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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED 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 C8E15C433C1 for ; Fri, 26 Mar 2021 21:13:45 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 420D5619CB for ; Fri, 26 Mar 2021 21:13:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 420D5619CB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xs4all.nl Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id E598141869; Fri, 26 Mar 2021 21:13:44 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id POGlmBRs-KAi; Fri, 26 Mar 2021 21:13:44 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTP id 9E6634185C; Fri, 26 Mar 2021 21:13:43 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 68C72C000C; Fri, 26 Mar 2021 21:13:43 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 8679DC000A for ; Fri, 26 Mar 2021 21:13:42 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 665A34060F for ; Fri, 26 Mar 2021 21:13:42 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wPDTbGjFVjG7 for ; Fri, 26 Mar 2021 21:13:40 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from sibelius.xs4all.nl (sibelius.xs4all.nl [83.163.83.176]) by smtp2.osuosl.org (Postfix) with ESMTPS id EE01040245 for ; Fri, 26 Mar 2021 21:13:39 +0000 (UTC) Received: from localhost (bloch.sibelius.xs4all.nl [local]) by bloch.sibelius.xs4all.nl (OpenSMTPD) with ESMTPA id 753b7a91; Fri, 26 Mar 2021 22:13:35 +0100 (CET) Date: Fri, 26 Mar 2021 22:13:35 +0100 (CET) From: Mark Kettenis To: Arnd Bergmann In-Reply-To: (message from Arnd Bergmann on Fri, 26 Mar 2021 21:03:32 +0100) Subject: Re: [PATCH 0/3] Apple M1 DART IOMMU driver References: <20210320151903.60759-1-sven@svenpeter.dev> <20210323205346.GA1283560@robh.at.kernel.org> <43685c67-6d9c-4e72-b320-0462c2273bf0@www.fastmail.com> <9f06872d-f0ec-43c3-9b53-d144337100b3@www.fastmail.com> Message-ID: Cc: robh@kernel.org, sven@svenpeter.dev, devicetree@vger.kernel.org, will@kernel.org, marcan@marcan.st, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, maz@kernel.org, mohamed.mediouni@caramail.com, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, stan@corellium.com X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" > From: Arnd Bergmann > Date: Fri, 26 Mar 2021 21:03:32 +0100 > > On Fri, Mar 26, 2021 at 6:28 PM Mark Kettenis wrote: > > > I haven't figured out how the bypass stuff really works. Corellium > > added support for it in their codebase when they added support for > > Thunderbolt, and some of the DARTs that seem to be related to > > Thunderbolt do indeed have a "bypass" property. But it is unclear to > > me how the different puzzle pieces fit together for Thunderbolt. > > As a general observation, bypass mode for Thunderbolt is what enabled > the http://thunderclap.io/ attack. This is extremely useful for debugging > a running kernel from another machine, but it's also something that > should never be done in a production kernel. No kidding! I was surprised to see the bypass support on the Thunderbolt-related nodes. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu