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>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 3492ae0..73f01db 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -24,6 +24,10 @@
#include <linux/virtio_net.h>
#include <linux/scatterlist.h>
+static int csum = 1, gso = 1;
+module_param(csum, bool, 0444);
+module_param(gso, bool, 0444);
+
/* FIXME: MTU in config. */
#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
@@ -88,13 +92,10 @@
if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
pr_debug("GSO!\n");
- switch (hdr->gso_type) {
+ switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
break;
- case VIRTIO_NET_HDR_GSO_TCPV4_ECN:
- skb_shinfo(skb)->gso_type = SKB_GSO_TCP_ECN;
- break;
case VIRTIO_NET_HDR_GSO_UDP:
skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
break;
@@ -108,6 +109,9 @@
goto frame_err;
}
+ if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
+ skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
+
skb_shinfo(skb)->gso_size = hdr->gso_size;
if (skb_shinfo(skb)->gso_size == 0) {
if (net_ratelimit())
@@ -244,9 +248,7 @@
if (skb_is_gso(skb)) {
hdr->hdr_len = skb_transport_header(skb) - skb->data;
hdr->gso_size = skb_shinfo(skb)->gso_size;
- if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
- hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4_ECN;
- else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
@@ -254,6 +256,8 @@
hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
else
BUG();
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
+ hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
} else {
hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
hdr->gso_size = hdr->hdr_len = 0;
@@ -330,17 +334,13 @@
SET_NETDEV_DEV(dev, &vdev->dev);
/* Do we support "hardware" checksums? */
- if (vdev->config->feature(vdev, VIRTIO_NET_F_NO_CSUM)) {
+ if (csum && vdev->config->feature(vdev, VIRTIO_NET_F_CSUM)) {
/* This opens up the world of extra features. */
dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
- if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO4))
- dev->features |= NETIF_F_TSO;
- if (vdev->config->feature(vdev, VIRTIO_NET_F_UFO))
- dev->features |= NETIF_F_UFO;
- if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO4_ECN))
- dev->features |= NETIF_F_TSO_ECN;
- if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO6))
- dev->features |= NETIF_F_TSO6;
+ if (gso && vdev->config->feature(vdev, VIRTIO_NET_F_GSO)) {
+ dev->features |= NETIF_F_TSO | NETIF_F_UFO
+ | NETIF_F_TSO_ECN | NETIF_F_TSO6;
+ }
}
/* Configuration may specify what MAC to use. Otherwise random. */
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 1456f7b..1ea3351 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 @@
__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 */