hw/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 "virtio-scsi.h"
  17 #include <hw/scsi.h>
  18 #include <hw/scsi-defs.h>
  19
  20 #define VIRTIO_SCSI_VQ_SIZE     128
  21 #define VIRTIO_SCSI_CDB_SIZE    32
  22 #define VIRTIO_SCSI_SENSE_SIZE  96
  23 #define VIRTIO_SCSI_MAX_CHANNEL 0
  24 #define VIRTIO_SCSI_MAX_TARGET  255
  25 #define VIRTIO_SCSI_MAX_LUN     16383
  26
  27 /* Response codes */
  28 #define VIRTIO_SCSI_S_OK                       0
  29 #define VIRTIO_SCSI_S_OVERRUN                  1
  30 #define VIRTIO_SCSI_S_ABORTED                  2
  31 #define VIRTIO_SCSI_S_BAD_TARGET               3
  32 #define VIRTIO_SCSI_S_RESET                    4
  33 #define VIRTIO_SCSI_S_BUSY                     5
  34 #define VIRTIO_SCSI_S_TRANSPORT_FAILURE        6
  35 #define VIRTIO_SCSI_S_TARGET_FAILURE           7
  36 #define VIRTIO_SCSI_S_NEXUS_FAILURE            8
  37 #define VIRTIO_SCSI_S_FAILURE                  9
  38 #define VIRTIO_SCSI_S_FUNCTION_SUCCEEDED       10
  39 #define VIRTIO_SCSI_S_FUNCTION_REJECTED        11
  40 #define VIRTIO_SCSI_S_INCORRECT_LUN            12
  41
  42 /* Controlq type codes.  */
  43 #define VIRTIO_SCSI_T_TMF                      0
  44 #define VIRTIO_SCSI_T_AN_QUERY                 1
  45 #define VIRTIO_SCSI_T_AN_SUBSCRIBE             2
  46
  47 /* Valid TMF subtypes.  */
  48 #define VIRTIO_SCSI_T_TMF_ABORT_TASK           0
  49 #define VIRTIO_SCSI_T_TMF_ABORT_TASK_SET       1
  50 #define VIRTIO_SCSI_T_TMF_CLEAR_ACA            2
  51 #define VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET       3
  52 #define VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET      4
  53 #define VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET   5
  54 #define VIRTIO_SCSI_T_TMF_QUERY_TASK           6
  55 #define VIRTIO_SCSI_T_TMF_QUERY_TASK_SET       7
  56
  57 /* Events.  */
  58 #define VIRTIO_SCSI_T_EVENTS_MISSED            0x80000000
  59 #define VIRTIO_SCSI_T_NO_EVENT                 0
  60 #define VIRTIO_SCSI_T_TRANSPORT_RESET          1
  61 #define VIRTIO_SCSI_T_ASYNC_NOTIFY             2
  62
  63 /* SCSI command request, followed by data-out */
  64 typedef struct {
  65     uint8_t lun[8];              /* Logical Unit Number */
  66     uint64_t tag;                /* Command identifier */
  67     uint8_t task_attr;           /* Task attribute */
  68     uint8_t prio;
  69     uint8_t crn;
  70     uint8_t cdb[];
  71 } QEMU_PACKED VirtIOSCSICmdReq;
  72
  73 /* Response, followed by sense data and data-in */
  74 typedef struct {
  75     uint32_t sense_len;          /* Sense data length */
  76     uint32_t resid;              /* Residual bytes in data buffer */
  77     uint16_t status_qualifier;   /* Status qualifier */
  78     uint8_t status;              /* Command completion status */
  79     uint8_t response;            /* Response values */
  80     uint8_t sense[];
  81 } QEMU_PACKED VirtIOSCSICmdResp;
  82
  83 /* Task Management Request */
  84 typedef struct {
  85     uint32_t type;
  86     uint32_t subtype;
  87     uint8_t lun[8];
  88     uint64_t tag;
  89 } QEMU_PACKED VirtIOSCSICtrlTMFReq;
  90
  91 typedef struct {
  92     uint8_t response;
  93 } QEMU_PACKED VirtIOSCSICtrlTMFResp;
  94
  95 /* Asynchronous notification query/subscription */
  96 typedef struct {
  97     uint32_t type;
  98     uint8_t lun[8];
  99     uint32_t event_requested;
 100 } QEMU_PACKED VirtIOSCSICtrlANReq;
 101
 102 typedef struct {
 103     uint32_t event_actual;
 104     uint8_t response;
 105 } QEMU_PACKED VirtIOSCSICtrlANResp;
 106
 107 typedef struct {
 108     uint32_t event;
 109     uint8_t lun[8];
 110     uint32_t reason;
 111 } QEMU_PACKED VirtIOSCSIEvent;
 112
 113 typedef struct {
 114     uint32_t num_queues;
 115     uint32_t seg_max;
 116     uint32_t max_sectors;
 117     uint32_t cmd_per_lun;
 118     uint32_t event_info_size;
 119     uint32_t sense_size;
 120     uint32_t cdb_size;
 121     uint16_t max_channel;
 122     uint16_t max_target;
 123     uint32_t max_lun;
 124 } QEMU_PACKED VirtIOSCSIConfig;
 125
 126 typedef struct {
 127     VirtIODevice vdev;
 128     DeviceState *qdev;
 129     VirtIOSCSIConf *conf;
 130
 131     SCSIBus bus;
 132     uint32_t sense_size;
 133     uint32_t cdb_size;
 134     int resetting;
 135     VirtQueue *ctrl_vq;
 136     VirtQueue *event_vq;
 137     VirtQueue *cmd_vqs[0];
 138 } VirtIOSCSI;
 139
 140 typedef struct VirtIOSCSIReq {
 141     VirtIOSCSI *dev;
 142     VirtQueue *vq;
 143     VirtQueueElement elem;
 144     QEMUSGList qsgl;
 145     SCSIRequest *sreq;
 146     union {
 147         char                  *buf;
 148         VirtIOSCSICmdReq      *cmd;
 149         VirtIOSCSICtrlTMFReq  *tmf;
 150         VirtIOSCSICtrlANReq   *an;
 151     } req;
 152     union {
 153         char                  *buf;
 154         VirtIOSCSICmdResp     *cmd;
 155         VirtIOSCSICtrlTMFResp *tmf;
 156         VirtIOSCSICtrlANResp  *an;
 157         VirtIOSCSIEvent       *event;
 158     } resp;
 159 } VirtIOSCSIReq;
 160
 161 static inline int virtio_scsi_get_lun(uint8_t *lun)
 162 {
 163     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
 164 }
 165
 166 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
 167 {
 168     if (lun[0] != 1) {
 169         return NULL;
 170     }
 171     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
 172         return NULL;
 173     }
 174     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
 175 }
 176
 177 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
 178 {
 179     VirtIOSCSI *s = req->dev;
 180     VirtQueue *vq = req->vq;
 181     virtqueue_push(vq, &req->elem, req->qsgl.size + req->elem.in_sg[0].iov_len);
 182     qemu_sglist_destroy(&req->qsgl);
 183     if (req->sreq) {
 184         req->sreq->hba_private = NULL;
 185         scsi_req_unref(req->sreq);
 186     }
 187     g_free(req);
 188     virtio_notify(&s->vdev, vq);
 189 }
 190
 191 static void virtio_scsi_bad_req(void)
 192 {
 193     error_report("wrong size for virtio-scsi headers");
 194     exit(1);
 195 }
 196
 197 static void qemu_sgl_init_external(QEMUSGList *qsgl, struct iovec *sg,
 198                                    target_phys_addr_t *addr, int num)
 199 {
 200     memset(qsgl, 0, sizeof(*qsgl));
 201     while (num--) {
 202         qemu_sglist_add(qsgl, *(addr++), (sg++)->iov_len);
 203     }
 204 }
 205
 206 static void virtio_scsi_parse_req(VirtIOSCSI *s, VirtQueue *vq,
 207                                   VirtIOSCSIReq *req)
 208 {
 209     assert(req->elem.out_num && req->elem.in_num);
 210     req->vq = vq;
 211     req->dev = s;
 212     req->sreq = NULL;
 213     req->req.buf = req->elem.out_sg[0].iov_base;
 214     req->resp.buf = req->elem.in_sg[0].iov_base;
 215
 216     if (req->elem.out_num > 1) {
 217         qemu_sgl_init_external(&req->qsgl, &req->elem.out_sg[1],
 218                                &req->elem.out_addr[1],
 219                                req->elem.out_num - 1);
 220     } else {
 221         qemu_sgl_init_external(&req->qsgl, &req->elem.in_sg[1],
 222                                &req->elem.in_addr[1],
 223                                req->elem.in_num - 1);
 224     }
 225 }
 226
 227 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 228 {
 229     VirtIOSCSIReq *req;
 230     req = g_malloc(sizeof(*req));
 231     if (!virtqueue_pop(vq, &req->elem)) {
 232         g_free(req);
 233         return NULL;
 234     }
 235
 236     virtio_scsi_parse_req(s, vq, req);
 237     return req;
 238 }
 239
 240 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 241 {
 242     VirtIOSCSIReq *req = sreq->hba_private;
 243     uint32_t n = virtio_queue_get_id(req->vq) - 2;
 244
 245     assert(n < req->dev->conf->num_queues);
 246     qemu_put_be32s(f, &n);
 247     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 248 }
 249
 250 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 251 {
 252     SCSIBus *bus = sreq->bus;
 253     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 254     VirtIOSCSIReq *req;
 255     uint32_t n;
 256
 257     req = g_malloc(sizeof(*req));
 258     qemu_get_be32s(f, &n);
 259     assert(n < s->conf->num_queues);
 260     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 261     virtio_scsi_parse_req(s, s->cmd_vqs[n], req);
 262
 263     scsi_req_ref(sreq);
 264     req->sreq = sreq;
 265     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 266         int req_mode =
 267             (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
 268
 269         assert(req->sreq->cmd.mode == req_mode);
 270     }
 271     return req;
 272 }
 273
 274 static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 275 {
 276     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf->lun);
 277     SCSIRequest *r, *next;
 278     BusChild *kid;
 279     int target;
 280
 281     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 282     req->resp.tmf->response = VIRTIO_SCSI_S_OK;
 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             if (r->tag == req->req.tmf->tag) {
 295                 break;
 296             }
 297         }
 298         if (r && r->hba_private) {
 299             if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 300                 /* "If the specified command is present in the task set, then
 301                  * return a service response set to FUNCTION SUCCEEDED".
 302                  */
 303                 req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 304             } else {
 305                 scsi_req_cancel(r);
 306             }
 307         }
 308         break;
 309
 310     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 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         s->resetting++;
 318         qdev_reset_all(&d->qdev);
 319         s->resetting--;
 320         break;
 321
 322     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 323     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 324     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 325         if (!d) {
 326             goto fail;
 327         }
 328         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 329             goto incorrect_lun;
 330         }
 331         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 332             if (r->hba_private) {
 333                 if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 334                     /* "If there is any command present in the task set, then
 335                      * return a service response set to FUNCTION SUCCEEDED".
 336                      */
 337                     req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 338                     break;
 339                 } else {
 340                     scsi_req_cancel(r);
 341                 }
 342             }
 343         }
 344         break;
 345
 346     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 347         target = req->req.tmf->lun[1];
 348         s->resetting++;
 349         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 350              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
 351              if (d->channel == 0 && d->id == target) {
 352                 qdev_reset_all(&d->qdev);
 353              }
 354         }
 355         s->resetting--;
 356         break;
 357
 358     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 359     default:
 360         req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 361         break;
 362     }
 363
 364     return;
 365
 366 incorrect_lun:
 367     req->resp.tmf->response = VIRTIO_SCSI_S_INCORRECT_LUN;
 368     return;
 369
 370 fail:
 371     req->resp.tmf->response = VIRTIO_SCSI_S_BAD_TARGET;
 372 }
 373
 374 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 375 {
 376     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 377     VirtIOSCSIReq *req;
 378
 379     while ((req = virtio_scsi_pop_req(s, vq))) {
 380         int out_size, in_size;
 381         if (req->elem.out_num < 1 || req->elem.in_num < 1) {
 382             virtio_scsi_bad_req();
 383             continue;
 384         }
 385
 386         out_size = req->elem.out_sg[0].iov_len;
 387         in_size = req->elem.in_sg[0].iov_len;
 388         if (req->req.tmf->type == VIRTIO_SCSI_T_TMF) {
 389             if (out_size < sizeof(VirtIOSCSICtrlTMFReq) ||
 390                 in_size < sizeof(VirtIOSCSICtrlTMFResp)) {
 391                 virtio_scsi_bad_req();
 392             }
 393             virtio_scsi_do_tmf(s, req);
 394
 395         } else if (req->req.tmf->type == VIRTIO_SCSI_T_AN_QUERY ||
 396                    req->req.tmf->type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 397             if (out_size < sizeof(VirtIOSCSICtrlANReq) ||
 398                 in_size < sizeof(VirtIOSCSICtrlANResp)) {
 399                 virtio_scsi_bad_req();
 400             }
 401             req->resp.an->event_actual = 0;
 402             req->resp.an->response = VIRTIO_SCSI_S_OK;
 403         }
 404         virtio_scsi_complete_req(req);
 405     }
 406 }
 407
 408 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 409 {
 410 }
 411
 412 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 413                                          size_t resid)
 414 {
 415     VirtIOSCSIReq *req = r->hba_private;
 416
 417     req->resp.cmd->response = VIRTIO_SCSI_S_OK;
 418     req->resp.cmd->status = status;
 419     if (req->resp.cmd->status == GOOD) {
 420         req->resp.cmd->resid = resid;
 421     } else {
 422         req->resp.cmd->resid = 0;
 423         req->resp.cmd->sense_len =
 424             scsi_req_get_sense(r, req->resp.cmd->sense, VIRTIO_SCSI_SENSE_SIZE);
 425     }
 426     virtio_scsi_complete_req(req);
 427 }
 428
 429 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 430 {
 431     VirtIOSCSIReq *req = r->hba_private;
 432
 433     return &req->qsgl;
 434 }
 435
 436 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 437 {
 438     VirtIOSCSIReq *req = r->hba_private;
 439
 440     if (!req) {
 441         return;
 442     }
 443     if (req->dev->resetting) {
 444         req->resp.cmd->response = VIRTIO_SCSI_S_RESET;
 445     } else {
 446         req->resp.cmd->response = VIRTIO_SCSI_S_ABORTED;
 447     }
 448     virtio_scsi_complete_req(req);
 449 }
 450
 451 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 452 {
 453     req->resp.cmd->response = VIRTIO_SCSI_S_FAILURE;
 454     virtio_scsi_complete_req(req);
 455 }
 456
 457 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 458 {
 459     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 460     VirtIOSCSIReq *req;
 461     int n;
 462
 463     while ((req = virtio_scsi_pop_req(s, vq))) {
 464         SCSIDevice *d;
 465         int out_size, in_size;
 466         if (req->elem.out_num < 1 || req->elem.in_num < 1) {
 467             virtio_scsi_bad_req();
 468         }
 469
 470         out_size = req->elem.out_sg[0].iov_len;
 471         in_size = req->elem.in_sg[0].iov_len;
 472         if (out_size < sizeof(VirtIOSCSICmdReq) + s->cdb_size ||
 473             in_size < sizeof(VirtIOSCSICmdResp) + s->sense_size) {
 474             virtio_scsi_bad_req();
 475         }
 476
 477         if (req->elem.out_num > 1 && req->elem.in_num > 1) {
 478             virtio_scsi_fail_cmd_req(req);
 479             continue;
 480         }
 481
 482         d = virtio_scsi_device_find(s, req->req.cmd->lun);
 483         if (!d) {
 484             req->resp.cmd->response = VIRTIO_SCSI_S_BAD_TARGET;
 485             virtio_scsi_complete_req(req);
 486             continue;
 487         }
 488         req->sreq = scsi_req_new(d, req->req.cmd->tag,
 489                                  virtio_scsi_get_lun(req->req.cmd->lun),
 490                                  req->req.cmd->cdb, req);
 491
 492         if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 493             int req_mode =
 494                 (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
 495
 496             if (req->sreq->cmd.mode != req_mode ||
 497                 req->sreq->cmd.xfer > req->qsgl.size) {
 498                 req->resp.cmd->response = VIRTIO_SCSI_S_OVERRUN;
 499                 virtio_scsi_complete_req(req);
 500                 continue;
 501             }
 502         }
 503
 504         n = scsi_req_enqueue(req->sreq);
 505         if (n) {
 506             scsi_req_continue(req->sreq);
 507         }
 508     }
 509 }
 510
 511 static void virtio_scsi_get_config(VirtIODevice *vdev,
 512                                    uint8_t *config)
 513 {
 514     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 515     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 516
 517     stl_raw(&scsiconf->num_queues, s->conf->num_queues);
 518     stl_raw(&scsiconf->seg_max, 128 - 2);
 519     stl_raw(&scsiconf->max_sectors, s->conf->max_sectors);
 520     stl_raw(&scsiconf->cmd_per_lun, s->conf->cmd_per_lun);
 521     stl_raw(&scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 522     stl_raw(&scsiconf->sense_size, s->sense_size);
 523     stl_raw(&scsiconf->cdb_size, s->cdb_size);
 524     stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 525     stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 526     stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 527 }
 528
 529 static void virtio_scsi_set_config(VirtIODevice *vdev,
 530                                    const uint8_t *config)
 531 {
 532     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 533     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 534
 535     if ((uint32_t) ldl_raw(&scsiconf->sense_size) >= 65536 ||
 536         (uint32_t) ldl_raw(&scsiconf->cdb_size) >= 256) {
 537         error_report("bad data written to virtio-scsi configuration space");
 538         exit(1);
 539     }
 540
 541     s->sense_size = ldl_raw(&scsiconf->sense_size);
 542     s->cdb_size = ldl_raw(&scsiconf->cdb_size);
 543 }
 544
 545 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
 546                                          uint32_t requested_features)
 547 {
 548     return requested_features;
 549 }
 550
 551 static void virtio_scsi_reset(VirtIODevice *vdev)
 552 {
 553     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 554
 555     s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
 556     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 557 }
 558
 559 /* The device does not have anything to save beyond the virtio data.
 560  * Request data is saved with callbacks from SCSI devices.
 561  */
 562 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 563 {
 564     VirtIOSCSI *s = opaque;
 565     virtio_save(&s->vdev, f);
 566 }
 567
 568 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 569 {
 570     VirtIOSCSI *s = opaque;
 571     int ret;
 572
 573     ret = virtio_load(&s->vdev, f);
 574     if (ret) {
 575         return ret;
 576     }
 577     return 0;
 578 }
 579
 580 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 581     .tcq = true,
 582     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 583     .max_target = VIRTIO_SCSI_MAX_TARGET,
 584     .max_lun = VIRTIO_SCSI_MAX_LUN,
 585
 586     .complete = virtio_scsi_command_complete,
 587     .cancel = virtio_scsi_request_cancelled,
 588     .get_sg_list = virtio_scsi_get_sg_list,
 589     .save_request = virtio_scsi_save_request,
 590     .load_request = virtio_scsi_load_request,
 591 };
 592
 593 VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf)
 594 {
 595     VirtIOSCSI *s;
 596     static int virtio_scsi_id;
 597     size_t sz;
 598     int i;
 599
 600     sz = sizeof(VirtIOSCSI) + proxyconf->num_queues * sizeof(VirtQueue *);
 601     s = (VirtIOSCSI *)virtio_common_init("virtio-scsi", VIRTIO_ID_SCSI,
 602                                          sizeof(VirtIOSCSIConfig), sz);
 603
 604     s->qdev = dev;
 605     s->conf = proxyconf;
 606
 607     /* TODO set up vdev function pointers */
 608     s->vdev.get_config = virtio_scsi_get_config;
 609     s->vdev.set_config = virtio_scsi_set_config;
 610     s->vdev.get_features = virtio_scsi_get_features;
 611     s->vdev.reset = virtio_scsi_reset;
 612
 613     s->ctrl_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 614                                    virtio_scsi_handle_ctrl);
 615     s->event_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 616                                    virtio_scsi_handle_event);
 617     for (i = 0; i < s->conf->num_queues; i++) {
 618         s->cmd_vqs[i] = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 619                                          virtio_scsi_handle_cmd);
 620     }
 621
 622     scsi_bus_new(&s->bus, dev, &virtio_scsi_scsi_info);
 623     if (!dev->hotplugged) {
 624         scsi_bus_legacy_handle_cmdline(&s->bus);
 625     }
 626
 627     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 628                     virtio_scsi_save, virtio_scsi_load, s);
 629
 630     return &s->vdev;
 631 }
 632
 633 void virtio_scsi_exit(VirtIODevice *vdev)
 634 {
 635     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 636     unregister_savevm(s->qdev, "virtio-scsi", s);
 637     virtio_cleanup(vdev);
 638 }