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Date:   Thu, 5 Sep 2019 12:51:18 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Borislav Petkov <bp@alien8.de>
cc:     "Raj, Ashok" <ashok.raj@intel.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Mihai Carabas <mihai.carabas@oracle.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        Jon Grimm <Jon.Grimm@amd.com>, kanth.ghatraju@oracle.com,
        konrad.wilk@oracle.com, patrick.colp@oracle.com,
        Tom Lendacky <thomas.lendacky@amd.com>,
        x86-ml <x86@kernel.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/microcode: Add an option to reload microcode even
 if revision is unchanged
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References: <1567056803-6640-1-git-send-email-ashok.raj@intel.com> <20190829060942.GA1312@zn.tnic> <20190829130213.GA23510@araj-mobl1.jf.intel.com> <20190903164630.GF11641@zn.tnic> <41cee473-321c-2758-032a-ccf0f01359dc@oracle.com> <D8A3D2BD-1FD4-4183-8663-3EF02A6099F3@alien8.de>
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On Thu, 5 Sep 2019, Borislav Petkov wrote:
> On Wed, Sep 04, 2019 at 05:21:32PM -0700, Raj, Ashok wrote:
> > 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.
> 
> Then before we continue with this, please specify what the exact
> requirements are. Talk to your microcoders or whoever is going to use
> this and give the exact use cases which should be supported and describe
> them in detail.

Plus I have to ask whether this facility makes any sense outside of
microcode development. If so, then please explain the use case and give
a proper justification why this needs to be in the mainline kernel.

Thanks,

	tglx