From nobody Wed Dec 31 05:06:33 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 15EF8C4332F for ; Wed, 8 Nov 2023 00:33:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344562AbjKHAdc (ORCPT ); Tue, 7 Nov 2023 19:33:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344540AbjKHAdG (ORCPT ); Tue, 7 Nov 2023 19:33:06 -0500 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 EB2262120 for ; Tue, 7 Nov 2023 16:32:17 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-da03390793fso7188889276.3 for ; Tue, 07 Nov 2023 16:32:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1699403537; x=1700008337; 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=+33edaVs5/Z2morXGikwBPQAuHCPyAZkKikXNnwhXvI=; b=OLLDWRxOWm7R9VBzYxDgewf+btCdrzjWGL1mgBeudJ40o00xcU+CukFX96oatdRcFC CdEuuwv38a8ZtWo/crL8NEOxI0hCqDSDjzhINeLh191LSswfSCoPmkcPThBq67IRnLAs NLORaPAT/TsozT/Kw3Sp3URaBI+tSepoRlg5q35GiYYqRZDJI643BikBc8eKPuIYqEDe buI5BWUnuE6izt+VBhcXdHPqf46A0HwneT3HDdgIYg7n/J4FstFQxnQ71viY6lSKaTMm Cbf+kKfyFNO2fnaOL4uIdXX1ooEd5yjKubbMZYZgVdp0FKP4kAY8IuFkCXydzd+Pm+K7 LT9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699403537; x=1700008337; 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=+33edaVs5/Z2morXGikwBPQAuHCPyAZkKikXNnwhXvI=; b=CIF5OK+9gnbD3klNjrnt+oNLWvRAKwd+d9A4x4WSOvI2Dw9KQ3UW56skUhrT66ff7D ll4dVwb+MgGJieuYZvmK6QMXLkJYz/p9EllyA9thzJu7ir6myHvojroN36Wb8d/RWk90 NN7vbNEPwn9gLtXVt5+4r9EvAkjL3OaGZJDblFSDDIBCt4QFRpro8pvB1v62ftmy93bc M/zXwcouY7t7mkubfjEeV/bVhzBVW/YtqvE+EowHkuxOauR6qED6NJnyvDR4i4eKOyt2 5ItAEfyLsJ7B/ZvQjZQalI8rhke2kZ/p/wvy6TR/twfBdo9aGixWMkyvAv6XDWeJSyys R3+g== X-Gm-Message-State: AOJu0YzONNsQWXf8zKq65Wau+iUI+mAYmfGM+zpseoUfCvezhDMcQO/N KxuX4m3Ef64Yr8yekg3YvYSGiRbMHv4= X-Google-Smtp-Source: AGHT+IH2IqLaGw4XGC8tn18p+rgc4o7UnI0rnRhAbbNKz9ppW72ZiipJU4pSELozCz1UqmXEDYzcKM0zRfQ= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:1fd6:0:b0:d9a:e3d9:99bd with SMTP id f205-20020a251fd6000000b00d9ae3d999bdmr5762ybf.5.1699403537213; Tue, 07 Nov 2023 16:32:17 -0800 (PST) Reply-To: Sean Christopherson Date: Tue, 7 Nov 2023 16:31:35 -0800 In-Reply-To: <20231108003135.546002-1-seanjc@google.com> Mime-Version: 1.0 References: <20231108003135.546002-1-seanjc@google.com> X-Mailer: git-send-email 2.42.0.869.gea05f2083d-goog Message-ID: <20231108003135.546002-20-seanjc@google.com> Subject: [PATCH v7 19/19] 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 , Jim Mattson , Jinrong Liang , Aaron Lewis , Like Xu 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 Reviewed-by: Dapeng Mi --- .../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 d775cc7e8fab..09332b3c0a69 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 \ @@ -545,6 +560,7 @@ 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