"For that you need arms, money and an economic lifeline. China provides Russia with, at least, components for arms, and civilian technology that can be used for military purposes. It definitely provides money."
To counter Western sanctions, and to shore up the Russian economy, Russia has been boosting trade with China, primarily in the energy sector. Expect oil, gas and energy pipelines to be on the agenda at the Putin-Xi talks.
But, once again, imagine you're Putin. One year ago you and Xi proclaimed that your partnership has "no limits". If that's really the case, might you expect China now to help you out in Ukraine, by supplying Russia with lethal aid and facilitating a military victory for Moscow? The US claims that China is considering doing just that. Beijing denies it.
As they say in Russia, "there's no harm wishing for something" - but it doesn't mean it's going to happen. If there's one thing the last year has shown it is that the "no-limits partnership" does have limits. Up to this point Beijing has apparently been reluctant to provide direct military assistance to Moscow, for fear of triggering secondary sanctions in the West against Chinese companies. As far as Beijing is concerned: sorry Russia… it's China first.