Re: [RFC PATCH v4 03/28] x86: Add the Secure Memory Encryption CPU feature

Borislav Petkov
2017-02-16T18:13:55Z

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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