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Date:   Wed, 31 Jan 2018 12:30:36 +0000
From:   "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To:     Borislav Petkov <bp@suse.de>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Christophe de Dinechin <christophe.de.dinechin@gmail.com>,
        Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        David Woodhouse <dwmw2@infradead.org>,
        Arjan van de Ven <arjan@linux.intel.com>,
        Eduardo Habkost <ehabkost@redhat.com>,
        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>,
        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>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "H . Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
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        the arch/x86 maintainers <x86@kernel.org>
Subject: Re: [RFC,05/10] x86/speculation: Add basic IBRS support
 infrastructure
Message-ID: <20180131123036.GD2521@work-vm>
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* Borislav Petkov (bp@suse.de) wrote:
> On Wed, Jan 31, 2018 at 11:04:07AM +0000, Dr. David Alan Gilbert wrote:
> > That half is the easy bit, we've already got that (thanks to Eduardo),
> > QEMU has -IBRS variants of CPU types, so if you start a VM with
> > -cpu Broadwell-IBRS
> 
> Eww, a CPU model with a specific feature bit. I hope you guys don't add
> a model like that for every CPU feature.

Indeed, it's only for this weird case where you suddenly need to change
it.

Dave

> -- 
> Regards/Gruss,
>     Boris.
> 
> SUSE Linux GmbH, GF: Felix Imend?rffer, Jane Smithard, Graham Norton, HRB 21284 (AG N?rnberg)
> -- 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK