Subject: Re: NetBSD and Xen 2.0
To: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: port-xen
Date: 12/14/2004 16:11:23
On Tue, Dec 14, 2004 at 02:08:06PM -0000, Christian Limpach wrote:
> > > yes, except I'm not quite sure why you need the pseudo ethernet device
> in
> > > this context?
> >
> > We need to connect the xennet of the virtual machine to something in
> > the domain0 OS, right ?
> 
> yes, but I don't think a generic pseudo ethernet device will work well for
> this, unless you have some in-kernel interface to receive and send packets
> through it.

The pseudo ethernet device has an entry in /dev/ for this from userland.
Nothing prevent opening his device in kernel and do I/O on it, as does
raidframe, ccd, cgd, ...

> I think the backend network driver will be quite similar to the
> frontend driver (if_xennet) except that it needs to take some additional
> steps mapping pages into the unprivileged domain and reclaiming pages from
> the unprivileged domain.
> 
> > Or maybe the sparce trees in the xen2.01 distrib has this ?
> 
> The sparse tree only includes support for NetBSD as an unprivileged domain.
> There are no incentives for us to add domain0 support for NetBSD at the
> moment but I'll certainly support every effort to do so.

I was talking about the linux trees, which I could use as documentation
for what needs to be done ...

--
Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
     NetBSD: 26 ans d'experience feront toujours la difference
--