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Date:   Tue, 23 Jan 2018 21:16:15 +0100
From:   Pavel Machek <pavel@ucw.cz>
To:     David Woodhouse <dwmw2@infradead.org>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        KarimAllah Ahmed <karahmed@amazon.de>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andi Kleen <ak@linux.intel.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Andy Lutomirski <luto@kernel.org>,
        Arjan van de Ven <arjan@linux.intel.com>,
        Ashok Raj <ashok.raj@intel.com>,
        Asit Mallick <asit.k.mallick@intel.com>,
        Borislav Petkov <bp@suse.de>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "H . Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>,
        Joerg Roedel <joro@8bytes.org>,
        Jun Nakajima <jun.nakajima@intel.com>,
        Laura Abbott <labbott@redhat.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Tom Lendacky <thomas.lendacky@amd.com>, kvm@vger.kernel.org,
        x86@kernel.org, Arjan Van De Ven <arjan.van.de.ven@intel.com>
Subject: Re: [RFC 09/10] x86/enter: Create macros to restrict/unrestrict
 Indirect Branch Speculation
Message-ID: <20180123201615.GA6957@amd>
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On Sun 2018-01-21 20:28:17, David Woodhouse wrote:
> On Sun, 2018-01-21 at 11:34 -0800, Linus Torvalds wrote:
> > All of this is pure garbage.
> > 
> > Is Intel really planning on making this shit architectural? Has
> > anybody talked to them and told them they are f*cking insane?
> > 
> > Please, any Intel engineers here - talk to your managers. 
> 
> If the alternative was a two-decade product recall and giving everyone
> free CPUs, I'm not sure it was entirely insane.
> 
> Certainly it's a nasty hack, but hey — the world was on fire and in the
> end we didn't have to just turn the datacentres off and go back to goat
> farming, so it's not all bad.

Well, someone at Intel put world on fire. And then was selling faulty
CPUs for half a year while world was on fire; they knew they are
faulty yet they sold them anyway.

Then Intel talks about how great they are and how security is
important for them.... Intentionaly confusing between Meltdown and
Spectre so they can mask how badly they screwed. And without apologies.

> As a hack for existing CPUs, it's just about tolerable — as long as it
> can die entirely by the next generation.
> 
> So the part is I think is odd is the IBRS_ALL feature, where a future
> CPU will advertise "I am able to be not broken" and then you have to
> set the IBRS bit once at boot time to *ask* it not to be broken. That
> part is weird, because it ought to have been treated like the RDCL_NO
> bit — just "you don't have to worry any more, it got better".

And now Intel wants to cheat at benchmarks, to put companies that do
right thing at disadvantage and thinks that that's okay because world
was on fire?

At this point, I believe that yes, product recall would be
appropriate. If Intel is not willing to do it on their own, well,
perhaps courts can force them. Ouch and I wound not mind some jail time
for whoever is responsible for selling known-faulty CPUs to the public.

Oh, and still no word about the real fixes. World is not only Linux,
you see? https://pavelmachek.livejournal.com/140949.html?nojs=1

Best regards,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html