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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 7D9F7D2ED1F for ; Tue, 20 Jan 2026 15:33:39 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1209155.1521265 (Exim 4.92) (envelope-from ) id 1viDjM-0001Xn-MV; Tue, 20 Jan 2026 15:33:20 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1209155.1521265; Tue, 20 Jan 2026 15:33:20 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1viDjM-0001Xg-JT; Tue, 20 Jan 2026 15:33:20 +0000 Received: by outflank-mailman (input) for mailman id 1209155; Tue, 20 Jan 2026 15:33:19 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1viDjL-0001Xa-5i for xen-devel@lists.xenproject.org; Tue, 20 Jan 2026 15:33:19 +0000 Received: from CH4PR04CU002.outbound.protection.outlook.com (mail-northcentralusazlp170130007.outbound.protection.outlook.com [2a01:111:f403:c105::7]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 578db704-f615-11f0-b15e-2bf370ae4941; Tue, 20 Jan 2026 16:33:18 +0100 (CET) Received: from CH7PR03MB7860.namprd03.prod.outlook.com (2603:10b6:610:24e::14) by SN7PR03MB7058.namprd03.prod.outlook.com (2603:10b6:806:353::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9520.12; Tue, 20 Jan 2026 15:33:10 +0000 Received: from CH7PR03MB7860.namprd03.prod.outlook.com ([fe80::f5ba:35df:1c9f:b343]) by CH7PR03MB7860.namprd03.prod.outlook.com ([fe80::f5ba:35df:1c9f:b343%4]) with mapi id 15.20.9520.005; Tue, 20 Jan 2026 15:33:10 +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" X-Inumbo-ID: 578db704-f615-11f0-b15e-2bf370ae4941 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=achTzX66ko6AXWtAetp9orG8EnuuGZmRZsWhN9naL6ZX9wH52aPnhLfAioF29V2qt5w4pS6YzVknA5nPBxVshNVAil6EwNcQa0DC7ewQswNP9d9UWCXQSCVpF2xZNIFE1LO78lU0aMpunAffDcSckwtpZS0OyDATIYZKgDcwz74rZluxeUlHs6ktubJnJqdoBo0qlwmsXeiltfR8/UTDWjsGvtiFkdeo0tF17kIvktK1JoJL2SCAuzOm1F0DEhkVusxseastOmPFZmktEsE5MwxSqEGL3XGaTwVxIO7ojyCZdXx4/nkdHXOWlH6ovJpfFZ9ZQyrtGDq4dA0GvzSK0Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=Dy496zTH/Lr4IN5cUi/7GmFfoC/qmaNauHa9lWQdFw0=; b=phWZQY3SPcqi/iuz7yWSFiLwEcMqYBmACsQGsg3/se6w2VtV4liS0gvc2p+FBzCYMsbJldIVOY3NKfYRxWVgBKaASeNI6DTK5tsSAtuwZONAO8FVDcxEop9JfArgbPnRnAO/U2ygFMQd8+qyHFc3JYOEaWikJgC469ei5gjtWmmw/aMykaiDAH2KEVWrPF/2vs7gY/almFR+VG40s+SNEP3HcxB33WQYqdOfk/jZ2qAvAh7GOpkwwK7EWJ0i/BPtD+8oJTL61HiLQj65z1RvivnJnQtIAr2G7JV17KV1tgHyRQuhLd07kyxEJzvHw521AdxmYZj0JKWPrFQha9qWgA== 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.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=Dy496zTH/Lr4IN5cUi/7GmFfoC/qmaNauHa9lWQdFw0=; b=eKPhrHT7zImeIkg60+RP7GPOhEDCDWshKT3BY+r3WvZ3WkIsW6HIdFr7EqU9X+X0dBFvzv4D3E309Ediea5DtnDTWrSS37HbqOASLHBOtg4HLCLNVSE9G90xswx+3nRlLEuR2SjigO9JdVAb64GCnwuTfGWwOsE9xyUEMizKb3Y= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=citrix.com; Date: Tue, 20 Jan 2026 16:33:07 +0100 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: xen-devel@lists.xenproject.org Cc: linux-kernel@vger.kernel.org, James Dingwall , Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko Subject: Re: [PATCH] Partial revert "x86/xen: fix balloon target initialization for PVH dom0" Message-ID: References: <20260120140648.25977-1-roger.pau@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260120140648.25977-1-roger.pau@citrix.com> X-ClientProxiedBy: MR1P264CA0218.FRAP264.PROD.OUTLOOK.COM (2603:10a6:501:56::11) To CH7PR03MB7860.namprd03.prod.outlook.com (2603:10b6:610:24e::14) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH7PR03MB7860:EE_|SN7PR03MB7058:EE_ X-MS-Office365-Filtering-Correlation-Id: d0295c90-99ac-4517-294d-08de583937d2 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?Sy9ZUHJNS1FreVRUbFJ5Q3JiQmtHUHRNekFJTUFxQWVBR21Ga2ZXVFNVRXBi?= =?utf-8?B?SSs0aEdFcHhQeXQwUU9talhReHZ0dmZsbWNlSnVFNGRXUHAzQmpDaUVUMGpE?= =?utf-8?B?MW9JbFVDZG9EYkthK0hQMzU4ZVB0ZUIrR1pGcFR2ejVjR1BMUTQ4U09qNE0z?= =?utf-8?B?bW9PWjVpRHhLY2N1Qm5nVjFUL0tKaUtsckxHZS9oYnRHQTZZbkNtbUJzb1pT?= =?utf-8?B?SGFQVlo1UkFoa0xGVWh3U1E1K216UnZyYXREazVpYmIvb1VDdEJFNkFVMkdG?= =?utf-8?B?S1dEYTl6bGlsRldpeDdPN2VBOC9iN0JMbkZoKy9qRHdBbnpPMmhCT3I2QWVm?= =?utf-8?B?Q3E1UTJsOC90aXFtS29HaGYwbVFFRVErS0JSTU4yT2FkOTRJK2IwellwVXRK?= =?utf-8?B?RXY3cWM4Y1AxdnVqbHdjZDdNdEZ0R3hzeTNlazdkM0ZvSkhFamVqaXNpdlBo?= =?utf-8?B?WC9CY2NTSTlCdWY2VE13NTdONGF4U3gxR1RaWHR2VVRFMVpHRFBweHdRMDdz?= =?utf-8?B?dFlxUENmNVFjM2hyR1NvNmp2a201cjJtMTJrdU16VXRIM0RsZEtFVXBUWUlL?= =?utf-8?B?RXFmWFFIMDFxVmRwb1pIaUxIa09lUmdIUTlxUExLOWdIdVNHdFA4VmNPQnlw?= =?utf-8?B?enRPdVhja2ZzMUdUM1JvYkV5LzFsb0hoT3JlQ0lVYXdOR2FCdGd5eUdhSm1F?= =?utf-8?B?NjJPdmUvaTRNUlh5VldNSXJ4STI1Nk1HOFRyTXNhcnJXQVRybW5BejVBN0VC?= =?utf-8?B?YWEwNkw5Szk0STlTQ1JzcGl5QkNCRFo4YTk3cVM3dk5DUmZDbTZDK1VPQWpP?= =?utf-8?B?RlVlTUVvbitoSkRzUE80NGFyQzZheHhpRWhnRjh3U3ZDb2kwWndOUVBISlFR?= =?utf-8?B?aDM4aXMrMExoMDZPNTYvZ1gyNjdqdFYreU94RDBWZk9YU0ZWd0dXb2ZySGZw?= =?utf-8?B?RUFyU0VXdFVTL1ZYK3lsYXRSb1dSeWZnSFZRdEtjUkpZM0FteENaV054Skg2?= =?utf-8?B?L3RVNUVEbzJQMWtSQ1M0QTdNUFlkMjJaZVVOdUJmd0MwbG1qZmxxSEtkOGoz?= =?utf-8?B?MkRUeUx4YTh2UmRtZGgrQm9MT0N0bVhNMjVOMEtvVVJsUzFpU1hBRDcwL0pI?= =?utf-8?B?Z21jU1hJZndVVnI4SXd5L0xiS1V5cVdzb01Uc2pMKzhPYnFkSDFhNVYrL3hn?= =?utf-8?B?VWFPY0pCbzlVRFR5K3R4ODg1aURmcVF6YkhUNGRoZm9LR3hzanRRVHFHMjI5?= =?utf-8?B?N294NXFlRDcxZkpTcDFzZnltV3hBUE5SZmZnNGZEamJGTndWamFmRXRpL3ZQ?= =?utf-8?B?VVNpS1F1b0hNTnIvTm5adng1cW9sV1U3MlNWUXI0VDkzNW5QbmRyYXlBOWh6?= =?utf-8?B?UFFlWXpwNENrUDNhU0JuL2JsNWhsVDNCOHNDTElwZlF5bmVxM0FGVHRmMFRw?= =?utf-8?B?STh0RkxpeEhSekdkNG5yaVJlQ0xEdjFGZHdVSlRUU1NlbHY4UlZsSmhPUTVL?= =?utf-8?B?QXdiTjZsSEhIMzNOc2lJZ3hST3pHUVpoRjdJVFJ0cW5JdlN3a3JDaXdTOXNC?= =?utf-8?B?c0srejBFNXo1NktoaHdGL0NZQktTVlZqNFE2aG8ycGxlR0FHZnBFeklXUHRC?= =?utf-8?B?WGtaeXZUc0hjWk5JSGszZk9nTFExODlDYnhOSXM2dEZDY3Ixdk1SWjJ0RWVw?= =?utf-8?B?eGFGaU9FTHhxNHZ6VHMvK2l2Q3Bhakt4QW5OYzUzVXUrSTFLZFJkQVZnS2Er?= =?utf-8?B?ZXNUamt0aUlhY2VNR1NoYW5kcHRZYlVmT3pkRjdxbnZxOStSZ01DbUdrTWt5?= =?utf-8?B?dS90VU95V0FXc3pDZFpoR3JuV0dtOFkrK3dPUlRYL2NEV09jUXp3NTdIbVVL?= =?utf-8?B?RTVqZjFLTDdBVGNmeFdXWitpNjN5aVdUMGR5MGRFOWFPRXZZcW40dVA3TzNV?= =?utf-8?B?cjlrL1FLbDlrUGxsY2Y1UC9IYUpwcVQ4M3gySU1GVmNnNnY4bU96VHlMRnZq?= =?utf-8?B?Z0wrMmc5b1hMakVrTWgrYkFYNzJHMjFwekVvQjV3ckNkMUl3NnJlb3c3a1pX?= =?utf-8?B?dUVMd3I0TTdsUEdoaDBDWS9SL0Q5TnRIaTN6VFRYRHlqSmIwYmhwcEI4Zk9L?= =?utf-8?Q?P4g4=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH7PR03MB7860.namprd03.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?NTY2OU0xcnUzOWh3WWkwMkRiSGF5TGFqYjZRWW4xbUFqTHhNYVJCeEdaZWZR?= =?utf-8?B?VmsrcCtvdk5nUkR1Y0lTamFJWUlIaUpOOGtKeUtmVU1XejJobnVnaTZ4b3l5?= =?utf-8?B?dkJqODFzV2Y0QnNwdGpycE5sOWwzK1laQTArMmlzcDFqT09JUjdFRkZUcEFi?= =?utf-8?B?MWIvT3R5S0pzTFVxd3NFOEl1aUNGUGpsdE9JTFByWVNjWXZLeVZkeUp4RGxW?= =?utf-8?B?eWgxN29heDdUMTZicURaVTlMdWNkbFdlL054SzB2eEx1Wld3QURMWXJLbHZV?= =?utf-8?B?bHpyRHJQYVRtc3RlU2NjRGhYS2htWVMzWTNUa2tyQzlLZFlrSUhYcktINHFT?= =?utf-8?B?ZzJLK2hXRDFqYjhlR0txVVNHM05RQ1RoQ1hKMUZKZHVEUTVwdEJiM3p3MEFy?= =?utf-8?B?UHRJb2dhS0tKV1J0THBDY3ZWdmJ2UHlzNnZlakt5WU5BWjRaVnBXaGFWdE4x?= =?utf-8?B?elZ1Z2R6d1BGaW5vUmorQXVyQ1ZNaWtMT1o5aU1tazFKNiswK2F4Um04c3Nu?= =?utf-8?B?aGlTS2pZQWxGU1lpMk9UMDdlN2xQRURYZXBEY0paelhJU2xIRU4zalRoL010?= =?utf-8?B?bHdwajMxbVhwOU10d2hWTkpDdFVVenR6Tksvckw1cnBXNnBVYUpZQU9IenVE?= =?utf-8?B?NjJ3dThmc3RWYk55bU9HR3RmUXlvZWxrSlNFcXJEb2tZTlB1SnFXOGRYTXJU?= =?utf-8?B?WTlsNURDY1hldTF4UWFGcmo3ZDJ1d0JoTVJhQjBUaURRUEhNUkNObmhDQXc0?= =?utf-8?B?a2UrQ25KK1ErOThtV3F1cTlESTlySUNDa01TaER2c2lFdWVuVkNmNWwrYmNZ?= =?utf-8?B?dTBMMld3eUJleTFXWWJBRTlXY016SE51bFczcTExSVA0cllGd3NlemNmYUYx?= =?utf-8?B?MW1HTTl5TC9ESzhQQTFNYlNNeG05Mkt2OWtSN2NvcGdyL2JoRVhwVmJLZXpl?= =?utf-8?B?NS9MK3RYR1ZYOUg4RmpqZHJqbGN1K0xtUnMrUG1HMFpwSk5UcjVOd2hBd3Ns?= =?utf-8?B?bXVONmY2dm5iQTdmbk93Vk9XZVJneWxIbEI4RnZ6Yzg4aTJub0JlTWtYVzJU?= =?utf-8?B?dW5iMlVvR2JqblREVkt5SmJKK1ptVGRJZzZRYSt3OWlDd0E2TWNzci9jSVFN?= =?utf-8?B?a2hlYUJrMENQTUVFN2xzOU05WndBTDlRU0tpc043aHFkL3JLZlZuOW82VE5K?= =?utf-8?B?VDJBT2E1L0RaeDhkbmgvTVZXVXpDS2kzYW1Sc2Q3Y2gxeHJMVVBxcjZEUTRP?= =?utf-8?B?U2pqQjM1dVJYdTBXVko2UEVzTnVYY2Z4VjJaNUJIdnN2L0Exb2RIOFpzNnBm?= =?utf-8?B?ZGtaNWxJN1UvYXRkRVQwVStQWUV3VFdMMHJ3Z20xYzRzM3dabGU3Y21XZHBH?= =?utf-8?B?aTFXbS9WYkQ0QjJ2cEY5dFNoMFBMUmhaZS9Ldmwxa1kyYkgvcmtNYmRBc2xa?= =?utf-8?B?WVk0ZndzMjBvcE8rUnk1Zzgxc3BLc2Z3elJDM2hrSjl0WUlxMVNscjczcDV2?= =?utf-8?B?STJHdm16UnA0dmpJc3ZzRFNsbjE4WjJldmJtWXBNREtyWGI0cTd2ZFFXQU1M?= =?utf-8?B?SDRBQVJISU53cW1wczR5WnNjWXU1Um1VdGxra3VzWmpUZTlsVzI3dmFhMTVx?= =?utf-8?B?WnBQZGNEUVR5TnM0ajA4Z1FWUUdwQzRGLzZoS2huQVRzMmVPUVgySHBvU1B3?= =?utf-8?B?VWhsSFlWSjVpT0VEWEF2N243dGJlMEQ0K2d6SWsveEZPT1psbWRuZkhxbVNz?= =?utf-8?B?SVNMTXBWRlZYR25zU3ZwVjNYbDFkZHErMGxVc0IyMloyMlV5V3o3b2RPay93?= =?utf-8?B?LzVXL1ZqZWNTWkxoZERKRGVQZzZ6T3dVT2JGVHcreGJTR2FxbjJlaS9WRFNQ?= =?utf-8?B?QWxwLzJCb0dXU2RMczNjZG9QWFZFaFB5OVBFbHpOUyttWWZxcXBTVk00QVdu?= =?utf-8?B?dS9SbThXV2ZkOGdSUHg1UDZUdjMvdXM1TGlpajNMbjBZZmhuYWhBL3RzcmlX?= =?utf-8?B?L1VYMVk3c2ZZNHBHRVZsNVR5V3RkbUZld25ORFowMlFZZXZpazBKUUdOc3Ji?= =?utf-8?B?TGZjaENWNEk4Zi9zK1hPcXJJU1BXQ3VPVitwTFl3aldZRTFkWGlsTmt6RWtH?= =?utf-8?B?ZlREOFJXMWU2Y3VQcDBnNXMyTEtkcllVaTk4V3Z5OGRqWVJXM2czQlNPVG9w?= =?utf-8?B?bE4vaG1pQmhzbTYxekM5UDZNRlZmQ01uRk10LzF2NkZqSU9KNERneFZ2RFMv?= =?utf-8?B?WmxkbHAzUEdBalc4eWlGM3dzNHBBUVNwVTFuRnJMbUlnMDRQMFNBL2ZjZGo5?= =?utf-8?B?Z21hMzd2ZFI4WmtMS240amtVTC9TVXdlYTVodEJMMUtBbXBsNmdVQT09?= X-OriginatorOrg: citrix.com X-MS-Exchange-CrossTenant-Network-Message-Id: d0295c90-99ac-4517-294d-08de583937d2 X-MS-Exchange-CrossTenant-AuthSource: CH7PR03MB7860.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jan 2026 15:33:10.7041 (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: j4tm7rNxoZm0hzxcxjgNoQfWSIDAc+F236W/rnXoxNcFh8ziDRSpIBUQYsbSLTo67G+uCYkwebwahNGKe0+mGw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR03MB7058 On Tue, Jan 20, 2026 at 03:06:47PM +0100, Roger Pau Monne wrote: > This partially reverts commit 87af633689ce16ddb166c80f32b120e50b1295de so > the current memory target for PV guests is still fetched from > start_info->nr_pages, which matches exactly what the toolstack sets the > initial memory target to. > > Using get_num_physpages() is possible on PV also, but needs adjusting to > take into account the ISA hole and the PFN at 0 not considered usable > memory depite being populated, and hence would need extra adjustments. > Instead of carrying those extra adjustments switch back to the previous > code. That leaves Linux with a difference in how current memory target is > obtained for HVM vs PV, but that's better than adding extra logic just for > PV. > > Also, for HVM the target is not (and has never been) accurately calculated, > as in that case part of what starts as guest memory is reused by hvmloader > and possibly other firmware to store ACPI tables and similar firmware > information, thus the memory is no longer being reported as RAM in the > memory map. > While kind of obvious, I guess this needs a: Fixes: 87af633689ce ("x86/xen: fix balloon target initialization for PVH dom0") So it doesn't fall through the cracks for backports. Thanks, Roger.