Re: [Qemu-devel] qemu_power_down_request handling

[Bhushan Bharat-R65777]

> -----Original Message-----
> From: Alexander Graf [mailto:address@hidden
> Sent: Monday, April 16, 2012 1:47 PM
> To: Bhushan Bharat-R65777
> Cc: address@hidden; Wood Scott-B07421
> Subject: Re: qemu_power_down_request handling
> 
> 
> On 16.04.2012, at 10:07, Bhushan Bharat-R65777 wrote:
> 
> > Hi All,
> >
> > The "-watchdog-action shutdown" uses the monitor system_shutdown mechanism 
> > but
> this does not actually powerdown the system.
> >
> > In code, If there is pending powerdown_request
> (qemu_system_powerdown_request() called) then it try to raise an irq. What is
> that irq supposed to do. Currently it in NULL pointer so does not do anything.
> >
> > Code snapshot -- vl.c : main_loop_should_exit()
> >
> > ....
> >    if (qemu_powerdown_requested()) {
> >        monitor_protocol_event(QEVENT_POWERDOWN, NULL);
> >        qemu_irq_raise(qemu_system_powerdown);
> >    }
> > . . . .
> >
> > Is the powerdown_request handling not complete?
> 
> The watchdog shutdown event is a soft power off. Imagine a PC where you press
> the power button, the OS gets notified through ACPI that it's supposed to shut
> down and shuts down the machine.
> 
> I don't know of any BookE system that has a comparable mechanism. We could
> implement it through qemu-ga and fall back to hard power off maybe?

Till someone develop this interface, does it make sense to use 
qemu_system_shutdown_request() rather than qemu_system_powerdown_request() for 
"-watchdog-action shutdown" ?

Thanks
-Bharat