linux-kernel - Re: [PATCH] x86: Prefer MWAIT over HALT on AMD processors

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: <Yk1cnYWF+L+OgoCa@zn.tnic>
Date:   Wed, 6 Apr 2022 11:25:49 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Wyes Karny <wyes.karny@....com>
Cc:     linux-kernel@...r.kernel.org, Lewis.Carroll@....com,
        Mario.Limonciello@....com, gautham.shenoy@....com,
        Ananth.Narayan@....com, bharata@....com, len.brown@...el.com,
        x86@...nel.org, tglx@...utronix.de, mingo@...hat.com,
        dave.hansen@...ux.intel.com, hpa@...or.com, peterz@...radead.org,
        chang.seok.bae@...el.com, keescook@...omium.org, metze@...ba.org,
        zhengqi.arch@...edance.com, mark.rutland@....com
Subject: Re: [PATCH] x86: Prefer MWAIT over HALT on AMD processors

On Wed, Apr 06, 2022 at 11:44:52AM +0530, Wyes Karny wrote:
> If x86_FEATURE_ZEN is set and X86_FEATURE_MWAIT is not set or has
> X86_BUG_MONITOR then it won't return correct value.

Can that ever happen on Zen uarch?

Also, what does this mean: "allow MWAIT early on."?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette