From 9bf175beabab17dae1b5883d528ae3d9d834249b Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Wed, 24 Jun 2020 11:31:36 +0200
Subject: [PATCH] OvmfPkg/QemuKernelLoaderFsDxe: suppress error on no "-kernel"
 in silent aa64 build (RH)

Notes about the RHEL-8.3/20200603-ca407c7246bf [edk2-stable202005] ->
RHEL-8.5/20210520-e1999b264f1f [edk2-stable202105] rebase:

- Remove obsolete commit message tags related to downstream patch
  management: Message-id, Patchwork-id, O-Subject, Acked-by, From,
  RH-Acked-by, RH-Author (RHBZ#1846481).

Bugzilla: 1844682

If the "-kernel" QEMU option is not used, then QemuKernelLoaderFsDxe
should return EFI_NOT_FOUND, so that the DXE Core can unload it. However,
the associated error message, logged by the DXE Core to the serial
console, is not desired in the silent edk2-aarch64 build, given that the
absence of "-kernel" is nothing out of the ordinary. Therefore, return
success and stay resident. The wasted guest RAM still gets freed after
ExitBootServices().

(Inspired by RHEL-8.1.0 commit aaaedc1e2cfd.)

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
(cherry picked from commit 9adcdf493ebbd11efb74e2905ab5f6c8996e096d)
---
 .../QemuKernelLoaderFsDxe.c                     | 17 +++++++++++++++++
 .../QemuKernelLoaderFsDxe.inf                   |  1 +
 2 files changed, 18 insertions(+)

diff --git a/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c b/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c
index 3c12085f6c..e192809198 100644
--- a/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c
+++ b/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.c
@@ -19,6 +19,7 @@
 #include <Library/BaseMemoryLib.h>
 #include <Library/BlobVerifierLib.h>
 #include <Library/DebugLib.h>
+#include <Library/DebugPrintErrorLevelLib.h>
 #include <Library/DevicePathLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/QemuFwCfgLib.h>
@@ -1081,6 +1082,22 @@ QemuKernelLoaderFsDxeEntrypoint (
 
   if (KernelBlob->Data == NULL) {
     Status = EFI_NOT_FOUND;
+#if defined (MDE_CPU_AARCH64)
+    //
+    // RHBZ#1844682
+    //
+    // If the "-kernel" QEMU option is not being used, this platform DXE driver
+    // should return EFI_NOT_FOUND, so that the DXE Core can unload it.
+    // However, the associated error message, logged by the DXE Core to the
+    // serial console, is not desired in the silent edk2-aarch64 build, given
+    // that the absence of "-kernel" is nothing out of the ordinary. Therefore,
+    // return success and stay resident. The wasted guest RAM still gets freed
+    // after ExitBootServices().
+    //
+    if (GetDebugPrintErrorLevel () == DEBUG_ERROR) {
+      Status = EFI_SUCCESS;
+    }
+#endif
     goto FreeBlobs;
   }
 
diff --git a/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.inf b/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.inf
index 7b35adb8e0..23d9f5fca1 100644
--- a/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.inf
+++ b/OvmfPkg/QemuKernelLoaderFsDxe/QemuKernelLoaderFsDxe.inf
@@ -28,6 +28,7 @@
   BaseLib
   BaseMemoryLib
   DebugLib
+  DebugPrintErrorLevelLib
   DevicePathLib
   MemoryAllocationLib
   QemuFwCfgLib