Re: [PATCH] kvm/ppc/booke64: fix build breakage from Altivec, and disable e6500

[Scott Wood <scottwood@freescale.com>]

On 05/10/2013 09:11:24 AM, Caraman Mihai Claudiu-B02008 wrote:
> > -----Original Message-----
> > From: Alexander Graf [mailto:agraf@suse.de]
> > Sent: Friday, May 10, 2013 4:16 PM
> > To: Caraman Mihai Claudiu-B02008
> > Cc: Wood Scott-B07421; kvm-ppc@vger.kernel.org; kvm@vger.kernel.org
> > Subject: Re: [PATCH] kvm/ppc/booke64: fix build breakage from  
> Altivec,
> > and disable e6500
> >
> >
> > On 10.05.2013, at 11:40, Caraman Mihai Claudiu-B02008 wrote:
> >
> > >> -----Original Message-----
> > >> From: Wood Scott-B07421
> > >> Sent: Friday, May 10, 2013 6:15 AM
> > >> To: Alexander Graf
> > >> Cc: kvm-ppc@vger.kernel.org; kvm@vger.kernel.org; Wood  
> Scott-B07421;
> > >> Caraman Mihai Claudiu-B02008
> > >> Subject: [PATCH] kvm/ppc/booke64: fix build breakage from  
> Altivec, and
> > >> disable e6500
> > >>
> > >> BookE altivec support brought two new exceptions, but KVM was not
> > >> updated, so the build broke for all 64-bit booke with KVM  
> enabled.
> > >
> > > We couldn't do that in KVM before having
> > BOOKE_INTERRUPT_ALTIVEC_UNAVAIL/
> > > BOOKE_INTERRUPT_ALTIVEC_ASSIST. As Tiejun noticed earlier we  
> should
> > have
> > > done this in Kumar's tree but we missed that chance. We will face
> > similar
> > > issues every time an exception handler will be added.
> >
> > How hard would it be to add? I suppose it's broken in 3.10, so we  
> need
> > something quick before it gets released?
> 
> Not so hard. Yes. I was surprised by this patch given the fact that  
> we have
> planned to send altivec support upstream this days and that we  
> already have
> a similar patch from Tiejun on our list.

I didn't see Tiejun's patch...  My goal was just to fix the build break  
without exposing problems, and to encourage a patch to fix it properly  
to happen sooner rather than later.  With Tiejun's patch, which is  
similar to mine except that it doesn't disable e6500 support, a user  
could BUG() the kernel by forcing an Altivec exception in a guest.  I  
didn't want to go further down the road of adding reflectors for those  
exceptions, which could make it look like the problem was dealt with  
even though it's still not done.

-Scott