Received: by 2002:a25:1506:0:0:0:0:0 with SMTP id 6csp659749ybv; Wed, 19 Feb 2020 06:44:44 -0800 (PST) X-Google-Smtp-Source: APXvYqyiyYRE4Szje+u29TrhV51LtBSqgHpFe3qXcKnRnGJlf/tuZHzz/yQAGy9ck54Tc4WWqlo0 X-Received: by 2002:aca:dc45:: with SMTP id t66mr4972818oig.39.1582123483922; Wed, 19 Feb 2020 06:44:43 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1582123483; cv=none; d=google.com; s=arc-20160816; b=V3F6w66ShJRGFx7f+SYdV1/2k/USuU/1m00IOZ8N50fNtyKC+nbZk2p03Vw+ht6mmb iDwdpAWT3gV5w3T8T0rSxrbr5awkpHS3yNSFBuaVnOYxlg7EbMCO+hUWQPNh9w0CjEQI i8fDWK1SOTKo0yMQ0lH3SuUZNajSxjsRxvu1QY35j0bw0h0Vbt4AH/HQK05SKyVrhT3B wF06PuMIP13kEaDqFd97BrJe78ChDi1fxwhle/hGd4dpIQsoI2j3q6rDF54Um//PsKIc oZRU5Gt+AlXXNZh49EZmqCWDZDewvrwFq3nbs42xpeLaw7jjPOHMFouVSwm7HDKhlZzb GXsA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=R9S+fJZVrq50eOUEF8rI2ReG0g4IgbKjuDpJyo13/3Q=; b=IriKZIax1c1r2fZuAejS3EIJ2wncHwuNhsFaaBU6bOlKQYOZ6/+Vfl+tC3gROH1Lkj El/pt8Q/NPIZou3yGR3zsn4Qb3BBTSdJHFZbQat1S+LqNCsZSx3VgcBIV37GHYmEoG7f 1kUoXkMoirx7GAicksjG6lyRDwXiNma+mSh25qz0Efcn3/tnZ9U3He7X2GD2+PJuwK0o 7B8HTx77SQjJ9WjKdvhHzcFQdjxv78ZpLlEOMVcTQJjNTY6HqdMnKZg2S8ftF+JnIUVD /544xyMqEeSFwmnX/C2AUVrtdxxA0wVGyVDGhTbVQhKrzEiJZDekj23MSJlXWU+fY784 OW4w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=ndhB4WdC; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id p7si1235339ota.299.2020.02.19.06.44.31; Wed, 19 Feb 2020 06:44:43 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=ndhB4WdC; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726697AbgBSOn2 (ORCPT + 99 others); Wed, 19 Feb 2020 09:43:28 -0500 Received: from mail.skyhub.de ([5.9.137.197]:36210 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726582AbgBSOn2 (ORCPT ); Wed, 19 Feb 2020 09:43:28 -0500 Received: from zn.tnic (p200300EC2F095500AC4EBF6CAFE7BFD1.dip0.t-ipconnect.de [IPv6:2003:ec:2f09:5500:ac4e:bf6c:afe7:bfd1]) (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 1B5761EC0CD2; Wed, 19 Feb 2020 15:43:23 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1582123403; 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=R9S+fJZVrq50eOUEF8rI2ReG0g4IgbKjuDpJyo13/3Q=; b=ndhB4WdCd1C0ZRq2oXpWB2XKP5QMzeL088a1yk5T+moEorrOuGn2Nh3lNpwzND5OmEKkn1 GDFVkhdW8uvHTQ7jOgkpZIh/Fl2UHcMnVvGlj59JcUJS9roGbpmYse1rqRubEEF/23vKCb sTyXT2r7yLOSqUnhXxGOenE4jedPSp0= Date: Wed, 19 Feb 2020 15:43:18 +0100 From: Borislav Petkov To: Steven Rostedt Cc: Peter Zijlstra , Andy Lutomirski , Tony Luck , x86-ml , lkml Subject: Re: [RFC] #MC mess Message-ID: <20200219144318.GD30966@zn.tnic> References: <20200218173150.GK14449@zn.tnic> <20200219081541.GG14914@hirez.programming.kicks-ass.net> <20200219092115.3b3cccd9@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200219092115.3b3cccd9@gandalf.local.home> 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 Wed, Feb 19, 2020 at 09:21:15AM -0500, Steven Rostedt wrote: > What would be nice is to have a NMI_IRET, that is defined as something > that wont break legacy CPUs. Where it could be just a nop iret, or maybe > if possible a "lock iret"? That is, not have a IRET_NON_NMI, as that > would be all over the place, but just the iret for NMI itself. As > that's in one place. You mean, we could keep the nested NMI thing but it won't practically get executed on NMI_IRET CPUs because there won't be any NMI nesting anymore? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette