bhyve VM interfaces should be better fit
When bhyve was ported to illumos, a makeshift "VM shim" was written to provide the FreeBSD VM interfaces used by bhyve to build/maintain the nested page tables (and associated resources). Keeping source compatibility with upstream bhyve was a priority at that point, which meant replicating FreeBSD interfaces at the cost of simplicity. That area of bhyve ended up being rather circuitous while at the same time being somewhat lacking in capabilities and performance. The current state is a barrier to adding significant features (such as A/D tracking for migration).
As a solution, we propose a significant overhaul of those VM-related interfaces and logic which are consumed by bhyve. The new interfaces should be tailored to what bhyve and its related components need for efficient and straightforward operation.