Re: Emulating multi core processor (ARM cortex M7) on QEMU

[Philippe Mathieu-Daudé]

Hello,

On 26/2/24 11:58, ankita suman wrote:
> Hello,
>
> I am trying to emulate multi core processor (dual core for now) on QEMU. 
> The processor I am targeting is cortex m7. I tried by running multiple 
> instances of QEMU to emulate multi cores, and use shared memory for 
> communication, but since I am working on a bare metal environment, I 
> don't have the options of libraries for synchronization.

Have a look at the 'fby35' machine in hw/arm/fby35.c, it uses
a pair of Aspeed ast1030 and ast2600 ARM cores.

> Another approach I tried was using inter VM shared memory(ivshmem). But 
> I am facing the same problem. I am able to write and read from the 
> ivshmem device from two different QEMU instances, but it is not working 
> for ARM.

Cc'ing Gustavo who worked on something similar and posted ivshmem
patches:
https://lore.kernel.org/qemu-devel/20240222222218.2261956-1-gustavo.romero@linaro.org/

> can someone please guide me on how to proceed and what is the best 
> approach? If there are library support in QEMU for multi core emulation, 
> kindly let me know, that would be helpful as well.

Regards,

Phil.