migration: Create migrate_downtime_limit() function

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
diff --git a/migration/migration.c b/migration/migration.c
index 45fc5be..ee8e941 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2737,7 +2737,7 @@
     transferred = current_bytes - s->iteration_initial_bytes;
     time_spent = current_time - s->iteration_start_time;
     bandwidth = (double)transferred / time_spent;
-    s->threshold_size = bandwidth * s->parameters.downtime_limit;
+    s->threshold_size = bandwidth * migrate_downtime_limit();
 
     s->mbps = (((double) transferred * 8.0) /
                ((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
@@ -3244,7 +3244,7 @@
      */
     migrate_error_free(s);
 
-    s->expected_downtime = s->parameters.downtime_limit;
+    s->expected_downtime = migrate_downtime_limit();
     if (resume) {
         assert(s->cleanup_bh);
     } else {
diff --git a/migration/options.c b/migration/options.c
index 0b1b56e..f4ffe99 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -518,6 +518,13 @@
     return s->parameters.decompress_threads;
 }
 
+uint64_t migrate_downtime_limit(void)
+{
+    MigrationState *s = migrate_get_current();
+
+    return s->parameters.downtime_limit;
+}
+
 uint8_t migrate_max_cpu_throttle(void)
 {
     MigrationState *s = migrate_get_current();
diff --git a/migration/options.h b/migration/options.h
index 86bcbb7..e982103 100644
--- a/migration/options.h
+++ b/migration/options.h
@@ -71,6 +71,7 @@
 uint8_t migrate_cpu_throttle_initial(void);
 bool migrate_cpu_throttle_tailslow(void);
 int migrate_decompress_threads(void);
+uint64_t migrate_downtime_limit(void);
 uint8_t migrate_max_cpu_throttle(void);
 uint64_t migrate_max_bandwidth(void);
 int64_t migrate_max_postcopy_bandwidth(void);