virtio_net: Add support for VLAN filtering in the hypervisor

VLAN filtering allows the hypervisor to drop packets from VLANs
that we're not a part of, further reducing the number of extraneous
packets recieved.  This makes use of the VLAN virtqueue command class.
The CTRL_VLAN feature bit tells us whether the backend supports VLAN
filtering.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 30 insertions, 1 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index daab9c9b0a40..e68813a246db 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -727,6 +727,30 @@ static void virtnet_set_rx_mode(struct net_device *dev)
         kfree(buf);
 }
 
+static void virnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
+{
+        struct virtnet_info *vi = netdev_priv(dev);
+        struct scatterlist sg;
+
+        sg_set_buf(&sg, &vid, sizeof(vid));
+
+        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
+                                  VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
+                dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
+}
+
+static void virnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
+{
+        struct virtnet_info *vi = netdev_priv(dev);
+        struct scatterlist sg;
+
+        sg_set_buf(&sg, &vid, sizeof(vid));
+
+        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
+                                  VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
+                dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
+}
+
 static struct ethtool_ops virtnet_ethtool_ops = {
         .set_tx_csum = virtnet_set_tx_csum,
         .set_sg = ethtool_op_set_sg,
@@ -753,6 +777,8 @@ static const struct net_device_ops virtnet_netdev = {
         .ndo_set_mac_address = eth_mac_addr,
         .ndo_set_rx_mode     = virtnet_set_rx_mode,
         .ndo_change_mtu      = virtnet_change_mtu,
+        .ndo_vlan_rx_add_vid = virnet_vlan_rx_add_vid,
+        .ndo_vlan_rx_kill_vid = virnet_vlan_rx_kill_vid,
 #ifdef CONFIG_NET_POLL_CONTROLLER
         .ndo_poll_controller = virtnet_netpoll,
 #endif
@@ -877,6 +903,9 @@ static int virtnet_probe(struct virtio_device *vdev)
                         err = PTR_ERR(vi->svq);
                         goto free_send;
                 }
+
+                if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
+                        dev->features |= NETIF_F_HW_VLAN_FILTER;
         }
 
         /* Initialize our empty receive and send queues. */
@@ -967,7 +996,7 @@ static unsigned int features[] = {
         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
         VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
-        VIRTIO_NET_F_CTRL_RX,
+        VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
         VIRTIO_F_NOTIFY_ON_EMPTY,
 };