On Sun, 2023-11-05 at 13:35 +0000, Jason-JH Lin (林睿祥) wrote: > Hi CK, > > On Thu, 2023-10-26 at 02:26 +0000, CK Hu (胡俊光) wrote: > > Hi, Jason: > > > > On Mon, 2023-10-23 at 12:45 +0800, Jason-JH.Lin wrote: > > > Add cmdq_insert_backup_cookie to append some commands before EOC: > > > 1. Get GCE HW thread execute count from the GCE HW register. > > > 2. Add 1 to the execute count and then store into a shared > > > memory. > > > > I think when cmdq driver handler interrupt, it could simply call > > into > > TEE with an API to query status. The status not only the execute > > count, > > but also other message including error information. So it's not > > necessary to use such non-tricky way to get execute count. > > The reason why we use shared memory to record execute count here is: > 1. normal world can not access the register of secure GCE thread in > normal world. > 2. calling TEE invoke cmd in the irq handler would be expensive and > not > stable. I've tested that a single TEE invloke cmd to CMDQ PTA costs > 19~53 us. Maybe it would cost more during the scenario that needs > more > CPU loading. Add this to comment. > > > > > One more question. The command buffer is not secure. Does the GCE > > hardware execute this non-secure command buffer? > > > > GCE command buffer is generate in the normal world first. Then it > will > be copied to the shared memory and pass to the secure world. All the > instruction in command buffer will be verified in secure world then > they will be copied to the secure command buffer and executed by GCE > secure thread. I'll add this information to the cover letter at the > next version. > > Regards > Jason-JH.Lin > > > Regards, > > CK > >
