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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,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 755D7C43381 for ; Thu, 21 Mar 2019 18:43:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4850A218A2 for ; Thu, 21 Mar 2019 18:43:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="foREaUFV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728775AbfCUSnC (ORCPT ); Thu, 21 Mar 2019 14:43:02 -0400 Received: from merlin.infradead.org ([205.233.59.134]:38164 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728057AbfCUSnC (ORCPT ); Thu, 21 Mar 2019 14:43:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=uttlB9voS92ZxALrRx0JnyjxxffLvGSv6XphhQ9EYZQ=; b=foREaUFVYKsoBWeAZ8KV3iBri 8458jXg+aocUtbu0OBtlrQLQdvTw35enNrtX4GAXGG/5lK8brD/z2pfLXJzETWGrL/uTkPEZH9uhC RjRyoIC1ucUv76BFsUbJIDtsn7IQta9kNQQd67W5bEWY7WRpQDHozlVuK8Md7OwCbVzbrqUeM8Rdn hsHu/7BCg0aLmvMTmYFiN7bTwu0QhcewpgB0au1FisIs1Xgi+FlVCImSVIK/lilbHEqWjYibzZSo+ HPkPLNwWQKKd8bZ17spG0klEaltw/GEG2r31xNO4tzJqWOjtzqP6CaqJxJpFBVhlL1gAM9IHmenLD fveaQDUbA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h72e8-0001fV-LB; Thu, 21 Mar 2019 18:42:32 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 661CE21BEC724; Thu, 21 Mar 2019 19:42:31 +0100 (CET) Date: Thu, 21 Mar 2019 19:42:31 +0100 From: Peter Zijlstra To: Andy Lutomirski Cc: Linus Torvalds , Andrew Cooper , Jan Beulich , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Steven Rostedt , LKML , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Joel Fernandes , He Zhe Subject: Re: [RFC][PATCH] tracing/x86: Save CR2 before tracing irqsoff on error_entry Message-ID: <20190321184231.GR6058@hirez.programming.kicks-ass.net> References: <20190321083317.GL6058@hirez.programming.kicks-ass.net> <20190321090241.GL6521@hirez.programming.kicks-ass.net> <20190321104517.GM6521@hirez.programming.kicks-ass.net> <20190321093242.4a948198@gandalf.local.home> <20190321172203.GS5996@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Thu, Mar 21, 2019 at 11:38:25AM -0700, Andy Lutomirski wrote: > I suspect we'll want PV spinlocks and other goodies like PV TLB > shootdown for a long time. The stuff I'd like to kill eventually is > the PV "I'm not actually at CPL 0 so I'm faking it" part. Right, and it's exactly those bits that are PARAVIRT_XXL AFAIU.