Labiovelars

I wonder somewhat about the status of the labiovelars.

Was there really in IE an opposition between the labiovelars kw, gw
and ghw and the sequenses ku gu and ghu (with ayllabic u)


And if we go further to Latin, was this opposition lost, so that the
labiovelars had merged with k(q) + asyllabic u and g + asyllabic u.

If we go even further to Italian, this language still has qu, gu and
su, with asyllabic u prononced more or less simultanously with the
stop or silibant, but there is no asyllabic u elsewere. So it seems
that Italian has restored the labiovelars as phonemes, or is the u in
these combinations to be regarded as allophonems of v?