Cover Linux aligned mapping retention

src/SharpEmu.Core/Memory/PhysicalVirtualMemory.cs

@@ -349,10 +349,8 @@ public sealed unsafe class PhysicalVirtualMemory : IVirtualMemory, IGuestMemoryA
         var requestedCursor = AlignUp(desiredAddress, effectiveAlignment);
         var cursor = GetAllocationSearchCursor(desiredAddress, requestedCursor, effectiveAlignment, executable);
 
-        // POSIX treats the requested address as a hint, and Rosetta may
+        // macOS needs alignment over-allocation; Linux uses exact-address search.
-        // relocate whole guest windows. Over-allocate once so the returned
+        if (OperatingSystem.IsMacOS())
-        // host range always contains an aligned guest-visible start.
-        if (!OperatingSystem.IsWindows())
         {
             var reserveSize = effectiveAlignment > PageSize
                 ? alignedSize + effectiveAlignment

src/SharpEmu.GUI/GuiSettings.cs

@@ -23,6 +23,9 @@ public sealed class GuiSettings
 
     public bool StrictDynlibResolution { get; set; }
 
+    /// <summary>GPU implementation selected for newly launched games.</summary>
+    public string RenderingBackend { get; set; } = "Legacy";
+
     /// <summary>
     /// Mirror emulator output to user/logs/&lt;titleId&gt;-&lt;timestamp&gt;.log, if <see cref="LogFilePath"/> is null.
     /// </summary>

src/SharpEmu.GUI/Languages/en.json

@@ -43,6 +43,12 @@
   "Options.CpuEngine.Desc": "Execution engine used to run game code.",
   "Options.CpuEngine.Native": "Native",
 
+  "Options.RenderingBackend.Label": "Rendering backend",
+  "Options.RenderingBackend.Desc": "Graphics implementation used for newly launched games. Native Vulkan requires a separate library.",
+  "Options.RenderingBackend.Native": "Native Vulkan (Experimental)",
+  "Options.RenderingBackend.Legacy": "Silk.NET Vulkan (Default)",
+  "Launch.NativeBackendMissing": "WARNING: Native Vulkan is selected, but {0} was not found next to SharpEmu. Download it from https://github.com/sharpemu/sharpemu.vulkan or select Silk.NET Vulkan in Options.",
+
   "Options.Strict.Label": "Strict dynlib resolution",
   "Options.Strict.Desc": "Fail the launch when an imported symbol cannot be resolved.",
 

src/SharpEmu.GUI/MainWindow.axaml

@@ -203,6 +203,19 @@ SPDX-License-Identifier: GPL-2.0-or-later
                         </ComboBox>
                       </Grid>
 
+                      <Grid ColumnDefinitions="*,Auto">
+                        <StackPanel VerticalAlignment="Center" Spacing="2" Margin="0,0,16,0">
+                          <TextBlock x:Name="RenderingBackendLabel" Text="Rendering backend" FontSize="13" />
+                          <TextBlock x:Name="RenderingBackendDesc" Text="Graphics implementation used for newly launched games."
+                                     FontSize="11" Foreground="{StaticResource MutedBrush}" TextWrapping="Wrap" />
+                        </StackPanel>
+                        <ComboBox Grid.Column="1" x:Name="RenderingBackendBox" Width="200" SelectedIndex="0"
+                                  VerticalAlignment="Center" CornerRadius="8">
+                          <ComboBoxItem x:Name="RenderingBackendLegacyItem" Content="Silk.NET Vulkan (Default)" />
+                          <ComboBoxItem x:Name="RenderingBackendNativeItem" Content="Native Vulkan (Experimental)" />
+                        </ComboBox>
+                      </Grid>
+
                       <Grid ColumnDefinitions="*,Auto">
                         <StackPanel VerticalAlignment="Center" Spacing="2" Margin="0,0,16,0">
                           <TextBlock x:Name="StrictLabel" Text="Strict dynlib resolution" FontSize="13" />

src/SharpEmu.GUI/MainWindow.axaml.cs

@@ -116,6 +116,8 @@ public partial class MainWindow : Window
         // The settings page edits _settings live, so a launch started while
         // it is open already uses the new values.
         LogLevelBox.SelectionChanged += (_, _) => _settings.LogLevel = SelectedLogLevel();
+        RenderingBackendBox.SelectionChanged += (_, _) =>
+            _settings.RenderingBackend = SelectedRenderingBackend();
         TraceImportsBox.ValueChanged += (_, _) => _settings.ImportTraceLimit = (int)(TraceImportsBox.Value ?? 0);
         StrictToggle.IsCheckedChanged += (_, _) => _settings.StrictDynlibResolution = StrictToggle.IsChecked == true;
         LogToFileToggle.IsCheckedChanged += (_, _) => _settings.LogToFile = LogToFileToggle.IsChecked == true;
@@ -439,6 +441,11 @@ public partial class MainWindow : Window
         CpuEngineDesc.Text = loc.Get("Options.CpuEngine.Desc");
         CpuEngineNativeItem.Content = loc.Get("Options.CpuEngine.Native");
 
+        RenderingBackendLabel.Text = loc.Get("Options.RenderingBackend.Label");
+        RenderingBackendDesc.Text = loc.Get("Options.RenderingBackend.Desc");
+        RenderingBackendNativeItem.Content = loc.Get("Options.RenderingBackend.Native");
+        RenderingBackendLegacyItem.Content = loc.Get("Options.RenderingBackend.Legacy");
+
         StrictLabel.Text = loc.Get("Options.Strict.Label");
         StrictDesc.Text = loc.Get("Options.Strict.Desc");
 
@@ -596,6 +603,10 @@ public partial class MainWindow : Window
 
     private void ApplySettingsToControls()
     {
+        RenderingBackendBox.SelectedIndex = string.Equals(
+            _settings.RenderingBackend,
+            "Native",
+            StringComparison.OrdinalIgnoreCase) ? 1 : 0;
         LogLevelBox.SelectedIndex = _settings.LogLevel.ToLowerInvariant() switch
         {
             "trace" => 0,
@@ -654,6 +665,9 @@ public partial class MainWindow : Window
         };
     }
 
+    private string SelectedRenderingBackend() =>
+        RenderingBackendBox.SelectedIndex == 1 ? "Native" : "Legacy";
+
     private void UpdateLogFilePathText()
     {
         LogFilePathText.Text = string.IsNullOrWhiteSpace(_settings.LogFilePath)
@@ -1473,6 +1487,31 @@ public partial class MainWindow : Window
             _appliedEnvironmentVariables.Add(name);
         }
 
+        // The GUI owns this setting when it launches the emulator. Set both
+        // choices explicitly so a SHARPEMU_GPU_BACKEND value inherited by the
+        // launcher cannot silently override the Options menu.
+        Environment.SetEnvironmentVariable(
+            "SHARPEMU_GPU_BACKEND",
+            string.Equals(_settings.RenderingBackend, "Legacy", StringComparison.OrdinalIgnoreCase)
+                ? "legacy"
+                : "native");
+
+        if (string.Equals(_settings.RenderingBackend, "Native", StringComparison.OrdinalIgnoreCase))
+        {
+            var nativeLibraryName = OperatingSystem.IsWindows()
+                ? "sharpemu_gpu_vulkan.dll"
+                : OperatingSystem.IsMacOS()
+                    ? "libsharpemu_gpu_vulkan.dylib"
+                    : "libsharpemu_gpu_vulkan.so";
+            var emulatorDirectory = Path.GetDirectoryName(_emulatorExePath) ?? AppContext.BaseDirectory;
+            if (!File.Exists(Path.Combine(emulatorDirectory, nativeLibraryName)))
+            {
+                AppendConsoleLine(
+                    Localization.Instance.Format("Launch.NativeBackendMissing", nativeLibraryName),
+                    WarningLineBrush);
+            }
+        }
+
         var emulator = new EmulatorProcess();
         emulator.OutputReceived += (line, isError) => _pendingLines.Enqueue((line, isError));
         emulator.Exited += code => Dispatcher.UIThread.Post(() => OnEmulatorExited(code));

src/SharpEmu.Libs/Gpu/GuestGpu.cs

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 using SharpEmu.Libs.Gpu.Vulkan;
+using SharpEmu.Libs.Gpu.NativeVulkan;
 
 namespace SharpEmu.Libs.Gpu;
 
@@ -12,7 +13,25 @@ namespace SharpEmu.Libs.Gpu;
 /// </summary>
 internal static class GuestGpu
 {
-    private static readonly Lazy<IGuestGpuBackend> Instance = new(static () => new VulkanGuestGpuBackend());
+    private static readonly Lazy<IGuestGpuBackend> Instance = new(CreateBackend);
 
     public static IGuestGpuBackend Current => Instance.Value;
+
+    private static IGuestGpuBackend CreateBackend()
+    {
+        if (!string.Equals(
+                Environment.GetEnvironmentVariable("SHARPEMU_GPU_BACKEND"),
+                "native",
+                StringComparison.OrdinalIgnoreCase))
+        {
+            return new VulkanGuestGpuBackend();
+        }
+
+        if (!NativeVulkanApi.IsAvailable(out var error))
+        {
+            Console.Error.WriteLine($"[LOADER][WARN] {error}");
+        }
+
+        return new NativeVulkanGuestGpuBackend();
+    }
 }

src/SharpEmu.Libs/Gpu/NativeVulkan/NativeGpuInputSource.cs

@@ -0,0 +1,71 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Runtime.InteropServices;
+using SharpEmu.HLE.Host;
+using SharpEmu.HLE.Host.Posix;
+
+namespace SharpEmu.Libs.Gpu.NativeVulkan;
+
+internal sealed unsafe class NativeGpuInputSource : IPosixWindowInputSource
+{
+    internal static NativeGpuInputSource Instance { get; } = new();
+    private readonly object _gate = new();
+    private readonly uint[] _keys = new uint[8];
+    private bool _focused;
+    private bool _gamepadConnected;
+    private HostGamepadState _gamepad;
+    private string? _gamepadName;
+
+    private NativeGpuInputSource() { }
+
+    internal void Attach() => PosixHostInput.SetSource(this);
+
+    internal void Update(NativeVulkanApi.Input* state)
+    {
+        lock (_gate)
+        {
+            _focused = state->KeyboardFocused != 0;
+            for (var index = 0; index < _keys.Length; ++index) _keys[index] = state->VirtualKeys[index];
+            _gamepadConnected = state->GamepadConnected != 0;
+            _gamepad = new HostGamepadState(
+                _gamepadConnected,
+                (HostGamepadButtons)state->GamepadButtons,
+                state->LeftX,
+                state->LeftY,
+                state->RightX,
+                state->RightY,
+                state->LeftTrigger,
+                state->RightTrigger);
+            _gamepadName = _gamepadConnected
+                ? Marshal.PtrToStringUTF8((nint)state->GamepadNameUtf8)
+                : null;
+        }
+    }
+
+    public bool HasKeyboardFocus
+    {
+        get { lock (_gate) return _focused; }
+    }
+
+    public bool IsKeyDown(int virtualKey)
+    {
+        if ((uint)virtualKey >= 256) return false;
+        lock (_gate) return (_keys[virtualKey / 32] & (1u << (virtualKey % 32))) != 0;
+    }
+
+    public int GetGamepadStates(Span<HostGamepadState> destination)
+    {
+        lock (_gate)
+        {
+            if (!_gamepadConnected || destination.IsEmpty) return 0;
+            destination[0] = _gamepad;
+            return 1;
+        }
+    }
+
+    public string? DescribeConnectedGamepad()
+    {
+        lock (_gate) return _gamepadConnected ? _gamepadName ?? "SDL gamepad" : null;
+    }
+}

src/SharpEmu.Libs/Gpu/NativeVulkan/NativeGpuPacket.cs

@@ -0,0 +1,182 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Runtime.InteropServices;
+using SharpEmu.Libs.Gpu.Vulkan;
+using SharpEmu.ShaderCompiler.Vulkan;
+
+namespace SharpEmu.Libs.Gpu.NativeVulkan;
+
+internal static unsafe class NativeGpuPacket
+{
+    internal static NativeGpuResult SubmitDraw(
+        nint backend,
+        VulkanCompiledGuestShader pixelShader,
+        IReadOnlyList<GuestDrawTexture> textures,
+        IReadOnlyList<GuestMemoryBuffer> memoryBuffers,
+        uint width,
+        uint height,
+        uint attributeCount,
+        VulkanCompiledGuestShader? vertexShader,
+        uint vertexCount,
+        uint instanceCount,
+        uint primitiveType,
+        GuestIndexBuffer? indexBuffer,
+        IReadOnlyList<GuestVertexBuffer>? vertexBuffers,
+        GuestRenderState? renderState,
+        IReadOnlyList<GuestRenderTarget>? targets,
+        bool publishTargets)
+    {
+        using var storage = new Storage();
+        var nativeTextures = storage.Allocate<NativeVulkanApi.Texture>(textures.Count);
+        for (var index = 0; index < textures.Count; ++index)
+            nativeTextures[index] = Texture(textures[index], storage);
+        var nativeMemory = storage.Allocate<NativeVulkanApi.MemoryBuffer>(memoryBuffers.Count);
+        for (var index = 0; index < memoryBuffers.Count; ++index)
+            nativeMemory[index] = new() { Address = memoryBuffers[index].BaseAddress, Data = storage.Pin(memoryBuffers[index].Data) };
+        var vertices = vertexBuffers ?? [];
+        var nativeVertices = storage.Allocate<NativeVulkanApi.VertexBuffer>(vertices.Count);
+        for (var index = 0; index < vertices.Count; ++index)
+        {
+            var source = vertices[index];
+            nativeVertices[index] = new()
+            {
+                StructSize = (uint)sizeof(NativeVulkanApi.VertexBuffer), Location = source.Location,
+                ComponentCount = source.ComponentCount, DataFormat = source.DataFormat,
+                NumberFormat = source.NumberFormat, Address = source.BaseAddress, Stride = source.Stride,
+                OffsetBytes = source.OffsetBytes, Data = storage.Pin(source.Data),
+            };
+        }
+        var targetList = targets ?? [];
+        var nativeTargets = storage.Allocate<NativeVulkanApi.RenderTarget>(targetList.Count);
+        for (var index = 0; index < targetList.Count; ++index)
+        {
+            var source = targetList[index];
+            nativeTargets[index] = new()
+            {
+                StructSize = (uint)sizeof(NativeVulkanApi.RenderTarget), Address = source.Address,
+                Width = source.Width, Height = source.Height, Format = source.Format,
+                NumberType = source.NumberType, MipLevels = source.MipLevels,
+            };
+        }
+        var state = renderState ?? GuestRenderState.Default;
+        var blends = storage.Allocate<NativeVulkanApi.Blend>(state.Blends.Count);
+        for (var index = 0; index < state.Blends.Count; ++index)
+        {
+            var source = state.Blends[index];
+            blends[index] = new()
+            {
+                Enable = source.Enable ? 1u : 0u, ColorSrc = source.ColorSrcFactor,
+                ColorDst = source.ColorDstFactor, ColorFunc = source.ColorFunc,
+                AlphaSrc = source.AlphaSrcFactor, AlphaDst = source.AlphaDstFactor,
+                AlphaFunc = source.AlphaFunc, SeparateAlpha = source.SeparateAlphaBlend ? 1u : 0u,
+                WriteMask = source.WriteMask,
+            };
+        }
+        NativeVulkanApi.IndexBuffer nativeIndex = default;
+        NativeVulkanApi.IndexBuffer* nativeIndexPointer = null;
+        if (indexBuffer is not null)
+        {
+            nativeIndex = new() { Data = storage.Pin(indexBuffer.Data), Is32Bit = indexBuffer.Is32Bit ? 1u : 0u };
+            nativeIndexPointer = &nativeIndex;
+        }
+        NativeVulkanApi.Rect nativeScissor = default; NativeVulkanApi.Rect* scissorPointer = null;
+        if (state.Scissor is { } scissor)
+        {
+            nativeScissor = new() { X = scissor.X, Y = scissor.Y, Width = scissor.Width, Height = scissor.Height };
+            scissorPointer = &nativeScissor;
+        }
+        NativeVulkanApi.Viewport nativeViewport = default; NativeVulkanApi.Viewport* viewportPointer = null;
+        if (state.Viewport is { } viewport)
+        {
+            nativeViewport = new()
+            {
+                X = viewport.X, Y = viewport.Y, Width = viewport.Width, Height = viewport.Height,
+                MinDepth = viewport.MinDepth, MaxDepth = viewport.MaxDepth,
+            };
+            viewportPointer = &nativeViewport;
+        }
+        var draw = new NativeVulkanApi.Draw
+        {
+            StructSize = (uint)sizeof(NativeVulkanApi.Draw),
+            Width = width,
+            Height = height,
+            VertexSpirv = storage.Pin(vertexShader?.Spirv ?? SpirvFixedShaders.CreateFullscreenVertex(attributeCount)),
+            PixelSpirv = storage.Pin(pixelShader.Spirv), Textures = nativeTextures,
+            TextureCount = (uint)textures.Count, MemoryBuffers = nativeMemory,
+            MemoryBufferCount = (uint)memoryBuffers.Count, VertexBuffers = nativeVertices,
+            VertexBufferCount = (uint)vertices.Count, Targets = nativeTargets,
+            TargetCount = (uint)targetList.Count, Blends = blends, BlendCount = (uint)state.Blends.Count,
+            IndexBuffer = nativeIndexPointer, Scissor = scissorPointer, ViewportState = viewportPointer,
+            AttributeCount = attributeCount, VertexCount = vertexCount, InstanceCount = instanceCount,
+            PrimitiveType = primitiveType, PublishTargets = publishTargets ? 1u : 0u,
+        };
+        return NativeVulkanApi.SubmitDraw(backend, &draw);
+    }
+
+    internal static NativeGpuResult SubmitCompute(
+        nint backend,
+        ulong shaderAddress,
+        VulkanCompiledGuestShader shader,
+        IReadOnlyList<GuestDrawTexture> textures,
+        IReadOnlyList<GuestMemoryBuffer> buffers,
+        uint x, uint y, uint z)
+    {
+        using var storage = new Storage();
+        var nativeTextures = storage.Allocate<NativeVulkanApi.Texture>(textures.Count);
+        for (var index = 0; index < textures.Count; ++index) nativeTextures[index] = Texture(textures[index], storage);
+        var nativeBuffers = storage.Allocate<NativeVulkanApi.MemoryBuffer>(buffers.Count);
+        for (var index = 0; index < buffers.Count; ++index)
+            nativeBuffers[index] = new() { Address = buffers[index].BaseAddress, Data = storage.Pin(buffers[index].Data) };
+        var compute = new NativeVulkanApi.Compute
+        {
+            StructSize = (uint)sizeof(NativeVulkanApi.Compute), ShaderAddress = shaderAddress,
+            Spirv = storage.Pin(shader.Spirv), Textures = nativeTextures, TextureCount = (uint)textures.Count,
+            MemoryBuffers = nativeBuffers, MemoryBufferCount = (uint)buffers.Count,
+            GroupsX = x, GroupsY = y, GroupsZ = z,
+        };
+        return NativeVulkanApi.SubmitCompute(backend, &compute);
+    }
+
+    private static NativeVulkanApi.Texture Texture(GuestDrawTexture source, Storage storage)
+    {
+        var result = new NativeVulkanApi.Texture
+        {
+            StructSize = (uint)sizeof(NativeVulkanApi.Texture), Address = source.Address,
+            Width = source.Width, Height = source.Height, Format = source.Format,
+            NumberType = source.NumberType, RgbaPixels = storage.Pin(source.RgbaPixels),
+            IsFallback = source.IsFallback ? 1u : 0u, IsStorage = source.IsStorage ? 1u : 0u,
+            MipLevels = source.MipLevels, MipLevel = source.MipLevel, Pitch = source.Pitch,
+            TileMode = source.TileMode, DstSelect = source.DstSelect,
+        };
+        result.SamplerState.Words[0] = source.Sampler.Word0;
+        result.SamplerState.Words[1] = source.Sampler.Word1;
+        result.SamplerState.Words[2] = source.Sampler.Word2;
+        result.SamplerState.Words[3] = source.Sampler.Word3;
+        return result;
+    }
+
+    private sealed class Storage : IDisposable
+    {
+        private readonly List<GCHandle> _pins = [];
+        private readonly List<nint> _allocations = [];
+        internal NativeVulkanApi.Bytes Pin(byte[] data)
+        {
+            if (data.Length == 0) return default;
+            var pin = GCHandle.Alloc(data, GCHandleType.Pinned); _pins.Add(pin);
+            return new() { Data = (void*)pin.AddrOfPinnedObject(), Size = (nuint)data.Length };
+        }
+        internal T* Allocate<T>(int count) where T : unmanaged
+        {
+            if (count == 0) return null;
+            var pointer = NativeMemory.AllocZeroed((nuint)count, (nuint)sizeof(T));
+            if (pointer is null) throw new OutOfMemoryException();
+            _allocations.Add((nint)pointer); return (T*)pointer;
+        }
+        public void Dispose()
+        {
+            foreach (var pin in _pins) pin.Free();
+            foreach (var allocation in _allocations) NativeMemory.Free((void*)allocation);
+        }
+    }
+}

src/SharpEmu.Libs/Gpu/NativeVulkan/NativeVulkanApi.cs

@@ -0,0 +1,197 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace SharpEmu.Libs.Gpu.NativeVulkan;
+
+internal enum NativeGpuResult
+{
+    Success = 0,
+    NotFound = 1,
+    NotReady = 2,
+    InvalidArgument = -1,
+    IncompatibleAbi = -2,
+    PlatformError = -3,
+    VulkanError = -4,
+    OutOfMemory = -5,
+    InternalError = -6,
+}
+
+internal static unsafe partial class NativeVulkanApi
+{
+    internal const uint AbiVersion = 1;
+    private const string Library = "sharpemu_gpu_vulkan";
+
+    internal static string LibraryFileName =>
+        OperatingSystem.IsWindows() ? "sharpemu_gpu_vulkan.dll" :
+        OperatingSystem.IsMacOS() ? "libsharpemu_gpu_vulkan.dylib" :
+        "libsharpemu_gpu_vulkan.so";
+
+    internal static bool IsAvailable(out string error)
+    {
+        if (NativeLibrary.TryLoad(
+                Library,
+                typeof(NativeVulkanApi).Assembly,
+                DllImportSearchPath.SafeDirectories | DllImportSearchPath.AssemblyDirectory,
+                out var handle))
+        {
+            NativeLibrary.Free(handle);
+            error = string.Empty;
+            return true;
+        }
+
+        error =
+            $"The optional native Vulkan backend was selected, but {LibraryFileName} could not be loaded. " +
+            "Place the library from https://github.com/sharpemu/sharpemu.vulkan next to the SharpEmu executable " +
+            "and ensure its SDL3 and Vulkan runtime dependencies are installed.";
+        return false;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct CreateInfo
+    {
+        internal uint StructSize;
+        internal uint AbiVersion;
+        internal uint Width;
+        internal uint Height;
+        internal uint EnableValidation;
+        internal byte* TitleUtf8;
+        internal delegate* unmanaged[Cdecl]<int, byte*, void*, void> Log;
+        internal void* LogUser;
+    }
+
+    [StructLayout(LayoutKind.Sequential)] internal struct Bytes { internal void* Data; internal nuint Size; }
+    [StructLayout(LayoutKind.Sequential)] internal struct Sampler { internal fixed uint Words[4]; }
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct Texture
+    {
+        internal uint StructSize; internal ulong Address; internal uint Width, Height, Format, NumberType;
+        internal Bytes RgbaPixels; internal uint IsFallback, IsStorage, MipLevels, MipLevel;
+        internal uint Pitch, TileMode, DstSelect; internal Sampler SamplerState;
+    }
+    [StructLayout(LayoutKind.Sequential)] internal struct MemoryBuffer { internal ulong Address; internal Bytes Data; }
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct VertexBuffer
+    {
+        internal uint StructSize, Location, ComponentCount, DataFormat, NumberFormat;
+        internal ulong Address; internal uint Stride, OffsetBytes; internal Bytes Data;
+    }
+    [StructLayout(LayoutKind.Sequential)] internal struct IndexBuffer { internal Bytes Data; internal uint Is32Bit; }
+    [StructLayout(LayoutKind.Sequential)] internal struct Rect { internal int X, Y; internal uint Width, Height; }
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct Viewport { internal float X, Y, Width, Height, MinDepth, MaxDepth; }
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct Blend
+    {
+        internal uint Enable, ColorSrc, ColorDst, ColorFunc, AlphaSrc, AlphaDst, AlphaFunc;
+        internal uint SeparateAlpha, WriteMask;
+    }
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct RenderTarget
+    {
+        internal uint StructSize; internal ulong Address;
+        internal uint Width, Height, Format, NumberType, MipLevels;
+    }
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct Draw
+    {
+        internal uint StructSize, Width, Height; internal Bytes VertexSpirv, PixelSpirv;
+        internal Texture* Textures; internal uint TextureCount;
+        internal MemoryBuffer* MemoryBuffers; internal uint MemoryBufferCount;
+        internal VertexBuffer* VertexBuffers; internal uint VertexBufferCount;
+        internal RenderTarget* Targets; internal uint TargetCount;
+        internal Blend* Blends; internal uint BlendCount;
+        internal IndexBuffer* IndexBuffer; internal Rect* Scissor; internal Viewport* ViewportState;
+        internal uint AttributeCount, VertexCount, InstanceCount, PrimitiveType, PublishTargets;
+    }
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct Compute
+    {
+        internal uint StructSize; internal ulong ShaderAddress; internal Bytes Spirv;
+        internal Texture* Textures; internal uint TextureCount;
+        internal MemoryBuffer* MemoryBuffers; internal uint MemoryBufferCount;
+        internal uint GroupsX, GroupsY, GroupsZ;
+    }
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct Input
+    {
+        internal uint StructSize, KeyboardFocused;
+        internal fixed uint VirtualKeys[8];
+        internal uint GamepadConnected, GamepadButtons;
+        internal byte LeftX, LeftY, RightX, RightY, LeftTrigger, RightTrigger;
+        internal fixed byte Reserved[2]; internal fixed byte GamepadNameUtf8[128];
+    }
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_abi_version")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial uint GetAbiVersion();
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_last_error")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    private static partial byte* LastError(nint backend);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_create")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult Create(CreateInfo* info, out nint backend);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_destroy")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial void Destroy(nint backend);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_poll")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult Poll(nint backend, out uint shouldClose);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_input_snapshot")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult InputSnapshot(nint backend, Input* input);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_present_bgra")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult PresentBgra(
+        nint backend,
+        void* pixels,
+        nuint size,
+        uint width,
+        uint height,
+        uint pitch);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_submit_draw")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult SubmitDraw(nint backend, Draw* draw);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_submit_compute")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult SubmitCompute(nint backend, Compute* compute);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_register_display_buffer")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult RegisterDisplayBuffer(nint backend, ulong address, uint format);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_present_guest_image")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult PresentGuestImage(
+        nint backend, ulong address, uint width, uint height, uint pitch);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_has_guest_image")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult HasGuestImage(nint backend, ulong address, uint format, uint numberType);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_blit_guest_image")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult BlitGuestImage(
+        nint backend, ulong sourceAddress, uint sourceWidth, uint sourceHeight, uint sourceFormat,
+        ulong destinationAddress, uint destinationWidth, uint destinationHeight, uint destinationFormat);
+
+    [LibraryImport(Library, EntryPoint = "se_gpu_render_target_output_kind")]
+    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
+    internal static partial NativeGpuResult RenderTargetOutputKind(uint format, uint numberType, out uint outputKind);
+
+    internal static string GetError(nint backend)
+    {
+        var pointer = LastError(backend);
+        return pointer is null ? "Unknown native GPU error" : Marshal.PtrToStringUTF8((nint)pointer)!;
+    }
+}

src/SharpEmu.Libs/Gpu/NativeVulkan/NativeVulkanGuestGpuBackend.cs

@@ -0,0 +1,302 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Collections.Concurrent;
+using System.Runtime.InteropServices;
+using SharpEmu.Libs.Gpu.Vulkan;
+using SharpEmu.ShaderCompiler;
+using SharpEmu.ShaderCompiler.Vulkan;
+
+namespace SharpEmu.Libs.Gpu.NativeVulkan;
+
+/// <summary>Native C++ Vulkan implementation of the guest-domain GPU seam.</summary>
+internal sealed unsafe class NativeVulkanGuestGpuBackend : IGuestGpuBackend
+{
+    private static readonly IGuestCompiledShader DepthOnlyFragmentShader =
+        new VulkanCompiledGuestShader(SpirvFixedShaders.CreateDepthOnlyFragment());
+
+    private readonly object _startGate = new();
+    private readonly BlockingCollection<Action<nint>> _commands = new(new ConcurrentQueue<Action<nint>>(), 256);
+    private readonly ManualResetEventSlim _ready = new(false);
+    private Thread? _thread;
+    private Exception? _startError;
+
+    public void EnsureStarted(uint width, uint height)
+    {
+        if (width == 0 || height == 0) return;
+        lock (_startGate)
+        {
+            if (_thread is null)
+            {
+                _thread = new Thread(() => Run(width, height))
+                {
+                    IsBackground = true,
+                    Name = "SharpEmu native Vulkan",
+                };
+                _thread.Start();
+            }
+        }
+        _ready.Wait();
+        if (_startError is not null)
+        {
+            if (_startError is DllNotFoundException)
+            {
+                _ = NativeVulkanApi.IsAvailable(out var error);
+                throw new InvalidOperationException(error, _startError);
+            }
+
+            throw new InvalidOperationException("Native Vulkan startup failed", _startError);
+        }
+    }
+
+    public bool TryCompileVertexShader(Gen5ShaderState state, Gen5ShaderEvaluation evaluation,
+        out IGuestCompiledShader? shader, out string error, int globalBufferBase = 0,
+        int totalGlobalBufferCount = -1, int imageBindingBase = 0, int scalarRegisterBufferIndex = -1,
+        int requiredVertexOutputCount = 0, ulong storageBufferOffsetAlignment = 1)
+    {
+        shader = null;
+        if (!Gen5SpirvTranslator.TryCompileVertexShader(state, evaluation, out var compiled, out error,
+                globalBufferBase, totalGlobalBufferCount, imageBindingBase, scalarRegisterBufferIndex,
+                requiredVertexOutputCount, storageBufferOffsetAlignment)) return false;
+        shader = new VulkanCompiledGuestShader(compiled.Spirv); return true;
+    }
+
+    public bool TryCompilePixelShader(Gen5ShaderState state, Gen5ShaderEvaluation evaluation,
+        IReadOnlyList<Gen5PixelOutputBinding> outputs, out IGuestCompiledShader? shader, out string error,
+        int globalBufferBase = 0, int totalGlobalBufferCount = -1, int imageBindingBase = 0,
+        int scalarRegisterBufferIndex = -1, uint pixelInputEnable = 0, uint pixelInputAddress = 0,
+        ulong storageBufferOffsetAlignment = 1)
+    {
+        shader = null;
+        if (!Gen5SpirvTranslator.TryCompilePixelShader(state, evaluation, outputs, out var compiled, out error,
+                globalBufferBase, totalGlobalBufferCount, imageBindingBase, scalarRegisterBufferIndex,
+                pixelInputEnable, pixelInputAddress, storageBufferOffsetAlignment)) return false;
+        shader = new VulkanCompiledGuestShader(compiled.Spirv); return true;
+    }
+
+    public bool TryCompileComputeShader(Gen5ShaderState state, Gen5ShaderEvaluation evaluation,
+        uint localSizeX, uint localSizeY, uint localSizeZ, out IGuestCompiledShader? shader, out string error,
+        int totalGlobalBufferCount = -1, int initialScalarBufferIndex = -1, uint waveLaneCount = 32,
+        ulong storageBufferOffsetAlignment = 1)
+    {
+        shader = null;
+        if (!Gen5SpirvTranslator.TryCompileComputeShader(state, evaluation, localSizeX, localSizeY, localSizeZ,
+                out var compiled, out error, totalGlobalBufferCount, initialScalarBufferIndex, waveLaneCount,
+                storageBufferOffsetAlignment)) return false;
+        shader = new VulkanCompiledGuestShader(compiled.Spirv); return true;
+    }
+
+    public IGuestCompiledShader GetDepthOnlyFragmentShader() => DepthOnlyFragmentShader;
+
+    public void HideSplashScreen() { }
+
+    public void Submit(byte[] bgraFrame, uint width, uint height)
+    {
+        if (bgraFrame.Length != checked((int)(width * height * 4))) return;
+        EnsureStarted(width, height);
+        Enqueue(handle =>
+        {
+            fixed (byte* pixels = bgraFrame)
+                Check(handle, NativeVulkanApi.PresentBgra(handle, pixels, (nuint)bgraFrame.Length, width, height, width * 4));
+        });
+    }
+
+    public void SubmitGuestDraw(GuestDrawKind drawKind, uint width, uint height)
+    {
+        if (drawKind != GuestDrawKind.FullscreenBarycentric || width == 0 || height == 0) return;
+        EnsureStarted(width, height);
+        var pixel = new VulkanCompiledGuestShader(SpirvFixedShaders.CreateBarycentricFragment());
+        Enqueue(handle => Check(handle, NativeGpuPacket.SubmitDraw(handle, pixel, [], [],
+            width, height, 1, null, 3, 1, 4, null, null, null, null, false)));
+    }
+
+    public void SubmitTranslatedDraw(IGuestCompiledShader pixelShader, IReadOnlyList<GuestDrawTexture> textures,
+        IReadOnlyList<GuestMemoryBuffer> globalMemoryBuffers, uint width, uint height, uint attributeCount,
+        IGuestCompiledShader? vertexShader = null, uint vertexCount = 3, uint instanceCount = 1,
+        uint primitiveType = 4, GuestIndexBuffer? indexBuffer = null,
+        IReadOnlyList<GuestVertexBuffer>? vertexBuffers = null, GuestRenderState? renderState = null)
+    {
+        EnsureStarted(width, height);
+        var ps = Spirv(pixelShader); var vs = vertexShader is null ? null : Spirv(vertexShader);
+        var textureCopy = textures.ToArray(); var memoryCopy = globalMemoryBuffers.ToArray();
+        var vertexCopy = vertexBuffers?.ToArray();
+        Enqueue(handle => Check(handle, NativeGpuPacket.SubmitDraw(handle, ps, textureCopy, memoryCopy,
+            width, height, attributeCount, vs, vertexCount, instanceCount, primitiveType, indexBuffer,
+            vertexCopy, renderState, null, false)));
+    }
+
+    public void SubmitOffscreenTranslatedDraw(IGuestCompiledShader pixelShader,
+        IReadOnlyList<GuestDrawTexture> textures, IReadOnlyList<GuestMemoryBuffer> globalMemoryBuffers,
+        uint attributeCount, IReadOnlyList<GuestRenderTarget> targets, IGuestCompiledShader? vertexShader = null,
+        uint vertexCount = 3, uint instanceCount = 1, uint primitiveType = 4,
+        GuestIndexBuffer? indexBuffer = null, IReadOnlyList<GuestVertexBuffer>? vertexBuffers = null,
+        GuestRenderState? renderState = null, GuestDepthTarget? depthTarget = null, ulong shaderAddress = 0)
+    {
+        if (targets.Count == 0) return;
+        EnsureStarted(targets[0].Width, targets[0].Height);
+        var ps = Spirv(pixelShader); var vs = vertexShader is null ? null : Spirv(vertexShader);
+        var textureCopy = textures.ToArray(); var memoryCopy = globalMemoryBuffers.ToArray();
+        var targetCopy = targets.ToArray(); var vertexCopy = vertexBuffers?.ToArray();
+        Enqueue(handle => Check(handle, NativeGpuPacket.SubmitDraw(handle, ps, textureCopy, memoryCopy,
+            targetCopy[0].Width, targetCopy[0].Height, attributeCount, vs, vertexCount, instanceCount,
+            primitiveType, indexBuffer, vertexCopy, renderState, targetCopy, true)));
+    }
+
+    public void SubmitDepthOnlyTranslatedDraw(IGuestCompiledShader pixelShader,
+        IReadOnlyList<GuestDrawTexture> textures, IReadOnlyList<GuestMemoryBuffer> globalMemoryBuffers,
+        uint attributeCount, GuestDepthTarget depthTarget, IGuestCompiledShader? vertexShader = null,
+        uint vertexCount = 3, uint instanceCount = 1, uint primitiveType = 4,
+        GuestIndexBuffer? indexBuffer = null, IReadOnlyList<GuestVertexBuffer>? vertexBuffers = null,
+        GuestRenderState? renderState = null, ulong shaderAddress = 0)
+    {
+        EnsureStarted(depthTarget.Width, depthTarget.Height);
+        var ps = Spirv(pixelShader); var vs = vertexShader is null ? null : Spirv(vertexShader);
+        var textureCopy = textures.ToArray(); var memoryCopy = globalMemoryBuffers.ToArray();
+        var vertexCopy = vertexBuffers?.ToArray();
+        Enqueue(handle => Check(handle, NativeGpuPacket.SubmitDraw(handle, ps, textureCopy, memoryCopy,
+            depthTarget.Width, depthTarget.Height, attributeCount, vs, vertexCount, instanceCount,
+            primitiveType, indexBuffer, vertexCopy, renderState, null, false)));
+    }
+
+    public void SubmitStorageTranslatedDraw(IGuestCompiledShader pixelShader,
+        IReadOnlyList<GuestDrawTexture> textures, IReadOnlyList<GuestMemoryBuffer> globalMemoryBuffers,
+        uint attributeCount, uint width, uint height, ulong shaderAddress = 0)
+    {
+        EnsureStarted(width, height); var ps = Spirv(pixelShader);
+        var textureCopy = textures.ToArray(); var memoryCopy = globalMemoryBuffers.ToArray();
+        GuestRenderTarget[] targets = [new(0, width, height, 12, 7)];
+        Enqueue(handle => Check(handle, NativeGpuPacket.SubmitDraw(handle, ps, textureCopy, memoryCopy,
+            width, height, attributeCount, null, 3, 1, 4, null, null, null, targets, false)));
+    }
+
+    public long SubmitComputeDispatch(ulong shaderAddress, IGuestCompiledShader computeShader,
+        IReadOnlyList<GuestDrawTexture> textures, IReadOnlyList<GuestMemoryBuffer> globalMemoryBuffers,
+        uint groupCountX, uint groupCountY, uint groupCountZ, uint baseGroupX, uint baseGroupY,
+        uint baseGroupZ, uint localSizeX, uint localSizeY, uint localSizeZ, bool isIndirect,
+        bool writesGlobalMemory, uint threadCountX = uint.MaxValue, uint threadCountY = uint.MaxValue,
+        uint threadCountZ = uint.MaxValue)
+    {
+        EnsureStarted(1280, 720); var shader = Spirv(computeShader);
+        var textureCopy = textures.ToArray(); var memoryCopy = globalMemoryBuffers.ToArray();
+        Enqueue(handle => Check(handle, NativeGpuPacket.SubmitCompute(handle, shaderAddress, shader,
+            textureCopy, memoryCopy, groupCountX, groupCountY, groupCountZ)));
+        return 0;
+    }
+
+    public bool TrySubmitGuestImage(ulong address, uint width, uint height, uint pitchInPixel)
+    {
+        EnsureStarted(width, height);
+        return Invoke(handle => NativeVulkanApi.PresentGuestImage(handle, address, width, height, pitchInPixel)) ==
+               NativeGpuResult.Success;
+    }
+
+    public bool TrySubmitOrderedGuestImageFlip(int videoOutHandle, int displayBufferIndex, ulong address,
+        uint width, uint height, uint pitchInPixel) =>
+        TrySubmitGuestImage(address, width, height, pitchInPixel);
+
+    public void RegisterKnownDisplayBuffer(ulong address, uint guestFormat)
+    {
+        EnsureStarted(1280, 720);
+        Enqueue(handle => Check(handle, NativeVulkanApi.RegisterDisplayBuffer(handle, address, guestFormat)));
+    }
+
+    public bool IsGpuGuestImageAvailable(ulong address, uint format, uint numberType)
+    {
+        EnsureStarted(1280, 720);
+        return Invoke(handle => NativeVulkanApi.HasGuestImage(handle, address, format, numberType)) ==
+               NativeGpuResult.Success;
+    }
+
+    public bool TrySubmitGuestImageBlit(ulong sourceAddress, uint sourceWidth, uint sourceHeight,
+        uint sourceFormat, uint sourceNumberType, ulong destinationAddress, uint destinationWidth,
+        uint destinationHeight, uint destinationFormat, uint destinationNumberType)
+    {
+        EnsureStarted(destinationWidth, destinationHeight);
+        return Invoke(handle => NativeVulkanApi.BlitGuestImage(handle, sourceAddress, sourceWidth, sourceHeight,
+            sourceFormat, destinationAddress, destinationWidth, destinationHeight, destinationFormat)) ==
+               NativeGpuResult.Success;
+    }
+
+    public bool TryGetRenderTargetOutputKind(uint dataFormat, uint numberType,
+        out Gen5PixelOutputKind outputKind)
+    {
+        var result = NativeVulkanApi.RenderTargetOutputKind(dataFormat, numberType, out var nativeKind);
+        outputKind = (Gen5PixelOutputKind)nativeKind; return result == NativeGpuResult.Success;
+    }
+
+    private void Run(uint width, uint height)
+    {
+        nint backend = 0;
+        try
+        {
+            if (NativeVulkanApi.GetAbiVersion() != NativeVulkanApi.AbiVersion)
+                throw new InvalidOperationException("Native Vulkan ABI version mismatch");
+            var title = Marshal.StringToCoTaskMemUTF8("SharpEmu");
+            try
+            {
+                var info = new NativeVulkanApi.CreateInfo
+                {
+                    StructSize = (uint)sizeof(NativeVulkanApi.CreateInfo), AbiVersion = NativeVulkanApi.AbiVersion,
+                    Width = width, Height = height, TitleUtf8 = (byte*)title,
+                    EnableValidation = Environment.GetEnvironmentVariable("SHARPEMU_VK_VALIDATION") == "1" ? 1u : 0u,
+                };
+                var result = NativeVulkanApi.Create(&info, out backend);
+                if (result != NativeGpuResult.Success)
+                    throw new InvalidOperationException($"se_gpu_create failed with {result}: {NativeVulkanApi.GetError(0)}");
+            }
+            finally { Marshal.FreeCoTaskMem(title); }
+            _ready.Set();
+            NativeGpuInputSource.Instance.Attach();
+            while (true)
+            {
+                if (_commands.TryTake(out var command, 8))
+                {
+                    command(backend);
+                    for (var drained = 1; drained < 128 && _commands.TryTake(out command); ++drained)
+                        command(backend);
+                }
+                var result = NativeVulkanApi.Poll(backend, out var shouldClose);
+                if (result != NativeGpuResult.Success || shouldClose != 0) break;
+                var input = new NativeVulkanApi.Input { StructSize = (uint)sizeof(NativeVulkanApi.Input) };
+                if (NativeVulkanApi.InputSnapshot(backend, &input) == NativeGpuResult.Success)
+                    NativeGpuInputSource.Instance.Update(&input);
+            }
+        }
+        catch (Exception exception)
+        {
+            _startError ??= exception;
+            Console.Error.WriteLine($"[LOADER][ERROR] Native Vulkan backend failed: {exception}");
+        }
+        finally
+        {
+            _ready.Set();
+            if (backend != 0) NativeVulkanApi.Destroy(backend);
+        }
+    }
+
+    private void Enqueue(Action<nint> command)
+    {
+        if (!_commands.TryAdd(command)) Console.Error.WriteLine("[LOADER][WARN] Native GPU queue is full; dropping work");
+    }
+
+    private NativeGpuResult Invoke(Func<nint, NativeGpuResult> operation)
+    {
+        var completion = new TaskCompletionSource<NativeGpuResult>(TaskCreationOptions.RunContinuationsAsynchronously);
+        Enqueue(handle =>
+        {
+            try { completion.SetResult(operation(handle)); }
+            catch (Exception exception) { completion.SetException(exception); }
+        });
+        return completion.Task.GetAwaiter().GetResult();
+    }
+
+    private static void Check(nint backend, NativeGpuResult result)
+    {
+        if (result is NativeGpuResult.Success or NativeGpuResult.NotReady) return;
+        Console.Error.WriteLine($"[LOADER][ERROR] Native GPU operation failed: {result}: {NativeVulkanApi.GetError(backend)}");
+    }
+
+    private static VulkanCompiledGuestShader Spirv(IGuestCompiledShader shader) =>
+        shader as VulkanCompiledGuestShader ?? throw new InvalidOperationException(
+            $"Shader type {shader.GetType().Name} was not compiled by the native Vulkan backend");
+}

src/SharpEmu.ShaderCompiler.Vulkan/SpirvFixedShaders.cs

@@ -5,6 +5,36 @@ namespace SharpEmu.ShaderCompiler.Vulkan;
 
 public static class SpirvFixedShaders
 {
+    /// <summary>Fragment half of the fixed fullscreen barycentric diagnostic draw.</summary>
+    public static byte[] CreateBarycentricFragment()
+    {
+        var module = new SpirvModuleBuilder();
+        module.AddCapability(SpirvCapability.Shader);
+        var voidType = module.TypeVoid();
+        var floatType = module.TypeFloat(32);
+        var vec4Type = module.TypeVector(floatType, 4);
+        var inputPointer = module.TypePointer(SpirvStorageClass.Input, vec4Type);
+        var outputPointer = module.TypePointer(SpirvStorageClass.Output, vec4Type);
+        var barycentric = module.AddGlobalVariable(inputPointer, SpirvStorageClass.Input);
+        module.AddName(barycentric, "barycentric");
+        module.AddDecoration(barycentric, SpirvDecoration.Location, 0);
+        module.AddDecoration(barycentric, SpirvDecoration.NoPerspective);
+        var output = module.AddGlobalVariable(outputPointer, SpirvStorageClass.Output);
+        module.AddName(output, "outColor");
+        module.AddDecoration(output, SpirvDecoration.Location, 0);
+        var functionType = module.TypeFunction(voidType);
+        var main = module.BeginFunction(voidType, functionType);
+        module.AddName(main, "main");
+        module.AddLabel();
+        var value = module.AddInstruction(SpirvOp.Load, vec4Type, barycentric);
+        module.AddStatement(SpirvOp.Store, output, value);
+        module.AddStatement(SpirvOp.Return);
+        module.EndFunction();
+        module.AddEntryPoint(SpirvExecutionModel.Fragment, main, "main", [barycentric, output]);
+        module.AddExecutionMode(main, SpirvExecutionMode.OriginUpperLeft);
+        return module.Build();
+    }
+
     public static byte[] CreateFullscreenVertex(uint attributeCount)
     {
         var module = new SpirvModuleBuilder();

tests/SharpEmu.Libs.Tests/Memory/GuestMemoryAllocatorTests.cs

@@ -95,6 +95,32 @@ public sealed class GuestMemoryAllocatorTests
         Assert.Equal(0UL, (ulong)memory.GetPointer(address));
     }
 
+    [Fact]
+    public void AlignedAllocationDoesNotRetainOverallocatedMappingsOutsideMacOS()
+    {
+        if (OperatingSystem.IsMacOS())
+        {
+            return;
+        }
+
+        const ulong desiredAddress = 0x00005000_0000_0123;
+        const ulong alignment = 0x10000;
+        const ulong alignedAddress = 0x00005000_0001_0000;
+        const ulong allocationSize = 0x2000;
+        using var host = new RelocatingHostMemory(alignedAddress);
+        using var memory = new PhysicalVirtualMemory(host);
+
+        Assert.True(memory.TryAllocateAtOrAbove(desiredAddress, 0x1234, false, alignment, out var actualAddress));
+        Assert.Equal(alignedAddress + alignment, actualAddress);
+        Assert.Equal(
+            [
+                (alignedAddress, allocationSize),
+                (alignedAddress + alignment, allocationSize),
+            ],
+            host.AllocationCalls);
+        Assert.Equal([alignedAddress + 0x1000], host.FreedAddresses);
+    }
+
     private sealed class FakeHostMemory : IHostMemory
     {
         public ulong Allocate(ulong desiredAddress, ulong size, HostPageProtection protection) =>
@@ -197,6 +223,63 @@ public sealed class GuestMemoryAllocatorTests
         }
     }
 
+    private sealed class RelocatingHostMemory(ulong firstAddress) : IHostMemory, IDisposable
+    {
+        private bool _relocatedFirstAllocation;
+
+        public List<(ulong Address, ulong Size)> AllocationCalls { get; } = [];
+
+        public List<ulong> FreedAddresses { get; } = [];
+
+        public ulong Allocate(ulong desiredAddress, ulong size, HostPageProtection protection)
+        {
+            AllocationCalls.Add((desiredAddress, size));
+            if (!_relocatedFirstAllocation)
+            {
+                _relocatedFirstAllocation = true;
+                return firstAddress + 0x1000;
+            }
+
+            return desiredAddress;
+        }
+
+        public ulong Reserve(ulong desiredAddress, ulong size, HostPageProtection protection) => 0;
+
+        public bool Commit(ulong address, ulong size, HostPageProtection protection) => true;
+
+        public bool Free(ulong address)
+        {
+            FreedAddresses.Add(address);
+            return true;
+        }
+
+        public bool Protect(ulong address, ulong size, HostPageProtection protection, out uint rawOldProtection)
+        {
+            rawOldProtection = 0;
+            return true;
+        }
+
+        public bool ProtectRaw(ulong address, ulong size, uint rawProtection, out uint rawOldProtection)
+        {
+            rawOldProtection = 0;
+            return true;
+        }
+
+        public bool Query(ulong address, out HostRegionInfo info)
+        {
+            info = default;
+            return false;
+        }
+
+        public void FlushInstructionCache(ulong address, ulong size)
+        {
+        }
+
+        public void Dispose()
+        {
+        }
+    }
+
     private sealed class LazyHostMemory(ulong address) : IHostMemory, IDisposable
     {
         public bool CommitSucceeds { get; set; } = true;