virtio: Tweak virtio_net defines

1) Turn GSO on virtio net into an all-or-nothing (keep checksumming
   separate).  Having multiple bits is a pain: if you can't support something
   you should handle it in software, which is still a performance win.

2) Make VIRTIO_NET_HDR_GSO_ECN a flag in the header, so it can apply to
   IPv6 or v4.

3) Rename VIRTIO_NET_F_NO_CSUM to VIRTIO_NET_F_CSUM (ie. means we do
   checksumming).

4) Add csum and gso params to virtio_net to allow more testing.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 4 insertions, 8 deletions

diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 1456f7b936d0..1ea3351df609 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -6,12 +6,9 @@
 #define VIRTIO_ID_NET   1
 
 /* The feature bitmap for virtio net */
-#define VIRTIO_NET_F_NO_CSUM    0
-#define VIRTIO_NET_F_TSO4       1
-#define VIRTIO_NET_F_UFO        2
-#define VIRTIO_NET_F_TSO4_ECN   3
-#define VIRTIO_NET_F_TSO6       4
-#define VIRTIO_NET_F_MAC        5
+#define VIRTIO_NET_F_CSUM       0       /* Can handle pkts w/ partial csum */
+#define VIRTIO_NET_F_MAC        5       /* Host has given MAC address. */
+#define VIRTIO_NET_F_GSO        6       /* Can handle pkts w/ any GSO type */
 
 struct virtio_net_config
 {
@@ -27,10 +24,9 @@ struct virtio_net_hdr
         __u8 flags;
 #define VIRTIO_NET_HDR_GSO_NONE         0       // Not a GSO frame
 #define VIRTIO_NET_HDR_GSO_TCPV4        1       // GSO frame, IPv4 TCP (TSO)
-/* FIXME: Do we need this?  If they said they can handle ECN, do they care? */
-#define VIRTIO_NET_HDR_GSO_TCPV4_ECN    2       // GSO frame, IPv4 TCP w/ ECN
 #define VIRTIO_NET_HDR_GSO_UDP          3       // GSO frame, IPv4 UDP (UFO)
 #define VIRTIO_NET_HDR_GSO_TCPV6        4       // GSO frame, IPv6 TCP
+#define VIRTIO_NET_HDR_GSO_ECN          0x80    // TCP has ECN set
         __u8 gso_type;
         __u16 hdr_len;          /* Ethernet + IP + tcp/udp hdrs */
         __u16 gso_size;         /* Bytes to append to gso_hdr_len per frame */