On Wed, Nov 9, 2016 at 3:16 AM, 张东亚 <fortitude.zh...@gmail.com> wrote: > Hi Alexander, > > Thanks a lot for your reply, the following code is excerpted from function > ixgbe_probe in ixgbe_main.c of 4.1.5 driver code. > > #ifdef HAVE_ENCAP_TSO_OFFLOAD > netdev->features |= NETIF_F_GSO_UDP_TUNNEL; > #endif
As far as I know that line has no effect other than just being confusing. Without the line being set in hw_enc_features it has no real effect. > As you can see, its controlled by a macro which will be defined with 3.10+ > kernel, that why make be think it will support the feature, however the vlan > device will not have this feature set because the driver does not set it to > the vlan_features field, so I agree at least on my 3.10.45 kernel with 4.1.5 > ixgbe driver, VXLAN offload will not work on the vlan device of a physical > 82599 device. It won't work in general. The problem is the 82599 does not support VXLAN offload. The reason why GSO_PARTIAL and TSO_MANGLEID work is because we lie to the hardware about what is there. We end up treating the outer transport, inner MAC and network headers as one giant set of IP options. > So I think this feature is turned on. It isn't. It was a bit that was just being set incorrectly and none of this change ever made it into the Linux kernel version of the driver. > I have also checked the GSO_PARTIAL and TSO_MANGLEID flag in the 4.7+ > kernel, seems the two features will also set to the vlan_feature of the > device, which make me wonder 4.7+ kernel shipped ixgbe driver will solve my > question, I will give a try, I am also keen to hear any suggestion from you. Unfortunately last I knew the hw_enc_features only gets to carry the HW_CSUM and SG flags for the VLANs. So you should see improved performance for ixgbe as it now advertises HW_CSUM, but it still won't have TSO support for UDP tunnels. > Thanks a lot. No problem. Hopefully I have helped to explain some of this. The fact is it is going to take time to get all of the features standardized as at this point we have features for VLANs, MPLS, and UDP/GRE tunnels. It will take some time to handle the mixing and matching of features for these. - Alex ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
