Disabling speculative execution mitigations

[Peter]

On Fri, 06 Dec 2019 06:21:04 +0100, O'Connor, Daniel <darius at dons.net.au>  
wrote:

> vm.pmap.pti="0"        # Disable page table isolation
> hw.ibrs_disable="1"    # Disable Indirect Branch Restricted Speculation
> hw.mds_disable="0"     # Disable Microarchitectural Data Sampling flush
> hw.vmm.vmx="1"         # Don't flush RSB on vmexit (presumably only  
> affects bhyve etc)
> hw.lazy_fpu_switch="1" # Lazily flush FPU
>
> Does anyone know of any others?

hw.spec_store_bypass_disable=2

I have that on 11.3 (no idea yet about 12). And honestly, I lost track  
which of these should be on, off, automatic, opaque or elsewhere to  
achieve either performance or security (not to mention for which cores and  
under which circumstances it would matter, and what the impact might be),  
and my oracle says this will not end with these.