Re: qemu-upstream stubdom - status?

[Anthony PERARD <anthony.perard@citrix.com>]

On Tue, Apr 08, 2014 at 11:49:43AM +0100, George Dunlap wrote:
> On Mon, Apr 7, 2014 at 9:50 PM, Eric Shelton <eshelton@pobox.com> wrote:
> > Where does this feature stand currently?  It pops up under a couple of names
> > and proposed implementations (e.g., "qemu-xen stubdomains", "qemu-upstream
> > stubdom, Linux", and "qemu-upstream stubdom, BSD libc"), so it seems likely
> > I missed something.
> >
> > If I understand this email from Sept 2013
> > (http://lists.xen.org/archives/html/xen-devel/2013-09/msg02881.html),
> > qemu-xen stubdomains might have made it into 4.4 if the schedule had been
> > slipped a little, suggesting some active effort.  On the other hand, the
> > same email designated the efforts attached to Anthony and Ian as "prognosis:
> > ?".  Anthony released a patchset/branch about a year ago, but that got
> > sidelined in favor of getting Xen on ARM.  However, I did not identify any
> > more recent patches.
> >
> > It remains appealing to make use of the more recent developments in
> > qemu-upstream, but with the isolation provided by a stubdomain.  The many
> > improvements made in teasing driver domains out of dom0 strengthen this
> > appeal (for example, using OpenSolaris as a ZFS-based storage domain).
> >
> > What are the most recent patches or repository for this feature?
> 
> I think stubdomains for qemu-xen should be a blocker for 4.5.
> 
> The only thing that's missing for stubdoms, AFAIK, is an integrated
> way to deploy the stubdom VM in which qemu-xen can run.
> qemu-traditional uses minios with a version of newlib (IIRC) ported to
> it.  The problem at the moment is that qemu-xen requires much more
> from its libc than newlib provides.  There are several potential
> solutions that have been investigated:
> 
> 1. Use Linux with glibc.
[...]

> #1 involves mainly trying to cut down the Linux kernel and the guest
> FS as small as possible.  Anthony spent some time on #1 in the 4.3 and
> 4.4 development cycles, and I think got the image down to 32MB.
> That's still fairly large, however; and I think he got stuck trying to
> integrate an image builder into the Xen build system.
[...]

> If you're looking for a solution to use right now, I'm sure Anthony
> can point you to wherever he left off.

I have this branch that is the most recent work I have:
git://xenbits.xen.org/people/aperard/xen-unstable.git
branch: stubdom

`make -C stubdom-linux` should make you an image.

Unfortunatly, there is no video output that can be seen, so a guest is
only accessible through the serial console or the network. And there are
probably many other issues.

Hope that help,

-- 
Anthony PERARD