When a nic's backend netdev device is changed, the tap device needs to be re-initialized for vnet_hdr and offload features. Also, vhost will have to be re-initialized. This is currently implemented in the virtio set_status callback function.
Signed-off-by: Vasilis Liaskovitis <vasilis.liaskovi...@profitbricks.com> --- hw/virtio-net.c | 30 ++++++++++++++++++++++++++++++ 1 files changed, 30 insertions(+), 0 deletions(-) diff --git a/hw/virtio-net.c b/hw/virtio-net.c index bc5e3a8..858434a 100644 --- a/hw/virtio-net.c +++ b/hw/virtio-net.c @@ -63,6 +63,7 @@ typedef struct VirtIONet } mac_table; uint32_t *vlans; DeviceState *qdev; + VLANClientState *old_peer; } VirtIONet; /* TODO @@ -137,10 +138,38 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status) } } +static int peer_has_vnet_hdr(VirtIONet *n); + static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status) { VirtIONet *n = to_virtio_net(vdev); + uint32_t features; + + /* re-initialize backend netdev if it is has been changed */ + if (n->old_peer != n->nic->nc.peer) { + features = vdev->guest_features; + + if (peer_has_vnet_hdr(n)) + tap_using_vnet_hdr(n->nic->nc.peer, 1); + + if (n->has_vnet_hdr) { + tap_set_offload(n->nic->nc.peer, + (features >> VIRTIO_NET_F_GUEST_CSUM) & 1, + (features >> VIRTIO_NET_F_GUEST_TSO4) & 1, + (features >> VIRTIO_NET_F_GUEST_TSO6) & 1, + (features >> VIRTIO_NET_F_GUEST_ECN) & 1, + (features >> VIRTIO_NET_F_GUEST_UFO) & 1); + } + if ((n->nic->nc.peer->info->type == NET_CLIENT_TYPE_TAP) && + tap_get_vhost_net(n->nic->nc.peer)) { + vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features); + } + /* vhost will have to be restarted */ + if (n->vhost_started) + n->vhost_started = 0; + n->old_peer = n->nic->nc.peer; + } virtio_net_vhost_status(n, status); if (!n->tx_waiting) { @@ -1044,6 +1073,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf, n->vlans = g_malloc0(MAX_VLAN >> 3); n->qdev = dev; + n->old_peer = conf->peer; register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION, virtio_net_save, virtio_net_load, n); -- 1.7.9