Re: [PATCH net-next v4 0/7] Add RPMSG Ethernet Driver

[MD Danish Anwar <danishanwar@ti.com>]

Hi Andrew,

On 11/09/25 9:34 pm, Andrew Davis wrote:
> On 9/11/25 6:36 AM, MD Danish Anwar wrote:
>> This patch series introduces the RPMSG Ethernet driver, which provides a
>> virtual Ethernet interface for communication between a host processor and
>> a remote processor using the RPMSG framework. The driver enables
>> Ethernet-like packet transmission and reception over shared memory,
>> facilitating inter-core communication in systems with heterogeneous
>> processors.
>>
> 
> This is neat and all but I have to ask: why? What does this provide
> that couldn't be done with normal RPMSG messages? Or from a userspace
> TAP/TUN driver on top of RPMSG?
> 

This is different from RPMSG because here I am not using RPMSG to do the
actual TX / RX. RPMSG is only used to share information (tx / rx
offsets, buffer size, etc) between driver and firmware. The TX / RX
happens in the shared memory. This implementation uses a shared memory
circular buffer with head/tail pointers for efficient data passing
without copies between cores.

> This also feels like some odd layering, as RPMSG sits on virtio, and
> we have virtio-net, couldn't we have a firmware just expose that (or
> would the firmware be vhost-net..)?
> 

PMSG sits on virtio, and we do have virtio-net but I am not trying to do
ethernet communication over RPMSG. RPMSG is only used to exchange
information between cores regarding the shared memory where the actual
ethernet communication happens.

> Andrew
> 


-- 
Thanks and Regards,
Danish