Hi,
We consider updating the range of FF-A IDs for Secure Partitions running in SWd on top of Hafnium.
Bit 15 in FF-A IDs can serve to hint the world type into which the VM/SP resides. FF-A id bit 15 clear => id space [1 : 0x7fff] reserved for VMs on top of NWd Hafnium FF-A id bit 15 set => id space [0x8001 : 0xffff] reserved for SPs on top of SWd Hafnium
0 reserved to the Hypervisor itself. 0x8000 reserved for the TEE (or later for the SPMC).
One way to achieve this is to define a static value for the base of FF-A ids, see: https://review.trustedfirmware.org/c/hafnium/hafnium/+/5165/1/inc/vmapi/hf/t...
The intent is to set 0 for the NWd Hypervisor build and 0x8000 for the SWd SPMC build. 1/ This can be done through the SECURE_WORLD macro (although this macro is only available to src/arch/aarch64/* files) 2/ This can be passed as a platform parameter in the build flow (e.g. same way as max_vms)
There are others ways rather than using id ranges, e.g. setting the bit explicitly in FF-A IDs when doing the SPMC build.
Any thoughts?
Regards, Olivier.