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Date:   Thu, 14 Oct 2021 15:36:25 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Dov Murik <dovmurik@linux.ibm.com>
Cc:     linux-efi@vger.kernel.org, Borislav Petkov <bp@suse.de>,
        Ashish Kalra <ashish.kalra@amd.com>,
        Brijesh Singh <brijesh.singh@amd.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Andi Kleen <ak@linux.intel.com>,
        Andrew Scull <ascull@google.com>,
        Dave Hansen <dave.hansen@intel.com>,
        "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
        James Bottomley <jejb@linux.ibm.com>,
        Tobin Feldman-Fitzthum <tobin@linux.ibm.com>,
        Jim Cadden <jcadden@ibm.com>,
        Daniele Buono <dbuono@linux.vnet.ibm.com>,
        linux-coco@lists.linux.dev, linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/3] efi: Reserve confidential computing secret area
Message-ID: <YWgyWeoreYusT9/s@kroah.com>
References: <20211014130848.592611-1-dovmurik@linux.ibm.com>
 <20211014130848.592611-3-dovmurik@linux.ibm.com>
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In-Reply-To: <20211014130848.592611-3-dovmurik@linux.ibm.com>
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On Thu, Oct 14, 2021 at 01:08:47PM +0000, Dov Murik wrote:
> When efi-stub copies an EFI-provided confidential computing (coco)
> secret area, reserve that memory block for future use within the kernel.
> 
> Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
> ---
>  arch/x86/platform/efi/efi.c   |  1 +
>  drivers/firmware/efi/Makefile |  2 +-
>  drivers/firmware/efi/coco.c   | 41 +++++++++++++++++++++++++++++++++++
>  drivers/firmware/efi/efi.c    |  4 ++++
>  include/linux/efi.h           |  3 +++
>  5 files changed, 50 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/firmware/efi/coco.c
> 
> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 147c30a81f15..35e082e5f603 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -93,6 +93,7 @@ static const unsigned long * const efi_tables[] = {
>  #ifdef CONFIG_LOAD_UEFI_KEYS
>  	&efi.mokvar_table,
>  #endif
> +	&efi.coco_secret,

Shouldn't this depend on CONFIG_EFI_SECRET?

Why build all of this code if that option is not enabled?

thanks,

greg k-h