nested virtualization with vmm on hyper-v

Hi,

I'm a little confused by this. I have an old Xeon e3-1275v3 computer that
runs windows server 2019 essentials natively. It shares half it's RAM and
2 cores with OpenBSD as a hyper-v guest.

So after a long time of not looking into this I asked someone how they did
virtualization nesting and I got this link:

https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-guide/nested-virtualization

So this is good, I thought, I followed the instructions, turned off the hyper-v,
did the powershell command, restarted hyper-v guest and got some indication by
OpenBSD that vmm is enabled:

arda$ dmesg | grep vmm
cpu0: using VERW MDS workaround (except on vmm entry)
vmm0 at mainbus0: VMX/EPT

Only when I start the vmm guest with vmctl and vmctl console, it boots me out
of console mode back into arda and the vmm guest is stopped.

So then I rebooted the entire machine to make sure that all BIOS settings are
correct. And they are. There is no CPU option that I can set here that would
disallow this nesting.

Here is the CPU options of arda (short of a dmesg):

cpu0: using VERW MDS workaround (except on vmm entry)
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Xeon(R) CPU E3-1275 v3 @ 3.50GHz, 3498.01 MHz, 06-3c-03
cpu0: FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SS,HTT,SSE3,PCLMUL,VMX,SSSE3,FMA3,CX16,PCID,SSE4.1,SSE4.2,MOVBE,POPCNT,AES,XSAVE,AVX,F16C,RDRAND,HV,NXE,PAGE1GB,RDTSCP,LONG,LAHF,ABM,FSGSBASE,BMI1,AVX2,SMEP,BMI2,ERMS,INVPCID,MD_CLEAR,IBRS,IBPB,STIBP,L1DF,SSBD,XSAVEOPT,MELTDOWN
cpu0: 256KB 64b/line 8-way L2 cache
cpu0: smt 0, core 0, package 0
cpu0: apic clock running at 200MHz
cpu1 at mainbus0: apid 1 (application processor)
cpu1: Intel(R) Xeon(R) CPU E3-1275 v3 @ 3.50GHz, 3497.99 MHz, 06-3c-03
cpu1: FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SS,HTT,SSE3,PCLMUL,VMX,SSSE3,FMA3,CX16,PCID,SSE4.1,SSE4.2,MOVBE,POPCNT,AES,XSAVE,AVX,F16C,RDRAND,HV,NXE,PAGE1GB,RDTSCP,LONG,LAHF,ABM,FSGSBASE,BMI1,AVX2,SMEP,BMI2,ERMS,INVPCID,MD_CLEAR,IBRS,IBPB,STIBP,L1DF,SSBD,XSAVEOPT,MELTDOWN
cpu1: 256KB 64b/line 8-way L2 cache
cpu1: smt 0, core 1, package 0
cpu0: using VERW MDS workaround (except on vmm entry)

Does anyone know how I can get vmm with nesting to function? Is it a OpenBSD
problem or should I seek elsewhere?

Best Regards,
-peter