migration-test: test cpr-exec

Add a test for the cpr-exec migration mode.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1759332851-370353-20-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

tests/qtest/migration/cpr-tests.c

@@ -113,6 +113,138 @@ static void test_mode_transfer_defer(void)
     test_mode_transfer_common(true);
 }
 
+static void set_cpr_exec_args(QTestState *who, MigrateCommon *args)
+{
+    g_autofree char *qtest_from_args = NULL;
+    g_autofree char *from_args = NULL;
+    g_autofree char *to_args = NULL;
+    g_autofree char *exec_args = NULL;
+    g_auto(GStrv) argv = NULL;
+    char *from_str, *src, *dst;
+    int ret;
+
+    /*
+     * hide_stderr appends "2>/dev/null" to the command line, but cpr-exec
+     * passes the command-line words to execv, not to the shell, so suppress it
+     * here.  fd 2 was already bound in the source VM, and execv preserves it.
+     */
+    g_assert(args->start.hide_stderr == false);
+
+    ret = migrate_args(&from_args, &to_args, args->listen_uri, &args->start);
+    g_assert(!ret);
+    qtest_from_args = qtest_qemu_args(from_args);
+
+    /*
+     * The generated args may have been formatted using "%s %s" with empty
+     * strings, which can produce consecutive spaces, which g_strsplit would
+     * convert into empty strings.  Ditto for leading and trailing space.
+     * De-dup spaces to avoid that.
+     */
+
+    from_str = src = dst = g_strstrip(qtest_from_args);
+    do {
+        if (*src != ' ' || src[-1] != ' ') {
+            *dst++ = *src;
+        }
+    } while (*src++);
+
+    exec_args = g_strconcat(qtest_qemu_binary(migration_get_env()->qemu_dst),
+                            " -incoming defer ", from_str, NULL);
+    argv = g_strsplit(exec_args, " ", -1);
+    migrate_set_parameter_strv(who, "cpr-exec-command", argv);
+}
+
+static void wait_for_migration_event(QTestState *who, const char *waitfor)
+{
+    QDict *rsp, *data;
+    char *status;
+    bool done = false;
+
+    while (!done) {
+        rsp = qtest_qmp_eventwait_ref(who, "MIGRATION");
+        g_assert(qdict_haskey(rsp, "data"));
+        data = qdict_get_qdict(rsp, "data");
+        g_assert(qdict_haskey(data, "status"));
+        status = g_strdup(qdict_get_str(data, "status"));
+        g_assert(strcmp(status, "failed"));
+        done = !strcmp(status, waitfor);
+        qobject_unref(rsp);
+    }
+}
+
+static void test_cpr_exec(MigrateCommon *args)
+{
+    QTestState *from, *to;
+    void *data_hook = NULL;
+    g_autofree char *connect_uri = g_strdup(args->connect_uri);
+    g_autofree char *filename = g_strdup_printf("%s/%s", tmpfs,
+                                                FILE_TEST_FILENAME);
+
+    if (migrate_start(&from, NULL, args->listen_uri, &args->start)) {
+        return;
+    }
+
+    /* Source and dest never run concurrently */
+    g_assert_false(args->live);
+
+    if (args->start_hook) {
+        data_hook = args->start_hook(from, NULL);
+    }
+
+    wait_for_serial("src_serial");
+    set_cpr_exec_args(from, args);
+    migrate_set_capability(from, "events", true);
+    migrate_qmp(from, NULL, connect_uri, NULL, "{}");
+    wait_for_migration_event(from, "completed");
+
+    to = qtest_init_after_exec(from);
+
+    qtest_qmp_assert_success(to, "{ 'execute': 'migrate-incoming',"
+                             "  'arguments': { "
+                             "      'channels': [ { 'channel-type': 'main',"
+                             "      'addr': { 'transport': 'file',"
+                             "                'filename': %s,"
+                             "                'offset': 0  } } ] } }",
+                             filename);
+    wait_for_migration_complete(to);
+
+    wait_for_resume(to, get_dst());
+    /* Device on target is still named src_serial because args do not change */
+    wait_for_serial("src_serial");
+
+    if (args->end_hook) {
+        args->end_hook(from, to, data_hook);
+    }
+
+    migrate_end(from, to, args->result == MIG_TEST_SUCCEED);
+}
+
+static void *test_mode_exec_start(QTestState *from, QTestState *to)
+{
+    assert(!to);
+    migrate_set_parameter_str(from, "mode", "cpr-exec");
+    return NULL;
+}
+
+static void test_mode_exec(void)
+{
+    g_autofree char *uri = g_strdup_printf("file:%s/%s", tmpfs,
+                                           FILE_TEST_FILENAME);
+    g_autofree char *listen_uri = g_strdup_printf("defer");
+
+    MigrateCommon args = {
+        .start.only_source = true,
+        .start.opts_source = "-machine aux-ram-share=on -nodefaults",
+        .start.memory_backend = "-object memory-backend-memfd,id=pc.ram,size=%s"
+                                " -machine memory-backend=pc.ram",
+        .connect_uri = uri,
+        .listen_uri = listen_uri,
+        .start_hook = test_mode_exec_start,
+    };
+
+    test_cpr_exec(&args);
+}
+
 void migration_test_add_cpr(MigrationTestEnv *env)
 {
     tmpfs = env->tmpfs;
@@ -135,5 +267,6 @@ void migration_test_add_cpr(MigrationTestEnv *env)
         migration_test_add("/migration/mode/transfer", test_mode_transfer);
         migration_test_add("/migration/mode/transfer/defer",
                            test_mode_transfer_defer);
+        migration_test_add("/migration/mode/exec", test_mode_exec);
     }
 }