From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: perf uncore & lkvm woes
Date: Thu, 16 Aug 2012 13:17:26 +0200
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Cc: Pekka Enberg <penberg@kernel.org>,
	"Yan, Zheng" <zheng.z.yan@linux.intel.com>,
	Sasha Levin <levinsasha928@gmail.com>,
	Asias He <asias.hejun@gmail.com>,
	Cyrill Gorcunov <gorcunov@gmail.com>,
	Ingo Molnar <mingo@elte.hu>, KVM General <kvm@vger.kernel.org>,
	Gleb Natapov <gleb@redhat.com>
To: Avi Kivity <avi@redhat.com>
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On Thu, 2012-08-16 at 14:06 +0300, Avi Kivity wrote:

> Another option is to deal with them on the host side.  That has the
> benefit of working with non-Linux guests too.

Right, its an insane amount of MSRs though, but it could be done if
someone takes the time to enumerate them all.

If KVM then simply ignores all writes and returns all 0 on read we can
do the same we do for the regular PMU in check_hw_exists().

> We can just ignore the MSR and print some warning.

If you don't mind printing a warning every time a Linux guest boots ;-)