[edk2-devel] [PATCH 2/6] UefiCpuPkg/LocalApicTimerDxe: Remove NestedInterruptTplLib call

["Ni, Ray" <ray.ni@intel.com>]

a086f4a adds NestedInterruptTplLib call in OvmfPkg/LocalApicTimerDxe to
avoid stack overflow due to interrupt storm in VM guest.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2815
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4162

The interrupt storm only happens in VM guest environment when the VM is
heavily loaded.
The UefiCpuPkg/LocalApicTimerDxe at current stage does not support
the VM guest environment. So, this patch removes the NestedInterruptTplLib
call.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
---
 UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.c   | 11 ++++-------
 UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.inf |  4 +---
 2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.c b/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.c
index 67f4dcde37..f36a0e6bf3 100644
--- a/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.c
+++ b/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.c
@@ -1,15 +1,13 @@
 /** @file
   Timer Architectural Protocol as defined in the DXE CIS
 
-Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2005 - 2024, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2019, Citrix Systems, Inc.
 
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
-#include <Library/NestedInterruptTplLib.h>
-
 #include "LocalApicTimerDxe.h"
 
 //
@@ -60,10 +58,9 @@ TimerInterruptHandler (
   IN EFI_SYSTEM_CONTEXT  SystemContext
   )
 {
-  STATIC NESTED_INTERRUPT_STATE  NestedInterruptState;
-  EFI_TPL                        OriginalTPL;
+  EFI_TPL  OriginalTPL;
 
-  OriginalTPL = NestedInterruptRaiseTPL ();
+  OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
 
   SendApicEoi ();
 
@@ -74,7 +71,7 @@ TimerInterruptHandler (
     mTimerNotifyFunction (mTimerPeriod);
   }
 
-  NestedInterruptRestoreTPL (OriginalTPL, SystemContext, &NestedInterruptState);
+  gBS->RestoreTPL (OriginalTPL);
 }
 
 /**
diff --git a/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.inf b/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.inf
index 6c711bd163..874d58fa17 100644
--- a/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.inf
+++ b/UefiCpuPkg/LocalApicTimerDxe/LocalApicTimerDxe.inf
@@ -2,7 +2,7 @@
 # Local APIC timer driver that provides Timer Arch protocol.
 # PcdFSBClock is defined in MdePkg and it should be set by the consumer.
 #
-# Copyright (c) 2005 - 2019, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2005 - 2024, Intel Corporation. All rights reserved.<BR>
 # Copyright (c) 2019, Citrix Systems, Inc.
 #
 # SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -21,13 +21,11 @@
 [Packages]
   MdePkg/MdePkg.dec
   UefiCpuPkg/UefiCpuPkg.dec
-  OvmfPkg/OvmfPkg.dec
 
 [LibraryClasses]
   UefiBootServicesTableLib
   BaseLib
   DebugLib
-  NestedInterruptTplLib
   UefiDriverEntryPoint
   LocalApicLib
 
-- 
2.39.1.windows.1



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