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From: Paolo Bonzini <pbonzini@redhat.com>
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Date: Thu, 19 Nov 2015 16:49:46 +0100
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Subject: Re: [Qemu-devel] [Intel-gfx] [Announcement] 2015-Q3 release of
 XenGT - a Mediated Graphics Passthrough Solution from Intel
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To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Jike Song <jike.song@intel.com>
Cc: "igvt-g@ml01.01.org" <igvt-g@ml01.01.org>, "Tian,
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On 19/11/2015 16:32, Stefano Stabellini wrote:
> > In addition to Kevin's replies, I have a high-level question: can VFIO
> > be used by QEMU for both KVM and Xen?
> 
> No. VFIO cannot be used with Xen today. When running on Xen, the IOMMU
> is owned by Xen.

I don't think QEMU command line compatibility between KVM and Xen should
be a design goal for GVT-g.

Nevertheless, it shouldn't be a problem to use a "virtual" VFIO (which
doesn't need the IOMMU, because it uses the MMU in the physical GPU)
even under Xen.

Paolo