From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from PH7PR06CU001.outbound.protection.outlook.com (mail-westus3azon11010010.outbound.protection.outlook.com [52.101.201.10]) (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 EF6A63C1987 for ; Thu, 14 May 2026 20:24:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.201.10 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778790301; cv=fail; b=YyvtfBQfQzfDB9vOq4mDYcYC7RQ4CBFAMBRq3eM51zk7Y+hng0SBpFi58COP8Su3/XlSu+sZL1zGYc+tEGRRBbfntXrrXT2UIXlVVi2scFru6EtcUqLoZgtBsJgbJDioYVIlSvYY/plNbgvr/BElqCM+JEiIERC1ffZJEQuoSig= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778790301; c=relaxed/simple; bh=3q+GgNOgB1OEhT74RNDAwcUJfMNu38Io0f63Bbn1hyQ=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=ZsQQDfEDCdcbGFSuu/2DqNKs5WZ71x7rTeS7j3LGaaj8Mz+ElpOT0etQOkEofDxJcl8loPyB9s5C8HTbMS43jw6+W3XYqTaSIR9J3WQf65AT1eSVJP4CsdsUxeyJmOP38/DroSYHpFKAS5lHm6ySQaMjXygUde2kJSVEePgfy90= 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=c4zJFFd3; arc=fail smtp.client-ip=52.101.201.10 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="c4zJFFd3" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=TIZfqkvDaT3rOBGLpMvLI5gTQvj6CK4NcTe10NaqY5zuWdbSMyaG4lZ1X5hyu8Swn1mm/efmqQupyX60RLePTkAbrgSyN82AkbL2AsKBukq57vAvNMeR6BhyToqFJybHLL+yXDZS7mODKbhop6ZkfMB4Wljl2IRSwusu5Y39COvhbLBiBUfurUbuZXYE5Ceto79E4WhVmq0mcSrL74HC1hZPYkAx6dUKSmaSjjWdUbBvolbmuipZkP2I5t84BVpfixcerP/yttwBofpAHK0TgMxS+WoLkJS0d2JXhuoejupCpg/0PuEdUiYh7bc8k9KRMRiqslLovP9uXwEwEc6AZw== 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=OGHvVR9jkkjtA8tmKp15x2pfJpsq5JjJnBmsCPfBOMw=; b=dsyhygLWFtLhRnAYL1DkcIWvutTTCCZbWgmxX+FRQezQpE1ddF1B3AA4o6GQEgDg+oYJ2PL4CIlGoHsv56UcJLbnHROfP6V9panNoZEfsUg0PLZVlMXPO3LmRxl7hQr+OU+H3jMFIqxRSTa8002Uz6Tyf/mmh41iY0ckY+n+xQmB3HiNuuSU0xcwNe74FgjcxmSD5F9jdRO8M5r1Nb2qymkpb79a44ycHrEaeXJi/4z28z4mi5/+ZcX0VFa5uAZL+b2AZpRwk6lTk/NLNQdUe/gr8URp+dQQZpMBtBfqoRaERPF82K1WpSe7IUD5g6o2n+yKO7xouJdxslybDQhwbw== 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=OGHvVR9jkkjtA8tmKp15x2pfJpsq5JjJnBmsCPfBOMw=; b=c4zJFFd3MWtTjf+sjPD1sYqH11d650B5FgMlS4cILwAZTJWdPWLPCkctQAcmZ5VYsnvuxkHmqxbDzQprpL6HhVP9S9CcCm9wzZ8ANcy2r/4KNGNxEUKaVCLLZRZbGXhsgcPkSdYQB7PswUf5qmYz7UmdB8Pe56H3nL9+dAdD0yw= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DM4PR12MB5070.namprd12.prod.outlook.com (2603:10b6:5:389::22) by SJ2PR12MB8832.namprd12.prod.outlook.com (2603:10b6:a03:4d0::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9913.12; Thu, 14 May 2026 20:24:55 +0000 Received: from DM4PR12MB5070.namprd12.prod.outlook.com ([fe80::f3f2:852c:78d5:9353]) by DM4PR12MB5070.namprd12.prod.outlook.com ([fe80::f3f2:852c:78d5:9353%4]) with mapi id 15.20.9870.023; Thu, 14 May 2026 20:24:54 +0000 Message-ID: <0276dd43-43c1-4646-b803-f24faf4fcccd@amd.com> Date: Thu, 14 May 2026 15:24:52 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/mm: Skip global ASID broadcast TLB flush when PCID is disabled To: Dave Hansen , linux-kernel@vger.kernel.org, x86@kernel.org Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Nadav Amit , Rik van Riel References: <6d67675458bfe4ac1ed792beec3ad93dd45848c7.1778695885.git.thomas.lendacky@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: 7bit X-ClientProxiedBy: CH2PR02CA0015.namprd02.prod.outlook.com (2603:10b6:610:4e::25) To DM4PR12MB5070.namprd12.prod.outlook.com (2603:10b6:5:389::22) 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: DM4PR12MB5070:EE_|SJ2PR12MB8832:EE_ X-MS-Office365-Filtering-Correlation-Id: e518c35b-20c3-4517-1869-08deb1f6dc0f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016|11063799003|4143699003|18002099003|22082099003|56012099003|3023799003; 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:DM4PR12MB5070.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016)(11063799003)(4143699003)(18002099003)(22082099003)(56012099003)(3023799003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?TGc5OG5WcSt0eW5oMUZyb1lLdXE5am4zNkdrSG90ZjU1LzVGQlpXU2JZc3ZV?= =?utf-8?B?UVRVM0FaSFp0U25OR21sUjJwd1Q1Z0U5MGRZTVBWb21uQk5PUHMxaG1qNmo1?= =?utf-8?B?RStsZVo3WGdrRWJHRXdZN3ZkYzdWUmdIYVRxTG9za1pjTS9oZTYwREZsd3lU?= =?utf-8?B?NmxXYzJnMGUxbGpZRE9RZWJtYWdxN1NaUWVqYXZQaFVZVy9Xc1hhR1M2dUo0?= =?utf-8?B?aHQxcjNXd1BwcGdkMW9qZTNQb1A2TzRVRnRqdVBMTThINUdHM2RoOHNJRDlC?= =?utf-8?B?cVZvemNVZ3pMaEhOZVMvUzh4TTc0TTZlUi9tbFF0cm1PWlBieUEyOUhza0x2?= =?utf-8?B?ZWJRb0xycFB3VmlPaVJWVGRHNjFPbUw2Si9yVWRVeWNHK2ZESXZjQ2IvTkEz?= =?utf-8?B?UVZPMEF1RzFEMzFoL2p0QmRwSnNZSDFvbUloSUhiVDVmRWE1UnFpZ2N6VCt2?= =?utf-8?B?bWVyVnZ3Q0kxOWYrdUZuN1IvUXBYcThjRVJoTksxaE5NYjNQQThhMHBZWXNo?= =?utf-8?B?ZDBXYTlVMy95bDhXNUFOd0NpTDd2ZjUrUURVYkowRmlnWHhoRGNYaWhXd0w2?= =?utf-8?B?YUE2UmxieDhHb3BSSUFvWWNkSEE5ODhRWVA3eGpXN0tpS3NqbXd3bzdSN0dk?= =?utf-8?B?RWlmMWdqdUVZcUZhaDlHejRESFB1d1c0d3FlYWZneVlHV3NnVXk4a2RtSmxD?= =?utf-8?B?OXI2ZUUvREZtSVhpaW4xVVZRdzNIajVJQnlDcHNZREhEdHRkSkh4c01FdFNF?= =?utf-8?B?cWZCUXkrUXJvcExUWnh3UkRrekRkMHVFamJIMlV4Mk5mRzVrcmN5TGNjZFZn?= =?utf-8?B?VE04QlRJMUFNcng3ZEhoQU9oNmh5OFdQT3ZKTDlYcVV4aVZtSDhTT0tqQkMv?= =?utf-8?B?QUo5QjhPejlyU3ZIRWJNVG9YaFJDWW5UU21XT2NMQmpEc3cvRGd6RjhRS3BH?= =?utf-8?B?bjZwUWFmK2c3TnpGNDk3Z3NwN1RzbW82VHgxM2k4QTVQVys3bTdqbXZxTllZ?= =?utf-8?B?RlhjcVJSQSsyOUo5MkRuN05XOFp0N09iSkZiaXFiRVBnQ0swV0d5MEhVS2RO?= =?utf-8?B?Uk5ZMGhnSUxKb2ljNU5vWmJINHRkWXA4aVZoRnBid3ZUMndxK2VyVitwc1dv?= =?utf-8?B?VkJyWXFZdlNFbmswYjZmK1d4YjlNa1l2eHFwUkVScEFPZHJSV05TT1R1WDBr?= =?utf-8?B?MDFMeVo3OXByajVhUVFBYU9DTVAxcmd0WDhjN0dtMHRHSzNKd1czR2tHRndD?= =?utf-8?B?elJQcUhnQVBFZmM2WFpqMGpzRWhPc28ya2w5U05IcHdoMFJXYXF2SWVZSFlB?= =?utf-8?B?ZlcwR3BsYkMxMWE0UWU3alJaWlpQZ2MvblZDcjV5RTlFdkQzdlZhdWZ1ZGk3?= =?utf-8?B?ME0vRkFBWlYyNkFsYURORHNEM3RuaHJwV0lWSm1aUlpQM3F5T3JGeU5kVFY5?= =?utf-8?B?UTU1ZEwzMkxSbWtlMi8xaFo3NXdTRjVMZGlRMEdhWnJnUlRENzZOdWJjYnI1?= =?utf-8?B?TWlBUm9laC9GT3QydmpsQ1Y3WTBMb0ZmZnk1NUlWdXZaYklBeGVaS0ltcUFl?= =?utf-8?B?dHRtQ3lMZDRwRUFqZStYazQ0ajRtQWx3bjBUMCthWjVaRG90UlJRZ2dyeERt?= =?utf-8?B?VUZUTERsRVNrdWJCZWNFVUhISHZacDNYTU5ZbE9ZK2xMUUxsVmFyaENDeEtH?= =?utf-8?B?UDhySHozb2ZnSkZVSTFOcHI0N3V6ajYvdmlRNXFDTWdZeGhQQkljVXdzQ0VT?= =?utf-8?B?TlJjK3BYZEdLMzFKTmM3dGZ0cjIySHRPazBSWEsvVmFxbzlzQmUzN0FBYW1u?= =?utf-8?B?UkRITG1TQmhQaFFLSVZsZnZwMGNoMitIZE13ZEdHaFhFTGg2cVM0Q3BPWnVG?= =?utf-8?B?T0F5Qm84d09PY1ErZjY5VThidUxZTE5GNkhpTHY0K2pMT0xzSGh5WTkwelQv?= =?utf-8?B?VHhTcVh2UTlGSzZZcTB5QitjVVlwcUwzWlZabDQ0MVVtb1BMSzlRR2pMNENQ?= =?utf-8?B?bW8xVU1ubUxtVGtUTlh3bTdiWXlWeUZEMGlRc1Z2WkZMczgyOC9INDVKd2VR?= =?utf-8?B?S0F2ZlF3TjFJVTN1T0lib29uVHNmSkRlQ2l5TERxSUhZMVcvQ2xaV2ZoN2Ja?= =?utf-8?B?TkJVQmZEaFRqdWMrRi8zM2J2OUVjN01VSkxxOUxtcVpuNjhvVEJZYW5RMllD?= =?utf-8?B?SlYvRElqRy84NmJkUHlYSHRsbmtoQitFUzB3RUtiNHpnZ1ExM2ltTFBya2ZR?= =?utf-8?B?b0NPam9OM3VuaXg0YkN4WUlpMk04VUdVdTF4VktMS2xFSnhXc0wvZ3lUaVdZ?= =?utf-8?Q?FfR4vGs8VFmKvVGXcG?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: e518c35b-20c3-4517-1869-08deb1f6dc0f X-MS-Exchange-CrossTenant-AuthSource: DM4PR12MB5070.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 May 2026 20:24:54.8859 (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: We8NHqKRthH4wizak8G+YmzhDFzDRZLPPfULwxhhOPmLZoHtUoQs+qZ8Hl0C9tnm5NOMRgcHt9oB7ta+6rJAjQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR12MB8832 On 5/13/26 13:29, Dave Hansen wrote: > On 5/13/26 11:11, Tom Lendacky wrote: >> Booting with "nopcid" clears X86_FEATURE_PCID in x86_nopcid_setup(), >> but X86_FEATURE_INVLPGB is left intact. On AMD CPUs that support >> INVLPGB, broadcast TLB flushing remains active even though CR4.PCIDE >> is off. >> >> There are two checks that decide whether the global ASID code runs, >> mm_global_asid() and consider_global_asid(), that key off of the >> X86_FEATURE_INVLPGB feature. Once an mm becomes active on more than >> three CPUs, consider_global_asid() assigns it a global ASID, after which >> flush_tlb_mm_range() takes the broadcast_tlb_flush() path. The >> broadcast_tlb_flush() function calls invlpgb_flush_single_pcid_nosync() or >> invlpgb_flush_user_nr_nosync() with kern_pcid(asid), which expands to >> (asid + 1). Both helpers set INVLPGB_FLAG_PCID and place the non-zero >> PCID into EDX[31:16] of the INVLPGB instruction. Issuing INVLPGB with >> INVLPGB_FLAG_PCID (RAX[1]) and a non-zero PCID (RDX[27:16]) while >> CR4.PCIDE is not set results in a #GP: > > Just to be clear, the APM says there's a #GP if: "CR4.PCID =0 and > EDX[PCID] is not zero." I don't think INVLPGB_FLAG_PCID (RAX[1]) is > supposed to play a role. > > Although the architecture doesn't care, it's also at least a _little_ > funky to be setting INVLPGB_FLAG_PCID here: > > u8 flags = INVLPGB_FLAG_PCID | INVLPGB_FLAG_VA; > > when PCIDs are disabled. > > How about we add a: > > static const struct cpuid_dep cpuid_deps[] = { > ... > { X86_FEATURE_INVLPGB, X86_FEATURE_PCID }, > > and be done with it? > > If you don't have PCIDs, you don't get INVLPGB at all. Yes, you could > theoretically use INVLPGB for kernel mappings without PCIDs. But all > actual CPUs that have INVLPGB presumably also have PCID support. > > Then we never have to worry about cases where INVLPGB==1, but PCID==0 at > *all*. That's ok with me. Tested and confirmed working. I can submit a v2 if everyone is ok with this approach. I'll give it a couple of more days... Thanks, Tom