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Commit c9b08884 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Thomas Gleixner
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perf/x86: Correctly use FEATURE_PDCM



The current code simply assumes Intel Arch PerfMon v2+ to have
the IA32_PERF_CAPABILITIES MSR; the SDM specifies that we should check
CPUID[1].ECX[15] (aka, FEATURE_PDCM) instead.

This was found by KVM which implements v2+ but didn't provide the
capabilities MSR. Change the code to DTRT; KVM will also implement the
MSR and return 0.

Cc: pbonzini@redhat.com
Reported-by: default avatar"Michael S. Tsirkin" <mst@redhat.com>
Suggested-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140203132903.GI8874@twins.programming.kicks-ass.net


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent a3ef2229
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