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 "hw/virtio-scsi.h"
  17 #include "qemu/error-report.h"
  18 #include <hw/scsi.h>
  19 #include <hw/scsi-defs.h>
  20
  21 #define VIRTIO_SCSI_VQ_SIZE     128
  22 #define VIRTIO_SCSI_CDB_SIZE    32
  23 #define VIRTIO_SCSI_SENSE_SIZE  96
  24 #define VIRTIO_SCSI_MAX_CHANNEL 0
  25 #define VIRTIO_SCSI_MAX_TARGET  255
  26 #define VIRTIO_SCSI_MAX_LUN     16383
  27
  28 /* Response codes */
  29 #define VIRTIO_SCSI_S_OK                       0
  30 #define VIRTIO_SCSI_S_OVERRUN                  1
  31 #define VIRTIO_SCSI_S_ABORTED                  2
  32 #define VIRTIO_SCSI_S_BAD_TARGET               3
  33 #define VIRTIO_SCSI_S_RESET                    4
  34 #define VIRTIO_SCSI_S_BUSY                     5
  35 #define VIRTIO_SCSI_S_TRANSPORT_FAILURE        6
  36 #define VIRTIO_SCSI_S_TARGET_FAILURE           7
  37 #define VIRTIO_SCSI_S_NEXUS_FAILURE            8
  38 #define VIRTIO_SCSI_S_FAILURE                  9
  39 #define VIRTIO_SCSI_S_FUNCTION_SUCCEEDED       10
  40 #define VIRTIO_SCSI_S_FUNCTION_REJECTED        11
  41 #define VIRTIO_SCSI_S_INCORRECT_LUN            12
  42
  43 /* Controlq type codes.  */
  44 #define VIRTIO_SCSI_T_TMF                      0
  45 #define VIRTIO_SCSI_T_AN_QUERY                 1
  46 #define VIRTIO_SCSI_T_AN_SUBSCRIBE             2
  47
  48 /* Valid TMF subtypes.  */
  49 #define VIRTIO_SCSI_T_TMF_ABORT_TASK           0
  50 #define VIRTIO_SCSI_T_TMF_ABORT_TASK_SET       1
  51 #define VIRTIO_SCSI_T_TMF_CLEAR_ACA            2
  52 #define VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET       3
  53 #define VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET      4
  54 #define VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET   5
  55 #define VIRTIO_SCSI_T_TMF_QUERY_TASK           6
  56 #define VIRTIO_SCSI_T_TMF_QUERY_TASK_SET       7
  57
  58 /* Events.  */
  59 #define VIRTIO_SCSI_T_EVENTS_MISSED            0x80000000
  60 #define VIRTIO_SCSI_T_NO_EVENT                 0
  61 #define VIRTIO_SCSI_T_TRANSPORT_RESET          1
  62 #define VIRTIO_SCSI_T_ASYNC_NOTIFY             2
  63 #define VIRTIO_SCSI_T_PARAM_CHANGE             3
  64
  65 /* Reasons for transport reset event */
  66 #define VIRTIO_SCSI_EVT_RESET_HARD             0
  67 #define VIRTIO_SCSI_EVT_RESET_RESCAN           1
  68 #define VIRTIO_SCSI_EVT_RESET_REMOVED          2
  69
  70 /* SCSI command request, followed by data-out */
  71 typedef struct {
  72     uint8_t lun[8];              /* Logical Unit Number */
  73     uint64_t tag;                /* Command identifier */
  74     uint8_t task_attr;           /* Task attribute */
  75     uint8_t prio;
  76     uint8_t crn;
  77     uint8_t cdb[];
  78 } QEMU_PACKED VirtIOSCSICmdReq;
  79
  80 /* Response, followed by sense data and data-in */
  81 typedef struct {
  82     uint32_t sense_len;          /* Sense data length */
  83     uint32_t resid;              /* Residual bytes in data buffer */
  84     uint16_t status_qualifier;   /* Status qualifier */
  85     uint8_t status;              /* Command completion status */
  86     uint8_t response;            /* Response values */
  87     uint8_t sense[];
  88 } QEMU_PACKED VirtIOSCSICmdResp;
  89
  90 /* Task Management Request */
  91 typedef struct {
  92     uint32_t type;
  93     uint32_t subtype;
  94     uint8_t lun[8];
  95     uint64_t tag;
  96 } QEMU_PACKED VirtIOSCSICtrlTMFReq;
  97
  98 typedef struct {
  99     uint8_t response;
 100 } QEMU_PACKED VirtIOSCSICtrlTMFResp;
 101
 102 /* Asynchronous notification query/subscription */
 103 typedef struct {
 104     uint32_t type;
 105     uint8_t lun[8];
 106     uint32_t event_requested;
 107 } QEMU_PACKED VirtIOSCSICtrlANReq;
 108
 109 typedef struct {
 110     uint32_t event_actual;
 111     uint8_t response;
 112 } QEMU_PACKED VirtIOSCSICtrlANResp;
 113
 114 typedef struct {
 115     uint32_t event;
 116     uint8_t lun[8];
 117     uint32_t reason;
 118 } QEMU_PACKED VirtIOSCSIEvent;
 119
 120 typedef struct {
 121     uint32_t num_queues;
 122     uint32_t seg_max;
 123     uint32_t max_sectors;
 124     uint32_t cmd_per_lun;
 125     uint32_t event_info_size;
 126     uint32_t sense_size;
 127     uint32_t cdb_size;
 128     uint16_t max_channel;
 129     uint16_t max_target;
 130     uint32_t max_lun;
 131 } QEMU_PACKED VirtIOSCSIConfig;
 132
 133 typedef struct VirtIOSCSIReq {
 134     VirtIOSCSI *dev;
 135     VirtQueue *vq;
 136     VirtQueueElement elem;
 137     QEMUSGList qsgl;
 138     SCSIRequest *sreq;
 139     union {
 140         char                  *buf;
 141         VirtIOSCSICmdReq      *cmd;
 142         VirtIOSCSICtrlTMFReq  *tmf;
 143         VirtIOSCSICtrlANReq   *an;
 144     } req;
 145     union {
 146         char                  *buf;
 147         VirtIOSCSICmdResp     *cmd;
 148         VirtIOSCSICtrlTMFResp *tmf;
 149         VirtIOSCSICtrlANResp  *an;
 150         VirtIOSCSIEvent       *event;
 151     } resp;
 152 } VirtIOSCSIReq;
 153
 154 static inline int virtio_scsi_get_lun(uint8_t *lun)
 155 {
 156     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
 157 }
 158
 159 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
 160 {
 161     if (lun[0] != 1) {
 162         return NULL;
 163     }
 164     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
 165         return NULL;
 166     }
 167     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
 168 }
 169
 170 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
 171 {
 172     VirtIOSCSI *s = req->dev;
 173     VirtQueue *vq = req->vq;
 174     virtqueue_push(vq, &req->elem, req->qsgl.size + req->elem.in_sg[0].iov_len);
 175     qemu_sglist_destroy(&req->qsgl);
 176     if (req->sreq) {
 177         req->sreq->hba_private = NULL;
 178         scsi_req_unref(req->sreq);
 179     }
 180     g_free(req);
 181     virtio_notify(&s->vdev, vq);
 182 }
 183
 184 static void virtio_scsi_bad_req(void)
 185 {
 186     error_report("wrong size for virtio-scsi headers");
 187     exit(1);
 188 }
 189
 190 static void qemu_sgl_init_external(QEMUSGList *qsgl, struct iovec *sg,
 191                                    hwaddr *addr, int num)
 192 {
 193     qemu_sglist_init(qsgl, num, &dma_context_memory);
 194     while (num--) {
 195         qemu_sglist_add(qsgl, *(addr++), (sg++)->iov_len);
 196     }
 197 }
 198
 199 static void virtio_scsi_parse_req(VirtIOSCSI *s, VirtQueue *vq,
 200                                   VirtIOSCSIReq *req)
 201 {
 202     assert(req->elem.in_num);
 203     req->vq = vq;
 204     req->dev = s;
 205     req->sreq = NULL;
 206     if (req->elem.out_num) {
 207         req->req.buf = req->elem.out_sg[0].iov_base;
 208     }
 209     req->resp.buf = req->elem.in_sg[0].iov_base;
 210
 211     if (req->elem.out_num > 1) {
 212         qemu_sgl_init_external(&req->qsgl, &req->elem.out_sg[1],
 213                                &req->elem.out_addr[1],
 214                                req->elem.out_num - 1);
 215     } else {
 216         qemu_sgl_init_external(&req->qsgl, &req->elem.in_sg[1],
 217                                &req->elem.in_addr[1],
 218                                req->elem.in_num - 1);
 219     }
 220 }
 221
 222 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 223 {
 224     VirtIOSCSIReq *req;
 225     req = g_malloc(sizeof(*req));
 226     if (!virtqueue_pop(vq, &req->elem)) {
 227         g_free(req);
 228         return NULL;
 229     }
 230
 231     virtio_scsi_parse_req(s, vq, req);
 232     return req;
 233 }
 234
 235 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 236 {
 237     VirtIOSCSIReq *req = sreq->hba_private;
 238     uint32_t n = virtio_queue_get_id(req->vq) - 2;
 239
 240     assert(n < req->dev->conf->num_queues);
 241     qemu_put_be32s(f, &n);
 242     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 243 }
 244
 245 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 246 {
 247     SCSIBus *bus = sreq->bus;
 248     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 249     VirtIOSCSIReq *req;
 250     uint32_t n;
 251
 252     req = g_malloc(sizeof(*req));
 253     qemu_get_be32s(f, &n);
 254     assert(n < s->conf->num_queues);
 255     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 256     virtio_scsi_parse_req(s, s->cmd_vqs[n], req);
 257
 258     scsi_req_ref(sreq);
 259     req->sreq = sreq;
 260     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 261         int req_mode =
 262             (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
 263
 264         assert(req->sreq->cmd.mode == req_mode);
 265     }
 266     return req;
 267 }
 268
 269 static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 270 {
 271     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf->lun);
 272     SCSIRequest *r, *next;
 273     BusChild *kid;
 274     int target;
 275
 276     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 277     req->resp.tmf->response = VIRTIO_SCSI_S_OK;
 278
 279     switch (req->req.tmf->subtype) {
 280     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 281     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 282         if (!d) {
 283             goto fail;
 284         }
 285         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 286             goto incorrect_lun;
 287         }
 288         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 289             VirtIOSCSIReq *cmd_req = r->hba_private;
 290             if (cmd_req && cmd_req->req.cmd->tag == req->req.tmf->tag) {
 291                 break;
 292             }
 293         }
 294         if (r) {
 295             /*
 296              * Assert that the request has not been completed yet, we
 297              * check for it in the loop above.
 298              */
 299             assert(r->hba_private);
 300             if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 301                 /* "If the specified command is present in the task set, then
 302                  * return a service response set to FUNCTION SUCCEEDED".
 303                  */
 304                 req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 305             } else {
 306                 scsi_req_cancel(r);
 307             }
 308         }
 309         break;
 310
 311     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 312         if (!d) {
 313             goto fail;
 314         }
 315         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 316             goto incorrect_lun;
 317         }
 318         s->resetting++;
 319         qdev_reset_all(&d->qdev);
 320         s->resetting--;
 321         break;
 322
 323     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 324     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 325     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 326         if (!d) {
 327             goto fail;
 328         }
 329         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 330             goto incorrect_lun;
 331         }
 332         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 333             if (r->hba_private) {
 334                 if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 335                     /* "If there is any command present in the task set, then
 336                      * return a service response set to FUNCTION SUCCEEDED".
 337                      */
 338                     req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 339                     break;
 340                 } else {
 341                     scsi_req_cancel(r);
 342                 }
 343             }
 344         }
 345         break;
 346
 347     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 348         target = req->req.tmf->lun[1];
 349         s->resetting++;
 350         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 351              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
 352              if (d->channel == 0 && d->id == target) {
 353                 qdev_reset_all(&d->qdev);
 354              }
 355         }
 356         s->resetting--;
 357         break;
 358
 359     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 360     default:
 361         req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 362         break;
 363     }
 364
 365     return;
 366
 367 incorrect_lun:
 368     req->resp.tmf->response = VIRTIO_SCSI_S_INCORRECT_LUN;
 369     return;
 370
 371 fail:
 372     req->resp.tmf->response = VIRTIO_SCSI_S_BAD_TARGET;
 373 }
 374
 375 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 376 {
 377     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 378     VirtIOSCSIReq *req;
 379
 380     while ((req = virtio_scsi_pop_req(s, vq))) {
 381         int out_size, in_size;
 382         if (req->elem.out_num < 1 || req->elem.in_num < 1) {
 383             virtio_scsi_bad_req();
 384             continue;
 385         }
 386
 387         out_size = req->elem.out_sg[0].iov_len;
 388         in_size = req->elem.in_sg[0].iov_len;
 389         if (req->req.tmf->type == VIRTIO_SCSI_T_TMF) {
 390             if (out_size < sizeof(VirtIOSCSICtrlTMFReq) ||
 391                 in_size < sizeof(VirtIOSCSICtrlTMFResp)) {
 392                 virtio_scsi_bad_req();
 393             }
 394             virtio_scsi_do_tmf(s, req);
 395
 396         } else if (req->req.tmf->type == VIRTIO_SCSI_T_AN_QUERY ||
 397                    req->req.tmf->type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 398             if (out_size < sizeof(VirtIOSCSICtrlANReq) ||
 399                 in_size < sizeof(VirtIOSCSICtrlANResp)) {
 400                 virtio_scsi_bad_req();
 401             }
 402             req->resp.an->event_actual = 0;
 403             req->resp.an->response = VIRTIO_SCSI_S_OK;
 404         }
 405         virtio_scsi_complete_req(req);
 406     }
 407 }
 408
 409 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 410                                          size_t resid)
 411 {
 412     VirtIOSCSIReq *req = r->hba_private;
 413     uint32_t sense_len;
 414
 415     req->resp.cmd->response = VIRTIO_SCSI_S_OK;
 416     req->resp.cmd->status = status;
 417     if (req->resp.cmd->status == GOOD) {
 418         req->resp.cmd->resid = tswap32(resid);
 419     } else {
 420         req->resp.cmd->resid = 0;
 421         sense_len = scsi_req_get_sense(r, req->resp.cmd->sense,
 422                                        VIRTIO_SCSI_SENSE_SIZE);
 423         req->resp.cmd->sense_len = tswap32(sense_len);
 424     }
 425     virtio_scsi_complete_req(req);
 426 }
 427
 428 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 429 {
 430     VirtIOSCSIReq *req = r->hba_private;
 431
 432     return &req->qsgl;
 433 }
 434
 435 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 436 {
 437     VirtIOSCSIReq *req = r->hba_private;
 438
 439     if (!req) {
 440         return;
 441     }
 442     if (req->dev->resetting) {
 443         req->resp.cmd->response = VIRTIO_SCSI_S_RESET;
 444     } else {
 445         req->resp.cmd->response = VIRTIO_SCSI_S_ABORTED;
 446     }
 447     virtio_scsi_complete_req(req);
 448 }
 449
 450 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 451 {
 452     req->resp.cmd->response = VIRTIO_SCSI_S_FAILURE;
 453     virtio_scsi_complete_req(req);
 454 }
 455
 456 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 457 {
 458     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 459     VirtIOSCSIReq *req;
 460     int n;
 461
 462     while ((req = virtio_scsi_pop_req(s, vq))) {
 463         SCSIDevice *d;
 464         int out_size, in_size;
 465         if (req->elem.out_num < 1 || req->elem.in_num < 1) {
 466             virtio_scsi_bad_req();
 467         }
 468
 469         out_size = req->elem.out_sg[0].iov_len;
 470         in_size = req->elem.in_sg[0].iov_len;
 471         if (out_size < sizeof(VirtIOSCSICmdReq) + s->cdb_size ||
 472             in_size < sizeof(VirtIOSCSICmdResp) + s->sense_size) {
 473             virtio_scsi_bad_req();
 474         }
 475
 476         if (req->elem.out_num > 1 && req->elem.in_num > 1) {
 477             virtio_scsi_fail_cmd_req(req);
 478             continue;
 479         }
 480
 481         d = virtio_scsi_device_find(s, req->req.cmd->lun);
 482         if (!d) {
 483             req->resp.cmd->response = VIRTIO_SCSI_S_BAD_TARGET;
 484             virtio_scsi_complete_req(req);
 485             continue;
 486         }
 487         req->sreq = scsi_req_new(d, req->req.cmd->tag,
 488                                  virtio_scsi_get_lun(req->req.cmd->lun),
 489                                  req->req.cmd->cdb, req);
 490
 491         if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 492             int req_mode =
 493                 (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
 494
 495             if (req->sreq->cmd.mode != req_mode ||
 496                 req->sreq->cmd.xfer > req->qsgl.size) {
 497                 req->resp.cmd->response = VIRTIO_SCSI_S_OVERRUN;
 498                 virtio_scsi_complete_req(req);
 499                 continue;
 500             }
 501         }
 502
 503         n = scsi_req_enqueue(req->sreq);
 504         if (n) {
 505             scsi_req_continue(req->sreq);
 506         }
 507     }
 508 }
 509
 510 static void virtio_scsi_get_config(VirtIODevice *vdev,
 511                                    uint8_t *config)
 512 {
 513     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 514     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 515
 516     stl_raw(&scsiconf->num_queues, s->conf->num_queues);
 517     stl_raw(&scsiconf->seg_max, 128 - 2);
 518     stl_raw(&scsiconf->max_sectors, s->conf->max_sectors);
 519     stl_raw(&scsiconf->cmd_per_lun, s->conf->cmd_per_lun);
 520     stl_raw(&scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 521     stl_raw(&scsiconf->sense_size, s->sense_size);
 522     stl_raw(&scsiconf->cdb_size, s->cdb_size);
 523     stw_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 524     stw_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 525     stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 526 }
 527
 528 static void virtio_scsi_set_config(VirtIODevice *vdev,
 529                                    const uint8_t *config)
 530 {
 531     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 532     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 533
 534     if ((uint32_t) ldl_raw(&scsiconf->sense_size) >= 65536 ||
 535         (uint32_t) ldl_raw(&scsiconf->cdb_size) >= 256) {
 536         error_report("bad data written to virtio-scsi configuration space");
 537         exit(1);
 538     }
 539
 540     s->sense_size = ldl_raw(&scsiconf->sense_size);
 541     s->cdb_size = ldl_raw(&scsiconf->cdb_size);
 542 }
 543
 544 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
 545                                          uint32_t requested_features)
 546 {
 547     return requested_features;
 548 }
 549
 550 static void virtio_scsi_reset(VirtIODevice *vdev)
 551 {
 552     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 553
 554     s->resetting++;
 555     qbus_reset_all(&s->bus.qbus);
 556     s->resetting--;
 557
 558     s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
 559     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 560     s->events_dropped = false;
 561 }
 562
 563 /* The device does not have anything to save beyond the virtio data.
 564  * Request data is saved with callbacks from SCSI devices.
 565  */
 566 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 567 {
 568     VirtIOSCSI *s = opaque;
 569     virtio_save(&s->vdev, f);
 570 }
 571
 572 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 573 {
 574     VirtIOSCSI *s = opaque;
 575     int ret;
 576
 577     ret = virtio_load(&s->vdev, f);
 578     if (ret) {
 579         return ret;
 580     }
 581     return 0;
 582 }
 583
 584 static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 585                                    uint32_t event, uint32_t reason)
 586 {
 587     VirtIOSCSIReq *req = virtio_scsi_pop_req(s, s->event_vq);
 588     VirtIOSCSIEvent *evt;
 589     int in_size;
 590
 591     if (!(s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 592         return;
 593     }
 594
 595     if (!req) {
 596         s->events_dropped = true;
 597         return;
 598     }
 599
 600     if (req->elem.out_num || req->elem.in_num != 1) {
 601         virtio_scsi_bad_req();
 602     }
 603
 604     if (s->events_dropped) {
 605         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 606         s->events_dropped = false;
 607     }
 608
 609     in_size = req->elem.in_sg[0].iov_len;
 610     if (in_size < sizeof(VirtIOSCSIEvent)) {
 611         virtio_scsi_bad_req();
 612     }
 613
 614     evt = req->resp.event;
 615     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 616     evt->event = event;
 617     evt->reason = reason;
 618     if (!dev) {
 619         assert(event == VIRTIO_SCSI_T_NO_EVENT);
 620     } else {
 621         evt->lun[0] = 1;
 622         evt->lun[1] = dev->id;
 623
 624         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 625         if (dev->lun >= 256) {
 626             evt->lun[2] = (dev->lun >> 8) | 0x40;
 627         }
 628         evt->lun[3] = dev->lun & 0xFF;
 629     }
 630     virtio_scsi_complete_req(req);
 631 }
 632
 633 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 634 {
 635     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 636
 637     if (s->events_dropped) {
 638         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 639     }
 640 }
 641
 642 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 643 {
 644     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 645
 646     if (((s->vdev.guest_features >> VIRTIO_SCSI_F_CHANGE) & 1) &&
 647         dev->type != TYPE_ROM) {
 648         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 649                                sense.asc | (sense.ascq << 8));
 650     }
 651 }
 652
 653 static void virtio_scsi_hotplug(SCSIBus *bus, SCSIDevice *dev)
 654 {
 655     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 656
 657     if ((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
 658         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
 659                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 660     }
 661 }
 662
 663 static void virtio_scsi_hot_unplug(SCSIBus *bus, SCSIDevice *dev)
 664 {
 665     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 666
 667     if ((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
 668         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
 669                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 670     }
 671 }
 672
 673 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 674     .tcq = true,
 675     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 676     .max_target = VIRTIO_SCSI_MAX_TARGET,
 677     .max_lun = VIRTIO_SCSI_MAX_LUN,
 678
 679     .complete = virtio_scsi_command_complete,
 680     .cancel = virtio_scsi_request_cancelled,
 681     .change = virtio_scsi_change,
 682     .hotplug = virtio_scsi_hotplug,
 683     .hot_unplug = virtio_scsi_hot_unplug,
 684     .get_sg_list = virtio_scsi_get_sg_list,
 685     .save_request = virtio_scsi_save_request,
 686     .load_request = virtio_scsi_load_request,
 687 };
 688
 689 VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf)
 690 {
 691     VirtIOSCSI *s;
 692     static int virtio_scsi_id;
 693     size_t sz;
 694     int i;
 695
 696     sz = sizeof(VirtIOSCSI) + proxyconf->num_queues * sizeof(VirtQueue *);
 697     s = (VirtIOSCSI *)virtio_common_init("virtio-scsi", VIRTIO_ID_SCSI,
 698                                          sizeof(VirtIOSCSIConfig), sz);
 699
 700     s->qdev = dev;
 701     s->conf = proxyconf;
 702
 703     /* TODO set up vdev function pointers */
 704     s->vdev.get_config = virtio_scsi_get_config;
 705     s->vdev.set_config = virtio_scsi_set_config;
 706     s->vdev.get_features = virtio_scsi_get_features;
 707     s->vdev.reset = virtio_scsi_reset;
 708
 709     s->ctrl_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 710                                    virtio_scsi_handle_ctrl);
 711     s->event_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 712                                    virtio_scsi_handle_event);
 713     for (i = 0; i < s->conf->num_queues; i++) {
 714         s->cmd_vqs[i] = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 715                                          virtio_scsi_handle_cmd);
 716     }
 717
 718     scsi_bus_new(&s->bus, dev, &virtio_scsi_scsi_info);
 719     if (!dev->hotplugged) {
 720         scsi_bus_legacy_handle_cmdline(&s->bus);
 721     }
 722
 723     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 724                     virtio_scsi_save, virtio_scsi_load, s);
 725
 726     return &s->vdev;
 727 }
 728
 729 void virtio_scsi_exit(VirtIODevice *vdev)
 730 {
 731     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 732     unregister_savevm(s->qdev, "virtio-scsi", s);
 733     virtio_cleanup(vdev);
 734 }