From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2049.outbound.protection.outlook.com [40.107.243.49]) (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 E68842E630 for ; Wed, 23 Jul 2025 19:46:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.243.49 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753300008; cv=fail; b=Cp2RBiAzphPYBzFV+uagBAL9sEfaYIzLE9pB6eTjzMqvwzTuNEDH5tzD6SFWhxU/hUYYb+tY1ObH9FfTof+SDTZiVfRIGl2oHQcevp6322TFruSv0y1yVkUw9Nx5M0ZoDY0WZKZdB5alGgtJbop8/UY4ux8MNhSBvnr1qoT0IJ0= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753300008; c=relaxed/simple; bh=wOSShY+n+gjJDko7lvSj64yg6r9lzQFfhma2TaVOjec=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=eKO+7RgD2+W0Zj4Y4uXukq2iVen99G0E3zXW6U6COa3azbqpbumACBIKJXKqrN11+LNmaXz//szoW9ha7rpLiw30y8W3QKYjgr688FLb3YAYnZatBWEWP2LRtS44puSQW6vIn8KBUUO5kkZ+Fo3+oz2m37EIJkKZf8b/wubw2Jw= 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=v5MdVD98; arc=fail smtp.client-ip=40.107.243.49 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="v5MdVD98" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=hNnb5vwPy1Kbb91tOJPfXxjbm/aBpEqPY7oFVA9oYdxfl70WRcEhwjhNqmwl+X6utcCfKrrEQnObyXhpd1MXhrOTsm55cQ3eeBBJ/7Hye7iF5eV2uigv2Bfk239gMOdn6HK1ka55Y9+ar4E9T7E6tux4JsBSQlZNM/SAAFHbAZT/3eNsdDyJKiVUzB/AhDfg2zDx6XWeZReMMQ3Ja7IKJhGf3LoAWdItt/D5PFChm/K4DRX/02bYPxG46pOQNp9CINf0GymVMmlhCngqsBBwvehXIhJPQkNnbIJX3r6E8cGmTbw0EQ1SwXBwXsNttmQe8XoH7Ju2/I0bIPKUjnQxYQ== 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=FmQAproEMnTSl+z/XOK1WRkTu/KfZfgxgrxdPz3CBZk=; b=oDhV9sTjlK2niXKO9EHCdFBCBonxVOPf0fIJ6iRM/4HaUxatWXaoooIYr1w8pp7+boa3eXX8RCADukkzmA0h0U3YRhAlUTRsGI6xbziGBfzdgtpgAAWcM9/AR9ScKw92DW2Fh8b+bYbB+xaw71qZVn/fpeZ61FZPGpuYopgXYTH7G7lA6FV4Xxm62s9S2xt2PXkvUSMtvtR0+HXdYeIcHC9pZ4HC8X6fQIqiDMI25pondwDyRaN2D76jsSabPoeFF8024e2JTBYmqcZbR8BUomEVNFaB7T5jQE7xDw+NBT0SoO8pKMUARmMge5rW3SicO+wxgh4ooHidf9QROKOO7w== 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=FmQAproEMnTSl+z/XOK1WRkTu/KfZfgxgrxdPz3CBZk=; b=v5MdVD98DcvWw/eaN/avfWwavmDtB4igmmpgmsFn6pXHsuu5sed2Dg5lYbRzKAtLNuhLTPByokBE89MbPYF485clSCINd9s6oIwfkVCziPBsZzbCQWlD/asO7csdm8VowltPLb9UODZv5/8FlpzD9020w/rZLx+JjuZZ7pVm6oo= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DM4PR12MB6373.namprd12.prod.outlook.com (2603:10b6:8:a4::7) by CH3PR12MB9250.namprd12.prod.outlook.com (2603:10b6:610:1ae::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8964.21; Wed, 23 Jul 2025 19:46:44 +0000 Received: from DM4PR12MB6373.namprd12.prod.outlook.com ([fe80::12f7:eff:380b:589f]) by DM4PR12MB6373.namprd12.prod.outlook.com ([fe80::12f7:eff:380b:589f%5]) with mapi id 15.20.8964.019; Wed, 23 Jul 2025 19:46:44 +0000 Date: Wed, 23 Jul 2025 15:46:39 -0400 From: Yazen Ghannam To: Borislav Petkov Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Libing He , David Arcari , Mario Limonciello Subject: Re: [PATCH] x86/CPU/AMD: Ignore invalid reset reason value Message-ID: <20250723194639.GA1229722@yaz-khff2.amd.com> References: <20250721181155.3536023-1-yazen.ghannam@amd.com> <20250722165615.GCaH_CryG7kNrAS4O6@renoirsky.local> <20250723183426.GA1158000@yaz-khff2.amd.com> <27E487FE-EC8D-42AC-B259-F8A18776C802@alien8.de> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <27E487FE-EC8D-42AC-B259-F8A18776C802@alien8.de> X-ClientProxiedBy: LV3P220CA0026.NAMP220.PROD.OUTLOOK.COM (2603:10b6:408:234::27) To DM4PR12MB6373.namprd12.prod.outlook.com (2603:10b6:8:a4::7) 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: DM4PR12MB6373:EE_|CH3PR12MB9250:EE_ X-MS-Office365-Filtering-Correlation-Id: 400087c4-53c0-4adc-9fce-08ddca21a6f4 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?Al/sz+b3VpkZbSsIVBdLoUhEswq6XZaQ3Tf+NywpCM4EOu3x3fyzB+yEBAmE?= =?us-ascii?Q?M17iBeSNyWJABKecfTozXuMVbBNJW+6R8eVOzpOMnaXpvT9HHxRQzNVWti4B?= =?us-ascii?Q?ZoCBwf13BvJnGuCRJSZ9MRyMBhSpCxHAmgiPgIdemUHUvCfEq+XIZv00V2Iq?= =?us-ascii?Q?vIIz9QvgdVy1ph2nwRCjHd5fxbAfKl1kYaul97sgzKEDS6wmcuqUmoOlQZW+?= =?us-ascii?Q?QfWqeOmXDcjgszYKRTi9ScBjBZ/l+7QOQdquZZt06sHYcXzloXO0lK93JRyZ?= =?us-ascii?Q?Im3LEvjqo1YgN5d+26v04QZWygzvGzuPzP8aLGmssnjXB/QV03MFaP5MG9gn?= =?us-ascii?Q?1BsFlI1gQHYe1oZZro800GquOunO78fwTguwcOs6/j96YpRn0qpq5hWwKcEp?= =?us-ascii?Q?iicdjZwvCvLaXoyOjg/dmcsf1NfjTfOf//X80kkvtNFzUfl35vrNGvEKOCw3?= =?us-ascii?Q?2w85yPoc1kdvHu1Cp5JLP6dUL5XG+rDdQggGkC8qmnX5R6maVYzn+X9tpqy5?= =?us-ascii?Q?RYZ3TSKYb1Q0ZMKvoVHAMPHBZ4MXIDVNj1sFPfM97C8fybNbOWAG8n/AW7yb?= =?us-ascii?Q?8FafE0bZrQMCp3hw4aGu5YfDnKqQzBD+U/1qbPGcP9zC2gyO0uMkisMWemp+?= =?us-ascii?Q?VwllKrz3My6jsBb0G0BkozTh91s265/4tKGdRJ481k4P+QPfh9y12nYLb5gg?= =?us-ascii?Q?kGv/qVcnEJj1igPt5nx/feZHzE7IlL6CqmGLHeH4p3V1oAw+0JQAGCMoDvcY?= =?us-ascii?Q?bBtIZebkk5rrA78mvx5svnDCkt+TniX5WrfwA2YPCcY6AtvZ1GM/q9iqlbwj?= =?us-ascii?Q?w5rJltBlqm2tH4hinZxmZdipRmIkwBWOs63/isp5r3l3ZlxQygKy7VdqTYsk?= =?us-ascii?Q?+0qZnK0Enh4TgHL00jYuRYMsCLHA0GkRJVxJtcj3hJRUeIY6SqgfjxqHD0xx?= =?us-ascii?Q?A8pkbBxs9q5jvuOQkc8EKrNaVwurac/dFTHd0SULPGJcDhYbEMu0iht0bZIT?= =?us-ascii?Q?7b8IUmp1sbiA9184qHdApfjYb3jnROy4dYRyk29tNw+N6l+2XrUjLvSjaWz3?= =?us-ascii?Q?ePmF6xMGBJNz6YWC6yDuazhuGVvc2mOCDMiH/54/ACP2xQ2IFjnsCOnzcGpE?= =?us-ascii?Q?93zqlV0ET7FYIRAs/oxvnNU47Jz6JTksjFOT/C1EvS97d+boIFbyfeGZ3v1w?= =?us-ascii?Q?DzkP72Ea7B4rQa8bGftXxMykpTQgRzkpySkrv/UNR8WK1AFiZdk82VYCK/LR?= =?us-ascii?Q?Xqvg2CKAo4SCj8aoYIQ9t5iNZvL0pVDfdhraEZvCG2YYxEHmnoWB29Iati4M?= =?us-ascii?Q?RwA2yCIw1IMzP0HKB5JZ9RKmeBjAiAPhhZddS1i4Y+YqAAuS+Ce/AhBoks7w?= =?us-ascii?Q?9g293v0ZRuh/PfT2RVGX70V3cHABNPo0q9PqN0ot1YKsovSaxvqFlVn389/G?= =?us-ascii?Q?NUxV4LwF/us=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM4PR12MB6373.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?xGMH5OQ8tAlaHmpz53vdGF0SyrRF6HfxTJumfe09CAUJ00N2b5AulMIN/zic?= =?us-ascii?Q?xxzpJkGFVAl61PmdT280qWWKU76d8z36z2T3LWKviqEy2htsu0FcNyK0cYoL?= =?us-ascii?Q?MfINi2EA3y8lJBz7m+EiY2Qs1L50nfTiKn4rM3DF0hK5xEn8Ev4bTv+pPaV2?= =?us-ascii?Q?Yp1US8w3A+KioctSsk++KVH9/uRbWK/TiERcdXo/GWWajiv5/STnkWVouVb8?= =?us-ascii?Q?yAokVBKm050CZ0bORcNNAL1arxyXgPbLbNwALWp6l4gJOMm5kKJ1uQt0j8VE?= =?us-ascii?Q?4dg8qzCL+nNgmBFCb9NQEZChrVoTvZaRG1uy5+59Ly/IZUA9UUliy6o2jn4D?= =?us-ascii?Q?J29twT73oPQYW0hRlEhjBJ76QLvzos1J5krLI1Ep0vIj9s1byzWw5fH3Pkh7?= =?us-ascii?Q?71+++WwWQI4LvgDrq+yrfFLM024KXOZyF0Kw5SVtZIPsaeOUK6xMc+VhhyoL?= =?us-ascii?Q?4rJmVm125PpYu9z4BnM2hruPuztY/ddCN/7FNW94PMCxl3Nn2Kd6aZ+YQA19?= =?us-ascii?Q?QZlETzPS4VhtEJFI+dEKZ1X6BruCQw4uVaS9g92IAm3dLrr40qSb2uSf3Y95?= =?us-ascii?Q?bAgmF++3lFe+V9NwZ1Y9Bzy77RG55AwuevzMdYTA82msevp6LAXPBALoNDQN?= =?us-ascii?Q?orU55sjwNwzm7qEVbJBEBMkyCOlirIo7MO6lVRy5sh7q2l6yeHdCUVDoyI0O?= =?us-ascii?Q?Ub+TFsrZIyScq9QnbDfsqxDkiJdpYIJNZSEWF8G38ykXx4UPh78xy604rsZ9?= =?us-ascii?Q?NJOosRCrM65wNVlKtP6HKJGFLaZX+Zogyl9+zBAE5mfSmNBlvroC/hVkNWdK?= =?us-ascii?Q?ZEe4a6Wbj1Z4PdyJ9wl5ZTS/S0mCcZpdqrvl0U9fsoMHg25F7hxKMT8M63DG?= =?us-ascii?Q?T0CqrU6Kggn7YUY6ksYwXymWo+yqwefzazo6ION0U7V+bPGw984UvDIvotmQ?= =?us-ascii?Q?l/1Tn/6uN/olDlTyW9EawWW8qGmXDJypmOHySRi/AscAsrQkB6107n3+BwwF?= =?us-ascii?Q?pGfyVuoYtifHIOxJO99c4yMSGcAP+IjOH0VhYzWFtlvsVqetZu+vFhwPH3rK?= =?us-ascii?Q?VIlQyd9Cs88bmACSIuy4KriDzqsKUJX7fSsx3ODGy6TQ4saQIPi6laSbxV3H?= =?us-ascii?Q?Pkv99eMAYMPm3Jkz5rTIv/5Xby7BziTdXXZNMx131/XowHOhKw74JE6tc43T?= =?us-ascii?Q?DKl9B3DBOqFZidH9qR05iDVUyvRaoIEb50qGKwU+ruzQsfP/K7c3hcgk3feP?= =?us-ascii?Q?G4YUrXoTZmVUXUj6b4zPoSB6T0iREvsryHKkSVt7Vvz0eVXIvWgFKT0tg8XK?= =?us-ascii?Q?P3M0oH2yhWbTpIQ5RSyFWxMGcQJiX8DrOMuW3Ccep4Aegg57+D2Sd5YOnY4z?= =?us-ascii?Q?o1vQOWhgsamqq7sfIqYR5lOVHXsS4+/BABtcW7OXXHKMI6mJCRHEbaUtHFWb?= =?us-ascii?Q?oyFOdzbkxPj66/3GXzNB/FfNtqlqkjmolEFWn/Y1oLWDk21zGgbpFevZ0Fe6?= =?us-ascii?Q?ThRl9350RWdKVNB5xuyPeh5w2coC5mujmZy/Cx9+utCYb+kHopja414W5dhn?= =?us-ascii?Q?1t/pQNvzUE3zraRYhwOWswI7WLR1bNwOHVX6xm5e?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 400087c4-53c0-4adc-9fce-08ddca21a6f4 X-MS-Exchange-CrossTenant-AuthSource: DM4PR12MB6373.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Jul 2025 19:46:44.2841 (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: qmA/4ZNLyjPgAN7yb9X9Q4/tfBBCuwktZtbMli6QvQ0ZroZ0D73Wu4dU4uiu9tXheD3z/wSirt4o6UH2PLasiw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB9250 On Wed, Jul 23, 2025 at 10:35:31PM +0300, Borislav Petkov wrote: > On July 23, 2025 9:34:26 PM GMT+03:00, Yazen Ghannam wrote: > >On Tue, Jul 22, 2025 at 06:56:15PM +0200, Borislav Petkov wrote: > >> On Mon, Jul 21, 2025 at 06:11:54PM +0000, Yazen Ghannam wrote: > >> > The reset reason value may be "all bits set", e.g. 0xFFFFFFFF. This is a > >> > commonly used error response from hardware. This may occur due to a real > >> > hardware issue or when running in a VM. > >> > >> Well, which is it Libing is reporting? VM or a real hw issue? > >> > > > >In this case, it was a VM. > > > >> If it is a VM, is that -1 the only thing a VMM returns when reading that > >> MMIO address or can it be anything? > >> > >> If latter, you need to check X86_FEATURE_HYPERVISOR. > >> > >> Same for a real hw issue. > >> > >> IOW, is -1 the *only* invalid data we can read here or are we playing > >> whack-a-mole with it? > >> > > > >I see you're point, but I don't think we can know for sure all possible > >cases. There are some reserved bits that shouldn't be set. But these > >definitions could change in the future. > > > >And it'd be a pain to try and verify combinations of bits and configs. > >Like can bit A and B be set together, or can bit C be set while running > >in a VM, or can bit D ever be set on Model Z? > > > >The -1 (all bits set) is the only "applies to all cases" invalid data, > >since this is a common hardware error response. So we can at least check > >for this. > > > >Thanks, > >Yazen > > I think you should check both: HV or -1. > > HV covers the VM angle as they don't emulate this and we simply should disable this functionality when running as a guest. > > -1 covers the known-bad hw value. > Okay, will do. Thanks, Yazen