linux-kernel - Re: [PATCH v6 01/15] x86/mce: Set CR4.MCE last during init

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <96b2a8c2-3619-4f9c-8760-aa396e63e472@suse.com>
Date: Wed, 10 Sep 2025 14:43:00 +0300
From: Nikolay Borisov <nik.borisov@...e.com>
To: Yazen Ghannam <yazen.ghannam@....com>, x86@...nel.org,
 Tony Luck <tony.luck@...el.com>, "Rafael J. Wysocki" <rafael@...nel.org>
Cc: linux-kernel@...r.kernel.org, linux-edac@...r.kernel.org,
 Smita.KoralahalliChannabasappa@....com, Qiuxu Zhuo <qiuxu.zhuo@...el.com>,
 linux-acpi@...r.kernel.org
Subject: Re: [PATCH v6 01/15] x86/mce: Set CR4.MCE last during init

On 9/8/25 18:40, Yazen Ghannam wrote:
> Set the CR4.MCE bit as the last step during init. This brings the MCA
> init flow closer to what is described in the x86 docs.
> 
> x86 docs:
> 	AMD		Intel
> 			MCG_CTL
> 	MCA_CONFIG	MCG_EXT_CTL
> 	MCi_CTL		MCi_CTL
> 	MCG_CTL
> 	CR4.MCE		CR4.MCE
> 
> Current Linux:
> 	AMD		Intel
> 	CR4.MCE		CR4.MCE
> 	MCG_CTL		MCG_CTL
> 	MCA_CONFIG	MCG_EXT_CTL
> 	MCi_CTL		MCi_CTL
> 
> Updated Linux:
> 	AMD		Intel
> 	MCG_CTL		MCG_CTL
> 	MCA_CONFIG	MCG_EXT_CTL
> 	MCi_CTL		MCi_CTL
> 	CR4.MCE		CR4.MCE
> 
> The new init flow will match Intel's docs, but there will still be a
> mismatch for AMD regarding MCG_CTL. However, there is no known issue
> with this ordering, so leave it for now.
> 
> Signed-off-by: Yazen Ghannam <yazen.ghannam@....com> 

Reviewed-by: Nikolay Borisov <nik.borisov@...e.com>