i'm not sure what the cannonical way to do this is but in plan9.ini i set mouseport=usb and then i have modified the mouse-setting part of /rc/bin/termrc to read like this
if(test -f /dev/mousectl && ~ $mouseport ps2 ps2intellimouse 0 1 2 usb){
if(~ $mouseport usb)
usbstart
if not
aux/mouse $mouseport
# parse vgasize into fields
vgasize=`{echo $vgasize}
if(! ~ $"monitor '' && ! ~ `{cat /dev/user} none)
aux/vga -l $vgasize
if(~ $accupoint 1)
pipefile -dr /bin/aux/accupoint /dev/mouse
}
