Re: [PATCH v6 02/10] iommu: Pass in parent domain with user_data to domain_alloc_user op

[Joao Martins <joao.m.martins@oracle.com>]

On 24/10/2023 16:06, Yi Liu wrote:
> domain_alloc_user op already accepts user flags for domain allocation, add
> a parent domain pointer and a driver specific user data support as well.
> 
> Add a struct iommu_user_data as a bundle of data_ptr/data_len/type from an
> iommufd core uAPI structure. Make the user data opaque to the core, since
> a userspace driver must match the kernel driver. In the future, if drivers
> share some common parameter, there would be a generic parameter as well.
> 
> Define an enum iommu_hwpt_data_type (with IOMMU_HWPT_DATA_NONE type) for
> iommu drivers to add their own driver specific user data per hw_pagetable.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
>  drivers/iommu/intel/iommu.c          |  7 ++++++-

You are sadly missing AMD IOMMU

This would fix the build and nack the op should parent or user_data be passed:

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index caad10f9cee3..bc747513afcb 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2220,13 +2220,17 @@ static struct iommu_domain
*amd_iommu_domain_alloc(unsigned int type)
 }

 static struct iommu_domain *amd_iommu_domain_alloc_user(struct device *dev,
-                                                       u32 flags)
+                                       u32 flags, struct iommu_domain *parent,
+                                       const struct iommu_user_data *user_data)
 {
        unsigned int type = IOMMU_DOMAIN_UNMANAGED;

        if (flags & ~IOMMU_HWPT_ALLOC_DIRTY_TRACKING)
                return ERR_PTR(-EOPNOTSUPP);

+       if (parent || user_data)
+               return ERR_PTR(-EOPNOTSUPP);
+
        return do_iommu_domain_alloc(type, dev, flags);
 }