HyperV Nested Virtualization on AMD Threadripper Pro

[Keliaxx]

I've been scouring the interwebs trying to find an answer to this and I read that it was fixed in kernel 6.1 (see here):

 

https://bugzilla.kernel.org/show_bug.cgi?id=155211

 

Alas 6.12RC3 with kernel 6.1.23 seems to still exhibit this problem.  When trying to use nested virtualization in Windows 11 for things like WSL and WSA, you get the following in the host dmesg.  Would anyone happen to know if / what kvm cpu parameter voodoo might allow one to trick Windows 11 into playing nice?  I've tried stripping the hypervisor property and forcing the svm capability flags with no luck.  Within the respective VM, Windows is quick to announce that nested virtualization is not supported on the platform when you launch WSL2.

 

[ 3830.698973] SVM: kvm [19055]: vcpu0, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3831.069250] SVM: kvm [19055]: vcpu1, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3831.193400] SVM: kvm [19055]: vcpu2, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3831.317537] SVM: kvm [19055]: vcpu3, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3831.441694] SVM: kvm [19055]: vcpu4, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3831.565861] SVM: kvm [19055]: vcpu5, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3831.690037] SVM: kvm [19055]: vcpu6, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3831.814213] SVM: kvm [19055]: vcpu7, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3831.938362] SVM: kvm [19055]: vcpu8, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0
[ 3832.062556] SVM: kvm [19055]: vcpu9, guest rIP: 0xfffff86757387841 unimplemented wrmsr: 0xc0010115 data 0x0

 

[shpitz461]

Does this help?

https://superuser.com/questions/1431148/kvm-nested-virtualbox-windows-guest/1589286#1589286

 

I tried it on my Epyc, initially got same wrmsr errors in dmesg, but after I replaced the <cpu> section i did not get these errors and was able to run WSL and get a command-prompt in Win11.

It did screw up the cpu topology though, so you might need to play with it some more and tweak it.

[Keliaxx]

Just so I'm clear, you replaced the CPU section to have it reporting Intel architecture and attributes on a physical AMD platform?

[cowpig]

I have the same issue. @Keliaxx, were you able to resolve this? It seems proxmox has it resolved their kernel but I am not sure how that relates to unraid's.

 

https://forum.proxmox.com/threads/amd-nested-virtualization-not-working-after-7-1-upgrade.100072/

[Keliaxx]

Unfortunately, no.  I haven't found a solution to the problem yet.  In my case, its annoying but not causing me any major issues at the moment, aside from getting the warning every time I fire up a terminal session.