[vfio-users] Blank screen on Intel host graphics

[Wim de With]

Hello,

When I boot my PC, I see systemd starting on the monitor connected to my
NVIDIA GTX 970, and it freezes after printing "starting version 228". The
monitor connected to my Intel iGPU stays blank.

I'm using Arch Linux, and my mkinitcpio.conf contains this line:

	MODULES="vfio vfio_iommu_type1 vfio_pci vfio_virqfd"

According to the Arch Wiki, the base hook in the same file should load the
modules specified in MODULES early in the boot process. I have a file in
/etc/modprobe.d with the following lines:

	options vfio-pci ids=10de:13c2,10de:0fbb
	options vfio-pci disable_vga=1

Since I have no output on my monitors,  I used SSH to verify if vfio
successfully claimed the GTX 970, and lspci -k gives me this:

	01:00.0 VGA compatible controller: NVIDIA Corporation GM204 [GeForce GTX 970] (rev a1)
		Subsystem: Micro-Star International Co., Ltd. [MSI] Device 3160
		Kernel driver in use: vfio-pci
		Kernel modules: nouveau
	01:00.1 Audio device: NVIDIA Corporation GM204 High Definition Audio Controller (rev a1)
		Subsystem: Micro-Star International Co., Ltd. [MSI] Device 3160
		Kernel driver in use: vfio-pci
		Kernel modules: snd_hda_intel

so that should be correct.

I use only UEFI on my host, and I am planning to use only UEFI in my VM, so I
disabled vga in vfio. Am I correct to assume I don't need the i915 VGA arbiter
patch?

The only lines related to vfio in dmesg are:

	[   0.312470] VFIO - User Level meta-driver version: 0.3
	[   0.328097] vfio_pci: add [10de:13c2[ffff:ffff]] class 0x000000/00000000
	[   0.341412] vfio_pci: add [10de:0fbb[ffff:ffff]] class 0x000000/00000000

These are the lines that contain i915:

	[    1.500836] snd_hda_intel 0000:00:03.0: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
	[    1.500839] [drm] Initialized i915 1.6.0 20150522 for 0000:00:02.0 on minor 0
	[    1.538600] i915 0000:00:02.0: fb1: inteldrmfb frame buffer device
	[    1.538601] i915 0000:00:02.0: registered panic notifier

I also see some weird pixels in the top left corner of the monitor connected
to the Intel iGPU.

My hardware specifications are:

	Intel Core i5 4690K
	ASUS Z97-P
	NVIDIA GTX 970

Am I doing something wrong? Or is this simply a bug?

Wim