It is wonderful that you demonstrate your love and support in such a way that he is comfortable talking to you about such a deeply personal thing. You've received some great responses here! Like the others I applaud your relationship with your son. Take care and enjoy the great relationship you have with your lovely boy. If at some point other issues come up, such as anxiety around telling others when he is ready, or if he is experiencing bullying or harassment then you may need additional support. My view is that is all you have to do! And keep the lines of communication open. Allow him to talk and be open with you, which again you already seem to be doing.
I am not sure there is anything you need to do apart from helping him understand that he is normal, which you are already doing. So I think it is likely your son does know he is gay at 11. He says he always just understood that the depictions of heterosexual families and relationships that were everywhere were just not him, that he was different from that. My son says he always knew he was gay, although he didn’t always have a word for it. My now 18 year old son came out to us when he was about the same age as your son. It sounds like you have a great relationship with your son. I saw your post and I am hoping that I might be able to provide some help.