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=-2.5 required=3.0 tests=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 C2521C46499 for ; Fri, 5 Jul 2019 21:16:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 94E1520449 for ; Fri, 5 Jul 2019 21:16:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728224AbfGEVQz (ORCPT ); Fri, 5 Jul 2019 17:16:55 -0400 Received: from esa6.hc3370-68.iphmx.com ([216.71.155.175]:19981 "EHLO esa6.hc3370-68.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726851AbfGEVQy (ORCPT ); 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client-ip=162.221.158.21; receiver=esa6.hc3370-68.iphmx.com; envelope-from="Andrew.Cooper3@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible IronPort-SDR: gMwBDfrb6tWf/cT88R2Qs28nd9UiCuKEHQBa4F7achPnC2eWHqsEJH4aBk33RhLLepF/Lvsc5I HEUJEqWa5TmLuf0XoHprYEGKPF6YZxVD/M0qjcfV6NauEU4XchN9K/UA5uLv8Kim+4QbGvb4n1 j29UFR3RiGI+ej+h/SgMMJDObu46dkZXiyFeD8zfocska6CO9D1Td0E1kGZoQMyu3WWPI/4zVg Yb2UkXXj5KjW0y1ngLv7e9rYs//1zzUI73Zb0f6RdyG0IaL/iF3n6M9VmsLmSE3GW7tydSHW// p54= X-SBRS: 2.7 X-MesageID: 2671260 X-Ironport-Server: esa6.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.63,456,1557201600"; d="scan'208";a="2671260" Subject: Re: [patch V2 04/25] x86/apic: Make apic_pending_intr_clear() more robust To: Paolo Bonzini , Thomas Gleixner CC: LKML , , Nadav Amit , Ricardo Neri , Stephane Eranian , Feng Tang , "Andy Lutomirski" , Alex Williamson , Andrew Cooper References: <20190704155145.617706117@linutronix.de> <20190704155608.636478018@linutronix.de> <958a67c2-4dc0-52e6-43b2-1ebd25a59232@citrix.com> <3e9c8e2b-db98-6796-5241-7405f8c57564@redhat.com> From: Andrew Cooper Openpgp: preference=signencrypt Autocrypt: addr=andrew.cooper3@citrix.com; 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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <3e9c8e2b-db98-6796-5241-7405f8c57564@redhat.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Content-Language: en-GB X-ClientProxiedBy: AMSPEX02CAS02.citrite.net (10.69.22.113) To AMSPEX02CL02.citrite.net (10.69.22.126) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/07/2019 21:49, Paolo Bonzini wrote: > On 05/07/19 22:25, Thomas Gleixner wrote: >> In practice, this makes Linux vulnerable to CVE-2011-1898 / XSA-3, which >> I'm disappointed to see wasn't shared with other software vendors at the >> time. > Oh, that brings back memories. At the time I was working on Xen, so I > remember that CVE. IIRC there was some mitigation but the fix was > basically to print a very scary error message if you used VT-d without > interrupt remapping. Maybe force the user to add something on the Xen > command line too? It was before my time.  I have no public comment on how the other aspects of it were handled. >> Is there any serious usage of virtualization w/o interrupt remapping left >> or have the machines which are not capable been retired already? > I think they were already starting to disappear in 2011, as I don't > remember much worry about customers that were using systems without it. ISTR Nehalem/Westmere era systems were the first to support interrupt remapping, but were totally crippled with errata to the point of needing to turn a prerequisite feature (Queued Invalidation) off.  I believe later systems have it working to a first approximation. As to the original question, whether people should be using such systems is a different question to whether they actually are. ~Andrew