China is massively vulnerable, it relies on the middle east for the majority of its oil supply and its economy runs on trade with the west. It doesn't have much of a long range navy, so it can't keep sea lanes open. It's a big threat locally, though, and if Putler has any sense, he'd keep what ever few working nukes he has pointing firmly east because I bet all that oil and gas that can't be blockaded by other navies looks good to Xi.
Hence China opening more coal fired power stations and getting major wobbles about the merry go round of Australian coal being interrupted. But you can't realistically run trucks or cars on coal or make plastics out of it.
China's economy is heavily based on exports of cheap and cheerful consumer products to the West. The West's current attitude to human rights violations with the Uighurs and Hong Kong (ie, not very much, eg a Strongly Worded Statement from Truss) shows tacit support for China. Basically we are more concerned about a continuing supply of barbecue products and Christmas tree lights than genocide. So for the time being China is 'on our side' and 'not on Putin's'. They know which side their bread is buttered. So do we.
Russia exports nothing of any value apart from gas and minerals and countries that are dependent are frantically trying to convert to other sources. So what is Xi going to do? Continue with his Belt and Road expansion and keep the West pacified and happy with a continued supply of electronic gadgets and gardening tools in exchange for not rocking the oil tankers that he relies on? Or get all Comradely with Putin and start WW3 for absolutely no reason at all? This is 'not good for business.'
China has long standing ambitions for Taiwan and is nibbling away at the Spratlys and other trivial gains, as much to annoy the West as anything else. Britain did much the same planting the Union Flag in anything that didn't actually disappear beneath the waves 150 years ago, principally to piss off the Germans. But these things will wait. China has all the time in the world and is doubtless taking VERY careful note of the current Demonstration Army activities in Ukraine and the Black Sea to see how their own capabilities need to be improved. China will wait though....
So what's this got to do with Ukraine? Basically Xi is no friend of Putin's because it is in China's interest to stay chummy with the West and Russia offers nothing that China wants this year or next or the year after. Russia is in a very short term disaster and is in trouble. Putin is desperate for high end electronics and other gadgetry from China for missiles and maybe some 152mm might slip over the border, but this only serves to make Putin more reliant on Xi. Having Putin as his bitch is exactly what Xi wants. Maybe there are some minor territorial easements along the shared border that Xi might find useful to have in exchange and will forget to give back.
Sooner or later Russia is going to lose this war and be reduced to the global status of a piss stained tramp dossing in a shop doorway. The West is now far too heavily invested to let Putin win. Putin will die one day, maybe sooner rather than later. Once Russia has nothing left apart from natural resources, then China will show it's hand and make Russia an offer it can't refuse.
So in the short(ish) term China is very happy to watch Russia reduce itself militarily and economically in Ukraine to tramp status in a war it knows the West can't let Russia win and meanwhile the powers squabble among themselves creating a comfortably disunited front. In the longer term China strong arms a very favourable trade deal with Russia, Russia becomes a client state selling its mineral resources to China at give away rates, China uses that to economically strong arm the rest of the world in the next ten years, all without firing a shot. What's not to like?