How I managed to use BlueTooth audio with ThinkPad X220:

Enable BlueTooth support:

 kldload acpi_ibm ; echo 'acpi_ibm_load="YES"' >> /boot/loader.conf
 sysctl dev.acpi_ibm.0.bluetooth=1 ; echo dev.acpi_ibm.0.bluetooth=1 >> /etc/sysctl.conf

Ensure kernel module ng_ubt is loaded, though it should be loaded automatically by devd:
```
 kldload ng_ubt
```

Ensure bthidd service is enabled and started:

 sysrc bthidd_enable=yes ; service bthidd start

Ensure hcsecd service is enabled and started:

 sysrc hcsecd_enable=yes ; service hcsecd start

Put device in pairing mode and pair with FreeBSD. Can be done manually using hccontrol or using bluetooth-config script from Phabricator review
```
 bluetooth-config
```

Ensure that the connection exists by running hccontrol:

 hccontrol -n ubt0hci create_connection BT_ADDR_OF_DEVICE

Verify connection using:

 hccontrol -n ubt0hci read_connection_list

Install virtual_oss port:
```
 pkg install virtual_oss
```
Start virtual_oss:
```
 virtual_oss -C 2 -c 2 -r 48000 -b 16 -s 1024 -R /dev/null -P /dev/bluetooth/BT_ADDR_OF_DEVICE -d dsp
```
If after src r295440, add -T /dev/sndstat before the -d to enable the device to show up in /dev/sndstat. If you want to use the virtual_oss_ctl package to control the virtual_oss device via GUI, add -t vdsp.ctl to the end. If you have trouble, try changing 48000 to 44100.
Play audio via vlc or other app