PMAP_MAX_PKRU_IDX
MPASS(keyidx <= PMAP_MAX_PKRU_IDX);
if (pmap->pm_type != PT_X86 || keyidx > PMAP_MAX_PKRU_IDX ||
#define X86_PG_PKU_MASK X86_PG_PKU(PMAP_MAX_PKRU_IDX)