Re: [RFC PATCH] virtio-net: use NETIF_F_GRO_HW instead of NETIF_F_LRO

在 2021/8/12 下午12:50, Michael S. Tsirkin 写道:

On Thu, Aug 12, 2021 at 11:23:04AM +0800, Jason Wang wrote:

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在 2021/8/12 上午6:17, Jakub Kicinski 写道:

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On Wed, 11 Aug 2021 16:16:23 +0800 Jason Wang wrote:

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Try to fix this by using NETIF_F_GRO_HW instead so we're not
guaranteed to be re-segmented as original.

This sentence may need rephrasing.

Right, actually, I meant:


Try to fix this by using NETIF_F_GRO_HW instead. But we're not sure the
packet could be re-segmented to the exact original packet stream. Since it's
really depends on the bakcend implementation.

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Or we may want a new netdev
feature like RX_GSO since the guest offloads for virtio-net is
actually to receive GSO packet.

Or we can try not advertise LRO is control guest offloads is not
enabled. This solves the warning but will still slow down the traffic.

IMO gro-hw fits pretty well, patch looks good.

If the re-segmentation is not a issue. I will post a formal patch.

Thanks

It is but the point is even though spec did not require this
we always allowed these configurations
in the past so hopefully most of them are not broken and combine
packets in the same way as GRO. Let's not break them all
in an attempt to catch bad configs, and meanwhile amend
the spec to recommend doing GW GRO.

Ok, let me add this in the commit log and send a formal patch.

Thanks