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 "standard-headers/linux/virtio_ids.h"
  17 #include "hw/virtio/virtio-scsi.h"
  18 #include "qemu/error-report.h"
  19 #include "qemu/iov.h"
  20 #include "sysemu/block-backend.h"
  21 #include <hw/scsi/scsi.h>
  22 #include <block/scsi.h>
  23 #include <hw/virtio/virtio-bus.h>
  24 #include "hw/virtio/virtio-access.h"
  25 #include "migration/migration.h"
  26
  27 static inline int virtio_scsi_get_lun(uint8_t *lun)
  28 {
  29     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  30 }
  31
  32 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  33 {
  34     if (lun[0] != 1) {
  35         return NULL;
  36     }
  37     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  38         return NULL;
  39     }
  40     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  41 }
  42
  43 VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq)
  44 {
  45     VirtIOSCSIReq *req;
  46     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
  47     const size_t zero_skip = offsetof(VirtIOSCSIReq, elem)
  48                              + sizeof(VirtQueueElement);
  49
  50     req = g_slice_alloc(sizeof(*req) + vs->cdb_size);
  51     req->vq = vq;
  52     req->dev = s;
  53     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, &address_space_memory);
  54     qemu_iovec_init(&req->resp_iov, 1);
  55     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  56     return req;
  57 }
  58
  59 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  60 {
  61     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)req->dev;
  62
  63     qemu_iovec_destroy(&req->resp_iov);
  64     qemu_sglist_destroy(&req->qsgl);
  65     g_slice_free1(sizeof(*req) + vs->cdb_size, req);
  66 }
  67
  68 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  69 {
  70     VirtIOSCSI *s = req->dev;
  71     VirtQueue *vq = req->vq;
  72     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  73
  74     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  75     if (req->vring) {
  76         assert(req->vq == NULL);
  77         virtio_scsi_vring_push_notify(req);
  78     } else {
  79         virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  80         virtio_notify(vdev, vq);
  81     }
  82
  83     if (req->sreq) {
  84         req->sreq->hba_private = NULL;
  85         scsi_req_unref(req->sreq);
  86     }
  87     virtio_scsi_free_req(req);
  88 }
  89
  90 static void virtio_scsi_bad_req(void)
  91 {
  92     error_report("wrong size for virtio-scsi headers");
  93     exit(1);
  94 }
  95
  96 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  97                               hwaddr *addr, int num, size_t skip)
  98 {
  99     QEMUSGList *qsgl = &req->qsgl;
 100     size_t copied = 0;
 101
 102     while (num) {
 103         if (skip >= iov->iov_len) {
 104             skip -= iov->iov_len;
 105         } else {
 106             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 107             copied += iov->iov_len - skip;
 108             skip = 0;
 109         }
 110         iov++;
 111         addr++;
 112         num--;
 113     }
 114
 115     assert(skip == 0);
 116     return copied;
 117 }
 118
 119 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 120                                  unsigned req_size, unsigned resp_size)
 121 {
 122     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 123     size_t in_size, out_size;
 124
 125     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 126                    &req->req, req_size) < req_size) {
 127         return -EINVAL;
 128     }
 129
 130     if (qemu_iovec_concat_iov(&req->resp_iov,
 131                               req->elem.in_sg, req->elem.in_num, 0,
 132                               resp_size) < resp_size) {
 133         return -EINVAL;
 134     }
 135
 136     req->resp_size = resp_size;
 137
 138     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 139      * As a workaround, always consider the first buffer as the virtio-scsi
 140      * request/response, making the payload start at the second element
 141      * of the iovec.
 142      *
 143      * The actual length of the response header, stored in req->resp_size,
 144      * does not change.
 145      *
 146      * TODO: always disable this workaround for virtio 1.0 devices.
 147      */
 148     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 149         if (req->elem.out_num) {
 150             req_size = req->elem.out_sg[0].iov_len;
 151         }
 152         if (req->elem.in_num) {
 153             resp_size = req->elem.in_sg[0].iov_len;
 154         }
 155     }
 156
 157     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 158                                &req->elem.out_addr[0], req->elem.out_num,
 159                                req_size);
 160     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 161                               &req->elem.in_addr[0], req->elem.in_num,
 162                               resp_size);
 163
 164     if (out_size && in_size) {
 165         return -ENOTSUP;
 166     }
 167
 168     if (out_size) {
 169         req->mode = SCSI_XFER_TO_DEV;
 170     } else if (in_size) {
 171         req->mode = SCSI_XFER_FROM_DEV;
 172     }
 173
 174     return 0;
 175 }
 176
 177 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 178 {
 179     VirtIOSCSIReq *req = virtio_scsi_init_req(s, vq);
 180     if (!virtqueue_pop(vq, &req->elem)) {
 181         virtio_scsi_free_req(req);
 182         return NULL;
 183     }
 184     return req;
 185 }
 186
 187 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 188 {
 189     VirtIOSCSIReq *req = sreq->hba_private;
 190     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 191     uint32_t n = virtio_queue_get_id(req->vq) - 2;
 192
 193     assert(n < vs->conf.num_queues);
 194     qemu_put_be32s(f, &n);
 195     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 196 }
 197
 198 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 199 {
 200     SCSIBus *bus = sreq->bus;
 201     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 202     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 203     VirtIOSCSIReq *req;
 204     uint32_t n;
 205
 206     qemu_get_be32s(f, &n);
 207     assert(n < vs->conf.num_queues);
 208     req = virtio_scsi_init_req(s, vs->cmd_vqs[n]);
 209     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 210     /* TODO: add a way for SCSIBusInfo's load_request to fail,
 211      * and fail migration instead of asserting here.
 212      * When we do, we might be able to re-enable NDEBUG below.
 213      */
 214 #ifdef NDEBUG
 215 #error building with NDEBUG is not supported
 216 #endif
 217     assert(req->elem.in_num <= ARRAY_SIZE(req->elem.in_sg));
 218     assert(req->elem.out_num <= ARRAY_SIZE(req->elem.out_sg));
 219
 220     virtqueue_map_sg(req->elem.in_sg, req->elem.in_addr,
 221                      req->elem.in_num, 1);
 222     virtqueue_map_sg(req->elem.out_sg, req->elem.out_addr,
 223                      req->elem.out_num, 0);
 224
 225     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 226                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 227         error_report("invalid SCSI request migration data");
 228         exit(1);
 229     }
 230
 231     scsi_req_ref(sreq);
 232     req->sreq = sreq;
 233     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 234         assert(req->sreq->cmd.mode == req->mode);
 235     }
 236     return req;
 237 }
 238
 239 typedef struct {
 240     Notifier        notifier;
 241     VirtIOSCSIReq  *tmf_req;
 242 } VirtIOSCSICancelNotifier;
 243
 244 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 245 {
 246     VirtIOSCSICancelNotifier *n = container_of(notifier,
 247                                                VirtIOSCSICancelNotifier,
 248                                                notifier);
 249
 250     if (--n->tmf_req->remaining == 0) {
 251         virtio_scsi_complete_req(n->tmf_req);
 252     }
 253     g_slice_free(VirtIOSCSICancelNotifier, n);
 254 }
 255
 256 /* Return 0 if the request is ready to be completed and return to guest;
 257  * -EINPROGRESS if the request is submitted and will be completed later, in the
 258  *  case of async cancellation. */
 259 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 260 {
 261     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 262     SCSIRequest *r, *next;
 263     BusChild *kid;
 264     int target;
 265     int ret = 0;
 266
 267     if (s->dataplane_started) {
 268         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 269     }
 270     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 271     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 272
 273     virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
 274     switch (req->req.tmf.subtype) {
 275     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 276     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 277         if (!d) {
 278             goto fail;
 279         }
 280         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 281             goto incorrect_lun;
 282         }
 283         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 284             VirtIOSCSIReq *cmd_req = r->hba_private;
 285             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 286                 break;
 287             }
 288         }
 289         if (r) {
 290             /*
 291              * Assert that the request has not been completed yet, we
 292              * check for it in the loop above.
 293              */
 294             assert(r->hba_private);
 295             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 296                 /* "If the specified command is present in the task set, then
 297                  * return a service response set to FUNCTION SUCCEEDED".
 298                  */
 299                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 300             } else {
 301                 VirtIOSCSICancelNotifier *notifier;
 302
 303                 req->remaining = 1;
 304                 notifier = g_slice_new(VirtIOSCSICancelNotifier);
 305                 notifier->tmf_req = req;
 306                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 307                 scsi_req_cancel_async(r, &notifier->notifier);
 308                 ret = -EINPROGRESS;
 309             }
 310         }
 311         break;
 312
 313     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 314         if (!d) {
 315             goto fail;
 316         }
 317         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 318             goto incorrect_lun;
 319         }
 320         s->resetting++;
 321         qdev_reset_all(&d->qdev);
 322         s->resetting--;
 323         break;
 324
 325     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 326     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 327     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 328         if (!d) {
 329             goto fail;
 330         }
 331         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 332             goto incorrect_lun;
 333         }
 334
 335         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 336          * This way, if the bus starts calling back to the notifiers
 337          * even before we finish the loop, virtio_scsi_cancel_notify
 338          * will not complete the TMF too early.
 339          */
 340         req->remaining = 1;
 341         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 342             if (r->hba_private) {
 343                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 344                     /* "If there is any command present in the task set, then
 345                      * return a service response set to FUNCTION SUCCEEDED".
 346                      */
 347                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 348                     break;
 349                 } else {
 350                     VirtIOSCSICancelNotifier *notifier;
 351
 352                     req->remaining++;
 353                     notifier = g_slice_new(VirtIOSCSICancelNotifier);
 354                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 355                     notifier->tmf_req = req;
 356                     scsi_req_cancel_async(r, &notifier->notifier);
 357                 }
 358             }
 359         }
 360         if (--req->remaining > 0) {
 361             ret = -EINPROGRESS;
 362         }
 363         break;
 364
 365     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 366         target = req->req.tmf.lun[1];
 367         s->resetting++;
 368         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 369              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
 370              if (d->channel == 0 && d->id == target) {
 371                 qdev_reset_all(&d->qdev);
 372              }
 373         }
 374         s->resetting--;
 375         break;
 376
 377     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 378     default:
 379         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 380         break;
 381     }
 382
 383     return ret;
 384
 385 incorrect_lun:
 386     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 387     return ret;
 388
 389 fail:
 390     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 391     return ret;
 392 }
 393
 394 void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 395 {
 396     VirtIODevice *vdev = (VirtIODevice *)s;
 397     uint32_t type;
 398     int r = 0;
 399
 400     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 401                 &type, sizeof(type)) < sizeof(type)) {
 402         virtio_scsi_bad_req();
 403         return;
 404     }
 405
 406     virtio_tswap32s(vdev, &type);
 407     if (type == VIRTIO_SCSI_T_TMF) {
 408         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 409                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 410             virtio_scsi_bad_req();
 411         } else {
 412             r = virtio_scsi_do_tmf(s, req);
 413         }
 414
 415     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 416                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 417         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 418                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 419             virtio_scsi_bad_req();
 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 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 433 {
 434     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 435     VirtIOSCSIReq *req;
 436
 437     if (s->ctx && !s->dataplane_disabled) {
 438         virtio_scsi_dataplane_start(s);
 439         return;
 440     }
 441     while ((req = virtio_scsi_pop_req(s, vq))) {
 442         virtio_scsi_handle_ctrl_req(s, req);
 443     }
 444 }
 445
 446 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 447 {
 448     /* Sense data is not in req->resp and is copied separately
 449      * in virtio_scsi_command_complete.
 450      */
 451     req->resp_size = sizeof(VirtIOSCSICmdResp);
 452     virtio_scsi_complete_req(req);
 453 }
 454
 455 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 456                                          size_t resid)
 457 {
 458     VirtIOSCSIReq *req = r->hba_private;
 459     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 460     uint32_t sense_len;
 461     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 462
 463     if (r->io_canceled) {
 464         return;
 465     }
 466
 467     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 468     req->resp.cmd.status = status;
 469     if (req->resp.cmd.status == GOOD) {
 470         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 471     } else {
 472         req->resp.cmd.resid = 0;
 473         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 474         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 475         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 476                             sense, sense_len);
 477         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 478     }
 479     virtio_scsi_complete_cmd_req(req);
 480 }
 481
 482 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 483                                  uint8_t *buf, void *hba_private)
 484 {
 485     VirtIOSCSIReq *req = hba_private;
 486
 487     if (cmd->len == 0) {
 488         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 489         memcpy(cmd->buf, buf, cmd->len);
 490     }
 491
 492     /* Extract the direction and mode directly from the request, for
 493      * host device passthrough.
 494      */
 495     cmd->xfer = req->qsgl.size;
 496     cmd->mode = req->mode;
 497     return 0;
 498 }
 499
 500 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 501 {
 502     VirtIOSCSIReq *req = r->hba_private;
 503
 504     return &req->qsgl;
 505 }
 506
 507 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 508 {
 509     VirtIOSCSIReq *req = r->hba_private;
 510
 511     if (!req) {
 512         return;
 513     }
 514     if (req->dev->resetting) {
 515         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 516     } else {
 517         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 518     }
 519     virtio_scsi_complete_cmd_req(req);
 520 }
 521
 522 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 523 {
 524     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 525     virtio_scsi_complete_cmd_req(req);
 526 }
 527
 528 bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 529 {
 530     VirtIOSCSICommon *vs = &s->parent_obj;
 531     SCSIDevice *d;
 532     int rc;
 533
 534     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 535                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 536     if (rc < 0) {
 537         if (rc == -ENOTSUP) {
 538             virtio_scsi_fail_cmd_req(req);
 539         } else {
 540             virtio_scsi_bad_req();
 541         }
 542         return false;
 543     }
 544
 545     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 546     if (!d) {
 547         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 548         virtio_scsi_complete_cmd_req(req);
 549         return false;
 550     }
 551     if (s->dataplane_started) {
 552         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 553     }
 554     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 555                              virtio_scsi_get_lun(req->req.cmd.lun),
 556                              req->req.cmd.cdb, req);
 557
 558     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 559         && (req->sreq->cmd.mode != req->mode ||
 560             req->sreq->cmd.xfer > req->qsgl.size)) {
 561         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 562         virtio_scsi_complete_cmd_req(req);
 563         return false;
 564     }
 565     scsi_req_ref(req->sreq);
 566     blk_io_plug(d->conf.blk);
 567     return true;
 568 }
 569
 570 void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 571 {
 572     SCSIRequest *sreq = req->sreq;
 573     if (scsi_req_enqueue(sreq)) {
 574         scsi_req_continue(sreq);
 575     }
 576     blk_io_unplug(sreq->dev->conf.blk);
 577     scsi_req_unref(sreq);
 578 }
 579
 580 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 581 {
 582     /* use non-QOM casts in the data path */
 583     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 584     VirtIOSCSIReq *req, *next;
 585     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 586
 587     if (s->ctx && !s->dataplane_disabled) {
 588         virtio_scsi_dataplane_start(s);
 589         return;
 590     }
 591     while ((req = virtio_scsi_pop_req(s, vq))) {
 592         if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
 593             QTAILQ_INSERT_TAIL(&reqs, req, next);
 594         }
 595     }
 596
 597     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 598         virtio_scsi_handle_cmd_req_submit(s, req);
 599     }
 600 }
 601
 602 static void virtio_scsi_get_config(VirtIODevice *vdev,
 603                                    uint8_t *config)
 604 {
 605     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 606     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 607
 608     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 609     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 610     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 611     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 612     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 613     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 614     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 615     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 616     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 617     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 618 }
 619
 620 static void virtio_scsi_set_config(VirtIODevice *vdev,
 621                                    const uint8_t *config)
 622 {
 623     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 624     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 625
 626     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 627         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 628         error_report("bad data written to virtio-scsi configuration space");
 629         exit(1);
 630     }
 631
 632     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 633     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 634 }
 635
 636 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 637                                          uint64_t requested_features,
 638                                          Error **errp)
 639 {
 640     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 641
 642     /* Firstly sync all virtio-scsi possible supported features */
 643     requested_features |= s->host_features;
 644     return requested_features;
 645 }
 646
 647 static void virtio_scsi_reset(VirtIODevice *vdev)
 648 {
 649     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 650     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 651
 652     if (s->ctx) {
 653         virtio_scsi_dataplane_stop(s);
 654     }
 655     s->resetting++;
 656     qbus_reset_all(&s->bus.qbus);
 657     s->resetting--;
 658
 659     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 660     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 661     s->events_dropped = false;
 662 }
 663
 664 /* The device does not have anything to save beyond the virtio data.
 665  * Request data is saved with callbacks from SCSI devices.
 666  */
 667 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 668 {
 669     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 670     virtio_save(vdev, f);
 671 }
 672
 673 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 674 {
 675     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 676     int ret;
 677
 678     ret = virtio_load(vdev, f, version_id);
 679     if (ret) {
 680         return ret;
 681     }
 682     return 0;
 683 }
 684
 685 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 686                             uint32_t event, uint32_t reason)
 687 {
 688     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 689     VirtIOSCSIReq *req;
 690     VirtIOSCSIEvent *evt;
 691     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 692
 693     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 694         return;
 695     }
 696
 697     if (s->dataplane_started) {
 698         assert(s->ctx);
 699         aio_context_acquire(s->ctx);
 700     }
 701
 702     if (s->dataplane_started) {
 703         req = virtio_scsi_pop_req_vring(s, s->event_vring);
 704     } else {
 705         req = virtio_scsi_pop_req(s, vs->event_vq);
 706     }
 707     if (!req) {
 708         s->events_dropped = true;
 709         goto out;
 710     }
 711
 712     if (s->events_dropped) {
 713         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 714         s->events_dropped = false;
 715     }
 716
 717     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 718         virtio_scsi_bad_req();
 719     }
 720
 721     evt = &req->resp.event;
 722     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 723     evt->event = virtio_tswap32(vdev, event);
 724     evt->reason = virtio_tswap32(vdev, reason);
 725     if (!dev) {
 726         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 727     } else {
 728         evt->lun[0] = 1;
 729         evt->lun[1] = dev->id;
 730
 731         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 732         if (dev->lun >= 256) {
 733             evt->lun[2] = (dev->lun >> 8) | 0x40;
 734         }
 735         evt->lun[3] = dev->lun & 0xFF;
 736     }
 737     virtio_scsi_complete_req(req);
 738 out:
 739     if (s->dataplane_started) {
 740         aio_context_release(s->ctx);
 741     }
 742 }
 743
 744 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 745 {
 746     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 747
 748     if (s->ctx && !s->dataplane_disabled) {
 749         virtio_scsi_dataplane_start(s);
 750         return;
 751     }
 752     if (s->events_dropped) {
 753         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 754     }
 755 }
 756
 757 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 758 {
 759     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 760     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 761
 762     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 763         dev->type != TYPE_ROM) {
 764         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 765                                sense.asc | (sense.ascq << 8));
 766     }
 767 }
 768
 769 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 770                                 Error **errp)
 771 {
 772     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 773     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 774     SCSIDevice *sd = SCSI_DEVICE(dev);
 775
 776     if (s->ctx && !s->dataplane_disabled) {
 777         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 778             return;
 779         }
 780         blk_op_block_all(sd->conf.blk, s->blocker);
 781         aio_context_acquire(s->ctx);
 782         blk_set_aio_context(sd->conf.blk, s->ctx);
 783         aio_context_release(s->ctx);
 784     }
 785
 786     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 787         virtio_scsi_push_event(s, sd,
 788                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 789                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 790     }
 791 }
 792
 793 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 794                                   Error **errp)
 795 {
 796     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 797     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 798     SCSIDevice *sd = SCSI_DEVICE(dev);
 799
 800     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 801         virtio_scsi_push_event(s, sd,
 802                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 803                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 804     }
 805
 806     if (s->ctx) {
 807         blk_op_unblock_all(sd->conf.blk, s->blocker);
 808     }
 809     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 810 }
 811
 812 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 813     .tcq = true,
 814     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 815     .max_target = VIRTIO_SCSI_MAX_TARGET,
 816     .max_lun = VIRTIO_SCSI_MAX_LUN,
 817
 818     .complete = virtio_scsi_command_complete,
 819     .cancel = virtio_scsi_request_cancelled,
 820     .change = virtio_scsi_change,
 821     .parse_cdb = virtio_scsi_parse_cdb,
 822     .get_sg_list = virtio_scsi_get_sg_list,
 823     .save_request = virtio_scsi_save_request,
 824     .load_request = virtio_scsi_load_request,
 825 };
 826
 827 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 828                                 HandleOutput ctrl, HandleOutput evt,
 829                                 HandleOutput cmd)
 830 {
 831     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 832     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 833     int i;
 834
 835     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 836                 sizeof(VirtIOSCSIConfig));
 837
 838     if (s->conf.num_queues == 0 ||
 839             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 840         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 841                          "must be a positive integer less than %d.",
 842                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 843         virtio_cleanup(vdev);
 844         return;
 845     }
 846     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 847     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 848     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 849
 850     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 851                                   ctrl);
 852     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 853                                    evt);
 854     for (i = 0; i < s->conf.num_queues; i++) {
 855         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 856                                          cmd);
 857     }
 858
 859     if (s->conf.iothread) {
 860         virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
 861     }
 862 }
 863
 864 /* Disable dataplane thread during live migration since it does not
 865  * update the dirty memory bitmap yet.
 866  */
 867 static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
 868 {
 869     VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
 870                                  migration_state_notifier);
 871     MigrationState *mig = data;
 872
 873     if (migration_in_setup(mig)) {
 874         if (!s->dataplane_started) {
 875             return;
 876         }
 877         virtio_scsi_dataplane_stop(s);
 878         s->dataplane_disabled = true;
 879     } else if (migration_has_finished(mig) ||
 880                migration_has_failed(mig)) {
 881         if (s->dataplane_started) {
 882             return;
 883         }
 884         blk_drain_all(); /* complete in-flight non-dataplane requests */
 885         s->dataplane_disabled = false;
 886     }
 887 }
 888
 889 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 890 {
 891     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 892     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 893     static int virtio_scsi_id;
 894     Error *err = NULL;
 895
 896     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 897                                virtio_scsi_handle_event,
 898                                virtio_scsi_handle_cmd);
 899     if (err != NULL) {
 900         error_propagate(errp, err);
 901         return;
 902     }
 903
 904     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 905                  &virtio_scsi_scsi_info, vdev->bus_name);
 906     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 907     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 908
 909     if (!dev->hotplugged) {
 910         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 911         if (err != NULL) {
 912             error_propagate(errp, err);
 913             return;
 914         }
 915     }
 916
 917     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 918                     virtio_scsi_save, virtio_scsi_load, s);
 919     s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
 920     add_migration_state_change_notifier(&s->migration_state_notifier);
 921
 922     error_setg(&s->blocker, "block device is in use by data plane");
 923 }
 924
 925 static void virtio_scsi_instance_init(Object *obj)
 926 {
 927     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 928
 929     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 930                              (Object **)&vs->conf.iothread,
 931                              qdev_prop_allow_set_link_before_realize,
 932                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 933 }
 934
 935 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 936 {
 937     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 938     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 939
 940     g_free(vs->cmd_vqs);
 941     virtio_cleanup(vdev);
 942 }
 943
 944 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 945 {
 946     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 947
 948     error_free(s->blocker);
 949
 950     unregister_savevm(dev, "virtio-scsi", s);
 951     remove_migration_state_change_notifier(&s->migration_state_notifier);
 952
 953     virtio_scsi_common_unrealize(dev, errp);
 954 }
 955
 956 static Property virtio_scsi_properties[] = {
 957     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 958     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 959                                                   0xFFFF),
 960     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 961                                                   128),
 962     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 963                                            VIRTIO_SCSI_F_HOTPLUG, true),
 964     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 965                                                 VIRTIO_SCSI_F_CHANGE, true),
 966     DEFINE_PROP_END_OF_LIST(),
 967 };
 968
 969 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 970 {
 971     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 972     DeviceClass *dc = DEVICE_CLASS(klass);
 973
 974     vdc->get_config = virtio_scsi_get_config;
 975     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 976 }
 977
 978 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 979 {
 980     DeviceClass *dc = DEVICE_CLASS(klass);
 981     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 982     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 983
 984     dc->props = virtio_scsi_properties;
 985     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 986     vdc->realize = virtio_scsi_device_realize;
 987     vdc->unrealize = virtio_scsi_device_unrealize;
 988     vdc->set_config = virtio_scsi_set_config;
 989     vdc->get_features = virtio_scsi_get_features;
 990     vdc->reset = virtio_scsi_reset;
 991     hc->plug = virtio_scsi_hotplug;
 992     hc->unplug = virtio_scsi_hotunplug;
 993 }
 994
 995 static const TypeInfo virtio_scsi_common_info = {
 996     .name = TYPE_VIRTIO_SCSI_COMMON,
 997     .parent = TYPE_VIRTIO_DEVICE,
 998     .instance_size = sizeof(VirtIOSCSICommon),
 999     .abstract = true,
1000     .class_init = virtio_scsi_common_class_init,
1001 };
1002
1003 static const TypeInfo virtio_scsi_info = {
1004     .name = TYPE_VIRTIO_SCSI,
1005     .parent = TYPE_VIRTIO_SCSI_COMMON,
1006     .instance_size = sizeof(VirtIOSCSI),
1007     .instance_init = virtio_scsi_instance_init,
1008     .class_init = virtio_scsi_class_init,
1009     .interfaces = (InterfaceInfo[]) {
1010         { TYPE_HOTPLUG_HANDLER },
1011         { }
1012     }
1013 };
1014
1015 static void virtio_register_types(void)
1016 {
1017     type_register_static(&virtio_scsi_common_info);
1018     type_register_static(&virtio_scsi_info);
1019 }
1020
1021 type_init(virtio_register_types)