RISCV: KVM: add tracepoints for entry and exit events

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>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20240422080833.8745-2-liangshenlin@eswincomputing.com
Signed-off-by: Anup Patel <anup@brainfault.org>

diff --git a/arch/riscv/kvm/trace.h b/arch/riscv/kvm/trace.h
new file mode 100644 (file)
index 0000000..3d54175
--- /dev/null
+++ b/arch/riscv/kvm/trace.h
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tracepoints for RISC-V KVM
+ *
+ * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
+ *
+ */
+#if !defined(_TRACE_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_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: 0x016%lx", __entry->pc)
+);
+
+TRACE_EVENT(kvm_exit,
+       TP_PROTO(struct kvm_cpu_trap *trap),
+       TP_ARGS(trap),
+
+       TP_STRUCT__entry(
+               __field(unsigned long, sepc)
+               __field(unsigned long, scause)
+               __field(unsigned long, stval)
+               __field(unsigned long, htval)
+               __field(unsigned long, htinst)
+       ),
+
+       TP_fast_assign(
+               __entry->sepc           = trap->sepc;
+               __entry->scause         = trap->scause;
+               __entry->stval          = trap->stval;
+               __entry->htval          = trap->htval;
+               __entry->htinst         = trap->htinst;
+       ),
+
+       TP_printk("SEPC:0x%lx, SCAUSE:0x%lx, STVAL:0x%lx, HTVAL:0x%lx, HTINST:0x%lx",
+               __entry->sepc,
+               __entry->scause,
+               __entry->stval,
+               __entry->htval,
+               __entry->htinst)
+);
+
+#endif /* _TRACE_RSICV_KVM_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace
+
+/* 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 17e21df36cc1ec3501435a5cf57dd4bfac24fdd8..bc15df3119c3d5af62056b4f51db89a4b50ae037 100644 (file)
--- 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.h"
+
 const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
        KVM_GENERIC_VCPU_STATS(),
        STATS_DESC_COUNTER(VCPU, ecall_exit_stat),
@@ -831,6 +834,8 @@ 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);
@@ -869,6 +874,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 
                local_irq_enable();
 
+               trace_kvm_exit(&trap);
+
                preempt_enable();
 
                kvm_vcpu_srcu_read_lock(vcpu);