Re: [Xen-devel] [PATCH v2 0/3] Add support for NetBSD gntdev

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Fri, Nov 30, 2012 at 10:43:21AM +0000, Ian Campbell wrote:
> On Fri, 2012-11-30 at 10:38 +0000, Manuel Bouyer wrote:
> > On Fri, Nov 30, 2012 at 10:32:32AM +0000, Ian Campbell wrote:
> > > libxl only selects the backend itself if the caller doesn't provide one.
> > > If the caller sets the backend field !=  UNKNOWN then libxl will (try)
> > > and use it. This field is exposed by xl via the backendtype= key in the
> > > disk configuration
> > > http://xenbits.xen.org/docs/unstable/misc/xl-disk-configuration.txt
> > 
> > thanks for pointing this out.
> > I guess qdisk is the qemu backend, and tap would be the in-kernel backend ?
> 
> qdisk == qemu, tap == blktap, phy == in kernel.

OK; but then, how does the script called by xenbackendd know what setup
is should do ? With xm, it would get a string in the form
phy:/dev/wd0e
or
file:/domains/foo.img

but from what I've understant, this syntax is deprecated now ?

> 
> > Is there a way to specify in a config file which default xl should use ?
> 
> backendtype=phy in your disk configure string will do it. Or did you
> mean globally? In that case no (or not AFAIK).

Yes, I mean globally.

> 
> That's not to say it couldn't be made configurable, but someone would
> have to figure out a sensible looking patch. You'd probably want a
> per-format setting?

I guess so, but I've not played with the new tools yet.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
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