[PATCH v2 1/1] yank: Unregister function when using TLS migration

[Leonardo Bras]

After yank feature was introduced, whenever migration is started using TLS,
the following error happens in both source and destination hosts:

(qemu) qemu-kvm: ../util/yank.c:107: yank_unregister_instance:
Assertion `QLIST_EMPTY(&entry->yankfns)' failed.

This happens because of a missing yank_unregister_function() when using
qio-channel-tls.

Fix this by also allowing TYPE_QIO_CHANNEL_TLS object type to perform
yank_unregister_function() in channel_close() and multifd_load_cleanup().

Fixes: 50186051f ("Introduce yank feature")
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1964326
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>

--
Changes since v1:
- Cast p->c to QIOChannelTLS into multifd_load_cleanup()
---
 migration/multifd.c           | 6 ++++++
 migration/qemu-file-channel.c | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/migration/multifd.c b/migration/multifd.c
index 0a4803cfcc..81de11c6fc 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -992,6 +992,12 @@ int multifd_load_cleanup(Error **errp)
             yank_unregister_function(MIGRATION_YANK_INSTANCE,
                                      migration_yank_iochannel,
                                      QIO_CHANNEL(p->c));
+        } else if (object_dynamic_cast(OBJECT(p->c), TYPE_QIO_CHANNEL_TLS)
+                   && OBJECT(p->c)->ref == 1) {
+            QIOChannelTLS *tioc = QIO_CHANNEL_TLS(p->c);
+            yank_unregister_function(MIGRATION_YANK_INSTANCE,
+                                     migration_yank_iochannel,
+                                     QIO_CHANNEL(tioc->master));
         }
 
         object_unref(OBJECT(p->c));
diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c
index 876d05a540..4f79090f3f 100644
--- a/migration/qemu-file-channel.c
+++ b/migration/qemu-file-channel.c
@@ -26,6 +26,7 @@
 #include "qemu-file-channel.h"
 #include "qemu-file.h"
 #include "io/channel-socket.h"
+#include "io/channel-tls.h"
 #include "qemu/iov.h"
 #include "qemu/yank.h"
 #include "yank_functions.h"
@@ -111,6 +112,12 @@ static int channel_close(void *opaque, Error **errp)
         yank_unregister_function(MIGRATION_YANK_INSTANCE,
                                  migration_yank_iochannel,
                                  QIO_CHANNEL(ioc));
+    } else if (object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS)
+               && OBJECT(ioc)->ref == 1) {
+        QIOChannelTLS *tioc = opaque;
+        yank_unregister_function(MIGRATION_YANK_INSTANCE,
+                                 migration_yank_iochannel,
+                                 QIO_CHANNEL(tioc->master));
     }
     object_unref(OBJECT(ioc));
     return ret;
-- 
2.31.1