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

[Daniel Vetter]

On Thu, Aug 13, 2020 at 09:54:20AM +0200, Roger Pau Monné wrote:
> 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.

Why does arm not have ZONE_DEVICE?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch