diff options
| author | Joerg Roedel <joerg.roedel@amd.com> | 2012-02-29 14:57:32 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-03-12 12:31:23 -0700 |
| commit | 9701e4af7147129671f1946794e52f6abcd6f17a (patch) | |
| tree | 261788ccb7fe410719c717a9b5ee68991eb64c18 /arch/x86/include | |
| parent | 5798b013af929124c7ec9872719bf94e93c4a923 (diff) | |
perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled
commit 1018faa6cf23b256bf25919ef203cd7c129f06f2 upstream.
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>
Link: http://lkml.kernel.org/r/1330523852-19566-1-git-send-email-joerg.roedel@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/perf_event.h | 8 |
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 f61c62f7d5d8..50d7ff2cab3e 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -212,4 +212,12 @@ static inline perf_guest_switch_msr *perf_guest_get_msrs(int *nr) 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 */ |