From 2f91cf9045bf43a24c99c8df799a92841eb9ad28 Mon Sep 17 00:00:00 2001
From: Sami Mujawar <sami.mujawar@arm.com>
Date: Mon, 15 Jun 2026 18:03:33 +0100
Subject: [PATCH] ArmVirtPkg: Refactor memory map configuration for Kvmtool
 Guest VM

Refactor the memory mapping configuration for Kvmtool Guest VM to
only setup the memory map for the System Memory, FV and the Serial
Port.

The memory mappings for he remaining devices are expected to be
configured by the respective drivers, this could be done as part
of the DXE drivers itself or using a Probe Library that adds the
device memory regions to the memory map.

The only special cases that remain are the System Memory, FV and
the Serial Port for which the memory mappings are created by the
KvmtoolVirtMemInfoLib. The memory mapping for the Serial port
is added as it is utilised for logging before the DXE driver
is loaded.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
---
 ArmVirtPkg/ArmVirtKvmTool.dsc                 |  1 +
 .../KvmtoolVirtMemInfoLib.c                   | 24 +++++--------------
 .../KvmtoolVirtMemInfoLib.inf                 |  3 +--
 3 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/ArmVirtPkg/ArmVirtKvmTool.dsc b/ArmVirtPkg/ArmVirtKvmTool.dsc
index 91411b5264..b91a64a0e0 100644
--- a/ArmVirtPkg/ArmVirtKvmTool.dsc
+++ b/ArmVirtPkg/ArmVirtKvmTool.dsc
@@ -227,6 +227,7 @@
       HobLib|EmbeddedPkg/Library/PrePiHobLib/PrePiHobLib.inf
       PrePiHobListPointerLib|ArmPlatformPkg/Library/PrePiHobListPointerLib/PrePiHobListPointerLib.inf
       MemoryAllocationLib|EmbeddedPkg/Library/PrePiMemoryAllocationLib/PrePiMemoryAllocationLib.inf
+      NULL|ArmVirtPkg/Library/Fdt16550SerialPortHookLib/EarlyFdt16550SerialPortProbeLib.inf
   }
 
   #
diff --git a/ArmVirtPkg/Library/KvmtoolVirtMemInfoLib/KvmtoolVirtMemInfoLib.c b/ArmVirtPkg/Library/KvmtoolVirtMemInfoLib/KvmtoolVirtMemInfoLib.c
index 79412897f2..e5612bb75d 100644
--- a/ArmVirtPkg/Library/KvmtoolVirtMemInfoLib/KvmtoolVirtMemInfoLib.c
+++ b/ArmVirtPkg/Library/KvmtoolVirtMemInfoLib/KvmtoolVirtMemInfoLib.c
@@ -1,7 +1,7 @@
 /** @file
   Kvmtool virtual memory map library.
 
-  Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.
+  Copyright (c) 2018 - 2026, ARM Limited. All rights reserved.
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -9,8 +9,6 @@
 
 #include <Base.h>
 #include <Library/ArmLib.h>
-#include <Library/BaseLib.h>
-#include <Library/BaseMemoryLib.h>
 #include <Library/DebugLib.h>
 #include <Library/MemoryAllocationLib.h>
 
@@ -37,12 +35,9 @@ ArmVirtGetMemoryMap (
 {
   ARM_MEMORY_REGION_DESCRIPTOR  *VirtualMemoryTable;
   UINTN                         Idx;
-  EFI_PHYSICAL_ADDRESS          TopOfAddressSpace;
 
   ASSERT (VirtualMemoryMap != NULL);
 
-  TopOfAddressSpace = LShiftU64 (1ULL, ArmGetPhysicalAddressBits ());
-
   VirtualMemoryTable = (ARM_MEMORY_REGION_DESCRIPTOR *)
                        AllocatePages (
                          EFI_SIZE_TO_PAGES (
@@ -66,20 +61,13 @@ ArmVirtGetMemoryMap (
   VirtualMemoryTable[Idx].Length       = PcdGet64 (PcdSystemMemorySize);
   VirtualMemoryTable[Idx].Attributes   = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
 
-  // Peripheral space before DRAM
-  VirtualMemoryTable[++Idx].PhysicalBase = 0x0;
-  VirtualMemoryTable[Idx].VirtualBase    = 0x0;
-  VirtualMemoryTable[Idx].Length         = PcdGet64 (PcdSystemMemoryBase);
+  // Map the UART
+  ASSERT (IS_ALIGNED (PcdGet64 (PcdSerialRegisterBase), EFI_PAGE_SIZE));
+  VirtualMemoryTable[++Idx].PhysicalBase = PcdGet64 (PcdSerialRegisterBase);
+  VirtualMemoryTable[Idx].VirtualBase    = PcdGet64 (PcdSerialRegisterBase);
+  VirtualMemoryTable[Idx].Length         = EFI_PAGE_SIZE;
   VirtualMemoryTable[Idx].Attributes     = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
 
-  // Peripheral space after DRAM
-  VirtualMemoryTable[++Idx].PhysicalBase = PcdGet64 (PcdSystemMemoryBase) +
-                                           PcdGet64 (PcdSystemMemorySize);
-  VirtualMemoryTable[Idx].VirtualBase = VirtualMemoryTable[Idx].PhysicalBase;
-  VirtualMemoryTable[Idx].Length      = TopOfAddressSpace -
-                                        VirtualMemoryTable[Idx].PhysicalBase;
-  VirtualMemoryTable[Idx].Attributes = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
-
   // Map the FV region as normal executable memory
   VirtualMemoryTable[++Idx].PhysicalBase = PcdGet64 (PcdFvBaseAddress);
   VirtualMemoryTable[Idx].VirtualBase    = VirtualMemoryTable[Idx].PhysicalBase;
diff --git a/ArmVirtPkg/Library/KvmtoolVirtMemInfoLib/KvmtoolVirtMemInfoLib.inf b/ArmVirtPkg/Library/KvmtoolVirtMemInfoLib/KvmtoolVirtMemInfoLib.inf
index a354e734ab..16b3564e48 100644
--- a/ArmVirtPkg/Library/KvmtoolVirtMemInfoLib/KvmtoolVirtMemInfoLib.inf
+++ b/ArmVirtPkg/Library/KvmtoolVirtMemInfoLib/KvmtoolVirtMemInfoLib.inf
@@ -27,8 +27,6 @@
 
 [LibraryClasses]
   ArmLib
-  BaseLib
-  BaseMemoryLib
   DebugLib
   MemoryAllocationLib
   PcdLib
@@ -37,6 +35,7 @@
   gArmTokenSpaceGuid.PcdFvBaseAddress
   gArmTokenSpaceGuid.PcdSystemMemoryBase
   gArmTokenSpaceGuid.PcdSystemMemorySize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialRegisterBase
 
 [FixedPcd]
   gArmTokenSpaceGuid.PcdFvSize