  We review the main observational and theoretical facts about acceleration of
Galactic cosmic rays in supernova remnants, discussing the arguments in favor
and against a connection between cosmic rays and supernova remnants, the
so-called supernova remnant paradigm for the origin of Galactic cosmic rays.
Recent developments in the modeling of the mechanism of diffusive shock
acceleration are discussed, with emphasis on the role of 1) magnetic field
amplification, 2) acceleration of nuclei heavier than hydrogen, 3) presence of
neutrals in the circumstellar environment. The status of the supernova-cosmic
ray connection in the time of Fermi-LAT and Cherenkov telescopes is also
discussed.
