4 files changed, 4 insertions, 10 deletions
diff --git a/tools/virtio/linux/kernel.h b/tools/virtio/linux/kernel.h
index 7ef45a4a3cba..6683b4a70b05 100644
--- a/tools/virtio/linux/kernel.h
+++ b/tools/virtio/linux/kernel.h
@@ -127,7 +127,7 @@ static inline void free_page(unsigned long addr)
 #define dev_err(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 #define dev_warn(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 
-#define WARN_ON_ONCE(cond) ((cond) ? fprintf (stderr, "WARNING\n") : 0)
+#define WARN_ON_ONCE(cond) (unlikely(cond) ? fprintf (stderr, "WARNING\n") : 0)
 
 #define min(x, y) ({				\
 	typeof(x) _min1 = (x);			\
diff --git a/tools/virtio/virtio-trace/trace-agent-ctl.c b/tools/virtio/virtio-trace/trace-agent-ctl.c
index a2d0403c4f94..73d253d4b559 100644
--- a/tools/virtio/virtio-trace/trace-agent-ctl.c
+++ b/tools/virtio/virtio-trace/trace-agent-ctl.c
@@ -1,12 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Controller of read/write threads for virtio-trace
  *
  * Copyright (C) 2012 Hitachi, Ltd.
  * Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
  *            Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
- *
- * Licensed under GPL version 2 only.
- *
  */
 
 #define _GNU_SOURCE
diff --git a/tools/virtio/virtio-trace/trace-agent-rw.c b/tools/virtio/virtio-trace/trace-agent-rw.c
index 3aace5ea4842..ddfe7875eb16 100644
--- a/tools/virtio/virtio-trace/trace-agent-rw.c
+++ b/tools/virtio/virtio-trace/trace-agent-rw.c
@@ -1,12 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Read/write thread of a guest agent for virtio-trace
  *
  * Copyright (C) 2012 Hitachi, Ltd.
  * Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
  *            Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
- *
- * Licensed under GPL version 2 only.
- *
  */
 
 #define _GNU_SOURCE
diff --git a/tools/virtio/virtio-trace/trace-agent.c b/tools/virtio/virtio-trace/trace-agent.c
index 0a0a7dd4eff7..cdfe77c2b4c8 100644
--- a/tools/virtio/virtio-trace/trace-agent.c
+++ b/tools/virtio/virtio-trace/trace-agent.c
@@ -1,12 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Guest agent for virtio-trace
  *
  * Copyright (C) 2012 Hitachi, Ltd.
  * Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
  *            Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
- *
- * Licensed under GPL version 2 only.
- *
  */
 
 #define _GNU_SOURCE