Re: [Xen-devel] Driver domains and hotplug scripts, redux

[Tim Deegan <tim@xxxxxxx>]

Hi, 

At 10:57 +0100 on 31 Jan (1328007457), Roger Pau Monn? wrote:
> That's what I don't get. Booting the driver domain should be no
> problem, because you can also have a xenbackendd running in the Dom0
> to boot the driver domain (or maybe you want to use both Dom0 and
> another DomU as driver domains).
> 
> What I don't get is what you do when you have to boot a PV DomU which
> root HDD is on the driver domain. Dom0 needs the kernel/initrd from
> the HDD (usually extracted using pygrub). Since the HDD is inside the
> driver domain, Dom0 doesn't have access to that image, so there's no
> way to extract the kernel/initrd from the Dom0. What I through is that
> the driver domain has to run pygrub, extract the kernel/initrd, and
> pass both files to the Dom0, but how can we pass those files? libvchan
> seems like the best option, but I would like to head others opinions
> about this.

You could attach to the disk image (using blkfront in dom0 and
blkback/tap/whatever in the driver domain), run pygrub and detach.
That's basically the same thing you have to do with a qcow image in a
traditional dom0.

Or you could use pvgrub to boot the domain, so dom0 code never has to
touch the guets-supplied disk image or kernel.  That seems much better
to me, but maybe it wouldn't work for some existing deployments?

Cheers,

Tim.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel