Pius XII went to his grave being eulogized by no less than Golda Meir, later Prime Minister of Israel in the U.N. General Assembly.
It wasn't until 1963 that a play, written by the son of an SS man and part of a KGB agitprop campaign, started the "Pius XII didn't care about the Holocaust" lie.
I have no doubt that Pius XII was a nice man, but there are such things as sins of omission; and Pius XII didn’t do anything about the Holocaust.
You can read about it at http://www.newadvent.org/cathen/11251b.htm
You will not like reading about Pius XII at
http://www.jewishvirtuallibrary.org/jsource/anti-semitism/pius.html
But, there it is ...