From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 418C019E968; Fri, 31 Oct 2025 19:04:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=198.175.65.16 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761937457; cv=fail; b=nglyhHv8Iz2OVH9mNOZXYvsThmT2N+uQLOsgwFtB5ZABLcNFix6R2oiEQtURIRBxbykhFi6vr0BSt88l0gSmtdqC7yagHcedUUSIq9tBef6TiYE3++6xWTPyoitU0NpIpCQwCUts6tSEdSXejK6UNe4VbtBdf2Uu4UUxz/t+/Og= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761937457; c=relaxed/simple; bh=Om4Vx2xrhM/wPr/m+jkIeD9TNDnovJ9rpBN+mqK/Cu8=; h=Message-ID:Date:Subject:To:CC:References:From:In-Reply-To: Content-Type:MIME-Version; b=gEMMzdl9BbISQahCujAca5RSH9hzi/8uzqSVlbCXwOwJjMvPA6TBPHIWcW/9cP1uKaEQo5ldSI349kLo0YoPG+lQGGHLTmSfgDkBXolbKLaNC9uo5OGMTWK9AVMSc/8yPZ0al0jhjoUPWLxcau1+D+0hiQb+5pl8DFkD4UVjQUI= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=eFYBrfqg; arc=fail smtp.client-ip=198.175.65.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="eFYBrfqg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1761937456; x=1793473456; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=Om4Vx2xrhM/wPr/m+jkIeD9TNDnovJ9rpBN+mqK/Cu8=; b=eFYBrfqgRpzbJGPz/PqhRpcKwcSJlkhM68XLIrLNIL4EoFji2lRdCmkH VDRHFkypchP4ad70G3sDCFFUkvSALnpvOR86GPj7dUiwC4gAyZ6e2z1QR MoqHjpehaibjRiu3ip+zWdM2RX7KJmaz1e2euyG4F9hk7YMydddRCpwO2 sFkxK+1IHj/+puqxcuZSNkLvqIroZzGvvMFSew1mjA/nj+AtDBT67nJ7E kcqB1ZuXuFWbhkS8EORMUm5vtnR2srbASn+tMmsPRVABGnBcgXNsKL6F7 XQ0WV0+24JFnKxnJqQpvnyX1yVjgypTECJaq9IwEGfMOWaIkCWirdCUA8 A==; X-CSE-ConnectionGUID: MgZnkHTRTou44ip8HW79jA== X-CSE-MsgGUID: yU50FRBNTF+Ad5QY6FvEDQ== X-IronPort-AV: E=McAfee;i="6800,10657,11599"; a="64256145" X-IronPort-AV: E=Sophos;i="6.19,270,1754982000"; d="scan'208";a="64256145" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Oct 2025 12:04:16 -0700 X-CSE-ConnectionGUID: rJ1Ok5OZSMmx5XAqcAso7w== X-CSE-MsgGUID: CVfgrta5StGX9PaSbVvl+Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,270,1754982000"; d="scan'208";a="185526273" Received: from fmsmsx901.amr.corp.intel.com ([10.18.126.90]) by orviesa006.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Oct 2025 12:04:15 -0700 Received: from FMSMSX903.amr.corp.intel.com (10.18.126.92) by fmsmsx901.amr.corp.intel.com (10.18.126.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27; Fri, 31 Oct 2025 12:04:15 -0700 Received: from fmsedg903.ED.cps.intel.com (10.1.192.145) by FMSMSX903.amr.corp.intel.com (10.18.126.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27 via Frontend Transport; Fri, 31 Oct 2025 12:04:14 -0700 Received: from DM1PR04CU001.outbound.protection.outlook.com (52.101.61.41) by edgegateway.intel.com (192.55.55.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27; Fri, 31 Oct 2025 12:04:14 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=c0qiqE3xbATAB1DtuUDEjF2vswoBtoTc9nj0FhtcHlvgkt8f+fSSwW8p/iAXlkB75FWsfC68FD7olEJxSL2GjDlgeFMq6i9FUEz12ikXhCtfhGv/BrD3wuzbHQixSFyfR5O3sp/C3NWf9fyT+3XekUnYMDQzkx2i/3rR8Dq4TG9KqAGEHjiuWWy7Fdud0mFi7Us2v33rhHPOx0XxDgHHpJg5CGyBzjvJdwrqvRhvgnBcLaYynLOjEdA44GLqRwExNmoX2zRd+LWe/fqzPCjGHT00kZ/l44rB0uhB37Ys5ADgaKKxlkyWE3AzsbvZmY6VbtX4vGRYI2ZPLNbNS19LgQ== 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=Or1HsdEIk1iqV0gLqSYW8yTlz6wKtr52yzymecRrPpQ=; b=d76BO87hjfptgvnCQ2EhaAm+/ekocCAyZu+cXMM1Pf5PKsCH3LjQG3cW+toQMrkm1mhjKLdqVAbMN9NaI1c+kKBMTQH8FgsCsGoeuzLbeVxR2mG13cHOZVDbaBovStgaizJ/W6A7HSrVTFEs1IoNVQMA1zV4B4EeppBxNZnwuxf+ikvGD30w6P/1na4uTy0XYUgs0AoMg02MxcJasYcwHdMlIfFVwUV6+hMHQhk9fQ6JTJie1yC9svrUALi6vBv/Z+jkoeza8VloqPCGvHDVf0TwJjfEqwWp5448f6ldCgFGavMPDmOq29UDRnKNAdzTTdLwELirFManM/hghQh6vw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from PH8PR11MB7989.namprd11.prod.outlook.com (2603:10b6:510:258::13) by MW3PR11MB4697.namprd11.prod.outlook.com (2603:10b6:303:2c::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9275.15; Fri, 31 Oct 2025 19:04:07 +0000 Received: from PH8PR11MB7989.namprd11.prod.outlook.com ([fe80::752b:acc8:a52:38ba]) by PH8PR11MB7989.namprd11.prod.outlook.com ([fe80::752b:acc8:a52:38ba%7]) with mapi id 15.20.9275.013; Fri, 31 Oct 2025 19:04:07 +0000 Message-ID: <27b6cafe-8cc9-4a01-af2b-3e847ff9aaa9@intel.com> Date: Fri, 31 Oct 2025 12:04:03 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 5/9] x86/efi: Disable LASS while mapping the EFI runtime services Content-Language: en-US To: Andy Lutomirski , Dave Hansen , the arch/x86 maintainers , Dave Hansen , Thomas Gleixner , "Ingo Molnar" , Borislav Petkov CC: Jonathan Corbet , "H. Peter Anvin" , "Josh Poimboeuf" , "Peter Zijlstra (Intel)" , Ard Biesheuvel , "Kirill A . Shutemov" , Xin Li , David Woodhouse , Sean Christopherson , "Rick P Edgecombe" , Vegard Nossum , Andrew Cooper , "Randy Dunlap" , Geert Uytterhoeven , Kees Cook , Tony Luck , "Alexander Shishkin" , , Linux Kernel Mailing List , References: <20251029210310.1155449-1-sohil.mehta@intel.com> <20251029210310.1155449-6-sohil.mehta@intel.com> <3e9c4fdd-88a8-4597-9405-d865fb837d95@intel.com> From: Sohil Mehta In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: BY3PR03CA0029.namprd03.prod.outlook.com (2603:10b6:a03:39a::34) To PH8PR11MB7989.namprd11.prod.outlook.com (2603:10b6:510:258::13) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH8PR11MB7989:EE_|MW3PR11MB4697:EE_ X-MS-Office365-Filtering-Correlation-Id: 16f1a490-0ebc-4688-392f-08de18b043ed X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?MDlDRXlidGltZkQrcGhLeXZJSDFkYmNkL1k4UmFXZVA3WDhFcnE1Y3kyMGtH?= =?utf-8?B?UVZhOGVMbm9pQllpTFRjYStsS2lQYXIzQUNtMGY4SVJFZE5DdTdTelFhcU1P?= =?utf-8?B?c2tuRXNIV2lGd29SalU3R3hOdUt4SzB6Q3RxbUt6ZkRLVDIzTWZQVVpLZ1dB?= =?utf-8?B?eXdmdDRCSkRQbEQwbzZkSThmL05uSkxjcEtHT05EUENNODcwb0MzTWN5S2ph?= =?utf-8?B?MTRtbXJoVXU5eUtRcU9JWnlmTWJZSVJSYlBFOS9qUXFRM2dNUFhsYnNwMFBS?= =?utf-8?B?bTVXVW9RVUZQcndGcE5TTG1oRWI1Q056NHNGMmhpQlhiRGJxSFpGQzJMckJR?= =?utf-8?B?cGR0TEEvS0JwMER1SlZNeFpnOGgwQ2xKSWlNV3NBZE9QMkF6VURiQjhuRmxl?= =?utf-8?B?aXRIclRZRGoxcXJOQTBPeStYd3A0T1lWbXBtbUdYd0RVaDBLUUdUR1gzUThI?= =?utf-8?B?NUpYK3F1bXQrR0pXdU1iQkszOUhOejFMTm9tRk9zUUMxVzl3cExLd3Y2cnh4?= =?utf-8?B?ODAvbGRYR1VZa0NQdG5DcUlrUFliTEdwb1hZNitIa3FEdVc2cTNveWhOOVZa?= =?utf-8?B?Mld0OUMyK0hnSy81R0RvbXBOYTRDOVF2YXdoaDdFT3oyL1E4cGg2Z3pocVk3?= =?utf-8?B?SzNLYlBKMXdLR2xVMGY4TTVoRzltV1BWQitlTnVnOWUrKzBTb3J3RklaMElz?= =?utf-8?B?QUY2blIvaFkvVW1RMW1VSWxWYTdLZkQyQkVLOHBuendqMXJIQm5TT2d2c2Zv?= =?utf-8?B?cWFjSU11TlNGMGI3UmowOFdWZ1B3RXlCUXZvU2J1OWxIUXNzc3g2ZUFyUE5D?= =?utf-8?B?VzQzUXFWNGwydG9NcFpOeUlOTkx3MmsvcGUxWG5PQ2R1ZjRKSENHZ0VVdVQ2?= =?utf-8?B?WjVYUml1cmdkSDlRZTBoVnNYVjhEVXRtTll4ZlRlWlNpdmZGS09RdnB1cDFp?= =?utf-8?B?SkhwaFBJbWRBWG4xU1pBbnVEQzdRNXQ5c0U2bkg5NlhzcXI0RUwyS3g4Wjgr?= =?utf-8?B?SVM2VGFMdERBRE44U3NNYS9YSHZTQzQyTGducTR3Z3Z0RXUrOGdwTGtJcm5l?= =?utf-8?B?TE85RWlYaXM2NEg0Zk9yZ1k3Z0JnU2YvQXlJOGxUbml3NEtocG1LZ1R4TDNV?= =?utf-8?B?NHRvMUZXbVYxb2dvL202YzY4a052RXZucVROU05iZ1FpU3hORFBEZ3J3cWFO?= =?utf-8?B?QTJjak13Nyt5Sk53a2lXVmhMcmtwWS82RTJRSE5MQXlocTM1akVSeGxtQlBx?= =?utf-8?B?d2JwcVNQRFUzYnJZa2FEUjRSeVdtTzQwa2w2SEpLQzJmR21MU3lpWlFrNW1M?= =?utf-8?B?VmRoVUEybStYRklTVzBsT00ySFlxc2d1MUZBeHZ5MllkSzdUc3JucTZzN21K?= =?utf-8?B?dWxhb21aVDhtcnFPOWwrdzdIL1E0blZKUzN2RVRQSjhkS2t0SG5IVHRqZmVt?= =?utf-8?B?czBhdGZLbGVnOVAwYytLT1VhV0tlbHdFTXdFNU1XMmc4UERIR2hwczVST3ow?= =?utf-8?B?YkJQb0dPaVpJejEyTHYrVzA3OGNmNUVYbVI3M2FVU083MWJSMFE0VFlpSWdz?= =?utf-8?B?dnVUaHlVTk41QTN1aFlRL0JvU08vN2o5YmpwU09VanBMVkFRQ3NualBIQkZG?= =?utf-8?B?SmZQK1pyRXNzUU04dFdyRXdoOUxHQlhEdDJPc1VaSzBIU1QxV0s5dDQvVkNn?= =?utf-8?B?QnpOWlF5RngvYlBxbXVEME9DbENHSjBwWG1pcWRuZ04zaXBidW9ERjZGVEdm?= =?utf-8?B?enl0U3lFOHgzbFF6cmZ4WnRCLzhBOVU4T3QvanpZaU9odUZNc1JONlBCQVdh?= =?utf-8?B?ZEVLL040SGd2ODA0L3kwRGtVWCtpV1pUUDlFRmlYeFRFZVhlUjRMQUxMb1cx?= =?utf-8?B?bWZDWEtBTjltNnlxbU5GZGI4Lzg0VCt4Tmk3bGJyVndqMUh0L3hwUzE0UmdE?= =?utf-8?Q?h8S+M+k/cp8BU3BlFAJzmTVkc0o6WM5J?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH8PR11MB7989.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Q2UxbDZ1eGZya1NHSEVHVWNBd2hNM3pjOG5Nb1QzK253bHcraklQT05qTDZF?= =?utf-8?B?TEVsOW11dTVtOHQvNE53c3FacURTQlowK3pLUlg4dFBhUkNlNDdjNnlqVEJH?= =?utf-8?B?SWkweCtkeDl4dm5wQ0lMcXVKdFVuWDdMTU5JOEhtSVNWa0NwQnd4TDJDSjNJ?= =?utf-8?B?Mm5pK0RuRlFMd1lCZFYyamdZYmRVNzNEM3dlOGlSanpmRTZ3blJ6aFNwNVJx?= =?utf-8?B?YlNGQUMyWFg0YjRQMTRhaHBud0tqREhxVkZwaGN5Mm5mREM0c0QrRXBBekor?= =?utf-8?B?TFpLSURoRmljcE96c3ZoZ3FFbkR0czZ3WHJGYVhlcXRoR05HYlZTU2ZBZVpE?= =?utf-8?B?cG5FenJEemdweWlJa2Z3K0N6VGVCQ3RyR2k1T294UmNxK2JZV1FLSTAvU2JD?= =?utf-8?B?TTJmLzZlQmYzSkNTOHhvOXhZdmQvRWpxaVlkQ0RDTDU0czJLdCs4RThFUTBQ?= =?utf-8?B?SS9ybnUvNy90TEM4ZEErL2g5VzhkbEYrVm5jZlBZV01WeDJhT3BFb3JPQkRw?= =?utf-8?B?QVFYZnNXbHRWTjhtZ1QyM04wWDR5QTRJRzh6WUE1U0loVWN5UnJicHh3aW0y?= =?utf-8?B?RnVzWk91NVZMaER4V3o3OTZ5NjAvNW9MRUFCYkdsSzJ6WjN6UkUrYmEvd0lY?= =?utf-8?B?bUFmbXV2bGNvZmo0dlh2YUViRE84QUpkUFhpSmhPaW5ka2daR295bW1SRXZK?= =?utf-8?B?L3pYSHUxUXFBVElNMEEwaFp1Y29HSWVVazI2MnNCaUlCWFphK2dGamFtbUNz?= =?utf-8?B?ZVp4T0gzV0hseXBlczVjdmZFbHMrVUdUNENaMWlJcmlvUlVlTS9lS2NrTWVp?= =?utf-8?B?UFpNSDZMMXF2V2VDanNoOTIzY1BDZU5wUWZtNmJsNHgydEpVTVlPdUpWWWRJ?= =?utf-8?B?RklpUCtSd3FMYWFsQngrWVpGblJlRHQ0cnE1Vk0yblh3UUpEZjN4Vldwb0Nr?= =?utf-8?B?ckRtUFVNYUloTTVTcUpic0xlbDlaWnZaNnhsYlI0QjJFc1RaYjZhdmNlNmU0?= =?utf-8?B?NVprdFdaZTA2eGhPM20rK3ZCY1QvMExhTm90dStVc2hFNUM2QklvS1dPcjZ5?= =?utf-8?B?VGNVTXA1WllSNmszYVRHa0txdXMwME5yUTNzNGtBOXdMTTJGTTEzTmlEb3NG?= =?utf-8?B?ZXhFb1MyQkdqQUptL0hhazVQVy9Rb1NndnpiSUQzdS8wUldQMlU1ZEE5M0Mw?= =?utf-8?B?Z1c1c2xiTjJUMmo5cno2N0oyT3Vya2VSMFphRkZMNU5OWnFUenpZQ3VhL2t3?= =?utf-8?B?d2lmT2lBMFdMZFJVbmlHWk84NUFqbHQwckV0cmcwU1Q3b2wrNE45U0Nsdy9P?= =?utf-8?B?VHd3eW9IZjRMeTVOS2QvL2Rxb2FSUUNFZnpwaGVjSGRBQnFhTEpPaDAzQnp3?= =?utf-8?B?TXIyazVhc05BbU9jVW84VDhKYVF5UkxnSDdVTVZjdVJmTURiVmFzeHBhZzYw?= =?utf-8?B?NGcvQ1NlS2xpUDJhQkk0OU1xRm43OFc1c0o5TytQYmxrc3ZmdlVmUnRubWds?= =?utf-8?B?NWxITy9JZTFnVDRuTjhFTld2a0lsbWdMMUx0SmlQdGxPWmZLc2dyRTVnanpN?= =?utf-8?B?VEVLR0tYTVRDcWFEMFhpNkxCUXFtV1lTa2Y5eUg1NkREaUwxQWJrVzYwR0FQ?= =?utf-8?B?WUVzWVpwMzcyVFk2YmJvcnpnUTM0blJpL1BHbk1yaHZNdUtkZDdDUWlqaVpR?= =?utf-8?B?SUMzNWR2Zm1zamVPbWtyYlRXN1l0TFgwZDluT3BwQ2gwSGRXWUJ2V2d5REtm?= =?utf-8?B?RDRyaVNnNE5xdVcwQm8vMXAyTWNLZlBNUG1oVXpjNVI0eXZ6eVVZbk14ekU5?= =?utf-8?B?YVY0SmdYZktxNmVIYXdaU20rZEs1S0dZeDR5ZkJMbTNCRVlkMmVWOWVOc1Nj?= =?utf-8?B?NTkrbHZ3eDVIQ2kyeTVNSDAxejZWN0FVQkl2NVJ3WU5oeGh6NHJxNFc1Q3Fn?= =?utf-8?B?VzZmNE02Z3RjQWQweE51UUlWZEdPS0RqTTRNbG1ZMTBjQ2c5ODF3NWRhUWNa?= =?utf-8?B?eHBad0dIV2Y2bm5RNW5VRHRrWXNjNXhNMHVMYmlaeVNkRndWNTlGMGowQ3FY?= =?utf-8?B?Ly9ZLzd2S09mSDBnbU01NjBIRTF1ZE5BR3g5MElhQjN3Um44LzdsUFVZay9X?= =?utf-8?Q?4XSPQ6ivJx5u2mNW+F8tNvRYK?= X-MS-Exchange-CrossTenant-Network-Message-Id: 16f1a490-0ebc-4688-392f-08de18b043ed X-MS-Exchange-CrossTenant-AuthSource: PH8PR11MB7989.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Oct 2025 19:04:06.7714 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: m+GAsBKZF1vekNrT6u3dJF66KoLddvzoENCFWwW5nXfLnCiG7dCV9ZdltpxjVZ4gbALBNeu0IYWGh2eA5Sfo7w== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR11MB4697 X-OriginatorOrg: intel.com On 10/31/2025 10:38 AM, Andy Lutomirski wrote: > I have another question: why is this one specific call a problem as opposed to something more general? Wouldn’t any EFI call that touches the low EFI mapping be a problem? Are there any odd code paths that touch low mapped EFI *data* that would fault? > I assumed EFI is running in physical mode before this. efi_sync_low_kernel_mappings() is called right before calling set_virtual_address_map(). So, this is the only call that happens at the low mapping while switching to virtual mode. But, my EFI knowledge is fairly limited. I am realizing that there are some assumptions built into this patch that I may not be aware of. > Is there some way to be reasonably convinced that you haven’t missed another EFI code path? We have been running the patches on internal test platforms for a couple of years. But, that would only cover the common paths. I'll dig deeper to get you a convincing answer.