[kvm-unit-tests PATCH v2 2/5] s390x: Test specification exceptions during transaction

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

Program interruptions during transactional execution cause other
interruption codes.
Check that we see the expected code for (some) specification exceptions.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
---
 lib/s390x/asm/arch_def.h |   1 +
 s390x/spec_ex.c          | 175 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 171 insertions(+), 5 deletions(-)

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index 302ef1f..665a4b2 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -235,6 +235,7 @@ static inline uint64_t stctg(int cr)
 	return value;
 }
 
+#define CTL0_TRANSACT_EX_CTL	(63 -  8)
 #define CTL0_LOW_ADDR_PROT	(63 - 35)
 #define CTL0_EDAT		(63 - 40)
 #define CTL0_IEP		(63 - 43)
diff --git a/s390x/spec_ex.c b/s390x/spec_ex.c
index dd0ee53..eaf48f4 100644
--- a/s390x/spec_ex.c
+++ b/s390x/spec_ex.c
@@ -4,9 +4,14 @@
  *
  * Specification exception test.
  * Tests that specification exceptions occur when expected.
+ * This includes specification exceptions occurring during transactional execution
+ * as these result in another interruption code (the transactional-execution-aborted
+ * bit is set).
  */
 #include <stdlib.h>
+#include <htmintrin.h>
 #include <libcflat.h>
+#include <asm/barrier.h>
 #include <asm/interrupt.h>
 #include <asm/facility.h>
 
@@ -91,18 +96,23 @@ static void not_even(void)
 struct spec_ex_trigger {
 	const char *name;
 	void (*func)(void);
+	bool transactable;
 	void (*fixup)(void);
 };
 
 static const struct spec_ex_trigger spec_ex_triggers[] = {
-	{ "psw_bit_12_is_1", &psw_bit_12_is_1, &fixup_invalid_psw},
-	{ "bad_alignment", &bad_alignment, NULL},
-	{ "not_even", &not_even, NULL},
-	{ NULL, NULL, NULL},
+	{ "psw_bit_12_is_1", &psw_bit_12_is_1, false, &fixup_invalid_psw},
+	{ "bad_alignment", &bad_alignment, true, NULL},
+	{ "not_even", &not_even, true, NULL},
+	{ NULL, NULL, true, NULL},
 };
 
 struct args {
 	uint64_t iterations;
+	uint64_t max_retries;
+	uint64_t suppress_info;
+	uint64_t max_failures;
+	bool diagnose;
 };
 
 static void test_spec_ex(struct args *args,
@@ -132,14 +142,135 @@ static void test_spec_ex(struct args *args,
 	       expected_pgm);
 }
 
+#define TRANSACTION_COMPLETED 4
+#define TRANSACTION_MAX_RETRIES 5
+
+/* NULL must be passed to __builtin_tbegin via constant, forbid diagnose from
+ * being NULL to keep things simple
+ */
+static int __attribute__((nonnull))
+with_transaction(void (*trigger)(void), struct __htm_tdb *diagnose)
+{
+	int cc;
+
+	cc = __builtin_tbegin(diagnose);
+	if (cc == _HTM_TBEGIN_STARTED) {
+		trigger();
+		__builtin_tend();
+		return -TRANSACTION_COMPLETED;
+	} else {
+		return -cc;
+	}
+}
+
+static int retry_transaction(const struct spec_ex_trigger *trigger, unsigned int max_retries,
+			     struct __htm_tdb *tdb, uint16_t expected_pgm)
+{
+	int trans_result, i;
+	uint16_t pgm;
+
+	for (i = 0; i < max_retries; i++) {
+		expect_pgm_int();
+		trans_result = with_transaction(trigger->func, tdb);
+		if (trans_result == -_HTM_TBEGIN_TRANSIENT) {
+			mb();
+			pgm = lc->pgm_int_code;
+			if (pgm == 0)
+				continue;
+			else if (pgm == expected_pgm)
+				return 0;
+		}
+		return trans_result;
+	}
+	return -TRANSACTION_MAX_RETRIES;
+}
+
+static void test_spec_ex_trans(struct args *args, const struct spec_ex_trigger *trigger)
+{
+	const uint16_t expected_pgm = PGM_INT_CODE_SPECIFICATION
+			      | PGM_INT_CODE_TX_ABORTED_EVENT;
+	union {
+		struct __htm_tdb tdb;
+		uint64_t dwords[sizeof(struct __htm_tdb) / sizeof(uint64_t)];
+	} diag;
+	unsigned int i, failures = 0;
+	int trans_result;
+
+	if (!test_facility(73)) {
+		report_skip("transactional-execution facility not installed");
+		return;
+	}
+	ctl_set_bit(0, CTL0_TRANSACT_EX_CTL); /* enable transactional-exec */
+
+	for (i = 0; i < args->iterations && failures <= args->max_failures; i++) {
+		register_pgm_cleanup_func(trigger->fixup);
+		trans_result = retry_transaction(trigger, args->max_retries, &diag.tdb, expected_pgm);
+		register_pgm_cleanup_func(NULL);
+		switch (trans_result) {
+		case 0:
+			continue;
+		case -_HTM_TBEGIN_INDETERMINATE:
+		case -_HTM_TBEGIN_PERSISTENT:
+			if (failures < args->suppress_info)
+				report_info("transaction failed with cc %d",
+					    -trans_result);
+			break;
+		case -_HTM_TBEGIN_TRANSIENT:
+			report(0,
+			       "Program interrupt: expected(%d) == received(%d)",
+			       expected_pgm,
+			       clear_pgm_int());
+			goto out;
+		case -TRANSACTION_COMPLETED:
+			report(0,
+			       "Transaction completed without exception");
+			goto out;
+		case -TRANSACTION_MAX_RETRIES:
+			if (failures < args->suppress_info)
+				report_info("Retried transaction %lu times without exception",
+					    args->max_retries);
+			break;
+		default:
+			report(0, "Invalid return transaction result");
+			goto out;
+		}
+
+		if (failures < args->suppress_info)
+			report_info("transaction abort code: %llu", diag.tdb.abort_code);
+		if (args->diagnose && failures < args->suppress_info) {
+			for (i = 0; i < 32; i++)
+				report_info("diag+%03d: %016lx", i*8, diag.dwords[i]);
+		}
+		++failures;
+	}
+	if (failures <= args->max_failures) {
+		report(1,
+		       "Program interrupt: always expected(%d) == received(%d), transaction failures: %u",
+		       expected_pgm,
+		       expected_pgm,
+		       failures);
+	} else {
+		report(0,
+		       "Too many transaction failures: %u", failures);
+	}
+	if (failures > args->suppress_info)
+		report_info("Suppressed some transaction failure information messages");
+
+out:
+	ctl_clear_bit(0, CTL0_TRANSACT_EX_CTL);
+}
+
 static struct args parse_args(int argc, char **argv)
 {
 	struct args args = {
 		.iterations = 1,
+		.max_retries = 20,
+		.suppress_info = 20,
+		.diagnose = false
 	};
 	unsigned int i;
 	long arg;
-	bool no_arg;
+	bool no_arg, max_failures = false;
 	char *end;
 
 	for (i = 1; i < argc; i++) {
@@ -156,11 +287,35 @@ static struct args parse_args(int argc, char **argv)
 				report_abort("--iterations needs a positive parameter");
 			args.iterations = arg;
 			++i;
+		} else if (!strcmp("--max-retries", argv[i])) {
+			if (no_arg)
+				report_abort("--max-retries needs a positive parameter");
+			args.max_retries = arg;
+			++i;
+		} else if (!strcmp("--suppress-info", argv[i])) {
+			if (no_arg)
+				report_abort("--suppress-info needs a positive parameter");
+			args.suppress_info = arg;
+			++i;
+		} else if (!strcmp("--max-failures", argv[i])) {
+			if (no_arg)
+				report_abort("--max-failures needs a positive parameter");
+			args.max_failures = arg;
+			max_failures = true;
+			++i;
+		} else if (!strcmp("--diagnose", argv[i])) {
+			args.diagnose = true;
+		} else if (!strcmp("--no-diagnose", argv[i])) {
+			args.diagnose = false;
 		} else {
 			report_abort("Unsupported parameter '%s'",
 				     argv[i]);
 		}
 	}
+
+	if (!max_failures)
+		args.max_failures = args.iterations / 1000;
+
 	return args;
 }
 
@@ -178,5 +333,15 @@ int main(int argc, char **argv)
 	}
 	report_prefix_pop();
 
+	report_prefix_push("specification exception during transaction");
+	for (i = 0; spec_ex_triggers[i].name; i++) {
+		if (spec_ex_triggers[i].transactable) {
+			report_prefix_push(spec_ex_triggers[i].name);
+			test_spec_ex_trans(&args, &spec_ex_triggers[i]);
+			report_prefix_pop();
+		}
+	}
+	report_prefix_pop();
+
 	return report_summary();
 }
-- 
2.31.1