migration: push Error **errp into vmstate_load_state()

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

The errors are temporarily reported using error_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 using errp. Whereas, if we want the function to exit on
error, then error_fatal is passed.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
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-v14-2-36f11a6fb9d3@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

1 files changed, 17 insertions, 11 deletions

diff --git a/migration/vmstate-types.c b/migration/vmstate-types.c
index 741a588b7e..c5cfd861e3 100644
--- a/migration/vmstate-types.c
+++ b/migration/vmstate-types.c
@@ -19,6 +19,7 @@
 #include "qemu/error-report.h"
 #include "qemu/queue.h"
 #include "trace.h"
+#include "qapi/error.h"
 
 /* bool */
 
@@ -543,13 +544,17 @@ static int get_tmp(QEMUFile *f, void *pv, size_t size,
                    const VMStateField *field)
 {
     int ret;
+    Error *local_err = NULL;
     const VMStateDescription *vmsd = field->vmsd;
     int version_id = field->version_id;
     void *tmp = g_malloc(size);
 
     /* Writes the parent field which is at the start of the tmp */
     *(void **)tmp = pv;
-    ret = vmstate_load_state(f, vmsd, tmp, version_id);
+    ret = vmstate_load_state(f, vmsd, tmp, version_id, &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     g_free(tmp);
     return ret;
 }
@@ -626,6 +631,7 @@ static int get_qtailq(QEMUFile *f, void *pv, size_t unused_size,
                       const VMStateField *field)
 {
     int ret = 0;
+    Error *local_err = NULL;
     const VMStateDescription *vmsd = field->vmsd;
     /* size of a QTAILQ element */
     size_t size = field->size;
@@ -649,8 +655,9 @@ static int get_qtailq(QEMUFile *f, void *pv, size_t unused_size,
 
     while (qemu_get_byte(f)) {
         elm = g_malloc(size);
-        ret = vmstate_load_state(f, vmsd, elm, version_id);
+        ret = vmstate_load_state(f, vmsd, elm, version_id, &local_err);
         if (ret) {
+            error_report_err(local_err);
             return ret;
         }
         QTAILQ_RAW_INSERT_TAIL(pv, elm, entry_offset);
@@ -772,6 +779,7 @@ static int get_gtree(QEMUFile *f, void *pv, size_t unused_size,
     GTree *tree = *pval;
     void *key, *val;
     int ret = 0;
+    Error *local_err = NULL;
 
     /* in case of direct key, the key vmsd can be {}, ie. check fields */
     if (!direct_key && version_id > key_vmsd->version_id) {
@@ -803,18 +811,16 @@ static int get_gtree(QEMUFile *f, void *pv, size_t unused_size,
             key = (void *)(uintptr_t)qemu_get_be64(f);
         } else {
             key = g_malloc0(key_size);
-            ret = vmstate_load_state(f, key_vmsd, key, version_id);
+            ret = vmstate_load_state(f, key_vmsd, key, version_id, &local_err);
             if (ret) {
-                error_report("%s : failed to load %s (%d)",
-                             field->name, key_vmsd->name, ret);
+                error_report_err(local_err);
                 goto key_error;
             }
         }
         val = g_malloc0(val_size);
-        ret = vmstate_load_state(f, val_vmsd, val, version_id);
+        ret = vmstate_load_state(f, val_vmsd, val, version_id, &local_err);
         if (ret) {
-            error_report("%s : failed to load %s (%d)",
-                         field->name, val_vmsd->name, ret);
+            error_report_err(local_err);
             goto val_error;
         }
         g_tree_insert(tree, key, val);
@@ -872,6 +878,7 @@ static int get_qlist(QEMUFile *f, void *pv, size_t unused_size,
                      const VMStateField *field)
 {
     int ret = 0;
+    Error *local_err = NULL;
     const VMStateDescription *vmsd = field->vmsd;
     /* size of a QLIST element */
     size_t size = field->size;
@@ -892,10 +899,9 @@ static int get_qlist(QEMUFile *f, void *pv, size_t unused_size,
 
     while (qemu_get_byte(f)) {
         elm = g_malloc(size);
-        ret = vmstate_load_state(f, vmsd, elm, version_id);
+        ret = vmstate_load_state(f, vmsd, elm, version_id, &local_err);
         if (ret) {
-            error_report("%s: failed to load %s (%d)", field->name,
-                         vmsd->name, ret);
+            error_report_err(local_err);
             g_free(elm);
             return ret;
         }