From 649d372f7da8559f8b6d74ca44af64ba7d7853c4 Mon Sep 17 00:00:00 2001
From: Mary <mary@mary.zone>
Date: Tue, 20 Jun 2023 17:33:54 +0200
Subject: misc: Implement address space size workarounds (#5191)

* misc: Implement address space size workarounds

This adds code to support userland with less than 39 bits of address
space available by testing reserving multiple sizes and reducing
guess address space when needed.

This is required for ARM64 support when the kernel is
configured to use 63..39 bits for kernel space.(meaning only 38 bits is available to userland)

* Address comments

* Fix 32 bits address space support and address more comments
---
 src/Ryujinx.Cpu/Jit/MemoryManagerHostMapped.cs | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

(limited to 'src/Ryujinx.Cpu/Jit/MemoryManagerHostMapped.cs')

diff --git a/src/Ryujinx.Cpu/Jit/MemoryManagerHostMapped.cs b/src/Ryujinx.Cpu/Jit/MemoryManagerHostMapped.cs
index 363f9000..3686eb08 100644
--- a/src/Ryujinx.Cpu/Jit/MemoryManagerHostMapped.cs
+++ b/src/Ryujinx.Cpu/Jit/MemoryManagerHostMapped.cs
@@ -38,7 +38,8 @@ namespace Ryujinx.Cpu.Jit
         private readonly bool _unsafeMode;
 
         private readonly AddressSpace _addressSpace;
-        private readonly ulong _addressSpaceSize;
+
+        public ulong AddressSpaceSize { get; }
 
         private readonly PageTable<ulong> _pageTable;
 
@@ -62,21 +63,21 @@ namespace Ryujinx.Cpu.Jit
         /// <summary>
         /// Creates a new instance of the host mapped memory manager.
         /// </summary>
-        /// <param name="backingMemory">Physical backing memory where virtual memory will be mapped to</param>
-        /// <param name="addressSpaceSize">Size of the address space</param>
+        /// <param name="addressSpace">Address space instance to use</param>
         /// <param name="unsafeMode">True if unmanaged access should not be masked (unsafe), false otherwise.</param>
         /// <param name="invalidAccessHandler">Optional function to handle invalid memory accesses</param>
-        public MemoryManagerHostMapped(MemoryBlock backingMemory, ulong addressSpaceSize, bool unsafeMode, InvalidAccessHandler invalidAccessHandler = null)
+        public MemoryManagerHostMapped(AddressSpace addressSpace, bool unsafeMode, InvalidAccessHandler invalidAccessHandler)
         {
+            _addressSpace = addressSpace;
             _pageTable = new PageTable<ulong>();
             _invalidAccessHandler = invalidAccessHandler;
             _unsafeMode = unsafeMode;
-            _addressSpaceSize = addressSpaceSize;
+            AddressSpaceSize = addressSpace.AddressSpaceSize;
 
             ulong asSize = PageSize;
             int asBits = PageBits;
 
-            while (asSize < addressSpaceSize)
+            while (asSize < AddressSpaceSize)
             {
                 asSize <<= 1;
                 asBits++;
@@ -86,8 +87,6 @@ namespace Ryujinx.Cpu.Jit
 
             _pageBitmap = new ulong[1 << (AddressSpaceBits - (PageBits + PageToPteShift))];
 
-            _addressSpace = new AddressSpace(backingMemory, asSize, Supports4KBPages);
-
             Tracking = new MemoryTracking(this, (int)MemoryBlock.GetPageSize(), invalidAccessHandler);
             _memoryEh = new MemoryEhMeilleure(_addressSpace.Base, _addressSpace.Mirror, Tracking);
         }
@@ -99,7 +98,7 @@ namespace Ryujinx.Cpu.Jit
         /// <returns>True if the virtual address is part of the addressable space</returns>
         private bool ValidateAddress(ulong va)
         {
-            return va < _addressSpaceSize;
+            return va < AddressSpaceSize;
         }
 
         /// <summary>
@@ -111,7 +110,7 @@ namespace Ryujinx.Cpu.Jit
         private bool ValidateAddressAndSize(ulong va, ulong size)
         {
             ulong endVa = va + size;
-            return endVa >= va && endVa >= size && endVa <= _addressSpaceSize;
+            return endVa >= va && endVa >= size && endVa <= AddressSpaceSize;
         }
 
         /// <summary>
-- 
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