On 12/6/2016 6:25 PM, Yong Wang wrote: >> -----Original Message----- >> From: Ananyev, Konstantin [mailto:konstantin.anan...@intel.com] >> Sent: Sunday, December 4, 2016 4:11 AM >> To: Yong Wang <yongw...@vmware.com>; Thomas Monjalon >> <thomas.monja...@6wind.com> >> Cc: Harish Patil <harish.pa...@qlogic.com>; dev@dpdk.org; Rahul Lakkireddy >> <rahul.lakkire...@chelsio.com>; Stephen Hurd >> <stephen.h...@broadcom.com>; Jan Medala <j...@semihalf.com>; Jakub >> Palider <j...@semihalf.com>; John Daley <johnd...@cisco.com>; Adrien >> Mazarguil <adrien.mazarg...@6wind.com>; Alejandro Lucero >> <alejandro.luc...@netronome.com>; Rasesh Mody >> <rasesh.m...@qlogic.com>; Jacob, Jerin <jerin.ja...@cavium.com>; >> Yuanhan Liu <yuanhan....@linux.intel.com>; Kulasek, TomaszX >> <tomaszx.kula...@intel.com>; olivier.m...@6wind.com >> Subject: RE: [dpdk-dev] [PATCH v12 0/6] add Tx preparation >> >> Hi >> >> >> >>>> >> >>>> 2016-11-30 17:42, Ananyev, Konstantin: >> >>>>>>> Please, we need a comment for each driver saying >> >>>>>>> "it is OK, we do not need any checksum preparation for TSO" >> >>>>>>> or >> >>>>>>> "yes we have to implement tx_prepare or TSO will not work in this >> >>>> mode" >> >>>>>>> >> >>>>>> >> >>>>>> qede PMD doesn’t currently support TSO yet, it only supports Tx >> >>>> TCP/UDP/IP >> >>>>>> csum offloads. >> >>>>>> So Tx preparation isn’t applicable. So as of now - >> >>>>>> "it is OK, we do not need any checksum preparation for TSO" >> >>>>> >> >>>>> Thanks for the answer. >> >>>>> Though please note that it not only for TSO. >> >>>> >> >>>> Oh yes, sorry, my wording was incorrect. >> >>>> We need to know if any checksum preparation is needed prior >> >>>> offloading its final computation to the hardware or driver. >> >>>> So the question applies to TSO and simple checksum offload. >> >>>> >> >>>> We are still waiting answers for >> >>>> bnxt, cxgbe, ena, nfp, thunderx, virtio and vmxnet3. >> >>> >> >>> The case for a virtual device is a little bit more complicated as packets >> offloaded from a virtual device can eventually be delivered to >> >>> another virtual NIC or different physical NICs that have different offload >> requirements. In ESX, the hypervisor will enforce that the packets >> >>> offloaded will be something that the hardware expects. The contract for >> vmxnet3 is that the guest needs to fill in pseudo header checksum >> >>> for both l4 checksum only and TSO + l4 checksum offload cases. >> >> >> >> Ok, so at first glance that looks to me very similar to Intel HW >> requirements. >> >> Could you confirm would rte_net_intel_cksum_prepare() >> >> also work for vmxnet3 or some extra modifications are required? >> >> You can look at it here: https://urldefense.proofpoint.com/v2/url?u=http- >> 3A__dpdk.org_dev_patchwork_patch_17184_&d=DgIGaQ&c=uilaK90D4TOV >> oH58JNXRgQ&r=v4BBYIqiDq552fkYnKKFBFyqvMXOR3UXSdFO2plFD1s&m=NS >> 4zOl2je_tyGhnOJMSnu37HmJxOZf-1KLYcVsu8iYY&s=dL-NOC- >> 18HclXUURQzuyW5Udw4NY13pKMndYvfgCfbA&e= . >> >> Note that for Intel HW the rules for pseudo-header csum calculation >> >> differ for TSO and non-TSO case. >> >> For TSO length inside pseudo-header are set to 0, while for non-tso case >> >> It should be set to L3 payload length. >> >> Is it the same for vmxnet3 or no? >> >> Thanks >> >> Konstantin >> > > Yes and this is the same for vmxnet3. >
This means vmxnet3 PMD also should be updated, right? Should that update be part of tx_prep patchset? Or separate patch? >>> >> >>>>> This is for any TX offload for which the upper layer SW would have >> >>>>> to modify the contents of the packet. >> >>>>> Though as I can see for qede neither PKT_TX_IP_CKSUM or >> >>>> PKT_TX_TCP_CKSUM >> >>>>> exhibits any extra requirements for the user. >> >>>>> Is that correct? >> >> >
