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| author | Jian J Wang <jian.j.wang@intel.com> | 2018-01-15 10:16:26 +0800 |
|---|---|---|
| committer | Ruiyu Ni <ruiyu.ni@intel.com> | 2018-01-18 17:03:24 +0800 |
| commit | d4d87596c11d6e3f8220b6d9677797c802af3a33 (patch) | |
| tree | 5f90142f10af7be15433ed20f30f6f26d3be9619 /UefiCpuPkg/PiSmmCpuDxeSmm/Ia32 | |
| parent | fbe2c4b9be98a5c2b9c1f6976f51e2456467e752 (diff) | |
| download | edk2-d4d87596c11d6e3f8220b6d9677797c802af3a33.tar.gz edk2-d4d87596c11d6e3f8220b6d9677797c802af3a33.tar.bz2 edk2-d4d87596c11d6e3f8220b6d9677797c802af3a33.zip | |
UefiCpuPkg/PiSmmCpuDxeSmm: Enable NXE if it's supported
If PcdDxeNxMemoryProtectionPolicy is set to enable protection for memory
of EfiBootServicesCode, EfiConventionalMemory, the BIOS will hang at a page
fault exception triggered by PiSmmCpuDxeSmm.
The root cause is that PiSmmCpuDxeSmm will access default SMM RAM starting
at 0x30000 which is marked as non-executable, but NX feature was not
enabled during SMM initialization. Accessing memory which has invalid
attributes set will cause page fault exception. This patch fixes it by
checking NX capability in cpuid and enable NXE in EFER MSR if it's
available.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Diffstat (limited to 'UefiCpuPkg/PiSmmCpuDxeSmm/Ia32')
| -rw-r--r-- | UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm index a5c62e77ce..e96dd8d239 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm @@ -42,6 +42,11 @@ ASM_PFX(gcSmiInitGdtr): global ASM_PFX(SmmStartup)
ASM_PFX(SmmStartup):
+ DB 0x66
+ mov eax, 0x80000001 ; read capability
+ cpuid
+ DB 0x66
+ mov ebx, edx ; rdmsr will change edx. keep it in ebx.
DB 0x66, 0xb8
ASM_PFX(gSmmCr3): DD 0
mov cr3, eax
@@ -50,6 +55,15 @@ ASM_PFX(gSmmCr3): DD 0 DB 0x66, 0xb8
ASM_PFX(gSmmCr4): DD 0
mov cr4, eax
+ DB 0x66
+ mov ecx, 0xc0000080 ; IA32_EFER MSR
+ rdmsr
+ DB 0x66
+ test ebx, BIT20 ; check NXE capability
+ jz .1
+ or ah, BIT3 ; set NXE bit
+ wrmsr
+.1:
DB 0x66, 0xb8
ASM_PFX(gSmmCr0): DD 0
DB 0xbf, PROTECT_MODE_DS, 0 ; mov di, PROTECT_MODE_DS
|