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

Thomas Huth
2020-01-30T11:10:40Z

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.

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

Thomas