Re: [kvm-unit-tests PATCH 3/4] s390x: smp: Test all CRs on initial reset

[Thomas Huth <thuth@redhat.com>]

On 14/01/2020 16.30, Janosch Frank wrote:
> All CRs are set to 0 and CRs 0 and 14 are set to pre-defined values,
> so we also need to test 1-13 and 15 for 0.
> 
> And while we're at it, let's also set some values to cr 1, 7 and 13, so
> we can actually be sure that they will be zeroed.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  s390x/smp.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/s390x/smp.c b/s390x/smp.c
> index 767d167..11ab425 100644
> --- a/s390x/smp.c
> +++ b/s390x/smp.c
> @@ -175,16 +175,31 @@ static void test_emcall(void)
>  	report_prefix_pop();
>  }
>  
> +static void test_func_initial(void)
> +{
> +	lctlg(1, 0x42000UL);
> +	lctlg(7, 0x43000UL);
> +	lctlg(13, 0x44000UL);
> +	testflag = 1;
> +	mb();
> +	cpu_loop();
> +}
> +
>  static void test_reset_initial(void)
>  {
>  	struct cpu_status *status = alloc_pages(0);
> +	uint8_t *nullp = alloc_pages(0);

Why not simply:

        uint64_t nullp[12];

?

>  	struct psw psw;
>  
> +	memset(nullp, 0, PAGE_SIZE);
>  	psw.mask = extract_psw_mask();
> -	psw.addr = (unsigned long)test_func;
> +	psw.addr = (unsigned long)test_func_initial;
>  
>  	report_prefix_push("reset initial");
> +	testflag = 0;
> +	mb();
>  	smp_cpu_start(1, psw);
> +	wait_for_flag();
>  
>  	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
>  	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
> @@ -195,6 +210,8 @@ static void test_reset_initial(void)
>  	report(!status->fpc, "fpc");
>  	report(!status->cputm, "cpu timer");
>  	report(!status->todpr, "todpr");
> +	report(!memcmp(&status->crs[1], nullp, sizeof(status->crs[1]) * 12), "cr1-13 == 0");
> +	report(status->crs[15] == 0, "cr15 == 0");
>  	report_prefix_pop();
>  
>  	report_prefix_push("initialized");
> @@ -204,6 +221,7 @@ static void test_reset_initial(void)
>  
>  	report(smp_cpu_stopped(1), "cpu stopped");
>  	free_pages(status, PAGE_SIZE);
> +	free_pages(nullp, PAGE_SIZE);
>  	report_prefix_pop();
>  }
>  
> @@ -219,6 +237,7 @@ static void test_reset(void)
>  
>  	sigp_retry(1, SIGP_CPU_RESET, 0, NULL);
>  	report(smp_cpu_stopped(1), "cpu stopped");
> +	smp_cpu_destroy(1);

Shouldn't that rather be part of patch 2/4 ? I'd maybe also move this to
the main() function instead since you've setup the cpu there...? Also is
it still ok to use smp_cpu_start() in test_reset_initial() after you've
destroyed the CPU here in test_reset()?

>  	report_prefix_pop();
>  }

 Thomas