From nobody Wed Dec 31 12:30:28 2025 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 634E4C4167B for ; Sat, 4 Nov 2023 00:04:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230525AbjKDAES (ORCPT ); Fri, 3 Nov 2023 20:04:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231765AbjKDADl (ORCPT ); Fri, 3 Nov 2023 20:03:41 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 074A91736 for ; Fri, 3 Nov 2023 17:03:19 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-da39d244087so3392665276.3 for ; Fri, 03 Nov 2023 17:03:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1699056199; x=1699660999; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=yilGYXp68Gbkah/X+aiEqo69eD6DcRs1k7jq3pnaJG0=; b=PrhYXGRQXDy2Ufld/nmOej2eX0/rRRKB0FLcxie6dNxN4DNLBqb756aOgohALGvpgn NDo95V+7d7ZtI9iT5SWw32bMVk22ylN1S3QKup6zovh8lXgBAvuP8NZtAfKi0gXJNjrt u//eorY5smk8dIHKZU3wzVTVcnqh1k1ZJlbequh/iFH40LW1rC4nGUeaKyrSKbyHKQXH Jh6JfDF/oIHs9kaTMz3TC+7MN+cyKlebh6AYsmUsLvtRgkS9+7qmotRNJR8ysk7zCDZd Ja8TjC6YEeyoI3avxBoPNLk7PAcGmaLJ8DOzxqt9Oue9KcbJ0Mmf2aiQ6uYe/EPk4XU9 DRIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699056199; x=1699660999; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=yilGYXp68Gbkah/X+aiEqo69eD6DcRs1k7jq3pnaJG0=; b=nyZnLvhnPz6X0R7QtiPd2pmVwtAHm+1QzWvN9x4DP0cpwq8kfLceL8E0xBse/bfBcK b9huJJGr9FPjFiaV8Ti8qeY2BfSezhk4E011mMj3+uXlLmN6OxilQAY9MDykT3WQR0Ko kfC7OIuGmfKewqV2U39R6yc5F5mskloroVVChAmIoigBa6rPYzGoW9GUiXwQQdv0QjY1 cG3Fe3Rtfj9TPYr7THrSBpWAkH3kGQ5xTmgSdKMpIADybX6mrQNV3hI7bjaa3JisucTT mICOX24a9eERVNSw2U/anJc2nWLcc8cKxYyX0cYr9rSTtYcQRblbTPIyTLZ2ShDCXYLU jxaw== X-Gm-Message-State: AOJu0Yz/NjVxq2PRyHLZRNv5Hq+Y0sOE+M2zAZqr+9FpWttHlNzd5/nN dnU4uYSjnJ/+Pn+s6uPguqD86l/+ETw= X-Google-Smtp-Source: AGHT+IEicFfkBpZ2m9QbCFIL/o0Vua2YTrgtnpUv+V0BpPEsG8P69HWK7wUOZjk1sFEN97lq90Ji7Khz4nM= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6902:565:b0:da0:c979:fd70 with SMTP id a5-20020a056902056500b00da0c979fd70mr474880ybt.9.1699056199021; Fri, 03 Nov 2023 17:03:19 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 3 Nov 2023 17:02:38 -0700 In-Reply-To: <20231104000239.367005-1-seanjc@google.com> Mime-Version: 1.0 References: <20231104000239.367005-1-seanjc@google.com> X-Mailer: git-send-email 2.42.0.869.gea05f2083d-goog Message-ID: <20231104000239.367005-21-seanjc@google.com> Subject: [PATCH v6 20/20] KVM: selftests: Test PMC virtualization with forced emulation From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Kan Liang , Dapeng Mi , Jinrong Liang , Like Xu , Jim Mattson , Aaron Lewis Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Extend the PMC counters test to use forced emulation to verify that KVM emulates counter events for instructions retired and branches retired. Force emulation for only a subset of the measured code to test that KVM does the right thing when mixing perf events with emulated events. Signed-off-by: Sean Christopherson --- .../selftests/kvm/x86_64/pmu_counters_test.c | 44 +++++++++++++------ 1 file changed, 30 insertions(+), 14 deletions(-) diff --git a/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c b/tools= /testing/selftests/kvm/x86_64/pmu_counters_test.c index e6cf76d3499b..c66cf92cc9cc 100644 --- a/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c +++ b/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c @@ -21,6 +21,7 @@ =20 static uint8_t kvm_pmu_version; static bool kvm_has_perf_caps; +static bool is_forced_emulation_enabled; =20 static struct kvm_vm *pmu_vm_create_with_one_vcpu(struct kvm_vcpu **vcpu, void *guest_code, @@ -34,6 +35,7 @@ static struct kvm_vm *pmu_vm_create_with_one_vcpu(struct = kvm_vcpu **vcpu, vcpu_init_descriptor_tables(*vcpu); =20 sync_global_to_guest(vm, kvm_pmu_version); + sync_global_to_guest(vm, is_forced_emulation_enabled); =20 /* * Set PERF_CAPABILITIES before PMU version as KVM disallows enabling @@ -138,37 +140,50 @@ static void guest_assert_event_count(uint8_t idx, * If CLFUSH{,OPT} is supported, flush the cacheline containing (at least)= the * start of the loop to force LLC references and misses, i.e. to allow tes= ting * that those events actually count. + * + * If forced emulation is enabled (and specified), force emulation on a su= bset + * of the measured code to verify that KVM correctly emulates instructions= and + * branches retired events in conjunction with hardware also counting said + * events. */ -#define GUEST_MEASURE_EVENT(_msr, _value, clflush) \ +#define GUEST_MEASURE_EVENT(_msr, _value, clflush, FEP) \ do { \ __asm__ __volatile__("wrmsr\n\t" \ clflush "\n\t" \ "mfence\n\t" \ "1: mov $" __stringify(NUM_BRANCHES) ", %%ecx\n\t" \ - "loop .\n\t" \ - "mov %%edi, %%ecx\n\t" \ - "xor %%eax, %%eax\n\t" \ - "xor %%edx, %%edx\n\t" \ + FEP "loop .\n\t" \ + FEP "mov %%edi, %%ecx\n\t" \ + FEP "xor %%eax, %%eax\n\t" \ + FEP "xor %%edx, %%edx\n\t" \ "wrmsr\n\t" \ :: "a"((uint32_t)_value), "d"(_value >> 32), \ "c"(_msr), "D"(_msr) \ ); \ } while (0) =20 +#define GUEST_TEST_EVENT(_idx, _event, _pmc, _pmc_msr, _ctrl_msr, _value, = FEP) \ +do { \ + wrmsr(pmc_msr, 0); \ + \ + if (this_cpu_has(X86_FEATURE_CLFLUSHOPT)) \ + GUEST_MEASURE_EVENT(_ctrl_msr, _value, "clflushopt 1f", FEP); \ + else if (this_cpu_has(X86_FEATURE_CLFLUSH)) \ + GUEST_MEASURE_EVENT(_ctrl_msr, _value, "clflush 1f", FEP); \ + else \ + GUEST_MEASURE_EVENT(_ctrl_msr, _value, "nop", FEP); \ + \ + guest_assert_event_count(_idx, _event, _pmc, _pmc_msr); \ +} while (0) + static void __guest_test_arch_event(uint8_t idx, struct kvm_x86_pmu_featur= e event, uint32_t pmc, uint32_t pmc_msr, uint32_t ctrl_msr, uint64_t ctrl_msr_value) { - wrmsr(pmc_msr, 0); + GUEST_TEST_EVENT(idx, event, pmc, pmc_msr, ctrl_msr, ctrl_msr_value, ""); =20 - if (this_cpu_has(X86_FEATURE_CLFLUSHOPT)) - GUEST_MEASURE_EVENT(ctrl_msr, ctrl_msr_value, "clflushopt 1f"); - else if (this_cpu_has(X86_FEATURE_CLFLUSH)) - GUEST_MEASURE_EVENT(ctrl_msr, ctrl_msr_value, "clflush 1f"); - else - GUEST_MEASURE_EVENT(ctrl_msr, ctrl_msr_value, "nop"); - - guest_assert_event_count(idx, event, pmc, pmc_msr); + if (is_forced_emulation_enabled) + GUEST_TEST_EVENT(idx, event, pmc, pmc_msr, ctrl_msr, ctrl_msr_value, KVM= _FEP); } =20 #define X86_PMU_FEATURE_NULL \ @@ -544,6 +559,7 @@ int main(int argc, char *argv[]) =20 kvm_pmu_version =3D kvm_cpu_property(X86_PROPERTY_PMU_VERSION); kvm_has_perf_caps =3D kvm_cpu_has(X86_FEATURE_PDCM); + is_forced_emulation_enabled =3D kvm_is_forced_emulation_enabled(); =20 test_intel_counters(); =20 --=20 2.42.0.869.gea05f2083d-goog