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From: Gerd Hoffmann <kraxel@redhat.com>
Date: Tue, 02 Feb 2016 09:29:18 +0100
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Subject: Re: [Qemu-devel] [RFC PATCH v1 1/1] vGPU core driver : to provide
 common interface for vGPU.
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To: Neo Jia <cjia@nvidia.com>
Cc: "Ruan, Shuai" <shuai.ruan@intel.com>, "Song, Jike" <jike.song@intel.com>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, "Tian,
	Kevin" <kevin.tian@intel.com>, Kirti Wankhede <kwankhede@nvidia.com>, qemu-devel <qemu-devel@nongnu.org>, Alex Williamson <alex.williamson@redhat.com>, "Lv,
	Zhiyuan" <zhiyuan.lv@intel.com>, Paolo Bonzini <pbonzini@redhat.com>

On Di, 2016-02-02 at 00:13 -0800, Neo Jia wrote:
> On Tue, Feb 02, 2016 at 09:00:43AM +0100, Gerd Hoffmann wrote:
> >   Hi,
> >=20
> > > And for UUID, I remember Alex had a concern on using it in kernel.=
=20
> > > Honestly speaking I don't have a good idea here. In Xen side there is=
 a VM ID
> > > which can be easily used as the index. But for KVM, what would be the=
 best
> > > identifier to associate with a VM?
> >=20
> > The vgpu code doesn't need to associate the vgpu device with a vm in th=
e
> > first place.  You get all guest address space information from qemu, vi=
a
> > vfio iommu interface.
> >=20
> > When qemu does't use kvm (tcg mode), things should still work fine.
> > Using vfio-based vgpu devices with non-qemu apps (some kind of test
> > suite for example) should work fine too.
>=20
> Hi Gerd and Kevin,
>=20
> I thought Alex had agreed with the UUID as long as it is not tied with VM=
,
> probably it is just his comment gets lost in our previous long email thre=
ad.

As long as it isn't tied to a VM it is fine indeed.  We'll need names
for the devices, and using a uuid certainly is one option.  Could also
be a simple "vgpu${index}".  A more descriptive name such as
"nvidia-grid-${index}" or "igd-skl-${index}".  Or just a free-form
string where the driver can fill whatever it wants (including a uuid).

cheers,
  Gerd