dma step ondemand flush

src/video_core/dma_pusher.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
@@ -83,14 +83,39 @@ bool DmaPusher::Step() {
     }
 
     if (header.size > 0) {
-        if (Settings::IsDMALevelDefault() ? (Settings::IsGPULevelMedium() || Settings::IsGPULevelHigh()) : Settings::IsDMALevelSafe()) {
-            Tegra::Memory::GpuGuestMemory<Tegra::CommandHeader, Tegra::Memory::GuestMemoryFlags::SafeRead>headers(memory_manager, dma_state.dma_get, header.size, &command_headers);
+        if (Settings::getDebugKnobAt(0)) {
+            const size_t command_bytes = static_cast<size_t>(header.size) * sizeof(CommandHeader);
+
+            if (memory_manager.IsMemoryDirty(dma_state.dma_get, command_bytes)) {
+                memory_manager.FlushRegion(dma_state.dma_get, command_bytes);
+            }
+
+            command_headers.resize_destructive(header.size);
+            if (Settings::IsDMALevelDefault()
+                    ? (Settings::IsGPULevelMedium() || Settings::IsGPULevelHigh())
+                    : Settings::IsDMALevelSafe()) {
+                memory_manager.ReadBlock(dma_state.dma_get, command_headers.data(), command_bytes);
+            } else {
+                memory_manager.ReadBlockUnsafe(dma_state.dma_get, command_headers.data(),
+                                               command_bytes);
+            }
+            ProcessCommands(command_headers);
+        } else {
+            if (Settings::IsDMALevelDefault()
+                    ? (Settings::IsGPULevelMedium() || Settings::IsGPULevelHigh())
+                    : Settings::IsDMALevelSafe()) {
+                Tegra::Memory::GpuGuestMemory<Tegra::CommandHeader,
+                                              Tegra::Memory::GuestMemoryFlags::SafeRead>
+                    headers(memory_manager, dma_state.dma_get, header.size, &command_headers);
                 ProcessCommands(headers);
             } else {
-            Tegra::Memory::GpuGuestMemory<Tegra::CommandHeader, Tegra::Memory::GuestMemoryFlags::UnsafeRead>headers(memory_manager, dma_state.dma_get, header.size, &command_headers);
+                Tegra::Memory::GpuGuestMemory<Tegra::CommandHeader,
+                                              Tegra::Memory::GuestMemoryFlags::UnsafeRead>
+                    headers(memory_manager, dma_state.dma_get, header.size, &command_headers);
                 ProcessCommands(headers);
             }
         }
+    }
 
     if (++dma_pushbuffer_subindex >= command_list_size) {
         dma_pushbuffer.pop();