[PATCH v5 07/29] iommufd/selftest: Support user_data in mock_viommu_alloc

[Nicolin Chen <nicolinc@nvidia.com>]

Add a simple user_data for an input-to-output loopback test.

Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/iommufd/iommufd_test.h | 13 +++++++++++++
 drivers/iommu/iommufd/selftest.c     | 17 +++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/iommu/iommufd/iommufd_test.h b/drivers/iommu/iommufd/iommufd_test.h
index 1cd7e8394129..fbf9ecb35a13 100644
--- a/drivers/iommu/iommufd/iommufd_test.h
+++ b/drivers/iommu/iommufd/iommufd_test.h
@@ -227,6 +227,19 @@ struct iommu_hwpt_invalidate_selftest {
 
 #define IOMMU_VIOMMU_TYPE_SELFTEST 0xdeadbeef
 
+/**
+ * struct iommu_viommu_selftest - vIOMMU data for Mock driver
+ *                                (IOMMU_VIOMMU_TYPE_SELFTEST)
+ * @in_data: Input random data from user space
+ * @out_data: Output data (matching @in_data) to user space
+ *
+ * Simply set @out_data=@in_data for a loopback test
+ */
+struct iommu_viommu_selftest {
+	__u32 in_data;
+	__u32 out_data;
+};
+
 /* Should not be equal to any defined value in enum iommu_viommu_invalidate_data_type */
 #define IOMMU_VIOMMU_INVALIDATE_DATA_SELFTEST 0xdeadbeef
 #define IOMMU_VIOMMU_INVALIDATE_DATA_SELFTEST_INVALID 0xdadbeef
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 3d56e2bddb0b..ea2e4c626ad5 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -740,16 +740,33 @@ mock_viommu_alloc(struct device *dev, struct iommu_domain *domain,
 {
 	struct mock_iommu_device *mock_iommu =
 		iommu_get_iommu_dev(dev, struct mock_iommu_device, iommu_dev);
+	struct iommu_viommu_selftest data;
 	struct mock_viommu *mock_viommu;
+	int rc;
 
 	if (viommu_type != IOMMU_VIOMMU_TYPE_SELFTEST)
 		return ERR_PTR(-EOPNOTSUPP);
 
+	if (user_data) {
+		rc = iommu_copy_struct_from_user(
+			&data, user_data, IOMMU_VIOMMU_TYPE_SELFTEST, out_data);
+		if (rc)
+			return ERR_PTR(rc);
+	}
+
 	mock_viommu = iommufd_viommu_alloc(ucmd, struct mock_viommu, core,
 					   &mock_viommu_ops);
 	if (IS_ERR(mock_viommu))
 		return ERR_CAST(mock_viommu);
 
+	if (user_data) {
+		data.out_data = data.in_data;
+		rc = iommu_copy_struct_to_user(
+			user_data, &data, IOMMU_VIOMMU_TYPE_SELFTEST, out_data);
+		if (rc)
+			return ERR_PTR(rc);
+	}
+
 	refcount_inc(&mock_iommu->users);
 	return &mock_viommu->core;
 }
-- 
2.43.0