Re: [Qemu-devel] [PATCH 0/3] spapr: fix backward migration from POWER9 to POWER8 hosts

[Greg Kurz]

On Fri, 4 May 2018 16:37:19 +1000
David Gibson <address@hidden> wrote:

> On Fri, May 04, 2018 at 07:58:21AM +0200, Greg Kurz wrote:
> > On Fri, 4 May 2018 10:11:02 +1000
> > David Gibson <address@hidden> wrote:
> >   
> > > On Thu, May 03, 2018 at 11:16:10PM +0200, Greg Kurz wrote:  
> > > > Hi,
> > > > 
> > > > It is expected to be able to migrate a guest started with
> > > > 
> > > >      -machine max-cpu-compat=power8
> > > > 
> > > > from a POWER9 host to a POWER8 host. It works with recent QEMU versions,
> > > > but it is badly broken if the destination runs QEMU 2.7 or older.
> > > > 
> > > > This can cause problems in cloud environments that still have systems 
> > > > with
> > > > older QEMU versions, eg, hosts running ubuntu LTS 16.04.4 (QEMU 2.5) 
> > > > which
> > > > are likely to stay around until admins could transition to some newer 
> > > > OS.
> > > > 
> > > > This series was lightly tested, but the patches are simple enough, so 
> > > > I'm
> > > > confident they shouldn't break anything :)
> > > > 
> > > > Please review as I'd like these to go to QEMU 2.11.2 as well.    
> > > 
> > > Applied to ppc-for-2.13.  As you say, these should probably go to the
> > > 2.12 and 2.11 stable trees too.
> > >   
> > 
> > Cc'ing qemu-stable then  
> 
> Thanks.  I'm about to go on leave, so I won't be around to shepherd
> these into the stable trees any time soon.
> 

No problem. I'll take care of that with Mike.

Have a good *disconnected as much as possible* holiday ! :)

Cheers,

--
Greg

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