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 "hw/virtio/virtio-scsi.h"
  17 #include "qemu/error-report.h"
  18 #include "qemu/iov.h"
  19 #include "sysemu/block-backend.h"
  20 #include <hw/scsi/scsi.h>
  21 #include <block/scsi.h>
  22 #include <hw/virtio/virtio-bus.h>
  23 #include "hw/virtio/virtio-access.h"
  24 #include "migration/migration.h"
  25
  26 static inline int virtio_scsi_get_lun(uint8_t *lun)
  27 {
  28     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  29 }
  30
  31 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  32 {
  33     if (lun[0] != 1) {
  34         return NULL;
  35     }
  36     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  37         return NULL;
  38     }
  39     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  40 }
  41
  42 VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq)
  43 {
  44     VirtIOSCSIReq *req;
  45     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
  46     const size_t zero_skip = offsetof(VirtIOSCSIReq, elem)
  47                              + sizeof(VirtQueueElement);
  48
  49     req = g_slice_alloc(sizeof(*req) + vs->cdb_size);
  50     req->vq = vq;
  51     req->dev = s;
  52     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, &address_space_memory);
  53     qemu_iovec_init(&req->resp_iov, 1);
  54     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  55     return req;
  56 }
  57
  58 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  59 {
  60     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)req->dev;
  61
  62     qemu_iovec_destroy(&req->resp_iov);
  63     qemu_sglist_destroy(&req->qsgl);
  64     g_slice_free1(sizeof(*req) + vs->cdb_size, 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     if (req->vring) {
  75         assert(req->vq == NULL);
  76         virtio_scsi_vring_push_notify(req);
  77     } else {
  78         virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  79         virtio_notify(vdev, vq);
  80     }
  81
  82     if (req->sreq) {
  83         req->sreq->hba_private = NULL;
  84         scsi_req_unref(req->sreq);
  85     }
  86     virtio_scsi_free_req(req);
  87 }
  88
  89 static void virtio_scsi_bad_req(void)
  90 {
  91     error_report("wrong size for virtio-scsi headers");
  92     exit(1);
  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     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     req->resp_size = resp_size;
 134
 135     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 136                                &req->elem.out_addr[0], req->elem.out_num,
 137                                req_size);
 138     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 139                               &req->elem.in_addr[0], req->elem.in_num,
 140                               resp_size);
 141
 142     if (out_size && in_size) {
 143         return -ENOTSUP;
 144     }
 145
 146     if (out_size) {
 147         req->mode = SCSI_XFER_TO_DEV;
 148     } else if (in_size) {
 149         req->mode = SCSI_XFER_FROM_DEV;
 150     }
 151
 152     return 0;
 153 }
 154
 155 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 156 {
 157     VirtIOSCSIReq *req = virtio_scsi_init_req(s, vq);
 158     if (!virtqueue_pop(vq, &req->elem)) {
 159         virtio_scsi_free_req(req);
 160         return NULL;
 161     }
 162     return req;
 163 }
 164
 165 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 166 {
 167     VirtIOSCSIReq *req = sreq->hba_private;
 168     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 169     uint32_t n = virtio_queue_get_id(req->vq) - 2;
 170
 171     assert(n < vs->conf.num_queues);
 172     qemu_put_be32s(f, &n);
 173     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 174 }
 175
 176 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 177 {
 178     SCSIBus *bus = sreq->bus;
 179     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 180     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 181     VirtIOSCSIReq *req;
 182     uint32_t n;
 183
 184     qemu_get_be32s(f, &n);
 185     assert(n < vs->conf.num_queues);
 186     req = virtio_scsi_init_req(s, vs->cmd_vqs[n]);
 187     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 188     /* TODO: add a way for SCSIBusInfo's load_request to fail,
 189      * and fail migration instead of asserting here.
 190      * When we do, we might be able to re-enable NDEBUG below.
 191      */
 192 #ifdef NDEBUG
 193 #error building with NDEBUG is not supported
 194 #endif
 195     assert(req->elem.in_num <= ARRAY_SIZE(req->elem.in_sg));
 196     assert(req->elem.out_num <= ARRAY_SIZE(req->elem.out_sg));
 197
 198     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 199                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 200         error_report("invalid SCSI request migration data");
 201         exit(1);
 202     }
 203
 204     scsi_req_ref(sreq);
 205     req->sreq = sreq;
 206     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 207         assert(req->sreq->cmd.mode == req->mode);
 208     }
 209     return req;
 210 }
 211
 212 typedef struct {
 213     Notifier        notifier;
 214     VirtIOSCSIReq  *tmf_req;
 215 } VirtIOSCSICancelNotifier;
 216
 217 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 218 {
 219     VirtIOSCSICancelNotifier *n = container_of(notifier,
 220                                                VirtIOSCSICancelNotifier,
 221                                                notifier);
 222
 223     if (--n->tmf_req->remaining == 0) {
 224         virtio_scsi_complete_req(n->tmf_req);
 225     }
 226     g_slice_free(VirtIOSCSICancelNotifier, n);
 227 }
 228
 229 /* Return 0 if the request is ready to be completed and return to guest;
 230  * -EINPROGRESS if the request is submitted and will be completed later, in the
 231  *  case of async cancellation. */
 232 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 233 {
 234     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 235     SCSIRequest *r, *next;
 236     BusChild *kid;
 237     int target;
 238     int ret = 0;
 239
 240     if (s->dataplane_started && blk_get_aio_context(d->conf.blk) != s->ctx) {
 241         aio_context_acquire(s->ctx);
 242         blk_set_aio_context(d->conf.blk, s->ctx);
 243         aio_context_release(s->ctx);
 244     }
 245     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 246     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 247
 248     virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
 249     switch (req->req.tmf.subtype) {
 250     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 251     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 252         if (!d) {
 253             goto fail;
 254         }
 255         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 256             goto incorrect_lun;
 257         }
 258         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 259             VirtIOSCSIReq *cmd_req = r->hba_private;
 260             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 261                 break;
 262             }
 263         }
 264         if (r) {
 265             /*
 266              * Assert that the request has not been completed yet, we
 267              * check for it in the loop above.
 268              */
 269             assert(r->hba_private);
 270             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 271                 /* "If the specified command is present in the task set, then
 272                  * return a service response set to FUNCTION SUCCEEDED".
 273                  */
 274                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 275             } else {
 276                 VirtIOSCSICancelNotifier *notifier;
 277
 278                 req->remaining = 1;
 279                 notifier = g_slice_new(VirtIOSCSICancelNotifier);
 280                 notifier->tmf_req = req;
 281                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 282                 scsi_req_cancel_async(r, &notifier->notifier);
 283                 ret = -EINPROGRESS;
 284             }
 285         }
 286         break;
 287
 288     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 289         if (!d) {
 290             goto fail;
 291         }
 292         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 293             goto incorrect_lun;
 294         }
 295         s->resetting++;
 296         qdev_reset_all(&d->qdev);
 297         s->resetting--;
 298         break;
 299
 300     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 301     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 302     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 303         if (!d) {
 304             goto fail;
 305         }
 306         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 307             goto incorrect_lun;
 308         }
 309
 310         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 311          * This way, if the bus starts calling back to the notifiers
 312          * even before we finish the loop, virtio_scsi_cancel_notify
 313          * will not complete the TMF too early.
 314          */
 315         req->remaining = 1;
 316         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 317             if (r->hba_private) {
 318                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 319                     /* "If there is any command present in the task set, then
 320                      * return a service response set to FUNCTION SUCCEEDED".
 321                      */
 322                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 323                     break;
 324                 } else {
 325                     VirtIOSCSICancelNotifier *notifier;
 326
 327                     req->remaining++;
 328                     notifier = g_slice_new(VirtIOSCSICancelNotifier);
 329                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 330                     notifier->tmf_req = req;
 331                     scsi_req_cancel_async(r, &notifier->notifier);
 332                 }
 333             }
 334         }
 335         if (--req->remaining > 0) {
 336             ret = -EINPROGRESS;
 337         }
 338         break;
 339
 340     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 341         target = req->req.tmf.lun[1];
 342         s->resetting++;
 343         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 344              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
 345              if (d->channel == 0 && d->id == target) {
 346                 qdev_reset_all(&d->qdev);
 347              }
 348         }
 349         s->resetting--;
 350         break;
 351
 352     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 353     default:
 354         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 355         break;
 356     }
 357
 358     return ret;
 359
 360 incorrect_lun:
 361     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 362     return ret;
 363
 364 fail:
 365     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 366     return ret;
 367 }
 368
 369 void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 370 {
 371     VirtIODevice *vdev = (VirtIODevice *)s;
 372     int type;
 373     int r = 0;
 374
 375     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 376                 &type, sizeof(type)) < sizeof(type)) {
 377         virtio_scsi_bad_req();
 378         return;
 379     }
 380
 381     virtio_tswap32s(vdev, &req->req.tmf.type);
 382     if (req->req.tmf.type == VIRTIO_SCSI_T_TMF) {
 383         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 384                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 385             virtio_scsi_bad_req();
 386         } else {
 387             r = virtio_scsi_do_tmf(s, req);
 388         }
 389
 390     } else if (req->req.tmf.type == VIRTIO_SCSI_T_AN_QUERY ||
 391             req->req.tmf.type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 392         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 393                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 394             virtio_scsi_bad_req();
 395         } else {
 396             req->resp.an.event_actual = 0;
 397             req->resp.an.response = VIRTIO_SCSI_S_OK;
 398         }
 399     }
 400     if (r == 0) {
 401         virtio_scsi_complete_req(req);
 402     } else {
 403         assert(r == -EINPROGRESS);
 404     }
 405 }
 406
 407 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 408 {
 409     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 410     VirtIOSCSIReq *req;
 411
 412     if (s->ctx && !s->dataplane_disabled) {
 413         virtio_scsi_dataplane_start(s);
 414         return;
 415     }
 416     while ((req = virtio_scsi_pop_req(s, vq))) {
 417         virtio_scsi_handle_ctrl_req(s, req);
 418     }
 419 }
 420
 421 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 422 {
 423     /* Sense data is not in req->resp and is copied separately
 424      * in virtio_scsi_command_complete.
 425      */
 426     req->resp_size = sizeof(VirtIOSCSICmdResp);
 427     virtio_scsi_complete_req(req);
 428 }
 429
 430 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 431                                          size_t resid)
 432 {
 433     VirtIOSCSIReq *req = r->hba_private;
 434     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 435     uint32_t sense_len;
 436     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 437
 438     if (r->io_canceled) {
 439         return;
 440     }
 441
 442     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 443     req->resp.cmd.status = status;
 444     if (req->resp.cmd.status == GOOD) {
 445         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 446     } else {
 447         req->resp.cmd.resid = 0;
 448         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 449         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 450         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 451                             &req->resp, sense_len);
 452         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 453     }
 454     virtio_scsi_complete_cmd_req(req);
 455 }
 456
 457 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 458                                  uint8_t *buf, void *hba_private)
 459 {
 460     VirtIOSCSIReq *req = hba_private;
 461
 462     if (cmd->len == 0) {
 463         cmd->len = MIN(VIRTIO_SCSI_CDB_SIZE, SCSI_CMD_BUF_SIZE);
 464         memcpy(cmd->buf, buf, cmd->len);
 465     }
 466
 467     /* Extract the direction and mode directly from the request, for
 468      * host device passthrough.
 469      */
 470     cmd->xfer = req->qsgl.size;
 471     cmd->mode = req->mode;
 472     return 0;
 473 }
 474
 475 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 476 {
 477     VirtIOSCSIReq *req = r->hba_private;
 478
 479     return &req->qsgl;
 480 }
 481
 482 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 483 {
 484     VirtIOSCSIReq *req = r->hba_private;
 485
 486     if (!req) {
 487         return;
 488     }
 489     if (req->dev->resetting) {
 490         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 491     } else {
 492         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 493     }
 494     virtio_scsi_complete_cmd_req(req);
 495 }
 496
 497 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 498 {
 499     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 500     virtio_scsi_complete_cmd_req(req);
 501 }
 502
 503 bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 504 {
 505     VirtIOSCSICommon *vs = &s->parent_obj;
 506     SCSIDevice *d;
 507     int rc;
 508
 509     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 510                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 511     if (rc < 0) {
 512         if (rc == -ENOTSUP) {
 513             virtio_scsi_fail_cmd_req(req);
 514         } else {
 515             virtio_scsi_bad_req();
 516         }
 517         return false;
 518     }
 519
 520     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 521     if (!d) {
 522         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 523         virtio_scsi_complete_cmd_req(req);
 524         return false;
 525     }
 526     if (s->dataplane_started && blk_get_aio_context(d->conf.blk) != s->ctx) {
 527         aio_context_acquire(s->ctx);
 528         blk_set_aio_context(d->conf.blk, s->ctx);
 529         aio_context_release(s->ctx);
 530     }
 531     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 532                              virtio_scsi_get_lun(req->req.cmd.lun),
 533                              req->req.cdb, req);
 534
 535     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 536         && (req->sreq->cmd.mode != req->mode ||
 537             req->sreq->cmd.xfer > req->qsgl.size)) {
 538         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 539         virtio_scsi_complete_cmd_req(req);
 540         return false;
 541     }
 542     scsi_req_ref(req->sreq);
 543     blk_io_plug(d->conf.blk);
 544     return true;
 545 }
 546
 547 void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 548 {
 549     SCSIRequest *sreq = req->sreq;
 550     if (scsi_req_enqueue(sreq)) {
 551         scsi_req_continue(sreq);
 552     }
 553     blk_io_unplug(sreq->dev->conf.blk);
 554     scsi_req_unref(sreq);
 555 }
 556
 557 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 558 {
 559     /* use non-QOM casts in the data path */
 560     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 561     VirtIOSCSIReq *req, *next;
 562     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 563
 564     if (s->ctx && !s->dataplane_disabled) {
 565         virtio_scsi_dataplane_start(s);
 566         return;
 567     }
 568     while ((req = virtio_scsi_pop_req(s, vq))) {
 569         if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
 570             QTAILQ_INSERT_TAIL(&reqs, req, next);
 571         }
 572     }
 573
 574     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 575         virtio_scsi_handle_cmd_req_submit(s, req);
 576     }
 577 }
 578
 579 static void virtio_scsi_get_config(VirtIODevice *vdev,
 580                                    uint8_t *config)
 581 {
 582     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 583     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 584
 585     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 586     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 587     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 588     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 589     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 590     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 591     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 592     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 593     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 594     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 595 }
 596
 597 static void virtio_scsi_set_config(VirtIODevice *vdev,
 598                                    const uint8_t *config)
 599 {
 600     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 601     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 602
 603     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 604         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 605         error_report("bad data written to virtio-scsi configuration space");
 606         exit(1);
 607     }
 608
 609     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 610     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 611 }
 612
 613 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
 614                                          uint32_t requested_features)
 615 {
 616     return requested_features;
 617 }
 618
 619 static void virtio_scsi_reset(VirtIODevice *vdev)
 620 {
 621     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 622     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 623
 624     if (s->ctx) {
 625         virtio_scsi_dataplane_stop(s);
 626     }
 627     s->resetting++;
 628     qbus_reset_all(&s->bus.qbus);
 629     s->resetting--;
 630
 631     vs->sense_size = VIRTIO_SCSI_SENSE_SIZE;
 632     vs->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 633     s->events_dropped = false;
 634 }
 635
 636 /* The device does not have anything to save beyond the virtio data.
 637  * Request data is saved with callbacks from SCSI devices.
 638  */
 639 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 640 {
 641     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 642     virtio_save(vdev, f);
 643 }
 644
 645 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 646 {
 647     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 648     int ret;
 649
 650     ret = virtio_load(vdev, f, version_id);
 651     if (ret) {
 652         return ret;
 653     }
 654     return 0;
 655 }
 656
 657 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 658                             uint32_t event, uint32_t reason)
 659 {
 660     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 661     VirtIOSCSIReq *req;
 662     VirtIOSCSIEvent *evt;
 663     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 664
 665     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 666         return;
 667     }
 668
 669     if (s->dataplane_started) {
 670         assert(s->ctx);
 671         aio_context_acquire(s->ctx);
 672     }
 673
 674     if (s->dataplane_started) {
 675         req = virtio_scsi_pop_req_vring(s, s->event_vring);
 676     } else {
 677         req = virtio_scsi_pop_req(s, vs->event_vq);
 678     }
 679     if (!req) {
 680         s->events_dropped = true;
 681         goto out;
 682     }
 683
 684     if (s->events_dropped) {
 685         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 686         s->events_dropped = false;
 687     }
 688
 689     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 690         virtio_scsi_bad_req();
 691     }
 692
 693     evt = &req->resp.event;
 694     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 695     evt->event = virtio_tswap32(vdev, event);
 696     evt->reason = virtio_tswap32(vdev, reason);
 697     if (!dev) {
 698         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 699     } else {
 700         evt->lun[0] = 1;
 701         evt->lun[1] = dev->id;
 702
 703         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 704         if (dev->lun >= 256) {
 705             evt->lun[2] = (dev->lun >> 8) | 0x40;
 706         }
 707         evt->lun[3] = dev->lun & 0xFF;
 708     }
 709     virtio_scsi_complete_req(req);
 710 out:
 711     if (s->dataplane_started) {
 712         aio_context_release(s->ctx);
 713     }
 714 }
 715
 716 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 717 {
 718     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 719
 720     if (s->ctx && !s->dataplane_disabled) {
 721         virtio_scsi_dataplane_start(s);
 722         return;
 723     }
 724     if (s->events_dropped) {
 725         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 726     }
 727 }
 728
 729 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 730 {
 731     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 732     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 733
 734     if (((vdev->guest_features >> VIRTIO_SCSI_F_CHANGE) & 1) &&
 735         dev->type != TYPE_ROM) {
 736         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 737                                sense.asc | (sense.ascq << 8));
 738     }
 739 }
 740
 741 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 742                                 Error **errp)
 743 {
 744     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 745
 746     if ((vdev->guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
 747         virtio_scsi_push_event(VIRTIO_SCSI(hotplug_dev), SCSI_DEVICE(dev),
 748                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 749                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 750     }
 751 }
 752
 753 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 754                                   Error **errp)
 755 {
 756     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 757
 758     if ((vdev->guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
 759         virtio_scsi_push_event(VIRTIO_SCSI(hotplug_dev), SCSI_DEVICE(dev),
 760                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 761                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 762     }
 763     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 764 }
 765
 766 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 767     .tcq = true,
 768     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 769     .max_target = VIRTIO_SCSI_MAX_TARGET,
 770     .max_lun = VIRTIO_SCSI_MAX_LUN,
 771
 772     .complete = virtio_scsi_command_complete,
 773     .cancel = virtio_scsi_request_cancelled,
 774     .change = virtio_scsi_change,
 775     .parse_cdb = virtio_scsi_parse_cdb,
 776     .get_sg_list = virtio_scsi_get_sg_list,
 777     .save_request = virtio_scsi_save_request,
 778     .load_request = virtio_scsi_load_request,
 779 };
 780
 781 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 782                                 HandleOutput ctrl, HandleOutput evt,
 783                                 HandleOutput cmd)
 784 {
 785     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 786     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 787     int i;
 788
 789     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 790                 sizeof(VirtIOSCSIConfig));
 791
 792     if (s->conf.num_queues <= 0 || s->conf.num_queues > VIRTIO_PCI_QUEUE_MAX) {
 793         error_setg(errp, "Invalid number of queues (= %" PRId32 "), "
 794                          "must be a positive integer less than %d.",
 795                    s->conf.num_queues, VIRTIO_PCI_QUEUE_MAX);
 796         return;
 797     }
 798     s->cmd_vqs = g_malloc0(s->conf.num_queues * sizeof(VirtQueue *));
 799     s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
 800     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 801
 802     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 803                                   ctrl);
 804     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 805                                    evt);
 806     for (i = 0; i < s->conf.num_queues; i++) {
 807         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 808                                          cmd);
 809     }
 810
 811     if (s->conf.iothread) {
 812         virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
 813     }
 814 }
 815
 816 /* Disable dataplane thread during live migration since it does not
 817  * update the dirty memory bitmap yet.
 818  */
 819 static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
 820 {
 821     VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
 822                                  migration_state_notifier);
 823     MigrationState *mig = data;
 824
 825     if (migration_in_setup(mig)) {
 826         if (!s->dataplane_started) {
 827             return;
 828         }
 829         virtio_scsi_dataplane_stop(s);
 830         s->dataplane_disabled = true;
 831     } else if (migration_has_finished(mig) ||
 832                migration_has_failed(mig)) {
 833         if (s->dataplane_started) {
 834             return;
 835         }
 836         blk_drain_all(); /* complete in-flight non-dataplane requests */
 837         s->dataplane_disabled = false;
 838     }
 839 }
 840
 841 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 842 {
 843     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 844     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 845     static int virtio_scsi_id;
 846     Error *err = NULL;
 847
 848     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 849                                virtio_scsi_handle_event,
 850                                virtio_scsi_handle_cmd);
 851     if (err != NULL) {
 852         error_propagate(errp, err);
 853         return;
 854     }
 855
 856     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 857                  &virtio_scsi_scsi_info, vdev->bus_name);
 858     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 859     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 860
 861     if (!dev->hotplugged) {
 862         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 863         if (err != NULL) {
 864             error_propagate(errp, err);
 865             return;
 866         }
 867     }
 868
 869     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 870                     virtio_scsi_save, virtio_scsi_load, s);
 871     s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
 872     add_migration_state_change_notifier(&s->migration_state_notifier);
 873 }
 874
 875 static void virtio_scsi_instance_init(Object *obj)
 876 {
 877     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 878
 879     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 880                              (Object **)&vs->conf.iothread,
 881                              qdev_prop_allow_set_link_before_realize,
 882                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 883 }
 884
 885 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 886 {
 887     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 888     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 889
 890     g_free(vs->cmd_vqs);
 891     virtio_cleanup(vdev);
 892 }
 893
 894 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 895 {
 896     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 897
 898     unregister_savevm(dev, "virtio-scsi", s);
 899     remove_migration_state_change_notifier(&s->migration_state_notifier);
 900
 901     virtio_scsi_common_unrealize(dev, errp);
 902 }
 903
 904 static Property virtio_scsi_properties[] = {
 905     DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOSCSI, parent_obj.conf),
 906     DEFINE_PROP_END_OF_LIST(),
 907 };
 908
 909 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 910 {
 911     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 912     DeviceClass *dc = DEVICE_CLASS(klass);
 913
 914     vdc->get_config = virtio_scsi_get_config;
 915     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 916 }
 917
 918 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 919 {
 920     DeviceClass *dc = DEVICE_CLASS(klass);
 921     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 922     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 923
 924     dc->props = virtio_scsi_properties;
 925     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 926     vdc->realize = virtio_scsi_device_realize;
 927     vdc->unrealize = virtio_scsi_device_unrealize;
 928     vdc->set_config = virtio_scsi_set_config;
 929     vdc->get_features = virtio_scsi_get_features;
 930     vdc->reset = virtio_scsi_reset;
 931     hc->plug = virtio_scsi_hotplug;
 932     hc->unplug = virtio_scsi_hotunplug;
 933 }
 934
 935 static const TypeInfo virtio_scsi_common_info = {
 936     .name = TYPE_VIRTIO_SCSI_COMMON,
 937     .parent = TYPE_VIRTIO_DEVICE,
 938     .instance_size = sizeof(VirtIOSCSICommon),
 939     .abstract = true,
 940     .class_init = virtio_scsi_common_class_init,
 941 };
 942
 943 static const TypeInfo virtio_scsi_info = {
 944     .name = TYPE_VIRTIO_SCSI,
 945     .parent = TYPE_VIRTIO_SCSI_COMMON,
 946     .instance_size = sizeof(VirtIOSCSI),
 947     .instance_init = virtio_scsi_instance_init,
 948     .class_init = virtio_scsi_class_init,
 949     .interfaces = (InterfaceInfo[]) {
 950         { TYPE_HOTPLUG_HANDLER },
 951         { }
 952     }
 953 };
 954
 955 static void virtio_register_types(void)
 956 {
 957     type_register_static(&virtio_scsi_common_info);
 958     type_register_static(&virtio_scsi_info);
 959 }
 960
 961 type_init(virtio_register_types)