X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=UefiCpuPkg%2FLibrary%2FMpInitLib%2FX64%2FMpFuncs.nasm;h=3c55ffaafecc53b37ba96417b9ea9e43a0000885;hp=848992ca4484293e1e17ecf7d713ec87facd529e;hb=5c66d125eaae51945c0a14ef6d5d3fa2ce7d7a66;hpb=8396e2dd30bf6f9057d3cd5fa1d26f023341f0a0

diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
index 848992ca44..3c55ffaafe 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
@@ -69,6 +69,19 @@ o32 lgdt       [cs:si]
     mov        si, IdtrLocation
 o32 lidt       [cs:si]
 
+    mov        si, EnableExecuteDisableLocation
+    cmp        byte [si], 0
+    jz         SkipEnableExecuteDisableBit
+
+    ;
+    ; Enable execute disable bit
+    ;
+    mov        ecx, 0c0000080h             ; EFER MSR number
+    rdmsr                                  ; Read EFER
+    bts        eax, 11                     ; Enable Execute Disable Bit
+    wrmsr                                  ; Write EFER
+
+SkipEnableExecuteDisableBit:
 
     mov        di,  DataSegmentLocation
     mov        edi, [di]                   ; Save long mode DS in edi