f9d129e68a
The IOMMU protocol driver provides capabilities to set a DMA access attribute and methods to allocate, free, map and unmap the DMA memory for the PCI Bus devices. Due to security reasons all DMA operations inside the SEV guest must be performed on shared (i.e unencrypted) pages. The IOMMU protocol driver for the SEV guest uses a bounce buffer to map guest DMA buffer to shared pages inorder to provide the support for DMA operations inside SEV guest. IoMmuDxe driver looks for SEV capabilities, if present then it installs the real IOMMU protocol otherwise it installs placeholder protocol. Currently, PciHostBridgeDxe and QemuFWCfgLib need to know the existance of IOMMU protocol. The modules needing to know the existance of IOMMU support should add gEdkiiIoMmuProtocolGuid OR gIoMmuAbsentProtocolGuid in their depex to ensure that platform IOMMU detection has been performed. Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Leo Duran <leo.duran@amd.com> Cc: Jiewen Yao <jiewen.yao@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Suggested-by: Jiewen Yao <jiewen.yao@intel.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Jiewen Yao <jiewen.yao@intel.com> Acked-by: Laszlo Ersek <lersek@redhat.com> Acked-by: Jordan Justen <jordan.l.justen@intel.com>
54 lines
1.5 KiB
C
54 lines
1.5 KiB
C
/** @file
|
|
|
|
IoMmuDxe driver installs EDKII_IOMMU_PROTOCOL to provide the support for DMA
|
|
operations when SEV is enabled.
|
|
|
|
Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
|
|
|
|
This program and the accompanying materials
|
|
are licensed and made available under the terms and conditions of the BSD
|
|
License which accompanies this distribution. The full text of the license may
|
|
be found at http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
|
|
**/
|
|
|
|
#include <PiDxe.h>
|
|
|
|
#include <Library/BaseLib.h>
|
|
#include <Library/DebugLib.h>
|
|
#include <Library/BaseMemoryLib.h>
|
|
#include <Library/MemoryAllocationLib.h>
|
|
#include <Library/UefiBootServicesTableLib.h>
|
|
#include <Library/MemEncryptSevLib.h>
|
|
|
|
#include "AmdSevIoMmu.h"
|
|
|
|
EFI_STATUS
|
|
EFIAPI
|
|
IoMmuDxeEntryPoint (
|
|
IN EFI_HANDLE ImageHandle,
|
|
IN EFI_SYSTEM_TABLE *SystemTable
|
|
)
|
|
{
|
|
EFI_STATUS Status = EFI_SUCCESS;
|
|
EFI_HANDLE Handle = NULL;
|
|
|
|
//
|
|
// When SEV is enabled, install IoMmu protocol otherwise install the
|
|
// placeholder protocol so that other dependent module can run.
|
|
//
|
|
if (MemEncryptSevIsEnabled ()) {
|
|
AmdSevInstallIoMmuProtocol ();
|
|
} else {
|
|
Status = gBS->InstallMultipleProtocolInterfaces (
|
|
&Handle,
|
|
&gIoMmuAbsentProtocolGuid,
|
|
NULL, NULL);
|
|
}
|
|
|
|
return Status;
|
|
}
|