[kvm-unit-tests PATCH v1] s390x/skey: Test for ADDRESSING exceptions

[David Hildenbrand <david@redhat.com>]

... used to be broken in TCG, so let's add a very simple test for SSKE
and ISKE. In order to test RRBE as well, introduce a helper to call the
machine instruction.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 lib/s390x/asm/mem.h | 12 ++++++++++++
 s390x/skey.c        | 28 ++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/lib/s390x/asm/mem.h b/lib/s390x/asm/mem.h
index 40b22b6..845c00c 100644
--- a/lib/s390x/asm/mem.h
+++ b/lib/s390x/asm/mem.h
@@ -50,6 +50,18 @@ static inline unsigned char get_storage_key(void *addr)
 	return skey;
 }
 
+static inline unsigned char reset_reference_bit(void *addr)
+{
+	int cc;
+
+	asm volatile(
+		"rrbe	0,%1\n"
+		"ipm	%0\n"
+		"srl	%0,28\n"
+		: "=d" (cc) : "a" (addr) : "cc");
+	return cc;
+}
+
 #define PFMF_FSC_4K 0
 #define PFMF_FSC_1M 1
 #define PFMF_FSC_2G 2
diff --git a/s390x/skey.c b/s390x/skey.c
index 2539944..58a5543 100644
--- a/s390x/skey.c
+++ b/s390x/skey.c
@@ -120,6 +120,33 @@ static void test_priv(void)
 	report_prefix_pop();
 }
 
+static void test_invalid_address(void)
+{
+	void *inv_addr = (void *)-1ull;
+
+	report_prefix_push("invalid address");
+
+	report_prefix_push("sske");
+	expect_pgm_int();
+	set_storage_key(inv_addr, 0, 0);
+	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
+	report_prefix_pop();
+
+	report_prefix_push("iske");
+	expect_pgm_int();
+	get_storage_key(inv_addr);
+	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
+	report_prefix_pop();
+
+	report_prefix_push("rrbe");
+	expect_pgm_int();
+	reset_reference_bit(inv_addr);
+	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
+	report_prefix_pop();
+
+	report_prefix_pop();
+}
+
 int main(void)
 {
 	report_prefix_push("skey");
@@ -128,6 +155,7 @@ int main(void)
 		goto done;
 	}
 	test_priv();
+	test_invalid_address();
 	test_set();
 	test_set_mb();
 	test_chg();
-- 
2.31.1