Re: [PATCH RFC 2/2] KVM: x86/vPMU: ignore access to LBR-related MSRs
From: Andi Kleen
Date: Wed Dec 06 2017 - 10:57:41 EST
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