[dpdk-users] Why kickfd from qemu is zero in qemu-dpdk vhost-user architecture?

[杨晔]

Hello,

I use the "vhost-user" mode in the qemu, and the backend is the dpdk-vhost.

But when I use the eventfd_read(vq->kickfd,&val) function. It always return an error, and the val has always been 0.

The kickfd is the eventfd that passing from qemu to vhost when the vring is set up and calling the vhost_user_set_vring_kick function.

It should be a none-zero value when there are packets in the sending queue.

The virtio-frontend should notify the backend then do the dequeue operation.

Does anyone know about this? I am looking forward to your reply.


Thank you.




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Yang Ye

Network Research Center, Institute of Computing Technology, Chinese Academy of Sciences,

NO.6 Kexueyuan South Road, Zhongguancun, Haidian District, Beijing, China (100190)