Re: [PATCH for-6.0 6/6] qapi: Deprecate 'query-kvm'

[Peter Krempa <pkrempa@redhat.com>]

On Fri, Nov 27, 2020 at 10:50:59 +0000, Daniel Berrange wrote:
> Copying libvir-list for the deprecation warning.
> 
> 
> On Mon, Nov 16, 2020 at 04:10:11PM +0300, Roman Bolshakov wrote:
> > 'query-accel' QMP command should be used instead.
> > 
> > Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
> > ---
> >  qapi/machine.json | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> docs/system/deprecated.rst needs to be updated for any deprecation
> to be visible to consumers of QEMU.

On behalf of libvirt I'd like to ask to consider cases where the
replacement for a deprecated feature is added in the same release as the
deprecation happens, to treat the replacement as API stable at merge
time.

Any changes to the command after the series is merged with a deprecation
of the old should be consulted with the libvirt team as we might
actually have already added support for the new approach. Considering it
as "it wasn't released so we can change it" may introduce breakage given
that the relase cycles of libvirt and qemu are not in sync.

We try hard to stay on top of such changes by using the new interface as
soon as possible, but that is very hard if the replacement changes
during the dev cycle.