On Tue, May 29, 2012 at 12:12 PM, ravi kerur <rke...@gmail.com> wrote: > Additional changes are needed here esp. in NIC driver(looked into > e1000e driver code from Intel) as it requires handling of new > eth_types. For these changes I probably need to work with you and > Jesse on how best we can incorporate them.
At this point, I wouldn't worry about getting drivers to handle MPLS offloading. What I was talking about before was about correctness, not performance. Specifically: 1. Sender (say a VM) transmits a TCP packet that uses offloading. 2. OVS inserts a MPLS tag on the packet before sending it on the wire. 3. The NIC needs to be able to parse into the packet but doesn't understand the MPLS tag and doesn't do anything. 4. The packet gets dropped at some point because it's too big or the checksum computation wasn't performed, etc. In order to avoid this situation you need to perform any offloading in software before giving it to the NIC. This can be done generically though and doesn't require any changes to the driver. Eventually you could start updating drivers for NICs that do support MPLS but you'll still need the software fallback path for other cards, so the software emulation is a good place to start. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
