iommufd/selftest: Test IOMMU_HWPT_ALLOC_DIRTY_TRACKING

In order to selftest the iommu domain dirty enforcing implement the
mock_domain necessary support and add a new dev_flags to test that the
hwpt_alloc/attach_device fails as expected.

Expand the existing mock_domain fixture with a enforce_dirty test that
exercises the hwpt_alloc and device attachment.

Link: https://lore.kernel.org/r/20231024135109.73787-15-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/iommu/iommufd/selftest.c

@@ -119,6 +119,11 @@ static void mock_domain_blocking_free(struct iommu_domain *domain)
 static int mock_domain_nop_attach(struct iommu_domain *domain,
 				  struct device *dev)
 {
+	struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
+
+	if (domain->dirty_ops && (mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY))
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -147,6 +152,25 @@ static void *mock_domain_hw_info(struct device *dev, u32 *length, u32 *type)
 	return info;
 }
 
+static int mock_domain_set_dirty_tracking(struct iommu_domain *domain,
+					  bool enable)
+{
+	return 0;
+}
+
+static int mock_domain_read_and_clear_dirty(struct iommu_domain *domain,
+					    unsigned long iova, size_t size,
+					    unsigned long flags,
+					    struct iommu_dirty_bitmap *dirty)
+{
+	return 0;
+}
+
+const struct iommu_dirty_ops dirty_ops = {
+	.set_dirty_tracking = mock_domain_set_dirty_tracking,
+	.read_and_clear_dirty = mock_domain_read_and_clear_dirty,
+};
+
 static const struct iommu_ops mock_ops;
 
 static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type)
@@ -174,12 +198,20 @@ static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type)
 static struct iommu_domain *
 mock_domain_alloc_user(struct device *dev, u32 flags)
 {
+	struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
 	struct iommu_domain *domain;
 
-	if (flags & (~IOMMU_HWPT_ALLOC_NEST_PARENT))
+	if (flags &
+	    (~(IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING)))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	if ((flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING) &&
+	    (mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY))
 		return ERR_PTR(-EOPNOTSUPP);
 
 	domain = mock_domain_alloc(IOMMU_DOMAIN_UNMANAGED);
+	if (domain && !(mdev->flags & MOCK_FLAGS_DEVICE_NO_DIRTY))
+		domain->dirty_ops = &dirty_ops;
 	if (!domain)
 		domain = ERR_PTR(-ENOMEM);
 	return domain;
@@ -387,6 +419,9 @@ static struct mock_dev *mock_dev_create(unsigned long dev_flags)
 	struct mock_dev *mdev;
 	int rc;
 
+	if (dev_flags & ~(MOCK_FLAGS_DEVICE_NO_DIRTY))
+		return ERR_PTR(-EINVAL);
+
 	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
 	if (!mdev)
 		return ERR_PTR(-ENOMEM);

tools/testing/selftests/iommu/iommufd.c

@@ -1433,6 +1433,55 @@ TEST_F(iommufd_mock_domain, alloc_hwpt)
 	}
 }
 
+FIXTURE(iommufd_dirty_tracking)
+{
+	int fd;
+	uint32_t ioas_id;
+	uint32_t hwpt_id;
+	uint32_t stdev_id;
+	uint32_t idev_id;
+};
+
+FIXTURE_SETUP(iommufd_dirty_tracking)
+{
+	self->fd = open("/dev/iommu", O_RDWR);
+	ASSERT_NE(-1, self->fd);
+
+	test_ioctl_ioas_alloc(&self->ioas_id);
+	test_cmd_mock_domain(self->ioas_id, &self->stdev_id, &self->hwpt_id,
+			     &self->idev_id);
+}
+
+FIXTURE_TEARDOWN(iommufd_dirty_tracking)
+{
+	teardown_iommufd(self->fd, _metadata);
+}
+
+TEST_F(iommufd_dirty_tracking, enforce_dirty)
+{
+	uint32_t ioas_id, stddev_id, idev_id;
+	uint32_t hwpt_id, _hwpt_id;
+	uint32_t dev_flags;
+
+	/* Regular case */
+	dev_flags = MOCK_FLAGS_DEVICE_NO_DIRTY;
+	test_cmd_hwpt_alloc(self->idev_id, self->ioas_id,
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING, &hwpt_id);
+	test_cmd_mock_domain(hwpt_id, &stddev_id, NULL, NULL);
+	test_err_mock_domain_flags(EINVAL, hwpt_id, dev_flags, &stddev_id,
+				   NULL);
+	test_ioctl_destroy(stddev_id);
+	test_ioctl_destroy(hwpt_id);
+
+	/* IOMMU device does not support dirty tracking */
+	test_ioctl_ioas_alloc(&ioas_id);
+	test_cmd_mock_domain_flags(ioas_id, dev_flags, &stddev_id, &_hwpt_id,
+				   &idev_id);
+	test_err_hwpt_alloc(EOPNOTSUPP, idev_id, ioas_id,
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING, &hwpt_id);
+	test_ioctl_destroy(stddev_id);
+}
+
 /* VFIO compatibility IOCTLs */
 
 TEST_F(iommufd, simple_ioctls)

tools/testing/selftests/iommu/iommufd_utils.h

@@ -98,6 +98,9 @@ static int _test_cmd_mock_domain_flags(int fd, unsigned int ioas_id,
 		*idev_id = cmd.mock_domain_flags.out_idev_id;
 	return 0;
 }
+#define test_cmd_mock_domain_flags(ioas_id, flags, stdev_id, hwpt_id, idev_id) \
+	ASSERT_EQ(0, _test_cmd_mock_domain_flags(self->fd, ioas_id, flags,     \
+						 stdev_id, hwpt_id, idev_id))
 #define test_err_mock_domain_flags(_errno, ioas_id, flags, stdev_id, hwpt_id) \
 	EXPECT_ERRNO(_errno,                                                  \
 		     _test_cmd_mock_domain_flags(self->fd, ioas_id, flags,    \