gistfile1.txt

From 99debcd71161935a3121d65d1b9ea5a51e702bce Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Tue, 22 Aug 2023 13:45:19 +0300
Subject: [PATCH] HACK: EDK2: Add support for ACPI MADT CPU reset vector and
 TEST command

Very ugly implementation of the draft of ACPI spec change. But it is
enough to test kernel side.
---
 MdePkg/Include/IndustryStandard/Acpi64.h    |  1 +
 OvmfPkg/Include/IndustryStandard/IntelTdx.h |  6 ++-
 OvmfPkg/Include/TdxCommondefs.inc           |  5 ++-
 OvmfPkg/TdxDxe/TdxAcpiTable.c               | 13 +++++-
 OvmfPkg/TdxDxe/TdxAcpiTable.h               |  2 +-
 OvmfPkg/TdxDxe/X64/ApRunLoop.nasm           | 46 +++++++++++++++++++++
 6 files changed, 66 insertions(+), 7 deletions(-)

diff --git a/MdePkg/Include/IndustryStandard/Acpi64.h b/MdePkg/Include/IndustryStandard/Acpi64.h
index 575ca0430c13..d728bb63f735 100644
--- a/MdePkg/Include/IndustryStandard/Acpi64.h
+++ b/MdePkg/Include/IndustryStandard/Acpi64.h
@@ -599,6 +599,7 @@ typedef struct {
   UINT16    MailBoxVersion;
   UINT32    Reserved;
   UINT64    MailBoxAddress;
+  UINT64    ResetVector;
 } EFI_ACPI_6_4_MULTIPROCESSOR_WAKEUP_STRUCTURE;
 
 ///
diff --git a/OvmfPkg/Include/IndustryStandard/IntelTdx.h b/OvmfPkg/Include/IndustryStandard/IntelTdx.h
index cc849be2fb59..68126b8a3cd4 100644
--- a/OvmfPkg/Include/IndustryStandard/IntelTdx.h
+++ b/OvmfPkg/Include/IndustryStandard/IntelTdx.h
@@ -20,8 +20,9 @@
 typedef enum {
   MpProtectedModeWakeupCommandNoop        = 0,
   MpProtectedModeWakeupCommandWakeup      = 1,
-  MpProtectedModeWakeupCommandSleep       = 2,
-  MpProtectedModeWakeupCommandAcceptPages = 3,
+  MpProtectedModeWakeupCommandTest        = 2,
+  MpProtectedModeWakeupCommandSleep       = 3,
+  MpProtectedModeWakeupCommandAcceptPages = 4,
 } MP_CPU_PROTECTED_MODE_WAKEUP_CMD;
 
 #pragma pack(1)
@@ -60,6 +61,7 @@ typedef struct {
 typedef struct {
   UINT8    *RelocateApLoopFuncAddress;
   UINTN    RelocateApLoopFuncSize;
+  UINT8    *RelocateApResetVector;
 } MP_RELOCATION_MAP;
 
 #pragma pack()
diff --git a/OvmfPkg/Include/TdxCommondefs.inc b/OvmfPkg/Include/TdxCommondefs.inc
index a29d2fad4233..200fa405731e 100644
--- a/OvmfPkg/Include/TdxCommondefs.inc
+++ b/OvmfPkg/Include/TdxCommondefs.inc
@@ -41,8 +41,9 @@ ERROR_INVALID_FALLBACK_PAGE_LEVEL         equ       3
 
 MpProtectedModeWakeupCommandNoop          equ       0
 MpProtectedModeWakeupCommandWakeup        equ       1
-MpProtectedModeWakeupCommandSleep         equ       2
-MpProtectedModeWakeupCommandAcceptPages   equ       3
+MpProtectedModeWakeupCommandTest          equ       2
+MpProtectedModeWakeupCommandSleep         equ       3
+MpProtectedModeWakeupCommandAcceptPages   equ       4
 
 MailboxApicIdInvalid                      equ       0xffffffff
 MailboxApicidBroadcast                    equ       0xfffffffe
diff --git a/OvmfPkg/TdxDxe/TdxAcpiTable.c b/OvmfPkg/TdxDxe/TdxAcpiTable.c
index 5dc27e23ad71..9c6079b64f89 100644
--- a/OvmfPkg/TdxDxe/TdxAcpiTable.c
+++ b/OvmfPkg/TdxDxe/TdxAcpiTable.c
@@ -42,7 +42,7 @@
 EFI_PHYSICAL_ADDRESS
 EFIAPI
 RelocateMailbox (
-  VOID
+  EFI_PHYSICAL_ADDRESS *ResetVector
   )
 {
   EFI_PHYSICAL_ADDRESS  Address;
@@ -115,6 +115,13 @@ RelocateMailbox (
     0
     );
 
+  *ResetVector = (UINT64)ApLoopFunc + (RelocationMap.RelocateApResetVector -
+				       RelocationMap.RelocateApLoopFuncAddress);
+  DEBUG ((
+    DEBUG_INFO,
+    "Ap Relocation: reset_vector %llx\n",
+    *ResetVector
+    ));
   return Address;
 }
 
@@ -142,6 +149,7 @@ AlterAcpiTable (
   UINT8                                                *NewMadtTable;
   UINTN                                                NewMadtTableLength;
   EFI_PHYSICAL_ADDRESS                                 RelocateMailboxAddress;
+  EFI_PHYSICAL_ADDRESS                                 RelocateResetVector;
   EFI_ACPI_6_4_MULTIPROCESSOR_WAKEUP_STRUCTURE         *MadtMpWk;
   EFI_ACPI_1_0_MULTIPLE_APIC_DESCRIPTION_TABLE_HEADER  *MadtHeader;
 
@@ -155,7 +163,7 @@ AlterAcpiTable (
     return;
   }
 
-  RelocateMailboxAddress = RelocateMailbox ();
+  RelocateMailboxAddress = RelocateMailbox (&RelocateResetVector);
   if (RelocateMailboxAddress == 0) {
     ASSERT (FALSE);
     DEBUG ((DEBUG_ERROR, "Failed to relocate Td mailbox\n"));
@@ -189,6 +197,7 @@ AlterAcpiTable (
       MadtMpWk->MailBoxVersion = 1;
       MadtMpWk->Reserved       = 0;
       MadtMpWk->MailBoxAddress = RelocateMailboxAddress;
+      MadtMpWk->ResetVector    = RelocateResetVector;
 
       Status = AcpiTableProtocol->InstallAcpiTable (AcpiTableProtocol, NewMadtTable, NewMadtTableLength, &NewTableKey);
       if (EFI_ERROR (Status)) {
diff --git a/OvmfPkg/TdxDxe/TdxAcpiTable.h b/OvmfPkg/TdxDxe/TdxAcpiTable.h
index 6b7615dc3687..8ffb9157bd21 100644
--- a/OvmfPkg/TdxDxe/TdxAcpiTable.h
+++ b/OvmfPkg/TdxDxe/TdxAcpiTable.h
@@ -41,7 +41,7 @@ AsmGetRelocationMap (
 EFI_PHYSICAL_ADDRESS
 EFIAPI
 RelocateMailbox (
-  VOID
+  EFI_PHYSICAL_ADDRESS *ResetVector
   );
 
 /**
diff --git a/OvmfPkg/TdxDxe/X64/ApRunLoop.nasm b/OvmfPkg/TdxDxe/X64/ApRunLoop.nasm
index 0bef89c48552..ece6a7973226 100644
--- a/OvmfPkg/TdxDxe/X64/ApRunLoop.nasm
+++ b/OvmfPkg/TdxDxe/X64/ApRunLoop.nasm
@@ -49,6 +49,15 @@ AsmRelocateApMailBoxLoopStart:
     test        r10, r10
     jnz         Panic
     mov         r8, r15
+    mov         qword[rel mailbox_address], rbx
+    mov         rax, cr0
+    mov         qword[rel saved_cr0], rax
+    mov         rax, cr3
+    mov         qword[rel saved_cr3], rax
+    mov         rax, cr4
+    mov         qword[rel saved_cr4], rax
+    lea         rax, qword[rel saved_gdt]
+    sgdt        [rax]
 
 MailBoxLoop:
     ; Spin until command set
@@ -62,6 +71,8 @@ MailBoxLoop:
 MailBoxProcessCommand:
     cmp        dword [rbx + CommandOffset], MpProtectedModeWakeupCommandWakeup
     je         MailBoxWakeUp
+    cmp        dword [rbx + CommandOffset], MpProtectedModeWakeupCommandTest
+    je         MailBoxTest
     cmp        dword [rbx + CommandOffset], MpProtectedModeWakeupCommandSleep
     je         MailBoxSleep
     ; Don't support this command, so ignore
@@ -72,10 +83,43 @@ MailBoxWakeUp:
     ; the command field back to zero as acknowledgement.
     mov        qword [rbx + CommandOffset], 0
     jmp        rax
+MailBoxTest:
+    mov        qword [rbx + CommandOffset], 0
+    jmp        MailBoxLoop
 MailBoxSleep:
     jmp       $
 Panic:
     ud2
+AsmRelocateApResetVector:
+    ; FIXME: handle switch to paging mode matching CR3
+    mov      rbx, qword[rel mailbox_address]
+    mov      rax, qword[rel saved_cr0]
+    mov      cr0, rax
+    mov      rax, qword[rel saved_cr4]
+    mov      cr4, rax
+    mov      rax, qword[rel saved_cr3]
+    mov      cr3, rax
+    lea      rax, qword[rel saved_gdt]
+    lgdt     [rax]
+    mov      rax, 0x18 ; FIXME: Magic number
+    mov      ds, rax
+    mov      es, rax
+    mov      fs, rax
+    mov      gs, rax
+    mov      ss, rax
+    ; FIXME: swtich to the right CS descriptor
+    jmp      AsmRelocateApMailBoxLoopStart
+align 16
+mailbox_address:
+    dq 0
+saved_cr0:
+    dq 0
+saved_cr3:
+    dq 0
+saved_cr4:
+    dq 0
+saved_gdt:
+    db 10 dup 0
 BITS 64
 AsmRelocateApMailBoxLoopEnd:
 
@@ -87,5 +131,7 @@ ASM_PFX(AsmGetRelocationMap):
     lea        rax, [AsmRelocateApMailBoxLoopStart]
     mov        qword [rcx], rax
     mov        qword [rcx +  8h], AsmRelocateApMailBoxLoopEnd - AsmRelocateApMailBoxLoopStart
+    lea        rax, [AsmRelocateApResetVector]
+    mov        qword [rcx + 10h], rax
     ret
 
-- 
2.41.0