Re: [PATCH net] net: extend virtio_net_hdr csum_start checks to VLAN, IPv6 and IP options

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Oct 08, 2026 at 05:06:30PM -0400, Willem de Bruijn wrote:
> On Thu, Oct 8, 2026 at 4:55 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > On Thu, Oct 08, 2026 at 04:04:16PM -0400, Willem de Bruijn wrote:
> > > netdev-bot+sashiko@ wrote:
> > > > Thank you for your contribution! Sashiko AI review found 3 potential
> > > > issue(s) to consider.
> > > >
> > > > Critical: 0 · High: 2 · Medium: 1 · Low: 0 (1)
> > > >
> > > > If you believe none of the issues are legitimate, please reply to each
> > > > issue of Medium severity or higher and explain why the AI is wrong.
> > > > If any of them are legitimate and you plan to respin, please let patchwork
> > > > know by including "pw-bot: cr" as a separate line at the end of your reply
> > > > (one such reply per series is enough).
> > > >
> > > > - [High] The fix leaves the UDP-tunnel path, virtio_net_hdr_tnl_to_skb()
> > > >   in include/linux/virtio_net.h, with the same weakness it removes from…
> > > > - [High] virtio_net_hdr_thoff_valid() decides whether skb->data starts
> > > >   with an Ethernet header only from `skb->dev->type == ARPHRD_ETHER`…
> > > > - [Medium] On the non-ARPHRD_ETHER branch, virtio_net_hdr_thoff_valid()
> > > >   leaves proto = 0 and then guesses the L3 protocol from the version…
> > >
> > > All comments look valid and require a respin. Any revision will take
> > > them into account.
> > >
> > > Based also on the previous conversation in this thread, will review the
> > > approach. Updated in patchwork to changes requested.
> >
> >
> > But let's agree who works on this, please. Have a bunch of stuff on my
> > plate so if it is you, I'm very happy and will just criticise :)
> 
> Do you agree with my suggested revision that just drops the checksum
> offload request for weird packets?
> 
> Or do you want to investigate your suggestion to skb_checksum_help those here?
> 
> I can't estimate yet how easy/hard that will prove to be. Can
> prototype, but no guarantee that it's a fruitful approach.
> 
> The next few days I'll be OOO, so next week at the earliest.
> 
> We agree that this is not urgent, correct. So can do some prototyping.

Oh I have a prototype. Quite ugly atm.

-- 
MST