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=-8.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 D98ACC43461 for ; Wed, 16 Sep 2020 02:34:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95BB520BED for ; Wed, 16 Sep 2020 02:34:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aCNcGLav" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726303AbgIPCe2 (ORCPT ); Tue, 15 Sep 2020 22:34:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:21064 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726260AbgIPCeZ (ORCPT ); Tue, 15 Sep 2020 22:34:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600223663; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qnumBkA+KwFilA4RJOFxl4BV5Ql5BJOBeoDcSO1RlRY=; b=aCNcGLavzxPNlcyuE3SEyq5DE+T5u8CeYURjtVoZWT1FDjdU2Zzdd92f0k7F+pCBvcythU T9Bc0Zax4rt2Np//Nl+Io6+dWhQxQAprWx/oXk9iuONjAWt5kOhnvJi9wBEugtlP5lKOcD j8nigaD18zxUz9wAEoFs0qG7eAP1aJk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-25-p9uQ44heN9OKqanwlBSB6w-1; Tue, 15 Sep 2020 22:34:20 -0400 X-MC-Unique: p9uQ44heN9OKqanwlBSB6w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DA4241084C80; Wed, 16 Sep 2020 02:34:17 +0000 (UTC) Received: from [10.72.13.186] (ovpn-13-186.pek2.redhat.com [10.72.13.186]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5A2821C4; Wed, 16 Sep 2020 02:33:56 +0000 (UTC) Subject: Re: [PATCH v7 00/16] vfio: expose virtual Shared Virtual Addressing to VMs To: "Raj, Ashok" , Jason Gunthorpe Cc: Alex Williamson , Jean-Philippe Brucker , Liu Yi L , eric.auger@redhat.com, baolu.lu@linux.intel.com, joro@8bytes.org, kevin.tian@intel.com, jacob.jun.pan@linux.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" , Jacon Jun Pan References: <20200914162247.GA63399@otc-nc-03> <20200914163354.GG904879@nvidia.com> <20200914105857.3f88a271@x1.home> <20200914174121.GI904879@nvidia.com> <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> <20200915192632.GA71024@otc-nc-03> From: Jason Wang Message-ID: <9e865ab2-9ff9-8af4-7051-96a42f270f06@redhat.com> Date: Wed, 16 Sep 2020 10:33:53 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200915192632.GA71024@otc-nc-03> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2020/9/16 上午3:26, Raj, Ashok wrote: >>> IIUC, you are asking that part of the interface to move to a API interface >>> that potentially the new /dev/sva and VFIO could share? I think the API's >>> for PASID management themselves are generic (Jean's patchset + Jacob's >>> ioasid set management). >> Yes, the in kernel APIs are pretty generic now, and can be used by >> many types of drivers. > Good, so there is no new requirements here I suppose. The requirement is not for in-kernel APIs but a generic uAPIs. >> As JasonW kicked this off, VDPA will need all this identical stuff >> too. We already know this, and I think Intel VDPA HW will need it, so >> it should concern you too:) > This is one of those things that I would disagree and commit :-).. > >> A PASID vIOMMU solution sharable with VDPA and VFIO, based on a PASID >> control char dev (eg /dev/sva, or maybe /dev/iommu) seems like a >> reasonable starting point for discussion. > Looks like now we are getting closer to what we need.:-) > > Given that PASID api's are general purpose today and any driver can use it > to take advantage. VFIO fortunately or unfortunately has the IOMMU things > abstracted. I suppose that support is also mostly built on top of the > generic iommu* api abstractions in a vendor neutral way? > > I'm still lost on what is missing that vDPA can't build on top of what is > available? For sure it can, but we may end up duplicated (or similar) uAPIs which is bad. Thanks > > Cheers, > Ashok >