hw/scsi/virtio-scsi.c

   1 /*
   2  * Virtio SCSI HBA
   3  *
   4  * Copyright IBM, Corp. 2010
   5  * Copyright Red Hat, Inc. 2011
   6  *
   7  * Authors:
   8  *   Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
   9  *   Paolo Bonzini      <pbonzini@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include "qemu/osdep.h"
  17 #include "qapi/error.h"
  18 #include "standard-headers/linux/virtio_ids.h"
  19 #include "hw/virtio/virtio-scsi.h"
  20 #include "migration/qemu-file-types.h"
  21 #include "qemu/error-report.h"
  22 #include "qemu/iov.h"
  23 #include "qemu/module.h"
  24 #include "sysemu/block-backend.h"
  25 #include "hw/qdev-properties.h"
  26 #include "hw/scsi/scsi.h"
  27 #include "scsi/constants.h"
  28 #include "hw/virtio/virtio-bus.h"
  29 #include "hw/virtio/virtio-access.h"
  30 #include "trace.h"
  31
  32 static inline int virtio_scsi_get_lun(uint8_t *lun)
  33 {
  34     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  35 }
  36
  37 static inline SCSIDevice *virtio_scsi_device_get(VirtIOSCSI *s, uint8_t *lun)
  38 {
  39     if (lun[0] != 1) {
  40         return NULL;
  41     }
  42     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  43         return NULL;
  44     }
  45     return scsi_device_get(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  46 }
  47
  48 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  49 {
  50     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  51     const size_t zero_skip =
  52         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  53
  54     req->vq = vq;
  55     req->dev = s;
  56     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
  57     qemu_iovec_init(&req->resp_iov, 1);
  58     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  59 }
  60
  61 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  62 {
  63     qemu_iovec_destroy(&req->resp_iov);
  64     qemu_sglist_destroy(&req->qsgl);
  65     g_free(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     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  76     if (s->dataplane_started && !s->dataplane_fenced) {
  77         virtio_notify_irqfd(vdev, vq);
  78     } else {
  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(VirtIOSCSIReq *req)
  90 {
  91     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
  92     virtqueue_detach_element(req->vq, &req->elem, 0);
  93     virtio_scsi_free_req(req);
  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_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 149         if (req->elem.out_num) {
 150             req_size = req->elem.out_sg[0].iov_len;
 151         }
 152         if (req->elem.in_num) {
 153             resp_size = req->elem.in_sg[0].iov_len;
 154         }
 155     }
 156
 157     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 158                                &req->elem.out_addr[0], req->elem.out_num,
 159                                req_size);
 160     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 161                               &req->elem.in_addr[0], req->elem.in_num,
 162                               resp_size);
 163
 164     if (out_size && in_size) {
 165         return -ENOTSUP;
 166     }
 167
 168     if (out_size) {
 169         req->mode = SCSI_XFER_TO_DEV;
 170     } else if (in_size) {
 171         req->mode = SCSI_XFER_FROM_DEV;
 172     }
 173
 174     return 0;
 175 }
 176
 177 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 178 {
 179     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 180     VirtIOSCSIReq *req;
 181
 182     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 183     if (!req) {
 184         return NULL;
 185     }
 186     virtio_scsi_init_req(s, vq, req);
 187     return req;
 188 }
 189
 190 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 191 {
 192     VirtIOSCSIReq *req = sreq->hba_private;
 193     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 194     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 195     uint32_t n = virtio_get_queue_index(req->vq) - VIRTIO_SCSI_VQ_NUM_FIXED;
 196
 197     assert(n < vs->conf.num_queues);
 198     qemu_put_be32s(f, &n);
 199     qemu_put_virtqueue_element(vdev, f, &req->elem);
 200 }
 201
 202 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 203 {
 204     SCSIBus *bus = sreq->bus;
 205     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 206     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 207     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 208     VirtIOSCSIReq *req;
 209     uint32_t n;
 210
 211     qemu_get_be32s(f, &n);
 212     assert(n < vs->conf.num_queues);
 213     req = qemu_get_virtqueue_element(vdev, f,
 214                                      sizeof(VirtIOSCSIReq) + vs->cdb_size);
 215     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 216
 217     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 218                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 219         error_report("invalid SCSI request migration data");
 220         exit(1);
 221     }
 222
 223     scsi_req_ref(sreq);
 224     req->sreq = sreq;
 225     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 226         assert(req->sreq->cmd.mode == req->mode);
 227     }
 228     return req;
 229 }
 230
 231 typedef struct {
 232     Notifier        notifier;
 233     VirtIOSCSIReq  *tmf_req;
 234 } VirtIOSCSICancelNotifier;
 235
 236 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 237 {
 238     VirtIOSCSICancelNotifier *n = container_of(notifier,
 239                                                VirtIOSCSICancelNotifier,
 240                                                notifier);
 241
 242     if (--n->tmf_req->remaining == 0) {
 243         VirtIOSCSIReq *req = n->tmf_req;
 244
 245         trace_virtio_scsi_tmf_resp(virtio_scsi_get_lun(req->req.tmf.lun),
 246                                    req->req.tmf.tag, req->resp.tmf.response);
 247         virtio_scsi_complete_req(req);
 248     }
 249     g_free(n);
 250 }
 251
 252 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
 253 {
 254     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
 255         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 256     }
 257 }
 258
 259 /* Return 0 if the request is ready to be completed and return to guest;
 260  * -EINPROGRESS if the request is submitted and will be completed later, in the
 261  *  case of async cancellation. */
 262 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 263 {
 264     SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun);
 265     SCSIRequest *r, *next;
 266     BusChild *kid;
 267     int target;
 268     int ret = 0;
 269
 270     virtio_scsi_ctx_check(s, d);
 271     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 272     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 273
 274     /*
 275      * req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
 276      * to avoid compiler errors.
 277      */
 278     req->req.tmf.subtype =
 279         virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
 280
 281     trace_virtio_scsi_tmf_req(virtio_scsi_get_lun(req->req.tmf.lun),
 282                               req->req.tmf.tag, req->req.tmf.subtype);
 283
 284     switch (req->req.tmf.subtype) {
 285     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 286     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 287         if (!d) {
 288             goto fail;
 289         }
 290         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 291             goto incorrect_lun;
 292         }
 293         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 294             VirtIOSCSIReq *cmd_req = r->hba_private;
 295             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 296                 break;
 297             }
 298         }
 299         if (r) {
 300             /*
 301              * Assert that the request has not been completed yet, we
 302              * check for it in the loop above.
 303              */
 304             assert(r->hba_private);
 305             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 306                 /* "If the specified command is present in the task set, then
 307                  * return a service response set to FUNCTION SUCCEEDED".
 308                  */
 309                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 310             } else {
 311                 VirtIOSCSICancelNotifier *notifier;
 312
 313                 req->remaining = 1;
 314                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 315                 notifier->tmf_req = req;
 316                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 317                 scsi_req_cancel_async(r, &notifier->notifier);
 318                 ret = -EINPROGRESS;
 319             }
 320         }
 321         break;
 322
 323     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 324         if (!d) {
 325             goto fail;
 326         }
 327         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 328             goto incorrect_lun;
 329         }
 330         s->resetting++;
 331         qdev_reset_all(&d->qdev);
 332         s->resetting--;
 333         break;
 334
 335     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 336     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 337     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 338         if (!d) {
 339             goto fail;
 340         }
 341         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 342             goto incorrect_lun;
 343         }
 344
 345         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 346          * This way, if the bus starts calling back to the notifiers
 347          * even before we finish the loop, virtio_scsi_cancel_notify
 348          * will not complete the TMF too early.
 349          */
 350         req->remaining = 1;
 351         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 352             if (r->hba_private) {
 353                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 354                     /* "If there is any command present in the task set, then
 355                      * return a service response set to FUNCTION SUCCEEDED".
 356                      */
 357                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 358                     break;
 359                 } else {
 360                     VirtIOSCSICancelNotifier *notifier;
 361
 362                     req->remaining++;
 363                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 364                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 365                     notifier->tmf_req = req;
 366                     scsi_req_cancel_async(r, &notifier->notifier);
 367                 }
 368             }
 369         }
 370         if (--req->remaining > 0) {
 371             ret = -EINPROGRESS;
 372         }
 373         break;
 374
 375     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 376         target = req->req.tmf.lun[1];
 377         s->resetting++;
 378
 379         rcu_read_lock();
 380         QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
 381             SCSIDevice *d1 = SCSI_DEVICE(kid->child);
 382             if (d1->channel == 0 && d1->id == target) {
 383                 qdev_reset_all(&d1->qdev);
 384             }
 385         }
 386         rcu_read_unlock();
 387
 388         s->resetting--;
 389         break;
 390
 391     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 392     default:
 393         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 394         break;
 395     }
 396
 397     object_unref(OBJECT(d));
 398     return ret;
 399
 400 incorrect_lun:
 401     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 402     object_unref(OBJECT(d));
 403     return ret;
 404
 405 fail:
 406     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 407     object_unref(OBJECT(d));
 408     return ret;
 409 }
 410
 411 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 412 {
 413     VirtIODevice *vdev = (VirtIODevice *)s;
 414     uint32_t type;
 415     int r = 0;
 416
 417     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 418                 &type, sizeof(type)) < sizeof(type)) {
 419         virtio_scsi_bad_req(req);
 420         return;
 421     }
 422
 423     virtio_tswap32s(vdev, &type);
 424     if (type == VIRTIO_SCSI_T_TMF) {
 425         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 426                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 427             virtio_scsi_bad_req(req);
 428             return;
 429         } else {
 430             r = virtio_scsi_do_tmf(s, req);
 431         }
 432
 433     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 434                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 435         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 436                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 437             virtio_scsi_bad_req(req);
 438             return;
 439         } else {
 440             req->req.an.event_requested =
 441                 virtio_tswap32(VIRTIO_DEVICE(s), req->req.an.event_requested);
 442             trace_virtio_scsi_an_req(virtio_scsi_get_lun(req->req.an.lun),
 443                                      req->req.an.event_requested);
 444             req->resp.an.event_actual = 0;
 445             req->resp.an.response = VIRTIO_SCSI_S_OK;
 446         }
 447     }
 448     if (r == 0) {
 449         if (type == VIRTIO_SCSI_T_TMF)
 450             trace_virtio_scsi_tmf_resp(virtio_scsi_get_lun(req->req.tmf.lun),
 451                                        req->req.tmf.tag,
 452                                        req->resp.tmf.response);
 453         else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 454                  type == VIRTIO_SCSI_T_AN_SUBSCRIBE)
 455             trace_virtio_scsi_an_resp(virtio_scsi_get_lun(req->req.an.lun),
 456                                       req->resp.an.response);
 457         virtio_scsi_complete_req(req);
 458     } else {
 459         assert(r == -EINPROGRESS);
 460     }
 461 }
 462
 463 bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 464 {
 465     VirtIOSCSIReq *req;
 466     bool progress = false;
 467
 468     while ((req = virtio_scsi_pop_req(s, vq))) {
 469         progress = true;
 470         virtio_scsi_handle_ctrl_req(s, req);
 471     }
 472     return progress;
 473 }
 474
 475 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 476 {
 477     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 478
 479     if (s->ctx) {
 480         virtio_device_start_ioeventfd(vdev);
 481         if (!s->dataplane_fenced) {
 482             return;
 483         }
 484     }
 485     virtio_scsi_acquire(s);
 486     virtio_scsi_handle_ctrl_vq(s, vq);
 487     virtio_scsi_release(s);
 488 }
 489
 490 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 491 {
 492     trace_virtio_scsi_cmd_resp(virtio_scsi_get_lun(req->req.cmd.lun),
 493                                req->req.cmd.tag,
 494                                req->resp.cmd.response,
 495                                req->resp.cmd.status);
 496     /* Sense data is not in req->resp and is copied separately
 497      * in virtio_scsi_command_complete.
 498      */
 499     req->resp_size = sizeof(VirtIOSCSICmdResp);
 500     virtio_scsi_complete_req(req);
 501 }
 502
 503 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 504                                          size_t resid)
 505 {
 506     VirtIOSCSIReq *req = r->hba_private;
 507     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 508     uint32_t sense_len;
 509     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 510
 511     if (r->io_canceled) {
 512         return;
 513     }
 514
 515     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 516     req->resp.cmd.status = status;
 517     if (req->resp.cmd.status == GOOD) {
 518         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 519     } else {
 520         req->resp.cmd.resid = 0;
 521         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 522         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 523         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 524                             sense, sense_len);
 525         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 526     }
 527     virtio_scsi_complete_cmd_req(req);
 528 }
 529
 530 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 531                                  uint8_t *buf, void *hba_private)
 532 {
 533     VirtIOSCSIReq *req = hba_private;
 534
 535     if (cmd->len == 0) {
 536         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 537         memcpy(cmd->buf, buf, cmd->len);
 538     }
 539
 540     /* Extract the direction and mode directly from the request, for
 541      * host device passthrough.
 542      */
 543     cmd->xfer = req->qsgl.size;
 544     cmd->mode = req->mode;
 545     return 0;
 546 }
 547
 548 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 549 {
 550     VirtIOSCSIReq *req = r->hba_private;
 551
 552     return &req->qsgl;
 553 }
 554
 555 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 556 {
 557     VirtIOSCSIReq *req = r->hba_private;
 558
 559     if (!req) {
 560         return;
 561     }
 562     if (req->dev->resetting) {
 563         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 564     } else {
 565         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 566     }
 567     virtio_scsi_complete_cmd_req(req);
 568 }
 569
 570 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 571 {
 572     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 573     virtio_scsi_complete_cmd_req(req);
 574 }
 575
 576 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 577 {
 578     VirtIOSCSICommon *vs = &s->parent_obj;
 579     SCSIDevice *d;
 580     int rc;
 581
 582     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 583                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 584     if (rc < 0) {
 585         if (rc == -ENOTSUP) {
 586             virtio_scsi_fail_cmd_req(req);
 587             return -ENOTSUP;
 588         } else {
 589             virtio_scsi_bad_req(req);
 590             return -EINVAL;
 591         }
 592     }
 593     trace_virtio_scsi_cmd_req(virtio_scsi_get_lun(req->req.cmd.lun),
 594                               req->req.cmd.tag, req->req.cmd.cdb[0]);
 595
 596     d = virtio_scsi_device_get(s, req->req.cmd.lun);
 597     if (!d) {
 598         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 599         virtio_scsi_complete_cmd_req(req);
 600         return -ENOENT;
 601     }
 602     virtio_scsi_ctx_check(s, d);
 603     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 604                              virtio_scsi_get_lun(req->req.cmd.lun),
 605                              req->req.cmd.cdb, req);
 606
 607     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 608         && (req->sreq->cmd.mode != req->mode ||
 609             req->sreq->cmd.xfer > req->qsgl.size)) {
 610         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 611         virtio_scsi_complete_cmd_req(req);
 612         object_unref(OBJECT(d));
 613         return -ENOBUFS;
 614     }
 615     scsi_req_ref(req->sreq);
 616     blk_io_plug(d->conf.blk);
 617     object_unref(OBJECT(d));
 618     return 0;
 619 }
 620
 621 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 622 {
 623     SCSIRequest *sreq = req->sreq;
 624     if (scsi_req_enqueue(sreq)) {
 625         scsi_req_continue(sreq);
 626     }
 627     blk_io_unplug(sreq->dev->conf.blk);
 628     scsi_req_unref(sreq);
 629 }
 630
 631 bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 632 {
 633     VirtIOSCSIReq *req, *next;
 634     int ret = 0;
 635     bool suppress_notifications = virtio_queue_get_notification(vq);
 636     bool progress = false;
 637
 638     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 639
 640     do {
 641         if (suppress_notifications) {
 642             virtio_queue_set_notification(vq, 0);
 643         }
 644
 645         while ((req = virtio_scsi_pop_req(s, vq))) {
 646             progress = true;
 647             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
 648             if (!ret) {
 649                 QTAILQ_INSERT_TAIL(&reqs, req, next);
 650             } else if (ret == -EINVAL) {
 651                 /* The device is broken and shouldn't process any request */
 652                 while (!QTAILQ_EMPTY(&reqs)) {
 653                     req = QTAILQ_FIRST(&reqs);
 654                     QTAILQ_REMOVE(&reqs, req, next);
 655                     blk_io_unplug(req->sreq->dev->conf.blk);
 656                     scsi_req_unref(req->sreq);
 657                     virtqueue_detach_element(req->vq, &req->elem, 0);
 658                     virtio_scsi_free_req(req);
 659                 }
 660             }
 661         }
 662
 663         if (suppress_notifications) {
 664             virtio_queue_set_notification(vq, 1);
 665         }
 666     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 667
 668     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 669         virtio_scsi_handle_cmd_req_submit(s, req);
 670     }
 671     return progress;
 672 }
 673
 674 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 675 {
 676     /* use non-QOM casts in the data path */
 677     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 678
 679     if (s->ctx) {
 680         virtio_device_start_ioeventfd(vdev);
 681         if (!s->dataplane_fenced) {
 682             return;
 683         }
 684     }
 685     virtio_scsi_acquire(s);
 686     virtio_scsi_handle_cmd_vq(s, vq);
 687     virtio_scsi_release(s);
 688 }
 689
 690 static void virtio_scsi_get_config(VirtIODevice *vdev,
 691                                    uint8_t *config)
 692 {
 693     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 694     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 695
 696     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 697     virtio_stl_p(vdev, &scsiconf->seg_max,
 698                  s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
 699     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 700     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 701     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 702     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 703     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 704     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 705     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 706     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 707 }
 708
 709 static void virtio_scsi_set_config(VirtIODevice *vdev,
 710                                    const uint8_t *config)
 711 {
 712     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 713     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 714
 715     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 716         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 717         virtio_error(vdev,
 718                      "bad data written to virtio-scsi configuration space");
 719         return;
 720     }
 721
 722     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 723     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 724 }
 725
 726 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 727                                          uint64_t requested_features,
 728                                          Error **errp)
 729 {
 730     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 731
 732     /* Firstly sync all virtio-scsi possible supported features */
 733     requested_features |= s->host_features;
 734     return requested_features;
 735 }
 736
 737 static void virtio_scsi_reset(VirtIODevice *vdev)
 738 {
 739     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 740     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 741
 742     assert(!s->dataplane_started);
 743     s->resetting++;
 744     qbus_reset_all(BUS(&s->bus));
 745     s->resetting--;
 746
 747     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 748     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 749     s->events_dropped = false;
 750 }
 751
 752 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 753                             uint32_t event, uint32_t reason)
 754 {
 755     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 756     VirtIOSCSIReq *req;
 757     VirtIOSCSIEvent *evt;
 758     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 759
 760     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 761         return;
 762     }
 763
 764     req = virtio_scsi_pop_req(s, vs->event_vq);
 765     if (!req) {
 766         s->events_dropped = true;
 767         return;
 768     }
 769
 770     if (s->events_dropped) {
 771         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 772         s->events_dropped = false;
 773     }
 774
 775     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 776         virtio_scsi_bad_req(req);
 777         return;
 778     }
 779
 780     evt = &req->resp.event;
 781     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 782     evt->event = virtio_tswap32(vdev, event);
 783     evt->reason = virtio_tswap32(vdev, reason);
 784     if (!dev) {
 785         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 786     } else {
 787         evt->lun[0] = 1;
 788         evt->lun[1] = dev->id;
 789
 790         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 791         if (dev->lun >= 256) {
 792             evt->lun[2] = (dev->lun >> 8) | 0x40;
 793         }
 794         evt->lun[3] = dev->lun & 0xFF;
 795     }
 796     trace_virtio_scsi_event(virtio_scsi_get_lun(evt->lun), event, reason);
 797
 798     virtio_scsi_complete_req(req);
 799 }
 800
 801 bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 802 {
 803     if (s->events_dropped) {
 804         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 805         return true;
 806     }
 807     return false;
 808 }
 809
 810 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 811 {
 812     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 813
 814     if (s->ctx) {
 815         virtio_device_start_ioeventfd(vdev);
 816         if (!s->dataplane_fenced) {
 817             return;
 818         }
 819     }
 820     virtio_scsi_acquire(s);
 821     virtio_scsi_handle_event_vq(s, vq);
 822     virtio_scsi_release(s);
 823 }
 824
 825 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 826 {
 827     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 828     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 829
 830     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 831         dev->type != TYPE_ROM) {
 832         virtio_scsi_acquire(s);
 833         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 834                                sense.asc | (sense.ascq << 8));
 835         virtio_scsi_release(s);
 836     }
 837 }
 838
 839 static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
 840                                     DeviceState *dev, Error **errp)
 841 {
 842     SCSIDevice *sd = SCSI_DEVICE(dev);
 843     sd->hba_supports_iothread = true;
 844 }
 845
 846 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 847                                 Error **errp)
 848 {
 849     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 850     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 851     SCSIDevice *sd = SCSI_DEVICE(dev);
 852     AioContext *old_context;
 853     int ret;
 854
 855     if (s->ctx && !s->dataplane_fenced) {
 856         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 857             return;
 858         }
 859         old_context = blk_get_aio_context(sd->conf.blk);
 860         aio_context_acquire(old_context);
 861         ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
 862         aio_context_release(old_context);
 863         if (ret < 0) {
 864             return;
 865         }
 866     }
 867
 868     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 869         virtio_scsi_acquire(s);
 870         virtio_scsi_push_event(s, sd,
 871                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 872                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 873         virtio_scsi_release(s);
 874     }
 875 }
 876
 877 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 878                                   Error **errp)
 879 {
 880     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 881     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 882     SCSIDevice *sd = SCSI_DEVICE(dev);
 883     AioContext *ctx = s->ctx ?: qemu_get_aio_context();
 884
 885     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 886         virtio_scsi_acquire(s);
 887         virtio_scsi_push_event(s, sd,
 888                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 889                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 890         virtio_scsi_release(s);
 891     }
 892
 893     aio_disable_external(ctx);
 894     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 895     aio_enable_external(ctx);
 896
 897     if (s->ctx) {
 898         virtio_scsi_acquire(s);
 899         /* If other users keep the BlockBackend in the iothread, that's ok */
 900         blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
 901         virtio_scsi_release(s);
 902     }
 903 }
 904
 905 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 906     .tcq = true,
 907     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 908     .max_target = VIRTIO_SCSI_MAX_TARGET,
 909     .max_lun = VIRTIO_SCSI_MAX_LUN,
 910
 911     .complete = virtio_scsi_command_complete,
 912     .cancel = virtio_scsi_request_cancelled,
 913     .change = virtio_scsi_change,
 914     .parse_cdb = virtio_scsi_parse_cdb,
 915     .get_sg_list = virtio_scsi_get_sg_list,
 916     .save_request = virtio_scsi_save_request,
 917     .load_request = virtio_scsi_load_request,
 918 };
 919
 920 void virtio_scsi_common_realize(DeviceState *dev,
 921                                 VirtIOHandleOutput ctrl,
 922                                 VirtIOHandleOutput evt,
 923                                 VirtIOHandleOutput cmd,
 924                                 Error **errp)
 925 {
 926     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 927     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 928     int i;
 929
 930     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 931                 sizeof(VirtIOSCSIConfig));
 932
 933     if (s->conf.num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
 934         s->conf.num_queues = 1;
 935     }
 936     if (s->conf.num_queues == 0 ||
 937             s->conf.num_queues > VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED) {
 938         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 939                          "must be a positive integer less than %d.",
 940                    s->conf.num_queues,
 941                    VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED);
 942         virtio_cleanup(vdev);
 943         return;
 944     }
 945     if (s->conf.virtqueue_size <= 2) {
 946         error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
 947                    "must be > 2", s->conf.virtqueue_size);
 948         return;
 949     }
 950     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 951     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 952     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 953
 954     s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
 955     s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
 956     for (i = 0; i < s->conf.num_queues; i++) {
 957         s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
 958     }
 959 }
 960
 961 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 962 {
 963     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 964     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 965     Error *err = NULL;
 966
 967     virtio_scsi_common_realize(dev,
 968                                virtio_scsi_handle_ctrl,
 969                                virtio_scsi_handle_event,
 970                                virtio_scsi_handle_cmd,
 971                                &err);
 972     if (err != NULL) {
 973         error_propagate(errp, err);
 974         return;
 975     }
 976
 977     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 978                  &virtio_scsi_scsi_info, vdev->bus_name);
 979     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 980     qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev));
 981
 982     virtio_scsi_dataplane_setup(s, errp);
 983 }
 984
 985 void virtio_scsi_common_unrealize(DeviceState *dev)
 986 {
 987     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 988     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 989     int i;
 990
 991     virtio_delete_queue(vs->ctrl_vq);
 992     virtio_delete_queue(vs->event_vq);
 993     for (i = 0; i < vs->conf.num_queues; i++) {
 994         virtio_delete_queue(vs->cmd_vqs[i]);
 995     }
 996     g_free(vs->cmd_vqs);
 997     virtio_cleanup(vdev);
 998 }
 999
1000 static void virtio_scsi_device_unrealize(DeviceState *dev)
1001 {
1002     VirtIOSCSI *s = VIRTIO_SCSI(dev);
1003
1004     qbus_set_hotplug_handler(BUS(&s->bus), NULL);
1005     virtio_scsi_common_unrealize(dev);
1006 }
1007
1008 static Property virtio_scsi_properties[] = {
1009     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues,
1010                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
1011     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
1012                                          parent_obj.conf.virtqueue_size, 256),
1013     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
1014                       parent_obj.conf.seg_max_adjust, true),
1015     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
1016                                                   0xFFFF),
1017     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
1018                                                   128),
1019     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
1020                                            VIRTIO_SCSI_F_HOTPLUG, true),
1021     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
1022                                                 VIRTIO_SCSI_F_CHANGE, true),
1023     DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
1024                      TYPE_IOTHREAD, IOThread *),
1025     DEFINE_PROP_END_OF_LIST(),
1026 };
1027
1028 static const VMStateDescription vmstate_virtio_scsi = {
1029     .name = "virtio-scsi",
1030     .minimum_version_id = 1,
1031     .version_id = 1,
1032     .fields = (VMStateField[]) {
1033         VMSTATE_VIRTIO_DEVICE,
1034         VMSTATE_END_OF_LIST()
1035     },
1036 };
1037
1038 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
1039 {
1040     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1041     DeviceClass *dc = DEVICE_CLASS(klass);
1042
1043     vdc->get_config = virtio_scsi_get_config;
1044     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1045 }
1046
1047 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
1048 {
1049     DeviceClass *dc = DEVICE_CLASS(klass);
1050     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1051     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1052
1053     device_class_set_props(dc, virtio_scsi_properties);
1054     dc->vmsd = &vmstate_virtio_scsi;
1055     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1056     vdc->realize = virtio_scsi_device_realize;
1057     vdc->unrealize = virtio_scsi_device_unrealize;
1058     vdc->set_config = virtio_scsi_set_config;
1059     vdc->get_features = virtio_scsi_get_features;
1060     vdc->reset = virtio_scsi_reset;
1061     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
1062     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
1063     hc->pre_plug = virtio_scsi_pre_hotplug;
1064     hc->plug = virtio_scsi_hotplug;
1065     hc->unplug = virtio_scsi_hotunplug;
1066 }
1067
1068 static const TypeInfo virtio_scsi_common_info = {
1069     .name = TYPE_VIRTIO_SCSI_COMMON,
1070     .parent = TYPE_VIRTIO_DEVICE,
1071     .instance_size = sizeof(VirtIOSCSICommon),
1072     .abstract = true,
1073     .class_init = virtio_scsi_common_class_init,
1074 };
1075
1076 static const TypeInfo virtio_scsi_info = {
1077     .name = TYPE_VIRTIO_SCSI,
1078     .parent = TYPE_VIRTIO_SCSI_COMMON,
1079     .instance_size = sizeof(VirtIOSCSI),
1080     .class_init = virtio_scsi_class_init,
1081     .interfaces = (InterfaceInfo[]) {
1082         { TYPE_HOTPLUG_HANDLER },
1083         { }
1084     }
1085 };
1086
1087 static void virtio_register_types(void)
1088 {
1089     type_register_static(&virtio_scsi_common_info);
1090     type_register_static(&virtio_scsi_info);
1091 }
1092
1093 type_init(virtio_register_types)