Re: Modification to single Threaded Multi-Core emulation in TCG

[Alex Bennée]

Arnabjyoti Kalita <akalita@cs.stonybrook.edu> writes:

> Hello all,
>
> I have a requirement to use the single-threaded implementation of
> multi-core emulation in TCG. This schedules the multiple cores in a
> round robin fashion from what I understand, at the end of a set timer
> interval.

--accel tcg,thread=single will force the round robin scheduling you need.

> I want to make a modification to this approach. I would like to
> schedule the vCPUs in a round-robin fashion but at the end of every
> Translation Block (TB)'s execution.  So, instead of having a timer to
> switch the vCPU, I would like to forcefully switch the vCPU when a
> translation block has been executed.

as a gross hack you can run with -d nochain and then ensure cpu_tb_exec
does the equivalent of rr_kick_next_cpu after you execute the block.

However before you go down this route I do have to ask why? What is it
you are trying to achieve with this running mode?

> What would be the best way to implement this approach? Do I need to
> raise an interrupt at the end of the execution of every TB ? Where in
> code should I start making changes ? I do not want the functionality
> of the original TCG execution driver to change.
>
> Best Regards,
> Arnabjyoti Kalita


-- 
Alex Bennée