From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E772C7115C for ; Fri, 20 Jun 2025 23:47:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EB0F26B007B; Fri, 20 Jun 2025 19:47:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E5E4D6B0088; Fri, 20 Jun 2025 19:47:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D266F6B0089; Fri, 20 Jun 2025 19:47:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id A423F6B007B for ; Fri, 20 Jun 2025 19:47:17 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 26FAC1A1491 for ; Fri, 20 Jun 2025 23:47:17 +0000 (UTC) X-FDA: 83577417714.05.54C1715 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) by imf09.hostedemail.com (Postfix) with ESMTP id B6ABE140004 for ; Fri, 20 Jun 2025 23:47:14 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=zytor.com header.s=2025052101 header.b=S3NWUDY5; dmarc=pass (policy=none) header.from=zytor.com; spf=pass (imf09.hostedemail.com: domain of xin@zytor.com designates 198.137.202.136 as permitted sender) smtp.mailfrom=xin@zytor.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1750463235; a=rsa-sha256; cv=none; b=LNMvjQQr9Lt4v16cF/qqXWllWbe/OqOlRVIa6hDLgBBem10MKbcjCedxgYtXcJryvz5hxq oOImmRZaoIsOw2NXZbpBSW06OSyhCsWlSLxSvisKGpsN2mE60SDl8zKw2RgV/0R/f3zEtg Qlx/jDKTDlGILM3e8uRGpZjqrQBCxTk= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=zytor.com header.s=2025052101 header.b=S3NWUDY5; dmarc=pass (policy=none) header.from=zytor.com; spf=pass (imf09.hostedemail.com: domain of xin@zytor.com designates 198.137.202.136 as permitted sender) smtp.mailfrom=xin@zytor.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1750463235; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=40gKYnXltXyrwG1wEPpVQm7rYUrKhq5AMYqi5C6BXhc=; b=m0kNFDR6+UuVvo35R+hAvIqcPzNJOu9OYcMDxDdY7/ecQInzXB61Xw3+3kFqF+9SODmjkm rQU3k4XVP+ahBHqoP3Ad0flpeYOjRNXR9yI7qyaKMwTXxEJpvyvUgUCcvb0WXa0WeSQeVJ 0Dcozf5tmRVKvBSw4luvBLbpvlVtZTQ= Received: from [192.168.7.202] ([71.202.166.45]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 55KNkMRm2688788 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Fri, 20 Jun 2025 16:46:23 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 55KNkMRm2688788 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025052101; t=1750463190; bh=40gKYnXltXyrwG1wEPpVQm7rYUrKhq5AMYqi5C6BXhc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=S3NWUDY5Fuh1GZtV4hRZIIADubXtAr1Tfd5R6g7Zr6H9nHlLuUNbaCuSGm/QBecI5 UbShea4fpDCqp2g6aMgDiT/Xcl+2R0S5Hpg5UdvvTnfHdOBXRXQSKgeo5PZ50SFQYB iQ7ChGWDiBW1q8/xKznNtJ0XhBJX6N3wzYZ70BG8v7NWLdRljzs7ilqQMihPO3TYqA aqhoLBKNDKT4/fcMFctM26xPcK9osLdgNADOOrO4KIxN9SaWQgCS34NfpOYozVAgDn HpILOwHflqk7wpirq+gjg8C65LYTN/+5pbl/xnk9RQ9PnnEsb8YGcABR2QPyLpNmwt Q9Rk+ke8vRlew== Message-ID: Date: Fri, 20 Jun 2025 16:46:21 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHv6 01/16] x86/cpu: Enumerate the LASS feature bits To: "Kirill A. Shutemov" Cc: Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Ard Biesheuvel , "Paul E. McKenney" , Josh Poimboeuf , Xiongwei Song , Xin Li , "Mike Rapoport (IBM)" , Brijesh Singh , Michael Roth , Tony Luck , Alexey Kardashevskiy , Alexander Shishkin , Jonathan Corbet , Sohil Mehta , Ingo Molnar , Pawan Gupta , Daniel Sneddon , Kai Huang , Sandipan Das , Breno Leitao , Rick Edgecombe , Alexei Starovoitov , Hou Tao , Juergen Gross , Vegard Nossum , Kees Cook , Eric Biggers , Jason Gunthorpe , "Masami Hiramatsu (Google)" , Andrew Morton , Luis Chamberlain , Yuntao Wang , Rasmus Villemoes , Christophe Leroy , Tejun Heo , Changbin Du , Huang Shijie , Geert Uytterhoeven , Namhyung Kim , Arnaldo Carvalho de Melo , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-mm@kvack.org, Yian Chen References: <20250620135325.3300848-1-kirill.shutemov@linux.intel.com> <20250620135325.3300848-2-kirill.shutemov@linux.intel.com> Content-Language: en-US From: Xin Li Autocrypt: addr=xin@zytor.com; keydata= xsDNBGUPz1cBDACS/9yOJGojBFPxFt0OfTWuMl0uSgpwk37uRrFPTTLw4BaxhlFL0bjs6q+0 2OfG34R+a0ZCuj5c9vggUMoOLdDyA7yPVAJU0OX6lqpg6z/kyQg3t4jvajG6aCgwSDx5Kzg5 Rj3AXl8k2wb0jdqRB4RvaOPFiHNGgXCs5Pkux/qr0laeFIpzMKMootGa4kfURgPhRzUaM1vy bsMsL8vpJtGUmitrSqe5dVNBH00whLtPFM7IbzKURPUOkRRiusFAsw0a1ztCgoFczq6VfAVu raTye0L/VXwZd+aGi401V2tLsAHxxckRi9p3mc0jExPc60joK+aZPy6amwSCy5kAJ/AboYtY VmKIGKx1yx8POy6m+1lZ8C0q9b8eJ8kWPAR78PgT37FQWKYS1uAroG2wLdK7FiIEpPhCD+zH wlslo2ETbdKjrLIPNehQCOWrT32k8vFNEMLP5G/mmjfNj5sEf3IOKgMTMVl9AFjsINLHcxEQ 6T8nGbX/n3msP6A36FDfdSEAEQEAAc0WWGluIExpIDx4aW5Aenl0b3IuY29tPsLBDQQTAQgA NxYhBIUq/WFSDTiOvUIqv2u9DlcdrjdRBQJlD89XBQkFo5qAAhsDBAsJCAcFFQgJCgsFFgID AQAACgkQa70OVx2uN1HUpgv/cM2fsFCQodLArMTX5nt9yqAWgA5t1srri6EgS8W3F+3Kitge tYTBKu6j5BXuXaX3vyfCm+zajDJN77JHuYnpcKKr13VcZi1Swv6Jx1u0II8DOmoDYLb1Q2ZW v83W55fOWJ2g72x/UjVJBQ0sVjAngazU3ckc0TeNQlkcpSVGa/qBIHLfZraWtdrNAQT4A1fa sWGuJrChBFhtKbYXbUCu9AoYmmbQnsx2EWoJy3h7OjtfFapJbPZql+no5AJ3Mk9eE5oWyLH+ QWqtOeJM7kKvn/dBudokFSNhDUw06e7EoVPSJyUIMbYtUO7g2+Atu44G/EPP0yV0J4lRO6EA wYRXff7+I1jIWEHpj5EFVYO6SmBg7zF2illHEW31JAPtdDLDHYcZDfS41caEKOQIPsdzQkaQ oW2hchcjcMPAfyhhRzUpVHLPxLCetP8vrVhTvnaZUo0xaVYb3+wjP+D5j/3+hwblu2agPsaE vgVbZ8Fx3TUxUPCAdr/p73DGg57oHjgezsDNBGUPz1gBDAD4Mg7hMFRQqlzotcNSxatlAQNL MadLfUTFz8wUUa21LPLrHBkUwm8RujehJrzcVbPYwPXIO0uyL/F///CogMNx7Iwo6by43KOy g89wVFhyy237EY76j1lVfLzcMYmjBoTH95fJC/lVb5Whxil6KjSN/R/y3jfG1dPXfwAuZ/4N cMoOslWkfZKJeEut5aZTRepKKF54T5r49H9F7OFLyxrC/uI9UDttWqMxcWyCkHh0v1Di8176 jjYRNTrGEfYfGxSp+3jYL3PoNceIMkqM9haXjjGl0W1B4BidK1LVYBNov0rTEzyr0a1riUrp Qk+6z/LHxCM9lFFXnqH7KWeToTOPQebD2B/Ah5CZlft41i8L6LOF/LCuDBuYlu/fI2nuCc8d m4wwtkou1Y/kIwbEsE/6RQwRXUZhzO6llfoN96Fczr/RwvPIK5SVMixqWq4QGFAyK0m/1ap4 bhIRrdCLVQcgU4glo17vqfEaRcTW5SgX+pGs4KIPPBE5J/ABD6pBnUUAEQEAAcLA/AQYAQgA JhYhBIUq/WFSDTiOvUIqv2u9DlcdrjdRBQJlD89ZBQkFo5qAAhsMAAoJEGu9DlcdrjdR4C0L /RcjolEjoZW8VsyxWtXazQPnaRvzZ4vhmGOsCPr2BPtMlSwDzTlri8BBG1/3t/DNK4JLuwEj OAIE3fkkm+UG4Kjud6aNeraDI52DRVCSx6xff3bjmJsJJMb12mWglN6LjdF6K+PE+OTJUh2F dOhslN5C2kgl0dvUuevwMgQF3IljLmi/6APKYJHjkJpu1E6luZec/lRbetHuNFtbh3xgFIJx 2RpgVDP4xB3f8r0I+y6ua+p7fgOjDLyoFjubRGed0Be45JJQEn7A3CSb6Xu7NYobnxfkwAGZ Q81a2XtvNS7Aj6NWVoOQB5KbM4yosO5+Me1V1SkX2jlnn26JPEvbV3KRFcwV5RnDxm4OQTSk PYbAkjBbm+tuJ/Sm+5Yp5T/BnKz21FoCS8uvTiziHj2H7Cuekn6F8EYhegONm+RVg3vikOpn gao85i4HwQTK9/D1wgJIQkdwWXVMZ6q/OALaBp82vQ2U9sjTyFXgDjglgh00VRAHP7u1Rcu4 l75w1xInsg== In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: B6ABE140004 X-Stat-Signature: 1g565ychcsegt6n7es69hqp8pzcxtjiy X-Rspam-User: X-HE-Tag: 1750463234-4351 X-HE-Meta: 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 DCYlTCvS ydY75kiS7GGGGUAhD8YufZzjDfvaqJXS+YB9NTllzgyq9CHMNK3x6avBUrMX4zZdEC8bpeZc+dtKK/DXo7l+ELlPFkh8Vqc+3zs3xld9mFmJObhMs8Wh7g9kkG7z3CZVxAUf4DtWtrPsp05yvWH2w+v6+MlTWGjHG/z6zzBBIqr4N1Xd/pAuysVk+Ur8rkP0GkmHAhFxG0BAaf1TNjzFGofTTyxDMfNw4ItfWPZ/+u6oM5PbTv4i9qCkfk0zxidXGLl9nk1y5B3ZaRqH3fcT4+A+ZcDEcQCc5JJFFaaIu8WwWGrtwbdXQg+Mu9GhY0ZJ1aXZY1tNj10fZAAyTTQYd0kWt36IqlOy7csQWZInNWWXlXIk= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 6/20/2025 10:31 AM, Kirill A. Shutemov wrote: > On Fri, Jun 20, 2025 at 08:36:30AM -0700, Xin Li wrote: >> On 6/20/2025 6:53 AM, Kirill A. Shutemov wrote: >>> diff --git a/arch/x86/Kconfig.cpufeatures b/arch/x86/Kconfig.cpufeatures >>> index 250c10627ab3..9574c198fc08 100644 >>> --- a/arch/x86/Kconfig.cpufeatures >>> +++ b/arch/x86/Kconfig.cpufeatures >>> @@ -124,6 +124,10 @@ config X86_DISABLED_FEATURE_PCID >>> def_bool y >>> depends on !X86_64 >>> +config X86_DISABLED_FEATURE_LASS >>> + def_bool y >>> + depends on !X86_64 >>> + >>> config X86_DISABLED_FEATURE_PKU >>> def_bool y >>> depends on !X86_INTEL_MEMORY_PROTECTION_KEYS >> >> You don't need to add X86_DISABLED_FEATURE_LASS, because the LASS code >> is NOT optional at build time, i.e., you now don't have CONFIG_X86_LASS. > > Hmm. But it is optional. It depends on CONFIG_X86_64. I don't think we > want it to be advertised on 32-bit kernels. > I kind of ignore 32-bit... But I simply hate adding a disabled feature that depends on !X86_64; x86_64 has a broad scope, and new CPU features are often intentionally not enabled for 32-bit. (X86_DISABLED_FEATURE_PCID is the only one before LASS)