Hi, During live migration, the folloing log can see in nova-compute.log in my environment: ERROR nova.virt.libvirt.driver [req-039a85e1-e7a1-4a63-bc6d-c4b9a044aab6 0cdab20dc79f4bc6ae5790e7b4a898ac 3363c319773549178acc67f32c78310e - default default] [instance: 5ec719f4-1865-4afe-a207-3d9fae22c410] Live Migration failure: internal error: qemu unexpectedly closed the monitor: 2019-04-15T02:58:22.213897Z qemu-kvm: VQ 0 size 0x100 < last_avail_idx 0x1e - used_idx 0x23
It's OK for standard Linux VM, but not OK for our VM where virtio is implemented by ourself. KVM version as follow: qemu-kvm-common-ev-2.12.0-18.el7_6.3.1.x86_64 qemu-kvm-ev-2.12.0-18.el7_6.3.1.x86_64 libvirt-daemon-kvm-3.9.0-14.2.el7.centos.ncir.8.x86_64 Do you know what's the difference between virtio and vhost-user during migration? The function virtio_load in Qemu is called for virtio and vhost-user during migration. For virtio, last_avail_idx and used_idx are stored in Qemu, Qemu is responsible for updating their values accordingly For vhost-user, last_avail_idx and used_idx are stored in vhost-user app, eg. DPDK, not in Qemu? How does migration work for vhost-user? Thanks in advance Yafeng
