migration: add an indicator for bulk state of ram migration

the first round of ram transfer is special since all pages
are dirty and thus all memory pages are transferred to
the target. this patch adds a boolean variable to track
this stage.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

arch_init.c

@@ -319,6 +319,7 @@ static ram_addr_t last_offset;
 static unsigned long *migration_bitmap;
 static uint64_t migration_dirty_pages;
 static uint32_t last_version;
+static bool ram_bulk_stage;
 
 static inline
 ram_addr_t migration_bitmap_find_and_reset_dirty(MemoryRegion *mr,
@@ -426,6 +427,7 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
             if (!block) {
                 block = QTAILQ_FIRST(&ram_list.blocks);
                 complete_round = true;
+                ram_bulk_stage = false;
             }
         } else {
             uint8_t *p;
@@ -529,6 +531,7 @@ static void reset_ram_globals(void)
     last_sent_block = NULL;
     last_offset = 0;
     last_version = ram_list.version;
+    ram_bulk_stage = true;
 }
 
 #define MAX_WAIT 50 /* ms, half buffered_file limit */