diff --git a/migration/tls.c b/migration/tls.c
index fa03d9136ca3201ee362e54333037e6740f9f2dc..bf2b67b52ce26a0767cd85d36e03a444f560437b 100644
--- a/migration/tls.c
+++ b/migration/tls.c
@@ -90,6 +90,10 @@ void migration_tls_channel_process_incoming(MigrationState *s,
 
     trace_migration_tls_incoming_handshake_start();
     qio_channel_set_name(QIO_CHANNEL(tioc), "migration-tls-incoming");
+    if (migrate_postcopy_ram() || migrate_return_path()) {
+        qio_channel_set_feature(QIO_CHANNEL(tioc),
+                                QIO_CHANNEL_FEATURE_CONCURRENT_IO);
+    }
     qio_channel_tls_handshake(tioc,
                               migration_tls_incoming_handshake,
                               NULL,
@@ -149,6 +153,10 @@ void migration_tls_channel_connect(MigrationState *s,
     s->hostname = g_strdup(hostname);
     trace_migration_tls_outgoing_handshake_start(hostname);
     qio_channel_set_name(QIO_CHANNEL(tioc), "migration-tls-outgoing");
+    if (migrate_postcopy_ram() || migrate_return_path()) {
+        qio_channel_set_feature(QIO_CHANNEL(tioc),
+                                QIO_CHANNEL_FEATURE_CONCURRENT_IO);
+    }
     qio_channel_tls_handshake(tioc,
                               migration_tls_outgoing_handshake,
                               s,
diff --git a/qemu-img.c b/qemu-img.c
index 49d914c9c4f7ca8fe4a0a0a7bdf4282bc3cabdd8..ae6efb0e0925e9c01b94385015910a89a05b9eaf 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -4522,7 +4522,12 @@ static void bench_cb(void *opaque, int ret)
          */
         b->in_flight++;
         b->offset += b->step;
-        b->offset %= b->image_size;
+        if (b->image_size == 0) {
+            b->offset = 0;
+        } else {
+            b->offset %= b->image_size;
+        }
+
         if (b->write) {
             acb = blk_aio_pwritev(b->blk, offset, b->qiov, 0, bench_cb, b);
         } else {