The branch main has been updated by tuexen:
URL: https://cgit.FreeBSD.org/src/commit/?id=d4697a6b56168876fc0ffec1a0bb1b24d25b198e
commit d4697a6b56168876fc0ffec1a0bb1b24d25b198e
Author: Michael Tuexen <tuexen at FreeBSD.org>
AuthorDate: 2021-03-18 20:25:47 +0000
Commit: Michael Tuexen <tuexen at FreeBSD.org>
CommitDate: 2021-03-18 20:32:20 +0000
vtnet: fix TSO for TCP/IPv6
The decision whether a TCP packet is sent over IPv4 or IPv6 was
based on ethertype, which works correctly. In D27926 the criteria
was changed to checking if the CSUM_IP_TSO flag is set in the
csum-flags and then considering it to be TCP/IPv4.
However, the TCP stack sets the flag to CSUM_TSO for IPv4 and IPv6,
where CSUM_TSO is defined as CSUM_IP_TSO|CSUM_IP6_TSO.
Therefore TCP/IPv6 packets gets mis-classified as TCP/IPv4,
which breaks TSO for TCP/IPv6.
This patch bases the check again on the ethertype.
This fix will be MFC instantly as discussed with re(gjb).
MFC after: instantly
PR: 254366
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D29331
---
sys/dev/virtio/network/if_vtnet.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/sys/dev/virtio/network/if_vtnet.c b/sys/dev/virtio/network/if_vtnet.c
index 09110183c30f..3650d19fbe0e 100644
--- a/sys/dev/virtio/network/if_vtnet.c
+++ b/sys/dev/virtio/network/if_vtnet.c
@@ -2389,7 +2389,7 @@ vtnet_txq_offload_ctx(struct vtnet_txq *txq, struct mbuf *m, int *etype,
}
static int
-vtnet_txq_offload_tso(struct vtnet_txq *txq, struct mbuf *m, int flags,
+vtnet_txq_offload_tso(struct vtnet_txq *txq, struct mbuf *m, int eth_type,
int offset, struct virtio_net_hdr *hdr)
{
static struct timeval lastecn;
@@ -2407,8 +2407,8 @@ vtnet_txq_offload_tso(struct vtnet_txq *txq, struct mbuf *m, int flags,
hdr->hdr_len = vtnet_gtoh16(sc, offset + (tcp->th_off << 2));
hdr->gso_size = vtnet_gtoh16(sc, m->m_pkthdr.tso_segsz);
- hdr->gso_type = (flags & CSUM_IP_TSO) ?
- VIRTIO_NET_HDR_GSO_TCPV4 : VIRTIO_NET_HDR_GSO_TCPV6;
+ hdr->gso_type = eth_type == ETHERTYPE_IP ? VIRTIO_NET_HDR_GSO_TCPV4 :
+ VIRTIO_NET_HDR_GSO_TCPV6;
if (__predict_false(tcp->th_flags & TH_CWR)) {
/*
@@ -2474,7 +2474,7 @@ vtnet_txq_offload(struct vtnet_txq *txq, struct mbuf *m,
goto drop;
}
- error = vtnet_txq_offload_tso(txq, m, flags, csum_start, hdr);
+ error = vtnet_txq_offload_tso(txq, m, etype, csum_start, hdr);
if (error)
goto drop;
}