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>

2 files changed, 13 insertions, 13 deletions

diff --git a/migration/savevm.c b/migration/savevm.c
index 1a45d39a4b..002f9b8948 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -272,11 +272,11 @@ static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field,
 }
 
 static void dump_vmstate_vmss(FILE *out_file,
-                              const VMStateSubsection *subsection,
+                              const VMStateDescription **subsection,
                               int indent)
 {
-    if (subsection->vmsd != NULL) {
-        dump_vmstate_vmsd(out_file, subsection->vmsd, indent, true);
+    if (*subsection != NULL) {
+        dump_vmstate_vmsd(out_file, *subsection, indent, true);
     }
 }
 
@@ -317,12 +317,12 @@ static void dump_vmstate_vmsd(FILE *out_file,
         fprintf(out_file, "\n%*s]", indent, "");
     }
     if (vmsd->subsections != NULL) {
-        const VMStateSubsection *subsection = vmsd->subsections;
+        const VMStateDescription **subsection = vmsd->subsections;
         bool first;
 
         fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, "");
         first = true;
-        while (subsection->vmsd != NULL) {
+        while (*subsection != NULL) {
             if (!first) {
                 fprintf(out_file, ",\n");
             }
diff --git a/migration/vmstate.c b/migration/vmstate.c
index e5388f0596..108995ec78 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -341,11 +341,11 @@ void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
 }
 
 static const VMStateDescription *
-    vmstate_get_subsection(const VMStateSubsection *sub, char *idstr)
+vmstate_get_subsection(const VMStateDescription **sub, char *idstr)
 {
-    while (sub && sub->needed) {
-        if (strcmp(idstr, sub->vmsd->name) == 0) {
-            return sub->vmsd;
+    while (sub && *sub && (*sub)->needed) {
+        if (strcmp(idstr, (*sub)->name) == 0) {
+            return *sub;
         }
         sub++;
     }
@@ -405,12 +405,12 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
 static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
                                     void *opaque, QJSON *vmdesc)
 {
-    const VMStateSubsection *sub = vmsd->subsections;
+    const VMStateDescription **sub = vmsd->subsections;
     bool subsection_found = false;
 
-    while (sub && sub->needed) {
-        if (sub->needed(opaque)) {
-            const VMStateDescription *vmsd = sub->vmsd;
+    while (sub && *sub && (*sub)->needed) {
+        if ((*sub)->needed(opaque)) {
+            const VMStateDescription *vmsd = *sub;
             uint8_t len;
 
             if (vmdesc) {