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authorJoerg Roedel <joerg.roedel@amd.com>2012-02-29 14:57:32 +0100
committerIngo Molnar <mingo@elte.hu>2012-03-02 12:16:39 +0100
commit1018faa6cf23b256bf25919ef203cd7c129f06f2 (patch)
tree16f8f223062c41e29431edfa71e66832101dee4e /arch/x86/include
parent5d85d97c9f6973ba854f35a2d5e80fe68272143e (diff)
perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled
It turned out that a performance counter on AMD does not count at all when the GO or HO bit is set in the control register and SVM is disabled in EFER. This patch works around this issue by masking out the HO bit in the performance counter control register when SVM is not enabled. The GO bit is not touched because it is only set when the user wants to count in guest-mode only. So when SVM is disabled the counter should not run at all and the not-counting is the intended behaviour. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Avi Kivity <avi@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: David Ahern <dsahern@gmail.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Robert Richter <robert.richter@amd.com> Cc: stable@vger.kernel.org # v3.2 Link: http://lkml.kernel.org/r/1330523852-19566-1-git-send-email-joerg.roedel@amd.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/perf_event.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 096c975e099..461ce432b1c 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -242,4 +242,12 @@ static inline void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
static inline void perf_events_lapic_init(void) { }
#endif
+#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD)
+ extern void amd_pmu_enable_virt(void);
+ extern void amd_pmu_disable_virt(void);
+#else
+ static inline void amd_pmu_enable_virt(void) { }
+ static inline void amd_pmu_disable_virt(void) { }
+#endif
+
#endif /* _ASM_X86_PERF_EVENT_H */