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 "standard-headers/linux/virtio_ids.h"
  18 #include "hw/virtio/virtio-scsi.h"
  19 #include "qemu/error-report.h"
  20 #include "qemu/iov.h"
  21 #include "sysemu/block-backend.h"
  22 #include <hw/scsi/scsi.h>
  23 #include <block/scsi.h>
  24 #include <hw/virtio/virtio-bus.h>
  25 #include "hw/virtio/virtio-access.h"
  26 #include "migration/migration.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 VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq)
  45 {
  46     VirtIOSCSIReq *req;
  47     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
  48     const size_t zero_skip = offsetof(VirtIOSCSIReq, elem)
  49                              + sizeof(VirtQueueElement);
  50
  51     req = g_malloc(sizeof(*req) + vs->cdb_size);
  52     req->vq = vq;
  53     req->dev = s;
  54     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, &address_space_memory);
  55     qemu_iovec_init(&req->resp_iov, 1);
  56     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  57     return req;
  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     if (req->vring) {
  75         assert(req->vq == NULL);
  76         virtio_scsi_vring_push_notify(req);
  77     } else {
  78         virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  79         virtio_notify(vdev, vq);
  80     }
  81
  82     if (req->sreq) {
  83         req->sreq->hba_private = NULL;
  84         scsi_req_unref(req->sreq);
  85     }
  86     virtio_scsi_free_req(req);
  87 }
  88
  89 static void virtio_scsi_bad_req(void)
  90 {
  91     error_report("wrong size for virtio-scsi headers");
  92     exit(1);
  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     VirtIOSCSIReq *req = virtio_scsi_init_req(s, vq);
 179     if (!virtqueue_pop(vq, &req->elem)) {
 180         virtio_scsi_free_req(req);
 181         return NULL;
 182     }
 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_queue_get_id(req->vq) - 2;
 191
 192     assert(n < vs->conf.num_queues);
 193     qemu_put_be32s(f, &n);
 194     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(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     VirtIOSCSIReq *req;
 203     uint32_t n;
 204
 205     qemu_get_be32s(f, &n);
 206     assert(n < vs->conf.num_queues);
 207     req = virtio_scsi_init_req(s, vs->cmd_vqs[n]);
 208     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 209
 210     virtqueue_map(&req->elem);
 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 /* Return 0 if the request is ready to be completed and return to guest;
 244  * -EINPROGRESS if the request is submitted and will be completed later, in the
 245  *  case of async cancellation. */
 246 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 247 {
 248     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 249     SCSIRequest *r, *next;
 250     BusChild *kid;
 251     int target;
 252     int ret = 0;
 253
 254     if (s->dataplane_started && d) {
 255         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 256     }
 257     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 258     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 259
 260     virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
 261     switch (req->req.tmf.subtype) {
 262     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 263     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 264         if (!d) {
 265             goto fail;
 266         }
 267         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 268             goto incorrect_lun;
 269         }
 270         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 271             VirtIOSCSIReq *cmd_req = r->hba_private;
 272             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 273                 break;
 274             }
 275         }
 276         if (r) {
 277             /*
 278              * Assert that the request has not been completed yet, we
 279              * check for it in the loop above.
 280              */
 281             assert(r->hba_private);
 282             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 283                 /* "If the specified command is present in the task set, then
 284                  * return a service response set to FUNCTION SUCCEEDED".
 285                  */
 286                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 287             } else {
 288                 VirtIOSCSICancelNotifier *notifier;
 289
 290                 req->remaining = 1;
 291                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 292                 notifier->tmf_req = req;
 293                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 294                 scsi_req_cancel_async(r, &notifier->notifier);
 295                 ret = -EINPROGRESS;
 296             }
 297         }
 298         break;
 299
 300     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 301         if (!d) {
 302             goto fail;
 303         }
 304         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 305             goto incorrect_lun;
 306         }
 307         s->resetting++;
 308         qdev_reset_all(&d->qdev);
 309         s->resetting--;
 310         break;
 311
 312     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 313     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 314     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 315         if (!d) {
 316             goto fail;
 317         }
 318         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 319             goto incorrect_lun;
 320         }
 321
 322         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 323          * This way, if the bus starts calling back to the notifiers
 324          * even before we finish the loop, virtio_scsi_cancel_notify
 325          * will not complete the TMF too early.
 326          */
 327         req->remaining = 1;
 328         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 329             if (r->hba_private) {
 330                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 331                     /* "If there is any command present in the task set, then
 332                      * return a service response set to FUNCTION SUCCEEDED".
 333                      */
 334                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 335                     break;
 336                 } else {
 337                     VirtIOSCSICancelNotifier *notifier;
 338
 339                     req->remaining++;
 340                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 341                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 342                     notifier->tmf_req = req;
 343                     scsi_req_cancel_async(r, &notifier->notifier);
 344                 }
 345             }
 346         }
 347         if (--req->remaining > 0) {
 348             ret = -EINPROGRESS;
 349         }
 350         break;
 351
 352     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 353         target = req->req.tmf.lun[1];
 354         s->resetting++;
 355         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 356              d = SCSI_DEVICE(kid->child);
 357              if (d->channel == 0 && d->id == target) {
 358                 qdev_reset_all(&d->qdev);
 359              }
 360         }
 361         s->resetting--;
 362         break;
 363
 364     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 365     default:
 366         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 367         break;
 368     }
 369
 370     return ret;
 371
 372 incorrect_lun:
 373     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 374     return ret;
 375
 376 fail:
 377     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 378     return ret;
 379 }
 380
 381 void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 382 {
 383     VirtIODevice *vdev = (VirtIODevice *)s;
 384     uint32_t type;
 385     int r = 0;
 386
 387     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 388                 &type, sizeof(type)) < sizeof(type)) {
 389         virtio_scsi_bad_req();
 390         return;
 391     }
 392
 393     virtio_tswap32s(vdev, &type);
 394     if (type == VIRTIO_SCSI_T_TMF) {
 395         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 396                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 397             virtio_scsi_bad_req();
 398         } else {
 399             r = virtio_scsi_do_tmf(s, req);
 400         }
 401
 402     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 403                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 404         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 405                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 406             virtio_scsi_bad_req();
 407         } else {
 408             req->resp.an.event_actual = 0;
 409             req->resp.an.response = VIRTIO_SCSI_S_OK;
 410         }
 411     }
 412     if (r == 0) {
 413         virtio_scsi_complete_req(req);
 414     } else {
 415         assert(r == -EINPROGRESS);
 416     }
 417 }
 418
 419 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 420 {
 421     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 422     VirtIOSCSIReq *req;
 423
 424     if (s->ctx && !s->dataplane_disabled) {
 425         virtio_scsi_dataplane_start(s);
 426         return;
 427     }
 428     while ((req = virtio_scsi_pop_req(s, vq))) {
 429         virtio_scsi_handle_ctrl_req(s, req);
 430     }
 431 }
 432
 433 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 434 {
 435     /* Sense data is not in req->resp and is copied separately
 436      * in virtio_scsi_command_complete.
 437      */
 438     req->resp_size = sizeof(VirtIOSCSICmdResp);
 439     virtio_scsi_complete_req(req);
 440 }
 441
 442 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 443                                          size_t resid)
 444 {
 445     VirtIOSCSIReq *req = r->hba_private;
 446     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 447     uint32_t sense_len;
 448     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 449
 450     if (r->io_canceled) {
 451         return;
 452     }
 453
 454     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 455     req->resp.cmd.status = status;
 456     if (req->resp.cmd.status == GOOD) {
 457         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 458     } else {
 459         req->resp.cmd.resid = 0;
 460         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 461         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 462         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 463                             sense, sense_len);
 464         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 465     }
 466     virtio_scsi_complete_cmd_req(req);
 467 }
 468
 469 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 470                                  uint8_t *buf, void *hba_private)
 471 {
 472     VirtIOSCSIReq *req = hba_private;
 473
 474     if (cmd->len == 0) {
 475         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 476         memcpy(cmd->buf, buf, cmd->len);
 477     }
 478
 479     /* Extract the direction and mode directly from the request, for
 480      * host device passthrough.
 481      */
 482     cmd->xfer = req->qsgl.size;
 483     cmd->mode = req->mode;
 484     return 0;
 485 }
 486
 487 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 488 {
 489     VirtIOSCSIReq *req = r->hba_private;
 490
 491     return &req->qsgl;
 492 }
 493
 494 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 495 {
 496     VirtIOSCSIReq *req = r->hba_private;
 497
 498     if (!req) {
 499         return;
 500     }
 501     if (req->dev->resetting) {
 502         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 503     } else {
 504         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 505     }
 506     virtio_scsi_complete_cmd_req(req);
 507 }
 508
 509 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 510 {
 511     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 512     virtio_scsi_complete_cmd_req(req);
 513 }
 514
 515 bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 516 {
 517     VirtIOSCSICommon *vs = &s->parent_obj;
 518     SCSIDevice *d;
 519     int rc;
 520
 521     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 522                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 523     if (rc < 0) {
 524         if (rc == -ENOTSUP) {
 525             virtio_scsi_fail_cmd_req(req);
 526         } else {
 527             virtio_scsi_bad_req();
 528         }
 529         return false;
 530     }
 531
 532     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 533     if (!d) {
 534         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 535         virtio_scsi_complete_cmd_req(req);
 536         return false;
 537     }
 538     if (s->dataplane_started) {
 539         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 540     }
 541     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 542                              virtio_scsi_get_lun(req->req.cmd.lun),
 543                              req->req.cmd.cdb, req);
 544
 545     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 546         && (req->sreq->cmd.mode != req->mode ||
 547             req->sreq->cmd.xfer > req->qsgl.size)) {
 548         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 549         virtio_scsi_complete_cmd_req(req);
 550         return false;
 551     }
 552     scsi_req_ref(req->sreq);
 553     blk_io_plug(d->conf.blk);
 554     return true;
 555 }
 556
 557 void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 558 {
 559     SCSIRequest *sreq = req->sreq;
 560     if (scsi_req_enqueue(sreq)) {
 561         scsi_req_continue(sreq);
 562     }
 563     blk_io_unplug(sreq->dev->conf.blk);
 564     scsi_req_unref(sreq);
 565 }
 566
 567 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 568 {
 569     /* use non-QOM casts in the data path */
 570     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 571     VirtIOSCSIReq *req, *next;
 572     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 573
 574     if (s->ctx && !s->dataplane_disabled) {
 575         virtio_scsi_dataplane_start(s);
 576         return;
 577     }
 578     while ((req = virtio_scsi_pop_req(s, vq))) {
 579         if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
 580             QTAILQ_INSERT_TAIL(&reqs, req, next);
 581         }
 582     }
 583
 584     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 585         virtio_scsi_handle_cmd_req_submit(s, req);
 586     }
 587 }
 588
 589 static void virtio_scsi_get_config(VirtIODevice *vdev,
 590                                    uint8_t *config)
 591 {
 592     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 593     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 594
 595     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 596     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 597     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 598     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 599     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 600     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 601     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 602     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 603     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 604     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 605 }
 606
 607 static void virtio_scsi_set_config(VirtIODevice *vdev,
 608                                    const uint8_t *config)
 609 {
 610     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 611     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 612
 613     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 614         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 615         error_report("bad data written to virtio-scsi configuration space");
 616         exit(1);
 617     }
 618
 619     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 620     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 621 }
 622
 623 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 624                                          uint64_t requested_features,
 625                                          Error **errp)
 626 {
 627     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 628
 629     /* Firstly sync all virtio-scsi possible supported features */
 630     requested_features |= s->host_features;
 631     return requested_features;
 632 }
 633
 634 static void virtio_scsi_reset(VirtIODevice *vdev)
 635 {
 636     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 637     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 638
 639     if (s->ctx) {
 640         virtio_scsi_dataplane_stop(s);
 641     }
 642     s->resetting++;
 643     qbus_reset_all(&s->bus.qbus);
 644     s->resetting--;
 645
 646     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 647     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 648     s->events_dropped = false;
 649 }
 650
 651 /* The device does not have anything to save beyond the virtio data.
 652  * Request data is saved with callbacks from SCSI devices.
 653  */
 654 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 655 {
 656     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 657     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 658
 659     if (s->dataplane_started) {
 660         virtio_scsi_dataplane_stop(s);
 661     }
 662     virtio_save(vdev, f);
 663 }
 664
 665 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 666 {
 667     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 668     int ret;
 669
 670     ret = virtio_load(vdev, f, version_id);
 671     if (ret) {
 672         return ret;
 673     }
 674     return 0;
 675 }
 676
 677 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 678                             uint32_t event, uint32_t reason)
 679 {
 680     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 681     VirtIOSCSIReq *req;
 682     VirtIOSCSIEvent *evt;
 683     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 684
 685     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 686         return;
 687     }
 688
 689     if (s->dataplane_started) {
 690         assert(s->ctx);
 691         aio_context_acquire(s->ctx);
 692     }
 693
 694     if (s->dataplane_started) {
 695         req = virtio_scsi_pop_req_vring(s, s->event_vring);
 696     } else {
 697         req = virtio_scsi_pop_req(s, vs->event_vq);
 698     }
 699     if (!req) {
 700         s->events_dropped = true;
 701         goto out;
 702     }
 703
 704     if (s->events_dropped) {
 705         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 706         s->events_dropped = false;
 707     }
 708
 709     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 710         virtio_scsi_bad_req();
 711     }
 712
 713     evt = &req->resp.event;
 714     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 715     evt->event = virtio_tswap32(vdev, event);
 716     evt->reason = virtio_tswap32(vdev, reason);
 717     if (!dev) {
 718         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 719     } else {
 720         evt->lun[0] = 1;
 721         evt->lun[1] = dev->id;
 722
 723         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 724         if (dev->lun >= 256) {
 725             evt->lun[2] = (dev->lun >> 8) | 0x40;
 726         }
 727         evt->lun[3] = dev->lun & 0xFF;
 728     }
 729     virtio_scsi_complete_req(req);
 730 out:
 731     if (s->dataplane_started) {
 732         aio_context_release(s->ctx);
 733     }
 734 }
 735
 736 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 737 {
 738     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 739
 740     if (s->ctx && !s->dataplane_disabled) {
 741         virtio_scsi_dataplane_start(s);
 742         return;
 743     }
 744     if (s->events_dropped) {
 745         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 746     }
 747 }
 748
 749 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 750 {
 751     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 752     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 753
 754     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 755         dev->type != TYPE_ROM) {
 756         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 757                                sense.asc | (sense.ascq << 8));
 758     }
 759 }
 760
 761 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 762                                 Error **errp)
 763 {
 764     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 765     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 766     SCSIDevice *sd = SCSI_DEVICE(dev);
 767
 768     if (s->ctx && !s->dataplane_disabled) {
 769         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 770             return;
 771         }
 772         blk_op_block_all(sd->conf.blk, s->blocker);
 773         aio_context_acquire(s->ctx);
 774         blk_set_aio_context(sd->conf.blk, s->ctx);
 775         aio_context_release(s->ctx);
 776     }
 777
 778     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 779         virtio_scsi_push_event(s, sd,
 780                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 781                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 782     }
 783 }
 784
 785 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 786                                   Error **errp)
 787 {
 788     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 789     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 790     SCSIDevice *sd = SCSI_DEVICE(dev);
 791
 792     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 793         virtio_scsi_push_event(s, sd,
 794                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 795                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 796     }
 797
 798     if (s->ctx) {
 799         blk_op_unblock_all(sd->conf.blk, s->blocker);
 800     }
 801     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 802 }
 803
 804 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 805     .tcq = true,
 806     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 807     .max_target = VIRTIO_SCSI_MAX_TARGET,
 808     .max_lun = VIRTIO_SCSI_MAX_LUN,
 809
 810     .complete = virtio_scsi_command_complete,
 811     .cancel = virtio_scsi_request_cancelled,
 812     .change = virtio_scsi_change,
 813     .parse_cdb = virtio_scsi_parse_cdb,
 814     .get_sg_list = virtio_scsi_get_sg_list,
 815     .save_request = virtio_scsi_save_request,
 816     .load_request = virtio_scsi_load_request,
 817 };
 818
 819 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 820                                 HandleOutput ctrl, HandleOutput evt,
 821                                 HandleOutput cmd)
 822 {
 823     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 824     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 825     int i;
 826
 827     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 828                 sizeof(VirtIOSCSIConfig));
 829
 830     if (s->conf.num_queues == 0 ||
 831             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 832         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 833                          "must be a positive integer less than %d.",
 834                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 835         virtio_cleanup(vdev);
 836         return;
 837     }
 838     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 839     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 840     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 841
 842     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 843                                   ctrl);
 844     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 845                                    evt);
 846     for (i = 0; i < s->conf.num_queues; i++) {
 847         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 848                                          cmd);
 849     }
 850
 851     if (s->conf.iothread) {
 852         virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
 853     }
 854 }
 855
 856 /* Disable dataplane thread during live migration since it does not
 857  * update the dirty memory bitmap yet.
 858  */
 859 static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
 860 {
 861     VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
 862                                  migration_state_notifier);
 863     MigrationState *mig = data;
 864
 865     if (migration_in_setup(mig)) {
 866         if (!s->dataplane_started) {
 867             return;
 868         }
 869         virtio_scsi_dataplane_stop(s);
 870         s->dataplane_disabled = true;
 871     } else if (migration_has_finished(mig) ||
 872                migration_has_failed(mig)) {
 873         if (s->dataplane_started) {
 874             return;
 875         }
 876         blk_drain_all(); /* complete in-flight non-dataplane requests */
 877         s->dataplane_disabled = false;
 878     }
 879 }
 880
 881 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 882 {
 883     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 884     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 885     static int virtio_scsi_id;
 886     Error *err = NULL;
 887
 888     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 889                                virtio_scsi_handle_event,
 890                                virtio_scsi_handle_cmd);
 891     if (err != NULL) {
 892         error_propagate(errp, err);
 893         return;
 894     }
 895
 896     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 897                  &virtio_scsi_scsi_info, vdev->bus_name);
 898     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 899     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 900
 901     if (!dev->hotplugged) {
 902         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 903         if (err != NULL) {
 904             error_propagate(errp, err);
 905             return;
 906         }
 907     }
 908
 909     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 910                     virtio_scsi_save, virtio_scsi_load, s);
 911     s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
 912     add_migration_state_change_notifier(&s->migration_state_notifier);
 913
 914     error_setg(&s->blocker, "block device is in use by data plane");
 915 }
 916
 917 static void virtio_scsi_instance_init(Object *obj)
 918 {
 919     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 920
 921     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 922                              (Object **)&vs->conf.iothread,
 923                              qdev_prop_allow_set_link_before_realize,
 924                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 925 }
 926
 927 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 928 {
 929     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 930     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 931
 932     g_free(vs->cmd_vqs);
 933     virtio_cleanup(vdev);
 934 }
 935
 936 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 937 {
 938     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 939
 940     error_free(s->blocker);
 941
 942     unregister_savevm(dev, "virtio-scsi", s);
 943     remove_migration_state_change_notifier(&s->migration_state_notifier);
 944
 945     virtio_scsi_common_unrealize(dev, errp);
 946 }
 947
 948 static Property virtio_scsi_properties[] = {
 949     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 950     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 951                                                   0xFFFF),
 952     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 953                                                   128),
 954     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 955                                            VIRTIO_SCSI_F_HOTPLUG, true),
 956     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 957                                                 VIRTIO_SCSI_F_CHANGE, true),
 958     DEFINE_PROP_END_OF_LIST(),
 959 };
 960
 961 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 962 {
 963     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 964     DeviceClass *dc = DEVICE_CLASS(klass);
 965
 966     vdc->get_config = virtio_scsi_get_config;
 967     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 968 }
 969
 970 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 971 {
 972     DeviceClass *dc = DEVICE_CLASS(klass);
 973     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 974     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 975
 976     dc->props = virtio_scsi_properties;
 977     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 978     vdc->realize = virtio_scsi_device_realize;
 979     vdc->unrealize = virtio_scsi_device_unrealize;
 980     vdc->set_config = virtio_scsi_set_config;
 981     vdc->get_features = virtio_scsi_get_features;
 982     vdc->reset = virtio_scsi_reset;
 983     hc->plug = virtio_scsi_hotplug;
 984     hc->unplug = virtio_scsi_hotunplug;
 985 }
 986
 987 static const TypeInfo virtio_scsi_common_info = {
 988     .name = TYPE_VIRTIO_SCSI_COMMON,
 989     .parent = TYPE_VIRTIO_DEVICE,
 990     .instance_size = sizeof(VirtIOSCSICommon),
 991     .abstract = true,
 992     .class_init = virtio_scsi_common_class_init,
 993 };
 994
 995 static const TypeInfo virtio_scsi_info = {
 996     .name = TYPE_VIRTIO_SCSI,
 997     .parent = TYPE_VIRTIO_SCSI_COMMON,
 998     .instance_size = sizeof(VirtIOSCSI),
 999     .instance_init = virtio_scsi_instance_init,
1000     .class_init = virtio_scsi_class_init,
1001     .interfaces = (InterfaceInfo[]) {
1002         { TYPE_HOTPLUG_HANDLER },
1003         { }
1004     }
1005 };
1006
1007 static void virtio_register_types(void)
1008 {
1009     type_register_static(&virtio_scsi_common_info);
1010     type_register_static(&virtio_scsi_info);
1011 }
1012
1013 type_init(virtio_register_types)