From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 E9A3E1FDD for ; Fri, 8 Nov 2024 00:38:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731026307; cv=none; b=D/675/Tmj9zqtIaTQQPuL0eg8oNXOsfsIMD8MT/rq27Xg0YJxMfoSHa0unycPrllzHWgpjiCpja5bapAvJVYVAMGdtNwJRE8fr4VRDgGI0vdzpz1j3wHw6aHwPj1HHSqeHrTJZKXq2nt0+QNmy2nSXAQe7DMgw3sEhO7brutDTQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731026307; c=relaxed/simple; bh=4n7khrBuMUtQBYvCABf9ZpMqgcGzS/P9GFvR2WXFNcU=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=CM7MekdpQ1SR+DB2rSiA6yiosEz8iozB4jvDnvYgTWpq5ck5HKfba7R3jnOvDW4jqJ6xd8Tb1Zyl1g9ox/TkGLbvFiICwgdNlgnlaDevAsDI7TM6xqCWS4snKE9294m8LLgT2Q30J6VvpXbij6DnPJqPvaDjqko3ObK2CdrQZCM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=FQnlI17G; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="FQnlI17G" Received: from [127.0.0.1] ([92.33.209.142]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 4A80bux11371923 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Thu, 7 Nov 2024 16:37:57 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 4A80bux11371923 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024101701; t=1731026279; bh=AIgENd9MH02dSondeIPZ91aDzNiaV51cCAN68ptAAPU=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=FQnlI17GxNduYpAt7tZ4xcCW3aRGzlga6LmSeNwjqa+qU+yp2FR8Eea1MXqbziCCj lLRzUPdbOIRnVrAyZ/rI5FbkQ/TiuWwcgOpMogbzpnKEpB8ZYVF+wH1kYTdmkSO4NR Dq9RxF/L7PLyoBuY/JWhpgrWKgy2/B8kkePINb4NPIwDuJnblmJJkuYqo/8U7AZ7EA ibDGEiPBUx10jUO8zOgAdGgByKSOxosp+QS35Ta4JF01NN2yYQjo5ASCixNJ1E3DSQ gP0+WZUQaOeTH7ejeae7Wbax7lMz6Khga6W5xdwJjyv/tdHWZF5fQupjKBusD/4oSv ACO/Jz7w1ambA== Date: Fri, 08 Nov 2024 01:37:50 +0100 From: "H. Peter Anvin" To: Sohil Mehta , Dave Hansen , x86@kernel.org, Borislav Petkov , Dave Hansen CC: Thomas Gleixner , Ingo Molnar , Sean Christopherson , Tony Luck , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/cpufeatures: Free up unused feature bits User-Agent: K-9 Mail for Android In-Reply-To: <5a42aca9-ff38-4fb5-8eb2-a43262c8c630@intel.com> 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> <5a42aca9-ff38-4fb5-8eb2-a43262c8c630@intel.com> Message-ID: <3732DC33-8959-494F-9A47-2ADD74C7E2DC@zytor.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On November 8, 2024 1:35:59 AM GMT+01:00, Sohil Mehta wrote: >On 11/7/2024 3:49 PM, H=2E Peter Anvin wrote: >>>> - if (c->x86 =3D=3D 6) >>>> - set_cpu_cap(c, X86_FEATURE_P3); >>> >>=20 >> Be careful - these bits are used in module strings and so modutils need= to understand them=2E > >Sorry, I didn't understand this properly=2E How do I figure out whether >these bits are used elsewhere? Can you please provide a pointer? > >Sohil Look at the modutils sources=2E