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Tue, 7 Apr 2026 19:52:10 +0000 Message-ID: <9580a35f-afa4-41a6-b53c-1f16033cea7f@intel.com> Date: Tue, 7 Apr 2026 12:52:07 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 1/3] x86/process: Shorten the default LAM tag width Content-Language: en-US To: Maciej Wieczor-Retman CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , References: From: Sohil Mehta In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR05CA0198.namprd05.prod.outlook.com (2603:10b6:a03:330::23) To DS0PR11MB7997.namprd11.prod.outlook.com (2603:10b6:8:125::14) Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR11MB7997:EE_|BL3PR11MB6531:EE_ X-MS-Office365-Filtering-Correlation-Id: 29564d17-cb57-4cd4-a75c-08de94df281d 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|1800799024|7416014|376014|22082099003|18002099003|56012099003; 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But that isn't true anymore, right? How about naming this as LAM_TAG_BITS to match ARCH_GET_MAX_TAG_BITS? > static void enable_lam_func(void *__mm) > { > @@ -814,7 +814,7 @@ static void enable_lam_func(void *__mm) > static void mm_enable_lam(struct mm_struct *mm) > { > mm->context.lam_cr3_mask = X86_CR3_LAM_U57; > - mm->context.untag_mask = ~GENMASK(62, 57); > + mm->context.untag_mask = ~GENMASK(57 + LAM_DEFAULT_BITS - 1, 57); > Also, would it be useful to calculate the LAM mask as a #define because it might need to be reused later or copied over to the selftest (as in patch 3)?