Question about migrate the vm with host-passthrough cpu

Guoyi Tu tugy at
Wed Feb 24 13:42:37 UTC 2021

Hi there,

Sorry to bother you, but could I ask you a question about the live 
migration of virtual machine configured with host-passthough cpu, it 
confuse me a lot.

Here i have two hosts with different cpu, and the cpu feature set of old
host is subset of the new one (by virsh cpu-compare). If the vm was 
first started on the old host,is it safe to migrate the vm between the 
two hosts back and forth with the vm always keep running?

I've test the case in my environment, and the migration succeeds, the 
cpu family/model/stepping and features of lscpu in Guest OS is the same.

Best Regards,
Guoyi Tu

More information about the libvirt-users mailing list