NOTE: On powerpc64le RDMA works fine in the userspace with libmlx5, but on powerpc64 it does not. The problem is that contrib/ofed/libmlx5/doorbell.h checks for SIZEOF_LONG but this macro exists on neither powerpc64* nor amd64. Thus, the file silently goes to the fallback function written for 32-bit architectures. It works fine on little-endian architectures, but causes a hard fail on big-endian. It's possible it may also cause some runtime issues on little-endian. Thus, on powerpc64 I verified that RDMA works with krping.