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: Jason Wang <jasowang@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Jason Wang 2013-01-30 19:12:40 +08:00 committed by Anthony Liguori
parent fed699f9ca
commit 5f80080183

View file

@ -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;
}