Re: [PATCH] LoongArch: KVM: Add tracepoints for CPUCFG and CSR emulation exits

[Bibo Mao]

On 2025/7/2 下午6:59, Yulong Han wrote:
> This patch adds tracepoints to track KVM exits caused by CPUCFG
> and CSR emulation. Note that IOCSR emulation tracing is already
> covered by the generic trace_kvm_iocsr().
>
> Signed-off-by: Yulong Han <wheatfox17@xxxxxxxxxx>
> ---
>   arch/loongarch/kvm/exit.c  |  2 ++
>   arch/loongarch/kvm/trace.h | 14 +++++++++++++-
>   2 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
> index fa52251b3bf1c..6a47a23ae9cd6 100644
> --- a/arch/loongarch/kvm/exit.c
> +++ b/arch/loongarch/kvm/exit.c
> @@ -289,9 +289,11 @@ static int kvm_trap_handle_gspr(struct kvm_vcpu *vcpu)
>   	er = EMULATE_FAIL;
>   	switch (((inst.word >> 24) & 0xff)) {
>   	case 0x0: /* CPUCFG GSPR */
> +		trace_kvm_exit_cpucfg(vcpu, KVM_TRACE_EXIT_CPUCFG);
>   		er = kvm_emu_cpucfg(vcpu, inst);
>   		break;
>   	case 0x4: /* CSR{RD,WR,XCHG} GSPR */
> +		trace_kvm_exit_csr(vcpu, KVM_TRACE_EXIT_CSR);
>   		er = kvm_handle_csr(vcpu, inst);
>   		break;
>   	case 0x6: /* Cache, Idle and IOCSR GSPR */
> diff --git a/arch/loongarch/kvm/trace.h b/arch/loongarch/kvm/trace.h
> index 1783397b1bc88..145514dab6d5b 100644
> --- a/arch/loongarch/kvm/trace.h
> +++ b/arch/loongarch/kvm/trace.h
> @@ -46,11 +46,15 @@ DEFINE_EVENT(kvm_transition, kvm_out,
>   /* Further exit reasons */
>   #define KVM_TRACE_EXIT_IDLE		64
>   #define KVM_TRACE_EXIT_CACHE		65
> +#define KVM_TRACE_EXIT_CPUCFG		66
> +#define KVM_TRACE_EXIT_CSR		67
>   
>   /* Tracepoints for VM exits */
>   #define kvm_trace_symbol_exit_types			\
>   	{ KVM_TRACE_EXIT_IDLE,		"IDLE" },	\
> -	{ KVM_TRACE_EXIT_CACHE,		"CACHE" }
> +	{ KVM_TRACE_EXIT_CACHE,		"CACHE" },	\
> +	{ KVM_TRACE_EXIT_CPUCFG,	"CPUCFG" },	\
> +	{ KVM_TRACE_EXIT_CSR,		"CSR" }
>   
>   DECLARE_EVENT_CLASS(kvm_exit,
>   	    TP_PROTO(struct kvm_vcpu *vcpu, unsigned int reason),
> @@ -82,6 +86,14 @@ DEFINE_EVENT(kvm_exit, kvm_exit_cache,
>   	     TP_PROTO(struct kvm_vcpu *vcpu, unsigned int reason),
>   	     TP_ARGS(vcpu, reason));
>   
> +DEFINE_EVENT(kvm_exit, kvm_exit_cpucfg,
> +	     TP_PROTO(struct kvm_vcpu *vcpu, unsigned int reason),
> +	     TP_ARGS(vcpu, reason));
> +
> +DEFINE_EVENT(kvm_exit, kvm_exit_csr,
> +	     TP_PROTO(struct kvm_vcpu *vcpu, unsigned int reason),
> +	     TP_ARGS(vcpu, reason));
> +
>   DEFINE_EVENT(kvm_exit, kvm_exit,
>   	     TP_PROTO(struct kvm_vcpu *vcpu, unsigned int reason),
>   	     TP_ARGS(vcpu, reason));
Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>