qapi: Implement deprecated-input=reject for QMP command arguments

This policy rejects deprecated input, and thus permits "testing the
future".  Implement it for QMP command arguments: reject commands with
deprecated ones.  Example: when QEMU is run with -compat
deprecated-input=reject, then

    {"execute": "eject", "arguments": {"device": "cd"}}

fails like this

    {"error": {"class": "GenericError", "desc": "Deprecated parameter 'device' disabled by policy"}}

When the deprecated parameter is removed, the error will change to

    {"error": {"class": "GenericError", "desc": "Parameter 'device' is unexpected"}}

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-11-armbru@redhat.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/tests/unit/test-qmp-cmds.c b/tests/unit/test-qmp-cmds.c
index cba982154b..266db074b4 100644
--- a/tests/unit/test-qmp-cmds.c
+++ b/tests/unit/test-qmp-cmds.c
@@ -303,6 +303,29 @@ static void test_dispatch_cmd_deprecated(void)
     do_qmp_dispatch_error(false, ERROR_CLASS_COMMAND_NOT_FOUND, cmd);
 }
 
+static void test_dispatch_cmd_arg_deprecated(void)
+{
+    const char *cmd = "{ 'execute': 'test-features0',"
+        " 'arguments': { 'fs1': { 'foo': 42 } } }";
+    QDict *ret;
+
+    memset(&compat_policy, 0, sizeof(compat_policy));
+
+    /* accept */
+    ret = qobject_to(QDict, do_qmp_dispatch(false, cmd));
+    assert(ret && qdict_size(ret) == 1);
+    qobject_unref(ret);
+
+    compat_policy.has_deprecated_input = true;
+    compat_policy.deprecated_input = COMPAT_POLICY_INPUT_ACCEPT;
+    ret = qobject_to(QDict, do_qmp_dispatch(false, cmd));
+    assert(ret && qdict_size(ret) == 1);
+    qobject_unref(ret);
+
+    compat_policy.deprecated_input = COMPAT_POLICY_INPUT_REJECT;
+    do_qmp_dispatch_error(false, ERROR_CLASS_GENERIC_ERROR, cmd);
+}
+
 static void test_dispatch_cmd_ret_deprecated(void)
 {
     const char *cmd = "{ 'execute': 'test-features0' }";
@@ -403,6 +426,8 @@ int main(int argc, char **argv)
                     test_dispatch_cmd_success_response);
     g_test_add_func("/qmp/dispatch_cmd_deprecated",
                     test_dispatch_cmd_deprecated);
+    g_test_add_func("/qmp/dispatch_cmd_arg_deprecated",
+                    test_dispatch_cmd_arg_deprecated);
     g_test_add_func("/qmp/dispatch_cmd_ret_deprecated",
                     test_dispatch_cmd_ret_deprecated);
     g_test_add_func("/qmp/dealloc_types", test_dealloc_types);