UVMPAGER_MAPIN_READ
if (flags & UVMPAGER_MAPIN_READ)
mapinflags = !write ? UVMPAGER_MAPIN_READ : UVMPAGER_MAPIN_WRITE;
swmapflags = UVMPAGER_MAPIN_READ;
UVMPAGER_MAPIN_READ : UVMPAGER_MAPIN_WRITE;