Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled

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 096c975e099f..461ce432b1c2 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 8944062f46e2..c30c807ddc72 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 0397b23be8e9..67250a52430b 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 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;
 }