VM configs (`/nodes/{node}/qemu/{vmid}/config`) contain configuration strings, such as:
local-zfs:vm-100-disk-1,aio=native,cache=unsafe,discard=on,iops_rd=20,iops_rd_max=30,iops_wr=20,iops_wr_max=30,iothread=1,mbps_rd=5,mbps_rd_max=10,mbps_wr=5,mbps_wr_max=10,replicate=0,ro=1,size=20G,ssd=1...