Nested Virtualization Under KVM Hypervisor

[Pete Wright]

Hey there,
I have a host that is running via hardware virtualization under KVM and 
am having issues with virtualization.  My provider investigated and 
ensured that the hypervisor was configured to pass through VT-x to 
guests, and reports that Linux guests are detecting VT-x and are able to 
run nested virtualization on their systems.  For FreeBSD this is not 
working - dmesg is reporting this:

CPU: Intel Xeon E312xx (Sandy Bridge) (2600.16-MHz K8-class CPU)
   Origin="GenuineIntel"  Id=0x206a1  Family=0x6  Model=0x2a Stepping=1
Features=0x783fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SSE,SSE2>
Features2=0x9fb82223<SSE3,PCLMULQDQ,VMX,SSSE3,CX16,SSE4.1,SSE4.2,x2APIC,POPCNT,TSCDLT,AESNI,XSAVE,OSXSAVE,AVX,HV>
   AMD Features=0x28100800<SYSCALL,NX,RDTSCP,LM>
   AMD Features2=0x1<LAHF>
   XSAVE Features=0x1<XSAVEOPT>
   VT-x: (disabled in BIOS) PAT,HLT,MTF,PAUSE,EPT,UG,VPID,VID,PostIntr
Hypervisor: Origin = "KVMKVMKVM"
real memory  = 34359738368 (32768 MB)
avail memory = 33365536768 (31819 MB)
Event timer "LAPIC" quality 600
ACPI APIC Table: <BOCHS  BXPCAPIC>

They did verify that VT-x pass through *is* enabled as mentioned above 
(they shared with me the config file snippet on their end to verify), 
and they did extensive testing on their end and were not able to get 
FreeBSD to detect VT-x as being enabled.

I pinged them asking for more info on which Linux kernel their 
hypervisors are running to see if I can help debug this on my end.  I 
have two questions:

1) is anyone else doing nested virtualization under KVM hypervisors.  i 
am confident that this is possible, but am asking for confirmation on 
this :)

2) Are there any other requirements that FreeBSD requires to run Bhyve 
nested under KVM?


Thanks in advance!
-pete

-- 
Pete Wright
pete at nomadlogic.org
@nomadlogicLA