> From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Sent: Monday, November 20, 2023 4:30 PM > > On 2023/11/20 16:09, Tian, Kevin wrote: > >> From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > >> Sent: Friday, November 17, 2023 9:07 PM > >> + * @req_len: Length (in bytes) of a request entry in the request array > >> + * @req_num: Input the number of cache invalidation requests in the > array. > >> + * Output the number of requests successfully handled by kernel. > >> + * @out_driver_error_code: Report a driver speicifc error code upon > failure. > >> + * It's optional, driver has a choice to fill it or > >> + * not. > > > > Being optional how does the user tell whether the code is filled or not? > > seems like we need a flag for it. otherwise, a reserved special value is > required. or is it enough to just document it that this field is available > or not per the iommu_hw_info_type? > No guarantee that a reserved special value applies to all vendors. I'll just remove the optional part. the viommu driver knows what a valid code is, if the driver fills it.
