  X-ray binaries are known to exhibit different spectral states which are often
associated with different black hole accretion modes. The exact geometry and
properties of these accretion modes is still uncertain. Recent IXPE
measurements of linear polarization of X-ray emission in canonical X-ray binary
system Cygnus X-1 allow us to test models for the hard spectral state of
accretion in a unique way. We show that general relativistic radiative
magnetohydrodynamic (GRRMHD) simulations of accreting stellar black hole in a
hard X-ray state may be consistent with the new observational information. In
the presented framework, where first-principle models have limited number of
free parameters, the polarimetric X-ray observations put constraints on the
viewing angle of the inner hot accretion flow.
