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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, 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 C7C84C433B4 for ; Wed, 28 Apr 2021 14:11:51 +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 6EED46143E for ; Wed, 28 Apr 2021 14:11:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6EED46143E Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.119403.225870 (Exim 4.92) (envelope-from ) id 1lbkug-0003ec-Ud; Wed, 28 Apr 2021 14:11:38 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 119403.225870; Wed, 28 Apr 2021 14:11:38 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lbkug-0003eV-RZ; Wed, 28 Apr 2021 14:11:38 +0000 Received: by outflank-mailman (input) for mailman id 119403; Wed, 28 Apr 2021 14:11:36 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lbkue-0003eQ-TR for xen-devel@lists.xenproject.org; Wed, 28 Apr 2021 14:11:36 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 50185ddb-13ca-4030-a196-a9e73423a793; Wed, 28 Apr 2021 14:11:35 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D9ACEB195; Wed, 28 Apr 2021 14:11:34 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 50185ddb-13ca-4030-a196-a9e73423a793 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1619619095; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jF+yy4hFRh6bktEpd5I8Z5ZdHXSOdrEZkcW2+mFB2Vk=; b=oaAGtjuOjgQQth4VmmS23pH1zYQgb0cEptJxxXHT2ucgVhiPtxddoZ0Kw58rXsMDgC+8E3 vq6y7avf8lJ7nEvyqmoGf6wLKzqWuvenixlzBbBgTrC4UxrWVb6WhKN+5iysxWnCQmFk08 t8dmo/a85gtc6VsKj9gnfv8PBmQ8ThU= Subject: Re: [PATCH v3 3/3] xen/pci: Refactor MSI code that implements MSI functionality within XEN To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Rahul Singh Cc: xen-devel@lists.xenproject.org, bertrand.marquis@arm.com, Paul Durrant , Andrew Cooper , George Dunlap , Ian Jackson , Julien Grall , Stefano Stabellini , Wei Liu References: <7b6651f10922571a10685dc7652fbce03b6b6e51.1619453100.git.rahul.singh@arm.com> From: Jan Beulich Message-ID: <976e133f-ee94-8a2a-bc50-ebed50e2bd71@suse.com> Date: Wed, 28 Apr 2021 16:11:33 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit On 28.04.2021 13:06, Roger Pau Monné wrote: > On Mon, Apr 26, 2021 at 05:21:27PM +0100, Rahul Singh wrote: >> MSI code that implements MSI functionality to support MSI within XEN is >> not usable on ARM. Move the code under CONFIG_PCI_MSI_INTERCEPT flag to >> gate the code for ARM. >> >> Currently, we have no idea how MSI functionality will be supported for >> other architecture therefore we have decided to move the code under >> CONFIG_PCI_MSI_INTERCEPT. We know this is not the right flag to gate the >> code but to avoid an extra flag we decided to use this. >> >> No functional change intended. >> >> Signed-off-by: Rahul Singh > > I think this is fine, as we don't really want to add another Kconfig > option (ie: CONFIG_PCI_MSI) for just the non explicitly intercept MSI > code. While a separate config option may be excessive, keying it to the wrong one is not desirable imo. If we want to avoid having PCI_MSI, then keeping respective bits guarded by X86 would look better to me. I'm not convinced though that doing the separation properly right away (see also the XSM changes in patch 2 which imo belong here) isn't going to be better in the long run, and hence introducing HAS_PCI_MSI right away isn't the way to go. Jan