Re: [Qemu-devel] Multiple instances of Qemu on Windows multicore

[Paolo Bonzini]

On 11/02/2011 06:16 PM, malc wrote:
> (mm)Timers have a possibility of running on a thread of their own which
> might be schedulled on the CPU different from the thread that runs
> emulated code, unchaining TBs and can (and will) fail in this case.

This should not be a problem with dynticks+iothread (i.e. it should work 
or not work equally).  We now run just this basically when an alarm fires:

        t->expired = t->pending = 1;
        qemu_notify_event();

The rest is always done in the iothread.  The iothread will then 
suspend/resume the VCPU thread around the unchaining, so what matters is 
(in Unix parlance) signal-safety of the unchaining, not thread-safety.

Paolo