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>

6 files changed, 161 insertions, 172 deletions

diff --git a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
index 8981c32722..28301bb8f0 100644
--- a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
+++ b/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

diff --git a/UefiCpuPkg/Library/MpInitLib/MpEqu.inc b/UefiCpuPkg/Library/MpInitLib/MpEqu.inc
index aba53f5720..1cc071cf7b 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpEqu.inc
+++ b/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

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index d761bdc487..aa0eb9a70b 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/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 +

-           CpuMpData->AddressMap.SwitchToRealSize -

+    Size = CpuMpData->AddressMap.RendezvousFunnelSize -

            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.SwitchToRealSize

+    CpuMpData->AddressMap.RendezvousFunnelSize

     );

 }

 

@@ -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.SwitchToRealSize);

+                                    CpuMpData->AddressMap.RendezvousFunnelSize);

     CpuMpData->WakeupBufferHigh = AllocateCodeBuffer (

-                                    CpuMpData->AddressMap.RendezvousFunnelSize +

-                                    CpuMpData->AddressMap.SwitchToRealSize -

+                                    CpuMpData->AddressMap.RendezvousFunnelSize -

                                     CpuMpData->AddressMap.ModeTransitionOffset

                                     );

     //

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index 59ab960897..974fb76019 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/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;

diff --git a/UefiCpuPkg/Library/MpInitLib/X64/AmdSev.nasm b/UefiCpuPkg/Library/MpInitLib/X64/AmdSev.nasm
index 8bb1161fa0..7c2469f9c5 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/AmdSev.nasm
+++ b/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:

diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
index d7e0e1fabd..1daaa72b1e 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
+++ b/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)]

@@ -265,154 +260,12 @@ CProcedureInvoke:
     add        rsp, 20h

     jmp        $                 ; Should never reach here

 

-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

+;

+; Required for the AMD SEV helper functions

+;

+%include "AmdSev.nasm"

 

-SwitchToRealProcEnd:

+RendezvousFunnelProcEnd:

 

 ;-------------------------------------------------------------------------------------

 ;  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