CURRENT: Operation not supported by device

Hello,

I've been using bhyve for a while now and in the past couple days 
(though I'm not sure when it started, certainly less than two 
weeks ago), I've been getting this message when trying to start a 
VM on CURRENT:

# # This is after unloading vmm
# sh /usr/share/examples/bhyve/vmrun.sh -E -I null.iso -d 
  disk0.img test
*** vmm.ko is not loaded
# kldload vmm
# sh /usr/share/examples/bhyve/vmrun.sh -E -I null.iso -d 
  disk0.img test
Launching virtual machine "test" ...
device emulation initialization error: Operation not supported by 
device
# bhyvectl --vm=test --destroy
# kldunload vmm


FWIW, there have been no changes on the BIOS, as can be seen vmm 
loads without issues or warnings.
I usually use vm-bhyve, but was trying to discard that by going 
back to the basics.

Would greatly appreciate pointers as to where to look in order to 
be able to use bhyve again :-).

This is the CPU as reported on dmesg:

CPU: AMD Ryzen 7 PRO 2700U w/ Radeon Vega Mobile Gfx (2196.04-MHz 
K8-class CPU)
  Origin="AuthenticAMD"  Id=0x810f10  Family=0x17  Model=0x11 
  Stepping=0
  Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT>
  Features2=0x7ed8320b<SSE3,PCLMULQDQ,MON,SSSE3,FMA,CX16,SSE4.1,SSE4.2,MOVBE,POPCNT,AESNI,XSAVE,OSXSAVE,AVX,F16C,RDRAND>
  AMD Features=0x2e500800<SYSCALL,NX,MMX+,FFXSR,Page1GB,RDTSCP,LM>
  AMD 
  Features2=0x35c233ff<LAHF,CMP,SVM,ExtAPIC,CR8,ABM,SSE4A,MAS,Prefetch,OSVW,SKINIT,WDT,TCE,Topology,PCXC,PNXC,DBE,PL2I,MWAITX>
  Structured Extended 
  Features=0x209c01a9<FSGSBASE,BMI1,AVX2,SMEP,BMI2,RDSEED,ADX,SMAP,CLFLUSHOPT,SHA>
  XSAVE Features=0xf<XSAVEOPT,XSAVEC,XINUSE,XSAVES>
  AMD Extended Feature Extensions ID 
  EBX=0x1007<CLZERO,IRPerf,XSaveErPtr,IBPB>
  SVM: NP,NRIP,VClean,AFlush,DAssist,NAsids=32768
  TSC: P-state invariant, performance statistics

And on with sysctl dev.cpu.0 (there are 0-7 of these)
dev.cpu.0.cx_method: C1/hlt C2/io
dev.cpu.0.cx_usage_counters: 415801 517428
dev.cpu.0.cx_usage: 44.55% 55.44% last 2765us
dev.cpu.0.cx_lowest: C8
dev.cpu.0.cx_supported: C1/1/1 C2/2/400
dev.cpu.0.freq_levels: 2200/2681 1700/1615 1600/1460
dev.cpu.0.freq: 2200
dev.cpu.0.%parent: acpi0
dev.cpu.0.%pnpinfo: _HID=none _UID=0 _CID=none
dev.cpu.0.%location: handle=\_PR_.C000
dev.cpu.0.%driver: cpu
dev.cpu.0.%desc: ACPI CPU

Thanks in advance for any pointers!
--
Evilham