On Wed, 21 Jul 2021 08:02:42 +1000 Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote: Hi, > 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? > can we instead describe them in DT and/or ACPI ? I think part of the idea of SMCCC is that it does NOT need firmware advertisement, but can instead be discovered, through a safe interface. Cheers, Andre
