Arch Linux

hypothermic

Member

Registered: 2020-08-20

Posts: 6

X fails with "no screens found" error on boot

My goal is to start X on my secondary GPU (Nvidia GT 740) because my primary GPU (GTX 970) is isolated and managed by vfio-pci according to this.

However, Xorg fails with the error "no screens found" on bootup

Interesting parts of Xorg log:

[     6.891] (==) Using config directory: "/etc/X11/xorg.conf.d"
[     6.891] (==) No Layout section. Using the first Screen section.
[     6.891] (==) No screen section available. Using defaults.
[     6.891] (**) |-->Screen "Default Screen Section" (0)
[     6.891] (**) |   |-->Monitor "<default monitor>"
[     6.892] (==) No device specified for screen "Default Screen Section". Using the first device section listed.
[     6.892] (**) |   |-->Device "Device0"
[     6.891] (==) No monitor specified for screen "Default Screen Section". Using a default monitor configuration.
...
[    10.617] (EE) No devices detected
[    10.617] (EE) 
Fatal server error:
[    10.617] (EE) no screens found(EE)
[    10.617] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[    10.617] (EE) 
[    10.617] (EE) Server terminated with error (1). Closing log file.

Xorg config:

[root@archiso /]# cat /etc/X11/xorg.conf.d/secondary-gpu.conf
Section "Device"
        Identifier "Device0"
        Driver "nvidia"
        BusID "PCI:25:0:0"
EndSection

The devices:

[root@archiso /]# lspci -Dnn | grep -i -e vga
0000:25:00.0 VGA compatible controller [0300]: NVIDIA Corporation GK107 [GeForce GT 740] [10de:0fc8] (rev a1)
0000:26:00.0 VGA compatible controller [0300]: NVIDIA Corporation GM204 [GeForce GTX 970] [10de:13c2] (rev a1)

I installed X using:

sudo pacman -Syu && sudo pacman -S xorg xorg-server

I'm using nvidia proprietary drivers which were installed using:

sudo pacman -Syu && sudo pacman -S nvidia nvidia-utils

Last edited by hypothermic (2020-10-15 13:32:12)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 24,079

Re: X fails with "no screens found" error on boot

Post the entire log. Did you pass through/define the wrong card?

hypothermic

Member

Registered: 2020-08-20

Posts: 6

Re: X fails with "no screens found" error on boot

Log file contents

I passed the GTX 970 and its HDMI audio controller through by using these kernel parameters:

amd_iommu=force_isolation vfio-pci.ids=10de:13c2,10de:0fbb video=vesafb:off,efifb:off

Vfio modules are enabled in initramfs and loaded before GPU drivers:

softdep nouveau pre: vfio-pci
softdep nvidia pre: vfio-pci
softdep nvidia-drm: vfio-pci
softdep snd_hda_intel_pre: vfio-pci
options vfio-pci ids=10de:13c2,10de:0fbb

System log shows that the GTX 970 is indeed passed through:

[    0.429310] VFIO - User Level meta-driver version: 0.3
[    0.430832] vfio_pci: add [10de:13c2[ffff:ffff]] class 0x000000/00000000
[    0.430835] vfio_pci: add [10de:0fbb[ffff:ffff]] class 0x000000/00000000
[    1.930293] vfio-pci 0000:26:00.0: enabling device (0100 -> 0103)