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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2ACDEC433B4 for ; Wed, 19 May 2021 20:19:45 +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 CF66D611AD for ; Wed, 19 May 2021 20:19:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF66D611AD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org 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.130414.244337 (Exim 4.92) (envelope-from ) id 1ljSf9-0006jZ-6u; Wed, 19 May 2021 20:19:27 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 130414.244337; Wed, 19 May 2021 20:19:27 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ljSf9-0006jS-3o; Wed, 19 May 2021 20:19:27 +0000 Received: by outflank-mailman (input) for mailman id 130414; Wed, 19 May 2021 20:19:25 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ljSf7-0006jM-On for xen-devel@lists.xenproject.org; Wed, 19 May 2021 20:19:25 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ljSf7-0001cP-Ie; Wed, 19 May 2021 20:19:25 +0000 Received: from [54.239.6.185] (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 1ljSf7-0004Dg-CS; Wed, 19 May 2021 20:19:25 +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=+Rnvnhd/0HT/XthA1LClHFuxX5pf6YhLMjjVwgpQ0co=; b=YpVT4QwcXe0365iutBgIGrlqcf jgXGqPCJhAYoPc+FcbOqSMGzl/ISco1JTKIAnoix7kmMMAqHzVFwOLvpbybQrB7M3RRHEBD6kzJBk kqNk1CM5FN9rKfnfifaJS16ygU4HjQ4jcC2N8w21KUcOcLoUNNzy+QyIP+UkFz3PV6CI=; Subject: Re: Hand over of the Xen shared info page To: Anastasiia Lukianenko , "xen-devel@lists.xenproject.org" Cc: Andrii Chepurnyi , Oleksandr Andrushchenko , Stefano Stabellini References: <64bc6ab6ec387acebb40c1b4786dfda1050f9d50.camel@epam.com> <8ff05bdf-a6c4-6b14-b39c-7d9b3bb9d279@xen.org> <1db54c363eae22613280e7181805abee396fe5e9.camel@epam.com> From: Julien Grall Message-ID: <8d1ecf6c-a0d1-d9bc-5daf-d02a34fff1e6@xen.org> Date: Wed, 19 May 2021 21:19:23 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: <1db54c363eae22613280e7181805abee396fe5e9.camel@epam.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit On 14/05/2021 10:50, Anastasiia Lukianenko wrote: > Hi Julien! Hello, > On Thu, 2021-05-13 at 09:37 +0100, Julien Grall wrote: >> >> On 13/05/2021 09:03, Anastasiia Lukianenko wrote: >> The alternative is for U-boot to go through the DT and infer which >> regions are free (IOW any region not described). > > Thank you for interest in the problem and advice on how to solve it. > Could you please clarify how we could find free regions using DT in U- > boot? I don't know U-boot code, so I can't tell whether what I suggest would work. In theory, the device-tree should described every region allocated in address space. So if you parse the device-tree and create a list (or any datastructure) with the regions, then any range not present in the list would be free region you could use. However, I realized a few days ago that the magic pages are not described in the DT. We probably want to fix it by marking the page as "reserved" or create a specific bindings. So you will need a specific quirk for them. I have posted some more idea a separate thread [1] related to FreeBSD support for Arm. Cheers, [1] https://lore.kernel.org/xen-devel/f7360dac-5d83-733b-7ec5-c73d4dc0350d@xen.org/ -- Julien Grall