From 8e934ab9562a33191af21ce3babf1ad37a3cdc34 Mon Sep 17 00:00:00 2001
From: Sami Mujawar <sami.mujawar@arm.com>
Date: Fri, 12 May 2023 09:54:34 +0100
Subject: ArmVirtPkg: Dispatch variable service if variable emulation is
 enabled

The VariableRuntimeDxe links with NvVarStoreFormattedLib which is
required to establish the dependency on OvmfPkg\VirtNorFlashDxe.
The VirtNorFlashDxe installs the gEdkiiNvVarStoreFormattedGuid to
indicate it has finished initialising the flash variable storage
and that the variable service can be dispatched.

However, the kvmtool guest firmware dynamically detects if CFI
flash is absent and sets PcdEmuVariableNvModeEnable to TRUE
indicating emulated runtime variable must be used. Therefore,
in this scenario install the gEdkiiNvVarStoreFormattedGuid so
that the variable service can be dispatched.

Also link the NorFlashKvmtoolLib as a NULL library so that
it can discover if the CFI flash is absent and setup the PCD
PcdEmuVariableNvModeEnable. This is required in case the
NorFlashDxe is not yet dispatched.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
---
 ArmVirtPkg/ArmVirtKvmTool.dsc                        |  5 ++++-
 ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c   | 13 ++++++++++++-
 ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf |  4 +++-
 3 files changed, 19 insertions(+), 3 deletions(-)

(limited to 'ArmVirtPkg')

diff --git a/ArmVirtPkg/ArmVirtKvmTool.dsc b/ArmVirtPkg/ArmVirtKvmTool.dsc
index 25920ab4ae..4541d03d23 100644
--- a/ArmVirtPkg/ArmVirtKvmTool.dsc
+++ b/ArmVirtPkg/ArmVirtKvmTool.dsc
@@ -311,7 +311,10 @@
   #
   # Platform Driver
   #
-  ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf
+  ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf {
+    <LibraryClasses>
+    NULL|ArmVirtPkg/Library/NorFlashKvmtoolLib/NorFlashKvmtoolLib.inf
+  }
   OvmfPkg/Fdt/VirtioFdtDxe/VirtioFdtDxe.inf
   EmbeddedPkg/Drivers/FdtClientDxe/FdtClientDxe.inf
   OvmfPkg/Fdt/HighMemDxe/HighMemDxe.inf
diff --git a/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c
index 3f5027fac4..bf6fc1f1f0 100644
--- a/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c
+++ b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c
@@ -4,7 +4,7 @@
   - It decides if the firmware should expose ACPI or Device Tree-based
     hardware description to the operating system.
 
-  Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.
+  Copyright (c) 2018 - 2023, Arm Limited. All rights reserved.
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -75,6 +75,17 @@ KvmtoolPlatformDxeEntryPoint (
 {
   EFI_STATUS  Status;
 
+  if (PcdGetBool (PcdEmuVariableNvModeEnable)) {
+    // The driver implementing the variable service can now be dispatched.
+    Status = gBS->InstallProtocolInterface (
+                    &gImageHandle,
+                    &gEdkiiNvVarStoreFormattedGuid,
+                    EFI_NATIVE_INTERFACE,
+                    NULL
+                    );
+    ASSERT_EFI_ERROR (Status);
+  }
+
   Status = PlatformHasAcpiDt (ImageHandle);
   ASSERT_EFI_ERROR (Status);
 
diff --git a/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf
index c5bf798c3b..b0583d5205 100644
--- a/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf
+++ b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf
@@ -3,7 +3,7 @@
 #  - It decides if the firmware should expose ACPI or Device Tree-based
 #    hardware description to the operating system.
 #
-#  Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.
+#  Copyright (c) 2018 - 2023, Arm Limited. All rights reserved.
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -33,10 +33,12 @@
   UefiDriverEntryPoint
 
 [Guids]
+  gEdkiiNvVarStoreFormattedGuid   ## SOMETIMES_PRODUCES ## PROTOCOL
   gEdkiiPlatformHasAcpiGuid       ## SOMETIMES_PRODUCES ## PROTOCOL
   gEdkiiPlatformHasDeviceTreeGuid ## SOMETIMES_PRODUCES ## PROTOCOL
 
 [Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdEmuVariableNvModeEnable
   gUefiOvmfPkgTokenSpaceGuid.PcdForceNoAcpi
 
 [Depex]
-- 
cgit v1.2.3