[Cherry-Pick] UefiCpuPkg: Add PcdCpuSmmApSyncTimeout2 PCD

[apop5]

Description

Cherry-Picking PCD definition from edk2. This does not change the basecore functionality to consume this pcd.

Provide the capability for platform to specifies the 2nd timeout value in microseconds for the BSP/AP in SMM to wait for one another to enter SMM.

The added interface can enhance the flexibility of timeout configuration. In some cases, certain processors may not be able to enter SMI, and prolonged waiting could lead to kernel soft/hard lockup. We have now defined two timeouts. The first timeout can be set to a smaller value to reduce the waiting period. Processors that are unable to enter SMI will be woken up through SMIIPL to enter SMI, followed by a second waiting period. The second timeout can be set to a larger value to prevent delays in processors entering SMI case due to the long instruction execution.

Cc: Ray Ni ray.ni@intel.com Cc: Rahul Kumar rahul1.kumar@intel.com Cc: Gerd Hoffmann kraxel@redhat.com

• [ ] Impacts functionality?
  • Functionality - Does the change ultimately impact how firmware functions?
  • Examples: Add a new library, publish a new PPI, update an algorithm, ...
• [ ] Impacts security?
  • Security - Does the change have a direct security impact on an application, flow, or firmware?
  • Examples: Crypto algorithm change, buffer overflow fix, parameter validation improvement, ...
• [ ] Breaking change?
  • Breaking change - Will anyone consuming this change experience a break in build or boot behavior?
  • Examples: Add a new library class, move a module to a different repo, call a function in a new library class in a pre-existing module, ...
• [ ] Includes tests?
  • Tests - Does the change include any explicit test code?
  • Examples: Unit tests, integration tests, robot tests, ...
• [ ] Includes documentation?
  • Documentation - Does the change contain explicit documentation additions outside direct code modifications (and comments)?
  • Examples: Update readme file, add feature readme file, link to documentation on an a separate Web page, ...

How This Was Tested

Local CI

Integration Instructions

N/A

[kuqin12]

How is the PCD get used?

[apop5]

How is the PCD get used?

A Silicon Vendor provided their own implementation of SmmCpuFeaturesLib that requires the usage of the PCD.

Edk2 adding changes to consume it, then reverted the changes

Initial Addition https://github.com/tianocore/edk2/commit/cb3134612d11102fe066c94c8fa7edb20d62c1a8 Revert: https://github.com/tianocore/edk2/commit/4efcd654ecd94b91bd45da79583f114a0fa12a87