Frederic Konrad <fred.kon...@greensocs.com> writes: > 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?
Does this imply deferring the work? Surely if we don't flush when instructed things could break down very quickly? > > Thanks, > Fred -- Alex Bennée
