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UefiCpuPkg/DxeMpLib: Allocate new safe stack < 4GB

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For long mode DXE, we will disable paging on AP to protected mode to execute AP
safe loop code in reserved memory range under 4GB. But we forget to allocate
stack for AP under 4GB and AP still are using original AP stack. If original AP
stack is larger than 4GB, it cannot be used after AP is transferred to protected
mode. Besides MwaitSupport == TRUE, AP stack is still required during phase of
disabling paging in long mode DXE.

Moreover, even though AP stack is always under 4GB (a) in Ia32 DXE and (b) with
this patch, after transferring to protected mode from X64 DXE, AP stack
(in BootServiceData) maybe crashed by OS after Exit Boot Service event.

This fix is to allocate reserved memory range under 4GB together with AP safe
loop code. APs will switch to new stack in safe loop code.

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Jeff Fan
2016-11-23 21:52:24 +08:00
parent 081f6416ff
commit bf2786dc79
4 changed files with 31 additions and 7 deletions
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13
UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
View File

@@ -215,19 +215,26 @@ CProcedureInvoke:
RendezvousFunnelProcEnd:
;-------------------------------------------------------------------------------------
; AsmRelocateApLoop (MwaitSupport, ApTargetCState, PmCodeSegment);
; AsmRelocateApLoop (MwaitSupport, ApTargetCState, PmCodeSegment, TopOfApStack);
;-------------------------------------------------------------------------------------
global ASM_PFX(AsmRelocateApLoop)
ASM_PFX(AsmRelocateApLoop):
AsmRelocateApLoopStart:
cmp byte [esp + 4], 1
mov eax, esp
mov esp, [eax + 16] ; TopOfApStack
push dword [eax] ; push return address for stack trace
push ebp
mov ebp, esp
mov ebx, [eax + 8] ; ApTargetCState
mov ecx, [eax + 4] ; MwaitSupport
cmp cl, 1 ; Check mwait-monitor support
jnz HltLoop
MwaitLoop:
mov eax, esp
xor ecx, ecx
xor edx, edx
monitor
mov eax, [esp + 8] ; Mwait Cx, Target C-State per eax[7:4]
mov eax, ebx ; Mwait Cx, Target C-State per eax[7:4]
shl eax, 4
mwait
jmp MwaitLoop