From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Krowiak Subject: Re: [PATCH v11 26/26] s390: doc: detailed specifications for AP virtualization Date: Thu, 27 Sep 2018 09:12:39 -0400 Message-ID: <0c036788-9d0e-90b2-8708-98f7ff4036ad@linux.ibm.com> References: <20180925231641.4954-1-akrowiak@linux.vnet.ibm.com> <20180925231641.4954-27-akrowiak@linux.vnet.ibm.com> <20180926164222.74731b74@t450s.home> <20180927135141.0fa87f2c.cohuck@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Christian Borntraeger , Cornelia Huck , Halil Pasic Cc: Alex Williamson , 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, 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 List-ID: On 09/27/2018 07:59 AM, Christian Borntraeger wrote: > > > On 09/27/2018 01:51 PM, Cornelia Huck wrote: >> On Thu, 27 Sep 2018 13:29:43 +0200 >> Halil Pasic wrote: >> >>> On 09/27/2018 12:42 AM, Alex Williamson wrote: >>>> On Tue, 25 Sep 2018 19:16:41 -0400 >>>> Tony Krowiak wrote: >>>>> + This is how the matrix is configured for Guest2: >>>>> + >>>>> + echo 5 > assign_adapter >>>>> + echo 0x47 > assign_domain >>>>> + echo 0xff > assign_domain >>>>> + >>>>> + This is how the matrix is configured for Guest3: >>>>> + >>>>> + echo 6 > assign_adapter >>>>> + echo 0x47 > assign_domain >>>>> + echo 0xff > assign_domain >>>>> + >>>> >>>> I'm curious why this interface didn't adopt the +/- notation invented >>>> above for consistency. Too difficult to do rollbacks with a string on >>>> entries? >>>> >>> >>> I remember that we did discuss that possibility around v9, but I can't >>> tell why did we decide to not implement it. Maybe Tony has an answer. >> >> IIRC, that was a discussion on the base ap driver interfaces rather >> than vfio-ap. >> >>> >>> Anyway, if we were to do that, we would use different attribute names >>> (e.g. just domain_mask, or something similar instead of >>> (assign|unassign)_xxx). So I think such an interface can still be added >>> on top of the existing one. Having that said having multiple interfaces >>> for the very same thing is usually not so nice IMHO. >> >> Nod to all of your points. >> >> As we do the configuration while the guest is not running anyway, the >> different interfaces probably do not make that much difference in >> practice. It should be fine to stick to the current interface for now >> and only add a new one if we really think it is significantly better. > > Tony, can you maybe provide a quick on-top patch that clarifies Alex > comments regarding the documentation? (State that is is big endian, > fixup the small things etc). > I can then either fold it in or provide it as an on top patch depending > on how much has changed. Will do. >