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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 75583C3F2D1 for ; Thu, 5 Mar 2020 23:02:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4EFEF2073D for ; Thu, 5 Mar 2020 23:02:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726317AbgCEXCZ (ORCPT ); Thu, 5 Mar 2020 18:02:25 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:51650 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726173AbgCEXCY (ORCPT ); Thu, 5 Mar 2020 18:02:24 -0500 Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1j9zVN-0007Il-JA; Fri, 06 Mar 2020 00:02:13 +0100 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id D6D06104085; Fri, 6 Mar 2020 00:02:12 +0100 (CET) From: Thomas Gleixner To: Andy Lutomirski , LKML Cc: x86@kernel.org, Steven Rostedt , Brian Gerst , Juergen Gross , Paolo Bonzini , Arnd Bergmann Subject: Re: [patch 15/16] x86/entry: Switch page fault exceptions to idtentry_simple In-Reply-To: References: <20200225223321.231477305@linutronix.de> <20200225224145.657687951@linutronix.de> Date: Fri, 06 Mar 2020 00:02:12 +0100 Message-ID: <877dzycsnf.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andy Lutomirski writes: > On 2/25/20 2:33 PM, Thomas Gleixner wrote: >> Convert page fault exceptions to IDTENTRY_CR2: >> - Implement the C entry point with DEFINE_IDTENTRY >> - Emit the ASM stub with DECLARE_IDTENTRY >> - Remove the ASM idtentry in 64bit >> - Remove the CR2 read from 64bit >> - Remove the open coded ASM entry code in 32bit >> - Fixup the XEN/PV code >> - Remove the old prototyoes > > $SUBJECT says idtentry_simple. I think you meant IDTENTRY_CR2. Yes. > (I typed this a while ago and apparently failed to hit send. I'm not > sure it's still relevant.) No, as we agreed to create raw IDTENTRY points for stuff which does not fall into the trivial category. I've reworked the mess, but now I'm tripping over the brilliant stuff in that async PF code. The rcu_irq_enter()/exit() dance there is really great and of course done unconditionally even if called from the VM exit PF handling code. Oh well... Thanks, tglx