hw/core/reset: Add qemu_{register, unregister}_resettable()

Implement new functions qemu_register_resettable() and
qemu_unregister_resettable().  These are intended to be
three-phase-reset aware equivalents of the old qemu_register_reset()
and qemu_unregister_reset().  Instead of passing in a function
pointer and opaque, you register any QOM object that implements the
Resettable interface.

The implementation is simple: we have a single global instance of a
ResettableContainer, which we reset in qemu_devices_reset(), and
the Resettable objects passed to qemu_register_resettable() are
added to it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20240220160622.114437-8-peter.maydell@linaro.org
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>

1 files changed, 29 insertions, 2 deletions

diff --git a/hw/core/reset.c b/hw/core/reset.c
index d3263b613e..a9b30e705f 100644
--- a/hw/core/reset.c
+++ b/hw/core/reset.c
@@ -26,8 +26,23 @@
 #include "qemu/osdep.h"
 #include "qemu/queue.h"
 #include "sysemu/reset.h"
+#include "hw/resettable.h"
+#include "hw/core/resetcontainer.h"
 
-/* reset/shutdown handler */
+/*
+ * Return a pointer to the singleton container that holds all the Resettable
+ * items that will be reset when qemu_devices_reset() is called.
+ */
+static ResettableContainer *get_root_reset_container(void)
+{
+    static ResettableContainer *root_reset_container;
+
+    if (!root_reset_container) {
+        root_reset_container =
+            RESETTABLE_CONTAINER(object_new(TYPE_RESETTABLE_CONTAINER));
+    }
+    return root_reset_container;
+}
 
 typedef struct QEMUResetEntry {
     QTAILQ_ENTRY(QEMUResetEntry) entry;
@@ -71,6 +86,16 @@ void qemu_unregister_reset(QEMUResetHandler *func, void *opaque)
     }
 }
 
+void qemu_register_resettable(Object *obj)
+{
+    resettable_container_add(get_root_reset_container(), obj);
+}
+
+void qemu_unregister_resettable(Object *obj)
+{
+    resettable_container_remove(get_root_reset_container(), obj);
+}
+
 void qemu_devices_reset(ShutdownCause reason)
 {
     QEMUResetEntry *re, *nre;
@@ -83,5 +108,7 @@ void qemu_devices_reset(ShutdownCause reason)
         }
         re->func(re->opaque);
     }
-}
 
+    /* Reset the simulation */
+    resettable_reset(OBJECT(get_root_reset_container()), RESET_TYPE_COLD);
+}