From: Tang Longjun <[email protected]> introduces the building and running methods of virtnet_mon, and also explains the key implementation points.
Signed-off-by: Tang Longjun <[email protected]> --- tools/virtio/virtnet_mon/README | 35 +++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 tools/virtio/virtnet_mon/README diff --git a/tools/virtio/virtnet_mon/README b/tools/virtio/virtnet_mon/README new file mode 100644 index 000000000000..a1f6a5ebd219 --- /dev/null +++ b/tools/virtio/virtnet_mon/README @@ -0,0 +1,35 @@ +virtnet_mon is used to monitor the data packets of the virtio_net driver and the related parameters of virtqueue, useful for tracking its status and troubleshooting faults. + +Build and Execution +=============== +）Build and Execution +$ make +2）Load virtnet_mon +$ insmod virtnet_mon.ko +3）Obtain log +$ tail -f /dev/virtnet_mon | tee -a log + + +Example +======= +76748.877337321 cpu=5 dir=TX event_type=SKB_XMIT_DONE_PRE_EVENT vq=0xffff0000c43e0800 queue=output.2 num_free=255 num=256 avail_flags=0 avail_idx=17411 avail_flags_shadow=0 avail_idx_shadow=17411 used_flags=0 used_idx=17411 last_used_idx=17410 broken=0 +76749.357149745 cpu=4 dir=RX event_type=GRO_RECEIVE_SKB_PRE_EVENT vq=0xffff0000c43e0d00 queue=input.2 num_free=4 num=256 avail_flags=0 avail_idx=57294 avail_flags_shadow=1 avail_idx_shadow=57294 used_flags=1 used_idx=57042 last_used_idx=57042 broken=0 +76749.750030740 cpu=4 dir=TX event_type=START_XMIT_PRE_EVENT skb=0xffff0000d354f700 proto=Unknown seq=0 vq=0xffff0000c43e0800 queue=output.2 num_free=256 num=256 avail_flags=0 avail_idx=17411 avail_flags_shadow=0 avail_idx_shadow=17411 used_flags=0 used_idx=17411 last_used_idx=17411 broken=0 + + +Implementation Key Points of virtnet_mon +================================ +1）Create a misc type driver for transferring log information between user space and kernel space. +2）Introduce kfifo buffers to support more frequent log output or file writing. +3）Use kprobe to trace the functional interfaces of virtio_net to obtain the relevant parameters of skb and virtqueue. + + +Next Steps +======== +1）Add real-time monitor of skb and virtqueue parameters to promptly report faults, such as: + a) virtqueue.broken + b) virtqueue.num_free + c) vring used.idx + d) ... +2）Support dynamic control to enable/disable functions through echo xxx > /dev/virtnet_mon. +3）More comprehensive monitoring information virtnet_mon_pkt_info. -- 2.43.0
