From b89587a7af4b2a2e0682c304224be4041e993548 Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Tue, 17 Dec 2013 11:44:35 +0000 Subject: [PATCH] xen-netback: add gso_segs calculation netback already has code which parses IPv4 and v6 headers to set up checksum offsets and these are always applied to GSO packets being sent from frontends. It's therefore suboptimal that GSOs are being marked SKB_GSO_DODGY to defer the gso_segs calculation when netback already has all necessary information to hand to do the calculation. This patch adds that calculation. Signed-off-by: Paul Durrant Cc: Wei Liu Cc: Ian Campbell Cc: David Vrabel Cc: Eric Dumazet Acked-by: Eric Dumazet Acked-by: Wei Liu Signed-off-by: David S. Miller --- drivers/net/xen-netback/netback.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 773b731e3e52..611aebee4583 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1043,10 +1043,7 @@ static int xenvif_set_skb_gso(struct xenvif *vif, } skb_shinfo(skb)->gso_size = gso->u.gso.size; - - /* Header must be checked, and gso_segs computed. */ - skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; - skb_shinfo(skb)->gso_segs = 0; + /* gso_segs will be calculated later */ return 0; } @@ -1581,6 +1578,20 @@ static int xenvif_tx_submit(struct xenvif *vif) skb_probe_transport_header(skb, 0); + /* If the packet is GSO then we will have just set up the + * transport header offset in checksum_setup so it's now + * straightforward to calculate gso_segs. + */ + if (skb_is_gso(skb)) { + int mss = skb_shinfo(skb)->gso_size; + int hdrlen = skb_transport_header(skb) - + skb_mac_header(skb) + + tcp_hdrlen(skb); + + skb_shinfo(skb)->gso_segs = + DIV_ROUND_UP(skb->len - hdrlen, mss); + } + vif->dev->stats.rx_bytes += skb->len; vif->dev->stats.rx_packets++; -- 2.20.1