[SOLVED] Changing which GPU xorg uses

Bladesy · 2015-09-26 00:02:55

Hello everyone, I'm struggling with getting my intel 4600 integrated graphics working for use with PCI passthrough.
I currently have 2 kernels, 2 monitors, and 2 GPUs. One of the kernels has my nvidia 660 disabled, so that I can use it in a virtual machine, but whenever I load it up, it seems to use the 660 alone but under a more generic driver. The problem with this is that I have 2 monitors, my small monitor's VGA being plugged into the integrated graphics, as is the big monitor under HDMI - but this monitor is also plugged into the 660 by DVI.
So basically, when I use the nvidia-disabled kernel, only the big monitor's DVI is used, and the HDMI and VGA are ignored completely. I believe that xorg is only using the 660, because it complained about nvidia drivers being absent before I installed the generic driver.
Is there a way I can get xorg to use the integrated graphics only (completely ignoring the DVI of the 660), so that I get the HDMI and VGA output, and thus my 2 monitors?
I'm really sorry if I've worded this confusingly, but I don't think I can explain it better.

Last edited by Bladesy (2015-09-26 21:15:46)

Lone_Wolf · 2015-09-26 11:55:57

I suggest to focus first on the host kernel, and making sure the card you want to passthrough to the guest is not used by the host.

Which videocard you want to use for the host and which one should be used one for the guest ?

What brand/model is your motherboard ?
what processor are you using ?

-----------------------
Sidenote :
The way you describe your monitor setup will let X see THREE monitors (atleast if no PCI passthrough is used) :
vga on intel
hdmi on intel
dvi on nvidia card

Bladesy · 2015-09-26 12:11:11

Thanks for replying, I'm looking the intel 4600 to be used by the host, while the 660 is used only by the guest. My motherboard is an MSI z97, and the processor is an i5-4690k.
I'm using pci-stub at the minute so that the 660 is blacklisted from the kernel, but it seems that the generic video driver still grabs the 660, as I'm using the DVI right now.

Lone_Wolf · 2015-09-26 12:20:12

check in the bios/uefi firmware which card is configured to be the primary/default videocard, and change it to the integrated one if needed.

Bladesy · 2015-09-26 12:32:00

It worked - I'm now using VGA and HDMI for the arch linux host - but there's one small problem.
i3 seems to be mirroring the small monitor onto the big monitor.
The reason I say i3 is because my background manager nitrogen has the wallpaper fill the whole of the big monitor.
Should I take a screenshot?

Bladesy · 2015-09-26 21:15:22

Alright, I've got it all sorted now. To change the weird screen settings, I had to get xrandr and use arandr to move the screenspaces about - it turns out the HDMI and VGA were overlapping, which made it seem like they were on mirror mode, but made nitrogen still give me a full sized background.
I actually ran into another problem with the GPU passthrough, after blacklisting the 660's audio - even though I wasn't using it - which was solved by specifying the default audio device in ~/.asound.
Thanks for your help wolf, the boot gpu setting was the root of my problems.

Arch Linux

#1 2015-09-26 00:02:55

[SOLVED] Changing which GPU xorg uses

#2 2015-09-26 11:55:57

Re: [SOLVED] Changing which GPU xorg uses

#3 2015-09-26 12:11:11

Re: [SOLVED] Changing which GPU xorg uses

#4 2015-09-26 12:20:12

Re: [SOLVED] Changing which GPU xorg uses

#5 2015-09-26 12:32:00

Re: [SOLVED] Changing which GPU xorg uses

#6 2015-09-26 21:15:22

Re: [SOLVED] Changing which GPU xorg uses

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