1 files changed, 102 insertions, 0 deletions
diff --git a/Userland/DevTools/UserspaceEmulator/SoftMMU.h b/Userland/DevTools/UserspaceEmulator/SoftMMU.h
new file mode 100644
index 0000000000..33351ff57b
--- /dev/null
+++ b/Userland/DevTools/UserspaceEmulator/SoftMMU.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "Region.h"
+#include "ValueWithShadow.h"
+#include <AK/HashMap.h>
+#include <AK/NonnullOwnPtrVector.h>
+#include <AK/OwnPtr.h>
+#include <AK/Types.h>
+#include <LibX86/Instruction.h>
+
+namespace UserspaceEmulator {
+
+class Emulator;
+class SharedBufferRegion;
+
+class SoftMMU {
+public:
+    explicit SoftMMU(Emulator&);
+
+    ValueWithShadow<u8> read8(X86::LogicalAddress);
+    ValueWithShadow<u16> read16(X86::LogicalAddress);
+    ValueWithShadow<u32> read32(X86::LogicalAddress);
+    ValueWithShadow<u64> read64(X86::LogicalAddress);
+
+    void write8(X86::LogicalAddress, ValueWithShadow<u8>);
+    void write16(X86::LogicalAddress, ValueWithShadow<u16>);
+    void write32(X86::LogicalAddress, ValueWithShadow<u32>);
+    void write64(X86::LogicalAddress, ValueWithShadow<u64>);
+
+    ALWAYS_INLINE Region* find_region(X86::LogicalAddress address)
+    {
+        if (address.selector() == 0x2b)
+            return m_tls_region.ptr();
+
+        size_t page_index = (address.offset() & ~(PAGE_SIZE - 1)) / PAGE_SIZE;
+        return m_page_to_region_map[page_index];
+    }
+
+    void add_region(NonnullOwnPtr<Region>);
+    void remove_region(Region&);
+
+    void set_tls_region(NonnullOwnPtr<Region>);
+
+    bool fast_fill_memory8(X86::LogicalAddress, size_t size, ValueWithShadow<u8>);
+    bool fast_fill_memory32(X86::LogicalAddress, size_t size, ValueWithShadow<u32>);
+
+    void copy_to_vm(FlatPtr destination, const void* source, size_t);
+    void copy_from_vm(void* destination, const FlatPtr source, size_t);
+    ByteBuffer copy_buffer_from_vm(const FlatPtr source, size_t);
+
+    SharedBufferRegion* shbuf_region(int shbuf_id);
+
+    template<typename Callback>
+    void for_each_region(Callback callback)
+    {
+        if (m_tls_region) {
+            if (callback(*m_tls_region) == IterationDecision::Break)
+                return;
+        }
+        for (auto& region : m_regions) {
+            if (callback(region) == IterationDecision::Break)
+                return;
+        }
+    }
+
+private:
+    Emulator& m_emulator;
+
+    Region* m_page_to_region_map[786432];
+
+    OwnPtr<Region> m_tls_region;
+    NonnullOwnPtrVector<Region> m_regions;
+    HashMap<int, Region*> m_shbuf_regions;
+};
+
+}