[SOLVED]Display manager not starting after configuring gpu passthrough

bestbtw · 2022-11-04 02:53:23

I have a PC with an nvidia GPU and a CPU with integrated graphics and i wanted to configure arch so i could use the gpu for VMs and the igpu for linux.
Everything goes as intended until i reboot my PC to actually try if the passthrough for the GPU works, and it does.
But it seems like the display manager won't start at all even if i try to manually do it from tty.
Error logs didn't help much, it's just the display server crashing.
After a bit of searching it seems that its about an option on the BIOS for selecting wich GPU to give "priority" to for display output, but mine only gives the option to enable the igpu or not.
Is there a way of still giving my igpu priority for linux?

Last edited by bestbtw (2022-11-05 16:24:59)

seth · 2022-11-04 07:22:12

Post your xorg log and move /etc/X11/xorg.conf away.

bestbtw · 2022-11-04 15:06:17

Thanks for the quick response!
Here is the xorg log copied from /var/log/: https://pastebin.com/Gib5rS9Y

Also what do you mean by moving /etc/X11/xorg.conf away?
I checked for that file but i don't have it...

seth · 2022-11-04 15:26:57

Also what do you mean by moving /etc/X11/xorg.conf away?

Mere speculation on the reason, but it's not.

But the server tries to run on the non-existing cart1.
You do have xf86-video-nouveau installed, see whether removing that is sufficient.

bestbtw · 2022-11-04 15:52:59

Just did remove that exact package but still no luck.
Here are the logs: https://pastebin.com/cxSJjdVW
By taking a quick look at it it seems that it doesn't load the nouveau driver anymore but at the end it still gives the same error.

seth · 2022-11-04 15:58:44

Please post teh system journal

sudo journalctl -b | curl -F 'file=@-' 0x0.st

bestbtw · 2022-11-04 16:01:17

http://0x0.st/ogE7.txt

seth · 2022-11-04 16:03:56

That boot doesn't pass through the nvidia chip, try eg.

sudo journalctl -b -1 | curl -F 'file=@-' 0x0.st

for the previous boot.

bestbtw · 2022-11-04 16:09:59

My bad, here: http://0x0.st/og6P.txt

seth · 2022-11-04 16:20:36

It'S the exact same boot as you posted before:

Nov 04 16:46:47 synergy kernel: Linux version 6.0.6-arch1-1 (linux@archlinux) (gcc (GCC) 12.2.0, GNU ld (GNU Binutils) 2.39.0) #1 SMP PREEMPT_DYNAMIC Sat, 29 Oct 2022 14:08:39 +0000
Nov 04 16:46:47 synergy kernel: Command line: BOOT_IMAGE=/vmlinuz-linux root=UUID=43932588-5c5f-4644-b113-11de31df8475 rw rootfstype=ext4 loglevel=3 intel_iommu=on iommu=pt

bestbtw · 2022-11-04 16:27:29

That's strange, the urls are clearly different.
I'm sure i did the second one after rebooting with the vfio bootloader parameters set.
I literally did that from tty because lightdm crashes. I'll try again and repost the system journal if it's different.

seth · 2022-11-04 16:37:47

If you rebooted w/ vfio enabled and then issued "sudo journalctl -b -1 | curl -F 'file=@-' 0x0.st" you posted the journal of the previous boot, ie. the one w/o vfio.

bestbtw · 2022-11-04 16:37:52

Still the same output, I don't know why...
But after rebooting without the parameters on grub so that i can actually use the system i noticed that the login manager showed on the monitor attached to the igpu. This never happened.
Here is still the link: http://0x0.st/og6E.txt

Last edited by bestbtw (2022-11-04 16:39:42)

bestbtw · 2022-11-04 16:47:12

Sorry, didn't know how to use journalctl in the first place. Still learning...
http://0x0.st/ogIK.txt

seth · 2022-11-04 20:18:57

vfio takes cotrol of the device and nouveau isn't loaded.
Does this also happen if you only boot the mutli-user.target (2nd link below), login on the console, wait some seconds and start the lightdm service (or graphical.target) from there?

If nothing else helps, you could also just blacklist nouveau.
https://wiki.archlinux.org/title/Kernel … acklisting

bestbtw · 2022-11-05 08:52:59

Same happens trying both things.
If i try to startx or run light or start graphical.target with the default set to multi-user.target everything behaves the same.
Blacklisting nouveau didn't help.
Really if i had that option on the bios i was talking about earlier everything would be easier...
Also as i was trying to reboot with nouveau still blacklisted and with vfio parameters removed xorg still crashes.

Last edited by bestbtw (2022-11-05 08:56:56)

seth · 2022-11-05 09:46:15

In doubt we'll force-configure x11 t use the intel chip, this just should(tm) not benecessary.

ls -R /{etc,usr/share}/X11/xorg.conf*

bestbtw · 2022-11-05 10:01:27

That command still doesn't show any "xorg.conf" file.
Should i manually create it? If so how would i set xorg to force use the intel igpu?
Here is the list of .conf files: https://pastebin.com/yTL0288V

Last edited by bestbtw (2022-11-05 10:02:16)

seth · 2022-11-05 10:13:12

Why are there 10-amdgpu.conf and 10-radeon.conf? You don'thave such GPUs?

Having a

Section "OutputClass"
    Identifier "intel"
    MatchDriver "i915"
    Driver "modesetting"
EndSection

config should already prefer that GPU

Otherwise https://wiki.archlinux.org/title/PRIME#Configuration may serve as a pattern...

bestbtw · 2022-11-05 11:11:01

Fixed!
I've followed the linked you posted and created the xorg.conf file and configured the intel with its corresponding screen and busid.
I really cannot thank you enough for all of the help you gave me dude, this problem has been driving me crazy for more than a week!

Last edited by bestbtw (2022-11-05 11:12:47)

seth · 2022-11-05 12:19:25

Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

However this is more a workaround than a fix. The vfio module should™ grab the device (does) and X11 should™ not consider it and it also should™ not do so preferably.
Something™ makes 1@0:0:0 the default device but I neither see what nor understand why.
You might want to keep an eye on this, my best guess is the presence of xf86-video-ati and xf86-video-amdgpu - but that guess is based on exactly nothing

Arch Linux

#1 2022-11-04 02:53:23

[SOLVED]Display manager not starting after configuring gpu passthrough

#2 2022-11-04 07:22:12

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#3 2022-11-04 15:06:17

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#4 2022-11-04 15:26:57

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#5 2022-11-04 15:52:59

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#6 2022-11-04 15:58:44

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#7 2022-11-04 16:01:17

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#8 2022-11-04 16:03:56

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#9 2022-11-04 16:09:59

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#10 2022-11-04 16:20:36

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#11 2022-11-04 16:27:29

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#12 2022-11-04 16:37:47

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#13 2022-11-04 16:37:52

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#14 2022-11-04 16:47:12

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#15 2022-11-04 20:18:57

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#16 2022-11-05 08:52:59

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#17 2022-11-05 09:46:15

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#18 2022-11-05 10:01:27

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#19 2022-11-05 10:13:12

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#20 2022-11-05 11:11:01

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

#21 2022-11-05 12:19:25

Re: [SOLVED]Display manager not starting after configuring gpu passthrough

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