After booting Windows 10 guest, bhyve logs "atkbd data buffer full" to console and no key strokes are received by the guest.
Behaviour present in bhyve in base of 11.0-Release, as well as the most recent SVN revision checked out bhyve 307779.
only reference found: http://freebsd.1045724.x6.nabble.com/bhyve-graphics-support-td6101646.html
behaviour also persistent between Host reboots.
Windows requires the hostdev device to be in slot 1 and lpc device in slot 31.
I don't believe there to be a bug in bhyve here. If using the suggested slots does not resolve this issue, feel free to reopen.