[v10,2/3] KVM: selftests: aarch64: Introduce pmu_event_filter_test

Introduce pmu_event_filter_test for arm64 platforms. The test configures
PMUv3 for a vCPU, and sets different pmu event filters for the vCPU, and
check if the guest can see those events which user allow and can't use
those events which use deny.

This test refactor the create_vpmu_vm() and make it a wrapper for
__create_vpmu_vm(), which allows some extra init code before
KVM_ARM_VCPU_PMU_V3_INIT.

And this test use the KVM_ARM_VCPU_PMU_V3_FILTER attribute to set the
pmu event filter in KVM. And choose to filter two common event
branches_retired and instructions_retired, and let the guest to check if
it see the right pmceid register.

Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../kvm/aarch64/pmu_event_filter_test.c       | 314 ++++++++++++++++++
 2 files changed, 315 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c

Hi Shaoqin,

On Wed, Jun 19, 2024 at 1:33 AM Shaoqin Huang <shahuang@redhat.com> wrote:
>
> Introduce pmu_event_filter_test for arm64 platforms. The test configures
> PMUv3 for a vCPU, and sets different pmu event filters for the vCPU, and
> check if the guest can see those events which user allow and can't use
> those events which use deny.
>
> This test refactor the create_vpmu_vm() and make it a wrapper for
> __create_vpmu_vm(), which allows some extra init code before
> KVM_ARM_VCPU_PMU_V3_INIT.
>
> And this test use the KVM_ARM_VCPU_PMU_V3_FILTER attribute to set the
> pmu event filter in KVM. And choose to filter two common event
> branches_retired and instructions_retired, and let the guest to check if
> it see the right pmceid register.
>
> Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
> ---
>  tools/testing/selftests/kvm/Makefile          |   1 +
>  .../kvm/aarch64/pmu_event_filter_test.c       | 314 ++++++++++++++++++
>  2 files changed, 315 insertions(+)
>  create mode 100644 tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
>
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index ac280dcba996..2110b49e7a84 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -153,6 +153,7 @@ TEST_GEN_PROGS_aarch64 += aarch64/aarch32_id_regs
>  TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
>  TEST_GEN_PROGS_aarch64 += aarch64/hypercalls
>  TEST_GEN_PROGS_aarch64 += aarch64/page_fault_test
> +TEST_GEN_PROGS_aarch64 += aarch64/pmu_event_filter_test
>  TEST_GEN_PROGS_aarch64 += aarch64/psci_test
>  TEST_GEN_PROGS_aarch64 += aarch64/set_id_regs
>  TEST_GEN_PROGS_aarch64 += aarch64/smccc_filter
> diff --git a/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
> new file mode 100644
> index 000000000000..308b8677e08e
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
> @@ -0,0 +1,314 @@
> +
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * pmu_event_filter_test - Test user limit pmu event for guest.
> + *
> + * Copyright (c) 2023 Red Hat, Inc.
> + *
> + * This test checks if the guest only see the limited pmu event that userspace
> + * sets, if the guest can use those events which user allow, and if the guest
> + * can't use those events which user deny.
> + * This test runs only when KVM_CAP_ARM_PMU_V3, KVM_ARM_VCPU_PMU_V3_FILTER
> + * is supported on the host.
> + */
> +#include <kvm_util.h>
> +#include <processor.h>
> +#include <vgic.h>
> +#include <vpmu.h>
> +#include <test_util.h>
> +#include <perf/arm_pmuv3.h>
> +
> +struct pmu_common_event_ids {
> +       uint64_t pmceid0;
> +       uint64_t pmceid1;
> +} max_pmce, expected_pmce;
> +
> +struct vpmu_vm {
> +       struct kvm_vm *vm;
> +       struct kvm_vcpu *vcpu;
> +       int gic_fd;
> +};
> +
> +static struct vpmu_vm vpmu_vm;
> +
> +#define FILTER_NR 10
> +
> +struct test_desc {
> +       const char *name;
> +       struct kvm_pmu_event_filter filter[FILTER_NR];
> +};
> +
> +#define __DEFINE_FILTER(base, num, act)                \
> +       ((struct kvm_pmu_event_filter) {        \
> +               .base_event     = base,         \
> +               .nevents        = num,          \
> +               .action         = act,          \
> +       })
> +
> +#define DEFINE_FILTER(base, act) __DEFINE_FILTER(base, 1, act)
> +
> +#define EVENT_ALLOW(event)     DEFINE_FILTER(event, KVM_PMU_EVENT_ALLOW)
> +#define EVENT_DENY(event)      DEFINE_FILTER(event, KVM_PMU_EVENT_DENY)
> +
> +static void guest_code(void)
> +{
> +       uint64_t pmceid0 = read_sysreg(pmceid0_el0);
> +       uint64_t pmceid1 = read_sysreg(pmceid1_el0);
> +
> +       GUEST_ASSERT_EQ(expected_pmce.pmceid0, pmceid0);
> +       GUEST_ASSERT_EQ(expected_pmce.pmceid1, pmceid1);
> +
> +       GUEST_DONE();
> +}
> +
> +static void guest_get_pmceid(void)
> +{
> +       max_pmce.pmceid0 = read_sysreg(pmceid0_el0);
> +       max_pmce.pmceid1 = read_sysreg(pmceid1_el0);
> +
> +       GUEST_DONE();
> +}
> +
> +static void run_vcpu(struct kvm_vcpu *vcpu)
> +{
> +       struct ucall uc;
> +
> +       while (1) {
> +               vcpu_run(vcpu);
> +               switch (get_ucall(vcpu, &uc)) {
> +               case UCALL_DONE:
> +                       return;
> +               case UCALL_ABORT:
> +                       REPORT_GUEST_ASSERT(uc);
> +                       break;
> +               default:
> +                       TEST_FAIL("Unknown ucall %lu", uc.cmd);
> +               }
> +       }
> +}
> +
> +static void set_pmce(struct pmu_common_event_ids *pmce, int action, int event)
> +{
> +       int base = 0;
> +       uint64_t *pmceid = NULL;
> +
> +       if (event >= 0x4000) {
> +               event -= 0x4000;
> +               base = 32;
> +       }
> +
> +       if (event >= 0 && event <= 0x1F) {
> +               pmceid = &pmce->pmceid0;
> +       } else if (event >= 0x20 && event <= 0x3F) {
> +               event -= 0x20;
> +               pmceid = &pmce->pmceid1;
> +       } else {
> +               return;
> +       }
> +
> +       event += base;
> +       if (action == KVM_PMU_EVENT_ALLOW)
> +               *pmceid |= BIT(event);
> +       else
> +               *pmceid &= ~BIT(event);
> +}
> +
> +static inline bool is_valid_filter(struct kvm_pmu_event_filter *filter)
> +{
> +       return filter && filter->nevents != 0;
> +}
> +
> +static void prepare_expected_pmce(struct kvm_pmu_event_filter *filter)
> +{
> +       struct pmu_common_event_ids pmce_mask = { ~0, ~0 };
> +       int i;
> +
> +       if (is_valid_filter(filter) && filter->action == KVM_PMU_EVENT_ALLOW)
> +               memset(&pmce_mask, 0, sizeof(pmce_mask));
> +
> +       while (is_valid_filter(filter)) {
> +               for (i = 0; i < filter->nevents; i++)
> +                       set_pmce(&pmce_mask, filter->action,
> +                                filter->base_event + i);
> +               filter++;
> +       }
> +
> +       expected_pmce.pmceid0 = max_pmce.pmceid0 & pmce_mask.pmceid0;
> +       expected_pmce.pmceid1 = max_pmce.pmceid1 & pmce_mask.pmceid1;
> +}
> +
> +static void pmu_event_filter_init(struct kvm_pmu_event_filter *filter)
> +{
> +       while (is_valid_filter(filter)) {
> +               kvm_device_attr_set(vpmu_vm.vcpu->fd,
> +                                   KVM_ARM_VCPU_PMU_V3_CTRL,
> +                                   KVM_ARM_VCPU_PMU_V3_FILTER,
> +                                   filter);
> +               filter++;
> +       }
> +}
> +
> +/* Create a VM that has one vCPU with PMUv3 configured. */
> +static void create_vpmu_vm_with_filter(void *guest_code,
> +                                      struct kvm_pmu_event_filter *filter)
> +{
> +       uint64_t irq = 23;
> +
> +       /* The test creates the vpmu_vm multiple times. Ensure a clean state */
> +       memset(&vpmu_vm, 0, sizeof(vpmu_vm));
> +
> +       vpmu_vm.vm = vm_create(1);
> +       vpmu_vm.vcpu = vm_vcpu_add_with_vpmu(vpmu_vm.vm, 0, guest_code);
> +       vpmu_vm.gic_fd = vgic_v3_setup(vpmu_vm.vm, 1, 64);
> +       __TEST_REQUIRE(vpmu_vm.gic_fd >= 0,
> +                      "Failed to create vgic-v3, skipping");
> +
> +       pmu_event_filter_init(filter);
> +
> +       /* Initialize vPMU */
> +       vpmu_set_irq(vpmu_vm.vcpu, irq);
> +       vpmu_init(vpmu_vm.vcpu);
> +}
> +
> +static void create_vpmu_vm(void *guest_code)
> +{
> +       create_vpmu_vm_with_filter(guest_code, NULL);
> +}
> +
> +static void destroy_vpmu_vm(void)
> +{
> +       close(vpmu_vm.gic_fd);
> +       kvm_vm_free(vpmu_vm.vm);
> +}
> +
> +static void run_test(struct test_desc *t)
> +{
> +       pr_info("Test: %s\n", t->name);
> +
> +       create_vpmu_vm_with_filter(guest_code, t->filter);
> +       prepare_expected_pmce(t->filter);
> +       sync_global_to_guest(vpmu_vm.vm, expected_pmce);
> +
> +       run_vcpu(vpmu_vm.vcpu);
> +
> +       destroy_vpmu_vm();
> +}
> +
> +static struct test_desc tests[] = {
> +       {
> +               .name = "without_filter",
> +               .filter = {
> +                       { 0 }
> +               },
> +       },
> +       {
> +               .name = "member_allow_filter",
> +               .filter = {
> +                       EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_SW_INCR),
> +                       EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_INST_RETIRED),
> +                       EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_BR_RETIRED),
> +                       { 0 },
> +               },
> +       },
> +       {
> +               .name = "member_deny_filter",
> +               .filter = {
> +                       EVENT_DENY(ARMV8_PMUV3_PERFCTR_SW_INCR),
> +                       EVENT_DENY(ARMV8_PMUV3_PERFCTR_INST_RETIRED),
> +                       EVENT_DENY(ARMV8_PMUV3_PERFCTR_BR_RETIRED),
> +                       { 0 },
> +               },
> +       },
> +       {
> +               .name = "not_member_deny_filter",
> +               .filter = {
> +                       EVENT_DENY(ARMV8_PMUV3_PERFCTR_SW_INCR),
> +                       { 0 },
> +               },
> +       },
> +       {
> +               .name = "not_member_allow_filter",
> +               .filter = {
> +                       EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_SW_INCR),
> +                       { 0 },
> +               },
> +       },
> +       {
> +               .name = "deny_chain_filter",
> +               .filter = {
> +                       EVENT_DENY(ARMV8_PMUV3_PERFCTR_CHAIN),
> +                       { 0 },
> +               },
> +       },
> +       {
> +               .name = "deny_cpu_cycles_filter",
> +               .filter = {
> +                       EVENT_DENY(ARMV8_PMUV3_PERFCTR_CPU_CYCLES),
> +                       { 0 },
> +               },
> +       },
> +       {
> +               .name = "cancel_allow_filter",
> +               .filter = {
> +                       EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_CPU_CYCLES),
> +                       EVENT_DENY(ARMV8_PMUV3_PERFCTR_CPU_CYCLES),
> +               },
> +       },
> +       {
> +               .name = "cancel_deny_filter",
> +               .filter = {
> +                       EVENT_DENY(ARMV8_PMUV3_PERFCTR_CPU_CYCLES),
> +                       EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_CPU_CYCLES),
> +               },
> +       },
> +       {
> +               .name = "multiple_filter",
> +               .filter = {
> +                       __DEFINE_FILTER(0x0, 0x10, KVM_PMU_EVENT_ALLOW),
> +                       __DEFINE_FILTER(0x6, 0x3, KVM_PMU_EVENT_DENY),
> +               },
> +       },
> +       { 0 }
> +};
> +
> +static void run_tests(void)
> +{
> +       struct test_desc *t;
> +
> +       for (t = &tests[0]; t->name; t++)
> +               run_test(t);
> +}
> +
> +static int used_pmu_events[] = {
> +       ARMV8_PMUV3_PERFCTR_BR_RETIRED,
> +       ARMV8_PMUV3_PERFCTR_INST_RETIRED,
> +       ARMV8_PMUV3_PERFCTR_CHAIN,
> +       ARMV8_PMUV3_PERFCTR_CPU_CYCLES,
> +};
> +
> +static bool kvm_pmu_support_events(void)
> +{
> +       struct pmu_common_event_ids used_pmce = { 0, 0 };
> +
> +       create_vpmu_vm(guest_get_pmceid);
> +
> +       memset(&max_pmce, 0, sizeof(max_pmce));
> +       sync_global_to_guest(vpmu_vm.vm, max_pmce);
> +       run_vcpu(vpmu_vm.vcpu);
> +       sync_global_from_guest(vpmu_vm.vm, max_pmce);
> +       destroy_vpmu_vm();
> +
> +       for (int i = 0; i < ARRAY_SIZE(used_pmu_events); i++)
> +               set_pmce(&used_pmce, KVM_PMU_EVENT_ALLOW, used_pmu_events[i]);
> +
> +       return ((max_pmce.pmceid0 & used_pmce.pmceid0) == used_pmce.pmceid0) &&
> +              ((max_pmce.pmceid1 & used_pmce.pmceid1) == used_pmce.pmceid1);
> +}
> +
> +int main(void)
> +{
> +       TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_PMU_V3));
> +       TEST_REQUIRE(kvm_pmu_support_events());
> +
> +       run_tests();
> +}
> --
> 2.40.1
>
>
Reviewed-by: Raghavendra Rao Ananta <rananta@google.com>

- Raghavendra