[PATCH v2 1/6] migration: Add the configuration vmstate to the json writer

[Fabiano Rosas]

From: Nikolay Borisov <nborisov@suse.com>

Make the migration json writer part of MigrationState struct, allowing
the 'configuration' object be serialized to json.

This will facilitate the parsing of the 'configuration' object in the
next patch that fixes analyze-migration.py for arm.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
farosas: rewrote the commit message. The previous one was tied to
fixed-ram.
---
 migration/migration.c |  1 +
 migration/savevm.c    | 20 ++++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index 585d3c8f55..dde8471f83 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1430,6 +1430,7 @@ int migrate_init(MigrationState *s, Error **errp)
     error_free(s->error);
     s->error = NULL;
     s->hostname = NULL;
+    s->vmdesc = NULL;
 
     migrate_set_state(&s->state, MIGRATION_STATUS_NONE, 
MIGRATION_STATUS_SETUP);
 
diff --git a/migration/savevm.c b/migration/savevm.c
index 60eec7c31f..5343cbc234 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1217,13 +1217,27 @@ void qemu_savevm_non_migratable_list(strList **reasons)
 
 void qemu_savevm_state_header(QEMUFile *f)
 {
+    MigrationState *s = migrate_get_current();
+
+    s->vmdesc = json_writer_new(false);
+
     trace_savevm_state_header();
     qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
     qemu_put_be32(f, QEMU_VM_FILE_VERSION);
 
-    if (migrate_get_current()->send_configuration) {
+    if (s->send_configuration) {
         qemu_put_byte(f, QEMU_VM_CONFIGURATION);
-        vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
+
+        /*
+         * This starts the main json object and is paired with the
+         * json_writer_end_object in
+         * qemu_savevm_state_complete_precopy_non_iterable
+         */
+        json_writer_start_object(s->vmdesc, NULL);
+
+        json_writer_start_object(s->vmdesc, "configuration");
+        vmstate_save_state(f, &vmstate_configuration, &savevm_state, 
s->vmdesc);
+        json_writer_end_object(s->vmdesc);
     }
 }
 
@@ -1272,8 +1286,6 @@ void qemu_savevm_state_setup(QEMUFile *f)
     Error *local_err = NULL;
     int ret;
 
-    ms->vmdesc = json_writer_new(false);
-    json_writer_start_object(ms->vmdesc, NULL);
     json_writer_int64(ms->vmdesc, "page_size", qemu_target_page_size());
     json_writer_start_array(ms->vmdesc, "devices");
 
-- 
2.35.3