From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.52.52 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1793705492; b=ZpCbO1wXBjBxTWHedqUGqvZbIad9Gyd4zA4pKmwhb7x3SqswRc3PzwK+U4p6/xIlo361 SSs/s4XAzhQ47iM/UyZ/cMJYg2bfu1ddwVUqKVNKUPiEZxKvIoWWJI1JDrOspF6WD9KDa vNixUKhf/pI9yleF9ND7G/tiZplhp1vzFQwqx/edaNQDvhrSA5grZL1RMeRQYV9Iu6d/y uWfA7P1hOgrt55FCJK27OusOx7AlUihV0ETDmgKcrJ0WqpU/BqooAk6v7fLDLLByO/938 5t3yrPzCkyuIJ0odrmKjPmMVXuEmmigWSHyXOQGm21bB3sHifKy1hvtTFtlZnjN96cw== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793705492; h=DMARC-Filter:DKIM-Signature:Received:Received:Message-ID:Date: User-Agent:Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding:X-ClientProxiedBy:MIME-Version: X-MS-PublicTrafficType:X-MS-TrafficTypeDiagnostic: X-MS-Office365-Filtering-Correlation-Id:X-MS-Exchange-SenderADCheck: X-MS-Exchange-AntiSpam-Relay:X-Microsoft-Antispam: X-Microsoft-Antispam-Message-Info:X-Forefront-Antispam-Report: X-MS-Exchange-AntiSpam-MessageData-ChunkCount: X-MS-Exchange-AntiSpam-MessageData-0:X-OriginatorOrg: X-MS-Exchange-CrossTenant-Network-Message-Id: X-MS-Exchange-CrossTenant-AuthSource:X-MS-Exchange-CrossTenant-AuthAs: X-MS-Exchange-CrossTenant-OriginalArrivalTime: X-MS-Exchange-CrossTenant-FromEntityHeader: X-MS-Exchange-CrossTenant-Id:X-MS-Exchange-CrossTenant-MailboxType: X-MS-Exchange-CrossTenant-UserPrincipalName: X-MS-Exchange-Transport-CrossTenantHeadersStamped; bh=F2SnKxo6sv4vSn1dXELKrcR20Glkqp4+7/ht9vZM4ow=; b=X4pGoOnv+ES2UZYi7YxercdyERhckF+13nPzr2G4BcR4feAMCX9deEfDV2tyu2kl38no ZIVAMfut23EAkVqQkRJCM/RHFoAR1ehUonfSW+E/i0g1h+sIw69Kkik2PnsFdIhP7d8ac oMdP1IubvAkA5oHvMecw5LBar2ICYNaixI+qyAX2d3X7F3mKtGODOXvut3DHj3xcAjEnR yFPnkPJntZzp8Ii/mzqovaDm2FZvnw4utsErHUDGlvbTgUQE2MICcnG9uIubxTrmdGPZt x7QB0GVWp1ljxsXSE960/jku5a/n6tMAzMU13zId7aAwrNi/P3fq7ANaf4mtmIOWd/Q== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass header.d=amd.com header.i=@amd.com header.a=rsa-sha256 header.s=selector1 header.b=KG2T6QrB; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.52.52 Received: from BL2PR02CU003.outbound.protection.outlook.com (mail-eastusazon11011052.outbound.protection.outlook.com [52.101.52.52]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (secp384r1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 08474606A33F for ; Tue, 3 Nov 2026 11:31:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 08474606A33F Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=amd.com header.i=@amd.com header.a=rsa-sha256 header.s=selector1 header.b=KG2T6QrB ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=u4wz1FuZHEniY87JJWyaDnOlfV/b7wg2YJAY5Si1YQIlMSu9VPgasZa1Mop9RpNycer5ioFKFrk4P8mHR1x9QSIeQUnpjR8FY/AGcuqM0mVS1glhU6XdXxAUgmcbqZzTH+c1szG0wbs/6AE2C1ZkvBOyPag7pKHKqAz0LLm0F1sr2bvM+htZJH/JEjhtdL+BMoFG2etnkuLTWx+kak6TIkhmPmIMCe07vdL/x2Yc5NksMyi82FVHC4xsqm+HVZuCYoBoUqD3gfJaToq6MEMmF0GDSVlStvNVihWoJlUaB6nh6DVZFZHQPhKe43ngWEan2Q5Rat0vV3klWAbhQ4/M4w== 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=F2SnKxo6sv4vSn1dXELKrcR20Glkqp4+7/ht9vZM4ow=; b=bMSTEKAbeDRePXo+cfef3V/GOeJPFsRow7x0OzhVfyAoBnvNdaFxX0rTvBn4n+VvJ+wckTMp/wFRWgHVjDt1F0EYM/8r+yLv9a0uENAu53ga5XgMGX3M7JT/1G92VD73Hv118dodOsopM/8WyHl0gjZAySOle/ktY+2OB6TQeVO2cP654PmsgfeKpRb+xNsMoOb9pljQNczijbrRv35PZZObiQDQqi8VWXS/KR5fZO03Riwwj4YsmHMMVBUpM2aJ4pplpMAJqgrp3G/GXCkB0iVfGbdk8y5NWf25XFcv8pKU2H4x2MPfjQw+tRH9gWYaCPHX794yY8HTTP88AcBTjQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=F2SnKxo6sv4vSn1dXELKrcR20Glkqp4+7/ht9vZM4ow=; b=KG2T6QrBKr52w76udPJ1U8Do3tJdTJhOZ1iSwFJmRaqkd5kdqE0oapeBf3BXaBmtR6wBaJI1LZKto21uyp0U65e0hO1OzEQEorkXvM3WEWt4jX0CcG4YlRLKOvGEGVsLpHtl+OISmmazIgTYtZrnNXnug+p8/FQ1qlTXR+F+EQE= Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DS0PR12MB7771.namprd12.prod.outlook.com (2603:10b6:8:138::6) by SAEPR12MB231369.namprd12.prod.outlook.com (2603:10b6:802:204::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.592.8; Tue, 3 Nov 2026 11:31:28 +0000 Received: from DS0PR12MB7771.namprd12.prod.outlook.com ([fe80::9a3e:791f:33b6:3d8c]) by DS0PR12MB7771.namprd12.prod.outlook.com ([fe80::9a3e:791f:33b6:3d8c%4]) with mapi id 15.21.0569.010; Tue, 3 Nov 2026 11:31:27 +0000 Message-ID: <0d37c6e9-50df-45ea-9187-610b55c70c14@amd.com> Date: Tue, 3 Nov 2026 12:31:22 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/unaccepted_memory: Do not accept ranges that are no longer E820 RAM To: Ard Biesheuvel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "H . Peter Anvin" , Tom Lendacky , "Kiryl Shutsemau (Meta)" , linux-kernel@vger.kernel.org, Mike Rapoport , linux-mm@kvack.org References: <20261102113127.161823-1-pankaj.gupta@amd.com> Content-Language: en-US From: "Gupta, Pankaj" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: FR3P281CA0118.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:a3::13) To DS0PR12MB7771.namprd12.prod.outlook.com (2603:10b6:8:138::6) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR12MB7771:EE_|SAEPR12MB231369:EE_ X-MS-Office365-Filtering-Correlation-Id: 9994db77-0d60-44a6-5a4f-08df399dffdf X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|23010399003|7416014|366016|1800799024|4143699003|11063799006|56012099006|261009223027099003|261028144727099003|261022105027099003|261021121427099003|261102123227099003|261021135927099003|261026121527099003|261026140227099003|10067099003|18002099003|22082099003; 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:DS0PR12MB7771.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(23010399003)(7416014)(366016)(1800799024)(4143699003)(11063799006)(56012099006)(261009223027099003)(261028144727099003)(261022105027099003)(261021121427099003)(261102123227099003)(261021135927099003)(261026121527099003)(261026140227099003)(10067099003)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?bFgxR3BHZi9DbmlVc0x3QUo0R2J2WUY2em1OQ0hPQTVvVUs3TTFFK1UzTFRR?= =?utf-8?B?dXkrTytMMEduakpLSDRjdFAwR0pPc1lKbGJ4eXdVSFBxREhoMHJ2c3VTOXA0?= =?utf-8?B?bWV2TEl2MWFMMjFIZkE5UmZzUGJTcEVKSXJmMTVYdVZGMUcvOWd5a0J0Mkw0?= =?utf-8?B?K2JSQ0hrMHJQNGpsUmdJMU84M0NZNDR2MnBBTzVtM0R4QkNxaHBwN1E5b3R3?= =?utf-8?B?eWx3NVFlV1M4bWRCK2g0MXpyeDlnTmI1UFlLUWhWaVEzWnJoSUwyZlQ2N0VP?= =?utf-8?B?OWdiNVU0YUZtR1RYZHFaR1g1VkJ2VjRCOXpFTGhSTWptalcyZ0I2OHhxcHFY?= =?utf-8?B?cTh6Y2dSUHJmL2VINVhJd3p5STFGbXpPM0ZjRHZ0SmpBcG1LQnhScGxDQ285?= =?utf-8?B?OCtZK1pjdTRnSlJwRVFmNDMxSHhrYTgwNW5SN01VQUR2NjJQdzgybWVuVzhW?= =?utf-8?B?NDBwV0NtRTZ6U1VHR0lJK3VxbkRNR24zalA1NzU4REYxU09mUXRRcklUQklN?= =?utf-8?B?VnJZeStBZStnVUh1VlpUNGdJOUZOclcwaXMvWW9WeGJ3U05vZmUvVmZsaWZM?= =?utf-8?B?NTMwREQ5OGF0LzVxdm1JWDIvRC9qVDQ4SVFERk52TW1qNkU0S2J1dENSSVpS?= =?utf-8?B?U1J0S3dKSkJ3d1V4eng2N2grZjk1ZVVmNVdtRXRyUzBJTWRVc3NJR2lKbldr?= =?utf-8?B?dndJcnVNL3RTSm96QkRNenNlRmRkOWhsYnl1VTZZRS84MXg2ZlorQkpaZXdP?= =?utf-8?B?R3FCd1ZIekJoUk01K0F6MVRMazZvc1QrbkJaakZEbUZEMEtLWGFSN25jckhv?= =?utf-8?B?M0xFY0Z2ZUU4TFdUUUE5RjdMdTFHZUZxL0RWSW11cC9qbkhZNjFhaGZqM1d1?= =?utf-8?B?OVhLOStNZE9XQm1IYnFPVFhBN1FhYXBpZXFYUTlEVjExL1ZEbEtpZEFKaTNP?= =?utf-8?B?Vi9xT0dqU1orY3NLQ2dNRFZRTWdGL2hNWXlKQmM3cTJOL28yZmNWNFJVVis1?= =?utf-8?B?Yjl4RWFhd2JYdmlLRGJBMk51UkVIa0tKc3FHNytrV3kzVG1uOFRadVpNYlc4?= =?utf-8?B?eUx0RWhRN0E5UEN3aHdVUi9ZdytpMVY4YjJGTlM2QisvaU1Uelo4VVhVclFn?= =?utf-8?B?N3ZCZUh4a2NBVlBtSVlvV2gwTHhNbkhURHk3eXQxUDRNK2lGNmpSamZPVjRv?= =?utf-8?B?ZGx2RWx0Sm1PL3JFN1RoYmdsc2FrY09kWENZQUlheURTZGhlNW1SREt0N051?= =?utf-8?B?MVNhT1dmTHcwRGVRRUdHbTdBbHhudENQbWdXUm9GNEtzYThocnFJZFAxalZ6?= =?utf-8?B?T3ZGN0RIQ1pPVzJjMFRHZXpMOTRWd2Q5aERDWVZpYngyZFVKVlZRWmN3a29P?= =?utf-8?B?U1o1eVRPNVN4OHdYaGVQVEVaY2liS3JydXBJdCsvL0hhc1ZOYTIrYnNzbVpE?= =?utf-8?B?VVNoYXlUdWFnYU1BenNOTVgzSWQ4RWFIZXRGcGNlVENDWks1K29NSEZycXVP?= =?utf-8?B?ZmxHNmY2N2xIaER4MnRCZGNCUXpUM3JWdWk3MVVDdUdjSmljcTJLQWVqODR5?= =?utf-8?B?azZEQ2IyK0pzMXkrSU5GZzNVMkp1SUYxU2pWUUdRVy9kZUx3cmxSUm1KamZT?= =?utf-8?B?cktzRy9Ia0d0NkJ4ZEI2SFAxajk4TnlYZnhWbCtiRDdRMjRUNVljaTgxS2R2?= =?utf-8?B?TFZ0eW9TdUxVMHZsQ2t5cWdZU3ZFSC9ySkg2Q3RrMEJPVUxWcWpXeThXM3ZN?= =?utf-8?B?Z3ZsUnJFTGswTU9HZ1ZBaEd3cTBtMkMvRnd0SDd3K2NIdDYrYXMrOC9rb1Zp?= =?utf-8?B?cHBoaXpRSmR6cVJ5R2ozcDNrdHZrWFJPY2tROWo2blRuYkk1enhQZHpaK3Zl?= =?utf-8?B?WTFwM2FtUEMxUXpSWVdybVhQcmU0QmRjdkFyRkFNYzY5RHFsTFljNGpsYllE?= =?utf-8?B?M3hsRzV2ZFdLL2NoS1BrMk9xdFJFUytpbDFOQ2ZEMjIxdUs2SVZJaS80RHNh?= =?utf-8?B?SEpKdFcwMm1ZTjhQbTZmSUprU1lGZXBBaGZsc2NHRmVlNlZZT0NzemJoSEhv?= =?utf-8?B?YUFmdUY3MExRdVZBek94cHlmNFdydjRxNTdiTkM1cnd1ejdLVEV6QitNdGZy?= =?utf-8?B?dWMrS080SjVod3hKOGdDVlc0OGNhc1dyTTNhbjJNTWxsVXY0RGhLQWhENFVk?= =?utf-8?B?M21xcjBwY0dFdE5OS0xrSXlaZDlrMXJkR1ltNnhLY1dmY0c3VnB4Qjl2c0Mw?= =?utf-8?B?aEhxTGppcE0reWdyenlTQWlzVlZjVlNISmRucEFPL2RWNCtrTXRxVXpNZHp2?= =?utf-8?Q?3t6N76/sGdvE1vMdWx?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 9994db77-0d60-44a6-5a4f-08df399dffdf X-MS-Exchange-CrossTenant-AuthSource: DS0PR12MB7771.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Nov 2026 11:31:27.8163 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: PilKoSG5me1p/6KlkChbXWLYH07t/FyGJc3xQV/nM67XlOd1N+yahM8SeUBrIFRs6NBRzTo5aI5gkl4JlJD8xg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SAEPR12MB231369 >>>> Can we just disallow memmap= when running in a confidential VM? >>> My experiments showed: memmap itself don't have a problem but memap >>> with a hole is causing crash. >>> >>> There might be some usecases which are already using this, e.g: >>> >>> https://lore.kernel.org/all/20261029-cma-multi-v1-0-2cbced8b5cb7@kernel.org/ >>> >>> >> Its also good to have a general safeguard to not accept memory that is >> not marked as RAM in e820? >> > Personally, I think all these command line hacks should be avoided in > confidential VMs, on the basis that the firmware's view of memory should > be in sync with the OS. Fair enough. I can post a separate on top RFC patch to disable memmap= holes completely for confidential guests and see if anybody objects. That said, this patch fixes a real crash with memmap= holes functionality in confidential guests today, and should be backported to stable kernels as well. It also hardens the existing code to only accept the e820 RAM regions. Thanks for having a look! Pankaj