[Bug 110238] Crashes when using MDEV passthrough on i915

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=110238

Christian Ehrhardt <christian.ehrhardt at canonical.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #4 from Christian Ehrhardt <christian.ehrhardt at canonical.com> ---
Hi,
thanks for your feedback.

I was experimenting more on the case actually and I found that sometimes it
just doesn not show up even after quite some time. But there was a way to
"force" the issue (which is on the host) from the guest.
To do so install opencl bits and try to use it, that would be:
 $ sudo apt install ocl-icd-libopencl1
 $ sudo apt install opencl-headers
 $ sudo apt install clinfo
 $ sudo apt install beignet
And then run clinfo
 $ clinfo
So far this triggered the bug immediately in all my tests.


With that set up to ensure I can actively trigger it I tried the suggested
intel_iommu=igfx_off.

That works like a charm in my setup - thanks!
With intel_iommu=igfx_off I can even run accelerated opencl load in the guest
on the mdev.

But since [1] states about that "If this fixes anything, please ensure you file
a bug reporting the problem." I think I might need to file a bug in a different
place - maybe for iommu itself then.

Thanks - we can close this bug and I'll look for a place to file that iommu
bug.

[1]: https://www.kernel.org/doc/Documentation/Intel-IOMMU.txt

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20190410/dfa10030/attachment-0001.html>