From nobody Sun Dec 14 06:16:08 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 9E4FFC00140 for ; Mon, 15 Aug 2022 20:03:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242545AbiHOUDF (ORCPT ); Mon, 15 Aug 2022 16:03:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345765AbiHOT7z (ORCPT ); Mon, 15 Aug 2022 15:59:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C03B379A5C; Mon, 15 Aug 2022 11:53:13 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 338836122A; Mon, 15 Aug 2022 18:53:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F84AC433C1; Mon, 15 Aug 2022 18:53:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660589591; bh=9RVo2cv9gTDUf/SygOdjGWEFi20yyH/rO62XiMle2Yg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mjra04/jiIL0YyyhWSGe/ef/oa3xAV0wLl3IkcxzHbZmtDxGSV6OUbTwMPQ0lgvXh ZlYzzt1rH+k5Jy1vnWOBjXOoiGt+gpAJN6lXLzcT+/X1PVONdo6cTzmC49WNbg9N4R TuPW39ZBkSALzuS3kWBLrOJVOMKUKtUMGjrqVLJo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Christopherson , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.15 735/779] KVM: VMX: Add helper to check if the guest PMU has PERF_GLOBAL_CTRL Date: Mon, 15 Aug 2022 20:06:19 +0200 Message-Id: <20220815180408.866071215@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Sean Christopherson [ Upstream commit b663f0b5f3d665c261256d1f76e98f077c6e56af ] Add a helper to check of the guest PMU has PERF_GLOBAL_CTRL, which is unintuitive _and_ diverges from Intel's architecturally defined behavior. Even worse, KVM currently implements the check using two different (but equivalent) checks, _and_ there has been at least one attempt to add a _third_ flavor. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Message-Id: <20220722224409.1336532-4-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/vmx/pmu_intel.c | 4 ++-- arch/x86/kvm/vmx/vmx.h | 12 ++++++++++++ 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index f9054e7ec89e..e624a39365ec 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -104,7 +104,7 @@ static bool intel_pmc_is_enabled(struct kvm_pmc *pmc) { struct kvm_pmu *pmu =3D pmc_to_pmu(pmc); =20 - if (pmu->version < 2) + if (!intel_pmu_has_perf_global_ctrl(pmu)) return true; =20 return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl); @@ -222,7 +222,7 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u= 32 msr) case MSR_CORE_PERF_GLOBAL_STATUS: case MSR_CORE_PERF_GLOBAL_CTRL: case MSR_CORE_PERF_GLOBAL_OVF_CTRL: - ret =3D pmu->version > 1; + return intel_pmu_has_perf_global_ctrl(pmu); break; default: ret =3D get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) || diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index a8b8150252bb..20f1213a9368 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -92,6 +92,18 @@ union vmx_exit_reason { u32 full; }; =20 +static inline bool intel_pmu_has_perf_global_ctrl(struct kvm_pmu *pmu) +{ + /* + * Architecturally, Intel's SDM states that IA32_PERF_GLOBAL_CTRL is + * supported if "CPUID.0AH: EAX[7:0] > 0", i.e. if the PMU version is + * greater than zero. However, KVM only exposes and emulates the MSR + * to/for the guest if the guest PMU supports at least "Architectural + * Performance Monitoring Version 2". + */ + return pmu->version > 1; +} + #define vcpu_to_lbr_desc(vcpu) (&to_vmx(vcpu)->lbr_desc) #define vcpu_to_lbr_records(vcpu) (&to_vmx(vcpu)->lbr_desc.records) =20 --=20 2.35.1