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Fri, 8 Nov 2024 00:36:01 +0000 Message-ID: <5a42aca9-ff38-4fb5-8eb2-a43262c8c630@intel.com> Date: Thu, 7 Nov 2024 16:35:59 -0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/cpufeatures: Free up unused feature bits To: "H. Peter Anvin" , Dave Hansen , , Borislav Petkov , Dave Hansen CC: Thomas Gleixner , Ingo Molnar , "Sean Christopherson" , Tony Luck , References: <20241107233000.2742619-1-sohil.mehta@intel.com> <7ff32a10-1950-434b-8820-bb7c3b408544@intel.com> <3492e85d-4aaa-4dd7-9e6a-c8fdc2aa2178@intel.com> <74338393-4F39-4A04-83B1-BA64CE2D2FDA@zytor.com> Content-Language: en-US From: Sohil Mehta In-Reply-To: <74338393-4F39-4A04-83B1-BA64CE2D2FDA@zytor.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR03CA0126.namprd03.prod.outlook.com (2603:10b6:a03:33c::11) To BYAPR11MB3320.namprd11.prod.outlook.com (2603:10b6:a03:18::25) 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: BYAPR11MB3320:EE_|SJ0PR11MB4829:EE_ X-MS-Office365-Filtering-Correlation-Id: d01863d2-e61d-4e1d-2d34-08dcff8d51d5 X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|376014|1800799024; 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Peter Anvin wrote: >>> - if (c->x86 == 6) >>> - set_cpu_cap(c, X86_FEATURE_P3); >> > > Be careful - these bits are used in module strings and so modutils need to understand them. Sorry, I didn't understand this properly. How do I figure out whether these bits are used elsewhere? Can you please provide a pointer? Sohil