[fedora-virt] F19: replacing chardev patches with upstream ones

[Amit Shah]

On (Tue) 23 Apr 2013 [10:32:56], Cole Robinson wrote:
> On 04/23/2013 01:57 AM, Amit Shah wrote:
> > Hello,
> > 
> > Fedora has carried flow control patches for qemu chardevs since a very
> > long time now.  They weren't upstream, and they were required for
> > spice, usb-redir to work properly and not freeze the guest.
> > 
> > Upstream qemu has now merged an alternative implementation of the same
> > concept, and most of the bugs have been shaken out upstream (we don't
> > know of any known bugs now).  So I'm of the view we should replace
> > the older patches in F19's qemu with the backport of the newer,
> > upstream ones.
> > 
> > Is this fine?  I can work with Cole / Hans who have been keeping the
> > older patches uptodate on Fedora to replace the patches.
> > 
> 
> If the backport is fairly clean and self contained it should be okay, but
> can't say I'm excited about it. What's the benefit besides more testing of the
> new code? Yes we get to drop the old patches but at this point they are a long
> tested known quantity. If it was a month ago I'd be less resistant but this
> will be past the alpha.

Yes, I was concerned about the timing too.

> I'll leave it to your discretion but if the backport is pulling in unrelated
> patches so things apply cleanly, or needs non-trivial alteration to work on
> 1.4, we should re-evaluate.

I haven't tried the backport yet.

Since people haven't been finding bugs in the older code, it's
obviously safer to just keep it and drop all the patches in rawhide
once we rebase to qemu-1.5 (1.5 will contain all the new upstream
work).  OTOH getting testing for the new code will be a big positive.
>From all indications, we've ironed out the bugs in the most-used
areas.  There might be some lurking in corner cases, and we do have
some time till the final release.

Looking at the current state, I am inclined to push the upstream
changes since we've been rigorously testing for regressions (and
everything looks settled now).

		Amit