We haven’t put much thought into virtual machine on the Mill, in part because it would appear relatively easy. The Mill has no reserved ops and no supervisor state; all protection is via memory accessibility. Consequently it would seem that VMs arise naturally by replicating the All address space, which is easily done by tacking an ASID on the caches and some specRegs.
Of course, it’s the things that seem simple that are often the most trouble, and I would not be surprised to find that Mill VM is not that easy. But right now we are focused on getting plain vanilla cores to work; VM is on the roadmap, but not an immediate concern.