diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
index 9747461..ea52b02 100644
--- a/gdb/aarch64-linux-nat.c
+++ b/gdb/aarch64-linux-nat.c
@@ -810,6 +810,14 @@ aarch64_linux_watchpoint_addr_within_range (struct target_ops *target,
   return start <= addr && start + length - 1 >= addr;
 }
 
+/* Implement the "to_can_do_single_step" target_ops method.  */
+
+static int
+aarch64_linux_can_do_single_step (struct target_ops *target)
+{
+  return 1;
+}
+
 /* Define AArch64 maintenance commands.  */
 
 static void
@@ -861,6 +869,7 @@ _initialize_aarch64_linux_nat (void)
   t->to_stopped_data_address = aarch64_linux_stopped_data_address;
   t->to_watchpoint_addr_within_range =
     aarch64_linux_watchpoint_addr_within_range;
+  t->to_can_do_single_step = aarch64_linux_can_do_single_step;
 
   /* Override the GNU/Linux inferior startup hook.  */
   super_post_startup_inferior = t->to_post_startup_inferior;
diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index b3ad868..bc2cec4 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -917,6 +917,11 @@ arm_linux_software_single_step (struct frame_info *frame)
   if (arm_deal_with_atomic_sequence (frame))
     return 1;
 
+  /* If the target does have hardware single step, GDB doesn't have
+     to bother software single step.  */
+  if (target_can_do_single_step () == 1)
+    return 0;
+
   next_pc = arm_get_next_pc (frame, get_frame_pc (frame));
 
   /* The Linux kernel offers some user-mode helpers in a high page.  We can
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index cd0abad..58d4119 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -36110,6 +36110,10 @@ This feature indicates whether @value{GDBN} supports vfork event
 extensions to the remote protocol.  @value{GDBN} does not use such
 extensions unless the stub also reports that it supports them by
 including @samp{vfork-events+} in its @samp{qSupported} reply.
+
+@item vContSupported
+This feature indicates whether @value{GDBN} wants to know the
+supported actions in the reply to @samp{vCont?} packet.
 @end table
 
 Stubs should ignore any unknown values for
@@ -36578,6 +36582,10 @@ The remote stub reports the @samp{fork} stop reason for fork events.
 The remote stub reports the @samp{vfork} stop reason for vfork events
 and vforkdone events.
 
+@item vContSupported
+The remote stub reports the supported actions in the reply to
+@samp{vCont?} packet.
+
 @end table
 
 @item qSymbol::
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index 5c0d83d..d614240 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -63,6 +63,11 @@ int non_stop;
 int swbreak_feature;
 int hwbreak_feature;
 
+/* True if the "vContSupported" feature is active.  In that case, GDB
+   wants us to report whether single step is supported in the reply to
+   "vCont?" packet.  */
+static int vCont_supported;
+
 /* Whether we should attempt to disable the operating system's address
    space randomization feature before starting an inferior.  */
 int disable_randomization = 1;
@@ -2111,6 +2116,8 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
 		  if (target_supports_vfork_events ())
 		    report_vfork_events = 1;
 		}
+	      else if (strcmp (p, "vContSupported+") == 0)
+		vCont_supported = 1;
 	      else
 		target_process_qsupported (p);
 
@@ -2217,6 +2224,8 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
       if (the_target->pid_to_exec_file != NULL)
 	strcat (own_buf, ";qXfer:exec-file:read+");
 
+      strcat (own_buf, ";vContSupported+");
+
       /* Reinitialize components as needed for the new connection.  */
       hostio_handle_new_gdb_connection ();
       target_handle_new_gdb_connection ();
@@ -2815,7 +2824,18 @@ handle_v_requests (char *own_buf, int packet_len, int *new_packet_len)
 
       if (startswith (own_buf, "vCont?"))
 	{
-	  strcpy (own_buf, "vCont;c;C;s;S;t");
+	  strcpy (own_buf, "vCont;c;C;t");
+
+	  if (target_supports_hardware_single_step () || !vCont_supported)
+	    {
+	      /* If target supports hardware single step, add actions s
+		 and S to the list of supported actions.  On the other
+		 hand, if GDB doesn't request the supported vCont actions
+		 in qSupported packet, add s and S to the list too.  */
+	      own_buf = own_buf + strlen (own_buf);
+	      strcpy (own_buf, ";s;S");
+	    }
+
 	  if (target_supports_range_stepping ())
 	    {
 	      own_buf = own_buf + strlen (own_buf);
@@ -3555,6 +3575,7 @@ captured_main (int argc, char *argv[])
       cont_thread = null_ptid;
       swbreak_feature = 0;
       hwbreak_feature = 0;
+      vCont_supported = 0;
 
       remote_open (port);
 
diff --git a/gdb/remote.c b/gdb/remote.c
index 3afcaf4..5968af6 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -251,6 +251,12 @@ struct vCont_action_support
 
   /* vCont;r */
   int r;
+
+  /* vCont;s */
+  int s;
+
+  /* vCont;S */
+  int S;
 };
 
 /* Controls whether GDB is willing to use range stepping.  */
@@ -1401,6 +1407,9 @@ enum {
   /* Support for the Qbtrace-conf:pt:size packet.  */
   PACKET_Qbtrace_conf_pt_size,
 
+  /* Support for query supported vCont actions.  */
+  PACKET_vContSupported,
+
   PACKET_MAX
 };
 
@@ -4280,7 +4289,8 @@ static const struct protocol_feature remote_protocol_features[] = {
   { "vfork-events", PACKET_DISABLE, remote_supported_packet,
     PACKET_vfork_event_feature },
   { "Qbtrace-conf:pt:size", PACKET_DISABLE, remote_supported_packet,
-    PACKET_Qbtrace_conf_pt_size }
+    PACKET_Qbtrace_conf_pt_size },
+  { "vContSupported", PACKET_DISABLE, remote_supported_packet, PACKET_vContSupported }
 };
 
 static char *remote_support_xml;
@@ -4370,6 +4380,9 @@ remote_query_supported (void)
 	    q = remote_query_supported_append (q, "vfork-events+");
 	}
 
+      if (packet_set_cmd_state (PACKET_vContSupported) != AUTO_BOOLEAN_FALSE)
+	q = remote_query_supported_append (q, "vContSupported+");
+
       q = reconcat (q, "qSupported:", q, (char *) NULL);
       putpkt (q);
 
@@ -4945,10 +4958,10 @@ remote_vcont_probe (struct remote_state *rs)
   if (startswith (buf, "vCont"))
     {
       char *p = &buf[5];
-      int support_s, support_S, support_c, support_C;
+      int support_c, support_C;
 
-      support_s = 0;
-      support_S = 0;
+      rs->supports_vCont.s = 0;
+      rs->supports_vCont.S = 0;
       support_c = 0;
       support_C = 0;
       rs->supports_vCont.t = 0;
@@ -4957,9 +4970,9 @@ remote_vcont_probe (struct remote_state *rs)
 	{
 	  p++;
 	  if (*p == 's' && (*(p + 1) == ';' || *(p + 1) == 0))
-	    support_s = 1;
+	    rs->supports_vCont.s = 1;
 	  else if (*p == 'S' && (*(p + 1) == ';' || *(p + 1) == 0))
-	    support_S = 1;
+	    rs->supports_vCont.S = 1;
 	  else if (*p == 'c' && (*(p + 1) == ';' || *(p + 1) == 0))
 	    support_c = 1;
 	  else if (*p == 'C' && (*(p + 1) == ';' || *(p + 1) == 0))
@@ -4972,9 +4985,9 @@ remote_vcont_probe (struct remote_state *rs)
 	  p = strchr (p, ';');
 	}
 
-      /* If s, S, c, and C are not all supported, we can't use vCont.  Clearing
-         BUF will make packet_ok disable the packet.  */
-      if (!support_s || !support_S || !support_c || !support_C)
+      /* If c, and C are not all supported, we can't use vCont.  Clearing
+	 BUF will make packet_ok disable the packet.  */
+      if (!support_c || !support_C)
 	buf[0] = 0;
     }
 
@@ -12503,6 +12516,29 @@ remote_pid_to_exec_file (struct target_ops *self, int pid)
   return filename;
 }
 
+/* Implement the to_can_do_single_step target_ops method.  */
+
+static int
+remote_can_do_single_step (struct target_ops *ops)
+{
+  /* We can only tell whether target supports single step or not by
+     supported s and S vCont actions if the stub supports vContSupported
+     feature.  If the stub doesn't support vContSupported feature,
+     we have conservatively to think target doesn't supports single
+     step.  */
+  if (packet_support (PACKET_vContSupported) == PACKET_ENABLE)
+    {
+      struct remote_state *rs = get_remote_state ();
+
+      if (packet_support (PACKET_vCont) == PACKET_SUPPORT_UNKNOWN)
+	remote_vcont_probe (rs);
+
+      return rs->supports_vCont.s && rs->supports_vCont.S;
+    }
+  else
+    return 0;
+}
+
 static void
 init_remote_ops (void)
 {
@@ -12574,6 +12610,7 @@ Specify the serial device it is connected to\n\
   remote_ops.to_can_async_p = remote_can_async_p;
   remote_ops.to_is_async_p = remote_is_async_p;
   remote_ops.to_async = remote_async;
+  remote_ops.to_can_do_single_step = remote_can_do_single_step;
   remote_ops.to_terminal_inferior = remote_terminal_inferior;
   remote_ops.to_terminal_ours = remote_terminal_ours;
   remote_ops.to_supports_non_stop = remote_supports_non_stop;
@@ -13272,6 +13309,9 @@ Show the maximum size of the address (in bits) in a memory packet."), NULL,
   add_packet_config_cmd (&remote_protocol_packets[PACKET_Qbtrace_conf_pt_size],
        "Qbtrace-conf:pt:size", "btrace-conf-pt-size", 0);
 
+  add_packet_config_cmd (&remote_protocol_packets[PACKET_vContSupported],
+			 "vContSupported", "verbose-resume-supported", 0);
+
   /* Assert that we've registered "set remote foo-packet" commands
      for all packet configs.  */
   {
diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
index ddcad94..e134a1c 100644
--- a/gdb/target-delegates.c
+++ b/gdb/target-delegates.c
@@ -832,6 +832,33 @@ debug_masked_watch_num_registers (struct target_ops *self, CORE_ADDR arg1, CORE_
   return result;
 }
 
+static int
+delegate_can_do_single_step (struct target_ops *self)
+{
+  self = self->beneath;
+  return self->to_can_do_single_step (self);
+}
+
+static int
+tdefault_can_do_single_step (struct target_ops *self)
+{
+  return -1;
+}
+
+static int
+debug_can_do_single_step (struct target_ops *self)
+{
+  int result;
+  fprintf_unfiltered (gdb_stdlog, "-> %s->to_can_do_single_step (...)\n", debug_target.to_shortname);
+  result = debug_target.to_can_do_single_step (&debug_target);
+  fprintf_unfiltered (gdb_stdlog, "<- %s->to_can_do_single_step (", debug_target.to_shortname);
+  target_debug_print_struct_target_ops_p (&debug_target);
+  fputs_unfiltered (") = ", gdb_stdlog);
+  target_debug_print_int (result);
+  fputs_unfiltered ("\n", gdb_stdlog);
+  return result;
+}
+
 static void
 delegate_terminal_init (struct target_ops *self)
 {
@@ -4008,6 +4035,8 @@ install_delegators (struct target_ops *ops)
     ops->to_can_accel_watchpoint_condition = delegate_can_accel_watchpoint_condition;
   if (ops->to_masked_watch_num_registers == NULL)
     ops->to_masked_watch_num_registers = delegate_masked_watch_num_registers;
+  if (ops->to_can_do_single_step == NULL)
+    ops->to_can_do_single_step = delegate_can_do_single_step;
   if (ops->to_terminal_init == NULL)
     ops->to_terminal_init = delegate_terminal_init;
   if (ops->to_terminal_inferior == NULL)
@@ -4276,6 +4305,7 @@ install_dummy_methods (struct target_ops *ops)
   ops->to_region_ok_for_hw_watchpoint = default_region_ok_for_hw_watchpoint;
   ops->to_can_accel_watchpoint_condition = tdefault_can_accel_watchpoint_condition;
   ops->to_masked_watch_num_registers = tdefault_masked_watch_num_registers;
+  ops->to_can_do_single_step = tdefault_can_do_single_step;
   ops->to_terminal_init = tdefault_terminal_init;
   ops->to_terminal_inferior = tdefault_terminal_inferior;
   ops->to_terminal_ours_for_output = tdefault_terminal_ours_for_output;
@@ -4427,6 +4457,7 @@ init_debug_target (struct target_ops *ops)
   ops->to_region_ok_for_hw_watchpoint = debug_region_ok_for_hw_watchpoint;
   ops->to_can_accel_watchpoint_condition = debug_can_accel_watchpoint_condition;
   ops->to_masked_watch_num_registers = debug_masked_watch_num_registers;
+  ops->to_can_do_single_step = debug_can_do_single_step;
   ops->to_terminal_init = debug_terminal_init;
   ops->to_terminal_inferior = debug_terminal_inferior;
   ops->to_terminal_ours_for_output = debug_terminal_ours_for_output;
diff --git a/gdb/target.h b/gdb/target.h
index 37e4edb..c38407e 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -566,6 +566,12 @@ struct target_ops
     int (*to_masked_watch_num_registers) (struct target_ops *,
 					  CORE_ADDR, CORE_ADDR)
       TARGET_DEFAULT_RETURN (-1);
+
+    /* Return 1 for sure target can do single step.  Return -1 for
+       unknown.  Return 0 for target can't do.  */
+    int (*to_can_do_single_step) (struct target_ops *)
+      TARGET_DEFAULT_RETURN (-1);
+
     void (*to_terminal_init) (struct target_ops *)
       TARGET_DEFAULT_IGNORE ();
     void (*to_terminal_inferior) (struct target_ops *)
@@ -1903,6 +1909,9 @@ extern char *target_thread_name (struct thread_info *);
 						      addr, len)
 
 
+#define target_can_do_single_step() \
+  (*current_target.to_can_do_single_step) (&current_target)
+
 /* Set/clear a hardware watchpoint starting at ADDR, for LEN bytes.
    TYPE is 0 for write, 1 for read, and 2 for read/write accesses.
    COND is the expression for its condition, or NULL if there's none.
