On 3/24/20 10:52 AM, Christian Borntraeger wrote:
> 
> 
> On 24.03.20 09:12, 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>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>>  s390x/smp.c | 16 +++++++++++++++-
>>  1 file changed, 15 insertions(+), 1 deletion(-)
>>
>> diff --git a/s390x/smp.c b/s390x/smp.c
>> index fa40753524f321d4..8c9b98aabd9e8222 100644
>> --- a/s390x/smp.c
>> +++ b/s390x/smp.c
>> @@ -182,16 +182,28 @@ static void test_emcall(void)
>>  	report_prefix_pop();
>>  }
>>
>> +/* Used to dirty registers of cpu #1 before it is reset */
>> +static void test_func_initial(void)
>> +{
>> +	lctlg(1, 0x42000UL);
>> +	lctlg(7, 0x43000UL);
>> +	lctlg(13, 0x44000UL);
>> +	set_flag(1);
>> +}
>> +
>>  static void test_reset_initial(void)
>>  {
>>  	struct cpu_status *status = alloc_pages(0);
>> +	uint64_t nullp[12] = {};
>>  	struct psw psw;
>>
>>  	psw.mask = extract_psw_mask();
>> -	psw.addr = (unsigned long)test_func;
>> +	psw.addr = (unsigned long)test_func_initial;
>>
>>  	report_prefix_push("reset initial");
>> +	set_flag(0);
>>  	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);
>> @@ -202,6 +214,8 @@ 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();
> 
> Why not add a check for crs[0] == 0xe0 
> and crs[14] = 0xc2000000

You mean the checks which are done a few lines below this?
This patch just actually dirties registers which should be set to 0 so
we can really be sure that they have been touched.