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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 5EB12C433E0 for ; Fri, 15 May 2020 15:46:29 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 2EAAB20758 for ; Fri, 15 May 2020 15:46:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EAAB20758 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 localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id EB09588D72; Fri, 15 May 2020 15:46:28 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cW86d+DIy7p5; Fri, 15 May 2020 15:46:24 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 2718988D7A; Fri, 15 May 2020 15:46:24 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id DF485C0859; Fri, 15 May 2020 15:46:23 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 31A59C016F for ; Fri, 15 May 2020 15:46:22 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 16B1987D92 for ; Fri, 15 May 2020 15:46:22 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ZESyth-jqBCh for ; Fri, 15 May 2020 15:46:21 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 2976187D8A for ; Fri, 15 May 2020 15:46:21 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id BD81B3C3; Fri, 15 May 2020 17:46:17 +0200 (CEST) Date: Fri, 15 May 2020 17:46:16 +0200 From: Joerg Roedel To: Lu Baolu Subject: Re: [PATCH] iommu: Remove functions that support private domain Message-ID: <20200515154616.GY18353@8bytes.org> References: <20200513224721.20504-1-sai.praneeth.prakhya@intel.com> <20200514131315.GJ18353@8bytes.org> <20200514183233.GO18353@8bytes.org> <20200514195615.GP18353@8bytes.org> <20200515095919.GQ18353@8bytes.org> <9d65b30a-d22e-d566-d740-601f8d638bfd@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <9d65b30a-d22e-d566-d740-601f8d638bfd@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: "iommu@lists.linux-foundation.org" 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 Fri, May 15, 2020 at 08:55:42PM +0800, Lu Baolu wrote: > It seems that we can do like this: > > [1] mutex_lock(&group->lock) > [2] for_each_group_device(device_lock()) > [3] if (for_each_group_device(!device_is_bound())) > change_default_domain() > [4] for_each_group_device_reverse(device_unlock()) > [5] mutex_unlock(&group->lock) The problem here is that I am pretty sure we also have: device_lock() /* from device/driver core code */ -> bus_notifier() -> iommu_bus_notifier() -> ... -> mutex_lock(&group->lock) Which would cause lock-inversion with the above code. Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu