[kvm-unit-tests PATCH v7 0/2] Add specification exception tests

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

Test that specification exceptions cause the correct interruption code
during both normal and transactional execution.

TCG fails the tests setting an invalid PSW bit.
I had a look at how best to fix it, but where best to check for early
PSW exceptions was not immediately clear to me. Ideas welcome.

v6 -> v7
	assert that we're expecting the invalid PSW we're seeing
	rebased onto master
	picked up tags (thanks Nico & Janosch)
	comments and style changes

v5 -> v6
	rebased onto master
	comments and style changes

v4 -> v5
	add lpsw with invalid bit 12 test
		TCG fails as with lpswe but must also invert bit 12
	update copyright statement
	add comments
	cleanups and style fixes

v3 -> v4
	remove iterations argument in order to simplify the code
		for manual performance testing adding a for loop is easy
	move report out of fixup_invalid_psw
	simplify/improve readability of triggers
	use positive error values

v2 -> v3
	remove non-ascii symbol
	clean up load_psw
	fix nits

v1 -> v2
	Add license and test description
	Split test patch into normal test and transactional execution test
	Add comments to
		invalid PSW fixup function
		with_transaction
	Rename some variables/functions
	Pass mask as single parameter to asm
	Get rid of report_info_if macro
	Introduce report_pass/fail and use them

Janis Schoetterl-Glausch (2):
  s390x: Add specification exception test
  s390x: Test specification exceptions during transaction

 s390x/Makefile           |   1 +
 lib/s390x/asm/arch_def.h |   6 +
 s390x/spec_ex.c          | 392 +++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg      |   3 +
 4 files changed, 402 insertions(+)
 create mode 100644 s390x/spec_ex.c

Range-diff against v6:
1:  bbfb5d40 ! 1:  a239437a s390x: Add specification exception test
    @@ Commit message
         Generate specification exceptions and check that they occur.
     
         Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
    +    Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
    +    Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
     
      ## s390x/Makefile ##
     @@ s390x/Makefile: tests += $(TEST_DIR)/uv-host.elf
    @@ s390x/spec_ex.c (new)
     + */
     +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;
    @@ s390x/spec_ex.c (new)
     +	uint64_t scratch;
     +
     +	/*
    -+	 * The fixup psw is current psw with the instruction address replaced by
    -+	 * the address of the nop following the instruction loading the new psw.
    ++	 * 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"
    @@ s390x/spec_ex.c (new)
     +
     +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)
    @@ s390x/spec_ex.c (new)
     +/* 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
     +	 */
    -+	load_short_psw(short_invalid);
     +	return 0;
     +}
     +
2:  0f19be7d ! 2:  697409f7 s390x: Test specification exceptions during transaction
    @@ Commit message
         Check that we see the expected code for (some) specification exceptions.
     
         Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
    +    Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
    +    Acked-by: Janosch Frank <frankja@linux.ibm.com>
     
      ## lib/s390x/asm/arch_def.h ##
     @@ lib/s390x/asm/arch_def.h: struct cpu {
    @@ s390x/spec_ex.c: static int not_even(void)
      /*
       * 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.
    ++ * If a trigger is transactable it will also be executed during a transaction.
       */
      struct spec_ex_trigger {
      	const char *name;
    @@ s390x/spec_ex.c: static void test_spec_ex(const struct spec_ex_trigger *trigger)
     +#define TRANSACTION_MAX_RETRIES 5
     +
     +/*
    -+ * NULL must be passed to __builtin_tbegin via constant, forbid diagnose from
    -+ * being NULL to keep things simple
    ++ * 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)
    @@ s390x/spec_ex.c: static void test_spec_ex(const struct spec_ex_trigger *trigger)
     +
     +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;
    ++	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)];

base-commit: d8a4f9e5e8d69d4ef257b40d6cd666bd2f63494e
-- 
2.36.1