[ofa-general] [PATCH] IPoIB UD 4K MTU support

[Roland Dreier]

 > It could be fixed by being able to set max IPv4 MTU 64k-4 and IPv6 MTU
 > 4G-4.

But we could never receive a message of size even close to 4G into a
single skb.  So IPv6 at least will always be a problem.

Even for the IPv4 case I think CM is OK: the two sides exchange the
size of the message they can receive, so the not quite 64K MTU we
support should be fine.  The current CM implementation handles pmtu
etc when a remove system has a smaller receive side.