yank: Unregister function when using TLS migration

After yank feature was introduced in migration, 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().

Also, inside migration_channel_connect() and
migration_channel_process_incoming() move yank_register_function() so
it only runs once on a TLS migration.

Fixes: b5eea99ec2 ("migration: Add yank feature", 2021-01-13)
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1964326
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Peter Xu <peterx@redhat.com>

--
Changes since v2:
- Dropped all references to ioc->master
- yank_register_function() and yank_unregister_function() now only run
  once in a TLS migration.

Changes since v1:
- Cast p->c to QIOChannelTLS into multifd_load_cleanup()
Message-Id: <20210601054030.1153249-1-leobras.c@gmail.com>

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Leonardo Bras 2021-06-01 02:40:31 -03:00 committed by Dr. David Alan Gilbert
parent a4716fd8d7
commit 7de2e85653
3 changed files with 19 additions and 14 deletions

View file

@ -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"
@ -106,7 +107,8 @@ static int channel_close(void *opaque, Error **errp)
int ret;
QIOChannel *ioc = QIO_CHANNEL(opaque);
ret = qio_channel_close(ioc, errp);
if (object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET)
if ((object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS))
&& OBJECT(ioc)->ref == 1) {
yank_unregister_function(MIGRATION_YANK_INSTANCE,
migration_yank_iochannel,