change = virtio_scsi_change,
1183     .parse_cdb = virtio_scsi_parse_cdb,
1184     .get_sg_list = virtio_scsi_get_sg_list,
1185     .save_request = virtio_scsi_save_request,
1186     .load_request = virtio_scsi_load_request,
1187     .drained_begin = virtio_scsi_drained_begin,
1188     .drained_end = virtio_scsi_drained_end,
1189 };
1190
1191 void virtio_scsi_common_realize(DeviceState *dev,
1192                                 VirtIOHandleOutput ctrl,
1193                                 VirtIOHandleOutput evt,
1194                                 VirtIOHandleOutput cmd,
1195                                 Error **errp)
1196 {
1197     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1198     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
1199     int i;
1200
1201     virtio_init(vdev, VIRTIO_ID_SCSI, sizeof(VirtIOSCSIConfig));
1202
1203     if (s->conf.num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
1204         s->conf.num_queues = 1;
1205     }
1206     if (s->conf.num_queues == 0 ||
1207             s->conf.num_queues > VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED) {
1208         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
1209                          "must be a positive integer less than %d.",
1210                    s->conf.num_queues,
1211                    VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED);
1212         virtio_cleanup(vdev);
1213         return;
1214     }
1215     if (s->conf.virtqueue_size <= 2) {
1216         error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
1217                    "must be > 2", s->conf.virtqueue_size);
1218         return;
1219     }
1220     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
1221     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
1222     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
1223
1224     s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
1225     s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
1226     for (i = 0; i < s->conf.num_queues; i++) {
1227         s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
1228     }
1229 }
1230
1231 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
1232 {
1233     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1234     VirtIOSCSI *s = VIRTIO_SCSI(dev);
1235     Error *err = NULL;
1236
1237     QTAILQ_INIT(&s->tmf_bh_list);
1238
1239     virtio_scsi_common_realize(dev,
1240                                virtio_scsi_handle_ctrl,
1241                                virtio_scsi_handle_event,
1242                                virtio_scsi_handle_cmd,
1243                                &err);
1244     if (err != NULL) {
1245         error_propagate(errp, err);
1246         return;
1247     }
1248
1249     scsi_bus_init_named(&s->bus, sizeof(s->bus), dev,
1250                        &virtio_scsi_scsi_info, vdev->bus_name);
1251     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
1252     qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev));
1253
1254     virtio_scsi_dataplane_setup(s, errp);
1255 }
1256
1257 void virtio_scsi_common_unrealize(DeviceState *dev)
1258 {
1259     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1260     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
1261     int i;
1262
1263     virtio_delete_queue(vs->ctrl_vq);
1264     virtio_delete_queue(vs->event_vq);
1265     for (i = 0; i < vs->conf.num_queues; i++) {
1266         virtio_delete_queue(vs->cmd_vqs[i]);
1267     }
1268     g_free(vs->cmd_vqs);
1269     virtio_cleanup(vdev);
1270 }
1271
1272 static void virtio_scsi_device_unrealize(DeviceState *dev)
1273 {
1274     VirtIOSCSI *s = VIRTIO_SCSI(dev);
1275
1276     virtio_scsi_reset_tmf_bh(s);
1277
1278     qbus_set_hotplug_handler(BUS(&s->bus), NULL);
1279     virtio_scsi_common_unrealize(dev);
1280 }
1281
1282 static Property virtio_scsi_properties[] = {
1283     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues,
1284                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
1285     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
1286                                          parent_obj.conf.virtqueue_size, 256),
1287     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
1288                       parent_obj.conf.seg_max_adjust, true),
1289     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
1290                                                   0xFFFF),
1291     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
1292                                                   128),
1293     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
1294                                            VIRTIO_SCSI_F_HOTPLUG, true),
1295     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
1296                                                 VIRTIO_SCSI_F_CHANGE, true),
1297     DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
1298                      TYPE_IOTHREAD, IOThread *),
1299     DEFINE_PROP_END_OF_LIST(),
1300 };
1301
1302 static const VMStateDescription vmstate_virtio_scsi = {
1303     .name = "virtio-scsi",
1304     .minimum_version_id = 1,
1305     .version_id = 1,
1306     .fields = (VMStateField[]) {
1307         VMSTATE_VIRTIO_DEVICE,
1308         VMSTATE_END_OF_LIST()
1309     },
1310 };
1311
1312 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
1313 {
1314     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1315     DeviceClass *dc = DEVICE_CLASS(klass);
1316
1317     vdc->get_config = virtio_scsi_get_config;
1318     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1319 }
1320
1321 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
1322 {
1323     DeviceClass *dc = DEVICE_CLASS(klass);
1324     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1325     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1326
1327     device_class_set_props(dc, virtio_scsi_properties);
1328     dc->vmsd = &vmstate_virtio_scsi;
1329     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1330     vdc->realize = virtio_scsi_device_realize;
1331     vdc->unrealize = virtio_scsi_device_unrealize;
1332     vdc->set_config = virtio_scsi_set_config;
1333     vdc->get_features = virtio_scsi_get_features;
1334     vdc->reset = virtio_scsi_reset;
1335     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
1336     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
1337     hc->pre_plug = virtio_scsi_pre_hotplug;
1338     hc->plug = virtio_scsi_hotplug;
1339     hc->unplug = virtio_scsi_hotunplug;
1340 }
1341
1342 static const TypeInfo virtio_scsi_common_info = {
1343     .name = TYPE_VIRTIO_SCSI_COMMON,
1344     .parent = TYPE_VIRTIO_DEVICE,
1345     .instance_size = sizeof(VirtIOSCSICommon),
1346     .abstract = true,
1347     .class_init = virtio_scsi_common_class_init,
1348 };
1349
1350 static const TypeInfo virtio_scsi_info = {
1351     .name = TYPE_VIRTIO_SCSI,
1352     .parent = TYPE_VIRTIO_SCSI_COMMON,
1353     .instance_size = sizeof(VirtIOSCSI),
1354     .class_init = virtio_scsi_class_init,
1355     .interfaces = (InterfaceInfo[]) {
1356         { TYPE_HOTPLUG_HANDLER },
1357         { }
1358     }
1359 };
1360
1361 static void virtio_register_types(void)
1362 {
1363     type_register_static(&virtio_scsi_common_info);
1364     type_register_static(&virtio_scsi_info);
1365 }
1366
1367 type_init(virtio_register_types)