Thanks for that information. I will make this message short because @stormi is busy but I want to say thanks to Vates and XCP-ng for all their work done to support Windows on the Xen platform. This includes TPM2 and secure boot support and Microsoft-signed pv drivers. Well done!

@planedrop said:

@Chuckz wouldn't the better solution here be to prioritize making Core Isolation work within XCP-ng guests rather than focusing on nested virtualization?

Nested virt has other issues and again should not really be used with high priority VMs.

I guess that's the whole thing I'm getting at, nested virt isn't the fix for this specific issue.

@planedrop That would be cool if core isolation could work directly in XCP-ng guests without help of nested Hyper-V. I already asked @stormi if this is possible in earlier post today:

Chuckz said:

Does XCP-ng support core isolation in Windows 11 guests via some mechanism other than by nested virtualization? I presume that I cannot get core isolation to work in Windows guests because of lack of NV support in Xen.

So far no reply to that question but I only asked earlier today. I presume it is a complex technical question that cannot be answered without discussion with upstream Xen developers.