Files
system76-edk2/OvmfPkg/Sec/X64/SecEntry.nasm
Min Xu 2b80269d98 OvmfPkg: Update Sec to support Tdx
RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

There are below major changes in this commit.

1. SecEntry.nasm
In TDX BSP and APs goes to the same entry point in SecEntry.nasm.

BSP initialize the temporary stack and then jumps to SecMain, just as
legacy Ovmf does.

APs spin in a modified mailbox loop using initial mailbox structure.
Its structure defition is in OvmfPkg/Include/IndustryStandard/IntelTdx.h.
APs wait for command to see if the command is for me. If so execute the
command.

2. Sec/SecMain.c
When host VMM create the Td guest, the system memory informations are
stored in TdHob, which is a memory region described in Tdx metadata.
The system memory region in TdHob should be accepted before it can be
accessed. So the major task of this patch is to process the TdHobList
to accept the memory. After that TDVF follow the standard OVMF flow
and jump to PEI phase.

PcdUse1GPageTable is set to FALSE by default in OvmfPkgX64.dsc. It gives
no chance for Intel TDX to support 1G page table. To support 1G page
table this PCD is set to TRUE in OvmfPkgX64.dsc.

TDX_GUEST_SUPPORTED is defined in OvmfPkgX64.dsc. This macro wraps the
Tdx specific code.

TDX only works on X64, so the code is only valid in X64 arch.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
2022-04-02 08:15:12 +00:00

152 lines
4.4 KiB
NASM

;------------------------------------------------------------------------------
;*
;* Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
;* SPDX-License-Identifier: BSD-2-Clause-Patent
;*
;* CpuAsm.asm
;*
;* Abstract:
;*
;------------------------------------------------------------------------------
#include <Base.h>
%include "TdxCommondefs.inc"
DEFAULT REL
SECTION .text
extern ASM_PFX(SecCoreStartupWithStack)
%macro tdcall 0
db 0x66, 0x0f, 0x01, 0xcc
%endmacro
;
; SecCore Entry Point
;
; Processor is in flat protected mode
;
; @param[in] RAX Initial value of the EAX register (BIST: Built-in Self Test)
; @param[in] DI 'BP': boot-strap processor, or 'AP': application processor
; @param[in] RBP Pointer to the start of the Boot Firmware Volume
; @param[in] DS Selector allowing flat access to all addresses
; @param[in] ES Selector allowing flat access to all addresses
; @param[in] FS Selector allowing flat access to all addresses
; @param[in] GS Selector allowing flat access to all addresses
; @param[in] SS Selector allowing flat access to all addresses
;
; @return None This routine does not return
;
global ASM_PFX(_ModuleEntryPoint)
ASM_PFX(_ModuleEntryPoint):
;
; Guest type is stored in OVMF_WORK_AREA
;
%define OVMF_WORK_AREA FixedPcdGet32 (PcdOvmfWorkAreaBase)
%define VM_GUEST_TYPE_TDX 2
mov eax, OVMF_WORK_AREA
cmp byte[eax], VM_GUEST_TYPE_TDX
jne InitStack
mov rax, TDCALL_TDINFO
tdcall
;
; R8 [31:0] NUM_VCPUS
; [63:32] MAX_VCPUS
; R9 [31:0] VCPU_INDEX
; Td Guest set the VCPU0 as the BSP, others are the APs
; APs jump to spinloop and get released by DXE's MpInitLib
;
mov rax, r9
and rax, 0xffff
test rax, rax
jne ParkAp
InitStack:
;
; Fill the temporary RAM with the initial stack value.
; The loop below will seed the heap as well, but that's harmless.
;
mov rax, (FixedPcdGet32 (PcdInitValueInTempStack) << 32) | FixedPcdGet32 (PcdInitValueInTempStack)
; qword to store
mov rdi, FixedPcdGet32 (PcdOvmfSecPeiTempRamBase) ; base address,
; relative to
; ES
mov rcx, FixedPcdGet32 (PcdOvmfSecPeiTempRamSize) / 8 ; qword count
cld ; store from base
; up
rep stosq
;
; Load temporary RAM stack based on PCDs
;
%define SEC_TOP_OF_STACK (FixedPcdGet32 (PcdOvmfSecPeiTempRamBase) + \
FixedPcdGet32 (PcdOvmfSecPeiTempRamSize))
mov rsp, SEC_TOP_OF_STACK
nop
;
; Setup parameters and call SecCoreStartupWithStack
; rcx: BootFirmwareVolumePtr
; rdx: TopOfCurrentStack
;
mov rcx, rbp
mov rdx, rsp
sub rsp, 0x20
call ASM_PFX(SecCoreStartupWithStack)
;
; Note: BSP never gets here. APs will be unblocked by DXE
;
; R8 [31:0] NUM_VCPUS
; [63:32] MAX_VCPUS
; R9 [31:0] VCPU_INDEX
;
ParkAp:
mov rbp, r9
.do_wait_loop:
mov rsp, FixedPcdGet32 (PcdOvmfSecGhcbBackupBase)
;
; register itself in [rsp + CpuArrivalOffset]
;
mov rax, 1
lock xadd dword [rsp + CpuArrivalOffset], eax
inc eax
.check_arrival_cnt:
cmp eax, r8d
je .check_command
mov eax, dword[rsp + CpuArrivalOffset]
jmp .check_arrival_cnt
.check_command:
mov eax, dword[rsp + CommandOffset]
cmp eax, MpProtectedModeWakeupCommandNoop
je .check_command
cmp eax, MpProtectedModeWakeupCommandWakeup
je .do_wakeup
; Don't support this command, so ignore
jmp .check_command
.do_wakeup:
;
; BSP sets these variables before unblocking APs
; RAX: WakeupVectorOffset
; RBX: Relocated mailbox address
; RBP: vCpuId
;
mov rax, 0
mov eax, dword[rsp + WakeupVectorOffset]
mov rbx, [rsp + WakeupArgsRelocatedMailBox]
nop
jmp rax
jmp $