VMMCI_F_TIMESYNC
vsc->sc_driver_features = VMMCI_F_TIMESYNC | VMMCI_F_ACK |
if (virtio_has_feature(vsc, VMMCI_F_TIMESYNC)) {
VMMCI_F_TIMESYNC | VMMCI_F_ACK | VMMCI_F_SYNCRTC);