HV_MAP_GPA_WRITABLE
region->hv_map_flags |= HV_MAP_GPA_WRITABLE;
HV_MAP_GPA_WRITABLE,
u32 flags = HV_MAP_GPA_READABLE | HV_MAP_GPA_WRITABLE |
!(region->hv_map_flags & HV_MAP_GPA_WRITABLE))