We're currently leaking the resources of the TLS thread by not joining
it and also overwriting the p->thread pointer altogether.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 migration/multifd.c | 8 +++++++-
 migration/multifd.h | 2 ++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/migration/multifd.c b/migration/multifd.c
index 25cbc6dc6b..b557d046a9 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -524,6 +524,10 @@ void multifd_save_cleanup(void)
     for (i = 0; i < migrate_multifd_channels(); i++) {
         MultiFDSendParams *p = &multifd_send_state->params[i];
 
+        if (p->tls_thread_created) {
+            qemu_thread_join(&p->tls_thread);
+        }
+
         if (p->running) {
             qemu_thread_join(&p->thread);
         }
@@ -827,7 +831,9 @@ static bool multifd_tls_channel_connect(MultiFDSendParams *p,
     trace_multifd_tls_outgoing_handshake_start(ioc, tioc, hostname);
     qio_channel_set_name(QIO_CHANNEL(tioc), "multifd-tls-outgoing");
     p->c = QIO_CHANNEL(tioc);
-    qemu_thread_create(&p->thread, "multifd-tls-handshake-worker",
+
+    p->tls_thread_created = true;
+    qemu_thread_create(&p->tls_thread, "multifd-tls-handshake-worker",
                        multifd_tls_handshake_thread, p,
                        QEMU_THREAD_JOINABLE);
     return true;
diff --git a/migration/multifd.h b/migration/multifd.h
index 35d11f103c..5a69ef40e2 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -73,6 +73,8 @@ typedef struct {
     char *name;
     /* channel thread id */
     QemuThread thread;
+    QemuThread tls_thread;
+    bool tls_thread_created;
     /* communication channel */
     QIOChannel *c;
     /* is the yank function registered */
-- 
2.35.3

On Fri, Feb 02, 2024 at 04:11:24PM -0300, Fabiano Rosas wrote:
> We're currently leaking the resources of the TLS thread by not joining
> it and also overwriting the p->thread pointer altogether.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Reviewed-by: Peter Xu <peterx@redhat.com>

Does this deserve below?

Fixes: a1af605bd5 ("migration/multifd: fix hangup with TLS-Multifd due to blocking handshake")
Cc: qemu-stable <qemu-stable@nongnu.org>

-- 
Peter Xu