  We determine the holonomy of generalized Killing spinor covariant derivatives
of the form $D= \nabla + \Omega$ on pseudo-Riemannian reductive homogeneous
spaces in a purely algebraic and algorithmic way, where $\Omega : TM
\rightarrow \Lambda^*(TM)$ is a left-invariant homomorphism. This is
essentially an application of the theory of invariant principal bundle
connections defined over homogeneous principal bundles. Moreover, the algorithm
allows a computation of the associated Killing superalgebra in certain cases.
The procedure is demonstrated by determining the supersymmetries of certain
homogeneous M2 duals, which arise in M-theory.
