Nested Virtualization for WSL2 VM

[ameeno]

Greetings,

I am trying to do
Set-VMProcessor -VMName -ExposeVirtualizationExtensions $true

On the wsl2vm itself so I can use KVM inside it.

However, I cannot do that, and I don't know why Get-VM does not see the wsl2vm so I cannot expose these vars.

how do I do it?

[Biswa96]

You can get Hyper-V VM ID with hcsdiag list command as admin. But I don't know if nested virtualization can be done in WSL2. It's like Inception... 🤓

[ameeno]

Hi Biswa96 yes I will try and make it like Inception WIn10 -> wsl(VM) -> KVM -> OSX->Parrallels->Win10 :)

[therealkenc]

I'm on KVM->Win10->WSL2 FWIW.

[kterhorst]

I am interested in this as well. Is there any way to enable ExposeVirtualizationExtensions for the Hyper-V instance running WSL2?

[ameeno]

Well my main desktop rig has been rebuilt around ryzen 3600. Unfortunately, windows does not support nested virtualization in any form for and processors. So it seems a linux Kvm host as the base operating system is required now.

You can enable nested in kvm and have osx and windows 10 SMS with pic box pass through which is almost natively Experiance. However you need two graphics cards. 1 for linux and 1 for your vm.

[scottjoshuac]

This would be very useful to have, that way I don't have to have two separate Linux VMs (WSL2 + my GNS3 VM). Please enable this feature as it's already built into Hyper-V.

[tsujp]

Is there any comment on if and when this will be a thing? It's kind of a requirement for WSL2 to be actually useful, not being able to run VMs with KVM for hardware acceleration in 2019 is a bit.. concerning.

I used WSL1 and it topped out being useful at letting me type Linux commands as it used to have all manner of port issues, restrictions, slowdowns and the like. WSL2 might be faster with I/O but VMs are a CORE REQUIREMENT of any remotely professional setup.

If Microsoft want people to use Windows with WSL2 as a host operating system, WSL2 must support KVM or there needs to be another non-Intel way to get hardware virtualization working.

[steffengy]

Technically there's already everything in place for it to work.

If someone wants to play with this right now with an insider build:

1. Build a kernel with KVM support (missing kvm_intel & msr mostly).
2. Pass ExposeVirtualizationExtensions to the utility VM and boot a different kernel.
   This is very hacky.
   Let me know, if you can't wait or are interested in a 1-click workaround.

Et voilà

Point 1) in Microsofts upstream kernel might lead to a bit of discussion, but with both
kvm_intel & kvm_amd as kernel modules everybody should be happy?
For 2) it's either allowing configuration or just passing true.

[scottjoshuac]

Yep, they just need to enable the "ExposeVirtualizationExtensions" feature as it's only available to Hyper-V machines that are in the Hyper-V manager. Since the WSL2 VM does not have a name, we can't apply it.

[steffengy]

Joshua (@scottjoshuac)
Technically you can as the screenshot above shows, it's just not easy at all because
it doesn't seem to be an intended feature yet ;)
(The WSL2 VM is hosted through HCS, therefore doesn't show up in hyperV,
which the powershell CMDLets use. Also a new VM is created each time, so for a workaround
you need to intercept its creation and set ExposeVirtualizationExtensions before its started up)