Re: [PATCH v3 1/5] UefiCpuPkg/SecCore: Migrate page table to permanent memory

["Ni, Ray" <ray.ni@intel.com>]

Reviewed-by: Ray Ni <ray.ni@intel.com>

________________________________________
From: Wu, Jiaxin <jiaxin.wu@intel.com>
Sent: Monday, May 15, 2023 10:15
To: devel@edk2.groups.io
Cc: Dong, Eric; Ni, Ray; Zeng, Star; Gerd Hoffmann; Kumar, Rahul R
Subject: [PATCH v3 1/5] UefiCpuPkg/SecCore: Migrate page table to permanent memory

Background:
For arch X64, system will enable the page table in SPI to cover 0-512G
range via CR4.PAE & MSR.LME & CR0.PG & CR3 setting (see ResetVector code).
Existing code doesn't cover the higher address access above 512G before
memory-discovered callback. That will be potential problem if system
access the higher address after the transition from temporary RAM to
permanent MEM RAM.

Solution:
This patch is to migrate page table to permanent memory to map entire physical
address space if CR0.PG is set during temporary RAM Done.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Zeng Star <star.zeng@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
---
 UefiCpuPkg/SecCore/SecCore.inf       |   1 +
 UefiCpuPkg/SecCore/SecCoreNative.inf |   1 +
 UefiCpuPkg/SecCore/SecMain.c         | 147 +++++++++++++++++++++++++++++++++++
 UefiCpuPkg/SecCore/SecMain.h         |   4 +
 4 files changed, 153 insertions(+)

diff --git a/UefiCpuPkg/SecCore/SecCore.inf b/UefiCpuPkg/SecCore/SecCore.inf
index 3758aded3b..cab69b8b97 100644
--- a/UefiCpuPkg/SecCore/SecCore.inf
+++ b/UefiCpuPkg/SecCore/SecCore.inf
@@ -53,10 +53,11 @@
   CpuExceptionHandlerLib
   ReportStatusCodeLib
   PeiServicesLib
   PeiServicesTablePointerLib
   HobLib
+  CpuPageTableLib

 [Ppis]
   ## SOMETIMES_CONSUMES
   ## PRODUCES
   gEfiSecPlatformInformationPpiGuid
diff --git a/UefiCpuPkg/SecCore/SecCoreNative.inf b/UefiCpuPkg/SecCore/SecCoreNative.inf
index 1ee6ff7d88..fa241cca94 100644
--- a/UefiCpuPkg/SecCore/SecCoreNative.inf
+++ b/UefiCpuPkg/SecCore/SecCoreNative.inf
@@ -50,10 +50,11 @@
   CpuExceptionHandlerLib
   ReportStatusCodeLib
   PeiServicesLib
   PeiServicesTablePointerLib
   HobLib
+  CpuPageTableLib

 [Ppis]
   ## SOMETIMES_CONSUMES
   ## PRODUCES
   gEfiSecPlatformInformationPpiGuid
diff --git a/UefiCpuPkg/SecCore/SecMain.c b/UefiCpuPkg/SecCore/SecMain.c
index 95375850ec..b0ab6cdae4 100644
--- a/UefiCpuPkg/SecCore/SecMain.c
+++ b/UefiCpuPkg/SecCore/SecMain.c
@@ -70,10 +70,139 @@ MigrateGdt (
   AsmWriteGdtr (&Gdtr);

   return EFI_SUCCESS;
 }

+/**
+  Migrate page table to permanent memory mapping entire physical address space.
+
+  @retval   EFI_SUCCESS           The PageTable was migrated successfully.
+  @retval   EFI_UNSUPPORTED       Unsupport to migrate page table to permanent memory if IA-32e Mode not actived.
+  @retval   EFI_OUT_OF_RESOURCES  The PageTable could not be migrated due to lack of available memory.
+
+**/
+EFI_STATUS
+MigratePageTable (
+  VOID
+  )
+{
+  EFI_STATUS                      Status;
+  IA32_CR4                        Cr4;
+  BOOLEAN                         Page5LevelSupport;
+  UINT32                          RegEax;
+  CPUID_EXTENDED_CPU_SIG_EDX      RegEdx;
+  BOOLEAN                         Page1GSupport;
+  PAGING_MODE                     PagingMode;
+  CPUID_VIR_PHY_ADDRESS_SIZE_EAX  VirPhyAddressSize;
+  UINT32                          MaxExtendedFunctionId;
+  UINTN                           PageTable;
+  EFI_PHYSICAL_ADDRESS            Buffer;
+  UINTN                           BufferSize;
+  IA32_MAP_ATTRIBUTE              MapAttribute;
+  IA32_MAP_ATTRIBUTE              MapMask;
+
+  VirPhyAddressSize.Uint32    = 0;
+  PageTable                   = 0;
+  BufferSize                  = 0;
+  MapAttribute.Uint64         = 0;
+  MapMask.Uint64              = MAX_UINT64;
+  MapAttribute.Bits.Present   = 1;
+  MapAttribute.Bits.ReadWrite = 1;
+
+  //
+  // Check Page5Level Support or not.
+  //
+  Cr4.UintN         = AsmReadCr4 ();
+  Page5LevelSupport = (Cr4.Bits.LA57 ? TRUE : FALSE);
+
+  //
+  // Check Page1G Support or not.
+  //
+  Page1GSupport = FALSE;
+  AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL);
+  if (RegEax >= CPUID_EXTENDED_CPU_SIG) {
+    AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &RegEdx.Uint32);
+    if (RegEdx.Bits.Page1GB != 0) {
+      Page1GSupport = TRUE;
+    }
+  }
+
+  //
+  // Decide Paging Mode according Page5LevelSupport & Page1GSupport.
+  //
+  if (Page5LevelSupport) {
+    PagingMode = Page1GSupport ? Paging5Level1GB : Paging5Level;
+  } else {
+    PagingMode = Page1GSupport ? Paging4Level1GB : Paging4Level;
+  }
+
+  //
+  // Get Maximum Physical Address Bits
+  // Get the number of address lines; Maximum Physical Address is 2^PhysicalAddressBits - 1.
+  // If CPUID does not supported, then use a max value of 36 as per SDM 3A, 4.1.4.
+  //
+  AsmCpuid (CPUID_EXTENDED_FUNCTION, &MaxExtendedFunctionId, NULL, NULL, NULL);
+  if (MaxExtendedFunctionId >= CPUID_VIR_PHY_ADDRESS_SIZE) {
+    AsmCpuid (CPUID_VIR_PHY_ADDRESS_SIZE, &VirPhyAddressSize.Uint32, NULL, NULL, NULL);
+  } else {
+    VirPhyAddressSize.Bits.PhysicalAddressBits = 36;
+  }
+
+  if ((PagingMode == Paging4Level1GB) || (PagingMode == Paging4Level)) {
+    //
+    // The max lineaddress bits is 48 for 4 level page table.
+    //
+    VirPhyAddressSize.Bits.PhysicalAddressBits = MIN (VirPhyAddressSize.Bits.PhysicalAddressBits, 48);
+  }
+
+  //
+  // Get required buffer size for the pagetable that will be created.
+  //
+  Status = PageTableMap (&PageTable, PagingMode, 0, &BufferSize, 0, LShiftU64 (1, VirPhyAddressSize.Bits.PhysicalAddressBits), &MapAttribute, &MapMask, NULL);
+  ASSERT (Status == EFI_BUFFER_TOO_SMALL);
+  if (Status != EFI_BUFFER_TOO_SMALL) {
+    return Status;
+  }
+
+  //
+  // Allocate required Buffer.
+  //
+  Status = PeiServicesAllocatePages (
+             EfiBootServicesData,
+             EFI_SIZE_TO_PAGES (BufferSize),
+             &Buffer
+             );
+  if (EFI_ERROR (Status)) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  //
+  // Create PageTable in permanent memory.
+  //
+  Status = PageTableMap (&PageTable, PagingMode, (VOID *)(UINTN)Buffer, &BufferSize, 0, LShiftU64 (1, VirPhyAddressSize.Bits.PhysicalAddressBits), &MapAttribute, &MapMask, NULL);
+  ASSERT_EFI_ERROR (Status);
+  if (EFI_ERROR (Status) || (PageTable == 0)) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  //
+  // Write the Pagetable to CR3.
+  //
+  AsmWriteCr3 (PageTable);
+
+  DEBUG ((
+    DEBUG_INFO,
+    "MigratePageTable: Created PageTable = 0x%lx, BufferSize = %x, PagingMode = 0x%lx, Support Max Physical Address Bits = %d\n",
+    PageTable,
+    BufferSize,
+    (UINTN)PagingMode,
+    VirPhyAddressSize.Bits.PhysicalAddressBits
+    ));
+
+  return Status;
+}
+
 //
 // These are IDT entries pointing to 10:FFFFFFE4h.
 //
 UINT64  mIdtEntryTemplate = 0xffff8e000010ffe4ULL;

@@ -451,10 +580,11 @@ SecTemporaryRamDone (
   EFI_STATUS              Status2;
   UINTN                   Index;
   BOOLEAN                 State;
   EFI_PEI_PPI_DESCRIPTOR  *PeiPpiDescriptor;
   REPUBLISH_SEC_PPI_PPI   *RepublishSecPpiPpi;
+  IA32_CR0                Cr0;

   //
   // Republish Sec Platform Information(2) PPI
   //
   RepublishSecPlatformInformationPpi ();
@@ -492,10 +622,27 @@ SecTemporaryRamDone (
   if (PcdGetBool (PcdMigrateTemporaryRamFirmwareVolumes)) {
     Status = MigrateGdt ();
     ASSERT_EFI_ERROR (Status);
   }

+  //
+  // Migrate page table to permanent memory mapping entire physical address space if CR0.PG is set.
+  //
+  Cr0.UintN = AsmReadCr0 ();
+  if (Cr0.Bits.PG != 0) {
+    //
+    // Assume CPU runs in 64bit mode if paging is enabled.
+    //
+    ASSERT (sizeof (UINTN) == sizeof (UINT64));
+
+    Status = MigratePageTable ();
+    if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_ERROR, "SecTemporaryRamDone: Failed to migrate page table to permanent memory: %r.\n", Status));
+      CpuDeadLoop ();
+    }
+  }
+
   //
   // Disable Temporary RAM after Stack and Heap have been migrated at this point.
   //
   SecPlatformDisableTemporaryMemory ();

diff --git a/UefiCpuPkg/SecCore/SecMain.h b/UefiCpuPkg/SecCore/SecMain.h
index 880e6cd1b8..b50d96e45b 100644
--- a/UefiCpuPkg/SecCore/SecMain.h
+++ b/UefiCpuPkg/SecCore/SecMain.h
@@ -17,10 +17,11 @@
 #include <Ppi/PeiCoreFvLocation.h>
 #include <Ppi/RepublishSecPpi.h>

 #include <Guid/FirmwarePerformance.h>

+#include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
 #include <Library/PcdLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/PlatformSecLib.h>
 #include <Library/CpuLib.h>
@@ -30,10 +31,13 @@
 #include <Library/CpuExceptionHandlerLib.h>
 #include <Library/ReportStatusCodeLib.h>
 #include <Library/PeiServicesTablePointerLib.h>
 #include <Library/HobLib.h>
 #include <Library/PeiServicesLib.h>
+#include <Library/CpuPageTableLib.h>
+#include <Register/Intel/Cpuid.h>
+#include <Register/Intel/Msr.h>

 #define SEC_IDT_ENTRY_COUNT  34

 typedef struct _SEC_IDT_TABLE {
   //
--
2.16.2.windows.1