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

From: Raj, Ashok
Date: Wed Sep 04 2019 - 20:21:34 EST


On Thu, Sep 05, 2019 at 12:12:29AM +0200, Boris Petkov wrote:
> On September 5, 2019 12:06:54 AM GMT+02:00, Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> wrote:
> >Why do we need to taint kernel here? We are not making any changes.
>
> Because this is not a normal operation we want users to do. This is only for testing microcode quicker.
>
> >This won't allow people to load from new microcode blob which I thought
> >was one of the objectives behind this new feature.
>
> You load a new blob the usual way: echo 1 > ...
>
> This is the "unusual" way where you reload an already loaded revision only.

But echo 2 > reload would allow reading a microcode file from
/lib/firmware/intel-ucode/ even if the revision hasn't changed right?

#echo 1 > reload wouldn't load if the revision on disk is same as what's loaded,
and we want to permit that with the echo 2 option.