migration: merge enforce_config_section somewhat

These two parameters:

- MachineState::enforce_config_section
- MigrationState::send_configuration

are playing similar role here. This patch merges the first one into
second, then we'll have a single place to reference whether we need to
send the configuration section.

I didn't remove the MachineState.enforce_config_section field since when
applying that machine property (in machine_set_property()) we haven't
yet initialized global properties and migration object. Then, it's
still not easy to pass that boolean to MigrationState at such an early
time.

A natural benefit for current patch is that now we kept the meaning of
"enforce-config-section" since it'll still have the highest
priority (that's what "enforce" mean I guess).

Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-10-git-send-email-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

migration/migration.c

@@ -42,6 +42,7 @@
 #include "exec/target_page.h"
 #include "io/channel-buffer.h"
 #include "migration/colo.h"
+#include "hw/boards.h"
 
 #define MAX_THROTTLE  (32 << 20)      /* Migration transfer speed throttling */
 
@@ -102,9 +103,20 @@ static MigrationState *current_migration;
 
 void migration_object_init(void)
 {
+    MachineState *ms = MACHINE(qdev_get_machine());
+
     /* This can only be called once. */
     assert(!current_migration);
     current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION));
+
+    /*
+     * We cannot really do this in migration_instance_init() since at
+     * that time global properties are not yet applied, then this
+     * value will be definitely replaced by something else.
+     */
+    if (ms->enforce_config_section) {
+        current_migration->send_configuration = true;
+    }
 }
 
 /* For outgoing */

migration/savevm.c

@@ -943,20 +943,13 @@ bool qemu_savevm_state_blocked(Error **errp)
     return false;
 }
 
-static bool enforce_config_section(void)
-{
-    MachineState *machine = MACHINE(qdev_get_machine());
-    return machine->enforce_config_section;
-}
-
 void qemu_savevm_state_header(QEMUFile *f)
 {
     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 (migrate_get_current()->send_configuration) {
-        enforce_config_section()) {
         qemu_put_byte(f, QEMU_VM_CONFIGURATION);
         vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
     }
@@ -1980,8 +1973,7 @@ int qemu_loadvm_state(QEMUFile *f)
         return -ENOTSUP;
     }
 
-    if (migrate_get_current()->send_configuration ||
+    if (migrate_get_current()->send_configuration) {
-        enforce_config_section()) {
         if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
             error_report("Configuration section missing");
             return -EINVAL;