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> > > + iommufd_xa_limit_32b, GFP_KERNEL_ACCOUNT); > > > > Just direct use XA_LIMIT() here. > > Ok. > > > btw do we need a contract so vfio can learn 0 and -1 are reserved or > > fine to have a fixed assumption in later patches? > > I doubt how to do it. ☹ @Jason? What about your opinion? It is probably fine to use xa_limit_31b and just say that -ve values are reserved in a comment near the define for 0 Jason