On Wed, Jun 07, 2023, Jinrong Liang wrote:
> From: Jinrong Liang <cloudliang@xxxxxxxxxxx>
>
> This commit adds test cases for unsupported input values in the
Avoid "this commit" and "this patch", simply state what the patch does as a
command, e.g. "Add test cases for ...".
> 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. Additionally, the patch tests setting
> non-exist fixed counters in the fixed bitmap doesn't fail.
>
> Signed-off-by: Jinrong Liang <cloudliang@xxxxxxxxxxx>
> ---
> .../kvm/x86_64/pmu_event_filter_test.c | 48 +++++++++++++++++--
> 1 file changed, 45 insertions(+), 3 deletions(-)
>
> 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 26f674c32cde..7555e0f4290c 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
> @@ -11,9 +11,7 @@
> */
>
> #define _GNU_SOURCE /* for program_invocation_short_name */
> -#include "test_util.h"
> -#include "kvm_util.h"
> -#include "processor.h"
> +#include "pmu.h"
>
> /*
> * In lieu of copying perf_event.h into tools...
> @@ -32,6 +30,10 @@
> #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)
> +#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,
> @@ -762,6 +764,7 @@ static void test_filter_ioctl(struct kvm_vcpu *vcpu)
> {
> uint64_t e = ~0ul;
> int r;
> + struct __kvm_pmu_event_filter f;
Reverse xmas tree.
>
> /*
> * Unfortunately having invalid bits set in event data is expected to
> @@ -780,6 +783,45 @@ 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");
> +
> + /*
> + * Testing unsupported "action" input values should return an error.
Omit the "Testing", KVM's behavior isn't specific to "testing", any unsupported
action should fail.
/* Unsupported actions should be rejected by KVM. */
Though honestly, I would forego the comments entirely, the macro name plus the
assert make it quite clear what's being tested.
> + * Currently, only values 0 or 1 are supported.
Drop this part of the comment, it will become stale if PMU_EVENT_FILTER_INVALID_ACTION
is modified, and readers can look at the definition of PMU_EVENT_FILTER_INVALID_ACTION
if they really care about the actual value.
> + */
> + f = base_event_filter;
> + f.action = PMU_EVENT_FILTER_INVALID_ACTION;
> + r = do_vcpu_set_pmu_event_filter(vcpu, &f);
> + TEST_ASSERT(r != 0, "Set invalid action is expected to fail.");
Ignore the bad precedent set by this test, the preferred way to check for 0 and
!0 is TEST_ASSERT(r, ...) and TEST_ASSERT(!r, ...);
And no punctuation in the assert, i.e. drop the period.
> +
> + /*
> + * Testing unsupported "flags" input values should return an error.
> + * Currently, only values 0 or 1 are supported.
> + */
Same here.
> + f = base_event_filter;
> + f.flags = PMU_EVENT_FILTER_INVALID_FLAGS;
> + r = do_vcpu_set_pmu_event_filter(vcpu, &f);
> + TEST_ASSERT(r != 0, "Set invalid flags is expected to fail.");
> +
> + /*
> + * Testing unsupported "nevents" input values should return an error.
> + * Currently, only values less than or equal to
> + * MAX_FILTER_EVENTS are supported.
And here.
> + */
> + f = base_event_filter;
> + f.nevents = PMU_EVENT_FILTER_INVALID_NEVENTS;
> + r = do_vcpu_set_pmu_event_filter(vcpu, &f);
> + TEST_ASSERT(r != 0,
> + "Setting PMU event filters that exceeds the maximum supported value should fail");
To avoid splitting lines,
TEST_ASSERT(r, "Exceeding the max number of filter events should fail");
> +
> + /*
> + * In this case, setting non-exist fixed counters in the fixed bitmap
> + * doesn't fail.
> + */
And here.
> + f = base_event_filter;
> + f.fixed_counter_bitmap = ~GENMASK_ULL(X86_INTEL_MAX_FIXED_CTR_NUM, 0);
> + r = do_vcpu_set_pmu_event_filter(vcpu, &f);
> + TEST_ASSERT(r == 0,
> + "Setting invalid or non-exist fixed cunters in the fixed bitmap fail.");
Something like so to avoid multiple lines.
TEST_ASSERT(!r, "Masking non-existent fixed counters should be allowed");
