Re: [Qemu-devel] [PATCH 07/32] qmp: Make "id" optional again even in "oob" monitors

[Markus Armbruster]

Peter Xu <address@hidden> writes:

> On Mon, Jul 02, 2018 at 06:21:53PM +0200, Markus Armbruster wrote:
>> Commit cf869d53172 "qmp: support out-of-band (oob) execution" made
>> "id" mandatory for all commands when the client accepted capability
>> "oob".  This is rather onerous when you play with QMP by hand, and
>> unnecessarily so: only out-of-band commands need an ID for reliable
>> matching of response to command.
>> 
>> Revert that part of commit cf869d53172 for now.  We may still make
>> "id" mandatory for out-of-band commands.
>
> This change should be okay with current implementation when
> out-of-band commands are still in order themselves, though I'm still
> not that confident on whether we really want this change if only for
> the sake of easier usage for human beings.
>
> If we see Libvirt, the real player for QMP - it has the "id" field
> even for in-band commands always.  I'd say the "id" field is really
> helpful for machines, though not that friendly to us.
>
> Basically I'll read it as: machines like "id"s, humans hate "id"s.
> And QMP is Qemu Machine Protocol after all... so not sure whether
> it'll be good we change that for us humans.

"id" being optional doesn't hurt libvirt in any way.  Thus, I see no
need to inconvenience humans.

Daniel has argued[*] for making "id" mandatory with OOB commands.  I'm
not rejecting that argument.  But I needed to get this out in a hurry,
and simply reverting something is quicker than debating and implementing
an improvement.  There's still time to tweak this before the release.


[*] Message-ID: <address@hidden>
https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg08322.html