Re: [kvm-unit-tests PATCH v5 5/6] s390x: css: testing measurement block format 0

[Cornelia Huck <cohuck@redhat.com>]

On Tue,  9 Mar 2021 13:51:16 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:

> We test the update of the measurement block format 0, the
> measurement block origin is calculated from the mbo argument
> used by the SCHM instruction and the offset calculated using
> the measurement block index of the SCHIB.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  lib/s390x/css.h     | 12 ++++++
>  lib/s390x/css_lib.c |  4 --
>  s390x/css.c         | 95 ++++++++++++++++++++++++++++++++++++++++-----
>  3 files changed, 98 insertions(+), 13 deletions(-)
> 

(...)

> diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c
> index 95d9a78..8f09383 100644
> --- a/lib/s390x/css_lib.c
> +++ b/lib/s390x/css_lib.c
> @@ -365,10 +365,6 @@ void css_irq_io(void)
>  		       lowcore_ptr->io_int_param, sid);
>  		goto pop;
>  	}
> -	report_info("subsys_id_word: %08x io_int_param %08x io_int_word %08x",
> -			lowcore_ptr->subsys_id_word,
> -			lowcore_ptr->io_int_param,
> -			lowcore_ptr->io_int_word);

Hm, why are you removing it? If you are doing some general cleanup, it
probably belongs into patch 2?

>  	report_prefix_pop();
>  
>  	report_prefix_push("tsch");
> diff --git a/s390x/css.c b/s390x/css.c
> index a763814..b63826e 100644
> --- a/s390x/css.c
> +++ b/s390x/css.c
> @@ -74,18 +74,12 @@ static void test_sense(void)
>  		return;
>  	}
>  
> -	ret = register_io_int_func(css_irq_io);
> -	if (ret) {
> -		report(0, "Could not register IRQ handler");
> -		return;
> -	}
> -

This (and the cleanup changes) definitely belongs into patch 2.

>  	lowcore_ptr->io_int_param = 0;
>  
>  	senseid = alloc_io_mem(sizeof(*senseid), 0);
>  	if (!senseid) {
>  		report(0, "Allocation of senseid");
> -		goto error_senseid;
> +		return;
>  	}
>  
>  	ccw = ccw_alloc(CCW_CMD_SENSE_ID, senseid, sizeof(*senseid), CCW_F_SLI);
> @@ -137,8 +131,24 @@ error:
>  	free_io_mem(ccw, sizeof(*ccw));
>  error_ccw:
>  	free_io_mem(senseid, sizeof(*senseid));
> -error_senseid:
> -	unregister_io_int_func(css_irq_io);
> +}
> +
> +static void sense_id(void)
> +{
> +	struct ccw1 *ccw;
> +
> +	senseid = alloc_io_mem(sizeof(*senseid), 0);
> +	assert(senseid);
> +
> +	ccw = ccw_alloc(CCW_CMD_SENSE_ID, senseid, sizeof(*senseid), CCW_F_SLI);
> +	assert(ccw);

You're allocating senseid and ccw every time... wouldn't it be better
to allocate them once and pass them in as a parameter? (Not that it
should matter much, I guess.)

> +
> +	assert(!start_ccw1_chain(test_device_sid, ccw));
> +
> +	assert(wait_and_check_io_completion(test_device_sid) >= 0);
> +
> +	free_io_mem(ccw, sizeof(*ccw));
> +	free_io_mem(senseid, sizeof(*senseid));
>  }
>  
>  static void css_init(void)
> @@ -183,6 +193,72 @@ static void test_schm(void)
>  	report_prefix_pop();
>  }
>  
> +#define SCHM_UPDATE_CNT 10
> +static bool start_measuring(uint64_t mbo, uint16_t mbi, bool fmt1)
> +{
> +	int i;
> +
> +	if (!css_enable_mb(test_device_sid, mbo, mbi, PMCW_MBUE, fmt1)) {
> +		report_abort("Enabling measurement block failed");
> +		return false;
> +	}
> +
> +	for (i = 0; i < SCHM_UPDATE_CNT; i++)
> +		sense_id();
> +
> +	return true;
> +}
> +
> +/*
> + * test_schm_fmt0:
> + * With measurement block format 0 a memory space is shared
> + * by all subchannels, each subchannel can provide an index
> + * for the measurement block facility to store the measurements.
> + */
> +static void test_schm_fmt0(void)
> +{
> +	struct measurement_block_format0 *mb0;
> +	int shared_mb_size = 2 * sizeof(struct measurement_block_format0);
> +
> +	if (!test_device_sid) {
> +		report_skip("No device");
> +		return;
> +	}
> +
> +	/* Allocate zeroed Measurement block */
> +	mb0 = alloc_io_mem(shared_mb_size, 0);
> +	if (!mb0) {
> +		report_abort("measurement_block_format0 allocation failed");
> +		return;
> +	}
> +
> +	schm(NULL, 0); /* Stop any previous measurement */
> +	schm(mb0, SCHM_MBU);
> +
> +	/* Expect success */
> +	report_prefix_push("Valid MB address and index 0");
> +	report(start_measuring(0, 0, false) &&
> +	       mb0->ssch_rsch_count == SCHM_UPDATE_CNT,
> +	       "SSCH measured %d", mb0->ssch_rsch_count);
> +	report_prefix_pop();
> +
> +	/* Clear the measurement block for the next test */
> +	memset(mb0, 0, shared_mb_size);
> +
> +	/* Expect success */
> +	report_prefix_push("Valid MB address and index 1");
> +	if (start_measuring(0, 1, false))
> +		report(mb0[1].ssch_rsch_count == SCHM_UPDATE_CNT,
> +		       "SSCH measured %d", mb0[1].ssch_rsch_count);
> +	report_prefix_pop();
> +
> +	/* Stop the measurement */
> +	css_disable_mb(test_device_sid);
> +	schm(NULL, 0);
> +
> +	free_io_mem(mb0, shared_mb_size);
> +}
> +
>  static struct {
>  	const char *name;
>  	void (*func)(void);
> @@ -193,6 +269,7 @@ static struct {
>  	{ "enable (msch)", test_enable },
>  	{ "sense (ssch/tsch)", test_sense },
>  	{ "measurement block (schm)", test_schm },
> +	{ "measurement block format0", test_schm_fmt0 },
>  	{ NULL, NULL }
>  };
>