Ionized reflection has often been considered as the explanation for the
unusual Fe K variability observed in MCG--6-30-15. In this paper, we test this
model using a 325 ks observation of MCG--6-30-15 by XMM-Newton and BeppoSAX.
The data are fit between 2.5 and 80 keV with the constant density models of
Ross & Fabian. The best fit ionized reflection model requires the Fe K line to
be split into two reprocessing events: one from the inner disc to build up the
red wing, and the other from the outer accretion disc to fit the blue horn. The
implied geometry is a disc which becomes strongly warped or flared at large
radii. A good fit was obtained with a solar abundance of iron and a reflection
fraction (R) of unity for the inner reflector. The combination of the two
reflection spectra can appear to have R>2 as required by the BeppoSAX data. The
inner reflector has an ionization parameter \log \xi =3.8, but the outer one is
neutral with an inner radius ~70 gravitational radii (r_g), corresponding to a
light crossing time of about an hour for a 10^7 Msun black hole. Applying this
model to time-resolved spectra shows that the inner reflector becomes more
ionized as the source brightens. This reduces the strength of the red wing at
high flux states. The X-ray source is constrained to arise from a narrow
annulus at ~5 r_g, with only 6 per cent of the 2-10 keV flux due to the outer
reprocessor. This amount of localized energy generation is extremely difficult
to produce without resorting to other energy sources such as the black hole
spin. In fact, all the Fe K models fit to XMM-Newton spectra of MCG--6-30-15
require a large increase in energy production at the inner edge of the
accretion disc.Comment: 11 pages, 7 figuers, MNRAS in pres