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 "migration/qemu-file-types.h"
  21 #include "qemu/error-report.h"
  22 #include "qemu/iov.h"
  23 #include "qemu/module.h"
  24 #include "sysemu/block-backend.h"
  25 #include "hw/qdev-properties.h"
  26 #include "hw/scsi/scsi.h"
  27 #include "scsi/constants.h"
  28 #include "hw/virtio/virtio-bus.h"
  29 #include "hw/virtio/virtio-access.h"
  30
  31 static inline int virtio_scsi_get_lun(uint8_t *lun)
  32 {
  33     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  34 }
  35
  36 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  37 {
  38     if (lun[0] != 1) {
  39         return NULL;
  40     }
  41     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  42         return NULL;
  43     }
  44     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  45 }
  46
  47 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  48 {
  49     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  50     const size_t zero_skip =
  51         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  52
  53     req->vq = vq;
  54     req->dev = s;
  55     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
  56     qemu_iovec_init(&req->resp_iov, 1);
  57     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  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     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  75     if (s->dataplane_started && !s->dataplane_fenced) {
  76         virtio_notify_irqfd(vdev, vq);
  77     } else {
  78         virtio_notify(vdev, vq);
  79     }
  80
  81     if (req->sreq) {
  82         req->sreq->hba_private = NULL;
  83         scsi_req_unref(req->sreq);
  84     }
  85     virtio_scsi_free_req(req);
  86 }
  87
  88 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
  89 {
  90     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
  91     virtqueue_detach_element(req->vq, &req->elem, 0);
  92     virtio_scsi_free_req(req);
  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     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 179     VirtIOSCSIReq *req;
 180
 181     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 182     if (!req) {
 183         return NULL;
 184     }
 185     virtio_scsi_init_req(s, vq, req);
 186     return req;
 187 }
 188
 189 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 190 {
 191     VirtIOSCSIReq *req = sreq->hba_private;
 192     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 193     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 194     uint32_t n = virtio_get_queue_index(req->vq) - 2;
 195
 196     assert(n < vs->conf.num_queues);
 197     qemu_put_be32s(f, &n);
 198     qemu_put_virtqueue_element(vdev, f, &req->elem);
 199 }
 200
 201 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 202 {
 203     SCSIBus *bus = sreq->bus;
 204     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 205     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 206     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 207     VirtIOSCSIReq *req;
 208     uint32_t n;
 209
 210     qemu_get_be32s(f, &n);
 211     assert(n < vs->conf.num_queues);
 212     req = qemu_get_virtqueue_element(vdev, f,
 213                                      sizeof(VirtIOSCSIReq) + vs->cdb_size);
 214     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 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_free(n);
 245 }
 246
 247 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
 248 {
 249     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
 250         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 251     }
 252 }
 253
 254 /* Return 0 if the request is ready to be completed and return to guest;
 255  * -EINPROGRESS if the request is submitted and will be completed later, in the
 256  *  case of async cancellation. */
 257 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 258 {
 259     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 260     SCSIRequest *r, *next;
 261     BusChild *kid;
 262     int target;
 263     int ret = 0;
 264
 265     virtio_scsi_ctx_check(s, d);
 266     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 267     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 268
 269     /*
 270      * req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
 271      * to avoid compiler errors.
 272      */
 273     req->req.tmf.subtype =
 274         virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
 275
 276     switch (req->req.tmf.subtype) {
 277     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 278     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 279         if (!d) {
 280             goto fail;
 281         }
 282         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 283             goto incorrect_lun;
 284         }
 285         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 286             VirtIOSCSIReq *cmd_req = r->hba_private;
 287             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 288                 break;
 289             }
 290         }
 291         if (r) {
 292             /*
 293              * Assert that the request has not been completed yet, we
 294              * check for it in the loop above.
 295              */
 296             assert(r->hba_private);
 297             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 298                 /* "If the specified command is present in the task set, then
 299                  * return a service response set to FUNCTION SUCCEEDED".
 300                  */
 301                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 302             } else {
 303                 VirtIOSCSICancelNotifier *notifier;
 304
 305                 req->remaining = 1;
 306                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 307                 notifier->tmf_req = req;
 308                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 309                 scsi_req_cancel_async(r, &notifier->notifier);
 310                 ret = -EINPROGRESS;
 311             }
 312         }
 313         break;
 314
 315     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 316         if (!d) {
 317             goto fail;
 318         }
 319         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 320             goto incorrect_lun;
 321         }
 322         s->resetting++;
 323         qdev_reset_all(&d->qdev);
 324         s->resetting--;
 325         break;
 326
 327     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 328     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 329     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 330         if (!d) {
 331             goto fail;
 332         }
 333         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 334             goto incorrect_lun;
 335         }
 336
 337         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 338          * This way, if the bus starts calling back to the notifiers
 339          * even before we finish the loop, virtio_scsi_cancel_notify
 340          * will not complete the TMF too early.
 341          */
 342         req->remaining = 1;
 343         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 344             if (r->hba_private) {
 345                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 346                     /* "If there is any command present in the task set, then
 347                      * return a service response set to FUNCTION SUCCEEDED".
 348                      */
 349                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 350                     break;
 351                 } else {
 352                     VirtIOSCSICancelNotifier *notifier;
 353
 354                     req->remaining++;
 355                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 356                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 357                     notifier->tmf_req = req;
 358                     scsi_req_cancel_async(r, &notifier->notifier);
 359                 }
 360             }
 361         }
 362         if (--req->remaining > 0) {
 363             ret = -EINPROGRESS;
 364         }
 365         break;
 366
 367     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 368         target = req->req.tmf.lun[1];
 369         s->resetting++;
 370         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 371              d = SCSI_DEVICE(kid->child);
 372              if (d->channel == 0 && d->id == target) {
 373                 qdev_reset_all(&d->qdev);
 374              }
 375         }
 376         s->resetting--;
 377         break;
 378
 379     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 380     default:
 381         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 382         break;
 383     }
 384
 385     return ret;
 386
 387 incorrect_lun:
 388     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 389     return ret;
 390
 391 fail:
 392     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 393     return ret;
 394 }
 395
 396 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 397 {
 398     VirtIODevice *vdev = (VirtIODevice *)s;
 399     uint32_t type;
 400     int r = 0;
 401
 402     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 403                 &type, sizeof(type)) < sizeof(type)) {
 404         virtio_scsi_bad_req(req);
 405         return;
 406     }
 407
 408     virtio_tswap32s(vdev, &type);
 409     if (type == VIRTIO_SCSI_T_TMF) {
 410         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 411                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 412             virtio_scsi_bad_req(req);
 413             return;
 414         } else {
 415             r = virtio_scsi_do_tmf(s, req);
 416         }
 417
 418     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 419                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 420         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 421                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 422             virtio_scsi_bad_req(req);
 423             return;
 424         } else {
 425             req->resp.an.event_actual = 0;
 426             req->resp.an.response = VIRTIO_SCSI_S_OK;
 427         }
 428     }
 429     if (r == 0) {
 430         virtio_scsi_complete_req(req);
 431     } else {
 432         assert(r == -EINPROGRESS);
 433     }
 434 }
 435
 436 bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 437 {
 438     VirtIOSCSIReq *req;
 439     bool progress = false;
 440
 441     while ((req = virtio_scsi_pop_req(s, vq))) {
 442         progress = true;
 443         virtio_scsi_handle_ctrl_req(s, req);
 444     }
 445     return progress;
 446 }
 447
 448 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 449 {
 450     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 451
 452     if (s->ctx) {
 453         virtio_device_start_ioeventfd(vdev);
 454         if (!s->dataplane_fenced) {
 455             return;
 456         }
 457     }
 458     virtio_scsi_acquire(s);
 459     virtio_scsi_handle_ctrl_vq(s, vq);
 460     virtio_scsi_release(s);
 461 }
 462
 463 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 464 {
 465     /* Sense data is not in req->resp and is copied separately
 466      * in virtio_scsi_command_complete.
 467      */
 468     req->resp_size = sizeof(VirtIOSCSICmdResp);
 469     virtio_scsi_complete_req(req);
 470 }
 471
 472 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 473                                          size_t resid)
 474 {
 475     VirtIOSCSIReq *req = r->hba_private;
 476     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 477     uint32_t sense_len;
 478     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 479
 480     if (r->io_canceled) {
 481         return;
 482     }
 483
 484     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 485     req->resp.cmd.status = status;
 486     if (req->resp.cmd.status == GOOD) {
 487         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 488     } else {
 489         req->resp.cmd.resid = 0;
 490         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 491         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 492         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 493                             sense, sense_len);
 494         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 495     }
 496     virtio_scsi_complete_cmd_req(req);
 497 }
 498
 499 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 500                                  uint8_t *buf, void *hba_private)
 501 {
 502     VirtIOSCSIReq *req = hba_private;
 503
 504     if (cmd->len == 0) {
 505         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 506         memcpy(cmd->buf, buf, cmd->len);
 507     }
 508
 509     /* Extract the direction and mode directly from the request, for
 510      * host device passthrough.
 511      */
 512     cmd->xfer = req->qsgl.size;
 513     cmd->mode = req->mode;
 514     return 0;
 515 }
 516
 517 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 518 {
 519     VirtIOSCSIReq *req = r->hba_private;
 520
 521     return &req->qsgl;
 522 }
 523
 524 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 525 {
 526     VirtIOSCSIReq *req = r->hba_private;
 527
 528     if (!req) {
 529         return;
 530     }
 531     if (req->dev->resetting) {
 532         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 533     } else {
 534         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 535     }
 536     virtio_scsi_complete_cmd_req(req);
 537 }
 538
 539 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 540 {
 541     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 542     virtio_scsi_complete_cmd_req(req);
 543 }
 544
 545 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 546 {
 547     VirtIOSCSICommon *vs = &s->parent_obj;
 548     SCSIDevice *d;
 549     int rc;
 550
 551     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 552                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 553     if (rc < 0) {
 554         if (rc == -ENOTSUP) {
 555             virtio_scsi_fail_cmd_req(req);
 556             return -ENOTSUP;
 557         } else {
 558             virtio_scsi_bad_req(req);
 559             return -EINVAL;
 560         }
 561     }
 562
 563     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 564     if (!d) {
 565         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 566         virtio_scsi_complete_cmd_req(req);
 567         return -ENOENT;
 568     }
 569     virtio_scsi_ctx_check(s, d);
 570     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 571                              virtio_scsi_get_lun(req->req.cmd.lun),
 572                              req->req.cmd.cdb, req);
 573
 574     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 575         && (req->sreq->cmd.mode != req->mode ||
 576             req->sreq->cmd.xfer > req->qsgl.size)) {
 577         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 578         virtio_scsi_complete_cmd_req(req);
 579         return -ENOBUFS;
 580     }
 581     scsi_req_ref(req->sreq);
 582     blk_io_plug(d->conf.blk);
 583     return 0;
 584 }
 585
 586 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 587 {
 588     SCSIRequest *sreq = req->sreq;
 589     if (scsi_req_enqueue(sreq)) {
 590         scsi_req_continue(sreq);
 591     }
 592     blk_io_unplug(sreq->dev->conf.blk);
 593     scsi_req_unref(sreq);
 594 }
 595
 596 bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 597 {
 598     VirtIOSCSIReq *req, *next;
 599     int ret = 0;
 600     bool suppress_notifications = virtio_queue_get_notification(vq);
 601     bool progress = false;
 602
 603     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 604
 605     do {
 606         if (suppress_notifications) {
 607             virtio_queue_set_notification(vq, 0);
 608         }
 609
 610         while ((req = virtio_scsi_pop_req(s, vq))) {
 611             progress = true;
 612             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 613             if (!ret) {
 614                 QTAILQ_INSERT_TAIL(&reqs, req, next);
 615             } else if (ret == -EINVAL) {
 616                 /* The device is broken and shouldn't process any request */
 617                 while (!QTAILQ_EMPTY(&reqs)) {
 618                     req = QTAILQ_FIRST(&reqs);
 619                     QTAILQ_REMOVE(&reqs, req, next);
 620                     blk_io_unplug(req->sreq->dev->conf.blk);
 621                     scsi_req_unref(req->sreq);
 622                     virtqueue_detach_element(req->vq, &req->elem, 0);
 623                     virtio_scsi_free_req(req);
 624                 }
 625             }
 626         }
 627
 628         if (suppress_notifications) {
 629             virtio_queue_set_notification(vq, 1);
 630         }
 631     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 632
 633     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 634         virtio_scsi_handle_cmd_req_submit(s, req);
 635     }
 636     return progress;
 637 }
 638
 639 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 640 {
 641     /* use non-QOM casts in the data path */
 642     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 643
 644     if (s->ctx) {
 645         virtio_device_start_ioeventfd(vdev);
 646         if (!s->dataplane_fenced) {
 647             return;
 648         }
 649     }
 650     virtio_scsi_acquire(s);
 651     virtio_scsi_handle_cmd_vq(s, vq);
 652     virtio_scsi_release(s);
 653 }
 654
 655 static void virtio_scsi_get_config(VirtIODevice *vdev,
 656                                    uint8_t *config)
 657 {
 658     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 659     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 660
 661     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 662     virtio_stl_p(vdev, &scsiconf->seg_max,
 663                  s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
 664     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 665     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 666     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 667     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 668     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 669     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 670     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 671     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 672 }
 673
 674 static void virtio_scsi_set_config(VirtIODevice *vdev,
 675                                    const uint8_t *config)
 676 {
 677     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 678     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 679
 680     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 681         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 682         virtio_error(vdev,
 683                      "bad data written to virtio-scsi configuration space");
 684         return;
 685     }
 686
 687     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 688     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 689 }
 690
 691 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 692                                          uint64_t requested_features,
 693                                          Error **errp)
 694 {
 695     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 696
 697     /* Firstly sync all virtio-scsi possible supported features */
 698     requested_features |= s->host_features;
 699     return requested_features;
 700 }
 701
 702 static void virtio_scsi_reset(VirtIODevice *vdev)
 703 {
 704     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 705     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 706
 707     assert(!s->dataplane_started);
 708     s->resetting++;
 709     qbus_reset_all(BUS(&s->bus));
 710     s->resetting--;
 711
 712     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 713     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 714     s->events_dropped = false;
 715 }
 716
 717 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 718                             uint32_t event, uint32_t reason)
 719 {
 720     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 721     VirtIOSCSIReq *req;
 722     VirtIOSCSIEvent *evt;
 723     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 724
 725     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 726         return;
 727     }
 728
 729     req = virtio_scsi_pop_req(s, vs->event_vq);
 730     if (!req) {
 731         s->events_dropped = true;
 732         return;
 733     }
 734
 735     if (s->events_dropped) {
 736         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 737         s->events_dropped = false;
 738     }
 739
 740     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 741         virtio_scsi_bad_req(req);
 742         return;
 743     }
 744
 745     evt = &req->resp.event;
 746     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 747     evt->event = virtio_tswap32(vdev, event);
 748     evt->reason = virtio_tswap32(vdev, reason);
 749     if (!dev) {
 750         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 751     } else {
 752         evt->lun[0] = 1;
 753         evt->lun[1] = dev->id;
 754
 755         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 756         if (dev->lun >= 256) {
 757             evt->lun[2] = (dev->lun >> 8) | 0x40;
 758         }
 759         evt->lun[3] = dev->lun & 0xFF;
 760     }
 761     virtio_scsi_complete_req(req);
 762 }
 763
 764 bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 765 {
 766     if (s->events_dropped) {
 767         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 768         return true;
 769     }
 770     return false;
 771 }
 772
 773 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 774 {
 775     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 776
 777     if (s->ctx) {
 778         virtio_device_start_ioeventfd(vdev);
 779         if (!s->dataplane_fenced) {
 780             return;
 781         }
 782     }
 783     virtio_scsi_acquire(s);
 784     virtio_scsi_handle_event_vq(s, vq);
 785     virtio_scsi_release(s);
 786 }
 787
 788 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 789 {
 790     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 791     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 792
 793     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 794         dev->type != TYPE_ROM) {
 795         virtio_scsi_acquire(s);
 796         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 797                                sense.asc | (sense.ascq << 8));
 798         virtio_scsi_release(s);
 799     }
 800 }
 801
 802 static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
 803                                     DeviceState *dev, Error **errp)
 804 {
 805     SCSIDevice *sd = SCSI_DEVICE(dev);
 806     sd->hba_supports_iothread = true;
 807 }
 808
 809 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 810                                 Error **errp)
 811 {
 812     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 813     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 814     SCSIDevice *sd = SCSI_DEVICE(dev);
 815     int ret;
 816
 817     if (s->ctx && !s->dataplane_fenced) {
 818         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 819             return;
 820         }
 821         virtio_scsi_acquire(s);
 822         ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
 823         virtio_scsi_release(s);
 824         if (ret < 0) {
 825             return;
 826         }
 827     }
 828
 829     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 830         virtio_scsi_acquire(s);
 831         virtio_scsi_push_event(s, sd,
 832                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 833                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 834         virtio_scsi_release(s);
 835     }
 836 }
 837
 838 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 839                                   Error **errp)
 840 {
 841     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 842     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 843     SCSIDevice *sd = SCSI_DEVICE(dev);
 844     AioContext *ctx = s->ctx ?: qemu_get_aio_context();
 845
 846     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 847         virtio_scsi_acquire(s);
 848         virtio_scsi_push_event(s, sd,
 849                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 850                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 851         virtio_scsi_release(s);
 852     }
 853
 854     aio_disable_external(ctx);
 855     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 856     aio_enable_external(ctx);
 857
 858     if (s->ctx) {
 859         virtio_scsi_acquire(s);
 860         /* If other users keep the BlockBackend in the iothread, that's ok */
 861         blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
 862         virtio_scsi_release(s);
 863     }
 864 }
 865
 866 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 867     .tcq = true,
 868     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 869     .max_target = VIRTIO_SCSI_MAX_TARGET,
 870     .max_lun = VIRTIO_SCSI_MAX_LUN,
 871
 872     .complete = virtio_scsi_command_complete,
 873     .cancel = virtio_scsi_request_cancelled,
 874     .change = virtio_scsi_change,
 875     .parse_cdb = virtio_scsi_parse_cdb,
 876     .get_sg_list = virtio_scsi_get_sg_list,
 877     .save_request = virtio_scsi_save_request,
 878     .load_request = virtio_scsi_load_request,
 879 };
 880
 881 void virtio_scsi_common_realize(DeviceState *dev,
 882                                 VirtIOHandleOutput ctrl,
 883                                 VirtIOHandleOutput evt,
 884                                 VirtIOHandleOutput cmd,
 885                                 Error **errp)
 886 {
 887     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 888     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 889     int i;
 890
 891     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 892                 sizeof(VirtIOSCSIConfig));
 893
 894     if (s->conf.num_queues == 0 ||
 895             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 896         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 897                          "must be a positive integer less than %d.",
 898                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 899         virtio_cleanup(vdev);
 900         return;
 901     }
 902     if (s->conf.virtqueue_size <= 2) {
 903         error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
 904                    "must be > 2", s->conf.virtqueue_size);
 905         return;
 906     }
 907     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 908     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 909     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 910
 911     s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
 912     s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
 913     for (i = 0; i < s->conf.num_queues; i++) {
 914         s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
 915     }
 916 }
 917
 918 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 919 {
 920     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 921     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 922     Error *err = NULL;
 923
 924     virtio_scsi_common_realize(dev,
 925                                virtio_scsi_handle_ctrl,
 926                                virtio_scsi_handle_event,
 927                                virtio_scsi_handle_cmd,
 928                                &err);
 929     if (err != NULL) {
 930         error_propagate(errp, err);
 931         return;
 932     }
 933
 934     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 935                  &virtio_scsi_scsi_info, vdev->bus_name);
 936     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 937     qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev), &error_abort);
 938
 939     virtio_scsi_dataplane_setup(s, errp);
 940 }
 941
 942 void virtio_scsi_common_unrealize(DeviceState *dev)
 943 {
 944     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 945     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 946     int i;
 947
 948     virtio_delete_queue(vs->ctrl_vq);
 949     virtio_delete_queue(vs->event_vq);
 950     for (i = 0; i < vs->conf.num_queues; i++) {
 951         virtio_delete_queue(vs->cmd_vqs[i]);
 952     }
 953     g_free(vs->cmd_vqs);
 954     virtio_cleanup(vdev);
 955 }
 956
 957 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 958 {
 959     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 960
 961     qbus_set_hotplug_handler(BUS(&s->bus), NULL, &error_abort);
 962     virtio_scsi_common_unrealize(dev);
 963 }
 964
 965 static Property virtio_scsi_properties[] = {
 966     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 967     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
 968                                          parent_obj.conf.virtqueue_size, 256),
 969     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
 970                       parent_obj.conf.seg_max_adjust, true),
 971     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 972                                                   0xFFFF),
 973     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 974                                                   128),
 975     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 976                                            VIRTIO_SCSI_F_HOTPLUG, true),
 977     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 978                                                 VIRTIO_SCSI_F_CHANGE, true),
 979     DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
 980                      TYPE_IOTHREAD, IOThread *),
 981     DEFINE_PROP_END_OF_LIST(),
 982 };
 983
 984 static const VMStateDescription vmstate_virtio_scsi = {
 985     .name = "virtio-scsi",
 986     .minimum_version_id = 1,
 987     .version_id = 1,
 988     .fields = (VMStateField[]) {
 989         VMSTATE_VIRTIO_DEVICE,
 990         VMSTATE_END_OF_LIST()
 991     },
 992 };
 993
 994 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 995 {
 996     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 997     DeviceClass *dc = DEVICE_CLASS(klass);
 998
 999     vdc->get_config = virtio_scsi_get_config;
1000     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1001 }
1002
1003 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
1004 {
1005     DeviceClass *dc = DEVICE_CLASS(klass);
1006     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1007     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1008
1009     device_class_set_props(dc, virtio_scsi_properties);
1010     dc->vmsd = &vmstate_virtio_scsi;
1011     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1012     vdc->realize = virtio_scsi_device_realize;
1013     vdc->unrealize = virtio_scsi_device_unrealize;
1014     vdc->set_config = virtio_scsi_set_config;
1015     vdc->get_features = virtio_scsi_get_features;
1016     vdc->reset = virtio_scsi_reset;
1017     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
1018     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
1019     hc->pre_plug = virtio_scsi_pre_hotplug;
1020     hc->plug = virtio_scsi_hotplug;
1021     hc->unplug = virtio_scsi_hotunplug;
1022 }
1023
1024 static const TypeInfo virtio_scsi_common_info = {
1025     .name = TYPE_VIRTIO_SCSI_COMMON,
1026     .parent = TYPE_VIRTIO_DEVICE,
1027     .instance_size = sizeof(VirtIOSCSICommon),
1028     .abstract = true,
1029     .class_init = virtio_scsi_common_class_init,
1030 };
1031
1032 static const TypeInfo virtio_scsi_info = {
1033     .name = TYPE_VIRTIO_SCSI,
1034     .parent = TYPE_VIRTIO_SCSI_COMMON,
1035     .instance_size = sizeof(VirtIOSCSI),
1036     .class_init = virtio_scsi_class_init,
1037     .interfaces = (InterfaceInfo[]) {
1038         { TYPE_HOTPLUG_HANDLER },
1039         { }
1040     }
1041 };
1042
1043 static void virtio_register_types(void)
1044 {
1045     type_register_static(&virtio_scsi_common_info);
1046     type_register_static(&virtio_scsi_info);
1047 }
1048
1049 type_init(virtio_register_types)