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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 12E4DC3A5A6 for ; Tue, 27 Aug 2019 18:24:09 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 DB8E022CBB for ; Tue, 27 Aug 2019 18:24:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB8E022CBB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 81E9D1B26; Tue, 27 Aug 2019 18:24:08 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 145721380 for ; Tue, 27 Aug 2019 18:24:08 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A13BE89B for ; Tue, 27 Aug 2019 18:24:07 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Aug 2019 11:24:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,438,1559545200"; d="scan'208";a="171282551" Received: from orsmsx107.amr.corp.intel.com ([10.22.240.5]) by orsmga007.jf.intel.com with ESMTP; 27 Aug 2019 11:24:06 -0700 Received: from orsmsx154.amr.corp.intel.com (10.22.226.12) by ORSMSX107.amr.corp.intel.com (10.22.240.5) with Microsoft SMTP Server (TLS) id 14.3.439.0; Tue, 27 Aug 2019 11:24:06 -0700 Received: from orsmsx101.amr.corp.intel.com ([169.254.8.119]) by ORSMSX154.amr.corp.intel.com ([169.254.11.172]) with mapi id 14.03.0439.000; Tue, 27 Aug 2019 11:24:06 -0700 From: "Derrick, Jonathan" To: "hch@lst.de" , "x86@kernel.org" Subject: Re: [PATCH] vmd: Stop overriding dma_map_ops Thread-Topic: [PATCH] vmd: Stop overriding dma_map_ops Thread-Index: AQHVXB/0iQzKFLmxFEGBMerx1QuVCqcPxk4A Date: Tue, 27 Aug 2019 18:24:05 +0000 Message-ID: <8cad7eb5b5b37aeb041fd0c464383bb5223e4a64.camel@intel.com> References: <20190826150652.10316-1-hch@lst.de> In-Reply-To: <20190826150652.10316-1-hch@lst.de> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.232.115.165] Content-ID: MIME-Version: 1.0 Cc: "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Busch, Keith" , "iommu@lists.linux-foundation.org" , "bhelgaas@google.com" , "dwmw2@infradead.org" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Mon, 2019-08-26 at 17:06 +0200, Christoph Hellwig wrote: > With a little tweak to the intel-iommu code we should be able to work > around the VMD mess for the requester IDs without having to create giant > amounts of boilerplate DMA ops wrapping code. The other advantage of > this scheme is that we can respect the real DMA masks for the actual > devices, and I bet it will only be a matter of time until we'll see the > first DMA challeneged NVMe devices. > > The only downside is that we can't offer vmd as a module given that > intel-iommu calls into it. But the driver only has about 700 lines > of code, so this should not be a major issue. If we're going to remove its ability to be a module, and given its small size, could we make this default =y? Otherwise we risk breaking platforms which have it enabled with OSVs who miss enabling it > > This also removes the leftover bits of the X86_DEV_DMA_OPS dma_map_ops > registry. > > Signed-off-by: Christoph Hellwig > lgtm otherwise Reviewed-by: Jon Derrick _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu