On Wed, Jul 21, 2021 at 12:18:03AM +0100, Andre Przywara wrote: > On Wed, 21 Jul 2021 08:02:42 +1000 > Benjamin Herrenschmidt wrote: > > On Tue, 2021-07-20 at 17:16 +0100, Andre Przywara wrote: > > > Yes, a similar idea was already brought up before. I think there is even > > > the potential for something like an artificial SMCCC "bus", where those > > > services presentable as devices could be auto-detected (by checking > > > known function IDs), the respective drivers would then probe > > > automatically? > > Sounds like a boot time killer... > How so? To be clear, at the moment there is basically just the TRNG > service we would probe for, maybe FF-A, then adding as we go. But in > any case it would be just a handful, and querying is very quick > (SMC/HVC, then just a switch/case on the other side, and ERET). > Is there any particular scenario you are concerned about? Quick > starting guests? It's also worth pointing out that we're already doing the enumeration part, making things a bus would just be about reorganising the code that checks if services are present to a central place so it looks more Linux style. If anything I'd guess that if we get to the point where things are slow enough to worry about having that code in one central place would make doing something about it easier (eg, adding a "list all services" service or firmware binding).