hw/scsi/virtio-scsi.c

   1 /*
   2  * Virtio SCSI HBA
   3  *
   4  * Copyright IBM, Corp. 2010
   5  * Copyright Red Hat, Inc. 2011
   6  *
   7  * Authors:
   8  *   Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
   9  *   Paolo Bonzini      <pbonzini@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include "qemu/osdep.h"
  17 #include "qapi/error.h"
  18 #include "standard-headers/linux/virtio_ids.h"
  19 #include "hw/virtio/virtio-scsi.h"
  20 #include "qemu/error-report.h"
  21 #include "qemu/iov.h"
  22 #include "sysemu/block-backend.h"
  23 #include "hw/scsi/scsi.h"
  24 #include "scsi/constants.h"
  25 #include "hw/virtio/virtio-bus.h"
  26 #include "hw/virtio/virtio-access.h"
  27
  28 static inline int virtio_scsi_get_lun(uint8_t *lun)
  29 {
  30     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  31 }
  32
  33 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  34 {
  35     if (lun[0] != 1) {
  36         return NULL;
  37     }
  38     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  39         return NULL;
  40     }
  41     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  42 }
  43
  44 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  45 {
  46     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  47     const size_t zero_skip =
  48         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  49
  50     req->vq = vq;
  51     req->dev = s;
  52     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
  53     qemu_iovec_init(&req->resp_iov, 1);
  54     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  55 }
  56
  57 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  58 {
  59     qemu_iovec_destroy(&req->resp_iov);
  60     qemu_sglist_destroy(&req->qsgl);
  61     g_free(req);
  62 }
  63
  64 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  65 {
  66     VirtIOSCSI *s = req->dev;
  67     VirtQueue *vq = req->vq;
  68     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  69
  70     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  71     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  72     if (s->dataplane_started && !s->dataplane_fenced) {
  73         virtio_notify_irqfd(vdev, vq);
  74     } else {
  75         virtio_notify(vdev, vq);
  76     }
  77
  78     if (req->sreq) {
  79         req->sreq->hba_private = NULL;
  80         scsi_req_unref(req->sreq);
  81     }
  82     virtio_scsi_free_req(req);
  83 }
  84
  85 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
  86 {
  87     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
  88     virtqueue_detach_element(req->vq, &req->elem, 0);
  89     virtio_scsi_free_req(req);
  90 }
  91
  92 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  93                               hwaddr *addr, int num, size_t skip)
  94 {
  95     QEMUSGList *qsgl = &req->qsgl;
  96     size_t copied = 0;
  97
  98     while (num) {
  99         if (skip >= iov->iov_len) {
 100             skip -= iov->iov_len;
 101         } else {
 102             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 103             copied += iov->iov_len - skip;
 104             skip = 0;
 105         }
 106         iov++;
 107         addr++;
 108         num--;
 109     }
 110
 111     assert(skip == 0);
 112     return copied;
 113 }
 114
 115 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 116                                  unsigned req_size, unsigned resp_size)
 117 {
 118     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 119     size_t in_size, out_size;
 120
 121     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 122                    &req->req, req_size) < req_size) {
 123         return -EINVAL;
 124     }
 125
 126     if (qemu_iovec_concat_iov(&req->resp_iov,
 127                               req->elem.in_sg, req->elem.in_num, 0,
 128                               resp_size) < resp_size) {
 129         return -EINVAL;
 130     }
 131
 132     req->resp_size = resp_size;
 133
 134     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 135      * As a workaround, always consider the first buffer as the virtio-scsi
 136      * request/response, making the payload start at the second element
 137      * of the iovec.
 138      *
 139      * The actual length of the response header, stored in req->resp_size,
 140      * does not change.
 141      *
 142      * TODO: always disable this workaround for virtio 1.0 devices.
 143      */
 144     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 145         if (req->elem.out_num) {
 146             req_size = req->elem.out_sg[0].iov_len;
 147         }
 148         if (req->elem.in_num) {
 149             resp_size = req->elem.in_sg[0].iov_len;
 150         }
 151     }
 152
 153     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 154                                &req->elem.out_addr[0], req->elem.out_num,
 155                                req_size);
 156     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 157                               &req->elem.in_addr[0], req->elem.in_num,
 158                               resp_size);
 159
 160     if (out_size && in_size) {
 161         return -ENOTSUP;
 162     }
 163
 164     if (out_size) {
 165         req->mode = SCSI_XFER_TO_DEV;
 166     } else if (in_size) {
 167         req->mode = SCSI_XFER_FROM_DEV;
 168     }
 169
 170     return 0;
 171 }
 172
 173 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 174 {
 175     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 176     VirtIOSCSIReq *req;
 177
 178     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 179     if (!req) {
 180         return NULL;
 181     }
 182     virtio_scsi_init_req(s, vq, req);
 183     return req;
 184 }
 185
 186 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 187 {
 188     VirtIOSCSIReq *req = sreq->hba_private;
 189     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 190     uint32_t n = virtio_get_queue_index(req->vq) - 2;
 191
 192     assert(n < vs->conf.num_queues);
 193     qemu_put_be32s(f, &n);
 194     qemu_put_virtqueue_element(f, &req->elem);
 195 }
 196
 197 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 198 {
 199     SCSIBus *bus = sreq->bus;
 200     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 201     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 202     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 203     VirtIOSCSIReq *req;
 204     uint32_t n;
 205
 206     qemu_get_be32s(f, &n);
 207     assert(n < vs->conf.num_queues);
 208     req = qemu_get_virtqueue_element(vdev, f,
 209                                      sizeof(VirtIOSCSIReq) + vs->cdb_size);
 210     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 211
 212     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 213                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 214         error_report("invalid SCSI request migration data");
 215         exit(1);
 216     }
 217
 218     scsi_req_ref(sreq);
 219     req->sreq = sreq;
 220     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 221         assert(req->sreq->cmd.mode == req->mode);
 222     }
 223     return req;
 224 }
 225
 226 typedef struct {
 227     Notifier        notifier;
 228     VirtIOSCSIReq  *tmf_req;
 229 } VirtIOSCSICancelNotifier;
 230
 231 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 232 {
 233     VirtIOSCSICancelNotifier *n = container_of(notifier,
 234                                                VirtIOSCSICancelNotifier,
 235                                                notifier);
 236
 237     if (--n->tmf_req->remaining == 0) {
 238         virtio_scsi_complete_req(n->tmf_req);
 239     }
 240     g_free(n);
 241 }
 242
 243 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
 244 {
 245     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
 246         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 247     }
 248 }
 249
 250 /* Return 0 if the request is ready to be completed and return to guest;
 251  * -EINPROGRESS if the request is submitted and will be completed later, in the
 252  *  case of async cancellation. */
 253 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 254 {
 255     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 256     SCSIRequest *r, *next;
 257     BusChild *kid;
 258     int target;
 259     int ret = 0;
 260
 261     virtio_scsi_ctx_check(s, d);
 262     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 263     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 264
 265     /*
 266      * req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
 267      * to avoid compiler errors.
 268      */
 269     req->req.tmf.subtype =
 270         virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
 271
 272     switch (req->req.tmf.subtype) {
 273     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 274     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 275         if (!d) {
 276             goto fail;
 277         }
 278         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 279             goto incorrect_lun;
 280         }
 281         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 282             VirtIOSCSIReq *cmd_req = r->hba_private;
 283             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 284                 break;
 285             }
 286         }
 287         if (r) {
 288             /*
 289              * Assert that the request has not been completed yet, we
 290              * check for it in the loop above.
 291              */
 292             assert(r->hba_private);
 293             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 294                 /* "If the specified command is present in the task set, then
 295                  * return a service response set to FUNCTION SUCCEEDED".
 296                  */
 297                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 298             } else {
 299                 VirtIOSCSICancelNotifier *notifier;
 300
 301                 req->remaining = 1;
 302                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 303                 notifier->tmf_req = req;
 304                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 305                 scsi_req_cancel_async(r, &notifier->notifier);
 306                 ret = -EINPROGRESS;
 307             }
 308         }
 309         break;
 310
 311     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 312         if (!d) {
 313             goto fail;
 314         }
 315         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 316             goto incorrect_lun;
 317         }
 318         s->resetting++;
 319         qdev_reset_all(&d->qdev);
 320         s->resetting--;
 321         break;
 322
 323     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 324     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 325     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 326         if (!d) {
 327             goto fail;
 328         }
 329         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 330             goto incorrect_lun;
 331         }
 332
 333         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 334          * This way, if the bus starts calling back to the notifiers
 335          * even before we finish the loop, virtio_scsi_cancel_notify
 336          * will not complete the TMF too early.
 337          */
 338         req->remaining = 1;
 339         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 340             if (r->hba_private) {
 341                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 342                     /* "If there is any command present in the task set, then
 343                      * return a service response set to FUNCTION SUCCEEDED".
 344                      */
 345                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 346                     break;
 347                 } else {
 348                     VirtIOSCSICancelNotifier *notifier;
 349
 350                     req->remaining++;
 351                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 352                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 353                     notifier->tmf_req = req;
 354                     scsi_req_cancel_async(r, &notifier->notifier);
 355                 }
 356             }
 357         }
 358         if (--req->remaining > 0) {
 359             ret = -EINPROGRESS;
 360         }
 361         break;
 362
 363     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 364         target = req->req.tmf.lun[1];
 365         s->resetting++;
 366         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 367              d = SCSI_DEVICE(kid->child);
 368              if (d->channel == 0 && d->id == target) {
 369                 qdev_reset_all(&d->qdev);
 370              }
 371         }
 372         s->resetting--;
 373         break;
 374
 375     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 376     default:
 377         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 378         break;
 379     }
 380
 381     return ret;
 382
 383 incorrect_lun:
 384     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 385     return ret;
 386
 387 fail:
 388     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 389     return ret;
 390 }
 391
 392 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 393 {
 394     VirtIODevice *vdev = (VirtIODevice *)s;
 395     uint32_t type;
 396     int r = 0;
 397
 398     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 399                 &type, sizeof(type)) < sizeof(type)) {
 400         virtio_scsi_bad_req(req);
 401         return;
 402     }
 403
 404     virtio_tswap32s(vdev, &type);
 405     if (type == VIRTIO_SCSI_T_TMF) {
 406         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 407                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 408             virtio_scsi_bad_req(req);
 409             return;
 410         } else {
 411             r = virtio_scsi_do_tmf(s, req);
 412         }
 413
 414     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 415                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 416         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 417                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 418             virtio_scsi_bad_req(req);
 419             return;
 420         } else {
 421             req->resp.an.event_actual = 0;
 422             req->resp.an.response = VIRTIO_SCSI_S_OK;
 423         }
 424     }
 425     if (r == 0) {
 426         virtio_scsi_complete_req(req);
 427     } else {
 428         assert(r == -EINPROGRESS);
 429     }
 430 }
 431
 432 bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 433 {
 434     VirtIOSCSIReq *req;
 435     bool progress = false;
 436
 437     while ((req = virtio_scsi_pop_req(s, vq))) {
 438         progress = true;
 439         virtio_scsi_handle_ctrl_req(s, req);
 440     }
 441     return progress;
 442 }
 443
 444 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 445 {
 446     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 447
 448     if (s->ctx) {
 449         virtio_device_start_ioeventfd(vdev);
 450         if (!s->dataplane_fenced) {
 451             return;
 452         }
 453     }
 454     virtio_scsi_acquire(s);
 455     virtio_scsi_handle_ctrl_vq(s, vq);
 456     virtio_scsi_release(s);
 457 }
 458
 459 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 460 {
 461     /* Sense data is not in req->resp and is copied separately
 462      * in virtio_scsi_command_complete.
 463      */
 464     req->resp_size = sizeof(VirtIOSCSICmdResp);
 465     virtio_scsi_complete_req(req);
 466 }
 467
 468 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 469                                          size_t resid)
 470 {
 471     VirtIOSCSIReq *req = r->hba_private;
 472     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 473     uint32_t sense_len;
 474     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 475
 476     if (r->io_canceled) {
 477         return;
 478     }
 479
 480     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 481     req->resp.cmd.status = status;
 482     if (req->resp.cmd.status == GOOD) {
 483         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 484     } else {
 485         req->resp.cmd.resid = 0;
 486         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 487         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 488         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 489                             sense, sense_len);
 490         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 491     }
 492     virtio_scsi_complete_cmd_req(req);
 493 }
 494
 495 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 496                                  uint8_t *buf, void *hba_private)
 497 {
 498     VirtIOSCSIReq *req = hba_private;
 499
 500     if (cmd->len == 0) {
 501         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 502         memcpy(cmd->buf, buf, cmd->len);
 503     }
 504
 505     /* Extract the direction and mode directly from the request, for
 506      * host device passthrough.
 507      */
 508     cmd->xfer = req->qsgl.size;
 509     cmd->mode = req->mode;
 510     return 0;
 511 }
 512
 513 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 514 {
 515     VirtIOSCSIReq *req = r->hba_private;
 516
 517     return &req->qsgl;
 518 }
 519
 520 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 521 {
 522     VirtIOSCSIReq *req = r->hba_private;
 523
 524     if (!req) {
 525         return;
 526     }
 527     if (req->dev->resetting) {
 528         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 529     } else {
 530         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 531     }
 532     virtio_scsi_complete_cmd_req(req);
 533 }
 534
 535 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 536 {
 537     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 538     virtio_scsi_complete_cmd_req(req);
 539 }
 540
 541 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 542 {
 543     VirtIOSCSICommon *vs = &s->parent_obj;
 544     SCSIDevice *d;
 545     int rc;
 546
 547     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 548                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 549     if (rc < 0) {
 550         if (rc == -ENOTSUP) {
 551             virtio_scsi_fail_cmd_req(req);
 552             return -ENOTSUP;
 553         } else {
 554             virtio_scsi_bad_req(req);
 555             return -EINVAL;
 556         }
 557     }
 558
 559     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 560     if (!d) {
 561         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 562         virtio_scsi_complete_cmd_req(req);
 563         return -ENOENT;
 564     }
 565     virtio_scsi_ctx_check(s, d);
 566     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 567                              virtio_scsi_get_lun(req->req.cmd.lun),
 568                              req->req.cmd.cdb, req);
 569
 570     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 571         && (req->sreq->cmd.mode != req->mode ||
 572             req->sreq->cmd.xfer > req->qsgl.size)) {
 573         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 574         virtio_scsi_complete_cmd_req(req);
 575         return -ENOBUFS;
 576     }
 577     scsi_req_ref(req->sreq);
 578     blk_io_plug(d->conf.blk);
 579     return 0;
 580 }
 581
 582 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 583 {
 584     SCSIRequest *sreq = req->sreq;
 585     if (scsi_req_enqueue(sreq)) {
 586         scsi_req_continue(sreq);
 587     }
 588     blk_io_unplug(sreq->dev->conf.blk);
 589     scsi_req_unref(sreq);
 590 }
 591
 592 bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 593 {
 594     VirtIOSCSIReq *req, *next;
 595     int ret = 0;
 596     bool progress = false;
 597
 598     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 599
 600     do {
 601         virtio_queue_set_notification(vq, 0);
 602
 603         while ((req = virtio_scsi_pop_req(s, vq))) {
 604             progress = true;
 605             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 606             if (!ret) {
 607                 QTAILQ_INSERT_TAIL(&reqs, req, next);
 608             } else if (ret == -EINVAL) {
 609                 /* The device is broken and shouldn't process any request */
 610                 while (!QTAILQ_EMPTY(&reqs)) {
 611                     req = QTAILQ_FIRST(&reqs);
 612                     QTAILQ_REMOVE(&reqs, req, next);
 613                     blk_io_unplug(req->sreq->dev->conf.blk);
 614                     scsi_req_unref(req->sreq);
 615                     virtqueue_detach_element(req->vq, &req->elem, 0);
 616                     virtio_scsi_free_req(req);
 617                 }
 618             }
 619         }
 620
 621         virtio_queue_set_notification(vq, 1);
 622     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 623
 624     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 625         virtio_scsi_handle_cmd_req_submit(s, req);
 626     }
 627     return progress;
 628 }
 629
 630 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 631 {
 632     /* use non-QOM casts in the data path */
 633     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 634
 635     if (s->ctx) {
 636         virtio_device_start_ioeventfd(vdev);
 637         if (!s->dataplane_fenced) {
 638             return;
 639         }
 640     }
 641     virtio_scsi_acquire(s);
 642     virtio_scsi_handle_cmd_vq(s, vq);
 643     virtio_scsi_release(s);
 644 }
 645
 646 static void virtio_scsi_get_config(VirtIODevice *vdev,
 647                                    uint8_t *config)
 648 {
 649     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 650     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 651
 652     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 653     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 654     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 655     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 656     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 657     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 658     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 659     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 660     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 661     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 662 }
 663
 664 static void virtio_scsi_set_config(VirtIODevice *vdev,
 665                                    const uint8_t *config)
 666 {
 667     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 668     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 669
 670     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 671         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 672         virtio_error(vdev,
 673                      "bad data written to virtio-scsi configuration space");
 674         return;
 675     }
 676
 677     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 678     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 679 }
 680
 681 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 682                                          uint64_t requested_features,
 683                                          Error **errp)
 684 {
 685     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 686
 687     /* Firstly sync all virtio-scsi possible supported features */
 688     requested_features |= s->host_features;
 689     return requested_features;
 690 }
 691
 692 static void virtio_scsi_reset(VirtIODevice *vdev)
 693 {
 694     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 695     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 696
 697     assert(!s->dataplane_started);
 698     s->resetting++;
 699     qbus_reset_all(&s->bus.qbus);
 700     s->resetting--;
 701
 702     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 703     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 704     s->events_dropped = false;
 705 }
 706
 707 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 708                             uint32_t event, uint32_t reason)
 709 {
 710     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 711     VirtIOSCSIReq *req;
 712     VirtIOSCSIEvent *evt;
 713     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 714
 715     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 716         return;
 717     }
 718
 719     req = virtio_scsi_pop_req(s, vs->event_vq);
 720     if (!req) {
 721         s->events_dropped = true;
 722         return;
 723     }
 724
 725     if (s->events_dropped) {
 726         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 727         s->events_dropped = false;
 728     }
 729
 730     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 731         virtio_scsi_bad_req(req);
 732         return;
 733     }
 734
 735     evt = &req->resp.event;
 736     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 737     evt->event = virtio_tswap32(vdev, event);
 738     evt->reason = virtio_tswap32(vdev, reason);
 739     if (!dev) {
 740         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 741     } else {
 742         evt->lun[0] = 1;
 743         evt->lun[1] = dev->id;
 744
 745         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 746         if (dev->lun >= 256) {
 747             evt->lun[2] = (dev->lun >> 8) | 0x40;
 748         }
 749         evt->lun[3] = dev->lun & 0xFF;
 750     }
 751     virtio_scsi_complete_req(req);
 752 }
 753
 754 bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 755 {
 756     if (s->events_dropped) {
 757         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 758         return true;
 759     }
 760     return false;
 761 }
 762
 763 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 764 {
 765     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 766
 767     if (s->ctx) {
 768         virtio_device_start_ioeventfd(vdev);
 769         if (!s->dataplane_fenced) {
 770             return;
 771         }
 772     }
 773     virtio_scsi_acquire(s);
 774     virtio_scsi_handle_event_vq(s, vq);
 775     virtio_scsi_release(s);
 776 }
 777
 778 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 779 {
 780     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 781     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 782
 783     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 784         dev->type != TYPE_ROM) {
 785         virtio_scsi_acquire(s);
 786         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 787                                sense.asc | (sense.ascq << 8));
 788         virtio_scsi_release(s);
 789     }
 790 }
 791
 792 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 793                                 Error **errp)
 794 {
 795     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 796     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 797     SCSIDevice *sd = SCSI_DEVICE(dev);
 798
 799     if (s->ctx && !s->dataplane_fenced) {
 800         AioContext *ctx;
 801         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 802             return;
 803         }
 804         ctx = blk_get_aio_context(sd->conf.blk);
 805         if (ctx != s->ctx && ctx != qemu_get_aio_context()) {
 806             error_setg(errp, "Cannot attach a blockdev that is using "
 807                        "a different iothread");
 808             return;
 809         }
 810         virtio_scsi_acquire(s);
 811         blk_set_aio_context(sd->conf.blk, s->ctx);
 812         virtio_scsi_release(s);
 813
 814     }
 815
 816     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 817         virtio_scsi_acquire(s);
 818         virtio_scsi_push_event(s, sd,
 819                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 820                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 821         virtio_scsi_release(s);
 822     }
 823 }
 824
 825 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 826                                   Error **errp)
 827 {
 828     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 829     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 830     SCSIDevice *sd = SCSI_DEVICE(dev);
 831
 832     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 833         virtio_scsi_acquire(s);
 834         virtio_scsi_push_event(s, sd,
 835                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 836                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 837         virtio_scsi_release(s);
 838     }
 839
 840     if (s->ctx) {
 841         virtio_scsi_acquire(s);
 842         blk_set_aio_context(sd->conf.blk, qemu_get_aio_context());
 843         virtio_scsi_release(s);
 844     }
 845
 846     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 847 }
 848
 849 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 850     .tcq = true,
 851     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 852     .max_target = VIRTIO_SCSI_MAX_TARGET,
 853     .max_lun = VIRTIO_SCSI_MAX_LUN,
 854
 855     .complete = virtio_scsi_command_complete,
 856     .cancel = virtio_scsi_request_cancelled,
 857     .change = virtio_scsi_change,
 858     .parse_cdb = virtio_scsi_parse_cdb,
 859     .get_sg_list = virtio_scsi_get_sg_list,
 860     .save_request = virtio_scsi_save_request,
 861     .load_request = virtio_scsi_load_request,
 862 };
 863
 864 void virtio_scsi_common_realize(DeviceState *dev,
 865                                 VirtIOHandleOutput ctrl,
 866                                 VirtIOHandleOutput evt,
 867                                 VirtIOHandleOutput cmd,
 868                                 Error **errp)
 869 {
 870     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 871     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 872     int i;
 873
 874     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 875                 sizeof(VirtIOSCSIConfig));
 876
 877     if (s->conf.num_queues == 0 ||
 878             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 879         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 880                          "must be a positive integer less than %d.",
 881                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 882         virtio_cleanup(vdev);
 883         return;
 884     }
 885     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 886     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 887     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 888
 889     s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
 890     s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
 891     for (i = 0; i < s->conf.num_queues; i++) {
 892         s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
 893     }
 894 }
 895
 896 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 897 {
 898     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 899     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 900     Error *err = NULL;
 901
 902     virtio_scsi_common_realize(dev,
 903                                virtio_scsi_handle_ctrl,
 904                                virtio_scsi_handle_event,
 905                                virtio_scsi_handle_cmd,
 906                                &err);
 907     if (err != NULL) {
 908         error_propagate(errp, err);
 909         return;
 910     }
 911
 912     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 913                  &virtio_scsi_scsi_info, vdev->bus_name);
 914     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 915     qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev), &error_abort);
 916
 917     virtio_scsi_dataplane_setup(s, errp);
 918 }
 919
 920 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 921 {
 922     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 923     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 924
 925     g_free(vs->cmd_vqs);
 926     virtio_cleanup(vdev);
 927 }
 928
 929 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 930 {
 931     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 932
 933     qbus_set_hotplug_handler(BUS(&s->bus), NULL, &error_abort);
 934     virtio_scsi_common_unrealize(dev, errp);
 935 }
 936
 937 static Property virtio_scsi_properties[] = {
 938     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 939     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
 940                                          parent_obj.conf.virtqueue_size, 128),
 941     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 942                                                   0xFFFF),
 943     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 944                                                   128),
 945     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 946                                            VIRTIO_SCSI_F_HOTPLUG, true),
 947     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 948                                                 VIRTIO_SCSI_F_CHANGE, true),
 949     DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
 950                      TYPE_IOTHREAD, IOThread *),
 951     DEFINE_PROP_END_OF_LIST(),
 952 };
 953
 954 static const VMStateDescription vmstate_virtio_scsi = {
 955     .name = "virtio-scsi",
 956     .minimum_version_id = 1,
 957     .version_id = 1,
 958     .fields = (VMStateField[]) {
 959         VMSTATE_VIRTIO_DEVICE,
 960         VMSTATE_END_OF_LIST()
 961     },
 962 };
 963
 964 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 965 {
 966     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 967     DeviceClass *dc = DEVICE_CLASS(klass);
 968
 969     vdc->get_config = virtio_scsi_get_config;
 970     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 971 }
 972
 973 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 974 {
 975     DeviceClass *dc = DEVICE_CLASS(klass);
 976     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 977     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 978
 979     dc->props = virtio_scsi_properties;
 980     dc->vmsd = &vmstate_virtio_scsi;
 981     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 982     vdc->realize = virtio_scsi_device_realize;
 983     vdc->unrealize = virtio_scsi_device_unrealize;
 984     vdc->set_config = virtio_scsi_set_config;
 985     vdc->get_features = virtio_scsi_get_features;
 986     vdc->reset = virtio_scsi_reset;
 987     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
 988     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
 989     hc->plug = virtio_scsi_hotplug;
 990     hc->unplug = virtio_scsi_hotunplug;
 991 }
 992
 993 static const TypeInfo virtio_scsi_common_info = {
 994     .name = TYPE_VIRTIO_SCSI_COMMON,
 995     .parent = TYPE_VIRTIO_DEVICE,
 996     .instance_size = sizeof(VirtIOSCSICommon),
 997     .abstract = true,
 998     .class_init = virtio_scsi_common_class_init,
 999 };
1000
1001 static const TypeInfo virtio_scsi_info = {
1002     .name = TYPE_VIRTIO_SCSI,
1003     .parent = TYPE_VIRTIO_SCSI_COMMON,
1004     .instance_size = sizeof(VirtIOSCSI),
1005     .class_init = virtio_scsi_class_init,
1006     .interfaces = (InterfaceInfo[]) {
1007         { TYPE_HOTPLUG_HANDLER },
1008         { }
1009     }
1010 };
1011
1012 static void virtio_register_types(void)
1013 {
1014     type_register_static(&virtio_scsi_common_info);
1015     type_register_static(&virtio_scsi_info);
1016 }
1017
1018 type_init(virtio_register_types)