1 files changed, 52 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/include/userfaultfd_util.h b/tools/testing/selftests/kvm/include/userfaultfd_util.h
new file mode 100644
index 000000000000..60f7f9d435dc
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/userfaultfd_util.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * KVM userfaultfd util
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ * Copyright (C) 2019-2022 Google LLC
+ */
+#include <inttypes.h>
+#include <time.h>
+#include <pthread.h>
+#include <linux/userfaultfd.h>
+
+#include "test_util.h"
+
+typedef int (*uffd_handler_t)(int uffd_mode, int uffd, struct uffd_msg *msg);
+
+struct uffd_reader_args {
+	int uffd_mode;
+	int uffd;
+	useconds_t delay;
+	uffd_handler_t handler;
+	/* Holds the read end of the pipe for killing the reader. */
+	int pipe;
+};
+
+struct uffd_desc {
+	int uffd;
+	uint64_t num_readers;
+	/* Holds the write ends of the pipes for killing the readers. */
+	int *pipefds;
+	pthread_t *readers;
+	struct uffd_reader_args *reader_args;
+};
+
+struct uffd_desc *uffd_setup_demand_paging(int uffd_mode, useconds_t delay,
+					   void *hva, uint64_t len,
+					   uint64_t num_readers,
+					   uffd_handler_t handler);
+
+void uffd_stop_demand_paging(struct uffd_desc *uffd);
+
+#ifdef PRINT_PER_PAGE_UPDATES
+#define PER_PAGE_DEBUG(...) printf(__VA_ARGS__)
+#else
+#define PER_PAGE_DEBUG(...) _no_printf(__VA_ARGS__)
+#endif
+
+#ifdef PRINT_PER_VCPU_UPDATES
+#define PER_VCPU_DEBUG(...) printf(__VA_ARGS__)
+#else
+#define PER_VCPU_DEBUG(...) _no_printf(__VA_ARGS__)
+#endif