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, 13 insertions, 17 deletions

diff --git a/target-s390x/machine.c b/target-s390x/machine.c
index 004474959a..b76fb08319 100644
--- a/target-s390x/machine.c
+++ b/target-s390x/machine.c
@@ -42,10 +42,17 @@ static void cpu_pre_save(void *opaque)
     }
 }
 
+static inline bool fpu_needed(void *opaque)
+{
+    /* This looks odd, but we might want to NOT transfer fprs in the future */
+    return true;
+}
+
 const VMStateDescription vmstate_fpu = {
     .name = "cpu/fpu",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fpu_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.vregs[0][0].ll, S390CPU),
         VMSTATE_UINT64(env.vregs[1][0].ll, S390CPU),
@@ -68,16 +75,11 @@ const VMStateDescription vmstate_fpu = {
     }
 };
 
-static inline bool fpu_needed(void *opaque)
-{
-    /* This looks odd, but we might want to NOT transfer fprs in the future */
-    return true;
-}
-
 const VMStateDescription vmstate_vregs = {
     .name = "cpu/vregs",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = vregs_needed,
     .fields = (VMStateField[]) {
         /* vregs[0][0] -> vregs[15][0] and fregs are overlays */
         VMSTATE_UINT64(env.vregs[16][0].ll, S390CPU),
@@ -159,16 +161,10 @@ const VMStateDescription vmstate_s390_cpu = {
         VMSTATE_VBUFFER_UINT32(irqstate, S390CPU, 4, NULL, 0,
                                irqstate_saved_size),
         VMSTATE_END_OF_LIST()
-     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_fpu,
-            .needed = fpu_needed,
-        } , {
-            .vmsd = &vmstate_vregs,
-            .needed = vregs_needed,
-        } , {
-            /* empty */
-        }
+    },
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_fpu,
+        &vmstate_vregs,
+        NULL
     },
 };