Hi Viresh,

I'll try to respond to your first question: indirect messages require FF-A notifications, and Trusty does not support those either.

The problem isn't Trusty specifically, but the layers between it and Linux: the hypervisor and SPMC.

To be as specific as I can: Hafnium supports notifications, but others don't.

For now, we'll need to work around this in virtio-msg-ffa with direct messages and polling.