[edk2-devel] [PATCH v3 27/35] OvmfPkg/XenPlatformLib: Cache result for XenDetected

[Anthony PERARD]

We are going to replace XenDetected() implementation in
PlatformBootManagerLib by the one in XenPlatformLib.
PlatformBootManagerLib's implementation does cache the result of
GetFirstGuidHob(), so we do something similar in XenPlatformLib.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard at citrix.com>
---

Notes:
    v3:
    - new patch

 .../Library/XenPlatformLib/XenPlatformLib.c    | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/OvmfPkg/Library/XenPlatformLib/XenPlatformLib.c b/OvmfPkg/Library/XenPlatformLib/XenPlatformLib.c
index 6f27cbffa8..b5257b0c97 100644
--- a/OvmfPkg/Library/XenPlatformLib/XenPlatformLib.c
+++ b/OvmfPkg/Library/XenPlatformLib/XenPlatformLib.c
@@ -26,13 +26,25 @@ XenGetInfoHOB (
   )

 {

   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) {

-    return NULL;

+    XenInfo = NULL;

+  } else {

+    XenInfo = (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);

   }

-

-  return (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);

+  Cached = TRUE;

+  return XenInfo;

 }

 

 /**

-- 
Anthony PERARD


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