[PATCH v7 2/3] KVM: selftests: aarch64: Introduce pmu_event_filter_test
Shaoqin Huang
shahuang at redhat.com
Thu May 9 00:34:25 PDT 2024
Hi Eric,
On 5/7/24 16:45, Eric Auger wrote:
> Hi Shaoqin,
>
> On 4/9/24 05:03, Shaoqin Huang 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 at redhat.com>
>> ---
>> tools/testing/selftests/kvm/Makefile | 1 +
>> .../kvm/aarch64/pmu_event_filter_test.c | 298 ++++++++++++++++++
>> 2 files changed, 299 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 741c7dc16afc..9745be534df3 100644
>> --- a/tools/testing/selftests/kvm/Makefile
>> +++ b/tools/testing/selftests/kvm/Makefile
>> @@ -151,6 +151,7 @@ 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..972384e81067
>> --- /dev/null
>> +++ b/tools/testing/selftests/kvm/aarch64/pmu_event_filter_test.c
>> @@ -0,0 +1,298 @@
>> +
>> +// 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)
>> +
>> +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 void prepare_expected_pmce(struct kvm_pmu_event_filter *filter)
>> +{
>> + struct pmu_common_event_ids pmce_mask = { ~0, ~0 };
>> + bool first_filter = true;
>> + int i;
>> +
>> + while (filter && filter->nevents != 0) {
>> + if (first_filter) {
>> + if (filter->action == KVM_PMU_EVENT_ALLOW)
>> + memset(&pmce_mask, 0, sizeof(pmce_mask));
>> + first_filter = false;
>> + }
>> +
>> + 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 (filter && filter->nevents != 0) {
>> + kvm_device_attr_set(vpmu_vm.vcpu->fd,
>> + KVM_ARM_VCPU_PMU_V3_CTRL,
>> + KVM_ARM_VCPU_PMU_V3_FILTER,
>> + filter);
>> + filter++;
>> + }
>> +}
>> +
>> +#define GICD_BASE_GPA 0x8000000ULL
>> +#define GICR_BASE_GPA 0x80A0000ULL
> in v4 Oliver suggested "Shouldn't a standardized layout of the GIC
> frames go with the rest of the GIC stuff?"
>
Oliver replied there is another commits did that, so I will remove them
when I update it.
>> +
>> +/* 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,
>> + GICD_BASE_GPA, GICR_BASE_GPA);
>> + __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 = {
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_SW_INCR, 0),
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_INST_RETIRED, 0),
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_BR_RETIRED, 0),
>> + { 0 },
>> + },
>> + },
>> + {
>> + .name = "member_deny_filter",
>> + .filter = {
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_SW_INCR, 1),
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_INST_RETIRED, 1),
>> + DEFINE_FILTERShouldn't a standardized layout of the GIC frames go with the rest of
> the GIC stuff?(ARMV8_PMUV3_PERFCTR_BR_RETIRED, 1),
>> + { 0 },
>> + },
>> + },
>> + {
>> + .name = "not_member_deny_filter",
>> + .filter = {
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_SW_INCR, 1),
>> + { 0 },
>> + },
>> + },
>> + {
>> + .name = "not_member_allow_filter",
>> + .filter = {
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_SW_INCR, 0),
>> + { 0 },
>> + },
>> + },
>> + {
>> + .name = "deny_chain_filter",
>> + .filter = {
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_CHAIN, 1),
>> + { 0 },
>> + },
>> + },
>> + {
>> + .name = "deny_cpu_cycles_filter",
>> + .filter = {
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_CPU_CYCLES, 1),
>> + { 0 },
>> + },
>> + },
>> + {
>> + .name = "cancel_filter",
>> + .filter = {
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_CPU_CYCLES, 0),
>> + DEFINE_FILTER(ARMV8_PMUV3_PERFCTR_CPU_CYCLES, 1),
>> + },
>> + },
>> + {
>> + .name = "multiple_filter",
>> + .filter = {
>> + __DEFINE_FILTER(0x0, 0x10, 0),
>> + __DEFINE_FILTER(0x6, 0x3, 1),
>> + },
>> + },
>> + { 0 }
>> +};
>> +
>> +static void run_tests(void)
>> +{
>> + struct test_desc *t;
>> +
>> + for (t = &tests[0]; t->name; t++)
>> + run_test(t);
>> +}
>> +
>> +static bool kvm_pmu_support_events(void)
>> +{
>> + 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();
>> +
>> + return max_pmce.pmceid0 &
>> + (ARMV8_PMUV3_PERFCTR_BR_RETIRED |
>> + ARMV8_PMUV3_PERFCTR_INST_RETIRED |
>> + ARMV8_PMUV3_PERFCTR_CHAIN);
> those are not bit masks but bit shifts. Also don't you want to test that
> all of them are supported?
Thanks for catching this bug. Yes I want to test all of them are
supported but wrongly checking the bit masks. I will fix them.
>
> BR_RETIRED is 0x21 so doesn't it belong to pmceid1?
Yes, it should belong to pmceid1. But my wrong checking didn't help me
find it. Thanks a lot.
>
>
> in v4 Oliver suggested to use sysfs instead of spawning a scratch VM.
In that version I changed to function name to kvm_pmu_support_events,
which means I want to detect what the KVM supports about the PMU events
rather than the host supportted PMU events. I think that would be more
suitable if we test KVM.
Thanks,
Shaoqin
>> +}
>> +
>> +int main(void)
>> +{
>> + TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_PMU_V3));
>> + TEST_REQUIRE(kvm_pmu_support_events());
>> +
>> + run_tests();
>> +}
> Eric
>
--
Shaoqin
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