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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7706EC4321E for ; Mon, 5 Dec 2022 10:26:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231654AbiLEK0X (ORCPT ); Mon, 5 Dec 2022 05:26:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231784AbiLEKXm (ORCPT ); Mon, 5 Dec 2022 05:23:42 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7ECB6B95; Mon, 5 Dec 2022 02:23:41 -0800 (PST) Received: from zn.tnic (p200300ea9733e72f329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:9733:e72f:329c:23ff:fea6:a903]) (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 D831C1EC02F2; Mon, 5 Dec 2022 11:23:39 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1670235819; 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=KIENH15CUhhwX9YjX0bX3iizagk6GyzX+rGnIAEKctM=; b=gY3dUPabbPPGR/mlkl37DjHYhSgQoEQryb8RdaMctCffZyCyBFZS1a6xBTYu0/iCOCaIwj GijcrSyEWaVbAkHEO1pOBBlrA4uFEOym05X0M9D/5Zk6bPaz5lKWCswrY5G4asJdk0Myfq 1s596XXqz6tl0/koSToQUFBXqIjw9ts= Date: Mon, 5 Dec 2022 11:23:32 +0100 From: Borislav Petkov To: Kim Phillips Cc: x86@kernel.org, Babu Moger , Borislav Petkov , Boris Ostrovsky , Dave Hansen , "H. Peter Anvin" , Ingo Molnar , Joao Martins , Jonathan Corbet , Konrad Rzeszutek Wilk , Paolo Bonzini , Sean Christopherson , Thomas Gleixner , David Woodhouse , Greg Kroah-Hartman , Juergen Gross , Peter Zijlstra , Tony Luck , Tom Lendacky , Alexey Kardashevskiy , kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/7] x86/cpu: Define a scattered No Nested Data Breakpoints feature bit Message-ID: References: <20221201015003.295769-1-kim.phillips@amd.com> <20221201015003.295769-2-kim.phillips@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20221201015003.295769-2-kim.phillips@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Wed, Nov 30, 2022 at 07:49:57PM -0600, Kim Phillips wrote: > It's a part of the CPUID 0x80000021 leaf, and this allows us to ^^ Please use passive voice in your commit message: no "we" or "I", etc, and describe your changes in imperative mood. Personal pronouns are ambiguous in text, especially with so many parties/companies/etc developing the kernel so let's avoid them please. > group this and other CPUID 0x80000021 EAX feature bits to being > propagated via kvm_set_cpu_caps instead of open-coding them in > __do_cpuid_func(). > > Signed-off-by: Kim Phillips > --- > arch/x86/include/asm/cpufeatures.h | 1 + > arch/x86/kernel/cpu/scattered.c | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h > index 11a0e06362e4..b16fdcedc2b5 100644 > --- a/arch/x86/include/asm/cpufeatures.h > +++ b/arch/x86/include/asm/cpufeatures.h > @@ -307,6 +307,7 @@ > #define X86_FEATURE_SGX_EDECCSSA (11*32+18) /* "" SGX EDECCSSA user leaf function */ > #define X86_FEATURE_CALL_DEPTH (11*32+19) /* "" Call depth tracking for RSB stuffing */ > #define X86_FEATURE_MSR_TSX_CTRL (11*32+20) /* "" MSR IA32_TSX_CTRL (Intel) implemented */ > +#define X86_FEATURE_NO_NESTED_DATA_BP (11*32+21) /* "" AMD No Nested Data Breakpoints */ Right, what is the use of this bit in a KVM guest? Running perf tool in a guest would use that bit how? Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette