OvmfPkg/XenPlatformPei: Ignore missing PCI Host Bridge on Xen PVH

[mirror_edk2.git] / OvmfPkg / Library / XenPlatformLib / XenPlatformLib.c

/** @file\r
  Get information about Xen\r
\r
  This library simply allow to find out if OVMF is running under Xen and\r
  allow to get more information when it is the case.\r
\r
  Copyright (c) 2019, Citrix Systems, Inc.\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <PiDxe.h>\r
#include <Library/HobLib.h>\r
#include <Library/XenPlatformLib.h>\r
\r
/**\r
  This function return a pointer to the XenInfo HOB.\r
\r
  @return  XenInfo pointer or NULL if not available\r
**/\r
EFI_XEN_INFO *\r
EFIAPI\r
XenGetInfoHOB (\r
  VOID\r
  )\r
{\r
  EFI_HOB_GUID_TYPE  *GuidHob;\r
\r
  GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);\r
  if (GuidHob == NULL) {\r
    return NULL;\r
  }\r
\r
  return (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);\r
}\r
\r
/**\r
  This function detects if OVMF is running on Xen.\r
\r
  @retval TRUE    OVMF is running on Xen\r
  @retval FALSE   Xen has not been detected\r
**/\r
BOOLEAN\r
EFIAPI\r
XenDetected (\r
  VOID\r
  )\r
{\r
  return (XenGetInfoHOB () != NULL);\r
}\r
\r
/**\r
  This function detect if OVMF have started via the PVH entry point.\r
\r
  @retval TRUE  PVH entry point as been used\r
  @retval FALSE OVMF have started via the HVM route\r
**/\r
BOOLEAN\r
EFIAPI\r
XenPvhDetected (\r
  VOID\r
  )\r
{\r
  EFI_XEN_INFO        *XenInfo;\r
\r
  XenInfo = XenGetInfoHOB ();\r
  return (XenInfo != NULL && XenInfo->RsdpPvh != NULL);\r
}\r