Re: [RFC PATCH 4/5] acpi/hmat: Register special purpose memory as a device

[Christoph Hellwig]

On Thu, Apr 04, 2019 at 12:08:49PM -0700, Dan Williams wrote:
> Memory that has been tagged EFI_SPECIAL_PURPOSE, and has performance
> properties described by the ACPI HMAT is expected to have an application
> specific consumer.
> 
> Those consumers may want 100% of the memory capacity to be reserved from
> any usage by the kernel. By default, with this enabling, a platform
> device is created to represent this differentiated resource.

This sounds more than weird.  Since when did we let the firmware decide
who can use the memory?