[kvm-unit-tests PATCH v4 7/7] s390x: ap: Add nq/dq len test

[Janosch Frank <frankja@linux.ibm.com>]

For years the nqap/dqap max length was 12KB but with a recent machine
extended message length support was introduced. The support is AP type
and generation specific, so it can vary from card to card which
complicates testing by a lot.

This test will use the APQN that all other tests use no matter if
there's extended length support or not. But if longer messages are
supported by the APQN we need to adapt our tests.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 lib/s390x/ap.h |   3 +-
 s390x/ap.c     | 103 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+), 1 deletion(-)

diff --git a/lib/s390x/ap.h b/lib/s390x/ap.h
index eecb39be..792149ea 100644
--- a/lib/s390x/ap.h
+++ b/lib/s390x/ap.h
@@ -77,7 +77,8 @@ struct pqap_r2 {
 	uint8_t pad_1[3];
 	uint8_t at;
 	uint8_t nd;
-	uint8_t pad_6;
+	uint8_t pad_6 : 4;
+	uint8_t ml : 4;
 	uint8_t pad_7 : 4;
 	uint8_t qd : 4;
 } __attribute__((packed))  __attribute__((aligned(8)));
diff --git a/s390x/ap.c b/s390x/ap.c
index 0f2d03c2..edb4943b 100644
--- a/s390x/ap.c
+++ b/s390x/ap.c
@@ -257,6 +257,106 @@ static void test_pgms_dqap(void)
 	report_prefix_pop();
 }
 
+/*
+ * For years the nqap/dqap max length was 12KB but with a recent
+ * machine extended message length support was introduced. The support
+ * is AP type and generation specific, so it can vary from card to
+ * card.
+ *
+ * This test will use the APQN that all other tests use no matter if
+ * there's extended length support or not. But if longer messages are
+ * supported by the APQN we need to adapt our tests.
+ */
+static void test_pgms_nqdq_len(void)
+{
+	struct ap_queue_status apqsw = {};
+	struct pqap_r2 r2 = {};
+	uint64_t len, mlen;
+	bool fail;
+	int i;
+
+	/* Extended message support is reported via tapq with T=1 */
+	ap_pqap_tapq(apn, qn, &apqsw, &r2, true);
+	/* < 3 means 3 because of backwards compatibility */
+	mlen = r2.ml ? r2.ml : 3;
+	/* Len is reported in pages */
+	mlen *= PAGE_SIZE;
+
+	report_prefix_push("nqap");
+	report_prefix_push("spec");
+
+	report_prefix_push("len + 1");
+	expect_pgm_int();
+	len = mlen + 1;
+	asm volatile (
+		"lg	5,  0(%[len])\n"
+		".insn	rre,0xb2ae0000,2,4\n"
+		: : [len] "a" (&len)
+		: "cc", "memory", "0", "1", "2", "3", "4", "5", "6", "7");
+	check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
+	report_prefix_pop();
+
+	report_prefix_push("len bits");
+	fail = false;
+	for (i = 12; i < 63; i++) {
+		len = BIT(i);
+		if (len < mlen)
+			continue;
+		expect_pgm_int();
+		asm volatile (
+			"lg	5,  0(%[len])\n"
+			".insn	rre,0xb2ae0000,2,4\n"
+			: : [len] "a" (&len)
+			: "cc", "memory", "0", "1", "2", "3", "4", "5", "6", "7");
+		if (clear_pgm_int() != PGM_INT_CODE_SPECIFICATION) {
+			report_fail("setting len to %lx did not result in a spec exception",
+				    len);
+			fail = true;
+		}
+	}
+	report(!fail, "length pgms");
+	report_prefix_pop();
+	report_prefix_pop();
+	report_prefix_pop();
+
+	report_prefix_push("dqap");
+	report_prefix_push("spec");
+
+	report_prefix_push("len + 1");
+	expect_pgm_int();
+	len = mlen + 1;
+	asm volatile (
+		"lg	5,  0(%[len])\n"
+		".insn	rre,0xb2ae0000,2,4\n"
+		: : [len] "a" (&len)
+		: "cc", "memory", "0", "1", "2", "3", "4", "5", "6", "7");
+	check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
+	report_prefix_pop();
+
+	report_prefix_push("len bits");
+	fail = false;
+	for (i = 12; i < 63; i++) {
+		len = BIT(i);
+		if (len < mlen)
+			continue;
+		expect_pgm_int();
+		asm volatile (
+			"lg	5,  0(%[len])\n"
+			".insn	rre,0xb2ae0000,2,4\n"
+			: : [len] "a" (&len)
+			: "cc", "memory", "0", "1", "2", "3", "4", "5", "6", "7");
+		if (clear_pgm_int() != PGM_INT_CODE_SPECIFICATION) {
+			report_fail("setting len to %lx did not result in a spec exception",
+				    len);
+			fail = true;
+		}
+	}
+	report(!fail, "length pgms");
+	report_prefix_pop();
+	report_prefix_pop();
+	report_prefix_pop();
+}
+
 static void test_priv(void)
 {
 	struct ap_config_info info = {};
@@ -446,6 +546,9 @@ int main(void)
 	}
 	apn = apns[0];
 	qn = qns[0];
+
+	test_pgms_nqdq_len();
+
 	report_prefix_push("pqap");
 	if (test_facility(65)) {
 		test_pqap_aqic();
-- 
2.40.1