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

Janis Schoetterl-Glausch
2021-10-05T09:09:39Z

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