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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 34B47C31E4B for ; Fri, 14 Jun 2019 12:28:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0939821473 for ; Fri, 14 Jun 2019 12:28:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="coDrCP2b" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727887AbfFNM2A (ORCPT ); Fri, 14 Jun 2019 08:28:00 -0400 Received: from mail.skyhub.de ([5.9.137.197]:57020 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727627AbfFNM17 (ORCPT ); Fri, 14 Jun 2019 08:27:59 -0400 Received: from zn.tnic (p200300EC2F097F00E4D2751AE9C0507E.dip0.t-ipconnect.de [IPv6:2003:ec:2f09:7f00:e4d2:751a:e9c0:507e]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 5AD7F1EC0513; Fri, 14 Jun 2019 14:27:57 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1560515277; 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:in-reply-to:in-reply-to: references:references; bh=3Dy5G9geV+OkhxNXR/2joBt7M8itcKEaeTEPUiWK5cg=; b=coDrCP2bmVeuJSnmN/3W1oNa3Ql8JVRkfq/B3SEv8X7Mt8ixHO4pNBKAn6hXX1SpDg9Whc VQdicFzEmmL1yWiUr5lt28jde3a9JheUd+Zte6rR8ZPjMTk3qMr0E8zGDqD/CXKODn1Cie V7K3UcEvAPAfA4wnGPnsM/wTAWpVNWw= Date: Fri, 14 Jun 2019 14:27:50 +0200 From: Borislav Petkov To: Fenghua Yu Cc: Thomas Gleixner , Ingo Molnar , H Peter Anvin , Christopherson Sean J , Ravi V Shankar , linux-kernel , x86 Subject: Re: [RFC PATCH 2/3] x86/cpufeatures: Combine word 11 and 12 into new scattered features word 11 Message-ID: <20190614122749.GE2586@zn.tnic> References: <1560459064-195037-1-git-send-email-fenghua.yu@intel.com> <1560459064-195037-3-git-send-email-fenghua.yu@intel.com> <20190614114410.GD2586@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190614114410.GD2586@zn.tnic> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 14, 2019 at 01:44:10PM +0200, Borislav Petkov wrote: > On Thu, Jun 13, 2019 at 01:51:03PM -0700, Fenghua Yu wrote: > > It's a waste for the four X86_FEATURE_CQM_* features to occupy two > > pure feature bits words. To better utilize feature words, re-define > > word 11 to host scattered features and move the four X86_FEATURE_CQM_* > > features into word 11. More scattered features can be added in word 11 > > in the future. > > > > KVM doesn't support resctrl now. So it's safe to move the > > X86_FEATURE_CQM_* features to scattered features word 11 for KVM. > > > > Signed-off-by: Fenghua Yu > > ... > > > diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h > > index 9a327d5b6d1f..d78a61408243 100644 > > --- a/arch/x86/kvm/cpuid.h > > +++ b/arch/x86/kvm/cpuid.h > > @@ -47,8 +47,6 @@ static const struct cpuid_reg reverse_cpuid[] = { > > [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX}, > > [CPUID_7_0_EBX] = { 7, 0, CPUID_EBX}, > > [CPUID_D_1_EAX] = { 0xd, 1, CPUID_EAX}, > > - [CPUID_F_0_EDX] = { 0xf, 0, CPUID_EDX}, > > - [CPUID_F_1_EDX] = { 0xf, 1, CPUID_EDX}, > > I think you're going to have to change those to: > > [CPUID_LNX_4] = { 0, 0, 0}, > [CPUID_7_1_EAX] = { 7, 1, CPUID_EAX }, > > instead of removing them because kvm is basically hardcoding the feature > words and then bitches when array elements in the middle get removed: Alternatively - and what I think is the better solution - would be to remove those BUILD_BUG_ONs in x86_feature_cpuid and filter out the Linux-defined leafs dynamically. This way the array won't have holes in it. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.