KVM: s390: selftest: memop: Add bad address test

Add a test that tries a real write to a bad address.
The existing CHECK_ONLY test doesn't cover all paths.
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20230206164602.138068-5-scgl@linux.ibm.com
Message-Id: <20230206164602.138068-5-scgl@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

tools/testing/selftests/kvm/s390x/memop.c

@@ -641,7 +641,9 @@ static void _test_errors_common(struct test_info info, enum mop_target target, i
 
 	/* Bad guest address: */
 	rv = ERR_MOP(info, target, WRITE, mem1, size, GADDR((void *)~0xfffUL), CHECK_ONLY);
-	TEST_ASSERT(rv > 0, "ioctl does not report bad guest memory access");
+	TEST_ASSERT(rv > 0, "ioctl does not report bad guest memory address with CHECK_ONLY");
+	rv = ERR_MOP(info, target, WRITE, mem1, size, GADDR((void *)~0xfffUL));
+	TEST_ASSERT(rv > 0, "ioctl does not report bad guest memory address on write");
 
 	/* Bad host address: */
 	rv = ERR_MOP(info, target, WRITE, 0, size, GADDR_V(mem1));