Re: [dpdk-dev] ixgbe and UDP with zero checksum

["Wang, Haiyue" <haiyue.wang@intel.com>]

+ ARM experts, Feifei and Ruifeng.

Need your further support for ARM NEON path.

https://patchwork.dpdk.org/patch/87617/

> -----Original Message-----
> From: Paolo Valerio <pvalerio@redhat.com>
> Sent: Friday, January 29, 2021 22:20
> To: Wang, Haiyue <haiyue.wang@intel.com>; Yang, Qiming <qiming.yang@intel.com>
> Cc: Guo, Jia <jia.guo@intel.com>; Aaron Conole <aconole@redhat.com>; dev@dpdk.org
> Subject: RE: ixgbe and UDP with zero checksum
> 
> "Wang, Haiyue" <haiyue.wang@intel.com> writes:
> 
> > Hi Paolo,
> >
> >> -----Original Message-----
> >> From: Wang, Haiyue
> >> Sent: Friday, January 29, 2021 10:02
> >> To: Paolo Valerio <pvalerio@redhat.com>
> >> Cc: Guo, Jia <jia.guo@intel.com>; Aaron Conole <aconole@redhat.com>; dev@dpdk.org
> >> Subject: RE: ixgbe and UDP with zero checksum
> >>
> >> > -----Original Message-----
> >> > From: Paolo Valerio <pvalerio@redhat.com>
> >> > Sent: Thursday, January 28, 2021 05:35
> >> > To: Wang, Haiyue <haiyue.wang@intel.com>
> >> > Cc: Guo, Jia <jia.guo@intel.com>; Aaron Conole <aconole@redhat.com>; dev@dpdk.org
> >> > Subject: RE: ixgbe and UDP with zero checksum
> >> >
> >> > "Wang, Haiyue" <haiyue.wang@intel.com> writes:
> >> >
> >> > > Hi Paolo,
> >> > >
> >> > >> -----Original Message-----
> >> > >> From: Paolo Valerio <pvalerio@redhat.com>
> >> > >> Sent: Wednesday, January 27, 2021 21:50
> >> > >> To: dev@dpdk.org
> >> > >> Cc: Guo, Jia <jia.guo@intel.com>; Wang, Haiyue <haiyue.wang@intel.com>; Aaron Conole
> >> > >> <aconole@redhat.com>
> >> > >> Subject: ixgbe and UDP with zero checksum
> >> > >>
> >> > >> Hi,
> >> > >>
> >> > >> performing some tests, I noticed that on ixgbe when receiving UDP
> >> > >> packets with zero checksum (no checksum) over IPv4, the corresponding
> >> > >> ol_flag for the l4 checksum is set to PKT_RX_L4_CKSUM_BAD.
> >> > >>
> >> > >> In particular, this apparently has an impact on OvS using ct() action
> >> > >> where UDP packets with zero checksum are not tracked because of that.
> >> > >
> >> > >
> >> > >>
> >> > >> [1]
> >> > >>
> >> >
> >>
> https://patchwork.ozlabs.org/project/netdev/patch/20090724040031.30202.1531.stgit@localhost.localdomai
> >> > >> n/
> >> > >
> >> > > About 12 years old patch, it is hardware errata. For fixing this,
> >> > > have to always disable vector Rx path for 82599, it seems not a
> >> > > good idea to bring in this workaround. :(
> >> > >
> >> >
> >> > Thanks for the answer.
> >> > Yes, as I mentioned, the patch is old although still meaningful.
> >> > I linked it mostly because it mentions the hw errata.
> >> >
> >>
> >> What's your PCI device ID ? My worked ixgbe:
> >>
> >
> > Sorry, I missed the PKT_RX_L4_CKSUM_BAD information, yes, my NIC have the issue.
> >
> >> 86:00.0 Ethernet controller [0200]: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network
> Connection
> >> [8086:10fb] (rev 01)
> >>
> >> I'm wondering if people will complain that the patch will mark the real bad checksum UDP as
> >
> > Zero checksum is more popular case, please file a bug on https://bugs.dpdk.org/ to trace the fix.
> >
> > Thanks for pointing it out.
> >
> 
> ack, I'm going to file it.
> 
> Thanks,
> Paolo
> 
> >> GOOD. For handling this correctly, looks like driver needs to check the UDP's checksum value,
> >> if zero, then skip the error information, but this makes driver do the network stack things ...
> >>
> >>