Re: [PATCH v9 00/12] Add Mediated device support

From: Jike Song
Date: Mon Dec 05 2016 - 21:25:34 EST


On 12/06/2016 01:44 AM, Gerd Hoffmann wrote:
> Hi,
>
>> Just want to share that we have published a KVMGT implementation
>> based on this v9 patchset, to:
>>
>> https://github.com/01org/gvt-linux/tree/gvt-next-kvmgt
>>
>> It doesn't utilize common routines introduced by 05+ patches yet.
>> The complete intel vGPU device-model is contained.
>
> Tried to use this implementation. Used the
> topic/gvt-next-kvmgt-mdev-2016-11-18 branch which looked like the most
> recent one. Setup:
>

Hi Gerd,

We didn't catch up with updating the newest kvmgt code accordingly,
partly because we are preparing the 'final' version to be upstreamed.

Will update a topic/gvt-next-kvmgt-2016-12-06 today, sorry for the
inconvenience :)

> * Everything compiled as modules.
> * iommu turned off for the igd (intel_iommu=on,igfx_off).
> * Blacklisted i915 so dracut initrd doesn't load it
> (rd.driver.blacklist=i915)
> * tweaked module config so kvmgt is loaded before i915,
> also enable gvt:
>
> # cat /etc/modprobe.d/kraxel-gvt.conf
> options i915 enable_gvt=1
> softdep i915 pre: kvmgt
>
> Everything seems to load fine. Sysfs files are there, and I can create
> vgpus.
>

Yes, everything looks good so far.

> Trying to assign a vgpu this way:
>
> -device vfio-pci,sysfsdev=/sys/class/mdev_bus/0000:00:02.0/<uuid>
>
> fails though and gives this message in the kernel log:
>
> [ 402.560350] [drm:intel_vgpu_open [kvmgt]] *ERROR* gvt: KVM is
> required to use Intel vGPU
>
> Trying the same with a mtty sample device works and I can see the pci
> serial device in the guest.
>
> Any clues what is going wrong?

The getting kvm instance code is missing in that branch, will be
contained in the new one.

> Has this version any support for exporting the guest display as dma-buf,
> so qemu can show it? Or is this a headless vgpu?

No, this version doesn't have dma-buf support yet, we were using x11vnc
in guest to test it internally. I'll include you in the igvt-g-dev
mailing list for further discussion :)

--
Thanks,
Jike