Hi everybody,
In multithread tlb_flush is broken as CPUA can flush an other CPUB and
CPUB can be
executing code, and fixing this can be quite hard:
* We need to exit the CPU which is flushed.
* Makes sure the CPU is stopped.
* Then we can flush tlb.
The big issues are:
* Two threads can be doing a flush at the same time.
* Something can restart the CPU during the flush.
A better idea I think is that instead of flushing tlb we can put a flag
in CPUState such
as flush_request and ask the cpu to exit.
Then later once the CPU is exited we can flush tlbs if flush_request is set.
It will ensure that the CPU won't execute code as it's associated thread
will be
flushing.
Can this work?
Thanks,
Fred
