MpInitLib: Put SEV logic in separate file

The patch does several simplifications:
1. Treat SwitchToRealProc as part of RendezvousFunnelProc.
   So the common logic in MpLib.c doesn't need to be aware of
   SwitchToRealProc.
   As a result, SwitchToRealSize/Offset are removed from
   MP_ASSEMBLY_ADDRESS_MAP.

2. Move SwitchToRealProc to AmdSev.nasm.
   All other assembly code in AmdSev.nasm is called through
   OneTimeCall.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>

UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm

@@ -199,7 +199,6 @@ CProcedureInvoke:
     call       eax               ; Invoke C function
 
     jmp        $                 ; Never reach here
-RendezvousFunnelProcEnd:
 
 ;-------------------------------------------------------------------------------------
 ;SwitchToRealProc procedure follows.
@@ -209,6 +208,8 @@ SwitchToRealProcStart:
     jmp        $                 ; Never reach here
 SwitchToRealProcEnd:
 
+RendezvousFunnelProcEnd:
+
 ;-------------------------------------------------------------------------------------
 ;  AsmRelocateApLoop (MwaitSupport, ApTargetCState, PmCodeSegment, TopOfApStack, CountTofinish, Pm16CodeSegment, SevEsAPJumpTable, WakeupBuffer);
 ;
@@ -258,8 +259,6 @@ ASM_PFX(AsmGetAddressMap):
     mov        dword [ebx + MP_ASSEMBLY_ADDRESS_MAP.RelocateApLoopFuncAddress], AsmRelocateApLoopStart
     mov        dword [ebx + MP_ASSEMBLY_ADDRESS_MAP.RelocateApLoopFuncSize], AsmRelocateApLoopEnd - AsmRelocateApLoopStart
     mov        dword [ebx + MP_ASSEMBLY_ADDRESS_MAP.ModeTransitionOffset], Flat32Start - RendezvousFunnelProcStart
-    mov        dword [ebx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealSize], SwitchToRealProcEnd - SwitchToRealProcStart
-    mov        dword [ebx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealOffset], SwitchToRealProcStart - RendezvousFunnelProcStart
     mov        dword [ebx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealNoNxOffset], SwitchToRealProcStart - Flat32Start
     mov        dword [ebx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealPM16ModeOffset], 0
     mov        dword [ebx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealPM16ModeSize], 0

UefiCpuPkg/Library/MpInitLib/MpEqu.inc

@@ -1,5 +1,5 @@
 ;------------------------------------------------------------------------------ ;
-; Copyright (c) 2015 - 2021, Intel Corporation. All rights reserved.<BR>
+; Copyright (c) 2015 - 2022, Intel Corporation. All rights reserved.<BR>
 ; SPDX-License-Identifier: BSD-2-Clause-Patent
 ;
 ; Module Name:
@@ -27,8 +27,6 @@ struc MP_ASSEMBLY_ADDRESS_MAP
   .RelocateApLoopFuncAddress     CTYPE_UINTN 1
   .RelocateApLoopFuncSize        CTYPE_UINTN 1
   .ModeTransitionOffset          CTYPE_UINTN 1
-  .SwitchToRealSize              CTYPE_UINTN 1
-  .SwitchToRealOffset            CTYPE_UINTN 1
   .SwitchToRealNoNxOffset        CTYPE_UINTN 1
   .SwitchToRealPM16ModeOffset    CTYPE_UINTN 1
   .SwitchToRealPM16ModeSize      CTYPE_UINTN 1

UefiCpuPkg/Library/MpInitLib/MpLib.c

@@ -936,8 +936,7 @@ FillExchangeInfoData (
   // EfiBootServicesCode to avoid page fault if NX memory protection is enabled.
   //
   if (CpuMpData->WakeupBufferHigh != 0) {
-    Size = CpuMpData->AddressMap.RendezvousFunnelSize +
+    Size = CpuMpData->AddressMap.RendezvousFunnelSize -
-           CpuMpData->AddressMap.SwitchToRealSize -
            CpuMpData->AddressMap.ModeTransitionOffset;
     CopyMem (
       (VOID *)CpuMpData->WakeupBufferHigh,
@@ -991,8 +990,7 @@ BackupAndPrepareWakeupBuffer (
   CopyMem (
     (VOID *)CpuMpData->WakeupBuffer,
     (VOID *)CpuMpData->AddressMap.RendezvousFunnelAddress,
-    CpuMpData->AddressMap.RendezvousFunnelSize +
+    CpuMpData->AddressMap.RendezvousFunnelSize
-    CpuMpData->AddressMap.SwitchToRealSize
     );
 }
 
@@ -1029,7 +1027,6 @@ GetApResetVectorSize (
   UINTN  Size;
 
   Size = AddressMap->RendezvousFunnelSize +
-         AddressMap->SwitchToRealSize +
          sizeof (MP_CPU_EXCHANGE_INFO);
 
   return Size;
@@ -1054,11 +1051,9 @@ AllocateResetVector (
     CpuMpData->WakeupBuffer      = GetWakeupBuffer (ApResetVectorSize);
     CpuMpData->MpCpuExchangeInfo = (MP_CPU_EXCHANGE_INFO *)(UINTN)
                                    (CpuMpData->WakeupBuffer +
-                                    CpuMpData->AddressMap.RendezvousFunnelSize +
+                                    CpuMpData->AddressMap.RendezvousFunnelSize);
-                                    CpuMpData->AddressMap.SwitchToRealSize);
     CpuMpData->WakeupBufferHigh = AllocateCodeBuffer (
-                                    CpuMpData->AddressMap.RendezvousFunnelSize +
+                                    CpuMpData->AddressMap.RendezvousFunnelSize -
-                                    CpuMpData->AddressMap.SwitchToRealSize -
                                     CpuMpData->AddressMap.ModeTransitionOffset
                                     );
     //

UefiCpuPkg/Library/MpInitLib/MpLib.h

@@ -1,7 +1,7 @@
 /** @file
   Common header file for MP Initialize Library.
 
-  Copyright (c) 2016 - 2021, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2016 - 2022, Intel Corporation. All rights reserved.<BR>
   Copyright (c) 2020, AMD Inc. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -181,8 +181,6 @@ typedef struct {
   UINT8    *RelocateApLoopFuncAddress;
   UINTN    RelocateApLoopFuncSize;
   UINTN    ModeTransitionOffset;
-  UINTN    SwitchToRealSize;
-  UINTN    SwitchToRealOffset;
   UINTN    SwitchToRealNoNxOffset;
   UINTN    SwitchToRealPM16ModeOffset;
   UINTN    SwitchToRealPM16ModeSize;

UefiCpuPkg/Library/MpInitLib/X64/AmdSev.nasm

@@ -198,3 +198,151 @@ RestoreGhcb:
 
 SevEsGetApicIdExit:
     OneTimeCallRet    SevEsGetApicId
+
+
+;-------------------------------------------------------------------------------------
+;SwitchToRealProc procedure follows.
+;ALSO THIS PROCEDURE IS EXECUTED BY APs TRANSITIONING TO 16 BIT MODE. HENCE THIS PROC
+;IS IN MACHINE CODE.
+;  SwitchToRealProc (UINTN BufferStart, UINT16 Code16, UINT16 Code32, UINTN StackStart)
+;  rcx - Buffer Start
+;  rdx - Code16 Selector Offset
+;  r8  - Code32 Selector Offset
+;  r9  - Stack Start
+;-------------------------------------------------------------------------------------
+SwitchToRealProcStart:
+BITS 64
+    cli
+
+    ;
+    ; Get RDX reset value before changing stacks since the
+    ; new stack won't be able to accomodate a #VC exception.
+    ;
+    push       rax
+    push       rbx
+    push       rcx
+    push       rdx
+
+    mov        rax, 1
+    cpuid
+    mov        rsi, rax                    ; Save off the reset value for RDX
+
+    pop        rdx
+    pop        rcx
+    pop        rbx
+    pop        rax
+
+    ;
+    ; Establish stack below 1MB
+    ;
+    mov        rsp, r9
+
+    ;
+    ; Push ultimate Reset Vector onto the stack
+    ;
+    mov        rax, rcx
+    shr        rax, 4
+    push       word 0x0002                 ; RFLAGS
+    push       ax                          ; CS
+    push       word 0x0000                 ; RIP
+    push       word 0x0000                 ; For alignment, will be discarded
+
+    ;
+    ; Get address of "16-bit operand size" label
+    ;
+    lea        rbx, [PM16Mode]
+
+    ;
+    ; Push addresses used to change to compatibility mode
+    ;
+    lea        rax, [CompatMode]
+    push       r8
+    push       rax
+
+    ;
+    ; Clear R8 - R15, for reset, before going into 32-bit mode
+    ;
+    xor        r8, r8
+    xor        r9, r9
+    xor        r10, r10
+    xor        r11, r11
+    xor        r12, r12
+    xor        r13, r13
+    xor        r14, r14
+    xor        r15, r15
+
+    ;
+    ; Far return into 32-bit mode
+    ;
+    retfq
+
+BITS 32
+CompatMode:
+    ;
+    ; Set up stack to prepare for exiting protected mode
+    ;
+    push       edx                         ; Code16 CS
+    push       ebx                         ; PM16Mode label address
+
+    ;
+    ; Disable paging
+    ;
+    mov        eax, cr0                    ; Read CR0
+    btr        eax, 31                     ; Set PG=0
+    mov        cr0, eax                    ; Write CR0
+
+    ;
+    ; Disable long mode
+    ;
+    mov        ecx, 0c0000080h             ; EFER MSR number
+    rdmsr                                  ; Read EFER
+    btr        eax, 8                      ; Set LME=0
+    wrmsr                                  ; Write EFER
+
+    ;
+    ; Disable PAE
+    ;
+    mov        eax, cr4                    ; Read CR4
+    btr        eax, 5                      ; Set PAE=0
+    mov        cr4, eax                    ; Write CR4
+
+    mov        edx, esi                    ; Restore RDX reset value
+
+    ;
+    ; Switch to 16-bit operand size
+    ;
+    retf
+
+BITS 16
+    ;
+    ; At entry to this label
+    ;   - RDX will have its reset value
+    ;   - On the top of the stack
+    ;     - Alignment data (two bytes) to be discarded
+    ;     - IP for Real Mode (two bytes)
+    ;     - CS for Real Mode (two bytes)
+    ;
+    ; This label is also used with AsmRelocateApLoop. During MP finalization,
+    ; the code from PM16Mode to SwitchToRealProcEnd is copied to the start of
+    ; the WakeupBuffer, allowing a parked AP to be booted by an OS.
+    ;
+PM16Mode:
+    mov        eax, cr0                    ; Read CR0
+    btr        eax, 0                      ; Set PE=0
+    mov        cr0, eax                    ; Write CR0
+
+    pop        ax                          ; Discard alignment data
+
+    ;
+    ; Clear registers (except RDX and RSP) before going into 16-bit mode
+    ;
+    xor        eax, eax
+    xor        ebx, ebx
+    xor        ecx, ecx
+    xor        esi, esi
+    xor        edi, edi
+    xor        ebp, ebp
+
+    iret
+
+SwitchToRealProcEnd:

UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm

@@ -152,11 +152,6 @@ SkipEnable5LevelPaging:
 
 BITS 64
 
-;
-; Required for the AMD SEV helper functions
-;
-%include "AmdSev.nasm"
-
 LongModeStart:
     mov        esi, ebx
     lea        edi, [esi + MP_CPU_EXCHANGE_INFO_FIELD (InitFlag)]
@@ -265,155 +260,13 @@ CProcedureInvoke:
     add        rsp, 20h
     jmp        $                 ; Should never reach here
 
+;
+; Required for the AMD SEV helper functions
+;
+%include "AmdSev.nasm"
+
 RendezvousFunnelProcEnd:
 
-;-------------------------------------------------------------------------------------
-;SwitchToRealProc procedure follows.
-;ALSO THIS PROCEDURE IS EXECUTED BY APs TRANSITIONING TO 16 BIT MODE. HENCE THIS PROC
-;IS IN MACHINE CODE.
-;  SwitchToRealProc (UINTN BufferStart, UINT16 Code16, UINT16 Code32, UINTN StackStart)
-;  rcx - Buffer Start
-;  rdx - Code16 Selector Offset
-;  r8  - Code32 Selector Offset
-;  r9  - Stack Start
-;-------------------------------------------------------------------------------------
-SwitchToRealProcStart:
-BITS 64
-    cli
-
-    ;
-    ; Get RDX reset value before changing stacks since the
-    ; new stack won't be able to accomodate a #VC exception.
-    ;
-    push       rax
-    push       rbx
-    push       rcx
-    push       rdx
-
-    mov        rax, 1
-    cpuid
-    mov        rsi, rax                    ; Save off the reset value for RDX
-
-    pop        rdx
-    pop        rcx
-    pop        rbx
-    pop        rax
-
-    ;
-    ; Establish stack below 1MB
-    ;
-    mov        rsp, r9
-
-    ;
-    ; Push ultimate Reset Vector onto the stack
-    ;
-    mov        rax, rcx
-    shr        rax, 4
-    push       word 0x0002                 ; RFLAGS
-    push       ax                          ; CS
-    push       word 0x0000                 ; RIP
-    push       word 0x0000                 ; For alignment, will be discarded
-
-    ;
-    ; Get address of "16-bit operand size" label
-    ;
-    lea        rbx, [PM16Mode]
-
-    ;
-    ; Push addresses used to change to compatibility mode
-    ;
-    lea        rax, [CompatMode]
-    push       r8
-    push       rax
-
-    ;
-    ; Clear R8 - R15, for reset, before going into 32-bit mode
-    ;
-    xor        r8, r8
-    xor        r9, r9
-    xor        r10, r10
-    xor        r11, r11
-    xor        r12, r12
-    xor        r13, r13
-    xor        r14, r14
-    xor        r15, r15
-
-    ;
-    ; Far return into 32-bit mode
-    ;
-    retfq
-
-BITS 32
-CompatMode:
-    ;
-    ; Set up stack to prepare for exiting protected mode
-    ;
-    push       edx                         ; Code16 CS
-    push       ebx                         ; PM16Mode label address
-
-    ;
-    ; Disable paging
-    ;
-    mov        eax, cr0                    ; Read CR0
-    btr        eax, 31                     ; Set PG=0
-    mov        cr0, eax                    ; Write CR0
-
-    ;
-    ; Disable long mode
-    ;
-    mov        ecx, 0c0000080h             ; EFER MSR number
-    rdmsr                                  ; Read EFER
-    btr        eax, 8                      ; Set LME=0
-    wrmsr                                  ; Write EFER
-
-    ;
-    ; Disable PAE
-    ;
-    mov        eax, cr4                    ; Read CR4
-    btr        eax, 5                      ; Set PAE=0
-    mov        cr4, eax                    ; Write CR4
-
-    mov        edx, esi                    ; Restore RDX reset value
-
-    ;
-    ; Switch to 16-bit operand size
-    ;
-    retf
-
-BITS 16
-    ;
-    ; At entry to this label
-    ;   - RDX will have its reset value
-    ;   - On the top of the stack
-    ;     - Alignment data (two bytes) to be discarded
-    ;     - IP for Real Mode (two bytes)
-    ;     - CS for Real Mode (two bytes)
-    ;
-    ; This label is also used with AsmRelocateApLoop. During MP finalization,
-    ; the code from PM16Mode to SwitchToRealProcEnd is copied to the start of
-    ; the WakeupBuffer, allowing a parked AP to be booted by an OS.
-    ;
-PM16Mode:
-    mov        eax, cr0                    ; Read CR0
-    btr        eax, 0                      ; Set PE=0
-    mov        cr0, eax                    ; Write CR0
-
-    pop        ax                          ; Discard alignment data
-
-    ;
-    ; Clear registers (except RDX and RSP) before going into 16-bit mode
-    ;
-    xor        eax, eax
-    xor        ebx, ebx
-    xor        ecx, ecx
-    xor        esi, esi
-    xor        edi, edi
-    xor        ebp, ebp
-
-    iret
-
-SwitchToRealProcEnd:
-
 ;-------------------------------------------------------------------------------------
 ;  AsmRelocateApLoop (MwaitSupport, ApTargetCState, PmCodeSegment, TopOfApStack, CountTofinish, Pm16CodeSegment, SevEsAPJumpTable, WakeupBuffer);
 ;-------------------------------------------------------------------------------------
@@ -596,8 +449,6 @@ ASM_PFX(AsmGetAddressMap):
     mov        qword [rcx + MP_ASSEMBLY_ADDRESS_MAP.RelocateApLoopFuncAddress], rax
     mov        qword [rcx + MP_ASSEMBLY_ADDRESS_MAP.RelocateApLoopFuncSize], AsmRelocateApLoopEnd - AsmRelocateApLoopStart
     mov        qword [rcx + MP_ASSEMBLY_ADDRESS_MAP.ModeTransitionOffset], Flat32Start - RendezvousFunnelProcStart
-    mov        qword [rcx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealSize], SwitchToRealProcEnd - SwitchToRealProcStart
-    mov        qword [rcx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealOffset], SwitchToRealProcStart - RendezvousFunnelProcStart
     mov        qword [rcx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealNoNxOffset], SwitchToRealProcStart - Flat32Start
     mov        qword [rcx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealPM16ModeOffset], PM16Mode - RendezvousFunnelProcStart
     mov        qword [rcx + MP_ASSEMBLY_ADDRESS_MAP.SwitchToRealPM16ModeSize], SwitchToRealProcEnd - PM16Mode