Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.h
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.h
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.h
@@ -145,6 +145,11 @@
   virtual FileSpec FindModuleFile(const std::string &module_path,
                                   const ArchSpec &arch);
 
+  // Process client_features (qSupported) and return an array of server features
+  // to be returned in response.
+  virtual std::vector<std::string>
+  HandleFeatures(const llvm::ArrayRef<llvm::StringRef> client_features);
+
 private:
   ModuleSpec GetModuleInfo(llvm::StringRef module_path, llvm::StringRef triple);
 };
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
@@ -831,26 +831,11 @@
 GDBRemoteCommunication::PacketResult
 GDBRemoteCommunicationServerCommon::Handle_qSupported(
     StringExtractorGDBRemote &packet) {
-  StreamGDBRemote response;
-
-  // Features common to lldb-platform and llgs.
-  uint32_t max_packet_size = 128 * 1024; // 128KBytes is a reasonable max packet
-                                         // size--debugger can always use less
-  response.Printf("PacketSize=%x", max_packet_size);
-
-  response.PutCString(";QStartNoAckMode+");
-  response.PutCString(";QThreadSuffixSupported+");
-  response.PutCString(";QListThreadsInStopReply+");
-  response.PutCString(";qEcho+");
-  response.PutCString(";qXfer:features:read+");
-#if defined(__linux__) || defined(__NetBSD__) || defined(__FreeBSD__)
-  response.PutCString(";QPassSignals+");
-  response.PutCString(";qXfer:auxv:read+");
-  response.PutCString(";qXfer:libraries-svr4:read+");
-#endif
-  response.PutCString(";multiprocess+");
-
-  return SendPacketNoLock(response.GetString());
+  // Parse client-indicated features.
+  llvm::StringRef view = packet.GetStringRef();
+  llvm::SmallVector<llvm::StringRef, 4> client_features;
+  view.split(client_features, ';');
+  return SendPacketNoLock(llvm::join(HandleFeatures(client_features), ";"));
 }
 
 GDBRemoteCommunication::PacketResult
@@ -1312,3 +1297,17 @@
 
   return matched_module_spec;
 }
+
+std::vector<std::string> GDBRemoteCommunicationServerCommon::HandleFeatures(
+    const llvm::ArrayRef<llvm::StringRef> client_features) {
+  // 128KBytes is a reasonable max packet size--debugger can always use less.
+  constexpr uint32_t max_packet_size = 128 * 1024;
+
+  // Features common to platform server and llgs.
+  return {
+      llvm::formatv("PacketSize={0}", max_packet_size),
+      "QStartNoAckMode+",
+      "QThreadSuffixSupported+",
+      "qEcho+",
+  };
+}
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
@@ -219,6 +219,9 @@
 
   static std::string XMLEncodeAttributeValue(llvm::StringRef value);
 
+  virtual std::vector<std::string>
+  HandleFeatures(const llvm::ArrayRef<llvm::StringRef> client_features) override;
+
 private:
   llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>> BuildTargetXml();
 
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -3534,3 +3534,16 @@
 
   return tid;
 }
+
+std::vector<std::string> GDBRemoteCommunicationServerLLGS::HandleFeatures(
+    const llvm::ArrayRef<llvm::StringRef> client_features) {
+  auto ret =
+      GDBRemoteCommunicationServerCommon::HandleFeatures(client_features);
+  ret.insert(ret.end(), {
+    "qXfer:features:read+", "multiprocess+",
+#if defined(__linux__) || defined(__NetBSD__) || defined(__FreeBSD__)
+        "QPassSignals+", "qXfer:auxv:read+", "qXfer:libraries-svr4:read+",
+#endif
+  });
+  return ret;
+}