From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BL0PR03CU003.outbound.protection.outlook.com (mail-eastusazon11012026.outbound.protection.outlook.com [52.101.53.26]) (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 332504483A2 for ; Fri, 24 Jul 2026 19:57:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.53.26 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784923023; cv=fail; b=SYCDBT4+QJ0tHfPS39/1zqBIU1qCnNJ2UeVYiNj6wu5CZKxdu7W377oOrmOfDIu8xhOBdN1Ozxb4X394fgWmbQW3Bu12LmkXEX0o2HMOrgoj7FUhNLJI5NZ6uCqTAADzpnOIy/OVI4dpscQUqbzRK+bADLQUqMHxYwEWswuKE84= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784923023; c=relaxed/simple; bh=xYC0hbMgYeMmzqbao33ggnO8Mly6CoTyuvMKWsvgUT8=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=gkfpY8HRN2QSf/4zP+wmU/Bf8I+JiR56YBrbPvkJd897v0svuaA3pA1w8ZnKH+3sOFwXNzLyiTpoUaScXDxxZzvy72/FCDG2wgdYIVGgP/B5Ne2YPzYYAP5n+V6IFv+02aHPHLPuNpTcpgHMR5yFSz9iozGfgjwfzID4iuNSPmI= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=y86Gz9oI; arc=fail smtp.client-ip=52.101.53.26 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) header.d=amd.com header.i=@amd.com header.b="y86Gz9oI" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=KfCwsLwl9+mkMQqauYj89lvG5exOv0FJ9O3Td+s84ulWKYMEi1UVOqIzShbucq9fnLAsKaq5/kbTT/sJ4AVyFn+nb5ETvxAQenNXVrFQH93hxyDG1bTZMEvnpLsbrm6VFas2xkEEdADsdf5hubnJO65unXUjMpq+62R3Qwr8ISQIGxmg4cTveytODGncTDFrUdzupO5wRJ5TQvjuYOIr+HSanXbLtdEcSPwTZ0GIXe2s+R2QFYcRKKV76CB5kU+VKFIqlVNKC8tc/Jk2nEspT05zK9Pj+x2UBEM2VMARR55cgeXTEH7eJzTrjUUAvk1IGZI5aNDu4A8QYyI+FGO5OQ== 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=Y51+Xn6JuTLN55qVgB7DLouJjmXx2f9Ddy0nxNLgXrI=; b=Psh5NH16ep9gXgLmlsxNhndqKCCVjKXLggOK6HI7Aqp5bp4XERSG3QkKBwKx1O9CeQib46fZzzmKg0cJWCNqtx4FjU11vr0wccmT8KNQkOHLqa3YgC1u6J+1genkDUxNZvOE6OPHdiCIHnBxWRX3SSTJsYNlEvkDGr4sV2F1UFV6trTeUJVrR1AideKkDhl7rJcvgcbfTH30Hfh87hmHnhlswp3Y5HLqZy5tQjTs094njk8JW6jNqofwACrqadI4VFyHio6ghW47DyT+9p4KKn0NeiU2XJ834dx58qcNwi9oKrmqgYRNHkEZPB4sT7lxb6wAHyzGmyaoTfNZfi86qg== 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=Y51+Xn6JuTLN55qVgB7DLouJjmXx2f9Ddy0nxNLgXrI=; b=y86Gz9oIqSvU0JIQwfraEd2QW1Uo6u+TnZWVHer3jseXDqrvTLJPGyj6vAC34vjO9O6Oa7B0M4GpN4jIAtSBM8igL7JMiodZcLxIL+6/8VDN+izpFl8T1TxxXq4sVHqtobmPEAF0mY8oSoK+yU1UYSiSa+eqrh6E48NUfc0aUMM= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from SN7PR12MB8131.namprd12.prod.outlook.com (2603:10b6:806:32d::12) by CY8PR12MB7146.namprd12.prod.outlook.com (2603:10b6:930:5e::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.245.10; Fri, 24 Jul 2026 19:56:57 +0000 Received: from SN7PR12MB8131.namprd12.prod.outlook.com ([fe80::c2dd:62c5:67fe:aa46]) by SN7PR12MB8131.namprd12.prod.outlook.com ([fe80::c2dd:62c5:67fe:aa46%4]) with mapi id 15.21.0245.010; Fri, 24 Jul 2026 19:56:57 +0000 Message-ID: Date: Fri, 24 Jul 2026 14:56:54 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/5] x86/sme: Clear decrypted BSS separately To: Brian Gerst Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Borislav Petkov , Ard Biesheuvel , Juergen Gross References: <20260724030256.232690-1-brgerst@gmail.com> <20260724030256.232690-2-brgerst@gmail.com> <227a7dd7-445c-4b87-b0fb-cb53b2e387eb@amd.com> Content-Language: en-US From: Tom Lendacky Autocrypt: addr=thomas.lendacky@amd.com; keydata= xsFNBFaNZYkBEADxg5OW/ajpUG7zgnUQPsMqWPjeAxtu4YH3lCUjWWcbUgc2qDGAijsLTFv1 kEbaJdblwYs28z3chM7QkfCGMSM29JWR1fSwPH18WyAA84YtxfPD8bfb1Exwo0CRw1RLRScn 6aJhsZJFLKyVeaPO1eequEsFQurRhLyAfgaH9iazmOVZZmxsGiNRJkQv4YnM2rZYi+4vWnxN 1ebHf4S1puN0xzQsULhG3rUyV2uIsqBFtlxZ8/r9MwOJ2mvyTXHzHdJBViOalZAUo7VFt3Fb aNkR5OR65eTL0ViQiRgFfPDBgkFCSlaxZvc7qSOcrhol160bK87qn0SbYLfplwiXZY/b/+ez 0zBtIt+uhZJ38HnOLWdda/8kuLX3qhGL5aNz1AeqcE5TW4D8v9ndYeAXFhQI7kbOhr0ruUpA udREH98EmVJsADuq0RBcIEkojnme4wVDoFt1EG93YOnqMuif76YGEl3iv9tYcESEeLNruDN6 LDbE8blkR3151tdg8IkgREJ+dK+q0p9UsGfdd+H7pni6Jjcxz8mjKCx6wAuzvArA0Ciq+Scg hfIgoiYQegZjh2vF2lCUzWWatXJoy7IzeAB5LDl/E9vz72cVD8CwQZoEx4PCsHslVpW6A/6U NRAz6ShU77jkoYoI4hoGC7qZcwy84mmJqRygFnb8dOjHI1KxqQARAQABzSZUb20gTGVuZGFj a3kgPHRob21hcy5sZW5kYWNreUBhbWQuY29tPsLBmQQTAQoAQwIbIwcLCQgHAwIBBhUIAgkK CwQWAgMBAh4BAheAAhkBFiEE3Vil58OMFCw3iBv13v+a5E8wTVMFAmkbaKgFCRZQah8ACgkQ 3v+a5E8wTVPFyg//UYANiuHfxxJET8D6p/vIV0xYcf1SXCG78M+5amqcE/4cCIJWyAT3A1nP zwyQIaIjUlGsXQtNgC1uVteCnMNJCjVQm0nLlJ9IVtXxzRg0QKjuSdZxuL5jrIon4xW9hTJR 94i2v3Fx5UWyP2TB6qZOcB0jgh0l01GHF9/DVJbmQlpvQB4Z1uNv09Q7En6EXi28TSv0Ffd1 p8vKqxwz7CMeAeZpn5i7s1QE/mQtdkyAmhuGD12tNbWzFamrDD1Kq3Em4TIFko0+k5+oQAAf JFaZc1c0D4GtXwvv4y+ssI0eZuOBXapUHeNNVf3JGuF6ZPLNPAe5gMQrmsJinEArVYRQCuDA BZakbKw9YJpGhnSVeCl2zSHcVgXuDs4J2ONxdsGynYv5cjPb4XTYPaE1CZH7Vy1tqma8eErG rcCyP1seloaC1UQcp8UDAyEaBjh3EqvTvgl+SppHz3im0gPJgR9km95BA8iGx9zqDuceATBc +A007+XxdFIsifMGlus0DKPmNAJaLkEEUMedBBxH3bwQ+z8tmWHisCZQJpUeGkwttD1LK/xn KRnu8AQpSJBB2oKAX1VtLRn8zLQdGmshxvsLUkKdrNE6NddhhfULqufNBqul0rrHGDdKdTLr cK5o2dsf9WlC4dHU2PiXP7RCjs1E5Ke0ycShDbDY5Zeep/yhNWLOwU0EVo1liQEQAL7ybY01 hvEg6pOh2G1Q+/ZWmyii8xhQ0sPjvEXWb5MWvIh7RxD9V5Zv144EtbIABtR0Tws7xDObe7bb r9nlSxZPur+JDsFmtywgkd778G0nDt3i7szqzcQPOcR03U7XPDTBJXDpNwVV+L8xvx5gsr2I bhiBQd9iX8kap5k3I6wfBSZm1ZgWGQb2mbiuqODPzfzNdKr/MCtxWEsWOAf/ClFcyr+c/Eh2 +gXgC5Keh2ZIb/xO+1CrTC3Sg9l9Hs5DG3CplCbVKWmaL1y7mdCiSt2b/dXE0K1nJR9ZyRGO lfwZw1aFPHT+Ay5p6rZGzadvu7ypBoTwp62R1o456js7CyIg81O61ojiDXLUGxZN/BEYNDC9 n9q1PyfMrD42LtvOP6ZRtBeSPEH5G/5pIt4FVit0Y4wTrpG7mjBM06kHd6V+pflB8GRxTq5M 7mzLFjILUl9/BJjzYBzesspbeoT/G7e5JqbiLWXFYOeg6XJ/iOCMLdd9RL46JXYJsBZnjZD8 Rn6KVO7pqs5J9K/nJDVyCdf8JnYD5Rq6OOmgP/zDnbSUSOZWrHQWQ8v3Ef665jpoXNq+Zyob pfbeihuWfBhprWUk0P/m+cnR2qeE4yXYl4qCcWAkRyGRu2zgIwXAOXCHTqy9TW10LGq1+04+ LmJHwpAABSLtr7Jgh4erWXi9mFoRABEBAAHCwXwEGAEKACYCGwwWIQTdWKXnw4wULDeIG/Xe /5rkTzBNUwUCaRto5wUJFlBqXgAKCRDe/5rkTzBNUw4/EAClG106SeHXiJ+ka6aeHysDNVgZ 8pUbB2f8dWI7kzD5AZ5kLENnsi1MzJRYBwtg/vVVorZh6tavUwcIvsao+TnV57gXAWr6sKIc xyipxRVEXmHts22I6vL1DirLAoOLAwWilkM+JzbVE3MMvC+cCVnMzzchrMYDTqn1mjCCwiIe u5oop+K/RgeHYPsraumyA9/kj8iazrLM+lORukCNM7+wlRClcY8TGX+VllANym9B6FMxsJ5z Q7JeeXIgyGlcBRME+m3g40HfIl+zM674gjv2Lk+KjS759KlX27mQfgnAPX4tnjLcmpSQJ77I Qg+Azi/Qloiw7L/WsmxEO5ureFgGIYDQQUeM1Qnk76K5Z3Nm8MLHtjw3Q7kXHrbYn7tfWh4B 7w5Lwh6NoF88AGpUrosARVvIAd93oo0B9p40Or4c5Jao1qqsmmCCD0dl7WTJCboYTa2OWd99 oxS7ujw2t1WMPD0cmriyeaFZnT5cjGbhkA+uQGuT0dMQJdLqW3HRwWxyiGU/jZUFjHGFmUrj qFAgP+x+ODm6/SYn0LE0VLbYuEGfyx5XcdNnSvww1NLUxSvuShcJMII0bSgP3+KJtFqrUx9z l+/NCGvn/wMy6NpYUpRSOmsqVv0N71LbtXnHRrJ42LzWiRW2I5IWsb1TfdMAyVToHPNaEb0i WiyqywZI5g== In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-ClientProxiedBy: CH5PR04CA0022.namprd04.prod.outlook.com (2603:10b6:610:1f4::19) To SN7PR12MB8131.namprd12.prod.outlook.com (2603:10b6:806:32d::12) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SN7PR12MB8131:EE_|CY8PR12MB7146:EE_ X-MS-Office365-Filtering-Correlation-Id: e8407d75-b5d0-4edb-7618-08dee9bdb76e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|366016|1800799024|376014|11063799006|4143699003|10067099003|56012099006|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:SN7PR12MB8131.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(23010399003)(366016)(1800799024)(376014)(11063799006)(4143699003)(10067099003)(56012099006)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?K1RZQmpuSmsxbEV4dUEwTnpZUUg3WDZ0b3VpVVBiYkFCSDRScVl3ZC9MUDlF?= =?utf-8?B?cDl5K2xjbTZTVGVXcEZoYzhheFFJbDU0KzRCenoxNnR4TnlzN1owM2UwTm9D?= =?utf-8?B?U3FidVZySCtBamFnazlXUkk5TUdOd0RNRmc2Snlram5nN0hjZ0RUSEtKMXhp?= =?utf-8?B?aUc5dXE0eWp4L2wwTVp6TWYvNTh0M2NTaWRNT01lbGZtUnlkS2c4UVVSQ3Ez?= =?utf-8?B?UG9lTHJRTC9LZEVZVDk5WUpRSmpxbjFnYXB6TENkYmJvWVB2V1MrL1JBeUdT?= =?utf-8?B?a05EK1hqT1VCVW1qclMvSHgwcXhsc1NveHNwQzFscHh1UWpaYlNGUzBuWHBE?= =?utf-8?B?cTJBN0pYaWlXTit0Q3laeTkxMHNtNFQ1cGEvQlEwa3FuM2FmdjlFSG83SmNX?= =?utf-8?B?c0Jhem5TcFIvWnJLMjFRaFFReC9GYms2VU41M3FGK2IzTitjV0hOVVdaa04z?= =?utf-8?B?RC9heUtVVkFZQVlSOEwrcTU0Tk83T2NodTd2YW1FK0c3L1Z2RWdaaFNQL1NB?= =?utf-8?B?dlAyWjZRWFBEdjBHUGM4SEtMWEQ1OUwzeWI4WnRNcitBNTMvR3E5QWNhSGxj?= =?utf-8?B?bVZScThhTnhEQ0dCRjlxcVRHTWsrTXpMYUtRcjRLdHJ3U3FjdWl6RjBseEMx?= =?utf-8?B?WEdTck4vdStMOG95bWRHNXowMzZQWjZ1ampCeHZlaHVlekRLbE5YbTlpYTJn?= =?utf-8?B?MGxaTjlmWDBMemlHcFkwNGtBek5PYmVheVNnaG8vaVdCSXJVWkdlL0tpR3JT?= =?utf-8?B?VkNBdFNlTEJwQ2h1bGRZelFJNGJlQ1k0V3RNSi96TnAvM1NkdERZSXB2SGpH?= =?utf-8?B?anhoUE9QRW95NXNOejFPSTM4bkg5Zkh0dEFBbzIrMlI2RHVDamJMazkyRnRp?= =?utf-8?B?My9uNXhmelpDbTc1TUphVlFHWUpwaThvcm42TkxFSzQ1TTh4S3hhVUhLMmYv?= =?utf-8?B?ejltSmJyYklReE5oWTV4bXEwcGZyd1BkRkhCRWQ2OTVvYUN5VDlYTy9hNlEr?= =?utf-8?B?NnFDdE53N1ZPbU5jOXlLSjNJcXZuek1Wbk4xMDV2REI0Ukszem5BMGs3OS9q?= =?utf-8?B?T25BaU03NFcwZUxUazlXLzJuam1ZUXF3MDRsV1RVczBpQU13Ui9kaGVMRGRu?= =?utf-8?B?V01HSzBjRmFKQWg4aGFhTmlJQ2hUemNMaFFqaFhTTCtwaXc1SVFJUVVkVEVV?= =?utf-8?B?U2NHcVA2bmh0OUlCYW0yNjhFNU5mc3VGMmJrQ2lvUjJOV2tKU2Qvd1BoZHIx?= =?utf-8?B?VjdNRm51RVRZSEIzTktybkRyTi8zeDROWTZaQVRGdUQ5UFQzNk8zWDFiOTNh?= =?utf-8?B?c2lQNDlNUFE2dytWbXhVMlgzRnBocTEwVVBGQU5JOC9HZWMxR3p5K3RTbjY0?= =?utf-8?B?SG0vdG8ydi9SR0lrZE5rdk1sbFpEdG1LbnZSbWRoL0JIUTR5aWhiai9wUW0z?= =?utf-8?B?Rno4V3NyMUpBbGF6Q3RTcW93bnk5WjZtakRrbXEySnJKTHQ3S0NhOFR1QnJW?= =?utf-8?B?QzFoaTFabGFJVTVyWGRqbHRKb0NTTElZcGZJa0U3R2htZW5hNTUrNWNwVkR1?= =?utf-8?B?VVc1QmcvOHlmTXN1UFBFUkU1cjFreGdjbVhsSWhFMG9WOXFjL2pmVkZxenB1?= =?utf-8?B?WWtFdCtwdDhJemRwR2p1VmFsUHFleWgvN1lqQUlOZkRNVTc4V25pK3BTbGU1?= =?utf-8?B?dmwxUFBmVnlRRTVyT1N3WUlHSkgyVGVjMVE4Ykc2SUJxUUdxWDR4L2FFRjg1?= =?utf-8?B?STJwdkdBbk9qWndraW40cWFqOVdPTXUydFBJK0N0UCtKYnNSTnRLeWkvenkx?= =?utf-8?B?VDZJeFl2T3Z4SUlvL2p5TnA2RGhjZzRhWi9IRS9aSnFmQ2ZXTitmYll5S0h0?= =?utf-8?B?cFVjcjB1dm04bElOb3lqM0xFV003UFZsNWtTZDR4WFVlYzB2T1RTNk1Bb3lS?= =?utf-8?B?TXYwSEdMcWhNUTJWbTFhWVZROHV1TlpreklCdXRZandVcTRuUlZudi9VTmpB?= =?utf-8?B?eVl1ZUV5ZE5WVGtlQnBKa1ZlRWhEL0NveGJGWEJkZXpBaU91bFZNL1NwbGhi?= =?utf-8?B?dnVVUXNMbndYSHdRS0xleWRWNmJFQWl1VkdwOE1WL0NMUW56VW1uNG1YcUpK?= =?utf-8?B?RjVTMGVSaUxmM2pFY08xd2JIeG1nN3VEVGw0d3MzODZKRnk5anRJMzBLM1R6?= =?utf-8?B?QnphUTd0Q1FvSFRMaDhZZ01hNitCaXczZlVJYnJBMFlFM3VKOVd3ZTM5eHBy?= =?utf-8?B?MkdIZmNkMkFtSFhlbGRmcXYwaUN0TFQ4UkZlVW1YQWxLenYzcERCcHNTb2Ji?= =?utf-8?B?ektmTnVycTdNWlBLSUZtbFlhVndJVFhzN0ZadERjNldzT2F6a09wUT09?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: e8407d75-b5d0-4edb-7618-08dee9bdb76e X-MS-Exchange-CrossTenant-AuthSource: SN7PR12MB8131.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Jul 2026 19:56:56.9546 (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: thLtHHA683R9g18CSrffBlnGHkfYW7aZfDC6qRnzWGLL/r5AHnMfpXFHjepB6UDpHRPkDC1u0rJMKQpNswbqlA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR12MB7146 On 7/24/26 13:57, Brian Gerst wrote: > On Fri, Jul 24, 2026 at 12:42 PM Tom Lendacky wrote: >> >> On 7/23/26 22:02, Brian Gerst wrote: >>> The decrypted BSS section needs to be cleared after it is remapped as >>> decrypted memory. Separate it so that the normal BSS section can be >>> cleared earlier. >>> >>> Signed-off-by: Brian Gerst >>> --- >>> arch/x86/kernel/vmlinux.lds.S | 2 +- >>> arch/x86/mm/mem_encrypt_amd.c | 3 +++ >>> 2 files changed, 4 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S >>> index 2438b89a4620..e64c797e06c7 100644 >>> --- a/arch/x86/kernel/vmlinux.lds.S >>> +++ b/arch/x86/kernel/vmlinux.lds.S >>> @@ -365,9 +365,9 @@ SECTIONS >>> *(.bss..page_aligned) >>> . = ALIGN(PAGE_SIZE); >>> *(BSS_MAIN) >>> - BSS_DECRYPTED >>> . = ALIGN(PAGE_SIZE); >>> __bss_stop = .; >>> + BSS_DECRYPTED >>> } >>> >>> /* >>> diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c >>> index 2f8c32173972..d39e1e29bcb9 100644 >>> --- a/arch/x86/mm/mem_encrypt_amd.c >>> +++ b/arch/x86/mm/mem_encrypt_amd.c >>> @@ -479,6 +479,9 @@ void __init sme_early_init(void) >>> if (!sme_me_mask) >>> return; >>> >>> + memset(__start_bss_decrypted, 0, >>> + (unsigned long) __end_bss_decrypted - (unsigned long) __start_bss_decrypted); >>> + >> >> I think this section needs to be cleared to zero regardless of whether SME >> or SEV (this section is mainly used for SEV) is active. For example KVM >> clock makes use of this section even if SEV is not active. So this should >> probably live in clear_bss(), no? > > This is how I understand the current order: > - The bss_decrypted section gets encrypted in sme_encrypt_kernel() That is true for SME, yes, for SEV it is already encrypted so sme_encrypt_kernel() returns without doing anything. > because it's part of the final BSS section. > - It is then remapped as unencrypted in sme_postprocess_startup(). > - clear_bss() then clears it Yes. > > When clear_bss() is called first, remapping it as unencrypted > scrambles that memory so it needs to be cleared again after remapping. > I could unconditionally clear it in the same place clear_bss() is > called now and not have it depend on encryption being enabled The > other alternative would be for sme_encrypt_kernel() to skip it and > leave it as unencrypted from the beginning. The __bss_decrypted attribute will cause a variable to be put in the bss_decrypted section. The KVM clock support puts a structure in that section. If we look at a non-SEV guest with this patch, that means that the bss_decrypted section is not cleared at all and KVM clock is valid for a non-SEV guest. If you add clearing the bss_decrypted section in patch #1 and #2, then the change the change you make in patch #1 to sme_early_init() should actually be put in #2. In other words, you can make #1 a "no functional change" patch by just updating clear_bss() to clear both bss and bss_decrypted. When you move clear_bss() in patch #2, you can add the memset() in sme_early_init() you originally added in #1 to cover the case of the mapping change for SME and SEV. A comment above it along the lines of indicating that bss_decrypted is cleared before the actual mapping was updated to make it decrypted/shared, so clear it now. Thanks, Tom