Re: [PATCH v1 05/12] iommu: Introduce get_viommu_size and viommu_init ops

[Nicolin Chen]

On Thu, Jun 12, 2025 at 08:12:29AM +0000, Tian, Kevin wrote:
> > From: Nicolin Chen <nicolinc@xxxxxxxxxx>
> > Sent: Tuesday, June 10, 2025 1:13 AM
> > + * @get_viommu_size: Get the size of a driver-level vIOMMU structure for a
> > given
> > + *                   @dev corresponding to @viommu_type. Driver should return
> > an
> > + *                   errno if vIOMMU isn't supported accordingly. It is required
> > + *                   for driver to use the VIOMMU_STRUCT_SIZE macro to sanitize
> > + *                   a driver-level vIOMMU structure related to the core one
> 
> What about returning size with '0' indicating NOSUPPORT?

I tend to support other errnos here. Basically this moves all the
driver-level sanity checks from viommu_alloc to get_viommu_size,
to reject an incompatible case immediately before allocating any
structure. And there can be another errno than EOPNOTSUPP.

Thanks
Nicolin