OvmfPkg/Library/XenPlatformLib/XenPlatformLib.c

   1 /** @file
   2   Get information about Xen
   3
   4   This library simply allow to find out if OVMF is running under Xen and
   5   allow to get more information when it is the case.
   6
   7   Copyright (c) 2019, Citrix Systems, Inc.
   8
   9   SPDX-License-Identifier: BSD-2-Clause-Patent
  10
  11 **/
  12
  13 #include <PiDxe.h>
  14 #include <Library/HobLib.h>
  15 #include <Library/XenPlatformLib.h>
  16
  17 /**
  18   This function return a pointer to the XenInfo HOB.
  19
  20   @return  XenInfo pointer or NULL if not available
  21 **/
  22 EFI_XEN_INFO *
  23 EFIAPI
  24 XenGetInfoHOB (
  25   VOID
  26   )
  27 {
  28   EFI_HOB_GUID_TYPE  *GuidHob;
  29
  30   GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);
  31   if (GuidHob == NULL) {
  32     return NULL;
  33   }
  34
  35   return (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);
  36 }
  37
  38 /**
  39   This function detects if OVMF is running on Xen.
  40
  41   @retval TRUE    OVMF is running on Xen
  42   @retval FALSE   Xen has not been detected
  43 **/
  44 BOOLEAN
  45 EFIAPI
  46 XenDetected (
  47   VOID
  48   )
  49 {
  50   return (XenGetInfoHOB () != NULL);
  51 }
  52
  53 /**
  54   This function detect if OVMF have started via the PVH entry point.
  55
  56   @retval TRUE  PVH entry point as been used
  57   @retval FALSE OVMF have started via the HVM route
  58 **/
  59 BOOLEAN
  60 EFIAPI
  61 XenPvhDetected (
  62   VOID
  63   )
  64 {
  65   EFI_XEN_INFO        *XenInfo;
  66
  67   XenInfo = XenGetInfoHOB ();
  68   return (XenInfo != NULL && XenInfo->RsdpPvh != NULL);
  69 }