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Date: Mon, 22 Jan 2018 10:51:53 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Borislav Petkov <bp@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	KarimAllah Ahmed <karahmed@amazon.de>, 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>,
	Dan Williams <dan.j.williams@intel.com>,
	Dave Hansen <dave.hansen@intel.com>,
	David Woodhouse <dwmw@amazon.co.uk>,
	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>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
	Tim Chen <tim.c.chen@linux.intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>, kvm@vger.kernel.org,
	x86@kernel.org
Subject: Re: [RFC 05/10] x86/speculation: Add basic IBRS support
 infrastructure
Message-ID: <20180122095153.GB2228@hirez.programming.kicks-ass.net>
References: <1516476182-5153-1-git-send-email-karahmed@amazon.de>
 <1516476182-5153-6-git-send-email-karahmed@amazon.de>
 <alpine.DEB.2.20.1801211524160.1998@nanos>
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On Sun, Jan 21, 2018 at 03:56:55PM +0100, Borislav Petkov wrote:
> Also, blacklisting microcode for early loading will become an ugly dance
> so I'd like to avoid it if possible.
> 
> Thus, it would be much much easier if dracut/initrd creation thing
> already filters those blacklisted blobs by looking at the revision in
> the header. Which is much easier.

That wouldn't be enough; AFAIU there's people with this stuff already
flashed in their BIOS. So the kernel needs to deal with it one way or
another.