shared folder kvm whonix 11 works with fedora 21 host. The workaround :
install policycoreutils-gui , run it and set enforcing mode to permissive from enforcing , install users and groups , run it and go: users/your username/properties/groups/check the root and ok, then go: groups/your username/properties/group users/check the root and ok, then if not allready done the directions for sharing folder kvm on whonix documentation, do that , then evry time when boot in whonix guests must mount the folder if you want to use it, if set fstab for automount automaticaly , in guest booting will stop the booting and show a message by apparmor , you can pass that but guest will boot in emergency mode? i dont know if that is security risk so better don't edit fstab for automount the shared folder , except if you know that is not a security risk.
If thing that disable selinux is security risk , that is a way for sharing folder, if use usb for transfer files from guest that is again discuraged by whonix maintainers for security reasons, i dont know if take place for security ' that the usb drive\flash will luks encrypted