[PULL 02/11] migration: Update error description outside migration.c

[Juan Quintela]

From: Tejus GK <tejus.gk@nutanix.com>

A few code paths exist in the source code,where a migration is
marked as failed via MIGRATION_STATUS_FAILED, but the failure happens
outside of migration.c

In such cases, an error_report() call is made, however the current
MigrationState is never updated with the error description, and hence
clients like libvirt never know the actual reason for the failure.

This patch covers such cases outside of migration.c and updates the
error description at the appropriate places.

Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Tejus GK <tejus.gk@nutanix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231003065538.244752-3-tejus.gk@nutanix.com>
---
 migration/savevm.c  | 17 ++++++++++++++---
 migration/vmstate.c |  7 ++++---
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 1f65294bf4..60eec7c31f 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -979,6 +979,8 @@ static void save_section_footer(QEMUFile *f, SaveStateEntry 
*se)
 static int vmstate_save(QEMUFile *f, SaveStateEntry *se, JSONWriter *vmdesc)
 {
     int ret;
+    Error *local_err = NULL;
+    MigrationState *s = migrate_get_current();
 
     if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
         return 0;
@@ -1002,6 +1004,8 @@ static int vmstate_save(QEMUFile *f, SaveStateEntry *se, 
JSONWriter *vmdesc)
     } else {
         ret = vmstate_save_state_with_err(f, se->vmsd, se->opaque, vmdesc, 
&local_err);
         if (ret) {
+            migrate_set_error(s, local_err);
+            error_report_err(local_err);
             return ret;
         }
     }
@@ -1068,10 +1072,14 @@ void qemu_savevm_send_open_return_path(QEMUFile *f)
 int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len)
 {
     uint32_t tmp;
+    MigrationState *ms = migrate_get_current();
+    Error *local_err = NULL;
 
     if (len > MAX_VM_CMD_PACKAGED_SIZE) {
-        error_report("%s: Unreasonably large packaged state: %zu",
+        error_setg(&local_err, "%s: Unreasonably large packaged state: %zu",
                      __func__, len);
+        migrate_set_error(ms, local_err);
+        error_report_err(local_err);
         return -1;
     }
 
@@ -1499,8 +1507,11 @@ int 
qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
          * bdrv_activate_all() on the other end won't fail. */
         ret = bdrv_inactivate_all();
         if (ret) {
-            error_report("%s: bdrv_inactivate_all() failed (%d)",
-                         __func__, ret);
+            Error *local_err = NULL;
+            error_setg(&local_err, "%s: bdrv_inactivate_all() failed (%d)",
+                       __func__, ret);
+            migrate_set_error(ms, local_err);
+            error_report_err(local_err);
             qemu_file_set_error(f, ret);
             return ret;
         }
diff --git a/migration/vmstate.c b/migration/vmstate.c
index dd9c76dbeb..4cde30bf2d 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -14,6 +14,7 @@
 #include "migration.h"
 #include "migration/vmstate.h"
 #include "savevm.h"
+#include "qapi/error.h"
 #include "qapi/qmp/json-writer.h"
 #include "qemu-file.h"
 #include "qemu/bitops.h"
@@ -336,7 +337,7 @@ int vmstate_save_state_v(QEMUFile *f, const 
VMStateDescription *vmsd,
         ret = vmsd->pre_save(opaque);
         trace_vmstate_save_state_pre_save_res(vmsd->name, ret);
         if (ret) {
-            error_report("pre-save failed: %s", vmsd->name);
+            error_setg(errp, "pre-save failed: %s", vmsd->name);
             return ret;
         }
     }
@@ -389,8 +390,8 @@ int vmstate_save_state_v(QEMUFile *f, const 
VMStateDescription *vmsd,
                                      vmdesc_loop);
                 }
                 if (ret) {
-                    error_report("Save of field %s/%s failed",
-                                 vmsd->name, field->name);
+                    error_setg(errp, "Save of field %s/%s failed",
+                                vmsd->name, field->name);
                     if (vmsd->post_save) {
                         vmsd->post_save(opaque);
                     }
-- 
2.41.0