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     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 202     VirtIOSCSIReq *req;
 203     uint32_t n;
 204
 205     qemu_get_be32s(f, &n);
 206     assert(n < vs->conf.num_queues);
 207     req = qemu_get_virtqueue_element(vdev, f,
 208                                      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 static inline void virtio_scsi_acquire(VirtIOSCSI *s)
 426 {
 427     if (s->ctx) {
 428         aio_context_acquire(s->ctx);
 429     }
 430 }
 431
 432 static inline void virtio_scsi_release(VirtIOSCSI *s)
 433 {
 434     if (s->ctx) {
 435         aio_context_release(s->ctx);
 436     }
 437 }
 438
 439 bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 440 {
 441     VirtIOSCSIReq *req;
 442     bool progress = false;
 443
 444     virtio_scsi_acquire(s);
 445     while ((req = virtio_scsi_pop_req(s, vq))) {
 446         progress = true;
 447         virtio_scsi_handle_ctrl_req(s, req);
 448     }
 449     virtio_scsi_release(s);
 450     return progress;
 451 }
 452
 453 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 454 {
 455     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 456
 457     if (s->ctx) {
 458         virtio_device_start_ioeventfd(vdev);
 459         if (!s->dataplane_fenced) {
 460             return;
 461         }
 462     }
 463     virtio_scsi_handle_ctrl_vq(s, vq);
 464 }
 465
 466 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 467 {
 468     /* Sense data is not in req->resp and is copied separately
 469      * in virtio_scsi_command_complete.
 470      */
 471     req->resp_size = sizeof(VirtIOSCSICmdResp);
 472     virtio_scsi_complete_req(req);
 473 }
 474
 475 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 476                                          size_t resid)
 477 {
 478     VirtIOSCSIReq *req = r->hba_private;
 479     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 480     uint32_t sense_len;
 481     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 482
 483     if (r->io_canceled) {
 484         return;
 485     }
 486
 487     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 488     req->resp.cmd.status = status;
 489     if (req->resp.cmd.status == GOOD) {
 490         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 491     } else {
 492         req->resp.cmd.resid = 0;
 493         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 494         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 495         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 496                             sense, sense_len);
 497         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 498     }
 499     virtio_scsi_complete_cmd_req(req);
 500 }
 501
 502 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 503                                  uint8_t *buf, void *hba_private)
 504 {
 505     VirtIOSCSIReq *req = hba_private;
 506
 507     if (cmd->len == 0) {
 508         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 509         memcpy(cmd->buf, buf, cmd->len);
 510     }
 511
 512     /* Extract the direction and mode directly from the request, for
 513      * host device passthrough.
 514      */
 515     cmd->xfer = req->qsgl.size;
 516     cmd->mode = req->mode;
 517     return 0;
 518 }
 519
 520 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 521 {
 522     VirtIOSCSIReq *req = r->hba_private;
 523
 524     return &req->qsgl;
 525 }
 526
 527 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 528 {
 529     VirtIOSCSIReq *req = r->hba_private;
 530
 531     if (!req) {
 532         return;
 533     }
 534     if (req->dev->resetting) {
 535         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 536     } else {
 537         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 538     }
 539     virtio_scsi_complete_cmd_req(req);
 540 }
 541
 542 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 543 {
 544     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 545     virtio_scsi_complete_cmd_req(req);
 546 }
 547
 548 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 549 {
 550     VirtIOSCSICommon *vs = &s->parent_obj;
 551     SCSIDevice *d;
 552     int rc;
 553
 554     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 555                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 556     if (rc < 0) {
 557         if (rc == -ENOTSUP) {
 558             virtio_scsi_fail_cmd_req(req);
 559             return -ENOTSUP;
 560         } else {
 561             virtio_scsi_bad_req(req);
 562             return -EINVAL;
 563         }
 564     }
 565
 566     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 567     if (!d) {
 568         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 569         virtio_scsi_complete_cmd_req(req);
 570         return -ENOENT;
 571     }
 572     virtio_scsi_ctx_check(s, d);
 573     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 574                              virtio_scsi_get_lun(req->req.cmd.lun),
 575                              req->req.cmd.cdb, req);
 576
 577     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 578         && (req->sreq->cmd.mode != req->mode ||
 579             req->sreq->cmd.xfer > req->qsgl.size)) {
 580         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 581         virtio_scsi_complete_cmd_req(req);
 582         return -ENOBUFS;
 583     }
 584     scsi_req_ref(req->sreq);
 585     blk_io_plug(d->conf.blk);
 586     return 0;
 587 }
 588
 589 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 590 {
 591     SCSIRequest *sreq = req->sreq;
 592     if (scsi_req_enqueue(sreq)) {
 593         scsi_req_continue(sreq);
 594     }
 595     blk_io_unplug(sreq->dev->conf.blk);
 596     scsi_req_unref(sreq);
 597 }
 598
 599 bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 600 {
 601     VirtIOSCSIReq *req, *next;
 602     int ret = 0;
 603     bool progress = false;
 604
 605     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 606
 607     virtio_scsi_acquire(s);
 608     do {
 609         virtio_queue_set_notification(vq, 0);
 610
 611         while ((req = virtio_scsi_pop_req(s, vq))) {
 612             progress = true;
 613             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 614             if (!ret) {
 615                 QTAILQ_INSERT_TAIL(&reqs, req, next);
 616             } else if (ret == -EINVAL) {
 617                 /* The device is broken and shouldn't process any request */
 618                 while (!QTAILQ_EMPTY(&reqs)) {
 619                     req = QTAILQ_FIRST(&reqs);
 620                     QTAILQ_REMOVE(&reqs, req, next);
 621                     blk_io_unplug(req->sreq->dev->conf.blk);
 622                     scsi_req_unref(req->sreq);
 623                     virtqueue_detach_element(req->vq, &req->elem, 0);
 624                     virtio_scsi_free_req(req);
 625                 }
 626             }
 627         }
 628
 629         virtio_queue_set_notification(vq, 1);
 630     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 631
 632     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 633         virtio_scsi_handle_cmd_req_submit(s, req);
 634     }
 635     virtio_scsi_release(s);
 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_handle_cmd_vq(s, vq);
 651 }
 652
 653 static void virtio_scsi_get_config(VirtIODevice *vdev,
 654                                    uint8_t *config)
 655 {
 656     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 657     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 658
 659     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 660     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 661     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 662     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 663     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 664     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 665     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 666     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 667     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 668     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 669 }
 670
 671 static void virtio_scsi_set_config(VirtIODevice *vdev,
 672                                    const uint8_t *config)
 673 {
 674     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 675     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 676
 677     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 678         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 679         virtio_error(vdev,
 680                      "bad data written to virtio-scsi configuration space");
 681         return;
 682     }
 683
 684     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 685     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 686 }
 687
 688 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 689                                          uint64_t requested_features,
 690                                          Error **errp)
 691 {
 692     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 693
 694     /* Firstly sync all virtio-scsi possible supported features */
 695     requested_features |= s->host_features;
 696     return requested_features;
 697 }
 698
 699 static void virtio_scsi_reset(VirtIODevice *vdev)
 700 {
 701     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 702     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 703
 704     assert(!s->dataplane_started);
 705     s->resetting++;
 706     qbus_reset_all(&s->bus.qbus);
 707     s->resetting--;
 708
 709     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 710     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 711     s->events_dropped = false;
 712 }
 713
 714 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 715                             uint32_t event, uint32_t reason)
 716 {
 717     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 718     VirtIOSCSIReq *req;
 719     VirtIOSCSIEvent *evt;
 720     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 721
 722     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 723         return;
 724     }
 725
 726     virtio_scsi_acquire(s);
 727
 728     req = virtio_scsi_pop_req(s, vs->event_vq);
 729     if (!req) {
 730         s->events_dropped = true;
 731         goto out;
 732     }
 733
 734     if (s->events_dropped) {
 735         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 736         s->events_dropped = false;
 737     }
 738
 739     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 740         virtio_scsi_bad_req(req);
 741         goto out;
 742     }
 743
 744     evt = &req->resp.event;
 745     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 746     evt->event = virtio_tswap32(vdev, event);
 747     evt->reason = virtio_tswap32(vdev, reason);
 748     if (!dev) {
 749         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 750     } else {
 751         evt->lun[0] = 1;
 752         evt->lun[1] = dev->id;
 753
 754         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 755         if (dev->lun >= 256) {
 756             evt->lun[2] = (dev->lun >> 8) | 0x40;
 757         }
 758         evt->lun[3] = dev->lun & 0xFF;
 759     }
 760     virtio_scsi_complete_req(req);
 761 out:
 762     virtio_scsi_release(s);
 763 }
 764
 765 bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 766 {
 767     virtio_scsi_acquire(s);
 768     if (s->events_dropped) {
 769         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 770         virtio_scsi_release(s);
 771         return true;
 772     }
 773     virtio_scsi_release(s);
 774     return false;
 775 }
 776
 777 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 778 {
 779     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 780
 781     if (s->ctx) {
 782         virtio_device_start_ioeventfd(vdev);
 783         if (!s->dataplane_fenced) {
 784             return;
 785         }
 786     }
 787     virtio_scsi_handle_event_vq(s, vq);
 788 }
 789
 790 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 791 {
 792     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 793     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 794
 795     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 796         dev->type != TYPE_ROM) {
 797         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 798                                sense.asc | (sense.ascq << 8));
 799     }
 800 }
 801
 802 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 803                                 Error **errp)
 804 {
 805     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 806     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 807     SCSIDevice *sd = SCSI_DEVICE(dev);
 808
 809     if (s->ctx && !s->dataplane_fenced) {
 810         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 811             return;
 812         }
 813         virtio_scsi_acquire(s);
 814         blk_set_aio_context(sd->conf.blk, s->ctx);
 815         virtio_scsi_release(s);
 816
 817     }
 818
 819     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 820         virtio_scsi_push_event(s, sd,
 821                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 822                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 823     }
 824 }
 825
 826 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 827                                   Error **errp)
 828 {
 829     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 830     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 831     SCSIDevice *sd = SCSI_DEVICE(dev);
 832
 833     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 834         virtio_scsi_push_event(s, sd,
 835                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 836                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 837     }
 838
 839     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 840 }
 841
 842 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 843     .tcq = true,
 844     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 845     .max_target = VIRTIO_SCSI_MAX_TARGET,
 846     .max_lun = VIRTIO_SCSI_MAX_LUN,
 847
 848     .complete = virtio_scsi_command_complete,
 849     .cancel = virtio_scsi_request_cancelled,
 850     .change = virtio_scsi_change,
 851     .parse_cdb = virtio_scsi_parse_cdb,
 852     .get_sg_list = virtio_scsi_get_sg_list,
 853     .save_request = virtio_scsi_save_request,
 854     .load_request = virtio_scsi_load_request,
 855 };
 856
 857 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 858                                 VirtIOHandleOutput ctrl,
 859                                 VirtIOHandleOutput evt,
 860                                 VirtIOHandleOutput cmd)
 861 {
 862     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 863     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 864     int i;
 865
 866     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 867                 sizeof(VirtIOSCSIConfig));
 868
 869     if (s->conf.num_queues == 0 ||
 870             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 871         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 872                          "must be a positive integer less than %d.",
 873                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 874         virtio_cleanup(vdev);
 875         return;
 876     }
 877     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 878     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 879     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 880
 881     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE, ctrl);
 882     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE, evt);
 883     for (i = 0; i < s->conf.num_queues; i++) {
 884         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE, cmd);
 885     }
 886 }
 887
 888 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 889 {
 890     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 891     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 892     Error *err = NULL;
 893
 894     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 895                                virtio_scsi_handle_event,
 896                                virtio_scsi_handle_cmd);
 897     if (err != NULL) {
 898         error_propagate(errp, err);
 899         return;
 900     }
 901
 902     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 903                  &virtio_scsi_scsi_info, vdev->bus_name);
 904     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 905     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 906
 907     virtio_scsi_dataplane_setup(s, errp);
 908 }
 909
 910 static void virtio_scsi_instance_init(Object *obj)
 911 {
 912     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 913
 914     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 915                              (Object **)&vs->conf.iothread,
 916                              qdev_prop_allow_set_link_before_realize,
 917                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 918 }
 919
 920 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 921 {
 922     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 923     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 924
 925     g_free(vs->cmd_vqs);
 926     virtio_cleanup(vdev);
 927 }
 928
 929 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 930 {
 931     virtio_scsi_common_unrealize(dev, errp);
 932 }
 933
 934 static Property virtio_scsi_properties[] = {
 935     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 936     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 937                                                   0xFFFF),
 938     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 939                                                   128),
 940     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 941                                            VIRTIO_SCSI_F_HOTPLUG, true),
 942     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 943                                                 VIRTIO_SCSI_F_CHANGE, true),
 944     DEFINE_PROP_END_OF_LIST(),
 945 };
 946
 947 static const VMStateDescription vmstate_virtio_scsi = {
 948     .name = "virtio-scsi",
 949     .minimum_version_id = 1,
 950     .version_id = 1,
 951     .fields = (VMStateField[]) {
 952         VMSTATE_VIRTIO_DEVICE,
 953         VMSTATE_END_OF_LIST()
 954     },
 955 };
 956
 957 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 958 {
 959     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 960     DeviceClass *dc = DEVICE_CLASS(klass);
 961
 962     vdc->get_config = virtio_scsi_get_config;
 963     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 964 }
 965
 966 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 967 {
 968     DeviceClass *dc = DEVICE_CLASS(klass);
 969     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 970     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 971
 972     dc->props = virtio_scsi_properties;
 973     dc->vmsd = &vmstate_virtio_scsi;
 974     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 975     vdc->realize = virtio_scsi_device_realize;
 976     vdc->unrealize = virtio_scsi_device_unrealize;
 977     vdc->set_config = virtio_scsi_set_config;
 978     vdc->get_features = virtio_scsi_get_features;
 979     vdc->reset = virtio_scsi_reset;
 980     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
 981     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
 982     hc->plug = virtio_scsi_hotplug;
 983     hc->unplug = virtio_scsi_hotunplug;
 984 }
 985
 986 static const TypeInfo virtio_scsi_common_info = {
 987     .name = TYPE_VIRTIO_SCSI_COMMON,
 988     .parent = TYPE_VIRTIO_DEVICE,
 989     .instance_size = sizeof(VirtIOSCSICommon),
 990     .abstract = true,
 991     .class_init = virtio_scsi_common_class_init,
 992 };
 993
 994 static const TypeInfo virtio_scsi_info = {
 995     .name = TYPE_VIRTIO_SCSI,
 996     .parent = TYPE_VIRTIO_SCSI_COMMON,
 997     .instance_size = sizeof(VirtIOSCSI),
 998     .instance_init = virtio_scsi_instance_init,
 999     .class_init = virtio_scsi_class_init,
1000     .interfaces = (InterfaceInfo[]) {
1001         { TYPE_HOTPLUG_HANDLER },
1002         { }
1003     }
1004 };
1005
1006 static void virtio_register_types(void)
1007 {
1008     type_register_static(&virtio_scsi_common_info);
1009     type_register_static(&virtio_scsi_info);
1010 }
1011
1012 type_init(virtio_register_types)