[vfio-users] VFIO + UEFI virt VS i915 arbiter patch and a few more questions

[Alex Williamson]

On Tue, Jan 5, 2016 at 3:57 PM, Milos Kaurin <milos.kaurin at gmail.com> wrote:

> Hello,
>
> Firstly, a big thanks to everyone contributing to VFIO and other
> virtualization technologies that are making my GPU pass-through dream
> come true.
>
> I currently have this:
>
> CPU: Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
>
> ==================================
> -[0000:00]-+-00.0  Intel Corporation 4th Gen Core Processor DRAM Controller
>            +-01.0-[01]--+-00.0  NVIDIA Corporation GK104 [GeForce GTX 770]
>            |            \-00.1  NVIDIA Corporation GK104 HDMI Audio
> Controller
>            +-02.0  Intel Corporation Xeon E3-1200 v3/4th Gen Core
> Processor Integrated Graphics Controller
>            +-03.0  Intel Corporation Xeon E3-1200 v3/4th Gen Core
> Processor HD Audio Controller
>            +-14.0  Intel Corporation 8 Series/C220 Series Chipset
> Family USB xHCI
>            +-16.0  Intel Corporation 8 Series/C220 Series Chipset
> Family MEI Controller #1
>            +-19.0  Intel Corporation Ethernet Connection I217-LM
>            +-1b.0  Intel Corporation 8 Series/C220 Series Chipset High
> Definition Audio Controller
>            +-1c.0-[02]--
>            +-1c.1-[03-04]----00.0-[04]--
>            +-1f.0  Intel Corporation Q87 Express LPC Controller
>            +-1f.2  Intel Corporation 8 Series/C220 Series Chipset
> Family 6-port SATA Controller 1 [AHCI mode]
>            \-1f.3  Intel Corporation 8 Series/C220 Series Chipset
> Family SMBus Controller
> ====================================================================
>
> To avoid pasting iommu groups, every device is now in its own separate
> group due to ACS patch.
>

You don't need the ACS patch


> Running on FC23 with a custom Kernel:
> Linux gammalinux 4.2.8-300.milos.fc23.x86_64 #1 SMP Sun Jan 3 23:38:23
> GMT 2016 x86_64 x86_64 x86_64 GNU/Linux
>
> Custom kernel:
> I have applied the ACS patch because my CPU root bridge (IIRC) was
> grouped with the NVIDIA GPU/audio. I have also applied the i915
> arbiter patch.
>
> My virt is UEFI based (virt-manager instructions from the blog),
> Windows 10 Guest, no audio (yet)
>

You don't need the i915 patch


> >From what I understood from Alex's blog and some other material of his
> I found online, if you want to use an integrated Intel GPU for the
> host, you have to apply the arbiter patch to avoid display corruption
> etc because i915 driver is a liar.
>
> My first question is: Is this only true for BIOS-based guests or does
> it also go for UEFI based guests?
>

Only using BIOS, x-vga=on.  You have a UEFI guest, use the stock Fedora
kernel.


> I'm asking because even though I applied the i915 arbiter patch, I
> disabled the entry in modprobe.d to test and see what will happen.
> Nothing happens on guest/host (Ran 3dmark extreme benchmarks multiple
> times now).
>
> Second question:
> I'm thinking of letting the guest have the "USB xHCI" controller(14.0
> from the lspci above). Due to some warnings from Alex on ACS being
> potentially dangerous, I wanted to ask you guys whether it's safe to
> use vfio-pci on that device.
>

You don't need the ACS patch to assign that device either.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/vfio-users/attachments/20160105/3c15df91/attachment.htm>