lpar issue for ZONE_DEVICE p2pmem in 4.14-rc

[Stephen Bates]

Oliver

>The alternative approach you mentioned that uses ioremap() should work
>fine though.

Great, thanks for this useful information Oliver. I am working on rebasing the ioremap() 
patch on 4.14 and will let you know how it goes.

> Also, Alexy (+cc) said he was interested in trying this on some real
> hardware. Is there a test suite for p2pmem floating around that he can
> use?

Excellent! I typically use p2pmem-test [1]. You will need at least one NVMe SSD and one p2pmem capable device and you *might* need to place those two devices behind a PCIe switch and configure ACS [2-3] depending on how the CPU RC treats peer to peer PCI TLPs. I am happy to help Alex set this all up so reach out either publically or privately if you like. I just added a (hopefully) decent README to help get people started.

Stephen

[1] https://github.com/sbates130272/p2pmem-test
[2] https://www.supermicro.com/support/faqs/faq.cfm?faq=20732
[3] https://lkml.org/lkml/2017/10/26/678