Re: [EXT] Re: [PATCH net-next] net: mvpp2: Add parsing support for different IPv4 IHL values

[Marcin Wojtas]

Hi Stefan,

wt., 13 kwi 2021 o 11:56 Stefan Chulski <stefanc@xxxxxxxxxxx> napisał(a):
>
> > > -----Original Message-----
> > > From: Russell King - ARM Linux admin <linux@xxxxxxxxxxxxxxx>
> > > Sent: Tuesday, April 13, 2021 12:18 PM
> > > To: Stefan Chulski <stefanc@xxxxxxxxxxx>
> > > Cc: netdev@xxxxxxxxxxxxxxx; thomas.petazzoni@xxxxxxxxxxx;
> > > davem@xxxxxxxxxxxxx; Nadav Haklai <nadavh@xxxxxxxxxxx>; Yan
> > Markman
> > > <ymarkman@xxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> > kuba@xxxxxxxxxx;
> > > mw@xxxxxxxxxxxx; andrew@xxxxxxx; atenart@xxxxxxxxxx; Liron Himi
> > > <lironh@xxxxxxxxxxx>; Dana Vardi <danat@xxxxxxxxxxx>
> > > Subject: [EXT] Re: [PATCH net-next] net: mvpp2: Add parsing support
> > > for different IPv4 IHL values
> > >
> > > External Email
> > >
> > > ----------------------------------------------------------------------
> > > On Tue, Apr 13, 2021 at 11:45:31AM +0300, stefanc@xxxxxxxxxxx wrote:
> > > > From: Stefan Chulski <stefanc@xxxxxxxxxxx>
> > > >
> > > > Add parser entries for different IPv4 IHL values.
> > > > Each entry will set the L4 header offset according to the IPv4 IHL field.
> > > > L3 header offset will set during the parsing of the IPv4 protocol.
> > >
> > > What is the impact of this commit? Is something broken at the moment,
> > > if so what? Does this need to be backported to stable kernels?
> > >
> > > These are key questions, of which the former two should be covered in
> > > every commit message so that the reason for the change can be known.
> > > It's no good just describing what is being changed in the commit
> > > without also describing why the change is being made.
> > >
> > > Thanks.
> >
> > Due to missed parser support for IP header length > 20, RX IPv4 checksum
> > offload fail.
> >
> > Regards.
>
> Currently driver set skb->ip_summed = CHECKSUM_NONE and checksum done by software.
> So this just improve performance for packets with IP header length > 20.
> IMO we can keep it in net-next.
>
> Stefan.

Please update the commit message in v2 with the explanation.

Also - is there an easy way to test it? L3 forwarding with forced header length?

Thanks,
Marcin