[PATCH v7 4/9] iommufd/selftest: Add mock_domain_cache_invalidate_user support

[Yi Liu <yi.l.liu@xxxxxxxxx>]

From: Nicolin Chen <nicolinc@xxxxxxxxxx>

Add mock_domain_cache_invalidate_user() data structure to support user
space selftest program to cover user cache invalidation pathway.

Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Co-developed-by: Yi Liu <yi.l.liu@xxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
 drivers/iommu/iommufd/iommufd_test.h | 34 ++++++++++++++
 drivers/iommu/iommufd/selftest.c     | 67 ++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+)

diff --git a/drivers/iommu/iommufd/iommufd_test.h b/drivers/iommu/iommufd/iommufd_test.h
index 7910fbe1962d..15dd74d361f9 100644
--- a/drivers/iommu/iommufd/iommufd_test.h
+++ b/drivers/iommu/iommufd/iommufd_test.h
@@ -148,4 +148,38 @@ struct iommu_hwpt_selftest {
 	__u32 iotlb;
 };
 
+/* Should not be equal to any defined value in enum iommu_hwpt_invalidate_data_type */
+#define IOMMU_HWPT_INVALIDATE_DATA_SELFTEST 0xdeadbeef
+#define IOMMU_HWPT_INVALIDATE_DATA_SELFTEST_INVALID 0xdadbeef
+
+/**
+ * enum iommu_hwpt_invalidate_selftest_result_code - Result of invalidation
+ * @IOMMU_TEST_INVALIDATE_SUCC: Success
+ * @IOMMU_TEST_INVALIDATE_FAKE_ERROR: Fake error per test program's request
+ */
+enum iommu_hwpt_invalidate_selftest_result_code {
+	IOMMU_TEST_INVALIDATE_SUCC,
+	IOMMU_TEST_INVALIDATE_FAKE_ERROR,
+};
+
+/**
+ * struct iommu_hwpt_invalidate_selftest
+ *
+ * @flags: Invalidate flags
+ * @iotlb_id: Invalidate iotlb entry index
+ * @code: One of enum iommu_hwpt_invalidate_selftest_result_code
+ * @__reserved: Must be 0
+ *
+ * If IOMMU_TEST_INVALIDATE_ALL is set in @flags, @iotlb_id will be ignored
+ * @code meaningful only if the request is processed successfully.
+ */
+struct iommu_hwpt_invalidate_selftest {
+#define IOMMU_TEST_INVALIDATE_FLAG_ALL	(1ULL << 0)
+#define IOMMU_TEST_INVALIDATE_FLAG_TRIGGER_ERROR	(1ULL << 1)
+	__u32 flags;
+	__u32 iotlb_id;
+	__u32 code;
+	__u32 __reserved;
+};
+
 #endif
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 022ef8f55088..0eb4e7a05f4a 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -473,9 +473,76 @@ static void mock_domain_free_nested(struct iommu_domain *domain)
 	kfree(mock_nested);
 }
 
+static int
+mock_domain_cache_invalidate_user(struct iommu_domain *domain,
+				  struct iommu_user_data_array *array)
+{
+	struct mock_iommu_domain_nested *mock_nested =
+		container_of(domain, struct mock_iommu_domain_nested, domain);
+	u32 error_code = IOMMU_TEST_INVALIDATE_SUCC, processed = 0;
+	struct iommu_hwpt_invalidate_selftest inv;
+	int i = 0, j;
+	int rc = 0;
+
+	if (array->type != IOMMU_HWPT_INVALIDATE_DATA_SELFTEST) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	for ( ; i < array->entry_num; i++) {
+		rc = iommu_copy_struct_from_user_array(&inv, array,
+						       IOMMU_HWPT_INVALIDATE_DATA_SELFTEST,
+						       i, __reserved);
+		if (rc)
+			break;
+
+		if ((inv.flags & ~(IOMMU_TEST_INVALIDATE_FLAG_ALL |
+				  IOMMU_TEST_INVALIDATE_FLAG_TRIGGER_ERROR)) ||
+		    inv.__reserved) {
+			rc = -EOPNOTSUPP;
+			break;
+		}
+
+		if ((inv.flags & IOMMU_TEST_INVALIDATE_FLAG_ALL) &&
+		    (inv.flags & IOMMU_TEST_INVALIDATE_FLAG_TRIGGER_ERROR)) {
+			rc = -EINVAL;
+			break;
+		}
+
+		if (inv.iotlb_id > MOCK_NESTED_DOMAIN_IOTLB_ID_MAX) {
+			rc = -EINVAL;
+			break;
+		}
+
+		if (inv.flags & IOMMU_TEST_INVALIDATE_FLAG_TRIGGER_ERROR) {
+			error_code = IOMMU_TEST_INVALIDATE_FAKE_ERROR;
+		} else if (inv.flags & IOMMU_TEST_INVALIDATE_FLAG_ALL) {
+			/* Invalidate all mock iotlb entries and ignore iotlb_id */
+			for (j = 0; j < MOCK_NESTED_DOMAIN_IOTLB_NUM; j++)
+				mock_nested->iotlb[j] = 0;
+		} else {
+			mock_nested->iotlb[inv.iotlb_id] = 0;
+		}
+
+		/* error code only cover mock iommu errors */
+		inv.code = error_code;
+		rc = iommu_respond_struct_to_user_array(array, i, (void *)&inv,
+							sizeof(inv));
+		if (rc)
+			break;
+
+		processed++;
+	}
+
+out:
+	array->entry_num = processed;
+	return rc;
+}
+
 static struct iommu_domain_ops domain_nested_ops = {
 	.free = mock_domain_free_nested,
 	.attach_dev = mock_domain_nop_attach,
+	.cache_invalidate_user = mock_domain_cache_invalidate_user,
 };
 
 static inline struct iommufd_hw_pagetable *
-- 
2.34.1