[qemu.git] / hw / virtio-scsi.c

/*
 * Virtio SCSI HBA
 *
 * Copyright IBM, Corp. 2010
 * Copyright Red Hat, Inc. 2011
 *
 * Authors:
 *   Stefan Hajnoczi    <[email protected]>
 *   Paolo Bonzini      <[email protected]>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 *
 */

#include "virtio-scsi.h"
#include <hw/scsi.h>
#include <hw/scsi-defs.h>

#define VIRTIO_SCSI_VQ_SIZE     128
#define VIRTIO_SCSI_CDB_SIZE    32
#define VIRTIO_SCSI_SENSE_SIZE  96
#define VIRTIO_SCSI_MAX_CHANNEL 0
#define VIRTIO_SCSI_MAX_TARGET  255
#define VIRTIO_SCSI_MAX_LUN     16383

/* Feature Bits */
#define VIRTIO_SCSI_F_INOUT                    0
#define VIRTIO_SCSI_F_HOTPLUG                  1

/* Response codes */
#define VIRTIO_SCSI_S_OK                       0
#define VIRTIO_SCSI_S_OVERRUN                  1
#define VIRTIO_SCSI_S_ABORTED                  2
#define VIRTIO_SCSI_S_BAD_TARGET               3
#define VIRTIO_SCSI_S_RESET                    4
#define VIRTIO_SCSI_S_BUSY                     5
#define VIRTIO_SCSI_S_TRANSPORT_FAILURE        6
#define VIRTIO_SCSI_S_TARGET_FAILURE           7
#define VIRTIO_SCSI_S_NEXUS_FAILURE            8
#define VIRTIO_SCSI_S_FAILURE                  9
#define VIRTIO_SCSI_S_FUNCTION_SUCCEEDED       10
#define VIRTIO_SCSI_S_FUNCTION_REJECTED        11
#define VIRTIO_SCSI_S_INCORRECT_LUN            12

/* Controlq type codes.  */
#define VIRTIO_SCSI_T_TMF                      0
#define VIRTIO_SCSI_T_AN_QUERY                 1
#define VIRTIO_SCSI_T_AN_SUBSCRIBE             2

/* Valid TMF subtypes.  */
#define VIRTIO_SCSI_T_TMF_ABORT_TASK           0
#define VIRTIO_SCSI_T_TMF_ABORT_TASK_SET       1
#define VIRTIO_SCSI_T_TMF_CLEAR_ACA            2
#define VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET       3
#define VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET      4
#define VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET   5
#define VIRTIO_SCSI_T_TMF_QUERY_TASK           6
#define VIRTIO_SCSI_T_TMF_QUERY_TASK_SET       7

/* Events.  */
#define VIRTIO_SCSI_T_EVENTS_MISSED            0x80000000
#define VIRTIO_SCSI_T_NO_EVENT                 0
#define VIRTIO_SCSI_T_TRANSPORT_RESET          1
#define VIRTIO_SCSI_T_ASYNC_NOTIFY             2

/* Reasons for transport reset event */
#define VIRTIO_SCSI_EVT_RESET_HARD             0
#define VIRTIO_SCSI_EVT_RESET_RESCAN           1
#define VIRTIO_SCSI_EVT_RESET_REMOVED          2

/* SCSI command request, followed by data-out */
typedef struct {
    uint8_t lun[8];              /* Logical Unit Number */
    uint64_t tag;                /* Command identifier */
    uint8_t task_attr;           /* Task attribute */
    uint8_t prio;
    uint8_t crn;
    uint8_t cdb[];
} QEMU_PACKED VirtIOSCSICmdReq;

/* Response, followed by sense data and data-in */
typedef struct {
    uint32_t sense_len;          /* Sense data length */
    uint32_t resid;              /* Residual bytes in data buffer */
    uint16_t status_qualifier;   /* Status qualifier */
    uint8_t status;              /* Command completion status */
    uint8_t response;            /* Response values */
    uint8_t sense[];
} QEMU_PACKED VirtIOSCSICmdResp;

/* Task Management Request */
typedef struct {
    uint32_t type;
    uint32_t subtype;
    uint8_t lun[8];
    uint64_t tag;
} QEMU_PACKED VirtIOSCSICtrlTMFReq;

typedef struct {
    uint8_t response;
} QEMU_PACKED VirtIOSCSICtrlTMFResp;

/* Asynchronous notification query/subscription */
typedef struct {
    uint32_t type;
    uint8_t lun[8];
    uint32_t event_requested;
} QEMU_PACKED VirtIOSCSICtrlANReq;

typedef struct {
    uint32_t event_actual;
    uint8_t response;
} QEMU_PACKED VirtIOSCSICtrlANResp;

typedef struct {
    uint32_t event;
    uint8_t lun[8];
    uint32_t reason;
} QEMU_PACKED VirtIOSCSIEvent;

typedef struct {
    uint32_t num_queues;
    uint32_t seg_max;
    uint32_t max_sectors;
    uint32_t cmd_per_lun;
    uint32_t event_info_size;
    uint32_t sense_size;
    uint32_t cdb_size;
    uint16_t max_channel;
    uint16_t max_target;
    uint32_t max_lun;
} QEMU_PACKED VirtIOSCSIConfig;

typedef struct {
    VirtIODevice vdev;
    DeviceState *qdev;
    VirtIOSCSIConf *conf;

    SCSIBus bus;
    uint32_t sense_size;
    uint32_t cdb_size;
    int resetting;
    bool events_dropped;
    VirtQueue *ctrl_vq;
    VirtQueue *event_vq;
    VirtQueue *cmd_vqs[0];
} VirtIOSCSI;

typedef struct VirtIOSCSIReq {
    VirtIOSCSI *dev;
    VirtQueue *vq;
    VirtQueueElement elem;
    QEMUSGList qsgl;
    SCSIRequest *sreq;
    union {
        char                  *buf;
        VirtIOSCSICmdReq      *cmd;
        VirtIOSCSICtrlTMFReq  *tmf;
        VirtIOSCSICtrlANReq   *an;
    } req;
    union {
        char                  *buf;
        VirtIOSCSICmdResp     *cmd;
        VirtIOSCSICtrlTMFResp *tmf;
        VirtIOSCSICtrlANResp  *an;
        VirtIOSCSIEvent       *event;
    } resp;
} VirtIOSCSIReq;

static inline int virtio_scsi_get_lun(uint8_t *lun)
{
    return ((lun[2] << 8) | lun[3]) & 0x3FFF;
}

static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
{
    if (lun[0] != 1) {
        return NULL;
    }
    if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
        return NULL;
    }
    return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
}

static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
{
    VirtIOSCSI *s = req->dev;
    VirtQueue *vq = req->vq;
    virtqueue_push(vq, &req->elem, req->qsgl.size + req->elem.in_sg[0].iov_len);
    qemu_sglist_destroy(&req->qsgl);
    if (req->sreq) {
        req->sreq->hba_private = NULL;
        scsi_req_unref(req->sreq);
    }
    g_free(req);
    virtio_notify(&s->vdev, vq);
}

static void virtio_scsi_bad_req(void)
{
    error_report("wrong size for virtio-scsi headers");
    exit(1);
}

static void qemu_sgl_init_external(QEMUSGList *qsgl, struct iovec *sg,
                                   target_phys_addr_t *addr, int num)
{
    memset(qsgl, 0, sizeof(*qsgl));
    while (num--) {
        qemu_sglist_add(qsgl, *(addr++), (sg++)->iov_len);
    }
}

static void virtio_scsi_parse_req(VirtIOSCSI *s, VirtQueue *vq,
                                  VirtIOSCSIReq *req)
{
    assert(req->elem.in_num);
    req->vq = vq;
    req->dev = s;
    req->sreq = NULL;
    if (req->elem.out_num) {
        req->req.buf = req->elem.out_sg[0].iov_base;
    }
    req->resp.buf = req->elem.in_sg[0].iov_base;

    if (req->elem.out_num > 1) {
        qemu_sgl_init_external(&req->qsgl, &req->elem.out_sg[1],
                               &req->elem.out_addr[1],
                               req->elem.out_num - 1);
    } else {
        qemu_sgl_init_external(&req->qsgl, &req->elem.in_sg[1],
                               &req->elem.in_addr[1],
                               req->elem.in_num - 1);
    }
}

static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
{
    VirtIOSCSIReq *req;
    req = g_malloc(sizeof(*req));
    if (!virtqueue_pop(vq, &req->elem)) {
        g_free(req);
        return NULL;
    }

    virtio_scsi_parse_req(s, vq, req);
    return req;
}

static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
{
    VirtIOSCSIReq *req = sreq->hba_private;
    uint32_t n = virtio_queue_get_id(req->vq) - 2;

    assert(n < req->dev->conf->num_queues);
    qemu_put_be32s(f, &n);
    qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
}

static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
{
    SCSIBus *bus = sreq->bus;
    VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
    VirtIOSCSIReq *req;
    uint32_t n;

    req = g_malloc(sizeof(*req));
    qemu_get_be32s(f, &n);
    assert(n < s->conf->num_queues);
    qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
    virtio_scsi_parse_req(s, s->cmd_vqs[n], req);

    scsi_req_ref(sreq);
    req->sreq = sreq;
    if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
        int req_mode =
            (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);

        assert(req->sreq->cmd.mode == req_mode);
    }
    return req;
}

static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
    SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf->lun);
    SCSIRequest *r, *next;
    BusChild *kid;
    int target;

    /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
    req->resp.tmf->response = VIRTIO_SCSI_S_OK;

    switch (req->req.tmf->subtype) {
    case VIRTIO_SCSI_T_TMF_ABORT_TASK:
    case VIRTIO_SCSI_T_TMF_QUERY_TASK:
        if (!d) {
            goto fail;
        }
        if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
            goto incorrect_lun;
        }
        QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
            if (r->tag == req->req.tmf->tag) {
                break;
            }
        }
        if (r && r->hba_private) {
            if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
                /* "If the specified command is present in the task set, then
                 * return a service response set to FUNCTION SUCCEEDED".
                 */
                req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
            } else {
                scsi_req_cancel(r);
            }
        }
        break;

    case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
        if (!d) {
            goto fail;
        }
        if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
            goto incorrect_lun;
        }
        s->resetting++;
        qdev_reset_all(&d->qdev);
        s->resetting--;
        break;

    case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
    case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
    case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
        if (!d) {
            goto fail;
        }
        if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
            goto incorrect_lun;
        }
        QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
            if (r->hba_private) {
                if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
                    /* "If there is any command present in the task set, then
                     * return a service response set to FUNCTION SUCCEEDED".
                     */
                    req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
                    break;
                } else {
                    scsi_req_cancel(r);
                }
            }
        }
        break;

    case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
        target = req->req.tmf->lun[1];
        s->resetting++;
        QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
             d = DO_UPCAST(SCSIDevice, qdev, kid->child);
             if (d->channel == 0 && d->id == target) {
                qdev_reset_all(&d->qdev);
             }
        }
        s->resetting--;
        break;

    case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
    default:
        req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
        break;
    }

    return;

incorrect_lun:
    req->resp.tmf->response = VIRTIO_SCSI_S_INCORRECT_LUN;
    return;

fail:
    req->resp.tmf->response = VIRTIO_SCSI_S_BAD_TARGET;
}

static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
{
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
    VirtIOSCSIReq *req;

    while ((req = virtio_scsi_pop_req(s, vq))) {
        int out_size, in_size;
        if (req->elem.out_num < 1 || req->elem.in_num < 1) {
            virtio_scsi_bad_req();
            continue;
        }

        out_size = req->elem.out_sg[0].iov_len;
        in_size = req->elem.in_sg[0].iov_len;
        if (req->req.tmf->type == VIRTIO_SCSI_T_TMF) {
            if (out_size < sizeof(VirtIOSCSICtrlTMFReq) ||
                in_size < sizeof(VirtIOSCSICtrlTMFResp)) {
                virtio_scsi_bad_req();
            }
            virtio_scsi_do_tmf(s, req);

        } else if (req->req.tmf->type == VIRTIO_SCSI_T_AN_QUERY ||
                   req->req.tmf->type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
            if (out_size < sizeof(VirtIOSCSICtrlANReq) ||
                in_size < sizeof(VirtIOSCSICtrlANResp)) {
                virtio_scsi_bad_req();
            }
            req->resp.an->event_actual = 0;
            req->resp.an->response = VIRTIO_SCSI_S_OK;
        }
        virtio_scsi_complete_req(req);
    }
}

static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
                                         size_t resid)
{
    VirtIOSCSIReq *req = r->hba_private;

    req->resp.cmd->response = VIRTIO_SCSI_S_OK;
    req->resp.cmd->status = status;
    if (req->resp.cmd->status == GOOD) {
        req->resp.cmd->resid = resid;
    } else {
        req->resp.cmd->resid = 0;
        req->resp.cmd->sense_len =
            scsi_req_get_sense(r, req->resp.cmd->sense, VIRTIO_SCSI_SENSE_SIZE);
    }
    virtio_scsi_complete_req(req);
}

static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
{
    VirtIOSCSIReq *req = r->hba_private;

    return &req->qsgl;
}

static void virtio_scsi_request_cancelled(SCSIRequest *r)
{
    VirtIOSCSIReq *req = r->hba_private;

    if (!req) {
        return;
    }
    if (req->dev->resetting) {
        req->resp.cmd->response = VIRTIO_SCSI_S_RESET;
    } else {
        req->resp.cmd->response = VIRTIO_SCSI_S_ABORTED;
    }
    virtio_scsi_complete_req(req);
}

static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
{
    req->resp.cmd->response = VIRTIO_SCSI_S_FAILURE;
    virtio_scsi_complete_req(req);
}

static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
{
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
    VirtIOSCSIReq *req;
    int n;

    while ((req = virtio_scsi_pop_req(s, vq))) {
        SCSIDevice *d;
        int out_size, in_size;
        if (req->elem.out_num < 1 || req->elem.in_num < 1) {
            virtio_scsi_bad_req();
        }

        out_size = req->elem.out_sg[0].iov_len;
        in_size = req->elem.in_sg[0].iov_len;
        if (out_size < sizeof(VirtIOSCSICmdReq) + s->cdb_size ||
            in_size < sizeof(VirtIOSCSICmdResp) + s->sense_size) {
            virtio_scsi_bad_req();
        }

        if (req->elem.out_num > 1 && req->elem.in_num > 1) {
            virtio_scsi_fail_cmd_req(req);
            continue;
        }

        d = virtio_scsi_device_find(s, req->req.cmd->lun);
        if (!d) {
            req->resp.cmd->response = VIRTIO_SCSI_S_BAD_TARGET;
            virtio_scsi_complete_req(req);
            continue;
        }
        req->sreq = scsi_req_new(d, req->req.cmd->tag,
                                 virtio_scsi_get_lun(req->req.cmd->lun),
                                 req->req.cmd->cdb, req);

        if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
            int req_mode =
                (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);

            if (req->sreq->cmd.mode != req_mode ||
                req->sreq->cmd.xfer > req->qsgl.size) {
                req->resp.cmd->response = VIRTIO_SCSI_S_OVERRUN;
                virtio_scsi_complete_req(req);
                continue;
            }
        }

        n = scsi_req_enqueue(req->sreq);
        if (n) {
            scsi_req_continue(req->sreq);
        }
    }
}

static void virtio_scsi_get_config(VirtIODevice *vdev,
                                   uint8_t *config)
{
    VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;

    stl_raw(&scsiconf->num_queues, s->conf->num_queues);
    stl_raw(&scsiconf->seg_max, 128 - 2);
    stl_raw(&scsiconf->max_sectors, s->conf->max_sectors);
    stl_raw(&scsiconf->cmd_per_lun, s->conf->cmd_per_lun);
    stl_raw(&scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
    stl_raw(&scsiconf->sense_size, s->sense_size);
    stl_raw(&scsiconf->cdb_size, s->cdb_size);
    stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
    stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
    stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
}

static void virtio_scsi_set_config(VirtIODevice *vdev,
                                   const uint8_t *config)
{
    VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;

    if ((uint32_t) ldl_raw(&scsiconf->sense_size) >= 65536 ||
        (uint32_t) ldl_raw(&scsiconf->cdb_size) >= 256) {
        error_report("bad data written to virtio-scsi configuration space");
        exit(1);
    }

    s->sense_size = ldl_raw(&scsiconf->sense_size);
    s->cdb_size = ldl_raw(&scsiconf->cdb_size);
}

static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
                                         uint32_t requested_features)
{
    requested_features |= (1UL << VIRTIO_SCSI_F_HOTPLUG);
    return requested_features;
}

static void virtio_scsi_reset(VirtIODevice *vdev)
{
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;

    s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
    s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
    s->events_dropped = false;
}

/* The device does not have anything to save beyond the virtio data.
 * Request data is saved with callbacks from SCSI devices.
 */
static void virtio_scsi_save(QEMUFile *f, void *opaque)
{
    VirtIOSCSI *s = opaque;
    virtio_save(&s->vdev, f);
}

static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
{
    VirtIOSCSI *s = opaque;
    int ret;

    ret = virtio_load(&s->vdev, f);
    if (ret) {
        return ret;
    }
    return 0;
}

static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
                                   uint32_t event, uint32_t reason)
{
    VirtIOSCSIReq *req = virtio_scsi_pop_req(s, s->event_vq);
    VirtIOSCSIEvent *evt;
    int in_size;

    if (!req) {
        s->events_dropped = true;
        return;
    }

    if (req->elem.out_num || req->elem.in_num != 1) {
        virtio_scsi_bad_req();
    }

    if (s->events_dropped) {
        event |= VIRTIO_SCSI_T_EVENTS_MISSED;
        s->events_dropped = false;
    }

    in_size = req->elem.in_sg[0].iov_len;
    if (in_size < sizeof(VirtIOSCSIEvent)) {
        virtio_scsi_bad_req();
    }

    evt = req->resp.event;
    memset(evt, 0, sizeof(VirtIOSCSIEvent));
    evt->event = event;
    evt->reason = reason;
    if (!dev) {
        assert(event == VIRTIO_SCSI_T_NO_EVENT);
    } else {
        evt->lun[0] = 1;
        evt->lun[1] = dev->id;

        /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
        if (dev->lun >= 256) {
            evt->lun[2] = (dev->lun >> 8) | 0x40;
        }
        evt->lun[3] = dev->lun & 0xFF;
    }
    virtio_scsi_complete_req(req);
}

static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
{
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;

    if (s->events_dropped) {
        virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
    }
}

static void virtio_scsi_hotplug(SCSIBus *bus, SCSIDevice *dev)
{
    VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);

    if (((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) &&
        (s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
        virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
                               VIRTIO_SCSI_EVT_RESET_RESCAN);
    }
}

static void virtio_scsi_hot_unplug(SCSIBus *bus, SCSIDevice *dev)
{
    VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);

    if ((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
        virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
                               VIRTIO_SCSI_EVT_RESET_REMOVED);
    }
}

static struct SCSIBusInfo virtio_scsi_scsi_info = {
    .tcq = true,
    .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
    .max_target = VIRTIO_SCSI_MAX_TARGET,
    .max_lun = VIRTIO_SCSI_MAX_LUN,

    .complete = virtio_scsi_command_complete,
    .cancel = virtio_scsi_request_cancelled,
    .hotplug = virtio_scsi_hotplug,
    .hot_unplug = virtio_scsi_hot_unplug,
    .get_sg_list = virtio_scsi_get_sg_list,
    .save_request = virtio_scsi_save_request,
    .load_request = virtio_scsi_load_request,
};

VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf)
{
    VirtIOSCSI *s;
    static int virtio_scsi_id;
    size_t sz;
    int i;

    sz = sizeof(VirtIOSCSI) + proxyconf->num_queues * sizeof(VirtQueue *);
    s = (VirtIOSCSI *)virtio_common_init("virtio-scsi", VIRTIO_ID_SCSI,
                                         sizeof(VirtIOSCSIConfig), sz);

    s->qdev = dev;
    s->conf = proxyconf;

    /* TODO set up vdev function pointers */
    s->vdev.get_config = virtio_scsi_get_config;
    s->vdev.set_config = virtio_scsi_set_config;
    s->vdev.get_features = virtio_scsi_get_features;
    s->vdev.reset = virtio_scsi_reset;

    s->ctrl_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
                                   virtio_scsi_handle_ctrl);
    s->event_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
                                   virtio_scsi_handle_event);
    for (i = 0; i < s->conf->num_queues; i++) {
        s->cmd_vqs[i] = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
                                         virtio_scsi_handle_cmd);
    }

    scsi_bus_new(&s->bus, dev, &virtio_scsi_scsi_info);
    if (!dev->hotplugged) {
        scsi_bus_legacy_handle_cmdline(&s->bus);
    }

    register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
                    virtio_scsi_save, virtio_scsi_load, s);

    return &s->vdev;
}

void virtio_scsi_exit(VirtIODevice *vdev)
{
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
    unregister_savevm(s->qdev, "virtio-scsi", s);
    virtio_cleanup(vdev);
}
Commit	Line	Data
973abc7f SH	1	/*
	2	* Virtio SCSI HBA
	3	*
	4	* Copyright IBM, Corp. 2010
	5	* Copyright Red Hat, Inc. 2011
	6	*
	7	* Authors:
	8	* Stefan Hajnoczi <[email protected]>
	9	* Paolo Bonzini <[email protected]>
	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
b6866fee CM	27	/* Feature Bits */
	28	#define VIRTIO_SCSI_F_INOUT 0
	29	#define VIRTIO_SCSI_F_HOTPLUG 1
	30
973abc7f SH	31	/* Response codes */
	32	#define VIRTIO_SCSI_S_OK 0
	33	#define VIRTIO_SCSI_S_OVERRUN 1
	34	#define VIRTIO_SCSI_S_ABORTED 2
	35	#define VIRTIO_SCSI_S_BAD_TARGET 3
	36	#define VIRTIO_SCSI_S_RESET 4
	37	#define VIRTIO_SCSI_S_BUSY 5
	38	#define VIRTIO_SCSI_S_TRANSPORT_FAILURE 6
	39	#define VIRTIO_SCSI_S_TARGET_FAILURE 7
	40	#define VIRTIO_SCSI_S_NEXUS_FAILURE 8
	41	#define VIRTIO_SCSI_S_FAILURE 9
	42	#define VIRTIO_SCSI_S_FUNCTION_SUCCEEDED 10
	43	#define VIRTIO_SCSI_S_FUNCTION_REJECTED 11
	44	#define VIRTIO_SCSI_S_INCORRECT_LUN 12
	45
	46	/* Controlq type codes. */
	47	#define VIRTIO_SCSI_T_TMF 0
	48	#define VIRTIO_SCSI_T_AN_QUERY 1
	49	#define VIRTIO_SCSI_T_AN_SUBSCRIBE 2
	50
	51	/* Valid TMF subtypes. */
	52	#define VIRTIO_SCSI_T_TMF_ABORT_TASK 0
	53	#define VIRTIO_SCSI_T_TMF_ABORT_TASK_SET 1
	54	#define VIRTIO_SCSI_T_TMF_CLEAR_ACA 2
	55	#define VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET 3
	56	#define VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET 4
	57	#define VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET 5
	58	#define VIRTIO_SCSI_T_TMF_QUERY_TASK 6
	59	#define VIRTIO_SCSI_T_TMF_QUERY_TASK_SET 7
	60
	61	/* Events. */
	62	#define VIRTIO_SCSI_T_EVENTS_MISSED 0x80000000
	63	#define VIRTIO_SCSI_T_NO_EVENT 0
	64	#define VIRTIO_SCSI_T_TRANSPORT_RESET 1
	65	#define VIRTIO_SCSI_T_ASYNC_NOTIFY 2
	66
b6866fee CM	67	/* Reasons for transport reset event */
	68	#define VIRTIO_SCSI_EVT_RESET_HARD 0
	69	#define VIRTIO_SCSI_EVT_RESET_RESCAN 1
	70	#define VIRTIO_SCSI_EVT_RESET_REMOVED 2
	71
973abc7f SH	72	/* SCSI command request, followed by data-out */
	73	typedef struct {
	74	uint8_t lun[8]; /* Logical Unit Number */
	75	uint64_t tag; /* Command identifier */
	76	uint8_t task_attr; /* Task attribute */
	77	uint8_t prio;
	78	uint8_t crn;
	79	uint8_t cdb[];
	80	} QEMU_PACKED VirtIOSCSICmdReq;
	81
	82	/* Response, followed by sense data and data-in */
	83	typedef struct {
	84	uint32_t sense_len; /* Sense data length */
	85	uint32_t resid; /* Residual bytes in data buffer */
	86	uint16_t status_qualifier; /* Status qualifier */
	87	uint8_t status; /* Command completion status */
	88	uint8_t response; /* Response values */
	89	uint8_t sense[];
	90	} QEMU_PACKED VirtIOSCSICmdResp;
	91
	92	/* Task Management Request */
	93	typedef struct {
	94	uint32_t type;
	95	uint32_t subtype;
	96	uint8_t lun[8];
	97	uint64_t tag;
	98	} QEMU_PACKED VirtIOSCSICtrlTMFReq;
	99
	100	typedef struct {
	101	uint8_t response;
	102	} QEMU_PACKED VirtIOSCSICtrlTMFResp;
	103
	104	/* Asynchronous notification query/subscription */
	105	typedef struct {
	106	uint32_t type;
	107	uint8_t lun[8];
	108	uint32_t event_requested;
	109	} QEMU_PACKED VirtIOSCSICtrlANReq;
	110
	111	typedef struct {
	112	uint32_t event_actual;
	113	uint8_t response;
	114	} QEMU_PACKED VirtIOSCSICtrlANResp;
	115
	116	typedef struct {
	117	uint32_t event;
	118	uint8_t lun[8];
	119	uint32_t reason;
	120	} QEMU_PACKED VirtIOSCSIEvent;
	121
	122	typedef struct {
	123	uint32_t num_queues;
	124	uint32_t seg_max;
	125	uint32_t max_sectors;
	126	uint32_t cmd_per_lun;
	127	uint32_t event_info_size;
	128	uint32_t sense_size;
	129	uint32_t cdb_size;
	130	uint16_t max_channel;
	131	uint16_t max_target;
	132	uint32_t max_lun;
	133	} QEMU_PACKED VirtIOSCSIConfig;
	134
	135	typedef struct {
136	VirtIODevice vdev;
137	DeviceState *qdev;
138	VirtIOSCSIConf *conf;
139
2ccdcd8d	140	SCSIBus bus;
973abc7f SH	141	uint32_t sense_size;
973abc7f SH	142	uint32_t cdb_size;
06114d72	143	int resetting;
64f64855	144	bool events_dropped;
d2ad7dd4 PB	145	VirtQueue *ctrl_vq;
	146	VirtQueue *event_vq;
	147	VirtQueue *cmd_vqs[0];
973abc7f SH	148	} VirtIOSCSI;
973abc7f SH	149
326799c0 SH	150	typedef struct VirtIOSCSIReq {
	151	VirtIOSCSI *dev;
	152	VirtQueue *vq;
	153	VirtQueueElement elem;
	154	QEMUSGList qsgl;
	155	SCSIRequest *sreq;
	156	union {
	157	char *buf;
	158	VirtIOSCSICmdReq *cmd;
	159	VirtIOSCSICtrlTMFReq *tmf;
	160	VirtIOSCSICtrlANReq *an;
	161	} req;
	162	union {
	163	char *buf;
	164	VirtIOSCSICmdResp *cmd;
	165	VirtIOSCSICtrlTMFResp *tmf;
	166	VirtIOSCSICtrlANResp *an;
	167	VirtIOSCSIEvent *event;
	168	} resp;
	169	} VirtIOSCSIReq;
	170
2ccdcd8d PB	171	static inline int virtio_scsi_get_lun(uint8_t *lun)
	172	{
	173	return ((lun[2] << 8) \| lun[3]) & 0x3FFF;
	174	}
	175
	176	static inline SCSIDevice virtio_scsi_device_find(VirtIOSCSI s, uint8_t *lun)
	177	{
	178	if (lun[0] != 1) {
	179	return NULL;
	180	}
	181	if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
	182	return NULL;
	183	}
	184	return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
	185	}
	186
326799c0 SH	187	static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
	188	{
	189	VirtIOSCSI *s = req->dev;
	190	VirtQueue *vq = req->vq;
	191	virtqueue_push(vq, &req->elem, req->qsgl.size + req->elem.in_sg[0].iov_len);
	192	qemu_sglist_destroy(&req->qsgl);
	193	if (req->sreq) {
	194	req->sreq->hba_private = NULL;
	195	scsi_req_unref(req->sreq);
	196	}
	197	g_free(req);
	198	virtio_notify(&s->vdev, vq);
	199	}
	200
	201	static void virtio_scsi_bad_req(void)
	202	{
	203	error_report("wrong size for virtio-scsi headers");
	204	exit(1);
	205	}
	206
	207	static void qemu_sgl_init_external(QEMUSGList qsgl, struct iovec sg,
	208	target_phys_addr_t *addr, int num)
	209	{
	210	memset(qsgl, 0, sizeof(*qsgl));
	211	while (num--) {
	212	qemu_sglist_add(qsgl, *(addr++), (sg++)->iov_len);
	213	}
	214	}
	215
	216	static void virtio_scsi_parse_req(VirtIOSCSI s, VirtQueue vq,
	217	VirtIOSCSIReq *req)
	218	{
b6866fee	219	assert(req->elem.in_num);
326799c0 SH	220	req->vq = vq;
	221	req->dev = s;
	222	req->sreq = NULL;
b6866fee CM	223	if (req->elem.out_num) {
	224	req->req.buf = req->elem.out_sg[0].iov_base;
	225	}
326799c0 SH	226	req->resp.buf = req->elem.in_sg[0].iov_base;
	227
	228	if (req->elem.out_num > 1) {
	229	qemu_sgl_init_external(&req->qsgl, &req->elem.out_sg[1],
	230	&req->elem.out_addr[1],
	231	req->elem.out_num - 1);
	232	} else {
	233	qemu_sgl_init_external(&req->qsgl, &req->elem.in_sg[1],
	234	&req->elem.in_addr[1],
	235	req->elem.in_num - 1);
	236	}
	237	}
	238
	239	static VirtIOSCSIReq virtio_scsi_pop_req(VirtIOSCSI s, VirtQueue *vq)
	240	{
	241	VirtIOSCSIReq *req;
	242	req = g_malloc(sizeof(*req));
	243	if (!virtqueue_pop(vq, &req->elem)) {
	244	g_free(req);
	245	return NULL;
	246	}
	247
	248	virtio_scsi_parse_req(s, vq, req);
	249	return req;
	250	}
	251
5db1764c PB	252	static void virtio_scsi_save_request(QEMUFile f, SCSIRequest sreq)
	253	{
	254	VirtIOSCSIReq *req = sreq->hba_private;
d2ad7dd4	255	uint32_t n = virtio_queue_get_id(req->vq) - 2;
5db1764c	256
d2ad7dd4	257	assert(n < req->dev->conf->num_queues);
fcf104a7	258	qemu_put_be32s(f, &n);
5db1764c PB	259	qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
	260	}
	261
	262	static void virtio_scsi_load_request(QEMUFile f, SCSIRequest *sreq)
	263	{
	264	SCSIBus *bus = sreq->bus;
	265	VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
	266	VirtIOSCSIReq *req;
fcf104a7	267	uint32_t n;
5db1764c PB	268
5db1764c PB	269	req = g_malloc(sizeof(*req));
fcf104a7	270	qemu_get_be32s(f, &n);
d2ad7dd4	271	assert(n < s->conf->num_queues);
5db1764c	272	qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
d2ad7dd4	273	virtio_scsi_parse_req(s, s->cmd_vqs[n], req);
5db1764c PB	274
	275	scsi_req_ref(sreq);
	276	req->sreq = sreq;
	277	if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
	278	int req_mode =
	279	(req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
	280
	281	assert(req->sreq->cmd.mode == req_mode);
	282	}
	283	return req;
	284	}
	285
06114d72	286	static void virtio_scsi_do_tmf(VirtIOSCSI s, VirtIOSCSIReq req)
326799c0	287	{
06114d72 PB	288	SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf->lun);
06114d72 PB	289	SCSIRequest r, next;
0866aca1	290	BusChild *kid;
06114d72 PB	291	int target;
	292
	293	/* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE". */
	294	req->resp.tmf->response = VIRTIO_SCSI_S_OK;
	295
	296	switch (req->req.tmf->subtype) {
	297	case VIRTIO_SCSI_T_TMF_ABORT_TASK:
	298	case VIRTIO_SCSI_T_TMF_QUERY_TASK:
	299	if (!d) {
	300	goto fail;
	301	}
	302	if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
	303	goto incorrect_lun;
	304	}
	305	QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
	306	if (r->tag == req->req.tmf->tag) {
	307	break;
	308	}
	309	}
	310	if (r && r->hba_private) {
	311	if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
	312	/* "If the specified command is present in the task set, then
	313	* return a service response set to FUNCTION SUCCEEDED".
	314	*/
	315	req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
	316	} else {
	317	scsi_req_cancel(r);
	318	}
	319	}
	320	break;
	321
	322	case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
	323	if (!d) {
	324	goto fail;
	325	}
	326	if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
	327	goto incorrect_lun;
	328	}
	329	s->resetting++;
	330	qdev_reset_all(&d->qdev);
	331	s->resetting--;
	332	break;
	333
	334	case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
	335	case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
	336	case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
	337	if (!d) {
	338	goto fail;
	339	}
	340	if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
	341	goto incorrect_lun;
	342	}
	343	QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
	344	if (r->hba_private) {
	345	if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
	346	/* "If there is any command present in the task set, then
	347	* return a service response set to FUNCTION SUCCEEDED".
	348	*/
	349	req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
	350	break;
	351	} else {
	352	scsi_req_cancel(r);
	353	}
	354	}
355	}
356	break;
357
358	case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
359	target = req->req.tmf->lun[1];
360	s->resetting++;
0866aca1 AL	361	QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
0866aca1 AL	362	d = DO_UPCAST(SCSIDevice, qdev, kid->child);
06114d72 PB	363	if (d->channel == 0 && d->id == target) {
	364	qdev_reset_all(&d->qdev);
	365	}
	366	}
	367	s->resetting--;
	368	break;
	369
	370	case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
	371	default:
	372	req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
	373	break;
326799c0 SH	374	}
326799c0 SH	375
06114d72 PB	376	return;
	377
	378	incorrect_lun:
	379	req->resp.tmf->response = VIRTIO_SCSI_S_INCORRECT_LUN;
	380	return;
	381
	382	fail:
	383	req->resp.tmf->response = VIRTIO_SCSI_S_BAD_TARGET;
326799c0 SH	384	}
326799c0 SH	385
973abc7f SH	386	static void virtio_scsi_handle_ctrl(VirtIODevice vdev, VirtQueue vq)
973abc7f SH	387	{
326799c0 SH	388	VirtIOSCSI s = (VirtIOSCSI )vdev;
	389	VirtIOSCSIReq *req;
	390
	391	while ((req = virtio_scsi_pop_req(s, vq))) {
06114d72 PB	392	int out_size, in_size;
	393	if (req->elem.out_num < 1 \|\| req->elem.in_num < 1) {
	394	virtio_scsi_bad_req();
	395	continue;
	396	}
	397
	398	out_size = req->elem.out_sg[0].iov_len;
	399	in_size = req->elem.in_sg[0].iov_len;
	400	if (req->req.tmf->type == VIRTIO_SCSI_T_TMF) {
	401	if (out_size < sizeof(VirtIOSCSICtrlTMFReq) \|\|
	402	in_size < sizeof(VirtIOSCSICtrlTMFResp)) {
	403	virtio_scsi_bad_req();
	404	}
	405	virtio_scsi_do_tmf(s, req);
	406
	407	} else if (req->req.tmf->type == VIRTIO_SCSI_T_AN_QUERY \|\|
	408	req->req.tmf->type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
	409	if (out_size < sizeof(VirtIOSCSICtrlANReq) \|\|
	410	in_size < sizeof(VirtIOSCSICtrlANResp)) {
	411	virtio_scsi_bad_req();
	412	}
	413	req->resp.an->event_actual = 0;
	414	req->resp.an->response = VIRTIO_SCSI_S_OK;
	415	}
	416	virtio_scsi_complete_req(req);
326799c0 SH	417	}
	418	}
	419
2ccdcd8d PB	420	static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
	421	size_t resid)
	422	{
	423	VirtIOSCSIReq *req = r->hba_private;
	424
	425	req->resp.cmd->response = VIRTIO_SCSI_S_OK;
	426	req->resp.cmd->status = status;
	427	if (req->resp.cmd->status == GOOD) {
	428	req->resp.cmd->resid = resid;
	429	} else {
	430	req->resp.cmd->resid = 0;
	431	req->resp.cmd->sense_len =
	432	scsi_req_get_sense(r, req->resp.cmd->sense, VIRTIO_SCSI_SENSE_SIZE);
	433	}
	434	virtio_scsi_complete_req(req);
	435	}
	436
	437	static QEMUSGList virtio_scsi_get_sg_list(SCSIRequest r)
	438	{
	439	VirtIOSCSIReq *req = r->hba_private;
	440
	441	return &req->qsgl;
	442	}
	443
	444	static void virtio_scsi_request_cancelled(SCSIRequest *r)
	445	{
	446	VirtIOSCSIReq *req = r->hba_private;
	447
	448	if (!req) {
	449	return;
	450	}
06114d72 PB	451	if (req->dev->resetting) {
	452	req->resp.cmd->response = VIRTIO_SCSI_S_RESET;
	453	} else {
	454	req->resp.cmd->response = VIRTIO_SCSI_S_ABORTED;
	455	}
2ccdcd8d PB	456	virtio_scsi_complete_req(req);
	457	}
	458
	459	static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
326799c0 SH	460	{
	461	req->resp.cmd->response = VIRTIO_SCSI_S_FAILURE;
	462	virtio_scsi_complete_req(req);
973abc7f SH	463	}
	464
	465	static void virtio_scsi_handle_cmd(VirtIODevice vdev, VirtQueue vq)
	466	{
326799c0 SH	467	VirtIOSCSI s = (VirtIOSCSI )vdev;
326799c0 SH	468	VirtIOSCSIReq *req;
2ccdcd8d	469	int n;
326799c0 SH	470
326799c0 SH	471	while ((req = virtio_scsi_pop_req(s, vq))) {
2ccdcd8d	472	SCSIDevice *d;
326799c0 SH	473	int out_size, in_size;
	474	if (req->elem.out_num < 1 \|\| req->elem.in_num < 1) {
	475	virtio_scsi_bad_req();
	476	}
	477
	478	out_size = req->elem.out_sg[0].iov_len;
	479	in_size = req->elem.in_sg[0].iov_len;
	480	if (out_size < sizeof(VirtIOSCSICmdReq) + s->cdb_size \|\|
	481	in_size < sizeof(VirtIOSCSICmdResp) + s->sense_size) {
	482	virtio_scsi_bad_req();
	483	}
	484
	485	if (req->elem.out_num > 1 && req->elem.in_num > 1) {
2ccdcd8d	486	virtio_scsi_fail_cmd_req(req);
326799c0 SH	487	continue;
	488	}
	489
2ccdcd8d PB	490	d = virtio_scsi_device_find(s, req->req.cmd->lun);
	491	if (!d) {
	492	req->resp.cmd->response = VIRTIO_SCSI_S_BAD_TARGET;
	493	virtio_scsi_complete_req(req);
	494	continue;
	495	}
	496	req->sreq = scsi_req_new(d, req->req.cmd->tag,
	497	virtio_scsi_get_lun(req->req.cmd->lun),
	498	req->req.cmd->cdb, req);
	499
	500	if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
	501	int req_mode =
	502	(req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
	503
	504	if (req->sreq->cmd.mode != req_mode \|\|
	505	req->sreq->cmd.xfer > req->qsgl.size) {
	506	req->resp.cmd->response = VIRTIO_SCSI_S_OVERRUN;
	507	virtio_scsi_complete_req(req);
	508	continue;
	509	}
	510	}
	511
	512	n = scsi_req_enqueue(req->sreq);
	513	if (n) {
	514	scsi_req_continue(req->sreq);
	515	}
326799c0	516	}
973abc7f SH	517	}
	518
	519	static void virtio_scsi_get_config(VirtIODevice *vdev,
	520	uint8_t *config)
	521	{
	522	VirtIOSCSIConfig scsiconf = (VirtIOSCSIConfig )config;
	523	VirtIOSCSI s = (VirtIOSCSI )vdev;
	524
	525	stl_raw(&scsiconf->num_queues, s->conf->num_queues);
	526	stl_raw(&scsiconf->seg_max, 128 - 2);
	527	stl_raw(&scsiconf->max_sectors, s->conf->max_sectors);
	528	stl_raw(&scsiconf->cmd_per_lun, s->conf->cmd_per_lun);
	529	stl_raw(&scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
	530	stl_raw(&scsiconf->sense_size, s->sense_size);
	531	stl_raw(&scsiconf->cdb_size, s->cdb_size);
	532	stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
	533	stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
	534	stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
	535	}
	536
	537	static void virtio_scsi_set_config(VirtIODevice *vdev,
	538	const uint8_t *config)
	539	{
	540	VirtIOSCSIConfig scsiconf = (VirtIOSCSIConfig )config;
	541	VirtIOSCSI s = (VirtIOSCSI )vdev;
	542
	543	if ((uint32_t) ldl_raw(&scsiconf->sense_size) >= 65536 \|\|
	544	(uint32_t) ldl_raw(&scsiconf->cdb_size) >= 256) {
	545	error_report("bad data written to virtio-scsi configuration space");
	546	exit(1);
	547	}
	548
	549	s->sense_size = ldl_raw(&scsiconf->sense_size);
	550	s->cdb_size = ldl_raw(&scsiconf->cdb_size);
	551	}
	552
	553	static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
	554	uint32_t requested_features)
	555	{
b6866fee	556	requested_features \|= (1UL << VIRTIO_SCSI_F_HOTPLUG);
973abc7f SH	557	return requested_features;
	558	}
	559
	560	static void virtio_scsi_reset(VirtIODevice *vdev)
	561	{
	562	VirtIOSCSI s = (VirtIOSCSI )vdev;
	563
	564	s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
	565	s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
2baa1beb	566	s->events_dropped = false;
973abc7f SH	567	}
973abc7f SH	568
5db1764c PB	569	/* The device does not have anything to save beyond the virtio data.
	570	* Request data is saved with callbacks from SCSI devices.
	571	*/
	572	static void virtio_scsi_save(QEMUFile f, void opaque)
	573	{
	574	VirtIOSCSI *s = opaque;
	575	virtio_save(&s->vdev, f);
	576	}
	577
	578	static int virtio_scsi_load(QEMUFile f, void opaque, int version_id)
	579	{
	580	VirtIOSCSI *s = opaque;
2a633c46 OW	581	int ret;
	582
	583	ret = virtio_load(&s->vdev, f);
	584	if (ret) {
	585	return ret;
	586	}
5db1764c PB	587	return 0;
	588	}
	589
b6866fee CM	590	static void virtio_scsi_push_event(VirtIOSCSI s, SCSIDevice dev,
	591	uint32_t event, uint32_t reason)
	592	{
	593	VirtIOSCSIReq *req = virtio_scsi_pop_req(s, s->event_vq);
	594	VirtIOSCSIEvent *evt;
64f64855	595	int in_size;
b6866fee	596
64f64855 PB	597	if (!req) {
	598	s->events_dropped = true;
	599	return;
	600	}
b6866fee	601
64f64855 PB	602	if (req->elem.out_num \|\| req->elem.in_num != 1) {
	603	virtio_scsi_bad_req();
	604	}
b6866fee	605
64f64855 PB	606	if (s->events_dropped) {
	607	event \|= VIRTIO_SCSI_T_EVENTS_MISSED;
	608	s->events_dropped = false;
	609	}
	610
	611	in_size = req->elem.in_sg[0].iov_len;
	612	if (in_size < sizeof(VirtIOSCSIEvent)) {
	613	virtio_scsi_bad_req();
	614	}
	615
	616	evt = req->resp.event;
	617	memset(evt, 0, sizeof(VirtIOSCSIEvent));
	618	evt->event = event;
	619	evt->reason = reason;
	620	if (!dev) {
	621	assert(event == VIRTIO_SCSI_T_NO_EVENT);
	622	} else {
b6866fee CM	623	evt->lun[0] = 1;
	624	evt->lun[1] = dev->id;
	625
	626	/* Linux wants us to keep the same encoding we use for REPORT LUNS. */
	627	if (dev->lun >= 256) {
	628	evt->lun[2] = (dev->lun >> 8) \| 0x40;
	629	}
	630	evt->lun[3] = dev->lun & 0xFF;
64f64855 PB	631	}
	632	virtio_scsi_complete_req(req);
	633	}
	634
	635	static void virtio_scsi_handle_event(VirtIODevice vdev, VirtQueue vq)
	636	{
	637	VirtIOSCSI s = (VirtIOSCSI )vdev;
	638
	639	if (s->events_dropped) {
	640	virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
b6866fee CM	641	}
	642	}
	643
	644	static void virtio_scsi_hotplug(SCSIBus bus, SCSIDevice dev)
	645	{
	646	VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
	647
	648	if (((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) &&
	649	(s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
	650	virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
	651	VIRTIO_SCSI_EVT_RESET_RESCAN);
	652	}
	653	}
	654
	655	static void virtio_scsi_hot_unplug(SCSIBus bus, SCSIDevice dev)
	656	{
	657	VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
	658
	659	if ((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
	660	virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
	661	VIRTIO_SCSI_EVT_RESET_REMOVED);
	662	}
	663	}
	664
2ccdcd8d PB	665	static struct SCSIBusInfo virtio_scsi_scsi_info = {
	666	.tcq = true,
	667	.max_channel = VIRTIO_SCSI_MAX_CHANNEL,
	668	.max_target = VIRTIO_SCSI_MAX_TARGET,
	669	.max_lun = VIRTIO_SCSI_MAX_LUN,
	670
	671	.complete = virtio_scsi_command_complete,
	672	.cancel = virtio_scsi_request_cancelled,
b6866fee CM	673	.hotplug = virtio_scsi_hotplug,
b6866fee CM	674	.hot_unplug = virtio_scsi_hot_unplug,
2ccdcd8d	675	.get_sg_list = virtio_scsi_get_sg_list,
5db1764c PB	676	.save_request = virtio_scsi_save_request,
5db1764c PB	677	.load_request = virtio_scsi_load_request,
2ccdcd8d PB	678	};
2ccdcd8d PB	679
973abc7f SH	680	VirtIODevice virtio_scsi_init(DeviceState dev, VirtIOSCSIConf *proxyconf)
	681	{
	682	VirtIOSCSI *s;
5db1764c	683	static int virtio_scsi_id;
d2ad7dd4 PB	684	size_t sz;
d2ad7dd4 PB	685	int i;
973abc7f	686
d2ad7dd4	687	sz = sizeof(VirtIOSCSI) + proxyconf->num_queues * sizeof(VirtQueue *);
973abc7f	688	s = (VirtIOSCSI *)virtio_common_init("virtio-scsi", VIRTIO_ID_SCSI,
d2ad7dd4	689	sizeof(VirtIOSCSIConfig), sz);
973abc7f SH	690
	691	s->qdev = dev;
	692	s->conf = proxyconf;
	693
	694	/* TODO set up vdev function pointers */
	695	s->vdev.get_config = virtio_scsi_get_config;
	696	s->vdev.set_config = virtio_scsi_set_config;
	697	s->vdev.get_features = virtio_scsi_get_features;
	698	s->vdev.reset = virtio_scsi_reset;
	699
	700	s->ctrl_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
	701	virtio_scsi_handle_ctrl);
	702	s->event_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
619d7ae9	703	virtio_scsi_handle_event);
d2ad7dd4 PB	704	for (i = 0; i < s->conf->num_queues; i++) {
	705	s->cmd_vqs[i] = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
	706	virtio_scsi_handle_cmd);
	707	}
973abc7f	708
2ccdcd8d PB	709	scsi_bus_new(&s->bus, dev, &virtio_scsi_scsi_info);
	710	if (!dev->hotplugged) {
	711	scsi_bus_legacy_handle_cmdline(&s->bus);
	712	}
	713
5db1764c PB	714	register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
5db1764c PB	715	virtio_scsi_save, virtio_scsi_load, s);
973abc7f SH	716
	717	return &s->vdev;
	718	}
	719
	720	void virtio_scsi_exit(VirtIODevice *vdev)
	721	{
eb2fa764 PB	722	VirtIOSCSI s = (VirtIOSCSI )vdev;
eb2fa764 PB	723	unregister_savevm(s->qdev, "virtio-scsi", s);
973abc7f SH	724	virtio_cleanup(vdev);
973abc7f SH	725	}