tests/migration: Setup pre-listened cpr.sock to remove race-condition.
When the source VM attempts to connect to the destination VM's Unix
domain socket (cpr.sock) during a cpr-transfer test, race conditions can
occur if the socket file isn't ready. This can lead to connection
failures when running tests.
This patch creates and listens on the socket in advance, and passes the
pre-listened FD directly. This avoids timing issues and improves the
reliability of CPR tests.
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com>
Reviewed-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/20250611205610.147008-2-jhkim@linux.ibm.com
[peterx: null-initialize opts_target, per Steve]
Signed-off-by: Peter Xu <peterx@redhat.com>
diff --git a/tests/qtest/migration/cpr-tests.c b/tests/qtest/migration/cpr-tests.c
index 5536e14..5e764a6 100644
--- a/tests/qtest/migration/cpr-tests.c
+++ b/tests/qtest/migration/cpr-tests.c
@@ -60,13 +60,12 @@
g_autofree char *cpr_path = g_strdup_printf("%s/cpr.sock", tmpfs);
g_autofree char *mig_path = g_strdup_printf("%s/migsocket", tmpfs);
g_autofree char *uri = g_strdup_printf("unix:%s", mig_path);
+ g_autofree char *opts_target = NULL;
const char *opts = "-machine aux-ram-share=on -nodefaults";
g_autofree const char *cpr_channel = g_strdup_printf(
"cpr,addr.transport=socket,addr.type=unix,addr.path=%s",
cpr_path);
- g_autofree char *opts_target = g_strdup_printf("-incoming %s %s",
- cpr_channel, opts);
g_autofree char *connect_channels = g_strdup_printf(
"[ { 'channel-type': 'main',"
@@ -75,6 +74,17 @@
" 'path': '%s' } } ]",
mig_path);
+ /*
+ * Set up a UNIX domain socket for the CPR channel before
+ * launching the destination VM, to avoid timing issues
+ * during connection setup.
+ */
+ int cpr_sockfd = qtest_socket_server(cpr_path);
+ g_assert(cpr_sockfd >= 0);
+
+ opts_target = g_strdup_printf("-incoming cpr,addr.transport=socket,"
+ "addr.type=fd,addr.str=%d %s",
+ cpr_sockfd, opts);
MigrateCommon args = {
.start.opts_source = opts,
.start.opts_target = opts_target,