There's always some sort of peace deal available to any participant in a war: surrendering to your opponent's demands. War happens when those demands are not acceptable. Roughly speaking the difference between Ukraine's and Russia's demands is that Russia wants Ukraine to remain isolated from the west and militarily weak (which would make it easy for them to just go for it again), and Ukraine wants to align as tightly with the west as necessary to ensure Russia doesn't invade again, or failing that build up a credible enough deterrence themselves to achieve the same result.