Re: [Qemu-devel] QEMU & multithreaded device emulation

[Emmanuel Blot]

(I forgot to CC: the list)

On Wed, Jan 23, 2013 at 2:16 PM, Emmanuel Blot <address@hidden> wrote:
>> Today you cannot use cpu_physical_memory_*() from a thread without
>> holding the QEMU global mutex.
> Ok. I have not looked at this part, which API handles this global mutex?
>
>> Have you tried taking the mutex temporarily just for map/unmap and then
>> doing the copy or I/O outside the mutex?
> Not yet. I've written a prototype (which works, with a single device
> thread for the datastream pipe + the existing QEMU threads) when I
> realized that the map/unmap may not be protected. For now I have not
> observed memory corruption, but I got lucky :-)
>
>> qemu_bh_schedule() should be thread-safe (but please double-check).
> Ok.
>
> Thanks for your answers,
> Manu