How if we expand this to a mmu subnode in cpu@x and add a booleans for adornments like svnapot and svpbmt?
The older mmu-type could then treated to indicate a mmu w/o any adornments specified. I am aware that this generates an additional parsing-path that will be maintained, but it will allow future properties to be grouped.
cpu@0 {
...
mmu {
type = "riscv,sv39";
supports-svpbmt;
}
...
}