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@xxxxxxxxxxxxxxx>
---
drivers/net/virtio_net.c | 32 ++++++++++++++++----------------
include/linux/virtio_net.h | 12 ++++--------
2 files changed, 20 insertions(+), 24 deletions(-)
diff -r 4fb788b18cf8 drivers/net/virtio_net.c
--- a/drivers/net/virtio_net.c Wed Jan 23 13:07:59 2008 +1100
+++ b/drivers/net/virtio_net.c Wed Jan 23 18:46:05 2008 +1100
@@ -26,6 +26,10 @@
static int napi_weight = 128;
module_param(napi_weight, int, 0444);
+
+static int csum = 1, gso = 1;
+module_param(csum, int, 0444);
+module_param(gso, int, 0444);
MODULE_LICENSE("GPL");
@@ -95,12 +99,9 @@ static void receive_skb(struct net_devic
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;
@@ -114,6 +115,9 @@ static void receive_skb(struct net_devic
dev->name, hdr->gso_type);
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) {
@@ -249,9 +253,7 @@ static int start_xmit(struct sk_buff *sk
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;
@@ -259,6 +261,8 @@ static int start_xmit(struct sk_buff *sk
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;
@@ -354,17 +358,13 @@ static int virtnet_probe(struct virtio_d
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 -r 4fb788b18cf8 include/linux/virtio_net.h
--- a/include/linux/virtio_net.h Wed Jan 23 13:07:59 2008 +1100
+++ b/include/linux/virtio_net.h Wed Jan 23 18:46:05 2008 +1100
@@ -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 */
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