diff --git a/lldb/docs/lldb-gdb-remote.txt b/lldb/docs/lldb-gdb-remote.txt
--- a/lldb/docs/lldb-gdb-remote.txt
+++ b/lldb/docs/lldb-gdb-remote.txt
@@ -1661,6 +1661,18 @@
 //                                       start code that may be changing the
 //                                       page table setup, a dynamically set
 //                                       value may be needed.
+//  "low_mem_addressing_bits" unsigned optional, specifies how many bits in 
+//                                       addresses in low memory are significant 
+//                                       for addressing, base 10.  AArch64 can 
+//                                       have different page table setups for low 
+//                                       and high memory, and therefore a different 
+//                                       number of bits used for addressing.
+//  "high_mem_addressing_bits" unsigned optional, specifies how many bits in 
+//                                       addresses in high memory are significant 
+//                                       for addressing, base 10.  AArch64 can have 
+//                                       different page table setups for low and 
+//                                       high memory, and therefore a different 
+//                                       number of bits used for addressing.
 //
 // BEST PRACTICES:
 //  Since register values can be supplied with this packet, it is often useful
diff --git a/lldb/include/lldb/Utility/AddressableBits.h b/lldb/include/lldb/Utility/AddressableBits.h
--- a/lldb/include/lldb/Utility/AddressableBits.h
+++ b/lldb/include/lldb/Utility/AddressableBits.h
@@ -29,8 +29,14 @@
   void SetAddressableBits(uint32_t lowmem_addressing_bits,
                           uint32_t highmem_addressing_bits);
 
+  void SetLowmemAddressableBits(uint32_t lowmem_addressing_bits);
+
+  void SetHighmemAddressableBits(uint32_t highmem_addressing_bits);
+
   void SetProcessMasks(lldb_private::Process &process);
 
+  bool HasValue() const;
+
   void Clear();
 
 private:
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -2124,6 +2124,7 @@
     QueueKind queue_kind = eQueueKindUnknown;
     uint64_t queue_serial_number = 0;
     ExpeditedRegisterMap expedited_register_map;
+    AddressableBits addressable_bits;
     while (stop_packet.GetNameColonValue(key, value)) {
       if (key.compare("metype") == 0) {
         // exception type in big endian hex
@@ -2271,9 +2272,17 @@
       } else if (key.compare("addressing_bits") == 0) {
         uint64_t addressing_bits;
         if (!value.getAsInteger(0, addressing_bits)) {
-          addr_t address_mask = ~((1ULL << addressing_bits) - 1);
-          SetCodeAddressMask(address_mask);
-          SetDataAddressMask(address_mask);
+          addressable_bits.SetAddressableBits(addressing_bits);
+        }
+      } else if (key.compare("low_mem_addressing_bits") == 0) {
+        uint64_t addressing_bits;
+        if (!value.getAsInteger(0, addressing_bits)) {
+          addressable_bits.SetLowmemAddressableBits(addressing_bits);
+        }
+      } else if (key.compare("high_mem_addressing_bits") == 0) {
+        uint64_t addressing_bits;
+        if (!value.getAsInteger(0, addressing_bits)) {
+          addressable_bits.SetHighmemAddressableBits(addressing_bits);
         }
       } else if (key.size() == 2 && ::isxdigit(key[0]) && ::isxdigit(key[1])) {
         uint32_t reg = UINT32_MAX;
@@ -2302,6 +2311,10 @@
       }
     }
 
+    if (addressable_bits.HasValue()) {
+      addressable_bits.SetProcessMasks(*this);
+    }
+
     ThreadSP thread_sp = SetThreadStopInfo(
         tid, expedited_register_map, signo, thread_name, reason, description,
         exc_type, exc_data, thread_dispatch_qaddr, queue_vars_valid,
diff --git a/lldb/source/Utility/AddressableBits.cpp b/lldb/source/Utility/AddressableBits.cpp
--- a/lldb/source/Utility/AddressableBits.cpp
+++ b/lldb/source/Utility/AddressableBits.cpp
@@ -23,8 +23,14 @@
   m_high_memory_addr_bits = highmem_addressing_bits;
 }
 
-void AddressableBits::Clear() {
-  m_low_memory_addr_bits = m_high_memory_addr_bits = 0;
+void AddressableBits::SetLowmemAddressableBits(
+    uint32_t lowmem_addressing_bits) {
+  m_low_memory_addr_bits = lowmem_addressing_bits;
+}
+
+void AddressableBits::SetHighmemAddressableBits(
+    uint32_t highmem_addressing_bits) {
+  m_high_memory_addr_bits = highmem_addressing_bits;
 }
 
 void AddressableBits::SetProcessMasks(Process &process) {
@@ -48,3 +54,11 @@
     process.SetHighmemDataAddressMask(hi_address_mask);
   }
 }
+
+bool AddressableBits::HasValue() const {
+  return m_low_memory_addr_bits != 0 || m_high_memory_addr_bits != 0;
+}
+
+void AddressableBits::Clear() {
+  m_low_memory_addr_bits = m_high_memory_addr_bits = 0;
+}