On Fri, Dec 02, 2016 at 12:49:45PM -0800, John Fastabend wrote:
> This adds support for dynamically setting the LRO feature flag. The
> message to control guest features in the backend uses the
> CTRL_GUEST_OFFLOADS msg type.
>
> Signed-off-by: John Fastabend <john.r.fastab...@intel.com>
> ---
> drivers/net/virtio_net.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index a21d93a..d814e7cb 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1419,6 +1419,41 @@ static void virtnet_init_settings(struct net_device
> *dev)
> .set_settings = virtnet_set_settings,
> };
>
> +static int virtnet_set_features(struct net_device *netdev,
> + netdev_features_t features)
> +{
> + struct virtnet_info *vi = netdev_priv(netdev);
> + struct virtio_device *vdev = vi->vdev;
> + struct scatterlist sg;
> + u64 offloads = 0;
> +
> + if (features & NETIF_F_LRO)
> + offloads |= (1 << VIRTIO_NET_F_GUEST_TSO4) |
> + (1 << VIRTIO_NET_F_GUEST_TSO6);
> +
> + if (features & NETIF_F_RXCSUM)
> + offloads |= (1 << VIRTIO_NET_F_GUEST_CSUM);
> +
> + if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
> + sg_init_one(&sg, &offloads, sizeof(uint64_t));
> + if (!virtnet_send_command(vi,
> + VIRTIO_NET_CTRL_GUEST_OFFLOADS,
> + VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET,
> + &sg)) {
> + dev_warn(&netdev->dev,
> + "Failed to set guest offloads by virtnet
> command.\n");
> + return -EINVAL;
> + }
> + } else if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) &&
> + !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
No need for VIRTIO_F_VERSION_1 here.
> + dev_warn(&netdev->dev,
> + "No support for setting offloads pre version_1.\n");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static const struct net_device_ops virtnet_netdev = {
> .ndo_open = virtnet_open,
> .ndo_stop = virtnet_close,
> @@ -1435,6 +1470,7 @@ static void virtnet_init_settings(struct net_device
> *dev)
> #ifdef CONFIG_NET_RX_BUSY_POLL
> .ndo_busy_poll = virtnet_busy_poll,
> #endif
> + .ndo_set_features = virtnet_set_features,
> };
>
> static void virtnet_config_changed_work(struct work_struct *work)
> @@ -1815,6 +1851,12 @@ static int virtnet_probe(struct virtio_device *vdev)
> if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
> dev->features |= NETIF_F_RXCSUM;
>
> + if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) &&
> + virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)) {
> + dev->features |= NETIF_F_LRO;
> + dev->hw_features |= NETIF_F_LRO;
> + }
> +
> dev->vlan_features = dev->features;
>
> /* MTU range: 68 - 65535 */
> @@ -2057,7 +2099,8 @@ static int virtnet_restore(struct virtio_device *vdev)
> VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
> VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
> VIRTIO_NET_F_CTRL_MAC_ADDR, \
> - VIRTIO_NET_F_MTU
> + VIRTIO_NET_F_MTU, \
> + VIRTIO_NET_F_CTRL_GUEST_OFFLOADS
>
> static unsigned int features[] = {
> VIRTNET_FEATURES,
