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 "qemu/error-report.h"
  21 #include "qemu/iov.h"
  22 #include "sysemu/block-backend.h"
  23 #include <hw/scsi/scsi.h>
  24 #include <block/scsi.h>
  25 #include <hw/virtio/virtio-bus.h>
  26 #include "hw/virtio/virtio-access.h"
  27
  28 static inline int virtio_scsi_get_lun(uint8_t *lun)
  29 {
  30     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
  31 }
  32
  33 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
  34 {
  35     if (lun[0] != 1) {
  36         return NULL;
  37     }
  38     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
  39         return NULL;
  40     }
  41     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
  42 }
  43
  44 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
  45 {
  46     const size_t zero_skip =
  47         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
  48
  49     req->vq = vq;
  50     req->dev = s;
  51     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, &address_space_memory);
  52     qemu_iovec_init(&req->resp_iov, 1);
  53     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
  54 }
  55
  56 void virtio_scsi_free_req(VirtIOSCSIReq *req)
  57 {
  58     qemu_iovec_destroy(&req->resp_iov);
  59     qemu_sglist_destroy(&req->qsgl);
  60     g_free(req);
  61 }
  62
  63 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
  64 {
  65     VirtIOSCSI *s = req->dev;
  66     VirtQueue *vq = req->vq;
  67     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  68
  69     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
  70     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
  71     if (s->dataplane_started && !s->dataplane_fenced) {
  72         virtio_scsi_dataplane_notify(vdev, req);
  73     } else {
  74         virtio_notify(vdev, vq);
  75     }
  76
  77     if (req->sreq) {
  78         req->sreq->hba_private = NULL;
  79         scsi_req_unref(req->sreq);
  80     }
  81     virtio_scsi_free_req(req);
  82 }
  83
  84 static void virtio_scsi_bad_req(void)
  85 {
  86     error_report("wrong size for virtio-scsi headers");
  87     exit(1);
  88 }
  89
  90 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
  91                               hwaddr *addr, int num, size_t skip)
  92 {
  93     QEMUSGList *qsgl = &req->qsgl;
  94     size_t copied = 0;
  95
  96     while (num) {
  97         if (skip >= iov->iov_len) {
  98             skip -= iov->iov_len;
  99         } else {
 100             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
 101             copied += iov->iov_len - skip;
 102             skip = 0;
 103         }
 104         iov++;
 105         addr++;
 106         num--;
 107     }
 108
 109     assert(skip == 0);
 110     return copied;
 111 }
 112
 113 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
 114                                  unsigned req_size, unsigned resp_size)
 115 {
 116     VirtIODevice *vdev = (VirtIODevice *) req->dev;
 117     size_t in_size, out_size;
 118
 119     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 120                    &req->req, req_size) < req_size) {
 121         return -EINVAL;
 122     }
 123
 124     if (qemu_iovec_concat_iov(&req->resp_iov,
 125                               req->elem.in_sg, req->elem.in_num, 0,
 126                               resp_size) < resp_size) {
 127         return -EINVAL;
 128     }
 129
 130     req->resp_size = resp_size;
 131
 132     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
 133      * As a workaround, always consider the first buffer as the virtio-scsi
 134      * request/response, making the payload start at the second element
 135      * of the iovec.
 136      *
 137      * The actual length of the response header, stored in req->resp_size,
 138      * does not change.
 139      *
 140      * TODO: always disable this workaround for virtio 1.0 devices.
 141      */
 142     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
 143         if (req->elem.out_num) {
 144             req_size = req->elem.out_sg[0].iov_len;
 145         }
 146         if (req->elem.in_num) {
 147             resp_size = req->elem.in_sg[0].iov_len;
 148         }
 149     }
 150
 151     out_size = qemu_sgl_concat(req, req->elem.out_sg,
 152                                &req->elem.out_addr[0], req->elem.out_num,
 153                                req_size);
 154     in_size = qemu_sgl_concat(req, req->elem.in_sg,
 155                               &req->elem.in_addr[0], req->elem.in_num,
 156                               resp_size);
 157
 158     if (out_size && in_size) {
 159         return -ENOTSUP;
 160     }
 161
 162     if (out_size) {
 163         req->mode = SCSI_XFER_TO_DEV;
 164     } else if (in_size) {
 165         req->mode = SCSI_XFER_FROM_DEV;
 166     }
 167
 168     return 0;
 169 }
 170
 171 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 172 {
 173     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
 174     VirtIOSCSIReq *req;
 175
 176     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 177     if (!req) {
 178         return NULL;
 179     }
 180     virtio_scsi_init_req(s, vq, req);
 181     return req;
 182 }
 183
 184 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 185 {
 186     VirtIOSCSIReq *req = sreq->hba_private;
 187     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
 188     uint32_t n = virtio_get_queue_index(req->vq) - 2;
 189
 190     assert(n < vs->conf.num_queues);
 191     qemu_put_be32s(f, &n);
 192     qemu_put_virtqueue_element(f, &req->elem);
 193 }
 194
 195 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 196 {
 197     SCSIBus *bus = sreq->bus;
 198     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 199     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 200     VirtIOSCSIReq *req;
 201     uint32_t n;
 202
 203     qemu_get_be32s(f, &n);
 204     assert(n < vs->conf.num_queues);
 205     req = qemu_get_virtqueue_element(f, sizeof(VirtIOSCSIReq) + vs->cdb_size);
 206     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
 207
 208     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 209                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
 210         error_report("invalid SCSI request migration data");
 211         exit(1);
 212     }
 213
 214     scsi_req_ref(sreq);
 215     req->sreq = sreq;
 216     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 217         assert(req->sreq->cmd.mode == req->mode);
 218     }
 219     return req;
 220 }
 221
 222 typedef struct {
 223     Notifier        notifier;
 224     VirtIOSCSIReq  *tmf_req;
 225 } VirtIOSCSICancelNotifier;
 226
 227 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
 228 {
 229     VirtIOSCSICancelNotifier *n = container_of(notifier,
 230                                                VirtIOSCSICancelNotifier,
 231                                                notifier);
 232
 233     if (--n->tmf_req->remaining == 0) {
 234         virtio_scsi_complete_req(n->tmf_req);
 235     }
 236     g_free(n);
 237 }
 238
 239 /* Return 0 if the request is ready to be completed and return to guest;
 240  * -EINPROGRESS if the request is submitted and will be completed later, in the
 241  *  case of async cancellation. */
 242 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 243 {
 244     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
 245     SCSIRequest *r, *next;
 246     BusChild *kid;
 247     int target;
 248     int ret = 0;
 249
 250     if (s->dataplane_started && d) {
 251         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 252     }
 253     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 254     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
 255
 256     virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
 257     switch (req->req.tmf.subtype) {
 258     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 259     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 260         if (!d) {
 261             goto fail;
 262         }
 263         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 264             goto incorrect_lun;
 265         }
 266         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 267             VirtIOSCSIReq *cmd_req = r->hba_private;
 268             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
 269                 break;
 270             }
 271         }
 272         if (r) {
 273             /*
 274              * Assert that the request has not been completed yet, we
 275              * check for it in the loop above.
 276              */
 277             assert(r->hba_private);
 278             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 279                 /* "If the specified command is present in the task set, then
 280                  * return a service response set to FUNCTION SUCCEEDED".
 281                  */
 282                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 283             } else {
 284                 VirtIOSCSICancelNotifier *notifier;
 285
 286                 req->remaining = 1;
 287                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
 288                 notifier->tmf_req = req;
 289                 notifier->notifier.notify = virtio_scsi_cancel_notify;
 290                 scsi_req_cancel_async(r, &notifier->notifier);
 291                 ret = -EINPROGRESS;
 292             }
 293         }
 294         break;
 295
 296     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 297         if (!d) {
 298             goto fail;
 299         }
 300         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 301             goto incorrect_lun;
 302         }
 303         s->resetting++;
 304         qdev_reset_all(&d->qdev);
 305         s->resetting--;
 306         break;
 307
 308     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 309     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 310     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 311         if (!d) {
 312             goto fail;
 313         }
 314         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
 315             goto incorrect_lun;
 316         }
 317
 318         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
 319          * This way, if the bus starts calling back to the notifiers
 320          * even before we finish the loop, virtio_scsi_cancel_notify
 321          * will not complete the TMF too early.
 322          */
 323         req->remaining = 1;
 324         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 325             if (r->hba_private) {
 326                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 327                     /* "If there is any command present in the task set, then
 328                      * return a service response set to FUNCTION SUCCEEDED".
 329                      */
 330                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 331                     break;
 332                 } else {
 333                     VirtIOSCSICancelNotifier *notifier;
 334
 335                     req->remaining++;
 336                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
 337                     notifier->notifier.notify = virtio_scsi_cancel_notify;
 338                     notifier->tmf_req = req;
 339                     scsi_req_cancel_async(r, &notifier->notifier);
 340                 }
 341             }
 342         }
 343         if (--req->remaining > 0) {
 344             ret = -EINPROGRESS;
 345         }
 346         break;
 347
 348     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 349         target = req->req.tmf.lun[1];
 350         s->resetting++;
 351         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 352              d = SCSI_DEVICE(kid->child);
 353              if (d->channel == 0 && d->id == target) {
 354                 qdev_reset_all(&d->qdev);
 355              }
 356         }
 357         s->resetting--;
 358         break;
 359
 360     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 361     default:
 362         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 363         break;
 364     }
 365
 366     return ret;
 367
 368 incorrect_lun:
 369     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
 370     return ret;
 371
 372 fail:
 373     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
 374     return ret;
 375 }
 376
 377 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
 378 {
 379     VirtIODevice *vdev = (VirtIODevice *)s;
 380     uint32_t type;
 381     int r = 0;
 382
 383     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
 384                 &type, sizeof(type)) < sizeof(type)) {
 385         virtio_scsi_bad_req();
 386         return;
 387     }
 388
 389     virtio_tswap32s(vdev, &type);
 390     if (type == VIRTIO_SCSI_T_TMF) {
 391         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
 392                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
 393             virtio_scsi_bad_req();
 394         } else {
 395             r = virtio_scsi_do_tmf(s, req);
 396         }
 397
 398     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
 399                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 400         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
 401                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
 402             virtio_scsi_bad_req();
 403         } else {
 404             req->resp.an.event_actual = 0;
 405             req->resp.an.response = VIRTIO_SCSI_S_OK;
 406         }
 407     }
 408     if (r == 0) {
 409         virtio_scsi_complete_req(req);
 410     } else {
 411         assert(r == -EINPROGRESS);
 412     }
 413 }
 414
 415 void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
 416 {
 417     VirtIOSCSIReq *req;
 418
 419     while ((req = virtio_scsi_pop_req(s, vq))) {
 420         virtio_scsi_handle_ctrl_req(s, req);
 421     }
 422 }
 423
 424 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 425 {
 426     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 427
 428     if (s->ctx) {
 429         virtio_scsi_dataplane_start(s);
 430         if (!s->dataplane_fenced) {
 431             return;
 432         }
 433     }
 434     virtio_scsi_handle_ctrl_vq(s, vq);
 435 }
 436
 437 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
 438 {
 439     /* Sense data is not in req->resp and is copied separately
 440      * in virtio_scsi_command_complete.
 441      */
 442     req->resp_size = sizeof(VirtIOSCSICmdResp);
 443     virtio_scsi_complete_req(req);
 444 }
 445
 446 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 447                                          size_t resid)
 448 {
 449     VirtIOSCSIReq *req = r->hba_private;
 450     uint8_t sense[SCSI_SENSE_BUF_SIZE];
 451     uint32_t sense_len;
 452     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
 453
 454     if (r->io_canceled) {
 455         return;
 456     }
 457
 458     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
 459     req->resp.cmd.status = status;
 460     if (req->resp.cmd.status == GOOD) {
 461         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
 462     } else {
 463         req->resp.cmd.resid = 0;
 464         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
 465         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
 466         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
 467                             sense, sense_len);
 468         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
 469     }
 470     virtio_scsi_complete_cmd_req(req);
 471 }
 472
 473 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
 474                                  uint8_t *buf, void *hba_private)
 475 {
 476     VirtIOSCSIReq *req = hba_private;
 477
 478     if (cmd->len == 0) {
 479         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
 480         memcpy(cmd->buf, buf, cmd->len);
 481     }
 482
 483     /* Extract the direction and mode directly from the request, for
 484      * host device passthrough.
 485      */
 486     cmd->xfer = req->qsgl.size;
 487     cmd->mode = req->mode;
 488     return 0;
 489 }
 490
 491 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 492 {
 493     VirtIOSCSIReq *req = r->hba_private;
 494
 495     return &req->qsgl;
 496 }
 497
 498 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 499 {
 500     VirtIOSCSIReq *req = r->hba_private;
 501
 502     if (!req) {
 503         return;
 504     }
 505     if (req->dev->resetting) {
 506         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
 507     } else {
 508         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
 509     }
 510     virtio_scsi_complete_cmd_req(req);
 511 }
 512
 513 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 514 {
 515     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
 516     virtio_scsi_complete_cmd_req(req);
 517 }
 518
 519 static bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
 520 {
 521     VirtIOSCSICommon *vs = &s->parent_obj;
 522     SCSIDevice *d;
 523     int rc;
 524
 525     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
 526                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
 527     if (rc < 0) {
 528         if (rc == -ENOTSUP) {
 529             virtio_scsi_fail_cmd_req(req);
 530         } else {
 531             virtio_scsi_bad_req();
 532         }
 533         return false;
 534     }
 535
 536     d = virtio_scsi_device_find(s, req->req.cmd.lun);
 537     if (!d) {
 538         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
 539         virtio_scsi_complete_cmd_req(req);
 540         return false;
 541     }
 542     if (s->dataplane_started) {
 543         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
 544     }
 545     req->sreq = scsi_req_new(d, req->req.cmd.tag,
 546                              virtio_scsi_get_lun(req->req.cmd.lun),
 547                              req->req.cmd.cdb, req);
 548
 549     if (req->sreq->cmd.mode != SCSI_XFER_NONE
 550         && (req->sreq->cmd.mode != req->mode ||
 551             req->sreq->cmd.xfer > req->qsgl.size)) {
 552         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
 553         virtio_scsi_complete_cmd_req(req);
 554         return false;
 555     }
 556     scsi_req_ref(req->sreq);
 557     blk_io_plug(d->conf.blk);
 558     return true;
 559 }
 560
 561 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
 562 {
 563     SCSIRequest *sreq = req->sreq;
 564     if (scsi_req_enqueue(sreq)) {
 565         scsi_req_continue(sreq);
 566     }
 567     blk_io_unplug(sreq->dev->conf.blk);
 568     scsi_req_unref(sreq);
 569 }
 570
 571 void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 572 {
 573     VirtIOSCSIReq *req, *next;
 574     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 575
 576     while ((req = virtio_scsi_pop_req(s, vq))) {
 577         if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
 578             QTAILQ_INSERT_TAIL(&reqs, req, next);
 579         }
 580     }
 581
 582     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
 583         virtio_scsi_handle_cmd_req_submit(s, req);
 584     }
 585 }
 586
 587 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 588 {
 589     /* use non-QOM casts in the data path */
 590     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 591
 592     if (s->ctx) {
 593         virtio_scsi_dataplane_start(s);
 594         if (!s->dataplane_fenced) {
 595             return;
 596         }
 597     }
 598     virtio_scsi_handle_cmd_vq(s, vq);
 599 }
 600
 601 static void virtio_scsi_get_config(VirtIODevice *vdev,
 602                                    uint8_t *config)
 603 {
 604     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 605     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 606
 607     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
 608     virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
 609     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
 610     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
 611     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 612     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
 613     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
 614     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 615     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 616     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 617 }
 618
 619 static void virtio_scsi_set_config(VirtIODevice *vdev,
 620                                    const uint8_t *config)
 621 {
 622     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 623     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 624
 625     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
 626         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
 627         error_report("bad data written to virtio-scsi configuration space");
 628         exit(1);
 629     }
 630
 631     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
 632     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
 633 }
 634
 635 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
 636                                          uint64_t requested_features,
 637                                          Error **errp)
 638 {
 639     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 640
 641     /* Firstly sync all virtio-scsi possible supported features */
 642     requested_features |= s->host_features;
 643     return requested_features;
 644 }
 645
 646 static void virtio_scsi_reset(VirtIODevice *vdev)
 647 {
 648     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 649     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 650
 651     if (s->ctx) {
 652         virtio_scsi_dataplane_stop(s);
 653     }
 654     s->resetting++;
 655     qbus_reset_all(&s->bus.qbus);
 656     s->resetting--;
 657
 658     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 659     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 660     s->events_dropped = false;
 661 }
 662
 663 /* The device does not have anything to save beyond the virtio data.
 664  * Request data is saved with callbacks from SCSI devices.
 665  */
 666 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 667 {
 668     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 669     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 670
 671     if (s->dataplane_started) {
 672         virtio_scsi_dataplane_stop(s);
 673     }
 674     virtio_save(vdev, f);
 675 }
 676
 677 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 678 {
 679     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 680     int ret;
 681
 682     ret = virtio_load(vdev, f, version_id);
 683     if (ret) {
 684         return ret;
 685     }
 686     return 0;
 687 }
 688
 689 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 690                             uint32_t event, uint32_t reason)
 691 {
 692     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
 693     VirtIOSCSIReq *req;
 694     VirtIOSCSIEvent *evt;
 695     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 696
 697     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 698         return;
 699     }
 700
 701     if (s->dataplane_started) {
 702         assert(s->ctx);
 703         aio_context_acquire(s->ctx);
 704     }
 705
 706     req = virtio_scsi_pop_req(s, vs->event_vq);
 707     if (!req) {
 708         s->events_dropped = true;
 709         goto out;
 710     }
 711
 712     if (s->events_dropped) {
 713         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 714         s->events_dropped = false;
 715     }
 716
 717     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
 718         virtio_scsi_bad_req();
 719     }
 720
 721     evt = &req->resp.event;
 722     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 723     evt->event = virtio_tswap32(vdev, event);
 724     evt->reason = virtio_tswap32(vdev, reason);
 725     if (!dev) {
 726         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
 727     } else {
 728         evt->lun[0] = 1;
 729         evt->lun[1] = dev->id;
 730
 731         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 732         if (dev->lun >= 256) {
 733             evt->lun[2] = (dev->lun >> 8) | 0x40;
 734         }
 735         evt->lun[3] = dev->lun & 0xFF;
 736     }
 737     virtio_scsi_complete_req(req);
 738 out:
 739     if (s->dataplane_started) {
 740         aio_context_release(s->ctx);
 741     }
 742 }
 743
 744 void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
 745 {
 746     if (s->events_dropped) {
 747         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 748     }
 749 }
 750
 751 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 752 {
 753     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 754
 755     if (s->ctx) {
 756         virtio_scsi_dataplane_start(s);
 757         if (!s->dataplane_fenced) {
 758             return;
 759         }
 760     }
 761     virtio_scsi_handle_event_vq(s, vq);
 762 }
 763
 764 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 765 {
 766     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 767     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 768
 769     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
 770         dev->type != TYPE_ROM) {
 771         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 772                                sense.asc | (sense.ascq << 8));
 773     }
 774 }
 775
 776 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 777                                 Error **errp)
 778 {
 779     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 780     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 781     SCSIDevice *sd = SCSI_DEVICE(dev);
 782
 783     if (s->ctx && !s->dataplane_fenced) {
 784         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
 785             return;
 786         }
 787         aio_context_acquire(s->ctx);
 788         blk_set_aio_context(sd->conf.blk, s->ctx);
 789         aio_context_release(s->ctx);
 790
 791     }
 792
 793     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 794         virtio_scsi_push_event(s, sd,
 795                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 796                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 797     }
 798 }
 799
 800 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
 801                                   Error **errp)
 802 {
 803     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
 804     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 805     SCSIDevice *sd = SCSI_DEVICE(dev);
 806
 807     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
 808         virtio_scsi_push_event(s, sd,
 809                                VIRTIO_SCSI_T_TRANSPORT_RESET,
 810                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 811     }
 812
 813     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
 814 }
 815
 816 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 817     .tcq = true,
 818     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 819     .max_target = VIRTIO_SCSI_MAX_TARGET,
 820     .max_lun = VIRTIO_SCSI_MAX_LUN,
 821
 822     .complete = virtio_scsi_command_complete,
 823     .cancel = virtio_scsi_request_cancelled,
 824     .change = virtio_scsi_change,
 825     .parse_cdb = virtio_scsi_parse_cdb,
 826     .get_sg_list = virtio_scsi_get_sg_list,
 827     .save_request = virtio_scsi_save_request,
 828     .load_request = virtio_scsi_load_request,
 829 };
 830
 831 void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
 832                                 HandleOutput ctrl, HandleOutput evt,
 833                                 HandleOutput cmd)
 834 {
 835     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 836     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 837     int i;
 838
 839     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
 840                 sizeof(VirtIOSCSIConfig));
 841
 842     if (s->conf.num_queues == 0 ||
 843             s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
 844         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
 845                          "must be a positive integer less than %d.",
 846                    s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
 847         virtio_cleanup(vdev);
 848         return;
 849     }
 850     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
 851     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
 852     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
 853
 854     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 855                                   ctrl);
 856     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 857                                    evt);
 858     for (i = 0; i < s->conf.num_queues; i++) {
 859         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
 860                                          cmd);
 861     }
 862
 863     if (s->conf.iothread) {
 864         virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
 865     }
 866 }
 867
 868 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 869 {
 870     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 871     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 872     static int virtio_scsi_id;
 873     Error *err = NULL;
 874
 875     virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
 876                                virtio_scsi_handle_event,
 877                                virtio_scsi_handle_cmd);
 878     if (err != NULL) {
 879         error_propagate(errp, err);
 880         return;
 881     }
 882
 883     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
 884                  &virtio_scsi_scsi_info, vdev->bus_name);
 885     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
 886     qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);
 887
 888     if (!dev->hotplugged) {
 889         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 890         if (err != NULL) {
 891             error_propagate(errp, err);
 892             return;
 893         }
 894     }
 895
 896     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 897                     virtio_scsi_save, virtio_scsi_load, s);
 898 }
 899
 900 static void virtio_scsi_instance_init(Object *obj)
 901 {
 902     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
 903
 904     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
 905                              (Object **)&vs->conf.iothread,
 906                              qdev_prop_allow_set_link_before_realize,
 907                              OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
 908 }
 909
 910 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 911 {
 912     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 913     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 914
 915     g_free(vs->cmd_vqs);
 916     virtio_cleanup(vdev);
 917 }
 918
 919 static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
 920 {
 921     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 922
 923     unregister_savevm(dev, "virtio-scsi", s);
 924     virtio_scsi_common_unrealize(dev, errp);
 925 }
 926
 927 static Property virtio_scsi_properties[] = {
 928     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
 929     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
 930                                                   0xFFFF),
 931     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
 932                                                   128),
 933     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
 934                                            VIRTIO_SCSI_F_HOTPLUG, true),
 935     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
 936                                                 VIRTIO_SCSI_F_CHANGE, true),
 937     DEFINE_PROP_END_OF_LIST(),
 938 };
 939
 940 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
 941 {
 942     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 943     DeviceClass *dc = DEVICE_CLASS(klass);
 944
 945     vdc->get_config = virtio_scsi_get_config;
 946     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 947 }
 948
 949 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 950 {
 951     DeviceClass *dc = DEVICE_CLASS(klass);
 952     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 953     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
 954
 955     dc->props = virtio_scsi_properties;
 956     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 957     vdc->realize = virtio_scsi_device_realize;
 958     vdc->unrealize = virtio_scsi_device_unrealize;
 959     vdc->set_config = virtio_scsi_set_config;
 960     vdc->get_features = virtio_scsi_get_features;
 961     vdc->reset = virtio_scsi_reset;
 962     hc->plug = virtio_scsi_hotplug;
 963     hc->unplug = virtio_scsi_hotunplug;
 964 }
 965
 966 static const TypeInfo virtio_scsi_common_info = {
 967     .name = TYPE_VIRTIO_SCSI_COMMON,
 968     .parent = TYPE_VIRTIO_DEVICE,
 969     .instance_size = sizeof(VirtIOSCSICommon),
 970     .abstract = true,
 971     .class_init = virtio_scsi_common_class_init,
 972 };
 973
 974 static const TypeInfo virtio_scsi_info = {
 975     .name = TYPE_VIRTIO_SCSI,
 976     .parent = TYPE_VIRTIO_SCSI_COMMON,
 977     .instance_size = sizeof(VirtIOSCSI),
 978     .instance_init = virtio_scsi_instance_init,
 979     .class_init = virtio_scsi_class_init,
 980     .interfaces = (InterfaceInfo[]) {
 981         { TYPE_HOTPLUG_HANDLER },
 982         { }
 983     }
 984 };
 985
 986 static void virtio_register_types(void)
 987 {
 988     type_register_static(&virtio_scsi_common_info);
 989     type_register_static(&virtio_scsi_info);
 990 }
 991
 992 type_init(virtio_register_types)