Commit 47b70fb1 authored by Stefano Stabellini's avatar Stefano Stabellini
Browse files

xen/9pfs: receive requests from the frontend 



Upon receiving an event channel notification from the frontend, schedule
the bottom half. From the bottom half, read one request from the ring,
create a pdu and call pdu_submit to handle it.

For now, only handle one request per ring at a time.

Signed-off-by: default avatarStefano Stabellini <stefano@aporeto.com>
CC: anthony.perard@citrix.com
CC: jgross@suse.com
CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
CC: Greg Kurz <groug@kaod.org>
parent f23ef34a

hw/9pfs/xen-9p-backend.c

+50 −0
Original line number Diff line number Diff line
@@ -100,12 +100,62 @@ static int xen_9pfs_init(struct XenDevice *xendev) 
    return 0;

}



static int xen_9pfs_receive(Xen9pfsRing *ring)

{

    P9MsgHeader h;

    RING_IDX cons, prod, masked_prod, masked_cons;

    V9fsPDU *pdu;



    if (ring->inprogress) {

        return 0;

    }



    cons = ring->intf->out_cons;

    prod = ring->intf->out_prod;

    xen_rmb();



    if (xen_9pfs_queued(prod, cons, XEN_FLEX_RING_SIZE(ring->ring_order)) <

        sizeof(h)) {

        return 0;

    }

    ring->inprogress = true;



    masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));

    masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));



    xen_9pfs_read_packet((uint8_t *) &h, ring->ring.out, sizeof(h),

                         masked_prod, &masked_cons,

                         XEN_FLEX_RING_SIZE(ring->ring_order));



    /* cannot fail, because we only handle one request per ring at a time */

    pdu = pdu_alloc(&ring->priv->state);

    pdu->size = le32_to_cpu(h.size_le);

    pdu->id = h.id;

    pdu->tag = le32_to_cpu(h.tag_le);

    ring->out_size = le32_to_cpu(h.size_le);

    ring->out_cons = cons + le32_to_cpu(h.size_le);



    qemu_co_queue_init(&pdu->complete);

    pdu_submit(pdu);



    return 0;

}



static void xen_9pfs_bh(void *opaque)

{

    Xen9pfsRing *ring = opaque;

    xen_9pfs_receive(ring);

}



static void xen_9pfs_evtchn_event(void *opaque)

{

    Xen9pfsRing *ring = opaque;

    evtchn_port_t port;



    port = xenevtchn_pending(ring->evtchndev);

    xenevtchn_unmask(ring->evtchndev, port);



    qemu_bh_schedule(ring->bh);

}



static int xen_9pfs_free(struct XenDevice *xendev)