Re: Re: [Xen-devel] Linux hangs during reboot on Jeremy's git kernel

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Feb 08, 2010 at 12:27:41PM -0500, Mike Viau wrote:
> 
> > Date: Mon, 8 Feb 2010 10:48:29 -0500
> > From: konrad.wilk@oracle.com
> > To: mike.viau@sheridanc.on.ca
> > CC: ahmad.hassan@gmail.com; xen-devel@lists.xensource.com; xen-users@lists.xensource.com
> > Subject: [Xen-users] Re: [Xen-devel] Linux hangs during reboot on Jeremy's	git kernel
> > 
> > On Sat, Feb 06, 2010 at 09:58:13AM -0500, Mike Viau wrote:
> > > 
> > > Attached is a screen shot of the last messages I recieve during a system reboot. 
> > > 
> > > Note: The power is never cycled and Linux apprears to hang.
> > > 
> > > Is there something else I can try to resolve this issue?
> > 
> > I have the same issue (AMD development hardware) so I believe we haven't
> > fixed out all the bugs. If you are interested in resolving this I can
> > give you some ideas where to poke in the kernel/hypervisor code.
> > 
> 
> Absolutely,
> what can I do to help!

Need to narow down under what situations the kernel/hypervisor shuts
properly the machine.

For that we need to do a couple of variants:

a). Bare-metal. Boot pv-ops and shutdown. Does it do it?
b). If it does not, try an earlier kernel or a distro supplied one.

If the a) or b) don't work then you have a very unique motherboard
and we will need to play a bit with 'reboot=' command line arguments.
Look in arch/x86/kernel/reboot.c for details.

Lets assume that a) or b) do work. We want to find out what it does
to the machine. You can instrument the code (reboot.c?) and find out
which mechanism it uses.

Make sure the Xen hypervisor uses the same mechanism. You can toggle
those flags with the 'reboot=' arguments (look in arch/x86/shutdown.c)
After that, if you know that the reboot mechanism used by the bare-metal
is the same as the one used by the hypervisor, then there is something
amiss in the hypervisor that will have to be updated.

P.S.
What is weird is that your screenshot says "machine reboot" which only
shows up when you are running on bare-metal. Was that screen shot taken
when pv-ops was running under Xen or bare-metal?