linux-kernel - Re: [PATCH 4/5] efi: Export Runtime Configuration Interface table to sysfs

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Message-ID: <CAKv+Gu9iLxkJgmxZR+1yvCTj6GiCDuyfN_QiGXEWBHS7uYUbfQ@mail.gmail.com>
Date:   Tue, 1 Oct 2019 11:41:35 +0200
From:   Ard Biesheuvel <ard.biesheuvel@...aro.org>
To:     Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     Narendra K <Narendra.K@...l.com>,
        linux-efi <linux-efi@...r.kernel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        James Morse <james.morse@....com>,
        Mario Limonciello <mario.limonciello@...l.com>,
        Xiaofei Tan <tanxiaofei@...wei.com>
Subject: Re: [PATCH 4/5] efi: Export Runtime Configuration Interface table to sysfs

On Tue, 1 Oct 2019 at 11:03, Geert Uytterhoeven <geert@...ux-m68k.org> wrote:
>
> Hi Ard,
>
> On Tue, Oct 1, 2019 at 10:54 AM Ard Biesheuvel
> <ard.biesheuvel@...aro.org> wrote:
> > On Tue, 1 Oct 2019 at 10:51, Geert Uytterhoeven <geert@...ux-m68k.org> wrote:
> > > On Mon, Aug 12, 2019 at 5:07 PM Ard Biesheuvel
> > > <ard.biesheuvel@...aro.org> wrote:
> > > > From: Narendra K <Narendra.K@...l.com>
> > > >
> > > > System firmware advertises the address of the 'Runtime
> > > > Configuration Interface table version 2 (RCI2)' via
> > > > an EFI Configuration Table entry. This code retrieves the RCI2
> > > > table from the address and exports it to sysfs as a binary
> > > > attribute 'rci2' under /sys/firmware/efi/tables directory.
> > > > The approach adopted is similar to the attribute 'DMI' under
> > > > /sys/firmware/dmi/tables.
> > > >
> > > > RCI2 table contains BIOS HII in XML format and is used to populate
> > > > BIOS setup page in Dell EMC OpenManage Server Administrator tool.
> > > > The BIOS setup page contains BIOS tokens which can be configured.
> > > >
> > > > Signed-off-by: Narendra K <Narendra.K@...l.com>
> > > > Reviewed-by: Mario Limonciello <mario.limonciello@...l.com>
> > > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
> > >
> > > Thanks, this is now commit 1c5fecb61255aa12 ("efi: Export Runtime
> > > Configuration Interface table to sysfs").
> > >
> > > > --- a/drivers/firmware/efi/Kconfig
> > > > +++ b/drivers/firmware/efi/Kconfig
> > > > @@ -180,6 +180,19 @@ config RESET_ATTACK_MITIGATION
> > > >           have been evicted, since otherwise it will trigger even on clean
> > > >           reboots.
> > > >
> > > > +config EFI_RCI2_TABLE
> > > > +       bool "EFI Runtime Configuration Interface Table Version 2 Support"
> > > > +       help
> > > > +         Displays the content of the Runtime Configuration Interface
> > > > +         Table version 2 on Dell EMC PowerEdge systems as a binary
> > > > +         attribute 'rci2' under /sys/firmware/efi/tables directory.
> > > > +
> > > > +         RCI2 table contains BIOS HII in XML format and is used to populate
> > > > +         BIOS setup page in Dell EMC OpenManage Server Administrator tool.
> > > > +         The BIOS setup page contains BIOS tokens which can be configured.
> > > > +
> > > > +         Say Y here for Dell EMC PowerEdge systems.
> > >
> > > A quick Google search tells me these are Intel Xeon.
> > > Are arm/arm64/ia64 variants available, too?
> > > If not, this should be protected by "depends on x86" ("|| COMPILE_TEST"?).
> >
> > The code in question is entirely architecture agnostic, and defaults
> > to 'n', so I am not convinced this is needed. (It came up in the
> > review as well)
>
> "make oldconfig" still asks me the question on e.g. arm64, where it is
> irrelevant, until arm64 variants of the hardware show up.
>
> So IMHO it should have "depends on X86 || COMPILE_TEST".
>

Fair enough. I am going to send out a bunch of EFI fixes this week, so
I'll accept a patch that makes the change above.