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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 5C225C4724C for ; Mon, 4 May 2020 16:57:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 32A2F206A4 for ; Mon, 4 May 2020 16:57:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Il1J6gnY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729889AbgEDQ5I (ORCPT ); Mon, 4 May 2020 12:57:08 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:57159 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729669AbgEDQ5H (ORCPT ); Mon, 4 May 2020 12:57:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588611426; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cA54hjMXQwu2Lvqq0IfxR+bA86FjlLo/DYJm0KvwWBE=; b=Il1J6gnYJXJPNlNFmIuYFatwT8uMd6xX3sqyDhrTEPs9Wpka8Y/78EoglEBkup0cMGMtNV gVPIW8uicDpx4rArlUXAyUiuH0UiUNzICG5lDoEbiRfr6SZ7Z7egn56ynfxrQYN62O5q07 l4zjD+ObpIGScEkxgTuSoJbGlb6nDnQ= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-316-ff3kMVPiOB-mnP4FWqbJCQ-1; Mon, 04 May 2020 12:57:04 -0400 X-MC-Unique: ff3kMVPiOB-mnP4FWqbJCQ-1 Received: by mail-wm1-f72.google.com with SMTP id u11so104816wmc.7 for ; Mon, 04 May 2020 09:57:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=cA54hjMXQwu2Lvqq0IfxR+bA86FjlLo/DYJm0KvwWBE=; b=PKB1ycCfl6agmqcyGaDb774ggFYXdh4grjb/0jns7VjE4wb8kV4hxay7O23ieoSiGq cY+D4TuB29BTyr1CFP4o6CBOyij5qlYIH4fEEDUuPHf8yPVetUFuEAMZL5GTM/MdyArd cq7t+m7p3/gtWCGQKuxOvt76xbmzXkLHG/vc5TXxzql7X+LYmQqRKH/i1JMAXDgWHSz3 gpriDPrOlmI10hcpamWuXrU2L3FWz6oZCv+3kxz65Jydi9SY+kR4c/I7QB+aPQlrab6D Rr+k0mzEoKi4/PSesjmC/RRiHJOyUG6iPuA7DVIw0f78u8bfsJsPo8Qd2JIqnXAVNTJQ 1MJQ== X-Gm-Message-State: AGi0PuZRLtzjGv7EeLSvczm+Eo0EQGkRkM1yhIB44n+m0K9jZIA9Zl6G kbPF8RrONHk/jdLZoScw8YgxofaA8Z8kGrtL3hphugmx9DiqFkPGl91XIOg7AfX/4oF/PKVzx+k rjp+NY8uYlFoe5sJ/eEuHFeYb X-Received: by 2002:a1c:7416:: with SMTP id p22mr16405977wmc.80.1588611422615; Mon, 04 May 2020 09:57:02 -0700 (PDT) X-Google-Smtp-Source: APiQypLfpkBvwAD0WlLP09KJEHHrrBHKkgnUHm4rVDiq9YqMhWUzzIs80/IV4XB8GGW3iWPsax4ENw== X-Received: by 2002:a1c:7416:: with SMTP id p22mr16405959wmc.80.1588611422393; Mon, 04 May 2020 09:57:02 -0700 (PDT) Received: from [192.168.178.58] ([151.20.132.175]) by smtp.gmail.com with ESMTPSA id u2sm17818146wrd.40.2020.05.04.09.57.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 04 May 2020 09:57:01 -0700 (PDT) Subject: Re: [RESEND PATCH] KVM: x86/pmu: Support full width counting To: Like Xu , Jim Mattson , Sean Christopherson Cc: Vitaly Kuznetsov , Wanpeng Li , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200427071922.86257-1-like.xu@linux.intel.com> From: Paolo Bonzini Message-ID: Date: Mon, 4 May 2020 18:57:00 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200427071922.86257-1-like.xu@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/04/20 09:19, Like Xu wrote: > + if (vmx_supported_perf_capabilities()) > + kvm_cpu_cap_check_and_set(X86_FEATURE_PDCM); I think we can always set it, worst case it will be zero. However, blocking intel_pmu_set_msr altogether is incorrect. Instead, you need to: - list the MSR in msr_based_features_all so that it appears in KVM_GET_MSR_FEATURE_INDEX_LIST - return the supported bits in vmx_get_msr_feature - allow host-initiated writes (as long as they only set supported bits) of the MSR in intel_pmu_set_msr. Thanks, Paolo