From 844cc6e2ed8d288fd8ebca0aa03072f774c529d6 Mon Sep 17 00:00:00 2001
From: "Herman S." <429230+has207@users.noreply.github.com>
Date: Wed, 8 Apr 2026 09:07:32 +0900
Subject: [PATCH] [Memory] Remove unnecessary 256MB carve-out from v00000000
 virtual heap

The 4KB-page virtual heap (v00000000, 0x00000000-0x3FFFFFFF) had 256MB
reserved at its top end for thread stacks, but thread stacks only use
the 64KB-page heap (v40000000) at 0x70000000-0x7F000000. This wasted
256MB of allocatable address space.

Keep the carve-out only on the v40000000 heap where stacks actually reside.
---
 src/xenia/memory.cc | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/src/xenia/memory.cc b/src/xenia/memory.cc
index f1a1e32f7..9c9b7af43 100644
--- a/src/xenia/memory.cc
+++ b/src/xenia/memory.cc
@@ -1044,17 +1044,12 @@ bool BaseHeap::Alloc(uint32_t size, uint32_t alignment,
   size = xe::round_up(size, page_size_);
   alignment = xe::round_up(alignment, page_size_);
 
-  // TODO(Gliniak): Find better way to deal with this!
-  // Because 0x3XXXXXX and 0x7XXXXXX is used strictly as place for thread stacks
-  // 0x3 is probably for system threads and 0x7 for title threads
+  // Exclude the top 240MB of the v40000000 heap (64KB guest pages) from
+  // general allocation to protect the thread stack region
+  // (0x70000000-0x7F000000)
   uint32_t heap_virtual_guest_offset = 0;
-  if (heap_type_ == HeapType::kGuestVirtual) {
-    heap_virtual_guest_offset = 0x10000000;
-
-    // Adjust for 64k pages region, to prevent having a bit too little memory
-    if (page_size_ == 0x10000) {
-      heap_virtual_guest_offset = 0x0F000000;
-    }
+  if (heap_type_ == HeapType::kGuestVirtual && page_size_ == 0x10000) {
+    heap_virtual_guest_offset = 0x0F000000;
   }
 
   uint32_t low_address = heap_base_;