Hi Tetsuya, In my test I created 2 vdev using "--vdev 'eth_vhost0,iface=/tmp/sock0,queues=1' --vdev 'eth_vhost1,iface=/tmp/sock1,queues=1'", and the qemu message got handled in wrong order. The reason is that: 2 threads are created to handle message from 2 sockets, but their fds are SHARED, so each thread are reading from both sockets.
This can lead to incorrect behaviors, in my case sometimes the VHOST_USER_SET_MEM_TABLE got handled after VRING initialization and lead to destroy_device(). Detailed log as shown below: thread 69351 & 69352 are both reading fd 25. Thanks Yuanhan for helping debugging! Thanks Zhihong ----------------------------------------------------------------------------------------------------------------- ----> debug: setting up new vq conn for fd: 23, tid: 69352 VHOST_CONFIG: new virtio connection is 25 VHOST_CONFIG: new device, handle is 0 ----> debug: vserver_message_handler thread id: 69352, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_OWNER ----> debug: vserver_message_handler thread id: 69352, fd: 25 VHOST_CONFIG: read message VHOST_USER_GET_FEATURES ----> debug: vserver_message_handler thread id: 69352, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_CALL VHOST_CONFIG: vring call idx:0 file:26 ----> debug: vserver_message_handler thread id: 69352, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_CALL VHOST_CONFIG: vring call idx:1 file:27 ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_CALL VHOST_CONFIG: vring call idx:0 file:28 ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_CALL VHOST_CONFIG: vring call idx:1 file:26 ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_FEATURES ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_MEM_TABLE ----> debug: device_fh: 0: user_set_mem_table VHOST_CONFIG: mapped region 0 fd:27 to 0x7ff6c0000000 sz:0xa0000 off:0x0 VHOST_CONFIG: mapped region 1 fd:29 to 0x7ff680000000 sz:0x40000000 off:0xc0000 ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_NUM ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_BASE ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_ADDR ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_KICK VHOST_CONFIG: vring kick idx:0 file:30 ----> debug: vserver_message_handler thread id: 69352, fd: 25 VHOST_CONFIG: virtio is not ready for processing. ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_BASE ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_ADDR ----> debug: vserver_message_handler thread id: 69351, fd: 25 VHOST_CONFIG: read message VHOST_USER_SET_VRING_KICK VHOST_CONFIG: vring kick idx:1 file:31 VHOST_CONFIG: virtio is now ready for processing. PMD: New connection established VHOST_CONFIG: read message VHOST_USER_SET_VRING_NUM ----------------------------------------------------------------------------------------------------------------- > ... > + > +static void *vhost_driver_session(void *param __rte_unused) > +{ > + static struct virtio_net_device_ops *vhost_ops; > + > + vhost_ops = rte_zmalloc(NULL, sizeof(*vhost_ops), 0); > + if (vhost_ops == NULL) > + rte_panic("Can't allocate memory\n"); > + > + /* set vhost arguments */ > + vhost_ops->new_device = new_device; > + vhost_ops->destroy_device = destroy_device; > + if (rte_vhost_driver_pmd_callback_register(vhost_ops) < 0) > + rte_panic("Can't register callbacks\n"); > + > + /* start event handling */ > + rte_vhost_driver_session_start(); > + > + rte_free(vhost_ops); > + pthread_exit(0); > +} > + > +static void vhost_driver_session_start(struct pmd_internal *internal) > +{ > + int ret; > + > + ret = pthread_create(&internal->session_th, > + NULL, vhost_driver_session, NULL); > + if (ret) > + rte_panic("Can't create a thread\n"); > +} > + > ...