Subject: Re: [PATCH] efi: add efi_runtime state checking
From: Matt Fleming <matt@console-pimps.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Olof Johansson <olof@lixom.net>, Marko Kohtala <marko.kohtala@gmail.com>,
        linux-kernel@vger.kernel.org, mjg@redhat.com
In-Reply-To: <502AF27D.2010902@zytor.com>
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Date: Sat, 18 Aug 2012 14:39:18 +0100
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On Tue, 2012-08-14 at 17:51 -0700, H. Peter Anvin wrote:
> On 06/28/2012 10:02 AM, Olof Johansson wrote:
> > On Wed, Jun 27, 2012 at 2:52 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> >> On 06/27/2012 02:35 PM, Olof Johansson wrote:
> >>>
> >>> This adds an efi_runtime variable indicating whether the
> >>> efi runtime services are available. The only time they are
> >>> expected to not be available is when a 32-bit kernel has been
> >>> booted using 64-but EFI and vice versa.
> >>>
> >>> It also adds checking to the two locations where functions are
> >>> called; x86 reboot and efivars.
> >>>
> >>
> >> OK, stupid question:
> >>
> >> Why is this different from the efi_enabled variable, or rather: why is it
> >> different from what the efi_enabled variable *should* be?  If runtime
> >> services aren't available the only "EFI" that is available to the kernel are
> >> the data structures passed in, and those can be checked directly...
> >
> > Excellent question, and I think it would work to turn off efi_enabled
> > towards the end of setup_arch() for non-native boots. That'd solve all
> > these problems, I believe.
> >
> > I'll try it out and revise this patch. It might take me a day or two
> > to get cycles for it.
> >
> 
> Ping?

There's now a bugzilla report for tracking this,

	https://bugzilla.kernel.org/show_bug.cgi?id=45991


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