Enabling peer to peer device transactions for PCIe devices

[Stephen Bates]

>>
>> The NVMe fabrics stuff could probably make use of this. It's an
>> in-kernel system to allow remote access to an NVMe device over RDMA. So
>> they ought to be able to optimize their transfers by DMAing directly to
>>  the NVMe's CMB -- no userspace interface would be required but there
>> would need some kernel infrastructure.
>
> Yes, that's what I was thinking. The NVMe/f driver needs to map the CMB
> for RDMA. I guess if it used ZONE_DEVICE like in the iopmem patches it
> would be relatively easy to do.
>

Haggai, yes that was one of the use cases we considered when we put
together the patchset.