> -----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 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? > >