[ovirt-users] Is it possible to disable qxl video?

[Arman Khalatyan]

Yes I have a BusID inside the xorg.conf.
I just tested with virt-manager and indeed it is not a ovirt failure.
It is something to do with qemu-kvm + nvidia.
I found here:https://wiki.debian.org/VGAPassthrough  that nvidia disables
device when it is running on qemu-kvm is it still the case? to overcome
that one need to set:

-cpu host,kvm=off

in the command line of qemu.

I was trying to convert virsh commands to qemu native, but it fails on
Centos 7 :(
virsh dumpxml > render.xml
virsh  domxml-to-native qemu-argv render.xml
error: internal error: invalid PCI passthrough type 'default'



***********************************************************

 Dr. Arman Khalatyan  eScience -SuperComputing
 Leibniz-Institut für Astrophysik Potsdam (AIP)
 An der Sternwarte 16, 14482 Potsdam, Germany

***********************************************************

On Mon, Jul 11, 2016 at 11:55 AM, Martin Polednik <mpolednik at redhat.com>
wrote:

> On 11/07/16 09:46 +0000, Karli Sjöberg wrote:
>
>>
>> Den 11 jul 2016 11:37 fm skrev Arman Khalatyan <arm2arm at gmail.com>:
>>
>>>
>>> I just testing several GPUs with pci-passthrough: GTX630, Tesla 2050 and
>>> FX5800.
>>> None of them I got running with opengl/direct rendering inside the
>>> virtual machine.
>>> I was thinking something to do with qxl driver, but after blacklisting
>>> it in the VMs kernel nothing was changed.
>>> The VMs Xorg claiming always no display found even if I configure it
>>> with headless option: nvidia-xconfig -a --use-display-device=None
>>> --virtual=1280x1024
>>> But with nvidia-smi I can see the GPU status, and I can run all cuda
>>> tests where opengl/X11 is not involved.
>>> My test system is CentOS 7 with ovirt 4.
>>> BTW If I clone VM which was not running, to real host on bare metal,
>>> everything is running as expecting.
>>>
>>
>> Don't remember If this was mentioned but have you tried doing the same
>> thing but with virt-manager on a standalone host, just to rule out oVirt
>> from the equation?
>>
>
> Also, the xorg must be setup to use the VFIO GPU. There is BusID
> option in device section that must point to the guest address of the
> GPU. I'm not sure if you've done that (and I'm quite sure it's missing
> on the wiki, noted).
>
> [in the guest]
> $ lspci | grep VGA
> 03:00.0 VGA compatible controller: NVIDIA Corporation GM107GL [Quadro
> K2200] (rev a2)
>
> and  using the address, add device section to /etc/X11/xorg.conf
>
> Section "Device"
>    Identifier     "Device0"
>    Driver         "nvidia"
>    VendorName     "NVIDIA Corporation"
>    BusID          "PCI:3:0:0"
> EndSection
>
> That should allow xorg to use the assigned GPU.
>
> mpolednik
>
>
> /K
>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> ***********************************************************
>>>
>>>  Dr. Arman Khalatyan  eScience -SuperComputing
>>>  Leibniz-Institut für Astrophysik Potsdam (AIP)
>>>  An der Sternwarte 16, 14482 Potsdam, Germany
>>>
>>> ***********************************************************
>>>
>>> On Mon, Jul 11, 2016 at 9:06 AM, Martin Polednik <mpolednik at redhat.com>
>>> wrote:
>>>
>>>>
>>>> On 08/07/16 11:29 +0200, Michal Skrivanek wrote:
>>>>
>>>>>
>>>>>
>>>>> On 06 Jul 2016, at 14:06, Francesco Romani <fromani at redhat.com> wrote:
>>>>>>
>>>>>>
>>>>>> From: "Arman Khalatyan" <arm2arm at gmail.com>
>>>>>> To: "users" <users at ovirt.org>
>>>>>> Sent: Monday, July 4, 2016 11:52:24 AM
>>>>>> Subject: [ovirt-users] Is it possible to disable qxl video?
>>>>>>
>>>>>>
>>>>>> Hi,
>>>>>> I am doing PCI Passthrough for GPUs.
>>>>>> Is it possible somehow to disable/remove default video qxl?
>>>>>> thanks,
>>>>>> Arman,.
>>>>>> Hi,
>>>>>>
>>>>>> The 4.0 Vdsm allows you to run a headless VM, meaning a VM without
>>>>>> graphic device/frontend.
>>>>>> Not sure Engine allows you that however.
>>>>>>
>>>>>
>>>>>
>>>>> no it doesn’t
>>>>>
>>>>
>>>>
>>>> Even if engine allowed that, it may not be the correct solution.
>>>>
>>>> Running headless with PCI passthrough is considered primary VGA
>>>> passthrough[1]. Using primary VGA passthrough without OVMF could cause
>>>> (will cause) quite a bit of headaches.
>>>>
>>>> If you really want to try that, I assume using before_vm_start hook to
>>>> remove the video device should be enough.
>>>>
>>>> [1] http://wiki.xenproject.org/wiki/Xen_VGA_Passthrough - it's
>>>> possible to read about primary and secondary passthrough between the
>>>> lines
>>>>
>>>> However, if QXL is the problem (why is that so?) then you can switch to
>>>>> VGA(or CIRRUS if this is still 3.6)
>>>>>
>>>>> I'm afraid you will need to write a Vdsm hook.
>>>>>>
>>>>>> There could be simpler solutions depending on the Engine
>>>>>>
>>>>>> Bests,
>>>>>>
>>>>>> --
>>>>>> Francesco Romani
>>>>>> RedHat Engineering Virtualization R & D
>>>>>> Phone: 8261328
>>>>>> IRC: fromani
>>>>>> _______________________________________________
>>>>>> Users mailing list
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>>>>>> http://lists.ovirt.org/mailman/listinfo/users>
>>>>>>
>>>>>
>>>>
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>>>>
>>>>
>>>
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