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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AAADC352A1 for ; Tue, 6 Dec 2022 14:00:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234670AbiLFOAR (ORCPT ); Tue, 6 Dec 2022 09:00:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234507AbiLFOAO (ORCPT ); Tue, 6 Dec 2022 09:00:14 -0500 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5C993B1; Tue, 6 Dec 2022 06:00:13 -0800 (PST) Received: by verein.lst.de (Postfix, from userid 2407) id 8B58B68B05; Tue, 6 Dec 2022 15:00:03 +0100 (CET) Date: Tue, 6 Dec 2022 15:00:02 +0100 From: Christoph Hellwig To: Jason Gunthorpe Cc: Christoph Hellwig , Lei Rao , kbusch@kernel.org, axboe@fb.com, kch@nvidia.com, sagi@grimberg.me, alex.williamson@redhat.com, cohuck@redhat.com, yishaih@nvidia.com, shameerali.kolothum.thodi@huawei.com, kevin.tian@intel.com, mjrosato@linux.ibm.com, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, kvm@vger.kernel.org, eddie.dong@intel.com, yadong.li@intel.com, yi.l.liu@intel.com, Konrad.wilk@oracle.com, stephen@eideticom.com, hang.yuan@intel.com Subject: Re: [RFC PATCH 5/5] nvme-vfio: Add a document for the NVMe device Message-ID: <20221206140002.GB27689@lst.de> References: <20221206055816.292304-1-lei.rao@intel.com> <20221206055816.292304-6-lei.rao@intel.com> <20221206062604.GB6595@lst.de> <20221206130901.GB24358@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Dec 06, 2022 at 09:52:54AM -0400, Jason Gunthorpe wrote: > On Tue, Dec 06, 2022 at 02:09:01PM +0100, Christoph Hellwig wrote: > > On Tue, Dec 06, 2022 at 09:05:05AM -0400, Jason Gunthorpe wrote: > > > In this case Intel has a real PCI SRIOV VF to expose to the guest, > > > with a full VF RID. > > > > RID? > > "Requester ID" - PCI SIG term that in Linux basically means you get to > assign an iommu_domain to the vfio device. Yeah I now the Requester ID, I've just never seen that shortcut for it. > >From what I understood this series basically allows two Intel devices > to pass a big opaque blob of data. Intel didn't document what is in > that blob, so I assume it captures everything you mention above. Which would be just as bad, because it then changes the IDs under the live OS on a restore. This is not something that can be done behind the back of the hypervisors / control plane OS.