From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-4451-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id B325358191A2 for ; Wed, 20 Jun 2018 00:54:48 -0700 (PDT) Date: Wed, 20 Jun 2018 09:54:33 +0200 From: Cornelia Huck Message-ID: <20180620095433.7bbeceb0.cohuck@redhat.com> In-Reply-To: <20180619163059.GA12527@debian> References: <2eb17c91-9158-c14f-e582-223dd6e5c6d2@linux.ibm.com> <20180615151329-mutt-send-email-mst@kernel.org> <545e8649-8029-d135-e927-3ad11f4eb29d@linux.ibm.com> <20180615154837-mutt-send-email-mst@kernel.org> <20180615183657-mutt-send-email-mst@kernel.org> <20180618191934-mutt-send-email-mst@kernel.org> <20180619091418.GA3813@debian> <634ac848-b9e5-866a-7e22-50ab8dcdae73@linux.ibm.com> <20180619163059.GA12527@debian> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [virtio-dev] [PATCH v3] content: enhance device requirements for feature bits To: Tiwei Bie Cc: Halil Pasic , "Michael S. Tsirkin" , stefanha@redhat.com, pbonzini@redhat.com, virtio-dev@lists.oasis-open.org, dan.daly@intel.com, cunming.liang@intel.com, zhihong.wang@intel.com List-ID: On Wed, 20 Jun 2018 00:30:59 +0800 Tiwei Bie wrote: > On Tue, Jun 19, 2018 at 12:46:45PM +0200, Halil Pasic wrote: > > On 06/19/2018 11:14 AM, Tiwei Bie wrote: > > > On Mon, Jun 18, 2018 at 07:28:33PM +0300, Michael S. Tsirkin wrote: > [...] > > > > > > If it would be better to drop this patch, > > > I'm fine with dropping it. Thanks! > > > > > > > @Tiwei Bie > > Thanks for your flexibility! What is your opinion (after considering the > > arguments from my previous mail), is it better to include this patch in the spec or > > is it better to drop it? Were you able to identify mistakes in my reasoning > > (I mean points (1)-(12))? > > > > Hi Halil, > > I think maybe you thought too much about this proposal > (or maybe I really missed something obvious). In my > opinion, the device requirement proposed by this patch > is quite simple and straightforward: > > - It's just to make the spec explicitly require that > a certain virtio device shouldn't fail re-negotiation > of a feature set it has successfully accepted once. > > - It covers the cases of virtio device reset and system > reset (which includes normal shutdown and start). > > I think the requirement is reasonable because for a > certain virtio device, there is no reason that the > feature bits it offers will change (because it should > always offer all the features it understands). And we > are just to add a device normative to make the spec be > more explicit about that (because if a device really > changes the features it offers after a device or > system reset, something will go wrong). If the configs > of an emulated virtio device are changed, maybe we > shouldn't treat it as the same device any more, and > IMO this case is not related to this proposal. > > Although we have 'Each virtio device offers all the > features it understands', it's not an explicit device > requirement. So I don't think it's a bad idea to > have an explicit device requirement about this. I think this reasoning is sane and we really should not overthink it. The update as has been voted on looks fine to me. --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org