  We construct a holographic map between asymptotically AdS_5 x S^5 solutions
of 10d supergravity and vacuum expectation values of gauge invariant operators
of the dual QFT. The ingredients that enter in the construction are (i) gauge
invariant variables so that the KK reduction is independent of any choice of
gauge fixing; (ii) the non-linear KK reduction map from 10 to 5 dimensions
(constructed perturbatively in the number of fields); (iii) application of
holographic renormalization. A non-trivial role in the last step is played by
extremal couplings. This map allows one to reliably compute vevs of operators
dual to any KK fields. As an application we consider a Coulomb branch solution
and compute the first two non-trivial vevs, involving operators of dimension 2
and 4, and reproduce the field theory result, in agreement with
non-renormalization theorems. This constitutes the first quantitative test of
the gravity/gauge theory duality away from the conformal point involving a vev
of an operator dual to a KK field (which is not one of the gauged supergravity
fields).
