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From:   Matthew Garrett <mjg59@google.com>
Date:   Tue, 2 Apr 2019 14:51:14 -0700
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Subject: Re: [PATCH 0/4] Enabling secure boot on PowerNV systems
To:     Claudio Carvalho <cclaudio@linux.ibm.com>
Cc:     linuxppc-dev@ozlabs.org, linux-efi <linux-efi@vger.kernel.org>,
        linux-integrity <linux-integrity@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Paul Mackerras <paulus@samba.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Jeremy Kerr <jk@ozlabs.org>,
        Matthew Garret <matthew.garret@nebula.com>,
        Nayna Jain <nayna@linux.ibm.com>
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On Tue, Apr 2, 2019 at 2:11 PM Claudio Carvalho <cclaudio@linux.ibm.com> wrote:
> We want to use the efivarfs for compatibility with existing userspace
> tools. We will track and match any EFI changes that affect us.

So you implement the full PK/KEK/db/dbx/dbt infrastructure, and
updates are signed in the same way?

> Our use case is restricted to secure boot - this is not going to be a
> general purpose EFI variable implementation.

In that case we might be better off with a generic interface for this
purpose that we can expose on all platforms that implement a secure
boot key hierarchy. Having an efivarfs that doesn't allow the creation
of arbitrary attributes may break other existing userland
expectations.