[dpdk-dev] ixgbe and UDP with zero checksum

[Wang, Haiyue]

Hi Paolo,

> -----Original Message-----
> From: Paolo Valerio <pvalerio at redhat.com>
> Sent: Wednesday, January 27, 2021 21:50
> To: dev at dpdk.org
> Cc: Guo, Jia <jia.guo at intel.com>; Wang, Haiyue <haiyue.wang at intel.com>; Aaron Conole
> <aconole at 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. :(

+		/*
+		 * 82599 errata, UDP frames with a 0 checksum can be marked as
+		 * checksum errors.
+		 */
+		if ((pkt_info & IXGBE_RXDADV_PKTTYPE_UDP) &&
+		    (adapter->hw.mac.type == ixgbe_mac_82599EB))
+			return;

> 
> Regards,
> Paolo