Re: [PATCH v6 20/25] iommu/arm-smmu-v3-iommufd: Add hw_info to impl_ops

[Pranjal Shrivastava <praan@google.com>]

On Fri, Jun 20, 2025 at 10:36:56PM -0700, Nicolin Chen wrote:
> On Fri, Jun 20, 2025 at 03:32:19AM +0000, Pranjal Shrivastava wrote:
> > My point is that in-case someone passed INTEL_VTD type, we would end up
> > calling impl_ops->hw_info and then the impl_ops->hw_info shall check for
> > the type to return -EOPNOTSUPP. Either we should clearly mention that
> > each impl_op implementing hw_info *must* add another type and check for
> > it
> 
> Let's add this:
> 
> @@ -721,6 +721,11 @@ struct arm_smmu_impl_ops {
>         int (*init_structures)(struct arm_smmu_device *smmu);
>         struct arm_smmu_cmdq *(*get_secondary_cmdq)(
>                 struct arm_smmu_device *smmu, struct arm_smmu_cmdq_ent *ent);
> +       /*
> +        * An implementation should define its own type other than the default
> +        * IOMMU_HW_INFO_TYPE_ARM_SMMUV3. And it must validate the input @type
> +        * to return its own structure.
> +        */
>         void *(*hw_info)(struct arm_smmu_device *smmu, u32 *length, u32 *type);
>         const size_t vsmmu_size;
>         const enum iommu_viommu_type vsmmu_type;
> 
> And I found that we could have another patch changing "u32 *type"
> to "enum iommufd_hw_info_flags *type" to avoid some duplications
> in the kdocs.
> 

Yea, that sounds good. Thanks!

> Thanks
> Nicolin