Index: lldb/source/Plugins/Process/gdb-remote/CMakeLists.txt
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/CMakeLists.txt
+++ lldb/source/Plugins/Process/gdb-remote/CMakeLists.txt
@@ -26,6 +26,7 @@
   GDBRemoteCommunicationServerLLGS.cpp
   GDBRemoteCommunicationServerPlatform.cpp
   GDBRemoteRegisterContext.cpp
+  GDBRemoteRegisterContext_aarch64.cpp
   GDBRemoteRegisterContext_x86.cpp
   ProcessGDBRemote.cpp
   ProcessGDBRemoteLog.cpp
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.h
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.h
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.h
@@ -42,6 +42,7 @@
   bool UpdateARM64SVERegistersInfos(uint64_t vg);
   void Finalize(const lldb_private::ArchSpec &arch);
 
+  void PreFinalize_aarch64();
   void PreFinalize_x86(const lldb_private::ArchSpec &arch);
   void PostFinalize_x86();
 };
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
@@ -1107,6 +1107,9 @@
     return;
 
   switch (arch.GetMachine()) {
+  case llvm::Triple::aarch64:
+    PreFinalize_aarch64();
+    break;
   case llvm::Triple::x86:
   case llvm::Triple::x86_64:
     PreFinalize_x86(arch);
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext_aarch64.cpp
===================================================================
--- /dev/null
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext_aarch64.cpp
@@ -0,0 +1,49 @@
+//===-- GDBRemoteRegisterContext_aarch64.cpp ------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "GDBRemoteRegisterContext.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::process_gdb_remote;
+
+static uint32_t x31_value_regs[2];
+
+void GDBRemoteDynamicRegisterInfo::PreFinalize_aarch64() {
+  uint32_t max_regnum = 0;
+  uint32_t next_regindex = m_regs.size();
+  for (const RegisterInfo &reg : m_regs)
+    max_regnum = std::max(max_regnum, reg.kinds[eRegisterKindProcessPlugin]);
+
+  ConstString group;
+  group.SetCString("aliases");
+
+  // Alias "sp" into "x31" if necessary.
+  const RegisterInfo *sp_reg = GetRegisterInfo("sp");
+  const RegisterInfo *x31_reg = GetRegisterInfo("x31");
+
+  if (sp_reg && !x31_reg) {
+    x31_value_regs[0] = sp_reg->kinds[eRegisterKindProcessPlugin];
+    x31_value_regs[1] = LLDB_INVALID_REGNUM;
+
+    struct RegisterInfo new_reg {
+      "x31", nullptr, sp_reg->byte_size, LLDB_INVALID_INDEX32, sp_reg->encoding,
+          sp_reg->format,
+          {
+              LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM,
+              ++max_regnum,        next_regindex++,
+          },
+          x31_value_regs, nullptr, nullptr, 0
+    };
+
+    ConstString name;
+    ConstString alt_name;
+    name.SetCString(new_reg.name);
+    AddRegister(new_reg, name, alt_name, group);
+  }
+}
Index: lldb/test/API/functionalities/gdb_remote_client/TestGDBServerTargetXML.py
===================================================================
--- lldb/test/API/functionalities/gdb_remote_client/TestGDBServerTargetXML.py
+++ lldb/test/API/functionalities/gdb_remote_client/TestGDBServerTargetXML.py
@@ -623,6 +623,12 @@
                    ["x0 = 0x0807060504030201"])
         self.match("register read x1",
                    ["x1 = 0x1817161514131211"])
+        self.match("register read x29",
+                   ["x29 = 0x3837363534333231"])
+        self.match("register read x30",
+                   ["x30 = 0x4847464544434241"])
+        self.match("register read x31",
+                   ["x31 = 0x5857565554535251"])
         self.match("register read sp",
                    ["sp = 0x5857565554535251"])
         self.match("register read pc",