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   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include "AmdSevIoMmu.h"
  13
  14 EFI_STATUS
  15 EFIAPI
  16 IoMmuDxeEntryPoint (
  17   IN EFI_HANDLE         ImageHandle,
  18   IN EFI_SYSTEM_TABLE   *SystemTable
  19   )
  20 {
  21   EFI_STATUS    Status;
  22   EFI_HANDLE    Handle;
  23
  24   //
  25   // When SEV is enabled, install IoMmu protocol otherwise install the
  26   // placeholder protocol so that other dependent module can run.
  27   //
  28   if (MemEncryptSevIsEnabled ()) {
  29     Status = AmdSevInstallIoMmuProtocol ();
  30   } else {
  31     Handle = NULL;
  32
  33     Status = gBS->InstallMultipleProtocolInterfaces (
  34                   &Handle,
  35                   &gIoMmuAbsentProtocolGuid,
  36                   NULL, NULL);
  37   }
  38
  39   return Status;
  40 }