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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04981ECAAA1 for ; Fri, 2 Sep 2022 05:29:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229602AbiIBF3I (ORCPT ); Fri, 2 Sep 2022 01:29:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbiIBF3G (ORCPT ); Fri, 2 Sep 2022 01:29:06 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C7CDB69F0 for ; Thu, 1 Sep 2022 22:29:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BDEA3B829DD for ; Fri, 2 Sep 2022 05:29:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04E3AC433D6; Fri, 2 Sep 2022 05:29:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662096543; bh=OLDVN7mSvjW5xGH0+pVMsmiu/y679ZGtVil1ZnUiJm4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MYx2OOcTDwTXJW22ZSEWjI7uTMCHxdDv3aS+Bfz/4nyLYfhdwYuNaxBDHm/FHpu18 cvxrrI1Vqt8wVjI8ZwEB+Zz/eDvuncNzyfcRjnlZKbU1XctLWUNmbmbDmUqwsbGUCD S+Maa6/XMYWNrCDeAd5uvG1jO74cGo1ifI6p/SD0= Date: Fri, 2 Sep 2022 07:29:00 +0200 From: Greg KH To: "Limonciello, Mario" Cc: "stable@vger.kernel.org" Subject: Re: Properly reflect IOMMU DMA Protection in 5.15.y+ Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Sep 02, 2022 at 03:00:26AM +0000, Limonciello, Mario wrote: > [Public] > > Hi, > > A sysfs file /sys/bus/thunderbolt/devices/domainX/iommu_dma_protection is exported from the kernel and used by userspace to make judgments on whether to automatically authorize PCIe tunnels for USB4 devices. > Before kernel 5.19 this file was only populated on Intel USB4 and TBT3 controllers, but starting with 5.19 it also populates for non-Intel as well. So that's a new kernel feature? > This is accomplished by an assertion from the IOMMU subsystem that it's safe to do so by a combination of firmware and hardware. > > Here is the patch series on top of 5.15.64: > > 3f6634d997dba8140b3a7cba01776b9638d70dff > ed36d04e8f8d7b00db451b0fa56a54e8e02ec43e > d0be55fbeb6ac694d15af5d1aad19cdec8cd64e5 > f316ba0a8814f4c91e80a435da3421baf0ddd24c > f1ca70717bcb4525e29da422f3d280acbddb36fe > bfb3ba32061da1a9217ef6d02fbcffb528e4c8df > 418e0a3551bbef5b221705b0e5b8412cdc0afd39 > acdb89b6c87a2d7b5c48a82756e6f5c6f599f60a > ea4692c75e1c63926e4fb0728f5775ef0d733888 > 86eaf4a5b4312bea8676fb79399d9e08b53d8e71 > > Can you please consider backporting them to 5.15.y+? I don't understand why all of the string helpers are needed just for the last commit, are you sure this is all necessary? And again, this feels like new features are being added that are much more than just a "new device id added". Why not just use 5.19 for this hardware? thanks, greg k-h