Re: [PATCH v4 3/6] KVM: selftests: Introduce __kvm_pmu_event_filter to improved event filter settings
From: Isaku Yamahata
Date: Tue Jul 18 2023 - 20:03:21 EST
On Mon, Jul 17, 2023 at 02:23:40PM +0800,
Jinrong Liang <ljr.kernel@xxxxxxxxx> wrote:
> From: Jinrong Liang <cloudliang@xxxxxxxxxxx>
>
> Add custom "__kvm_pmu_event_filter" structure to improve pmu event
> filter settings. Simplifies event filter setup by organizing event
> filter parameters in a cleaner, more organized way.
>
> Signed-off-by: Jinrong Liang <cloudliang@xxxxxxxxxxx>
> ---
> .../kvm/x86_64/pmu_event_filter_test.c | 179 +++++++++---------
> 1 file changed, 87 insertions(+), 92 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 5ac05e64bec9..ffcbbf25b29b 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
> @@ -28,6 +28,10 @@
>
> #define NUM_BRANCHES 42
>
> +/* Matches KVM_PMU_EVENT_FILTER_MAX_EVENTS in pmu.c */
> +#define MAX_FILTER_EVENTS 300
> +#define MAX_TEST_EVENTS 10
> +
> /*
> * This is how the event selector and unit mask are stored in an AMD
> * core performance event-select register. Intel's format is similar,
> @@ -69,21 +73,33 @@
>
> #define INST_RETIRED EVENT(0xc0, 0)
>
> +struct __kvm_pmu_event_filter {
> + __u32 action;
> + __u32 nevents;
> + __u32 fixed_counter_bitmap;
> + __u32 flags;
> + __u32 pad[4];
> + __u64 events[MAX_FILTER_EVENTS];
> +};
> +
> /*
> * This event list comprises Intel's eight architectural events plus
> * AMD's "retired branch instructions" for Zen[123] (and possibly
> * other AMD CPUs).
> */
> -static const uint64_t event_list[] = {
> - EVENT(0x3c, 0),
> - INST_RETIRED,
> - EVENT(0x3c, 1),
> - EVENT(0x2e, 0x4f),
> - EVENT(0x2e, 0x41),
> - EVENT(0xc4, 0),
> - EVENT(0xc5, 0),
> - EVENT(0xa4, 1),
> - AMD_ZEN_BR_RETIRED,
> +static const struct __kvm_pmu_event_filter base_event_filter = {
> + .nevents = ARRAY_SIZE(base_event_filter.events),
> + .events = {
> + EVENT(0x3c, 0),
> + INST_RETIRED,
> + EVENT(0x3c, 1),
> + EVENT(0x2e, 0x4f),
> + EVENT(0x2e, 0x41),
> + EVENT(0xc4, 0),
> + EVENT(0xc5, 0),
> + EVENT(0xa4, 1),
> + AMD_ZEN_BR_RETIRED,
> + },
> };
>
> struct {
> @@ -225,47 +241,11 @@ static bool sanity_check_pmu(struct kvm_vcpu *vcpu)
> return !r;
> }
>
> -static struct kvm_pmu_event_filter *alloc_pmu_event_filter(uint32_t nevents)
> -{
> - struct kvm_pmu_event_filter *f;
> - int size = sizeof(*f) + nevents * sizeof(f->events[0]);
> -
> - f = malloc(size);
> - TEST_ASSERT(f, "Out of memory");
> - memset(f, 0, size);
> - f->nevents = nevents;
> - return f;
> -}
> -
> -
> -static struct kvm_pmu_event_filter *
> -create_pmu_event_filter(const uint64_t event_list[], int nevents,
> - uint32_t action, uint32_t flags)
> -{
> - struct kvm_pmu_event_filter *f;
> - int i;
> -
> - f = alloc_pmu_event_filter(nevents);
> - f->action = action;
> - f->flags = flags;
> - for (i = 0; i < nevents; i++)
> - f->events[i] = event_list[i];
> -
> - return f;
> -}
> -
> -static struct kvm_pmu_event_filter *event_filter(uint32_t action)
> -{
> - return create_pmu_event_filter(event_list,
> - ARRAY_SIZE(event_list),
> - action, 0);
> -}
> -
> /*
> * Remove the first occurrence of 'event' (if any) from the filter's
> * event list.
> */
> -static void remove_event(struct kvm_pmu_event_filter *f, uint64_t event)
> +static void remove_event(struct __kvm_pmu_event_filter *f, uint64_t event)
> {
> bool found = false;
> int i;
> @@ -313,66 +293,70 @@ static void test_without_filter(struct kvm_vcpu *vcpu)
> }
>
> static void test_with_filter(struct kvm_vcpu *vcpu,
> - struct kvm_pmu_event_filter *f)
> + struct __kvm_pmu_event_filter *__f)
> {
> + struct kvm_pmu_event_filter *f = (void *)__f;
> +
> vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f);
> run_vcpu_and_sync_pmc_results(vcpu);
> }
>
> static void test_amd_deny_list(struct kvm_vcpu *vcpu)
> {
> - uint64_t event = EVENT(0x1C2, 0);
> - struct kvm_pmu_event_filter *f;
> + struct __kvm_pmu_event_filter f = base_event_filter;
>
> - f = create_pmu_event_filter(&event, 1, KVM_PMU_EVENT_DENY, 0);
> - test_with_filter(vcpu, f);
> - free(f);
> + f.action = KVM_PMU_EVENT_DENY;
> + f.nevents = 1;
> + f.events[0] = EVENT(0x1C2, 0);
> + test_with_filter(vcpu, &f);
This overwrite all members. We can use designated initializer.
struct __kvm_pmu_event_filter f = {
.action = KVM_PMU_EVENT_DENY,
.nevents = 1,
.events = {
EVENT(0x1C2, 0),
},
};
Except this, looks good to me.
Reviewed-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Thanks,
>
> ASSERT_PMC_COUNTING_INSTRUCTIONS();
> }
>
> static void test_member_deny_list(struct kvm_vcpu *vcpu)
> {
> - struct kvm_pmu_event_filter *f = event_filter(KVM_PMU_EVENT_DENY);
> + struct __kvm_pmu_event_filter f = base_event_filter;
>
> - test_with_filter(vcpu, f);
> - free(f);
> + f.action = KVM_PMU_EVENT_DENY;
> + test_with_filter(vcpu, &f);
>
> ASSERT_PMC_NOT_COUNTING_INSTRUCTIONS();
> }
>
> static void test_member_allow_list(struct kvm_vcpu *vcpu)
> {
> - struct kvm_pmu_event_filter *f = event_filter(KVM_PMU_EVENT_ALLOW);
> + struct __kvm_pmu_event_filter f = base_event_filter;
>
> - test_with_filter(vcpu, f);
> - free(f);
> + f.action = KVM_PMU_EVENT_ALLOW;
> + test_with_filter(vcpu, &f);
>
> ASSERT_PMC_COUNTING_INSTRUCTIONS();
> }
>
> static void test_not_member_deny_list(struct kvm_vcpu *vcpu)
> {
> - struct kvm_pmu_event_filter *f = event_filter(KVM_PMU_EVENT_DENY);
> + struct __kvm_pmu_event_filter f = base_event_filter;
> +
> + f.action = KVM_PMU_EVENT_DENY;
>
> - remove_event(f, INST_RETIRED);
> - remove_event(f, INTEL_BR_RETIRED);
> - remove_event(f, AMD_ZEN_BR_RETIRED);
> - test_with_filter(vcpu, f);
> - free(f);
> + remove_event(&f, INST_RETIRED);
> + remove_event(&f, INTEL_BR_RETIRED);
> + remove_event(&f, AMD_ZEN_BR_RETIRED);
> + test_with_filter(vcpu, &f);
>
> ASSERT_PMC_COUNTING_INSTRUCTIONS();
> }
>
> static void test_not_member_allow_list(struct kvm_vcpu *vcpu)
> {
> - struct kvm_pmu_event_filter *f = event_filter(KVM_PMU_EVENT_ALLOW);
> + struct __kvm_pmu_event_filter f = base_event_filter;
>
> - remove_event(f, INST_RETIRED);
> - remove_event(f, INTEL_BR_RETIRED);
> - remove_event(f, AMD_ZEN_BR_RETIRED);
> - test_with_filter(vcpu, f);
> - free(f);
> + f.action = KVM_PMU_EVENT_ALLOW;
> +
> + remove_event(&f, INST_RETIRED);
> + remove_event(&f, INTEL_BR_RETIRED);
> + remove_event(&f, AMD_ZEN_BR_RETIRED);
> + test_with_filter(vcpu, &f);
>
> ASSERT_PMC_NOT_COUNTING_INSTRUCTIONS();
> }
> @@ -567,19 +551,16 @@ static void run_masked_events_test(struct kvm_vcpu *vcpu,
> const uint64_t masked_events[],
> const int nmasked_events)
> {
> - struct kvm_pmu_event_filter *f;
> + struct __kvm_pmu_event_filter f = {
> + .nevents = nmasked_events,
> + .action = KVM_PMU_EVENT_ALLOW,
> + .flags = KVM_PMU_EVENT_FLAG_MASKED_EVENTS,
> + };
>
> - f = create_pmu_event_filter(masked_events, nmasked_events,
> - KVM_PMU_EVENT_ALLOW,
> - KVM_PMU_EVENT_FLAG_MASKED_EVENTS);
> - test_with_filter(vcpu, f);
> - free(f);
> + memcpy(f.events, masked_events, sizeof(uint64_t) * nmasked_events);
> + test_with_filter(vcpu, &f);
> }
>
> -/* Matches KVM_PMU_EVENT_FILTER_MAX_EVENTS in pmu.c */
> -#define MAX_FILTER_EVENTS 300
> -#define MAX_TEST_EVENTS 10
> -
> #define ALLOW_LOADS BIT(0)
> #define ALLOW_STORES BIT(1)
> #define ALLOW_LOADS_STORES BIT(2)
> @@ -751,17 +732,27 @@ static void test_masked_events(struct kvm_vcpu *vcpu)
> run_masked_events_tests(vcpu, events, nevents);
> }
>
> -static int run_filter_test(struct kvm_vcpu *vcpu, const uint64_t *events,
> - int nevents, uint32_t flags)
> +static int do_vcpu_set_pmu_event_filter(struct kvm_vcpu *vcpu,
> + struct __kvm_pmu_event_filter *__f)
> {
> - struct kvm_pmu_event_filter *f;
> - int r;
> + struct kvm_pmu_event_filter *f = (void *)__f;
>
> - 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 __vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f);
> +}
> +
> +static int set_pmu_single_event_filter(struct kvm_vcpu *vcpu, uint64_t event,
> + uint32_t flags, uint32_t action)
> +{
> + struct __kvm_pmu_event_filter f = {
> + .nevents = 1,
> + .flags = flags,
> + .action = action,
> + .events = {
> + event,
> + },
> + };
>
> - return r;
> + return do_vcpu_set_pmu_event_filter(vcpu, &f);
> }
>
> static void test_filter_ioctl(struct kvm_vcpu *vcpu)
> @@ -773,14 +764,18 @@ static void test_filter_ioctl(struct kvm_vcpu *vcpu)
> * 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);
> + r = set_pmu_single_event_filter(vcpu, e, 0, KVM_PMU_EVENT_ALLOW);
> TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing");
>
> - r = run_filter_test(vcpu, &e, 1, KVM_PMU_EVENT_FLAG_MASKED_EVENTS);
> + r = set_pmu_single_event_filter(vcpu, e,
> + KVM_PMU_EVENT_FLAG_MASKED_EVENTS,
> + KVM_PMU_EVENT_ALLOW);
> TEST_ASSERT(r != 0, "Invalid PMU Event Filter is expected to fail");
>
> e = KVM_PMU_ENCODE_MASKED_ENTRY(0xff, 0xff, 0xff, 0xf);
> - r = run_filter_test(vcpu, &e, 1, KVM_PMU_EVENT_FLAG_MASKED_EVENTS);
> + r = set_pmu_single_event_filter(vcpu, e,
> + KVM_PMU_EVENT_FLAG_MASKED_EVENTS,
> + KVM_PMU_EVENT_ALLOW);
> TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing");
> }
>
> --
> 2.39.3
>
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxx>