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 /* Feature Bits */
  28 #define VIRTIO_SCSI_F_INOUT                    0
  29 #define VIRTIO_SCSI_F_HOTPLUG                  1
  30 #define VIRTIO_SCSI_F_CHANGE                   2
  31
  32 /* Response codes */
  33 #define VIRTIO_SCSI_S_OK                       0
  34 #define VIRTIO_SCSI_S_OVERRUN                  1
  35 #define VIRTIO_SCSI_S_ABORTED                  2
  36 #define VIRTIO_SCSI_S_BAD_TARGET               3
  37 #define VIRTIO_SCSI_S_RESET                    4
  38 #define VIRTIO_SCSI_S_BUSY                     5
  39 #define VIRTIO_SCSI_S_TRANSPORT_FAILURE        6
  40 #define VIRTIO_SCSI_S_TARGET_FAILURE           7
  41 #define VIRTIO_SCSI_S_NEXUS_FAILURE            8
  42 #define VIRTIO_SCSI_S_FAILURE                  9
  43 #define VIRTIO_SCSI_S_FUNCTION_SUCCEEDED       10
  44 #define VIRTIO_SCSI_S_FUNCTION_REJECTED        11
  45 #define VIRTIO_SCSI_S_INCORRECT_LUN            12
  46
  47 /* Controlq type codes.  */
  48 #define VIRTIO_SCSI_T_TMF                      0
  49 #define VIRTIO_SCSI_T_AN_QUERY                 1
  50 #define VIRTIO_SCSI_T_AN_SUBSCRIBE             2
  51
  52 /* Valid TMF subtypes.  */
  53 #define VIRTIO_SCSI_T_TMF_ABORT_TASK           0
  54 #define VIRTIO_SCSI_T_TMF_ABORT_TASK_SET       1
  55 #define VIRTIO_SCSI_T_TMF_CLEAR_ACA            2
  56 #define VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET       3
  57 #define VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET      4
  58 #define VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET   5
  59 #define VIRTIO_SCSI_T_TMF_QUERY_TASK           6
  60 #define VIRTIO_SCSI_T_TMF_QUERY_TASK_SET       7
  61
  62 /* Events.  */
  63 #define VIRTIO_SCSI_T_EVENTS_MISSED            0x80000000
  64 #define VIRTIO_SCSI_T_NO_EVENT                 0
  65 #define VIRTIO_SCSI_T_TRANSPORT_RESET          1
  66 #define VIRTIO_SCSI_T_ASYNC_NOTIFY             2
  67 #define VIRTIO_SCSI_T_PARAM_CHANGE             3
  68
  69 /* Reasons for transport reset event */
  70 #define VIRTIO_SCSI_EVT_RESET_HARD             0
  71 #define VIRTIO_SCSI_EVT_RESET_RESCAN           1
  72 #define VIRTIO_SCSI_EVT_RESET_REMOVED          2
  73
  74 /* SCSI command request, followed by data-out */
  75 typedef struct {
  76     uint8_t lun[8];              /* Logical Unit Number */
  77     uint64_t tag;                /* Command identifier */
  78     uint8_t task_attr;           /* Task attribute */
  79     uint8_t prio;
  80     uint8_t crn;
  81     uint8_t cdb[];
  82 } QEMU_PACKED VirtIOSCSICmdReq;
  83
  84 /* Response, followed by sense data and data-in */
  85 typedef struct {
  86     uint32_t sense_len;          /* Sense data length */
  87     uint32_t resid;              /* Residual bytes in data buffer */
  88     uint16_t status_qualifier;   /* Status qualifier */
  89     uint8_t status;              /* Command completion status */
  90     uint8_t response;            /* Response values */
  91     uint8_t sense[];
  92 } QEMU_PACKED VirtIOSCSICmdResp;
  93
  94 /* Task Management Request */
  95 typedef struct {
  96     uint32_t type;
  97     uint32_t subtype;
  98     uint8_t lun[8];
  99     uint64_t tag;
 100 } QEMU_PACKED VirtIOSCSICtrlTMFReq;
 101
 102 typedef struct {
 103     uint8_t response;
 104 } QEMU_PACKED VirtIOSCSICtrlTMFResp;
 105
 106 /* Asynchronous notification query/subscription */
 107 typedef struct {
 108     uint32_t type;
 109     uint8_t lun[8];
 110     uint32_t event_requested;
 111 } QEMU_PACKED VirtIOSCSICtrlANReq;
 112
 113 typedef struct {
 114     uint32_t event_actual;
 115     uint8_t response;
 116 } QEMU_PACKED VirtIOSCSICtrlANResp;
 117
 118 typedef struct {
 119     uint32_t event;
 120     uint8_t lun[8];
 121     uint32_t reason;
 122 } QEMU_PACKED VirtIOSCSIEvent;
 123
 124 typedef struct {
 125     uint32_t num_queues;
 126     uint32_t seg_max;
 127     uint32_t max_sectors;
 128     uint32_t cmd_per_lun;
 129     uint32_t event_info_size;
 130     uint32_t sense_size;
 131     uint32_t cdb_size;
 132     uint16_t max_channel;
 133     uint16_t max_target;
 134     uint32_t max_lun;
 135 } QEMU_PACKED VirtIOSCSIConfig;
 136
 137 typedef struct {
 138     VirtIODevice vdev;
 139     DeviceState *qdev;
 140     VirtIOSCSIConf *conf;
 141
 142     SCSIBus bus;
 143     uint32_t sense_size;
 144     uint32_t cdb_size;
 145     int resetting;
 146     bool events_dropped;
 147     VirtQueue *ctrl_vq;
 148     VirtQueue *event_vq;
 149     VirtQueue *cmd_vqs[0];
 150 } VirtIOSCSI;
 151
 152 typedef struct VirtIOSCSIReq {
 153     VirtIOSCSI *dev;
 154     VirtQueue *vq;
 155     VirtQueueElement elem;
 156     QEMUSGList qsgl;
 157     SCSIRequest *sreq;
 158     union {
 159         char                  *buf;
 160         VirtIOSCSICmdReq      *cmd;
 161         VirtIOSCSICtrlTMFReq  *tmf;
 162         VirtIOSCSICtrlANReq   *an;
 163     } req;
 164     union {
 165         char                  *buf;
 166         VirtIOSCSICmdResp     *cmd;
 167         VirtIOSCSICtrlTMFResp *tmf;
 168         VirtIOSCSICtrlANResp  *an;
 169         VirtIOSCSIEvent       *event;
 170     } resp;
 171 } VirtIOSCSIReq;
 172
 173 static inline int virtio_scsi_get_lun(uint8_t *lun)
 174 {
 175     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
 176 }
 177
 178 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
 179 {
 180     if (lun[0] != 1) {
 181         return NULL;
 182     }
 183     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
 184         return NULL;
 185     }
 186     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
 187 }
 188
 189 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
 190 {
 191     VirtIOSCSI *s = req->dev;
 192     VirtQueue *vq = req->vq;
 193     virtqueue_push(vq, &req->elem, req->qsgl.size + req->elem.in_sg[0].iov_len);
 194     qemu_sglist_destroy(&req->qsgl);
 195     if (req->sreq) {
 196         req->sreq->hba_private = NULL;
 197         scsi_req_unref(req->sreq);
 198     }
 199     g_free(req);
 200     virtio_notify(&s->vdev, vq);
 201 }
 202
 203 static void virtio_scsi_bad_req(void)
 204 {
 205     error_report("wrong size for virtio-scsi headers");
 206     exit(1);
 207 }
 208
 209 static void qemu_sgl_init_external(QEMUSGList *qsgl, struct iovec *sg,
 210                                    target_phys_addr_t *addr, int num)
 211 {
 212     memset(qsgl, 0, sizeof(*qsgl));
 213     while (num--) {
 214         qemu_sglist_add(qsgl, *(addr++), (sg++)->iov_len);
 215     }
 216 }
 217
 218 static void virtio_scsi_parse_req(VirtIOSCSI *s, VirtQueue *vq,
 219                                   VirtIOSCSIReq *req)
 220 {
 221     assert(req->elem.in_num);
 222     req->vq = vq;
 223     req->dev = s;
 224     req->sreq = NULL;
 225     if (req->elem.out_num) {
 226         req->req.buf = req->elem.out_sg[0].iov_base;
 227     }
 228     req->resp.buf = req->elem.in_sg[0].iov_base;
 229
 230     if (req->elem.out_num > 1) {
 231         qemu_sgl_init_external(&req->qsgl, &req->elem.out_sg[1],
 232                                &req->elem.out_addr[1],
 233                                req->elem.out_num - 1);
 234     } else {
 235         qemu_sgl_init_external(&req->qsgl, &req->elem.in_sg[1],
 236                                &req->elem.in_addr[1],
 237                                req->elem.in_num - 1);
 238     }
 239 }
 240
 241 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 242 {
 243     VirtIOSCSIReq *req;
 244     req = g_malloc(sizeof(*req));
 245     if (!virtqueue_pop(vq, &req->elem)) {
 246         g_free(req);
 247         return NULL;
 248     }
 249
 250     virtio_scsi_parse_req(s, vq, req);
 251     return req;
 252 }
 253
 254 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 255 {
 256     VirtIOSCSIReq *req = sreq->hba_private;
 257     uint32_t n = virtio_queue_get_id(req->vq) - 2;
 258
 259     assert(n < req->dev->conf->num_queues);
 260     qemu_put_be32s(f, &n);
 261     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 262 }
 263
 264 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 265 {
 266     SCSIBus *bus = sreq->bus;
 267     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 268     VirtIOSCSIReq *req;
 269     uint32_t n;
 270
 271     req = g_malloc(sizeof(*req));
 272     qemu_get_be32s(f, &n);
 273     assert(n < s->conf->num_queues);
 274     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 275     virtio_scsi_parse_req(s, s->cmd_vqs[n], req);
 276
 277     scsi_req_ref(sreq);
 278     req->sreq = sreq;
 279     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 280         int req_mode =
 281             (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
 282
 283         assert(req->sreq->cmd.mode == req_mode);
 284     }
 285     return req;
 286 }
 287
 288 static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 289 {
 290     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf->lun);
 291     SCSIRequest *r, *next;
 292     BusChild *kid;
 293     int target;
 294
 295     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 296     req->resp.tmf->response = VIRTIO_SCSI_S_OK;
 297
 298     switch (req->req.tmf->subtype) {
 299     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 300     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 301         if (!d) {
 302             goto fail;
 303         }
 304         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 305             goto incorrect_lun;
 306         }
 307         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 308             if (r->tag == req->req.tmf->tag) {
 309                 break;
 310             }
 311         }
 312         if (r && r->hba_private) {
 313             if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 314                 /* "If the specified command is present in the task set, then
 315                  * return a service response set to FUNCTION SUCCEEDED".
 316                  */
 317                 req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 318             } else {
 319                 scsi_req_cancel(r);
 320             }
 321         }
 322         break;
 323
 324     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 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         s->resetting++;
 332         qdev_reset_all(&d->qdev);
 333         s->resetting--;
 334         break;
 335
 336     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 337     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 338     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 339         if (!d) {
 340             goto fail;
 341         }
 342         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 343             goto incorrect_lun;
 344         }
 345         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 346             if (r->hba_private) {
 347                 if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 348                     /* "If there is any command present in the task set, then
 349                      * return a service response set to FUNCTION SUCCEEDED".
 350                      */
 351                     req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 352                     break;
 353                 } else {
 354                     scsi_req_cancel(r);
 355                 }
 356             }
 357         }
 358         break;
 359
 360     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 361         target = req->req.tmf->lun[1];
 362         s->resetting++;
 363         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 364              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
 365              if (d->channel == 0 && d->id == target) {
 366                 qdev_reset_all(&d->qdev);
 367              }
 368         }
 369         s->resetting--;
 370         break;
 371
 372     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 373     default:
 374         req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 375         break;
 376     }
 377
 378     return;
 379
 380 incorrect_lun:
 381     req->resp.tmf->response = VIRTIO_SCSI_S_INCORRECT_LUN;
 382     return;
 383
 384 fail:
 385     req->resp.tmf->response = VIRTIO_SCSI_S_BAD_TARGET;
 386 }
 387
 388 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 389 {
 390     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 391     VirtIOSCSIReq *req;
 392
 393     while ((req = virtio_scsi_pop_req(s, vq))) {
 394         int out_size, in_size;
 395         if (req->elem.out_num < 1 || req->elem.in_num < 1) {
 396             virtio_scsi_bad_req();
 397             continue;
 398         }
 399
 400         out_size = req->elem.out_sg[0].iov_len;
 401         in_size = req->elem.in_sg[0].iov_len;
 402         if (req->req.tmf->type == VIRTIO_SCSI_T_TMF) {
 403             if (out_size < sizeof(VirtIOSCSICtrlTMFReq) ||
 404                 in_size < sizeof(VirtIOSCSICtrlTMFResp)) {
 405                 virtio_scsi_bad_req();
 406             }
 407             virtio_scsi_do_tmf(s, req);
 408
 409         } else if (req->req.tmf->type == VIRTIO_SCSI_T_AN_QUERY ||
 410                    req->req.tmf->type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 411             if (out_size < sizeof(VirtIOSCSICtrlANReq) ||
 412                 in_size < sizeof(VirtIOSCSICtrlANResp)) {
 413                 virtio_scsi_bad_req();
 414             }
 415             req->resp.an->event_actual = 0;
 416             req->resp.an->response = VIRTIO_SCSI_S_OK;
 417         }
 418         virtio_scsi_complete_req(req);
 419     }
 420 }
 421
 422 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 423                                          size_t resid)
 424 {
 425     VirtIOSCSIReq *req = r->hba_private;
 426
 427     req->resp.cmd->response = VIRTIO_SCSI_S_OK;
 428     req->resp.cmd->status = status;
 429     if (req->resp.cmd->status == GOOD) {
 430         req->resp.cmd->resid = resid;
 431     } else {
 432         req->resp.cmd->resid = 0;
 433         req->resp.cmd->sense_len =
 434             scsi_req_get_sense(r, req->resp.cmd->sense, VIRTIO_SCSI_SENSE_SIZE);
 435     }
 436     virtio_scsi_complete_req(req);
 437 }
 438
 439 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 440 {
 441     VirtIOSCSIReq *req = r->hba_private;
 442
 443     return &req->qsgl;
 444 }
 445
 446 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 447 {
 448     VirtIOSCSIReq *req = r->hba_private;
 449
 450     if (!req) {
 451         return;
 452     }
 453     if (req->dev->resetting) {
 454         req->resp.cmd->response = VIRTIO_SCSI_S_RESET;
 455     } else {
 456         req->resp.cmd->response = VIRTIO_SCSI_S_ABORTED;
 457     }
 458     virtio_scsi_complete_req(req);
 459 }
 460
 461 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 462 {
 463     req->resp.cmd->response = VIRTIO_SCSI_S_FAILURE;
 464     virtio_scsi_complete_req(req);
 465 }
 466
 467 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 468 {
 469     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 470     VirtIOSCSIReq *req;
 471     int n;
 472
 473     while ((req = virtio_scsi_pop_req(s, vq))) {
 474         SCSIDevice *d;
 475         int out_size, in_size;
 476         if (req->elem.out_num < 1 || req->elem.in_num < 1) {
 477             virtio_scsi_bad_req();
 478         }
 479
 480         out_size = req->elem.out_sg[0].iov_len;
 481         in_size = req->elem.in_sg[0].iov_len;
 482         if (out_size < sizeof(VirtIOSCSICmdReq) + s->cdb_size ||
 483             in_size < sizeof(VirtIOSCSICmdResp) + s->sense_size) {
 484             virtio_scsi_bad_req();
 485         }
 486
 487         if (req->elem.out_num > 1 && req->elem.in_num > 1) {
 488             virtio_scsi_fail_cmd_req(req);
 489             continue;
 490         }
 491
 492         d = virtio_scsi_device_find(s, req->req.cmd->lun);
 493         if (!d) {
 494             req->resp.cmd->response = VIRTIO_SCSI_S_BAD_TARGET;
 495             virtio_scsi_complete_req(req);
 496             continue;
 497         }
 498         req->sreq = scsi_req_new(d, req->req.cmd->tag,
 499                                  virtio_scsi_get_lun(req->req.cmd->lun),
 500                                  req->req.cmd->cdb, req);
 501
 502         if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 503             int req_mode =
 504                 (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
 505
 506             if (req->sreq->cmd.mode != req_mode ||
 507                 req->sreq->cmd.xfer > req->qsgl.size) {
 508                 req->resp.cmd->response = VIRTIO_SCSI_S_OVERRUN;
 509                 virtio_scsi_complete_req(req);
 510                 continue;
 511             }
 512         }
 513
 514         n = scsi_req_enqueue(req->sreq);
 515         if (n) {
 516             scsi_req_continue(req->sreq);
 517         }
 518     }
 519 }
 520
 521 static void virtio_scsi_get_config(VirtIODevice *vdev,
 522                                    uint8_t *config)
 523 {
 524     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 525     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 526
 527     stl_raw(&scsiconf->num_queues, s->conf->num_queues);
 528     stl_raw(&scsiconf->seg_max, 128 - 2);
 529     stl_raw(&scsiconf->max_sectors, s->conf->max_sectors);
 530     stl_raw(&scsiconf->cmd_per_lun, s->conf->cmd_per_lun);
 531     stl_raw(&scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 532     stl_raw(&scsiconf->sense_size, s->sense_size);
 533     stl_raw(&scsiconf->cdb_size, s->cdb_size);
 534     stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 535     stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 536     stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 537 }
 538
 539 static void virtio_scsi_set_config(VirtIODevice *vdev,
 540                                    const uint8_t *config)
 541 {
 542     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 543     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 544
 545     if ((uint32_t) ldl_raw(&scsiconf->sense_size) >= 65536 ||
 546         (uint32_t) ldl_raw(&scsiconf->cdb_size) >= 256) {
 547         error_report("bad data written to virtio-scsi configuration space");
 548         exit(1);
 549     }
 550
 551     s->sense_size = ldl_raw(&scsiconf->sense_size);
 552     s->cdb_size = ldl_raw(&scsiconf->cdb_size);
 553 }
 554
 555 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
 556                                          uint32_t requested_features)
 557 {
 558     requested_features |= (1UL << VIRTIO_SCSI_F_HOTPLUG);
 559     requested_features |= (1UL << VIRTIO_SCSI_F_CHANGE);
 560     return requested_features;
 561 }
 562
 563 static void virtio_scsi_reset(VirtIODevice *vdev)
 564 {
 565     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 566
 567     s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
 568     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 569     s->events_dropped = false;
 570 }
 571
 572 /* The device does not have anything to save beyond the virtio data.
 573  * Request data is saved with callbacks from SCSI devices.
 574  */
 575 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 576 {
 577     VirtIOSCSI *s = opaque;
 578     virtio_save(&s->vdev, f);
 579 }
 580
 581 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 582 {
 583     VirtIOSCSI *s = opaque;
 584     int ret;
 585
 586     ret = virtio_load(&s->vdev, f);
 587     if (ret) {
 588         return ret;
 589     }
 590     return 0;
 591 }
 592
 593 static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 594                                    uint32_t event, uint32_t reason)
 595 {
 596     VirtIOSCSIReq *req = virtio_scsi_pop_req(s, s->event_vq);
 597     VirtIOSCSIEvent *evt;
 598     int in_size;
 599
 600     if (!req) {
 601         s->events_dropped = true;
 602         return;
 603     }
 604
 605     if (req->elem.out_num || req->elem.in_num != 1) {
 606         virtio_scsi_bad_req();
 607     }
 608
 609     if (s->events_dropped) {
 610         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 611         s->events_dropped = false;
 612     }
 613
 614     in_size = req->elem.in_sg[0].iov_len;
 615     if (in_size < sizeof(VirtIOSCSIEvent)) {
 616         virtio_scsi_bad_req();
 617     }
 618
 619     evt = req->resp.event;
 620     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 621     evt->event = event;
 622     evt->reason = reason;
 623     if (!dev) {
 624         assert(event == VIRTIO_SCSI_T_NO_EVENT);
 625     } else {
 626         evt->lun[0] = 1;
 627         evt->lun[1] = dev->id;
 628
 629         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 630         if (dev->lun >= 256) {
 631             evt->lun[2] = (dev->lun >> 8) | 0x40;
 632         }
 633         evt->lun[3] = dev->lun & 0xFF;
 634     }
 635     virtio_scsi_complete_req(req);
 636 }
 637
 638 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 639 {
 640     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 641
 642     if (s->events_dropped) {
 643         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 644     }
 645 }
 646
 647 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 648 {
 649     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 650
 651     if (((s->vdev.guest_features >> VIRTIO_SCSI_F_CHANGE) & 1) &&
 652         (s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) &&
 653         dev->type != TYPE_ROM) {
 654         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 655                                sense.asc | (sense.ascq << 8));
 656     }
 657 }
 658
 659 static void virtio_scsi_hotplug(SCSIBus *bus, SCSIDevice *dev)
 660 {
 661     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 662
 663     if (((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) &&
 664         (s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 665         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
 666                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 667     }
 668 }
 669
 670 static void virtio_scsi_hot_unplug(SCSIBus *bus, SCSIDevice *dev)
 671 {
 672     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 673
 674     if ((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
 675         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
 676                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 677     }
 678 }
 679
 680 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 681     .tcq = true,
 682     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 683     .max_target = VIRTIO_SCSI_MAX_TARGET,
 684     .max_lun = VIRTIO_SCSI_MAX_LUN,
 685
 686     .complete = virtio_scsi_command_complete,
 687     .cancel = virtio_scsi_request_cancelled,
 688     .change = virtio_scsi_change,
 689     .hotplug = virtio_scsi_hotplug,
 690     .hot_unplug = virtio_scsi_hot_unplug,
 691     .get_sg_list = virtio_scsi_get_sg_list,
 692     .save_request = virtio_scsi_save_request,
 693     .load_request = virtio_scsi_load_request,
 694 };
 695
 696 VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf)
 697 {
 698     VirtIOSCSI *s;
 699     static int virtio_scsi_id;
 700     size_t sz;
 701     int i;
 702
 703     sz = sizeof(VirtIOSCSI) + proxyconf->num_queues * sizeof(VirtQueue *);
 704     s = (VirtIOSCSI *)virtio_common_init("virtio-scsi", VIRTIO_ID_SCSI,
 705                                          sizeof(VirtIOSCSIConfig), sz);
 706
 707     s->qdev = dev;
 708     s->conf = proxyconf;
 709
 710     /* TODO set up vdev function pointers */
 711     s->vdev.get_config = virtio_scsi_get_config;
 712     s->vdev.set_config = virtio_scsi_set_config;
 713     s->vdev.get_features = virtio_scsi_get_features;
 714     s->vdev.reset = virtio_scsi_reset;
 715
 716     s->ctrl_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 717                                    virtio_scsi_handle_ctrl);
 718     s->event_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 719                                    virtio_scsi_handle_event);
 720     for (i = 0; i < s->conf->num_queues; i++) {
 721         s->cmd_vqs[i] = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 722                                          virtio_scsi_handle_cmd);
 723     }
 724
 725     scsi_bus_new(&s->bus, dev, &virtio_scsi_scsi_info);
 726     if (!dev->hotplugged) {
 727         scsi_bus_legacy_handle_cmdline(&s->bus);
 728     }
 729
 730     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 731                     virtio_scsi_save, virtio_scsi_load, s);
 732
 733     return &s->vdev;
 734 }
 735
 736 void virtio_scsi_exit(VirtIODevice *vdev)
 737 {
 738     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 739     unregister_savevm(s->qdev, "virtio-scsi", s);
 740     virtio_cleanup(vdev);
 741 }