iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO

Enumerate the capabilities from the mock device and test whether it
advertises as expected. Include it as part of the iommufd_dirty_tracking
fixture.

Link: https://lore.kernel.org/r/20231024135109.73787-18-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: jpemartins

drivers/iommu/iommufd/selftest.c

@@ -376,7 +376,18 @@ static phys_addr_t mock_domain_iova_to_phys(struct iommu_domain *domain,
 
 static bool mock_domain_capable(struct device *dev, enum iommu_cap cap)
 {
-	return cap == IOMMU_CAP_CACHE_COHERENCY;
+	struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
+
+	switch (cap) {
+	case IOMMU_CAP_CACHE_COHERENCY:
+		return true;
+	case IOMMU_CAP_DIRTY_TRACKING:
+		return !(mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY);
+	default:
+		break;
+	}
+
+	return false;
 }
 
 static void mock_domain_set_plaform_dma_ops(struct device *dev)

tools/testing/selftests/iommu/iommufd.c

@@ -1563,6 +1563,23 @@ TEST_F(iommufd_dirty_tracking, set_dirty_tracking)
 	test_ioctl_destroy(hwpt_id);
 }
 
+TEST_F(iommufd_dirty_tracking, device_dirty_capability)
+{
+	uint32_t caps = 0;
+	uint32_t stddev_id;
+	uint32_t hwpt_id;
+
+	test_cmd_hwpt_alloc(self->idev_id, self->ioas_id, 0, &hwpt_id);
+	test_cmd_mock_domain(hwpt_id, &stddev_id, NULL, NULL);
+	test_cmd_get_hw_capabilities(self->idev_id, caps,
+				     IOMMU_HW_CAP_DIRTY_TRACKING);
+	ASSERT_EQ(IOMMU_HW_CAP_DIRTY_TRACKING,
+		  caps & IOMMU_HW_CAP_DIRTY_TRACKING);
+
+	test_ioctl_destroy(stddev_id);
+	test_ioctl_destroy(hwpt_id);
+}
+
 TEST_F(iommufd_dirty_tracking, get_dirty_bitmap)
 {
 	uint32_t stddev_id;

tools/testing/selftests/iommu/iommufd_fail_nth.c

@@ -612,7 +612,7 @@ TEST_FAIL_NTH(basic_fail_nth, device)
 				  &idev_id))
 		return -1;
 
-	if (_test_cmd_get_hw_info(self->fd, idev_id, &info, sizeof(info)))
+	if (_test_cmd_get_hw_info(self->fd, idev_id, &info, sizeof(info), NULL))
 		return -1;
 
 	if (_test_cmd_hwpt_alloc(self->fd, idev_id, ioas_id, 0, &hwpt_id))

tools/testing/selftests/iommu/iommufd_utils.h

@@ -535,15 +535,16 @@ static void teardown_iommufd(int fd, struct __test_metadata *_metadata)
 #endif
 
 /* @data can be NULL */
-static int _test_cmd_get_hw_info(int fd, __u32 device_id,
-				 void *data, size_t data_len)
+static int _test_cmd_get_hw_info(int fd, __u32 device_id, void *data,
+				 size_t data_len, uint32_t *capabilities)
 {
 	struct iommu_test_hw_info *info = (struct iommu_test_hw_info *)data;
 	struct iommu_hw_info cmd = {
 		.size = sizeof(cmd),
 		.dev_id = device_id,
 		.data_len = data_len,
 		.data_uptr = (uint64_t)data,
+		.out_capabilities = 0,
 	};
 	int ret;
 
@@ -580,14 +581,19 @@ static int _test_cmd_get_hw_info(int fd, __u32 device_id,
 			assert(!info->flags);
 	}
 
+	if (capabilities)
+		*capabilities = cmd.out_capabilities;
+
 	return 0;
 }
 
-#define test_cmd_get_hw_info(device_id, data, data_len)         \
-	ASSERT_EQ(0, _test_cmd_get_hw_info(self->fd, device_id, \
-					   data, data_len))
+#define test_cmd_get_hw_info(device_id, data, data_len)               \
+	ASSERT_EQ(0, _test_cmd_get_hw_info(self->fd, device_id, data, \
+					   data_len, NULL))
+
+#define test_err_get_hw_info(_errno, device_id, data, data_len)               \
+	EXPECT_ERRNO(_errno, _test_cmd_get_hw_info(self->fd, device_id, data, \
+						   data_len, NULL))
 
-#define test_err_get_hw_info(_errno, device_id, data, data_len) \
-	EXPECT_ERRNO(_errno,                                    \
-		     _test_cmd_get_hw_info(self->fd, device_id, \
-					   data, data_len))
+#define test_cmd_get_hw_capabilities(device_id, caps, mask) \
+	ASSERT_EQ(0, _test_cmd_get_hw_info(self->fd, device_id, NULL, 0, &caps))