hw/scsi/virtio-scsi.c

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