diff --git a/qemu/include/qemu/atomic.h b/qemu/include/qemu/atomic.h
index f0fdef11..6fe5a06b 100644
--- a/qemu/include/qemu/atomic.h
+++ b/qemu/include/qemu/atomic.h
@@ -57,6 +57,12 @@ void _ReadWriteBarrier(void);
 /* Weak atomic operations prevent the compiler moving other
  * loads/stores past the atomic operation load/store. However there is
  * no explicit memory barrier for the processor.
+ *
+ * The C11 memory model says that variables that are accessed from
+ * different threads should at least be done with __ATOMIC_RELAXED
+ * primitives or the result is undefined. Generally this has little to
+ * no effect on the generated code but not using the atomic primitives
+ * will get flagged by sanitizers as a violation.
  */
 #define atomic_read(ptr)                          \
     ({                                            \