[PATCH v4 33/35] OvmfPkg: Introduce XenIoPvhDxe to initialize Grant Tables

["Anthony PERARD" <anthony.perard@citrix.com>]

XenIoPvhDxe use XenIoMmioLib to reserve some space to be use by the
Grant Tables.

The call is only done if it is necessary, we simply detect if the
guest is PVH, as in this case there is currently no PCI bus, and no
PCI Xen platform device which would start the XenIoPciDxe and allocate
the space for the Grant Tables.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---

Notes:
    v4:
    - Removed XenIoPvhDxeNotifyExitBoot() which was doing action that should
      not be done in an ExitBootServices notification.
      (InitializeXenIoPvhDxe() has been cleaned up following this.)
    - Use new PcdXenGrantFrames.
    - Some coding style fix
    - Update Maintainers.txt
    
    v3:
    - downgrade type to DXE_DRIVER
    - use SPDX
    - rework InitializeXenIoPvhDxe, and handle errors properly.
    - Free the reserved allocation in ExitBootServices even if the XenIo
      protocol could successfully been uninstalled.
    
    v2:
    - do allocation in EntryPoint like the other user of XenIoMmioLib.
    - allocate memory instead of hardcoded addr.
    - cleanup, add copyright
    - detect if we are running in PVH mode

 OvmfPkg/OvmfXen.dsc                 |  2 ++
 OvmfPkg/OvmfXen.fdf                 |  1 +
 OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf | 35 +++++++++++++++++++
 OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c   | 53 +++++++++++++++++++++++++++++
 Maintainers.txt                     |  1 +
 5 files changed, 92 insertions(+)
 create mode 100644 OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
 create mode 100644 OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c

diff --git a/OvmfPkg/OvmfXen.dsc b/OvmfPkg/OvmfXen.dsc
index e719a168f8..5e07b37279 100644
--- a/OvmfPkg/OvmfXen.dsc
+++ b/OvmfPkg/OvmfXen.dsc
@@ -195,6 +195,7 @@ [LibraryClasses]
   OrderedCollectionLib|MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.inf
   XenHypercallLib|OvmfPkg/Library/XenHypercallLib/XenHypercallLib.inf
   XenPlatformLib|OvmfPkg/Library/XenPlatformLib/XenPlatformLib.inf
+  XenIoMmioLib|OvmfPkg/Library/XenIoMmioLib/XenIoMmioLib.inf
 
   Tcg2PhysicalPresenceLib|OvmfPkg/Library/Tcg2PhysicalPresenceLibNull/DxeTcg2PhysicalPresenceLib.inf
   TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
@@ -583,6 +584,7 @@ [Components]
       NULL|OvmfPkg/Csm/LegacyBootMaintUiLib/LegacyBootMaintUiLib.inf
 !endif
   }
+  OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
   OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf
   OvmfPkg/XenBusDxe/XenBusDxe.inf
   OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
diff --git a/OvmfPkg/OvmfXen.fdf b/OvmfPkg/OvmfXen.fdf
index 5c1a925d6a..517a492f14 100644
--- a/OvmfPkg/OvmfXen.fdf
+++ b/OvmfPkg/OvmfXen.fdf
@@ -309,6 +309,7 @@ [FV.DXEFV]
 INF  MdeModulePkg/Universal/Metronome/Metronome.inf
 INF  PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntimeDxe.inf
 
+INF  OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
 INF  OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf
 INF  OvmfPkg/XenBusDxe/XenBusDxe.inf
 INF  OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
diff --git a/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf b/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
new file mode 100644
index 0000000000..5740df6e59
--- /dev/null
+++ b/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
@@ -0,0 +1,35 @@
+## @file
+#  Driver for the XenIo protocol
+#
+#  Copyright (c) 2019, Citrix Systems, Inc.
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION               = 0x00010005
+  BASE_NAME                 = XenIoPvhDxe
+  FILE_GUID                 = 7a567cc4-0e75-4d7a-a305-c3db109b53ad
+  MODULE_TYPE               = DXE_DRIVER
+  VERSION_STRING            = 1.0
+  ENTRY_POINT               = InitializeXenIoPvhDxe
+
+[Packages]
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[Sources]
+  XenIoPvhDxe.c
+
+[LibraryClasses]
+  MemoryAllocationLib
+  UefiDriverEntryPoint
+  XenIoMmioLib
+  XenPlatformLib
+
+[FixedPcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdXenGrantFrames
+
+[Depex]
+  TRUE
diff --git a/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c b/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c
new file mode 100644
index 0000000000..e5699cdd80
--- /dev/null
+++ b/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c
@@ -0,0 +1,53 @@
+/** @file
+
+  Driver for the XenIo protocol
+
+  This driver simply allocate space for the grant tables.
+
+  Copyright (c) 2019, Citrix Systems, Inc.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/MemoryAllocationLib.h>
+#include <Library/XenIoMmioLib.h>
+#include <Library/XenPlatformLib.h>
+
+EFI_STATUS
+EFIAPI
+InitializeXenIoPvhDxe (
+  IN EFI_HANDLE       ImageHandle,
+  IN EFI_SYSTEM_TABLE *SystemTable
+  )
+{
+  VOID          *Allocation;
+  EFI_STATUS    Status;
+  EFI_HANDLE    XenIoHandle;
+
+  Allocation = NULL;
+  XenIoHandle = NULL;
+
+  if (!XenPvhDetected ()) {
+    return EFI_UNSUPPORTED;
+  }
+
+  Allocation = AllocateReservedPages (FixedPcdGet32 (PcdXenGrantFrames));
+  if (Allocation == NULL) {
+    Status = EFI_OUT_OF_RESOURCES;
+    goto Error;
+  }
+
+  Status = XenIoMmioInstall (&XenIoHandle, (UINTN) Allocation);
+  if (EFI_ERROR (Status)) {
+    goto Error;
+  }
+
+  return EFI_SUCCESS;
+
+Error:
+  if (Allocation != NULL) {
+    FreePages (Allocation, FixedPcdGet32 (PcdXenGrantFrames));
+  }
+  return Status;
+}
diff --git a/Maintainers.txt b/Maintainers.txt
index 78e9f889ab..79defd13bf 100644
--- a/Maintainers.txt
+++ b/Maintainers.txt
@@ -382,6 +382,7 @@ F: OvmfPkg/PlatformPei/Xen.*
 F: OvmfPkg/SmbiosPlatformDxe/*Xen.c
 F: OvmfPkg/XenBusDxe/
 F: OvmfPkg/XenIoPciDxe/
+F: OvmfPkg/XenIoPvhDxe/
 F: OvmfPkg/XenPlatformPei/
 F: OvmfPkg/XenPvBlkDxe/
 F: OvmfPkg/XenResetVector/
-- 
Anthony PERARD