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=-23.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 9E811C4167B for ; Mon, 7 Dec 2020 23:23:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 749BF23A23 for ; Mon, 7 Dec 2020 23:23:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727975AbgLGXW7 (ORCPT ); Mon, 7 Dec 2020 18:22:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726196AbgLGXW7 (ORCPT ); Mon, 7 Dec 2020 18:22:59 -0500 Received: from mail-ot1-x341.google.com (mail-ot1-x341.google.com [IPv6:2607:f8b0:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34510C061793 for ; Mon, 7 Dec 2020 15:22:13 -0800 (PST) Received: by mail-ot1-x341.google.com with SMTP id h18so10242669otq.12 for ; Mon, 07 Dec 2020 15:22:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ecLFgA6ZVCXrlWighsImjDrXnRjbX/ebIaxkalo6/1w=; b=m9uza9hGO/gEO45Mlbe5J+I8EvvJeJHIkmRVRSp5NbFk4RQSlSp828okY3HqNFwRmC lg6oDYOANzhyajOmaeldvAnga3DuDtJf72t/6jMyIERuC0EYCg8QpUGyahruhT7Eebn5 uE1Uj1QZ+pH7wjFxnjU69zipvFLf+HflQkjR/PKvWLN33evvvHJ/vCCxzmD+Y77OipEb A1Uhzily9tuqOO3xODNqNWkiUSO41F/P6jx+hXJeavMGrPBJeJod9kgVEuUv3rsRrP1Y wHCG+XFGYgqDZO0zLbMuJkvx2DI2QisX3UvkfvrKiqwKu2FyPFb/OIs4nwYF8gRZXlGm AtBQ== 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=ecLFgA6ZVCXrlWighsImjDrXnRjbX/ebIaxkalo6/1w=; b=QTyjck2JrBw4QmOJM+FoWTPn6GKbbxCNa/9NYzIkRuHb1flNkb6xEzsdjX/NlIGEGc vrYsXwG1TDLdUP0cvowSlcJa1madYIV36Xyi3/4E36rPFTQ3NR0n3DUA3qc3Hv2C9x3b wInZKLExNVHZRUNF8+L4zLqsZF2nqttEbi7OeQMF3XBjQ8RD2Y1MPFYjd9SflqoGPYY+ O+TIGy2lS3/SQmW7bYSsgn7Ophao2Wqd/Xo7penMTG3mQ7n4UPc/l9TNfP8+bHvGFLq2 ocNUFZw8dYBt2M3zPUgf4LpZbgjBU+fyAENy4IwmHvoGAC+rIMiK7EVt2RI+0poDgOqk l3zw== X-Gm-Message-State: AOAM530Bi1CsFkow41FgpP/6bgqFuV1NMzGd30K2elE1d1G1m5ESOjWk 4E1VSlJn+BRpVxZwzGncZv1xVgJk6j582DdIbCCKOA== X-Google-Smtp-Source: ABdhPJx72Bm1nE0g6cD2iqMrP2OAG4RUggDRs+kLGI/Mzm3KLvKIiWvl0+zmUu779zCvhLp7KCnx2Hj9ArckxZjwkJM= X-Received: by 2002:a9d:d01:: with SMTP id 1mr14480096oti.295.1607383332277; Mon, 07 Dec 2020 15:22:12 -0800 (PST) MIME-Version: 1.0 References: <160738054169.28590.5171339079028237631.stgit@bmoger-ubuntu> <160738067105.28590.10158084163761735153.stgit@bmoger-ubuntu> In-Reply-To: <160738067105.28590.10158084163761735153.stgit@bmoger-ubuntu> From: Jim Mattson Date: Mon, 7 Dec 2020 15:22:00 -0800 Message-ID: Subject: Re: [PATCH 1/2] x86/cpufeatures: Add the Virtual SPEC_CTRL feature To: Babu Moger Cc: Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "Yu, Fenghua" , Tony Luck , Wanpeng Li , kvm list , Tom Lendacky , Peter Zijlstra , Sean Christopherson , Joerg Roedel , "the arch/x86 maintainers" , kyung.min.park@intel.com, LKML , Krish Sadhukhan , "H . Peter Anvin" , mgross@linux.intel.com, Vitaly Kuznetsov , kim.phillips@amd.com, wei.huang2@amd.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 7, 2020 at 2:38 PM Babu Moger wrote: > > Newer AMD processors have a feature to virtualize the use of the SPEC_CTRL > MSR. This feature is identified via CPUID 0x8000000A_EDX[20]. When present, > the SPEC_CTRL MSR is automatically virtualized and no longer requires > hypervisor intervention. > > Signed-off-by: Babu Moger > --- > arch/x86/include/asm/cpufeatures.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h > index dad350d42ecf..d649ac5ed7c7 100644 > --- a/arch/x86/include/asm/cpufeatures.h > +++ b/arch/x86/include/asm/cpufeatures.h > @@ -335,6 +335,7 @@ > #define X86_FEATURE_AVIC (15*32+13) /* Virtual Interrupt Controller */ > #define X86_FEATURE_V_VMSAVE_VMLOAD (15*32+15) /* Virtual VMSAVE VMLOAD */ > #define X86_FEATURE_VGIF (15*32+16) /* Virtual GIF */ > +#define X86_FEATURE_V_SPEC_CTRL (15*32+20) /* Virtual SPEC_CTRL */ Shouldn't this bit be reported by KVM_GET_SUPPORTED_CPUID when it's enumerated on the host? > /* Intel-defined CPU features, CPUID level 0x00000007:0 (ECX), word 16 */ > #define X86_FEATURE_AVX512VBMI (16*32+ 1) /* AVX512 Vector Bit Manipulation instructions*/ >