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=-14.6 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 61AD1C433F5 for ; Mon, 6 Sep 2021 10:43:23 +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 24ED060EBA for ; Mon, 6 Sep 2021 10:43:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 24ED060EBA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.179615.325970 (Exim 4.92) (envelope-from ) id 1mNC5p-0004ls-Ce; Mon, 06 Sep 2021 10:43:13 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 179615.325970; Mon, 06 Sep 2021 10:43:13 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mNC5p-0004ll-9k; Mon, 06 Sep 2021 10:43:13 +0000 Received: by outflank-mailman (input) for mailman id 179615; Mon, 06 Sep 2021 10:43:12 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mNC5o-0004lf-KT for xen-devel@lists.xenproject.org; Mon, 06 Sep 2021 10:43:12 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mNC5m-0001kT-Vu; Mon, 06 Sep 2021 10:43:10 +0000 Received: from 54-240-197-236.amazon.com ([54.240.197.236] helo=a483e7b01a66.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1mNC5m-0005x2-PP; Mon, 06 Sep 2021 10:43:10 +0000 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" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject; bh=ZCb0AKomNjh90Gk0tOHoLBirjLw+JK+7N6jSubaVZtI=; b=GTbTw7PclL7DoJ7msE18HSBIsh jZ4zTIk4BIazeIcE7Y+/WF8agIZibSSD0qhSLNtiQX3qAoQQzGagnIU7Ovk6ZPz5oFx5+r28taVjS fw3+rOD1Uzv3tihlqagvfii8YiXvRUVqfVdoEWQSNvavp9zD5Ti0lA2ZzQYTmCp+IGyM=; Subject: Re: [PATCH v3 1/4] public: Add page related definitions for accessing guests memory To: Jan Beulich , Costin Lupu Cc: Stefano Stabellini , Volodymyr Babchuk , Andrew Cooper , George Dunlap , Ian Jackson , Wei Liu , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , xen-devel@lists.xenproject.org References: <22031be8466bb18d1dd891481ccc67d8c2b2dd55.1629737453.git.costin.lupu@cs.pub.ro> From: Julien Grall Message-ID: <9a5e836c-32ae-50e2-1091-086a40beb4b2@xen.org> Date: Mon, 6 Sep 2021 11:43:08 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Hi, On 24/08/2021 07:11, Jan Beulich wrote: > On 23.08.2021 19:02, Costin Lupu wrote: >> These changes introduce the page related definitions needed for mapping and >> accessing guests memory. These values are intended to be used by any toolstack >> component that needs to map guests memory. Until now, the values were defined >> by the xenctrl.h header, therefore whenever a component had to use them it also >> had to add a dependency for the xenctrl library. >> >> This patch also introduces xen_mk_long() macrodefinition for defining long >> constants both for C and assembler code. >> >> Signed-off-by: Costin Lupu > > x86 part: > Acked-by: Jan Beulich > > This extends to the common parts only if the Arm side gets an ack, For Arm: Acked-by: Julien Grall Cheers, > since - as said before - there you're treating use of one unstable > interface (libxc) for another (the ABI) in supposedly stable > libraries, or - if the ABI is to be stable despite being exposed > to the tool stack only - you make it impossible to make the page > size variable down the road. > > Just yesterday we've been (internally) talking about the similar > "maximum vCPU-s" aspect: This shouldn't be taken directly from the > ABI by tool stacks, as imo we ought to allow the upper bounds to > be configurable in the hypervisor (with the present limits merely > becoming limits of what can be configured). This would similarly > require a library function (or two, as HVM and PV limits are > likely different). I wonder whether we shouldn't have a stable > library providing functions to retrieve such limits. Initially the > library would return constants, short of the hypervisor providing > the needed data. > > Jan > -- Julien Grall