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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 8118DC433ED for ; Mon, 17 May 2021 18:27:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DACD611BE for ; Mon, 17 May 2021 18:27:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237020AbhEQS25 (ORCPT ); Mon, 17 May 2021 14:28:57 -0400 Received: from mga17.intel.com ([192.55.52.151]:17147 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233592AbhEQS2z (ORCPT ); Mon, 17 May 2021 14:28:55 -0400 IronPort-SDR: YjMTZCGkoQQhWyf2PNgqEJZtPuHOILB7a5+vP/cxJOOimoLOwVQYRY1UAEJ4YAfss3U+feT/4P HQ0L7870ming== X-IronPort-AV: E=McAfee;i="6200,9189,9987"; a="180812523" X-IronPort-AV: E=Sophos;i="5.82,307,1613462400"; d="scan'208";a="180812523" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2021 11:27:37 -0700 IronPort-SDR: 3g4wahcMquEIn9pC7wPTvUqmPsuxEsWz+PdKJfmj7EJmI6N6zOBV03b3r+ixWosiRLhSetr7pq ICUV4CvXG3Ig== X-IronPort-AV: E=Sophos;i="5.82,307,1613462400"; d="scan'208";a="393625340" Received: from jtshade-mobl.amr.corp.intel.com (HELO skuppusw-mobl5.amr.corp.intel.com) ([10.212.100.65]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2021 11:27:35 -0700 Subject: Re: [RFC v2 26/32] x86/mm: Move force_dma_unencrypted() to common code To: Sean Christopherson , Andi Kleen Cc: Dave Hansen , "Kirill A. Shutemov" , Peter Zijlstra , Andy Lutomirski , Dan Williams , Tony Luck , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Raj Ashok , linux-kernel@vger.kernel.org References: <7c5adf75d69ea327b22b404b7c37b29712d73640.1619458733.git.sathyanarayanan.kuppuswamy@linux.intel.com> <5536639a-918d-de8d-ff32-934a13902a03@intel.com> <20210512130821.7r2rtzcyjltecun7@box.shutemov.name> <943645b7-3974-bf05-073c-03ef4f889379@intel.com> From: "Kuppuswamy, Sathyanarayanan" Message-ID: Date: Mon, 17 May 2021 11:27:31 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/17/21 11:16 AM, Sean Christopherson wrote: > What generic code needs access to SEV vs. TDX? force_dma_unencrypted() is called > from generic code, but its implementation is x86 specific. When the hardening the drivers for TDX usage, we will have requirement to check for is_protected_guest() to add code specific to protected guests. Since this will be outside arch/x86, we need common framework for it. Few examples are, * ACPI sleep driver uses WBINVD (when doing cache flushes). We want to skip it for TDX. * Forcing virtio to use dma API when running with untrusted host. -- Sathyanarayanan Kuppuswamy Linux Kernel Developer