[kvm-unit-tests PATCH v4 3/3] s390x: Test effect of storage keys on diag 308

[Janis Schoetterl-Glausch <scgl@linux.ibm.com>]

Test that key-controlled protection does not apply to diag 308.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 s390x/skey.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/s390x/skey.c b/s390x/skey.c
index 36b81cec..87418f19 100644
--- a/s390x/skey.c
+++ b/s390x/skey.c
@@ -305,6 +305,31 @@ static void test_store_cpu_address(void)
 	report_prefix_pop();
 }
 
+static void test_diag_308(void)
+{
+	uint16_t response;
+	uint32_t *ipib = (uint32_t *)pagebuf;
+
+	report_prefix_push("DIAG 308");
+	WRITE_ONCE(ipib[0], 0); /* Invalid length */
+	set_storage_key(ipib, 0x28, 0);
+	/* key-controlled protection does not apply */
+	asm volatile (
+		"lr	%%r2,%[ipib]\n\t"
+		"spka	0x10\n\t"
+		"diag	%%r2,%[code],0x308\n\t"
+		"spka	0\n\t"
+		"lr	%[response],%%r3\n"
+		: [response] "=d" (response)
+		: [ipib] "d" (ipib),
+		  [code] "d" (5)
+		: "%r2", "%r3"
+	);
+	report(response == 0x402, "no exception on fetch, response: invalid IPIB");
+	set_storage_key(ipib, 0x00, 0);
+	report_prefix_pop();
+}
+
 /*
  * Perform CHANNEL SUBSYSTEM CALL (CHSC)  instruction while temporarily executing
  * with access key 1.
@@ -717,6 +742,7 @@ int main(void)
 	test_chg();
 	test_test_protection();
 	test_store_cpu_address();
+	test_diag_308();
 	test_channel_subsystem_call();
 
 	setup_vm();
-- 
2.33.1