OvmfPkg/IoMmuDxe/IoMmuDxe.c

   1 /** @file
   2
   3   IoMmuDxe driver installs EDKII_IOMMU_PROTOCOL to provide the support for DMA
   4   operations when SEV is enabled.
   5
   6   Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
   7
   8   This program and the accompanying materials
   9   are licensed and made available under the terms and conditions of the BSD
  10   License which accompanies this distribution.  The full text of the license may
  11   be found at http://opensource.org/licenses/bsd-license.php
  12
  13   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15
  16 **/
  17
  18 #include <PiDxe.h>
  19
  20 #include <Library/BaseLib.h>
  21 #include <Library/DebugLib.h>
  22 #include <Library/BaseMemoryLib.h>
  23 #include <Library/MemoryAllocationLib.h>
  24 #include <Library/UefiBootServicesTableLib.h>
  25 #include <Library/MemEncryptSevLib.h>
  26
  27 #include "AmdSevIoMmu.h"
  28
  29 EFI_STATUS
  30 EFIAPI
  31 IoMmuDxeEntryPoint (
  32   IN EFI_HANDLE         ImageHandle,
  33   IN EFI_SYSTEM_TABLE   *SystemTable
  34   )
  35 {
  36   EFI_STATUS    Status = EFI_SUCCESS;
  37   EFI_HANDLE    Handle = NULL;
  38
  39   //
  40   // When SEV is enabled, install IoMmu protocol otherwise install the
  41   // placeholder protocol so that other dependent module can run.
  42   //
  43   if (MemEncryptSevIsEnabled ()) {
  44     AmdSevInstallIoMmuProtocol ();
  45   } else {
  46     Status = gBS->InstallMultipleProtocolInterfaces (
  47                   &Handle,
  48                   &gIoMmuAbsentProtocolGuid,
  49                   NULL, NULL);
  50   }
  51
  52   return Status;
  53 }