OvmfPkg/Xen: export search of RSDP into a library function

Xen and bhyve are placing ACPI tables into system memory. So, they can
share the same code. Therefore, create a new library which searches and
installs ACPI tables from system memory.

Signed-off-by: Corvin Köhne <corvink@FreeBSD.org>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

OvmfPkg/Include/Library/AcpiPlatformLib.h

@@ -0,0 +1,24 @@
+/** @file
+  Copyright (c) 2023, Corvin Köhne <corvink@FreeBSD.org>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+/**
+  Searches and returns the address of the ACPI Root System Description Pointer (RSDP) in system memory.
+
+  @param  StartAddress        Start address of search range.
+  @param  EndAddress          End address of search range.
+  @param  RsdpPtr             Return pointer to RSDP.
+
+  @retval EFI_SUCCESS         RSDP successfully found.
+  @retval EFI_NOT_FOUND       Couldn't find RSDP.
+  @retval EFI_ABORTED         Invalid RSDP found.
+**/
+EFI_STATUS
+EFIAPI
+GetAcpiRsdpFromMemory (
+  IN UINT64                                         StartAddress,
+  IN UINT64                                         EndAddress,
+  OUT EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  **RsdpPtr
+  );

OvmfPkg/Library/AcpiPlatformLib/DxeAcpiPlatformLib.c

@@ -0,0 +1,67 @@
+/** @file
+  OVMF ACPI support
+
+  Copyright (C) 2021, Red Hat, Inc.
+  Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2012, Bei Guan <gbtju85@gmail.com>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/AcpiPlatformLib.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+
+EFI_STATUS
+EFIAPI
+GetAcpiRsdpFromMemory (
+  IN UINTN                                            StartAddress,
+  IN UINTN                                            EndAddress,
+  OUT   EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  **RsdpPtr
+  )
+{
+  EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *RsdpStructurePtr;
+  UINT8                                         *AcpiPtr;
+  UINT8                                         Sum;
+
+  for (AcpiPtr = (UINT8 *)StartAddress;
+       AcpiPtr < (UINT8 *)EndAddress;
+       AcpiPtr += 0x10)
+  {
+    RsdpStructurePtr = (EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER *)
+                       (UINTN)AcpiPtr;
+
+    if (!AsciiStrnCmp ((CHAR8 *)&RsdpStructurePtr->Signature, "RSD PTR ", 8)) {
+      //
+      // RSDP ACPI 1.0 checksum for 1.0/2.0/3.0 table.
+      // This is only the first 20 bytes of the structure
+      //
+      Sum = CalculateSum8 (
+              (CONST UINT8 *)RsdpStructurePtr,
+              sizeof (EFI_ACPI_1_0_ROOT_SYSTEM_DESCRIPTION_POINTER)
+              );
+      if (Sum != 0) {
+        return EFI_ABORTED;
+      }
+
+      if (RsdpStructurePtr->Revision >= 2) {
+        //
+        // RSDP ACPI 2.0/3.0 checksum, this is the entire table
+        //
+        Sum = CalculateSum8 (
+                (CONST UINT8 *)RsdpStructurePtr,
+                sizeof (EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER)
+                );
+        if (Sum != 0) {
+          return EFI_ABORTED;
+        }
+      }
+
+      *RsdpPtr = RsdpStructurePtr;
+      return EFI_SUCCESS;
+    }
+  }
+
+  return EFI_NOT_FOUND;
+}

OvmfPkg/Library/AcpiPlatformLib/DxeAcpiPlatformLib.inf

@@ -0,0 +1,26 @@
+## @file
+#  ACPI Platform Library Instance.
+#
+#  Copyright (C) 2023, Corvin Köhne <corvink@FreeBSD.org>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION    = 0x00010005
+  BASE_NAME      = DxeAcpiPlatformLib
+  FILE_GUID      = 578F441A-4A4C-4D24-B9BE-F783152B46F6
+  MODULE_TYPE    = DXE_DRIVER
+  VERSION_STRING = 1.0
+  LIBRARY_CLASS  = AcpiPlatformLib
+
+[Sources]
+  DxeAcpiPlatformLib.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib

OvmfPkg/OvmfPkg.dec

@@ -20,6 +20,10 @@
   Csm/Include
 
 [LibraryClasses]
+  ##  @libraryclass  Search and install ACPI tables.
+  #
+  AcpiPlatformLib|Include/Library/AcpiPlatformLib.h
+
   ##  @libraryclass  Access bhyve's firmware control interface.
   BhyveFwCtlLib|Include/Library/BhyveFwCtlLib.h
 

OvmfPkg/OvmfXen.dsc

@@ -322,6 +322,7 @@
   PciLib|OvmfPkg/Library/DxePciLibI440FxQ35/DxePciLibI440FxQ35.inf
 
 [LibraryClasses.common.DXE_DRIVER]
+  AcpiPlatformLib|OvmfPkg/Library/AcpiPlatformLib/DxeAcpiPlatformLib.inf
   PcdLib|MdePkg/Library/DxePcdLib/DxePcdLib.inf
   ResetSystemLib|OvmfPkg/Library/ResetSystemLib/DxeResetSystemLib.inf
   HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf

OvmfPkg/XenAcpiPlatformDxe/Xen.c

@@ -9,6 +9,7 @@
 
 **/
 
+#include <Library/AcpiPlatformLib.h>
 #include <Library/BaseLib.h>        // CpuDeadLoop()
 #include <Library/DebugLib.h>       // DEBUG()
 #include <Library/XenPlatformLib.h> // XenGetInfoHOB()
@@ -20,92 +21,6 @@
 
 EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *XenAcpiRsdpStructurePtr = NULL;
 
-/**
-  Get the address of Xen ACPI Root System Description Pointer (RSDP)
-  structure.
-
-  @param  RsdpStructurePtr   Return pointer to RSDP structure
-
-  @return EFI_SUCCESS        Find Xen RSDP structure successfully.
-  @return EFI_NOT_FOUND      Don't find Xen RSDP structure.
-  @return EFI_ABORTED        Find Xen RSDP structure, but it's not integrated.
-
-**/
-EFI_STATUS
-EFIAPI
-GetXenAcpiRsdp (
-  OUT   EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  **RsdpPtr
-  )
-{
-  EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *RsdpStructurePtr;
-  UINT8                                         *XenAcpiPtr;
-  UINT8                                         Sum;
-  EFI_XEN_INFO                                  *XenInfo;
-
-  //
-  // Detect the RSDP structure
-  //
-
-  //
-  // First look for PVH one
-  //
-  XenInfo = XenGetInfoHOB ();
-  ASSERT (XenInfo != NULL);
-  if (XenInfo->RsdpPvh != NULL) {
-    DEBUG ((
-      DEBUG_INFO,
-      "%a: Use ACPI RSDP table at 0x%p\n",
-      gEfiCallerBaseName,
-      XenInfo->RsdpPvh
-      ));
-    *RsdpPtr = XenInfo->RsdpPvh;
-    return EFI_SUCCESS;
-  }
-
-  //
-  // Otherwise, look for the HVM one
-  //
-  for (XenAcpiPtr = (UINT8 *)(UINTN)XEN_ACPI_PHYSICAL_ADDRESS;
-       XenAcpiPtr < (UINT8 *)(UINTN)XEN_BIOS_PHYSICAL_END;
-       XenAcpiPtr += 0x10)
-  {
-    RsdpStructurePtr = (EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER *)
-                       (UINTN)XenAcpiPtr;
-
-    if (!AsciiStrnCmp ((CHAR8 *)&RsdpStructurePtr->Signature, "RSD PTR ", 8)) {
-      //
-      // RSDP ACPI 1.0 checksum for 1.0/2.0/3.0 table.
-      // This is only the first 20 bytes of the structure
-      //
-      Sum = CalculateSum8 (
-              (CONST UINT8 *)RsdpStructurePtr,
-              sizeof (EFI_ACPI_1_0_ROOT_SYSTEM_DESCRIPTION_POINTER)
-              );
-      if (Sum != 0) {
-        return EFI_ABORTED;
-      }
-
-      if (RsdpStructurePtr->Revision >= 2) {
-        //
-        // RSDP ACPI 2.0/3.0 checksum, this is the entire table
-        //
-        Sum = CalculateSum8 (
-                (CONST UINT8 *)RsdpStructurePtr,
-                sizeof (EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER)
-                );
-        if (Sum != 0) {
-          return EFI_ABORTED;
-        }
-      }
-
-      *RsdpPtr = RsdpStructurePtr;
-      return EFI_SUCCESS;
-    }
-  }
-
-  return EFI_NOT_FOUND;
-}
-
 /**
   Get Xen Acpi tables from the RSDP structure. And installs Xen ACPI tables
   into the RSDT/XSDT using InstallAcpiTable. Some signature of the installed
@@ -142,6 +57,7 @@ InstallXenTables (
   EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *Facs2Table;
   EFI_ACPI_1_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *Facs1Table;
   EFI_ACPI_DESCRIPTION_HEADER                   *DsdtTable;
+  EFI_XEN_INFO                                  *XenInfo;
 
   Fadt2Table           = NULL;
   Fadt1Table           = NULL;
@@ -152,11 +68,34 @@ InstallXenTables (
   NumberOfTableEntries = 0;
 
   //
-  // Try to find Xen ACPI tables
+  // Detect the RSDP structure
   //
-  Status = GetXenAcpiRsdp (&XenAcpiRsdpStructurePtr);
+
-  if (EFI_ERROR (Status)) {
+  //
-    return Status;
+  // First look for PVH one
+  //
+  XenInfo = XenGetInfoHOB ();
+  ASSERT (XenInfo != NULL);
+  if (XenInfo->RsdpPvh != NULL) {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: Use ACPI RSDP table at 0x%p\n",
+      gEfiCallerBaseName,
+      XenInfo->RsdpPvh
+      ));
+    XenAcpiRsdpStructurePtr = XenInfo->RsdpPvh;
+  } else {
+    //
+    // Otherwise, look for the HVM one
+    //
+    Status = GetAcpiRsdpFromMemory (
+               XEN_ACPI_PHYSICAL_ADDRESS,
+               XEN_BIOS_PHYSICAL_END,
+               &XenAcpiRsdpStructurePtr
+               );
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
   }
 
   //

OvmfPkg/XenAcpiPlatformDxe/XenAcpiPlatformDxe.inf

@@ -32,6 +32,7 @@
   OvmfPkg/OvmfPkg.dec
 
 [LibraryClasses]
+  AcpiPlatformLib
   BaseLib
   DebugLib
   UefiBootServicesTableLib