Re: [Qemu-devel] [PATCH v4] qdev: DEVICE_DELETED event

[Anthony Liguori <aliguori@us.ibm.com>]

"Michael S. Tsirkin" <mst@redhat.com> writes:

> On Fri, Mar 08, 2013 at 07:36:28AM -0600, Anthony Liguori wrote:
>> Markus Armbruster <armbru@redhat.com> writes:
>> 
>> > "Michael S. Tsirkin" <mst@redhat.com> writes:
>> >
>> >> On Thu, Mar 07, 2013 at 08:57:52PM +0100, Markus Armbruster wrote:
>> >>> "Michael S. Tsirkin" <mst@redhat.com> writes:
>> >>> 
>> >>> > libvirt has a long-standing bug: when removing the device,
>> >>> > it can request removal but does not know when the
>> >>> > removal completes. Add an event so we can fix this in a robust way.
>> >>> >
>> >>> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>> >>> 
>> >>> Speaking as the acting QMP maintainer, just to avoid misunderstandings:
>> >>> there's disagreement on the event's design, namely when it should fire,
>> >>> and how it should name the device.  I don't want the discussion
>> >>> preempted by a commit.
>> >>
>> >> Yes, you are asking for more functionality, but can I add this in a
>> >> follow-up commit please?  I prefer this patch as is, as it can be
>> >> backported to stable branches and downstreams.  Upstream a follow up
>> >> patch can add fields and more triggers which won't apply to any
>> >> downstreams.
>> >
>> > If you want to address my review comments in a separate patch, go right
>> > ahead.  Please post both together as a series, for coherent review and
>> > to simplify patch tracking.
>> >
>> > I'm asking for two things:
>> >
>> > 1. Event member path.  Fair to call this "more functionality".  I agree
>> >    that backporting it to pre-QOM versions isn't practical.
>> >
>> > 2. Sane event trigger condition: on any device deletion, not just when
>> >    the device happens to have a qdev ID.  This isn't "more", it's
>> >    "different".
>> 
>> Ack.
>> 
>> Regards,
>> 
>> Anthony Liguori
>
>
> So how does one get the path that you require?
>
> ERROR:qom/object.c:1011:object_get_canonical_path: assertion failed:
> (prop != NULL)

Can you share your patch?  This means something is wrong.  All devices
have a canonical path.

Regards,

Anthony Liguori