bhyve entered ddb: Stopped at rdmsr

[Christian Barthel]

Hello,

I switched my notebook from a ThinkPad X230 to ThinkPad T480
(each running 12.1).  I noticed that one of my OpenBSD (6.3)
bhyve VMs is not booting anymore.  It stops with a debugger
prompt:

acpi0: sleep states S5
acpi0: tables DSDT FACP HPET APIC MCFG SPCR
acpi0: wakeup devices
acpitimer0 at acpi0: 3579545 Hz, 32 bits
acpihpet0 at acpi0: 16777216 Hz
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz, 1992.07 MHz
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,PBE,SSE3,PCLMUL,DTES64,DS-CPL,SSSE3,SDBG,FMA3,CX16,xTPR,PCID,SSE4.1,SSE4.2,MOVBE,POPCNT,AES,XSAVE,AVX,F16C,RDRAND,HV,NXE,PAGE1GB,LONG,LAHF,ABM,3DNOWP,ITSC,FSGSBASE,BMI1,AVX2,BMI2,ERMS,INVPCID,RDSEED,ARAT,MELTDOWN
cpu0: 256KB 64b/line 8-way L2 cache
rdmsr to register 0xc80 on vcpu 0
                                 kernel: protection fault trap, code=0
Stopped at      identifycpu+0x75c:      rdmsr
ddb{0}> 


Does anyone know why / how to boot the VM?
This VM runs fine on the X230 model but not on the T480.
Other guests (FreeBSD, Ubuntu) run fine on the T480 model as
well.

Thanks!
-- 
Christian Barthel <bch at online.de>