tests/qtest: Make qtest_has_accel() generic

Since commit b14a0b7469 ("accel: Use QOM classes for accel types")
accelerators are registered as QOM objects. Use QOM as a generic
API to query for available accelerators. This is in particular
useful to query hardware accelerators such HFV, Xen or WHPX which
otherwise have their definitions poisoned in "exec/poison.h".

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20250130103728.536-3-philmd@linaro.org>
Signed-off-by: Fabiano Rosas <farosas@suse.de>

tests/qtest/libqtest.c

@@ -30,6 +30,7 @@
 
 #include "libqtest.h"
 #include "libqmp.h"
+#include "qemu/accel.h"
 #include "qemu/ctype.h"
 #include "qemu/cutils.h"
 #include "qemu/sockets.h"
@@ -1063,13 +1064,10 @@ static bool qtest_qom_has_concrete_type(const char *parent_typename,
 
 bool qtest_has_accel(const char *accel_name)
 {
-    if (g_str_equal(accel_name, "tcg")) {
-#if defined(CONFIG_TCG)
-        return true;
-#else
-        return false;
-#endif
-    } else if (g_str_equal(accel_name, "kvm")) {
+    static QList *list;
+    g_autofree char *accel_type = NULL;
+
+    if (g_str_equal(accel_name, "kvm")) {
         int i;
         const char *arch = qtest_get_arch();
         const char *targets[] = { CONFIG_KVM_TARGETS };
@@ -1081,11 +1079,12 @@ bool qtest_has_accel(const char *accel_name)
                 }
             }
         }
-    } else {
-        /* not implemented */
-        g_assert_not_reached();
+        return false;
     }
-    return false;
+
+    accel_type = g_strconcat(accel_name, ACCEL_CLASS_SUFFIX, NULL);
+
+    return qtest_qom_has_concrete_type("accel", accel_type, &list);
 }
 
 bool qtest_get_irq(QTestState *s, int num)