Re: [PATCH v4 4/6] KVM: selftests: Add test cases for unsupported PMU event filter input values

[Isaku Yamahata <isaku.yamahata@gmail.com>]

On Mon, Jul 17, 2023 at 02:23:41PM +0800,
Jinrong Liang <ljr.kernel@gmail.com> wrote:

> From: Jinrong Liang <cloudliang@tencent.com>
> 
> Add test cases to verify the handling of unsupported input values for the
> PMU event filter. The tests cover unsupported "action" values, unsupported
> "flags" values, and unsupported "nevents" values. All these cases should
> return an error, as they are currently not supported by the filter.
> Furthermore, the tests also cover the scenario where setting non-existent
> fixed counters in the fixed bitmap does not fail.
> 
> Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
> ---
>  .../kvm/x86_64/pmu_event_filter_test.c        | 26 +++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
> index ffcbbf25b29b..63f85f583ef8 100644
> --- a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
> @@ -32,6 +32,10 @@
>  #define MAX_FILTER_EVENTS		300
>  #define MAX_TEST_EVENTS		10
>  
> +#define PMU_EVENT_FILTER_INVALID_ACTION		(KVM_PMU_EVENT_DENY + 1)
> +#define PMU_EVENT_FILTER_INVALID_FLAGS			(KVM_PMU_EVENT_FLAG_MASKED_EVENTS + 1)

flag is a bit mask. Not number. So +1 sounds weird.
As KVM_PMU_EVENT_FLAGS_VALID_MASK = 1,  this happens to get wanted result, though.


> +#define PMU_EVENT_FILTER_INVALID_NEVENTS		(MAX_FILTER_EVENTS + 1)
> +
>  /*
>   * This is how the event selector and unit mask are stored in an AMD
>   * core performance event-select register. Intel's format is similar,
> @@ -757,6 +761,8 @@ static int set_pmu_single_event_filter(struct kvm_vcpu *vcpu, uint64_t event,
>  
>  static void test_filter_ioctl(struct kvm_vcpu *vcpu)
>  {
> +	uint8_t nr_fixed_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS);
> +	struct __kvm_pmu_event_filter f;
>  	uint64_t e = ~0ul;
>  	int r;
>  
> @@ -777,6 +783,26 @@ static void test_filter_ioctl(struct kvm_vcpu *vcpu)
>  					KVM_PMU_EVENT_FLAG_MASKED_EVENTS,
>  					KVM_PMU_EVENT_ALLOW);
>  	TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing");
> +
> +	f = base_event_filter;
> +	f.action = PMU_EVENT_FILTER_INVALID_ACTION;
> +	r = do_vcpu_set_pmu_event_filter(vcpu, &f);
> +	TEST_ASSERT(r, "Set invalid action is expected to fail");
> +
> +	f = base_event_filter;
> +	f.flags = PMU_EVENT_FILTER_INVALID_FLAGS;
> +	r = do_vcpu_set_pmu_event_filter(vcpu, &f);
> +	TEST_ASSERT(r, "Set invalid flags is expected to fail");
> +
> +	f = base_event_filter;
> +	f.nevents = PMU_EVENT_FILTER_INVALID_NEVENTS;
> +	r = do_vcpu_set_pmu_event_filter(vcpu, &f);
> +	TEST_ASSERT(r, "Exceeding the max number of filter events should fail");
> +
> +	f = base_event_filter;
> +	f.fixed_counter_bitmap = ~GENMASK_ULL(nr_fixed_counters, 0);
> +	r = do_vcpu_set_pmu_event_filter(vcpu, &f);
> +	TEST_ASSERT(!r, "Masking non-existent fixed counters should be allowed");
>  }
>  
>  int main(int argc, char *argv[])
> -- 
> 2.39.3
> 

-- 
Isaku Yamahata <isaku.yamahata@gmail.com>