From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (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 7E45B2798EA for ; Tue, 24 Mar 2026 05:08:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=198.175.65.17 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774328930; cv=fail; b=HXEIIAzbKHLJrllAaiGLnp53EMQuc5G2q3JZkFZ+fmHBKfvkFBjA/eeE0XFRyKDgam2xDpsKNGQInztkZTctT7LF77sHJA2ELQZYomCo6O/07MMbemrhw9sgq4D7ce9ireyHDuxt1F9mGrgBlv7mQHOGPedsenfEJ2W3rjUDPdo= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774328930; c=relaxed/simple; bh=hXC/LYKsouwS9TdQ4CaI8XuMY509BCSEwAUIVeQ92ls=; h=Message-ID:Date:Subject:To:CC:References:From:In-Reply-To: Content-Type:MIME-Version; b=Q27sd58bJJySpCXtpHZs/C8xsLCrXyL7IxGxkrZVkRKY/WV7i5l+JIbiPY8xfxeajuKg52EonbpITAC87Q9iAOhU7J+5guuhYvhb5w7b/Q0RZOJ6T7OjphfaKihre7sUlG7+0AXuXkCVUq2O66QACD/Txb1wG37TOorubtK9aJw= 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=Fkh1aVYa; arc=fail smtp.client-ip=198.175.65.17 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="Fkh1aVYa" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1774328929; x=1805864929; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=hXC/LYKsouwS9TdQ4CaI8XuMY509BCSEwAUIVeQ92ls=; b=Fkh1aVYaSdSPMuu1xAnA/LF+NMKQ9y216ju84/3zrBIpq+sPP11yqlqm pF7MFiSVMeWySz8Wz7zaFEybmGyuZcWG1b1o7Z4P/xLNeEKzKNw2/3Dzb BYJwZFC3aIP1YrM27tqH83MnVmIc9nPRkjQPOa/IA+vNxnBtqtFN8aLT6 S2Spj6TXpUt3zQXO0po/m6GQDqDsDSNGeEWibguGlWvtrCenpG8oiyNSa gh+niWXZiURK18ISUDLsVTvMACj7mG8U1cg9HUEhkBQtXSgFhJBHr6kOW nP6147/4Q4luFl39cz6rTaDtBiI0YBXzo0mOa7+4sOqYpn2Hw5pCYVOp9 w==; X-CSE-ConnectionGUID: yBVxJf21STS2GxaQBjljTg== X-CSE-MsgGUID: 2oqeWS3hRDaHGPJ8wqJITA== X-IronPort-AV: E=McAfee;i="6800,10657,11738"; a="75309892" X-IronPort-AV: E=Sophos;i="6.23,138,1770624000"; d="scan'208";a="75309892" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2026 22:08:48 -0700 X-CSE-ConnectionGUID: ZzJF/VFOS0iN7RaS/jI4bA== X-CSE-MsgGUID: 3cwbEXNETnevdeebsd2lfw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,138,1770624000"; d="scan'208";a="262170278" Received: from orsmsx903.amr.corp.intel.com ([10.22.229.25]) by orviesa001.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2026 22:08:48 -0700 Received: from ORSMSX901.amr.corp.intel.com (10.22.229.23) by ORSMSX903.amr.corp.intel.com (10.22.229.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37; Mon, 23 Mar 2026 22:08:47 -0700 Received: from ORSEDG901.ED.cps.intel.com (10.7.248.11) by ORSMSX901.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37 via Frontend Transport; Mon, 23 Mar 2026 22:08:47 -0700 Received: from CY7PR03CU001.outbound.protection.outlook.com (40.93.198.51) by edgegateway.intel.com (134.134.137.111) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37; Mon, 23 Mar 2026 22:08:46 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=BPQL43iMDzX6Aw+Qx/GDNMhMjzwvJ2DspdALH2LnRF4E98PcKg3um/h2R5QCB4oVgWK3tzK/BYY69TA7kfiF0mENqlSNb4RFt0FAnRKoUMi3bRiWoYJe/lteixpk+iXAxjjoGU3QolcTK/p9yL8ll8s3MiWpDYnkbSx26l5lZi34vIshfn00YEpoQfJ3A56fYNBcbK7jyvkKFh0H40lLXNU8pl8TUwpDV/sZym/tfgtCNVHsusw/CvIufwDTxol1NcKfd5FqplM+B4brd1jKOd2WDojrFQHvJ8W7XeXXVawNJmWtPpdYV0o3kv+rgjf5dO4ZZa9j6tafDg2yJrmnXw== 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=czcYv9cNm1C4mRNimeZlFp4qNiuVwGY+zWDEkNeTuqI=; b=H8qMKqycwuVBO0lEL/Sb/vuKS1LqQuktqJPC5oXQhf1IA1ruSvl3kFXgU0Ko4/Usw5WnNIn3j3eRtemEebRjsbeZrceLvd0wvGgfaAD3RxhJ4hUs4G8jGXNavAy9TntrRJP46Pk15GiOR3qY+fXRzw0aISEXugQJeQ/jrjZmMrmSmAB7Y/eXldIdPw8HpP+AryBZ4BGnS9/TqwnXYCCNgm5tWztZ2StGBbnVkryxf6Osm9naAAFeVY2S+kd4pxHEBfvtZzx5HQwNGRPySUi45+v5hz5m6SJl65OwbzCH1+LMsrVrzGCCxVNsNCteX09v/7HDAkNWbsn0EzWQgfytRA== 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 DS0PR11MB7997.namprd11.prod.outlook.com (2603:10b6:8:125::14) by PH7PR11MB7550.namprd11.prod.outlook.com (2603:10b6:510:27d::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9745.20; Tue, 24 Mar 2026 05:08:44 +0000 Received: from DS0PR11MB7997.namprd11.prod.outlook.com ([fe80::24fa:827f:6c5b:6246]) by DS0PR11MB7997.namprd11.prod.outlook.com ([fe80::24fa:827f:6c5b:6246%4]) with mapi id 15.20.9745.019; Tue, 24 Mar 2026 05:08:44 +0000 Message-ID: <1fb5ae44-d443-414f-9d63-3efce4b73bc9@intel.com> Date: Mon, 23 Mar 2026 22:08:42 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] x86/fred: enable FRED by default Content-Language: en-US To: "H. Peter Anvin" , Xin Li CC: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , , "Peter Zijlstra (Intel)" , Kees Cook , "Ahmed S. Darwish" , References: <20260323201510.1537333-1-hpa@zytor.com> <84489fd4-aa23-4ba1-b5a1-c1baafb6718d@intel.com> <927AE575-3C10-427E-9C4B-0238CBF8301E@zytor.com> <763cbc92-fda0-454e-a2dd-919671db15c3@zytor.com> From: Sohil Mehta In-Reply-To: <763cbc92-fda0-454e-a2dd-919671db15c3@zytor.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BYAPR05CA0069.namprd05.prod.outlook.com (2603:10b6:a03:74::46) To DS0PR11MB7997.namprd11.prod.outlook.com (2603:10b6:8:125::14) 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: DS0PR11MB7997:EE_|PH7PR11MB7550:EE_ X-MS-Office365-Filtering-Correlation-Id: 27205a37-89d9-4e57-bef5-08de89636c10 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014|18002099003|22082099003|56012099003; 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:DS0PR11MB7997.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(7416014)(376014)(18002099003)(22082099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ZUZSNzNBYmpGUmhxNDFtdzc0OXFHZ1ArdHFMQzQxc1haZkh5U0RZNm9mVFVo?= =?utf-8?B?MlV0a1FDY3RVMkg5K1hrVkpjNGxRdHhWWU42WkVZblpib0lYcUMrUmJvY3Nw?= =?utf-8?B?bHNzdjZRakovemFsNkFGNm11UytJNFhmZnppcllzOGoycWFFazMvQ24zU2Vx?= =?utf-8?B?ZkpQOHRNaE5EQURqY1ZEVXh1NkFyRlBweUdjdE1aZzA4NHNQVTdDRjBwS002?= =?utf-8?B?TWVQRW5KbWY2emV6WEtOZUFKR1NVYXlQZHR5YjZtWnd0eC82dTdMdW15aXlW?= =?utf-8?B?Z0R3NHRQSmk0ZFNPam5tZWltSlBRbEFub1plckZnTGpCK3lldkFRd0RRazNk?= =?utf-8?B?YVY0cU9LNDhVOVdTTWNmeS9uKzhyd1VsSDdnTXVSN0pmU21tVE1wYTUrdHc1?= =?utf-8?B?c1R4N1ZsUFFud1lWaGFhbWw4dGtQUHlSUnVuK1ZsY3ZjeXVFU0JtZCtKeWdV?= =?utf-8?B?dzhDaDVxYzF4b1RicnJzV0dOR1ZnNGl5L1BnRi9ZUTVWQ3p5TnFOb2pMQnFT?= =?utf-8?B?R1BhRlhwTmZqTFBUcXBMNVE1VTZRRVlWWFloQTRzWTl2YnpBVWE3RW1JcXpU?= =?utf-8?B?YXlpM2dQMjF5YmY2STV0QVA2ckU1MWFnUXZCUGk3OXg0S0czcEplVlljcWZa?= =?utf-8?B?K1lpSkJCSHFEK05CcVRnd1ZrWWo2OEQvT3p1K0lhdEtqbTFtRWFlUlF6RVRD?= =?utf-8?B?b3VMREQ4d3d6cmpGcnZXZm5Kem91c3ZJRTdvZngyMHdhaVpOcDNzL04yUHFJ?= =?utf-8?B?Q0hJNTJLY1RQZTVWYnJXSGVQZUhoc3JleWF5aitTL3E1N21RSkRSY1pjZ0JB?= =?utf-8?B?V2JjTnBzS3RuM0F6dmVDZXB6dGFvbGorK2l1ZVF5QUZwS25FcU0wMzllODY1?= =?utf-8?B?dWpBc2hmcDlaZkVsczY4ZEpXZ09OVDFOM2w2Q3l3Tlg1djdCQ1VSaXZ1T2sy?= =?utf-8?B?MjZnRldwU0hBWTB2YnpZMXBrMUtBNmxqc1daNURsaG5JZ2pzSitlRnp6MC9n?= =?utf-8?B?V3dHTlJQckwyL3hTRmx3bDgxeEJYRXN1Y3dnUVFJWjd0ZXlhbzJxbXZ5NzF5?= =?utf-8?B?U1NCbGc4U2NJc3VaaHhQSnNxUzNBcjUvaUg1eDg1bzlzMjhpV3FlY1NlbDhG?= =?utf-8?B?OUhvTmYyTWpJMlFlWVExbTI0NllnejlJKzAvNkZsTzUvUEhNdFQ2UEY5ZlpD?= =?utf-8?B?S2NwbnoyTkhiODZ1STZLWVBFVU1UL1BwS0F2OVR1ZUVOeU5YTlU5QUpuYXJF?= =?utf-8?B?U2g3UXA2Ry9yNHgzODdKVzhTdGxKNFhXdTBJQXhKdURWTFJ6YUlKSFZsVGhL?= =?utf-8?B?NXZ6eGo2bzJiU0d3dzhPQ1E0S3dDZmdHTCtHSHZVUG55Y1RPeSswOXVuRnFk?= =?utf-8?B?SE5WR2V0S0RMYlBjUFJLNHRUTlJFb29KUmhodXY1ZUF0TEt4NTNnWEhpa3Qy?= =?utf-8?B?aUZiZEc5d1dIWFpaaE5Za2huOHFuZTQvZ1lic1ZZbm1INGlkRzRpRnlGK0dl?= =?utf-8?B?bjZkVUdoMURCQUFWRDd4Vll5aGR0NlYzY0dldWJ6d0FCc2g3akYrM2NwZzk4?= =?utf-8?B?WFZHbjhLTTRPdFgrYmplVXI3M1Z1SFAva1o5UVF6eG1acVlMVCtJMWNLa0kz?= =?utf-8?B?RysxUHJmVVJaazhZK2VLMHNGRjlpNkV5bEJpcUJUKzErZEErZGFmQ1Z3WHBT?= =?utf-8?B?STJEMERZZHFmQVpKNENnSkRYSjdnYmtSQ0JqMEZFNjEvc2gxOUdzUHN5QjFM?= =?utf-8?B?elloZlFJUTdnajBnSnAvaDQ5d3ljNmFjQXVWWmVWTXAxcmVYZldUa0VwTnU5?= =?utf-8?B?NUc4NDY1dWJDYXFvQW0ySVE5ZzYvMWkrYUROYXhXY2c5MStQWjdYcU80VEtw?= =?utf-8?B?Z2FBYnJlbnJFaVBkTktCL2h0NkxyR2IzdldMZnM4ek1ibG1UaGhKSVFsWWNE?= =?utf-8?B?NW1pMkNhS1gxd1Z0VExIcURReDBCYi9YZkVtR1NvcXZld3lJNmJZcERXaml0?= =?utf-8?B?eUJTOHBYVmNralJxOW1YZjhsWUE4M0x4Tk9WenZzNGJQMFZmT3dCcGw5VUh1?= =?utf-8?B?QytUUENEN1ZwamUvMTMrQVJraHg4bCtuTVpmeHBTanNBZWZoa0Y3QllVNGVW?= =?utf-8?B?NnFJM3pJY3pTN0VTczB2Y0h4YXcwVldGSUl3NldQZEk2Rk1sSE5yekJaeFpm?= =?utf-8?B?cWx0MDkwd0Rxb21LSE52UUN5eGFyTU9LUW9CbHRSbFdNQXNjK1ZHMkpUWms3?= =?utf-8?B?VVIzaU9JUzBlbWxXRkR1QVZSRTd4a3Q1aSt2WHFBTFBIVFB2WXNZYkpaaVly?= =?utf-8?B?ems2eHBuaVRrTkJzSXFBV3ZzRGE4RmwzcXUrejBKQzZzc0o1RGpTZz09?= X-Exchange-RoutingPolicyChecked: Obc8DTvEpiXLXQUlVR7gqQSXhAbABBwwnIxvuLWx7ck3xMq1FrZGq7ZjAhttDW6z+f/XKR8o2kXWgE96i731f441UbGZbnAihHsNewAyEH3Iv6ms1eZ7FGyHmxH3/EJ3OTt4L91SuT24jWHzo53gN1DZb1dgIsul+ujEmAajqGMrYCFhFaiIYCLY8F4B25CPevccKS7BsXz5UoOVfQy+mEk9uxdZL8a0EWGAi81DaNOS1ttHUSOO5spO2VJhYh7gUCXBLLqR29GKbVWalf+CfYlbmoZ7PhqF+6DrMd1nDvjLL3dOUX3yZIMRYpCtUOJ6jBqzs1FObLK3W/CXAOx+WA== X-MS-Exchange-CrossTenant-Network-Message-Id: 27205a37-89d9-4e57-bef5-08de89636c10 X-MS-Exchange-CrossTenant-AuthSource: DS0PR11MB7997.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Mar 2026 05:08:44.2812 (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: nUjPvBqxRctRbLYmwbMIU623RWJFehaz3T22TcHL6fIwZzqEl4rv7qMMjoXrU5Lpt8MhdPA9Ix/jPPVTpUTjeg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR11MB7550 X-OriginatorOrg: intel.com On 3/23/2026 8:52 PM, H. Peter Anvin wrote: >>> Nit: Would it be better to compare with "off" rather than not on? >> >> +1 :) >> > > It would change the meaning of something like "fred=0" though. > I don't believe we have ever supported fred=0 or fred=1, did we? Also, I am not sure about letting userspace be creative with command line parameters :) For example, fred=yes and fred=enable will both pass the same check and cause FRED to be disabled.