s390x/spec_ex.c - kvm-unit-tests - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright IBM Corp. 2021, 2022
  *
  * 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).
  *
  * Can be extended by adding triggers to spec_ex_triggers, see comments below.
  */
 #include <stdlib.h>
 #include <htmintrin.h>
 #include <libcflat.h>
 #include <bitops.h>
 #include <asm/barrier.h>
 #include <asm/interrupt.h>
 #include <asm/facility.h>

 /* toggled to signal occurrence of invalid psw fixup */
 static bool invalid_psw_expected;
 static struct psw expected_psw;
 static struct psw invalid_psw;
 static struct psw fixup_psw;

 /*
  * The standard program exception handler cannot deal with invalid old PSWs,
  * especially not invalid instruction addresses, as in that case one cannot
  * find the instruction following the faulting one from the old PSW.
  * The PSW to return to is set by load_psw.
  */
 static void fixup_invalid_psw(struct stack_frame_int *stack)
 {
 	assert_msg(invalid_psw_expected,
 		   "Unexpected invalid PSW during program interrupt fixup: %#lx %#lx",
 		   lowcore.pgm_old_psw.mask, lowcore.pgm_old_psw.addr);
 	/* signal occurrence of invalid psw fixup */
 	invalid_psw_expected = false;
 	invalid_psw = lowcore.pgm_old_psw;
 	lowcore.pgm_old_psw = fixup_psw;
 }

 /*
  * Load possibly invalid psw, but setup fixup_psw before,
  * so that fixup_invalid_psw() can bring us back onto the right track.
  * Also acts as compiler barrier, -> none required in expect/check_invalid_psw
  */
 static void load_psw(struct psw psw)
 {
 	uint64_t scratch;

 	/*
 	 * The fixup psw is the current psw with the instruction address replaced
 	 * by the address of the nop following the instruction loading the new psw.
 	 */
 	fixup_psw.mask = extract_psw_mask();
 	asm volatile ( "larl	%[scratch],0f\n"
 		"	stg	%[scratch],%[fixup_addr]\n"
 		"	lpswe	%[psw]\n"
 		"0:	nop\n"
 		: [scratch] "=&d" (scratch),
 		  [fixup_addr] "=&T" (fixup_psw.addr)
 		: [psw] "Q" (psw)
 		: "cc", "memory"
 	);
 }

 static void load_short_psw(struct short_psw psw)
 {
 	uint64_t scratch;

 	fixup_psw.mask = extract_psw_mask();
 	asm volatile ( "larl	%[scratch],0f\n"
 		"	stg	%[scratch],%[fixup_addr]\n"
 		"	lpsw	%[psw]\n"
 		"0:	nop\n"
 		: [scratch] "=&d" (scratch),
 		  [fixup_addr] "=&T" (fixup_psw.addr)
 		: [psw] "Q" (psw)
 		: "cc", "memory"
 	);
 }

 static void expect_invalid_psw(struct psw psw)
 {
 	expected_psw = psw;
 	invalid_psw_expected = true;
 }

 static int check_invalid_psw(void)
 {
 	/* Since the fixup sets this to false we check for false here. */
 	if (!invalid_psw_expected) {
 		if (expected_psw.mask == invalid_psw.mask &&
 		    expected_psw.addr == invalid_psw.addr)
 			return 0;
 		report_fail("Wrong invalid PSW");
 	} else {
 		report_fail("Expected exception due to invalid PSW");
 	}
 	return 1;
 }

 /* For normal PSWs bit 12 has to be 0 to be a valid PSW*/
 static int psw_bit_12_is_1(void)
 {
 	struct psw invalid = {
 		.mask = BIT(63 - 12),
 		.addr = 0x00000000deadbeee
 	};

 	expect_invalid_psw(invalid);
 	load_psw(invalid);
 	return check_invalid_psw();
 }

 /* A short PSW needs to have bit 12 set to be valid. */
 static int short_psw_bit_12_is_0(void)
 {
 	struct psw invalid = {
 		.mask = BIT(63 - 12),
 		.addr = 0x00000000deadbeee
 	};
 	struct short_psw short_invalid = {
 		.mask = 0x0,
 		.addr = 0xdeadbeee
 	};

 	expect_invalid_psw(invalid);
 	load_short_psw(short_invalid);
 	/*
 	 * lpsw may optionally check bit 12 before loading the new psw
 	 * -> cannot check the expected invalid psw like with lpswe
 	 */
 	return 0;
 }

 static int bad_alignment(void)
 {
 	uint32_t words[5] __attribute__((aligned(16)));
 	uint32_t (*bad_aligned)[4] = (uint32_t (*)[4])&words[1];

 	/* LOAD PAIR FROM QUADWORD (LPQ) requires quadword alignment */
 	asm volatile ("lpq %%r6,%[bad]"
 		      : : [bad] "T" (*bad_aligned)
 		      : "%r6", "%r7"
 	);
 	return 0;
 }

 static int not_even(void)
 {
 	uint64_t quad[2] __attribute__((aligned(16))) = {0};

 	asm volatile (".insn	rxy,0xe3000000008f,%%r7,%[quad]" /* lpq %%r7,%[quad] */
 		      : : [quad] "T" (quad)
 		      : "%r7", "%r8"
 	);
 	return 0;
 }

 /*
  * Harness for specification exception testing.
  * func only triggers exception, reporting is taken care of automatically.
  * If a trigger is transactable it will also be executed during a transaction.
  */
 struct spec_ex_trigger {
 	const char *name;
 	int (*func)(void);
 	bool transactable;
 	void (*fixup)(struct stack_frame_int *stack);
 };

 /* List of all tests to execute */
 static const struct spec_ex_trigger spec_ex_triggers[] = {
 	{ "psw_bit_12_is_1", &psw_bit_12_is_1, false, &fixup_invalid_psw },
 	{ "short_psw_bit_12_is_0", &short_psw_bit_12_is_0, false, &fixup_invalid_psw },
 	{ "bad_alignment", &bad_alignment, true, NULL },
 	{ "not_even", &not_even, true, NULL },
 	{ NULL, NULL, false, NULL },
 };

 static void test_spec_ex(const struct spec_ex_trigger *trigger)
 {
 	int rc;

 	expect_pgm_int();
 	register_pgm_cleanup_func(trigger->fixup);
 	rc = trigger->func();
 	register_pgm_cleanup_func(NULL);
 	/* test failed, nothing to be done, reporting responsibility of trigger */
 	if (rc)
 		return;
 	check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
 }

 #define TRANSACTION_COMPLETED 4
 #define TRANSACTION_MAX_RETRIES 5

 /*
  * NULL must not be passed to __builtin_tbegin via variable, only constant,
  * forbid diagnose from being NULL at all to keep things simple
  */
 static int __attribute__((nonnull))
 with_transaction(int (*trigger)(void), struct __htm_tdb *diagnose)
 {
 	int cc;

 	cc = __builtin_tbegin(diagnose);
 	/*
 	 * Everything between tbegin and tend is part of the transaction,
 	 * which either completes in its entirety or does not have any effect.
 	 * If the transaction fails, execution is reset to this point with another
 	 * condition code indicating why the transaction failed.
 	 */
 	if (cc == _HTM_TBEGIN_STARTED) {
 		/*
 		 * return code is meaningless: transaction needs to complete
 		 * in order to return and completion indicates a test failure
 		 */
 		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 = lowcore.pgm_int_code;
 			if (pgm == expected_pgm)
 				return 0;
 			else if (pgm == 0)
 				/*
 				 * Transaction failed for unknown reason but not because
 				 * of an unexpected program exception. Give it another
 				 * go so that hopefully it reaches the triggering instruction.
 				 */
 				continue;
 		}
 		return trans_result;
 	}
 	return TRANSACTION_MAX_RETRIES;
 }

 struct args {
 	uint64_t max_retries;
 	bool diagnose;
 };

 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;
 	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 */

 	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:
 		report_pass("Program interrupt: expected(%d) == received(%d)",
 			    expected_pgm, expected_pgm);
 		break;
 	case _HTM_TBEGIN_INDETERMINATE:
 	case _HTM_TBEGIN_PERSISTENT:
 		report_info("transaction failed with cc %d", trans_result);
 		report_info("transaction abort code: %llu", diag.tdb.abort_code);
 		if (args->diagnose)
 			for (i = 0; i < 32; i++)
 				report_info("diag+%03d: %016lx", i * 8, diag.dwords[i]);
 		break;
 	case _HTM_TBEGIN_TRANSIENT:
 		report_fail("Program interrupt: expected(%d) == received(%d)",
 			    expected_pgm, clear_pgm_int());
 		break;
 	case TRANSACTION_COMPLETED:
 		report_fail("Transaction completed without exception");
 		break;
 	case TRANSACTION_MAX_RETRIES:
 		report_skip("Transaction retried %lu times with transient failures, giving up",
 			    args->max_retries);
 		break;
 	default:
 		report_fail("Invalid transaction result");
 		break;
 	}

 	ctl_clear_bit(0, CTL0_TRANSACT_EX_CTL);
 }

 static bool parse_unsigned(const char *arg, unsigned int *out)
 {
 	char *end;
 	long num;

 	if (arg[0] == '\0')
 		return false;
 	num = strtol(arg, &end, 10);
 	if (end[0] != '\0' || num < 0)
 		return false;
 	*out = num;
 	return true;
 }

 static struct args parse_args(int argc, char **argv)
 {
 	struct args args = {
 		.max_retries = 20,
 		.diagnose = false
 	};
 	unsigned int i, arg;
 	bool has_arg;
 	const char *flag;

 	for (i = 1; i < argc; i++) {
 		if (i + 1 < argc)
 			has_arg = parse_unsigned(argv[i + 1], &arg);
 		else
 			has_arg = false;

 		flag = "--max-retries";
 		if (!strcmp(flag, argv[i])) {
 			if (!has_arg)
 				report_abort("%s needs a positive parameter", flag);
 			args.max_retries = arg;
 			++i;
 			continue;
 		}
 		if (!strcmp("--diagnose", argv[i])) {
 			args.diagnose = true;
 			continue;
 		}
 		if (!strcmp("--no-diagnose", argv[i])) {
 			args.diagnose = false;
 			continue;
 		}
 		report_abort("Unsupported parameter '%s'",
 			     argv[i]);
 	}

 	return args;
 }

 int main(int argc, char **argv)
 {
 	unsigned int i;

 	struct args args = parse_args(argc, argv);

 	report_prefix_push("specification exception");
 	for (i = 0; spec_ex_triggers[i].name; i++) {
 		report_prefix_push(spec_ex_triggers[i].name);
 		test_spec_ex(&spec_ex_triggers[i]);
 		report_prefix_pop();
 	}
 	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();
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright IBM Corp. 2021, 2022
	*
	* 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).
	*
	* Can be extended by adding triggers to spec_ex_triggers, see comments below.
	*/
	#include <stdlib.h>
	#include <htmintrin.h>
	#include <libcflat.h>
	#include <bitops.h>
	#include <asm/barrier.h>
	#include <asm/interrupt.h>
	#include <asm/facility.h>

	/* toggled to signal occurrence of invalid psw fixup */
	static bool invalid_psw_expected;
	static struct psw expected_psw;
	static struct psw invalid_psw;
	static struct psw fixup_psw;

	/*
	* The standard program exception handler cannot deal with invalid old PSWs,
	* especially not invalid instruction addresses, as in that case one cannot
	* find the instruction following the faulting one from the old PSW.
	* The PSW to return to is set by load_psw.
	*/
	static void fixup_invalid_psw(struct stack_frame_int *stack)
	{
	assert_msg(invalid_psw_expected,
	"Unexpected invalid PSW during program interrupt fixup: %#lx %#lx",
	lowcore.pgm_old_psw.mask, lowcore.pgm_old_psw.addr);
	/* signal occurrence of invalid psw fixup */
	invalid_psw_expected = false;
	invalid_psw = lowcore.pgm_old_psw;
	lowcore.pgm_old_psw = fixup_psw;
	}

	/*
	* Load possibly invalid psw, but setup fixup_psw before,
	* so that fixup_invalid_psw() can bring us back onto the right track.
	* Also acts as compiler barrier, -> none required in expect/check_invalid_psw
	*/
	static void load_psw(struct psw psw)
	{
	uint64_t scratch;

	/*
	* The fixup psw is the current psw with the instruction address replaced
	* by the address of the nop following the instruction loading the new psw.
	*/
	fixup_psw.mask = extract_psw_mask();
	asm volatile ( "larl %[scratch],0f\n"
	" stg %[scratch],%[fixup_addr]\n"
	" lpswe %[psw]\n"
	"0: nop\n"
	: [scratch] "=&d" (scratch),
	[fixup_addr] "=&T" (fixup_psw.addr)
	: [psw] "Q" (psw)
	: "cc", "memory"
	);
	}

	static void load_short_psw(struct short_psw psw)
	{
	uint64_t scratch;

	fixup_psw.mask = extract_psw_mask();
	asm volatile ( "larl %[scratch],0f\n"
	" stg %[scratch],%[fixup_addr]\n"
	" lpsw %[psw]\n"
	"0: nop\n"
	: [scratch] "=&d" (scratch),
	[fixup_addr] "=&T" (fixup_psw.addr)
	: [psw] "Q" (psw)
	: "cc", "memory"
	);
	}

	static void expect_invalid_psw(struct psw psw)
	{
	expected_psw = psw;
	invalid_psw_expected = true;
	}

	static int check_invalid_psw(void)
	{
	/* Since the fixup sets this to false we check for false here. */
	if (!invalid_psw_expected) {
	if (expected_psw.mask == invalid_psw.mask &&
	expected_psw.addr == invalid_psw.addr)
	return 0;
	report_fail("Wrong invalid PSW");
	} else {
	report_fail("Expected exception due to invalid PSW");
	}
	return 1;
	}

	/* For normal PSWs bit 12 has to be 0 to be a valid PSW*/
	static int psw_bit_12_is_1(void)
	{
	struct psw invalid = {
	.mask = BIT(63 - 12),
	.addr = 0x00000000deadbeee
	};

	expect_invalid_psw(invalid);
	load_psw(invalid);
	return check_invalid_psw();
	}

	/* A short PSW needs to have bit 12 set to be valid. */
	static int short_psw_bit_12_is_0(void)
	{
	struct psw invalid = {
	.mask = BIT(63 - 12),
	.addr = 0x00000000deadbeee
	};
	struct short_psw short_invalid = {
	.mask = 0x0,
	.addr = 0xdeadbeee
	};

	expect_invalid_psw(invalid);
	load_short_psw(short_invalid);
	/*
	* lpsw may optionally check bit 12 before loading the new psw
	* -> cannot check the expected invalid psw like with lpswe
	*/
	return 0;
	}

	static int bad_alignment(void)
	{
	uint32_t words[5] __attribute__((aligned(16)));
	uint32_t (bad_aligned)[4] = (uint32_t ()[4])&words[1];

	/* LOAD PAIR FROM QUADWORD (LPQ) requires quadword alignment */
	asm volatile ("lpq %%r6,%[bad]"
	: : [bad] "T" (*bad_aligned)
	: "%r6", "%r7"
	);
	return 0;
	}

	static int not_even(void)
	{
	uint64_t quad[2] __attribute__((aligned(16))) = {0};

	asm volatile (".insn rxy,0xe3000000008f,%%r7,%[quad]" /* lpq %%r7,%[quad] */
	: : [quad] "T" (quad)
	: "%r7", "%r8"
	);
	return 0;
	}

	/*
	* Harness for specification exception testing.
	* func only triggers exception, reporting is taken care of automatically.
	* If a trigger is transactable it will also be executed during a transaction.
	*/
	struct spec_ex_trigger {
	const char *name;
	int (*func)(void);
	bool transactable;
	void (fixup)(struct stack_frame_int stack);
	};

	/* List of all tests to execute */
	static const struct spec_ex_trigger spec_ex_triggers[] = {
	{ "psw_bit_12_is_1", &psw_bit_12_is_1, false, &fixup_invalid_psw },
	{ "short_psw_bit_12_is_0", &short_psw_bit_12_is_0, false, &fixup_invalid_psw },
	{ "bad_alignment", &bad_alignment, true, NULL },
	{ "not_even", &not_even, true, NULL },
	{ NULL, NULL, false, NULL },
	};

	static void test_spec_ex(const struct spec_ex_trigger *trigger)
	{
	int rc;

	expect_pgm_int();
	register_pgm_cleanup_func(trigger->fixup);
	rc = trigger->func();
	register_pgm_cleanup_func(NULL);
	/* test failed, nothing to be done, reporting responsibility of trigger */
	if (rc)
	return;
	check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
	}

	#define TRANSACTION_COMPLETED 4
	#define TRANSACTION_MAX_RETRIES 5

	/*
	* NULL must not be passed to __builtin_tbegin via variable, only constant,
	* forbid diagnose from being NULL at all to keep things simple
	*/
	static int __attribute__((nonnull))
	with_transaction(int (trigger)(void), struct __htm_tdb diagnose)
	{
	int cc;

	cc = __builtin_tbegin(diagnose);
	/*
	* Everything between tbegin and tend is part of the transaction,
	* which either completes in its entirety or does not have any effect.
	* If the transaction fails, execution is reset to this point with another
	* condition code indicating why the transaction failed.
	*/
	if (cc == _HTM_TBEGIN_STARTED) {
	/*
	* return code is meaningless: transaction needs to complete
	* in order to return and completion indicates a test failure
	*/
	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 = lowcore.pgm_int_code;
	if (pgm == expected_pgm)
	return 0;
	else if (pgm == 0)
	/*
	* Transaction failed for unknown reason but not because
	* of an unexpected program exception. Give it another
	* go so that hopefully it reaches the triggering instruction.
	*/
	continue;
	}
	return trans_result;
	}
	return TRANSACTION_MAX_RETRIES;
	}

	struct args {
	uint64_t max_retries;
	bool diagnose;
	};

	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;
	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 */

	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:
	report_pass("Program interrupt: expected(%d) == received(%d)",
	expected_pgm, expected_pgm);
	break;
	case _HTM_TBEGIN_INDETERMINATE:
	case _HTM_TBEGIN_PERSISTENT:
	report_info("transaction failed with cc %d", trans_result);
	report_info("transaction abort code: %llu", diag.tdb.abort_code);
	if (args->diagnose)
	for (i = 0; i < 32; i++)
	report_info("diag+%03d: %016lx", i * 8, diag.dwords[i]);
	break;
	case _HTM_TBEGIN_TRANSIENT:
	report_fail("Program interrupt: expected(%d) == received(%d)",
	expected_pgm, clear_pgm_int());
	break;
	case TRANSACTION_COMPLETED:
	report_fail("Transaction completed without exception");
	break;
	case TRANSACTION_MAX_RETRIES:
	report_skip("Transaction retried %lu times with transient failures, giving up",
	args->max_retries);
	break;
	default:
	report_fail("Invalid transaction result");
	break;
	}

	ctl_clear_bit(0, CTL0_TRANSACT_EX_CTL);
	}

	static bool parse_unsigned(const char arg, unsigned int out)
	{
	char *end;
	long num;

	if (arg[0] == '\0')
	return false;
	num = strtol(arg, &end, 10);
	if (end[0] != '\0' \|\| num < 0)
	return false;
	*out = num;
	return true;
	}

	static struct args parse_args(int argc, char **argv)
	{
	struct args args = {
	.max_retries = 20,
	.diagnose = false
	};
	unsigned int i, arg;
	bool has_arg;
	const char *flag;

	for (i = 1; i < argc; i++) {
	if (i + 1 < argc)
	has_arg = parse_unsigned(argv[i + 1], &arg);
	else
	has_arg = false;

	flag = "--max-retries";
	if (!strcmp(flag, argv[i])) {
	if (!has_arg)
	report_abort("%s needs a positive parameter", flag);
	args.max_retries = arg;
	++i;
	continue;
	}
	if (!strcmp("--diagnose", argv[i])) {
	args.diagnose = true;
	continue;
	}
	if (!strcmp("--no-diagnose", argv[i])) {
	args.diagnose = false;
	continue;
	}
	report_abort("Unsupported parameter '%s'",
	argv[i]);
	}

	return args;
	}

	int main(int argc, char **argv)
	{
	unsigned int i;

	struct args args = parse_args(argc, argv);

	report_prefix_push("specification exception");
	for (i = 0; spec_ex_triggers[i].name; i++) {
	report_prefix_push(spec_ex_triggers[i].name);
	test_spec_ex(&spec_ex_triggers[i]);
	report_prefix_pop();
	}
	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();
	}