Ryzen lockup on bhyve was (Re: new Ryzen lockup issue ?)

[Peter Grehan]

Hi Mike,

>>   I could reproduce this on a Ryzen 1700 with HT enabled - it took ~700
>> seconds, and the entire machine locked up.
>>
>>   An interesting point is a single VM was able to run to completion.
>>
>>   I'll keep testing with various combinations of numbers of VMs,
>> different vCPUs per VM, and pinning guest vCPUs.

  3 4*vCPU guests locked the machine up in ~170 secs, 4 guests ran to 
completion :(

> Not sure if its related to core count or not, but it takes several
> instances on the Epyc to lock up and takes a lot longer. I enabled IOMMU
> on it as well, and it's dmesg shows below.  But the lockups are still
> there with or without it enabled.

  Would you be able to try on the Epyc with vCPUs pinned, and all guest 
vCPUs on different physical CPUs ?

  i.e. for a configuration that will lock up, run the same configuration 
but with vCPUs pinned. For example, a 4 vCPU guest that will have vCPUs 
0-3 pinned to host physical CPUs 7-10 would look like:

  -c 4 -p 0:7 -p 1:8 -p 2:9 -p 3:10

later,

Peter.