migration: Update error description outside migration.c

A few code paths exist in the source code,where a migration is
marked as failed via MIGRATION_STATUS_FAILED, but the failure happens
outside	of migration.c

In such	cases, an error_report() call is made, however the current
MigrationState is never	updated	with the error description, and	hence
clients	like libvirt never know	the actual reason for the failure.

This patch covers such cases outside of	migration.c and	updates	the
error description at the appropriate places.

Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Tejus GK <tejus.gk@nutanix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231003065538.244752-3-tejus.gk@nutanix.com>

1 files changed, 14 insertions, 3 deletions

diff --git a/migration/savevm.c b/migration/savevm.c
index 1f65294bf4..60eec7c31f 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -979,6 +979,8 @@ static void save_section_footer(QEMUFile *f, SaveStateEntry *se)
 static int vmstate_save(QEMUFile *f, SaveStateEntry *se, JSONWriter *vmdesc)
 {
     int ret;
+    Error *local_err = NULL;
+    MigrationState *s = migrate_get_current();
 
     if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
         return 0;
@@ -1002,6 +1004,8 @@ static int vmstate_save(QEMUFile *f, SaveStateEntry *se, JSONWriter *vmdesc)
     } else {
         ret = vmstate_save_state_with_err(f, se->vmsd, se->opaque, vmdesc, &local_err);
         if (ret) {
+            migrate_set_error(s, local_err);
+            error_report_err(local_err);
             return ret;
         }
     }
@@ -1068,10 +1072,14 @@ void qemu_savevm_send_open_return_path(QEMUFile *f)
 int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len)
 {
     uint32_t tmp;
+    MigrationState *ms = migrate_get_current();
+    Error *local_err = NULL;
 
     if (len > MAX_VM_CMD_PACKAGED_SIZE) {
-        error_report("%s: Unreasonably large packaged state: %zu",
+        error_setg(&local_err, "%s: Unreasonably large packaged state: %zu",
                      __func__, len);
+        migrate_set_error(ms, local_err);
+        error_report_err(local_err);
         return -1;
     }
 
@@ -1499,8 +1507,11 @@ int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
          * bdrv_activate_all() on the other end won't fail. */
         ret = bdrv_inactivate_all();
         if (ret) {
-            error_report("%s: bdrv_inactivate_all() failed (%d)",
-                         __func__, ret);
+            Error *local_err = NULL;
+            error_setg(&local_err, "%s: bdrv_inactivate_all() failed (%d)",
+                       __func__, ret);
+            migrate_set_error(ms, local_err);
+            error_report_err(local_err);
             qemu_file_set_error(f, ret);
             return ret;
         }