High Xorg CPU usage on Plex server with iGPU passthrough

[kayamb]

Hi,

I was able to set up iGPU passthrough for my Intel N97. Hardware transcoding is working as expected:



The issue is that, while the Plex server's CPU is very small (as expected), I notice high usage from the "system":



I'm running Plex in a Kubuntu 22.04 VM. Looking at the processes, it seems that the CPU usage is coming from Xorg:



The high CPU usage occurs regardless of whether videos are streaming or not, even after a fresh reboot. So this seems to be unrelated to Plex itself.

Can you tell what might be causing this? Is it something to do with Xorg struggling with the GPU passthrough config?

Below are some screenshots of my config:

 

[kayamb]

Actually, a quick update. I managed to fix it, I think, by setting the "Display" to "none" in the VM's "Hardware" section:



Now the system CPU is under control:



Is that fully expected? Is there any way to continue using the Proxmox console to access the VM's desktop while passing the GPU through?

 

[kayamb]

I was able to get around the console issue. First, in the VM's hardware settings, add a "Serial port 0" device, and set the display to "Serial terminal 0":





Then SSH into the VM and edit the `/etc/default/grub` file, and set the following:

GRUB_CMDLINE_LINUX="console=ttyS0"
GRUB_TERMINAL="console serial"

Then run `sudo upgrade-grub` and reboot the VM.

You should now be able to see the boot procedure in the Proxmox console UI, and be able to interact with the login prompt:



If you want to access the desktop, then SSH into the VM and install a remote desktop server: sudo apt install xrdp

Then you can access the desktop remotely by using a client such as the Windows Remote Desktop app.