iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR flag

Change test_mock_dirty_bitmaps() to pass a flag where it specifies the flag
under test. The test does the same thing as the GET_DIRTY_BITMAP regular
test. Except that it tests whether the dirtied bits are fetched all the
same a second time, as opposed to observing them cleared.

Link: https://lore.kernel.org/r/20231024135109.73787-19-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

@@ -193,13 +193,16 @@ static int mock_domain_read_and_clear_dirty(struct iommu_domain *domain,
 
 		ent = xa_load(&mock->pfns, cur / MOCK_IO_PAGE_SIZE);
 		if (ent && (xa_to_value(ent) & MOCK_PFN_DIRTY_IOVA)) {
-			unsigned long val;
-
 			/* Clear dirty */
-			val = xa_to_value(ent) & ~MOCK_PFN_DIRTY_IOVA;
-			old = xa_store(&mock->pfns, cur / MOCK_IO_PAGE_SIZE,
-				       xa_mk_value(val), GFP_KERNEL);
-			WARN_ON_ONCE(ent != old);
+			if (!(flags & IOMMU_DIRTY_NO_CLEAR)) {
+				unsigned long val;
+
+				val = xa_to_value(ent) & ~MOCK_PFN_DIRTY_IOVA;
+				old = xa_store(&mock->pfns,
+					       cur / MOCK_IO_PAGE_SIZE,
+					       xa_mk_value(val), GFP_KERNEL);
+				WARN_ON_ONCE(ent != old);
+			}
 			iommu_dirty_bitmap_record(dirty, cur,
 						  MOCK_IO_PAGE_SIZE);
 		}

tools/testing/selftests/iommu/iommufd.c

@@ -1598,13 +1598,47 @@ TEST_F(iommufd_dirty_tracking, get_dirty_bitmap)
 
 	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
 				MOCK_APERTURE_START, self->page_size,
-				self->bitmap, self->bitmap_size, _metadata);
+				self->bitmap, self->bitmap_size, 0, _metadata);
 
 	/* PAGE_SIZE unaligned bitmap */
 	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
 				MOCK_APERTURE_START, self->page_size,
 				self->bitmap + MOCK_PAGE_SIZE,
-				self->bitmap_size, _metadata);
+				self->bitmap_size, 0, _metadata);
+
+	test_ioctl_destroy(stddev_id);
+	test_ioctl_destroy(hwpt_id);
+}
+
+TEST_F(iommufd_dirty_tracking, get_dirty_bitmap_no_clear)
+{
+	uint32_t stddev_id;
+	uint32_t hwpt_id;
+	uint32_t ioas_id;
+
+	test_ioctl_ioas_alloc(&ioas_id);
+	test_ioctl_ioas_map_fixed_id(ioas_id, self->buffer,
+				     variant->buffer_size, MOCK_APERTURE_START);
+
+	test_cmd_hwpt_alloc(self->idev_id, ioas_id,
+			    IOMMU_HWPT_ALLOC_DIRTY_TRACKING, &hwpt_id);
+	test_cmd_mock_domain(hwpt_id, &stddev_id, NULL, NULL);
+
+	test_cmd_set_dirty_tracking(hwpt_id, true);
+
+	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
+				MOCK_APERTURE_START, self->page_size,
+				self->bitmap, self->bitmap_size,
+				IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR,
+				_metadata);
+
+	/* Unaligned bitmap */
+	test_mock_dirty_bitmaps(hwpt_id, variant->buffer_size,
+				MOCK_APERTURE_START, self->page_size,
+				self->bitmap + MOCK_PAGE_SIZE,
+				self->bitmap_size,
+				IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR,
+				_metadata);
 
 	test_ioctl_destroy(stddev_id);
 	test_ioctl_destroy(hwpt_id);

tools/testing/selftests/iommu/iommufd_utils.h

@@ -217,11 +217,12 @@ static int _test_cmd_set_dirty_tracking(int fd, __u32 hwpt_id, bool enabled)
 
 static int _test_cmd_get_dirty_bitmap(int fd, __u32 hwpt_id, size_t length,
 				      __u64 iova, size_t page_size,
-				      __u64 *bitmap)
+				      __u64 *bitmap, __u32 flags)
 {
 	struct iommu_hwpt_get_dirty_bitmap cmd = {
 		.size = sizeof(cmd),
 		.hwpt_id = hwpt_id,
+		.flags = flags,
 		.iova = iova,
 		.length = length,
 		.page_size = page_size,
@@ -236,9 +237,9 @@ static int _test_cmd_get_dirty_bitmap(int fd, __u32 hwpt_id, size_t length,
 }
 
 #define test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size,    \
-				  bitmap)                                  \
+				  bitmap, flags)                           \
 	ASSERT_EQ(0, _test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, \
-						page_size, bitmap))
+						page_size, bitmap, flags))
 
 static int _test_cmd_mock_domain_set_dirty(int fd, __u32 hwpt_id, size_t length,
 					   __u64 iova, size_t page_size,
@@ -273,7 +274,7 @@ static int _test_cmd_mock_domain_set_dirty(int fd, __u32 hwpt_id, size_t length,
 
 static int _test_mock_dirty_bitmaps(int fd, __u32 hwpt_id, size_t length,
 				    __u64 iova, size_t page_size, __u64 *bitmap,
-				    __u64 bitmap_size,
+				    __u64 bitmap_size, __u32 flags,
 				    struct __test_metadata *_metadata)
 {
 	unsigned long i, count, nbits = bitmap_size * BITS_PER_BYTE;
@@ -292,25 +293,30 @@ static int _test_mock_dirty_bitmaps(int fd, __u32 hwpt_id, size_t length,
 
 	/* Expect all even bits as dirty in the user bitmap */
 	memset(bitmap, 0, bitmap_size);
-	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap);
+	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap,
+				  flags);
 	for (count = 0, i = 0; i < nbits; count += !(i % 2), i++)
 		ASSERT_EQ(!(i % 2), test_bit(i, (unsigned long *)bitmap));
 	ASSERT_EQ(count, out_dirty);
 
 	memset(bitmap, 0, bitmap_size);
-	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap);
+	test_cmd_get_dirty_bitmap(fd, hwpt_id, length, iova, page_size, bitmap,
+				  flags);
 
 	/* It as read already -- expect all zeroes */
-	for (i = 0; i < nbits; i++)
-		ASSERT_EQ(0, test_bit(i, (unsigned long *)bitmap));
+	for (i = 0; i < nbits; i++) {
+		ASSERT_EQ(!(i % 2) && (flags &
+				       IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR),
+			  test_bit(i, (unsigned long *)bitmap));
+	}
 
 	return 0;
 }
 #define test_mock_dirty_bitmaps(hwpt_id, length, iova, page_size, bitmap,      \
-				bitmap_size, _metadata)                        \
+				bitmap_size, flags, _metadata)                 \
 	ASSERT_EQ(0, _test_mock_dirty_bitmaps(self->fd, hwpt_id, length, iova, \
 					      page_size, bitmap, bitmap_size,  \
-					      _metadata))
+					      flags, _metadata))
 
 static int _test_cmd_create_access(int fd, unsigned int ioas_id,
 				   __u32 *access_id, unsigned int flags)