[GIT PULL] perf fix

From: Ingo Molnar
Date: Sat Mar 03 2012 - 02:51:40 EST


Linus,

Please pull the latest perf-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus

HEAD: 1018faa6cf23b256bf25919ef203cd7c129f06f2 perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled

Thanks,

Ingo

------------------>
Joerg Roedel (1):
perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled


arch/x86/include/asm/perf_event.h | 8 +++++++
arch/x86/kernel/cpu/perf_event.h | 8 +++++-
arch/x86/kernel/cpu/perf_event_amd.c | 37 ++++++++++++++++++++++++++++++++-
arch/x86/kvm/svm.c | 5 ++++
4 files changed, 54 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 096c975..461ce43 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 */
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 8944062..c30c807 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -147,7 +147,9 @@ struct cpu_hw_events {
/*
* AMD specific bits
*/
- struct amd_nb *amd_nb;
+ struct amd_nb *amd_nb;
+ /* Inverted mask of bits to clear in the perf_ctr ctrl registers */
+ u64 perf_ctr_virt_mask;

void *kfree_on_online;
};
@@ -417,9 +419,11 @@ void x86_pmu_disable_all(void);
static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc,
u64 enable_mask)
{
+ u64 disable_mask = __this_cpu_read(cpu_hw_events.perf_ctr_virt_mask);
+
if (hwc->extra_reg.reg)
wrmsrl(hwc->extra_reg.reg, hwc->extra_reg.config);
- wrmsrl(hwc->config_base, hwc->config | enable_mask);
+ wrmsrl(hwc->config_base, (hwc->config | enable_mask) & ~disable_mask);
}

void x86_pmu_enable_all(int added);
diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 0397b23..67250a5 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -1,4 +1,5 @@
#include <linux/perf_event.h>
+#include <linux/export.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/slab.h>
@@ -357,7 +358,9 @@ static void amd_pmu_cpu_starting(int cpu)
struct amd_nb *nb;
int i, nb_id;

- if (boot_cpu_data.x86_max_cores < 2)
+ cpuc->perf_ctr_virt_mask = AMD_PERFMON_EVENTSEL_HOSTONLY;
+
+ if (boot_cpu_data.x86_max_cores < 2 || boot_cpu_data.x86 == 0x15)
return;

nb_id = amd_get_nb_id(cpu);
@@ -587,9 +590,9 @@ static __initconst const struct x86_pmu amd_pmu_f15h = {
.put_event_constraints = amd_put_event_constraints,

.cpu_prepare = amd_pmu_cpu_prepare,
- .cpu_starting = amd_pmu_cpu_starting,
.cpu_dead = amd_pmu_cpu_dead,
#endif
+ .cpu_starting = amd_pmu_cpu_starting,
};

__init int amd_pmu_init(void)
@@ -621,3 +624,33 @@ __init int amd_pmu_init(void)

return 0;
}
+
+void amd_pmu_enable_virt(void)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+ cpuc->perf_ctr_virt_mask = 0;
+
+ /* Reload all events */
+ x86_pmu_disable_all();
+ x86_pmu_enable_all(0);
+}
+EXPORT_SYMBOL_GPL(amd_pmu_enable_virt);
+
+void amd_pmu_disable_virt(void)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+ /*
+ * We only mask out the Host-only bit so that host-only counting works
+ * when SVM is disabled. If someone sets up a guest-only counter when
+ * SVM is disabled the Guest-only bits still gets set and the counter
+ * will not count anything.
+ */
+ cpuc->perf_ctr_virt_mask = AMD_PERFMON_EVENTSEL_HOSTONLY;
+
+ /* Reload all events */
+ x86_pmu_disable_all();
+ x86_pmu_enable_all(0);
+}
+EXPORT_SYMBOL_GPL(amd_pmu_disable_virt);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 5fa553b..e385214 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;
}

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