Re: Xen 4.4 development update: Is PVH a blocker?

From: Mukesh Rathor <mukesh.rathor@oracle.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>,
	xen-devel <xen-devel@lists.xenproject.org>,
	Tim Deegan <tim@xen.org>
Subject: Re: Xen 4.4 development update: Is PVH a blocker?
Date: Mon, 16 Dec 2013 15:45:58 -0800	[thread overview]
Message-ID: <20131216154558.5c9f8900@mantra.us.oracle.com> (raw)
In-Reply-To: <52AECC1B020000780010D80B@nat28.tlf.novell.com>

On Mon, 16 Dec 2013 08:47:07 +0000
"Jan Beulich" <JBeulich@suse.com> wrote:

> >>> On 13.12.13 at 20:21, George Dunlap <George.Dunlap@eu.citrix.com>
> >>> wrote:
> > This information will be mirrored on the Xen 4.4 Roadmap wiki page:
> >  http://wiki.xen.org/wiki/Xen_Roadmap/4.4 
> > 
> > Our timeline had us start the code freeze last Friday.  However, we
> > have not released an RC0 because we have been waiting for PVH dom0
> > support.  Adding bug fixes during RCs makes sense, but RC0 should
> > contain all of the functionality we expect to be in the final
> > release.
> > 
> > PVH dom0 support is making progress, however it's not that clear
> > when it will actually be ready to be checked in.  The current
> > discussion is about refcounting the new p2m type, which is a tricky
> > and delicate operation (though luckily one which should be limited
> > to domains which use that type -- at the moment, exclusively PVH
> > dom0s).
> > 
> > If we continue to wait, it is likely that the release will slip.
> > The question
> > then is, how long should we continue to wait before we cut our
> > losses and say we'll wait for PVH dom0 until 4.5?
> 
> Even if likely unpopular, given the condition the one critical patch
> is in I'd favor not waiting any longer at all, deferring the feature
> to 4.5 and cutting RC1 e.g. based on what got pushed over the
> weekend.

Aaah, we are so close, it looks like other than patch 6, all others
are ok. The patch #6 had 3 comments from Tim:

   - switch order in write_ept_entry() : Done.
   - Add check in Non-ept code: done.
   - Release of refcnt in case of p2m teardown: Since this only applies
     to control domain being destroyed, I don't think it's that critical
     for 4.4, so submitting a separate patch for it. That should make the 
     series eligible for 4.4 assuming Tim OK's the above two changes.
     Tim kindly take a look.

Having it in 4.4 would be nice as it would all the community users and
inhouse QA to test it all once, domU and dom0. It would also allow
my work and others to then focus on all the follow on PVH work like:
32bit, performance, amd port, hotplugs, etc... 

So, I hope you'll reconsider.

thanks
mukesh