Update: I rebooted and my KVM can't boot anymore:
kvm: -drive file=/dev/zvol/rpool/data/vm-250-disk-1,if=none,id=drive-scsi0,discard=on,format=raw,cache=none,aio=native,detect-zeroes=unmap: Could not open '/dev/zvol/rpool/data/vm-250-disk-1': No such file or directory
sudo zpool list
NAME...