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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham 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 C1E42C433E6 for ; Wed, 3 Mar 2021 20:56:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CF3464EFC for ; Wed, 3 Mar 2021 20:56:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1386732AbhCCSqJ (ORCPT ); Wed, 3 Mar 2021 13:46:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236768AbhCCR1W (ORCPT ); Wed, 3 Mar 2021 12:27:22 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E7EBC061763 for ; Wed, 3 Mar 2021 09:26:13 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id e9so4774863pjj.0 for ; Wed, 03 Mar 2021 09:26:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=EK8LKNqmhy5x5LGHLejHKmLyx1MsPWviMZPTqKPSEvc=; b=JAljs/qnOK5jykvYwB6CxVcKXYmcriiOHnXg+2p/0p+pr1G9jTezxPcXNnfUkuF0u6 K/gVGL85aHy4UOB9QVbFAJgBq9wGhyEJjMXDjn1Df1LlYWauOVLOuKG6nuERLGdqtrv2 2VBT4jEcYz4L1TaZTN0gkWkq9IXNMUX83aTipLspLO2xUxVy6SdyO2uxyzAIpx1W+Gjy hmoD8h3c8uNaGjUMGQPyqOxkravbrA43rCMhX8jabm4CDuqT6Pxa3Y2c9CEAONqGI8fz A0hibh7eoiujKp4rxdjoJ61sXj9OfgRvu0qgsZe2FwMJSkSBDC4DyZAVPen/txEjeohY FE8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=EK8LKNqmhy5x5LGHLejHKmLyx1MsPWviMZPTqKPSEvc=; b=j9j/ztbBS6+mhjNYeou5EfMzHUK/+L+GcblcaqQzntfTQKPoFvuKCapg0I3E0Rv4jE +bcq3ljfoy8awArUw7WjvtCwtKo3CiFYTI5Qa7pVM//Bufg5RW6G0Lc4wlxa10Wz8Wdt wuBNvLcF9zmOokiZd+UCr1exsMYlcUaFFijNdOOfBZp6K3V8/PFzsLOXPTxRf+njOjb+ rQY7ot0CQKKTuDjBJse+UD6UVVSrdsIr3VAySAZXtwIVeh4ZvV1InPN3YOLlZAXaiQLg vptTf7js/BLt2CpaiIcjxH3z20npEnHDHvhMQ7wcMuOZQ//UNNgLbvXUTjp/CLV/DN5N HinQ== X-Gm-Message-State: AOAM531+OsRa6OWyTmNrO5H37ksaBjSqkxWXWo1YqcTSqRwK2tO2+lN5 /7sG9JO2iQjRLNRtA7+hcrzswg== X-Google-Smtp-Source: ABdhPJzelju/P4Sadau5toHeUSN3iJ90+g+CrjUu7odQYNHUelH7VSCksC5Fy/t8qpf0EFPUkGkJWg== X-Received: by 2002:a17:902:f68c:b029:e5:ca30:8657 with SMTP id l12-20020a170902f68cb02900e5ca308657mr251635plg.78.1614792372514; Wed, 03 Mar 2021 09:26:12 -0800 (PST) Received: from google.com ([2620:15c:f:10:805d:6324:3372:6183]) by smtp.gmail.com with ESMTPSA id v26sm24500719pff.195.2021.03.03.09.26.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Mar 2021 09:26:11 -0800 (PST) Date: Wed, 3 Mar 2021 09:26:05 -0800 From: Sean Christopherson To: Like Xu Cc: Peter Zijlstra , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Kan Liang , Dave Hansen , wei.w.wang@intel.com, Borislav Petkov , kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 7/9] KVM: vmx/pmu: Add Arch LBR emulation and its VMCS field Message-ID: References: <20210303135756.1546253-1-like.xu@linux.intel.com> <20210303135756.1546253-8-like.xu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210303135756.1546253-8-like.xu@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 03, 2021, Like Xu wrote: > New VMX controls bits for Arch LBR are added. When bit 21 in vmentry_ctrl > is set, VM entry will write the value from the "Guest IA32_LBR_CTL" guest > state field to IA32_LBR_CTL. When bit 26 in vmexit_ctrl is set, VM exit > will clear IA32_LBR_CTL after the value has been saved to the "Guest > IA32_LBR_CTL" guest state field. ... > @@ -2529,7 +2532,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf, > VM_EXIT_LOAD_IA32_EFER | > VM_EXIT_CLEAR_BNDCFGS | > VM_EXIT_PT_CONCEAL_PIP | > - VM_EXIT_CLEAR_IA32_RTIT_CTL; > + VM_EXIT_CLEAR_IA32_RTIT_CTL | > + VM_EXIT_CLEAR_IA32_LBR_CTL; So, how does MSR_ARCH_LBR_CTL get restored on the host? What if the host wants to keep _its_ LBR recording active while the guest is running? > if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS, > &_vmexit_control) < 0) > return -EIO; > @@ -2553,7 +2557,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf, > VM_ENTRY_LOAD_IA32_EFER | > VM_ENTRY_LOAD_BNDCFGS | > VM_ENTRY_PT_CONCEAL_PIP | > - VM_ENTRY_LOAD_IA32_RTIT_CTL; > + VM_ENTRY_LOAD_IA32_RTIT_CTL | > + VM_ENTRY_LOAD_IA32_LBR_CTL; > if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_ENTRY_CTLS, > &_vmentry_control) < 0) > return -EIO; > -- > 2.29.2 >