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Date:   Wed, 31 Jan 2018 17:28:46 +0100
From:   Borislav Petkov <bp@suse.de>
To:     Eduardo Habkost <ehabkost@redhat.com>
Cc:     "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
        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>,
        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>,
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        Dave Hansen <dave.hansen@intel.com>,
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Subject: Re: [RFC,05/10] x86/speculation: Add basic IBRS support
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On Wed, Jan 31, 2018 at 12:44:41PM -0200, Eduardo Habkost wrote:
> Also, if anybody don't like it, users can already specify, e.g.,
> "Broadwell,-hle,-rtm" or "Skylake,+spec_ctrl".
> 
> QEMU only adds have the -noTSX and -IBRS CPU for convenience of
> management systems that don't know how to check/configure
> individual CPU features.  We're working with libvirt and
> OpenStack folks to make this kind of trick unnecessary.

Yeah, defining separate CPU models just for that seems hacky. The
+/-<feature> specification looks like the Right Thing(tm) to do.

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--