1 files changed, 81 insertions, 0 deletions
diff --git a/roms/edk2/OvmfPkg/Library/XenPlatformLib/XenPlatformLib.c b/roms/edk2/OvmfPkg/Library/XenPlatformLib/XenPlatformLib.c
new file mode 100644
index 000000000..8f20ae2d4
--- /dev/null
+++ b/roms/edk2/OvmfPkg/Library/XenPlatformLib/XenPlatformLib.c
@@ -0,0 +1,81 @@
+/** @file
+  Get information about Xen
+
+  This library simply allow to find out if OVMF is running under Xen and
+  allow to get more information when it is the case.
+
+  Copyright (c) 2019, Citrix Systems, Inc.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiDxe.h>
+#include <Library/HobLib.h>
+#include <Library/XenPlatformLib.h>
+
+/**
+  This function return a pointer to the XenInfo HOB.
+
+  @return  XenInfo pointer or NULL if not available
+**/
+EFI_XEN_INFO *
+EFIAPI
+XenGetInfoHOB (
+  VOID
+  )
+{
+  EFI_HOB_GUID_TYPE   *GuidHob;
+  STATIC BOOLEAN      Cached = FALSE;
+  STATIC EFI_XEN_INFO *XenInfo;
+
+  //
+  // Return the cached result for the benefit of XenDetected that can be
+  // called many times.
+  //
+  if (Cached) {
+    return XenInfo;
+  }
+
+  GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);
+  if (GuidHob == NULL) {
+    XenInfo = NULL;
+  } else {
+    XenInfo = (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);
+  }
+  Cached = TRUE;
+  return XenInfo;
+}
+
+/**
+  This function detects if OVMF is running on Xen.
+
+  @retval TRUE    OVMF is running on Xen
+  @retval FALSE   Xen has not been detected
+**/
+BOOLEAN
+EFIAPI
+XenDetected (
+  VOID
+  )
+{
+  return (XenGetInfoHOB () != NULL);
+}
+
+/**
+  This function detect if OVMF have started via the PVH entry point.
+
+  @retval TRUE  PVH entry point as been used
+  @retval FALSE OVMF have started via the HVM route
+**/
+BOOLEAN
+EFIAPI
+XenPvhDetected (
+  VOID
+  )
+{
+  EFI_XEN_INFO        *XenInfo;
+
+  XenInfo = XenGetInfoHOB ();
+  return (XenInfo != NULL && XenInfo->RsdpPvh != NULL);
+}