Any way to get nested Hyper-V working on AMD system

[yaro014]

I'm on AMD platform with 3995WX
When I turn on nested KVM support the system becomes a little bit unstable even when VMs are not doing any nested virtualisation.
When I launch Windows10 with WSL2 enabled the VM freezes permanently very quickly after reboot.

I read that nested AMD doesnt work well with Hyper-V, is there any way to make it work ? I had it working ok on intel platform.

 

[dcsapak]

whats your pveversion -v ? did you already try the 5.11 kernel? https://forum.proxmox.com/threads/kernel-5-11.86225/

 

[tom]

Yes, based on my knowledge this works only on Intel CPUs.

See also https://pve.proxmox.com/wiki/Nested_Virtualization

 

[yaro014]

Yes, I am now on latest beta `pve-manager/7.0-5/cce9b25f (running kernel: 5.11.22-1-pve)`
And I have config for nested virtualisation enabled.

root@pve:~# cat /sys/module/kvm_amd/parameters/nested   
1

From time to time I managed to get windows booted and run VM in virtualisation and then it just freezes... nothing in dmesg nor any signs of error.

It's shame it's not working on AMD however, I believe recently discovered bug in AMD/KVM allowing to escape into the host was related to nested virtualization

 

[tom]

It's shame it's not working on AMD however

MS seems to work on this, there were already some improvements, but nothing really use-able (at least for me).

=> Use Intel if you need this feature.

 

[yaro014]

So the PVE documentation now mentions

Note: Microsoft Hyper-V as a nested Hypervisor on AMD CPUs should work with Proxmox VE 7.

https://pve.proxmox.com/wiki/Nested_Virtualization

I'm still unable to boot Win11 with nested virtualisation enabled. Did anyone have any luck with this ?

 

[doge]

Hello i try to make this work too, hope it will one day