revert ee3d858935

revert Follow Up Of the previous commit with the update of TLB update

src/core/arm/nce/arm_nce.cpp

@@ -170,54 +170,29 @@ bool ArmNce::HandleGuestAccessFault(GuestContext* guest_ctx, void* raw_info, voi
     // Get the ArmNce instance from the guest context
     ArmNce* nce = guest_ctx->parent;
 
-    // Define a maximum retry count to prevent infinite loops
-    constexpr int max_retries = 3;
-    int retry_count = 0;
-
-    while (retry_count < max_retries) {
-        // Check TLB first
-        if (TlbEntry* entry = nce->FindTlbEntry(fault_addr)) {
-            if (!entry->writable && info->si_code == SEGV_ACCERR) {
-                LOG_DEBUG(Core_ARM, "Write to read-only memory at {:X}", fault_addr);
-                return HandleFailedGuestFault(guest_ctx, raw_info, raw_context);
-            }
-            return true;
-        }
-
-        // TLB miss handling with better error checking
-        if (memory.InvalidateNCE(fault_addr, Memory::CITRON_PAGESIZE)) {
-            const u64 host_addr = reinterpret_cast<u64>(memory.GetPointer(fault_addr));
-
-            if (host_addr) {
-                nce->AddTlbEntry(fault_addr, host_addr, Memory::CITRON_PAGESIZE, true);
-                return true;
-            } else {
-                LOG_DEBUG(Core_ARM, "Failed to get host address for guest address {:X}", fault_addr);
-            }
-        } else {
-            LOG_DEBUG(Core_ARM, "Memory invalidation failed for address {:X}", fault_addr);
-        }
-
-        // Trigger an immediate remap if lookup fails
-        if (!memory.Remap(fault_addr, Memory::CITRON_PAGESIZE)) {
-            LOG_ERROR(Core_ARM, "Immediate remap failed for address {:X}", fault_addr);
+    // Check TLB first
+    if (TlbEntry* entry = nce->FindTlbEntry(fault_addr)) {
+        if (!entry->writable && info->si_code == SEGV_ACCERR) {
+            LOG_DEBUG(Core_ARM, "Write to read-only memory at {:X}", fault_addr);
             return HandleFailedGuestFault(guest_ctx, raw_info, raw_context);
         }
+        return true;
+    }
 
-        // Retry adding the TLB entry after remap
+    // TLB miss handling with better error checking
+    if (memory.InvalidateNCE(fault_addr, Memory::CITRON_PAGESIZE)) {
         const u64 host_addr = reinterpret_cast<u64>(memory.GetPointer(fault_addr));
+
         if (host_addr) {
             nce->AddTlbEntry(fault_addr, host_addr, Memory::CITRON_PAGESIZE, true);
             return true;
         } else {
-            LOG_ERROR(Core_ARM, "Failed to get host address after remap for guest address {:X}", fault_addr);
+            LOG_DEBUG(Core_ARM, "Failed to get host address for guest address {:X}", fault_addr);
         }
-
-        // Increment the retry count
-        retry_count++;
+    } else {
+        LOG_DEBUG(Core_ARM, "Memory invalidation failed for address {:X}", fault_addr);
     }
 
-    // If all retries fail, handle the fault as a failed guest fault
     return HandleFailedGuestFault(guest_ctx, raw_info, raw_context);
 }
 
@@ -443,7 +418,6 @@ TlbEntry* ArmNce::FindTlbEntry(u64 guest_addr) {
             if (entry.access_count < 1000) { // Prevent overflow
                 entry.access_count++;
             }
-            entry.ref_count++; // Increment reference count
             return &entry;
         }
     }
@@ -500,8 +474,7 @@ void ArmNce::AddTlbEntry(u64 guest_addr, u64 host_addr, u32 size, bool writable)
         .valid = true,
         .writable = writable,
         .access_count = 1,
-        .last_access_time = now,
-        .ref_count = 1 // Initialize reference count
+        .last_access_time = now // Update the access time
     };
 }
 
@@ -536,7 +509,6 @@ struct TlbEntry {
     bool writable;
     u32 access_count;
     std::chrono::steady_clock::time_point last_access_time; // Add this line
-    u32 ref_count; // Add this line
 };
 
 } // namespace Core

src/core/memory.cpp

@@ -1151,51 +1151,4 @@ bool Memory::InvalidateSeparateHeap(void* fault_address) {
 #endif
 }
 
-bool Memory::Remap(u64 guest_addr, u32 size) {
-    // Unmap the old address
-    UnmapRegion(*impl->current_page_table, guest_addr, size, false);
-
-    // Reclaim memory from unreferenced pages
-    ReclaimUnusedMemory();
-
-    // Allocate new memory
-    void* new_memory = std::malloc(size);
-    if (!new_memory) {
-        LOG_ERROR(Core_Memory, "Failed to allocate new memory for remapping address {:X}", guest_addr);
-        return false;
-    }
-
-    // Map the new memory to the guest address
-    MapMemoryRegion(*impl->current_page_table, guest_addr, size, reinterpret_cast<u64>(new_memory), Common::MemoryPermission::ReadWrite, false);
-
-    // Verify the mapping
-    if (GetPointer(guest_addr) != nullptr) {
-        LOG_INFO(Core_Memory, "Successfully remapped address {:X}", guest_addr);
-        return true;
-    } else {
-        LOG_ERROR(Core_Memory, "Failed to remap address {:X}", guest_addr);
-        std::free(new_memory);
-        return false;
-    }
-}
-
-void Memory::ReclaimUnusedMemory() {
-    std::lock_guard lock(m_tlb_mutex);
-
-    for (auto& entry : m_tlb) {
-        if (entry.valid && entry.ref_count == 0) {
-            // Unmap the memory region
-            UnmapRegion(*impl->current_page_table, entry.guest_addr, entry.size, false);
-
-            // Free the memory
-            std::free(reinterpret_cast<void*>(entry.host_addr));
-
-            // Invalidate the TLB entry
-            entry.valid = false;
-
-            LOG_INFO(Core_Memory, "Reclaimed memory for address {:X}", entry.guest_addr);
-        }
-    }
-}
-
 } // namespace Core::Memory

src/core/memory.h

@@ -492,21 +492,6 @@ public:
 
     bool InvalidateSeparateHeap(void* fault_address);
 
-    /**
-     * Remaps a region of the emulated process address space.
-     *
-     * @param guest_addr The address to begin remapping at.
-     * @param size       The amount of bytes to remap.
-     *
-     * @returns True if remapping is successful, false otherwise.
-     */
-    bool Remap(u64 guest_addr, u32 size);
-
-    /**
-     * Reclaims memory from pages that are no longer used.
-     */
-    void ReclaimUnusedMemory();
-
 private:
     Core::System& system;