vm_mem_init
error = vm_mem_init(&vm->mem, 0, VM_MAXUSER_ADDRESS_LA48);
error = vm_mem_init(&vm->mem, 0, 1ul << 39);
int vm_mem_init(struct vm_mem *mem, vm_offset_t lo, vm_offset_t hi);
error = vm_mem_init(&vm->mem, 0, 1ul << 39);
static void vm_mem_init(void *);
SYSINIT(vm_mem, SI_SUB_VM, SI_ORDER_FIRST, vm_mem_init, NULL);