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_PATCH, 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 28E6DC2BB48 for ; Tue, 8 Dec 2020 09:13:02 +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 E1E8623A7F for ; Tue, 8 Dec 2020 09:13:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E1E8623A7F 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.47242.83638 (Exim 4.92) (envelope-from ) id 1kmZ37-0005G3-2F; Tue, 08 Dec 2020 09:12:45 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 47242.83638; Tue, 08 Dec 2020 09:12:45 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kmZ36-0005Fw-VL; Tue, 08 Dec 2020 09:12:44 +0000 Received: by outflank-mailman (input) for mailman id 47242; Tue, 08 Dec 2020 09:12:43 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kmZ35-0005Fr-4e for xen-devel@lists.xenproject.org; Tue, 08 Dec 2020 09:12:43 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 2ad26ae0-c35f-421b-9730-9806fc593c14; Tue, 08 Dec 2020 09:12:42 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6AB6CB04C; Tue, 8 Dec 2020 09:12:41 +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: 2ad26ae0-c35f-421b-9730-9806fc593c14 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=1607418761; 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=Wji7cVr3E4ewzf0/ekPSVYyJD48uMGTKrk3JbT5PmOM=; b=VItoo7KwBUcpXcHTZrylVcMEStb4pjIBDlKbmUj/5oY/x2/doF4+BGOb/oOad6RXqLji+F gM1U932Y+smoMwjYcMn0HUu8RvYVRlPw1GcHxlDWsJ+AZxsLh2bauyFgYnc5e8Y41mC0en dWiLtFHrUr8cfcOdCcy2BESvRp1N0HU= Subject: Re: [RFC] design: design doc for 1:1 direct-map To: Julien Grall Cc: Bertrand.Marquis@arm.com, Kaly.Xin@arm.com, Wei.Chen@arm.com, nd@arm.com, Paul Durrant , famzheng@amazon.com, Penny Zheng , xen-devel@lists.xenproject.org, sstabellini@kernel.org References: <20201208052113.1641514-1-penny.zheng@arm.com> <6731d0c1-37df-ade8-7b77-d1032c326111@xen.org> From: Jan Beulich Message-ID: Date: Tue, 8 Dec 2020 10:12:41 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: <6731d0c1-37df-ade8-7b77-d1032c326111@xen.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 08.12.2020 10:07, Julien Grall wrote: > On 08/12/2020 05:21, Penny Zheng wrote: >> --- /dev/null >> +++ b/docs/designs/1_1_direct-map.md >> @@ -0,0 +1,87 @@ >> +# Preface >> + >> +The document is an early draft for direct-map memory map >> +(`guest physical == physical`) of domUs. And right now, it constrains to ARM > > s/constrains/limited/ > > Aside the interface to the user, you should be able to re-use the same > code on x86. Note that because the memory layout on x86 is fixed (always > starting at 0), you would only be able to have only one direct-mapped > domain. Even one seems challenging, if it's truly meant to have all of the domain's memory direct-mapped: The use of space in the first Mb is different between host and guest. Jan