Re: [kvm-unit-tests PATCH v2 6/7] s390x: smp: Test all CRs on initial reset

Janosch Frank
2020-01-16T13:07:21Z

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On 1/16/20 1:24 PM, David Hildenbrand wrote:
> On 16.01.20 13:05, 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 | 19 ++++++++++++++++++-
>> 1 file changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/s390x/smp.c b/s390x/smp.c
>> index d430638..ce3215d 100644
>> --- a/s390x/smp.c
>> +++ b/s390x/smp.c
>> @@ -176,16 +176,31 @@ 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);
>> + testflag = 1;
>> + mb();
>> + cpu_loop();
>
> Can we make cpu_loop() the default when this function returns? (IOW, an
> endless loop whenever a cpu finished executing the function?)

So adding it to cstart64.S after the br 14?

>
> Do we need the mb() here?

Would the compiler reorder the lctlcg and testflag if it could?

>
>> +}
>> +
>> 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");
>> + 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);
>> @@ -196,6 +211,8 @@ 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");
>>
>
>

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