AMD passthru on bhyve_svm branch

[Peter Grehan]

Hi Clint,

> I'm not sure if this is supposed to be fully functional yet
   ...
> # dmesg | grep iommu
> amd_iommu_init: not implemented

  The IOMMU isn't yet functional on AMD. Looks like a bug in bhyve that 
it doesn't error out if the IOMMU isn't located and ppt devices have 
been configured.

later,

Peter.