rdma: export throughput w/ MigrationStats QMP

This exposes throughput (in megabits/sec) through QMP.
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChegu Vinod <chegu_vinod@hp.com>
Tested-by: NChegu Vinod <chegu_vinod@hp.com>
Tested-by: NMichael R. Hines <mrhines@us.ibm.com>
Signed-off-by: NMichael R. Hines <mrhines@us.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

hmp.c

@@ -169,6 +169,8 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
     if (info->has_ram) {
         monitor_printf(mon, "transferred ram: %" PRIu64 " kbytes\n",
                        info->ram->transferred >> 10);
+        monitor_printf(mon, "throughput: %0.2f mbps\n",
+                       info->ram->mbps);
         monitor_printf(mon, "remaining ram: %" PRIu64 " kbytes\n",
                        info->ram->remaining >> 10);
         monitor_printf(mon, "total ram: %" PRIu64 " kbytes\n",

include/migration/migration.h

@@ -40,6 +40,7 @@ struct MigrationState
 
     int state;
     MigrationParams params;
+    double mbps;
     int64_t total_time;
     int64_t downtime;
     int64_t expected_downtime;

migration.c

@@ -66,6 +66,7 @@ MigrationState *migrate_get_current(void)
         .state = MIG_STATE_SETUP,
         .bandwidth_limit = MAX_THROTTLE,
         .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
+        .mbps = -1,
     };
 
     return &current_migration;
@@ -201,6 +202,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
         info->ram->normal = norm_mig_pages_transferred();
         info->ram->normal_bytes = norm_mig_bytes_transferred();
         info->ram->dirty_pages_rate = s->dirty_pages_rate;
+        info->ram->mbps = s->mbps;
 
         if (blk_mig_active()) {
             info->has_disk = true;
@@ -230,6 +232,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
         info->ram->skipped = skipped_mig_pages_transferred();
         info->ram->normal = norm_mig_pages_transferred();
         info->ram->normal_bytes = norm_mig_bytes_transferred();
+        info->ram->mbps = s->mbps;
         break;
     case MIG_STATE_ERROR:
         info->has_status = true;
@@ -543,6 +546,9 @@ static void *migration_thread(void *opaque)
             double bandwidth = transferred_bytes / time_spent;
             max_size = bandwidth * migrate_max_downtime() / 1000000;
 
+            s->mbps = time_spent ? (((double) transferred_bytes * 8.0) /
+                    ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1;
+
             DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64
                     " bandwidth %g max_size %" PRId64 "\n",
                     transferred_bytes, time_spent, bandwidth, max_size);

qapi-schema.json

@@ -513,12 +513,15 @@
 # @dirty-pages-rate: number of pages dirtied by second by the
 #        guest (since 1.3)
 #
+# @mbps: throughput in megabits/sec. (since 1.6)
+#
 # Since: 0.14.0
 ##
 { 'type': 'MigrationStats',
   'data': {'transferred': 'int', 'remaining': 'int', 'total': 'int' ,
            'duplicate': 'int', 'skipped': 'int', 'normal': 'int',
-           'normal-bytes': 'int', 'dirty-pages-rate' : 'int' } }
+           'normal-bytes': 'int', 'dirty-pages-rate' : 'int',
+           'mbps' : 'number' } }
 
 ##
 # @XBZRLECacheStats