diff --git a/migration/migration-stats.h b/migration/migration-stats.h
index 1775b916df..9f9a8eb9eb 100644
--- a/migration/migration-stats.h
+++ b/migration/migration-stats.h
@@ -36,6 +36,13 @@ typedef struct {
      * best-effort estimation on expected downtime.
      */
     uint64_t dirty_bytes_last_sync;
+    /*
+     * Number of bytes that were reported dirty now.  This is an estimate
+     * value and will be updated every time migration thread queries from
+     * modules in an iteration loop.  It is used to provide best-effort
+     * estimation on total remaining data.
+     */
+    uint64_t dirty_bytes_total;
     /*
      * Number of pages dirtied per second.
      */
diff --git a/migration/savevm.c b/migration/savevm.c
index 39430470aa..d1dd696c17 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1815,6 +1815,13 @@ void qemu_savevm_query_pending(MigPendingData *pending, bool exact)
     pending->total_bytes = pending->precopy_bytes +
         pending->stopcopy_bytes + pending->postcopy_bytes;
 
+    /*
+     * Update system remaining dirty bytes whenever QEMU queries.  It will
+     * make the value to be not as accurate, but should still be pretty
+     * close to reality when this got invoked frequently while iterating.
+     */
+    mig_stats.dirty_bytes_total = pending->total_bytes;
+
     trace_qemu_savevm_query_pending(exact, pending->precopy_bytes,
                                     pending->stopcopy_bytes,
                                     pending->postcopy_bytes,