Re: [Qemu-devel] [PATCH] monitor: fix expected qmp_capabilities error description regression

[Peter Xu]

On Sat, Mar 24, 2018 at 06:41:04AM -0500, Eric Blake wrote:
> On 03/23/2018 08:41 PM, Peter Xu wrote:
> 
> > > There have been quite a few patch ideas across multiple threads related to
> > > OOB fallout.  Hopefully I can keep straight which patches are intended for
> > > 2.12 (anything that fixes a bug, like this one, is a good candidate,
> > 
> > I'll mark patches with "for-2.12" if there are.
> > 
> > > and it
> > > would be nice if we can undo the temporary reversion of exposing OOB if we
> > > can solve all the issues that iotests exposed).
> > 
> > IMHO it'll still be risky considering what has already reported.
> > 
> > Here's my plan, hopefully to make everyone happy - we keep OOB turned
> > off for 2.12 and even later.  In 2.13, I'll post some new patches to
> > add a new monitor parameter to allow user to enable OOB explicitly,
> > otherwise we never enable it.  After all, for now the only real user
> > should be postcopy. Then we don't need to struggle around all these
> > mess.  What do you think?
> 
> If you're going to add a CLI parameter that must be specified for OOB to
> even be advertised, then it is MUCH less invasive to existing clients (it
> does mean that opting in to OOB now requires the command line argument AND
> the capability request during qmp_capabilities) - as such, enabling the
> opt-in during 2.12 is less controversial, and I see no reason to defer it to
> 2.13, especially if you want to maximize testing of the new feature to shake
> out the bugs it encounters.
> 
> If you want to be cautious, name the command-line parameter --x-oob for now,
> we can rename it later to drop the x- prefix, or remove the parameter
> altogether if we decide by opting in via merely qmp_capabilities is
> sufficient.

Hmm, it seems I don't even need to wait. :-)

I'll prepare something soon (together with some existing known fixes).

Thanks!

-- 
Peter Xu