Re: [Qemu-devel] Re: [PATCH 0/4] Machine config files

[Gerd Hoffmann]

On 07/06/09 18:12, Avi Kivity wrote:
> On 07/06/2009 05:40 PM, Gerd Hoffmann wrote:
> > It might make sense to integrate savevm callbacks into qdev, then
> > you'd have actually a chance to figure which driver belongs to your
> > piece of savevm state.
>
> That's my preference. The very first pass iterates the device tree and
> serializes it.

Sure, needs to happen.

I meant something else though:  Instead of having the drivers call 
register_savevm() in there init functions add section name and 
savevm/loadvm function pointers to qdevs DeviceInfo.  That will add the 
missing link section name -> driver.  That alone will *not* provide the 
position in the device tree though.  And I suspect making the transition 
without breaking backward compatibility could be quite tricky too.  So 
I'm not sure how useful that actually is, although it surely would be 
much cleaner from a design point of view.

> > I suspect it isn't enougth to make it work though, you still need to
> > know the position of the device in the device tree. To answer
> > questions like "is your pci device behind a bridge and if so which one?".
>
> Isn't that info provided by qdev?

Yep, it is.

Serialize qdev tree (into fdt or whatever else), send it over wire 
first, recreate qdev tree on the other side (including save/load 
callback registration), then parse everything else.  That is how I wanna 
have it work some day ...

cheers,
  Gerd