[PATCH v12 04/27] migration: push Error **errp into vmstate_load()

[Arun Menon]

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

The errors are temporarily reported using warn_report_err().
This is removed in the subsequent patches in this series
when we are actually able to propagate the error to the calling
function.

Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
Signed-off-by: Arun Menon <arme...@redhat.com>
---
 migration/savevm.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 
0c445a957fc99f826e6753ed3795bcdd51f1e3f5..e19156a280c00c5aead9ca84e143e6c7a7de7501
 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -963,14 +963,20 @@ void vmstate_unregister(VMStateIf *obj, const 
VMStateDescription *vmsd,
     }
 }
 
-static int vmstate_load(QEMUFile *f, SaveStateEntry *se)
+static int vmstate_load(QEMUFile *f, SaveStateEntry *se, Error **errp)
 {
+    int ret;
     trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
     if (!se->vmsd) {         /* Old style */
-        return se->ops->load_state(f, se->opaque, se->load_version_id);
+        ret = se->ops->load_state(f, se->opaque, se->load_version_id);
+        if (ret < 0) {
+            error_setg(errp, "Failed to load vmstate version_id: %d, ret: %d",
+                       se->load_version_id, ret);
+        }
+        return ret;
     }
     return vmstate_load_state(f, se->vmsd, se->opaque, se->load_version_id,
-                              &error_fatal);
+                              errp);
 }
 
 static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se,
@@ -2692,6 +2698,7 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
     SaveStateEntry *se;
     char idstr[256];
     int ret;
+    Error *local_err = NULL;
 
     /* Read section start */
     section_id = qemu_get_be32(f);
@@ -2741,10 +2748,11 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t 
type)
         start_ts = qemu_clock_get_us(QEMU_CLOCK_REALTIME);
     }
 
-    ret = vmstate_load(f, se);
+    ret = vmstate_load(f, se, &local_err);
     if (ret < 0) {
         error_report("error while loading state for instance 0x%"PRIx32" of"
                      " device '%s'", instance_id, idstr);
+        warn_report_err(local_err);
         return ret;
     }
 
@@ -2769,6 +2777,7 @@ qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type)
     uint32_t section_id;
     SaveStateEntry *se;
     int ret;
+    Error *local_err = NULL;
 
     section_id = qemu_get_be32(f);
 
@@ -2794,10 +2803,11 @@ qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type)
         start_ts = qemu_clock_get_us(QEMU_CLOCK_REALTIME);
     }
 
-    ret = vmstate_load(f, se);
+    ret = vmstate_load(f, se, &local_err);
     if (ret < 0) {
         error_report("error while loading state section id %d(%s)",
                      section_id, se->idstr);
+        warn_report_err(local_err);
         return ret;
     }
 

-- 
2.50.1