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From: "Michael S. Tsirkin" <mst@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: [PATCH] virtio_net: enable big packets for large MTU values
Date: Wed, 29 Mar 2017 15:38:09 +0300	[thread overview]
Message-ID: <1490791079-22108-1-git-send-email-mst@redhat.com> (raw)

If one enables e.g. jumbo frames without mergeable
buffers, packets won't fit in 1500 byte buffers
we use. Switch to big packet mode instead.
TODO: make sizing more exact, possibly extend small
packet mode to use larger pages.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/virtio_net.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index e0fb3707..9dc31dc 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2428,6 +2428,10 @@ 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;
 	}
 
 	if (vi->any_header_sg)
-- 
MST

             reply	other threads:[~2017-03-29 12:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-29 12:38 Michael S. Tsirkin [this message]
2017-03-29 16:13 ` [PATCH] virtio_net: enable big packets for large MTU values Michael S. Tsirkin
2017-03-30  4:03 ` Jason Wang

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