Re: [PATCH v8 4/4] selftests: KVM: testing the local IRQs resets

[Janosch Frank <frankja@linux.ibm.com>]

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On 1/30/20 12:10 PM, Thomas Huth wrote:
> On 29/01/2020 21.03, Janosch Frank wrote:
>> From: Pierre Morel <pmorel@linux.ibm.com>
>>
>> Local IRQs are reset by a normal cpu reset.  The initial cpu reset and
>> the clear cpu reset, as superset of the normal reset, both clear the
>> IRQs too.
>>
>> Let's inject an interrupt to a vCPU before calling a reset and see if
>> it is gone after the reset.
>>
>> We choose to inject only an emergency interrupt at this point and can
>> extend the test to other types of IRQs later.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>  tools/testing/selftests/kvm/s390x/resets.c | 57 ++++++++++++++++++++++
>>  1 file changed, 57 insertions(+)
>>
>> diff --git a/tools/testing/selftests/kvm/s390x/resets.c b/tools/testing/selftests/kvm/s390x/resets.c
>> index 2b2378cc9e80..299c1686f98c 100644
>> --- a/tools/testing/selftests/kvm/s390x/resets.c
>> +++ b/tools/testing/selftests/kvm/s390x/resets.c
>> @@ -14,6 +14,9 @@
>>  #include "kvm_util.h"
>>  
>>  #define VCPU_ID 3
>> +#define LOCAL_IRQS 32
>> +
>> +struct kvm_s390_irq buf[VCPU_ID + LOCAL_IRQS];
>>  
>>  struct kvm_vm *vm;
>>  struct kvm_run *run;
>> @@ -52,6 +55,29 @@ static void test_one_reg(uint64_t id, uint64_t value)
>>  	TEST_ASSERT(eval_reg == value, "value == %s", value);
>>  }
>>  
>> +static void assert_noirq(void)
>> +{
>> +	struct kvm_s390_irq_state irq_state;
>> +	int irqs;
>> +
>> +	if (!(kvm_check_cap(KVM_CAP_S390_INJECT_IRQ) &&
>> +	    kvm_check_cap(KVM_CAP_S390_IRQ_STATE)))
>> +		return;
>> +
>> +	irq_state.len = sizeof(buf);
>> +	irq_state.buf = (unsigned long)buf;
>> +	irqs = _vcpu_ioctl(vm, VCPU_ID, KVM_S390_GET_IRQ_STATE, &irq_state);
>> +	/*
>> +	 * irqs contains the number of retrieved interrupts, apart from the
>> +	 * emergency call that should be cleared by the resets, there should be
>> +	 * none.
>> +	 */
>> +	if (irqs < 0)
>> +		printf("Error by getting IRQ: errno %d\n", errno);
>> +
>> +	TEST_ASSERT(!irqs, "IRQ pending");
>> +}
>> +
>>  static void assert_clear(void)
>>  {
>>  	struct kvm_sregs sregs;
>> @@ -93,6 +119,31 @@ static void assert_initial(void)
>>  static void assert_normal(void)
>>  {
>>  	test_one_reg(KVM_REG_S390_PFTOKEN, KVM_S390_PFAULT_TOKEN_INVALID);
>> +	assert_noirq();
>> +}
>> +
>> +static int inject_irq(int cpu_id)
>> +{
>> +	struct kvm_s390_irq_state irq_state;
>> +	struct kvm_s390_irq *irq = &buf[0];
>> +	int irqs;
>> +
>> +	if (!(kvm_check_cap(KVM_CAP_S390_INJECT_IRQ) &&
>> +	    kvm_check_cap(KVM_CAP_S390_IRQ_STATE)))
>> +		return 0;
>> +
>> +	/* Inject IRQ */
>> +	irq_state.len = sizeof(struct kvm_s390_irq);
>> +	irq_state.buf = (unsigned long)buf;
>> +	irq->type = KVM_S390_INT_EMERGENCY;
>> +	irq->u.emerg.code = cpu_id;
>> +	irqs = _vcpu_ioctl(vm, cpu_id, KVM_S390_SET_IRQ_STATE, &irq_state);
>> +	if (irqs < 0) {
>> +		printf("Error by injecting INT_EMERGENCY: errno %d\n", errno);
>> +		return errno;
>> +	}
> 
> Can you turn this into a TEST_ASSERT() instead? Otherwise the printf()
> error might go unnoticed.

I've converted both error checks into asserts (set/get irq) and made the
function void.


> 
> Apart from that (and the nits that Cornelia already mentioned), the
> patch looks fine to me.
> 
>  Thomas
> 



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