Re: [kvm-unit-tests PATCH 1/1] s390x: css: check the CSS is working with any ISC

[Cornelia Huck <cohuck@redhat.com>]

On Thu, Aug 12 2021, Pierre Morel <pmorel@linux.ibm.com> wrote:

> In the previous version we did only check that one ISC dedicated by
> Linux for I/O is working fine.
>
> However, there is no reason to prefer one ISC to another ISC, we are
> free to take anyone.
>
> Let's check all possible ISC to verify that QEMU/KVM is really ISC
> independent.

It's probably a good idea to test for a non-standard isc. Not sure
whether we need all of them, but it doesn't hurt.

Do you also have plans for a test to verify the priority handling for
the different iscs?

>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  s390x/css.c | 25 +++++++++++++++++--------
>  1 file changed, 17 insertions(+), 8 deletions(-)
>

(...)

> @@ -142,7 +143,6 @@ static void sense_id(void)
>  
>  static void css_init(void)
>  {
> -	assert(register_io_int_func(css_irq_io) == 0);
>  	lowcore_ptr->io_int_param = 0;
>  
>  	report(get_chsc_scsc(), "Store Channel Characteristics");
> @@ -351,11 +351,20 @@ int main(int argc, char *argv[])
>  	int i;
>  
>  	report_prefix_push("Channel Subsystem");
> -	enable_io_isc(0x80 >> IO_SCH_ISC);
> -	for (i = 0; tests[i].name; i++) {
> -		report_prefix_push(tests[i].name);
> -		tests[i].func();
> -		report_prefix_pop();
> +
> +	for (io_isc = 0; io_isc < 8; io_isc++) {
> +		report_info("ISC: %d\n", io_isc);
> +
> +		enable_io_isc(0x80 >> io_isc);
> +		assert(register_io_int_func(css_irq_io) == 0);

Why are you registering/deregistering the irq handler multiple times? It
should be the same, regardless of the isc?

> +
> +		for (i = 0; tests[i].name; i++) {
> +			report_prefix_push(tests[i].name);
> +			tests[i].func();
> +			report_prefix_pop();
> +		}
> +
> +		unregister_io_int_func(css_irq_io);
>  	}
>  	report_prefix_pop();
>  
>