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_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 149         req_size = req->elem.out_sg[0].iov_len;
 150         resp_size = req->elem.in_sg[0].iov_len;
 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     VirtIOSCSIReq *req = virtio_scsi_init_req(s, vq);
 176     if (!virtqueue_pop(vq, &req->elem)) {
 177         virtio_scsi_free_req(req);
 178         return NULL;
 179     }
 180     return req;
 181 }
 182
 183 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 184 {
 185     VirtIOSCSIReq *req = sreq->hba_private;
 186     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 187     uint32_t n = virtio_queue_get_id(req->vq) - 2;
 188
 189     assert(n < vs->conf.num_queues);
 190     qemu_put_be32s(f, &n);
 191     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 192 }
 193
 194 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 195 {
 196     SCSIBus *bus = sreq->bus;
 197     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 198     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 199     VirtIOSCSIReq *req;
 200     uint32_t n;
 201
 202     qemu_get_be32s(f, &n);
 203     assert(n < vs->conf.num_queues);
 204     req = virtio_scsi_init_req(s, vs->cmd_vqs[n]);
 205     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 206     /* TODO: add a way for SCSIBusInfo's load_request to fail,
 207      * and fail migration instead of asserting here.
 208      * When we do, we might be able to re-enable NDEBUG below.
 209      */
 210 #ifdef NDEBUG
 211 #error building with NDEBUG is not supported
 212 #endif
 213     assert(req->elem.in_num <= ARRAY_SIZE(req->elem.in_sg));
 214     assert(req->elem.out_num <= ARRAY_SIZE(req->elem.out_sg));
 215
 216     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 217                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 218         error_report("invalid SCSI request migration data");
 219         exit(1);
 220     }
 221
 222     scsi_req_ref(sreq);
 223     req->sreq = sreq;
 224     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 225         assert(req->sreq->cmd.mode == req->mode);
 226     }
 227     return req;
 228 }
 229
 230 typedef struct {
 231     Notifier        notifier;
 232     VirtIOSCSIReq  *tmf_req;
 233 } VirtIOSCSICancelNotifier;
 234
 235 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 236 {
 237     VirtIOSCSICancelNotifier *n = container_of(notifier,
 238                                                VirtIOSCSICancelNotifier,
 239                                                notifier);
 240
 241     if (--n->tmf_req->remaining == 0) {
 242         virtio_scsi_complete_req(n->tmf_req);
 243     }
 244     g_slice_free(VirtIOSCSICancelNotifier, n);
 245 }
 246
 247 /* Return 0 if the request is ready to be completed and return to guest;
 248  * -EINPROGRESS if the request is submitted and will be completed later, in the
 249  *  case of async cancellation. */
 250 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 251 {
 252     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 253     SCSIRequest *r, *next;
 254     BusChild *kid;
 255     int target;
 256     int ret = 0;
 257
 258     if (s->dataplane_started && blk_get_aio_context(d->conf.blk) != s->ctx) {
 259         aio_context_acquire(s->ctx);
 260         blk_set_aio_context(d->conf.blk, s->ctx);
 261         aio_context_release(s->ctx);
 262     }
 263     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 264     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 265
 266     virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
 267     switch (req->req.tmf.subtype) {
 268     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 269     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 270         if (!d) {
 271             goto fail;
 272         }
 273         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 274             goto incorrect_lun;
 275         }
 276         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 277             VirtIOSCSIReq *cmd_req = r->hba_private;
 278             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 279                 break;
 280             }
 281         }
 282         if (r) {
 283             /*
 284              * Assert that the request has not been completed yet, we
 285              * check for it in the loop above.
 286              */
 287             assert(r->hba_private);
 288             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 289                 /* "If the specified command is present in the task set, then
 290                  * return a service response set to FUNCTION SUCCEEDED".
 291                  */
 292                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 293             } else {
 294                 VirtIOSCSICancelNotifier *notifier;
 295
 296                 req->remaining = 1;
 297                 notifier = g_slice_new(VirtIOSCSICancelNotifier);
 298                 notifier->tmf_req = req;
 299                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 300                 scsi_req_cancel_async(r, &notifier->notifier);
 301                 ret = -EINPROGRESS;
 302             }
 303         }
 304         break;
 305
 306     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 307         if (!d) {
 308             goto fail;
 309         }
 310         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 311             goto incorrect_lun;
 312         }
 313         s->resetting++;
 314         qdev_reset_all(&d->qdev);
 315         s->resetting--;
 316         break;
 317
 318     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 319     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 320     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 321         if (!d) {
 322             goto fail;
 323         }
 324         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 325             goto incorrect_lun;
 326         }
 327
 328         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 329          * This way, if the bus starts calling back to the notifiers
 330          * even before we finish the loop, virtio_scsi_cancel_notify
 331          * will not complete the TMF too early.
 332          */
 333         req->remaining = 1;
 334         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 335             if (r->hba_private) {
 336                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 337                     /* "If there is any command present in the task set, then
 338                      * return a service response set to FUNCTION SUCCEEDED".
 339                      */
 340                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 341                     break;
 342                 } else {
 343                     VirtIOSCSICancelNotifier *notifier;
 344
 345                     req->remaining++;
 346                     notifier = g_slice_new(VirtIOSCSICancelNotifier);
 347                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 348                     notifier->tmf_req = req;
 349                     scsi_req_cancel_async(r, &notifier->notifier);
 350                 }
 351             }
 352         }
 353         if (--req->remaining > 0) {
 354             ret = -EINPROGRESS;
 355         }
 356         break;
 357
 358     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 359         target = req->req.tmf.lun[1];
 360         s->resetting++;
 361         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 362              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
 363              if (d->channel == 0 && d->id == target) {
 364                 qdev_reset_all(&d->qdev);
 365              }
 366         }
 367         s->resetting--;
 368         break;
 369
 370     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 371     default:
 372         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 373         break;
 374     }
 375
 376     return ret;
 377
 378 incorrect_lun:
 379     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 380     return ret;
 381
 382 fail:
 383     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 384     return ret;
 385 }
 386
 387 void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 388 {
 389     VirtIODevice *vdev = (VirtIODevice *)s;
 390     uint32_t type;
 391     int r = 0;
 392
 393     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 394                 &type, sizeof(type)) < sizeof(type)) {
 395         virtio_scsi_bad_req();
 396         return;
 397     }
 398
 399     virtio_tswap32s(vdev, &type);
 400     if (type == VIRTIO_SCSI_T_TMF) {
 401         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 402                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 403             virtio_scsi_bad_req();
 404         } else {
 405             r = virtio_scsi_do_tmf(s, req);
 406         }
 407
 408     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 409                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 410         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 411                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 412             virtio_scsi_bad_req();
 413         } else {
 414             req->resp.an.event_actual = 0;
 415             req->resp.an.response = VIRTIO_SCSI_S_OK;
 416         }
 417     }
 418     if (r == 0) {
 419         virtio_scsi_complete_req(req);
 420     } else {
 421         assert(r == -EINPROGRESS);
 422     }
 423 }
 424
 425 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 426 {
 427     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 428     VirtIOSCSIReq *req;
 429
 430     if (s->ctx && !s->dataplane_disabled) {
 431         virtio_scsi_dataplane_start(s);
 432         return;
 433     }
 434     while ((req = virtio_scsi_pop_req(s, vq))) {
 435         virtio_scsi_handle_ctrl_req(s, req);
 436     }
 437 }
 438
 439 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 440 {
 441     /* Sense data is not in req->resp and is copied separately
 442      * in virtio_scsi_command_complete.
 443      */
 444     req->resp_size = sizeof(VirtIOSCSICmdResp);
 445     virtio_scsi_complete_req(req);
 446 }
 447
 448 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 449                                          size_t resid)
 450 {
 451     VirtIOSCSIReq *req = r->hba_private;
 452     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 453     uint32_t sense_len;
 454     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 455
 456     if (r->io_canceled) {
 457         return;
 458     }
 459
 460     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 461     req->resp.cmd.status = status;
 462     if (req->resp.cmd.status == GOOD) {
 463         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 464     } else {
 465         req->resp.cmd.resid = 0;
 466         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 467         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 468         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 469                             sense, sense_len);
 470         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 471     }
 472     virtio_scsi_complete_cmd_req(req);
 473 }
 474
 475 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 476                                  uint8_t *buf, void *hba_private)
 477 {
 478     VirtIOSCSIReq *req = hba_private;
 479
 480     if (cmd->len == 0) {
 481         cmd->len = MIN(VIRTIO_SCSI_CDB_SIZE, SCSI_CMD_BUF_SIZE);
 482         memcpy(cmd->buf, buf, cmd->len);
 483     }
 484
 485     /* Extract the direction and mode directly from the request, for
 486      * host device passthrough.
 487      */
 488     cmd->xfer = req->qsgl.size;
 489     cmd->mode = req->mode;
 490     return 0;
 491 }
 492
 493 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 494 {
 495     VirtIOSCSIReq *req = r->hba_private;
 496
 497     return &req->qsgl;
 498 }
 499
 500 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 501 {
 502     VirtIOSCSIReq *req = r->hba_private;
 503
 504     if (!req) {
 505         return;
 506     }
 507     if (req->dev->resetting) {
 508         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 509     } else {
 510         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 511     }
 512     virtio_scsi_complete_cmd_req(req);
 513 }
 514
 515 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 516 {
 517     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 518     virtio_scsi_complete_cmd_req(req);
 519 }
 520
 521 bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 522 {
 523     VirtIOSCSICommon *vs = &s->parent_obj;
 524     SCSIDevice *d;
 525     int rc;
 526
 527     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 528                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 529     if (rc < 0) {
 530         if (rc == -ENOTSUP) {
 531             virtio_scsi_fail_cmd_req(req);
 532         } else {
 533             virtio_scsi_bad_req();
 534         }
 535         return false;
 536     }
 537
 538     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 539     if (!d) {
 540         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 541         virtio_scsi_complete_cmd_req(req);
 542         return false;
 543     }
 544     if (s->dataplane_started && blk_get_aio_context(d->conf.blk) != s->ctx) {
 545         aio_context_acquire(s->ctx);
 546         blk_set_aio_context(d->conf.blk, s->ctx);
 547         aio_context_release(s->ctx);
 548     }
 549     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 550                              virtio_scsi_get_lun(req->req.cmd.lun),
 551                              req->req.cdb, req);
 552
 553     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 554         && (req->sreq->cmd.mode != req->mode ||
 555             req->sreq->cmd.xfer > req->qsgl.size)) {
 556         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 557         virtio_scsi_complete_cmd_req(req);
 558         return false;
 559     }
 560     scsi_req_ref(req->sreq);
 561     blk_io_plug(d->conf.blk);
 562     return true;
 563 }
 564
 565 void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 566 {
 567     SCSIRequest *sreq = req->sreq;
 568     if (scsi_req_enqueue(sreq)) {
 569         scsi_req_continue(sreq);
 570     }
 571     blk_io_unplug(sreq->dev->conf.blk);
 572     scsi_req_unref(sreq);
 573 }
 574
 575 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 576 {
 577     /* use non-QOM casts in the data path */
 578     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 579     VirtIOSCSIReq *req, *next;
 580     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 581
 582     if (s->ctx && !s->dataplane_disabled) {
 583         virtio_scsi_dataplane_start(s);
 584         return;
 585     }
 586     while ((req = virtio_scsi_pop_req(s, vq))) {
 587         if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
 588             QTAILQ_INSERT_TAIL(&reqs, req, next);
 589         }
 590     }
 591
 592     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 593         virtio_scsi_handle_cmd_req_submit(s, req);
 594     }
 595 }
 596
 597 static void virtio_scsi_get_config(VirtIODevice *vdev,
 598                                    uint8_t *config)
 599 {
 600     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 601     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 602
 603     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 604     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 605     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 606     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 607     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 608     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 609     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 610     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 611     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 612     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 613 }
 614
 615 static void virtio_scsi_set_config(VirtIODevice *vdev,
 616                                    const uint8_t *config)
 617 {
 618     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 619     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 620
 621     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 622         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 623         error_report("bad data written to virtio-scsi configuration space");
 624         exit(1);
 625     }
 626
 627     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 628     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 629 }
 630
 631 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
 632                                          uint32_t requested_features)
 633 {
 634     return requested_features;
 635 }
 636
 637 static void virtio_scsi_reset(VirtIODevice *vdev)
 638 {
 639     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 640     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 641
 642     if (s->ctx) {
 643         virtio_scsi_dataplane_stop(s);
 644     }
 645     s->resetting++;
 646     qbus_reset_all(&s->bus.qbus);
 647     s->resetting--;
 648
 649     vs->sense_size = VIRTIO_SCSI_SENSE_SIZE;
 650     vs->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 651     s->events_dropped = false;
 652 }
 653
 654 /* The device does not have anything to save beyond the virtio data.
 655  * Request data is saved with callbacks from SCSI devices.
 656  */
 657 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 658 {
 659     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 660     virtio_save(vdev, f);
 661 }
 662
 663 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 664 {
 665     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 666     int ret;
 667
 668     ret = virtio_load(vdev, f, version_id);
 669     if (ret) {
 670         return ret;
 671     }
 672     return 0;
 673 }
 674
 675 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 676                             uint32_t event, uint32_t reason)
 677 {
 678     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 679     VirtIOSCSIReq *req;
 680     VirtIOSCSIEvent *evt;
 681     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 682
 683     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 684         return;
 685     }
 686
 687     if (s->dataplane_started) {
 688         assert(s->ctx);
 689         aio_context_acquire(s->ctx);
 690     }
 691
 692     if (s->dataplane_started) {
 693         req = virtio_scsi_pop_req_vring(s, s->event_vring);
 694     } else {
 695         req = virtio_scsi_pop_req(s, vs->event_vq);
 696     }
 697     if (!req) {
 698         s->events_dropped = true;
 699         goto out;
 700     }
 701
 702     if (s->events_dropped) {
 703         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 704         s->events_dropped = false;
 705     }
 706
 707     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 708         virtio_scsi_bad_req();
 709     }
 710
 711     evt = &req->resp.event;
 712     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 713     evt->event = virtio_tswap32(vdev, event);
 714     evt->reason = virtio_tswap32(vdev, reason);
 715     if (!dev) {
 716         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 717     } else {
 718         evt->lun[0] = 1;
 719         evt->lun[1] = dev->id;
 720
 721         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 722         if (dev->lun >= 256) {
 723             evt->lun[2] = (dev->lun >> 8) | 0x40;
 724         }
 725         evt->lun[3] = dev->lun & 0xFF;
 726     }
 727     virtio_scsi_complete_req(req);
 728 out:
 729     if (s->dataplane_started) {
 730         aio_context_release(s->ctx);
 731     }
 732 }
 733
 734 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 735 {
 736     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 737
 738     if (s->ctx && !s->dataplane_disabled) {
 739         virtio_scsi_dataplane_start(s);
 740         return;
 741     }
 742     if (s->events_dropped) {
 743         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 744     }
 745 }
 746
 747 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 748 {
 749     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 750     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 751
 752     if (virtio_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 753         dev->type != TYPE_ROM) {
 754         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 755                                sense.asc | (sense.ascq << 8));
 756     }
 757 }
 758
 759 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 760                                 Error **errp)
 761 {
 762     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 763     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 764     SCSIDevice *sd = SCSI_DEVICE(dev);
 765
 766     if (s->ctx && !s->dataplane_disabled) {
 767         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 768             return;
 769         }
 770         blk_op_block_all(sd->conf.blk, s->blocker);
 771     }
 772
 773     if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 774         virtio_scsi_push_event(s, sd,
 775                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 776                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 777     }
 778 }
 779
 780 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 781                                   Error **errp)
 782 {
 783     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 784     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 785     SCSIDevice *sd = SCSI_DEVICE(dev);
 786
 787     if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 788         virtio_scsi_push_event(s, sd,
 789                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 790                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 791     }
 792
 793     if (s->ctx) {
 794         blk_op_unblock_all(sd->conf.blk, s->blocker);
 795     }
 796     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 797 }
 798
 799 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 800     .tcq = true,
 801     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 802     .max_target = VIRTIO_SCSI_MAX_TARGET,
 803     .max_lun = VIRTIO_SCSI_MAX_LUN,
 804
 805     .complete = virtio_scsi_command_complete,
 806     .cancel = virtio_scsi_request_cancelled,
 807     .change = virtio_scsi_change,
 808     .parse_cdb = virtio_scsi_parse_cdb,
 809     .get_sg_list = virtio_scsi_get_sg_list,
 810     .save_request = virtio_scsi_save_request,
 811     .load_request = virtio_scsi_load_request,
 812 };
 813
 814 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 815                                 HandleOutput ctrl, HandleOutput evt,
 816                                 HandleOutput cmd)
 817 {
 818     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 819     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 820     int i;
 821
 822     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 823                 sizeof(VirtIOSCSIConfig));
 824
 825     if (s->conf.num_queues == 0 ||
 826             s->conf.num_queues > VIRTIO_PCI_QUEUE_MAX - 2) {
 827         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 828                          "must be a positive integer less than %d.",
 829                    s->conf.num_queues, VIRTIO_PCI_QUEUE_MAX - 2);
 830         virtio_cleanup(vdev);
 831         return;
 832     }
 833     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 834     s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
 835     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 836
 837     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 838                                   ctrl);
 839     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 840                                    evt);
 841     for (i = 0; i < s->conf.num_queues; i++) {
 842         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 843                                          cmd);
 844     }
 845
 846     if (s->conf.iothread) {
 847         virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
 848     }
 849 }
 850
 851 /* Disable dataplane thread during live migration since it does not
 852  * update the dirty memory bitmap yet.
 853  */
 854 static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
 855 {
 856     VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
 857                                  migration_state_notifier);
 858     MigrationState *mig = data;
 859
 860     if (migration_in_setup(mig)) {
 861         if (!s->dataplane_started) {
 862             return;
 863         }
 864         virtio_scsi_dataplane_stop(s);
 865         s->dataplane_disabled = true;
 866     } else if (migration_has_finished(mig) ||
 867                migration_has_failed(mig)) {
 868         if (s->dataplane_started) {
 869             return;
 870         }
 871         blk_drain_all(); /* complete in-flight non-dataplane requests */
 872         s->dataplane_disabled = false;
 873     }
 874 }
 875
 876 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 877 {
 878     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 879     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 880     static int virtio_scsi_id;
 881     Error *err = NULL;
 882
 883     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 884                                virtio_scsi_handle_event,
 885                                virtio_scsi_handle_cmd);
 886     if (err != NULL) {
 887         error_propagate(errp, err);
 888         return;
 889     }
 890
 891     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 892                  &virtio_scsi_scsi_info, vdev->bus_name);
 893     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 894     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 895
 896     if (!dev->hotplugged) {
 897         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 898         if (err != NULL) {
 899             error_propagate(errp, err);
 900             return;
 901         }
 902     }
 903
 904     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 905                     virtio_scsi_save, virtio_scsi_load, s);
 906     s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
 907     add_migration_state_change_notifier(&s->migration_state_notifier);
 908 }
 909
 910 static void virtio_scsi_instance_init(Object *obj)
 911 {
 912     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 913
 914     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 915                              (Object **)&vs->conf.iothread,
 916                              qdev_prop_allow_set_link_before_realize,
 917                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 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     unregister_savevm(dev, "virtio-scsi", s);
 934     remove_migration_state_change_notifier(&s->migration_state_notifier);
 935
 936     virtio_scsi_common_unrealize(dev, errp);
 937 }
 938
 939 static Property virtio_scsi_properties[] = {
 940     DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOSCSI, parent_obj.conf),
 941     DEFINE_PROP_END_OF_LIST(),
 942 };
 943
 944 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 945 {
 946     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 947     DeviceClass *dc = DEVICE_CLASS(klass);
 948
 949     vdc->get_config = virtio_scsi_get_config;
 950     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 951 }
 952
 953 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 954 {
 955     DeviceClass *dc = DEVICE_CLASS(klass);
 956     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 957     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 958
 959     dc->props = virtio_scsi_properties;
 960     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 961     vdc->realize = virtio_scsi_device_realize;
 962     vdc->unrealize = virtio_scsi_device_unrealize;
 963     vdc->set_config = virtio_scsi_set_config;
 964     vdc->get_features = virtio_scsi_get_features;
 965     vdc->reset = virtio_scsi_reset;
 966     hc->plug = virtio_scsi_hotplug;
 967     hc->unplug = virtio_scsi_hotunplug;
 968 }
 969
 970 static const TypeInfo virtio_scsi_common_info = {
 971     .name = TYPE_VIRTIO_SCSI_COMMON,
 972     .parent = TYPE_VIRTIO_DEVICE,
 973     .instance_size = sizeof(VirtIOSCSICommon),
 974     .abstract = true,
 975     .class_init = virtio_scsi_common_class_init,
 976 };
 977
 978 static const TypeInfo virtio_scsi_info = {
 979     .name = TYPE_VIRTIO_SCSI,
 980     .parent = TYPE_VIRTIO_SCSI_COMMON,
 981     .instance_size = sizeof(VirtIOSCSI),
 982     .instance_init = virtio_scsi_instance_init,
 983     .class_init = virtio_scsi_class_init,
 984     .interfaces = (InterfaceInfo[]) {
 985         { TYPE_HOTPLUG_HANDLER },
 986         { }
 987     }
 988 };
 989
 990 static void virtio_register_types(void)
 991 {
 992     type_register_static(&virtio_scsi_common_info);
 993     type_register_static(&virtio_scsi_info);
 994 }
 995
 996 type_init(virtio_register_types)