The migration metrics works flaky:
kubevirt_vmi_migration_data_processed_bytes
kubevirt_vmi_migration_data_remaining_bytes
kubevirt_vmi_migration_disk_transfer_rate_bytes
kubevirt_vmi_migration_dirty_memory_rate_bytes
kubevirt_vmi_migration_data_total_bytes

1.Create a migratable vm
2.Create Migrationpolicy with low bandwidth
3.Check that these metrics has any value.

None

Some value for the vm that migarated.

The prometheus catch every 30 seconds so the migration has to take more than 30 seconds so it will catch the data and report it.
In my case it took almost a minute for the migration but still I am not getting value all the time.