tests/migration-test: Remove postcopy_data from MigrateCommon

Now postcopy is not the only user of start_hook / end_hook that will pass
in a opaque pointer.  It doesn't need to be defined in MigrateCommon as
part of the framework, as all other hook users can pass hook_data around.
Do it too for postcopy.

Reviewed-by: Prasad Pandit <ppandit@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20260114153751.2427172-2-peterx@redhat.com
Signed-off-by: Fabiano Rosas <farosas@suse.de>

tests/qtest/migration/framework.c

@@ -541,6 +541,7 @@ void migrate_end(QTestState *from, QTestState *to, bool test_dest)
 
 static int migrate_postcopy_prepare(QTestState **from_ptr,
                                     QTestState **to_ptr,
+                                    void **hook_data,
                                     MigrateCommon *args)
 {
     QTestState *from, *to;
@@ -554,7 +555,7 @@ static int migrate_postcopy_prepare(QTestState **from_ptr,
     }
 
     if (args->start_hook) {
-        args->postcopy_data = args->start_hook(from, to);
+        *hook_data = args->start_hook(from, to);
     }
 
     migrate_ensure_non_converge(from);
@@ -582,7 +583,7 @@ static int migrate_postcopy_prepare(QTestState **from_ptr,
 }
 
 static void migrate_postcopy_complete(QTestState *from, QTestState *to,
-                                      MigrateCommon *args)
+                                      void *hook_data, MigrateCommon *args)
 {
     MigrationTestEnv *env = migration_get_env();
 
@@ -601,8 +602,7 @@ static void migrate_postcopy_complete(QTestState *from, QTestState *to,
     }
 
     if (args->end_hook) {
-        args->end_hook(from, to, args->postcopy_data);
+        args->end_hook(from, to, hook_data);
-        args->postcopy_data = NULL;
     }
 
     migrate_end(from, to, true);
@@ -610,13 +610,14 @@ static void migrate_postcopy_complete(QTestState *from, QTestState *to,
 
 void test_postcopy_common(MigrateCommon *args)
 {
+    void *hook_data = NULL;
     QTestState *from, *to;
 
-    if (migrate_postcopy_prepare(&from, &to, args)) {
+    if (migrate_postcopy_prepare(&from, &to, &hook_data, args)) {
         return;
     }
     migrate_postcopy_start(from, to, &src_state);
-    migrate_postcopy_complete(from, to, args);
+    migrate_postcopy_complete(from, to, hook_data, args);
 }
 
 static void wait_for_postcopy_status(QTestState *one, const char *status)
@@ -742,6 +743,7 @@ void test_postcopy_recovery_common(MigrateCommon *args)
 {
     QTestState *from, *to;
     g_autofree char *uri = NULL;
+    void *hook_data = NULL;
 
     /*
      * Always enable OOB QMP capability for recovery tests, migrate-recover is
@@ -752,7 +754,7 @@ void test_postcopy_recovery_common(MigrateCommon *args)
     /* Always hide errors for postcopy recover tests since they're expected */
     args->start.hide_stderr = true;
 
-    if (migrate_postcopy_prepare(&from, &to, args)) {
+    if (migrate_postcopy_prepare(&from, &to, &hook_data, args)) {
         return;
     }
 
@@ -808,7 +810,7 @@ void test_postcopy_recovery_common(MigrateCommon *args)
     /* Restore the postcopy bandwidth to unlimited */
     migrate_set_parameter_int(from, "max-postcopy-bandwidth", 0);
 
-    migrate_postcopy_complete(from, to, args);
+    migrate_postcopy_complete(from, to, hook_data, args);
 }
 
 int test_precopy_common(MigrateCommon *args)

tests/qtest/migration/framework.h

@@ -231,7 +231,6 @@ typedef struct {
     bool live;
 
     /* Postcopy specific fields */
-    void *postcopy_data;
     PostcopyRecoveryFailStage postcopy_recovery_fail_stage;
 } MigrateCommon;