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| author | Joerg Roedel <joerg.roedel@amd.com> | 2012-02-29 14:57:32 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2012-03-02 12:16:39 +0100 |
| commit | 1018faa6cf23b256bf25919ef203cd7c129f06f2 (patch) | |
| tree | 16f8f223062c41e29431edfa71e66832101dee4e /arch/x86/kvm/svm.c | |
| parent | 5d85d97c9f6973ba854f35a2d5e80fe68272143e (diff) | |
| download | linux-1018faa6cf23b256bf25919ef203cd7c129f06f2.tar.gz | |
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/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 5fa553babe56..e385214711cb 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -29,6 +29,7 @@ #include <linux/ftrace_event.h> #include <linux/slab.h> +#include <asm/perf_event.h> #include <asm/tlbflush.h> #include <asm/desc.h> #include <asm/kvm_para.h> @@ -575,6 +576,8 @@ static void svm_hardware_disable(void *garbage) wrmsrl(MSR_AMD64_TSC_RATIO, TSC_RATIO_DEFAULT); cpu_svm_disable(); + + amd_pmu_disable_virt(); } static int svm_hardware_enable(void *garbage) @@ -622,6 +625,8 @@ static int svm_hardware_enable(void *garbage) svm_init_erratum_383(); + amd_pmu_enable_virt(); + return 0; } |