Do you care to elaborate? You can already do this on Linux with any architecture (x86 or anything else) using cpusets.
The problem of course being that CPUs that rival performance of a decently-specced x86 VM are going to be pricy, mooting the point.
Based on these architectural features Intel has had CAT, which essentially turns LLC slices into private caches for certain cores. That's intended for performance, but is now also relevant for security.