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=-6.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 C6EAFC4338F for ; Tue, 24 Aug 2021 17:21:05 +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 4BAD261214 for ; Tue, 24 Aug 2021 17:21:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4BAD261214 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 1EF32406BB; Tue, 24 Aug 2021 17:21:05 +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 LPi89iz-VBHX; Tue, 24 Aug 2021 17:21:01 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTPS id 9DDDC40715; Tue, 24 Aug 2021 17:21:00 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 72324C0010; Tue, 24 Aug 2021 17:21:00 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 464B6C000E for ; Tue, 24 Aug 2021 17:20:59 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 25E9F404C4 for ; Tue, 24 Aug 2021 17:20:59 +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 Cx1oAWAe6wWo for ; Tue, 24 Aug 2021 17:20:58 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by smtp2.osuosl.org (Postfix) with ESMTPS id 578A3404B7 for ; Tue, 24 Aug 2021 17:20:58 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10086"; a="204494353" X-IronPort-AV: E=Sophos;i="5.84,347,1620716400"; d="scan'208";a="204494353" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2021 10:20:48 -0700 X-IronPort-AV: E=Sophos;i="5.84,347,1620716400"; d="scan'208";a="526704367" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.209.119.65]) ([10.209.119.65]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2021 10:20:46 -0700 Subject: Re: [PATCH v4 11/15] pci: Add pci_iomap_shared{,_range} To: "Michael S. Tsirkin" References: <20210805005218.2912076-1-sathyanarayanan.kuppuswamy@linux.intel.com> <20210805005218.2912076-12-sathyanarayanan.kuppuswamy@linux.intel.com> <20210823195409-mutt-send-email-mst@kernel.org> <26a3cce5-ddf7-cbe6-a41e-58a2aea48f78@linux.intel.com> <20210824053830-mutt-send-email-mst@kernel.org> From: Andi Kleen Message-ID: Date: Tue, 24 Aug 2021 10:20:44 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210824053830-mutt-send-email-mst@kernel.org> Content-Language: en-US Cc: "Kuppuswamy, Sathyanarayanan" , Kuppuswamy Sathyanarayanan , Linux Doc Mailing List , Peter Zijlstra , Linux PCI , linux-mips@vger.kernel.org, James E J Bottomley , Dave Hansen , Peter H Anvin , sparclinux@vger.kernel.org, Thomas Gleixner , linux-arch , Jonathan Corbet , Helge Deller , X86 ML , Ingo Molnar , Arnd Bergmann , Tony Luck , Borislav Petkov , Andy Lutomirski , Bjorn Helgaas , Dan Williams , virtualization@lists.linux-foundation.org, Richard Henderson , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, Sean Christopherson , Linux Kernel Mailing List , linux-alpha@vger.kernel.org, "David S . Miller" , Kirill Shutemov X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" > I see. Hmm. It's a bit of a random thing to do it at the map time > though. E.g. DMA is all handled transparently behind the DMA API. > Hardening is much more than just replacing map with map_shared > and I suspect what you will end up with is basically > vendors replacing map with map shared to make things work > for their users and washing their hands. That concept exists too. There is a separate allow list for the drivers. So just adding shared to a driver is not enough, until it's also added to the allowlist Users can of course chose to disable the allowlist, but they need to understand the security implications. > > I would say an explicit flag in the driver that says "hardened" > and refusing to init a non hardened one would be better. We have that too (that's the device filtering) But the problem is that device filtering just stops the probe functions, not the initcalls, and lot of legacy drivers do MMIO interactions before going into probe. In some cases it's unavoidable because of the device doesn't have a separate enumeration mechanism it needs some kind of probing to even check for its existence And since we don't want to change all of them it's far safer to make the ioremap opt-in. -Andi _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization