From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 653E2C433DF for ; Tue, 18 Aug 2020 16:23:39 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3A96A2067C for ; Tue, 18 Aug 2020 16:23:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A96A2067C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k84OS-0007bt-5q; Tue, 18 Aug 2020 16:23:24 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k84OQ-0007bo-Dj for xen-devel@lists.xenproject.org; Tue, 18 Aug 2020 16:23:22 +0000 X-Inumbo-ID: 07c3d702-aad1-4088-8a9a-54537b8237f2 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 07c3d702-aad1-4088-8a9a-54537b8237f2; Tue, 18 Aug 2020 16:23:20 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 57846B789; Tue, 18 Aug 2020 16:23:45 +0000 (UTC) Subject: Re: [RESEND][PATCH v2 5/7] xen: include xen/guest_access.h rather than asm/guest_access.h To: Julien Grall Cc: xen-devel@lists.xenproject.org, Julien Grall , Stefano Stabellini , Volodymyr Babchuk , Andrew Cooper , George Dunlap , Ian Jackson , Wei Liu , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Paul Durrant , Jun Nakajima , Kevin Tian References: <20200730181827.1670-1-julien@xen.org> <20200730181827.1670-6-julien@xen.org> <0874b4c7-13d4-61c1-c076-c9d7cf3720c7@suse.com> <70f7a5c0-3f41-e3a7-00ea-0e620a5506e9@suse.com> <8e4685b1-157b-a7ce-72aa-75352c4985b9@xen.org> <6474b805-dda6-56ac-cbed-65e4b399081c@suse.com> <04b85927-3f76-3460-3009-078a2105616b@suse.com> <7e3dcc77-b817-29f1-df51-3bb9c45c1535@xen.org> From: Jan Beulich Message-ID: Date: Tue, 18 Aug 2020 18:23:17 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <7e3dcc77-b817-29f1-df51-3bb9c45c1535@xen.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 18.08.2020 18:20, Julien Grall wrote: > > > On 18/08/2020 17:04, Jan Beulich wrote: >> On 18.08.2020 15:14, Julien Grall wrote: >>> >>> >>> On 18/08/2020 12:32, Jan Beulich wrote: >>>> On 18.08.2020 10:58, Julien Grall wrote: >>>>>> One option. Personally I'd prefer to avoid introduction of yet another >>>>>> constant, by leveraging __XEN_GUEST_ACCESS_H__ instead. >>>>> >>>>> I thought about it but it doesn't prevent new inclusions of asm/guest_access.h. For instance, the following would still compile: >>>>> >>>>> #include >>>>> >>>>> [...] >>>>> >>>>> #include >>>> >>>> But where's the problem with this? The first #include will already >>>> have resulted in the inclusion of asm/guest_access.h, so the second >>>> #include is simply a no-op. >>> >>> A couple of reasons: >>>     1) I don't consider this solving completely your original request [1] >>>     2) I don't see how this is more important to prevent including before and not after. Both will still compile fine, we just want to avoid it. >>> >>> >>> [1] "Is there any chance you could take measures to avoid new inclusions of asm/guest_access.h to appear?" >> >> Is >> >> #include >> [...] >> #include >> >> actually a problem (as opposed to an asm/ include without any include >> of the xen/ one at all)? > > Neither of them are really a problem today. So it is not entirely clear why we would want to prevent one and not the other. If neither is a problem, why the conversion? Jan