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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 BAF79C433F5 for ; Mon, 27 Aug 2018 08:33:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D282208CA for ; Mon, 27 Aug 2018 08:33:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7D282208CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727057AbeH0MTF (ORCPT ); Mon, 27 Aug 2018 08:19:05 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:41034 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726976AbeH0MTE (ORCPT ); Mon, 27 Aug 2018 08:19:04 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B9B30804B9F1; Mon, 27 Aug 2018 08:33:23 +0000 (UTC) Received: from gondolin (dhcp-192-222.str.redhat.com [10.33.192.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6A21B2166B41; Mon, 27 Aug 2018 08:33:18 +0000 (UTC) Date: Mon, 27 Aug 2018 10:33:16 +0200 From: Cornelia Huck To: Tony Krowiak Cc: Halil Pasic , Christian Borntraeger , pmorel@linux.ibm.com, Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com, frankja@linux.ibm.com Subject: Re: [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure control domains Message-ID: <20180827103316.4e7fbc10.cohuck@redhat.com> In-Reply-To: References: <1534196899-16987-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1534196899-16987-13-git-send-email-akrowiak@linux.vnet.ibm.com> <20180820162317.08bd7d23.cohuck@redhat.com> <660de00a-c403-28c1-4df4-82a973ab3ad5@linux.ibm.com> <20180821172548.57a6c758.cohuck@redhat.com> <82a391ee-85b1-cdc7-0f9b-d37fd8ba8e47@linux.ibm.com> <20180822114250.59a250aa.cohuck@redhat.com> <8bc5f207-f913-825c-f9fc-0a2c7fd280aa@linux.ibm.com> <219b352b-d5a2-189c-e205-82e7f9ae3d64@de.ibm.com> <9ef5fcb9-02e0-88e3-007c-eedb14e6db80@linux.ibm.com> <20180823122525.02fc4af3.cohuck@redhat.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 27 Aug 2018 08:33:23 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 27 Aug 2018 08:33:23 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'cohuck@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 23 Aug 2018 10:16:59 -0400 Tony Krowiak wrote: > On 08/23/2018 06:25 AM, Cornelia Huck wrote: > > On Wed, 22 Aug 2018 15:16:19 -0400 > > Tony Krowiak wrote: > > > >> One of the things I suggested in a private conversation with Christian > >> earlier > >> today was to provide an additional rw sysfs attribute - a boolean - that > >> indicates > >> whether all usage domains should also be control domains. The default > >> could be > >> true. This would allow one to configure guests with usage-only domains > >> as well > >> as satisfy the convention. > > Would this additional attribute then control "add usage domains to the > > list of control domains automatically", or "don't allow to add a usage > > domain if it has not already been added as a control domain"? > > It was just a proposal that wasn't really discussed at all, but this > attribute would add usage domains to the list of control domains > automatically if set to one. That would be the default behavior which > would be turned off by manually setting it to zero. If we want to do something like that, having it add the usage domains automatically sounds like the more workable alternative. What I like about this is that we make it explicit that we change the masks beyond what the admin explicitly configured, and provide a knob to turn off that behaviour. > > > > > One thing I'm still unsure about is how libvirt comes into the picture > > here. Will it consume the setting, or actively manipulate it? > > libvirt is not in the picture. The only thing libvirt does is identify > which mediated matrix device (i.e., UUID) is to be used by the guest. > > > > > [In general, I'm not very clear about how libvirt will interact with the > > whole infrastructure...] > > The libvirt domain XML will only specify the UUID of the matrix device > to be used by the guest. Consequently, libvirt will insert the device > statement for the vfio-ap device into the QEMU command line: > > -device vfio-ap,syfsdev={path-to-mdev} > > All configuration of the mediated device, including the proposed attribute > above, is handled via sysfs attributes. So, basically, libvirt will only consume what the admin has already configured?