hw/core/qdev: update hotplug reset regarding resettable

This commit make use of the resettable API to reset the device being
hotplugged when it is realized. Also it ensures it is put in a reset
state coherent with the parent it is plugged into.

Note that there is a difference in the reset. Instead of resetting
only the hotplugged device, we reset also its subtree (switch to
resettable API). This is not expected to be a problem because
sub-buses are just realized too. If a hotplugged device has any
sub-buses it is logical to reset them too at this point.

The recently added should_be_hidden and PCI's partially_hotplugged
mechanisms do not interfere with realize operation:
+ In the should_be_hidden use case, device creation is
delayed.
+ The partially_hotplugged mechanism prevents a device to be
unplugged and unrealized from qdev POV and unrealized.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-8-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 28fc93b107..7697f033b1 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -909,6 +909,12 @@ static void device_set_realized(Object *obj, bool value, Error **errp)
             }
         }
 
+        /*
+         * Clear the reset state, in case the object was previously unrealized
+         * with a dirty state.
+         */
+        resettable_state_clear(&dev->reset);
+
         QLIST_FOREACH(bus, &dev->child_bus, sibling) {
             object_property_set_bool(OBJECT(bus), true, "realized",
                                          &local_err);
@@ -917,7 +923,14 @@ static void device_set_realized(Object *obj, bool value, Error **errp)
             }
         }
         if (dev->hotplugged) {
-            device_legacy_reset(dev);
+            /*
+             * Reset the device, as well as its subtree which, at this point,
+             * should be realized too.
+             */
+            resettable_assert_reset(OBJECT(dev), RESET_TYPE_COLD);
+            resettable_change_parent(OBJECT(dev), OBJECT(dev->parent_bus),
+                                     NULL);
+            resettable_release_reset(OBJECT(dev), RESET_TYPE_COLD);
         }
         dev->pending_deleted_event = false;