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=-2.3 required=3.0 tests=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 4F614C76188 for ; Mon, 22 Jul 2019 14:41:15 +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 2EC8821985 for ; Mon, 22 Jul 2019 14:41:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EC8821985 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org 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 070ACBE4; Mon, 22 Jul 2019 14:41:15 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id C8FF4AE0 for ; Mon, 22 Jul 2019 14:41:13 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 6A571224 for ; Mon, 22 Jul 2019 14:41:05 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id CF05D1F2; Mon, 22 Jul 2019 16:41:03 +0200 (CEST) Date: Mon, 22 Jul 2019 16:41:02 +0200 From: Joerg Roedel To: Sai Praneeth Prakhya Subject: Re: [PATCH RFC 0/4] iommu: Add support to change default domain of a group Message-ID: <20190722144102.GC12009@8bytes.org> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Cc: Ashok Raj , Will Deacon , iommu@lists.linux-foundation.org, Robin Murphy , Christoph Hellwig 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 Tue, Jul 02, 2019 at 06:53:58PM -0700, Sai Praneeth Prakhya wrote: > Assume a use case where-in the priviliged user would want to use the device in > pass-through mode when the device is used for host but would want to switch to > dma protected mode when switching for VFIO in user space. Presently, this is not > supported and hence add support to change default domain of a group dynamically. VFIO does it's own iommu magic with the device and moves the group out of the default domain, so that doesn't sound like a valid use-case. More valid would be something like putting a device into passthrough mode to improve performance, or do you have other valid use-cases in mind? Regards, Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu