tests: Add basic migration precopy tcp test

Not sharing code from precopy/unix because we have to read back the
tcp parameter.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>

Message-Id: <20190227105128.1655-4-quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert:  Fixup for clash with Yury's

tests/migration-test.c

@@ -20,6 +20,9 @@
 #include "qemu/sockets.h"
 #include "chardev/char.h"
 #include "sysemu/sysemu.h"
+#include "qapi/qapi-visit-sockets.h"
+#include "qapi/qobject-input-visitor.h"
+#include "qapi/qobject-output-visitor.h"
 
 #include "migration/migration-test.h"
 
@@ -344,15 +347,68 @@ static char *get_shmem_opts(const char *mem_size, const char *shmem_path)
                            mem_size, shmem_path);
 }
 
+static char *SocketAddress_to_str(SocketAddress *addr)
+{
+    switch (addr->type) {
+    case SOCKET_ADDRESS_TYPE_INET:
+        return g_strdup_printf("tcp:%s:%s",
+                               addr->u.inet.host,
+                               addr->u.inet.port);
+    case SOCKET_ADDRESS_TYPE_UNIX:
+        return g_strdup_printf("unix:%s",
+                               addr->u.q_unix.path);
+    case SOCKET_ADDRESS_TYPE_FD:
+        return g_strdup_printf("fd:%s", addr->u.fd.str);
+    case SOCKET_ADDRESS_TYPE_VSOCK:
+        return g_strdup_printf("tcp:%s:%s",
+                               addr->u.vsock.cid,
+                               addr->u.vsock.port);
+    default:
+        return g_strdup("unknown address type");
+    }
+}
+
+static char *migrate_get_socket_address(QTestState *who, const char *parameter)
+{
+    QDict *rsp;
+    char *result;
+    Error *local_err = NULL;
+    SocketAddressList *addrs;
+    Visitor *iv = NULL;
+    QObject *object;
+
+    rsp = migrate_query(who);
+    object = qdict_get(rsp, parameter);
+
+    iv = qobject_input_visitor_new(object);
+    visit_type_SocketAddressList(iv, NULL, &addrs, &local_err);
+
+    /* we are only using a single address */
+    result = g_strdup_printf("%s", SocketAddress_to_str(addrs->value));
+
+    qapi_free_SocketAddressList(addrs);
+    qobject_unref(rsp);
+    return result;
+}
+
+static long long migrate_get_parameter(QTestState *who, const char *parameter)
+{
+    QDict *rsp;
+    long long result;
+
+    rsp = wait_command(who, "{ 'execute': 'query-migrate-parameters' }");
+    result = qdict_get_int(rsp, parameter);
+    qobject_unref(rsp);
+    return result;
+}
+
 static void migrate_check_parameter(QTestState *who, const char *parameter,
                                     long long value)
 {
-    QDict *rsp_return;
+    long long result;
 
-    rsp_return = wait_command(who,
+    result = migrate_get_parameter(who, parameter);
-                              "{ 'execute': 'query-migrate-parameters' }");
+    g_assert_cmpint(result, ==, value);
-    g_assert_cmpint(qdict_get_int(rsp_return, parameter), ==, value);
-    qobject_unref(rsp_return);
 }
 
 static void migrate_set_parameter(QTestState *who, const char *parameter,
@@ -927,6 +983,49 @@ static void test_xbzrle_unix(void)
     g_free(uri);
 }
 
+static void test_precopy_tcp(void)
+{
+    char *uri;
+    QTestState *from, *to;
+
+    if (test_migrate_start(&from, &to, "tcp:127.0.0.1:0", false, false)) {
+        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(from, "downtime-limit", 1);
+    /* 1GB/s */
+    migrate_set_parameter(from, "max-bandwidth", 1000000000);
+
+    /* Wait for the first serial output from the source */
+    wait_for_serial("src_serial");
+
+    uri = migrate_get_socket_address(to, "socket-address");
+
+    migrate(from, uri, "{}");
+
+    wait_for_migration_pass(from);
+
+    /* 300ms should converge */
+    migrate_set_parameter(from, "downtime-limit", 300);
+
+    if (!got_stop) {
+        qtest_qmp_eventwait(from, "STOP");
+    }
+    qtest_qmp_eventwait(to, "RESUME");
+
+    wait_for_serial("dest_serial");
+    wait_for_migration_complete(from);
+
+    test_migrate_end(from, to, true);
+    g_free(uri);
+}
+
 int main(int argc, char **argv)
 {
     char template[] = "/tmp/migration-test-XXXXXX";
@@ -978,6 +1077,7 @@ int main(int argc, char **argv)
     qtest_add_func("/migration/deprecated", test_deprecated);
     qtest_add_func("/migration/bad_dest", test_baddest);
     qtest_add_func("/migration/precopy/unix", test_precopy_unix);
+    qtest_add_func("/migration/precopy/tcp", test_precopy_tcp);
     /* qtest_add_func("/migration/ignore_shared", test_ignore_shared); */
     qtest_add_func("/migration/xbzrle/unix", test_xbzrle_unix);