nvmet: add async event tracing support

This adds a new tracepoint for the target to trace async event. This is
helpful in debugging and comparing host and target side async events
especially when host is connected to different targets on different
machines and now that we rely on userspace components to generate AEN. 

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index b685f99d56a1fb2359b08091d937c9910d3dd93f..7ce3d3b0f5d6cff76a44361f1e7746503976051c 100644 (file)
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -151,6 +151,7 @@ static void nvmet_async_events_process(struct nvmet_ctrl *ctrl, u16 status)
                kfree(aen);
 
                mutex_unlock(&ctrl->lock);
+               trace_nvmet_async_event(ctrl, req->cqe->result.u32);
                nvmet_req_complete(req, status);
        }
 }

diff --git a/drivers/nvme/target/trace.h b/drivers/nvme/target/trace.h
index e645caa882dd3ed31625f70d971353ed152fc198..0458046d650178b7a620a20b678ceeb1ba2a0292 100644 (file)
--- a/drivers/nvme/target/trace.h
+++ b/drivers/nvme/target/trace.h
@@ -130,6 +130,34 @@ TRACE_EVENT(nvmet_req_complete,
 
 );
 
+#define aer_name(aer) { aer, #aer }
+
+TRACE_EVENT(nvmet_async_event,
+       TP_PROTO(struct nvmet_ctrl *ctrl, __le32 result),
+       TP_ARGS(ctrl, result),
+       TP_STRUCT__entry(
+               __field(int, ctrl_id)
+               __field(u32, result)
+       ),
+       TP_fast_assign(
+               __entry->ctrl_id = ctrl->cntlid;
+               __entry->result = (le32_to_cpu(result) & 0xff00) >> 8;
+       ),
+       TP_printk("nvmet%d: NVME_AEN=%#08x [%s]",
+               __entry->ctrl_id, __entry->result,
+               __print_symbolic(__entry->result,
+               aer_name(NVME_AER_NOTICE_NS_CHANGED),
+               aer_name(NVME_AER_NOTICE_ANA),
+               aer_name(NVME_AER_NOTICE_FW_ACT_STARTING),
+               aer_name(NVME_AER_NOTICE_DISC_CHANGED),
+               aer_name(NVME_AER_ERROR),
+               aer_name(NVME_AER_SMART),
+               aer_name(NVME_AER_CSS),
+               aer_name(NVME_AER_VS))
+       )
+);
+#undef aer_name
+
 #endif /* _TRACE_NVMET_H */
 
 #undef TRACE_INCLUDE_PATH