[RFC PATCH 4/4] KVM: arm64: Add trace for TWED update

[Jingyi Wang]

From: Zengruan Ye <yezengruan at huawei.com>

Add tracepoints for TWE delay value update

Signed-off-by: Zengruan Ye <yezengruan at huawei.com>
Signed-off-by: Jingyi Wang <wangjingyi11 at huawei.com>
---
 arch/arm64/kvm/arm.c       |  4 ++++
 arch/arm64/kvm/trace_arm.h | 21 +++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 989bffdcb3e9..c3d7a326bf1b 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -80,6 +80,8 @@ void grow_twed(struct kvm_vcpu *vcpu)
 		vcpu->arch.twed += 1;
 		vcpu->arch.twed_dirty = true;
 	}
+
+	trace_kvm_twed_update(vcpu->vcpu_id, vcpu->arch.twed, old);
 }
 
 void shrink_twed(struct kvm_vcpu *vcpu)
@@ -90,6 +92,8 @@ void shrink_twed(struct kvm_vcpu *vcpu)
 		vcpu->arch.twed -= 1;
 		vcpu->arch.twed_dirty = true;
 	}
+
+	trace_kvm_twed_update(vcpu->vcpu_id, vcpu->arch.twed, old);
 }
 #endif
 
diff --git a/arch/arm64/kvm/trace_arm.h b/arch/arm64/kvm/trace_arm.h
index ff0444352bba..5081266399e8 100644
--- a/arch/arm64/kvm/trace_arm.h
+++ b/arch/arm64/kvm/trace_arm.h
@@ -367,6 +367,27 @@ TRACE_EVENT(kvm_timer_emulate,
 		  __entry->timer_idx, __entry->should_fire)
 );
 
+TRACE_EVENT(kvm_twed_update,
+	TP_PROTO(unsigned int vcpu_id, unsigned int new, unsigned int old),
+	TP_ARGS(vcpu_id, new, old),
+
+	TP_STRUCT__entry(
+		__field(	unsigned int,	vcpu_id		)
+		__field(	unsigned int,	new		)
+		__field(	unsigned int,	old		)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_id	= vcpu_id;
+		__entry->new		= new;
+		__entry->old		= old;
+	),
+
+	TP_printk("vcpu %u old %u new %u (%s)",
+		  __entry->vcpu_id, __entry->old, __entry->new,
+		  __entry->old < __entry->new ? "growed" : "shrinked")
+);
+
 #endif /* _TRACE_ARM_ARM64_KVM_H */
 
 #undef TRACE_INCLUDE_PATH
-- 
2.19.1