[PATCH v2 5/6] KVM: trace kvm_ple_window

["Radim Krčmář" <rkrcmar@redhat.com>]

Tracepoint for dynamic PLE window, fired on every potential change.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
 arch/x86/kvm/trace.h | 25 +++++++++++++++++++++++++
 arch/x86/kvm/vmx.c   |  8 +++++---
 arch/x86/kvm/x86.c   |  1 +
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index e850a7d..4b8e6cb 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -848,6 +848,31 @@ TRACE_EVENT(kvm_track_tsc,
 		  __print_symbolic(__entry->host_clock, host_clocks))
 );
 
+TRACE_EVENT(kvm_ple_window,
+	TP_PROTO(int grow, unsigned int vcpu_id, int new, int old),
+	TP_ARGS(grow, vcpu_id, new, old),
+
+	TP_STRUCT__entry(
+		__field(                 int,      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 ? "<+" : "<-",
+	          __entry->old)
+);
+
 #endif /* CONFIG_X86_64 */
 
 #endif /* _TRACE_KVM_H */
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e63d7ac..f63ac5d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5728,15 +5728,17 @@ static int __shrink_ple_window(int val, int shrinker, int minimum)
 static void modify_ple_window(struct kvm_vcpu *vcpu, int grow)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	int old = vmx->ple_window;
 	int new;
 
 	if (grow)
-		new = __grow_ple_window(vmx->ple_window);
+		new = __grow_ple_window(old)
 	else
-		new = __shrink_ple_window(vmx->ple_window, ple_window_shrink,
-		                          ple_window);
+		new = __shrink_ple_window(old, ple_window_shrink, ple_window);
 
 	vmx->ple_window = max(new, ple_window);
+
+	trace_kvm_ple_window(grow, vcpu->vcpu_id, vmx->ple_window, old);
 }
 #define grow_ple_window(vcpu)   modify_ple_window(vcpu, 1)
 #define shrink_ple_window(vcpu) modify_ple_window(vcpu, 0)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5696ee7..814b20c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7648,3 +7648,4 @@ 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);
-- 
2.0.4