Re: [Qemu-devel] [PATCH 0/9] monitor: enable OOB by default

[Peter Xu <peterx@redhat.com>]

On Tue, Jul 17, 2018 at 08:08:55PM +0800, Peter Xu wrote:

[...]

> > 
> > Whatever we don't address right away we should at least mark FIXME in
> > the source code.
> > 
> > Assuming my list is complete, and my assessments correct, then we're
> > quite close to the point where we can enable OOB.  But since rc1 is
> > tomorrow already, I feel enabling it in 3.0 has become unrealistic.  I
> > understand we need it sooner rather than later for postcopy recovery.
> > However, the current state should be servicable for teaching OOB to
> > libvirt: just follow the recommendation to supply "id" (libvirt always
> > does anyway), pretend COMMAND_DROPPED doesn't exist, and pretend flow
> > control isn't an issue.
> 
> I guess the thing is not about COMMAND_DROPPED; it's about we're going
> to drop the x-oob parameter.  Now we can only use that parameter to
> enable out-of-band, and after we enable it by default we possibly want
> to remove that x-oob parameter.  So we'd better provide a constant way
> for libvirt to enable out-of-band first (and now I'll assume the
> "exec-oob" interface won't change again).  But yes I think we can do
> that after 3.0.

Btw, note that patches 4-7 might still be candidates of bug fixes for
existing out-of-band feature.  It'll drop COMMAND_DROPPED event, but
IMHO it's still better than having a broken flow control for it (and
dropping event declaration is pretty safe even clients implemented
them).  Though the changes are not trivial, so I'll leave the decision
to you on whether we'll still consider them as 3.0 material.  Anyway,
please feel free to let me know if you want me to post them
separately.

Regards,

-- 
Peter Xu