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

[Jason Wang]

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:
> > 在 2021/8/12 上午6:17, Jakub Kicinski 写道:
> > > On Wed, 11 Aug 2021 16:16:23 +0800 Jason Wang wrote:
> > > > 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.
> >
> >
> > > > 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


>