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 Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 59A70C433FE for ; Mon, 14 Feb 2022 13:41:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 02A5960615; Mon, 14 Feb 2022 13:41:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id u7UsdQrpjmNw; Mon, 14 Feb 2022 13:41:03 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp3.osuosl.org (Postfix) with ESMTPS id DCC14605B3; Mon, 14 Feb 2022 13:41:02 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id B0004C001A; Mon, 14 Feb 2022 13:41:02 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id D41D5C000B for ; Mon, 14 Feb 2022 13:41:00 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id B31A14015E for ; Mon, 14 Feb 2022 13:41:00 +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 EFP0NaCGpCBx for ; Mon, 14 Feb 2022 13:41:00 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by smtp2.osuosl.org (Postfix) with ESMTPS id EE1D9400B8 for ; Mon, 14 Feb 2022 13:40:59 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id 029F02FB; Mon, 14 Feb 2022 14:40:57 +0100 (CET) Date: Mon, 14 Feb 2022 14:40:56 +0100 From: Joerg Roedel To: Jason Gunthorpe Subject: Re: [PATCH v1 5/8] iommu/amd: Use iommu_attach/detach_device() Message-ID: References: <20220106022053.2406748-1-baolu.lu@linux.intel.com> <20220106022053.2406748-6-baolu.lu@linux.intel.com> <20220106143345.GC2328285@nvidia.com> <20220214131544.GX4160@nvidia.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220214131544.GX4160@nvidia.com> Cc: Stuart Yoder , rafael@kernel.org, David Airlie , linux-pci@vger.kernel.org, Thierry Reding , Diana Craciun , Dmitry Osipenko , Will Deacon , Ashok Raj , Jonathan Hunter , Christoph Hellwig , Kevin Tian , Chaitanya Kulkarni , Alex Williamson , kvm@vger.kernel.org, Bjorn Helgaas , Dan Williams , Greg Kroah-Hartman , Cornelia Huck , linux-kernel@vger.kernel.org, Li Yang , iommu@lists.linux-foundation.org, Jacob jun Pan , Daniel Vetter , Robin Murphy X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 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 Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Mon, Feb 14, 2022 at 09:15:44AM -0400, Jason Gunthorpe wrote: > But how does the sound device know that this has been done to it? > > eg how do we know the sound device hasn't been bound to VFIO or > something at this point? The iommu_attach_group() call will fail when the group (which includes GPU and sound device) it not in its default-domain. So if VFIO attached the group to its own domain, there is a failure in this init function. Note that this function is intended to be called by the driver currently controling this device, so there should also be no race with VFIO trying to grab the device in parallel. Regards, Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 56B22C433EF for ; Mon, 14 Feb 2022 13:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344191AbiBNNlJ (ORCPT ); Mon, 14 Feb 2022 08:41:09 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:54580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243108AbiBNNlI (ORCPT ); Mon, 14 Feb 2022 08:41:08 -0500 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 502F9575F4; Mon, 14 Feb 2022 05:41:00 -0800 (PST) Received: by theia.8bytes.org (Postfix, from userid 1000) id 029F02FB; Mon, 14 Feb 2022 14:40:57 +0100 (CET) Date: Mon, 14 Feb 2022 14:40:56 +0100 From: Joerg Roedel To: Jason Gunthorpe Cc: Lu Baolu , Alex Williamson , Robin Murphy , Christoph Hellwig , Kevin Tian , Ashok Raj , Greg Kroah-Hartman , Bjorn Helgaas , Will Deacon , Dan Williams , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , Stuart Yoder , Laurentiu Tudor , Thierry Reding , David Airlie , Daniel Vetter , Jonathan Hunter , Li Yang , Dmitry Osipenko , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 5/8] iommu/amd: Use iommu_attach/detach_device() Message-ID: References: <20220106022053.2406748-1-baolu.lu@linux.intel.com> <20220106022053.2406748-6-baolu.lu@linux.intel.com> <20220106143345.GC2328285@nvidia.com> <20220214131544.GX4160@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220214131544.GX4160@nvidia.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Feb 14, 2022 at 09:15:44AM -0400, Jason Gunthorpe wrote: > But how does the sound device know that this has been done to it? > > eg how do we know the sound device hasn't been bound to VFIO or > something at this point? The iommu_attach_group() call will fail when the group (which includes GPU and sound device) it not in its default-domain. So if VFIO attached the group to its own domain, there is a failure in this init function. Note that this function is intended to be called by the driver currently controling this device, so there should also be no race with VFIO trying to grab the device in parallel. Regards, Joerg