Re: How to realize multi-threading or multi-process for QOM

[Alex Bennée]

Hiroko Shimizu <hiroko07168@gmail.com> writes:

> Hello,
>
> I would like QOM to do QOM's process independently.

I'm not sure what this means. QOM is the QEMU Object Model which is
basically our plain C version of objects. Are you in fact referring to
QMP which is the serialised management interface used by VMMs?

> I make a memory device as QOM which execute some process according to the 
> command specified by firmware, so MemoryRegionOps
> functions are called back when reading and writing.
> I would like to make the process of the MemoryRegionOps functions
> independent because the real memory device do.
>
> I think multi-threading or multi-process is useful for this problem. But, how 
> do you realize multi-threadning? I use option "-accel
> tcg,thread=multi" for executing QEMU, but it didn't work.

That option is for selecting MTTCG - which is using a host thread for
each simulated vCPU. It should be enabled automatically when the
host/guest combination allow for it. 

>
> Could you give me some information how to solve this issue?

https://qemu.readthedocs.io/en/latest/system/multi-process.html

As far as I know lsi53c895a is the only device that currently supports
running the emulation in a separate process. I'd start looking at that.

>
> Best regard, 
> Hiroko


-- 
Alex Bennée