tests/tcg/aarch64: Add test case for SME2 gdbstub registers

Test the SME2 register exposure over gdbstub, in the same way
we already do for SME.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20251017153027.969016-4-peter.maydell@linaro.org

tests/tcg/aarch64/Makefile.target

@@ -164,7 +164,14 @@ run-gdbstub-sysregs-sme-tile-slice: sysregs
 	"selected gdb ($(GDB)) does not support SME ZA tile slices")
 endif
 
-EXTRA_RUNS += run-gdbstub-sysregs-sme run-gdbstub-sysregs-sme-tile-slice
+run-gdbstub-sysregs-sme2: sysregs
+	$(call run-test, $@, $(GDB_SCRIPT) \
+		--gdb $(GDB) \
+		--qemu $(QEMU) --qargs "$(QEMU_OPTS)" \
+		--bin $< --test $(AARCH64_SRC)/gdbstub/test-sme2.py, \
+	gdbstub SME ZA tile slice support)
+
+EXTRA_RUNS += run-gdbstub-sysregs-sme run-gdbstub-sysregs-sme-tile-slice run-gdbstub-sysregs-sme2
 
 endif
 

tests/tcg/aarch64/gdbstub/test-sme2.py

@@ -0,0 +1,36 @@
+#
+# Copyright (C) 2025 Linaro Ltd.
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+#
+# Test the SME2 registers are visible and changeable via gdbstub
+#
+# This is launched via tests/guest-debug/run-test.py
+#
+
+import gdb
+from test_gdbstub import main, report
+
+
+def run_test():
+    """Test reads and writes of the SME2 registers"""
+    frame = gdb.selected_frame()
+    rname = "zt0"
+    zt0 = frame.read_register(rname)
+    report(True, "Reading %s" % rname)
+
+    # Writing to the ZT0 register, byte by byte.
+    for i in range(0, 64):
+        cmd = "set $zt0[%d] = 0x01" % (i)
+        gdb.execute(cmd)
+        report(True, "%s" % cmd)
+
+    # Reading from the ZT0 register, byte by byte.
+    for i in range(0, 64):
+        reg = "$zt0[%d]" % (i)
+        v = gdb.parse_and_eval(reg)
+        report(str(v.type) == "uint8_t", "size of %s" % (reg))
+        report(v == 0x1, "%s is 0x%x" % (reg, 0x1))
+
+main(run_test, expected_arch="aarch64")