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From:   Len Brown <lenb@kernel.org>
Date:   Tue, 24 Aug 2021 18:51:40 -0400
Message-ID: <CAJvTdKnPMjY5iKaz+ch14Syc_=n2+xiTrBEK020XwkHGJQQWJw@mail.gmail.com>
Subject: Re: [PATCH v9 12/26] x86/fpu/xstate: Use feature disable (XFD) to
 protect dynamic user state
To:     Borislav Petkov <bp@alien8.de>
Cc:     Thiago Macieira <thiago.macieira@intel.com>,
        "Chang S. Bae" <chang.seok.bae@intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>, X86 ML <x86@kernel.org>,
        "Brown, Len" <len.brown@intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        "Liu, Jing2" <jing2.liu@intel.com>,
        "Ravi V. Shankar" <ravi.v.shankar@intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Wed, Aug 18, 2021 at 2:09 PM Borislav Petkov <bp@alien8.de> wrote:

> What relevance does the fact have for userspace whether the kernel
> supports XFD or not?

Right.
If user space needs to know that XFD exists, then we have done
something very wrong.

-- 
Len Brown, Intel Open Source Technology Center