On Wed, Sep 2, 2015 at 8:38 PM, Tom Herbert <t...@herbertland.com> wrote: > On Wed, Sep 2, 2015 at 9:46 AM, Rustad, Mark D <mark.d.rus...@intel.com> > wrote: >>> On Sep 1, 2015, at 8:17 PM, Tom Herbert <t...@herbertland.com> wrote: >>> >>> I suspect this is not UDP-encapsulation specific, will it work with >>> TCP/IP/IP, TCP/IP/GRE etc.? >> >> It could do more, but this is what has been tested up to this point. >> > Well, please test the those other encapsulations too! It's nice and > all if they get the benefit, but it's really bad news if these changes > were to screw them up (i.e. you don't want users of the GRE, IPIP to > find out that they're now broken). > >>> Isn't there anyway the ixgbe could just be made to NETIF_HW_CSUM? That >>> would be so much more straightforward and support nearly all use cases >>> without needing to jump through all these hoops. >> >> Well, the description says: >> >> --- >> Note: NETIF_F_HW_CSUM is a superset of NETIF_F_IP_CSUM + NETIF_F_IPV6_CSUM. >> It means that device can fill TCP/UDP-like checksum anywhere in the packets >> whatever headers there might be. >> --- >> >> The device can't do whatever, wherever. There is always a limit to the >> offset to the inner headers that can be handled, for instance. >> > If the device does NETIF_F_HW_CSUM then inner/outer headers are > irrelevant at least in the non-GSO case. All the device needs to do is > compute the checksum from start and write the answer at the given > offset. No protocol awareness needed in the device, no need to parse > headers on transmit.
Tom, could you elaborate a little further on the semantics/requirements for devices supporting NETIF_F_HW_CSUM, clearly (as mentioned in > I have the same complaint that ixgbe requires a bunch of driver logic > to offload VXLAN checksum unnecessary instead of just providing > CHECKSUM_COMPLETE which would work with any encapsulation protocol, > require no encapsulation awareness in the device, and should be a much > simpler driver implementation. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
