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/error-report.h"
  22 #include "qemu/iov.h"
  23 #include "qemu/module.h"
  24 #include "sysemu/block-backend.h"
  25 #include "hw/qdev-properties.h"
  26 #include "hw/scsi/scsi.h"
  27 #include "scsi/constants.h"
  28 #include "hw/virtio/virtio-bus.h"
  29 #include "hw/virtio/virtio-access.h"
  30
  31 static inline int virtio_scsi_get_lun(uint8_t *lun)
  32 {
  33     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  34 }
  35
  36 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  37 {
  38     if (lun[0] != 1) {
  39         return NULL;
  40     }
  41     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  42         return NULL;
  43     }
  44     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  45 }
  46
  47 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  48 {
  49     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  50     const size_t zero_skip =
  51         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  52
  53     req->vq = vq;
  54     req->dev = s;
  55     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
  56     qemu_iovec_init(&req->resp_iov, 1);
  57     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  58 }
  59
  60 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  61 {
  62     qemu_iovec_destroy(&req->resp_iov);
  63     qemu_sglist_destroy(&req->qsgl);
  64     g_free(req);
  65 }
  66
  67 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  68 {
  69     VirtIOSCSI *s = req->dev;
  70     VirtQueue *vq = req->vq;
  71     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  72
  73     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  74     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  75     if (s->dataplane_started && !s->dataplane_fenced) {
  76         virtio_notify_irqfd(vdev, vq);
  77     } else {
  78         virtio_notify(vdev, vq);
  79     }
  80
  81     if (req->sreq) {
  82         req->sreq->hba_private = NULL;
  83         scsi_req_unref(req->sreq);
  84     }
  85     virtio_scsi_free_req(req);
  86 }
  87
  88 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
  89 {
  90     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
  91     virtqueue_detach_element(req->vq, &req->elem, 0);
  92     virtio_scsi_free_req(req);
  93 }
  94
  95 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  96                               hwaddr *addr, int num, size_t skip)
  97 {
  98     QEMUSGList *qsgl = &req->qsgl;
  99     size_t copied = 0;
 100
 101     while (num) {
 102         if (skip >= iov->iov_len) {
 103             skip -= iov->iov_len;
 104         } else {
 105             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 106             copied += iov->iov_len - skip;
 107             skip = 0;
 108         }
 109         iov++;
 110         addr++;
 111         num--;
 112     }
 113
 114     assert(skip == 0);
 115     return copied;
 116 }
 117
 118 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 119                                  unsigned req_size, unsigned resp_size)
 120 {
 121     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 122     size_t in_size, out_size;
 123
 124     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 125                    &req->req, req_size) < req_size) {
 126         return -EINVAL;
 127     }
 128
 129     if (qemu_iovec_concat_iov(&req->resp_iov,
 130                               req->elem.in_sg, req->elem.in_num, 0,
 131                               resp_size) < resp_size) {
 132         return -EINVAL;
 133     }
 134
 135     req->resp_size = resp_size;
 136
 137     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 138      * As a workaround, always consider the first buffer as the virtio-scsi
 139      * request/response, making the payload start at the second element
 140      * of the iovec.
 141      *
 142      * The actual length of the response header, stored in req->resp_size,
 143      * does not change.
 144      *
 145      * TODO: always disable this workaround for virtio 1.0 devices.
 146      */
 147     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 148         if (req->elem.out_num) {
 149             req_size = req->elem.out_sg[0].iov_len;
 150         }
 151         if (req->elem.in_num) {
 152             resp_size = req->elem.in_sg[0].iov_len;
 153         }
 154     }
 155
 156     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 157                                &req->elem.out_addr[0], req->elem.out_num,
 158                                req_size);
 159     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 160                               &req->elem.in_addr[0], req->elem.in_num,
 161                               resp_size);
 162
 163     if (out_size && in_size) {
 164         return -ENOTSUP;
 165     }
 166
 167     if (out_size) {
 168         req->mode = SCSI_XFER_TO_DEV;
 169     } else if (in_size) {
 170         req->mode = SCSI_XFER_FROM_DEV;
 171     }
 172
 173     return 0;
 174 }
 175
 176 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 177 {
 178     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 179     VirtIOSCSIReq *req;
 180
 181     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 182     if (!req) {
 183         return NULL;
 184     }
 185     virtio_scsi_init_req(s, vq, req);
 186     return req;
 187 }
 188
 189 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 190 {
 191     VirtIOSCSIReq *req = sreq->hba_private;
 192     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 193     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 194     uint32_t n = virtio_get_queue_index(req->vq) - VIRTIO_SCSI_VQ_NUM_FIXED;
 195
 196     assert(n < vs->conf.num_queues);
 197     qemu_put_be32s(f, &n);
 198     qemu_put_virtqueue_element(vdev, f, &req->elem);
 199 }
 200
 201 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 202 {
 203     SCSIBus *bus = sreq->bus;
 204     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 205     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 206     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 207     VirtIOSCSIReq *req;
 208     uint32_t n;
 209
 210     qemu_get_be32s(f, &n);
 211     assert(n < vs->conf.num_queues);
 212     req = qemu_get_virtqueue_element(vdev, f,
 213                                      sizeof(VirtIOSCSIReq) + vs->cdb_size);
 214     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 215
 216     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 217                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 218         error_report("invalid SCSI request migration data");
 219         exit(1);
 220     }
 221
 222     scsi_req_ref(sreq);
 223     req->sreq = sreq;
 224     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 225         assert(req->sreq->cmd.mode == req->mode);
 226     }
 227     return req;
 228 }
 229
 230 typedef struct {
 231     Notifier        notifier;
 232     VirtIOSCSIReq  *tmf_req;
 233 } VirtIOSCSICancelNotifier;
 234
 235 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 236 {
 237     VirtIOSCSICancelNotifier *n = container_of(notifier,
 238                                                VirtIOSCSICancelNotifier,
 239                                                notifier);
 240
 241     if (--n->tmf_req->remaining == 0) {
 242         virtio_scsi_complete_req(n->tmf_req);
 243     }
 244     g_free(n);
 245 }
 246
 247 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
 248 {
 249     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
 250         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 251     }
 252 }
 253
 254 /* Return 0 if the request is ready to be completed and return to guest;
 255  * -EINPROGRESS if the request is submitted and will be completed later, in the
 256  *  case of async cancellation. */
 257 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 258 {
 259     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 260     SCSIRequest *r, *next;
 261     BusChild *kid;
 262     int target;
 263     int ret = 0;
 264
 265     virtio_scsi_ctx_check(s, d);
 266     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 267     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 268
 269     /*
 270      * req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
 271      * to avoid compiler errors.
 272      */
 273     req->req.tmf.subtype =
 274         virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
 275
 276     switch (req->req.tmf.subtype) {
 277     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 278     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 279         if (!d) {
 280             goto fail;
 281         }
 282         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 283             goto incorrect_lun;
 284         }
 285         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 286             VirtIOSCSIReq *cmd_req = r->hba_private;
 287             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 288                 break;
 289             }
 290         }
 291         if (r) {
 292             /*
 293              * Assert that the request has not been completed yet, we
 294              * check for it in the loop above.
 295              */
 296             assert(r->hba_private);
 297             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 298                 /* "If the specified command is present in the task set, then
 299                  * return a service response set to FUNCTION SUCCEEDED".
 300                  */
 301                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 302             } else {
 303                 VirtIOSCSICancelNotifier *notifier;
 304
 305                 req->remaining = 1;
 306                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 307                 notifier->tmf_req = req;
 308                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 309                 scsi_req_cancel_async(r, &notifier->notifier);
 310                 ret = -EINPROGRESS;
 311             }
 312         }
 313         break;
 314
 315     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 316         if (!d) {
 317             goto fail;
 318         }
 319         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 320             goto incorrect_lun;
 321         }
 322         s->resetting++;
 323         qdev_reset_all(&d->qdev);
 324         s->resetting--;
 325         break;
 326
 327     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 328     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 329     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 330         if (!d) {
 331             goto fail;
 332         }
 333         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 334             goto incorrect_lun;
 335         }
 336
 337         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 338          * This way, if the bus starts calling back to the notifiers
 339          * even before we finish the loop, virtio_scsi_cancel_notify
 340          * will not complete the TMF too early.
 341          */
 342         req->remaining = 1;
 343         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 344             if (r->hba_private) {
 345                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 346                     /* "If there is any command present in the task set, then
 347                      * return a service response set to FUNCTION SUCCEEDED".
 348                      */
 349                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 350                     break;
 351                 } else {
 352                     VirtIOSCSICancelNotifier *notifier;
 353
 354                     req->remaining++;
 355                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 356                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 357                     notifier->tmf_req = req;
 358                     scsi_req_cancel_async(r, &notifier->notifier);
 359                 }
 360             }
 361         }
 362         if (--req->remaining > 0) {
 363             ret = -EINPROGRESS;
 364         }
 365         break;
 366
 367     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 368         target = req->req.tmf.lun[1];
 369         s->resetting++;
 370
 371         rcu_read_lock();
 372         QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
 373              d = SCSI_DEVICE(kid->child);
 374              if (d->channel == 0 && d->id == target) {
 375                 qdev_reset_all(&d->qdev);
 376              }
 377         }
 378         rcu_read_unlock();
 379
 380         s->resetting--;
 381         break;
 382
 383     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 384     default:
 385         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 386         break;
 387     }
 388
 389     return ret;
 390
 391 incorrect_lun:
 392     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 393     return ret;
 394
 395 fail:
 396     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 397     return ret;
 398 }
 399
 400 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 401 {
 402     VirtIODevice *vdev = (VirtIODevice *)s;
 403     uint32_t type;
 404     int r = 0;
 405
 406     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 407                 &type, sizeof(type)) < sizeof(type)) {
 408         virtio_scsi_bad_req(req);
 409         return;
 410     }
 411
 412     virtio_tswap32s(vdev, &type);
 413     if (type == VIRTIO_SCSI_T_TMF) {
 414         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 415                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 416             virtio_scsi_bad_req(req);
 417             return;
 418         } else {
 419             r = virtio_scsi_do_tmf(s, req);
 420         }
 421
 422     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 423                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 424         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 425                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 426             virtio_scsi_bad_req(req);
 427             return;
 428         } else {
 429             req->resp.an.event_actual = 0;
 430             req->resp.an.response = VIRTIO_SCSI_S_OK;
 431         }
 432     }
 433     if (r == 0) {
 434         virtio_scsi_complete_req(req);
 435     } else {
 436         assert(r == -EINPROGRESS);
 437     }
 438 }
 439
 440 bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 441 {
 442     VirtIOSCSIReq *req;
 443     bool progress = false;
 444
 445     while ((req = virtio_scsi_pop_req(s, vq))) {
 446         progress = true;
 447         virtio_scsi_handle_ctrl_req(s, req);
 448     }
 449     return progress;
 450 }
 451
 452 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 453 {
 454     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 455
 456     if (s->ctx) {
 457         virtio_device_start_ioeventfd(vdev);
 458         if (!s->dataplane_fenced) {
 459             return;
 460         }
 461     }
 462     virtio_scsi_acquire(s);
 463     virtio_scsi_handle_ctrl_vq(s, vq);
 464     virtio_scsi_release(s);
 465 }
 466
 467 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 468 {
 469     /* Sense data is not in req->resp and is copied separately
 470      * in virtio_scsi_command_complete.
 471      */
 472     req->resp_size = sizeof(VirtIOSCSICmdResp);
 473     virtio_scsi_complete_req(req);
 474 }
 475
 476 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 477                                          size_t resid)
 478 {
 479     VirtIOSCSIReq *req = r->hba_private;
 480     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 481     uint32_t sense_len;
 482     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 483
 484     if (r->io_canceled) {
 485         return;
 486     }
 487
 488     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 489     req->resp.cmd.status = status;
 490     if (req->resp.cmd.status == GOOD) {
 491         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 492     } else {
 493         req->resp.cmd.resid = 0;
 494         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 495         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 496         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 497                             sense, sense_len);
 498         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 499     }
 500     virtio_scsi_complete_cmd_req(req);
 501 }
 502
 503 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 504                                  uint8_t *buf, void *hba_private)
 505 {
 506     VirtIOSCSIReq *req = hba_private;
 507
 508     if (cmd->len == 0) {
 509         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 510         memcpy(cmd->buf, buf, cmd->len);
 511     }
 512
 513     /* Extract the direction and mode directly from the request, for
 514      * host device passthrough.
 515      */
 516     cmd->xfer = req->qsgl.size;
 517     cmd->mode = req->mode;
 518     return 0;
 519 }
 520
 521 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 522 {
 523     VirtIOSCSIReq *req = r->hba_private;
 524
 525     return &req->qsgl;
 526 }
 527
 528 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 529 {
 530     VirtIOSCSIReq *req = r->hba_private;
 531
 532     if (!req) {
 533         return;
 534     }
 535     if (req->dev->resetting) {
 536         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 537     } else {
 538         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 539     }
 540     virtio_scsi_complete_cmd_req(req);
 541 }
 542
 543 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 544 {
 545     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 546     virtio_scsi_complete_cmd_req(req);
 547 }
 548
 549 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 550 {
 551     VirtIOSCSICommon *vs = &s->parent_obj;
 552     SCSIDevice *d;
 553     int rc;
 554
 555     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 556                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 557     if (rc < 0) {
 558         if (rc == -ENOTSUP) {
 559             virtio_scsi_fail_cmd_req(req);
 560             return -ENOTSUP;
 561         } else {
 562             virtio_scsi_bad_req(req);
 563             return -EINVAL;
 564         }
 565     }
 566
 567     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 568     if (!d) {
 569         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 570         virtio_scsi_complete_cmd_req(req);
 571         return -ENOENT;
 572     }
 573     virtio_scsi_ctx_check(s, d);
 574     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 575                              virtio_scsi_get_lun(req->req.cmd.lun),
 576                              req->req.cmd.cdb, req);
 577
 578     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 579         && (req->sreq->cmd.mode != req->mode ||
 580             req->sreq->cmd.xfer > req->qsgl.size)) {
 581         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 582         virtio_scsi_complete_cmd_req(req);
 583         return -ENOBUFS;
 584     }
 585     scsi_req_ref(req->sreq);
 586     blk_io_plug(d->conf.blk);
 587     return 0;
 588 }
 589
 590 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 591 {
 592     SCSIRequest *sreq = req->sreq;
 593     if (scsi_req_enqueue(sreq)) {
 594         scsi_req_continue(sreq);
 595     }
 596     blk_io_unplug(sreq->dev->conf.blk);
 597     scsi_req_unref(sreq);
 598 }
 599
 600 bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 601 {
 602     VirtIOSCSIReq *req, *next;
 603     int ret = 0;
 604     bool suppress_notifications = virtio_queue_get_notification(vq);
 605     bool progress = false;
 606
 607     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 608
 609     do {
 610         if (suppress_notifications) {
 611             virtio_queue_set_notification(vq, 0);
 612         }
 613
 614         while ((req = virtio_scsi_pop_req(s, vq))) {
 615             progress = true;
 616             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 617             if (!ret) {
 618                 QTAILQ_INSERT_TAIL(&reqs, req, next);
 619             } else if (ret == -EINVAL) {
 620                 /* The device is broken and shouldn't process any request */
 621                 while (!QTAILQ_EMPTY(&reqs)) {
 622                     req = QTAILQ_FIRST(&reqs);
 623                     QTAILQ_REMOVE(&reqs, req, next);
 624                     blk_io_unplug(req->sreq->dev->conf.blk);
 625                     scsi_req_unref(req->sreq);
 626                     virtqueue_detach_element(req->vq, &req->elem, 0);
 627                     virtio_scsi_free_req(req);
 628                 }
 629             }
 630         }
 631
 632         if (suppress_notifications) {
 633             virtio_queue_set_notification(vq, 1);
 634         }
 635     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 636
 637     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 638         virtio_scsi_handle_cmd_req_submit(s, req);
 639     }
 640     return progress;
 641 }
 642
 643 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 644 {
 645     /* use non-QOM casts in the data path */
 646     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 647
 648     if (s->ctx) {
 649         virtio_device_start_ioeventfd(vdev);
 650         if (!s->dataplane_fenced) {
 651             return;
 652         }
 653     }
 654     virtio_scsi_acquire(s);
 655     virtio_scsi_handle_cmd_vq(s, vq);
 656     virtio_scsi_release(s);
 657 }
 658
 659 static void virtio_scsi_get_config(VirtIODevice *vdev,
 660                                    uint8_t *config)
 661 {
 662     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 663     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 664
 665     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 666     virtio_stl_p(vdev, &scsiconf->seg_max,
 667                  s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
 668     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 669     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 670     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 671     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 672     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 673     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 674     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 675     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 676 }
 677
 678 static void virtio_scsi_set_config(VirtIODevice *vdev,
 679                                    const uint8_t *config)
 680 {
 681     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 682     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 683
 684     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 685         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 686         virtio_error(vdev,
 687                      "bad data written to virtio-scsi configuration space");
 688         return;
 689     }
 690
 691     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 692     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 693 }
 694
 695 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 696                                          uint64_t requested_features,
 697                                          Error **errp)
 698 {
 699     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 700
 701     /* Firstly sync all virtio-scsi possible supported features */
 702     requested_features |= s->host_features;
 703     return requested_features;
 704 }
 705
 706 static void virtio_scsi_reset(VirtIODevice *vdev)
 707 {
 708     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 709     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 710
 711     assert(!s->dataplane_started);
 712     s->resetting++;
 713     qbus_reset_all(BUS(&s->bus));
 714     s->resetting--;
 715
 716     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 717     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 718     s->events_dropped = false;
 719 }
 720
 721 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 722                             uint32_t event, uint32_t reason)
 723 {
 724     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 725     VirtIOSCSIReq *req;
 726     VirtIOSCSIEvent *evt;
 727     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 728
 729     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 730         return;
 731     }
 732
 733     req = virtio_scsi_pop_req(s, vs->event_vq);
 734     if (!req) {
 735         s->events_dropped = true;
 736         return;
 737     }
 738
 739     if (s->events_dropped) {
 740         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 741         s->events_dropped = false;
 742     }
 743
 744     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 745         virtio_scsi_bad_req(req);
 746         return;
 747     }
 748
 749     evt = &req->resp.event;
 750     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 751     evt->event = virtio_tswap32(vdev, event);
 752     evt->reason = virtio_tswap32(vdev, reason);
 753     if (!dev) {
 754         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 755     } else {
 756         evt->lun[0] = 1;
 757         evt->lun[1] = dev->id;
 758
 759         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 760         if (dev->lun >= 256) {
 761             evt->lun[2] = (dev->lun >> 8) | 0x40;
 762         }
 763         evt->lun[3] = dev->lun & 0xFF;
 764     }
 765     virtio_scsi_complete_req(req);
 766 }
 767
 768 bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 769 {
 770     if (s->events_dropped) {
 771         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 772         return true;
 773     }
 774     return false;
 775 }
 776
 777 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 778 {
 779     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 780
 781     if (s->ctx) {
 782         virtio_device_start_ioeventfd(vdev);
 783         if (!s->dataplane_fenced) {
 784             return;
 785         }
 786     }
 787     virtio_scsi_acquire(s);
 788     virtio_scsi_handle_event_vq(s, vq);
 789     virtio_scsi_release(s);
 790 }
 791
 792 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 793 {
 794     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 795     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 796
 797     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 798         dev->type != TYPE_ROM) {
 799         virtio_scsi_acquire(s);
 800         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 801                                sense.asc | (sense.ascq << 8));
 802         virtio_scsi_release(s);
 803     }
 804 }
 805
 806 static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
 807                                     DeviceState *dev, Error **errp)
 808 {
 809     SCSIDevice *sd = SCSI_DEVICE(dev);
 810     sd->hba_supports_iothread = true;
 811 }
 812
 813 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 814                                 Error **errp)
 815 {
 816     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 817     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 818     SCSIDevice *sd = SCSI_DEVICE(dev);
 819     int ret;
 820
 821     if (s->ctx && !s->dataplane_fenced) {
 822         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 823             return;
 824         }
 825         virtio_scsi_acquire(s);
 826         ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
 827         virtio_scsi_release(s);
 828         if (ret < 0) {
 829             return;
 830         }
 831     }
 832
 833     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 834         virtio_scsi_acquire(s);
 835         virtio_scsi_push_event(s, sd,
 836                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 837                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 838         virtio_scsi_release(s);
 839     }
 840 }
 841
 842 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 843                                   Error **errp)
 844 {
 845     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 846     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 847     SCSIDevice *sd = SCSI_DEVICE(dev);
 848     AioContext *ctx = s->ctx ?: qemu_get_aio_context();
 849
 850     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 851         virtio_scsi_acquire(s);
 852         virtio_scsi_push_event(s, sd,
 853                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 854                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 855         virtio_scsi_release(s);
 856     }
 857
 858     aio_disable_external(ctx);
 859     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 860     aio_enable_external(ctx);
 861
 862     if (s->ctx) {
 863         virtio_scsi_acquire(s);
 864         /* If other users keep the BlockBackend in the iothread, that's ok */
 865         blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
 866         virtio_scsi_release(s);
 867     }
 868 }
 869
 870 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 871     .tcq = true,
 872     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 873     .max_target = VIRTIO_SCSI_MAX_TARGET,
 874     .max_lun = VIRTIO_SCSI_MAX_LUN,
 875
 876     .complete = virtio_scsi_command_complete,
 877     .cancel = virtio_scsi_request_cancelled,
 878     .change = virtio_scsi_change,
 879     .parse_cdb = virtio_scsi_parse_cdb,
 880     .get_sg_list = virtio_scsi_get_sg_list,
 881     .save_request = virtio_scsi_save_request,
 882     .load_request = virtio_scsi_load_request,
 883 };
 884
 885 void virtio_scsi_common_realize(DeviceState *dev,
 886                                 VirtIOHandleOutput ctrl,
 887                                 VirtIOHandleOutput evt,
 888                                 VirtIOHandleOutput cmd,
 889                                 Error **errp)
 890 {
 891     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 892     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 893     int i;
 894
 895     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 896                 sizeof(VirtIOSCSIConfig));
 897
 898     if (s->conf.num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
 899         s->conf.num_queues = 1;
 900     }
 901     if (s->conf.num_queues == 0 ||
 902             s->conf.num_queues > VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED) {
 903         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 904                          "must be a positive integer less than %d.",
 905                    s->conf.num_queues,
 906                    VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED);
 907         virtio_cleanup(vdev);
 908         return;
 909     }
 910     if (s->conf.virtqueue_size <= 2) {
 911         error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
 912                    "must be > 2", s->conf.virtqueue_size);
 913         return;
 914     }
 915     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 916     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 917     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 918
 919     s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
 920     s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
 921     for (i = 0; i < s->conf.num_queues; i++) {
 922         s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
 923     }
 924 }
 925
 926 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 927 {
 928     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 929     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 930     Error *err = NULL;
 931
 932     virtio_scsi_common_realize(dev,
 933                                virtio_scsi_handle_ctrl,
 934                                virtio_scsi_handle_event,
 935                                virtio_scsi_handle_cmd,
 936                                &err);
 937     if (err != NULL) {
 938         error_propagate(errp, err);
 939         return;
 940     }
 941
 942     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 943                  &virtio_scsi_scsi_info, vdev->bus_name);
 944     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 945     qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev));
 946
 947     virtio_scsi_dataplane_setup(s, errp);
 948 }
 949
 950 void virtio_scsi_common_unrealize(DeviceState *dev)
 951 {
 952     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 953     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 954     int i;
 955
 956     virtio_delete_queue(vs->ctrl_vq);
 957     virtio_delete_queue(vs->event_vq);
 958     for (i = 0; i < vs->conf.num_queues; i++) {
 959         virtio_delete_queue(vs->cmd_vqs[i]);
 960     }
 961     g_free(vs->cmd_vqs);
 962     virtio_cleanup(vdev);
 963 }
 964
 965 static void virtio_scsi_device_unrealize(DeviceState *dev)
 966 {
 967     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 968
 969     qbus_set_hotplug_handler(BUS(&s->bus), NULL);
 970     virtio_scsi_common_unrealize(dev);
 971 }
 972
 973 static Property virtio_scsi_properties[] = {
 974     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues,
 975                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
 976     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
 977                                          parent_obj.conf.virtqueue_size, 256),
 978     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
 979                       parent_obj.conf.seg_max_adjust, true),
 980     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 981                                                   0xFFFF),
 982     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 983                                                   128),
 984     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 985                                            VIRTIO_SCSI_F_HOTPLUG, true),
 986     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 987                                                 VIRTIO_SCSI_F_CHANGE, true),
 988     DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
 989                      TYPE_IOTHREAD, IOThread *),
 990     DEFINE_PROP_END_OF_LIST(),
 991 };
 992
 993 static const VMStateDescription vmstate_virtio_scsi = {
 994     .name = "virtio-scsi",
 995     .minimum_version_id = 1,
 996     .version_id = 1,
 997     .fields = (VMStateField[]) {
 998         VMSTATE_VIRTIO_DEVICE,
 999         VMSTATE_END_OF_LIST()
1000     },
1001 };
1002
1003 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
1004 {
1005     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1006     DeviceClass *dc = DEVICE_CLASS(klass);
1007
1008     vdc->get_config = virtio_scsi_get_config;
1009     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1010 }
1011
1012 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
1013 {
1014     DeviceClass *dc = DEVICE_CLASS(klass);
1015     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1016     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1017
1018     device_class_set_props(dc, virtio_scsi_properties);
1019     dc->vmsd = &vmstate_virtio_scsi;
1020     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1021     vdc->realize = virtio_scsi_device_realize;
1022     vdc->unrealize = virtio_scsi_device_unrealize;
1023     vdc->set_config = virtio_scsi_set_config;
1024     vdc->get_features = virtio_scsi_get_features;
1025     vdc->reset = virtio_scsi_reset;
1026     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
1027     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
1028     hc->pre_plug = virtio_scsi_pre_hotplug;
1029     hc->plug = virtio_scsi_hotplug;
1030     hc->unplug = virtio_scsi_hotunplug;
1031 }
1032
1033 static const TypeInfo virtio_scsi_common_info = {
1034     .name = TYPE_VIRTIO_SCSI_COMMON,
1035     .parent = TYPE_VIRTIO_DEVICE,
1036     .instance_size = sizeof(VirtIOSCSICommon),
1037     .abstract = true,
1038     .class_init = virtio_scsi_common_class_init,
1039 };
1040
1041 static const TypeInfo virtio_scsi_info = {
1042     .name = TYPE_VIRTIO_SCSI,
1043     .parent = TYPE_VIRTIO_SCSI_COMMON,
1044     .instance_size = sizeof(VirtIOSCSI),
1045     .class_init = virtio_scsi_class_init,
1046     .interfaces = (InterfaceInfo[]) {
1047         { TYPE_HOTPLUG_HANDLER },
1048         { }
1049     }
1050 };
1051
1052 static void virtio_register_types(void)
1053 {
1054     type_register_static(&virtio_scsi_common_info);
1055     type_register_static(&virtio_scsi_info);
1056 }
1057
1058 type_init(virtio_register_types)