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, 14 insertions, 0 deletions

diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index ba82b653cace..242348bb3766 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -25,6 +25,7 @@
 #define VIRTIO_NET_F_STATUS     16      /* virtio_net_config.status available */
 #define VIRTIO_NET_F_CTRL_VQ    17      /* Control channel available */
 #define VIRTIO_NET_F_CTRL_RX    18      /* Control channel RX mode support */
+#define VIRTIO_NET_F_CTRL_VLAN  19      /* Control channel VLAN filtering */
 
 #define VIRTIO_NET_S_LINK_UP    1       /* Link is up */
 
@@ -111,4 +112,17 @@ struct virtio_net_ctrl_mac {
 #define VIRTIO_NET_CTRL_MAC    1
  #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
 
+/*
+ * Control VLAN filtering
+ *
+ * The VLAN filter table is controlled via a simple ADD/DEL interface.
+ * VLAN IDs not added may be filterd by the hypervisor.  Del is the
+ * opposite of add.  Both commands expect an out entry containing a 2
+ * byte VLAN ID.  VLAN filterting is available with the
+ * VIRTIO_NET_F_CTRL_VLAN feature bit.
+ */
+#define VIRTIO_NET_CTRL_VLAN       2
+ #define VIRTIO_NET_CTRL_VLAN_ADD             0
+ #define VIRTIO_NET_CTRL_VLAN_DEL             1
+
 #endif /* _LINUX_VIRTIO_NET_H */