  In the past few years, gamma-ray astronomy has entered a golden age. At TeV
energies, only a handful of sources were known a decade ago, but the current
generation of ground-based imaging atmospheric Cherenkov telescopes has
increased this number to more than one hundred. At GeV energies, the Fermi
Gamma-ray Space Telescope has increased the number of known sources by nearly
an order of magnitude in its first 2 years of operation. The recent detection
and unprecedented morphological studies of gamma-ray emission from shell-type
supernova remnants is of great interest, as these analyses are directly linked
to the long standing issue of the origin of the cosmic-rays. However, these
detections still do not constitute a conclusive proof that supernova remnants
accelerate the bulk of Galactic cosmic-rays, mainly due to the difficulty of
disentangling the hadronic and leptonic contributions to the observed gamma-ray
emission. In this talk, I will review the most relevant cosmic ray related
results of gamma ray astronomy concerning supernova remnants.
