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 B948D2BD5A1 for ; Fri, 15 Aug 2025 03:56:35 +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=1755230200; cv=none; b=DU9wE3qiR1g4hp0XVJKWIjGaKVEmQHTICGPfChLYNQ+C6ZpZ82KAtMjanezlyiQlOYHNfznI5KiTMHvPcdbY4R3GhMwIb6EOUCMBZ+i+dHyQZm8KB67BhdYMpZcXx0q5CPvHItpUINKZhMdoPP83M4iXk986hhf8SPcs3HAvBZA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755230200; c=relaxed/simple; bh=LC+0r1AzLRQNFzzFqYcTyBVmRFtl65sXvmQZAJMc4nM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JethLtw9GCIo10p628dMqULt/YeUTI+AQw9Ha05KdY5/RaLDAseSLRFBaJ5RPJ7+aVurXn3dthXW7uHMMI+neFk55L6oYcUMT3ENevm57rWakZPBeJVH0Cob52O3Wp1KUs5wgvDIsDe/OG+2V+4D0MzWy59NJvFbhtYuJEZwdH8= 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=q0xI10ZH; 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="q0xI10ZH" 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 57F3tmTa1739033 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Thu, 14 Aug 2025 20:55:49 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 57F3tmTa1739033 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025072201; t=1755230149; bh=OJB7FdiAvmel+SE0lmiQf5qjZxdgRhyivcTW5IUkZ1E=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=q0xI10ZHX9qsaPo8XM/IFP54hx3h5O4RkR4h/l6f8fEsIuKtXI8FggwnOszozHpnU MDR6N+A8uRJW+S/2wQ1vtIdlW0onwlMxirILtd3TYEYRldSBHZth2o3BcWeNeinhCl buGNZl4xzF9Ti+3c6xnERt0DFgXSYMQsfTLLIGweE42toGj0eFsZBz/1I8EqVpc+jm tYuoGGjSkxgFRwzp6V7d/wndU187L2jnqlsVpgH0PaZfIC8GikTBUvwm3NLtICuvMx Oz/zvRluIDs95sfACp21QMXO6pFSnGX8tMPFCjbUe53KiGlDMD322heEe0DHi8oFdm 2hy0G6nJxv6zA== Message-ID: <02510395-25c1-4aa6-a836-85151927d2f7@zytor.com> Date: Thu, 14 Aug 2025 20:55:48 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/fred: Fix 64bit identifier in fred_ss To: Andrew Cooper , LKML Cc: "H. Peter Anvin" , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org References: <20250814190436.2555438-1-andrew.cooper3@citrix.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: <20250814190436.2555438-1-andrew.cooper3@citrix.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 8/14/2025 12:04 PM, Andrew Cooper wrote: > FRED can only be enabled in Long Mode. This is the 64bit mode (as opposed to > compatibility mode) identifier, rather than being something hard-wired at 1. > > Signed-off-by: Andrew Cooper > --- > CC: Xin Li > CC: "H. Peter Anvin" > CC: Andy Lutomirski > CC: Thomas Gleixner > CC: Ingo Molnar > CC: Borislav Petkov > CC: Dave Hansen > CC: x86@kernel.org > CC: linux-kernel@vger.kernel.org > > IIRC, this was wrong in an older version of the FRED spec. I made the same > mistake in Xen, and I didn't copy Linux's structure. > > I don't thinks this warrants backporting, but the fixes tag is: > > Fixes: 3c77bf02d0c0 ("x86/ptrace: Add FRED additional information to the pt_regs structure") > --- Oh right — to be precise, long mode (also known as IA-32e mode in the Intel SDM) includes two sub-modes: 1) Compatibility mode 2) 64-bit mode So, "long mode" is not the correct term in this context and should be corrected. Reviewed-by: Xin Li (Intel)