From mboxrd@z Thu Jan  1 00:00:00 1970
From: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>
Subject: Re: [RFC PATCH v4 03/28] x86: Add the Secure Memory Encryption CPU
	feature
Date: Thu, 16 Feb 2017 19:13:55 +0100
Message-ID: <20170216181355.bjxo2h6vlhukz4ih@pd.tnic>
References: <20170216154158.19244.66630.stgit@tlendack-t1.amdoffice.net>
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To: Tom Lendacky <thomas.lendacky-5C7GfCeVMHo@public.gmane.org>
Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Brijesh Singh <brijesh.singh-5C7GfCeVMHo@public.gmane.org>, Toshimitsu Kani <toshi.kani-ZPxbGqLxI0U@public.gmane.org>, Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Alexander Potapenko <glider-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, "H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>, Larry Woodman <lwoodman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Andrey Ryabinin <aryabinin-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org>, Rik van Riel <riel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>, Andy Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>, Dmitry Vyukov <dvyukov-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, "Michael S. Tsirkin" <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Paolo Bonzini <pbonzini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
List-Id: linux-mm.kvack.org

On Thu, Feb 16, 2017 at 09:42:36AM -0600, Tom Lendacky wrote:
> Update the CPU features to include identifying and reporting on the
> Secure Memory Encryption (SME) feature.  SME is identified by CPUID
> 0x8000001f, but requires BIOS support to enable it (set bit 23 of
> SYS_CFG MSR).  Only show the SME feature as available if reported by
> CPUID and enabled by BIOS.
> 
> Signed-off-by: Tom Lendacky <thomas.lendacky-5C7GfCeVMHo@public.gmane.org>
> ---
>  arch/x86/include/asm/cpufeature.h        |    7 +++++--
>  arch/x86/include/asm/cpufeatures.h       |    5 ++++-
>  arch/x86/include/asm/disabled-features.h |    3 ++-
>  arch/x86/include/asm/msr-index.h         |    2 ++
>  arch/x86/include/asm/required-features.h |    3 ++-
>  arch/x86/kernel/cpu/common.c             |   19 +++++++++++++++++++
>  6 files changed, 34 insertions(+), 5 deletions(-)

What happened here?

You had it already:

https://lkml.kernel.org/r/20161110003459.3280.25796.stgit-qCXWGYdRb2BnqfbPTmsdiZQ+2ll4COg0XqFh9Ls21Oc@public.gmane.org

The bit in get_cpu_cap() with checking the MSR you can add at the end of
init_amd() for example.

-- 
Regards/Gruss,
    Boris.

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