[PATCH v4 43/54] tests/qtest: migration-test: Make sure QEMU process "to" exited after migration is canceled

[Bin Meng <bmeng.cn@gmail.com>]

From: Xuzhou Cheng <xuzhou.cheng@windriver.com>

Make sure QEMU process "to" exited before launching another target
for migration in the test_multifd_tcp_cancel case.

Signed-off-by: Xuzhou Cheng <xuzhou.cheng@windriver.com>
Signed-off-by: Bin Meng <bin.meng@windriver.com>
---

(no changes since v3)

Changes in v3:
- Add a usleep(1) in the busy wait loop

Changes in v2:
- Change to a busy wait after migration is canceled

 tests/qtest/migration-test.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 45c5f5761b..6f9fe13488 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -2132,6 +2132,10 @@ static void test_multifd_tcp_cancel(void)
     wait_for_migration_pass(from);
 
     migrate_cancel(from);
+    /* Make sure QEMU process "to" exited */
+    while (qtest_probe_child(to)) {
+        usleep(1);
+    }
 
     args = (MigrateStart){
         .only_target = true,
-- 
2.34.1