lkml.org 
[lkml]   [2021]   [Nov]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH net] virtio-net: enable big mode correctly
Date
When VIRTIO_NET_F_MTU feature is not negotiated, we assume a very
large max_mtu. In this case, using small packet mode is not correct
since it may breaks the networking when MTU is grater than
ETH_DATA_LEN.

To have a quick fix, simply enable the big packet mode when
VIRTIO_NET_F_MTU is not negotiated. We can do optimization on top.

Reported-by: Eli Cohen <elic@nvidia.com>
Cc: Eli Cohen <elic@nvidia.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7c43bfc1ce44..83ae3ef5eb11 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3200,11 +3200,12 @@ static int virtnet_probe(struct virtio_device *vdev)
dev->mtu = mtu;
dev->max_mtu = mtu;

- /* TODO: size buffers correctly in this case. */
- if (dev->mtu > ETH_DATA_LEN)
- vi->big_packets = true;
}

+ /* TODO: size buffers correctly in this case. */
+ if (dev->max_mtu > ETH_DATA_LEN)
+ vi->big_packets = true;
+
if (vi->any_header_sg)
dev->needed_headroom = vi->hdr_len;

--
2.25.1
\
 
 \ /
  Last update: 2021-11-25 07:08    [W:0.055 / U:1.000 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site