[PATCH] RISC-V: KVM: Fix TOCTOU race in SBI system suspend handler

[Jiakai Xu]

> But... before we get too carried away. Unless I'm missing something, this
> race really looks too theoretical to justify any change at all. Do you
> have a test case in mind that could force it?

Unfortunately, I don't have a reproducer or test case that can reliably
trigger this race. 

But as we saw earlier, this is a real bug, and we can tell that just by 
analyzing the code.

The real environment is complex and unpredictable, and such races are 
possible. Wouldn't it be nice if we found it and fixed it now?

Regards,
Jiakai