Re: [PATCH v2 (BROKEN) 0/6] migration: bring improved savevm/loadvm/delvm to QMP

[Markus Armbruster]

Kevin Wolf <kwolf@redhat.com> writes:

> Am 27.08.2020 um 13:06 hat Markus Armbruster geschrieben:
>> Daniel P. Berrangé <berrange@redhat.com> writes:
>> 
>> > On Wed, Aug 26, 2020 at 07:28:24PM +0100, Daniel P. Berrangé wrote:
>> >> On Wed, Aug 26, 2020 at 05:52:06PM +0200, Markus Armbruster wrote:
>> >> > Open questions:
>> >> > 
>> >> > * Do we want the QMP command to delete existing snapshots with
>> >> >   conflicting tag / ID, like HMP savevm does?  Or do we want it to fail
>> >> >   the transaction?
>> >> 
>> >> The intent is for the QMP commands to operate exclusively on
>> >> 'tags', and never consider "ID".
>> >
>> > I forgot that even HMP ignores "ID" now and works exclusively in terms
>> > of tags since:
>> >
>> >
>> >   commit 6ca080453ea403959ccde661030ca16264acc181
>> >   Author: Daniel Henrique Barboza <danielhb413@gmail.com>
>> >   Date:   Wed Nov 7 11:09:58 2018 -0200
>> >
>> >     block/snapshot.c: eliminate use of ID input in snapshot operations
>> 
>> Almost a year after I sent the memo I quoted.  It's an incompatible
>> change, but nobody complained, and I'm glad we got this issue out of the
>> way.
>
> FWIW, I would have ignored any complaint about incompatible changes in
> HMP. It's not supposed to be a stable API, but UI.

The iffy part is actually the loss of ability to access snapshots that
lack a name.  Complaints about that would have been valid, I think.
Fortunately, there have been none.