Commit 5f800801 authored by Jason Wang's avatar Jason Wang Committed by Anthony Liguori
Browse files

virtio-net: migration support for multiqueue 



This patch add migration support for multiqueue virtio-net. Instead of bumping
the version, we conditionally send the info of multiqueue only when the device
support more than one queue to maintain the backward compatibility.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent fed699f9

hw/virtio-net.c

+29 −6
Original line number Diff line number Diff line
@@ -1094,8 +1094,8 @@ static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue, int ctrl) 


static void virtio_net_save(QEMUFile *f, void *opaque)

{

    int i;

    VirtIONet *n = opaque;

    VirtIONetQueue *q = &n->vqs[0];



    /* At this point, backend must be stopped, otherwise

     * it might keep writing to memory. */
@@ -1103,7 +1103,7 @@ static void virtio_net_save(QEMUFile *f, void *opaque) 
    virtio_save(&n->vdev, f);



    qemu_put_buffer(f, n->mac, ETH_ALEN);

    qemu_put_be32(f, q->tx_waiting);

    qemu_put_be32(f, n->vqs[0].tx_waiting);

    qemu_put_be32(f, n->mergeable_rx_bufs);

    qemu_put_be16(f, n->status);

    qemu_put_byte(f, n->promisc);
@@ -1119,13 +1119,19 @@ static void virtio_net_save(QEMUFile *f, void *opaque) 
    qemu_put_byte(f, n->nouni);

    qemu_put_byte(f, n->nobcast);

    qemu_put_byte(f, n->has_ufo);

    if (n->max_queues > 1) {

        qemu_put_be16(f, n->max_queues);

        qemu_put_be16(f, n->curr_queues);

        for (i = 1; i < n->curr_queues; i++) {

            qemu_put_be32(f, n->vqs[i].tx_waiting);

        }

    }

}



static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)

{

    VirtIONet *n = opaque;

    VirtIONetQueue *q = &n->vqs[0];

    int ret, i;

    int ret, i, link_down;



    if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)

        return -EINVAL;
@@ -1136,7 +1142,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id) 
    }



    qemu_get_buffer(f, n->mac, ETH_ALEN);

    q->tx_waiting = qemu_get_be32(f);

    n->vqs[0].tx_waiting = qemu_get_be32(f);



    virtio_net_set_mrg_rx_bufs(n, qemu_get_be32(f));
@@ -1206,6 +1212,20 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id) 
        }

    }



    if (n->max_queues > 1) {

        if (n->max_queues != qemu_get_be16(f)) {

            error_report("virtio-net: different max_queues ");

            return -1;

        }



        n->curr_queues = qemu_get_be16(f);

        for (i = 1; i < n->curr_queues; i++) {

            n->vqs[i].tx_waiting = qemu_get_be32(f);

        }

    }



    virtio_net_set_queues(n);



    /* Find the first multicast entry in the saved MAC filter */

    for (i = 0; i < n->mac_table.in_use; i++) {

        if (n->mac_table.macs[i * ETH_ALEN] & 1) {
@@ -1216,7 +1236,10 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id) 


    /* nc.link_down can't be migrated, so infer link_down according

     * to link status bit in n->status */

    qemu_get_queue(n->nic)->link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;

    link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;

    for (i = 0; i < n->max_queues; i++) {

        qemu_get_subqueue(n->nic, i)->link_down = link_down;

    }



    return 0;

}