From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (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 183A02DC764; Thu, 12 Mar 2026 22:44:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.177.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773355481; cv=fail; b=IBzY2d0tceV2/cWLdVfVXbu8oAndIO4+7PfgpO9jGCwFw3zaajfCBC6xFj2w7f13AnvRD0BhhzuDyxCATGsCYC8ANHiW5Nm9pIb3Z4mr4G8QmwSCL8f+268+N2JCCxXSPd0cJtZGmGe+7+/WMnU0v70w605qnPhwttTShScSwGg= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773355481; c=relaxed/simple; bh=ptYBTOgKb9wOuF5aEw51mGyv0P4sBhmfzSBNsB8cIvY=; h=Content-Type:Message-ID:Date:Subject:To:Cc:References:From: In-Reply-To:MIME-Version; b=b+dQess5ie/wJsLg0Cgi0pDg0h43dSe59LAybm++niJA7cxeOIMB1C+V3rd14LgNPUDftxSsraLZe4yeQNXi0MRMb+5C49PoCZoUtGHOYooKXyYCb8gjiGG++53ztVYRmQ1UdeHK05Jph9cuxBdBLwXEAfp+sfqT9ZiPgUnZWCs= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=TtJQXBzS; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=z305CYSO; arc=fail smtp.client-ip=205.220.177.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="TtJQXBzS"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="z305CYSO" Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 62CLHUQm2144624; Thu, 12 Mar 2026 22:44:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=FDW4+b0iksKXfV1Mwb TVshEJNPaigFiDuJo2z5Nkzn4=; b=TtJQXBzSgDvY1Nst0IDY2q0ZH9FM9+KTiE 0uFR/zFZ8nQCCRrz2lw2YgZd4zNbWUZDsKPDGVKt+njUTz9z7fMBZOGelvaLZdxb R//8TsD7hPFi6oHxta/gXKcErrI+jWArocMO6m/q+svL8VIXW1QgojEXA9GHVlq+ NFA9GGo3GV/urHIeKiuyFbmwvtSIwYKE028BO/fhxbEd9xgF9eI/p62mskEtBpbo YL8E0au9uIybH0v1xl+sl1A6ZDYqsGXdSEMLp+QvECdgkkaV+UmRPpIluPCGTPSa WFKGyYLAipKXG1MlVTXkZhD/I4quqPWWa01I0eEYHdef8ZIXWLgg== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 4cuh4qsw47-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Mar 2026 22:44:12 +0000 (GMT) Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 62CMLB3f024073; Thu, 12 Mar 2026 22:44:12 GMT Received: from ph7pr06cu001.outbound.protection.outlook.com (mail-westus3azon11010041.outbound.protection.outlook.com [52.101.201.41]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 4cuh5gdywu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Mar 2026 22:44:11 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=tWhplNlyNKtaq+w5J7p8LTgAaI6ksDgmB0/K8oL4pi5wzeKXSBEo+N5jVChAQhgkGrJ/b8g0XeSRQhRdPjJTlYZOkhGLEcqIrRCnLbuFybejo9vjzoycKXOq6m7pwU7MfoKtAm2TUzE10kka4W+8xSnGTDcAPqZ6sjKNpn8XGGZQNDPskKFcoFVeNo/c6Fc2bNb0uYoSZanITPDFa1xqq0qYO2cfb7ITKHTxrwIm3kbpgDfb0YNLrZTyAICehDLPvLE+8j7OVVMlPxGxVHN9JDUhjs0bDktBGRK8HSKpjmqTpSruyBhdQctqTXJ8W1I4uaS3qBybthPbiT4yLX0n2g== 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=FDW4+b0iksKXfV1MwbTVshEJNPaigFiDuJo2z5Nkzn4=; b=w/3EqGyRi+exSbU0sW6N6IksoSHOsK7ISTGrPyJppNIemH7sQkct5ar4/AOy3VhBnSLXkQEax4O4Jqhy7WDacQuwCmJOLyLftVTK6giJkvyEBWFA9P4KaINltquUmVbjS9zJe89Iu3hB+OtNZKy6R1CCDD/ARft/ZeAFzTsRQrV5peT7tg9VQkpBVBGdJoO+tce4PPIGBGN7YqmZ8SUv5uBJH5FLw0YunMT0xf3nj0CuKbxwRJ6jGdV20cIsg/0r074BeAMgfSkUCUac1VRH0BgPHY03P+Lr1RWvh36OqA0FiJ2FfJMgzTZglcWsX9E07I0STzfZZd13Fj/QojmOIQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=FDW4+b0iksKXfV1MwbTVshEJNPaigFiDuJo2z5Nkzn4=; b=z305CYSOXW2NrZURHbBWCL3mQTHxrxXIO25YncS5yd2suPQsDbG+6BRQ/hokGBXJQtZ3gOMQ6srKhjaNFjCfvywk1BSXlDkJK4B/j2QwamWemlq/+elHq2HZV+9kIUn7LgN67I/oY/NpzC57JUEfqYzrswA4aG1oPFarrc/0u4k= Received: from CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) by SA1PR10MB7633.namprd10.prod.outlook.com (2603:10b6:806:375::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9700.16; Thu, 12 Mar 2026 22:44:09 +0000 Received: from CH3PR10MB7329.namprd10.prod.outlook.com ([fe80::c2a4:fdda:f0c2:6f71]) by CH3PR10MB7329.namprd10.prod.outlook.com ([fe80::c2a4:fdda:f0c2:6f71%7]) with mapi id 15.20.9700.015; Thu, 12 Mar 2026 22:44:08 +0000 Content-Type: multipart/mixed; boundary="------------hgRvAjcSRhNkYEg62iVQ0vZZ" Message-ID: Date: Thu, 12 Mar 2026 23:44:04 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/1] x86/mce/amd: Fix VM crash during deferred error handling To: Borislav Petkov , yazen.ghannam@amd.com Cc: tony.luck@intel.com, tglx@kernel.org, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org, John.Allen@amd.com, jane.chu@oracle.com References: <20260218163025.1316501-1-william.roche@oracle.com> <20260218163025.1316501-2-william.roche@oracle.com> <20260312144203.GCabLQuwFySHkkCyBO@fat_crate.local> <8e35298b-7511-4f7f-8f13-9b03738b286c@oracle.com> <20260312160453.GDabLkJfhslCLXZntv@fat_crate.local> Content-Language: en-US From: William Roche In-Reply-To: <20260312160453.GDabLkJfhslCLXZntv@fat_crate.local> X-ClientProxiedBy: FR4P281CA0326.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:eb::19) To CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) 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: CH3PR10MB7329:EE_|SA1PR10MB7633:EE_ X-MS-Office365-Filtering-Correlation-Id: 7efe788a-847e-4201-c139-08de8088df4f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|6049299003|1800799024|376014|366016|18002099003|56012099003|22082099003|4053099003; 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:CH3PR10MB7329.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(6049299003)(1800799024)(376014)(366016)(18002099003)(56012099003)(22082099003)(4053099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ZkpudWVZcE0raTRaNzRVZ2RGS29peFlqWjc2ZkhHMUVhT0FYQWJCcUR3SzNa?= =?utf-8?B?MmtwMExrcW55Nm5zZkN5TE41Rm5JVDVXbGh1NGRaM3EzeHE1NWExU3BEbjM0?= =?utf-8?B?Nm5GMTJTeS9nNnUrQlZ3ZVhRaTVKb1U5TVo3ck5HR2Z6NHAyeDlDejNIS29Y?= =?utf-8?B?Zi9GM25ZQW4rYlhuUSs3UUozUElJT085R3hXT1VLOVJkS01TOUlQeWUvcWtp?= =?utf-8?B?b1JYenhPeUNEUzkxOE96VXlyMkljdlN2ZlpOVVdFU1picFhBN0szYjlhcEVS?= =?utf-8?B?WER0WmhnNEpVL2I2RXM2YStxQyt1VmRlYWpUVjVoN3c2Ym1LUUEzUFRncnRt?= =?utf-8?B?RFEyMlI2V3lSdUZZVVQxVGNVeGkrY3AzeWJXUWZIRjAzcmFvNUJtR2loYitQ?= =?utf-8?B?Vk5lUEVQSHFWdXNFeXpqeEdiMUhKMUN1eVdKRmFPcWMvZzJ1K3B3V1cwOW53?= =?utf-8?B?WjFFTmdnZUlpWmh0M3o2ekJRK3BNbFJmUEQvMUFZdlVKUXVGQVVDOWQ5SGg2?= =?utf-8?B?NTZnc1VpSzc4UXFKazBtUUJvVGwvVW5UbkpXUHgyVWJYd2NGTFA2ZW5aZTM1?= =?utf-8?B?VHlLTXluQXNyYUNlMXRpTUxiNms5cFJvb0p5a3RCbVBRbnJUVUhITkxwNUxW?= =?utf-8?B?S1FyM2V2cGFXeEtXN0tuM0tCbC9NV3N5dlJrQ3NheWxSRlB4eUNqK2laL0xl?= =?utf-8?B?NTBvRmhmdDVseUV2ODVBbmNCbFhReE5oWUdGRWRhV2lnYkdaNW1WanFXN3pu?= =?utf-8?B?WUxyNlU0K2FGY3h4VWdDc2g3dThKZTd4cG8xQkFuSEpkUFVGUWNEOUVTNW5o?= =?utf-8?B?aWczcjdzUndlVE1uSGtHeUV3TGtBVnRPcFVIQ09hVzVvUXBIWW1kNDBjWWpK?= =?utf-8?B?dHZJbmVmenZRUGQ4eGFiVjZFdmxhTTNIYlpiNkV1b0VRMkt5ZmZFaTRlNUpj?= =?utf-8?B?MlBtTUowdE9IT1cyK1Q3TWxrc090QXRCZGI4TGNqNWxWY2VCbnp6UU5OWTZp?= =?utf-8?B?WGVjVTdUNHFPSklCK2JvN3dpSDFIbmNUaVdoVTdjSlFWRDQ4YjNUR1N6K0M5?= =?utf-8?B?Tk1PZ3FkZ25GN1p6N0FPNU9yZEFYM2J5elNld2VLb1pabVZkNDAxWmdPcnV2?= =?utf-8?B?aEdVcDE3NnNIRWU3MTRYeWcxQ1ZrMjFWZzZrRlh3WkdZblJ4TDJRaDhGMkNH?= =?utf-8?B?bGpxVnFma3MySDFpYmp6TVBUMWpFOWFMWWVsQzZSMUN5S0g1U1lya245aDVR?= =?utf-8?B?Y1AvWDBGK1Y0TlFKKzh3WTFBWExvMUtpYS90Vm9MUmJvUWVpQU5FMmJZNDNw?= =?utf-8?B?UnZHVkpnZUFIUWFwVWJNR2wxSUczd0UzL3g4SERjdGxyRHpEa3Z3enQxMUdF?= =?utf-8?B?U1pkSjBEQXE2SU8yTy9STzVFR1liWmZLRVNuL1RzUkppNzl3TG1RdVBOSzQ1?= =?utf-8?B?MzNNTHEybWVqMStsRU9DakxReC8vRS9EZG43KzdwVWE4Z1U2UUlNOFgzdVFt?= =?utf-8?B?QTFPOXdyc3RhUGZDbmtBUlpUMjR3bG54cXlTVTRMbWNLZmpOYUc1a3YwUks0?= =?utf-8?B?UTJFdjFKZjlveDA3QWZmUTJUYWpITGNmb0pBYVZwMnNxTXVaNitab3BUMW9D?= =?utf-8?B?SHdEdDRheVFFVWJ1TUhSaUJoMURGWGNQWFNIU1hYNzJsSjFrNGlhdEpmdDdu?= =?utf-8?B?TUNkd1oxK05ZcnBabUQzZURUclh1dHF3amxqbTAzWHVESHp0RGlnK0dyb3du?= =?utf-8?B?YzlWaXhJdHk5RXhKcnVzR2RIS1JvdzF3Q1Z5czU3MzBuVHQxLy9hdUJsNFAx?= =?utf-8?B?dk1IWVlRWkJybmc3MDRSSFdtam03Z0Rtd1NLVXJFdXA4SEVPc3luL0VXL3gv?= =?utf-8?B?N3UzS0lSZkRmc2dzOUozMFdZYTByV3cwOTdLZ0djcURKL3JQc3pXalYreDZJ?= =?utf-8?B?cEMwUTJGYkdVajBVV2R2bU52KzAyOUltazNjK3dXbmhjNWtoYmRCRXlCYThu?= =?utf-8?B?N0hiZ1M4NmdBRzRxSko2dmZBVG1sS0RwaW4xMGRGdGp5Q1hWMzNsdkxsVkwy?= =?utf-8?B?cElLcFJUREpVckxYVk1GUG15ZEdlWkZKWDl5UGFMdTJibzMyNUtTc3NUbi8r?= =?utf-8?B?NUZxR0xSQlNqS1dMVGZ2dXBEZGN1Q0E3MlcvYTBiS05MMXZqRFEwT2F5Y29w?= =?utf-8?B?UlFNbmtUam9CbU5yeGdjVzE0TFRBbEpTS1lyNnJGOElzanRDeFl0bElPdUU5?= =?utf-8?B?OVMyanFIN01VZFY0SzV3by94K3ZDK3pCTU9wdmtxbmdHbGhCandDNWM2ZGFD?= =?utf-8?B?T0NsQktJK0ZPeXdoMnNTSkVFNnZxWlN2NmE4QVFaZm1PV09KeDNQWmJWS0pJ?= =?utf-8?Q?wBkYTZWjjarAZECE=3D?= X-Exchange-RoutingPolicyChecked: uOZWY3Rt61g1jP+z2OYzR5pwrsCMIoNk8YsNqJI/UZH4if9obOt9jV3Rpb4u6PKtY/UcV+vy1967tMLhPW0cqypW7MW+HXfegXbdOJLGlCS3G3BJKb7kZcpOz4Z4U84BUHXfxkkm81esZM+sEPIvPZsYksRVzUXTxC7BHNpofvw1NHhc3SsUpAwfdvjTK4jtOB1WNSN/09hW37IB2VuUIRrHF7SV+Nh+qlDYncA74gWVg99Bc1j9w7auXV0uAFi/cJdUxox3Y/icm3+wV2E21CFcuDLFGSPp0jzJo1n/p6DYqA7epcQLSV00tjzrQV9JgiYPEMYKis6LYksptOMRVg== X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 7efe788a-847e-4201-c139-08de8088df4f X-MS-Exchange-CrossTenant-AuthSource: CH3PR10MB7329.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Mar 2026 22:44:08.6974 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: pbunBmwsG8NAAGlNSIqtGXWuKtSbEbW1ewaNDu4utod2zPFJd+zWmh5U+DTiuy14lviPVjFy58f1gH4mQnNiMf+LgSrox2OppTA4vu47bOc= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR10MB7633 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-03-12_03,2026-03-12_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxlogscore=999 suspectscore=0 malwarescore=0 bulkscore=0 adultscore=0 phishscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2603050001 definitions=main-2603120183 X-Proofpoint-GUID: giNuPDu_Qwz0kx9wis9Z3Y2gAMZWw606 X-Authority-Analysis: v=2.4 cv=ZdsQ98VA c=1 sm=1 tr=0 ts=69b341bd b=1 cx=c_pps a=WeWmnZmh0fydH62SvGsd2A==:117 a=WeWmnZmh0fydH62SvGsd2A==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=xqWC_Br6kY4A:10 a=Yq5XynenixoA:10 a=GoEa3M9JfhUA:10 a=VkNPw1HP01LnGYTKEx00:22 a=jiCTI4zE5U7BLdzWsZGv:22 a=3I1J8UUJPc9JN9BFgKH3:22 a=WUd-ur9-quosQU6NfBkA:9 a=QEXdDO2ut3YA:10 a=ICJoR34Z0lMm7dEa-HUA:9 a=JMNH9X61SiQA:10 X-Proofpoint-ORIG-GUID: giNuPDu_Qwz0kx9wis9Z3Y2gAMZWw606 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMzEyMDE4MiBTYWx0ZWRfXypk3E3ce9U2h zdW9PMAcYgkT5cnmnqXROpmFCe4yZ+XW0cOGml/OzeVXOoTIysEf5ljzI4rrCH15i2Wvbx8QGTE RUaJnr+Qo4gupDSxgD1voUhaO3fCCWBZG3VjDjKoSyfElg7qP/99cvWPzMXkFhDmQeQFg8s68Us sOl239F0mcqzamiotKQwuoLRlWNtanyh/UsAG63inqWaVkdZ8JNRTck224k3fX9ewdWOXmCEJ0i R+YakG2xwn/Kq45bTHnxoYxXxdIoKaRJcNI29q6Zl7le/GwapkFxH/KbInP74u45CLmcIVsrI+O pmAEzJ6Bn9YXO25ajU50piik9JGpTCGPTUz7bHT/v582qj7EDPXaAA2jBQNLp2ewLPDwyGGERIP mLkv7rJ4mewFtvvP5sJ9AKRf4wxFlosQkCx4eu2UAUt6Mezu1Odkl/hSQTcrwgS65luGV96vsQb Ue4ZNrWfh1oXGiJ4Rcw== --------------hgRvAjcSRhNkYEg62iVQ0vZZ Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Thank you for taking the time to explain your worries about the context of this fix integration, and I do hope my feedback can help to convince you. On 3/12/26 17:04, Borislav Petkov wrote: > On Thu, Mar 12, 2026 at 04:11:10PM +0100, William Roche wrote: >> From the kernel point of view (regardless if it is running on bare metal or >> in a VM), access to these registers registers is provided by the platform: >> either the Hardware or the emulation framework. > > Except the emulation doesn't emulate the platform properly. We test on real > hw. If your hypervisor doesn't do that properly then that's not really > upstream kernel's problem. There are several aspects that are worth considering here: First, I totally agree that the emulation has to emulate properly ! :) The problem we are facing is to consider non-SMCA platform reaction to updating and SMCA specific register. And is the QEMU/KVM VM reaction as a non-SCMA machine a valid case ? In this VM case, the MSR handling emulation is done by KVM which doesn't implement a "permissive" access to unimplemented registers. I also agreed with you when you said that it is working as advertised. Now if emulating an AMD platform requires to provide a "permissive" access to a specific set of registers, the fix would not be absolutely necessary. But I may have missed a specification about that. And if such a thing exists, it would also be all kernels (including upstream) responsibility to take that into account. Yazen may help us on this aspect: Could you please let us know if there is an AMD specification for accessing SMCA registers on non SMCA machines ? Now if we had a valid case of an existing non-SMCA AMD hardware that could crash on updating an SMCA register, the fix would be needed not only for the VM case. Yazen, could you also please tell us if an existing non-SMCA AMD hardware could crash on updating an SMCA register ? The commit 7cb735d7c0cb [x86/mce: Unify AMD DFR handler with MCA Polling] written by Yazen, introduced an upstream kernel problem on non-SMCA platforms that has been revealed by the emulation framework on AMD. That's the reason why I think it should be fixed in upstream too. And Yazen himself agrees with that. > >> Errors are injected into VMs by the hypervisor when real memory hardware >> errors occur on the system that impact the VM address space. > > And? The injected error is received by the VM kernel to deal with it. > Why? The VM kernel executes the same mechanisms used on bare metal in that case. As Tony said on Feb 9: The guest may be able to just kill a process and keep running. > > What's the recovery action scenario for having errors injected into guests? Just the same as running on real HW. > Where is that documented? Why does the upstream kernel need to care? Sorry I don't have a kernel documentation pointer about that, but the MCE relay mechanism sure is an Hypervisor functionality. > > Basically I'm asking you for the use case in order to determine whether that > use case is valid for the *upstream* kernel to support. Yes, of course, see below. > >> This is not only a test, this is real life mechanism. With the fix >> 7cb735d7c0cb that has been integrated, VMs kernel running on AMD now crashes >> on Deferred errors, where it used to be able to deal with them before this >> commit. > > Because we don't know of your use case. So when we do upstream development how > can we test your case? > I have a procedure to verify the behavior: It consists of running the upstream kernel in a VM (on an AMD platform) and injecting a memory error from the hardware platform to this VM to mimic a real hardware error being reported to the platform Kernel. To do so: Run Qemu as root (to help with the address translation). The VM runs the upstream kernel. Run the small attached program in the VM as root, so that it gives a guest physical address of one of its mapped memory page. [root@VM]# ./mce_process_react_x86 Setting Early kill... Ok Data pages at 0xXXXXXXX physically 0xYYYYY000 -> DON'T Press enter ! (just leave the process wait here) Ask the emulator (QEMU in this case) to give the host physical address of the guest physical page: (qemu) gpa2hpa 0xYYYYY000 Host physical address for 0xYYYYY000 (pc.ram) is 0xPFN000 From the host physical address get the pfn value (removing the last 3 zeros of the address) to poison. On the host, use hwpoison kernel module: [root@host]# modprobe hwpoison_inject and inject an error to the targeted pfn: [root@host]# echo 0xPFN > /sys/kernel/debug/hwpoison/corrupt-pfn Than wait until the Asynchronous error generated reaches the VM (it can take up to 5 minutes on AMD virtualization) to see the VM kernel deal with it. Without this suggested fix, the VM kernel panics, with the stack trace I gave: mce: MSR access error: WRMSR to 0xc0002098 (tried to write 0x0000000000000000) at rIP: 0xffffffff8229894d (mce_wrmsrq+0x1d/0x60) amd_clear_bank+0x6e/0x70 machine_check_poll+0x228/0x2e0 ? __pfx_mce_timer_fn+0x10/0x10 mce_timer_fn+0xb1/0x130 ? __pfx_mce_timer_fn+0x10/0x10 call_timer_fn+0x26/0x120 __run_timers+0x202/0x290 run_timer_softirq+0x49/0x100 handle_softirqs+0xeb/0x2c0 __irq_exit_rcu+0xda/0x100 sysvec_apic_timer_interrupt+0x71/0x90 [...] Kernel panic - not syncing: MCA architectural violation! With the fix the VM Kernel deals with the error: [root@VM]# ./mce_process_react_x86 Setting Early kill... Ok Data pages at 0x7fa0f9b25000 physically 0x172929000 (qemu) gpa2hpa 0x172929000 Host physical address for 0x172929000 (pc.ram) is 0x237129000 -> Injecting the error with: [root@host]# echo 0x237129 > /sys/kernel/debug/hwpoison/corrupt-pfn -> The VM monitor indicates: qemu-kvm: warning: Guest MCE Memory Error at QEMU addr 0x7f3ae2729000 and GUEST addr 0x172929000 of type BUS_MCEERR_AO injected -> A few minutes later, the VM console shows: localhost login: [ 332.973864] mce: [Hardware Error]: Machine check events logged [ 332.976795] Memory failure: 0x172929: Sending SIGBUS to mce_process_rea:5607 due to hardware memory corruption [ 332.977832] Memory failure: 0x172929: recovery action for dirty LRU page: Recovered [ 355.056785] MCE: Killing mce_process_rea:5607 due to hardware memory corruption fault at 0x7fa0f9b25000 -> The process shows: Signal 7 received: BUS_MCEERR_AO on vaddr: 0x7fa0f9b25000 Signal 7 received: BUS_MCEERR_AR on vaddr: 0x7fa0f9b25000 Exit from the signal handler on BUS_MCEERR_AR -> Works as expected: AO error is relayed by the VM kernel to the application running. > Before that, is that case even worth testing? If we accept that relayed MCEs is supported by the upstream kernel running in the VM, than yes. > > I hope I'm making sense here. The MCA and other low-level hw code works on > baremetal as that's its main target. If it is supposed to work in VMs, then > there better be a proper use case which we are willing to support and we can > *actually* *test*. The above detailed procedure can maybe help with this aspect, even if it is virtualization oriented. As I do hope that upstream kernel supports memory error handling in a VM. But Yazen's answers about non-SMCA hardware can also help to decide what to do with this fix. > > If not, you can keep this "fix" in your guest kernels and everyone's happy. > > Thx. I hope my explanations helped to better understand the context. Thanks, William. --------------hgRvAjcSRhNkYEg62iVQ0vZZ Content-Type: text/x-csrc; charset=UTF-8; name="mce_process_react.c" Content-Disposition: attachment; filename="mce_process_react.c" Content-Transfer-Encoding: base64 I2luY2x1ZGUgPHN5cy90eXBlcy5oPgojaW5jbHVkZSA8c3lzL3ByY3RsLmg+CiNpbmNsdWRlIDxz eXMvbW1hbi5oPgojaW5jbHVkZSA8c3RkaW8uaD4KI2luY2x1ZGUgPHN0ZGxpYi5oPgojaW5jbHVk ZSA8dW5pc3RkLmg+CiNpbmNsdWRlIDxzdGRpbnQuaD4KI2luY2x1ZGUgPHNpZ25hbC5oPgojaW5j bHVkZSA8c3RyaW5nLmg+CgojZGVmaW5lIFBBR0VNQVBfRU5UUlkgOAojZGVmaW5lIEdFVF9CSVQo WCxZKSAoWCAmICgodWludDY0X3QpMTw8WSkpID4+IFkKI2RlZmluZSBHRVRfUEZOKFgpIFggJiAw eDdGRkZGRkZGRkZGRkZGCgpjb25zdCBpbnQgX19lbmRpYW5fYml0ID0gMTsKI2RlZmluZSBpc19i aWdlbmRpYW4oKSAoICgqKGNoYXIqKSZfX2VuZGlhbl9iaXQpID09IDAgKQpzdGF0aWMgbG9uZyBw Z3N6OwoKLyoKICogU2V0IHRoZSBlYXJseSBraWxsIG1vZGUgcmVhY3Rpb24gc3RhdGUgdG8gTUNF IGVycm9yLgogKi8Kc3RhdGljIHZvaWQgZWFybHlfcmVhY3Rpb24oKSB7CiAgIHByaW50ZigiU2V0 dGluZyBFYXJseSBraWxsLi4uICIpOwogICBpZiAocHJjdGwoUFJfTUNFX0tJTEwsIFBSX01DRV9L SUxMX1NFVCwgUFJfTUNFX0tJTExfRUFSTFksIDAsIDApID09IDApCiAgICAgIHByaW50ZigiT2tc biIpOwogICBlbHNlCiAgICAgIHByaW50ZigiRmFpbHVyZSAhXG4iKTsKfQoKLyoKICogUmV0dXJu IHRoZSBwaHlzaWNhbCBhZGRyZXNzIGFzc29jaWF0ZWQgdG8gYSBnaXZlbiBsb2NhbCB2aXJ0dWFs IGFkZHJlc3MsCiAqIG9yIC0xIGluIGNhc2Ugb2YgYW4gZXJyb3IuCiAqLwpzdGF0aWMgdWludDY0 X3QgcGh5c2ljYWxfYWRkcmVzcyh1aW50NjRfdCB2aXJ0X2FkZHIpIHsKICAgY2hhciBwYXRoX2J1 ZiBbMHgxMDBdOwogICBGSUxFICogZjsKICAgdWludDY0X3QgcmVhZF92YWwsIGZpbGVfb2Zmc2V0 LCBwZm4gPSAwOwogICB1bnNpZ25lZCBjaGFyIGNfYnVmW1BBR0VNQVBfRU5UUlldOwogICBwaWRf dCBteV9waWQgPSBnZXRwaWQoKTsKICAgaW50IHN0YXR1cywgaTsKCiAgIHNwcmludGYocGF0aF9i dWYsICIvcHJvYy8ldS9wYWdlbWFwIiwgbXlfcGlkKTsKICAgCiAgIGYgPSBmb3BlbihwYXRoX2J1 ZiwgInJiIik7CiAgIGlmKCFmKXsKICAgICAgcHJpbnRmKCJFcnJvciEgQ2Fubm90IG9wZW4gJXNc biIsIHBhdGhfYnVmKTsKICAgICAgcmV0dXJuICh1aW50NjRfdCktMTsKICAgfQogICAKICAgZmls ZV9vZmZzZXQgPSB2aXJ0X2FkZHIgLyAodWludDY0X3QpcGdzeiAqIFBBR0VNQVBfRU5UUlk7CiAg IHN0YXR1cyA9IGZzZWVrKGYsIChsb25nKWZpbGVfb2Zmc2V0LCBTRUVLX1NFVCk7CiAgIGlmKHN0 YXR1cyl7CiAgICAgIHBlcnJvcigiRmFpbGVkIHRvIGRvIGZzZWVrISIpOwogICAgICBmY2xvc2Uo Zik7CiAgICAgIHJldHVybiAodWludDY0X3QpLTE7CiAgIH0KCiAgIGZvcihpPTA7IGkgPCBQQUdF TUFQX0VOVFJZOyBpKyspewogICAgICBpbnQgYyA9IGdldGMoZik7CiAgICAgIGlmKGM9PUVPRil7 CiAgICAgICAgIGZjbG9zZShmKTsKICAgICAgICAgcmV0dXJuICh1aW50NjRfdCktMTsKICAgICAg fQogICAgICBpZihpc19iaWdlbmRpYW4oKSkKICAgICAgICAgICBjX2J1ZltpXSA9ICh1bnNpZ25l ZCBjaGFyKWM7CiAgICAgIGVsc2UKICAgICAgICAgICBjX2J1ZltQQUdFTUFQX0VOVFJZIC0gaSAt IDFdID0gKHVuc2lnbmVkIGNoYXIpYzsKICAgfQogICBmY2xvc2UoZik7CgogICByZWFkX3ZhbCA9 IDA7CiAgIGZvcihpPTA7IGkgPCBQQUdFTUFQX0VOVFJZOyBpKyspewogICAgICByZWFkX3ZhbCA9 IChyZWFkX3ZhbCA8PCA4KSArIGNfYnVmW2ldOwogICB9CgogICBpZihHRVRfQklUKHJlYWRfdmFs LCA2MykpIHsKICAgICAgcGZuID0gR0VUX1BGTihyZWFkX3ZhbCk7CiAgIH0gZWxzZSB7CiAgICAg IHByaW50ZigiUGFnZSBub3QgcHJlc2VudCAhXG4iKTsKICAgfQogICBpZihHRVRfQklUKHJlYWRf dmFsLCA2MikpCiAgICAgIHByaW50ZigiUGFnZSBzd2FwcGVkXG4iKTsKCiAgIGlmIChwZm4gPT0g MCkKICAgICAgcmV0dXJuICh1aW50NjRfdCktMTsKCiAgIHJldHVybiBwZm4gKiAodWludDY0X3Qp cGdzejsKfQoKLyoKICogU0lHQlVTIGhhbmRsZXIgdG8gZGlzcGxheSB0aGUgZ2l2ZW4gaW5mb3Jt YXRpb24uCiAqLwpzdGF0aWMgdm9pZCBzaWdidXNfYWN0aW9uKGludCBzaWdudW0sIHNpZ2luZm9f dCAqc2lnaW5mbywgdm9pZCAqY3R4KSB7CiAgIHByaW50ZigiU2lnbmFsICVkIHJlY2VpdmVkOiAi LCBzaWdudW0pOwogICBwcmludGYoIiVzIG9uIHZhZGRyOiAlcFxuIiwKICAgICAgKHNpZ2luZm8t PnNpX2NvZGUgPT0gND8gIkJVU19NQ0VFUlJfQVIiOiJCVVNfTUNFRVJSX0FPIiksCiAgICAgIHNp Z2luZm8tPnNpX2FkZHIpOwoKICBpZiAoc2lnaW5mby0+c2lfY29kZSA9PSA0KSB7IC8qIEJVU19N Q0VFUlJfQVIgKi8KCWZwcmludGYoc3RkZXJyLCAiRXhpdCBmcm9tIHRoZSBzaWduYWwgaGFuZGxl ciBvbiBCVVNfTUNFRVJSX0FSXG4iKTsKCV9leGl0KDEpOwogIH0KfQoKaW50IG1haW4oaW50IGFy Z2MsIGNoYXIgKiogYXJndikgewogICBzdHJ1Y3Qgc2lnYWN0aW9uIG15X3NpZ2FjdGlvbjsKICAg dWludDY0X3QgdmlydF9hZGRyID0gMCwgcGh5c19hZGRyOwogICB2b2lkICpsb2NhbF9wbnQ7Cgog ICAvLyBOZWVkIHRvIGhhdmUgdGhlIENBUF9TWVNfQURNSU4gY2FwYWJpbGl0eSB0byBnZXQgUEZO cyB2YWx1ZXMgaW4gcGFnZW1hcC4KICAgaWYgKGdldHVpZCgpICE9IDApIHsKICAgICAgZnByaW50 ZihzdGRlcnIsICJVc2FnZTogJXMgbmVlZHMgdG8gcnVuIGFzIHJvb3RcbiIsIGFyZ3ZbMF0pOwog ICAgICBleGl0KEVYSVRfRkFJTFVSRSk7CiAgIH0KCiAgIC8vIGF0dGFjaCBvdXIgU0lHQlVTIGhh bmRsZXIuCiAgIG1lbXNldCgmbXlfc2lnYWN0aW9uLCAwLCBzaXplb2YobXlfc2lnYWN0aW9uKSk7 CiAgIG15X3NpZ2FjdGlvbi5zYV9zaWdhY3Rpb24gPSBzaWdidXNfYWN0aW9uOwogICBteV9zaWdh Y3Rpb24uc2FfZmxhZ3MgPSBTQV9TSUdJTkZPIHwgU0FfTk9ERUZFUjsKICAgc2lnZW1wdHlzZXQo Jm15X3NpZ2FjdGlvbi5zYV9tYXNrKTsKICAgaWYgKHNpZ2FjdGlvbihTSUdCVVMsICZteV9zaWdh Y3Rpb24sIE5VTEwpID09IC0xKSB7CiAgICAgIHBlcnJvcigiU2lnbmFsIGhhbmRsZXIgYXR0YWNo IGZhaWxlZCIpOwogICAgICBleGl0KEVYSVRfRkFJTFVSRSk7CiAgIH0KCiAgIHBnc3ogPSBzeXNj b25mKF9TQ19QQUdFU0laRSk7CiAgIGlmIChwZ3N6ID09IC0xKSB7CgkgICBwZXJyb3IoInN5c2Nv bmYoX1NDX1BBR0VTSVpFKSIpOwoJICAgZXhpdChFWElUX0ZBSUxVUkUpOwogICB9CiAgIGVhcmx5 X3JlYWN0aW9uKCk7CgogICAvLyBBbGxvY2F0ZSBhIHByaXZhdGUgcGFnZS4KICAgbG9jYWxfcG50 ID0gbW1hcChOVUxMLCBwZ3N6LCBQUk9UX1JFQUR8UFJPVF9XUklURSwgTUFQX0FOT058TUFQX1BS SVZBVEUsIC0xLCAwKTsKICAgaWYgKGxvY2FsX3BudCA9PSBNQVBfRkFJTEVEKSB7CiAgICAgIGZw cmludGYoc3RkZXJyLCAiTWVtb3J5IEFsbG9jYXRpb24gZmFpbGVkICFcbiIpOwogICAgICBleGl0 KEVYSVRfRkFJTFVSRSk7CiAgIH0KICAgdmlydF9hZGRyID0gKHVpbnQ2NF90KWxvY2FsX3BudDsK CiAgIC8vIERpcnR5IC8gbWFwIHRoZSBwYWdlLgogICBzcHJpbnRmKChjaGFyICopbG9jYWxfcG50 LCAiTXkgcGFnZVxuIik7CgogICBwaHlzX2FkZHIgPSBwaHlzaWNhbF9hZGRyZXNzKHZpcnRfYWRk cik7CiAgIGlmIChwaHlzX2FkZHIgPT0gLTEpIHsKICAgICAgZnByaW50ZihzdGRlcnIsICJWaXJ0 dWFsIGFkZHJlc3MgdHJhbnNsYXRpb24gMHglbGx4IGZhaWxlZFxuIiwgCiAgICAgICAgICh1bnNp Z25lZCBsb25nIGxvbmcpdmlydF9hZGRyKTsKICAgICAgZXhpdChFWElUX0ZBSUxVUkUpOwogICB9 CiAgIHByaW50ZigiXG5EYXRhIHBhZ2VzIGF0IDB4JWxseCAgcGh5c2ljYWxseSAweCVsbHhcbiIs CiAgICAgICh1bnNpZ25lZCBsb25nIGxvbmcpdmlydF9hZGRyLCAodW5zaWduZWQgbG9uZyBsb25n KXBoeXNfYWRkcik7CiAgIGZmbHVzaChzdGRvdXQpOwoKICAgcHJpbnRmKCJcblByZXNzIEVOVEVS IHRvIGNvbnRpbnVlXG4iKTsKICAgZmdldGMoc3RkaW4pOwogICAKICAgLy8gcmVhZCB0aGUgc3Ry aW5nIGF0IHRoZSBiZWdpbm5pbmcgb2YgcGFnZS4KICAgcHJpbnRmKCIlcyIsIChjaGFyICopbG9j YWxfcG50KTsKCiAgIHBoeXNfYWRkciA9IHBoeXNpY2FsX2FkZHJlc3ModmlydF9hZGRyKTsKICAg aWYgKHBoeXNfYWRkciA9PSAtMSkgewogICAgICBmcHJpbnRmKHN0ZGVyciwgIlZpcnR1YWwgYWRk cmVzcyB0cmFuc2xhdGlvbiAweCVsbHggZmFpbGVkXG4iLCAKICAgICAgICAgKHVuc2lnbmVkIGxv bmcgbG9uZyl2aXJ0X2FkZHIpOwogICB9IGVsc2UgewogICAgICBwcmludGYoIlxuRGF0YSBwYWdl cyBhdCAweCVsbHggIHBoeXNpY2FsbHkgMHglbGx4XG4iLAogICAgICAgICAodW5zaWduZWQgbG9u ZyBsb25nKXZpcnRfYWRkciwgKHVuc2lnbmVkIGxvbmcgbG9uZylwaHlzX2FkZHIpOwogICB9Cgog ICByZXR1cm4gMDsKfQo= --------------hgRvAjcSRhNkYEg62iVQ0vZZ--