migration: push Error **errp into qemu_loadvm_state_header()

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 qemu_loadvm_state_header() must report an error
in errp, in case of failure.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@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-v14-3-36f11a6fb9d3@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

1 files changed, 17 insertions, 11 deletions

diff --git a/migration/savevm.c b/migration/savevm.c
index 55c99e0902..8ac3d33814 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2814,38 +2814,43 @@ qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type)
     return 0;
 }
 
-static int qemu_loadvm_state_header(QEMUFile *f)
+static int qemu_loadvm_state_header(QEMUFile *f, Error **errp)
 {
     unsigned int v;
     int ret;
-    Error *local_err = NULL;
 
     v = qemu_get_be32(f);
     if (v != QEMU_VM_FILE_MAGIC) {
-        error_report("Not a migration stream");
+        error_setg(errp, "Not a migration stream, magic: %x != %x",
+                   v, QEMU_VM_FILE_MAGIC);
         return -EINVAL;
     }
 
     v = qemu_get_be32(f);
     if (v == QEMU_VM_FILE_VERSION_COMPAT) {
-        error_report("SaveVM v2 format is obsolete and don't work anymore");
+        error_setg(errp,
+                   "SaveVM v2 format is obsolete and no longer supported");
+
         return -ENOTSUP;
     }
     if (v != QEMU_VM_FILE_VERSION) {
-        error_report("Unsupported migration stream version");
+        error_setg(errp, "Unsupported migration stream version, "
+                   "file version %x != %x",
+                   v, QEMU_VM_FILE_VERSION);
         return -ENOTSUP;
     }
 
     if (migrate_get_current()->send_configuration) {
-        if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
-            error_report("Configuration section missing");
+        v = qemu_get_byte(f);
+        if (v != QEMU_VM_CONFIGURATION) {
+            error_setg(errp, "Configuration section missing, %x != %x",
+                       v, QEMU_VM_CONFIGURATION);
             return -EINVAL;
         }
-        ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0,
-                                 &local_err);
 
+        ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0,
+                                 errp);
         if (ret) {
-            error_report_err(local_err);
             return ret;
         }
     }
@@ -3121,8 +3126,9 @@ int qemu_loadvm_state(QEMUFile *f)
 
     qemu_loadvm_thread_pool_create(mis);
 
-    ret = qemu_loadvm_state_header(f);
+    ret = qemu_loadvm_state_header(f, &local_err);
     if (ret) {
+        error_report_err(local_err);
         return ret;
     }