Windows 11 24H2 WSL2 - wsl: Nested virtualization is not supported on this machine message

[AnalogKid]

Hello, hoping that someone here knows how to fix this. It is not debilitating. It still works, but it is annoying.

I have a Windows 11 24H2 virtual machine machine running on Promox (proxmox-ve: 8.2.0 (running kernel: 6.8.12-2-pve)) that I have configured to also run WSL2.

The machine currently has Ubuntu 22.04 and 24.04 WSL2 OS instances installed. Both instances start and run fine. Everything works except there is this message the first time that I start up a WSL instance:

wsl: Nested virtualization is not supported on this machine

This only happens for the first instance launched. Any additional instances launched do not have this error.

To be clear, this the setup:
Computer Hardware > Proxmox installed directly > Win11 VM running on Proxmox server > WSL2 inside Win11 VM

This is the message that I get the first time the I launch a WSL VM. This is Ubuntu 24.04



There is no message for any subsequent WSL VM's launched during the same session.

This is Ubuntu 22.04



It does not matter what order they are launched in. Whichever one is launched first get the error message.

Does anyone know how to fix this?

Thanks!

 

[dakralex]

Hi!

AFAIK, this just a warning message from WSL, therefore it only shows up the first time you launch it. Have you enabled nested virtualization as described at [0] on your Proxmox host and set the Windows VM's CPU type to host? If this does not help, what's your physical CPU? Does it support nested virtualization on hardware?

[0] https://pve.proxmox.com/wiki/Nested_Virtualization#Enable_Nested_Hardware-assisted_Virtualization

 

[AnalogKid]

Yes, I have enabled the Nested Virtualization as per the Proxmox documentation. I believe that the necessary Proxmox configurations are set correctly and the VM guest CPU is set to host




The physical CPU is 16 x AMD Ryzen 7 8845HS w/ Radeon 780M Graphics (1 Socket)

An Internet search says that this CPU does support nested virtalization.



Any other thoughts?

 

[dakralex]

Hi!

Is there a specific reason that you added -hypervisor to your CPU flags? Does the warning persist if you remove it? If not, does the warning show with all Hyper-V enlightenments removed? Is there any log information in the VM's start task log?