Re: [kvm-unit-tests PATCH v4 2/9] s390x: smp: Only use smp_cpu_setup once

From: Janosch Frank <frankja@linux.ibm.com>
To: David Hildenbrand <david@redhat.com>, kvm@vger.kernel.org
Cc: thuth@redhat.com, borntraeger@de.ibm.com,
	linux-s390@vger.kernel.org, cohuck@redhat.com
Subject: Re: [kvm-unit-tests PATCH v4 2/9] s390x: smp: Only use smp_cpu_setup once
Date: Thu, 23 Jan 2020 14:54:46 +0100	[thread overview]
Message-ID: <e09c42a7-279a-7e8b-8241-26c69940cdd0@linux.ibm.com> (raw)
In-Reply-To: <ef7894ff-4179-6730-ce28-c48e7730eff8@redhat.com>


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On 1/23/20 2:45 PM, David Hildenbrand wrote:
> On 21.01.20 14:42, Janosch Frank wrote:
>> Let's stop and start instead of using setup to run a function on a
>> cpu.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> Acked-by: David Hildenbrand <david@redhat.com>
>> ---
>>  s390x/smp.c | 21 ++++++++++++++-------
>>  1 file changed, 14 insertions(+), 7 deletions(-)
>>
>> diff --git a/s390x/smp.c b/s390x/smp.c
>> index e37eb56..3e8cf3e 100644
>> --- a/s390x/smp.c
>> +++ b/s390x/smp.c
>> @@ -53,7 +53,7 @@ static void test_start(void)
>>  	psw.addr = (unsigned long)test_func;
>>  
>>  	set_flag(0);
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  	wait_for_flag();
>>  	report(1, "start");
>>  }
>> @@ -109,6 +109,7 @@ static void test_store_status(void)
>>  	report(1, "status written");
>>  	free_pages(status, PAGE_SIZE * 2);
>>  	report_prefix_pop();
>> +	smp_cpu_stop(1);
>>  
>>  	report_prefix_pop();
>>  }
>> @@ -137,9 +138,8 @@ static void test_ecall(void)
>>  
>>  	report_prefix_push("ecall");
>>  	set_flag(0);
>> -	smp_cpu_destroy(1);
>>  
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  	wait_for_flag();
>>  	set_flag(0);
>>  	sigp(1, SIGP_EXTERNAL_CALL, 0, NULL);
>> @@ -172,9 +172,8 @@ static void test_emcall(void)
>>  
>>  	report_prefix_push("emcall");
>>  	set_flag(0);
>> -	smp_cpu_destroy(1);
>>  
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  	wait_for_flag();
>>  	set_flag(0);
>>  	sigp(1, SIGP_EMERGENCY_SIGNAL, 0, NULL);
>> @@ -192,7 +191,7 @@ static void test_reset_initial(void)
>>  	psw.addr = (unsigned long)test_func;
>>  
>>  	report_prefix_push("reset initial");
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  
>>  	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
>>  	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
>> @@ -223,7 +222,7 @@ static void test_reset(void)
>>  	psw.addr = (unsigned long)test_func;
>>  
>>  	report_prefix_push("cpu reset");
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  
>>  	sigp_retry(1, SIGP_CPU_RESET, 0, NULL);
>>  	report(smp_cpu_stopped(1), "cpu stopped");
>> @@ -232,6 +231,7 @@ static void test_reset(void)
>>  
>>  int main(void)
>>  {
>> +	struct psw psw;
>>  	report_prefix_push("smp");
>>  
>>  	if (smp_query_num_cpus() == 1) {
>> @@ -239,6 +239,12 @@ int main(void)
>>  		goto done;
>>  	}
>>  
>> +	/* Setting up the cpu to give it a stack and lowcore */
>> +	psw.mask = extract_psw_mask();
>> +	psw.addr = (unsigned long)cpu_loop;
>> +	smp_cpu_setup(1, psw);
>> +	smp_cpu_stop(1);
>> +
>>  	test_start();
>>  	test_stop();
>>  	test_stop_store_status();
>> @@ -247,6 +253,7 @@ int main(void)
>>  	test_emcall();
>>  	test_reset();
>>  	test_reset_initial();
>> +	smp_cpu_destroy(1);
>>  
>>  done:
>>  	report_prefix_pop();
>>
> 
> With this patch, I get timeouts under TCG. Seems to loop forever.
> 
The branch works on lpar and kvm without a problem.


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