what is the name of this attack to the king's indian? have you seen lt?


I don't know if this idea has an opening name per se, but h3 or h4 are common ideas to White in King's Indian positions. I often play the h4 lines as White myself against the King's Indian Defense. I usually won't go for h4 this early though.
IIRC King's Indian players prefer c5 against the Samisch setup to e5; you've only considered black's response of e5.

IIRC King's Indian players prefer c5 against the Samisch setup to e5; you've only considered black's response of e5.
No, not quite. I play the Saemisch variation a lot and am more than willing to play against the c5 lines too. I just put some moves onto the board to display the ideas White often goes for and why h4 is not unjustified. I did not intend to explain the theory I know; I wanted to simply address the op here. The op is rated about 1900 and probably knows a lot of theory; they were just asking if this h4 idea had an opening name. (I don't think it does, but h4 is a common motif in many of these lines and alternatively an early h3 is also common while subtly less aggressive)

I don't know if there is a name.
I think Simon Williams was the first GM advocating it, thus we could call it the Williams system (attack).
Personnally, against this kind of set up for white which neglects development, i switch to Benko mode.
For example :
In these structures, I don't think white's attck is dangerous, while black has quick counterplay.
Some nice examples :
Jobava has 3 games as white in databases, against Radjabov, Atalik, and a 2400. Scoring 3 points!
Each game, black played the Benko style and Jobava just took the pawns and won, but not convincing to me...
Rapport also has a crushing score (2.5/3) as white.
But they are (almost) the only one as white having good results...
Here the Jobava-Radjabov game :
Black could also play in Benoni fashion, like this game :
Once again, white was in trouble because black played active in centre.

Thanks a lot poucin, very helpful. Yes I watched Simon's Killer DVDs on 1.d4, from those DVDs exactly was where I got the idea of playing this system with the white pieces, although I have been successful with it in online rapid games, now I see it would not be so easy in long OTB games, specially if black plays this Benko set up. I will check it deeper with my chess engine anyways. Thanks again!