Introduce a new enum iommu_viommu_type (IOMMU_VIOMMU_TYPE_AMD) for AMD
vIOMMU along with the struct iommu_viommu_amd, which is used to initialize
IOMMUFD vIOMMU instance when calling struct iommu_ops.viommu_init().

Also, hook up struct iomufd_viomu_ops.alloc_domain_nested to connect
nested domain allocation with AMD vIOMMU implementation.

Additional initialization will be added in subsequent patches.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/iommufd.c  |  4 ++++
 include/uapi/linux/iommufd.h | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/iommu/amd/iommufd.c b/drivers/iommu/amd/iommufd.c
index ad627fd5ccc7..e7ffa7e8915b 100644
--- a/drivers/iommu/amd/iommufd.c
+++ b/drivers/iommu/amd/iommufd.c
@@ -34,6 +34,9 @@ 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)
 {
+	if (viommu_type != IOMMU_VIOMMU_TYPE_AMD)
+		return 0;
+
 	return VIOMMU_STRUCT_SIZE(struct amd_iommu_viommu, core);
 }
 
@@ -73,5 +76,6 @@ static void amd_iommufd_viommu_destroy(struct iommufd_viommu *viommu)
  * struct iommufd_viommu_ops - vIOMMU specific operations
  */
 static const struct iommufd_viommu_ops amd_viommu_ops = {
+	.alloc_domain_nested = amd_iommu_alloc_domain_nested,
 	.destroy = amd_iommufd_viommu_destroy,
 };
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 1dafbc552d37..3a2ac7234b9e 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -1048,11 +1048,13 @@ struct iommu_fault_alloc {
  * @IOMMU_VIOMMU_TYPE_ARM_SMMUV3: ARM SMMUv3 driver specific type
  * @IOMMU_VIOMMU_TYPE_TEGRA241_CMDQV: NVIDIA Tegra241 CMDQV (extension for ARM
  *                                    SMMUv3) enabled ARM SMMUv3 type
+ * @IOMMU_VIOMMU_TYPE_AMD: AMD HW-vIOMMU type
  */
 enum iommu_viommu_type {
 	IOMMU_VIOMMU_TYPE_DEFAULT = 0,
 	IOMMU_VIOMMU_TYPE_ARM_SMMUV3 = 1,
 	IOMMU_VIOMMU_TYPE_TEGRA241_CMDQV = 2,
+	IOMMU_VIOMMU_TYPE_AMD = 3,
 };
 
 /**
@@ -1071,6 +1073,14 @@ struct iommu_viommu_tegra241_cmdqv {
 	__aligned_u64 out_vintf_mmap_length;
 };
 
+/**
+ * struct iommu_viommu_amd - AMD vIOMMU Interface (IOMMU_VIOMMU_TYPE_AMD)
+ * @reserved: Must be zero
+ */
+struct iommu_viommu_amd {
+	__u32 reserved; /* must be last */
+};
+
 /**
  * struct iommu_viommu_alloc - ioctl(IOMMU_VIOMMU_ALLOC)
  * @size: sizeof(struct iommu_viommu_alloc)
-- 
2.34.1