tests/acceptance: add a new tests to detect counting errors

The insn plugin has a simple heuristic to detect if an instruction is
detected running twice in a row. Check the plugin log after the run
and pass accordingly.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210213130325.14781-22-alex.bennee@linaro.org>

tests/acceptance/tcg_plugins.py

@@ -89,3 +89,29 @@ def test_aarch64_virt_insn(self):
             m = re.search(br"insns: (?P<count>\d+)", s)
             if "count" not in m.groupdict():
                 self.fail("Failed to find instruction count")
+
+    def test_aarch64_virt_insn_icount(self):
+        """
+        :avocado: tags=accel:tcg
+        :avocado: tags=arch:aarch64
+        :avocado: tags=machine:virt
+        :avocado: tags=cpu:cortex-a57
+        """
+        kernel_path = self._grab_aarch64_kernel()
+        kernel_command_line = (self.KERNEL_COMMON_COMMAND_LINE +
+                               'console=ttyAMA0')
+        console_pattern = 'Kernel panic - not syncing: VFS:'
+
+        plugin_log = tempfile.NamedTemporaryFile(mode="r+t", prefix="plugin",
+                                                 suffix=".log")
+
+        self.run_vm(kernel_path, kernel_command_line,
+                    "tests/plugin/libinsn.so", plugin_log.name,
+                    console_pattern,
+                    args=('-cpu', 'cortex-a53', '-icount', 'shift=1'))
+
+        with plugin_log as lf, \
+             mmap.mmap(lf.fileno(), 0, access=mmap.ACCESS_READ) as s:
+            m = re.search(br"detected repeat execution @ (?P<addr>0x[0-9A-Fa-f]+)", s)
+            if m is not None and "addr" in m.groupdict():
+                self.fail("detected repeated instructions")