Enabling hyper-V blue-screens Windows 10 2004 / 19041

[Robert Collins]

Not sure if this should be on kvm or libvirt etc. Anyhow, back in 2017 kvm with nested enabled running hyper-v running vms was documented as being a thing that works, but trying to make that work today I'm just getting blue screens and recovery boots of Windows.

cat /etc/modprobe.d/kvm_intel.conf
options kvm-intel nested=1
options kvm-intel enable_shadow_vmcs=1

This is important for regular Windows 10 guests for several use cases: WSL 2 interop testing, Windows 10's VBS and HVCI (https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/oem-vbs) security features. Making Windows 10 guests secure is important to prevent them become vectors for attack into a network.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: virt-manager 1:2.2.1-3ubuntu2
ProcVersionSignature: Ubuntu 5.4.0-40.44-generic 5.4.44
Uname: Linux 5.4.0-40-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Mon Aug 3 16:50:50 2020
InstallationDate: Installed on 2020-07-07 (26 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
PackageArchitecture: all
SourcePackage: virt-manager
UpgradeStatus: No upgrade log present (probably fresh install)