[PULL 25/30] qapi: Include qom-path in MEMORY_DEVICE_SIZE_CHANGE qapi events

[Paolo Bonzini <pbonzini@redhat.com>]

From: David Hildenbrand <david@redhat.com>

As we might not always have a device id, it is impossible to always
match MEMORY_DEVICE_SIZE_CHANGE events to an actual device. Let's
include the qom-path in the event, which allows for reliable mapping of
events to devices.

Fixes: 722a3c783ef4 ("virtio-pci: Send qapi events when the virtio-mem size changes")
Suggested-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210929162445.64060-3-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/virtio/virtio-mem-pci.c | 5 ++++-
 qapi/machine.json          | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/virtio-mem-pci.c b/hw/virtio/virtio-mem-pci.c
index 7e384b7397..be2383b0c5 100644
--- a/hw/virtio/virtio-mem-pci.c
+++ b/hw/virtio/virtio-mem-pci.c
@@ -87,9 +87,12 @@ static void virtio_mem_pci_size_change_notify(Notifier *notifier, void *data)
     VirtIOMEMPCI *pci_mem = container_of(notifier, VirtIOMEMPCI,
                                          size_change_notifier);
     DeviceState *dev = DEVICE(pci_mem);
+    char *qom_path = object_get_canonical_path(OBJECT(dev));
     const uint64_t * const size_p = data;
 
-    qapi_event_send_memory_device_size_change(!!dev->id, dev->id, *size_p);
+    qapi_event_send_memory_device_size_change(!!dev->id, dev->id, *size_p,
+                                              qom_path);
+    g_free(qom_path);
 }
 
 static void virtio_mem_pci_class_init(ObjectClass *klass, void *data)
diff --git a/qapi/machine.json b/qapi/machine.json
index 0e91a57a76..5db54df298 100644
--- a/qapi/machine.json
+++ b/qapi/machine.json
@@ -1336,8 +1336,11 @@
 # action).
 #
 # @id: device's ID
+#
 # @size: the new size of memory that the device provides
 #
+# @qom-path: path to the device object in the QOM tree (since 6.2)
+#
 # Note: this event is rate-limited.
 #
 # Since: 5.1
@@ -1350,7 +1353,7 @@
 #
 ##
 { 'event': 'MEMORY_DEVICE_SIZE_CHANGE',
-  'data': { '*id': 'str', 'size': 'size' } }
+  'data': { '*id': 'str', 'size': 'size', 'qom-path' : 'str'} }
 
 
 ##
-- 
2.31.1