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 are licensed and made available
   9   under the terms and conditions of the BSD License which accompanies this
  10   distribution.  The full text of the license may be found at
  11   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 "AmdSevIoMmu.h"
  19
  20 EFI_STATUS
  21 EFIAPI
  22 IoMmuDxeEntryPoint (
  23   IN EFI_HANDLE         ImageHandle,
  24   IN EFI_SYSTEM_TABLE   *SystemTable
  25   )
  26 {
  27   EFI_STATUS    Status;
  28   EFI_HANDLE    Handle;
  29
  30   //
  31   // When SEV is enabled, install IoMmu protocol otherwise install the
  32   // placeholder protocol so that other dependent module can run.
  33   //
  34   if (MemEncryptSevIsEnabled ()) {
  35     Status = AmdSevInstallIoMmuProtocol ();
  36   } else {
  37     Handle = NULL;
  38
  39     Status = gBS->InstallMultipleProtocolInterfaces (
  40                   &Handle,
  41                   &gIoMmuAbsentProtocolGuid,
  42                   NULL, NULL);
  43   }
  44
  45   return Status;
  46 }