diff --git a/migration/ram.c b/migration/ram.c
index f0ddd5eabe..01521de71f 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -71,27 +71,6 @@
 /***********************************************************/
 /* ram save/restore */
 
-/*
- * RAM_SAVE_FLAG_ZERO used to be named RAM_SAVE_FLAG_COMPRESS, it
- * worked for pages that were filled with the same char.  We switched
- * it to only search for the zero value.  And to avoid confusion with
- * RAM_SAVE_FLAG_COMPRESS_PAGE just rename it.
- *
- * RAM_SAVE_FLAG_FULL was obsoleted in 2009.
- *
- * RAM_SAVE_FLAG_COMPRESS_PAGE (0x100) was removed in QEMU 9.1.
- */
-#define RAM_SAVE_FLAG_FULL     0x01
-#define RAM_SAVE_FLAG_ZERO     0x02
-#define RAM_SAVE_FLAG_MEM_SIZE 0x04
-#define RAM_SAVE_FLAG_PAGE     0x08
-#define RAM_SAVE_FLAG_EOS      0x10
-#define RAM_SAVE_FLAG_CONTINUE 0x20
-#define RAM_SAVE_FLAG_XBZRLE   0x40
-/* 0x80 is reserved in rdma.h for RAM_SAVE_FLAG_HOOK */
-#define RAM_SAVE_FLAG_MULTIFD_FLUSH    0x200
-/* We can't use any flag that is bigger than 0x200 */
-
 /*
  * mapped-ram migration supports O_DIRECT, so we need to make sure the
  * userspace buffer, the IO operation size and the file offset are
diff --git a/migration/ram.h b/migration/ram.h
index 0d1981f888..921c39a2c5 100644
--- a/migration/ram.h
+++ b/migration/ram.h
@@ -33,6 +33,34 @@
 #include "exec/cpu-common.h"
 #include "io/channel.h"
 
+/*
+ * RAM_SAVE_FLAG_ZERO used to be named RAM_SAVE_FLAG_COMPRESS, it
+ * worked for pages that were filled with the same char.  We switched
+ * it to only search for the zero value.  And to avoid confusion with
+ * RAM_SAVE_FLAG_COMPRESS_PAGE just rename it.
+ *
+ * RAM_SAVE_FLAG_FULL (0x01) was obsoleted in 2009.
+ *
+ * RAM_SAVE_FLAG_COMPRESS_PAGE (0x100) was removed in QEMU 9.1.
+ *
+ * RAM_SAVE_FLAG_HOOK is only used in RDMA. Whenever this is found in the
+ * data stream, the flags will be passed to rdma functions in the
+ * incoming-migration side.
+ *
+ * We can't use any flag that is bigger than 0x200, because the flags are
+ * always assumed to be encoded in a ramblock address offset, which is
+ * multiple of PAGE_SIZE.  Here it means QEMU supports migration with any
+ * architecture that has PAGE_SIZE>=1K (0x400).
+ */
+#define RAM_SAVE_FLAG_ZERO                    0x002
+#define RAM_SAVE_FLAG_MEM_SIZE                0x004
+#define RAM_SAVE_FLAG_PAGE                    0x008
+#define RAM_SAVE_FLAG_EOS                     0x010
+#define RAM_SAVE_FLAG_CONTINUE                0x020
+#define RAM_SAVE_FLAG_XBZRLE                  0x040
+#define RAM_SAVE_FLAG_HOOK                    0x080
+#define RAM_SAVE_FLAG_MULTIFD_FLUSH           0x200
+
 extern XBZRLECacheStats xbzrle_counters;
 
 /* Should be holding either ram_list.mutex, or the RCU lock. */
diff --git a/migration/rdma.h b/migration/rdma.h
index a8d27f33b8..f55f28bbed 100644
--- a/migration/rdma.h
+++ b/migration/rdma.h
@@ -33,13 +33,6 @@ void rdma_start_incoming_migration(InetSocketAddress *host_port, Error **errp);
 #define RAM_CONTROL_ROUND     1
 #define RAM_CONTROL_FINISH    3
 
-/*
- * Whenever this is found in the data stream, the flags
- * will be passed to rdma functions in the incoming-migration
- * side.
- */
-#define RAM_SAVE_FLAG_HOOK     0x80
-
 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
 #define RAM_SAVE_CONTROL_DELAYED  -2000