Display right disk size in micro vms

[AbdelrahmanElawady]

Currently, displaying file system space usage with something like df outputs the host file system details not the VM. So, a VM with 10 GB of storage could show multiple Terabytes for example as available. While the VM can't utilize any thing more than this 10 GB, still it would be better to show data only relevant to the VM not the host system.

virtiofsd is being used to manage the filesystem of the VM. it is built on FUSE we can utilize that to report the right size with a --size-hint option and modify the right function call to show the right details.