From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Subject: Re: [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure control domains Date: Mon, 27 Aug 2018 15:51:26 +0200 Message-ID: <20180827155126.440f2170.cohuck@redhat.com> 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> <20180827103316.4e7fbc10.cohuck@redhat.com> <65cb82b5-85ce-1831-5b2a-719d2cf27be8@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 To: Tony Krowiak Return-path: In-Reply-To: <65cb82b5-85ce-1831-5b2a-719d2cf27be8@linux.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Mon, 27 Aug 2018 09:47:58 -0400 Tony Krowiak wrote: > On 08/27/2018 04:33 AM, Cornelia Huck wrote: > > 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. > > So, are you saying I should go ahead and implement this? I'm just saying that it does not sound like a bad idea :) If you agree that it's a good idea and if others also like it... I'd certainly not mind you going ahead :)