Re: [PATCH] x86/microcode: Add an option to reload microcode even if revision is unchanged

[Boris Ostrovsky]

On 9/3/19 12:46 PM, Borislav Petkov wrote:
>
>  
> @@ -629,8 +639,12 @@ static ssize_t reload_store(struct device *dev,
>  	if (ret)
>  		return ret;
>  
> -	if (val != 1)
> +	if (val == 2) {
> +		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);

Why do we need to taint kernel here? We are not making any changes.


> +		return microcode_reload_late(apply_microcode_nocheck);
> +	} else if (val != 1) {
>  		return size;
> +	}
>  
>  	tmp_ret = microcode_ops->request_microcode_fw(bsp, &microcode_pdev->dev, true);

This won't allow people to load from new microcode blob which I thought
was one of the objectives behind this new feature.

-boris