[v2,07/12] savevm: update error reporting for qemu_loadvm_state()

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index f46f9d2..70c6927 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -78,7 +78,7 @@  int qemu_savevm_state_iterate(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);
+void qemu_loadvm_state(QEMUFile *f, Error **errp);
 
 /* SLIRP */
 void do_info_slirp(Monitor *mon);
diff --git a/migration.c b/migration.c
index 3eb0fad..0279911 100644
--- a/migration.c
+++ b/migration.c
@@ -93,12 +93,15 @@  void qemu_start_incoming_migration(const char *uri, Error **errp)
 static void process_incoming_migration_co(void *opaque)
 {
     QEMUFile *f = opaque;
-    int ret;
+    Error *local_err = NULL;
 
-    ret = qemu_loadvm_state(f);
+    qemu_loadvm_state(f, &local_err);
     qemu_fclose(f);
-    if (ret < 0) {
-        fprintf(stderr, "load of migration failed\n");
+    if (error_is_set(&local_err)) {
+        qerror_report(ERROR_CLASS_GENERIC_ERROR,
+                      "Incoming migration failed: %s",
+                      error_get_pretty(local_err));
+        error_free(local_err);
         exit(EXIT_FAILURE);
     }
     qemu_announce_self();
diff --git a/savevm.c b/savevm.c
index 25fc7cc..54eb61c 100644
--- a/savevm.c
+++ b/savevm.c
@@ -2144,7 +2144,7 @@  typedef struct LoadStateEntry {
     int version_id;
 } LoadStateEntry;
 
-int qemu_loadvm_state(QEMUFile *f)
+void qemu_loadvm_state(QEMUFile *f, Error **errp)
 {
     QLIST_HEAD(, LoadStateEntry) loadvm_handlers =
         QLIST_HEAD_INITIALIZER(loadvm_handlers);
@@ -2153,21 +2153,26 @@  int qemu_loadvm_state(QEMUFile *f)
     unsigned int v;
     int ret;
 
-    if (qemu_savevm_state_blocked(NULL)) {
-        return -EINVAL;
+    if (qemu_savevm_state_blocked(errp)) {
+        return;
     }
 
     v = qemu_get_be32(f);
-    if (v != QEMU_VM_FILE_MAGIC)
-        return -EINVAL;
+    if (v != QEMU_VM_FILE_MAGIC) {
+        error_setg(errp, "Unknown vmstate file magic");
+        return;
+    }
 
     v = qemu_get_be32(f);
     if (v == QEMU_VM_FILE_VERSION_COMPAT) {
-        fprintf(stderr, "SaveVM v2 format is obsolete and don't work anymore\n");
-        return -ENOTSUP;
+        error_setg(errp, "vmstate v2 format is obsolete and doesn't work "
+                   "anymore");
+        return;
+    }
+    if (v != QEMU_VM_FILE_VERSION) {
+        error_setg(errp, "Unknown vmstate file version");
+        return;
     }
-    if (v != QEMU_VM_FILE_VERSION)
-        return -ENOTSUP;
 
     while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
         uint32_t instance_id, version_id, section_id;
@@ -2189,16 +2194,15 @@  int qemu_loadvm_state(QEMUFile *f)
             /* Find savevm section */
             se = find_se(idstr, instance_id);
             if (se == NULL) {
-                fprintf(stderr, "Unknown savevm section or instance '%s' %d\n", idstr, instance_id);
-                ret = -EINVAL;
+                error_setg(errp, "Unknown vmstate section or instance '%s' %d",
+                           idstr, instance_id);
                 goto out;
             }
 
             /* Validate version */
             if (version_id > se->version_id) {
-                fprintf(stderr, "savevm: unsupported version %d for '%s' v%d\n",
-                        version_id, idstr, se->version_id);
-                ret = -EINVAL;
+                error_setg(errp, "Unsupported version %d for '%s' v%d",
+                           version_id, idstr, se->version_id);
                 goto out;
             }
 
@@ -2212,8 +2216,8 @@  int qemu_loadvm_state(QEMUFile *f)
 
             ret = vmstate_load(f, le->se, le->version_id);
             if (ret < 0) {
-                fprintf(stderr, "qemu: warning: error while loading state for instance 0x%x of device '%s'\n",
-                        instance_id, idstr);
+                error_setg(errp, "Error while loading state for instance "
+                           "0x%x of device '%s'", instance_id, idstr);
                 goto out;
             }
             break;
@@ -2227,40 +2231,35 @@  int qemu_loadvm_state(QEMUFile *f)
                 }
             }
             if (le == NULL) {
-                fprintf(stderr, "Unknown savevm section %d\n", section_id);
-                ret = -EINVAL;
+                error_setg(errp, "Unknown vmstate section %d", section_id);
                 goto out;
             }
 
             ret = vmstate_load(f, le->se, le->version_id);
             if (ret < 0) {
-                fprintf(stderr, "qemu: warning: error while loading state section id %d\n",
+                error_setg(errp, "Error while loading state section id %d",
                         section_id);
                 goto out;
             }
             break;
         default:
-            fprintf(stderr, "Unknown savevm section type %d\n", section_type);
-            ret = -EINVAL;
+            error_setg(errp, "Unknown vmstate section type %d", section_type);
             goto out;
         }
     }
 
     cpu_synchronize_all_post_init();
 
-    ret = 0;
+    ret = qemu_file_get_error(f);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Failed to load vmstate");
+    }
 
 out:
     QLIST_FOREACH_SAFE(le, &loadvm_handlers, entry, new_le) {
         QLIST_REMOVE(le, entry);
         g_free(le);
     }
-
-    if (ret == 0) {
-        ret = qemu_file_get_error(f);
-    }
-
-    return ret;
 }
 
 static bool bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
@@ -2482,7 +2481,6 @@  int load_vmstate(const char *name)
     QEMUSnapshotInfo sn;
     QEMUFile *f;
     Error *local_err = NULL;
-    int ret;
 
     bs_vm_state = bdrv_snapshots();
     if (!bs_vm_state) {
@@ -2547,12 +2545,13 @@  int load_vmstate(const char *name)
     }
 
     qemu_system_reset(VMRESET_SILENT);
-    ret = qemu_loadvm_state(f);
+    qemu_loadvm_state(f, &local_err);
 
     qemu_fclose(f);
-    if (ret < 0) {
-        error_report("Error %d while loading VM state", ret);
-        return ret;
+    if (error_is_set(&local_err)) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        return -1;
     }
 
     return 0;