在 2025/7/12 11:03, James Bottomley 写道:
On Sat, 2025-07-12 at 10:55 +0800, yangge1116@126.com wrote:
From: Ge Yang yangge1116@126.com
Since commit d228814b1913 ("efi/libstub: Add get_event_log() support for CC platforms") reuses TPM2 support code for the CC platforms, when launching a TDX virtual machine with coco measurement enabled, the following error log is generated:
[Firmware Bug]: Failed to parse event in TPM Final Events Log
Call Trace: efi_config_parse_tables() efi_tpm_eventlog_init() tpm2_calc_event_log_size() __calc_tpm2_event_size()
The pcr_idx value in the Intel TDX log header is 1, causing the function __calc_tpm2_event_size() to fail to recognize the log header, ultimately leading to the "Failed to parse event in TPM Final Events Log" error.
According to UEFI Specification 2.10, Section 38.4.1: For TDX, TPM PCR 0 maps to MRTD, so the log header uses TPM PCR 1 instead.
This isn't a justification ... Intel just screwed up. Whatever the UEFI spec says about PCR mapping, the log spec the TCG produces requires the header event to have a pcrIndex of 0 and, since it isn't recorded in a PCR, it doesn't matter what the mapping is.
Just say Intel misread the spec and wrongly sets pcrIndex to 1 in the header and since they did this, we fear others might, so we're relaxing the header check.
OK, thanks.
Regards,
James