Re: [PATCH v4 2/2] xen: add helpers to allocate unpopulated memory

From: Roger Pau Monné
Date: Thu Aug 13 2020 - 03:54:30 EST

On Thu, Aug 13, 2020 at 08:33:37AM +0100, Christoph Hellwig wrote:
> On Tue, Aug 11, 2020 at 11:44:47AM +0200, Roger Pau Monne wrote:
> > If enabled (because ZONE_DEVICE is supported) the usage of the new
> > functionality untangles Xen balloon and RAM hotplug from the usage of
> > unpopulated physical memory ranges to map foreign pages, which is the
> > correct thing to do in order to avoid mappings of foreign pages depend
> > on memory hotplug.
> So please just select ZONE_DEVICE if this is so much better rather
> than maintaining two variants.

We still need to other variant for Arm at least, so both need to be
maintained anyway, even if we force ZONE_DEVICE on x86.

Thanks, Roger.