diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 5b25ba2..d206700 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -321,6 +321,10 @@
         monitor_printf(mon, "%s: %" PRIu64 " bytes/second\n",
             MigrationParameter_str(MIGRATION_PARAMETER_MAX_BANDWIDTH),
             params->max_bandwidth);
+        assert(params->has_avail_switchover_bandwidth);
+        monitor_printf(mon, "%s: %" PRIu64 " bytes/second\n",
+            MigrationParameter_str(MIGRATION_PARAMETER_AVAIL_SWITCHOVER_BANDWIDTH),
+            params->avail_switchover_bandwidth);
         assert(params->has_downtime_limit);
         monitor_printf(mon, "%s: %" PRIu64 " ms\n",
             MigrationParameter_str(MIGRATION_PARAMETER_DOWNTIME_LIMIT),
@@ -574,6 +578,16 @@
         }
         p->max_bandwidth = valuebw;
         break;
+    case MIGRATION_PARAMETER_AVAIL_SWITCHOVER_BANDWIDTH:
+        p->has_avail_switchover_bandwidth = true;
+        ret = qemu_strtosz_MiB(valuestr, NULL, &valuebw);
+        if (ret < 0 || valuebw > INT64_MAX
+            || (size_t)valuebw != valuebw) {
+            error_setg(&err, "Invalid size %s", valuestr);
+            break;
+        }
+        p->avail_switchover_bandwidth = valuebw;
+        break;
     case MIGRATION_PARAMETER_DOWNTIME_LIMIT:
         p->has_downtime_limit = true;
         visit_type_size(v, param, &p->downtime_limit, &err);
diff --git a/migration/migration.c b/migration/migration.c
index 0e1002d..ed04ca3 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2710,17 +2710,33 @@
 {
     uint64_t transferred, transferred_pages, time_spent;
     uint64_t current_bytes; /* bytes transferred since the beginning */
+    uint64_t switchover_bw;
+    /* Expected bandwidth when switching over to destination QEMU */
+    double expected_bw_per_ms;
     double bandwidth;
 
     if (current_time < s->iteration_start_time + BUFFER_DELAY) {
         return;
     }
 
+    switchover_bw = migrate_avail_switchover_bandwidth();
     current_bytes = migration_transferred_bytes(s->to_dst_file);
     transferred = current_bytes - s->iteration_initial_bytes;
     time_spent = current_time - s->iteration_start_time;
     bandwidth = (double)transferred / time_spent;
-    s->threshold_size = bandwidth * migrate_downtime_limit();
+
+    if (switchover_bw) {
+        /*
+         * If the user specified a switchover bandwidth, let's trust the
+         * user so that can be more accurate than what we estimated.
+         */
+        expected_bw_per_ms = switchover_bw / 1000;
+    } else {
+        /* If the user doesn't specify bandwidth, we use the estimated */
+        expected_bw_per_ms = bandwidth;
+    }
+
+    s->threshold_size = expected_bw_per_ms * migrate_downtime_limit();
 
     s->mbps = (((double) transferred * 8.0) /
                ((double) time_spent / 1000.0)) / 1000.0 / 1000.0;
@@ -2737,7 +2753,7 @@
     if (stat64_get(&mig_stats.dirty_pages_rate) &&
         transferred > 10000) {
         s->expected_downtime =
-            stat64_get(&mig_stats.dirty_bytes_last_sync) / bandwidth;
+            stat64_get(&mig_stats.dirty_bytes_last_sync) / expected_bw_per_ms;
     }
 
     migration_rate_reset(s->to_dst_file);
@@ -2745,7 +2761,9 @@
     update_iteration_initial_status(s);
 
     trace_migrate_transferred(transferred, time_spent,
-                              bandwidth, s->threshold_size);
+                              /* Both in unit bytes/ms */
+                              bandwidth, switchover_bw / 1000,
+                              s->threshold_size);
 }
 
 static bool migration_can_switchover(MigrationState *s)
diff --git a/migration/migration.h b/migration/migration.h
index cd55343..974897a 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -294,7 +294,7 @@
     /*
      * The final stage happens when the remaining data is smaller than
      * this threshold; it's calculated from the requested downtime and
-     * measured bandwidth
+     * measured bandwidth, or avail-switchover-bandwidth if specified.
      */
     int64_t threshold_size;
 
diff --git a/migration/options.c b/migration/options.c
index 6bbfd48..546cbe3 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -125,6 +125,8 @@
                       parameters.cpu_throttle_tailslow, false),
     DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState,
                       parameters.max_bandwidth, MAX_THROTTLE),
+    DEFINE_PROP_SIZE("avail-switchover-bandwidth", MigrationState,
+                      parameters.avail_switchover_bandwidth, 0),
     DEFINE_PROP_UINT64("x-downtime-limit", MigrationState,
                       parameters.downtime_limit,
                       DEFAULT_MIGRATE_SET_DOWNTIME),
@@ -780,6 +782,13 @@
     return s->parameters.max_bandwidth;
 }
 
+uint64_t migrate_avail_switchover_bandwidth(void)
+{
+    MigrationState *s = migrate_get_current();
+
+    return s->parameters.avail_switchover_bandwidth;
+}
+
 uint64_t migrate_max_postcopy_bandwidth(void)
 {
     MigrationState *s = migrate_get_current();
@@ -917,6 +926,8 @@
                                  s->parameters.tls_authz : "");
     params->has_max_bandwidth = true;
     params->max_bandwidth = s->parameters.max_bandwidth;
+    params->has_avail_switchover_bandwidth = true;
+    params->avail_switchover_bandwidth = s->parameters.avail_switchover_bandwidth;
     params->has_downtime_limit = true;
     params->downtime_limit = s->parameters.downtime_limit;
     params->has_x_checkpoint_delay = true;
@@ -1056,6 +1067,15 @@
         return false;
     }
 
+    if (params->has_avail_switchover_bandwidth &&
+        (params->avail_switchover_bandwidth > SIZE_MAX)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                   "avail_switchover_bandwidth",
+                   "an integer in the range of 0 to "stringify(SIZE_MAX)
+                   " bytes/second");
+        return false;
+    }
+
     if (params->has_downtime_limit &&
         (params->downtime_limit > MAX_MIGRATE_DOWNTIME)) {
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
@@ -1225,6 +1245,10 @@
         dest->max_bandwidth = params->max_bandwidth;
     }
 
+    if (params->has_avail_switchover_bandwidth) {
+        dest->avail_switchover_bandwidth = params->avail_switchover_bandwidth;
+    }
+
     if (params->has_downtime_limit) {
         dest->downtime_limit = params->downtime_limit;
     }
@@ -1341,6 +1365,10 @@
         }
     }
 
+    if (params->has_avail_switchover_bandwidth) {
+        s->parameters.avail_switchover_bandwidth = params->avail_switchover_bandwidth;
+    }
+
     if (params->has_downtime_limit) {
         s->parameters.downtime_limit = params->downtime_limit;
     }
diff --git a/migration/options.h b/migration/options.h
index 045e2a4..93ee938 100644
--- a/migration/options.h
+++ b/migration/options.h
@@ -80,6 +80,7 @@
 uint64_t migrate_downtime_limit(void);
 uint8_t migrate_max_cpu_throttle(void);
 uint64_t migrate_max_bandwidth(void);
+uint64_t migrate_avail_switchover_bandwidth(void);
 uint64_t migrate_max_postcopy_bandwidth(void);
 int migrate_multifd_channels(void);
 MultiFDCompression migrate_multifd_compression(void);
diff --git a/migration/trace-events b/migration/trace-events
index ee9c8f4..d8c2aa8 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -186,7 +186,7 @@
 source_return_path_thread_resume_ack(uint32_t v) "%"PRIu32
 source_return_path_thread_switchover_acked(void) ""
 migration_thread_low_pending(uint64_t pending) "%" PRIu64
-migrate_transferred(uint64_t transferred, uint64_t time_spent, uint64_t bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %" PRIu64 " max_size %" PRId64
+migrate_transferred(uint64_t transferred, uint64_t time_spent, uint64_t bandwidth, uint64_t avail_bw, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %" PRIu64 " switchover_bw %" PRIu64 " max_size %" PRId64
 process_incoming_migration_co_end(int ret, int ps) "ret=%d postcopy-state=%d"
 process_incoming_migration_co_postcopy_end_main(void) ""
 postcopy_preempt_enabled(bool value) "%d"
diff --git a/qapi/migration.json b/qapi/migration.json
index d7dfaa5..360e609 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -758,6 +758,16 @@
 # @max-bandwidth: to set maximum speed for migration.  maximum speed
 #     in bytes per second.  (Since 2.8)
 #
+# @avail-switchover-bandwidth: to set the available bandwidth that
+#     migration can use during switchover phase.  NOTE!  This does not
+#     limit the bandwidth during switchover, but only for calculations when
+#     making decisions to switchover.  By default, this value is zero,
+#     which means QEMU will estimate the bandwidth automatically.  This can
+#     be set when the estimated value is not accurate, while the user is
+#     able to guarantee such bandwidth is available when switching over.
+#     When specified correctly, this can make the switchover decision much
+#     more accurate.  (Since 8.2)
+#
 # @downtime-limit: set maximum tolerated downtime for migration.
 #     maximum downtime in milliseconds (Since 2.8)
 #
@@ -839,7 +849,7 @@
            'cpu-throttle-initial', 'cpu-throttle-increment',
            'cpu-throttle-tailslow',
            'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth',
-           'downtime-limit',
+           'avail-switchover-bandwidth', 'downtime-limit',
            { 'name': 'x-checkpoint-delay', 'features': [ 'unstable' ] },
            'block-incremental',
            'multifd-channels',
@@ -924,6 +934,16 @@
 # @max-bandwidth: to set maximum speed for migration.  maximum speed
 #     in bytes per second.  (Since 2.8)
 #
+# @avail-switchover-bandwidth: to set the available bandwidth that
+#     migration can use during switchover phase.  NOTE!  This does not
+#     limit the bandwidth during switchover, but only for calculations when
+#     making decisions to switchover.  By default, this value is zero,
+#     which means QEMU will estimate the bandwidth automatically.  This can
+#     be set when the estimated value is not accurate, while the user is
+#     able to guarantee such bandwidth is available when switching over.
+#     When specified correctly, this can make the switchover decision much
+#     more accurate.  (Since 8.2)
+#
 # @downtime-limit: set maximum tolerated downtime for migration.
 #     maximum downtime in milliseconds (Since 2.8)
 #
@@ -1017,6 +1037,7 @@
             '*tls-hostname': 'StrOrNull',
             '*tls-authz': 'StrOrNull',
             '*max-bandwidth': 'size',
+            '*avail-switchover-bandwidth': 'size',
             '*downtime-limit': 'uint64',
             '*x-checkpoint-delay': { 'type': 'uint32',
                                      'features': [ 'unstable' ] },
@@ -1127,6 +1148,16 @@
 # @max-bandwidth: to set maximum speed for migration.  maximum speed
 #     in bytes per second.  (Since 2.8)
 #
+# @avail-switchover-bandwidth: to set the available bandwidth that
+#     migration can use during switchover phase.  NOTE!  This does not
+#     limit the bandwidth during switchover, but only for calculations when
+#     making decisions to switchover.  By default, this value is zero,
+#     which means QEMU will estimate the bandwidth automatically.  This can
+#     be set when the estimated value is not accurate, while the user is
+#     able to guarantee such bandwidth is available when switching over.
+#     When specified correctly, this can make the switchover decision much
+#     more accurate.  (Since 8.2)
+#
 # @downtime-limit: set maximum tolerated downtime for migration.
 #     maximum downtime in milliseconds (Since 2.8)
 #
@@ -1217,6 +1248,7 @@
             '*tls-hostname': 'str',
             '*tls-authz': 'str',
             '*max-bandwidth': 'size',
+            '*avail-switchover-bandwidth': 'size',
             '*downtime-limit': 'uint64',
             '*x-checkpoint-delay': { 'type': 'uint32',
                                      'features': [ 'unstable' ] },