[PATCH v11 6/9] migrate: Hack for late migration fixups

[Stefano Brivio <sbrivio@redhat.com>]

From: David Gibson <david@gibson.dropbear.id.au>

Abuse the VHOST_USER_SEND_RARP command to do operations that need to
happen very late on the target side migration.  Nothing is in there now and
with some luck we'll be able to drop this completely before merge.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20250205230919.205302-5-sbrivio@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 migrate.c    | 11 +++++++++++
 migrate.h    |  1 +
 vhost_user.c |  3 +++
 3 files changed, 15 insertions(+)

diff --git a/migrate.c b/migrate.c
index f93cff4..9deee7a 100644
--- a/migrate.c
+++ b/migrate.c
@@ -267,3 +267,14 @@ void migrate_handler(struct ctx *c)
 
 	c->device_state_result = rc;
 }
+
+/**
+ * migrate_finish() - Hack to connect() migrated sockets from "RARP" trigger
+ * @c:		Execution context
+ */
+void migrate_finish(struct ctx *c)
+{
+	(void)c;
+
+	/* HACK RARP: flow_migrate_target_post(c); */
+}
diff --git a/migrate.h b/migrate.h
index a586112..5311f0e 100644
--- a/migrate.h
+++ b/migrate.h
@@ -52,5 +52,6 @@ void migrate_init(struct ctx *c);
 void migrate_close(struct ctx *c);
 void migrate_request(struct ctx *c, int fd, bool target);
 void migrate_handler(struct ctx *c);
+void migrate_finish(struct ctx *c);
 
 #endif /* MIGRATE_H */
diff --git a/vhost_user.c b/vhost_user.c
index 9870a4f..8ce22db 100644
--- a/vhost_user.c
+++ b/vhost_user.c
@@ -995,6 +995,9 @@ static bool vu_send_rarp_exec(struct vu_dev *vdev,
 	      eth_ntop((unsigned char *)&msg->payload.u64, macstr,
 		       sizeof(macstr)));
 
+	/* Abuse this as trigger to finally connect() migrated sockets */
+	migrate_finish(vdev->context);
+
 	return false;
 }
 
-- 
@@ -995,6 +995,9 @@ static bool vu_send_rarp_exec(struct vu_dev *vdev,
 	      eth_ntop((unsigned char *)&msg->payload.u64, macstr,
 		       sizeof(macstr)));
 
+	/* Abuse this as trigger to finally connect() migrated sockets */
+	migrate_finish(vdev->context);
+
 	return false;
 }
 
-- 
2.43.0