From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH v2 for 4.5] xen/arm: Add support for GICv3 for domU Date: Fri, 7 Nov 2014 10:45:02 -0500 Message-ID: <20141107154502.GC14076@laptop.dumpdata.com> References: <1414872625-2961-1-git-send-email-julien.grall@linaro.org> <20141103163904.GF1638@laptop.dumpdata.com> <54590C48.4080100@linaro.org> <545A5B4F02000078000C1073@mail.emea.novell.com> <545B4325.9000801@linaro.org> <545B577D0200007800045407@mail.emea.novell.com> <545B4D1D.4090000@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1XmpVq-0002uz-Kq for xen-devel@lists.xenproject.org; Fri, 07 Nov 2014 19:48:02 +0000 Content-Disposition: inline In-Reply-To: <545B4D1D.4090000@linaro.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall Cc: wei.liu2@citrix.com, ian.campbell@citrix.com, vijay.kilari@gmail.com, stefano.stabellini@eu.citrix.com, tim@xen.org, Vijaya.Kumar@caviumnetworks.com, ian.jackson@eu.citrix.com, stefano.stabellini@citrix.com, Jan Beulich , xen-devel@lists.xenproject.org, dgdegra@tycho.nsa.gov List-Id: xen-devel@lists.xenproject.org On Thu, Nov 06, 2014 at 10:27:41AM +0000, Julien Grall wrote: > > > On 06/11/2014 10:11, Jan Beulich wrote: > >>>>On 06.11.14 at 10:45, wrote: > >>Hi Jan, > >> > >>On 05/11/2014 17:15, Jan Beulich wrote: > >>>>>>Julien Grall 11/04/14 6:27 PM >>> > >>>>On 11/03/2014 04:39 PM, Konrad Rzeszutek Wilk wrote: > >>>>>It also needs Acks from Daniel and Jan. > >>>> > >>>>This patch doesn't modify the x86 part. So I'm not sure if Jan ack is > >>>>required. Would Ian C. ack be enough? > >>> > >>>Yes, it would. > >>> > >>>>Anyway, Jan do you have any objection on this patch? > >>> > >>>As said previously, I'm not particularly happy about it, but I also don't > >>strongly > >>>mind it going in in the current shape. > >> > >>May I ask what is wrong with the new approach to the a DOMCTL in this patch? > >> > >>The DOMCTL has been clearly identify as arm specific (there is "arm" in > >>the name). Therefore it doesn't seem necessary to expose it for other > >>architecture than ARM32 and ARM64. > > > >I didn't say there's anything actively wrong with it, all I said is that > >I'm not particularly happy about it: Irrespective of its name it doesn't > >look to be really arch-specific in the long run, plus it feels like the > >data being set here should rather be specified right at domain > >creation, or via a mechanism similar to x86'es HVM parameters (iirc > >the value set here can't be changed once the domain got first > >unpaused). > > > TBH I choose this solution because I though you would be disagree with > extending the domain create hypercall. > > In long run, there will be more parameters such as the number of spis. All > will be required at the same time. So the HVM parameters solution won't > really help here. > > However, I could give a look to extending the domain creation hypercall > (xen_domctl_createdomain) to add arch specific field. > > But I don't think it's Xen 4.5 material. So I would prefer to stay on this > approach for this release because we'd like to have GICv3 guest support on > Xen. Though I could rename the DOMCTL to DOMCTL_get_gic_version. That is a bit unfortunate as it sounds like that for Xen 4.6 you will then ditch this hypercall and focus on the new one? Won't this one then be bitrotten? > > Regards, > > -- > Julien Grall