Linux VM - No monitor standby (GPU passthrough)

[brightrgb]

I created a Windows 11 and a Linux Mint VM on the same system.
The GPU is passed through to both VMs via passthrough, and the USB ports for the mouse and keyboard are routed from the host to the VM.

The GPU is an RX 6600XT installed on an Asus B550 motherboard.
Everything works fine so far, and I'm sure it's not a Proxmox issue.

When the Windows 11 VM goes into standby after a while, the monitors go into standby.
The same doesn't happen with the Linux Mint VM.

I also installed the GPU in an older computer with the same version of Mint.
There, the monitors go into standby.
So it must be related to the passthrough or the virtualization itself.

Does anyone have any idea why this works in Windows but not in Linux?

 

[Sviat]

HI,

in your Windows 11 VM, the AMD driver properly supports power states (DPMS), so when the OS goes to sleep, the GPU tells the monitors to enter standby.
In Linux Mint, especially under virtualization, the AMD driver often doesn’t fully manage display power states when passed through, so it could be that the signal to turn off the monitors is never sent.