Adjustments on UMA

src/android/app/src/main/res/values/strings.xml

@@ -525,7 +525,7 @@
     <string name="renderer_asynchronous_shaders">Use asynchronous shaders</string>
     <string name="renderer_asynchronous_shaders_description">Compiles shaders asynchronously. This may reduce stutters but may also introduce glitches.</string>
     <string name="renderer_unified_memory">Unified memory access (UMA)</string>
-    <string name="renderer_unified_memory_description">Lets the GPU read guest memory directly for buffer uploads, skipping the CPU staging copy. Requires driver support for host memory import and is automatically disabled when unsupported.</string>
+    <string name="renderer_unified_memory_description">Allows GPU write buffer readbacks directly into guest memory, skipping the CPU staging copy.</string>
     <string name="gpu_unswizzle_settings">GPU Unswizzle Settings</string>
     <string name="gpu_unswizzle_settings_description">Configure GPU-based texture unswizzling parameters or disable it entirely. Adjust these settings to balance performance and texture loading quality.</string>
     <string name="gpu_unswizzle_enable">Enable GPU Unswizzle</string>

src/qt_common/config/shared_translation.cpp

@@ -231,9 +231,7 @@ std::unique_ptr<TranslationMap> InitializeTranslations(QObject* parent) {
     INSERT(Settings, use_asynchronous_shaders, tr("Enable asynchronous shader compilation"),
            tr("May reduce shader stutter."));
     INSERT(Settings, use_unified_memory, tr("Enable unified memory access (UMA)"),
-           tr("Lets the GPU read guest memory directly for buffer uploads, skipping the CPU "
+           tr("Lets the GPU write buffer readbacks directly into guest memory."));
-              "staging copy.\nRequires driver support for host memory import and may cause "
-              "issues in some games."));
     INSERT(Settings, pipeline_worker_count, tr("Pipeline Worker Threads"),
            tr("Number of threads used to build Vulkan pipelines.\n"
               "Higher values speed up compilation at the cost of heat and power."));

src/video_core/buffer_cache/buffer_cache.h

@@ -1815,53 +1815,73 @@ void BufferCache<P>::ImmediateUploadMemory([[maybe_unused]] Buffer& buffer,
 }
 
 template <class P>
-bool BufferCache<P>::TryUnifiedUploadMemory([[maybe_unused]] Buffer& buffer,
+bool BufferCache<P>::TryUnifiedDownloadMemory([[maybe_unused]] Buffer& buffer,
-                                            [[maybe_unused]] std::span<BufferCopy> copies) {
+                                              [[maybe_unused]] std::span<BufferCopy> copies) {
     if constexpr (USE_UNIFIED_MEMORY) {
-        boost::container::small_vector<BufferCopy, 16> host_copies;
         const u8* const physical_base = device_memory.GetPhysicalBase();
         const u64 unified_size = runtime.UnifiedMemorySize();
+        const u64 window_size = runtime.UnifiedMemoryWindowSize();
+        if (window_size == 0) {
+            return false;
+        }
+        boost::container::small_vector<u64, 4> window_ids;
+        boost::container::small_vector<boost::container::small_vector<BufferCopy, 16>, 4> groups;
+        const auto group_for = [&](u64 window) -> boost::container::small_vector<BufferCopy, 16>& {
+            for (size_t i = 0; i < window_ids.size(); ++i) {
+                if (window_ids[i] == window) {
+                    return groups[i];
+                }
+            }
+            window_ids.push_back(window);
+            groups.emplace_back();
+            return groups.back();
+        };
         for (const BufferCopy& copy : copies) {
-            const DAddr device_addr = buffer.CpuAddr() + copy.dst_offset;
+            const DAddr device_addr = buffer.CpuAddr() + copy.src_offset;
-            u64 uploaded = 0;
+            u64 downloaded = 0;
-            while (uploaded < copy.size) {
+            while (downloaded < copy.size) {
-                const DAddr page_addr = device_addr + uploaded;
+                const DAddr page_addr = device_addr + downloaded;
                 const u8* const ptr = device_memory.GetPointer<u8>(page_addr);
                 if (ptr == nullptr) {
                     return false;
                 }
                 const u64 page_offset = page_addr & Core::DEVICE_PAGEMASK;
-                const u64 chunk = (std::min)(copy.size - uploaded,
+                u64 chunk = (std::min)(copy.size - downloaded,
-                                             static_cast<u64>(Core::DEVICE_PAGESIZE) - page_offset);
+                                       static_cast<u64>(Core::DEVICE_PAGESIZE) - page_offset);
-                const u64 src_offset = static_cast<u64>(ptr - physical_base);
+                const u64 phys_offset = static_cast<u64>(ptr - physical_base);
-                if (src_offset + chunk > unified_size) {
+                if (phys_offset + chunk > unified_size) {
                     return false;
                 }
-                if (!host_copies.empty()) {
+                const u64 window = phys_offset / window_size;
-                    BufferCopy& last = host_copies.back();
+                const u64 local_offset = phys_offset % window_size;
-                    if (last.src_offset + last.size == src_offset &&
+                chunk = (std::min)(chunk, window_size - local_offset);
-                        last.dst_offset + last.size == copy.dst_offset + uploaded) {
+                auto& group = group_for(window);
+                if (!group.empty()) {
+                    BufferCopy& last = group.back();
+                    if (last.src_offset + last.size == copy.src_offset + downloaded &&
+                        last.dst_offset + last.size == local_offset) {
                         last.size += chunk;
-                        uploaded += chunk;
+                        downloaded += chunk;
                         continue;
                     }
                 }
-                host_copies.push_back(BufferCopy{
+                group.push_back(BufferCopy{
-                    .src_offset = src_offset,
+                    .src_offset = copy.src_offset + downloaded,
-                    .dst_offset = copy.dst_offset + uploaded,
+                    .dst_offset = local_offset,
                     .size = chunk,
                 });
-                uploaded += chunk;
+                downloaded += chunk;
             }
         }
         for (const BufferCopy& copy : copies) {
-            if (Settings::values.enable_gpu_buffer_readback.GetValue()) {
+            buffer.MarkUsage(copy.src_offset, copy.size);
-                DownloadBufferMemory(buffer, buffer.CpuAddr() + copy.dst_offset, copy.size);
-            }
         }
-        const std::span<BufferCopy> host_span(host_copies.data(), host_copies.size());
+        for (size_t i = 0; i < window_ids.size(); ++i) {
-        const bool can_reorder = runtime.CanReorderUpload(buffer, host_span);
+            const std::span<BufferCopy> group_span(groups[i].data(), groups[i].size());
-        runtime.CopyBuffer(buffer, runtime.UnifiedMemoryBuffer(), host_span, true, can_reorder);
+            runtime.CopyBuffer(runtime.UnifiedMemoryWindowBuffer(window_ids[i]), buffer,
+                               group_span, true);
+        }
+        runtime.Finish();
         return true;
     } else {
         return false;
@@ -1873,11 +1893,6 @@ void BufferCache<P>::MappedUploadMemory([[maybe_unused]] Buffer& buffer,
                                         [[maybe_unused]] u64 total_size_bytes,
                                         [[maybe_unused]] std::span<BufferCopy> copies) {
     if constexpr (USE_MEMORY_MAPS) {
-        if constexpr (USE_UNIFIED_MEMORY) {
-            if (runtime.HasUnifiedMemory() && TryUnifiedUploadMemory(buffer, copies)) {
-                return;
-            }
-        }
         auto upload_staging = runtime.UploadStagingBuffer(total_size_bytes);
         const std::span<u8> staging_pointer = upload_staging.mapped_span;
         for (BufferCopy& copy : copies) {
@@ -1976,6 +1991,12 @@ void BufferCache<P>::DownloadBufferMemory(Buffer& buffer, DAddr device_addr, u64
     }
 
     if constexpr (USE_MEMORY_MAPS) {
+        if constexpr (USE_UNIFIED_MEMORY) {
+            if (runtime.HasUnifiedMemory() &&
+                TryUnifiedDownloadMemory(buffer, std::span(copies.data(), copies.size()))) {
+                return;
+            }
+        }
         auto download_staging = runtime.DownloadStagingBuffer(total_size_bytes);
         const u8* const mapped_memory = download_staging.mapped_span.data();
         const std::span<BufferCopy> copies_span(copies.data(), copies.data() + copies.size());

src/video_core/buffer_cache/buffer_cache_base.h

@@ -451,7 +451,7 @@ private:
 
     void MappedUploadMemory(Buffer& buffer, u64 total_size_bytes, std::span<BufferCopy> copies);
 
-    bool TryUnifiedUploadMemory(Buffer& buffer, std::span<BufferCopy> copies);
+    bool TryUnifiedDownloadMemory(Buffer& buffer, std::span<BufferCopy> copies);
 
     void DownloadBufferMemory(Buffer& buffer_id);
 

src/video_core/renderer_vulkan/vk_buffer_cache.h

@@ -104,14 +104,18 @@ public:
         return unified_memory != nullptr && unified_memory->IsValid();
     }
 
-    [[nodiscard]] VkBuffer UnifiedMemoryBuffer() const noexcept {
-        return unified_memory ? unified_memory->GetBuffer() : VK_NULL_HANDLE;
-    }
-
     [[nodiscard]] u64 UnifiedMemorySize() const noexcept {
         return unified_memory ? unified_memory->GetSize() : 0;
     }
 
+    [[nodiscard]] u64 UnifiedMemoryWindowSize() const noexcept {
+        return unified_memory ? unified_memory->GetWindowSize() : 0;
+    }
+
+    [[nodiscard]] VkBuffer UnifiedMemoryWindowBuffer(size_t index) const noexcept {
+        return unified_memory ? unified_memory->GetWindowBuffer(index) : VK_NULL_HANDLE;
+    }
+
     u64 CurrentTick();
 
     u64 KnownGpuTick();

src/video_core/vulkan_common/vulkan_memory_allocator.cpp

@@ -83,52 +83,21 @@ namespace Vulkan {
                      alignment);
             return;
         }
+        using namespace Common::Literals;
+        VkDeviceSize candidate_window = 1_GiB;
         const u64 max_buffer_size = device.GetMaxBufferSize();
-        if (max_buffer_size != 0 && max_buffer_size < size) {
+        if (max_buffer_size != 0 && max_buffer_size < candidate_window) {
-            size = static_cast<size_t>(Common::AlignDown(max_buffer_size, alignment));
+            candidate_window = Common::AlignDown(max_buffer_size, alignment);
-            if (size == 0) {
-                return;
-            }
         }
+        if (candidate_window == 0) {
+            return;
+        }
+        window_size = candidate_window;
+
         const auto &logical = device.GetLogical();
-        VkMemoryHostPointerPropertiesEXT host_props{
-                .sType = VK_STRUCTURE_TYPE_MEMORY_HOST_POINTER_PROPERTIES_EXT,
-                .pNext = nullptr,
-                .memoryTypeBits = 0,
-        };
-        if (logical.GetMemoryHostPointerPropertiesEXT(
-                    VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT, base, &host_props) !=
-                    VK_SUCCESS ||
-            host_props.memoryTypeBits == 0) {
-            return;
-        }
-        const VkExternalMemoryBufferCreateInfo external_info{
-                .sType = VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_BUFFER_CREATE_INFO,
-                .pNext = nullptr,
-                .handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT,
-        };
-        const VkBufferCreateInfo buffer_ci{
-                .sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
-                .pNext = &external_info,
-                .flags = 0,
-                .size = size,
-                .usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT,
-                .sharingMode = VK_SHARING_MODE_EXCLUSIVE,
-                .queueFamilyIndexCount = 0,
-                .pQueueFamilyIndices = nullptr,
-        };
-        VkBuffer new_buffer{};
-        if (logical.CreateBufferRaw(buffer_ci, &new_buffer) != VK_SUCCESS) {
-            return;
-        }
-        const VkMemoryRequirements requirements = logical.GetBufferMemoryRequirements(new_buffer);
-        const u32 type_mask = requirements.memoryTypeBits & host_props.memoryTypeBits;
-        if (type_mask == 0 || requirements.size > size) {
-            logical.DestroyBufferRaw(new_buffer);
-            return;
-        }
         const auto memory_props = device.GetPhysical().GetMemoryProperties().memoryProperties;
-        const auto find_type = [&](VkMemoryPropertyFlags wanted) -> std::optional<u32> {
+        const auto find_type = [&](u32 type_mask, VkMemoryPropertyFlags wanted)
+                -> std::optional<u32> {
             for (u32 i = 0; i < memory_props.memoryTypeCount; ++i) {
                 if (((type_mask >> i) & 1u) != 0 &&
                     (memory_props.memoryTypes[i].propertyFlags & wanted) == wanted) {
@@ -137,48 +106,100 @@ namespace Vulkan {
             }
             return std::nullopt;
         };
-        auto type_index = find_type(VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT |
+
-                                    VK_MEMORY_PROPERTY_HOST_COHERENT_BIT |
+        for (size_t offset = 0; offset < size; offset += window_size) {
-                                    VK_MEMORY_PROPERTY_HOST_CACHED_BIT);
+            u8 *const window_base = static_cast<u8 *>(base) + offset;
-        if (!type_index) {
+            const VkDeviceSize window_len =
-            type_index = find_type(VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT |
+                    (std::min)(static_cast<VkDeviceSize>(size - offset), window_size);
-                                   VK_MEMORY_PROPERTY_HOST_COHERENT_BIT);
+            VkMemoryHostPointerPropertiesEXT host_props{
+                    .sType = VK_STRUCTURE_TYPE_MEMORY_HOST_POINTER_PROPERTIES_EXT,
+                    .pNext = nullptr,
+                    .memoryTypeBits = 0,
+            };
+            if (logical.GetMemoryHostPointerPropertiesEXT(
+                        VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT, window_base,
+                        &host_props) != VK_SUCCESS ||
+                host_props.memoryTypeBits == 0) {
+                break;
+            }
+            const VkExternalMemoryBufferCreateInfo external_info{
+                    .sType = VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_BUFFER_CREATE_INFO,
+                    .pNext = nullptr,
+                    .handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT,
+            };
+            const VkBufferCreateInfo buffer_ci{
+                    .sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
+                    .pNext = &external_info,
+                    .flags = 0,
+                    .size = window_len,
+                    .usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT,
+                    .sharingMode = VK_SHARING_MODE_EXCLUSIVE,
+                    .queueFamilyIndexCount = 0,
+                    .pQueueFamilyIndices = nullptr,
+            };
+            VkBuffer new_buffer{};
+            if (logical.CreateBufferRaw(buffer_ci, &new_buffer) != VK_SUCCESS) {
+                break;
+            }
+            const VkMemoryRequirements requirements =
+                    logical.GetBufferMemoryRequirements(new_buffer);
+            const u32 type_mask = requirements.memoryTypeBits & host_props.memoryTypeBits;
+            if (type_mask == 0 || requirements.size > window_len) {
+                logical.DestroyBufferRaw(new_buffer);
+                break;
+            }
+            auto type_index = find_type(type_mask, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT |
+                                                           VK_MEMORY_PROPERTY_HOST_COHERENT_BIT |
+                                                           VK_MEMORY_PROPERTY_HOST_CACHED_BIT);
+            if (!type_index) {
+                type_index = find_type(type_mask, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT |
+                                                          VK_MEMORY_PROPERTY_HOST_COHERENT_BIT);
+            }
+            if (!type_index) {
+                logical.DestroyBufferRaw(new_buffer);
+                break;
+            }
+            const VkImportMemoryHostPointerInfoEXT import_info{
+                    .sType = VK_STRUCTURE_TYPE_IMPORT_MEMORY_HOST_POINTER_INFO_EXT,
+                    .pNext = nullptr,
+                    .handleType = VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT,
+                    .pHostPointer = window_base,
+            };
+            const VkMemoryAllocateInfo alloc_info{
+                    .sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
+                    .pNext = &import_info,
+                    .allocationSize = window_len,
+                    .memoryTypeIndex = *type_index,
+            };
+            vk::DeviceMemory memory = logical.TryAllocateMemory(alloc_info);
+            if (!memory) {
+                logical.DestroyBufferRaw(new_buffer);
+                break;
+            }
+            if (logical.BindBufferMemory(new_buffer, *memory, 0) != VK_SUCCESS) {
+                logical.DestroyBufferRaw(new_buffer);
+                break;
+            }
+            windows.push_back(Window{
+                    .memory = std::move(memory),
+                    .buffer = new_buffer,
+            });
+            imported_size += static_cast<size_t>(window_len);
         }
-        if (!type_index) {
+        if (windows.empty()) {
-            logical.DestroyBufferRaw(new_buffer);
+            LOG_INFO(Render_Vulkan, "Unified memory disabled, host memory import failed");
             return;
         }
-        const VkImportMemoryHostPointerInfoEXT import_info{
+        LOG_INFO(Render_Vulkan,
-                .sType = VK_STRUCTURE_TYPE_IMPORT_MEMORY_HOST_POINTER_INFO_EXT,
+                 "Imported {} MiB of guest memory for unified memory access in {} windows",
-                .pNext = nullptr,
+                 imported_size >> 20, windows.size());
-                .handleType = VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT,
-                .pHostPointer = base,
-        };
-        const VkMemoryAllocateInfo alloc_info{
-                .sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
-                .pNext = &import_info,
-                .allocationSize = size,
-                .memoryTypeIndex = *type_index,
-        };
-        memory = logical.TryAllocateMemory(alloc_info);
-        if (!memory) {
-            logical.DestroyBufferRaw(new_buffer);
-            return;
-        }
-        if (logical.BindBufferMemory(new_buffer, *memory, 0) != VK_SUCCESS) {
-            logical.DestroyBufferRaw(new_buffer);
-            memory = vk::DeviceMemory{};
-            return;
-        }
-        buffer = new_buffer;
-        imported_size = size;
-        LOG_INFO(Render_Vulkan, "Imported {} MiB of guest memory for unified memory access",
-                 size >> 20);
     }
 
     HostMemoryImport::~HostMemoryImport() {
-        if (buffer != VK_NULL_HANDLE) {
+        for (Window &window : windows) {
-            device.GetLogical().DestroyBufferRaw(buffer);
+            if (window.buffer != VK_NULL_HANDLE) {
+                device.GetLogical().DestroyBufferRaw(window.buffer);
+            }
         }
     }
 

src/video_core/vulkan_common/vulkan_memory_allocator.h

@@ -51,21 +51,34 @@ namespace Vulkan {
         HostMemoryImport &operator=(const HostMemoryImport &) = delete;
 
         [[nodiscard]] bool IsValid() const noexcept {
-            return buffer != VK_NULL_HANDLE;
+            return !windows.empty();
-        }
-
-        [[nodiscard]] VkBuffer GetBuffer() const noexcept {
-            return buffer;
         }
 
         [[nodiscard]] size_t GetSize() const noexcept {
             return imported_size;
         }
 
+        [[nodiscard]] VkDeviceSize GetWindowSize() const noexcept {
+            return window_size;
+        }
+
+        [[nodiscard]] VkBuffer GetWindowBuffer(size_t index) const noexcept {
+            return windows[index].buffer;
+        }
+
+        [[nodiscard]] size_t GetWindowCount() const noexcept {
+            return windows.size();
+        }
+
     private:
+        struct Window {
+            vk::DeviceMemory memory;
+            VkBuffer buffer{};
+        };
+
         const Device &device;
-        vk::DeviceMemory memory;
+        std::vector<Window> windows;
-        VkBuffer buffer{};
+        VkDeviceSize window_size{};
         size_t imported_size{};
     };