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,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 20CC8C2B9F4 for ; Mon, 14 Jun 2021 15:33:11 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 CF2266120E for ; Mon, 14 Jun 2021 15:33:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF2266120E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.141631.261548 (Exim 4.92) (envelope-from ) id 1lsoaC-0004bs-FL; Mon, 14 Jun 2021 15:33:00 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 141631.261548; Mon, 14 Jun 2021 15:33:00 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lsoaC-0004bl-CY; Mon, 14 Jun 2021 15:33:00 +0000 Received: by outflank-mailman (input) for mailman id 141631; Mon, 14 Jun 2021 15:32:58 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lsoaA-0004bV-Hb for xen-devel@lists.xenproject.org; Mon, 14 Jun 2021 15:32:58 +0000 Received: from verein.lst.de (unknown [213.95.11.211]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id a3303be7-2a60-4b62-bf20-b255421617d5; Mon, 14 Jun 2021 15:32:56 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 2740F68AFE; Mon, 14 Jun 2021 17:32:52 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: a3303be7-2a60-4b62-bf20-b255421617d5 Date: Mon, 14 Jun 2021 17:32:52 +0200 From: Christoph Hellwig To: Robin Murphy Cc: Christoph Hellwig , Tianyu Lan , kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, arnd@arndb.de, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, rppt@kernel.org, hannes@cmpxchg.org, cai@lca.pw, krish.sadhukhan@oracle.com, saravanand@fb.com, Tianyu.Lan@microsoft.com, konrad.wilk@oracle.com, m.szyprowski@samsung.com, boris.ostrovsky@oracle.com, jgross@suse.com, sstabellini@kernel.org, joro@8bytes.org, will@kernel.org, xen-devel@lists.xenproject.org, davem@davemloft.net, kuba@kernel.org, jejb@linux.ibm.com, martin.petersen@oracle.com, iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, vkuznets@redhat.com, thomas.lendacky@amd.com, brijesh.singh@amd.com, sunilmut@microsoft.com Subject: Re: [RFC PATCH V3 08/11] swiotlb: Add bounce buffer remap address setting function Message-ID: <20210614153252.GA1741@lst.de> References: <20210530150628.2063957-1-ltykernel@gmail.com> <20210530150628.2063957-9-ltykernel@gmail.com> <20210607064312.GB24478@lst.de> <94038087-a33c-93c5-27bf-7ec1f6f5f0e3@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <94038087-a33c-93c5-27bf-7ec1f6f5f0e3@arm.com> User-Agent: Mutt/1.5.17 (2007-11-01) On Mon, Jun 14, 2021 at 02:49:51PM +0100, Robin Murphy wrote: > FWIW, I think a better generalisation for this would be allowing > set_memory_decrypted() to return an address rather than implicitly > operating in-place, and hide all the various hypervisor hooks behind that. Yes, something like that would be a good idea. As-is set_memory_decrypted is a pretty horribly API anyway due to passing the address as void, and taking a size parameter while it works in units of pages. So I'd very much welcome a major overhaul of this API.