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 smtp1.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 smtp.lore.kernel.org (Postfix) with ESMTPS id 23556C433EF for ; Thu, 24 Feb 2022 05:30:52 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id BE97783112; Thu, 24 Feb 2022 05:30:51 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tzp2jQiruVcS; Thu, 24 Feb 2022 05:30:51 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id A044883126; Thu, 24 Feb 2022 05:30:50 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7990FC0035; Thu, 24 Feb 2022 05:30:50 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id B7A22C0011 for ; Thu, 24 Feb 2022 05:30:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id A365F400E5 for ; Thu, 24 Feb 2022 05:30:49 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp2.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=intel.com 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 PKyfeAMLz5BV for ; Thu, 24 Feb 2022 05:30:48 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by smtp2.osuosl.org (Postfix) with ESMTPS id D7B24400AF for ; Thu, 24 Feb 2022 05:30:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645680648; x=1677216648; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=MRJOuFFYYPPC0Fs9nMbQSx2XuzsoF0+2SRmq/hChfag=; b=IHA8amRA9LiKzlAQtVXo0GphIGqiyZvnvMPYZ6JR6RZanCYQxntQxYKl ye+NUxoPIePf5/wvRscslEJvkssx35EYwHfz2y3+DAHQkgizv2D2axZhG 4gQwUkuMDvhKhWJvCMiy3vtnlLrRQvj6+as1mwSggfkuktWW1ZaWbeJnO QeK0rhQi8xaSRZo5uSjB+e7pzrLJ+dwwTxg+ftRSAIFxeJ0OelyGT7jW1 tMJ352vaNX3bzp3xYKSDTvF4DWRQy7xMoIOvXj5kgiAju1iI4XM19qZf8 rl7uoSOnN/IJRTzbYm0PUsAxm5XdacJN8KFk3xehnpHo1Rk568MHPI7i+ w==; X-IronPort-AV: E=McAfee;i="6200,9189,10267"; a="251889007" X-IronPort-AV: E=Sophos;i="5.88,393,1635231600"; d="scan'208";a="251889007" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2022 21:30:48 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,393,1635231600"; d="scan'208";a="684161288" Received: from allen-box.sh.intel.com (HELO [10.239.159.118]) ([10.239.159.118]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2022 21:30:40 -0800 Message-ID: Date: Thu, 24 Feb 2022 13:29:11 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v6 01/11] iommu: Add dma ownership management interfaces Content-Language: en-US To: Jason Gunthorpe , Robin Murphy References: <20220218005521.172832-1-baolu.lu@linux.intel.com> <20220218005521.172832-2-baolu.lu@linux.intel.com> <20220223180244.GA390403@nvidia.com> From: Lu Baolu In-Reply-To: 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 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 2/24/22 1:16 PM, Lu Baolu wrote: > Hi Robin and Jason, > > On 2/24/22 2:02 AM, Jason Gunthorpe wrote: >> On Wed, Feb 23, 2022 at 06:00:06PM +0000, Robin Murphy wrote: >> >>> ...and equivalently just set owner_cnt directly to 0 here. I don't see a >>> realistic use-case for any driver to claim the same group more than >>> once, >>> and allowing it in the API just feels like opening up various potential >>> corners for things to get out of sync. >> I am Ok if we toss it out to get this merged, as there is no in-kernel >> user right now. > > So we don't need the owner pointer in the API anymore, right? Oh, NO. The owner token represents that the group has been claimed for user space access. And the default domain auto-attach policy will be changed accordingly. So we still need this. Sorry for the noise. Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu