Threadripper 24-core, Nested Virtualization (WSL 2) Issues - IOMMU Enabled, OVMF, Still Failing

[LostandConfused]

Hello Proxmox Community,

I'm encountering persistent issues with nested virtualization on my Proxmox server, specifically when trying to run WSL 2 within a Windows VM. My setup includes:

• Host: Proxmox VE running on a 24-core AMD Threadripper CPU.
• Guest: Windows 10/11 VM LTSC
• Goal: To run WSL 2 within the Windows VM.

What I've Done So Far:

1. IOMMU Enabled:
   • I've confirmed that IOMMU is enabled and configured correctly. My /etc/default/grub file contains amd_iommu=on iommu=pt, and dmesg | grep -i iommu shows proper IOMMU initialization and grouping.
   • dmesg | grep -i iommu output:
2. Virtualization Extensions:
   • lscpu shows that AMD-V is enabled.
3. Proxmox VM Configuration:
   • The VM's CPU type is set to "host" (also tried "kvm64").
   • Nested virtualization is enabled in the VM's "Options" tab.
4. OVMF BIOS:
   • Using OVMF for the windows VM.
   • Proxmox system is fully updated, so I am using the most recent OVMF package in the repositories.
5. Windows Configuration:
   • Hyper-V is enabled in Windows Features.
   • I'm using WSL 2 and have attempted to verify Hyper-V requirements via systeminfo, and powershell.

The Problem:

• When attempting to run WSL 2, I receive an error stating that "the host does not support nested virtualization."
• I have also seen the following error in dmesg:
  • iommu ivhd0: AMD-Vi: Event logged [INVALID_DEVICE_REQUEST device=0000:00:00.0 pasid=0x00000 address=0xfffffffdf8000000 flags=0x0a00]

Questions:

• Are there any known compatibility issues with Threadripper and nested virtualization in Proxmox?
• Could the OVMF BIOS be causing conflicts, and if so, what troubleshooting steps should I take?
• What is the meaning of the error: iommu ivhd0: AMD-Vi: Event logged [INVALID_DEVICE_REQUEST device=0000:00:00.0 pasid=0x00000 address=0xfffffffdf8000000 flags=0x0a00] and how can I resolve it?
• Are there any specific CPU flags or QEMU settings that I should be checking or modifying?
• Are there any further logs that I should be providing to help trouble shoot this issue?

Any guidance or suggestions would be greatly appreciated.
Thank you!"