migration: Change SaveStateEntry.instance_id into uint32_t

It was always used as 32bit, so define it as used to be clear.
Instead of using -1 as the auto-gen magic value, we switch to
UINT32_MAX.  We also make sure that we don't auto-gen this value to
avoid overflowed instance IDs without being noticed.

Suggested-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/migration/register.h b/include/migration/register.h
index 00c38ebe9f..c1dcff0f90 100644
--- a/include/migration/register.h
+++ b/include/migration/register.h
@@ -71,7 +71,7 @@ typedef struct SaveVMHandlers {
 } SaveVMHandlers;
 
 int register_savevm_live(const char *idstr,
-                         int instance_id,
+                         uint32_t instance_id,
                          int version_id,
                          const SaveVMHandlers *ops,
                          void *opaque);