From mboxrd@z Thu Jan  1 00:00:00 1970
From: Neo Jia <cjia@nvidia.com>
Subject: Re: [Qemu-devel] [RFC PATCH v1 1/1] vGPU core driver : to provide
 common interface for vGPU.
Date: Tue, 16 Feb 2016 23:54:48 -0800
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Cc: "Ruan, Shuai" <shuai.ruan@intel.com>,
	"Song, Jike" <jike.song@intel.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Kirti Wankhede <kwankhede@nvidia.com>,
	qemu-devel <qemu-devel@nongnu.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	Gerd Hoffmann <kraxel@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	"Lv, Zhiyuan" <zhiyuan.lv@intel.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
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On Wed, Feb 17, 2016 at 07:46:15AM +0000, Tian, Kevin wrote:
> > From: Neo Jia
> > Sent: Wednesday, February 17, 2016 3:26 PM
> > 
> > 
> 
> > 
> > If your most concern is having this kind of path doesn't provide enough
> > information of the virtual device, we can add more sysfs attributes within the
> > directory of /sys/devices/virtual/vgpu/$UUID-$vgpu_idx/ to reflect the
> > information you want.
> 
> Like Gerd said, you can have something like this:
> 
> -device vfio-pci,sysfsdev=/sys/devices/virtual/vgpu/vgpu_idx/UUID

Hi Kevin,

The vgpu_idx is not unique number at all.

For example, how to locate the path of a given VM? Whoever is going to configure
the qemu has to walk through *all* the current vgpu path to locate the UUID to
match the QEMU's VM UUID. This is not required if you have UUID as part of the
device path.

> 
> > 
> > Even with UUID, you don't need libvirt at all. you can get uuid by running
> > uuidgen command, I don't need libvirt to code up and test the RFC that I have
> > sent out early. :-)
> 
> although simple, it still creates unnecessary user space dependency for
> kernel resource management...

I think I has answered this, UUID is not a user space or kernel space
concept, it is just a generic way to represent object, it just make sure that
virtual gpu device directory can be uniquely addressed.

Thanks,
Neo

> 
> Thanks
> Kevin