UefiCpuPkg: Has APs in 64 bit long-mode before booting to OS.

During the finalization of Mp initialization before booting into the OS,
 depending on whether Mwait is supported or not, AsmRelocateApLoop
 places Aps in MWAIT-loop or HLT-loop.

Since paging is necessary for long mode, the original implementation of
moving APs to 32-bit was to disable paging to ensure that the booting
does not crash.

The current modification creates a page table in reserved memory,
avoiding switching modes and reclaiming memory by OS. This modification
is only for 64 bit mode.

More specifically, we keep the AMD logic as the original code flow,
extract and update the Intel-related code, where the APs would stay
in 64-bit, and run in a Mwait or Hlt loop until the OS wake them up.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>

1 files changed, 33 insertions, 51 deletions

diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
index 445e0853d2..beab06a5b1 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
@@ -28,6 +28,7 @@ volatile BOOLEAN  mStopCheckAllApsStatus       = TRUE;
 VOID              *mReservedApLoopFunc         = NULL;

 UINTN             mReservedTopOfApStack;

 volatile UINT32   mNumberToFinish = 0;

+UINTN             mApPageTable;

 

 //

 // Begin wakeup buffer allocation below 0x88000

@@ -407,12 +408,9 @@ RelocateApLoop (
     AsmRelocateApLoopFunc (

       MwaitSupport,

       CpuMpData->ApTargetCState,

-      CpuMpData->PmCodeSegment,

       StackStart - ProcessorNumber * AP_SAFE_STACK_SIZE,

       (UINTN)&mNumberToFinish,

-      CpuMpData->Pm16CodeSegment,

-      CpuMpData->SevEsAPBuffer,

-      CpuMpData->WakeupBuffer

+      mApPageTable

       );

   }

 

@@ -477,7 +475,6 @@ InitMpGlobalData (
   )

 {

   EFI_STATUS                       Status;

-  EFI_PHYSICAL_ADDRESS             Address;

   UINTN                            ApSafeBufferSize;

   UINTN                            Index;

   EFI_GCD_MEMORY_SPACE_DESCRIPTOR  MemDesc;

@@ -545,60 +542,45 @@ InitMpGlobalData (
   // Allocating it in advance since memory services are not available in

   // Exit Boot Services callback function.

   //

-  ApSafeBufferSize = EFI_PAGES_TO_SIZE (

-                       EFI_SIZE_TO_PAGES (

-                         CpuMpData->AddressMap.RelocateApLoopFuncSize

-                         )

-                       );

-  Address = BASE_4GB - 1;

-  Status  = gBS->AllocatePages (

-                   AllocateMaxAddress,

-                   EfiReservedMemoryType,

-                   EFI_SIZE_TO_PAGES (ApSafeBufferSize),

-                   &Address

-                   );

-  ASSERT_EFI_ERROR (Status);

-

-  mReservedApLoopFunc = (VOID *)(UINTN)Address;

-  ASSERT (mReservedApLoopFunc != NULL);

-

-  //

-  // Make sure that the buffer memory is executable if NX protection is enabled

-  // for EfiReservedMemoryType.

-  //

-  // TODO: Check EFI_MEMORY_XP bit set or not once it's available in DXE GCD

-  //       service.

+  // +------------+

+  // | Ap Loop    |

+  // +------------+

+  // | Stack * N  |

+  // +------------+ (low address)

   //

-  Status = gDS->GetMemorySpaceDescriptor (Address, &MemDesc);

-  if (!EFI_ERROR (Status)) {

-    gDS->SetMemorySpaceAttributes (

-           Address,

-           ApSafeBufferSize,

-           MemDesc.Attributes & (~EFI_MEMORY_XP)

-           );

-  }

-

   ApSafeBufferSize = EFI_PAGES_TO_SIZE (

                        EFI_SIZE_TO_PAGES (

                          CpuMpData->CpuCount * AP_SAFE_STACK_SIZE

+                         + CpuMpData->AddressMap.RelocateApLoopFuncSize

                          )

                        );

-  Address = BASE_4GB - 1;

-  Status  = gBS->AllocatePages (

-                   AllocateMaxAddress,

-                   EfiReservedMemoryType,

-                   EFI_SIZE_TO_PAGES (ApSafeBufferSize),

-                   &Address

-                   );

-  ASSERT_EFI_ERROR (Status);

 

-  mReservedTopOfApStack = (UINTN)Address + ApSafeBufferSize;

+  mReservedTopOfApStack = (UINTN)AllocateReservedPages (EFI_SIZE_TO_PAGES (ApSafeBufferSize));

+  ASSERT (mReservedTopOfApStack != 0);

   ASSERT ((mReservedTopOfApStack & (UINTN)(CPU_STACK_ALIGNMENT - 1)) == 0);

-  CopyMem (

-    mReservedApLoopFunc,

-    CpuMpData->AddressMap.RelocateApLoopFuncAddress,

-    CpuMpData->AddressMap.RelocateApLoopFuncSize

-    );

+  ASSERT ((AP_SAFE_STACK_SIZE & (CPU_STACK_ALIGNMENT - 1)) == 0);

+

+  mReservedApLoopFunc = (VOID *)(mReservedTopOfApStack + CpuMpData->CpuCount * AP_SAFE_STACK_SIZE);

+  if (StandardSignatureIsAuthenticAMD ()) {

+    CopyMem (

+      mReservedApLoopFunc,

+      CpuMpData->AddressMap.RelocateApLoopFuncAddressAmd,

+      CpuMpData->AddressMap.RelocateApLoopFuncSizeAmd

+      );

+  } else {

+    CopyMem (

+      mReservedApLoopFunc,

+      CpuMpData->AddressMap.RelocateApLoopFuncAddress,

+      CpuMpData->AddressMap.RelocateApLoopFuncSize

+      );

+

+    mApPageTable = CreatePageTable (

+                     mReservedTopOfApStack,

+                     ApSafeBufferSize

+                     );

+  }

+

+  mReservedTopOfApStack += CpuMpData->CpuCount * AP_SAFE_STACK_SIZE;

 

   Status = gBS->CreateEvent (

                   EVT_TIMER | EVT_NOTIFY_SIGNAL,