Re: [Qemu-devel] [PATCH 04/14] qdev: take ownership of id pointer

[Gerd Hoffmann]

On 09/19/11 18:27, Anthony Liguori wrote:
> On 09/19/2011 02:34 AM, Gerd Hoffmann wrote:
> > FYI: Keeping the pointer to the QemuOpts has one more reason: It will
> > free the
> > QemuOpts on hot-unplug, which is needed to free the id from QemuOpts
> > point of
> > view, which in turn allows to re-use the id when hot-plugging the same
> > (or
> > another) device later on.
>
> You mean, tie QemuOpts life cycle to devices life cycle

Yes.

> such that you
> cannot accidentally create a non-device QemuOpts that conflicts with the
> id of a device?

Device QemuOpts have their own id namespace, so this is just about 
conflicts within devices.  This ...

   device_add e1000,id=nic1
   device_del nic1
   device_add e1000,id=nic1

... will work only if you free the QemuOpts when deleting a device, 
otherwise QemuOpts will complain that nic1 is used already.

cheers,
  Gerd