ArmVirtPkg/HighMemDxe: use CPU arch protocol to apply memprotect policy

[mirror_edk2.git] / ArmVirtPkg / HighMemDxe / HighMemDxe.c

/** @file\r
*  High memory node enumeration DXE driver for ARM Virtual Machines\r
*\r
*  Copyright (c) 2015-2016, Linaro Ltd. All rights reserved.\r
*\r
*  This program and the accompanying materials are licensed and made available\r
*  under the terms and conditions of the BSD License which accompanies this\r
*  distribution.  The full text of the license may be found at\r
*  http://opensource.org/licenses/bsd-license.php\r
*\r
*  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
*  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR\r
*  IMPLIED.\r
*\r
**/\r
\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/DxeServicesTableLib.h>\r
#include <Library/PcdLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
\r
#include <Protocol/Cpu.h>\r
#include <Protocol/FdtClient.h>\r
\r
EFI_STATUS\r
EFIAPI\r
InitializeHighMemDxe (\r
  IN EFI_HANDLE           ImageHandle,\r
  IN EFI_SYSTEM_TABLE     *SystemTable\r
  )\r
{\r
  FDT_CLIENT_PROTOCOL   *FdtClient;\r
  EFI_CPU_ARCH_PROTOCOL *Cpu;\r
  EFI_STATUS            Status, FindNodeStatus;\r
  INT32                 Node;\r
  CONST UINT32          *Reg;\r
  UINT32                RegSize;\r
  UINTN                 AddressCells, SizeCells;\r
  UINT64                CurBase;\r
  UINT64                CurSize;\r
  UINT64                Attributes;\r
\r
  Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,\r
                  (VOID **)&FdtClient);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL,\r
                  (VOID **)&Cpu);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Check for memory node and add the memory spaces except the lowest one\r
  //\r
  for (FindNodeStatus = FdtClient->FindMemoryNodeReg (FdtClient, &Node,\r
                                     (CONST VOID **) &Reg, &AddressCells,\r
                                     &SizeCells, &RegSize);\r
       !EFI_ERROR (FindNodeStatus);\r
       FindNodeStatus = FdtClient->FindNextMemoryNodeReg (FdtClient, Node,\r
                                     &Node, (CONST VOID **) &Reg, &AddressCells,\r
                                     &SizeCells, &RegSize)) {\r
    ASSERT (AddressCells <= 2);\r
    ASSERT (SizeCells <= 2);\r
\r
    while (RegSize > 0) {\r
      CurBase = SwapBytes32 (*Reg++);\r
      if (AddressCells > 1) {\r
        CurBase = (CurBase << 32) | SwapBytes32 (*Reg++);\r
      }\r
      CurSize = SwapBytes32 (*Reg++);\r
      if (SizeCells > 1) {\r
        CurSize = (CurSize << 32) | SwapBytes32 (*Reg++);\r
      }\r
      RegSize -= (AddressCells + SizeCells) * sizeof (UINT32);\r
\r
      if (PcdGet64 (PcdSystemMemoryBase) != CurBase) {\r
        Status = gDS->AddMemorySpace (EfiGcdMemoryTypeSystemMemory, CurBase,\r
                        CurSize, EFI_MEMORY_WB);\r
\r
        if (EFI_ERROR (Status)) {\r
          DEBUG ((EFI_D_ERROR,\r
            "%a: Failed to add System RAM @ 0x%lx - 0x%lx (%r)\n",\r
            __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));\r
          continue;\r
        }\r
\r
        Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize,\r
                        EFI_MEMORY_WB);\r
        if (EFI_ERROR (Status)) {\r
          DEBUG ((DEBUG_WARN,\r
            "%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n",\r
            __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));\r
        }\r
\r
        //\r
        // Due to the ambiguous nature of the RO/XP GCD memory space attributes,\r
        // it is impossible to add a memory space with the XP attribute in a way\r
        // that does not result in the XP attribute being set on *all* UEFI\r
        // memory map entries that are carved from it, including code regions\r
        // that require executable permissions.\r
        //\r
        // So instead, we never set the RO/XP attributes in the GCD memory space\r
        // capabilities or attribute fields, and apply any protections directly\r
        // on the page table mappings by going through the cpu arch protocol.\r
        //\r
        Attributes = EFI_MEMORY_WB;\r
        if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) &\r
             (1U << (UINT32)EfiConventionalMemory)) != 0) {\r
          Attributes |= EFI_MEMORY_XP;\r
        }\r
\r
        Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes);\r
\r
        if (EFI_ERROR (Status)) {\r
          DEBUG ((EFI_D_ERROR,\r
            "%a: Failed to set System RAM @ 0x%lx - 0x%lx attribute (%r)\n",\r
            __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));\r
        } else {\r
          DEBUG ((EFI_D_INFO, "%a: Add System RAM @ 0x%lx - 0x%lx\n",\r
            __FUNCTION__, CurBase, CurBase + CurSize - 1));\r
        }\r
      }\r
    }\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r