tests/tcg/aarch64: add system test for FEAT_XS

Add system test to make sure FEAT_XS is enabled for max cpu emulation
and that QEMU doesn't crash when encountering an NXS instruction
variant.

Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20241211144440.2700268-7-peter.maydell@linaro.org
[PMM: In ISAR field test, mask with 0xf, not 0xff; use < rather
 than an equality test to follow the standard ID register field
 check guidelines]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/tests/tcg/aarch64/system/feat-xs.c b/tests/tcg/aarch64/system/feat-xs.c
new file mode 100644 (file)
index 0000000..f310fc8
--- /dev/null
+++ b/tests/tcg/aarch64/system/feat-xs.c
@@ -0,0 +1,27 @@
+/*
+ * FEAT_XS Test
+ *
+ * Copyright (c) 2024 Linaro Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <minilib.h>
+#include <stdint.h>
+
+int main(void)
+{
+    uint64_t isar1;
+
+    asm volatile ("mrs %0, id_aa64isar1_el1" : "=r"(isar1));
+    if (((isar1 >> 56) & 0xf) < 1) {
+        ml_printf("FEAT_XS not supported by CPU");
+        return 1;
+    }
+    /* VMALLE1NXS */
+    asm volatile (".inst 0xd508971f");
+    /* VMALLE1OSNXS */
+    asm volatile (".inst 0xd508911f");
+
+    return 0;
+}