> > > My 10GbE NIC does not do HW VLAN tag insertion/removal (we concluded > > > there was no performance benefit). On several OSes, I'm forced to > > > claim the device does HW VLAN tag support (and do tag > > > insertion/removal in the driver) to gain support for the 4 bytes of > > > "margin" (1518, 9018), and/or to get the OS to trust that my device > > > can offload checksum in combination with VLAN frames. > > > > > Hmm, can we make the assumption that supporting margin of greater than 4 > > always implies that a driver can handle offload checksum for VLAN frames? > I > > am not sure whether this is always true. > > Maybe there could be a capability flag for checksum offload in > combination with vlan? There seem to be plenty of bits free in the > 32-bit cap data for MAC_CAPAB_HCKSUM. > I am adding this in the PSARC fast-track, and the diffs are posted below. The following link is also updated
http://opensolaris.org/os/project/clearview/uv_addendum_fasttrack Thanks - Cathy ------------------------------------------------------------------------ $ diff -u uv_addendum_fasttrack.old uv_addendum_fasttrack --- uv_addendum_fasttrack.old Thu Sep 13 14:36:40 2007 +++ uv_addendum_fasttrack Thu Sep 13 17:57:11 2007 @@ -114,6 +114,16 @@ Commitment level: Consolidation Private + ** HCKSUM_VLANCKSUM bit of MAC_CAPAB_HCKSUM + + The HCKSUM_VLANCKSUM bit can be set in combination with other + MAC_CAPAB_HCKSUM bits (HCKSUM_INET_PARTIAL, HCKSUM_INET_FULL_V4, + HCKSUM_INET_FULL_V6, or/and HCKSUM_IPHDRCKSUM), to indicate that + a MAC is capable of doing the specified hardware checksum offloading + for VLAN frames. + + Commitment level: Consolidation Private + * GLDv2 changes ** gldm_margin field in gld_mac_info_t @@ -132,6 +142,25 @@ Commitment level: Committed + ** GLDv2 hardware checksum offloading for VLAN frames + + We will not add any GLDv2 equivalence of the GLDv3 HCKSUM_VLANCKSUM + bit, because: + + - the current GLDv2 GLD_CAP_CKSUM_XXX (hardware checksum offloading) + capabilities are consolidation private. Therefore there is no hardware + checksum capable GLDv2 driver outside ON. + + - with the existence of the GLDv3 framework, we will not add any new + GLDv2 drivers in ON. + + - we can make a simple assumption that a VLAN PPA aware GLDv2 driver + which advertises its hardware checksum capability can correctly + handle VLAN frames as well. + + Therefore, there is no need to extend the GLDv2 hardware checksum + offloading capability for VLAN frames. + Deliverables ============ _______________________________________________ networking-discuss mailing list [email protected]
