[RFC PATCH v1 25/30] ArmVirtPkg: Add ArmCcaDxe for early DXE phase initialisation

["Sami Mujawar" <sami.mujawar@arm.com>]

Add ArmCcaDxe for early DXE phase initialisation like setting
up the monitor call conduit for Realm code

The Realm code should use SMC as the conduit for monitor calls.
Therefore, set the PcdMonitorConduitHvc to FALSE if the code is
running in a Realm.

Note: ArmCcaDxe is configured as an APRIORI DXE so that the DXE
dispatcher can schedule this to be loaded at the very beginning
of the Dxe phase. The DevicePathDxe.inf and Pcd.inf modules have
also been included to satisfy the required dependencies.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
---
 ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.c   | 50 ++++++++++++++++++++
 ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.inf | 39 +++++++++++++++
 ArmVirtPkg/ArmVirtKvmTool.dsc      |  5 +-
 ArmVirtPkg/ArmVirtKvmTool.fdf      | 10 ++++
 4 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.c b/ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.c
new file mode 100644
index 0000000000000000000000000000000000000000..36a74f2521d2d92d404c42e86d5d37dd31a1972d
--- /dev/null
+++ b/ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.c
@@ -0,0 +1,50 @@
+/** @file
+  ArmCcaDxe
+
+  Copyright (c) 2022 - 2023, ARM Ltd. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Library/ArmCcaLib.h>
+#include <Library/ArmCcaRsiLib.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/HobLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/PcdLib.h>
+#include <Library/DebugLib.h>
+
+/** Entrypoint of Arm CCA Dxe.
+
+  @param [in] ImageHandle   Image handle of this driver.
+  @param [in] SystemTable   Pointer to the EFI System Table.
+
+  @retval RETURN_SUCCESS               Success.
+  @retval EFI_NOT_FOUND                Required HOB not found.
+**/
+EFI_STATUS
+EFIAPI
+ArmCcaDxe (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS  Status;
+
+  if (!IsRealm ()) {
+    // Nothing to do here, return SUCCESS.
+    return EFI_SUCCESS;
+  }
+
+  // Setup the conduit to be used by Realm code to SMC.
+  Status = PcdSetBoolS (PcdMonitorConduitHvc, FALSE);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "ERROR - Failed to set PcdMonitorConduitHvc\n"));
+    ASSERT (0);
+    return Status;
+  }
+
+  return Status;
+}
diff --git a/ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.inf b/ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.inf
new file mode 100644
index 0000000000000000000000000000000000000000..df110ae54ce54f792fe9cf9420334dd1e6a3fc2c
--- /dev/null
+++ b/ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.inf
@@ -0,0 +1,39 @@
+## @file
+#  ArmCcaDxe
+#
+#  Copyright (c) 2022 - 2023, Arm Limited. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x0001001B
+  BASE_NAME                      = ArmCcaDxe
+  FILE_GUID                      = 6E474F73-7D50-46A8-9AEB-996B71599FE9
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = ArmCcaDxe
+
+[Sources]
+  ArmCcaDxe.c
+
+[LibraryClasses]
+  ArmCcaLib
+  BaseLib
+  DebugLib
+  HobLib
+  PcdLib
+  UefiDriverEntryPoint
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  ArmVirtPkg/ArmVirtPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+
+[Pcd]
+  gArmTokenSpaceGuid.PcdMonitorConduitHvc
+
+[Depex]
+  TRUE
diff --git a/ArmVirtPkg/ArmVirtKvmTool.dsc b/ArmVirtPkg/ArmVirtKvmTool.dsc
index 9bc857ea88d00431bf4223f588f908eab7561a19..acf4ede48da2d33d50b5593a857f3815f427707c 100644
--- a/ArmVirtPkg/ArmVirtKvmTool.dsc
+++ b/ArmVirtPkg/ArmVirtKvmTool.dsc
@@ -404,9 +404,10 @@ [Components.common]
   #
   SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf
 
-!if $(ARCH) == AARCH64
+[Components.AARCH64]
   #
   # ACPI Support
   #
   ArmVirtPkg/KvmtoolCfgMgrDxe/ConfigurationManagerDxe.inf
-!endif
+
+  ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.inf
diff --git a/ArmVirtPkg/ArmVirtKvmTool.fdf b/ArmVirtPkg/ArmVirtKvmTool.fdf
index 8ccbccd71e134e0ea97d49380293687aca43e8b9..68bd0e9d82dc83a337d8127a598018381888d894 100644
--- a/ArmVirtPkg/ArmVirtKvmTool.fdf
+++ b/ArmVirtPkg/ArmVirtKvmTool.fdf
@@ -117,6 +117,16 @@ [FV.FvMain]
 READ_LOCK_CAP      = TRUE
 READ_LOCK_STATUS   = TRUE
 
+!if $(ARCH) == AARCH64
+  APRIORI DXE {
+    INF  MdeModulePkg/Universal/DevicePathDxe/DevicePathDxe.inf
+    INF  MdeModulePkg/Universal/PCD/Dxe/Pcd.inf
+    INF  ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.inf
+  }
+
+  INF ArmVirtPkg/ArmCcaDxe/ArmCcaDxe.inf
+!endif
+
   INF MdeModulePkg/Core/Dxe/DxeMain.inf
   INF MdeModulePkg/Universal/PCD/Dxe/Pcd.inf
   INF OvmfPkg/Fdt/VirtioFdtDxe/VirtioFdtDxe.inf
-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'