Reviewed-by: Jeff Fan <[email protected]> -----Original Message----- From: Kinney, Michael D Sent: Wednesday, December 23, 2015 7:51 AM To: [email protected] Cc: Fan, Jeff Subject: [Patch] UefiCpuPkg/PiSmmCpuDxeSmm: Correct CPUID leaf used to detect SMM mode
Use Bit 29 of CPUID leaf CPUID_EXTENDED_CPU_SIG (0x80000001) to determine the SMM save state mode. The previous version of this code used CPUID leaf CPUID_VERSION_INFO (0x00000001). Cc: Jeff Fan <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Michael Kinney <[email protected]> --- UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c index fb46551..949dd4e 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c @@ -913,13 +913,18 @@ PiCpuSmmEntry ( // // Retrieve CPU Family // - AsmCpuid (CPUID_VERSION_INFO, &RegEax, NULL, NULL, &RegEdx); + AsmCpuid (CPUID_VERSION_INFO, &RegEax, NULL, NULL, NULL); FamilyId = (RegEax >> 8) & 0xf; ModelId = (RegEax >> 4) & 0xf; if (FamilyId == 0x06 || FamilyId == 0x0f) { ModelId = ModelId | ((RegEax >> 12) & 0xf0); } + RegEdx = 0; + AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL); if + (RegEax >= CPUID_EXTENDED_CPU_SIG) { + AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &RegEdx); } // // Determine the mode of the CPU at the time an SMI occurs // Intel(R) 64 and IA-32 Architectures Software Developer's Manual -- 2.6.3.windows.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
