From patchwork Mon Feb 13 18:02:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Raghavendra Rao Ananta X-Patchwork-Id: 13138764 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F6B8C6379F for ; Mon, 13 Feb 2023 18:03:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231200AbjBMSDO (ORCPT ); Mon, 13 Feb 2023 13:03:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231124AbjBMSCz (ORCPT ); Mon, 13 Feb 2023 13:02:55 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D08FA1EFFB for ; Mon, 13 Feb 2023 10:02:46 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id z9-20020a25ba49000000b007d4416e3667so13389471ybj.23 for ; Mon, 13 Feb 2023 10:02:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=b4AB06q1cmw2xfepDKSJYP3pCnth/5v7kXmR5lfk+6U=; b=fXK9ReETXPS2j77ugkcwz+WisHJJl30nYulVnC5wPiVkGYG2emzbPoAyLynH7ZaAsI 1c3LfWRVQ6iewmxzt1Wg3dcqrIbv7kvBuFrhDdqtN0ITzFnMcZNSuWr+0SY6Kw1+o/FR szzw1tiwapnZbgthXSx/Q5fTtv96fLq+VqsfNBqsKWqMyUmVfxhQ7HqAbJNxSJzNGvs+ CqH2iEfuDdAD+suKAproIohuUCyyo1DeIRtwQxE1WZ193pQLMzCrkXd/oJGU2pJpvoMD KS3jlG86kbYxGFvTrXi5TTvOLQarjIK+MQliKVXkQg6GClJdDqpSaaeT1GDu/N1b4QVv jK6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=b4AB06q1cmw2xfepDKSJYP3pCnth/5v7kXmR5lfk+6U=; b=boEs2mcn4BKDhSePPpX2tdLdGb4G92vF8PiXS6fRN3kB8c5mVIsdJwNc4q0pGesdG2 9J8FMeH7+j7gx1/VssBndR/+6EMlexZHNJ7OCXLRBV/l0nqClqwCqQ+ZKCH4jp8uH4Mj pDJ3M7ueiMiugj2qzuY2cBZ7pJDTAaqVtnewoxZMZp7v7zsEmtG9bqcLDoDsNy/lka0U kWOt8SKzgFZCnlWjVYBzOZIC7sXyLUr7m27JaTOuRv2jVTxImUKBiRS46kPMb+GTVjSs VVuRxA7EKAUz6z8sCKaSg5LDte8hCUXeZ6ivOR0xVPA37XLUiVGgLX+Id7WDx3lqR2Uq kLPw== X-Gm-Message-State: AO0yUKUzSPN476+qNcxSX5tX9yyABOpMdJpr3pxaShbwqONGYZcb+1kW gfCHWRavJ1kWXhnvy+tHex0bWlJryktm X-Google-Smtp-Source: AK7set9x9mJnUYIPvLaxq+mW4hkjTEtu0lhCvSA8e5Al797fNHvzz7ZeDQoXvhWboY/INSxnq62Zmi3F8bIn X-Received: from rananta-linux.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:22b5]) (user=rananta job=sendgmr) by 2002:a0d:eac3:0:b0:52e:c5c0:1d0e with SMTP id t186-20020a0deac3000000b0052ec5c01d0emr1538030ywe.418.1676311366096; Mon, 13 Feb 2023 10:02:46 -0800 (PST) Date: Mon, 13 Feb 2023 18:02:27 +0000 In-Reply-To: <20230213180234.2885032-1-rananta@google.com> Mime-Version: 1.0 References: <20230213180234.2885032-1-rananta@google.com> X-Mailer: git-send-email 2.39.1.581.gbfd45094c4-goog Message-ID: <20230213180234.2885032-7-rananta@google.com> Subject: [PATCH 06/13] selftests: KVM: aarch64: Add KVM PMU event filter test From: Raghavendra Rao Ananta To: Oliver Upton , Reiji Watanabe , Marc Zyngier , Ricardo Koller , James Morse , Suzuki K Poulose Cc: Paolo Bonzini , Jing Zhang , Colton Lewis , Raghavendra Rao Anata , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Add tests to validate KVM's KVM_ARM_VCPU_PMU_V3_FILTER attribute by applying a series of filters to allow or deny events from the userspace. Validation is done by the guest in a way that it should be able to count only the events that are allowed. The workload to execute a precise number of instructions (execute_precise_instrs() and precise_instrs_loop()) is taken from the kvm-unit-tests' arm/pmu.c. Signed-off-by: Raghavendra Rao Ananta --- .../testing/selftests/kvm/aarch64/vpmu_test.c | 261 +++++++++++++++++- 1 file changed, 258 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/aarch64/vpmu_test.c b/tools/testing/selftests/kvm/aarch64/vpmu_test.c index 2b3a4fa3afa9c..3dfb770b538e9 100644 --- a/tools/testing/selftests/kvm/aarch64/vpmu_test.c +++ b/tools/testing/selftests/kvm/aarch64/vpmu_test.c @@ -2,12 +2,21 @@ /* * vpmu_test - Test the vPMU * - * Copyright (c) 2022 Google LLC. + * The test suit contains a series of checks to validate the vPMU + * functionality. This test runs only when KVM_CAP_ARM_PMU_V3 is + * supported on the host. The tests include: * - * This test checks if the guest can see the same number of the PMU event + * 1. Check if the guest can see the same number of the PMU event * counters (PMCR_EL0.N) that userspace sets, if the guest can access * those counters, and if the guest cannot access any other counters. - * This test runs only when KVM_CAP_ARM_PMU_V3 is supported on the host. + * + * 2. Test the functionality of KVM's KVM_ARM_VCPU_PMU_V3_FILTER + * attribute by applying a series of filters in various combinations + * of allowing or denying the events. The guest validates it by + * checking if it's able to count only the events that are allowed. + * + * Copyright (c) 2022 Google LLC. + * */ #include #include @@ -230,6 +239,12 @@ struct pmc_accessor pmc_accessors[] = { #define MAX_EVENT_FILTERS_PER_VM 10 +#define EVENT_ALLOW(ev) \ + {.base_event = ev, .nevents = 1, .action = KVM_PMU_EVENT_ALLOW} + +#define EVENT_DENY(ev) \ + {.base_event = ev, .nevents = 1, .action = KVM_PMU_EVENT_DENY} + #define INVALID_EC (-1ul) uint64_t expected_ec = INVALID_EC; uint64_t op_end_addr; @@ -243,11 +258,13 @@ struct vpmu_vm { enum test_stage { TEST_STAGE_COUNTER_ACCESS = 1, + TEST_STAGE_KVM_EVENT_FILTER, }; struct guest_data { enum test_stage test_stage; uint64_t expected_pmcr_n; + unsigned long *pmu_filter; }; static struct guest_data guest_data; @@ -329,6 +346,113 @@ static bool pmu_event_is_supported(uint64_t event) GUEST_ASSERT_3(!(_tval & mask), _tval, mask, set_expected);\ } + +/* + * Extra instructions inserted by the compiler would be difficult to compensate + * for, so hand assemble everything between, and including, the PMCR accesses + * to start and stop counting. isb instructions are inserted to make sure + * pmccntr read after this function returns the exact instructions executed + * in the controlled block. Total instrs = isb + nop + 2*loop = 2 + 2*loop. + */ +static inline void precise_instrs_loop(int loop, uint32_t pmcr) +{ + uint64_t pmcr64 = pmcr; + + asm volatile( + " msr pmcr_el0, %[pmcr]\n" + " isb\n" + "1: subs %w[loop], %w[loop], #1\n" + " b.gt 1b\n" + " nop\n" + " msr pmcr_el0, xzr\n" + " isb\n" + : [loop] "+r" (loop) + : [pmcr] "r" (pmcr64) + : "cc"); +} + +/* + * Execute a known number of guest instructions. Only even instruction counts + * greater than or equal to 4 are supported by the in-line assembly code. The + * control register (PMCR_EL0) is initialized with the provided value (allowing + * for example for the cycle counter or event counters to be reset). At the end + * of the exact instruction loop, zero is written to PMCR_EL0 to disable + * counting, allowing the cycle counter or event counters to be read at the + * leisure of the calling code. + */ +static void execute_precise_instrs(int num, uint32_t pmcr) +{ + int loop = (num - 2) / 2; + + GUEST_ASSERT_2(num >= 4 && ((num - 2) % 2 == 0), num, loop); + precise_instrs_loop(loop, pmcr); +} + +static void test_instructions_count(int pmc_idx, bool expect_count) +{ + int i; + struct pmc_accessor *acc; + uint64_t cnt; + int instrs_count = 100; + + enable_counter(pmc_idx); + + /* Test the event using all the possible way to configure the event */ + for (i = 0; i < ARRAY_SIZE(pmc_accessors); i++) { + acc = &pmc_accessors[i]; + + pmu_disable_reset(); + + acc->write_typer(pmc_idx, ARMV8_PMUV3_PERFCTR_INST_RETIRED); + + /* Enable the PMU and execute precisely number of instructions as a workload */ + execute_precise_instrs(instrs_count, read_sysreg(pmcr_el0) | ARMV8_PMU_PMCR_E); + + /* If a count is expected, the counter should be increased by 'instrs_count' */ + cnt = acc->read_cntr(pmc_idx); + GUEST_ASSERT_4(expect_count == (cnt == instrs_count), + i, expect_count, cnt, instrs_count); + } + + disable_counter(pmc_idx); +} + +static void test_cycles_count(bool expect_count) +{ + uint64_t cnt; + + pmu_enable(); + reset_cycle_counter(); + + /* Count cycles in EL0 and EL1 */ + write_pmccfiltr(0); + enable_cycle_counter(); + + cnt = read_cycle_counter(); + + /* + * If a count is expected by the test, the cycle counter should be increased by + * at least 1, as there is at least one instruction between enabling the + * counter and reading the counter. + */ + GUEST_ASSERT_2(expect_count == (cnt > 0), cnt, expect_count); + + disable_cycle_counter(); + pmu_disable_reset(); +} + +static void test_event_count(uint64_t event, int pmc_idx, bool expect_count) +{ + switch (event) { + case ARMV8_PMUV3_PERFCTR_INST_RETIRED: + test_instructions_count(pmc_idx, expect_count); + break; + case ARMV8_PMUV3_PERFCTR_CPU_CYCLES: + test_cycles_count(expect_count); + break; + } +} + /* * Check if @mask bits in {PMCNTEN,PMINTEN,PMOVS}{SET,CLR} registers * are set or cleared as specified in @set_expected. @@ -532,12 +656,37 @@ static void guest_counter_access_test(uint64_t expected_pmcr_n) } } +static void guest_event_filter_test(unsigned long *pmu_filter) +{ + uint64_t event; + + /* + * Check if PMCEIDx_EL0 is advertized as configured by the userspace. + * It's possible that even though the userspace allowed it, it may not be supported + * by the hardware and could be advertized as 'disabled'. Hence, only validate against + * the events that are advertized. + * + * Furthermore, check if the event is in fact counting if enabled, or vice-versa. + */ + for (event = 0; event < ARMV8_PMU_MAX_EVENTS - 1; event++) { + if (pmu_event_is_supported(event)) { + GUEST_ASSERT_1(test_bit(event, pmu_filter), event); + test_event_count(event, 0, true); + } else { + test_event_count(event, 0, false); + } + } +} + static void guest_code(void) { switch (guest_data.test_stage) { case TEST_STAGE_COUNTER_ACCESS: guest_counter_access_test(guest_data.expected_pmcr_n); break; + case TEST_STAGE_KVM_EVENT_FILTER: + guest_event_filter_test(guest_data.pmu_filter); + break; default: GUEST_ASSERT_1(0, guest_data.test_stage); } @@ -760,9 +909,115 @@ static void run_counter_access_tests(uint64_t pmcr_n) run_counter_access_error_test(i); } +static struct kvm_pmu_event_filter pmu_event_filters[][MAX_EVENT_FILTERS_PER_VM] = { + /* + * Each set of events denotes a filter configuration for that VM. + * During VM creation, the filters will be applied in the sequence mentioned here. + */ + { + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + }, + { + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_CPU_CYCLES), + }, + { + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_CPU_CYCLES), + EVENT_DENY(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + }, + { + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_CPU_CYCLES), + EVENT_DENY(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + EVENT_DENY(ARMV8_PMUV3_PERFCTR_CPU_CYCLES), + }, + { + EVENT_DENY(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + EVENT_DENY(ARMV8_PMUV3_PERFCTR_CPU_CYCLES), + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_CPU_CYCLES), + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + }, + { + EVENT_DENY(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_CPU_CYCLES), + EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + }, + { + EVENT_DENY(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + EVENT_DENY(ARMV8_PMUV3_PERFCTR_CPU_CYCLES), + }, + { + EVENT_DENY(ARMV8_PMUV3_PERFCTR_INST_RETIRED), + }, +}; + +static void run_kvm_event_filter_error_tests(void) +{ + int ret; + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + struct vpmu_vm *vpmu_vm; + struct kvm_vcpu_init init; + struct kvm_pmu_event_filter pmu_event_filter = EVENT_ALLOW(ARMV8_PMUV3_PERFCTR_CPU_CYCLES); + struct kvm_device_attr filter_attr = { + .group = KVM_ARM_VCPU_PMU_V3_CTRL, + .attr = KVM_ARM_VCPU_PMU_V3_FILTER, + .addr = (uint64_t) &pmu_event_filter, + }; + + /* KVM should not allow configuring filters after the PMU is initialized */ + vpmu_vm = create_vpmu_vm(guest_code, NULL); + ret = __vcpu_ioctl(vpmu_vm->vcpu, KVM_SET_DEVICE_ATTR, &filter_attr); + TEST_ASSERT(ret == -1 && errno == EBUSY, + "Failed to disallow setting an event filter after PMU init"); + destroy_vpmu_vm(vpmu_vm); + + /* Check for invalid event filter setting */ + vm = vm_create(1); + vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init); + init.features[0] |= (1 << KVM_ARM_VCPU_PMU_V3); + vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code); + + pmu_event_filter.base_event = UINT16_MAX; + pmu_event_filter.nevents = 5; + ret = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &filter_attr); + TEST_ASSERT(ret == -1 && errno == EINVAL, "Failed check for invalid filter configuration"); + kvm_vm_free(vm); +} + +static void run_kvm_event_filter_test(void) +{ + int i; + struct vpmu_vm *vpmu_vm; + struct kvm_vm *vm; + vm_vaddr_t pmu_filter_gva; + size_t pmu_filter_bmap_sz = BITS_TO_LONGS(ARMV8_PMU_MAX_EVENTS) * sizeof(unsigned long); + + guest_data.test_stage = TEST_STAGE_KVM_EVENT_FILTER; + + /* Test for valid filter configurations */ + for (i = 0; i < ARRAY_SIZE(pmu_event_filters); i++) { + vpmu_vm = create_vpmu_vm(guest_code, pmu_event_filters[i]); + vm = vpmu_vm->vm; + + pmu_filter_gva = vm_vaddr_alloc(vm, pmu_filter_bmap_sz, KVM_UTIL_MIN_VADDR); + memcpy(addr_gva2hva(vm, pmu_filter_gva), vpmu_vm->pmu_filter, pmu_filter_bmap_sz); + guest_data.pmu_filter = (unsigned long *) pmu_filter_gva; + + run_vcpu(vpmu_vm->vcpu); + + destroy_vpmu_vm(vpmu_vm); + } + + /* Check if KVM is handling the errors correctly */ + run_kvm_event_filter_error_tests(); +} + static void run_tests(uint64_t pmcr_n) { run_counter_access_tests(pmcr_n); + run_kvm_event_filter_test(); } /*