Here is the Chinese response to the Russian attack on Georgia. The Shanghai Cooperation Organization officially supported Russia's role in bringing stability to the region, but also came down sharply on maintaining the territorial integrity of the region. Meaning: No Separatism!
Beijing fully supports the notions of both sovereignty and territorial integrity. It has been fighting for decades to increase support for the norm of sovereignty over that of self-determination. Of course, it has a lot to lose from self-determination: about half of its land mass would probably leave. At the same time, no one doubts that the Chinese military COULD do the same things that the Russian military just did. Instead, though, China wants to build public support world-wide for its stands.
I think in the long run, the Chinese path will work out better than the Russian one.