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=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 32A91C433E0 for ; Wed, 24 Mar 2021 12:24:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E11A061A0B for ; Wed, 24 Mar 2021 12:24:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232697AbhCXMYO (ORCPT ); Wed, 24 Mar 2021 08:24:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231566AbhCXMYI (ORCPT ); Wed, 24 Mar 2021 08:24:08 -0400 Received: from mail-qt1-x82b.google.com (mail-qt1-x82b.google.com [IPv6:2607:f8b0:4864:20::82b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F014C061763; Wed, 24 Mar 2021 05:24:08 -0700 (PDT) Received: by mail-qt1-x82b.google.com with SMTP id m7so17313774qtq.11; Wed, 24 Mar 2021 05:24:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=IyefHO45u1U79eOxkhQZcovymc+b6GZnAZonAFNEudY=; b=AzcC0/z9nhIrk7tsnxoiGx6Hxh4wxkyl2LZXY5sa6IuPIwog/g1PdI1vnvtyNk2SnV BHccAXRGdxDs1W4vxoWeyifTRi1eJdgUR4PfpCKwpjNi5vXOO1dnQL34fOi9ZVnKYRak HGOthOxMBa3sXkN1OrI2FN8ZA5ifdTzj+qXJfOWIQbd/W6bQdvzDxLuNxEPu2tQoV/Uz I1WzxpXe0B3sF7wUhtiCoQ8UBX2xyLOiVPfH902YJP7rBTFtpFaruvrgzxiohFaP3ZgD fgemh8hkgiXLCsPMrZ6LJr+/HT08PsVXHuNDcDErfEtmAFuV58QKlpgb6+BDNyXNLLo5 UbGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=IyefHO45u1U79eOxkhQZcovymc+b6GZnAZonAFNEudY=; b=ZyYrbJ/WcyJIX7XYshSIOjDLoCYxXMs+t6w3WfWJmSD8j4J7s0xMz2LPX5r5McY0Zn oh24/2jl6HbMIBayGpw6/ih8jgD0lVMxhR5+sv0gvvuG6YfAxVAM7/2fU4PIZxBHOmpG 4LgrqEZGHeP/sLR/GWe3fxzH4oWnPvwFD4qMEvLEU8MSeSvyXUzOEhCf+aV6h2ZnGv+Z jYcfmvhZX2ICDtH0hZmvQDntq6pfNwKK55Pr7K+AavX3Mm6h5EL3LXzzqsK4eWy+ySU2 BvJf+S6CZ6GPi540kr8yYFi0Y5d/E2SJrmOkPtN08UwUfu7btYsB28yqiPu1TAUOsrzD SlZQ== X-Gm-Message-State: AOAM531F5SWygw+GaCWxSwKAF9BYRPfzzHuCndknErgYzPGvKGfvUbrp BhXKy4Sw/Dkk6NbTAJtkVj0DYse7jAcjrt2CIziPFitjpw== X-Google-Smtp-Source: ABdhPJxxqv4PH7lOqzrXhUUrR/+RU3+KtNx7idK4wtFJIGRdxxQMRcQ3sHfZAOIRYkmdWtfykAd33CuVcTuirXpo/LQ= X-Received: by 2002:ac8:4ccc:: with SMTP id l12mr2595220qtv.137.1616588647824; Wed, 24 Mar 2021 05:24:07 -0700 (PDT) MIME-Version: 1.0 References: <20210323084515.1346540-1-vkuznets@redhat.com> In-Reply-To: <20210323084515.1346540-1-vkuznets@redhat.com> From: Haiwei Li Date: Wed, 24 Mar 2021 20:23:30 +0800 Message-ID: Subject: Re: [PATCH] KVM: x86/vPMU: Forbid writing to MSR_F15H_PERF MSRs when guest doesn't have X86_FEATURE_PERFCTR_CORE To: Vitaly Kuznetsov Cc: kvm list , Paolo Bonzini , Sean Christopherson , Wanpeng Li , Jim Mattson , Wei Huang , Joerg Roedel , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Mar 23, 2021 at 4:48 PM Vitaly Kuznetsov wrote: > > MSR_F15H_PERF_CTL0-5, MSR_F15H_PERF_CTR0-5 MSRs are only available when > X86_FEATURE_PERFCTR_CORE CPUID bit was exposed to the guest. KVM, however, > allows these MSRs unconditionally because kvm_pmu_is_valid_msr() -> > amd_msr_idx_to_pmc() check always passes and because kvm_pmu_set_msr() -> > amd_pmu_set_msr() doesn't fail. I have tested on AMD EPYC platform with perfctr_core(`cat /proc/cpuinfo | grep perfctr_core`). I started a vm without `perfctr-core`(-cpu host,-perfctr-core). Before patch : $ rdmsr 0xc0010200 0 $ wrmsr 0xc0010200 1 $ rdmsr 0xc0010200 1 After patch: # rdmsr 0xc0010200 0 # wrmsr 0xc0010200 1 wrmsr: CPU 0 cannot set MSR 0xc0010200 to 0x0000000000000001 # rdmsr 0xc0010200 0 So, Tested-by: Haiwei Li