[ewg] [RFC][0/2] IPoIB UD 4K MTU support

[Shirley Ma]

Here is a patchset to enable IPoIB UD 4K MTU support for any IB fabric
where the max IPoIB payload can be up to 4K. This patchset uses two S/G
buffers when IPoIB payload + IB_GRH header size is greater than
PAGE_SIZE. The first buffer size is IB_GRH_HEAD + IPOIB_ENCAP_LEN. The
second buffer is the data.

Please review it.

Thanks
Shirley