Hi, On 8/5/19 8:09 PM, kumaraparameshwaran rathinavel wrote: > Hi All, > > I had recently tried using TSO on the DPDK virtio guest driver and I get > the TCP checksum errors at the client side. I tried running iperf and > Apache bench > > We have been using the same TCP/IP stack for other DPDK pmd drivers and > they are working fine. I did notice that incase of virtio alone we do > calculate the IP payload in pseudo check sum, please correct me if I am > wrong. This is the guest side implementation. Is this applicable for all > versions of qemu virtio > > In the host the OVS is run in a Kolla inside container and it is in > non-dpdk mode. The tcpdump from the physical interface shows that the > packet is not modified from the way it was sent by the guest. > > After the checksum errors the TCP stack of the guest sends the MTU sized > packet for which the TSO failed and this time the checksum at the client > side did not fail. In the client I had disabled GRO and LRO, so that we > compute checksum on each frame. > > Also the checksum errors are seen only when the VMs communicating are > present in different physical host, when VMs in same host I do not see any > checksum errors. > > Please let me know if such issues were seen earlier and any pointers on > debugging further would be helpful.
Which version of DPDK are you using? There was a fix recently that may fix your issue [0]: commit 00a5ea02e12fc1409901c0149ce87c28a286ea60 Author: Dilshod Urazov <dilshod.ura...@oktetlabs.ru> Date: Mon Jun 17 12:31:37 2019 +0100 net/virtio: add Tx preparation Virtio requires pseudo-header checksum in TCP/UDP checksum to do offload, but it was lost when Tx prepare is introduced. Also rte_validate_tx_offload() should be used to validate Tx offloads. Also it is incorrect to do virtio_tso_fix_cksum() after prepend to mbuf without taking prepended size into account, since layer 2/3/4 lengths provide incorrect offsets after prepend. Fixes: 4fb7e803eb1a ("ethdev: add Tx preparation") Cc: sta...@dpdk.org Signed-off-by: Dilshod Urazov <dilshod.ura...@oktetlabs.ru> Signed-off-by: Andrew Rybchenko <arybche...@solarflare.com> Reviewed-by: Tiwei Bie <tiwei....@intel.com> > Thanks, > Param > https://www.mail-archive.com/dev@dpdk.org/msg134448.html