On Fri, Sep 11, 2020 at 02:57:52PM -0700, Jacob Pan wrote: > There can be multiple vendor-specific PASID data formats used in UAPI > structures. This patch adds enum type with a last entry which makes > range checking much easier.
But it also makes it much easier to screw up the numbers (which are ABI) by inserting a new value into the middle. I prefer defines here, or alternativly BUILD_BUG_ON() checks for the numbers. Regards, Joerg > > Suggested-by: Alex Williamson <alex.william...@redhat.com> > Reviewed-by: Eric Auger <eric.au...@redhat.com> > Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com> > --- > include/uapi/linux/iommu.h | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h > index b42acc8fe007..7cc6ee6c41f7 100644 > --- a/include/uapi/linux/iommu.h > +++ b/include/uapi/linux/iommu.h > @@ -298,11 +298,16 @@ struct iommu_gpasid_bind_data_vtd { > IOMMU_SVA_VTD_GPASID_PCD | \ > IOMMU_SVA_VTD_GPASID_PWT) > > +enum iommu_pasid_data_format { > + IOMMU_PASID_FORMAT_INTEL_VTD = 1, > + IOMMU_PASID_FORMAT_LAST, > +}; > + > /** > * struct iommu_gpasid_bind_data - Information about device and guest PASID > binding > * @argsz: User filled size of this data > * @version: Version of this data structure > - * @format: PASID table entry format > + * @format: PASID table entry format of enum iommu_pasid_data_format type > * @flags: Additional information on guest bind request > * @gpgd: Guest page directory base of the guest mm to bind > * @hpasid: Process address space ID used for the guest mm in host IOMMU > @@ -321,7 +326,6 @@ struct iommu_gpasid_bind_data { > __u32 argsz; > #define IOMMU_GPASID_BIND_VERSION_1 1 > __u32 version; > -#define IOMMU_PASID_FORMAT_INTEL_VTD 1 > __u32 format; > __u32 addr_width; > #define IOMMU_SVA_GPASID_VAL (1 << 0) /* guest PASID valid */ > -- > 2.7.4 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu