migration-test: Make sure that multifd and cancel works

Test that this sequence works:

- launch source
- launch target
- start migration
- cancel migration
- relaunch target
- do migration again

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

tests/qtest/migration-test.c

@@ -424,6 +424,14 @@ static void migrate_recover(QTestState *who, const char *uri)
     qobject_unref(rsp);
 }
 
+static void migrate_cancel(QTestState *who)
+{
+    QDict *rsp;
+
+    rsp = wait_command(who, "{ 'execute': 'migrate_cancel' }");
+    qobject_unref(rsp);
+}
+
 static void migrate_set_capability(QTestState *who, const char *capability,
                                    bool value)
 {
@@ -456,6 +464,8 @@ static void migrate_postcopy_start(QTestState *from, QTestState *to)
 typedef struct {
     bool hide_stderr;
     bool use_shmem;
+    /* only launch the target process */
+    bool only_target;
     char *opts_source;
     char *opts_target;
 } MigrateStart;
@@ -571,7 +581,9 @@ static int test_migrate_start(QTestState **from, QTestState **to,
                                  arch_source, shmem_opts, args->opts_source,
                                  ignore_stderr);
     g_free(arch_source);
-    *from = qtest_init(cmd_source);
+    if (!args->only_target) {
+        *from = qtest_init(cmd_source);
+    }
     g_free(cmd_source);
 
     cmd_target = g_strdup_printf("-accel kvm -accel tcg%s%s "
@@ -1294,6 +1306,103 @@ static void test_multifd_tcp(void)
     g_free(uri);
 }
 
+/*
+ * This test does:
+ *  source               target
+ *                       migrate_incoming
+ *     migrate
+ *     migrate_cancel
+ *                       launch another target
+ *     migrate
+ *
+ *  And see that it works
+ */
+
+static void test_multifd_tcp_cancel(void)
+{
+    MigrateStart *args = migrate_start_new();
+    QTestState *from, *to, *to2;
+    QDict *rsp;
+    char *uri;
+
+    args->hide_stderr = true;
+
+    if (test_migrate_start(&from, &to, "defer", args)) {
+        return;
+    }
+
+    /*
+     * We want to pick a speed slow enough that the test completes
+     * quickly, but that it doesn't complete precopy even on a slow
+     * machine, so also set the downtime.
+     */
+    /* 1 ms should make it not converge*/
+    migrate_set_parameter_int(from, "downtime-limit", 1);
+    /* 300MB/s */
+    migrate_set_parameter_int(from, "max-bandwidth", 30000000);
+
+    migrate_set_parameter_int(from, "multifd-channels", 16);
+    migrate_set_parameter_int(to, "multifd-channels", 16);
+
+    migrate_set_capability(from, "multifd", "true");
+    migrate_set_capability(to, "multifd", "true");
+
+    /* Start incoming migration from the 1st socket */
+    rsp = wait_command(to, "{ 'execute': 'migrate-incoming',"
+                           "  'arguments': { 'uri': 'tcp:127.0.0.1:0' }}");
+    qobject_unref(rsp);
+
+    /* Wait for the first serial output from the source */
+    wait_for_serial("src_serial");
+
+    uri = migrate_get_socket_address(to, "socket-address");
+
+    migrate_qmp(from, uri, "{}");
+
+    wait_for_migration_pass(from);
+
+    migrate_cancel(from);
+
+    args = migrate_start_new();
+    args->only_target = true;
+
+    if (test_migrate_start(&from, &to2, "defer", args)) {
+        return;
+    }
+
+    migrate_set_parameter_int(to2, "multifd-channels", 16);
+
+    migrate_set_capability(to2, "multifd", "true");
+
+    /* Start incoming migration from the 1st socket */
+    rsp = wait_command(to2, "{ 'execute': 'migrate-incoming',"
+                            "  'arguments': { 'uri': 'tcp:127.0.0.1:0' }}");
+    qobject_unref(rsp);
+
+    uri = migrate_get_socket_address(to2, "socket-address");
+
+    wait_for_migration_status(from, "cancelled", NULL);
+
+    /* 300ms it should converge */
+    migrate_set_parameter_int(from, "downtime-limit", 300);
+    /* 1GB/s */
+    migrate_set_parameter_int(from, "max-bandwidth", 1000000000);
+
+    migrate_qmp(from, uri, "{}");
+
+    wait_for_migration_pass(from);
+
+    if (!got_stop) {
+        qtest_qmp_eventwait(from, "STOP");
+    }
+    qtest_qmp_eventwait(to2, "RESUME");
+
+    wait_for_serial("dest_serial");
+    wait_for_migration_complete(from);
+    test_migrate_end(from, to2, true);
+    g_free(uri);
+}
+
 int main(int argc, char **argv)
 {
     char template[] = "/tmp/migration-test-XXXXXX";
@@ -1359,6 +1468,7 @@ int main(int argc, char **argv)
 
     qtest_add_func("/migration/auto_converge", test_migrate_auto_converge);
     qtest_add_func("/migration/multifd/tcp", test_multifd_tcp);
+    qtest_add_func("/migration/multifd/tcp/cancel", test_multifd_tcp_cancel);
 
     ret = g_test_run();