[PATCH v3 5/6] tests/qtest: migration: Add support for negative testing of qmp_migrate

[Fabiano Rosas <farosas@suse.de>]

There is currently no way to write a test for errors that happened in
qmp_migrate before the migration has started.

Add a version of qmp_migrate that ensures an error happens. To make
use of it a test needs to set MigrateCommon.result as
MIG_TEST_QMP_ERROR.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 tests/qtest/libqtest.c          | 33 +++++++++++++++++++++++++++++++++
 tests/qtest/libqtest.h          | 28 ++++++++++++++++++++++++++++
 tests/qtest/migration-helpers.c | 20 ++++++++++++++++++++
 tests/qtest/migration-helpers.h |  3 +++
 tests/qtest/migration-test.c    | 16 ++++++++++++----
 5 files changed, 96 insertions(+), 4 deletions(-)

diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
index 79152f0ec3..011ed255fa 100644
--- a/tests/qtest/libqtest.c
+++ b/tests/qtest/libqtest.c
@@ -1248,6 +1248,28 @@ void qtest_memset(QTestState *s, uint64_t addr, uint8_t pattern, size_t size)
     qtest_rsp(s);
 }
 
+QDict *qtest_vqmp_assert_failure_ref(QTestState *qts,
+                                     const char *fmt, va_list args)
+{
+    QDict *response;
+    QDict *ret;
+
+    response = qtest_vqmp(qts, fmt, args);
+
+    g_assert(response);
+    if (!qdict_haskey(response, "error")) {
+        g_autoptr(GString) s = qobject_to_json_pretty(QOBJECT(response), true);
+        g_test_message("%s", s->str);
+    }
+    g_assert(qdict_haskey(response, "error"));
+    g_assert(!qdict_haskey(response, "return"));
+    ret = qdict_get_qdict(response, "error");
+    qobject_ref(ret);
+    qobject_unref(response);
+
+    return ret;
+}
+
 QDict *qtest_vqmp_assert_success_ref(QTestState *qts,
                                      const char *fmt, va_list args)
 {
@@ -1310,6 +1332,17 @@ void qtest_vqmp_fds_assert_success(QTestState *qts, int *fds, size_t nfds,
 }
 #endif /* !_WIN32 */
 
+QDict *qtest_qmp_assert_failure_ref(QTestState *qts, const char *fmt, ...)
+{
+    QDict *response;
+    va_list ap;
+
+    va_start(ap, fmt);
+    response = qtest_vqmp_assert_failure_ref(qts, fmt, ap);
+    va_end(ap);
+    return response;
+}
+
 QDict *qtest_qmp_assert_success_ref(QTestState *qts, const char *fmt, ...)
 {
     QDict *response;
diff --git a/tests/qtest/libqtest.h b/tests/qtest/libqtest.h
index 913acc3d5c..7ef19ce3ff 100644
--- a/tests/qtest/libqtest.h
+++ b/tests/qtest/libqtest.h
@@ -799,6 +799,34 @@ void qtest_vqmp_fds_assert_success(QTestState *qts, int *fds, size_t nfds,
     G_GNUC_PRINTF(4, 0);
 #endif /* !_WIN32 */
 
+/**
+ * qtest_qmp_assert_failure_ref:
+ * @qts: QTestState instance to operate on
+ * @fmt: QMP message to send to qemu, formatted like
+ * qobject_from_jsonf_nofail().  See parse_interpolation() for what's
+ * supported after '%'.
+ *
+ * Sends a QMP message to QEMU, asserts that an 'error' key is present in
+ * the response, and returns the response.
+ */
+QDict *qtest_qmp_assert_failure_ref(QTestState *qts, const char *fmt, ...)
+    G_GNUC_PRINTF(2, 3);
+
+/**
+ * qtest_vqmp_assert_failure_ref:
+ * @qts: QTestState instance to operate on
+ * @fmt: QMP message to send to qemu, formatted like
+ * qobject_from_jsonf_nofail().  See parse_interpolation() for what's
+ * supported after '%'.
+ * @args: variable arguments for @fmt
+ *
+ * Sends a QMP message to QEMU, asserts that an 'error' key is present in
+ * the response, and returns the response.
+ */
+QDict *qtest_vqmp_assert_failure_ref(QTestState *qts,
+                                     const char *fmt, va_list args)
+    G_GNUC_PRINTF(2, 0);
+
 /**
  * qtest_qmp_assert_success_ref:
  * @qts: QTestState instance to operate on
diff --git a/tests/qtest/migration-helpers.c b/tests/qtest/migration-helpers.c
index 08f5ee1179..0c185db450 100644
--- a/tests/qtest/migration-helpers.c
+++ b/tests/qtest/migration-helpers.c
@@ -49,6 +49,26 @@ bool migrate_watch_for_resume(QTestState *who, const char *name,
     return false;
 }
 
+void migrate_qmp_fail(QTestState *who, const char *uri, const char *fmt, ...)
+{
+    va_list ap;
+    QDict *args, *err;
+
+    va_start(ap, fmt);
+    args = qdict_from_vjsonf_nofail(fmt, ap);
+    va_end(ap);
+
+    g_assert(!qdict_haskey(args, "uri"));
+    qdict_put_str(args, "uri", uri);
+
+    err = qtest_qmp_assert_failure_ref(
+        who, "{ 'execute': 'migrate', 'arguments': %p}", args);
+
+    g_assert(qdict_haskey(err, "desc"));
+
+    qobject_unref(err);
+}
+
 /*
  * Send QMP command "migrate".
  * Arguments are built from @fmt... (formatted like
diff --git a/tests/qtest/migration-helpers.h b/tests/qtest/migration-helpers.h
index 57d295a4fe..4f51d0f8bc 100644
--- a/tests/qtest/migration-helpers.h
+++ b/tests/qtest/migration-helpers.h
@@ -27,6 +27,9 @@ G_GNUC_PRINTF(3, 4)
 void migrate_incoming_qmp(QTestState *who, const char *uri,
                           const char *fmt, ...);
 
+G_GNUC_PRINTF(3, 4)
+void migrate_qmp_fail(QTestState *who, const char *uri, const char *fmt, ...);
+
 void migrate_set_capability(QTestState *who, const char *capability,
                             bool value);
 
diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index c4140ac3f1..2fdf6a115e 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -564,6 +564,8 @@ typedef struct {
         MIG_TEST_FAIL,
         /* This test should fail, dest qemu should fail with abnormal status */
         MIG_TEST_FAIL_DEST_QUIT_ERR,
+        /* The QMP command for this migration should fail with an error */
+        MIG_TEST_QMP_ERROR,
     } result;
 
     /* Optional: set number of migration passes to wait for, if live==true */
@@ -1379,6 +1381,7 @@ static void test_precopy_common(MigrateCommon *args)
 {
     QTestState *from, *to;
     void *data_hook = NULL;
+    g_autofree char *connect_uri = NULL;
 
     if (test_migrate_start(&from, &to, args->listen_uri, &args->start)) {
         return;
@@ -1419,13 +1422,17 @@ static void test_precopy_common(MigrateCommon *args)
     }
 
     if (!args->connect_uri) {
-        g_autofree char *local_connect_uri =
-            migrate_get_socket_address(to, "socket-address");
-        migrate_qmp(from, local_connect_uri, "{}");
+        connect_uri = migrate_get_socket_address(to, "socket-address");
     } else {
-        migrate_qmp(from, args->connect_uri, "{}");
+        connect_uri = g_strdup(args->connect_uri);
     }
 
+    if (args->result == MIG_TEST_QMP_ERROR) {
+        migrate_qmp_fail(from, connect_uri, "{}");
+        goto finish;
+    }
+
+    migrate_qmp(from, connect_uri, "{}");
 
     if (args->result != MIG_TEST_SUCCEED) {
         bool allow_active = args->result == MIG_TEST_FAIL;
@@ -1474,6 +1481,7 @@ static void test_precopy_common(MigrateCommon *args)
         wait_for_serial("dest_serial");
     }
 
+finish:
     if (args->finish_hook) {
         args->finish_hook(from, to, data_hook);
     }
-- 
2.35.3