On Wed, Aug 31, 2022 at 9:21 AM Aaron Lewis <aaronlewis@xxxxxxxxxx> wrote:
>
> Test that masked events are not using invalid bits, and if they are,
> ensure the pmu event filter is not accepted by KVM_SET_PMU_EVENT_FILTER.
> The only valid bits that can be used for masked events are set when
> using KVM_PMU_EVENT_ENCODE_MASKED_EVENT() with one exception: If any
> of the high bits (11:8) of the event select are set when using Intel,
> the PMU event filter will fail.
>
> Also, because validation was not being done prior to the introduction
> of masked events, only expect validation to fail when masked events
> are used. E.g. in the first test a filter event with all it's bits set
Nit: its
> is accepted by KVM_SET_PMU_EVENT_FILTER when flags = 0.
>
> Signed-off-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
> ---
> .../kvm/x86_64/pmu_event_filter_test.c | 35 +++++++++++++++++++
> 1 file changed, 35 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 bd7054a53981..73a81262ca72 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
> @@ -442,6 +442,39 @@ static bool use_amd_pmu(void)
> is_zen3(entry->eax));
> }
>
> +static int run_filter_test(struct kvm_vcpu *vcpu, const uint64_t *events,
> + int nevents, uint32_t flags)
> +{
> + struct kvm_pmu_event_filter *f;
> + int r;
> +
> + f = create_pmu_event_filter(events, nevents, KVM_PMU_EVENT_ALLOW, flags);
> + r = __vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f);
> + free(f);
> +
> + return r;
> +}
> +
> +static void test_filter_ioctl(struct kvm_vcpu *vcpu)
> +{
> + uint64_t e = ~0ul;
> + int r;
> +
> + /*
> + * Unfortunately having invalid bits set in event data is expected to
> + * pass when flags == 0 (bits other than eventsel+umask).
> + */
> + r = run_filter_test(vcpu, &e, 1, 0);
> + TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing");
> +
> + r = run_filter_test(vcpu, &e, 1, KVM_PMU_EVENT_FLAG_MASKED_EVENTS);
Before using KVM_PMU_EVENT_FLAG_MASKED_EVENTS, we need to test for
KVM_CAP_PMU_EVENT_MASKED_EVENTS.
