[PATCH v3 16/27] Ovmf/Xen: move XenBusDxe hypercall code to separate library

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

This moves all of the Xen hypercall code that was private to XenBusDxe
to a new library class XenHypercallLib. This will allow us to reimplement
it for ARM, and to export the Xen hypercall functionality to other parts
of the code, such as a Xen console SerialPortLib driver.

Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 .../Library/XenHypercallLib.h}                     | 16 +----
 .../XenHypercallLib}/Ia32/hypercall.nasm           |  0
 .../XenHypercallLib}/X64/hypercall.nasm            |  0
 .../XenHypercallLib}/XenHypercall.c                | 48 +-------------
 .../Library/XenHypercallLib/XenHypercallIntel.c    | 77 ++++++++++++++++++++++
 .../XenHypercallLib/XenHypercallLibIntel.inf       | 52 +++++++++++++++
 OvmfPkg/OvmfPkg.dec                                |  4 ++
 OvmfPkg/OvmfPkgIa32.dsc                            |  1 +
 OvmfPkg/OvmfPkgIa32X64.dsc                         |  1 +
 OvmfPkg/OvmfPkgX64.dsc                             |  1 +
 OvmfPkg/XenBusDxe/EventChannel.c                   |  3 +-
 OvmfPkg/XenBusDxe/GrantTable.c                     |  2 +-
 OvmfPkg/XenBusDxe/XenBusDxe.c                      |  9 +--
 OvmfPkg/XenBusDxe/XenBusDxe.inf                    | 11 +---
 OvmfPkg/XenBusDxe/XenStore.c                       |  2 +-
 15 files changed, 146 insertions(+), 81 deletions(-)
 rename OvmfPkg/{XenBusDxe/XenHypercall.h => Include/Library/XenHypercallLib.h} (82%)
 rename OvmfPkg/{XenBusDxe => Library/XenHypercallLib}/Ia32/hypercall.nasm (100%)
 rename OvmfPkg/{XenBusDxe => Library/XenHypercallLib}/X64/hypercall.nasm (100%)
 rename OvmfPkg/{XenBusDxe => Library/XenHypercallLib}/XenHypercall.c (60%)
 create mode 100644 OvmfPkg/Library/XenHypercallLib/XenHypercallIntel.c
 create mode 100644 OvmfPkg/Library/XenHypercallLib/XenHypercallLibIntel.inf

diff --git a/OvmfPkg/XenBusDxe/XenHypercall.h b/OvmfPkg/Include/Library/XenHypercallLib.h
similarity index 82%
rename from OvmfPkg/XenBusDxe/XenHypercall.h
rename to OvmfPkg/Include/Library/XenHypercallLib.h
index 9d49e33eb5af..7a170ff3b90e 100644
--- a/OvmfPkg/XenBusDxe/XenHypercall.h
+++ b/OvmfPkg/Include/Library/XenHypercallLib.h
@@ -13,8 +13,8 @@
 
 **/
 
-#ifndef __XENBUS_DXE_HYPERCALL_H__
-#define __XENBUS_DXE_HYPERCALL_H__
+#ifndef __XEN_HYPERCALL_LIB_H__
+#define __XEN_HYPERCALL_LIB_H__
 
 /**
   This function will put the two arguments in the right place (registers) and
@@ -35,18 +35,6 @@ XenHypercall2 (
   );
 
 /**
-  Get the page where all hypercall are from the XenInfo hob.
-
-  @param Dev    A XENBUS_DEVICE instance.
-
-  @retval EFI_NOT_FOUND   hyperpage could not be found.
-  @retval EFI_SUCCESS     Successfully retrieve the hyperpage pointer.
-**/
-EFI_STATUS
-XenHyperpageInit (
-  );
-
-/**
   Return the value of the HVM parameter Index.
 
   @param Index  The parameter to get, e.g. HVM_PARAM_STORE_EVTCHN.
diff --git a/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm b/OvmfPkg/Library/XenHypercallLib/Ia32/hypercall.nasm
similarity index 100%
rename from OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
rename to OvmfPkg/Library/XenHypercallLib/Ia32/hypercall.nasm
diff --git a/OvmfPkg/XenBusDxe/X64/hypercall.nasm b/OvmfPkg/Library/XenHypercallLib/X64/hypercall.nasm
similarity index 100%
rename from OvmfPkg/XenBusDxe/X64/hypercall.nasm
rename to OvmfPkg/Library/XenHypercallLib/X64/hypercall.nasm
diff --git a/OvmfPkg/XenBusDxe/XenHypercall.c b/OvmfPkg/Library/XenHypercallLib/XenHypercall.c
similarity index 60%
rename from OvmfPkg/XenBusDxe/XenHypercall.c
rename to OvmfPkg/Library/XenHypercallLib/XenHypercall.c
index 19c34bdd0cec..ecc757cf707c 100644
--- a/OvmfPkg/XenBusDxe/XenHypercall.c
+++ b/OvmfPkg/Library/XenHypercallLib/XenHypercall.c
@@ -14,43 +14,12 @@
 **/
 
 #include <PiDxe.h>
-#include <Library/HobLib.h>
-#include <Guid/XenInfo.h>
-
-#include "XenBusDxe.h"
-#include "XenHypercall.h"
 
 #include <IndustryStandard/Xen/hvm/params.h>
 #include <IndustryStandard/Xen/memory.h>
 
-STATIC VOID       *HyperPage;
-
-//
-// Interface exposed by the ASM implementation of the core hypercall
-//
-INTN
-EFIAPI
-__XenHypercall2 (
-  IN     VOID *HypercallAddr,
-  IN OUT INTN Arg1,
-  IN OUT INTN Arg2
-  );
-
-EFI_STATUS
-XenHyperpageInit (
-  )
-{
-  EFI_HOB_GUID_TYPE   *GuidHob;
-  EFI_XEN_INFO        *XenInfo;
-
-  GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);
-  if (GuidHob == NULL) {
-    return EFI_NOT_FOUND;
-  }
-  XenInfo = (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);
-  HyperPage = XenInfo->HyperPages;
-  return EFI_SUCCESS;
-}
+#include <Library/DebugLib.h>
+#include <Library/XenHypercallLib.h>
 
 UINT64
 XenHypercallHvmGetParam (
@@ -92,16 +61,3 @@ XenHypercallEventChannelOp (
   return XenHypercall2 (__HYPERVISOR_event_channel_op,
                         Operation, (INTN) Arguments);
 }
-
-INTN
-EFIAPI
-XenHypercall2 (
-  IN     INTN HypercallID,
-  IN OUT INTN Arg1,
-  IN OUT INTN Arg2
-  )
-{
-  ASSERT (HyperPage != NULL);
-
-  return __XenHypercall2 ((UINT8*)HyperPage + HypercallID * 32, Arg1, Arg2);
-}
diff --git a/OvmfPkg/Library/XenHypercallLib/XenHypercallIntel.c b/OvmfPkg/Library/XenHypercallLib/XenHypercallIntel.c
new file mode 100644
index 000000000000..362640f6a16f
--- /dev/null
+++ b/OvmfPkg/Library/XenHypercallLib/XenHypercallIntel.c
@@ -0,0 +1,77 @@
+/** @file
+  Xen Hypercall Library implementation for Intel architecture
+
+Copyright (c) 2014, Linaro Ltd. All rights reserved.<BR>
+This program and the accompanying materials are licensed and made available under
+the terms and conditions of the BSD License that 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/HobLib.h>
+#include <Library/DebugLib.h>
+#include <Guid/XenInfo.h>
+
+STATIC VOID    *HyperPage;
+
+//
+// Interface exposed by the ASM implementation of the core hypercall
+//
+INTN
+EFIAPI
+__XenHypercall2 (
+  IN     VOID *HypercallAddr,
+  IN OUT INTN Arg1,
+  IN OUT INTN Arg2
+  );
+
+/**
+  Library constructor: retrieves the Hyperpage address
+  from the gEfiXenInfoGuid HOB
+**/
+
+RETURN_STATUS
+EFIAPI
+XenHypercallLibIntelInit (
+  VOID
+  )
+{
+  EFI_HOB_GUID_TYPE   *GuidHob;
+  EFI_XEN_INFO        *XenInfo;
+
+  GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);
+  if (GuidHob == NULL) {
+    return RETURN_NOT_FOUND;
+  }
+  XenInfo = (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);
+  HyperPage = XenInfo->HyperPages;
+  return RETURN_SUCCESS;
+}
+
+/**
+  This function will put the two arguments in the right place (registers) and
+  invoke the hypercall identified by HypercallID.
+
+  @param HypercallID    The symbolic ID of the hypercall to be invoked
+  @param Arg1           First argument.
+  @param Arg2           Second argument.
+
+  @return   Return 0 if success otherwise it return an errno.
+**/
+INTN
+EFIAPI
+XenHypercall2 (
+  IN     INTN HypercallID,
+  IN OUT INTN Arg1,
+  IN OUT INTN Arg2
+  )
+{
+  ASSERT (HyperPage != NULL);
+
+  return __XenHypercall2 ((UINT8*)HyperPage + HypercallID * 32, Arg1, Arg2);
+}
diff --git a/OvmfPkg/Library/XenHypercallLib/XenHypercallLibIntel.inf b/OvmfPkg/Library/XenHypercallLib/XenHypercallLibIntel.inf
new file mode 100644
index 000000000000..2afd608f4a05
--- /dev/null
+++ b/OvmfPkg/Library/XenHypercallLib/XenHypercallLibIntel.inf
@@ -0,0 +1,52 @@
+## @file
+#  Xen Hypercall abstraction lib for Intel architecture
+#
+#  Copyright (c) 2014, Linaro Ltd. 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.
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = XenHypercallLibIntel
+  FILE_GUID                      = B5EE9A32-CA5A-49A8-82E3-ADA4CCB77C7C
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = XenHypercallLib|DXE_DRIVER UEFI_DRIVER
+  CONSTRUCTOR                    = XenHypercallLibIntelInit
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  XenHypercallIntel.c
+
+[Sources.IA32]
+  Ia32/hypercall.nasm
+
+[Sources.X64]
+  X64/hypercall.nasm
+
+[Sources]
+  XenHypercall.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  HobLib
+  DebugLib
+
+[Guids]
+  gEfiXenInfoGuid
diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index 6eb551a8d436..30a9fb1e9b42 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -44,6 +44,10 @@
   #
   SerializeVariablesLib|Include/Library/SerializeVariablesLib.h
 
+  ##  @libraryclass  Invoke Xen hypercalls
+  #
+  XenHypercallLib|Include/Library/XenHypercallLib.h
+
 [Guids]
   gUefiOvmfPkgTokenSpaceGuid      = {0x93bb96af, 0xb9f2, 0x4eb8, {0x94, 0x62, 0xe0, 0xba, 0x74, 0x56, 0x42, 0x36}}
   gEfiXenInfoGuid                 = {0xd3b46f3b, 0xd441, 0x1244, {0x9a, 0x12, 0x0, 0x12, 0x27, 0x3f, 0xc1, 0x4d}}
diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index ca656698754b..90540272745c 100644
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -128,6 +128,7 @@
   S3BootScriptLib|MdeModulePkg/Library/PiDxeS3BootScriptLib/DxeS3BootScriptLib.inf
   SmbusLib|MdePkg/Library/BaseSmbusLibNull/BaseSmbusLibNull.inf
   OrderedCollectionLib|MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.inf
+  XenHypercallLib|OvmfPkg/Library/XenHypercallLib/XenHypercallLibIntel.inf
 
 [LibraryClasses.common]
 !if $(SECURE_BOOT_ENABLE) == TRUE
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 4b4a1da717c1..0a331eda8be0 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -133,6 +133,7 @@
   S3BootScriptLib|MdeModulePkg/Library/PiDxeS3BootScriptLib/DxeS3BootScriptLib.inf
   SmbusLib|MdePkg/Library/BaseSmbusLibNull/BaseSmbusLibNull.inf
   OrderedCollectionLib|MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.inf
+  XenHypercallLib|OvmfPkg/Library/XenHypercallLib/XenHypercallLibIntel.inf
 
 [LibraryClasses.common]
 !if $(SECURE_BOOT_ENABLE) == TRUE
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index eb3f34b8350b..e2b37c271681 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -133,6 +133,7 @@
   S3BootScriptLib|MdeModulePkg/Library/PiDxeS3BootScriptLib/DxeS3BootScriptLib.inf
   SmbusLib|MdePkg/Library/BaseSmbusLibNull/BaseSmbusLibNull.inf
   OrderedCollectionLib|MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.inf
+  XenHypercallLib|OvmfPkg/Library/XenHypercallLib/XenHypercallLibIntel.inf
 
 [LibraryClasses.common]
 !if $(SECURE_BOOT_ENABLE) == TRUE
diff --git a/OvmfPkg/XenBusDxe/EventChannel.c b/OvmfPkg/XenBusDxe/EventChannel.c
index a86323e6adfd..6a36dca29911 100644
--- a/OvmfPkg/XenBusDxe/EventChannel.c
+++ b/OvmfPkg/XenBusDxe/EventChannel.c
@@ -16,7 +16,8 @@
 
 **/
 #include "EventChannel.h"
-#include "XenHypercall.h"
+
+#include <Library/XenHypercallLib.h>
 
 UINT32
 XenEventChannelNotify (
diff --git a/OvmfPkg/XenBusDxe/GrantTable.c b/OvmfPkg/XenBusDxe/GrantTable.c
index 53cb99f0e004..a80d5eff39cd 100644
--- a/OvmfPkg/XenBusDxe/GrantTable.c
+++ b/OvmfPkg/XenBusDxe/GrantTable.c
@@ -34,7 +34,7 @@
 
 #include <IndustryStandard/Xen/memory.h>
 
-#include "XenHypercall.h"
+#include <Library/XenHypercallLib.h>
 
 #include "GrantTable.h"
 #include "InterlockedCompareExchange16.h"
diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.c b/OvmfPkg/XenBusDxe/XenBusDxe.c
index d333b331b6db..cc334c086c1f 100644
--- a/OvmfPkg/XenBusDxe/XenBusDxe.c
+++ b/OvmfPkg/XenBusDxe/XenBusDxe.c
@@ -26,10 +26,10 @@
 #include <IndustryStandard/Pci.h>
 #include <IndustryStandard/Acpi.h>
 #include <Library/DebugLib.h>
+#include <Library/XenHypercallLib.h>
 
 #include "XenBusDxe.h"
 
-#include "XenHypercall.h"
 #include "GrantTable.h"
 #include "XenStore.h"
 #include "XenBus.h"
@@ -390,13 +390,6 @@ XenBusDxeDriverBindingStart (
   MmioAddr = BarDesc->AddrRangeMin;
   FreePool (BarDesc);
 
-  Status = XenHyperpageInit ();
-  if (EFI_ERROR (Status)) {
-    DEBUG ((EFI_D_ERROR, "XenBus: Unable to retrieve the hyperpage.\n"));
-    Status = EFI_UNSUPPORTED;
-    goto ErrorAllocated;
-  }
-
   Status = XenGetSharedInfoPage (Dev);
   if (EFI_ERROR (Status)) {
     DEBUG ((EFI_D_ERROR, "XenBus: Unable to get the shared info page.\n"));
diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.inf b/OvmfPkg/XenBusDxe/XenBusDxe.inf
index 4ce474345452..714607dbd6f8 100644
--- a/OvmfPkg/XenBusDxe/XenBusDxe.inf
+++ b/OvmfPkg/XenBusDxe/XenBusDxe.inf
@@ -34,8 +34,6 @@
   DriverBinding.h
   ComponentName.c
   ComponentName.h
-  XenHypercall.c
-  XenHypercall.h
   InterlockedCompareExchange16.c
   InterlockedCompareExchange16.h
   GrantTable.c
@@ -49,12 +47,10 @@
   Helpers.c
 
 [Sources.IA32]
-  Ia32/hypercall.nasm
   Ia32/InterlockedCompareExchange16.nasm
   Ia32/TestAndClearBit.nasm
 
 [Sources.X64]
-  X64/hypercall.nasm
   X64/InterlockedCompareExchange16.nasm
   X64/TestAndClearBit.nasm
 
@@ -67,8 +63,7 @@
   UefiLib
   DevicePathLib
   DebugLib
-  HobLib
-
+  XenHypercallLib
 
 [Protocols]
   gEfiDriverBindingProtocolGuid
@@ -77,7 +72,3 @@
   gEfiComponentNameProtocolGuid
   gXenBusProtocolGuid
 
-
-[Guids]
-  gEfiXenInfoGuid
-
diff --git a/OvmfPkg/XenBusDxe/XenStore.c b/OvmfPkg/XenBusDxe/XenStore.c
index 7ec1e634bc5c..9850f1e644fc 100644
--- a/OvmfPkg/XenBusDxe/XenStore.c
+++ b/OvmfPkg/XenBusDxe/XenStore.c
@@ -60,8 +60,8 @@
 
 #include <IndustryStandard/Xen/hvm/params.h>
 
-#include "XenHypercall.h"
 #include "EventChannel.h"
+#include <Library/XenHypercallLib.h>
 
 //
 // Private Data Structures
-- 
1.8.3.2