On Mon, Aug 10, 2020 at 10:52:44PM +0800, Zhenyu Ye wrote:
> Before doing qmp actions, we need to lock the qemu_global_mutex,
> so the qmp actions should not take too long time.
> 
> Unfortunately, some qmp actions need to acquire aio context and
> this may take a long time.  The vm will soft lockup if this time
> is too long.
> 
> So add a timeout mechanism while doing qmp actions.

aio_context_acquire_timeout() is a workaround for code that blocks the
event loop. Ideally there should be no code that blocks the event loop.

Which cases have you found where the event loop is blocked?

I think they should be investigated and fixed (if possible) before
introducing an API like aio_context_acquire_timeout().

Stefan