Re: [PATCH 5/5] memremap: provide a not device managed memremap_pages

Christoph Hellwig
2019-08-12T15:00:12Z

On Mon, Aug 12, 2019 at 08:20:58PM +0530, Bharata B Rao wrote:
> On Sun, Aug 11, 2019 at 10:12:47AM +0200, Christoph Hellwig wrote:
> > The kvmppc ultravisor code wants a device private memory pool that is
> > system wide and not attached to a device. Instead of faking up one
> > provide a low-level memremap_pages for it. Note that this function is
> > not exported, and doesn't have a cleanup routine associated with it to
> > discourage use from more driver like users.
>
> The kvmppc secure pages management code will be part of kvm-hv which
> can be built as module too. So it would require memremap_pages() to be
> exported.
>
> Additionally, non-dev version of the cleanup routine
> devm_memremap_pages_release() or equivalent would also be requried.
> With device being present, put_device() used to take care of this
> cleanup.

Oh well. We can add them fairly easily if we really need to, but I
tried to avoid that. Can you try to see if this works non-modular
for you for now until we hear more feedback from Dan?