However, if by "genociding Ukrainian people" you mean eradicating the population of Ukraine that considers itself distinct from Russia, Trump could conceivably stop the war by letting Russia hold onto territories it owns, while having the rest of Ukraine as a protectorate of various European powers that may eventually bring it into the EU.
This might result in a populatin exchange as Russian speakers get sent to the Russian-held parts of Ukraine and vice-versa. This would not be good but it would not be a genocide either. You can also look at the Indian partition for an example of how this could go horribly wrong.