Nested Hyper-V (Windows 10) with KVM?

[enoch85]

Without `args: -cpu host` it doesn't work to nest Hyper-V.

 

[enoch85]

Hmm, not solved. Just tried running a nested VM again, and after like 5 minutes it's slow again. At this point I don't know if it's my server or something else. Now it have the flags that I wanted, and the CPU type that worked great before. But still, it's slow again.

*Scratching my head*

 

[enoch85]

Just to add some more info:

 

[Republicus]

It looks like its a Win driver issue with kvm64 and vmx. Windows guest OS crashes once I add the vmx flag to cpu args. It wont even boot into the OS installer. On the other hand Linux handles it fine.

But again either it is your disks preforming slowly or something else going on that I can not reproduce. You also said cpu host was necessary where I again am not able to reproduce that. Maybe you need to delete the save state on the HyperV VM before resuming the VM with Broadwell settings?

 

[enoch85]

But what would the difference of Broadwell be? Running host is the same thing, or no?

 

[hoand]

vmx is the flags needed for nested virtualization.

args: -cpu kvm64,vmx=on

This does report vmx flags once added (and absent without that argument in conf) but you may need to install Win10 from scratch with that CPU change. My VM wanted to boot loop and repair with that CPU change.

But the Broadwell changes I suggested should also have worked. My VM starts HyperV VM and Task Manager reports virtualization support:
If you can test kvm64,vmx=on (possibly from new install if needed) of course that seems to be the answer you wanted... im just not sure why Broadwell didn't work when it aught to have.
View attachment 54073

hi sir, I have config follow this but my VM dont start Task Manager reports virtualization support. I try to add command args: -cpu kvm64,vmx=on with cpu: kvm64, bui i see boot loop.