tests/qtest: Add a function that checks whether a device is available

Devices might not always be compiled into the QEMU target binaries.
We already have the libqos framework that is good for handling such
situations, but some of the qtests are not a real good fit for the
libqos framework. Let's add a qtest_has_device() function for such
tests instead.

Message-Id: <20211220081054.151515-2-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
index a68326caae..41f4da4e54 100644
--- a/tests/qtest/libqtest.c
+++ b/tests/qtest/libqtest.c
@@ -1418,6 +1418,50 @@ bool qtest_has_machine(const char *machine)
     return false;
 }
 
+bool qtest_has_device(const char *device)
+{
+    static QList *list;
+    const QListEntry *p;
+    QObject *qobj;
+    QString *qstr;
+    QDict *devinfo;
+    int idx;
+
+    if (!list) {
+        QDict *resp;
+        QDict *args;
+        QTestState *qts = qtest_init("-machine none");
+
+        args = qdict_new();
+        qdict_put_bool(args, "abstract", false);
+        qdict_put_str(args, "implements", "device");
+
+        resp = qtest_qmp(qts, "{'execute': 'qom-list-types', 'arguments': %p }",
+                         args);
+        g_assert(qdict_haskey(resp, "return"));
+        list = qdict_get_qlist(resp, "return");
+        qobject_ref(list);
+        qobject_unref(resp);
+
+        qtest_quit(qts);
+    }
+
+    for (p = qlist_first(list), idx = 0; p; p = qlist_next(p), idx++) {
+        devinfo = qobject_to(QDict, qlist_entry_obj(p));
+        g_assert(devinfo);
+
+        qobj = qdict_get(devinfo, "name");
+        g_assert(qobj);
+        qstr = qobject_to(QString, qobj);
+        g_assert(qstr);
+        if (g_str_equal(qstring_get_str(qstr), device)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 /*
  * Generic hot-plugging test via the device_add QMP commands.
  */