Re: [tip:x86/urgent] x86/kconfig: Add a Kconfig shortcut for building working KVM guest kernels

From: Borislav Petkov <bp@alien8.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>,
	David Rientjes <rientjes@google.com>,
	hpa@zytor.com, linux-kernel@vger.kernel.org, penberg@kernel.org,
	levinsasha928@gmail.com, mtosatti@redhat.com, tglx@linutronix.de,
	bp@suse.de, fengguang.wu@intel.com,
	linux-tip-commits@vger.kernel.org, Michal Marek <mmarek@suse.cz>
Subject: Re: [tip:x86/urgent] x86/kconfig:  Add a Kconfig shortcut for building working KVM guest kernels
Date: Fri, 3 May 2013 16:29:00 +0200	[thread overview]
Message-ID: <20130503142900.GA3433@pd.tnic> (raw)
In-Reply-To: <20130502200703.GE16684@pd.tnic>

On Thu, May 02, 2013 at 10:07:03PM +0200, Borislav Petkov wrote:a
> I wonder if one can exclude options from randconfig until 'select' has
> been taught to resolve dependencies...

So I talked to Michal on IRC about the whole deal and the fact of the
matter is, unless someone steps up and rewrites the Kconfig solver so
that selects work as expected, this option would break whenever one
of those selected option's dependencies change or said option is made
configurable.

Which means, the next best thing would be to have a small file
somewhere, maybe in scripts/kconfig/ or so, called 'allrand.config' and
which has default settings for randconfig builds. It would have

# CONFIG_KVM_GUEST_COMMON_OPTIONS is not set

so that this option is always disabled in randconfigs.

Frankly, I much rather prefer this than going nuts and including every
possible dependency just so some obscure randconfigs don't break (that's
not the point of this option anyway); and then having to run around and
fix it once some of the selected option's dependencies change.

Opinions?

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--