[v6,3/6] KVM: selftests: Introduce __kvm_pmu_event_filter to improved event filter settings

Commit Message

Jinrong Liang Aug. 10, 2023, 9:09 a.m. UTC

From: Jinrong Liang <[e-mail]>

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.

Suggested-by: Sean Christopherson <[e-mail]>
Signed-off-by: Jinrong Liang <[e-mail]>
---
 .../kvm/x86_64/pmu_event_filter_test.c        | 182 +++++++++---------
 1 file changed, 90 insertions(+), 92 deletions(-)

Comments

Jinrong Liang Aug. 11, 2023, 3:09 a.m. UTC | #1

在 2023/8/10 17:09, Jinrong Liang 写道:
> From: Jinrong Liang <[e-mail]>
> 
> 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.

I apologize for the oversight in this patch submission. I forgot to 
include the "Reviewed-by" tag. Please find the updated information below:

Reviewed-by: Isaku Yamahata <[e-mail]>

When reviewing the patch, please take this tag into account.

> 
> Suggested-by: Sean Christopherson <[e-mail]>
> Signed-off-by: Jinrong Liang <[e-mail]>
> ---
>   .../kvm/x86_64/pmu_event_filter_test.c        | 182 +++++++++---------
>   1 file changed, 90 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..94f5a89aac40 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 +293,73 @@ 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 = {
> +		.action = KVM_PMU_EVENT_DENY,
> +		.nevents = 1,
> +		.events = {
> +			EVENT(0x1C2, 0),
> +		},
> +	};
>   
> -	f = create_pmu_event_filter(&event, 1, KVM_PMU_EVENT_DENY, 0);
> -	test_with_filter(vcpu, f);
> -	free(f);
> +	test_with_filter(vcpu, &f);
>   
>   	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;
>   
> -	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_DENY;
> +
> +	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;
> +
> +	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);
> -	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_NOT_COUNTING_INSTRUCTIONS();
>   }
> @@ -567,19 +554,16 @@ 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 +735,27 @@ 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 +767,18 @@ 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");
>   }
>

Isaku Yamahata Aug. 14, 2023, 11:49 p.m. UTC | #2

On Thu, Aug 10, 2023 at 05:09:42PM +0800,
Jinrong Liang <[e-mail]> wrote:

> From: Jinrong Liang <[e-mail]>
> 
> 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.
> 
> Suggested-by: Sean Christopherson <[e-mail]>
> Signed-off-by: Jinrong Liang <[e-mail]>
> ---
>  .../kvm/x86_64/pmu_event_filter_test.c        | 182 +++++++++---------
>  1 file changed, 90 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..94f5a89aac40 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

Can we simply use KVM_PMU_EVENT_FILTER_MAX_EVENTS and remove MAX_FILTER_EVENTS?


> +#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];
> +};
> +

Is this same to struct kvm_pmu_event_filter?

Except two trivial issue, looks good to me.

Jinrong Liang Aug. 15, 2023, 3:41 a.m. UTC | #3

Isaku Yamahata <[e-mail]> 于2023年8月15日周二 07:49写道：
>
> On Thu, Aug 10, 2023 at 05:09:42PM +0800,
> Jinrong Liang <[e-mail]> wrote:
>
> > From: Jinrong Liang <[e-mail]>
> >
> > 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.
> >
> > Suggested-by: Sean Christopherson <[e-mail]>
> > Signed-off-by: Jinrong Liang <[e-mail]>
> > ---
> >  .../kvm/x86_64/pmu_event_filter_test.c        | 182 +++++++++---------
> >  1 file changed, 90 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..94f5a89aac40 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
>
> Can we simply use KVM_PMU_EVENT_FILTER_MAX_EVENTS and remove MAX_FILTER_EVENTS?

I didn't find the definition of KVM_PMU_EVENT_FILTER_MAX_EVENTS in
selftests. KVM_PMU_EVENT_FILTER_MAX_EVENTS is defined in pmu.c. To use
it, we need to define it in selftests.

>
>
> > +#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];
> > +};
> > +
>
> Is this same to struct kvm_pmu_event_filter?

In tools/arch/x86/include/uapi/asm/kvm.h

/* for KVM_CAP_PMU_EVENT_FILTER */
struct kvm_pmu_event_filter {
__u32 action;
__u32 nevents;
__u32 fixed_counter_bitmap;
__u32 flags;
__u32 pad[4];
__u64 events[];
};

>
> Except two trivial issue, looks good to me.
> --
> Isaku Yamahata <[e-mail]>

Sean Christopherson Aug. 17, 2023, 8:17 p.m. UTC | #4

On Tue, Aug 15, 2023, Jinrong Liang wrote:
> Isaku Yamahata <[e-mail]> 于2023年8月15日周二 07:49写道：
> >
> > On Thu, Aug 10, 2023 at 05:09:42PM +0800,
> > Jinrong Liang <[e-mail]> wrote:
> >
> > > From: Jinrong Liang <[e-mail]>
> > >
> > > 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.
> > >
> > > Suggested-by: Sean Christopherson <[e-mail]>
> > > Signed-off-by: Jinrong Liang <[e-mail]>
> > > ---
> > >  .../kvm/x86_64/pmu_event_filter_test.c        | 182 +++++++++---------
> > >  1 file changed, 90 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..94f5a89aac40 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
> >
> > Can we simply use KVM_PMU_EVENT_FILTER_MAX_EVENTS and remove MAX_FILTER_EVENTS?
> 
> I didn't find the definition of KVM_PMU_EVENT_FILTER_MAX_EVENTS in
> selftests. KVM_PMU_EVENT_FILTER_MAX_EVENTS is defined in pmu.c. To use
> it, we need to define it in selftests.

Huh.  That seems like something that should be enumerated to userspace.

> > > +#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];
> > > +};
> > > +
> >
> > Is this same to struct kvm_pmu_event_filter?
> 
> In tools/arch/x86/include/uapi/asm/kvm.h
> 
> /* for KVM_CAP_PMU_EVENT_FILTER */
> struct kvm_pmu_event_filter {
> __u32 action;
> __u32 nevents;
> __u32 fixed_counter_bitmap;
> __u32 flags;
> __u32 pad[4];
> __u64 events[];
> };

To more directly answer Isaku's question:

They're *basically* the same, and have an identical layout, but the struct defined
by KVM uses a flexible array because the number of events comes from userspace
and forcing userspace to create an 1KiB+ object just to define a single event
filter would be obnoxious.

There are alternatives, e.g. using an struct overlay to set a single entry:

	struct {
		struct kvm_msrs header;
		struct kvm_msr_entry entry;
	} buffer = {};

	memset(&buffer, 0, sizeof(buffer));
	buffer.header.nmsrs = 1;
	buffer.entry.index = msr_index;
	buffer.entry.data = msr_value;

but that gets annoying (and IMO confusing) because of the nested structs.

I'll massage the changelog to callout the alternative, and why it's undesirable.

Sean Christopherson Aug. 17, 2023, 8:53 p.m. UTC | #5

On Thu, Aug 10, 2023, Jinrong Liang wrote:
> -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)

Just "set_pmu_event_filter()" please.  The "do" is pointless, and the "vcpu" part
is confusing since the filter is per-VM, the selftest just happens to pass around
the vCPU.  And to be consistent with set_pmu_single_event_filter().

No need for a new version, I'll fixup when applying.

Patch

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..94f5a89aac40 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 +293,73 @@  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 = {
+		.action = KVM_PMU_EVENT_DENY,
+		.nevents = 1,
+		.events = {
+			EVENT(0x1C2, 0),
+		},
+	};
 
-	f = create_pmu_event_filter(&event, 1, KVM_PMU_EVENT_DENY, 0);
-	test_with_filter(vcpu, f);
-	free(f);
+	test_with_filter(vcpu, &f);
 
 	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;
 
-	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_DENY;
+
+	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;
+
+	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);
-	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_NOT_COUNTING_INSTRUCTIONS();
 }
@@ -567,19 +554,16 @@  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 +735,27 @@  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 +767,18 @@  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");
 }