Mahrez struck from the spot as City won 2-1 at Borussia Dortmund and progress from the quarterfinals 4-2 on aggregate.
City now face PSG in the semis and Mahrez said, "It is very good for me. It's special, because I'm from Paris. I was born in Paris and I grew up there. I'm happy to play against this team.
"It will be a very big game. We also have a lot of appointments before, with the FA Cup semi-final (against Chelsea on April 17) and the English League Cup final (on the 25th against Tottenham).
"We will have time afterwards to think about this match and concentrate on it."