11-RELEASE and live migration

[Jay West]

Roger wrote...
> I'm able to see these glitches, as said the VM doesn't really hang, it 
> just gets stuck for a long time (and I think that depends on the 
> uptime differences between the source and destination hosts). In the 
> meantime, could you please test if changing the timecounter from 
> XENTIMER to any other (like HPET or
> ACPI-fast) solves the issue?
> 
> # sysctl -w kern.timecounter.hardware=ACPI-fast

Christian replied...
I changed the timecounter from XENTIMER to ACPI-fast and then I did about 10
migrations between our 3 hosts. I always started the next migration a few
seconds after the previous migration finished. The VM didn't stuck now and I
didn't see the VGABios screen on the console.

I can also add to this... changing timecounter to ACPI-fast definitely fixes
the problem. I can migrate a handful of freebsd11 vm's back and forth and
all stay running correctly.

So... bug in XENTIMER?