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 #define VMSTATE_VIRTIO_DEVICE_USE_NEW
  17
  18 #include "qemu/osdep.h"
  19 #include "qapi/error.h"
  20 #include "standard-headers/linux/virtio_ids.h"
  21 #include "hw/virtio/virtio-scsi.h"
  22 #include "qemu/error-report.h"
  23 #include "qemu/iov.h"
  24 #include "sysemu/block-backend.h"
  25 #include "hw/scsi/scsi.h"
  26 #include "block/scsi.h"
  27 #include "hw/virtio/virtio-bus.h"
  28 #include "hw/virtio/virtio-access.h"
  29
  30 static inline int virtio_scsi_get_lun(uint8_t *lun)
  31 {
  32     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  33 }
  34
  35 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  36 {
  37     if (lun[0] != 1) {
  38         return NULL;
  39     }
  40     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  41         return NULL;
  42     }
  43     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  44 }
  45
  46 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  47 {
  48     const size_t zero_skip =
  49         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  50
  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 }
  57
  58 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  59 {
  60     qemu_iovec_destroy(&req->resp_iov);
  61     qemu_sglist_destroy(&req->qsgl);
  62     g_free(req);
  63 }
  64
  65 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  66 {
  67     VirtIOSCSI *s = req->dev;
  68     VirtQueue *vq = req->vq;
  69     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  70
  71     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  72     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  73     if (s->dataplane_started && !s->dataplane_fenced) {
  74         virtio_scsi_dataplane_notify(vdev, req);
  75     } else {
  76         virtio_notify(vdev, vq);
  77     }
  78
  79     if (req->sreq) {
  80         req->sreq->hba_private = NULL;
  81         scsi_req_unref(req->sreq);
  82     }
  83     virtio_scsi_free_req(req);
  84 }
  85
  86 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
  87 {
  88     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
  89     virtqueue_detach_element(req->vq, &req->elem, 0);
  90     virtio_scsi_free_req(req);
  91 }
  92
  93 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  94                               hwaddr *addr, int num, size_t skip)
  95 {
  96     QEMUSGList *qsgl = &req->qsgl;
  97     size_t copied = 0;
  98
  99     while (num) {
 100         if (skip >= iov->iov_len) {
 101             skip -= iov->iov_len;
 102         } else {
 103             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 104             copied += iov->iov_len - skip;
 105             skip = 0;
 106         }
 107         iov++;
 108         addr++;
 109         num--;
 110     }
 111
 112     assert(skip == 0);
 113     return copied;
 114 }
 115
 116 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 117                                  unsigned req_size, unsigned resp_size)
 118 {
 119     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 120     size_t in_size, out_size;
 121
 122     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 123                    &req->req, req_size) < req_size) {
 124         return -EINVAL;
 125     }
 126
 127     if (qemu_iovec_concat_iov(&req->resp_iov,
 128                               req->elem.in_sg, req->elem.in_num, 0,
 129                               resp_size) < resp_size) {
 130         return -EINVAL;
 131     }
 132
 133     req->resp_size = resp_size;
 134
 135     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 136      * As a workaround, always consider the first buffer as the virtio-scsi
 137      * request/response, making the payload start at the second element
 138      * of the iovec.
 139      *
 140      * The actual length of the response header, stored in req->resp_size,
 141      * does not change.
 142      *
 143      * TODO: always disable this workaround for virtio 1.0 devices.
 144      */
 145     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 146         if (req->elem.out_num) {
 147             req_size = req->elem.out_sg[0].iov_len;
 148         }
 149         if (req->elem.in_num) {
 150             resp_size = req->elem.in_sg[0].iov_len;
 151         }
 152     }
 153
 154     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 155                                &req->elem.out_addr[0], req->elem.out_num,
 156                                req_size);
 157     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 158                               &req->elem.in_addr[0], req->elem.in_num,
 159                               resp_size);
 160
 161     if (out_size && in_size) {
 162         return -ENOTSUP;
 163     }
 164
 165     if (out_size) {
 166         req->mode = SCSI_XFER_TO_DEV;
 167     } else if (in_size) {
 168         req->mode = SCSI_XFER_FROM_DEV;
 169     }
 170
 171     return 0;
 172 }
 173
 174 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 175 {
 176     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 177     VirtIOSCSIReq *req;
 178
 179     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 180     if (!req) {
 181         return NULL;
 182     }
 183     virtio_scsi_init_req(s, vq, req);
 184     return req;
 185 }
 186
 187 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 188 {
 189     VirtIOSCSIReq *req = sreq->hba_private;
 190     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 191     uint32_t n = virtio_get_queue_index(req->vq) - 2;
 192
 193     assert(n < vs->conf.num_queues);
 194     qemu_put_be32s(f, &n);
 195     qemu_put_virtqueue_element(f, &req->elem);
 196 }
 197
 198 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 199 {
 200     SCSIBus *bus = sreq->bus;
 201     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 202     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 203     VirtIOSCSIReq *req;
 204     uint32_t n;
 205
 206     qemu_get_be32s(f, &n);
 207     assert(n < vs->conf.num_queues);
 208     req = qemu_get_virtqueue_element(f, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 209     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 210
 211     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 212                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 213         error_report("invalid SCSI request migration data");
 214         exit(1);
 215     }
 216
 217     scsi_req_ref(sreq);
 218     req->sreq = sreq;
 219     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 220         assert(req->sreq->cmd.mode == req->mode);
 221     }
 222     return req;
 223 }
 224
 225 typedef struct {
 226     Notifier        notifier;
 227     VirtIOSCSIReq  *tmf_req;
 228 } VirtIOSCSICancelNotifier;
 229
 230 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 231 {
 232     VirtIOSCSICancelNotifier *n = container_of(notifier,
 233                                                VirtIOSCSICancelNotifier,
 234                                                notifier);
 235
 236     if (--n->tmf_req->remaining == 0) {
 237         virtio_scsi_complete_req(n->tmf_req);
 238     }
 239     g_free(n);
 240 }
 241
 242 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
 243 {
 244     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
 245         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 246     }
 247 }
 248
 249 /* Return 0 if the request is ready to be completed and return to guest;
 250  * -EINPROGRESS if the request is submitted and will be completed later, in the
 251  *  case of async cancellation. */
 252 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 253 {
 254     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 255     SCSIRequest *r, *next;
 256     BusChild *kid;
 257     int target;
 258     int ret = 0;
 259
 260     virtio_scsi_ctx_check(s, d);
 261     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 262     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 263
 264     virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
 265     switch (req->req.tmf.subtype) {
 266     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 267     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 268         if (!d) {
 269             goto fail;
 270         }
 271         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 272             goto incorrect_lun;
 273         }
 274         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 275             VirtIOSCSIReq *cmd_req = r->hba_private;
 276             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 277                 break;
 278             }
 279         }
 280         if (r) {
 281             /*
 282              * Assert that the request has not been completed yet, we
 283              * check for it in the loop above.
 284              */
 285             assert(r->hba_private);
 286             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 287                 /* "If the specified command is present in the task set, then
 288                  * return a service response set to FUNCTION SUCCEEDED".
 289                  */
 290                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 291             } else {
 292                 VirtIOSCSICancelNotifier *notifier;
 293
 294                 req->remaining = 1;
 295                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 296                 notifier->tmf_req = req;
 297                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 298                 scsi_req_cancel_async(r, &notifier->notifier);
 299                 ret = -EINPROGRESS;
 300             }
 301         }
 302         break;
 303
 304     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 305         if (!d) {
 306             goto fail;
 307         }
 308         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 309             goto incorrect_lun;
 310         }
 311         s->resetting++;
 312         qdev_reset_all(&d->qdev);
 313         s->resetting--;
 314         break;
 315
 316     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 317     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 318     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 319         if (!d) {
 320             goto fail;
 321         }
 322         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 323             goto incorrect_lun;
 324         }
 325
 326         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 327          * This way, if the bus starts calling back to the notifiers
 328          * even before we finish the loop, virtio_scsi_cancel_notify
 329          * will not complete the TMF too early.
 330          */
 331         req->remaining = 1;
 332         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 333             if (r->hba_private) {
 334                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 335                     /* "If there is any command present in the task set, then
 336                      * return a service response set to FUNCTION SUCCEEDED".
 337                      */
 338                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 339                     break;
 340                 } else {
 341                     VirtIOSCSICancelNotifier *notifier;
 342
 343                     req->remaining++;
 344                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 345                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 346                     notifier->tmf_req = req;
 347                     scsi_req_cancel_async(r, &notifier->notifier);
 348                 }
 349             }
 350         }
 351         if (--req->remaining > 0) {
 352             ret = -EINPROGRESS;
 353         }
 354         break;
 355
 356     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 357         target = req->req.tmf.lun[1];
 358         s->resetting++;
 359         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 360              d = SCSI_DEVICE(kid->child);
 361              if (d->channel == 0 && d->id == target) {
 362                 qdev_reset_all(&d->qdev);
 363              }
 364         }
 365         s->resetting--;
 366         break;
 367
 368     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 369     default:
 370         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 371         break;
 372     }
 373
 374     return ret;
 375
 376 incorrect_lun:
 377     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 378     return ret;
 379
 380 fail:
 381     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 382     return ret;
 383 }
 384
 385 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 386 {
 387     VirtIODevice *vdev = (VirtIODevice *)s;
 388     uint32_t type;
 389     int r = 0;
 390
 391     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 392                 &type, sizeof(type)) < sizeof(type)) {
 393         virtio_scsi_bad_req(req);
 394         return;
 395     }
 396
 397     virtio_tswap32s(vdev, &type);
 398     if (type == VIRTIO_SCSI_T_TMF) {
 399         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 400                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 401             virtio_scsi_bad_req(req);
 402             return;
 403         } else {
 404             r = virtio_scsi_do_tmf(s, req);
 405         }
 406
 407     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 408                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 409         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 410                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 411             virtio_scsi_bad_req(req);
 412             return;
 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 void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 426 {
 427     VirtIOSCSIReq *req;
 428
 429     while ((req = virtio_scsi_pop_req(s, vq))) {
 430         virtio_scsi_handle_ctrl_req(s, req);
 431     }
 432 }
 433
 434 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 435 {
 436     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 437
 438     if (s->ctx) {
 439         virtio_scsi_dataplane_start(s);
 440         if (!s->dataplane_fenced) {
 441             return;
 442         }
 443     }
 444     virtio_scsi_handle_ctrl_vq(s, vq);
 445 }
 446
 447 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 448 {
 449     /* Sense data is not in req->resp and is copied separately
 450      * in virtio_scsi_command_complete.
 451      */
 452     req->resp_size = sizeof(VirtIOSCSICmdResp);
 453     virtio_scsi_complete_req(req);
 454 }
 455
 456 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 457                                          size_t resid)
 458 {
 459     VirtIOSCSIReq *req = r->hba_private;
 460     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 461     uint32_t sense_len;
 462     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 463
 464     if (r->io_canceled) {
 465         return;
 466     }
 467
 468     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 469     req->resp.cmd.status = status;
 470     if (req->resp.cmd.status == GOOD) {
 471         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 472     } else {
 473         req->resp.cmd.resid = 0;
 474         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 475         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 476         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 477                             sense, sense_len);
 478         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 479     }
 480     virtio_scsi_complete_cmd_req(req);
 481 }
 482
 483 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 484                                  uint8_t *buf, void *hba_private)
 485 {
 486     VirtIOSCSIReq *req = hba_private;
 487
 488     if (cmd->len == 0) {
 489         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 490         memcpy(cmd->buf, buf, cmd->len);
 491     }
 492
 493     /* Extract the direction and mode directly from the request, for
 494      * host device passthrough.
 495      */
 496     cmd->xfer = req->qsgl.size;
 497     cmd->mode = req->mode;
 498     return 0;
 499 }
 500
 501 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 502 {
 503     VirtIOSCSIReq *req = r->hba_private;
 504
 505     return &req->qsgl;
 506 }
 507
 508 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 509 {
 510     VirtIOSCSIReq *req = r->hba_private;
 511
 512     if (!req) {
 513         return;
 514     }
 515     if (req->dev->resetting) {
 516         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 517     } else {
 518         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 519     }
 520     virtio_scsi_complete_cmd_req(req);
 521 }
 522
 523 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 524 {
 525     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 526     virtio_scsi_complete_cmd_req(req);
 527 }
 528
 529 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 530 {
 531     VirtIOSCSICommon *vs = &s->parent_obj;
 532     SCSIDevice *d;
 533     int rc;
 534
 535     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 536                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 537     if (rc < 0) {
 538         if (rc == -ENOTSUP) {
 539             virtio_scsi_fail_cmd_req(req);
 540             return -ENOTSUP;
 541         } else {
 542             virtio_scsi_bad_req(req);
 543             return -EINVAL;
 544         }
 545     }
 546
 547     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 548     if (!d) {
 549         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 550         virtio_scsi_complete_cmd_req(req);
 551         return -ENOENT;
 552     }
 553     virtio_scsi_ctx_check(s, d);
 554     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 555                              virtio_scsi_get_lun(req->req.cmd.lun),
 556                              req->req.cmd.cdb, req);
 557
 558     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 559         && (req->sreq->cmd.mode != req->mode ||
 560             req->sreq->cmd.xfer > req->qsgl.size)) {
 561         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 562         virtio_scsi_complete_cmd_req(req);
 563         return -ENOBUFS;
 564     }
 565     scsi_req_ref(req->sreq);
 566     blk_io_plug(d->conf.blk);
 567     return 0;
 568 }
 569
 570 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 571 {
 572     SCSIRequest *sreq = req->sreq;
 573     if (scsi_req_enqueue(sreq)) {
 574         scsi_req_continue(sreq);
 575     }
 576     blk_io_unplug(sreq->dev->conf.blk);
 577     scsi_req_unref(sreq);
 578 }
 579
 580 void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 581 {
 582     VirtIOSCSIReq *req, *next;
 583     int ret;
 584
 585     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 586
 587     while ((req = virtio_scsi_pop_req(s, vq))) {
 588         ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 589         if (!ret) {
 590             QTAILQ_INSERT_TAIL(&reqs, req, next);
 591         } else if (ret == -EINVAL) {
 592             /* The device is broken and shouldn't process any request */
 593             while (!QTAILQ_EMPTY(&reqs)) {
 594                 req = QTAILQ_FIRST(&reqs);
 595                 QTAILQ_REMOVE(&reqs, req, next);
 596                 blk_io_unplug(req->sreq->dev->conf.blk);
 597                 scsi_req_unref(req->sreq);
 598                 virtqueue_detach_element(req->vq, &req->elem, 0);
 599                 virtio_scsi_free_req(req);
 600             }
 601         }
 602     }
 603
 604     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 605         virtio_scsi_handle_cmd_req_submit(s, req);
 606     }
 607 }
 608
 609 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 610 {
 611     /* use non-QOM casts in the data path */
 612     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 613
 614     if (s->ctx) {
 615         virtio_scsi_dataplane_start(s);
 616         if (!s->dataplane_fenced) {
 617             return;
 618         }
 619     }
 620     virtio_scsi_handle_cmd_vq(s, vq);
 621 }
 622
 623 static void virtio_scsi_get_config(VirtIODevice *vdev,
 624                                    uint8_t *config)
 625 {
 626     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 627     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 628
 629     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 630     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 631     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 632     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 633     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 634     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 635     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 636     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 637     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 638     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 639 }
 640
 641 static void virtio_scsi_set_config(VirtIODevice *vdev,
 642                                    const uint8_t *config)
 643 {
 644     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 645     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 646
 647     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 648         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 649         virtio_error(vdev,
 650                      "bad data written to virtio-scsi configuration space");
 651         return;
 652     }
 653
 654     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 655     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 656 }
 657
 658 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 659                                          uint64_t requested_features,
 660                                          Error **errp)
 661 {
 662     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 663
 664     /* Firstly sync all virtio-scsi possible supported features */
 665     requested_features |= s->host_features;
 666     return requested_features;
 667 }
 668
 669 static void virtio_scsi_reset(VirtIODevice *vdev)
 670 {
 671     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 672     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 673
 674     if (s->ctx) {
 675         virtio_scsi_dataplane_stop(s);
 676     }
 677     s->resetting++;
 678     qbus_reset_all(&s->bus.qbus);
 679     s->resetting--;
 680
 681     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 682     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 683     s->events_dropped = false;
 684 }
 685
 686 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 687                             uint32_t event, uint32_t reason)
 688 {
 689     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 690     VirtIOSCSIReq *req;
 691     VirtIOSCSIEvent *evt;
 692     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 693
 694     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 695         return;
 696     }
 697
 698     if (s->dataplane_started) {
 699         assert(s->ctx);
 700         aio_context_acquire(s->ctx);
 701     }
 702
 703     req = virtio_scsi_pop_req(s, vs->event_vq);
 704     if (!req) {
 705         s->events_dropped = true;
 706         goto out;
 707     }
 708
 709     if (s->events_dropped) {
 710         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 711         s->events_dropped = false;
 712     }
 713
 714     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 715         virtio_scsi_bad_req(req);
 716         goto out;
 717     }
 718
 719     evt = &req->resp.event;
 720     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 721     evt->event = virtio_tswap32(vdev, event);
 722     evt->reason = virtio_tswap32(vdev, reason);
 723     if (!dev) {
 724         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 725     } else {
 726         evt->lun[0] = 1;
 727         evt->lun[1] = dev->id;
 728
 729         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 730         if (dev->lun >= 256) {
 731             evt->lun[2] = (dev->lun >> 8) | 0x40;
 732         }
 733         evt->lun[3] = dev->lun & 0xFF;
 734     }
 735     virtio_scsi_complete_req(req);
 736 out:
 737     if (s->dataplane_started) {
 738         aio_context_release(s->ctx);
 739     }
 740 }
 741
 742 void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 743 {
 744     if (s->events_dropped) {
 745         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 746     }
 747 }
 748
 749 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 750 {
 751     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 752
 753     if (s->ctx) {
 754         virtio_scsi_dataplane_start(s);
 755         if (!s->dataplane_fenced) {
 756             return;
 757         }
 758     }
 759     virtio_scsi_handle_event_vq(s, vq);
 760 }
 761
 762 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 763 {
 764     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 765     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 766
 767     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 768         dev->type != TYPE_ROM) {
 769         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 770                                sense.asc | (sense.ascq << 8));
 771     }
 772 }
 773
 774 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 775                                 Error **errp)
 776 {
 777     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 778     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 779     SCSIDevice *sd = SCSI_DEVICE(dev);
 780
 781     if (s->ctx && !s->dataplane_fenced) {
 782         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 783             return;
 784         }
 785         aio_context_acquire(s->ctx);
 786         blk_set_aio_context(sd->conf.blk, s->ctx);
 787         aio_context_release(s->ctx);
 788
 789     }
 790
 791     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 792         virtio_scsi_push_event(s, sd,
 793                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 794                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 795     }
 796 }
 797
 798 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 799                                   Error **errp)
 800 {
 801     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 802     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 803     SCSIDevice *sd = SCSI_DEVICE(dev);
 804
 805     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 806         virtio_scsi_push_event(s, sd,
 807                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 808                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 809     }
 810
 811     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 812 }
 813
 814 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 815     .tcq = true,
 816     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 817     .max_target = VIRTIO_SCSI_MAX_TARGET,
 818     .max_lun = VIRTIO_SCSI_MAX_LUN,
 819
 820     .complete = virtio_scsi_command_complete,
 821     .cancel = virtio_scsi_request_cancelled,
 822     .change = virtio_scsi_change,
 823     .parse_cdb = virtio_scsi_parse_cdb,
 824     .get_sg_list = virtio_scsi_get_sg_list,
 825     .save_request = virtio_scsi_save_request,
 826     .load_request = virtio_scsi_load_request,
 827 };
 828
 829 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 830                                 VirtIOHandleOutput ctrl,
 831                                 VirtIOHandleOutput evt,
 832                                 VirtIOHandleOutput cmd)
 833 {
 834     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 835     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 836     int i;
 837
 838     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 839                 sizeof(VirtIOSCSIConfig));
 840
 841     if (s->conf.num_queues == 0 ||
 842             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 843         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 844                          "must be a positive integer less than %d.",
 845                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 846         virtio_cleanup(vdev);
 847         return;
 848     }
 849     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 850     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 851     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 852
 853     s->ctrl_vq = virtio_add_queue_aio(vdev, VIRTIO_SCSI_VQ_SIZE, ctrl);
 854     s->event_vq = virtio_add_queue_aio(vdev, VIRTIO_SCSI_VQ_SIZE, evt);
 855     for (i = 0; i < s->conf.num_queues; i++) {
 856         s->cmd_vqs[i] = virtio_add_queue_aio(vdev, VIRTIO_SCSI_VQ_SIZE, cmd);
 857     }
 858
 859     if (s->conf.iothread) {
 860         virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
 861     }
 862 }
 863
 864 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 865 {
 866     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 867     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 868     Error *err = NULL;
 869
 870     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 871                                virtio_scsi_handle_event,
 872                                virtio_scsi_handle_cmd);
 873     if (err != NULL) {
 874         error_propagate(errp, err);
 875         return;
 876     }
 877
 878     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 879                  &virtio_scsi_scsi_info, vdev->bus_name);
 880     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 881     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 882
 883     if (!dev->hotplugged) {
 884         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 885         if (err != NULL) {
 886             error_propagate(errp, err);
 887             return;
 888         }
 889     }
 890 }
 891
 892 static void virtio_scsi_instance_init(Object *obj)
 893 {
 894     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 895
 896     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 897                              (Object **)&vs->conf.iothread,
 898                              qdev_prop_allow_set_link_before_realize,
 899                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 900 }
 901
 902 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 903 {
 904     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 905     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 906
 907     g_free(vs->cmd_vqs);
 908     virtio_cleanup(vdev);
 909 }
 910
 911 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 912 {
 913     virtio_scsi_common_unrealize(dev, errp);
 914 }
 915
 916 static Property virtio_scsi_properties[] = {
 917     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 918     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 919                                                   0xFFFF),
 920     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 921                                                   128),
 922     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 923                                            VIRTIO_SCSI_F_HOTPLUG, true),
 924     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 925                                                 VIRTIO_SCSI_F_CHANGE, true),
 926     DEFINE_PROP_END_OF_LIST(),
 927 };
 928
 929 static const VMStateDescription vmstate_virtio_scsi = {
 930     .name = "virtio-scsi",
 931     .minimum_version_id = 1,
 932     .version_id = 1,
 933     .fields = (VMStateField[]) {
 934         VMSTATE_VIRTIO_DEVICE,
 935         VMSTATE_END_OF_LIST()
 936     },
 937 };
 938
 939 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 940 {
 941     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 942     DeviceClass *dc = DEVICE_CLASS(klass);
 943
 944     vdc->get_config = virtio_scsi_get_config;
 945     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 946 }
 947
 948 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 949 {
 950     DeviceClass *dc = DEVICE_CLASS(klass);
 951     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 952     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 953
 954     dc->props = virtio_scsi_properties;
 955     dc->vmsd = &vmstate_virtio_scsi;
 956     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 957     vdc->realize = virtio_scsi_device_realize;
 958     vdc->unrealize = virtio_scsi_device_unrealize;
 959     vdc->set_config = virtio_scsi_set_config;
 960     vdc->get_features = virtio_scsi_get_features;
 961     vdc->reset = virtio_scsi_reset;
 962     hc->plug = virtio_scsi_hotplug;
 963     hc->unplug = virtio_scsi_hotunplug;
 964 }
 965
 966 static const TypeInfo virtio_scsi_common_info = {
 967     .name = TYPE_VIRTIO_SCSI_COMMON,
 968     .parent = TYPE_VIRTIO_DEVICE,
 969     .instance_size = sizeof(VirtIOSCSICommon),
 970     .abstract = true,
 971     .class_init = virtio_scsi_common_class_init,
 972 };
 973
 974 static const TypeInfo virtio_scsi_info = {
 975     .name = TYPE_VIRTIO_SCSI,
 976     .parent = TYPE_VIRTIO_SCSI_COMMON,
 977     .instance_size = sizeof(VirtIOSCSI),
 978     .instance_init = virtio_scsi_instance_init,
 979     .class_init = virtio_scsi_class_init,
 980     .interfaces = (InterfaceInfo[]) {
 981         { TYPE_HOTPLUG_HANDLER },
 982         { }
 983     }
 984 };
 985
 986 static void virtio_register_types(void)
 987 {
 988     type_register_static(&virtio_scsi_common_info);
 989     type_register_static(&virtio_scsi_info);
 990 }
 991
 992 type_init(virtio_register_types)