migration: use qemu_file_set_error to pass error codes back to qemu_s…

…avevm_state

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

include/sysemu/sysemu.h

@@ -73,10 +73,10 @@ void do_info_snapshots(Monitor *mon, const QDict *qdict);
 void qemu_announce_self(void);
 
 bool qemu_savevm_state_blocked(Error **errp);
-int qemu_savevm_state_begin(QEMUFile *f,
-                            const MigrationParams *params);
+void qemu_savevm_state_begin(QEMUFile *f,
+                             const MigrationParams *params);
 int qemu_savevm_state_iterate(QEMUFile *f);
-int qemu_savevm_state_complete(QEMUFile *f);
+void qemu_savevm_state_complete(QEMUFile *f);
 void qemu_savevm_state_cancel(void);
 uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
 int qemu_loadvm_state(QEMUFile *f);

savevm.c

@@ -1579,8 +1579,8 @@ bool qemu_savevm_state_blocked(Error **errp)
     return false;
 }
 
-int qemu_savevm_state_begin(QEMUFile *f,
-                            const MigrationParams *params)
+void qemu_savevm_state_begin(QEMUFile *f,
+                             const MigrationParams *params)
 {
     SaveStateEntry *se;
     int ret;
@@ -1620,11 +1620,10 @@ int qemu_savevm_state_begin(QEMUFile *f,
 
         ret = se->ops->save_live_setup(f, se->opaque);
         if (ret < 0) {
-            return ret;
+            qemu_file_set_error(f, ret);
+            break;
         }
     }
-    ret = qemu_file_get_error(f);
-    return ret;
 }
 
 /*
@@ -1658,6 +1657,9 @@ int qemu_savevm_state_iterate(QEMUFile *f)
         ret = se->ops->save_live_iterate(f, se->opaque);
         trace_savevm_section_end(se->section_id);
 
+        if (ret < 0) {
+            qemu_file_set_error(f, ret);
+        }
         if (ret <= 0) {
             /* Do not proceed to the next vmstate before this one reported
                completion of the current stage. This serializes the migration
@@ -1666,14 +1668,10 @@ int qemu_savevm_state_iterate(QEMUFile *f)
             break;
         }
     }
-    if (ret != 0) {
-        return ret;
-    }
-    ret = qemu_file_get_error(f);
     return ret;
 }
 
-int qemu_savevm_state_complete(QEMUFile *f)
+void qemu_savevm_state_complete(QEMUFile *f)
 {
     SaveStateEntry *se;
     int ret;
@@ -1697,7 +1695,8 @@ int qemu_savevm_state_complete(QEMUFile *f)
         ret = se->ops->save_live_complete(f, se->opaque);
         trace_savevm_section_end(se->section_id);
         if (ret < 0) {
-            return ret;
+            qemu_file_set_error(f, ret);
+            return;
         }
     }
 
@@ -1725,8 +1724,6 @@ int qemu_savevm_state_complete(QEMUFile *f)
     }
 
     qemu_put_byte(f, QEMU_VM_EOF);
-
-    return qemu_file_get_error(f);
 }
 
 uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
@@ -1771,26 +1768,21 @@ static int qemu_savevm_state(QEMUFile *f)
         return -EINVAL;
     }
 
-    ret = qemu_savevm_state_begin(f, &params);
-    if (ret < 0)
-        goto out;
-
-    do {
-        ret = qemu_savevm_state_iterate(f);
-        if (ret < 0)
-            goto out;
-    } while (ret == 0);
-
-    ret = qemu_savevm_state_complete(f);
+    qemu_savevm_state_begin(f, &params);
+    while (qemu_file_get_error(f) == 0) {
+        if (qemu_savevm_state_iterate(f) > 0) {
+            break;
+        }
+    }
 
-out:
+    ret = qemu_file_get_error(f);
     if (ret == 0) {
+        qemu_savevm_state_complete(f);
         ret = qemu_file_get_error(f);
     }
     if (ret != 0) {
         qemu_savevm_state_cancel();
     }
-
     return ret;
 }