Re: [PATCH] vfio: Enable VFIO device for powerpc

From: Paul Mackerras
Date: Wed Aug 26 2015 - 14:55:04 EST

On Wed, Aug 26, 2015 at 11:34:26AM +0200, Alexander Graf wrote:
> On 13.08.15 03:15, David Gibson wrote:
> > ec53500f "kvm: Add VFIO device" added a special KVM pseudo-device which is
> > used to handle any necessary interactions between KVM and VFIO.
> >
> > Currently that device is built on x86 and ARM, but not powerpc, although
> > powerpc does support both KVM and VFIO. This makes things awkward in
> > userspace
> >
> > Currently qemu prints an alarming error message if you attempt to use VFIO
> > and it can't initialize the KVM VFIO device. We don't want to remove the
> > warning, because lack of the KVM VFIO device could mean coherency problems
> > on x86. On powerpc, however, the error is harmless but looks disturbing,
> > and a test based on host architecture in qemu would be ugly, and break if
> > we do need the KVM VFIO device for something important in future.
> >
> > There's nothing preventing the KVM VFIO device from being built for
> > powerpc, so this patch turns it on. It won't actually do anything, since
> > we don't define any of the arch_*() hooks, but it will make qemu happy and
> > we can extend it in future if we need to.
> >
> > Signed-off-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
> Paul is going to take care of the kvm-ppc tree for 4.3. Also, ppc kvm
> patches should get CC on the kvm-ppc@vger mailing list ;).
> Paul, could you please pick this one up?

Sure, I'll do that once I get home (end of this week).

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