Re: [Qemu-devel] [PATCH] monitor: Add port write command

[Gleb Natapov]

On Tue, Jul 14, 2009 at 08:30:25PM +0100, Paul Brook wrote:
> > What would be really cool about this change is that we could introduce a
> > new set of commands to manipulate device state.  We could save/restore
> > individual device state and that would allow us to dump device state via
> > the monitor and to manipulate individual fields of the device state.  I
> > think this could be pretty useful for debugging.
> 
> I'd be reluctant to expose the savevm state to the user.
> 
> For debugging qemu I don't see it providing any real benefit over firing up 
> GDB and poking directly at the device directly.
> 
Not all environments where you need to debug things have gdb, qemu
sources or even non striped qemu binary.

> For debugging the guest there is some argument for exposing the device state 
> (preferably via the gdb stub). However I think the savevm data tends to 
> expose 
> too many internal implementation details, rather than the interesting guest 
> state. For most devices I'd expect the IO regions to be a better fit, 
> especially if you want to prevent qemu crashing when the user does invalid 
> writes.
> 
> Paul
> 

--
                        Gleb.