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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,SPF_HELO_NONE,SPF_PASS 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 6C50FC4363D for ; Tue, 20 Oct 2020 13:54:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EED6622249 for ; Tue, 20 Oct 2020 13:54:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="HjA8o6ag" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407707AbgJTNys (ORCPT ); Tue, 20 Oct 2020 09:54:48 -0400 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:6801 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2407650AbgJTNyr (ORCPT ); Tue, 20 Oct 2020 09:54:47 -0400 Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Tue, 20 Oct 2020 06:54:00 -0700 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 20 Oct 2020 13:54:43 +0000 Received: from NAM11-DM6-obe.outbound.protection.outlook.com (104.47.57.177) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 20 Oct 2020 13:54:43 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=VftBuSV2zOc0xroRdU0UVkUBWaT2U/HcJrjTROlGS1m6F8m4P3ZSN3BK87FWgS3+GGND4xf+/txEtjjCAzEKpUq2yr+rpmfB5WlEMqqVLDndwxVc98j8wD+Na3y82mJokAgZUED/uLspC2Fh9prVe7JrNeaALptfOPLb+AldAjhKMHGB/SHU+GzVi1z9iO1efoKPEMtEkm7ROOCFUHzFUdAxBKzJEjINF6AaXFoyLB5CUqHIPRqRNr7F9k2t/OpyVpdkqAPJXjFln60KOJH5uiXwElZZCPgfvhT6dBGci3DuqojIpZ2XyDfRoFbyyHM0d8GXerxkQ9Y6O3nncjaBVA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=3TZbn2JcSVbUPRrPZk+3GYnABpXmYy8TuRJjUol5GoA=; b=g+QC7F7ALtLw0VH6UC6jVDnUMZZ8kJ1zo3HgV/A1ILv0wuuCVrw1oZeHirulrWOYHqNVh4MUQYdo9/NkDuNnbzQFvpmClMNPM0qmLgN2Ep9PkFtqjCjPMrXBFPVj9RAmWS79KLMsfAMdRAxSGOe8gPh4vp5ibb6MPhnrqOJDgokk+XC9EoZA1pBRaJ9uF5HVDyEYhs8B63v5dIPuSMAnoYx4vzEFflUBYRSxJe1UvQrL2emhqqyuvI/S6nyBu33SaYNRbZIzSM1ZhqJEUeUCeSZFdrS+eRzQeXc/pieoSrp+PGd3Wi5Clrqdr0JZOd0a6KKtv1i6ZzRw5OhR99geYw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none Received: from DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) by DM6PR12MB4498.namprd12.prod.outlook.com (2603:10b6:5:2a2::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3477.20; Tue, 20 Oct 2020 13:54:41 +0000 Received: from DM6PR12MB3834.namprd12.prod.outlook.com ([fe80::cdbe:f274:ad65:9a78]) by DM6PR12MB3834.namprd12.prod.outlook.com ([fe80::cdbe:f274:ad65:9a78%7]) with mapi id 15.20.3477.028; Tue, 20 Oct 2020 13:54:41 +0000 Date: Tue, 20 Oct 2020 10:54:39 -0300 From: Jason Gunthorpe To: "Liu, Yi L" CC: Jason Wang , "Tian, Kevin" , "alex.williamson@redhat.com" , "eric.auger@redhat.com" , "baolu.lu@linux.intel.com" , "joro@8bytes.org" , "jacob.jun.pan@linux.intel.com" , "Raj, Ashok" , "Tian, Jun J" , "Sun, Yi Y" , "jean-philippe@linaro.org" , "peterx@redhat.com" , "Wu, Hao" , "stefanha@gmail.com" , "iommu@lists.linux-foundation.org" , "kvm@vger.kernel.org" , "Michael S. Tsirkin" Subject: Re: (proposal) RE: [PATCH v7 00/16] vfio: expose virtual Shared Virtual Addressing to VMs Message-ID: <20201020135439.GH6219@nvidia.com> References: <45faf89a-0a40-2a7a-0a76-d7ba76d0813b@redhat.com> <9c10b681-dd7e-2e66-d501-7fcc3ff1207a@redhat.com> <21a66a96-4263-7df2-3bec-320e6f38a9de@redhat.com>

<6e478a9e-2051-c0cd-b6fd-624ff5ef0f53@redhat.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MN2PR19CA0070.namprd19.prod.outlook.com (2603:10b6:208:19b::47) To DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from mlx.ziepe.ca (156.34.48.30) by MN2PR19CA0070.namprd19.prod.outlook.com (2603:10b6:208:19b::47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3477.22 via Frontend Transport; Tue, 20 Oct 2020 13:54:41 +0000 Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kUs63-002wSV-Dd; Tue, 20 Oct 2020 10:54:39 -0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1603202040; bh=3TZbn2JcSVbUPRrPZk+3GYnABpXmYy8TuRJjUol5GoA=; h=ARC-Seal:ARC-Message-Signature:ARC-Authentication-Results:Date: From:To:CC:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:X-ClientProxiedBy:MIME-Version: X-MS-Exchange-MessageSentRepresentingType; b=HjA8o6ag3lVsL97vT98FxH+z3of6yqbNiCSge3H5/U/JmpYigOzEyXQVPOrjvWuiU BrrbVgFY+8YWHG8kKzZr2Ojr5+Nvr9uG6DgVaJGuiW86dklAlTI0B6Ct/85idkT2jB DSIyKJhemFiZ2WBl9ZSBk+8r4GUexkH9F72qsOStk6MUpJFLbyYLjc98rAWhh9mEmH AtfU9xFT+XzQs0GCBfJTULsH6w/qhGJaNs4bMp4BfVDC/pBtqydZ3upkrEeHbUUW+A w7exj7ritiv5FsFe6vwDCVzZc2s9pPB3+SWy98Dgwym/Rz9T78lYKso7Aq+ZhdaHyy JqZHjhjMReutw== Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Oct 20, 2020 at 09:40:14AM +0000, Liu, Yi L wrote: > > See previous discussion with Kevin. If I understand correctly, you expect a shared > > L2 table if vDPA and VFIO device are using the same PASID. > > L2 table sharing is not mandatory. The mapping is the same, but no need to > assume L2 tables are shared. Especially for VFIO/vDPA devices. Even within > a passthru framework, like VFIO, if the attributes of backend IOMMU are not > the same, the L2 page table are not shared, but the mapping is the same. I think not being able to share the PASID shows exactly why this VFIO centric approach is bad. Jason 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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER,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 D31B9C4363A for ; Tue, 20 Oct 2020 13:54:53 +0000 (UTC) Received: from silver.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 mail.kernel.org (Postfix) with ESMTPS id EF6C722240 for ; Tue, 20 Oct 2020 13:54:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="HjA8o6ag" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF6C722240 Authentication-Results: mail.kernel.org; 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mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none Received: from DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) by DM6PR12MB4498.namprd12.prod.outlook.com (2603:10b6:5:2a2::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3477.20; Tue, 20 Oct 2020 13:54:41 +0000 Received: from DM6PR12MB3834.namprd12.prod.outlook.com ([fe80::cdbe:f274:ad65:9a78]) by DM6PR12MB3834.namprd12.prod.outlook.com ([fe80::cdbe:f274:ad65:9a78%7]) with mapi id 15.20.3477.028; Tue, 20 Oct 2020 13:54:41 +0000 Date: Tue, 20 Oct 2020 10:54:39 -0300 From: Jason Gunthorpe To: "Liu, Yi L" Subject: Re: (proposal) RE: [PATCH v7 00/16] vfio: expose virtual Shared Virtual Addressing to VMs Message-ID: <20201020135439.GH6219@nvidia.com> References: <45faf89a-0a40-2a7a-0a76-d7ba76d0813b@redhat.com> <9c10b681-dd7e-2e66-d501-7fcc3ff1207a@redhat.com> <21a66a96-4263-7df2-3bec-320e6f38a9de@redhat.com>

<6e478a9e-2051-c0cd-b6fd-624ff5ef0f53@redhat.com> Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MN2PR19CA0070.namprd19.prod.outlook.com (2603:10b6:208:19b::47) To DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from mlx.ziepe.ca (156.34.48.30) by MN2PR19CA0070.namprd19.prod.outlook.com (2603:10b6:208:19b::47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3477.22 via Frontend Transport; Tue, 20 Oct 2020 13:54:41 +0000 Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kUs63-002wSV-Dd; Tue, 20 Oct 2020 10:54:39 -0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1603202040; bh=3TZbn2JcSVbUPRrPZk+3GYnABpXmYy8TuRJjUol5GoA=; h=ARC-Seal:ARC-Message-Signature:ARC-Authentication-Results:Date: From:To:CC:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:X-ClientProxiedBy:MIME-Version: X-MS-Exchange-MessageSentRepresentingType; b=HjA8o6ag3lVsL97vT98FxH+z3of6yqbNiCSge3H5/U/JmpYigOzEyXQVPOrjvWuiU BrrbVgFY+8YWHG8kKzZr2Ojr5+Nvr9uG6DgVaJGuiW86dklAlTI0B6Ct/85idkT2jB DSIyKJhemFiZ2WBl9ZSBk+8r4GUexkH9F72qsOStk6MUpJFLbyYLjc98rAWhh9mEmH AtfU9xFT+XzQs0GCBfJTULsH6w/qhGJaNs4bMp4BfVDC/pBtqydZ3upkrEeHbUUW+A w7exj7ritiv5FsFe6vwDCVzZc2s9pPB3+SWy98Dgwym/Rz9T78lYKso7Aq+ZhdaHyy JqZHjhjMReutw== Cc: "Tian, Jun J" , "Tian, Kevin" , "Raj, Ashok" , "kvm@vger.kernel.org" , "jean-philippe@linaro.org" , "stefanha@gmail.com" , Jason Wang , "Michael S. Tsirkin" , "Sun, Yi Y" , "alex.williamson@redhat.com" , "iommu@lists.linux-foundation.org" , "Wu, Hao" 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 Tue, Oct 20, 2020 at 09:40:14AM +0000, Liu, Yi L wrote: > > See previous discussion with Kevin. If I understand correctly, you expect a shared > > L2 table if vDPA and VFIO device are using the same PASID. > > L2 table sharing is not mandatory. The mapping is the same, but no need to > assume L2 tables are shared. Especially for VFIO/vDPA devices. Even within > a passthru framework, like VFIO, if the attributes of backend IOMMU are not > the same, the L2 page table are not shared, but the mapping is the same. I think not being able to share the PASID shows exactly why this VFIO centric approach is bad. Jason _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu