linux-kernel - Re: [PATCH 2/5] x86/microcode: Simplify init path even more

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Message-ID: <Y1BOkbXsQxCZK3U7@a4bf019067fa.jf.intel.com>
Date:   Wed, 19 Oct 2022 12:22:57 -0700
From:   Ashok Raj <ashok.raj@...el.com>
To:     Borislav Petkov <bp@...en8.de>
CC:     Tony Luck <tony.luck@...el.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Arjan van de Ven <arjan.van.de.ven@...el.com>,
        Jacob Jun Pan <jacob.jun.pan@...el.com>,
        X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>,
        Ashok Raj <ashok.raj@...el.com>
Subject: Re: [PATCH 2/5] x86/microcode: Simplify init path even more

On Wed, Oct 19, 2022 at 07:54:23PM +0200, Borislav Petkov wrote:
> From: Borislav Petkov <bp@...e.de>
> 
> Get rid of all the IPI-sending functions and their wrappers and use
> those which are supposed to be called on each CPU.

Good cleanup overall!.. Trying to apply them and do a quick test.

[snip]

> 
> +	/*
> +	 * Try to load microcode once on the BSP in case the initrd has older revision.
> +	 *  Frankly, I have no clue how that can happen but hey, loading here is cheap so
> +	 * why not.
> +	 */
> +	microcode_ops->request_microcode_fw(boot_cpu_data.cpu_index, &microcode_pdev->dev, true);
> +

You need to call a microcode_ops->apply_microcode() too if you want to
apply. But you also want to pay attention to the return code too and call
it appropriately.

>  	/* Do per-CPU setup */
>  	cpus_read_lock();
>  	on_each_cpu(setup_online_cpu, NULL, 0);
> -- 
> 2.35.1
>