Date: Fri, 5 Jan 2018 14:51:40 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: Andrea Arcangeli <aarcange@redhat.com>
cc: Tim Chen <tim.c.chen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Arjan Van De Ven <arjan.van.de.ven@intel.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/7] x86/feature: Detect the x86 feature to control
 Speculation
In-Reply-To: <20180105134400.GC26807@redhat.com>
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References: <cover.1515086770.git.tim.c.chen@linux.intel.com> <427aa76dea14532dea7e49f0bce4e7cf1dea7c6f.1515086770.git.tim.c.chen@linux.intel.com> <alpine.DEB.2.20.1801051405500.1724@nanos> <20180105134400.GC26807@redhat.com>
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On Fri, 5 Jan 2018, Andrea Arcangeli wrote:
> On Fri, Jan 05, 2018 at 02:09:43PM +0100, Thomas Gleixner wrote:
> Now about the late microcode my preference is not for static_cpu_has
> and forcing the early microcode, but my long term preference is to
> start with this/boot_cpu_has() and then turn static_cpu_has in a true
> static key so that setup_force_cpu_cap shall also flip the static key
> for all static_cpu_has(X86_FEATURE_IBPB_SUPPORT) also if run any time
> after boot and not only if run before the static_cpu_has alternative
> is patched in.

Fair enough. We can avoid the static_cpu_has() to begin with and fix it
later.

Thanks,

	tglx