IP Library Granted Patent US 12,547,784
Granted Patent B2
US 12,547,784 · App. 18/178,593 · Granted Feb 10, 2026

Systems and methods to represent functions in a PCIe multi-function field replaceable unit

Inventors: Viswanath Ponnuru (Bangalore, IN); Austin P. Bolen (Austin, TX); Chandrashekar Nelogal (Round Rock, TX)
Assignee: Dell Products, L.P.
G06F21/85G06F21/33
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Quick Facts
Patent No.
US 12,547,784
App. No.
18/178,593
Granted
Feb 10, 2026
Kind
B2
Abstract

Embodiments of systems and methods to determine all of the Functions that are associated with a multi-Function Peripheral Component Interconnect/Compute Express Link (PCIe/CXL) Field Replaceable Unit (FRU) for use in SPDM authentication of a PCIe/CXL FRU are disclosed. According to one embodiment, a multi-Function PCIe/CXL FRU includes multiple Functions that each are represented by a unique Device/Function path. A PCIe/CXL FRU includes computer-executable program instructions that cause it to receive a request from a Security Protocol and Data Model (SPDM) requester to obtain information about a plurality of Functions associated with the PCIe/CXL FRU, and respond to the request by sending a list of Device/Function paths to the SPDM requester. Each Device/Function path indicates the Function and the path to the Function associated with the PCIe/CXL FRU.

Claims (41)

1 . A function representation system comprising:

a multi-Function Peripheral Component Interconnect/Compute Express Link (PCIe/CXL) Field Replaceable Unit (FRU) comprising a plurality of Functions that each are represented by a unique Device/Function path, the plurality of Functions comprising at least one processor and at least one memory coupled to the at least one processor, the at least one memory having program instructions stored thereon that, upon execution by the at least one processor, cause the PCIe/CXL FRU to:

receive a request from a Security Protocol and Data Model (SPDM) requester to obtain information about a plurality of Functions associated with the PCIe/CXL FRU; and

respond to the request by sending a list of Device/Function paths to the SPDM requester, wherein each Device/Function path indicates the Function and the path to the Function associated with the PCIe/CXL FRU.

2 . The function representation system of claim 1 , wherein the request comprises an authentication request from the SPDM requester.

3 . The function representation system of claim 1 , wherein the instructions, upon execution, cause the first Function to:

respond to the request by sending a certificate chain of the first Function to the SPDM requester, wherein the list of Device/Function paths is included in an Extended Key Attribute field of a TCB layer 0 certificate.

4 . The function representation system of claim 3 , wherein the list of Device/Function paths comprises a hierarchy of evidence that ties the evidence for each Function eventually with the first Function.

5 . The function representation system of claim 1 , wherein the instructions, upon execution, cause the PCIe/CXL FRU to:

Receive the request after the first PCIe Function has been authenticated by the SPDM requester, wherein the request comprises a single Security Protocol and Data Model (SPDM)-based command.

6 . The function representation system of claim 5 , wherein the instructions, upon execution, cause the PCIe/CXL FRU to obtain the list of Device/Function paths associated with the PCIe/CXL FRU from a memory of the PCIe/CXL FRU.

7 . The function representation system of claim 5 , wherein the instructions, upon execution, cause the PCIe/CXL FRU to:

determine that the Device/Function path of a second Function has changed; and

generate an updated list of Device/Function paths based on the determination.

8 . The function representation system of claim 1 , wherein the SPDM requester comprises a Remote Access Controller (RAC).

9 . The function representation system of claim 1 , wherein the firmware of each of the Functions are implemented in different layers that are structured according to a Device Identifier Composition Engine (DICE) architecture.

10 . The function representation system of claim 1 , wherein the request comprises a Device/Function path of the Function whose certificate chain is requested, and wherein the instructions, upon execution, cause the PCIe/CXL FRU to:

respond to the request by providing the requested certificate chain along with a Device/Function path of a certificate chain that the requested Function's certificate chain is linked to, and the certificate number within the certificate chain that the requested Function's certificate chain is linked to.

11 . A function representation method comprising:

receiving, by a function of a multi-Function Peripheral Component Interconnect/Compute Express Link (PCIe/CXL) Field Replaceable Unit (FRU), a request from a Security Protocol and Data Model (SPDM) requester of the multi-Function PCIe/CXL FRU to obtain information about a plurality of Functions that each are represented by a unique Device/Function path; and

responding to the request by sending a list of Device/Function paths to the SPDM requester, wherein each Device/Function path indicates the Function and the path to the Function associated with the PCIe/CXL FRU.

12 . The function representation method of claim 11 , further comprising:

responding to the request by sending a certificate chain of the first Function to the SPDM requester, wherein the list of Device/Function paths is included in an Extended Key Attribute field of a TCB layer 0 certificate.

13 . The function representation method of claim 11 , further comprising:

receiving the request after the first PCIe Function has been authenticated by the SPDM requester, wherein the request comprises a single Security Protocol and Data Model (SPDM)-based command.

14 . The function representation method of claim 13 , further comprising obtaining the list of Device/Function paths associated with the PCIe/CXL FRU from a memory of the PCIe/CXL FRU.

15 . The function representation method of claim 13 , further comprising:

determining that the Device/Function path of a second Function has changed; and

generating an updated list of Device/Function paths based on the determination.

16 . The function representation method of claim 11 , further comprising implementing the firmware of each of the Functions in different layers that are structured according to a Device Identifier Composition Engine (DICE) architecture.

17 . The function representation method of claim 11 , further comprising:

responding to the request by providing the requested certificate chain along with a Device/Function path of a certificate chain that the requested Function's certificate chain is linked to, and the certificate number within the certificate chain that the requested Function's certificate chain is linked to.

18 . An Information Handling System (IHS) comprising:

a multi-Function Peripheral Component Interconnect/Compute Express Link (PCIe/CXL) Field Replaceable Unit (FRU) comprising:

a plurality of Functions that each are represented by a unique Device/Function path, the plurality of Functions comprising at least one processor and at least one memory coupled to the at least one processor, the at least one memory having program instructions stored thereon that, upon execution by the at least one processor, cause the PCIe/CXL FRU to:

receive a request from a Security Protocol and Data Model (SPDM) requester to obtain information about a plurality of Functions associated with the PCIe/CXL FRU; and

respond to the request by sending a list of Device/Function paths associated with the PCIe/CXL FRU to the SPDM requester, wherein each Device/Function path indicates the Function and the path to the Function associated with the PCIe/CXL FRU.

19 . The IHS of claim 18 , wherein the program instructions, upon execution, further cause the PCIe/CXL FRU to:

respond to the request by sending a certificate chain of the first Function to the SPDM requester, wherein the list of Device/Function paths is included in an Extended Key Attribute field of a TCB layer 0 certificate.

20 . The IHS of claim 18 , wherein the program instructions, upon execution, further cause the PCIe/CXL FRU to:

receive the request after the first PCIe Function has been authenticated by the SPDM requester, wherein the request comprises a single Security Protocol and Data Model (SPDM)-based command.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 6, 2023
From: PONNURU, VISWANATH; BOLEN, AUSTIN P.; NELOGAL, CHANDRASHEKAR
To: DELL PRODUCTS, L.P.
Reel/Frame 062886/0749 →
Continuity (1)
Related Publication 20240303380A1 · Sep 12, 2024
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