From patchwork Mon Feb 13 18:02:29 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: 13138766 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 D121BC636CC for ; Mon, 13 Feb 2023 18:03:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231252AbjBMSDT (ORCPT ); Mon, 13 Feb 2023 13:03:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231145AbjBMSC7 (ORCPT ); Mon, 13 Feb 2023 13:02:59 -0500 Received: from mail-il1-x149.google.com (mail-il1-x149.google.com [IPv6:2607:f8b0:4864:20::149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F4C71A8 for ; Mon, 13 Feb 2023 10:02:48 -0800 (PST) Received: by mail-il1-x149.google.com with SMTP id i23-20020a056e021d1700b003111192e89aso9797190ila.10 for ; Mon, 13 Feb 2023 10:02:48 -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=NBYdz/0TDvO7IvfPjxUDSlCbo4CB4F+r8/XPr+qUWDQ=; b=q/9pkLp04O+q0/h8HqWtbW0b4VJCwyM93nDv77GqvjJ6CZ4Czxpm5H8d/lDlpTXsCj Lxw6nGE3jZxgA/Lo2HUBZdf5EE0qjSxvUgHGZW6o0+9e+HkhvQpiHgZdToFd+AbKHIFB A5CHSl5TSlCOZjqQlpxD5e5wkvR8X/0b6YcT5jL/nTql/+HqHR7svK3rwtTT1Y+ZTR7R GJ/moeEEW6KXP6NWUNqTjcT4/YBd1FC1rP0DUY32WTXTIIVoTMVTv09vwSp4CKIUlMXE jaIuuptu376OmVIHLWwwSlFCwuNah5pfd60Cn7DxqT17NURWdErBO2ZYOWNiy3gYm9fN UGog== 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=NBYdz/0TDvO7IvfPjxUDSlCbo4CB4F+r8/XPr+qUWDQ=; b=cBnJoqr99kC/gtWG0Eb/govvF4RO8Pto33hxLYVoGhcrd1OWGj7SA8SxtUhiRatJ3P p+cvVFP1bfjMxnaRbqxJMsl9lHms8SJpIXKQmVvy+bHmZMuXJvBEEmvcwDpFcPsBhpVD EmXsogRCUu5+uYHxRdr/o4DhH+aJhhZWmlJVJm3INYGM5cd50eBmKC9zq7dsDqPPMbGt wVJ/i1LX7WZltbVnqHBqibC655BO86MFF6EtowaWPIekv/Pnufr6y7oz44D20ffA5+VB 3rQ5wRge9fPTNbl2DDVsgTWmS63A7/HMC4DMz/SyE1cHepEUB28lpwD8j72gbCBulytT ULRA== X-Gm-Message-State: AO0yUKWMwtI5kLfA24inlpxqGoiOkNGX4IpOlvWuqYpMs0vLdnoQcJDy P+dhub7OPhQTIYf25ItkPJUFZlIhjgUD X-Google-Smtp-Source: AK7set/5XtGkWzBFYSheugf2dkdONWpj2qzeqEPgWjWfAnOy0vxdZ74FjxG8HtTLpC55TP3sfOr6vpeLRU29 X-Received: from rananta-linux.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:22b5]) (user=rananta job=sendgmr) by 2002:a92:9407:0:b0:313:f870:58fb with SMTP id c7-20020a929407000000b00313f87058fbmr2508047ili.2.1676311368215; Mon, 13 Feb 2023 10:02:48 -0800 (PST) Date: Mon, 13 Feb 2023 18:02:29 +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: <20230213180234.2885032-9-rananta@google.com> Subject: [PATCH 08/13] selftests: KVM: aarch64: Add vCPU migration test for PMU 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 Implement a stress test for KVM by frequently force-migrating the vCPU to random pCPUs in the system. This would validate the save/restore functionality of KVM and starting/stopping of PMU counters as necessary. Signed-off-by: Raghavendra Rao Ananta --- .../testing/selftests/kvm/aarch64/vpmu_test.c | 195 +++++++++++++++++- 1 file changed, 193 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kvm/aarch64/vpmu_test.c b/tools/testing/selftests/kvm/aarch64/vpmu_test.c index 5c166df245589..0c9d801f4e602 100644 --- a/tools/testing/selftests/kvm/aarch64/vpmu_test.c +++ b/tools/testing/selftests/kvm/aarch64/vpmu_test.c @@ -19,9 +19,15 @@ * higher exception levels (EL2, EL3). Verify this functionality by * configuring and trying to count the events for EL2 in the guest. * + * 4. Since the PMU registers are per-cpu, stress KVM by frequently + * migrating the guest vCPU to random pCPUs in the system, and check + * if the vPMU is still behaving as expected. + * * Copyright (c) 2022 Google LLC. * */ +#define _GNU_SOURCE + #include #include #include @@ -30,6 +36,11 @@ #include #include #include +#include +#include +#include + +#include "delay.h" /* The max number of the PMU event counters (excluding the cycle counter) */ #define ARMV8_PMU_MAX_GENERAL_COUNTERS (ARMV8_PMU_MAX_COUNTERS - 1) @@ -37,6 +48,8 @@ /* The max number of event numbers that's supported */ #define ARMV8_PMU_MAX_EVENTS 64 +#define msecs_to_usecs(msec) ((msec) * 1000LL) + /* * The macros and functions below for reading/writing PMEV{CNTR,TYPER}_EL0 * were basically copied from arch/arm64/kernel/perf_event.c. @@ -265,6 +278,7 @@ enum test_stage { TEST_STAGE_COUNTER_ACCESS = 1, TEST_STAGE_KVM_EVENT_FILTER, TEST_STAGE_KVM_EVTYPE_FILTER, + TEST_STAGE_VCPU_MIGRATION, }; struct guest_data { @@ -275,6 +289,19 @@ struct guest_data { static struct guest_data guest_data; +#define VCPU_MIGRATIONS_TEST_ITERS_DEF 1000 +#define VCPU_MIGRATIONS_TEST_MIGRATION_FREQ_MS 2 + +struct test_args { + int vcpu_migration_test_iter; + int vcpu_migration_test_migrate_freq_ms; +}; + +static struct test_args test_args = { + .vcpu_migration_test_iter = VCPU_MIGRATIONS_TEST_ITERS_DEF, + .vcpu_migration_test_migrate_freq_ms = VCPU_MIGRATIONS_TEST_MIGRATION_FREQ_MS, +}; + static void guest_sync_handler(struct ex_regs *regs) { uint64_t esr, ec; @@ -352,7 +379,6 @@ 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 @@ -459,6 +485,13 @@ static void test_event_count(uint64_t event, int pmc_idx, bool expect_count) } } +static void test_basic_pmu_functionality(void) +{ + /* Test events on generic and cycle counters */ + test_instructions_count(0, true); + test_cycles_count(true); +} + /* * Check if @mask bits in {PMCNTEN,PMINTEN,PMOVS}{SET,CLR} registers * are set or cleared as specified in @set_expected. @@ -748,6 +781,16 @@ static void guest_evtype_filter_test(void) GUEST_ASSERT_2(cnt == 0, cnt, typer); } +static void guest_vcpu_migration_test(void) +{ + /* + * While the userspace continuously migrates this vCPU to random pCPUs, + * run basic PMU functionalities and verify the results. + */ + while (test_args.vcpu_migration_test_iter--) + test_basic_pmu_functionality(); +} + static void guest_code(void) { switch (guest_data.test_stage) { @@ -760,6 +803,9 @@ static void guest_code(void) case TEST_STAGE_KVM_EVTYPE_FILTER: guest_evtype_filter_test(); break; + case TEST_STAGE_VCPU_MIGRATION: + guest_vcpu_migration_test(); + break; default: GUEST_ASSERT_1(0, guest_data.test_stage); } @@ -837,6 +883,7 @@ create_vpmu_vm(void *guest_code, struct kvm_pmu_event_filter *pmu_event_filters) vpmu_vm->vm = vm = vm_create(1); vm_init_descriptor_tables(vm); + /* Catch exceptions for easier debugging */ for (ec = 0; ec < ESR_EC_NUM; ec++) { vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, ec, @@ -881,6 +928,8 @@ static void run_vcpu(struct kvm_vcpu *vcpu) struct ucall uc; sync_global_to_guest(vcpu->vm, guest_data); + sync_global_to_guest(vcpu->vm, test_args); + vcpu_run(vcpu); switch (get_ucall(vcpu, &uc)) { case UCALL_ABORT: @@ -1098,11 +1147,112 @@ static void run_kvm_evtype_filter_test(void) destroy_vpmu_vm(vpmu_vm); } +struct vcpu_migrate_data { + struct vpmu_vm *vpmu_vm; + pthread_t *pt_vcpu; + bool vcpu_done; +}; + +static void *run_vcpus_migrate_test_func(void *arg) +{ + struct vcpu_migrate_data *migrate_data = arg; + struct vpmu_vm *vpmu_vm = migrate_data->vpmu_vm; + + run_vcpu(vpmu_vm->vcpu); + migrate_data->vcpu_done = true; + + return NULL; +} + +static uint32_t get_pcpu(void) +{ + uint32_t pcpu; + unsigned int nproc_conf; + cpu_set_t online_cpuset; + + nproc_conf = get_nprocs_conf(); + sched_getaffinity(0, sizeof(cpu_set_t), &online_cpuset); + + /* Randomly find an available pCPU to place the vCPU on */ + do { + pcpu = rand() % nproc_conf; + } while (!CPU_ISSET(pcpu, &online_cpuset)); + + return pcpu; +} + +static int migrate_vcpu(struct vcpu_migrate_data *migrate_data) +{ + int ret; + cpu_set_t cpuset; + uint32_t new_pcpu = get_pcpu(); + + CPU_ZERO(&cpuset); + CPU_SET(new_pcpu, &cpuset); + + pr_debug("Migrating vCPU to pCPU: %u\n", new_pcpu); + + ret = pthread_setaffinity_np(*migrate_data->pt_vcpu, sizeof(cpuset), &cpuset); + + /* Allow the error where the vCPU thread is already finished */ + TEST_ASSERT(ret == 0 || ret == ESRCH, + "Failed to migrate the vCPU to pCPU: %u; ret: %d\n", new_pcpu, ret); + + return ret; +} + +static void *vcpus_migrate_func(void *arg) +{ + struct vcpu_migrate_data *migrate_data = arg; + + while (!migrate_data->vcpu_done) { + usleep(msecs_to_usecs(test_args.vcpu_migration_test_migrate_freq_ms)); + migrate_vcpu(migrate_data); + } + + return NULL; +} + +static void run_vcpu_migration_test(uint64_t pmcr_n) +{ + int ret; + struct vpmu_vm *vpmu_vm; + pthread_t pt_vcpu, pt_sched; + struct vcpu_migrate_data migrate_data = { + .pt_vcpu = &pt_vcpu, + .vcpu_done = false, + }; + + __TEST_REQUIRE(get_nprocs() >= 2, "At least two pCPUs needed for vCPU migration test"); + + guest_data.test_stage = TEST_STAGE_VCPU_MIGRATION; + guest_data.expected_pmcr_n = pmcr_n; + + migrate_data.vpmu_vm = vpmu_vm = create_vpmu_vm(guest_code, NULL); + + /* Initialize random number generation for migrating vCPUs to random pCPUs */ + srand(time(NULL)); + + /* Spawn a vCPU thread */ + ret = pthread_create(&pt_vcpu, NULL, run_vcpus_migrate_test_func, &migrate_data); + TEST_ASSERT(!ret, "Failed to create the vCPU thread"); + + /* Spawn a scheduler thread to force-migrate vCPUs to various pCPUs */ + ret = pthread_create(&pt_sched, NULL, vcpus_migrate_func, &migrate_data); + TEST_ASSERT(!ret, "Failed to create the scheduler thread for migrating the vCPUs"); + + pthread_join(pt_sched, NULL); + pthread_join(pt_vcpu, NULL); + + destroy_vpmu_vm(vpmu_vm); +} + static void run_tests(uint64_t pmcr_n) { run_counter_access_tests(pmcr_n); run_kvm_event_filter_test(); run_kvm_evtype_filter_test(); + run_vcpu_migration_test(pmcr_n); } /* @@ -1121,12 +1271,53 @@ static uint64_t get_pmcr_n_limit(void) return FIELD_GET(ARMV8_PMU_PMCR_N, pmcr); } -int main(void) +static void print_help(char *name) +{ + pr_info("Usage: %s [-h] [-i vcpu_migration_test_iterations] [-m vcpu_migration_freq_ms]\n", + name); + pr_info("\t-i: Number of iterations of vCPU migrations test (default: %u)\n", + VCPU_MIGRATIONS_TEST_ITERS_DEF); + pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. (default: %u)\n", + VCPU_MIGRATIONS_TEST_MIGRATION_FREQ_MS); + pr_info("\t-h: print this help screen\n"); +} + +static bool parse_args(int argc, char *argv[]) +{ + int opt; + + while ((opt = getopt(argc, argv, "hi:m:")) != -1) { + switch (opt) { + case 'i': + test_args.vcpu_migration_test_iter = + atoi_positive("Nr vCPU migration iterations", optarg); + break; + case 'm': + test_args.vcpu_migration_test_migrate_freq_ms = + atoi_positive("vCPU migration frequency", optarg); + break; + case 'h': + default: + goto err; + } + } + + return true; + +err: + print_help(argv[0]); + return false; +} + +int main(int argc, char *argv[]) { uint64_t pmcr_n; TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_PMU_V3)); + if (!parse_args(argc, argv)) + exit(KSFT_SKIP); + pmcr_n = get_pmcr_n_limit(); run_tests(pmcr_n);