message: Readme: Add short section on how to use virtio-fs
diff: @@ -169,6 +169,28 @@ $ qemu-system-x86_64 -display none -smp 1 -m 64M -serial stdio -kernel path_to_
  It is important to enable the processor features _fsgsbase_ and _rdtscp_ because it is a prerequisite to boot RustyHermit.
  +### Using virtio-fs
  +
  +The Kernel has rudimentary support for the virtio-fs shared file system. Currently only files, no folders are supported. To use it, you have to run a virtio-fs daemon and start qemu as described in [Standalone virtio-fs usage](https://virtio-fs.gitlab.io/howto-qemu.html):
  +
  +```bash
  +# start virtiofsd in the background
  +$ sudo virtiofsd --thread-pool-size=1 --socket-path=/tmp/vhostqemu -o source=$(pwd)/SHARED_DIRECTORY
  +# give non-root-users access to the socket
  +$ sudo chmod 777 /tmp/vhostqemu
  +# start qemu with virtio-fs device.
  +# you might want to change the socket (/tmp/vhostqemu) and virtiofs tag (currently myfs)
  +$ qemu-system-x86_64 -cpu qemu64,apic,fsgsbase,rdtscp,xsave,fxsr -enable-kvm -display none -smp 1 -m 1G -serial stdio \
  + -kernel path_to_loader/rusty-loader \
  + -initrd path_to_app/app \
  + -chardev socket,id=char0,path=/tmp/vhostqemu \
  + -device vhost-user-fs-pci,queue-size=1024,chardev=char0,tag=myfs \
  + -object memory-backend-file,id=mem,size=1G,mem-path=/dev/shm,share=on \
  + -numa node,memdev=mem
  +```
  +
  +You can now access the files in SHARED_DIRECTORY under the virtiofs tag like `/myfs/testfile`.
  +
  ## Extending RustyHermit
  The best way to extend the kernel is to work with the branch *devel* of the repository [rusty-hermit](https://github.com/hermitcore/rusty-hermit).
  