debug: CeaseMultiTest -> UnavailableMultiTest

Use the new spike mechanism to test OpenOCD behavior when a hart becomes
unavailable while running.

Create CommandException.

Author: timsifive

debug/gdbserver.py

@@ -19,7 +19,7 @@
 from testlib import GdbTest, GdbSingleHartTest, TestFailed
 from testlib import TestNotApplicable, CompileError
 from testlib import UnknownThread
-from testlib import CouldNotReadRegisters
+from testlib import CouldNotReadRegisters, CommandException
 
 MSTATUS_UIE = 0x00000001
 MSTATUS_SIE = 0x00000002
@@ -1807,22 +1807,29 @@ def test(self):
         output = self.gdb.c()
         assertIn("_exit", output)
 
-class CeaseMultiTest(GdbTest):
-    """Test that we work correctly when a hart ceases to respond (e.g. because
+class UnavailableMultiTest(GdbTest):
+    """Test that we work correctly when a hart becomes unavailable (e.g. because
     it's powered down)."""
     compile_args = ("programs/counting_loop.c", "-DDEFINE_MALLOC",
             "-DDEFINE_FREE")
 
     def early_applicable(self):
-        return self.hart.support_cease and len(self.target.harts) > 1
+        return (self.hart.support_cease or
+                self.target.support_unavailable_control) \
+            and len(self.target.harts) > 1
 
     def setup(self):
         ProgramTest.setup(self)
         self.parkOtherHarts()
 
     def test(self):
         # Run all the way to the infinite loop in exit
-        self.gdb.c(wait=False)
+        self.gdb.c_all(wait=False)
+        # Other hart should have become unavailable.
+        if self.target.support_unavailable_control:
+            self.server.wait_until_running(self.target.harts)
+            self.server.command(
+                    f"riscv dmi_write 0x1f 0x{(1<<self.hart.id)&0x3:x}")
         self.gdb.expect(r"\S+ became unavailable.")
         self.gdb.interrupt()
 
@@ -1834,7 +1841,7 @@ def test(self):
                     self.gdb.p("$misa")
                     assert False, \
                         "Shouldn't be able to access unavailable hart."
-                except UnknownThread:
+                except (UnknownThread, CommandException):
                     pass
 
         # Check that the main hart can still be debugged.

debug/testlib.py

@@ -652,6 +652,15 @@ def parse_rhs(text):
         raise TestLibError(f"Unexpected input: {tokens!r}")
     return result
 
+class CommandException(Exception):
+    pass
+
+class CommandSendTimeout(CommandException):
+    pass
+
+class CommandCompleteTimeout(CommandException):
+    pass
+
 class Gdb:
     """A single gdb class which can interact with one or more gdb instances."""
 
@@ -780,8 +789,14 @@ def command(self, command, ops=1, reset_delays=0):
                     reset_delays=None)
         timeout = max(1, ops) * self.timeout
         self.active_child.sendline(command)
-        self.active_child.expect("\n", timeout=timeout)
-        self.active_child.expect(r"\(gdb\)", timeout=timeout)
+        try:
+            self.active_child.expect("\n", timeout=timeout)
+        except pexpect.exceptions.TIMEOUT as exc:
+            raise CommandSendTimeout(command) from exc
+        try:
+            self.active_child.expect(r"\(gdb\)", timeout=timeout)
+        except pexpect.exceptions.TIMEOUT as exc:
+            raise CommandCompleteTimeout(command) from exc
         output = self.active_child.before.decode("utf-8", errors="ignore")
         ansi_escape = re.compile(r'\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])')
         return ansi_escape.sub('', output).strip()