migration: push Error **errp into loadvm_postcopy_handle_listen()

This is an incremental step in converting vmstate loading
code to report error via Error objects instead of directly
printing it to console/monitor.
It is ensured that loadvm_postcopy_handle_listen() must report an error
in errp, in case of failure.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Arun Menon <armenon@redhat.com>
Tested-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Link: https://lore.kernel.org/r/20250918-propagate_tpm_error-v14-16-36f11a6fb9d3@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

1 files changed, 7 insertions, 10 deletions

diff --git a/migration/savevm.c b/migration/savevm.c
index 38e22b435b..ce88f56498 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2181,15 +2181,16 @@ static void *postcopy_ram_listen_thread(void *opaque)
 }
 
 /* After this message we must be able to immediately receive postcopy data */
-static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
+static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis,
+                                         Error **errp)
 {
     PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING);
-    Error *local_err = NULL;
 
     trace_loadvm_postcopy_handle_listen("enter");
 
     if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) {
-        error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
+        error_setg(errp,
+                   "CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
         return -1;
     }
     if (ps == POSTCOPY_INCOMING_ADVISE) {
@@ -2212,14 +2213,14 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
     if (migrate_postcopy_ram()) {
         if (postcopy_ram_incoming_setup(mis)) {
             postcopy_ram_incoming_cleanup(mis);
+            error_setg(errp, "Failed to setup incoming postcopy RAM blocks");
             return -1;
         }
     }
 
     trace_loadvm_postcopy_handle_listen("after uffd");
 
-    if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, &local_err)) {
-        error_report_err(local_err);
+    if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, errp)) {
         return -1;
     }
 
@@ -2622,11 +2623,7 @@ static int loadvm_process_command(QEMUFile *f, Error **errp)
         return loadvm_postcopy_handle_advise(mis, len, errp);
 
     case MIG_CMD_POSTCOPY_LISTEN:
-        ret = loadvm_postcopy_handle_listen(mis);
-        if (ret < 0) {
-            error_setg(errp, "Failed to load device state command: %d", ret);
-        }
-        return ret;
+        return loadvm_postcopy_handle_listen(mis, errp);
 
     case MIG_CMD_POSTCOPY_RUN:
         ret = loadvm_postcopy_handle_run(mis);