- Fix the NEEDS_CSUM and DATA_VALID checksum flags. The NEDS_CSUM
checksum is incomplete (partial) so offer a fallback for the driver
to calculate the checksum. Simplify DATA_VALID because we know
the host has validated the checksum.
- Default 4K mbuf clusters for mergeable buffers. May need to
scale this down to 2K clusters in certain configurations such
many queue pairs, big queues (like 4096 in GCP), and low memory.
- Use the MTU when calculated the receive mbuf cluster size
when not doing TSO/LRO. This will need more adjustment once
the MTU feature is supported.