From 422246825bea29aa3e3c00183cafc341f1a32374 Mon Sep 17 00:00:00 2001
From: Nekotekina <nekotekina@gmail.com>
Date: Tue, 31 May 2022 21:03:36 +0300
Subject: [PATCH] vm: workaround bigger native page size for 4k pages

Always allocate full memory block if native page size > 4k
---
 rpcs3/Emu/Memory/vm.cpp | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/rpcs3/Emu/Memory/vm.cpp b/rpcs3/Emu/Memory/vm.cpp
index b750d86f5b..54e8a8676a 100644
--- a/rpcs3/Emu/Memory/vm.cpp
+++ b/rpcs3/Emu/Memory/vm.cpp
@@ -609,7 +609,7 @@ namespace vm
 		thread_ctrl::emergency_exit("vm::reservation_escape");
 	}
 
-	static void _page_map(u32 addr, u8 flags, u32 size, utils::shm* shm, std::pair<const u32, std::pair<u32, std::shared_ptr<utils::shm>>>* (*search_shm)(vm::block_t* block, utils::shm* shm))
+	static void _page_map(u32 addr, u8 flags, u32 size, utils::shm* shm, u64 bflags, std::pair<const u32, std::pair<u32, std::shared_ptr<utils::shm>>>* (*search_shm)(vm::block_t* block, utils::shm* shm))
 	{
 		perf_meter<"PAGE_MAP"_u64> perf0;
 
@@ -626,6 +626,9 @@ namespace vm
 			}
 		}
 
+		// If native page size exceeds 4096, don't map native pages (expected to be always mapped in this case)
+		const bool is_noop = bflags & page_size_4k && utils::c_page_size > 4096;
+
 		// Lock range being mapped
 		_lock_main_range_lock(range_allocation, addr, size);
 
@@ -694,7 +697,10 @@ namespace vm
 		if (~flags & page_readable)
 			prot = utils::protection::no;
 
-		if (!shm)
+		if (is_noop)
+		{
+		}
+		else if (!shm)
 		{
 			utils::memory_protect(g_base_addr + addr, size, prot);
 		}
@@ -703,7 +709,7 @@ namespace vm
 			fmt::throw_exception("Memory mapping failed - blame Windows (addr=0x%x, size=0x%x, flags=0x%x)", addr, size, flags);
 		}
 
-		if (flags & page_executable)
+		if (flags & page_executable && !is_noop)
 		{
 			// TODO (dead code)
 			utils::memory_commit(g_exec_addr + addr * 2, size * 2);
@@ -800,7 +806,7 @@ namespace vm
 		return true;
 	}
 
-	static u32 _page_unmap(u32 addr, u32 max_size, utils::shm* shm)
+	static u32 _page_unmap(u32 addr, u32 max_size, u64 bflags, utils::shm* shm)
 	{
 		perf_meter<"PAGE_UNm"_u64> perf0;
 
@@ -809,6 +815,9 @@ namespace vm
 			fmt::throw_exception("Invalid arguments (addr=0x%x, max_size=0x%x)", addr, max_size);
 		}
 
+		// If native page size exceeds 4096, don't unmap native pages (always mapped)
+		const bool is_noop = bflags & page_size_4k && utils::c_page_size > 4096;
+
 		// Determine deallocation size
 		u32 size = 0;
 		bool is_exec = false;
@@ -868,7 +877,11 @@ namespace vm
 		ppu_remove_hle_instructions(addr, size);
 
 		// Actually unmap memory
-		if (!shm)
+		if (is_noop)
+		{
+			std::memset(g_sudo_addr + addr, 0, size);
+		}
+		else if (!shm)
 		{
 			utils::memory_protect(g_base_addr + addr, size, utils::protection::no);
 			std::memset(g_sudo_addr + addr, 0, size);
@@ -881,7 +894,7 @@ namespace vm
 #endif
 		}
 
-		if (is_exec)
+		if (is_exec && !is_noop)
 		{
 			utils::memory_decommit(g_exec_addr + addr * 2, size * 2);
 
@@ -1045,7 +1058,7 @@ namespace vm
 		}
 
 		// Map "real" memory pages; provide a function to search for mirrors with private member access
-		_page_map(page_addr, flags, page_size, shm.get(), [](vm::block_t* _this, utils::shm* shm)
+		_page_map(page_addr, flags, page_size, shm.get(), this->flags, [](vm::block_t* _this, utils::shm* shm)
 		{
 			auto& map = (_this->m.*block_map)();
 
@@ -1127,7 +1140,7 @@ namespace vm
 		{
 			// Special path for whole-allocated areas allowing 4k granularity
 			m_common = std::make_shared<utils::shm>(size);
-			m_common->map_critical(vm::base(addr), utils::protection::no);
+			m_common->map_critical(vm::base(addr), this->flags & page_size_4k && utils::c_page_size > 4096 ? utils::protection::rw : utils::protection::no);
 			m_common->map_critical(vm::get_super_ptr(addr));
 		}
 	}
@@ -1143,7 +1156,7 @@ namespace vm
 			{
 				const auto next = std::next(it);
 				const auto size = it->second.first;
-				_page_unmap(it->first, size, it->second.second.get());
+				_page_unmap(it->first, size, this->flags, it->second.second.get());
 				it = next;
 			}
 
@@ -1328,7 +1341,7 @@ namespace vm
 			}
 
 			// Unmap "real" memory pages
-			ensure(size == _page_unmap(addr, size, found->second.second.get()));
+			ensure(size == _page_unmap(addr, size, this->flags, found->second.second.get()));
 
 			// Clear stack guards
 			if (flags & stack_guarded)