The flag can be enabled using the new 'mtu' option:
bhyve -s X:Y:Z,virtio-net,[tapN|valeX:N],mtu=9000
Reported by: vmaffione, jhb
Approved by: vmaffione (mentor)
Differential Revision: https://reviews.freebsd.org/D23971
Both virtio_net and e82545 network frontends have code to validate and
generate MAC addresses. These functionalities are replicated in the two
files, so we move them in a separate compilation unit.
Reviewed by: rgrimes, bryanv, imp, kevans
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20626