From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH v7] x86/p2m: use large pages for MMIO mappings Date: Wed, 10 Feb 2016 10:19:03 +0000 Message-ID: <56BB0E97.6060804@citrix.com> References: <56B0D61302000078000CD962@prv-mh.provo.novell.com> <56B8D8C7.3050307@citrix.com> <56B9B47302000078000CFE4F@prv-mh.provo.novell.com> <56B9C5ED.4010403@citrix.com> <56B9E01502000078000CFFDE@prv-mh.provo.novell.com> <56B9D8C4.2070706@citrix.com> <56B9EB0902000078000D00AA@prv-mh.provo.novell.com> <1455098769.19857.137.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aTRrZ-0005mQ-Fx for xen-devel@lists.xenproject.org; Wed, 10 Feb 2016 10:19:09 +0000 In-Reply-To: <1455098769.19857.137.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell , Jan Beulich Cc: Kevin Tian , Wei Liu , Stefano Stabellini , George Dunlap , Andrew Cooper , Ian Jackson , TimDeegan , Jun Nakajima , xen-devel , Keir Fraser List-Id: xen-devel@lists.xenproject.org On 10/02/16 10:06, Ian Campbell wrote: > On Tue, 2016-02-09 at 05:35 -0700, Jan Beulich wrote: >>> On 09.02.16 at 13:17, wrote: >>> I don't think sometimes returning the number of things you did and >>> sometimes returning zero makes any sense. My suggestion would be >>> either >>> make "nr_mfns" bidirectional (as similar fields are in the other >>> domctls) and return 0 on either full or partial success, or just return >>> the number of mfns actually mapped either on full or partial success. >> >> As said - I can see your point, and I've been considering the >> alternatives and had to decide for one. Since I've already got >> Ian's approval for the currently implementation, and since we're >> at v7 and I've already spent way more time on this than I had >> expected, I hope you understand that I'm a little hesitant to >> make more changes (perhaps even requiring re-obtaining acks, >> which has by itself been taking long enough for this patch) than >> absolutely necessary to get this in. >> >> So - Ian, do you think the alternative proposed by George >> would make for a meaningfully better interface? > > I can see his point, but for a domctl I don't think I'd be inclined to > insist on changing it, given the reasons you explain above for not wanting > to at this stage. > > I'd most likely be inclined to ack a follow up patch (from whomsoever is > motivated enough to produce one) which revved the API again though. Yes, I can certainly understand just geting this off the plate. If we fix the mmio_ro page size checks / assertion, I'm fine with the current interface. -George