UefiPayloadPkg/SmmStoreLib: honor SMI retry delay#12859
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The retry path loads RCX before REP PAUSE, but PAUSE already uses the REP prefix and does not consume RCX. It therefore waits for one PAUSE instruction instead of the intended 10,000 iterations. Use an explicit loop so a missed synchronous SMI gets the intended delay before it is retriggered. Signed-off-by: Sean Rhodes <sean@starlabs.systems>
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July 23, 2026 06:21
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Description
TriggerSmi()loads RCX with 10,000 beforerep pause, butPAUSEalready uses the REP prefix and does not consume RCX. The retry path therefore waits for one instruction rather than the intended delay.Use an explicit loop and retain the existing delay and retry counts. This replaces the broader SMMSTORE retry change from #12342; it does not call boot services from the runtime path or replay operations after an explicit SMM response.
How This Was Tested
PatchCheck.pystuart_buildfor UefiPayloadPkg X64 FITPAUSEis followed byLOOPto the pause labelIntegration Instructions
None.