Re: [PATCH v7 6/6] xen/arm: ffa: Enable VM to VM without firmware

[Julien Grall <julien@xxxxxxx>]

Hi Bertrand,

On 17/07/2025 13:11, Bertrand Marquis wrote:
> When VM to VM support is activated and there is no suitable FF-A support
> in the firmware, enable FF-A support for VMs to allow using it for VM to
> VM communications.
> If there is OP-TEE running in the secure world and using the non FF-A
> communication system, having CONFIG_FFA_VM_TO_VM could be non functional
> (if optee is probed first) or OP-TEE could be non functional (if FF-A is
> probed first) so it is not recommended to activate the configuration
> option for such systems.
>
> To make buffer full notification work between VMs when there is no
> firmware, rework the notification handling and modify the global flag to
> only be used as check for firmware notification support instead.
>
> Also split probe function into one for firmware and one for vm to vm to
> make the implementation clearer.
>
> Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
> Reviewed-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall