KVM: trace kvm_ple_window grow/shrink

Tracepoint for dynamic PLE window, fired on every potential change.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/trace.h

@@ -848,6 +848,36 @@ TRACE_EVENT(kvm_track_tsc,
 		  __print_symbolic(__entry->host_clock, host_clocks))
 );
 
+TRACE_EVENT(kvm_ple_window,
+	TP_PROTO(bool grow, unsigned int vcpu_id, int new, int old),
+	TP_ARGS(grow, vcpu_id, new, old),
+
+	TP_STRUCT__entry(
+		__field(                bool,      grow         )
+		__field(        unsigned int,   vcpu_id         )
+		__field(                 int,       new         )
+		__field(                 int,       old         )
+	),
+
+	TP_fast_assign(
+		__entry->grow           = grow;
+		__entry->vcpu_id        = vcpu_id;
+		__entry->new            = new;
+		__entry->old            = old;
+	),
+
+	TP_printk("vcpu %u: ple_window %d (%s %d)",
+	          __entry->vcpu_id,
+	          __entry->new,
+	          __entry->grow ? "grow" : "shrink",
+	          __entry->old)
+);
+
+#define trace_kvm_ple_window_grow(vcpu_id, new, old) \
+	trace_kvm_ple_window(true, vcpu_id, new, old)
+#define trace_kvm_ple_window_shrink(vcpu_id, new, old) \
+	trace_kvm_ple_window(false, vcpu_id, new, old)
+
 #endif /* CONFIG_X86_64 */
 
 #endif /* _TRACE_KVM_H */

arch/x86/kvm/vmx.c

@@ -5738,6 +5738,8 @@ static void grow_ple_window(struct kvm_vcpu *vcpu)
 
 	if (vmx->ple_window != old)
 		vmx->ple_window_dirty = true;
+
+	trace_kvm_ple_window_grow(vcpu->vcpu_id, vmx->ple_window, old);
 }
 
 static void shrink_ple_window(struct kvm_vcpu *vcpu)
@@ -5750,6 +5752,8 @@ static void shrink_ple_window(struct kvm_vcpu *vcpu)
 
 	if (vmx->ple_window != old)
 		vmx->ple_window_dirty = true;
+
+	trace_kvm_ple_window_shrink(vcpu->vcpu_id, vmx->ple_window, old);
 }
 
 /*

arch/x86/kvm/x86.c

@@ -7673,3 +7673,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_invlpga);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_skinit);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_write_tsc_offset);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window);