From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH RFC 2/2] KVM: x86/vPMU: ignore access to LBR-related MSRs
Date: Wed, 6 Dec 2017 07:57:28 -0800
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Cc: linux-kernel@vger.kernel.org,
        "Denis V . Lunev" <den@virtuozzo.com>,
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        Peter Zijlstra <peterz@infradead.org>,
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        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
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If you do all this it's only a small step to fully enable LBRs for guests. 

Just need to allow them to be written, expose PERF_CAPABILITIES too, and
start/stop them on entry/exit, and enable context switching through perf in
the host.

That would be far better than creating a frankenstate where LBR is there but
mostly broken on some KVM versions.

-Andi