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Date:   Fri, 5 Apr 2019 17:26:50 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Josh Poimboeuf <jpoimboe@redhat.com>
Cc:     linux-kernel@vger.kernel.org, x86@kernel.org,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>,
        "H . Peter Anvin" <hpa@zytor.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Jiri Kosina <jikos@kernel.org>,
        Waiman Long <longman@redhat.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Jon Masters <jcm@redhat.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        linuxppc-dev@lists.ozlabs.org,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        linux-s390@vger.kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Tyler Hicks <tyhicks@canonical.com>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH RFC 2/5] x86/speculation: Add support for
 'cpu_spec_mitigations=' cmdline options
Message-ID: <20190405152650.GH23348@zn.tnic>
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On Fri, Apr 05, 2019 at 09:31:01AM -0500, Josh Poimboeuf wrote:
> My thinking was that the individual options could be used to override
> the global option.  But maybe that's overkill?  I dunno.

You mean if the user deliberately types:

"cpu_spec_mitigations=off spectre_v2=auto"

on the cmdline to turn off all and then enable only one?

Hmm, yap, sounds like an overkill to me. Then I'd probably do:

	pr_err("Make up your mind already!\n");
	return;

:-))

I'd say let's do the simpler and cleaner thing now and think about
supporting this overkill when it really turns out that it is needed.

> I assume you mean just the part where L1TF_MITIGATION_DEFAULT is added?

Yap.

Thx.

-- 
Regards/Gruss,
    Boris.

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