Data processing accelerator having a local time unit to generate timestamps
According to one embodiment, a DP accelerator includes one or more execution units (EUs) configured to perform data processing operations in response to an instruction received from a host system coupled over a bus. The DP accelerator includes a security unit (SU) configured to establish and maintain a secure channel with the host system to exchange commands and data associated with the data processing operations. The DP accelerator includes a time unit (TU) coupled to the security unit to provide timestamp services to the security unit, where the time unit includes a clock generator to generate clock signals locally without having to derive the clock signals from an external source. The TU includes a timestamp generator coupled to the clock generator to generate a timestamp based on the clock signals, and a power supply to provide power to the clock generator and the timestamp generator.
1. A data processing (DP) accelerator, comprising:
one or more execution units (EUs) configured to perform data processing operations in response to an instruction received from a host system coupled over a bus;
a security unit (SU) on the DP accelerator configured to establish and maintain a secure channel with the host system to exchange commands and data associated with the data processing operations; and
a time unit (TU) on the DP accelerator coupled to the security unit to provide timestamp services to the security unit, wherein the time unit comprises:
a clock generator to generate clock signals locally on the DP accelerator without deriving the clock signals from clock source external to the DP accelerator,
a timestamp generator coupled to the clock generator to generate a timestamp based on the clock signals, and
a power supply on the DP accelerator to provide power to the clock generator and the timestamp generator such that the power supply cannot be controlled external to the DP accelerator;
wherein the time unit is configured to generate a timestamp for a session key for the secure channel with the host system, and a count of time until the session key expires is maintained by the time unit on the DP accelerator.
2. The DP accelerator of claim 1 , wherein the time unit further comprises:
a counter coupled to the clock generator to count a count value based on the clock signals generated from the clock generator; and
a persistent storage to store the count value, wherein the count value is utilized by the timestamp generator to generate the timestamp.
3. The DP accelerator of claim 2 , wherein the counter is configured to increment the count value in response to each of the clock signals, and wherein the persistent storage comprises a 32-bit variable.
4. The DP accelerator of claim 1 , wherein the time unit further comprises a local oscillator coupled to the clock generator to provide precise pulse signals.
5. The DP accelerator of claim 1 , wherein the power supply comprises a battery to provide the power without having to draw power from power source external to the DP accelerator.
6. The DP accelerator of claim 1 , wherein the clock signals are generated without having to communicate with an external clock source.
7. The DP accelerator of claim 1 , wherein the time unit further comprises a clock calibrator configured to calibrate the clock generator.
8. The DP accelerator of claim 1 , wherein the timestamp is utilized by the security unit to time stamp the session key for encrypting the exchanged data between the DP accelerator and the host system.
9. The DP accelerator of claim 8 , wherein the timestamp is utilized to time stamp an information exchange for the DP accelerator, and the timestamp can be used to determine a freshness of the information exchange.
10. The DP accelerator of claim 1 , wherein the clock generator and the power supply cannot be controlled from a source external to the DP accelerator.
11. A data processing system, comprising:
a host system hosting one or more trusted execution environments (TEEs), each TEE hosting at least one application therein; and
one or more data processing (DP) accelerators coupled to the host system over a bus, wherein each of the DP accelerators comprises:
one or more execution units (EUs) configured to perform data processing operations in response to an instruction received from a host system coupled over a bus,
a security unit (SU) on the DP accelerator configured to establish and maintain a secure channel with the host system to exchange commands and data associated with the data processing operations, and
a time unit (TU) on the DP accelerator coupled to the security unit to provide timestamp services to the security unit, wherein the time unit comprises:
a clock generator to generate clock signals locally on the DP accelerator without deriving the clock signals from clock source external to the DP accelerator,
a timestamp generator coupled to the clock generator to generate a timestamp based on the clock signals, and
a power supply on the DP accelerator to provide power to the clock generator and the timestamp generator such that the power supply cannot be controlled external to the DP accelerator,
wherein the time unit is configured to generate a timestamp for a session key for the secure channel with the host system, and a count of time until the session key expires is maintained by the time unit on the DP accelerator.
12. The system of claim 11 , wherein the time unit further comprises:
a counter coupled to the clock generator to count a count value based on the clock signals generated from the clock generator; and
a persistent storage to store the count value, wherein the count value is utilized by the timestamp generator to generate the timestamp.
13. The system of claim 12 , wherein the counter is configured to increment the count value in response to each of the clock signals, and wherein the persistent storage comprises a 32-bit variable.
14. The system of claim 11 , wherein the time unit further comprises a local oscillator coupled to the clock generator to provide precise pulse signals.
15. The system of claim 11 , wherein the power supply comprises a battery to provide the power without having to draw power from a source external to the DP accelerator.
16. The system of claim 11 , wherein the clock signals are generated without having to communicate with an external clock source.
17. The system of claim 11 , wherein the time unit further comprises a clock calibrator configured to calibrate the clock generator.
18. The system of claim 11 , wherein the timestamp is utilized by the security unit to time stamp the session key for encrypting the exchanged data between the DP accelerator and the host system.
19. The system of claim 18 , wherein the timestamp is utilized to time stamp an information exchange for the DP accelerator, and the timestamp can be used to determine a freshness of the information exchange.
20. The system of claim 11 , wherein the clock generator and the power supply cannot be controlled from a source external to the DP accelerator.