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_get(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_get(&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) - VIRTIO_SCSI_VQ_NUM_FIXED;
 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_get(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
 371         rcu_read_lock();
 372         QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
 373             SCSIDevice *d1 = SCSI_DEVICE(kid->child);
 374             if (d1->channel == 0 && d1->id == target) {
 375                 qdev_reset_all(&d1->qdev);
 376             }
 377         }
 378         rcu_read_unlock();
 379
 380         s->resetting--;
 381         break;
 382
 383     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 384     default:
 385         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 386         break;
 387     }
 388
 389     object_unref(OBJECT(d));
 390     return ret;
 391
 392 incorrect_lun:
 393     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 394     object_unref(OBJECT(d));
 395     return ret;
 396
 397 fail:
 398     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 399     object_unref(OBJECT(d));
 400     return ret;
 401 }
 402
 403 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 404 {
 405     VirtIODevice *vdev = (VirtIODevice *)s;
 406     uint32_t type;
 407     int r = 0;
 408
 409     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 410                 &type, sizeof(type)) < sizeof(type)) {
 411         virtio_scsi_bad_req(req);
 412         return;
 413     }
 414
 415     virtio_tswap32s(vdev, &type);
 416     if (type == VIRTIO_SCSI_T_TMF) {
 417         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 418                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 419             virtio_scsi_bad_req(req);
 420             return;
 421         } else {
 422             r = virtio_scsi_do_tmf(s, req);
 423         }
 424
 425     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 426                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 427         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 428                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 429             virtio_scsi_bad_req(req);
 430             return;
 431         } else {
 432             req->resp.an.event_actual = 0;
 433             req->resp.an.response = VIRTIO_SCSI_S_OK;
 434         }
 435     }
 436     if (r == 0) {
 437         virtio_scsi_complete_req(req);
 438     } else {
 439         assert(r == -EINPROGRESS);
 440     }
 441 }
 442
 443 bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 444 {
 445     VirtIOSCSIReq *req;
 446     bool progress = false;
 447
 448     while ((req = virtio_scsi_pop_req(s, vq))) {
 449         progress = true;
 450         virtio_scsi_handle_ctrl_req(s, req);
 451     }
 452     return progress;
 453 }
 454
 455 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 456 {
 457     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 458
 459     if (s->ctx) {
 460         virtio_device_start_ioeventfd(vdev);
 461         if (!s->dataplane_fenced) {
 462             return;
 463         }
 464     }
 465     virtio_scsi_acquire(s);
 466     virtio_scsi_handle_ctrl_vq(s, vq);
 467     virtio_scsi_release(s);
 468 }
 469
 470 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 471 {
 472     /* Sense data is not in req->resp and is copied separately
 473      * in virtio_scsi_command_complete.
 474      */
 475     req->resp_size = sizeof(VirtIOSCSICmdResp);
 476     virtio_scsi_complete_req(req);
 477 }
 478
 479 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 480                                          size_t resid)
 481 {
 482     VirtIOSCSIReq *req = r->hba_private;
 483     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 484     uint32_t sense_len;
 485     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 486
 487     if (r->io_canceled) {
 488         return;
 489     }
 490
 491     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 492     req->resp.cmd.status = status;
 493     if (req->resp.cmd.status == GOOD) {
 494         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 495     } else {
 496         req->resp.cmd.resid = 0;
 497         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 498         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 499         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 500                             sense, sense_len);
 501         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 502     }
 503     virtio_scsi_complete_cmd_req(req);
 504 }
 505
 506 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 507                                  uint8_t *buf, void *hba_private)
 508 {
 509     VirtIOSCSIReq *req = hba_private;
 510
 511     if (cmd->len == 0) {
 512         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 513         memcpy(cmd->buf, buf, cmd->len);
 514     }
 515
 516     /* Extract the direction and mode directly from the request, for
 517      * host device passthrough.
 518      */
 519     cmd->xfer = req->qsgl.size;
 520     cmd->mode = req->mode;
 521     return 0;
 522 }
 523
 524 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 525 {
 526     VirtIOSCSIReq *req = r->hba_private;
 527
 528     return &req->qsgl;
 529 }
 530
 531 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 532 {
 533     VirtIOSCSIReq *req = r->hba_private;
 534
 535     if (!req) {
 536         return;
 537     }
 538     if (req->dev->resetting) {
 539         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 540     } else {
 541         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 542     }
 543     virtio_scsi_complete_cmd_req(req);
 544 }
 545
 546 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 547 {
 548     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 549     virtio_scsi_complete_cmd_req(req);
 550 }
 551
 552 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 553 {
 554     VirtIOSCSICommon *vs = &s->parent_obj;
 555     SCSIDevice *d;
 556     int rc;
 557
 558     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 559                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 560     if (rc < 0) {
 561         if (rc == -ENOTSUP) {
 562             virtio_scsi_fail_cmd_req(req);
 563             return -ENOTSUP;
 564         } else {
 565             virtio_scsi_bad_req(req);
 566             return -EINVAL;
 567         }
 568     }
 569
 570     d = virtio_scsi_device_get(s, req->req.cmd.lun);
 571     if (!d) {
 572         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 573         virtio_scsi_complete_cmd_req(req);
 574         return -ENOENT;
 575     }
 576     virtio_scsi_ctx_check(s, d);
 577     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 578                              virtio_scsi_get_lun(req->req.cmd.lun),
 579                              req->req.cmd.cdb, req);
 580
 581     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 582         && (req->sreq->cmd.mode != req->mode ||
 583             req->sreq->cmd.xfer > req->qsgl.size)) {
 584         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 585         virtio_scsi_complete_cmd_req(req);
 586         object_unref(OBJECT(d));
 587         return -ENOBUFS;
 588     }
 589     scsi_req_ref(req->sreq);
 590     blk_io_plug(d->conf.blk);
 591     object_unref(OBJECT(d));
 592     return 0;
 593 }
 594
 595 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 596 {
 597     SCSIRequest *sreq = req->sreq;
 598     if (scsi_req_enqueue(sreq)) {
 599         scsi_req_continue(sreq);
 600     }
 601     blk_io_unplug(sreq->dev->conf.blk);
 602     scsi_req_unref(sreq);
 603 }
 604
 605 bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 606 {
 607     VirtIOSCSIReq *req, *next;
 608     int ret = 0;
 609     bool suppress_notifications = virtio_queue_get_notification(vq);
 610     bool progress = false;
 611
 612     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 613
 614     do {
 615         if (suppress_notifications) {
 616             virtio_queue_set_notification(vq, 0);
 617         }
 618
 619         while ((req = virtio_scsi_pop_req(s, vq))) {
 620             progress = true;
 621             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 622             if (!ret) {
 623                 QTAILQ_INSERT_TAIL(&reqs, req, next);
 624             } else if (ret == -EINVAL) {
 625                 /* The device is broken and shouldn't process any request */
 626                 while (!QTAILQ_EMPTY(&reqs)) {
 627                     req = QTAILQ_FIRST(&reqs);
 628                     QTAILQ_REMOVE(&reqs, req, next);
 629                     blk_io_unplug(req->sreq->dev->conf.blk);
 630                     scsi_req_unref(req->sreq);
 631                     virtqueue_detach_element(req->vq, &req->elem, 0);
 632                     virtio_scsi_free_req(req);
 633                 }
 634             }
 635         }
 636
 637         if (suppress_notifications) {
 638             virtio_queue_set_notification(vq, 1);
 639         }
 640     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 641
 642     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 643         virtio_scsi_handle_cmd_req_submit(s, req);
 644     }
 645     return progress;
 646 }
 647
 648 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 649 {
 650     /* use non-QOM casts in the data path */
 651     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 652
 653     if (s->ctx) {
 654         virtio_device_start_ioeventfd(vdev);
 655         if (!s->dataplane_fenced) {
 656             return;
 657         }
 658     }
 659     virtio_scsi_acquire(s);
 660     virtio_scsi_handle_cmd_vq(s, vq);
 661     virtio_scsi_release(s);
 662 }
 663
 664 static void virtio_scsi_get_config(VirtIODevice *vdev,
 665                                    uint8_t *config)
 666 {
 667     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 668     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 669
 670     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 671     virtio_stl_p(vdev, &scsiconf->seg_max,
 672                  s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
 673     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 674     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 675     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 676     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 677     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 678     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 679     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 680     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 681 }
 682
 683 static void virtio_scsi_set_config(VirtIODevice *vdev,
 684                                    const uint8_t *config)
 685 {
 686     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 687     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 688
 689     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 690         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 691         virtio_error(vdev,
 692                      "bad data written to virtio-scsi configuration space");
 693         return;
 694     }
 695
 696     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 697     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 698 }
 699
 700 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 701                                          uint64_t requested_features,
 702                                          Error **errp)
 703 {
 704     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 705
 706     /* Firstly sync all virtio-scsi possible supported features */
 707     requested_features |= s->host_features;
 708     return requested_features;
 709 }
 710
 711 static void virtio_scsi_reset(VirtIODevice *vdev)
 712 {
 713     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 714     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 715
 716     assert(!s->dataplane_started);
 717     s->resetting++;
 718     qbus_reset_all(BUS(&s->bus));
 719     s->resetting--;
 720
 721     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 722     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 723     s->events_dropped = false;
 724 }
 725
 726 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 727                             uint32_t event, uint32_t reason)
 728 {
 729     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 730     VirtIOSCSIReq *req;
 731     VirtIOSCSIEvent *evt;
 732     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 733
 734     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 735         return;
 736     }
 737
 738     req = virtio_scsi_pop_req(s, vs->event_vq);
 739     if (!req) {
 740         s->events_dropped = true;
 741         return;
 742     }
 743
 744     if (s->events_dropped) {
 745         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 746         s->events_dropped = false;
 747     }
 748
 749     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 750         virtio_scsi_bad_req(req);
 751         return;
 752     }
 753
 754     evt = &req->resp.event;
 755     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 756     evt->event = virtio_tswap32(vdev, event);
 757     evt->reason = virtio_tswap32(vdev, reason);
 758     if (!dev) {
 759         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 760     } else {
 761         evt->lun[0] = 1;
 762         evt->lun[1] = dev->id;
 763
 764         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 765         if (dev->lun >= 256) {
 766             evt->lun[2] = (dev->lun >> 8) | 0x40;
 767         }
 768         evt->lun[3] = dev->lun & 0xFF;
 769     }
 770     virtio_scsi_complete_req(req);
 771 }
 772
 773 bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 774 {
 775     if (s->events_dropped) {
 776         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 777         return true;
 778     }
 779     return false;
 780 }
 781
 782 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 783 {
 784     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 785
 786     if (s->ctx) {
 787         virtio_device_start_ioeventfd(vdev);
 788         if (!s->dataplane_fenced) {
 789             return;
 790         }
 791     }
 792     virtio_scsi_acquire(s);
 793     virtio_scsi_handle_event_vq(s, vq);
 794     virtio_scsi_release(s);
 795 }
 796
 797 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 798 {
 799     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 800     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 801
 802     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 803         dev->type != TYPE_ROM) {
 804         virtio_scsi_acquire(s);
 805         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 806                                sense.asc | (sense.ascq << 8));
 807         virtio_scsi_release(s);
 808     }
 809 }
 810
 811 static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
 812                                     DeviceState *dev, Error **errp)
 813 {
 814     SCSIDevice *sd = SCSI_DEVICE(dev);
 815     sd->hba_supports_iothread = true;
 816 }
 817
 818 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 819                                 Error **errp)
 820 {
 821     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 822     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 823     SCSIDevice *sd = SCSI_DEVICE(dev);
 824     int ret;
 825
 826     if (s->ctx && !s->dataplane_fenced) {
 827         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 828             return;
 829         }
 830         virtio_scsi_acquire(s);
 831         ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
 832         virtio_scsi_release(s);
 833         if (ret < 0) {
 834             return;
 835         }
 836     }
 837
 838     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 839         virtio_scsi_acquire(s);
 840         virtio_scsi_push_event(s, sd,
 841                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 842                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 843         virtio_scsi_release(s);
 844     }
 845 }
 846
 847 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 848                                   Error **errp)
 849 {
 850     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 851     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 852     SCSIDevice *sd = SCSI_DEVICE(dev);
 853     AioContext *ctx = s->ctx ?: qemu_get_aio_context();
 854
 855     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 856         virtio_scsi_acquire(s);
 857         virtio_scsi_push_event(s, sd,
 858                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 859                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 860         virtio_scsi_release(s);
 861     }
 862
 863     aio_disable_external(ctx);
 864     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 865     aio_enable_external(ctx);
 866
 867     if (s->ctx) {
 868         virtio_scsi_acquire(s);
 869         /* If other users keep the BlockBackend in the iothread, that's ok */
 870         blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
 871         virtio_scsi_release(s);
 872     }
 873 }
 874
 875 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 876     .tcq = true,
 877     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 878     .max_target = VIRTIO_SCSI_MAX_TARGET,
 879     .max_lun = VIRTIO_SCSI_MAX_LUN,
 880
 881     .complete = virtio_scsi_command_complete,
 882     .cancel = virtio_scsi_request_cancelled,
 883     .change = virtio_scsi_change,
 884     .parse_cdb = virtio_scsi_parse_cdb,
 885     .get_sg_list = virtio_scsi_get_sg_list,
 886     .save_request = virtio_scsi_save_request,
 887     .load_request = virtio_scsi_load_request,
 888 };
 889
 890 void virtio_scsi_common_realize(DeviceState *dev,
 891                                 VirtIOHandleOutput ctrl,
 892                                 VirtIOHandleOutput evt,
 893                                 VirtIOHandleOutput cmd,
 894                                 Error **errp)
 895 {
 896     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 897     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 898     int i;
 899
 900     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 901                 sizeof(VirtIOSCSIConfig));
 902
 903     if (s->conf.num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
 904         s->conf.num_queues = 1;
 905     }
 906     if (s->conf.num_queues == 0 ||
 907             s->conf.num_queues > VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED) {
 908         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 909                          "must be a positive integer less than %d.",
 910                    s->conf.num_queues,
 911                    VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED);
 912         virtio_cleanup(vdev);
 913         return;
 914     }
 915     if (s->conf.virtqueue_size <= 2) {
 916         error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
 917                    "must be > 2", s->conf.virtqueue_size);
 918         return;
 919     }
 920     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 921     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 922     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 923
 924     s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
 925     s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
 926     for (i = 0; i < s->conf.num_queues; i++) {
 927         s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
 928     }
 929 }
 930
 931 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 932 {
 933     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 934     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 935     Error *err = NULL;
 936
 937     virtio_scsi_common_realize(dev,
 938                                virtio_scsi_handle_ctrl,
 939                                virtio_scsi_handle_event,
 940                                virtio_scsi_handle_cmd,
 941                                &err);
 942     if (err != NULL) {
 943         error_propagate(errp, err);
 944         return;
 945     }
 946
 947     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 948                  &virtio_scsi_scsi_info, vdev->bus_name);
 949     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 950     qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev));
 951
 952     virtio_scsi_dataplane_setup(s, errp);
 953 }
 954
 955 void virtio_scsi_common_unrealize(DeviceState *dev)
 956 {
 957     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 958     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 959     int i;
 960
 961     virtio_delete_queue(vs->ctrl_vq);
 962     virtio_delete_queue(vs->event_vq);
 963     for (i = 0; i < vs->conf.num_queues; i++) {
 964         virtio_delete_queue(vs->cmd_vqs[i]);
 965     }
 966     g_free(vs->cmd_vqs);
 967     virtio_cleanup(vdev);
 968 }
 969
 970 static void virtio_scsi_device_unrealize(DeviceState *dev)
 971 {
 972     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 973
 974     qbus_set_hotplug_handler(BUS(&s->bus), NULL);
 975     virtio_scsi_common_unrealize(dev);
 976 }
 977
 978 static Property virtio_scsi_properties[] = {
 979     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues,
 980                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
 981     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
 982                                          parent_obj.conf.virtqueue_size, 256),
 983     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
 984                       parent_obj.conf.seg_max_adjust, true),
 985     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 986                                                   0xFFFF),
 987     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 988                                                   128),
 989     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 990                                            VIRTIO_SCSI_F_HOTPLUG, true),
 991     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 992                                                 VIRTIO_SCSI_F_CHANGE, true),
 993     DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
 994                      TYPE_IOTHREAD, IOThread *),
 995     DEFINE_PROP_END_OF_LIST(),
 996 };
 997
 998 static const VMStateDescription vmstate_virtio_scsi = {
 999     .name = "virtio-scsi",
1000     .minimum_version_id = 1,
1001     .version_id = 1,
1002     .fields = (VMStateField[]) {
1003         VMSTATE_VIRTIO_DEVICE,
1004         VMSTATE_END_OF_LIST()
1005     },
1006 };
1007
1008 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
1009 {
1010     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1011     DeviceClass *dc = DEVICE_CLASS(klass);
1012
1013     vdc->get_config = virtio_scsi_get_config;
1014     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1015 }
1016
1017 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
1018 {
1019     DeviceClass *dc = DEVICE_CLASS(klass);
1020     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1021     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1022
1023     device_class_set_props(dc, virtio_scsi_properties);
1024     dc->vmsd = &vmstate_virtio_scsi;
1025     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1026     vdc->realize = virtio_scsi_device_realize;
1027     vdc->unrealize = virtio_scsi_device_unrealize;
1028     vdc->set_config = virtio_scsi_set_config;
1029     vdc->get_features = virtio_scsi_get_features;
1030     vdc->reset = virtio_scsi_reset;
1031     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
1032     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
1033     hc->pre_plug = virtio_scsi_pre_hotplug;
1034     hc->plug = virtio_scsi_hotplug;
1035     hc->unplug = virtio_scsi_hotunplug;
1036 }
1037
1038 static const TypeInfo virtio_scsi_common_info = {
1039     .name = TYPE_VIRTIO_SCSI_COMMON,
1040     .parent = TYPE_VIRTIO_DEVICE,
1041     .instance_size = sizeof(VirtIOSCSICommon),
1042     .abstract = true,
1043     .class_init = virtio_scsi_common_class_init,
1044 };
1045
1046 static const TypeInfo virtio_scsi_info = {
1047     .name = TYPE_VIRTIO_SCSI,
1048     .parent = TYPE_VIRTIO_SCSI_COMMON,
1049     .instance_size = sizeof(VirtIOSCSI),
1050     .class_init = virtio_scsi_class_init,
1051     .interfaces = (InterfaceInfo[]) {
1052         { TYPE_HOTPLUG_HANDLER },
1053         { }
1054     }
1055 };
1056
1057 static void virtio_register_types(void)
1058 {
1059     type_register_static(&virtio_scsi_common_info);
1060     type_register_static(&virtio_scsi_info);
1061 }
1062
1063 type_init(virtio_register_types)