Re: New kvm-related qemu patch queue

[Gleb Natapov <gleb@redhat.com>]

On Sun, Jan 10, 2010 at 04:30:44PM +0200, Avi Kivity wrote:
> On 01/10/2010 04:28 PM, Gleb Natapov wrote:
> >On Sun, Jan 10, 2010 at 02:02:27PM +0200, Avi Kivity wrote:
> >>In order to improve qemu.git kvm integration quality wrt
> >>performance, features, and reliability Marcelo and I will begin to
> >>maintain a patch queue based on qemu.git containing kvm-related
> >>patches.  We will review and apply patches to this queue, test them
> >>using the same test suite that is used for qemu-kvm.git, and
> >>regularly submit them for inclusion in qemu.git, mimicking the
> >>relationship between kvm.git and Linus' linux-2.6.git.
> >>
> >>One of the problems of qemu.git kvm support is that it is a clean
> >>reimplementation, and thus some of the nuances that were carefully
> >>ironed out in qemu-kvm.git are lost.  To that end, we would like to
> >>change the process of adding features as follows:
> >>
> >>  - first, the feature in qemu-kvm.git master is morphed to a form
> >>suitable for merging into qemu.git
> >>  - when that has been accomplished, the feature is broken into
> >>patches and merged into the patch queue
> >>
> >If there is the same feature in qemu-kvm.git and qemu.git whom is morphed to
> >whom and who is merged where? I am confused. We have much of duplicated
> >code between qemu-kvm.git and qemu.git it is often almost, but not exactly the
> >same. Is it really productive to set rules who should be morphed and how
> >at this point?
> 
> If the feature is already in both, then morph qemu-kvm.git into what
> is already in qemu.git.  Hopefully anything missing in qemu.git will
> be discovered while making the changes.
> 
What about bugs that are present only in qemu.git? Like this:
http://patchwork.ozlabs.org/patch/42298/. Should it go through
qemu-kvm.git/uq/master?

What about this one: http://patchwork.ozlabs.org/patch/42447/ should it
be postponed untill qemu.git and qemu-kvm.git converge on using the same
cpuid infrastructure, or add similar functionality to qemu-kvm to,
or add new cpu flags to qemu-kvm only and when cpuid code converge
qemu.git will have it too?

> >>In order to get a kvm feature into qemu.git, please observe the
> >>following process:
> >>
> >>- post a patch series against qemu-kvm.git/master that implements
> >>the feature, or changes an existing feature to use qemu.git
> >>infrastructure
> >It was other way around till last week. Why change?
> 
> There were a lot of regressions.
> 
Yeah :(

--
			Gleb.