2 files changed, 25 insertions, 0 deletions
diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h
index 0fefbc6..9a8438f 100644
--- a/include/qemu/plugin.h
+++ b/include/qemu/plugin.h
@@ -190,6 +190,16 @@ void qemu_plugin_add_dyn_cb_arr(GArray *arr);
 
 void qemu_plugin_disable_mem_helpers(CPUState *cpu);
 
+/**
+ * qemu_plugin_user_exit(): clean-up callbacks before calling exit callbacks
+ *
+ * This is a user-mode only helper that ensure we have fully cleared
+ * callbacks from all threads before calling the exit callbacks. This
+ * is so the plugins themselves don't have to jump through hoops to
+ * guard against race conditions.
+ */
+void qemu_plugin_user_exit(void);
+
 #else /* !CONFIG_PLUGIN */
 
 static inline void qemu_plugin_add_opts(void)
@@ -250,6 +260,8 @@ void qemu_plugin_add_dyn_cb_arr(GArray *arr)
 static inline void qemu_plugin_disable_mem_helpers(CPUState *cpu)
 { }
 
+static inline void qemu_plugin_user_exit(void)
+{ }
 #endif /* !CONFIG_PLUGIN */
 
 #endif /* QEMU_PLUGIN_H */
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index dc3496f..e6e815a 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -549,6 +549,19 @@ void qemu_plugin_vcpu_for_each(qemu_plugin_id_t id,
 void qemu_plugin_register_flush_cb(qemu_plugin_id_t id,
                                    qemu_plugin_simple_cb_t cb);
 
+/**
+ * qemu_plugin_register_atexit_cb() - register exit callback
+ * @id: plugin ID
+ * @cb: callback
+ * @userdata: user data for callback
+ *
+ * The @cb function is called once execution has finished. Plugins
+ * should be able to free all their resources at this point much like
+ * after a reset/uninstall callback is called.
+ *
+ * In user-mode it is possible a few un-instrumented instructions from
+ * child threads may run before the host kernel reaps the threads.
+ */
 void qemu_plugin_register_atexit_cb(qemu_plugin_id_t id,
                                     qemu_plugin_udata_cb_t cb, void *userdata);