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,URIBL_BLOCKED, 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 85D86C433DB for ; Mon, 25 Jan 2021 18:26:18 +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 0A7B322D58 for ; Mon, 25 Jan 2021 18:26:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0A7B322D58 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.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.74261.133438 (Exim 4.92) (envelope-from ) id 1l46Yu-0004FN-Qj; Mon, 25 Jan 2021 18:26:04 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 74261.133438; Mon, 25 Jan 2021 18:26:04 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l46Yu-0004FG-N8; Mon, 25 Jan 2021 18:26:04 +0000 Received: by outflank-mailman (input) for mailman id 74261; Mon, 25 Jan 2021 18:26:03 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l46Yt-0004FB-Rm for xen-devel@lists.xenproject.org; Mon, 25 Jan 2021 18:26:03 +0000 Received: from esa3.hc3370-68.iphmx.com (unknown [216.71.145.155]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 8c8863a5-4aa8-43b0-8a1c-48e80ab97f0c; Mon, 25 Jan 2021 18:26:02 +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: 8c8863a5-4aa8-43b0-8a1c-48e80ab97f0c DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1611599162; h=subject:to:cc:references:from:message-id:date: in-reply-to:content-transfer-encoding:mime-version; bh=9xIkNY0HRWE+K4v6o0KModEtgF7aWr5T+ezRogdXzh0=; b=Zp9l4YLeUZ4QGrtIfDEdi7aBW7iMjLKDKx1ClxpgnqnAbGwsXNQeM6RY WzRJLFSy5xP9O4R9Uum7IGY2ZEAHXXrt7EvOf53d/8xhoGvoayiSwZs8f czmWTgpMltqV3lJIaOUg48VwGqtY7MnsLysemnVJLr8d9YbNQ4U7muGYR Y=; Authentication-Results: esa3.hc3370-68.iphmx.com; dkim=pass (signature verified) header.i=@citrix.onmicrosoft.com IronPort-SDR: R+0svzSbxlYlscoq9dgH6nvl9Tx0o5qEOxLz3Nn5GYlFVVP7WXWt4FKabw1zxAUSvOnH9Uuruk CLc5AxVGpj25xEiwl4EPo0KmnBg0zqgXs1pbjRDYiccA7pPCG6qzJ9E5hcUWTbwVv/Ws0P0OJh CTo24GoT+FfsjyWAReEGJ5yWgXEG93jJC4IxWQXFK6JlWPrvE468ET3wWzlxxpYBsQIYcIS8PN Fx5LKoOSAE0W0ADoT8awLcZDAM/ImtRR09IqmpBWOLhyQVdgN9H33r0ejWevIokXNnufivhAP4 nQg= X-SBRS: 5.2 X-MesageID: 35807837 X-Ironport-Server: esa3.hc3370-68.iphmx.com X-Remote-IP: 162.221.156.83 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.79,374,1602561600"; d="scan'208";a="35807837" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=DoNNMF3Rq0NCUJDqTXihkYgpnjJKRo07yHte4ag/K5X1roL9l3oUS1gKLWjcn95DG4eS1Uko5Kf/4fDpj4UUPwRlGOQRSsCurNDRAvkPH4hMsnPznj7XvQMF7o/K7MKXR7MqKmaxmCjYHz7iDgpf9jNt/zyS1le4a0NbP6DOY+8RIa7OAg4dA0W7IEZXv5+Ir4jOHcG1d9OAYF6H2iEMG3qblisUH3I1a+E1HThO7JuHjfzJDi43rCo0sJKibMDbES3+TBMouuNVk42r84TEdhNRgPfPHAyYJLZwvSP+U7qT+c5AtAxUgn0IDhsnrYwilVB9nzfnrzdaNUQMIxDlCg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=WnHdw0xNeGjThfKqWSSik4ffoouihnLdjf0gj76VPvU=; b=QNU+CNvgNkLymsAxzp/ZLHeDnozHIlm54RHIcaQxLD4YAyWIYhAR5q6wLUkxAgyMQ9VjJqCihi58XZ86WehBd/Pz4lV6eJT8qLFmEpsaJd7VJz8wausbkMwyuvrXl4HT4XXaoKYWDxfII5Pq5ncyE5yN6vLT5F949eruwuPU3AIU0d8FeTV/b0pBO3Mvt6WVOM3jqX5A4MnqTW4AA5jr+YNNyU75PfcFLjntJapMxyxv4XCIjkVo7tyhgDWDMUSInfGStwPdfqj8cO6fpI23G2xU/Tur/tRxLOy0xtilPuO6F7+PxrZPQ/D1gfvYC06ufAvxJgfvno4efkTIs5nhAw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.onmicrosoft.com; s=selector2-citrix-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=WnHdw0xNeGjThfKqWSSik4ffoouihnLdjf0gj76VPvU=; b=VaQo6mdQiJ6RrPwgbUy98O1mYMW9pGROuKzmurZJvAXih7YkbEcV9KtSCrzG0isexApo4ZxeJ2eFWeyflgLl31EdHTCNnp8sl0vDgqw24457QQfJ19RGfNo5KndwdQRZ5P8xN8oFlWsQpW4K8ETVEUBMEM80cmfFJVplL+MuyVc= Subject: Re: [PATCH v10 01/11] docs / include: introduce a new framework for 'domain context' records To: Jan Beulich , Paul Durrant CC: , Paul Durrant , George Dunlap , Ian Jackson , Julien Grall , Stefano Stabellini , Wei Liu , Volodymyr Babchuk , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= References: <20201008185735.29875-1-paul@xen.org> <20201008185735.29875-2-paul@xen.org> <4f0b7537-807c-54cc-0c0b-23e30e833f45@suse.com> From: Andrew Cooper Message-ID: <2f370df1-dba4-ccf5-b06c-ce97916e8858@citrix.com> Date: Mon, 25 Jan 2021 18:25:50 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 In-Reply-To: <4f0b7537-807c-54cc-0c0b-23e30e833f45@suse.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-GB X-ClientProxiedBy: LO4P123CA0233.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:1a6::22) To BYAPR03MB4728.namprd03.prod.outlook.com (2603:10b6:a03:13a::24) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: b0b4342e-717a-4588-8502-08d8c15ea8ab X-MS-TrafficTypeDiagnostic: BYAPR03MB3845: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:10000; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR03MB4728.namprd03.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(346002)(376002)(39860400002)(396003)(136003)(366004)(6486002)(6666004)(66556008)(31686004)(54906003)(83380400001)(2906002)(66476007)(66946007)(8936002)(478600001)(186003)(16576012)(16526019)(316002)(53546011)(4326008)(36756003)(110136005)(107886003)(26005)(86362001)(5660300002)(31696002)(956004)(2616005)(8676002)(45980500001)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?RGtjMk9KYXZuMFVwb2ZMSU55eThtL3QvYm9odWlmU3c0dkVOTWtjeFFoenFH?= =?utf-8?B?Y1BjbkU1dkR5bkM0b1daVXhrbFVXZHVvUFUxRDB3bFF1S2JwczhDczhuTUpU?= =?utf-8?B?WUxRTC95T1lwOTMzZThkU2xqOFpkT2pabW0wVUp5TDF2Unh2aXdUb1ZiMTk3?= =?utf-8?B?eGdGUG5ZZm53K29IQWdvU29BTktCT3kzeVhsS0ZCQzJoUzRrdzVSY29PRVd1?= =?utf-8?B?TW5rMlB5ZnZOMkZreUJYTlMwOWIvcmNPZXB6SnhRQTNDR2lZTzJuNVZLTzFJ?= =?utf-8?B?SnhOTEZNMVFsdHpGVGFBUFNEcS9jV2ZTNzFQcDZjY2ZNOTR4ZVovMDJWdHVy?= =?utf-8?B?a3pld2orZFpZeUZpZi9qc1NiVWMrQkRKeG1FN3J0UXJTYmNnT08xWldkSGll?= =?utf-8?B?Wk1uUGEzU2NOckkzZ3NrWjdIa3VZajEwQjhpWHU0MU5sN0hXOFU4SGxrZjVa?= =?utf-8?B?SmRIbW1zbVVYQWt4Rkdzd2xrNXJTMFM4a0IxR3krUzRKWjJTYnUvN3dEZmcv?= =?utf-8?B?S3Q2OVhlQWxDQ3RBeGJ5QnI2aFRwdkw1dGIwY0Q3RnA3NVlkU0MrdkVOMzNv?= =?utf-8?B?YzQzNlFvbTloeXlWb1NFNEpNVXZLTlcxRVRaVjFmVURWdUFPb3o3c0pEV0xF?= =?utf-8?B?YjF3RzFXL2F5aEZUaHZWVlVDUlhpWVZQM2dXdGRHRXNVNDhPdXAvbXhCUzJ3?= =?utf-8?B?N1BCaU1pOXNXQkdBaDJkcjRZbkZWanpBVHF2aDFzOEpyVXFZbytnUk8ya2Vh?= =?utf-8?B?b3dReEUvKzhybTNuek44S0s4OXdXVkF2MnFQREZzOTVSODV0K1pHL29CTWZ4?= =?utf-8?B?NitocHZWdEkxbUduUWlwUnJvc2l3QTBuOHpoTEkwR0pSbFZJaGdHaktIRmVh?= =?utf-8?B?OXZSSUQ1bDJjcGpNaWZrb1hadHljOGRDM1hLMVJkU1hqVU9ZZFRZeEkwVnFW?= =?utf-8?B?OS9QWnIyMWVaTWlaVitxUThvVjRIMnhqZGFoQStSVWxvZVZNZWJVUlB2RE5h?= =?utf-8?B?NkpOZWNYK01IZm5vY3RWN3lYb0lWUE02cmpQaDFGSHJRdEVsZEVScGdyZzkv?= =?utf-8?B?K1NkRU4rdjliN0JobHpSSFEwNG9oNVo2eDRQVVd1SERyQ1ljbW1STSt4OTVP?= =?utf-8?B?aHAyWUtvMzNBVkFvK0FPRGNKUkhSK0xHNHB3RkNOd1VWSEJIeU05VDVMMEVY?= =?utf-8?B?ZFpVUWRqdXJDUEJLMWFvM3NsMDBxa09McG9raTBXUmQ2dFdZWTNUNEQrYUZw?= =?utf-8?B?SVBDMHBjRklNeGZXR29lYXNNWHB3TU9LcXZ4ZjUxU1ZHb1hncXJYalVRRysz?= =?utf-8?Q?sX+w4AkIkSQJuPLCBGp0S8MIp8Vmt7fQtU?= X-MS-Exchange-CrossTenant-Network-Message-Id: b0b4342e-717a-4588-8502-08d8c15ea8ab X-MS-Exchange-CrossTenant-AuthSource: BYAPR03MB4728.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Jan 2021 18:25:57.5124 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 335836de-42ef-43a2-b145-348c2ee9ca5b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: tpUJeD9yc9HCPRufu7jVt1H5768byV5bW3uB0qLda2pDw7PlBHqOi9FpyFAAMnsche6eRRU4DrHXcrK3hC0RMLu72cLIjlj5UBRW5/kN28s= X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR03MB3845 X-OriginatorOrg: citrix.com On 19/10/2020 14:46, Jan Beulich wrote: > On 08.10.2020 20:57, Paul Durrant wrote: >> --- /dev/null >> +++ b/xen/include/public/save.h >> @@ -0,0 +1,66 @@ >> +/* >> + * save.h >> + * >> + * Structure definitions for common PV/HVM domain state that is held by Xen. >> + * >> + * Copyright Amazon.com Inc. or its affiliates. >> + * >> + * Permission is hereby granted, free of charge, to any person obtaining a copy >> + * of this software and associated documentation files (the "Software"), to >> + * deal in the Software without restriction, including without limitation the >> + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or >> + * sell copies of the Software, and to permit persons to whom the Software is >> + * furnished to do so, subject to the following conditions: >> + * >> + * The above copyright notice and this permission notice shall be included in >> + * all copies or substantial portions of the Software. >> + * >> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR >> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, >> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE >> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER >> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING >> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER >> + * DEALINGS IN THE SOFTWARE. >> + */ >> + >> +#ifndef XEN_PUBLIC_SAVE_H >> +#define XEN_PUBLIC_SAVE_H >> + >> +#if defined(__XEN__) || defined(__XEN_TOOLS__) >> + >> +#include "xen.h" >> + >> +/* >> + * C structures for the Domain Context v1 format. >> + * See docs/specs/domain-context.md >> + */ >> + >> +struct domain_context_record { >> + uint32_t type; >> + uint32_t instance; >> + uint64_t length; > Should this be uint64_aligned_t, such that alignof() will > produce consistent values regardless of bitness of the invoking > domain? Does it matter?  Its just a bitstream, and can appear in the migration fd at any arbitrary alignment. What matters is that the structure is aligned appropriately for the bitness of code operating on these fields. Even with the tools ABI fixed to allow a 32-on-64-on-64  toolstack to function, I'm not sure that excess alignment would be appropriate.  Sure - it would be more efficient for 32bit code to align to the 8 byte boundary for the benefit of a 64bit Xen's copy_from_user(), but this alignment happens anyway because of how hypercall buffers work. ~Andrew