On 6/10/2025 12:05 PM, Daniel P. Berrangé wrote:
On Tue, Jun 10, 2025 at 10:08:49AM -0500, Jaehoon Kim wrote:
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<jjhe...@linux.ibm.com>
Signed-off-by: Jaehoon Kim<jh...@linux.ibm.com>
---
Changes since v1:
- In v1, the patch added a wait loop to poll the existence of the socket
file (cpr_validate_socket_path()).
- This version instead creates the socket beforehand and passes its FD
to the destination QEMU, eliminating the race condition entirely.
- Commit title and message changed accordingly.
---
migration/cpr-transfer.c | 3 +-
tests/qtest/migration/cpr-tests.c | 72 ++++++++++++++++++++++++++++++-
2 files changed, 72 insertions(+), 3 deletions(-)
diff --git a/migration/cpr-transfer.c b/migration/cpr-transfer.c
index e1f140359c..7c9de70bad 100644
--- a/migration/cpr-transfer.c
+++ b/migration/cpr-transfer.c
@@ -46,7 +46,8 @@ QEMUFile *cpr_transfer_input(MigrationChannel *channel, Error
**errp)
MigrationAddress *addr = channel->addr;
if (addr->transport == MIGRATION_ADDRESS_TYPE_SOCKET &&
- addr->u.socket.type == SOCKET_ADDRESS_TYPE_UNIX) {
+ (addr->u.socket.type == SOCKET_ADDRESS_TYPE_UNIX ||
+ addr->u.socket.type == SOCKET_ADDRESS_TYPE_FD)) {
g_autoptr(QIOChannelSocket) sioc = NULL;
SocketAddress *saddr = &addr->u.socket;
This will likely cause a crash in tracing code that is below this diff:
trace_cpr_transfer_input(addr->u.socket.u.q_unix.path);
q_unix.path is NOT valid to access with TYPE_FD.
With regards,
Daniel
You're right, I should split trace_cpr_transfer_input() call based on
addr->u.socket.type,
since q_unix.path is not valid when the type is TYPE_FD.
- Jaehoon Kim.
