I have to add oil at every oil change as well- six quarts. It's how I complete the oil change.
Seriously, though- How many miles are on this rig? How low is the oil? What kind of oil do you use? How many miles do you go between changes?
First off, do you know the difference between smoke and steam? Pretty much all engines steam off condensation when they're first started. More so when the weather is cooler.
If it is smoke, like burning oil kind of smoke, then it's likely worn valve seals.
On the other hand:
These things normally consume a little oil, mostly due to the AFM activating and deactivating. The pressure release valve for the AFM is a pop-off style, located in the oil pan. When AFM activates, the pressurized oil is directed away from the lifters and into the oil pan, through that valve. When the valve pops open (at around 55ish psi), the oil sprays from it. Most of the oil just goes into the sump, but, since it's a spray (mist), some gets carried up into the PCV stream, into the driver's side cylinder head. The airflow of the PCV system carries the oily mist through the port in the rocker cover, through the PCV hose, and into the top of the intake manifold. Most of it is sucked into the cylinders (mostly the rearmost cylinders) and burned off, as the PCV is designed to do. But there is liquid oil that settles and collects as a puddle in the back of the manifold.
To combat the oil consumption from this, GM came up with a shield to go over the pressure release valve so the oil doesn't spray into a mist. They also redesigned the baffle in the driver's side rocker cover to relocate the PCV intake hole away from the direct stream of oil squirting/splashing up from the pushrod and rocker.
Yours, being a 2011, should have the updated rocker cover. I think the shield was only installed if consumption was a problem.
Since the PCV system moves so much oil (inherent to the LS engine, regardless if AFM-equipped or not), it is widely known that they should have a catch can installed in the PCV tract to reduce the amount of oil entering the intake manifold and combustion chambers. In more extreme cases, the rearmost cylinders get so much oil in them that the combustion chambers build up carbon deposits. These deposits also build up on the rings and they can stick. This accelerates the wear of the rings and cylinder walls, leading to lost compression (weaker cylinder(s)) and more blow-by. The blow-by leads to more oil vapor in the crankcase, which increases the amount of oil in the PCV system... and the vicious cycle continues and feeds itself.
Running cheap oil for too long between changes contributes to oil loss. Cheaper oil, particularly conventional oil, begins to break down and burn off if ran for too long.
My suggestions:
1) Use quality oil, preferably synthetic
2) Don't base your changes by the Oil Life Monitor, stick to a more regular schedule (I like 5K intervals)
3) Disable AFM either with a plug-in module or a custom tune
4) Install a catch can
