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=-5.2 required=3.0 tests=BAYES_00, 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 BFD36C433E2 for ; Wed, 16 Sep 2020 20:53:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 695D121941 for ; Wed, 16 Sep 2020 20:53:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726474AbgIPUxT (ORCPT ); Wed, 16 Sep 2020 16:53:19 -0400 Received: from mga04.intel.com ([192.55.52.120]:13136 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726148AbgIPQyM (ORCPT ); Wed, 16 Sep 2020 12:54:12 -0400 IronPort-SDR: 8HqMQoiHwnKsKVk9c9Qg+y9Ko7Kywo5jJOh+sNapwxQ5KFCVV3CYlTbb8bjdm3+ZBDvHTF39Ps 2r6eiYq8dozQ== X-IronPort-AV: E=McAfee;i="6000,8403,9746"; a="156898385" X-IronPort-AV: E=Sophos;i="5.76,433,1592895600"; d="scan'208";a="156898385" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2020 09:33:47 -0700 IronPort-SDR: JwVurvYhdZ9tRNeyZ2bbSVR/msRNcTlCZbI75pYea8hcHpWEOxy1xzYyq7jZQ44LRp/Ad7T+y3 RKc/qzoQ1Cbg== X-IronPort-AV: E=Sophos;i="5.76,433,1592895600"; d="scan'208";a="307104962" Received: from otc-nc-03.jf.intel.com (HELO otc-nc-03) ([10.54.39.36]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2020 09:33:45 -0700 Date: Wed, 16 Sep 2020 09:33:43 -0700 From: "Raj, Ashok" To: Jason Gunthorpe Cc: "Jacob Pan (Jun)" , Alex Williamson , Jean-Philippe Brucker , Jason Wang , Liu Yi L , eric.auger@redhat.com, baolu.lu@linux.intel.com, joro@8bytes.org, kevin.tian@intel.com, jun.j.tian@intel.com, yi.y.sun@intel.com, peterx@redhat.com, hao.wu@intel.com, stefanha@gmail.com, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, "Michael S. Tsirkin" , jacob.jun.pan@linux.intel.com, Ashok Raj Subject: Re: [PATCH v7 00/16] vfio: expose virtual Shared Virtual Addressing to VMs Message-ID: <20200916163343.GA76252@otc-nc-03> References: <20200914122328.0a262a7b@x1.home> <20200914190057.GM904879@nvidia.com> <20200914224438.GA65940@otc-nc-03> <20200915113341.GW904879@nvidia.com> <20200915181154.GA70770@otc-nc-03> <20200915184510.GB1573713@nvidia.com> <20200915150851.76436ca1@jacob-builder> <20200915235126.GK1573713@nvidia.com> <20200915171319.00003f59@linux.intel.com> <20200916150754.GE6199@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200916150754.GE6199@nvidia.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Sep 16, 2020 at 12:07:54PM -0300, Jason Gunthorpe wrote: > On Tue, Sep 15, 2020 at 05:22:26PM -0700, Jacob Pan (Jun) wrote: > > > If user space wants to bind page tables, create the PASID with > > > /dev/sva, use ioctls there to setup the page table the way it wants, > > > then pass the now configured PASID to a driver that can use it. > > > > Are we talking about bare metal SVA? > > What a weird term. Glad you noticed it at v7 :-) Any suggestions on something less weird than Shared Virtual Addressing? There is a reason why we moved from SVM to SVA. > > > If so, I don't see the need for userspace to know there is a > > PASID. All user space need is that my current mm is bound to a > > device by the driver. So it can be a one-step process for user > > instead of two. > > You've missed the entire point of the conversation, VDPA already needs > more than "my current mm is bound to a device" You mean current version of vDPA? or a potential future version of vDPA? Cheers, Ashok