virtio_net: Add a set_rx_mode interface

Make use of the RX_MODE control virtqueue class to enable the
set_rx_mode netdev interface.  This allows us to selectively
enable/disable promiscuous and allmulti mode so we don't see
packets we don't want.  For now, we automatically enable these
as needed if additional unicast or multicast addresses are
requested.

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>
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 245eda8..63b2461 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -24,6 +24,7 @@
 #define VIRTIO_NET_F_MRG_RXBUF	15	/* Host can merge receive buffers. */
 #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_S_LINK_UP	1	/* Link is up */
 
@@ -77,4 +78,14 @@
 #define VIRTIO_NET_OK     0
 #define VIRTIO_NET_ERR    1
 
+/*
+ * Control the RX mode, ie. promisucous and allmulti.  PROMISC and
+ * ALLMULTI commands require an "out" sg entry containing a 1 byte
+ * state value, zero = disable, non-zero = enable.  These commands
+ * are supported with the VIRTIO_NET_F_CTRL_RX feature.
+ */
+#define VIRTIO_NET_CTRL_RX    0
+ #define VIRTIO_NET_CTRL_RX_PROMISC      0
+ #define VIRTIO_NET_CTRL_RX_ALLMULTI     1
+
 #endif /* _LINUX_VIRTIO_NET_H */