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: Wed, 17 Feb 2016 07:36:59 -0800
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Cc: "Tian, Kevin" <kevin.tian@intel.com>,
	"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>,
	Paolo Bonzini <pbonzini@redhat.com>,
	"Lv, Zhiyuan" <zhiyuan.lv@intel.com>
To: Gerd Hoffmann <kraxel@redhat.com>
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On Wed, Feb 17, 2016 at 02:08:18PM +0100, Gerd Hoffmann wrote:
>   Hi,
> 
> > For example, how to locate the path of a given VM?
> 
> You go ask libvirt, the domain xml will have the info.
> 
> > 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.
> 
> No.  qemu simply uses the path it get passed from libvirt.  libvirt
> simply uses whatever is stored in the domain xml.
> 
> i.e. you'll have a config like this:
> 
> <domain type='kvm'> 
>   <name>rhel7-vfio</name>
>   <uuid>0990b05d-4fbd-49bf-88e4-e87974c64fba</uuid>
>   [ ... ]
>   <devices>
>     [ ... ]
>     <hostdev mode='subsystem' type='pci' managed='yes'>
>       <source>
>         <address sysfs='/sys/devices/virtual/vgpu/${name}'/>
>       </source>
>       <address type='pci' domain='0x0000'
>                bus='0x00' slot='0x04' function='0x0'/>
>     </hostdev>
> 
> > 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,
> 
> Yes.  But the above sounds like you want to use UUIDs to *link* two
> objects, by assigning the same uuid to both vm and vgpu.  This is *not*
> how uuids should be used.  Each object should have its own uuid.
> 
> You can use uuids to name the vgpus if you want of course.  But the vgpu
> uuid will will have no relationship whatsoever to the vm uuid then.
> 

Agree. I should made it clear that it should be a separate object.

Thanks,
Neo

> cheers,
>   Gerd
> 

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Date: Wed, 17 Feb 2016 07:36:59 -0800
From: Neo Jia <cjia@nvidia.com>
Message-ID: <20160217153659.GC11166@nvidia.com>
References: <20160216084855.GA7717@nvidia.com>
	<AADFC41AFE54684AB9EE6CBC0274A5D15F7B51AE@SHSMSX101.ccr.corp.intel.com>
	<20160217041743.GA7903@nvidia.com>
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	<20160217053742.GA8839@nvidia.com>
	<AADFC41AFE54684AB9EE6CBC0274A5D15F7B5757@SHSMSX101.ccr.corp.intel.com>
	<20160217072610.GA9416@nvidia.com>
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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: Gerd Hoffmann <kraxel@redhat.com>
Cc: "Ruan, Shuai" <shuai.ruan@intel.com>, "Tian, Kevin" <kevin.tian@intel.com>, Alex Williamson <alex.williamson@redhat.com>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, qemu-devel <qemu-devel@nongnu.org>, "Song, Jike" <jike.song@intel.com>, Kirti Wankhede <kwankhede@nvidia.com>, "Lv,
	Zhiyuan" <zhiyuan.lv@intel.com>, Paolo Bonzini <pbonzini@redhat.com>

On Wed, Feb 17, 2016 at 02:08:18PM +0100, Gerd Hoffmann wrote:
>   Hi,
> 
> > For example, how to locate the path of a given VM?
> 
> You go ask libvirt, the domain xml will have the info.
> 
> > 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.
> 
> No.  qemu simply uses the path it get passed from libvirt.  libvirt
> simply uses whatever is stored in the domain xml.
> 
> i.e. you'll have a config like this:
> 
> <domain type='kvm'> 
>   <name>rhel7-vfio</name>
>   <uuid>0990b05d-4fbd-49bf-88e4-e87974c64fba</uuid>
>   [ ... ]
>   <devices>
>     [ ... ]
>     <hostdev mode='subsystem' type='pci' managed='yes'>
>       <source>
>         <address sysfs='/sys/devices/virtual/vgpu/${name}'/>
>       </source>
>       <address type='pci' domain='0x0000'
>                bus='0x00' slot='0x04' function='0x0'/>
>     </hostdev>
> 
> > 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,
> 
> Yes.  But the above sounds like you want to use UUIDs to *link* two
> objects, by assigning the same uuid to both vm and vgpu.  This is *not*
> how uuids should be used.  Each object should have its own uuid.
> 
> You can use uuids to name the vgpus if you want of course.  But the vgpu
> uuid will will have no relationship whatsoever to the vm uuid then.
> 

Agree. I should made it clear that it should be a separate object.

Thanks,
Neo

> cheers,
>   Gerd
>