migration: Use normal VMStateDescriptions for Subsections

We create optional sections with this patch.  But we already have
optional subsections.  Instead of having two mechanism that do the
same, we can just generalize it.

For subsections we just change:

- Add a needed function to VMStateDescription
- Remove VMStateSubsection (after removal of the needed function
  it is just a VMStateDescription)
- Adjust the whole tree, moving the needed function to the corresponding
  VMStateDescription

Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index bc7616a..fc5e643 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -120,11 +120,6 @@ typedef struct {
     bool (*field_exists)(void *opaque, int version_id);
 } VMStateField;
 
-typedef struct VMStateSubsection {
-    const VMStateDescription *vmsd;
-    bool (*needed)(void *opaque);
-} VMStateSubsection;
-
 struct VMStateDescription {
     const char *name;
     int unmigratable;
@@ -135,8 +130,9 @@ struct VMStateDescription {
     int (*pre_load)(void *opaque);
     int (*post_load)(void *opaque, int version_id);
     void (*pre_save)(void *opaque);
+    bool (*needed)(void *opaque);
     VMStateField *fields;
-    const VMStateSubsection *subsections;
+    const VMStateDescription **subsections;
 };
 
 extern const VMStateDescription vmstate_dummy;