[PATCH v5 1/2] RISC-V: KVM: add tracepoint for guest page faults

[Wang Yechao]

Add the kvm_page_fault event tracepoint to count the number of KVM
guest page faults.

Signed-off-by: Wang Yechao <wang.yechao255@xxxxxxxxxx>
---
 arch/riscv/kvm/trace.h     | 22 ++++++++++++++++++++++
 arch/riscv/kvm/vcpu_exit.c |  2 ++
 2 files changed, 24 insertions(+)

diff --git a/arch/riscv/kvm/trace.h b/arch/riscv/kvm/trace.h
index 23a5fd1b686e..07fcf5b6059b 100644
--- a/arch/riscv/kvm/trace.h
+++ b/arch/riscv/kvm/trace.h
@@ -133,6 +133,28 @@ TRACE_EVENT(kvm_vcpu_irq,
 		  __entry->vcpu_id, __entry->irq, __entry->level)
 );
 
+TRACE_EVENT(kvm_page_fault,
+	TP_PROTO(struct kvm_vcpu *vcpu, u64 fault_address, u64 error_code),
+	TP_ARGS(vcpu, fault_address, error_code),
+
+	TP_STRUCT__entry(
+		__field(unsigned int,   vcpu_id)
+		__field(u64,            fault_address)
+		__field(u64,            error_code)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_id        = vcpu->vcpu_id;
+		__entry->fault_address  = fault_address;
+		__entry->error_code     = error_code;
+	),
+
+	TP_printk("vcpu %u address 0x%016llx error_code 0x%llx",
+		__entry->vcpu_id,
+		__entry->fault_address,
+		__entry->error_code)
+);
+
 #endif /* _TRACE_KVM_H */
 
 #undef TRACE_INCLUDE_PATH
diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
index 88e0c369b354..de0262d0fd95 100644
--- a/arch/riscv/kvm/vcpu_exit.c
+++ b/arch/riscv/kvm/vcpu_exit.c
@@ -29,6 +29,8 @@ static int gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	memslot = gfn_to_memslot(vcpu->kvm, gfn);
 	hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
 
+	trace_kvm_page_fault(vcpu, fault_addr, trap->scause);
+
 	if (kvm_is_error_hva(hva) ||
 	    (trap->scause == EXC_STORE_GUEST_PAGE_FAULT && !writable)) {
 		switch (trap->scause) {
-- 
2.27.0