Which stores reference to nested parent domain assigned during the call to
struct iommu_ops.viommu_init(). Information in the nest parent is needed
when setting up the nested translation.

Note that the viommu initialization will be introduced in subsequent
commit.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/amd_iommu_types.h |  6 ++++++
 drivers/iommu/amd/iommu.c           |  4 +++-
 drivers/iommu/amd/iommufd.c         | 17 +++++++++++++++++
 drivers/iommu/amd/iommufd.h         |  5 +++++
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index c34604cf1811..a0c7e7329233 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -17,6 +17,7 @@
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/pci.h>
+#include <linux/iommufd.h>
 #include <linux/irqreturn.h>
 #include <linux/io-pgtable.h>
 
@@ -586,6 +587,11 @@ struct pdom_iommu_info {
 	u32 refcnt;	/* Count of attached dev/pasid per domain/IOMMU */
 };
 
+struct amd_iommu_viommu {
+	struct iommufd_viommu core;
+	struct protection_domain *parent; /* nest parent domain for this viommu */
+};
+
 /*
  * This structure contains generic data for  IOMMU protection domains
  * independent of their use.
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index e489e360bb77..c4ff18adcf03 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3077,7 +3077,9 @@ const struct iommu_ops amd_iommu_ops = {
 		.iotlb_sync	= amd_iommu_iotlb_sync,
 		.free		= amd_iommu_domain_free,
 		.enforce_cache_coherency = amd_iommu_enforce_cache_coherency,
-	}
+	},
+	.get_viommu_size = amd_iommufd_get_viommu_size,
+	.viommu_init = amd_iommufd_viommu_init,
 };
 
 #ifdef CONFIG_IRQ_REMAP
diff --git a/drivers/iommu/amd/iommufd.c b/drivers/iommu/amd/iommufd.c
index 72eaaa923d04..5ba50799a6fa 100644
--- a/drivers/iommu/amd/iommufd.c
+++ b/drivers/iommu/amd/iommufd.c
@@ -29,3 +29,20 @@ void *amd_iommufd_hw_info(struct device *dev, u32 *length, u32 *type)
 
 	return hwinfo;
 }
+
+size_t amd_iommufd_get_viommu_size(struct device *dev, enum iommu_viommu_type viommu_type)
+{
+	return VIOMMU_STRUCT_SIZE(struct amd_iommu_viommu, core);
+}
+
+int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *parent,
+			    const struct iommu_user_data *user_data)
+{
+	struct amd_iommu_viommu *aviommu = container_of(viommu, struct amd_iommu_viommu, core);
+
+	/*
+	 */
+	aviommu->parent = to_pdomain(parent);
+
+	return 0;
+}
diff --git a/drivers/iommu/amd/iommufd.h b/drivers/iommu/amd/iommufd.h
index f880be80a30d..f05aad495b5b 100644
--- a/drivers/iommu/amd/iommufd.h
+++ b/drivers/iommu/amd/iommufd.h
@@ -8,8 +8,13 @@
 
 #if IS_ENABLED(CONFIG_AMD_IOMMU_IOMMUFD)
 void *amd_iommufd_hw_info(struct device *dev, u32 *length, u32 *type);
+size_t amd_iommufd_get_viommu_size(struct device *dev, enum iommu_viommu_type viommu_type);
+int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *parent,
+			    const struct iommu_user_data *user_data);
 #else
 #define amd_iommufd_hw_info NULL
+#define amd_iommufd_viommu_init NULL
+#define amd_iommufd_get_viommu_size NULL
 #endif /* CONFIG_AMD_IOMMU_IOMMUFD */
 
 #endif /* AMD_IOMMUFD_H */
-- 
2.34.1

On Tue, Oct 21, 2025 at 01:43:19AM +0000, Suravee Suthikulpanit wrote:
> Which stores reference to nested parent domain assigned during the call to
> struct iommu_ops.viommu_init(). Information in the nest parent is needed
> when setting up the nested translation.
> 
> Note that the viommu initialization will be introduced in subsequent
> commit.
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>

On Tue, Oct 21, 2025 at 01:43:19AM +0000, Suravee Suthikulpanit wrote:
> +int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *parent,
> +			    const struct iommu_user_data *user_data)
> +{
> +	struct amd_iommu_viommu *aviommu = container_of(viommu, struct amd_iommu_viommu, core);
> +
> +	/*
> +	 */
> +	aviommu->parent = to_pdomain(parent);

Drop the /* */ - otherwise looks OK

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason