Unlike "gSmmCr3" in the previous patch, "gSmmCr4" is not only used for machine code patching, but also as a means to communicate the initial CR4 value from SmmRelocateBases() to InitSmmS3ResumeState(). In other words, the last four bytes of the "mov eax, Cr4Value" instruction's binary representation are utilized as normal data too.
In order to get rid of the DB for "mov eax, Cr4Value", we have to split both roles, patching and data flow. Introduce the "mSmmCr4" global (SMRAM) variable for the data flow purpose. Rename the "gSmmCr4" variable to "gPatchSmmCr4" so that its association with PatchInstructionX86() is clear from the declaration, change its type to X86_ASSEMBLY_PATCH_LABEL, and patch it with PatchInstructionX86(), to the value now contained in "mSmmCr4". This lets us remove the binary (DB) encoding of "mov eax, Cr4Value" in "SmmInit.nasm". Cc: Eric Dong <[email protected]> Cc: Michael D Kinney <[email protected]> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=866 Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek <[email protected]> --- Notes: v2: - use the X86_ASSEMBLY_PATCH_LABEL type rather than UINT8 [Mike] UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h | 3 ++- UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm | 6 +++--- UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm | 6 +++--- UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c | 2 +- UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 8 +++++++- 5 files changed, 16 insertions(+), 9 deletions(-) diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h index 31633498e178..f6eddf7e0199 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h @@ -310,7 +310,8 @@ extern CONST UINT8 gcSmmInitTemplate[]; extern CONST UINT16 gcSmmInitSize; extern UINT32 gSmmCr0; X86_ASSEMBLY_PATCH_LABEL gPatchSmmCr3; -extern UINT32 gSmmCr4; +extern UINT32 mSmmCr4; +X86_ASSEMBLY_PATCH_LABEL gPatchSmmCr4; extern UINTN gSmmInitStack; /** diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm index f7bb9b9a82e5..bd07a6e4f536 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm @@ -23,7 +23,7 @@ extern ASM_PFX(mRebasedFlag) extern ASM_PFX(mSmmRelocationOriginalAddress) global ASM_PFX(gPatchSmmCr3) -global ASM_PFX(gSmmCr4) +global ASM_PFX(gPatchSmmCr4) global ASM_PFX(gSmmCr0) global ASM_PFX(gSmmJmpAddr) global ASM_PFX(gSmmInitStack) @@ -53,8 +53,8 @@ ASM_PFX(SmmStartup): ASM_PFX(gPatchSmmCr3): mov cr3, eax o32 lgdt [cs:ebp + (ASM_PFX(gcSmiInitGdtr) - ASM_PFX(SmmStartup))] - DB 0x66, 0xb8 ; mov eax, imm32 -ASM_PFX(gSmmCr4): DD 0 + mov eax, strict dword 0 ; source operand will be patched +ASM_PFX(gPatchSmmCr4): mov cr4, eax mov ecx, 0xc0000080 ; IA32_EFER MSR rdmsr diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm index 2df22a1f6cd1..971bd118132f 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm @@ -23,7 +23,7 @@ extern ASM_PFX(mRebasedFlag) extern ASM_PFX(mSmmRelocationOriginalAddress) global ASM_PFX(gPatchSmmCr3) -global ASM_PFX(gSmmCr4) +global ASM_PFX(gPatchSmmCr4) global ASM_PFX(gSmmCr0) global ASM_PFX(gSmmJmpAddr) global ASM_PFX(gSmmInitStack) @@ -51,8 +51,8 @@ ASM_PFX(SmmStartup): ASM_PFX(gPatchSmmCr3): mov cr3, eax o32 lgdt [cs:ebp + (ASM_PFX(gcSmiInitGdtr) - ASM_PFX(SmmStartup))] - DB 0x66, 0xb8 ; mov eax, imm32 -ASM_PFX(gSmmCr4): DD 0 + mov eax, strict dword 0 ; source operand will be patched +ASM_PFX(gPatchSmmCr4): or ah, 2 ; enable XMM registers access mov cr4, eax mov ecx, 0xc0000080 ; IA32_EFER MSR diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c index 554629536a5d..b4ed0a56a814 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c @@ -746,7 +746,7 @@ InitSmmS3ResumeState ( SmmS3ResumeState->SmmS3Cr0 = gSmmCr0; SmmS3ResumeState->SmmS3Cr3 = Cr3; - SmmS3ResumeState->SmmS3Cr4 = gSmmCr4; + SmmS3ResumeState->SmmS3Cr4 = mSmmCr4; if (sizeof (UINTN) == sizeof (UINT64)) { SmmS3ResumeState->Signature = SMM_S3_RESUME_SMM_64; diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c index c5b67e3dc0ce..a3fd796dba4a 100755 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c @@ -125,6 +125,11 @@ UINTN mSmmCpuSmramRangeCount; UINT8 mPhysicalAddressBits; +// +// Control register contents saved for SMM S3 resume state initialization. +// +UINT32 mSmmCr4; + /** Initialize IDT to setup exception handlers for SMM. @@ -407,7 +412,8 @@ SmmRelocateBases ( // gSmmCr0 = (UINT32)AsmReadCr0 (); PatchInstructionX86 (gPatchSmmCr3, AsmReadCr3 (), 4); - gSmmCr4 = (UINT32)AsmReadCr4 (); + mSmmCr4 = (UINT32)AsmReadCr4 (); + PatchInstructionX86 (gPatchSmmCr4, mSmmCr4, 4); // // Patch GDTR for SMM base relocation -- 2.14.1.3.gb7cf6e02401b _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
