Implement support for page sizes > 4KB (#4252)

* Implement support for page sizes > 4KB

* Check and work around more alignment issues

* Was not meant to change this

* Use MemoryBlock.GetPageSize() value for signal handler code

* Do not take the path for private allocations if host supports 4KB pages

* Add Flags attribute on MemoryMapFlags

* Fix dirty region size with 16kb pages

Would accidentally report a size that was too high (generally 16k instead of 4k, uploading 4x as much data)

Co-authored-by: riperiperi <rhy3756547@hotmail.com>

ARMeilleure/Memory/IJitMemoryAllocator.cs

@@ -4,5 +4,7 @@
     {
         IJitMemoryBlock Allocate(ulong size);
         IJitMemoryBlock Reserve(ulong size);
+
+        ulong GetPageSize();
     }
 }

ARMeilleure/Signal/NativeSignalHandler.cs

@@ -71,8 +71,8 @@ namespace ARMeilleure.Signal
 
         private const uint EXCEPTION_ACCESS_VIOLATION = 0xc0000005;
 
-        private static ulong _pageSize = GetPageSize();
-        private static ulong _pageMask = _pageSize - 1;
+        private static ulong _pageSize;
+        private static ulong _pageMask;
 
         private static IntPtr _handlerConfig;
         private static IntPtr _signalHandlerPtr;
@@ -81,19 +81,6 @@ namespace ARMeilleure.Signal
         private static readonly object _lock = new object();
         private static bool _initialized;
 
-        private static ulong GetPageSize()
-        {
-            // TODO: This needs to be based on the current memory manager configuration.
-            if (OperatingSystem.IsMacOS() && RuntimeInformation.ProcessArchitecture == Architecture.Arm64)
-            {
-                return 1UL << 14;
-            }
-            else
-            {
-                return 1UL << 12;
-            }
-        }
-
         static NativeSignalHandler()
         {
             _handlerConfig = Marshal.AllocHGlobal(Unsafe.SizeOf<SignalHandlerConfig>());
@@ -102,12 +89,12 @@ namespace ARMeilleure.Signal
             config = new SignalHandlerConfig();
         }
 
-        public static void InitializeJitCache(IJitMemoryAllocator allocator)
+        public static void Initialize(IJitMemoryAllocator allocator)
         {
             JitCache.Initialize(allocator);
         }
 
-        public static void InitializeSignalHandler(Func<IntPtr, IntPtr, IntPtr> customSignalHandlerFactory = null)
+        public static void InitializeSignalHandler(ulong pageSize, Func<IntPtr, IntPtr, IntPtr> customSignalHandlerFactory = null)
         {
             if (_initialized) return;
 
@@ -115,6 +102,9 @@ namespace ARMeilleure.Signal
             {
                 if (_initialized) return;
 
+                _pageSize = pageSize;
+                _pageMask = pageSize - 1;
+
                 ref SignalHandlerConfig config = ref GetConfigRef();
 
                 if (OperatingSystem.IsLinux() || OperatingSystem.IsMacOS())

ARMeilleure/Translation/Translator.cs

@@ -81,7 +81,7 @@ namespace ARMeilleure.Translation
 
             if (memory.Type.IsHostMapped())
             {
-                NativeSignalHandler.InitializeSignalHandler();
+                NativeSignalHandler.InitializeSignalHandler(allocator.GetPageSize());
             }
         }
 

Ryujinx.Cpu/AddressSpace.cs

@@ -0,0 +1,470 @@
+using Ryujinx.Common;
+using Ryujinx.Common.Collections;
+using Ryujinx.Memory;
+using System;
+
+namespace Ryujinx.Cpu
+{
+    class AddressSpace : IDisposable
+    {
+        private const ulong PageSize = 0x1000;
+
+        private const int DefaultBlockAlignment = 1 << 20;
+
+        private enum MappingType : byte
+        {
+            None,
+            Private,
+            Shared
+        }
+
+        private class Mapping : IntrusiveRedBlackTreeNode<Mapping>, IComparable<Mapping>
+        {
+            public ulong Address { get; private set; }
+            public ulong Size { get; private set; }
+            public ulong EndAddress => Address + Size;
+            public MappingType Type { get; private set; }
+
+            public Mapping(ulong address, ulong size, MappingType type)
+            {
+                Address = address;
+                Size = size;
+                Type = type;
+            }
+
+            public Mapping Split(ulong splitAddress)
+            {
+                ulong leftSize = splitAddress - Address;
+                ulong rightSize = EndAddress - splitAddress;
+
+                Mapping left = new Mapping(Address, leftSize, Type);
+
+                Address = splitAddress;
+                Size = rightSize;
+
+                return left;
+            }
+
+            public void UpdateState(MappingType newType)
+            {
+                Type = newType;
+            }
+
+            public void Extend(ulong sizeDelta)
+            {
+                Size += sizeDelta;
+            }
+
+            public int CompareTo(Mapping other)
+            {
+                if (Address < other.Address)
+                {
+                    return -1;
+                }
+                else if (Address <= other.EndAddress - 1UL)
+                {
+                    return 0;
+                }
+                else
+                {
+                    return 1;
+                }
+            }
+        }
+
+        private class PrivateMapping : IntrusiveRedBlackTreeNode<PrivateMapping>, IComparable<PrivateMapping>
+        {
+            public ulong Address { get; private set; }
+            public ulong Size { get; private set; }
+            public ulong EndAddress => Address + Size;
+            public PrivateMemoryAllocation PrivateAllocation { get; private set; }
+
+            public PrivateMapping(ulong address, ulong size, PrivateMemoryAllocation privateAllocation)
+            {
+                Address = address;
+                Size = size;
+                PrivateAllocation = privateAllocation;
+            }
+
+            public PrivateMapping Split(ulong splitAddress)
+            {
+                ulong leftSize = splitAddress - Address;
+                ulong rightSize = EndAddress - splitAddress;
+
+                (var leftAllocation, PrivateAllocation) = PrivateAllocation.Split(leftSize);
+
+                PrivateMapping left = new PrivateMapping(Address, leftSize, leftAllocation);
+
+                Address = splitAddress;
+                Size = rightSize;
+
+                return left;
+            }
+
+            public void Map(MemoryBlock baseBlock, MemoryBlock mirrorBlock, PrivateMemoryAllocation newAllocation)
+            {
+                baseBlock.MapView(newAllocation.Memory, newAllocation.Offset, Address, Size);
+                mirrorBlock.MapView(newAllocation.Memory, newAllocation.Offset, Address, Size);
+                PrivateAllocation = newAllocation;
+            }
+
+            public void Unmap(MemoryBlock baseBlock, MemoryBlock mirrorBlock)
+            {
+                if (PrivateAllocation.IsValid)
+                {
+                    baseBlock.UnmapView(PrivateAllocation.Memory, Address, Size);
+                    mirrorBlock.UnmapView(PrivateAllocation.Memory, Address, Size);
+                    PrivateAllocation.Dispose();
+                }
+
+                PrivateAllocation = default;
+            }
+
+            public void Extend(ulong sizeDelta)
+            {
+                Size += sizeDelta;
+            }
+
+            public int CompareTo(PrivateMapping other)
+            {
+                if (Address < other.Address)
+                {
+                    return -1;
+                }
+                else if (Address <= other.EndAddress - 1UL)
+                {
+                    return 0;
+                }
+                else
+                {
+                    return 1;
+                }
+            }
+        }
+
+        private readonly MemoryBlock _backingMemory;
+        private readonly PrivateMemoryAllocator _privateMemoryAllocator;
+        private readonly IntrusiveRedBlackTree<Mapping> _mappingTree;
+        private readonly IntrusiveRedBlackTree<PrivateMapping> _privateTree;
+
+        private readonly object _treeLock;
+
+        private readonly bool _supports4KBPages;
+
+        public MemoryBlock Base { get; }
+        public MemoryBlock Mirror { get; }
+
+        public AddressSpace(MemoryBlock backingMemory, ulong asSize, bool supports4KBPages)
+        {
+            if (!supports4KBPages)
+            {
+                _privateMemoryAllocator = new PrivateMemoryAllocator(DefaultBlockAlignment, MemoryAllocationFlags.Mirrorable | MemoryAllocationFlags.NoMap);
+                _mappingTree = new IntrusiveRedBlackTree<Mapping>();
+                _privateTree = new IntrusiveRedBlackTree<PrivateMapping>();
+                _treeLock = new object();
+
+                _mappingTree.Add(new Mapping(0UL, asSize, MappingType.None));
+                _privateTree.Add(new PrivateMapping(0UL, asSize, default));
+            }
+
+            _backingMemory = backingMemory;
+            _supports4KBPages = supports4KBPages;
+
+            MemoryAllocationFlags asFlags = MemoryAllocationFlags.Reserve | MemoryAllocationFlags.ViewCompatible;
+
+            Base = new MemoryBlock(asSize, asFlags);
+            Mirror = new MemoryBlock(asSize, asFlags);
+        }
+
+        public void Map(ulong va, ulong pa, ulong size, MemoryMapFlags flags)
+        {
+            if (_supports4KBPages)
+            {
+                Base.MapView(_backingMemory, pa, va, size);
+                Mirror.MapView(_backingMemory, pa, va, size);
+
+                return;
+            }
+
+            lock (_treeLock)
+            {
+                ulong alignment = MemoryBlock.GetPageSize();
+                bool isAligned = ((va | pa | size) & (alignment - 1)) == 0;
+
+                if (flags.HasFlag(MemoryMapFlags.Private) && !isAligned)
+                {
+                    Update(va, pa, size, MappingType.Private);
+                }
+                else
+                {
+                    // The update method assumes that shared mappings are already aligned.
+
+                    if (!flags.HasFlag(MemoryMapFlags.Private))
+                    {
+                        if ((va & (alignment - 1)) != (pa & (alignment - 1)))
+                        {
+                            throw new InvalidMemoryRegionException($"Virtual address 0x{va:X} and physical address 0x{pa:X} are misaligned and can't be aligned.");
+                        }
+
+                        ulong endAddress = va + size;
+                        va = BitUtils.AlignDown(va, alignment);
+                        pa = BitUtils.AlignDown(pa, alignment);
+                        size = BitUtils.AlignUp(endAddress, alignment) - va;
+                    }
+
+                    Update(va, pa, size, MappingType.Shared);
+                }
+            }
+        }
+
+        public void Unmap(ulong va, ulong size)
+        {
+            if (_supports4KBPages)
+            {
+                Base.UnmapView(_backingMemory, va, size);
+                Mirror.UnmapView(_backingMemory, va, size);
+
+                return;
+            }
+
+            lock (_treeLock)
+            {
+                Update(va, 0UL, size, MappingType.None);
+            }
+        }
+
+        private void Update(ulong va, ulong pa, ulong size, MappingType type)
+        {
+            Mapping map = _mappingTree.GetNode(new Mapping(va, 1UL, MappingType.None));
+
+            Update(map, va, pa, size, type);
+        }
+
+        private Mapping Update(Mapping map, ulong va, ulong pa, ulong size, MappingType type)
+        {
+            ulong endAddress = va + size;
+
+            for (; map != null; map = map.Successor)
+            {
+                if (map.Address < va)
+                {
+                    _mappingTree.Add(map.Split(va));
+                }
+
+                if (map.EndAddress > endAddress)
+                {
+                    Mapping newMap = map.Split(endAddress);
+                    _mappingTree.Add(newMap);
+                    map = newMap;
+                }
+
+                switch (type)
+                {
+                    case MappingType.None:
+                        if (map.Type == MappingType.Shared)
+                        {
+                            ulong startOffset = map.Address - va;
+                            ulong mapVa = va + startOffset;
+                            ulong mapSize = Math.Min(size - startOffset, map.Size);
+                            ulong mapEndAddress = mapVa + mapSize;
+                            ulong alignment = MemoryBlock.GetPageSize();
+
+                            mapVa = BitUtils.AlignDown(mapVa, alignment);
+                            mapEndAddress = BitUtils.AlignUp(mapEndAddress, alignment);
+
+                            mapSize = mapEndAddress - mapVa;
+
+                            Base.UnmapView(_backingMemory, mapVa, mapSize);
+                            Mirror.UnmapView(_backingMemory, mapVa, mapSize);
+                        }
+                        else
+                        {
+                            UnmapPrivate(va, size);
+                        }
+                        break;
+                    case MappingType.Private:
+                        if (map.Type == MappingType.Shared)
+                        {
+                            throw new InvalidMemoryRegionException($"Private mapping request at 0x{va:X} with size 0x{size:X} overlaps shared mapping at 0x{map.Address:X} with size 0x{map.Size:X}.");
+                        }
+                        else
+                        {
+                            MapPrivate(va, size);
+                        }
+                        break;
+                    case MappingType.Shared:
+                        if (map.Type != MappingType.None)
+                        {
+                            throw new InvalidMemoryRegionException($"Shared mapping request at 0x{va:X} with size 0x{size:X} overlaps mapping at 0x{map.Address:X} with size 0x{map.Size:X}.");
+                        }
+                        else
+                        {
+                            ulong startOffset = map.Address - va;
+                            ulong mapPa = pa + startOffset;
+                            ulong mapVa = va + startOffset;
+                            ulong mapSize = Math.Min(size - startOffset, map.Size);
+
+                            Base.MapView(_backingMemory, mapPa, mapVa, mapSize);
+                            Mirror.MapView(_backingMemory, mapPa, mapVa, mapSize);
+                        }
+                        break;
+                }
+
+                map.UpdateState(type);
+                map = TryCoalesce(map);
+
+                if (map.EndAddress >= endAddress)
+                {
+                    break;
+                }
+            }
+
+            return map;
+        }
+
+        private Mapping TryCoalesce(Mapping map)
+        {
+            Mapping previousMap = map.Predecessor;
+            Mapping nextMap = map.Successor;
+
+            if (previousMap != null && CanCoalesce(previousMap, map))
+            {
+                previousMap.Extend(map.Size);
+                _mappingTree.Remove(map);
+                map = previousMap;
+            }
+
+            if (nextMap != null && CanCoalesce(map, nextMap))
+            {
+                map.Extend(nextMap.Size);
+                _mappingTree.Remove(nextMap);
+            }
+
+            return map;
+        }
+
+        private static bool CanCoalesce(Mapping left, Mapping right)
+        {
+            return left.Type == right.Type;
+        }
+
+        private void MapPrivate(ulong va, ulong size)
+        {
+            ulong endAddress = va + size;
+
+            ulong alignment = MemoryBlock.GetPageSize();
+
+            // Expand the range outwards based on page size to ensure that at least the requested region is mapped.
+            ulong vaAligned = BitUtils.AlignDown(va, alignment);
+            ulong endAddressAligned = BitUtils.AlignUp(endAddress, alignment);
+
+            ulong sizeAligned = endAddressAligned - vaAligned;
+
+            PrivateMapping map = _privateTree.GetNode(new PrivateMapping(va, 1UL, default));
+
+            for (; map != null; map = map.Successor)
+            {
+                if (!map.PrivateAllocation.IsValid)
+                {
+                    if (map.Address < vaAligned)
+                    {
+                        _privateTree.Add(map.Split(vaAligned));
+                    }
+
+                    if (map.EndAddress > endAddressAligned)
+                    {
+                        PrivateMapping newMap = map.Split(endAddressAligned);
+                        _privateTree.Add(newMap);
+                        map = newMap;
+                    }
+
+                    map.Map(Base, Mirror, _privateMemoryAllocator.Allocate(map.Size, MemoryBlock.GetPageSize()));
+                }
+
+                if (map.EndAddress >= endAddressAligned)
+                {
+                    break;
+                }
+            }
+        }
+
+        private void UnmapPrivate(ulong va, ulong size)
+        {
+            ulong endAddress = va + size;
+
+            ulong alignment = MemoryBlock.GetPageSize();
+
+            // Shrink the range inwards based on page size to ensure we won't unmap memory that might be still in use.
+            ulong vaAligned = BitUtils.AlignUp(va, alignment);
+            ulong endAddressAligned = BitUtils.AlignDown(endAddress, alignment);
+
+            if (endAddressAligned <= vaAligned)
+            {
+                return;
+            }
+
+            ulong alignedSize = endAddressAligned - vaAligned;
+
+            PrivateMapping map = _privateTree.GetNode(new PrivateMapping(va, 1UL, default));
+
+            for (; map != null; map = map.Successor)
+            {
+                if (map.PrivateAllocation.IsValid)
+                {
+                    if (map.Address < vaAligned)
+                    {
+                        _privateTree.Add(map.Split(vaAligned));
+                    }
+
+                    if (map.EndAddress > endAddressAligned)
+                    {
+                        PrivateMapping newMap = map.Split(endAddressAligned);
+                        _privateTree.Add(newMap);
+                        map = newMap;
+                    }
+
+                    map.Unmap(Base, Mirror);
+                    map = TryCoalesce(map);
+                }
+
+                if (map.EndAddress >= endAddressAligned)
+                {
+                    break;
+                }
+            }
+        }
+
+        private PrivateMapping TryCoalesce(PrivateMapping map)
+        {
+            PrivateMapping previousMap = map.Predecessor;
+            PrivateMapping nextMap = map.Successor;
+
+            if (previousMap != null && CanCoalesce(previousMap, map))
+            {
+                previousMap.Extend(map.Size);
+                _privateTree.Remove(map);
+                map = previousMap;
+            }
+
+            if (nextMap != null && CanCoalesce(map, nextMap))
+            {
+                map.Extend(nextMap.Size);
+                _privateTree.Remove(nextMap);
+            }
+
+            return map;
+        }
+
+        private static bool CanCoalesce(PrivateMapping left, PrivateMapping right)
+        {
+            return !left.PrivateAllocation.IsValid && !right.PrivateAllocation.IsValid;
+        }
+
+        public void Dispose()
+        {
+            _privateMemoryAllocator.Dispose();
+            Base.Dispose();
+            Mirror.Dispose();
+        }
+    }
+}

Ryujinx.Cpu/Jit/JitMemoryAllocator.cs

@@ -7,5 +7,7 @@ namespace Ryujinx.Cpu.Jit
     {
         public IJitMemoryBlock Allocate(ulong size) => new JitMemoryBlock(size, MemoryAllocationFlags.None);
         public IJitMemoryBlock Reserve(ulong size) => new JitMemoryBlock(size, MemoryAllocationFlags.Reserve | MemoryAllocationFlags.Jit);
+
+        public ulong GetPageSize() => MemoryBlock.GetPageSize();
     }
 }

Ryujinx.Cpu/Jit/MemoryManager.cs

@@ -28,6 +28,9 @@ namespace Ryujinx.Cpu.Jit
         private readonly MemoryBlock _backingMemory;
         private readonly InvalidAccessHandler _invalidAccessHandler;
 
+        /// <inheritdoc/>
+        public bool Supports4KBPages => true;
+
         /// <summary>
         /// Address space width in bits.
         /// </summary>
@@ -76,7 +79,7 @@ namespace Ryujinx.Cpu.Jit
         }
 
         /// <inheritdoc/>
-        public void Map(ulong va, ulong pa, ulong size)
+        public void Map(ulong va, ulong pa, ulong size, MemoryMapFlags flags)
         {
             AssertValidAddressAndSize(va, size);
 
@@ -91,9 +94,16 @@ namespace Ryujinx.Cpu.Jit
                 pa += PageSize;
                 remainingSize -= PageSize;
             }
+
             Tracking.Map(oVa, size);
         }
 
+        /// <inheritdoc/>
+        public void MapForeign(ulong va, nuint hostPointer, ulong size)
+        {
+            throw new NotSupportedException();
+        }
+
         /// <inheritdoc/>
         public void Unmap(ulong va, ulong size)
         {
@@ -378,6 +388,32 @@ namespace Ryujinx.Cpu.Jit
             return true;
         }
 
+        /// <inheritdoc/>
+        public IEnumerable<HostMemoryRange> GetHostRegions(ulong va, ulong size)
+        {
+            if (size == 0)
+            {
+                return Enumerable.Empty<HostMemoryRange>();
+            }
+
+            var guestRegions = GetPhysicalRegionsImpl(va, size);
+            if (guestRegions == null)
+            {
+                return null;
+            }
+
+            var regions = new HostMemoryRange[guestRegions.Count];
+
+            for (int i = 0; i < regions.Length; i++)
+            {
+                var guestRegion = guestRegions[i];
+                IntPtr pointer = _backingMemory.GetPointer(guestRegion.Address, guestRegion.Size);
+                regions[i] = new HostMemoryRange((nuint)(ulong)pointer, guestRegion.Size);
+            }
+
+            return regions;
+        }
+
         /// <inheritdoc/>
         public IEnumerable<MemoryRange> GetPhysicalRegions(ulong va, ulong size)
         {
@@ -386,6 +422,11 @@ namespace Ryujinx.Cpu.Jit
                 return Enumerable.Empty<MemoryRange>();
             }
 
+            return GetPhysicalRegionsImpl(va, size);
+        }
+
+        private List<MemoryRange> GetPhysicalRegionsImpl(ulong va, ulong size)
+        {
             if (!ValidateAddress(va) || !ValidateAddressAndSize(va, size))
             {
                 return null;

Ryujinx.Cpu/Jit/MemoryManagerHostMapped.cs

@@ -5,6 +5,7 @@ using Ryujinx.Memory.Range;
 using Ryujinx.Memory.Tracking;
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Threading;
 
@@ -37,20 +38,21 @@ namespace Ryujinx.Cpu.Jit
         private readonly InvalidAccessHandler _invalidAccessHandler;
         private readonly bool _unsafeMode;
 
-        private readonly MemoryBlock _addressSpace;
-        private readonly MemoryBlock _addressSpaceMirror;
+        private readonly AddressSpace _addressSpace;
         private readonly ulong _addressSpaceSize;
 
-        private readonly MemoryBlock _backingMemory;
         private readonly PageTable<ulong> _pageTable;
 
         private readonly MemoryEhMeilleure _memoryEh;
 
         private readonly ulong[] _pageBitmap;
 
+        /// <inheritdoc/>
+        public bool Supports4KBPages => MemoryBlock.GetPageSize() == PageSize;
+
         public int AddressSpaceBits { get; }
 
-        public IntPtr PageTablePointer => _addressSpace.Pointer;
+        public IntPtr PageTablePointer => _addressSpace.Base.Pointer;
 
         public MemoryManagerType Type => _unsafeMode ? MemoryManagerType.HostMappedUnsafe : MemoryManagerType.HostMapped;
 
@@ -67,7 +69,6 @@ namespace Ryujinx.Cpu.Jit
         /// <param name="invalidAccessHandler">Optional function to handle invalid memory accesses</param>
         public MemoryManagerHostMapped(MemoryBlock backingMemory, ulong addressSpaceSize, bool unsafeMode, InvalidAccessHandler invalidAccessHandler = null)
         {
-            _backingMemory = backingMemory;
             _pageTable = new PageTable<ulong>();
             _invalidAccessHandler = invalidAccessHandler;
             _unsafeMode = unsafeMode;
@@ -86,13 +87,10 @@ namespace Ryujinx.Cpu.Jit
 
             _pageBitmap = new ulong[1 << (AddressSpaceBits - (PageBits + PageToPteShift))];
 
-            MemoryAllocationFlags asFlags = MemoryAllocationFlags.Reserve | MemoryAllocationFlags.ViewCompatible;
+            _addressSpace = new AddressSpace(backingMemory, asSize, Supports4KBPages);
 
-            _addressSpace = new MemoryBlock(asSize, asFlags);
-            _addressSpaceMirror = new MemoryBlock(asSize, asFlags);
-
-            Tracking = new MemoryTracking(this, PageSize, invalidAccessHandler);
-            _memoryEh = new MemoryEhMeilleure(_addressSpace, _addressSpaceMirror, Tracking);
+            Tracking = new MemoryTracking(this, (int)MemoryBlock.GetPageSize(), invalidAccessHandler);
+            _memoryEh = new MemoryEhMeilleure(_addressSpace.Base, _addressSpace.Mirror, Tracking);
         }
 
         /// <summary>
@@ -145,18 +143,23 @@ namespace Ryujinx.Cpu.Jit
         }
 
         /// <inheritdoc/>
-        public void Map(ulong va, ulong pa, ulong size)
+        public void Map(ulong va, ulong pa, ulong size, MemoryMapFlags flags)
         {
             AssertValidAddressAndSize(va, size);
 
-            _addressSpace.MapView(_backingMemory, pa, va, size);
-            _addressSpaceMirror.MapView(_backingMemory, pa, va, size);
+            _addressSpace.Map(va, pa, size, flags);
             AddMapping(va, size);
             PtMap(va, pa, size);
 
             Tracking.Map(va, size);
         }
 
+        /// <inheritdoc/>
+        public void MapForeign(ulong va, nuint hostPointer, ulong size)
+        {
+            throw new NotSupportedException();
+        }
+
         /// <inheritdoc/>
         public void Unmap(ulong va, ulong size)
         {
@@ -167,8 +170,7 @@ namespace Ryujinx.Cpu.Jit
 
             RemoveMapping(va, size);
             PtUnmap(va, size);
-            _addressSpace.UnmapView(_backingMemory, va, size);
-            _addressSpaceMirror.UnmapView(_backingMemory, va, size);
+            _addressSpace.Unmap(va, size);
         }
 
         private void PtMap(ulong va, ulong pa, ulong size)
@@ -201,7 +203,7 @@ namespace Ryujinx.Cpu.Jit
             {
                 AssertMapped(va, (ulong)Unsafe.SizeOf<T>());
 
-                return _addressSpaceMirror.Read<T>(va);
+                return _addressSpace.Mirror.Read<T>(va);
             }
             catch (InvalidMemoryRegionException)
             {
@@ -241,7 +243,7 @@ namespace Ryujinx.Cpu.Jit
             {
                 AssertMapped(va, (ulong)data.Length);
 
-                _addressSpaceMirror.Read(va, data);
+                _addressSpace.Mirror.Read(va, data);
             }
             catch (InvalidMemoryRegionException)
             {
@@ -260,7 +262,7 @@ namespace Ryujinx.Cpu.Jit
             {
                 SignalMemoryTracking(va, (ulong)Unsafe.SizeOf<T>(), write: true);
 
-                _addressSpaceMirror.Write(va, value);
+                _addressSpace.Mirror.Write(va, value);
             }
             catch (InvalidMemoryRegionException)
             {
@@ -278,7 +280,7 @@ namespace Ryujinx.Cpu.Jit
             {
                 SignalMemoryTracking(va, (ulong)data.Length, write: true);
 
-                _addressSpaceMirror.Write(va, data);
+                _addressSpace.Mirror.Write(va, data);
             }
             catch (InvalidMemoryRegionException)
             {
@@ -296,7 +298,7 @@ namespace Ryujinx.Cpu.Jit
             {
                 AssertMapped(va, (ulong)data.Length);
 
-                _addressSpaceMirror.Write(va, data);
+                _addressSpace.Mirror.Write(va, data);
             }
             catch (InvalidMemoryRegionException)
             {
@@ -314,7 +316,7 @@ namespace Ryujinx.Cpu.Jit
             {
                 SignalMemoryTracking(va, (ulong)data.Length, false);
 
-                Span<byte> target = _addressSpaceMirror.GetSpan(va, data.Length);
+                Span<byte> target = _addressSpace.Mirror.GetSpan(va, data.Length);
                 bool changed = !data.SequenceEqual(target);
 
                 if (changed)
@@ -347,7 +349,7 @@ namespace Ryujinx.Cpu.Jit
                 AssertMapped(va, (ulong)size);
             }
 
-            return _addressSpaceMirror.GetSpan(va, size);
+            return _addressSpace.Mirror.GetSpan(va, size);
         }
 
         /// <inheritdoc/>
@@ -362,7 +364,7 @@ namespace Ryujinx.Cpu.Jit
                 AssertMapped(va, (ulong)size);
             }
 
-            return _addressSpaceMirror.GetWritableRegion(va, size);
+            return _addressSpace.Mirror.GetWritableRegion(va, size);
         }
 
         /// <inheritdoc/>
@@ -370,7 +372,7 @@ namespace Ryujinx.Cpu.Jit
         {
             SignalMemoryTracking(va, (ulong)Unsafe.SizeOf<T>(), true);
 
-            return ref _addressSpaceMirror.GetRef<T>(va);
+            return ref _addressSpace.Mirror.GetRef<T>(va);
         }
 
         /// <inheritdoc/>
@@ -454,6 +456,14 @@ namespace Ryujinx.Cpu.Jit
             return true;
         }
 
+        /// <inheritdoc/>
+        public IEnumerable<HostMemoryRange> GetHostRegions(ulong va, ulong size)
+        {
+            AssertValidAddressAndSize(va, size);
+
+            return Enumerable.Repeat(new HostMemoryRange((nuint)(ulong)_addressSpace.Mirror.GetPointer(va, size), size), 1);
+        }
+
         /// <inheritdoc/>
         public IEnumerable<MemoryRange> GetPhysicalRegions(ulong va, ulong size)
         {
@@ -692,7 +702,7 @@ namespace Ryujinx.Cpu.Jit
                 _ => MemoryPermission.None
             };
 
-            _addressSpace.Reprotect(va, size, protection, false);
+            _addressSpace.Base.Reprotect(va, size, protection, false);
         }
 
         /// <inheritdoc/>
@@ -799,7 +809,6 @@ namespace Ryujinx.Cpu.Jit
         protected override void Destroy()
         {
             _addressSpace.Dispose();
-            _addressSpaceMirror.Dispose();
             _memoryEh.Dispose();
         }
 

Ryujinx.Cpu/PrivateMemoryAllocation.cs

@@ -0,0 +1,41 @@
+using Ryujinx.Memory;
+using System;
+
+namespace Ryujinx.Cpu
+{
+    struct PrivateMemoryAllocation : IDisposable
+    {
+        private readonly PrivateMemoryAllocator _owner;
+        private readonly PrivateMemoryAllocator.Block _block;
+
+        public bool IsValid => _owner != null;
+        public MemoryBlock Memory => _block?.Memory;
+        public ulong Offset { get; }
+        public ulong Size { get; }
+
+        public PrivateMemoryAllocation(
+            PrivateMemoryAllocator owner,
+            PrivateMemoryAllocator.Block block,
+            ulong offset,
+            ulong size)
+        {
+            _owner = owner;
+            _block = block;
+            Offset = offset;
+            Size = size;
+        }
+
+        public (PrivateMemoryAllocation, PrivateMemoryAllocation) Split(ulong splitOffset)
+        {
+            PrivateMemoryAllocation left = new PrivateMemoryAllocation(_owner, _block, Offset, splitOffset);
+            PrivateMemoryAllocation right = new PrivateMemoryAllocation(_owner, _block, Offset + splitOffset, Size - splitOffset);
+
+            return (left, right);
+        }
+
+        public void Dispose()
+        {
+            _owner.Free(_block, Offset, Size);
+        }
+    }
+}

Ryujinx.Cpu/PrivateMemoryAllocator.cs

@@ -0,0 +1,268 @@
+using Ryujinx.Common;
+using Ryujinx.Memory;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+
+namespace Ryujinx.Cpu
+{
+    class PrivateMemoryAllocator : PrivateMemoryAllocatorImpl<PrivateMemoryAllocator.Block>
+    {
+        public const ulong InvalidOffset = ulong.MaxValue;
+
+        public class Block : IComparable<Block>
+        {
+            public MemoryBlock Memory { get; private set; }
+            public ulong Size { get; }
+
+            private struct Range : IComparable<Range>
+            {
+                public ulong Offset { get; }
+                public ulong Size { get; }
+
+                public Range(ulong offset, ulong size)
+                {
+                    Offset = offset;
+                    Size = size;
+                }
+
+                public int CompareTo(Range other)
+                {
+                    return Offset.CompareTo(other.Offset);
+                }
+            }
+
+            private readonly List<Range> _freeRanges;
+
+            public Block(MemoryBlock memory, ulong size)
+            {
+                Memory = memory;
+                Size = size;
+                _freeRanges = new List<Range>
+                {
+                    new Range(0, size)
+                };
+            }
+
+            public ulong Allocate(ulong size, ulong alignment)
+            {
+                for (int i = 0; i < _freeRanges.Count; i++)
+                {
+                    var range = _freeRanges[i];
+
+                    ulong alignedOffset = BitUtils.AlignUp(range.Offset, alignment);
+                    ulong sizeDelta = alignedOffset - range.Offset;
+                    ulong usableSize = range.Size - sizeDelta;
+
+                    if (sizeDelta < range.Size && usableSize >= size)
+                    {
+                        _freeRanges.RemoveAt(i);
+
+                        if (sizeDelta != 0)
+                        {
+                            InsertFreeRange(range.Offset, sizeDelta);
+                        }
+
+                        ulong endOffset = range.Offset + range.Size;
+                        ulong remainingSize = endOffset - (alignedOffset + size);
+                        if (remainingSize != 0)
+                        {
+                            InsertFreeRange(endOffset - remainingSize, remainingSize);
+                        }
+
+                        return alignedOffset;
+                    }
+                }
+
+                return InvalidOffset;
+            }
+
+            public void Free(ulong offset, ulong size)
+            {
+                InsertFreeRangeComingled(offset, size);
+            }
+
+            private void InsertFreeRange(ulong offset, ulong size)
+            {
+                var range = new Range(offset, size);
+                int index = _freeRanges.BinarySearch(range);
+                if (index < 0)
+                {
+                    index = ~index;
+                }
+
+                _freeRanges.Insert(index, range);
+            }
+
+            private void InsertFreeRangeComingled(ulong offset, ulong size)
+            {
+                ulong endOffset = offset + size;
+                var range = new Range(offset, size);
+                int index = _freeRanges.BinarySearch(range);
+                if (index < 0)
+                {
+                    index = ~index;
+                }
+
+                if (index < _freeRanges.Count && _freeRanges[index].Offset == endOffset)
+                {
+                    endOffset = _freeRanges[index].Offset + _freeRanges[index].Size;
+                    _freeRanges.RemoveAt(index);
+                }
+
+                if (index > 0 && _freeRanges[index - 1].Offset + _freeRanges[index - 1].Size == offset)
+                {
+                    offset = _freeRanges[index - 1].Offset;
+                    _freeRanges.RemoveAt(--index);
+                }
+
+                range = new Range(offset, endOffset - offset);
+
+                _freeRanges.Insert(index, range);
+            }
+
+            public bool IsTotallyFree()
+            {
+                if (_freeRanges.Count == 1 && _freeRanges[0].Size == Size)
+                {
+                    Debug.Assert(_freeRanges[0].Offset == 0);
+                    return true;
+                }
+
+                return false;
+            }
+
+            public int CompareTo(Block other)
+            {
+                return Size.CompareTo(other.Size);
+            }
+
+            public virtual void Destroy()
+            {
+                Memory.Dispose();
+            }
+        }
+
+        public PrivateMemoryAllocator(int blockAlignment, MemoryAllocationFlags allocationFlags) : base(blockAlignment, allocationFlags)
+        {
+        }
+
+        public PrivateMemoryAllocation Allocate(ulong size, ulong alignment)
+        {
+            var allocation = Allocate(size, alignment, CreateBlock);
+
+            return new PrivateMemoryAllocation(this, allocation.Block, allocation.Offset, allocation.Size);
+        }
+
+        private Block CreateBlock(MemoryBlock memory, ulong size)
+        {
+            return new Block(memory, size);
+        }
+    }
+
+    class PrivateMemoryAllocatorImpl<T> : IDisposable where T : PrivateMemoryAllocator.Block
+    {
+        private const ulong InvalidOffset = ulong.MaxValue;
+
+        public struct Allocation
+        {
+            public T Block { get; }
+            public ulong Offset { get; }
+            public ulong Size { get; }
+
+            public Allocation(T block, ulong offset, ulong size)
+            {
+                Block = block;
+                Offset = offset;
+                Size = size;
+            }
+        }
+
+        private readonly List<T> _blocks;
+
+        private readonly int _blockAlignment;
+        private readonly MemoryAllocationFlags _allocationFlags;
+
+        public PrivateMemoryAllocatorImpl(int blockAlignment, MemoryAllocationFlags allocationFlags)
+        {
+            _blocks = new List<T>();
+            _blockAlignment = blockAlignment;
+            _allocationFlags = allocationFlags;
+        }
+
+        protected Allocation Allocate(ulong size, ulong alignment, Func<MemoryBlock, ulong, T> createBlock)
+        {
+            // Ensure we have a sane alignment value.
+            if ((ulong)(int)alignment != alignment || (int)alignment <= 0)
+            {
+                throw new ArgumentOutOfRangeException(nameof(alignment), $"Invalid alignment 0x{alignment:X}.");
+            }
+
+            for (int i = 0; i < _blocks.Count; i++)
+            {
+                var block = _blocks[i];
+
+                if (block.Size >= size)
+                {
+                    ulong offset = block.Allocate(size, alignment);
+                    if (offset != InvalidOffset)
+                    {
+                        return new Allocation(block, offset, size);
+                    }
+                }
+            }
+
+            ulong blockAlignedSize = BitUtils.AlignUp(size, (ulong)_blockAlignment);
+
+            var memory = new MemoryBlock(blockAlignedSize, _allocationFlags);
+            var newBlock = createBlock(memory, blockAlignedSize);
+
+            InsertBlock(newBlock);
+
+            ulong newBlockOffset = newBlock.Allocate(size, alignment);
+            Debug.Assert(newBlockOffset != InvalidOffset);
+
+            return new Allocation(newBlock, newBlockOffset, size);
+        }
+
+        public void Free(PrivateMemoryAllocator.Block block, ulong offset, ulong size)
+        {
+            block.Free(offset, size);
+
+            if (block.IsTotallyFree())
+            {
+                for (int i = 0; i < _blocks.Count; i++)
+                {
+                    if (_blocks[i] == block)
+                    {
+                        _blocks.RemoveAt(i);
+                        break;
+                    }
+                }
+
+                block.Destroy();
+            }
+        }
+
+        private void InsertBlock(T block)
+        {
+            int index = _blocks.BinarySearch(block);
+            if (index < 0)
+            {
+                index = ~index;
+            }
+
+            _blocks.Insert(index, block);
+        }
+
+        public void Dispose()
+        {
+            for (int i = 0; i < _blocks.Count; i++)
+            {
+                _blocks[i].Destroy();
+            }
+
+            _blocks.Clear();
+        }
+    }
+}

Ryujinx.Graphics.Gpu/Image/TextureGroup.cs

@@ -1420,6 +1420,14 @@ namespace Ryujinx.Graphics.Gpu.Image
         /// <param name="size">The size of the flushing memory access</param>
         public void FlushAction(TextureGroupHandle handle, ulong address, ulong size)
         {
+            // If the page size is larger than 4KB, we will have a lot of false positives for flushing.
+            // Let's avoid flushing textures that are unlikely to be read from CPU to improve performance
+            // on those platforms.
+            if (!_physicalMemory.Supports4KBPages && !Storage.Info.IsLinear && !_context.IsGpuThread())
+            {
+                return;
+            }
+
             // There is a small gap here where the action is removed but _actionRegistered is still 1.
             // In this case it will skip registering the action, but here we are already handling it,
             // so there shouldn't be any issue as it's the same handler for all actions.

Ryujinx.Graphics.Gpu/Memory/Buffer.cs

@@ -470,19 +470,16 @@ namespace Ryujinx.Graphics.Gpu.Memory
                 return false;
             }
 
-            if (address < Address)
-            {
-                address = Address;
-            }
+            ulong maxAddress = Math.Max(address, Address);
+            ulong minEndAddress = Math.Min(address + size, Address + Size);
 
-            ulong maxSize = Address + Size - address;
-
-            if (size > maxSize)
+            if (maxAddress >= minEndAddress)
             {
-                size = maxSize;
+                // Access doesn't overlap.
+                return false;
             }
 
-            ForceDirty(address, size);
+            ForceDirty(maxAddress, minEndAddress - maxAddress);
 
             return true;
         }

Ryujinx.Graphics.Gpu/Memory/PhysicalMemory.cs

@@ -21,6 +21,11 @@ namespace Ryujinx.Graphics.Gpu.Memory
         private IVirtualMemoryManagerTracked _cpuMemory;
         private int _referenceCount;
 
+        /// <summary>
+        /// Indicates whenever the memory manager supports 4KB pages.
+        /// </summary>
+        public bool Supports4KBPages => _cpuMemory.Supports4KBPages;
+
         /// <summary>
         /// In-memory shader cache.
         /// </summary>

Ryujinx.HLE/HOS/Kernel/KernelContext.cs

@@ -84,7 +84,7 @@ namespace Ryujinx.HLE.HOS.Kernel
                 KernelConstants.UserSlabHeapItemSize,
                 KernelConstants.UserSlabHeapSize);
 
-            memory.Commit(KernelConstants.UserSlabHeapBase - DramMemoryMap.DramBase, KernelConstants.UserSlabHeapSize);
+            CommitMemory(KernelConstants.UserSlabHeapBase - DramMemoryMap.DramBase, KernelConstants.UserSlabHeapSize);
 
             CriticalSection = new KCriticalSection(this);
             Schedulers = new KScheduler[KScheduler.CpuCoresCount];
@@ -119,6 +119,17 @@ namespace Ryujinx.HLE.HOS.Kernel
             new Thread(PreemptionThreadStart) { Name = "HLE.PreemptionThread" }.Start();
         }
 
+        public void CommitMemory(ulong address, ulong size)
+        {
+            ulong alignment = MemoryBlock.GetPageSize();
+            ulong endAddress = address + size;
+
+            address &= ~(alignment - 1);
+            endAddress = (endAddress + (alignment - 1)) & ~(alignment - 1);
+
+            Memory.Commit(address, endAddress - address);
+        }
+
         public ulong NewThreadUid()
         {
             return Interlocked.Increment(ref _threadUid) - 1;

Ryujinx.HLE/HOS/Kernel/Memory/KMemoryRegionManager.cs

@@ -64,7 +64,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
                 if (address != 0)
                 {
                     IncrementPagesReferenceCount(address, pagesCount);
-                    context.Memory.Commit(address - DramMemoryMap.DramBase, pagesCount * KPageTableBase.PageSize);
+                    context.CommitMemory(address - DramMemoryMap.DramBase, pagesCount * KPageTableBase.PageSize);
                 }
 
                 return address;

Ryujinx.HLE/HOS/Kernel/Memory/KPageTable.cs

@@ -1,6 +1,8 @@
 using Ryujinx.Horizon.Common;
 using Ryujinx.Memory;
+using Ryujinx.Memory.Range;
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 
 namespace Ryujinx.HLE.HOS.Kernel.Memory
@@ -9,11 +11,19 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
     {
         private readonly IVirtualMemoryManager _cpuMemory;
 
+        protected override bool Supports4KBPages => _cpuMemory.Supports4KBPages;
+
         public KPageTable(KernelContext context, IVirtualMemoryManager cpuMemory) : base(context)
         {
             _cpuMemory = cpuMemory;
         }
 
+        /// <inheritdoc/>
+        protected override IEnumerable<HostMemoryRange> GetHostRegions(ulong va, ulong size)
+        {
+            return _cpuMemory.GetHostRegions(va, size);
+        }
+
         /// <inheritdoc/>
         protected override void GetPhysicalRegions(ulong va, ulong size, KPageList pageList)
         {
@@ -43,7 +53,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
                 return result;
             }
 
-            result = MapPages(dst, pageList, newDstPermission, false, 0);
+            result = MapPages(dst, pageList, newDstPermission, MemoryMapFlags.Private, false, 0);
 
             if (result != Result.Success)
             {
@@ -81,7 +91,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
 
             if (result != Result.Success)
             {
-                Result mapResult = MapPages(dst, dstPageList, oldDstPermission, false, 0);
+                Result mapResult = MapPages(dst, dstPageList, oldDstPermission, MemoryMapFlags.Private, false, 0);
                 Debug.Assert(mapResult == Result.Success);
             }
 
@@ -89,13 +99,20 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
         }
 
         /// <inheritdoc/>
-        protected override Result MapPages(ulong dstVa, ulong pagesCount, ulong srcPa, KMemoryPermission permission, bool shouldFillPages, byte fillValue)
+        protected override Result MapPages(
+            ulong dstVa,
+            ulong pagesCount,
+            ulong srcPa,
+            KMemoryPermission permission,
+            MemoryMapFlags flags,
+            bool shouldFillPages,
+            byte fillValue)
         {
             ulong size = pagesCount * PageSize;
 
-            Context.Memory.Commit(srcPa - DramMemoryMap.DramBase, size);
+            Context.CommitMemory(srcPa - DramMemoryMap.DramBase, size);
 
-            _cpuMemory.Map(dstVa, srcPa - DramMemoryMap.DramBase, size);
+            _cpuMemory.Map(dstVa, srcPa - DramMemoryMap.DramBase, size, flags);
 
             if (DramMemoryMap.IsHeapPhysicalAddress(srcPa))
             {
@@ -111,7 +128,13 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
         }
 
         /// <inheritdoc/>
-        protected override Result MapPages(ulong address, KPageList pageList, KMemoryPermission permission, bool shouldFillPages, byte fillValue)
+        protected override Result MapPages(
+            ulong address,
+            KPageList pageList,
+            KMemoryPermission permission,
+            MemoryMapFlags flags,
+            bool shouldFillPages,
+            byte fillValue)
         {
             using var scopedPageList = new KScopedPageList(Context.MemoryManager, pageList);
 
@@ -122,9 +145,9 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
                 ulong addr = pageNode.Address - DramMemoryMap.DramBase;
                 ulong size = pageNode.PagesCount * PageSize;
 
-                Context.Memory.Commit(addr, size);
+                Context.CommitMemory(addr, size);
 
-                _cpuMemory.Map(currentVa, addr, size);
+                _cpuMemory.Map(currentVa, addr, size, flags);
 
                 if (shouldFillPages)
                 {
@@ -139,6 +162,21 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
             return Result.Success;
         }
 
+        /// <inheritdoc/>
+        protected override Result MapForeign(IEnumerable<HostMemoryRange> regions, ulong va, ulong size)
+        {
+            ulong offset = 0;
+
+            foreach (var region in regions)
+            {
+                _cpuMemory.MapForeign(va + offset, region.Address, region.Size);
+
+                offset += region.Size;
+            }
+
+            return Result.Success;
+        }
+
         /// <inheritdoc/>
         protected override Result Unmap(ulong address, ulong pagesCount)
         {
@@ -188,4 +226,4 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
             _cpuMemory.Write(va, data);
         }
     }
-}
+}

Ryujinx.HLE/HOS/Kernel/Memory/KPageTableBase.cs

@@ -1,6 +1,8 @@
 using Ryujinx.Common;
 using Ryujinx.HLE.HOS.Kernel.Common;
 using Ryujinx.HLE.HOS.Kernel.Process;
+using Ryujinx.Memory;
+using Ryujinx.Memory.Range;
 using Ryujinx.Horizon.Common;
 using System;
 using System.Collections.Generic;
@@ -29,6 +31,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
         private const int MaxBlocksNeededForInsertion = 2;
 
         protected readonly KernelContext Context;
+        protected virtual bool Supports4KBPages => true;
 
         public ulong AddrSpaceStart { get; private set; }
         public ulong AddrSpaceEnd { get; private set; }
@@ -366,7 +369,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
                     return KernelResult.OutOfResource;
                 }
 
-                Result result = MapPages(address, pageList, permission);
+                Result result = MapPages(address, pageList, permission, MemoryMapFlags.None);
 
                 if (result == Result.Success)
                 {
@@ -502,7 +505,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
 
                 if (paIsValid)
                 {
-                    result = MapPages(address, pagesCount, srcPa, permission);
+                    result = MapPages(address, pagesCount, srcPa, permission, MemoryMapFlags.Private);
                 }
                 else
                 {
@@ -565,7 +568,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
 
             using var _ = new OnScopeExit(() => pageList.DecrementPagesReferenceCount(Context.MemoryManager));
 
-            return MapPages(address, pageList, permission);
+            return MapPages(address, pageList, permission, MemoryMapFlags.Private);
         }
 
         public Result MapProcessCodeMemory(ulong dst, ulong src, ulong size)
@@ -746,7 +749,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
                         return KernelResult.InvalidMemState;
                     }
 
-                    result = MapPages(_currentHeapAddr, pageList, KMemoryPermission.ReadAndWrite, true, (byte)_heapFillValue);
+                    result = MapPages(_currentHeapAddr, pageList, KMemoryPermission.ReadAndWrite, MemoryMapFlags.Private, true, (byte)_heapFillValue);
 
                     if (result != Result.Success)
                     {
@@ -1334,7 +1337,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
 
                         ulong currentPagesCount = Math.Min(srcPaPages, dstVaPages);
 
-                        MapPages(dstVa, currentPagesCount, srcPa, KMemoryPermission.ReadAndWrite);
+                        MapPages(dstVa, currentPagesCount, srcPa, KMemoryPermission.ReadAndWrite, MemoryMapFlags.Private);
 
                         dstVa += currentPagesCount * PageSize;
                         srcPa += currentPagesCount * PageSize;
@@ -1878,7 +1881,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
                     Context.Memory.Fill(GetDramAddressFromPa(firstPageFillAddress), unusedSizeAfter, (byte)_ipcFillValue);
                 }
 
-                Result result = MapPages(currentVa, 1, dstFirstPagePa, permission);
+                Result result = MapPages(currentVa, 1, dstFirstPagePa, permission, MemoryMapFlags.Private);
 
                 if (result != Result.Success)
                 {
@@ -1894,10 +1897,19 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
             {
                 ulong alignedSize = endAddrTruncated - addressRounded;
 
-                KPageList pageList = new KPageList();
-                srcPageTable.GetPhysicalRegions(addressRounded, alignedSize, pageList);
+                Result result;
+
+                if (srcPageTable.Supports4KBPages)
+                {
+                    KPageList pageList = new KPageList();
+                    srcPageTable.GetPhysicalRegions(addressRounded, alignedSize, pageList);
 
-                Result result = MapPages(currentVa, pageList, permission);
+                    result = MapPages(currentVa, pageList, permission, MemoryMapFlags.None);
+                }
+                else
+                {
+                    result = MapForeign(srcPageTable.GetHostRegions(addressRounded, alignedSize), currentVa, alignedSize);
+                }
 
                 if (result != Result.Success)
                 {
@@ -1932,7 +1944,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
 
                 Context.Memory.Fill(GetDramAddressFromPa(lastPageFillAddr), unusedSizeAfter, (byte)_ipcFillValue);
 
-                Result result = MapPages(currentVa, 1, dstLastPagePa, permission);
+                Result result = MapPages(currentVa, 1, dstLastPagePa, permission, MemoryMapFlags.Private);
 
                 if (result != Result.Success)
                 {
@@ -2884,6 +2896,16 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
             return StackRegionStart > address || address + size - 1 > StackRegionEnd - 1;
         }
 
+        /// <summary>
+        /// Gets the host regions that make up the given virtual address region.
+        /// If any part of the virtual region is unmapped, null is returned.
+        /// </summary>
+        /// <param name="va">Virtual address of the range</param>
+        /// <param name="size">Size of the range</param>
+        /// <returns>The host regions</returns>
+        /// <exception cref="Ryujinx.Memory.InvalidMemoryRegionException">Throw for unhandled invalid or unmapped memory accesses</exception>
+        protected abstract IEnumerable<HostMemoryRange> GetHostRegions(ulong va, ulong size);
+
         /// <summary>
         /// Gets the physical regions that make up the given virtual address region.
         /// If any part of the virtual region is unmapped, null is returned.
@@ -2936,10 +2958,18 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
         /// <param name="pagesCount">Number of pages to map</param>
         /// <param name="srcPa">Physical address where the pages should be mapped. May be ignored if aliasing is not supported</param>
         /// <param name="permission">Permission of the region to be mapped</param>
+        /// <param name="flags">Flags controlling the memory map operation</param>
         /// <param name="shouldFillPages">Indicate if the pages should be filled with the <paramref name="fillValue"/> value</param>
         /// <param name="fillValue">The value used to fill pages when <paramref name="shouldFillPages"/> is set to true</param>
         /// <returns>Result of the mapping operation</returns>
-        protected abstract Result MapPages(ulong dstVa, ulong pagesCount, ulong srcPa, KMemoryPermission permission, bool shouldFillPages = false, byte fillValue = 0);
+        protected abstract Result MapPages(
+            ulong dstVa,
+            ulong pagesCount,
+            ulong srcPa,
+            KMemoryPermission permission,
+            MemoryMapFlags flags,
+            bool shouldFillPages = false,
+            byte fillValue = 0);
 
         /// <summary>
         /// Maps a region of memory into the specified physical memory region.
@@ -2947,10 +2977,26 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
         /// <param name="address">Destination virtual address that should be mapped</param>
         /// <param name="pageList">List of physical memory pages where the pages should be mapped. May be ignored if aliasing is not supported</param>
         /// <param name="permission">Permission of the region to be mapped</param>
+        /// <param name="flags">Flags controlling the memory map operation</param>
         /// <param name="shouldFillPages">Indicate if the pages should be filled with the <paramref name="fillValue"/> value</param>
         /// <param name="fillValue">The value used to fill pages when <paramref name="shouldFillPages"/> is set to true</param>
         /// <returns>Result of the mapping operation</returns>
-        protected abstract Result MapPages(ulong address, KPageList pageList, KMemoryPermission permission, bool shouldFillPages = false, byte fillValue = 0);
+        protected abstract Result MapPages(
+            ulong address,
+            KPageList pageList,
+            KMemoryPermission permission,
+            MemoryMapFlags flags,
+            bool shouldFillPages = false,
+            byte fillValue = 0);
+
+        /// <summary>
+        /// Maps pages into an arbitrary host memory location.
+        /// </summary>
+        /// <param name="regions">Host regions to be mapped into the specified virtual memory region</param>
+        /// <param name="va">Destination virtual address of the range on this page table</param>
+        /// <param name="size">Size of the range</param>
+        /// <returns>Result of the mapping operation</returns>
+        protected abstract Result MapForeign(IEnumerable<HostMemoryRange> regions, ulong va, ulong size);
 
         /// <summary>
         /// Unmaps a region of memory that was previously mapped with one of the page mapping methods.

Ryujinx.HLE/HOS/Kernel/Memory/KSharedMemory.cs

@@ -2,6 +2,7 @@ using Ryujinx.Common;
 using Ryujinx.HLE.HOS.Kernel.Common;
 using Ryujinx.HLE.HOS.Kernel.Process;
 using Ryujinx.Horizon.Common;
+using Ryujinx.Memory;
 
 namespace Ryujinx.HLE.HOS.Kernel.Memory
 {
@@ -48,7 +49,17 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
                 return KernelResult.InvalidPermission;
             }
 
-            return memoryManager.MapPages(address, _pageList, MemoryState.SharedMemory, permission);
+            // On platforms with page size > 4 KB, this can fail due to the address not being page aligned,
+            // we can return an error to force the application to retry with a different address.
+
+            try
+            {
+                return memoryManager.MapPages(address, _pageList, MemoryState.SharedMemory, permission);
+            }
+            catch (InvalidMemoryRegionException)
+            {
+                return KernelResult.InvalidMemState;
+            }
         }
 
         public Result UnmapFromProcess(KPageTableBase memoryManager, ulong address, ulong size, KProcess process)

Ryujinx.HLE/HOS/Kernel/Memory/SharedMemoryStorage.cs

@@ -18,7 +18,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
             {
                 ulong address = pageNode.Address - DramMemoryMap.DramBase;
                 ulong size = pageNode.PagesCount * KPageTableBase.PageSize;
-                context.Memory.Commit(address, size);
+                context.CommitMemory(address, size);
             }
         }
 

Ryujinx.Memory.Tests/MockVirtualMemoryManager.cs

@@ -6,6 +6,8 @@ namespace Ryujinx.Memory.Tests
 {
     public class MockVirtualMemoryManager : IVirtualMemoryManager
     {
+        public bool Supports4KBPages => true;
+
         public bool NoMappings = false;
 
         public event Action<ulong, ulong, MemoryPermission> OnProtect;
@@ -14,7 +16,12 @@ namespace Ryujinx.Memory.Tests
         {
         }
 
-        public void Map(ulong va, ulong pa, ulong size)
+        public void Map(ulong va, ulong pa, ulong size, MemoryMapFlags flags)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void MapForeign(ulong va, nuint hostAddress, ulong size)
         {
             throw new NotImplementedException();
         }
@@ -64,6 +71,11 @@ namespace Ryujinx.Memory.Tests
             throw new NotImplementedException();
         }
 
+        IEnumerable<HostMemoryRange> IVirtualMemoryManager.GetHostRegions(ulong va, ulong size)
+        {
+            throw new NotImplementedException();
+        }
+
         IEnumerable<MemoryRange> IVirtualMemoryManager.GetPhysicalRegions(ulong va, ulong size)
         {
             return NoMappings ? new MemoryRange[0] : new MemoryRange[] { new MemoryRange(va, size) };

Ryujinx.Memory/AddressSpaceManager.cs

@@ -13,9 +13,12 @@ namespace Ryujinx.Memory
     /// </summary>
     public sealed class AddressSpaceManager : IVirtualMemoryManager, IWritableBlock
     {
-        public const int PageBits = PageTable<ulong>.PageBits;
-        public const int PageSize = PageTable<ulong>.PageSize;
-        public const int PageMask = PageTable<ulong>.PageMask;
+        public const int PageBits = PageTable<nuint>.PageBits;
+        public const int PageSize = PageTable<nuint>.PageSize;
+        public const int PageMask = PageTable<nuint>.PageMask;
+
+        /// <inheritdoc/>
+        public bool Supports4KBPages => true;
 
         /// <summary>
         /// Address space width in bits.
@@ -25,7 +28,7 @@ namespace Ryujinx.Memory
         private readonly ulong _addressSpaceSize;
 
         private readonly MemoryBlock _backingMemory;
-        private readonly PageTable<ulong> _pageTable;
+        private readonly PageTable<nuint> _pageTable;
 
         /// <summary>
         /// Creates a new instance of the memory manager.
@@ -46,17 +49,17 @@ namespace Ryujinx.Memory
             AddressSpaceBits = asBits;
             _addressSpaceSize = asSize;
             _backingMemory = backingMemory;
-            _pageTable = new PageTable<ulong>();
+            _pageTable = new PageTable<nuint>();
         }
 
         /// <inheritdoc/>
-        public void Map(ulong va, ulong pa, ulong size)
+        public void Map(ulong va, ulong pa, ulong size, MemoryMapFlags flags)
         {
             AssertValidAddressAndSize(va, size);
 
             while (size != 0)
             {
-                _pageTable.Map(va, pa);
+                _pageTable.Map(va, (nuint)(ulong)_backingMemory.GetPointer(pa, PageSize));
 
                 va += PageSize;
                 pa += PageSize;
@@ -64,6 +67,21 @@ namespace Ryujinx.Memory
             }
         }
 
+        /// <inheritdoc/>
+        public void MapForeign(ulong va, nuint hostPointer, ulong size)
+        {
+            AssertValidAddressAndSize(va, size);
+
+            while (size != 0)
+            {
+                _pageTable.Map(va, hostPointer);
+
+                va += PageSize;
+                hostPointer += PageSize;
+                size -= PageSize;
+            }
+        }
+
         /// <inheritdoc/>
         public void Unmap(ulong va, ulong size)
         {
@@ -108,7 +126,7 @@ namespace Ryujinx.Memory
 
             if (IsContiguousAndMapped(va, data.Length))
             {
-                data.CopyTo(_backingMemory.GetSpan(GetPhysicalAddressInternal(va), data.Length));
+                data.CopyTo(GetHostSpanContiguous(va, data.Length));
             }
             else
             {
@@ -116,22 +134,18 @@ namespace Ryujinx.Memory
 
                 if ((va & PageMask) != 0)
                 {
-                    ulong pa = GetPhysicalAddressInternal(va);
-
                     size = Math.Min(data.Length, PageSize - (int)(va & PageMask));
 
-                    data.Slice(0, size).CopyTo(_backingMemory.GetSpan(pa, size));
+                    data.Slice(0, size).CopyTo(GetHostSpanContiguous(va, size));
 
                     offset += size;
                 }
 
                 for (; offset < data.Length; offset += size)
                 {
-                    ulong pa = GetPhysicalAddressInternal(va + (ulong)offset);
-
                     size = Math.Min(data.Length - offset, PageSize);
 
-                    data.Slice(offset, size).CopyTo(_backingMemory.GetSpan(pa, size));
+                    data.Slice(offset, size).CopyTo(GetHostSpanContiguous(va + (ulong)offset, size));
                 }
             }
         }
@@ -154,7 +168,7 @@ namespace Ryujinx.Memory
 
             if (IsContiguousAndMapped(va, size))
             {
-                return _backingMemory.GetSpan(GetPhysicalAddressInternal(va), size);
+                return GetHostSpanContiguous(va, size);
             }
             else
             {
@@ -176,7 +190,7 @@ namespace Ryujinx.Memory
 
             if (IsContiguousAndMapped(va, size))
             {
-                return new WritableRegion(null, va, _backingMemory.GetMemory(GetPhysicalAddressInternal(va), size));
+                return new WritableRegion(null, va, new NativeMemoryManager<byte>((byte*)GetHostAddress(va), size).Memory);
             }
             else
             {
@@ -189,14 +203,14 @@ namespace Ryujinx.Memory
         }
 
         /// <inheritdoc/>
-        public ref T GetRef<T>(ulong va) where T : unmanaged
+        public unsafe ref T GetRef<T>(ulong va) where T : unmanaged
         {
             if (!IsContiguous(va, Unsafe.SizeOf<T>()))
             {
                 ThrowMemoryNotContiguous();
             }
 
-            return ref _backingMemory.GetRef<T>(GetPhysicalAddressInternal(va));
+            return ref *(T*)GetHostAddress(va);
         }
 
         /// <inheritdoc/>
@@ -210,7 +224,7 @@ namespace Ryujinx.Memory
             return (int)(vaSpan / PageSize);
         }
 
-        private static void ThrowMemoryNotContiguous() => throw new MemoryNotContiguousException();
+        private void ThrowMemoryNotContiguous() => throw new MemoryNotContiguousException();
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         private bool IsContiguousAndMapped(ulong va, int size) => IsContiguous(va, size) && IsMapped(va);
@@ -232,7 +246,7 @@ namespace Ryujinx.Memory
                     return false;
                 }
 
-                if (GetPhysicalAddressInternal(va) + PageSize != GetPhysicalAddressInternal(va + PageSize))
+                if (GetHostAddress(va) + PageSize != GetHostAddress(va + PageSize))
                 {
                     return false;
                 }
@@ -243,6 +257,17 @@ namespace Ryujinx.Memory
             return true;
         }
 
+        /// <inheritdoc/>
+        public IEnumerable<HostMemoryRange> GetHostRegions(ulong va, ulong size)
+        {
+            if (size == 0)
+            {
+                return Enumerable.Empty<HostMemoryRange>();
+            }
+
+            return GetHostRegionsImpl(va, size);
+        }
+
         /// <inheritdoc/>
         public IEnumerable<MemoryRange> GetPhysicalRegions(ulong va, ulong size)
         {
@@ -251,6 +276,39 @@ namespace Ryujinx.Memory
                 return Enumerable.Empty<MemoryRange>();
             }
 
+            var hostRegions = GetHostRegionsImpl(va, size);
+            if (hostRegions == null)
+            {
+                return null;
+            }
+
+            var regions = new MemoryRange[hostRegions.Count];
+
+            ulong backingStart = (ulong)_backingMemory.Pointer;
+            ulong backingEnd = backingStart + _backingMemory.Size;
+
+            int count = 0;
+
+            for (int i = 0; i < regions.Length; i++)
+            {
+                var hostRegion = hostRegions[i];
+
+                if ((ulong)hostRegion.Address >= backingStart && (ulong)hostRegion.Address < backingEnd)
+                {
+                    regions[count++] = new MemoryRange((ulong)hostRegion.Address - backingStart, hostRegion.Size);
+                }
+            }
+
+            if (count != regions.Length)
+            {
+                return new ArraySegment<MemoryRange>(regions, 0, count);
+            }
+
+            return regions;
+        }
+
+        private List<HostMemoryRange> GetHostRegionsImpl(ulong va, ulong size)
+        {
             if (!ValidateAddress(va) || !ValidateAddressAndSize(va, size))
             {
                 return null;
@@ -258,9 +316,9 @@ namespace Ryujinx.Memory
 
             int pages = GetPagesCount(va, (uint)size, out va);
 
-            var regions = new List<MemoryRange>();
+            var regions = new List<HostMemoryRange>();
 
-            ulong regionStart = GetPhysicalAddressInternal(va);
+            nuint regionStart = GetHostAddress(va);
             ulong regionSize = PageSize;
 
             for (int page = 0; page < pages - 1; page++)
@@ -270,12 +328,12 @@ namespace Ryujinx.Memory
                     return null;
                 }
 
-                ulong newPa = GetPhysicalAddressInternal(va + PageSize);
+                nuint newHostAddress = GetHostAddress(va + PageSize);
 
-                if (GetPhysicalAddressInternal(va) + PageSize != newPa)
+                if (GetHostAddress(va) + PageSize != newHostAddress)
                 {
-                    regions.Add(new MemoryRange(regionStart, regionSize));
-                    regionStart = newPa;
+                    regions.Add(new HostMemoryRange(regionStart, regionSize));
+                    regionStart = newHostAddress;
                     regionSize = 0;
                 }
 
@@ -283,7 +341,7 @@ namespace Ryujinx.Memory
                 regionSize += PageSize;
             }
 
-            regions.Add(new MemoryRange(regionStart, regionSize));
+            regions.Add(new HostMemoryRange(regionStart, regionSize));
 
             return regions;
         }
@@ -301,22 +359,18 @@ namespace Ryujinx.Memory
 
             if ((va & PageMask) != 0)
             {
-                ulong pa = GetPhysicalAddressInternal(va);
-
                 size = Math.Min(data.Length, PageSize - (int)(va & PageMask));
 
-                _backingMemory.GetSpan(pa, size).CopyTo(data.Slice(0, size));
+                GetHostSpanContiguous(va, size).CopyTo(data.Slice(0, size));
 
                 offset += size;
             }
 
             for (; offset < data.Length; offset += size)
             {
-                ulong pa = GetPhysicalAddressInternal(va + (ulong)offset);
-
                 size = Math.Min(data.Length - offset, PageSize);
 
-                _backingMemory.GetSpan(pa, size).CopyTo(data.Slice(offset, size));
+                GetHostSpanContiguous(va + (ulong)offset, size).CopyTo(data.Slice(offset, size));
             }
         }
 
@@ -391,22 +445,23 @@ namespace Ryujinx.Memory
             }
         }
 
-        private ulong GetPhysicalAddressInternal(ulong va)
+        private unsafe Span<byte> GetHostSpanContiguous(ulong va, int size)
         {
-            return _pageTable.Read(va) + (va & PageMask);
+            return new Span<byte>((void*)GetHostAddress(va), size);
         }
 
-        /// <summary>
-        /// Reprotect a region of virtual memory for tracking. Sets software protection bits.
-        /// </summary>
-        /// <param name="va">Virtual address base</param>
-        /// <param name="size">Size of the region to protect</param>
-        /// <param name="protection">Memory protection to set</param>
+        private nuint GetHostAddress(ulong va)
+        {
+            return _pageTable.Read(va) + (nuint)(va & PageMask);
+        }
+
+        /// <inheritdoc/>
         public void TrackingReprotect(ulong va, ulong size, MemoryPermission protection)
         {
             throw new NotImplementedException();
         }
 
+        /// <inheritdoc/>
         public void SignalMemoryTracking(ulong va, ulong size, bool write, bool precise = false)
         {
             // Only the ARM Memory Manager has tracking for now.

Ryujinx.Memory/IVirtualMemoryManager.cs

@@ -6,6 +6,12 @@ namespace Ryujinx.Memory
 {
     public interface IVirtualMemoryManager
     {
+        /// <summary>
+        /// Indicates whenever the memory manager supports aliasing pages at 4KB granularity.
+        /// </summary>
+        /// <returns>True if 4KB pages are supported by the memory manager, false otherwise</returns>
+        bool Supports4KBPages { get; }
+
         /// <summary>
         /// Maps a virtual memory range into a physical memory range.
         /// </summary>
@@ -15,7 +21,20 @@ namespace Ryujinx.Memory
         /// <param name="va">Virtual memory address</param>
         /// <param name="pa">Physical memory address where the region should be mapped to</param>
         /// <param name="size">Size to be mapped</param>
-        void Map(ulong va, ulong pa, ulong size);
+        /// <param name="flags">Flags controlling memory mapping</param>
+        void Map(ulong va, ulong pa, ulong size, MemoryMapFlags flags);
+
+        /// <summary>
+        /// Maps a virtual memory range into an arbitrary host memory range.
+        /// </summary>
+        /// <remarks>
+        /// Addresses and size must be page aligned.
+        /// Not all memory managers supports this feature.
+        /// </remarks>
+        /// <param name="va">Virtual memory address</param>
+        /// <param name="hostPointer">Host pointer where the virtual region should be mapped</param>
+        /// <param name="size">Size to be mapped</param>
+        void MapForeign(ulong va, nuint hostPointer, ulong size);
 
         /// <summary>
         /// Unmaps a previously mapped range of virtual memory.
@@ -115,6 +134,15 @@ namespace Ryujinx.Memory
         /// <exception cref="MemoryNotContiguousException">Throw if the specified memory region is not contiguous in physical memory</exception>
         ref T GetRef<T>(ulong va) where T : unmanaged;
 
+        /// <summary>
+        /// Gets the host regions that make up the given virtual address region.
+        /// If any part of the virtual region is unmapped, null is returned.
+        /// </summary>
+        /// <param name="va">Virtual address of the range</param>
+        /// <param name="size">Size of the range</param>
+        /// <returns>Array of host regions</returns>
+        IEnumerable<HostMemoryRange> GetHostRegions(ulong va, ulong size);
+
         /// <summary>
         /// Gets the physical regions that make up the given virtual address region.
         /// If any part of the virtual region is unmapped, null is returned.

Ryujinx.Memory/MemoryBlock.cs

@@ -440,4 +440,4 @@ namespace Ryujinx.Memory
 
         private static void ThrowInvalidMemoryRegionException() => throw new InvalidMemoryRegionException();
     }
-}
+}

Ryujinx.Memory/MemoryMapFlags.cs

@@ -0,0 +1,23 @@
+using System;
+
+namespace Ryujinx.Memory
+{
+    /// <summary>
+    /// Flags that indicate how the host memory should be mapped.
+    /// </summary>
+    [Flags]
+    public enum MemoryMapFlags
+    {
+        /// <summary>
+        /// No mapping flags.
+        /// </summary>
+        None = 0,
+
+        /// <summary>
+        /// Indicates that the implementation is free to ignore the specified backing memory offset
+        /// and allocate its own private storage for the mapping.
+        /// This allows some mappings that would otherwise fail due to host platform restrictions to succeed.
+        /// </summary>
+        Private = 1 << 0
+    }
+}

Ryujinx.Memory/Range/HostMemoryRange.cs

@@ -0,0 +1,71 @@
+using System;
+
+namespace Ryujinx.Memory.Range
+{
+    /// <summary>
+    /// Range of memory composed of an address and size.
+    /// </summary>
+    public struct HostMemoryRange : IEquatable<HostMemoryRange>
+    {
+        /// <summary>
+        /// An empty memory range, with a null address and zero size.
+        /// </summary>
+        public static HostMemoryRange Empty => new HostMemoryRange(0, 0);
+
+        /// <summary>
+        /// Start address of the range.
+        /// </summary>
+        public nuint Address { get; }
+
+        /// <summary>
+        /// Size of the range in bytes.
+        /// </summary>
+        public ulong Size { get; }
+
+        /// <summary>
+        /// Address where the range ends (exclusive).
+        /// </summary>
+        public nuint EndAddress => Address + (nuint)Size;
+
+        /// <summary>
+        /// Creates a new memory range with the specified address and size.
+        /// </summary>
+        /// <param name="address">Start address</param>
+        /// <param name="size">Size in bytes</param>
+        public HostMemoryRange(nuint address, ulong size)
+        {
+            Address = address;
+            Size = size;
+        }
+
+        /// <summary>
+        /// Checks if the range overlaps with another.
+        /// </summary>
+        /// <param name="other">The other range to check for overlap</param>
+        /// <returns>True if the ranges overlap, false otherwise</returns>
+        public bool OverlapsWith(HostMemoryRange other)
+        {
+            nuint thisAddress = Address;
+            nuint thisEndAddress = EndAddress;
+            nuint otherAddress = other.Address;
+            nuint otherEndAddress = other.EndAddress;
+
+            return thisAddress < otherEndAddress && otherAddress < thisEndAddress;
+        }
+
+        public override bool Equals(object obj)
+        {
+            return obj is HostMemoryRange other && Equals(other);
+        }
+
+        public bool Equals(HostMemoryRange other)
+        {
+            return Address == other.Address && Size == other.Size;
+        }
+
+        public override int GetHashCode()
+        {
+            return HashCode.Combine(Address, Size);
+        }
+    }
+}

Ryujinx.Memory/Tracking/MemoryTracking.cs

@@ -139,8 +139,6 @@ namespace Ryujinx.Memory.Tracking
         /// <returns>The memory tracking handle</returns>
         public MultiRegionHandle BeginGranularTracking(ulong address, ulong size, IEnumerable<IRegionHandle> handles, ulong granularity)
         {
-            (address, size) = PageAlign(address, size);
-
             return new MultiRegionHandle(this, address, size, handles, granularity);
         }
 
@@ -166,11 +164,11 @@ namespace Ryujinx.Memory.Tracking
         /// <returns>The memory tracking handle</returns>
         public RegionHandle BeginTracking(ulong address, ulong size)
         {
-            (address, size) = PageAlign(address, size);
+            var (paAddress, paSize) = PageAlign(address, size);
 
             lock (TrackingLock)
             {
-                RegionHandle handle = new RegionHandle(this, address, size, _memoryManager.IsRangeMapped(address, size));
+                RegionHandle handle = new RegionHandle(this, paAddress, paSize, address, size, _memoryManager.IsRangeMapped(address, size));
 
                 return handle;
             }
@@ -186,11 +184,11 @@ namespace Ryujinx.Memory.Tracking
         /// <returns>The memory tracking handle</returns>
         internal RegionHandle BeginTrackingBitmap(ulong address, ulong size, ConcurrentBitmap bitmap, int bit)
         {
-            (address, size) = PageAlign(address, size);
+            var (paAddress, paSize) = PageAlign(address, size);
 
             lock (TrackingLock)
             {
-                RegionHandle handle = new RegionHandle(this, address, size, bitmap, bit, _memoryManager.IsRangeMapped(address, size));
+                RegionHandle handle = new RegionHandle(this, paAddress, paSize, address, size, bitmap, bit, _memoryManager.IsRangeMapped(address, size));
 
                 return handle;
             }

Ryujinx.Memory/Tracking/MultiRegionHandle.cs

@@ -32,7 +32,7 @@ namespace Ryujinx.Memory.Tracking
 
         internal MultiRegionHandle(MemoryTracking tracking, ulong address, ulong size, IEnumerable<IRegionHandle> handles, ulong granularity)
         {
-            _handles = new RegionHandle[size / granularity];
+            _handles = new RegionHandle[(size + granularity - 1) / granularity];
             Granularity = granularity;
 
             _dirtyBitmap = new ConcurrentBitmap(_handles.Length, true);
@@ -50,7 +50,7 @@ namespace Ryujinx.Memory.Tracking
 
                 foreach (RegionHandle handle in handles)
                 {
-                    int startIndex = (int)((handle.Address - address) / granularity);
+                    int startIndex = (int)((handle.RealAddress - address) / granularity);
 
                     // Fill any gap left before this handle.
                     while (i < startIndex)
@@ -72,7 +72,7 @@ namespace Ryujinx.Memory.Tracking
                         }
                         else
                         {
-                            int endIndex = (int)((handle.EndAddress - address) / granularity);
+                            int endIndex = (int)((handle.RealEndAddress - address) / granularity);
 
                             while (i < endIndex)
                             {
@@ -171,12 +171,13 @@ namespace Ryujinx.Memory.Tracking
                         modifiedAction(rgStart, rgSize);
                         rgSize = 0;
                     }
-                    rgStart = handle.Address;
+
+                    rgStart = handle.RealAddress;
                 }
 
                 if (handle.Dirty)
                 {
-                    rgSize += handle.Size;
+                    rgSize += handle.RealSize;
                     handle.Reprotect();
                 }
 
@@ -191,7 +192,7 @@ namespace Ryujinx.Memory.Tracking
             int startHandle = (int)((address - Address) / Granularity);
             int lastHandle = (int)((address + (size - 1) - Address) / Granularity);
 
-            ulong rgStart = _handles[startHandle].Address;
+            ulong rgStart = Address + (ulong)startHandle * Granularity;
 
             if (startHandle == lastHandle)
             {
@@ -200,7 +201,7 @@ namespace Ryujinx.Memory.Tracking
                 if (handle.Dirty)
                 {
                     handle.Reprotect();
-                    modifiedAction(rgStart, handle.Size);
+                    modifiedAction(rgStart, handle.RealSize);
                 }
 
                 return;
@@ -273,10 +274,10 @@ namespace Ryujinx.Memory.Tracking
                         modifiedAction(rgStart, rgSize);
                         rgSize = 0;
                     }
-                    rgStart = handle.Address;
+                    rgStart = handle.RealAddress;
                 }
 
-                rgSize += handle.Size;
+                rgSize += handle.RealSize;
                 handle.Reprotect(false, (checkMasks[index] & bitValue) == 0);
 
                 checkMasks[index] &= ~bitValue;
@@ -320,7 +321,7 @@ namespace Ryujinx.Memory.Tracking
                     {
                         handle.Reprotect();
 
-                        modifiedAction(rgStart, handle.Size);
+                        modifiedAction(rgStart, handle.RealSize);
                     }
                 }
 

Ryujinx.Memory/Tracking/RegionHandle.cs

@@ -42,6 +42,10 @@ namespace Ryujinx.Memory.Tracking
         public ulong Size { get; }
         public ulong EndAddress { get; }
 
+        public ulong RealAddress { get; }
+        public ulong RealSize { get; }
+        public ulong RealEndAddress { get; }
+
         internal IMultiRegionHandle Parent { get; set; }
 
         private event Action _onDirty;
@@ -89,10 +93,12 @@ namespace Ryujinx.Memory.Tracking
         /// <param name="tracking">Tracking object for the target memory block</param>
         /// <param name="address">Virtual address of the region to track</param>
         /// <param name="size">Size of the region to track</param>
+        /// <param name="realAddress">The real, unaligned address of the handle</param>
+        /// <param name="realSize">The real, unaligned size of the handle</param>
         /// <param name="bitmap">The bitmap the dirty flag for this handle is stored in</param>
         /// <param name="bit">The bit index representing the dirty flag for this handle</param>
         /// <param name="mapped">True if the region handle starts mapped</param>
-        internal RegionHandle(MemoryTracking tracking, ulong address, ulong size, ConcurrentBitmap bitmap, int bit, bool mapped = true)
+        internal RegionHandle(MemoryTracking tracking, ulong address, ulong size, ulong realAddress, ulong realSize, ConcurrentBitmap bitmap, int bit, bool mapped = true)
         {
             Bitmap = bitmap;
             DirtyBit = bit;
@@ -104,6 +110,10 @@ namespace Ryujinx.Memory.Tracking
             Size = size;
             EndAddress = address + size;
 
+            RealAddress = realAddress;
+            RealSize = realSize;
+            RealEndAddress = realAddress + realSize;
+
             _tracking = tracking;
             _regions = tracking.GetVirtualRegionsForHandle(address, size);
             foreach (var region in _regions)
@@ -119,16 +129,23 @@ namespace Ryujinx.Memory.Tracking
         /// <param name="tracking">Tracking object for the target memory block</param>
         /// <param name="address">Virtual address of the region to track</param>
         /// <param name="size">Size of the region to track</param>
+        /// <param name="realAddress">The real, unaligned address of the handle</param>
+        /// <param name="realSize">The real, unaligned size of the handle</param>
         /// <param name="mapped">True if the region handle starts mapped</param>
-        internal RegionHandle(MemoryTracking tracking, ulong address, ulong size, bool mapped = true)
+        internal RegionHandle(MemoryTracking tracking, ulong address, ulong size, ulong realAddress, ulong realSize, bool mapped = true)
         {
             Bitmap = new ConcurrentBitmap(1, mapped);
 
             Unmapped = !mapped;
+
             Address = address;
             Size = size;
             EndAddress = address + size;
 
+            RealAddress = realAddress;
+            RealSize = realSize;
+            RealEndAddress = realAddress + realSize;
+
             _tracking = tracking;
             _regions = tracking.GetVirtualRegionsForHandle(address, size);
             foreach (var region in _regions)
@@ -199,6 +216,10 @@ namespace Ryujinx.Memory.Tracking
 
             if (_preAction != null)
             {
+                // Limit the range to within this handle.
+                ulong maxAddress = Math.Max(address, RealAddress);
+                ulong minEndAddress = Math.Min(address + size, RealAddress + RealSize);
+
                 // Copy the handles list in case it changes when we're out of the lock.
                 if (handleIterable is List<RegionHandle>)
                 {
@@ -212,7 +233,7 @@ namespace Ryujinx.Memory.Tracking
                 {
                     lock (_preActionLock)
                     {
-                        _preAction?.Invoke(address, size);
+                        _preAction?.Invoke(maxAddress, minEndAddress - maxAddress);
 
                         // The action is removed after it returns, to ensure that the null check above succeeds when
                         // it's still in progress rather than continuing and possibly missing a required data flush.

Ryujinx.Tests/Cpu/CpuTest.cs

@@ -53,7 +53,7 @@ namespace Ryujinx.Tests.Cpu
             _ram = new MemoryBlock(Size * 2);
             _memory = new MemoryManager(_ram, 1ul << 16);
             _memory.IncrementReferenceCount();
-            _memory.Map(CodeBaseAddress, 0, Size * 2);
+            _memory.Map(CodeBaseAddress, 0, Size * 2, MemoryMapFlags.Private);
 
             _context = CpuContext.CreateExecutionContext();
             Translator.IsReadyForTranslation.Set();

Ryujinx.Tests/Cpu/CpuTest32.cs

@@ -48,7 +48,7 @@ namespace Ryujinx.Tests.Cpu
             _ram = new MemoryBlock(Size * 2);
             _memory = new MemoryManager(_ram, 1ul << 16);
             _memory.IncrementReferenceCount();
-            _memory.Map(CodeBaseAddress, 0, Size * 2);
+            _memory.Map(CodeBaseAddress, 0, Size * 2, MemoryMapFlags.Private);
 
             _context = CpuContext.CreateExecutionContext();
             _context.IsAarch32 = true;