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_malloc(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     qemu_iovec_destroy(&req->resp_iov);
  62     qemu_sglist_destroy(&req->qsgl);
  63     g_free(req);
  64 }
  65
  66 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  67 {
  68     VirtIOSCSI *s = req->dev;
  69     VirtQueue *vq = req->vq;
  70     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  71
  72     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  73     if (req->vring) {
  74         assert(req->vq == NULL);
  75         virtio_scsi_vring_push_notify(req);
  76     } else {
  77         virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  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(void)
  89 {
  90     error_report("wrong size for virtio-scsi headers");
  91     exit(1);
  92 }
  93
  94 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  95                               hwaddr *addr, int num, size_t skip)
  96 {
  97     QEMUSGList *qsgl = &req->qsgl;
  98     size_t copied = 0;
  99
 100     while (num) {
 101         if (skip >= iov->iov_len) {
 102             skip -= iov->iov_len;
 103         } else {
 104             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 105             copied += iov->iov_len - skip;
 106             skip = 0;
 107         }
 108         iov++;
 109         addr++;
 110         num--;
 111     }
 112
 113     assert(skip == 0);
 114     return copied;
 115 }
 116
 117 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 118                                  unsigned req_size, unsigned resp_size)
 119 {
 120     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 121     size_t in_size, out_size;
 122
 123     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 124                    &req->req, req_size) < req_size) {
 125         return -EINVAL;
 126     }
 127
 128     if (qemu_iovec_concat_iov(&req->resp_iov,
 129                               req->elem.in_sg, req->elem.in_num, 0,
 130                               resp_size) < resp_size) {
 131         return -EINVAL;
 132     }
 133
 134     req->resp_size = resp_size;
 135
 136     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 137      * As a workaround, always consider the first buffer as the virtio-scsi
 138      * request/response, making the payload start at the second element
 139      * of the iovec.
 140      *
 141      * The actual length of the response header, stored in req->resp_size,
 142      * does not change.
 143      *
 144      * TODO: always disable this workaround for virtio 1.0 devices.
 145      */
 146     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 147         if (req->elem.out_num) {
 148             req_size = req->elem.out_sg[0].iov_len;
 149         }
 150         if (req->elem.in_num) {
 151             resp_size = req->elem.in_sg[0].iov_len;
 152         }
 153     }
 154
 155     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 156                                &req->elem.out_addr[0], req->elem.out_num,
 157                                req_size);
 158     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 159                               &req->elem.in_addr[0], req->elem.in_num,
 160                               resp_size);
 161
 162     if (out_size && in_size) {
 163         return -ENOTSUP;
 164     }
 165
 166     if (out_size) {
 167         req->mode = SCSI_XFER_TO_DEV;
 168     } else if (in_size) {
 169         req->mode = SCSI_XFER_FROM_DEV;
 170     }
 171
 172     return 0;
 173 }
 174
 175 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 176 {
 177     VirtIOSCSIReq *req = virtio_scsi_init_req(s, vq);
 178     if (!virtqueue_pop(vq, &req->elem)) {
 179         virtio_scsi_free_req(req);
 180         return NULL;
 181     }
 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_queue_get_id(req->vq) - 2;
 190
 191     assert(n < vs->conf.num_queues);
 192     qemu_put_be32s(f, &n);
 193     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(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     VirtIOSCSIReq *req;
 202     uint32_t n;
 203
 204     qemu_get_be32s(f, &n);
 205     assert(n < vs->conf.num_queues);
 206     req = virtio_scsi_init_req(s, vs->cmd_vqs[n]);
 207     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 208     /* TODO: add a way for SCSIBusInfo's load_request to fail,
 209      * and fail migration instead of asserting here.
 210      * When we do, we might be able to re-enable NDEBUG below.
 211      */
 212 #ifdef NDEBUG
 213 #error building with NDEBUG is not supported
 214 #endif
 215     assert(req->elem.in_num <= ARRAY_SIZE(req->elem.in_sg));
 216     assert(req->elem.out_num <= ARRAY_SIZE(req->elem.out_sg));
 217
 218     virtqueue_map_sg(req->elem.in_sg, req->elem.in_addr,
 219                      req->elem.in_num, 1);
 220     virtqueue_map_sg(req->elem.out_sg, req->elem.out_addr,
 221                      req->elem.out_num, 0);
 222
 223     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 224                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 225         error_report("invalid SCSI request migration data");
 226         exit(1);
 227     }
 228
 229     scsi_req_ref(sreq);
 230     req->sreq = sreq;
 231     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 232         assert(req->sreq->cmd.mode == req->mode);
 233     }
 234     return req;
 235 }
 236
 237 typedef struct {
 238     Notifier        notifier;
 239     VirtIOSCSIReq  *tmf_req;
 240 } VirtIOSCSICancelNotifier;
 241
 242 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 243 {
 244     VirtIOSCSICancelNotifier *n = container_of(notifier,
 245                                                VirtIOSCSICancelNotifier,
 246                                                notifier);
 247
 248     if (--n->tmf_req->remaining == 0) {
 249         virtio_scsi_complete_req(n->tmf_req);
 250     }
 251     g_free(n);
 252 }
 253
 254 /* Return 0 if the request is ready to be completed and return to guest;
 255  * -EINPROGRESS if the request is submitted and will be completed later, in the
 256  *  case of async cancellation. */
 257 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 258 {
 259     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 260     SCSIRequest *r, *next;
 261     BusChild *kid;
 262     int target;
 263     int ret = 0;
 264
 265     if (s->dataplane_started) {
 266         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 267     }
 268     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 269     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 270
 271     virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
 272     switch (req->req.tmf.subtype) {
 273     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 274     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 275         if (!d) {
 276             goto fail;
 277         }
 278         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 279             goto incorrect_lun;
 280         }
 281         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 282             VirtIOSCSIReq *cmd_req = r->hba_private;
 283             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 284                 break;
 285             }
 286         }
 287         if (r) {
 288             /*
 289              * Assert that the request has not been completed yet, we
 290              * check for it in the loop above.
 291              */
 292             assert(r->hba_private);
 293             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 294                 /* "If the specified command is present in the task set, then
 295                  * return a service response set to FUNCTION SUCCEEDED".
 296                  */
 297                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 298             } else {
 299                 VirtIOSCSICancelNotifier *notifier;
 300
 301                 req->remaining = 1;
 302                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 303                 notifier->tmf_req = req;
 304                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 305                 scsi_req_cancel_async(r, &notifier->notifier);
 306                 ret = -EINPROGRESS;
 307             }
 308         }
 309         break;
 310
 311     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 312         if (!d) {
 313             goto fail;
 314         }
 315         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 316             goto incorrect_lun;
 317         }
 318         s->resetting++;
 319         qdev_reset_all(&d->qdev);
 320         s->resetting--;
 321         break;
 322
 323     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 324     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 325     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 326         if (!d) {
 327             goto fail;
 328         }
 329         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 330             goto incorrect_lun;
 331         }
 332
 333         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 334          * This way, if the bus starts calling back to the notifiers
 335          * even before we finish the loop, virtio_scsi_cancel_notify
 336          * will not complete the TMF too early.
 337          */
 338         req->remaining = 1;
 339         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 340             if (r->hba_private) {
 341                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 342                     /* "If there is any command present in the task set, then
 343                      * return a service response set to FUNCTION SUCCEEDED".
 344                      */
 345                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 346                     break;
 347                 } else {
 348                     VirtIOSCSICancelNotifier *notifier;
 349
 350                     req->remaining++;
 351                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 352                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 353                     notifier->tmf_req = req;
 354                     scsi_req_cancel_async(r, &notifier->notifier);
 355                 }
 356             }
 357         }
 358         if (--req->remaining > 0) {
 359             ret = -EINPROGRESS;
 360         }
 361         break;
 362
 363     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 364         target = req->req.tmf.lun[1];
 365         s->resetting++;
 366         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 367              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
 368              if (d->channel == 0 && d->id == target) {
 369                 qdev_reset_all(&d->qdev);
 370              }
 371         }
 372         s->resetting--;
 373         break;
 374
 375     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 376     default:
 377         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 378         break;
 379     }
 380
 381     return ret;
 382
 383 incorrect_lun:
 384     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 385     return ret;
 386
 387 fail:
 388     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 389     return ret;
 390 }
 391
 392 void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 393 {
 394     VirtIODevice *vdev = (VirtIODevice *)s;
 395     uint32_t type;
 396     int r = 0;
 397
 398     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 399                 &type, sizeof(type)) < sizeof(type)) {
 400         virtio_scsi_bad_req();
 401         return;
 402     }
 403
 404     virtio_tswap32s(vdev, &type);
 405     if (type == VIRTIO_SCSI_T_TMF) {
 406         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 407                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 408             virtio_scsi_bad_req();
 409         } else {
 410             r = virtio_scsi_do_tmf(s, req);
 411         }
 412
 413     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 414                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 415         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 416                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 417             virtio_scsi_bad_req();
 418         } else {
 419             req->resp.an.event_actual = 0;
 420             req->resp.an.response = VIRTIO_SCSI_S_OK;
 421         }
 422     }
 423     if (r == 0) {
 424         virtio_scsi_complete_req(req);
 425     } else {
 426         assert(r == -EINPROGRESS);
 427     }
 428 }
 429
 430 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 431 {
 432     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 433     VirtIOSCSIReq *req;
 434
 435     if (s->ctx && !s->dataplane_disabled) {
 436         virtio_scsi_dataplane_start(s);
 437         return;
 438     }
 439     while ((req = virtio_scsi_pop_req(s, vq))) {
 440         virtio_scsi_handle_ctrl_req(s, req);
 441     }
 442 }
 443
 444 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 445 {
 446     /* Sense data is not in req->resp and is copied separately
 447      * in virtio_scsi_command_complete.
 448      */
 449     req->resp_size = sizeof(VirtIOSCSICmdResp);
 450     virtio_scsi_complete_req(req);
 451 }
 452
 453 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 454                                          size_t resid)
 455 {
 456     VirtIOSCSIReq *req = r->hba_private;
 457     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 458     uint32_t sense_len;
 459     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 460
 461     if (r->io_canceled) {
 462         return;
 463     }
 464
 465     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 466     req->resp.cmd.status = status;
 467     if (req->resp.cmd.status == GOOD) {
 468         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 469     } else {
 470         req->resp.cmd.resid = 0;
 471         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 472         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 473         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 474                             sense, sense_len);
 475         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 476     }
 477     virtio_scsi_complete_cmd_req(req);
 478 }
 479
 480 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 481                                  uint8_t *buf, void *hba_private)
 482 {
 483     VirtIOSCSIReq *req = hba_private;
 484
 485     if (cmd->len == 0) {
 486         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 487         memcpy(cmd->buf, buf, cmd->len);
 488     }
 489
 490     /* Extract the direction and mode directly from the request, for
 491      * host device passthrough.
 492      */
 493     cmd->xfer = req->qsgl.size;
 494     cmd->mode = req->mode;
 495     return 0;
 496 }
 497
 498 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 499 {
 500     VirtIOSCSIReq *req = r->hba_private;
 501
 502     return &req->qsgl;
 503 }
 504
 505 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 506 {
 507     VirtIOSCSIReq *req = r->hba_private;
 508
 509     if (!req) {
 510         return;
 511     }
 512     if (req->dev->resetting) {
 513         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 514     } else {
 515         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 516     }
 517     virtio_scsi_complete_cmd_req(req);
 518 }
 519
 520 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 521 {
 522     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 523     virtio_scsi_complete_cmd_req(req);
 524 }
 525
 526 bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 527 {
 528     VirtIOSCSICommon *vs = &s->parent_obj;
 529     SCSIDevice *d;
 530     int rc;
 531
 532     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 533                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 534     if (rc < 0) {
 535         if (rc == -ENOTSUP) {
 536             virtio_scsi_fail_cmd_req(req);
 537         } else {
 538             virtio_scsi_bad_req();
 539         }
 540         return false;
 541     }
 542
 543     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 544     if (!d) {
 545         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 546         virtio_scsi_complete_cmd_req(req);
 547         return false;
 548     }
 549     if (s->dataplane_started) {
 550         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 551     }
 552     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 553                              virtio_scsi_get_lun(req->req.cmd.lun),
 554                              req->req.cmd.cdb, req);
 555
 556     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 557         && (req->sreq->cmd.mode != req->mode ||
 558             req->sreq->cmd.xfer > req->qsgl.size)) {
 559         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 560         virtio_scsi_complete_cmd_req(req);
 561         return false;
 562     }
 563     scsi_req_ref(req->sreq);
 564     blk_io_plug(d->conf.blk);
 565     return true;
 566 }
 567
 568 void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 569 {
 570     SCSIRequest *sreq = req->sreq;
 571     if (scsi_req_enqueue(sreq)) {
 572         scsi_req_continue(sreq);
 573     }
 574     blk_io_unplug(sreq->dev->conf.blk);
 575     scsi_req_unref(sreq);
 576 }
 577
 578 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 579 {
 580     /* use non-QOM casts in the data path */
 581     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 582     VirtIOSCSIReq *req, *next;
 583     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 584
 585     if (s->ctx && !s->dataplane_disabled) {
 586         virtio_scsi_dataplane_start(s);
 587         return;
 588     }
 589     while ((req = virtio_scsi_pop_req(s, vq))) {
 590         if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
 591             QTAILQ_INSERT_TAIL(&reqs, req, next);
 592         }
 593     }
 594
 595     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 596         virtio_scsi_handle_cmd_req_submit(s, req);
 597     }
 598 }
 599
 600 static void virtio_scsi_get_config(VirtIODevice *vdev,
 601                                    uint8_t *config)
 602 {
 603     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 604     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 605
 606     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 607     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 608     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 609     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 610     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 611     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 612     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 613     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 614     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 615     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 616 }
 617
 618 static void virtio_scsi_set_config(VirtIODevice *vdev,
 619                                    const uint8_t *config)
 620 {
 621     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 622     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 623
 624     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 625         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 626         error_report("bad data written to virtio-scsi configuration space");
 627         exit(1);
 628     }
 629
 630     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 631     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 632 }
 633
 634 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 635                                          uint64_t requested_features,
 636                                          Error **errp)
 637 {
 638     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 639
 640     /* Firstly sync all virtio-scsi possible supported features */
 641     requested_features |= s->host_features;
 642     return requested_features;
 643 }
 644
 645 static void virtio_scsi_reset(VirtIODevice *vdev)
 646 {
 647     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 648     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 649
 650     if (s->ctx) {
 651         virtio_scsi_dataplane_stop(s);
 652     }
 653     s->resetting++;
 654     qbus_reset_all(&s->bus.qbus);
 655     s->resetting--;
 656
 657     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 658     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 659     s->events_dropped = false;
 660 }
 661
 662 /* The device does not have anything to save beyond the virtio data.
 663  * Request data is saved with callbacks from SCSI devices.
 664  */
 665 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 666 {
 667     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 668     virtio_save(vdev, f);
 669 }
 670
 671 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 672 {
 673     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 674     int ret;
 675
 676     ret = virtio_load(vdev, f, version_id);
 677     if (ret) {
 678         return ret;
 679     }
 680     return 0;
 681 }
 682
 683 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 684                             uint32_t event, uint32_t reason)
 685 {
 686     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 687     VirtIOSCSIReq *req;
 688     VirtIOSCSIEvent *evt;
 689     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 690
 691     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 692         return;
 693     }
 694
 695     if (s->dataplane_started) {
 696         assert(s->ctx);
 697         aio_context_acquire(s->ctx);
 698     }
 699
 700     if (s->dataplane_started) {
 701         req = virtio_scsi_pop_req_vring(s, s->event_vring);
 702     } else {
 703         req = virtio_scsi_pop_req(s, vs->event_vq);
 704     }
 705     if (!req) {
 706         s->events_dropped = true;
 707         goto out;
 708     }
 709
 710     if (s->events_dropped) {
 711         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 712         s->events_dropped = false;
 713     }
 714
 715     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 716         virtio_scsi_bad_req();
 717     }
 718
 719     evt = &req->resp.event;
 720     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 721     evt->event = virtio_tswap32(vdev, event);
 722     evt->reason = virtio_tswap32(vdev, reason);
 723     if (!dev) {
 724         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 725     } else {
 726         evt->lun[0] = 1;
 727         evt->lun[1] = dev->id;
 728
 729         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 730         if (dev->lun >= 256) {
 731             evt->lun[2] = (dev->lun >> 8) | 0x40;
 732         }
 733         evt->lun[3] = dev->lun & 0xFF;
 734     }
 735     virtio_scsi_complete_req(req);
 736 out:
 737     if (s->dataplane_started) {
 738         aio_context_release(s->ctx);
 739     }
 740 }
 741
 742 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 743 {
 744     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 745
 746     if (s->ctx && !s->dataplane_disabled) {
 747         virtio_scsi_dataplane_start(s);
 748         return;
 749     }
 750     if (s->events_dropped) {
 751         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 752     }
 753 }
 754
 755 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 756 {
 757     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 758     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 759
 760     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 761         dev->type != TYPE_ROM) {
 762         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 763                                sense.asc | (sense.ascq << 8));
 764     }
 765 }
 766
 767 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 768                                 Error **errp)
 769 {
 770     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 771     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 772     SCSIDevice *sd = SCSI_DEVICE(dev);
 773
 774     if (s->ctx && !s->dataplane_disabled) {
 775         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 776             return;
 777         }
 778         blk_op_block_all(sd->conf.blk, s->blocker);
 779         aio_context_acquire(s->ctx);
 780         blk_set_aio_context(sd->conf.blk, s->ctx);
 781         aio_context_release(s->ctx);
 782     }
 783
 784     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 785         virtio_scsi_push_event(s, sd,
 786                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 787                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 788     }
 789 }
 790
 791 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 792                                   Error **errp)
 793 {
 794     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 795     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 796     SCSIDevice *sd = SCSI_DEVICE(dev);
 797
 798     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 799         virtio_scsi_push_event(s, sd,
 800                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 801                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 802     }
 803
 804     if (s->ctx) {
 805         blk_op_unblock_all(sd->conf.blk, s->blocker);
 806     }
 807     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 808 }
 809
 810 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 811     .tcq = true,
 812     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 813     .max_target = VIRTIO_SCSI_MAX_TARGET,
 814     .max_lun = VIRTIO_SCSI_MAX_LUN,
 815
 816     .complete = virtio_scsi_command_complete,
 817     .cancel = virtio_scsi_request_cancelled,
 818     .change = virtio_scsi_change,
 819     .parse_cdb = virtio_scsi_parse_cdb,
 820     .get_sg_list = virtio_scsi_get_sg_list,
 821     .save_request = virtio_scsi_save_request,
 822     .load_request = virtio_scsi_load_request,
 823 };
 824
 825 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 826                                 HandleOutput ctrl, HandleOutput evt,
 827                                 HandleOutput cmd)
 828 {
 829     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 830     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 831     int i;
 832
 833     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 834                 sizeof(VirtIOSCSIConfig));
 835
 836     if (s->conf.num_queues == 0 ||
 837             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 838         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 839                          "must be a positive integer less than %d.",
 840                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 841         virtio_cleanup(vdev);
 842         return;
 843     }
 844     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 845     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 846     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 847
 848     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 849                                   ctrl);
 850     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 851                                    evt);
 852     for (i = 0; i < s->conf.num_queues; i++) {
 853         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 854                                          cmd);
 855     }
 856
 857     if (s->conf.iothread) {
 858         virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
 859     }
 860 }
 861
 862 /* Disable dataplane thread during live migration since it does not
 863  * update the dirty memory bitmap yet.
 864  */
 865 static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
 866 {
 867     VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
 868                                  migration_state_notifier);
 869     MigrationState *mig = data;
 870
 871     if (migration_in_setup(mig)) {
 872         if (!s->dataplane_started) {
 873             return;
 874         }
 875         virtio_scsi_dataplane_stop(s);
 876         s->dataplane_disabled = true;
 877     } else if (migration_has_finished(mig) ||
 878                migration_has_failed(mig)) {
 879         if (s->dataplane_started) {
 880             return;
 881         }
 882         blk_drain_all(); /* complete in-flight non-dataplane requests */
 883         s->dataplane_disabled = false;
 884     }
 885 }
 886
 887 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 888 {
 889     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 890     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 891     static int virtio_scsi_id;
 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     if (!dev->hotplugged) {
 908         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 909         if (err != NULL) {
 910             error_propagate(errp, err);
 911             return;
 912         }
 913     }
 914
 915     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 916                     virtio_scsi_save, virtio_scsi_load, s);
 917     s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
 918     add_migration_state_change_notifier(&s->migration_state_notifier);
 919
 920     error_setg(&s->blocker, "block device is in use by data plane");
 921 }
 922
 923 static void virtio_scsi_instance_init(Object *obj)
 924 {
 925     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 926
 927     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 928                              (Object **)&vs->conf.iothread,
 929                              qdev_prop_allow_set_link_before_realize,
 930                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 931 }
 932
 933 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 934 {
 935     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 936     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 937
 938     g_free(vs->cmd_vqs);
 939     virtio_cleanup(vdev);
 940 }
 941
 942 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 943 {
 944     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 945
 946     error_free(s->blocker);
 947
 948     unregister_savevm(dev, "virtio-scsi", s);
 949     remove_migration_state_change_notifier(&s->migration_state_notifier);
 950
 951     virtio_scsi_common_unrealize(dev, errp);
 952 }
 953
 954 static Property virtio_scsi_properties[] = {
 955     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 956     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 957                                                   0xFFFF),
 958     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 959                                                   128),
 960     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 961                                            VIRTIO_SCSI_F_HOTPLUG, true),
 962     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 963                                                 VIRTIO_SCSI_F_CHANGE, true),
 964     DEFINE_PROP_END_OF_LIST(),
 965 };
 966
 967 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 968 {
 969     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 970     DeviceClass *dc = DEVICE_CLASS(klass);
 971
 972     vdc->get_config = virtio_scsi_get_config;
 973     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 974 }
 975
 976 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 977 {
 978     DeviceClass *dc = DEVICE_CLASS(klass);
 979     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 980     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 981
 982     dc->props = virtio_scsi_properties;
 983     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 984     vdc->realize = virtio_scsi_device_realize;
 985     vdc->unrealize = virtio_scsi_device_unrealize;
 986     vdc->set_config = virtio_scsi_set_config;
 987     vdc->get_features = virtio_scsi_get_features;
 988     vdc->reset = virtio_scsi_reset;
 989     hc->plug = virtio_scsi_hotplug;
 990     hc->unplug = virtio_scsi_hotunplug;
 991 }
 992
 993 static const TypeInfo virtio_scsi_common_info = {
 994     .name = TYPE_VIRTIO_SCSI_COMMON,
 995     .parent = TYPE_VIRTIO_DEVICE,
 996     .instance_size = sizeof(VirtIOSCSICommon),
 997     .abstract = true,
 998     .class_init = virtio_scsi_common_class_init,
 999 };
1000
1001 static const TypeInfo virtio_scsi_info = {
1002     .name = TYPE_VIRTIO_SCSI,
1003     .parent = TYPE_VIRTIO_SCSI_COMMON,
1004     .instance_size = sizeof(VirtIOSCSI),
1005     .instance_init = virtio_scsi_instance_init,
1006     .class_init = virtio_scsi_class_init,
1007     .interfaces = (InterfaceInfo[]) {
1008         { TYPE_HOTPLUG_HANDLER },
1009         { }
1010     }
1011 };
1012
1013 static void virtio_register_types(void)
1014 {
1015     type_register_static(&virtio_scsi_common_info);
1016     type_register_static(&virtio_scsi_info);
1017 }
1018
1019 type_init(virtio_register_types)