On Mon, 2022-04-18 at 22:28 -0700, Sathyanarayanan Kuppuswamy wrote: > > On 4/18/22 9:40 PM, Kai Huang wrote: > > > Please check the latest 1.0 specification (updated on Feb 2022). It has > > > details about R13 register. > > Thanks. So it seems GHCI 1.0 has also been updated and it is consistent with > > GHCI 1.5 now. In this case, why do we still assume 8K shared memory? Are you > > going to update the driver? > > > > Since the GetQuote spec only requires memory in 4K alignment, we just > went with 8k constant allocation. Since existing users does not > require more than 8k, it works. But I agree that this needs to be > changed. Quote format can be vendor specific, so there's no guarantee 3rd party won't have a Quote larger than 8k. > > In next version, I will change the driver to choose the allocation size > based on user space request. Since this change would require us to do > the memory allocation in IOCTL routine (instead of init code), it will > make it slower. But I think this is negligible compared to time it takes > for Quote request. So it should be fine. > > > Yes attestation request should never be something that is very frequent, thus should never be in a performance critical path.
