Re: [RFC 1/8] Introduce Peer-to-Peer memory (p2pmem) device

From: Logan Gunthorpe
Date: Sat Apr 01 2017 - 18:17:10 EST


Hey,

On 31/03/17 08:17 PM, okaya@xxxxxxxxxxxxxx wrote:
> See drivers/pci and drivers/acpi directory.

The best I could find was the date of the firmware/bios. I really don't
think that makes sense to tie the two together. And really the more that
I think about it trying to do a date cutoff for this seems crazy without
very comprehensive hardware testing done. I have no idea which AMD chips
have decent root ports for this and then if we include all of ARM and
POWERPC, etc there's a huge amount of unknown hardware. Saying that the
system's firmware has to be written after 2016 seems like an arbitrary
restriction that isn't likely to correlate to any working systems.

I still say the only sane thing to do is allow all switches and then add
a whitelist of root ports that are known to work well. If we care about
preventing broken systems in a comprehensive way then that's the only
thing that is going to work.

Logan