Subject: Re: NetBSD and Xen 2.0
To: Manuel Bouyer <bouyer@antioche.lip6.fr>
From: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
List: port-xen
Date: 12/14/2004 15:17:03
On Tue, Dec 14, 2004 at 04:11:23PM +0100, Manuel Bouyer wrote:
> 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, ...

If you want to get good performance you need to be able to pass mbufs
directly to the driver and control the drivers memory allocation for
received packets.

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

yes, you can use the Linux 2.6 drivers as documentation.

    christian