From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E7E1C4363A for ; Fri, 30 Oct 2020 03:57:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 281312068E for ; Fri, 30 Oct 2020 03:57:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726365AbgJ3D46 (ORCPT ); Thu, 29 Oct 2020 23:56:58 -0400 Received: from mga09.intel.com ([134.134.136.24]:4254 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726510AbgJ3D45 (ORCPT ); Thu, 29 Oct 2020 23:56:57 -0400 IronPort-SDR: V6C64PRa/kHFFRYdpwkMwIbVnd+QBMHKI6TPLL53IP40EcOrOvYHOdRBEaSPin11eUc9AEevEq GPcQ8khAs/QA== X-IronPort-AV: E=McAfee;i="6000,8403,9789"; a="168685748" X-IronPort-AV: E=Sophos;i="5.77,432,1596524400"; d="scan'208";a="168685748" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Oct 2020 20:56:56 -0700 IronPort-SDR: FgOetFluXbyOFh4FUi4MoRUghkSwXD86YQvNsrPaVPs18W/FKMh22rOMc9T/mWTXZT3L5fYxkJ bOjh7PDqZgcg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,432,1596524400"; d="scan'208";a="525770454" Received: from sqa-gate.sh.intel.com (HELO clx-ap-likexu.tsp.org) ([10.239.48.212]) by fmsmga006.fm.intel.com with ESMTP; 29 Oct 2020 20:56:54 -0700 From: Like Xu To: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RESEND v13 07/10] KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation Date: Fri, 30 Oct 2020 11:52:17 +0800 Message-Id: <20201030035220.102403-8-like.xu@linux.intel.com> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20201030035220.102403-1-like.xu@linux.intel.com> References: <20201030035220.102403-1-like.xu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org When the LBR records msrs has already been pass-through, there is no need to call vmx_update_intercept_for_lbr_msrs() again and again, and vice versa. Signed-off-by: Like Xu --- arch/x86/kvm/vmx/pmu_intel.c | 13 +++++++++++++ arch/x86/kvm/vmx/vmx.h | 3 +++ 2 files changed, 16 insertions(+) diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 6b3319dbfa72..72a6dd6ca0ac 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -562,6 +562,7 @@ static void intel_pmu_init(struct kvm_vcpu *vcpu) vmx_get_perf_capabilities() : 0; lbr_desc->records.nr = 0; lbr_desc->event = NULL; + lbr_desc->already_passthrough = false; } static void intel_pmu_reset(struct kvm_vcpu *vcpu) @@ -607,12 +608,24 @@ static void vmx_update_intercept_for_lbr_msrs(struct kvm_vcpu *vcpu, bool set) static inline void vmx_disable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) { + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (!lbr_desc->already_passthrough) + return; + vmx_update_intercept_for_lbr_msrs(vcpu, true); + lbr_desc->already_passthrough = false; } static inline void vmx_enable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) { + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (lbr_desc->already_passthrough) + return; + vmx_update_intercept_for_lbr_msrs(vcpu, false); + lbr_desc->already_passthrough = true; } /* diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 2bd866c5a4e4..1869f5090e40 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -90,6 +90,9 @@ struct lbr_desc { * The records may be inaccurate if the host reclaims the LBR. */ struct perf_event *event; + + /* A flag to reduce the overhead of LBR pass-through or cancellation. */ + bool already_passthrough; }; /* -- 2.21.3