Subject: Re: [PATCH] vfio: Enable VFIO device for powerpc
To: David Gibson <david@gibson.dropbear.id.au>, alex.williamson@redhat.com,
        pbonzini@redhat.com
References: <1439428546-13416-1-git-send-email-david@gibson.dropbear.id.au>
Cc: paulus@samba.org, 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, Paul Mackerras <paulus@samba.org>,
        kvm-ppc <kvm-ppc@vger.kernel.org>
From: Alexander Graf <agraf@suse.de>
Message-ID: <55DD8822.4060409@suse.de>
Date: Wed, 26 Aug 2015 11:34:26 +0200
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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?


Thanks!

Alex
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