diff --git a/migration/ram.c b/migration/ram.c
index 85bc36101c..2b0774c2bf 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3213,11 +3213,11 @@ static int ram_state_init(RAMState **rsp)
     QSIMPLEQ_INIT(&(*rsp)->src_page_requests);
 
     /*
+     * Count the total number of pages used by ram blocks not including any
+     * gaps due to alignment or unplugs.
      * This must match with the initial values of dirty bitmap.
-     * Currently we initialize the dirty bitmap to all zeros so
-     * here the total dirty page count is zero.
      */
-    (*rsp)->migration_dirty_pages = 0;
+    (*rsp)->migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS;
     ram_state_reset(*rsp);
 
     return 0;
@@ -3249,12 +3249,13 @@ static void ram_list_init_bitmaps(void)
              * The initial dirty bitmap for migration must be set with all
              * ones to make sure we'll migrate every guest RAM page to
              * destination.
-             * Here we didn't set RAMBlock.bmap simply because it is already
-             * set in ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION] in
-             * ram_block_add, and that's where we'll sync the dirty bitmaps.
-             * Here setting RAMBlock.bmap would be fine too but not necessary.
+             * Here we set RAMBlock.bmap all to 1 because when rebegin a
+             * new migration after a failed migration, ram_list.
+             * dirty_memory[DIRTY_MEMORY_MIGRATION] don't include the whole
+             * guest memory.
              */
             block->bmap = bitmap_new(pages);
+            bitmap_set(block->bmap, 0, pages);
             block->clear_bmap_shift = shift;
             block->clear_bmap = bitmap_new(clear_bmap_size(pages, shift));
             if (migrate_postcopy_ram()) {