Re: [Qemu-devel] Should we auto-generate IDs?

[Daniel P. Berrange]

On Thu, Aug 27, 2015 at 11:13:25AM -0400, Programmingkid wrote:
> > 
> >> What is wrong with having a predictable ID?
> >> 
> > 
> > As Daniel and Eric have noted, it could be nice to have a predictable
> > ID.  My concern with a predictable ID is that it creates, across
> > multiple sub-systems, an ABI that we will then need to make sure
> > always works.
> > 
> > For instance, I don't want management software or a user to rely on us
> > parsing devices, or image filenames / block driver states in a certain
> > order, and then anticipate the ID name.  I am concerned about creating
> > an interface that may inadvertently "break" later on, and imposing a
> > burden on QEMU that isn't reasonable.  Perhaps it is enough to just
> > rely on documentation for this, without enforcing it in the scheme.
> 
> If we do nothing, QEMU stays broken. The monitor command device_del
> and others that need an ID will not work still. Hopefully any changes we
> make to QEMU will be robust enough stand the test of time.

That is not correct. It is possible for us to fix object_del / device_del
to accept the QOM object path. It isn't pretty but it is a solution that
gives everything a stable unique path ID to use for deletion even if the
user forgets to give a pretty path-less ID.

Regards,
Daniel
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