[PATCH 1/2] RISCV: KVM: add tracepoints for entry and exit events

Shenlin Liang
2024-03-28T03:20:35Z

Like other architectures, RISCV KVM also needs to add these event
tracepoints to count the number of times kvm guest entry/exit.

Signed-off-by: Shenlin Liang <liangshenlin@eswincomputing.com>
---
arch/riscv/kvm/trace_riscv.h | 60 ++++++++++++++++++++++++++++++++++++
arch/riscv/kvm/vcpu.c | 7 +++++
2 files changed, 67 insertions(+)
create mode 100644 arch/riscv/kvm/trace_riscv.h

diff --git a/arch/riscv/kvm/trace_riscv.h b/arch/riscv/kvm/trace_riscv.h
new file mode 100644
index 000000000000..5848083c7a5e
--- /dev/null
+++ b/arch/riscv/kvm/trace_riscv.h
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tracepoints for RISC-V KVM
+ *
+ * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
+ *
+ */
+#if !defined(_TRACE_RSICV_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_RSICV_KVM_H
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM kvm
+
+TRACE_EVENT(kvm_entry,
+ TP_PROTO(struct kvm_vcpu *vcpu),
+ TP_ARGS(vcpu),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, pc)
+ ),
+
+ TP_fast_assign(
+ __entry->pc = vcpu->arch.guest_context.sepc;
+ ),
+
+ TP_printk("PC: 0x%016lx", __entry->pc)
+);
+
+TRACE_EVENT(kvm_exit,
+ TP_PROTO(struct kvm_vcpu *vcpu, unsigned long exit_reason,
+ unsigned long scause),
+ TP_ARGS(vcpu, exit_reason, scause),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, pc)
+ __field(unsigned long, exit_reason)
+ __field(unsigned long, scause)
+ ),
+
+ TP_fast_assign(
+ __entry->pc = vcpu->arch.guest_context.sepc;
+ __entry->exit_reason = exit_reason;
+ __entry->scause = scause;
+ ),
+
+ TP_printk("EXIT_REASON:0x%lx,PC: 0x%016lx,SCAUSE:0x%lx",
+ __entry->exit_reason, __entry->pc, __entry->scause)
+);
+
+#endif /* _TRACE_RSICV_KVM_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace_riscv
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index b5ca9f2e98ac..ed0932f0d514 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -21,6 +21,9 @@
#include <asm/cacheflush.h>
#include <asm/kvm_vcpu_vector.h>

+#define CREATE_TRACE_POINTS
+#include "trace_riscv.h"
+
const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
KVM_GENERIC_VCPU_STATS(),
STATS_DESC_COUNTER(VCPU, ecall_exit_stat),
@@ -782,6 +785,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
*/
kvm_riscv_local_tlb_sanitize(vcpu);

+ trace_kvm_entry(vcpu);
+
guest_timing_enter_irqoff();

kvm_riscv_vcpu_enter_exit(vcpu);
@@ -820,6 +825,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)

local_irq_enable();

+ trace_kvm_exit(vcpu, run->exit_reason, trap.scause);
+
preempt_enable();

kvm_vcpu_srcu_read_lock(vcpu);
--
2.37.2