loader/uefi: fix uefi enlightened snp cpuid page generation (#3965) - #4130
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Matt LaFayette (Kurjanowicz) (mattkur) merged 1 commit intoAug 4, 2026
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Pull request overview
Fixes a long-standing bug in UEFI SNP CPUID page generation for the “enlightened SNP” path by populating the correct CPUID input subleaf field. This brings the UEFI loader’s CPUID page construction in line with the existing paravisor/OpenHCL behavior.
Changes:
- Correctly writes the required CPUID subleaf value into
ecx_in(instead of incorrectly writing it intoeax_out). - Ensures generated
HV_PSP_CPUID_PAGEentries contain the expected CPUID input tuple(eax_in, ecx_in)while leaving outputs zeroed for the hypervisor to fill.
Steven Malis (smalis-msft)
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Aug 4, 2026
Matt LaFayette (Kurjanowicz) (mattkur)
merged commit Aug 4, 2026
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Matt LaFayette (Kurjanowicz) (mattkur)
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August 4, 2026 16:54
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Clean cherry pick of PR #3965
This seemed to have been a bug forever, but this configuration is not well tested. Now matches what we do for openhcl in paravisor.rs.