KVM: trace guest fpu loads and unloads

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/x86.c

@@ -5292,6 +5292,7 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
 	vcpu->guest_fpu_loaded = 1;
 	kvm_fx_save(&vcpu->arch.host_fx_image);
 	kvm_fx_restore(&vcpu->arch.guest_fx_image);
+	trace_kvm_fpu(1);
 }
 
 void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
@@ -5304,6 +5305,7 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
 	kvm_fx_restore(&vcpu->arch.host_fx_image);
 	++vcpu->stat.fpu_reload;
 	set_bit(KVM_REQ_DEACTIVATE_FPU, &vcpu->requests);
+	trace_kvm_fpu(0);
 }
 
 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)

include/trace/events/kvm.h

@@ -145,6 +145,25 @@ TRACE_EVENT(kvm_mmio,
 		  __entry->len, __entry->gpa, __entry->val)
 );
 
+#define kvm_fpu_load_symbol	\
+	{0, "unload"},		\
+	{1, "load"}
+
+TRACE_EVENT(kvm_fpu,
+	TP_PROTO(int load),
+	TP_ARGS(load),
+
+	TP_STRUCT__entry(
+		__field(	u32,	        load		)
+	),
+
+	TP_fast_assign(
+		__entry->load		= load;
+	),
+
+	TP_printk("%s", __print_symbolic(__entry->load, kvm_fpu_load_symbol))
+);
+
 #endif /* _TRACE_KVM_MAIN_H */
 
 /* This part must be outside protection */