Hi, 
    I don't know whether this is the right place to discuss,  sorry for bothering.
 
    OP-TEE OS has already support virtualization, but modification to the hypervisor is also necessary. But the proprietary Hypervisors are close sourced and some TEE OSes are alos close-sourced, such as QSEE from QualComm. So maybe virtio-tee is an alternative solution for the Guest VM to access the OP-TEE.

In detail, CA from Guest VM --> libteec.so (GuestVM) --> tee driver(GuestVM) -->optee_do_call_with_arg() --> invoke_fn()--> virtio-tee driver --> virtio-tee device(HostVM) --> libteec.so (HostVM) --> tee driver(HostVM) -->optee_do_call_with_arg() -->invoke_fn() --> TEEOS.

I think the virtio-tee device must transfer the RPC to the virtio-tee driver in the GuestVM, then to the tee-supplicant in the GuestVM, in order to load the TAs in the GuestVM.

In the HostVM, the tee-supplicant accesses the tee-driver through /dev/teepriv0, and the virtio-tee device accesses the tee-driver through /dev/teepriv1, So I wonder how the HostVM tee driver can dispatch the RPC from OP-TEE to the correct receiver , tee-supplicant or the virtio-tee device?

Best Regards,
Li Cheng