He is right down where he was buried, waiting on the resurrection..
Acts 2:29
Men and brethren, let me freely speak unto you of the patriarch David, that he is both dead and buried, and his sepulchre is with us unto this day.
His body is down where it was buried, but His soul and spirit are now in heaven. His soul was in Abrahams Bososm until Jesus ascended and then He was taken to heaven.
At the first resurrection of REv. 20 Davids body will join His soul and spirit and be whole again.
As Paul said:
2 Corinthians 5
King James Version
5 For we know that if our earthly house of this tabernacle were dissolved, we have a building of God, an house not made with hands, eternal in the heavens.
2 For in this we groan, earnestly desiring to be clothed upon with our house which is from heaven:
3 If so be that being clothed we shall not be found naked.
4 For we that are in this tabernacle do groan, being burdened: not for that we would be unclothed, but clothed upon, that mortality might be swallowed up of life.
5 Now he that hath wrought us for the selfsame thing is God, who also hath given unto us the earnest of the Spirit.
6 Therefore we are always confident, knowing that, whilst we are at home in the body, we are absent from the Lord:
7 (For we walk by faith, not by sight:)
8 We are confident, I say, and willing rather to be absent from the body, and to be present with the Lord.
We see that a person is more than a body, for Paul says when this earthly body dissolves we have a heavenly one and that to be absent from teh body is to be present with the Lord.