Improvements to the write path (#15, #18 @hannesm)
page_aligned_buffer and io-page dependencywritevmtu : t -> intwrite : t -> size:int -> (buffer -> int) -> (unit, error) result io -> allocation is done by the mirage-net implementation, and the buffer is filled by the upper layers. once filled, it is send out.Result module on 4.04 on Linux.mirage-net-xen for common use