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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 800C6C433E0 for ; Sat, 16 May 2020 15:02:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5573D20709 for ; Sat, 16 May 2020 15:02:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="IPqHeO5c" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726727AbgEPPCe (ORCPT ); Sat, 16 May 2020 11:02:34 -0400 Received: from mail.skyhub.de ([5.9.137.197]:38198 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726409AbgEPPCe (ORCPT ); Sat, 16 May 2020 11:02:34 -0400 Received: from zn.tnic (p200300ec2f1da500c93c46d36c4c5f0e.dip0.t-ipconnect.de [IPv6:2003:ec:2f1d:a500:c93c:46d3:6c4c:5f0e]) (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 B97231EC02F2; Sat, 16 May 2020 17:02:32 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1589641352; 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=ScgOQebiGu0KeKXh1PZEQWVWq+c5AmF15qTFduVQGXc=; b=IPqHeO5coInW11hgf9AkTZo3U0blIynxV017ZOVLgsm6XC/uSTQn72SAog15bV+avspk5/ Egvimq2hkuA/j2zotw7DLFSi1TQTYl1NYWR3X9MBIa+CQ0GY/VD30jcN2//0hFbnhFQ7e4 7rdWGnOANwk5CVEFBRu29YEW59TA6wg= Date: Sat, 16 May 2020 17:02:29 +0200 From: Borislav Petkov To: "Luck, Tony" Cc: Jue Wang , "Williams, Dan J" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] x86/mm: Don't try to change poison pages to uncacheable in a guest Message-ID: <20200516150229.GB19372@zn.tnic> References: <20200505184648.2264-1-tony.luck@intel.com> <20200516065431.GB25771@zn.tnic> <1138B55F-89DD-4ABA-98C2-61D2ED961764@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1138B55F-89DD-4ABA-98C2-61D2ED961764@intel.com> 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 Sat, May 16, 2020 at 02:47:42PM +0000, Luck, Tony wrote: > There is only one actual machine check. But the VMM simulates a second > machine check to the guest when the guest tries to access the poisoned > page. If the VMM unmaps the bad page, why doesn't the guest get a #PF instead injected by the VMM instead of latter injecting a second #MCE? If the guest tries to access an unmapped page, it should get a #PF, I'd expect. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette