#GP exception is raised when writing 0x790 MSR

[Cypaps]

Hello,

A system with ICX server processors (Dx/M1 steppings) cannot fully boot into the EFI shell when using a UEFI firmware image with updated microcode. Through experimentation, it was found that a #GP exception occurs when trying to write in SMM mode an undocumented MSR 0x790 with a value of '0'. This behavior is characteristic of microcode versions: 0x0d0003a5, 0x0d0003b9, 0x0d0003d1, 0x0d0003e7. When using a UEFI firmware image with microcode version 0x0d000390, the system successfully boots into the EFI shell. The release notes for SFUP R01.01.0009 mention a similar issue: [IPU2023.3][HSD]:[14018718770] BIOS writes 0x790 before BIOS_DONE caused GPF when DAM is not enabled. However, the point is that the Delayed Authentication Mode is enabled in the UEFI firmware image, as verified using the spsFITc utility.

How can this behavior be fixed?

[Sreelakshmi1]

Hi Cypaps,

Greetings!

Thank you for posting in the Intel Community Forum.

To assist you further, could you please provide the following details:

>The system information or server model you are using.

>The complete model name of the processor.

>A screenshot of the error message, if available.

Regards,

Sreelakshmi Balakrishnan

Intel customer support Technician

intel.com/vroc

[Sreelakshmi1]

Hi Cypaps,

Greetings!

We are following up to check if you were able to find the information we requested. Kindly confirm at your earliest convenience, so that we can continue assisting you in resolving this matter.

Regards,

Sreelakshmi Balakrishnan

Intel customer support Technician

intel.com/vroc

[Sreelakshmi1]

Hi Cypaps,

Greetings!

We would like to inform you that we are closing this request as no response has been received from our previous follow-ups. Please don't hesitate to ask any further questions in the future. Feel free to start a new conversation, as this thread will no longer be monitored.

Regards,

Sreelakshmi Balakrishnan

Intel customer support Technician

intel.com/vroc