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MpInitLib: Put SEV logic in separate file

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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>
This commit is contained in:
Ray Ni
2022-05-07 21:19:08 +08:00
committed by mergify[bot]
parent 76323c3145
commit b4d7b9d2b5
6 changed files with 161 additions and 172 deletions
Download Patch File Download Diff File Expand all files Collapse all files

148
UefiCpuPkg/Library/MpInitLib/X64/AmdSev.nasm
View File

@@ -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:

159
UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
View File

@@ -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