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

[Programmingkid]

On Aug 27, 2015, at 11:19 AM, Daniel P. Berrange wrote:

> 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.

This QOM path might be better than nothing. Hopefully someone will make this
patch and share it with us.