+++ This bug was initially created as a clone of Bug #1121780 +++ Description of problem: Export host file systems to KVM guests using MTP (Media Transfer Protocol), by using the usb-mtp device in QEMU. The virtfs project, led by IBM, was never included in RHEL/KVM. It cannot be used as a general passthrough file system due to lack of Windows guest support. There was also some other concerns listed in BZ 729054, including the move MTP as an alternative.
The implementation in QEMU is not complete and there is a better replacement, virtio-fs, which is already implemented in libvirt as well.