host, bhyve vm and ntpd

[Michael Voorhis]

Ian Lepore writes:
> Beyond that, I'm not sure what else to try.  It might be necessary to
> get some bhyve developers involved (I know almost nothing about it).

NTPD behaves more normally on uniprocessor VMs.

A FreeBSD bhyve-guest running on a freebsd host will select a
different timecounter depending on whether it is a multiprocessor or a
uniprocessor.  My uniprocessor bhyve-vm selected TSC-low as the best
timecounter in a uniprocessor.  NTP functions there as expected.

kern.timecounter.choice: TSC-low(1000) ACPI-fast(900) HPET(950) i8254(0) dummy(-1000000)
kern.timecounter.hardware: TSC-low

The very same VM, when given two total CPUs, selected HPET (if I
recall) and the timekeeping with NTPD was unreliable, with many
step-resets to the clock.