linux-kernel - Re: [PATCH 2/4] x86: Track minimum microcode revision globally v2

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Message-ID: <20120614091001.GA22155@liondog.tnic>
Date:	Thu, 14 Jun 2012 11:10:01 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	x86@...nel.org, linux-kernel@...r.kernel.org, eranian@...gle.com,
	peterz@...radead.org, Andi Kleen <ak@...ux.intel.com>
Subject: Re: [PATCH 2/4] x86: Track minimum microcode revision globally v2

On Wed, Jun 13, 2012 at 01:20:40PM -0700, Andi Kleen wrote:
> +/*
> + * Track the minimum global microcode version.  On early bootup assume
> + * the BIOS set all CPUs to the same revision. If that's not the case
> + * some code may be already running assuming the newer revision, but
> + * there's not much we can do about that (but it's unlikely to be
> + * problem in early bootup)
> + */
> +__cpuinit void boot_update_min_microcode(struct cpuinfo_x86 *c)
> +{	
> +	static int boot_min_microcode;
> +
> +	if (!boot_min_microcode) {
> +		boot_min_microcode = c->microcode;
> +		boot_cpu_data.microcode = c->microcode;
> +	} else if (c->microcode < boot_min_microcode) {
> +		pr_warn("CPU %d has lower microcode revision %x at boot than boot CPU (%x)\n",
> +			smp_processor_id(), 
> +			c->microcode,
> +			boot_min_microcode);

You still haven't told me what's the use of this printk statement to the
user. Should she update her microcode, buy a new box or go up in flames?

-- 
Regards/Gruss,
    Boris.
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