1 files changed, 209 insertions, 0 deletions

diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index 2709a34a39c5..cce90a10515a 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -23,6 +23,9 @@
 #define  MEM_ALL  (MEM_ANON | MEM_SHMEM | MEM_SHMEM_PRIVATE | \
 		   MEM_HUGETLB | MEM_HUGETLB_PRIVATE)
 
+#define ALIGN_UP(x, align_to) \
+	((__typeof__(x))((((unsigned long)(x)) + ((align_to)-1)) & ~((align_to)-1)))
+
 struct mem_type {
 	const char *name;
 	unsigned int mem_flag;
@@ -78,6 +81,7 @@ typedef struct {
 	uffd_test_fn uffd_fn;
 	unsigned int mem_targets;
 	uint64_t uffd_feature_required;
+	uffd_test_case_ops_t *test_case_ops;
 } uffd_test_case_t;
 
 static void uffd_test_report(void)
@@ -185,6 +189,7 @@ uffd_setup_environment(uffd_test_args_t *args, uffd_test_case_t *test,
 {
 	map_shared = mem_type->shared;
 	uffd_test_ops = mem_type->mem_ops;
+	uffd_test_case_ops = test->test_case_ops;
 
 	if (mem_type->mem_flag & (MEM_HUGETLB_PRIVATE | MEM_HUGETLB))
 		page_size = default_huge_page_size();
@@ -1062,6 +1067,188 @@ static void uffd_poison_test(uffd_test_args_t *targs)
 	uffd_test_pass();
 }
 
+static void
+uffd_move_handle_fault_common(struct uffd_msg *msg, struct uffd_args *args,
+			      unsigned long len)
+{
+	unsigned long offset;
+
+	if (msg->event != UFFD_EVENT_PAGEFAULT)
+		err("unexpected msg event %u", msg->event);
+
+	if (msg->arg.pagefault.flags &
+	    (UFFD_PAGEFAULT_FLAG_WP | UFFD_PAGEFAULT_FLAG_MINOR | UFFD_PAGEFAULT_FLAG_WRITE))
+		err("unexpected fault type %llu", msg->arg.pagefault.flags);
+
+	offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst;
+	offset &= ~(len-1);
+
+	if (move_page(uffd, offset, len))
+		args->missing_faults++;
+}
+
+static void uffd_move_handle_fault(struct uffd_msg *msg,
+				   struct uffd_args *args)
+{
+	uffd_move_handle_fault_common(msg, args, page_size);
+}
+
+static void uffd_move_pmd_handle_fault(struct uffd_msg *msg,
+				       struct uffd_args *args)
+{
+	uffd_move_handle_fault_common(msg, args, read_pmd_pagesize());
+}
+
+static void
+uffd_move_test_common(uffd_test_args_t *targs, unsigned long chunk_size,
+		      void (*handle_fault)(struct uffd_msg *msg, struct uffd_args *args))
+{
+	unsigned long nr;
+	pthread_t uffd_mon;
+	char c;
+	unsigned long long count;
+	struct uffd_args args = { 0 };
+	char *orig_area_src, *orig_area_dst;
+	unsigned long step_size, step_count;
+	unsigned long src_offs = 0;
+	unsigned long dst_offs = 0;
+
+	/* Prevent source pages from being mapped more than once */
+	if (madvise(area_src, nr_pages * page_size, MADV_DONTFORK))
+		err("madvise(MADV_DONTFORK) failure");
+
+	if (uffd_register(uffd, area_dst, nr_pages * page_size,
+			  true, false, false))
+		err("register failure");
+
+	args.handle_fault = handle_fault;
+	if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args))
+		err("uffd_poll_thread create");
+
+	step_size = chunk_size / page_size;
+	step_count = nr_pages / step_size;
+
+	if (chunk_size > page_size) {
+		char *aligned_src = ALIGN_UP(area_src, chunk_size);
+		char *aligned_dst = ALIGN_UP(area_dst, chunk_size);
+
+		if (aligned_src != area_src || aligned_dst != area_dst) {
+			src_offs = (aligned_src - area_src) / page_size;
+			dst_offs = (aligned_dst - area_dst) / page_size;
+			step_count--;
+		}
+		orig_area_src = area_src;
+		orig_area_dst = area_dst;
+		area_src = aligned_src;
+		area_dst = aligned_dst;
+	}
+
+	/*
+	 * Read each of the pages back using the UFFD-registered mapping. We
+	 * expect that the first time we touch a page, it will result in a missing
+	 * fault. uffd_poll_thread will resolve the fault by moving source
+	 * page to destination.
+	 */
+	for (nr = 0; nr < step_count * step_size; nr += step_size) {
+		unsigned long i;
+
+		/* Check area_src content */
+		for (i = 0; i < step_size; i++) {
+			count = *area_count(area_src, nr + i);
+			if (count != count_verify[src_offs + nr + i])
+				err("nr %lu source memory invalid %llu %llu\n",
+				    nr + i, count, count_verify[src_offs + nr + i]);
+		}
+
+		/* Faulting into area_dst should move the page or the huge page */
+		for (i = 0; i < step_size; i++) {
+			count = *area_count(area_dst, nr + i);
+			if (count != count_verify[dst_offs + nr + i])
+				err("nr %lu memory corruption %llu %llu\n",
+				    nr, count, count_verify[dst_offs + nr + i]);
+		}
+
+		/* Re-check area_src content which should be empty */
+		for (i = 0; i < step_size; i++) {
+			count = *area_count(area_src, nr + i);
+			if (count != 0)
+				err("nr %lu move failed %llu %llu\n",
+				    nr, count, count_verify[src_offs + nr + i]);
+		}
+	}
+	if (step_size > page_size) {
+		area_src = orig_area_src;
+		area_dst = orig_area_dst;
+	}
+
+	if (write(pipefd[1], &c, sizeof(c)) != sizeof(c))
+		err("pipe write");
+	if (pthread_join(uffd_mon, NULL))
+		err("join() failed");
+
+	if (args.missing_faults != step_count || args.minor_faults != 0)
+		uffd_test_fail("stats check error");
+	else
+		uffd_test_pass();
+}
+
+static void uffd_move_test(uffd_test_args_t *targs)
+{
+	uffd_move_test_common(targs, page_size, uffd_move_handle_fault);
+}
+
+static void uffd_move_pmd_test(uffd_test_args_t *targs)
+{
+	if (madvise(area_dst, nr_pages * page_size, MADV_HUGEPAGE))
+		err("madvise(MADV_HUGEPAGE) failure");
+	uffd_move_test_common(targs, read_pmd_pagesize(),
+			      uffd_move_pmd_handle_fault);
+}
+
+static void uffd_move_pmd_split_test(uffd_test_args_t *targs)
+{
+	if (madvise(area_dst, nr_pages * page_size, MADV_NOHUGEPAGE))
+		err("madvise(MADV_NOHUGEPAGE) failure");
+	uffd_move_test_common(targs, read_pmd_pagesize(),
+			      uffd_move_pmd_handle_fault);
+}
+
+static int prevent_hugepages(const char **errmsg)
+{
+	/* This should be done before source area is populated */
+	if (madvise(area_src, nr_pages * page_size, MADV_NOHUGEPAGE)) {
+		/* Ignore only if CONFIG_TRANSPARENT_HUGEPAGE=n */
+		if (errno != EINVAL) {
+			if (errmsg)
+				*errmsg = "madvise(MADV_NOHUGEPAGE) failed";
+			return -errno;
+		}
+	}
+	return 0;
+}
+
+static int request_hugepages(const char **errmsg)
+{
+	/* This should be done before source area is populated */
+	if (madvise(area_src, nr_pages * page_size, MADV_HUGEPAGE)) {
+		if (errmsg) {
+			*errmsg = (errno == EINVAL) ?
+				"CONFIG_TRANSPARENT_HUGEPAGE is not set" :
+				"madvise(MADV_HUGEPAGE) failed";
+		}
+		return -errno;
+	}
+	return 0;
+}
+
+struct uffd_test_case_ops uffd_move_test_case_ops = {
+	.post_alloc = prevent_hugepages,
+};
+
+struct uffd_test_case_ops uffd_move_test_pmd_case_ops = {
+	.post_alloc = request_hugepages,
+};
+
 /*
  * Test the returned uffdio_register.ioctls with different register modes.
  * Note that _UFFDIO_ZEROPAGE is tested separately in the zeropage test.
@@ -1140,6 +1327,27 @@ uffd_test_case_t uffd_tests[] = {
 		.uffd_feature_required = 0,
 	},
 	{
+		.name = "move",
+		.uffd_fn = uffd_move_test,
+		.mem_targets = MEM_ANON,
+		.uffd_feature_required = UFFD_FEATURE_MOVE,
+		.test_case_ops = &uffd_move_test_case_ops,
+	},
+	{
+		.name = "move-pmd",
+		.uffd_fn = uffd_move_pmd_test,
+		.mem_targets = MEM_ANON,
+		.uffd_feature_required = UFFD_FEATURE_MOVE,
+		.test_case_ops = &uffd_move_test_pmd_case_ops,
+	},
+	{
+		.name = "move-pmd-split",
+		.uffd_fn = uffd_move_pmd_split_test,
+		.mem_targets = MEM_ANON,
+		.uffd_feature_required = UFFD_FEATURE_MOVE,
+		.test_case_ops = &uffd_move_test_pmd_case_ops,
+	},
+	{
 		.name = "wp-fork",
 		.uffd_fn = uffd_wp_fork_test,
 		.mem_targets = MEM_ALL,
@@ -1319,6 +1527,7 @@ int main(int argc, char *argv[])
 				continue;
 			}
 			test->uffd_fn(&args);
+			uffd_test_ctx_clear();
 		}
 	}