Re: pv_ops & gntdev?

[Gerd Hoffmann <kraxel@redhat.com>]

Jeremy Fitzhardinge wrote:
> Gerd Hoffmann wrote:
>> Short question: Do you have plans to port the gntdev userspace driver
>> (the one sitting in drivers/xen/gntdev/ in the 2.6.18 tree) to the
>> pv_ops kernel?
> 
> I poked at it a little bit, but didn't get very far because I wasn't
> sure if anyone actually wants it.

As far I know the plan is to get rid of any page references in xen and
replace those by grants (i.e. xen text console for example).  To get
that done gntdev is required.

> But blktap2 essentially uses the same
> mechanism (or does it actually use gnttab?), and we'd like to get that
> working.

Not sure about blktap2.  blktap1 and gntdev are very simliar though when
looked at from a memory management point of view.  Both map grants into
userspace memory.  blktap is tied to the block protocol, gntdev is
generic.  Quite possible that blktap2 simply uses gntdev.

> What do you want to do with it?

Test my userspace backend drivers.

> Do you want to bring it over?

Well.  I hoped someone did that already ...

cheers,
  Gerd