Cyclical login problem on GPU passthrough to Ubuntu VM

Graphics / Linux Linux
1

I mapped a Quadro K4000 into Ubuntu18.04 VM (QEMU-KVM), installed driver 450.80.02 Linux 64-bit.
After reboot, i was stuck in “cyclical login” state (after input password in login window, just got the login window again!)

I also tried CentOS 7 VM, the same problem.
And it works fine on Windows VM.

Please help me on this, thanks a lot!

Refer to the following detailed information:
1. dmesg

dmesg
dmesg1463×284 72.5 KB

2. It seemed nouveau was disabled, nvidia was loaded, and also qxl was loaded

lsmod
lsmod791×309 35.7 KB

3. lspci
got Quadro K4000

lspci_nvidia
lspci_nvidia1457×385 77.2 KB

and also QXL
lspci_qxl
lspci_qxl1473×321 67.6 KB

4. nvidia-smi

nvidia-smi
nvidia-smi944×526 73.3 KB

5. xorg.conf (generated by nvidia installer)

xorg.conf
xorg.conf591×875 70.1 KB

6. Xorg.0.log

Xorg.0.log_1
Xorg.0.log_11274×896 158 KB

Xorg.0.log_2
Xorg.0.log_21458×892 207 KB

Xorg.0.log_3
Xorg.0.log_3748×888 153 KB

Xorg.0.log_4
Xorg.0.log_4840×255 37 KB

2

Please try with a minimal xorg.conf

Section "Device"
  Identifier "nvidia"
  Driver "nvidia"
  BusID "PCI:7:0:0"
EndSection

and have a monitor connected to the Quadro.

3

Hi generix
Thank you for help.
Just come back for vacation, try your xorg.conf, and the problem is not resolved ( And also failed after a monitor was connected to the GPU.)
Cause i am using VM, so i can only connect a monitor to Host Server ( physical machine into which K4000 is plugged and on which VM is running). And i access the VM from my laptop via remote-viewer(SPICE).

4

Ok, that’s a whole different story. The remote viewer just connects to the virtual graphics device in quemu, not to a real Xserver that would run on the nvidia gpu.
This would require either connecting to the Xserver using e.g. x11vnc or using VirtualGL.
In general, to have an Xserver starting on an Nvidia gpu without monitor,
Option “AllowEmptyInitialConfig” “true”
or
Option “UseDisplayDevice” “none”
has to be added to the device section.

5

generix,
Thanks for explanation, I’ll try.