Commit 63c7e542 authored by Fam Zheng's avatar Fam Zheng Committed by Paolo Bonzini
Browse files

virtio-scsi: Hook up with dataplane 



This enables the virtio-scsi-dataplane code by setting the iothread
in virtio-scsi device, and makes any function that is called by
back from dataplane to cooperate with the caller: they need to be
vring/iothread aware when handling the requests and using scsi devices
on the bus.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 91cb1c9b

hw/scsi/virtio-scsi.c

+48 −4
Original line number Diff line number Diff line
@@ -69,13 +69,19 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req) 
    VirtIODevice *vdev = VIRTIO_DEVICE(s);



    qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);

    if (req->vring) {

        assert(req->vq == NULL);

        virtio_scsi_vring_push_notify(req);

    } else {

        virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);

        virtio_notify(vdev, vq);

    }



    if (req->sreq) {

        req->sreq->hba_private = NULL;

        scsi_req_unref(req->sreq);

    }

    virtio_scsi_free_req(req);

    virtio_notify(vdev, vq);

}



static void virtio_scsi_bad_req(void)
@@ -208,6 +214,11 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req) 
    BusChild *kid;

    int target;



    if (s->dataplane_started && bdrv_get_aio_context(d->conf.bs) != s->ctx) {

        aio_context_acquire(s->ctx);

        bdrv_set_aio_context(d->conf.bs, s->ctx);

        aio_context_release(s->ctx);

    }

    /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */

    req->resp.tmf.response = VIRTIO_SCSI_S_OK;
@@ -346,6 +357,10 @@ static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) 
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;

    VirtIOSCSIReq *req;



    if (s->ctx) {

        virtio_scsi_dataplane_start(s);

        return;

    }

    while ((req = virtio_scsi_pop_req(s, vq))) {

        virtio_scsi_handle_ctrl_req(s, req);

    }
@@ -457,6 +472,11 @@ void virtio_scsi_handle_cmd_req(VirtIOSCSI *s, VirtIOSCSIReq *req) 
        virtio_scsi_complete_cmd_req(req);

        return;

    }

    if (s->dataplane_started && bdrv_get_aio_context(d->conf.bs) != s->ctx) {

        aio_context_acquire(s->ctx);

        bdrv_set_aio_context(d->conf.bs, s->ctx);

        aio_context_release(s->ctx);

    }

    req->sreq = scsi_req_new(d, req->req.cmd.tag,

                             virtio_scsi_get_lun(req->req.cmd.lun),

                             req->req.cdb, req);
@@ -481,6 +501,10 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) 
    VirtIOSCSI *s = (VirtIOSCSI *)vdev;

    VirtIOSCSIReq *req;



    if (s->ctx) {

        virtio_scsi_dataplane_start(s);

        return;

    }

    while ((req = virtio_scsi_pop_req(s, vq))) {

        virtio_scsi_handle_cmd_req(s, req);

    }
@@ -531,6 +555,9 @@ static void virtio_scsi_reset(VirtIODevice *vdev) 
    VirtIOSCSI *s = VIRTIO_SCSI(vdev);

    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);



    if (s->ctx) {

        virtio_scsi_dataplane_stop(s);

    }

    s->resetting++;

    qbus_reset_all(&s->bus.qbus);

    s->resetting--;
@@ -573,10 +600,19 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev, 
        return;

    }



    if (s->dataplane_started) {

        assert(s->ctx);

        aio_context_acquire(s->ctx);

    }



    if (s->dataplane_started) {

        req = virtio_scsi_pop_req_vring(s, s->event_vring);

    } else {

        req = virtio_scsi_pop_req(s, vs->event_vq);

    }

    if (!req) {

        s->events_dropped = true;

        return;

        goto out;

    }



    if (s->events_dropped) {
@@ -605,12 +641,20 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev, 
        evt->lun[3] = dev->lun & 0xFF;

    }

    virtio_scsi_complete_req(req);

out:

    if (s->dataplane_started) {

        aio_context_release(s->ctx);

    }

}



static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)

{

    VirtIOSCSI *s = VIRTIO_SCSI(vdev);



    if (s->ctx) {

        virtio_scsi_dataplane_start(s);

        return;

    }

    if (s->events_dropped) {

        virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);

    }