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 "standard-headers/linux/virtio_ids.h"
  17 #include "hw/virtio/virtio-scsi.h"
  18 #include "qemu/error-report.h"
  19 #include "qemu/iov.h"
  20 #include "sysemu/block-backend.h"
  21 #include <hw/scsi/scsi.h>
  22 #include <block/scsi.h>
  23 #include <hw/virtio/virtio-bus.h>
  24 #include "hw/virtio/virtio-access.h"
  25 #include "migration/migration.h"
  26
  27 static inline int virtio_scsi_get_lun(uint8_t *lun)
  28 {
  29     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  30 }
  31
  32 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  33 {
  34     if (lun[0] != 1) {
  35         return NULL;
  36     }
  37     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  38         return NULL;
  39     }
  40     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  41 }
  42
  43 VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq)
  44 {
  45     VirtIOSCSIReq *req;
  46     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
  47     const size_t zero_skip = offsetof(VirtIOSCSIReq, elem)
  48                              + sizeof(VirtQueueElement);
  49
  50     req = g_slice_alloc(sizeof(*req) + vs->cdb_size);
  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     return req;
  57 }
  58
  59 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  60 {
  61     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)req->dev;
  62
  63     qemu_iovec_destroy(&req->resp_iov);
  64     qemu_sglist_destroy(&req->qsgl);
  65     g_slice_free1(sizeof(*req) + vs->cdb_size, req);
  66 }
  67
  68 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  69 {
  70     VirtIOSCSI *s = req->dev;
  71     VirtQueue *vq = req->vq;
  72     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  73
  74     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  75     if (req->vring) {
  76         assert(req->vq == NULL);
  77         virtio_scsi_vring_push_notify(req);
  78     } else {
  79         virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  80         virtio_notify(vdev, vq);
  81     }
  82
  83     if (req->sreq) {
  84         req->sreq->hba_private = NULL;
  85         scsi_req_unref(req->sreq);
  86     }
  87     virtio_scsi_free_req(req);
  88 }
  89
  90 static void virtio_scsi_bad_req(void)
  91 {
  92     error_report("wrong size for virtio-scsi headers");
  93     exit(1);
  94 }
  95
  96 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  97                               hwaddr *addr, int num, size_t skip)
  98 {
  99     QEMUSGList *qsgl = &req->qsgl;
 100     size_t copied = 0;
 101
 102     while (num) {
 103         if (skip >= iov->iov_len) {
 104             skip -= iov->iov_len;
 105         } else {
 106             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 107             copied += iov->iov_len - skip;
 108             skip = 0;
 109         }
 110         iov++;
 111         addr++;
 112         num--;
 113     }
 114
 115     assert(skip == 0);
 116     return copied;
 117 }
 118
 119 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 120                                  unsigned req_size, unsigned resp_size)
 121 {
 122     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 123     size_t in_size, out_size;
 124
 125     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 126                    &req->req, req_size) < req_size) {
 127         return -EINVAL;
 128     }
 129
 130     if (qemu_iovec_concat_iov(&req->resp_iov,
 131                               req->elem.in_sg, req->elem.in_num, 0,
 132                               resp_size) < resp_size) {
 133         return -EINVAL;
 134     }
 135
 136     req->resp_size = resp_size;
 137
 138     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 139      * As a workaround, always consider the first buffer as the virtio-scsi
 140      * request/response, making the payload start at the second element
 141      * of the iovec.
 142      *
 143      * The actual length of the response header, stored in req->resp_size,
 144      * does not change.
 145      *
 146      * TODO: always disable this workaround for virtio 1.0 devices.
 147      */
 148     if (!virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 149         req_size = req->elem.out_sg[0].iov_len;
 150         resp_size = req->elem.in_sg[0].iov_len;
 151     }
 152
 153     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 154                                &req->elem.out_addr[0], req->elem.out_num,
 155                                req_size);
 156     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 157                               &req->elem.in_addr[0], req->elem.in_num,
 158                               resp_size);
 159
 160     if (out_size && in_size) {
 161         return -ENOTSUP;
 162     }
 163
 164     if (out_size) {
 165         req->mode = SCSI_XFER_TO_DEV;
 166     } else if (in_size) {
 167         req->mode = SCSI_XFER_FROM_DEV;
 168     }
 169
 170     return 0;
 171 }
 172
 173 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 174 {
 175     VirtIOSCSIReq *req = virtio_scsi_init_req(s, vq);
 176     if (!virtqueue_pop(vq, &req->elem)) {
 177         virtio_scsi_free_req(req);
 178         return NULL;
 179     }
 180     return req;
 181 }
 182
 183 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 184 {
 185     VirtIOSCSIReq *req = sreq->hba_private;
 186     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 187     uint32_t n = virtio_queue_get_id(req->vq) - 2;
 188
 189     assert(n < vs->conf.num_queues);
 190     qemu_put_be32s(f, &n);
 191     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 192 }
 193
 194 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 195 {
 196     SCSIBus *bus = sreq->bus;
 197     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 198     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 199     VirtIOSCSIReq *req;
 200     uint32_t n;
 201
 202     qemu_get_be32s(f, &n);
 203     assert(n < vs->conf.num_queues);
 204     req = virtio_scsi_init_req(s, vs->cmd_vqs[n]);
 205     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 206     /* TODO: add a way for SCSIBusInfo's load_request to fail,
 207      * and fail migration instead of asserting here.
 208      * When we do, we might be able to re-enable NDEBUG below.
 209      */
 210 #ifdef NDEBUG
 211 #error building with NDEBUG is not supported
 212 #endif
 213     assert(req->elem.in_num <= ARRAY_SIZE(req->elem.in_sg));
 214     assert(req->elem.out_num <= ARRAY_SIZE(req->elem.out_sg));
 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_slice_free(VirtIOSCSICancelNotifier, n);
 245 }
 246
 247 /* Return 0 if the request is ready to be completed and return to guest;
 248  * -EINPROGRESS if the request is submitted and will be completed later, in the
 249  *  case of async cancellation. */
 250 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 251 {
 252     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 253     SCSIRequest *r, *next;
 254     BusChild *kid;
 255     int target;
 256     int ret = 0;
 257
 258     if (s->dataplane_started) {
 259         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 260     }
 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_slice_new(VirtIOSCSICancelNotifier);
 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_slice_new(VirtIOSCSICancelNotifier);
 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 = DO_UPCAST(SCSIDevice, qdev, 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 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();
 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();
 402         } else {
 403             r = virtio_scsi_do_tmf(s, req);
 404         }
 405
 406     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 407                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 408         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 409                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 410             virtio_scsi_bad_req();
 411         } else {
 412             req->resp.an.event_actual = 0;
 413             req->resp.an.response = VIRTIO_SCSI_S_OK;
 414         }
 415     }
 416     if (r == 0) {
 417         virtio_scsi_complete_req(req);
 418     } else {
 419         assert(r == -EINPROGRESS);
 420     }
 421 }
 422
 423 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 424 {
 425     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 426     VirtIOSCSIReq *req;
 427
 428     if (s->ctx && !s->dataplane_disabled) {
 429         virtio_scsi_dataplane_start(s);
 430         return;
 431     }
 432     while ((req = virtio_scsi_pop_req(s, vq))) {
 433         virtio_scsi_handle_ctrl_req(s, req);
 434     }
 435 }
 436
 437 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 438 {
 439     /* Sense data is not in req->resp and is copied separately
 440      * in virtio_scsi_command_complete.
 441      */
 442     req->resp_size = sizeof(VirtIOSCSICmdResp);
 443     virtio_scsi_complete_req(req);
 444 }
 445
 446 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 447                                          size_t resid)
 448 {
 449     VirtIOSCSIReq *req = r->hba_private;
 450     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 451     uint32_t sense_len;
 452     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 453
 454     if (r->io_canceled) {
 455         return;
 456     }
 457
 458     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 459     req->resp.cmd.status = status;
 460     if (req->resp.cmd.status == GOOD) {
 461         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 462     } else {
 463         req->resp.cmd.resid = 0;
 464         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 465         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 466         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 467                             sense, sense_len);
 468         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 469     }
 470     virtio_scsi_complete_cmd_req(req);
 471 }
 472
 473 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 474                                  uint8_t *buf, void *hba_private)
 475 {
 476     VirtIOSCSIReq *req = hba_private;
 477
 478     if (cmd->len == 0) {
 479         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 480         memcpy(cmd->buf, buf, cmd->len);
 481     }
 482
 483     /* Extract the direction and mode directly from the request, for
 484      * host device passthrough.
 485      */
 486     cmd->xfer = req->qsgl.size;
 487     cmd->mode = req->mode;
 488     return 0;
 489 }
 490
 491 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 492 {
 493     VirtIOSCSIReq *req = r->hba_private;
 494
 495     return &req->qsgl;
 496 }
 497
 498 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 499 {
 500     VirtIOSCSIReq *req = r->hba_private;
 501
 502     if (!req) {
 503         return;
 504     }
 505     if (req->dev->resetting) {
 506         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 507     } else {
 508         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 509     }
 510     virtio_scsi_complete_cmd_req(req);
 511 }
 512
 513 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 514 {
 515     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 516     virtio_scsi_complete_cmd_req(req);
 517 }
 518
 519 bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 520 {
 521     VirtIOSCSICommon *vs = &s->parent_obj;
 522     SCSIDevice *d;
 523     int rc;
 524
 525     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 526                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 527     if (rc < 0) {
 528         if (rc == -ENOTSUP) {
 529             virtio_scsi_fail_cmd_req(req);
 530         } else {
 531             virtio_scsi_bad_req();
 532         }
 533         return false;
 534     }
 535
 536     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 537     if (!d) {
 538         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 539         virtio_scsi_complete_cmd_req(req);
 540         return false;
 541     }
 542     if (s->dataplane_started) {
 543         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 544     }
 545     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 546                              virtio_scsi_get_lun(req->req.cmd.lun),
 547                              req->req.cmd.cdb, req);
 548
 549     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 550         && (req->sreq->cmd.mode != req->mode ||
 551             req->sreq->cmd.xfer > req->qsgl.size)) {
 552         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 553         virtio_scsi_complete_cmd_req(req);
 554         return false;
 555     }
 556     scsi_req_ref(req->sreq);
 557     blk_io_plug(d->conf.blk);
 558     return true;
 559 }
 560
 561 void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 562 {
 563     SCSIRequest *sreq = req->sreq;
 564     if (scsi_req_enqueue(sreq)) {
 565         scsi_req_continue(sreq);
 566     }
 567     blk_io_unplug(sreq->dev->conf.blk);
 568     scsi_req_unref(sreq);
 569 }
 570
 571 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 572 {
 573     /* use non-QOM casts in the data path */
 574     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 575     VirtIOSCSIReq *req, *next;
 576     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 577
 578     if (s->ctx && !s->dataplane_disabled) {
 579         virtio_scsi_dataplane_start(s);
 580         return;
 581     }
 582     while ((req = virtio_scsi_pop_req(s, vq))) {
 583         if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
 584             QTAILQ_INSERT_TAIL(&reqs, req, next);
 585         }
 586     }
 587
 588     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 589         virtio_scsi_handle_cmd_req_submit(s, req);
 590     }
 591 }
 592
 593 static void virtio_scsi_get_config(VirtIODevice *vdev,
 594                                    uint8_t *config)
 595 {
 596     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 597     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 598
 599     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 600     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 601     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 602     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 603     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 604     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 605     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 606     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 607     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 608     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 609 }
 610
 611 static void virtio_scsi_set_config(VirtIODevice *vdev,
 612                                    const uint8_t *config)
 613 {
 614     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 615     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 616
 617     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 618         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 619         error_report("bad data written to virtio-scsi configuration space");
 620         exit(1);
 621     }
 622
 623     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 624     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 625 }
 626
 627 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
 628                                          uint32_t requested_features)
 629 {
 630     return requested_features;
 631 }
 632
 633 static void virtio_scsi_reset(VirtIODevice *vdev)
 634 {
 635     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 636     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 637
 638     if (s->ctx) {
 639         virtio_scsi_dataplane_stop(s);
 640     }
 641     s->resetting++;
 642     qbus_reset_all(&s->bus.qbus);
 643     s->resetting--;
 644
 645     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 646     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 647     s->events_dropped = false;
 648 }
 649
 650 /* The device does not have anything to save beyond the virtio data.
 651  * Request data is saved with callbacks from SCSI devices.
 652  */
 653 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 654 {
 655     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 656     virtio_save(vdev, f);
 657 }
 658
 659 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 660 {
 661     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 662     int ret;
 663
 664     ret = virtio_load(vdev, f, version_id);
 665     if (ret) {
 666         return ret;
 667     }
 668     return 0;
 669 }
 670
 671 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 672                             uint32_t event, uint32_t reason)
 673 {
 674     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 675     VirtIOSCSIReq *req;
 676     VirtIOSCSIEvent *evt;
 677     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 678
 679     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 680         return;
 681     }
 682
 683     if (s->dataplane_started) {
 684         assert(s->ctx);
 685         aio_context_acquire(s->ctx);
 686     }
 687
 688     if (s->dataplane_started) {
 689         req = virtio_scsi_pop_req_vring(s, s->event_vring);
 690     } else {
 691         req = virtio_scsi_pop_req(s, vs->event_vq);
 692     }
 693     if (!req) {
 694         s->events_dropped = true;
 695         goto out;
 696     }
 697
 698     if (s->events_dropped) {
 699         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 700         s->events_dropped = false;
 701     }
 702
 703     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 704         virtio_scsi_bad_req();
 705     }
 706
 707     evt = &req->resp.event;
 708     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 709     evt->event = virtio_tswap32(vdev, event);
 710     evt->reason = virtio_tswap32(vdev, reason);
 711     if (!dev) {
 712         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 713     } else {
 714         evt->lun[0] = 1;
 715         evt->lun[1] = dev->id;
 716
 717         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 718         if (dev->lun >= 256) {
 719             evt->lun[2] = (dev->lun >> 8) | 0x40;
 720         }
 721         evt->lun[3] = dev->lun & 0xFF;
 722     }
 723     virtio_scsi_complete_req(req);
 724 out:
 725     if (s->dataplane_started) {
 726         aio_context_release(s->ctx);
 727     }
 728 }
 729
 730 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 731 {
 732     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 733
 734     if (s->ctx && !s->dataplane_disabled) {
 735         virtio_scsi_dataplane_start(s);
 736         return;
 737     }
 738     if (s->events_dropped) {
 739         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 740     }
 741 }
 742
 743 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 744 {
 745     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 746     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 747
 748     if (virtio_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 749         dev->type != TYPE_ROM) {
 750         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 751                                sense.asc | (sense.ascq << 8));
 752     }
 753 }
 754
 755 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 756                                 Error **errp)
 757 {
 758     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 759     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 760     SCSIDevice *sd = SCSI_DEVICE(dev);
 761
 762     if (s->ctx && !s->dataplane_disabled) {
 763         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 764             return;
 765         }
 766         blk_op_block_all(sd->conf.blk, s->blocker);
 767         aio_context_acquire(s->ctx);
 768         blk_set_aio_context(sd->conf.blk, s->ctx);
 769         aio_context_release(s->ctx);
 770     }
 771
 772     if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 773         virtio_scsi_push_event(s, sd,
 774                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 775                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 776     }
 777 }
 778
 779 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 780                                   Error **errp)
 781 {
 782     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 783     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 784     SCSIDevice *sd = SCSI_DEVICE(dev);
 785
 786     if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 787         virtio_scsi_push_event(s, sd,
 788                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 789                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 790     }
 791
 792     if (s->ctx) {
 793         blk_op_unblock_all(sd->conf.blk, s->blocker);
 794     }
 795     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 796 }
 797
 798 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 799     .tcq = true,
 800     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 801     .max_target = VIRTIO_SCSI_MAX_TARGET,
 802     .max_lun = VIRTIO_SCSI_MAX_LUN,
 803
 804     .complete = virtio_scsi_command_complete,
 805     .cancel = virtio_scsi_request_cancelled,
 806     .change = virtio_scsi_change,
 807     .parse_cdb = virtio_scsi_parse_cdb,
 808     .get_sg_list = virtio_scsi_get_sg_list,
 809     .save_request = virtio_scsi_save_request,
 810     .load_request = virtio_scsi_load_request,
 811 };
 812
 813 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 814                                 HandleOutput ctrl, HandleOutput evt,
 815                                 HandleOutput cmd)
 816 {
 817     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 818     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 819     int i;
 820
 821     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 822                 sizeof(VirtIOSCSIConfig));
 823
 824     if (s->conf.num_queues == 0 ||
 825             s->conf.num_queues > VIRTIO_PCI_QUEUE_MAX - 2) {
 826         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 827                          "must be a positive integer less than %d.",
 828                    s->conf.num_queues, VIRTIO_PCI_QUEUE_MAX - 2);
 829         virtio_cleanup(vdev);
 830         return;
 831     }
 832     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 833     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 834     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 835
 836     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 837                                   ctrl);
 838     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 839                                    evt);
 840     for (i = 0; i < s->conf.num_queues; i++) {
 841         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 842                                          cmd);
 843     }
 844
 845     if (s->conf.iothread) {
 846         virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
 847     }
 848 }
 849
 850 /* Disable dataplane thread during live migration since it does not
 851  * update the dirty memory bitmap yet.
 852  */
 853 static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
 854 {
 855     VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
 856                                  migration_state_notifier);
 857     MigrationState *mig = data;
 858
 859     if (migration_in_setup(mig)) {
 860         if (!s->dataplane_started) {
 861             return;
 862         }
 863         virtio_scsi_dataplane_stop(s);
 864         s->dataplane_disabled = true;
 865     } else if (migration_has_finished(mig) ||
 866                migration_has_failed(mig)) {
 867         if (s->dataplane_started) {
 868             return;
 869         }
 870         blk_drain_all(); /* complete in-flight non-dataplane requests */
 871         s->dataplane_disabled = false;
 872     }
 873 }
 874
 875 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 876 {
 877     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 878     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 879     static int virtio_scsi_id;
 880     Error *err = NULL;
 881
 882     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 883                                virtio_scsi_handle_event,
 884                                virtio_scsi_handle_cmd);
 885     if (err != NULL) {
 886         error_propagate(errp, err);
 887         return;
 888     }
 889
 890     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 891                  &virtio_scsi_scsi_info, vdev->bus_name);
 892     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 893     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 894
 895     if (!dev->hotplugged) {
 896         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 897         if (err != NULL) {
 898             error_propagate(errp, err);
 899             return;
 900         }
 901     }
 902
 903     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 904                     virtio_scsi_save, virtio_scsi_load, s);
 905     s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
 906     add_migration_state_change_notifier(&s->migration_state_notifier);
 907
 908     error_setg(&s->blocker, "block device is in use by data plane");
 909 }
 910
 911 static void virtio_scsi_instance_init(Object *obj)
 912 {
 913     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 914
 915     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 916                              (Object **)&vs->conf.iothread,
 917                              qdev_prop_allow_set_link_before_realize,
 918                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 919 }
 920
 921 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 922 {
 923     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 924     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 925
 926     g_free(vs->cmd_vqs);
 927     virtio_cleanup(vdev);
 928 }
 929
 930 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 931 {
 932     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 933
 934     error_free(s->blocker);
 935
 936     unregister_savevm(dev, "virtio-scsi", s);
 937     remove_migration_state_change_notifier(&s->migration_state_notifier);
 938
 939     virtio_scsi_common_unrealize(dev, errp);
 940 }
 941
 942 static Property virtio_scsi_properties[] = {
 943     DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOSCSI, parent_obj.conf),
 944     DEFINE_PROP_END_OF_LIST(),
 945 };
 946
 947 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 948 {
 949     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 950     DeviceClass *dc = DEVICE_CLASS(klass);
 951
 952     vdc->get_config = virtio_scsi_get_config;
 953     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 954 }
 955
 956 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 957 {
 958     DeviceClass *dc = DEVICE_CLASS(klass);
 959     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 960     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 961
 962     dc->props = virtio_scsi_properties;
 963     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 964     vdc->realize = virtio_scsi_device_realize;
 965     vdc->unrealize = virtio_scsi_device_unrealize;
 966     vdc->set_config = virtio_scsi_set_config;
 967     vdc->get_features = virtio_scsi_get_features;
 968     vdc->reset = virtio_scsi_reset;
 969     hc->plug = virtio_scsi_hotplug;
 970     hc->unplug = virtio_scsi_hotunplug;
 971 }
 972
 973 static const TypeInfo virtio_scsi_common_info = {
 974     .name = TYPE_VIRTIO_SCSI_COMMON,
 975     .parent = TYPE_VIRTIO_DEVICE,
 976     .instance_size = sizeof(VirtIOSCSICommon),
 977     .abstract = true,
 978     .class_init = virtio_scsi_common_class_init,
 979 };
 980
 981 static const TypeInfo virtio_scsi_info = {
 982     .name = TYPE_VIRTIO_SCSI,
 983     .parent = TYPE_VIRTIO_SCSI_COMMON,
 984     .instance_size = sizeof(VirtIOSCSI),
 985     .instance_init = virtio_scsi_instance_init,
 986     .class_init = virtio_scsi_class_init,
 987     .interfaces = (InterfaceInfo[]) {
 988         { TYPE_HOTPLUG_HANDLER },
 989         { }
 990     }
 991 };
 992
 993 static void virtio_register_types(void)
 994 {
 995     type_register_static(&virtio_scsi_common_info);
 996     type_register_static(&virtio_scsi_info);
 997 }
 998
 999 type_init(virtio_register_types)