Re: [PATCH v2] mm: Only re-generate demotion targets when a numa node changes its N_CPU state

[Dave Hansen]

On 3/14/22 08:13, Oscar Salvador wrote:
> On Mon, Mar 14, 2022 at 09:03:59AM +0800, Huang, Ying wrote:
>> Oscar Salvador <osalvador@xxxxxxx> writes:
>> On host machine, PMEM is always exposed via memory hotplug.  But later
>> on, we found that for guest system it's possible for PMEM to be exposed
>> as normal memory.
> Could you please elaborate on that? How is it done? I would love to hear the
> details.

Qemu, for instance, has a "mem-path" argument.  It's typically used for
using hugetlbfs as guest memory.  But, there's nothing stopping you from
pointing it to a DAX device or a file on a DAX filesystem that's backed
by pmem.