Re: [Part1 PATCH v5 02/17] x86/mm: Add Secure Encrypted Virtualization (SEV) support

[Borislav Petkov <bp@suse.de>]

On Wed, Sep 27, 2017 at 10:13:14AM -0500, Brijesh Singh wrote:
> From: Tom Lendacky <thomas.lendacky@amd.com>
> 
> Provide support for Secure Encrypted Virtualization (SEV). This initial
> support defines a flag that is used by the kernel to determine if it is
> running with SEV active.
> 
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: linux-kernel@vger.kernel.org
> Cc: x86@kernel.org
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
>  arch/x86/include/asm/mem_encrypt.h |  6 ++++++
>  arch/x86/mm/mem_encrypt.c          | 26 ++++++++++++++++++++++++++
>  include/linux/mem_encrypt.h        |  7 +++++--
>  3 files changed, 37 insertions(+), 2 deletions(-)

Reviewed-by: Borislav Petkov <bp@suse.de>

> +bool sev_active(void)
> +{
> +	return sme_me_mask && sev_enabled;

What I'm still missing is the chicken bit. I.e., to be able to boot with
"mem_encrypt=smeonly" or so, which disables the SEV side but can still
allow SME. For when SEV has issues and people want to disable it.

You can do the patch ontop of those and send it as a reply to this
thread - no need to wait to resend the whole thing again.

Thanks.

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
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