From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH v6 2/5] KVM: x86: Add IBPB support
Date: Fri, 2 Feb 2018 20:52:58 +0000
Message-ID: <20180202205258.2819b14f@alans-desktop>
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Cc: David Woodhouse <dwmw2@infradead.org>,
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        Andrea Arcangeli <aarcange@redhat.com>,
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        Dan Williams <dan.j.williams@intel.com>,
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        Greg KH <gregkh@linuxfoundation.org>,
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To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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> > No. The AMD feature bits give us more fine-grained support for exposing
> > IBPB or IBRS alone, so we expose those bits on Intel too.  
> 
> But but.. that runs smack against the idea of exposing a platform that
> is as close to emulating the real hardware as possible.

Agreed, and it's asking for problems in the future if for example Intel
or another non AMD vendor did ever use that leaf for something different.

Now whether there ought to be an MSR range every vendor agrees is never
implemented so software can use it is an interesting discussion.

Alan