virtio_net: Add a MAC filter table

Make use of the MAC control virtqueue class to support a MAC
filter table.  The filter table is managed by the hypervisor.
We consider the table to be available if the CTRL_RX feature
bit is set.  We leave it to the hypervisor to manage the table
and enable promiscuous or all-multi mode as necessary depending
on the resources available to it.

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, 23 insertions, 0 deletions

diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 63b2461a40f1..ba82b653cace 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -88,4 +88,27 @@ typedef __u8 virtio_net_ctrl_ack;
  #define VIRTIO_NET_CTRL_RX_PROMISC      0
  #define VIRTIO_NET_CTRL_RX_ALLMULTI     1
 
+/*
+ * Control the MAC filter table.
+ *
+ * The MAC filter table is managed by the hypervisor, the guest should
+ * assume the size is infinite.  Filtering should be considered
+ * non-perfect, ie. based on hypervisor resources, the guest may
+ * received packets from sources not specified in the filter list.
+ *
+ * In addition to the class/cmd header, the TABLE_SET command requires
+ * two out scatterlists.  Each contains a 4 byte count of entries followed
+ * by a concatenated byte stream of the ETH_ALEN MAC addresses.  The
+ * first sg list contains unicast addresses, the second is for multicast.
+ * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
+ * is available.
+ */
+struct virtio_net_ctrl_mac {
+        __u32 entries;
+        __u8 macs[][ETH_ALEN];
+} __attribute__((packed));
+
+#define VIRTIO_NET_CTRL_MAC    1
+ #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
+
 #endif /* _LINUX_VIRTIO_NET_H */