[PATCH v4 03/23] migration: push Error **errp into qemu_loadvm_state_header()

[Arun Menon <armenon@redhat.com>]

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.

Signed-off-by: Arun Menon <armenon@redhat.com>
---
 migration/savevm.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index ab947620f724874f325fb9fb59bef50b7c16fb51..3ccbc724eb808db09b77088a858ecc7f06b21155 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2814,35 +2814,42 @@ 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;
 
     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-        error_report("SaveVM v2 format is obsolete and don't work anymore");
+        error_setg(errp, "SaveVM v2 format is obsolete and don't "
+                   "work anymore, file version %x != %x",
+                   v, QEMU_VM_FILE_VERSION_COMPAT);
+
         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,
-                                 NULL);
 
+        ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0,
+                                 errp);
         if (ret) {
             return ret;
         }
@@ -3119,7 +3126,7 @@ int qemu_loadvm_state(QEMUFile *f)
 
     qemu_loadvm_thread_pool_create(mis);
 
-    ret = qemu_loadvm_state_header(f);
+    ret = qemu_loadvm_state_header(f, NULL);
     if (ret) {
         return ret;
     }

-- 
2.50.0