Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753212AbbG1RQo (ORCPT ); Tue, 28 Jul 2015 13:16:44 -0400 Received: from smtp.citrix.com ([66.165.176.89]:25741 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751878AbbG1RQm (ORCPT ); Tue, 28 Jul 2015 13:16:42 -0400 X-IronPort-AV: E=Sophos;i="5.15,564,1432598400"; d="scan'208";a="285266400" Message-ID: <55B7B8D2.5060107@citrix.com> Date: Tue, 28 Jul 2015 18:16:02 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 MIME-Version: 1.0 To: Julien Grall , CC: , "H. Peter Anvin" , "Jiri Slaby" , Thomas Gleixner , , Russell King , , , Tomi Valkeinen , , "Jean-Christophe Plagniol-Villard" , , "James E.J. Bottomley" , Boris Ostrovsky , Ingo Molnar , , Juergen Gross , "Wei Liu" , Greg Kroah-Hartman , Dmitry Torokhov , , David Vrabel , , , =?UTF-8?B?Um9nZXIg?= =?UTF-8?B?UGF1IE1vbm7DqQ==?= Subject: Re: [Xen-devel] [PATCH 4/8] xen: Use the correctly the Xen memory terminologies References: <1438095769-2560-1-git-send-email-julien.grall@citrix.com> <1438095769-2560-5-git-send-email-julien.grall@citrix.com> In-Reply-To: <1438095769-2560-5-git-send-email-julien.grall@citrix.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1672 Lines: 38 On 28/07/15 16:02, Julien Grall wrote: > Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN > is meant, I suspect this is because the first support for Xen was for > PV. This brough some misimplementation of helpers on ARM and make the > developper confused the expected behavior. For the benefit of other subsystem maintainers, this is a purely mechanical change in Xen-specific terminology. It doesn't need reviews or acks from non-Xen people (IMO). > For instance, with pfn_to_mfn, we expect to get an MFN based on the name. > Although, if we look at the implementation on x86, it's returning a GFN. > > For clarity and avoid new confusion, replace any reference of mfn into > gnf in any helpers used by PV drivers. > > Take also the opportunity to simplify simple construction such > as pfn_to_mfn(page_to_pfn(page)) into page_to_gfn. More complex clean up > will come in follow-up patches. > > I think it may be possible to do further clean up in the x86 code to > ensure that helpers returning machine address (such as virt_address) is > not used by no auto-translated guests. I will let x86 xen expert doing > it. Reviewed-by: David Vrabel It looks a bit odd to use GFN in some of the PV code where the hypervisor API uses MFN but overall I think using the correct terminology where possible is best. But I'd like to have Boris's or Konrad's opinion on this. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/