From radio and higher-frequency observations, more than 300 SNRs have been discovered in the Milky Way, of which 220 fall into the H.E.S.S. Galactic Plane Survey. However only 50 SNRs are coincident with a H.E.S.S source and in 8 cases the VHE emissi
on is firmly associated with the SNR. The H.E.S.S. dataset includes now more than 8 years of observations and it is of great interest to extract VHE flux upper limits from undetected SNRs. These new measurements can then be used to test the standard paradigm of the SNRs as the origin of Galactic cosmic rays. In this contribution, the H.E.S.S. results on the population of SNRs and the subsequent constraints on the cosmic-ray acceleration efficiency in these sources will be presented.
