Thanks Michal and Peter for your response. I‘ m running it on qemu 5.1 build by myself. BTW, follow Peter’s suggestion, where I can get the latest rpms if I want to upgrade to Libvirt 7.1? As I know it seems need more than twenty related rpms not include dependency. > 在 2021年5月14日,21:15,Michal Prívozník <mprivozn@xxxxxxxxxx> 写道: > > On 5/14/21 8:33 AM, Liang Chaojun wrote: >> >> >> Thanks,I have tried qemu monitor as below. I used chardev_add to add a chardev and used device_add it to running vm. But i often hit a issue and cause the vm crash. qemu-system-x86_64: ../hw/virtio/vhost.c:1566: vhost_dev_get_config: Assertion `hdev->vhost_ops' failed. >> >> virsh qemu-monitor-command spdk1 --hmp --cmd "chardev-add socket,id=spdk_vhost_blk0,path=/var/tmp/vhost.0,reconnect=1" virsh qemu-monitor-command spdk1 --hmp --cmd "device_add vhost-user-blk-pci,chardev=spdk_vhost_blk0,num-queues=4" > > Smells like problem described here: > > https://gitlab.com/qemu-project/qemu/-/commit/bc79c87bcde6587a37347f81332fbb0cd6b14b85 > > But that's pretty fresh commit (part of qemu 6.0.0 release). And also > the commit it references is not that old (qemu 5.1.0 release). What > version of qemu are >