Re: [Qemu-devel] [PATCH][RESEND] Add monitor command for system_reboot

[Jamie Lokier <jamie@shareable.org>]

Amit Shah wrote:
> On (Wed) Jul 08 2009 [19:02:16], Avi Kivity wrote:
> > On 07/08/2009 06:43 PM, Ryan Harper wrote:
> >>> That suffers from the same problem as a system_reboot command in that
> >>> the guest may never start the shutdown. If that's an acceptable
> >>> limitation, then we might as well implement it directly in QEMU as
> >>> system_reboot so its easily available to everyone. Make 'system_reboot'
> >>> take an optional timeout arg (default to 60 seconds) after which it
> >>> cancels its plans.
> >>>      
> >>
> >> This seems the most reasonable thing to me.  As already mentioned,
> >> system_powerdown already is non-deterministic since the guest could
> >> ignore the ACPI event.
> >>    
> >
> > It could also send the guest to sleep or initiate the self destruct  
> > sequence.  I don't think we should press the power button unless the  
> > user explicitly asked us to.  This means we'll need a guest agent like 
> > Xen.
> 
> This is another use-case for vmchannel (or virtio-serial) where  the user
> exists within qemu.

What happens then the guest is non-responsive because it crashed, or
the agent isn't working, or the guest doesn't support virtio?

Some way to override the guest is needed for all reboot/powerdown options.

"kill -9 $(pidof kvm)" is really unacceptable, but I've had to do it
on several occasions unfortunately.

Ideally, an option to those commands "--force" to ignore the guest and
just do it, and an option like "--timeout-force=5" to behave like
holding down the power button on a real computer.

(It would be nice to be able to change the value of -no-shutdown and
-no-reboot from the monitor, too.)

-- Jamie