Date: Wed, 26 Aug 2015 11:54:42 -0700
From: Paul Mackerras <paulus@ozlabs.org>
To: Alexander Graf <agraf@suse.de>
Cc: David Gibson <david@gibson.dropbear.id.au>, alex.williamson@redhat.com,
        pbonzini@redhat.com, aik@ozlabs.ru, mdroth@linux.vnet.ibm.com,
        benh@kernel.crashing.org, mpe@ellerman.id.au, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, kvm-ppc <kvm-ppc@vger.kernel.org>
Subject: Re: [PATCH] vfio: Enable VFIO device for powerpc
Message-ID: <20150826185442.GB2662@fergus.ozlabs.ibm.com>
References: <1439428546-13416-1-git-send-email-david@gibson.dropbear.id.au>
 <55DD8822.4060409@suse.de>
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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@gibson.dropbear.id.au>
> > Reviewed-by: Eric Auger <eric.auger@linaro.org>
> 
> 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).

Paul.
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