Re: [Qemu-devel] [PATCH 2/7] Replace VMSTOP macros with a proper QemuState type

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 08 Aug 2011 16:54:16 +0300
Avi Kivity <avi@redhat.com> wrote:

> On 08/08/2011 04:47 PM, Luiz Capitulino wrote:
> > >
> > >  Well, then, the user won't know something happened and will happily
> > >  resume the guest, like I outlined above.
> >
> > I think it makes sense to return an error in the monitor if the user
> > tries to stop qemu when it's already stopped. Not sure if it will do what you
> > think it should do, but we should always tell the user when we're unable to
> > carry his/her orders.
> >
> > But it does make sense to me to not allow stopping twice. First because it
> > doesn't make sense to stop something which is not moving and second because
> > what else can stop the vm if it's already stopped?
> >
> > Maybe vm_stop() should return an error, but I think this goes beyond this
> > series.
> >
> 
> This is why I suggested a reference count.  In this case, we can always 
> stop the guest "twice", because we don't lost information when we resume.

I could give it a try in the near future, as I really think it's independent
from this series, but I still don't understand what can stop an already stopped
VM besides the user. This is a real question, is it really possible?

If only the user can do that, then the refcount is overkill as just returning
an error will do it.