From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH v1 0/4] Enable LBR for the guest
Date: Tue, 26 Sep 2017 09:51:37 -0700
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Cc: virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
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To: Wei Wang <wei.w.wang@intel.com>
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> On the other side, it seems that the (guest) kernel driver also works
> without
> the above being supported, should we change it to report error and stop
> using the PMU features when the check of the above two fails (at
> intel_pmu_init())?

You could add the extra check for the LBR code yes, although it already checks
if the LBR MSRs work, so in practice it's likely already covered.

-Andi