Re: [PATCH v9 6/6] selftests: KVM: testing the local IRQs resets

Cornelia Huck
2020-01-30T16:28:14Z

On Thu, 30 Jan 2020 07:34:34 -0500
Janosch Frank <frankja@linux.ibm.com> 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>
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>[minor fixups]
> ---
> tools/testing/selftests/kvm/s390x/resets.c | 46 ++++++++++++++++++++++
> 1 file changed, 46 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/s390x/resets.c b/tools/testing/selftests/kvm/s390x/resets.c
> index 4e173517f909..8a2507930e7d 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

The choice of 32 here is still a bit unclear (although not a problem).

> +
> +struct kvm_s390_irq buf[VCPU_ID + LOCAL_IRQS];
>
> struct kvm_vm *vm;
> struct kvm_run *run;
> @@ -53,6 +56,27 @@ 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;

I think you should drop the capability check here as well.

> +
> + 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.

What about the updated comment? :)

> + */
> + TEST_ASSERT(irqs >= 0, "Could not fetch IRQs: errno %d\n", errno);
> + TEST_ASSERT(!irqs, "IRQ pending");
> +}
> +
> static void assert_clear(void)
> {
> struct kvm_sregs sregs;

Else, looks sane to me.