vmm vmx: Add a global bool to indicate if the host has the TSC_AUX MSR.

[jhb]

Summary

A future commit will remove direct access to vCPU structures from
struct vmx, so add a dedicated boolean for this rather than checking
the capabilities for vCPU 0.

[jhb]

After splitting this out and looking at it again, I think it probably makes sense for it to just be a global bool rather than buried in struct vmx, but I wanted to upload the initial version for comparison.

[jhb]

Switch to a global

[markj]

sys/amd64/vmm/intel/vmx.c

213

Did you mean to add a sysctl for this? It seems a bit odd to stick it in the middle of the sysctl definitions otherwise.

[jhb]

sys/amd64/vmm/intel/vmx.c

213

I did not plan for a sysctl for it, no. I'm not sure where else to put this declaration. I had kind of put it in this block here in between sysctl blocks since it is related to cap_rdpid and cap_rdtscp. I can look to see if I can find a less confusing place for it.

[jhb]

Move declaration